Post, Eric; Forchhammer, Mads C
2004-06-22
According to ecological theory, populations whose dynamics are entrained by environmental correlation face increased extinction risk as environmental conditions become more synchronized spatially. This prediction is highly relevant to the study of ecological consequences of climate change. Recent empirical studies have indicated, for example, that large-scale climate synchronizes trophic interactions and population dynamics over broad spatial scales in freshwater and terrestrial systems. Here, we present an analysis of century-scale, spatially replicated data on local weather and the population dynamics of caribou in Greenland. Our results indicate that spatial autocorrelation in local weather has increased with large-scale climatic warming. This increase in spatial synchrony of environmental conditions has been matched, in turn, by an increase in the spatial synchrony of local caribou populations toward the end of the 20th century. Our results indicate that spatial synchrony in environmental conditions and the populations influenced by them are highly variable through time and can increase with climatic warming. We suggest that if future warming can increase population synchrony, it may also increase extinction risk.
Persson, Lennart; Elliott, J Malcolm
2013-05-01
The theory of cannibal dynamics predicts a link between population dynamics and individual life history. In particular, increased individual growth has, in both modeling and empirical studies, been shown to result from a destabilization of population dynamics. We used data from a long-term study of the dynamics of two leech (Erpobdella octoculata) populations to test the hypothesis that maximum size should be higher in a cycling population; one of the study populations exhibited a delayed feedback cycle while the other population showed no sign of cyclicity. A hump-shaped relationship between individual mass of 1-year-old leeches and offspring density the previous year was present in both populations. As predicted from the theory, the maximum mass of individuals was much larger in the fluctuating population. In contrast to predictions, the higher growth rate was not related to energy extraction from cannibalism. Instead, the higher individual mass is suggested to be due to increased availability of resources due to a niche widening with increased individual body mass. The larger individual mass in the fluctuating population was related to a stronger correlation between the densities of 1-year-old individuals and 2-year-old individuals the following year in this population. Although cannibalism was the major mechanism regulating population dynamics, its importance was negligible in terms of providing cannibalizing individuals with energy subsequently increasing their fecundity. Instead, the study identifies a need for theoretical and empirical studies on the largely unstudied interplay between ontogenetic niche shifts and cannibalistic population dynamics.
Are elderly dependency ratios associated with general population suicide rates?
Shah, Ajit
2011-05-01
The elderly population size is increasing worldwide due to falling birth rates and increasing life expectancy. It has been hypothesized that as the elderly dependency ratio (the ratio of those over the age of 65 years to those under 65) increases, there will be fewer younger people available to care for older people and this, in turn, will increase the burden on younger carers with increased levels of psychiatric morbidity leading to an increase in general population suicide rates. A cross-national study examining the relationship between elderly dependency ratios and general population suicide rates was conducted using data from the World Health Organization and the United Nations websites. The main findings were of a significant and independent positive correlation between elderly dependency ratios and general population suicide rates in both genders. The contribution of cross-national differences in psychiatric morbidity in younger carers on general population suicide rates requires further study. The prevalence of psychiatric morbidity in younger carers of older people should be examined by: (i) cross-national studies using standardized measures of psychiatric morbidity that are education-free, culture-fair and language-fair; and (ii) within-country longitudinal studies with changing elderly dependency ratios over time.
Richter, Dirk; Berger, Klaus
2013-05-01
Throughout the western world, an increasing demand for psychiatric services is reported. However, a systematic review published in 2008 came to the conclusion that there is no sufficient evidence for increasing mental disorders in the recent decades. A systematic review on studies with repeating cross-sectional surveys in the general population, published since 2008, was conducted. 33 study results were included into the review. The majority of publications did not report increasing mental health problems in the general population. The increasing demand for psychiatric services is not associated with increasing mental disorders in the general population. © Georg Thieme Verlag KG Stuttgart · New York.
Temporal dynamics of genetic variability in a mountain goat (Oreamnos americanus) population.
Ortego, Joaquín; Yannic, Glenn; Shafer, Aaron B A; Mainguy, Julien; Festa-Bianchet, Marco; Coltman, David W; Côté, Steeve D
2011-04-01
The association between population dynamics and genetic variability is of fundamental importance for both evolutionary and conservation biology. We combined long-term population monitoring and molecular genetic data from 123 offspring and their parents at 28 microsatellite loci to investigate changes in genetic diversity over 14 cohorts in a small and relatively isolated population of mountain goats (Oreamnos americanus) during a period of demographic increase. Offspring heterozygosity decreased while parental genetic similarity and inbreeding coefficients (F(IS) ) increased over the study period (1995-2008). Immigrants introduced three novel alleles into the population and matings between residents and immigrants produced more heterozygous offspring than local crosses, suggesting that immigration can increase population genetic variability. The population experienced genetic drift over the study period, reflected by a reduced allelic richness over time and an 'isolation-by-time' pattern of genetic structure. The temporal decline of individual genetic diversity despite increasing population size probably resulted from a combination of genetic drift due to small effective population size, inbreeding and insufficient counterbalancing by immigration. This study highlights the importance of long-term genetic monitoring to understand how demographic processes influence temporal changes of genetic diversity in long-lived organisms. © 2011 Blackwell Publishing Ltd.
Xu, Laixiang; Xue, Huiliang; Song, Mingjing; Zhao, Qinghua; Dong, Jingping; Liu, Juan; Guo, Yu; Xu, Tongqin; Cao, Xiaoping; Wang, Fusheng; Wang, Shuqing; Hao, Shushen; Yang, Hefang; Zhang, Zhibin
2013-01-01
Genetic diversity is essential for persistence of animal populations over both the short- and long-term. Previous studies suggest that genetic diversity may decrease with population decline due to genetic drift or inbreeding of small populations. For oscillating populations, there are some studies on the relationship between population density and genetic diversity, but these studies were based on short-term observation or in low-density phases. Evidence from rapidly expanding populations is lacking. In this study, genetic diversity of a rapidly expanding population of the Greater long-tailed hamsters during 1984-1990, in the Raoyang County of the North China Plain was studied using DNA microsatellite markers. Results show that genetic diversity was positively correlated with population density (as measured by % trap success), and the increase in population density was correlated with a decrease of genetic differentiation between the sub-population A and B. The genetic diversity tended to be higher in spring than in autumn. Variation in population density and genetic diversity are consistent between sub-population A and B. Such results suggest that dispersal is density- and season-dependent in a rapidly expanding population of the Greater long-tailed hamster. For typically solitary species, increasing population density can increase intra-specific attack, which is a driving force for dispersal. This situation is counterbalanced by decreasing population density caused by genetic drift or inbreeding as the result of small population size. Season is a major factor influencing population density and genetic diversity. Meanwhile, roads, used to be considered as geographical isolation, have less effect on genetic differentiation in a rapidly expanding population. Evidences suggest that gene flow (Nm) is positively correlated with population density, and it is significant higher in spring than that in autumn.
Individual and population-level responses to ocean acidification.
Harvey, Ben P; McKeown, Niall J; Rastrick, Samuel P S; Bertolini, Camilla; Foggo, Andy; Graham, Helen; Hall-Spencer, Jason M; Milazzo, Marco; Shaw, Paul W; Small, Daniel P; Moore, Pippa J
2016-01-29
Ocean acidification is predicted to have detrimental effects on many marine organisms and ecological processes. Despite growing evidence for direct impacts on specific species, few studies have simultaneously considered the effects of ocean acidification on individuals (e.g. consequences for energy budgets and resource partitioning) and population level demographic processes. Here we show that ocean acidification increases energetic demands on gastropods resulting in altered energy allocation, i.e. reduced shell size but increased body mass. When scaled up to the population level, long-term exposure to ocean acidification altered population demography, with evidence of a reduction in the proportion of females in the population and genetic signatures of increased variance in reproductive success among individuals. Such increased variance enhances levels of short-term genetic drift which is predicted to inhibit adaptation. Our study indicates that even against a background of high gene flow, ocean acidification is driving individual- and population-level changes that will impact eco-evolutionary trajectories.
Hussin, A H
2014-12-17
From 2000 to 2010, the population in the Gulf Cooperation Council (GCC) countries underwent an increase of 53%, compared with an average global increase of 13%. The rates varied by country, ranging from 23% in Oman to 198% in Qatar. The main driving force for this sharp increase in population was the high demand for immigrant labour. The aim of this study was to adjust the population in the GCC countries in order to ensure that the comparisons of health-care key performance indicators with other countries account for the composition of the populations. The conclusion of the study was that adjusting the population in the GCC is instrumental for determining health spending and health outcomes, and that inaccurate forecasting would result in serious overestimation of the need for GCC countries to invest in the health-care sector. Policy-makers can utilize the population models in this study to accurately plan for health-care delivery.
Predicting the Future Impact of Droughts on Ungulate Populations in Arid and Semi-Arid Environments
Duncan, Clare; Chauvenet, Aliénor L. M.; McRae, Louise M.; Pettorelli, Nathalie
2012-01-01
Droughts can have a severe impact on the dynamics of animal populations, particularly in semi-arid and arid environments where herbivore populations are strongly limited by resource availability. Increased drought intensity under projected climate change scenarios can be expected to reduce the viability of such populations, yet this impact has seldom been quantified. In this study, we aim to fill this gap and assess how the predicted worsening of droughts over the 21st century is likely to impact the population dynamics of twelve ungulate species occurring in arid and semi-arid habitats. Our results provide support to the hypotheses that more sedentary, grazing and mixed feeding species will be put at high risk from future increases in drought intensity, suggesting that management intervention under these conditions should be targeted towards species possessing these traits. Predictive population models for all sedentary, grazing or mixed feeding species in our study show that their probability of extinction dramatically increases under future emissions scenarios, and that this extinction risk is greater for smaller populations than larger ones. Our study highlights the importance of quantifying the current and future impacts of increasing extreme natural events on populations and species in order to improve our ability to mitigate predicted biodiversity loss under climate change. PMID:23284700
Geographical variation in species' population responses to changes in temperature and precipitation.
Pearce-Higgins, James W; Ockendon, Nancy; Baker, David J; Carr, Jamie; White, Elizabeth C; Almond, Rosamunde E A; Amano, Tatsuya; Bertram, Esther; Bradbury, Richard B; Bradley, Cassie; Butchart, Stuart H M; Doswald, Nathalie; Foden, Wendy; Gill, David J C; Green, Rhys E; Sutherland, William J; Tanner, Edmund V J
2015-11-07
Despite increasing concerns about the vulnerability of species' populations to climate change, there has been little overall synthesis of how individual population responses to variation in climate differ between taxa, with trophic level or geographically. To address this, we extracted data from 132 long-term (greater than or equal to 20 years) studies of population responses to temperature and precipitation covering 236 animal and plant species across terrestrial and freshwater habitats. Our results identify likely geographical differences in the effects of climate change on populations and communities in line with macroecological theory. Temperature tended to have a greater overall impact on populations than precipitation, although the effects of increased precipitation varied strongly with latitude, being most positive at low latitudes. Population responses to increased temperature were generally positive, but did not vary significantly with latitude. Studies reporting significant climatic trends through time tended to show more negative effects of temperature and more positive effects of precipitation upon populations than other studies, indicating climate change has already impacted many populations. Most studies of climate change impacts on biodiversity have focused on temperature and are from middle to high northern latitudes. Our results suggest their findings may be less applicable to low latitudes. © 2015 The Author(s).
NASA Astrophysics Data System (ADS)
Cantarello, Elena; Steck, Claude E.; Fontana, Paolo; Fontaneto, Diego; Marini, Lorenzo; Pautasso, Marco
2010-03-01
Recent large-scale studies have shown that biodiversity-rich regions also tend to be densely populated areas. The most obvious explanation is that biodiversity and human beings tend to match the distribution of energy availability, environmental stability and/or habitat heterogeneity. However, the species-people correlation can also be an artefact, as more populated regions could show more species because of a more thorough sampling. Few studies have tested this sampling bias hypothesis. Using a newly collated dataset, we studied whether Orthoptera species richness is related to human population size in Italy’s regions (average area 15,000 km2) and provinces (2,900 km2). As expected, the observed number of species increases significantly with increasing human population size for both grain sizes, although the proportion of variance explained is minimal at the provincial level. However, variations in observed Orthoptera species richness are primarily associated with the available number of records, which is in turn well correlated with human population size (at least at the regional level). Estimated Orthoptera species richness (Chao2 and Jackknife) also increases with human population size both for regions and provinces. Both for regions and provinces, this increase is not significant when controlling for variation in area and number of records. Our study confirms the hypothesis that broad-scale human population-biodiversity correlations can in some cases be artefactual. More systematic sampling of less studied taxa such as invertebrates is necessary to ascertain whether biogeographical patterns persist when sampling effort is kept constant or included in models.
Increase of Elderly Population in the Rainstorm Hazard Areas of China.
Liang, Pujun; Xu, Wei; Ma, Yunjia; Zhao, Xiujuan; Qin, Lianjie
2017-08-26
In light of global warming, increased extreme precipitation events have enlarged the population exposed to floods to some extent. Extreme precipitation risk assessments are of great significance in China and allow for the response to climate change and mitigation of risks to the population. China is one of the countries most influenced by climate change and has unique national population conditions. The influence of extreme precipitation depends on the degree of exposure and vulnerability of the population. Accurate assessments of the population exposed to rising rainstorm trends are crucial to mapping extreme precipitation risks. Studying the population exposed to rainstorm hazard areas (RSHA) at the microscale is extremely urgent, due to the local characteristics of extreme precipitation events and regional diversity of the population. The spatial distribution of population density was mapped based on the national population census data from China in 1990, 2000 and 2010. RSHA were also identified using precipitation data from 1975-2015 in China, and the rainstorm tendency values were mapped using GIS in this paper. The spatial characteristics of the rainstorm tendencies were then analyzed. Finally, changes in the population in the RSHA are discussed. The results show that the extreme precipitation trends are increasing in southeastern China. From 1990 to 2010, the population in RSHA increased by 110 million, at a rate of 14.6%. The elderly in the region increased by 38 million at a rate of 86.4%. Studying the size of the population exposed to rainstorm hazards at the county scale can provide scientific evidence for developing disaster prevention and mitigation strategies from the bottom up.
ERIC Educational Resources Information Center
ALLEN, HARRY; AND OTHERS
THREE MAJOR TRENDS WILL SIGNIFICANTLY AFFECT ELEMENTARY, SECONDARY, AND HIGHER EDUCATION ENROLLMENTS THROUGHOUT THE STATE--THE INCREASING TOTAL POPULATION, THE POPULATION DISTRIBUTION BY AGE, AND THE GEOGRAPHIC RELOCATION OF THE POPULATION. THE STATE'S POPULATION WILL CONTINUE TO INCREASE, BUT AT A DECREASING RATIO. THE 0-19-YEAR-OLD POPULATION…
Effects of stand age on the demography of a temperate forest herb in post-agricultural forests.
Jacquemyn, Hans; Brys, Rein
2008-12-01
Changes in land use have been shown to have profound effects on forest plant community structure and diversity. Dispersal limitation has been invoked as a major factor hampering colonization of forest plant species, while seed-sowing experiments and performance observations have provided some evidence for recruitment limitation determining forest plant distribution in post-agricultural forests. However, most of these studies were relatively short-term, and very few studies have investigated long-term growth rates of populations occurring in recent and ancient forests. In this study, matrix models using demographic data collected for four consecutive years were used to study the effect of forest age on population dynamics of the temperate forest herb Primula elatior. A life table response experiment (LTRE) and elasticity analysis were used to analyze the effect of forest age on population growth rate (lambda) and to decompose the effect of forest age on lambda into contributions from each matrix element. Population growth increased logarithmically with increasing forest age. Bootstrap analyses showed that populations located in very recent forests (< 50-years-old) had growth rates that were significantly < 1, whereas populations located in forests > 150-years-old had growth rates that were significantly > 1. Summed elasticities for individual growth significantly decreased with increasing forest age, whereas summed elasticities for survival and fertility significantly increased with increasing forest age. The LTRE analysis showed that the increase in lambda with increasing forest age was mainly due to increased seedling and juvenile growth and increased juvenile and adult survival. Our results indicate that past agricultural land use has long-lasting effects on the demography of forest herbs and may provide an additional mechanistic explanation for the poor colonization capacity of many forest herbs in post-agricultural forests.
Le Lait, Marie-Claire; Martinez, Erin M; Severtson, Stevan G; Lavery, Sarah A; Bucher-Bartelson, Becki; Dart, Richard C
2014-12-01
Prescription opioid abuse and misuse are a serious problem in the U.S. today. Several studies have shown that the epidemic disproportionately affects rural areas. This paper uses three different rates to gain a more complete picture of opioid abuse in rural areas. This study examines prescription opioid intentional exposures using opioid classes tracked in the RADARS(®) System Poison Center Program. Intentional exposure rates were calculated adjusting for population and unique recipients of dispensed drug (URDD). These rates were analyzed using time (quarter) and the proportion of a three-digit zip code residing in a rural area as covariates. Additionally, the URDD per population rate was calculated to examine the proportion of the population filling prescriptions for opioids. After adjusting for population, intentional exposure cases significantly increased as the proportion of the population residing in a rural area increased. However, when adjusting for URDD, intentional exposure cases decreased with increasing rural population. The URDD per population increased as the proportion of people residing in a rural area increased. Using both population and URDD adjusted intentional exposure rates gives a more complete picture of opioid abuse in rural areas. Considering product availability can be used to develop opioid abuse prevention strategies and further the education of physicians serving rural areas about this epidemic. Copyright © 2014 John Wiley & Sons, Ltd.
Shukla, J B; Goyal, Ashish; Singh, Shikha; Chandra, Peeyush
2014-06-01
In this paper, a non-linear model is proposed and analyzed to study the effects of habitat characteristics favoring logistically growing carrier population leading to increased spread of typhoid fever. It is assumed that the cumulative density of habitat characteristics and the density of carrier population are governed by logistic models; the growth rate of the former increases as the density of human population increases. The model is analyzed by stability theory of differential equations and computer simulation. The analysis shows that as the density of the infective carrier population increases due to habitat characteristics, the spread of typhoid fever increases in comparison with the case without such factors. Copyright © 2013 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.
