RESUMEN
Access to high-quality food is critical for long-distance migrants to provide energy for migration and arrival at breeding grounds in good condition. We studied effects of changing abundance and availability of a marine food, common eelgrass (Zostera marina L.), on an arctic-breeding, migratory goose, black brant (Brant bernicla nigricans Lawrence 1846), at a key non-breeding site, Bahía San Quintín, Mexico. Eelgrass, the primary food of brant, is consumed when exposed by the tide or within reach from the water's surface. Using an individual-based model, we predicted effects of observed changes (1991-2013) in parameters influencing food abundance and availability: eelgrass biomass (abundance), eelgrass shoot length (availability, as longer shoots more within reach), brant population size (availability, as competition greater with more birds), and sea level (availability, as less food within reach when sea level higher). The model predicted that the ability to gain enough energy to migrate was most strongly influenced by eelgrass biomass (threshold January biomass for migration = 60 g m-2 dry mass). Conversely, annual variation in population size (except for 1998), was relatively low, and variation in eelgrass shoot length and sea level were not strongly related to ability to migrate. We used observed data on brant body mass at Bahía San Quintín and annual survival to test for effects of eelgrass biomass in the real system. The lowest observed values of body mass and survival were in years when biomass was below 60 g m-2, although in some years of low biomass body mass and/or survival was higher. This suggests that the real birds may have some capacity to compensate to meet their energy demands when eelgrass biomass is low. We discuss consequences for brant population trends and conservation.
RESUMEN
1. Patterns of temporary emigration (associated with non-breeding) are important components of variation in individual quality. Permanent emigration from the natal area has important implications for both individual fitness and local population dynamics. 2. We estimated both permanent and temporary emigration of black brent geese (Branta bernicla nigricans Lawrence) from the Tutakoke River colony, using observations of marked brent geese on breeding and wintering areas, and recoveries of ringed individuals by hunters. We used the likelihood developed by Lindberg, Kendall, Hines & Anderson 2001 (Combining band recovery data and Pollock's robust design to model temporary and permanent emigration. Biometrics, 57, 273-281) to assess hypotheses and estimate parameters. 3. Temporary emigration (the converse of breeding) varied among age classes up to age 5, and differed between individuals that bred in the previous years vs. those that did not. Consistent with the hypothesis of variation in individual quality, individuals with a higher probability of breeding in one year also had a higher probability of breeding the next year. 4. Natal fidelity of females ranged from 0.70 +/- 0.07-0.96 +/- 0.18 and averaged 0.83. In contrast to Lindberg et al. (1998), we did not detect a relationship between fidelity and local population density. Natal fidelity was negatively correlated with first-year survival, suggesting that competition among individuals of the same age for breeding territories influenced dispersal. Once females nested at the Tutakoke River, colony breeding fidelity was 1.0. 5. Our analyses show substantial variation in individual quality associated with fitness, which other analyses suggest is strongly influenced by early environment. Our analyses also suggest substantial interchange among breeding colonies of brent geese, as first shown by Lindberg et al. (1998).
Asunto(s)
Migración Animal/fisiología , Gansos/fisiología , Preferencia en el Apareamiento Animal/fisiología , Reproducción/fisiología , Conducta Sexual Animal/fisiología , Factores de Edad , Animales , Cruzamiento , Ecosistema , Femenino , Masculino , Densidad de Población , Dinámica Poblacional , Análisis de SupervivenciaRESUMEN
Dentists have needed an objective way in which to evaluate a smile. A method for determining the ideal size and position of the anterior teeth has been presented here. Use of the FIVE to evaluate the RED proportion and the width-to-height ratio, tempered with sound clinical judgment, gives pleasing and consistent results. With the diversity that exists in nature, rarely does the final result follow all the mathematical rules of proportional smile design. This approach may serve as a foundation on which to base initial smile design, however. When one begins to understand the relationship between beauty, mathematics, and the surrounding world, one begins to appreciate their interdependence.
