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Selected AbstractsDIFFERENTIATION AMONG POPULATIONS WITH MIGRATION, MUTATION, AND DRIFT: IMPLICATIONS FOR GENETIC INFERENCEEVOLUTION, Issue 1 2006Seongho Song Abstract Populations may become differentiated from one another as a result of genetic drift. The amounts and patterns of differentiation at neutral loci are determined by local population sizes, migration rates among populations, and mutation rates. We provide exact analytical expressions for the mean, variance, and covariance of a stochastic model for hierarchically structured populations subject to migration, mutation, and drift. In addition to the expected correlation in allele frequencies among populations in the same geographic region, we demonstrate that there is a substantial correlation in allele frequencies among regions at the top level of the hierarchy. We propose a hierarchical Bayesian model for inference of Wright's F -statistics in a two-level hierarchy in which we estimate the among-region correlation in allele frequencies by substituting replication across loci for replication across time. We illustrate the approach through an analysis of human microsatellite data, and we show that approaches ignoring the among-region correlation in allele frequencies underestimate the amount of genetic differentiation among major geographic population groups by approximately 30%. Finally, we discuss the implications of these results for the use and interpretation of F -statistics in evolutionary studies. [source] An investigation into the composition, complexity and functioning of snake communities in the mangroves of south-eastern NigeriaAFRICAN JOURNAL OF ECOLOGY, Issue 3 2002Luca Luiselli Abstract The structure of the snake community was studied between 1996 and 2000 on a transect in the mangrove ecological zone of southern Nigeria, West Africa. In three major habitats, both taxonomical diversity and frequency of observations in relation to sampling effort were investigated. In general terms, the complexity of the snake community appeared less than in other habitats of the same geographic region (i.e. swamp forest and forest,plantation mosaics). In fact, only eighteen species were recorded, whereas 43 species are known to inhabit neighbouring habitats. A Principal Component Analysis allowed arrangement of the various species into two main groups in relation to the habitats of capture: (1) a group of species of rainforest biota (i.e. Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae), and (2) a group of species that, at least in Niger Delta, are typically linked to altered habitats, including derived savannas, plantations and suburbia (i.e. Psammophis cf. phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). The community structure in terms of food habits and body sizes appeared similar to those of other snake assemblages from different habitats of southern Nigeria. The conservation implications of our results are also discussed. Résumé On a étudié entre 1996 et 2000 la structure de la communauté des serpents dans un transect de la zone écologique de mangroves du sud du Nigeria, en Afrique de l'Ouest. On a étudié, dans trois habitats importants, la diversité taxonomique et la fréquence des observations par rapport à l'importance des échantillonnages. En termes généraux, la communauté des serpents y semblait moins complexe que dans d'autres habitats de la même région géographique (c.-à-d. la forêt marécageuse et une mosaïque de plantations forestières). En fait, on n'a rapporté que 18 espèces, alors qu'on sait que 43 espèces vivent dans les habitats voisins. Une Analyse du Composant Principal a permis de ranger les différentes espèces en deux groupes principaux, liés aux habitats où se sont faites les captures : (1) un groupe avec les espèces des biotes de forêt pluviale (Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae) et (2) un groupe d'espèces qui, au moins dans le delta du Niger, sont typiquement liées à des habitats dégradés, y compris des savanes dérivées, des plantations et des faubourgs urbains (Psammophis phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). La structure de la communauté, en ce qui concerne les habitudes alimentaires et la taille corporelle, était semblable à celle des autres groupes de serpents dans différents habitats du sud du Nigeria. On discute de l'implication de nos résultats pour la conservation. [source] The clinical nurse leader: a catalyst for improving quality and patient safetyJOURNAL OF NURSING MANAGEMENT, Issue 5 2008FAAN, JOAN M. STANLEY PhD Aim, The clinical nurse leader (CNL®) is a new nursing role introduced by the American Association of Colleges of Nursing (AACN). This paper describes its potential impact in practice. Background, Significant pressures are being placed on health care delivery systems to improve patient care outcomes and lower costs in an environment of diminishing resources. Method, A naturalistic approach is used to evaluate the impact the CNL has had on outcomes of care. Case studies describe the CNL implementation experiences at three different practice settings within the same geographic region. Results, Cost savings, including improvement on Centers for Medicare and Medicaid Services (CMS) core measures, are realized quickly in settings where the CNL role has been integrated into the care delivery model. Conclusions, With the growing calls for improved outcomes and more cost-effective care, the CNL role provides an opportunity for nursing to lead innovation by maximizing health care quality while minimizing costs. Implications for nursing management, Nursing is in a unique position to address problems that plague the nation's health system. The CNL represents an exciting and promising opportunity for nursing to take a leadership role, in collaboration with multiple practice partners, and implement quality improvement and patient safety initiatives across all health care settings. [source] Alcohol and Drug Use in Rural Colonias