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1.
PLoS One ; 16(7): e0254686, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34270622

RESUMO

Knowledge of non-breeding distributions is a crucial component to seabird conservation, as conditions during the non-breeding period can play an important role in regulating seabird populations. Specifically, if seabirds from different colonies share the same wintering grounds, conditions in that shared region could have a widespread impact on multiple breeding populations. Red-legged kittiwakes (Rissa brevirostris) are endemic to the Bering Sea and may be especially susceptible to effects of climate change due to a restricted breeding range, small population size, and specialized diet. To examine whether red-legged kittiwakes from different breeding colonies overlapped in winter distribution and activity patterns, we used geolocation loggers to simultaneously track individuals from the two largest red-legged kittiwake breeding colonies in Alaska (separated by over 1000 km) during two consecutive non-breeding periods. We found that non-breeding activity patterns were generally similar between birds originating from the two colonies, but birds employed different migratory strategies during the early winter. Kittiwakes from Buldir Island in the western Aleutian Islands left the colony in September and immediately headed west, spending October through December around the Sea of Okhotsk and the Kuril Islands. In contrast, birds from St. George Island in the Pribilof Islands remained in the eastern Bering Sea or around the eastern Aleutian Islands for a couple months before traveling farther west. During late winter however, from January through March, birds from both colonies converged south of Kamchatka and east of the Kuril Islands over the Kuril-Kamchatka Trench and in the Western Subarctic Gyre before returning to their respective colonies in the spring. This late winter overlap in distributions along the Kuril-Kamchatka Trench suggests the region is a winter hotspot for red-legged kittiwakes and highlights the importance of this region for the global kittiwake population.


Assuntos
Migração Animal , Charadriiformes/fisiologia , Conservação dos Recursos Naturais/estatística & dados numéricos , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Alaska , Animais , Geografia , Estações do Ano
2.
Ecol Evol ; 9(10): 6157-6164, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31161027

RESUMO

Aerial distance sampling of bears to estimate population size has been used throughout many parts of Alaska. The distance sampling models are complex since they need to account for undetected bears and differences in detection probabilities. This will require covariates and mark-recapture data. The models proposed by Schmidt et al. do not use covariates or mark-recapture data and are inappropriate for these surveys.

3.
Biometrics ; 64(3): 968-976, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18047525

RESUMO

We propose a general framework for the analysis of animal telemetry data through the use of weighted distributions. It is shown that several interpretations of resource selection functions arise when constructed from the ratio of a use and availability distribution. Through the proposed general framework, several popular resource selection models are shown to be special cases of the general model by making assumptions about animal movement and behavior. The weighted distribution framework is shown to be easily extended to readily account for telemetry data that are highly autocorrelated; as is typical with use of new technology such as global positioning systems animal relocations. An analysis of simulated data using several models constructed within the proposed framework is also presented to illustrate the possible gains from the flexible modeling framework. The proposed model is applied to a brown bear data set from southeast Alaska.


Assuntos
Comportamento Animal , Biometria/métodos , Atividade Motora , Telemetria/estatística & dados numéricos , Animais , Interpretação Estatística de Dados , Ecossistema , Sistemas de Informação Geográfica , Masculino , Modelos Biológicos , Modelos Estatísticos , Ursidae/fisiologia , Ursidae/psicologia
4.
PLoS One ; 10(8): e0136403, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26317984

RESUMO

Distance sampling is a widely used method to estimate animal population size. Most distance sampling models utilize a monotonically decreasing detection function such as a half-normal. Recent advances in distance sampling modeling allow for the incorporation of covariates into the distance model, and the elimination of the assumption of perfect detection at some fixed distance (usually the transect line) with the use of double-observer models. The assumption of full observer independence in the double-observer model is problematic, but can be addressed by using the point independence assumption which assumes there is one distance, the apex of the detection function, where the 2 observers are assumed independent. Aerially collected distance sampling data can have a unimodal shape and have been successfully modeled with a gamma detection function. Covariates in gamma detection models cause the apex of detection to shift depending upon covariate levels, making this model incompatible with the point independence assumption when using double-observer data. This paper reports a unimodal detection model based on a two-piece normal distribution that allows covariates, has only one apex, and is consistent with the point independence assumption when double-observer data are utilized. An aerial line-transect survey of black bears in Alaska illustrate how this method can be applied.


