bluuebunny/crossref_metadata_2025_split huggingface dataset:
RNA helicase DDX5 acts as a critical regulator for survival of neonatal mouse gonocytes
Authors: Xia Qing , Cui Guizhong , Fan Ye , Wang Xiuqin , Hu Gongcheng , Wang Lisha , Luo Xi , Yang Lele , Cai Qingqing , Xu Kaibiao , Guo Wenjing , Gao Minghui , Li Yingying , Wu Ji , Li Wei , Chen Jiayu , Qi Huayu , Peng Guangdun , Yao Hongjie 
Published: March 2021

AbstractObjectivesMammalian spermatogenesis is a biological process of male gamete formation. Gonocytes are the only precursors of spermatogonial stem cells (SSCs) which develop into mature spermatozoa. DDX5 is one of DEAD‐box RNA helicases and expresses in male germ cells, suggesting that Ddx5 plays important functions during spermatogenesis. Here, we explore the functions of Ddx5 in regulating the specification of gonocytes.Materials and MethodsGerm cell‐specific Ddx5 knockout (Ddx5‐/‐) mice were generated. The morphology of testes and epididymides and fertility in both wild‐type and Ddx5‐/‐ mice were analysed. Single‐cell RNA sequencing (scRNA‐seq) was used to profile the transcriptome in testes from wild‐type and Ddx5‐/‐ mice at postnatal day (P) 2. Dysregulated genes were validated by single‐cell qRT‐PCR and immunofluorescent staining.ResultsIn male mice, Ddx5 was expressed in germ cells at different stages of development. Germ cell‐specific Ddx5 knockout adult male mice were sterile due to completely devoid of germ cells. Male germ cells gradually disappeared in Ddx5‐/‐ mice from E18.5 to P6. Single‐cell transcriptome analysis showed that genes involved in cell cycle and glial cell line‐derived neurotrophic factor (GDNF) pathway were significantly decreased in Ddx5‐deficient gonocytes. Notably, Ddx5 ablation impeded the proliferation of gonocytes.ConclusionsOur study reveals the critical roles of Ddx5 in fate determination of gonocytes, offering a novel insight into the pathogenesis of male sterility.
Providing interactive and field laboratories while teaching university marine biology classes in an era of COVID‐19
Authors: Cowles David L. , Onthank Kirt L. 
Published: March 2021

AbstractAn entirely online upper‐division university marine invertebrates course modeled after a field experience‐intensive course that also provided interaction with live animals and research experience was offered at Rosario Beach Marine Laboratory in the summer of 2020. We describe online methods we used for providing field experiences to students participating online, as well as a workstation and interactive method for identification and detailed anatomical examination of live macroinvertebrates with students. Students were also involved as active participants in a field research project. Nearly all of the equipment involved is inexpensive or readily available in most university biology laboratories or classrooms.
Diversity patterns and evolutionary history of Arabian squamates
Authors: Šmíd Jiří , Sindaco Roberto , Shobrak Mohammed , Busais Salem , Tamar Karin , Aghová Tatiana , Simó‐Riudalbas Marc , Tarroso Pedro , Geniez Philippe , Crochet Pierre‐André , Els Johannes , Burriel‐Carranza Bernat , Tejero‐Cicuéndez Héctor , Carranza Salvador 
Published: March 2021

