990 resultados para Wild turkey


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The degree of genetic and pathologic variation exhibited by a turkey Coronavirus (TCoV) strain was investigated after nine serial passages in 25-day-old turkey embryos obtained from wild broad-breasted bronze breeders. In spite of spleen, liver, kidneys, cloacal bursa and thymus have been collected and analysed, the main histopathological changes were only documented in the intestine sections. Microscopic lesions were characterized as mild enteritis, low degree of enterocyte vacuolization and detachment of the intestinal villous after five consecutive passages and were considered absent in the last passages. Genealogic analysis based on S1 and S2 DNA sequences suggested that Brazilian isolate might be considered as originated from TCoV strains circulating in the United States, as 100% identity with TCoV-Gl strain. Although S1 S2 sequences from each passage revealed no significant point mutations, and no correlation could be speculate between S2 nucleotide changes and pathologic features in infected embryos. This is the first demonstration of wild turkey embryos as a model for TCoV isolation and propagation.

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Bibliography: p. 28.

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"This publication is a contribution of the Virginia Commission of Game and Inland Fisheries (Pittman-Robertson Projects, Division of Game) and the Virginia Cooperative Wildlife Research Unit, cooperating." - prelim. p. iv.

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"April 2000."

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Les changements climatiques récents ont mené à l’expansion de la répartition de plusieurs espèces méridionales, mais ont aussi causé l’extinction locale d’espèces se retrouvant à la limite de leur tolérance environnementale. Ces populations en expansion peuvent favoriser différentes stratégies d’histoire de vie en répondant à différents facteurs limitants. Dans cette thèse, je vise à déterminer et quantifier l’effet du climat et des évènements extrêmes sur le cycle de vie complet d’une espèce en expansion (le dindon sauvage) pour comprendre les changements au niveau populationnel ainsi que les mécanismes impliqués dans l’expansion de la distribution d’une espèce. J’ai défini les évènements extrêmes de pluie, d’épaisseur de neige au sol et de température, comme un évènement dont la fréquence est plus rare que le 10e et 90e percentile. En utilisant l’approche « Measure-Understand-Predict » (MUP), j’ai tout d’abord suivi trois populations le long d’un gradient latitudinal de sévérité hivernale pour mesurer l’effet de variables météorologiques sur la dynamique des populations. La survie des dindons sauvages diminuait drastiquement lorsque l’accumulation de neige au sol dépassait 30 cm pour une période de 10 jours et diminuait également avec la température. Au printemps, la persistance de la neige affectait négativement le taux d’initiation de la nidification et l’augmentation de la pluie diminuait la survie des nids. Dans une deuxième étape, j’ai examiné l’impact des évènements climatiques extrêmes et des processus démographiques impliqués dans l’expansion du dindon, liés à la théorie des histoires de vie pour comprendre la relation entre la dynamique de ces populations en expansions avec le climat. J’ai démontré que la fréquence des évènements extrêmes hivernaux et, d’une façon moins importante, les évènements extrêmes estivaux limitaient l’expansion nordique des dindons sauvages. J’ai appuyé, à l’aide de données empiriques et de modélisation, les hypothèses de la théorie classique des invasions biologiques en montrant que les populations en établissement priorisaient les paramètres reproducteurs tandis que la survie adulte était le paramètre démographique affectant le plus la dynamique des populations bien établies. De plus, les populations les plus au nord étaient composées d’individus plus jeunes ayant une espérance de vie plus faible, mais avaient un potentiel d’accroissement plus élevé que les populations établies, comme le suggère cette théorie. Finalement, j’ai projeté l’impact de la récolte sur la dynamique des populations de même que le taux de croissance de cette espèce en utilisant les conditions climatiques futures projetées par les modèles de l’IPCC. Les populations en établissement avaient un taux de récolte potentiel plus élevé, mais la proportion de mâles adultes, possédant des caractéristiques recherchées par les chasseurs, diminuait plus rapidement que dans les populations établies. Dans le futur, la fréquence des évènements extrêmes de pluie devrait augmenter tandis que la fréquence des évènements extrêmes de température hivernale et d’accumulation de neige au sol devraient diminuer après 2060, limitant probablement l’expansion nordique du dindon sauvage jusqu’en 2100. Cette thèse améliore notre compréhension des effets météorologiques et du climat sur l’expansion de la répartition des espèces ainsi que les mécanismes démographiques impliqués, et nous a permis de prédire la probabilité de l’expansion nordique de la répartition du dindon sauvage en réponse aux changements climatiques.

