bluuebunny/crossref_metadata_2025 huggingface dataset:
Scaling of subcellular structures with cell length through decelerated growth
Authors: McInally Shane G. , Kondev Jane , Goode Bruce L.
Published: March 2021

How cells tune the size of their subcellular parts to scale with cell size is a fundamental question in cell biology. Until now, most studies on the size control of organelles and other subcellular structures have focused on scaling relationships with cell volume, which can be explained by limiting pool mechanisms. Here, we uncover a distinct scaling relationship with cell length rather than volume, revealed by mathematical modeling and quantitative imaging of yeast actin cables. The extension rate of cables decelerates as they approach the rear of the cell, until cable length matches cell length. Further, the deceleration rate scales with cell length. These observations reveal a new mode of scaling that senses the linear dimensions of a cell.

One Sentence Summary

As actin cables in yeast cells grow longer, their extension rate decelerates, enabling the cable length to match cell length.
EHF is essential for epidermal and colonic epithelial homeostasis and suppressesApc-initiated colonic tumorigenesis
Authors: Reehorst Camilla M. , Nightingale Rebecca , Luk Ian Y. , Jenkins Laura , Koentgen Frank , Williams David S. , Darido Charbel , Tan Fiona , Anderton Holly , Chopin Michael , Schoffer Kael , Eissmann Moritz F. , Buchert Michael , Mouradov Dmitri , Sieber Oliver M , Ernst Matthias , Dhillon Amardeep S. , Mariadason John M.
Published: March 2021

Background

Ets homologous factor (EHF) is a member of the epithelial-specific Ets (ESE) transcription factors. EHF is specifically expressed in epithelial tissues, however its role in development and epithelial homeostasis is largely uncharacterized.

Methods

We generated a novel mouse strain in which the Ets DNA binding domain (exon 8) of Ehf was flanked by loxP sites (EhfLox/Lox). To inactivate Ehf in the whole body,EhfLox/Loxmice were crossed toCMVCremice, which were then bred out to generate germlineEhfnull (Ehf−/−) mice. To inactivate Ehf specifically in the intestinal epithelium,EhfLox/Loxmice were bred to tamoxifen-inducibleVillinCre-ERT2mice.EhfLox/Loxmice were also crossed to tamoxifen-inducibleCdx2CreERT2;ApcLox/+mice to determine the impact of Ehf deletion on Apc-initiated colon cancer development.

Results

Transcripts encoding the Ets binding domain of EHF were effectively deleted in all tissues inEhf−/−mice.Ehf−/−mice were born at the expected Mendelian ratio, but showed reduced body weight gain and developed a series of pathologies during their lifespan that led the majority ofEhf−/−mice to reach an ethical endpoint within one year of age. Most prominent of these were the development of papillomas in the chin, and abscesses in the preputial glands (males) or vulvae (females) which showed evidence of Staphylococcus and Proteus infection. Consistent with the development of papillomas, the epidermis ofEhf−/−mice showed evidence of mild hyperplasia. A subset ofEhf−/−mice also developed cataracts and corneal ulcers. EHF is highly expressed in the colonic epithelium andEhf−/−mice displayed increased susceptibility to dextran sodium sulphate-induced colitis. This phenotype was confirmed in intestinal-specific Ehf knockout mice, and histopathological analyses revealed reduced numbers of goblet cells and extensive transcriptional reprogramming in the colonic epithelium. Finally, colon-specific deletion ofEhfenhancedApc-initiated adenoma development, unveiling a novel, tumour suppressive role for EHF in colorectal cancer.

Conclusion

The Ets DNA-binding domain of EHF is essential for post-natal homeostasis of the epidermis and colonic epithelium, and functions as a tumour suppressor in the colon.
A simple, cost-effective and automation-friendly direct PCR approach for bacterial community analysis
Authors: Song Fangchao , Kuehl Jennifer V. , Chandran Arjun , Arkin Adam P.
Published: March 2021

Bacterial communities in water, soil, and humans play an essential role in environmental ecology and human health. PCR-based amplicon analysis, such as 16S ribosomal RNA sequencing, is a fundamental tool for quantifying and studying microbial composition, dynamics, and interactions. However, given the complexity of microbial communities, a substantial number of samples becomes necessary to analyses that parse the factors that determine microbial composition. A common bottleneck in performing these kinds of experiments is genomic DNA (gDNA) extraction, which is time-consuming, expensive, and often biased on the types of species. Direct PCR methods are a potentially simpler and more accurate alternative to gDNA extraction methods that do not require the intervening purification step. In this study, we evaluated three variations of direct PCR methods using diverse heterogeneous bacterial cultures, ZymoBIOMICS Microbial Community Standards, and groundwater. By comparing direct PCR methods with DNeasy blood and tissue kits and DNeasy Powersoil kits, we found a specific variant of the direct PCR method exhibits a comparable overall efficiency to the conventional DNeasy Powersoil protocol. We also found the method showed higher efficiency for extracting gDNA from the gram negative strains compared to DNeasy blood and tissue protocol. This direct PCR method is 1600 times cheaper ($0.34 for 96 samples), 10 times simpler (15 min hands-on time for 96 samples) than DNeasy Powersoil protocol. The direct PCR method can also be fully automated, and is compatible with small volume samples, thereby permitting scaling of samples and replicates needed to support high-throughput large-scale bacterial community analysis.

