bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of in-scanner head pose changes during structural MRI using a convolutional neural network trained on eye tracker video
Authors: Pardoe Heath R , Martin Samantha P , Zhao Yijun , George Allan , Yuan Hui , Zhou Jingjie , Liu Wei , Devinsky Orrin
Published: March 2021

Introduction

In-scanner head motion is a common cause of reduced image quality in neuroimaging, and causes systematic brain-wide changes in cortical thickness and volumetric estimates derived from structural MRI scans. There are few widely available methods for measuring head motion during structural MRI. Here, we train a deep learning predictive model to estimate changes in head pose using video obtained from an in-scanner eye tracker during an EPI-BOLD acquisition with participants undertaking deliberate in-scanner head movements. The predictive model was used to estimate head pose changes during structural MRI scans, and correlated with cortical thickness and subcortical volume estimates.

Methods

21 healthy controls (age 32 ± 13 years, 11 female) were studied. Participants carried out a series of stereotyped prompted in-scanner head motions during acquisition of an EPI-BOLD sequence with simultaneous recording of eye tracker video. Motion-affected and motion-free whole brain T1-weighted MRI were also obtained. Image coregistration was used to estimate changes in head pose over the duration of the EPI-BOLD scan, and used to train a predictive model to estimate head pose changes from the video data. Model performance was quantified by assessing the coefficient of determination (R2). We evaluated the utility of our technique by assessing the relationship between video-based head pose changes during structural MRI and (i) vertex-wise cortical thickness and (ii) subcortical volume estimates.

Results

Video-based head pose estimates were significantly correlated with ground truth head pose changes estimated from EPI-BOLD imaging in a hold-out dataset. We observed a general brain-wide overall reduction in cortical thickness with increased head motion, with some isolated regions showing increased cortical thickness estimates with increased motion. Subcortical volumes were generally reduced in motion affected scans.

Conclusions

We trained a predictive model to estimate changes in head pose during structural MRI scans using in-scanner eye tracker video. The method is independent of individual image acquisition parameters and does not require markers to be to be fixed to the patient, suggesting it may be well suited to clinical imaging and research environments. Head pose changes estimated using our approach can be used as covariates for morphometric image analyses to improve the neurobiological validity of structural imaging studies of brain development and disease.
Exogenous application of non-mature miRNA-encoded miPEP164c inhibits proanthocyanidin synthesis and stimulates anthocyanin accumulation in grape berry cells
Authors: Vale Mariana , Rodrigues Jéssica , Badim Hélder , Gerós Hernâni , Conde Artur
Published: March 2021

Secondary metabolic pathways in grape berries are tightly regulated by an array of molecular mechanisms, including microRNA-mediated post-transcriptional regulation. As recently discovered, before being processed into mature miRNAs, the primary transcripts of miRNAs (pri-miRNAs) can encode for small miRNA-encoded peptides (micropeptides - miPEPs) that ultimately led to an accentuated downregulation of the respective miRNA-targeted genes. Although few studies about miPEPs are available, the discovery of miPEPs reveals a new layer of gene regulation at the post-transcriptional level and may present a key advantage in agronomy.

Here, we identified a miPEP encoded in non-mature miR164c putatively targeting grapevine’s transcription factor VvMYBPA1 (miPEP164c/miPEP-MYBPA1), a positive regulator of key genes in the proanthocyanidin-biosynthetic pathway, one that competes directly for substrate with the anthocyanin-biosynthetic pathway.

Thus, the objective of this work was to test the hypothesis that the exogenous application of miPEP164c (miPEP-MYBPA1) can modulate the secondary metabolism of grape berry cells by inhibiting PA biosynthetic pathway while simultaneously stimulating anthocyanin synthesis.

