1,152 research outputs found

    Academic Self-Efficacy and Undergraduate Research Opportunities Predict Intentions to Pursue Graduate School

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    Students who have undergraduate research opportunities tend to have higher identification as a scientist, also known as science identity. Furthermore, students with higher science identity are better prepared for advanced science education, compared to students with lower science identity. The current studies seek to examine predictors of undergraduate students’ intentions to pursue graduate school. In the first study, underrepresented students in science, technology, engineering, and mathematics (STEM) fields who attended the Annual Biomedical Research Conference for Minority Students (ABRCMS) filled out a survey that assessed their research confidence and intentions to pursue graduate school. Students who attended ABRCMS more often and had higher research confidence from attending were more likely to intend to pursue a research degree in graduate school. In study two, undergraduate students completed a survey with items measuring research confidence, science identity, and academic self-efficacy. All variables significantly predicted students’ intentions of pursuing graduate education, with science identity being the strongest predictor. Results suggest that students’ undergraduate research experiences and ability to view themselves as scientists prepares them for further education and increases their intentions of pursuing graduate education. Exposure to undergraduate research opportunities, like ABRCMS, is especially important in providing underrepresented groups a sense of belonging in STEM fields. Greater sense of belonging and stronger identification with science can increase the number of underrepresented students who pursue STEM fields, which can lead to more advances in science

    Analogies between the crossing number and the tangle crossing number

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    Tanglegrams are special graphs that consist of a pair of rooted binary trees with the same number of leaves, and a perfect matching between the two leaf-sets. These objects are of use in phylogenetics and are represented with straightline drawings where the leaves of the two plane binary trees are on two parallel lines and only the matching edges can cross. The tangle crossing number of a tanglegram is the minimum crossing number over all such drawings and is related to biologically relevant quantities, such as the number of times a parasite switched hosts. Our main results for tanglegrams which parallel known theorems for crossing numbers are as follows. The removal of a single matching edge in a tanglegram with nn leaves decreases the tangle crossing number by at most n3n-3, and this is sharp. Additionally, if γ(n)\gamma(n) is the maximum tangle crossing number of a tanglegram with nn leaves, we prove 12(n2)(1o(1))γ(n)<12(n2)\frac{1}{2}\binom{n}{2}(1-o(1))\le\gamma(n)<\frac{1}{2}\binom{n}{2}. Further, we provide an algorithm for computing non-trivial lower bounds on the tangle crossing number in O(n4)O(n^4) time. This lower bound may be tight, even for tanglegrams with tangle crossing number Θ(n2)\Theta(n^2).Comment: 13 pages, 6 figure

    Nationwide public perceptions regarding the acceptance of using wastewater for community health monitoring in the United States

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    To assess the levels of infection across communities during the coronavirus disease 2019 pandemic, researchers have measured severe acute respiratory syndrome coronavirus 2 RNA in feces dissolved in sewer water. This activity is colloquially known as sewer monitoring and is referred to as wastewater-based epidemiology in academic settings. Although global ethical principles have been described, sewer monitoring is unregulated for health privacy protection when used for public health surveillance in the United States. This study used Qualtrics XM, a national research panel provider, to recruit participants to answer an online survey. Respondents (N = 3,083) answered questions about their knowledge, perceptions of what is to be monitored, where monitoring should occur, and privacy concerns related to sewer monitoring as a public health surveillance tool. Furthermore, a privacy attitude questionnaire was used to assess the general privacy boundaries of respondents. Participants were more likely to support monitoring for diseases (92%), environmental toxins (92%), and terrorist threats (88%; e.g., anthrax). Two-third of the respondents endorsed no prohibition on location sampling scale (e.g., monitoring single residence to entire community was acceptable); the most common location category respondents wanted to prohibit sampling was at personal residences. Sewer monitoring is an emerging technology, and our study sheds light on perceptions that could benefit from educational programs in areas where public acceptance is comparatively lower. Respondents clearly communicated guard rails for sewer monitoring, and public opinion should inform future policy, application, and regulation measures

    Who Publishes in “Predatory” Journals?

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    Many open access journals have a reputation for being of low quality and being dishonest with regard to peer review and publishing costs. Such journals are labeled “predatory” journals. This study examines author profiles for some of these “predatory” journals as well as for groups of more well-recognized open access journals. We collect and analyze the publication record, citation count, and geographic location of authors from the various groups of journals. Statistical analyses verify that each group of journals has a distinct author population. Those who publish in “predatory” journals are, for the most part, young and inexperienced researchers from developing countries. We believe that economic and sociocultural conditions in these developing countries have contributed to the differences found in authorship between “predatory” and “nonpredatory” journals

    Cluster randomized controlled trial protocol: addressing reproductive coercion in health settings (ARCHES)