IMPORTANCE

Understanding bacterial interaction and assembling in complex microbial communities using 16S ribosomal RNA sequencing normally requires a large experimental load. However, the current DNA extraction methods including cell disruption and genomic DNA purification are normally biased, costly, time and labor consuming, and not amenable to miniaturization by droplets or 1536 well plates due to the significant DNA loss during purification step for tiny volume and low cell density samples. Direct PCR method could potentially solve these problems. In this study, we demonstrate a direct PCR method which exhibits similar efficiency as the widely used method – DNeasy Powersoil protocol, while 1600 times cheaper and 10 times faster to execute. This simple, cost-effective, and automation friendly direct PCR based 16S ribosomal RNA sequencing method allows us to study the dynamics, microbial interaction and assembly of varying microbial communities in a high throughput fashion.
Feline leukemia virus (FeLV) endogenous and exogenous recombination events result in multiple FeLV-B subtypes during natural infection
Authors: Erbeck Katelyn , Gagne Roderick B. , Kraberger Simona , Chiu Elliott S. , Roelke Parker Melody , VandeWoude Sue
Published: March 2021

Feline leukemia virus (FeLV) is associated with a range of clinical signs in felid species. The primary hosts of FeLV are domestic cats of the Felis genus that also harbor endogenous FeLV (enFeLV) elements stably integrated in their genomes. EnFeLV elements display 86% nucleotide identity to exogenous, horizontally transmitted FeLV (FeLV-A). Variation between enFeLV and FeLV-A is primarily in the long terminal repeat (LTR) and env regions, which potentiates generation of FeLV-B recombinant subtypes during natural infection with enhanced virulence. The aim of this study was to examine exogenous FeLV (exFeLV) and enFeLV recombination events in a natural FeLV epizootic. We previously described that of 32 individuals in a closed colony with productive FeLV-A infection, 22 had detectable circulating FeLV-B. We cloned and sequenced the env gene of FeLV-B, FeLV-A, and enFeLV spanning known recombination breakpoints, examining between 1-13 clones per individual to assess sequence diversity and recombination sites. We documented multiple recombination breakpoints resulting in the production of unique FeLV-B genotypes. At least half of the cats harbored more than one FeLV-B variant, and almost all animals had variants similar to those recovered from at least one other individual in the colony. This analysis reveals that FeLV-B is predominantly generated de novo within each host, though horizontal transmission may be inferred based upon FeLV-B sequence identities between individuals. This work represents a comprehensive analysis of endogenous-exogenous retroviral interactions with important insights into host-viral interactions that underlie disease pathogenesis in a natural setting.

Importance

Feline leukemia virus (FeLV) is a felid retrovirus associated with a variety of disease outcomes. Exogenous FeLV-A is the most common horizontally transmitted virus subgroup. Domestic cats (Felis catus) harbor endogenous copies of FeLV (enFeLV) in their genomes. Recombination between FeLV-A and enFeLV may result in emergence of largely replication-defective, but highly virulent recombinant strains. FeLV-B, the most common recombinant form, results when enFeLV env recombines with FeLV-A during FeLV replication. This study evaluated endogenous-exogenous recombination outcomes in a naturally-infected closed colony of domestic cats to determine recombination sites and FeLV-B genotypic heterogeneity associated with enhanced disease virulence. While FeLV-A and enFeLV genotypes were highly conserved, a large number of unique FeLV-B variants were identified in association with predicted recombination hotspots. The findings provide insight into recombination events between viral and host genomes that result in new, and potentially more pathogenic, viral strains.
ZFP207controls pluripotency by multiple post-transcriptional mechanisms
Authors: Malla Sandhya , Bhattarai Devi Prasad , Melguizo-Sanchis Dario , Atanasoai Ionut , Groza Paula , Román Ángel-Carlos , Zhu Dandan , Lee Dung-Fang , Kutter Claudia , Aguilo Francesca
Published: March 2021

The pluripotent state is not solely governed by the action of the core transcription factors Oct4, Sox2, and Nanog, but also by a series of co-transcriptional and post-transcriptional events, including alternative splicing (AS) and the interaction of RNA-binding proteins (RBPs) with defined subpopulations of RNAs. Zinc Finger Protein 207 (ZFP207) is an essential transcription factor for mammalian embryonic development. Here, we employ multiple functional analyses to characterize the role of ZFP207 in mouse embryonic stem cells (ESCs). We find that ZFP207 plays a pivotal role in ESC maintenance, and silencing ofZfp207leads to severe neuroectodermal differentiation defects. In striking contrast to human ESCs, ZFP207 does not transcriptionally regulate stem cell and neuronal-related genes but exerts its effects by control AS networks and acting as an RBP. Our study expands the role of ZFP207 to maintain ESC identity, and underscores ZFP207 functional versatility with key roles in neural fate commitment.
Satellite Cell Expression of RAGE is Important for Collateral Vessel Formation
Authors: Hansen Laura , Joseph Giji , Taylor W. Robert
Published: March 2021

Objective

The growth and remodeling of vascular networks is an important component of the prognosis for patients with peripheral artery disease. One protein that has been previously implicated to play a role in this process is the receptor for advanced glycation end products or RAGE. This study sought to determine the cellular source of RAGE in the ischemic hindlimb and the role of RAGE signaling in this cell type.

