159 research outputs found
Testing for Geographic Variation in Survival of Spectacled Eider (Somateria fischeri) Populations in Chukotka, Russia and the Yukon-Kuskokwim Delta, Alaska
Information on variation in survival among geographically distinct breeding populations can produce valuable insights about the population dynamics of a species. The Yukon-Kuskokwim Delta sub-population of Spectacled Eiders in Alaska decreased precipitously between the 1950s and 1990s. Causes for this decline are unknown but may be attributed to low female survival due to predation and lead exposure on the breeding grounds. From 2014 to 2015, we compared annual survival probabilities of Spectacled Eiders on Kigigak Island in the Yukon-Kuskokwim Delta, Alaska, and Ayopechan Island in the Chaun Delta, Chukotka, where similar field protocols were implemented. A Cormack-Jolly-Seber maximum likelihood approach was used to estimate apparent survival (φ) and recapture probability (p) from mark-resight data. We tested a) whether Russian and Alaskan sub-populations differed in their survival rates, b) whether survival varied annually, and c) whether survival followed an increasing or decreasing trend over time at either site. We found no evidence for differing survival between the two breeding areas when mean survival across years was compared, and we did not find strong evidence for a linear trend in survival over time at either site. Furthermore, our data supported models with annually varying survival at Kigigak Island and constant survival at Ayopechan Island. Sample size constraints precluded estimates of annual survival at Ayopechan Island. Our finding of no difference in mean survival between sites lends support to the idea that survival may be a function of conditions on the wintering grounds.Les données en matière de variations de survie chez des populations nicheuses géographiquement distinctes peuvent donner un précieux aperçu de la dynamique des populations d’une espèce. La sous-population d’eiders à lunettes du delta Yukon-Kuskokwim, en Alaska, a chuté abruptement entre les années 1950 et les années 1990. Nul ne connaît les causes de ce déclin, mais elles pourraient être attribuables au faible taux de survie des femelles en lien avec la prédation et l’exposition au plomb dans les aires de reproduction. De 2014 à 2015, nous avons comparé les probabilités de survie annuelle des eiders à lunettes sur l’île Kigigak, dans le delta Yukon-Kuskokwim, en Alaska, et sur l’île Ayopechan, dans le delta Chaun, au Tchoukotcha, où des protocoles d’étude similaires sur le terrain ont été adoptés. La méthode du maximum de vraisemblance Cormack-Jolly-Seber a servi à estimer la survie apparente (φ) et la probabilité de recapture (p) à partir de données de marquage et de relocalisation. Nous avons tenté de déterminer a) si les sous-populations de la Russie et de l’Alaska avaient des taux de survie différents, b) si les taux de survie variaient d’une année à l’autre et c) si le taux de survie affichait une tendance à la hausse ou à la baisse au fil des ans à l’un ou l’autre des sites. Nous n’avons trouvé aucune preuve justifiant le taux de survie différent aux deux aires de reproduction au moyen de la comparaison des moyennes de survie au fil des ans, et nous n’avons pas trouvé de preuve importante permettant de déceler une tendance linéaire au fil des ans en matière de survie à l’un ou l’autre des deux sites. De plus, nos données ont permis d’étayer des modèles ayant des taux de survie annuels variables à l’île Kigigak et des taux de survie constants à l’île Ayopechan. Des contraintes en matière de taille d’échantillons ont empêché de faire l’estimation des taux de survie annuels à l’île Ayopechan. Le fait que nous n’ayons pas trouvé de différence entre les moyennes de survie des deux sites soutient l’idée selon laquelle la survie peut être tributaire des conditions des aires d’hivernage.Данные об изменении выживаемости в географически обособленных гнездовых популяциях позволяют понять тенденции динамики популяций рассматриваемого вида. В период с 1950-х по 1990-е гг. наблюдалось резкое снижение численности гнездовой популяции очковой гаги в дельте рр. Юкон-Кускоквим, предположительно обусловленное низкой выживаемостью взрослых самок из-за сильного пресса хищников и отравления птиц свинцом в районах гнездования. Мы сравнивали показатели ежегодной выживаемости взрослых самок очковой гаги на о. Кигигак, дельта рр. Юкон-Кускоквим, Аляска, США и на о. Айопечан, дельта рр. Чаун-Пучевеем, Чукотка, Россия. Идентичные полевые протоколы были разработаны и применены в обоих районах исследования. Метод максимального правдоподобия Кормака-Джоли-Себера