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Sample records for factors limiting population

  1. Limiting factors in caribou population ecology

    Directory of Open Access Journals (Sweden)

    David R. Klein

    1991-10-01

    Full Text Available Caribou and wild reindeer populations fluctuate over time. On this fact there is general agreement. Factors responsible for population limitation and subsequent declines have been examined within the framework of animal population theory. There is, however, little agreement when factors limiting specific populations are generalized to Rangifer populations over broad geographic regions. Comparative examinations of wild Rangifer populations worldwide discloses that factors that have regulated those populations are highly variable between populations, apparently as a reflection of the differences in environmental variables unique to each population. Examples exist of populations where major regulating factors have been climatic extremes, predation, hunting mortality, food limitation, insects, parasites, disease, interspecific competition, and human developmental impacts or combinations of these factors. This diversity of limiting factors affecting caribou and wild reindeer populations is a reflection of the ecologial complexity of the species, a concept that has often been ignored in past efforts to reach management decisions by extrapolation from the limited localized knowledge available on the species.

  2. Risk factors for mortality during antiretroviral therapy in older populations in resource-limited settings

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    Daniel O’Brien

    2016-01-01

    Full Text Available Introduction: An increasing proportion of adult patients initiating antiretroviral therapy (ART in resource-limited settings are aged >50 years. Older populations on ART appear to have heightened risk of death, but little is known about factors influencing mortality in this population. Methods: We performed a retrospective observational multisite cohort study including all adult patients (≥15 years initiating ART between 2003 and 2013 in programmes supported by Médecins Sans Frontières across 12 countries in Asia, Africa and Europe. Patients were stratified into two age groups, >50 years and 15 to 50 years. A Cox proportional hazards model was used to explore factors associated with mortality. Results: The study included 41,088 patients: 2591 (6.3% were aged >50 years and 38,497 (93.7% were aged 15 to 50 years. The mortality rate was significantly higher in the age group >50 years [367 (14.2% deaths; mortality rate 7.67 deaths per 100 person-years (95% confidence interval, CI: 6.93 to 8.50] compared to the age group 15 to 50 years [3788 (9.8% deaths; mortality rate 4.18 deaths per 100 person-years (95% CI: 4.05 to 4.31], p50 age group. WHO Stage 4 conditions were more strongly associated with increased mortality rates in the 15 to 50 age group compared to populations >50 years. WHO Stage 3 conditions were associated with an increased mortality rate in the 15 to 50 age group but not in the >50 age group. Programme region did not affect mortality rates in the >50 age group; however being in an Asian programme was associated with a 36% reduced mortality rate in populations aged 15 to 50 years compared to being in an African programme. There was a higher overall incidence of Stage 3 WHO conditions in people >50 years (12.8/100 person-years compared to those 15 to 50 years (8.1/100 person-years (p50 age groups. Conclusions: Older patients on ART in resource-limited settings have increased mortality rates, but compared to younger populations this

  3. Anatomy of a bottleneck: diagnosing factors limiting population growth in the Puerto Rican parrot

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    Beissenger, S.R.; Wunderle, J.M.; Meyers, J.M.; Saether, B.-E.; Engen, S.

    2008-01-01

    captive young into wild nests), diminishing the importance of nest failure as a limiting factor. Annual survival has been periodically reduced by catastrophes (hurricanes), which have greatly constrained population growth, but survival rates were high under non-catastrophic conditions. Although the importance of factors maintaining the Puerto Rican Parrot bottleneck varied throughout the 30-year period of study, we determined their long-term influence using LSA simulations to correlate variation in demographic rates with variation in population growth (k). The bottleneck appears to have been maintained primarily by periodic catastrophes (hurricanes) that reduced adult survival, and secondarily by environmental and/or behavioral factors that resulted in a failure of many adults to nest. The influence of inbreeding through reduced hatching success played a much less significant role, even when additional effects of inbreeding on the production and mortality of young were incorporated into the LSA. Management actions needed to speed recovery include (1) continued nest guarding to minimize the effects of nest failure due to nongenetic causes; (2) creating a second population at another location on the island --a process that was recently initiated--to reduce the chance that hurricane strikes will cause extinction; and (3) determining the causes of the low percentage of breeders in the population and ameliorating them, which would have a large impact on population growth.

  4. Blue duiker Philantomba monticola densities in the Tsitsikamma National Park and probable factors limiting these populations

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    N. Hanekom

    1991-09-01

    Full Text Available Numbers of blue duikers recorded on 157 and 28 variable width transect counts, done over a two year period in the Tsitsikamma Coastal National Park (TCNP and Tsitsikamma Forest National Park (TFNP respectively, did not differ significantly {P > 0,10 with seasons (summer v. winter. Population density estimates from transects were similar to those from game drives (0,18 v. 0,19 duikers/ha (TCNP and 0,13 v. 0,17 duikers/ha (TFNP; P >0,10, higher than from faecal pellet counts (P < 0,10 and at least three times lower than estimates from the Kenneth Stainbank Nature Reserve and Umdoni Park in Natal. Factors contributing to the low population densities in the Tsitsikamma national parks were investigated. Twentyseven and seven percent of leopard (25 and caracal (12 scats respectively analyzed contained blue duiker remains, but predator numbers appear to be low. Forest characteristics were investigated, and results from this and other studies suggest that undergrowth cover does not markedly influence blue duiker densities in the southern Cape forests. Field and stomach analysis indicate that blue duikers feed primarily on freshly fallen leaves and fruit, and are selective foragers. In the Tsitsikamma national parks (TNPs the frequency of occurrence of trees known to be palatable to duikers are low, while less than 45 percent of the dominant tree species fruit fully annually. This apparent scarcity of food, the low numbers of antelope species and individuals in these forests and results from duiker research in Zaire, suggest that habitat rather than predation is limiting duiker numbers in the Tsitsikamma national parks.

  5. Contaminants as a limiting factor of fish and wildlife populations in the Santa Cruz River, Arizona

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Declining populations of the endangered Gila topminnow in the Santa Cruz River prompted a 1997 study to assess contaminant levels in water, sediment, invertebrates,...

  6. Recent population size, trends, and limiting factors for the double-crested Cormorant in Western North America

    Science.gov (United States)

    Adkins, Jessica Y.; Roby, Daniel D.; Lyons, Donald E.; Courtot, Karen N.; Collis, Ken; Carter, Harry R.; Shuford, W. David; Capitolo, Phillip J.

    2014-01-01

    colonies by bald eagles (Haliaeetus leucocephalus) and humans are likely limiting factors on the growth of the western population at present. Because of differences in biology and management, the western population of double-crested cormorants warrants consideration as a separate management unit from the population east of the Continental Divide.

  7. Landscape genetics and limiting factors

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    Samuel A. Cushman; Andrew J. Shirk; Erin L. Landguth

    2013-01-01

    Population connectivity is mediated by the movement of organisms or propagules through landscapes. However, little is known about how variation in the pattern of landscape mosaics affects the detectability of landscape genetic relationships. The goal of this paper is to explore the impacts of limiting factors on landscape genetic processes using simulation...

  8. Democracy as a Limiting Factor for Politicised Cultural Populism in Malawi Demokratie und politisierter Kulturpopulismus in Malawi

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    Reuben Makayiko Chirambo

    2009-01-01

    Full Text Available Though Malawian democracy could still be described as in transition from authoritarianism, it has enabled an atmosphere for critical debate of and dissent against seemingly popular opinions, which was not possible during the authoritarian rule of former life president, Dr. H. K. Banda, 1964-1994. This article examines politicised cultural populism in Malawi under the dictatorship and democracy in comparative terms. President Banda, as a political populist, appropriated culture to legitimate and validate his political power as well as to cultivate popular support from the majority of ordinary people. Following reforms towards democracy since 1992, his successors have also tended towards populist politics by similarly appropriating culture and cultural activities, among other means, to cultivate popular support from mostly ordinary people for their regimes. Such politicised cultural populism involves adopting traditional roles, cultural symbols and images of power such as praise-titles, and participating in cultural activities such as traditional dances. This article examines the efforts of President Bingu wa Mutharika in the democratic dispensation to appropriate cultural artefacts used by Banda during a dictatorship in order to cultivate popular support for his regime. The article argues that Bingu’s efforts at politicised cultural populism are constrained, among other factors, by the nature and climate of democratic politics mainly because democracy, unlike a dictatorship, enables critical debate and the questioning of political leader’s behaviour and their motives. Auch wenn die Demokratie in Malawi sich immer noch in einem Übergangsstadium befindet, ist inzwischen eine Atmosphäre entstanden, in der eine kritische Debatte und das Äußern unpopulärer Meinungen möglich sind, was in den Jahren 1964-1994 unter dem früheren Präsidenten auf Lebenszeit, Dr. H. K. Banda, nicht denkbar war. Der Autor vergleicht die Nutzung von Elementen

  9. The population factor.

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    Kats, G

    1983-01-01

    Reducing population growth is essentil to Egypt's broader efforts to improve facilities, services, and the phsycial quality of life. Although a family planning program has existed since the mid-1950s, the 2.7% annual rate of population growth has not changed in 30 years. Nasser and the other "free officers" who seized power in 1952 became concerned about the adverse effects of the rapidly growing population, but perhaps out of concern with a possible religious backlash, they confined themselves to launching studies and subsidizing several dozen private family planning clinics. From 1962-72, the number of private clinics grew from 28 to 480, and family planning was introduced in government healthclinics in 1965. Such clinics are mainly located in rural areas and are staffed by doctors and other personnel who are not members of the local community and are not very effective at promoting family planning. Local girls and women called Rayadet were recruited to promote the idea to birth control in local communities. By 1970, 12.6% of Egyptians were using reliable contraception. A national survey 12 years later found 34% using contraception, buth the figure seems high. Approximately 60-65% of eligible couples would need to practice birth control for Egypt to reach a less than 1% annuel increase. The Egyptian government hopes to slow population growth to 1% by the year 2000, but major problems of motivation remain especially among the rural poor. Several factors may lead to success of the family planning effort: 1) financial and technical support from international family planning sources has grown rapidley and is likely to remain high; 2) the mortality rate has dropped from 17.8/1000 in 1952 to about half that level, while the rate of natural increase is about the same, suggesting that future reductions in the birth rate will translate to a reduced rate of natural increase, and that parents will be less reluctant to practice faimly planning if there is a greater chance

  10. What limits the Serengeti zebra population?

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    Grange, Sophie; Duncan, Patrick; Gaillard, Jean-Michel; Sinclair, Anthony R.E.; Gogan, Peter J.; Packer, Craig; Hofer, Heribert; Marion, East

    2004-01-01

    The populations of the ecologically dominant ungulates in the Serengeti ecosystem (zebra, wildebeest and buffalo) have shown markedly different trends since the 1960s: the two ruminants both irrupted after the elimination of rinderpest in 1960, while the zebras have remained stable. The ruminants are resource limited (though parts of the buffalo population have been limited by poaching since the 1980s). The zebras' resource acquisition tactics should allow them to outcompete the ruminants, but their greater spatial dispersion makes them more available to predators, and it has been suggested that this population is limited by predation. To investigate the mechanisms involved in the population dynamics of Serengeti zebra, we compared population dynamics among the three species using demographic models based on age-class-specific survival and fecundity. The only major difference between zebra and the two ruminants occurred in the first-year survival. We show that wildebeest have a higher reproductive potential than zebra (younger age at first breeding and shorter generation time). Nevertheless, these differences in reproduction cannot account for the observed differences in the population trends between the zebra and the ruminants. On the other hand, among-species differences in first-year survival are great enough to account for the constancy of zebra population size. We conclude that the very low first-year survival of zebra limits this population. We provide new data on predation in the Serengeti and show that, as in other ecosystems, predation rates on zebras are high, so predation could hold the population in a "predator pit". However, lion and hyena feed principally on adult zebras, and further work is required to discover the process involved in the high mortality of foals.

  11. Limiting factors of starch hydrolysis.

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    Colonna, P; Leloup, V; Buléon, A

    1992-10-01

    Foods appear as complex structures, in which starch may be present in different forms. These, including the molecular characteristics and the crystalline organization, depend on processing conditions and compositions of ingredients. The main changes in starch macro- and microstructures are the increase of surface area to volume ratio in the solid phase, the modification of the crystallinity as affected by gelatinization and gelation, and the depolymerization of amylose and amylopectin. Starch modification may be estimated by different methodologies, which should be selected according to the level of structure considered. When amylose and amylopectin are in solution, rapid and total hydrolysis leads to the formation of a mixture of linear oligosaccharides and branched alpha-limit dextrins. However, starch usually occurs in foods as solid structures. Structural factors of starchy materials influence their enzymic hydrolysis. A better understanding of the enzymatic process enables the identification of the structural factors limiting hydrolysis: diffusion of enzyme molecules, porosity of solid substrates, adsorption of enzymes onto solid substrates, and the catalytic event. A mechanistic modelling should be possible in the future.

  12. Will human populations be limited by food?

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    Warren, S. G.

    2016-12-01

    Historical examples of demographic change, in China, Italy, Nigeria, Utah, the Philippines, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are based on a logical fallacy in that they assume, in spite of the absence of necessary negative feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. The benign projections that have resulted from this assumption may have hindered efforts to make availability of birth-control a priority in development-aid. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations, because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food. Even if the fertility rate is maintained far in excess of 2, the population cannot grow if food is limiting. Without the agricultural advances of the 20thcentury, world population could not have grown as it did from 1.7 billion in 1900 to 6 billion in 2000. The food supply may be enhanced in the future by genetic engineering and other innovations, but it may be limited by water shortage, climate change, pollution, and energy

  13. Probabilistic models of population evolution scaling limits, genealogies and interactions

    CERN Document Server

    Pardoux, Étienne

    2016-01-01

    This expository book presents the mathematical description of evolutionary models of populations subject to interactions (e.g. competition) within the population. The author includes both models of finite populations, and limiting models as the size of the population tends to infinity. The size of the population is described as a random function of time and of the initial population (the ancestors at time 0). The genealogical tree of such a population is given. Most models imply that the population is bound to go extinct in finite time. It is explained when the interaction is strong enough so that the extinction time remains finite, when the ancestral population at time 0 goes to infinity. The material could be used for teaching stochastic processes, together with their applications. Étienne Pardoux is Professor at Aix-Marseille University, working in the field of Stochastic Analysis, stochastic partial differential equations, and probabilistic models in evolutionary biology and population genetics. He obtai...

  14. Evaluation of Factors Limiting Corneal Donation.

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    Röck, Daniel; Wude, Johanna; Yoeruek, Efdal; Bartz-Schmidt, Karl Ulrich; Röck, Tobias

    2016-11-15

    BACKGROUND This study aimed to investigate factors limiting corneal donation at the University Hospital Tübingen. MATERIAL AND METHODS We retrospectively studied all hospital deaths from January 2012 to December 2015, considering each deceased patient as a potential corneal donor. During this period an ophthalmic resident managed corneal donor procurement on a full-time basis. Various factors limiting corneal donation were examined. RESULTS Among the 3412 deaths, 2937 (86.1%) displayed nonfulfillment of corneal donation. Consent for corneal donation was obtained in 475 cases (13.9%). The mean annual corneal donation rate was 13.9 donors per 100 deaths (range: 11.2-17.8). The leading causes of nonfulfillment of corneal donations were refusal to donate (49.8%, 1698 cases) and medical contraindications (23.6%, 805 cases). After next-of-kin interview of 2173 potential donors (109 potential donors were excluded because of logistical problems), willingness to participate in corneal donation was present in 475 cases (21.9%), whereas in 1698 cases (78.1%) corneal donation was refused. CONCLUSIONS Our study showed refusal to donate is the most important factor limiting corneal donation. It seems that increasing the knowledge of people about corneal donation through public education and media are necessary to address the corneal shortage.

  15. Concern With Environmental Deterioration and Attitudes Toward Population Limitation

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    Barnett, Larry D.

    1970-01-01

    Analysis of Gallup Poll data of Junuary 1969 reveals weak association between concern about environmental deterioration and the recognition of need for eventual limitation of human population. Suggests that to increase favorable attitudes to population control, role of overpopulation in causing environmental deterioration needs to be presented to…

  16. Concern With Environmental Deterioration and Attitudes Toward Population Limitation

    Science.gov (United States)

    Barnett, Larry D.

    1970-01-01

    Analysis of Gallup Poll data of Junuary 1969 reveals weak association between concern about environmental deterioration and the recognition of need for eventual limitation of human population. Suggests that to increase favorable attitudes to population control, role of overpopulation in causing environmental deterioration needs to be presented to…

  17. Population dynamics of light-limited phytoplankton : Microcosm experiments

    NARCIS (Netherlands)

    Huisman, Jef

    This paper investigates the extent to which the predictions of an elementary model for light-limited growth are matched by laboratory experiments with light-limited phytoplankton. The model and experiments link the population dynamics of phytoplankton species with changes in the light gradient

  18. Population dynamics of light-limited phytoplankton : Microcosm experiments

    NARCIS (Netherlands)

    Huisman, Jef

    1999-01-01

    This paper investigates the extent to which the predictions of an elementary model for light-limited growth are matched by laboratory experiments with light-limited phytoplankton. The model and experiments link the population dynamics of phytoplankton species with changes in the light gradient cause

  19. Does pollen limitation affect population growth of the endangered Dracocephalum austriacum L.?

    NARCIS (Netherlands)

    S. Castro; T. Dostálek; S. van der Meer; G. Oostermeijer; Z. Münzbergová

    2015-01-01

    Reproductive strategies can have significant consequences for the viability of plant populations. Still, the effects of lower fruit set due to pollen limitation on plant demography and population persistence have rarely been explored. The objectives of this study were to assess the ecological factor

  20. Limit Theorems for Competitive Density Dependent Population Processes

    CERN Document Server

    Parsons, Todd L

    2010-01-01

    Near the beginning of the century, Wright and Fisher devised an elegant, mathematically tractable model of gene reproduction and replacement that laid the foundation for contemporary population genetics. The Wright-Fisher model and its extensions have given biologists powerful tools of statistical inference that enabled the quantification of genetic drift and selection. Given the utility of these tools, we often forget that their model - for mathematical, and not biological reasons - makes assumptions that are violated in most real-world populations. In this paper, I consider an alternative framework that merges P. A. P. Moran's continuous-time Markov chain model of allele frequency with the density dependent models of ecological competition proposed by Gause, Lotka and Volterra, that, unlike Moran's model allow for a stochastically varying -- but bounded -- population size. I require that allele numbers vary according to a density-dependent population process, for which the limiting law of large numbers is a...

  1. Population pressure on coral atolls: trends and approaching limits.

    Science.gov (United States)

    Rapaport, M

    1990-09-01

    Trends and approaching limits of population pressure on coral atolls is discussed by examining the atoll environment in terms of the physical geography, the production systems, and resource distribution. Atoll populations are grouped as dependent and independent, and demographic trends in population growth, migraiton, urbanization, and political dependency are reviewed. Examination of the carrying capacity includes a dynamic model, the influences of the West, and philopsophical considerations. The carrying capacity is the "maximal population supportable in a given area". Traditional models are criticized because of a lack in accounting for external linkages. The proposed model is dynamic and considers perceived needs and overseas linkages. It also explains regional disparities in population distribution, and provides a continuing model for population movement from outer islands to district centers and mainland areas. Because of increased expectations and perceived needs, there is a lower carrying capacity for outlying areas, and expanded capacity in district centers. This leads to urbanization, emigration, and carrying capacity overshot in regional and mainland areas. Policy intervention is necessary at the regional and island community level. Atolls, which are islands surrounding deep lagoons, exist in archipelagoes across the oceans, and are rich in aquatic life. The balance in this small land area with a vulnerable ecosystem may be easily disturbed by scarce water supplies, barren soils, rising sea levels in the future, hurricanes, and tsunamis. Traditionally, fisheries and horticulture (pit-taro, coconuts, and breadfruit) have sustained populations, but modern influences such as blasting, reef mining, new industrial technologies, population pressure, and urbanization threaten the balance. Population pressure, which has lead to pollution, epidemics, malnutrition, crime, social disintegration, and foreign dependence, is evidenced in the areas of Tuvalu, Kiribati

  2. Consequences of limited seed dispersal within simulated annual populations.

    Science.gov (United States)

    Bullock, Stephen H

    1976-09-01

    Theoretical analyses of the consequences of dispersal have been almost entirely limited to studies of colonization. A simulation model is constructed and analyzed to study the effects of dispersal within local plant populations. Rules for the growth and reproduction of individuals are deterministic and related only to competition with other plants. Rules for the dispersal of individual seeds are stochastic; the generalized seed shadow is negatively exponential. The analysis has several interesting results. 1) In small, dense populations of annuals, mortality and growth behavior are significantly affected by small-scale changes in dispersal. 2) Stable population size, at any life stage, is not environmentally fixed (e.g. by the number of safe sites) but is also a function of reproductive capacity and dispersal. 3) There is a minimum productive capability which must be exceeded for a population to be able to respond to increased dispersal. The responsive range of the parameters may be related to the grain of safe site distribution. 4) When the total number of seeds per generation is large, high dispersal decreases the number of germlings that are able to establish. 5) For plants that reach the growing stage, however, expected reproduction can exceed that of genotypes with greater reproductive capacity but less dispersal. 6) An uneven distribution of seeds is essential to a spatial patterning of mortality which can deter competitive extinction.

  3. The global limits and population at risk of soil-transmitted helminth infections in 2010

    OpenAIRE

    Pullan Rachel L; Brooker Simon J

    2012-01-01

    Abstract Background Understanding the global limits of transmission of soil-transmitted helminth (STH) species is essential for quantifying the population at-risk and the burden of disease. This paper aims to define these limits on the basis of environmental and socioeconomic factors, and additionally seeks to investigate the effects of urbanisation and economic development on STH transmission, and estimate numbers at-risk of infection with Ascaris lumbricoides, Trichuris trichiura and hookwo...

  4. Limits to the rate of adaptive substitution in sexual populations.

    Directory of Open Access Journals (Sweden)

    Daniel B Weissman

    Full Text Available In large populations, many beneficial mutations may be simultaneously available and may compete with one another, slowing adaptation. By finding the probability of fixation of a favorable allele in a simple model of a haploid sexual population, we find limits to the rate of adaptive substitution, Λ, that depend on simple parameter combinations. When variance in fitness is low and linkage is loose, the baseline rate of substitution is Λ₀ = 2NU , where N is the population size, U is the rate of beneficial mutations per genome, and is their mean selective advantage. Heritable variance v in log fitness due to unlinked loci reduces Λ by e⁻⁴(v under polygamy and e⁻⁸ (v under monogamy. With a linear genetic map of length R Morgans, interference is yet stronger. We use a scaling argument to show that the density of adaptive substitutions depends on s, N, U, and R only through the baseline density: Λ/R = F (Λ₀/R. Under the approximation that the interference due to different sweeps adds up, we show that Λ/R ~(Λ₀/R / (1 +2Λ₉/R , implying that interference prevents the rate of adaptive substitution from exceeding one per centimorgan per 200 generations. Simulations and numerical calculations confirm the scaling argument and confirm the additive approximation for Λ₀/R ~ 1; for higher Λ₀/R , the rate of adaptation grows above R/2, but only very slowly. We also consider the effect of sweeps on neutral diversity and show that, while even occasional sweeps can greatly reduce neutral diversity, this effect saturates as sweeps become more common-diversity can be maintained even in populations experiencing very strong interference. Our results indicate that for some organisms the rate of adaptive substitution may be primarily recombination-limited, depending only weakly on the mutation supply and the strength of selection.

  5. Fundamental limits to collective concentration sensing in cell populations

    CERN Document Server

    Fancher, Sean

    2016-01-01

    The precision of concentration sensing is improved when cells communicate. Here we derive the physical limits to concentration sensing for cells that communicate over short distances by directly exchanging small molecules (juxtacrine signaling), or over longer distances by secreting and sensing a diffusive messenger molecule (autocrine signaling). In the latter case, we find that the optimal cell spacing can be large, due to a tradeoff between maintaining communication strength and reducing signal cross-correlations. This leads to the surprising result that autocrine signaling allows more precise sensing than juxtacrine signaling for sufficiently large populations. We compare our results to data from a wide variety of communicating cell types.

  6. Resources, environment, and population: the nature of future limits.

    Science.gov (United States)

    Ridker, R G; Cecelski, E W

    1979-08-01

    The balance between world supplies of resources and the demands presented by population growth in the recent past, during the period to 2025, and for the long term is examined. Focus is on the issues, the past in terms of socioeconomic indicators, past trends in market places, and specific evidence of depletion; future demands in terms of population projections and growth in per capita demand; resource supplies to 2025; ultimate resource production possibilities; environmental constraints and risks (problems capable of control at reasonable cost, other domestic environmental problems, and potentially severe global problems); and implications. Improvement in socioeconomic indicators, relatively stable resource market prices, along with evidence of resource and environmental changes suggest that thus far the world as a whole has been able to win the race between demand and supply. For the next 50 years, during which a slowdown is projected in population growth rates and resource consumption, the most important problems to be faced are associated with the unequal distribution of resources and the transition problems of moving from 1 resource regime to another in an orderly fashion. For the long term, a projected equilibrium population of 10-12 billion can probably be sustained at a decent standard of living by more equitable distribution of food and shifts from less to more abundant resources. Ultimately, environmental and security problems associated with growing energy production and use such as increasing atmospheric levels of carbon dioxide and nuclear proliferation may be the most difficult to resolve. Although cessation of population growth would help, it does not by itself constitute a solution to the world's resource problems. Both the causes and the symptoms need to be worked on simultaneously. Understanding the true nature of the world's resource and environmental limitations is a 1st step in that direction.

  7. Metabolic factors limiting performance in marathon runners.

    Directory of Open Access Journals (Sweden)

    Benjamin I Rapoport

    Full Text Available Each year in the past three decades has seen hundreds of thousands of runners register to run a major marathon. Of those who attempt to race over the marathon distance of 26 miles and 385 yards (42.195 kilometers, more than two-fifths experience severe and performance-limiting depletion of physiologic carbohydrate reserves (a phenomenon known as 'hitting the wall', and thousands drop out before reaching the finish lines (approximately 1-2% of those who start. Analyses of endurance physiology have often either used coarse approximations to suggest that human glycogen reserves are insufficient to fuel a marathon (making 'hitting the wall' seem inevitable, or implied that maximal glycogen loading is required in order to complete a marathon without 'hitting the wall.' The present computational study demonstrates that the energetic constraints on endurance runners are more subtle, and depend on several physiologic variables including the muscle mass distribution, liver and muscle glycogen densities, and running speed (exercise intensity as a fraction of aerobic capacity of individual runners, in personalized but nevertheless quantifiable and predictable ways. The analytic approach presented here is used to estimate the distance at which runners will exhaust their glycogen stores as a function of running intensity. In so doing it also provides a basis for guidelines ensuring the safety and optimizing the performance of endurance runners, both by setting personally appropriate paces and by prescribing midrace fueling requirements for avoiding 'the wall.' The present analysis also sheds physiologically principled light on important standards in marathon running that until now have remained empirically defined: The qualifying times for the Boston Marathon.

  8. Energy and population: transitional issues and eventual limits.

    Science.gov (United States)

    Werbos, P J

    1990-08-01

    The implication of population size for US energy requirements is explored in this essay. The basic argument is that the present supply of fuels and energy technologies is not sustainable in the long run, that a wide range of choices is possible when a complete transition is made to sustainable technologies, and that the growth of population and the composition of this growth during the next 30 years are the most serious problems impacting on the achievement of sustainable technology. The importance and future of fuel oil is discussed as well as the transition to sustainable energy supplies: conservation, renewables, nuclear and coal. Dependency on oil can only be changed through time and the infusion of money, but even with these givens, the transition is also dependent on the political and budgetary climate. The race is between crisis and cure. It is argued that the soft energy systems (biomass, solar water heater, wind, hydro, and geothermal energy) along with conservation will increase easily and naturally, but the total potential from these sources amounts to only 10% of the present US energy supply. Conservation offers greater hope because 80% of end-use fossil fuel is used in transportation and industry. Further growth of the population in the US would create a demand to desalinate water, which would increase the demand for energy. A totally soft energy economy is probably not feasible without a drastic reduction in US population. The expected direction is in the increased use of coal, and then nuclear energy. Unfortunately, coal contributes to greenhouse warming, and the supply is limited to 60-100 years. Nuclear proliferation and terrorism is connected to the widespread use of nuclear energy. Some breakthrough technology with cold fusion may offer a safer alternative. High technology renewables such as solar cells can be competitive with nuclear energy, if prices can be kept down. on earth or in space, are being investigated. Exploring a variety of advanced

  9. The density dilemma: limitations on juvenile production in threatened salmon populations

    Science.gov (United States)

    Walters, Annika W.; Copeland, Timothy; Venditti, David A.

    2013-01-01

    Density-dependent processes have repeatedly been shown to have a central role in salmonid population dynamics, but are often assumed to be negligible for populations at low abundances relative to historical records. Density dependence has been observed in overall spring/summer Snake River Chinook salmon Oncorhynchus tshawytscha production, but it is not clear how patterns observed at the aggregate level relate to individual populations within the basin. We used a Bayesian hierarchical modelling approach to explore the degree of density dependence in juvenile production for nine Idaho populations. Our results indicate that density dependence is ubiquitous, although its strength varies between populations. We also investigated the processes driving the population-level pattern and found density-dependent growth and mortality present for both common life-history strategies, but no evidence of density-dependent movement. Overwinter mortality, spatial clustering of redds and limited resource availability were identified as potentially important limiting factors contributing to density dependence. The ubiquity of density dependence for these threatened populations is alarming as stability at present low abundance levels suggests recovery may be difficult without major changes. We conclude that density dependence at the population level is common and must be considered in demographic analysis and management.

  10. Quantifying environmental limiting factors on tree cover using geospatial data.

    Directory of Open Access Journals (Sweden)

    Jonathan A Greenberg

    Full Text Available Environmental limiting factors (ELFs are the thresholds that determine the maximum or minimum biological response for a given suite of environmental conditions. We asked the following questions: 1 Can we detect ELFs on percent tree cover across the eastern slopes of the Lake Tahoe Basin, NV? 2 How are the ELFs distributed spatially? 3 To what extent are unmeasured environmental factors limiting tree cover? ELFs are difficult to quantify as they require significant sample sizes. We addressed this by using geospatial data over a relatively large spatial extent, where the wall-to-wall sampling ensures the inclusion of rare data points which define the minimum or maximum response to environmental factors. We tested mean temperature, minimum temperature, potential evapotranspiration (PET and PET minus precipitation (PET-P as potential limiting factors on percent tree cover. We found that the study area showed system-wide limitations on tree cover, and each of the factors showed evidence of being limiting on tree cover. However, only 1.2% of the total area appeared to be limited by the four (4 environmental factors, suggesting other unmeasured factors are limiting much of the tree cover in the study area. Where sites were near their theoretical maximum, non-forest sites (tree cover < 25% were primarily limited by cold mean temperatures, open-canopy forest sites (tree cover between 25% and 60% were primarily limited by evaporative demand, and closed-canopy forests were not limited by any particular environmental factor. The detection of ELFs is necessary in order to fully understand the width of limitations that species experience within their geographic range.

  11. Factors Related to Suicide in LGBT Populations.

    Science.gov (United States)

    Skerrett, Delaney Michael; Kõlves, Kairi; De Leo, Diego

    2016-09-01

    There is evidence of heightened vulnerability to nonfatal suicidal behaviors among LGBT populations yet a paucity of studies into fatal behaviors. The specific aim of this article was to identify factors related to suicide in LGBT individuals in Australia. The psychological autopsy (PA) method with a matched case-control study design was used. PA interviews were conducted with 27 next-of-kin of an LGBT person that had died by suicide. Three living LGBT controls per suicide case, matched by age and gender, were also interviewed. The key factors relating to suicide in LGBT people were a lack of acceptance by family and self (reflected in higher internalized homophobia and shame), negative feelings about own sexuality/gender, and dissatisfaction with appearance. LGBT people who died by suicide also tended to go through coming out milestones 2 years earlier than controls. There was a higher prevalence of aggressive behaviors and a more predominant history of physical and sexual abuse. Additionally, there was greater incidence of depression and anxiety and alcohol and substance use disorders. Specific predictive factors for suicide in LGBT populations in Australia were identified, including significantly poorer mental health outcomes and more violence across an array of measures.

  12. Cannibalism, food limitation, intraspecific competition, and the regulation of spider populations.

    Science.gov (United States)

    Wise, David H

    2006-01-01

    Cannibalism among generalist predators has implications for the dynamics of terrestrial food webs. Spiders are common, ubiquitous arthropod generalist predators in most natural and managed terrestrial ecosystems. Thus, the relationship of spider cannibalism to food limitation, competition, and population regulation has direct bearing on basic ecological theory and applications such as biological control. This review first briefly treats the different types of spider cannibalism and then focuses in more depth on evidence relating cannibalism to population dynamics and food web interactions to address the following questions: Is cannibalism in spiders a foraging strategy that helps to overcome the effects of a limited supply of calories and/or nutrients? Does cannibalism in spiders reduce competition for prey? Is cannibalism a significant density-dependent factor in spider population dynamics? Does cannibalism dampen spider-initiated trophic cascades?

  13. Population Limitation and the Wolves of Isle Royale

    National Research Council Canada - National Science Library

    Rolf O. Peterson; Nancy J. Thomas; Joanne M. Thurber; John A. Vucetich; Thomas A. Waite

    1998-01-01

    Population regulation for gray wolves in Isle Royale National Park, Michigan, was examined in 1987-1995 when wolves were in chronic decline following a crash of the population in 1981-1982. Canine parvovirus (CPV-2...

  14. 13 Factors Limiting Women's Involvement in Development: Lesson ...

    African Journals Online (AJOL)

    Nekky Umera

    the persistent and increasing burdens of poverty, malnutrition, poor health ... This paper investigates factors limiting an active involvement of rural women in .... and children, but decisions on economic and political issues are solely undertaken ...

  15. Critical Success Factors for Limited Service Hotels in Malaysia

    OpenAIRE

    Wong, Chee Keng

    2015-01-01

    Critical success factors were used originally in Information technology areas when it was first introduced but has since been applied generically in other industries. This study explores the critical success factors for limited service hotels in Malaysia from both customer and hotel operator/ business owners’ perspective. The literature presents information from tourism in general and in Malaysia, definition of limited service hotels and its relevance to the hospitality industry in Malaysia, ...

  16. Is iron a limiting factor of Nodularia spumigena blooms?

    Directory of Open Access Journals (Sweden)

    Lidia Paczuska

    2003-12-01

    Full Text Available It is well known that a deficiency of iron, a trace element essential to every living organism, limits the growth of algae and cyanobacteria. Nodularia spumigena Mertens is a blue-green algae species inhabiting the Baltic region that often forms toxic blooms.     The aim of the study was to assess the growth of the toxic cyanobacteria with respect to iron bioavailability. The measured growth parameters were the numbers of cells (optical density, chlorophyll a and pheopigment a concentrations. The iron concentrations used ranged from 10-7 to 10-4 mol dm-3. Under iron stress conditions (<5 × 10-7 mol dm-3, growth inhibition, gradual pigment decay and cell mortality were observed. However, enriching the medium with complexing factors like citric acid and EDTA significantly stimulated the growth rate and chlorophyll a production. The citric acid - EDTA - Fe (5 × 10-7 mol dm-3 complex was demonstrably effective in stimulating the rate of cell division. Starting with 10-6 mol dm-3, the higher the iron(III concentration used in the media, the more intensive the growth of the cyanobacteria populations. This was most rapid in the presence of high iron concentrations (10-4 mol dm-3, regardless of the presence of complexing agents.     It appears that the growth of toxic cyanobacteria N. spumigena, and thus also its ability to form blooms, may well depend on iron availability in the environment.

  17. LIMITING FACTORS FOR THE DEVELOPMENT OF THE SERBIAN HOSPITALITY INDUSTRY

    OpenAIRE

    Nikolina Kosar; Sasa Masic; Lidija Barjaktarovic; Mihaela Lazovic

    2016-01-01

    Heterogeneity and complexity determine multidisciplinary approach to the hospitality research. Identification and analysis of limited hospitality development factors imply very complex scientific approach. Case study methodology is applied on Republic of Serbia, which is transition country and candidate for EU accession. Research results identified key factors which had impact on lag, stagnation and contemporary level of hospitality development. Firstly, way of executed privatizat...

  18. Dynamics of competitive systems with a single common limiting factor.

    Science.gov (United States)

    Kon, Ryusuke

    2015-02-01

    The concept of limiting factors (or regulating factors) succeeded in formulating the well-known principle of competitive exclusion. This paper shows that the concept of limiting factors is helpful not only to formulate the competitive exclusion principle, but also to obtain other ecological insights. To this end, by focusing on a specific community structure, we study the dynamics of Kolmogorov equations and show that it is possible to derive an ecologically insightful result only from the information about interactions between species and limiting factors. Furthermore, we find that the derived result is a generalization of the preceding work by Shigesada, Kawasaki, and Teramoto (1984), who examined a certain Lotka-Volterra equation in a different context.

  19. Population limitation and the wolves of Isle Royale

    Science.gov (United States)

    Peterson, R.O.; Thomas, N.J.; Thurber, J.M.; Vucetich, J.A.; Waite, T.A.

    1998-01-01

    Population regulation for gray wolves in Isle Royale National Park, Michigan, was ex- amined in 1987-1995 when wolves were in chronic decline following a crash of the pop- ulation in 1981-1982. Canine parvovirus (CPV-2) was probably influential during the crash, but it disappeared by the lae 1980s. High mortality abruptly ceased after 1988, but low recruitment in the absence of disease and obvious shortage of food prevented recovery of the wolf population. In 1983-1995, with a comparable number of moose '10 years old as potential prey, wolves were only half as numerous as in 1959-1980. A simulation of annual fluctuations in effective population size (Ne) for wolves on Isle Royale suggests that their genetic heterozygosity has declined ca. 13% with each generation and ca. 80% in the 50- year history of this population. Inbreeding depression and stochastic demographic variation both remain possible explanations for recent low recruitment.

  20. Response to phosphorus limitation varies among lake populations of the freshwater snail Potamopyrgus antipodarum.

    Directory of Open Access Journals (Sweden)

    Amy C Krist

    Full Text Available Local adaptation--typically recognized as higher values of fitness-related traits for native vs. non-native individuals when measured in the native environment--is common in natural populations because of pervasive spatial variation in the intensity and type of natural selection. Although local adaptation has been primarily studied in the context of biotic interactions, widespread variation in abiotic characteristics of environments suggests that local adaptation in response to abiotic factors should also be common. Potamopyrgus antipodarum, a freshwater New Zealand snail that is an important model system for invasion biology and the maintenance of sexual reproduction, exhibits local adaptation to parasites and rate of water flow. As an initial step to determining whether P. antipodarum are also locally adapted to phosphorus availability, we examined whether populations differ in their responses to phosphorus limitation. We found that field-collected juvenile P. antipodarum grew at a lower rate and reached an important size threshold more slowly when fed a relatively low vs. a relatively high-phosphorus diet. We also detected significant across-population variation in individual growth rate. A marginally significant population-by-dietary phosphorus interaction along with a two-fold difference across populations in the extent of suppression of growth by low phosphorus suggests that populations of P. antipodarum may differ in their response to phosphorus limitation. Local adaptation may explain this variation, with the implication that snails from lakes with relatively low phosphorus availability should be less severely affected by phosphorus limitation than snails from lakes with higher phosphorus availability.

  1. Factors affecting food selection in Canadian population.

    Science.gov (United States)

    Ree, M; Riediger, N; Moghadasian, M H

    2008-11-01

    To establish health-related reasons behind Canadian food choices, and how variables such as education, income, gender, ethnicity and age may affect food selection. Approximately 98 733 Canadians responded to the 12 questions regarding food choices in the Canadian Community Health Survey (CCHS) cycle 2.1, conducted by the Canadian Government in 2003. These included 13 727 adolescents (12-19 years), 19 089 young adults (20-34 years), 31 039 middle-aged adults (35-54 years), 25 338 older adults (55-74 years) and 9580 elderly (75+ years). Approximately 70% of Canadian adolescents in the sample indicated that their food choices were independent of health concerns. Body weight management was a major concern for food selection by adolescents and adults, while the elderly stated heart disease as their main concern. Among all participants, females, and individuals with high levels of education and income reported the highest response to choosing or avoiding foods due to health concerns and food content. Our data indicate that several factors significantly affect food choices for health-related reasons in the Canadian population. Among them, age- and gender-related gaps, particularly between adolescents and adults, are profound. This observation may urge authorities to implement effective strategies to educate Canadians, especially adolescents, that selection of appropriate foods may prevent chronic diseases.

  2. Corn Response to Competition: Growth Alteration vs. Yield Limiting Factors

    Science.gov (United States)

    Understanding competition mechanisms among adjacent plants can improve site-specific management recommendations. This 2-yr study compared two hypotheses, yield limiting factors vs. behavior modification, to explain plant interactions. Corn was grown under different levels of stress by varying light ...

  3. Quantifying Environmental Limiting Factors on Tree Cover Using Geospatial Data

    NARCIS (Netherlands)

    Greenberg, Jonathan; Ferreira Dos Santos, Maria Joao; Dobrowski, Solomon; Vanderbilt, Vern; Ustin, Susan

    2015-01-01

    Environmental limiting factors (ELFs) are the thresholds that determine the maximum or minimum biological response for a given suite of environmental conditions. We asked the following questions: 1) Can we detect ELFs on percent tree cover across the eastern slopes of the Lake Tahoe Basin, NV? 2) Ho

  4. Factors limiting heterotrophic bacterial production in the southern Pacific Ocean

    Directory of Open Access Journals (Sweden)

    F. Van Wambeke

    2007-10-01

    Full Text Available The role of potential factors limiting bacterial growth was investigated along vertical and longitudinal gradients across the South Eastern Pacific Gyre. The effects of glucose, nitrate, ammonium and phosphate additions on heterotrophic bacterial production (using leucine technique were studied in parallel in unfiltered seawater samples incubated under natural daily irradiance. Longitudinally, the enrichments realized on the subsurface showed three types of responses. From the Marquesas plateau (8° W to approx 125° W, bacteria were not bottom-up controlled, as confirmed by the huge potential of growth in non-enriched seawater (43±24 times in 24 h. Within the Gyre (125° W–95° W, nitrogen alone stimulated leucine incorporation rates by a factor of 5.6±3.6, but rapidly labile carbon (glucose became a second limiting factor (enhancement factor 49±32 when the two elements were added. Finally from the border of the gyre to the Chilean upwelling (95° W–73° W, labile carbon was the only factor stimulating heterotrophic bacterial production. Interaction between phytoplankton and heterotrophic bacterial communities and the direct versus indirect effect of iron and macronutrients on bacterial production were also investigated in four selected sites: two sites on the vicinity of the Marquesas plateau, the centre of the gyre and the Eastern border of the gyre. Both phytoplankton and heterotrophic bacteria were limited by availability of nitrogen within the gyre, but not by iron. While iron limited phytoplankton at Marquesas plateau and at the eastern border of the gyre, heterotrophic bacteria were only limited by availability of labile DOC in those environments.

  5. Disease limits populations: plague and black-tailed prairie dogs.

    Science.gov (United States)

    Cully, Jack F; Johnson, Tammi L; Collinge, Sharon K; Ray, Chris

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  6. Disease limits populations: plague and black-tailed prairie dogs

    Science.gov (United States)

    Cully, Jack F.; Johnson, T.; Collinge, S.K.; Ray, C.

    2010-01-01

    Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

  7. The global limits and population at risk of soil-transmitted helminth infections in 2010

    Directory of Open Access Journals (Sweden)

    Pullan Rachel L

    2012-04-01

    Full Text Available Abstract Background Understanding the global limits of transmission of soil-transmitted helminth (STH species is essential for quantifying the population at-risk and the burden of disease. This paper aims to define these limits on the basis of environmental and socioeconomic factors, and additionally seeks to investigate the effects of urbanisation and economic development on STH transmission, and estimate numbers at-risk of infection with Ascaris lumbricoides, Trichuris trichiura and hookworm in 2010. Methods A total of 4,840 geo-referenced estimates of infection prevalence were abstracted from the Global Atlas of Helminth Infection and related to a range of environmental factors to delineate the biological limits of transmission. The relationship between STH transmission and urbanisation and economic development was investigated using high resolution population surfaces and country-level socioeconomic indicators, respectively. Based on the identified limits, the global population at risk of STH transmission in 2010 was estimated. Results High and low land surface temperature and extremely arid environments were found to limit STH transmission, with differential limits identified for each species. There was evidence that the prevalence of A. lumbricoides and of T. trichiura infection was statistically greater in peri-urban areas compared to urban and rural areas, whilst the prevalence of hookworm was highest in rural areas. At national levels, no clear socioeconomic correlates of transmission were identified, with the exception that little or no infection was observed for countries with a per capita gross domestic product greater than US$ 20,000. Globally in 2010, an estimated 5.3 billion people, including 1.0 billion school-aged children, lived in areas stable for transmission of at least one STH species, with 69% of these individuals living in Asia. A further 143 million (31.1 million school-aged children lived in areas of unstable

  8. The population factor in economic growth theory

    NARCIS (Netherlands)

    Meilink, H.A.

    1974-01-01

    Reviews briefly the role of population growth in economic growth theory and makes a few critical remarks on the applied methodology and the underlying assumptions. Emphasis is laid on the possible relationships between population and economic growth in the developing countries, but also Malthus' the

  9. Factors impacting on the nutritional status of population aged 45 ...

    African Journals Online (AJOL)

    Factors impacting on the nutritional status of population aged 45 years and ... Information on selected demographic and socio-economic household ... and obesity are problems facing this population group aged 45 years and above in Nairobi.

  10. Population Distribution and Influencing Factors Based on ESDA

    Institute of Scientific and Technical Information of China (English)

    Lv Chen; Fan Jie; Sun Wei

    2012-01-01

    Based on the exploratory spatial data analysis (ESDA) technique and geographic information system (GIS) platform, with statistic data of counties in 2005, this paper confirms that there is a large population density gap between counties in 2005 because the Gini coefficient is 0.55. Population distribution does not change a lot during the past decades, and the southeast China is still much more densely populated than the northwest China. The global spa- tial autoeorrelation of population distribution is obvious because Moran's I scores 0.42 and local spatial autocorrelation is partly significant. Climate and elevation are still the main natural influ- encing factors. Meanwhile industrial structure and transportation significantly influence population distribution. Different combinations of natural factors have different effects on population distribution. For a long term, climate and terrain factor stability affect population distribution. But its influence will be weakened by progress of technology. Economic development is the main factor that changes population distribution for a short term.

  11. Methadone Deaths: Risk Factors in Pain and Addicted Populations

    National Research Council Canada - National Science Library

    Modesto-Lowe, Vania; Brooks, Donna; Petry, Nancy

    2010-01-01

    .... In this paper, we evaluate risk factors for methadone mortality in opioid dependent and pain populations and present guidelines for initiating methadone treatment in these two populations to minimize the risk of death...

  12. Fundamental Limits to Collective Concentration Sensing in Cell Populations

    Science.gov (United States)

    Fancher, Sean; Mugler, Andrew

    2017-02-01

    The precision of concentration sensing is improved when cells communicate. Here we derive the physical limits to concentration sensing for cells that communicate over short distances by directly exchanging small molecules (juxtacrine signaling), or over longer distances by secreting and sensing a diffusive messenger molecule (autocrine signaling). In the latter case, we find that the optimal cell spacing can be large, due to a trade-off between maintaining communication strength and reducing signal cross-correlations. This leads to the surprising result that sparsely packed communicating cells sense concentrations more precisely than densely packed communicating cells. We compare our results to data from a wide variety of communicating cell types.

  13. [Population pressure: a factor of political destabilization].

    Science.gov (United States)

    Tallon, F

    1993-04-01

    Political stability throughout the world appears to be greater in countries with slowly growing populations than in those with rapid growth. Population is not the only influence on political stability, however. The relationship between political stability and development is strong. The rich countries with the slowest growth are the most stable, while poor developing countries with rapid growth suffer from chronic instability. Demographic pressure and density are not the same thing and must be distinguished. A fragile environment like that of the Sahel will experience demographic pressure despite low density. Japan has a greater population density than Rwanda and little cultivable land, but the population has a high standard of living. demographic pressure is not comparable in Japan and Rwanda because Japan has slow population growth and stable democratic political institutions. The rate of growth seems to be a more important element in destabilization than density. Rapid growth creates enormous political tensions especially when profound ethnic divisions exist, and it complicates problems of government by encouraging rapid urbanization. The unbalanced age structures resulting from rapid growth hinder the satisfaction of employment, educational, and health care needs for the ever-increasing masses of young people. 49% of Rwanda's population is under 15 and 66% is under 25. Rwanda is already densely populated, with around 300 inhabitants/sq km, and its population is projected to double in 20 years. 95% of the population is dependent on agriculture, but by 1988 the average landholding per family was only 1.25 hectares and 58% of families did not grown sufficient food for household needs. Further reduction in the size of holdings or a growing landless population will have multiple consequences. Urban migration will inevitably increase, bringing with it all the problems so evident in other poor countries where the process is more advanced than in Rwanda. Chaotic

  14. Massive three-loop form factor in the planar limit

    CERN Document Server

    Henn, Johannes; Smirnov, Vladimir A; Steinhauser, Matthias

    2016-01-01

    We compute the three-loop QCD corrections to the massive quark-anti-quark-photon form factors $F_1$ and $F_2$ in the large-$N_c$ limit. The analytic results are expressed in terms of Goncharov polylogarithms. This allows for a straightforward numerical evaluation. We also derive series expansions, including power suppressed terms, for three kinematic regions corresponding to small and large invariant masses of the photon momentum, and small velocities of the heavy quarks.

  15. Ultracool Subdwarfs: The Halo Population Down to the Substellar Limit

    CERN Document Server

    Burgasser, Adam J; Lodieu, Nicolas; Scholz, Ralf-Dieter; Delorme, Phillippe; Jao, Wei-Chun; Swift, Brandon J; Cushing, Michael C

    2008-01-01

    Ultracool subdwarfs are low luminosity, late-type M and L dwarfs that exhibit spectroscopic indications of subsolar metallicity and halo kinematics. Their recent discovery and ongoing investigation have led to new insights into the role of metallicity in the opacity structure, chemistry (e.g. dust formation) and evolution of low-temperature atmospheres; the long-term evolution of magnetic activity and angular momentum amongst the lowest-mass stars; the form of the halo luminosity and mass functions down to the hydrogen-burning mass limit; and even fundamental issues such as spectral classification and absolute brightness scales. This Splinter Session was devoted to bringing advances in observational and theoretical ultracool subdwarf research to the attention of the low-mass stellar and brown dwarf communities, as well as to share results among ultracool subdwarf enthusiasts.

  16. Population as an Economic Development Factor: the Case of Kosovo

    Directory of Open Access Journals (Sweden)

    Rahmije MUSTAFA-TOPXHIU

    2017-07-01

    Full Text Available Kosovo's population is a young population and is gradually entering the final stage of demographic transition, that is characterized by considerable decline in fertility, natality, mortality and natural growth. Despite demographic disturbances caused by numerous social and economic factors, the long period under Serbian occupation, major population displacement and the War of 1999, the population of Kosovo over the last hundred years have continued to increase, with high and low fluctuations. Kosovo population remains one of the populations with the highest growth in the region and broader. The objective of this study is to present and analyse the main charachteristics and trends of population of Kosovo.

  17. Factors of Addiction: New Jersey Correctional Population

    Science.gov (United States)

    Wojtowicz, James P.; Liu, Tongyin; Hedgpeth, G. Wayne

    2007-01-01

    Most state inmates incarcerated under the jurisdiction of the New Jersey Department of Corrections are driven to crimes by drug abuse. Understanding the factors contributing to addiction is the first step in developing strategies for successful inmate reintegration. This study presents an analysis of inmate addiction and factor association using…

  18. Limiting factors for reforestation of mine spoils from Galicia (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Vega, F.A.; Covelo, E.F.; Andrade, M.L. [University of Vigo, Vigo (Spain)

    2005-02-01

    Mined areas are a continuing source of heavy metals and acidity that move off site in response to erosion. Revegetation of the mine tailings could limit the spread of these heavy metals and acidity. This study was conducted to evaluate, at four tailings on opencast mines of Galicia (Touro: copper mine; and Meirama: lignite mine, NW Spain), the chemical and physical soil quality indicators and limiting edaphic factors concerning forest production. Selected zones were: (1) The tailings formed by the waste materials from the depleted Touro mine; (2) the decantation site of deposited sludge coming from the copper extraction in the flotation stage; (3) and (4) tailings of 3 and 10 years old of the Meirama lignite mine. The main physical limitations of the mine soils are the low effective depth ({lt} 50cm), high stoniness ({gt} 30 percent) and high porosity ({gt} 60 percent); which make them vulnerable to soil erosion and seriously interferes with the forest production. Soils coming from the decantation site of copper mine do not have physical limitations. The main chemical limitations of mine soils are their acidity (pH from 3.62 to 5.71), and aluminium saturation ({gt} 60 per cent in copper mine soils, and {gt} 20 per cent in lignite mine soils), low CECe (from 5.34 to 9.47 cmol{sub +}) kg{sup -1}), organic carbon (from 0.47 to 7.52 mg kg{sup -1}) and Ca{sup 2+} and Mg{sup 2+} contents, and imbalance between exchange bases. Lime and organic amendments are the most important factors in providing a suitable medium for plant growth.

  19. LIMITING FACTORS FOR THE DEVELOPMENT OF THE SERBIAN HOSPITALITY INDUSTRY

    Directory of Open Access Journals (Sweden)

    Nikolina Kosar

    2016-12-01

    Full Text Available Heterogeneity and complexity determine multidisciplinary approach to the hospitality research. Identification and analysis of limited hospitality development factors imply very complex scientific approach. Case study methodology is applied on Republic of Serbia, which is transition country and candidate for EU accession. Research results identified key factors which had impact on lag, stagnation and contemporary level of hospitality development. Firstly, way of executed privatization process of hospitality companies in Serbia i.e. only ownership transformation, as part of business transformation, was done (organizational, management, technological, financial and human resources parts of business transformation didn’t implement. Secondly, non-acceptable terms and conditions of credit lines for financing privatization and future business of privatized hospitality companies. Furthermore, buyers of privatized hospitality companies didn’t prepared adequate projections of cash flow and sources of financing (owned and borrowed. Finally, technological development and human resources were result of the first mentioned limited factor. In order to improve business in hospitality industry in transition economies, all stakeholders should be involved. State should improve business environment. Educational institutions should create applicable programs on market. Investors should be ready to invest in technological and human resource development. Banks should implement the best financing practice from headquarters in EU.

  20. Radiation Pressure Acceleration: the factors limiting maximum attainable ion energy

    CERN Document Server

    Bulanov, S S; Schroeder, C B; Bulanov, S V; Esirkepov, T Zh; Kando, M; Pegoraro, F; Leemans, W P

    2016-01-01

    Radiation pressure acceleration (RPA) is a highly efficient mechanism of laser-driven ion acceleration, with with near complete transfer of the laser energy to the ions in the relativistic regime. However, there is a fundamental limit on the maximum attainable ion energy, which is determined by the group velocity of the laser. The tightly focused laser pulses have group velocities smaller than the vacuum light speed, and, since they offer the high intensity needed for the RPA regime, it is plausible that group velocity effects would manifest themselves in the experiments involving tightly focused pulses and thin foils. However, in this case, finite spot size effects are important, and another limiting factor, the transverse expansion of the target, may dominate over the group velocity effect. As the laser pulse diffracts after passing the focus, the target expands accordingly due to the transverse intensity profile of the laser. Due to this expansion, the areal density of the target decreases, making it trans...

  1. Resources, Environment, and Population: The Nature of Future Limits. Population Bulletin, Vol. 34, No. 3, August 1979.

    Science.gov (United States)

    Ridker, Ronald G.; Cecelski, Elizabeth W.

    To determine the current status and possible trends in the balance between global population growth and natural resources, the bulletin examines demands presented by population and economic growth at various periods throughout history. Periods examined are the recent past, the present to the year 2025, and the long term. Factors focused upon…

  2. Success factors and limitations of efficient internal communication

    Directory of Open Access Journals (Sweden)

    Dariusz Tworzydło

    2015-03-01

    Full Text Available The article covers the key issues of internal communication within an organization. It highlights the benefits of implementation of transparent communication principles for a company. It identifies objectives and presents selected communication tools. In the article, also guidelines for carrying out research in the context of development of an internal communication strategy can be found. Selected research areas of the process of planning and implementation of strategic assumptions have been presented. Factors limiting effective implementation of an internal communication strategy have been discussed.

  3. Population transfer and coherence in the adiabatic limit by counterintuitive and intuitive pulse sequences

    Institute of Scientific and Technical Information of China (English)

    Zhou Yan-Wei; Ye Cun-Yun

    2005-01-01

    Two approaches of achieving population transfer and coherence are investigated for the three-level A system in the adiabatic limit. The effects of the laser pulse sequence on the population transfer efficiency and coherence are studied.Coherent control of quantum state and population is studied by numerical simulation based on self-consistent set of density matrix equations. It can be seen that the counterintuitive pulse sequence is more efficient in population transfer and coherence than the intuitive one.

  4. Periodicity in a "Food-limited" Population Model with Toxicants and Time Delays

    Institute of Scientific and Technical Information of China (English)

    Meng Fan; Ke Wang

    2002-01-01

    With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree, we study the global existence of positive periodic solutions of a "food-limited" population model with toxicants and time delays. Some new results are obtained.

  5. Factors Influencing Food Choice in the Elderly Mauritian Population ...

    African Journals Online (AJOL)

    Factors Influencing Food Choice in the Elderly Mauritian Population. ... in influencing food choices and thus food intake of the elderly people in Mauritius. A cross-sectional nutritional survey was carried out in different regions around the island ...

  6. Methodological problems with population cancer studies: The forgotten confounding factors.

    Science.gov (United States)

    Blaylock, Russell L

    2015-01-01

    Among clinical physicians it is the population study that is considered to be the "gold standard" of medical evidence concerning acceptable treatments. As new information comes to light concerning the many variables and confounding factors that can affect such studies, many older studies lose much of their original impact. While newer population studies take into consideration a far greater number of confounding factors many are still omitted and a number of these omitted factors can have profound effects on interpretation and validity of the study. In this editorial, I will discuss some of the omitted confounding factors and demonstrate how they can alter the interpretation of these papers and their clinical application.

  7. Production of Spirulina biomass: effects of environmental factors and population density

    Energy Technology Data Exchange (ETDEWEB)

    Vonshak, A.; Abeliovich, A.; Boussiba, S.; Arad, S.; Richmond, A.

    1982-07-01

    The effects of environmental conditions (solar irradiance and temperature) and population density on the production of Spirulina biomass are reported for cultures grown in outdoor ponds. Both the specific rate of photosynthesis, expressed on a chlorophyll basis, and rate of respiration, on a protein basis, decreased as algal concentration increased. Higher specific growth rates were observed at lower population densities. Lower growth rates were associated with the light limitation in dense cultures for optimum conditions in the summer. Seasonal variation was observed in productivity. In summer light was the limiting factor whereas in winter the low daytime temperature appeared to impose the major limitation. It was found that the oxygen concentration in the culture can serve as a useful indicator of limiting factors and can also be used as a means of estimating the extent of such limitations. (Refs. 19).

  8. Are populations of neotropical migrant birds limited in summer or winter? implications for management

    Science.gov (United States)

    Thomas W. Sherry; Richard T. Holmes

    1993-01-01

    Understanding where in their annual cycle Neotropical-Nearctic migrant bird populations are limited is essential for developing effective management and conservation policies. A review of currently available information indicates that these long-distance migrant species may be limited by events and circumstances in both summer and winter, and possibly on migration as...

  9. The limits of weak selection and large population size in evolutionary game theory.

    Science.gov (United States)

    Sample, Christine; Allen, Benjamin

    2017-03-28

    Evolutionary game theory is a mathematical approach to studying how social behaviors evolve. In many recent works, evolutionary competition between strategies is modeled as a stochastic process in a finite population. In this context, two limits are both mathematically convenient and biologically relevant: weak selection and large population size. These limits can be combined in different ways, leading to potentially different results. We consider two orderings: the [Formula: see text] limit, in which weak selection is applied before the large population limit, and the [Formula: see text] limit, in which the order is reversed. Formal mathematical definitions of the [Formula: see text] and [Formula: see text] limits are provided. Applying these definitions to the Moran process of evolutionary game theory, we obtain asymptotic expressions for fixation probability and conditions for success in these limits. We find that the asymptotic expressions for fixation probability, and the conditions for a strategy to be favored over a neutral mutation, are different in the [Formula: see text] and [Formula: see text] limits. However, the ordering of limits does not affect the conditions for one strategy to be favored over another.

  10. Psychosocial factors at work and the development of mobility limitations among adults in Denmark

    DEFF Research Database (Denmark)

    Hansen, Åse Marie; Darsø, Lilie; Manty, Minna

    2014-01-01

    : This study is based on data from 2952 middle-aged men and women without mobility limitations in 2000. Results: We found increased risk of incident mobility limitations during 6-year follow up among men who often perceived high work pace (OR 5.45, 95% CI 1.21-24.52) vs. never, who only sometimes or....../never perceived the work to be meaningful (OR 6.54, 95% CI 1.55-27.55) vs. always, and who sometimes perceived high emotional demands at work (OR 7.85, 95% CI 1.78-34.65) vs. never. Among women, lower risk of incident mobility limitations was observed among those who in 2000 perceived high work pace sometimes (OR......Aim: Psychosocial factors in the working environment have been shown to be associated with mobility limitations, but this has not yet been confirmed in a Danish population. We aimed to examine how psychosocial factors at work are related to developing mobility limitations in Denmark. Methods...

  11. Optimal population prediction of sandhill crane recruitment based on climate-mediated habitat limitations.

    Science.gov (United States)

    Gerber, Brian D; Kendall, William L; Hooten, Mevin B; Dubovsky, James A; Drewien, Roderick C

    2015-09-01

    1. Prediction is fundamental to scientific enquiry and application; however, ecologists tend to favour explanatory modelling. We discuss a predictive modelling framework to evaluate ecological hypotheses and to explore novel/unobserved environmental scenarios to assist conservation and management decision-makers. We apply this framework to develop an optimal predictive model for juvenile (<1 year old) sandhill crane Grus canadensis recruitment of the Rocky Mountain Population (RMP). We consider spatial climate predictors motivated by hypotheses of how drought across multiple time-scales and spring/summer weather affects recruitment. 2. Our predictive modelling framework focuses on developing a single model that includes all relevant predictor variables, regardless of collinearity. This model is then optimized for prediction by controlling model complexity using a data-driven approach that marginalizes or removes irrelevant predictors from the model. Specifically, we highlight two approaches of statistical regularization, Bayesian least absolute shrinkage and selection operator (LASSO) and ridge regression. 3. Our optimal predictive Bayesian LASSO and ridge regression models were similar and on average 37% superior in predictive accuracy to an explanatory modelling approach. Our predictive models confirmed a priori hypotheses that drought and cold summers negatively affect juvenile recruitment in the RMP. The effects of long-term drought can be alleviated by short-term wet spring-summer months; however, the alleviation of long-term drought has a much greater positive effect on juvenile recruitment. The number of freezing days and snowpack during the summer months can also negatively affect recruitment, while spring snowpack has a positive effect. 4. Breeding habitat, mediated through climate, is a limiting factor on population growth of sandhill cranes in the RMP, which could become more limiting with a changing climate (i.e. increased drought). These effects are

  12. Macroecological factors explain large-scale spatial population patterns of ancient agriculturalists

    NARCIS (Netherlands)

    Xu, C.; Chen, B.; Abades, S.; Reino, L.; Teng, S.; Ljungqvist, F.C.; Huang, Z.Y.X.; Liu, X.

    2015-01-01

    Aim: It has been well demonstrated that the large-scale distribution patterns of numerous species are driven by similar macroecological factors. However, understanding of this topic remains limited when applied to our own species. Here we take a large-scale look at ancient agriculturalist population

  13. Population impact of familial and environmental risk factors for schizophrenia

    DEFF Research Database (Denmark)

    Sørensen, Holger Jelling; Nielsen, Philip Finn Rising; Pedersen, Carsten B

    2014-01-01

    Although several studies have examined the relative contributions of familial and environmental risk factors for schizophrenia, few have additionally examined the predictive power on the individual level and simultaneously examined the population impact associated with a wide range of familial...... and environmental risk factors. The authors present rate ratios (IRR), population-attributable risks (PAR) and sex-specific cumulative incidences of the following risk factors: parental history of mental illness, urban place of birth, advanced paternal age, parental loss and immigration status. We established...... a population-based cohort of 2,486,646million persons born in Denmark between 1 January 1955 and 31 December 1993 using Danish registers. We found that PAR associated with urban birth was 11.73%; PAR associated with one, respectively 2, parent(s) with schizophrenia was 2.67% and 0.12%. PAR associated...

  14. ANALYSIS OF POPULATION MIGRATION AS A CRIMINOGENIC FACTOR

    Directory of Open Access Journals (Sweden)

    Mariana MITRA-NIŢĂ

    2016-07-01

    Full Text Available Migration is a voluntary movement of population from one geographic location to another. This movement can be of several types, depending on the cause determining the respective migration. Population movements or its mobility is not a new phenomenon but has deep roots in ancient history. We can even say that in the beginning man was migratory, nomadic and later it became steadfast, linked in some way to certain geographic locations. Population migration has multiple consequences, both positive and negative. Among the negative we can mention overpopulation or underpopulation of certain areas, heterogeneity of traditions and cultures of immigrants, inability of migratory population to adapt to the area they migrated to, not finding a job, marginalization, etc. All these are genuine and objective criminological factors that could actually cause committing crimes in the migratory population. We cannot and do not want to stop the mobility of people, but we can be careful to avoid harmful consequences caused by this phenomenon.

  15. Analytical models for well-mixed populations of cooperators and defectors under limiting resources

    CERN Document Server

    Requejo, Rubén J; 10.1103/PhysRevE.85.066112

    2012-01-01

    In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, agent-based models have pointed out that resource limitation may modify the original structure of the interactions and allow for the survival of unconditional cooperators in well-mixed populations. Here, we present analytical simplified versions of two types of agent-based models recently published: one in which the limiting resource constrains the ability of reproduction of individuals but not their survival, and a second one where the limiting resource is necessary for both reproduction and survival. One finds that the analytical models display, with a few differences, the same qualitative behavior of the more complex agent-based models. In addition, the analytical models allow us to expand the study and identify the dimensionless parameters governing the final fate of the system, such as coexistence of cooperators and defectors, or dominance of defectors or of ...

  16. Historical superprocess limits for population models with past dependence and competition

    CERN Document Server

    Méléard, Sylvie

    2011-01-01

    We consider a population structured in trait. When a birth occurs, the trait of the parent is hereditarily transmitted to the offspring unless a mutation occurs. We associate with each individual its lineage consisting of all the traits of his ancestors. The evolution of the population results from the aging, births and deaths of individuals, with a dynamics that may depend on the past history of the lineage and that allows interactions between individuals. We introduce the stochastic process that describes the system and consider its diffusion limit under the assumptions of large populations, individuals of small masses and allometric demographies.

  17. RISK FACTORS ASSOCIATED WITH CARDIOVASCULAR DISEASE IN PRISON POPULATION

    OpenAIRE

    Ricardo Soares de OliveiraI; gor Monteiro Lima Martins; Luís Paulo Souza e Souza; Edna Maria de Souza Oliveira; Jaqueline Teixeira Teles; Jansen Maxwell de Freitas Santana; Antônio Prates Caldeira

    2014-01-01

    This work aimed to make a reflection about the risk factors associated with cardiovascular disease in the prison population, as well as the performance of the health care team in these spaces. It is a reflective approach, literature that included e-journal articles, published in the year 2003 to 2011, indexed at LILACS, Scielo, MEDLINE, and available in full. Textbooks were also consulted and ordinances of Ministry of health and Justice of Brazil. Used the descriptors "risk factors," "cardiov...

  18. Limited Sexual Reproduction and Quick Turnover in the Population Genetic Structure of Phytophthora infestans in Fujian, China.

    Science.gov (United States)

    Zhu, Wen; Yang, Li-Na; Wu, E-Jiao; Qin, Chun-Fang; Shang, Li-Ping; Wang, Zong-Hua; Zhan, Jiasui

    2015-05-13

    The mating system plays an important role in the spatiotemporal dynamics of pathogen populations through both its direct and indirect impact on the generation and distribution of genetic variation. Here, we used a combination of microsatellite and phenotypic markers to investigate the spatiotemporal distribution of genetic variation in Phytophthora infestans isolates collected from Fujian, China and to determine the role of sexual reproduction in the dynamics. Although the pathogen populations in this region were dominated by self-fertile genotypes, sexual reproduction only occurred occasionally and its contributions to the population genetic structure of P. infestans and epidemics of late blight in the region were limited. Only 49 genotypes were detected among the 534 isolates assayed and the pathogen populations displayed significant heterozygosity excess. Hierarchical analysis revealed that 21.42% of genetic variation was attributed to the difference among sampling years while only 4.45% was attributed to the difference among locations, suggesting temporal factors play a more important role in the population genetic dynamics of P. infestans than spatial factors in this region. We propose that clonal reproduction, combined with founder effects and long distance dispersal of sporangia, is responsible for the observed pattern of spatiotemporal dynamics in P. infestans.

