77 research outputs found

    Effects of translocation and deer-vehicle collision mitigation on Florida Key deer

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    Urban development and habitat fragmentation threaten recovery and management of the endangered Florida Key deer (Odocoileus virginianus clavium). Urban development has reduced deer dispersal from their core habitat resulting in deer “overabundance” and has increased deer-human interactions (mostly deer-vehicle collisions [DVCs]). Conversely, deer populations on outer islands have declined in recent years due to limited deer dispersal from source populations. In order to expand the Key deer’s range and reduce DVCs within their core habitat, wildlife managers determined translocations and DVC mitigation were needed. Thus, the objectives of my thesis were to determine (1) effects of translocation on the establishment of outer-island local populations, and (2) effects of United States 1 Highway (US 1) improvements (i.e., exclusion fencing, underpasses, deer guards, and extra lane creation) on DVCs and deer movements. I evaluated the efficacy of translocations by comparing annual survival and seasonal ranges between resident and translocated deer and by analyzing reproduction of translocated deer. Translocated females (yearlings and adults) had lower annual survival than resident deer. Conversely, males (yearlings and adults) demonstrated higher annual survival than resident males. Due to low sample sizes and large variation, these numbers are potentially less important than the high overall survival (only 4 of 38 died). Seasonal ranges were generally smaller for resident deer than translocated deer. I attribute differences in ranges to differences in habitat quality between the core habitat and destination islands and to use of soft releases. Presence of fawns and yearlings indicated successful reproduction of translocated deer. Overall, the project was successful in establishing populations on the destination islands. The US 1 Highway improvements reduced DVCs along the fenced section of US 1 (2003, n = 2; 2004, n = 1; 2005, n = 0); however, overall DVCs increased on Big Pine Key (1996–2000, x¯ = 79; 2003, n = 91; 2004, n = 84; 2005, n = 100). Data suggest DVCs shifted to the unfenced segment of US 1. However, monthly deer surveys also suggested an increase in deer numbers that may explain overall DVC increases observed in my study

    Effects of translocation and deer-vehicle collision mitigation on Florida Key deer

    Get PDF
    Urban development and habitat fragmentation threaten recovery and management of the endangered Florida Key deer (Odocoileus virginianus clavium). Urban development has reduced deer dispersal from their core habitat resulting in deer “overabundance” and has increased deer-human interactions (mostly deer-vehicle collisions [DVCs]). Conversely, deer populations on outer islands have declined in recent years due to limited deer dispersal from source populations. In order to expand the Key deer’s range and reduce DVCs within their core habitat, wildlife managers determined translocations and DVC mitigation were needed. Thus, the objectives of my thesis were to determine (1) effects of translocation on the establishment of outer-island local populations, and (2) effects of United States 1 Highway (US 1) improvements (i.e., exclusion fencing, underpasses, deer guards, and extra lane creation) on DVCs and deer movements. I evaluated the efficacy of translocations by comparing annual survival and seasonal ranges between resident and translocated deer and by analyzing reproduction of translocated deer. Translocated females (yearlings and adults) had lower annual survival than resident deer. Conversely, males (yearlings and adults) demonstrated higher annual survival than resident males. Due to low sample sizes and large variation, these numbers are potentially less important than the high overall survival (only 4 of 38 died). Seasonal ranges were generally smaller for resident deer than translocated deer. I attribute differences in ranges to differences in habitat quality between the core habitat and destination islands and to use of soft releases. Presence of fawns and yearlings indicated successful reproduction of translocated deer. Overall, the project was successful in establishing populations on the destination islands. The US 1 Highway improvements reduced DVCs along the fenced section of US 1 (2003, n = 2; 2004, n = 1; 2005, n = 0); however, overall DVCs increased on Big Pine Key (1996–2000, x¯ = 79; 2003, n = 91; 2004, n = 84; 2005, n = 100). Data suggest DVCs shifted to the unfenced segment of US 1. However, monthly deer surveys also suggested an increase in deer numbers that may explain overall DVC increases observed in my study