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Estética Dental , Cara/anatomía & histología , Sonrisa , Diente/anatomía & histología , Adulto , Cefalometría , Alargamiento de Corona , Diente Canino/anatomía & histología , Restauración Dental Permanente/métodos , Diseño de Dentadura , Dentadura Parcial Fija , Femenino , Humanos , Procesamiento de Imagen Asistido por Computador , Incisivo/anatomía & histología , Odontometría , Fotografía DentalRESUMEN
PURPOSE: This study aimed to determine dentists' esthetic preferences of the maxillary anterior teeth as influenced by different proportions. The goal was to link choices to demographic data as to the experience, gender, and training of the dentist. METHOD AND MATERIALS: Computer-manipulated images of the 6 maxillary anterior teeth were generated from a single image and assigned to 5 tooth-height groups (very short, short, normal height, tall, and very tall). For each group, 4 images were generated by manipulating the relative proportion of the central incisors, lateral incisors, and canines according to the proportions 62% (or "golden proportion"), 70%, 80%, and "normal" or not further altered. The images were randomly ordered on a web page that contained a form asking for demographic data and fields asking for a ranking of the images. Dentists were asked via e-mail to visit the web page and complete the survey. The responses were tabulated and analyzed with repeated measures logistic regression with the alpha at 0.05. A subset of North American respondents was chosen for further analysis. RESULTS: A total of 549 valid responses were received and analyzed from dentists in 38 countries. There were statistically significant differences in all groups for the variables of proportion, group (tooth height), and their interaction. The 80% proportion was judged best for the Very Short and Short groups. Three of the choices were almost equally picked for the Normal Height and Tall groups, and the golden proportion was judged best for the Very Tall group. The variables of year of graduation, gender, professional activity, generalist or specialist, or number of patients were not significantly correlated with the choices for the North American respondents. CONCLUSIONS: Dentists preferred the 80 percent proportion when viewing short or very short teeth and the golden proportion when viewing very tall teeth. Golden proportion was worst for normal height or shorter teeth and the 80% proportion for tall or very tall teeth. They picked no clear-cut best for normal height or tall teeth, and their choices could not be predicted based on gender, specialist training, experience, or patient load.
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Actitud del Personal de Salud , Diente Canino/anatomía & histología , Odontólogos , Estética Dental , Incisivo/anatomía & histología , Internet , Redes de Comunicación de Computadores , Demografía , Educación en Odontología , Femenino , Odontología General , Humanos , Procesamiento de Imagen Asistido por Computador , Modelos Logísticos , Masculino , Maxilar , Práctica Profesional , Factores Sexuales , Especialidades OdontológicasRESUMEN
Measuring health risk assessment and counseling recommendations can be challenging. In this study, unannounced standardized patients (lay individuals trained to replicate a clinical encounter consistently) were used to evaluate HIV preventive performance of 22 family nurse practitioners (NPs) and family physicians. Standardized patients were trained to present an identical scenario of a heterosexual individual at risk for HIV exposure. Audiotaping via a hidden microphone and recorder was used to validate the reproducibility of clinical encounters and accuracy of standardized patient assessment. Standardized patients were highly accurate in both case portrayal and assessment activities with an indexed Kappa coefficient of 0.82. Determining risk, including condom use, sexual orientation, and number of past sexual partners, was performed less often than experts advise by both physicians and NPs (done between 9% and 63% of encounters). Providing patient education to reduce risk, including educating about abstinence, mutual monogamy, and limiting sexual partners, was also done in only 9% to 36% of encounters. The methodology used was innovative. There is room for improvement in the provider participants' clinical performance of HIV risk assessment, patient education, and counseling. However, the results of this case study cannot be generalized.
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Medicina Familiar y Comunitaria/normas , Infecciones por VIH/prevención & control , Enfermeras Practicantes/normas , Pautas de la Práctica en Medicina/normas , Medición de Riesgo , Humanos , Educación del Paciente como AsuntoRESUMEN
This paper describes the use of focus groups as a data-gathering tool, in both theoretical and practical terms. Calder's discussion of focus groups is presented as the basis of the theory, and the marketing study conducted by the Midcontinental Region of the National Network of Libraries of Medicine serves as the backdrop to highlight some of the practical aspects of using this qualitative data-gathering method. Results of the marketing study are presented to illustrate the types of data that can be gathered using this methodology and the types of plans for future activities that can be developed based on the data gathered.
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Grupos Focales , Personal de Salud , Bibliotecas Médicas , Servicios de Biblioteca , Comunicación , Recolección de Datos , Humanos , Servicios de Información , Teoría de la Información , Bibliotecólogos , National Library of Medicine (U.S.) , Estados UnidosRESUMEN
Long-term care in the unique US welfare state is largely a private responsibility, and current long-term care policy rests on the assumption that care--of the elderly, in our example--will be provided by women. Because alternatives to personal care of dependent kin are available based on ability to pay, lower-income women bear a disproportionate burden. A study was undertaken to examine the experience of caregiving in a convenience sample of 10 low-income women providing informal care to a frail elder. Half the study sample were women of color. Responses to the core question, "What is taking care of ... like for you?" were analyzed using phenomenologic analysis techniques. A pattern of four interrelated key themes, which describe a transitional process beginning with inevitability of the caregiving role and ending with acquiescence to it, were identified. These data are placed in the political context that surrounds caregiving; such analyses are important both to generate theory and to identify possible points of intervention.