The exogenous application of miPEP164c to suspension-cultured cells from grape berry (cv. Gamay) enhanced the transcription of its corresponding pri-miR164c, thus leading to a more pronounced post-transcriptional silencing of its target VvMYBPA1. This led to a significant inhibition of the proanthocyanidin pathway, mostly via inhibition ofleucoanthocyanidin reductaseandanthocyanidin reductaseenzymatic activities and VvLAR1downregulation. In parallel, the anthocyanin-biosynthetic route was stimulated. Anthocyanin content was 31 % higher in miPEP164c-treated cells, in agreement with the higher activity of VvUFGT and the correspondingVvUFGT1transcripts.
Inhibitory properties of microalgal extracts on thein vitroreplication of cyprinid herpesvirus 3
Authors: Stefanie Fritzsche , Patrik Blenk , Jürgen Christian , Kathrin Castiglione , Maria Becker Anna
Published: March 2021

Microalgae often stand out for their high biodiversity as well as their associated large number of potent bioactives. Therefore, they are interesting candidates as possible sources of antiviral substances, e.g. against cyprinid herpesvirus 3 (CyHV-3). Although this virus leads to high mortalities in aquacultures, there is no treatment available yet. Hence, ethanolic extracts produced with accelerated solvent extraction from six microalgal species(Arthrospira platensis, Chlamydomonas reinhardtii, Chlorella kessleri, Haematococcus pluvialis, Nostoc punctiformeandScenedesmus obliquus)were examined in this study for inhibitory effects on viral replication. An inhibition of thein vitroreplication of CyHV-3 in common carp brain cells could be confirmed for all six species, with the greatest effect for theC. reinhardtiiandH. pluvialisextracts. At still non-cytotoxic concentrations viral DNA replication was reduced by over 3 orders of magnitude (> 99.9 %) each compared to the untreated replication controls, while the virus titers were at or even below the limit of detection. When pre-incubating cells and virus withC. reinhardtiiand especiallyH. pluvialisextracts before inoculation, the reduction of viral DNA and virus titer was even stronger. Based on these results, an intervention in the initial replication steps like viral adsorption or membrane fusion is assumed. Moreover, a protection mechanism preventing the production of viral proteins and the assembly of mature virions is also possible. All in all, the results show that microalgae are a very promising source of natural antiviral substances against CyHV-3.
Synchrotron total-scattering data applicable to dual-space structural analysis
Authors: Beyer Jonas , Kato Kenichi , Brummerstedt Iversen Bo
Published: March 2021

Synchrotron powder X-ray diffraction (PXRD) is a well established technique for investigating the atomic arrangement of crystalline materials. At modern beamlines, X-ray scattering data can be collected in a total-scattering setting, which additionally opens up the opportunity for direct-space structural analysis through the atomic pair distribution function (PDF). Modelling of PXRD and PDF data is typically carried out separately, but employing a concurrent structural model to both direct- and reciprocal-space data has the possibility to enhance total-scattering data analysis. However, total-scattering measurements applicable to such dual-space analyses are technically demanding. Recently, the technical demands have been fulfilled by a MYTHEN microstrip detector system (OHGI), which meets the stringent requirements for both techniques with respect to Q range, Q resolution and dynamic range. In the present study, we evaluate the quality of total-scattering data obtained with OHGI by separate direct- and reciprocal-space analysis of Si. Excellent agreement between structural parameters in both spaces is found, demonstrating that the total-scattering data from OHGI can be utilized in dual-space structural analysis e.g. for in situ and operando measurements.
Crystal structure and Hirshfeld surface analysis of (3S,3aR,6aS)-3-(1,3-diphenyl-1H-pyrazol-4-yl)-5-(4-methoxyphenyl)-2-phenyl-3,3a,4,5,6,6a-hexahydro-2H-pyrrolo[3,4-d][1,2]oxazole-4,6-dione
Authors: Mohamed Shaaban K. , Said Awad I. , Mague Joel T. , El-Emary Talaat I. , Akkurt Mehmet , Elgarhy Sahar M. I.
Published: March 2021

In the title compound, C33H26N4O4, the two fused five-membered rings and their N-bound aromatic substituents form a pincer-like motif. The relative conformations about the three chiral carbon atoms are established. In the crystal, a combination of C—H...O and C—H...N hydrogen bonds and C—H...π(ring) interactions leads to the formation of layers parallel to the bc plane. A Hirshfeld surface analysis indicates that the most significant contributions to the crystal packing are from H...H (44.3%), C...H/H...C (29.8%) and O...H/H...O (15.0%) contacts.
Art collecting as consumption and entrepreneurial marketing as strategy
Authors: Fillis Ian , Lehman Kim
Published: March 2021

Purpose

The authors adopt a biographical methodology to investigate how a privately funded art museum has risen to become a key visitor destination on the island of Tasmania, Australia.

