714 research outputs found

    Assessing the potential impacts of a changing climate on the distribution of a rabies virus vector

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    Common vampire bats (Desmodus rotundus) occur throughout much of South America to northern MeÂxico. Vampire bats have not been documented in recent history in the United States, but have been documented within about 50 km of the U.S. state of Texas. Vampire bats feed regularly on the blood of mammals and can transmit rabies virus to native species and livestock, causing impacts on the health of prey. Thus cattle producers, wildlife management agencies, and other stakeholders have expressed concerns about whether vampire bats might spread into the southern United States. On the other hand, concerns about vampire- borne rabies can also result in wanton destruction at bat roosts in areas occupied by vampire bats, but also in areas not known to be occupied by this species. This can in turn negatively affect some bat roosts, populations, and species that are of conservation concern, including vampire bats. To better understand the current and possible future distribution of vampire bats in North America and help mitigate future cattle management problems, we used 7,094 vampire bat occurrence records from North America and species distribution modeling (SDM) to map the potential distribution of vampire bats in North America under current and future climate change scenarios. We analysed and mapped the potential distribution of this species using 5 approaches to species distribution modeling: logistic regression, multivariate adaptive regression splines, boosted regression trees, random forest, and maximum entropy. We then projected these models into 17 ªworst-caseº future climate scenarios for year 2070 to generate hypotheses about how the vampire bat distribution in North America might change in the future. Of the variables used in this analysis, minimum temperature of the coldest month had the highest variable importance using all 5 SDM approaches. These results suggest two potential near-future routes of vampire bat dispersal into the U. S., one via southern Texas, and a second into southern Florida. Some of our SDM models support the hypothesis that suitable habitat for vampire bats may currently exist in parts of the Mexico-U.S. borderlands, including extreme southern portions of Texas, as well as in southern Florida. However, this analysis also suggests that extensive expansion into the south-eastern and south-western U.S. over the coming ~60 years appears unlikely

    PHYLOGENETIC AND POPULATION GENETIC ASSESSMENT OF RAFINESQUE’S BIG-EARED BAT (\u3ci\u3eCORYNORHINUS RAFINESQUII\u3c/i\u3e)

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    Rafinesque’s big-eared bat (Corynorhinus rafinesquii) is distributed across the Southeastern United States. Due to habitat loss and low population numbers, this species is a Federal species of concern and protected by every State within its range. Effective management of any species of concern is dependent on an unambiguous understanding of taxonomic relationships. However, for this species, there are discordant inferences about subspecific designations from previous studies. Further, there have been no assessments of population genetic status for this species. Such assessments could provide information on genetic diversity and population connectivity and increase our understanding of the need for management and conservation of this species. Therefore, our goals were to assess population level genetic diversity and connectivity among 5 colonies in Arkansas (139 individuals) and to infer the evolutionary relationships of these bats to C. rafinesquii collected across its distribution (additional 216 individuals). We used mitochondrial DNA control region sequences and 11 microsatellite loci to infer genetic relationships, estimate levels of genetic diversity, and examine population connectivity among 5 colonies in Arkansas. Although we identified two phylogenetically divergent mitochondrial DNA lineages, these correspond to neither current subspecific designation nor nonoverlapping geographical groups. Genetic diversity and population connectivity estimated from mitochondrial DNA was high in Arkansas populations probably due to occurrence of both evolutionary lineages within each colony. However, estimates from microsatellite DNA of genetic diversity, population connectivity, and effective population sizes in these populations were low. Further, our results suggested a weak signal of population bottleneck in Arkansas colonies and low genetic connectivity. Current conservation efforts should continue to focus on protection of roosts and improvement of habitat corridors to connect populations

    Genetic Analysis of Population Dynamics of the Southeastern Coyote (Canis latrans)

