ARTICLE | doi:10.20944/preprints201803.0151.v2
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: 3D culture; multiple myeloma; STAT; bortezomib; CETSA; stattic
Online: 8 June 2018 (13:32:11 CEST)
Malignant cells cultured in three-dimensional (3D) models have been found to be phenotypically and biochemically different from their counterparts cultured conventionally. Since most of these studies employed solid tumor types, how 3D culture affects multiple myeloma (MM) cells is not well understood. Here, we compared MM cells (U266 and RPMI8226) in a 3D culture model with those in conventional culture. While the conventionally cultured cells were present in single cells or small clusters, MM-3D cells grew in large spheroids. We discovered that STAT3 was the pathway that was more activated in 3D in both cell lines. The active form of STAT3 (phospho-STAT3 or pSTAT3), which was absent in MM cells cultured conventionally, became detectable after 1-2 days in 3D culture. This elevated pSTAT3 level was dependent on the 3D environment, since it disappeared after transferring to conventional culture. STAT3 inhibition using a pharmacological agent, Stattic, significantly decreased the cell viability of MM cells and sensitized them to bortezomib in 3D culture. Using an oligonucleotide array, we found that 3D culture significantly increased the expression of several known STAT3 downstream genes implicated in oncogenesis. Since most primary MM tumors are naturally STAT3-active, studies of MM in 3D culture can generate results that are more representative of the disease.
REVIEW | doi:10.20944/preprints201801.0240.v1
Subject: Biology, Other Keywords: epoxyqinomicin; DHMEQ; metastasis; invasion; adhesion; 3D cell culture
Online: 25 January 2018 (10:27:11 CET)
We previously designed and synthesized dehydroxyepoxyquinomicin (DHMEQ) as an inhibitor of NF-κB based on the structure of microbial secondary metabolite epoxyquinomicin C. DHMEQ showed anti-inflammatory and anticancer activity in various in vivo disease models without toxicity. Cell detachment from the primary tumor and subsequent invasion are considered to be early phase of metastasis, while tumor cell attachment to the tissue and secondary tumor formation the late phase. The assay system for late phase was set up with intra-portal-vein injection of pancreatic cancer cells. Administration of DHMEQ was found to inhibit the liver metastasis possibly by decreasing the expression of MMP-9 and IL-8. Also when the pancreatic cancer cells treated with DHMEQ was inoculated into the peritoneal cavity of mice, the metastatic foci formation was inhibited. These results indicate that DHMEQ is likely to inhibit the late phase of metastasis. Meanwhile, we have recently employed three-dimensional (3D) culture of breast cancer cells for the model of early phase metastasis. DHMEQ inhibited the 3D invasion of breast cancer cells without toxicity. In this way, DHMEQ was shown to inhibit the late and early phases of metastasis. Thus, DHMEQ is likely to be useful for the suppression of cancer metastasis.
ARTICLE | doi:10.20944/preprints201907.0102.v1
Subject: Life Sciences, Biochemistry Keywords: microglia exosomes; 3D culture; proteomic study; glioma; neurites outgrowth
Online: 8 July 2019 (04:26:49 CEST)
Using a combination of pan proteomic platform associated with systemic biology analyses, we demonstrate that neonatal microglial cells derived from cortex and spinal cord expressed different phenotypes upon the physiological or pathological conditions. They also highlight great variability in protein production on both cellular and exosome levels. Bioinformatics data indicate for the cortical microglia anti-inflammatory and neurogenesis/tumorigenesis characteristics, while for the spinal cord microglia involvement in the inflammatory response. We confirmed these results by performing functional testing including neurite outgrowth assays in DRGs cell line, and glioma proliferation analysis in 3D spheroid cultures. Results from these in vitro assays indicate that the microglia located at different CNS areas reveal differential biological functions. While both microglia sources enhanced growth of DRGs axons, only the spinal microglia significantly attenuated glioma proliferation. Overall these findings are pointing to the fact that the origin of neonatal microglia affects the physio-pathological function, which may address the prevalence of the glioma in the brain in comparison with the spinal cord in adult.
ARTICLE | doi:10.20944/preprints201905.0005.v1
Subject: Life Sciences, Biotechnology Keywords: multicellular spheroids; 3D culture; gas-permeable plate; hydrogel beads; methylcellulose
Online: 3 May 2019 (14:20:44 CEST)
Culture systems for 3-dimensional tissues, such as multicellular spheroids, are indispensable for high-throughput screening of primary or patient-derived xenograft (PDX)-expanded cancer tissues. Oxygen supply to the center of such spheroids is particularly critical for maintaining cellular functions as well as avoiding the development of a necrotic core. In this study, we evaluated 2 methods to enhance oxygen supply: (1) using culture plate with gas-permeable polydimethylsiloxane (PDMS) membrane at its bottom and (2) embedding hydrogel beads in the spheroids. Culturing spheroids on PDMS increased cell growth and affected glucose/lactate metabolism and CYP3A4 mRNA expression and subsequent enzyme activity. The spheroids comprised 5000 Hep G2 cells and 5000 20 µm-diameter hydrogel beads did not develop a necrotic core for 9 days when cultured on a gas-permeable sheet. In contrast, central necrosis in spheroids lacking hydrogel beads was observed after day 3 of culture, even when using PDMS. These results indicate that the combination of gas-permeable culture equipment and embedded hydrogel beads improves culture 3D spheroids produced from primary or PDX-expanded tumor cells.
ARTICLE | doi:10.20944/preprints201810.0697.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: glioma; glioblastoma; pre-clinical drug development; 3D culture systems; radiotherapy
Online: 30 October 2018 (03:38:28 CET)
Glioblastoma (GBM), the most common and aggressive primary brain tumor in adults, remains one of the least treatable cancers. Current standard of care—combining surgical resection, radiation, and alkylating chemotherapy—results in a median survival of only 15 months. Despite decades of investment and research into the development of new therapies, most candidate anti-glioma compounds fail to translate into effective treatments in clinical trials. One key issue underlying this failure of therapies that work in pre-clinical models to generate meaningful improvement in human patients is the profound mismatch between drug discovery systems—cell cultures and mouse models—and the actual tumors they are supposed to imitate. Indeed, current strategies that evaluate the effects of novel treatments on GBM cells in vitro fail to account for a wide range of factors known to influence tumor growth. These include secreted factors, the brain’s unique extracellular matrix, circulatory structures, the presence of non-tumor brain cells, and nutrient sources available for tumor metabolism. While mouse models provide a more realistic testing ground for potential therapies, they still fail to account for the full complexity of tumor-microenvironment interactions, as well as the role of the immune system. Based on the limitations of current models, researchers have begun to develop and implement novel culture systems that better recapitulate the complex reality of brain tumors growing in situ. A rise in the use of patient derived cells, creative combinations of added growth factors and supplements, may provide a more effective proving ground for the development of novel therapies. This review will summarize and analyze these exciting developments in 3D culturing systems. Special attention will be paid to how they enhance the design and identification of compounds that increase the efficacy of radiotherapy, a bedrock of GBM treatment.
REVIEW | doi:10.20944/preprints202106.0471.v2
Subject: Biology, Physiology Keywords: Alzheimer’s Disease; microfluidics; lab-on-chip; 3D culture; organ-on-chip
Online: 23 August 2021 (13:38:28 CEST)
Alzheimer’s disease (AD) is a significant health concern worldwide with enormous social and economic impact globally. The gradual deterioration of cognitive functions and irreversible neuronal losses are primary features of the disease. Even after decades of research, most therapeutic options are merely symptomatic, and drugs in clinical practice present numerous side effects. Lack of effective diagnostic techniques prevents the early prognosis of disease, resulting in a gradual deterioration in the quality of life. Furthermore, the mechanism of cognitive impairment and AD pathophysiology is poorly understood. Microfluidics exploits different microscale properties of fluids to mimic environments on microfluidic chip-like devices. These miniature multichambered devices can be used to grow cells and 3D tissues in vitro, analyze cell-to-cell communication, decipher the roles of neural cells like microglia, and gain insights into AD pathophysiology. This review focuses on the applications and impact of microfluidics on AD research. We discuss the technical challenges and possible solutions provided by this new cutting-edge technique to understand disease-associated pathways and mechanisms.
ARTICLE | doi:10.20944/preprints202208.0242.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: hydrogel; 3D-culture; Imaging; Cell-matrix; proteases; matrix metalloproteinases; actin polymerization; contractility
Online: 12 August 2022 (12:55:21 CEST)
Cancer invasion through basement membranes represents the initial step of tumor dissemination and metastasis. However, little is known about how human cancer cells breach basement membranes. Here, we used a 3-dimensional in vitro invasion model consisting of cancer spheroids encapsulated by a basement membrane and embedded in 3D collagen gels to visualize the early events of cancer invasion by confocal microscopy and live-cell imaging. Human breast cancer cells generated large numbers of basement membrane perforations, or holes, of varying sizes that expanded over time during cell invasion. We used a wide variety of small molecule inhibitors to probe the mechanisms of basement membrane perforation and hole expansion. Protease inhibitor treatment (BB94), led to a 63% decrease in perforation size. After myosin II inhibition (blebbistatin), basement membrane perforation area decreased by only 15%. These treatments produced correspondingly decreased cellular breaching events. Interestingly, inhibition of actin polymerization dramatically decreased basement membrane perforation by 80% and blocked invasion. Our findings suggest that human cancer cells can primarily use proteolysis and actin polymerization to perforate the BM and to expand perforations for basement membrane breaching, with a relatively small contribution from myosin II contractility.
ARTICLE | doi:10.20944/preprints202112.0178.v1
Subject: Materials Science, Biomaterials Keywords: hydrogel dressing; full-thickness skin regeneration; 3D cell culture; VE-cadherin; FGF
Online: 10 December 2021 (13:10:47 CET)
The process of full-thickness skin regeneration is complex and has many parameters involved, which makes it difficult to use a single dressing to meet the various requirements of the complete regeneration at the same time. Therefore, developing hydrogel dressings with multifunction, including tunable rheological properties and aperture, hemostatic, antibacterial and super cytocompatibility, is a desirable candidate in wound healing. In this study, a series of complex hydrogels were developed via the hydrogen bond and covalent bond between chitosan (CS) and alginate (SA). These hydrogels exhibited suitable pore size and tunable rheological properties for cell adhesion. Chitosan endowed hemostatic, antibacterial properties and great cytocompatibility and thus solved two primary problems in the early stage of the wound healing process. Moreover, the sustained cytocompatibility of the hydrogels was further investigated after adding FGF and VE-cadherin via the co-culture of L929 and EC for 12 days. The confocal 3D fluorescent images showed that the cells were spherical and tended to form multicellular spheroids, which distributed in about 40-60μm thick hydrogels. Furthermore, the hydrogel dressings significantly accelerate defected skin turn to normal skin with proper epithelial thickness and new blood vessels and hair follicles through the histological analysis of in vivo wound healing. The findings mentioned above demonstrated that the CS/SA hydrogels with growth factors have tremendous potential as multifunctional hydrogel dressings for full-thickness skin regeneration incorporated with hemostatic, antibacterial, sustained cytocompatibility for 3D cell culture and normal skin repairing.
COMMUNICATION | doi:10.20944/preprints202204.0070.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: 3D cell culture; patch-clamp; spheroids; single-channel recording; ion channels; mesenchymal stem cells
Online: 8 April 2022 (03:29:15 CEST)
Tri-dimensional (3D) cell aggregates or spheroids are considered to be closer to physiological conditions than traditional 2D cell culture. Mesenchymal stem cells (MSCs) assembling in spheroids have increased the survival of transplanted cells. The regulation of the biological processes that maintain crucial physiological reactions of MSCs is closely related to the functioning of ion channels. The pattern of expression, role and regulatory mechanisms of ion channels could be significantly different in 3D compared to 2D culture, and, thus, needed to be properly analyzed on the level of ionic currents. We developed a specific approach that allowed us to register, for the first time, endogenous ion channels in endometrial MSCs (eMSCs) assembled in spheroids. Particularly, using the single-channel patch-clamp technique, we have recorded the activity of ion channels and observed their functional interplay in mechanosensitive clusters. Our experimental protocol could be applied for identification and studying of ion channels in 3D cell cultures.
ARTICLE | doi:10.20944/preprints202109.0357.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Biofabrication; Bioprinting; Drop-on-demand; Microvalve; Micro-tissue; 3D Cell culture; Autologous Chondrocyte Implantation
Online: 21 September 2021 (11:16:07 CEST)
Recent improvements within the fields of high-throughput screening and 3D tissue culture have provided the possibility of developing in vitro micro-tissue models that can be used to study diseases and screen potential new therapies. This paper reports a proof of concept study on the use of microvalve-based bioprinting to create laminar MSC-chondrocyte co-cultures as an in vitro model of autologous chondrocyte implantation (ACI), an established cellular therapy for osteoarthritis. Microvalve-based bioprinting uses microvalves to deposit cells suspended in a liquid in a consistent and repeatable manner. In this case MSCs and chondrocytes have been sequentially deposited into an insert based transwell system in order to create a laminar co-culture, with variations in the ratios of the cell types used to investigate the potential for MSCs to stimulate improved repair. Histological and indirect immunofluorescence staining revealed the formation of dense tissue structures within the chondrocyte and MSC-chondrocyte cell co-cultures, alongside the establishment of a proliferative region at the base of the tissue. No stimulatory or inhibitory effect in terms of ECM production was observed through the introduction of MSCs, although the potential for an immunomodulatory benefit remains. This proof-of-concept study therefore provides a novel method to enable the scalable production of therapeutically relevant micro-tissue models that can be used for in vitro research to optimise ACI procedures.
ARTICLE | doi:10.20944/preprints202003.0371.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: matrix metalloproteinase 3 (MMP3); extracellular vesicles (EVs); tumoroid; tumor organoid; tumorigenesis; three-dimensional (3D) culture system
Online: 25 March 2020 (05:25:09 CET)
The tumor organoid (tumoroid) model in three-dimensional (3D) culture systems has been developed to reflect more closely the in vivo tumors than 2D-cultured tumor cells. Notably, extracellular vesicles (EVs) are efficiently collectible from the culture supernatant of gel-free tumoroids. Matrix metalloproteinase (MMP) 3 is a multi-functional factor playing crucial roles in tumor progression. However, roles of MMP3 within tumor growth and EVs have not unveiled. Here, we investigated the protumorigenic roles of MMP3 on integrities of tumoroids and EVs. We generated MMP3-knockout (KO) cells using the CRISPR/Cas9 system from rapidly metastatic LuM1 tumor cells. Moreover, we established fluorescent cell lines with palmitoylation signal-fused fluorescent proteins (tdTomato and enhanced GFP). Then we confirmed the exchange of EVs between cellular populations and tumoroids. LuM1-tumoroids released large EVs (300-1000 nm) and small EVs (50-200 nm) while the knockout of MMP3 resulted in the additional release of broken EVs from tumoroids. The loss of MMP3 leads to a significant reduction in tumoroid size and to the development of the necrotic area within tumoroids. MMP3 and CD9 (a category-1 EV marker tetraspanin protein) were significantly down-regulated in MMP3-KO cells and their EV fraction. These weakened phenotypes by MMP3 KO were markedly rescued by the addition of MMP3-rich EVs or conditioned medium (CM) collected from LuM1-tumoroids, which caused a dramatic rise in the expression of MMP3, CD9, and Ki-67 (a marker of proliferating cells) in the MMP3-null/CD9-low tumoroids. Notably, MMP3 enriched in tumoroids-derived EVs and CM deeply penetrated into recipient MMP3-KO tumoroids, resulting in a remarkable enlargement of solid tumoroids, while MMP3-null EVs did not. These data demonstrate that EVs can mediate molecular transfer of MMP3 resulting in increasing the proliferation and CD9+ tumorigenesis, indicating crucial roles of MMP3 in tumor progression.