Design/methodology/approach

The authors utilise both entrepreneurship and consumption as collecting lenses to gain insight into the success of a new arts venture. In addition to biographical methodology the authors utilise in-depth interviews and participant observation.

Findings

The analysis shows what can be achieved when alternative paths to creativity and innovation are pursued. The creativity inherent in such actions does not necessarily have to be substantial. Sometimes incremental approaches to achieving something different from the norm are sufficient.

Research limitations/implications

Implications include the continued merits of adopting a biographical approach to uncovering longitudinal insight into interlinking entrepreneurship and consumption practices. This approach enables key impacting events over time to be identified as they impact on the direction taken by the art entrepreneur.

Practical implications

There is growing evidence that administrative approaches to arts governance are limiting in their effectiveness. This paper addresses the call to be more entrepreneurial in arts governance practices.

Originality/value

There are only a limited number of papers on entrepreneurship and consumption in the arts and this research adds to knowledge in the area.
Debt financing and firm performance: empirical evidence from the Pakistan Stock Exchange
Authors: Nazir Aamir , Azam Muhammad , Khalid Muhammed Usman
Published: March 2021

Purpose

The purpose of this study is to investigate the relationship between the listed firms' debt level and performance on the Pakistan Stock Exchange (PSX) during a five-year period.

Design/methodology/approach

This study uses pooled ordinary least squares regression and fixed- and random-effects models to analyse a cross-sectional sample of 30 Pakistani companies operating in the automobile, cement and sugar sectors during 2013–2017 (N = 150).

Findings

The results indicate that both short- and long-term debt have negative and significant impacts on firm performance in profitability. This suggests that agency issues may lead to a high-debt policy, resulting in lower performance. However, both sales growth and firm size have positive effects on the profitability of non-financial sector companies.

Research limitations/implications

This study suggests that when debt financing significantly and negatively influences firm profitability, company owners and managers should focus on finding a satisfactory debt level. However, this study is limited to the automobile, cement and sugar sectors of Pakistan. Future studies could address other sectors, such as textiles, fertilizers and pharmaceuticals.

Originality/value

This study focusses on enhancing the existing empirical knowledge of debt financing's influence on the PSX's major sectors' profitability.
Contextual and corporate governance effects on carbon accounting and carbon performance in emerging economies
Authors: Cordova Carmen , Zorio-Grima Ana , Merello Paloma
Published: March 2021

Purpose

This paper aims to explore the driving forces for having carbon reporting and carbon reduction management strategies in emerging and developing countries.

Design/methodology/approach

The methodology employed uses logit and linear panel data models and generalized moments method, to avoid endogeneity problems.

Findings

The results show that the carbon reporting decision is positively related to being located in Africa or America (as opposed to Asia), publishing a sustainability report and having certain corporate governance (CG) attributes such as a corporate social responsibility (CSR) committee, larger board size and an executive compensation policy based on environmental and social performance. Regarding the driving forces leading to a reduction of carbon emissions, no evidence is obtained on the effect of the variables considered.

Practical implications

The evidence obtained is valuable, as it can help standard-setters in these geographical areas to promote actions in the field of CG to increase transparency. Nonetheless, additional measures to disclosure should be needed in the future to help decrease carbon emissions more effectively.

Social implications

Raising awareness amongst companies helps mimetic isomorphism take place so that efforts can be made to report levels of pollution in an initial phase, which hopefully in the future may be managed to try to keep a decreasing path. Therefore, implications of this research are crucial for emerging and developing countries, as they are especially vulnerable to climate change.

Originality/value

To the best of the authors’ knowledge, this is the first paper to look into this phenomenon in emerging and developing countries from Asia, Africa and America. This contribution is unique as this research shows that location, publication of a sustainability report together with some CG attributes are drivers for carbon transparency.
Cultural capital and destination image: Insights from the Opera House tourist
Authors: Guachalla Adrian
Published: March 2021

Purpose

This paper aims to identify the factors that foster an interest in opera and Opera Houses as a specific form of cultural capital and how the Opera House tourist constructs images of destinations from the cognitive, affective and conative dimensions.

Design/methodology/approach

A social constructivist methodology was adopted, and data was captured through online qualitative questionnaires from 226 Opera House tourists using a simple random sampling approach. These enquired about the development of their interest in opera and Opera Houses and the influence this exerts on their destination image formation process.