использовался для оценки ежегодной выживаемости (φ) и вероятности обнаружения (p) птиц по данным повторных отловов. Мы проверяли: а) существование статистически значимых различий в выживаемости самок очковой гаги чукотской и аляскинской популяций в период с 2002 по 2015 гг.; б) межгодовые колебания ежегодной выживаемости; в) наличие тенденций повышения или понижения выживаемости с течением времени в каждой из популяций. Мы не выявили статистически достоверных различий в выживаемости самок из двух районов гнездования, а так же не обнаружили тренда выживаемости со временем ни в одной из популяций. Данные, которыми мы располагаем, позволили оценить ежегодную выживаемость самок на о. Кигигак и, по причине недостатка данных, среднюю межгодовую выживаемость самок на о. Айопечан. Наши выводы о том, что выживаемость самок одинакова в обеих популяциях, позволяют предположить, что на выживаемость очковых гаг в меньшей степени влияют условия гнездовых территорий, чем комплексные условия акватории зимовки
Nor98 scrapie identified in the United States
A distinct strain of scrapie identified in sheep of Norway in 1998 has since been identified in numerous countries throughout Europe. The disease is known as Nor98 or Nor98-like scrapie, among other names. Distinctions between classic scrapie and Nor98 scrapie are made based on histopathology and immunodiagnostic results. There are also differences in the epidemiology, typical signalment, and likelihood of clinical signs being observed. In addition, sheep that have genotypes associated with resistance to classic scrapie are not spared from Nor98 disease. The various differences between classic and Nor98 scrapie have been consistently reported in the vast majority of cases described across Europe. The current study describes in detail the pathologic changes and diagnostic results of the first 6 cases of Nor98 scrapie disease diagnosed in sheep of the United States
UK National Ecosystem Assessment Follow-on. Work Package 6: Shared, plural and cultural values of ecosystems
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Lewy Body Dementia Association\u27s Research Centers of Excellence Program: Inaugural Meeting Proceedings.
The first Lewy Body Dementia Association (LBDA) Research Centers of Excellence (RCOE) Investigator\u27s meeting was held on December 14, 2017, in New Orleans. The program was established to increase patient access to clinical experts on Lewy body dementia (LBD), which includes dementia with Lewy bodies (DLB) and Parkinson\u27s disease dementia (PDD), and to create a clinical trials-ready network. Four working groups (WG) were created to pursue the LBDA RCOE aims: (1) increase access to high-quality clinical care, (2) increase access to support for people living with LBD and their caregivers, (3) increase knowledge of LBD among medical and allied (or other) professionals, and (4) create infrastructure for a clinical trials-ready network as well as resources to advance the study of new therapeutics
Shared, plural and cultural values of ecosystems:UK National Ecosystem Assessment Follow-on Work Package Report 6
Shared, plural and cultural values of ecosystems:UK National Ecosystem Assessment Follow-on Work Package Report 6
Presence and Persistence of Ebola or Marburg Virus in Patients and Survivors: A Rapid Systematic Review
Background: The 2013-15 Ebola outbreak was unprecedented due to sustainedtransmission within urban environments and thousands of survivors. In 2014 the World Health Organization stated that there was insufficient evidence to give definitive guidance about which body fluids are infectious and when they pose a risk to humans. We report a rapid systematic review of published evidence on the presence of filoviruses in body fluids of infected people and survivors. Methods: Scientific articles were screened for information about filovirus in human body fluids. The aim was to find primary data that suggested high likelihood of actively infectious filovirus in human body fluids (viral RNA). Eligible infections were from Marburg virus (MARV or RAVV) and Zaire, Sudan, Taï Forest and Bundibugyo species of Ebola. [1] Cause of infection had to be laboratory confirmed (in practice either tissue culture or RT-PCR tests), or evidenced by compatible clinical history with subsequent positivity for filovirus antibodies or inflammatory factors. Data were extracted and summarized narratively. Results: 6831 unique articles were found, and after screening, 33 studies were eligible. For most body fluid types there were insufficient patients to draw strong conclusions, and prevalence of positivity was highly variable. Body fluids taken >16 days after onset were