  19. Pollen-limited reproduction in blue oak: Implications for wind pollination in fragmented populations

    Science.gov (United States)

    Knapp, E.E.; Goedde, M.A.; Rice, K.J.

    2001-01-01

    Human activities are fragmenting forests and woodlands worldwide, but the impact of reduced tree population densities on pollen transfer in wind-pollinated trees is poorly understood. In a 4-year study, we evaluated relationships among stand density, pollen availability, and seed production in a thinned and fragmented population of blue oak (Quercus douglasii). Geographic coordinates were established and flowering interval determined for 100 contiguous trees. The number of neighboring trees within 60 m that released pollen during each tree's flowering period was calculated and relationships with acorn production explored using multiple regression. We evaluated the effects of female flower production, average temperature, and relative humidity during the pollination period, and number of pollen-producing neighbors on individual trees' acorn production. All factors except temperature were significant in at least one of the years of our study, but the combination of factors influencing acorn production varied among years. In 1996, a year of large acorn crop size, acorn production was significantly positively associated with number of neighboring pollen producers and density of female flowers. In 1997, 1998, and 1999, many trees produced few or no acorns, and significant associations between number of pollen-producing neighbors and acorn production were only apparent among moderately to highly reproductive trees. Acorn production by these reproductive trees in 1997 was significantly positively associated with number of neighboring pollen producers and significantly negatively associated with average relative humidity during the pollination period. In 1998, no analysis was possible, because too few trees produced a moderate to large acorn crop. Only density of female flowers was significantly associated with acorn production of moderately to highly reproductive trees in 1999. The effect of spatial scale was also investigated by conducting analyses with pollen producers

  20. Rapid method of determining factors limiting bacterial growth in soil

    OpenAIRE

    Aldén Demoling, Louise; Demoling, Fredrik; Bååth, Erland

    2001-01-01

    A technique to determine which nutrients limit bacterial growth in soil was developed. The method was based on measuring the thymidine incorporation rate of bacteria after the addition of C, N, and P in different combinations to soil samples. First, the thymidine incorporation method was tested in two different soils: an agricultural soil and a forest humus soil. Carbon (as glucose) was found to be the limiting substance for bacterial growth in both of these soils. The effect of adding differ...

  1. Limit on an Isotropic Diffuse Gamma-Ray Population with HAWC

    CERN Document Server

    ,

    2015-01-01

    Data from 105 days from the High Altitude Water Cherenkov Observatory (HAWC) have been used to place a new limit on an isotropic diffuse gamma-ray population above 10 TeV. High- energy isotropic diffuse gamma-ray emission is produced by unresolved extragalactic objects such as active galactic nuclei, with potential contributions from interactions of high-energy cosmic rays with the inter-Galactic medium, or dark matter annihilation. Isotropic diffuse gamma-ray emission has been observed up to nearly 1 TeV. Above this energy, only upper limits have been reported. Observations or limits of the isotropic photon population above these energies are very sensitive to local astrophysical particle production. Of particular note, we expect a photon population to accompany the TeV-PeV astrophysical neutrino detection seen in the IceCube instrument. Observations or limits of a photon population above this energy can point to the origin of these neutrinos, indicating whether they are within the gamma-ray horizon or not. ...

  2. Stochastic models for structured populations scaling limits and long time behavior

    CERN Document Server

    Meleard, Sylvie

    2015-01-01

    In this contribution, several probabilistic tools to study population dynamics are developed. The focus is on scaling limits of qualitatively different stochastic individual based models and the long time behavior of some classes of limiting processes. Structured population dynamics are modeled by measure-valued processes describing the individual behaviors and taking into account the demographic and mutational parameters, and possible interactions between individuals. Many quantitative parameters appear in these models and several relevant normalizations are considered, leading  to infinite-dimensional deterministic or stochastic large-population approximations. Biologically relevant questions are considered, such as extinction criteria, the effect of large birth events, the impact of  environmental catastrophes, the mutation-selection trade-off, recovery criteria in parasite infections, genealogical properties of a sample of individuals. These notes originated from a lecture series on Structured P...

  3. A multi-scale distribution model for non-equilibrium populations suggests resource limitation in an endangered rodent.

    Directory of Open Access Journals (Sweden)

    William T Bean

    Full Text Available Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define "available" habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining "available" habitat in habitat selection studies, and suggests a way to create distribution models at spatial and

  4. Using Dynamic Stochastic Modelling to Estimate Population Risk Factors in Infectious Disease: The Example of FIV in 15 Cat Populations

    OpenAIRE

    David Fouchet; Guillaume Leblanc; Frank Sauvage; Micheline Guiserix; Hervé Poulet; Dominique Pontier

    2009-01-01

    BACKGROUND: In natural cat populations, Feline Immunodeficiency Virus (FIV) is transmitted through bites between individuals. Factors such as the density of cats within the population or the sex-ratio can have potentially strong effects on the frequency of fight between individuals and hence appear as important population risk factors for FIV. METHODOLOGY/PRINCIPAL FINDINGS: To study such population risk factors, we present data on FIV prevalence in 15 cat populations in northeastern France. ...

  5. Limiter

    Science.gov (United States)

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  6. An application of MCMC simulation in mortality projection for populations with limited data

    Directory of Open Access Journals (Sweden)

    Jackie Li

    2014-01-01

    Full Text Available Objective: IIn this paper, we investigate the use of Bayesian modeling and Markov chain Monte Carlo (MCMC simulation, via the software WinBUGS, to project future mortality for populations with limited data. In particular, we adapt some extensions of the Lee-Carter method under the Bayesian framework to allow for situations in which mortality data are scarce. Our approach would be useful for certain developing nations that have not been regularly collecting death counts and population statistics. Inferences of the model estimates and forecasts can readily be drawn from the simulated samples. Information on another population resembling the population under study can be exploited and incorporated into the prior distributions in order to facilitate the construction of probability intervals. The two sets of data can also be modeled in a joint manner. We demonstrate an application of this approach to some data from China and Taiwan.

  7. Limiting factors of exercise performance 1 year after lung transplantation

    NARCIS (Netherlands)

    Reinsma, G. D.; ten Hacken, N. H. T.; Grevink, R. G.; van der Bij, W.; Koer, G. H.; van Weert, E.

    2006-01-01

    Background: After lung transplantation (LTx). exercise capacity frequently remains limited, despite significantly improved pulmonary function. The aim of this study was to evaluate maximal exercise capacity and peripheral muscle force before and 1 year after LTx, and to determine whether peripheral

  8. Effect of Drought on Herbivore-Induced Plant Gene Expression: Population Comparison for Range Limit Inferences

    Directory of Open Access Journals (Sweden)

    Gunbharpur Singh Gill

    2016-03-01

    Full Text Available Low elevation “trailing edge” range margin populations typically face increases in both abiotic and biotic stressors that may contribute to range limit development. We hypothesize that selection may act on ABA and JA signaling pathways for more stable expression needed for range expansion, but that antagonistic crosstalk prevents their simultaneous co-option. To test this hypothesis, we compared high and low elevation populations of Boechera stricta that have diverged with respect to constitutive levels of glucosinolate defenses and root:shoot ratios; neither population has high levels of both traits. If constraints imposed by antagonistic signaling underlie this divergence, one would predict that high constitutive levels of traits would coincide with lower plasticity. To test this prediction, we compared the genetically diverged populations in a double challenge drought-herbivory growth chamber experiment. Although a glucosinolate defense response to the generalist insect herbivore Spodoptera exigua was attenuated under drought conditions, the plastic defense response did not differ significantly between populations. Similarly, although several potential drought tolerance traits were measured, only stomatal aperture behavior, as measured by carbon isotope ratios, was less plastic as predicted in the high elevation population. However, RNAseq results on a small subset of plants indicated differential expression of relevant genes between populations as predicted. We suggest that the ambiguity in our results stems from a weaker link between the pathways and the functional traits compared to transcripts.

  9. Plant defences limit herbivore population growth by changing predator-prey interactions.

    Science.gov (United States)

    Kersch-Becker, Mônica F; Kessler, André; Thaler, Jennifer S

    2017-09-13

    Plant quality and predators are important factors affecting herbivore population growth, but how they interact to regulate herbivore populations is not well understood. We manipulated jasmonate-induced plant resistance, exposure to the natural predator community and herbivore density to test how these factors jointly and independently affect herbivore population growth. On low-resistance plants, the predator community was diverse and abundant, promoting high predator consumption rates. On high-resistance plants, the predator community was less diverse and abundant, resulting in low predator consumption rate. Plant resistance only directly regulated aphid population growth on predator-excluded plants. When predators were present, plant resistance indirectly regulated herbivore population growth by changing the impact of predators on the herbivorous prey. A possible mechanism for the interaction between plant resistance and predation is that methyl salicylate, a herbivore-induced plant volatile attractive to predators, was more strongly induced in low-resistance plants. Increased plant resistance reduced predator attractant lures, preventing predators from locating their prey. Low-resistance plants may regulate herbivore populations via predators by providing reliable information on prey availability and increasing the effectiveness of predators. © 2017 The Author(s).

  10. Factors affecting minority population proximity to hazardous facilities

    Energy Technology Data Exchange (ETDEWEB)

    Nieves, L.A. [Argonne National Lab., IL (United States); Nieves, A.L. [Wheaton Coll., IL (United States)]|[Argonne National Lab., IL (United States)

    1995-04-01

    Disproportionate exposure of minority groups to environmental hazards has been attributed to ``environmental racism`` by some authors, without systematic investigation of the factors underlying this exposure pattern. This study examines regional differences in the proximity of African-Americans, Hispanics, Asians, and non-Hispanic Whites to a broad range of facility types and explores the effects of urban and income factors. A statistically significant inverse relationship is found between the percentage of non-Hispanic Whites and virtually all facility categories in all regions. Except for Hispanics in the South, all such associations for minority groups show a direct relationship, though some are nonsignificant. The geographic concentration of facilities is more closely tied to urbanization than to economic factors. Controlling for both urban and economic factors, minority population concentration is still a significant explanatory variable for some facility types in some regions. This finding is most consistent for African-Americans.

  11. Population policy of local self-government: Necessities possibilities and limitation

    Directory of Open Access Journals (Sweden)

    Gavrilović Ana

    2006-01-01

    Full Text Available Taking into consideration the roles it objectively has, the state is also responsible for the formulation and implementation of population policy. In the process of its articulation, population policy of our state, although not explicitly formulated, continual and consistent, went through various phases of development, but was mostly in the shadow of other policies. In order to be successful, population policy has to be local, too. The need for definition and implementation of local population policy is indicated by insufficiency and inefficiency of government measures, knowledge of determinants of reproductive behavior and social processes, especially society democratization and globalization. The possibilities available are not sufficiently used. The attention is focused on the measures of material assistance, which is understandable in present conditions, while the measures of non-material assistance are almost missing. The paper is pointing out the non-material potentials and the necessity of their activation. The paper also contains the results of an empiric research carried out by interviewing the presidents of the population policy committees within municipal assemblies in the Autonomous Province of Vojvodina, thus providing the picture of the present situation, and knowledge of their positions, opinions and suggestions for the better use of potentials and overcoming of limitations in population policy.

  12. The course of physical functional limitations and occupational conditions in a middle-aged working population in France

    Directory of Open Access Journals (Sweden)

    de Stampa Matthieu

    2012-04-01

    Full Text Available Abstract Background Physical functional limitations (PFL have mainly been studied in older populations. The aim of this study was to better understand the course of PFL and associations with occupational factors by gender in a middle-aged working population. Methods The data came from 16,950 workers in the ESTEV (Enquête Santé Travail et Vieillissement cohort in France. PFL were assessed using the physical abilities section of the Nottingham Health Profile. Occupational conditions were measured with a self-administered questionnaire covering physical and psychosocial factors in 1990 and 1995. Multivariate analyses were used to assess the associations. Results The PFL appearance rate in 1995 was the same by gender (6.3%; the rate of PFL recovery was higher in men (23.9% versus 20.9%. Age was an independent factor of PFL at age 47 years or older in both genders after adjusting for confounding factors. The PFL appearance rate in 1995 was higher with physical occupational exposure in 1990, such as awkward work with a dose relation in both genders, while the PFL recovery rate decreased significantly only for men. Exposure to psychosocial occupational conditions, such as having the means to produce quality work in 1990, was significantly associated with a decreased PFL appearance rate in 1995 in both genders, and having high decision latitude in 1990 was associated with a decreased PFL appearance rate in 1995 only in men. Changes in exposure to occupational factors between 1990 and 1995 were associated with the PFL appearance and recovery rates in 1995 in both genders. Conclusions After five years, the course of PFL in this working population changed and was associated with physical and psychosocial occupational factors. Relationships were stronger for the PFL appearance rate in both genders and were weaker for recovery from PFL, mainly among women.

  13. Six Sigma: Problems, Limitations, Critical Success Factors and Future Prospects

    Directory of Open Access Journals (Sweden)

    Paulo Mazieiro Pohlmann

    2015-12-01

    Full Text Available Six Sigma is a business strategy based on objective decision making and problem solving in order to achieve, maintain and maximize business success through understanding and meeting the needs of customers. The visualization of this methodology as a powerful tool in reducing variability and improving quality led to the interest in performing this bibliographical study, whose purpose was to assess the critical success factors and future prospects of this managerial system. A survey was conducted in order to discover the main critical success factors of the implementation of the methodology in organizations, among which stood out the proper selection of projects, connecting the project with the business strategy, customer focus, financial, human and infrastructure resources, the involvement of senior management, professional training, and cultural change.

  14. Modifiable Cardiovascular Disease Risk Factors among Indigenous Populations

    Directory of Open Access Journals (Sweden)

    Adam A. Lucero

    2014-01-01

    Full Text Available Objective. To identify modifiable cardio-metabolic and lifestyle risk factors among indigenous populations from Australia (Aboriginal Australians/Torres Strait Islanders, New Zealand (Māori, and the United States (American Indians and Alaska Natives that contribute to cardiovascular disease (CVD. Methods. National health surveys were identified where available. Electronic databases identified sources for filling missing data. The most relevant data were identified, organized, and synthesized. Results. Compared to their non-indigenous counterparts, indigenous populations exhibit lower life expectancies and a greater prevalence of CVD. All indigenous populations have higher rates of obesity and diabetes, hypertension is greater for Māori and Aboriginal Australians, and high cholesterol is greater only among American Indians/Alaska Natives. In turn, all indigenous groups exhibit higher rates of smoking and dangerous alcohol behaviour as well as consuming less fruits and vegetables. Aboriginal Australians and American Indians/Alaska Natives also exhibit greater rates of sedentary behaviour. Conclusion. Indigenous groups from Australia, New Zealand, and the United States have a lower life expectancy then their respective non-indigenous counterparts. A higher prevalence of CVD is a major driving force behind this discrepancy. A cluster of modifiable cardio-metabolic risk factors precede CVD, which, in turn, is linked to modifiable lifestyle risk factors.

  15. Existence of limit cycles in the Solow model with delayed-logistic population growth.

    Science.gov (United States)

    Bianca, Carlo; Guerrini, Luca

    2014-01-01

    This paper is devoted to the existence and stability analysis of limit cycles in a delayed mathematical model for the economy growth. Specifically the Solow model is further improved by inserting the time delay into the logistic population growth rate. Moreover, by choosing the time delay as a bifurcation parameter, we prove that the system loses its stability and a Hopf bifurcation occurs when time delay passes through critical values. Finally, numerical simulations are carried out for supporting the analytical results.

  16. Memory and self-induced shocks in an evolutionary population competing for limited resources.

    Science.gov (United States)

    Kay, Roland; Johnson, Neil F

    2004-11-01

    We present a detailed discussion of the role played by memory, and the nature of self-induced shocks, in an evolutionary population competing for limited resources. Our study builds on a previously introduced multiagent system [Phys. Rev. Lett. 82, 3360 (1999)] which has attracted significant attention in the literature. This system exhibits self-segregation of the population based on the "gene" value p (where 0resource level, and self-induced large changes which spontaneously arise as the dynamical system evolves. We find that the large, macroscopic self-induced shocks that arise are controlled by microscopic changes within extreme subgroups of the population (i.e., subgroups with "gene" values p approximately 0 and p approximately 1).

  17. Evolution of Wheat streak mosaic virus: dynamics of population growth within plants may explain limited variation.

    Science.gov (United States)

    French, Roy; Stenger, Drake C

    2003-01-01

    Like many other plant RNA viruses, Wheat streak mosaic virus (WSMV) sequence diversity within and among infected plants is low given the large number of virions produced. This may be explained by considering aspects of plant virus life history. Intracellular replication of RNA viruses is predominately linear, not exponential, which means that the rate at which mutations accumulate also is linear. Bottlenecks during systemic movement further limit diversity. Analysis of mixed infections with two WSMV isolates suggests that about four viral genomes participate in systemic invasion of each tiller. Low effective population size increases the role of stochastic processes on dynamics of plant virus population genetics and evolution. Despite low pair-wise diversity among isolates, the number of polymorphic sites within the U.S. population is about the same as between divergent strains or a sister species. Characteristics of polymorphism in the WSMV coat protein gene suggest that most variation appears neutral.

  18. The effect of food limitation on immunity factors and disease resistance in the western tent caterpillar.

    Science.gov (United States)

    Myers, Judith H; Cory, Jenny S; Ericsson, Jerry D; Tseng, Michelle L

    2011-11-01

    Epizootics of nucleopolyhedrovirus characterize declines of cyclic populations of western tent caterpillars, Malacosoma pluviale californicum. In field populations, infection can be apparently lacking in one generation and high in the next. This may suggest an increase in the susceptibility to infection of larvae at peak density or the triggering of a vertically transmitted virus. Here, we test the hypothesis that reduced food availability, as may occur during population outbreaks of tent caterpillars, influences the immunocompetence of larvae and increases their susceptibility to viral infection. We compared immunity factors, hemolymph phenoloxidase and hemocyte numbers, and the susceptibility to nucleopolyhedroviral infection of fifth instar larvae that were fully or partially fed as fourth instars. To determine if maternal or transgenerational influences occurred, we also determined the susceptibility of the offspring of the treated parents to viral infection. Food limitation significantly reduced larval survival, development rate, larval and pupal mass, moth fecundity and levels of hemolymph phenoloxidase, but not the numbers of hemocytes. Neither the food-reduced larvae nor their offspring were more susceptible to viral infection and were possibly even less susceptible at intermediate viral doses. Food reduction did not activate latent or covert viral infection of larvae as might be expected as a response to stress. We conclude that reducing the food intake of fourth instar larvae to an extent that had measurable and realistic impacts on their life history characteristics was not translated into increased susceptibility to viral infection.

  19. Biodiversities and limiting factors of Lashgardar Protected Area (LPA, Hamadan Province, Iran

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    MAHDI REYAHI KHORAM

    2010-10-01

    Full Text Available Reyahi-Khoram M, Norisharikabad V (2011 Biodiversities and limiting factors of Lashgardar Protected Area (LPA, Hamadan Province, Iran. Biodiversitas 12: 216-221. Lashgardar Protected Area (LPA located in Hamadan Province in Iran, it is a mountainous and plain area and proximal to Malayer Township. In 1991, the region was known as a protected area for increasing wild animals' population. This research has been conducted during 2001 through 2009. Plant and animal species of the region were identified and statistics of the population of animal flagship species were gathered. In this research, valid academic resources were used for identification of animal and plant species. Geographic Information System (GIS has been used to evaluate the land as main tool. The software used was Arc View (version 3.2a scale was 1/50,000. Due to cold mountainous climate, the region is covered by a wide diversity of trees, shrubs, grasses and herbs. There were 18 species of mammals as well as 75 bird species in LPA. Most abundant mammalian population belongs to wild sheep (558 animals and the second abundance was related to wild goat (515 animals. Also, the most abundant bird species belong to ortolans. Result of the present study showed that construction of connection roads in vicinity the region, establishment of factories inside and around the region, military garrison, unauthorized grazing, unlawful hunting, and Ahangaran mine and rail road have all exposed put LPA to serious threat and danger.

  20. Environmental factors limiting fertilisation and larval success in corals

    Science.gov (United States)

    Woods, Rachael M.; Baird, Andrew H.; Mizerek, Toni L.; Madin, Joshua S.

    2016-12-01

    Events in the early life history of reef-building corals, including fertilisation and larval survival, are susceptible to changes in the chemical and physical properties of sea water. Quantifying how changes in water quality affect these events is therefore important for understanding and predicting population establishment in novel and changing environments. A review of the literature identified that levels of salinity, temperature, pH, suspended sediment, nutrients and heavy metals affect coral early life-history stages to various degrees. In this study, we combined published experimental data to determine the relative importance of sea water properties for coral fertilisation success and larval survivorship. Of the water properties manipulated in experiments, fertilisation success was most sensitive to suspended sediment, copper, salinity, phosphate and ammonium. Larval survivorship was sensitive to copper, lead and salinity. A combined model was developed that estimated the joint probability of both fertilisation and larval survivorship in sea water with different chemical and physical properties. We demonstrated the combined model using water samples from Sydney and Lizard Island in Australia to estimate the likelihood of larvae surviving through both stages of development to settlement competency. Our combined model could be used to recommend targets for water quality in coastal waterways as well as to predict the potential for species to expand their geographical ranges in response to climate change.

  1. Nightmares: risk factors among the Finnish general adult population.

    Science.gov (United States)

    Sandman, Nils; Valli, Katja; Kronholm, Erkki; Revonsuo, Antti; Laatikainen, Tiina; Paunio, Tiina

    2015-04-01

    To identify risk factors for experiencing nightmares among the Finnish general adult population. The study aimed to both test whether previously reported correlates of frequent nightmares could be reproduced in a large population sample and to explore previously unreported associations. Two independent cross-sectional population surveys of the National FINRISK Study. Age- and sex-stratified random samples of the Finnish population in 2007 and 2012. A total of 13,922 participants (6,515 men and 7,407 women) aged 25-74 y. N/A. Nightmare frequency as well as several items related to socioeconomic status, sleep, mental well-being, life satisfaction, alcohol use, medication, and physical well-being were recorded with a questionnaire. In multinomial logistic regression analysis, a depression-related negative attitude toward the self (odds ratio [OR] 1.32 per 1-point increase), insomnia (OR 6.90), and exhaustion and fatigue (OR 6.86) were the strongest risk factors for experiencing frequent nightmares (P < 0.001 for all). Sex, age, a self-reported impaired ability to work, low life satisfaction, the use of antidepressants or hypnotics, and frequent heavy use of alcohol were also strongly associated with frequent nightmares (P < 0.001 for all). Symptoms of depression and insomnia were the strongest predictors of frequent nightmares in this dataset. Additionally, a wide variety of factors related to psychological and physical well-being were associated with nightmare frequency with modest effect sizes. Hence, nightmare frequency appears to have a strong connection with sleep and mood problems, but is also associated with a variety of measures of psychological and physical well-being. © 2015 Associated Professional Sleep Societies, LLC.

  2. Analytical models for well-mixed populations of cooperators and defectors under limiting resources

    Science.gov (United States)

    Requejo, R. J.; Camacho, J.

    2012-06-01

    In the study of the evolution of cooperation, resource limitations are usually assumed just to provide a finite population size. Recently, however, agent-based models have pointed out that resource limitation may modify the original structure of the interactions and allow for the survival of unconditional cooperators in well-mixed populations. Here, we present analytical simplified versions of two types of agent-based models recently published: one in which the limiting resource constrains the ability of reproduction of individuals but not their survival, and a second one where the limiting resource is necessary for both reproduction and survival. One finds that the analytical models display, with a few differences, the same qualitative behavior of the more complex agent-based models. In addition, the analytical models allow us to expand the study and identify the dimensionless parameters governing the final fate of the system, such as coexistence of cooperators and defectors, or dominance of defectors or of cooperators. We provide a detailed analysis of the occurring phase transitions as these parameters are varied.

  3. Explanatory factors of female entrepreneurship and limiting elements

    Directory of Open Access Journals (Sweden)

    Carmina Pérez-Pérez

    2016-06-01

    Full Text Available Researches on entrepreneurship from a gender perspective reveal significant differences not only between the levels of participation of men and women in business, but also between the orientations, motives and business opportunities for both. Based on this fact, the following investigation is performed, whose objective is twofold: firstly, to know what are the aspects that influence the entrepreneurship of women and secondly, to identify what factors determine and/or difficult the creation and development of business that they undertake. To achieve both, it is reviewed, first, the literature on this subject and, second, are exposed the main results of the qualitative analysis with Atlas.ti from interviews with a group of Spanish entrepreneurs.

  4. Phosphorus as a limiting factor on sustainable greywater irrigation.

    Science.gov (United States)

    Turner, Ryan D R; Will, Geoffrey D; Dawes, Les A; Gardner, Edward A; Lyons, David J

    2013-07-01

    Water reuse through greywater irrigation has been adopted worldwide and has been proposed as a potential sustainable solution to increased water demands. Despite widespread adoption, there is limited domestic knowledge of greywater reuse. There is no pressure to produce low-level phosphorus products and current guidelines and legislation, such as those in Australia, may be inadequate due to the lack of long-term data to provide a sound scientific basis. Research has clearly identified phosphorus as a potential environmental risk to waterways from many forms of irrigation. To assess the sustainability of greywater irrigation, this study compared four residential lots that had been irrigated with greywater for four years and adjacent non-irrigated lots that acted as controls. Each lot was monitored for the volume of greywater applied and selected physic-chemical water quality parameters and soil chemistry profiles were analysed. The non-irrigated soil profiles showed low levels of phosphorus and were used as controls. The Mechlich3 Phosphorus ratio (M3PSR) and Phosphate Environmental Risk Index (PERI) were used to determine the environmental risk of phosphorus leaching from the irrigated soils. Soil phosphorus concentrations were compared to theoretical greywater irrigation loadings. The measured phosphorus soil concentrations and the estimated greywater loadings were of similar magnitude. Sustainable greywater reuse is possible; however incorrect use and/or lack of understanding of how household products affect greywater can result in phosphorus posing a significant risk to the environment.

  5. Factors limiting deceased organ donation: focus groups' perspective from culturally diverse community.

    Science.gov (United States)

    Wong, L P

    2010-06-01

    In-depth understanding of cultural and religious factors limiting organ donation of three ethnic populations (Malay, Chinese, and Indian) in Southeast Asia is lacking. Identification of factors limiting organ donation among these three ethnic groups will provide insights into culturally appropriate strategies to promote acceptance of organ donation in a multiethnic Asian community. A total of 17 focus group discussions (105 participants) were conducted between September and December 2008. Participants were members of the general public aged 18 to 60 years, recruited through convenient sampling around the Klang Valley area of Malaysia. Although the majority had favorable attitudes toward deceased organ donation and transplantation, a diversity of myths and misinformation were unearthed from the discussions across the ethnic groups. These include perceived religious prohibition, cultural myths and misperceptions, fear of disfigurement, fear of surgery, distrust of the medical system, and family disapproval. Culture and religious beliefs played important prohibitive roles among those opposed to organ donations. There were distinctive ethnic differences in cultural and religious concerns regarding organ donation. Less-educated and rural groups appeared to have more misconceptions than the well-educated and the urban groups. Our findings may assist organ donation and transplantation organizations to reach diverse sociodemographic and ethnic communities with culture-specific information about organ donation. The involvement of community and religious leaders is critical in organ donation requests.

  6. Factors Associated with Chronic Noncancer Pain in the Canadian Population

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    Saifudin Rashiq

    2009-01-01

    Full Text Available Chronic noncancer pain (CNCP is a prevalent health problem with pervasive negative effects on the individual’s quality of life. Previous epidemiological studies of CNCP have suggested a number of individual biological, psychological and societal correlates of CNCP, but it has rarely been possible to simultaneously compare the relative strengths of many such correlates in a Canadian population sample. With data provided by the 1996/1997 Canadian National Population Health Survey, ordinal logistic regression was used to examine the extent to which a number of population variables are associated with CNCP in a large (n=69,365 dataset. The analysis revealed cross-sectional correlations of varying strengths between CNCP and 27 factors. Increasing age, low income, low educational achievement, daily cigarette smoking, physical inactivity and abstention from alcohol were among the factors found to increase CNCP risk. The considerable impact of distress and depression on CNCP are also highlighted. A number of comorbid medical illnesses increased CNCP risk, including some (such as chronic obstructive pulmonary disease, epilepsy and thyroid disease that have not hitherto been associated with pain. White race and the affirmation of an important role for spirituality or faith reduced CNCP risk. In contrast to some previous studies, female sex did not emerge as an independent CNCP risk. The present exploratory analysis describes associations between CNCP and a number of characteristics from several domains, thus suggesting many areas for further research.

  7. Efficiency limit factor analysis for the Francis-99 hydraulic turbine

    Science.gov (United States)

    Zeng, Y.; Zhang, L. X.; Guo, J. P.; Guo, Y. K.; Pan, Q. L.; Qian, J.

    2017-01-01

    The energy loss in hydraulic turbine is the most direct factor that affects the efficiency of the hydraulic turbine. Based on the analysis theory of inner energy loss of hydraulic turbine, combining the measurement data of the Francis-99, this paper calculates characteristic parameters of inner energy loss of the hydraulic turbine, and establishes the calculation model of the hydraulic turbine power. Taken the start-up test conditions given by Francis-99 as case, characteristics of the inner energy of the hydraulic turbine in transient and transformation law are researched. Further, analyzing mechanical friction in hydraulic turbine, we think that main ingredients of mechanical friction loss is the rotation friction loss between rotating runner and water body, and defined as the inner mechanical friction loss. The calculation method of the inner mechanical friction loss is given roughly. Our purpose is that explore and research the method and way increasing transformation efficiency of water flow by means of analysis energy losses in hydraulic turbine.

  8. The use of population viability analysis to identify possible factors contributing to the decline of a rare ungulate population in south-eastern Zimbabwe

    Directory of Open Access Journals (Sweden)

    Simon D. Capon

    2013-04-01

    Full Text Available Populations that are vulnerable to decline are of particular concern to wildlife managers and uncovering the mechanisms responsible for downward trends is a crucial step towards developing future viable populations. The aims of this study were to better understand the mechanisms behind the historic decline of the sable antelope, Hippotragus niger, population at the Malilangwe Wildlife Reserve (MWR, to assess its future viability and to use this analysis to determine key areas of breakdown in population growth and link these to potential limiting factors. VORTEX, a population viability model was used to assess the future viability of the sable antelope population and a sensitivity analysis was applied to identify the key areas of breakdown in growth. The sable population is currently viable, but remains highly vulnerable to changes in adult female survival, a factor which had the greatest influence on overall population fitness. Lion predation, impacting on the adult segment of the population, appeared to be the main factor responsible for the historic decline at the MWR.Conservation implications: Sable generally occur at low densities in the lowveld region of Zimbabwe and, as such, populations are vulnerable to increases in mortality rates. The role of lions in driving the decline at the MWR suggests a need to control their numbers and develop prey refuges through improved management of artificial water.

  9. Risk factors for primary liver carcinoma in Chinese population

    Institute of Scientific and Technical Information of China (English)

    Rui-Hong Luo; Zhi-Xin Zhao; Xu-Yu Zhou; Zhi-Liang Gao; Ji-Lu Yao

    2005-01-01

    AIM: To evaluate the risk factors for primary liver carcinoma (PLC) in Chinese population.METHODS: Chinese Biomedical Literature Database,China Hospital Knowledge Database and MEDLINE were searched. All the related literatures were screened, and the risk factors for PLC in Chinese population were studied.Heterogeneity was evaluated by odds ratio (OR) q test.Combined OR and its 95% confidence interval (95%CI)were calculated, the association between the investigated risk factors and PLC was determined. Validity and bias of the findings were evaluated by sensitivity analysis and funnel plot analysis respectively.RESULTS: Fifty-five of one hundred and ninety identified studies were accepted according to the inclusive criteria.Ten factors related to PLC were demonstrated by sensitive analysis and funnel plot analysis. They were cirrhosis (OR = 11.97, P= 0.000), HBV infection (OR = 11.34, P= 0.000),HCV infection (OR = 4.28, P = 0.000), family history of liver cancer (OR = 3.49, P = 0.000), unstable emotion (OR = 2.20, P = 0.000), depressed characters (OR = 3.07,P = 0.000), aflatoxin (OR = 1.80, P = 0.000), alcoholic (OR = 1.88, P = 0.000), intake of musty food (OR = 1.87,P = 0.000) and drinking contaminated water from pond (OR = 1.77, P= 0.003).CONCLUSION: The main risk factors for PLC in China are liver diseases, family history of liver carcinoma, poor psychic status, afiatoxin, and some unhealthy behaviors.

  10. GOLD criteria overestimate airflow limitation in one-third of cases in the general Finnish population

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    Annette Kainu

    2016-10-01

    Full Text Available The Global Initiative for Chronic Obstructive Lung Disease (GOLD diagnostic criteria for chronic obstructive pulmonary disease (COPD use a fixed threshold of forced expiratory volume in 1 s (FEV1/forced vital capacity (FVC ratio (<0.70 in post-bronchodilation spirometry to indicate disease, which has been shown to underestimate and overestimate disease prevalence in younger and older adults, respectively, whilst criteria based on reference values have better accuracy. Differences in reference values have limited their use in international studies. However, the new Global Lung Function Initiative reference values (GLI2012 showed FEV1/FVC to be the least dependent on ethnicity. The aim of this study was to assess the prevalence of airflow limitation with GLI2012 and the degree of underdetection or overestimation related to the use of GOLD in the general population. A Finnish population sample of 1323 subjects (45% male with post-bronchodilation spirometry was studied. 80 subjects (6.0% and 55 subjects (4.2% were identified with airflow limitation with GOLD and GLI2012 criteria, respectively. The proportion of overestimation with GOLD increased with age from 25% of cases in 50-year-olds to 54% in 70-year-olds. Using z-score-based grading resulted in more dispersion in severity grading. In conclusion, the GOLD criteria cause a marked overestimation already from 50-year-olds and should be replaced with the GLI2012 criteria to improve diagnostic accuracy.

  11. Iodine distribution in the environment as a limiting factor for roe deer antler development.

    Science.gov (United States)

    Lehoczki, Róbert; Erdélyi, Károly; Sonkoly, Krisztina; Szemethy, László; Csányi, Sándor

    2011-02-01

    The iodine-containing hormones produced by the thyroid gland play a role in the complex neuro-hormonal regulation of antler development. The proper function of the thyroid depends on the adequate iodine supply of the organism, which is directly related to the iodine content of food and drinking water. The purpose of this study was to explore the connection between the iodine content of the water base, which has a strong correlation with the iodine concentration of environmental components available to animals, and the antler weight of roe deer (Capreolus capreolus) shot in Hungarian hunting areas. Using a general linear model, controlling for the collective effects of other environmental factors (deer population density, harvest rate, land use, and soil fertility information), the iodine content of the water base explained 51.4% of the total variance of antler weights. The results suggest that antler weights increase with increasing iodine concentration regardless of other factors; thus, the environmental iodine distribution can be a limiting factor suppressing roe deer performance assessed here as antler weight. Further experimental studies of controlled iodine uptake are needed to define the exact physiological iodine requirements of roe deer bucks.

  12. Association of cardiovascular burden with mobility limitation among elderly people: a population-based study.

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    Anna-Karin Welmer

    Full Text Available BACKGROUND: Cardiovascular risk factors (CRFs such as smoking and diabetes have been associated with mobility limitations among older adults. We seek to examine to what extent individual and aggregated CRFs and cardiovascular diseases (CVDs are associated with mobility limitation. METHODS: The study sample included 2725 participants (age ≥60 years, mean age 72.7 years, 62% women in the Swedish National Study on Aging and Care in the Kungsholmen district of central Stockholm, Sweden, who were living either at their own home or in institutions. Data on demographic features, CRFs, and CVDs were collected through interview, clinical examination, self-reported history, laboratory tests, and inpatient register. Mobility limitation was defined as walking speed <0.8 m/s. Data were analyzed using multiple logistic models controlling for potential confounders. RESULTS: Of the 2725 participants, 581 (21.3% had mobility limitation. The likelihood of mobility limitation increased linearly with the increasing number of CRFs (i.e., hypertension, high C-reactive protein, obesity, diabetes and smoking (p for linear trend<0.010 and of CVDs (i.e., ischemic heart disease, atrial fibrillation, heart failure and stroke (p for linear trend<0.001. There were statistical interactions of aggregated CRFs with age and APOE ε4 allele on mobility limitation (p interaction<0.05, such that the association of mobility limitation with aggregated CRFs was statistically evident only among people aged <80 years and among carriers of the APOE ε4 allele. CONCLUSION: Aggregations of multiple CRFs and CVDs are associated with an increased likelihood of mobility limitation among older adults; however the associations of CRFs with mobility limitation vary by age and genetic susceptibility.

  13. Environmental and societal influences acting on cardiovascular risk factors and disease at a population level: a review.

    Science.gov (United States)

    Chow, Clara Kayei; Lock, Karen; Teo, Koon; Subramanian, S V; McKee, Martin; Yusuf, Salim

    2009-12-01

    It has long been known that cardiovascular disease (CVD) rates vary considerably among populations, across space and through time. It is now apparent that most of the attributable risk for myocardial infarction 'within' populations from across the world can be ascribed to the varying levels of a limited number of risk factors among individuals in a population. Individual risk factors (e.g. blood pressure) can be modified with resulting health gains. Yet, the persistence of large international variations in cardiovascular risk factors and resulting CVD incidence and mortality indicates that there are additional factors that apply to 'populations' that are important to understand as part of a comprehensive approach to CVD control. This article reviews the evidence on why certain populations are more at risk than others.

  14. Does gall midge larvae cause pre-dispersal seed mortality and limit cornflower population growth?

    Science.gov (United States)

    Koprdova, Stanislava; Bellanger, Solène; Skuhrovec, Jiří; Darmency, Henri

    2015-11-01

    Many kinds of pests can reduce seed production. Some directly attack seeds before they are released, and some are hosted by the fruit and impact seed ripening and viability indirectly. Pre-dispersal seed mortality may have strong effects on plant population dynamics and evolution. Our goals were to determine to what extent insect-mediated pre-dispersal seed mortality contributes to population-level declines of cornflower, Centaurea cyanus L. We recorded occurrence and abundance of seed-feeding insects on flower heads in twelve cornflower populations. We measured flower head size, number of disc florets, seed production, and seed viability and germination. Larger flower heads had proportionally fewer healthy seeds. Although we observed no visible damage to the C. cyanus seed, the presence of gall midge (Cecidomyiidae) larvae inside the flower head correlated with four times fewer viable seeds. It seems that gall midges could have a significant impact on ovule fertilization, seed abortion and viability of fully developed cornflower seeds. The higher rate of aborted seeds in the presence of gall midge larvae could have been because the larvae extracted resources from the seeds, or because the larvae repelled pollinators. The viability of apparently healthy seeds was 40% lower in flower heads that contained larvae and/or aborted seed. Insect-mediated pre-dispersal mortality could select against evolution toward larger flower head, and have detrimental consequences on seed number, viability and germination, all of which could limit the spread of C. cyanus populations.

  15. App Usage Factor: A Simple Metric to Compare the Population Impact of Mobile Medical Apps.

    Science.gov (United States)

    Lewis, Thomas Lorchan; Wyatt, Jeremy C

    2015-08-19

    One factor when assessing the quality of mobile apps is quantifying the impact of a given app on a population. There is currently no metric which can be used to compare the population impact of a mobile app across different health care disciplines. The objective of this study is to create a novel metric to characterize the impact of a mobile app on a population. We developed the simple novel metric, app usage factor (AUF), defined as the logarithm of the product of the number of active users of a mobile app with the median number of daily uses of the app. The behavior of this metric was modeled using simulated modeling in Python, a general-purpose programming language. Three simulations were conducted to explore the temporal and numerical stability of our metric and a simulated app ecosystem model using a simulated dataset of 20,000 apps. Simulations confirmed the metric was stable between predicted usage limits and remained stable at extremes of these limits. Analysis of a simulated dataset of 20,000 apps calculated an average value for the app usage factor of 4.90 (SD 0.78). A temporal simulation showed that the metric remained stable over time and suitable limits for its use were identified. A key component when assessing app risk and potential harm is understanding the potential population impact of each mobile app. Our metric has many potential uses for a wide range of stakeholders in the app ecosystem, including users, regulators, developers, and health care professionals. Furthermore, this metric forms part of the overall estimate of risk and potential for harm or benefit posed by a mobile medical app. We identify the merits and limitations of this metric, as well as potential avenues for future validation and research.

  16. Food as a limiting factor for Aedes aegypti in water-storage containers.

    Science.gov (United States)

    Arrivillaga, Jazzmin; Barrera, Roberto

    2004-06-01

    An understanding of the ecological factors that regulate natural populations of Aedes aegypti mosquitoes can improve control and reduce the incidence of dengue (DF) and dengue hemorrhagic fever (DHF) in tropical areas. We investigated whether immature Ae. aegypti in water-storage containers from an urban area were under food limitation. We used starvation resistance (number of days alive without food) as an indicator of the feeding history in third-instar Ae. aegypti larvae. Resistance to starvation and other measures of immature success, such as development time, survival, and adult mass, were investigated across a wide range of feeding conditions in the laboratory. Resistance to starvation of third-instar larvae and body mass of adults emerging from pupae collected in water-storage containers in an urban area were compared with the laboratory results. If resistance to starvation and adult mass of field-collected Ae. aegypti corresponded with the lower levels of feeding in the laboratory, then food limitation could be inferred in field-collected larvae. Results showed that resistance to starvation was well correlated with previous feeding levels and with the other measures of immature success. Both resistance to starvation and adult body mass of field-collected specimens corresponded with the lower levels of feeding in the laboratory. Therefore, it was concluded that food limitation or competition is likely to be a regulatory factor in water-storage containers in the urban area. It is recommended that any control measure applied to immature Ae. aegypti in water-storage containers should eliminate all or most of the individuals, otherwise unintended, undesirable results might occur, such as the production of more and larger adults.

  17. Nutrient deifciency limits population development, yield formation, and nutrient uptake of direct sown winter oilseed rape

    Institute of Scientific and Technical Information of China (English)

    WANG Yin; LIU Tao; LI Xiao-kun; REN Tao; CONG Ri-huan; LU Jian-wei

    2015-01-01

    Direct-sowing establishment method has great signiifcance in improving winter oilseed rape (Brassica napus L.) production and guaranteeing edible oil security in China. However, nutrient responses on direct sown winter oilseed rape (DOR) performance and population development dynamic are stil not wel understood. Therefore, ifve on-farm experiments were conducted in the reaches of the Yangtze River (RYR) to determine the effects of nitrogen (N), phosphorus (P), and potassium (K) deifciencies on population density, dry matter production, nutrient uptake, seed yield, and yield components of DOR plants. Four fertilization treatments included the balanced NPK application treatment (NPK, 180 kg N, 39.3 kg P, 100 kg K, and 1.8 kg borax ha–1) and three nutrient deifciency treatments based on the NPK treatment, i.e.,–N,–P, and–K. The results indicated that DOR population density declined gradual y throughout the growing season, especial y at over-wintering and pod-development stages. Nutrient deifciency decreased nutrient concentration in DOR plants, limited dry matter production and nutrient uptake, and thereby exacerbated density reduction during plants growth. The poor individual growth and reduced population density together decreased seed yield in the nutrient deifciency treatment. Averaged across al the experiments, seed yield reduced 61% by N deifciency, 38.3% by P deifciency, and 14.4% by K deifciency. The negative effects of nutrient deifciency on DOR performances fol owed the order of–N>–P>–K, and the effects were various among different nutrient deifciencies. Although N deifciency improved DOR emergence, but it seriously limited dry matter production and nutrient uptake, which in turn led to substantial plants death and therefore resulted in a very low harvested density. The P deifciency signiifcantly reduced initial density, limited plants growth, and exacerbated density reduction. The K deifciency mainly decreased individual growth and yield, but

  18. Habitat-mediated population limitation in a colonial central-place forager: the sky is not the limit for the black-browed albatross.

    Science.gov (United States)

    Wakefield, Ewan D; Phillips, Richard A; Matthiopoulos, Jason

    2014-03-07

    Animal populations are frequently limited by the availability of food or of habitat. In central-place foragers, the cost of accessing these resources is distance-dependent rather than uniform in space. However, in seabirds, a widely studied exemplar of this paradigm, empirical population models have hitherto ignored this cost. In part, this is because non-independence among colonies makes it difficult to define population units. Here, we model the effects of both resource availability and accessibility on populations of a wide-ranging, pelagic seabird, the black-browed albatross Thalassarche melanophris. Adopting a multi-scale approach, we define regional populations objectively as spatial clusters of colonies. We consider two readily quantifiable proxies of resource availability: the extent of neritic waters (the preferred foraging habitat) and net primary production (NPP). We show that the size of regional albatross populations has a strong dependence, after weighting for accessibility, on habitat availability and to a lesser extent, NPP. Our results provide indirect support for the hypothesis that seabird populations are regulated from the bottom-up by food availability during the breeding season, and also suggest that the spatio-temporal predictability of food may be limiting. Moreover, we demonstrate a straightforward, widely applicable method for estimating resource limitation in populations of central-place foragers.

  19. Population Estimates of School Age Language Minorities and Limited English Proficiency Children of the United States, 1979-1988.

    Science.gov (United States)

    Chapa, Jorge

    Estimates of the school-age, 5-17-year-old, language minority and Limited-English-Proficient (LEP) populations in the United States are discussed. The estimates are based on the population counts for first, second, and third generation Hispanics, Anglos, Asians, and Blacks derived from the June 1988 Current Population Survey. The language minority…

  20. RISK FACTORS ASSOCIATED WITH CARDIOVASCULAR DISEASE IN PRISON POPULATION

    Directory of Open Access Journals (Sweden)

    Ricardo Soares de OliveiraI

    2014-02-01

    Full Text Available This work aimed to make a reflection about the risk factors associated with cardiovascular disease in the prison population, as well as the performance of the health care team in these spaces. It is a reflective approach, literature that included e-journal articles, published in the year 2003 to 2011, indexed at LILACS, Scielo, MEDLINE, and available in full. Textbooks were also consulted and ordinances of Ministry of health and Justice of Brazil. Used the descriptors "risk factors," "cardiovascular disease" and "Prisoners". It was noted that the current situation of overcrowding in prisons is, with unhealthy environment, which imposes risks the health of prisoners. The living habits, such as use of alcohol and drugs (cocaine, marijuana, tranquillizers and tobacco, increases the risk for cardiovascular disease. In addition, the authors emphasize, a priori, the low level of schooling of the detainees. The performance of the health care team must be based on educational practices for promoting and monitoring the health, with multidisciplinary support. Further studies need to be done in order to investigate the incidence of cardiovascular diseases, as well as evidence of the effectiveness of health care for this population.

  1. Socio-demographic factors related to functional limitations and care dependency among older Egyptians

    NARCIS (Netherlands)

    Boggatz, Thomas; Farid, Tamer; Mohammedin, Ahmed; Dijkstra, Ate; Lohrmann, Christa; Dassen, Theo

    P>Title. Socio-demographic factors related to functional limitations and care dependency among older Egyptians. Aim. This paper is a report of a study determining the relationship of socio-demographic factors to functional limitations and care dependency among older care recipients and non-care

  2. Socio-demographic factors related to functional limitations and care dependency among older Egyptians

    NARCIS (Netherlands)

    Boggatz, Thomas; Farid, Tamer; Mohammedin, Ahmed; Dijkstra, Ate; Lohrmann, Christa; Dassen, Theo

    2010-01-01

    P>Title. Socio-demographic factors related to functional limitations and care dependency among older Egyptians. Aim. This paper is a report of a study determining the relationship of socio-demographic factors to functional limitations and care dependency among older care recipients and non-care reci

  3. Development of management quality system for metallurgical enterprise based on Balanced Scorecard with limiting factors

    Directory of Open Access Journals (Sweden)

    Galina Ledneva

    2009-12-01

    Full Text Available The article considers inefficiency of the existing quality management systems (QMS based on standards ISO series 9000. The authors offer integrated QMS with limiting factors on Balanced Scorecard. The Balanced Scorecard with limiting factors helps to efficiently direct process of continuous improvement and achieve top-priority criteria in quality management domain.

  4. Genetic and environmental factors influencing the Placental Growth Factor (PGF) variation in two populations

    DEFF Research Database (Denmark)

    Sorice, Rossella; Ruggiero, Daniela; Nutile, Teresa

    2012-01-01

    . However, to date, no information is available regarding the genetics of PGF variability. Furthermore, even though the effect of environmental factors (e.g.: cigarette smoking) on angiogenesis has been explored, no data on the influence of these factors on PGF levels have been reported so far. Here we have...... first investigated PGF variability in two cohorts focusing on non-genetic risk factors: a study sample from two isolated villages in the Cilento region, South Italy (N=871) and a replication sample from the general Danish population (N=1,812). A significant difference in PGF mean levels was found...... between the two cohorts. However, in both samples, we observed a strong correlation of PGF levels with ageing and sex, men displaying PGF levels significantly higher than women. Interestingly, smoking was also found to influence the trait in the two populations, although differently. We have then focused...

  5. Limited Pollen Dispersal Contributes to Population Genetic Structure but Not Local Adaptation in Quercus oleoides Forests of Costa Rica.

    Directory of Open Access Journals (Sweden)

    Nicholas John Deacon

    Full Text Available Quercus oleoides Cham. and Schlect., tropical live oak, is a species of conservation importance in its southern range limit of northwestern Costa Rica. It occurs in high-density stands across a fragmented landscape spanning a contrasting elevation and precipitation gradient. We examined genetic diversity and spatial genetic structure in this geographically isolated and genetically distinct population. We characterized population genetic diversity at 11 nuclear microsatellite loci in 260 individuals from 13 sites. We monitored flowering time at 10 sites, and characterized the local environment in order to compare observed spatial genetic structure to hypotheses of isolation-by-distance and isolation-by-environment. Finally, we quantified pollen dispersal distances and tested for local adaptation through a reciprocal transplant experiment in order to experimentally address these hypotheses.High genetic diversity is maintained in the population and the genetic variation is significantly structured among sampled sites. We identified 5 distinct genetic clusters and average pollen dispersal predominately occurred over short distances. Differences among sites in flowering phenology and environmental factors, however, were not strictly associated with genetic differentiation. Growth and survival of upland and lowland progeny in their native and foreign environments was expected to exhibit evidence of local adaptation due to the more extreme dry season in the lowlands. Seedlings planted in the lowland garden experienced much higher mortality than seedlings in the upland garden, but we did not identify evidence for local adaptation.Overall, this study indicates that the Costa Rican Q. oleoides population has a rich population genetic history. Despite environmental heterogeneity and habitat fragmentation, isolation-by-distance and isolation-by-environment alone do not explain spatial genetic structure. These results add to studies of genetic structure by

  6. Colic in a working horse population in Egypt: Prevalence and risk factors.

    Science.gov (United States)

    Salem, S E; Scantlebury, C E; Ezzat, E; Abdelaal, A M; Archer, D C

    2017-03-01

    Colic is an important health problem in managed horse populations. Currently, there is limited information about colic prevalence and risk factors for colic in working horse populations. To determine the prevalence of, and risk factors for, colic in a working horse population in Egypt and to describe management practices in this working horse population. Cross-sectional survey. Owners of 350 working horses were interviewed. Data about their horses, management and colic episodes in the preceding 12 months were collected. Dental examination was conducted on 342 horses and blood samples (n = 100) were collected for immunodiagnosis of tapeworm (Anoplocephala perfoliata) infection. Multivariable logistic regression analysis was used to identify risk factors for a history of colic in the preceding 12 months. The 12-month prevalence of colic was 54.6%. Severe and moderate tapeworm infection intensity was identified in 3% and 26% of horses tested, respectively. Horses that had severe dental disease (odds ratio [OR] 6.8, 95% confidence interval [CI] 1.9-24.3, Phistory of colic in the preceding 12 months. Horses fed on rice bran during the 'green season' (OR 0.47, 95% CI 0.26-0.9, P = 0.015) and that displayed geophagia/coprophagia (OR 0.19, 95% CI 0.05-0.73, P = 0.001) were less likely to have a history of colic. Colic is common in this working horse population and this study has identified factors associated with altered likelihood of colic. The study provides important information that may be used to inform future prospective studies investigating colic in working horse populations and to assist development of preventive healthcare strategies. The Summary is available in Chinese - see Supporting information. © 2016 EVJ Ltd.

  7. Trends in population blood pressure and determinant factors for population blood pressure.

    Science.gov (United States)

    Andersen, Ulla Overgaard

    2017-03-01

    Strategies to reduce the burden of blood pressure attributable diseases require knowledge of secular trend in PBP and its determinants. The issues were investigated in the Copenhagen City Heart Study. The design of CCHS is a repeated measures study. Such designs are uniquely suited to studying changes of an outcome and what risk factors may be associated with that outcome. Repeated measures studies are very well suited for trend analysis by using mixed effect analyses. SBP decreased about 2 mmHg in 25 years. The risk factors age, gender and BMI were found valid as determinant factors for secular trends in SBP. In addition, the following factors were identified: household income and the interactions ''gender*age'' and ''survey*age''. The interaction ''gender*age'' stated that the difference between SBP in the two genders was great in the young individuals and diminished by age. The interaction ''survey*age'' stated that SBP in the young individuals decreased more with survey than SBP in the older individuals. Thus, the 20 years old subjects in survey 2, 3 and 4 have lower SBP than the 20 years old subjects in preceding surveys. The slopes were less steep in higher ages. In the group of elderly and old subjects the trend is partly explained by treatment bias because more and more subjects leave the untreated group and start treatment. The factor ''household income'' was significant only in the female population and stated that high-income women had lower SBP and a more beneficial secular trend in SBP than low-income women. Marital status, self-reported physical exercise and alcohol intake were not significant factors. A number of factors, that are interesting in relation to SBP, were not included in the CCHS and therefore not investigated. Among them are salt intake, childhood factors, genetic factors and the DASH diet. A survival study was performed to investigate the mortality rate in relation to SBP changes during the observation period. A Cox regression analysis

  8. Impact of Environmental Factors on Legionella Populations in Drinking Water

    Directory of Open Access Journals (Sweden)

    David Otto Schwake

    2015-05-01

    Full Text Available To examine the impact of environmental factors on Legionella in drinking water distribution systems, the growth and survival of Legionella under various conditions was studied. When incubated in tap water at 4 °C, 25 °C, and 32 °C, L. pneumophila survival trends varied amongst the temperatures, with the stable populations maintained for months at 25 °C and 32 °C demonstrating that survival is possible at these temperatures for extended periods in oligotrophic conditions. After inoculating coupons of PVC, copper, brass, and cast iron, L. pneumophila colonized biofilms formed on each within days to a similar extent, with the exception of cast iron, which contained 1-log less Legionella after 90 days. L. pneumophila spiked in a model drinking water distribution system colonized the system within days. Chlorination of the system had a greater effect on biofilm-associated Legionella concentrations, with populations returning to pre-chlorination levels within six weeks. Biofilms sampled from drinking water meters collected from two areas within central Arizona were analyzed via PCR for the presence of Legionella. Occurrence in only one area indicates that environmental differences in water distribution systems may have an impact on the survival of Legionella. These results document the impact of different environmental conditions on the survival of Legionella in water.

  9. On the Role of the $\\Omega\\Gamma$ Limit in the Formation of Population III Massive Stars

    CERN Document Server

    Lee, Hunchul

    2016-01-01

    We explore the role of the modified Eddington limit due to rapid rotation (the so-called $\\Omega\\Gamma-$limit) in the formation of Population III stars. We performed one-dimensional stellar evolution simulations of mass-accreting zero-metallicity protostars at a very high rate ($\\dot{M} \\sim 10^{-3}~\\mathrm{M_\\odot~yr^{-1}}$) and dealt with stellar rotation as a separate post-process. The protostar would reach the Keplerian rotation very soon after the onset of mass accretion, but mass accretion would continue as stellar angular momentum is transferred outward to the accretion disk by viscous stress. The protostar envelope expands rapidly when the stellar mass reaches $5\\sim7~\\mathrm{M_\\odot}$ and the Eddington factor sharply increases. This makes the protostar rotate critically at a rate that is significantly below the Keplerian value (i.e., the $\\Omega\\Gamma-$limit). The resultant positive gradient of the angluar velocity in the boundary layer between the protostar and the Keplerian disk prohibits angular m...

  10. Chaos and order in stateless societies: Intercommunity exchange as a factor impacting the population dynamical patterns

    Energy Technology Data Exchange (ETDEWEB)

    Medvinsky, Alexander B., E-mail: medvinsky@iteb.ru [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Moscow Region (Russian Federation); Rusakov, Alexey V. [Institute of Theoretical and Experimental Biophysics, Russian Academy of Sciences, Pushchino 142290, Moscow Region (Russian Federation)

    2011-06-15

    Highlights: > We model community dynamics in stateless societies. > Intercommunity barter is shown to be a factor impacting the societies dynamics. > Increase in the human population growth rate can lead to appearance of chaos. > Secular and millennial cycles are found to arise as a result of the barter. - Abstract: The once abstract notions of dynamical chaos now appear naturally in various systems [Kaplan D, Glass L. Understanding nonlinear dynamics. New York: Springer; 1995]. As a result, future trajectories of the systems may be difficult to predict. In this paper, we demonstrate the appearance of chaotic dynamics in model human communities, which consist of producers of agricultural product and producers of agricultural equipment. In the case of a solitary community, the horizon of predictability of the human population dynamics is shown to be dependent on both intrinsic instability of the dynamics and the chaotic attractor sizes. Since a separate community is usually a part of a larger commonality, we study the dynamics of social systems consisting of two interacting communities. We show that intercommunity barter can lead to stabilization of the dynamics in one of the communities, which implies persistence of stable equilibrium under changes of the maximum value of the human population growth rate. However, in the neighboring community, the equilibrium turns into a stable limit cycle as the maximum value of the human population growth rate increases. Following an increase in the maximum value of the human population growth rate leads to period-doubling bifurcations resulting in chaotic dynamics. The horizon of predictability of the chaotic oscillations is found to be limited by 5 years. We demonstrate that the intercommunity interaction can lead to the appearance of long-period harmonics in the chaotic time series. The period of the harmonics is of order 100 and 1000 years. Hence the long-period changes in the population size may be considered as an

  11. Population Bottlenecks Increase Additive Genetic Variance But Do Not Break a Selection Limit in Rainforest Drosophila

    DEFF Research Database (Denmark)

    van Heerwaarden, Belinda; Willi, Yvonne; Kristensen, Torsten N

    2008-01-01

    actually increase additive genetic variance. This has been an important issue in conservation genetics where it has been suggested that small population size might actually experience an increase rather than a decrease in the rate of adaptation. Here we test if bottlenecks can break a selection limit...... for desiccation resistance in the rain forest-restricted fly Drosophila bunnanda. After one generation of single-pair mating, additive genetic variance for desiccation resistance increased to a significant level, on average higher than for the control lines. Line crosses revealed that both dominance and epistatic...... effects were responsible for the divergence in desiccation resistance between the original control and a bottlenecked line exhibiting increased additive genetic variance for desiccation resistance. However, when bottlenecked lines were selected for increased desiccation resistance, there was only a small...

  12. Slow and fast scales for superprocess limits of age-structured populations

    CERN Document Server

    Méléard, Sylvie

    2010-01-01

    A superprocess limit for an interacting birth-death particle system modelling a population with trait and age-structures is established. Traits of newborn offspring are inherited from the parents except when mutations occur, while ages are set to zero. Because of interactions between individuals, standard approaches based on the Laplace transform do not hold. We use a martingale problem approach and a separation of the slow (trait) and fast (age) scales. While the trait marginals converge in a pathwise sense to a superprocess, the age dynamics, on another time scale, averages to an equilibrium that depends on traits. The convergence of the whole process depending on trait and age, only holds for finite-dimensional time-marginals. We apply our results to the study of examples illustrating different cases of trade-off between competition and senescence.

  13. Present limits to heat-adaptability in corals and population-level responses to climate extremes.

    Directory of Open Access Journals (Sweden)

    Bernhard M Riegl

    Full Text Available Climate change scenarios suggest an increase in tropical ocean temperature by 1-3°C by 2099, potentially killing many coral reefs. But Arabian/Persian Gulf corals already exist in this future thermal environment predicted for most tropical reefs and survived severe bleaching in 2010, one of the hottest years on record. Exposure to 33-35°C was on average twice as long as in non-bleaching years. Gulf corals bleached after exposure to temperatures above 34°C for a total of 8 weeks of which 3 weeks were above 35°C. This is more heat than any other corals can survive, providing an insight into the present limits of holobiont adaptation. We show that average temperatures as well as heat-waves in the Gulf have been increasing, that coral population levels will fluctuate strongly, and reef-building capability will be compromised. This, in combination with ocean acidification and significant local threats posed by rampant coastal development puts even these most heat-adapted corals at risk. WWF considers the Gulf ecoregion as "critically endangered". We argue here that Gulf corals should be considered for assisted migration to the tropical Indo-Pacific. This would have the double benefit of avoiding local extinction of the world's most heat-adapted holobionts while at the same time introducing their genetic information to populations naïve to such extremes, potentially assisting their survival. Thus, the heat-adaptation acquired by Gulf corals over 6 k, could benefit tropical Indo-Pacific corals who have <100 y until they will experience a similarly harsh climate. Population models suggest that the heat-adapted corals could become dominant on tropical reefs within ∼20 years.

  14. Upper limits on the mass and luminosity of Population III-dominated galaxies

    CERN Document Server

    Yajima, Hidenobu

    2016-01-01

    We here derive upper limits on the mass and luminosity of Population III (POPIII) dominated proto-galaxies based on the collapse of primordial gas under the effect of angular momentum loss via Ly$\\alpha$ radiation drag and the gas accretion onto a galactic centre. Our model predicts that POPIII-dominated galaxies at z ~ 7 are hosted by haloes with $M_{\\rm halo} \\sim 1.5 \\times 10^{8} - 1.1 \\times 10^{9} \\rm ~M_{\\odot}$, that they have Ly$\\alpha$ luminosities of $L_{\\rm Ly\\alpha} \\sim 3.0 \\times 10^{42} - 2.1 \\times 10^{43}$ erg/s, stellar mass of $M_{\\rm star} \\sim 0.8 \\times 10^{5} - 2.5 \\times 10^{6} \\rm ~M_{\\odot}$, and outflowing gas with velocities $V_{\\rm out} \\sim 40$ km/s due to Ly$\\alpha$ radiation pressure. We show that the POPIII galaxy candidate CR7 violates the derived limits on stellar mass and Ly$\\alpha$ luminosity and thus is unlikely to be a POPIII galaxy. POPIII-dominated galaxies at z ~ 7 have HeII line emission that is ~1- 3 orders of magnitude lower then that of Ly$\\alpha$, they have high...

  15. Upper limits on the mass and luminosity of Population III-dominated galaxies

    Science.gov (United States)

    Yajima, Hidenobu; Khochfar, Sadegh

    2017-05-01

    We here derive upper limits on the mass and luminosity of Population III (POPIII) dominated proto-galaxies based on the collapse of primordial gas under the effect of angular momentum loss via Lyα radiation drag and the gas accretion on to a galactic centre. Our model predicts that POPIII-dominated galaxies at z ˜ 7 are hosted by haloes with Mh ˜ 1.5 × 108-1.1 × 109 M⊙, that they have Lyα luminosities of LLyα ˜ 3.0 × 1042-2.1 × 1043 erg s- 1, stellar mass of Mstar ˜ 0.8 × 105-2.5 × 106 M⊙ and outflowing gas with velocities Vout ˜ 40 km s- 1 due to Lyα radiation pressure. We show that the POPIII galaxy candidate CR7 violates the derived limits on stellar mass and Lyα luminosity and thus is unlikely to be a POPIII galaxy. POPIII-dominated galaxies at z ˜ 7 have He ii line emission that is ˜1-3 orders of magnitude lower than that of Lyα, they have high Lyα equivalent width of ≳ 300 Å and should be found close to bright star-forming galaxies. The He ii 1640 Å line is in comfortable reach of next generation telescopes, like the James Webb Space Telescope (JWST) or Thirty Meter Telescope (TMT).

  16. Gametogenesis of an intertidal population of Mytilus trossulus in NW Greenland: not a limitation for potential Arctic range expansion

    DEFF Research Database (Denmark)

    Thyrring, Jakob; Jensen, Kurt Thomas; Sejr, Mikael Kristian

    2017-01-01

    The drivers determining species’ northern distribution limits remain elusive and, combined with inadequate knowledge of past and current distribution ranges, this prevents accurate determination of potential changes in the Arctic. The northernmost population of the bivalve Mytilus trossulus...

  17. Multiple factors affect a population of Agassiz's desert tortoise (Gopherus agassizii) in the Northwestern Mojave Desert

    Science.gov (United States)

    Berry, Kristin H.; Yee, Julie L.; Coble, Ashley A.; Perry, William M.; Shields, Timothy A.

    2013-01-01

    Numerous factors have contributed to declines in populations of the federally threatened Agassiz's Desert Tortoise (Gopherus agassizii) and continue to limit recovery. In 2010, we surveyed a low-density population on a military test facility in the northwestern Mojave Desert of California, USA, to evaluate population status and identify potential factors contributing to distribution and low densities. Estimated densities of live tortoises ranged spatially from 1.2/km2 to 15.1/km2. Although only one death of a breeding-age tortoise was recorded for the 4-yr period prior to the survey, remains of 16 juvenile and immature tortoises were found, and most showed signs of predation by Common Ravens (Corvus corax) and mammals. Predation may have limited recruitment of young tortoises into the adult size classes. To evaluate the relative importance of different types of impacts to tortoises, we developed predictive models for spatially explicit densities of tortoise sign and live tortoises using topography (i.e., slope), predators (Common Raven, signs of mammalian predators), and anthropogenic impacts (distances from paved road and denuded areas, density of ordnance fragments) as covariates. Models suggest that densities of tortoise sign increased with slope and signs of mammalian predators and decreased with Common Ravens, while also varying based on interaction effects involving these predictors as well as distances from paved roads, denuded areas, and ordnance. Similarly, densities of live tortoises varied by interaction effects among distances to denuded areas and paved roads, density of ordnance fragments, and slope. Thus multiple factors predict the densities and distribution of this population.

  18. Demographics and limiting factors of tundra nesting birds at the Canning River products

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Products resulting from the Arctic NWR project "Demographics and limiting factors of tundra nesting birds at the Canning River" (PRIMR survey FF07RARC00-010).

  19. Adjective checklist to assess the big five personality factors in the Argentine population.

    Science.gov (United States)

    Ledesma, Rubén D; Sánchez, Roberto; Díaz-Lázaro, Carlos M

    2011-01-01

    The aim of this work was to develop an adjective checklist to assess the Big Five personality factors in the Argentine population. The new instrument was administered to pilot (n= 112), validation (n= 372), and replication (n= 309) samples. The final version of the checklist included 67 adjectives encompassing its 5 dimensions. Factor analysis results were consistent with the Five-factor model. Internal consistency of scales was very good and convergent correlations with the Big Five Inventory (BFI; John, Donahue, & Kentle, 1991) were substantial. Face validity, as evaluated by 2 independent raters, was good. Preliminary evidence of validity for the checklist is presented. Finally, the Adjective Checklist for Personality Assessment and BFI are compared, taking into consideration their psychometric properties in our cultural context. Study limitations and future research are discussed.

  20. [Determining Factors in the Access to Mental Health Services by the Adult Colombian Population].

    Science.gov (United States)

    González, Lina María; Peñaloza, Rolando Enrique; Matallana, María Alexandra; Gil, Fabián; Gómez-Restrepo, Carlos; Landaeta, Angela Patricia Vega

    2016-12-01

    Access to mental health services by people with mental disorders has traditionally been limited, and is associated with attitudinal, social, and structural variables. To analyse the factors that determine access to mental health services by the adult population (18-44 years old) in Colombia, from the results obtained in the 2015 National Mental Health Survey. Analysis of variables of access to attention in mental health care for adults. The reasons for not consulting were classified as barriers of behavioural supply and demand. To analyse the factors associated with access to mental health services in the Colombian adult population, the use of health services in the last 12 months for emotional, nervous or mental health problems was taken into account, as well as associated variables such as demographic characteristics, occupational activity, affiliation to social security, and health status variables. The relationships between these variables were estimated using bivariate multinomial logistic regression models. Rural residence, being married, and having a chronic disease were associated with the decision to consult or not to consult the doctor. Further studies should be conducted to evaluate the situation as regards mental health care access, as well as to determine the potential factors associated with these limitations. Copyright © 2016 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  1. Landslide trigger factors on populated, unstable slopes, Tusion, Tajikistan.

