ARTICLE | doi:10.20944/preprints202212.0123.v2
Online: 9 December 2022 (10:10:08 CET)
(1) Background: This study aims to validate the use of Bloom's revised taxonomy as an instrument for the design of assessment tests; (2) Methods: A validation has been carried out by external judges, as well as by teachers and students, validating the instrument by means of Aiken's V; (3) Results: Judges, teachers and students consider Bloom's revised taxonomy as an effective tool for the design of assessment tests; (4) Conclusions: Using Bloom's revised taxonomy as a model for designing assessment tests promotes learning.
ARTICLE | doi:10.20944/preprints202212.0464.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: satellite monitoring; spectral shape algorithm; Karenia bloom evolution; harmful algal bloom
Online: 26 December 2022 (02:55:48 CET)
The environmental disaster in Kamchatka in the autumn of 2020 was caused by an extensive bloom of harmful microalgae of the genus Karenia. A spectral shape algorithm was used to detect algae. The algorithm calibration of in situ species composition data made it possible to identify areas where harmful algae dominated in biomass. Satellite images of chlorophyll-a concentra-tion, turbidity, specific fluorescence, and spectral shape parameter were computed. The images were used to recognize the stages of algal bloom: intensive growth, blooming, and change in the dominant algal species. Cases of an increase in the concentration of harmful substances in the coastal zone due to wind impact were analyzed. The following explanation of events has been offered. After the stage of intensive growth of microalgae, nutrient deficiency stimulated the production of metabolites that have a harmful effect on the environment. The change of the dominant alga species in the second half of September and the past storm contributed to a sharp increase in the concentration of metabolites and dead organic matter in the coastal zone, which caused an ecological disaster. The subsequent mass bloom of alga species of the same genus, and the regular wind impact leading to the concentration of harmful substances in the coastal zone, contributed to the development of this catastrophic phenomena.
ARTICLE | doi:10.20944/preprints201709.0033.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: P. rubescens algal bloom; remote sensing; MERIS; MODIS
Online: 10 September 2017 (07:36:21 CEST)
In winter 2008-2009, Lake Occhito, a strategic multiple-uses reservoir in South Italy, was affected by an extraordinary Planktothrix rubescens bloom. P. rubescens is a filamentous potentially toxic cyanobacterium which has recently colonized many environments in Europe. A number of studies is currently available on the use of remote sensing techniques to monitor different fresh water cyanobacteria species. By contrast no specific applications are available on the remote sensing monitoring of P. rubescens. In this paper we present a specific algorithm, based on Water Leaving Reflectances (WLR) from MERIS data, atmospherically corrected using the Aerosol Optical Thickness (AOT) retrieved by MODIS data, to detect P. rubescens blooms. The high accuracy in AOT data, provided by MOD09 surface reflectance product, at 1km spatial resolution, allowed obtaining a good correlation between the WLR and the P. rubescens chlorophyll-a concentrations measured in the field, through multiple stations fluorometric profiles. A modified Normalized Difference Chlorophyll index (NDCI) algorithm is presented. The performance of the proposed algorithm has been successfully compared with other specific algorithms for turbid productive waters. We demonstrated how important is to verify the spectral behaviour of bio-optical parameters in order to develop an ad hoc algorithm that better performs with respect to standard algorithms.
ARTICLE | doi:10.20944/preprints202209.0456.v1
Subject: Biology And Life Sciences, Virology Keywords: Marnaviridae; algal bloom; algal viruses; icosahedral viruses; ssRNA viruses
Online: 29 September 2022 (07:53:23 CEST)
Marnaviridae viruses are abundant algal viruses that regulate the dynamics of algal blooms in aquatic environments. They employ a narrow host range because they merely lyse their own algal host species. This host-specific lysis is thought to correspond to the unique transmission mechanism of the Marnaviridae viruses. Here, we present the atomic structures of the full and empty capsids of Chaetoceros socialis forma radians RNA virus 1 built in 3.0 Å and 3.1 Å cryo-electron microscopy maps. The empty capsid structure and the structural variability provide insights on its assembly and uncoating intermediates. In conjunction with the previously reported atomic model of the Chaetoceros tenuissimus RNA virus type II capsid, we have identified the common and diverse structural features of the VP1 surface between the Marnaviridae viruses. We have also tested the potential usage of AlphaFold2 for structural prediction of the VP1s and a subsequent structural phylogeny for classifying Marnaviridae viruses by their hosts. These findings will be crucial for inferring the host-specific transmission mechanism in Marnaviridae viruses, which is decisive for monitoring and possibly regulating the occurrence and disappearance of algae blooms.