Chakrabarti, Priyadarshini; Sarkar, Sagartirtha; Basu, Parthiba
2018-05-01
Pesticides have been reported to be one of the major drivers in the global pollinator losses. The large-scale decline in honey bees, an important pollinator group, has resulted in comprehensive studies on honey bee colonies. Lack of information on native wild pollinators has paved the way for this study, which highlights the underlying evolutionary changes occurring in the wild honey bee populations exposed to pesticides along an agricultural intensification landscape. The study reports an increased genetic diversity in native Apis cerana Fabricius (Hymenoptera: Apidae) populations continually exposed to pesticide stress. An increased heterozygosity, evidenced by a higher electrophoretic banding pattern, was observed in the pesticide-exposed populations for two isozymes involved with xenobiotic metabolism-esterase and glucose-6-phosphate dehydrogenase. Differential banding patterns also revealed a higher percentage of polymorphic loci, number of polymorphic bands, Nei's genetic distance, etc. observed in these populations in the Randomly Amplified Polymorphic DNA-Polymerase Chain Reaction (RAPD-PCR) experiments using three random decamer primers. Higher heterozygosity, being indicative of a more resistant population, implies population survival within the threshold pesticide stress. This study reports such changes for the first time in native wild Indian honey bee populations exposed to pesticides and has far-reaching implications on the population adaptability under pesticide stress.
Sociodemographic characteristics of mother’s population and risk of preterm birth in Chile
2013-01-01
Background Preterm birth is a global problem in Perinatal and infant Health. Currently is gaining a growing attention. Rates of preterm birth have increased in most countries, producing a dramatic impact on public health. Factors of diverse nature have been associated to these trends. In Chile, preterm birth has increased since 90. Simultaneously, the advanced demographic transition has modified the characteristics of woman population related to maternity. The principal objective of this study is to analyze some sociodemographic characteristics of the maternal population over time, and their possible association to rates of preterm birth. The second aim is to identify groups of mothers at high risk of having a preterm child. Methods This population-based study examined all liveborn singletons in Chile from 1991 to 2008; divided in three periods. Preterm birth rates were measured as % births <37 weeks of gestation. Logistic regression assessed the risk of preterm birth associated with mother’s age, parity, and marital status, expressed as crude and adjusted odds ratios. Results Over time, rates of preterm birth increased in overall population, especially during the third period (2001–2008). In the same time, characteristics of maternal population changed: significant increase of extreme reproductive ages, significant decrease in parity and increase in mothers living without a partner. Risk of preterm birth remained higher in groups of mothers: <18 and >38 years of age; without a partner; primiparas and grandmultiparas. However, global increase in preterm birth was not explained by the modification of socio demographics characteristics of maternal population. Conclusions Some socio demographic characteristics remained associated with preterm birth over time. These associations allowed identifying five groups of mothers at higher risk to have a preterm child in the population. Increase in overall preterm birth affected all women, even those considered at “low sociodemographic risk” and the contribution of more recent period (2001–2008) to this increase is greater. Then, studied factors couldn’t explain the increase in preterm birth. Further research will have to consider other factors affecting maternal population that could explain the observed trend of preterm birth. PMID:23680406
Stepanova, Maria; Clement, Stephen; Wong, Robert; Saab, Sammy; Ahmed, Aijaz
2017-01-01
IN BRIEF Chronic liver disease (CLD) and type 2 diabetes have both been linked to increased morbidity and mortality. In this study, the impact of CLD and diabetes on all-cause mortality was quantified at the population level using U.S. population data. Both type 2 diabetes and CLD were found to be independently associated with increased mortality (age-adjusted hazard ratio [aHR] 1.98 and 1.37 for diabetes and CLD, respectively), and having both diabetes and CLD substantially increased the risk of mortality (aHR 2.41). PMID:28442821
Family welfare and health practices increase after exposure to population education.
1994-01-01
Since 1987, the State Resource Center of Jamia Millia Islamia of New Delhi has been implementing a program which integrates population education contents into its literacy education classes for adult learners. Using the core messages on family size, spacing of children, responsible parenthood, right age of marriage, population-related beliefs and customs and population and development, the Center undertook many activities such as: i) integrating population contents in literacy primers, readers and supplementary reading books; ii) development of teaching aids and instructor's resource materials; iii) organization of training for instructors and iv) holding outreach activities such as street corner plays, fairs, etc. To evaluate the impact of the program, the Center undertook an impact survey to measure the level of knowledge, attitude and practices of randomly selected beneficiaries of the project, i.e. 934 learners from 85 literacy learning centers, 5 years after the introduction of the population education program. The study used pre-test and post-test method for collecting data and to compare results. In terms of practice, the study has shown that the respondents having knowledge about family planning methods increased from 67 to 87%, after being exposed to the project's activities. There was also an increase of 61% in cases adopting family planning methods over the pre-measurement level. More importantly, there was not only an increase in awareness of public health and family welfare services but a 137% increase was registered in the use of public health and family welfare facilities for family planning counseling and services. With regard to knowledge and attitude on the various population education messages promoted by the project, the study has shown a 40% increase in "high" knowledge category and 25% increase in favorable attitude after the exposure to the project. full text
[The relationships between population and economy, and between population and education].
Yu, W
1981-01-01
The relationship between population and economy is regarded seriously by China and other countries. This problem can be analyzed and studied under 2 aspects: 1) the influence of economic development on changes in population, and 2) the influence of population increases on economic development. Under the 1st aspect, improved living conditions, hygiene, and health care generally result in lowered mortality rates. Improved economic conditions in China also increased the birthrate and at the same time increased birth control among the people; the increased birthrate was due to more marriages after liberation. In economically advanced countries, due to high expenses in raising children, people tend to limit family sizes to 2 children/family. Under the 2nd aspect, population increases place strains on the food supply and nutritional requirements, especially when increases are too rapid. They also demand more educational resources and influence quality of education. As there are currently 210 million students in China, the quality of education suffers, particularly at the college level, since most of Chinese manpower, physical and financial resources are spent on primary and secondary education. In terms of housing, transportation, health care, and natural resources, they are all intimately related to and influenced by increases in population. Consequently, the living standard would be difficult to raise if population increases are too rapid. Since 1971, population increases have been incorporated into 5-yearly and later yearly national economic plans in China. The large Chinese population is a major obstacle in raising the Chinese economic level, hence a well-planned population control program is essential.
Potential for parasite-induced biases in aquatic invertebrate population studies
Fisher, Justin D.L.; Mushet, David M.; Stockwell, Craig A.
2014-01-01
Recent studies highlight the need to include estimates of detection/capture probability in population studies. This need is particularly important in studies where detection and/or capture probability is influenced by parasite-induced behavioral alterations. We assessed potential biases associated with sampling a population of the amphipod Gammarus lacustris in the presence of Polymorphus spp. acanthocephalan parasites shown to increase positive phototaxis in their amphipod hosts. We trapped G. lacustris at two water depths (benthic and surface) and compared number of captures and number of parasitized individuals at each depth. While we captured the greatest number of G. lacustris individuals in benthic traps, parasitized individuals were captured most often in surface traps. These results reflect the phototaxic movement of infected individuals from benthic locations to sunlit surface waters. We then explored the influence of varying infection rates on a simulated population held at a constant level of abundance. Simulations resulted in increasingly biased abundance estimates as infection rates increased. Our results highlight the need to consider parasite-induced biases when quantifying detection and/or capture probability in studies of aquatic invertebrate populations.
Hellmair, Michael; Kinziger, Andrew P
2014-01-01
Theoretical work has shown that reduced phenotypic heterogeneity leads to population instability and can increase extinction potential, yet few examples exist of natural populations that illustrate how varying levels expressed diversity may influence population persistence, particularly during periods of stochastic environmental fluctuation. In this study, we assess levels of expressed variation and genetic diversity among demographically independent populations of tidewater goby (Eucyclogobius newberryi), show that reductions in both factors typically coincide, and describe how low levels of diversity contribute to the extinction risk of these isolated populations. We illustrate that, for this annual species, continuous reproduction is a safeguard against reproductive failure by any one population segment, as natural, stochastically driven salinity increases frequently result in high mortality among juvenile individuals. Several study populations deviated from the natural pattern of year-round reproduction typical for the species, rendering those with severely truncated reproductive periods vulnerable to extinction in the event of environmental fluctuation. In contrast, demographically diverse populations are more likely to persist through such periods through the continuous presence of adults with broader physiological tolerance to abrupt salinity changes. Notably, we found a significant correlation between genetic diversity and demographic variation in the study populations, which could be the result of population stressors that restrict both of these diversity measures simultaneously, or suggestive of a causative relationship between these population characteristics. These findings demonstrate the importance of biocomplexity at the population level, and assert that the maintenance of diversity contributes to population resilience and conservation of this endangered species.
Trends in the breeding population and driving factors of Adélie penguin in the Ross Sea
NASA Astrophysics Data System (ADS)
He, H.; Li, X.; Cheng, X.
2017-12-01
Ross Sea regions have been characterized by high penguin-chick-rearing habitat suitability in the recent past. Many studies have been done to study the Adélie penguins in the Ross Sea. However, the data they used both had advantages and drawbacks. Besides, little quantitative analysis were carried out to study the impact factors on the penguin population change. In this study, penguin population data from MAPPPD (Mapping application for penguin populations and projected dynamics) and IBA (Important bird areas in Antarctica) were integrated and analyzed to study the distribution and trends in the breeding population of Adélie penguin over time in the Ross Sea. In addition, linear fitting method for spatial data in time series were used to study the driving factors such as 2m-temperature, sea ice cover and chlorophyll-a concentration which can quantify phytoplankton blooms. Results indicated that there were 45 Adélie penguin colonies in the Ross Sea. Cape Adare and Cape Crozier were two biggest colonies on which current Adélie penguin abundance were 428516 and 280787 breeding pairs, respectively. Among these colonies, penguin population on 28 colonies increased, on 5 colonies decreased and on 5 colonies remained no change over time, and there were also 5 new colonies and one colony which were extinct. It was found that Adélie penguin population in most of colonies in the Ross Sea increased, which meant that Adélie penguins in the Ross Sea were "climate change winners". The main reasons for the increase in Adélie penguin population in the Ross Sea might be the rise in 2m-temperature and the increase in sea ice cover and phytoplankton. Higher temperatures have resulted in glacial retreat and snow melting, which leads to an increase in available habitat for penguins. The increased sea ice and phytoplankton might positively affect the abundance of Antarctic krill that was the major prey item for Adélie penguins in Antarctic.
Relationships between human population density and burned area at continental and global scales.
Bistinas, Ioannis; Oom, Duarte; Sá, Ana C L; Harrison, Sandy P; Prentice, I Colin; Pereira, José M C
2013-01-01
We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over < 22% of Europe and Australia. Increasing population density is associated with both increased and decreased in fire. The nature of the relationship depends on land-use: increasing population density is associated with increased burned are in rangelands but with decreased burned area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning.
Relationships between Human Population Density and Burned Area at Continental and Global Scales
Bistinas, Ioannis; Oom, Duarte; Sá, Ana C. L.; Harrison, Sandy P.; Prentice, I. Colin; Pereira, José M. C.
2013-01-01
We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over < 22% of Europe and Australia. Increasing population density is associated with both increased and decreased in fire. The nature of the relationship depends on land-use: increasing population density is associated with increased burned are in rangelands but with decreased burned area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning. PMID:24358108
Effects of sample size on estimates of population growth rates calculated with matrix models.
Fiske, Ian J; Bruna, Emilio M; Bolker, Benjamin M
2008-08-28
Matrix models are widely used to study the dynamics and demography of populations. An important but overlooked issue is how the number of individuals sampled influences estimates of the population growth rate (lambda) calculated with matrix models. Even unbiased estimates of vital rates do not ensure unbiased estimates of lambda-Jensen's Inequality implies that even when the estimates of the vital rates are accurate, small sample sizes lead to biased estimates of lambda due to increased sampling variance. We investigated if sampling variability and the distribution of sampling effort among size classes lead to biases in estimates of lambda. Using data from a long-term field study of plant demography, we simulated the effects of sampling variance by drawing vital rates and calculating lambda for increasingly larger populations drawn from a total population of 3842 plants. We then compared these estimates of lambda with those based on the entire population and calculated the resulting bias. Finally, we conducted a review of the literature to determine the sample sizes typically used when parameterizing matrix models used to study plant demography. We found significant bias at small sample sizes when survival was low (survival = 0.5), and that sampling with a more-realistic inverse J-shaped population structure exacerbated this bias. However our simulations also demonstrate that these biases rapidly become negligible with increasing sample sizes or as survival increases. For many of the sample sizes used in demographic studies, matrix models are probably robust to the biases resulting from sampling variance of vital rates. However, this conclusion may depend on the structure of populations or the distribution of sampling effort in ways that are unexplored. We suggest more intensive sampling of populations when individual survival is low and greater sampling of stages with high elasticities.
Crawford, Brian A.; Moore, Clinton; Norton, Terry M.; Maerz, John C.
2018-01-01
A challenge for making conservation decisions is predicting how wildlife populations respond to multiple, concurrent threats and potential management strategies, usually under substantial uncertainty. Integrated modeling approaches can improve estimation of demographic rates necessary for making predictions, even for rare or cryptic species with sparse data, but their use in management applications is limited. We developed integrated models for a population of diamondback terrapins (Malaclemys terrapin) impacted by road-associated threats to (i) jointly estimate demographic rates from two mark-recapture datasets, while directly estimating road mortality and the impact of management actions deployed during the study; and (ii) project the population using population viability analysis under simulated management strategies to inform decision-making. Without management, population extirpation was nearly certain due to demographic impacts of road mortality, predators, and vegetation. Installation of novel flashing signage increased survival of terrapins that crossed roads by 30%. Signage, along with small roadside barriers installed during the study, increased population persistence probability, but the population was still predicted to decline. Management strategies that included actions targeting multiple threats and demographic rates resulted in the highest persistence probability, and roadside barriers, which increased adult survival, were predicted to increase persistence more than other actions. Our results support earlier findings showing mitigation of multiple threats is likely required to increase the viability of declining populations. Our approach illustrates how integrated models may be adapted to use limited data efficiently, represent system complexity, evaluate impacts of threats and management actions, and provide decision-relevant information for conservation of at-risk populations.
Epidemiology of suicide in Israel: a nationwide population study.
Lubin, G; Glasser, S; Boyko, V; Barell, V
2001-03-01
In Israel, some population characteristics and lifestyle patterns make epidemiological research on suicide of particular interest. The Israeli population is characterized by ethnic diversity, with a multi-religious, multi-national mosaic of Jews and Arabs. These subgroups also vary in their suicidal behavior. The aims of the present study were to examine the trends in suicide incidence rates in Israel from 1984 to 1994, to identify sub-populations at high risk for suicide and to identify suicide methods associated with increased risk. Suicide rate trends in Israel over the period from 1984 to 1994 were examined for four subgroups: Jewish men and women, and Arab men and women. Cases of undetermined external cause (UEC) of death were also considered. Mortality data were obtained from the computerized data files of the Israeli Central Bureau of Statistics, which includes cause of death and sociodemographic variables. Suicide was classified according to the ICD-9 codes. Suicide rates were higher for Jews than for Arabs, and higher for men than for women. The rates among both population and sex groups increased directly with age. A significant increase over the years studied was found for Jewish men, particularly in the 18- to 21-year-old age group. An increase in the use of firearms was noted, mainly in the groups in which total suicide rates increased. The findings of this study highlight the need for further studies to identify both sub-populations at high risk for suicide, and societal trends such as lifestyles, immigration, military service, and media exposure to violence, as first steps toward planning of intervention programs to reduce suicide rates.
Hurd, Kelle; Barnabe, Cheryl
2018-02-01
Indigenous populations of Canada, America, Australia, and New Zealand have increased rates and severity of rheumatic disease. Our objective was to summarize mortality outcomes and explore disease and social factors related to mortality. A systematic search was performed in medical (Medline, EMBASE, and CINAHL), Indigenous and conference abstract databases (to June 2015) combining search terms for Indigenous populations and rheumatic diseases. Studies were included if they reported measures of mortality (crude frequency, mortality rate, survival, and potential years of life lost (PYLL)) in Indigenous populations from the four countries. Of 5269 titles and abstracts identified, 504 underwent full-text review and 12 were included. No studies from New Zealand were found. In five Canadian studies of systemic lupus erythematosus (SLE) patients, First Nations ethnicity was associated with lower survival after adjusting for disease and social factors, and an increased frequency of death from lupus and its complications compared to Caucasians was found. All-cause mortality was higher in Native Americans (n = 2 studies) relative to Whites with SLE after adjusting for disease and social factors, but not in those with lupus nephritis alone. Australian Aborigines with SLE frequently developed infection and lupus complications leading to death (n = 3 studies). Mortality rates were increased in Pima Indians in the United States with rheumatoid arthritis (RA) compared to those without RA. One study in Native Americans with scleroderma found nearly all deaths were related to progressive disease. Canadian and American Indigenous populations with SLE have increased mortality rates compared to Caucasian populations. Mortality in Canadian and Australian Indigenous populations with SLE, and in Native American populations with RA and scleroderma, is frequently attributed to disease progression or complications. The proportional attribution of rheumatic disease severity and social factors to mortality and complications leading to death between Indigenous and non-Indigenous populations has not been fully evaluated. Copyright © 2018 Elsevier Inc. All rights reserved.
Spatial distribution of limited resources and local density regulation in juvenile Atlantic salmon.
Finstad, Anders G; Einum, Sigurd; Ugedal, Ola; Forseth, Torbjørn
2009-01-01
1. Spatial heterogeneity of resources may influence competition among individuals and thus have a fundamental role in shaping population dynamics and carrying capacity. In the present study, we identify shelter opportunities as a limiting resource for juvenile Atlantic salmon (Salmo salar L.). Experimental and field studies are combined in order to demonstrate how the spatial distribution of shelters may influence population dynamics on both within and among population scales. 2. In closed experimental streams, fish performance scaled negatively with decreasing shelter availability and increasing densities. In contrast, the fish in open stream channels dispersed according to shelter availability and performance of fish remaining in the streams did not depend on initial density or shelters. 3. The field study confirmed that spatial variation in densities of 1-year-old juveniles was governed both by initial recruit density and shelter availability. Strength of density-dependent population regulation, measured as carrying capacity, increased with decreasing number of shelters. 4. Nine rivers were surveyed for spatial variation in shelter availability and increased shelter heterogeneity tended to decrease maximum observed population size (measured using catch statistics of adult salmon as a proxy). 5. Our studies highlight the importance of small-scale within-population spatial structure in population dynamics and demonstrate that not only the absolute amount of limiting resources but also their spatial arrangement can be an important factor influencing population carrying capacity.