ARTICLE | doi:10.20944/preprints202208.0461.v1
Subject: Social Sciences, Economics Keywords: Rice; Fish; Culture; Efficiency; Environment; Rice-Fish Culture
Online: 26 August 2022 (14:04:49 CEST)
The efficiency of rice cum fish culture study was conducted in different areas of Tangail district with those farmers who cultivate rice and fish together at a time. The study was conducted along 60 farmers of different areas in Ghatail upazilla. The primary data were collected through face-to-face interviews and secondary data were collected through different reputed journals, newspapers, authentic portals and so on. Data collection was carried out during the period from November 2021 to May 2022. Both tabular and functional analyses were performed to achieve the specific objectives of the study. NPV, BCR and IRR method was used to estimate the profitability and a multiple regression model was used to find out the factors motivating farmers' decision on rice cum fish cultivation. SWOT analysis was done to find out the internal and external-positive and negative factors faced by the farmers in rice cum fish cultivation. About 40% of farmers are under the age of 30 and most of them got at least primary education. Agriculture was the main occupation of the respondents and fish cultivation was the secondary. The highest annual income among the sample growers came from the production of rice cum fish culture. The BCR of the production is upbeat and 2.09 which indicates that the cultivation is profitable.
REVIEW | doi:10.20944/preprints201806.0011.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: spheroid culture; microfluidic cell culture; spheroids on-chip; tumor microenvironment; in vitro cell culture
Online: 1 June 2018 (09:58:58 CEST)
Three-dimensional (3D) cell culture systems can be regarded as suitable platforms to bridge the huge gap between animal studies and two-dimensional (2D) monolayer cell culture to study chronic diseases such as cancer. In particular, the preclinical platforms for multicellular spheroid formation and culture can be regarded as ideal in vitro tumor models. The complex tumor microenvironment such as hypoxic region and necrotic core can be recapitulated in 3D spheroid configuration. Cells aggregated in spheroid structures can better illustrate the performance of anti-cancer drugs as well. Various methods have been proposed so far to create such 3D spheroid aggregations. Both conventional techniques and microfluidic methods can be used for generation of multicellular spheroids. In this review paper, we first discuss various spheroid formation phases. Then, the conventional spheroid formation techniques such as bioreactor flasks, liquid overlay and hanging droplet technique are explained. Next, a particular topic of the hydrogel in spheroid formation and culture is explored. This topic has received less attention in the literature. Hydrogels entail some advantages to the spheroid formation and culture such as size uniformity, the formation of porous spheroids or hetero-spheroids as well as chemosensitivity and invasion assays and protecting from shear stress. Finally, microfluidic methods for spheroid formation and culture are briefly reviewed.
ARTICLE | doi:10.20944/preprints202012.0582.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Liquid-based 3D culture; tumoroid; cisplatin resistance; imatinib (gleevec); tyrosine kinase inhibitor (TKI); organoid; spheroid; metastatic colorectal cancer (mCRC)
Online: 23 December 2020 (10:15:46 CET)
Researchers have developed and used several three-dimensional (3D) culture systems, including spheroids, organoids, and tumoroids. Drug resistance is a crucial issue involving recurrence in cancer patients. Many studies on anticancer drugs have been done in 2D culture systems, where-as 3D cultured tumoroids have many advantages for assessing drug sensitivity and resistance. Here, we aim to investigate whether Cisplatin (a DNA crosslinker), Imatinib (a multiple tyro-sine kinase inhibitor), and 5-Fluorouracil (5-FU: an antimetabolite) alter tumoroid growth of metastatic colorectal cancer (mCRC). To establish a liquid-based 3D multiplexing reporter assay system, LuM1 (a murine mCRC cell line) was stably transfected with the Mmp9 promoter-driven ZsGreen reporter gene, which was designated as LuM1/m9 cells and cultured in NanoCulture Plate (NCP), a 3D culture device. The larger tumoroids were not sensitive to Cisplatin and ex-pressed ABCG2 (a marker of cancer stem cells, a.k.a. a drug efflux transporter), whereas smaller cell-aggregates were more sensitive to Cisplatin. Both Imatinib and Cisplatin significantly in-creased tumoroid growth (larger than 300 μm2) and Mmp9 promoter activity and were not cytotoxic to the mCRC tumoroids. On the other hand, 5-FU was cytotoxic to the tumoroids and significantly inhibited tumoroid growth, although not completely. Thus, platinum resistance and imatinib resistance in mCRC were modeled using the liquid-based 3D cultured tumoroid system. The tumoroid culture is useful and easily accessible for the assessment of drug sensitivity and resistance.
ARTICLE | doi:10.20944/preprints202109.0085.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: chick embryo; 3D culture; tumor models in vitro; tissue engineering; metastasis; triple-negative breast cancer; liver; mesoporous silica nanoparticles; doxorubicin; micrometastasis
Online: 6 September 2021 (11:46:54 CEST)
Colonization of distant organs by tumor cells is a critical step of cancer progression. The initial avascular stage of this process (micrometastasis) remains almost inaccessible to study due to the lack of relevant experimental approaches. Here, we introduce an in vitro/in vivo model of organ-specific micrometastases of triple-negative breast cancer (TNBC) that is fully implemented in a cost-efficient chick embryo (CE) experimental platform. The model is built as three-dimensional (3D) tissue engineering constructs (TECs) combining human MDA-MB-231 cells and decellular-ized CE organ-specific scaffolds. TNBC cells colonized CE organ-specific scaffolds in 2-3 weeks, forming tissue-like structures. The feasibility of this methodology for basic cancer research, drug development and nanomedicine was demonstrated on a model of hepatic micrometastasis of TNBC. We revealed that MDA-MB-231 differentially colonize parenchymal and stromal com-partments of the liver-specific extracellular matrix (LS-ECM) and become more resistant to the treatment with molecular Doxorubicin (Dox) and Dox-loaded mesoporous silica nanoparticles than in monolayer cultures. When grafted on CE chorioallantoic membrane, LS-ECM-based TECs induced angiogenic switch. These findings may have important implications for the diag-nosis and treatment of TNBC. The methodology established here is scalable and adaptable for pharmacological testing and cancer biology research of various metastatic and primary tumors.
ARTICLE | doi:10.20944/preprints201807.0224.v2
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: pseudopterosin; triple negative breast cancer; glucocorticoid receptor alpha; dexamethasone; cell proliferation; 3D invasion; tumor spheroid; co-culture; interleukin 6; interleukin 8
Online: 2 August 2018 (06:08:31 CEST)
Pseudopterosin, produced by the sea whip of the genus Antillogorgia, possesses a variety of promising biological activities including potent anti-inflammatory effects. However, few studies examined pseudopterosin in the treatment of cancer cells and, to our knowledge, the ability to inhibit triple negative breast cancer (TNBC) proliferation or invasion has not been explored. Thus, we evaluated the as yet unknown mechanism of action of pseudopterosin: Pseudopterosin was able to inhibit proliferation of TNBC. Interestingly, analyzing breast cancer cell proliferation after knocking down glucocorticoid receptor α (GRα) revealed that anti-proliferative effects of pseudopterosin were significantly inhibited when GRα expression was reduced. Furthermore, pseudopterosin inhibited invasion of MDA-MB-231 3D tumor spheroids embedded in an extracellular-like matrix. Remarkably, the knockdown of GRα in 3D tumor spheroids revealed increased ability of cells to invade the surrounding matrix. In a co-culture, encompassing peripheral blood mononuclear cells (PBMC) and MDA-MB-231 cells, production of interleukin 6 (IL-6) and interleukin 8 (IL-8) significantly increased compared to monoculture. Notably, pseudopterosin proved to block cytokine elevation, representing key players in tumor progression, in the co-culture. Thus, our results reveal pseudopterosin treatment as a potential novel approach in TNBC therapy.
ARTICLE | doi:10.20944/preprints201608.0041.v1
Online: 4 August 2016 (10:19:55 CEST)
Taking into account the growing interest in microalgae to be used as raw material for biodiesel production, this research is aimed at analyzing the rheological behaviour of microalgae suspensions (Chlorella sp) at different culture times under eight different conditions (temperature, salinity and CO2, NO3 and PO4 levels) in order to estimate the energy demands of each step, with the purpose of optimizing a continuous feed tubular bioreactor construction. For each condition, it was calculated the biomass and oil yields, so as to correlate these results with rheological parameters. The suspension results indicated that the microalgae Chlorella sp is a non-Newtonian material with dilatant characteristics; the processing time hardly exerted an influence on the rheograms of the suspension of the microalgae Chlorella sp, except for the simultaneous conditions of low salinity and low CO2 content; NO3 and PO4 contents and the amount of supplements influenced the rheological parameters of the suspension of the microalgae Chlorella sp, when in low concentration of CO2 and low salinity levels.
ARTICLE | doi:10.20944/preprints202108.0417.v1
Subject: Social Sciences, Organizational Economics & Management Keywords: Safety Performance; Safety Culture; Resilience Culture; Paramedic; Training Institute; IPMA; PLS-SEM.
Online: 20 August 2021 (13:44:19 CEST)
An increasing number of studies have shown that safety culture factors have a substantial influence on safety performance in a variety of industrial sectors. These factors' impact on safety performance is unclear, especially at the public service and statutory authorities. On the other hand, the understanding of indicators for safety performance in every working sector in Malaysia is on the continuing progress. Hence, this study's contribution is to explore the influence of safety culture factors (i.e., management commitment and supervision in safety, safety system) and safety competence on safety performance in government paramedic training institutes. IPMA (importance-performance map analysis) is a technique used in Smart PLS to determine the significance and performance of each of these factors. The study was conducted via an online survey and involved 258 safety and health committee members in Ministry of Health paramedic training institute. As a matter of relevance, the IPMA's empirical data study revealed that management commitment and supervision in safety were the predominant factors in determining safety performance. Meanwhile, for performance, the findings showed that worker involvement, safety system, and safety competence perform well in determining the safety performance.
ARTICLE | doi:10.20944/preprints202002.0003.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: drug repositioning/repurposing; dopamine transporter (DAT); benztropine; tumoroids; signal transducer and activator of transcription (STAT); circulating tumor cells (CTC); three-dimensional (3D) culture
Online: 3 February 2020 (03:16:54 CET)
Tumor growth, progression, and therapy resistance are crucial factors in the prognosis of cancer. Properties of three-dimensional tumor-like organoids (tumoroids) more closely resemble in vivo tumors compared to two-dimensionally cultured cells and are therefore effectively used for assays and drug screening. We here established a repurposed drug for novel anticancer research and therapeutics using a tumoroid-based screening system. We screened 6 pharmacologically active compounds by using an original tumoroid-based multiplex phenotypic screening system with matrix metalloproteinase 9 (MMP9) promoter-driven fluorescence reporter for the evaluation of both tumoroid formation and progression. The effects of one of the hit compounds were examined on tumor formation and progression in vitro and in vivo. Antiparkinson drug benztropine was the most effective compound uncovered by the screen. Benztropine significantly inhibited in vitro tumoroid formation, cancer cell survival, and MMP9 promoter activity. Benztropine also reduced the activity of oncogenic signaling transducers and trans-activators for MMP9, including STAT3, NF-κB, and β-catenin, and properties of cancer stem cells / cancer-initiating cells. Benztropine and GBR-12935 directly targeted the dopamine transporter DAT/SLC6A3, whose genetic alterations such as amplification were correlated with poor prognosis for cancer patients. Benztropine also inhibited tumor growth, circulating tumor cell (CTC) number, and rate of metastasis in a tumor allograft model in mice. In conclusion, we propose the repurposing of benztropine for anticancer research and therapeutics that can suppress tumor progression, CTC, and metastasis of aggressive cancers by reducing key pro-tumorigenic factors.
REVIEW | doi:10.20944/preprints202202.0303.v1
Subject: Life Sciences, Biotechnology Keywords: 3D bioprinting; 3D printing; bioink; cancer; cell biology
Online: 24 February 2022 (08:08:44 CET)
Tumor cells evolve in a complex and heterogeneous environment composed of different cell types and an extracellular matrix. Current 2D culture methods are very limited in their ability to mimic the cancer cell environment. In recent years, various 3D models of cancer cells have been developed, notably in the form of spheroids/organoids, using scaffold or cancer-on-chip devices. However, these models have the disadvantage of not being able to precisely control the organization of multiple cell types in complex architecture and are sometimes not very reproducible in their production, and this is especially true for spheroids. Three-dimensional bioprinting can produce complex, multi-cellular, and reproducible constructs in which the matrix composition and rigidity can be adapted locally or globally to the tumor model studied. For these reasons, 3D bioprinting seems to be the technique of choice to mimic the tumor microenvironment in vivo as closely as possible. In this review, we discuss different 3D-bioprinting technologies, including bioinks and crosslinkers that can be used for in vitro cancer models, and the techniques used to study cells grown in hydrogels; finally, we provide some applications of bioprinted cancer models.
ARTICLE | doi:10.20944/preprints201807.0503.v1
Online: 26 July 2018 (04:31:39 CEST)
Propagation of human cytomegalovirus (CMV) in cultured cells results in genetic adaptations that confer improved growth in vitro and significant attenuation in vivo. Mutations in RL13 arise quickly during cell culture passage, while mutations in the UL128-131A locus emerge later during fibroblast passage and disrupt expression of a glycoprotein complex that is important for entry into epithelial and endothelial cells. As in vivo CMV replicates in the context of host antibodies, we reasoned that antibodies might mitigate the accumulation of adaptive mutations during cell culture passage. To test this, CMV in infant urine was used to infect replicate fibroblast cultures. One lineage was passaged in the absence of CMV-hyperimmuneglobulin (HIG) while the other was passaged with HIG in the culture medium. The former lost epithelial tropism and aquired mutations disrupting RL13 and UL131A expression, whereas the latter retained epithelial tropism and both gene loci remained intact after 22 passages. An epitheliotropic RL13+/ UL131A+ virus was isolated by limiting-dilution in the presence of HIG and expanded to produce a working stock sufficient to conduct cell tropism experiments. Thus, culture in the presence of antibodies may facilitate in vitro experiments using viruses that are genetically more authentic than has been previously possible.
ARTICLE | doi:10.20944/preprints202106.0281.v1
Online: 10 June 2021 (08:56:45 CEST)
In modern times like today, technology and science are developing very fast. This has resulted in a condition known as globalization. This era has had a significant impact on every country globally, including in Indonesia, such as the spread of culture is solid. This flow has many benefits and advantages. However, this globalization can also have a negative impact. One of them is the erosion of native Indonesian culture compared to foreign cultures. Therefore, this research to find the origin, causes, and impacts of the influx of cultural globalization on the current culture of East Java because it is the province of origin of the researchers. Here the researchers asks about the impact of this modern culture and how influential culture is to the people of East Java. The method used by the researchers in making this paper is Literature Review using qualitative descriptive writing with quantitative data. The researchers findings as material in this paper amounted to 24 materials with the provisions of 20 journal article materials, 2 article materials online provided that they were published in the last three years, and 2 E-books for methods on this paper. This study's boundaries are a modern culture that the researchers takes about western culture (western) and South Korean culture (Hallyu). In addition, this study only discusses cultures originating in East Java, such as Javanese.