AbstractAimDeserts are generally perceived as areas of low diversity, and hence receive little attention from researchers and conservationists. Squamates are the dominant group of vertebrates in arid regions, and as such represent an ideal model to study biodiversity patterns in these areas. We examine spatial patterns of diversity, evolutionary history and endemism of terrestrial squamates of the Arabian Peninsula and test hypotheses on the role of topography and history of isolation so as to identify possible environmental drivers of diversification.LocationThe Arabian Peninsula.TaxonSquamate reptiles (Squamata; lizards and snakes).MethodsWe generated distribution maps for all Arabian squamate species (including yet undescribed) and reconstructed their phylogenetic relationships using existing and newly produced genetic data for nearly all the species. We assessed patterns of the distribution of species richness, phylogenetic diversity and phylogenetic endemism across the peninsula to identify areas that could be considered evolutionary or endemicity hotspots for squamates. We evaluated community turnover across the peninsula and assessed the possible environmental drivers affecting the diversity of Arabian squamates in a regression framework.ResultsThe main hotspots of Arabian squamate diversity are mostly along the mountains that rim the peninsula while the most arid, central regions support a low diversity of species. The distribution of the phylogenetic diversity mirrors that of the species richness. Phylogenetic endemism is also highest in the mountains, especially when only endemic species are analysed. The deserts of northern Arabia are poor in terms of species richness and they show low connectivity to the peninsular communities. Topographic heterogeneity is the strongest predictor for Arabian squamates, followed by elevation. There is no correlation between richness and temperature.Main conclusionsThe mountains of Arabia support rich and unique squamate communities that are dominated by local radiations of closely related and narrow‐ranging species. In particular, the Asir Mountains of SW Arabia, Dhofar Province of Oman and the Hajar Mountains of northern Oman and UAE show unprecedented levels of squamate endemism and phylogenetic endemism. While many generalist species range across Arabia, a low number of species is shared between the peninsula and mainland Asia, indicating an effective isolation of the Arabian fauna. Squamate richness is highest in heterogeneous, topographically complex habitats.
Effect of chemical aging on color stability and surface properties of stained all‐ceramic restorations
Authors: Habib Angel W. , Aboushelib Moustafa N. , Habib Nour A. 
Published: March 2021

AbstractObjectivesTo study the effect of artificial aging on color stability, translucency, and surface roughness of stained all‐ceramic restorations.Materials and methodsDisc‐shaped specimens were fabricated from six different all‐ceramic materials: two glass ceramics (Vita Mark II and Empress CAD), two lithium disilicate based ceramics (e.max and Suprinity), and two zirconia‐based materials (ZirCAD LT and ZirCAD MT Multi). The discs were stained using two universal stains; IPS Ivocolor stain or Vita Akzent stain. Color change (ΔE) and the translucency parameter (TP) were measured before and after artificial aging. The surface roughness (Ra) was evaluated using atomic force microscopy, while the surface microstructure was evaluated using scanning electron microscopy (SEM). Quantitative elemental analysis was performed using the energy dispersive X‐ray (EDX). Leached ions were analyzed by inductively coupled plasma (ICP) (n = 12, α = 0.05).ResultsArtificial aging had significantly changed the color (ΔE) and decreased the translucency (TP) of all stained ceramics. The mean surface roughness (Ra) was significantly increased in all specimens, which was also confirmed in the SEM scans. EDX analysis revealed a decrease in the elemental composition of the stained surface as a result of ceramic degradation, except for Ca and Zn in IPS Ivocolor stain. Furthermore, the ICP analysis revealed that most compositional elements of stain and glaze were detected in the aging solution.ConclusionsChemical aging had significantly affected the optical parameters and surface texture of stained monolithic ceramics.Clinical SignificanceStained ceramics are liable to color degradation. Each type of stain should be used with its corresponding type of ceramic. Stained all‐ceramic restorations are liable to color change and surface degradation during function.
Forelimb musculature and function in the therizinosaur Nothronychus (Maniraptora, Theropoda)
Authors: Smith David K. 
Published: March 2021

AbstractTherizinosaurs are unusual theropods from the Upper Cretaceous of Asia and North America. North American representatives include Falcarius utahensis from central Utah, Nothronychus mckinleyi from west central New Mexico, and N. graffami from southern Utah. Nothronychus was quite large, with well‐developed forelimbs and pectoral girdle. In many respects, however, these structures were typical for conventional carnivorous theropods, although therizinosaurs have been hypothesized to be herbivorous using anatomical and functional inferences. There is no indication of increased range of motion within the forelimbs, as might be predicted for derived non‐avian theropods. The muscular anatomy of the pectoral girdle and forelimb of Nothronychus is reconstructed using visible muscle scars, data from extant birds and crocodilians, and models for other theropods. The osteology and inferred musculature is a mosaic of primitive and derived characters for theropods. A fossa pneumotricipitales may have been present in the proximal humerus. There was a well‐developed fossa brachialis in the distal humerus. The epicleidium of the furcula is deflected, reflecting either taphonomic deformation or possibly accommodation of M. supracoracoideus in a triosseal canal, but such a development has yet to be described in any non‐avian theropod. In many respects, the other muscular results were quite similar to those inferred for dromaeosaurs.
Effect of Crown Height on the Screw Stability of Titanium Screw‐Retained Crowns
Authors: Yilmaz Burak , Batak Burcu , Seghi Robert , Johnston William M. , Lang Lisa A. 
Published: March 2021