Does conurbation affect the risk of poor mental health? A population based record linkage study.
Maguire, A; O'Reilly, D
2015-07-01
To determine if urban residence is associated with an increased risk of anxiety/depression independent of psychosocial stressors, concentrated disadvantage or selective migration between urban and rural areas, this population wide record-linkage study utilised data on receipt of prescription medication linked to area level indicators of conurbation and disadvantage. An urban/rural gradient in anxiolytic and antidepressant use was evident that was independent of variation in population composition. This gradient was most pronounced amongst disadvantaged areas. Migration into increasingly urban areas increased the likelihood of medication. These results suggest increasing conurbation is deleterious to mental health, especially amongst residents of deprived areas. Copyright © 2015 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Healy, J.F.; Healy, B.B.; Wong, W.H.M.
The athletic activity of the adult U.S. population has increased markedly in the last 20 years. To evaluate the possible long-term effects of such activity on the cervical and lumbar spine, we studied a group of asymptomatic currently very active lifelong male athletes over age 40 (41-69 years old, av. age 53). Nineteen active, lifelong male athletes were studied with MRI and the results compared with previous imaging studies of other populations. An athletic history and a spine history were also taken. Evidence of asymptomatic degenerative spine disease was similar to that seen in published series of other populations. Degenerativemore » changes including disk protrusion and herniation, spondylosis, and spinal stenosis were present and increased in incidence with increasing patient age. In this group, all MRI findings proved to be asymptomatic and did not limit athletic activity. The incidence of lumbar degenerative changes in our study population of older male athletes was similar to those seen in other populations. 14 refs., 8 figs., 1 tab.« less
No evidence of critical slowing down in two endangered Hawaiian honeycreepers
Camp, Richard J.; Reed, J. Michael
2017-01-01
There is debate about the current population trends and predicted short-term fates of the endangered forest birds, Hawai`i Creeper (Loxops mana) and Hawai`i `Ākepa (L. coccineus). Using long-term population size estimates, some studies report forest bird populations as stable or increasing, while other studies report signs of population decline or impending extinction associated with introduced Japanese White-eye (Zosterops japonicus) increase. Reliable predictors of impending population collapse, well before the collapse begins, have been reported in simulations and microcosm experiments. In these studies, statistical indicators of critical slowing down, a phenomenon characterized by longer recovery rates after population size perturbation, are reported to be early warning signals of an impending regime shift observable prior to the tipping point. While the conservation applications of these metrics are commonly discussed, early warning signal detection methods are rarely applied to population size data from natural populations, so their efficacy and utility in species management remain unclear. We evaluated two time series of state-space abundance estimates (1987–2012) from Hakalau Forest National Wildlife Refuge, Hawai`i to test for evidence of early warning signals of impending population collapse for the Hawai`i Creeper and Hawai`i `Ākepa. We looked for signals throughout the time series, and prior to 2000, when white-eye abundance began increasing. We found no evidence for either species of increasing variance, autocorrelation, or skewness, which are commonly reported early warning signals. We calculated linear rather than ordinary skewness because the latter is biased, particularly for small sample sizes. Furthermore, we identified break-points in trends over time for both endangered species, indicating shifts in slopes away from strongly increasing trends, but they were only weakly supported by Bayesian change-point analyses (i.e., no step-wise changes in abundance). The break-point and change-point test results, in addition to the early warning signal analyses, support that the two populations do not appear to show signs of critical slowing down or decline. PMID:29131835
No evidence of critical slowing down in two endangered Hawaiian honeycreepers
Rozek, Jessica C.; Camp, Richard J.; Reed, J. Michael
2017-01-01
There is debate about the current population trends and predicted short-term fates of the endangered forest birds, Hawai`i Creeper (Loxops mana) and Hawai`i `Ākepa (L. coccineus). Using long-term population size estimates, some studies report forest bird populations as stable or increasing, while other studies report signs of population decline or impending extinction associated with introduced Japanese White-eye (Zosterops japonicus) increase. Reliable predictors of impending population collapse, well before the collapse begins, have been reported in simulations and microcosm experiments. In these studies, statistical indicators of critical slowing down, a phenomenon characterized by longer recovery rates after population size perturbation, are reported to be early warning signals of an impending regime shift observable prior to the tipping point. While the conservation applications of these metrics are commonly discussed, early warning signal detection methods are rarely applied to population size data from natural populations, so their efficacy and utility in species management remain unclear. We evaluated two time series of state-space abundance estimates (1987–2012) from Hakalau Forest National Wildlife Refuge, Hawai`i to test for evidence of early warning signals of impending population collapse for the Hawai`i Creeper and Hawai`i `Ākepa. We looked for signals throughout the time series, and prior to 2000, when white-eye abundance began increasing. We found no evidence for either species of increasing variance, autocorrelation, or skewness, which are commonly reported early warning signals. We calculated linear rather than ordinary skewness because the latter is biased, particularly for small sample sizes. Furthermore, we identified break-points in trends over time for both endangered species, indicating shifts in slopes away from strongly increasing trends, but they were only weakly supported by Bayesian change-point analyses (i.e., no step-wise changes in abundance). The break-point and change-point test results, in addition to the early warning signal analyses, support that the two populations do not appear to show signs of critical slowing down or decline.
NASA Astrophysics Data System (ADS)
Boori, Mukesh Singh; Choudhary, Komal; Kupriyanov, Alexander; Kovelskiy, Viktor
2015-12-01
This study illustrates the spatio-temporal dynamics of urban growth and land use changes in Samara city, Russia from 1975 to 2015. Landsat satellite imageries of five different time periods from 1975 to 2015 were acquired and quantify the changes with the help of ArcGIS 10.1 Software. By applying classification methods to the satellite images four main types of land use were extracted: water, built-up, forest and grassland. Then, the area coverage for all the land use types at different points in time were measured and coupled with population data. The results demonstrate that, over the entire study period, population was increased from 1146 thousand people to 1244 thousand from 1975 to 1990 but later on first reduce and then increase again, now 1173 thousand population. Built-up area is also change according to population. The present study revealed an increase in built-up by 37.01% from 1975 to 1995, than reduce -88.83% till 2005 and an increase by 39.16% from 2005 to 2015, along with the increase in population, migration from rural areas owing to the economic growth and technological advantages associated with urbanization. Information on urban growth, land use and land cover change study is very useful to local government and urban planners for the betterment of future plans to sustainable development of the city.
Projection of future temperature-related mortality due to climate and demographic changes.
Lee, Jae Young; Kim, Ho
2016-09-01
Understanding the effects of global climate change from both environmental and human health perspectives has gained great importance. Particularly, studies on the direct effect of temperature increase on future mortality have been conducted. However, few of those studies considered population changes, and although the world population is rapidly aging, no previous study considered the effect of society aging. Here we present a projection of future temperature-related mortality due to both climate and demographic changes in seven major cities of South Korea, a fast aging country, until 2100; we used the HadGEM3-RA model under four Representative Concentration Pathway (RCP) scenarios (RCP 2.6, 4.5, 6.0, and 8.5) and the United Nations world population prospects under three fertility scenarios (high, medium, and low). The results showed markedly increased mortality in the elderly group, significantly increasing the overall future mortality. In 2090s, South Korea could experience a four- to six-time increase in temperature-related mortality compared to that during 1992-2010 under four different RCP scenarios and three different fertility variants, while the mortality is estimated to increase only by 0.5 to 1.5 times assuming no population aging. Therefore, not considering population aging may significantly underestimate temperature risks. Copyright © 2016 Elsevier Ltd. All rights reserved.
Otis, D.L.; White, Gary C.
2002-01-01
In 1966-1971, eastern US states with hunting seasons on mourning doves (Zenaida macroura) participated in a study designed to estimate the effects of bag limit increases on population survival rates. More than 400 000 adult and juvenile birds were banded and released during this period, and subsequent harvest and return of bands, together with total harvest estimates from mail and telephone surveys of hunters, provided the database for analysis. The original analysis used an ANOVA framework, and resulted in inferences of no effect of bag limit increase on population parameters (Hayne 1975). We used a logistic regression analysis to infer that the bag limit increase did not cause a biologically significant increase in harvest rate and thus the experiment could not provide any insight into the relationship between harvest and annual survival rates. Harvest rate estimates of breeding populations from geographical subregions were used as covariates in a Program MARK analysis and revealed an association between annual survival and harvest rates, although this relationship is potentially confounded by a latitudinal gradient in survival rates of dove populations. We discuss methodological problems encountered in the analysis of these data, and provide recommendations for future studies of the relationship between harvest and annual survival rates of mourning dove populations.
The demographic changes of menopausal and geripausal women in Korea.
Kim, Mi Young; Im, Sun-Wha; Park, Hyoung Moo
2015-02-01
Osteoporosis and resultant fracture seems to be the most common skeletal disease, affecting female exclusively. Osteoporosis increases exponentially with menopause and age. Therefore the demographic data seems to be the most important & fundamental for the study of osteoporosis epidemiology. This study was to analyzed population projection from 1960 to 2060. We evaluated the demographic change of female, postmenopausal and elderly geripausal population in South Korea using Korean statistical information service database as basic fundamental data for osteoporosis epidemiology. According to population projection, the total female population will be exceeds the total male population since 2015 and maximize up to 2030. In 2030, nearly half of female will become postmenopausal and one fourth of women elderly will be geripausal. Of total female population in 2060, the proportion of postmenopausal women will be increased up to 59.8%. According to population projection in South Korea, six of ten women in 2060 will be postmenopausal and seven of ten postmenopausal women geripausal. As expected to increase proportion of elderly women, dramatic rise of osteoporosis and osteoporotic fracture also expected. Health providers pay more attention to postmenopausal and geripausal women health care.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kostova, T; Carlsen, T
We present a study, based on simulations with SERDYCA, a spatially-explicit individual based model of rodent dynamics, on the connection between population persistence and the presence of inhomogeneities in the habitat. We are specifically interested on the effect that inhomogeneities that do not fragment the environment, have on population persistence. Our results suggest that a certain percentage of inhomogeneities can increase the average time to extinction of the population. Inhomogeneities decrease the population density and can increase the ratio of juveniles in the population thus providing a better chance for the population to restore itself after a severe period withmore » critically low population density. We call this the ''inhomogeneity localization effect''.« less
Hearing loss among older construction workers: Updated analyses.
Dement, John; Welch, Laura S; Ringen, Knut; Cranford, Kim; Quinn, Patricia
2018-04-01
A prior study of this construction worker population found significant noise-associated hearing loss. This follow-up study included a much larger study population and consideration of additional risk factors. Data included audiometry, clinical chemistry, personal history, and work history. Qualitative exposure metrics for noise and solvents were developed. Analyses compared construction workers to an internal reference group with lower exposures and an external worker population with low noise exposure. Among participants (n = 19 127) an overall prevalence of hearing loss of 58% was observed, with significantly increased prevalence across all construction trades. Construction workers had significantly increased risk of hearing loss compared to reference populations, with increasing risk by work duration. Noise exposure, solvent exposure, hypertension, and smoking were significant risk factors in multivariate models. Results support a causal relationship between construction trades work and hearing loss. Prevention should focus on reducing exposure to noise, solvents, and cigarette smoke. © 2018 Wiley Periodicals, Inc.
Complicated grief in Aboriginal populations
Spiwak, Rae; Sareen, Jitender; Elias, Brenda; Martens, Patricia; Munro, Garry; Bolton, James
2012-01-01
To date there have been no studies examining complicated grief (CG) in Aboriginal populations. Although this research gap exists, it can be hypothesized that Aboriginal populations may be at increased risk for CG, given a variety of factors, including increased rates of all-cause mortality and death by suicide. Aboriginal people also have a past history of multiple stressors resulting from the effects of colonization and forced assimilation, a significant example being residential school placement. This loss of culture and high rates of traumatic events may place Aboriginal individuals at increased risk for suicide, as well as CG resulting from traumatic loss and suicide bereavement. Studies are needed to examine CG in Aboriginal populations. These studies must include cooperation with Aboriginal communities to help identify risk factors for CG, understand the role of culture among these communities, and identify interventions to reduce poor health outcomes such as suicidal behavior. PMID:22754293
Sundquist, Kristina; Frank, Gölin; Sundquist, Jan
2004-04-01
Previous studies of differences in mental health between urban and rural populations are inconsistent. To examine whether a high level of urbanisation is associated with increased incidence rates of psychosis and depression, after adjustment for age, marital status, education and immigrant status. Follow-up study of the total Swedish population aged 25-64 years with respect to first hospital admission for psychosis or depression. Level of urbanisation was defined by population density and divided into quintiles. With increasing levels of urbanisation the incidence rates of psychosis and depression rose. In the full models, those living in the most densely populated areas (quintile 5) had 68-77% more risk of developing psychosis and 12-20% more risk of developing depression than the reference group (quintile 1). A high level of urbanisation is associated with increased risk of psychosis and depression for both women and men.
Takahashi, Yuma; Kagawa, Kotaro; Svensson, Erik I; Kawata, Masakado
2014-07-18
The effect of evolutionary changes in traits and phenotypic/genetic diversity on ecological dynamics has received much theoretical attention; however, the mechanisms and ecological consequences are usually unknown. Female-limited colour polymorphism in damselflies is a counter-adaptation to male mating harassment, and thus, is expected to alter population dynamics through relaxing sexual conflict. Here we show the side effect of the evolution of female morph diversity on population performance (for example, population productivity and sustainability) in damselflies. Our theoretical model incorporating key features of the sexual interaction predicts that the evolution of increased phenotypic diversity will reduce overall fitness costs to females from sexual conflict, which in turn will increase productivity, density and stability of a population. Field data and mesocosm experiments support these model predictions. Our study suggests that increased phenotypic diversity can enhance population performance that can potentially reduce extinction rates and thereby influence macroevolutionary processes.
The representation of vulnerable populations in quality improvement studies.
Rolnitsky, Asaph; Kirtsman, Maksim; Goldberg, Hanna R; Dunn, Michael; Bell, Chaim M
2018-05-01
A mapping review to quantify representation of vulnerable populations, who suffer from disparity and often inequitable healthcare, in quality improvement (QI) research. Studies published in 2004-2014 inclusive from Medline, Embase and Cochrane databases for English language research with the terms 'quality improvement' or 'quality control' or 'QI' and 'plan-do-study-act' or 'PDSA' in the years 2004-2014 inclusively. Published clinical research that was a QI-themed, as identified by its declared search terms, MESH terms, abstract or title. Three reviewers identified the eligible studies independently. Excluded were publications that were not trials, evaluations or analyses. Of 2039 results, 1660 were eligible for inclusion. There were 586 (33.5%) publications that targeted a specific vulnerable population: children (184, 10.54%), mental health patients (125, 7.16%), the elderly (100, 5.73%), women (57, 3.27%), the poor (30, 1.72%), rural residents (29, 1.66%), visible minorities (27, 1.55%), the terminally ill (17, 0.97%), adolescents (16, 0.92%) and prisoners (1 study). Seventy-four articles targeted two or more vulnerable populations, and 11 targeted three population categories. On average, there were 158 QI research studies published per year, increasing from 69 in 2004 to 396 in 2014 (R2 = 0.7, P < 0.001). The relative representation of vulnerable populations had a mean of 33.58% and was stable over the time period (standard deviation (SD) = 5.9%, R2 = 0.001). Seven countries contributed to over 85% of the publications targeting vulnerable populations, with the USA contributing 62% of the studies. Over 11 years, there has been a marked increase in QI publications. Roughly one-third of all published QI research is on vulnerable populations, a stable proportion over time. Nevertheless, some vulnerable populations are under-represented. Increased education, resources and attention are encouraged to improve the health of vulnerable populations through focused QI initiatives.
Comparing population structure as inferred from genealogical versus genetic information.
Colonna, Vincenza; Nutile, Teresa; Ferrucci, Ronald R; Fardella, Giulio; Aversano, Mario; Barbujani, Guido; Ciullo, Marina
2009-12-01
Algorithms for inferring population structure from genetic data (ie, population assignment methods) have shown to effectively recognize genetic clusters in human populations. However, their performance in identifying groups of genealogically related individuals, especially in scanty-differentiated populations, has not been tested empirically thus far. For this study, we had access to both genealogical and genetic data from two closely related, isolated villages in southern Italy. We found that nearly all living individuals were included in a single pedigree, with multiple inbreeding loops. Despite F(st) between villages being a low 0.008, genetic clustering analysis identified two clusters roughly corresponding to the two villages. Average kinship between individuals (estimated from genealogies) increased at increasing values of group membership (estimated from the genetic data), showing that the observed genetic clusters represent individuals who are more closely related to each other than to random members of the population. Further, average kinship within clusters and F(st) between clusters increases with increasingly stringent membership threshold requirements. We conclude that a limited number of genetic markers is sufficient to detect structuring, and that the results of genetic analyses faithfully mirror the structuring inferred from detailed analyses of population genealogies, even when F(st) values are low, as in the case of the two villages. We then estimate the impact of observed levels of population structure on association studies using simulated data.
