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Population Composition (population + composition)
Selected AbstractsCorrelation between population dynamics of mosquito larvae and their habitat qualitiesENTOMOLOGICAL RESEARCH, Issue 4 2008Lalit Mohan RANJEETA Abstract Surveillance of anopheline and culicine larvae was conducted fortnightly to determine population composition and density at seven sites in the area of the Mathura Refinery, Mathura, India during 2005,2006. The correlation between population of the vectors and their habitat quality was established. Temperature (0.978 and 0.85°C), pH (0.99 and 0.95), conductivity (0.98 and 0.98 mho) and calcium ion hardness (0.978 and 0.85 p.p.m.) were positively correlated with the populations of both larval species. In contrast, the correlation coefficients between the parameters total hardness, magnesium ion hardness, biochemical oxygen demand and chemical oxygen demand varied with the larval species. The anopheline larval population was dominant over the culicine population in the surveillance area. The distribution of anopheline mosquito larvae during the study period was found to be constant, and the average density of anopheline and culicine larvae was 84.70 and 15.30%, respectively, across all seven sites. Thus, the study demonstrated spatial and temporal population differences of mosquito larvae with respect to environmental factors, including water quality. [source] Metabolic profiling as a tool for revealing Saccharomyces interactions during wine fermentationFEMS YEAST RESEARCH, Issue 1 2006Kate S. Howell Abstract The multi-yeast strain composition of wine fermentations has been well established. However, the effect of multiple strains of Saccharomyces spp. on wine flavour is unknown. Here, we demonstrate that multiple strains of Saccharomyces grown together in grape juice can affect the profile of aroma compounds that accumulate during fermentation. A metabolic footprint of each yeast in monoculture, mixed cultures or blended wines was derived by gas chromatography , mass spectrometry measurement of volatiles accumulated during fermentation. The resultant ion spectrograms were transformed and compared by principal-component analysis. The principal-component analysis showed that the profiles of compounds present in wines made by mixed-culture fermentation were different from those where yeasts were grown in monoculture fermentation, and these differences could not be produced by blending wines. Blending of monoculture wines to mimic the population composition of mixed-culture wines showed that yeast metabolic interactions could account for these differences. Additionally, the yeast strain contribution of volatiles to a mixed fermentation cannot be predicted by the population of that yeast. This study provides a novel way to measure the population status of wine fermentations by metabolic footprinting. [source] Climate warming and the evolution of morphotypes in a reptileGLOBAL CHANGE BIOLOGY, Issue 2 2009VIRGINIE LEPETZ Abstract Climate warming is known to have effects on population dynamics through variations in survival, fecundity and density. However, the impacts of climate change on population composition are still poorly documented. Morphotypes are powerful markers to track changes in population composition. In the common lizard, Lacerta vivipara, individuals display two types of dorsal patterns: reticulated (R individuals) and linear (L individuals). We examined how local warming affected intrapopulation frequencies of these morphotypes across 11 years. We observed changes in morph frequency of dorsal patterns across years, paralleling the rise of spring temperatures. The proportion of R individuals increased with June temperatures in juveniles, yearlings, and adult males and females. Three mechanisms could explain these changes: phenotypic plasticity, microevolution and/or dispersal between populations. We investigated the ontogenetic determinism, fitness and recruitment rates associated with dorsal morphotypes. Dorsal pattern ontogeny showed temperature dependence but this relationship was not associated with the warming trend during this study. We found variation by morphotype in survival and clutch size, but these factors did not explain R frequency increases. Among all the parameters considered in this study, only a decrease of immigration, which was more pronounced in the L morphotype, could explain the change in population composition. To our knowledge, this provides the first evidence of the impact of climate warming on population composition due to its effects on immigration. [source] Multiscale multiresolution genetic algorithm with a golden sectioned population compositionINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2008Dae Seung Kim Abstract A new genetic algorithm (GA) strategy called the multiscale multiresolution GA is proposed for expediting solution convergence by orders of magnitude. The motivation for this development was to apply GAs to a certain class of large optimization problems, which are otherwise nearly impossible to solve. For the algorithm, standard binary design variables are binary wavelet transformed to multiscale design variables. By working with the multiscale variables, evolution can proceed in multiresolution; converged