AbstractPurposeThe aim of this in vitro study was to evaluate the effect of crown height on the screw stability of screw‐retained titanium implant crowns subjected to cyclic loading conditions.Materials and methodsTwenty‐one implants with internal hex connections were placed in epoxy resin holders. Mandibular first molar screw‐retained titanium implant crowns with UCLA type, crown‐abutment connections were CAD/CAM fabricated. Seven crowns of 3 different heights (6 mm, 10 mm, and 14 mm) were made. The crowns were seated onto the implants and screws were tightened to 30 Ncm. The implants were clamped into holders and stepwise cyclic loads were applied to the occlusal surface at 30‐degree angles to the long axes of the crowns. The detorque values were measured after each 5 million cycles. Before increasing the applied load, the crowns were secured with new screws and tightened to 30 Ncm. Failure times, survival estimates and detorque values were then analyzed. (alpha = 0.05).ResultsCrown height did not significantly affect detorque values. However, five 14‐mm crowns failed with varying fractures during the 475 N loading condition. Overall, a significantly lower survival for 14 mm crowns was found compared to 6 mm and 10 mm crowns (p = 0.004).ConclusionsCrown heights of one‐piece screw‐retained titanium implant crowns did not significantly affect detorque values. Screw fracture, however, was greater for crown height of 14 mm than those of 6 mm and 10 mm.
Health information source use and trust among a vulnerable rural disparities population
Authors: Myrick Jessica Gall , Hendryx Michael 
Published: March 2021

AbstractPurposeBecause rural residents, particularly those near mining sites, are susceptible to numerous environmental health hazards, it is important to gain deeper insights into their use and trust of health information, which they may employ to help recognize symptoms, learn ways to reduce exposure, or find health care.MethodsWe surveyed residents (N = 101) of rural Kentucky, Virginia, and West Virginia to assess predictors of health information source use and trust. A project manager administered face‐to‐face paper and pencil questionnaires assessing demographics, health status, smoking behavior, and health information use and source trust. Bivariate correlations and ordinary least squares regressions were used to analyze the data.FindingsThe data suggest that rural individuals frequently use nurses, doctors, and websites to seek health information, whereas traditional media are often not their preferred channel for health information. Media sources were not found as trustworthy as interpersonal and medical health information sources. While only 13.0% of individuals in the sample said they ever turned to county or state health departments for health information, these sources were trusted more than any media source and more than friends. Moreover, living closer to active mining sites—meaning these individuals are at a higher risk of environmental health hazards—predicted even less use of traditional media and greater trust in peer sources.ConclusionsNot all sources of health information are equally used or trusted by individuals from a rural disparities population. The findings have implications for health campaign message dissemination and intervention designs targeting individuals in rural Appalachia.
Annual air temperature variability and biotic interactions explain tundra shrub species abundance
Authors: von Oppen Jonathan , Normand Signe , Bjorkman Anne D. , Blach‐Overgaard Anne , Assmann Jakob J. , Forchhammer Mads , Guéguen Maya , Nabe‐Nielsen Jacob 
Published: March 2021