Comparing population structure as inferred from genealogical versus genetic information
Colonna, Vincenza; Nutile, Teresa; Ferrucci, Ronald R; Fardella, Giulio; Aversano, Mario; Barbujani, Guido; Ciullo, Marina
2009-01-01
Algorithms for inferring population structure from genetic data (ie, population assignment methods) have shown to effectively recognize genetic clusters in human populations. However, their performance in identifying groups of genealogically related individuals, especially in scanty-differentiated populations, has not been tested empirically thus far. For this study, we had access to both genealogical and genetic data from two closely related, isolated villages in southern Italy. We found that nearly all living individuals were included in a single pedigree, with multiple inbreeding loops. Despite Fst between villages being a low 0.008, genetic clustering analysis identified two clusters roughly corresponding to the two villages. Average kinship between individuals (estimated from genealogies) increased at increasing values of group membership (estimated from the genetic data), showing that the observed genetic clusters represent individuals who are more closely related to each other than to random members of the population. Further, average kinship within clusters and Fst between clusters increases with increasingly stringent membership threshold requirements. We conclude that a limited number of genetic markers is sufficient to detect structuring, and that the results of genetic analyses faithfully mirror the structuring inferred from detailed analyses of population genealogies, even when Fst values are low, as in the case of the two villages. We then estimate the impact of observed levels of population structure on association studies using simulated data. PMID:19550436
Screening for increased cardiometabolic risk in primary care: a systematic review
den Engelsen, Corine; Koekkoek, Paula S; Godefrooij, Merijn B; Spigt, Mark G; Rutten, Guy E
2014-01-01
Background Many programmes to detect and prevent cardiovascular disease (CVD) have been performed, but the optimal strategy is not yet clear. Aim To present a systematic review of cardiometabolic screening programmes performed among apparently healthy people (not yet known to have CVD, diabetes, or cardiometabolic risk factors) and mixed populations (apparently healthy people and people diagnosed with risk factor or disease) to define the optimal screening strategy. Design and setting Systematic review of studies performed in primary care in Western countries. Method MEDLINE, Embase, and CINAHL databases were searched for studies screening for increased cardiometabolic risk. Exclusion criteria were studies designed to assess prevalence of risk factors without follow-up or treatment; without involving a GP; when fewer than two risk factors were considered as the primary outcome; and studies constrained to ethnic minorities. Results The search strategy yielded 11 445 hits; 26 met the inclusion criteria. Five studies (1995–2012) were conducted in apparently healthy populations: three used a stepwise method. Response rates varied from 24% to 79%. Twenty-one studies (1967–2012) were performed in mixed populations; one used a stepwise method. Response rates varied from 50% to 75%. Prevalence rates could not be compared because of heterogeneity of used thresholds and eligible populations. Observed time trends were a shift from mixed to apparently healthy populations, increasing use of risk scores, and increasing use of stepwise screening methods. Conclusion The optimal screening strategy in primary care is likely stepwise, in apparently healthy people, with the use of risk scores. Increasing public awareness and actively involving GPs might facilitate screening efficiency and uptake. PMID:25267047
Human population, grasshopper and plant species richness in European countries
NASA Astrophysics Data System (ADS)
Steck, Claude E.; Pautasso, Marco
2008-11-01
Surprisingly, several studies over large scales have reported a positive spatial correlation of people and biodiversity. This pattern has important implications for conservation and has been documented for well studied taxa such as plants, amphibians, reptiles, birds and mammals. However, it is unknown whether the pattern applies also to invertebrates other than butterflies and more work is needed to establish whether the species-people relationship is explained by both variables correlating with other environmental factors. We studied whether grasshopper species richness (Orthoptera, suborder Caelifera) is related to human population size in European countries. As expected, the number of Caelifera species increases significantly with increasing human population size. But this is not the case when controlling for country area, latitude and number of plant species. Variations in Caelifera species richness are primarily associated with variations in plant species richness. Caelifera species richness also increases with decreasing mean annual precipitation, Gross Domestic Product per capita (used as an indicator for economic development) and net fertility rate of the human population. Our analysis confirms the hypothesis that the broad-scale human population-biodiversity correlations can be explained by concurrent variations in factors other than human population size such as plant species richness, environmental productivity, or habitat heterogeneity. Nonetheless, more populated countries in Europe still have more Caelifera species than less populated countries and this poses a particular challenge for conservation.
ERIC Educational Resources Information Center
Ritter, Juliana D.; McCauley, Jenna L.; Amstadter, Ananda B.; Richardson, Lisa; Kilpatrick, Dean; Tran, Trinh L.; Trung, Lam T.; Tam, Nguyen T.; Tuan, Tran; Buoi, La Thi; Ha, Tran Thu; Thach, Tran D.; Acierno, Ron
2011-01-01
Previous research in US populations has found associations between disaster-related variables, psychological variables, and post-disaster increases in smoking and alcohol use. To date, no research has examined this association in an international population of disaster exposed individuals. Data used in this study were drawn from a larger study…
Density dependence in a recovering osprey population: demographic and behavioural processes.
Bretagnolle, V; Mougeot, F; Thibault, J-C
2008-09-01
1. Understanding how density-dependent and independent processes influence demographic parameters, and hence regulate population size, is fundamental within population ecology. We investigated density dependence in growth rate and fecundity in a recovering population of a semicolonial raptor, the osprey Pandion haliaetus [Linnaeus, 1758], using 31 years of count and demographic data in Corsica. 2. The study population increased from three pairs in 1974 to an average of 22 pairs in the late 1990s, with two distinct phases during the recovery (increase followed by stability) and contrasted trends in breeding parameters in each phase. 3. We show density dependence in population growth rate in the second phase, indicating that the stabilized population was regulated. We also show density dependence in productivity (fledging success between years and hatching success within years). 4. Using long-term data on behavioural interactions at nest sites, and on diet and fish provisioning rate, we evaluated two possible mechanisms of density dependence in productivity, food depletion and behavioural interference. 5. As density increased, both provisioning rate and the size of prey increased, contrary to predictions of a food-depletion mechanism. In the time series, a reduction in fledging success coincided with an increase in the number of non-breeders. Hatching success decreased with increasing local density and frequency of interactions with conspecifics, suggesting that behavioural interference was influencing hatching success. 6. Our study shows that, taking into account the role of non-breeders, in particular in species or populations where there are many floaters and where competition for nest sites is intense, can improve our understanding of density-dependent processes and help conservation actions.
Comparative Demography of an At-Risk African Elephant Population
Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain
2013-01-01
Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes. PMID:23341984
Comparative demography of an at-risk African elephant population.
Wittemyer, George; Daballen, David; Douglas-Hamilton, Iain
2013-01-01
Knowledge of population processes across various ecological and management settings offers important insights for species conservation and life history. In regard to its ecological role, charisma and threats from human impacts, African elephants are of high conservation concern and, as a result, are the focus of numerous studies across various contexts. Here, demographic data from an individually based study of 934 African elephants in Samburu, Kenya were summarized, providing detailed inspection of the population processes experienced by the population over a fourteen year period (including the repercussions of recent increases in illegal killing). These data were compared with those from populations inhabiting a spectrum of xeric to mesic ecosystems with variable human impacts. In relation to variability in climate and human impacts (causing up to 50% of recorded deaths among adults), annual mortality in Samburu fluctuated between 1 and 14% and, unrelatedly, natality between 2 and 14% driving annual population increases and decreases. Survivorship in Samburu was significantly lower than other populations with age-specific data even during periods of low illegal killing by humans, resulting in relatively low life expectancy of males (18.9 years) and females (21.8 years). Fecundity (primiparous age and inter-calf interval) were similar to those reported in other human impacted or recovering populations, and significantly greater than that of comparable stable populations. This suggests reproductive effort of African savanna elephants increases in relation to increased mortality (and resulting ecological ramifications) as predicted by life history theory. Further comparison across populations indicated that elongated inter-calf intervals and older ages of reproductive onset were related to age structure and density, and likely influenced by ecological conditions. This study provides detailed empirical data on elephant population dynamics strongly influenced by human impacts (laying the foundation for modeling approaches), supporting predictions of evolutionary theory regarding demographic responses to ecological processes.
Charmaraman, Linda; Woo, Meghan; Quach, Ashley; Erkut, Sumru
2014-07-01
The U.S. Census shows that the racial-ethnic makeup of over 9 million people (2.9% of the total population) who self-identified as multiracial is extremely diverse. Each multiracial subgroup has unique social and political histories that may lead to distinct societal perceptions, economic situations, and health outcomes. Despite the increasing academic and media interest in multiracial individuals, there are methodological and definitional challenges in studying the population, resulting in conflicting representations in the literature. This content and methods review of articles on multiracial populations provides a comprehensive understanding of which multiracial populations have been included in research and how they have been studied, both to recognize emerging research and to identify gaps for guiding future research on this complex but increasingly visible population. We examine 125 U.S.-based peer-reviewed journal articles published over the past 20 years (1990 to 2009) containing 133 separate studies focused on multiracial individuals, primarily from the fields of psychology, sociology, social work, education, and public health. Findings include (a) descriptive data regarding the sampling strategies, methodologies, and demographic characteristics of studies, including which multiracial subgroups are most studied, gender, age range, region of country, and socioeconomic status; (b) major thematic trends in research topics concerning multiracial populations; and (c) implications and recommendations for future studies.
Castaño-Vinyals, Gemma; Nieuwenhuijsen, Mark J; Moreno, Víctor; Carrasco, Estela; Guinó, Elisabet; Kogevinas, Manolis; Villanueva, Cristina M
2011-01-01
Low participation rates in the selection of population controls are an increasing concern for the validity of case-control studies worldwide. We conducted a pilot study to assess two approaches to recruiting population controls in a study of colorectal cancer, including a face-to-face interview and blood sample collection. In the first approach, persons identified through a population roster were invited to participate through a telephone call by an interviewer telephoning on behalf of our research center. In the second approach, individuals were identified from the lists of selected family practitioners and were telephoned on behalf of the family practitioner. When the second method was used, participation rates increased from 42% to 57% and the percentage of refusals decreased from 47% to 13%. The reasons for refusing to participate did not differ significantly between the two methods. Contact through the family practitioner yielded higher response rates in population controls in the study area. 2010 SESPAS. Published by Elsevier Espana. All rights reserved.
Utilization and costs of antipsychotic agents: a Canadian population-based study, 1996-2006.
Alessi-Severini, Silvia; Biscontri, Robert G; Collins, David M; Kozyrskyj, Anita; Sareen, Jitender; Enns, Murray W
2008-05-01
This study evaluated the prescribing patterns and costs for antipsychotic agents in the population of the Canadian province of Manitoba over the past decade. A population-based study of antipsychotic utilization and costs was conducted on data collected from the administrative databases of the Manitoba Population Health Data Repository and the Statistics Canada census between index years 1996 and 2006 (April 1, 1995, through March 31, 2006). The total annual number of antipsychotic prescriptions dispensed in Manitoba increased by 227% between 1996 and 2006, and the prevalence of antipsychotic users increased by 62% over the same time interval. The fastest-growing segment of antipsychotic users in Manitoba appears to be young males, who increased from .16% in 1996 to .88% in 2006. The highest numbers of prescriptions were reported for schizophrenia, dementia, and conduct disorder. Annual expenditures for antipsychotics increased from $1.7 million in 1996 to $22.0 million in 2006 (expenditures are in Canadian dollars). The cost of second-generation agents reached 80% of total antipsychotic expenditures in 2006; risperidone was the most prescribed agent in all age groups of patients. The per-patient annual cost of antipsychotic pharmacotherapy increased by approximately 680% between 1996 and 2006 in Manitoba. The number of antipsychotic prescriptions and the prevalence of users of antipsychotic medications increased significantly in Manitoba over the study period, despite a steady-state population of approximately 1.2 million. Incremental costs relative to the use of antipsychotic medications can be explained by the market penetration of the second-generation agents and their expanded use in the treatment of various diagnoses.
Moreno, Raul; Martin-Reyes, Roberto; Jimenez-Valero, Santiago; Sanchez-Recalde, Angel; Galeote, Guillermo; Calvo, Luis; Plaza, Ignacio; Lopez-Sendon, Jose-Luis
2011-04-01
The use of drug-eluting stents (DES) in unfavourable patients has been associated with higher rates of clinical complications and stent thrombosis, and because of that concerns about the use of DES in high-risk settings have been raised. This study sought to demonstrate that the clinical benefit of DES increases as the risk profile of the patients increases. A meta-regression analysis from 31 randomized trials that compared DES and bare-metal stents, including overall 12,035 patients, was performed. The relationship between the clinical benefit of using DES (number of patients to treat [NNT] to prevent one episode of target lesion revascularization [TLR]), and the risk profile of the population (rate of TLR in patients allocated to bare-metal stents) in each trial was evaluated. The clinical benefit of DES increased as the risk profile of each study population increased: NNT for TLR=31.1-1.2 (TLR for bare-metal stents); p<0.001. The use of DES was safe regardless of the risk profile of each study population, since the effect of DES in mortality, myocardial infarction, and stent thrombosis, was not adversely affected by the risk profile of each study population (95% confidence interval for β value 0.09 to 0.11, -0.12 to 0.19, and -0.03 to-0.15 for mortality, myocardial infarction, and stent thrombosis, respectively). The clinical benefit of DES increases as the risk profile of the patients increases, without affecting safety. Copyright © 2009 Elsevier Ireland Ltd. All rights reserved.
Gomez-Cabello, A; Pedrero-Chamizo, R; Olivares, P R; Luzardo, L; Juez-Bengoechea, A; Mata, E; Albers, U; Aznar, S; Villa, G; Espino, L; Gusi, N; Gonzalez-Gross, M; Casajus, J A; Ara, I
2011-08-01
Coupled with the growth of the older population, an increase in the prevalence of overweight and obesity in this age group has occurred in the last decades. The main aims of the present study were (i) to provide an updated prevalence of overweight and obesity in a representative sample of the Spanish elderly population; (ii) to calculate the prevalence of sarcopenic obesity (SO) and (iii) to analyse the relationships between adiposity measurements and lifestyle. A cross-sectional study was carried out in a sample of 3136 persons representative of the non-institutionalized population ≥65 years of age. Anthropometric measurements were obtained using standardized techniques and equipment. Overall, 84% of the population can be categorized as overweight and/or obese. The present study indicates that 67% of the Spanish elderly population has an increased percentage of fat mass and more than 56% suffer from central obesity. Moreover, SO is present in 15% of the Spanish elderly population. Finally, a strong relationship between both physically active and sedentary lifestyles and the level of adiposity was found. Prevalence of overweight and obesity among elderly people in Spain is very high and is still increasing. Lifestyle seems to be a determinant factor in the development of obesity among elderly people. © 2011 The Authors. obesity reviews © 2011 International Association for the Study of Obesity.
Heslehurst, Nicola; Sattar, Naveed; Rajasingam, Daghni; Wilkinson, John; Summerbell, Carolyn D; Rankin, Judith
2012-12-18
Asians are at increased risk of morbidity at a lower body mass index (BMI) than European Whites, particularly relating to metabolic risk. UK maternal obesity guidelines use general population BMI criteria to define obesity, which do not represent the risk of morbidity among Asian populations. This study compares incidence of first trimester obesity using Asian-specific and general population BMI criteria. A retrospective epidemiological study of 502,474 births between 1995 and 2007, from 34 maternity units across England. Data analyses included a comparison of trends over time between ethnic groups using Asian-specific and general population BMI criteria. Logistic regression estimated odds ratios for first trimester obesity among ethnic groups following adjustment for population demographics. Black and South Asian women have a higher incidence of first trimester obesity compared with White women. This is most pronounced for Pakistani women following adjustment for population structure (OR 2.19, 95% C.I. 2.08, 2.31). There is a twofold increase in the proportion of South Asian women classified as obese when using the Asian-specific BMI criteria rather than general population BMI criteria. The incidence of obesity among Black women is increasing at the most rapid rate over time (p=0.01). The twofold increase in maternal obesity among South Asians when using Asian-specific BMI criteria highlights inequalities among pregnant women. A large proportion of South Asian women are potentially being wrongly assigned to low risk care using current UK guidelines to classify obesity and determine care requirements. Further research is required to identify if there is any improvement in pregnancy outcomes if Asian-specific BMI criteria are utilised in the clinical management of maternal obesity to ensure the best quality of care is provided for women irrespective of ethnicity.
2010-01-01
Background Prevalence of asthma and allergies in top athletes is high. However, most previous studies did not include a general population comparison group. We aimed to compare the prevalence of asthma, allergies and medical treatment in different groups of German top athletes to the general population. Methods Prior to the 2008 Summer Olympic Games, 291 German candidates for participation (65%) completed a questionnaire on respiratory and allergic symptoms. Results were compared to those of a general population study in Germany (n = 2425, response 68%). Furthermore, associations between types of sports and the self-reported outcomes were calculated. All models were adjusted for age, sex, level of education and smoking. Results Athletes reported significantly more doctors' diagnosed asthma (17% vs. 7%), more current use of asthma medication (10% vs. 4%) and allergic rhinitis (25% vs. 17%) compared to the general population. After adjustment, top athletes only had an increased Odds Ratio for doctor's diagnosed asthma (OR: 1.6; 95% CI 1.1-2.5). Compared to the general population, athletes in endurance sports had an increased OR for doctor's diagnosed asthma (2.4; 1.5-3.8) and current use of asthma medication (1.8; 1.0-3.4). In this group, current wheeze was increased when use of asthma medication was taken into account (1.8; 1.1-2.8). For other groups of athletes, no significantly increased ORs were observed. Conclusions Compared to the general population, an increased risk of asthma diagnosis and treatment was shown for athletes involved in endurance sports. This might be due to a better medical surveillance and treatment of these athletes. PMID:21118543
Changes in diffusion path length with old age in diffuse optical tomography
NASA Astrophysics Data System (ADS)
Bonnéry, Clément; Leclerc, Paul-Olivier; Desjardins, Michèle; Hoge, Rick; Bherer, Louis; Pouliot, Philippe; Lesage, Frédéric
2012-05-01
Diffuse, optical near infrared imaging is increasingly being used in various neurocognitive contexts where changes in optical signals are interpreted through activation maps. Statistical population comparison of different age or clinical groups rely on the relative homogeneous distribution of measurements across subjects in order to infer changes in brain function. In the context of an increasing use of diffuse optical imaging with older adult populations, changes in tissue properties and anatomy with age adds additional confounds. Few studies investigated these changes with age. Duncan et al. measured the so-called diffusion path length factor (DPF) in a large population but did not explore beyond the age of 51 after which physiological and anatomical changes are expected to occur [Pediatr. Res. 39(5), 889-894 (1996)]. With increasing interest in studying the geriatric population with optical imaging, we studied changes in tissue properties in young and old subjects using both magnetic resonance imaging (MRI)-guided Monte-Carlo simulations and time-domain diffuse optical imaging. Our results, measured in the frontal cortex, show changes in DPF that are smaller than previously measured by Duncan et al. in a younger population. The origin of these changes are studied using simulations and experimental measures.
Temperature-driven regime shifts in the dynamics of size-structured populations.
