329 research outputs found

    Specimen Catalog

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    Sexual selection on protamine and transition nuclear protein expression in mouse species

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    Post-copulatory sexual selection in the form of sperm competition is known to influence the evolution of male reproductive proteins in mammals. The relationship between sperm competition and regulatory evolution, however, remains to be explored. Protamines and transition nuclear proteins are involved in the condensation of sperm chromatin and are expected to affect the shape of the sperm head. A hydrodynamically efficient head allows for fast swimming velocity and, therefore, more competitive sperm. Previous comparative studies in rodents have documented a significant association between the level of sperm competition (as measured by relative testes mass) and DNA sequence evolution in both the coding and promoter sequences of protamine 2. Here,we investigate the influence of sexual selection on protamine and transition nuclear protein mRNA expression in the testes of eight mouse species that differ widely in levels of sperm competition.We also examined the relationship between relative gene expression levels and sperm head shape, assessed using geometric morphometrics. We found that species with higher levels of sperm competition express less protamine 2 in relation to protamine 1 and transition nuclear proteins. Moreover, therewas a significant association between relative protamine 2 expression and sperm head shape. Reduction in the relative abundance of protamine 2 may increase the competitive ability of sperm in mice, possibly by affecting sperm head shape. Changes in gene regulatory sequences thus seem to be the basis of the evolutionary response to sexual selection in these proteins. © 2014 The Author(s) Published by the Royal Society. All rights reserved.This work was supported by the Spanish Ministry of Economy and Competitiveness (grant no. CGL2011-26341)Peer Reviewe

    Species differences in egocentric navigation : the effect of burrowing ecology on a spatial cognitive trait in mice

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    This study was funded by start-up funds from Oklahoma State University to P.C.Efficient navigation is a critical component of fitness for most animals. While most species use a combination of allocentric (external) and egocentric (internal) cues to navigate through their environment, subterranean environments present a unique challenge in that visually mediated allocentric cues are unavailable. The relationship between egocentric spatial cognition and species differences in ecology is surprisingly understudied. We used a maze-learning task to test for differences in egocentric navigation between two closely related species of mice, the eastern house mouse, Mus musculus musculus, and the mound-building mouse, Mus spicilegus. The two species are sympatric in Eastern Europe and overlap in summer habitat use but differ dramatically in winter space use: whereas house mice occupy anthropogenic structures, mound-building mice survive the winter underground in intricate burrow systems. Given species differences in burrowing ecology, we predicted that M. spicilegus would learn the maze significantly faster than M. m. musculus when tested in complete darkness, a condition that eliminated allocentric spatial information and served as a proxy for the subterranean environment. We found strong support for this prediction. In contrast, the two species performed equally well when different mice were tested in the same maze with lights on. This context-specific species difference in spatial cognition suggests that enhanced egocentric navigation in M. spicilegus is an adaptation to the burrow systems on which the overwinter survival of young mound-building mice depends. The results of this study highlight the importance of ecological adaptations to the evolution of cognitive traits.PostprintPeer reviewe

    Systems of Support: The Educators with Disabilities Caucus and Its Mentoring Program

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    In the field of education, critics have described the experiences of beginning teaching as “sink or swim, trial by fire, or boot camp experiences.

    Evidence Collection for the Unconscious and Unconsented Patient

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    Forensic nurses are faced with making an ethical decision when an unconscious patient presents with signs of sexual assault. If the patient is unable to consent, the nurses need to decide whether or not to perform a forensic exam. Hospitals have policies in place regarding consent for emergency care, but not all of them consider the collection of forensic evidence. The window of opportunity for forensic collection may disappear before contacts are made or proper consent is established.\ud Ethical, legal, and policy considerations that complicate this scenario are discussed

    Obituary: Thomas Henry Kunz (1938–2020)

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    Dr. Thomas Henry Kunz, an internationally recognized expert on the ecology and behavior of bats and Professor at Boston University, passed away on April 13, 2020 in Dedham, Massachusetts, at the age of 81 as the result of complications from COVID-19. “Tom,” to his many friends and colleagues, was born on June 11, 1938 in Independence, Missouri, to William H. and Edna F. (Dornfeld) Kunz. He married Margaret Louise Brown on December 27, 1962 in Faucett, Missouri, Margaret’s hometown. Two children were born to Margaret and Tom—Pamela Kunz (Jeffrey Kwan) and David Kunz (Nicole, née D’Angelo), and five grandchildren. As a faculty member at Boston University, Tom progressed through the academic ranks becoming an Associate Professor in 1977 and Professor in 1984 in the Department of Biology. Although Kunz made major scientific contributions through his research and administrative leadership, his greatest impact on the future of chiropterology and of science in America may well be through the students whom he trained. He published prolifically--a total of 347 items--including books, book chapters, journal articles, book reviews, project reports, and popular articles. Includes lists of students trained, grants received, and a complete bibliography of published works, as well as a detailed description of his research program

    A Monitoring Instrument for Resilience

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    This document describes a monitoring instrument for efficiently tracking changes in resilience in agricultural initiatives. Operationalizing the concept of resilience (i.e. the ability to withstand change, stresses and shocks) poses significant challenges for project managers, particularly when required for performance reporting. This monitoring instrument aims to balance the demands for tracking and reporting changes in resilience with the scarcity of time and information typical of development initiatives. The instrument can be used to inform decisions on program planning and management where the program goal is to enhance the resilience of communities, to better manage ecosystem services, and to create positive and sustainable development impacts

    Pleistocene Climate, Phylogeny, and Climate Envelope Models: An Integrative Approach to Better Understand Species' Response to Climate Change

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    Mean annual temperature reported by the Intergovernmental Panel on Climate Change increases at least 1.1°C to 6.4°C over the next 90 years. In context, a change in climate of 6°C is approximately the difference between the mean annual temperature of the Last Glacial Maximum (LGM) and our current warm interglacial. Species have been responding to changing climate throughout Earth's history and their previous biological responses can inform our expectations for future climate change. Here we synthesize geological evidence in the form of stable oxygen isotopes, general circulation paleoclimate models, species' evolutionary relatedness, and species' geographic distributions. We use the stable oxygen isotope record to develop a series of temporally high-resolution paleoclimate reconstructions spanning the Middle Pleistocene to Recent, which we use to map ancestral climatic envelope reconstructions for North American rattlesnakes. A simple linear interpolation between current climate and a general circulation paleoclimate model of the LGM using stable oxygen isotope ratios provides good estimates of paleoclimate at other time periods. We use geologically informed rates of change derived from these reconstructions to predict magnitudes and rates of change in species' suitable habitat over the next century. Our approach to modeling the past suitable habitat of species is general and can be adopted by others. We use multiple lines of evidence of past climate (isotopes and climate models), phylogenetic topology (to correct the models for long-term changes in the suitable habitat of a species), and the fossil record, however sparse, to cross check the models. Our models indicate the annual rate of displacement in a clade of rattlesnakes over the next century will be 2 to 3 orders of magnitude greater (430-2,420 m/yr) than it has been on average for the past 320 ky (2.3 m/yr)

    Survival after inflammatory bowel disease-associated colorectal cancer in the Colon Cancer Family Registry

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    AIM: To investigate the survival of individuals with colorectal cancer (CRC) with inflammatory bowel disease (IBD-associated CRC) compared to that of individuals without IBD diagnosed with CRC
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