Approach and Results

Using a hind limb ischemia model of vascular growth, this study found skeletal muscle satellite cells to be a novel major cellular source of RAGE in ischemic tissue by both staining and cellular sorting. While wild type satellite cells increased TNFα and MCP-1 production in response to ischemiain vivoand a RAGE ligandin vitro, satellite cells from RAGE knockout mice lacked the increase in cytokine production both in vivo in response to ischemia and in vitro after stimuli with the RAGE ligand HMGB-1. Furthermore, encapsulated wild type satellite cells improved perfusion after hind limb ischemia surgery by both perfusion staining and vessel quantification but RAGE knockout satellite cells provided no improvement over empty capsules.

Conclusions

Thus, RAGE expression and signaling in satellite cells is crucial for their response to stimuli and angiogenic and arteriogenic functions.

Graphical Abstract
Synthesis and structure of a complex of copper(I) with L-cysteine and chloride ions containing Cu12S6 nanoclusters
Authors: Gizatullin Amir , Becker Jonathan , Islamov Daut , Serov Nikita , Schindler Siegfried , Klimovitskii Alexander , Shtyrlin Valery
Published: March 2021

The title hydrated copper(I)–L-cysteine–chloride complex has a polymeric structure of composition {[Cu16(CysH2)6Cl16]·xH2O}
n
[CysH2 = HO2CCH(NH3
+)CH2S− or C3H7NO2S], namely, poly[[tetra-μ3-chlorido-deca-μ2-chlorido-dichloridohexakis(μ4-L-cysteinato)hexadecacopper] polyhydrate]. The copper atoms are linked by thiolate groups to form Cu12S6 nanoclusters that take the form of a tetrakis cuboctahedron, made up of a Cu12 cubo-octahedral subunit that is augmented by six sulfur atoms that are located symmetrically atop of each of the Cu4 square units of the Cu12 cubo-octahedron. The six S atoms thus form an octahedral subunit themselves. The exterior of the Cu12S6 sphere is decorated by chloride ions and trichlorocuprate units. Three chloride ions are coordinated in an irregular fashion to trigonal Cu3 subunits of the nanocluster, and four trigonal CuCl3 units are bonded via each of their chloride ions to a copper ion on the Cu12S6 sphere. The trigonal CuCl3 units are linked via Cu2Cl2 bridges covalently connected to equivalent units in neighboring nanoclusters. Four such connections are arranged in a tetrahedral fashion, thus creating an infinite diamond-like net of Cu12S6Cl4(CuCl3)4 nanoclusters. The network thus formed results in large channels occupied by solvent molecules that are mostly too ill-defined to model. The content of the voids, believed to be water molecules, was accounted for via reverse Fourier-transform methods using the SQUEEZE algorithm [Spek (2015). Acta Cryst. C71, 9–18]. The protonated amino groups of the cysteine ligands are directed away from the sphere, forming N—H...Cl hydrogen bonds with chloride-ion acceptors of their cluster. The protonated carboxy groups point outwards and presumably form O—H...O hydrogen bonds with the unresolved water molecules of the solvent channels. Disorder is observed in one of the two crystallographically unique [Cu16(CysH2)6Cl16] segments for three of the six cysteine anions.
Sino-Western rivalry in the COVID-19 “vaccine wars”–A race to the bottom?
Authors: Wong Wilson Kia Onn
Published: March 2021

Purpose

This paper analyses the escalating Sino-Western race to develop a safe, efficacious and durable vaccine (i.e. “Goldilocks COVID-19 vaccine”). It argues that such efforts would be considerably more effective if there is greater international cooperation instead of the corrosive rivalry driven by misplaced nationalism.

Design/methodology/approach

This study deploys a case-study approach, supported by literature on existing coronavirus disease 2019 (COVID-19) vaccine development efforts.

Findings

Despite the seeming success of recent COVID-19 vaccines, their actual efficacy is far from certain. Moreover, access to these vaccines would not be equitable internationally. This problem is exacerbated by the fact that their unique properties make storage and distribution prohibitively expensive, and international mechanisms to provide distribution to economically depressed regions are non-existent. Given the significant difficulties, it would be incumbent upon the great powers (i.e. China and America) to work together not only in vaccine development but also in the establishment of a distribution platform to ensure equitable access worldwide.

Originality/value

This study is one of the few social science research papers on COVID-19 vaccine development and its implications for society at large.
Investment appraisal and financial benefits of corporate green buildings: a developing economy case study
Authors: Verma Saurabh , Mandal Satya N. , Robinson Spenser , Bajaj Deepak , Saxena Anupam
Published: March 2021

Purpose

This case study aims to appraise the financial benefits of green building construction in developing countries. The case study presents, green building's positive net present value (NPV) investment in real terms and potentially enhanced stock market returns at the firm level compared to competitors.