ARTICLE | doi:10.20944/preprints202104.0424.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: culture; facial expressions; emotion; posed; spontaneous
Online: 15 April 2021 (16:45:31 CEST)
There is a growing consensus that culture influences the perception of facial expressions of emotion. However, little is known about whether and how culture shapes the production of emotional facial expressions, and even less so about whether culture differentially shapes the production of posed versus spontaneous expressions. Drawing on prior work on cultural differences in emotional communication, we tested the prediction that people from the Netherlands (a historically heterogeneous culture where people are prone to low-context communication) produce facial expressions that are more distinct across emotions compared to people from China (a historically homogeneous culture where people are prone to high-context communication). Furthermore, we examined whether the degree of distinctiveness varies across posed and spontaneous expressions. Dutch and Chinese participants were instructed to either pose facial expressions of anger and disgust, or to share autobiographical events that elicited spontaneous expressions of anger or disgust. Using the complementary approaches of supervised machine learning and information-theoretic analysis of facial muscle movements, we show that posed and spontaneous facial expressions of anger and disgust were more distinct when produced by Dutch compared to Chinese participants. These findings shed new light on the role of culture in emotional communication by demonstrating, for the first time, effects on the distinctiveness of production of facial expressions.
ARTICLE | doi:10.20944/preprints202009.0637.v1
Online: 26 September 2020 (13:44:40 CEST)
Malassezia is lipid-dependent commensal yeast of the human skin. The different culture media and skin sampling methods used to grow these fastidious yeasts are a source of heterogeneity in culture-based epidemiological study results. This study aimed to compare the performances of three methods of skin sampling, and two culture media for the detection of Malassezia yeasts by culture from the human skin. Three skin sampling methods, namely sterile gauze, dry swab and TranswabTM with transport medium, were applied on 10 healthy volunteers. Each sample was further inoculated onto either the novel FastFung medium or the reference Dixon agar for the detection of Malassezia spp. by culture. At least one colony of Malassezia spp. grew on 93/300 (31%) of the cultures, corresponding to 150 samplings. The positive culture rate was 67%, 18%, and 15% (P < 10-3), for samples collected with sterile gauze, TranswabTM, and dry swab, respectively. The positive culture rate was 62% and 38% (P < 0.003) by using the FastFung and the Dixon media, respectively. Our results showed that sterile gauze rubbing skin sampling followed by inoculation on FastFung medium should be implemented in the routine clinical laboratory procedure for Malassezia spp. cultivation.
ARTICLE | doi:10.20944/preprints202009.0531.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: polystyrene; tissue culture; cell membrane stability
Online: 23 September 2020 (03:46:57 CEST)
Unanticipated errors in scientific research data can be attributed to the unwarranted assumption of uniformity in the polystyrene surface that is ubiquitously used in tissue culture flasks and dishes. We have shown that when adherent cells are subjected to fluid shear force, equivalent to rinsing the culture with a balanced salt solution, cells on some areas of the polystyrene surface will immediately rupture while still adherent on the surface. This heterogeneity on the polystyrene surface can cause unexpected variability in experimental results and in replicating experiments among labs. In this paper a novel quantitative method is described to measure the degree of heterogeneity on the polystyrene surface of tissue culture flasks. The results show significant variation among several brands of tissue culture flasks as well as large variability within the production lot of a manufacturer. The assay method involves loading the cells with a fluorescent marker that is released upon membrane rupture. Cell membrane rupture also causes the loss of marker proteins used in Westernblots. This novel assay method can be used to monitor the batch consistency and the manufacturing process of flasks and dishes. It may also be used to test new biomaterials.
ARTICLE | doi:10.20944/preprints202009.0329.v1
Online: 15 September 2020 (04:41:50 CEST)
Intersectional experiences, socio-cultural meanings, ethnic traditions and morals compound stigma-related stress (Jackson et al., 2020; Schmitz 2019). Sex workers are subject to various stigmatizing forces which can lead to secrecy, isolation and lack of social and cultural support (Koken 2012). Stigmatizing forces include structural humanitarian governance and aid interventions that conflate migration and sex work with insidious constraints and coercion. This study explored how migrant female sex workers from distinctive ethnic cultures manage their identity on a day to day basis in relation to the separation of work and home life. Methods: The perspectives of female sex workers were collected via a series of in-depth semi-structured interviews. The inclusion criteria were that the women had worked in sex work for over 18months, defined their involvement in sex work as voluntary, and were over 18yrs of age. The perspectives of seven women from South Asian (Pakistani), Brazilian, and British backgrounds were analyzed using Grounded Theory (Glaser and Strauss, 1967). Ethnicity was considered to explore how the women experienced stigma, how it impacted on the management of their identity, and how the process of change occurred. Results: The women used a variety of methods to maintain work and home life boundaries, processes they used switch into a role and all experienced stigma and tried to deal with it in ways such as concealment from friends and family. Two core categories and properties emerged from the data as participants felt guilt and/or shame but only the South Asian participants spoke of this with reference to their culture and religion. Conclusion: It was not migration per se but rather the relationship of migration to culture that was key to identity management. Participants reflected that as their country was considered collectivist country with interdependent thought, that any negativity felt could not only be reflected on the individual, but also the entire family. For these reasons Pakistani sex workers were subject to more complex stigmatizing forces, shame and guilt as regards risk and exposure. Discussion focusses on the processes and management strategies used to extend social and cultural support.
ARTICLE | doi:10.20944/preprints201809.0167.v1
Subject: Biology, Other Keywords: Temperature, Culture, Cell, Chick, Embryo, Rotation
Online: 10 September 2018 (12:02:12 CEST)
Recently, some authors have developed a shell-less culture system for chick embryos by using a plastic lm as culture vessels. We will show that velocity of rotation of vessels in incubator and temperature have direct relations with growth of chick embryos. We also obtain a mathematical relation between velocity, temperature and rate of growth of chick embryo.
ARTICLE | doi:10.20944/preprints201803.0006.v2
Subject: Earth Sciences, Environmental Sciences Keywords: agrobiodiversity; environment; ecosystem; culture; farms; planning
Online: 9 May 2018 (07:37:48 CEST)
This document presents, from environmental thinking (ecosystem - culture relations), the concept of the Main Agroecological Structure of Agroecosystems (MAS, EAP, for its acronym in Spanish), considered as a dissipative cultural structure. It discusses its possible applications (resilience, production, diversity) both inside and outside the farms. The MAS can be useful in the land planning on the farms, based on the concept of potential MAS that allows the quantification of the management of internal and external corridors, including natural vegetation. At the same time, it can be useful in the context of landscape management because it shows a series of cultural relations (economic, social, symbolic and technological) hidden from the partial analysis of landscape ecology.
ARTICLE | doi:10.20944/preprints201711.0141.v1
Subject: Behavioral Sciences, Other Keywords: organizational culture; mission; consistency; involvement; adaptability
Online: 22 November 2017 (04:19:38 CET)
The main goal of this paper is to address how quickly and to what extent are international organizational cultures, brought by the world companies after the process of privatization, being implemented in a single monolithic culture. For this purpose was adopted and applied Denison model of organizational culture, which has been chosen because it emphasizes the need for balance between requirements for organization’s stability demands and its required flexibility. Considering that a different organizational culture reflects systematic change of an entire organization, this paper focuses on exploring the differences in culture dimensions among companies in domestic and foreign ownership in Serbia. A sample of 1000 employees was statistically processed. Changes in organizational culture tend to be relatively slow. The results confirm that organizational culture is a complex working environment, concerning organizational values, which represents a fundamental element of organizations. Given that the process of company ownership changes occurred fifteen years prior to the research implementation, obtained results show effects of interaction between national and organizational culture in this, relatively short, period of time. Obtained results can be generalized to countries that are passing or have recently passed a transition, and are similar in cultural characteristics.
ARTICLE | doi:10.20944/preprints201807.0408.v1
Subject: Medicine & Pharmacology, Other Keywords: quality of work life; organizational culture; organizational support; self-efficacy; maritime workers; culture-work-health model
Online: 23 July 2018 (10:00:06 CEST)
Using the culture-work-health model, this study investigates the factors influencing the quality of life of maritime workers. This study conducted a survey of 320 maritime workers who have experience living and working on a ship for more than six months. This self-administered questionnaire included questions on organizational culture and support, self-efficacy, perceived fatigue, as well as the quality of work life. Organizational culture and self-efficacy were identified as factors affecting the quality of work life, while organizational support was found to have an indirect effect after passing through self-efficacy and perceived fatigue. The final model accounts for 63.1% of the variance in maritime workers’ quality of life. As such, this study shows that self-efficacy is important for the quality of life of maritime workers, having both direct and indirect effects. Moreover, organizational support may prove the primary intervention point for relieving perceived fatigue and enhancing self-efficacy, thus improving the quality of work life.
ARTICLE | doi:10.20944/preprints201704.0075.v1
Subject: Physical Sciences, Applied Physics Keywords: femtosecond laser 3D microfabrication; 3D printing; nanotechnology; microfluidics; lab-on-chip
Online: 13 April 2017 (10:32:29 CEST)
An approach employing ultrafast laser hybrid subtractive-additive microfabrication combining ablation, 3D nanolithography and welding is proposed for the realization of Lab-On-Chip (LOC) device. Single amplified Yb:KGW fs-pulsed laser source is shown to be suitable for fabricating microgrooves in glass slabs, polymerization of fine-meshes filter out of hybrid organic-inorganic photopolymer SZ2080 inside them, and, lastly, sealing the whole chip with cover glass into a single monolithic piece. The created microfluidic device proved its particle sorting function by separating 1 μm and 10 μm polystyrene spheres in a mixture. All together, this shows that fs-laser microfabrication technology is a flexible and versatile tool for the manufacturing of mesoscale multi-material LOC devices.
ARTICLE | doi:10.20944/preprints202111.0466.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: 3D Zernike moments; 3D Zernike radial polynomials; 3D Zernike polynomials; Spherical harmonics; Recurrence formula; Matrix Lie Group; Group action
Online: 25 November 2021 (09:54:08 CET)
3D Zernike moments based on 3D Zernike polynomials have been successfully applied to the field of voxelized 3D shape retrieval and have attracted more attention in biomedical image processing. As the order of 3D Zernike moments increases, both computational efficiency and numerical accuracy decrease. Due to this phenomenon, a more efficient and stable method for computing high-order 3D Zernike moments was proposed in this study. The proposed recursive formula for computing 3D Zernike radial polynomials combines the recursive calculation of spherical harmonics to develop a voxel-based algorithm for the calculation of 3D Zernike moments. The algorithm was applied to the 3D shape Michelangelo's David with a size of 150×150×150 voxels. As compared to the method without additional acceleration, the proposed method uses a group action of order sixteen orthogonal group and saving unnecessary iterations, the factor of speed-up is 56.783±3.999 when the order of Zernike moments is between 10 and 450. The proposed method also obtained an accurate reconstructed shape with the error rate (normalized mean square error) of 0.00 (4.17×10^-3) when the reconstruction was computed for all moments up to order 450.
ARTICLE | doi:10.20944/preprints202102.0104.v1
Online: 3 February 2021 (10:07:28 CET)
In the production of green parts from powder, there is unavoidable slight deviation in the die filling, even when high-quality powders are used. The quantity of powder in the die varies and thus affects the weight of the compact. This filling variation results in variation of the pressing force, and thus influences the part geometry. The development of the DORST Netshape® System was conceived as an autonomous manufacturing system in order to compensate for these effects. Based on the Dorst Industry 4.0 innovations for part weight measuring immediately after pressing in combination with a laser dimension measuring system, this technology package attempts to reach enhanced precision and consistency in production. The paper presents results from various trials that show the capability of this new system, designed to improve the quality of pressed parts.
ARTICLE | doi:10.20944/preprints202102.0103.v1
Online: 3 February 2021 (10:07:12 CET)
This paper presents the results of the investigation of composite sinters W-TiB2 which were used as an electrode in the process of electro-spark deposition (ESD) and the examination of the deposited layers. The scope of the study includes detailed characteristics of powder mixtures, composite sinters made using the spark plasma sintering method (SPS) and layers deposited in the electro-spark process. The ESD process, using the W+30 vol.% TiB2 electrode, was carried out using an automated device. The substrates were made of copper and aluminium. The topography analysis of the surfaces of the composite layer and the evaluation of their wear resistance properties are also presented. The analysis of the results of research showed the possibility to obtain, using the SPS method, composite materials of good quality, which can be used as electrodes in the ESD process. The obtained layers had increased wear resistance in relation to the substrate material.
ARTICLE | doi:10.20944/preprints202102.0041.v1
Online: 1 February 2021 (14:07:02 CET)
We present progress in fast, high-resolution imaging, material classification, and fault detection using hyperspectral X-ray measurements. Classical X-ray CT approaches rely on data from many projection angles, resulting in long acquisition and reconstruction times. Additionally, conventional CT cannot distinguish between materials with similar densities. However, in additive manufacturing, the majority of materials used are known a priori. This knowledge allows to vastly reduce the data collected and increase the accuracy of fault detection. In this context, we propose an imaging method for non-destructive testing of materials based on the combination of spectral X-ray CT and discrete tomography. We explore the use of spectral X-ray attenuation models and measurements to recover the characteristic functions of materials in heterogeneous media with piece-wise uniform composition. We show by means of numerical simulation that using spectral measurements from a small number of angles, our approach can alleviate the typical deterioration of spatial resolution and the appearance of streaking artifacts.
ARTICLE | doi:10.20944/preprints202102.0026.v1
Online: 1 February 2021 (12:41:04 CET)
Fatigue remains a challenge especially for high end metal AM parts and materials. From a design perspective, the fatigue limit of an AM solution can be improved upon by optimizing the manufacturing process for a certain material and part. In addition, improved accuracy of design methodologies aids in capturing the features critical for fatigue and quantifies their significance to desired part lifetime as well as providing a basis for their avoidance. In current work we present an overall concept merging thermomechanical process and powder bed solidification modeling to micromechanical analysis of fatigue of the resulting material microstructure. Material features critical to fatigue, particularly surface roughness, internal defects such as porosity and cracks and on the other hand inclusions, can be assessed directly on the basis of AM part microstructure with respect to the resulting fatigue limit. Case analyses consist of maraging steel and nickel alloys. The overall scheme provides a basis for optimization of metal AM solutions against fatigue and multiscale modeling founded basis for fatigue design.
Online: 29 January 2021 (11:59:58 CET)
Quality assurance has been one of the major challenges in laser-based additive manufacturing (AM) processes. This study proposes a novel process modeling methodology for layer-wise in-situ quality monitoring based on image series analysis. An image-based autoregressive (AR) model has been proposed based on the image registration function between consecutively observed thermal images. Image registration is used to extract melt pool location and orientation change between consecutive images, which contains sensing stability information. Subsequently, a Gaussian process model is used to characterize the spatial correlation within the error matrix. Finally, the extracted features from the aforementioned processes are jointly used for layer-wise quality monitoring. A case study of a thin wall fabrication by a Directed Laser Deposition (DLD) process is used to demonstrate the effectiveness of the proposed methodology.