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Connections between earth science and communities are not clear to many communities. This talk explores the geologic setting, the infrastructural damage, and the impact on communities of recent large earthquakes in Taiwan, Turkey, Haiti and Japan. Decisions made about geologic hazards had a profound impact on human life and the built environment. Ridgway shares how Purdue is building connections between the scientific community and Native American communities—especially by engaging Native American students in research on tribal lands.

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Full analysis of eight seed samples collected in the 1960's excavations at Neolithic Catalhoyuk East, Turkey, is presented. Detailed investigation of the composition and context of the samples suggests that the Neolithic population collected, processed and stored seeds from Capsella sp. and Descurainia sp. (wild crucifers) for food use. In addition seeds of Vicia/Lathyrus sp. (wild vetch), Helianthemum spp. and Taeniatherum caput-medusae mixed with Eremopyrum type (grasses) were also found, some of which may have been used for food or other purposes. The analysis demonstrates that wild seed exploitation was a regular part of subsistence practice alongside the economic staple of crop production, and again demonstrates how diverse plant use practices were at the site.

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This paper assesses the status of pre-disaster risk management in the case of Turkey. By focusing on the period following the catastrophic August 17, 1999 earthquake, the study benefits from USAID’s Disaster Risk Management Benchmarking Tool (DRMBT). In line with the benchmarking tool, the paper covers key developments in the four components of pre-disaster risk management, namely: risk identification, risk mitigation, risk transfer and disaster preparedness. In the end, it will present three major conclusions: (i) Although post-1999 Turkey has made some important progress in the pre-disaster phase of DRM, particularly with the enactment of obligatory earthquake insurance and tightened standards for building construction, the country is far away from substantial levels of success in DRM. (ii) In recent years, local governments have had been given more authority in the realm of DRM, however, Turkey’s approach to DRM is still predominantly centralized at the expense of successful DRM practices at the local level. (iii) While the devastating 1999 earthquake has resulted in advances in the pre-disaster components of DRM; progress has been mostly in the realm of earthquakes. Turkey’s other major disasters (landslides, floods, wild fires i.e.) also require similar attention by local and central authorities.

