REVIEW | doi:10.20944/preprints201812.0156.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Marine microorganisms, marine fungi, algae, marine plants, marine invertebrates, marine vertebrates, genome, metagenome
Online: 12 December 2018 (15:44:09 CET)
With the continuing development of sequencing technology, genomics has been applied in a variety of biological research areas. In particular, the application of genomics to marine species, which boast a high diversity, promises great scientific and industrial potential. Significant progress has been made in marine genomics especially over the past few years. Consequently, BGI, leveraging its prominent contributions in genomics research, established BGI-Qingdao, an institute specifically aimed at exploring marine genomics. In order to accelerate marine genomics research and related applications, BGI-Qingdao initiated the International Conference on Genomics of the Ocean (ICG-Ocean) to develop international collaborations and establish a focused and coherent global research plan. Last year, the first ICG-Ocean conference was held in Qingdao, China, during which 47 scientists in marine genomics from all over the world reported on their research progress to an audience of about 300 attendees. This year, we would like to build on that success, drafting a report on marine genomics to draw global attention to marine genomics. We summarized the recent progress, proposed future directions, and we would like to enable additional profound insights on marine genomics. Similar to the annual report on plant and fungal research by Kew Gardens, and the White Paper of ethical issues on experimental animals, we hope our first report on marine genomics can provide some useful insights for researchers, funding agencies as well as industry, and that future versions will expand upon the foundation established here in both breadth and depth of knowledge.This report summarizes the recent progress in marine genomics in six parts including: marine microorganisms, marine fungi, marine algae and plants, marine invertebrates, marine vertebrates and genomics-based applications.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Kinase Inhibitor; NEK2; Chemoresistance; Avicennia marina; Marine compounds; Molecular docking; Cancer
Online: 7 June 2020 (11:16:35 CEST)
Never in mitosis gene A-related kinase 2 (NEK2) a member of serine-threonine kinase protein mainly involved in the cell cycle process. Clinical studies revealed NEK2 overexpression in various tumour types, also NEK2 was reported for their association with genetic abnormalities like mitotic machinery deregulation and chromosomal instability. Besides NEK2 plays a key role in maintaining the transformed phenotype of cancer cells and chemo-resistance of several tumour types. Thus, NEK2 transcriptional profile is important for diagnosis, treatment, and prognosis stages of cancer studies. Screening of novel NEK2 inhibitor would be beneficial in developing the specific lead molecules. Our studies involved NEK2 transcriptional profile search, screening of druggable cavities in NEK2, Drug likeliness of mangrove derived naphthoquinone derivatives avicennoneA , avicennoneB , avicennoneC , avicennoneD , avicenoneE , avicennone F , and avicennone G , avicequinone A, stenocarpoquinone B , avicequinone C , avicenol A , avicenol C,brugine, apigenin, chrysin and molecular docking studies to assess MNC compounds binding efficacy towards NEK2. Mangrove derived compounds conferred the intermolecular hydrogen bond, Pi-alkyl,pi-cation interactions with NEK2 kinase domain region residues Tyr 19, Lys 37, Arg 164, Lys174. Nearly 200 kinase proteins contained this promising Cys 22 residue as its positioned in the catalytic site like NEK family proteins. Avicenna A, Avicennone G, Chrysin and Brugine formed the irreversible covalent binding with NEK2 through Cys 22, thus they can be considered as potential kinase inhibitors with the limited off-target response. But these MNC compounds need to be tested further in invitro and invivo studies to propose as potent NEK2 inhibitors.
ARTICLE | doi:10.20944/preprints202003.0372.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: COVID-19; SARS-CoV-2; Marine natural product; Virtual screening; Docking
Online: 25 March 2020 (08:23:57 CET)
The current emergency due to the worldwide spread of the COVID-19 caused by the new SARS-CoV-2 is a great concern for global public health. Already in the past, the outbreak of severe acute respiratory syndrome (SARS) in 2003 and Middle Eastern respiratory syndrome (MERS) in 2012 demonstrates the potential of coronaviruses to cross-species borders and further underlines the importance of identifying new-targeted drugs. An ideal antiviral agent should target essential proteins involved in the lifecycle of SARS-CoV. Currently, some HIV protease inhibitors (i.e., Lopinavir) are proposed for the treatment of COVID-19, although their effectiveness was not yet assessed. The main protease (Mpro) provides a highly validated pharmacological target for the discovery and design of inhibitors. We identified potent Mpro inhibitors employing computational techniques that entail the screening of a Marine Natural Product (MNP) library. MNP library was screened by hyphenated pharmacophore model, and molecular docking approaches. Molecular dynamics and re-docking further confirmed the results obtained by structure-based techniques and allowed to highlight some crucial aspects. Seventeen potential SARS-CoV-2 Mpro inhibitors have been identified among the natural substances of marine origin. As these compounds were extensively validated by a consensus approach and by molecular dynamics, the likelihood that at least one of these compounds could be bioactive is excellent.
REVIEW | doi:10.20944/preprints201906.0029.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: antitumour compounds; marine natural products; bioactivity; cytotoxicity; marine invertebrates
Online: 4 June 2019 (12:55:33 CEST)
Recent advances in sampling and novel techniques in drug synthesis and isolation have promoted the discovery of anticancer agents from marine organisms to combat this major threat to public health worldwide. Bryozoans, filter-feeding, sessile aquatic invertebrates often characterized by a calcified skeleton, are an excellent source of pharmacologically interesting compounds including well-known chemical classes such as alkaloids and polyketides. This review covers the literature for secondary metabolites isolated from marine cheilostome and ctenostome bryozoans that have shown potential as cancer drugs. Moreover, we highlight examples such as bryostatins, the most known class of marine-derived compounds from this animal phylum, which is advancing through anticancer clinical trials due to their low toxicity and antineoplastic activity. The bryozoan antitumour compounds discovered until now show a wide range of chemical diversity and biological activities. Therefore, more research focusing on the isolation of secondary metabolites with potential anticancer properties from bryozoans and other overlooked taxa covering wider geographic areas is needed for an efficient bioprospecting of natural products.
REVIEW | doi:10.20944/preprints201905.0066.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: chitin; chitosan; cosmetics; biodegradability; biomaterials; polysaccharides; green technology; marine cosmetic ingredients; marine green source; marine resources
Online: 6 May 2019 (12:37:44 CEST)
Huge amounts of chitin and chitosans can be found in the biosphere as important constituent of the exoskeleton of many organisms, as well as waste by worldwide seafood companies. Nowadays, politicians, environmentalists, and industrialists encouraged the use of these marine polysaccharides as renewable source, particularly when developed by alternative eco-friendly processes, especially in the production of regular cosmetics. The aim of this review is to outline the physicochemical and biological properties and the different bioextraction methods of chitin and chitosans sources, focusing on enzymatic deproteinization, bacteria fermentation, and enzymatic deacetylation methods. Thanks to their biodegradability, non-toxicity, biocompatibility, and bioactivity, the application of these marine polymers is widely used in the contemporary manufacturing of biomedical and pharmaceutical products. In the end, advanced cosmetic products based on chitin and chitosans are presented, analyzing different therapeutic aspects about skin, hair, nail, and oral care. The innovative formulations described can be considered as excellent solutions regarding problems in the various body anatomical sectors.
CONCEPT PAPER | doi:10.20944/preprints202110.0017.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Bioenergy; marine fermentation; seawater; marine yeast; microalgae; seaweed; circular economy; high value chemicals
Online: 1 October 2021 (12:19:47 CEST)
Biofuels have many environmental and practical benefits as a transportation fuel. They are among the best alternatives to fossil fuels due to their capacity for negative carbon emissions, which is vital for archiving the global ambition of a Net-Zero Economy. However, conventional biofuel production takes place on inland sites and relies on freshwater and edible crops (or land suitable for edible crop production), which has led to the food vs fuel debate. It also suffers technical and economical barriers due to the energy balance and the cost of production compared to fossil fuels. Establishing a coastal integrated marine biorefinery (CIMB) system for the simultaneous production of biofuels, high-value chemicals, and other co-products could be the ultimate solution. The proposed system is based on coastal sites and relies on marine resources including seawater, marine biomass (seaweed) and marine microorganisms (marine yeasts and marine microalgae). The system will not require the use of arable land and freshwater in any part of the production chain and will be linked to offshore renewable energy sources to increase its economic and environmental value. This article aims to introduce the CIMB system as a potential vehicle for addressing global warming and speeding the global effort on climate change mitigation as well as increasing global water, food and energy security. I hope this perspective may serve to draw attention into research funding for this approach.
ARTICLE | doi:10.20944/preprints201703.0087.v1
Subject: Biology And Life Sciences, Virology Keywords: Zika Virus, Antiviral, Marine Algae
Online: 14 March 2017 (18:34:37 CET)
For many years marine algae has been subject of numerous researches and as a source of natural products with antiviral activity, such as terpenes, alkaloids and sulphated polysaccharides. However, the anti-Zika virus (ZIKV) potential of algae has not been studied. In this study we evaluated extracts seven species of the three major classes of seaweeds (Phaeophyceae, Chlorophyceae and Rhodophyceae) against ZIKV. All seaweeds tested are native of the Brazilian coast, except for Kappaphycus alvarezii that can be cultivated. ZIKV a mosquito-borne flavivirus, has become a public health problem. In recent years there has been an increase in the number of cases and a strong association between ZIKV outbreak and the spread of cases of Guillain-Barré Syndrome and microcephaly. All seaweed extracts tested in this work inhibits ZIKV replication in a dose-dependent manner. Caulerpa racemosa, Kappaphycus alvarezii and Osmundaria obtusiloba extracts were able to inhibit viral replication at low concentrations with EC50 values ranging from 1.38 to 1.98 µg/mL. We observed that O. obtusiloba presented a significant virucidal effect. Our results suggest that extracts of C. racemosa, K. alvarezii and O. obtusiloba presented very promising results, being excellent candidates for further studies, demonstrating that marine algae are an interesting source for the development of novel anti-ZIKV agents.
ARTICLE | doi:10.20944/preprints202108.0020.v2
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Bioethanol; LCA; marine fermentation; seawater; Saccharomyces cerevisiae; water footprint; bioenergy; biofuel; marine yeast; GHG
Online: 9 August 2021 (14:52:46 CEST)
Bioethanol has many environmental and practical benefits as a transportation fuel. It is one of the best alternatives to replace fossil fuels due to its liquid nature which is similar to petrol and diesel fuels traditionally used in transportation. In addition, bioethanol production technology has the capacity for negative carbon emissions which is vital for solving the current global warming dilemma. However, conventional bioethanol production takes place based on an inland site and relies on freshwater and edible crops (or land suitable for edible crop production) for production, which has led to the food vs fuel debate. Establishing a coastal marine biorefinery (CMB) system for bioethanol production that is based on coastal sites and relies on marine resources (seawater, marine biomass and marine yeast) could be the ultimate solution. In this paper, we aim to evaluate the environmental impact of using seawater for bioethanol production at coastal locations as a step towards the evaluation of a CMB system. Hence, a life cycle assessment for bioethanol production was conducted using the proposed scenario named Coastal-Seawater and compared to the conventional scenario, named Inland-Freshwater (IF). The impact of each scenario in relation to climate change, water depletion, land use and fossil depletion was studied for comparison. The coastal-seawater scenario demonstrated an improvement upon the conventional scenario in all the selected impact categories. In particular, the use of seawater in the process had a significant effect on water depletion showing an impact reduction of 31.2%. Furthermore, reductions are demonstrated in natural land transformation, climate change and fossil depletion of 5.5%, 3.5% and 4.2% respectively. This indicates the positive impact of using seawater and coastal locations for bioethanol production and encourages research to investigate the CMB system.
ARTICLE | doi:10.20944/preprints201702.0102.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Marine Energy; Tidal turbine; horizontal-axis marine current turbine; OCT; Turbulence; Support Structure; device wake
Online: 28 February 2017 (11:55:00 CET)
Tidal stream energy is a low carbon energy source. Tidal stream turbines operate in a turbulent environment, and the effect of the structure between the turbine and seabed on this environment is not fully understood. An experimental study using 1:72 scale models based on a commercial turbine design was carried out to study the support structure influence on turbulence intensity around turbine blades. The study was conducted using the wave-current tank at LABIMA, University of Florence. A realistic flow environment (ambient turbulent intensity = 11%) was established. Turbulence intensity was measured upstream and downstream of a turbine mounted on two different support structures (one resembling a commercial design, the other the same with an additional vertical element), in order to quantify any variation in turbulence and performance between the support structures. Turbine drive power was used to calculate power generation. Acoustic Doppler Velocimetry was used to record and calculate upstream and downstream turbulence intensity. In otherwise identical conditions, performance variation of only 4% was observed between two support structures. Turbulent intensity at 1, 3 and 5 blade diameters, both upstream and downstream, showed variation up to 21% between the two cases. The additional turbulent structures generated by the additional element of the second support structure appears to cause this effect, and the upstream propagation of turbulent intensity is believed to be permitted by surface waves. This result is significant for the prediction of turbine array performance.
REVIEW | doi:10.20944/preprints201812.0352.v1
Subject: Biology And Life Sciences, Other Keywords: marine biotoxins; contaminated seafood; public health
Online: 29 December 2018 (02:31:01 CET)
Harmful algal blooms (HABs) are natural events produced by massive concentration of toxic phytoplankton that can color red, ocher, brown or yellow large extensions of water, its intensity depends on the different species of phytoplankton involved in the proliferation. The spreading of these formations involves an interaction of biological, chemical, meteorological and anthropogenic factors. Several species with potential toxicity have been reported along Mexican coasts, such as Gymnodinium catenatum, Karenia brevis, Pyrodinium bahamense var. compressum. The toxic bloom not only causes an impact during the event, it produces negative effects afterward, such as accumulating deposits of organic matter, alterations of benthic community structure and composition, species presence/absence, and bioaccumulation of toxins in organisms such as bivalve molluscs mainly. Poisoning may occur by consuming contaminated seafood or by direct exposure to aerosols of the toxins, which can provoke diarrhea or even death. Due to the impact of this type of event on the economy, environment and public health, strategies for monitoring, prevention, and systematic mitigation have been implemented for the evaluation of HAB effects. The aim of this review was to determine the state-of-the art of HAB, their reports and effects on the environment and public health in Mexico.
REVIEW | doi:10.20944/preprints202110.0354.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Phorbas; marine sponges; marine natural products (MNPs); bioactivity,; cytotoxic metabolites; antimicrobial and anti-inflammatory activities; sesterterpene
Online: 25 October 2021 (13:16:55 CEST)
Porifera, commonly referred to as marine sponges, have stood out as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention along years. They are widespread in all continents, and several structurally unique compounds have been identified from species of this genus. Terpenes, mainly sesterterpenoids, represent the great majority of secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have shown a variety of biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial and anti-inflammatory activities, have been isolated and structurally characterized. This work brings an overview of Phorbas secondary metabolites reported since the first study published in 1993 until 2020, and their biological activities.
ARTICLE | doi:10.20944/preprints202211.0293.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: marine intrusion; induced polarisation; polarizability; decay time
Online: 16 November 2022 (02:34:59 CET)
This study presents the developments regarding the time-domain-induced polarisation method, as a supporting tool for resistivity soundings during investigations of coastal detrital aquifers that are salinised by marine intrusion. The interpretation of resistivity measurements in such aquifers, which have variable hydrochemistry and lithology, involves uncertainties owing to the presence of low-resistivity lithologies, such as clays. To reduce these uncertainties, the use of other geophysical parameters is necessary; hence, this study focuses on induced polarisation, since it can be measured simultaneously with resistivity. In detail, we propose the determination of induced polarisation using 1D techniques, while developing a different algorithm for processing the induced polarisation data. The aim is to extend the results of this phenomenon, using instead of chargeability, the concepts of polarisability and decay time, which are extracted from the decay curve, given that they represent more intrinsic properties of the various analysed subsurface media. We present results obtained by applying this methodology to a Quaternary aquifer of the Costa del Sol in the SE Iberian Peninsula (in the province of Almería) during two different campaigns, one before and one after winter (i.e., in October and February, respectively). The results reveal the position of the saline front during each campaign, while reflecting the seasonal movement of the marine intrusion.