Online: 28 January 2021 (15:30:45 CET)
Additive Manufacturing (AM) simplifies the fabrication of complex geometries. Its scope has rapidly expanded from the fabrication of pre-production visualization models to the manufacturing of end use parts driving the need for better part quality assurance in the additively manufactured parts. Machine learning (ML) is one of the promising techniques that can be used to achieve this goal. Current research in this field includes the use of supervised and unsupervised ML algorithms for quality control and prediction of mechanical properties of AM parts. This paper explores the applications of supervised learning algorithms - Support Vector Machines and Random Forests. Support vector machines provide high accuracy in classifying the data and is used to decide whether the final parts have the desired properties. Random Forests consist of an ensemble of decision trees capable of both classification and regression. This paper reviews the implementation of both algorithms and analyzes the research carried out on their applications in AM.
BRIEF REPORT | doi:10.20944/preprints202012.0772.v1
Online: 31 December 2020 (09:08:09 CET)
OBJECTIVE: Although 3D-printed anatomic models are not new to medicine, the high costs and lengthy production times entailed have limited their application. Our goal was developing a new and less costly 3D modeling method to depict organ-tumor relations at faster printing speeds. METHODS: We have devised a method of 3D modeling using DICOM images. Coordinates are extracted at a specified interval, connecting them to create mesh-work replicas. Adjacent constructs are depicted by density variations, showing anatomic targets (ie, tumors) in contrasting color. RESULTS: An array of organ solid-tumor models were printed via Fused Deposition Modeling 3D printer at significantly less cost ($0.05/cm3) and time expenditure (1.73 min/cm3; both, p<.001). Printed models helped promote visual appreciation of organ-tumor anatomy and adjacent tissues. Our mesh-work 3D thyroidal prototype reproduced glangular size/contour and tumor location, readily approximating the surgical specimen. CONCLUSIONS: This newly devised mesh-type 3D printing method may facilitate anatomic modeling for personalized care and improve patient awareness during informed surgical consent.
ARTICLE | doi:10.20944/preprints201704.0082.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: 3D Printing; Microfluidics; Micromixing
Online: 14 April 2017 (06:03:24 CEST)
3D printing facilitates the straightforward construction of microchannels with complex three-dimensional architectures. Here, we demonstrate 3D-printed modular mixing components that operate on the basis of splitting and recombining fluid streams to decrease interstream diffusion length. These are compared to helical mixers that operate on the principle of chaotic advection.
ARTICLE | doi:10.20944/preprints202110.0362.v1
Subject: Mathematics & Computer Science, Probability And Statistics Keywords: 3D reconstruction; 3D data smoothing; mesh simplification; high resolution micro-CT images
Online: 25 October 2021 (15:34:27 CEST)
Three-dimensional reconstruction plays an important role in assisting doctors and surgeons in diagnosing bone defects’ healing progress. Common three-dimensional reconstruction methods include surface and volume rendering. As the focus is on the shape of the bone, volume rendering is omitted. Many improvements have been made on surface rendering methods like Marching Cubes and Marching Tetrahedra, but not many on working towards real-time or near real-time surface rendering for large medical images, and studying the effects of different parameter settings for the improvements. Hence, in this study, an attempt towards near real-time surface rendering for large medical images is made. Different parameter values are experimented on to study their effect on reconstruction accuracy, reconstruction and rendering time, and the number of vertices and faces. The proposed improvement involving three-dimensional data smoothing with convolution kernel Gaussian size 0.5 and mesh simplification reduction factor of 0.1, is the best parameter value combination for achieving a good balance between high reconstruction accuracy, low total execution time, and a low number of vertices and faces. It has successfully increased the reconstruction accuracy by 0.0235%, decreased the total execution time by 69.81%, and decreased the number of vertices and faces by 86.57% and 86.61% respectively.
TECHNICAL NOTE | doi:10.20944/preprints202007.0556.v1
Subject: Earth Sciences, Geoinformatics Keywords: Solar radiation; 3D city models; Urban environment; GRASS GIS r.sun; 3D extension
Online: 23 July 2020 (12:20:40 CEST)
Solar3D is an open-source software application designed to interactively calculate solar irradiation at three-dimensional (3D) surfaces in a virtual environment constructed with combinations of 3D city models, digital elevation models (DEMs), digital surface models (DSMs) and feature layers. The GRASS GIS r.sun solar radiation model computes solar irradiation based on two-dimensional (2D) raster maps for given day, latitude, surface and atmospheric conditions. With the increasing availability of 3D city models and demand for solar energy, there is an urgent need for better tools to computes solar radiation directly with 3D city models. Solar3D extends GRASS GIS r.sun from 2D to 3D by feeding the model with input, including surface slope, aspect and time-resolved shading, that is derived directly from the 3D scene using computer graphics techniques. To summarize, Solar3D offers several new features which, as a whole, distinguish itself from existing 3D solar irradiation tools: (1) the ability to consume massive heterogeneous 3D city models, including massive 3D city models such as oblique airborne photogrammetry-based 3D city models (OAP3Ds or integrated meshes); (2) the ability to perform near real-time pointwise calculation for duration from daily to annual; (3) the ability to integrate and interactively explore large-scale heterogeneous geospatial data. (4) the ability to calculate solar irradiation at arbitrary surface positions including at rooftops, facades and the ground. Solar3D is publicly available at https://github.com/jian9695/Solar3D.
REVIEW | doi:10.20944/preprints202003.0220.v1
Subject: Biology, Ecology Keywords: 3D printing; 3D scanning; customized ecological objects; methods; stereolithography; open-source lab
Online: 12 March 2020 (14:46:07 CET)
3D printing is described as the third industrial revolution: its impact is global in industry and progresses every day in society. It presents a huge potential for ecology and evolution, sciences with a long tradition of inventing and creating objects for research, education and outreach. Its general principle as an additive manufacturing technique is relatively easy to understand: objects are created by adding material layers on top of each other. Although this may seem very straightforward on paper, it is much harder in the real world. Specific knowledge is indeed needed to successfully turn an idea into a real object, because of technical choices and limitations at each step of the implementation. This article aims at helping scientists to jump in the 3D printing revolution, by offering a hands-on guide to current 3D printing technology. We first give a brief overview of uses of 3D printing in ecology and evolution, then review the whole process of object creation, split into three steps: (1) obtaining the digital 3D model of the object of interest, (2) choosing the 3D printing technology and material best adapted to the requirements of its intended use, (3) pre- and post-processing the 3D object. We compare the main technologies available and their pros and cons according to the features and the use of the object to be printed. We give specific and key details in appendices, based on examples in ecology and evolution.
ARTICLE | doi:10.20944/preprints202111.0556.v1
Online: 30 November 2021 (10:47:20 CET)
Museums increasingly recognize the need to address advances in digital culture which impact the expectations and needs of their audiences. Museum collections of real objects need to be presented both on their own premises and digitally online, especially as social media becomes more and more influential in people’s everyday lives. We investigate these challenges magnified by advances in digital and computational media and culture looking particularly at recent and relevant reports on changes in the ways museums interact with the public. We find that the Covid-19 pandemic has accelerated many of the changes driving museum transformation. We believe that museums must be more prepared than ever to adapt to unabated technological advances set in the midst of cultural and social revolution, now intrinsic to the digital landscape in which museums are inevitably connected and participating across the global digital ecosystem where they inevitably find themselves entrenched.
ARTICLE | doi:10.20944/preprints202104.0446.v1
Subject: Medicine & Pharmacology, Allergology Keywords: CTC, cell culture, liquid biopsy, breast cancer
Online: 16 April 2021 (13:29:37 CEST)
Background: Circulating tumor cells (CTC) have relevance as prognostic markers in breast cancer. However, the functional properties of CTCs or their molecular characterization have not been well-studied. Experimental models indicate that only a few cells can survive in the circulation and eventually metastasize. Thus, it is essential to identify these surviving cells capable of forming such metastases. Methods: We isolated viable CTCs from 50 peripheral blood samples obtained from 35 patients with advanced metastatic breast cancer using RosetteSepTM for ex vivo culture. The CTCs were seeded and monitored on plates under low adherence conditions and with media supplemented with growth factors and Nanoemulsions. Phenotypic analysis was performed by immunofluorescence and gene expression analysis using RT-PCR and CTCs counting by Cellsearch® system. Results: We found that in 75% of samples the CTC cultures lasted more than 23 days, predicting a shorter Progression-Free Survival in these patients, independently of having ≥ 5 CTC by Cellsearch®. We also observed that CTCs before and after culture showed a different gene expression profile. Conclusions: the cultivability of CTCs is a predictive factor. Furthermore, the subset of cells capable of growing ex vivo show stem or mesenchymal features and may represent the CTC population with metastatic potential in vivo.
ARTICLE | doi:10.20944/preprints201905.0135.v1
Subject: Biology, Animal Sciences & Zoology Keywords: Skin; Cell culture; Stem cells; Differentiation; Camel
Online: 10 May 2019 (15:04:59 CEST)
Elite camels often suffer from massive injuries. Thus, there is a pivotal need for a cheap and readily available regenerative medicine source. We isolated novel stem-like cells from camel skin and investigated their multipotency and resistance against various stresses. Skin samples were isolated from ears of five camels. Fibroblasts, keratinocytes, and spheroid progenitors were extracted. After separation of different cell lines by trypsinization, all cell lines were exposed to heat shock. Then, fibroblasts and dermal cyst-forming cells were examined under cryopreservation. Dermal cyst-forming cells were evaluated for resistance against osmotic pressure. The results revealed that resistance periods against trypsin were 1.5, 4, and 7 minutes for fibroblasts, keratinocytes, and spheroid progenitors, respectively. Furthermore, complete recovery of different cell lines after heat shock along with the differentiation of spheroid progenitors into neurons was observed. Fibroblasts and spheroid progenitors retained cell proliferation after cryopreservation. Dermal cyst-forming cells regained their normal structure after collapsing by osmotic pressure. The spheroid progenitors incubated in the adipogenic, osteogenic, and neurogenic media differentiated into the adipocytes, osteoblasts, and neurons, respectively. To the best of our knowledge, we isolated different unique cellular differons and stem-like cells from the camel skin and examined their multipotency for the first time.
ARTICLE | doi:10.20944/preprints201903.0281.v1
Subject: Social Sciences, Business And Administrative Sciences Keywords: Ethics, Ethical Culture and Sustainability, Family Business
Online: 29 March 2019 (12:09:05 CET)
Building an ethical culture is challenging and a basic requirement of the companies to embed transparency in their systems, creating a positive image; serving the internal and external communities. This paper based on detailed interviews of 12 family owned businesses over a period of 16 months explores how these companies build the ethical culture, identifying the ethical culture sustainability triggers, challenges and role of religion in such practices. The values, culture, community and social norms are identified as major ingredients of a sustainable ethical culture development and implementation of the ethical policies and procedures require institutional and structural mechanisms for effectiveness in family owned businesses. The findings at numerous occasions are in contrast to the literature, whereas, in other instances are similar. The religion, society, family image, the entrepreneurs themselves and their family members play a vital role. Non-interference in private matters of the employees, whistle blowing, code of ethics, training and awareness creation and a number of other factors play a leading role in ethical culture development in family businesses.
ARTICLE | doi:10.20944/preprints201901.0239.v1
Subject: Social Sciences, Sociology Keywords: Sustainability; Chinese culture; Moslem society; Malaysia; Indonesia
Online: 23 January 2019 (10:25:28 CET)
Abstract Sustainability of ethnic culture in Southeast Asia has made the dramatically growth of ethnic identity. The ethnic revivals already made the increasing of cultural events in public spaces. This research paper sought the cultural sustainability of Chinese in Moslem society of Southaest Asia. A multisited ethnography was conducted in Medan Municipal of North Sumatra and Georgetown Penang, Malaysia to observe the sustained Chinese culture as the symbol of ethnification of Chinese in Moslems society in Southeast Asia region. It found that after 2003 Indonesia already saw the attractive cultural performances of Chinese in public spaces as the continuation of sustainability. In our ethnographic investigation from 2014 -2017, the reshaping of the Chinese identity through sustainability of Chinese culture in Medan Municipality of North Sumatra, and Penang of Malaysia has the high public visibility. Research report showed the continuation of the Chinese rituals and festivals which were accompanied by music instruments of Chinese and theatrical performances. Those have been transformed from self commemorations to be more public; attractions already were moved to public places, not solely in temples or ethnic group surroundings as what commonly found in the past period. It concluded that the sustainability of Chinese culture in public spaces made the Southeast Asia connection among the Chinese groups solidify their identity in this region tightened.
ARTICLE | doi:10.20944/preprints201806.0377.v1
Subject: Social Sciences, Finance Keywords: risk culture; honourable merchant; decision-making; responsibility
Online: 25 June 2018 (10:21:18 CEST)
The current discussion about a “risk culture” in financial services was triggered by the recent series of crisis (from the US subprime mortgage crisis to the lock-in trap of central banks in the aftermath of the sovereign debt crisis). The last decade saw a long list of hybris, misconduct and criminal activities by human beings on a single or even a collective basis in banks, in the industry or in the whole economy. As a counter-reaction, financial authorities called for a guidance by a “new” risk culture in financial institutions based on a set of abstract, formal and normative governance processes. In the humanities, culture is a paraphrase for the behaviour in collectives and dynamics of organization found in human societies. Therefore, a “risk culture” should be a link between those normative guidelines and the positive “real-world” decision-making in financial services. This paper will focus on “risk culture” from the perspective of human beings interacting in dynamical and intertemporal commercial relations. In this context, “risk” is perceived by economic agents ex-ante as the consequence of the time-lag between the present and the uncertain future development (compared to a probability distribution calculated by observers ex-post). For all those individual decisions – to be made under uncertainty – future “risk” includes the so-called “normal accidents”, i.e. failures that will happen at some uncertain point in time but inevitable, and it is only the questions, when failure will happen and how to maintain function in the first line of defence. Finally, the sum of all decisions with individual responsibility for things to come is the positive economical context of a “risk culture” in the sense of the (rational) behaviour of an honourable merchant in long-term and repeated commercial relations in a merchant community, as this is a heritage of European business culture.
ARTICLE | doi:10.20944/preprints201612.0129.v1
Subject: Arts & Humanities, History Keywords: history; museology; Israeli culture; Holocaust; Israeli society
Online: 26 December 2016 (10:43:31 CET)
Tiny by physical size, the State of Israel retains some of the world’s most important cultural treasures, along with many other great cultural institutions. Archeological treasures have yielded much information as far as biblical history and have been well adapted to a Zionist narrative by both the Jewish press and international news organizations, such as the New York Times whose archives are replete with reports of Jewish history being dug up by the Jewish people. Once the State of Israel gained independence in 1948, the course was set for the development of historical museums whose discourse would reflect the most significant events in Jewish history, most especially the Holocaust and the state of constant warfare that continues to imbue the cultural consciousness of its citizens. In this paper we outline, through categorization, the various historical museums, which are currently operating. Furthermore, this article hopes to shed some light upon the cultural sensibilities conveyed through these institutions.