Ohlberger, Jan; Edeline, Eric; Vøllestad, Leif Asbjørn; Stenseth, Nils C; Claessen, David
2011-02-01
Global warming impacts virtually all biota and ecosystems. Many of these impacts are mediated through direct effects of temperature on individual vital rates. Yet how this translates from the individual to the population level is still poorly understood, hampering the assessment of global warming impacts on population structure and dynamics. Here, we study the effects of temperature on intraspecific competition and cannibalism and the population dynamical consequences in a size-structured fish population. We use a physiologically structured consumer-resource model in which we explicitly model the temperature dependencies of the consumer vital rates and the resource population growth rate. Our model predicts that increased temperature decreases resource density despite higher resource growth rates, reflecting stronger intraspecific competition among consumers. At a critical temperature, the consumer population dynamics destabilize and shift from a stable equilibrium to competition-driven generation cycles that are dominated by recruits. As a consequence, maximum age decreases and the proportion of younger and smaller-sized fish increases. These model predictions support the hypothesis of decreasing mean body sizes due to increased temperatures. We conclude that in size-structured fish populations, global warming may increase competition, favor smaller size classes, and induce regime shifts that destabilize population and community dynamics.
Adaptations of an RNA virus to increasing thermal stress
Singhal, Sonia; Leon Guerrero, Cierra M.; Whang, Stella G.; McClure, Erin M.; Busch, Hannah G.; Kerr, Benjamin
2017-01-01
Environments can change in incremental fashions, where a shift from one state to another occurs over multiple organismal generations. The rate of the environmental change is expected to influence how and how well populations adapt to the final environmental state. We used a model system, the lytic RNA bacteriophage Φ6, to investigate this question empirically. We evolved viruses for thermostability by exposing them to heat shocks that increased to a maximum temperature at different rates. We observed increases in the ability of many heat-shocked populations to survive high temperature heat shocks. On their first exposure to the highest temperature, populations that experienced a gradual increase in temperature had higher average survival than populations that experienced a rapid temperature increase. However, at the end of the experiment, neither the survival of populations at the highest temperature nor the number of mutations per population varied significantly according to the rate of thermal change. We also evaluated mutations from the endpoint populations for their effects on viral thermostability and growth. As expected, some mutations did increase viral thermostability. However, other mutations decreased thermostability but increased growth rate, suggesting that benefits of an increased replication rate may have sometimes outweighed the benefits of enhanced thermostability. Our study highlights the importance of considering the effects of multiple selective pressures, even in environments where a single factor changes. PMID:29267297
Herbinger, Karl-Heinz; Cerutti Junior, Crispim; Malta Romano, Camila; de Souza Areias Cabidelle, Aline; Fröschl, Günter
2017-01-01
Dengue occurrence is partially influenced by the immune status of the population. Consequently, the introduction of a new Dengue virus serotype can trigger explosive epidemics in susceptible populations. The determination of clusters in this scenario can help to identify hotspots and understand the disease dispersion regardless of the influence of the population herd immunity. The present study evaluated the pattern and factors associated with dengue dispersion during the first epidemic related to Dengue virus serotype 4 in Vitória, Espírito Santo state, Brazil. Data on 18,861 dengue cases reported in Vitória from September 2012 to June 2013 were included in the study. The analysis of spatial variation in temporal trend was performed to detect clusters that were compared by their respective relative risk, house index, population density, and income in an ecological study. Overall, 11 clusters were detected. The time trend increase of dengue incidence in the overall study population was 636%. The five clusters that showed a lower time trend increase than the overall population presented a higher incidence in the beginning of the epidemic and, compared to the six clusters with higher time trend increase, they presented higher relative risk for their inhabitants to acquire dengue infection (P-value = 0.02) and a lower income (P-value <0.01). House index and population density did not differ between the clusters. Early increase of dengue incidence and higher relative risk for acquiring dengue infection were favored in low-income areas. Preventive actions and improvement of infrastructure in low-income areas should be prioritized in order to diminish the magnitude of dengue dispersion after the introduction of a new serotype. PMID:28388694
DOE Office of Scientific and Technical Information (OSTI.GOV)
Newman, P.J.; Seligsohn, U.; Lyman, S.
1991-04-15
Glanzmann thrombasthenia is an autosomal recessive bleeding disorder characterized by a decrease or absence of functional platelet glycoprotein (GP) IIb-IIIa ({alpha}{sub IIb}{beta}{sub 3}) integrin receptors. Although thrombasthenia is a rare disorder, its occurrence is increased in some regions of the world where intracommunity marriage and consanguinity are commonplace, resulting in increased expression of autosomal recessive traits. The authors have been studying two populations having an unusually high frequency of Glanzmann disease, Iraqi Jews and Arabs living in Israel, and were able to distinguish the populations on the basis of immunodetectable GPIIIa and populations on the basis of immunodetectable GPIIIa andmore » platelet surface vitronectin receptor ({alpha}{sub v}{beta}{sub 3}) expression. In this article, they describe molecular genetic studies based on use of the PCR that have allowed us to characterize platelet mRNA sequences encoding GPIIb and GPIIIa from patients in these populations. These studies demonstrate the heterogeneity of Glanzmann thrombasthenia in different populations, and its homogeneity within geographically restricted populations, and offer insight into the requirements for integrin surface expression.« less
Changes in population characteristics and their implication on public health research.
Du, Ping; Coles, F Bruce; O'Campo, Patricia; McNutt, Louise-Anne
2007-07-10
Population estimates are generally drawn from one point in time to study disease trends over time; changes in population characteristics over time are usually not assessed and included in the study design. We evaluated whether population characteristics remained static and assessed the degree of population shifts over time. The analysis was based on the New York State 1990 and 2000 census data with adjustments for changes in geographic boundaries. Differences in census tract information were quantified by calculating the mean, median, standard deviation, and the percent of change for each population characteristic. Between 1990 and 2000, positive and negative fluctuations in population size created a U-shaped bimodal pattern of population change which increased the disparities in demographics and socioeconomic status for many census tracts. While 268 (10%) census tracts contracted by 10%, twice as many census tracts (21%, N = 557) grew at least 10%. Notably, the non-Hispanic African-American population grew 10% or more in 152 tracts. Although there were overall reductions in working class and undereducated populations and gains in incomes, most census tracts experienced growing income inequalities and an increased poverty rate. These changes were most pronounced in urban census tracts. Differences in population characteristics in a decade showed growing disparities in demographics and socioeconomic status. This study elucidates that important population shifts should be taken into account when conducting longitudinal research.
Changes in population characteristics and their implication on public health research
Du, Ping; Coles, F Bruce; O'Campo, Patricia; McNutt, Louise-Anne
2007-01-01
Population estimates are generally drawn from one point in time to study disease trends over time; changes in population characteristics over time are usually not assessed and included in the study design. We evaluated whether population characteristics remained static and assessed the degree of population shifts over time. The analysis was based on the New York State 1990 and 2000 census data with adjustments for changes in geographic boundaries. Differences in census tract information were quantified by calculating the mean, median, standard deviation, and the percent of change for each population characteristic. Between 1990 and 2000, positive and negative fluctuations in population size created a U-shaped bimodal pattern of population change which increased the disparities in demographics and socioeconomic status for many census tracts. While 268 (10%) census tracts contracted by 10%, twice as many census tracts (21%, N = 557) grew at least 10%. Notably, the non-Hispanic African-American population grew 10% or more in 152 tracts. Although there were overall reductions in working class and undereducated populations and gains in incomes, most census tracts experienced growing income inequalities and an increased poverty rate. These changes were most pronounced in urban census tracts. Differences in population characteristics in a decade showed growing disparities in demographics and socioeconomic status. This study elucidates that important population shifts should be taken into account when conducting longitudinal research. PMID:17623097
Govoni, Vittorio; Cesnik, Edward; Casetta, Ilaria; Tugnoli, Valeria; Tola, Maria Rosaria; Granieri, Enrico
2012-08-01
Data about the temporal trend of amyotrophic lateral sclerosis (ALS) incidence in southern Europe are scarce. Incidence studies on ALS have been carried out in the health district of Ferrara, Italy, since 1960s. We expanded the previous studies from 1964 to 2009. The study was prospective with a subsequent retrospective intensive survey of multiple sources of case ascertainment. All patients with a definite and probable ALS according to the original El Escorial criteria were selected. There were 130 incident cases in the years 1964-2009 giving an average annual crude incidence of 1.82 per 100,000 population (95% CI 1.53-2.17). An incidence increase during the study period was estimated in women (χ(2) test for trend = 7.19, p < 0.01) and in the elderly (χ(2) test for trend = 7.803, p < 0.01). The age-adjusted incidence was stable over time in both women (1.19 per 100,000, 95% CI 0.90-1.52) and men (1.45 per 100,000, 95% CI 0.12-1.84). The annual number of new ALS cases in the study population followed the Poisson distribution in both sexes as well as in the elderly group of the population. The present findings suggest that ALS incidence is nearly stable over time. The crude incidence increase we estimated over time among women is mainly explained by population ageing. The increasing incidence in the elderly population was likely the consequence of an increasing precision in ALS diagnosis in the elderly since the increasing attention and care over time of neurologic elderly patients that likely concern elderly women more than previous time periods rather than better case ascertainment of diagnosed patients. The present findings do not support the role of specific environmental factors in ALS pathogenesis.
Kwon, Hyemi; Jung, Jin Hyung; Han, Kyung Do; Park, Yong Gyu; Cho, Jung Hwan; Lee, Da Young; Han, Ji Min; Park, Se Eun; Rhee, Eun Jung; Lee, Won Young
2018-06-01
The incidence of thyroid nodules has increased worldwide in recent years. Thyroid dysfunction is a potential risk factor for hypercholesterolemia, cardiovascular disease, osteoporosis, arrhythmia, and neuropsychiatric disease. This study investigated the prevalence and annual incidence of thyroid nodules, hypothyroidism, and hyperthyroidism in Koreans. In this nationwide population-based cohort study, 51,834,660 subjects were included using the National Health Information database from 2006 to 2015, after the exclusion of subjects with thyroid cancer. The prevalence in Korea in 2015 of thyroid nodules, hypothyroidism in patients taking thyroid hormone, and hyperthyroidism in patients undergoing treatment was 15.82/1,000 population, 15.94/1,000 population, and 2.76/1,000 population, respectively. All these diseases were more prevalent among women than among men. The number of incident cases of these three thyroid diseases steadily increased from 2006 to 2012, and then decreased through 2015. The incidence of thyroid nodules, hypothyroidism treated with thyroid hormone, and treated hyperthyroidism was 6.79/1,000 population, 1.76/1,000 population, and 0.55/1,000 population, respectively, in Korea in 2015. The use of methimazole continuously increased, from 33% of total antithyroid drug prescriptions in 2006 to 74.4% in 2015, and it became the most frequently prescribed antithyroid drug in Korea. In contrast, the use of propylthiouracil continuously decreased. This was the first nationwide study of the prevalence and annual incidence of thyroid nodules, hypothyroidism, and hyperthyroidism to take into account recent changes and to include the current status of patients receiving treatment. Copyright © 2018 Korean Endocrine Society.
Standardized Thyroid Cancer Mortality in Korea between 1985 and 2010
Choi, Yun Mi; Jang, Eun Kyung; Kwon, Hyemi; Jeon, Min Ji; Kim, Won Gu; Shong, Young Kee; Kim, Won Bae
2014-01-01
Background The prevalence of thyroid cancer has increased very rapidly in Korea. However, there is no published report focusing on thyroid cancer mortality in Korea. In this study, we aimed to evaluate standardized thyroid cancer mortality using data from Statistics Korea (the Statistical Office of Korea). Methods Population and mortality data from 1985 to 2010 were obtained from Statistics Korea. Age-standardized rates of thyroid cancer mortality were calculated according to the standard population of Korea, as well as World Health Organization (WHO) standard population and International Cancer Survival Standard (ICSS) population weights. Results The crude thyroid cancer mortality rate increased from 0.1 to 0.7 per 100,000 between 1985 and 2010. The pattern was the same for both sexes. The age-standardized mortality rate (ASMR) for thyroid cancer for Korean resident registration population increased from 0.19 to 0.67 between 1985 and 2000. However, it decreased slightly, from 0.67 to 0.55, between 2000 and 2010. When mortality was adjusted using the WHO standard population and ICSS population weights, the ASMR similarly increased until 2000, and then decreased between 2000 and 2010. Conclusion Thyroid cancer mortality increased until 2000 in Korea. It started to decrease from 2000. PMID:25559576
Standardized Thyroid Cancer Mortality in Korea between 1985 and 2010.
Choi, Yun Mi; Kim, Tae Yong; Jang, Eun Kyung; Kwon, Hyemi; Jeon, Min Ji; Kim, Won Gu; Shong, Young Kee; Kim, Won Bae
2014-12-29
The prevalence of thyroid cancer has increased very rapidly in Korea. However, there is no published report focusing on thyroid cancer mortality in Korea. In this study, we aimed to evaluate standardized thyroid cancer mortality using data from Statistics Korea (the Statistical Office of Korea). Population and mortality data from 1985 to 2010 were obtained from Statistics Korea. Age-standardized rates of thyroid cancer mortality were calculated according to the standard population of Korea, as well as World Health Organization (WHO) standard population and International Cancer Survival Standard (ICSS) population weights. The crude thyroid cancer mortality rate increased from 0.1 to 0.7 per 100,000 between 1985 and 2010. The pattern was the same for both sexes. The age-standardized mortality rate (ASMR) for thyroid cancer for Korean resident registration population increased from 0.19 to 0.67 between 1985 and 2000. However, it decreased slightly, from 0.67 to 0.55, between 2000 and 2010. When mortality was adjusted using the WHO standard population and ICSS population weights, the ASMR similarly increased until 2000, and then decreased between 2000 and 2010. Thyroid cancer mortality increased until 2000 in Korea. It started to decrease from 2000.
Increased cadmium excretion in metal-adapted populations of the midge Chironomus riparius (Diptera)
DOE Office of Scientific and Technical Information (OSTI.GOV)
Postma, J.F.; Nugteren, P. van; Buckert-De Jong, M.B.
1996-03-01
Cadmium kinetics were studied in cadmium-adapted and nonadapted field populations of the midge Chironomus riparius. Accumulation and elimination experiments were carried out using first-generation laboratory-reared animals. Differences between populations were, therefore, assumed to have a genetic basis. Larvae were dissected to analyze the guts and the remainder of the larvae separately. First-order one-compartment models were not always successful in describing accumulation processes, probably due to acclimation. No interpopulation differences were observed in larval development based on dry weights, whereas some differences existed based on pupation rate. In most cases more than 80% of the total amount of cadmium was foundmore » in the guts of all populations. Larvae from cadmium-adapted populations showed a decreased net accumulation rate as well as higher equilibrium values (15--20%) compared to nonadapted populations. In addition, cadmium excretion efficiency was increased for cadmium-adapted larvae, which was due to an increased elimination rate from the guts. It was concluded that exposure to high cadmium concentrations in the field resulted in populations of C. riparius with an increased storage capability and an increased excretion efficiency, especially regarding the guts.« less
[The Marxist outlook on population].
Qin, R
1984-09-29
Marxist population theory and world population are discussed. From his study of capitalist population theory Marx concluded, "In capitalist reproduction, poverty produces population," thus rejecting Malthusian population determinism theory and developing economic determinism. According to UN statistics, world population has stabilized since the middle of this century after having doubled every hundred years for the last 300; population in the developed countries showed a positive decrease and average net population growth of the developing countries also decreased. The premise of this paper is that population grows according to social economy development. During the last several hundred years, world wealth increased much faster than population; in the last 200 years alone, the population has increased fivefold, but wealth fortyfold. In addition, world population analysis reveals an inverse relationship between wealth and population in the developed and developing countries: the poorer the country, the greater the population. From this perspective, the study of population must begin with surplus labor. Accumulation of surplus production is the foundation of continuous social development and the basis for population growth. The major difference in methods between capitalist countries and China is that the capitalist-planned fertility affects the individual family while Chinese-planned fertility has the whole nation in mind. Human fertility is determined by the economic system. Private ownership determines the private nature of fertility and public ownership determines the public nature of fertility. Thus population development is determined by the accumulation of social wealth.
Trends in incidence and resistance patterns of Staphylococcus aureus bacteremia.
Jokinen, Elina; Laine, Janne; Huttunen, Reetta; Lyytikäinen, Outi; Vuento, Risto; Vuopio, Jaana; Syrjänen, Jaana
2018-01-01
Staphylococcus aureus bacteremia (SAB) causes a significant burden on the population. Several infection control measures have been implemented in Pirkanmaa county to combat a local epidemic with methicillin-resistant Staphylococcus aureus (MRSA). We aimed to study the epidemiology of SAB and antibiotic resistance of S. aureus and the possible influence of improved infection control. Register data from 2005 to 2015 were retrospectively analysed to study the antimicrobial susceptibility, the incidence and mortality in SAB in a population-based setting. The incidence of SAB increased during the study period from 21.6 to 35.8/100,000 population. The number of both health care-associated (HA) and community-associated (CA) cases has increased. The incidence of MSSA bacteremia increased from 19.9 to 35.2/100,000 population in Pirkanmaa in parallel to other parts of Finland. The incidence of MRSA bacteremia was 10-fold (4.5/100,000 population) higher in 2011 than in other parts of the country, but sank to the national level (0.59/100,000 population) in 2015. The fatality rate decreased from 22% to 17%. The proportion of penicillin-susceptible Staphylococcus aureus (PSSA) increased from 23.9% in 2008 to 43.1% in 2015. The incidence of both HA and CA SAB has increased since 2005. Conversely, the proportion of MRSA and PRSA bacteremia has decreased. Promotion of infection control measures may have reduced the incidence of MRSA bacteremia but not the overall incidence of SAB. The rising proportion of PSSA enables the use of targeted, narrow spectrum antimicrobials.
Ricca, Mark A.; Van Vuren, Dirk H.; Weckerly, Floyd W.; Williams, Jeffrey C.; Miles, A. Keith
2014-01-01
Large mammalian herbivores introduced to islands without predators are predicted to undergo irruptive population and spatial dynamics, but only a few well-documented case studies support this paradigm. We used the Riney-Caughley model as a framework to test predictions of irruptive population growth and spatial expansion of caribou (Rangifer tarandus granti) introduced to Adak Island in the Aleutian archipelago of Alaska in 1958 and 1959. We utilized a time series of spatially explicit counts conducted on this population intermittently over a 54-year period. Population size increased from 23 released animals to approximately 2900 animals in 2012. Population dynamics were characterized by two distinct periods of irruptive growth separated by a long time period of relative stability, and the catalyst for the initial irruption was more likely related to annual variation in hunting pressure than weather conditions. An unexpected pattern resembling logistic population growth occurred between the peak of the second irruption in 2005 and the next survey conducted seven years later in 2012. Model simulations indicated that an increase in reported harvest alone could not explain the deceleration in population growth, yet high levels of unreported harvest combined with increasing density-dependent feedbacks on fecundity and survival were the most plausible explanation for the observed population trend. No studies of introduced island Rangifer have measured a time series of spatial use to the extent described in this study. Spatial use patterns during the post-calving season strongly supported Riney-Caughley model predictions, whereby high-density core areas expanded outwardly as population size increased. During the calving season, caribou displayed marked site fidelity across the full range of population densities despite availability of other suitable habitats for calving. Finally, dispersal and reproduction on neighboring Kagalaska Island represented a new dispersal front for irruptive dynamics and a new challenge for resource managers. The future demography of caribou on both islands is far from certain, yet sustained and significant hunting pressure should be a vital management tool.