ARTICLE | doi:10.20944/preprints202111.0541.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Codium fragile; marine algae; anti-obesity; prebiotics
Online: 29 November 2021 (14:51:07 CET)
Polysaccharides from marine algae exhibit beneficial biological activities. In this study, we examined the effect of polysaccharides from Codium fragile (PCF) on prebiotic and anti-obesity activity. PCF increases the growth of specific beneficial microbial populations with concomitant decrease in pathogenic microbes. Further, total phenolic content (TPC), total flavonoid content (TFC), and DPPH radical scavenging activity (DPPH activity) after fermentation with PCF as carbon source were higher than for the glucose as control. Moreover, PCF inhibited adipocyte differentiation by inducing differentiation-related factors when the induction of 3T3-L1 preadipocytes into adipocytes was induced. Therefore, we suggest that PCF can be used as prebiotic material with anti-obesity for human health.
ARTICLE | doi:10.20944/preprints202110.0140.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: performance; biodegradation; bacterial consortium; marine sponge; PAHs
Online: 8 October 2021 (12:09:30 CEST)
Every petroleum processing industry produces sewage sludge containing several types of poly-cyclic aromatic hydrocarbon (PAHs) components. The degradation of PAH components by physical, biological and chemical methods is not efficient. The use of marine sponge symbiont bacteria is considered an alternative method in the degradation and reduction of PAHs com-pared to the previous method. This study aims to explore the potential and performance of a consortium of sponge symbiont bacteria in degrading anthracene and pyrene. There are three types of bacteria (Bacillus pumilus strain GLB197, Pseudomonas stutzeri strain SLG510A3-8, Acineto-bacter calcoaceticus strain SLCDA 976) were mixed to form a consortium. The interaction between the bacterial consortium suspension and PAH components was measured at 5-day intervals for 25 days. The biodegradation performance of bacteria on PAHs samples was determined based on five biodegradation parameters. The analysis results showed a decrease in the concentration of anthracene (21.89%) and pyrene (7.71%), equivalent to a ratio of 3: 1. The data was followed by a decrease in the abundance of anthracene (60.30%) and pyrene (27.52%), an equivalent ratio of 2: 1. The level of degradation of the pyrene component is lower than that of the anthracene compo-nent, presumably due to the higher toxicity of pyrene and the more stable molecular structure, making it difficult for bacterial cells to destroy it. The biodegradation products are organic compounds of alcohol, aldehyde, carboxylic acids and a small proportion of aromatic hydrocarbon components. Keywords: performance; biodegradation; bacterial consortium; marine sponge; PAHs
REVIEW | doi:10.20944/preprints201810.0562.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: gelatine; marine; by-products; fish; industry; extraction
Online: 24 October 2018 (09:37:38 CEST)
In recent years, demand for consumption of marine foods, and especially fish, has substantially increased worldwide. The majority of collagen available is sourced from mammalian-derived products. Although fish derived gelatine is a viable alternative to mammalian sourced gelatine, there are some challenges related to the use of fish gelatine including odour, colour, gelling and film forming properties as well as consistency in gelatine amino acid composition. Chemicals used for pre-treatment, as well as extraction conditions such as temperature and time, can influence the length of polypeptide chains that result and the functional properties of the gelatine. Compared to mammalian sources, gelatines derived from fish show notable differences in physical and chemical properties, and great care should be paid to optimization of the production process in order to obtain a product with the best properties for intended applications. The focus of this review is to explore the feasibility of producing gelatine sourced from marine processing by-products using different pre-treatment and extraction strategies with the aim of improving the techno-functional properties of the final product and improving the clean-label status of gelatines. The bioactivities of gelatine hydrolysates are also discussed.
REVIEW | doi:10.20944/preprints201810.0174.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: gelatine; marine; by-products; fish; industry; extraction
Online: 9 October 2018 (05:54:23 CEST)
In recent years, demand for consumption of marine foods, and especially fish, has substantially increased worldwide. The majority of collagen available is sourced from mammalian-derived products. Although fish derived gelatine is a viable alternative to mammalian sourced gelatine, there are some challenges related to the use of fish gelatine including odour, colour, gelling and film forming properties as well as consistency in gelatine amino acid composition. Chemicals used for pre-treatment, as well as extraction conditions such as temperature and time, can influence the length of polypeptide chains that result and the functional properties of the gelatine. Compared to mammalian sources, gelatines derived from fish show notable differences in physical and chemical properties, and great care should be paid to optimization of the production process in order to obtain a product with the best properties for intended applications. The focus of this review is to explore the feasibility of producing gelatine sourced from marine processing by-products using different pre-treatment and extraction strategies with the aim of improving the techno-functional properties of the final product and improving the clean-label status of gelatines. The bioactivities of gelatine hydrolysates are also discussed.
ARTICLE | doi:10.20944/preprints202207.0336.v1
Subject: Business, Economics And Management, Economics Keywords: Environmental Accounting; Life Cycle Assessment; Marine Ecosystem Service; Indicators; Cost Benefit Analysis; Porto Cesareo Marine Protected Area; CICES
Online: 22 July 2022 (11:43:53 CEST)
The article focuses on the integrated environmental accounting model called 'eValue', developed for protected areas and applied in the research programme coordinated by the Italian Ministry of the Environment and aimed at implementing an environmental accounting system for Italian Marine Protected Areas (MPAs). eValue adopts a cost-benefit analysis approach. Financial accounting based on costs and revenues is integrated with environmental accounting, which reflects environmental costs and environmental revenues, i.e. environmental benefits. The environ-mental costs assess the impacts related to human activities in the MPA expressed by calculating the carbon footprint and the environmental benefits of the marine ecosystem services calculated by applying monetary valuation techniques. The values thus estimated flow into the annual flow account, where the value produced (or consumed) by the MPA is estimated by difference. The eValue model was applied to the Porto Cesareo MPA (Italy). eValue showed that the annual benefit-cost ratio reaches a value of 3.4. Furthermore, the ratio of net benefit to public funding is 3.7, completely covering the amount of public transfers and thus summarizing the MPA overall value for money.
ARTICLE | doi:10.20944/preprints202305.1212.v1
Subject: Engineering, Marine Engineering Keywords: marine survey; acoustic reflection; spectral analysis; sediments identification
Online: 17 May 2023 (08:43:40 CEST)
The paper deals with applying Artificial Intelligence techniques to examine CHIRP-recorded data in sand and sandstone sea-bottom sites. The provided analysis of the state of the art portrays that actual time series or spectrum backscattered data from a point on the sea bottom were rarely used as the features for machine learning models. The results of the examination indicate that types of sea bottom can be quantitatively characterized by applying logistic regression models to either the backscatter time series of a frequency-modulated signal or the spectrum of that backscatter. The examination accuracy reached 90% for the time series and 94% for the spectra. The application of spectral data as features for more advanced machine learning algorithms, and the advantages of its combination with other types of data have great potential for future research and the enhancement of remote marine soil classification.
ARTICLE | doi:10.20944/preprints202303.0290.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Mucilage microbiome; Shotgun-metagenome sequencing; Comparative marine microbiome
Online: 15 March 2023 (15:24:58 CET)
The intense emergence of mucilage in the Marmara Sea in 2021 has raised concerns due to its potential impact on the global marine system. Considering the potential of mucilage threatening the diverse ecosystems, it is important to define the mucilage microbiome. However, studies dedicated to exploring the biodiversity of mucilage are limited and de novo approaches are needed to understand unexplored biodiversity of mucilage microenvironment. This study aimed to investigate mucilage and water samples from certain stations in Marmara Sea. For this reason, 11 mucilage, 2 pre-mucilage water and 3 clean sea water were collected from 16 stations. DNA isolation, shotgun metagenome sequencing and bioinformatics analysis were performed. It was revealed that the mucilage microbiome and the clean water microbiome were different from each other, and the reads that could not be assigned to any taxon (dark matter) accounted for 58% (p=0.014) of the mucilage metagenome. The clean water had a higher presence of Euryarchaeota (p=0.014), Proteobacteria (p=0.019) and Rhodothermaeota (p=0.034), while Chlamydiae (p=0.014) and Fusobacteria (p=0.034) were found in excess in the mucilage. The study produced the first comparative data on clean sea water and the mucilage microbiome using shotgun metagenomics approaches.
REVIEW | doi:10.20944/preprints202209.0048.v1
Subject: Chemistry And Materials Science, Chemical Engineering Keywords: removal; PAHs; heavy metals; marine sponges; bacterial consortium
Online: 5 September 2022 (07:43:34 CEST)
Toxic materials in waste generally contain several components of global trending pollutant categories, especially PAHs and heavy metals. Bioremediation technology for managing waste utilizing microorganisms (bacteria) has not been fully capable of breaking down these toxic materials simple and environmentally friendly chemical products. This study examines the potential application of a marine sponge symbiont consortium with high performance and efficiency in removing PAHs and heavy metal contaminants. The method is carried out through a review of some related research articles by the author and published by other re-searchers. The study results concluded that bioremediation technology development GTP, can be carried out to improve remediation efficiency. Several types of marine sponge symbiont bacteria, hydrocarbonoclastic (R-1), metalloclastic (R-2), and metallohydro-carbonoclastic (R-3), have the potential to be applied to improve the removal performance of waste. Bacterial screening be done to find and categorize R-1 bacteria, R-2; R-3 to remediate GTP. Develop of R-1 bacteria, R-2; R-3 forms of the mobile formulation are needed in the future. A crystalline consortium of bacteria preparations is needed so that they can be quickly mobilized to locations exposed to GTP. Marine sponge symbiont bacteria be traced mainly to marine sponges whose body surface is covered with mucus.
ARTICLE | doi:10.20944/preprints202202.0129.v2
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: biodegradation; pyrene; pollutants; bacteria; marine sponges; polluted seawater
Online: 22 April 2022 (03:32:48 CEST)
PAHs contaminants have toxic, carcinogenic, and even mutagenic properties. Screening bacteria from different sources capable of carrying out the biodegradation of PAHs is important for mapping and mobilization purposes and applying them to polluted hydrocarbon environments. The study aimed to compare the biodegradation power of two types of bacteria isolated from different sources against PAHs. The method applied is the interaction between bacterial suspen-sion and pyrene contaminated waste for 30 days. Biodegradation products in organic compounds were analyzed using GC/MS and FTIR. The analysis results found several indications of the performance of bacterial biodegradation, namely: the aggressiveness of biodegradation of Bl bacteria against pyrene was relatively more dominant than Sb bacteria. The percentage of to-tal bacterial biodegradation for product type Sb was (39.00 %), and that of the product of bacteri-al degradation type Bl (was 38.29 %). The biodegradation products of the test bacteria (Bl and Sb) were relatively similar to pyrene, in the form of alcohol and carboxylic acid organic com-pounds. It was concluded that there was no significant difference in biodegradation per-formance between Bl and Sb bacteria on for pyrene. Both types of bacterial isolates from differ-ent sources can carry out the function of biodegradation of pyrene.
REVIEW | doi:10.20944/preprints202103.0771.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: cancer; gold nanoparticles; marine; drug delivery; imaging; detection
Online: 31 March 2021 (14:44:42 CEST)
Cancer is one of the health concerns in modern societies. The application of nanotechnology in medical sciences has created new possibilities for the diagnosis, imaging and the treatment of tumors in humans. The present article reviews the application of marine-based gold nanoparticles in diagnosing and treating cancer. The main data were collected from research article on the application of different marine-based gold nanoparticles in detecting and imaging cancer cells as well as in drug delivery system in treatment of cancer. Chitosan is the most used marine natural compound used to fabricate gold nanocomposites and the most reported application of this type of nano-composites is related to drug delivery system. Despite the excellent anticancer potential of different marine natural products, less studies have been conducted on the use of their compositions with gold nanoparticles in cancer therapy than other materials. Moreover, most reports available in this filed are related to their application as a drug delivery system not anticancer drug. In general, there are still challenges and limitations to the use of nanoparticles in medicine, it is hoped that in the near future nanoparticles will create a dramatic revolution not only in oncology but also in medicine.
REVIEW | doi:10.20944/preprints202009.0198.v2
Subject: Biology And Life Sciences, Virology Keywords: coronavirus; aquatic organisms; fish; marine mammals; frogs; birds
Online: 22 September 2020 (11:45:01 CEST)
Coronaviruses are pathogens recognized for having an animal origin, commonly associated with terrestrial environments. However, although in a few cases, there are reports of their presence in aquatic organisms like fish, frogs, waterfowls and marine mammals. None of these cases has led to human health effects when contact with these infected organisms has taken place, whether they are alive or dead. Aquatic birds seem to be the main group carrying and circulating these types of viruses among healthy bird populations. Although the route of infection for CoVID-19 by water or aquatic organisms has not yet been observed in the wild, the relevance of its study is highlighted because there are cases of other viral infections known to have been transferred to humans by aquatic biota. It is encouraging to know that aquatic species, such as fish, marine mammals, and amphibians, shows very few cases of coronaviruses and that some other aquatic animals may also be a possible source of cure or treatment against then, as some evidence with algae and marine sponges suggest.
ARTICLE | doi:10.20944/preprints201909.0221.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: dredged marine sediment; heavy metal; immobilization; kaolinite; limestone
Online: 19 September 2019 (11:24:05 CEST)
The remediation of dredged marine sediments contaminated by heavy metals has drawn increasing attention worldly. The immobilization was regarded as a promising method to reduce adverse impacts on marine ecosystem. In this study, kaolinite and limestone were used as amendments to immobilize heavy metals (e.g. Zn, Pb and Cu) respectively in dredged marine sediments collected from the coastal zone adjacent to Tianjin Port in Bohai Bay. The sequential extraction procedure was applied to identify the mobility of heavy metals and further to evaluate the immobilization effect of amendments. The physical-chemical properties of sediments, such as pH, electrical conductivity (EC), salinity, and total organic carbon (TOC), were also measured to better understand their influence on heavy metals’ mobility. In addition, the compositions of clay minerals were also analyzed to identify the transformation process of minerals in the sediments. The results of sequential extraction procedure indicated that mobile fractions of heavy metals were converted into relatively stable fractions because of the two amendments. In addition, EC, salinity and TOC decreased moderately while no obvious variations of pH in the sediments were observed with the addition of the the kaolinite and the limestone. The percentage of montmorillonite decreased to minimum value while that of chlorite increased gradually during the experimental periods for 40 days probably due to complexation reaction. It was confirmed that both kaolinite and limestone can effectively reduce the mobility and bioavailability of heavy metals, particularly for Zn, generally, limestone has a better immobilization effect compared with kaolinite.