ARTICLE | doi:10.20944/preprints202008.0598.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: physical unclonable function; bloom filter; hardware security; PUF; memristor
Online: 27 August 2020 (08:05:03 CEST)
Because the development of the internet of things (IoT) requires technology that transfers information between objects without human intervention, the core of IoT security will be secure authentication between devices or between devices and servers. Software-based authentication may be a security vulnerability in IoT, but hardware-based security technology can provide a strong security environment. A physical unclonable functions (PUFs) are a hardware security element suitable for lightweight applications. PUFs can generate challenge-response pairs(CRPs) that cannot be controlled or predicted by utilizing inherent physical variations that occur in the manufacturing process. In particular, pulse width memristive PUF (PWM-PUF) improves security performance by applying different write pulse widths and bank structures. Bloom filter (BF) is probabilistic data structures that answer membership queries using small memories. Bloom filter can improve search performance and reduce memory usage and are used in areas such as networking, security, big data, and IoT. In this paper, we propose a structure that applies Bloom filters based on the PWM-PUF to reduce PUF data transmission errors. The proposed structure uses two different Bloom filter types that store different information and that are located in front of and behind the PWM-PUF, improving security by removing challenges from attacker access. Simulation results show that the proposed structure decreases the data transmission error rate and reuse rate as the Bloom filter size increases, the simulation results also show that the proposed structure improves PWM-PUF security with a very small Bloom filter memory.
COMMUNICATION | doi:10.20944/preprints202307.1676.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Arctic Oscillation Index; bloom; climate change; health risk; Portuguese man-of-war
Online: 25 July 2023 (09:00:30 CEST)
Historically, Physalis physalis massive stranding events have been infrequent and poorly documented. However, their occurrence can have significant impacts on human health and the stability of coastal ecosystems. In this study we analyze the largest P. physalis stranding event historically recorded affected Cuba’s northwestern coast in December 2022. We counted all colonies during the massive event along ~ 3 km coast, within a 5 m stripe. Density, dimorphic form (left/right-handed), and colony size were quantified using 0.25 m2 quadrat placed every 50 m, 10 m from shoreline. Eighty-five people were stung, with 38 having strong allergic reactions, resulting in a health risk. Over ten thousand colonies were recorded, with the highest mean colony density (29.3 per m2) ever reported. The massive stranding coincided with the lowest Arctic Oscillation index (-2.59) in the past 11 years during December, likely linked to climate change. This led to the emergence of northeasterly winds reaching speeds of up to 24 km/h. Wind direction and speed, coupled with the dominance of left-handed colonies (71.4%), suggest the Sargasso Sea as the possible source of the bloom. The high prevalence of juvenile P. physalis colonies (68 %) likely aligns with the autumn breeding season in the northern hemisphere. The potential causes of P. physalis blooms are still poorly understood. Systematic monitoring of the distribution and abundance of this species should be a research priority considering the potential risk to human health and that the blooms could become more frequent and affect other areas in the Atlantic, given climate change and increasing eutrophication of the oceans.
ARTICLE | doi:10.20944/preprints202306.0445.v1
Subject: Physical Sciences, Applied Physics Keywords: Bell-and-Bloom; atomic magnetometer; Dynamic response; Time-dependent field; Larmor precession
Online: 6 June 2023 (11:26:16 CEST)
The dynamic response of a Bell-and-Bloom magnetometer to a parallel (to the bias field) time-dependent field is modelled beyond the commonly assumed quasi-static regime. The results unveil features that are related to the parametric nature of the considered system. It is shown that a for low-amplitude time-dependent field different operating conditions are possible and that, beside the commonly reported low-pass-filter behaviour, a band-pass response emerges. Moreover, we numerically show that for larger field amplitude the system, due to its parametric nature, has a kind of ``non-linear'' response.
ARTICLE | doi:10.20944/preprints202307.0672.v1
Subject: Biology And Life Sciences, Horticulture Keywords: Dilwet, full bloom, red and white grapes, Spain, France, Germany, Egypt, Italy, Portugal
Online: 25 July 2023 (13:47:33 CEST)
Combinations of Dilwet, an organosilicone surfactant, and ethephon, a hormonal compound often applied to fruit trees to thin the crop, were applied at full bloom to prevent fruit development in two young vineyards differing in elevation by 600 m. Each vineyard was planted with the same 19 red and 10 white grape cultivars from a range of countries of origin. Vineyard elevation did not affect response to treatment. A combined spray of 0.5% Dilwet with 0.04% ethephon reduced cluster number by an average of 85%, while weight of the remaining clusters was reduced by 63%, compared to unsprayed controls. Increasing the concentration of Dilwet to 1% reduced cluster number by 93% and cluster weight by 76%. There were significant differences in the response of cultivars to the treatments, depending on country of origin, with grapes originating in France responding better to higher concentrations of Dilwet. White grapes were more responsive than red grapes. These results highlight the need to test different cultivars and genetic origins of crops when examining the effects of new agricultural chemicals.
