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Effective Population (effective + population)

Distribution by Scientific Domains
Life Sciences50%

Terms modified by Effective Population

  • effective population size
    		•

    Selected Abstracts

    Prevention of fetal alcohol spectrum disorders,

    DEVELOPMENTAL DISABILITIES RESEARCH REVIEW, Issue 3 2009
    R. Louise Floyd
    Abstract Alcohol use among women of childbearing age is a leading, preventable cause of birth defects and developmental disabilities in the United States. Although most women reduce their alcohol use upon pregnancy recognition, some women report drinking during pregnancy and others may continue to drink prior to realizing they are pregnant. These findings emphasize the need for effective prevention strategies for both pregnant and nonpregnant women who might be at risk for an alcohol-exposed pregnancy (AEP). This report reviews evidence supporting alcohol screening and brief intervention as an effective approach to reducing problem drinking and AEPs that can lead to fetal alcohol spectrum disorders. In addition, this article highlights a recent report of the National Task Force on Fetal Alcohol Syndrome and Fetal Alcohol Effect that describes effective interventions to reduce alcohol use and AEPs, and outlines recommendations on promoting and improving these strategies. Utilizing evidence-based alcohol screening tools and brief counseling for women at risk for an AEP and other effective population-based strategies can help achieve future alcohol-free pregnancies. © 2009 Wiley-Liss, Inc. Dev Disabil Res Rev 2009;15:193,199. [source]

    MATHEMATICAL CONSEQUENCES OF THE GENEALOGICAL SPECIES CONCEPT

    EVOLUTION, Issue 8 2002
    Richard R. Hudson
    Abstract A genealogical species is defined as a basal group of organisms whose members are all more closely related to each other than they are to any organisms outside the group ("exclusivity'), and which contains no exclusive group within it. In practice, a pair of species is so defined when phylogenies of alleles from a sample of loci shows them to be reciprocally monophyletic at all or some specified fraction of the loci. We investigate the length of time it takes to attain this status when an ancestral population divides into two descendant populations of equal size with no gene exchange, and when genetic drift and mutation are the only evolutionary forces operating. The number of loci used has a substantial effect on the probability of observing reciprocal monophyly at different times after population separation, with very long times needed to observe complete reciprocal monophyly for a large number of loci. In contrast, the number of alleles sampled per locus has a relatively small effect on the probability of reciprocal monophyly. Because a single mitochondrial or chloroplast locus becomes reciprocally monophyletic much faster than does a single nuclear locus, it is not advisable to use mitochondrial and chloroplast DNA to recognize genealogical species for long periods after population divergence. Using a weaker criterion of assigning genealogical species status when more than 50% of sampled nuclear loci show reciprocal monophyly, genealogical species status depends much less on the number of sampled loci, and is attained at roughly 4,7 N generations after populations are isolated, where N is the historically effective population size of each descendant. If genealogical species status is defined as more than 95% of sampled nuclear loci showing reciprocal monophyly, this status is attained after roughly 9,12 N generations. [source]