Findings

This form of cultural capital is mainly developed by exposure to art forms through family, social and further reference groups. Opera Houses project cognitive images of cosmopolitanism, affective images of social belonging and conative images of further opportunities to experience culture and leisure fostering destination loyalty and place attachment.

Research limitations

Productions of both opera and ballet are staged at Opera Houses, opening avenues for further research on either the opera or ballet tourist markets specifically using case studies across the ample spectrum of Opera Houses around the world.

Practical implications

In addition to the visual appeal and quality of cultural produce, tourism practitioners can use an Opera House’s projected affective images of social cohesion and togetherness to attract the Opera House tourist market. Opera Houses enrich a destination’s visual and cultural landscapes, cementing the need to preserve and promote their contributions to the destination’s cultural identity.

Social implications

This study highlights the need for cultural policy and audience development strategies that cultivate this type of cultural capital resulting in demand for and supply of cultural products that in turn stimulate the development of this niche cultural tourism market segment.

Originality/value

To the best of author’s knowledge, this is the first study that has approached the Opera House tourist from the destination image formation context.
Synthesis of Bi2WO6/g-C3N4 photocatalyst and high degradation of Rhodamine B under visible light irradiation
Authors: Wang Wenjie , Zhang Mengran , Zhao Binxia , Liu Linxue , Han Ruixuan , Wang Nan
Published: March 2021

Purpose

The purpose of this paper is to improve the degradation efficiency of Rhodamine B (RhB) by new photocatalytic materials.

Design/methodology/approach

Binary Z-scheme g-C3N4/Bi2WO6 photocatalytic material was synthesized by the one-step hydrothermal reaction. The construction of Z-scheme heterojunction led to the rapid separation of photogenerated electrons and holes, which would degrade RhB into small molecular substances to achieve the purpose of degradation.

Findings

It was found that Bi2WO6/25%g-C3N4 displayed the highest photocatalytic activity, which was about 1.44 and 1.34 times higher than that of pure Bi2WO6 and g-C3N4, respectively. According to the trapping experiments, the superoxide radical (·O2−) was the major active species of the RhB decomposition in Bi2WO6/g-C3N4 catalysts.

Originality/value

The successful synthesis of Z-scheme Bi2WO6/g-C3N4 provides new ideas and references for the design of catalysts with high photocatalytic activity, which should have wide applications in the future.
The relationships between TQM, TPM, JIT and agile manufacturing: an empirical study in industrial companies
Authors: Khalfallah Meriem , Lakhal Lassaad
Published: March 2021

Purpose

This empirical study aims to explore the relationship between Total quality management (TQM), Total productive/preventive maintenance (TPM) and Just-in time (JIT). It also seeks to examine the relationship between Just-in time (JIT) and agile manufacturing.

Design/methodology/approach

Data for the study were collected from a survey of 205 industrial companies and the relationships proposed in the framework were tested using structural equation modeling.

Findings

The results indicate that (1) TPM has a positive impact on TQM and JIT, (2) TQM has a positive effect on JIT and (3) JIT has a direct positive relationship with agile manufacturing. In addition, the results reveal an indirect effect of TPM and TQM on agile manufacturing through JIT.

Research limitations/implications

The conceptual model proposed and tested in this study can be used by researchers for developing Lean manufacturing practices (TQM, TPM and JIT) and agile manufacturing theory. In addition, this model shows to practitioners the importance of integrating TQM, TPM and JIT in manufacturing firms. In other words, this study shows practitioners how firms can support their agile manufacturing system.

Originality/value

This research presents an innovative approach since it examines simultaneously the interdependencies between TQM, TPM and JIT and their direct and indirect link with agile manufacturing using structural equation modeling.
Optimization‐based recursive filtering for separation of signal from harmonics in vibroseis
Authors: Denisov M.S. , Egorov A.A. , Shneerson M.B.
Published: March 2021

Harmonic noise may significantly complicate the processing of slip‐sweep vibroseis data. We propose a model of this noise and an optimal recursive filtering algorithm based on this model. In contrast to some alternatives, this method can remove harmonic noise caused by all the events on the seismic gather, instead of only removing the noise associated with the first arrivals. First, the algorithm predicts a number of noise models that correspond to the harmonics of different orders. Second, these models are subtracted from the input gather via adaptive subtraction, which estimates frequency‐dependent relative amplitudes of harmonics and introduces the needed phase shifts into the noise models. When applied to the field vibroseis data, the proposed algorithm successfully separates the harmonic noise from the signal.
Charismatic authority and fractured polities: A cross‐national analysis
Authors: Davis Andrew P. , Vila‐Henninger Luis
Published: March 2021