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    Coyotes (Canis latrans) have been extremely successful in dispersing and expanding their range that now includes all fifty states of the United States in addition to Canada and parts of Central America. These animals have generally been considered a pest species due to their adaptive ability, high reproductivity, and impact as a top predator on commercial agricultural business. Population dynamics of coyotes is still poorly understood, yet such knowledge would be beneficial to management of coyotes in all areas. The goal of this study is to determine population structure in Alabama by using microsatellite DNA markers. In addition we plan to examine patterns of gene flow across an urban to rural gradient. This research is extremely applicable in urban coyote management as we will be able to describe gene flow between and among population of coyotes. Information gained about population structure among coyotes in east-central Alabama could be informative about populations across the southeastern region. It is our expectation that such biological data will be consolidated with the vast knowledge of the ecology of the southeastern coyote gathered to date to inform and aid management plans and decisions across the region. Approaching both conservation and management issues with a more unbiased view of the ecology of coyote populations will allow greater effectiveness in management practices for this species

    Using Genetics to Assess Differentiation Among Raccoons in an Area with Variable Rabies Status in Alabama

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    The western spread of raccoon rabies in Alabama has been slow and even appears to regress eastward periodically. While the disease has been present in the state for over 30 years, areas in northwest Alabama are devoid of raccoon rabies. This variation resulting in an enzootic area of raccoon rabies primarily in southeastern Alabama may be due to landscape features that hinder the movement of raccoons (i.e., gene flow) among different locations. We used 11 raccoon-specific microsatellite markers to obtain individual genotypes to examine gene flow among areas that were rabies free, enzootic with rabies, or had only sporadic reports of the disease. Samples from 70 individuals were collected from 5 sampling localities in 3 counties. The landscape feature data were collected from geographic information system (GIS) data. We inferred gene flow by estimating FST and by using Bayesian tests to identify genetic clusters. Estimates of pairwise FST indicated genetic differentiation and restricted gene flow between some sites, and an uneven distribution of genetic clusters was observed. Of the landscape features examined (i.e., land cover, elevation, slope, roads, and hydrology), only land cover had an association with genetic differentiation, suggesting this landscape variable may affect gene flow among raccoon populations and thus the spread of raccoon variant of rabies in Alabama

    Comparison of the collagen haemostat Sangustop(R) versus a carrier-bound fibrin sealant during liver resection; ESSCALIVER-study

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    Background: Haemostasis in liver surgery remains a challenge despite improved resection techniques. Oozing from blood vessels too small to be ligated necessitate a treatment with haemostats in order to prevent complications attributed to bleeding. There is good evidence from randomised trials for the efficacy of fibrin sealants, on their own or in combination with a carrier material. A new haemostatic device is Sangustop(R). It is a collagen based material without any coagulation factors. Pre-clinical data for Sangustop(R) showed superior haemostatic effect. This present study aims to show that in the clinical situation Sangustop(R) is not inferior to a carrier-bound fibrin sealant (Tachosil(R)) as a haemostatic treatment in hepatic resection. Methods: This is a multi-centre, patient-blinded, intra-operatively randomised controlled trial. A total of 126 patients planned for an elective liver resection will be enrolled in eight surgical centres. The primary objective of this study is to show the non-inferiority of Sangustop(R) versus a carrier-bound fibrin sealant (Tachosil(R)) in achieving haemostasis after hepatic resection. The surgical intervention is standardised with regard to devices and techniques used for resection and primary haemostasis. Patients will be followed-up for three months for complications and adverse events. Discussion: This randomised controlled trial (ESSCALIVER) aims to compare the new collagen haemostat Sangustop(R) with a carrier-bound fibrin sealant which can be seen as a "gold standard" in hepatic and other visceral organ surgery. If non-inferiority is shown other criteria than the haemostatic efficacy (e.g. costs, adverse events rate) may be considered for the choice of the most appropriate treatment. Trial Registration: NCT0091861