    Science.gov (United States)

    Domej, Gisela

    2015-04-01

    The Pamir region close to the Tajik-Afghan border is regularly affected by severe landslides threatening local population, their livelihood and infrastructure. In addition to landslides appearing as immediate consequence of earthquake, a high number of ground movements without previous seismic activity are also observed. The number of reported events and problem areas has strongly increased within the last ten to fifteen years. Consequently, a study was conducted to determine the triggering factors of these landslides without seismic cause. For accessibility reasons, the community of Tusion, southeast of Khorog, Gorno-Badakhshan, southern Tajikistan, where the capital township is located on a slowly moving slope, was chosen for the pilot project, and geologic mapping as well as seismic refraction and Schlumberger geoelectrics were applied. The geologic survey showed that the valley flanks around Tusion are covered with large amounts of postglacial and fluvial debris as well as moraine deposits. The absence of glacial ice and the retreat of remaining glaciers caused unstable valley flanks at many sites and, in consequence, extensive gravitational mass movements in the past, which are responsible for the today's layered ground structure as well as many secondary slumps. The latter often damage irrigation lines, which tends to further destabilize the slope. To obtain an accurate image of the superposed layers, the geophysical survey was conducted on three inhabited flanks. Arguments in favour for those three locations were not only the possibility of direct risk estimation for the region, but also the fact that the number of landslides increases constantly with population growth. Seismic and electric methods were applied in parallel to distinguish soil types and structural properties as well as to estimate the degree of water saturation. Despite of the methods' simplicity, they revealed precise explanations on triggering factors of landslides. The geophysical survey

  2. Genetic and environmental factors influencing the Placental Growth Factor (PGF variation in two populations.

    Directory of Open Access Journals (Sweden)

    Rossella Sorice

    Full Text Available Placental Growth Factor (PGF is a key molecule in angiogenesis. Several studies have revealed an important role of PGF primarily in pathological conditions (e.g.: ischaemia, tumour formation, cardiovascular diseases and inflammatory processes suggesting its use as a potential therapeutic agent. However, to date, no information is available regarding the genetics of PGF variability. Furthermore, even though the effect of environmental factors (e.g.: cigarette smoking on angiogenesis has been explored, no data on the influence of these factors on PGF levels have been reported so far. Here we have first investigated PGF variability in two cohorts focusing on non-genetic risk factors: a study sample from two isolated villages in the Cilento region, South Italy (N=871 and a replication sample from the general Danish population (N=1,812. A significant difference in PGF mean levels was found between the two cohorts. However, in both samples, we observed a strong correlation of PGF levels with ageing and sex, men displaying PGF levels significantly higher than women. Interestingly, smoking was also found to influence the trait in the two populations, although differently. We have then focused on genetic risk factors. The association between five single nucleotide polymorphisms (SNPs located in the PGF gene and the plasma levels of the protein was investigated. Two polymorphisms (rs11850328 and rs2268614 were associated with the PGF plasma levels in the Cilento sample and these associations were strongly replicated in the Danish sample. These results, for the first time, support the hypothesis of the presence of genetic and environmental factors influencing PGF plasma variability.

  3. Environmental factors related to multiple sclerosis in Indian population.

    Directory of Open Access Journals (Sweden)

    Chaithra Malli

    Full Text Available Multiple sclerosis (MS is less prevalent among Indians when compared to white populations. Genetic susceptibility remaining the same it is possible that environmental associations may have a role in determining disease prevalence.To determine whether childhood infections, vaccination status, past infection with Helicobacter pylori (H.pylori, diet, socioeconomic and educational status were associated with MS.139 patients and 278 matched control subjects were selected. A validated environmental exposure questionnaire was administered. Estimation of serum H.pylori IgG antibody was done by ELISA. Patients and controls were genotyped for HLA-DRB1*15:01.In our cohort a significant association was seen with measles (p < 0.007, vegetarian diet (p < 0.001, higher educational status (p < 0.0001 and urban living (p < 0.0001. An inverse relationship was seen with H.Pylori infection and MS (p < 0.001. Measles infection (OR 6.479, CI 1.21-34.668, p < 0.029 and high educational status (OR 3.088, CI 1.212-7.872, p < 0.018 were significant risk factors associated with MS. H.pylori infection was inversely related to MS (OR 0. 319, CI 0.144- 0.706, p < 0.005.Environmental influences may be important in determining MS prevalence.

  4. Design Factors Affect User Experience for Different Cultural Populations

    Science.gov (United States)

    Chu, Sauman

    2016-01-01

    With increasing changes in our demographic populations and new immigrants settling in the US, there is an increasing need for visual communications that address the diversity of our populations. This paper draws from the results of the researcher's several past research and teaching projects that worked with different cultural populations. These…

  5. Effects of population based screening for Chlamydia infections in the Netherlands limited by declining participation rates.

    Directory of Open Access Journals (Sweden)

    Boris V Schmid

    Full Text Available BACKGROUND: A large trial to investigate the effectiveness of population based screening for chlamydia infections was conducted in the Netherlands in 2008-2012. The trial was register based and consisted of four rounds of screening of women and men in the age groups 16-29 years in three regions in the Netherlands. Data were collected on participation rates and positivity rates per round. A modeling study was conducted to project screening effects for various screening strategies into the future. METHODS AND FINDINGS: We used a stochastic network simulation model incorporating partnership formation and dissolution, aging and a sexual life course perspective. Trends in baseline rates of chlamydia testing and treatment were used to describe the epidemiological situation before the start of the screening program. Data on participation rates was used to describe screening uptake in rural and urban areas. Simulations were used to project the effectiveness of screening on chlamydia prevalence for a time period of 10 years. In addition, we tested alternative screening strategies, such as including only women, targeting different age groups, and biennial screening. Screening reduced prevalence by about 1% in the first two screening rounds and leveled off after that. Extrapolating observed participation rates into the future indicated very low participation in the long run. Alternative strategies only marginally changed the effectiveness of screening. Higher participation rates as originally foreseen in the program would have succeeded in reducing chlamydia prevalence to very low levels in the long run. CONCLUSIONS: Decreasing participation rates over time profoundly impact the effectiveness of population based screening for chlamydia infections. Using data from several consecutive rounds of screening in a simulation model enabled us to assess the future effectiveness of screening on prevalence. If participation rates cannot be kept at a sufficient level

  6. Large population survey: strengths and limits. Methodology of the EDIFICE survey.

    Science.gov (United States)

    Roussel, Claire; Touboul, Chantal

    2011-01-01

    In France, mass screening for breast and colon cancer issupported by the French National Cancer Institute (INCa). In these nationwide screening campaigns, individuals aged between 50 and 74 years receive a personalized letter inviting them for a screening examination every 2 years. Prostate cancer screening is, however, still controversial and has not been included in the INCa recommendations so far. Research organizations are particularly interested in screening and indeed, several studies have been conducted in France and other countries to examine the different aspects of the subject. To provide actual benefits, screening should be undertaken on a regular scheduled basis. Therefore, several studies have assessed the factors influencing the participation rate of women in breast cancer screening in France (). The Institut National de Prévention et d'Education pour la Santé conducted one of these in 2005: the Baromètre Cancer (including 4046 individuals aged 15 years or older, interviewed by telephone) analysed beliefs and perceptions about cancer screening and studied attendance rates for breast, colon and prostate cancer (including scheduled screening). No previous survey has ever been conducted simultaneously among the general population and physicians with regard to individual and scheduled screening for breast cancer and colorectal cancer (CRC) or individual screening for prostate cancer. EDIFICE is thus the first large-scale survey to assess screening practices in France by analysing the targeted population on the one hand and the clinical practice of French general practitioners (GPs) on the other hand, using the 'mirror study' method to compare results. Two national surveys were conducted in 2005 and 2008. In 2005, only 22 geographical regions were included in the screening programme for CRC.

  7. Platelets in the paediatric population: the influence of age and the limitations of automation.

    Science.gov (United States)

    Felle, P; McMahon, C; Rooney, S; Donnelly, P; Ni Chonchubhair, F

    2005-08-01

    Accurate and precise platelet counting is important for the clinical management of children with platelet disorders. Current automated technologies are often unable to discriminate platelets from non-platelet particles particularly in circumstances where platelet anisocytosis is common. This study compares manual methodology and the automated technologies; impedance, optical density and CD61 immunoplatelet method (available on the Cell Dyn 4000) with the reference method of flow cytometric analysis in a paediatric population. A total of 141 samples were analysed and divided into specific age related groups and groups with thrombocytopenia and thrombocytosis. Data analysis showed that the CD61 method compared best with the reference method and this was evident in all the specified groups. The mean platelet count obtained by optical and manual methods were lower, suggesting that these methods are less reliable. The impedance count method was accurate despite its limitations. Strong correlations were observed in the 2-14 year age group but there was greater variation in the platelet characteristics in neonates. The CD61 method is the automated method of choice and would be particularly useful in the problem groups (platelet counts <50 x 10(9)/l and neonates <1 month old).

  8. Risk factors for FEV1 decline in mild COPD and high-risk populations

    Science.gov (United States)

    Chen, Shujing; Wang, Changhui; Li, Bing; Shi, Guochao; Li, Huiping; Zhang, Jing; Gu, Yutong; Zhou, Jian; Song, Yuanlin; Bai, Chunxue

    2017-01-01

    Background Early diagnosis of COPD is often not achieved due to limited recognition and limited access to the pulmonary function test. Our hypothesis was that lung function decline may be different between populations with mild COPD and those who are at high risk and do not receive treatment. Patients and methods Subjects with mild COPD and those from a high-risk COPD population were recruited from a community-based COPD epidemiological study after obtaining consent. Baseline clinical characteristics, symptom questionnaire, spirometry, low-dose computed tomography (LDCT) chest scan, and blood plasma biomarker data were collected initially and then 1 year later. Results A total of 617 participants were recruited, and 438 eventually completed the first-year follow-up visit; 72 participants (46 males) were in the mild COPD group, and 225 participants (165 males) were in the high-risk group. The mean forced expiratory volume in the first second of expiration (FEV1) decline in the mild COPD group was 129 mL, which was significantly higher than the 30 mL decline in the high-risk population group (P=0.005). Group category (odds ratio [OR] =0.230) and COPD Assessment Test (CAT) score (OR =9.912) were independent risk factors for an FEV1% predicted decline of >15% for all participants. In the mild COPD group, patients with a higher CAT (OR =5.310) and Emphysema Index (OR =5.681) were associated with a FEV1% predicted decline of >15% at the first-year follow-up. No factor showed a significantly predictive effect on FEV1 decline in the high-risk COPD group. Conclusion Group category was an independent influential factor associated with FEV1 decline. PMID:28184155

  9. The International Limits and Population at Risk of Plasmodium vivax Transmission in 2009

    Science.gov (United States)

    Guerra, Carlos A.; Howes, Rosalind E.; Patil, Anand P.; Gething, Peter W.; Van Boeckel, Thomas P.; Temperley, William H.; Kabaria, Caroline W.; Tatem, Andrew J.; Manh, Bui H.; Elyazar, Iqbal R. F.; Baird, J. Kevin; Snow, Robert W.; Hay, Simon I.

    2010-01-01

    Background A research priority for Plasmodium vivax malaria is to improve our understanding of the spatial distribution of risk and its relationship with the burden of P. vivax disease in human populations. The aim of the research outlined in this article is to provide a contemporary evidence-based map of the global spatial extent of P. vivax malaria, together with estimates of the human population at risk (PAR) of any level of transmission in 2009. Methodology The most recent P. vivax case-reporting data that could be obtained for all malaria endemic countries were used to classify risk into three classes: malaria free, unstable (<0.1 case per 1,000 people per annum (p.a.)) and stable (≥0.1 case per 1,000 p.a.) P. vivax malaria transmission. Risk areas were further constrained using temperature and aridity data based upon their relationship with parasite and vector bionomics. Medical intelligence was used to refine the spatial extent of risk in specific areas where transmission was reported to be absent (e.g., large urban areas and malaria-free islands). The PAR under each level of transmission was then derived by combining the categorical risk map with a high resolution population surface adjusted to 2009. The exclusion of large Duffy negative populations in Africa from the PAR totals was achieved using independent modelling of the gene frequency of this genetic trait. It was estimated that 2.85 billion people were exposed to some risk of P. vivax transmission in 2009, with 57.1% of them living in areas of unstable transmission. The vast majority (2.59 billion, 91.0%) were located in Central and South East (CSE) Asia, whilst the remainder were located in America (0.16 billion, 5.5%) and in the Africa+ region (0.10 billion, 3.5%). Despite evidence of ubiquitous risk of P. vivax infection in Africa, the very high prevalence of Duffy negativity throughout Central and West Africa reduced the PAR estimates substantially. Conclusions After more than a century of

  10. Modeling the Dynamics of a Non-Limited and a Self-Limited Gene Drive System in Structured Aedes aegypti Populations

    Science.gov (United States)

    Legros, Mathieu; Xu, Chonggang; Morrison, Amy; Scott, Thomas W.; Lloyd, Alun L.; Gould, Fred

    2013-01-01

    Recently there have been significant advances in research on genetic strategies to control populations of disease-vectoring insects. Some of these strategies use the gene drive properties of selfish genetic elements to spread physically linked anti-pathogen genes into local vector populations. Because of the potential of these selfish elements to spread through populations, control approaches based on these strategies must be carefully evaluated to ensure a balance between the desirable spread of the refractoriness-conferring genetic cargo and the avoidance of potentially unwanted outcomes such as spread to non-target populations. There is also a need to develop better estimates of the economics of such releases. We present here an evaluation of two such strategies using a biologically realistic mathematical model that simulates the resident Aedes aegypti mosquito population of Iquitos, Peru. One strategy uses the selfish element Medea, a non-limited element that could permanently spread over a large geographic area; the other strategy relies on Killer-Rescue genetic constructs, and has been predicted to have limited spatial and temporal spread. We simulate various operational approaches for deploying these genetic strategies, and quantify the optimal number of released transgenic mosquitoes needed to achieve definitive spread of Medea-linked genes and/or high frequencies of Killer-Rescue-associated elements. We show that for both strategies the most efficient approach for achieving spread of anti-pathogen genes within three years is generally to release adults of both sexes in multiple releases over time. Even though females in these releases should not transmit disease, there could be public concern over such releases, making the less efficient male-only release more practical. This study provides guidelines for operational approaches to population replacement genetic strategies, as well as illustrates the use of detailed spatial models to assist in safe and

  11. Modeling the dynamics of a non-limited and a self-limited gene drive system in structured Aedes aegypti populations.

    Directory of Open Access Journals (Sweden)

    Mathieu Legros

    Full Text Available Recently there have been significant advances in research on genetic strategies to control populations of disease-vectoring insects. Some of these strategies use the gene drive properties of selfish genetic elements to spread physically linked anti-pathogen genes into local vector populations. Because of the potential of these selfish elements to spread through populations, control approaches based on these strategies must be carefully evaluated to ensure a balance between the desirable spread of the refractoriness-conferring genetic cargo and the avoidance of potentially unwanted outcomes such as spread to non-target populations. There is also a need to develop better estimates of the economics of such releases. We present here an evaluation of two such strategies using a biologically realistic mathematical model that simulates the resident Aedes aegypti mosquito population of Iquitos, Peru. One strategy uses the selfish element Medea, a non-limited element that could permanently spread over a large geographic area; the other strategy relies on Killer-Rescue genetic constructs, and has been predicted to have limited spatial and temporal spread. We simulate various operational approaches for deploying these genetic strategies, and quantify the optimal number of released transgenic mosquitoes needed to achieve definitive spread of Medea-linked genes and/or high frequencies of Killer-Rescue-associated elements. We show that for both strategies the most efficient approach for achieving spread of anti-pathogen genes within three years is generally to release adults of both sexes in multiple releases over time. Even though females in these releases should not transmit disease, there could be public concern over such releases, making the less efficient male-only release more practical. This study provides guidelines for operational approaches to population replacement genetic strategies, as well as illustrates the use of detailed spatial models to

  12. Modeling the dynamics of a non-limited and a self-limited gene drive system in structured Aedes aegypti populations.

    Science.gov (United States)

    Legros, Mathieu; Xu, Chonggang; Morrison, Amy; Scott, Thomas W; Lloyd, Alun L; Gould, Fred

    2013-01-01

    Recently there have been significant advances in research on genetic strategies to control populations of disease-vectoring insects. Some of these strategies use the gene drive properties of selfish genetic elements to spread physically linked anti-pathogen genes into local vector populations. Because of the potential of these selfish elements to spread through populations, control approaches based on these strategies must be carefully evaluated to ensure a balance between the desirable spread of the refractoriness-conferring genetic cargo and the avoidance of potentially unwanted outcomes such as spread to non-target populations. There is also a need to develop better estimates of the economics of such releases. We present here an evaluation of two such strategies using a biologically realistic mathematical model that simulates the resident Aedes aegypti mosquito population of Iquitos, Peru. One strategy uses the selfish element Medea, a non-limited element that could permanently spread over a large geographic area; the other strategy relies on Killer-Rescue genetic constructs, and has been predicted to have limited spatial and temporal spread. We simulate various operational approaches for deploying these genetic strategies, and quantify the optimal number of released transgenic mosquitoes needed to achieve definitive spread of Medea-linked genes and/or high frequencies of Killer-Rescue-associated elements. We show that for both strategies the most efficient approach for achieving spread of anti-pathogen genes within three years is generally to release adults of both sexes in multiple releases over time. Even though females in these releases should not transmit disease, there could be public concern over such releases, making the less efficient male-only release more practical. This study provides guidelines for operational approaches to population replacement genetic strategies, as well as illustrates the use of detailed spatial models to assist in safe and

  13. Quantitative Analysis on the Relationship between Population Distribution and Environment Factors in Mountain Area

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    [Objective] The aim was to analyze the relationship between population distribution and environment factors in mountain area quantitatively.[Method] Taking the contiguous area of Sichuan,Yunnan and Guizhou Province as study object,population density and residential point density were chosen as the indices of population distribution,and the quantitative relationship between population distribution and environment factors (including altitude,topography relief amplitude,land use,road network and river network)...

  14. Public assistance, drug testing, and the law: the limits of population-based legal analysis.

    Science.gov (United States)

    Player, Candice T

    2014-01-01

    In Populations, Public Health and the Law, legal scholar Wendy Parmet urges courts to embrace population-based legal analysis, a public health inspired approach to legal reasoning. Parmet contends that population-based legal analysis offers a way to analyze legal issues--not unlike law and economics--as well as a set of values from which to critique contemporary legal discourse. Population-based analysis has been warmly embraced by the health law community as a bold new way of analyzing legal issues. Still, population-based analysis is not without its problems. At times, Parmet claims too much territory for the population perspective. Moreover, Parmet urges courts to recognize population health as an important norm in legal reasoning. What should we do when the insights of public health and conventional legal reasoning conflict? Still in its infancy, population-based analysis offers little in the way of answers to these questions. This Article applies population-based legal analysis to the constitutional problems that arise when states condition public assistance benefits on passing a drug test, thereby highlighting the strengths of the population perspective and exposing its weaknesses.

  15. Understanding early contextual and parental risk factors for the development of limited prosocial emotions

    OpenAIRE

    Waller, Rebecca; Shaw, Daniel S.; Forbes, Erika E.; Hyde, Luke W.

    2015-01-01

    A growing body of evidence suggests that parenting influences the development of youth callous unemotional (CU) behavior. However, less is known about the effects of parenting or contextual risk factors on ‘limited prosocial emotions’ (LPE), a recent conceptualization of CU behavior added to the DSM-5. We focused on LPE at ages 10–12 and age 20 among low income, urban males (N = 310), and examined potential developmental precursors, including contextual risk factors assessed during infancy an...

  16. Monitoring population disability: Evaluation of a new Global Activity Limitation Indicator (GALI)

    NARCIS (Netherlands)

    Oyen, H. van; Heyden, J.; Perenboom, R.; Jagger, C.

    2006-01-01

    Objective: To evaluate a single item instrument, the Global Activity Limitation Indicator (GALI), to measure long-standing health related activity limitations, against several health indicators: a composite morbidity indicator, instruments measuring mental health (SCL-90R, GHQ-12), physical

  17. Proximate Population Factors and Deforestation in Tropical Agricultural Frontiers

    OpenAIRE

    Carr, David L.

    2004-01-01

    Forest conversion for agriculture expansion is the most salient signature of human occupation of the earth’s land surface. Although population growth and deforestation are significantly associated at the global and regional scales, evidence for population links to deforestation at micro-scales—where people are actually clearing0020forests—is scant. Much of the planet’s forest elimination is proceeding along tropical agricultural frontiers. This article examines the evolution of thought on pop...

  18. Environmental factors influence lesser scaup migration chronology and population monitoring

    Science.gov (United States)

    Finger, Taylor A.; Afton, Alan D.; Schummer, Michael L.; Petrie, Scott A.; Badzinski, Shannon S.; Johnson, Michael A.; Szymanski, Michael L.; Jacobs, Kevin J.; Olsen, Glenn H.; Mitchell, Mark

    2016-01-01

    Identifying environmental metrics specific to lesser scaup (Aythya affinis; scaup) spring migration chronology may help inform development of conservation, management and population monitoring. Our objective was to determine how environmental conditions influence spring migration of lesser scaup to assess the effectiveness of the Waterfowl Breeding Population and Habitat Survey in accurately estimating scaup populations. We first compared peak timing of mallard (Anas platyrhynchos) and scaup migration from weekly ground surveys in North Dakota, USA because the Waterfowl Breeding Population and Habitat Survey is designed to capture annual mallard migration. As predicted, we detected that peak timing of scaup and mallard migrations differed in 25 of 36 years investigated (1980–2010). We marked scaup with satellite transmitters (n = 78; 7,403 locations) at Long Point, Lake Erie, Ontario, Canada; Pool 19 of the Mississippi River, Iowa and Illinois, USA; and Presque Isle Bay, Lake Erie, Pennsylvania, USA. We tested the assumption that our marked scaup were representative of the continental population using the traditional survey area by comparing timing of migration of marked birds and scaup counted in the North Dakota Game and Fish Department survey. We detected a strong positive correlation between marked scaup and the survey data, which indicated that marked scaup were representative of the population. We subsequently used our validated sample of marked scaup to investigate the effects of annual variation in temperature, precipitation, and ice cover on spring migration chronology in the traditional and eastern survey areas of the Waterfowl Breeding Population and Habitat Survey, 2005–2010. We evaluated competing environmental models to explain variation in timing and rate of scaup migration at large-scale and local levels. Spring migration of scaup occurred earlier and faster during springs with warmer temperatures and greater precipitation, variables known

  19. Functional limitation and associated factors in outpatients with ankylosing spondylitis in Southwest China.

    Science.gov (United States)

    Song, Yuqing; Wang, Chen; Chen, Hong

    2017-04-01

    Functional limitation is often complained by patients with ankylosing spondylitis (AS). With a rising number of patients suffering from AS, there are a limited number of reports focusing on functional limitation of AS in Chinese patients. This study was conducted to investigate the level of functional limitation and explore its associations with demographic, disease-related factors. A total of 303 AS outpatients were recruited in this cross-sectional study from a tertiary general hospital in Southwest China. Functional limitation was measured by the Bath Ankylosing Spondylitis Functional Index (BASFI). Other data were collected by the following questionnaires: the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), the Bath Ankylosing Spondylitis Patient Global Score (BAS-G), and the Pittsburgh Sleep Quality Index Questionnaire (PSQI). Finally, 295 outpatients with AS completed this survey. The median BASFI was 0.80. Worse function limitation was found in outpatients with extra-spinal manifestation, older age, lower household income, more back pain, higher disease activity and morning stiffness, poorer sleep, and worse patient's well-being (all P < 0.05). Multivariate regression analysis indicated that patient's well-being (P < 0.001), disease activity (P < 0.001), and disease duration (P < 0.05) were the positive predictors of functional limitation. AS outpatients in Southwest China had a mild level of functional limitation. The factors associated with functional limitation included disease duration, disease activity, and patients' well-being, which should be taken into consideration when assessing functional limitation of AS outpatients. Besides, more comprehensive and targeted interventions should be conducted for AS patients as early as possible, which will be effective to improve functional outcome.

  20. Pion Form Factor in Chiral Limit of Hard-Wall AdS/QCD Model

    Energy Technology Data Exchange (ETDEWEB)

    Anatoly Radyushkin; Hovhannes Grigoryan

    2007-12-01

    We develop a formalism to calculate form factor and charge density distribution of pion in the chiral limit using the holographic dual model of QCD with hard-wall cutoff. We introduce two conjugate pion wave functions and present analytic expressions for these functions and for the pion form factor. They allow to relate such observables as the pion decay constant and the pion charge electric radius to the values of chiral condensate and hard-wall cutoff scale. The evolution of the pion form factor to large values of the momentum transfer is discussed, and results are compared to existing experimental data.

  1. Physiological proteins in resource-limited herbivores experiencing a population die-off

    Science.gov (United States)

    Garnier, R.; Bento, A. I.; Hansen, C.; Pilkington, J. G.; Pemberton, J. M.; Graham, A. L.

    2017-08-01

    Nutrient availability is predicted to interact with herbivore population densities. Competition for low quality food at high density may reduce summer food intake, and in turn winter survival. Conversely, low population density may favor physiological recovery through better access to better quality spring forage. Here, we take advantage of the long-term study of the Soay sheep population of St. Kilda (Scotland) to measure plasma protein markers and immunity in two consecutive summers with contrasting population densities. We show that, following a winter die-off resulting in a shift to low population density, albumin and total proteins increased, but only in adult sheep. The effect was not solely attributable to selective disappearance of malnourished sheep. Similarly, the concentration of antibodies was higher following the die-off, potentially indicating recovery of immune function. Overall, our results are consistent with the physiological recovery of surviving individuals after a harsh winter.

  2. Sleep complaints in the Brazilian population: Impact of socioeconomic factors.

    Science.gov (United States)

    Hirotsu, Camila; Bittencourt, Lia; Garbuio, Silverio; Andersen, Monica Levy; Tufik, Sergio

    2014-09-01

    National surveys are relevant for the study of sleep epidemiology since they can provide specific data about sleep in large dimension with important implications for the health system. Thus, the aim of this study was to investigate the prevalence of sleep complaints among the Brazilian population using a randomized cluster sample according to region and socioeconomic class. For this, a 3-stage sampling technique was used to randomly select Brazilian subjects of both genders older than 16 years. A total of 2017 subjects, from 132 different cities, were selected to estimate prevalence in the Brazilian population with a sampling error of ±2%. Questions about sleep complaints were administered face-to-face by Instituto Datafolha interviewers on April 10 and 16, 2012. Data were expanded using a weighted variable. The results showed that 76% of the study population suffers from at least 1 sleep complaint, indicating that approximately 108 million Brazilians may be affected by sleep disorders. On average, each subject had 1.9 sleep problems with the most common complaints being light and insufficient sleep, snoring, moving a lot during sleep, and insomnia, which usually occurred more than 3 times per week. Low income was associated with higher number of sleep complaints only in Northeast and Southeast regions. In conclusion, this study showed a high prevalence of sleep complaints in a sample of the Brazilian population, suggesting that sleep disorders may be markedly frequent in the Brazilian population with a possible correlation with the socioeconomic situation of the interviewed subjects.

  3. Sleep complaints in the Brazilian population: Impact of socioeconomic factors

    Directory of Open Access Journals (Sweden)

    Camila Hirotsu

    2014-09-01

    Full Text Available National surveys are relevant for the study of sleep epidemiology since they can provide specific data about sleep in large dimension with important implications for the health system. Thus, the aim of this study was to investigate the prevalence of sleep complaints among the Brazilian population using a randomized cluster sample according to region and socioeconomic class. For this, a 3-stage sampling technique was used to randomly select Brazilian subjects of both genders older than 16 years. A total of 2017 subjects, from 132 different cities, were selected to estimate prevalence in the Brazilian population with a sampling error of ±2%. Questions about sleep complaints were administered face-to-face by Instituto Datafolha interviewers on April 10 and 16, 2012. Data were expanded using a weighted variable. The results showed that 76% of the study population suffers from at least 1 sleep complaint, indicating that approximately 108 million Brazilians may be affected by sleep disorders. On average, each subject had 1.9 sleep problems with the most common complaints being light and insufficient sleep, snoring, moving a lot during sleep, and insomnia, which usually occurred more than 3 times per week. Low income was associated with higher number of sleep complaints only in Northeast and Southeast regions. In conclusion, this study showed a high prevalence of sleep complaints in a sample of the Brazilian population, suggesting that sleep disorders may be markedly frequent in the Brazilian population with a possible correlation with the socioeconomic situation of the interviewed subjects.

  4. Colorado Plateau Rapid Ecoregion Assessment Conservation Elements - Terrestrial Species: Greater Sage-Grouse Limiting Factors

    Data.gov (United States)

    Bureau of Land Management, Department of the Interior — This map presents limiting factors for Greater Sage-grouse for an area in the northern part of the ecoregion. This was used for the sage-grouse insert in the final...

  5. Factors that Limit and Enable Preschool-Aged Children's Physical Activity on Child Care Centre Playgrounds

    Science.gov (United States)

    Coleman, Bianca; Dyment, Janet E.

    2013-01-01

    The incidence of childhood obesity amongst preschool-aged children has increased dramatically in recent years and can be attributed, in part, to a lack of physical activity amongst children in this age group. This study explores the social factors that stand to limit and/or enable children's physical activity opportunities in outdoor settings in…

  6. What is the most prominent factor limiting photosynthesis in different layers of a greenhouse cucumber canopy?

    NARCIS (Netherlands)

    Chen, T.W.; Henke, M.; Visser, de P.H.B.; Buck-Sorlin, G.H.; Wiechers, D.; Kahlen, K.; Stützel, H.

    2014-01-01

    Background and Aims Maximizing photosynthesis at the canopy level is important for enhancing crop yield, and this requires insights into the limiting factors of photosynthesis. Using greenhouse cucumber (Cucumis sativus) as an example, this study provides a novel approach to quantify different compo

  7. Trophic scaling and occupancy analysis reveals a lion population limited by top-down anthropogenic pressure in the Limpopo National Park, Mozambique.

    Directory of Open Access Journals (Sweden)

    Kristoffer T Everatt

    Full Text Available The African lion (Panthera Leo has suffered drastic population and range declines over the last few decades and is listed by the IUCN as vulnerable to extinction. Conservation management requires reliable population estimates, however these data are lacking for many of the continent's remaining populations. It is possible to estimate lion abundance using a trophic scaling approach. However, such inferences assume that a predator population is subject only to bottom-up regulation, and are thus likely to produce biased estimates in systems experiencing top-down anthropogenic pressures. Here we provide baseline data on the status of lions in a developing National Park in Mozambique that is impacted by humans and livestock. We compare a direct density estimate with an estimate derived from trophic scaling. We then use replicated detection/non-detection surveys to estimate the proportion of area occupied by lions, and hierarchical ranking of covariates to provide inferences on the relative contribution of prey resources and anthropogenic factors influencing lion occurrence. The direct density estimate was less than 1/3 of the estimate derived from prey resources (0.99 lions/100 km² vs. 3.05 lions/100 km². The proportion of area occupied by lions was Ψ = 0.439 (SE = 0.121, or approximately 44% of a 2,400 km2 sample of potential habitat. Although lions were strongly predicted by a greater probability of encountering prey resources, the greatest contributing factor to lion occurrence was a strong negative association with settlements. Finally, our empirical abundance estimate is approximately 1/3 of a published abundance estimate derived from opinion surveys. Altogether, our results describe a lion population held below resource-based carrying capacity by anthropogenic factors and highlight the limitations of trophic scaling and opinion surveys for estimating predator populations exposed to anthropogenic pressures. Our study provides the first

  8. Towards lag phase of microbial populations at growth-limiting conditions: The role of the variability in the growth limits of individual cells.

    Science.gov (United States)

    Aguirre, Juan S; Koutsoumanis, Konstantinos P

    2016-05-02

    The water activity (aw) growth limits of unheated and heat stressed Listeria monocytogenes individual cells were studied. The aw limits varied from 0.940 to 0.997 and 0.951 to 0.997 for unheated and heat stressed cells, respectively. Due to the above variability a decrease in aw results in the presence of a non-growing fraction in the population leading to an additional pseudo-lag in population growth. In this case the total apparent lag of the population is the sum of the physiological lag of the growing cells (time required to adjust to the new environment) and the pseudo-lag. To investigate the effect of aw on the above lag components, the growth kinetics of L. monocytogenes on tryptone soy agar with aw adjusted to values ranging from 0.997 to 0.940 was monitored. The model of B&R was fitted to the data for the estimation of the apparent lag. In order to estimate the physiological lag of the growing fraction of the inoculum, the model was refitted to the growth data using as initial population level the number of cells that were able to grow (estimated from the number of colonies formed on the agar at the end of storage) and excluding the rest data during the lag. The results showed that for the unheated cells the apparent lag was almost identical to the physiological lag for aw values ranging from 0.997 to 0.970, as the majority of the cells in the initial population was able to grow in these conditions. As the aw decreased from 0.970 to 0.940 however, the number of cells in the population which were able to grow, decreased resulting to an increase in the pseudo-lag. The maximum value of pseudo-lag was 13.1h and it was observed at aw=0.940 where 10% of the total inoculated cells were able to grow. For heat stressed populations a pseudo-lag started to increase at higher aw conditions (0.982) compared to unheated cells. In contrast to the apparent lag, a linear relation between physiological lag and aw was observed for both unheated and heat stressed cells.

  9. Molecular markers reveal limited population genetic structure in a North American corvid, Clark's nutcracker (Nucifraga columbiana).

    Science.gov (United States)

    Dohms, Kimberly M; Burg, Theresa M

    2013-01-01

    The genetic impact of barriers and Pleistocene glaciations on high latitude resident species has not been widely investigated. The Clark's nutcracker is an endemic North American corvid closely associated with Pinus-dominated forests. The nutcracker's encompasses known barriers to dispersal for other species, and glaciated and unglaciated areas. Clark's nutcrackers also irruptively disperse long distances in search of pine seed crops, creating the potential for gene flow among populations. Using the highly variable mitochondrial DNA control region, seven microsatellite loci, and species distribution modeling, we examined the effects of glaciations and dispersal barriers on population genetic patterns and population structure of nutcrackers. We sequenced 900 bp of mitochondrial control region for 169 individuals from 15 populations and analysed seven polymorphic microsatellite loci for 13 populations across the Clark's nutcracker range. We used species distribution modeling and a range of phylogeographic analyses to examine evolutionary history. Clark's nutcracker populations are not highly differentiated throughout their range, suggesting high levels of gene flow among populations, though we did find some evidence of isolation by distance and peripheral isolation. Our analyses suggested expansion from a single refugium after the last glacial maximum, but patterns of genetic diversity and paleodistribution modeling of suitable habitat were inconclusive as to the location of this refugium. Potential barriers to dispersal (e.g. mountain ranges) do not appear to restrict gene flow in Clark's nutcracker, and postglacial expansion likely occurred quickly from a single refugium located south of the ice sheets.

  10. Molecular markers reveal limited population genetic structure in a North American corvid, Clark's nutcracker (Nucifraga columbiana.

    Directory of Open Access Journals (Sweden)

    Kimberly M Dohms

    Full Text Available The genetic impact of barriers and Pleistocene glaciations on high latitude resident species has not been widely investigated. The Clark's nutcracker is an endemic North American corvid closely associated with Pinus-dominated forests. The nutcracker's encompasses known barriers to dispersal for other species, and glaciated and unglaciated areas. Clark's nutcrackers also irruptively disperse long distances in search of pine seed crops, creating the potential for gene flow among populations. Using the highly variable mitochondrial DNA control region, seven microsatellite loci, and species distribution modeling, we examined the effects of glaciations and dispersal barriers on population genetic patterns and population structure of nutcrackers. We sequenced 900 bp of mitochondrial control region for 169 individuals from 15 populations and analysed seven polymorphic microsatellite loci for 13 populations across the Clark's nutcracker range. We used species distribution modeling and a range of phylogeographic analyses to examine evolutionary history. Clark's nutcracker populations are not highly differentiated throughout their range, suggesting high levels of gene flow among populations, though we did find some evidence of isolation by distance and peripheral isolation. Our analyses suggested expansion from a single refugium after the last glacial maximum, but patterns of genetic diversity and paleodistribution modeling of suitable habitat were inconclusive as to the location of this refugium. Potential barriers to dispersal (e.g. mountain ranges do not appear to restrict gene flow in Clark's nutcracker, and postglacial expansion likely occurred quickly from a single refugium located south of the ice sheets.

  11. The Nutraceutical Bioavailability Classification Scheme: Classifying Nutraceuticals According to Factors Limiting their Oral Bioavailability.

    Science.gov (United States)

    McClements, David Julian; Li, Fang; Xiao, Hang

    2015-01-01

    The oral bioavailability of a health-promoting dietary component (nutraceutical) may be limited by various physicochemical and physiological phenomena: liberation from food matrices, solubility in gastrointestinal fluids, interaction with gastrointestinal components, chemical degradation or metabolism, and epithelium cell permeability. Nutraceutical bioavailability can therefore be improved by designing food matrices that control their bioaccessibility (B*), absorption (A*), and transformation (T*) within the gastrointestinal tract (GIT). This article reviews the major factors influencing the gastrointestinal fate of nutraceuticals, and then uses this information to develop a new scheme to classify the major factors limiting nutraceutical bioavailability: the nutraceutical bioavailability classification scheme (NuBACS). This new scheme is analogous to the biopharmaceutical classification scheme (BCS) used by the pharmaceutical industry to classify drug bioavailability, but it contains additional factors important for understanding nutraceutical bioavailability in foods. The article also highlights potential strategies for increasing the oral bioavailability of nutraceuticals based on their NuBACS designation (B*A*T*).

  12. [Factors affecting access to health care institutions by the internally displaced population in Colombia].

    Science.gov (United States)

    Mogollón-Pérez, Amparo Susana; Vázquez, María Luisa

    2008-04-01

    In Colombia, the on-going armed conflict causes displacement of thousands of persons that suffer its economic, social, and health consequences. Despite government regulatory efforts, displaced people still experience serious problems in securing access to health care. In order to analyze the institutional factors that affect access to health care by the internally displaced population, a qualitative, exploratory, and descriptive study was carried out by means of semi-structured individual interviews with a criterion sample of stakeholders (81). A narrative content analysis was performed, with mixed generation of categories and segmentation of data by themes and informants. Inadequate funding, providers' problems with reimbursement by insurers, and lack of clear definition as to coverage under the Social Security System in Health pose barriers to access to health care by the internally displaced population. Bureaucratic procedures, limited inter- and intra-sector coordination, and scarce available resources for public health service providers also affect access. Effective government action is required to ensure the right to health care for this population.

  13. Nitrogen limitation in natural populations of cyanobacteria (Spirulina and Oscillatoria spp. ) and its effect on macromolecular synthesis

    Energy Technology Data Exchange (ETDEWEB)

    van Rijn, J.; Shilo, M.

    1986-08-01

    Natural populations of the cyanobacteria Spirulina species and Oscillatoria species obtained from Israeli fish ponds were limited in growth by nitrogen availability in summer. Physiological indicators for nitrogen limitation, such as phycocyanin, chlorophyll a, and carbohydrate content, did not show clear evidence for nitrogen limited growth, since these organisms are capable of vertical migration from and to the nitrogen-rich bottom. By means of /sup 14/C labeling of the cells under simulated pond conditions followed by cell fractionation into macromolecular compounds, it was found that carbohydrates synthesized at the lighted surface were partially utilized for dark protein synthesis at the bottom of these ponds.

  14. Scaling Solution in the Large Population Limit of the General Asymmetric Stochastic Luria-Delbrück Evolution Process

    Science.gov (United States)

    Kessler, David A.; Levine, Herbert

    2015-02-01

    One of the most popular models for quantitatively understanding the emergence of drug resistance both in bacterial colonies and in malignant tumors was introduced long ago by Luria and Delbrück. Here, individual resistant mutants emerge randomly during the birth events of an exponentially growing sensitive population. A most interesting limit of this process occurs when the population size is large and mutation rates are low, but not necessarily small compared to . Here we provide a scaling solution valid in this limit, making contact with the theory of Levy -stable distributions, in particular one discussed long ago by Landau. One consequence of this association is that moments of the distribution are highly misleading as far as characterizing typical behavior. A key insight that enables our solution is that working in the fixed population size ensemble is not the same as working in a fixed time ensemble. Some of our results have been presented previously in abbreviated form [12].

  15. The Fleming-Viot limit of an interacting spatial population with fast density regulation

    CERN Document Server

    Gupta, Ankit

    2012-01-01

    We consider population models in which the individuals reproduce, die and also migrate in space. The population size scales according to some parameter $N$, which can have different interpretations depending on the context. Each individual is assigned a mass of 1/N and the total mass in the system is called population density. The dynamics has an intrinsic density regulation mechanism that drives the population density towards an equilibrium. We show that under a timescale separation between the slow migration mechanism and the fast density regulation mechanism, the population dynamics converges to a Fleming-Viot process as the scaling parameter $N \\to \\infty$. We first prove this result for a basic model in which the birth and death rates can only depend on the population density. In this case we obtain a neutral Fleming-Viot process. We then extend this model by including position-dependence in the birth and death rates, as well as, offspring dispersal and immigration mechanisms. We show how these extension...

  16. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    DEFF Research Database (Denmark)

    Leirs, Herwig; Steneth, Nils Chr.; Nichols, James D.

    1997-01-01

    , but clear examples of both processes acting in the same population are rare(7,8). Key-factor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide...

  17. Impact of Macro-economic Factors on Deposit Formation by Ukrainian Population

    Directory of Open Access Journals (Sweden)

    Shevaldina Valentyna H.

    2014-01-01

    Full Text Available The goal of the article is detection of interconnections between the common economic processes and formation of bank deposits by population. The article builds a correlation and regression model of complex assessment of interconnection between macro-economic factors, savings behaviour of population and level of deposits of population in banks for two hour horizons: short-term, which is characterised with deployment of crisis phenomena both in global economy and in Ukrainian economy and the medium-term one. The article characterises the most significant common macro-economic factors. In the result of the study the article establishes that Ukrainian population is oriented at short-term horizon when forming savings due to the uncertainty in future. In the medium-term prospective, savings of the population are formed basically under influence of macro-economic factors, while formation of deposits by Ukrainian population is mostly influenced by socio-psychological factors.

  18. FACTORS IMPLICATED IN AMPHIBIAN POPULATION DECLINES IN THE UNITED STATES

    Science.gov (United States)

    This study identified the factors responsible for the decline of native amphibians in the U.S. The type of land use, the introduction of exotic animal species, and chemical contamination were identified as the most likely causes of decline.

  19. Factors Influencing Food Choice in the Elderly Mauritian Population

    African Journals Online (AJOL)

    admpather

    Only the factor of taste influencing food choice was significantly different between the two ..... available through the media, promotions, and advertising may confuse consumers and cause ... Predictors of self-initiated, healthful dietary change.

  20. Factors limiting the establishment of canopy-forming algae on artificial structures

    Science.gov (United States)

    Cacabelos, Eva; Martins, Gustavo M.; Thompson, Richard; Prestes, Afonso C. L.; Azevedo, José Manuel N.; Neto, Ana I.

    2016-11-01

    Macroalgal canopies are important ecosystem engineers, contributing to coastal productivity and supporting a rich assemblage of associated flora and fauna. However, they are often absent from infrastructures such as coastal defences and there has been a worldwide decline in their distribution in urbanised coastal areas. The macroalga Fucus spiralis is the only high-shore canopy forming species present in the Azores. It is widely distributed in the archipelago but is never found on coastal infrastructures. Here we evaluate factors that may potentially limit its establishment on artificial structures. A number of observational and manipulative experiments were used to test the hypotheses that: (i) limited-dispersal ability limits the colonisation of new plants onto artificial structures, (ii) vertical substratum slope negatively influences the survivorship of recruits, and (iii) vertical substratum slope also negatively influences the survivorship and fitness of adults. Results showed that the limited dispersal from adult plants may be a more important factor than slope in limiting the species ability to colonise coastal infrastructures, since the vertical substratum slope does not affect its fitness or survivorship.

  1. New Precision Limit on the Strange Vector Form Factors of the Proton

    CERN Document Server

    Ahmed, Z; Aniol, K A; Armstrong, D S; Arrington, J; Baturin, P; Bellini, V; Benesch, J; Beminiwattha, R; Benmokhtar, F; Canan, M; Camsonne, A; Cates, G D; Chen, J -P; Chudakov, E; Cisbani, E; Dalton, M M; de Jager, C W; De Leo, R; Deconinck, W; Decowski, P; Deng, X; Deur, A; Dutta, C; Franklin, G B; Friend, M; Frullani, S; Garibaldi, F; Giusa, A; Glamazdin, A; Golge, S; Grimm, K; Hansen, O; Higinbotham, D W; Holmes, R; Holmstrom, T; Huang, J; Huang, M; Hyde, C E; Jen, C M; Jin, G; Jones, D; Kang, H; King, P; Kowalski, S; Kumar, K S; Lee, J H; LeRose, J J; Liyanage, N; Long, E; McNulty, D; Margaziotis, D; Meddi, F; Meekins, D G; Mercado, L; Meziani, Z -E; Michaels, R; Munoz-Camacho, C; Mihovilovic, M; Muangma, N; Myers, K E; Nanda, S; Narayan, A; Nelyubin, V; Nuruzzaman,; Oh, Y; Pan, K; Parno, D; Paschke, K D; Phillips, S K; Qian, X; Qiang, Y; Quinn, B; Rakhman, A; Reimer, P E; Rider, K; Riordan, S; Roche, J; Rubin, J; Russo, G; Saenboonruang, K; Saha, A; Sawatzky, B; Silwal, R; Sirca, S; Souder, P A; Sperduto, M; Subedi, R; Suleiman, R; Sulkosky, V; Sutera, C M; Tobias, W A; Urciuoli, G M; Waidyawansa, B; Wang, D; Wexler, J; Wilson, R; Wojtsekhowski, B; Zhan, X; Yan, X; Yao, H; Ye, L; Zhao, B; Zheng, X

    2011-01-01

    The parity-violating cross-section asymmetry in the elastic scattering of polarized electrons from unpolarized protons has been measured at a four-momentum transfer squared Q2 = 0.624 GeV and beam energy E =3.48 GeV to be A_PV = -23.80 +/- 0.78 (stat) +/- 0.36 (syst) parts per million. This result is consistent with zero contribution of strange quarks to the combination of electric and magnetic form factors G_E^s + 0.517 G_M^s = 0.003 +/- 0.010 (stat) +/- 0.004 (syst) +/- 0.009 (ff), where the third error is due to the limits of precision on the electromagnetic form factors and radiative corrections. With this measurement, the world data on strange contributions to nucleon form factors are seen to be consistent with zero and not more than a few percent of the proton form factors.

  2. Risk factors for intracranial aneurysm in a Chinese ethnic population

    Institute of Scientific and Technical Information of China (English)

    GU Yu-xiang; CHEN Xian-cheng; SONG Dong-lei; LENG Bing; ZHAO Fan

    2006-01-01

    Background Intracranial aneurysm (IAN) is a protruding bubble or a sac on a brain artery that balloons out over time, which may lead to spontaneous subarachnoid hemorrhage (SAH), ultimately disability and mortality.Current research indicates that the disease is due to multiple causes, including environmental factors and various congenital abnormalities of blood vessels. Apart from congenital predisposition, various high-risk factors such as sex, age, hypertension, and atherosclerosis are involved in the formation of intracranial aneurysms. The aim of this study was to investigate the risk factors associated with the formation of sporadic intracranial aneurysms in Chinese Han ethnic patients.Methods A total of 251 patients with intracranial aneurysm and 338 patients with other cerebral diseases (control group) were enrolled in this study. Single factor and logistic regression model were used to analyze the association of intracranial aneurysms with age; sex; cigarette smoking; alcohol or cocaine consumption; history of hypertension, coronary artery disease, diabetes mellitus and inherited connective tissue disease; and the levels of fasting blood glucose and blood fat. The data expressed as mean ± standard deviation were processed with the statistical software SPSS13. Quantitative and qualitative data were analyzed by the independent-sample t test,and the chi-square test respectively. Logistic regression method was used to analyze the multiple factors.Results In the 251 patients, 163 (64.94%) were at age of 40 to 60 years. Sex (OR, 1.41; 95% CI, 1.01-1.96), cigarette smoking (OR, 1.81; 95% CI, 1.06-3.10), hypertension (OR, 2.32; 95% CI, 1.30-4.16) and fasting blood glucose were significantly associated with intracranial aneurysm (P<0.05). Intracranial aneurysm was correlated with alcohol consumption, coronary artery disease, and the level of blood lipids (P>0.05). Using logistic regression analysis, we identified female sex and advanced age as significant risk

  3. Demographic factors and genetic variation influence population persistence under environmental change.

    Science.gov (United States)

    Willi, Yvonne; Hoffmann, Ary A

    2009-01-01

    Population persistence has been studied in a conservation context to predict the fate of small or declining populations. Persistence models have explored effects on extinction of random demographic and environmental fluctuations, but in the face of directional environmental change they should also integrate factors affecting whether a population can adapt. Here, we examine the population-size dependence of demographic and genetic factors and their likely contributions to extinction time under scenarios of environmental change. Parameter estimates were derived from experimental populations of the rainforest species, Drosophila birchii, held in the lab for 10 generations at census sizes of 20, 100 and 1000, and later exposed to five generations of heat-knockdown selection. Under a model of directional change in the thermal environment, rapid extinction of populations of size 20 was caused by a combination of low growth rate (r) and high stochasticity in r. Populations of 100 had significantly higher reproductive output, lower stochasticity in r and more additive genetic variance (V(A)) than populations of 20, but they were predicted to persist less well than the largest size class. Even populations of 1000 persisted only a few hundred generations under realistic estimates of environmental change because of low V(A) for heat-knockdown resistance. The experimental results document population-size dependence of demographic and adaptability factors. The simulations illustrate a threshold influence of demographic factors on population persistence, while genetic variance has a more elastic impact on persistence under environmental change.

  4. Limited divergence among populations of rice striped stem borer in southeast China caused by gene flow: Implications for resistance management

    Institute of Scientific and Technical Information of China (English)

    Chao YANG; Xiao YANG; Qiang FU; Kai XU; Bao-Rong LU

    2012-01-01

    Rice striped stem borer (RSSB,Chilo suppressalis) is a serious lepidopteron pest occurring in rice ecosystems of Asia and Europe.Genetically modified (GM) insect-resistant Bt rice has been developed to deter lepidopteron pests including RSSB.The concern of resistance evolution to the Bt toxin by the pests under commercial cultivation of GM Bt rice and the need of effective management of the resistance encourage the studies of genetic variation and divergence,as well as gene flow of RSSB populations.We analyzed 13 RSSB populations fed on water-oats or rice plants,respectively,from southeast China applying the fluorescent amplified fragment length polymorphism fingerprints.A generally moderate level of genetic variation was detected in the populations,as estimated by Nei's genetic diversity (0.27) and Shannon's index (0.42).The FsT- and AMOVA values indicated a low level (~ 12%) of genetic divergence among the RSSB populations.A relatively frequent gene flow (an average Nm =2.62) was detected among the 12 RSSB populations,which may explain the limited genetic divergence among the rice-feeding populations.This explanation gains support by the assignment test of the corresponding populations,suggesting that a considerable proportion of individuals was contributed from non-native populations.Our results revealed that the moderate level of genetic diversity combined with relatively frequent gene flow among RSSB populations across a large geographical range may slow down the resistance evolution of the RSSB populations,given that a proper measure of resistance management is taken.

  5. Assessment of the sensory and physical limitations imposed by leprosy in a Brazilian Amazon Population.

    Science.gov (United States)

    Aben-Athar, Cintia Yolette Urbano Pauxis; Lima, Sandra Souza; Ishak, Ricardo; Vallinoto, Antonio Carlos Rosário

    2017-01-01

    Leprosy often results in sensory and physical limitations. This study aimed to evaluate these limitations using a quantitative approach in leprosy patients in Belém (Pará, Brazil). This epidemiological, cross-sectional study measured the sensory impairment of smell and taste through the use of a questionnaire and evaluated activity limitations of daily life imposed by leprosy through the Screening of Activity Limitation and Safety Awareness (SALSA) Scale. Data were collected from 84 patients and associations between the degree of disability and clinical and epidemiological characteristics were assessed. The majority of patients were men (64.3%), married (52.4%), age 31-40 years old (26.2%), had primary education (50%), and were independent laborers (36.9%). The multibacillary operational classification (81%), borderline clinical form (57.1%), and 0 degrees of physical disability (41.7%) were predominant. SALSA scores ranged from 17 to 59 points, and being without limitations was predominant (53.6%). The risk awareness score ranged from 0 to 8, with a score of 0 (no awareness of risk) being the most common (56%). Evaluation of smell and taste sensory sensitivities revealed that 70.2% did not experience these sensory changes. Patients with leprosy reactions were 7 times more likely to develop activity limitations, and those who had physical disabilities were approximately four times more likely to develop a clinical picture of activity limitations. Most patients showed no sensory changes, but patients with leprosy reactions were significantly more likely to develop activity limitations. Finally, further studies should be performed, assessing a higher number of patients to confirm the present results.

  6. 25 CFR Appendix B to Subpart C - Population Adjustment Factor

    Science.gov (United States)

    2010-04-01

    ... Distribution factor* Number of tribes** Funding amount per tribe Less than 25 1 N1 MBA*** × 1 25-100 3.5 N2 MBA × 3.5 101-1000 5.0 N3 MBA × 5.0 1001-10,000 6.5 N4 MBA × 6.5 10,001+ 8 N5 MBA × 8 * Multiplier used to... Minimum Base Allocation (MBA) is the dollar value to be multiplied by the distribution factor for...

  7. Epidemiological factors associated with hypertension among tribal population in Gujarat

    Directory of Open Access Journals (Sweden)

    Bhadresh Mandani, Bhavesh Vaghani, Manishkumar Gorasiya, Parul Patel

    2011-01-01

    Full Text Available Cardiovascular diseases are recognized as major public health problems by WHO. Very few studies have been carried out among tribal population in India. A cross sectional study was carried out in 2005 to find out the magnitude of hypertension among 154 tribal adult of South Gujarat. WHO classification of hypertension was taken as operational criteria and data was collected in pre-designed, pretested schedule. Blood pressure measurement was done twice on each subject using mercury sphygmomanometer. Overall magnitude of hypertension was found to be 16.9%, and only smoking was found to have significantly associated with it.

  8. The adiabatic limit of the exact factorization of the electron-nuclear wave function

    CERN Document Server

    Eich, Florian G

    2016-01-01

    We propose a procedure to analyze the relation between the exact factorization of the electron-nuclear wave function and the Born-Oppenheimer approximation. We define the adiabatic limit as the limit of infinite nuclear mass. To this end, we introduce a unit system that singles out the dependence on the electron-nuclear mass ratio of each term appearing in the equations of the exact factorization. We observe how non-adiabatic effects induced by the coupling to the nuclear motion affect electronic properties and we analyze the leading term, connecting it to the classical nuclear momentum. Its dependence on the mass ratio is tested numerically on a model proton- coupled electron transfer in different non-adiabatic regimes.

  9. Limiting factors for development of ambulatory breast surgery in the French hospital network.

    Science.gov (United States)

    Dravet, F; Peuvrel, P; Robard, S; Labbe, D; Michy, T; François, T; Théard, J-L; Classe, J-M

    2011-04-01

    Ambulatory breast surgery is not well developed in France. This is especially true for oncologic procedures, Between January 2005 and June 2006, we performed a retrospective evaluation of the factors thought to limit the development of this type of hospitalization. The principal limiting factors were distance restrictions (respect of the 100 km perimeter), the complexity of patient management for small breast tumors (several practitioners involved) and last, the non-motivating reimbursement policy. By changing to the Anglo-American ("one day surgery", i.e. hospital stay less than 24 hours) or hybrid system (less than 12 hours+1 day surgery), ambulatory surgery could easily be offered to patients excluded by the current system (ambulatory department open less than 12 hours). Copyright © 2011 Elsevier Masson SAS. All rights reserved.

  10. Geographic and seasonal patterns and limits on the adaptive response to temperature of European Mytilus spp. and Macoma balthica populations.

    Science.gov (United States)

    Jansen, Jeroen M; Pronker, Annelies E; Kube, Sandra; Sokolowski, Adam; Sola, J Carlos; Marquiegui, Mikel A; Schiedek, Doris; Wendelaar Bonga, Sjoerd; Wolowicz, Maciej; Hummel, Herman

    2007-11-01

    Seasonal variations in seawater temperature require extensive metabolic acclimatization in cold-blooded organisms inhabiting the coastal waters of Europe. Given the energetic costs of acclimatization, differences in adaptive capacity to climatic conditions are to be expected among distinct populations of species that are distributed over a wide geographic range. We studied seasonal variations in the metabolic adjustments of two very common bivalve taxa at European scale. To this end we sampled 16 populations of Mytilus spp. and 10 Macoma balthica populations distributed from 39 degrees to 69 degrees N. The results from this large-scale comprehensive comparison demonstrated seasonal cycles in metabolic rates which were maximized during winter and springtime, and often reduced in the summer and autumn. Studying the sensitivity of metabolic rates to thermal variations, we found that a broad range of Q (10) values occurred under relatively cold conditions. As habitat temperatures increased the range of Q (10) narrowed, reaching a bottleneck in southern marginal populations during summer. For Mytilus spp., genetic-group-specific clines and limits on Q (10) values were observed at temperatures corresponding to the maximum climatic conditions these geographic populations presently experience. Such specific limitations indicate differential thermal adaptation among these divergent groups. They may explain currently observed migrations in mussel distributions and invasions. Our results provide a practical framework for the thermal ecophysiology of bivalves, the assessment of environmental changes due to climate change and its impact on (and consequences for) aquaculture.

  11. Population pharmacokinetics and limited sampling strategy for first-line tuberculosis drugs and moxifloxacin

    NARCIS (Netherlands)

    Magis-Escurra, C.; Later-Nijland, H. M. J.; Alffenaar, J. W. C.; Broeders, J.; Burger, D. M.; van Crevel, R.; Boeree, M. J.; Donders, A. R. T.; van Altena, R.; van der Werf, T. S.; Aarnoutse, R. E.

    2014-01-01

    Therapeutic drug monitoring (TDM) of tuberculosis (TB) drugs currently focuses on peak plasma concentrations, yet total exposure [area under the 24-h concentration-time curve (AUC(0-24))] is probably most relevant to the efficacy of these drugs. We therefore assessed population AUC(0-24) data for al

  12. Atomic clock using coherent population trapping in a cesium cell: frequency stability and limitations

    Science.gov (United States)

    Mejri, Sinda; Tricot, Francois; Danet, Jean-Marie; Yun, Peter; De Clercq, Emeric; Guerandel, Stephane

    2016-06-01

    Toward the next generation of compact devices, atomic clocks based on coherent population trapping (CPT) offer a very interesting alternative. We present a review of our studies on the short and mid term stability of a compact high performance atomic clock based on CPT in view of portable applications.

  13. LIMITATION OF POPULATION EXPOSURE INDOORS DUE TO NATURAL IRRADIATION SOURCES: IAEA NEW SAFETY STANDARDS PROJECT

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2013-01-01

    Full Text Available An article contains the analysis of the main expected changes in the setting standards of population exposure from natural sources in connection with the publication of the new IAEA standard «Protection of the Public against Exposure Indoors due to Natural Sources of Radiation».

  14. Limitations to sustainable frankincense production: blocked regeneration, high adult mortality and declining populations

    NARCIS (Netherlands)

    Groenendijk, P.; Eshete, A.; Sterck, F.J.; Zuidema, P.A.; Bongers, F.

    2012-01-01

    1. Resins are highly valued non-timber forest products (NTFP). One of the most widely traded resins is frankincense, tapped from several Boswellia tree species (Burseraceae). Exploited Boswellia populations often show poor regeneration, but the demographic consequences of these bottlenecks are unkno

  15. Impact of selected risk factors on expected lifetime without long-standing, limiting illness in Denmark

    DEFF Research Database (Denmark)

    Brønnum-Hansen, Henrik; Juel, Knud; Davidsen, Michael

    2007-01-01

    OBJECTIVE: To estimate the impacts of tobacco smoking, high alcohol consumption, physical inactivity and overweight on expected lifetime with and without long-standing, limiting illness. METHODS: Life tables for each level of exposure to the risk factors were constructed, mainly on the basis......-olds was 9-10 years shorter for heavy smokers than for those who never smoke, and all the lifetime lost would have been without long-standing, limiting illness. Similarly, all 5 years of expected lifetime lost by men with high alcohol consumption would have been without illness. The expected lifetime without...... long-standing, limiting illness was 8-10 years shorter among sedentary than physically active people. Obesity shortened lifetime without illness by 5 years for men and ten years for women. CONCLUSION: The results of this study could be used in health policy-making, as the potential gains in public...

  16. A population study of neutering status as a risk factor for canine prostate cancer.

    Science.gov (United States)

    Bryan, Jeffrey N; Keeler, Matthew R; Henry, Carolyn J; Bryan, Margaret E; Hahn, Allen W; Caldwell, Charles W

    2007-08-01

    Prostate cancer has been reported to occur more commonly in neutered than intact male dogs in several case series. This study was undertaken to evaluate risk of prostate cancer in a large population database. The hypothesis was that castration is a risk factor for prostate cancer in male companion dogs. Data were derived from recorded visits to North American veterinary teaching hospitals. The Veterinary Medical Databases (VMDB) were queried to yield male dogs with urinary bladder transitional cell carcinoma (TCC), prostate adenocarcinoma (ACA), prostate TCC, prostate carcinoma (CA), and prostate tumors. A second query yielded all male dogs over the age of 4 years without a diagnosis of urinary tract cancer. These populations were compared to determine relative risks for developing each disease, singly and collectively, associated with neutering status. Odds ratios were calculated for breed as a risk factor. Neutered males had a significantly increased risk for each form of cancer. Neutered males had an odds ratio of 3.56 (3.02-4.21) for urinary bladder TCC, 8.00 (5.60-11.42) for prostate TCC, 2.12 (1.80-2.49) for prostate adenocarcinoma, 3.86 (3.13-4.16) for prostate carcinoma, and 2.84 (2.57-3.14) for all prostate cancers. Relative risks were highly similar when cases were limited to those with a histologically confirmed diagnosis. Breed predisposition suggests that genetic factors play a role in the development of prostate cancer. The risk associated with being neutered is highest for TCC, supporting previous work identifying the urothelium and ductular rather than acinar epithelium as the source of these tumors. (c) 2007 Wiley-Liss, Inc.

  17. Population genetics of Agave cocui: evidence for low genetic diversity at the southern geographic limit of genus Agave.

    Science.gov (United States)

    Figueredo, Carmen J; Nassar, Jafet M

    2011-01-01

    The Agave genus embraces many species with outstanding ecological and economic importance in the arid regions of the Americas. Even though this genus covers a broad geographic distribution, our knowledge on the population genetics of species is concentrated in taxa located in North America. Recently, it has been demonstrated that plant domestication decreases levels of genetic diversity in managed populations and increases population structure with respect to wild populations. We examined levels of allozyme diversity (N = 17 loci) and population structure of Agave cocui, the species at the southern limit of distribution of the genus. We sampled 7 wild populations (N = 30-35 individuals per population) representative of the geographic distribution of the species in Venezuela. Among the agaves studied, A. cocui has some of the lowest estimates of genetic diversity (H(e)[species] = 0.059, H(e)[population] = 0.054) reported until present. We propose that this condition is probably linked to the recent origin of this species in arid and semiarid regions of Colombia and Venezuela, probably through one or a few founder events. The lowest estimates of genetic diversity were associated with small populations in very restricted arid patches; but also with overexploitation of rosettes for production of fermented drinks and fibers. Santa Cruz de Pecaya, one of the 2 centers of economic use of agaves in northwestern Venezuela presented one of the lowest values of genetic variability, a sign suggesting that human impact represents a significant threat to the available genetic pool that this species possesses in the region.

  18. Risk factors for early childhood caries in disadvantaged populations.

    Science.gov (United States)

    Arora, Amit; Schwarz, Eli; Blinkhorn, Anthony Stevenson

    2011-11-01

    Early childhood caries is a significant international public health problem. The aim of this paper was to review the current evidence of the risk factors for dental caries in disadvantaged children under 6 years of age. Medline, Cochrane, and PubMed database searches were conducted. Systematic reviews were used where available, or meta-analyses; randomized, controlled trials; and cohort, case-control, and cross-sectional studies (in that order). Studies were restricted to those published in English from 1990 to October 2010. Early childhood caries has a complex etiology with biological, behavioral, and sociodemographic influences. Evidence suggests that young children are most likely to develop caries if Streptococcus mutans is acquired at an early age, although this is influenced by other factors, such as oral hygiene, fluoride, diet, dental visit patterns, socioeconomic status, ethnicity, and health literacy. Etiological pathways should be taken into consideration when designing interventions to prevent dental caries in disadvantaged preschool children.

  19. What is the most prominent factor limiting photosynthesis in different layers of a greenhouse cucumber canopy?

    Science.gov (United States)

    Chen, Tsu-Wei; Henke, Michael; de Visser, Pieter H B; Buck-Sorlin, Gerhard; Wiechers, Dirk; Kahlen, Katrin; Stützel, Hartmut

    2014-09-01

    Maximizing photosynthesis at the canopy level is important for enhancing crop yield, and this requires insights into the limiting factors of photosynthesis. Using greenhouse cucumber (Cucumis sativus) as an example, this study provides a novel approach to quantify different components of photosynthetic limitations at the leaf level and to upscale these limitations to different canopy layers and the whole plant. A static virtual three-dimensional canopy structure was constructed using digitized plant data in GroIMP. Light interception of the leaves was simulated by a ray-tracer and used to compute leaf photosynthesis. Different components of photosynthetic limitations, namely stomatal (S(L)), mesophyll (M(L)), biochemical (B(L)) and light (L(L)) limitations, were calculated by a quantitative limitation analysis of photosynthesis under different light regimes. In the virtual cucumber canopy, B(L) and L(L) were the most prominent factors limiting whole-plant photosynthesis. Diffusional limitations (S(L) + M(L)) contributed Photosynthesis in the lower canopy was more limited by the biochemical capacity, and the upper canopy was more sensitive to light than other canopy parts. Although leaves in the upper canopy received more light, their photosynthesis was more light restricted than in the leaves of the lower canopy, especially when the light condition above the canopy was poor. An increase in whole-plant photosynthesis under diffuse light did not result from an improvement of light use efficiency but from an increase in light interception. Diffuse light increased the photosynthesis of leaves that were directly shaded by other leaves in the canopy by up to 55%. Based on the results, maintaining biochemical capacity of the middle-lower canopy and increasing the leaf area of the upper canopy would be promising strategies to improve canopy photosynthesis in a high-wire cucumber cropping system. Further analyses using the approach described in this study can be expected to

  20. Central limit approximations for Markov population processes with countably many types

    CERN Document Server

    Barbour, A D

    2012-01-01

    When modelling metapopulation dynamics, the influence of a single patch on the metapopulation depends on the number of individuals in the patch. Since there is usually no obvious natural upper limit on the number of individuals in a patch, this leads to systems in which there are countably infinitely many possible types of entity. Analogous considerations apply in the transmission of parasitic diseases. In this paper, we prove central limit theorems for quite general systems of this kind, together with bounds on the rate of convergence in an appropriately chosen weighted $\\ell_1$ norm.