Design/methodology/approach

The case study examines secondary data on a green building certification and longitudinal operation costs to estimate green building investments' financial benefits. The case study also compares the stock market performance of green building portfolio company with non-green building competitors of similar size and industry.

Findings

The case study finds out that the real return rate on green building investment is higher than the weighted average cost of capital (WACC) of the company with an inflation-adjusted payback period of fewer than ten years. Findings compare favourably to the extant literature which was mostly in developed economies. The paper further highlights that stock market performance for a green building focused company shows improved returns to shareholders relative to non-green competitors.

Research limitations/implications

The results are specific to the time and building researched; green buildings costs have reduced over time, and a new study may show improved case study findings. The case study results on stock market performance are indicative and may need further research for evaluation.

Practical implications

The case study presents a model for critical appraisal of green buildings investment. The paper further indicates that green building investment may lead to operational savings and superior stock performance compared to competitors.

Originality/value

The paper presents a green building investment appraisal model which might be useful for the industry and academia. Developing countries have limited literature on green buildings' financial benefits; this case study quantifies the financial benefits and compares them with the available literature related to developed economies’ green buildings.
Using optimal choice of parameters for meta-extreme learning machine method in wind energy application
Authors: Dokur Emrah , Karakuzu Cihan , Yüzgeç Uğur , Kurban Mehmet
Published: March 2021

Purpose

This paper aims to deal with the optimal choice of a novel extreme learning machine (ELM) architecture based on an ensemble of classic ELM called Meta-ELM structural parameters by using a forecasting process.

Design/methodology/approach

The modelling performance of the Meta-ELM architecture varies depending on the network parameters it contains. The choice of Meta-ELM parameters is important for the accuracy of the models. For this reason, the optimal choice of Meta-ELM parameters is investigated on the problem of wind speed forecasting in this paper. The hourly wind-speed data obtained from Bilecik and Bozcaada stations in Turkey are used. The different number of ELM groups (M) and nodes (Nh) are analysed for determining the best modelling performance of Meta-ELM. Also, the optimal Meta-ELM architecture forecasting results are compared with four different learning algorithms and a hybrid meta-heuristic approach. Finally, the linear model based on correlation between the parameters was given as three dimensions (3D) and calculated.

Findings

It is observed that the analysis has better performance for parameters of Meta-ELM, M = 15 − 20 and Nh = 5 − 10. Also considering the performance metric, the Meta-ELM model provides the best results in all regions and the Levenberg–Marquardt algorithm -feed forward neural network and adaptive neuro fuzzy inference system -particle swarm optimization show competitive results for forecasting process. In addition, the Meta-ELM provides much better results in terms of elapsed time.

Originality/value

The original contribution of the study is to investigate of determination Meta-ELM parameters based on forecasting process.
Doctoral capital and well-being amongst Australian PhD students: exploring capital and habitus of doctoral students
Authors: Usher Wayne , McCormack Brittany A.
Published: March 2021

Purpose

The Higher Degree Research (HDR) journey is known for its difficulties, complexities and challenges (Lees-Deutsch, 2020), with many students experiencing multi-faceted issues and concerns (Skopek et al., 2020). Therefore, the purpose of this research is to investigate the relationships that exist between variables, vulnerability factors and doctorial capital of candidates (n = 532) studying at Australian universities (2019).

Design/methodology/approach

A quantitative cross-sectional correlational research design and Bronfenbrenner's socio – ecological framework (personal, home, university, community) was utilised to collect participants' (n = 532) descriptive statistics. Bourdieu's social reproduction theory was used as a lens to examine how experiences, across the PhD candidature, are influenced by several psychosocial factors and doctoral capital.

Findings

From such a dual methodological approach, the findings from this study suggests that (1) age, (2) gender, (3) nationality, (4) financial/work status, (5) years of PhD and (6) attending postgraduate (PG) student events, go to significantly (p < 0.001) impact (positively and negatively) on students' experiences and correspondingly, impacts on their self-confidence, motivation and mental health and well-being status.

Research limitations/implications

Research limitations are related to the recruitment of more doctoral students across more Australian universities. Further research is required from HDR supervisors, so as to “balance” the experiences of the PhD journey in higher education.

Practical implications

In order to succeed in academia and HDR programs, students need to identify with and develop the “right kind of capital” to successfully navigate fields of social and scholarly play. Investigating how the participants perceive their social and scholarly habitus is seen as crucial in helping students to develop positive dispositions relevant to being a doctoral student.

Social implications

The concept of doctoral capital and well-being, amongst Australian PhD students, is under researched and requires further investigation as a precursor to developing more specific policy designs aimed at providing heightened positive learning environments/HDR programs tailored to support doctoral students.

Originality/value

Whilst reforms to improve PhD experiences are well established across the international literature (Geven et al., 2018; Skopek et al., 2020), evidence for Australia is largely missing. It is envisaged, that findings from this research will further assist in the development of quality policies that would go to provide effective services and support for doctoral students within Australian universities.
Moving learning online and the COVID-19 pandemic: a university response
Authors: Webb Aleksandra , McQuaid Ronald William , Webster C. William R.
Published: March 2021

Purpose

This article investigates some ongoing issues faced by higher education institutions (HEIs) having to rapidly move their teaching online during the early stages of the coronavirus (COVID-19) pandemic.

