77 research outputs found
Effects of translocation and deer-vehicle collision mitigation on Florida Key deer
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
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
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
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
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
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 & 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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