  1. EXAMINATION OF SILICATE LIMITATION OF PRIMARY PRODUCTION IN JIAOZHOU BAY, CHINA Ⅰ. SILICATE BEING A LIMITING FACTOR OF PHYTOPLANKTON PRIMARY PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    杨东方; 张经; 吕吉斌; 高振会; 陈豫

    2002-01-01

    Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou B ay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO-3-N, NO-2-N, NH+4-N, SiO2-3-Si, PO3-4-P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq.(1) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temp erature; that the main factor controlling the primary production is Si; that water temper ature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecologica l niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature's effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay , the biogeochemical sediment process of the silicon, the phytoplankton predominan t species and the phytoplankton structure. The authors considered silicate a limit ing factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and up take by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrins ic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant

  2. EXAMINATION OF SILICATE LIMITATION OF PRIMARY PRODUCTION IN JIAOZHOU BAY, CHINA——I. SILICATE BEING A LIMITING FACTOR OF PHYTOPLANKTON PRIMARY PRODUCTION

    Institute of Scientific and Technical Information of China (English)

    杨东方; 张经; 吕吉斌; 高振会; 陈豫

    2002-01-01

    Jiaozhou Bay data collected from May 1991 to February 1994, in 12 seasonal investigations, and provided the authors by the Ecological Station of Jiaozhou Bay, were analyzed to determine the spatiotemporal variations in temperature, light, nutrients (NO3--N, NO2--N, NH4+-N, SIO32--Si, PO43--P), phytoplankton, and primary production in Jiaozhou Bay. The results indicated that only silicate correlated well in time and space with, and had important effects on, the characteristics, dynamic cycles and trends of, primary production in Jiaozhou Bay. The authors developed a corresponding dynamic model of primary production and silicate and water temperature. Eq. ( 1 ) of the model shows that the primary production variation is controlled by the nutrient Si and affected by water temperature; that the main factor controlling the primary production is Si; that water temperature affects the composition of the structure of phytoplankton assemblage; that the different populations of the phytoplankton assemblage occupy different ecological niches for C, the apparent ratio of conversion of silicate in seawater into phytoplankton biomas and D, the coefficient of water temperature's effect on phytoplankton biomass. The authors researched the silicon source of Jiaozhou Bay, the biogeochemical sediment process of the silicon, the phytoplankton predominant species and the phytoplankton structure. The authors considered silicate a limiting factor of primary production in Jiaozhou Bay, whose decreasing concentration of silicate from terrestrial source is supposedly due to dilution by current and uptake by phytoplankton; quantified the silicate assimilated by phytoplankton, the intrinsic ratio of conversion of silicon into phytoplankton biomass, the proportion of silicate uptaken by phytoplankton and diluted by current; and found that the primary production of the phytoplankton is determined by the quantity of the silicate assimilated by them. The phenomenon of apparently high plant

  3. Thermodynamic limit of particle-hole form factors in the massless XXZ Heisenberg chain

    Energy Technology Data Exchange (ETDEWEB)

    Kitanine, N. [Univ. de Bourgogne (France). IMB, UMR 5584 du CNRS; Kozlowski, K.K. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Maillet, J.M.; Terras, V. [ENS Lyon (France). UMR 5672 du CNRS, Lab. de Physique; Slavnov, N.A. [Steklov Mathematical Inst., Moscow (Russian Federation)

    2011-03-15

    We study the thermodynamic limit of the particle-hole form factors of the XXZ Heisenberg chain in the massless regime. We show that, in this limit, such form factors decrease as an explicitly computed power-law in the system size. Moreover, the corresponding amplitudes can be obtained as a product of a ''smooth'' and a ''discrete'' part: the former depends continuously on the rapidities of the particles and holes, whereas the latter has an additional explicit dependence on the set of integer numbers that label each excited state in the associated logarithmic Bethe equations. We also show that special form factors corresponding to zero-energy excitations lying on the Fermi surface decrease as a power-law in the system size with the same critical exponents as in the longdistance asymptotic behavior of the related two-point correlation functions. The methods we develop in this article are rather general and can be applied to other massless integrable models associated to the six-vertex R-matrix and having determinant representations for their form factors. (orig.)

  4. Reaching the theoretical resonance quality factor limit in coaxial plasmonic nanoresonators fabricated by helium ion lithography.

    Science.gov (United States)

    Melli, M; Polyakov, A; Gargas, D; Huynh, C; Scipioni, L; Bao, W; Ogletree, D F; Schuck, P J; Cabrini, S; Weber-Bargioni, A

    2013-06-12

    Optical antenna structures have revolutionized the field of nano-optics by confining light to deep subwavelength dimensions for spectroscopy and sensing. In this work, we fabricated coaxial optical antennae with sub-10-nanometer critical dimensions using helium ion lithography (HIL). Wavelength dependent transmission measurements were used to determine the wavelength-dependent optical response. The quality factor of 11 achieved with our HIL fabricated structures matched the theoretically predicted quality factor for the idealized flawless gold resonators calculated by finite-difference time-domain (FDTD). For comparison, coaxial antennae with 30 nm critical dimensions were fabricated using both HIL and the more common Ga focus ion beam lithography (Ga-FIB). The quality factor of the Ga-FIB resonators was 60% of the ideal HIL results for the same design geometry due to limitations in the Ga-FIB fabrication process.

  5. Functional Factor Analysis In Sesame Under Water - Limiting Stress: New Concept On An Old Method

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    Mansouri Sadollah

    2014-12-01

    Full Text Available Multivariate statistical analysis, through their ability to extract hidden relationship between various traits, has a wide application in breeding programs. Having physiological concept on the multivariate analysis, factor analysis was used to extract differential relationships between different components involving in assimilate partitioning in sesame under regular irrigation regime and limited irrigation. The analysis revealed that under regular irrigation regime, the stored and/or currently produced assimilates are allocated to the filling seeds. However, incidence of water shortage in the beginning of flowering time make shifts in assimilate partitioning from formation of new seeds or capsules to the not-matured pre-formed seeds, which results in seeds with more nutrient storage. This indicates the requirement for change in breeding strategies under sub-optimal condition. The possible common language between factor concept in multivariate analysis, QTLs in genetics, and transcription factors in molecular biology is indicated.

  6. The Peripheral Arterial disease study (PERART/ARTPER: prevalence and risk factors in the general population

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    Vicheto Marisa

    2010-01-01

    Full Text Available Abstract Background The early diagnosis of atherosclerotic disease is essential for developing preventive strategies in populations at high risk and acting when the disease is still asymptomatic. A low ankle-arm index is a good marker of vascular events and may be diminished without presenting symptomatology (silent peripheral arterial disease. The aim of the study is to know the prevalence and associated risk factors of peripheral arterial disease in the general population. Methods We performed a cross-sectional, multicentre, population-based study in 3786 individuals >49 years, randomly selected in 28 primary care centres in Barcelona (Spain. Peripheral arterial disease was evaluated using the ankle-arm index. Values Results The prevalence (95% confidence interval of peripheral arterial disease was 7.6% (6.7-8.4, (males 10.2% (9.2-11.2, females 5.3% (4.6-6.0; p Multivariate analysis showed the following risk factors: male sex [odds ratio (OR 1.62; 95% confidence interval 1.01-2.59]; age OR 2.00 per 10 years (1.64-2.44; inability to perform physical activity [OR 1.77 (1.17-2.68 for mild limitation to OR 7.08 (2.61-19.16 for breathless performing any activity]; smoking [OR 2.19 (1.34-3.58 for former smokers and OR 3.83 (2.23-6.58 for current smokers]; hypertension OR 1.85 (1.29-2.65; diabetes OR 2.01 (1.42-2.83; previous cardiovascular disease OR 2.19 (1.52-3.15; hypercholesterolemia OR 1.55 (1.11-2.18; hypertriglyceridemia OR 1.55 (1.10-2.19. Body mass index ≥25 Kg/m2 OR 0.57 (0.38-0.87 and walking >7 hours/week OR 0.67 (0.49-0.94 were found as protector factors. Conclusions The prevalence of peripheral arterial disease is low, higher in males and increases with age in both sexes. In addition to previously described risk factors we found a protector effect in physical exercise and overweight.

  7. Local effects of limited recombination: historical perspective and consequences for population estimates of adaptive evolution.

    Science.gov (United States)

    Williford, Anna; Comeron, Josep M

    2010-01-01

    Recent years have witnessed the integration of theoretical advances in population genetics with large-scale analyses of complete genomes, with a growing number of studies suggesting pervasive natural selection that includes frequent deleterious as well as adaptive mutations. In finite populations, however, mutations under selection alter the fate of genetically linked mutations (the so-called Hill-Robertson effect). Here we review the evolutionary consequences of selection at linked sites (linked selection) focusing on its effects on nearby nucleotides in genomic regions with nonreduced recombination. We argue that these local effects of linkage may account for differences in selection intensity among genes. We also show that even high levels of recombination are unlikely to remove all effects of linked selection, causing a reduction in the polymorphism to divergence ratio (r(pd)) at neutral sites. Because a number of methods employed to estimate the magnitude and frequency of adaptive mutations take reduced r(pd) as evidence of positive selection, ignoring local linkage effects may lead to misleading estimates of the proportion of adaptive substitutions and estimates of positive selection. These biases are caused by employing methods that do not account for local variation in the relative effective population size (N(e)) caused by linked selection.

  8. Y-chromosomal evidence for a limited Greek contribution to the Pathan population of Pakistan.

    Science.gov (United States)

    Firasat, Sadaf; Khaliq, Shagufta; Mohyuddin, Aisha; Papaioannou, Myrto; Tyler-Smith, Chris; Underhill, Peter A; Ayub, Qasim

    2007-01-01

    Three Pakistani populations residing in northern Pakistan, the Burusho, Kalash and Pathan claim descent from Greek soldiers associated with Alexander's invasion of southwest Asia. Earlier studies have excluded a substantial Greek genetic input into these populations, but left open the question of a smaller contribution. We have now typed 90 binary polymorphisms and 16 multiallelic, short-tandem-repeat (STR) loci mapping to the male-specific portion of the human Y chromosome in 952 males, including 77 Greeks in order to re-investigate this question. In pairwise comparisons between the Greeks and the three Pakistani populations using genetic distance measures sensitive to recent events, the lowest distances were observed between the Greeks and the Pathans. Clade E3b1 lineages, which were frequent in the Greeks but not in Pakistan, were nevertheless observed in two Pathan individuals, one of whom shared a 16 Y-STR haplotype with the Greeks. The worldwide distribution of a shortened (9 Y-STR) version of this haplotype, determined from database information, was concentrated in Macedonia and Greece, suggesting an origin there. Although based on only a few unrelated descendants, this provides strong evidence for a European origin for a small proportion of the Pathan Y chromosomes.

  9. Comparing the demographic factors of patient with limited and diffuse type of alopecia areata

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    Mina Daliri

    2010-09-01

    Full Text Available Background: Alopecia areata is a chronic inflammatory disease that involves the hair follicle. Clinically, patients with alopecia areata may have patchy or confluent hair loss on the scalp or body so we conduct a study to compare the demographic aspects of patient with limited and diffuse type of alopecia areata.Materials and Method: We conducted a descriptive-analyzing study in which 306 patient were chosen. The patients were divided into two groups of diffuse and limited Alopecia. Demographic factors including age, gender, disease onset were compared in two groups. Results: Out of 306 patients, 58.8 % were male and 41.2 % were female. 247 patients (80.7% suffered from limited type and 59 patients (19.2% suffered from diffuse type. The mean age of the onset of involvement in limited group was 21.9±12 yr and 15.8±12 yr in diffuse group. The mean duration of involvement in limited group was 18.7 months and 71 months in diffuse group. Conclusion: Diffuse type alopecia areata starts at lower age and has longer duration. Our study results were similar to the others. Like other studies, thyroid disorders and atopic dermatitis are positively correlative to the severity of disease

  10. Inverse approach to estimating larval dispersal reveals limited population connectivity along 700 km of wave-swept open coast.

    Science.gov (United States)

    Hameed, Sarah O; White, J Wilson; Miller, Seth H; Nickols, Kerry J; Morgan, Steven G

    2016-06-29

    Demographic connectivity is fundamental to the persistence and resilience of metapopulations, but our understanding of the link between reproduction and recruitment is notoriously poor in open-coast marine populations. We provide the first evidence of high local retention and limited connectivity among populations spanning 700 km along an open coast in an upwelling system. Using extensive field measurements of fecundity, population size and settlement in concert with a Bayesian inverse modelling approach, we estimated that, on average, Petrolisthes cinctipes larvae disperse only 6.9 km (±25.0 km s.d.) from natal populations, despite spending approximately six weeks in an open-coast system that was once assumed to be broadly dispersive. This estimate differed substantially from our prior dispersal estimate (153.9 km) based on currents and larval duration and behaviour, revealing the importance of employing demographic data in larval dispersal estimates. Based on this estimate, we predict that demographic connectivity occurs predominantly among neighbouring populations less than 30 km apart. Comprehensive studies of larval production, settlement and connectivity are needed to advance an understanding of the ecology and evolution of life in the sea as well as to conserve ecosystems. Our novel approach provides a tractable framework for addressing these questions for species occurring in discrete coastal populations.

  11. Identification and synthetic modeling of factors affecting American black duck populations

    Science.gov (United States)

    Conroy, Michael J.; Miller, Mark W.; Hines, James E.

    2002-01-01

    We reviewed the literature on factors potentially affecting the population status of American black ducks (Anas rupribes). Our review suggests that there is some support for the influence of 4 major, continental-scope factors in limiting or regulating black duck populations: 1) loss in the quantity or quality of breeding habitats; 2) loss in the quantity or quality of wintering habitats; 3) harvest, and 4) interactions (competition, hybridization) with mallards (Anas platyrhychos) during the breeding and/or wintering periods. These factors were used as the basis of an annual life cycle model in which reproduction rates and survival rates were modeled as functions of the above factors, with parameters of the model describing the strength of these relationships. Variation in the model parameter values allows for consideration of scientific uncertainty as to the degree each of these factors may be contributing to declines in black duck populations, and thus allows for the investigation of the possible effects of management (e.g., habitat improvement, harvest reductions) under different assumptions. We then used available, historical data on black duck populations (abundance, annual reproduction rates, and survival rates) and possible driving factors (trends in breeding and wintering habitats, harvest rates, and abundance of mallards) to estimate model parameters. Our estimated reproduction submodel included parameters describing negative density feedback of black ducks, positive influence of breeding habitat, and negative influence of mallard densities; our survival submodel included terms for positive influence of winter habitat on reproduction rates, and negative influences of black duck density (i.e., compensation to harvest mortality). Individual models within each group (reproduction, survival) involved various combinations of these factors, and each was given an information theoretic weight for use in subsequent prediction. The reproduction model with highest

  12. The Factor Structure of ADHD in a General Population of Primary School Children

    Science.gov (United States)

    Ullebo, Anne Karin; Breivik, Kyrre; Gillberg, Christopher; Lundervold, Astri J.; Posserud, Maj-Britt

    2012-01-01

    Objective: To examine whether a bifactor model with a general ADHD factor and domain specific factors of inattention, hyperactivity and impulsivity was supported in a large general population sample of children. We also explored the utility of forming subscales based on the domain-specific factors. Methods: Child mental health questionnaires were…

  13. [Determination of von Willebrand factor multimers in Mexican population].

    Science.gov (United States)

    Hernández-Zamora, Edgar; Zavala-Hernández, Cesar; Viveros-Sandoval, Martha Eva; Ochoa-Rico, Angeles; Martínez-Murillo, Carlos; Reyes-Maldonado, Elba

    2014-01-01

    Antecedentes: la enfermedad de von Willebrand es un padecimiento hereditario en el que la estructura, función y concentración del factor de von Willebrand están alteradas y, en consecuencia, también la interacción plaqueta-factor de von Willebrand-endotelio. En México no hay registros epidemiológicos de la enfermedad, sólo se han efectuado algunos estudios aislados desde el punto de vista clínico y hematológico. Material y métodos: estudio retrospectivo efectuado en 155 mexicanos mestizos, 75 de ellos con diagnóstico presuntivo de enfermedad de von Willebrand, 15 con sospecha de hemofilia A y 65 donadores sanos (testigos). Se realizaron pruebas: básicas de coagulación, especiales y de clasificación: análisis de la composición multimérica. Resultados: 15 pacientes se diagnosticaron con hemofilia A; de los 75 sujetos con sospecha de enfermedad de von Willebrand se diagnosticaron 50 de la manera siguiente: tipo 1 (62%), tipo 2 (22%) [subtipos: 2A (14%), 2B (2%) y 2N (6%)] y tipo 3 (16%). Conclusión: el análisis de los multímeros del factor de von Willebrand es un método que cumple con las características adecuadas para el diagnóstico de la enfermedad de von Willebrand, por lo que es necesario implementar esta metodología para su estudio y mejorar su diagnóstico específico.

  14. Cardiovascular risk factors in a population of Brazilian schoolchildren

    Directory of Open Access Journals (Sweden)

    A.N. Rodrigues

    2006-12-01

    Full Text Available Epidemiological and clinical evidence suggests that a judicious diet, regular physical activity and blood pressure (BP monitoring must start in early childhood to minimize the impact of modifiable cardiovascular risk factors. This study was designed to evaluate BP and metabolic parameters of schoolchildren from Vitória, Espírito Santo State, Brazil, and correlate them with cardiovascular risk factors. The study was conducted on 380 students aged 10-14 years (177 boys, 203 girls enrolled in public schools. Baseline measurements included body mass index, BP and heart rate. The students were submitted to exercise spirometry on a treadmill. VO2max was obtained from exercise testing to voluntary exhaustion. Fasting serum total cholesterol (TC, LDL-C, HDL-C, triglycerides (TG, and glucose were measured. Nine point nine percent of the boys and 11.7% of the girls were hypertensive or had pre-hypertensive levels. There was no significant correlation between VO2max and TC, LDL-C, or TG in prepubertal children, but a slight negative correlation was detected in post-pubertal boys for HDL-C and TG. In addition, children with hypertension (3.4% or pre-hypertensive levels (6.6% also had comorbidity for overweight and blood lipid abnormalities (14% for triglycerides, 44.7% for TC, 25.9% for LDL-C, 52% for low HDL-C. The present study shows for the first time high correlations between prehypertensive blood pressure levels and the cardiovascular risk factors high TC, high LDL-C, low HDL-C in schoolchildren. These are important for the formulation of public health policies and strategies.

  15. REQUIREMENTS TO THE LIMITATION OF POPULATION EXPO-SURE FROM THE NATIRAL IONIZING IRRADIATION SOURCES IN INDUSTRIAL CONDITIONS

    Directory of Open Access Journals (Sweden)

    I. P. Stamat

    2010-01-01

    Full Text Available The paper presents conceptually new requirements to the limitation of population exposure from the natural ionizing irradiation sources in industrial conditions, introduced into Basic Sanitary Rules of Radiation Safety (OSPORB-99/2010. It is shown that, first of all, introduction of these requirements is aimed at the resolution of variety of previously existing serious contradictions in organization of radiation safety control and supervision for the impact of natural ionizing irradiation sources in industry.

  16. Risk factors for falls in the institutionalized elder population

    Directory of Open Access Journals (Sweden)

    Camilo Romero

    2004-12-01

    Full Text Available The objective is to determine the risk factorspredictors of falls in institutionalized elderlypeople. Methodology: Analysis of data from alongitudinal cohort study. Subjects: Institutionalizedelderly volunteers residents of a nursinghome in Arbelaez, Colombia enrolled andfollowed for six months (N= 116; mean age: 78years. Main outcome measures: Falls detected via nurses reports and medical records. Independentvariables: Baseline measures of demographics,medical history, drug intake, depression, mentalstate, visual acuity, orthostatic hypotension,body mass index, cardiovascular state, limbdeformities, limb strength, tone, trophism, rageof motion, Romberg, one leg balance test, GetUp and Go test and timed Get Up and Go test.Evaluation of home facilities by the TESS-NHand SCUEQS scales. Results: Over the six monthfollow-up 36% experienced a fall. All noneinjurious falls. The independent significantpredictors of all falls using logistic regression were female gender, history of dizziness and anabnormal one leg balance test. With coefficientB values of 1.029, 2.024 and 1.712, respectively.Conclusion: The female gender, the history ofdizziness and abnormal one-leg balance testappear to be the main and significant predictorsof falls in institutionalized elderly persons.However, no single factor seems to be accurateenough to be relied on as a sole predictor of fallrisk because so many diverse factors are involvedin falling

  17. Anthropogenic landscape change promotes asymmetric dispersal and limits regional patch occupancy in a spatially structured bird population.

    Science.gov (United States)

    Pavlacky, David C; Possingham, Hugh P; Lowe, Andrew J; Prentis, Peter J; Green, David J; Goldizen, Anne W

    2012-09-01

    1. Local extinctions in habitat patches and asymmetric dispersal between patches are key processes structuring animal populations in heterogeneous environments. Effective landscape conservation requires an understanding of how habitat loss and fragmentation influence demographic processes within populations and movement between populations. 2. We used patch occupancy surveys and molecular data for a rainforest bird, the logrunner (Orthonyx temminckii), to determine (i) the effects of landscape change and patch structure on local extinction; (ii) the asymmetry of emigration and immigration rates; (iii) the relative influence of local and between-population landscapes on asymmetric emigration and immigration; and (iv) the relative contributions of habitat loss and habitat fragmentation to asymmetric emigration and immigration. 3. Whether or not a patch was occupied by logrunners was primarily determined by the isolation of that patch. After controlling for patch isolation, patch occupancy declined in landscapes experiencing high levels of rainforest loss over the last 100 years. Habitat loss and fragmentation over the last century was more important than the current pattern of patch isolation alone, which suggested that immigration from neighbouring patches was unable to prevent local extinction in highly modified landscapes. 4. We discovered that dispersal between logrunner populations is highly asymmetric. Emigration rates were 39% lower when local landscapes were fragmented, but emigration was not limited by the structure of the between-population landscapes. In contrast, immigration was 37% greater when local landscapes were fragmented and was lower when the between-population landscapes were fragmented. Rainforest fragmentation influenced asymmetric dispersal to a greater extent than did rainforest loss, and a 60% reduction in mean patch area was capable of switching a population from being a net exporter to a net importer of dispersing logrunners. 5. The

  18. Premature ovarian failure risk factors in an Iranian population

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    Ghassemzadeh A

    2012-04-01

    Full Text Available Alieh Ghassemzadeh1,2, Laya Farzadi1,2, Elaheh Beyhaghi1,21Women’s Reproductive Health Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; 2Alzahra University Hospital, Department of Obstetrics and Gynecology, Tabriz University of Medical Sciences, Tabriz, IranBackground: The aim of this study was to determine possible correlates of premature ovarian failure (POF in an Iranian population.Methods: In a case-control study, 80 patients with POF were compared with 80 controls enrolled from the same setting during 2007–2008. A food diary was used to assess food consumption habits.Results: Mean age of starting ovarian failure symptoms was 19.3 ± 5.7 years and mean age of menopause was 22.6 ± 6.3 years. Familial coincidence was observed in 16 POF patients versus no one in the control group (P < 0.05. POF patients had lower frequency of both eating red meat and fish when compared with controls (P < 0.001. POF and control subjects consumed similar amounts of dairy products, being 5.3 ± 3.2 times per week in POF and 5.6 ± 2.1 times in the control groups.Conclusion: In this study, an association between POF and lower red meat or fish consumption was found.Keywords: POF, etiology, case-control, nutrition, premature menopause, premature ovarian dysfunction, primary ovarian insufficiency

  19. Estimating multi-factor cumulative watershed effects on fish populations with an individual-based model

    Science.gov (United States)

    Bret C. Harvey; Steven F. Railsback

    2007-01-01

    While the concept of cumulative effects is prominent in legislation governing environmental management, the ability to estimate cumulative effects remains limited. One reason for this limitation is that important natural resources such as fish populations may exhibit complex responses to changes in environmental conditions, particularly to alteration of multiple...

  20. [Cardiovascular risk factors in an Arab and Hispanic working population].

    Science.gov (United States)

    Valdivielso, P; García, A; de Rus, I; Avila, J M; Andrade, R; Escolar, J L; González, P

    1991-07-01

    318 records of male workers, 169 Spanish and 149 Arab were retrospectively studied in 1987 at the "Gabinete de Seguridad e Higiene en el Trabajo" (Council for Safety and Hygiene in the Workplace) in Ceuta in order to prove the hypothesis that 2 different ethnic groups living in the same geographic area have a non-equal distribution of cardiovascular risk factors. The Spanish group showed a higher prevalence in blood hypertension, diabetes, glucose intolerance, obesity and alcohol intake, compared to the Arab group. Smoking and high levels of seric cholesterol were similar in both groups, however, medium levels of seric cholesterol were lower in the Arab group. Family histories of cardiovascular disease were very rare in the latter mentioned group. These observations suggested a major predisposition to ischemic cardiopathy in the Spanish group.

  1. Haitian orphan population and protective factors against caries

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    Madelyn Rea

    2016-04-01

    Full Text Available Objective In Haiti, families were torn apart and children were left orphans after the 2010 earthquake. In the aftermath of this natural disaster many children were relocated to orphanages across the country and adopted internationally. Years later these children find themselves catching up in growth physically, mentally and emotionally after an extremely traumatic event during a crucial time in their health development. Another important marker of development is the primary dentition and the presence of caries.  We report estimates of early childhood caries (ECC frequency, risk factors and quality of health among Haitian children. Methods Medical and dental professionals conducted a descriptive cross sectional study through the Pittsburgh Kids Foundation and their partnership with IDADEE children’s home, EBAC orphanage and New Vision Children’s home. Vital signs were taken and recorded to create a health/growth history for each child. Brief dental screenings were conducted and topical fluoride treatments were administered. Risk factors and quality of health information was obtained from discussions with the caregivers present. The children and caregivers were given oral hygiene education and supplies (i.e. toothbrushes, toothpaste, floss.  Results Physical exams and dental screenings were conducted on the 40 children ages 3-10 years of age living in the IDADEE children’s home. Two children had cavitated teeth. Eight children had teeth that were stained. Four children had evidence of dental trauma. 26 out of the 40 children had otherwise healthy dentition. Conclusion The IDADEE children’s home and New Vision Children’s home have hopes to expand their capacity with new construction scheduled to be finished in 2016. As more children enter these homes action is needed to educate caregivers on ways to identify high-risk children to prevent ECC and ways they can be treated before irreversible damage is done to the developing permanent

  2. Limits on Population III star formation with the most iron-poor stars

    Science.gov (United States)

    de Bennassuti, M.; Salvadori, S.; Schneider, R.; Valiante, R.; Omukai, K.

    2017-02-01

    We study the impact of star-forming minihaloes, and the initial mass function (IMF) of Population III (Pop III) stars, on the Galactic halo metallicity distribution function (MDF) and on the properties of C-enhanced and C-normal stars at [Fe/H] sampling of the Pop III IMF. We find that only when star-forming minihaloes are included the low-Fe tail of the MDF is correctly reproduced, showing a plateau that is built up by C-enhanced metal-poor stars imprinted by primordial faint supernovae. The incomplete sampling of the Pop III IMF in inefficiently star-forming minihaloes (50 per cent level by PISNe are thus extremely rare, corresponding to ≈0.25 per cent of the total stellar population at [Fe/H] < -2, which is consistent with recent observations. The low-Fe tail of the MDF strongly depends on the Pop III IMF shape and mass range. Given the current statistics, we find that a flat Pop III IMF model with mPopIII = [10-300] M⊙ is disfavoured by observations. We present testable predictions for Pop III stars extending down to lower masses, with mPopIII = [0.1-300] M⊙.

  3. Finding confidence limits on population growth rates: bootstrap and analytic methods.

    Science.gov (United States)

    Picard, Nicolas; Chagneau, Pierrette; Mortier, Frédéric; Bar-Hen, Avner

    2009-05-01

    When predicting population dynamics, the value of the prediction is not enough and should be accompanied by a confidence interval that integrates the whole chain of errors, from observations to predictions via the estimates of the parameters of the model. Matrix models are often used to predict the dynamics of age- or size-structured populations. Their parameters are vital rates. This study aims (1) at assessing the impact of the variability of observations on vital rates, and then on model's predictions, and (2) at comparing three methods for computing confidence intervals for values predicted from the models. The first method is the bootstrap. The second method is analytic and approximates the standard error of predictions by their asymptotic variance as the sample size tends to infinity. The third method combines use of the bootstrap to estimate the standard errors of vital rates with the analytical method to then estimate the errors of predictions from the model. Computations are done for an Usher matrix models that predicts the asymptotic (as time goes to infinity) stock recovery rate for three timber species in French Guiana. Little difference is found between the hybrid and the analytic method. Their estimates of bias and standard error converge towards the bootstrap estimates when the error on vital rates becomes small enough, which corresponds in the present case to a number of observations greater than 5000 trees.

  4. Evidence of limited polyandry in a natural population of Aedes aegypti.

    Science.gov (United States)

    Richardson, Joshua B; Jameson, Samuel B; Gloria-Soria, Andrea; Wesson, Dawn M; Powell, Jeffrey

    2015-07-01

    The mosquito Aedes aegypti is a vector of yellow fever, dengue, and chikungunya. Control of the insect is crucial to stop the spread of dengue and chikungunya, so it is critically important to understand its mating behavior. Primarily, based on laboratory behavior, it has long been assumed that Ae. aegypti females mate once in their lifetime. However, multiple inseminations have been observed in semi-field and laboratory settings, and in closely related species. Here, we report the first evidence of polyandry in a natural population of Ae. aegypti. Female Ae. aegypti were captured around the New Orleans, LA, metropolitan area. They were offered a blood meal and allowed to lay eggs, which were reared to the third-instar larval stage. A parentage analysis using four microsatellite loci was performed. Out of 48 families, 3 showed evidence of multiple paternity. An expanded analysis of these three families found that one family group included offspring contributed by three fathers, and the other two included offspring from two fathers. This result establishes that polyandry can occur in a small proportion of Ae. aegypti females in a natural setting. This could complicate future genetic control efforts and has implications for sampling for population genetics. © The American Society of Tropical Medicine and Hygiene.

  5. Population dynamics of sinking phytoplankton in light-limited environments: simulation techniques and critical parameters

    Science.gov (United States)

    Huisman, Jef; Sommeijer, Ben

    2002-10-01

    Phytoplankton use light for photosynthesis, and the light flux decreases with depth. As a result of this simple light dependence, reaction-advection-diffusion models describing the dynamics of phytoplankton species contain an integral over depth. That is, models that simulate phytoplankton dynamics in relation to mixing processes generally have the form of an integro-partial differential equation (integro-PDE). Integro-PDEs are computationally more demanding than standard PDEs. Here, we outline a reliable and efficient technique for numerical simulation of integro-PDEs. The simulation technique is illustrated by several examples on the population dynamics of sinking phytoplankton, using both single-species models and competition models with several phytoplankton species. Our results confirm recent findings that Sverdrup's critical-depth theory breaks down if turbulent mixing is reduced below a critical turbulence. In fact, our results show that suitable conditions for bloom development of sinking phytoplankton depend on a number of critical parameters, including a minimal depth of the thermocline, a maximal depth of the thermocline, a minimal turbulence, and a maximal turbulence. We therefore conclude that models that do not carefully consider the population dynamics of phytoplankton in relation to the turbulence structure of the water column may easily lead to erroneous predictions.

  6. Factors Limiting Adoption of Technologies by Farmers in Catabola Municipality, Angola

    Directory of Open Access Journals (Sweden)

    Rušarová K.

    2016-06-01

    Full Text Available The objective of the paper is to define the factors influencing the adoption of animal traction and/or mechanical-power technology in the conditions of Catabola municipality where hand-tool technology is being used on 99.7% of the area cultivated by small farmers. Primary data collection was conducted in the period July–August 2011; semi-structured questionnaires and focus group discussions were the most frequent methods used. In total, 151 small-scale farmers from 9 villages participated in the survey. Ten factors influencing the dependent variable – level of technology used by farmers in combination with hiring of labour – were defined. The factors were statistically analyzed by ANOVA. The area of cultivated land and the educational level of both parents and children were found to be the factors limiting the process of animal traction or mechanical power adoption by small farmers in the Catabola municipality. In addition, a relatively high rate of child labour was observed. With the exclusion of childless families, 62.7% of small farmer families regularly use children aged 0–14 years for field operations. The results confirm that the factor of hiring extra labour is irrelevant in determining the development in technology use by small farmers in the Catabola municipality.

  7. Fruitful factors: what limits seed production of flowering plants in the alpine?

    Science.gov (United States)

    Straka, Jason R; Starzomski, Brian M

    2015-05-01

    Predicting demographic consequences of climate change for plant communities requires understanding which factors influence seed set, and how climate change may alter those factors. To determine the effects of pollen availability, temperature, and pollinators on seed production in the alpine, we combined pollen-manipulation experiments with measurements of variation in temperature, and abundance and diversity of potential pollinators along a 400-m elevation gradient. We did this for seven dominant species of flowering plants in the Coast Range Mountains, British Columbia, Canada. The number of viable seeds set by plants was influenced by pollen limitation (quantity of pollen received), mate limitation (quality of pollen), temperature, abundance of potential pollinators, seed predation, and combinations of these factors. Early flowering species (n = 3) had higher seed set at high elevation and late-flowering species (n = 4) had higher seed set at low elevation. Degree-days >15 °C were good predictors of seed set, particularly in bee-pollinated species, but had inconsistent effects among species. Seed production in one species, Arnica latifolia, was negatively affected by seed-predators (Tephritidae) at mid elevation, where there were fewer frost-hours during the flowering season. Anemone occidentalis, a fly-pollinated, self-compatible species had high seed set at all elevations, likely due to abundant potential pollinators. Simultaneously measuring multiple factors affecting reproductive success of flowering plants helped identify which factors were most important, providing focus for future studies. Our work suggests that responses of plant communities to climate change may be mediated by flowering time, pollination syndrome, and susceptibility to seed predators.

  8. Population-based Risk Factors for Elevated Alanine Aminotransferase in a South Texas Mexican–American Population

    Science.gov (United States)

    Qu, Hui-Qi; Li, Quan; Grove, Megan L.; Lu, Yang; Pan, Jen-Jung; Rentfro, Anne R.; Bickel, Perry E.; Fallon, Michael B.; Hanis, Craig L.; Boerwinkle, Eric; McCormick, Joseph B.; Fisher-Hoch, Susan P.

    2013-01-01

    Background and Aims Elevated alanine aminotransferase (ALT >40 IU/mL) is a marker of liver injury but provides little insight into etiology. We aimed to identify and stratify risk factors associated with elevated ALT in a randomly selected population with a high prevalence of elevated ALT (39%), obesity (49%) and diabetes (30%). Methods Two machine learning methods, the support vector machine (SVM) and Bayesian logistic regression (BLR), were used to capture risk factors in a community cohort of 1532 adults from the Cameron County Hispanic Cohort (CCHC). A total of 28 predictor variables were used in the prediction models. The recently identified genetic marker rs738409 on the PNPLA3 gene was genotyped using the Sequenom iPLEX assay. Results The four major risk factors for elevated ALT were fasting plasma insulin level and insulin resistance, increased BMI and total body weight, plasma triglycerides and non-HDL cholesterol, and diastolic hypertension. In spite of the highly significant association of rs738409 in females, the role of rs738409 in the prediction model is minimal, compared to other epidemiological risk factors. Age and drug and alcohol consumption were not independent determinants of elevated ALT in this analysis. Conclusions The risk factors most strongly associated with elevated ALT in this population are components of the metabolic syndrome and point to nonalcoholic fatty liver disease (NAFLD). This population-based model identifies the likely cause of liver disease without the requirement of individual pathological diagnosis of liver diseases. Use of such a model can greatly contribute to a population-based approach to prevention of liver disease. PMID:22959976

  9. Factors associated with functional limitations in the daily living activities of Japanese hip osteoarthritis patients.

    Science.gov (United States)

    Kondo, Kyoko; Jingushi, Seiya; Ohfuji, Satoko; Sofue, Muroto; Itoman, Moritoshi; Matsumoto, Tadami; Hamada, Yoshiki; Shindo, Hiroyuki; Takatori, Yoshio; Yamada, Harumoto; Yasunaga, Yuji; Ito, Hiroshi; Mori, Satoshi; Owan, Ichiro; Fujii, Genji; Ohashi, Hirotsugu; Fukushima, Wakaba; Maeda, Akiko; Inui, Miki; Takahashi, Shinji; Hirota, Yoshio

    2016-12-10

    As society ages, there is a vast number of elderly people with locomotive syndrome. In this study, the factors associated with functional limitations in daily living activities evaluated by female hip osteoarthritis (OA) patients were investigated. This study was a cross-sectional study. The subjects were 353 female patients who were newly diagnosed with hip OA at an orthopedic clinic with no history of hip joint surgery. Outcome indices were functional limitations in two daily living activities obtained from a questionnaire completed by the patients: (i) standing up (standing from a crouched position) and (ii) stair-climbing (climbing and/or descending stairs). The odds ratios (ORs) and 95% confidence intervals (CIs) were computed for explanatory variables using the proportional odds model in logistic regression to evaluate their associations with functional limitations. Functional limitations in standing up were associated with heavy weight (third tertile vs. first tertile: 1.91, 1.11-3.27), participation in sports at school (0.62, 0.40-0.98), parity (vs. nullipara: 1.96, 1.08-3.56), old age and OA stage. Associations with functional limitations in stair-climbing were seen with short height (weight, parity, shorter height and bilateral OA were associated with functional limitations in standing up and/or stair-climbing, whereas participation in sports such as club activities in school maintained standing up. © 2016 The Authors. International Journal of Rheumatic Diseases published by Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.

  10. Prevalence and Correlates of Physical Disability and Functional Limitation among Elderly Rural Population in Nigeria

    Directory of Open Access Journals (Sweden)

    I. S. Abdulraheem

    2011-01-01

    Full Text Available Background. The number of people surviving into old age is increasing, and it has now become a global phenomenon. Studies on the prevalence and correlates of physical disability and functional limitation among elderly Nigerians are scanty. Methodology. This is a community-based cross-sectional study conducted in 3 local government areas (LGAs in Nigeria, using a multistage sampling technique. Functional limitations of 1824 elderly persons were tested using Tinetti performance-oriented mobility assessment tool (TPOMAT and self-reported activities of daily living (ADL. ADL disability of ten, six, and five basic items were compared. Results. The prevalence ratios (PRs of physical disability using the ten, six, and five basic ADL items were 28.3 (95% CI 25.2–31. 5, 15.7 (95% CI 13.4–19.8, and 12.1 (95% CI 9.8–15.3, respectively, while functional limitation was 22.5 (95% CI 18.1–24.4. Increased risk of disability was independently associated with female gender PR 3.6 (95% CI 1.5–7.4, advanced age ≥75 years; PR 22.2 (95% CI 14.5, 36.8, arthritis PR 3.7 (95% CI 2.6–4.6, stroke PR 4.8 (95% CI 3.7–7.9 and diabetes PR 6.1 (95% CI 4.3–7.1. Conclusions. The findings from this study are pointers to unmet needs of the elderly disabled Nigerians.

  11. Factors associated with cervical cancer screening in a safety net population

    Science.gov (United States)

    Heberer, Meredith A; Komenaka, Ian K; Nodora, Jesse N; Hsu, Chiu-Hsieh; Gandhi, Sonal G; Welch, Lauren E; Bouton, Marcia E; Aristizabal, Paula; Weiss, Barry D; Martinez, Maria Elena

    2016-01-01

    AIM To identify factors associated with Papanicolaou-smear (Pap-smear) cervical cancer screening rates in a safety net population. METHODS From January 2012 to May 2013, the use of Pap-smear was determined for all patients seen at the breast clinic in a safety net hospital. Health literacy assessment was performed using the validated Newest Vital Sign. The records of patients were reviewed to determine if they had undergone Pap-smears for cervical cancer screening. Sociodemographic information was collected included age, education, monthly income, race/ethnicity, employment, insurance status, and primary care provider of the patient. Logistic regression analysis was then performed to determine factors associated with utilization of Pap-smears. Crude and adjusted odds ratios derived from multivariate logistic regression models were calculated as well as the associated 95%CIs and P-values. RESULTS Overall, 39% had Pap-smears in the prior 15 mo, 1377 consecutive women were seen during the study period and their records were reviewed. Significantly more patients with adequate health literacy underwent Pap-smears as compared to those with limited health literacy (59% vs 34%, P literacy, younger patients, and those with later age of first live birth were more likely to undergo Pap-smears. Patients whose primary care providers were gynecologists were also significantly more likely to have Pap-smears compared to other specialties (P literacy and primary care physician were associated with Pap-smear utilization. Development of interventions to target low health literacy populations could improve cervical cancer screening. PMID:27777883

  12. Limits on the Fill Factor in Organic Photovoltaics: Distinguishing Nongeminate and Geminate Recombination Mechanisms.

    Science.gov (United States)

    Dibb, George F A; Jamieson, Fiona C; Maurano, Andrea; Nelson, Jenny; Durrant, James R

    2013-03-07

    In this Letter, we present transient optoelectronic experimental studies of the recombination processes limiting the fill factor (FF) in three conjugated polymer:fullerene systems, poly(3-hexylthiophene) (P3HT) and two lower-band-gap polymers that exhibit lower FFs poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole) (PCPDTBT) and poly(2,7-(9,9-dioctylfluorene)-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)) (APFO-3). Using transient absorption spectroscopy, charge extraction, and transient photovoltage experiments, we show that the lower FF observed for the PCPDTBT-based device results from enhanced nongeminate recombination even at short circuit, In contrast, we show that for APFO-3 devices, the FF is primarily limited by a voltage-dependent free charge generation, which we assign to a geminate recombination process.

  13. Risk factors for treatment-limiting toxicities in patients starting nevirapine-containing antiretroviral therapy

    DEFF Research Database (Denmark)

    Kesselring, Anouk M; Wit, Ferdinand W; Sabin, Caroline A;

    2009-01-01

    BACKGROUND: This collaboration of seven observational clinical cohorts investigated risk factors for treatment-limiting toxicities in both antiretroviral-naive and experienced patients starting nevirapine-based combination antiretroviral therapy (NVPc). METHODS: Patients starting NVPc after 1...... to treatment-limiting toxicities and/or patient/physician choice (TOXPC, n = 10,186). Patients were classified according to prior antiretroviral treatment experience and CD4 cell count/viral load at start NVPc. Models were stratified by cohort and adjusted for age, sex, nadir CD4 cell count, calendar year...... of starting NVPc and mode of transmission. RESULTS: Median time from starting NVPc to TOXPC and HSR were 162 days [interquartile range (IQR) 31-737] and 30 days (IQR 17-60), respectively. In adjusted Cox analyses, compared to naive patients with a low CD4 cell count, treatment-experienced patients with high...

  14. How to Do It. Impact of Environmental Factors on Populations of Soil Microorganisms.

    Science.gov (United States)

    Robert, Francoise M.

    1990-01-01

    Described are simple experiments designed to demonstrate the effect of some factors of the environment (dryness, temperature, and fungicide application) on the size of some populations of soil microorganisms. Materials, media, techniques, procedures, and results are discussed. (CW)

  15. Obesity, Diabetes, and Other Cardiovascular Risk Factors in Native Populations of South America.

    Science.gov (United States)

    Ingaramo, Roberto A

    2016-01-01

    Cardiovascular disease remains the leading cause of death in both developed and developing countries. In South America, the native population comprises a great number of different ethnic groups. The cardiovascular risk factors observed in these groups have proved similar to and even higher than those found in general non-native populations. Relatively recent epidemiologic information reveals that many native communities have healthy habits with low prevalence of risk factors such as hypertension and diabetes, while their prevalence is higher in those who have kept close contact with non-native populations and have westernized their habits. The differences in the presence of risk factors in these populations have been explained as the result of several interacting factors including genetic to environmental, socioeconomic, and cultural causes.

  16. Factors influencing furbearer populations and harvest on the Kenai National Moose Range, Alaska

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Natural factors have influenced several furbearer populations on the 691,000 ha Kenai National Moose Range wildlife refuge in southcentral Alaska. The 1964...

  17. Limitations of long term stability in a coherent population trapping Cs clock

    CERN Document Server

    Kozlova, Olga; Guérandel, Stéphane; de Clercq, Emeric

    2013-01-01

    Vapor cell atomic clocks exhibit reduced frequency stability for averaging time between about one hundred and a few thousand seconds. Here we report a study on the impact of the main parameters on the mid-to-long term instability of a buffer-gas vapor cell Cs clock, based on coherent population trapping (CPT). The CPT signal is observed on the Cs D1 line transmission, using a double $\\Lambda$ scheme and a Ramsey interrogation technique. The effects on the clock frequency of the magnetic field, the cell temperature, and the laser intensities are reported. We show in particular that the laser intensity shift is temperature dependent. Along with the laser intensity ratio and laser polarization properties, this is one of the most important parameters.

  18. Morphological and microsatellite diversity associated with ecological factors in natural populations of Medicago laciniata Mill. (Fabaceae)

    Indian Academy of Sciences (India)

    Mounawer Badri; Adel Zitoun; Houcine Ilahi; Thierry Huguet; Mohamed Elarbi Aouani

    2008-12-01

    Genetic variability in 10 natural Tunisian populations of Medicago laciniata were analysed using 19 quantitative traits and 12 polymorphic microsatellite loci. A large degree of genetic variability within-populations and among-populations was detected for both quantitative characters and molecular markers. High genetic differentiation among populations for quantitative traits was seen, with $Q_{ST} = 0.47$, and $F_{ST} = 0.47$ for microsatellite markers. Several quantitative traits displayed no statistical difference in the levels of $Q_{ST}$ and $F_{ST}$. Further, significant correlations between quantitative traits and eco-geographical factors suggest that divergence in the traits among populations may track environmental differences. There was no significant correlation between genetic variability at quantitative traits and microsatellite markers within populations. The site-of-origin of eco-geographical factors explain between 18.13% and 23.40% of genetic variance among populations at quantitative traits and microsatellite markers, respectively. The environmental factors that most influence variation in measured traits among populations are assimilated phosphorus (P205) and mean annual rainfall, followed by climate and soil texture, altitude and organic matter. Significant associations between eco-geographical factors and gene diversity, $H_{e}$, were established in five-microsatellite loci suggesting that these simple sequence repeats (SSRs) are not necessarily biologically neutral.

  19. Cardiovascular risk factors in a Mexican middle-class urban population: The Lindavista Study. Baseline data

    OpenAIRE

    Meaney,Alejandra; Ceballos-Reyes, Guillermo; Gutierrez-Salmean,Gabriela; Samaniego-Méndez,Virginia; Vela-Huerta,Agustín; Alcocer, Luis; Zárate-Chavarría,Elisa; Mendoza-Castelán,Emma; Olivares-Corichi,Ivonne; García-Sánchez,Rubén; Martínez-Marroquín,Yolanda; Ramírez-Sánchez, Israel; Meaney, Eduardo

    2013-01-01

    Introduction and objective: The aim of this communication is to describe the cardiovascular risk factors affecting a Mexican urban middle-class population. Methods: A convenience sample of 2602 middle class urban subjects composed the cohort of the Lindavista Study, a prospective study aimed to determine if conventional cardiovascular risks factors have the same prognosis impact as in other populations. For the baseline data, several measurements were done: obesity indexes, smoking, blood pre...

  20. COMPARATIVE STUDY OF RISK FACTORS OF TYPE-II DIABETES IN RURAL AND URBAN POPULATION

    OpenAIRE

    Ch. Kiranmai; Sukhes; Rama Krishna; Preethi; Aruna

    2014-01-01

    : A study of effect of various risk factors on Type–II diabetes in Urban and rural population. Generally Indians seems to have great tendency to develop diabetes mellitus. In addition to this, unhealthy food habits, lack of physical activity, diabetic family history, age, obesity, smoking & alcoholism are the other causes for diabetes mellitus. AIM: To analyze the impact of different risk factors on Type – II diabetes in urban and rural population. METHODS: Total 160 subjects ...

  1. Factors Limiting Centralized Land Circulation in China from the Perspective of Farmers’ Property Right

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    At present,there are many factors limiting large area centralized,rapid development,and moderately large-scale land operation in China.These factors include(i) the existing land utilization system is still at adaptation stage,and it lacks universal agreement of people on large-scale land operation;(ii) farmers’ dependence on land is great;(iii) it is difficult to transfer surplus labor;(iv) there is no positive connection between promotion of moderately large-scale land operation and realization of increase of farmers’ income;(v) it remains to be proved whether large-scale operation can become a stable rural occupation and whether big farming households can grow to professional farmers;(vi) large-scale land operation in rural areas may lead to waste of resources;(vii) the promotion of large-scale land operation may cause other social contradictions.

  2. COMPARATIVE STUDY OF RISK FACTORS OF TYPE-II DIABETES IN RURAL AND URBAN POPULATION

    Directory of Open Access Journals (Sweden)

    Ch. Kiranmai

    2014-08-01

    Full Text Available : A study of effect of various risk factors on Type–II diabetes in Urban and rural population. Generally Indians seems to have great tendency to develop diabetes mellitus. In addition to this, unhealthy food habits, lack of physical activity, diabetic family history, age, obesity, smoking & alcoholism are the other causes for diabetes mellitus. AIM: To analyze the impact of different risk factors on Type – II diabetes in urban and rural population. METHODS: Total 160 subjects of urban and rural population were included in this study and their detailed histories were taken by the questionnaire. In this study we compared the blood glucose levels, unhealthy food habits, lack of physical activity, age, obesity, smoking & alcoholism in urban and rural population. RESULT: The study showed that the blood glucose levels, unhealthy food habits, lack of physical activity, diabetic family history, age, obesity, smoking & alcoholism were found higher in urban than in rural population. CONCLUSION: The results showed that the fond of Type – II diabetes is very less in rural population when compared to urban population. This is because of, the rural population had more physical activity, intake of moderate calorie food, less diabetic family history and less obese. So, these factors help to overcome the increased effect of age, smoking and alcoholism on Type – II diabetes in rural population.

  3. ESTIMATING VITICULTURAL FAVORABILITY OF COTNARI VINEYARD AREA AND IDENTIFYING LIMITING FACTORS

    Directory of Open Access Journals (Sweden)

    Cristina Chiriac

    2012-12-01

    Full Text Available For estimating the favorability of agricultural lands for vine in Cotnari vineyard area, we used 16 indicators provided in the Methodology of Soil Survey (Second part and third part - 1986. To determine the average coefficient of evaluation, respectively the class of favorability for the vine in Cotnari Vineyard, we calculated the notes of evaluation for 10 administrative units from Cotnari Vineyard: Flămânzi, Frumuşica, Deleni, Hârlău, Scobinţi, Cepleniţa, Cotnari, Cucuteni, Todireşti, Târgu Frumos. For each administrative unit were selected the territorial units of soil (U.S. within Cotnari Vineyard, from which we extracted only the ecological homogeneous territories (TEO's that are planted with vine. Among the limiting factors identified in Cotnari Vineyard we mention the geomorphologic factor (slope, landslides, the pedological factor (gleying, stagnogleying,salinization/alkalization, texture, reaction, humus content, edaphic volume and the hydrological factor (groundwater depth, excess moisture in surface, flooding by overflow.

  4. Modifiable etiological factors and the burden of stroke from the Rotterdam study: a population-based cohort study.

    Directory of Open Access Journals (Sweden)

    Michiel J Bos

    2014-04-01

    Full Text Available BACKGROUND: Stroke prevention requires effective treatment of its causes. Many etiological factors for stroke have been identified, but the potential gain of effective intervention on these factors in terms of numbers of actually prevented strokes remains unclear because of the lack of data from cohort studies. We assessed the impact of currently known potentially modifiable etiological factors on the occurrence of stroke. METHODS AND FINDINGS: This population-based cohort study was based on 6,844 participants of the Rotterdam Study who were aged ≥55 y and free from stroke at baseline (1990-1993. We computed population attributable risks (PARs for individual risk factors and for risk factors in combination to estimate the proportion of strokes that could theoretically be prevented by the elimination of etiological factors from the population. The mean age at baseline was 69.4 y (standard deviation 6.3 y. During follow-up (mean follow-up 12.9 y, standard deviation 6.3 y, 1,020 strokes occurred. The age- and sex-adjusted combined PAR of prehypertension/hypertension, smoking, diabetes mellitus, atrial fibrillation, coronary disease, and overweight/obesity was 0.51 (95% CI 0.41-0.62 for any stroke; hypertension and smoking were the most important etiological factors. C-reactive protein, fruit and vegetable consumption, and carotid intima-media thickness in combination raised the total PAR by 0.06. The PAR was 0.55 (95% CI 0.41-0.68 for ischemic stroke and 0.70 (95% CI 0.45-0.87 for hemorrhagic stroke. The main limitations of our study are that our study population comprises almost exclusively Caucasians who live in a middle and high income area, and that risk factor awareness is higher in a study cohort than in the general population. CONCLUSIONS: About half of all strokes are attributable to established causal and modifiable factors. This finding encourages not only intervention on established etiological factors, but also further study of less

  5. Global importation and population risk factors for measles in New Zealand: a case study for highly immunized populations.

    Science.gov (United States)

    Hayman, D T S; Marshall, J C; French, N P; Carpenter, T E; Roberts, M G; Kiedrzynski, T

    2017-07-01

    As endemic measles is eliminated through immunization, countries must determine the risk factors for the importation of measles into highly immunized populations to target control measures. Despite eliminating endemic measles, New Zealand suffers from outbreaks after introductions from abroad, enabling us to use it as a model for measles introduction risk. We used a generalized linear model to analyze risk factors for 1137 measles cases from 2007 to June 2014, provide estimates of national immunity levels, and model measles importation risk. People of European ethnicity made up the majority of measles cases. Age is a positive risk factor, particularly 0-2-year-olds and 5-17-year-old Europeans, along with increased wealth. Pacific islanders were also at greater risk, but due to 0-2-year-old cases. Despite recent high measles, mumps, and rubella vaccine immunization coverage, overall population immunity against measles remains ~90% and is lower in people born between 1982 and 2005. Greatest measles importation risk is during December, and countries predicted to be sources have historical connections and highest travel rates (Australia and UK), followed by Asian countries with high travel rates and higher measles incidences. Our results suggest measles importation due to travel is seeding measles outbreaks, and immunization levels are insufficient to continue to prevent outbreaks because of heterogeneous immunity in the population, leaving particular age groups at risk.

  6. Reverse Epidemiology of Traditional Cardiovascular Risk Factors in the Geriatric Population

    Science.gov (United States)

    Ahmadi, Seyed-Foad; Streja, Elani; Zahmatkesh, Golara; Streja, Dan; Kashyap, Moti; Moradi, Hamid; Molnar, Miklos Z.; Reddy, Uttam; Amin, Alpesh N.; Kovesdy, Csaba P.; Kalantar-Zadeh, Kamyar

    2015-01-01

    Traditional risk factors of cardiovascular death in the general population, including body mass index (BMI), serum cholesterol, and blood pressure (BP), are also found to relate to outcomes in the geriatric population, but in an opposite direction. Some degrees of elevated BMI, serum cholesterols, and BP are reportedly associated with lower – instead of higher – risk of death among the elderly. This phenomenon is termed “reverse epidemiology” or “risk factor paradox” (such as obesity paradox) and is also observed in a variety of chronic disease states such as end-stage renal disease requiring dialysis, chronic heart failure, rheumatoid arthritis, and AIDS. Several possible causes are hypothesized to explain this risk factor reversal: competing short-term and long-term killers, improved hemodynamic stability in the obese, adipokine protection against tumor necrosis factor-α, lipoprotein protection against endotoxins, and lipophilic toxin sequestration by the adipose tissue. It is possible that the current thresholds for intervention and goals levels for such traditional risk factors as BMI, serum cholesterol, and BP derived based on younger populations do not apply to the elderly, and that new levels for such risk factors should be developed for the elderly population. Reverse epidemiology of conventional cardiovascular risk factors may have a bearing on the management of the geriatric population, thus it deserves further attention. PMID:26363864

  7. Chronic airflow limitation in a rural Indian population: etiology and relationship to body mass index

    Directory of Open Access Journals (Sweden)

    Chakrabarti B

    2011-10-01

    Full Text Available Biswajit Chakrabarti1, Sabita Purkait2, Punyabrata Gun2, Vicky C Moore3, Samadrita Choudhuri4, MJ Zaman5,6, Christopher J Warburton1, Peter MA Calverley7, Rahul Mukherjee3 1Aintree Chest Centre, University Hospital Aintree, Liverpool, UK; 2Moitri Swasthya Kendra, Shramajibi Swasthya Udyog, Chengail, West Bengal, India; 3Department of Respiratory Medicine and Physiology, Birmingham Heartlands Hospital, Birmingham, UK; 4National Medical College, Birgunj, Nepal; 5Department of Epidemiology and Public Health, University College, London, UK; 6The George Institute for Global Health, Sydney, Australia; 7Clinical Sciences Centre, University Hospital Aintree, Liverpool, UK Purpose: Respiratory conditions remain a source of morbidity globally. As such, this study aimed to explore factors associated with the development of airflow obstruction (AFO in a rural Indian setting and, using spirometry, study whether underweight is linked to AFO. Methods: Patients > 35 years old attending a rural clinic in West Bengal, India, took a structured questionnaire, had their body mass index (BMI measured, and had spirometry performed by an ancillary health care worker. Results: In total, 416 patients completed the study; spirometry was acceptable for analysis of forced expiratory volume in 1 second in 286 cases (69%; 16% were noted to exhibit AFO. Factors associated with AFO were: increasing age (95% confidence interval (CI 0.004–0.011; P = 0.005, smoking history (95% CI 0.07–0.174; P = 0.006, male gender (95% CI 0.19–0.47; P = 0.012, reduced BMI (95% CI 0.19–0.65; P = 0.02, and occupation (95% CI 0.12–0.84; P = 0.08. The mean BMI in males who currently smoked (n = 60; 19.29 kg/m2; standard deviation [SD] 3.46 was significantly lower than in male never smokers (n = 33; 21.15 kg/m2 SD 3.38; P < 0.001. AFO was observed in 27% of subjects with a BMI <18.5 kg/m2, falling to 13% with a BMI ≥18.5 kg/m2 (P = 0.013. AFO was observed in 11% of housewives, 22% of farm

  8. The natural conditions as a limiting factor for the development of Serbian-Macedonian border area

    Directory of Open Access Journals (Sweden)

    Dragićević Slavoljub

    2010-01-01

    Full Text Available Natural conditions of certain area imply to the complex influence of various elements of the environment (surface, relief, climate, water, vegetation type and man, and knowledge of their recent state represents basis of an integrated approach in the land use planning. Analysis of natural conditions and processes in the Serbian-Macedonian border area is usually done through the valorization of natural potentials, but aspect of their limiting influence on the development of this territory - natural hazards assessment has remained unresolved. Degree of natural hazards vulnerability of a certain territory is an important factor in land use planning, because it represents a threat to the undisturbed development of a certain teritory. The basic idea of this paper is to provide multi-hazard assessment and the integral map of areas vulnerable to various types of natural hazards in Serbian-Macedonian border area. In this way seclusion of areas where natural conditions can represent the limiting factor for the development of the analyzed territory shall be performed.

  9. Limiting factors for nomadic pastoralism in Mongolian steppe: A hydrologic perspective

    Science.gov (United States)

    Sugita, Michiaki; Yoshizawa, Shintaroh; Byambakhuu, Ishgaldan

    2015-05-01

    In this study, limiting factors for continuing nomadic pastoralism in steppe areas were studied based on a hydrologic perspective. Two small watersheds in central Mongolia were selected for an assessment of water balance and hydrologic processes. We determined that the majority of annual precipitation, ∼88-96 mm, was lost by evaporation (82%) while only a small proportion went to groundwater discharge, surface runoff, and groundwater consumption by nomadic activities. The soil column was found to absorb large fluctuations in precipitation although its connection to groundwater was very weak. Groundwater recharge was, therefore, very small and occurred only rarely during heavy rainfall events in valley bottoms. However, current water storage in shallow groundwater was determined to be quite sufficient for continuing nomadic pastoralism when compared to the drinking water requirements of livestock. The main limiting factors identified were a temporal lack of feed to animals due to a loss of aboveground biomass resulting from soil moisture shortages during drought conditions, and a decline in the number and maintenance level of the traditional well network that, due to access to shallow groundwater, has allowed herders to migrate to areas with better conditions in remote Mongolian steppe.

  10. Highly differentiated populations of the freshwater diatom Sellaphora capitata suggest limited dispersal and opportunities for allopatric speciation.

    Science.gov (United States)

    Evans, Katharine M; Chepurnov, Victor A; Sluiman, Hans J; Thomas, Sindu J; Spears, Bryan M; Mann, David G

    2009-08-01

    The diversities and distributions of diatoms are much more complex than was ever imagined. To understand the underlying mechanisms, research must focus on evolutionary processes occurring at a population level and employ sufficiently informative molecular markers. Using ten microsatellites and ITS rDNA sequence data, we investigated the genetic structure of populations of the benthic freshwater diatom Sellaphora capitata (until 2004 a cryptic entity within the S. pupula agg. species complex). This is the first time that microsatellites have been used to investigate the genetic structure of any freshwater or benthic microalga. Using an integrated approach (morphology, DNA barcoding and specificity of the microsatellite primers), we verified the identity of 70 S. capitata isolates obtained from lakes in the UK, Belgium and Australia. Standardized F'(ST) values were very high (>0.4) and in Bayesian analyses, isolates clustered according to their country of origin, with limited evidence of admixture. However, selected isolates from all countries were sexually compatible, a result consistent with limited ITS divergence. Considering the apparent absence of desiccation-resistant resting stages in most diatoms, we conclude that such levels of differentiation are likely to be a consequence of limited dispersal. With restricted dispersal, previously unacknowledged opportunities for allopatric speciation exist, which may help to explain the huge extant diversity of diatoms.

  11. Psychological consequences of screening for cardiovascular risk factors in an un-selected general population

    DEFF Research Database (Denmark)

    Løkkegaard, Thomas; Andersen, John S; Jacobsen, Rikke K

    2015-01-01

    screening in healthy adults leads to mental distress in the study population, independent of participation. Methods: The Inter99 study (1999 – 2006) was a randomised intervention in the general population, aiming to prevent IHD by a healthier lifestyle. We included the whole study population, independent......Background: Concerns that general health checks, including screening for risk factors to ischemic heart disease (IHD),have negative psychological consequences seem widely unfounded; however, previous studies are only based on selfreports from participants. Aim: To investigate if risk factor...

  12. Effects of geographic scale on population factors in acute disease diffusion analysis

    Institute of Scientific and Technical Information of China (English)

    Poh-Chin Lai; Chun Bong Chow; Ho Ting Wong; Kim Hung Kwong; Shao Haei Liu; Wah Kun Tong; Wai Keung Cheung; Wing Leung Wong; Yat Wah Kwan

    2015-01-01

    Objective:To explore socio-demographic data of the population as proxies for risk factors in disease transmission modeling at different geographic scales. Methods: Patient records of confirmed H1N1 influenza were analyzed at three geographic aggregation levels together with population census statistics. Results:The study confirmed that four population factors were related in different degrees to disease incidence, but the results varied according to spatial resolution. The degree of association actually decreased when data of a higher spatial resolution were used. Conclusions:We concluded that variables at suitable spatial resolution may be useful in improving the predictive powers of models for disease outbreaks.

  13. Prevalence of Diabetes and Associated Factors in the Uyghur and Han Population in Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Haiying Gong

    2015-10-01

    Full Text Available Objective: To estimate the prevalence of diabetes and identify risk factors in the Uyghur and Han population in Xinjiang, China. Methods: A cross-sectional study in urban and rural areas in Xinjiang, including 2863 members of the Uyghur population and 3060 of the Han population aged 20 to 80 years, was conducted from June 2013 to August 2013. Data on fasting plasma glucose (FPG and personal history of diabetes were used to estimate the prevalence of diabetes. Data on demographic characteristics, lifestyle risk factors, and lipid profiles were collected to identify risks factors using the multivariate logistic regression model. Results: In urban areas, the age- and gender-standardized prevalence of diabetes was 8.21%, and the age- and gender-standardized prevalence of diabetes was higher in the Uyghur population (10.47% than in the Han population (7.36%. In rural areas, the age- and gender-standardized prevalence of diabetes was 6.08%, and it did not differ significantly between the Uyghur population (5.71% and the Han population (6.59%. The results of the multivariate logistic regression analysis showed that older age, obesity, high triglycerides (TG, and hypertension were all associated with an increased risk of diabetes in the Uyghur and Han population. Urban residence and low high-density lipoprotein cholesterol (HDL-C were associated with an increased risk of diabetes in the Uyghur population. Being an ex-drinker was associated with an increased risk of diabetes and heavy physical activity was associated with a decreased risk of diabetes in the Han population. Conclusions: Our study indicates that diabetes is more prevalent in the Uyghur population compared with the Han population in urban areas. Strategies aimed at the prevention of diabetes require ethnic targeting.

  14. Limits on the Ultra-bright Fast Radio Burst Population from the CHIME Pathfinder

    Science.gov (United States)

    Amiri, M.; Bandura, K.; Berger, P.; Bond, J. R.; Cliche, J. F.; Connor, L.; Deng, M.; Denman, N.; Dobbs, M.; Domagalski, R. S.; Fandino, M.; Gilbert, A. J.; Good, D. C.; Halpern, M.; Hanna, D.; Hincks, A. D.; Hinshaw, G.; Höfer, C.; Hsyu, G.; Klages, P.; Landecker, T. L.; Masui, K.; Mena-Parra, J.; Newburgh, L. B.; Oppermann, N.; Pen, U. L.; Peterson, J. B.; Pinsonneault-Marotte, T.; Renard, A.; Shaw, J. R.; Siegel, S. R.; Sigurdson, K.; Smith, K.; Storer, E.; Tretyakov, I.; Vanderlinde, K.; Wiebe, D. V.; Scientific Collaboration20, CHIME

    2017-08-01

    We present results from a new incoherent-beam fast radio burst (FRB) search on the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder. Its large instantaneous field of view (FoV) and relative thermal insensitivity allow us to probe the ultra-bright tail of the FRB distribution, and to test a recent claim that this distribution’s slope, α \\equiv -\\tfrac{\\partial {log}N}{\\partial {log}S}, is quite small. A 256-input incoherent beamformer was deployed on the CHIME Pathfinder for this purpose. If the FRB distribution were described by a single power law with α = 0.7, we would expect an FRB detection every few days, making this the fastest survey on the sky at present. We collected 1268 hr of data, amounting to one of the largest exposures of any FRB survey, with over 2.4 × 105 deg2 hr. Having seen no bursts, we have constrained the rate of extremely bright events to <13 sky-1 day-1 above ˜ 220\\sqrt{(τ /{ms})} {Jy} {ms} for τ between 1.3 and 100 ms, at 400-800 MHz. The non-detection also allows us to rule out α ≲ 0.9 with 95% confidence, after marginalizing over uncertainties in the GBT rate at 700-900 MHz, though we show that for a cosmological population and a large dynamic range in flux density, α is brightness dependent. Since FRBs now extend to large enough distances that non-Euclidean effects are significant, there is still expected to be a dearth of faint events and relative excess of bright events. Nevertheless we have constrained the allowed number of ultra-intense FRBs. While this does not have significant implications for deeper, large-FoV surveys like full CHIME and APERTIF, it does have important consequences for other wide-field, small dish experiments.

  15. Measuring Disability in Population Based Surveys: The Interrelationship between Clinical Impairments and Reported Functional Limitations in Cameroon and India

    Science.gov (United States)

    2016-01-01

    Purpose To investigate the relationship between two distinct measures of disability: self-reported functional limitations and objectively-screened clinical impairments. Methods We undertook an all age population-based survey of disability in two areas: North-West Cameroon (August/October 2013) and Telangana State, India (Feb/April 2014). Participants were selected for inclusion via two-stage cluster randomised sampling (probability proportionate to size cluster selection and compact segment sampling within clusters). Disability was defined as the presence of self-reported functional limitations across eight domains, or presence of moderate or greater clinical impairments. Clinical impairment screening comprised of visual acuity testing for vision impairment, pure tone audiometry for hearing impairment, musculoskeletal functioning assessment for musculoskeletal impairment, reported seizure history for epilepsy and reported symptoms of clinical depression (depression adults only). Information was collected using structured questionnaires, observations and examinations. Results Self-reported disability prevalence was 5.9% (95% CI 4.7–7.4) and 7.5% (5.9–9.4) in Cameroon and India respectively. The prevalence of moderate or greater clinical impairments in the same populations were 8.4% (7.5–9.4) in Cameroon and 10.5% (9.4–11.7) in India. Overall disability prevalence (self-report and/or screened positive to a moderate or greater clinical impairment) was 10.5% in Cameroon and 12.2% in India, with limited overlap between the sub-populations identified using the two types of tools. 33% of participants in Cameroon identified to have a disability, and 45% in India, both reported functional limitations and screened positive to objectively-screened impairments, whilst the remainder were identified via one or other tool only. A large proportion of people with moderate or severe clinical impairments did not self-report functional difficulties despite reporting

  16. Measuring Disability in Population Based Surveys: The Interrelationship between Clinical Impairments and Reported Functional Limitations in Cameroon and India.