REVIEW | doi:10.20944/preprints201903.0231.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: cyanotoxin; cyanobacterial bloom; cylindrospermopsin; microcystin; inflammation; diarrhea; gastrointestinal illness; lipopolysaccharide; innate immune system
Online: 26 March 2019 (09:31:44 CET)
Cyanobacterial blooms occur with increasing frequency in freshwater ecosystems, posing a hazard to human and environmental health. Exposure of human to cyanobacterial metabolites occurs mostly via accidental ingestion through contaminated drinking water or during recreational activities and, most frequently, results in gastrointestinal symptoms. Despite the clinical manifestation, cyanobacterial metabolites are rather investigated for their toxicity towards specific organs or tissues, especially hepato-, nephro- and neurotoxicity, then for effects on the gastrointestinal tract and the associated lymphoid tissue. The aim of this review was to systematically summarize available literature on the effects on the gastrointestinal tract and the mucosal innate immune system and compile the data from both, in vitro and in vivo studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies. studies, focusing on human-health relevant models. Our systematic literature review revealed significant data gaps in the understanding on metabolites breaching the gastrointestinal barrier and the role of the immune system in the establishment of clinical symptoms. Microcystins and cylindrospermopsin were linked to gastrointestinal symptoms, immune system effects or both. Furthermore, implications for cyanobacterial bloom lipopolysaccharides in gastrointestinal inflammation were reported in several cases, while other metabolites received only minor attention. The collected data indicate the need for a reassessment of potential enterotoxicity of microcystins and cylindrospermopsin. Additionally, the carcinogenic potential of cyanotoxins, especially microcystins, has to be clarified, as an increasing amount of epidemiological studies show correlations between cyanobacterial blooms and gastrointestinal cancer incidence. Furthermore, other, often highly abundant bioactive metabolites like aeruginosins, have to be toxicologically evaluated at levels also accounting for (sub-)chronic exposure to low concentrations and in combination with naturally co-occurring metabolites, as can be expected in drinking water supplies.
Subject: Engineering, Automotive Engineering Keywords: aerial vehicle; algal bloom index; autonomous; chlorophyll-a mapping; GNDVI; NDVI; surface vehicle; unmanned
Online: 19 January 2021 (09:14:00 CET)
The current study investigated the use of two-dimensional spatial distribution mapping representing the chlorophyll-a level in a river generated via an unmanned aerial vehicle (UAV) and an unmanned surface vehicle (USV). A domestically developed UAV (Remo-M, Uconsystem Inc., Korea) and a USV developed by our research team were used to collect data from the Nae Seong stream in Korea. An adaptation of the “Data Cleaner” tool was developed and used for USV data processing and analysis. The operation of the autonomous USV was successful. Four previously described indices for quantifying algal blooms in rivers were utilized to create chlorophyll-a images, the normalized difference vegetation index (NDVI), the normalized green red difference index, the green normalized difference vegetation index (GNDVI), and the normalized difference red edge index. The suitability of the linear regression analysis of the correlation between the spectral indices obtained using the UAV and the in situ chlorophyll-a data obtained using the USV was evaluated with the coefficient of determination (R2) at a significance level of p < 0.001. In field application and correlational analysis the NDVI was strongly correlated with chlorophyll-a (R2 = 0.88, p < 0.001), and the GNDVI was moderately correlated with chlorophyll-a (R2 = 0.74, p < 0.001). The map of chlorophyll-a was successfully quantified using the UAV and USV hybrid platforms.
ARTICLE | doi:10.20944/preprints201809.0038.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: Karenia brevis, harmful algal bloom (HAB), moderate resolution imaging Spectroradiometer (MODIS), prediction, chlorophyll, multivariate regression
Online: 3 September 2018 (13:52:41 CEST)
Over the past two decades, persistent occurrences of harmful algal blooms (HAB; Karenia brevis) have been reported in Charlotte County, southwestern Florida. We developed data-driven models that rely on spatiotemporal remote sensing and field data to identify factors controlling HAB propagation, provide a same-day distribution (nowcasting), and forecast their occurrences up to three days in advance. We constructed multivariate regression models using historical HAB occurrences (213 events reported from January 2010 to October 2017) compiled by the Florida Fish and Wildlife Conservation Commission and validated the models against a subset (20%) of the reported historical events. The models were designed to specifically capture the onset of the HABs instead of those that developed days earlier and continued thereafter. A prototype of an early warning system was developed through a threefold exercise. The first step involved the automatic downloading and processing of daily Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua products using SeaDAS ocean color processing software to extract temporal and spatial variations of remote sensing-based variables over the study area. The second step involved the development of a multivariate regression model for same-day mapping of HABs and similar subsequent models for forecasting HAB occurrences one, two, and three days in advance. Eleven remote sensing variables and two non-remote sensing variables were used as inputs for the generated models. In the third and final step, model outputs (same-day and forecasted distribution of HABs) were posted automatically on a web-based GIS (http://www.esrs.wmich.edu/webmap/bloom/). Our findings include the following: (1) the variables most indicative of the timing of bloom propagation are bathymetry, euphotic depth, wind direction, SST, chlorophyll-a [OC3M] and distance from the river mouth, and (2) the model predictions were 90% successful for same-day mapping and 65%, 72% and 71% for the one-, two- and three-day advance predictions, respectively. The adopted methodologies are reliable, dependent on readily available remote sensing data sets, and cost-effective and thus could potentially be used to map and forecast algal bloom occurrences in data-scarce regions.