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: marine nematodes; mtCOI; DNA taxonomy; meiofauna; Mexican Caribbean
Online: 4 July 2019 (09:51:50 CEST)
Nematode biodiversity is mostly unknown; while about 20,000 nematode species have been described, estimates for species diversity range from 0.1 to 100 million. The study of nematode diversity, like that of meiofaunal organisms in general, has been mostly based on morphology-based taxonomy, a time-consuming and costly task that requires well-trained specialists. This work represents the first on the taxonomy of Mexican nematodes to integrate morphological and molecular data. We add seven new morphological records for the Mexican Caribbean: Anticomid sp1, Cylicolaimus sp1, Oncholaimus sp2, Platycoma sp1, Catanema sp1, Enopliodes spp., and Metachromadora spp. We recover 55 COI sequences that represent 20 species. Of the studied sites, Cozumel had 12 species and Cancún had two species (Rhips sp1 and Monoposthia mirabilis) represented by several individuals. All sequences are new for the genetic international databases GenBank and BOLD. Phylogenetic analyses and species delineation methods support the occurrence of the 20 entities and confirm the high resolution of COI sequences in delimiting species. ABGD and mPTP methods disentangled 20 entities, whereas Barcode Index Numbers (BINs) recovered 22 genetic species. DNA taxonomy was demonstrated to be an efficient, fast, and low-cost method to address a taxonomical shortfall of meiofaunal organisms.
ARTICLE | doi:10.20944/preprints201811.0346.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: marine ecotourism; coastal areas; fishermen; development models; sustainable
Online: 15 November 2018 (05:51:15 CET)
Coastal areas in the South Coast of West Java Province have the potential to develop marine ecotourism, one of which is the Pangandaran area which must be transferred into economic value by not damaging natural resources. Marine ecotourism development is not only intended to raise foreign exchange for local governments, but are also expected to play a role in maintaining natural resources sustainably. This research aims to analyze the sustainable synergistic marine ecotourism development model. The method used in this research using quantitative descriptive method. The Quantitative descriptive method is used to describe the general condition of the research area, using primary and secondary data. The technique of taking respondents using accidental sampling as many as 50 respondents consisting of tourists, public figures, fishermen who have side jobs as a provider of marine ecotourism services. The analysis tool used is through a Rapfish model approach to measuring the synergistic model of sustainable development of marine ecotourism. Based on the results of a research on a sustainable synergistic marine ecotourism development model by measuring the ecological dimensions of environmental services in high conditions, the economic dimension of marine ecotourism is in moderate condition. Marine ecotourism technology in low conditions and social dimensions of marine ecotourism in low conditions. Model development of sustainable marine ecotourism synergistic with regard to the dimension of environmental, economic and social institutions should be able to form integrated from infrastructure to support marine ecotourism up to raise the level of income of fishermen who have a second job as a marine ecotourism providers. The infrastructure and regulatory dimensions are recommended to use the technology information to promote marine ecotourism optimally and regulations need to make marine ecotourism zoning rules and infrastructure improvements.
REVIEW | doi:10.20944/preprints201810.0772.v1
Subject: Medicine And Pharmacology, Dermatology Keywords: Marine algae; Carbohydrates; Oligosaccharides; Monosaccharides; Skin health; Cosmeceuticals
Online: 1 November 2018 (18:19:37 CET)
Marine algae have been considered as abundant source of bioactive compounds with cosmeceutical potential. Recently, a great deal of interest has focused on the health-promoting effects of marine bioactive compounds. Carbohydrate is a major and abundant constitute of marine algae that have been utilized in cosmetic formulations, such as moisturizing and thickening agents. In addition, marine carbohydrates have been suggested as promising bioactive biomaterials for various skin beneficial properties, such as anti-oxidant, anti-melanogenic and anti-skin aging. Therefore, marine algae carbohydrates have potential of skin health benefits for value-added cosmeceutical application. The present review focused on the various biological capacities and potential skin health benefits of bioactive marine carbohydrates.
ARTICLE | doi:10.20944/preprints201809.0546.v1
Subject: Engineering, Marine Engineering Keywords: wave energy, marine loads, RAO function, dynamic response
Online: 27 September 2018 (13:11:46 CEST)
This paper presents performed Ansys numerical simulation on WindFloat structures. It contributes to the methodology of calculation based on CFD instruments to study the movements of the waves on semi-submersible stationary structures and highlights the importance of using RAO functions. RAO numerical approach developed can be applied to design semisubmersible WindFloat structures in order to fulfill essential requirements regarding operational safety and design. Numerical methodology was designed in accordance marine loads and the I.T.T.C. recommendations. The numerical RAO results for regular wave movements include many elements for the semi-submergible structure. Close results to open sea operation can be achieved by constant improvement in numerical simulation methodologies. The work opens the way for further hydrodynamic development on irregular waves for realistic hydrodynamic and structural response of the actual semi-submersibles at sea. The results demonstrate the accuracy of RAO function approach for specific WindFloat in Jonswap spectrum.
ARTICLE | doi:10.20944/preprints201709.0114.v1
Subject: Computer Science And Mathematics, Information Systems Keywords: WSN; IoT; seawater temperature prediction; marine aquaculture support
Online: 23 September 2017 (11:31:13 CEST)
Aquaculture is growing ever more important due to the decrease in natural marine resources and increase inworldwide demand. To avoid losses due to aging and abnormalweather, it is important to predict seawater temperature in order to maintain a more stable supply, particularly for high value added products, such as pearls and scallops. The increase in species extinction is a prominent societal issue. Furthermore, in order to maintain a stable quality of farmed fishery, water temperature should be measured daily and farming methods altered according to seasonal stresses. In this paper, we propose an algorithm to estimate seawater temperature in marine aquaculture by combining seawater temperature data and actual weather data.
ARTICLE | doi:10.20944/preprints202306.0083.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: Padina boergesenii; Marine macroalgae; Cosmetics; HRLCMS-QTOF; GCMS; FTIR
Online: 1 June 2023 (11:50:52 CEST)
The cosmetic industry recognizes the importance of natural sources for functional active constit-uents in meeting consumer expectations for safer and more sustainable beauty care products. Ma-rine macroalgae have emerged as promising resources, offering diverse bioactive constituents with potential applications in cosmetics. In this study, we investigated the biochemical profile of Padina boergesenii, a marine macroalga, using various methods to assess its potential as a cosmetic ingre-dient. The Fourier Transform Infrared (FTIR) analysis revealed the presence of distinct bioactive functional groups associated with numerous skin-beneficial compounds. Furthermore, the ethanolic and methanolic extracts of P. boergesenii were subjected to Gas Chromatography-Mass Spectrom-etry (GC-MS) analysis, which identified a total of six and fifteen significant phytocompounds, re-spectively. Additionally, a comprehensive phytochemical profiling of P. boergesenii was performed using High-Resolution Liquid Chromatography-Mass Spectrometry Quadrupole Time-of-Flight (HRLCMS-Q-TOF), highlighting the presence of various terpenoids, alkaloids, peptides, fatty acids, derivatives, and coumarins with potential cosmetic applications. To further assess its potential as a cosmetic ingredient, P. boergesenii was subjected to several additional estimations. Pigment estima-tion revealed the presence of specific pigments, while the determination of total phenol content and total protein content highlighted the richness of these bioactive components. The antioxidant analysis using the DPPH method demonstrated the antioxidant potential of P. boergesenii extracts, suggesting their ability to combat oxidative stress-related skin damage. Moreover, the tyrosinase inhibition assay indicated the inhibitory effect of P. boergesenii extracts on tyrosinase activity, which is relevant for addressing hyperpigmentation concerns. Furthermore, the elemental composition of P. boergesenii was evaluated using Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), revealing that silicon (Si) exhibited the highest concentration among the measured elements, while copper (Cu) displayed the lowest concentration. Additionally, HRLCMS-Q-TOF analysis was employed to quantify 21 amino acids, with aspartic acid exhibiting the highest con-centration (2034.99 nmol/mL), and tyrosine demonstrating the lowest concentration (233.26 nmol/mL). The accuracy of all the measured elements and amino acids was deemed acceptable. Taken together, the findings of this study highlight the potential of P. boergesenii as an effective ingredient for enhancing skin health. The incorporation of seaweed-based bioactive components, such as P. boergesenii, into cosmetic products is increasingly common due to their beneficial effects on the skin. Further exploration of the potential applications of P. boergesenii in the cosmetics in-dustry is warranted to harness its valuable bioactive properties.
ARTICLE | doi:10.20944/preprints202212.0135.v1
Subject: Engineering, Civil Engineering Keywords: Hydrodynamic model; marine and coastal tourism; analysis hierarchy process
Online: 7 December 2022 (14:47:31 CET)
Poso regency, Central Sulawesi, Indonesia, has a coastal area that has marine tourism potential to be developed. It is expected that marine tourism can bring socio-economic impact to the com-munity. This research was conducted with the objective of assessing the suitability of the area to be developed as a marine and coastal tourism site to provide benefits to the coastal community. Hydrodynamic model will be used in this research as coastal area mapping. As an approach, Analysis Hierarchy Process (AHP) is utilized whose parameters consist of depth, coast type, coast width, brightness, current speed, water base materials, observation of dangerous biota and availability of fresh water. Based on the overall mapping area of 98,644 ha, the research results show that the area that can be utilized is 7,979 ha with a very suitable category, while there is an area of 1,045 ha which can still be classified in the appropriate category.
ARTICLE | doi:10.20944/preprints202107.0232.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Kuwait; Arabian Gulf; Remote Sensing; ChlorophyII-a; Marine Biogeography
Online: 9 July 2021 (15:49:04 CEST)
The concentration of chlorophyll-a (chlor-a) is an important indicator of marine water quality, as it is considered an indicator of the phytoplankton density in a specific area. Remote sensing techniques have been developed to measure the near-surface concentration of chlor-a in water across the correlation between spectral bands and in situ data. This algorithm applies to sensors of varying spatial, temporal and spectral resolutions. However, in this study, chlor-a level 2 and 3 products of SNPP – VIIRS spectrometer (Equation OC3) of NASA OceanColor suite was relied upon to study the spatial and temporal distribution of chlor-a concentration in the Arabian Gulf (also known as the Persian Gulf) and the State of Kuwait’s water (located to the north-eastern part of the Arabian Gulf) from 2012 to 2019. Ground truthing points (n = 192) matched to the level 2 products have been used to build an empirical model and cross-validate it. The correlation was positive where was 0.79 and the validation RMSE was = ± 0.64 mg/m-3. The derived algorithm was then applied to chlor-a level 3 seasonal products. Additionally, the chlor-a concentration values of Kuwaiti waters have been enhanced using the IDW algorithm to increase the spatial resolution, as it is considered as a small area compared to the spatial resolution of level 3 chlor-a products. The model derived from IDW was tested using the Mann Whitney test (Sig = 0.948 p > 0.01). However, the result showed that the chlor-a concentration is higher in Kuwait Bay compared to Kuwaiti water, and it is higher in Kuwaiti water compared to the Arabian Gulf. The coasts have higher concentrations too, when compared to the open water. Generally, the chlor-a increases in winter and makes a semi-regular cycle during the years of study; this cycle is more regular in the Gulf’s waters than in Kuwait’s.
ARTICLE | doi:10.20944/preprints202107.0170.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Marine Isotope Stage 3; sea level; tectonics; GIA; Calabria
Online: 7 July 2021 (08:42:48 CEST)
Investigation of sea-level positions during the highly-dynamic Marine Isotope Stage 3 (MIS 3: 29-61 kyrs BP) proves difficult because: i) in stable and subsiding areas, coeval coastal sediments are currently submerged at depths of few to several tens of meters below present sea level; ii) in uplifting areas, the preservation of geomorphic features and sedimentary records is limited due to the erosion occurred during the Last Glacial Maximum (LGM) with sea level at depth of -130 m, followed by marine transgression that determined the development of ravinement surfaces. This study discusses previous research in the Mediterranean and elsewhere, and describes new fossiliferous marine deposits laying on metamorphic bedrock of Cannitello (Calabria, Italy). Radiocarbon ages of marine shells (about 43 kyrs cal BP) indicate that these deposits, presently between 28 and 30 meters above sea level, formed during MIS 3.1. Elevation correction of the Cannitello outcrops (considered in an intermediate-to-far-field position with respect to the ice sheet) with the local vertical tectonic rate and Glacial Isostatic Adjustment (GIA) rate allows to propose a revision of the eustatic depth for this highstand. Our results are consistent with recently proposed estimates based on a novel ice sheet modelling technique.
ARTICLE | doi:10.20944/preprints202007.0615.v1
Subject: Engineering, Marine Engineering Keywords: Bathymetry; marine renewables; seabed inspection; high resolution survey; sonar
Online: 25 July 2020 (17:01:00 CEST)
Marine renewable energy technologies have a great potential in supplying clean electricity to millions of people across the globe, if technical and economic conditions are in right. So far, ocean energy projects are commonly started by SMEs or educational institutions with limited budgets. Therefore, any effort to reduce expenses is of great value. One of the areas involving substantial expenses are the inevitable seabed inspection prior to deployment of marine renewable energy device. Detailed seabed inspections can also reduce the risk of associated with deployment of structures on uneven seabed, especially marine renewable energy devices with gravity foundations. By reducing the costs and risks of such surveys prior and during the installation phases, the feasibility of marine renewable energy projects can be more favoured and competitive. In this perspective, this study proposes a cost and time effective technique for seabed surveys. The proposed technique involves the use of high precision and inexpensive sonar systems and underwater optical cameras integrated into a versatile and compact subsea monitoring platform. It also involves simple and practical data acquisition and processing protocols that do not requires hi expertise for operation. The results obtained showed that high resolution bathymetric maps and detailed seabed inspections imagery can be acquired. This study concludes that a simple and inexpensive subsea monitoring platform comprising a multibeam, dual beam and video cameras can be effective for high resolution seabed inspection and bathymetric measurements for marine energy applications.
ARTICLE | doi:10.20944/preprints201911.0239.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: edible marine alga; anticancer; hizikia fusiformis; saringosterol acetate; apoptosis
Online: 20 November 2019 (11:19:19 CET)
Hizikia fusiformis is a common, edible marine alga found in Asia. Although the anticancer activity of its extracts has previously been investigated, its active compounds have not been identified. In this study, saringosterol acetate (SA) was isolated from H. fusiformis extracts by centrifugal partition chromatography (CPC) system (two phase solvents condition: n-hexane:ethyl acetate/methanol:water = 5:3:7:1, v/v), exhibited anticancer effects in the human lung adenocarcinoma epithelial cell line, A549, by inducing apoptosis and sub-G1 phase cell cycle arrest. In addition, SA increased the expression of the pro-apoptotic proteins, Bax and cleaved caspase 3, and decreased that of the anti-apoptotic protein Bcl-xL. Although, SA did not affect the expression of p53, induces expression of Bid and caspase 8. In conclusion, we suggested that SA induces apoptosis against A549 cells via Bid and caspase 8 dependent pathway.
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: secondary metabolites; microbial diversity; metabolomics; molecular network; marine bacteria
Online: 19 October 2019 (02:01:18 CEST)
Rocas Atoll is a unique environment in the Equatorial Atlantic Ocean, hosting a large number of endemic species and studies on the chemical diversity emerging from this biota are rather scarce. Therefore, the present work aims to assess the metabolomic diversity and pharmacological potential of the microbiota from Rocas Atoll. A total of 76 bacteria were isolated and cultured in liquid culture media to obtain crude extracts. About one third (34%) of these extracts were considered cytotoxic against human colon adenocarcinoma HCT-116 cell line. 16S rRNA gene sequencing analysis revealed that the bacteria producing cytotoxic extracts are mainly from the Actinobacteria phylum, including Streptomyces, Salinispora, Nocardiopsis and Brevibacterium genera, and in a smaller proportion from Firmicutes phylum (Bacillus). The search in the GNPS spectral library unveiled a high chemodiversity being produced by these bacteria, including rifamycins, antimycins, desferrioxamines, ferrioxamines, surfactins, surugamides, staurosporine and saliniketals, along with several unidentified compounds. Using an original approach, molecular network successfully highlighted groups of compounds responsible for the cytotoxicity of crude extracts. DEREPLICATOR+, a recently developed in silico tool (GNPS), allowed the identification of derivatives of the macrolide novonestimycin, as the cytotoxic compounds into the extracts produced by Streptomyces BRB-298 and BRB-302. Overall, these results highlighted the pharmacological potential of bacteria from this singular Atoll.