    Science.gov (United States)

    Mactaggart, Islay; Kuper, Hannah; Murthy, G V S; Oye, Joseph; Polack, Sarah

    2016-01-01

    To investigate the relationship between two distinct measures of disability: self-reported functional limitations and objectively-screened clinical impairments. We undertook an all age population-based survey of disability in two areas: North-West Cameroon (August/October 2013) and Telangana State, India (Feb/April 2014). Participants were selected for inclusion via two-stage cluster randomised sampling (probability proportionate to size cluster selection and compact segment sampling within clusters). Disability was defined as the presence of self-reported functional limitations across eight domains, or presence of moderate or greater clinical impairments. Clinical impairment screening comprised of visual acuity testing for vision impairment, pure tone audiometry for hearing impairment, musculoskeletal functioning assessment for musculoskeletal impairment, reported seizure history for epilepsy and reported symptoms of clinical depression (depression adults only). Information was collected using structured questionnaires, observations and examinations. Self-reported disability prevalence was 5.9% (95% CI 4.7-7.4) and 7.5% (5.9-9.4) in Cameroon and India respectively. The prevalence of moderate or greater clinical impairments in the same populations were 8.4% (7.5-9.4) in Cameroon and 10.5% (9.4-11.7) in India. Overall disability prevalence (self-report and/or screened positive to a moderate or greater clinical impairment) was 10.5% in Cameroon and 12.2% in India, with limited overlap between the sub-populations identified using the two types of tools. 33% of participants in Cameroon identified to have a disability, and 45% in India, both reported functional limitations and screened positive to objectively-screened impairments, whilst the remainder were identified via one or other tool only. A large proportion of people with moderate or severe clinical impairments did not self-report functional difficulties despite reporting participation restrictions. Tools to

  17. Investigating Limiting Factors in Stretchable All-Carbon Transistors for Reliable Stretchable Electronics.

    Science.gov (United States)

    Chortos, Alex; Zhu, Chenxin; Oh, Jin Young; Yan, Xuzhou; Pochorovski, Igor; To, John W-F; Liu, Nan; Kraft, Ulrike; Murmann, Boris; Bao, Zhenan

    2017-08-22

    Stretchable form factors enable electronic devices to conform to irregular 3D structures, including soft and moving entities. Intrinsically stretchable devices have potential advantages of high surface coverage of active devices, improved durability, and reduced processing costs. This work describes intrinsically stretchable transistors composed of single-walled carbon nanotube (SWNT) electrodes and semiconductors and a dielectric that consists of a nonpolar elastomer. The use of a nonpolar elastomer dielectric enabled hysteresis-free device characteristics. Compared to devices on SiO2 dielectrics, stretchable devices with nonpolar dielectrics showed lower mobility in ambient conditions because of the absence of doping from water. The effect of a SWNT band gap on device characteristics was investigated by using different SWNT sources as the semiconductor. Large-band-gap SWNTs exhibited trap-limited behavior caused by the low capacitance of the dielectric. In contrast, high-current devices based on SWNTs with smaller band gaps were more limited by contact resistance. Of the tested SWNT sources, SWNTs with a maximum diameter of 1.5 nm performed the best, with a mobility of 15.4 cm(2)/Vs and an on/off ratio >10(3) for stretchable transistors. Large-band-gap devices showed increased sensitivity to strain because of a pronounced dependence on the dielectric thickness, whereas contact-limited devices showed substantially less strain dependence.

  18. Rate limiting factors in trichloroethylene co-metabolic degradation by phenol-grown aerobic granules.

    Science.gov (United States)

    Zhang, Yi; Tay, Joo Hwa

    2014-04-01

    The potential of aerobic granular sludge in co-metabolic removal of recalcitrant substances was evaluated using trichloroethylene (TCE) as the model compound. Aerobic granules cultivated in a sequencing batch reactor with phenol as the growth substrate exhibited TCE and phenol degradation activities lower than previously reported values. Depletion of reducing energy and diffusion limitation within the granules were investigated as the possible rate limiting factors. Sodium formate and citrate were supplied to the granules in batch studies as external electron sources. No significant enhancing effect was observed on the instant TCE transformation rates, but 10 mM formate could improve the ultimate transformation capacity by 26 %. Possible diffusion barrier was studied by sieving the biomass into five size fractions, and determining their specific TCE and phenol degradation rates and capacities. Biomass in the larger size fractions generally showed lower activities. Large granules of >700 μm diameter exhibited only 22 % of the flocs' TCE transformation capacity and 35 % of its phenol dependent SOUR, indicating the possible occurrence of diffusion limitation in larger biomass. However, the highest specific TCE transformation rate was observed with the fraction that mostly consisted of small granules (150-300 μm), suggesting an optimal size range while applying aerobic granules in TCE co-metabolic removal.

  19. Genetic shift in local rice populations during rice breeding programs in the northern limit of rice cultivation in the world.

    Science.gov (United States)

    Fujino, Kenji; Obara, Mari; Ikegaya, Tomohito; Tamura, Kenichi

    2015-09-01

    The rapid accumulation of pre-existing mutations may play major roles in the establishment and shaping of adaptability for local regions in current rice breeding programs. The cultivated rice, Oryza sativa L., which originated from tropical regions, is now grown worldwide due to the concerted efforts of breeding programs. However, the process of establishing local populations and their origins remain unclear. In the present study, we characterized DNA polymorphisms in the rice variety KITAAKE from Hokkaido, one of the northern limits of rice cultivation in the world. Indel polymorphisms were attributed to transposable element-like insertions, tandem duplications, and non-TE deletions as the original mutation events in the NIPPONBARE and KITAAKE genomes. The allele frequencies of the KITAAKE alleles markedly shifted to the current variety types among the local population from Hokkaido in the last two decades. The KITAAKE alleles widely distributed throughout wild rice and cultivated rice over the world. These have accumulated in the local population from Hokkaido via Japanese landraces as the ancestral population of Hokkaido. These results strongly suggested that combinations of pre-existing mutations played a role in the establishment of adaptability. This approach using the re-sequencing of local varieties in unique environmental conditions will be useful as a genetic resource in plant breeding programs in local regions.

  20. Factors and Mechanisms for Pharmacokinetic Differences between Pediatric Population and Adults

    Directory of Open Access Journals (Sweden)

    Jose T. Ramos

    2011-02-01

    Full Text Available Many physiologic differences between children and adults may result in age-related changes in pharmacokinetics and pharmacodynamics. Factors such as gastric pH and emptying time, intestinal transit time, immaturity of secretion and activity of bile and pancreatic fluid among other factors determine the oral bioavailability of pediatric and adult populations. Anatomical, physiological and biochemical characteristics in children also affect the bioavailability of other routes of administration. Key factors explaining differences in drug distribution between the pediatric population and adults are membrane permeability, plasma protein binding and total body water. As far as drug metabolism is concerned, important differences have been found in the pediatric population compared with adults both for phase I and phase II metabolic enzymes. Immaturity of glomerular filtration, renal tubular secretion and tubular reabsorption at birth and their maturation determine the different excretion of drugs in the pediatric population compared to adults.

  1. Dietary and lifestyle risk factors for noncommunicable disease among the Mongolian population

    DEFF Research Database (Denmark)

    Bolormaa, Norov; Narantuya, Luvsanbazar; de Courten, Maximilian

    2008-01-01

    The overall aim is to determine the prevalence of lifestyle related risk factors for noncommunicable disease (NCD) in Mongolia. The prevalence of NCD risk factors was survey in among 15-64 years old population, using the World Health Organization (WHO) STEPwise approach for NCD surveillance....... The risk factor survey instrument was designed within the concepts of NCD surveillance taking in to account local needs and resources. The average fruit and vegetables intake has been reported as being 3.2% (+/- 0.004 CI) serving sizes per day in the surveyed population. The overall proportion of current...... daily smokers was 24.2% (+/- 0.1 CI) and 66.5% (+/- 0.1 CI) of surveyed population were used alcohol beverages over the past 12 months. About 23.1% (+/- 0.1 CI) of the surveyed population engaged only in low levels of physical activity or have had physical inactivity and 22.2% (+/- 0.05 CI) had elevated...

  2. Incidence, Risk Factors, and Outcomes for Enterococcus spp. Blood Stream Infections: A Population-Based Study

    Directory of Open Access Journals (Sweden)

    E.O. Billington

    2014-09-01

    Conclusions: This is the second population-based study to assess the risk factors for enterococcal BSI and compare the characteristics of infection with E. faecalis and E. faecium. Results suggest that BSI with E. faecalis and E. faecium should be regarded as two clinically different entities with unique sets of risk factors and microbiologic characteristics.

  3. An Investigation of Cardiovascular Disease Risk Factors in an Adolescent Population.

    Science.gov (United States)

    Wolfgang, James; Dennison, Darwin

    1982-01-01

    A study was conducted to analyze high school students' self-reports and to determine biomedical cardiovascular disease risk factors in an adolescent population. Factors evaluated included smoking frequency, dietary fat intake, saturated fat intake, and cholesterol/high density lipoprotein ratio. (JN)

  4. Natural Populations of Drosophila melanogaster Reveal Features of an Uncharacterized Circadian Property: The Lower Temperature Limit of Rhythmicity.

    Science.gov (United States)

    Maguire, Sarah E; Schmidt, Paul S; Sehgal, Amita

    2014-06-01

    Most cyclic biological processes are under control of a circadian molecular timing system that synchronizes these phenomena to the 24-h day. One generic property of circadian-controlled processes is that they operate within a specific temperature range, below which the manifestation of rhythm ceases. Little is known about the evolutionary relevance of the lower temperature limit of rhythmicity or about the mechanism underlying the loss of overt circadian behavior below this lower limit, especially in one model organism of chronobiology, Drosophila melanogaster. Natural populations of Drosophila are evolving under divergent selection pressures and so provide a source of diversity necessary to address these issues. Using lines derived from African populations, we find that there is natural variation in the expression of rhythmic behavior under low-temperature conditions. We found evidence that this variability is evolutionarily relevant at extremely low temperature (12 °C) because high-altitude populations exhibit selection for locally adapted genomes that contribute to rhythmic behavior. Lines resistant to 15 °C show an additional layer of diversity in their response to temperature extremes because some lines are resistant to low temperature (15 °C) only, whereas others are cross-resistant to high and low temperature (15 °C and 30 °C). Genetic analysis of one cold-resistant circadian line at 15 °C reveals that the phenotype maps to the X-chromosome but not to the core clock genes, per and sgg. Analysis of the central clock cells of this line reveals that maintenance of rhythm is associated with robust clock function, which is compromised in a standard laboratory strain. These data indicate that the cold-resistant circadian phenotype is clock based. This study highlights the importance of using natural populations to inform us of the basic features of circadian traits, especially those that might be under temperature-based selection.

  5. Limited phenotypic plasticity in range-edge populations: a comparison of co-occurring populations of two Agrimonia species with different geographical distributions.

    Science.gov (United States)

    Mägi, Maris; Semchenko, Marina; Kalamees, Reïn; Zobel, Kristjan

    2011-01-01

    Increased importance of genetic drift and selection for stress resistance have been predicted to lead to a reduction in the degree of phenotypic plasticity in populations at margins of a species' geographical range, relative to those in the centre. We examined the effect of population positioning within the species range on degree of active morphological plasticity to vegetation shade. Importantly, we discriminated between active, size-independent morphological adjustments in response to shade and passive changes in morphology caused by the dependence of morphological traits on plant size, as only the former are considered to be adaptive. Two closely related and ecologically similar Agrimonia species were examined in the same geographical location, where one species reaches the edge of its distribution (Agrimonia pilosa) and the other does not (A. eupatoria). Plasticity to light availability is likely to be advantageous for both species as they occupy habitats with variable light conditions. However, we hypothesised that high levels of environmental stress should lead to reduced active plasticity in marginal compared with more central populations. Agrimonia eupatoria exhibited active adjustments in leaf morphology in response to tree shade, and in elongation of stems and inflorescences in response to herbaceous shade. In contrast, A. pilosa exhibited very limited active plasticity. High active plasticity allowed A. eupatoria to retain constant shoot growth in a wide range of light conditions, while the lack of active plasticity in A. pilosa resulted in a strong dependence of shoot growth on light availability. We propose that high levels of environmental stress in marginal areas of a species' range may lead to a significant reduction in the degree of active plasticity. Our results clearly indicate that discrimination between active and passive plasticity is crucial for reaching valid conclusions about differences in adaptive plasticity between marginal and non

  6. Clonal diversity of Clintonia udensis Trautv.et Mey. populations and its correlation with ecological factors

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The clonal diversity of Clintonia udensis Trautv.et Mey.was detected by ISSR markers among 16 populations,and its correlation with ecological factors was analyzed as well in this work.Results showed that individuals(clonal ramets)per genotype were 1.12 and 1.149 at population and species levels,respectively,and that the 16 populations were all multiclonal.The detected genotypes were localized,without exception,within populations but demonstrated relatively high clonal differentiation among populations.The clonal diversity of the studied populations was high,with the average Simpson’s index of 0.975,while the genets showed a clonal architecture of"guerilla".The population genetic diversities revealed by genet were consistent with those by ramet,further confirming their genetic differentiation among populations.And its genotype diversity within populations probably resulted largely from the frequent seedling regeneration and self-compatibility.In addition,the correlation analysis further revealed that,among the ecological factors,Simpson’s index of C.udensis had a significant positive correlation(P<0.05)with pH values in the soil but not others.

  7. Trait mindfulness as a limiting factor for residual depressive symptoms: an explorative study using quantile regression.

    Directory of Open Access Journals (Sweden)

    Sholto Radford

    Full Text Available Mindfulness has been suggested to be an important protective factor for emotional health. However, this effect might vary with regard to context. This study applied a novel statistical approach, quantile regression, in order to investigate the relation between trait mindfulness and residual depressive symptoms in individuals with a history of recurrent depression, while taking into account symptom severity and number of episodes as contextual factors. Rather than fitting to a single indicator of central tendency, quantile regression allows exploration of relations across the entire range of the response variable. Analysis of self-report data from 274 participants with a history of three or more previous episodes of depression showed that relatively higher levels of mindfulness were associated with relatively lower levels of residual depressive symptoms. This relationship was most pronounced near the upper end of the response distribution and moderated by the number of previous episodes of depression at the higher quantiles. The findings suggest that with lower levels of mindfulness, residual symptoms are less constrained and more likely to be influenced by other factors. Further, the limiting effect of mindfulness on residual symptoms is most salient in those with higher numbers of episodes.

  8. Trait Mindfulness as a Limiting Factor for Residual Depressive Symptoms: An Explorative Study Using Quantile Regression

    Science.gov (United States)

    Radford, Sholto; Eames, Catrin; Brennan, Kate; Lambert, Gwladys; Crane, Catherine; Williams, J. Mark G.; Duggan, Danielle S.; Barnhofer, Thorsten

    2014-01-01

    Mindfulness has been suggested to be an important protective factor for emotional health. However, this effect might vary with regard to context. This study applied a novel statistical approach, quantile regression, in order to investigate the relation between trait mindfulness and residual depressive symptoms in individuals with a history of recurrent depression, while taking into account symptom severity and number of episodes as contextual factors. Rather than fitting to a single indicator of central tendency, quantile regression allows exploration of relations across the entire range of the response variable. Analysis of self-report data from 274 participants with a history of three or more previous episodes of depression showed that relatively higher levels of mindfulness were associated with relatively lower levels of residual depressive symptoms. This relationship was most pronounced near the upper end of the response distribution and moderated by the number of previous episodes of depression at the higher quantiles. The findings suggest that with lower levels of mindfulness, residual symptoms are less constrained and more likely to be influenced by other factors. Further, the limiting effect of mindfulness on residual symptoms is most salient in those with higher numbers of episodes. PMID:24988072

  9. Genetic and environmental factors influencing the Placental Growth Factor (PGF) variation in two populations

    DEFF Research Database (Denmark)

    Sorice, Rossella; Ruggiero, Daniela; Nutile, Teresa

    2012-01-01

    . However, to date, no information is available regarding the genetics of PGF variability. Furthermore, even though the effect of environmental factors (e.g.: cigarette smoking) on angiogenesis has been explored, no data on the influence of these factors on PGF levels have been reported so far. Here we have...... strongly replicated in the Danish sample. These results, for the first time, support the hypothesis of the presence of genetic and environmental factors influencing PGF plasma variability....

  10. Spatiotemporal dataset on Chinese population distribution and its driving factors from 1949 to 2013

    Science.gov (United States)

    Wang, Lizhe; Chen, Lajiao

    2016-07-01

    Spatio-temporal data on human population and its driving factors is critical to understanding and responding to population problems. Unfortunately, such spatio-temporal data on a large scale and over the long term are often difficult to obtain. Here, we present a dataset on Chinese population distribution and its driving factors over a remarkably long period, from 1949 to 2013. Driving factors of population distribution were selected according to the push-pull migration laws, which were summarized into four categories: natural environment, natural resources, economic factors and social factors. Natural environment and natural resources indicators were calculated using Geographic Information System (GIS) and Remote Sensing (RS) techniques, whereas economic and social factors from 1949 to 2013 were collected from the China Statistical Yearbook and China Compendium of Statistics from 1949 to 2008. All of the data were quality controlled and unified into an identical dataset with the same spatial scope and time period. The dataset is expected to be useful for understanding how population responds to and impacts environmental change.

  11. Population-Based Assessment of Hypertension Epidemiology and Risk Factors among HIV-Positive and General Populations in Rural Uganda.

    Directory of Open Access Journals (Sweden)

    Dalsone Kwarisiima

    Full Text Available Antiretroviral therapy scale-up in Sub-Saharan Africa has created a growing, aging HIV-positive population at risk for non-communicable diseases such as hypertension. However, the prevalence and risk factors for hypertension in this population remain incompletely understood.We measured blood pressure and collected demographic data on over 65,000 adults attending multi-disease community health campaigns in 20 rural Ugandan communities (SEARCH Study: NCT01864603. Our objectives were to determine (i whether HIV is an independent risk factor for hypertension, and (ii awareness and control of hypertension in HIV-positive adults and the overall population.Hypertension prevalence was 14% overall, and 11% among HIV-positive individuals. 79% of patients were previously undiagnosed, 85% were not taking medication, and 50% of patients on medication had uncontrolled blood pressure. Multivariate predictors of hypertension included older age, male gender, higher BMI, lack of education, alcohol use, and residence in Eastern Uganda. HIV-negative status was independently associated with higher odds of hypertension (OR 1.2, 95% CI: 1.1-1.4. Viral suppression of HIV did not significantly predict hypertension among HIV-positives.The burden of hypertension is substantial and inadequately controlled, both in HIV-positive persons and overall. Universal HIV screening programs could provide counseling, testing, and treatment for hypertension in Sub-Saharan Africa.

  12. Prevalence and Risk Factors of Gallbladder Polypoid Lesions in a Healthy Population

    OpenAIRE

    Choi, Yoo Shin; Do, Jae Hyuk; Seo, Suk Won; Lee, Seung Eun; Oh, Hyoung-Chul; Min, Yun Joo; Kang, Hyun

    2016-01-01

    Purpose To determine the prevalence of and investigate the risk factors for gallbladder (GB) polypoid lesions in a healthy population. Materials and Methods A total of 23827 subjects who underwent abdominal ultrasonography in conjunction with health screening examinations were retrospectively analyzed. The prevalence of risk factors for GB polypoid lesions were evaluated. In addition, risk factors according to the number of polypoid lesions and the presence of stones with polypoid lesions wer...

  13. Modeling of the ComRS signaling pathway reveals the limiting factors controlling competence in Streptococcus thermophilus

    Directory of Open Access Journals (Sweden)

    Laurie eHaustenne

    2015-12-01

    Full Text Available In streptococci, entry in competence is dictated by ComX abundance. In Streptococcus thermophilus, production of ComX is transient and tightly regulated during growth: it is positively regulated by the cell-cell communication system ComRS during the activation phase and negatively regulated during the shut-off phase by unidentified late competence gene(s. Interestingly, most S. thermophilus strains are not or weakly transformable in permissive growth conditions (i.e. chemically defined medium, CDM, suggesting that some players of the ComRS regulatory pathway are limiting. Here, we combined mathematical modeling and experimental approaches to identify the components of the ComRS system which are critical for both dynamics and amplitude of ComX production in S. thermophilus. We built a deterministic, population-scaled model of the time-course regulation of specific ComX production in CDM growth conditions. Strains LMD-9 and LMG18311 were respectively selected as representative of highly and weakly transformable strains. Results from in silico simulations and in vivo luciferase activities show that ComR concentration is the main limiting factor for the level of comX expression and controls the kinetics of spontaneous competence induction in strain LMD-9. In addition, the model predicts that the poor transformability of strain LMG18311 results from a 10-fold lower comR expression level compared to strain LMD-9. In agreement, comR overexpression in both strains was shown to induce higher competence levels with deregulated kinetics patterns during growth. In conclusion, we propose that the level of ComR production is one important factor that could explain competence heterogeneity among S. thermophilus strains.

  14. Modeling of the ComRS Signaling Pathway Reveals the Limiting Factors Controlling Competence in Streptococcus thermophilus

    Science.gov (United States)

    Haustenne, Laurie; Bastin, Georges; Hols, Pascal; Fontaine, Laetitia

    2015-01-01

    In streptococci, entry in competence is dictated by ComX abundance. In Streptococcus thermophilus, production of ComX is transient and tightly regulated during growth: it is positively regulated by the cell-cell communication system ComRS during the activation phase and negatively regulated during the shut-off phase by unidentified late competence gene(s). Interestingly, most S. thermophilus strains are not or weakly transformable in permissive growth conditions (i.e., chemically defined medium, CDM), suggesting that some players of the ComRS regulatory pathway are limiting. Here, we combined mathematical modeling and experimental approaches to identify the components of the ComRS system which are critical for both dynamics and amplitude of ComX production in S. thermophilus. We built a deterministic, population-scaled model of the time-course regulation of specific ComX production in CDM growth conditions. Strains LMD-9 and LMG18311 were respectively selected as representative of highly and weakly transformable strains. Results from in silico simulations and in vivo luciferase activities show that ComR concentration is the main limiting factor for the level of comX expression and controls the kinetics of spontaneous competence induction in strain LMD-9. In addition, the model predicts that the poor transformability of strain LMG18311 results from a 10-fold lower comR expression level compared to strain LMD-9. In agreement, comR overexpression in both strains was shown to induce higher competence levels with deregulated kinetics patterns during growth. In conclusion, we propose that the level of ComR production is one important factor that could explain competence heterogeneity among S. thermophilus strains. PMID:26733960

  15. Sociological Factors and Structural Limitations on College Students' Participation in Recreational Activities

    Directory of Open Access Journals (Sweden)

    Metin KILIÇ

    2013-12-01

    Full Text Available Socio-cultural factors are said to exist on the basis of the participating in the recreational activities. In today's complex social structure, institutionally, individuals' recreational activities have become a problematic issue. Thus, it is thought to be vital that studies must be done in order to create spaces for recreational activities for the integration of young people with the existing social structure and increase the participation level to these activities. This research was carried out on the students who studied in different faculties of Adiyaman University in 2012-2013. The sample of research was determined according to random sampling technique, compliant with the criteria's of the level of representing the population. The study is a descriptive field research in which 391 questionnaires were conducted. As a result of the research it was determined that the college students' recreation opportunities, which are factors in the process of socializing and effect their personalities, are inadequate. Besides, striking results were gained regarding their expectations from university.

  16. Assessment of iodine status and associated factors in vulnerable populations in Henan Province, China, in 2012.

    Science.gov (United States)

    Yang, Jin; Zheng, Heming; Li, Xiaofeng; Zhu, Lin; Hao, Zongyu; Chen, Gan; Liu, Yang; Wang, Yanli

    2014-01-01

    Iodine content in table salt was adjusted from 30-50 mg/kg to 21-39 mg/kg from March of 2012 in Henan Province, China. The vulnerable population may be at risk of iodine deficiency. To determine whether the iodine intake was sufficient in vulnerable populations and to investigate what factors may be associated with iodine status in these vulnerable populations in Henan Province, China. A cross-sectional survey was conducted in 17 cities in Henan Province, China, from April 2012 to December 2012 to assess the iodine status in vulnerable populations, including women of reproductive-age (n=2648), pregnant women (n=39684), lactating women (n=6859), infants factors were collected from the investigated women to identify factors that were related to iodine intake and iodine status. The median urinary iodine concentrations (mUICs) were 205 μg/L, 198 μg/L, 167 μg/L, 205 μg/L and 200 μg/L, respectively, in reproductiveage, pregnant and lactating women, infants factors for UIC. Iodine status of the vulnerable populations was generally adequate in Henan Province, China, according to WHO criteria. But the mUICs were slightly above the adequate level in reproductive-age women and children aged 8-10 years. It's important to monitor the iodine status in vulnerable populations after the adjustment on iodine content in table salt.

  17. The search for life on Europa: limiting environmental factors, potential habitats, and Earth analogues.

    Science.gov (United States)

    Marion, Giles M; Fritsen, Christian H; Eicken, Hajo; Payne, Meredith C

    2003-01-01

    The putative ocean of Europa has focused considerable attention on the potential habitats for life on Europa. By generally clement Earth standards, these Europan habitats are likely to be extreme environments. The objectives of this paper were to examine: (1) the limits for biological activity on Earth with respect to temperature, salinity, acidity, desiccation, radiation, pressure, and time; (2) potential habitats for life on Europa; and (3) Earth analogues and their limitations for Europa. Based on empirical evidence, the limits for biological activity on Earth are: (1) the temperature range is from 253 to 394 K; (2) the salinity range is a(H2O) = 0.6-1.0; (3) the desiccation range is from 60% to 100% relative humidity; (4) the acidity range is from pH 0 to 13; (5) microbes such as Deinococcus are roughly 4,000 times more resistant to ionizing radiation than humans; (6) the range for hydrostatic pressure is from 0 to 1,100 bars; and (7) the maximum time for organisms to survive in the dormant state may be as long as 250 million years. The potential habitats for life on Europa are the ice layer, the brine ocean, and the seafloor environment. The dual stresses of lethal radiation and low temperatures on or near the icy surface of Europa preclude the possibility of biological activity anywhere near the surface. Only at the base of the ice layer could one expect to find the suitable temperatures and liquid water that are necessary for life. An ice layer turnover time of 10 million years is probably rapid enough for preserving in the surface ice layers dormant life forms originating from the ocean. Model simulations demonstrate that hypothetical oceans could exist on Europa that are too cold for biological activity (T salinities are high, which would restrict life to extreme halophiles. An acidic ocean (if present) could also potentially limit life. Pressure, per se, is unlikely to directly limit life on Europa. But indirectly, pressure plays an important role in

  18. The cytokines interleukin 27 and interferon-γ promote distinct Treg cell populations required to limit infection-induced pathology.

    Science.gov (United States)

    Hall, Aisling O'Hara; Beiting, Daniel P; Tato, Cristina; John, Beena; Oldenhove, Guillaume; Lombana, Claudia Gonzalez; Pritchard, Gretchen Harms; Silver, Jonathan S; Bouladoux, Nicolas; Stumhofer, Jason S; Harris, Tajie H; Grainger, John; Wojno, Elia D Tait; Wagage, Sagie; Roos, David S; Scott, Philip; Turka, Laurence A; Cherry, Sara; Reiner, Steven L; Cua, Daniel; Belkaid, Yasmine; Elloso, M Merle; Hunter, Christopher A

    2012-09-21

    Interferon-γ (IFN-γ) promotes a population of T-bet(+) CXCR3(+) regulatory T (Treg) cells that limit T helper 1 (Th1) cell-mediated pathology. Our studies demonstrate that interleukin-27 (IL-27) also promoted expression of T-bet and CXCR3 in Treg cells. During infection with Toxoplasma gondii, a similar population emerged that limited T cell responses and was dependent on IFN-γ in the periphery but on IL-27 at mucosal sites. Transfer of Treg cells ameliorated the infection-induced pathology observed in Il27(-/-) mice, and this was dependent on their ability to produce IL-10. Microarray analysis revealed that Treg cells exposed to either IFN-γ or IL-27 have distinct transcriptional profiles. Thus, IFN-γ and IL-27 have different roles in Treg cell biology and IL-27 is a key cytokine that promotes the development of Treg cells specialized to control Th1 cell-mediated immunity at local sites of inflammation.

  19. Clustering of metabolic syndrome factors in Malaysian population: Asian Criteria revisited

    Directory of Open Access Journals (Sweden)

    YN Azwany

    2011-08-01

    Full Text Available Introduction: Metabolic syndrome (MetS had been known as clustering of risk factors for cardiovascular disease and diabetes. Over the years, clinical criteria had been revised to highlight importance of various risk factors in defining MetS. Studies had reported different clustering of factors based on different population characteristics.Objective: Our study aimed to identify the clustering factors among our Malaysian population based on sexes and 4 major ethnic groups namely Malay, Chinese, Indian and other minor ethnicMethods: A national cross sectional study was done covering both Peninsular and East Malaysia. Subjects’ sociodemographic, body mass index (BMI, waist, hip and neck circumference, blood pressure, fasting triglycerides (TG and HDL-cholesterol and glucose, urine microalbumin and serum insulin were taken. Principal component factor analysis with Varimax rotation was done to identify the clustering based on sex and ethnic groups.Results: One thousand two hundred and sixty eight male and 2355 female subjects were recruited. Majority of subjects were Malays (63.0% followed by Chinese (13.3%, Indian (7.4% and other ethnic groups (13.8% which followed the population composition in Malaysia. Four factors were identified for both men and women. The factors were anthropometry, glycemia, blood pressure and dyslipidemia given the cumulative percent of variance of 69.4 and 65.9 respectively. There are 4 factors identified for Malay, Chinese and Aborigines but 5 factors for Indian ethnic groups given cumulative percent of variance explained ranged from 65.1 to 77.7.Discussion and Conclusion: BMI, neck circumference, blood pressure, Fasting TG and HDL had a high factor loading in both sexes suggesting that for field screening, diagnostic criteria would be adequate criteria. These factors also showed a similar pattern of loading by different ethnic groups. In conclusion, in Malaysian population, at least one measurement from each components

  20. Systematic Review of Factors Influencing Farmers' Market Use Overall and among Low-Income Populations.

    Science.gov (United States)

    Freedman, Darcy A; Vaudrin, Nicole; Schneider, Christine; Trapl, Erika; Ohri-Vachaspati, Punam; Taggart, Morgan; Ariel Cascio, M; Walsh, Colleen; Flocke, Susan

    2016-07-01

    Recent evidence indicates a widening gap in fruit and vegetable (F/V) consumption between high- and low-income Americans. This gap is related, in part, to decreased access to food retailers that sell fresh F/V in low-income communities. Farmers' markets are identified as a strategy for improving F/V consumption by increasing access to these foods. The aim of this systematic review was to examine literature published from 1994 to 2014 to identify facilitators and barriers of farmers' markets use, particularly among low-income consumers. Peer-reviewed literature was identified in Ebsco Host (Academic Search Complete). Inclusion criteria for abstract review was primary research focused on farmers' market use identifying 87 studies for full-text review. Full-text review identified articles focused on facilitators and/or barriers of farmers' market use resulting in 49 articles. At least two reviewers completed review of all articles. Of the 49 articles, 39% specified inclusion of low-income consumers and fewer than 15% focused on racial and ethnic minorities. Few studies were guided by theory and/or used standardized metrics. Results indicate farmers' market use is influenced by multiple economic, service delivery, spatial-temporal, social, and personal factors. Among studies that included low-income populations (n=19), key barriers to farmers' market use were perceptions that food assistance benefits were not accepted, belief that food variety at farmers' markets was limited, lack of access to transportation, lack of racial/ethnic diversity in the market space, and mismatch between markets and personal lifestyles. There is wide variation in study design and reporting standards and infrequent use of standardized measures limiting comparisons across studies. There is a need to establish valid and reliable metrics and reporting standards for evaluating farmers' markets. Findings may inform interventions, programs, and policies to promote farmers' market use. Copyright

  1. Factors Limiting Formation of Community Forestry Enterprises in the Southern Mixteca Region of Oaxaca, Mexico

    Science.gov (United States)

    Hernández-Aguilar, José Antonio; Cortina-Villar, Héctor Sergio; García-Barrios, Luis Enrique; Castillo-Santiago, Miguel Ángel

    2017-03-01

    Many studies have considered community-based forestry enterprises to be the best option for development of rural Mexican communities with forests. While some of Mexico's rural communities with forests receive significant economic and social benefits from having a community forestry enterprise, the majority have not formed such enterprises. The purpose of this article is to identify and describe factors limiting the formation of community forestry enterprise in rural communities with temperate forests in the Southern Mixteca region of Oaxaca, Mexico. The study involved fieldwork, surveys applied to Community Board members, and maps developed from satellite images in order to calculate the forested surface area. It was found that the majority of Southern Mixteca communities lack the natural and social conditions necessary for developing community forestry enterprise; in this region, commercial forestry is limited due to insufficient precipitation, scarcity of land or timber species, community members' wariness of commercial timber extraction projects, ineffective local governance, lack of capital, and certain cultural beliefs. Only three of the 25 communities surveyed have a community forestry enterprise; however, several communities have developed other ways of profiting from their forests, including pine resin extraction, payment for environmental services (PES), sale of spring water, and ecotourism. We conclude that community forestry enterprise are not the only option for rural communities to generate income from their forests; in recent years a variety of forest-related economic opportunities have arisen which are less demanding of communities' physical and social resources.

  2. Searching out the hydrogen absorption/desorption limiting reaction factors: Strategies allowing to increase kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Zeaiter, Ali, E-mail: ali.zeaiter@femto-st.fr; Chapelle, David; Nardin, Philippe

    2015-10-05

    Highlights: • A macro scale thermodynamic model that simulates the response of a FeTi-X hydride tank is performed, and validated experimentally. • A sensibility study to identify the most influent input variables that can changes very largely the reaction rate. - Abstract: Hydrogen gas has become one of the most promising energy carriers. Main breakthrough concerns hydrogen solid storage, specially based on intermetallic material use. Regarding the raw material abundance and cost, the AB type alloy FeTi is an auspicious candidate to store hydrogen. Its absorption/desorption kinetics is a basic hindrance to common use, compared with more usual hydrides. First, discussions based on literature help us identifying the successive steps leading to metal hydriding, and allow to introduce the physical parameters which drive or limit the reaction. This analysis leads us to suggest strategies in order to increase absorption/desorption kinetics. Attention is then paid to a thermofluidodynamic model, allowing to describe a macroscopic solid storage reactor. Thus, we can achieve a simulation which describes the overall reaction inside the hydrogen reactor and, by varying the sub-mentioned parameters (thermal conductivity, the powder granularity, environment heat exchange…), we attempt to hierarchy the reaction limiting factors. These simulations are correlated to absorption/desorption experiments for which pressure, temperature and hydrogen flow are recorded.

  3. Biotic and abiotic factors predicting the global distribution and population density of an invasive large mammal

    Science.gov (United States)

    Lewis, Jesse S.; Farnsworth, Matthew L.; Burdett, Chris L.; Theobald, David M.; Gray, Miranda; Miller, Ryan S.

    2017-01-01

    Biotic and abiotic factors are increasingly acknowledged to synergistically shape broad-scale species distributions. However, the relative importance of biotic and abiotic factors in predicting species distributions is unclear. In particular, biotic factors, such as predation and vegetation, including those resulting from anthropogenic land-use change, are underrepresented in species distribution modeling, but could improve model predictions. Using generalized linear models and model selection techniques, we used 129 estimates of population density of wild pigs (Sus scrofa) from 5 continents to evaluate the relative importance, magnitude, and direction of biotic and abiotic factors in predicting population density of an invasive large mammal with a global distribution. Incorporating diverse biotic factors, including agriculture, vegetation cover, and large carnivore richness, into species distribution modeling substantially improved model fit and predictions. Abiotic factors, including precipitation and potential evapotranspiration, were also important predictors. The predictive map of population density revealed wide-ranging potential for an invasive large mammal to expand its distribution globally. This information can be used to proactively create conservation/management plans to control future invasions. Our study demonstrates that the ongoing paradigm shift, which recognizes that both biotic and abiotic factors shape species distributions across broad scales, can be advanced by incorporating diverse biotic factors. PMID:28276519

  4. Difficult laryngoscopy and intubation in the Indian population: An assessment of anatomical and clinical risk factors

    Directory of Open Access Journals (Sweden)

    Smita Prakash

    2013-01-01

    Full Text Available Background and Aim: Differences in patient characteristics due to race or ethnicity may influence the incidence of difficult airway. Our purpose was to determine the incidence of difficult laryngoscopy and intubation, as well as the anatomical features and clinical risk factors that influence them, in the Indian population. Methods: In 330 adult patients receiving general anaesthesia with tracheal intubation, airway characteristics and clinical factors were determined and their association with difficult laryngoscopy (Cormack and Lehane grade 3 and 4 was analysed. Intubation Difficulty Scale score was used to identify degree of difficult laryngoscopy. Results: The incidence of difficult laryngoscopy and intubation was 9.7% and 4.5%, respectively. Univariate analysis showed that increasing age and weight, male gender, modified Mallampati class (MMC 3 and 4 in sitting and supine positions, inter-incisor distance (IID ≤3.5 cm, thyromental (TMD and sternomental distance, ratio of height and TMD, short neck, limited mandibular protrusion, decreased range of neck movement, history of snoring, receding mandible and cervical spondylosis were associated with difficult laryngoscopy. Multivariate analysis identified four variables that were independently associated with difficult laryngoscopy: MMC class 3 and 4, range of neck movement <80°, IID ≤ 3.5 cm and snoring. Conclusions: We found an incidence of 9.7% and 4.5% for difficult laryngoscopy and difficult intubation, respectively, in Indian patients with apparently normal airways. MMC class 3 and 4, range of neck movement <80°, IID ≤ 3.5 cm and snoring were independently related to difficult laryngoscopy. There was a high incidence (48.5% of minor difficulty in intubation.

  5. Difficult laryngoscopy and intubation in the Indian population: An assessment of anatomical and clinical risk factors.

    Science.gov (United States)

    Prakash, Smita; Kumar, Amitabh; Bhandari, Shyam; Mullick, Parul; Singh, Rajvir; Gogia, Anoop Raj

    2013-11-01

    Differences in patient characteristics due to race or ethnicity may influence the incidence of difficult airway. Our purpose was to determine the incidence of difficult laryngoscopy and intubation, as well as the anatomical features and clinical risk factors that influence them, in the Indian population. In 330 adult patients receiving general anaesthesia with tracheal intubation, airway characteristics and clinical factors were determined and their association with difficult laryngoscopy (Cormack and Lehane grade 3 and 4) was analysed. Intubation Difficulty Scale score was used to identify degree of difficult laryngoscopy. The incidence of difficult laryngoscopy and intubation was 9.7% and 4.5%, respectively. Univariate analysis showed that increasing age and weight, male gender, modified Mallampati class (MMC) 3 and 4 in sitting and supine positions, inter-incisor distance (IID) ≤3.5 cm, thyromental (TMD) and sternomental distance, ratio of height and TMD, short neck, limited mandibular protrusion, decreased range of neck movement, history of snoring, receding mandible and cervical spondylosis were associated with difficult laryngoscopy. Multivariate analysis identified four variables that were independently associated with difficult laryngoscopy: MMC class 3 and 4, range of neck movement <80°, IID ≤ 3.5 cm and snoring. We found an incidence of 9.7% and 4.5% for difficult laryngoscopy and difficult intubation, respectively, in Indian patients with apparently normal airways. MMC class 3 and 4, range of neck movement <80°, IID ≤ 3.5 cm and snoring were independently related to difficult laryngoscopy. There was a high incidence (48.5%) of minor difficulty in intubation.

  6. Understanding Early Contextual and Parental Risk Factors for the Development of Limited Prosocial Emotions.

    Science.gov (United States)

    Waller, Rebecca; Shaw, Daniel S; Forbes, Erika E; Hyde, Luke W

    2015-08-01

    A growing body of evidence suggests that parenting influences the development of youth callous unemotional (CU) behavior. However, less is known about the effects of parenting or contextual risk factors on 'limited prosocial emotions' (LPE), a recent conceptualization of CU behavior added to the DSM-5. We focused on LPE at ages 10-12 and age 20 among low income, urban males (N = 310), and examined potential developmental precursors, including contextual risk factors assessed during infancy and observed maternal warmth during the toddler period. We found unique direct associations between maternal warmth, maternal aggression, and low empathetic awareness on LPE at ages 10-12, controlling for concurrent self-reported antisocial behavior. Further, there were indirect effects of maternal aggression, low empathetic awareness, and difficult infant temperament assessed in infancy on LPE at ages 10-12 via their influence on maternal warmth at age 2. Finally, there were lasting indirect effects of parental warmth on LPE at age 20, via LPE at ages 10-12. We discuss the implications of these findings for ecological models of antisocial behavior and LPE development, and preventative interventions that target the broader early parenting environment.

  7. Understanding early contextual and parental risk factors for the development of limited prosocial emotions

    Science.gov (United States)

    Waller, Rebecca; Shaw, Daniel S.; Forbes, Erika E.; Hyde, Luke W.

    2014-01-01

    A growing body of evidence suggests that parenting influences the development of youth callous unemotional (CU) behavior. However, less is known about the effects of parenting or contextual risk factors on ‘limited prosocial emotions’ (LPE), a recent conceptualization of CU behavior added to the DSM-5. We focused on LPE at ages 10–12 and age 20 among low income, urban males (N = 310), and examined potential developmental precursors, including contextual risk factors assessed during infancy and observed maternal warmth during the toddler period. We found unique direct associations between maternal warmth, maternal aggression, and low empathetic awareness on LPE at ages 10–12, controlling for concurrent self-reported antisocial behavior. Further, there were indirect effects of maternal aggression, low empathetic awareness, and difficult infant temperament assessed in infancy on LPE at ages 10–12 via their influence on maternal warmth at age 2. Finally, there were lasting indirect effects of parental warmth on LPE at age 20, via LPE at ages 10–12. We discuss the implications of these findings for ecological models of antisocial behavior and LPE development, and preventative interventions that target the broader early parenting environment. PMID:25510355

  8. Soil development as limiting factor for shrub expansion in southwestern Greenland

    Science.gov (United States)

    Caviezel, Chatrina; Hunziker, Matthias; Zoller, Oliver; Wüthrich, Christoph; Kuhn, Nikolaus J.

    2014-05-01

    Southern Greenland currently experiences an increase in summer temperatures and a prolonged growing season (Masson-Delmotte et al. 2012), resulting in an increased shrub cover at the boreal - tundra border ecotone (Normand et al. 2013). These findings suggest the beginning of a greener Greenland in which tundra vegetation is transformed to a boreal woody flora. However, vegetation at borderline ecotones is influenced by further ecologic factors than just temperature. In this study, the ecologic conditions at a selection of sites along an elevation gradient near Igaliku in southern Greenland were examined to identify potential factors limiting the expansion of woody vegetation apart from temperature. The sites differ in elevation, topography, shrub density and soil parent material. The three study sites comprise i) well established birch shrubs growing between 50 and 180 m a.s.l., where the parent material origins from the Julianehab granite (Brooks 2012); ii) extended shrub patches at about 250 m a.s.l., where the parent material consists of Gardar Sandstones and Lavas (Brooks 2012) and iii) restricted shrub patches at an elevation of 250 m a.s.l., where the soil parent material originates from the Gardar intrusions (Brooks 2012). The extent of the shrub areas, topography and soil moisture were mapped, additionally soil samples were analyzed for C-and N-content, texture including coarse fraction and pH and used as soil development indicators. Our results show that the topographic setting regulates the existence or absence of soil while the soil parent material is an important limiting factor for soil moisture. According to these findings, we suggest that a high proportion of areas where temperature increase would allow the increase of shrub cover is not suitable for a woody flora. Brooks, Kent. 2012. "A Tale of Two Intrusions—where Familiar Rock Names No Longer Suffice." Geology Today 28 (1): 13-19. doi:10.1111/j.1365-2451.2012.00815.x. Masson-Delmotte, V., D

  9. Limitations in Activities of Daily Living in Community-Dwelling People Aged 75 and Over: A Systematic Literature Review of Risk and Protective Factors

    Science.gov (United States)

    Zijlstra, G. A. Rixt; Witte, Nico De; Duppen, Daan; Stuck, Andreas E.; Kempen, Gertrudis I. J. M.; Schols, Jos M. G. A.

    2016-01-01

    Background Most older people wish to age in place, for which functional status or being able to perform activities of daily living (ADLs) is an important precondition. However, along with the substantial growth of the (oldest) old, the number of people who develop limitations in ADLs or have functional decline dramatically increases in this part of the population. Therefore, it is important to gain insight into factors that can contribute to developing intervention strategies at older ages. As a first step, this systematic review was conducted to identify risk and protective factors as predictors for developing limitations in ADLs in community-dwelling people aged 75 and over. Methods Four electronic databases (CINAHL (EBSCO), EMBASE, PsycINFO and PubMed) were searched systematically for potentially relevant studies published between January 1998 and March 2016. Results After a careful selection process, 6,910 studies were identified and 25 were included. By far most factors were examined in one study only, and most were considered risk factors. Several factors do not seem to be able to predict the development of limitations in ADLs in people aged 75 years and over, and for some factors ambiguous associations were found. The following risk factors were found in at least two studies: higher age, female gender, diabetes, hypertension, and stroke. A high level of physical activity and being married were protective in multiple studies. Notwithstanding the fact that research in people aged 65 years and over is more extensive, risk and protective factors seem to differ between the ‘younger’ and ‘older’ olds. Conclusion Only a few risk and protective factors in community-dwelling people aged 75 years and over have been analysed in multiple studies. However, the identified factors could serve both detection and prevention purposes, and implications for future research are given as well. PMID:27760234

  10. Age trends in prevalence of cardiovascular risk factors in Roma minority population of Croatia.

    Science.gov (United States)

    Zeljko, Hrvojka Marija; Skarić-Jurić, Tatjana; Narančić, Nina Smolej; Barešić, Ana; Tomas, Zeljka; Petranović, Matea Zajc; Miličić, Jasna; Salihović, Marijana Peričić; Janićijević, Branka

    2013-07-01

    The Roma (Gypsy) are the largest European minority population characterized by poverty, social exclusion as well as by numerous life-style and cultural specificities, which all could have an adverse impact on their cardiovascular health. This study assesses the prevalence of cardiovascular diseases (CVD) risk factors in community-based sample of 430 adult Roma, living in rural area of Croatia, by providing the actual and age-adjusted estimates using the European standard population. The most prominent classical CVD risk phenotypes (blood pressure, obesity, smoking, glucose and lipid profile) were selected, and the standard risk cut-offs were applied. The study has shown that compared to general population of Croatia, the Roma population bears a high CVD risk factors load related to smoking and high glucose level. The CVD risk factors prevalence in Roma also showed important sex and age patterns, the most imposing of which are the findings of higher prevalence of CVD risks in women (especially obesity and triglyceride levels) and the trend of higher body mass index (BMI) level in younger age group (18-34 years) which both stand in contrast to the trends characterizing the general population of Croatia. These findings are complemented by the trend of decreased risk in the oldest age group (65+ years) for all investigated CVD risk factors (with exception of triglycerides level) compared to the 50-64 age group. We conclude that the age and sex CVD risks pattern point to the health transition of this rural Roma population. As we expect the proportion of CVD in the Roma minority of Croatia to increase in the future along with further modernization of their lifestyle, the CVD prevention measures in this population are urgent and should be primarily targeted at women and at the younger segment of this population.

  11. Limiting Factors for Agricultural Production and Differentiation of Soil Management in Romania

    Science.gov (United States)

    Ioana Moraru, Paula; Rusu, Teodor; Bogdan, Ileana; Ioan Pop, Adrian; Pop, Horia

    2017-04-01

    Romania's land area is 23,839,100 ha; 0.16% of the world's surface. Worldwide, Romania is ranked #83 for areal extent, and it consitutes 4.81% of the Europe's surface (ranked #12). Romania has 14,856,800 ha of agricultural land which represents 62.3% of the total surface; 0.65 ha per capita. At the national level, 72.5% and 27.5% of soils in Romania can be broadly classed as very poor and good/very good, respectively, based on intrinsic soil characteristics, climate, topography, and ground water. Romania has a specific geographical situation, namely: i) Romanian territory is located in the southeast portion of Central Europe at the cross roads of several high and low pressure centers that form regularly at the borders. The influence of these air masses is altered by the presence in the central regions of the Carpathian mountain chain resulting in a diverse climate with average annual rain fall amounts between 350 to 1,400 mm and average annual temperatures between 2 and 11.5°C. ii) At the national level, almost all soils in the international classification system are present in Romania; each soil type having specific properties and characteristics. iii) On approximately 12.5 million ha (7.5 million ha arable), soil fertility is adversely affected by erosion, acidity, low humus content, extreme texture (clay, sand), excessive moisture, chemical pollution etc. These natural and anthropogenic factors dramatically influence agricultural production. Furthermore, soil, climate, topography, etc. vary widely not only across the country, but also on smaller scales, even across fields within the same farm. In Steppe zone limitative climatic factors, which require differentiation towards soil management use, include: long periods of drought, high temperatures, high frequency winds (wind erosion in area of sands), low relative air humidity, and harsh frosts during winter. Negative phenomena most commonly encountered in this area are salinization, excess water, temporary

  12. Factors associated with maternal mortality in rural Guinea-Bissau. A longitudinal population-based study.

    Science.gov (United States)

    Høj, L; da Silva, D; Hedegaard, K; Sandström, A; Aaby, P

    2002-07-01

    To assess demographic and obstetric risk factors for pregnancy-related death in a multiethnic rural population in a developing country. A prospective survey of women in the fertile age-range. Rural Guinea-Bissau. More than 15,000 women living in 100 clusters were visited at six-monthly intervals over a period of more than six years. A total of 10,931 pregnancies were registered prospectively; 85 of these pregnancies resulted in maternal or late maternal death. Maternal mortality ratio. In the rural areas of Guinea-Bissau, we conducted a prospective survey of women in the fertile age range. More than 15,000 women living in 100 clusters were visited at 6-monthly intervals over a period of more than six years. An analysis of demographic, environmental and obstetric risk factors for maternal death was performed based on 10,931 prospectively registered pregnancies; 85 of these pregnancies resulted in maternal or late maternal death. In the adjusted model maternal mortality ratio increased with increasing distance from the regional hospital (OR>25 km = 7.4 [95% CI: 1.6-132]). Multiple pregnancy was found to increase the risk of maternal death (OR = 3.4 [95% CI: 1.3-7.5]). The risk of subsequent maternal death was increased if the fetus was stillborn (OR = 5.3 [95% CI: 2.8-9.4]). Women living in the region of Gabu had higher mortality than those living in Biombo (OR = 2.5 [95% CI: 1.3-5.1]). No category of age or parity were associated with an increased risk of maternal mortality. Predictive values did not exceed 3% for any of the significant risk factors. For the purpose of reducing maternal mortality, the screening approach of antenatal care is of limited value. Age and parity should not be used routinely as selection criteria for transfer of otherwise healthy pregnant women to higher-level health institutions. Twin pregnancy seems to be the only operational risk factor identified in this study. Stillbirth is associated with an increased risk of maternal death. Regional

  13. Pollen limitation and Allee effect related to population size and sex ratio in the endangered Ottelia acuminata (Hydrocharitaceae): implications for conservation and reintroduction.

    Science.gov (United States)

    Xia, J; Lu, J; Wang, Z X; Hao, B B; Wang, H B; Liu, G H

    2013-03-01

    Small populations may suffer more severe pollen limitation and result in Allee effects. Sex ratio may also affect pollination and reproduction success in dioecious species, which is always overlooked when performing conservation and reintroduction tasks. In this study, we investigated whether and how population size and sex ratio affected pollen limitation and reproduction in the endangered Ottelia acuminata, a dioecious submerged species. We established experimental plots with increasing population size and male sex ratio. We observed insect visitation, estimated pollen limitation by hand-pollinations and counted fruit set and seed production per fruit. Fruit set and seed production decreased significantly in small populations due to pollinator scarcity and thus suffered more severe pollen limitation. Although frequently visited, female-biased larger populations also suffered severe pollen limitation due to few effective visits and insufficient pollen availability. Rising male ratio enhanced pollination service and hence reproduction. Unexpectedly, pollinator preferences did not cause reduced reproduction in male-biased populations because of high pollen availability. However, reproductive outputs showed more variability in severe male-biased populations. Our results revealed two component Allee effects in fruit set and seed production, mediated by pollen limitation in O. acuminata. Moreover, reproduction decreased significantly in larger female-biased populations, increasing the risk of an Allee effect.

  14. Rain, Sun, Soil, and Sweat: A Consideration of Population Limits on Rapa Nui (Easter Island before European Contact

    Directory of Open Access Journals (Sweden)

    Cedric O. Puleston

    2017-07-01

    Full Text Available The incongruity between the small and apparently impoverished Rapa Nui population that early European travelers encountered and the magnificence of its numerous and massive stone statues has fed a deep fascination with the island. Ethnographic and archaeological evidence suggest that the indigenous population was previously greater than the estimated 1,500–3,000 individuals observed by visitors in the eighteenth century. Our goal was to determine the maximum population that might have lived on the island by estimating its agricultural productivity in the time before European contact. To determine the agricultural potential of the island we sampled soils and established six weather stations in diverse contexts and recorded data over a 2-year period. We find that the island is wetter on average than previously believed. We also find that rainfall and temperature respond linearly to elevation, but a spatial model of precipitation requires correction for a rain shadow effect. We adapted to Rapa Nui an island-wide spatial model designed to identify agriculturally viable zones elsewhere in Polynesia. Based on functions relating climate and substrate age to measurements of soil base saturation, we identified 3,134 ha that were suitable for traditional dryland sweet potato cultivation, or about 19% of the 164 km2 island. We used a nutrient-cycling model to estimate yields. Modeled yields are highly sensitive to nitrogen (N inputs and reliable estimates of these rates are unavailable, requiring us to bracket the rate of N inputs. In the case of low N availability, yields under continuous cultivation were very small, averaging 1.5 t/ha of wet sweet potato tuber. When the N fixation rate was quadrupled sustainable yields increased to 5.1 t/ha. In each N scenario we used a model of food-limited demography to examine the consequences of altering agricultural practices, the labor supply, the ability of the population to control its fertility, and the

  15. Factor analysis of the Hospital Anxiety and Depression Scale from a large cancer population.

    Science.gov (United States)

    Smith, Adam B; Selby, Peter J; Velikova, Galina; Stark, Dan; Wright, E Penny; Gould, Ann; Cull, Ann

    2002-06-01

    The Hospital Anxiety and Depression Scale (HADS) is widely used as a tool for assessing psychological distress in patients and non-clinical groups. Previous studies have demonstrated conflicting results regarding the factor structure of the questionnaire for different groups of patients, and the general population. This study investigated the factor structure of the HADS in a large heterogeneous cancer population of 1474 patients. It also sought to investigate emerging evidence that the HADS conforms to the tripartite model of anxiety and depression (Clark & Watson, 1993), and to test the proposal that detection rates for clinical cases of anxiety and depression could be enhanced by partialling out the effects of higher order factors from the HADS (Dunbar et al., 2000). The results demonstrated a two-factor structure corresponding to the Anxiety and Depression subscales of the questionnaire. The factor structure remained stable for different subgroups of the sample, for males and females, as well as for different age groups, and a subgroup of metastatic cancer patients. The two factors were highly correlated (r =.52) and subsequent secondary factor analyses demonstrated a single higher order factor corresponding to psychological distress or negative affectivity. We concluded that the HADS comprises two factors corresponding to anhedonia and autonomic anxiety, which share a common variance with a primary factor namely psychological distress, and that the subscales of the HADS, rather than the residual scores (e.g. Dunbar et al., 2000) were more effective at detecting clinical cases of anxiety and depression.

  16. The limits of populism

    DEFF Research Database (Denmark)

    Hadj-Abdou, Leila; Saharso, Sawitri; Siim, Birte

    2012-01-01

    The presence of Islam and Muslim practices are a matter of fierce contestation in many immigration receiving states in Western Europe. As a consequence of this politicization many European policy makers have decided to restrict the wearing of the female Muslim headscarf. Austria, Denmark and the ...

  17. The limits of populism

    DEFF Research Database (Denmark)

    Hadj-Abdou, Leila; Saharso, Sawitri; Siim, Birte

    2012-01-01

    The presence of Islam and Muslim practices are a matter of fierce contestation in many immigration receiving states in Western Europe. As a consequence of this politicization many European policy makers have decided to restrict the wearing of the female Muslim headscarf. Austria, Denmark and the ......The presence of Islam and Muslim practices are a matter of fierce contestation in many immigration receiving states in Western Europe. As a consequence of this politicization many European policy makers have decided to restrict the wearing of the female Muslim headscarf. Austria, Denmark...

  18. LAND PROPERTY STRUCTURE - A LIMITING FACTOR IN STRENGTHENING THE AGRICULTURAL HOLDINGS

    Directory of Open Access Journals (Sweden)

    Ramona DOBRE

    2013-01-01

    Full Text Available Romania has the largest number of EU holdings. For this purpose, this paper analyses the effect of the excessive agricultural land fragmentation caused by the laws and measures adopted in the previous period. The existence of small holdings is influenced by the land property structures and at the same time, by the training and experience level of holders (heads of holdings. For writing this paper, analyse of statistical data was used in terms of identifying the impact factors which leaded to this holdings situation and, specially, to the fragmentation phenomena, obviously in the agricultural economy. Are highlighted, in order to study the impact, the historical evolution of the Romanian village, the Romanian peasant psychology on property, ownership thirst, desire to have land that would be just his and the need of being the only one who operates it and has benefits of its exploitation. This conception, however, tends to obsession and is generated by a system that has takenthe land from the peasant, leaving him without the essential object of his work. There still exists the fear of no longer having the land, impregnated a lot in their thinking; these resulted in a blockage concerning association, cooperation, lease or any form that could increase the agricultural holdings dimensions. This thinking is manifested in aged population, which is still one of the main problems of the Romanian rural. The effect of these factors, but also of others who will be found in the work act in a negative manner on the formation of a competitive agriculture with an European management orientation. That is why studying them may lead to solutions for the reduction of their influence, the formation of viable social structures and economically valuable.

  19. Colon cancer controls versus population controls in case-control studies of occupational risk factors

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    Sabroe Svend

    2004-04-01

    Full Text Available Abstract Background Since updated population registers do not exist in many countries it is often difficult to sample valid population controls from the study base to a case-control study. Use of patient controls is an alternative option if the exposure experience under study for these patients are interchangeable with the experience for population controls. Patient controls may even be preferable from population controls under certain conditions. In this study we examine if colon cancer patients can serve as surrogates for proper population controls in case-control studies of occupational risk factors. Methods The study was conducted from 1995 to 1997. Incident colon cancer controls (N = 428 aged 35–69 years with a histological verified diagnosis and population controls (N = 583 were selected. Altogether 254 (59% of the colon cancer controls and 320 (55% of the population controls were interviewed about occupational, medical and life style conditions. Results No statistical significant difference for educational level, medical history or smoking status was seen between the two control groups. There was evidence of a higher alcohol intake, less frequent work as a farmer and less exposure to pesticides among colon cancer controls. Conclusions Use of colon cancer controls may provide valid exposure estimates in studies of many occupational risk factors for cancer, but not for studies on exposure related to farming.

  20. Mortality risk factors show similar trends in modern and historic populations exposed to plague.

    Science.gov (United States)

    Rubini, Mauro; Gualdi-Russo, Emanuela; Manzon, Vanessa S; Rinaldo, Natascia; Bianucci, Raffaella

    2016-05-31

    Plague has been responsible for two major historic pandemics (6th-8th century CE; 14th-19th century CE) and a modern one. The recent Malagasy plague outbreaks raised new concerns on the deadly potential of the plague-causing bacteria Yersinia pestis. Between September 2014 and April 2015, outbreaks of bubonic and pneumonic plague hit the Malagasy population. Two hundred and sixty-three cases, including 71 deaths, have been reported in 16 different districts with a case fatality rate of 27%. The scope of our study was to ascertain whether the risk factors for health in modern-day populations exposed to plague and in ancient populations that faced the two historic pandemics varied or remained substantially unaltered. The risk of mortality of the Malagasy population with those obtained from the reconstruction of three samples of European populations exposed to the historic pandemics was contrasted. The evidence shows that the risks of death are not uniform across age neither in modern nor in historic populations exposed to plague and shows precise concentrations in specific age groups (children between five and nine years of age and young adults). Although in the post-antibiotic era, the fatality rates have drastically reduced, both modern and historic populations were exposed to the same risk factors that are essentially represented by a low standard of environmental hygiene, poor nutrition, and weak health systems.

  1. Mycoplasma genitalium: prevalence and behavioural risk factors in the general population

    DEFF Research Database (Denmark)

    Andersen, Berit; Sokolowski, Ineta; Østergaard, Lars;

    2007-01-01

    BACKGROUND: Mycoplasma genitalium has been shown to cause urethritis in men and cervicitis in women and may also be a causative agent in female infertility. OBJECTIVE: To estimate the prevalence of urogenital M genitalium infection and identify sexual behavioural risk factors in the general......, and for men younger age at first intercourse was associated with M genitalium infection. CONCLUSIONS: We conclude that the prevalence of infection in the general population is too low for population-based screening. However, the development of test algorithms based on behavioural risk factors is a promising...

  2. Vascular Endothelial Growth Factor-A Is Associated with Chronic Mountain Sickness in the Andean Population

    OpenAIRE

    Espinoza, Jose R.; Alvarez, Giancarlo; León-Velarde, Fabiola; Ju Preciado, Hugo F.; Macarlupu, Jose-Luis; Rivera-Ch, Maria; Rodriguez, Jorge; Favier, Judith; Gimenez-Roqueplo, Anne-Paule; Richalet, Jean-Paul

    2014-01-01

    Espinoza, Jose R., Giancarlo Alvarez, Fabiola León-Velarde, Hugo F. Ju Preciado, Jose-Luis Macarlupu, Maria Rivera-Ch, Jorge Rodriguez, Judith Favier, Anne-Paule Gimenez-Roqueplo, and Jean-Paul Richalet. Vascular endothelial growth factor-A is associated with chronic mountain sickness in Andean population. High Alt Med Biol. 15:146–154, 2014.—A study of chronic mountain sickness (CMS) with a candidate gene—vascular endothelial growth factor A (VEGFA)—was carried out in a Peruvian population l...

  3. ObStruct: a method to objectively analyse factors driving population structure using Bayesian ancestry profiles.

    Directory of Open Access Journals (Sweden)

    Velimir Gayevskiy

    Full Text Available Bayesian inference methods are extensively used to detect the presence of population structure given genetic data. The primary output of software implementing these methods are ancestry profiles of sampled individuals. While these profiles robustly partition the data into subgroups, currently there is no objective method to determine whether the fixed factor of interest (e.g. geographic origin correlates with inferred subgroups or not, and if so, which populations are driving this correlation. We present ObStruct, a novel tool to objectively analyse the nature of structure revealed in Bayesian ancestry profiles using established statistical methods. ObStruct evaluates the extent of structural similarity between sampled and inferred populations, tests the significance of population differentiation, provides information on the contribution of sampled and inferred populations to the observed structure and crucially determines whether the predetermined factor of interest correlates with inferred population structure. Analyses of simulated and experimental data highlight ObStruct's ability to objectively assess the nature of structure in populations. We show the method is capable of capturing an increase in the level of structure with increasing time since divergence between simulated populations. Further, we applied the method to a highly structured dataset of 1,484 humans from seven continents and a less structured dataset of 179 Saccharomyces cerevisiae from three regions in New Zealand. Our results show that ObStruct provides an objective metric to classify the degree, drivers and significance of inferred structure, as well as providing novel insights into the relationships between sampled populations, and adds a final step to the pipeline for population structure analyses.

  4. Prevalence of upper gastrointestinal bleeding risk factors among the general population and osteoarthritis patients.

    Science.gov (United States)

    Kim, Sang Hyuck; Yun, Jae Moon; Chang, Chong Bum; Piao, Heng; Yu, Su Jong; Shin, Dong Wook

    2016-12-28

    To assess the prevalence of possible risk factors of upper gastrointestinal bleeding (UGIB) and their age-group specific trend among the general population and osteoarthritis patients. We utilized data from the National Health Insurance Service that included claims data and results of the national health check-up program. Comorbid conditions (peptic ulcer, diabetes, liver disease, chronic renal failure, and gastroesophageal reflux disease), concomitant drugs (aspirin, clopidogrel, cilostazol, non-steroidal anti-inflammatory drugs, steroid, anticoagulants, and SSRI), personal habits (smoking, and alcohol consumption) were considered as possible UGIB risk factors. We randomly imputed the prevalence of infection in the data considering the age-specific prevalence of Helicobacter pylori (H. pylori) infection in Korea. The prevalence of various UGIB risk factors and the age-group specific trend of the prevalence were identified. Prevalence was compared between osteoarthritis patients and others. A total of 801926 subjects (93855 osteoarthritis patients) aged 20 and above were included. The prevalence of individual and concurrent multiple risk factors became higher as the age increased. The prevalence of each comorbid condition and concomitant drug were higher in osteoarthritis patients. Thirty-five point zero two percent of the overall population and 68.50% of osteoarthritis patients had at least one or more risk factors of UGIB. The prevalence of individual and concurrent multiple risk factors in younger age groups were also substantial. Furthermore, when personal habits (smoking, and alcohol consumption) and H. pylori infection were included, the prevalence of concurrent multiple risk factors increased greatly even in younger age groups. Prevalence of UGIB risk factors was high in elderly population, but was also considerable in younger population. Patient with osteoarthritis was at higher UGIB risk than those without osteoarthritis. Physicians should consider

  5. Prevalence of upper gastrointestinal bleeding risk factors among the general population and osteoarthritis patients

    Science.gov (United States)

    Kim, Sang Hyuck; Yun, Jae Moon; Chang, Chong Bum; Piao, Heng; Yu, Su Jong; Shin, Dong Wook

    2016-01-01

    AIM To assess the prevalence of possible risk factors of upper gastrointestinal bleeding (UGIB) and their age-group specific trend among the general population and osteoarthritis patients. METHODS We utilized data from the National Health Insurance Service that included claims data and results of the national health check-up program. Comorbid conditions (peptic ulcer, diabetes, liver disease, chronic renal failure, and gastroesophageal reflux disease), concomitant drugs (aspirin, clopidogrel, cilostazol, non-steroidal anti-inflammatory drugs, steroid, anticoagulants, and SSRI), personal habits (smoking, and alcohol consumption) were considered as possible UGIB risk factors. We randomly imputed the prevalence of infection in the data considering the age-specific prevalence of Helicobacter pylori (H. pylori) infection in Korea. The prevalence of various UGIB risk factors and the age-group specific trend of the prevalence were identified. Prevalence was compared between osteoarthritis patients and others. RESULTS A total of 801926 subjects (93855 osteoarthritis patients) aged 20 and above were included. The prevalence of individual and concurrent multiple risk factors became higher as the age increased. The prevalence of each comorbid condition and concomitant drug were higher in osteoarthritis patients. Thirty-five point zero two percent of the overall population and 68.50% of osteoarthritis patients had at least one or more risk factors of UGIB. The prevalence of individual and concurrent multiple risk factors in younger age groups were also substantial. Furthermore, when personal habits (smoking, and alcohol consumption) and H. pylori infection were included, the prevalence of concurrent multiple risk factors increased greatly even in younger age groups. CONCLUSION Prevalence of UGIB risk factors was high in elderly population, but was also considerable in younger population. Patient with osteoarthritis was at higher UGIB risk than those without osteoarthritis

  6. Risk factors for bacterial vaginosis in pregnancy: a population-based study on Danish women

    DEFF Research Database (Denmark)

    Thorsen, Poul; Vogel, Ida; Molsted, Kirsten

    2006-01-01

    Background. No larger population-based study of bacterial vaginosis in pregnancy has previously been available. The objective of this study was to examine risk factors for bacterial vaginosis in pregnancy. Design. From a prospective population-based cohort of 3,596 eligible pregnant women, 2......, and sociodemographic factors) were computed. Results. At enrolment, bacterial vaginosis was diagnosed in 13.7% of Danish pregnant women. Significant risk factors for bacterial vaginosis were: daily coitus (adjusted relative risk 2.09 [1.43-3.04]), being single (1.76 [1.21-2.56]), smoking more than 10 cigarettes daily...... at conception (1.59 [1.29-1.93]), previous genital infection with Chlamydia trachomatis or Neisseria gonorrhoeae (1.39 [1.07-1.79]), and consuming 2 or more drinks per week (1.33 [1.02-1.74]) after control for confounding factors. Conclusion. In pregnancy, women who have daily coitus, are single, smokers...