TECHNICAL NOTE | doi:10.20944/preprints202211.0220.v2
Subject: Computer Science And Mathematics, Information Systems Keywords: Relational Database; Columnar Storage; Bloom Filter; Skip List; Field Level Lock; Read Write Concurrency; OLTP; OLAP; LSM-Tree; Token Bucket Algorithm
Online: 14 November 2022 (03:02:09 CET)
At present, diversified and highly concurrent businesses in the Internet industry often require heterogeneous databases formed by multiple databases to meet the needs. This report introduces database kernel SG-ColBase we developed. After achieving read and write concurrency control, data rollback, atomic log writing, and downtime data redo to ensure complete transaction support. The parallelism of database kernel execution is extended through field level locks and snapshot reads. Use the Bloom filter, resource cache pool, memory pool, skip list, non blocking log cache, and asynchronous data writing mechanism to improve the overall execution efficiency of the system. In terms of data storage, column storage, logical key and LSM-tree are introduced. While improving the data compression ratio and reducing data gaps, all disk data operations are written in incremental order. With the characteristics of asynchronous batch operation, the data writing speed is greatly improved. Thanks to the continuous feature of vertical data brought by column storage, the disk scanning brought by vertical traversal is reduced, which is a qualitative leap in efficiency compared with traditional relational databases in the big data analysis scenario. SG-ColBase can reduce the use of heterogeneous databases in business and improve R&D efficiency.
ARTICLE | doi:10.20944/preprints202008.0282.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: cyanobacteria; cyanopeptides; eutrophication; harmful bloom; liquid chromatography tandem mass spectrometry; Global Natural Product Social networking (GNPS); Dereplication strategy.
Online: 12 August 2020 (10:15:46 CEST)
Man-made shallow fishponds in the Czech Republic have been facing a high eutrophication since 1950s. Anthropogenic eutrophication and feeding of fish have strongly affected the physico-chemical properties of water and its aquatic community composition leading to harmful algal bloom formation. In our current study, we have characterised the phytoplankton community across three hypertrophic ponds to assess the phytoplankton dynamics during the vegetation season. We microscopically identified and quantified 29 cyanobacterial taxa comprised of non-toxigenic and toxigenic species. Further, a detailed cyanopeptides (CNPs) profiling was performed using molecular networking analysis of liquid chromatography tandem mass spectrometry (LC–MS/MS) data coupled with dereplication strategy. This MS networking approach coupled with dereplication on online global natural product social networking (GNPS) web platform led us to putatively identify forty CNPs: fourteen anabaenopeptins, ten microcystins, five cyanopeptolins, six microginins, two cyanobactins, a dipeptide radiosumin, a cyclooctapeptide planktocyclin and epidolastatin12. We have applied the binary logistic regression to estimate the CNPs producer by correlating the GNPS data with the species abundance. Usage of The combination of molecular networking and dereplication on online global natural product social networking (GNPS) web platform has proved as a valuable approach for rapid and simultaneous detection of high number of peptides, and rapidly assessing the risk for harmful bloom.
REVIEW | doi:10.20944/preprints202301.0357.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: cyanotoxins; cyanobacteria; harmful algae bloom; neurodegenerative disease; microcystin; BMAA; non-proteogenic amino acids; mistranslation; amyotrophic lateral sclerosis; Alzheimer’s disease
Online: 19 January 2023 (11:46:59 CET)
Cyanobacteria produce a wide range of structurally diverse cyanotoxins and bioactive cyanopeptides in freshwater, marine, and terrestrial ecosystems. The health significance of these metabolites, which include genotoxic- and neurotoxic agents, is confirmed by continued associations between the occurrence of animal and human acute toxic events and, in the long term, by associations between cyanobacteria and neurodegenerative diseases. One of the implicated mechanisms includes a misincorporation of cyanobacterial non-proteogenic amino acids leading to mistranslation and protein misfolding. A better understanding of the interaction between the cyanopeptide metabolism and the nervous system will be crucial to target or to prevent pathogenic response.