    Nest-site selection by Common Black-Hawks in southwestern New Mexico

    JOURNAL OF FIELD ORNITHOLOGY, Issue 1 2008
    Giancarlo Sadoti
    ABSTRACT Despite the interest of resource managers and conservationists in the status of Common Black-Hawk (Buteogallus anthracinus) populations in the southwestern United States, little is known about their nesting success and habitat requirements. Because such information is essential for effective population and habitat management, I examined the nesting success and nest-site selection of Common Black-Hawks in southwestern New Mexico during 2000 and 2001. Of the 37 nesting attempts in 21 territories, ,1 young fledged from 25 nests (68%). Comparison of nest-sites and nonused sites suggested that breeding Common Black-Hawks selected nest-sites in areas with a sparser and shorter subcanopy tree layer and in trees with a smaller trunk diameter and a greater minimum crown diameter. These differences appear to be related to variation in forest ages within territories, with nonused sites having fewer, but older, canopy trees than nest-sites. Sites with younger, smaller subcanopy trees may provide forest structure for more effective foraging, whereas the characteristics of younger nest tree canopies may reduce the risk of nest predation or offer more protection from inclement weather. Due to the limited range of this species in the southwestern United States, efforts to encourage the establishment and maturation of riparian forests in Common Black-Hawk breeding areas could be important in sustaining available nesting habitat and, in turn, maintaining or expanding current population levels. SINOPSIS Aunque existe interés de parte de profesionales en manejo de recursos y conservacionistas en el estatus de las poblaciones de Buteogallus anthracinus en el sudoeste de los Estados Unidos, poco se conoce sobre su éxito de anidamiento y requerimientos de hábitat. Por la razón que esta información es esencial para el éxito del manejo poblacional y del hábitat para esta especie, examiné el éxito de anidamiento y la selección del lugar de anidamiento de Buteogallus anthracinus en el sudeste del estado de Nueva México durante el 2000 y el 2001. De los 37 intentos de anidamiento en 21 territorios, ,1 de los polluelos volaron de 25 nidos (68%). Una comparación entre lugares donde se ubicaban los nidos y sitios no utilizados para anidar indica que individuos seleccionaron lugares para anidar en áreas con una menor cobertura y una menor altura del sub-dosel. Adicionalmente, los nidos fueron ubicados en árboles con un menor diámetro del tronco y con un mayor diámetro mínimo de la corona. Estas diferencias parecen ser relacionadas a la variación en la edad del bosque dentro de los territorios, con sitios no utilizados caracterizados por un número menor de árboles del dosel pero las cuales tienen una edad mayor que los árboles del dosel en los sitios donde se ubicaron los nidos. Sitios con árboles en el sub-dosel de menor edad y de menor tamaño podrían proveer la estructura del bosque necesaria para un forrajeo mas efectivo, mientras que las características de las coronas de los árboles de menor edad en la cual se encuentra el nido podrían reducir el riesgo de la depredación del nido o proveer mas protección de mal tiempo. Dado el rango limitado de esta especie en el sudeste de los Estados Unidos, los esfuerzos para animar el establecimiento y la maduración de los bosques riparios en las áreas de anidamiento de esta especie podrían ser importantes para mantener el hábitat disponible para anidar y a la vez mantener o expandir los tamaños actuales de las poblaciones. [source]

    Binge Drinking and Suboptimal Self-Rated Health Among Adult Drinkers

    ALCOHOLISM, Issue 8 2010
    James Tsai
    Background:, Binge drinking accounts for more than half of the 79,000 annual deaths in the United States that are owing to excessive drinking. The overall objective of our study was to examine the prevalence of binge drinking and consumption levels associated with suboptimal self-rated health among the general population of adult drinkers in all 50 states and territories in the United States. Methods:, The study included a total of 200,587 current drinkers who participated in the 2008 Behavioral Risk Factor Surveillance System (BRFSS) survey. We estimated the prevalence of binge drinking (i.e., ,5 drinks on 1 occasion for men or ,4 drinks on 1 occasion for women) and heavy drinking (i.e., an average of >14 drinks per week for men or >7 drinks per week for women), as well as the average number of binge episodes per person during a 30-day period. Odds ratios were produced with multivariate logistic regression models using binge-drinking levels as a predictor; status of suboptimal self-rated health was used as an outcome variable while controlling for sociodemographic, health, and behavioral risk factors. Results:, We estimate that 34.7 million adult drinkers in the United States engaged in binge drinking in 2008, including an estimated 42.2% who reported either heavy drinking or at least 4 binge-drinking episodes in a 30-day period. Binge drinking with such levels was associated with a 13,23% increased likelihood of reporting suboptimal self-rated health, when compared to the nonbinge drinkers. Conclusions:, Binge drinking continues to be a serious public health concern. Frequent binge drinkers or binge drinkers who consume alcohol heavily are especially at risk of suboptimal self-rated health. Our findings underscore the importance of broad-based implementation in health care settings of screening for and brief interventions to address alcohol misuse, as well as the continuing need to implement effective population-based prevention strategies to reduce alcohol-related morbidity and mortality. [source]