Design/methodology/approach

The article incorporates a review of academic and policy literature concerning digitalisation and online learning in universities and qualitative interviews with staff involved in online teaching and learning at a university in Scotland.

Findings

For most HEIs and organisations across the globe, the COVID-19 pandemic has accelerated the speed at which digitalisation and digital ways of working have been embedded in organisational life and service delivery including new ways of learning and working. This has led to a recognition of the need for practically focused, effective inclusive digital interventions. A range of initiatives that have been developed or accelerated in response to the pandemic are discussed. These should be explicitly designed and implemented to also reach individuals from disadvantaged backgrounds, including those with low-skill levels or qualifications and older age groups. Effort is also needed by policymakers and HEIs to better understand the challenges and unintended consequences that digital learning and working poses.

Research limitations/implications

More research is needed into the methods and implications of increased online teaching. The range of interviewees is limited to one main organisation. A wider range of staff, students, HEIs and other types of organisation would add additional insights.

Practical implications

Insights from interviews highlight a number of institutional responses to digitalisation, which were accelerated by the COVID-19 pandemic. These identify learning and reflection points for HEIs moving to enhanced online teaching provision.

Originality/value

This article provides an analysis of the processes, issues and impacts associated with the rapid shift to digitisation in HEIs at a point in time shortly following the onset of the COVID-19 pandemic in 2020. It raises issues around inclusivity of online learning, pedagogy, unintended consequences of digitalisation and privacy, when moving to online teaching that are relevant both during the pandemic and in the longer term.
Determinants of accounting students’ undergraduate learning satisfaction
Authors: Adler Ralph , Roberts Helen , Crombie Neil , Dixon Keith
Published: March 2021

This paper examines factors that influence the learning satisfaction of business school students in general and accounting students in particular. Guided by both the literature and the findings from a series of eight focus group sessions involving 43 university undergraduates, a research instrument capable of examining factors associated with student learning satisfaction was designed. Survey responses from 548 students generated seven factors of student satisfaction, with students attributing high importance to all seven factors. It was further found that gender and student major moderated the relationship between the seven factors and students’ reported learning satisfaction.
Combining apical torsional load and cyclic fatigue resistance of NiTi instruments: New approach to determine the effective lifespan of rotary instruments
Authors: Iacono Francesco , Pirani Chiara , Gatto Maria Rosaria , Prati Carlo , Peters Ove A.
Published: March 2021

In the described proof‐of‐principle experiments, we introduced a novel testing device to investigate how different concurrent torsional loads influence the cyclic fatigue (CF) resistance of a nickel–titanium (NiTi) instrument. The device was designed to test CF resistance of NiTi files with a standardized load on the apical 5 mm; a movable cylinder controlled by a lever provided a uniform real‐time load. Thirty‐three NiTi instruments 25.04 (F360, Komet, Lemgo, Germany) were rotated until fracture at 30° curvature under three different torsional loads (n = 11 each); Group A: 2.5 Ncm; Group B: 5 Ncm; Group C: 10 Ncm. anova, multiple comparisons Tamhane tests, regression and Kaplan–Meyer analysis were performed to contrast means. Resistance to cyclic fatigue differed significantly among groups (P = 0.0001). Increased torsional loads led to a decrease in time to failure. An inverse correlation (r = −0.721, P = 0.001) was observed between time and torsional load, with higher torsional loads correlated to shorter times to fracture.
Retinal oximetry with a prototype handheld oximeter during hyperoxia
Authors: Vehmeijer Wouter B. , Jonkman Kelly , Hardarson Sveinn H. , Aarts Leon , Stefansson Einar , Dahan Albert , Schalij‐Delfos Nicoline E.
Published: March 2021

Purpose

Retinal oximetry measures oxygen saturation in retinal vessels. With the introduction of a mobile handheld prototype oximeter, this technique will become available for a broader patient population including bedridden patients and newborn babies. The objective is to determine the sensitivity of this handheld oximeter in room air and during isocapnic hyperoxia. A comparison is made between the handheld oximeter and the Oxymap T1.

Methods

Thirteen young healthy subjects with a mean age of 25 ± 2 years were recruited at the Leiden University Medical Center. Retinal oximetry images were acquired during normoxia and during isocapnic hyperoxia for both the prototype oximeter and the OxymapT1. Isocapnic hyperoxia was induced with the dynamic end‐tidal forcing technique. For both oximeters, the oxygen saturation and vessel width were measured with Oxymap Analyzer software. The hyperoxic state was verified with blood gas analysis.

Results

The mean oxygen saturation measured with the handheld oximeter in arterioles was 91.3% ± 3.9% during normoxia and 94.6% ± 3.9% during hyperoxia (p = 0.001). Oxygen saturation in venules was 56.3% ± 9.8% during normoxia and 82.2 ± 7.4% during hyperoxia (p < 0.001). For the Oxymap T1, the mean oxygen saturation for arterioles was 94.0% ± 2.6% during normoxia and 95.4%±3.2% during hyperoxia (p = 0.004). For the venules, the oxygen saturation was during normoxia 58.9%±3.2% and 84.3 ± 4.0% during hyperoxia (p < 0.001).