ARTICLE | doi:10.20944/preprints201908.0255.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: anthropogenic activities; coastal pollution; marine litter; Nigeria environment; plastics
Online: 25 August 2019 (16:42:58 CEST)
The abundance, distribution and composition of marine debris (> 5 cm) and small microplastics (11 μm) from five rivers in South Eastern, Nigeria was investigated. This study provided the first assessment of the type and quantity of marine litter and microplastics in Nigeria. A total of 3487 macrodebris items/m2 were counted with the following distribution; plastics (59 %) > metal (10 %) > cloth (7 %), paper /cardboard (7 %), rubber (7 %) > glass/ceramics (5 %), medical and agro-based waste (3 %) > wood (2 %). The cleanliness of the river assessed with clean coast index (CCI) ranged from “very clean” at Okumpi and Obiaraedu river to “extremely dirty” at Nwangele river. Microplastics abundance ranged from 440 to 1556 particles/L, with high accumulation at downstream. Fragment shape was most abundant while fiber and film followed. The distribution of plastic types was; PET (29 %) > PE (22 %) > PVC (16 %) > PP (14 %) > other (6 %) respectively. Significant relationship was found between the total abundances of microplastics and different macrodebris groups suggesting that microplastics were abundant in areas where the macrodebris abundance was high. Our results provide baseline information for future assessments. Management actions should focus on input prevention including proper waste management, recycling of plastics, and strict penalties for illegal dumping of wastes.
REVIEW | doi:10.20944/preprints201905.0063.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: biotechnologies; marine bacteria; secondary metabolites; nonribosomal biosynthesis; antibacterial strategies
Online: 6 May 2019 (12:15:50 CEST)
The highly dangerous trend of escalating bacterial resistance to modern antibiotics has evolved in recent decades, with increasingly more drug-resistant strains of pathogens emerging and spreading each year. This poses a threat to not only public health, but also to entire mankind. Marine bioresources, considered as a promising alternative to traditional antibiotics and a valuable source of biologically active compounds with high pharmacological potential, now attract increasing attention of researchers. Modern biotechnology combines the genetic engineering methods and the unusual biosynthetic pathways utilized by marine microorganisms to produce natural antibiotics. The goal of this review is to summarize the latest trends in searching for new natural antimicrobial agents based on secondary metabolites of marine bacteria. The targeted control of biosynthesis mechanisms using the metabolic engineering methods in order to create hybrid peptide synthetases or to obtain hybrid peptides by disrupting the target gene of nonribosomal synthesis becomes a noteworthy trend in modern biotechnology. This pathway is not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the exocrine activity of pathogenic bacteria and, consequently, their viability.
ARTICLE | doi:10.20944/preprints201811.0394.v3
Subject: Engineering, Electrical And Electronic Engineering Keywords: marine current turbine; blade attachment; sparse autoencoder; softmax regression
Online: 12 February 2019 (09:59:09 CET)
The development and application of marine current energy are attracting more and more attention around the world. Due to the hardness of its working environment, it is important and difficult to study the fault diagnosis of a marine current generation system. In this paper, an underwater image is chosen as the fault-diagnosing signal, after different sensors are compared. This paper proposes a diagnosis method based on the sparse autoencoder (SA) and softmax regression (SR). The SA is used to extract the features and SR is used to classify them. Images are used to monitor whether the blade is attached by benthos and to determine its corresponding degree of attachment. Compared with other methods, the experiment results show that the proposed method can diagnose the blade attachment with higher accuracy.
ARTICLE | doi:10.20944/preprints202306.0549.v1
Subject: Engineering, Marine Engineering Keywords: Armor unit; Hydraulic Stability; Hydraulic performance; Turbulence; Roughness; Marine structures
Online: 7 June 2023 (12:07:44 CEST)
The newly developed friction-interlocking armor unit, called ‘Double cube’ (DC), has been designed to improve the performance of the concrete armor unit used in river/marine structures against currents/waves actions. DC unit, is an octagonal-shaped block, made up of two parts: an upper cube set on a lower base that is either square or octagonal in shape. The innovative design aims to provide a good performance in terms of stability, high tolerance placement with various contact points and ease of placement. DC’s shape and placement enhance the stability by bringing the center of gravity closer to the underlayer and providing a large contact surfaces with surrounding blocks that reduce the chance of extraction and limit movements (rocking, lifting) via "keystone" effect. The characteristics of this new unit provides a relatively high hydraulic stability number for the armor layer (NS=2.9), a favorable hydraulic performance due to energy dissipation from turbulence and aeration, as well as a high roughness coefficient (γf≈0.46) helping to reduce the overtopping.
ARTICLE | doi:10.20944/preprints202305.0185.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: EPA-DHA; marine oils; FTIR spectra; chemometrics; partial least square
Online: 4 May 2023 (04:17:19 CEST)
Omega-3 fatty acids (ω-3 FAs) are important fatty acids having the beneficial roles in human health including reducing blood pressure, lowering the risk of cardiovascular disease and exerting anti-inflammation activities. Omega-3 FAs were mainly found in fish oils, therefore, determination of these FAs is very important. This study highlighted the employment of FTIR spectroscopy combined with multivariate data analysis for determination of ω-3 FAs in fish oils. Fish oils were obtained from the extraction of corresponding fishes and subjected to purification. The oils were further subjected to FTIR spectroscopic measurement at mid infrared region (4000-450 cm-1). Fatty acid compositions of ω-3 FAs namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were determined using gas chromatography with flame ionization (GC-FID), and the results from GC-FID were used as actual values. Two multivariate regressions along with wavenumbers regions or their combinations were optimized and compared to provide the best condition for prediction of EPA and DHA in fish oils. The results showed that partial least square regression (PLSR) was suitable for prediction of DHA applying the variable of absorbance values of the second derivative spectra, with the values of coefficient of determination (R2) of 0.9916 and 0.9316 in calibration and validation models, respectively. The values of root mean square error of calibration (RMSEC) and root mean square error of prediction (RMSEP) obtained were 0.789 and 2.53. While, prediction of EPA was performed using principal component regression with R2 value of > 0.72 and low values of RMSEC and RMSEC. It can be concluded that the combination of FTIR spectra and multivariate regression provides the effective tools and alternative GC-FID method for the prediction of EPA and DHA in fish oils.
ARTICLE | doi:10.20944/preprints202303.0374.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: marine algae; lambda-carrageenan; oligosaccharides; heparanase; migration; anti-cancer agents
Online: 21 March 2023 (09:16:48 CET)
Oligosaccharides derived from λ-carrageenan (λ-COs) are gaining interest in the cancer field. They have been recently reported to regulate heparanase (HPSE) activity, a protumor enzyme involved in cancer cell migration and invasion, making them very promising molecules for new therapeutic applications. However, one of the specific features of commercial λ-carrageenan (λ-CARs) is that they are in fact heterogeneous mixtures of different CARs families, and are named according to the thickening purpose of the product which does not reflect the real com-position. Consequently, this can limit their use in a clinical grade. To address this issue, six commercial λ-CARs were compared for which differences in their physiochemical properties were shown. Then, a H2O2-assissed radical depolymerization was applied to each commercial source and the number and weight averaged molar masses (Mn and Mw) and sulfation degree (DS) of the λ-COs produced over time were determined. By adjusting the depolymerization time for each product, almost comparable λ-CO formulations could be obtained in term of molar masses and DS, that ranged within previously reported values suitable for anti-tumor proper-ties. However, when the anti-HPSE activity of these new λ-COs was screened, small changes that could not be attributed only to their small length or DS changes between them were found, suggesting a role of other features such as differences in the initial mixture composition. Further structural MS and NMR analysis revealed indeed qualitative and semi-quantitative differences between the molecular species, especially in the proportion of the anti-HPSE λ-type, other CARs types and adjuvants, but also showed that H2O2-based hydrolysis induced sugar degradation. Finally, when the effects of λ-COs were assessed in an in vitro migration cell-based model, they seemed more related to the proportion of other CAR types in the formulation than to their λ-type-dependent anti-HPSE activity.
ARTICLE | doi:10.20944/preprints202212.0419.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: marine organisms; chlorins; photodynamic therapy; brittle stars; Ophiuroidea; phototoxicity; cancer
Online: 22 December 2022 (05:02:21 CET)
A Pacific brittle star Ophiura sarsii has previously been shown to produce a chlorin (3S,4S)-14-Ethyl-9-(hydroxymethyl)-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid (ETPA) (1) with potent phototoxic activities making it applicable to photodynamic therapy. Using extensive LC-MS metabolite profiling, molecular network analysis and targeted isolation with de novo NMR structure elucidation, we here identify five additional chlorin compounds from O. sarsii and its deep-sea relative O. ooplax: 10S-Hydroxypheophorbide a (2), Pheophorbide a (3), Pyropheophorbide a (4), (3S,4S,21R)-14-Ethyl-9-(hydroxymethyl)-21-(methoxycarbonyl)-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid (5), and (3S,4S,21R)-14-Ethyl-21-hydroxy-9-(hydroxymethyl)-4,8,13,18-tetramethyl-20-oxo-3-phorbinepropanoic acid (6). Chlorins 5 and 6 have not been previously reported in natural sources. Interestingly, low amounts of chlorins 1-4 and 6 could also be identified in a distant species, the basket star Gorgonocephalus cf. eucnemis, demonstrating that chlorins are produced by a wide spectrum of marine invertebrates of the class Ophiuroidea. Following purification of these major Ophiura chlorin metabolites, we discovered the high singlet oxygen quantum yield upon their photoinduction and their strong phototoxicity against a panel of cancer cell lines. These studies identify an arsenal of brittle star chlorins as powerful natural photosensitizers with potential photodynamic therapy applications.
ARTICLE | doi:10.20944/preprints202204.0005.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: genome mining; marine environments; molecular networking; bacterial extremophiles; secondary metabolites
Online: 1 April 2022 (10:21:11 CEST)
Understanding extremophiles and their usefulness in biotechnology involves studying their habitat, physiology and biochemical adaptations , as well as their ability to produce biocatalysts, in environments that are still poorly explored. In northwestern Peru, which saline lagoons of marine origin Pacific Ocean, the other site from the coast of Brazil of the Atlantic Ocean. Both environments are considered extreme. The objective of the present work was to compare two different strains isolated from these extreme environments at the metabolic level using molecular network methodology through the Global Natural Products Molecular Social Network (GNPS). In our study, the MS/MS spectra from the network were compared with GNPS spectral libraries, where the metabolites were annotated. Differences were observed in the molecular network presented in the two strains of Streptomyces spp. coming from these two different environments. Within the annotated compounds from marine bacteria, the metabolites characterized for Streptomyces sp. B-81 from Peruvian marshes were lobophorins A (1) and H (2), as well as divergolides A (3), B (4) and C (5). Streptomyces sp. 796.1 produced different compounds, such as glucopiericidin A (6) and dehydro-piericidin A1a (7). The search for new metabolites in underexplored environments may therefore reveal new metabolites with potential application in different areas of biotechnology.
ARTICLE | doi:10.20944/preprints202203.0405.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: α-amylase inhibitors; diabetes; hemi-pyocyanin; marine discards; microbial conversion
Online: 31 March 2022 (10:47:24 CEST)
α-amylase inhibitors (aAIs) have been proved efficient for the management of type 2 diabetes. This study aimed to search the potential aAIs produced by microbial fermentation. Among various bacterial strains, Pseudomonas aeruginosa TUN03 was found as a potential aAI - producing strain, and shrimp heads powder (SHP) was screened as the most suitable C/N source for fermentation. P. aeruginosa TUN03 exhibited the highest aAIs productivity (3100 U/mL) in the medium containing 1.5% SHP with the initial pH of 7-7.5, and fermentation was performed at 27.5 °C in 2 days. Further, aAIs compounds were investigated for scale-up production in a 14 L – bioreactor system, and the results highlighted high yield (4200 U/mL) in much shorter fermentation time (12 h) compared to fermentation in flasks. The bioactivity-guided purification resulted in the isolation of one major target compound. This active compound was confirmed as hemi-pyocyanin (HPC), with good purity, via using high-performance liquid chromatography and gas chromatography-mass spectrometry. Notably, HPC demonstrated potent activity comparable to acarbose, a commercial antidiabetic drug; this is the first-ever report of aAI activity of HPC. The docking study indicated that HPC inhibits α-amylase via binding to amino acid Arg421 at the biding site on enzyme α-amylase with good binding energy (-9.3 kcal/mol) and creating two linkages of H-acceptor.
REVIEW | doi:10.20944/preprints202110.0057.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: impacts; microplastics; marine environment; single-use plastics; co-management initiatives
Online: 4 October 2021 (12:23:39 CEST)
Threats emerging from microplastics pollution in the marine environment have received much global attention. This review assessed sources, fate, and impacts of microplastics in marine ecosystems and identified gaps. Most studies document ubiquity of microplastics and associated environmental effects. Effects include impacts to marine ecosystems, risks to biodiversity, and threats to human health. Microplastic leakage into marine ecosystems arises from plastic waste mismanagement and a lack of effective mitigative strategies. This review identified a scarcity of microplastics mitigation strategies across different stakeholders. Lack of community involvement in microplastic monitoring or ecosystem conservation exists due to limited existence of stakeholder co-management initiatives. Although some management strategies exist for controlling the effects of microplastics (often implemented by local and global environmental groups); a standardized management strategy to mitigate microplastics in coastal areas is urgently required. There is a need to identify focal causes of microplastic pollution in the marine environment through further environmental research. This would extend to creating more effective policies as well as harmonized and extended efforts of educational campaigns and incentives for counteraction and plastic waste reduction, while mandating stringent penalties for polluting the marine environment. This will help reduce microplastic leakage into the environment.
REVIEW | doi:10.20944/preprints202107.0273.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Plastisphere; Plastic biofilms; Microbial communities; Marine plastic pollution; Plastic biodegradation
Online: 12 July 2021 (22:12:28 CEST)
The microbial colonisers of plastics – the ‘plastisphere’ – can affect all interactions that plastics have with their surrounding environments. While only specifically characterised within the last 10 years, at the beginning of 2021 there were 140 primary research and 65 review articles that investigate at least one aspect of the plastisphere. We gathered information on the locations and methodologies used by each of the primary research articles, highlighting several aspects of plastisphere research that remain understudied: (i) the non-bacterial plastisphere constituents; (ii) the mechanisms used to degrade plastics by marine isolates or communities; (iii) the capacity for plastisphere members to be pathogenic or carry antimicrobial resistance genes; and (iv) meta-OMIC characterisations of the plastisphere. We have also summarised the topics covered by the existing plastisphere review articles, identifying areas that have received less attention to date – most of which are in line with the areas that have fewer primary research articles. Therefore, in addition to providing an overview of some fundamental topics such as biodegradation and community assembly, we discuss the importance of eukaryotes in shaping the plastisphere, potential pathogens carried by plastics and the impact of the plastisphere on plastic transport and biogeochemical cycling. Finally, we summarise the future directions suggested by the reviews that we have evaluated and suggest other key research questions.