AbstractQuestionsShrub vegetation has been expanding across much of the rapidly changing Arctic. Yet, there is still uncertainty about the underlying drivers of shrub community composition. Here, we use extensive vegetation surveys and a trait‐based approach to answer the following questions: which abiotic and biotic factors explain abundance of shrub species and functional groups in the Arctic tundra, and can we interpret these relationships using plant traits related to resource acquisition?LocationNuup Kangerlua (Godthåbsfjord), western Greenland.MethodsWe tested the power of nine climatic, topographic and biotic variables to explain the abundances of nine shrub species using a Bayesian hierarchical modelling framework.ResultsWe found highly variable responses among species and functional groups to both abiotic and biotic environmental variation. The overall most important abiotic explanatory variable was annual air temperature variability, which was highly correlated with winter minimum air temperature. Functional community composition and graminoid abundance were the most influential biotic factors. While we did not find systematic patterns between shrub abundances and abiotic variables with regard to resource acquisition traits, these traits did explain relationships between shrub abundances and biotic variables.ConclusionsShrub abundance responses to abiotic variables rarely aligned with expectations based on plants’ resource acquisition traits or functional groups. Our results, therefore, indicate that approaches exclusively based on resource acquisition traits might be limited in their ability to predict abundances of individual groups and species, particularly in response to complex abiotic environments. However, integrating community theory and functional trait concepts represents a promising pathway to better predict biotic interactions and ultimately responses of dominant shrub vegetation to rapid environmental changes across the arctic tundra biome.
Metabolomics‐driven gene mining and genetic improvement of tolerance to salt‐induced osmotic stress in maize
Authors: Liang Xiaoyan , Liu Songyu , Wang Tao , Li Fenrong , Cheng Jinkui , Lai Jinsheng , Qin Feng , Li Zhen , Wang Xiangfeng , Jiang Caifu 
Published: March 2021

Summary

The farmland of the world’s main corn‐producing area is increasingly affected by salt stress. Therefore, the breeding of salt‐tolerant cultivars is necessary for the long‐term sustainability of global corn production.

Previous studies have shown that natural maize varieties display a large diversity of salt tolerance, yet the genetic variants underlying such diversity remain poorly discovered and applied, especially those mediating the tolerance to salt‐induced osmotic stress (SIOS). Here we report a metabolomics‐driven understanding and genetic improvement of maize SIOS tolerance.

Using a LC‐MS‐based untargeted metabolomics approach, we profiled the metabolomes of 266 maize inbred lines under control and salt conditions, and then identified 37 metabolite biomarkers of SIOS tolerance (METO1‐37). Follow‐up metabolic GWAS (mGWAS) and genotype‐to‐phenotype modeling identified 10 candidate genes significantly associating with the SIOS tolerance and METO abundances. Furthermore, we validated that a citrate synthase, a glucosyltransferase and a cytochrome P450 underlie the genotype–METO–SIOS tolerance associations, and showed that their favorable alleles additively improve the SIOS tolerance of elite maize inbred lines.

Our study provides a novel insight into the natural variation of maize SIOS tolerance, which boosts the genetic improvement of maize salt tolerance, and demonstrates a metabolomics‐based approach for mining crop genes associated with this complex agronomic trait.
Virulence factors analysis of native isolates ofXanthomonas albilineansandXanthomonas saccharifrom Tucumán, Argentina, reveals differences in pathogenic strategies
Authors: Mielnichuk Natalia , Bianco María I. , Yaryura Pablo M. , Bertani Romina P. , Toum Laila , Daglio Yasmín , Colonnella María Antonela , Lizarraga Leonardo , Castagnaro Atilio P. , Vojnov Adrián A. 
Published: March 2021