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    Background\ud Women ages 16–29 utilizing family planning clinics for medical services experience higher rates of intimate partner violence (IPV) and reproductive coercion (RC) than their same-age peers, increasing risk for unintended pregnancy and related poor reproductive health outcomes. Brief interventions integrated into routine family planning care have shown promise in reducing risk for RC, but longer-term intervention effects on partner violence victimization, RC, and unintended pregnancy have not been examined.\ud \ud Methods/Design\ud The ‘Addressing Reproductive Coercion in Health Settings (ARCHES)’ Intervention Study is a cluster randomized controlled trial evaluating the effectiveness of a brief, clinician-delivered universal education and counseling intervention to reduce IPV, RC and unintended pregnancy compared to standard-of-care in family planning clinic settings. The ARCHES intervention was refined based on formative research. Twenty five family planning clinics were randomized (in 17 clusters) to either a three hour training for all family planning clinic staff on how to deliver the ARCHES intervention or to a standard-of-care control condition. All women ages 16–29 seeking care in these family planning clinics were eligible to participate. Consenting clients use laptop computers to answer survey questions immediately prior to their clinic visit, a brief exit survey immediately after the clinic visit, a first follow up survey 12–20 weeks after the baseline visit (T2), and a final survey 12 months after the baseline (T3). Medical record chart review provides additional data about IPV and RC assessment and disclosure, sexual and reproductive health diagnoses, and health care utilization. Of 4009 women approached and determined to be eligible based on age (16–29 years old), 3687 (92 % participation) completed the baseline survey and were included in the sample.\ud \ud Discussion\ud The ARCHES Intervention Study is a community-partnered study designed to provide arigorous assessment of the short (3-4 months) and long-term (12 months) effects of a brief, clinician-delivered universal education and counseling intervention to reduce IPC, RC and unintended pregnancy in family planning clinic settings. The trial features a cluster randomized controlled trial design, a comprehensive data collection schedule and a large sample size with excellent retention.\ud \ud Trial Registration\ud ClinicialTrials.gov NCT01459458. Registered 10 October 2011

    The response of coarse root biomass to long-term CO2 enrichment and nitrogen application in a maturing Pinus taeda stand with a large broadleaved component

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    Elevated atmospheric CO2 (eCO(2)) typically increases aboveground growth in both growth chamber and free-air carbon enrichment (FACE) studies. Here we report on the impacts of eCO(2) and nitrogen amendment on coarse root biomass and net primary productivity (NPP) at the Duke FACE study, where half of the eight plots in a 30-year-old loblolly pine (Pinus taeda, L.) plantation, including competing naturally regenerated broadleaved species, were subjected to eCO(2) (ambient, aCO(2) plus 200 ppm) for 15-17 years, combined with annual nitrogen amendments (11.2 g N m(-2)) for 6 years. Allometric equations were developed following harvest to estimate coarse root (>2 mm diameter) biomass. Pine root biomass under eCO(2) increased 32%, 1.80 kg m(-2) above the 5.66 kg m(-2) observed in aCO(2), largely accumulating in the top 30 cm of soil. In contrast, eCO(2) increased broadleaved root biomass more than twofold (aCO(2): 0.81, eCO(2): 2.07 kg m(-2)), primarily accumulating in the 30-60 cm soil depth. Combined, pine and broadleaved root biomass increased 3.08 kg m(-2) over aCO(2) of 6.46 kg m(-2), a 48% increase. Elevated CO2 did not increase pine root:shoot ratio (average 0.24) but increased the ratio from 0.57 to 1.12 in broadleaved species. Averaged over the study (1997-2010), eCO(2) increased pine, broadleaved and total coarse root NPP by 49%, 373% and 86% respectively. Nitrogen amendment had smaller effects on any component, singly or interacting with eCO(2). A sustained increase in root NPP under eCO(2) over the study period indicates that soil nutrients were sufficient to maintain root growth response to eCO(2). These responses must be considered in computing coarse root carbon sequestration of the extensive southern pine and similar forests, and in modelling the responses of coarse root biomass of pine-broadleaved forests to CO2 concentration over a range of soil N availability.Peer reviewe

    Can screening and brief intervention lead to population-level reductions in alcohol-related harm?