REVIEW | doi:10.20944/preprints202106.0014.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: antitumor activity; natural compounds; glioma multiforme; brain tumors; marine species
Online: 1 June 2021 (09:59:08 CEST)
The search for new chemical compounds with antitumor pharmacological activity is a necessary process for creating more effective drugs for each specific malignancy type. This review presents the outcomes of screening studies of natural compounds with high anti-glioma activity. Despite significant advances in cancer therapy, there are still some tumors currently considered completely incurable including brain gliomas. This review covers the main problems of the glioma chemotherapy including drug resistance, side effects of common anti-glioma drugs, and genetic diversity of brain tumors. The main emphasis is made on the characterization of natural compounds isolated from marine organisms because taxonomic diversity of organisms in seawaters significantly exceeds that of terrestrial species. Thus, we should expect greater chemical diversity of marine compounds and greater likelihood of finding effective molecules with antiglioma activity. The review covers at least 15 classes of organic compounds with their chemical formulas provided as well as semi-inhibitory concentrations, mechanisms of action, and pharmacokinetic profiles. In conclusion, the analysis of the taxonomic diversity of marine species containing bioactives with antiglioma activity is performed noting cytotoxicity indicators and to the tumor cells in comparison with similar indicators of antitumor agents approved for clinical use as antiglioblastoma chemotherapeutics.
REVIEW | doi:10.20944/preprints202105.0572.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: microalgae; marine bacteria; quorum sensing signals; alkyl quinolones; microbial loop
Online: 24 May 2021 (13:34:11 CEST)
Quorum sensing (QS) describes a process by which bacteria can sense the local cell density of their own species, thus enabling them to coordinate gene expression and physiological processes on a community-wide scale. Small molecules called autoinducers or QS signals, which act as intraspecies signals, mediate quorum sensing. As our knowledge of QS has progressed, so too has our understanding of the structural diversity of QS signals, along with the diversity of bacteria conducting QS and the range of ecosystems in which QS takes place. It is now also clear that QS signals are more than just intraspecies signals. QS signals mediate interactions between species of prokaryotes, and between prokaryotes and eukaryotes. In recent years, our understanding of QS signals as mediators of algae–bacteria interactions has advanced such that we are beginning to develop a mechanistic understanding of their effects. This review will summarize the recent efforts to understand how different classes of QS signals contribute to the interactions between planktonic microalgae and bacteria in our oceans, primarily N-acyl-homoserine lactones, their degradation products tetramic acids, and 2-alkyl-4-quinolones. In particular, this review will discuss the ways in which QS signals alter microalgae growth and metabolism, namely as direct effectors of photosynthesis, regulators of the cell cycle, and as modulators of other algicidal mechanisms. Furthermore, the contribution of QS signals to nutrient acquisition is discussed, and finally how microalgae can modulate these small molecules to dampen their effects.
REVIEW | doi:10.20944/preprints202105.0010.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: Coral Reef Monitoring; Reef Health; Review; Hyperspectral Imaging; Marine Optics
Online: 3 May 2021 (16:10:43 CEST)
Monitoring the health of coral reefs is essential to understand the damaging impacts of anthropo-genic climate change. Non-invasive methods to survey coral reefs are the most desirable and op-tics-based surveys, ranging from simple photography to multispectral satellite imaging are well es-tablished. Herein, we review these techniques, focusing on their value for coral monitoring and health diagnosis. A new, low-cost hyperspectral imaging technique using linear variable filters is also described. This system is capable of simultaneously producing hyperspectral and photogrammetric outputs, which provides integrated information of reef structure and physiology.
ARTICLE | doi:10.20944/preprints202009.0694.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: food security; marine anthropogenic litter; microplastics; plastic pollution, seafood; Taiwan
Online: 28 September 2020 (17:49:45 CEST)
Microplastics have already been detected in various human foods, especially seafood. This problem should be especially pertinent to the Taiwanese public because a relatively high proportion of people‘s diet comes from seafood. We therefore present a pilot study of microplastic contamination of seafood products commonly consumed by Taiwanese people. We examined six batches of three seafood species for the presence of microplastics using FTIR spectroscopy. A total of 107 seafood individuals from three species (hard clam Meretrix lusoria, oyster Crassostrea gigas, Loligo squid Loliginidae spp.) weighing a total of 994 grams yielded a total of 100 microplastic particles consisting of nine different polymer types. 91% of microplastic particles were fragments which likely originated from fragmented plastic debris which was then consumed by the seafood species. The mean number of microplastics/kg was 87.9 microplastics/kg across the three examined species. Given that Taiwanese average about 10 kg of seafood consumption per year, we estimate that a few thousand microplastic particles are annually consumed on average. The methodology of this pilot study can now be used to conduct examinations of more seafood species and samples.
ARTICLE | doi:10.20944/preprints202005.0102.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: marine natural products; Laurencia; brominated sesquiterpenes; antimycobacterial; nontuberculous mycobacteria; tuberculosis
Online: 6 May 2020 (15:32:53 CEST)
Marine environments represent a great opportunity for the discovery of compounds with a wide spectrum of bioactive properties. Due to the privileged conditions of natural selection, marine natural products are subject to overcome the pressure put on identify novel drugs; not only in the case of newly discovered bioactive metabolites, but also in those previously known. Since drug resistance has caused an increase in infections caused by tuberculous and nontuberculous Mycobacteria, the re-evaluation of known bioactive metabolites has been suggested as a means to address this problem. In this sense, this study presents an evaluation of in vitro effect of laurinterol (1) and aplysin (2), two brominated sesquiterpenes isolated from Laurencia johnstonii against nine Mycobacterium tuberculosis strains and six nontuberculous mycobacteria. Laurinterol (1) exhibited good anti-tuberculous activity, especially against nontuberculous mycobacteria, being remarkable the effect against M. abscessus with MIC values lower than the reference drug imipenem. This study provides further evidence for the antimycobacterial activity of some sesquiterpenes from L. johnstonii, that can be considered an interesting lead compound for the discovery of novel antimycobacterial molecules to treat NTM infections.
ARTICLE | doi:10.20944/preprints201904.0183.v1
Subject: Engineering, Marine Engineering Keywords: marine growth; biofouling; wave loading; stochastic modeling; reliability; jacket structures
Online: 16 April 2019 (10:49:17 CEST)
The present paper deals with the stochastic modeling of bio-colonization for the computation of stochastic hydrodynamic loading on jacket-type offshore structures. It relies on a multidisciplinary study gathering biological and physical research fields that accounts of uncertainties at all the levels. Indeed, bio-colonization of offshore structures is a complex phenomenon with two major but distinct domains (i) marine biology whose processes are modeled with biomathematics methods and (ii) hydrodynamic processes. This paper aims to connect these two domains. It proposes a stochastic model for the marine organism’s growth and then continues with transfers for assessment of drag coefficient and forces probability density functions that accounts for marine growth evolution. A case study relies on the characteristics (growth and shape) of the blue mussel (Mytilus edulis) in northeastern Atlantic.
ARTICLE | doi:10.20944/preprints201807.0549.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Smenospongia aurea, -pyrone, polypropionate, marine sponges, secondary metabolites, signaling molecules.
Online: 27 July 2018 (17:00:51 CEST)
The organic extract of the Caribbean sponge Smenospongia aurea has been shown to contain an array of novel chlorinated secondary metabolites derived from a mixed PKS-NRPS biogenetic route, such as the smenamides. Here we report the presence of a biogenetically different compound, smenopyrone (1), a polypropionate containing two -pyrone rings. The structure of smenopyrone, including its relative and absolute stereochemistry, was determined by spectroscopic analysis (NMR, MS, ECD) supported by comparison with model compounds from the literature. Pyrone polypropionates are unprecedented in marine sponges, but are commonly found in marine mollusks, where their biosynthesis by symbiotic bacteria has been hypothesized and at least in one case demonstrated. As pyrones have recently been recognized as bacterial signaling molecules, we speculate that smenopyrone could mediate inter-kingdom chemical communication between S. aurea and its symbiotic bacteria.
REVIEW | doi:10.20944/preprints201806.0093.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: marine organisms; carbohydrate; glycoside; antioxidant; anticoagulant; anti-inflammatory; antitumor; antimicrobial
Online: 6 June 2018 (12:32:12 CEST)
The oceans harbor a great diversity of organisms, and have been recognized as an important source of new compounds with nutritional and therapeutic potential. Among these compounds, carbohydrate-based compounds are of particular interest because they exhibit numerous biological functions associated with their chemical diversity. This gives rise to new substances for the development of bioactive products. Many are the known applications of substances with glycosidic domains obtained from marine species. This review covers the structural properties and the current findings on the antioxidant, anti-inflammatory, anticoagulant, antitumor and antimicrobial activities of medium and high molecular-weight carbohydrates or glycosylated compounds extracted from various marine organisms.
REVIEW | doi:10.20944/preprints201711.0038.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: phospholipids; atherosclerosis; inflammation; anti-inflammatory; dairy; marine; meat; egg; nutrition
Online: 6 November 2017 (10:30:12 CET)
In this review paper, the latest literature on the functional properties of phospholipids in relation to inflammation and inflammation-related disorders has been critically appraised and evaluated. The paper is divided into three sections: Section one addresses the relationship between the anti-inflammatory bioactivities of different phospholipids in relation to their structures and compositions. Sections two and three are dedicated to the structures, functions and anti-inflammatory properties of dietary phospholipids from animal and marine sources. Most of the dietary phospholipids of animal origin come from meat, egg and dairy products. To date, there is very limited work published on meat phospholipids, undoubtedly due to the negative perception that meat consumption is an unhealthy option due to its putative associations with several chronic diseases. These assumptions are addressed with respect to the phospholipid composition of meat products. Recent research trends indicate that dairy phospholipids possess anti-inflammatory properties, which has led to an increased interest into their molecular structures and reputed health benefits. Finally, the structural composition of phospholipids of marine origin is discussed. Extensive research has been published in relation to ω-3 polyunsaturated fatty acids (PUFAs) and inflammation, however this research has recently come under scrutiny and has proved to be unreliable and controversial in terms of the therapeutic effects of ω-3 PUFA, which are generally in the form of triglycerides and esters. Therefore, this review focuses on recent publications concerning marine phospholipids and their structural composition and related health benefits. Finally, the strong nutritional value of dietary phospholipids are highlighted with respect to marine and animal origin and avenues for future research are discussed.
ARTICLE | doi:10.20944/preprints202306.0399.v1
Subject: Social Sciences, Behavior Sciences Keywords: scuba diving; volunteers; marine environmental protection; mediating effects; environmentally responsible behavior
Online: 6 June 2023 (07:49:27 CEST)
Volunteer scuba divers have become indispensable stakeholders in marine environmental protection, as their educational knowledge and environmental awareness create environmentally responsible attitudes and behaviors, which are the key elements to promote the sustainable development of marine environments. This study used the C-A-B model to examine the relationship between environmental knowledge, environmental sensitivity, destination social responsibility, and environmentally responsible behaviors of volunteer scuba divers. It also explored the mediating effects of destination social responsibility and first-time and repeat volunteers. In order to achieve the research purpose, this study adopted quantitative research to verify the research structure, proposed the hypotheses and prepared a questionnaire with reference to relevant previous studies. A total of 238 Taiwan marine volunteer scuba divers were selected as the subjects by intentional sampling, and the effective questionnaire recovery rate is 92.9%. Structural equation was used to verify the model of environmentally responsible behaviors of volunteer scuba divers, as based on the C-A-B model. This study found that environmental knowledge had a significant impact on destination social responsibility, and destination social responsibility had a significant impact on environmentally responsible behaviors. Destination social responsibility also had the effect of complete mediation on the model. In addition, the first-time and repeat volunteers had a significant mediating effect on the causal relationship between environmental knowledge and environmentally responsible behaviors, as well as between environmental sensitivity and environmentally responsible behaviors. The explanatory power of the overall model on the environmentally responsible behaviors of volunteer scuba divers is 69.0%, and their knowledge, sense of responsibility, experience, and level of involvement can be regarded as the determinants of their environmentally responsible behaviors.
ARTICLE | doi:10.20944/preprints202305.0474.v1
Subject: Public Health And Healthcare, Other Keywords: marine toxins; TTX; Saxitoxins; pufferfish; not indigenous species; Mediterranean; risk assessment
Online: 8 May 2023 (08:38:06 CEST)
Pufferfish (Tetraodontidae) inhabiting the Mediterranean Sea can represent an emerging public health risk due to the possible accumulation of marine neurotoxins (TTXs and STXs) in their tissues. In this study, the presence of pufferfish species in the Strait of the Sicily (Lampedusa Island, Italy) was investigated using a Citizen Science (CS) approach involving local fishermen. A sub-group of specimens collected were sent to the National reference Laboratory on Marine Biotoxins for de-termining the presence of TTXs using a validated HILIC-MS/MS method on fish tissue. The STXs presence was also screened in some specimens. Overall, 56 specimens, identified as Sphoeroides pachygaster (Müller &Troschel, 1848) were collected. Data on specimen total length, body weight, fishing method, catch area (with relative depth temperature and salinity) were analyzed and compared with the S. pachygaster records reported in Guardone et al. (2018), which were appro-priately updated until 2022. All the analysed tissues were found to be negative for both TTXs and STXs. The key role of the CS in monitoring potentially toxic marine species was proved. Outcomes from this study, the first investigating the toxicity of S. pachygaster in Italian waters, may provide useful data for the proper assessment of this emerging risk
COMMUNICATION | doi:10.20944/preprints202304.1121.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Atlantic Goliath Grouper; Epinephelus itajara; extinction; overfishing; marine protected areas; monitoring
Online: 28 April 2023 (05:18:39 CEST)
The Atlantic Goliath Grouper Epinephelus itajara (Lichtenstein, 1822) is thought to occur on both sides of the Atlantic, from the Carolinas (USA) to Brazil in the western Atlantic, and from North Senegal to North Angola off West Africa in the eastern Atlantic. While there are fairly good data on their distribution in the western Atlantic, genetic verification of species status, confirmed occurrences, population status, fishing reports, and trade data are almost non-existent off West Africa. Part of the problem is that tropical West African countries lack a network of marine reserves that might protect this species. Add to this destruction of mangrove forests and other coastal habitats on which the species depends when in the post-larval and juvenile stages coupled heavy pollution and intense overfishing and it becomes clear that their survival is deeply threatened. The focus of this paper is to describe all of the known historical data and examine all current data to better evaluate their present status.
ARTICLE | doi:10.20944/preprints202212.0008.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID-19; molecular docking; ADMET; marine natural products; Chrysophaentin A; Hymenidin
Online: 1 December 2022 (03:51:30 CET)
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have triggered a recent pandemic of respiratory disease and affected almost every country all over the world. A large amount of natural bioactive compounds is under clinical investigation for various diseas-es. Especially, marine natural compounds are gaining more attention in the new drug develop-ment process. The present study has aimed to identify potential marine-derived inhibitors against the target proteins of COVID-19 using a computational approach. Currently, 16 marine clinical-level compounds were selected for computational screening against the four SARS-CoV-2 main proteases. Computational screening resulted from the best drug candidates for each target based on the binding affinity scores and amino acid interactions. Among these, five marine-derived compounds namely Chrysophaentin A (-6.6 kcal/mol), Geodisterol sulfates (-6.6 kcal/mol), Hymenidin (-6.4 kcal/mol), Plinabulin (-6.4 kcal/mol) and Tetrodotoxin (-6.3 kcal/mol) expressed the minimized binding energy and molecular interactions such as covalent and hydrophobic interactions to the SARS CoV-2 Main Protease. Using Molecular dynamic stud-ies, the Root-Mean-Square Deviation (RMSD), Root-Mean-Square Fluctuation (RMSF), Radius of Gyration (ROG), and Hydrogen bonds (H-Bonds) values were calculated for SARS-CoV-2 Main Protease with Hymenidin docked complex. Additionally, in silico Druglikeness and pharmaco-kinetic property assessments of the compounds demonstrated favorable druggability. These re-sults suggested that marine natural compounds are capable of fighting SARS-CoV-2. Further, in vitro and in vivo studies need to be carried out to confirm their inhibitory potential.