Conclusion

The handheld retinal oximeter is sensitive to the changes in inhaled oxygen concentration. A small increase in oxygen saturation was measured in the arterioles and a larger increase in the venules. The handheld oximeter gives similar values as the ‘gold standard’ Oxymap T1 oximeter.
Physiological responses to a school task: The role of student–teacher relationships and students’ emotional appraisal
Authors: Mastromatteo Libera Ylenia , Zaccoletti Sonia , Mason Lucia , Scrimin Sara
Published: March 2021

Background

To be successful, students must learn to deal with socially and cognitively demanding tasks. Much remains unknown about the effects of previous classroom experiences and of students’ emotional appraisal of a task on their physiological adaptive responses to it.

Aims

To investigate how children’s physiological response to a social and cognitive task would be directly and interactively influenced by the perceived student–teacher relationship and by children’s emotional appraisal of what reaction they expect to have while completing the task.

Methods

One hundred and sixteen second and third graders took part in the study. Children completed a cognitive and social stress task. Before the task, they were interviewed on their emotional appraisal of the task and on student–teacher relationships. Children’s cardiac activity was registered at rest and during the task to measure physiological activation (heart rate) and self‐regulation (heart rate variability).

Results

Heart rate variability during the task was positively correlated with the appraised emotional valence of the task and of being observed while doing it. Regression analyses showed that children’s physiological self‐regulation during the task was affected by the interaction between student–teacher relationships and appraised emotional valence of being observed. Only among children who had experienced negative student–teacher relationships, an active physiological self‐regulation was observed in response to the task when they expected it to be positive compared to when they perceived it as negative.

Conclusions

Children’s emotional appraisal of tasks and the quality of student–teacher relationships are important to promote a functional physiological response of self‐regulation that underlies academic functioning and well‐being at school.
Microglial/Macrophage polarization and function in brain injury and repair after stroke
Authors: Lyu Junxuan , Xie Di , Bhatia Tarun N. , Leak Rehana K. , Hu Xiaoming , Jiang Xiaoyan
Published: March 2021

Stroke is a leading cause of disability and mortality, with limited treatment options. After stroke injury, microglia and CNS‐resident macrophages are rapidly activated and regulate neuropathological processes to steer the course of functional recovery. To accelerate this recovery, microglia can engulf dying cells and clear irreparably‐damaged tissues, thereby creating a microenvironment that is more suitable for the formation of new neural circuitry. In addition, monocyte‐derived macrophages cross the compromised blood‐brain barrier to infiltrate the injured brain. The specific functions of myeloid lineage cells in brain injury and repair are diverse and dependent on phenotypic polarization statuses. However, it remains to be determined to what degree the CNS‐invading macrophages occupy different functional niches from CNS‐resident microglia. In this review, we describe the physiological characteristics and functions of microglia in the developing and adult brain. We also review (a) the activation and phenotypic polarization of microglia and macrophages after stroke, (b) molecular mechanisms that control polarization status, and (c) the contribution of microglia to brain pathology versus repair. Finally, we summarize current breakthroughs in therapeutic strategies that calibrate microglia/macrophage responses after stroke.
Animal models for the study of depressive disorder
Authors: Song Juhyun , Kim Young‐Kook
Published: March 2021

Depressive disorder is one of the most widespread forms of psychiatric pathology, worldwide. According to a report by the World Health Organization, the number of people with depression, globally, is increasing dramatically with each year. Previous studies have demonstrated that various factors, including genetics and environmental stress, contribute to the risk of depression. As such, it is crucial to develop a detailed understanding of the pathogenesis of depressive disorder and animal studies are essential for identifying the mechanisms and genetic disorders underlying depression. Recently, many researchers have reported on the pathology of depression via various models of depressive disorder. Given that different animal models of depression show differences in terms of patterns of depressive behavior and pathology, the comparison between depressive animal models is necessary for progress in the field of the depression study. However, the various animal models of depression have not been fully compared or evaluated until now. In this paper, we reviewed the pathophysiology of the depressive disorder and its current animal models with the analysis of their transcriptomic profiles. We provide insights for selecting different animal models for the study of depression.
Women and Global South strikingly underrepresented among top‐publishing ecologists
Authors: Maas Bea , Pakeman Robin J , Godet Laurent , Smith Linnea , Devictor Vincent , Primack Richard
Published: March 2021

The global scientific community has become increasingly diverse over recent decades, but is this ongoing development also reflected among top‐publishing authors and potential scientific leaders? We surveyed 13 leading journals in ecology, evolution, and conservation to investigate the diversity of the 100 top‐publishing authors in each journal between 1945 and 2019. Out of 1051 individual top‐publishing authors, only 11% are women. The United States, the United Kingdom, Australia, Germany, and Canada account for more than 75% of top‐publishing authors, while countries of the Global South (as well as Russia, Japan, and South Korea) were strikingly underrepresented. The number of top‐publishing authors who are women and/or are from the Global South is increasing only slowly over time. We outline transformative actions that scientific communities can take to enhance diversity, equity and inclusion at author, leadership, and society level. The resulting promotion of scientific innovation and productivity is essential for the development of global solutions in conservation science.
Analysis of GABRG2 C588T polymorphism in genetic epilepsy and evaluation of GABRG2 in drug treatment
Authors: Wang Shitao , Zhang Xianjun , Zhou Liang , Wu Qian , Han Yanbing
Published: March 2021