ARTICLE | doi:10.20944/preprints201811.0326.v2
Subject: Life Sciences, Biochemistry Keywords: cellular agriculture; cell-based seafood; fish tissue culture; bioreactor; serum-free media; ocean conservation; marine cell culture; aquaculture
Online: 25 January 2019 (11:36:58 CET)
Cellular agriculture is defined as the production of agricultural products from cell cultures rather than from whole plants or animals. With growing interest in cellular agriculture as a means to address the public health, environmental, and animal welfare challenges of animal agriculture, the concept of producing seafood from fish cell- and tissue-cultures is emerging as a means to address similar challenges with industrial aquaculture systems and marine capture. Cell-based seafood - as opposed to animal-based seafood - can combine developments in biomedical engineering with modern aquaculture techniques. Biomedical engineering developments such as closed-system bioreactor production of land animal cells create a basis for large scale production of marine animal cells. Aquaculture techniques such as genetic modification and closed system aquaculture have achieved marked gains in production that can pave the way for innovations in cell-based seafood production. Here, we present the current state of innovation relevant to the development of cell-based seafood across multiple species as well as specific opportunities and challenges that exist for advancing this science. The authors find that the physiological properties of fish cell- and tissue- culture may be uniquely suited to cultivation in vitro. These physiological properties, including hypoxia tolerance, high buffering capacity, and low-temperature growth conditions, make marine cell culture an attractive opportunity for scale production of cell-based seafood; perhaps even more so than mammalian and avian cell cultures for cell-based meats. This, coupled with the unique capabilities of crustacean tissue-friendly scaffolding such as chitosan, a common seafood waste product and mushroom derivative, presents great promise for cell-based seafood production via bioreactor cultivation. To become fully realized, cell-based seafood research will require more understanding of fish muscle culture and cultivation; more investigation into serum-free media formulations optimized for fish cell culture; and bioreactor designs tuned to the needs of fish cells for large scale production.
ARTICLE | doi:10.20944/preprints201611.0001.v1
Subject: Materials Science, Polymers & Plastics Keywords: direct laser writing; ultrafast laser; 3D laser lithography; 3D printing; hybrid polymer; integrated microoptics; optical damage; photonics; pyrolysis; ceramic 3D structures
Online: 1 November 2016 (04:59:50 CET)
We introduce optically clear and resilient free-form micro-optical of pure (non-photosensitized) organic-inorganic SZ2080 material made by femtosecond 3D laser lithography (3DLL). This is advantageous for rapid printing of 3D micro-/nanooptics, including their integration directly onto optical fibers. A systematic study on the fabrication peculiarities and quality of resultant structures is performed. Comparison of microlenses’ resiliency to CW and femtosecond pulsed exposure is determined. Experimental results prove that pure SZ2080 is ∼3 fold more resistant to high irradiance as compared with a standard photo-sensitized material and can sustain up to 1.91 GW/cm2 intensity. 3DLL is a promising manufacturing approach for high-intensity micro-optics for emerging fields in astro-photonics and atto-second pulse generation. Additionally, pyrolysis is employed to shrink structures up to 40% by removing organic SZ2080 constituents. This opens a promising route towards downscaling photonic lattices and creation of mechanically robust glass-ceramic structures.
ARTICLE | doi:10.20944/preprints202104.0754.v1
Online: 28 April 2021 (15:34:49 CEST)
Path planning in 3D environment is a fundamental research area for robots and autonomous vehicles. Based on the principle ``the shortest path consists of tangents'', RimJump* is proposed as a tangent-based path planning method suitable for finding the shortest path (both off-ground and on-ground) in 3D space (e.g., octomap and point cloud) for mobile platform to follow. RimJump* searches the tangent graph in the form of a path tree and considers the geometrical properties of the locally shortest path. Therefore, the method can provide all of the locally shortest paths that connect the starting point and the target, including the globally shortest path. And the time cost of RimJump* is insensitive to map scale increases in comparison to methods that search the whole passable space rather than the surface of the obstacle, e.g., Dijkstra and A*. In the Results, RimJump* is compared with other methods in terms of path length and time cost.
ARTICLE | doi:10.20944/preprints201809.0490.v1
Online: 25 September 2018 (15:43:11 CEST)
Background: Melatonin is a potent mitochondrial, cytoprotective and antioxidant molecule with potentially strong anti-aging properties. Topical melatonin has shown to improve the clinical signs of skin aging. Melatosphere™ is a new lipid-based delivery system able to improve stability and skin penetration of melatonin when used in topical formulations. No clinical studies, using objective instrumental data, are available so far regarding the positive effect of Melatosphere™ in improving wrinkles in women with mild-to-moderate skin aging. Study Aim: We evaluate, in an open prospective, evaluator-blinded trial, the effects on skin texture of 2 months treatment with a Melatosphere™ based cream. Subjects and Methods: 15 women aged >45 years with mild to moderate facial skin aging (Glogau score ≥2) participated in the trial, after their informed consent. An ANTERA 3D computer-assisted skin analysis evaluation for the assessment of coarse and fine wrinkles of the periorbital area and melanin content was performed at baseline and after two months of treatment. An evaluator-blinded Investigator Global assessment of skin elastosis, roughness, level of dyscromia, skin dryness and presence of actinic damage was also performed at the same time points using a 4-grade score from 0 (no sign) to 3 (severe sign). Results: At baseline the mean (SD) IGA score was 8.2(1.0). After 2 months the IGA score significantly decrease to 4.2(1.4) (49% reduction) (P=0.0007). ANTERA 3D evaluations showed a significant reduction in skin coarse and fine wrinkles volume in the target area of -31% and -18%, respectively. Melanin content was reduced significantly by -17%. Conclusion: Topical melatonin carried in Melatosphere improves in the short-term signs of skin aging evaluated clinically and by ANTERA 3D device in women with mild to moderate skin aging.
COMMUNICATION | doi:10.20944/preprints201809.0071.v1
Online: 4 September 2018 (15:02:50 CEST)
We demonstrated a new approach to the production of three-dimensional-coated patterns using liquid route. Metallic perovskite oxides were coated onto three-dimensional (3D) microstructured substrates with different aspect ratios. The success of the method relies on the solution viscosity monitored by adding viscous liquid. The process of oxide thin films consists in three steps: preparing the precursor solution, coating the solution by spin-coating process onto three-dimensional-Si substrates and post-annealing. The chemical solution 3D-coating is conformal.
ARTICLE | doi:10.20944/preprints202108.0562.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: female reproductive tract; organoid; co-culture; crosstalk; blastocyst
Online: 31 August 2021 (11:19:56 CEST)
Hormones must be balanced and dynamically controlled for the Female Reproductive Tract (FRT) to function correctly during the menstrual cycle, pregnancy, and delivery. Gamete selection and successful transfer to the uterus, where it implants and pregnancy occurs, is supported by the mucosal epithelial lining of the FRT ovaries, uterus, cervix, fallopian tubes, and vagina. Successful implantation and placentation in humans and other animals rely on complex interactions between the embryo and a receptive female reproductive system. The FRT's recent breakthroughs in three-dimensional (3D) organoid systems now provide critical experimental models that match the organ's physiological, functional, and anatomical characteristics in vitro. This article summarizes the current state of the art on organoids generated from various parts of the FRT. The current analysis examines recent developments in the creation of organoid models of reproductive organs, as well as their future directions.
ARTICLE | doi:10.20944/preprints202107.0682.v1
Subject: Engineering, Automotive Engineering Keywords: fed-batch fermentation; kefir grains; probiotic culture; whey
Online: 30 July 2021 (09:12:13 CEST)
Nowadays, probiotics has been proposed for substituting antibiotics in animal feed, since the European Union (EU) banned the latter compounds in 2006 to avoid their serious side effects on human health. Therefore, this work aimed to produce a probiotic product by fed-fermentation of whey with kefir grains for use in animal feed. The whey was fermented with a combination of kefir grains AGK1 and the free biomass present in whole milk fermented milk used to activate these kefir grains. The probiotic culture obtained was characterized with high levels of biomass, total viability and antibacterial activity. Some probiotic properties of the probiotic culture were investigated in vitro, including its survival at low pH values, under simulated gastrointestinal conditions, after freezing in skim milk at − 20 ºC, and in the commercial feed during storage at room temperature. The viable cells of lactic and acetic acid bacteria and yeasts exhibited higher tolerance to acidic pH and simulated gastrointestinal conditions when the cells were protected with skim milk and piglet feed, compared with washed cells. The results indicated the feasibility of producing a probiotic product at a low cost with a potential application in animal feed.
COMMUNICATION | doi:10.20944/preprints202107.0601.v1
Subject: Life Sciences, Biochemistry Keywords: Malassezia; selective culture medium; Rapamycin; isolation; polymicrobial samples.
Online: 27 July 2021 (11:29:17 CEST)
Malassezia species are fastidious and slow-growing yeasts whose isolation from polymicrobial samples is hampered by fast-growing microorganisms. Malassezia selective culture media are needed because Malassezia are resistant to cycloheximide, but some fungi, including the chief human commensal Candida albicans resist to this compound. This study aimed to test whether the macrolide rapamycin could be used in combination with cycloheximide to develop a Malassezia-selective culture medium. Rapamycin susceptibility testing was performed via microdilution assays in modified Dixon against M. furfur and five Candida spp. The MIC was the lowest concentration producing 90% growth inhibition. Rapamycin medium ± cycloheximide 500 mg/L was also added to FastFung solid and yeast suspensions were inoculated and incubated for 72h. Rapamycin MICs against Candida spp. ranged from 0.5 to 2 mg/L, except for C. krusei whose MIC was >32 mg/L. M. furfur stains were rapamycin resistant. Rapamycin and cycloheximide supplementation of the FastFung medium effectively inhibited the growth of non-Malassezia yeast, including the cycloheximide-resistant C. albicans and C. tropicalis. Based on our findings, we recommend using this “MalaSelect” medium for Malassezia isolation and culture from polymicrobial samples.
ARTICLE | doi:10.20944/preprints202107.0444.v1
Subject: Biology, Anatomy & Morphology Keywords: cyanobacteria; Phormidium; culture growth; light; salinity; phycocyanin; pigments
Online: 20 July 2021 (11:35:05 CEST)
A strain of the filamentous non N-fixing cyanobacterium Phormidium sp. isolated from the Messolonghi (W. Greece) saltworks, was cultured in the laboratory at 6 different combinations of salinity (20-40-60 ppt) and illumination (low-2000 lux and high-8000 lux). At salinities of 60 and 40 ppt and in high illumination (XL-8000 lux) the growth rate (μmax) presented the highest values (0.491 and 0.401 respectively) compared to the corresponding at 20 ppt (0.203). In general and at all salinities, the higher illumination (XL) gave the highest growth rates and shorter dublication time (tg) in comparison to the lower illumination (L). On the contrary, phycocyanin, phycoerythrin and allophycocyanin production was extremely increased in the lower illumination (L) in all salinities, from ~14fold at 40 and 60 ppt to 269fold at 20 ppt of those corresponding to higher illumination (XL). Similar analogies were also recorded for the other two billiproteins. Chlorophyll-a content was also higher in lower illumination at all salinities in contrast to total carotenoids that did not exhibit such a pattern. The high growth rate and high phycocyanin content along with the rapid sedimentation of its cultured biomass can set this marine Phormidium species as a promising canditate for mass culture.
ARTICLE | doi:10.20944/preprints202011.0317.v1
Online: 10 November 2020 (13:54:41 CET)
Considered one of the finest first-generation Nigerian writers, John Pepper Clark-Bekederemo, who passed away on 13th October, 2020, had been categorised as a Eurocentric writer. This work assesses the authenticity or otherwise of this critics’ perception of Clark by critiquing his America, their America. By analysing this autobiography vis-à-vis the notion of self and other which is a theoretical concern in contemporary travel writing, it was established, among other things, that every culture has its dark sides which it must not feel too proud to change as time and situation demand; that Clark vehemently rejects the Americans’ claim of sophistication and superiority of their culture over African culture. The paper concludes that contemporary travel writing should be a rightful site for negotiating cultural, political and diplomatic compromises between the Self and the Other since the gulf may be difficult to close altogether.
ARTICLE | doi:10.20944/preprints202009.0124.v1
Online: 5 September 2020 (07:29:39 CEST)
Most commercial Cannabis sativa L. (cannabis) genotypes are short-day plants and cultivators typically use a 12.0 h uninterrupted dark period to induce flowering; however, scientific information is lacking to prove this is the optimal dark period for all genotypes, and cultivar specific photoperiods may increase productivity. Tissue culture can be used for research requiring multiple treatments, proper replication, and in a controlled environment on a smaller scale compared to greenhouse and indoor facilities. To determine whether cannabis explants can flower under varied photoperiods in vitro, explants were grown under one of six photoperiod treatments: 12.0, 13.2, 13.8, 14.4, 15.0, and 16.0 h for four weeks. The percentage of flowering explants was highest under 12.0 and 13.2 h treatments. There were no treatment effects on the fresh weight, final height, or growth index of the explants. The results suggest an uninterrupted dark period of at least 10.8 h (i.e. 13.2 h photoperiod) is needed to induce the flowering of this genotype. In vitro flowering could provide a unique and high throughput approach to study floral/seed development and secondary metabolism in cannabis under highly controlled conditions. Further research should determine if this response is the same on a whole plant level.
ARTICLE | doi:10.20944/preprints202008.0443.v1
Subject: Biology, Plant Sciences Keywords: cell suspension culture; anti-inflammatory activity; phytochemical analysis
Online: 20 August 2020 (07:44:18 CEST)
Many species of the Asteraceae family are used in traditional Mexican medicine for possessing healing properties. Ageratina pichinchensis (Asteraceae) is a plant used for the treatment of gastric ulcers, deep wounds and for its antifungal effects. The aim of this study was to establish a cell suspension culture of A. pichinchensis, quantify the anti-inflammatory constituents 2,3-dihydrobenzofuran and 3-epilupeol, to evaluate the anti-inflammatory potential of its extracts and perform a phytochemical analysis. Cell suspension cultures were established in MS culture medium supplemented with 30 g L-1 sucrose and 1.0 g L-1 α-naphthaleneacetic acid (NAA) plus 0.1 mg L-1 6-furfurylaminopurine (KIN). The ethyl acetate extracts of cell suspension cultures analyzed by GC revealed that the maximum production of compounds The anti-inflammatory activity of these extracts exhibited significant inhibition of NO production. Furthermore, the phytochemical study of EtOAc and MeOH extracts of the biomass on day 20 led to the identification of 17 known compounds. The structures of compounds were assigned by analysis of 1D and 2D NMR data and the remainder by GC-MS. This is the first report of the production of the (-)-Artemesinol, (-)-Artemesinol glucoside, Encecalin and 3,5-diprenyl-acetophenone compounds by a cell suspension cultures of A. pichinchensis.
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: female dog; cell culture; mammary cancer; veterinary; oncology
Online: 15 April 2020 (07:59:18 CEST)
Mammary neoplasm affects a population of intact and elderly female dogs and 50% are malignant. In order to study this disease, cell culture is as a promising preclinical model, creating the opportunity to deposit cell lines at a cell bank, allowing a great reproducibility of the assays and making the validation of the results more reliable. Another important aspect is the possibility to establish models for better understanding tumour characteristics, such as vasculogenic mimicry. Due the importance of cancer cell lines in preclinical models, this study aimed to establish and characterize primary cell lines from canine mammary gland tumours according to immunophenotype and tumorigenicity, and with its ability to form vasculogenic mimicry-like structures in vitro and in vivo. Cell cultures were evaluated for morphology, phenotype, vasculogenic mimicry and tumorigenicity abilities. We collected 17 primary mammary carcinoma and 3 metastasis and had a satisfactory result in 10 of them. All cell lines presented spindle shape or polygonal morphology and expressed concomitant pan-cytokeratin and cytokeratin 8/18. Four cell lines had vasculogenic mimicry ability in vitro and two of them showed in vivo tumorigenic potential and forming VM in the xenotransplant tumour. Cell characterization of those lines will help to create a database for more knowledge of mammary carcinomas in dogs, including studies of tumour behaviour and new therapeutic targets.
