10 resultados para Escapees
Resumo:
Part 7, joint hearings before the Subcommittee on Health of the Committee on Labor and Public Welfare and the Subcommittee to Investigate Problems Connected with Refugees and Escapees of the Committee on the Judiciary.
Resumo:
1. Deer are of major concern with regards to impacts on biodiversity, forestry and agriculture as well as human health. The invasive Reeves’ muntjac deer Muntiacus reevesi, native to Asia but established in Great Britain, has recently appeared in the wild in Ireland.
2. The first verified record in the wild in Northern Ireland was confirmed during June 2009 as a result of a road traffic accident near Newtownards, Co. Down. The second record was a culled animal shot in the grounds of Mount Stewart, Co. Down during June 2011.
3. The current report aimed to perform a detailed investigation of the most recently obtained animal to establish a) its age, b) its genetic relationship with the first animal and c) the threat it might pose in terms of carrying endo- or ecto-parasites or other micro-pathogens, principally viruses and bacteria.
4. Analysis of its dentition suggested the culled animal was 56 weeks old (range 55-57 weeks).
5. Genetic analysis indicated that there was no possibility of a father-son relationship with the buck killed in 2009. There was a 6.25% probability of both individuals being full-sibs and a 25% probability of a half-sib relationship.
6. The deer was free from all the major pathogens. Most significantly, a novel species of Gammaherpesvirus was detected most closely matching type 2 ruminant rhadinovirus (Gammaherpesvirinae) from mule deer. Further sequencing is required to provide a definitive classification. There is no evidence suggesting this virus is pathogenic but its detection is nonetheless of concern.
7. During late 2009 (after the first animal was recovered) and early 2010, there were a number of sightings of muntjac within the vicinity of Mount Stewart. Our results indicate that the animal shot in June 2011 could not have been this same animal, as the shot animal must have been born in spring 2010. Moreover, genetic analysis indicates that the two recovered individuals were highly unlikely to share the same mother and father, suggesting they were the offspring of a minimum of three breeding adults (two fathers and one mother or two mothers and one father). This brings the total number of known individuals to 5 including the two offspring. The location of the breeding adults is unknown and may be either in captivity with subsequent escapees, or deliberate releases, or be free living in the wild. However, a further sighting during early 2012 may suggest a wild origin.
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Farmed fish are typically genetically different from wild conspecifics. Escapees from fish farms may contribute one-way gene flow from farm to wild gene pools, which can depress population productivity, dilute local adaptations and disrupt coadapted gene complexes. Here, we reanalyse data from two experiments (McGinnity et al., 1997, 2003) where performance of Atlantic salmon (Salmo salar) progeny originating from experimental crosses between farm and wild parents (in three different cohorts) were measured in a natural stream under common garden conditions. Previous published analyses focussed on group-level differences but did not account for pedigree structure, as we do here using modern mixed-effect models. Offspring with one or two farm parents exhibited poorer survival in their first and second year of life compared with those with two wild parents and these group-level inferences were robust to excluding outlier families. Variation in performance among farm, hybrid and wild families was generally similar in magnitude. Farm offspring were generally larger at all life stages examined than wild offspring, but the differences were moderate (5–20%) and similar in magnitude in the wild versus hatchery environments. Quantitative genetic analyses conducted using a Bayesian framework revealed moderate heritability in juvenile fork length and mass and positive genetic correlations (>0.85) between these morphological traits. Our study confirms (using more rigorous statistical techniques) previous studies showing that offspring of wild fish invariably have higher fitness and contributes fresh insights into family-level variation in performance of farm, wild and hybrid Atlantic salmon families in the wild. It also adds to a small, but growing, number of studies that estimate key evolutionary parameters in wild salmonid populations. Such information is vital in modelling the impacts of introgression by escaped farm salmon.
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Growing demands for marine fish products is leading to increased pressure on already depleted wild populations and a rise in aquaculture production. Consequently, more captive-bred fish are released into the wild through accidental escape or deliberate releases. The increased mixing of captive-bred and wild fish may affect the ecological and/or genetic integrity of wild fish populations. Unambiguous identification tools for captive-bred fish will be highly valuable to manage risks (fisheries management) and tracing of escapees and seafood products (wildlife forensics). Using single nucleotide polymorphism (SNP) data from captive-bred and wild populations of Atlantic cod Gadus morhua L. and sole Solea solea L., we explored the efficiency of population and parentage assignment techniques for the identification and tracing of captive-bred fish. Simulated and empirical data were used to correct for stochastic genetic effects. Overall, parentage assignment performed well when a large effective population size characterized the broodstock and escapees originated from early generations of captive breeding. Consequently, parentage assignments are particularly useful from a fisheries management perspective to monitor the effects of deliberate releases of captive-bred fish on wild populations. Population assignment proved to be more efficient after several generations of captive breeding, which makes it a useful method in forensic applications for well-established aquaculture species. We suggest the implementation of a case-by-case strategy when choosing the best method.
