1,859 research outputs found
Bidirectional cyclical flows increase energetic costs of station holding for a labriform swimming fish, <i>Cymatogaster aggregata</i>
Why Are Male Social Relationships Complex in the Doubtful Sound Bottlenose Dolphin Population?
Copyright 2008 Elsevier B.V., All rights reserved.Peer reviewedPublisher PD
Gender inequality in science, technology, engineering and mathematics: gendered time disparities in perceived and actual time spent in practical laboratory-based activities
This is the final version. Available on open access from Frontiers Media via the DOI in this recordData availability statement:
The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.Lab-based activities provide essential skills for students within STEM disciplines, as lab activities provide students with research skills and science knowledge. Therefore, it is critical to note that female students have reported feeling less confident in conducting lab-based activities and report a lower sense of belonging in the lab. In two studies (N = 544) we examined gender differences in the time that students spent, and perceived they spent, on various laboratory-based activities. We predicted that female (vs. male) students in science, technology, engineering and mathematics (STEM) would both perceive, and actually spend, less time in practical, science-specific activities, such as using equipment, compared to observing or note-taking. Study 1a (N = 227) was an online, cross-sectional survey where university STEM students reported their perceptions of time spent during lab-based practical activities, and how satisfied they were with their time spent in these activities. Study 1b (N = 318) was an observational study of university practical lab sessions in STEM disciplines. Our findings demonstrated that female (vs. male) students (1) spent more time recording and taking notes during lab sessions, (2) did not perceive, yet actually spent, less time in the lab using equipment, and (3) were equally satisfied with their time in the lab using equipment. Together, these results suggest that women occupy stereotypically gendered roles in the STEM lab, spending less time on activities that are key for their professional development. Furthermore, the fact that students from disciplines with more female participation were more satisfied with their time spent in lab activities can promote the insidious effects of assessing gender participation and equality in STEM through numbers only. The differences in time spent in lab activities-yet the lack of acknowledge of these differences-opens the discussion about how women might be receiving reduced utility from their programmes, and that universities may not be delivering on their obligations to ensure equal access to teaching resource and opportunities
Phylogenetic and phylodynamic approaches to understanding and combating the early SARS-CoV-2 pandemic
Determining the transmissibility, prevalence and patterns of movement of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections is central to our understanding of the impact of the pandemic and to the design of effective control strategies. Phylogenies (evolutionary trees) have provided key insights into the international spread of SARS-CoV-2 and enabled investigation of individual outbreaks and transmission chains in specific settings. Phylodynamic approaches combine evolutionary, demographic and epidemiological concepts and have helped track virus genetic changes, identify emerging variants and inform public health strategy. Here, we review and synthesize studies that illustrate how phylogenetic and phylodynamic techniques were applied during the first year of the pandemic, and summarize their contributions to our understanding of SARS-CoV-2 transmission and control
Social network structure and composition in former NFL football players
Social networks have broad effects on health and quality of life. Biopsychosocial factors may also modify the effects of brain trauma on clinical and pathological outcomes. However, social network characterization is missing in studies of contact sports athletes. Here, we characterized the personal social networks of former National Football League players compared to non-football US males. In 303 former football players and 269 US males, we found that network structure (e.g., network size) did not differ, but network composition (e.g., proportion of family versus friends) did differ. Football players had more men than women, and more friends than family in their networks compared to US males. Black players had more racially diverse networks than White players and US males. These results are unexpected because brain trauma and chronic illnesses typically cause diminished social relationships. We anticipate our study will inform more multi-dimensional study of, and treatment options for, contact sports athletes. For example, the strong allegiances of former athletes may be harnessed in the form of social network interventions after brain trauma. Because preserving health of contact sports athletes is a major goal, the study of social networks is critical to the design of future research and treatment trials
Systematic Review of the Relationships Between Objectively Measured Physical Activity and Health Indicators in School-Aged Children and Youth