solutions at a low resolution are reused as a part of individuals of the initial population for the next resolution evolution. It is shown that the best solution convergence can be achieved if three initial population groups having different fitness levels are mixed at the golden section ratio. An analogy between cell division and the proposed multiscale multiresolution strategy is made. The specific applications of the developed method are made in topology optimization problems. Copyright © 2007 John Wiley & Sons, Ltd. [source] The Rise and Fall of Chinese Immigration to Canada: Newcomers from Hong Kong Special Administrative Region of China1 and Mainland China, 1980,20002INTERNATIONAL MIGRATION, Issue 3 2005Peter S. Li ABSTRACT An emerging perspective in the study of global diasporas stresses the effect of economic globalization and migration shifts in reshaping the population and identifying the formation of diaspora communities. This paper analyses the immigration patterns from Hong Kong and mainland China to Canada between the 1980s and 1990s, and shows that the migration shifts have been influenced by political and economic forces in Hong Kong and China, as well as changes in Canada's immigration policy. The imminent return of Hong Kong to China in 1997 and its uncertain political future in the 1990s were often cited as the main reasons for Hong Kong's large emigration in the late 1980s and early 1990s. In reality, the rising volume of Hong Kong emigration was prompted by the 1989 Tiananmen Square incident in China and its aftermath, and by the booming economy of Hong Kong in the early 1990s that created the means for many middle-class Chinese to emigrate. At the same time, Canada's expansion of the Business Immigration Program in the mid-1980s also benefited immigrant entrepreneurs from Hong Kong. In contrast, the Asian Financial Crisis of 1997 did not deter the economic growth of China. Immigration from China rose after 1989 when Canada allowed Chinese students studying in Canada to immigrate, but it was after the mid-1990s that immigration from China expanded due to Canada's greater emphasis on admitting economic immigrants and to China's growing middle class. The continuous arrival of well-educated and urban-based immigrants from China is likely to change the population composition and identity complexity of the Chinese community in Canada. LES HAUTS ET LES BAS DE L'IMMIGRATION CHINOISE AU CANADA : LES NOUVEAUX VENUS ORIGINAIRES DE LA RÉGION ADMINISTRATIVE SPÉCIALE DE HONG KONG1 ET DE LA CHINE CONTINENTALE, 1980,2000 Une perspective émergente dans l'étude des diasporas mondiales souligne l'effet de la mondialisation économique et des glissements migratoires dans le remodelage des populations et l'identification de la formation des communautés issues des diasporas. Cet ouvrage analyse les comportements migratoires en provenance de Hong Kong et de la Chine continentale en direction du Canada entre les années 80 et 90, et montre que les glissements migratoires ont été influencés par des forces politiques et économiques à l',uvre à Hong Kong et en Chine, ainsi que par des changements intervenus au niveau de la politique canadienne d'immigration. Le retour imminent de Hong Kong à la Chine en 1997 et son avenir politique incertain dans les années 90 ont souvent été cités comme les principales raisons pour l'importante émigration qui s'est produite au départ de Hong Kong à la fin des années 80 et au début des années 90. En réalité, l'ampleur croissante de l'émigration en provenance de Hong Kong a été suscitée par les événements de la place Tiananmen qui ont eu lieu en 1989 et par leurs retombées, ainsi que par l'essor économique de Hong Kong au début des années 90, ayant procuréà bon nombre de Chinois de la classe moyenne les moyens d'émigrer. Parallèlement, l'expansion du programme d'immigration commerciale mis en place par le Canada au milieu des années 80 a également profité aux entrepreneurs immigrants de Hong Kong. Par comparaison, la crise financière asiatique de 1997 n'a pas produit d'effet dissuasif sur la croissance économique de la Chine. L'immigration en provenance de Chine continentale a augmenté après 1989, lorsque le Canada a autorisé les étudiants chinois se trouvant sur son sol à immigrer légalement, mais ce n'est qu'après le milieu des années 90 que l'immigration en provenance de Chine s'est accélérée sous l'effet de la politique canadienne facilitant l'entrée au Canada des immigrants économiques et aussi de la progression de la classe moyenne en Chine. L'arrivée continue d'immigrants chinois instruits et originaires des villes est susceptible de modifier la composition de la population et la complexité identitaire de la communauté chinoise au Canada. EL AUMENTO Y CAÍDA DE LA INMIGRACIÓN CHINA AL CANADÁ: RECIÉN LLEGADOS DE LA REGIÓN ADMINISTRATIVA ESPECIAL DE HONG KONG1 Y DE CHINA, 1980,2000 En los estudios realizados sobre las diásporas en el mundo, se observa el efecto que tienen la globalización económica y los cambios migratorios en la reconfiguración de la población y en la conformación de comunidades de la diáspora. En este artículo se examinan los patrones de inmigración de Hong Kong y China al Canadá en los años ochenta y noventa, y se demuestra que los cambios en la migración resultan de fuerzas