usually negative. In the six studies that used both assay methods RT-PCR tests for filovirus RNA gave positive results about 4 times more often than tissue culture. Conclusions: Filovirus was reported in most types of body fluid, but not in every sample from every otherwise confirmed patient. Apart from semen, most non-blood, RT-PCR positive samples are likely to be culture negative and so possibly of low infectious risk. Nevertheless, it is not apparent how relatively infectious many body fluids are during or after illness, even when culture-positive, not least because most test results come from more severe cases. Contact with blood and blood-stained body fluids remains the major risk for disease transmission because of the known high viral loads in blood
Vulnerability pathways to mental health outcomes in children and parents during COVID-19
We examined pathways from pre-existing psychosocial and economic vulnerability to mental health difficulties and stress in families during the COVID-19 pandemic. Data from two time points from a multi-cohort study initiated during the COVID-19 pandemic were used. Parents of children 6–18 years completed questionnaires on pre-COVID-19 socioeconomic and demographic factors in addition to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning. Youth 10 years and older also completed their own measures of mental health and stress. Using structural equation modelling, pathways from pre-existing vulnerability to material deprivation and stress due to COVID-19 restrictions, mental health, and family functioning, including reciprocal pathways, were estimated. Pre-existing psychosocial and economic vulnerability predicted higher material deprivation due to COVID-19 restrictions which in turn was associated with parent and child stress due to restrictions and mental health difficulties. The reciprocal effects between increased child and parent stress and greater mental health difficulties at Time 1 and 2 were significant. Reciprocal effects between parent and child mental health were also significant. Finally, family functioning at Time 2 was negatively impacted by child and parent mental health and stress due to COVID-19 restrictions at Time 1. Psychosocial and economic vulnerability is a risk factor for material deprivation during COVID-19, increasing the risk of mental health difficulties and stress, and their reciprocal effects over time within families. Implications for prevention policy and parent and child mental health services are discussed
EON-ROSE and the Canadian Cordillera Array – Building Bridges to Span Earth System Science in Canada
EON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) is a new initiative for a pan-Canadian research collaboration to holistically examine Earth systems from the ionosphere into the core. The Canadian Cordillera Array (CC Array) is the pilot phase, and will extend across the Cordillera from the Beaufort Sea to the U.S. border. The vision for EON-ROSE is to install a network of telemetered observatories to monitor solid Earth, environmental and atmospheric processes. EON-ROSE is an inclusive, combined effort of Canadian universities, federal, provincial and territorial government agencies, industry, and international collaborators. Brainstorming sessions and several workshops have been held since May 2016. The first station will be installed at Kluane Lake Research Station in southwestern Yukon during the summer of 2018. The purpose of this report is to provide a framework for continued discussion and development.RÉSUMÉEON-ROSE (Earth-System Observing Network - Réseau d’Observation du Système terrestrE) est une nouvelle initiative de collaboration de recherche pancanadienne visant à étudier de manière holistique les systèmes terrestres, depuis l’ionosphère jusqu’au noyau. Le Réseau canadien de la cordillère (CC Array) en est la phase pilote, laquelle couvrira toute la Cordillère, de la mer de Beaufort jusqu’à la frontière étasunienne. L’objectif d’EON-ROSE est d’installer un réseau d’observatoires télémétriques pour suivre en continu les processusterrestres, environnementaux et atmosphériques. EON-ROSE est un effort combiné et inclusif des universités canadiennes, des organismes gouvernementaux fédéraux, provinciaux et territoriaux, de l’industrie et de collaborateurs internationaux. Des séances de remue-méninges et plusieurs ateliers ont été tenus depuis mai 2016. La première station sera installée à la station de recherche du lac Kluane, dans le sud-ouest du Yukon, au cours de l’été 2018. Le but du présent rapport est de fournir un cadre de discussion et de développement continu
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