ARTICLE | doi:10.20944/preprints202002.0430.v2
Subject: Life Sciences, Biotechnology Keywords: Co-culture; Reduced-serum; Wound bed; Fibroblasts; Keratinocytes
Online: 12 March 2020 (13:24:46 CET)
Contact-based co-culture of fibroblasts and keratinocytes is important to study the structure and functions of the wound bed. Co-culture of these two cell types in direct contact with each other has been challenging, requiring high serum concentrations (up to 10%), feeder systems and a range of supplemental factors. These approaches are not only technically demanding, but also present scientific, cost and ethical limitations associated with high-serum concentrations. We have developed two reduced-serum approaches (1-2%) to support contact-based co-culture of human dermal fibroblasts (HDFa) and human epidermal keratinocytes (HaCaT). The two approaches include (1) Specialized cell culture media for each cell type mixed in a 1:1 ratio (KGM+FGM), and (2) Minimal media supplemented with cell-specific growth factors (MEM+GF). Co-culture could be successfully achieved by co-seeding (two cell types were introduced simultaneously), or in a layered fashion (keratinocytes seeded on top of confluent fibroblasts). With wound scratch assays, the co-cultured platforms could demonstrate cell proliferation, migration and wound closure. The reduced-serum conditions developed are simple, easy to formulate and adopt, and based on commonly-available media components. These contact-based co-culture approaches can be leveraged for wound and skin studies, and tissue bioengineering applications, potentially reducing concerns with high-serum formulations.
ARTICLE | doi:10.20944/preprints201904.0266.v1
Subject: Biology, Other Keywords: historical individuals, extended evolutionary synthesis, evolutionary innovation, culture
Online: 24 April 2019 (11:20:29 CEST)
Since its inception, evolutionary theory has experienced a number of extensions. The most important of these took the forms of the Modern Evolutionary Synthesis (MES), embracing genetics and population biology in the early 20th century, and the Extended Evolutionary Synthesis (EES) of the last thirty years, embracing, among other factors, non-genetic forms of inheritance. While we appreciate the motivation for this recent extension, we argue that it does not go far enough, since it restricts itself to widening explanations of adaptation by adding mechanisms of inheritance and variation. A more thoroughgoing extension is needed, one that widens the explanatory scope of evolutionary theory. In addition to adaptation and its various mechanisms, evolutionary theory must recognize as a distinct intellectual challenge the origin of what we call “historical kinds.” Under historical kinds we include any process that acquires a quasi-independent and traceable lineage-history in biological and cultural evolution. We develop the notion of a historical kind in a series of paradigmatic exemplars, from genes and homologues to rituals and music, and we propose a preliminary characterization.
ARTICLE | doi:10.20944/preprints201903.0073.v1
Subject: Keywords: coffee culture, domestication, creolization, encapsulation, and middle class
Online: 6 March 2019 (10:48:50 CET)
This article is an anthropology study on how western-style coffee culture influences Indonesian coffee culture and eventually develops a new localized coffee culture. Immense development of such worldwide coffee franchise as Starbucks affects local community's coffee culture, particularly the middle class. This new wave is considered as an alternative lifestyle for those who are consumptive and seeking for leisure, dynamics, and identity. Broader than just the process of domestication or creolization, Indonesian new coffee culture has an element of “soft countering to” western coffee culture even though it still embraces some parts of the western styles. This phenomenon is referred to by the writer as the cultural encapsulation process or the process of substantial cultural resistance by drawing a line between the two coffee cultures with the intention of taking merely compatible elements.
ARTICLE | doi:10.20944/preprints201811.0487.v1
Subject: Social Sciences, Sociology Keywords: Innovative talents; Innovation system; Innovation culture; Innovation environment
Online: 20 November 2018 (08:30:39 CET)
Based on the deployment of global innovation value chain, the article analyzes the existing independent innovation capability of Guangzhou, and analyzes in detail from innovative talents, innovation system, innovation culture and innovation environment. The role of the central city of Guangzhou has led to research on issues such as the common development of cities in Guangdong and the Pearl River Delta. Using the combination of qualitative analysis and quantitative analysis, we can find out the shortcomings of Guangzhou's independent innovation capability, explore the causes of problems, and seek solutions to the main problems.
ARTICLE | doi:10.20944/preprints201809.0108.v1
Subject: Biology, Horticulture Keywords: aeroponics; soilless culture; root growth; root/shoot ratio
Online: 6 September 2018 (04:20:00 CEST)
Aeroponics is a relatively new soilless culture technology, which may produce food in space limited cities or non-arable land with high water use efficiency. The shoot and root growth, root characteristics, mineral contents of two lettuce cultivars were measured in aeroponics, as compared with hydroponics and substrate culture. The results showed that aeroponics remarkably improved the root growth with a significant greater root biomass, root/shoot ratio, and several times higher total root length, root area and root volume. However, the greater root growth did not lead to a better shoot growth compared with hydroponics, due to the limited availability of nutrients and water. It can be concluded that aeroponics systems may be better for high value true root crops production. Further research is necessary to figure out the suitable pressure, droplet size, and misting interval in order to improve the continuously availability of nutrients and water in aeroponics, if it is used to grow crops like lettuce for harvesting above-ground parts.
REVIEW | doi:10.20944/preprints201806.0081.v1
Subject: Social Sciences, Business And Administrative Sciences Keywords: empowerment; innovation culture; inclusive leadership; innovation capacity; school
Online: 6 June 2018 (10:07:23 CEST)
This paper has two objectives: the first, to analyze the mediating effect of teacher empowerment between innovation culture and innovation capacity, and between inclusive leadership and innovation capacity; the second, to analyze the moderating effects of the school context on the innovation capacity. Data were collected in a representative sample of secondary schools in Valencia, Spain. The research model adopted is structural equation modeling, using the partial least squares (PLS) technique. The model has confirmed that teacher empowerment mediates between innovation culture and innovation capacity and between inclusive leadership and the innovation capacity. It is found that the educational context does not moderate the relationships in the proposed analysis model. This paper emphasizes the role of teacher empowerment in educational innovation and extends the knowledge of culture and leadership in the school organization.
ARTICLE | doi:10.20944/preprints201701.0137.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: cell culture; bioreactor; live cell imaging; tissue engineering
Online: 31 January 2017 (12:39:46 CET)
Here, we present a staged approach for an innovative repurposing of a portable infant humidicrib into a live cell growth, observation, and imaging system. Furthmore, humidicrib can support different variations of “umbilical” bioreactors, and can be used to conduct electrophysiology experiments and in situ immunohistochemistry. Modifications incorporate a closed loop carbon dioxide (CO2) concentration control system with umbilical CO2 and heating support for tailored bioreactors. The repurposing cost is inexpensive and allows for the continued observation and imaging of cells. This prototype unit has been used to continuously observe and image live primary neurons for up to 21 days. This demonstrates the repurposed units’ suitability for use in tissue culture based research, particularly where modifications to microscopes are required or where sensitive manipulation outside of a standard incubator is needed.
ARTICLE | doi:10.20944/preprints201611.0122.v1
Subject: Social Sciences, Business And Administrative Sciences Keywords: green innovation; green organizational culture; sustainability; sustainability drivers
Online: 24 November 2016 (11:09:23 CET)
This study aims to examine Turkish companies from a sustainability and green innovation point of view. Through this purpose, this research’s objective is to find out relationship between sustainability drivers and green innovation and also to search for green organizational culture’s mediation effect in this relationship. Survey was carried in companies operating in Turkey which were listed among İstanbul Chamber of Industry (ICI) Top 500 companies for last 3 years successively and have ISO14001 Environmental Management Certificate. According to the survey results, it was manifested that factors directing companies to sustainability having a positive relationship with green organizational culture and green innovation. It is found that there is a partial mediation effect of green organizational culture between motivating factors for sustainability and green innovation.
ARTICLE | doi:10.20944/preprints201812.0120.v1
Subject: Engineering, Civil Engineering Keywords: Terrestrial photogrammetry, 3D reconstruction, Low-cost technology, 3D model, bundle adjustment, Agisoft PhotoScan, C2C
Online: 11 December 2018 (09:35:32 CET)
This paper analyses and evaluate the precision and the accuracy the capability of low-cost terrestrial photogrammetry by using many digital cameras to construct a 3D model of an object. To obtain the goal, a building façade has imaged by two inexpensive digital cameras such as Canon and Pentax camera. Bundle adjustment and image processing calculated by using Agisoft PhotScan software. Several factors will be included during this study, different cameras, and control points. Many photogrammetric point clouds will be generated. Their accuracy will be compared with some natural control points which collected by the laser total station of the same building. The cloud to cloud distance will be computed for different comparison 3D models to investigate different variables. The practical field experiment showed a spatial positioning reported by the investigated technique was between 2-4cm in the 3D coordinates of a façade. This accuracy is optimistic since the captured images were processed without any control points.
COMMUNICATION | doi:10.20944/preprints201710.0041.v3
Subject: Social Sciences, Business And Administrative Sciences Keywords: uncertainty management; risk management; safety; ISO 31000:2009; ISO 31010:2009; risk management framework; risk-sentience; safety culture; risk culture; enterprise risk management
Online: 19 June 2018 (12:58:28 CEST)
The aim of this study was to develop, implement, and evaluate a new auxiliary enterprise risk management framework and process to serve as an enabler to the global ISO 31000 risk framework and ISO 31010 processes. This framework has been designed particularly for use within high-risk environments and those characterized by volatility, uncertainty, complexity, and ambiguity (VUCA). This paper proposes a methodology for optimization of structured sharing and grass-roots management of all available risk-sentience information with the assessed potential to develop into an identifiable risk in the future. The author introduces new risk terminology including risk-sentience, risk-sentience information, and risk-sentience management. The process involved the development of the Theory of Risk-Sentience (ToRS), Risk-Sentience Auxiliary Framework (RSAF) and a risk-sentience management process referred to as LUOMEAR (Learning from Uncertainties, Others Mistakes, Experiences and Anecdotal Reporting). Manchester Patient Safety Framework (MaPSaF), SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis, and a newly developed Risk-Sentience Fertility Checklist were used to conduct pre and post-trial evaluations. The findings include positive adjustments in safety culture, components of commitment to quality, communication and team-working around safety issues, access to evolving risk-information, and efficient sharing and management of recorded risk-information. Recommendations are made for more extensive application of both the proposed auxiliary risk framework and process within high-risk sectors to further explore its effectiveness and scope.
ARTICLE | doi:10.20944/preprints201809.0412.v1
Subject: Physical Sciences, Applied Physics Keywords: Additive-Manufacturing, 3D Printing, Glass-Ceramics, Nanoscale, Laser 3D lithography, SZ2080, Cristobalite, Zirconia, Nanocomposites, Calcination
Online: 20 September 2018 (13:52:10 CEST)
Fabrication of a true-3D inorganic ceramic with resolution down to nanoscale using sol-gel resist precursor is demonstrated. The method has an unrestricted free-form capability, control of the fill-factor, and high fabrication throughput. A systematic study of the proposed approach based on ultrafast laser 3D lithography of organic-inorganic hybrid sol-gel resin followed by a heat treatment enabled formation of inorganic amorphous and crystalline composites guided by the composition of the initial resin. The achieved resolution of 100 nm was obtained for 3D patterns of complex free-form architectures. Fabrication throughput of 50×103 voxels/s is achieved; voxel - a single volume element was recorded by a single pulse exposure. After a subsequent thermal treatment, ceramic phase was formed depending on the temperature and duration of the heat treatment as validated by Raman micro-spectroscopy. The X-ray diffraction (XRD) revealed a gradual emergence of the crystalline phases at higher temperatures with a signature of cristobalite SiO2, a high-temperature polymorph. Also, the tetragonal ZrO2 phase known for its high fracture strength was observed. This 3D nano-sintering technique is scalable from nano- to millimeter dimensions and opens a conceptually novel route for optical 3D nano-printing of various crystalline inorganic materials defined by an initial composition for diverse applications for microdevices in harsh physical and chemical environments and high temperatures.
ARTICLE | doi:10.20944/preprints202208.0497.v1
Subject: Life Sciences, Biochemistry Keywords: oxygen; physioxia; hyperoxia; cell culture; transcriptomics; differential gene expression
Online: 29 August 2022 (14:46:44 CEST)
Standard cell culture is routinely performed at supraphysiological oxygen concentrations (~18% O2). Conversely, oxygen levels in most tissues range from 1%–6% (physioxia). Such hyperoxic conditions can alter reactive oxygen species (ROS) production, energy metabolism, mitochondrial network dynamics, and response to drugs and hormones. The aim of this project was to investigate the transcriptional response to different oxygen levels and whether it is similar across cell lines, or cell-line specific. Using RNA-seq, we performed differential gene expression and functional enrichment analyses in four human cancer cell lines, LNCaP, Huh-7, PC-3, and SH-SY5Y cultured at either 5% or 18% oxygen for 14 days. We found that oxygen levels affected transcript abundance of hundreds of genes, with the affected genes having little overlap between cell lines. Functional enrichment analysis also revealed different processes and pathways being affected in each cell line. Interestingly, we found that the top differentially expressed genes are involved in cancer biology. Further, we observed several hypoxia-inducible factor (HIF) targets upregulated at 5% oxygen, suggesting a role of HIF at physiological oxygen conditions. Finally, oxygen strongly induced transcription of mitochondrial genes in most cell lines, in a cell-type specific manner too. We conclude that cellular response to oxygen is widely cell-type specific, emphasizing the importance of maintaining physioxia in cell culture.
REVIEW | doi:10.20944/preprints202206.0072.v1
Subject: Life Sciences, Biotechnology Keywords: bamboo; tissue culture; growth regulators; hardening; carbon sequestration; climate
Online: 6 June 2022 (08:51:25 CEST)
Objectives: The promising specific growth regulators are employed tissue culture of the bamboo species. The specific natural hardening mixture supports the acclimatization and adaptation of the protected cultivation. The bamboo species contribute to the carbon sequestration and stabilization of the environment. Findings: The growth regulator 2, 4-D encourages callus induction and growth regulators NAA + TDZ, BAP + Kinetin + Gelrite, BAP + Kinetin + Coconut water + myo-inositol, NAA and TDZ impose plant regeneration in the Bambusa species. The growth regulator of 2,4-D, 2,4-D + Kinetin, 2,4-D + BA, 2,4-D + BAP and 2,4-D + NAA + BAP produces callus induction in the Dendrocalamus species. The growth regulator of TDZ, BA and IBA + Coumarin + Putrescine, BAP + GA3, NAA + Kinetin, BA + IBA, BA + Kinetin + NAA, NAA + Kinetin, Kinetin + IAA has facilitated shoot regeneration in the Dendrocalamus species with the specific period. The growth regulator of BA and TDZ; BAP + TDZ, IBA + Coumarin + Putrescine, BAP + GA3, NAA + Kinetin, BA + IBA, BA + Kinetin + NAA, NAA + Kinetin, Kinetin + IAA develops root regeneration with unambiguous time in the Dendrocalamus species. The growth regulator of BAP and Kinetin + BAP imposes shoot regeneration and IBA and IBA + Coumarin + sucrose conducts root regeneration in the edible bamboo. The natural hardening materials of cocopeat, vermicompost, perlite, cow dung, FYM, compost, soil & garden soil and humus soil, perlite, and FYM recommend in the acclimatization and adaptation of the Bambusa species and Dendrocalamus species respectively. Novelty: The standard growth regulators and hardening mixtures impose tissue culture, acclimatization and adaptation in the bamboo species. The bamboo species involves in managing carbon sequestration, biogeochemical cycle and the environment.