Assuntos
Modelos Teóricos
5.
J Music Ther ; 40(2): 78-112, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14505444

RESUMO

The purposes of this study were (a) to develop a test of complex song appraisal that would be suitable for use with adults who use a cochlear implant (assistive hearing device) and (b) to compare the appraisal ratings (liking) of complex songs by adults who use cochlear implants (n = 66) with a comparison group of adults with normal hearing (n = 36). The article describes the development of a computerized test for appraisal, with emphasis on its theoretical basis and the process for item selection of naturalistic stimuli. The appraisal test was administered to the 2 groups to determine the effects of prior song familiarity and subjective complexity on complex song appraisal. Comparison of the 2 groups indicates that the implant users rate 2 of 3 musical genres (country western, pop) as significantly more complex than do normal hearing adults, and give significantly less positive ratings to classical music than do normal hearing adults. Appraisal responses of implant recipients were examined in relation to hearing history, age, performance on speech perception and cognitive tests, and musical background.


Assuntos
Implantes Cocleares , Cognição , Surdez/reabilitação , Música , Percepção da Altura Sonora , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Percepção da Fala , Inquéritos e Questionários , Fatores de Tempo
6.
PLoS One ; 9(1): e85339, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24416394

RESUMO

Steller sea lion (Eumetopias jubatus) populations have undergone precipitous declines through their western Alaskan range over the last four decades with the leading hypothesis to explain this decline centering around changing prey quality, quantity, or availability for this species (i.e., nutritional stress hypothesis). Under chronic conditions of reduced food intake sea lions would conserve energy by limiting energy expenditures through lowering of metabolic rate known as metabolic depression. To examine the potential for nutritional stress, resting metabolic rate (RMR) and body composition were measured in free-ranging juvenile Steller sea lions (N = 91) at three distinct geographical locations (Southeast Alaska, Prince William Sound, Central Aleutian Islands) using open-flow respirometry and deuterium isotope dilution, respectively. Average sea lion RMR ranged from 6.7 to 36.2 MJ d(-1) and was influenced by body mass, total body lipid, and to a lesser extent, ambient air temperature and age. Sea lion pups captured in the Aleutian Islands (region of decline) had significantly greater body mass and total body lipid stores when compared to pups from Prince William Sound (region of decline) and Southeast Alaska (stable region). Along with evidence of robust body condition in Aleutian Island pups, no definitive differences were detected in RMR between sea lions sampled between eastern and western populations that could not be accounted for by higher percent total body lipid content, suggesting that that at the time of this study, Steller sea lions were not experiencing metabolic depression in the locations studied.


Assuntos
Metabolismo Basal , Composição Corporal/fisiologia , Leões-Marinhos/metabolismo , Fatores Etários , Alaska , Animais , Medição da Troca de Deutério , Feminino , Metabolismo dos Lipídeos , Masculino , Dinâmica Populacional
7.
8.
Ann Allergy Asthma Immunol ; 92(3): 335-9, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15049397

RESUMO

BACKGROUND: Accuracy and reliability of diary data collected in allergic rhinitis trials depends on how and when the information is recorded by the subjects. OBJECTIVE: To compare diary data collected by using paper (optical mark readable) and electronic [telephone, interactive voice response system (IVRS)] tools. METHODS: There was a randomized, 3-week, 3-way, crossover trial, in 87 adults with allergic rhinitis recording diary data at home. Outcome measures were (1) comparison of symptom data during weeks when both or only 1 instrument was used; (2) missing data: and (3) ease of use and participant preference. RESULTS: More than 40,000 symptom data elements were recorded by 72 protocol-correct subjects. Symptoms recorded during the week that both instruments were used and when the 2 instruments were used alone were indistinguishable. Overall, 0.45% of paper and 4.12% of IVRS symptom data were missing. Of 10,080 paired data collected on paper and IVRS diaries during the week in which subjects used both, 94.44% were identical. Using IVRS, 63.2% of protocol-correct data were entered within the designated time and 87.6% within 1 half-day of the time specified; 85% of subjects preferred the paper instrument, 4% preferred IVRS, and 11% had no preference. CONCLUSIONS: A paper-based instrument can capture data indistinguishable from data captured from an electronic product. Processes to collect diary data should be evaluated for each study rather than simply to use the "latest" technology. Another interpretation is that frequency of recording diary data does not have a significant impact on outcomes.


Assuntos
Coleta de Dados/métodos , Avaliação de Resultados em Cuidados de Saúde , Adulto , Estudos Cross-Over , Coleta de Dados/instrumentação , Processamento Eletrônico de Dados , Eletrônica , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Rinite Alérgica Sazonal/fisiopatologia , Sensibilidade e Especificidade
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