Moderate-to-vigorous physical activity (MVPA) is essential for disease prevention and health promotion. Emerging evidence suggests other intensities of physical activity (PA), including light-intensity activity (LPA), may also be important, but there has been no rigorous evaluation of the evidence. The purpose of this systematic review was to examine the relationships between objectively measured PA (total and all intensities) and health indicators in school-aged children and youth. Online databases were searched for peer-reviewed studies that met the a priori inclusion criteria: population (apparently healthy, aged 5–17 years), intervention/exposure/comparator (volumes, durations, frequencies, intensities, and patterns of objectively measured PA), and outcome (body composition, cardiometabolic biomarkers, physical fitness, behavioural conduct/pro-social behaviour, cognition/academic achievement, quality of life/well-being, harms, bone health, motor skill development, psychological distress, self-esteem). Heterogeneity among studies precluded meta-analyses; narrative synthesis was conducted. A total of 162 studies were included (204 171 participants from 31 countries). Overall, total PA was favourably associated with physical, psychological/social, and cognitive health indicators. Relationships were more consistent and robust for higher (e.g., MVPA) versus lower (e.g., LPA) intensity PA. All patterns of activity (sporadic, bouts, continuous) provided benefit. LPA was favourably associated with cardiometabolic biomarkers; data were scarce for other outcomes. These findings continue to support the importance of at least 60 min/day of MVPA for disease prevention and health promotion in children and youth, but also highlight the potential benefits of LPA and total PA. All intensities of PA should be considered in future work aimed at better elucidating the health benefits of PA in children and youth
Level of Recall Bias Regarding Pneumococcal Vaccination History among Adults Hospitalized with Community-Acquired Pneumonia: Results from the University of Louisville Pneumonia Study
Background: Recall bias is likely to occur in vaccine effectiveness studies using self-reported vaccination history. The validity of patient-reported vaccination status for adults is not well defined. The objective of this study was to evaluate the validity of self-reported pneumococcal vaccination history among patients hospitalized with community-acquired pneumonia (CAP).
Methods: Prospective ancillary study of a population-based observational study of hospitalized patients with CAP in the city of Louisville. To be included in the analysis, patients had to (i) be reached by phone 30-days after discharge from the hospital and (ii) report that they remembered whether or not they received a pneumococcal vaccine in the past five years. The vaccination history was classified as 1) Subjective: patient recollection, or 2) Objective: vaccination records from insurance companies or primary care physicians.
Results: A total of 2,787 patients who recalled their vaccination history were included in the analysis. Subjective vaccination history was documented to be inaccurate in 1,023 (37%) patients.
Conclusions: Our study indicates that in adult patients, self-reported data regarding pneumococcal vaccination is likely to be inaccurate in one out of three patients. This level of recall bias may incorporate a fatal flaw in vaccine effectiveness studies
Identifying cell enriched miRNAs in kidney injury and repair
Small noncoding RNAs, miRNAs (miRNAs), are emerging as important modulators in the pathogenesis of kidney disease, with potential as biomarkers of kidney disease onset, progression, or therapeutic efficacy. Bulk tissue small RNA-sequencing (sRNA-Seq) and microarrays are widely used to identify dysregulated miRNA expression but are limited by the lack of precision regarding the cellular origin of the miRNA. In this study, we performed cell-specific sRNA-Seq on tubular cells, endothelial cells, PDGFR-β+ cells, and macrophages isolated from injured and repairing kidneys in the murine reversible unilateral ureteric obstruction model. We devised an unbiased bioinformatics pipeline to define the miRNA enrichment within these cell populations, constructing a miRNA catalog of injury and repair. Our analysis revealed that a significant proportion of cell-specific miRNAs in healthy animals were no longer specific following injury. We then applied this knowledge of the relative cell specificity of miRNAs to deconvolute bulk miRNA expression profiles in the renal cortex in murine models and human kidney disease. Finally, we used our data-driven approach to rationally select macrophage-enriched miR-16-5p and miR-18a-5p and demonstrate that they are promising urinary biomarkers of acute kidney injury in renal transplant recipients
Engineering the isobutanol biosynthetic pathway in Escherichia coli by comparison of three aldehyde reductase/alcohol dehydrogenase genes
Biofuels synthesized from renewable resources are of increasing interest because of global energy and environmental problems. We have previously demonstrated production of higher alcohols from Escherichia coli using a 2-keto acid-based pathway. Here, we have compared the effect of various alcohol dehydrogenases (ADH) for the last step of the isobutanol production. E. coli has the yqhD gene which encodes a broad-range ADH. Isobutanol production significantly decreased with the deletion of yqhD, suggesting that the yqhD gene on the genome contributed to isobutanol production. The adh genes of two bacteria and one yeast were also compared in E. coli harboring the isobutanol synthesis pathway. Overexpression of yqhD or adhA in E. coli showed better production than ADH2, a result confirmed by activity measurements with isobutyraldehyde
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