ARTICLE | doi:10.20944/preprints202203.0334.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Nutrition; Hydration; Dementia: Eating; Drinking; Food; Ethnic minorities; Culture
Online: 25 March 2022 (02:47:59 CET)
Eating and drinking difficulties are common in dementia, but little is known about the experiences of ethnic minority groups managing these difficulties at home. We undertook qualitative semi-structured interviews, exploring the meaning of food, the impact of dementia on eating and drinking and carers’ experiences of support. Interviews were audio-recorded and transcribed verbatim. We interviewed 17 carers and people with dementia from ethnic minority backgrounds, using reflexive thematic analysis to analyse data. Food/drink had strong links to identity, culture and emotions. Providing culturally familiar foods, celebrating traditional festivals and supporting previous food-related roles promoted reminiscence, which encouraged people with dementia to eat and drink, as did social interactions. However, these strategies sometimes led to distress in those with more advanced dementia. Food choices were also influenced by carer strain, generational differences and the impact of health conditions. Despite a strong sense of duty to care for relatives at home, there was low awareness of community support services. Carers expressed a need for culturally tailored support for managing dementia-related eating and drinking difficulties at home. Healthcare professionals must provide contextually relevant advice to carers, being mindful of how cultural backgrounds can affect dietary choices.
COMMUNICATION | doi:10.20944/preprints202203.0162.v1
Subject: Medicine & Pharmacology, Other Keywords: Mucorales; pulmonary mucormycosis; hematologic malignancy; transplantation; fungal culture; histopathology
Online: 11 March 2022 (07:59:01 CET)
Cultural recovery of Mucorales from hyphae-laden tissue is poor, and the clinical implications of culture positivity are scarcely studied. Therefore, we compared clinical and histological characteristics of culture-positive and culture-negative histology-proven pulmonary mucormycosis cases among cancer patients. Histology specimens were blindly reviewed by a Thoracic Pathologist and graded on four histopathologic features: hyphal quantity, tissue necrosis, tissue invasion, and vascular invasion. Twenty cases with a corresponding fungal culture were identified; five were culture-positive, and 15 culture-negative. Although no statistically significant differences were found, culture-positive patients were more likely to exhibit a high burden of necrosis and have a high burden of hyphae but tended to have less vascular invasion than culture-negative patients. In terms of clinical characteristics, culture-positive patients were more likely to have acute myeloid leukemia (60% vs. 27%, p=0.19), a history of hematopoietic cell transplant (80% vs. 53%, p=0.31), severe lymphopenia (absolute lymphocyte count ≤500/µL, 100% vs. 73%, p=0.36), and monocytopenia (absolute monocyte count ≤100/µL, 60% vs. 20%, p=0.11). Forty-two-day all-cause mortality was comparable between culture-positive and culture-negative patients (60% and 53%, p=0.80). This pilot study represents the first comprehensive histopathological scoring method to examine the relationship between histopathologic features, culture positivity, and clinical features of pulmonary mucormycosis.
ARTICLE | doi:10.20944/preprints202112.0355.v1
Subject: Biology, Forestry Keywords: dark treatment; hybrid poplar; plant hormone; rooting; shoot culture
Online: 22 December 2021 (11:46:18 CET)
Phenotypic plasticity in response to adverse conditions determines plant productivity and survival. The aim of this study was to test if two highly productive Populus genotypes, characterized by different in vitro etiolation patterns, differ also in their responses to hormones gibberellin (GA) and abscisic acid (ABA), and to a GA biosynthesis inhibitor paclobutrazol (PBZ). The experiments on shoot cultures of ‘Hybrida 275’ (abbr. H275; Populus maximowiczii × P. trichocarpa) and IBL 91/78 (Populus tremula × P. alba) were conducted either by modulating the physical in vitro environment or by adding specific chemicals to the nutrient medium. Our results show that there are significant differences between the studied genotypes in environmental and hormonal regulation of growth responses. The genotype H275, which responded to darkness with PBZ-inhibitable shoot elongation, was unable to recover its growth after treatment with ABA. In contrast, the genotype IBL 91/78, whose shoot elongation was not affected either by darkness or PBZ treatment, recovered so well after the ABA treatment that, when rooted subsequently, it developed longer shoots and roots than without ABA treatment. Our results indicate that GA catabolism and repressive signaling provide an important pathway to control growth and physiological adaptation in response to immediate or impending adverse conditions. These observations can help breeders define robust criteria for identifying genotypes with high resistance and productivity and highlight where genotypes exhibit susceptibility to stress.
ARTICLE | doi:10.20944/preprints202107.0192.v1
Subject: Social Sciences, Accounting Keywords: errors; culture; quality improvement; patient safety; management; clinics; outpatient
Online: 8 July 2021 (10:44:33 CEST)
As many as 20-25% of the population experiences harm in outpatient settings, yet these locations are underrepresented in the literature compared to hospitals. We examined results from the Medical Office Survey on Patient Safety Culture designed by the Agency for Healthcare Research and Quality. The survey administered in 2012 gathered perceptions from 23,679 individuals in 934 unique medical offices. We examined associations of organizational patient safety climate composites on frequency of safety and quality issues, overall quality score, and safety rating. We found organizational patient safety composites are all positively and significantly associated with a higher overall quality score and patient safety rating, and fewer safety and quality issues. Office processes and standardization appeared to have the most consistent influence on perceived quality outcomes. Our results indicate it may be advantageous for medical offices to improve on the factors that contribute to positive safety climate.
ARTICLE | doi:10.20944/preprints202107.0175.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: Catholic education; Catholic schools; Religious Education; de-traditionalised culture
Online: 7 July 2021 (10:37:19 CEST)
Philip Phenix’s (1964) book Realms of meaning started the ever growing movement concerned with how school education might help young people in their search for meaning in times of rapid social change. Today, in globalised, digital, secularised, de-traditionalised culture, the importance and urgency of this role have never been greater. Cultural change has accelerated exponentially, and for many – including students in religious/Catholic schools – traditional religious sources of meaning are no longer prominent or plausible reference points. Catholic schools, whether independent or semi-state institutions because of government funding, can make a valuable contribution young people’s spiritual/moral education, no matter what their level of religious affiliation or practice. This article argues that such a contribution requires change to the discourse or narrative of Catholic school Religious Education, with corresponding adjustments to content and pedagogy. Its present trajectory, which is excessively concerned with promoting a Catholic identity in students, needs to be modified. Both the religious and non-religious students, especially in the senior classes, would derive greater spiritual and religious benefit from the inclusion of more life-relevant and issue-related content, together with a critical, research-oriented pedagogy. Such an approach proposes that the Catholic Church’s schools should offer unconditionally a meaningful spiritual/moral education that is relevant to all students, rather than a traditional one which seemed to presume that all students are, or should be practising Catholics. This does not minimise attention to the Catholic tradition, but it allows for a study of how people negotiate the task of constructing meaning and values in a complex culture. The article also looks at the ‘headwinds’ that hinder the implementation of this approach. The article is focused specifically on the Australian context where Catholic schools are semi-state institutions because they are funded by both state and federal governments. The issues are still likely to be pertinent to Catholic education in other countries, while taking into account significant contextual differences.
BRIEF REPORT | doi:10.20944/preprints202104.0658.v1
Subject: Life Sciences, Biochemistry Keywords: Candida; Candida auris; Culture; Emerging fungus; Isolation; Specific medium
Online: 26 April 2021 (11:06:41 CEST)
Candida auris is an emerging multidrug resistant yeast causing nosocomial infections and associated with high mortality in immunocompromised patients. Rapid identification and characterisation is necessary for its diagnosis and containing spread. In this study, we present a selective culture medium for all C. auris clades. This medium is sensitive with a limit of detection of 102 CFU/ml. The 100% specificity of SCA (Specific C. auris) medium is confirmed on a set of 134 Candida strains, 50 bacterial species and 200 human stool samples. Thus, this medium specifically selects for C. auris isolation from clinical samples, and allows studying its phenotypic profile.
ARTICLE | doi:10.20944/preprints201911.0251.v1
Subject: Life Sciences, Biotechnology Keywords: endophyte; Trichoderma; fatty acid; antifeedant, myzus persicae; culture media
Online: 21 November 2019 (15:00:33 CET)
Increasing pesticide resistance in plant pathogens is major concern in agriculture production. Research on ecofriendly alternatives of chemical pesticides are more in demand in pesticide industry. In the current study, an ethyl acetate extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica). The bioactive components have been characterized following a bioassay-guided isolation against M. persicae. The chemical study of this bioactive extract resulted in the isolation of 1-oleoyl-2-linoleoyl-3-palmitoylglycerol (1), eburicol (2), (24R)-stigmast-4-ene-3-one or β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in compound 1 (oleic, linoleic and palmitic) showed strong dose-dependent aphid antifeedant effects against M. persicae. Liquid (PDB, and SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae with sorghum being the most active. Corn increased the content in linolenic, pearl millet the oleic and stearic and sorghum oleic and linolenic acids compared to rice. Their antifeedant effects correlated with linoleic /oleic acids. The phytotoxic effects of these extracts against Lolium perenne and Lactuca sativa varied with culture media, with sorghum being the least toxic.
ARTICLE | doi:10.20944/preprints201911.0108.v1
Subject: Earth Sciences, Environmental Sciences Keywords: microalgae; cyanobacteria; biomass composition; culture optimization; growth on wastewaters
Online: 10 November 2019 (10:56:59 CET)
The purpose of this work is to define optimal growth conditions for batch culture of the cyanobacterium Arthrospira maxima and the microalgae Chlorella vulgaris, Isochrysis galbana and Nannochloropsis gaditana. Thus, we study the effect of three variables on algae growth: i.e., inoculum:culture medium ratio, light:darkness photoperiod and type of culture medium, including both synthetic media and wastewaters. The results showed that the initial inoculum volume did not affect the amount of biomass at the end of the growth (14 days), whereas an excess (18 h) or defect (6 h) in the number of hours of light is determinant for its development. The contribution of nutrients from different culture media modified the growth of the different species. A. maxima was favoured in seawater enriched with Guillard's F/2 as well as C. vulgaris and N. gaditana but in fresh water medium. I. galbana had the greatest growth in the marine environment enriched with Walne’s media. Nitrate was the limiting growth reagent at the end of the exponential phase of growth for C. vulgaris and N. gaditana, while iron was for A. maxima and I. galbana. All species demonstrated their capability to grow in effluents from a wastewater treatment plant and they efficiently consume nitrogen, especially the three microalgae species.
ARTICLE | doi:10.20944/preprints201906.0009.v1
Subject: Social Sciences, Law Keywords: entrepreneurial culture, persistence, innovation capability, patent, high-tech industry
Online: 3 June 2019 (08:51:32 CEST)
Currently the rapid growth of global economy has the competition among high-tech industries develop from regional to global, and the competition becomes fierce. In face of such fierce competition in global high-tech industry, it is realized that tangible assets could no longer be the differentiation basis, but intangible assets are regarded as the differentiation capital. An enterprise with sustainable innovation would dominate the world market and enhance the international competitiveness of domestic economy. When internal entrepreneurial culture is prevalent, an enterprise would naturally promote the innovation capability. Such a point of view also explains more popular of the innovative products or services of some enterprises than those with larger scales. Aiming at employees in high-tech industry in Guanxi Province, total 500 copies of questionnaire are randomly distributed, and 337 valid copies are retrieved, with the retrieval rate 67%. The research results reveal significantly positive correlations between 1.entrepreneurial culture and sustainable innovation capability, 2.sustainable innovation capability and patent, and 3.entrepreneurial culture and patent. According to the results, suggestions are proposed, expecting to explain how a high-tech business outperforms in the changeable digital era and acquires the sustainable innovation capability and patent to grasp the opportunity.
ARTICLE | doi:10.20944/preprints201809.0508.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Moringa oleifera L., antioxidant activity, cell culture, irritant potential
Online: 26 September 2018 (13:16:14 CEST)
Extracts obtained from leaves of Moringa tree (Moringa oleifera) are a rich source of many bioactive compounds: flavonoids, phenolic acids or carotenoids. It also contains such components as, vitamins (A, C, niacin, pantothenic acid), alkaloids, tannins or saponins. Extracts and plant substances derived from the leaves of Moringa oleifera L. have a strong antioxidant, toning and anti-inflammatory effect. The work attempts to obtain a multifunctional plant extract derived from Moringa tree leaves. Obtained extracts was analyzed for their biochemical and physicochemical properties. The obtained results indicate on a strong antioxidative potential of the tested extracts. The further step was an attempt to apply the extracts in the model body wash cosmetic. The biological activity of extracts and model cosmetic formulation were assayed by in vitro analysis on two human cell lines: keratinocytes (HaCat,) and fibroblasts (BJ). The results showed that the tested extracts may affect on increasing of cell proliferation and reduce oxidative stress in cells. The addition of the tested extracts to the model cosmetic formulation, were contributed to the reduction of their ability to irritate the skin and improve the safety of use of the product.
ARTICLE | doi:10.20944/preprints201805.0367.v1
Subject: Earth Sciences, Environmental Sciences Keywords: vulnerability; culture; religion; agency; adaptation; perceptions; climate change; dependency
Online: 25 May 2018 (12:06:03 CEST)
Semi-arid Namibia is marginal for agricultural production. Low soil fertility combined with low and variable rainfall restrict the livelihoods of smallholder farmers who often struggle to produce enough food. Although historically communities have adopted a number of coping mechanisms, climate change threatens to further reduce agricultural production. There are many additional options available to smallholder farmers to adapt to climate change, but they are not necessarily adopting these measures despite having noticed increasing temperatures and declining rainfall. Semi-structured interviews were conducted in three villages in Onesi constituency to examine what agricultural practices smallholder crop farmers use, perception of changes in their yields, their perspective on future yields and whether they are planning on changing their agricultural practices. The results suggest that to sustain the livelihoods of rural communities in north-central Namibia support is needed from local and regional authorities, as well as traditional and religious leaders to assist with enhancing access to information, enabling information sharing on adaptation options, and increasing awareness on climate change, it’s impacts and what can be done about it. In addition to this the implementation of adaptation action also requires demonstration sites and building capacity to enable the development of self-help groups.
ARTICLE | doi:10.20944/preprints201801.0226.v1
Subject: Social Sciences, Sociology Keywords: religion; culture; politics; differentiation; historical process; Western European countries
Online: 24 January 2018 (10:27:11 CET)
The societies of Western Europe, following the territorial delimitation of the corresponding State, have gone through different historical processes of internal homogenization. After the Peace of Westphalia (1648) the application of the principle cuius regio eius religio induced the religious homogenization of the population. Then, due to the ethnic diversity of its population, the State tried to homogenize it from the cultural point of view; it was the process of nationalization and democratization of the State. This process lead to the separation of religion from politics and from culture. After the two world wars, national reconstruction needed a foreign population: this need for labor was filled in the most developed countries by population of the countries that were least (Portuguese, Spanish, Italian ...) and also by population flows coming from the old colonies. The cultural and religious homogeneity of these countries began to lose force. With the oil crisis of the 1970s, a period of major economic fluctuations began in Europe. In those years, the second generation of the population of immigrant origin began to go to a job market that was not in good health. The religion and culture of their predecessors became autonomous resources for the reconstruction of their identity and to achieve a personal and social esteem. This process is necessarily leading States to rethink the relations between politics, culture and religion.