    The Role of Free-ranging Mammals in the Deposition of Escherichia coli into a Texas Floodplain

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    Free-ranging wildlife are an important contributor of fecal pollution in the form of Escherichia coli (E. coli) to water bodies. Currently, details of this contribution are nebulous and understudied. Much of the related research has not focused on freeranging wildlife; instead investigations examine entire systems while estimating wildlife contribution indirectly or with data of inconsistent quality and source. I began my research by conducting a meta-analysis of existing research to determine the current state of knowledge of wildlife’s specific contribution. Data were sparse, fragmented, of variable quality, and difficult to access. Researchers relied on a variety of outside sources (e.g., state natural resource agencies). Making comparison between studies was nearly impossible because methodologies differed greatly or were described inconsistently. I then calculated wildlife population densities, undertook fecal collection, and conducted spatial analyses of fecal deposition to gather accurate and relevant data of the study area. I augmented field data collection with data derived from my meta-analysis (i.e., fecal deposition rates). I was able to estimate the relative role of individual species (e.g., raccoons [Procyon lotor], white-tailed deer [Odocoileus virginianus], and feral hogs [Sus scrofa]). Finally, I created a model using these data to determine important parameters for future research (e.g., fecal deposition rates) and simulate various management strategies. Although all parameters need more research focus, I found defecation rates were especially important but little researched. I found raccoons were the greatest determiner of potential E. coli load in the floodplain though adjustment of other parameters would greatly impact these findings

    Tolman wormholes violate the strong energy condition

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    For an arbitrary Tolman wormhole, unconstrained by symmetry, we shall define the bounce in terms of a three-dimensional edgeless achronal spacelike hypersurface of minimal volume. (Zero trace for the extrinsic curvature plus a "flare-out" condition.) This enables us to severely constrain the geometry of spacetime at and near the bounce and to derive general theorems regarding violations of the energy conditions--theorems that do not involve geodesic averaging but nevertheless apply to situations much more general than the highly symmetric FRW-based subclass of Tolman wormholes. [For example: even under the mildest of hypotheses, the strong energy condition (SEC) must be violated.] Alternatively, one can dispense with the minimal volume condition and define a generic bounce entirely in terms of the motion of test particles (future-pointing timelike geodesics), by looking at the expansion of their timelike geodesic congruences. One re-confirms that the SEC must be violated at or near the bounce. In contrast, it is easy to arrange for all the other standard energy conditions to be satisfied.Comment: 8 pages, ReV-TeX 3.