AbstractXanthomonasalbilineans(Xa) andX.sacchari(Xs) are both sugarcane pathogens. Xa is the causal agent of leaf scald disease, but there is limited information about the pathogenicity of Xs. The aim of this work was to study virulence factors of native strains of Xa (Xa32, Xa33, and XaM6) and Xs (Xs14 and Xs15) previously isolated from sugarcane with leaf scald symptoms, to gain insight into the biology of each microorganism. We analysed epiphytic survival, sensitivity to oxidative stress, extracellular degradative enzymes, cell motilities, exopolysaccharide (EPS) characteristics, cell adhesion, biofilm development, and control of stomatal regulation of the five strains. We observed that each species presented similar phenotypes for every factor analysed. Xa strains appeared to be more sensitive to oxidative stress and presented lower epiphytic survival than Xs. All strains presented endoglucanase activity; however, we could only detect protease and amylase activities in Xs strains. Swimming and sliding were higher in Xs, but twitching was variable among species. We also observed that only Xs strains produced a xanthan‐like EPS, presented a strong cell adhesion, and structured biofilm. We detected some intraspecific variations showing that higher amounts of EPS produced by Xs14 correlated with its higher sliding motility and its homogenous and more adhesive biofilm. In addition, EPSs of Xs14 and Xs15 presented differences in strand height and acetyl percentage. Finally, we found that strains of both species were able to interfere with stomatal aperture mechanism. All these differences could influence the colonization strategies and/or disease progression in each species.
CX3CR1 might be a promising predictor of systemic lupus erythematosus patients with pulmonary fibrosis
Authors: Qiu Fen , Li Youling , Zhu Yunhe , Li Gang , Lei Feifei , Zhang Shuang , Luo Lei , Zhu Jietao , Guo Yang , Du Boyu , Xi Xueyan 
Published: March 2021

AbstractThe inflammatory process in systemic lupus erythematosus (SLE) affects many organs including the lungs. Chemokines are suggested to play important roles in the pathogenesis of SLE with pulmonary fibrosis (PF). In the present study, our objective is to evaluate the correlation between chemokines and PF in SLE patients. Transcriptome sequencing analysis was used to find the different expressed genes between SLE patients with PF and without PF. Enzyme‐linked immunosorbent assay (ELISA) was used to detect serum levels of chemokines in SLE patients and healthy controls. Expression of CX3CR1 was measured by real‐time polymerase chain reaction (PCR) and flow cytometer. Sixteen differentially chemokine genes were found to be associated to SLE with PF. Meanwhile, the upregulation of C‐X3‐C motif chemokine receptor 1 (CX3CR1) and its ligand, CX3C chemokine ligand 1 (CX3CL1) were observed in SLE patients with PF than that of SLE patients without PF and healthy control. Phenotypic analysis also showed that the surface expression of CX3CR1 increased in PBMCs from SLE patients with PF. Our observations indicated that CX3CL1/CX3CR1 axis is associated with PF in SLE. CX3CR1 might be a promising predictor of SLE with PF and the interactions between CX3CL1 and CX3CR1 might provide potential candidate target for the treatment of SLE with PF.
Validation of an apoptosis assay for extracorporeal photopheresis
Authors: Hähnel Viola , Dormann Frauke , Kronenberg Katharina , Hutchinson James A. , Burkhardt Ralph , Ahrens Norbert 
Published: March 2021

AbstractObjectivesThis validation study investigated a flow cytometric apoptosis assay according to good manufacturing practice (GMP).BackgroundExtracorporeal photopheresis (ECP) is a treatment for various immunological diseases and cutaneous T‐cell lymphomas. It is based on the induction of apoptosis by 8‐methoxypsoralene and ultraviolet A light. The quantification of apoptosis is therefore essential for ECP improvements. However, despite numerous publications on apoptosis, validated technical details are lacking.Methods and materialsMononuclear cells were collected by apheresis and treated by ECP or camptothecin. Samples taken before and after ECP were cultured for 24, 48 and 72 h and analysed for apoptosis and viability of T cells and monocytes by flow cytometry with Annexin V and 7‐AAD staining. Accuracy of the assay, intra‐ and inter‐assay precision and the pre‐analytical and analytical stability of the analytes were the investigated parameters.ResultsOur data indicate that the median intra‐ and inter‐assay precision coefficient of variation for T cells was 3.86% and 4.80%, respectively. Pre‐analytical stability of T cells and monocytes was ensured during short‐term storage for up to 2 h on ice. After staining, analytical stability was limited to 30 min, likely because of ongoing apoptosis and loss of monocytes due to plastic adhesion.ConclusionThe results of this validation study show that the assay is GMP‐compliant and that its reliability, accuracy and precision are acceptable. While pre‐analytical stability of the cells was compatible with on‐site procedures, our analytical stability data indicate that this assay is not suited for batch mode analysis of ECP products.