ARTICLE | doi:10.20944/preprints201710.0044.v1
Subject: Social Sciences, Organizational Economics & Management Keywords: systems theory; economic systems; social structure; competition; strategy; culture
Online: 9 October 2017 (05:27:13 CEST)
This theoretical article reviews the model describing processes in social systems based on the analysis of their resource base. Application of the system theory can help to explain why some systems are aimed at prevention of type I errors, while other seek to decrease quantity of type II errors. Such differences are manifested in investment of resources either into deep interaction or into wide coverage. Some examples of such strategies in economic, market and production systems are provided in the article. The article introduces some provisions of the system theory in the context of the resource flows. The main indicators that are considered in this article are the characteristics of the sources of the exchanging flows of resources. Their relative frequency and quality are investigated, on the basis of which the most effective strategy of the system is derived, as a mechanism for redistributing resources. The rigor of the system's strategy depends on the magnitude of the difference in characteristics. It is explained how exactly it influences the exchange processes, that in reality systems do not interact simultaneously, and one of the opposite resource flows is always delayed. It is shown how the system strategy depends on the risks linked with interactions. Also, there are grounds for the need to accumulate resources, including in the situation of their surplus. The model helps also explain shift of economic centers throughout history. Additionally, there is an analogy between systems strategies and the competitive strategies described by M. Porter, and outsourcing versus integration.
REVIEW | doi:10.20944/preprints202111.0228.v1
Subject: Engineering, Control & Systems Engineering Keywords: Deep Learning; 3D Instance Segmentation; Datasets
Online: 12 November 2021 (14:56:14 CET)
Beyond semantic segmentation,3D instance segmentation(a process to delineate objects of interest and also classifying the objects into a set of categories) is gaining more and more interest among researchers since numerous computer vision applications need accurate segmentation processes(autonomous driving, indoor navigation, and even virtual or augmented reality systems…) This paper gives an overview and a technical comparison of the existing deep learning architectures in handling unstructured Euclidean data for the rapidly developing 3D instance segmentation. First, the authors divide the 3D point clouds based instance segmentation techniques into two major categories which are proposal based methods and proposal free methods. Then, they also introduce and compare the most used datasets with regard to 3D instance segmentation. Furthermore, they compare and analyze these techniques performance (speed, accuracy, response to noise…). Finally, this paper provides a review of the possible future directions of deep learning for 3D sensor-based information and provides insight into the most promising areas for prospective research.
ARTICLE | doi:10.20944/preprints201811.0437.v1
Subject: Materials Science, Nanotechnology Keywords: graphene; polystyrene; 3D graphene sponges; electrochemistry
Online: 19 November 2018 (09:39:17 CET)
Polystyrene as a thin film on arbitrary substrates or pellets form defective graphene films or powders that can be dispersed in water and organic solvents. The materials were characterized by visible absorption, Raman and X-ray photoelectron spectroscopy, electron and atomic force microscopy and electrochemistry. Raman spectra of these materials show the presence of the expected 2D, G and D peaks at 2750, 1590 and 1350 cm-1, respectively. The relative intensity of the G vs. the D peak is taken as a quantitative indicator of the density of defects in the G layer.
ARTICLE | doi:10.20944/preprints201810.0269.v1
Subject: Life Sciences, Cell & Developmental Biology Keywords: 3D models; cartilage; chondrocytes; osteoarthritis (OA)
Online: 12 October 2018 (12:19:01 CEST)
Osteoarthritis (OA) is a joint disease involving cartilage degeneration. This study aimed to compare properties of chondrocytes from less-affected (LA-Cartilage) and severely-affected (SA-Cartilage) of human OA articular cartilage. Based on Dougados classification, OA cartilage was classified into two groups; less-affected (Grade 0–1) and severely-affected (Grade 2–3). Chondrocytes from each group were cultured until passage (P) 4. Growth, migration, stem cell properties and chondrogenic properties under normal and inflammatory conditions, and the formation of in vitro 3D cartilage tissues were compared between groups. The growth and migratory properties of LA-chondrocytes and SA-chondrocytes were similar, except that the migration rate of SA-chondrocytes was significantly higher at P0 compared to LA-chondrocytes. Both LA-chondrocytes and SA-chondrocytes expressed mesenchymal stem cell markers and tri-lineage differentiation, but the expression of stem cell markers decreased significantly with increasing passage number. Exposure to inflammatory conditions induced distinct morphological changes and significant increases in expression of SOX9 at P4 and MMP3 at P1 for LA-chondrocytes. LA-chondrocytes and SA-chondrocytes able to develop into in vitro 3D constructs, but SA-chondrocytes exhibited superior cartilage-like properties. Chondrocytes from both less- and severely-affected regions are suitable to be used in clinical applications, however, chondrocytes from severely-affected regions could be a more favorable cell source.
ARTICLE | doi:10.20944/preprints201801.0293.v1
Online: 1 February 2018 (14:37:58 CET)
Numerical weather prediction is an initial-value problem, for determination of the initial conditions, there are many methods and one of the most classical methods is variational methods in three dimensions, or 3D-Var. In this approach, with a defined cost function proportional to the square of the distance between the analysis and both the background and the observations, one can obtain the analysis. In the cost function, the background and the observations are reshaped to vectors; within this step, the order of the background error covariance matrix and the observational error covariance matrix becomes huge, which is not convenient to one to obtain the analysis. In this paper, according to the matrix analysis approach, we put forward some possible improvements to the dimension-reduction algorithm of 3D-Var, so that provide some references for data assimilation.
ARTICLE | doi:10.20944/preprints202109.0112.v1
Subject: Engineering, Marine Engineering Keywords: 3D point Cloud Classification, 3D point Cloud Shape Completion,Auto-Encoders, Contrastive Learning, Self-Supervised Learning
Online: 6 September 2021 (18:00:28 CEST)
In this paper, we present the idea of Self Supervised learning on the Shape Completion and Classification of point clouds. Most 3D shape completion pipelines utilize autoencoders to extract features from point clouds used in downstream tasks such as Classification, Segmentation, Detection, and other related applications. Our idea is to add Contrastive Learning into Auto-Encoders to learn both global and local feature representations of point clouds. We use a combination of Triplet Loss and Chamfer distance to learn global and local feature representations. To evaluate the performance of embeddings for Classification, we utilize the PointNet classifier. We also extend the number of classes to evaluate our model from 4 to 10 to show the generalization ability of learned features. Based on our results, embedding generated from the Contrastive autoencoder enhances Shape Completion and Classification performance from 84.2% to 84.9% of point clouds achieving the state-of-the-art results with 10 classes.
ARTICLE | doi:10.20944/preprints202201.0288.v1
Subject: Earth Sciences, Geoinformatics Keywords: MV/LV network; GIS planning; Spatial network analysis; 3D virtual city; Web and 3D Web GIS applications
Online: 20 January 2022 (08:32:37 CET)
Electric energy has become essential nowadays not only for the daily life of each of us but also for the economy of different countries. The dissemination of geographic information plays an important role in national development as it facilitates communication between managers, investors, and consumers in this sector. Since the management of electricity network data was previously done in Tunisia based on paper maps and plans, the purpose of this article is to present a case of planning based on GIS, Web, and 3D Web GIS, which would have significant positive consequences on this sector from a technical and financial sides with an improvement in customer satisfaction and the creation of an intelligent electricity network which will be a real decision-making tool. This work draws up an inventory of the network MV (Medium Voltage)/LV (Low Voltage) of the region of Medjez El Bab which routes electricity to the big centers of consumption with access to MV/LV subscribers. The analysis of the network's impedance allowed carrying out different scenarios to optimize performance and obtain more realistic routes. Many thematic maps were produced as part of this project (Slope map, Land use map, map of the MV voltage domains, map of the MV/LV transformer stations power, etc.). A three-dimensional virtual city has been developed to visualize the graphical and attribute data for the study area. A Web and 3D Web GIS applications that allows the publication of the interactive maps on the Web as well as the database information have been developed to offer users the possibility of consulting the produced products by internet. Finally, a website related to the study was developed.
CONCEPT PAPER | doi:10.20944/preprints202111.0136.v1
Subject: Physical Sciences, Optics Keywords: laser 3D nanolithography; micro-optics; astrophotonics; 3D printing; additive manufacturing; SZ2080TM; hybrid materials; inorganics; imaging; high temperature.
Online: 8 November 2021 (13:04:13 CET)
A pilot study on laser 3D printing of inorganic free-form micro-optics is experimentally validated. Ultrafast laser nanolithography is employed for structuring hybrid organic-inorganic material SZ2080TM followed by high-temperature calcination post-processing. The combination allows production of 3D architectures and the heat-treatment results in converting the material to inorganic substance. The produced miniature optical elements are characterized and their optical performance demonstrated. Finally, the concept is validated for manufacturing compound optical components such as stacked lenses. This is opening for new directions and applications of laser made microoptics under harsh conditions such as high intensity radiation, temperature, acidic environment, pressure variations, which include open space, astrophotonics, and remote sensing.
REVIEW | doi:10.20944/preprints202208.0145.v1
Subject: Life Sciences, Microbiology Keywords: Leishmania; co-infections; mixed infections; co-culture; hybrid; intercellular communication
Online: 8 August 2022 (10:20:49 CEST)
Leishmania parasites present astonishing adaptative abilities that represent a matter of life or death within disparate environments during the heteroxenous parasite life cycle. From an evolutionary perspective, organisms develop methods of overcoming such challenges. Strategies that extend beyond the genetic diversity have been discussed and include variability between parasite cells during the infections of their hosts. The occurrence of Leishmania subpopulation fluctuations with variable structural genomic contents demonstrates that a single strain might shelter the variability required to overcome inconsistent environments. Such intrastrain variability provides parasites with an extraordinary ability to adapt and thus survive and propagate. However, different perspectives on this evolution have been proposed. Strains or species living in the same environment can cooperate but also compete. These interactions might increase the replication rate of some parasites but cause the loss of more aggressive competitors for others. Adaptive responses to intra- and interspecific competition can evolve as a fixed strategy (replication is adapted to the average genetic complexity of infections) or an optional strategy (replication varies according to the genetic complexity of the current infection). This review highlights the complexity of interspecies and intrastrain interactions among Leishmania parasites as well as the different factors that influence this interplay.
Subject: Biology, Anatomy & Morphology Keywords: Cannabis sativa; Germplasm preservation; Droplet vitrification; Conventional vitrification; Tissue culture
Online: 19 July 2021 (18:13:48 CEST)
Cannabis has developed into a multi-billion dollar industry that relies on clonal propagation of elite genetics with desirable agronomic and chemical phenotypes. While the goal of clonal propagation is to produce genetically uniform plants, somatic mutations can accumulate during growth and compromise long-term genetic fidelity. Cryopreservation is a process in which tissues are stored at cryogenic temperatures, halting cell division and metabolic processes to facilitate high fidelity germplasm preservation. In this study, a series of experiments were conducted to optimize various stages of cryopreservation and develop a protocol for long-term germplasm storage of Cannabis sativa. The resulting protocol uses a standard vitrification procedure to cryopreserve nodal explants from in vitro shoots as follows: Nodes were cultured for 17 hours in a pre-culture solution (PCS), followed by a 20 minute treatment in a loading solution (LS), and a 60 minute incubation in plant vitrification solution 2 (PVS2). The nodes were then flash frozen in liquid nitrogen, re-warmed in an unloading solution at 40°C, and cultured on basal MS culture medium in the dark for 5 days followed by transfer to standard culture conditions. This protocol was tested across 13 genotypes to assess the genotypic variability. The protocol was successful across all 13 genotypes, but significant variation was observed in tissue survival (43.3-80%) and regrowth of shoots (26.7-66.7%). Plants grown from cryopreserved samples were morphologically and chemically similar to control plants for most major traits, but some differences were observed in the minor cannabinoid and terpene profiles. While further improvements are likely possible, this study provides a functional cryopreservation system that works across multiple commercial genotypes for long-term germplasm preservation.
REVIEW | doi:10.20944/preprints202106.0577.v1
Subject: Arts & Humanities, Anthropology & Ethnography Keywords: Material culture, restitution, artefacts, antiquities, cultural objects, western museums, review
Online: 23 June 2021 (11:30:52 CEST)
Background: The saga of repatriating cultural artefacts continues as western museums face increasing pressure from claimants. Western museums that have been involved in the display of historical artefacts, most of which were acquired during the colonial period, have come under huge criticism. A heated discussion of late has been the legitimacy of retaining artefacts in western museums. This study aimed at investigating the ongoing debate regarding the restitution of artefacts. Objective: To investigate the arguments for and against the repatriation of artefacts in relation to diplomatic exchange, preservation, legitimacy and usefulness. Methods: Records will be searched in electronic databases including the University of Manchester Library for Social Anthropology, Scorpus and Project MUSE. Search terms will include "return of artefacts", “return of historical objects”, “return of cultural objects”, “western museums”, “restitution of artefacts”, “repatriation of artefacts”, “restitution of historical objects”, repatriation of historical objects”, “restitution of cultural objects”, “repatriation of cultural objects”, "material culture", "return of antiquities”, restitution of antiquities” and “repatriation of antiquities”. Coding and analysis will be done in SWIFT-Review. The deductive and inductive approaches will be used in synthesising results. Both tabular and graphical methods will be used to present results. Ethics and Results: This study did not need any ethical approval. Results on study characteristics, quality and risk of bias assessments as well as the synthesis of arguments for and against the restitution of artefacts will be presented. The review results will be reported according to appropriate guidelines and disseminated through publication in a relevant journal and presented to stakeholders where necessary. Conclusions: This review will be based on current protocols for systematic review and qualitative evidence synthesis. The study will be the first review that seeks to pull together claims for and against the return of cultural artefacts. The conclusions that will be drawn and recommendations will provide the basis for further research into the debate and the way forward. This study will also help identify the existing gaps regarding the subject matter.
ARTICLE | doi:10.20944/preprints202104.0770.v1
Subject: Social Sciences, Library & Information Science Keywords: Wikipedia, knowledge equity, Wikimedia, open culture, visual arts, cultural bias
Online: 29 April 2021 (09:16:07 CEST)
We explore gaps in Wikipedia's coverage of the visual arts by comparing the representation of 100 artists and 100 artworks from the Western canon against corresponding sets of notable artists and artworks from non-Western cultures. We measure the coverage of these two sets of topics across Wikipedia as a whole and for its individual language versions. We also compare the coverage for Wikimedia Commons and Wikidata, sister-projects of Wikipedia that host digital media and structured data. We show that all these platforms strongly favour the Western canon, giving many times more coverage to Western art. We highlight specific examples of differing coverage of visual art inside and outside the Western canon. We find that European language versions of Wikipedia are generally more "Western" in their coverage and Asian languages more "global", with interesting exceptions. We suggest how both Wikipedia and the wider cultural sector can address this gap in content and thus give Wikipedia a truly global perspective on the visual arts.