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Tese dout., Ciências e Tecnologias das Pescas, Universidade do Algarve, 2009
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The majority of plant species rely, at least partly, on animals for pollination. Our knowledge on whether pollinator visitation differs between native and alien plant species, and between invasive and non-invasive alien species is still limited. Additionally, because numerous invasive plant species are escapees from horticulture, the transition from human-assisted occurrence in urbanized habitats to unassisted persistence and spread in (semi-)natural habitats requires study. To address whether pollinator visitation differs between native, invasive alien and non-invasive alien species, we did pollinator observations for a total of 17 plant species representing five plant families. To test whether pollinator visitation to the three groups of species during the initial stage of invasion depends on habitat type, we did the study in three urbanized habitats and three semi-natural grasslands, using single potted plants. Native plants had more but smaller flower units than alien plants, and invasive alien plants had more but smaller flowers than non-invasive alien plants. After accounting for these differences in floral display, pollinator visitation was higher for native than for alien plant species, but did not differ between invasive and non-invasive alien plant species. Pollinator visitation was on average higher in semi-natural than in urbanized habitats, irrespective of origin or status of the plant species. This might suggest that once an alien species has managed to escape from urbanized into more natural habitats, pollinator limitation will not be a major barrier to establishment and invasion.
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[pt.1]. Hearings held September 28, 1973. -- pt.2. hearings held July 23, 1974. -- pt.3. hearings held October 2, 1975.
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To escape certain death during the Nazi regime, approximately eighty thousand terrorized and persecuted Eastern European Jews sought refuge in the forests surrounding their communities. Most often, their forest deaths were the result of Nazi-sponsored activities such as ghetto deportations and hunts for Jewish escapees. However, anti-Semitic partisans, partisan combat, hostile peasants, and environmental elements were also factors contributing to an estimated ninety percent fatality rate. This dissertation explored the role and meaning of forests to these Jewish fugitives. It investigated the bodily and social practices they developed to enhance their odds of survival in the forest landscape. I develop the concept of landscape agency as a response to my research question: What was it like to live and survive (or die) in the forest during the Holocaust? Moreover, it is an approach to theorizing about the humanity of space. Landscape agency builds upon a phenomenological approach to space and place that links landscape and action through bodily practices. This dissertation analyzed the fugitives' actions as functions of various forms of capital, namely economic, cultural and social. The sample included thirteen individuals who were themselves forest fugitives during the Holocaust. Face-face qualitative interviews were conducted from 2004 to 2006. Primary data from these interviews was used extensively to demonstrate the practices utilized in the fugitives' experiences with life and death in the forest. This study concluded that the odds of survival for forest fugitives were enhanced by use of landscape agency.
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By-catch and discards are a common problem to all fisheries. Recent studies of the Portuguese crustacean-trawl fishery show that discards average 70% of the total catch. This situation poses a threat not only to the management of target and commercial fish by-catch species stocks, but also in terms of the ecosystem impact of the discarded species whose survival is generally low. Previous attempts to address this problem by using oblique separator mesh panels associated with square-mesh windows, or square-mesh windows alone, provided encouraging results, but these are unlikely to have commercial applicability at present. Therefore, we tested the efficiency of a modified Nordmore grid in excluding some of the most captured non-commercial by-catch species, such as the blue whiting, Micromesistius poutassou, and the boarfish, Capros aper, evaluating simultaneously the losses of the crustacean target species (rose shrimp, Parapenaeus longirostris, Norway lobster, Nephrops norvegicus and red shrimp, Aristeus antennatus) and commercially valuable fish by-catch. A total of 41 valid hauls were carried out during 2001, and 15 in 2002 on board the R/V "Noruega". Results from both years varied considerably, with higher by-catch exclusion rates, in weight, registered in the second survey (73-74 and 48-63% for blue whiting and boarfish, respectively). The corresponding percentage reduction for target species was 8-15% for the Norway lobster, 4-9% for rose shrimp and 7-10% for red shrimp. The level of exclusion of the non-commercial by-catch is encouraging, although short-term loss of Norway lobster, where the escapees comprised larger individuals, raises some concern with regards to fishers' acceptance of mandatory use of grids. (C) 2004 Elsevier B.V. All rights reserved.