Sociological research has overlooked the political consequences of charismatic leadership that arises in existing democratic political bureaucracies. In this article, we theorize the consequences of charismatic leadership in democratic nations by revisiting Max Weber's theory of charismatic authority. Our extension of Weber's theory of charismatic authority helps to address a gap in the political polarization literature concerning the role of charismatic leadership. This article provides a foundational link in the research on charismatic authority–bridging the literatures on charisma and cross‐national comparative sociology. This bridging is enabled by advances in data collection that include information on charismatic authority in cross‐national context. This article makes use of a Driscoll and Kraay fixed‐effects analysis across 76 democracies from 1960 to 2009 to explore the relationship between charismatic leadership and political polarization. Our findings suggest that nations with higher levels of charismatic leadership tend to have higher levels of political polarization. These results contribute to both the literature on political polarization and charisma—as well as support our extension of Weber's theory of charismatic authority.
Predicting the risk of developing type 2 diabetes in Chinese people who have coronary heart disease and impaired glucose tolerance
Authors: Xu Shishi , Scott Charles A.B. , Coleman Ruth L. , Tuomilehto Jaakko , Holman Rury R.
Published: March 2021

Aims

Robust diabetes risk estimates in Asian patients with impaired glucose tolerance (IGT) and coronary heart disease (CHD) are lacking. We developed a Chinese type 2 diabetes risk calculator using Acarbose Cardiovascular Evaluation (ACE) trial data.

Methods

There were 3105 placebo‐treated ACE participants with requisite data for model development. Clinically relevant variables, and those showing nominal univariate association with new‐onset diabetes (P < .10), were entered into BASIC (clinical variables only), EXTENDED (clinical variables plus routinely available laboratory results), and FULL (all candidate variables) logistic regression models. External validation was performed using the Luzhou prospective cohort of 1088 Chinese patients with IGT.

Results

Over median 5.0 years, 493 (15.9%) ACE participants developed diabetes. Lower age, higher body mass index, and use of corticosteroids or thiazide diuretics were associated with higher diabetes risk. C‐statistics for the BASIC (using these variables), EXTENDED (adding male sex, fasting plasma glucose, 2‐hour glucose, and HbA1c), and FULL models were 0.610, 0.757, and 0.761 respectively. The EXTENDED model predicted a lower 13.9% 5‐year diabetes risk in the Luzhou cohort than observed (35.2%, 95% confidence interval 31.3%‐39.5%, C‐statistic 0.643).

Conclusion

A risk prediction model using routinely available clinical variables can be used to estimate diabetes risk in Chinese people with CHD and IGT.
Awareness and utilisation of advanced gynaecological ultrasound in the preoperative work‐up of women planning surgery for endometriosis: A survey of RANZCOG fellows and trainees
Authors: Menakaya Uchefuna A. , Hannedege Bhatiya , Infante Fernando , Lanzarone Valeria , Adno Alan , Johnson Neil P.
Published: March 2021

Background

Endometriosis‐specific (advanced gynaecological) ultrasound is recommended as part of preoperative work‐up of women with suspected endometriosis.

Aim

To evaluate the awareness and utilisation of advanced gynaecological ultrasound in the preoperative work‐up of women with suspected endometriosis among active RANZCOG (Royal Australian and New Zealand College of Obstetricians and Gynaecologists) fellows and trainees.

Materials and methods

Anonymous online survey invitations were emailed to all active RANZCOG fellows in Australia and New Zealand. Descriptive analysis of responses and multivariate analysis where appropriate were performed. P < 0.05 was considered statistically significant.