Carlborg, Andreas; Ferntoft, Lena; Thuresson, Marcus; Bodegard, Johan
2015-02-01
The aim of the study was to describe temporal changes in bipolar disorder during 20 years within the Swedish population and to investigate clinical and socioeconomic characteristics, drug treatment, and mortality among patients with bipolar disorder. We conducted a retrospective, nationwide registry study (the Swedish Population Register) that included all patients diagnosed with bipolar disorder (1991-2010) and linked individual data from the Swedish National Patient Register, the National Prescribed Drug Register, and the Population Register (NCT01455961). A cross-sectional cohort analysis was performed for years 2006 versus 2009. Data were analyzed using descriptive statistics. During the study period, the annual incidence of diagnosed bipolar disorder increased 3.5-fold, and patients were diagnosed at a younger age. Mortality among patients with bipolar disorder was twice that of the general population. Compared to an age-standardized population, 30% fewer patients with bipolar disorder were available for work. Among the 40% employed, 64% reported sick leave (46% >100 days/year). Despite similar education levels, disposable income was lower compared to the general population. The most commonly preceding psychiatric diagnoses were depressive or anxiety disorders. Comparing the data for 2006 and 2009 demonstrated similar somatic comorbidity burdens and socioeconomic levels. There was also a decrease in dispensed antipsychotic medications and lithium, while antiepileptic prescriptions increased slightly. Antidepressant dispenses remained virtually unchanged. In Sweden, the incidence and prevalence of diagnosed bipolar disorder have increased during the last 20 years. Compared to the general population, these patients had similar education levels, lower employment levels, less disposable income, more sick leave, and twice the mortality. A trend towards earlier diagnosis, more use of antidepressants, and less use of lithium was seen. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Chitwood, Michael C.; Lashley, Marcus A.; Kilgo, John C.; ...
2015-02-01
Recent localized declines in white-tailed deer ( Odocoileus virginianus) populations in the southeastern United States have been linked to increasing predation pressure from coyotes ( Canis latrans), a novel predator to the region. Studies have documented coyotes as the leading cause of mortality for neonates, and 1 study documented coyotes as a mortality factor for adult females. However, no study has used field-based vital rates to conduct sensitivity analyses or model deer population trajectories under potential harvest or predator removal strategies. We used low, medium, and high values of fawn survival, adult female survival, and fecundity data collected from Fortmore » Bragg Military Installation, North Carolina to demonstrate the current declining population trajectory for deer (λ = 0.905; low λ = 0.788, high λ = 1.003). Consistent with other studies of ungulates, we determined adult female survival was the most sensitive and elastic vital rate. Further, for 3 potential management (“what if”) scenarios, we projected the population for 10 years using estimated vital rates. Reducing adult female harvest (λ = 0.935; low λ = 0.875, high λ = 1.002) and coyote removal (λ = 0.995; low λ = 0.898, high λ = 1.081) reduced the current population decline, whereas combining both approaches (λ = 1.024; low λ = 0.898, high λ = 1.141) resulted in population increases. Our data indicate that for low-density deer populations with heavy predation pressure on neonates, protecting adult females from harvest may not completely offset population declines. Coyote removal might be a necessary strategy because it could possibly increase very low fawn survival, which appears to be the most important vital rate influencing λ in our study. However, managers may have to start with reductions in adult female harvest because coyote removal would have to be continuous and consistently effective, making it an impractical management approach by itself.« less
DOE Office of Scientific and Technical Information (OSTI.GOV)
Chitwood, Michael C.; Lashley, Marcus A.; Kilgo, John C.
Recent localized declines in white-tailed deer ( Odocoileus virginianus) populations in the southeastern United States have been linked to increasing predation pressure from coyotes ( Canis latrans), a novel predator to the region. Studies have documented coyotes as the leading cause of mortality for neonates, and 1 study documented coyotes as a mortality factor for adult females. However, no study has used field-based vital rates to conduct sensitivity analyses or model deer population trajectories under potential harvest or predator removal strategies. We used low, medium, and high values of fawn survival, adult female survival, and fecundity data collected from Fortmore » Bragg Military Installation, North Carolina to demonstrate the current declining population trajectory for deer (λ = 0.905; low λ = 0.788, high λ = 1.003). Consistent with other studies of ungulates, we determined adult female survival was the most sensitive and elastic vital rate. Further, for 3 potential management (“what if”) scenarios, we projected the population for 10 years using estimated vital rates. Reducing adult female harvest (λ = 0.935; low λ = 0.875, high λ = 1.002) and coyote removal (λ = 0.995; low λ = 0.898, high λ = 1.081) reduced the current population decline, whereas combining both approaches (λ = 1.024; low λ = 0.898, high λ = 1.141) resulted in population increases. Our data indicate that for low-density deer populations with heavy predation pressure on neonates, protecting adult females from harvest may not completely offset population declines. Coyote removal might be a necessary strategy because it could possibly increase very low fawn survival, which appears to be the most important vital rate influencing λ in our study. However, managers may have to start with reductions in adult female harvest because coyote removal would have to be continuous and consistently effective, making it an impractical management approach by itself.« less
Population Growth and a Sustainable Environment.
ERIC Educational Resources Information Center
Mortimore, Michael; Tiffen, Mary
1994-01-01
Provides a history of farming practices in a densely populated area of Kenya where a recent study of the resource management practices showed positive, not negative, influences of increasing population density on both environmental conservation and productivity. (LZ)
Tourism in Austria: biodiversity, environmental sustainability, and growth issues.
Malik, Muhammad Asad Saleem; Shah, Syed Asim; Zaman, Khalid
2016-12-01
This study examined the long-run and causal relationships between international tourism, biodiversity loss, environmental sustainability, and specific growth factors under the premises of sustainable tourism in Austria, by using a consistent time series data from 1975 to 2015. The results reveal that inbound tourism, per capita income, and population density affected the potential habitat area while population density largely affected the food production in a country. Inbound tourism and population density both deteriorate the environmental quality in a form of increasing carbon dioxide (CO 2 ) emissions and fossil fuel energy consumption while per capita income reduces the fossil fuel energy consumption. Food exports increase per capita income, while food imports and population density both decrease economic growth. Inbound tourism and economic growth advance population density while forest area and food exports decrease the population density. The study supports growth-led tourism and growth-led food production in a country.
Exeter, Daniel J; Wu, Billy; Lee, Arier C; Searchfield, Grant D
2015-08-07
There is considerable evidence that New Zealand's population is ageing. For example, the median age increased from 29 years in 1951 to 37 years in 2011-12, and will likely increase to 44 years by 2061. While the implications of an ageing population have been studied, to date there is no study investigating the impacts that population ageing will have on hearing health in New Zealand. To explore the changing population structure and estimate the burden of hearing loss in New Zealand between 2011 and 2061. Using three alternative population projections from Statistics New Zealand, we quantify the likely distribution of the population between 2011 and 2061 by age and sex. Published estimates of hearing loss stratified by age and severity of hearing loss were then applied to the population projections to highlight the potential impact that population ageing will have on hearing loss in New Zealand in the next 50 years. We estimated that there were 330,269 people aged ≥14 years with hearing loss and this would increase to 449,453 in 2061. Overall, males have a higher prevalence of hearing loss than females, and while the prevalence of hearing loss among those aged 14-49 years is expected to decrease, the prevalence among the population aged ≥70 years is expected to double between 2011 and 2061. Age, sex and geographical variations in hearing loss are expected in the next 50 years. Further research into ethnic and variations in hearing loss will be instrumental in targeting the future hearing health workforce required to accommodate these increases.
The determinants of county growth.
Carlino, G A; Mills, E S
1987-02-01
The determinants of population and employment growth were explored from a broader interregional (as opposed to intraregional) perspective. Data for the 1970s, at the county level of disaggregation, were used to analyze the effects of economic, demographic, and climatic variables on population and employment growth in a simultaneous equation framework. The use of data from the more than 3000 US counties provides a considerably larger testing ground than those used in previous research. The point of departure was a conventional, general equilibrium model in which both households and producers are geographically mobile. The study's dependent variables refer to population, total, and manufacturing employment densities. Family income had a powerful effect in stimulating both population and employment density. A 10% increase in family income led to a 7.9% increase in total and a 9.2% increase in manufacturing employment densities. High family income must stand for high demand, and thus, firms are drawn to an area. High family income also drew households to an area. A 10% increase in family income led to a 5.5% increase in population density. High family income must represent "good" neighborhoods for households. High family income was positively correlated with population and employment density, but in other recent studies either a negative and significant relationship or an insignificant relationship were reported. Local taxes consist of the receipts of county government and those of municipalities, townships, school districts, and special districts within the county. The elasticities reported in Table 4 suggest that a 10% increase in such taxes resulted in about a 0.072% reduction in county population density during the decade. The Industrial Revenue Bonds (IRBs) and the percent of the labor force that is unionized are 2 potential policy instruments at the state level. The study results suggest that IRBs have not stimulated either manufacturing or total employment, and the coefficients were statistically insignificant in the structural equations. The elasticities imply that a 10% increase in percent union reduces total employment by 0.42% and manufacturing employment by 0.18%. The effect on population was tiny. Further, while not intended, the interstate highway program may have been a significant redistributor of population and employment but has not caused immigration of people and jobs from central cities.
Hubert, Jan; Pekár, Stano; Aulický, Radek; Nesvorná, Marta; Stejskal, Václav
2013-06-01
The rate of population increase of three mite species, Acarus siro (L.), Lepidoglyphus destructor (Schrank) and Tyrophagus putrescentiae (Schrank), was studied on various types of barley and at various combinations of temperature and humidity. The mites were added into the chambers and incubated for 21 days on seven different kinds of barley coming from four sites, including six cultivars and a mixture. The population increase of all species was higher on the mixture than on any other cultivar, except for Sebastian and Calgary. The increase of mites was studied at constant temperatures ranging from 5 to 35 °C and relative humidity (RH) ranging from 50 to 90 %. Positive rate of increase was found above 70 % RH for all species. The optimal humidity was at 85 % RH for A. siro and L. destructor and at 90 % RH for T. putrescentiae. As concerns the temperature, positive rate of increase was found at temperatures higher than 10, 15 and 20 °C for A. siro, L. destructor and T. putrescentiae, respectively. The temperature optima were at 23, 25, and 30 °C for A. siro, L. destructor and T. putrescentiae, respectively. Model estimated on laboratory data was then fitted to temperature and humidity records from August to November in the Czech grain store. Estimated population rate of increase was rarely positive: for A. siro it was for 24 %, for L. destructor for only 1 % and for T. putrescentiae for only 7 % days of the study period. It is concluded that in the climatic conditions of the Czech Republic the population increase of three mite pests is negligible during autumn and winter.
Moonesinghe, Ramal; Ioannidis, John P A; Flanders, W Dana; Yang, Quanhe; Truman, Benedict I; Khoury, Muin J
2012-08-01
Genome-wide association studies have identified multiple genetic susceptibility variants to several complex human diseases. However, risk-genotype frequency at loci showing robust associations might differ substantially among different populations. In this paper, we present methods to assess the contribution of genetic variants to the difference in the incidence of disease between different population groups for different scenarios. We derive expressions for the contribution of a single genetic variant, multiple genetic variants, and the contribution of the joint effect of a genetic variant and an environmental factor to the difference in the incidence of disease. The contribution of genetic variants to the difference in incidence increases with increasing difference in risk-genotype frequency, but declines with increasing difference in incidence between the two populations. The contribution of genetic variants also increases with increasing relative risk and the contribution of joint effect of genetic and environmental factors increases with increasing relative risk of the gene-environmental interaction. The contribution of genetic variants to the difference in incidence between two populations can be expressed as a function of the population attributable risks of the genetic variants in the two populations. The contribution of a group of genetic variants to the disparity in incidence of disease could change considerably by adding one more genetic variant to the group. Any estimate of genetic contribution to the disparity in incidence of disease between two populations at this stage seems to be an elusive goal.
Moonesinghe, Ramal; Ioannidis, John PA; Flanders, W Dana; Yang, Quanhe; Truman, Benedict I; Khoury, Muin J
2012-01-01
Genome-wide association studies have identified multiple genetic susceptibility variants to several complex human diseases. However, risk-genotype frequency at loci showing robust associations might differ substantially among different populations. In this paper, we present methods to assess the contribution of genetic variants to the difference in the incidence of disease between different population groups for different scenarios. We derive expressions for the contribution of a single genetic variant, multiple genetic variants, and the contribution of the joint effect of a genetic variant and an environmental factor to the difference in the incidence of disease. The contribution of genetic variants to the difference in incidence increases with increasing difference in risk-genotype frequency, but declines with increasing difference in incidence between the two populations. The contribution of genetic variants also increases with increasing relative risk and the contribution of joint effect of genetic and environmental factors increases with increasing relative risk of the gene–environmental interaction. The contribution of genetic variants to the difference in incidence between two populations can be expressed as a function of the population attributable risks of the genetic variants in the two populations. The contribution of a group of genetic variants to the disparity in incidence of disease could change considerably by adding one more genetic variant to the group. Any estimate of genetic contribution to the disparity in incidence of disease between two populations at this stage seems to be an elusive goal. PMID:22333905
Colchero, Fernando; Medellin, Rodrigo A; Clark, James S; Lee, Raymond; Katul, Gabriel G
2009-05-01
1. Our understanding of the interplay between density dependence, climatic perturbations, and conservation practices on the dynamics of small populations is still limited. This can result in uninformed strategies that put endangered populations at risk. Moreover, the data available for a large number of populations in such circumstances are sparse and mined with missing data. Under the current climate change scenarios, it is essential to develop appropriate inferential methods that can make use of such data sets. 2. We studied a population of desert bighorn sheep introduced to Tiburon Island, Mexico in 1975 and subjected to irregular extractions for the last 10 years. The unique attributes of this population are absence of predation and disease, thereby permitting us to explore the combined effect of density dependence, environmental variability and extraction in a 'controlled setting.' Using a combination of nonlinear discrete models with long-term field data, we constructed three basic Bayesian state space models with increasing density dependence (DD), and the same three models with the addition of summer drought effects. 3. We subsequently used Monte Carlo simulations to evaluate the combined effect of drought, DD, and increasing extractions on the probability of population survival under two climate change scenarios (based on the Intergovernmental Panel on Climate Change predictions): (i) increase in drought variability; and (ii) increase in mean drought severity. 4. The population grew from 16 individuals introduced in 1975 to close to 700 by 1993. Our results show that the population's growth was dominated by DD, with drought having a secondary but still relevant effect on its dynamics. 5. Our predictions suggest that under climate change scenario (i), extraction dominates the fate of the population, while for scenario (ii), an increase in mean drought affects the population's probability of survival in an equivalent magnitude as extractions. Thus, for the long-term survival of the population, our results stress that a more variable environment is less threatening than one in which the mean conditions become harsher. Current climate change scenarios and their underlying uncertainty make studies such as this one crucial for understanding the dynamics of ungulate populations and their conservation.
49 CFR 192.609 - Change in class location: Required study.
Code of Federal Regulations, 2013 CFR
2013-10-01
... in class location: Required study. Whenever an increase in population density indicates a change in... account, for the segment of pipeline involved; and (f) The actual area affected by the population density...
49 CFR 192.609 - Change in class location: Required study.
Code of Federal Regulations, 2014 CFR
2014-10-01
... in class location: Required study. Whenever an increase in population density indicates a change in... account, for the segment of pipeline involved; and (f) The actual area affected by the population density...
The Population Growth and Carrying Capacity in Semarang City
NASA Astrophysics Data System (ADS)
Hariyanto; Hadi, Sudharto P.; Buchori, Imam
2018-02-01
Population growth and development of city activities take some lands to carry them. As a result, land use competition happens among persons, society or sector. Land necessity for settlement, industry, or sector has taken over farm land, therefore farm land has been converted intensively and massively. Chronologically, population growth will cause land necessity increase. Unproductive land, especially farm land will be converted. Furthermore, farm land conversion will cause carrying capacity change. Carrying capacity has certain bio capacity. With the population growth, it will increase resource consumption; on the other side, farm land conversion will decrease carrying capacity. The objective of the study is to know about the influence of population growth towards carrying capacity (bio capacity) in Semarang city. Land consumption per capita is indeed influenced by city population, the higher the population is, the lower the land consumption per capita. With the population growth, it will influence carrying capacity. Carrying capacity here is the ratio of area to population. Analytical descriptive method is applied in the study with all sub-districts in Semarang city as the analysis unit. Population here is sub-district area and population per sub-district in Semarang city. Population growth data period is from 2000 until 2015. Main variables of the study are area per sub-district, population, population growth, carrying capacity. Result of the study shows significant influence of carrying capacity decrease, especially some outskirts in Semarang city. This condition happens because the outskirts in Semarang city tend to have dense population growth. Range of carrying capacity in Semarang city is from 0,007 to 0,117 of 0 to 1. Almost all sub-districts in Semarang city show miserable condition, except Mijen and Tugu. The conclusion of the study is that population will decrease carrying capacity. Therefore, the government should control population growth by paying attention to its distribution.
Population growth, fecundity, and survivorship in recovering populations of bighorn sheep
Singer, F.J.; Williams, E.; Miller, M.W.; Zeigenfuss, L.C.