    Cognition in chronic kidney disease: a systematic review and meta-analysis

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    Background Cognitive impairment is common in people with chronic kidney disease (CKD) and associated with increased morbidity and mortality. Subtle changes can impact engagement with healthcare, comprehension, decision-making, and medication adherence. We aimed to systematically summarise evidence of cognitive changes in CKD. Methods We searched MEDLINE (March 2016) for cross-sectional, cohort or randomised studies that measured cognitive function in people with CKD (PROSPERO, registration number CRD42014015226). The CKD population included people with eGFR < 60 mL/min/1.73 m2, not receiving renal replacement therapy, in any research setting. We conducted a meta-analysis using random effects, expressed as standardised mean differences (SMD) with 95% confidence intervals (CI). Outcomes were performance in eight cognitive domains. Bias was assessed with the Newcastle-Ottawa Scale (NOS). Results We identified 44 studies reporting sufficient data for synthesis (51,575 participants). Mean NOS score for cohort studies was 5.8/9 and for cross-sectional 5.4/10. Studies were deficient in NOS outcome and selection due to poor methods reporting and in comparison group validity of demographics and chronic disease status. CKD patients (eGFR < 60 mL/min/1.73 m2) performed worse than control groups (eGFR ≥ 60 mL/min/1.73 m2) on Orientation & Attention (SMD –0.79, 95% CI, –1.44 to –0.13), Language (SMD –0.63, 95% CI, –0.85 to –0.41), Concept Formation & Reasoning (SMD –0.63, 95% CI, –1.07 to –0.18), Executive Function (SMD –0.53, 95% CI, –0.85 to –0.21), Memory (SMD –0.48, 95% CI, –0.79 to –0.18), and Global Cognition (SMD –0.48, 95% CI, –0.72 to –0.24). Construction & Motor Praxis and Perception were unaffected (SMD –0.29, 95% CI, –0.90 to 0.32; SMD –1.12, 95% CI, –4.35 to 2.12). Language scores dropped with eGFR (<45 mL/min/1.73 m2 SMD –0.86, 95% CI, –1.25 to –46; 30 mL/min/1.73 m2 SMD –1.56, 95% CI, –2.27 to –0.84). Differences in Orientation & Attention were greatest at eGFR < 45 mL/min/1.73 m2 (SMD –4.62, 95% CI, –4.68 to –4.55). Concept Formation & Reasoning differences were greatest at eGFR < 45 mL/min/1.73 m2 (SMD –4.27, 95% CI, –4.23 to –4.27). Differences in Executive Functions were greatest at eGFR < 30 mL/min/1.73 m2 (SMD –0.54, 95% CI, –1.00 to –0.08). Conclusions Cognitive changes occur early in CKD, and skills decline at different rates. Orientation & Attention and Language are particularly affected. The cognitive impact of CKD is likely to diminish patients’ capacity to engage with healthcare decisions. An individual’s cognitive trajectory may deviate from average

    CC Chemokine Receptor 2 Promotes Recruitment of Myeloid Cells Associated with Insulin Resistance in Non-Alcoholic Fatty Liver Disease

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    Nonalcoholic fatty liver disease (NAFLD) is a common disease, closely associated with obesity and insulin resistance. We investigated the presence of a subset of myeloid cells associated with metabolic disturbance in the liver of patients with NAFLD and a murine model of obesity-induced liver disease. Gene and protein expression in liver and serum was investigated with RT-PCR or ELISA and correlated to clinical disease. Liver-infiltrating immune cells were isolated from normal or diseased human liver for flow cytometric analysis. In animal experiments, mice were fed a high-fat diet (60% of calories from fat) for 16 wk, or high-fat diet with 30% fructose for 32 wk to induce steatohepatitis and fibrosis. A small molecule inhibitor of CC chemokine receptor 2 (CCR2), CCX872, was administered to some mice. A subset of CD11c+CD206+ immune cells was enriched in human liver tissue, and greater infiltration was observed in NAFLD. The presence of CD11c+CD206+ myeloid cells correlated with systemic insulin resistance. CD11c+CD206+ cells expressed high levels of CCR2, and liver CC chemokine ligand 2 (CCL2) expression was increased in nonalcoholic steatohepatitis and correlated with disease activity. In mice, CCR2 inhibition reduced infiltration of liver CD11b+CD11c+F4/80+ monocytes, which are functional homologs of human CD11c+CD206+ cells, and improved liver injury and glycemic control. A role for CCR2/CCL2 in human NAFLD has long been postulated. These data confirm a role for this chemokine/receptor axis, through mediating adipose and hepatic infiltration of myeloid cells. Inhibition of CCR2 improved hepatic inflammation and fibrosis in murine models of NAFLD. These data confirm the rationale for targeting CCR2 to treat NAFLD. NEW &amp; NOTEWORTHY These data show for the first time that CD11c+CD206+ myeloid cells, previously associated with human adipose tissue inflammation, infiltrate into liver tissue in nonalcoholic fatty liver disease. These cells express CCR2. Inhibition of CCR2 in mice inhibits hepatic inflammation caused by a murine homolog of these myeloid cells and improves experimental liver disease. </jats:p
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