368 research outputs found
Patterns, causes, and consequences of marine larval dispersal
Quantifying the probability of larval exchange among marine populations is key to predicting local population dynamics and optimizing networks of marine protected areas. The pattern of connectivity among populations can be described by the measurement of a dispersal kernel. However, a statistically robust, empirical dispersal kernel has been lacking for any marine species. Here, we use genetic parentage analysis to quantify a dispersal kernel for the reef fish Elacatinus lori, demonstrating that dispersal declines exponentially with distance. The spatial scale of dispersal is an order of magnitude less than previous estimatesâthe median dispersal distance is just 1.7 km and no dispersal events exceed 16.4 km despite intensive sampling out to 30 km from source. Overlaid on this strong pattern is subtle spatial variation, but neither pelagic larval duration nor direction is associated with the probability of successful dispersal. Given the strong relationship between distance and dispersal, we show that distance-driven logistic models have strong power to predict dispersal probabilities. Moreover, connectivity matrices generated from these models are congruent with empirical estimates of spatial genetic structure, suggesting that the pattern of dispersal we uncovered reflects long-term patterns of gene flow. These results challenge assumptions regarding the spatial scale and presumed predictors of marine population connectivity. We conclude that if marine reserve networks aim to connect whole communities of fishes and conserve biodiversity broadly, then reserves that are close in space (<10 km) will accommodate those members of the community that are short-distance dispersers.We thank Diana Acosta, Alben David, Kevin David, Alissa Rickborn, and Derek Scolaro for assistance with field work; Eliana Bondra for assistance with molecular work; and Peter Carlson for assistance with otolith work. We are grateful to Noel Anderson, David Lindo, Claire Paris, Robert Warner, Colleen Webb, and two anonymous reviewers for comments on this manuscript. This work was supported by National Science Foundation (NSF) Grant OCE-1260424, and C.C.D. was supported by NSF Graduate Research Fellowship DGE-1247312. All work was approved by Belize Fisheries and Boston University Institutional Animal Care and Use Committee. (OCE-1260424 - National Science Foundation (NSF); DGE-1247312 - NSF Graduate Research Fellowship)Published versio
Influence of neighbourhoodâlevel crowding on sleepâdisordered breathing severity: mediation by body size
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/113768/1/jsr12305.pd
An enhanced psychological mindset intervention to promote adolescent wellbeing within educational settings: A feasibility randomized controlled trial
Objective: This randomized controlled trial feasibility study aimed to investigate a singleâsession mindset intervention, incorporating thirdâwave constructs, within educational settings as a universal tool to promote emotional wellbeing. Method: Eighty adolescents (age Mâ=â16.63) were randomized to the 30âmin computer intervention or a usual curriculum waitlist. Outcome measures were administered at baseline, posttreatment, 4âweek, and 8âweek followâups. Results: Student feedback about the intervention and trial procedure was mainly positive. Participants engaged with the intervention content and data were suggestive of possible smallâlarge intervention effects for targeted mechanisms of personality mindset and psychological flexibility. Betweenâgroup differences over time across wellbeing outcomes of selfâcompassion, selfâesteem, low mood, and anxiety also yielded some promising results, though assessments of reliable change were less clear. No harm was reported. Conclusions: The intervention and study design were deemed feasible, though areas for improvement were noted. A fullâscale trial to determine effectiveness is warranted
Frontiers in Pigment Cell and Melanoma Research
We identify emerging frontiers in clinical and basic research of melanocyte
biology and its associated biomedical disciplines. We describe challenges and
opportunities in clinical and basic research of normal and diseased melanocytes
that impact current approaches to research in melanoma and the dermatological
sciences. We focus on four themes: (1) clinical melanoma research, (2) basic
melanoma research, (3) clinical dermatology, and (4) basic pigment cell
research, with the goal of outlining current highlights, challenges, and
frontiers associated with pigmentation and melanocyte biology. Significantly,
this document encapsulates important advances in melanocyte and melanoma
research including emerging frontiers in melanoma immunotherapy, medical and
surgical oncology, dermatology, vitiligo, albinism, genomics and systems
biology, epidemiology, pigment biophysics and chemistry, and evolution
Repressive gene regulation synchronizes development with cellular metabolism
Metabolic conditions affect the developmental tempo of animals. Developmental gene regulatory networks (GRNs) must therefore synchronize their dynamics with a variable timescale. We find that layered repression of genes couples GRN output with variable metabolism. When repressors of transcription or mRNA and protein stability are lost, fewer errors in Drosophila development occur when metabolism is lowered. We demonstrate the universality of this phenomenon by eliminating the entire microRNA family of repressors and find that development to maturity can be largely rescued when metabolism is reduced. Using a mathematical model that replicates GRN dynamics, we find that lowering metabolism suppresses the emergence of developmental errors by curtailing the influence of auxiliary repressors on GRN output. We experimentally show that gene expression dynamics are less affected by loss of repressors when metabolism is reduced. Thus, layered repression provides robustness through error suppression and may provide an evolutionary route to a shorter reproductive cycle