2000-01-01
The single greatest obstacle to the restoration of large, healthy, populations of bighorn sheep (Ovis canadensis) in the western United States is epizootic outbreaks of bronchopneumonia that may kill 20–100% of the animals in populations. Although the species is capable of rapid initial growth rates following restoration into new habitat (λ = 1.23–1.30 have been observed), these rates of increase are typical only a few years following the release of a population, and then most populations either decline to extirpation or remnant status (<30 animals) or remain at <100 individuals. We studied the fecundity and survivorship of three increasing, and three declining and suspected diseased, populations of bighorn sheep (the latter were subjected to outbreaks of bronchopneumonia) located in or near several large national parks in the western United States from 1991 to 1996. Titers verified both population categories were exposed to the bacteria Pasteurella haemolytica serotypes 3; 4; and 3, 4, 10; Moraxella sp., and parainfluenza-3 and bluetongue (BT) viruses. Pregnancy rates of adult ewes were not different in increasing or decreasing populations (pooled rate = 0.93; p = 0.57), but pregnancy rates of yearlings were lower (0.00 for decreasing vs. 0.33 for increasing populations), initial production of lambs and annual recruitment of lambs was lower (0.14, decreasing vs. 0.66, p < 0.05). Adult survival was lower during the first year of an epizootic, 0.62, in one population, but recovered to 0.85 by the second and subsequent years. Survival of adult rams was variable in diseased populations; in two populations rams appeared to be disproportionately impacted, but in a third population rams survived better during the epizootic. In all the increasing park (unhunted) populations, adult ram survival (0.94 ± 0.01) was higher than adult ewe survival (0.89 ± 0.02) (p = 0.10), in contrast to published information from hunted populations where ram survival was lower. Removal of about 20% of one population for restorations severely impacted one declining population. Removals of 12–20% appeared to be excessive and were not readily compensated for in the Canyonlands National Park desert bighorn population. Disease was a significant limiting factor to restoration of bighorn sheep in the study areas; six of 11 total recovering populations we monitored closely were negatively influenced by apparent disease at some time during our observations.
Herman, R P; Provencio, K R; Torrez, R J; Seager, G M
1993-01-01
In this study we measured changes in population levels of free-living N2-fixing bacteria in the root zones of potted Bouteloua eriopoda and Sporobolus flexuosus plants as well as the photosynthetic indices of the plants in response to added nitrogen, added water, and added water plus nitrogen treatments. In addition, N2 fixer population changes in response to added carbon source and nitrogen were measured in plant-free soil columns. There were significant increases in the numbers of N2 fixers associated with both plant species in the water and the water plus nitrogen treatments. Both treatments increased the photosynthetic index, suggesting that plant exudates were driving N2 fixer population changes. Population increases were greatest in the water plus nitrogen treatments, indicating that added nitrogen was synergistic with added water and suggesting that nitrogen addition spared bacteria the metabolic cost of N2 fixation, allowing greater reproduction. Plant-free column studies demonstrated a synergistic carbon-nitrogen effect when carbon levels were limiting (low malate addition) but not when carbon was abundant (high malate), further supporting this hypothesis. The results of this study indicate the presence of N2 fixer populations which interact with plants and which may play a role in the nitrogen balance of desert grasslands. PMID:8215373
Evolution of systemic hypertension in Pakistani population.
Aziz, Kalim Uddin
2015-04-01
The prevalence of essential hypertension is alarmingly increasing in Pakistani population inspite of the demographics being of lower BMI and nutrition. In this review, the possible factors responsible for this increase are identified by reviewing the population studies conducted in Pakistan. The prevalence rate is about 3 - 4% in childhood and steeply rises near the middle age. The factors peculiar to Pakistan were increased genetic susceptibility, environmental factors such as gender, females gender, urbanization, obesity and sedentary life styles particularly in middle age, cultural practices promoting sedentary life style in female.
NASA Astrophysics Data System (ADS)
Zhou, Ting; Jia, Xiaorong; Liao, Huixuan; Peng, Shijia; Peng, Shaolin
2016-12-01
Conventional models for predicting species distribution under global warming scenarios often treat one species as a homogeneous whole. In the present study, we selected Cunninghamia lanceolata (C. lanceolata), a widely distributed species in China, to investigate the physio-ecological responses of five populations under different temperature regimes. The results demonstrate that increased mean temperatures induce increased growth performance among northern populations, which exhibited the greatest germination capacity and largest increase in the overlap between the growth curve and the monthly average temperature. However,tolerance of the southern population to extremely high temperatures was stronger than among the population from the northern region,shown by the best growth and the most stable photosynthetic system of the southern population under extremely high temperature. This result indicates that the growth advantage among northern populations due to increased mean temperatures may be weakened by lower tolerance to extremely high temperatures. This finding is antithetical to the predicted results. The theoretical coupling model constructed here illustrates that the difference in growth between populations at high and low latitudes and altitudes under global warming will decrease because of the frequent occurrence of extremely high temperatures.
NASA Astrophysics Data System (ADS)
Hogg, R. S.; Takaro, T.; Miller, C.; Hogg, E.; Anema, A.; Gislason, M.; Parkes, M.
2015-12-01
Background: Ecological footprints assess the land and water a population needs to procure its resources and handle its waste. Measures derived from these footprints look at a population's ecological overshoot rather than weighting the population to its footprint. The aim of this study was to examine the latter approach by determining what the current and future weighted world population, by income gradient, would be if everyone lived within the boundary of 1.8 hectares per person. Methods: Country-specific ecological footprints and populations for 2007 were obtained from the Global Footprint Network (www.footprintnetwork.org); and projected populations were collected from US Census Bureau (www.census.gov). Footprint growth to 2050 was based on a business as usual approach developed by Kitzes et al. in Phil. Trans. R. Soc. B (2008). Weighted population estimates were derived by multiplying actual population by the ratio of the country's footprint to overall boundary of 1.8 hectares per person. Results: The weighted global population increased by 2.4 billion people (37%) in 2007 based on our adjustment. High and middle-income country populations increased, by 242% and 10%, respectively, while low-income country populations decreased by 33%. The weighed global population in 2050 increased by 10.1 billion with the majority of this growth occurring in high-income countries -- 437% versus 67% and 9% respectively for medium and low-income countries. Conclusions: Our study showed that current and future global weighted demographic and ecological impact would be felt mainly in high-income countries even though actual population growth would occur mainly in low and middle-income countries.
Virulence of Meloidogyne spp. and Induced Resistance in Grape Rootstocks.
McKenry, Michael V; Anwar, Safdar A
2007-03-01
Harmony grape rootstock displays resistance to several Meloidogyne spp. but that resistance is not durable in commercial vineyard settings. A 2-year experiment in a microplot setting revealed host specificities of two virulent populations of Meloidogyne arenaria and an avirulent population of Meloidogyne incognita. In a subsequent split-root experiment, the avirulent nematode population was demonstrated to induce resistance to the virulent nematode population. To quantify the level of resistance, reproduction of the virulent nematode population was determined 63 days after being challenged by an avirulent nematode population using a range of inoculum densities and timeframes. Induction of resistance became apparent when the virulent nematode population was inoculated 7 days after the avirulent nematode population and increased thereafter. The level of induced resistance increased with increased inoculum levels of the avirulent nematode population. Root systems of perennial crops are commonly fed upon simultaneously by multiple nematode species. These two studies indicate that field populations can become preferentially virulent upon one or multiple rootstocks and that co-inhabiting populations may induce existing resistance mechanisms. In perennial crops, it is common for numerous nematode species besides Meloidogyne spp. to be present, including some that feed without causing apparent damage.
Rajagopalan, Archana; Balaji, Nisha
2017-01-01
Since a few studies exist on the association of neck circumference (NC) and obesity with blood pressure (BP) among adolescents in India, we found it highly relevant to measure the NC and body mass index (BMI) using them as indicators of upper body subcutaneous fat and obesity and relate them to BP in a rural and urban adolescent population in North Tamil Nadu. This is a community-based cross-sectional study of descriptive design where 500 students from urban and rural areas were selected, and their BMI, NC, and BP were measured using standardized instruments. Among urban and rural population high and normal NC positively correlated with BMI, systolic BP (SBP) and diastolic BP (DBP), indicating that the data clearly reflects increase in BMI, SBP, and DBP values with increase in NC or vice versa. The correlation was statistically significant ( P < 0.001) significantly higher BMI ( P < 0.01), SBP ( P < 0.05), and NC ( P < 0.001) was observed in urban population than rural. DBP was not significantly different in rural and urban population. 95 th percentile values are significantly higher than rest in both urban and rural population. Only the 95 th percentile values correlate and reflect similar changes in BMI, SBP, and DBP. Our studies indicate a strong association of elevation in BP with high NC and increase in BMI. Overweight and obesity were positively correlated with increase in SBP and DBP.
Importance of latrine communication in European rabbits shifts along a rural-to-urban gradient.
Ziege, Madlen; Bierbach, David; Bischoff, Svenja; Brandt, Anna-Lena; Brix, Mareike; Greshake, Bastian; Merker, Stefan; Wenninger, Sandra; Wronski, Torsten; Plath, Martin
2016-06-14
Information transfer in mammalian communication networks is often based on the deposition of excreta in latrines. Depending on the intended receiver(s), latrines are either formed at territorial boundaries (between-group communication) or in core areas of home ranges (within-group communication). The relative importance of both types of marking behavior should depend, amongst other factors, on population densities and social group sizes, which tend to differ between urban and rural wildlife populations. Our study is the first to assess (direct and indirect) anthropogenic influences on mammalian latrine-based communication networks along a rural-to-urban gradient in European rabbits (Oryctolagus cuniculus) living in urban, suburban and rural areas in and around Frankfurt am Main (Germany). The proportion of latrines located in close proximity to the burrow was higher at rural study sites compared to urban and suburban ones. At rural sites, we found the largest latrines and highest latrine densities close to the burrow, suggesting that core marking prevailed. By contrast, latrine dimensions and densities increased with increasing distance from the burrow in urban and suburban populations, suggesting a higher importance of peripheral marking. Increased population densities, but smaller social group sizes in urban rabbit populations may lead to an increased importance of between-group communication and thus, favor peripheral over core marking. Our study provides novel insights into the manifold ways by which man-made habitat alterations along a rural-to-urban gradient directly and indirectly affect wildlife populations, including latrine-based communication networks.
Nugent, Shannon M; Morasco, Benjamin J; O'Neil, Maya E; Freeman, Michele; Low, Allison; Kondo, Karli; Elven, Camille; Zakher, Bernadette; Motu'apuaka, Makalapua; Paynter, Robin; Kansagara, Devan
2017-09-05
Cannabis is increasingly available for the treatment of chronic pain, yet its efficacy remains uncertain. To review the benefits of plant-based cannabis preparations for treating chronic pain in adults and the harms of cannabis use in chronic pain and general adult populations. MEDLINE, Cochrane Database of Systematic Reviews, and several other sources from database inception to March 2017. Intervention trials and observational studies, published in English, involving adults using plant-based cannabis preparations that reported pain, quality of life, or adverse effect outcomes. Two investigators independently abstracted study characteristics and assessed study quality, and the investigator group graded the overall strength of evidence using standard criteria. From 27 chronic pain trials, there is low-strength evidence that cannabis alleviates neuropathic pain but insufficient evidence in other pain populations. According to 11 systematic reviews and 32 primary studies, harms in general population studies include increased risk for motor vehicle accidents, psychotic symptoms, and short-term cognitive impairment. Although adverse pulmonary effects were not seen in younger populations, evidence on most other long-term physical harms, in heavy or long-term cannabis users, or in older populations is insufficient. Few methodologically rigorous trials; the cannabis formulations studied may not reflect commercially available products; and limited applicability to older, chronically ill populations and patients who use cannabis heavily. Limited evidence suggests that cannabis may alleviate neuropathic pain in some patients, but insufficient evidence exists for other types of chronic pain. Among general populations, limited evidence suggests that cannabis is associated with an increased risk for adverse mental health effects. U.S. Department of Veterans Affairs. (PROSPERO: CRD42016033623).
Brennan, Angela K.; Cross, Paul C.; Higgs, Megan D.; Edwards, W. Henry; Scurlock, Brandon M.; Creel, Scott
2014-01-01
Understanding how animal density is related to pathogen transmission is important to develop effective disease control strategies, but requires measuring density at a scale relevant to transmission. However, this is not straightforward or well-studied among large mammals with group sizes that range several orders of magnitude or aggregation patterns that vary across space and time. To address this issue, we examined spatial variation in elk (Cervus canadensis) aggregation patterns and brucellosis across 10 regions in the Greater Yellowstone Area where previous studies suggest the disease may be increasing. We hypothesized that rates of increasing brucellosis would be better related to the frequency of large groups than mean group size or population density, but we examined whether other measures of density would also explain rising seroprevalence. To do this, we measured wintering elk density and group size across multiple spatial and temporal scales from monthly aerial surveys. We used Bayesian hierarchical models and 20 years of serologic data to estimate rates of increase in brucellosis within the 10 regions, and to examine the linear relationships between these estimated rates of increase and multiple measures of aggregation. Brucellosis seroprevalence increased over time in eight regions (one region showed an estimated increase from 0.015 in 1991 to 0.26 in 2011), and these rates of increase were positively related to all measures of aggregation. The relationships were weaker when the analysis was restricted to areas where brucellosis was present for at least two years, potentially because aggregation was related to disease-establishment within a population. Our findings suggest that (1) group size did not explain brucellosis increases any better than population density and (2) some elk populations may have high densities with small groups or lower densities with large groups, but brucellosis is likely to increase in either scenario. In this case, any one control method such as reducing population density or group size may not be sufficient to reduce transmission. This study highlights the importance of examining the density-transmission relationship at multiple scales and across populations before broadly applying disease control strategies.
Conducting Clinical Research with Prescription Opioid Dependence: Defining the Population
Weiss, Roger D.; Potter, Jennifer S.; Copersino, Marc L.; Prather, Kristi; Jacobs, Petra; Provost, Scott; Chim, David; Selzer, Jeffrey; Ling, Walter
2010-01-01
Most treatment studies of opioid-dependent populations have focused predominantly on heroin users, despite a recent increase in those dependent upon prescription opioids. A key methodological challenge involved in studying the latter group involves defining the population. Specifically, researchers must decide whether to include 1) concurrent heroin users and 2) individuals with pain. The multi-site Prescription Opioid Addiction Treatment Study is examining treatments for this population. This paper describes various inclusion criteria considered by the study team related to heroin use and pain. The goal was to recruit a distinct but generalizable population of individuals dependent upon prescription opioids. PMID:20163386
Koh, Victor; Cheung, Carol Y; Li, Xiang; Tian, Dechao; Wang, Jie Jin; Mitchell, Paul; Cheng, Ching-Yu; Wong, Tien Y
2016-01-01
To describe the prevalence of retinal vein occlusion (RVO) and its risk factors in a multi-ethnic Asian population. This population-based study of 10,033 participants (75.7% response rate) included Chinese, Indian and Malay persons aged 40 years and older. A comprehensive ophthalmic examination, standardized interviews and laboratory blood tests were performed. Digital fundus photographs were assessed for presence of RVO following the definitions used in the Blue Mountains Eye Study. Regression analysis models were constructed to study the relationship between ocular and systemic factors and RVO. Age-specific prevalence rates of RVO were applied to project the number of people affected in Asia from 2013 to 2040. The overall crude prevalence of RVO was 0.72% (n = 71; 95% confidence interval, CI, 0.54-0.87%). The crude prevalence of RVO was similar in Chinese, Indian and Malay participants (p = 0.865). In multivariable regression models, significant risk factors of RVO included increased age (odds ratio, OR, 1.03, 95% CI 1.01-1.06), hypertension (OR 3.65, 95% CI 1.61-8.31), increased serum creatinine (OR 1.04, 95% CI 1.01-1.06, per 10 mmol/L increase), history of heart attack (OR 2.25, 95% CI 1.11-4.54) and increased total cholesterol (OR 1.31, 95% CI 1.07-1.59, per 1 mmol/L increase). None of the ocular parameters were associated with RVO. RVO is estimated to affect up to 16 and 21 million people in Asia by 2020 and 2040, respectively. RVO was detected in 0.72% of a multi-ethnic Asian population aged 40-80 years in Singapore. The significant systemic risk factors of RVO are consistent with studies in white populations.
[A comparison of convenience sampling and purposive sampling].
Suen, Lee-Jen Wu; Huang, Hui-Man; Lee, Hao-Hsien
2014-06-01
Convenience sampling and purposive sampling are two different sampling methods. This article first explains sampling terms such as target population, accessible population, simple random sampling, intended sample, actual sample, and statistical power analysis. These terms are then used to explain the difference between "convenience sampling" and purposive sampling." Convenience sampling is a non-probabilistic sampling technique applicable to qualitative or quantitative studies, although it is most frequently used in quantitative studies. In convenience samples, subjects more readily accessible to the researcher are more likely to be included. Thus, in quantitative studies, opportunity to participate is not equal for all qualified individuals in the target population and study results are not necessarily generalizable to this population. As in all quantitative studies, increasing the sample size increases the statistical power of the convenience sample. In contrast, purposive sampling is typically used in qualitative studies. Researchers who use this technique carefully select subjects based on study purpose with the expectation that each participant will provide unique and rich information of value to the study. As a result, members of the accessible population are not interchangeable and sample size is determined by data saturation not by statistical power analysis.
Water, fuel and energy issues are intricately related and cannot be addressed in isolation. With increasing population, increasing energy demand, continued migration towards and population growth within water stressed regions of the U.S., and with the continuing impacts of climat...
Increasing Early Childhood Preservice Teachers' Intercultural Sensitivity through the ABCs
ERIC Educational Resources Information Center
Monroe, Lisa; Ruan, Jiening
2018-01-01
While the early childhood student population has become increasingly diverse in the U.S., its teaching force remains primarily European American. The diverse student population demands that early childhood educators possess intercultural sensitivity in order to teach their culturally diverse learners effectively. This study examined the…
NASA Astrophysics Data System (ADS)
Butt, Edward W.; Turnock, Steven T.; Rigby, Richard; Reddington, Carly L.; Yoshioka, Masaru; Johnson, Jill S.; Regayre, Leighton A.; Pringle, Kirsty J.; Mann, Graham W.; Spracklen, Dominick V.