ARTICLE | doi:10.20944/preprints202206.0328.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: mangrove forests; Marine Protected Areas; α-diversity; β-diversity; multivariate analyses
Online: 24 June 2022 (03:28:50 CEST)
Differences in fish assemblages’ structure and their relation with environmental variables (due to the variations in sampled seasons, habitats, and zones), were analyzed in two adjacent estuaries on the north Pacific coast of Mexico. Environmental variables and fish catches were registered monthly between August 2018 and October 2020. Multivariate analyses were conducted to define habitats and zones based on their environmental characteristics, and the effect of this variability on fish assemblages’ composition, biomass, and diversity (α and β) was evaluated. A total of 12,008 fish individuals of 143 species were collected using different fishing nets. Multivariate analyses indicated that fish assemblages’ structure was different between zones due to the presence, height, and coverage of distinct mangrove species. Additionally, factors such as depth and salinity showed effects on fish assemblages’ diversity (α and β-nestedness), which presented higher values in the ocean and remained similar in the rest of the analyzed zones and habitats. These results and the differences in species replacement (β-turnover) indicate the singularity of fish assemblages at estuaries (even in areas very close to the ocean), and the necessity to establish local management strategies for these ecosystems.
ARTICLE | doi:10.20944/preprints202107.0572.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: CFPHV; ChHV5; phylogenetics; phylogenomics; viral evolution and diversity; marine turtles; fibropapillomatosis
Online: 26 July 2021 (11:58:37 CEST)
The spreading global sea turtle fibropapillomatosis (FP) epizootic is threatening some of Earth’s ancient reptiles, adding to the plethora of threats faced by these keystone species. Understanding this neoplastic disease, and its likely aetiological pathogen, chelonid alphaherpesvirus 5 (ChHV5), is crucial to understand how the disease impacts sea turtle populations and species and the future trajectory of disease incidence. We generated 20 ChHV5 genomes, from three sea turtle species, to better understand the viral variant diversity and gene evolution of this oncogenic virus. We revealed previously underappreciated genetic diversity within this virus (with an average of 2,035 single nucleotide polymorphisms [SNPs], 1.54% of the ChHV5 genome) and identified genes under the strongest evolutionary pressure. Furthermore, we investigated the phylogeny of ChHV5 at both genome and gene level, confirming the propensity of the virus to be interspecific with related variants able to infect multiple sea turtle species. Finally, we revealed unexpected intra-host diversity, with up to 0.15% of the viral genome varying between ChHV5 genomes isolated from different tumours concurrently arising within the same individual. These findings offer important insights into ChHV5 biology and provide genomic resources for this oncogenic virus.
ARTICLE | doi:10.20944/preprints202107.0535.v1
Subject: Physical Sciences, Acoustics Keywords: Underwater noise modelling; decommissioning; explosives; sound exposure level; marine mammals; fish
Online: 23 July 2021 (10:41:33 CEST)
A simple underwater noise model suitable for use with explosive severance of well conductors and piles during the decommissioning of oil and gas subsea structures is introduced and evaluated against data from five projects in the US. This study focuses on a novel model for the determination of sound exposure levels. The model has been developed to enable determination of impact areas for marine mammals and fish. Simulated received underwater sound exposure levels were significantly correlated with measurements for all scenarios. The maximum total error achieved between simulations and measurements was 2.6%, suggesting that predictions are accurate to within 3% of the average measurement. A low relative bias was observed in the simulations when compared to measured values, suggesting only a small systematic underestimate (≤ 0.5% of average measurement) for most severance operations and a small overestimate (0.14%) for open water blasts.
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Transboundary management; biodiversity; species distributions; Exclusive Economic Zones; marine conservation; collaboration
Online: 20 May 2021 (10:14:11 CEST)
Marine species are declining at an unprecedented rate, catalyzing many nations to adopt conservation and management targets within their jurisdictions. However, marine species and the biophysical processes that sustain them are naive to international borders. An understanding of the prevalence of cross-border species distributions is important for informing high-level conservation strategies, such as bilateral or regional agreements. Here, we examined 28,252 distribution maps to determine the number and locations of transboundary marine plants and animals. Over 90% of species have ranges spanning at least two jurisdictions, with 58% covering more than ten jurisdictions. All jurisdictions have at least one transboundary species, with the highest concentrations of transboundary species in the USA, Australia, Indonesia, and the Areas Beyond National Jurisdiction. Distributions of mapped biodiversity indicate that overcoming the challenges of multinational governance is critical for a much wider suite of species than migratory megavertebrates and commercially exploited fish stocks—the groups that have received the vast majority of multinational management attention. To effectively protect marine biodiversity, international governance mechanisms (particularly those related to the Convention on Biological Diversity, the Convention on Migratory Species, and Regional Seas Organizations) must be expanded to promote multinational conservation planning, and complimented by a holistic governance framework for biodiversity beyond national jurisdiction.
ARTICLE | doi:10.20944/preprints202007.0624.v1
Subject: Environmental And Earth Sciences, Paleontology Keywords: Urbanization; Gulf of Trieste; Ostracods; Nutrients; Environmental stress; Marine Nature Reserve
Online: 25 July 2020 (19:00:43 CEST)
For the first time the distribution and modifications of living ostracod associations present in the Gulf of Trieste (GoT) in relation to the alterations caused by human activity in the last 20 years were investigated. The results were compared with the main chemico-physical parameters (especially nitrogen and phosphorus) measured over the same period, which can lead to a general decrease in environmental quality. For a more in-depth analysis of the changes recorded by ostracods in the last 50 years, a period in which eutrophication and anoxia increased, we revisited the study carried out by Masoli in the GoT in 1967. The results obtained made it possible to verify how over the last 20 years, ostracod assemblages have suffered a decrease both qualitatively and quantitatively. Most of the species recovered show characteristics of opportunism and tolerance to environmentally stressful conditions, high organic matter concentrations and oxygen deficiency. The ostracods analyzed in 1967 showed similar results with few dominant opportunistic species. We verified how ostracods recorded in GoT, similar to Mollusks and Foraminifera, the possible environmental crisis linked to the recurrence of mucilage and hypoxic events documented for the Gulf of Trieste in the last 50 years. Finally, a comparison with the best environmental conditions found in the Marine Nature Reserve of Miramare (MPA) allowed us to emphasize the important role of protected areas to avoid the loss of biodiversity due to urbanization.
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: marine mortar; multi-scale; interfacial behavior; strength; damage; on-line detection
Online: 7 May 2019 (11:38:17 CEST)
Marine mortar was the goal material and its multi-scale physical-chemical-mechanical characteristics were the principal interest in this study. The on-line multi-scale damage detection experiments art was designed to quantify the characteristics mathematically and graphically. The normal cylinder specimen with 70-day age was produced and investigated by dynamically global MSHCT scan and local detection of EDS, SEM and XRD. The experiments results indicated that the marine mortar offered the appreciable strength at the early age at least, although some saline minerals were generated during the preparation. The micro-interfacial behavior and the parental foci controlled the damage development of the marine mortar the performance of which was still the adjustable one by the composition optimization.
ARTICLE | doi:10.20944/preprints201809.0437.v2
Subject: Engineering, Industrial And Manufacturing Engineering Keywords: Fatigue; Delamination; Acoustic Emission; Failure Mechanisms; Composite Materials; Nanofibers, Marine Applications.
Online: 14 December 2018 (10:12:52 CET)
The use of high strength to weight ratio laminated composites is emerging in marine industry and applications as a very efficient solution for improving productivity. Nevertheless, delamination between the layers is a limiting factor for the wider application of laminated composites, as it reduces the stiffness and strengths of the structure. Interleaving nanofibrous mats between layers of composite laminates has been proved to be an effective method for improving composites delamination resistance. This paper aims to characterize the effect of interleaved nanofiber on mode I interlaminar properties and failure mechanisms when subjected to static and fatigue loadings. For this purpose, virgin and nanomodified woven laminates were subjected to Double Cantilever Beam (DCB) specimens. Static and fatigue tests were performed and the tests were monitored by acoustic emission technique. The mechanical results showed a 130% increase of delamination toughness for nanomodified specimens in the static loadings and more crack growth resistance in the fatigue loading. The AE results revealed that different type of failure mechanisms was the cause of these improvements for the modified specimens compared with the virgin ones.
REVIEW | doi:10.20944/preprints201811.0568.v1
Subject: Engineering, Energy And Fuel Technology Keywords: energy transition; sustainable development; efficiency energy; renewable energy; marine natural resources
Online: 26 November 2018 (03:50:26 CET)
The current energy policy recommends the idea of energy efficiency over fossil energy as a primary matter for the coming years. The kingdom of Morocco requires restructuring of its power equipment by increasing the percentage of renewable energy supplies, optimizing their systems and power storage. Therefore, increasing energy efficiency is an as important obligation as reducing the overall energy consumption. The purpose of this research is to present the energy transition in Morocco towards renewable energies and to assess the diversity of available marine natural resources. Recent research in conversion of ocean thermal energy, wave energy, tidal energy, offshore wind energy, and osmotic energy into power supply has started to encourage different technologies. This research has led to commercial deployment in some cases such as our 550 km long Mediterranean coast and 3000 km long Atlantic. This does not only result in fossil energies independency but also provides advantages like less cost and no pollution.
ARTICLE | doi:10.20944/preprints201810.0611.v1
Subject: Engineering, Marine Engineering Keywords: Autonomy; LOA; design; swarms; underwater vehicles; marine; Autonomous Job Analysis; canvas
Online: 25 October 2018 (15:33:12 CEST)
Several design methods and principles have been presented so far, in order to guide the design of autonomous operations. Putting the required efforts into learning and using the methods for designing autonomous operations is a daunting task. Experiences so far have shown that the use of methods meant to the help the design process are often ignored. One reason could be that the design guidelines are too complex and contain much information often not relevant for the project at hand, and therefore there is no easy way to distinguish what is important from what is not. This is an issue that needs to be solved with our approach. In this article, the Autonomous Job Analysis (AJA) method is presented. The proposed methodology is created in order to guide the design of autonomous operations in maritime systems by breaking them down in to sub-operations in order to reveal challenges, needs and limitations regarding autonomous behavior. The canvas contains the categories of the AJA method on a single page format -the canvas- and each category is supported with questions to be asked during the design procedure, as well as example answers. We will describe the AJA method and the AJA canvas in detail, and present a use case scenario of an autonomous operation in order to show how they can be applied. The particular use-case is the design of an autonomous operation for the detection, inspection and tracking of a waste water plume.
ARTICLE | doi:10.20944/preprints202306.0572.v1
Subject: Marine Engineering, Engineering Keywords: Marine Diesel Generator; reliability importance measures; fault identification; critical compo-nents; performance
Online: 8 June 2023 (03:21:11 CEST)
Redundancy in ship systems is provided to ensure operational resilience through equipment backups which ensures system availability and offline repairs of machinery. The electric power generation system of ships provides the most utility of all systems, hence is provided with good level of standby units to ensure reliable operations. Nonetheless, the occurrence of undesired black outs are common onboard ships and portends a serious danger to ship security and safety. Therefore, understanding the contributing factors affecting system reliability through component criticality analysis is essential to ensure a more robust maintenance and support platform for efficient ship operations. In this regard hybrid reliability and fault detection analysis were conducted to establish component criticality and related fault conditions. A case study was conducted on a ship power generation system consisting of 4 marine diesel power generation plants onboard an Offshore Patrol Vessel (OPV). Results from the reliability analysis indicate overall low system reliability of less than 70 per cent within the first 24 months of the 78 operational months. Component criticality using reliability importance measures was used to identify all components with more than 40 per cent contribution to sub systems failure. Additionally, machine learning was used to aid the reliability analysis through feature engineering and fault identification using Artificial Neural Networks classification. The ANN has identified failure patten threshold at about 200kva which can be attributed to overheating, hence establishing link between component failure and generator performance.
ARTICLE | doi:10.20944/preprints202305.1749.v1
Subject: Biology And Life Sciences, Virology Keywords: Marine sulfated glycans; SARS-CoV-2; Omicron XBB.1.5; Spike protein; Heparin
Online: 25 May 2023 (07:12:52 CEST)
Keywords: Marine sulfated glycans; SARS-CoV-2; Omicron XBB.1.5, Spike protein; Heparin
ARTICLE | doi:10.20944/preprints202305.1524.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Ascomycota; asexual fungi; marine fungi; multi-locus phylogeny; new taxa; taxonomy; ultrastructure
Online: 22 May 2023 (12:25:58 CEST)
The genus Amphichorda has been recently re-erected as an independent linage from Beauveria, circumscribed within Cordycipitaceae. However, its phylogenetic relationships with other members of this family remain obscure. In our on-going efforts to expand the knowledge on the diversity of culturable ascomycetes from the Mediterranean Sea, we isolated several specimens of Amphichorda. Preliminary sequence analyses revealed great phylogenetic distance with accepted Amphichorda species and a close relation to Onychophora coprophila. Onychophora is a monotypic genus of enteroblastic conidiogenous cells, presumably related to Acremonium (Bionectriaceae); while Amphichorda exhibits holoblastic conidiogenesis. Here, we examine representative strains of Amphichorda species to resolve the taxonomy of the genus and the above-mentioned fungi combining morphological, ultrastructure and multi-locus phylogenetic analyses (ITS, LSU, tef1, BenA). The results revealed Amphichorda as a member of the Bionectriaceae, where its asexual morphs represent a transition between enteroblastic and holoblastic conidiogenesis for this group of fungi. We also describe and illustrate Amphichorda littoralis sp. nov., and propose the new combination Amphichorda coprophila. In addition, we stablish key phenotypic features to distinguish Amphichorda species and demonstrate the higher salt tolerance degree of A. littoralis, consistent with its marine origin. This work provides a comprehensive framework for future studies in the genus.
ARTICLE | doi:10.20944/preprints202101.0187.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: paleoproterozoic; tsunami boulder deposit; marine transgression; Yilgarn Craton; Yerrida Basin; Windplain Group
Online: 11 January 2021 (12:24:16 CET)
Large blocks and boulders of banded iron formation and massive hematite up to 40 x 27 x 6 m and in excess of 10,000 metric tonnes were detached from outcrop of the Wilgie Mia Formation during the ca 2.20 Ga marine transgression at the base of the Paleoproterozoic Windplain Group, and deposited in a broad band on the wave-cut surface 900 to 1200 m to the east. At the same time sand and shingle was scoured from the sea floor, leaving remnants only on the western side of the Wilgie Mia Formation and on the eastern sides of the boulders. Evidence suggesting that the blocks were detached and transported and the sea floor scoured by a tsunami bore with a height of at least 40 m is provided by (1) the deposition of the blocks indicates transportation by a unidirectional sub-horizontal force, whereas the smaller boulders are randomly oriented (2) 900 -1200m separating the BIF outcrop and the blocks (3) the absence of the basal conglomerate between the blocks (4) the blocks and boulders rest directly on the wave-cut surface of deeply weathered amphibolites (5) the blocks and boulders are surrounded and overlain by fine-grained sandstone of the Windplain Group.
REVIEW | doi:10.20944/preprints202012.0757.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: Ocean front; Marine ecology; Fisheries; Front detection; Satellite imagery; Feature-based approach
Online: 30 December 2020 (14:53:37 CET)
This paper provides a concise review of remote sensing of ocean fronts and its applications in marine ecology and fisheries, with a particular focus on the most popular front detection algorithms/techniques: Canny (1986), Cayula and Cornillon (1990, 1992, 1995), Miller (2004, 2009), Shimada et al. (2005), Belkin and O’Reilly (2009), and Nieto et al. (2012). A case is made for feature-based approach in marine ecology and fisheries that emphasizes fronts as major structural and circulation features of the ocean realm that play key roles in various aspects of marine ecology.