Radiatively driven hypersonic wind tunnel
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/76604/1/AIAA-12568-479.pd
Primary physical education, coaches and continuing professional development
This is an Author's Accepted Manuscript of an article published in Sport, Education and Society, 16(4), 485 - 505, 2011, copyright @ Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/13573322.2011.589645.Physical education (PE) in primary schools has traditionally been taught by qualified primary teachers. More recently, some teaching of PE in primary schools has been undertaken by coaches (mostly football coaches). These coaches hold national governing body awards but do not hold teaching qualifications. Thus, coaches may not be adequately prepared to teach PE in curriculum time. The purpose of this study was to evaluate the perceptions of a group of community-based football coaches working in primary schools for the impact of a Continuing Professional Development (CPD) programme on their ability to undertake âspecified workâ to cover PE in primary schools. The programme focused on four areas identified as important to enable coaches to cover specified work: short- and medium-term planning, pedagogy, knowledge of the curriculum and reflection. Results showed that for the majority of coaches the CPD programme had made them more aware of the importance of these four areas and had helped to develop their knowledge and ability to put this into practice in covering planning, preparation and assessment time. However, further input is still required to develop coachesâ knowledge and understanding in all four areas, but especially their curriculum knowledge, as well as their ability to put these into practice consistently. These findings are discussed in relation to the implications of employing coaches to cover the teaching of PE in primary schools and, if employed, what CPD coaches need to develop the necessary knowledge, skill and understanding for covering specified work in schools
A Self-Consistent Vacuum for Misner Space and the Chronology Protection Conjecture
In this paper we find a self-consistent vacuum for Misner space. For this
"adapted" Rindler vacuum the renormalized stress-energy tensor is zero
throughout the Misner space. A point-like particle detector traveling on a
timelike geodesic in a Misner space with this vacuum detects nothing. Misner
space with this vacuum thus creates no problems for time travel in and of
itself but a time traveler may pose a danger to himself and to the spacetime.Comment: 5 pages, received September 5, 1997, with a note added November 24,
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Evaluating predictive pharmacogenetic signatures of adverse events in colorectal cancer patients treated with fluoropyrimidines
The potential clinical utility of genetic markers associated with response to fluoropyrimidine treatment in colorectal cancer patients remains controversial despite extensive study. Our aim was to test the clinical validity of both novel and previously identified markers of adverse events in a broad clinical setting. We have conducted an observational pharmacogenetic study of early adverse events in a cohort study of 254 colorectal cancer patients treated with 5-fluorouracil or capecitabine. Sixteen variants of nine key folate (pharmacodynamic) and drug metabolising (pharmacokinetic) enzymes have been analysed as individual markers and/or signatures of markers. We found a significant association between TYMP S471L (rs11479) and early dose modifications and/or severe adverse events (adjusted OR = 2.02 [1.03; 4.00], p = 0.042, adjusted OR = 2.70 [1.23; 5.92], p = 0.01 respectively). There was also a significant association between these phenotypes and a signature of DPYD mutations (Adjusted OR = 3.96 [1.17; 13.33], p = 0.03, adjusted OR = 6.76 [1.99; 22.96], p = 0.002 respectively). We did not identify any significant associations between the individual candidate pharmacodynamic markers and toxicity. If a predictive test for early adverse events analysed the TYMP and DPYD variants as a signature, the sensitivity would be 45.5 %, with a positive predictive value of just 33.9 % and thus poor clinical validity. Most studies to date have been under-powered to consider multiple pharmacokinetic and pharmacodynamic variants simultaneously but this and similar individualised data sets could be pooled in meta-analyses to resolve uncertainties about the potential clinical utility of these markers
The ENIGMA Stroke Recovery Working Group: Big data neuroimaging to study brainâbehavior relationships after stroke
The goal of the Enhancing Neuroimaging Genetics through MetaâAnalysis (ENIGMA) Stroke Recovery working group is to understand brain and behavior relationships using wellâpowered metaâ and megaâanalytic approaches. ENIGMA Stroke Recovery has data from over 2,100 stroke patients collected across 39 research studies and 10 countries around the world, comprising the largest multisite retrospective stroke data collaboration to date. This article outlines the efforts taken by the ENIGMA Stroke Recovery working group to develop neuroinformatics protocols and methods to manage multisite stroke brain magnetic resonance imaging, behavioral and demographics data. Specifically, the processes for scalable data intake and preprocessing, multisite data harmonization, and largeâscale stroke lesion analysis are described, and challenges unique to this type of big data collaboration in stroke research are discussed. Finally, future directions and limitations, as well as recommendations for improved data harmonization through prospective data collection and data management, are provided
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