and Adjacent Urban Areas of the Texas BorderTHE JOURNAL OF RURAL HEALTH, Issue 2007Richard T. Spence PhD ABSTRACT:,Context: Little is known about substance use and treatment utilization in rural communities of the United States/Mexico border. Purpose: To compare substance use and need and desire for treatment in rural colonias and urban areas of the border. Methods: Interviews were conducted in 2002-2003 with a random sample of adults living in the lower Rio Grande Valley of Texas, adjacent to the Mexican border. The present analysis compares responses from 400 residents of rural colonias to those of 395 residents of cities and towns in the same geographic region. Findings: While the prevalence of drug use and drug-related problems was similar in both areas, binge drinking and alcohol dependence were higher in rural colonias than in urban areas and remained so after taking demographic and neighborhood variables into account. An increase in illicit drug use and substance-related problems in rural but not urban areas was seen when comparing results from this study with those of a previous survey conducted in 1996. The percentage of adults in potential need of treatment and the percentage motivated to seek it were similar in both urban and rural areas. However, colonia residents were more likely than their urban counterparts to be recent immigrants and to have lower incomes and educational attainment, factors that can increase the barriers they face in getting needed services. Conclusions: Rural areas are "catching up" with urban areas in problematic substance use. Given the potential barriers to accessing treatment services in rural areas, efforts should be focused on reaching those residents. [source] Implications of family environment and language development: comparing typically developing children to those with spina bifidaCHILD: CARE, HEALTH AND DEVELOPMENT, Issue 5 2009B. Vachha Abstract Introduction This study examines the effect of family environment on language performance in children with myelomeningocele compared with age- and education-matched controls selected from the same geographic region. Methods Seventy-five monolingual (English) speaking children with myelomeningocele [males: 30; ages: 7,16 years; mean age: 10 years 1 month, standard deviation (SD) 2 years 7 months] and 35 typically developing children (males: 16; ages 7,16 years; mean age: 10 years 9 months, SD 2 years 6 months) participated in the study. The Comprehensive Assessment of Spoken Language (CASL) and the Wechsler tests of intelligence were administered individually to all participants. The CASL measures four subsystems: lexical, syntactic, supralinguistic and pragmatic. Parents completed the Family Environment Scale (FES) questionnaire and provided background demographic information. Standard independent sample t -tests, chi-squared and Fisher's exact tests were used to make simple comparisons between groups for age, socio-economic status, gender and ethnicity. Spearman correlation coefficients were used to detect associations between language and FES data. Group differences for the language and FES scores were analysed with a multivariate analysis of variance at a P -value of 0.05. Results For the myelomeningocele group, both Spearman correlation and partial correlation analyses revealed statistically significant positive relationships for the FES ,intellectual,cultural orientation' (ICO) variable and language performance in all subsystems (P < 0.01). For controls, positive associations were seen between: (1) ICO and lexical/semantic and syntactic subsystems; and (2) FES ,independence' and lexical/semantic and supralinguistic tasks. Conclusions The relationship between language performance and family environment appears statistically and intuitively sound. As in our previous study, the positive link between family focus on intellectually and culturally enhancing activities and language performance among children with myelomeningocele and shunted hydrocephalus remains robust. Knowledge of this relationship should assist parents and professionals in supporting language development through activities within the natural learning environment. [source] Ficolin 2 (FCN2) functional polymorphisms and the risk of rheumatic fever and rheumatic heart diseaseCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2009I. J. Messias-Reason Summary Ficolins are pattern-recognition proteins involved in innate immunity, which upon binding to their specific pathogen-associated molecular patterns on the microbial surfaces trigger the immune response either by binding to collectin cellular receptors or by initiating the complement lectin pathway. In humans, three ficolin genes have been identified, which encode ficolin-1 (M-ficolin), ficolin-2 (L-ficolin) and ficolin-3 (H-ficolin or Hakata antigen). Ficolin-2 was shown to bind to lipoteichoic acid, a cell wall constituent in all Gram-positive bacteria such as Streptococcus pyogenes, which is the aetiological agent of rheumatic fever (RF) and its most severe sequelae, chronic rheumatic heart disease (CRHD). Here we investigated polymorphisms in the promoter region of the FCN2 gene (at positions ,986/,602 and +4) in 122 patients with RF and CRHD and in 210 healthy subjects from the same geographic region and socioeconomic background. The haplotype ,986/,602/,4 G/G/A, which is related to low levels of L-ficolin, was observed more frequently in the CRHD group when compared to the healthy subjects [99/162, 61·1% versus 211/420, 50·2%, odds ratio (OR) 1·6, confidence interval (CI) 95% 1·1,2·3, P = 0·021]. The haplotype ,986/,602/,4 A/G/A was observed more frequently in the healthy group when compared to the affected (RF plus CRHD) subjects (31/420, 7·4% versus 6/244, 2·5%, OR 3·2, CI 95% 0·13,0·77, P = 0·008). Based on those findings, one can conclude that polymorphisms associated with low levels of L-ficolin level may predispose an individual to recurrent and/or more severe streptococcal infection. [source] | |||||||||||||