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991.
Obese Black women are at increased risk for development of gestational diabetes mellitus and have worse perinatal outcomes than do obese women of other ethnicities. Since hsp72 has been associated with the regulation of obesity-induced insulin resistance, we evaluated associations between glucose ingestion, hsp72 release and insulin production in Black pregnant women. Specifically, the effect of a 50-g glucose challenge test (GCT) on heat shock protein and insulin levels in the circulation 1 h later was evaluated. Hsp27 and hsp60 levels remained unchanged. In contrast, serum levels of hsp72 markedly increased after glucose ingestion (p = 0.0054). Further analysis revealed that this increase was limited to women who were not obese (body mass index <30). Insulin levels pre-GCT were positively correlated with body mass index (p = 0.0189). Median insulin concentrations also increased post GCT in non-obese women but remained almost unchanged in obese women. Post-GCT serum hsp72 concentrations were inversely correlated with post GCT insulin concentrations (p = 0.0111). These observations suggest that glucose intake during gestation in Black women rapidly leads to an elevation in circulating hsp72 only in non-obese Black women. The release of hsp72 may regulate the extent of insulin production in response to a glucose challenge and, thereby, protect the mother and/or fetus from development of hyperglycemia, hyperinsulinemia, and/or immune system alterations.  相似文献   
992.
993.
Major disjunctions among marine communities in southeastern Australia have been well documented, although explanations for biogeographic structuring remain uncertain. Converging ocean currents, environmental gradients, and habitat discontinuities have been hypothesized as likely drivers of structuring in many species, although the extent to which species are affected appears largely dependent on specific life histories and ecologies. Understanding these relationships is critical to the management of native and invasive species, and the preservation of evolutionary processes that shape biodiversity in this region. In this study we test the direct influence of ocean currents on the genetic structure of a passive disperser across a major biogeographic barrier. Donax deltoides (Veneroida: Donacidae) is an intertidal, soft‐sediment mollusc and an ideal surrogate for testing this relationship, given its lack of habitat constraints in this region, and its immense dispersal potential driven by year‐long spawning and long‐lived planktonic larvae. We assessed allele frequencies at 10 polymorphic microsatellite loci across 11 sample locations spanning the barrier region and identified genetic structure consistent with the major ocean currents of southeastern Australia. Analysis of mitochondrial DNA sequence data indicated no evidence of genetic structuring, but signatures of a species range expansion corresponding with historical inundations of the Bassian Isthmus. Our results indicate that ocean currents are likely to be the most influential factor affecting the genetic structure of D. deltoides and a likely physical barrier for passive dispersing marine fauna generally in southeastern Australia.  相似文献   
994.
ABSTRACT

Free-roaming cats present a multidisciplinary challenge for wildlife conservation and feline welfare. Veterinary professionals are critical stake-holders in the issue of free-roaming cats, making it imperative that their attitudes and perspectives are well understood. In this study, we conducted an electronic survey of veterinarians practicing across British Columbia to evaluate their perceptions of 1) whether cat overpopulation is a concern, 2) the impacts of cats on wildlife, and 3) alternative management strategies for dealing with cat overpopulation. Of the 389 respondents, 56% agreed that cat overpopulation was a local problem, and 91% agreed that veterinarians play a role in reducing cat overpopulation. Veterinarians in rural communities had a greater involvement in cat overpopulation and perceived it as more problematic than their urban colleagues. The majority (70%) of veterinarians reported that they performed early-age sterilization, supported the principle of low-cost spay-neuter services (67%), and 65% of them were involved in these services. Just over half (54%) of respondents reported that they provide permanent identification to cats, typically offering both microchips and tattoos. Veterinarians were less cohesive on their perceptions of the impact of free-roaming cats on wildlife: 53% agreed that after habitat loss cats are one of the most significant, direct causes of bird and wildlife mortality, while 30% were neutral and 17% disagreed. Fifty-six percent of veterinarians felt that keeping cats indoors would be one of the most effective strategies to reduce cat impacts on wildlife, but they also felt that public education programs and low-cost spay-neuter programs would be effective and more popular with cat owners. Most veterinarians (79%) recommended against unsupervised outdoor access, citing safety and disease risks. Rodent control was the most common reason for not recommending an indoor lifestyle. Overall, our survey results suggest that veterinarians are committed participants in the prevention of cat overpopulation. Conservationists need to focus on increased engagement with veterinarians regarding the impact of cats on wildlife.  相似文献   
995.
Introduction     
Abstrat

In this paper we discuss genetic discourses and practices in stem cell science. We report on how biomedical scientists, in both the UK and the USA, view the scientific literature and their own experimental research in the emerging field of human embryonic stem (hES) cells. We focus on the genetic manipulation of stem cells to make specialized (beta) cells as a potential cure for diabetes. We draw on Gieryn's notion of boundary work as an analytical motif, and suggest this is a productive way to theorize boundary crossings in the shifting landscapes of expectations in the field of new medical technologies. We argue that initial expectations of a revolution in regenerative medicine have been damped down by the difficulties of making insulin producing pancreatic beta cells from stem cells. We contend the consequent shifts in expectations have led to the emergence of other more radical experimental strategies (such as using oncogenes) in the search for potential cures for Type 1 diabetes. In conclusion, we argue that regenerative medicine is a fruitful example of the shaping of contested biomedical landscapes and we contend that embryonic stem cells are a productive case study of the interactions between genetics, science and society.  相似文献   
996.