  7. Is static hyperinflation a limiting factor during exercise in adolescents with cystic fibrosis?

    Science.gov (United States)

    Werkman, M S; Hulzebos, H J; Arets, H G M; van der Net, J; Helders, P J M; Takken, T

    2011-02-01

    Increased work of breathing is considered to be a limiting factor in patients with cystic fibrosis (CF) performing aerobic exercise. We hypothesized that adolescents with CF and with static hyperinflation are more prone to a ventilatorily limited exercise capacity than non-static hyperinflated adolescents with CF. Exercise data of 119 adolescents with CF [range 12-18 years], stratified for static hyperinflation, defined as ratio of residual volume to total lung capacity (RV/TLC) > 30%, were obtained during a progressive bicycle ergometer test with gas analysis and analyzed for ventilatory limitation. Static hyperinflation showed a significant, though weak association (Φ 0.38; P 0.70; FEV(1)  hyperinflation showed an increase to Φ 0.49 (P  50%. In adolescents with static hyperinflation, peak work rate (W(peak) ; 3.1 ± 0.7 W/kg (75.1 ± 17.3% of predicted), peak oxygen uptake (VO(2peak) /kg (ml/min/kg); 39.2 ± 9.2 ml/min/kg (91.0 ± 20.3% of predicted), peak heart rate (HR(peak) ; 176 ± 19 beats/min) were significantly (P hyperinflated adolescents (W(peak) 3.5 ± 0.5 W/kg (81.4 ± 10.0% of predicted)); VO(2peak) /kg (ml/min/kg); 43.1 ± 7.5 ml/min/kg (98.0 ± 15.1% of predicted); and HR(peak) 185 ± 14 beats/min). Additionally, no difference was found in the degree of association of FEV(1) (%) and RV/TLC (%) with VO(2peak) /kg(pred) and W(peak) /kg(Pred) , but we found the RV/TLC (%) to be a slightly stronger predictor of VO(2peak) /kg(pred) and W(peak) /kg(Pred) than FEV(1) (%). These results indicate that the presence of static hyperinflation in adolescents with CF by itself does not strongly influence ventilatory constraints during exercise and that static hyperinflation is only a slightly stronger predictor of W(peak) /kg(Pred) and VO(2peak) /kg(Pred) than airflow obstruction (FEV(1) (%)).

  8. Body image and body change: Predictive factors in an Iranian population

    OpenAIRE

    Behshid Garrusi; Saeide Garousi; Baneshi, Mohammad R.

    2013-01-01

    Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultura...

  9. Eating Disorders and Their Associated Risk Factors among Iranian Population – A Community Based Study

    OpenAIRE

    Garrusi, Behshid; Baneshi, Mohammad Reza

    2012-01-01

    Backgrounds: Many socio cultural variables could be affect eating disorders in Asian countries. In Iran, there are few researches regarding eating disorders and their contributing factors. The aim of this study is to explore frequency of eating disorders and their risk factors in an Iranian population. Materials and Methods: About 1204 participants were selected aged between fourteen to 55 years. Frequency of eating disorders and effects of variables such as demographic characteristics, Body ...

  10. A population pharmacokinetic model for perioperative dosing of factor VIII in hemophilia A patients

    Science.gov (United States)

    Hazendonk, Hendrika; Fijnvandraat, Karin; Lock, Janske; Driessens, Mariëtte; van der Meer, Felix; Meijer, Karina; Kruip, Marieke; Gorkom, Britta Laros-van; Peters, Marjolein; de Wildt, Saskia; Leebeek, Frank; Cnossen, Marjon; Mathôt, Ron

    2016-01-01

    The role of pharmacokinetic-guided dosing of factor concentrates in hemophilia is currently a subject of debate and focuses on long-term prophylactic treatment. Few data are available on its impact in the perioperative period. In this study, a population pharmacokinetic model for currently registered factor VIII concentrates was developed for severe and moderate adult and pediatric hemophilia A patients (FVIII levels hemophilia A patients by Bayesian adaptive dosing. PMID:27390359

  11. The adult spinal cord harbors a population of GFAP-positive progenitors with limited self-renewal potential.

    Science.gov (United States)

    Fiorelli, Roberto; Cebrian-Silla, Arantxa; Garcia-Verdugo, Jose-Manuel; Raineteau, Olivier

    2013-12-01

    Adult neural stem cells (aNSCs) of the forebrain are GFAP-expressing cells that are intercalated within ependymal cells of the subventricular zone (SVZ). Cells showing NSCs characteristics in vitro can also be isolated from the periaqueductal region in the adult spinal cord (SC), but contradicting results exist concerning their glial versus ependymal identity. We used an inducible transgenic mouse line (hGFAP-CreERT2) to conditionally label GFAP-expressing cells in the adult SVZ and SC periaqueduct, and directly and systematically compared their self-renewal and multipotential properties in vitro. We demonstrate that a population of GFAP(+) cells that share the morphology and the antigenic properties of SVZ-NSCs mostly reside in the dorsal aspect of the central canal (CC) throughout the spinal cord. These cells are non-proliferative in the intact spinal cord, but incorporate the S-phase marker EdU following spinal cord injury. Multipotent, clonal YFP-expressing neurospheres (i.e., deriving from recombined GFAP-expressing cells) were successfully obtained from both the intact and injured spinal cord. These spheres however showed limited self-renewal properties when compared with SVZ-neurospheres, even after spinal cord injury. Altogether, these results demonstrate that significant differences exist in NSCs lineages between neurogenic and non-neurogenic regions of the adult CNS. Thus, although we confirm that a population of multipotent GFAP(+) cells co-exists alongside with multipotent ependymal cells within the adult SC, we identify these cells as multipotent progenitors showing limited self-renewal properties.

  12. An investigation to identify potential risk factors associated with common chronic diseases among the older population in India

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    Enemona Emmanuel Adaji

    2017-01-01

    Full Text Available Background: In India, chronic diseases are the leading cause of death and their prevalence has constantly increased over the last decade. Objective: This study aimed to identify risk factors associated with common chronic diseases among people aged 50 years and over in India. Materials and Methods: Data from Wave 1 of the 2007/2008 Indian Study on Global Ageing and Adult Health (SAGE was used to investigate the association between lifestyle choices and chronic diseases using logistic regression. Result: The fully adjusted model showed that significant independent risk factors for angina included area of residence, being diagnosed with diabetes, chronic lung disease (CLD [highest odds ratio (OR 4.77, 95% confidence interval (CI: 2.95-7.70] and arthritis. For arthritis, risk factors included having underlying diabetes, CLD diagnosis, or angina (highest OR 2.32, 95% CI: 1.63-3.31. Risk factors associated with CLD included arthritis, angina (highest OR 4.76, 95% CI: 2.94-7.72, alcohol use, and tobacco use. Risk factors associated with diabetes included level of education, area of residence, socioeconomic status, angina (highest OR 3.59, 95% CI: 2.44-5.29, CLD, arthritis, stroke, and vegetable consumption. Finally, risk factors associated with stroke included diabetes and angina (highest OR 3.34, 95% CI: 1.72-6.50. The presence of any other comorbidity was significantly associated with all five chronic diseases studied. Conclusion: The results show that within the older population, the contribution of lifestyle risk factors to the common chronic diseases investigated in this study was limited. Our findings showed that the major health issue within the study population was multimorbidity.

  13. Risk factors associated with symptomatic cholelithiasis in Taiwan: a population-based study.

    Science.gov (United States)

    Hung, Shih-Chang; Liao, Kuan-Fu; Lai, Shih-Wei; Li, Chia-Ing; Chen, Wen-Chi

    2011-10-17

    Cholelithiasis has become a major health problem in Taiwan. The predominant type of gallstone found in Asian populations differs from that in the West, indicating possible differences in the etiology and risk factors for cholelithiasis. The aim of this study is to investigate the risk factors for cholelithiasis using data representative of the general population. We performed a population-based, case-control study in which we analyzed medical data for 3725 patients newly diagnosed with cholelithiasis and 11175 gender- and age-matched controls with no history of cholelithiasis, using information obtained from the 2005 Registry for Beneficiaries of the National Health Insurance Research Database. Coexisting medical conditions were included in the analysis. Relative risks were estimated by adjusted odds ratio (OR) and 95% confidence interval (CI) using a multivariate logistic regression analysis. After controlling for the other covariates, multivariate logistic regression analysis identified the following as risk factors for cholelithiasis (in descending order of contribution): Among all patients - hepatitis C (OR = 2.78), cirrhosis (OR = 2.47), hepatitis B (OR = 2.00), obesity (OR = 1.89), and hyperlipidemia (OR = 1.54); Among women - hepatitis C (OR = 3.05), cirrhosis (OR = 1.92), obesity (OR = 1.91), menopause (OR = 1.61), hepatitis B (OR = 1.54), and hyperlipidemia (OR = 1.49). Diabetes mellitus appeared to have a marked influence on the development of cholelithiasis but was not identified as a significant independent risk factor for cholelithiasis. The risk factors for cholelithiasis were obesity, hyperlipidemia, hepatitis B infection, hepatitis C infection, and cirrhosis in both genders, and menopause in females. Despite differences in the predominate type of gallstone in Asian versus Western populations, we identified no unique risk factors among the population of Taiwan.

  14. Pregnancy is not a risk factor for gallstone disease: Results of a randomly selected population sample

    Institute of Scientific and Technical Information of China (English)

    Thomas Walcher; Bernhard Otto Boehm; Wolfgang Kratzer; Mark Martin Haenle; Martina Kron; Birgit Hay; Richard Andrew Mason; Alexa Friederike Alice von Schmiesing; Armin Imhof; Wolfgang Koenig; Peter Kern

    2005-01-01

    AIM: To investigate the prevalence, risk factors, and selection of the study population for cholecystolithiasis in an urban population in Germany, in relation to our own findings and to the results in the international literature.METHODS: A total of 2 147 persons (1 111 females,age 42.8±12.7 years; 1 036 males, age 42.3±13.1 years)participating in an investigation on the prevalence of Echinococcus multilocularis were studied for risk factors and prevalence of gallbladder stone disease.Risk factors were assessed by means of a standardized interview and calculation of body mass index (BMI). A diagnostic ultrasound examination of the gallbladder was performed. Data were analyzed by multiple logistic regression, using the SAS statistical software package.RESULTS: Gallbladder stones were detected in 171study participants (8.0%, n = 2 147). Risk factors for the development of gallbladder stone disease included age, sex, BMI, and positive family history. In a separate analysis of female study participants, pregnancy (yes/no)and number of pregnancies did not exert any influence.CONCLUSION: Findings of the present study confirm that age, female sex, BMI, and positive family history are risk factors for the development of gallbladder stone disease. Pregnancy and the number of pregnancies,however, could not be shown to be risk factors. There seem to be no differences in the respective prevalence for gallbladder stone disease in urban and rural populations.

  15. Sex differences in risk factors for coronary heart disease: a study in a Brazilian population

    Directory of Open Access Journals (Sweden)

    Oliveira Helena CF

    2001-04-01

    Full Text Available Abstract Background In Brazil coronary heart disease (CHD constitutes the most important cause of death in both sexes in all the regions of the country and interestingly, the difference between the sexes in the CHD mortality rates is one of the smallest in the world because of high rates among women. Since a question has been raised about whether or how the incidence of several CHD risk factors differs between the sexes in Brazil the prevalence of various risk factors for CHD such as high blood cholesterol, diabetes mellitus, hypertension, obesity, sedentary lifestyle and cigarette smoking was compared between the sexes in a Brazilian population; also the relationships between blood cholesterol and the other risk factors were evaluated. Results The population presented high frequencies of all the risk factors evaluated. High blood cholesterol (CHOL and hypertension were more prevalent among women as compared to men. Hypertension, diabetes and smoking showed equal or higher prevalence in women in pre-menopausal ages as compared to men. Obesity and physical inactivity were equally prevalent in both sexes respectively in the postmenopausal age group and at all ages. CHOL was associated with BMI, sex, age, hypertension and physical inactivity. Conclusions In this population the high prevalence of the CHD risk factors indicated that there is an urgent need for its control; the higher or equal prevalences of several risk factors in women could in part explain the high rates of mortality from CHD in females as compared to males.

  16. Salinity gradient of the Baltic Sea limits the reproduction and population expansion of the newly invaded comb jelly Mnemiopsis leidyi.

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    Cornelia Jaspers

    Full Text Available The recent invasion of the comb jelly Mnemiopsis leidyi into northern European waters is of major public and scientific concern. One of the key features making M. leidyi a successful invader is its high fecundity combined with fast growth rates. However, little is known about physiological limitations to its reproduction and consequent possible abiotic restrictions to its dispersal. To evaluate the invasion potential of M. leidyi into the brackish Baltic Sea we studied in situ egg production rates in different regions and at different salinities in the laboratory, representing the salinity gradient of the Baltic Sea. During October 2009 M. leidyi actively reproduced over large areas of the Baltic Sea. Egg production rates scaled with animal size but decreased significantly with decreasing salinity, both in the field (7-29 and in laboratory experiments (6-33. Temperature and zooplankton, i.e. food abundance, could not explain the observed differences. Reproduction rates at conditions representing the Kattegat, south western and central Baltic Sea, respectively, were 2.8 fold higher at the highest salinities (33 and 25 than at intermediate salinities (10 and 15 and 21 times higher compared from intermediate to the lowest salinity tested (6. Higher salinity areas such as the Kattegat, and to a lower extent the south western Baltic, seem to act as source regions for the M. leidyi population in the central Baltic Sea where a self-sustaining population, due to the low salinity, cannot be maintained.

  17. Salinity gradient of the Baltic Sea limits the reproduction and population expansion of the newly invaded comb jelly Mnemiopsis leidyi.

    Science.gov (United States)

    Jaspers, Cornelia; Møller, Lene Friis; Kiørboe, Thomas

    2011-01-01

    The recent invasion of the comb jelly Mnemiopsis leidyi into northern European waters is of major public and scientific concern. One of the key features making M. leidyi a successful invader is its high fecundity combined with fast growth rates. However, little is known about physiological limitations to its reproduction and consequent possible abiotic restrictions to its dispersal. To evaluate the invasion potential of M. leidyi into the brackish Baltic Sea we studied in situ egg production rates in different regions and at different salinities in the laboratory, representing the salinity gradient of the Baltic Sea. During October 2009 M. leidyi actively reproduced over large areas of the Baltic Sea. Egg production rates scaled with animal size but decreased significantly with decreasing salinity, both in the field (7-29) and in laboratory experiments (6-33). Temperature and zooplankton, i.e. food abundance, could not explain the observed differences. Reproduction rates at conditions representing the Kattegat, south western and central Baltic Sea, respectively, were 2.8 fold higher at the highest salinities (33 and 25) than at intermediate salinities (10 and 15) and 21 times higher compared from intermediate to the lowest salinity tested (6). Higher salinity areas such as the Kattegat, and to a lower extent the south western Baltic, seem to act as source regions for the M. leidyi population in the central Baltic Sea where a self-sustaining population, due to the low salinity, cannot be maintained.

  18. TGF-alpha genotypes, oral clefts, and environmental risk factors: A population-based California study

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, G.M.; Wasserman, C.R. [CA Birth Defects Monitoring Program, Emeryville, CA (United States); Lammer, E.J. [Stanford Univ., Palo Alto, CA (United States)] [and others

    1994-09-01

    Several studies have shown a relation between genetic variation at the TGF-alpha locus and oral clefts. These studies had limited sample sizes and also lacked data on additional factors potentially related to clefting. We investigated the influence on clefting from risk factors, such as maternal smoking, dependent on TFG-alpha genotype. This was accomplished using a large population-bases case-control study of fetuses and liveborn infants with oral clefts among a 1987-89 cohort of California births (N=548,844). To obtain data on potential risk factors, telephone interviews were conducted with mothers of 731 (84.5% of eligible) cleft cases, and 734 (78.2%) nonmalformed controls. DNA was obtained from newborn screening bloodspots and genotyped by using SSCP designed to detect the Taq1 RFLP. Among mothers who completed an interview, genotyping results were available for 571 (78.1%) cases and 640 (87.2%) controls. Compared to controls, the risk estimate for TGF-alpha polymorphism as measured by the odds ratio was: 0.99 (95% confidence interval 0.64, 1.5) for isolated cleft lip {plus_minus}palate; 0.88 (0.33, 2.2) for nonisolated cleft lip {plus_minus}palate; 1.6 (0.94, 2.8) for isolated cleft palate; 1.9 (0.82, 4.3) for nonisolated cleft palate; and 2.2 (0.99, 5.0) for clefts with known etiology. This dataset also revealed 1.4 to 2-fold increased risks for maternal cigarette smoking > 19 cigs/day in early pregnancy. Among these heavy smokers, risk of clefting was even more increased for infants with the TGF-alpha polymorphism. Our data suggest an association between the TGF-alpha uncommon allele and some phenotypic subgroups as well as provide evidence for a genetic-environment interaction between maternal smoking and the variant in the etiology of clefting. The fraction of cases possibly attributed to this interaction, however, was small.

  19. Cardiovascular risk factors in a Mexican middle-class urban population. The Lindavista Study. Baseline data.

    Science.gov (United States)

    Meaney, Alejandra; Ceballos-Reyes, Guillermo; Gutiérrez-Salmean, Gabriela; Samaniego-Méndez, Virginia; Vela-Huerta, Agustín; Alcocer, Luis; Zárate-Chavarría, Elisa; Mendoza-Castelán, Emma; Olivares-Corichi, Ivonne; García-Sánchez, Rubén; Martínez-Marroquín, Yolanda; Ramírez-Sánchez, Israel; Meaney, Eduardo

    2013-01-01

    The aim of this communication is to describe the cardiovascular risk factors affecting a Mexican urban middle-class population. A convenience sample of 2602 middle class urban subjects composed the cohort of the Lindavista Study, a prospective study aimed to determine if conventional cardiovascular risks factors have the same prognosis impact as in other populations. For the baseline data, several measurements were done: obesity indexes, smoking, blood pressure, fasting serum glucose, total cholesterol, HDL-c, LDL-c and triglycerides. This paper presents the basal values of this population, which represents a sample of the Mexican growing urban middle-class. The mean age in the sample was 50 years; 59% were females. Around 50% of the entire group were overweighed, while around 24% were obese. 32% smoked; 32% were hypertensive with a 20% rate of controlled pressure. 6% had diabetes, and 14% had impaired fasting glucose; 66% had total cholesterol ≥ 200 mg/dL; 62% showed HDL-c levels150 mg/dL, and 34% levels of LDL-c ≥ 160 mg/dL. Half of the population studied had the metabolic syndrome. These data show a population with a high-risk profile, secondary to the agglomeration of several cardiovascular risk factors. Copyright © 2012 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  20. Co-infection and risk factors of tuberculosis in a Mexican HIV+ population

    Directory of Open Access Journals (Sweden)

    Roberto Zenteno-Cuevas

    2011-06-01

    Full Text Available INTRODUCTION: The situation of tuberculosis (TB is being modified by the human immunodeficiency virus (HIV, which is increasing the occurrence of new cases and the generation of drug resistant strains, affecting not only the people infected with HIV, but also their close contacts and the general population, conforming a serious public health concern. However, the magnitudes of the factors associated to this co-infection differ considerably in relation to the population groups and geographical areas. METHODS: In order to evaluate the prevalence and risk factors for the co-infection of tuberculosis (TB in a population with human immunodeficiency virus (HIV+ in the Southeast of Mexico, we made the analysis of clinical and epidemiological variables and the diagnosis of tuberculosis by isolation of mycobacteria from respiratory samples. RESULTS: From the 147 HIV+ individuals analyzed, 12 were culture positive; this shows a prevalence of 8% for the co-infection. The only variable found with statistical significance for the co-infection was the number of CD4-T < 200 cells/mm³, OR 13 (95%, CI 2-106 vs 12-109. CONCLUSIONS: To our knowledge this is the first report describing the factors associated with tuberculosis co -infection with HIV in a population from Southern Mexico. The low number of CD4 T-cells was the only variable associated with the TB co-infection and the rest of the variables provide scenarios that require specific and particular interventions for this population group.

  1. Transport and homeostasis of potassium and phosphate: limiting factors for sustainable crop production.

    Science.gov (United States)

    Luan, Mingda; Tang, Ren-Jie; Tang, Yumei; Tian, Wang; Hou, Congong; Zhao, Fugeng; Lan, Wenzhi; Luan, Sheng

    2017-06-01

    Potassium (K) and phosphate (Pi) are both macronutrients essential for plant growth and crop production, but the unrenewable resources of phosphorus rock and potash have become limiting factors for food security. One critical measure to help solve this problem is to improve nutrient use efficiency (NUE) in plants by understanding and engineering genetic networks for ion uptake, translocation, and storage. Plants have evolved multiple systems to adapt to various nutrient conditions for growth and production. Within the NUE networks, transport proteins and their regulators are the primary players for maintaining nutrient homeostasis and could be utilized to engineer high NUE traits in crop plants. A large number of publications have detailed K+ and Pi transport proteins in plants over the past three decades. Meanwhile, the discovery and validation of their regulatory mechanisms are fast-track topics for research. Here, we provide an overview of K+ and Pi transport proteins and their regulatory mechanisms, which participate in the uptake, translocation, storage, and recycling of these nutrients in plants. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. Embracing the emerging precision agriculture technologies for site-specific management of yield-limiting factors.

    Science.gov (United States)

    Melakeberhan, H

    2002-09-01

    Precision agriculture (PA) is providing an information revolution using Global Positioning (GPS) and Geographic Information (GIS) systems and Remote Sensing (RS). These technologies allow better decision making in the management of crop yield-limiting biotic and abiotic factors and their interactions on a site-specific (SSM) basis in a wide range of production systems. Characterizing the nature of the problem(s) and public education are among the challenges that scientists, producers, and industry face when adapting PA technologies. To apply SSM, spatio-temporal characteristics of the problem(s) need to be determined and variations within a field demonstrated. Spatio-temporal characteristics of a given pathogen or pest problem may be known but may not be the only or primary cause of the problem. Hence, exact cause-and-effect relationships need to be established by incorporating GIS, GPS, and RS-generated data as well as possible interactions. Exploiting the potential of PA technologies in sustainable ways depends on whether or not we first ask ''Are we doing the right thing?'' (strategic) as opposed to ''Are we doing it right?'' (tactical).

  3. Factors responsible for the emergence of arboviruses; strategies, challenges and limitations for their control.

    Science.gov (United States)

    Liang, Guodong; Gao, Xiaoyan; Gould, Ernest A

    2015-03-01

    Slave trading of Africans to the Americas, during the 16th to the 19th century was responsible for the first recorded emergence in the New World of two arthropod-borne viruses (arboviruses), yellow fever virus and dengue virus. Many other arboviruses have since emerged from their sylvatic reservoirs and dispersed globally due to evolving factors that include anthropological behaviour, commercial transportation and land-remediation. Here, we outline some characteristics of these highly divergent arboviruses, including the variety of life cycles they have developed and the mechanisms by which they have adapted to evolving changes in habitat and host availability. We cite recent examples of virus emergence that exemplify how arboviruses have exploited the consequences of the modern human lifestyle. Using our current understanding of these viruses, we also attempt to demonstrate some of the limitations encountered in developing control strategies to reduce the impact of future emerging arbovirus diseases. Finally, we present recommendations for development by an international panel of experts reporting directly to World Health Organization, with the intention of providing internationally acceptable guidelines for improving emerging arbovirus disease control strategies. Success in these aims should alleviate the suffering and costs encountered during recent decades when arboviruses have emerged from their sylvatic environment.

  4. Theory of factors limiting high gradient operation of warm accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Nusinovich, Gregory S. [University of Maryland; Antonsen, Thomas M. [University of Maryland; Kishek, Rami [University of Maryland

    2014-07-25

    This final report summarizes the research performed during the time period from 8/1/2010 to 7/31/2013. It consists of two parts describing our studies in two directions: (a) analysis of factors limiting operation of dielectric-loaded accelerating (DLA) structures where the main problem is the occurrence of multipactor on dielectric surfaces, and (b) studies of effects associated with either RF magnetic or RF electric fields which may cause the RF breakdown in high-gradient metallic accelerating structures. In the studies of DLA structures, at least, two accomplishments should be mentioned: the development of a 3D non-stationary, self-consistent code describing the multipactor phenomena and yielding very good agreement with some experimental data obtained in joint ANL/NRL experiments. In the metallic structures, such phenomena as the heating and melting of micro-particles (metallic dust) by RF electric and magnetic fields in single-shot and rep-rate regimes is analyzed. Also, such processes in micro-protrusions on the structure surfaces as heating and melting due to the field emitted current and the Nottingham effect are thoroughly investigated with the account for space charge of emitted current on the field emission from the tip.

  5. The prevalence and risk factors for depression symptoms in a rural Chinese sample population.

    Directory of Open Access Journals (Sweden)

    Xinghu Zhou

    Full Text Available BACKGROUND: It is essential to understand how we can prevent and treat the epidemic of depression. Several studies have reported the prevalence of depressive symptoms in the urban population in China, but there is a lack of information regarding the prevalence of depression in rural populations. OBJECTIVE: To understand the prevalence of depression in a rural Chinese population and to analyze the risk factors for depression. METHODS: This study used a cross-sectional approach. A total of 11,473 subjects were surveyed and completed the Patient Health Questionnaire-9 (PHQ-9 and the World Health Organization Quality of Life Brief scales. Living conditions, per capita income, marital status, and information about dietary health and chronic disease status were assessed. RESULTS: The prevalence of depressive symptoms in the population was 5.9%. The prevalence in women (8.1% was higher compared with men (3.5% and also increased with age. The per capita income level, amount of sleep obtained per day, education level, weekly consumption of meat and beans or bean products, salt intake, and chronic disease status were associated with depressive symptoms. The quality of life of individuals with a score less than 10 points on the PHQ-9 was significantly better compared with individuals with a score greater than 10. CONCLUSION: The prevalence of depressive symptoms among rural population is higher than some southern cities in China. Dietary patterns may be an important risk factor linked to this disorder in the Chinese rural population.

  6. Association of tumor necrosis factor polymorphisms with susceptibility to ulcerative colitis in Chinese Han population

    Institute of Scientific and Technical Information of China (English)

    曹倩

    2006-01-01

    Objective To investigate the association between tumor necrosis factor(TNF) promoter polymorphisms and susceptibility to ulcerative colitis (UC) in the Chinese Han population. Methods Blood samples from 110 unrelated UC patients and 292 healthy controls from Zhejiang Province, Eastern China were studied. Genotyping for 6 common TNF promoter polymorphisms (TNF-

  7. Factors Associated with Recovery from Anorexia Nervosa : A Population-Based Study

    NARCIS (Netherlands)

    Keski-Rahkonen, Anna; Raevuori, Anu; Bulik, Cynthia M.; Hoek, Hans W.; Rissanen, Aila; Kaprio, Jaakko

    2014-01-01

    Background: To examine factors associated with the outcome of anorexia nervosa among women from the general population. Method: Women (N = 2,881) from the 1975-1979 birth cohorts of Finnish twins were screened for lifetime DSM-IV anorexia nervosa (N = 55 cases) using questionnaires and the SCID inte

  8. Increased sperm count may account for high population frequency of factor V Leiden

    NARCIS (Netherlands)

    D.M. Cohn; S. Repping; H.R. Büller; J.C.M. Meijers; S. Middeldorp

    2010-01-01

    Background: Factor V Leiden (FVL) increases the risk of venous thrombosis and pregnancy loss in carriers. Nevertheless, this relatively old mutation is prevalent in Caucasion populations, which could be explained by positive selection pressure. Men with FVL have previously been found to have higher

  9. RENO, NV, JANUARY 15, 2004: FACTORS IMPLICATED IN AMPHIBIAN POPULATION DECLINES IN THE UNITED STATES

    Science.gov (United States)

    Factors known or suspected to be adversely affecting native amphibian populations in the US were identified using information from 267 species accounts written in a standardized format by multiple authors in the forthcoming book, 'Status and Conservation of U.S. Amphibians'. Spec...

  10. Risk Factors and Consequences of Cortical Thickness in an Asian Population

    NARCIS (Netherlands)

    Hilal, S.; Xin, X.; Ang, S.L.; Tan, C.S.; Venketasubramanian, N.; Niessen, W.J.; Vrooman, H.; Wong, T.Y.; Chen, C.; Ikram, M.K.

    2015-01-01

    Cortical thickness has been suggested to be one of the most important markers of cortical atrophy. In this study, we examined potential risk factors of cortical thickness and its association with cognition in an elderly Asian population from Singapore. This is a cross-sectional study among 572 Chi

  11. A population pharmacokinetic model for perioperative dosing of factor VIII in hemophilia A patients

    NARCIS (Netherlands)

    Hazendonk, Hendrika; Fijnvandraat, Karin; Lock, Janske; Driessens, Mariette; van der Meer, Felix; Meijer, Karina; Kruip, Marieke; Laros-van Gorkom, Britta; Peters, Marjolein; de Wildt, Saskia; Leebeek, Frank; Cnossen, Marjon; Mathot, Ron

    2016-01-01

    The role of pharmacokinetic-guided dosing of factor concentrates in hemophilia is currently a subject of debate and focuses on long-term prophylactic treatment. Few data are available on its impact in the perioperative period. In this study, a population pharmacokinetic model for currently registere

  12. Recurrent bacteraemia: A 10-year regional population-based study of clinical and microbiological risk factors

    DEFF Research Database (Denmark)

    Jensen, U.S.; Knudsen, J.D.; Andersen, Christian Østergaard

    2010-01-01

    Background: A population-based nested case-control study was conducted in order to characterize patient factors and microbial species associated with recurrent bacteraemia. Methods: All patients with bacteraemia in a Danish region during 1996-2006 were investigated. Recurrence was defined based o...

  13. Increased sexually transmitted infection incidence in a low risk population: identifying the risk factors.

    LENUS (Irish Health Repository)

    Shiely, Frances

    2010-04-01

    Between 1994 and 2006, the incidence of sexually transmitted infections (STIs) in Ireland has increased by over 300%. Recent literature would suggest that this figure is an underestimation of the true scale of infection. Our objective was to determine the risk factors associated with STI diagnosis in a population with a rapidly increasing STI incidence.

  14. [Factors of individual radiation sensitivity in caries prevalence in population of radiation polluted regions].

    Science.gov (United States)

    Sevbitov, A V; Skatova, E A

    2005-01-01

    Analysing dental diseases prevalence in population of radiation polluted regions after the Chernobyl accident, one should take into account not only the level of the soil contamination with radionuclides but also factors of individual sensitivity to radioactivity, main of which is the age of the exposed person.

  15. META-ANALYSIS OF THE LIFE STYLE FACTORS RELEVANT TO ENVIRONMENTAL HAZARDS FOR THE AGING POPULATION

    Science.gov (United States)

    The goal of this U.S. Environmental Protection Agency (EPA) study is to characterize activity patterns, physiological changes, and environmental exposures for the aging population. Meta analysis was performed on more than 2000 reviewed articles to evaluate the lifestyle factors ...

  16. A population pharmacokinetic model for perioperative dosing of factor VIII in hemophilia A patients

    NARCIS (Netherlands)

    Hazendonk, Hendrika; Fijnvandraat, Karin; Lock, Janske; Driessens, Mariette; van der Meer, Felix; Meijer, Karina; Kruip, Marieke; Laros-van Gorkom, Britta; Peters, Marjolein; de Wildt, Saskia; Leebeek, Frank; Cnossen, Marjon; Mathot, Ron

    2016-01-01

    The role of pharmacokinetic-guided dosing of factor concentrates in hemophilia is currently a subject of debate and focuses on long-term prophylactic treatment. Few data are available on its impact in the perioperative period. In this study, a population pharmacokinetic model for currently

  17. Stochastic seasonality and nonlinear density-dependent factors regulate population size in an African rodent

    DEFF Research Database (Denmark)

    Leirs, Herwig; Steneth, Nils Chr.; Nichols, James D.

    1997-01-01

    no information on actual demographic rates(9,10). Here we report on both density-dependent and density-independent effects in a murid rodent pest species, the multimammute rat Mastomys natalensis (Smith, 1834), using statistical capture-recapture models, Both effects occur simultaneously, but we also demonstrate......Ecology has long been troubled by the controversy over how populations are regulated(1,2). Some ecologists focus on the role of environmental effects, whereas others argue that density-dependent feedback mechanisms are central(3-6). The relative importance of both processes is still hotly debated......, but clear examples of both processes acting in the same population are rare(7,8). Key-factor analysis (regression of population changes on possible causal factors) and time-series analysis are often used to investigate the presence of density dependence, but such approaches may be biased and provide...

  18. Therapeutic targeting of epidermal growth factor receptor in human cancer: successes and limitations%Therapeutic targeting of epidermal growth factor receptor in humancancer: successes and limitations

    Institute of Scientific and Technical Information of China (English)

    Jill Wykosky; Tim Fenton; Frank Furnari; Webster K. Cavenee

    2011-01-01

    Epidermal growth factor receptor (EGFR) is one of the most commonly altered genes in human cancer by way of over-expression, amplification, and mutation. Targeted inhibition of EGFR activity suppresses signal transduction pathways which control tumor cell growth, proliferation, and resistance to apoptosis. Small molecule tyrosine kinase inhibitors and monoclonal antibodies are among the most common EGFR-targeting agents and have been used clinically for treating various malignancies. This review discusses the successes and challenges of targeting EGFR in human cancer. The genetic alterations of EGFR tend to occur more often in some solid tumors than others, as do the mechanisms of resistance to targeted inhibition. The clinical and basic science experiences with these agents thus far have important implications for the future of therapeutic targeting of EGFR.

  19. Using Matrix and Tensor Factorizations for the Single-Trial Analysis of Population Spike Trains.

    Science.gov (United States)

    Onken, Arno; Liu, Jian K; Karunasekara, P P Chamanthi R; Delis, Ioannis; Gollisch, Tim; Panzeri, Stefano

    2016-11-01

    Advances in neuronal recording techniques are leading to ever larger numbers of simultaneously monitored neurons. This poses the important analytical challenge of how to capture compactly all sensory information that neural population codes carry in their spatial dimension (differences in stimulus tuning across neurons at different locations), in their temporal dimension (temporal neural response variations), or in their combination (temporally coordinated neural population firing). Here we investigate the utility of tensor factorizations of population spike trains along space and time. These factorizations decompose a dataset of single-trial population spike trains into spatial firing patterns (combinations of neurons firing together), temporal firing patterns (temporal activation of these groups of neurons) and trial-dependent activation coefficients (strength of recruitment of such neural patterns on each trial). We validated various factorization methods on simulated data and on populations of ganglion cells simultaneously recorded in the salamander retina. We found that single-trial tensor space-by-time decompositions provided low-dimensional data-robust representations of spike trains that capture efficiently both their spatial and temporal information about sensory stimuli. Tensor decompositions with orthogonality constraints were the most efficient in extracting sensory information, whereas non-negative tensor decompositions worked well even on non-independent and overlapping spike patterns, and retrieved informative firing patterns expressed by the same population in response to novel stimuli. Our method showed that populations of retinal ganglion cells carried information in their spike timing on the ten-milliseconds-scale about spatial details of natural images. This information could not be recovered from the spike counts of these cells. First-spike latencies carried the majority of information provided by the whole spike train about fine-scale image

  20. Ivermectin resistance status and factors associated in Rhipicephalus microplus (Acari: Ixodidae) populations from Veracruz, Mexico.

    Science.gov (United States)

    Fernández-Salas, A; Rodríguez-Vivas, R I; Alonso-Díaz, M A; Basurto-Camberos, H

    2012-11-23

    The objectives of the present study were to (1) determine the status of resistance or susceptibility to ivermectin (IVM) in Rhipicephalus microplus tick populations in Veracruz, Mexico, (2) determine the level of resistance (resistance ratios [RR] and lethal concentrations for 50% [LC(50)] and 99% [LC(99)]) mortality in each R. microplus population, and (3) identify factors associated with resistance. Populations of R. microplus were sampled from 53 cattle farms to evaluate their resistance using the larval immersion test. Mortality data were subjected to probit analysis to calculate LC(50) and LC(99). Resistance ratios were calculated in relation to a susceptible reference strain. A logistic regression model was used to evaluate the relation between resistance and possible associated factors. Thirteen tick populations were susceptible to ivermectin, eighteen had incipient resistance and twenty-two had significant resistance. RR(50) of the susceptible tick populations varied from 0.59 to 1.07. The populations that showed the highest level of resistance were: ANTE (RR(50)=8.21; RR(99)=46.0), PALO (RR(50)=6.25; RR(99)=35.47), P.VIE (RR(50)=5.89; RR(99)=180.3), AURO (RR(50)=5.36; RR(99)=13.82 and CEDR (RR(50)=4.11; RR(99)=26.47). Cattle farms that used macrocyclic lactones ≥ 4 times per year were more likely to develop R. microplus resistant to ivermectin (OR=13.0; p=0.0028). In conclusion, more than two-thirds of the farms sampled in Veracruz, Mexico, showed some level of ivermectin-resistant R. microplus populations and the number of ML applications per year is factor associated with the resistance of R. microplus to IVM.

  1. Using Matrix and Tensor Factorizations for the Single-Trial Analysis of Population Spike Trains.

    Directory of Open Access Journals (Sweden)

    Arno Onken

    2016-11-01

    Full Text Available Advances in neuronal recording techniques are leading to ever larger numbers of simultaneously monitored neurons. This poses the important analytical challenge of how to capture compactly all sensory information that neural population codes carry in their spatial dimension (differences in stimulus tuning across neurons at different locations, in their temporal dimension (temporal neural response variations, or in their combination (temporally coordinated neural population firing. Here we investigate the utility of tensor factorizations of population spike trains along space and time. These factorizations decompose a dataset of single-trial population spike trains into spatial firing patterns (combinations of neurons firing together, temporal firing patterns (temporal activation of these groups of neurons and trial-dependent activation coefficients (strength of recruitment of such neural patterns on each trial. We validated various factorization methods on simulated data and on populations of ganglion cells simultaneously recorded in the salamander retina. We found that single-trial tensor space-by-time decompositions provided low-dimensional data-robust representations of spike trains that capture efficiently both their spatial and temporal information about sensory stimuli. Tensor decompositions with orthogonality constraints were the most efficient in extracting sensory information, whereas non-negative tensor decompositions worked well even on non-independent and overlapping spike patterns, and retrieved informative firing patterns expressed by the same population in response to novel stimuli. Our method showed that populations of retinal ganglion cells carried information in their spike timing on the ten-milliseconds-scale about spatial details of natural images. This information could not be recovered from the spike counts of these cells. First-spike latencies carried the majority of information provided by the whole spike train about fine

  2. Two decades of demography reveals that seed and seedling transitions limit population persistence in a translocated shrub

    National Research Council Canada - National Science Library

    Gross, C L; Mackay, D

    2014-01-01

    .... From 27 populations, 98 cohorts were followed and matrix models of transitions from seeds to adults were used to evaluate the intrinsic rate of population growth against disturbance histories. Ten populations (38 cohorts...

  3. Age and gender might influence big five factors of personality: a preliminary report in Indian population.

    Science.gov (United States)

    Magan, Dipti; Mehta, Manju; Sarvottam, Kumar; Yadav, Raj Kumar; Pandey, R M

    2014-01-01

    Age and gender are two important physiological variables which might influence the personality of an individual. The influence of age and gender on big five personality domains in Indian population was assessed in this cross-sectional study that included 155 subjects (female = 76, male = 79) aged from 16-75 years. Big five personality factors were evaluated using 60-item NEO-Five Factor Inventory (NEO-FFI) at a single point in time. Among the big five factors of personality, Conscientiousness was positively correlated (r = 0.195; P personality traits might change with age, and is gender-dependent.

  4. Herbicide resistance in German and Swiss Lolium spp. populations – resistance factors and cross-resistance spectrum

    Directory of Open Access Journals (Sweden)

    Petersen, Jan

    2016-02-01

    Full Text Available In monitoring trials investigating the occurrence and spread of herbicide resistance in German and Swiss Lolium populations 26 samples could be included since 2008. Biotypes which showed resistance to postemergence herbicides were included into a detailed greenhouse trial in 2014. Based on dose-response experiments, resistance factors and cross resistance patterns for cycloxydim, flufenacet, glyphosate, iodosulfuron, meso- and iodosulfuron, pinoxaden and pyroxsulam could be determined. Resistance to ALS as well as ACCase inhibitors was found. In a few cases also resistance to flufenacet could be detected. In contrast, no resistance to glyphosate was discovered. Resistant populations were found in four German federal states (Hessen, Mecklenburg-Vorpommern, Sachsen and Schleswig-Holstein. Two populations were resistant to all cereal selective post-emergence herbicides and to flufenacet. Some populations from Switzerland indicated presence of ACCase inhibitor resistance. In the future, more problems with herbicide resistant Lolium species as weeds in cereals may arise due to limited amount of available selective herbicides and climatic change with more favourable conditions for Lolium spp. as weeds.

  5. Factors Associated with Noncompletion of Latent Tuberculosis Infection Treatment in an Inner-City Population in Edmonton, Alberta

    Directory of Open Access Journals (Sweden)

    Kathy Malejczyk

    2014-01-01

    Full Text Available A limited number of studies have been published that examine treatment completion rates and interventions used to increase treatment completion within an inner-city population. The purpose of the present study was to determine the rate of latent tuberculosis infection (LTBI treatment completion in an inner-city population in Edmonton, Alberta, and to identify factors that correlated with treatment completion. A retrospective chart review was conducted involving patients who started LTBI treatment between January 1, 2005 and December 31, 2010 in Edmonton’s inner city. A total of 77 patients started treatment and 57 (74% patients completed LTBI treatment. Homelessness was the only variable that was significantly associated with incomplete treatment (OR 8.0 [95% CI 1.4 to 45.6] and it remained significant when controlling for drug use (adjusted OR 6.5 [95% CI 1.1 to 38.8]. While the present study demonstrated treatment completion rates comparable with or better than those described in the general population, it highlighted the need for continued emphasis on interventions aimed at improving outcomes within homeless populations.

  6. The use of audience response system technology with limited-english-proficiency, low-literacy, and vulnerable populations.

    Science.gov (United States)

    Keifer, Matthew C; Reyes, Iris; Liebman, Amy K; Juarez-Carrillo, Patricia

    2014-01-01

    Audience response systems (ARS) have long been used to improve the interactivity of educational activities. Most studies of ARS have addressed education of literate trainees. How well these devices work with low-literacy subjects is not well studied. Information gathering on the training audience is an important use of ARS and helpful in improving the targeting of training information. However, obtaining demographic information from vulnerable populations with reasons to be concerned about divulging information about themselves has not been tested. In addition, a culturally competent method to effectively collect demographic and evaluation data of this growing population is essential. This project investigated the use of ARS to gather information from Hispanic immigrant workers, many of whom are socially vulnerable and have limited English proficiency (LEP) and low-literacy. Workers attended focus groups and were asked to use ARS devices or clickers to respond to questions. Questions were both categorical (multiple choice) and open-ended numerical (text entry), and varied from simple queries to more sensitive points regarding immigration. Most workers answered the one-key response categorical questions with little difficulty. In contrast, some participants struggled when responding to numerical questions, especially when the response required pressing multiple clicker keys. An overwhelming majority of participants reported that the clickers were comfortable and easy to use despite the challenges presented by the more complex responses. The error rate increased as question complexity increased and the trend across three ordered categories of response complexity reached statistical significance. Results suggest that ARS is a viable method for gathering dichotomous or higher-order categorical information from LEP and low-literacy populations in a group setting while assuring anonymity. However, it is recommended that clickers be developed and tested with fewer, bigger

  7. Measles outbreaks in displaced populations: a review of transmission, morbidity and mortality associated factors

    Directory of Open Access Journals (Sweden)

    Kamigaki Taro

    2010-03-01

    Full Text Available Abstract Background Measles is a highly contagious infectious disease with a significant public health impact especially among displaced populations due to their characteristic mass population displacement, high population density in camps and low measles vaccination coverage among children. While the fatality rate in stable populations is generally around 2%, evidence shows that it is usually high among populations displaced by disasters. In recent years, refugees and internally displaced persons have been increasing. Our study aims to define the epidemiological characteristics and risk factors associated with measles outbreaks in displaced populations. Methods We reviewed literature in the PubMed database, and selected articles for our analysis that quantitatively described measles outbreaks. Results A total of nine articles describing 11 measles outbreak studies were selected. The outbreaks occurred between 1979 and 2005 in Asia and Africa, mostly during post-conflict situations. Seven of eight outbreaks were associated with poor vaccination status (vaccination coverage; 17-57%, while one was predominantly due to one-dose vaccine coverage. The age of cases ranged from 1 month to 39 years. Children aged 6 months to 5 years were the most common target group for vaccination; however, 1622 cases (51.0% of the total cases were older than 5 years of age. Higher case-fatality rates (>5% were reported for five outbreaks. Consistent factors associated with measles transmission, morbidity and mortality were vaccination status, living conditions, movements of refugees, nutritional status and effectiveness of control measures including vaccination campaigns, surveillance and security situations in affected zones. No fatalities were reported in two outbreaks during which a combination of active and passive surveillance was employed. Conclusion Measles patterns have varied over time among populations displaced by natural and man-made disasters. Appropriate

  8. Genetic structure is determined by stochastic factors in a natural population of Drosophila buzzatii in Argentina.

    Science.gov (United States)

    Vilardi, J C; Hasson, E; Rodriguez, C; Fanara, J J

    1994-01-01

    D. buzzatii is a cactophilic species associated with several cactaceae in Argentina. This particular ecological niche implies that this species is faced with a non-uniform environment constituted by discrete and ephemeral breeding sites, which are colonized by a finite number of inseminated females. The genetic consequences of this population structure upon the second chromosome polymorphism were investigated by means of F-statistics in a natural endemic population of Argentina. The present study suggests that differentiation of inversion frequencies in third instar larvae among breeding sites has taken place mainly at random and selection is not operating to determine the structure of this population. The average number of parents breeding on a single pad seems to be similar to the number colonizing Opuntia ficus indica rotting cladodes in Carboneras, a derived population from Spain. There is no significant excess of heterokaryotypes within pads or in the population as a whole. The results obtained in the present study suggest that the potential role of selective versus stochastic factors relative to the among pad heterogeneity in the population here studied is different from that of the Spanish population previously reported. Potential mechanisms responsible for these differences are discussed.

  9. Heavy-to-Light Form Factors in the Final Hadron Large Energy Limit Covariant Quark Model Approach

    CERN Document Server

    Charles, J; Oliver, L; Pène, O; Raynal, J C

    1999-01-01

    We prove the full covariance of the heavy-to-light weak current matrix elements based on the Bakamjian-Thomas construction of relativistic quark models, in the heavy mass limit for the parent hadron and the large energy limit for the daughter one. Moreover, this quark model representation of the heavy-to-light form factors fulfills the general relations that were recently argued to hold in the corresponding limit of QCD, namely that there are only three independent form factors describing the B -> pi (rho) matrix elements, as well as the factorized scaling law sqrt(M)z(E) of the form factors with respect to the heavy mass M and large energy E. These results constitute another good property of the quark models à la Bakamjian-Thomas, which were previously shown to exhibit covariance and Isgur-Wise scaling in the heavy-to-heavy case.

  10. Aneurismal subarachnoid hemorrhage in a Chilean population, with emphasis on risk factors

    Directory of Open Access Journals (Sweden)

    A Cifuentes Lucía

    2011-10-01

    Full Text Available Abstract Background Subarachnoid Hemorrhage (SAH is caused principally by the rupture of intracranial aneurisms. Important risk factors have been described such as age, sex, hypertension (HT and season of the year, among others. The objective is to investigate the demographic characteristics and possible risk factors in a population of Chilean patients. Methods This retrospective study was based on the analysis of 244 clinical records of patients diagnosed with aneurismal SAH who were discharged from the Instituto de Neurocirugía ASENJO in Santiago, Chile. Results The mean age of patients was 49.85 years and the male:female ratio was 1:2.7. The signs and symptoms were not different between sexes; cephalea (85.7% was predominant, followed by loss of consciousness, vomiting/nausea and meningeal signs. Risk factors included sex, age and HT. Concordant with other reports, the incidence of SAH was greatest in spring. Conclusions The demographic characteristics and risk factors observed in patients with aneurismal SAH treated in ASENJO were comparable to those of other populations. We were not able to conclude that tobacco and alcohol consumption were risk factors for this population.

  11. Integrating Limiting-Factors Analysis with Process-Based Restoration to Improve Recovery of Endangered Salmonids in the Pacific Northwest, USA

    Directory of Open Access Journals (Sweden)

    Derek B. Booth

    2016-04-01

    Full Text Available Two approaches to ecological restoration planning, limiting-factors analysis and process-based restoration, are employed in efforts to recover endangered salmonid species throughout the Pacific Northwest of North America. Limiting-factors analysis seeks to identify physical limitations to fish production that may be addressed by habitat restoration; it is known as the “Field of Dreams” hypothesis (i.e., if you build it, they will come. Process-based restoration, in contrast, assumes that protection and/or restoration of watershed-scale processes will best achieve self-sustaining habitat features that support salmon populations. Two case studies from the Columbia River basin (northwestern USA display current efforts to integrate these two restoration approaches to improve salmonid populations. Although these examples both identify site-specific habitat features to construct, they also recognize the importance of supporting key watershed processes to achieve restoration goals. The challenge in advancing the practice of restoration planning is not in simply acknowledging the conceptual benefits of process-based restoration while maintaining a traditional focus on enumerating site-specific conditions and identifying habitat-construction projects, but rather in following process-based guidance during recovery planning and, ultimately, through implementation of on-the-ground actions. We encourage a realignment of the restoration community to truly embrace a process-based, multi-scalar view of the riverine landscape.

  12. Exploratory factor analysis of self-reported symptoms in a large, population-based military cohort

    Directory of Open Access Journals (Sweden)

    Bliese Paul D

    2010-10-01

    Full Text Available Abstract Background US military engagements have consistently raised concern over the array of health outcomes experienced by service members postdeployment. Exploratory factor analysis has been used in studies of 1991 Gulf War-related illnesses, and may increase understanding of symptoms and health outcomes associated with current military conflicts in Iraq and Afghanistan. The objective of this study was to use exploratory factor analysis to describe the correlations among numerous physical and psychological symptoms in terms of a smaller number of unobserved variables or factors. Methods The Millennium Cohort Study collects extensive self-reported health data from a large, population-based military cohort, providing a unique opportunity to investigate the interrelationships of numerous physical and psychological symptoms among US military personnel. This study used data from the Millennium Cohort Study, a large, population-based military cohort. Exploratory factor analysis was used to examine the covariance structure of symptoms reported by approximately 50,000 cohort members during 2004-2006. Analyses incorporated 89 symptoms, including responses to several validated instruments embedded in the questionnaire. Techniques accommodated the categorical and sometimes incomplete nature of the survey data. Results A 14-factor model accounted for 60 percent of the total variance in symptoms data and included factors related to several physical, psychological, and behavioral constructs. A notable finding was that many factors appeared to load in accordance with symptom co-location within the survey instrument, highlighting the difficulty in disassociating the effects of question content, location, and response format on factor structure. Conclusions This study demonstrates the potential strengths and weaknesses of exploratory factor analysis to heighten understanding of the complex associations among symptoms. Further research is needed to

  13. Awareness of Risk Factors for Breast, Lung and Cervical Cancer in a UK Student Population.

    Science.gov (United States)

    Sherman, Susan M; Lane, Emily L

    2015-12-01

    The objective of this study is to identify levels of risk awareness for breast, lung and cervical cancer, in a UK student population. A sample of male (N=62) and female (N=58) university students, mean age 21.62 years completed a questionnaire identifying which risk factors they knew for each cancer. Analysis of variance was used to compare differences in risk awareness across gender and cancer types. Risk factor awareness was highest for lung cancer (0.78), mid-range for breast cancer (0.61) and lowest for cervical cancer (0.47). Women had greater risk factor awareness (0.67) than males (0.57) across all three cancers. There is also significant belief in mythic risk factors such as stress (from 14 to 40% across the three cancers). Previous research has demonstrated that risk factor awareness increases with educational status, yet even in a university student population, in which the majority of females would have been offered the HPV vaccination, risk factor awareness for cancers is variable. More health education is needed particularly around the risk factors for cervical cancer.

  14. Risk factors for child maltreatment in an Australian population-based birth cohort.

    Science.gov (United States)

    Doidge, James C; Higgins, Daryl J; Delfabbro, Paul; Segal, Leonie

    2017-02-01

    Child maltreatment and other adverse childhood experiences adversely influence population health and socioeconomic outcomes. Knowledge of the risk factors for child maltreatment can be used to identify children at risk and may represent opportunities for prevention. We examined a range of possible child, parent and family risk factors for child maltreatment in a prospective 27-year population-based birth cohort of 2443 Australians. Physical abuse, sexual abuse, emotional abuse, neglect and witnessing of domestic violence were recorded retrospectively in early adulthood. Potential risk factors were collected prospectively during childhood or reported retrospectively. Associations were estimated using bivariate and multivariate logistic regressions and combined into cumulative risk scores. Higher levels of economic disadvantage, poor parental mental health and substance use, and social instability were strongly associated with increased risk of child maltreatment. Indicators of child health displayed mixed associations and infant temperament was uncorrelated to maltreatment. Some differences were observed across types of maltreatment but risk profiles were generally similar. In multivariate analyses, nine independent risk factors were identified, including some that are potentially modifiable: economic disadvantage and parental substance use problems. Risk of maltreatment increased exponentially with the number of risk factors experienced, with prevalence of maltreatment in the highest risk groups exceeding 80%. A cumulative risk score based on the independent risk factors allowed identification of individuals at very high risk of maltreatment, while a score that incorporated all significant risk and protective factors provided better identification of low-risk individuals.

  15. A Bayesian Approach to Identifying New Risk Factors for Dementia: A Nationwide Population-Based Study.

    Science.gov (United States)

    Wen, Yen-Hsia; Wu, Shihn-Sheng; Lin, Chun-Hung Richard; Tsai, Jui-Hsiu; Yang, Pinchen; Chang, Yang-Pei; Tseng, Kuan-Hua

    2016-05-01

    Dementia is one of the most disabling and burdensome health conditions worldwide. In this study, we identified new potential risk factors for dementia from nationwide longitudinal population-based data by using Bayesian statistics.We first tested the consistency of the results obtained using Bayesian statistics with those obtained using classical frequentist probability for 4 recognized risk factors for dementia, namely severe head injury, depression, diabetes mellitus, and vascular diseases. Then, we used Bayesian statistics to verify 2 new potential risk factors for dementia, namely hearing loss and senile cataract, determined from the Taiwan's National Health Insurance Research Database.We included a total of 6546 (6.0%) patients diagnosed with dementia. We observed older age, female sex, and lower income as independent risk factors for dementia. Moreover, we verified the 4 recognized risk factors for dementia in the older Taiwanese population; their odds ratios (ORs) ranged from 3.469 to 1.207. Furthermore, we observed that hearing loss (OR = 1.577) and senile cataract (OR = 1.549) were associated with an increased risk of dementia.We found that the results obtained using Bayesian statistics for assessing risk factors for dementia, such as head injury, depression, DM, and vascular diseases, were consistent with those obtained using classical frequentist probability. Moreover, hearing loss and senile cataract were found to be potential risk factors for dementia in the older Taiwanese population. Bayesian statistics could help clinicians explore other potential risk factors for dementia and for developing appropriate treatment strategies for these patients.

  16. Updating Environmental Media Concentration Limits and Uncertainty factors in the ERICA Tool

    Energy Technology Data Exchange (ETDEWEB)

    Brown, J.E.; Hosseini, A. [Norwegian Radiation Protection Authority, P.O. Box 55, N-1332 Oesteraas (Norway); Alfonso, B.; Avila, R. [Facilia AB, S-167 51 Bromma (Sweden); Beresford, N.A. [Centre for Ecology and Hydrology, CEH-Lancaster, Lancaster Environment Centre, Library Avenue, Bailrigg, Lancaster LA 1 4AP (United Kingdom); Copplestone, D. [Dept. Biological and Environmental Sciences, University of Stirling, Stirling, FK9 4LA (United Kingdom)

    2014-07-01

    Tiered approaches have become a standard means of structuring information in the process of conducting environmental risk assessments. For cases involving the assessment of impacts on wildlife from ionising radiation, the ERICA integrated approach and its supporting software (The ERICA Tool) provides such a structure, splitting the system into two generic screening tiers and a third site-specific tier. The first Tier is very simple, based around Environmental Media Concentration Limits, EMCLs, and requires minimal input from the assessor. The second Tier, although still a screening tier, calculates dose rates and requires more detailed input from the assessor allowing for scrutiny and editing of default parameters in the process. A key element of Tier 2 involves the application of Uncertainty Factors, UFs. Such factors reflect our knowledge concerning probability distribution functions and provide a way of incorporating conservatism into the assessment by considering high percentile values in underlying parameters. Following its launch in 2007, there have been significant developments regarding certain components of the ERICA integrated approach. Most notably, an extended international collation of concentration ratio data has precipitated the need to update parameter values in the Tools databases. In addition, more considered guidance has been developed with regards to filling knowledge gaps in the absence of transfer data. Furthermore, the efficacy of the methods used in assigning probability distribution functions has been questioned leading to an acknowledgement from the developers that the methods were not described in enough detail nor were the justifications for applying the selected approach provided in a convincing way. This has implications for the EMCL values which are derived probabilistically using parameters including concentration ratios. Furthermore, there are implications for UF derivation that relies upon a robust consideration of underlying

  17. Weathering as the limiting factor of denudation in the Western escarpment of the Andes

    Science.gov (United States)

    Abbühl, L. M.; Schlunegger, F.; Kracht, O.; Ramseyer, K.; Rieke-Zapp, D.; Aldahan, A.; von Blanckenburg, F.

    2009-04-01

    additional river profile knickzone in the transition zone between the easterlies and the westerlies. Analysis of 10Be in quartz of river-born sand and of bedrock reveals that denudation correlates positively with the present-day rainfall pattern related to the easterlies. Denudation rates in the headwaters range from 0.14 mm/year in Northern Peru down to 0.05 mm/yr in Northern Chile (Kober et al., 2007). In addition, 10Be-based denudation rates reveal a decreasing trend from the Cordillera to the Pacific coast that positively correlates with the decreasing precipitation rate, irrespective of the nature of the bedrock. Interestingly, the 10Be analysis conducted in the Piura system reveals no influence of the episodic precipitation in relation to El Niño on the sediment production rates. In summary, the pattern of denudation rates together with morphometric observations and quantitative denudation rate estimates strongly hints at weathering being the driving but also limiting factor of denudation. Accordingly, in the western Peruvian Andes, sediment production and export are most probably controlled by the pattern and rate of precipitation. Kober, F., Ivy-Ochs, S., Schlunegger, F., Baur, H., Kubik, P. W., and Wieler, R. (2007). Denudation rates and a topography-driven rainfall threshold in northern Chile: Multiple cosmogenic nuclide data and sediment yield budgets. Geomorphology 83, 97-120.

  18. Effect of abiotic factors on seasonal population dynamics of Lutzomyia longipalpis (Diptera: Psychodidae) in northeastern Brazil.

    Science.gov (United States)

    Ximenes, Maria de Fátima Freire de Melo; Castellón, Eloy G; De Souza, Maria de Fátima; Menezes, Alexandre A Lara; Queiroz, José Wilton; Macedo e Silva, Virgínia Penéllope; Jerônimo, Selma M B

    2006-09-01

    The resurgence of visceral leishmaniasis in Brazil increases the need for studies to elucidate the spatial and temporal dynamics of Lutzomyia longipalpis (Lutz and Neiva) (Diptera: Psychodidae), the vector of Leishmania infantum, the causative agent of visceral leishmaniasis in Brazil. Sand flies were captured in peridomestic habitats biweekly for 3 yr. Cross-correlation tests and spectral analysis were used to analyze the simultaneous and lag-time correlations between Lu. longipalpis population densities and abiotic factors of temperature, relative humidity, wind velocity, and rainfall. Distinct seasonal patterns were observed for males and females, with intervals of 6 mo between population peaks for males and 12 mo for females. Peak female population densities lagged 3 mo behind the maximum annual temperature. Female population density was negatively correlated with relative humidity. An increase in average wind velocity was followed by a decrease in the number of females for 2 wk. Understanding the relationship between the seasonal population dynamics of Lu. longipalpis and abiotic factors will contribute to the design of better control measures to decrease transmission of L. infantum and consequently the incidence of leishmaniasis.

  19. Factors affecting population dynamics of maternally transmitted endosymbionts in Bemisia tabaci.

    Directory of Open Access Journals (Sweden)

    Huipeng Pan

    Full Text Available While every individual of Bemisia tabaci (Hemiptera: Aleyrodidae harbors the primary symbiont (P-symbiont Portiera, the infection frequencies of the six secondary symbionts (S-symbionts including Hamiltonella, Arsenophonus, Cardinium, Wolbachia, Rickettsia and Fritschea vary greatly among different populations. To characterize the factors influencing the infection dynamics of the six S-symbionts in B. tabaci, gene-specific PCR were conducted to screen for the presence of the P-symbiont Portiera and the six S-symbionts in 61 (17 B and 44 Q biotypes field populations collected from different plant species and locations in China. All individuals of the 61 populations hosted the P-symbiont Portiera, but none of them harbored Arsenophonus and Fritschea. The presence and infection rates of Hamiltonella, Cardinium, Rickettsia, Wolbachia and their co-infections Rickettsia + Hamiltonella (RH, Rickettsia + Cardinium (RC, Hamiltonella + Cardinium (HC and Rickettsia + Hamiltonella + Cardinium (RHC varied significantly among the 61 field populations; and the observed variations can be explained by biotypes, sexes, host plants and geographical locations of these field populations. Taken together, at least three factors including biotype, host plant and geographical location affect the infection dynamics of S-symbionts in B. tabaci.

  20. Research on impacts of population-related factors on carbon emissions in Beijing from 1984 to 2012

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yayun; Zhao, Tao; Wang, Yanan, E-mail: wyn3615@126.com; Shi, Zhaohui

    2015-11-15

    Carbon emissions related to population factors have aroused great attention around the world. A multitude of literature mainly focused on single demographic impacts on environmental issues at the national level, and comprehensive studies concerning population-related factors at a city level are rare. This paper employed STIRPAT (Stochastic Impacts by Regression on Population, Affluence and Technology) model incorporating PLS (Partial least squares) regression method to examine the influence of population-related factors on carbon emissions in Beijing from 1984 to 2012. Empirically results manifest that urbanization is the paramount driver. Changes in population age structure have significantly positive impacts on carbon emissions, and shrinking young population, continuous expansion of working age population and aging population will keep on increasing environmental pressures. Meanwhile, shrinking household size and expanding floating population boost the discharge of carbon emissions. Besides, per capita consumption is an important contributor of carbon emissions, while industry energy intensity is the main inhibitory factor. Based upon these findings and the specific circumstances of Beijing, policies such as promoting clean and renewable energy, improving population quality and advocating low carbon lifestyles should be enhanced to achieve targeted emissions reductions. - Highlights: • We employed the STIRPAT model to identify population-related factors of carbon emissions in Beijing. • Urbanization is the paramount driver of carbon emissions. • Changes in population age structure exert significantly positive impacts on carbon emissions. • Shrinking household size, expanding floating population and improving consumption level increase carbon emissions. • Industry energy intensity decreases carbon emissions.

  1. Critical factors in the limited occurrence of the Japanese tree sap mite Hericia sanukiensis (Acari: Astigmata: Algophagidae) inhabiting the sap of the oak Quercus acutissima.

    Science.gov (United States)

    Hayashi, Kyohei; Ichikawa, Toshihide; Yasui, Yukio

    2011-08-01

    Hericia sanukiensis (Astigmata: Algophagidae) is a semi-aquatic mite inhabiting fermented sap flux of the Japanese sawtooth oak (Quercus acutissima) and utilizes Nitidulidae (Coleoptera) as the dispersal (phoretic) carrier. Although nitidulid beetles are commonly found in sap flux, the occurrence of H. sanukiensis has been extremely limited to a few trees in Shikoku Island, Kagawa Prefecture, Japan. To elucidate the critical factors limiting the occurrence of this species, we compared several physical and biological characteristics of sap-exudation points, including the structure and temperature of tree trunks, period and abundance of sap exudation, and seasonal occurrence and dispersal behavior of nitidulid beetles between environments with and without mites. During the two consecutive years of field research, we found that only sap-exudation points with obvious tree holes (ringent area >10 cm², depth >10 cm) had sustained mite populations throughout the observation period. In contrast, for the sap-exudation points lacking tree holes, H. sanukiensis temporally (from spring to autumn) colonized only when the sap production was considerably high. Thus, we suggest that the settlement of H. sanukiensis populations requires tree holes as an overwintering habitat. Nitidulid beetles also concentrated in areas with high sap production and did not disperse from such habitats during the sap flow season. This indicates that H. sanukiensis mites may only disperse and colonize new habitats at very limited opportunities, such as drastic habitat deterioration, which may promote the movement of their carrier. Taken together, these findings may explain the limited occurrence of this mite species.

  2. Evidence-based communications strategies: NWPERLC response to training on effectively reaching limited English-speaking (LEP) populations in emergencies.

    Science.gov (United States)

    DʼAmbrosio, Luann; Huang, Claire E; Sheng Kwan-Gett, Tao

    2014-01-01

    Identifying and overcoming barriers to effective emergency preparedness and response is one of the objectives for the Centers for Disease Control and Prevention's network of 14 Preparedness and Emergency Response Learning Centers (PERLCs) and 9 Preparedness and Response Research Centers (PERRCs). This report describes how a PERLC and a PERRC colocated at the Northwest Center for Public Health Practice responded to Los Angeles County Department of Public Health's (DPH's) request to improve emergency communications with limited English-proficient (LEP) populations. Activities included an assessment of training needs of the DPH preparedness workforce, a training series on social media and community engagement, and a toolkit of evidence-based findings to improve LEP populations' emergency communications and community resilience. Most respondents to the training needs assessment considered themselves essential personnel during an emergency and stated that they have received proper training. Respondents would like to receive further emergency preparedness training, including additional clarity on their role during an emergency. The majority of participants rated the training series as excellent/very good and agreed that they will be able to apply the course content to their work. The percentage of participants who reported confidence in their knowledge and skills related to each course learning objective increased from the precourse survey to the postcourse survey. This article discusses how the colocation of PERRC and PERLC offers efficiencies and expertise to accomplish multicomponent evidence-based requests. The ability to translate research findings quickly into evidence-based training and best practice resources is a strategic benefit to public health practice agencies working on emergency preparedness. LA County DPH was able to use knowledge and lessons learned gained from this work to design and prioritize education and training offerings to improve the capacity

  3. A study of several factors governing the fatigue limits of austempered ductile cast iron with various microstructures

    Science.gov (United States)

    Kim, Jinhak; Kim, Sangtae; Kim, Mingun

    2000-06-01

    The effects the leading factors bearing on fatigue limits were investigated with three kinds of ductile iron specimens various microstructures. As a result of examination, the fatigue limits in relationship to hardness and tensile strength, the expected higher improvement for fatigue limits in the case of the high strength specimens that experienced austempering treatment are not observed in comparison with the specimens treated with stress relief treatment. The estimated maximum defect size is one of the important parameters in predicting and evaluating fatigue limits for three different heat-treated ductile cast irons. Also, a quantitative relationship can be established between the fatigue limit and maximum defect size. Moreover, it is possible to explain the difference in fatigue limits in the three ductile cast irons by application of the rates of non-propagating crack which connects the adjacent graphite nodules before it stops.

  4. Indigenous soil bacteria and low moisture may limit but allow faecal bacteria to multiply and become a minor population in tropical soils

    Science.gov (United States)

    Byappanahalli, M.; Fujioka, R.

    2004-01-01

    The soil environment in Hawaii is generally characterised as sub-optimal but permissive to support the in situ growth of E. coli and enterococci. However, soil desiccation and competition for nutrients by major indigenous soil microflora have been identified as potential factors that could limit a rapid and continual growth of faecal indicator bacteria in this soil environment. Despite these limitations, the genetic capacities of E. coli and enterococci are robust enough to enable these bacteria to become established as minor populations of Hawaii's soil microflora. Although the concentrations of E. coli and enterococci may have represented a fraction of the total soil microbiota, their presence in this habitat was very significant, for two important reasons: (a) soil was a major environmental source of E. coli and enterococci, and (b) the elevated counts of these bacteria in streams that routinely exceeded the EPA standards were due to run-off from soil. As a result, E. coli and enterococci were inadequate indicators to measure the degree of faecal contamination and potential presence of sewage-borne pathogens in Hawaiian streams. ?? IWA Publishing 2004.

  5. Modifiable Coronary Heart Disease Risk Factors in the Population Aged 20-49 Years

    Directory of Open Access Journals (Sweden)

    Francisco Carlos Valladares Mas

    2014-04-01

    Full Text Available Background: evidence provided by the Framingham Heart Study established the critical role of risk factors in the development of coronary heart disease. Over half a century later, current detection and control are still inadequate. Objective: to identify modifiable risk factors of coronary heart disease in individuals aged 20 to 49 years. Methods: a descriptive, cross-sectional study was conducted in 276 individuals from the doctor’s office No. 1 of the Fabio di Celmo Community Teaching Polyclinic in Cienfuegos. Patients were examined in the clinic visit and/or whole family visit. The studied variables included age, sex, skin color, risk factors (excess weight/obesity, physical inactivity, smoking, hypertension, diabetes, dyslipidemia and psychosocial factors, which were obtained from the medical interview, physical examination, laboratory tests (total cholesterol and triglycerides and review of individual medical records and family history. Results: risk factors most frequently identified were excess weight/obesity (42.4 %, physical inactivity (34.4 % and smoking (20.3 %. Presence of these risk factors increased with age, showing differences in the distribution by sex and was associated with psychosocial factors. Their coexistence and progress with age was significant. Conclusion: prevalence of modifiable risk factors for coronary heart disease in a young population was high, with frequent association, predominating factors related to unhealthy lifestyles.