Epilepsy is a common disorder with complex inheritance, and its treatment is very unsatisfactory. An association between the GABRG2 C588T polymorphism and genetic generalized epilepsy has been studied by several genetic association studies. However, these results were inconsistent, and the role of GABRG2 in epilepsy treatment remains unknown. To evaluate the role of GABRG2 in epilepsy, we performed meta‐analysis, expression quantitative trait loci analysis, protein–protein interaction analysis, and drug–gene interaction analysis. The combined results indicated that the GABRG2 C588T polymorphism was associated with genetic generalized epilepsy risk under dominant and allelic models (odds ratio [OR] = 1.25, 95% confidence interval [CI] = 1.02–1.54, p = 0.03, I2 = 0% and OR = 1.21, 95% CI = 1.03–1.42, p = 0.02, I2 = 20%, respectively). In the Asian population, we also found similar results under dominant and allelic models (OR = 1.93, 95% CI = 1.18–3.16, p = 0.009, I2 = 0% and OR = 1.69, 95% CI = 1.20–2.37, p = 0.003, I2 = 11%, respectively). We first found that the GABRG2 C588T polymorphism regulates GABRG2 expression in human brain tissues and that the protein encoded by GABRG2 interacts with targets of approved antiepileptic drugs (AEDs). Interestingly, we also found that GABRG2 itself interacts with approved AEDs. Taken together, the results indicate that the C588T polymorphism might alter the GABAA receptor by modulating GABRG2 gene expression, resulting in increased risk for epilepsy, and that GABRG2 may be a potential therapeutic target for epilepsy.
Prevalence and incidence of epilepsy in Latin America and the Caribbean: A systematic review and meta‐analysis of population‐based studies
Authors: Alva‐Díaz Carlos , Navarro‐Flores Alba , Rivera‐Torrejon Oscar , Huerta‐Rosario Andrely , Molina Roberto A. , Velásquez‐Rimachi Victor , Morán‐Mariños Cristian , Farroñay Chandel , Pacheco‐Mendoza Josmel , Metcalf Tatiana , Burneo Jorge G. , Pacheco‐Barrios Kevin
Published: March 2021

Objective

This study was undertaken to perform an updated systematic review and meta‐analysis to estimate the pooled prevalence and incidence of epilepsy in Latin America and the Caribbean (LAC), describing trends over time, and exploring potential clinical and epidemiological factors explaining the heterogeneity in the region.

Methods

Observational studies assessing the incidence or prevalence of epilepsy in LAC countries up to March 2020 were systematically reviewed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta‐Analyses) guidelines. Meta‐analyses and cumulative analyses were performed using random‐effects models. We assessed between‐study heterogeneity with sensitivity, subgroup, and meta‐regression analyses. Moreover, the quality of the included studies and the certainty of evidence were evaluated using the GRADE (grading of recommendation, assessment, development, and evaluation) approach.

Results

Overall, 40 studies (from 42 records) were included, 37 for prevalence analyses and six for incidence (312 387 inhabitants; 410 178 person‐years). The lifetime prevalence was 14.09 per 1000 inhabitants (95% confidence interval [CI] = 11.72–16.67), for active epilepsy prevalence was 9.06 per 1000 individuals (95% CI = 6.94–11.44), and the incidence rate was 1.11 per 1000 person‐years (95% CI = .65–1.70). These high estimates have been constant in the region since 1990. However, substantial statistical heterogeneity between studies and publication bias were found. The overall certainty of evidence was low. Methodological aspects (sample size) and countries’ epidemiological characteristics such as access to sanitation services and child and adult mortality rates explained the high heterogeneity. Finally, the prevalence of epilepsy associated with neurocysticercosis (NCC) in the general population was high, and the proportion of NCC diagnosis among people living with epilepsy was 17.37%.

Significance

The epilepsy prevalence and incidence in LAC are higher than worldwide estimates, being constant since 1990 and strongly influenced by NCC. We identified high between‐study heterogeneity and significant methodological limitations (e.g., heterogeneous definitions, lack of longitudinal studies). The region needs upgraded research using standardized definitions and diagnostic methods, and urgent action against preventable causes.
Impacts of climate change on the Bay of Seine ecosystem: Forcing a spatio‐temporal trophic model with predictions from an ecological niche model
Authors: Bourdaud Pierre , Ben Rais Lasram Frida , Araignous Emma , Champagnat Juliette , Grusd Samantha , Halouani Ghassen , Hattab Tarek , Leroy Boris , Noguès Quentin , Raoux Aurore , Safi Georges , Niquil Nathalie
Published: March 2021