políticas y económicas en Hong Kong y China, así como de cambios en la política de inmigración del Canadá. La inminente devolución de Hong Kong a la China en 1997 y la incertidumbre sobre su futuro político, fueron consideradas como la principal razón de la numerosa inmigración de Hong Kong a finales de los años ochenta y principios de los noventa. En realidad, el creciente número de emigrantes de Hong Kong se debió al incidente en la Plaza de Tiananmen en China en 1989 y a sus consecuencias, y al auge económico de Hong Kong a principios de los años noventa, que permitió que la clase media china pudiera emigrar. Al mismo tiempo, la ampliación del Programa de Inmigración Empresarial instaurado por el Canadá a mediados de los años ochenta también atrajo a empresarios inmigrantes provenientes de Hong Kong. Por su parte, la crisis financiera asiática de 1997 no afectó el crecimiento económico en la China. La inmigración de China aumentó tras 1989, cuando el Canadá autorizó a la inmigración de los chinos que estudiaban en el Canadá, pero fue ulteriormente, a mediados de los años noventa, que la inmigración desde China se amplió debido a que el Canadá decidió aceptar a inmigrantes económicos y a la creciente clase media proveniente de China. La continua llegada de inmigrantes chinos instruidos y de zonas urbanas, probablemente afecte la composición y complejidad de la identidad de la población china en el Canadá. [source] Intravenous administration of melatonin reduces the intracerebral cellular inflammatory response following transient focal cerebral ischemia in ratsJOURNAL OF PINEAL RESEARCH, Issue 3 2007Ming-Yang Lee Abstract:, We have previously shown that exogenous melatonin improves the preservation of the blood,brain barrier (BBB) and neurovascular unit following cerebral ischemia,reperfusion. Recent evidence indicates that postischemic microglial activation exaggerates the damage to the BBB. Herein, we explored whether melatonin mitigates the cellular inflammatory response after transient focal cerebral ischemia for 90 min in rats. Melatonin (5 mg/kg) or vehicle was given intravenously at reperfusion onset. Immunohistochemistry and flow cytometric analysis were used to evaluate the cellular inflammatory response at 48 hr after reperfusion. Relative to controls, melatonin-treated animals did not have significantly changed systemic cellular inflammatory responses in the bloodstream (P > 0.05). Melatonin, however, significantly decreased the cellular inflammatory response by 41% (P < 0.001) in the ischemic hemisphere. Specifically, melatonin effectively decreased the extent of neutrophil emigration (Ly6G-positive/CD45-positive) and macrophage/activated microglial infiltration (CD11b-positive/CD45-positive) by 51% (P < 0.01) and 66% (P < 0.01), respectively, but did not significantly alter the population composition of T lymphocyte (CD3-positive/CD45-positive; P > 0.05). This melatonin-mediated decrease in the cellular inflammatory response was accompanied by both reduced brain infarction and improved neurobehavioral outcome by 43% (P < 0.001) and 50% (P < 0.001), respectively. Thus, intravenous administration of melatonin upon reperfusion effectively decreased the emigration of circulatory neutrophils and macrophages/monocytes into the injured brain and inhibited focal microglial activation following cerebral ischemia,reperfusion. The finding demonstrates melatonin's inhibitory ability against the cellular inflammatory response after cerebral ischemia,reperfusion, and further supports its pleuripotent neuroprotective actions suited either as a monotherapy or an add-on to the thrombolytic therapy for ischemic stroke patients. [source] An investigation on the Culicoides species composition at seven sites in southern SwitzerlandMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2009S. CASATI Abstract In the past decade, there have been regular outbreaks of bluetongue (BT) in many parts of Europe. Owing to the presence of BT disease and its vectors in countries adjacent to Switzerland, an initial entomological survey was conducted in 2003, which established the presence of several midges of the genus Culicoides (Diptera: Ceratopogonidae). Subsequently, a sentinel herd monitoring system was established with the primary entomological aim being the determination and further study of Culicoides population compositions. Insects were collected in 2005 and 2006 at seven sentinel herd sites in the south of Switzerland (canton of Ticino) near the border of Italy, using Onderstepoort-type light traps. This region is botanically and zoologically similar to the Mediterranean and is one of the warmest and most humid areas of the country, hence it is considered a potential access path for BT disease into Switzerland. Collections were made at four cattle farms, two equestrian centres and one goat farm. Sites were sampled four times per month from June to October. Traps were operated from dusk until dawn and samples were collected monthly for analysis through microscopy as well as a Culicoides imicola -specific PCR. Results confirmed the absence of C. imicola (Kieffer) and demonstrated that the potential BT virus vectors are highly abundant, notably: Culicoides obsoletus (Meigen), Culicoides scoticus (Downes & Kettle) and Culicoides dewulfi (Goetghebuer) subgenus Avaritia and Culicoides pulicaris (Linnaeus) subgenus Culicoides. These findings expand the current knowledge of Culicoides population composition in the southern part of the Switzerland. Culicoides cataneii (Clastrier), Culicoides flavipulicaris (Dzhafarov), Culicoides indistinctus (Khalaf), Culicoides nubeculosus (Meigen) and species of the Grisescens complex were reported for the first time in Switzerland. [source] What can the age composition of a population tell us about the age composition of its out-migrants?POPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 1 2007Jani S. Little Abstract Preliminary findings show that the age structure of a population can provide valuable information about the age composition of its out-migrants, and that this relationship can become a key ingredient in the proposed new method for estimating the age profile of out-migrants when accurate data are not available. The method relies on the Rogers-Castro model schedule to consistently and accurately represent age profiles of out-migration, and the results show that variation among these out-migration schedules can be captured by a typology based on a small set of clusters, or families of schedules. Membership of the clusters is then predicted from simple measures of population composition using discriminant function analysis. The investigation is based on data for US states, CMSAs, MSAs and non-metropolitan counties, and their outflows of migrants between 1995 and 2000. The measures of population age composition come from official 1995 intercensal age-specific population estimates for the same geographical units. Copyright © 2007 John Wiley & Sons, Ltd. [source] Influence of socioeconomic and cultural factors on rural healthAUSTRALIAN JOURNAL OF RURAL HEALTH, Issue 1 2009John R. Beard Abstract Objective:,To provide a framework for investigating the influence of socioeconomic and cultural factors on rural health. Design:,Discussion paper. Results:,Socioeconomic and cultural factors have long been thought to influence an individual's health. We suggest a framework for characterising these factors that comprises individual-level (e.g. individual socioeconomic status, sex, race) and neighbourhood-level dimensions (population composition, social environment, physical environment) operating both independently and through interaction. Recent spatial research suggests that in rural communities, socioeconomic disadvantage and indigenous status are two of the greatest underlying influences on health status. However, rural communities also face additional challenges associated with access to, and utilisation of, health care. The example is given of procedural angiography for individuals with an acute coronary event. Conclusions:,Socioeconomic and cultural factors specific to rural Australia are key influences on the health of residents. These range from individual-level factors, such as rural stoicism, poverty and substance use norms, to neighbourhood-level social characteristics, such as lack of services, migration out of rural areas of younger community members weakening traditionally high levels of social cohesion, and to environmental factors, such as climate change and access to services. [source] An investigation on the Culicoides species composition at seven sites in southern SwitzerlandMEDICAL AND VETERINARY ENTOMOLOGY, Issue 2 2009S. CASATI Abstract In the past decade, there have been regular outbreaks of bluetongue (BT) in many parts of Europe. Owing to the presence of BT disease and its vectors in countries adjacent to Switzerland, an initial entomological survey was conducted in 2003, which established the presence of several midges of the genus Culicoides (Diptera: Ceratopogonidae). Subsequently, a sentinel herd monitoring system was established with the primary entomological aim being the determination and further study of Culicoides population compositions. Insects were collected in 2005 and 2006 at seven sentinel herd sites in the south of Switzerland (canton of Ticino) near the border of Italy, using Onderstepoort-type light traps. This region is botanically and zoologically similar to the Mediterranean and is one of the warmest and most humid areas of the country, hence it is considered a potential access path for BT disease into Switzerland. Collections were made at four cattle farms, two equestrian centres and one goat farm. Sites were sampled four times per month from June to October. Traps were operated from dusk until dawn and samples were collected monthly for analysis through microscopy as well as a Culicoides imicola -specific PCR. Results confirmed the absence of C. imicola (Kieffer) and demonstrated that the potential BT virus vectors are highly abundant, notably: Culicoides obsoletus (Meigen), Culicoides scoticus (Downes & Kettle) and Culicoides dewulfi (Goetghebuer) subgenus Avaritia and Culicoides pulicaris (Linnaeus) subgenus Culicoides. These findings expand the current knowledge of Culicoides population composition in the southern part of the Switzerland. Culicoides cataneii (Clastrier), Culicoides flavipulicaris (Dzhafarov), Culicoides indistinctus (Khalaf), Culicoides nubeculosus (Meigen) and species of the Grisescens complex were reported for the first time in Switzerland. [source] | |||||||||||||