  6. Dietary and lifestyle risk factors for noncommunicable disease among the Mongolian population

    DEFF Research Database (Denmark)

    Bolormaa, Norov; Narantuya, Luvsanbazar; de Courten, Maximilian

    2008-01-01

    blood pressure. In regard to body mass index risk categories, 31.6% (+/- 0.1 CI) of the population aged 15-64 years was overweight and obese. The prevalence of people with impaired fasting glucose (IFG) and elevated blood cholesterol level were 12.5% (+/- 0.05 CI) and 7.0% (+/- 0.01 CI) among 25......-64 years old population. In conclusion, 9 in every 10 people aged 15-64 years had at least one risk factor for developing NCDs. One in every five people had three and more risk factors or was at HIGH risk and in particular, one in every two males aged 45 years and above was at high risk in developing NCDs.......The overall aim is to determine the prevalence of lifestyle related risk factors for noncommunicable disease (NCD) in Mongolia. The prevalence of NCD risk factors was survey in among 15-64 years old population, using the World Health Organization (WHO) STEPwise approach for NCD surveillance...

  7. Prevalence of coronary artery disease risk factors in Iran: a population based survey

    Directory of Open Access Journals (Sweden)

    Gafarzadeh Motlag A

    2007-10-01

    Full Text Available Abstract Background Coronary artery disease (CAD is a leading cause of mortality, morbidity, and disability with high health care cost in Iran. It accounts for nearly 50 percent of all deaths per year. Yet little is known about CAD and CAD risk factors in the Iranian population. We aimed to assess the prevalence of different CAD risk factors in an Iranian population. Methods A descriptive cross sectional survey was conducted involving 3000 healthy adults at 18 years of age or above who were recruited with cluster random sampling. Demographic data and risk factors were determined by taking history, physical examination and laboratory tests. Results The average age was 36.23 ± 15.26. There was 1381 female (46% and 1619 male (54% out of which 6.3% were diabetic, 21.6% were smoker, and 15% had positive familial heart disease history. 61% had total cholesterol level > 200 mg/dL, 32% triglyceride > 200 mg/dl, 47.5% LDL-c > 130 mg/dl, 5.4% HDL-c 140 mmHg, 9.1% diastolic blood pressure > 90 mmHg and 87% of them were physically inactive. Conclusion Clinical and Para-clinical data indicated that Iranian adult population are of a high level of CAD risk factors, which may require urgent decision making to address national control measures regarding CAD.

  8. Biodegradation of petroleum in the marine environment: limiting factors and methods of enhancement

    National Research Council Canada - National Science Library

    Lee, K; Levy, E.M

    1986-01-01

    .... Maximal biodegradation rates are rarely attained under natural environmental conditions, and extensive studies have concluded that the degradation of petroleum in the marine environment is limited...

  9. Prevalence of coagulation factor II G20210A and factor V G1691A Leiden polymorphisms in Chechans, a genetically isolated population in Jordan.

    Science.gov (United States)

    Dajani, Rana; Fatahallah, Raja; Dajani, Abdelrahman; Al-Shboul, Mohammad; Khader, Yousef

    2012-09-01

    Coagulation factor II G20210A and coagulation factor V (Leiden) G1691A single nucleotide polymorphisms (SNPs) are major inherited risk factors of venous thromboembolism. In view of the heterogeneity in their world distribution and lack of sufficient information about their distribution among Chechans, we addressed the prevalence of these SNPs in the Chechan population in Jordan, a genetically isolated population. Factor II G20210A and factor V Leiden SNPs were analysed by polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method and Amplification refractory mutation detection system (ARMS) respectively in 120 random unrelated subjects from the Chechan population in Jordan. Among the subjects studied for factor II G20210A mutation there were three individuals carrying this mutation as heterozygous (one female and two male), giving a prevalence of 2.5 % and an allele frequency of 1.25 %. No homozygous factor II allele was found. Factor V Leiden G1691A mutation was detected as heterozygous in 22 of 120 of individuals (17 female and five male) indicating a prevalence of 18.3 % and allele frequency of 9.2 %. No homozygous allele was found. Our results indicated that prevalence of factor II G20210A mutation in the Chechan population is similar to prevalence in Jordan and Caucasian populations (1-6 %) while the prevalence of factor V Leiden was higher in the Chechan population compared to Jordan and Caucasian populations (2-15 %).

  10. Systematic review of health disparities for cardiovascular diseases and associated factors among American Indian and Alaska Native populations.

    Directory of Open Access Journals (Sweden)

    Rebecca Newlin Hutchinson

    Full Text Available BACKGROUND: American Indians and Alaska Native (AI/AN populations experience significant health disparities compared to non-Hispanic white populations. Cardiovascular disease and related risk factors are increasingly recognized as growing indicators of global health disparities. However, comparative reports on disparities among this constellation of diseases for AI/AN populations have not been systematically reviewed. OBJECTIVES: We performed a literature review on the prevalence of diabetes, metabolic syndrome, dyslipidemia, obesity, hypertension, and cardiovascular disease; and associated morbidity and mortality among AI/AN. DATA SOURCES: A total of 203 articles were reviewed, of which 31 met study criteria for inclusion. Searches were performed on PUBMED, MEDLINE, the CDC MMWR, and the Indian Health Services. STUDY ELIGIBILITY CRITERIA: Published literature that were published within the last fifteen years and provided direct comparisons between AI/AN to non-AI/AN populations were included. STUDY APPRAISAL AND SYNTHESIS METHODS: We abstracted data on study design, data source, AI/AN population, comparison group, and. outcome measures. A descriptive synthesis of primary findings is included. RESULTS: Rates of obesity, diabetes, cardiovascular disease, and metabolic syndrome are clearly higher for AI/AN populations. Hypertension and hyperlipidemia differences are more equivocal. Our analysis also revealed that there are likely regional and gender differences in the degree of disparities observed. LIMITATIONS: Studies using BRFSS telephone surveys administered in English may underestimate disparities. Many AI/AN do not have telephones and/or speak English. Regional variability makes national surveys difficult to interpret. Finally, studies using self-reported data may not be accurate. CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS: Profound health disparities in cardiovascular diseases and associated risk factors for AI/AN populations persist

  11. Population attributable risks of patient, child and organizational risk factors for perinatal mortality in hospital births.

    Science.gov (United States)

    Poeran, Jashvant; Borsboom, Gerard J J M; de Graaf, Johanna P; Birnie, Erwin; Steegers, Eric A P; Bonsel, Gouke J

    2015-04-01

    The main objective of this study was to estimate the contributing role of maternal, child, and organizational risk factors in perinatal mortality by calculating their population attributable risks (PAR). The primary dataset comprised 1,020,749 singleton hospital births from ≥22 weeks' gestation (The Netherlands Perinatal Registry 2000-2008). PARs for single and grouped risk factors were estimated in four stages: (1) creating a duplicate dataset for each PAR analysis in which risk factors of interest were set to the most favorable value (e.g., all women assigned 'Western' for PAR calculation of ethnicity); (2) in the primary dataset an elaborate multilevel logistic regression model was fitted from which (3) the obtained coefficients were used to predict perinatal mortality in each duplicate dataset; (4) PARs were then estimated as the proportional change of predicted- compared to observed perinatal mortality. Additionally, PARs for grouped risk factors were estimated by using sequential values in two orders: after PAR estimation of grouped maternal risk factors, the resulting PARs for grouped child, and grouped organizational factors were estimated, and vice versa. The combined PAR of maternal, child and organizational factors is 94.4 %, i.e., when all factors are set to the most favorable value perinatal mortality is expected to be reduced with 94.4 %. Depending on the order of analysis, the PAR of maternal risk factors varies from 1.4 to 13.1 %, and for child- and organizational factors 58.7-74.0 and 7.3-34.3 %, respectively. In conclusion, the PAR of maternal-, child- and organizational factors combined is 94.4 %. Optimization of organizational factors may achieve a 34.3 % decrease in perinatal mortality.

  12. Factor analysis of the hospital anxiety and depression scale among a Huntington's disease population

    DEFF Research Database (Denmark)

    Dale, Maria; Maltby, John; Martucci, Rossana

    2015-01-01

    INTRODUCTION: Depression and anxiety are common in Huntington's disease, a genetic neurodegenerative disorder. There is a need for measurement tools of mood to be validated within a Huntington's disease population. The current study aimed to analyze the factor structure of the Hospital Anxiety......, with two group factors, comprising four depression and four anxiety items, provided the best fit of the data. The salience of loadings on the bifactor model suggested that loadings were high on the general factor (accounting for 64% of the variance) and low on the group factors (21% for anxiety and 15......% for depression). CONCLUSIONS: The findings suggest that eight items from the scale perform well among the sample. Consistent with recent developments in modeling the Hospital Anxiety and Depression Scale, a bifactor interpretation for an eight-item version outperformed other extant models. Our findings provide...

  13. Incidence and risk factors for suicide attempts in a general population of young people

    DEFF Research Database (Denmark)

    Christiansen, Erik; Larsen, Kim Juul; Agerbo, Esben;

    2013-01-01

    OBJECTIVE: To estimate the Danish epidemiological long-term incidence rates for suicide attempts in the general population of children and adolescents, and to analyze the impact from single and multiple risk factors on the risk of suicide attempts. METHOD: We used longitudinal register data from...... a total cohort of all individuals born between 1983 and 1989 and living in Denmark to calculate incidence rates. From the cohort, we identified all who have attempted suicide, and matched 50 controls to each case. A nested case-control design was used to estimate the impact from risk factors on the risk...... for index suicide attempts. We established a link to the biological parents and identified risk factors for two generations. Risk factors were analyzed in a conditional logistic regression model. RESULTS: We identified 3718 suicide attempters and 185,900 controls (189,618 individuals, aged 10-21 years). We...

  14. Vascular endothelial growth factor-A is associated with chronic mountain sickness in the Andean population.

    Science.gov (United States)

    Espinoza, Jose R; Alvarez, Giancarlo; León-Velarde, Fabiola; Preciado, Hugo F Ju; Macarlupu, Jose-Luis; Rivera-Ch, Maria; Rodriguez, Jorge; Favier, Judith; Gimenez-Roqueplo, Anne-Paule; Richalet, Jean-Paul

    2014-06-01

    A study of chronic mountain sickness (CMS) with a candidate gene--vascular endothelial growth factor A (VEGFA)--was carried out in a Peruvian population living at high altitude in Cerro de Pasco (4380 m). The study was performed by genotyping of 11 tag SNPs encompassing 2.2 kb of region of VEGFA gene in patients with a diagnosis of CMS (n = 131; 49.1 ± 12.7 years old) and unrelated healthy controls (n = 84; 47.2 ± 13.4 years old). The VEGFA tag SNP rs3025033 was found associated with CMS (p Cerro de Pasco population and HapMap3 population (Fst > 0.36, p < 0.01), suggesting selection is operating on the VEGF gene. Our results suggest that VEGFA is associated with CMS in long-term residents at high altitude in the Peruvian Andes.

  15. Socioeconomic factors affecting marriage, divorce and birth rates in a Japanese population.

    Science.gov (United States)

    Uchida, E; Araki, S; Murata, K

    1993-10-01

    The effects of low income, urbanisation and young age population on age-adjusted rates of first marriage, divorce and live birth among the Japanese population in 46 prefectures were analysed by stepwise regression for 1970 and for 1975. During this period, Japanese society experienced a drastic change from long-lasting economic growth to serious recession in 1973. In both 1970 and 1975, the first marriage rate for females was inversely related to low income and the divorce rates for both males and females were positively related to low income. The live birth rate was significantly related to low income, urbanisation and young age population only in 1975. The first marriage rate for females and the divorce rates for both sexes increased significantly but the first marriage rate for males and live birth rate significantly decreased between 1970 and 1975. These findings suggest that low income was the essential factor affecting first marriage for females and divorce for males and females.

  16. Risk factors for Type II diabetes and diabetic retinopathy in a mexican-american population: Proyecto VER.

    Science.gov (United States)

    West, Sheila K; Munoz, Beatriz; Klein, Ronald; Broman, Aimee T; Sanchez, Rosario; Rodriguez, Jorge; Snyder, Robert

    2002-09-01

    Risk factors for type II diabetes and diabetic retinopathy were determined in a population-based study of Mexican-Americans. Proyecto VER (Vision, Evaluation, and Research) is a cross-sectional study in a random sample of the self-described Hispanic populations in Tucson and Nogales, Arizona, age 40 and older. Of 6,659 eligible subjects, 4,774 (72%) participated in the home questionnaire and clinic visit. Diabetes was defined as self-report of a physician diagnosis or hemoglobin A(1c) value of > or = 7.0%. Only type II diabetes was included. Diabetic retinopathy was assessed on stereo fundus photographs of all persons with diabetes. Questions were asked about demographic, personal, socioeconomic, and diabetes related variables. 1023 (21.4%) of the sample had type II diabetes, and 68% were in the low-income group (annual income less than $20,000). Diabetes was associated with Native-American ancestry, higher acculturation, low income, less education, and increasing body mass index after age and gender adjustment. Persons with previously undiscovered diabetes were more likely to have no regular source of care, no insurance, and currently smoke compared with persons with known diabetes. Only low income was related to proliferative retinopathy, once adjusted for other factors (odds ratio [OR] = 3.93, 95%, confidence limitations [CL] = 1.31-11.80). Several socioeconomic and other factors were associated with diabetes, but few were related to diabetic retinopathy. Persons in the low-income group appeared to be at greater risk of diabetes and the ocular complications of diabetes compared with those with more income. Further longitudinal studies in this population are needed to confirm the associations.

  17. Risk factors for development of critical limb ischemia -- a survey of diabetic vs. nondiabetic population.

    Science.gov (United States)

    Bosevski, M; Meskovska, S; Tosev, S; Peovska, I; Asikov, I; Georgievska-Ismail, L J

    2006-12-01

    The aim of this study is to identify the risk factors for development of chronic critical limb ischemia (CLI) in diabetic and nondiabetic patients with peripheral arterial disease (PAD). 127 patients (pts) with PAD (63 with type 2 diabetes and 64 nondiabetic) were randomly included in a cross sectional study. Out of them 17 were with CLI. Population was investigated for age, height, weight, sex, duration of PAD and diabetes, arterial hypertension, hyperlipidemia, smoking, obesity, systolic blood pressure, value of ankle-brachial index, previous claudicating distance and peripheral intervention, amputation, medical treatment with prostanoids, insulin and antiplatelet drugs and histories of cerebrovascular disease, coronary artery disease and other concomitant diseases. After adjudging linear correlation between mentioned variables and presence of CLI, logistic regression model was built. There were no significant differences in demographic data between both populations. Hyperlipidemia was more frequent in nondiabetic population. Multiple regression model show ankle-brachial index < 0,5, measured in previous 1-3 years (OR 3.39 CI 95% 0.28-40.78), microvascular complication retinopathy (OR 12.98 CI 95% 1.76-95.58), heart failure (OR 1.91 CI 95% 0.29-2.72) and previous prostanoids treatment (OR 15.92 CI 95% 0.53-476.58) as predictors of development of CLI in diabetic population with PAD. After heart failure exclusion of model of nondiabetic pts, previous surgery (OR 3.14 CI 95% 0.61-16.09) and smoking (OR 0.35 CI 95% 0.78-1.62) were presented as prognostic factors for CLI's onset. Our results indicate differences between predictors of CLI's onset in diabetic and nondiabetic population with PAD. Presence of retinopathy, previous measured ankle-brachial index and prostanoids treatment are predictors of development of CLI in diabetic population. Previous surgery is independent predictor for CLI'onset in nondiabetics. Treating concomitant heart failure for both populations

  18. Factors associated with psychological distress or common mental disorders in migrant populations across the world.

    Science.gov (United States)

    Jurado, Dolores; Alarcón, Renato D; Martínez-Ortega, José M; Mendieta-Marichal, Yaiza; Gutiérrez-Rojas, Luis; Gurpegui, Manuel

    We systematically review factors associated with the presence of psychological distress or common mental disorders in migrant populations. Articles published between January 2000 and December 2014 were reviewed and 85 applying multivariate statistical analysis were selected. Common mental disorders were significantly associated with socio-demographic and psychological characteristics, as observed in large epidemiological studies on general populations. The probability of common mental disorders occurrence differs significantly among migrant groups according to their region of origin. Moreover, traumatic events prior to migration, forced, unplanned, poorly planned or illegal migration, low level of acculturation, living alone or separated from family in the host country, lack of social support, perceived discrimination, and the length of migrants' residence in the host country all increase the likelihood of CMD. In contrast, language proficiency, family reunification, and perceived social support reduce such probability. Factors related with the risk of psychiatric morbidity among migrants should be taken into account to design preventive strategies.

  19. Risk Factors for and Barriers to Control Type-2 Diabetes among Saudi Population

    Science.gov (United States)

    Alneami, Yahya Mari; Coleman, Christopher L.

    2016-01-01

    Background: The prevalence of Type-2 Diabetes is dramatically increasing in urban areas within Saudi Arabia. Hence, Type-2 Diabetes has now become the most common public health problem. Understanding the major risk factors for and barriers to control Type-2 Diabetes may lead to strategies to prevent, control, and reduce in the burden of disease cases. Objective: To describe risk factors for and barriers to control Type- 2 Diabetes in Saudi Arabia. Methods: The literature search was conducted on risk factors for and barriers to control Type- 2 Diabetes in Saudi Arabia using the databases PubMed, MEDLINE, and Google Scholar (2007-2015). The literature search yielded 80 articles, of which 70 articles were included in this review after excluding non-relevant articles. Results: The literature review revealed that obesity, physical inactivity, unhealthy diet, smoking, and aging are the major risk factors for Type-2 Diabetes in Saudi Arabia. Further, the review allocated a complex set of barriers including, lack of education, social support, and healthy environment. These barriers may hinder Saudis with Type-2 Diabetes from controlling their disease. Conclusion: The prevalence of Type-2 Diabetes is high among the Saudi population and represents a major public health problem. Effective research programs are needed to address the modifiable risk factors for and barriers to control Type-2 Diabetes among Saudi population. PMID:27157156

  20. Risk factors for coronary atherosclerosis in a general Japanese population: the Hisayama study.

    Science.gov (United States)

    Nakashima, Yutaka; Kiyohara, Yutaka; Doi, Yasufumi; Kubo, Michiaki; Iida, Mitsuo; Sueishi, Katsuo

    2009-01-01

    To investigate risk factors for coronary atherosclerosis in men and women in the recent general Japanese population, we examined coronary arteries obtained from subjects autopsied in the Hisayama cohort study (autopsy rate: 78.7%). The subjects were over 40 years of age and consisted of 125 men and 108 women. They underwent an antemortem medical examination in 1988 and were subject to autopsy at death during an 8-year follow-up period. Atherosclerosis was globally assessed by examining 14 specimens taken from wide areas of epicardial coronary arteries and classified into 6 grades. The frequency of more severe grades of coronary atherosclerosis increased with age in both genders and was greater in men than in women of the same age. Multiple regression analysis revealed that age, systolic blood pressure, serum total cholesterol, and hemoglobin A(1C) were significant risk factors for men. Age, systolic blood pressure, and waist to hip ratio were risk factors for women. Smoking was not significantly correlated with the grade of coronary atherosclerosis in either gender. Thus, aging, hypertension, hypercholesterolemia, obesity, and glucose intolerance are risk factors for coronary atherosclerosis in recent Japanese populations, and the significance of the metabolic risk factors is different between men and women.

  1. Population attributable risks for modifiable lifestyle factors and breast cancer in New Zealand women.

    Science.gov (United States)

    Hayes, J; Richardson, A; Frampton, C

    2013-11-01

    Breast cancer is the most commonly diagnosed invasive cancer in New Zealand women and modifiable lifestyle risk factors may contribute to this. To estimate population attributable risks for modifiable lifestyle factors and breast cancer in New Zealand. Estimates of the magnitude of the impact of modifiable lifestyle risk factors for breast cancer (relative risks and odds ratios obtained from published epidemiological studies) and the prevalence of exposure in New Zealand were used to calculate the population attributable risk percent (PAR%) for each risk factor. The PAR% show the relative importance of these considered risk factors and give an indication of the potential impact of reducing the prevalence of these lifestyle risk factors on the incidence of breast cancer in New Zealand. Six modifiable lifestyle factors were identified for breast cancer. These were obesity, lack of physical activity, high alcohol intake, oral contraceptive use, hormone replacement therapy (HRT) and delayed first birth. The PAR% for these risk factors ranged from 1% for delayed first birth to 10% for obesity (16% for Maori women and 17% for Pacific women). The most important primary preventive strategies to reduce the risk of breast cancer in New Zealand are lifestyle changes to reduce obesity, promoting regular physical activity (which may in turn reduce the prevalence of obesity), reducing HRT use and avoiding high alcohol intake. Strategies that encourage regular physical activity and reduce obesity could also have other benefits, such as reduced risks of cardiovascular disease and diabetes. © 2013 The Authors; Internal Medicine Journal © 2013 Royal Australasian College of Physicians.

  2. PREVALENCE OF RISK FACTORS FOR HEPATITIS C AND ASSOCIATED FACTORS: a population-based study in southern Brazil

    Directory of Open Access Journals (Sweden)

    David Timm KVITKO

    2013-04-01

    Full Text Available Context The hepatitis C is a severe public health problem worldwide because its consequences. Studies which aim at determining the prevalence of risk factors are really important to understand the problem. Objective To estimate the prevalence and factors associated with some risk factors for the disease in a community, called Restinga, located in the city of Porto Alegre, RS, Brazil. Method This paper is based on a population-based cross-sectional study, with systematic sampling and proportional to the size of census tracts in which 3,391 adults answered a standardized questionnaire. Results The prevalence of blood transfusion among the people who were interviewed was 14.98%, 60.83% of those had it before 1993. A total of 16.16% of the people had a tattoo, 7.23% wore a piercing, 1.09% said they had already injected illicit drugs and 12.39% reported previous hospitalization. Prevalence ratios showed that tattoos were more common among young people, piercings among women and illicit drugs among men. Conclusions To summarize, the recognition of risk factors for hepatitis C enables proper screening of possible carriers of the hepatitis C virus, thus enabling a reduction in virus shedding. However, being only possible if health services are prepared to deal with hepatitis C virus, through education and public awareness.

  3. Prevalence of Trypanosoma cruzi and Leishmania chagasi infection and risk factors in a Colombian indigenous population

    OpenAIRE

    Augusto CORREDOR ARJONA; ALVAREZ MORENO Carlos Arturo; Carlos Alberto AGUDELO; BUENO,Martha; López, Myriam Consuelo; CÁCERES,Elvia; REYES Patricia; DUQUE BELTRAN,Sofia; GÜALDRON Luis Eduardo; SANTACRUZ Maria Mercedes

    1999-01-01

    This study was carried out in order to obtain base-line data concerning the epidemiology of American Visceral Leishmaniasis and Chagas? Disease in an indigenous population with whom the government is starting a dwelling improvement programme. Information was collected from 242 dwellings (1,440 people), by means of house to house interviews about socio-economic and environmental factors associated with Leishmania chagasi and Trypanosoma cruzi transmission risk. A leishmanin skin test was appli...

  4. Underlying Factors Associated with Anemia in Amazonian Children: A Population-Based, Cross-Sectional Study

    OpenAIRE

    Cardoso, Marly A.; Scopel,Kézia K.G.; Muniz, Pascoal T.; Eduardo Villamor; Marcelo U. Ferreira

    2012-01-01

    Background: Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey. Methodology: We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelandia, northwest Brazil, to estimate the prevalence of anemia...

  5. Tumor Necrosis Factor and Lymphotoxin-α Polymorphisms and Severe Malaria in African Populations

    OpenAIRE

    Taane G Clark; Diakite, Mahamadou; Auburn, Sarah; Campino, Susana; Fry, Andrew E.; Green, Angela; Richardson, Anna; Small, Kerrin; Teo, Yik Y; Wilson, Jonathan; Jallow, Muminatou; Sisay-Joof, Fatou; Pinder, Margaret; Griffiths, Michael J.; Peshu, Norbert

    2009-01-01

    The tumor necrosis factor gene (TNF) and lymphotoxin-α gene (LTA) have long attracted attention as candidate genes for susceptibility traits for malaria, and several of their polymorphisms have been found to be associated with severe malaria (SM) phenotypes. In a large study involving > 10,000 individuals and encompassing 3 African populations, we found evidence to support the reported associations between the TNF −238 polymorphism and SM in The Gambia. However, no TNF/LTA polymorphisms were ...

  6. Quantitative Population Epigenetics in Screening and Development of Regulator-Active Factors of the Farming System

    OpenAIRE

    Stauss, R.

    2013-01-01

    Likewise, index selection based on statistical genetic theory in plant and animal breeding the methodology "Quantitative Population Epigenetics" can be appropriated to improve efficiency in screening and development of regulator-active factors of the farming system for potential to enhance quantitative characters such as yield, standability and resistance to unfavorable environmental influences (e.g., water stress, cold temperatures, disease resistance). For example, as was shown for an ef...

  7. Population dynamics of dechlorinators and factors affecting the level and products of PCB dechlorination in sediments

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.S.; Sokol, R.C.; Liu, X.; Bethoney, C.M.; Rhee, G.Y. [State Univ. of New York and New York State Department of Health, Albany, NY (United States)

    1996-12-31

    Microbial dechlorination of polychlorinated biphenyls (PCBs) often stops although a significant number of removable chlorines remain. To determine the reason for the cessation, we investigated the limitation of organic carbon, PCB bioavailability, and inhibition by metabolic products. Enrichment with carbon sources did not induce additional chlorination, indicating the plateau was not due to depletion of organic carbon. The bioavailability was not limiting, since a subcritical micelle concentration of the surfactant, which enhanced desorption without inhibiting dechlorinating microorganisms, failed to lower the plateau. Neither was it due to accumulation of metabolites, since no additional dechlorination was detected when plateau sediments were incubated with fresh medium. Similarly, dechlorination was not inhibited in freshly spiked sediment slurries. Dechlorination ended up at the same level with nearly identical congener profiles, regardless of treatment. These results indicate that cessation of dechlorination was due to the accumulation of daughter congeners, which cannot be used as electron acceptors by microbes. To determine whether the decreasing availability affected the microorganisms, we determined the population dynamics of dechlorinators using the most probable number technique. The growth dynamics of the dechlorinators mirrored the time course of dechlorination. It started when the population increased by two orders of magnitude. Once dechlorination stopped the dechlorinating population also began to decrease. When dechlorinators were inoculated into PCB-free sediments, the population decreased over time. The decrease of the population as dechlorination ceased confirms that the diminishing availability of congeners was the reason for the incomplete dechlorination. Recent findings have shown that a second phase of dechlorination of certain congeners can occur after a long lag. 45 refs., 8 figs.

  8. From invasion to latency: intracellular noise and cell motility as key controls of the competition between resource-limited cellular populations

    KAUST Repository

    Guerrero, Pilar

    2015-04-02

    © 2015, Springer-Verlag Berlin Heidelberg. In this paper we analyse stochastic models of the competition between two resource-limited cell populations which differ in their response to nutrient availability: the resident population exhibits a switch-like response behaviour while the invading population exhibits a bistable response. We investigate how noise in the intracellular regulatory pathways and cell motility influence the fate of the incumbent and invading populations. We focus initially on a spatially homogeneous system and study in detail the role of intracellular noise. We show that in such well-mixed systems, two distinct regimes exist: In the low (intracellular) noise limit, the invader has the ability to invade the resident population, whereas in the high noise regime competition between the two populations is found to be neutral and, in accordance with neutral evolution theory, invasion is a random event. Careful examination of the system dynamics leads us to conclude that (i) even if the invader is unable to invade, the distribution of survival times, PS(t), has a fat-tail behaviour (PS(t)∼t-1) which implies that small colonies of mutants can coexist with the resident population for arbitrarily long times, and (ii) the bistable structure of the invading population increases the stability of the latent population, thus increasing their long-term likelihood of survival, by decreasing the intensity of the noise at the population level. We also examine the effects of spatial inhomogeneity. In the low noise limit we find that cell motility is positively correlated with the aggressiveness of the invader as defined by the time the invader takes to invade the resident population: the faster the invasion, the more aggressive the invader.

  9. Factors Associated with Gastrointestinal Parasitic Infections among Young Population in Northeast Brazil

    Directory of Open Access Journals (Sweden)

    Juliana Vasconcelos Lyra da Silva

    2016-01-01

    Full Text Available Background. Intestinal parasitic infections constitute a major public health problem that is frequently associated with poverty, inadequate sanitation, and the nutritional status of the population. Objective. The aim of the present study is to investigate the possible association of parasitic infections, sanitary conditions, hygiene practices, and the nutritional and socioeconomic status of a poor youth population. Methods. A cross-sectional study was conducted with 367 children and adolescents inhabiting a substandard settlement in the urban area of Maceió (Alagoas State, Brazil. Data collection included socioeconomic status, anthropometric measurements, fecal sample examinations, and laboratory blood analysis. The identification of factors associated with gastrointestinal parasitic infections was undertaken through bi- and multivariate analyses. Results. Stool sample analysis obtained from 300 individuals revealed that 204 (68% were infected with at least one parasite species and of these 130 (63.7% were polyparasitized. No significant associations were identified between low height for age (stunted, parasitic infections, and polyparasitism. There was also no association between family income and parasitosis. However, low socioeconomic status proved to be a potential risk factor for parasitic infections. Conclusion. Actions must be taken to improve sanitation, housing, and environmental conditions in order to eliminate the risk factors for parasitic infections, and thereby guarantee a better quality of life for this population.

  10. Factors Associated with Gastrointestinal Parasitic Infections among Young Population in Northeast Brazil

    Science.gov (United States)

    da Silva, Juliana Vasconcelos Lyra; Fontes, Gilberto; dos Santos, Célia Dias; dos Santos, Rafael Vital

    2016-01-01

    Background. Intestinal parasitic infections constitute a major public health problem that is frequently associated with poverty, inadequate sanitation, and the nutritional status of the population. Objective. The aim of the present study is to investigate the possible association of parasitic infections, sanitary conditions, hygiene practices, and the nutritional and socioeconomic status of a poor youth population. Methods. A cross-sectional study was conducted with 367 children and adolescents inhabiting a substandard settlement in the urban area of Maceió (Alagoas State, Brazil). Data collection included socioeconomic status, anthropometric measurements, fecal sample examinations, and laboratory blood analysis. The identification of factors associated with gastrointestinal parasitic infections was undertaken through bi- and multivariate analyses. Results. Stool sample analysis obtained from 300 individuals revealed that 204 (68%) were infected with at least one parasite species and of these 130 (63.7%) were polyparasitized. No significant associations were identified between low height for age (stunted), parasitic infections, and polyparasitism. There was also no association between family income and parasitosis. However, low socioeconomic status proved to be a potential risk factor for parasitic infections. Conclusion. Actions must be taken to improve sanitation, housing, and environmental conditions in order to eliminate the risk factors for parasitic infections, and thereby guarantee a better quality of life for this population. PMID:27528878

  11. Constraints on the bulk Lorentz factor of Gamma-Ray Burst jets from Fermi/LAT upper limits

    CERN Document Server

    Nava, L; Longo, F; Celotti, A; Omodei, N; Vianello, G; Bissaldi, E; Piran, T

    2016-01-01

    It is largely recognized that Gamma-Ray Burst (GRB) jets involve ultra-relativistic motion. However, the value of the Lorentz factor Gamma_0 is still not clear and only lower limits are known for most bursts. We suggest here a new method to obtain upper limits on Gamma_0. The early high-energy synchrotron afterglow flux depends strongly on Gamma_0. Upper limits on GeV emission therefore provide uppers limit on Gamma_0. Applying this method to 190 Fermi GRBs that have not been detected by the Fermi-LAT we place upper limits on the high-energy afterglow flux, and in turn on Gamma_0. For bursts at a typical redshift z=2, we find values of the order of 200 (and above) for a homogeneous density medium, and in the range 100-400 for a wind-like medium. These upper limits are consistent with (and are very close to) lower limits and direct estimates inferred using other methods, suggesting that the typical Lorentz factors of GRB jets are of order a few hundred.

  12. Constraints on the bulk Lorentz factor of gamma-ray burst jets from Fermi /LAT upper limits

    Science.gov (United States)

    Nava, L.; Desiante, R.; Longo, F.; Celotti, A.; Omodei, N.; Vianello, G.; Bissaldi, E.; Piran, T.

    2017-02-01

    It is largely recognized that Gamma-Ray Burst (GRB) jets involve ultra-relativistic motion. However, the value of the Lorentz factor Gamma_0 is still not clear and only lower limits are known for most bursts. We suggest here a new method to obtain upper limits on Gamma_0. The early high-energy synchrotron afterglow flux depends strongly on Gamma_0. Upper limits on GeV emission therefore provide uppers limit on Gamma_0. Applying this method to 190 Fermi GRBs that have not been detected by the Fermi-LAT we place upper limits on the high-energy afterglow flux, and in turn on Gamma_0. For bursts at a typical redshift z=2, we find values of the order of 200 (and above) for a homogeneous density medium, and in the range 100-400 for a wind-like medium. These upper limits are consistent with (and are very close to) lower limits and direct estimates inferred using other methods, suggesting that the typical Lorentz factors of GRB jets are of order a few hundred.

  13. Historical metal pollution in natural gudgeon populations: Inferences from allozyme, microsatellite and condition factor analysis

    Energy Technology Data Exchange (ETDEWEB)

    Knapen, Dries, E-mail: dries.knapen@ua.ac.be [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); De Wolf, Hans [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Knaepkens, Guy [University of Antwerp, Department of Biology, Ethology Research Group, Universiteitsplein 1, 2610 Wilrijk (Belgium); Bervoets, Lieven [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Eens, Marcel [University of Antwerp, Department of Biology, Ethology Research Group, Universiteitsplein 1, 2610 Wilrijk (Belgium); Blust, Ronny [University of Antwerp, Department of Biology, Ecophysiology, Biochemistry and Toxicology Research Group, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Verheyen, Erik [Royal Belgian Institute of Natural Sciences, Department of Vertebrates, Molecular Laboratory, Vautierstraat 29, 1000 Brussel (Belgium)

    2009-10-19

    This study presents the results of a microsatellite and allozyme analysis on natural populations of the gudgeon (Gobio gobio) located in a pollution gradient of cadmium and zinc. Differences among contaminated and reference populations were observed at 2 allozyme loci, as well as a relationship between the fish condition factor and glucose-6-phosphate dehydrogenase genotypes, the locus that showed the largest difference in allele frequencies. The microsatellite data partly confirmed the differentiation pattern that was revealed by the allozyme survey. Our data further suggest that at least 2 microsatellite loci may be affected by natural selection. We thus illustrate that both microsatellite and allozyme loci do not necessarily behave as selectively neutral markers in polluted populations. Estimates of population differentiation can therefore be significantly different depending on which loci are being studied. Finally, these results are discussed in the light of the conservation unit concept, because microsatellites are often used to assess genetic variation in endangered natural populations and to propose measures for conservation or management.

  14. Glucocerebrosidase gene L444P mutation is a risk factor for Parkinson's disease in Chinese population.

    Science.gov (United States)

    Sun, Qi-Ying; Guo, Ji-Feng; Wang, Lei; Yu, Ren-He; Zuo, Xing; Yao, Ling-Yan; Pan, Qian; Xia, Kun; Tang, Bei-Sha

    2010-06-15

    An association between mutations in the glucocerebrosidase (GBA) gene and Parkinson's disease (PD) has been reported in several populations. We searched for four common GBA mutations (L444P, F213I, R353W, and N370S) in 402 Chinese PD patients and 413 age- and sex-matched controls. In the PD cohort, 11 patients were found carrying a heterozygous GBA mutation and all of them had the L444P mutation. Heterozygous GBA mutations were detected none in controls. The GBA gene L444P mutation was detected at a significantly higher frequency among PD patients (11/402 = 2.74%), when compared with the control group (0/413): P = 0.0007. To evaluate the possible role of the GBA gene L444P mutation in PD in Ashkenazi Jewish and non-Jewish populations, we conducted a meta-analysis on the topic. In the Chinese population, the GBA gene L444P mutation was detected at a significantly higher frequency among PD patients, when compared with the control group: Z = 3.83, P = 0.0001, OR = 8.42, confidence interval = 95%, 2.83-25.06. In the non-Jewish populations, the difference was obviously significant: Z = 5.76, P < 0.00001, OR = 8.82, confidence interval = 95%, 4.21-18.48. The results suggest that the GBA gene L444P mutation appears to be a risk factor for PD in Chinese population.

  15. Prevalence of Abnormity of Blood Lipid and Associated Factors in Health Examination Population in Beijing

    Institute of Scientific and Technical Information of China (English)

    Wei-ming Kang; Jie-shi Zhang; Xin-xin Liu; Min-shan Wang; Ming-li Zhao; Jian-chun Yu

    2009-01-01

    Objective To investigate the prevalence of abnormity of blood lipid and associated factors in healthy population in Beijing.Methods Totally,38462 individuals who received health examination were enrolled in our study.We divided them into eight groups according to their ages.The levels of serum total cholesterol,triglyceride,high density lipoprotein cholesterol,and low density lipoprotein cholesterol were tested,and the relationship of blood lipid abnormity with body mass index(BMI)and fasting blood glucose was analyzed.Results The incidences of hypercholesterolemia,hyperglyceridemia,low high-density lipoprotein cholesterolemia,and hyper low-density lipoprotein cholesterolemia presented increasing trend in this population.The incidence rate of abnormity of blood lipid in health examination population increased with BMI increase.The incidence of abnormity of blood lipid in overweight and obesity population was significantly higher than that in low weight and normal weight populations(P<0.05).Meanwhile,the trend of abnormal blood lipid incidence coincided with that of abnormal fasting blood glucose.Conclusions The prevalence of overweight,obesity,and abnormity of blood lipid in Beijing presents increasing trend.The incidence of abnormity of blood lipid increases with BMI increase,in coincidence with that of fasting blood glucose.

  16. Metabolic syndrome in the rural population of Wardha, Central India: An exploratory factor analysis

    Directory of Open Access Journals (Sweden)

    Pradeep R Deshmukh

    2013-01-01

    Full Text Available Background and Objectives: Metabolic syndrome - a plausible precondition for type II diabetes and cardiovascular diseases is also on rise. To understand the mechanistic complexity of metabolic syndrome it is imperative to study the specific contribution of the determinants of metabolic syndrome. Such study can help to identify the most significant factor which may be of use in early detection as well as prevention efforts. Such information is scarcely available from India and especially from rural India. Hence, the present study was undertaken to explore for such factor which might be considered crucial for development of such pathogenesis particularly in rural population of Wardha. Methods: A cross-sectional study comprising of 300 subjects was carried out in rural area of Primary Health Center, attached to medical college with approximate 31,000 populations. The anthropometric parameters such as height, weight, waist circumference were measured. Overnight fasting samples were collected for lipid profile (total cholesterol, triglyceride, high density lipoproteins, low density lipoproteins, very low density lipoproteins and fasting blood glucose levels. The National Cholesterol Education Programme Adult Treatment Panel, ATP-III guidelines were used to categorize the study subjects. As many of the variables are highly intercorrelated, exploratory factor analysis was carried out to reduce the data to a smaller number of independent factors that accounts for the most of the variances in the data. Principal component analysis was used as a method of extraction. Results: For both sexes, three factors were extracted accounting for about 71% variance in the measured variables. An adiposity factor which accounted for highest explained variance (28%, was the initial factor extracted. It was loaded positively by waist circumference, triglyceride, and very low density lipoprotein and negatively loaded by high density lipoprotein. Second factor extracted

  17. Biodemographic and sociocultural factors in two generations of families from six Polish rural and urban populations.

    Science.gov (United States)

    Wolański, N

    1994-01-01

    There were investigated 6967 families from 6 rural regions, under industrialization, and industrialized urban regions. In the grandparents generation there were taken into account 10 traits (an education level, a mating radius, and a stature) and in parents generation 17 traits (the mentioned-above ones and a number of family members, a flat size, incomes, an employees No., a life mode, smoking etc. Numerical characteristics of traits have been calculated jointly and separately in six populations, matrices of correlation have been constructed and moreover factorial analysis have been carried out, as a result of which 8 rotated factors have been obtained. The highest cultural mobility (increase in the level of education) from generation to generation occurs in the population of textile industry town Lódź. The highest improvement of biological status, the increase in mating radius and high incomes are characteristic for this regions, too. On the other side are villages with low culture mobility (not large increase in education level), slight improvement of biological status, almost no migrations, overcrowded flats and low income per family member. The relations between pairs of traits appear to vary largely in several populations. Generally is a high correlation between the education level of the same family members in both generations. The has been stated negative correlation between grandfather stature both of the mother and the father lines, with occurring of positive assortative mating in the couples of two generations. In both investigated generations there is the positive assortative mating, but the negative correlation in the stature between grandfathers of the mother and the father lines. The grandparents education level is correlated with their and their offsprings stature. The duration of holidays is one of the best (closely correlated with others) indicators of life mode, and partially of a given family living conditions, too. 8 hidden factors have been

  18. Population-Level Prediction of Type 2 Diabetes From Claims Data and Analysis of Risk Factors.

    Science.gov (United States)

    Razavian, Narges; Blecker, Saul; Schmidt, Ann Marie; Smith-McLallen, Aaron; Nigam, Somesh; Sontag, David

    2015-12-01

    We present a new approach to population health, in which data-driven predictive models are learned for outcomes such as type 2 diabetes. Our approach enables risk assessment from readily available electronic claims data on large populations, without additional screening cost. Proposed model uncovers early and late-stage risk factors. Using administrative claims, pharmacy records, healthcare utilization, and laboratory results of 4.1 million individuals between 2005 and 2009, an initial set of 42,000 variables were derived that together describe the full health status and history of every individual. Machine learning was then used to methodically enhance predictive variable set and fit models predicting onset of type 2 diabetes in 2009-2011, 2010-2012, and 2011-2013. We compared the enhanced model with a parsimonious model consisting of known diabetes risk factors in a real-world environment, where missing values are common and prevalent. Furthermore, we analyzed novel and known risk factors emerging from the model at different age groups at different stages before the onset. Parsimonious model using 21 classic diabetes risk factors resulted in area under ROC curve (AUC) of 0.75 for diabetes prediction within a 2-year window following the baseline. The enhanced model increased the AUC to 0.80, with about 900 variables selected as predictive (p type 2 diabetes, such as chronic liver disease (odds ratio [OR] 3.71), high alanine aminotransferase (OR 2.26), esophageal reflux (OR 1.85), and history of acute bronchitis (OR 1.45). Liver risk factors emerge later in the process of diabetes development compared with obesity-related factors such as hypertension and high hemoglobin A1c. In conclusion, population-level risk prediction for type 2 diabetes using readily available administrative data is feasible and has better prediction performance than classical diabetes risk prediction algorithms on very large populations with missing data. The new model enables intervention

  19. Factors affecting oral cancer awareness in a high-risk population in India.

    Science.gov (United States)

    Elango, J Kalavathy; Sundaram, Karimassery R; Gangadharan, Paleth; Subhas, Pramod; Peter, Sherry; Pulayath, Civy; Kuriakose, Moni Abraham

    2009-01-01

    To evaluate the awareness of oral cancer, its risk factors and to estimate the prevalence of risk factors in a high-risk semi-urban population in India. A questionnaire-based survey was carried out by house-to-house interview on a single day by 120 health volunteers. The data were analyzed using SPSS 11.0 software for links between prevalence of risk factors and oral cancer awareness, as well as other confounding variables. A total of 1885 persons participated in the survey. Of the surveyed population, 86% had heard about oral cancer and 32% knew someone with oral cancer. Sixty-two percent of the subjects correctly identified the causes; this included 77% of the subjects who identifying smoking, 64% alcohol and 79% pan chewing as a cause of oral cancer. More than 42% believed that poor oral health could lead to oral cancer and 53% thought that oral cancer is an incurable disease. Forty percent of males and 14% females had one or more high-risk habits. It was observed that the awareness was proportional to the education level (p<0.001) and inversely proportional to the prevalence of risk factor habits (p<0.001). Eighty-two percent of the smokers, 75% of the tobacco chewers and 66% of those who consumed alcohol were aware that their habits could lead to oral cancer. Overall, the awareness of oral cancer in this high-risk population was satisfactory, though certain gaps exist, pointing to a need for targeted health education and risk factor cessation counseling.

  20. The Three Domains of Disgust Scale: Factor Structure, Psychometric Properties, and Conceptual Limitations

    Science.gov (United States)

    Olatunji, Bunmi O.; Adams, Thomas; Ciesielski, Bethany; David, Bieke; Sarawgi, Shivali; Broman-Fulks, Joshua

    2012-01-01

    This investigation examined the measurement properties of the Three Domains of Disgust Scale (TDDS). Principal components analysis in Study 1 (n = 206) revealed three factors of Pathogen, Sexual, and Moral Disgust that demonstrated excellent reliability, including test-retest over 12 weeks. Confirmatory factor analyses in Study 2 (n = 406)…

  1. The Three Domains of Disgust Scale: Factor Structure, Psychometric Properties, and Conceptual Limitations

    Science.gov (United States)

    Olatunji, Bunmi O.; Adams, Thomas; Ciesielski, Bethany; David, Bieke; Sarawgi, Shivali; Broman-Fulks, Joshua

    2012-01-01

    This investigation examined the measurement properties of the Three Domains of Disgust Scale (TDDS). Principal components analysis in Study 1 (n = 206) revealed three factors of Pathogen, Sexual, and Moral Disgust that demonstrated excellent reliability, including test-retest over 12 weeks. Confirmatory factor analyses in Study 2 (n = 406)…

  2. Population genetic analysis of the intertidal limpet Lottia scabra and inference of the causes and mechanisms of range limits

    OpenAIRE

    Lehman, Joan

    2010-01-01

    Range limits have been described for many species, and the interest in range limits has increased in the wake of climate change, but few researchers attempt to document the causes and mechanisms of these limits and empirical tests of range limit theory remain sparse. Three principle mechanisms have been proposed to limit species’ range in models incorporating environmental heterogeneity and evolution: genetic impoverishment, migration load, or a physical barrier to dispersal. O...

  3. Plant size and abiotic factors determine the intra-specific variation in the multi-stemmed architecture of Prunus lusitanica in the Northeast limit of its global distribution

    Directory of Open Access Journals (Sweden)

    A. Muñoz Costa

    2013-12-01

    Full Text Available Aim of study: The present work provides novel insights on factors (either intrinsic or extrinsic that trigger sprouting in woody species living at range margins. We aim to explain the inter-individual variability in the multi-stemmed architecture of Prunus lusitanica L., an Iberian evergreen relict tree related to the Tertiary flora.Area of study: Northeastern Mediterranean mountains of the Iberian Peninsula, the Northeast limit of the global distribution of the species.Material and Methods: We gathered data on two modes of vegetative reproduction, basal and layering sprouts, in 288 clumps of Prunus lusitanica from four populations. We modeled and analyzed the effect of environmental factors (topography, canopy cover, soil moisture and disturbances and plant size (diameter at breast height on sprouting by means of Generalized Linear Model and other statistical approaches.Main results: Plant size arises as the principal factor to explain the variability of the numbers of both types of sprouts yet it is not a trigger factor. Natural and anthropogenic disturbances promote basal and layering shoots, while tree canopy is mainly relevant for basal shoots, and slope and soil moisture are significant factors for layering shoots.Research highlights: The multi-stemmed architecture of P. lusitanica at the Northeastern limit of its worldwide distribution is triggered by local environmental factors and disturbances. Each external factor shows different levels of influence on the variability and type of vegetative reproduction yet the intensity of the response is driven by the size of the largest trunk of each clump.Key words: vegetative reproduction; sprouting; disturbances; woody plants; relict tree; subtropical; Iberian Peninsula.

  4. The Lesser Antillean Iguana on St. Eustatius: 2012 status update and review of limiting factors

    NARCIS (Netherlands)

    Debrot, A.O.; Boman, E.

    2013-01-01

    The endangered Lesser Antillean Iguana, Iguana delicatissima, is an emblematic species for the island of St. Eustatius and in Caribbean Netherlands it is only found on St. Eustatius. In this study we conducted an extensive population survey for the iguana and compared densities in different areas to

  5. Spatial correlations of population and ecological factors with distribution of visceral leishmaniasis cases in southwestern Iran

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    Mohammad Amin Ghatee

    2013-08-01

    Full Text Available Background & objectives: Leishmaniasis as a dynamic disease may be markedly influenced by demographic and ecological factors. A geospatial information system study was developed to determine the distribution of visceral leishmaniasis (VL cases in relation to population, climatic and environmental factors in Fars province, southwest of Iran. Methods: The dwelling addresses of 217 VL patients were obtained from hospital files. A hazard map produced by unifying buffers (5 km around nomads travel routes (NTR was developed to survey the effect of close proximity to NTR on the distribution of VL. Mean annual rainfall (MAR, mean annual temperature (MAT, four months temperature mean (T4, elevation, slope and landcover were climatic and environmental factors that have been analysed. Finally, data of dwelling foci were extracted from maps and analysed using logistic regression models. Results: Close proximity to NTR was the most important factor influenced on the disease distribution. Climatic factors were in second rank. Among them, temperature especially T4 is the most effective variable and rainfall was also shown to be another effective climatic agent. Most cases of VL were reported from temperate and semiarid areas in western and central regions while arid condition was a confined factor. The environmental factor of landcovers including urban, dry farm and thin forest regions was revealed as the third rank effective factor. Altitude importance was only shown when its effect was studied independently from other factors. Interpretation & conclusion: These findings present the distribution of VL in Fars province is influenced by combination of ecological and nomads demographical variables although closeness to NTR and nomads role in distribution and continuance of kala-azar are the most important factors.

  6. Dyslipidemia, obesity and other cardiovascular risk factors in the adult population in Senegal.

    Science.gov (United States)

    Doupa, Dominique; Seck, Sidy Mohamed; Dia, Charles Abdou; Diallo, Fatou Agne; Kane, Modou Oumy; Kane, Adama; Gueye, Pape Madieye; Mbaye, Maimouna Ndour; Gueye, Lamine; Jobe, Modou

    2014-01-01

    According to the WHO, 50% of deaths worldwide (40.1% in developing countries) are due to chronic non-communicable diseases (NCDs). Of these chronic NCDs, cardiovascular diseases remain the leading cause of death and disability in developed countries. The Framingham study has shown the importance of hypercholesterolemia as a primary risk factor. In Senegal, the epidemiology of dyslipidemia and obesity are still poorly understood due to the lack of comprehensive studies on their impact on the general population. This motivated this study to look into the key epidemiologic and socio-demographic determinants of these risk factors. It was a cross-sectional descriptive epidemiological survey which included 1037 individuals selected by cluster sampling. Data were collected using a questionnaire following the WHO STEPwise approach. Socio-demographic, health and biomedical variables were collected. P value obese (BMI> 30kg/m2) and 34.8% had abdominal obesity. The main factors significantly associated with dyslipidemia were obesity, urban dwelling, physical inactivity and a family history of dyslipidemia. The prevalence of dyslipidemia, obesity and other risk factors in the population was high needing immediate care for those affected and implementation of prevention strategies.

  7. Association between fifteen risk factors and progressing ischemic stroke in the Han population of northeast China

    Institute of Scientific and Technical Information of China (English)

    YANG Shan-shan; TENG Da; YOU Ding-yun; SU Zhi-qiang; LI Fang; ZHAO Ji-yang

    2010-01-01

    Background The mortality and disability associated with progressing ischemic stroke are much higher than general ischemic stroke. This study was conducted to determine the risk factors for progressing ischemic stroke in the Han population of northeast China.Methods A total of 2511 patients with ischemic stroke within 24 hours admitted to Department of Neurology, First Affiliated Hospital of Harbin Medical University were studied, from November 2007 to May 2009. All of the patients were classified into the progressing or non-progressing group according to the scores of the Scandinavian Neurological Stroke Scale. Fifteen putative risk factors were evaluated. The influence of risk factors for progressing ischemic stroke was analyzed with the simple Logistic analysis, the multiple Logistic analysis, and the stepwise Logistic regression model. All the statistical analysis was performed by SAS 9.1.Results Totally 359 (14.3%) patients met the criteria for progressing ischemic stroke. The Logistic analysis showed that age, family stroke history, smoking history, hypertension on admission, a drop in blood pressure after admission to the hospital, high serum glucose on admission, and fever were related to progressing ischemic stroke in the Han population of northeast China.Conclusion People of the ischemic stroke with these factors are more likely to develop progressing ischemic stroke.

  8. Personality factors and suicide risk in a representative sample of the German general population.

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    Victor Blüml

    Full Text Available OBJECTIVE: Previous research has shown an association between certain personality characteristics and suicidality. Methodological differences including small sample sizes and missing adjustment for possible confounding factors could explain the varying results. The aim of this study was to assess the impact of the Big Five personality dimensions on suicidality in a representative population based sample of adults. METHOD: Interviews were conducted in a representative German population-based sample (n=2555 in 2011. Personality characteristics were assessed using the Big Five Inventory-10 (BFI-10 and suicide risk was assessed with the Suicidal Behaviors Questionnaire-Revised (SBQ-R. Multivariate logistic regression models were calculated adjusting for depression, anxiety, and various sociodemographic variables. RESULTS: Neuroticism and openness were significantly associated with suicide risk, while extraversion and conscientiousness were found to be protective. Significant sex differences were observed. For males, extraversion and conscientiousness were protective factors. Neuroticism and openness were found to be associated with suicide risk only in females. These associations remained significant after adjusting for covariates. CONCLUSION: The results highlight the role of personality dimensions as risk factors for suicide-related behaviors. Different personality dimensions are significantly associated with suicide-related behaviors even when adjusting for other known risk factors of suicidality.

  9. [Limiting a Medline/PubMed query to the "best" articles using the JCR relative impact factor].

    Science.gov (United States)

    Avillach, P; Kerdelhué, G; Devos, P; Maisonneuve, H; Darmoni, S J

    2014-12-01

    Medline/PubMed is the most frequently used medical bibliographic research database. The aim of this study was to propose a new generic method to limit any Medline/PubMed query based on the relative impact factor and the A & B categories of the SIGAPS score. The entire PubMed corpus was used for the feasibility study, then ten frequent diseases in terms of PubMed indexing and the citations of four Nobel prize winners. The relative impact factor (RIF) was calculated by medical specialty defined in Journal Citation Reports. The two queries, which included all the journals in category A (or A OR B), were added to any Medline/PubMed query as a central point of the feasibility study. Limitation using the SIGAPS category A was larger than the when using the Core Clinical Journals (CCJ): 15.65% of PubMed corpus vs 8.64% for CCJ. The response time of this limit applied to the entire PubMed corpus was less than two seconds. For five diseases out of ten, limiting the citations with the RIF was more effective than with the CCJ. For the four Nobel prize winners, limiting the citations with the RIF was more effective than the CCJ. The feasibility study to apply a new filter based on the relative impact factor on any Medline/PubMed query was positive. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  10. Factors that Limit and Enable Preschool-Aged Children's Physical Activity on Child Care Centre Playgrounds

    Science.gov (United States)

    Coleman, Bianca; Dyment, Janet E.

    2013-01-01

    The incidence of childhood obesity amongst preschool-aged children has increased dramatically in recent years and can be attributed, in part, to a lack of physical activity amongst children in this age group. This study explores the social factors that stand to limit and/or enable children's physical activity opportunities in outdoor settings…

  11. 23 CFR 636.302 - Are there any limitations on the selection and use of proposal evaluation factors?

    Science.gov (United States)

    2010-04-01

    ... TRANSPORTATION ENGINEERING AND TRAFFIC OPERATIONS DESIGN-BUILD CONTRACTING Proposal Evaluation Factors § 636.302... contracting agency wishes to use Federal-aid highway funds for final design and construction, the subsequent... 23 Highways 1 2010-04-01 2010-04-01 false Are there any limitations on the selection and use...

  12. Thermal variation and factors influencing vertical migration behavior in Daphnia populations.

    Science.gov (United States)

    Glaholt, Stephen P; Kennedy, Meghan L; Turner, Elizabeth; Colbourne, John K; Shaw, Joseph R

    2016-08-01

    The antipredator behavior diel vertical migration (DVM), common in aquatic keystone species Daphnia, involves daily migration from warmer surface waters before dawn to cooler deeper waters after dusk. Plasticity in Daphnia DVM behavior optimizes fitness via trade-offs between growth, reproduction, and predator avoidance. Migration behavior is affected by co-varying biotic and abiotic factors, including light, predator cues, and anthropogenic stressors making it difficult to determine each factor's individual contribution to the variation in this behavior. This study aims to better understand this ecologically significant behavior in Daphnia by: (1) determining how Daphnia pulicaria thermal preferences vary within and among natural populations; (2) distinguishing the role of temperature verses depth in Daphnia vertical migration; and (3) defining how two anthropogenic stressors (copper and nickel) impact Daphnia migratory behavior. Simulated natural lake stratification were constructed in 8L (0.5m tall, 14.5cm wide) water columns to monitor under controlled laboratory conditions the individual effects of temperature gradients, depth, and metal stressors on Daphnia vertical migration. Three major findings are reported. First, while no difference in thermal preference was found among the four populations studied, within lake populations variability among isolates was high. Second, decoupling temperature and depth revealed that depth was a better predictor of Daphnia migratory patterns over temperature. Third, exposure to environmentally relevant concentrations of copper or nickel inhibited classic DVM behavior. These findings revealed the high variability in thermal preference found within Daphnia populations, elucidated the individual roles that depth and temperature have on migratory behavior, and showed how copper and nickel can interfere with the natural response of Daphnia to fish predator cues. Thus contributing to the body of knowledge necessary to predict how

  13. Population attributable risk of breast cancer in white women associated with immediately modifiable risk factors

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    Glaser Sally L

    2006-06-01

    Full Text Available Abstract Background Estrogen/progestin replacement therapy (EPRT, alcohol consumption, physical activity, and breast-feeding duration differ from other factors associated with breast cancer in being immediately modifiable by the individual, thereby representing attractive targets for future breast cancer prevention efforts. To justify such efforts, it is vital to quantify the potential population-level impacts on breast cancer considering population variations in behavior prevalence, risk estimate, and baseline incidence. Methods For each of these four factors, we calculated population attributable risk percents (PARs using population-based survey (2001 and cancer registry data (1998–2002 for 41 subpopulations of white, non-Hispanic California women aged 40–79 years, and ranges of relative risk (RR estimates from the literature. Results Using a single RR estimate, subpopulation PARs ranged from 2.5% to 5.6% for hormone use, from 0.0% to 6.1% for recent consumption of >= 2 alcoholic drinks daily, and 4.6% to 11.0% for physical inactivity. Using a range of RR estimates, PARs were 2–11% for EPRT use, 1–20% for alcohol consumption and 2–15% for physical inactivity. Subpopulation data were unavailable for breastfeeding, but PARs using published RR estimates ranged from 2% to 11% for lifetime breastfeeding >= 31 months. Thus, of 13,019 breast cancers diagnosed annually in California, as many as 1,432 attributable to EPRT use, 2,604 attributable to alcohol consumption, 1,953 attributable to physical inactivity, and 1,432 attributable to never breastfeeding might be avoidable. Conclusion The relatively feasible lifestyle changes of discontinuing EPRT use, reducing alcohol consumption, increasing physical activity, and lengthening breastfeeding duration could lower population breast cancer incidence substantially.

  14. Physical limitations and fundamental factors affecting performance of liquid crystal tunable lenses with concentric electrode rings.

    Science.gov (United States)

    Li, Liwei; Bryant, Doug; van Heugten, Tony; Bos, Philip J

    2013-03-20

    A comprehensive analysis of fundamental factors and their effects on the performance of liquid crystal (LC)-based lenses is given. The analysis adopts numerical LC director and electric field simulation, as well as scalar diffraction theory for calculating the lens performance considering different variable factors. A high-efficiency LC lens with concentric electrode rings is fabricated for verifying and enriching the analysis. The measurement results are in close agreement with the analysis, and a summary of key factors is given with their quantitative contributions to the efficiency.

  15. Prevalence and risk factors for developing posttraumatic stress disorder in a general intensive care population - a literature review

    OpenAIRE

    Nilsen, Cecilie Bræin

    2016-01-01

    Aim: 1) To investigate prevalence of posttraumatic stress disorder (PTSD) and symptoms of posttraumatic stress (PTSS) in a general intensive care patient population, and risk factors for post ICU-PTSD/PTSS. 2) To investigate how instruments and loss to follow-up could influence the prevalence of PTSD/PTSS in this patient population. Background: Studies have found a wide variance of PTSD/PTSS in this patient population. A number of risk factors were associated with developing post-ICU ...

  16. Classification of chronic rhinosinusitis according to a nasal polyp and tissue eosinophilia: limitation of current classification system for Asian population

    Science.gov (United States)

    Cho, Sung-Woo; Kim, Dae Woo; Kim, Jeong-Whun; Lee, Chul Hee

    2017-01-01

    Chronic rhinosinusitis (CRS) can be classified according to the presence of a nasal polyp (NP): CRS with NP (CRSwNP) and CRS without NP (CRSsNP). CRSwNP has characteristics with high infiltration of tissue eosinophilia with a burst of Th2 inflammatory cytokine. However recent findings in Eastern Asia countries suggest that CRSwNP can be divided according to the presence of tissue eosinophilia. Thus, CRSwNP can be classified into eosinophilic and noneosinophilic. Eosinophilic CRSwNP seems to have different immunological and clinical feature compared to noneosinophilic CRSwNP. From the same point of view, CRSsNP can also be divided according to tissue eosinophilia. However, the meaning of this dichotomous categorization in CRS seems to be not quite clear. This review focus on the limitations in current subclassification of CRS according to the presence of NP and tissue eosinophilia and discuss other factors related to tissue remodeling and NP generation which may provide clues for the further understanding of CRS pathogenesis. PMID:28765816

  17. Attaining higher resolution visual prosthetics: a review of the factors and limitations

    Science.gov (United States)

    Eiber, Calvin D.; Lovell, Nigel H.; Suaning, Gregg J.

    2013-02-01

    Visual prosthetics is an expanding subfield of functional electrical stimulation which has gained increased interest recently in light of new advances in treatments and technology. These treatments and technology represent a major improvement over prior art, but are still subject to a host of limitations which are dependent on the manner in which one approaches the topic of visual prosthetics. These limitations pose new research challenges whose solutions are directly applicable to the well-being of blind individuals everywhere. In this review, we will outline and critically compare major current approaches to visual prosthetics, and in particular retinal prosthetics. Then, we will engage in an in-depth discussion of the limitations imposed by current technology, physics, and the underlying biology of the retina to highlight several of the challenges currently facing researchers. .

  18. Alcohol consumption, physical activity, and chronic disease risk factors: a population-based cross-sectional survey

    Directory of Open Access Journals (Sweden)

    Djoussé Luc

    2006-05-01

    Full Text Available Abstract Background Whether the association of alcohol consumption and cardiovascular disease is the product of confounding and the degree to which this concern applies to other behaviors are unclear. Methods Using the 2003 Behavioral Risk Factor Surveillance System, a population-based telephone survey of adults in the US, we compared chronic disease risk factors between 123,359 abstainers and 126,674 moderate drinkers, defined as intake of ≤ 2 drinks per day among men and ≤ 1 drink per day among women, using age- and sex- and multivariable-adjusted models. We also compared sedentary and active individuals, defined as moderate physical activity ≥ 30 minutes per day for ≥ 5 days per week, or vigorous activity for ≥ 20 minutes per day on ≥ 3 days. Results Chronic disease risk factors and features of unhealthy lifestyle were generally more prevalent among abstainers than drinkers in age- and sex-adjusted analyses, but these differences were generally attenuated or eliminated by additional adjustment for race and education. For low fruit and vegetable intake, divorced marital status, and absence of a personal physician, adjustment for race and education reversed initially positive age- and sex-adjusted associations with abstention. Comparison of sedentary and active individuals produced similar findings, with generally lower levels of risk factors among more physical active individuals. Conclusion The differences between abstainers and drinkers are attenuated after adjustment for limited sociodemographic features, and sedentary and active individuals share a similar pattern. Although observational studies of both factors may be susceptible to uncontrolled confounding, our results provide no evidence that moderate drinking is unique in this regard. Ultimately, randomized trials of all such lifestyle factors will be needed to answer these questions definitively.

  19. Socioeconomic inequalities in the prevalence of nine established cardiovascular risk factors in a southern European population.

    Directory of Open Access Journals (Sweden)

    Luís Alves

    Full Text Available The evaluation of the gender-specific prevalence of cardiovascular risk factors across socioeconomic position (SEP categories may unravel mechanisms involved in the development of coronary heart disease. Using a sample of 1704 community dwellers of a Portuguese urban center aged 40 years or older, assessed in 1999-2003, we quantified the age-standardized prevalence of nine established cardiovascular risk factors (diabetes mellitus, hypertension, hypercholesterolemia, smoking, sedentariness, abdominal obesity, poor diet, excessive alcohol intake and depression across SEP and gender categories. Data on individual education and occupation were collected by questionnaire and used to characterize SEP. The prevalence of seven out of nine well-established risk factors was higher in men. Among women, the prevalence of most of the studied risk factors was higher in lower SEP groups. The main exception was smoking, which increased with education and occupation levels. Among men, socioeconomic gradients were less clear, but lower SEP was associated with a higher prevalence of diabetes, excessive alcohol intake and depression in a graded mode. The historical cultural beliefs and practices captured throughout the lifecourse frame the wide socioeconomic gradients discernible in our study conducted in an unequal European developed population. While men were more exposed to most risk factors, the clearer associations between SEP and risk factors among women support that their adoption of particular healthy behaviors is more dependent on material and symbolic conditions. To fully address the issue of health inequalities, interventions within the health systems should be complemented with population-based policies specifically designed to reduce socioeconomic gradients.

  20. Multiple Risk Factor Clustering and Risk of Hypertension in the Mongolian Ethnic Population of China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To evaluate whether the clustering of risk factors, both environmental and genetic, increases the risk of essential hypertension (EH) and the accumulation of risk factors influences the blood pressure level in normotensives. Methods On the basis of a prevalence survey, 501 subjects of Mongolian ethnicity (243hypertensives and 258 normotensives) who were not related to each other were selected to conduct a case-control study.All subjects were interviewed with questionnaires and their blood specimens were collected. Renin gene insertion/deletion (I/D) polymorphism, a new genetic marker, was genotyped with PCR and polyacrylamide gel electrophoresis. Results Overweight, alcohol consumption, and renin gene I/D polymorphism were significant risk factors of EH (P<0.05). The odds ratios (OR) for the number of risk factors were 2.39 (95%CI: 0.98-6.74) for one risk factor, 5.03 (95%CI: 2.06-14.18) for two, and 6.09 (95%CI: 1.85-22.38) for three respectively after adjusting for age and sex. In normotensives, age- and sex-adjusted mean blood pressures increased with more accumulation of risk factors.However, there were no significant differences among the different blood pressure levels according to the number of risk factors (P>0.05). Conclusion Overweight, alcohol consumption, and renin gene I/D polymorphism are risk factors of EH in the Mongolian ethnic population of China. The accumulation of the risk factors causes a sharp increase of the risk of EH.

  1. Factor structure of the 12-item General Health Questionnaire in the Japanese general adult population.

    Science.gov (United States)

    Doi, Yuriko; Minowa, Masumi

    2003-08-01

    The 12-item General Health Questionnaire (GHQ-12) has been extensively used in a variety of settings across countries. The main aim of the present study was to assess the factor structure of the GHQ-12 for the Japanese general adult population. Data came from a sample of 1808 Japanese aged 20 years or older who were randomly selected based on the 1995 census (897 men and 911 women). Cronbach's alpha coefficients were 0.83 for men and 0.85 for women. Overall, the corrected item-total correlation coefficients were >0.20 for both genders. The GHQ-12 yielded a two-factor solution of psychological distress (items 2, 5, 6, 9, 10 and 11) and social dysfunction (items 1, 3, 4, 7 and 8), which jointly accounted for 49.1% of the total variance, for women. Item 12 on happiness was not discernable. For men, item 12 was separated from a social dysfunction factor and yielded the third factor with item 3 on social role, and the three factors jointly accounted for 57.6%. The results of the present study suggest that the GHQ-12 can be used as an internally reliable and homogeneous scale that produces mainly the factors of psychological distress and social dysfunction. Item 12 may be structurally different in the case of Japanese adults.

