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11.
FRANCISCO PALOMARES JOSÉ ANTONIO GODOY JOSÉ VICENTE LÓPEZ‐BAO ALEJANDRO RODRÍGUEZ SEVERINE ROQUES MIREIA CASAS‐MARCE ELOY REVILLA MIGUEL DELIBES 《Conservation biology》2012,26(4):689-697
Abstract: Theory suggests that demographic and genetic traits deteriorate (i.e., fitness and genetic diversity decrease) when populations become small, and that such deterioration could precipitate positive feedback loops called extinction vortices. We examined whether demographic attributes and genetic traits have changed over time in one of the 2 remaining small populations of the highly endangered Iberian lynx (Lynx pardinus) in Doñana, Spain. From 1983 to 2008, we recorded nontraumatic mortality rates, litter size, offspring survival, age at territory acquisition, and sex ratio. We combined these demographic attributes with measures of inbreeding and genetic diversity at neutral loci (microsatellites) and genes subjected to selection (major histocompatibility complex). Data on demographic traits were obtained through capture and radio tracking, checking dens during breeding, track surveys, and camera trapping. For genetic analyses, we obtained blood or tissue samples from captured or necropsied individuals or from museum specimens. Over time a female‐biased sex ratio developed, age of territory acquisition decreased, mean litter size decreased, and rates of nontraumatic mortality increased, but there were no significant changes in overall mortality rates, standardized individual heterozygosity declined steadily, and allelic diversity of exon 2 of class II major histocompatibility complex DRB genes remained constant (2 allelic variants present in all individuals analyzed). Changes in sex ratio and age of territory acquisition may have resulted from demographic stochasticity, whereas changes in litter size and nontraumatic mortality may be related to observed increases in inbreeding. Concomitant deterioration of both demographic attributes and genetic traits is consistent with an extinction vortex. The co‐occurrence, with or without interaction, of demographic and genetic deterioration may explain the lack of success of conservation efforts with the Doñana population of Iberian lynx. 相似文献
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MarÍA JOSÉ Ruiz‐López Natalia Gañan José Antonio Godoy Ana Del Olmo Julian Garde Gerardo Espeso Astrid Vargas Fernando Martinez Eduardo R. S. Roldán Montserrat Gomendio 《Conservation biology》2012,26(6):1121-1129
The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding‐fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity‐fitness correlations). However, it has been suggested recently that heterozygosity‐fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity‐fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding‐fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding. Correlaciones Heterocigosidad‐ Adaptabilidad y Depresión Endogámica en Dos Especies de Mamíferos Críticamente en Peligro 相似文献
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Raymond Philippe Paul Sylvianne Perron André Bellehumeur Christian Larocque Émilie Charest Hugues 《Food and environmental virology》2022,14(1):40-58
Food and Environmental Virology - Human noroviruses are among the main causes of acute gastroenteritis worldwide. Frozen raspberries have been linked to several norovirus food-related outbreaks.... 相似文献
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The Science of Nature - The Langenberg Quarry near Bad Harzburg has yielded the first Jurassic stem therian mammal of Germany, recovered from Kimmeridgian (Late Jurassic) near shore deposits of a... 相似文献
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RAIMON GUITART RAQUEL CLAVERO RAFAEL MATEO MANUEL MÁÑEZ 《Journal of environmental science and health. Part. B》2013,48(5):753-760
Organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) residue levels were determined in 53 unhatched eggs from greater roseus flamingos (Phoenicopterus ruber). Eggs were collected in 1996 from the National Park of Doñana (Guadalquivir marshes, Southwest Spain), immediately after one breeding colony abandoned the nesting site due to predator attacks. The main metabolite of p,p′-DDT, p,p′-DDE, was the OCP residue found at higher concentrations, with a geometric mean of 721 ng/g wet weight. Residues of other pesticides, including some hexachlorocyclohexane isomers, hexachlorobenzene, aldrin, heptachlor, and heptachlor-epoxide, were detected at much lower concentrations. The sum of PCBs was 528 ng/g, with PCB congeners #187 and #153 being the most prominent in eggs. The pattern observed in these compounds of industrial origin corresponded more to Aroclor 1260 than to any other commercial mixture. Levels of organochlorine residues indicate a medium degree of exposure, and they are not considered of any concern for the flamingo population. In particular, neither p,p′-DDE nor PCB levels were found to be correlated with the eggshell thickness. 相似文献
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Le Bourg E 《Die Naturwissenschaften》2005,92(6):293-296
Previous studies have shown that exposing flies to hypergravity (3g or 5g) for the first 2 weeks of adult life slightly increases longevity of male flies and survival time at 37°C for both sexes, and delays an age-linked behavioral change. The present experiment tested whether the hypergravity could also protect flies from four successive deleterious non-lethal heat shocks at 4 and 5 weeks of age. Males that lived in hypergravity for the first 2 weeks of adult life lived slightly longer (ca. +15% or 1.2 day) after heat shocks (30 min or 45 min at 37°C) than flies that always lived at 1g, but this positive effect of hypergravity was not observed in females. Therefore, hypergravity exposure at young age can help the male flies recovering from a heat shock at older ages. 相似文献
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Éric Montpetit Alexandre Harvey 《Environmental Communication: A Journal of Nature and Culture》2018,12(7):895-910
This article examines the conditions under which environmental beat journalists can gain credibility as expert informants. It shows that media storms foster a particular dynamic that can add to this credibility. Comparing a media storm over shale gas development in Quebec with regular coverage of the same issue in British Columbia, this article shows that the coverage space given to environmental beat journalists during a media storm can render their alliance with protest groups mutually beneficial. Beat journalists can benefit from the willingness of these groups to participate in their stories, while the groups benefit from increased visibility. Beat journalists also benefit by being perceived as expert informants in policy networks, a role that they use to encourage policy-makers to take the concerns of protest groups seriously. This dynamic also increases the negativity of the news coverage. The article makes a contribution to knowledge on the role of environmental journalists in policy-making processes. 相似文献
20.
Éric Darier 《Local Environment》2013,18(1):63-86
Abstract The theoretical concept of ‘governmentality’, as developed by French political theorist Michel Foucault, presents three aspects: (a) an analysis of knowledge, (b) a study of the power effects of normalisation and resistance and (c) the possibility of a non‐essentialist ethic. Governmentality has not yet been applied to environmental issues. First, the concept of governmentality is explained briefly. Then, a detailed case study of the controversy surrounding a proposed municipal incinerator in metropolitan Halifax (Canada) provides an evaluation of the relevance and pertinence of the concept. The case study confirms: (1) the importance of discursive categories in the legitimisation process of local environmental policy; (2) the centrality of the tension between attempts by local authorities to normalise the conduct of the population and resistance presented by environmental groups and individuals; (3) the possibility for groups and individuals to articulate an alternative identity—a Green self—which goes beyond the existing boundaries. 相似文献