ARTICLE | doi:10.20944/preprints202010.0636.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: intertidal mudflats; Nassariidae; new records; Gulf of Kachchh Marine Sanctuary; Gujarat; India
Online: 30 October 2020 (10:23:35 CET)
We report new findings of live specimens of Nassarius persicus (Martens, 1874) and N. tadjallii Moolenbeek, 2007, extending their range to the Gulf of Kachchh, Gujarat, India. The known distribution of both species was limited: N. persicus was distributed in the Persian Gulf, Gulf of Oman and Karachi, Pakistan; N. tadjallii was reported from the Persian Gulf and Gulf of Oman. We also provide comprehensive taxonomic descriptions of both species, along with additional morphological and ecological information.
ARTICLE | doi:10.20944/preprints202005.0312.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: marine invertebrates; glycosaminoglycans; platelets; circulating tumor cells; circulating tumor microemboli; hematogenic metastasis
Online: 19 May 2020 (07:45:44 CEST)
Although metastasis is the primary cause of death on patients with malignant solid tumors, efficient antimetastatic therapies are not clinically available thus far. Sulfated glycosaminoglycans from marine sources have shown promising pharmacological effects, acting in different steps of the metastatic process. Oversulfated dermatan sulfate from ascidians is effective in preventing metastasis by inhibition of P-selectin, a platelet surface protein involved in the platelet-tumor cell emboli formation. We report in this work that the heparan sulfate isolated from the viscera of the ascidian Phallusia nigra drastically attenuates metastasis of colon carcinoma cells in mice. Our in vitro and in vivo assessments demonstrate that the P. nigra glycan has very low anticoagulant and antithrombotic activities and a reduced hypotension potential, although efficiently preventing metastasis. Therefore, it may be a promising candidate for the development of a novel anti-metastatic drug.
ARTICLE | doi:10.20944/preprints202002.0139.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: restricticin; marine fungus; Penicillium janthinellum; BV-2 microglia cells; anti-inflammatory; rotamer
Online: 11 February 2020 (09:28:35 CET)
A new compound containing a triene, a tetrahydropyran ring and glycine ester functionalities, restricticin B (1), together with four known compounds (2-5) were obtained from the EtOAc extract of the marine fungus Penicillium janthinellum. The planar structure of 1 was determined by detailed analyses of MS, 1D and 2D NMR data. The relative and absolute configurations of 1 were established via analyses of NOESY spectroscopy data, comparison of optical rotation values with those of restricticin derivatives reported and electronic circular dichroism (ECD). All the compounds were screened for their anti-neuroinflammatory effects in lipopolysaccharide (LPS)-induced BV-2 microglia cells. Restricticin B (1) and N-acetyl restricticin (2) exhibited anti-neuroinflammatory effects by suppressing the production of pro-inflammatory mediators in activated microglial cells.
ARTICLE | doi:10.20944/preprints201912.0401.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: microbial eukaryotes; phylogeography; marine-freshwater transitions; evolutionary radiation; species flocks; Lake Baikal
Online: 31 December 2019 (03:57:14 CET)
Ancient lakes are among the most interesting models for evolution studies, because their biodiversity is the result of a complex combination of migration and speciation. Here, we investigate the origin of single celled planktonic eukaryotes from the oldest lake in the world – Lake Baikal. By using 18S rDNA metabarcoding we recovered 1,427 Operational Taxonomic Units (OTUs) belonging to protists populating surface waters (1-50 meters) and belonging to pico- and nano-plankton size fractions. The recovered communities resembled other lacustrine freshwater assemblages found elsewhere, especially the unclassified protists. However, our results suggest that a fraction of Baikal protists originated evolutionary recently from marine/brackish ancestors. Moreover, our results suggest that rapid radiation may have occurred among some protist taxa, partially mirroring what was already shown for multicellular organisms in Lake Baikal. We found potential species flocks in Stramenopiles, Alveolata, Opisthokonta, Archaeplastida, Rhizaria and Hacrobia. Putative flocks predominated in Chrysophytes, which are highly diverse in Lake Baikal. Some of the species, especially those from these flocks, may be endemic from Lake Baikal, because their 18S rDNA differed > 10% from known DNA. Overall, our study points to novel diversity of planktonic protists in Lake Baikal, some of which may have emerged in situ after evolutionary diversification.
ARTICLE | doi:10.20944/preprints201902.0023.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: anchovy; omega-3; limonene; circular economy; fish processing waste; marine fishery discards
Online: 3 February 2019 (02:58:23 CET)
Fish oil rich in polyunsaturated omega-3 fatty acids is extracted in high yield from anchovy filleting waste using d-limonene as green biosolvent in a simple solid-liquid extraction performed by mechanically stirring and maceration followed by limonene removal via evaporation under reduced pressure. As limonene is renewably obtained from waste orange peel, this protocol establishes a circular bioeconomy method to obtain valued omega-3 extracts from biowaste available worldwide in several million t/year amount. The method closes the materials cycle and opens the route to full valorisation of an important biological resource so far mostly discarded as waste. Significant economic opportunities benefiting local communities, the ecosystem and public health are anticipated.
ARTICLE | doi:10.20944/preprints202304.1160.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Cantharidin; Erythrocytes; Fish cell lines; Marine pathogen bacteria; Gilthead seabream (Sparus aurata); Aquaculture.
Online: 28 April 2023 (10:11:02 CEST)
Cantharidin, a toxic monoterpene secreted by blister beetles, has long been used in traditional Chinese and modern medicine for its unique properties. However, despite its widespread use, its effects on fish have not been studied in depth. The aim of this study was to evaluate the potential therapeutic applications of cantharidin in fish by examining its antioxidant, hemoagglutinating, hemolytic and cytotoxic activities at different concentrations (0, 0.625, 1.25, 2.5, 5 and 10 μg mL-1) in three different cell lines. In addition, the study explored the bactericidal and bacteriostatic properties of cantharidin against various fish pathogenic bacteria. The results revealed that there were no significant differences in antioxidant, hemagglutinating or hemolytic activities between the different concentrations of cantharidin tested. However, the study found that cantharidin exhibited dose- and time-dependent cytotoxicity in sea bream (Sparus aurata) erythrocytes and in SAF-1, PLHC-1 and Hela cell lines, resulting in morphological changes indicative of apoptosis. Interestingly, the highest dose of cantharidin tested demonstrated potent bactericidal activity against four marine fish opportunistic bacteria, including Vibrio harveyi, V. anguillarum, Photobacterium damselae and Tenacibaculum maritimum, but no statistically significant changes in bacteriostatic activity were observed against any of the bacteria tested. Overall, these results provide valuable information on the potential therapeutic applications of cantharidin in fish aquaculture. Further research is needed to fully understand the mechanisms of action and to explore possible preventive uses of cantharidin in fish.
ARTICLE | doi:10.20944/preprints202302.0109.v1
Subject: Engineering, Civil Engineering Keywords: Hydrodynamic model; Water quality model; Colombian Pacific coast; Marine pollution; Fecal col-iforms
Online: 7 February 2023 (02:35:39 CET)
The RMA11 water quality model, which has been previously calibrated and validated, was coupled with the RMA10 3D hydrodynamic model to evaluate sanitation scenarios in Buenaventura Bay. The bay receives direct discharge of untreated wastewater from 500,000 people through 695 outlets along the coast. Five different effluent reduction scenarios were proposed and compared based on fecal coliform concentration as an indicator. The areas where values exceed the standard for primary contact were also used to evaluate the scenarios. The model results indicate poor water quality in the bay and how that the situation will become even more severe if immediate action is not taken. The proposed reduction in discharges in stages will have temporarily more severe effects than the current situation, but these will end when the treatment plant becomes operational. However, even with the plant in operation, complete sanitation of the bay cannot be achieved, and further measures must be considered.
REVIEW | doi:10.20944/preprints202209.0320.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: marine natural products; oxygen heterocycles; tetrahydrofuran; total synthesis; biological activity; terpenes; fatty acids.
Online: 21 September 2022 (10:04:09 CEST)
heterocycles are particularly common moieties within marine natural products. Specifically, tetrahydrofuranyl rings are present in a variety of compounds which present complex structures and interesting biological activities. Focusing on terpenoids, a high number of tetrahydrofuran-containing metabolites have been isolated during the last decades. They show promising biological activities, making them potential leads for novel antibiotics, antikinetoplastid drugs, amoebicidal substances or anticancer drugs. Thus, they have attracted the attention of the synthetic community, and numerous approaches to their total syntheses have appeared. Here, we offer the reader an overview of marine-derived terpenoids and related compounds, with a special focus on their isolation, structure determination, biological profiles and total syntheses.
ARTICLE | doi:10.20944/preprints202105.0215.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Cymothoida; marine fish parasite; South China Sea; east coast Malaysia; crustacean fish parasite
Online: 10 May 2021 (15:32:00 CEST)
A checklist of parasitic cymothoids from Malaysian waters is presented based on available literature and material collected from 2010 to 2020. Most of the collected specimens were recorded from waters of Terengganu, east coast of Peninsular Malaysia (facing South China Sea), whereas literature records were represented from Sarawak, along the Miri coast of northwest Borneo. The checklist comprises 18 species under 10 genera, seven of which are new records from Malaysia, which includes Anilocra nemipteri Bruce, 1987; Ceratothoa barracuda Martin, Bruce and Nowak, 2015; Ceratothoa carinata (Bianconi, 1869); Cymothoa epimerica Avdeev, 1979; Elthusa sigani Bruce, 1990; Joryma engraulidis (Barnard, 1936) and Renocila richardsonae Williams and Bunkley-Williams, 1992. Eight new host records are based on collected specimens: Anilocra nemipteri was dorsally attached on Nemipterus nemurus (Bleeker 1857), Nemipterus nematophorus (Bleeker 1854), Nemipterus tambuloides (Bleeker 1853), and Nemipterus thosaporni Russell 1991 (family Nemipteridae); Ceratothoa carinata was found in the buccal cavity of Decapterus macrosoma Bleeker 1851 (family Carangidae); Cymothoa eremita (Brunnich, 1783) was attached in the buccal cavity of Nemipterus tambuloides and Nemipterus furcosus (Valenciennes 1830); Elthusa sigani was found attached on Pterois russelli Bennett 1831 (family Scorpaenidae); and Renocila richardsonae was attached on the caudal fin of Upeneus japonicus (Houttuyn 1782) (family Mullidae). All cymothoid species listed here are known to have a Central Indo Pacific distribution, with some ranging as far as the western Indian Ocean. The cymothoid-host association is here listed from 28 fish families, with the most common reported from Carangidae (pompanos, jack mackerels, runners, scads), Engraulidae (anchovies) and Leiognathidae (ponyfishes, slipmouths). This paper is the first comprehensive treatment to update both verified literature data and deposited specimens, with a key for the family Cymothoidae in Malaysian waters.
ARTICLE | doi:10.20944/preprints202010.0089.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Asparagopsis armata; Biodiversity; Intertidal assemblages; Invasive exotics; Marine invasion; Non-indigenous species (NIS)
Online: 5 October 2020 (13:28:46 CEST)
Biological invasions represent a threat to ecosystems, through competition and habitat destruction, which may result in significant changes of the invaded community. Asparagopsis armata is a red macroalgae (Rodophyta) globally recognized as an invasive species. It is found from the intertidal to shallow subtidal areas, on rock or epiphytic, forming natural vegetation belts on exposed coasts. This study evaluated the variations on native intertidal seaweed and macroinvertebrate assemblages inhabiting rock pools with and without the presence of the invasive macroalgae A. armata. To achieve this, manipulation experiments on Atlantic (Portugal) rock pools were done. Three rock pools were maintained without A. armata by manual removal of macroalgae, and three others were not experimentally manipulated during the study period and A. armata was freely present. In this study the variations between different rock pools were assessed. Results showed different patterns in the macroalgae composition of assemblages but not for the macrobenthic communities. Ellisolandia elongata was the main algal species affected by the invasion of A. armata. Invaded pools tended to show less species richness, showing a more constant and conservative structure, with lower variation of its taxonomic composition than the pools not containing A. armata, where the variability between samples was always higher. Despite the importance of the achieved results, further data based on observation of long-term series are needed, in order to further understand more severe effects of the invader A. armata on native macroalgal assemblage.
ARTICLE | doi:10.20944/preprints202002.0388.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Biosynthetic gene clusters; Eurotium rubrum; halophilic; marine genomics; nonribosomal peptide synthetase; T1pks; Terpene
Online: 26 February 2020 (10:58:18 CET)
Eurotium rubrum is a halophilic marine ascomycete, which can bear the hypersalinities of the Red Sea and proliferate, while most living entities cannot bear this condition. Recently, a 26.2 Mb assembled genome of this fungus had become available. Marine fungi are fascinating organisms capable of harboring several biosynthetic gene clusters (BGCs), which enables them to produce several natural compounds with antibiotic and anticancerous properties. Understanding the BGCs are critically important for the development of biotechnological applications and the discovery of future drugs. There is no knowledge available on the BGCs of this halophilic marine ascomycete. Herein, we set out to explore and characterize BGCs and the corresponding genes from E. rubrum using bioinformatic methods. We deciphered 36 BGCs in the genome of E. rubrum. These 36 BGCs can be grouped into four non-ribosomal peptide synthetase (NRPS) clusters, eight NRPS-like (NRPSL) BGCs, eight type I polyketide synthase (T1PKS), 11 terpene BGCs including one β-lactone cluster, four hybrid BGCs, and two siderophore BGCs. This study is an example of marine genomics application into potential future drug-like compound discovery.
REVIEW | doi:10.20944/preprints201806.0432.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bone tissue engineering; biomaterials; bone scaffolds; additive manufacturing techniques/robocasting; marine-derived biomaterials
Online: 26 June 2018 (16:05:49 CEST)
Bone is a dynamic tissue with the capacity of repair and regeneration in specific conditions. Nevertheless, due to the increased incidence of bone disorders, the need of bone grafts has been growing over the past decades and the development of an ideal bone graft with optimal properties remains a clinical challenge. This review addresses the bone properties (morphology, composition and their repair and regeneration capacity) and puts the main focus on the potential strategies for developing bone repair and regeneration materials. It describes the requirements for designing a suitable scaffold material, types of materials (polymers, ceramics and composites) and techniques to obtain the porous structures (additive manufacturing techniques/robocasting or derived from marine skeletons) for bone tissue engineering applications. The main objective of this review is to gather the knowledge on the materials and methods for the production of scaffolds for bone tissue engineering and highlighting the potential of natural porous structures such as marine skeletons as promising alternative bone graft substitute materials without any further mineralogical changes, or after partial or total transformation into calcium phosphate. The suitability of the marine-derived porous bone graft substitutes for the intended applications will be also discussed.
ARTICLE | doi:10.20944/preprints201805.0222.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: terepinic acids; Stereum sp.; marine microorganism; Undaria pinnatifida; vibralactones; phenylglycine methyl ester method
Online: 16 May 2018 (06:28:36 CEST)
Sterepinic acids A–C (1–3), new carboxylic acids with two primary alcohols, have been isolated from a fungal strain of Stereum sp. OUPS-124D-1 attached to the marine alga Undaria pinnatifida. Dihydro-1,5-secovibralactone (4), a new vibralactone derivative, was isolated from the same fungal metabolites together with known vibralactone A (5), and 1,5-secovibralactone (6). The planar structures of these compounds have been elucidated by spectroscopic analyses using IR, HRFABMS, and NMR spectra. To determine the absolute configuration of the compounds, we used the phenylglycine methyl ester (PGME) method. These compounds exhibited less activity in the cytotoxicity assay against cancer cell lines.