  2. Sex-specific genetic diversity is shaped by cultural factors in Inner Asian human populations.

    Science.gov (United States)

    Marchi, Nina; Hegay, Tatyana; Mennecier, Philippe; Georges, Myriam; Laurent, Romain; Whitten, Mark; Endicott, Philipp; Aldashev, Almaz; Dorzhu, Choduraa; Nasyrova, Firuza; Chichlo, Boris; Ségurel, Laure; Heyer, Evelyne

    2017-04-01

    Sex-specific genetic structures have been previously documented worldwide in humans, even though causal factors have not always clearly been identified. In this study, we investigated the impact of ethnicity, geography and social organization on the sex-specific genetic structure in Inner Asia. Furthermore, we explored the process of ethnogenesis in multiple ethnic groups. We sampled DNA in Central and Northern Asia from 39 populations of Indo-Iranian and Turkic-Mongolic native speakers. We focused on genetic data of the Y chromosome and mitochondrial DNA. First, we compared the frequencies of haplogroups to South European and East Asian populations. Then, we investigated the genetic differentiation for eight Y-STRs and the HVS1 region, and tested for the effect of geography and ethnicity on such patterns. Finally, we reconstructed the male demographic history, inferred split times and effective population sizes of different ethnic groups. Based on the haplogroup data, we observed that the Indo-Iranian- and Turkic-Mongolic-speaking populations have distinct genetic backgrounds. However, each population showed consistent mtDNA and Y chromosome haplogroups patterns. As expected in patrilocal populations, we found that the Y-STRs were more structured than the HVS1. While ethnicity strongly influenced the genetic diversity on the Y chromosome, geography better explained that of the mtDNA. Furthermore, when looking at various ethnic groups, we systematically found a genetic split time older than historical records, suggesting a cultural rather than biological process of ethnogenesis. This study highlights that, in Inner Asia, specific cultural behaviors, especially patrilineality and patrilocality, leave a detectable signature on the sex-specific genetic structure. © 2017 Wiley Periodicals, Inc.

  3. Psychosocial biomarker research: integrating social, emotional and economic factors into population studies of aging and health.

    Science.gov (United States)

    Steptoe, Andrew

    2011-04-01

    There are complex reciprocal relationships between health and social, emotional and economic factors in aging populations. Social and affective neurosciences are rapidly developing an understanding of the mechanisms underlying these phenomena using sophisticated behavioural, neuroimaging and psychophysiological methods. These techniques are often complex and expensive, so are generally used in relatively small selected samples rather than in large-scale cohort studies. However, an understanding of the significance of these processes in health and well-being depends on integrating findings from social and affective neuroscience into population-level studies. The aim of this article is to describe how a population perspective on the determinants of health and well-being in old age articulates with the agenda of social, affective and economic neuroscience, particularly through the application of psychosocial biomarker research. Social and affective neuroscience and epidemiological approaches provide complementary research strategies for understanding the mechanisms linking social, emotional and economic factors with health risk. This will be illustrated primarily from findings from two studies conducted at University College London, the Whitehall II Study and the English Longitudinal Study of Ageing.

  4. Clinical and demographic factors and outcome of amyotrophic lateral sclerosis in relation to population ancestral origin.

    Science.gov (United States)

    Marin, Benoît; Logroscino, Giancarlo; Boumédiene, Farid; Labrunie, Anaïs; Couratier, Philippe; Babron, Marie-Claude; Leutenegger, Anne Louise; Preux, Pierre Marie; Beghi, Ettore

    2016-03-01

    To review how the phenotype and outcome of amyotrophic lateral sclerosis (ALS) change with variations in population ancestral origin (PAO). Knowledge of how PAO modifies ALS phenotype may provide important insight into the risk factors and pathogenic mechanisms of the disease. We performed a systematic review and meta-analysis of the literature concerning differences in phenotype and outcome of ALS that relate to PAO. A review of 3111 records identified 78 population-based studies. The 40 that were included covered 40 geographical areas in 10 subcontinents. Around 12,700 ALS cases were considered. The results highlight the phenotypic heterogeneity of ALS at time of onset [age, sex ratio (SR), bulbar onset], age at diagnosis, occurrence of comorbidities in the first year after diagnosis, and outcome (survival). Subcontinent is a major explanatory factor for the variability of the ALS phenotype in population-based studies. Some markers of ALS phenotype were homogeneously distributed in western countries (SR, mean age at onset/diagnosis) but their distributions in other subcontinents were remarkably different. Other markers presented variations in European subcontinents (familial ALS, bulbar onset) and in other continents. As a consequence, ALS outcome strongly varied, with a median survival time from onset ranging from 24 months (Northern Europe) to 48 months (Central Asia). This review sets the scene for a collaborative study involving a wide international consortium to investigate, using a standard methodology, the link between ancestry, environment, and ALS phenotype.

  5. Setting an indoor air exposure limit for formaldehyde: Factors of concern

    NARCIS (Netherlands)

    Arts, J.H.E.; Muijser, H.; Kuper, C.F.; Woutersen, R.A.

    2008-01-01

    The paper aims to evaluate the indoor air limit of 1 μg/m3 (0.8 ppb) formaldehyde as advised by the European Commission [the INDEX project; Kotzias, D., Koistinen, K., Kephalopoulos, S., Schlitt, C., Carrer, P., Maroni, M., Jantunen, M., Cochet, C., Kirchner, S., Lindvall, T., McLaughlin, J.,

  6. Setting an indoor air exposure limit for formaldehyde: Factors of concern

    NARCIS (Netherlands)

    Arts, J.H.E.; Muijser, H.; Kuper, C.F.; Woutersen, R.A.

    2008-01-01

    The paper aims to evaluate the indoor air limit of 1 μg/m3 (0.8 ppb) formaldehyde as advised by the European Commission [the INDEX project; Kotzias, D., Koistinen, K., Kephalopoulos, S., Schlitt, C., Carrer, P., Maroni, M., Jantunen, M., Cochet, C., Kirchner, S., Lindvall, T., McLaughlin, J., Mølhav

  7. Soil physical constraints as a limiting factor of palm and tree basal area in amazonian forests

    NARCIS (Netherlands)

    Emilio, T.; Quesada, C.A.; Costa, F.; Monteagudo, A.; Araujo, A.; Pena-Cruz, A.; Torres Lezama, A.; Castilho, C.V.; Neill, D.; Vilanova, E.; Oblitas Mendoza, E.M.; Alvarez, E.; Honorio, E.N.; Parada, G.A.; ter Steege, H.; Ramirez-Angulo, H.; Chave, J.; Terborgh, J.W.; Schietti, J.; Silveira, M.; Penuela-Mora, M.C.; Schwarz, M.; Banki, O.; Philips, O.L.; Thomas, R.; Vasquez, R.; Brienen, R.J.W.; Feldpausch, T.R.; Killeen, T.J.; Baker, T.R.; Magnusson, W.E.; Mahli, Y.

    2014-01-01

    Background: Trees and arborescent palms adopt different rooting strategies and responses to physical limitations imposed by soil structure, depth and anoxia. However, the implications of these differences for understanding variation in the relative abundance of these groups have not been explored.

  8. Physics of Limiting Phenomena in Superconducting Microwave Resonators: Vortex Dissipation, Ultimate Quench and Quality Factor Degradation Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Checchin, Mattia [IIT, Chicago

    2016-01-01

    Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the

  9. Physics of Limiting Phenomena in Superconducting Microwave Resonators: Vortex Dissipation, Ultimate Quench and Quality Factor Degradation Mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Checchin, Mattia [Illinois Inst. of Technology, Chicago, IL (United States)

    2016-12-01

    Superconducting niobium accelerating cavities are devices operating in radio-frequency and able to accelerate charged particles up to energy of tera-electron-volts. Such accelerating structures are though limited in terms of quality factor and accelerating gradient, that translates--in some cases--in higher capital costs of construction and operation of superconducting rf accelerators. Looking forward for a new generation of more affordable accelerators, the physical description of limiting mechanisms in superconducting microwave resonators is discussed. In particular, the physics behind the dissipation introduced by vortices in the superconductor, the ultimate quench limitations and the quality factor degradation mechanism after a quench are described in detail. One of the limiting factor of the quality factor is the dissipation introduced by trapped magnetic flux vortices. The radio-frequency complex response of trapped vortices in superconductors is derived by solving the motion equation for a magnetic flux line, assuming a bi-dimensional and mean free path-dependent Lorentzian-shaped pinning potential. The resulting surface resistance shows the bell-shaped trend as a function of the mean free path, in agreement with the experimental data observed. Such bell-shaped trend of the surface resistance is described in terms of the interplay of the two limiting regimes identified as pinning and flux flow regimes, for low and large mean free path values respectively. The model predicts that the dissipation regime--pinning- or flux-flow-dominated--can be tuned either by acting on the frequency or on the electron mean free path value. The effect of different configurations of pinning sites and strength on the vortex surface resistance are also discussed. Accelerating cavities are also limited by the quench of the superconductive state, which limits the maximum accelerating gradient achievable. The accelerating field limiting factor is usually associate d to the

  10. Unique Features of High-Density Lipoproteins in the Japanese: In Population and in Genetic Factors

    Directory of Open Access Journals (Sweden)

    Shinji Yokoyama

    2015-04-01

    Full Text Available Despite its gradual increase in the past several decades, the prevalence of atherosclerotic vascular disease is low in Japan. This is largely attributed to difference in lifestyle, especially food and dietary habits, and it may be reflected in certain clinical parameters. Plasma high-density lipoprotein (HDL levels, a strong counter risk for atherosclerosis, are indeed high among the Japanese. Accordingly, lower HDL seems to contribute more to the development of coronary heart disease (CHD than an increase in non-HDL lipoproteins at a population level in Japan. Interestingly, average HDL levels in Japan have increased further in the past two decades, and are markedly higher than in Western populations. The reasons and consequences for public health of this increase are still unknown. Simulation for the efficacy of raising HDL cholesterol predicts a decrease in CHD of 70% in Japan, greater than the extent by reducing low-density lipoprotein cholesterol predicted by simulation or achieved in a statin trial. On the other hand, a substantial portion of hyperalphalipoproteinemic population in Japan is accounted for by genetic deficiency of cholesteryl ester transfer protein (CETP, which is also commonly unique in East Asian populations. It is still controversial whether CETP mutations are antiatherogenic. Hepatic Schistosomiasis is proposed as a potential screening factor for historic accumulation of CETP deficiency in East Asia.

  11. Risk factors for injuries in landslide- and flood-affected populations in Uganda.

    Science.gov (United States)

    Agrawal, Shreya; Gopalakrishnan, Tisha; Gorokhovich, Yuri; Doocy, Shannon

    2013-08-01

    The frequency of occurrence of natural disasters has increased over the past several decades, which necessitates a better understanding of human vulnerability, particularly in low-resource settings. This paper assesses risk factors for injury in the March 2010 floods and landslides in Eastern Uganda, and compares the effects of location, injury type, and severity. A stratified cluster survey of the disaster-affected populations was conducted five months after onset of the disasters. Probability proportional to size sampling was used to sample 800 households, including 400 affected by floods in Butaleja District and 400 affected by landslides in Bududa District. Flood- and landslide-affected populations were surveyed in July 2010 using a stratified cluster design. The odds of injury were 65% higher in the flood-affected groups than the landslide-affected groups in a logistic regression (OR = 0.35; 95% CI, 0.24-0.52; P landslide-affected population, and injuries were more severe. This study illustrates differences between populations injured by flood and landslide disasters that occurred simultaneously in Eastern Uganda in 2010. In areas where landslides are prone to occur due to massive rainfalls or floods, preventative measures, such as early warning systems and evacuation, are more likely to increase the likelihood of people surviving, while for areas with massive floods, immediate and effective medical attention can save lives and improve injury outcomes.

  12. Lifestyle factors and experience of respiratory alarm symptoms in the general population

    DEFF Research Database (Denmark)

    Sele, Lisa Maria Falk; Balasubramaniam, Kirubakaran; Elnegaard, Sandra

    2015-01-01

    BACKGROUND: The first step in the diagnosis of lung cancer is for individuals in the general population to recognise respiratory alarm symptoms (RAS). Knowledge is sparse about RAS and factors associated with experiencing RAS in the general population. This study aimed to estimate the prevalence......: ORmen=1.42, 95% CI 1.39 to 1.56; ORwomen=1.25, 95% CI 1.15 to 1.36; current smoking: ORmen=2.58, 95% CI 2.35 to 2.83; ORwomen=2.45, 95% CI 2.25 to 2.68). Individuals who were underweight or obese were significantly more likely to report at least one RAS. Odds of reporting at least one RAS increased...... with increasing alcohol intake for both genders (Ptrendobese are positively associated with experiencing RAS...

  13. Risk factors for bacterial vaginosis in pregnancy: a population-based study on Danish women

    DEFF Research Database (Denmark)

    Thorsen, Poul; Vogel, Ida; Molsted, Kirsten

    2006-01-01

    Background. No larger population-based study of bacterial vaginosis in pregnancy has previously been available. The objective of this study was to examine risk factors for bacterial vaginosis in pregnancy. Design. From a prospective population-based cohort of 3,596 eligible pregnant women, 2......,927 (81.4%) completed the study. Methods. Women were asked to participate in this study at their first prenatal visit at 17 gestational weeks (range 7+/324+/0). Samples from the genital tract were taken at enrolment. Bacterial vaginosis was determined by Amsel's clinical criteria (3 out of 4: pH>/4.......5, homogenous discharge, clue cells, and positive amine test). Data were collected from three questionnaires completed during the second and third trimesters and correlated with the diagnosis of bacterial vaginosis. Crude and adjusted relative risks (reproductive, medical, behavioral, sexual...

  14. Tumor Necrosis Factor and Lymphotoxin-α Polymorphisms and Severe Malaria in African Populations

    Science.gov (United States)

    Clark, Taane G.; Diakite, Mahamadou; Auburn, Sarah; Campino, Susana; Fry, Andrew E.; Green, Angela; Richardson, Anna; Small, Kerrin; Teo, Yik Y.; Wilson, Jonathan; Jallow, Muminatou; Sisay-Joof, Fatou; Pinder, Margaret; Griffiths, Michael J.; Peshu, Norbert; Williams, Thomas N.; Marsh, Kevin; Molyneux, Malcolm E.; Taylor, Terrie E.; Rockett, Kirk A.; Kwiatkowski, Dominic P.

    2009-01-01

    The tumor necrosis factor gene (TNF) and lymphotoxin-α gene (LTA) have long attracted attention as candidate genes for susceptibility traits for malaria, and several of their polymorphisms have been found to be associated with severe malaria (SM) phenotypes. In a large study involving > 10,000 individuals and encompassing 3 African populations, we found evidence to support the reported associations between the TNF −238 polymorphism and SM in The Gambia. However, no TNF/LTA polymorphisms were found to be associated with SM in cohorts in Kenya and Malawi. It has been suggested that the causal polymorphisms regulating the TNF and LTA responses may be located some distance from the genes. Therefore, more-detailed mapping of variants across TNF/LTA genes and their flanking regions in the Gambian and allied populations may need to be undertaken to find any causal polymorphisms. PMID:19281305

  15. Prevalence of Coronary Risk Factors among Population Aged 35 Years and Above From Rural Maharashtra, India

    Directory of Open Access Journals (Sweden)

    Abhishek Singh

    2014-01-01

    Full Text Available Background: It is predicted that cardiovascular diseases will be the most important cause of mortality in India by the year 2015. Since the key to combating the increased incidence of coronary artery disease (CAD is the control of known risk factors by a population based strategy aimed at comprehensive risk reduction, it is pertinent to study the magnitude of the risk. Aim: The present study was therefore conducted to assess the prevalence of certain coronary risk factors among rural population aged 35 years and above in Maharashtra. Methods: The present community based cross sectional survey was carried out in the rural area of Pune district on 272 subjects using a structured questionnaire, clinical examination followed by lab investigations. SPSS version 17.0 was used for analysis. Results: Tobacco consumption was found to be prevalent in 51.83% of the study subjects followed by physical inactivity which was prevalent among 31.61% whereas high diastolic blood pressure was found to be prevalent in 29.41% of the study subjects. Obesity and alcohol consumption were found to be prevalent among 13.97% of the study subjects. Among the biochemical parameters studied, hypertriglyceridemia was found to be prevalent in 22.05% followed by raised fasting blood sugar in 15.44% of the study subjects. Conclusion: Behaviour change communication strategies targeting these modifiable known high risk factors need to be emphasized to lower coronary heart disease (CHD related morbidity burden in the community.

  16. Analysis of potential oral cleft risk factors in the Kosovo population.

    Science.gov (United States)

    Salihu, Sami; Krasniqi, Blerim; Sejfija, Osman; Heta, Nijazi; Salihaj, Nderim; Geci, Agreta; Sejdini, Milaim; Arifi, Hysni; Isufi, Ramazan; Ueeck, Brett A

    2014-01-01

    The aim of this study was to analyze the association of potential risk factors such as positive family cleft history, smoking, use of drugs during pregnancy, and parental age with oral clefts in offspring within the Kosovo population. We conducted a population-based case-control study of live births in Kosovo from 1996 to 2005. Using a logistic regression model, 244 oral cleft cases were compared with 488 controls. We have excluded all syndromic clefts. Heredity increases the risk of clefts in newborns [odds ratio (OR) = 8.25, 95% confidence interval (CI) 3.12-23.52]. Clefts were also associated with smoking (OR = 1.87, 95% CI 0.75-4.08), use of drugs during pregnancy (OR = 2.25, 95% CI 0.82-5.12), increasing maternal age (OR = 1.83, 95% CI 1.42-2.49), and increasing paternal age (OR = 1.3, 95% CI 1.2- 1.4). We found heredity to be the most important factor for cleft occurrence in Kosovar newborns. Another significant potential risk factor for occurrence of clefts is the parental age. We found the use of drugs and smoking during pregnancy to be less significant.

  17. Malthusian factors as proximal drivers of human population crisis at Sub-Saharan Africa

    Directory of Open Access Journals (Sweden)

    Mauricio eLima

    2015-11-01

    Full Text Available There is a growing interest and concern for understanding the interaction among human population growth and the sustainability of natural resources. In fact, many agrarian societies experienced an increasing frequency of wars, famines and epidemics during the periods of resource depletion. People from Sub-Saharan Africa (SSA have suffered the demographic consequences of famines, civil wars and political instabilities during the last fifty years.. Almost half of the countries of Sub-Saharan Africa have undergone some form of demographic crisis over the past fifty years. Our analysis indicate that despite that environmental conditions were positively correlated with crop production across SSA, Malthusian factors correlated inversely with cultivation intensity, which in turn translated into a higher magnitude of depopulation suffered during the past fifty years. In this paper, we provide empirical evidence that population collapses in SSA during the last fifty years have been multifactorial, although more closely associated with Malthusian factors as proximal drivers. Other proximal drivers such as economic indicators, political stability and environmental determinants did not explain as much variance as Malthusian forces, suggesting that explanations of collapse magnitude in SSA are embedded in a complex multi-causal chain, in which demographic factors may play a modulating role yet to be explored in more depth.

  18. Smoldering multiple myeloma risk factors for progression: a Danish population-based cohort study.

    Science.gov (United States)

    Sørrig, Rasmus; Klausen, Tobias W; Salomo, Morten; Vangsted, Annette J; Østergaard, Brian; Gregersen, Henrik; Frølund, Ulf Christian; Andersen, Niels F; Helleberg, Carsten; Andersen, Kristian T; Pedersen, Robert S; Pedersen, Per; Abildgaard, Niels; Gimsing, Peter

    2016-09-01

    Several risk scores for disease progression in patients with smoldering multiple myeloma (SMM) have been proposed; however, all have been developed using single-center registries. To examine risk factors for time to progression (TTP) to multiple myeloma (MM) for SMM, we analyzed a nationwide population-based cohort of 321 patients with newly diagnosed SMM registered within the Danish Multiple Myeloma Registry between 2005 and 2014. Significant univariable risk factors for TTP were selected for multivariable Cox regression analyses. We found that both an M-protein ≥30 g/L and immunoparesis significantly influenced TTP (HR 2.7, 95%CI (1.5;4.7), P = 0.001, and HR 3.3, 95%CI (1.4;7.8), P = 0.002, respectively). High free light chain (FLC) ratio did not significantly influence TTP in our cohort. Therefore, our data do not support recent IMWG proposal of identifying patients with FLC ratio above 100 as having ultra high-risk of transformation to MM. Using only immunoparesis and M-protein ≥30 g/L, we created a scoring system to identify low-, intermediate-, and high-risk SMM. This first population-based study of patients with SMM confirms that an M-protein ≥30 g/L and immunoparesis remain important risk factors for progression to MM. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Using a factor mixture modeling approach in alcohol dependence in a general population sample.

    Science.gov (United States)

    Kuo, Po-Hsiu; Aggen, Steven H; Prescott, Carol A; Kendler, Kenneth S; Neale, Michael C

    2008-11-01

    Alcohol dependence (AD) is a complex and heterogeneous disorder. The identification of more homogeneous subgroups of individuals with drinking problems and the refinement of the diagnostic criteria are inter-related research goals. They have the potential to improve our knowledge of etiology and treatment effects, and to assist in the identification of risk factors or specific genetic factors. Mixture modeling has advantages over traditional modeling that focuses on either the dimensional or categorical latent structure. The mixture modeling combines both latent class and latent trait models, but has not been widely applied in substance use research. The goal of the present study is to assess whether the AD criteria in the population could be better characterized by a continuous dimension, a few discrete subgroups, or a combination of the two. More than seven thousand participants were recruited from the population-based Virginia Twin Registry, and were interviewed to obtain DSM-IV (Diagnostic and Statistical Manual of Mental Disorder, version IV) symptoms and diagnosis of AD. We applied factor analysis, latent class analysis, and factor mixture models for symptom items based on the DSM-IV criteria. Our results showed that a mixture model with 1 factor and 3 classes for both genders fit well. The 3 classes were a non-problem drinking group and severe and moderate drinking problem groups. By contrast, models constrained to conform to DSM-IV diagnostic criteria were rejected by model fitting indices providing empirical evidence for heterogeneity in the AD diagnosis. Classification analysis showed different characteristics across subgroups, including alcohol-caused behavioral problems, comorbid disorders, age at onset for alcohol-related milestones, and personality. Clinically, the expanded classification of AD may aid in identifying suitable treatments, interventions and additional sources of comorbidity based on these more homogenous subgroups of alcohol use

  20. Study of risk factors for gastric cancer by populational databases analysis.

    Science.gov (United States)

    Ferrari, Fangio; Reis, Marco Antonio Moura

    2013-12-28

    To study the association between the incidence of gastric cancer and populational exposure to risk/protective factors through an analysis of international databases. Open-access global databases concerning the incidence of gastric cancer and its risk/protective factors were identified through an extensive search on the Web. As its distribution was neither normal nor symmetric, the cancer incidence of each country was categorized according to ranges of percentile distribution. The association of each risk/protective factor with exposure was measured between the extreme ranges of the incidence of gastric cancer (under the 25(th) percentile and above the 75(th) percentile) by the use of the Mann-Whitney test, considering a significance level of 0.05. A variable amount of data omission was observed among all of the factors under study. A weak or nonexistent correlation between the incidence of gastric cancer and the study variables was shown by a visual analysis of scatterplot dispersion. In contrast, an analysis of categorized incidence revealed that the countries with the highest human development index (HDI) values had the highest rates of obesity in males and the highest consumption of alcohol, tobacco, fruits, vegetables and meat, which were associated with higher incidences of gastric cancer. There was no significant difference for the risk factors of obesity in females and fish consumption. Higher HDI values, coupled with a higher prevalence of male obesity and a higher per capita consumption of alcohol, tobacco, fruits, vegetables and meat, are associated with a higher incidence of gastric cancer based on an analysis of populational global data.

  1. [Extrinsic and intrinsic factors associated with mycotoxigenic fungi populations of maize grains (Zea mays L.) stored in silobags in Argentina].

    Science.gov (United States)

    Castellari, Claudia C; Cendoya, María G; Marcos Valle, Facundo J; Barrera, Viviana; Pacin, Ana M

    2015-01-01

    In order to determine the behavior of mycotoxin-producing fungal populations linked with silobags stored corn grains with a moisture content greater at the recommended as safe, 270 samples taken in three times (beginning, 90 days, final) over a five month period of storage were evaluated. The fungal biota was quantified and identified and the contamination with fumonisin and aflatoxin was determined. Extrinsic factors (environment), intrinsic factors (grains) and technological factors (location of the grains in the profile of silobag) were taken into account to evaluate the presence and quantity of total and mycotoxigenic fungal populations. The pH of grains and O2 levels were significantly reduced after five months, while CO2 concentration increased in the same period. The total counts of mycobiota were significantly higher in grains located in the top layer of silobag. Mycotoxigenic species of Fusarium, Aspergillus, Penicillium and Eurotium were identified. The frequency of isolation of Fusarium verticillioides decreased at the end of storage and Aspergillus flavus was isolated only at the beginning of storage. The counts of the Penicillium spp. and Eurotium spp. were increased at the end of storage. Fumonisin contamination was found in all the samples (100%) with maximum levels of 5.707mg/kg whereas aflatoxin contaminated only 40% with maximum levels of 0.0008mg/kg. The environmental and substrate conditions generated during the storage limited the development of mycotoxigenic fungi and mycotoxin production. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

  2. Factors influencing postoperative mortality one year after surgery for hip fracture in Chinese elderly population

    Institute of Scientific and Technical Information of China (English)

    LI Shao-guang; SUN Tian-sheng; LIU Zhi; REN Ji-xin; LIU Bo; GAO Yang

    2013-01-01

    Background Disability and death following hip fracture is becoming more common as the population ages.Previous reports have focused on the selection of internal fixation methods and the analysis of the perioperative therapeutic results in the Chinese population.Few studies have focused on factors influencing medium and long term survival after surgery for hip fracture.We conducted a retrospective study on the factors influencing survival one year after hip fracture surgery in our elderly Chinese population to provide a reference for improved treatment and to enhance efficacy.Methods Records from patients undergoing treatment for hip fracture at our hospital from October 2009 through June 2011 were retrospectively reviewed.Through telephone follow-up,the health condition of each patient was surveyed,and the 1-year postoperative mortality was analyzed.The patients' age,gender,fracture type,pre-injury health condition,mobility,complications,surgical timing,surgical types,methods of anesthesia,and postoperative complications were analyzed.Univariate and multivariate regression analysis was performed on relevant influencing factors.Results A total of 184 patients had complete data and were followed-up for 12-23 months (average,16.5 months).There were 30 deaths (16.3%) at one-year.Univariate analysis revealed that factors such as age,gender,fracture-type,number of co-existing diseases,complications such as chronic obstructive pulmonary disease or sequelae of stroke,American society of Anesthesiology (ASA) scores,anesthesia methods,pre-injury activity,and post-operative complications were significantly different between survival versus mortality groups (P <0.05).Multivariate regression analysis revealed that age,ASA score,pre-injury mobility and combined chronic obstructive pulmonary disease were independent risk factors for death.Conclusion Full consideration of medium-/long-term risk factors in the treatment of hip fracture in the elderly,selection of appropriate

  3. Effect of predictor traits on accuracy of genomic breeding values for feed intake based on a limited cow reference population.

    Science.gov (United States)

    Pszczola, M; Veerkamp, R F; de Haas, Y; Wall, E; Strabel, T; Calus, M P L

    2013-11-01

    The genomic breeding value accuracy of scarcely recorded traits is low because of the limited number of phenotypic observations. One solution to increase the breeding value accuracy is to use predictor traits. This study investigated the impact of recording additional phenotypic observations for predictor traits on reference and evaluated animals on the genomic breeding value accuracy for a scarcely recorded trait. The scarcely recorded trait was dry matter intake (DMI, n = 869) and the predictor traits were fat-protein-corrected milk (FPCM, n = 1520) and live weight (LW, n = 1309). All phenotyped animals were genotyped and originated from research farms in Ireland, the United Kingdom and the Netherlands. Multi-trait REML was used to simultaneously estimate variance components and breeding values for DMI using available predictors. In addition, analyses using only pedigree relationships were performed. Breeding value accuracy was assessed through cross-validation (CV) and prediction error variance (PEV). CV groups (n = 7) were defined by splitting animals across genetic lines and management groups within country. With no additional traits recorded for the evaluated animals, both CV- and PEV-based accuracies for DMI were substantially higher for genomic than for pedigree analyses (CV: max. 0.26 for pedigree and 0.33 for genomic analyses; PEV: max. 0.45 and 0.52, respectively). With additional traits available, the differences between pedigree and genomic accuracies diminished. With additional recording for FPCM, pedigree accuracies increased from 0.26 to 0.47 for CV and from 0.45 to 0.48 for PEV. Genomic accuracies increased from 0.33 to 0.50 for CV and from 0.52 to 0.53 for PEV. With additional recording for LW instead of FPCM, pedigree accuracies increased to 0.54 for CV and to 0.61 for PEV. Genomic accuracies increased to 0.57 for CV and to 0.60 for PEV. With both FPCM and LW available for evaluated animals, accuracy was highest (0.62 for CV and 0.61 for PEV in

  4. [Factors Associated with Cognitive Decline in a Population Less than 65 Years Old. A Systematic Review].

    Science.gov (United States)

    Aguirre-Acevedo, Daniel Camilo; Henao, Eliana; Tirado, Victoria; Muñoz, Claudia; Giraldo Arango, Diana; Lopera Restrepo, Francisco; Jaimes Barragán, Fabián

    2014-01-01

    Cognitive decline could begin 20 years before the diagnosis of dementia. Besides age, several factors related to medical, socioeconomic, and behavioral and genetic condition may be associated with cognitive decline. The aim of this systematic review was to summarize evidence on the risk and protective factors for cognitive decline in people under 65 years old. A systematic review was conducted using a search strategy in MEDLINE and Embase, including longitudinal studies to analyze the effect of protective or risk factors on cognitive decline in a population under 65 years old. A total of 22 studies were included in this review. Factors such as diabetes, hyperinsulinemia, overweight or obesity, metabolic syndrome, education, physical activity, cognitive stimulation, marital status and diet, could be related to cognitive decline before 65 years of age. Cardiovascular risk factors and lifestyle conditions may be associated with cognitive decline before 65 years of age. However, the quality of the evidence was low. Copyright © 2013 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  5. Climate factors play a limited role for past adaptation strategies in West Africa

    DEFF Research Database (Denmark)

    Mertz, Ole; Mbow, Cheikh; Nielsen, Jonas Østergaard;

    2010-01-01

    The Sudano-Sahelian zone of West Africa has experienced recurrent droughts since the mid-1970s and today there is considerable concern for how this region will be able to adapt to future climate change. To develop well targeted adaptation strategies, the relative importance of climate factors...... to be reflected in national adaptation strategies in the region....

  6. Bethe ansatz matrix elements as non-relativistic limits of form factors of quantum field theory

    NARCIS (Netherlands)

    Kormos, M.; Mussardo, G.; Pozsgay, B.

    2010-01-01

    We show that the matrix elements of integrable models computed by the algebraic Bethe ansatz (BA) can be put in direct correspondence with the form factors of integrable relativistic field theories. This happens when the S-matrix of a Bethe ansatz model can be regarded as a suitable non-relativistic

  7. Climate factors play a limited role for past adaptation strategies in West Africa

    DEFF Research Database (Denmark)

    Mertz, Ole; Mbow, Cheikh; Nielsen, Jonas Østergaard

    2010-01-01

    The Sudano-Sahelian zone of West Africa has experienced recurrent droughts since the mid-1970s and today there is considerable concern for how this region will be able to adapt to future climate change. To develop well targeted adaptation strategies, the relative importance of climate factors as ...

  8. Individual and environmental factors determining sedentary lifestyle of the polish population.

    Science.gov (United States)

    Biernat, Elżbieta; Piątkowska, Monika

    2014-08-01

    The aim of the current investigation was to evaluate the sedentary lifestyle of the Polish population and its link with prolonged sitting in light of individual and environmental factors. The sample consisted of 1505 Polish people between 18 and 64 years old. The Computer-Assisted Telephone Interview (CATI) survey was conducted with the Polish version of International Physical Activity Questionnaire (IPAQ-LF) and the survey of the determinants of a sport activity among the Polish population. The relationships between the time spent sitting and the individual and environmental factors among Polish citizens were investigated through log-linear analysis. The total time Polish people spent sitting was 2812.4±1593.9 min/week. During the weekend, men (Chi(2)=45.0; P=0.04) spent significantly more time sitting than women (251.1±170.1min/week, 230.9±155.0 min/week, respectively). Despite the relatively high proportion of people declaring participation in the Sport for All initiative (67.8%), only 9.6% of Polish people undertake a physical activity on a daily basis. The odds ratios above the median (>2545 min/week) are higher (OR=1.33; 95% CI=1.03-1.72) for those who are not physically active (54.5% vs. 45.5%). There was no relationship between prolonged sitting time and the environmental factors. It is necessary to increase consistent efforts to create an environment that would successfully promote anactive lifestyle among Polish citizens in their place of residence and prevent sedentary behaviours within this population. The recommendations for physical activity should include the guidelines intervening in the time people spend sitting.

  9. Risky sexual behavior among rural female adolescents in Malaysia: a limited role of protective factors.

    Science.gov (United States)

    Ahmadian, Maryam; Hamsan, Hanina H; Abdullah, Haslinda; Samah, Asnarulkhadi Abu; Noor, Amna Md

    2014-03-23

    This paper presents the findings of a cross-sectional survey on the risk and protective factors of premarital sexual behavior among rural female adolescents in Peninsular Malaysia. We investigated data on 770 female respondents aged 13-17 years in rural areas to identify predictive factors for premarital sexual intercourse. Data were analyzed using bivariate and multivariate regression. Specific socio-demographic factors, psychological and family domains, peer delinquency, and knowledge and attitudes about sexuality were considered in risky sexual behaviors in rural Malay girls. The effects of other covariates for premarital sexual intercourse were controlled by logistic regression model. Of the 770 rural female students, about 3.2% of respondents reported experience of sexual intercourse in the past three months. Out of those sexually active girls, 36% were 17 years old and 20% stated having sexual intercourse with more than one partner, and 72% did not use contraception during the most recent sexual intercourse. Midnight activities, peer-sexual disorder, self-evaluation, and attitude toward sexual health were significant predictors of sexual intercourse in rural girls in Malaysia. The finding highlights the impact of psychological factors and peer group influences on the challenges of premarital sexual behavior among rural girls and the notion of school-based sexual health education for adolescents. This study triggers other researchers take into account a comprehensive view of protective factors operating in adolescents' risky sexual behaviors in Asian culture seeing that family domain variables, unexpectedly, exerted no predicting influence on sexually active female teens in rural areas in Malaysia.

  10. Endogamia e limite de seleção em populações selecionadas obtidas por simulação Inbreeding and selection limit in selected population obtained by simulation

    Directory of Open Access Journals (Sweden)

    Fernanda Cristina Breda

    2004-12-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o comportamento do coeficiente de endogamia e do limite de seleção considerando população-base selecionada. Utilizou-se o programa GENESYS para a simulação do genoma constituído de uma única característica quantitativa com valor de herdabilidade igual a 0,40, população-base, população inicial e populações sob seleção. Foram consideradas três gerações distintas como gerações bases, gerações zero (G0PB, três (G3PB e sete (G7PB. As populações foram selecionadas a partir dos valores genéticos obtidos pelo melhor preditor linear não-viesado (BLUP e com base no desempenho individual, sendo considerados: a dois tamanhos efetivos de população (Ne1 = 38,09 e Ne2 = 88,88 e b dois sistemas de acasalamentos dos reprodutores selecionados (reprodutores acasalados aleatoriamente - RAA e exclusão de irmãos completos - EIC. Os parâmetros avaliados foram: coeficiente médio de endogamia, percentagem de locos fixados favoravelmente e limite de seleção. A não-utilização da população-base verdadeira (G0PB subestimou os coeficientes de endogamia. As populações que utilizaram as gerações três e sete como base apresentaram as mesmas taxas de fixação de alelos favoráveis e os mesmos valores do limite de seleção das populações que consideraram a G0PB.Objective was to evaluate the behavior average inbreeding coefficient associated to the selection limit considering selected population as base population. GENESYS program was used for simulation of the genome (one trait of h² = 0.40, base population, initial population and populations under selection. Three different generations were considered as base generations, zero (G0PB, three (G3PB and seven (G7PB. Populations were selected based on best linear unbiased predictor (BLUP and on individual phenotype in which were considered: a two effective population sizes (Ne1 = 38.09 and Ne2 = 88.88 and b two mating systems (random mating

  11. Regional and Gender Differences in Years with and without Mobility Limitation in the Older Population of Thailand.

    Directory of Open Access Journals (Sweden)

    Benjawan Apinonkul

    Full Text Available To examine gender and regional differences in health expectancies based on the measure of mobility.Health expectancies by gender and region were computed by Sullivan's method from the fourth Thai National Health Examination Survey (2009. A total of 9,210 older persons aged 60 years and older were included. Mobility limitation was defined as self-reporting of ability to perform only with assistances/aids at least one of: walking at least 400 metres; or going up or down a flight of 10 stairs. Severe limitation was defined as complete inability to do at least one of these two functions, even with assistances or aids.At age 60, females compared to males, spent significantly fewer years without mobility limitation (male-female = 3.2 years and more years with any limitation (female-male = 6.7 years and with severe limitation (female-male = 3.2 years. For both genders, years lived with severe limitation were remarkably constant across age. Significant regional inequalities in years lived without and with limitation were evident, with a consistent pattern by gender in years free of mobility limitation (Central ranked the best and the North East ranked the worst. Finally, both males and females in the South had the longest life expectancy and the most years of life with severe mobility limitation.This study identifies inequalities in years without and with mobility limitations with important policy implication.

  12. Pigment epithelium-derived factor (PEDF): a novel trophoblast-derived factor limiting feto-placental angiogenesis in late pregnancy.

    Science.gov (United States)

    Loegl, Jelena; Nussbaumer, Erika; Hiden, Ursula; Majali-Martinez, Alejandro; Ghaffari-Tabrizi-Wizy, Nassim; Cvitic, Silvija; Lang, Ingrid; Desoye, Gernot; Huppertz, Berthold

    2016-07-01

    The rapidly expanding feto-placental vasculature needs tight control by paracrine and endocrine mechanisms. Here, we focused on paracrine influence by trophoblast, the placental epithelium. We aimed to identify differences in regulation of feto-placental angiogenesis in early versus late pregnancy. To this end, the effect of conditioned media (CM) from early and late pregnancy human trophoblast was tested on network formation, migration and proliferation of human feto-placental endothelial cells. Only CM of late pregnancy trophoblast reduced network formation and migration. Screening of trophoblast transcriptome for anti-angiogenic candidates identified pigment epithelium-derived factor (PEDF) with higher expression and protein secretion in late pregnancy trophoblast. Addition of a PEDF-neutralizing antibody restored the anti-angiogenic effect of CM from late pregnancy trophoblast. Notably, human recombinant PEDF reduced network formation only in combination with VEGF. Also in the CAM assay, the combination of PEDF with VEGF reduced branching of vessels below control levels. Analysis of phosphorylation of ERK1/2 and FAK, two key players in VEGF-induced proliferation and migration, revealed that PEDF altered VEGF signaling, while PEDF alone did not affect phosphorylation of ERK1/2 and FAK. These data suggest that the trophoblast-derived anti-angiogenic molecule PEDF is involved in restricting growth and expansion of the feto-placental endothelium predominantly in late pregnancy and targets to modulate the intracellular effect of VEGF.

  13. The association between aortic augmentation index and cardiovascular risk factors in a large unselected population

    DEFF Research Database (Denmark)

    Janner, Julie Hjortsø; Godtfredsen, N S; Ladelund, S

    2011-01-01

    . Therefore, the aim of the present study is to examine the association's consistency at different ages and to see if the associations are the same in men and women. This study is based on 3432 subjects from The Copenhagen City Heart Study, a prospective epidemiological survey of a representative population......, height and systolic blood pressure in both age groups with few gender differences. Associations between AIx and cardiovascular risk factors further differed by age: In young subjects AIx was associated with cholesterol, high-sensitive C-reactive protein, current smoking, low weight, poor education...

  14. NO ASSOCIATION BETWEEN TUMOR NECROSIS FACTOR ALPHA AND OBSESSIVE COMPULSIVE DISORDER IN CHINESE HAN POPULATION

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Objective To investigate association between tumor necrosis factor alpha (TNF-α) and obsessive compulsive disorder (OCD) in Chinese Han population.Methods Plasma concentrations of TNF-α were measured in 61 drug-free patients who fulfilled DSM-Ⅳ criteria for OCD and 93 healthy controls.TNF-α concentrations in blood were determined by enzyme-linked immunosorbent assay (ELISA).Two polymorphisms of TNF-α gene were investigated in the same patients and healthy controls:-308 G/A and-238 G/A.The allelic and genoty...

  15. Risk Factors for Survival in a University Hospital Population of Dogs with Epilepsy

    DEFF Research Database (Denmark)

    Fredso, N.; Koch, B. C.; Toft, Nils

    2014-01-01

    BackgroundAlthough a common neurological disorder in dogs, long-term outcome of epilepsy is sparsely documented. ObjectivesTo investigate risk factors for survival and duration of survival in a population of dogs with idiopathic epilepsy or epilepsy associated with a known intracranial cause....... AnimalsOne hundred and two client owned dogs; 78 dogs with idiopathic epilepsy and 24 dogs with epilepsy associated with a known intracranial cause. MethodsA retrospective hospital based study with follow-up. Dogs diagnosed with epilepsy between 2002 and 2008 were enrolled in the study. Owners were...

  16. Correlations of health behaviors and factors with high sensitivity C-reactive protein in diabetic population

    Directory of Open Access Journals (Sweden)

    Jin-hong HOU

    2013-11-01

    Full Text Available Objective To explore the correlations of ideal cardiovascular health behaviors and factors with the level of high sensitivity C-reactive protein (hsCRP in diabetic population. Methods A cross-sectional method was used in present study. Seven thousand eight hundred and sixty-nine workers with diabetes were recruited who participated in the 2006-2007 Kailuan health examination without history of cerebral and myocardial infarction and without data incompleted. All the information was obtained from the unified questionnaire and measurement of blood biochemistry. Multivariate logistic regression analysis was used to analyze the effects of ideal cardiovascular health behaviors and factors on the level of hsCRP. Results The hsCRP concentrations decreased with the increasing numbers of ideal cardiovascular health behaviors and factors, the medians of hsCRP concentrations were 1.16mg/L, 1.11mg/L, 0.90mg/L and 0.76mg/L in 0-1, 2, 3 and 4-6 ideal cardiovascular health groups, respectively (P<0.01. Multivariate logistic regression analysis showed that, after adjustment by age, gender, triglyceride, low density lipoprotein cholesterol (LDL-C and high density lipoprotein cholesterol (HDL-C, the risk of hsCRP level exceeding 3mg/L in the subjects having 3 and 4-6 ideal cardiovascular health behaviors and factors was 0.60 times (95%CI 0.50-0.72 and 0.45 times (95%CI 0.34-0.61, respectively, than those having 0-1 ideal cardiovascular health behaviors and factors. Conclusion The hsCRP concentrations decreased with increasing numbers of ideal cardiovascular health behaviors and factors; the risk of hsCRP exceeding 3mg/L can be reduced by ideal cardiovascular health behaviors and factors. DOI: 10.11855/j.issn.0577-7402.2013.10.013

  17. Toxic volatile organic compounds in environmental tobacco smoke: Emission factors for modeling exposures of California populations

    Energy Technology Data Exchange (ETDEWEB)

    Daisey, J.M.; Mahanama, K.R.R.; Hodgson, A.T. [Lawrence Berkeley Lab., CA (United States)

    1994-10-01

    The primary objective of this study was to measure emission factors for selected toxic air contaminants in environmental tobacco smoke (ETS) using a room-sized environmental chamber. The emissions of 23 volatile organic compounds (VOCs), including, 1,3-butadiene, three aldehydes and two vapor-phase N-nitrosamines were determined for six commercial brands of cigarettes and reference cigarette 1R4F. The commercial brands were selected to represent 62.5% of the cigarettes smoked in California. For each brand, three cigarettes were machine smoked in the chamber. The experiments were conducted over four hours to investigate the effects of aging. Emission factors of the target compounds were also determined for sidestream smoke (SS). For almost all target compounds, the ETS emission factors were significantly higher than the corresponding SS values probably due to less favorable combustion conditions and wall losses in the SS apparatus. Where valid comparisons could be made, the ETS emission factors were generally in good agreement with the literature. Therefore, the ETS emission factors, rather than the SS values, are recommended for use in models to estimate population exposures from this source. The variabilities in the emission factors ({mu}g/cigarette) of the selected toxic air contaminants among brands, expressed as coefficients of variation, were 16 to 29%. Therefore, emissions among brands were Generally similar. Differences among brands were related to the smoked lengths of the cigarettes and the masses of consumed tobacco. Mentholation and whether a cigarette was classified as light or regular did not significantly affect emissions. Aging was determined not to be a significant factor for the target compounds. There were, however, deposition losses of the less volatile compounds to chamber surfaces.

  18. Application of Semiparametric Spline Regression Model in Analyzing Factors that In uence Population Density in Central Java

    Science.gov (United States)

    Sumantari, Y. D.; Slamet, I.; Sugiyanto

    2017-06-01

    Semiparametric regression is a statistical analysis method that consists of parametric and nonparametric regression. There are various approach techniques in nonparametric regression. One of the approach techniques is spline. Central Java is one of the most densely populated province in Indonesia. Population density in this province can be modeled by semiparametric regression because it consists of parametric and nonparametric component. Therefore, the purpose of this paper is to determine the factors that in uence population density in Central Java using the semiparametric spline regression model. The result shows that the factors which in uence population density in Central Java is Family Planning (FP) active participants and district minimum wage.

  19. Forecasting the Optimal Factors of Formation of the Population Savings as the Basis for Investment Resources of the Regional Economy

    Directory of Open Access Journals (Sweden)

    Odintsova Tetiana M.

    2017-04-01

    Full Text Available The article is aimed at studying the optimal factors of formation of the population savings as the basis for investment resources of the regional economy. A factorial (nonlinear correlative-regression analysis of the formation of savings of the population of Ukraine was completed. On its basis a forecast of the optimal structure and volumes of formation of the population incomes was carried out taking into consideration impact of fundamental factors on these incomes. Such approach provides to identify the marginal volumes of tax burden, population savings, and capital investments, directed to economic growth.

  20. Covariant quark model of form factors in the heavy mass limit

    OpenAIRE

    Yaouanc, A. Le; Oliver, L; Pène, O.; Raynal, J. -C.

    1995-01-01

    We show that quark models of current matrix-elements based on the Bakamjian-Thomas construction of relativistic states with a fixed number of particles, plus the additivity assumption, are covariant in the heavy-quark limit and satisfy the full set of heavy-quark symmetry relations discovered by Isgur and Wise. We find the lower bound of $\\rho^2$ in such models to be $3/4$ for ground state mesons, independently of any parameter. Another welcome property of these models is that in the infinite...

  1. Theory of factors limiting high gradient operation of warm accelerating structures

    Energy Technology Data Exchange (ETDEWEB)

    Nusinovich, Gregory S. [Univ. of Maryland, College Park, MD (United States)

    2014-07-22

    This report consists of two parts. In the first part we describe a study of the heating of microprotrusions on surfaces of accelerating structures. This ;process is believed to lead to breakdown in these structures. Our study revealed that for current accelerator parameters melting should not occur due to space charge limitations of the current emitted by a protrusion. The second part describes a novel concept to develop THz range sources based on harmonic cyclotron masers for driving future colliders. This work was stimulated by a recent request of SLAC to develop high power, high-efficiency sources of sub-THz radiation for future high-gradient accelerators.

  2. Feeding the world's increasing population while limiting climate change impacts; decoupling agriculture' s N2O and CH4 emissions from population growth

    NARCIS (Netherlands)

    Beek, C.L.; Meerburg, B.G.; Schils, R.L.M.; Verhagen, J.; Kuikman, P.J.

    2010-01-01

    The global demand for agricultural products, including food, is rapidly increasing due to population growth and shifts in consumption patterns. The required increase in agricultural production is predominantly to be achieved in countries with relatively low agricultural production levels at present.

  3. On limitation of quality factor of single mode resonators with finite size

    CERN Document Server

    Ferdous, Fahmida; Vyatchanin, Sergey P; Matsko, Andrey B; Maleki, Lute

    2014-01-01

    Using realistic numerical models we analyze radiative loss of bound and unbound modes of specially designed high-Q whispering gallery and Fabry-Perot cavities of similar size and shape, and find a set of parameters when they can be treated as single mode structures. We show that these cavities have similar properties in spite of their different loss mechanisms. The cavity morphology engineering does not lead to reduction of the resonator quality factor.

  4. Physical and psychosocial risk factors for lateral epicondylitis: a population based case-referent study

    DEFF Research Database (Denmark)

    Haahr, J. P.; Andersen, JH

    2003-01-01

    AIMS: To assess the importance of physical and psychosocial risk factors for lateral epicondylitis (tennis elbow). METHODS: Case-referent study of 267 new cases of tennis elbow and 388 referents from the background population enrolled from general practices in Ringkjoebing County, Denmark. RESULTS......: Manual job tasks were associated with tennis elbow (odds ratio (OR) 3.1, 95% confidence interval (CI) 1.9 to 5.1). The self reported physical risk factors "posture" and "forceful work" were related to tennis elbow. Among women, work involving performing repeated movements of the arms was related...... to tennis elbow (OR 3.7, CI 1.7 to 8.3). Among men, work with precision demanding movements was related to tennis elbow (OR 5.2, CI 1.5 to 17.9). Among both males and females, the results for work with hand held vibrating tools were inconsistent, partly because of few exposed subjects. A physical strain...

  5. Factors associated with clinical gallbladder disease in a Canadian Indian population.

    Science.gov (United States)

    Young, T K; Roche, B A

    1990-04-01

    Among the Cree-Ojibwa Indians in the subarctic boreal forest of northern Manitoba and Ontario, a high prevalence of clinical gallbladder disease (18.5% among women aged 20-64) was observed. Of a variety of sociodemographic, physiological, anthropometric, and lifestyle factors, increased age and serum triglycerides, and reduced total cholesterol were found to be independent associated factors on multivariate analysis whereas diabetic status, obesity, and a central fat distribution were not. Previous studies in this population have indicated that the Indians also suffer from a high burden of obesity, diabetes, and gallbladder cancer, thus lending support to the hypothesis that genetic predisposition to a constellation of metabolic disorders is perhaps universal among New World aboriginal peoples.

  6. Pollen and resource limitations to lifetime seed production in a wild population of the endangered plant Disanthus cercidifollus var.Iongipes H.T.Chang (Hamamelidaceae)

    Institute of Scientific and Technical Information of China (English)

    XIAO Yian; HE Ping; ZENG Jianjun; LI Xiaohong; HU Wenhai

    2007-01-01

    Disanthus cercidifolius Maxim.var.longipes H.T.Chang,a plant species that only occurs in a few counties in Hunan,Jiangxi and Zhejiang Provinces and with a relatively small number of individuals,is ranked as a second Class endangered species for conservation in China.We have studied the effect of pollen and resources available to female reproduction,and the reproductive mechanism of "excess flowers with low fruit set" in Disanthus cercidifolius Maxim.var.longipes H.T.Chang was discussed.Results are as follows:Pollen from different sources has significant effects on fruit set and seed set of Disanthus cercidifolius Maxim.var.longipes H.T.Chang.The pollen source rather than pollen numbers significantly affected reproduction of this species.In wild populations,producing one fruit needs about 54.8 flowers,and one satiation seed needs about 6.60 flowers or 83.19 ovules.After fertilizing,which was propitious to flower development,the abortion rate of flower buds was decreasing,but the flowering rate was increasing.The fruit set and seed set was also significantly increasing,while abortion rate of fruit was significantly decreasing.With the increasing percentages of cutting leaves,the fruit set decreased,but the abortion rate of fruit shows no significant differentiation among treatments.After cutting branches that were puny,broken and insectinfested branches,the flower number seemed to be decreasing,but the fruit set and seed set all increased significantly.After removing some flowers,the fruit set was calculated with respect to the number of flowers remaining after the treatment increased with increasing of percentages of flower removal,whereas fruit set calculated with respect to the initial number of flowers remained constant,and the mean weights of per fi'uit and per seed all decreased significantly.Sufficient spatial or temporal heterogeneities in nutrient levels might allow limitation of seed set by resources and pollen in a natural population,while supplying

  7. Continuum limit of the leading order HQET form factor in B{sub s}→Klν decays

    Energy Technology Data Exchange (ETDEWEB)

    Bahr, Felix; Banerjee, Debasish; Koren, Mateusz; Simma, Hubert; Sommer, Rainer [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Bernardoni, Fabio [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany). John von Neumann-Inst. fuer Computing NIC; Technische Univ. Dresden (Germany). Medizinische Fakultaet ' ' Carl Gustav Carus' ' ; Joseph, Anosh [Cambridge Univ. (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics (DAMTP); Collaboration: ALPHA Collaboration

    2016-01-15

    We discuss the computation of form factors for semi-leptonic decays of B-, B{sub s}- mesons in lattice QCD. Considering in particular the example of the static B{sub s} form factors we demonstrate that after non-perturbative renormalization the continuum limit can be taken with confidence. The resulting precision is of interest for extractions of V{sub ub}. The size of the corrections of order 1/m{sub b} is just estimated at present but it is expected that their inclusion does not pose significant difficulties.

  8. [Aortic valve calcification prevalence and association with coronary risk factors and atherosclerosis in Mexican population].

    Science.gov (United States)

    Acuña-Valerio, Jorge; Rodas-Díaz, Marco A; Macias-Garrido, Enrico; Posadas-Sánchez, Rosalinda; Juárez-Rojas, Juan G; Medina-Urrutia, Aida X; Cardoso-Saldaña, Guillermo C; Joge-Galarza, Esteban; Torres-Tamayo, Margarita; Vargas-Alarcón, Gilberto; Posadas-Romero, Carlos

    The prevalence of aortic valve calcification (AVC), strongly influenced by ethnicity, is unknown in Mexican population. The aim of this study was to investigate the prevalence of AVC and its associations with cardiovascular risk factors and coronary artery calcification (CAC), in Mexican subjects. In 1,267 subjects (53% women) without known coronary heart disease, aged 35 to 75 years, AVC and CAC were assessed by multidetector-computed tomography using the Agatston score. Cardiovascular risk factors were documented in all participants. The associations of AVC with CAC and risk factors were assessed by multivariable logistic regression analyses. The overall prevalence of AVC and CAC was 19.89% and 26.5%, respectively. AVC and CAC increased with age and were found more frequently in men (25.5% and 37.1%, respectively) than in women (14.9% and 13.0%, respectively). AVC was observed in only 8.5% of subjects without CAC, while those with CAC 1-99, 100-399, and >400 Agatston units had AVC prevalences of 36.8%, 56.8%, and 84.0%, respectively. The multivariable logistic regression analyses, adjusted for age, gender, obesity, physical inactivity, hypertension, dyslipidemia and high insulin levels, showed that the presence of CAC (OR [CI95%]: 3.23 [2.26-4.60]), obesity (1.94 [1.35-2.79]), male gender (1.44 [1.01-2.05]) and age (1.08 [1.03-1.10]), were significant independent predictors of AVC. Prevalence of AVC is high and significantly associated with atherosclerotic risk factors and CAC in this Mexican population. Copyright © 2016 Instituto Nacional de Cardiología Ignacio Chávez. Publicado por Masson Doyma México S.A. All rights reserved.

  9. Children's health and parental socioeconomic factors: a population-based survey in Finland

    Directory of Open Access Journals (Sweden)

    Savolainen Piia H

    2011-06-01

    Full Text Available Abstract Background Socioeconomic inequalities in health are a global problem, not only among the adult population but also among children. However, studies concerning young children especially are rare. The aim of this study was to describe the health of Finnish children under 12 years of age, and the socioeconomic factors associated with health. The socioeconomic factors were parental education level, household net income, and working status. Methods A population-based survey among Finnish children aged under 12 years (n = 6,000 was conducted in spring 2007. A questionnaire was sent to parents, and a response rate of 67% was achieved. Each child's health was explored by asking a parent to report the child's health status on a 5-point Likert scale, current symptoms from a symptoms list, and current disease(s diagnosed by a physician. The final three outcome measures were poor health, the prevalences of psychosomatic symptoms, and long-term diseases. Data were analysed using Pearson's Chi-Square tests, and logistic regression analysis with 95% confidence intervals (CIs. P-values ≤0.05 were considered as statistically significant. Results In total, 3% of parents reported that their child's health status was poor. The prevalences of psychosomatic symptoms and long-term diseases were both 11%. The probability for poor health status was lowest among children aged 3-6 and 7-11 years, and for psychosomatic symptoms among 3-6-year-old children, whereas the odds ratios for long-term diseases was highest among children aged 7-11 years. Parental socioeconomic factors were not associated with the children's health. Conclusions Most of the children were reported by their parent to have good health status, and approximately one tenth had experienced some psychosomatic symptoms or long-term diseases. Our study suggests that parental socioeconomic factors are not associated with the health of children aged under 12 years in Finland.

  10. Risk factors for multiple sclerosis in Kuwait: a population-based case-control study.

    Science.gov (United States)

    Al-Afasy, Hanan H; Al-Obaidan, Mohammed A; Al-Ansari, Yousef A; Al-Yatama, Sarah A; Al-Rukaibi, Mohammed S; Makki, Nourah I; Suresh, Anita; Akhtar, Saeed

    2013-01-01

    Multiple sclerosis (MS) is a chronic and progressively disabling inflammatory autoimmune disorder of the central nervous system. MS has a multifactorial etiology and is triggered by environmental factors in individuals with complex genetic risk profiles. The epidemiology of MS changes with the spatial and temporal distribution of these genetic and nongenetic risk factors. This population-based matched case-control study aimed to determine the risk factors for MS in Kuwait. From May 2 to 9, 2010, we enrolled 101 confirmed MS cases using the list frame maintained by the Multiple Sclerosis Association of Kuwait. For each case, two population controls individually matched for age (±2 years), gender and nationality were selected. Data on demographic, socioeconomic variables, potential genetic and environmental factors were collected using a structured questionnaire. For a case, the questions were directed to the period that preceded the recognition of the disease, while for each of the two matched controls, a date of 'pseudodiagnosis' of MS was established, i.e. the date on which the control subject was of the same age as his/her matched case was at MS diagnosis and accordingly questions were directed to the preceding period. The multivariable conditional logistic regression model showed that compared with controls, the cases were significantly more likely to have a family history of MS [matched odds ratio (OR)(adj) = 6.7; 95% confidence interval (95% CI): 2.5-18.0; p Kuwait during the Iraqi invasion of 1990 (matched OR(adj) = 1.8; 95% CI: 1.1-3.5; p = 0.022). This study showed that a family history of MS, a history of head injury, and presence in Kuwait at the time of the Iraqi invasion of 1990 were associated with a significantly increased MS risk. Future retrospective cohort studies by using existing biological and epidemiological databases may provide a clue to MS etiology.

  11. Factors affecting burden on caregivers of stroke survivors: Population-based study in Mumbai (India

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    Madhumita Bhattacharjee

    2012-01-01

    Full Text Available Background: Caring for stroke patients leads to caregiver (CG strain. The aims of this study are to identify factors related to increased CG burden in stroke survivors in a census-defined population and to assess the relationship between patient characteristics and CG stress. Materials and Methods: In a prospective population-based study, 223 first ever stroke (FES were identified over a 1-year period. At 28 days, 127 (56.9% were alive and 79 (35% died, and 17 were lost to follow-up. One hundred and eleven CGs of 127 FES survivors agreed to participate. The level of stress was assessed by two scales: Oberst Caregiving Burden Scale (OCBS and the Caregivers Strain Index (CSI in CGs of survivors with mild stroke Modified Rankin Scale (MRS 1-2 and in those with significant disability (MRS 3-5. Results: The mean age of CGs was 45.6 years, approximately 22 years younger than that of the patients (67.5 years. Eighty-nine (80% of the CGs were females and only 22 (20% were males. Urinary incontinence (P=0.000008, morbidity at 28 days by MRS (P=0.0051, female gender (P=0.0183 and moderate to severe neurological deficit by National Institute of Health Stroke Scale (NIHSS on admission (P=0.0254 were factors in FES cases leading to major CGs stress. CG factors responsible for major stress were long caregiving hours (P≤0.000001, anxiety (P≤0.000001, disturbed night sleep ( P≤0.000001, financial stress (P=0.0000108, younger age (P=0.0021 and CGs being daughter-in-laws (P=0.012. Conclusion: Similar studies using uniform methodologies would help to identify factors responsible for major CG stress. Integrated stroke rehabilitation services should address CG issues to local situations and include practical training in simple nursing skills and counseling sessions to help reduce CG burden.

  12. Prevalence of metabolic syndrome: association with risk factors and cardiovascular complications in an urban population.

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    Gisela Cipullo Moreira

    Full Text Available INTRODUCTION: Metabolic syndrome (MS is a set of cardiovascular risk factors and type 2 diabetes, responsible for a 2.5-fold increased cardiovascular mortality and a 5-fold higher risk of developing diabetes. OBJECTIVES: 1-to evaluate the prevalence of MS in individuals over 18 years associated with age, gender, socioeconomic status, educational levels, body mass index (BMI, HOMA index and physical activity; moreover, to compare it to other studies; 2-to compare the prevalence of elevated blood pressure (BP, high triglycerides and plasma glucose levels, low HDL cholesterol and high waist circumference among individuals with MS also according to gender; 3-to determine the number of risk factors in subjects with MS and prevalence of complications in individuals with and without MS aged over 40 years. METHODS: A cross-sectional study of 1369 Individuals, 667 males (48.7% and 702 females (51.3% was considered to evaluate the prevalence of MS and associated factors in the population. RESULTS: The study showed that 22.7% (95% CI: 19.4% to 26.0% of the population has MS, which increases with age, higher BMI and sedentary lifestyle. There was no significant difference between genders until age ≥70 years and social classes. Higher prevalence of MS was observed in lower educational levels and higher prevalence of HOMA positive among individuals with MS. The most prevalent risk factors were elevated blood pressure (85%, low HDL cholesterol (83.1% and increased waist circumference (82.5%. The prevalence of elevated BP, low HDL cholesterol and plasma glucose levels did not show significant difference between genders. Individuals with MS had higher risk of cardiovascular complications over 40 years. CONCLUSION: The prevalence of MS found is similar to that in developed countries, being influenced by age, body mass index, educational levels, physical activity, and leading to a higher prevalence of cardiovascular complications after the 4th decade of life.

  13. Explosive limits and its container factors of polybasic explosive mixture gas containing H2, CH4 and CO

    Institute of Scientific and Technical Information of China (English)

    胡耀元; 李勇; 朱凯汉; 周邦智; 杨元法

    2002-01-01

    Explosive characteristics of polybasic explosive mixture gas are systematically researched. Over 28000 experimental data have been obtained from 1278 effective experiments. The paper probes into the concentration explosive limits and the container factors of polybasic explosive mixture gas which contains H2, CH4 and CO. It has worked out the sufficient and necessary condition for branch-chain explosion and the unified expression of the probability of the heterogeneous chain termination. Experiments indicate that the concentration explosive limits of polybasic explosive mixture gas (H2, CH4, CO) relate to many factors. They enlarge with the augmentability of the container (linear size, geometric shape, and flame spread direction). This will be of great significance to guiding the revision of related industrial safety targets, reclaiming and reusing related industrial tail gas and waste gas, taking precautions against the explosion hazard of mixture gas in correlated industry and mines, and applying the br

  14. Sharp genetic breaks among populations of Haptosquilla pulchella (Stomatopoda) indicate limits to larval transport: patterns, causes, and consequences.

    Science.gov (United States)

    Barber, P H; Palumbi, S R; Erdmann, M V; Moosa, M K

    2002-04-01

    To help stem the precipitous decline of coral reef ecosystems world-wide, conservation efforts are focused on establishing interconnected reserve networks to protect threatened populations. Because many coral reef organisms have a planktonic or pelagic larval dispersal phase, it is critical to understand the patterns of ecological connectivity between reserve populations that result from larval dispersal. We used genetics to infer dispersal patterns among 24 Indo-West Pacific populations of the mantis shrimp, Haptosquilla pulchella. Contrary to predictions of high dispersal facilitated by the strong currents of the Indonesian throughflow, mitochondrial DNA sequences from 393 individuals displayed striking patterns of regional genetic differentiation concordant with ocean basins isolated during periods of lowered sea level. Patterns of genetic structuring indicate that although dispersal within geographical regions with semicontiguous coastlines spanning thousands of kilometres may be common, ecologically meaningful connections can be rare among populations separated by as little as 300 km of open ocean. Strong genetic mosaics in a species with high dispersal potential highlight the utility of genetics for identifying regional patterns of genetic connectivity between marine populations and show that the assumption that ocean currents will provide ecological connectivity among marine populations must be empirically tested in the design of marine reserve networks.

  15. Body Image and Body Change: Predictive Factors in an Iranian Population

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    Garrusi, Behshid; Garousi, Saeide; Baneshi, Mohammad R.

    2013-01-01

    Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery) and their risk factors such as demographic variables, Body Mass Index (BMI), Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. Results: About 54.3% of respondents were females. The mean (SD) of age was 31.06 (10.24) years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Conclusions: Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted. PMID:24049621

  16. Body image and body change: Predictive factors in an Iranian population

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    Behshid Garrusi

    2013-01-01

    Full Text Available Background: Body concerns and its health consequences such as eating disorders and harmful body change activities are mentioned in Asian countries. This study evaluates factors contributing to body image/shape changes in an Iranian population. Methods: In this cross-sectional study we focused on four main body change activity (diet, exercise, substance use, and surgery and their risk factors such as demographic variables, Body Mass Index (BMI, Media, Body-Esteem, Perceived Socio-cultural Pressure, Body dissatisfaction and, Self-Esteem. Approximately, 1,200 individuals between 14-55 years old participated in this study. We used a multistage sampling method. In each region, the first household was selected at random. The probability of outcomes was estimated from logistic models. Results: About 54.3% of respondents were females. The mean (SD of age was 31.06 (10.24 years. Variables such as gender, age, BMI, use of media and socio cultural factors as, body dissatisfaction, body-esteem and pressure by relatives were the main factors that influenced body change methods. In particular we have seen that male are 53% less likely to follow surgical treatments, but 125% were more likely to use substances. Conclusions: Investigation of body concern and its health related problem should be assessed in cultural context. For effectiveness of interventional programs and reducing harmful body image/shape changes activities, socio-cultural background should be noted.

  17. Prevalence of maternal group B streptococcal colonization and related risk factors in a Brazilian population

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    Alexander S. Zusman

    2006-08-01

    Full Text Available The objective of this study was to determine the prevalence of maternal group B Streptococcal (GBS colonization and compare risk factor data related to GBS colonization. A prospective surveillance study of 598 pregnant women was conducted in two socioeconomically diverse maternity hospitals in Ribeirão Preto, Brazil between June and October 1999. Swabs from the lower vagina were obtained between 35 and 37 weeks gestation and cultured on selective media. Risk factor data were obtained by patient interview and chart review. The overall maternal GBS colonization prevalence rate was 17.9%. There was no association of GBS colonization with maternity hospital and no association of GBS colonization with previously identified risk factors, such as age, race, martial status, maternal education, parity, smoking, or alcohol use. There is a relatively high prevalence of maternal GBS colonization in this Brazilian population, although previously-identified-risk factors were not found to be important. This study provides baseline data for the creation of community-based GBS disease prevention protocols.

  18. The evaluation of disability and its related factors among the elderly population in Kashan, Iran

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    Aghahoseini Shima

    2007-09-01

    Full Text Available Abstract Background Recent literature indicates that developing countries in Asia are aging faster than other countries in the world and disability has become one of the greater public health concern in these countries. Pausity of published data on the elderly disability in Iran signifies the importance of this study designed to evaluate the disability and its related factors among the elderly population in Kashan, Iran during 2006–2007. Methods/Design A cross-sectional study is conducting on a multy-stage random sample of elderly people in Kashan ages 65 years and older. Volunteer participants were included by age 65 and older and excluded if they had the medical diagnosis of Alzhimer disease. The WHO DAS II was used as the generic disability measure in this survey. The original version of WHO DAS II was translated into Farsi according to the standardized guidelines for cross-cultural adaptation of health-related measures. Upon completion of data collection the descriptive statistics will compute all the variables. Chi-square, t-test analysis and ANOVA will be used to examine significant differences between the subgroups. Discussion This is the first research protocol to study disability among the Iranian elderly population. Presently, 80% of eligible subjects have been selected. The results of this study will help to develop more effective protocols to assist Iranian elderly population with disabilities.

  19. Illiteracy, Financial Insecurity and Loneliness as Key Factors for Depression in Elderly Population of Punjab

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    R. Ka