    EVIDENCE OF TWO COCIRCULATING CANINE DISTEMPER VIRUS STRAINS IN MESOCARNIVORES FROM NORTHERN COLORADO, USA

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    Canine distemper virus (CDV) is a highly contagious pathogen that principally infects wildlife and domestic carnivores. Peridomestic species such as raccoons (Procyon lotor) experience outbreaks with high mortality. Clinical signs of infection include anorexia, fever, respiratory infection, and neurologic complications. Although not zoonotic, CDV poses a high risk to unvaccinated domestic animals and the conservation of endangered species. During 2013–16, we opportunistically collected wild and domestic carnivore specimens through a rabies surveillance program in northern Colorado, US. Brainstem and cerebellar tissue samples were independently tested for rabies and CDV by fluorescent antibody test. We tested a total of 478 animals for CDV, comprised of 10 wild and domestic carnivore species. A total of 15% (72/478) of all animals sampled tested positive for CDV, consisting of 24% (71/300) of raccoons and 4% (1/26) of coyotes (Canis latrans), but coinfection with rabies virus was not observed among CDV-positive animals. We extracted RNA from positive tissues, and a reverse-transcription PCR was used to create complementary DNA. We amplified and sequenced the hemagglutinin gene from 60 CDV-positive tissues, and a median joining network and maximum likelihood phylogenetic tree revealed two major lineages among samples. Phylogenetic analysis indicated that our sequences were most similar to the America-2 (n=55) and the America-3 (n=5) CDV lineages circulating in North America. Our results indicated two distinct and distantly related clades of CDV overlapping geographically and temporally among raccoon populations in northern Colorado

    Ruminal in vitro fermentation kinetics and chemical composition of Sorghum cv. Nutritop at different stage of regrowth.

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    The objective was to estimate the ruminal degradation kinetics and chemical composition of Sorghum cv. Nutritop at different stages of regrowth, as fed for background lambs

    Landscape Genetics of Raccoons (\u3ci\u3eProcyon lotor\u3c/i\u3e) Associated with Ridges and Valleys of Pennsylvania: Implications for Oral Rabies Vaccination Programs

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    Raccoons are the reservoir for the raccoon rabies virus variant in the United States. To combat this threat, oral rabies vaccination (ORV) programs are conducted in many eastern states. To aid in these efforts, the genetic structure of raccoons (Procyon lotor) was assessed in southwestern Pennsylvania to determine if select geographic features (i.e., ridges and valleys) serve as corridors or hindrances to raccoon gene flow (e.g., movement) and, therefore, rabies virus trafficking in this physiographic region. Raccoon DNA samples (n = 185) were collected from one ridge site and two adjacent valleys in southwestern Pennsylvania (Westmoreland, Cambria, Fayette, and Somerset counties). Raccoon genetic structure within and among these study sites was characterized at nine microsatellite loci. Results indicated that there was little population subdivision among any sites sampled. Furthermore, analyses using a model-based clustering approach indicated one essentially panmictic population was present among all the raccoons sampled over a reasonably broad geographic area (e.g., sites up to 36 km apart). However, a signature of isolation by distance was detected, suggesting that widths of ORV zones are critical for success. Combined, these data indicate that geographic features within this landscape influence raccoon gene flow only to a limited extent, suggesting that ridges of this physiographic system will not provide substantial long-term natural barriers to rabies virus trafficking. These results may be of value for future ORV efforts in Pennsylvania and other eastern states with similar landscapes

    Vigilancia epidemiológica en mujeres embarazadas para control de riesgos en el consumo de tabaco en la ciudad de Gualeguaychú

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    Objetivo: Determinar el nivel de cotinina urinaria en embarazadas fumadoras activas y pasivas en centros de salud públicos (cpub) y privados (cpri) de Gualeguaychú para conocer su riesgo de exposición y contribuir a mejorar el diseño de las intervenciones en la prevención del hábito tabáquico durante el embarazo. Materiales y métodos: Se trabajó con 443 embarazadas que concurrieron a cpub y cpri de Gualeguaychú para su control prenatal, solicitándoles a las que manifestaron ser fumadoras activas o estar expuestas al hat una muestra de orina para el dosaje de cotinina. Se aplicó un diseño de tipo no experimental, retrospectivo y de corte transversal. El dosaje de cotinina se realizó en orina, empleando una metodología quimioluminiscente. Previamente se obtuvo un valor referencial de cotinina urinaria inferior a los 15,2 ng/ml para el 98 % de sujetos no fumadores no expuestos al hat. Resultados: El 97,3 % de las embarazadas que declararon ser fumadoras activas presentaron valores de cotinina superiores a los 100 ng/ml y el 66,2 % de las que expresaron ser fumadoras pasivas presentaron un nivel superior a 15,2 ng/ml. Discusión y conclusiones: Los resultados obtenidos demuestran la utilidad de la cotinina como indicador para obtener datos fidedignos frente a la exposición al tabaco
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