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The mud crab (Scylla spp.) aquaculture industry has expanded rapidly in recent years in many countries in the Indo - West Pacific (IWP) region as an alternative to marine shrimp culture because of significant disease outbreaks and associated failures of many shrimp culture industries in the region. Currently, practices used to produce and manage breeding crabs in hatcheries may compromise levels of genetic diversity, ultimately compromising growth rates, disease resistance and stock productivity. Therefore, to avoid “genetic pollution” and its harmful effects and to promote further development of mud crab aquaculture and fisheries in a sustainable way, a greater understanding of the genetic attributes of wild and cultured mud crab stocks is required. Application of these results can provide benefits for managing wild and cultured Asian mud crab populations for multiple purposes including for commercial production, recreation and conservation and to increase profitability and sustainability of newly emerging crab culture industries. Phylogeographic patterns and the genetic structure of Asian mud crab populations across the IWP were assessed to determine if they were concordant with those of other widespread taxa possessing pelagic larvae of relatively long duration. A 597 bp fragment of the mitochondrial DNA COI gene was amplified and screened for variation in a total of 297 individuals of S. paramamosain from six sampling sites across the species’ natural geographical distribution in the IWP and 36 unique haplotypes were identified. Haplotype diversities per site ranged from 0.516 to 0.879. Nucleotide diversity estimates among haplotypes were 0.11% – 0.48%. Maximum divergence observed among S. paramamosain samples was 1.533% and samples formed essentially a single monophyletic group as no obvious clades were related to geographical location of sites. A weak positive relationship was observed however, between genetic distance and geographical distance among sites. Microsatellite markers were then used to assess contemporary gene flow and population structure in Asian mud crab populations sampled across their natural distribution in the IWP. Eight microsatellite loci were screened in sampled S. paramamosain populations and all showed high allelic diversity at all loci in sampled populations. In total, 344 individuals were analysed, and 304 microsatellite alleles were found across the 8 loci. The mean number of alleles per locus at each site ranged from 20.75 to 28.25. Mean allelic richness per site varied from 17.2 to 18.9. All sites showed high levels of heterozygosity as average expected heterozygosities for all loci ranged from 0.917 – 0.953 while mean observed heterozygosity ranged from 0.916 – 0.959. Allele diversities were similar at all sites and across all loci. The results did not show any evidence for major differences in allele frequencies among sites and patterns of allele frequencies were very similar in all populations across all loci. Estimates of population differentiation (FST) were relatively low and most probably largely reflect intra – individual variation for very highly variable loci. Results from nDNA analysis showed evidence for only very limited population genetic structure among sampled S. paramamosain, and a positive and significant association for genetic and geographical distance among sample sites. Microsatellite markers were then employed to determine if adequate levels of genetic diversity has been captured in crab hatcheries for the breeding cycle. The results showed that all microsatellite loci were polymorphic in hatchery samples. Culture populations were in general, highly genetically depauperate, compared with comparable wild populations, with only 3 to 8 alleles recorded for the same loci set per population. In contrast, very high numbers of alleles per locus were found in reference wild S. paramamosain populations, which ranged from 18 to 46 alleles per locus per population. In general, this translates into a 3 to 10 fold decline in mean allelic richness per locus in all culture stocks compared with wild reference counterparts. Furthermore, most loci in all cultured S. paramamosain samples showed departures from HWE equilibrium. Allele frequencies were very different in culture samples from that present in comparable wild reference samples and this in particular, was reflected in a large decline in allele diversity per locus. The pattern observed was best explained by significant impacts of breeding practices employed in hatcheries rather than natural differentiation among wild populations used as the source of brood stock. Recognition of current problems and management strategies for the species both for the medium and long-term development of the new culture industry are discussed. The priority research to be undertaken over the medium term for S. paramamosain should be to close the life cycle fully to allow individuals to be bred on demand and their offspring equalised to control broodstock reproductive contributions. Establishing a broodstock register and pedigree mating system will be required before any selection program is implemented. This will ensure that sufficient genetic variation will be available to allow genetic gains to be sustainably achieved in a future stock improvement program. A fundamental starting point to improve hatchery practices will be to encourage farmers and hatchery managers to spawn more females in their hatcheries as it will increase background genetic diversity in culture stocks. Combining crablet cohorts from multiple hatcheries into a single cohort for supply to farmers or rotation of breeding females regularly in hatcheries will help to address immediate genetic diversity problems in culture stocks. Application of these results can provide benefits for managing wild and cultured Asian mud crab populations more efficiently. Over the long-term, application of data on genetic diversity in wild and cultured stocks of Asian mud crab will contribute to development of sustainable and productive culture industries in Vietnam and other countries in the IWP and can contribute towards conservation of wild genetic resources.

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Abstract During a survey of faba bean viruses in West Asia and North Africa a virus was identified as broad bean stain virus (BBSV) based on host reactions, electron microscopy, physical properties and serology. An antiserum to a Syrian isolate was prepared. With this antiserum both the direct double antibody sandwich ELISA (DAS-ELISA) and dot-ELISA were very sensitive in detecting BBSV in leaf extracts, ground whole seeds and germi nated embryos. Sens it i vity was not reduced when the two-day procedure was replaced by a one-day procedure. us i ng ELISA the vi rus was detected in 73 out of 589 faba bean samples with virus-like symptoms collected from Egypt (4 out of 70 samples tested), Lebanon (6/44) , Morocco (017), Sudan (19/254), Syria (36/145) and Tunisia (8/69). This is the first report of BBSV infection of faba bean in Lebanon, Sudan, Syria and Tunisia. speci es i ndi genous to Syri a were Fourteen wild legume susceptible to BBSV infection, with only two producing obvious symptoms. The virus was found to be seed transmitted ~n Vicia palaestina.