Preclinical studies of animals with risk factors, and how those risk factors contribute to the development of cardiovascular disease and cardiac dysfunction, are clearly needed. One such approach is to feed mice a diet rich in fat (i.e. 60%). Here, we determined whether a high fat diet was sufficient to induce cardiac dysfunction in mice. We subjected mice to two different high fat diets (lard or milk as fat source) and followed them for over six months and found no significant decrement in cardiac function (via echocardiography), despite robust adiposity and impaired glucose disposal. We next determined whether antecedent and concomitant exposure to high fat diet (lard) altered the murine heart’s response to infarct-induced heart failure; high fat feeding during, or before and during, heart failure did not significantly exacerbate cardiac dysfunction. Given the lack of a robust effect on cardiac dysfunction with high fat feeding, we then examined a commonly used mouse model of overt diabetes, hyperglycemia, and obesity (db/db mice). db/db mice (or STZ treated wild-type mice) subjected to pressure overload exhibited no significant exacerbation of cardiac dysfunction; however, ischemia-reperfusion injury significantly depressed cardiac function in db/db mice compared to their non-diabetic littermates. Thus, we were able to document a negative influence of a risk factor in a relevant cardiovascular disease model; however, this did not involve exposure to a high fat diet. High fat diet, obesity, or hyperglycemia does not necessarily induce cardiac dysfunction in mice. Although many investigators use such diabetes/obesity models to understand cardiac defects related to risk factors, this study, along with those from several other groups, serves as a cautionary note regarding the use of murine models of diabetes and obesity in the context of heart failure.  相似文献   
997.
Species face many threats, including accelerated climate change, sea level rise, and conversion and degradation of habitat from human land uses. Vulnerability assessments and prioritization protocols have been proposed to assess these threats, often in combination with information such as species rarity; ecological, evolutionary or economic value; and likelihood of success. Nevertheless, few vulnerability assessments or prioritization protocols simultaneously account for multiple threats or conservation values. We applied a novel vulnerability assessment tool, the Standardized Index of Vulnerability and Value, to assess the conservation priority of 300 species of plants and animals in Florida given projections of climate change, human land-use patterns, and sea level rise by the year 2100. We account for multiple sources of uncertainty and prioritize species under five different systems of value, ranging from a primary emphasis on vulnerability to threats to an emphasis on metrics of conservation value such as phylogenetic distinctiveness. Our results reveal remarkable consistency in the prioritization of species across different conservation value systems. Species of high priority include the Miami blue butterfly (Cyclargus thomasi bethunebakeri), Key tree cactus (Pilosocereus robinii), Florida duskywing butterfly (Ephyriades brunnea floridensis), and Key deer (Odocoileus virginianus clavium). We also identify sources of uncertainty and the types of life history information consistently missing across taxonomic groups. This study characterizes the vulnerabilities to major threats of a broad swath of Florida’s biodiversity and provides a system for prioritizing conservation efforts that is quantitative, flexible, and free from hidden value judgments.  相似文献   
998.
Healthcare is a critical and complex service sector with direct and indirect greenhouse gas (GHG) emissions amounting to 5%–10% of the national total in developed economies like Canada and the United States. Along with a growing, albeit sporadic, set of life cycle assessment (LCA) (and “carbon footprinting”) studies of specific medical products and procedures, there is growing interest in “environmental footprinting” of hospitals. In this article, we advance this rapidly evolving area through a comprehensive organizational LCA of a 40-bed hospital in British Columbia, Canada, in its 2019 fiscal year. Our results indicate that the total environmental footprint of the hospital includes, among other things, global warming potential of 3500–5000 t CO2 eq. (with 95% confidence). “Hotspots” in this footprint are attributable to energy and water use (and wastewater released), releases of anesthetic gases (which are potent GHGs), and the upstream production of the thousands of materials, chemicals, pharmaceuticals, and other products used in the hospital. The generalizability and comparability of these results are limited by inconsistencies across the few environmental footprinting studies of hospitals conducted to date. Nonetheless, our novel methodological approach, in which we compiled new LCA data for 200 goods and services used in healthcare—strategically selected to statistically represent the 2927 unique products in the hospital's “supply-chains”—has broad applicability in healthcare and beyond.  相似文献   
999.
Thousand Cankers Disease (TCD) affects Juglans and Pterocarya species. This disease poses not only a major threat to the nut and timber industries but also to native stands of walnut trees. Galleries created by Pityophthorus juglandis (vector) are colonized by the fungus Geosmithia morbida (causal agent of necrosis). It is unknown if other fungi colonizing these galleries might act antagonistically towards G. morbida. The objectives of this study were to: (1) characterize the fungal community associated with TCD-infected trees and (2) develop a pilot study addressing their potential antagonism towards G. morbida. We collected non-Geosmithia fungi from ten TCD-infected walnut trees from California and Tennessee. Four hundred and fifty-seven isolates, representing sixty-five Operational Taxonomic Units (99 % ITS similarity) were obtained. Fungal communities were found to be highly diverse. Ophiostoma dominated the communities associated with TCD-compromised trees from California, whereas Trichoderma dominated TCD-compromised trees in Tennessee. Six Trichoderma isolates showed varying levels of antagonism against three isolates of G. morbida, suggesting potential applications for the biological control of TCD. Furthermore, results from this study contribute to the growing knowledge about the observed differential disease development between the western and eastern USA and could overall impact our understanding of TCD etiology.  相似文献   
1000.
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