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    A distinction is made between the clinical and public health justifications for screening and brief intervention (SBI) against hazardous and harmful alcohol consumption. Early claims for a public health benefit of SBI derived from research on general medical practitioners' (GPs') advice on smoking cessation, but these claims have not been realized, mainly because GPs have not incorporated SBI into their routine practice. A recent modeling exercise estimated that, if all GPs in England screened every patient at their next consultation, 96% of the general population would be screened over 10 years, with 70-79% of excessive drinkers receiving brief interventions (BI); assuming a 10% success rate, this would probably amount to a population-level effect of SBI. Thus, a public health benefit for SBI presupposes widespread screening; but recent government policy in England favors targeted versus universal screening, and in Scotland screening is based on new registrations and clinical presentation. A recent proposal for a national screening program was rejected by the UK National Health Service's National Screening Committee because 1) there was no good evidence that SBI led to reductions in mortality or morbidity, and 2) a safe, simple, precise, and validated screening test was not available. Even in countries like Sweden and Finland, where expensive national programs to disseminate SBI have been implemented, only a minority of the population has been asked about drinking during health-care visits, and a minority of excessive drinkers has been advised to cut down. Although there has been research on the relationship between treatment for alcohol problems and population-level effects, there has been no such research for SBI, nor have there been experimental investigations of its relationship with population-level measures of alcohol-related harm. These are strongly recommended. In this article, conditions that would allow a population-level effect of SBI to occur are reviewed, including their political acceptability. It is tentatively concluded that widespread dissemination of SBI, without the implementation of alcohol control measures, might have indirect influences on levels of consumption and harm but would be unlikely on its own to result in public health benefits. However, if and when alcohol control measures were introduced, SBI would still have an important role in the battle against alcohol-related harm

    Increasing Engagement in Materials Laboratory with Backward Design and Quadcopters

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    This paper describes a laboratory experiment that was designed to increase student engagement and enhance student development in a materials laboratory. The laboratory module described is part of a broader effort to enhance the mechanical engineering laboratory curriculum to incorporate modern pedagogical methods and to improve student outcomes using backward design. The new laboratory modules encourage students to work in small groups, develop team skills, and learn about basic measurement methods. The first module is a simple cantilever beam mounted with a strain gage. Students develop an understanding of the correlation between bending stress and strain. While doing so, they also determine a calibration factor for the beam in order to use the beam as a load cell to measure the weight of an object. For the second module, students are provided an instrumented beam with a known calibration factor and are asked to determine the amount of lift produced by a small quadcopter. To assess the effectiveness of the laboratory experiment, a student survey was designed and the experiments were observed by an education expert. The results indicate the new laboratory modules have been successful in increasing student engagement and meeting learning objectives

    Cardiorespiratory fitness and preserved medial temporal lobe volume in Alzheimer's Disease

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    This is not the final published version.Exercise and cardiorespiratory (CR) fitness may moderate age-related regional brain changes in nondemented older adults (ND). The relationship of fitness to Alzheimer's disease (AD) related brain change is understudied, particularly in the hippocampus which is disproportionately affected in early AD. The role of apolipoprotein E4 (apoE4) genotype in modulating this relationship is also unknown. Nondemented (n=56) and early-stage AD subjects (n=61) over age 65 had MRI and CR fitness assessments. Voxel-based morphometry (VBM) techniques were utilized to identify AD-related atrophy. We analyzed the relationship of CR fitness with white and gray matter within groups, assessed fitness-related brain volume change in areas most affected by AD-related atrophy, and then analyzed differential fitness-brain relationships between apoE4 carriers. Atrophy was present in the medial temporal, temporal, and parietal cortices in subjects with mild AD. There was a significant positive correlation of CR fitness with parietal and medial temporal volume in AD subjects. ND subjects did not have a significant relationship between brain volume and CR fitness in the global or SVC analyses. There was not a significant interaction for fitness × apoE4 genotype in either group. In early-stage AD, cardiorespiratory fitness is associated with regional brain volumes in the medial temporal and parietal cortices suggesting that maintaining cardiorespiratory fitness may modify AD-related brain atrophy

    Characterization of Glycosylation Profiles of HIV-1 Transmitted/Founder Envelopes by Mass Spectrometry

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    This is the published version, also available here: http://dx.doi.org/10.1128/JVI.05053-11.The analysis of HIV-1 envelope carbohydrates is critical to understanding their roles in HIV-1 transmission as well as in binding of envelope to HIV-1 antibodies. However, direct analysis of protein glycosylation by glycopeptide-based mass mapping approaches involves structural simplification of proteins with the use of a protease followed by an isolation and/or enrichment step before mass analysis. The successful completion of glycosylation analysis is still a major analytical challenge due to the complexity of samples, wide dynamic range of glycopeptide concentrations, and glycosylation heterogeneity. Here, we use a novel experimental workflow that includes an up-front complete or partial enzymatic deglycosylation step before trypsin digestion to characterize the glycosylation patterns and maximize the glycosylation coverage of two recombinant HIV-1 transmitted/founder envelope oligomers derived from clade B and C viruses isolated from acute infection and expressed in 293T cells. Our results show that both transmitted/founder Envs had similar degrees of glycosylation site occupancy as well as similar glycan profiles. Compared to 293T-derived recombinant Envs from viruses isolated from chronic HIV-1, transmitted/founder Envs displayed marked differences in their glycosylation site occupancies and in their amounts of complex glycans. Our analysis reveals that the glycosylation patterns of transmitted/founder Envs from two different clades (B and C) are more similar to each other than they are to the glycosylation patterns of chronic HIV-1 Envs derived from their own clades
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