ARTICLE | doi:10.20944/preprints201804.0048.v1
Subject: Engineering, Marine Engineering Keywords: marine current turbines; hydrodynamics; boundary element methods; trailing wake models; viscous flow correction
Online: 4 April 2018 (06:03:25 CEST)
A computational methodology for the hydrodynamic analysis of horizontal axis marine current turbines is presented. The approach is based on a boundary integral equation method for inviscid flows originally developed for marine propellers and adapted here to describe the flow features that characterize hydrokinetic turbines. To this purpose, semi-analytical trailing wake and viscous-flow correction models are introduced. A validation study is performed by comparing hydrodynamic performance predictions with two experimental test cases and with results from other numerical models in the literature. The capability of the proposed methodology to correctly describe turbine thrust and power over a wide range of operating conditions is discussed. Viscosity effects associated to blade flow separation and stall are taken into account and predicted thrust and power are comparable with results of blade element methods that are largely used in the design of marine current turbines. The accuracy of numerical predictions tend to reduce in cases where turbine blades operate in off-design conditions.
ARTICLE | doi:10.20944/preprints202305.2259.v1
Subject: Engineering, Energy And Fuel Technology Keywords: Marine Vessels; Nuclear-Renewable Hybrid Energy Systems; Waterfront Applications, Seaports, Hydrogen Production, Energy Efficiency.
Online: 31 May 2023 (14:02:36 CEST)
The global trade and transportation sectors heavily rely on the maritime industry. Still, its dependence on fossil energy sources poses significant environmental challenges and leads to unstable fuel prices that affect the cost of goods transported by sea. This paper aims to evaluate the viability of seaports as energy-intensive entities and explore the feasibility of implementing a Nuclear-Renewable Hybrid Energy System (NRHES). The study presents a case study of the Tanjung Priok Port in Indonesia, focusing on estimating energy consumption, emissions, and the potential impact of carbon taxation on seaport operations. By quantifying these factors, the research provides insights into the energy requirements, environmental effects, and potential costs associated with seaport carbon taxation. A comprehensive analysis of the technical and economic feasibility of implementing an NRHES in the seaport case study is conducted, determining the optimal sizing and composition of components, considering the proportion of nuclear and renewable energy sources. Additionally, the economic analysis considers energy costs, net present cost, cash flow, return on investment, and internal rate of return. The findings aim to inform decision-makers about the benefits and challenges of adopting an NRHES, contributing to a cleaner and more sustainable future for the maritime industry.
ARTICLE | doi:10.20944/preprints202211.0432.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: sustainable food production; pH; supplemental C; marine aquaponics; wastewater treatment; halophytic plants; Litopenaeus vannamei
Online: 23 November 2022 (04:17:35 CET)
pH is the major factor that makes producers in aquaponics frustrated, since the main three organisms (aquatic animal, plant, and microbes) in the system with different preferences. Yet, amending the growing environment with additional C is a potential method to improve the growth of shrimp and plants as well as the establishment of microbe. A detailed study of the effects of pH and additional C on aquaponics under saline conditions has not been investigated. In this study, the effect of pH and additional C on the growth performance of shrimp (Litopenaeus vannamei) and five edible plants in marine aquaponic systems using the nutrient film technique (NFT) was evaluated. The results indicated that at both pH 6.5 treatments, plants grew better; nevertheless, the growth performance of plants in pH 7.5 with additional C was improved and showed a similar yield to lower pH treatments. On the other hand, shrimp growth was little affected by pH and additional C. A higher impact of imbalanced ionic composition on shrimp performance may have contributed to this trend. Hence, we suggest that only if the ionic composition is managed can make RO water a suitable source of water for shrimp-based aquaponic. In spite of this, more research is required.
ARTICLE | doi:10.20944/preprints202104.0094.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: West Africa ; Atlantic humpback dolphin ; bottlenose dolphin ; bycatch ; marine bushmeat ; aquatic wild meat ; conservation
Online: 5 April 2021 (10:38:32 CEST)
Small-boat and shore-based surveys in 2017 confirm that Atlantic humpback (Sousa teuszii) and common bottlenose dolphins (Tursiops truncatus) are resident in shallow neritic waters surrounding the protected MPA Tristao Islands in northern Guinea. Inshore-type T. truncatus were encountered also between Conakry and Kayar. First documented in 2012, dolphin bycatches in local fisheries continue to occur. The frequency of beach-cast remains suggests a significant conservation issue. Both multi- and monofilament gillnets are widely deployed, but it remains unclear which gear is the main cause of mortality. Forensic evidence shows that captured dolphins are often utilized for local consumption. Marine bushmeat of cetaceans is documented in many coastal nations in West and Central Africa. In Tristao Islands their use is synchronous with and thought related to declining fish stocks. Significant anthropogenic mortality relative to their low abundance, besides suspected pressures such as prey competition with fisheries and habitat deterioration from coastal development, raise concern for the future of coastal dolphins, in particular endangered S. teuszii, even in this formally protected MPA. Conservation measures need to be re-evaluated for improved efficiency while surveys to monitor trends should be annual.
ARTICLE | doi:10.20944/preprints202011.0514.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: In-Stream Tidal Energy Resources; Macro-Tidal Environments; Marine Renewable Energy; Gulf of California
Online: 19 November 2020 (14:18:31 CET)
While many in-steam tidal energy resource studies have been carried out globally, very few studies have assessed the effect of seabed changes on tidal energy resources. For coastal regions in particular, where the seabed is generally more mobile than in deep waters, bathymetric evolution could have a significant effect on tidal energy production. Here two high-resolution models, one purely hydrodynamic and one morphodynamic, are used to analyse the potential effect of natural morphodynamic evolution on tidal energy resources at two macro-tidal sandy bays, Adaír Bay and San Jorge Bay, in the Upper Gulf of California, Mexico. The high-resolution models are validated using a low-resolution model and ADCP observations to assess the agreement between model predictions and observations of tides at three ADCP moorings within the domain of interest. The models’ skill is evaluated using several error statistics such as the mean relative error, the root mean square error (RMSE), and the correlation coefficient. It was found that the regions with the largest bed changes, and also the largest renewable energy resources, were near the shore. Moreover, the results indicated a good correlation between a) regions with the most significant depth changes, and b) the regions where the difference in annual energy production with and without depth change was largest. Finally, the morphodynamic model was run for two years, and the evolution of a zonal profile (in the west-east direction) off the coast at the southeastern corner of Adaír Bay was inspected. This profile evolved towards a featureless equilibrium profile, in good agreement with the morphological classification for macro-tidal sandy environments and with the model assumptions. But most importantly, this natural evolution would not be detrimental to tidal energy exploitation at the site.
ARTICLE | doi:10.20944/preprints202002.0237.v1
Subject: Engineering, Marine Engineering Keywords: Colombia; Colombian Caribbean; marine climate; Mallorquín Lagoon; Puerto Colombia; Wave Watch III; wave; wind
Online: 17 February 2020 (03:32:48 CET)
This work presents an application called APPMAR 1.0 based on Python ® environment, built to perform the downloading, treatment and analysis of meteorological and marine information. This application is composed of two main modules: the first module allows the downloading of information from the database (NOAA - WW3); the second module uses the principles of statistical mathematics for the treatment of waves and wind. The importance of this simple application is based on the free and agile access to meteorological and marine information for a coastal project. The determination of representative conditions of sea states ultimately will govern the process of design of coastal and oceanic infrastructure. The analysis of historical time series of local waves and winds allows the evaluation of average regimes or operational design, the ultimate limit states or extreme design, and the storms or design by persistence. In spite that the former analysis is a common task for coastal engineers, the codes generated are seldom shared for public use. In summary, for operational purposes is useful to have a freeware that can assist in the data processing for decision making and forcing of the mathematical models that are part of the common practice of coastal, oceanic and offshore engineering. This application has been tested in the Caribbean area of Colombia where meteorological and marine information are scarce.
ARTICLE | doi:10.20944/preprints201906.0186.v1
Subject: Environmental And Earth Sciences, Geophysics And Geology Keywords: tephra in marine sediments; Ash Zone I in North Atlantic; tephrochronology of Termination I
Online: 19 June 2019 (15:38:40 CEST)
Based on the geochemical analysis of the volcanic material from the sediment core AMK-340, central zone of the Reykjanes Ridge, we could detect two ash-bearing sediment units accumulated during the Termination I. They correlate to the Ash Zone I in the North Atlantic Late Quaternary sediments having an age of 12170-12840, within the Younger Dryas cold chronozone, and 13600-14540 years, within and Bølling-Allerød warm chronozone. The ash of the Younger Dryas unit is presented mostly by the mafic and persilicic material originated from the Icelandic volcanoes; Vedde Ash is presented in one sediment sample from this unit. The ash of the Bølling-Allerød unit is presented mostly by the mafic shards which are related to the basalts of the rift zone on the Reykjanes Ridge, having presumably the local origin. A detection of Vedde Ash helped to specify the timing of the previously reconstructed paleoceanographic changes for the Termination I in the point of study: a significant warming in the area could occur as early as 300 years prior to the end of the conventional Younger Dryas cold chronozone.
ARTICLE | doi:10.20944/preprints201904.0147.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: Zn-Al-Mg-TiO2 coating; Zn-Al coating; marine anticorrosion; corrosion; friction and wear
Online: 12 April 2019 (10:50:38 CEST)
According to research, we have learned that Mg and TiO2 are new types material of marine protective coatings. We found that the addition of Mg can improve the performance of Zn-Al coating passivation film, and TiO2 has excellent photocatalytic self-cleaning performance. In this paper Zn-Al pseudo alloy coating was prepared by cold spray technique, and Zn-Al-Mg-TiO2 pseudo alloy composite coating was prepared by adding Mg and nano-TiO2. The effects of Mg and TiO2 to the marine protective properties of Zn-Al coatings were studied by friction and wear test, dynamic salt water corrosion test, electrochemical test, scanning electron microscope(SEM), energy dispersive spectrometer(EDS) and super deep scene 3D microscope. The results show that the addition of Mg and nano-TiO2 not only fills the gap of the coating and improves the density of the coating, but also generates grid-like flocculent corrosion products on the surface of the coating which can gather other corrosion products to improve the density of corrosion products, reduce the friction coefficient and corrosion rate of the coating surface, effectively prevent the invasion of Cl- in solution, and improve the wear and corrosion resistance of the coating.
ARTICLE | doi:10.20944/preprints201810.0326.v1
Subject: Computer Science And Mathematics, Data Structures, Algorithms And Complexity Keywords: clustering-based optimization; location optimization; flood-filling algorithm; marine accident; rescue ship; shortest distance
Online: 15 October 2018 (16:53:32 CEST)
Currently, maritime traffic is increasing with economic growth in several regions worldwide. However, this growth in maritime traffic has led to increased risk of marine accidents. These accidents have a higher probability of occurring in regions where geographical features, such as islands, are present. Further, the positioning of rescue ships in a particular ocean region with a high level of maritime activity is critical for rescue operations. This paper proposes a method for determining an optimal set of locations for stationing rescue ships in an ocean region with numerous accident sites in the Wando islands of South Korea. The computational challenge in this problem is identified as the positioning of numerous islands of varying sizes located in the region. Thus, the proposed method combines a clustering-based optimization method and an image processing approach that incorporates flood filling to calculate the shortest distance between two points in the ocean that detours around the islands. Experimental results indicate that the proposed method reduces the distance from rescue ships and each accident site by 5.0 km compared to the original rescue ship locations. Thus, rescue time is reduced.
ARTICLE | doi:10.20944/preprints202305.0166.v1
Subject: Environmental And Earth Sciences, Water Science And Technology Keywords: nutrient release rate; marine sediment; redeposition; incubation experiment; Osaka Bay; Nankai Trough earthquake; primary production
Online: 4 May 2023 (03:02:10 CEST)
Nutrient release from marine sediments in Osaka Bay has a significant impact on nutrient concentrations in seawater. A tsunami induced by the Nankai Trough earthquake may disturb marine sediments in the inner part of Osaka Bay. An incubation experiment to estimate the release rates of NH4-N and PO4-P was conducted to understand the present conditions and to quantify the changes caused by tsunamis. Two types of cores were created: a "control core" representing the current sediment, and a "redeposition core" representing the redeposition after the tsunami. The release rates have been decreasing since the year 2000 and have remained low. The experimental results suggest that the release rate after exposure to an aerobic environment by a tsunami may decrease to approximately 70% for NH4-N and 60% for PO4-P of the current level. In the past, the release rates were values experienced in the inner part of Osaka Bay. However, the reduction in the release rate by tsunamis may be more limiting for primary production under the current situation where the contribution of release for nutrients in seawater is significant.
ARTICLE | doi:10.20944/preprints202106.0614.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: marine weather; characteristic wave height; storm surge; shore platform; overtopping wave; hydrodynamics equation; flooding hazard
Online: 25 June 2021 (10:12:06 CEST)
Boulder dynamics may provide essential data for the coastal evolution and hazards assessment and can be focused as a proxy for the onshore effect of intense storm waves. In this work, detailed observations of currently available satellite imagery of the Earth surface allowed to identify several coastal boulders displacements in the Southern Apulia coast (Italy), in a period between July 2018 and June 2020. Field surveys confirmed the displacements of several dozens of boulders up to several meters in size, also allowing the determination of the initial position for many of them. Archive weather analyses identified two possible causative storms during the same period, and calculations based on analytical equations are found in agreement with the displacement by storm waves for most of the observed boulders. The results help to give insights about the onshore effect of high storm waves on the coastal hydrodynamics and the possible future flooding hazard in the studied coast.
ARTICLE | doi:10.20944/preprints202011.0685.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: teleost fish; Notothenioidei; genome modifications; IgT; exonic remnant; immunoglobulin domain; Antarctic marine environment; molecular evolution
Online: 27 November 2020 (11:31:09 CET)
Cryonotothenioidea is the main group of fishes that thrive in the extremely cold Antarctic environment, thanks to the acquisition of peculiar morphological, physiological and molecular adaptations. We have previously disclosed that IgM, the main immunoglobulin isotype in teleosts, display typical cold-adapted features. Recently, we have analyzed the gene encoding the heavy chain constant region (CH) of the IgT isotype from the Antarctic teleost Trematomus bernacchii (family Nototheniidae), characterized by the near-complete deletion of the CH2 domain. Here, we aimed to track the loss of the CH2 domain along notothenioid phylogeny and to identify its ancestral origins. To this end, we obtained the IgT gene sequences from several species belonging to the Antarctic families Nototheniidae, Bathydraconidae and Artedidraconidae. All species display a CH2 remnant of variable size, encoded by a short Cτ2 exon, which retains functional splicing sites and therefore is included in the mature transcript. We also considered representative species from the three non-Antarctic families: Eleginopsioidea (Eleginops maclovinus), Pseudaphritioidea (Pseudaphritis urvillii) and Bovichtidae (Bovichtus diacanthus and Cottoperca gobio). Even though only E. maclovinus, the sister taxa of Cryonotothenioidea, shared the partial loss of Cτ2, the other non-Antarctic notothenioid species displayed early molecular signatures of this event. These results shed light on the evolutionary path that underlies the origins of this remarkable gene structural modification.
SHORT NOTE | doi:10.20944/preprints202005.0287.v1
Subject: Biology And Life Sciences, Aquatic Science Keywords: COVID-19; small scale fisheries; artisarnal fishers; coastal communities; marine protected area; Malaysia; fisheries; impacts
Online: 17 May 2020 (08:46:10 CEST)
As early as February 2020, many countries have started imposing measures to curb the spread of Covid-19. Despite the right intention, it is a challenging moment for the people, especially the rural population living in the coastal areas. The document presents the preliminary findings on the impacts of Covid-19 on the small scale fisheries in Tun Mustapha Park, Sabah, Malaysia.