Climate change is already known to cause irreversible impacts on ecosystems that are difficult to accurately predict due to the multiple scales at which it will interact. Predictions at the community level are mainly focused on the future distribution of marine species biomass using ecological niche modelling, which requires extensive efforts concerning the effects that trophic interactions could have on the realized species dynamics. In this study, a set of species distribution models predictions were used to force the spatially‐explicit trophic model Ecospace in order to evaluate the potentials impacts that two 2,100 climate scenarios, RCP2.6 and RCP8.5, could have on a highly exploited ecosystem, the Bay of Seine (France). Simulations demonstrated that both scenarios would influence the community of the Bay of Seine ecosystem: as expected, more intense changes were predicted with the extreme scenario RCP8.5 than with the RCP2.6 scenario. Under both scenarios, a majority of species underwent a decrease of biomass, although some increased. However, in both cases the stability of the majority of species dynamics was lowered, the sustainability of the fishery. Differences between niche modelling predictions and those obtained through the forcing in Ecospace highlighted the paramount importance of considering trophic interactions in climate change simulations. These results illustrate the requirement of multiplying novel approaches for efficiently forecasting potential impacts of climate change.
Efficacy of bismuth added to standard triple therapy as the first‐line eradication regimen for Helicobacter pylori infection
Authors: Kim Yeon‐Ji , Chung Woo Chul , Kim Dae Bum
Published: March 2021

Background

Addressing the increasing antibiotic resistance, including clarithromycin resistance, which affects Helicobacter pylori eradication therapy, is a challenge for clinicians. The objective of this study was to determine the efficacy of bismuth added to standard triple therapy as a first‐line treatment regimen for Helicobacter pylori infection. The secondary outcome was the treatment efficacy for clarithromycin‐resistant strains.

Material and Methods

A prospective study was undertaken from January to December 2019. A total of 107 patients with Helicobacter pylori infection were enrolled and received Helicobacter pylori eradication therapy with bismuth added to standard triple therapy for 14 days. We also evaluated the clarithromycin resistance rate by dual‐priming oligonucleotide‐based multiplex PCR and treatment efficacy.

Results

A total of 104 patients completed standard triple therapy with bismuth added for Helicobacter pylori eradication. The eradication rates in the intention to treat and per‐protocol analyses were 87.9% and 90.4%, respectively. The frequency of clarithromycin resistance was 33.6% (35/104), and the eradication rate was 77.1% in resistant strains (27/35).

Conclusion

Bismuth added to standard triple therapy could be acceptable as a first‐line treatment regimen for Helicobacter pylori eradication in patients with clarithromycin‐resistant strains. In particular, in areas with high clarithromycin tolerance, it is advisable to consider bismuth add‐on therapy as the first‐line treatment regimen.
The role of a rosette‐shaped plant (Eryngium horridum, Apiaceae) on grassland spiders along a grazing intensity gradient
Authors: da Silva Bomfim Leoni , Bitencourt JoÃo Anacleto Gomez , Rodrigues Everton Nei Lopes , Podgaiski Luciana Regina
Published: March 2021

Rosette‐shaped plants can amplify the diversity of predator arthropods and act as potential shelters for these animals in grassland ecosystems under grazing effect.

Here we evaluated the contribution of a vertical rosette‐shaped plant (Eryngium horridum) to patterns of spider diversity and functional traits in subtropical grasslands under different grazing intensities. We used a common sub‐shrub (Baccharis crispa) and the herbaceous vegetation as reference microhabitats.

Sampling was conducted in 23 plots described according to grazing intensity based on environmental co‐variables. Spiders were sampled with D‐Vac suction within patches of E. horridum, B. crispa, and the herbaceous vegetation.

Compared to the reference microhabitats, E. horridum harboured distinct community composition with a subset of exclusive species, and morphologically adapted spiders.

Spider richness increased in Eryngium plants as grazing pressure increased and the grassland became more simplified. Abundance of runners and space web‐builders responded in a similar fashion, while orb‐web builders were more abundant in E. horridum regardless of grazing intensity.

Our results indicate that these rosette plants positively affect top invertebrate predators, with a special role for sites with high grazing intensities where it promotes microhabitat complexity and aggregates more individuals and species. Thus, grassland management that alter Eryngium's occurrence must be conducted cautiously.
An automated treatment planning strategy for highly noncoplanar radiotherapy arc trajectories
Authors: Carrasqueira P. , Rocha H. , Dias J. M. , Ventura T. , Ferreira B. C. , Lopes M. C.
Published: March 2021

Radiation therapy is a technology‐driven cancer treatment modality that has experienced significant advances over the last decades, due to multidisciplinary contributions that include engineering and computing. Recent technological developments allow the use of noncoplanar volumetric modulated arc therapy (VMAT), one of the most recent photon treatment techniques, in clinical practice. In this work, an automated noncoplanar arc trajectory optimization framework designed in two modular phases is presented. First, a noncoplanar beam angle optimization algorithm is used to obtain a set of noncoplanar irradiation directions. Then, anchored in these directions, an optimization strategy is proposed to compute an optimal arc trajectory. The computational experiments considered a pool of twelve difficult head‐and‐neck tumor cases. It was possible to observe that, for some of these cases, the optimized noncoplanar arc trajectories led to significant treatment planning quality improvements, when compared with coplanar VMAT treatment plans. Although these experiments were done in a research environment treatment planning software (matRad), the conclusions can be of interest for a clinical setting: automated procedures can simplify the current treatment workflow, produce high‐quality treatment plans, making better use of human resources and allowing for unbiased comparisons between different treatment techniques.