Results

A 17% (437/2567) survey response rate and 93% (409/437) completion rate were recorded; 59% (248/421) of respondents identified as generalists, whereas 15% (63/421) identified as advanced laparoscopic surgeons. Routine pelvic ultrasound (88.9%, 361/406) was the most common imaging modality requested by respondents; 32% (128/405) of respondents would also always request advanced gynaecology ultrasound. Respondents’ self‐reported practice type was significantly associated with utilisation of advanced gynaecological ultrasound (P = 0.03); 79.6% (348/437) agreed with our proposed definition of advanced gynaecological ultrasound for endometriosis. A major limitation to the utilisation of advanced gynaecological ultrasound for endometriosis was the lack of local expertise (63.8%, 233/356).

Conclusion

The utilisation of advanced gynaecological ultrasound for endometriosis is significantly influenced by respondents’ self‐reported practice type and limited by the lack of local expertise.
Channels for Influence or Maps of Behavior? A Field Experiment on Social Networks and Cooperation
Authors: Atwell Paul , Nathan Noah L.
Published: March 2021

Communities in developing countries often must cooperate to self‐provide or co‐produce local public goods. Many expect that community social networks facilitate this cooperation, but few studies directly observe real‐life networks in these settings. We collect detailed social network data in rural Northern Ghana to explore how social positions and proximity to community leaders predict donations to a local public good. We then implement a field experiment manipulating participants' opportunity to communicate and apply social pressure before donating. We find clear evidence that locations in community social networks predict cooperative behavior, but no evidence that communication improves coordination or cooperation, in contrast to common theoretical expectations and laboratory findings. Our results show that evolved, real‐life social networks serve as a mapping of community members' already‐engrained behaviors, not only as an active technology through which social influence propagates to solve collective action problems.
Driving vision in patients with neovascular AMD in anti‐VEGF treatment
Authors: Ferløv Baselius Nanna Jo , Brynskov Troels , Falk Mads Krüger , Sørensen Torben Lykke , Subhi Yousif
Published: March 2021

Purpose

To report real‐world experiences on driving vision in patients with neovascular age‐related macular degeneration (AMD) undergoing intravitreal anti‐VEGF treatment.

Methods

Retrospective cohort study of treatment‐naïve patients with neovascular AMD commenced in anti‐VEGF treatment (n = 416) and followed for 4 years in a pro re nata treatment regimen. Monocular best‐corrected visual acuity (BCVA) measured using ETDRS was performed on the treatment eye at all visits and on the fellow eye at baseline, every 6 months, and upon any patient‐reported change in vision. Driving vision was defined as BCVA in the best‐seeing eye of ≥70 ETDRS letters (equivalent to ≥0.5 Snellen) corresponding to the minimum BCVA required in many countries.

Results

Driving vision was present in 280 patients (67%) and was sustained in 86%, 74%, 65% and 59% of the patients at 1, 2, 3 and 4 years, respectively. Lower BCVA in the best‐seeing eye predicted loss of driving vision. In patients without driving vision at baseline, driving vision was regained in 29%, 36%, 39% and 41% of the patients at 1, 2, 3 and 4 years, respectively; but only 35% sustained driving vision after the first year. Lower age and higher BCVA in best‐seeing eye predicted regain of driving vision.

Conclusion

Driving vision can be sustained in the majority of the patients if they have driving vision at baseline. This study provides important prognostic information for patients with neovascular AMD.
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

Objectives

Mammalian 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 Methods

Germ 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.

Results

In 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.

Conclusions

Our 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

An 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

Aim

Deserts 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.

Location

The Arabian Peninsula.

Taxon

Squamate reptiles (Squamata; lizards and snakes).

Methods

We 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.

Results

The 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 conclusions

The 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

Objectives

To study the effect of artificial aging on color stability, translucency, and surface roughness of stained all‐ceramic restorations.

Materials and methods

Disc‐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).

Results

Artificial 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.

Conclusions

Chemical aging had significantly affected the optical parameters and surface texture of stained monolithic ceramics.

Clinical Significance

Stained 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

Therizinosaurs 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

Purpose

The 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 methods

Twenty‐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).

Results

Crown 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).

Conclusions

Crown 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

Purpose

Because 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.

Methods

We 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.

Findings

The 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.

Conclusions

Not 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

Questions

Shrub 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?

Location

Nuup Kangerlua (Godthåbsfjord), western Greenland.

Methods

We tested the power of nine climatic, topographic and biotic variables to explain the abundances of nine shrub species using a Bayesian hierarchical modelling framework.

Results

We 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.

Conclusions

Shrub 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

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

Xanthomonasalbilineans(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.