2017-04-01
Long-term exposure to ambient particulate matter (PM2.5, mass of particles with an aerodynamic dry diameter of < 2.5 μm) is associated with premature mortality. Previous studies have focussed on present day or future attributable health burdens. Few studies have estimated changes in PM2.5 concentrations and associated health burdens over the last few decades, a period where air quality has changed rapidly. Here we used the HadGEM3-UKCA coupled chemistry-climate model, integrated exposure-response relationships, demographic data and background disease prevalence to provide the first estimate of the changes in global and regional health burdens attributable to ambient PM2.5 exposure over the period 1960 to 2009. Over this period, simulated global mean population-weighted PM2.5 increased by 37% to 48% dominated by large increases over China (53% to 66%) and India (70% to 116%). We find that global attributable mortality due to long-term PM2.5 exposure increased by 124% to 147% between 1960 and 2009, substantially more than the increase in PM2.5 concentrations over the same period. This increase is dominated by India and China and is driven by population growth and an ageing population combined with increased PM2.5 concentrations. Our results show that PM2.5 concentrations in China and India will need to be reduced substantially to slow the increasing attributable health burdens that are being driven by population growth and an older population.
Increasing incidence of pyogenic spondylodiscitis: a 14-year population-based study.
Kehrer, Michala; Pedersen, Court; Jensen, Thøger G; Lassen, Annmarie T
2014-04-01
Smaller studies indicate that the incidence of pyogenic spondylodiscitis is increasing, possible related to a growing elderly population. Data supporting this is sparse, and we therefore studied patient characteristics and changes in spondylodiscitis incidence 1995-2008. In a population-based study we identified all patients aged ≥18 years treated for pyogenic spondylodiscitis in Funen County, Denmark (population 483 123). Annual incidences were determined. Demographics, symptoms and diagnostic methods were recorded. We found 192 cases: median age 66.6 years; 57.3% men; 76.6% culture positive cases. Staphylococcus aureus was the most common pathogen (55.1%). During 1995-2008 the overall incidence, incidence of culture negative cases, and incidence of cases due to S. aureus increased 2.2-5.8, 0.3-1.8, and 1.6-2.5 cases per 100 000 person years, respectively. The elderly had the highest incidence compared to those aged ≤70 years (rate ratio for men 5.9 (95% CI: 4.2-8.5) and for women 3.5 (95% CI: 2.3-5.3)). During 1995-2008 the overall incidence of S. aureus and culture negative cases of spondylodiscitis increased and remained highest among the elderly. Whether the increase is real or is a result of improved diagnostic methods and workup remains unknown. Copyright © 2013 The British Infection Association. Published by Elsevier Ltd. All rights reserved.
There is a perception among the population of the border communities that they have increased exposure due to their proximity to pollution sources in Mexico. This study provides exposure data for the border population that will be compared with data from a probabilistic exposure...
Comorbidity among older American Indians: the native elder care study.
Goins, R Turner; Pilkerton, Courtney S
2010-12-01
Comorbidity is a growing challenge and the older adult population is most at risk of developing comorbid conditions. Comorbidity is associated with increased risk of mortality, increased hospitalizations, increased doctor visits, increased prescription medications, nursing home placement, poorer mental health, and physical disability. American Indians experience some of the highest rates of chronic conditions, but to date there have been only two published studies on the subject of comorbidity in this population. With a community-based sample of 505 American Indians aged 55 years or older, this study identified the most prevalent chronic conditions, described comorbidity, and identified socio-demographic, functional limitations, and psychosocial correlates of comorbidity. Results indicated that older American Indians experience higher rates of hypertension, diabetes, back pain, and vision loss compared to national statistics of older adults. Two-thirds of the sample experienced some degree of comorbidity according to the scale used. Older age, poorer physical functioning, more depressive symptomatology, and lower personal mastery were all correlates of higher comorbidity scores. Despite medical advances increasing life expectancy, morbidity and mortality statistics suggest that the health of older American Indians lags behind the majority population. These findings highlight the importance of supporting chronic care and management services for the older American Indian population.
Prevalence of Diabetes and Associated Factors in the Uyghur and Han Population in Xinjiang, China.
Gong, Haiying; Pa, Lize; Wang, Ke; Mu, Hebuli; Dong, Fen; Ya, Shengjiang; Xu, Guodong; Tao, Ning; Pan, Li; Wang, Bin; Shan, Guangliang
2015-10-14
To estimate the prevalence of diabetes and identify risk factors in the Uyghur and Han population in Xinjiang, China. 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. 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. 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.
Pasaniuc, Bogdan; Zaitlen, Noah; Lettre, Guillaume; Chen, Gary K; Tandon, Arti; Kao, W H Linda; Ruczinski, Ingo; Fornage, Myriam; Siscovick, David S; Zhu, Xiaofeng; Larkin, Emma; Lange, Leslie A; Cupples, L Adrienne; Yang, Qiong; Akylbekova, Ermeg L; Musani, Solomon K; Divers, Jasmin; Mychaleckyj, Joe; Li, Mingyao; Papanicolaou, George J; Millikan, Robert C; Ambrosone, Christine B; John, Esther M; Bernstein, Leslie; Zheng, Wei; Hu, Jennifer J; Ziegler, Regina G; Nyante, Sarah J; Bandera, Elisa V; Ingles, Sue A; Press, Michael F; Chanock, Stephen J; Deming, Sandra L; Rodriguez-Gil, Jorge L; Palmer, Cameron D; Buxbaum, Sarah; Ekunwe, Lynette; Hirschhorn, Joel N; Henderson, Brian E; Myers, Simon; Haiman, Christopher A; Reich, David; Patterson, Nick; Wilson, James G; Price, Alkes L
2011-04-01
While genome-wide association studies (GWAS) have primarily examined populations of European ancestry, more recent studies often involve additional populations, including admixed populations such as African Americans and Latinos. In admixed populations, linkage disequilibrium (LD) exists both at a fine scale in ancestral populations and at a coarse scale (admixture-LD) due to chromosomal segments of distinct ancestry. Disease association statistics in admixed populations have previously considered SNP association (LD mapping) or admixture association (mapping by admixture-LD), but not both. Here, we introduce a new statistical framework for combining SNP and admixture association in case-control studies, as well as methods for local ancestry-aware imputation. We illustrate the gain in statistical power achieved by these methods by analyzing data of 6,209 unrelated African Americans from the CARe project genotyped on the Affymetrix 6.0 chip, in conjunction with both simulated and real phenotypes, as well as by analyzing the FGFR2 locus using breast cancer GWAS data from 5,761 African-American women. We show that, at typed SNPs, our method yields an 8% increase in statistical power for finding disease risk loci compared to the power achieved by standard methods in case-control studies. At imputed SNPs, we observe an 11% increase in statistical power for mapping disease loci when our local ancestry-aware imputation framework and the new scoring statistic are jointly employed. Finally, we show that our method increases statistical power in regions harboring the causal SNP in the case when the causal SNP is untyped and cannot be imputed. Our methods and our publicly available software are broadly applicable to GWAS in admixed populations.
International study of temperature, heat and urban mortality: the 'ISOTHURM' project.
McMichael, Anthony J; Wilkinson, Paul; Kovats, R Sari; Pattenden, Sam; Hajat, Shakoor; Armstrong, Ben; Vajanapoom, Nitaya; Niciu, Emilia M; Mahomed, Hassan; Kingkeow, Chamnong; Kosnik, Mitja; O'Neill, Marie S; Romieu, Isabelle; Ramirez-Aguilar, Matiana; Barreto, Mauricio L; Gouveia, Nelson; Nikiforov, Bojidar
2008-10-01
This study describes heat- and cold-related mortality in 12 urban populations in low- and middle-income countries, thereby extending knowledge of how diverse populations, in non-OECD countries, respond to temperature extremes. The cities were: Delhi, Monterrey, Mexico City, Chiang Mai, Bangkok, Salvador, São Paulo, Santiago, Cape Town, Ljubljana, Bucharest and Sofia. For each city, daily mortality was examined in relation to ambient temperature using autoregressive Poisson models (2- to 5-year series) adjusted for season, relative humidity, air pollution, day of week and public holidays. Most cities showed a U-shaped temperature-mortality relationship, with clear evidence of increasing death rates at colder temperatures in all cities except Ljubljana, Salvador and Delhi and with increasing heat in all cities except Chiang Mai and Cape Town. Estimates of the temperature threshold below which cold-related mortality began to increase ranged from 15 degrees C to 29 degrees C; the threshold for heat-related deaths ranged from 16 degrees C to 31 degrees C. Heat thresholds were generally higher in cities with warmer climates, while cold thresholds were unrelated to climate. Urban populations, in diverse geographic settings, experience increases in mortality due to both high and low temperatures. The effects of heat and cold vary depending on climate and non-climate factors such as the population disease profile and age structure. Although such populations will undergo some adaptation to increasing temperatures, many are likely to have substantial vulnerability to climate change. Additional research is needed to elucidate vulnerability within populations.
Randomness and diversity matter in the maintenance of the public resources
NASA Astrophysics Data System (ADS)
Liu, Aizhi; Zhang, Yanling; Chen, Xiaojie; Sun, Changyin
2017-03-01
Most previous models about the public goods game usually assume two possible strategies, i.e., investing all or nothing. The real-life situation is rarely all or nothing. In this paper, we consider that multiple strategies are adopted in a well-mixed population, and each strategy represents an investment to produce the public goods. Past efforts have found that randomness matters in the evolution of fairness in the ultimatum game. In the framework involving no other mechanisms, we study how diversity and randomness influence the average investment of the population defined by the mean value of all individuals' strategies. The level of diversity is increased by increasing the strategy number, and the level of randomness is increased by increasing the mutation probability, or decreasing the population size or the selection intensity. We find that a higher level of diversity and a higher level of randomness lead to larger average investment and favor more the evolution of cooperation. Under weak selection, the average investment changes very little with the strategy number, the population size, and the mutation probability. Under strong selection, the average investment changes very little with the strategy number and the population size, but changes a lot with the mutation probability. Under intermediate selection, the average investment increases significantly with the strategy number and the mutation probability, and decreases significantly with the population size. These findings are meaningful to study how to maintain the public resource.
Enhanced leaf nitrogen status stabilizes omnivore population density.
Liman, Anna-Sara; Dalin, Peter; Björkman, Christer
2017-01-01
Plant traits can mediate the strength of interactions between omnivorous predators and their prey through density effects and changes in the omnivores' trophic behavior. In this study, we explored the established assumption that enhanced nutrient status in host plants strengthens the buffering effect of plant feeding for omnivorous predators, i.e., prevents rapid negative population growth during prey density decline and thereby increases and stabilizes omnivore population density. We analyzed 13 years of field data on population densities of a heteropteran omnivore on Salix cinerea stands, arranged along a measured leaf nitrogen gradient and found a 195 % increase in omnivore population density and a 63 % decrease in population variability with an increase in leaf nitrogen status from 26 to 40 mgN × g -1 . We recreated the leaf nitrogen gradient in a greenhouse experiment and found, as expected, that increasing leaf nitrogen status enhanced omnivore performance but reduced per capita prey consumption. Feeding on high nitrogen status host plants can potentially decouple omnivore-prey population dynamics and allow omnivores to persist and function effectively at low prey densities to provide "background level" control of insect herbivores. This long-term effect is expected to outweigh the short-term effect on per capita prey consumption-resulting in a net increase in population predation rates with increasing leaf nitrogen status. Conservation biological control of insect pests that makes use of omnivore background control could, as a result, be manipulated via management of crop nitrogen status.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kostova, T; Carlsen, T
We present a study, based on simulations with SERDYCA, a spatially-explicit individual-based model of rodent dynamics, on the relation between population persistence and the presence of numerous isolated disturbances in the habitat. We are specifically interested in the effect of disturbances that do not fragment the environment on population persistence. Our results suggest that the presence of disturbances in the absence of fragmentation can actually increase the average time to extinction of the modeled population. The presence of disturbances decreases population density but can increase the chance for mating in monogamous species and consequently, the ratio of juveniles in themore » population. It thus provides a better chance for the population to restore itself after a severe period with critically low population density. We call this the ''disturbance-forced localization effect''.« less
Zhang, Rui-Chang; Lin, Yue; Yue, Ming; Li, Qian; Zhang, Xiao-Fei; Liu, Xiao; Chi, Hong; Chai, Yong-Fu; Wang, Mao
2012-01-01
(1) The effects of facilitation on the structure and dynamics of plant populations have not been studied so widely as competition. The UV-B radiation, as a typical environmental factor causing stress, may result in direct stress and facilitation. (2) The effects of UV-B radiation on intraspecific competition and facilitation were investigated based on the following three predictions on self-thinning, size inequality, and phenotypic plasticity: i) Self-thinning is the reduction in density that results from the increase in the mean biomass of individuals in crowded populations, and is driven by competition. In this study, the mortality rate of the population is predicted to decrease from UV-B irradiance. ii) The size inequality of a population increases with competition intensity because larger individuals receive a disproportionate share of resources, thereby leaving limited resources for smaller individuals. The second hypothesis assumes that direct stress decreases the size inequality of the population. iii) Phenotypic plasticity is the ability to alter one's morphology in response to environmental changes. The third hypothesis assumes that certain morphological indices can change among the trade-offs between competition, facilitation, and stress. These predictions were tested by conducting a field pot experiment using mung beans, and were supported by the following results: (3) UV-B radiation increased the survival rate of the population at the end of self-thinning. However, this result was mainly due to direct stress rather than facilitation. (4) Just as competitor, facilitation was also asymmetric. It increased the size inequality of populations during self-thinning, whereas stress decreased the size inequality. (5) Direct stress and facilitation influence plants differently on various scales. Stress inhibited plant growth, whereas facilitation showed the opposite on an individual scale. Stress increased survival rate, whereas facilitation increased individual variability on the population scale. (6) Trade-offs between competitions, facilitation, and direct stress varied in different growing stages.
Zhang, Rui-Chang; Lin, Yue; Yue, Ming; Li, Qian; Zhang, Xiao-Fei; Liu, Xiao; Chi, Hong; Chai, Yong-Fu; Wang, Mao
2012-01-01
(1) The effects of facilitation on the structure and dynamics of plant populations have not been studied so widely as competition. The UV-B radiation, as a typical environmental factor causing stress, may result in direct stress and facilitation. (2) The effects of UV-B radiation on intraspecific competition and facilitation were investigated based on the following three predictions on self-thinning, size inequality, and phenotypic plasticity: i) Self-thinning is the reduction in density that results from the increase in the mean biomass of individuals in crowded populations, and is driven by competition. In this study, the mortality rate of the population is predicted to decrease from UV-B irradiance. ii) The size inequality of a population increases with competition intensity because larger individuals receive a disproportionate share of resources, thereby leaving limited resources for smaller individuals. The second hypothesis assumes that direct stress decreases the size inequality of the population. iii) Phenotypic plasticity is the ability to alter one’s morphology in response to environmental changes. The third hypothesis assumes that certain morphological indices can change among the trade-offs between competition, facilitation, and stress. These predictions were tested by conducting a field pot experiment using mung beans, and were supported by the following results: (3) UV-B radiation increased the survival rate of the population at the end of self-thinning. However, this result was mainly due to direct stress rather than facilitation. (4) Just as competitor, facilitation was also asymmetric. It increased the size inequality of populations during self-thinning, whereas stress decreased the size inequality. (5) Direct stress and facilitation influence plants differently on various scales. Stress inhibited plant growth, whereas facilitation showed the opposite on an individual scale. Stress increased survival rate, whereas facilitation increased individual variability on the population scale. (6) Trade-offs between competitions, facilitation, and direct stress varied in different growing stages. PMID:23226393
Effects of yearling, juvenile and adult survival on reef manta ray (Manta alfredi) demography
van der Ouderaa, Isabelle B.C.; Tibiriçá, Yara
2016-01-01
Background The trade in manta ray gill plates has considerably increased over the last two decades. The resulting increases in ray mortality, in addition to mortality caused by by-catch, has caused many ray populations to decrease in size. The aim of this study was to ascertain how yearling and juvenile growth and survival, and adult survival and reproduction affect reef manta ray (Manta alfredi) population change, to increase our understanding of manta ray demography and thereby improve conservation research and measures for these fish. Methods We developed a population projection model for reef manta rays, and used published life history data on yearling and juvenile growth and adult reproduction to parameterise the model. Because little is known about reef manta ray yearling and juvenile survival, we conducted our analyses using a range of plausible survival rate values for yearlings, juveniles and adults. Results The model accurately captured observed variation in population growth rate, lifetime reproductive success and cohort generation time in different reef manta ray populations. Our demographic analyses revealed a range of population consequences in response to variation in demographic rates. For example, an increase in yearling or adult survival rates always elicited greater responses in population growth rate, lifetime reproductive success and cohort generation time than the same increase in juvenile survival rate. The population growth rate increased linearly, but lifetime reproductive success and cohort generation time increased at an accelerating rate with increasing yearling or adult survival rates. Hence, even a small increase in survival rate could increase lifetime reproductive success by one pup, and cohort generation time by several years. Elasticity analyses revealed that, depending on survival rate values of all life stages, the population growth rate is either most sensitive to changes in the rate with which juveniles survive but stay juveniles (i.e., do not mature into adults) or to changes in adult survival rate. However, when assessing these results against estimates on population growth and adult survival rates for populations off the coasts of Mozambique and Japan, we found that the population growth rate is predicted to be always most sensitive to changes in the adult survival rate. Discussion It is important to gain an in-depth understanding of reef manta ray life histories, particularly of yearling and adult survival rates, as these can influence reef manta ray population dynamics in a variety of ways. For declining populations in particular, it is crucial to know which life stage should be targeted for their conservation. For one such declining population off the coast of Mozambique, adult annual survival rate has the greatest effect on population growth, and by increasing adult survival by protecting adult aggregation sites, this population’s decline could be halted or even reversed. PMID:27635337
What interventions increase commuter cycling? A systematic review.
Stewart, Glenn; Anokye, Nana Kwame; Pokhrel, Subhash
2015-08-14
To identify interventions that will increase commuter cycling. All settings where commuter cycling might take place. Adults (aged 18+) in any country. Individual, group or environmental interventions including policies and infrastructure. A wide range of 'changes in commuter cycling' indicators, including frequency of cycling, change in workforce commuting mode, change in commuting population transport mode, use of infrastructure by defined populations and population modal shift. 12 studies from 6 countries (6 from the UK, 2 from Australia, 1 each from Sweden, Ireland, New Zealand and the USA) met the inclusion criteria. Of those, 2 studies were randomised control trials and the remainder preintervention and postintervention studies. The majority of studies (n=7) evaluated individual-based or group-based interventions and the rest environmental interventions. Individual-based or group-based interventions in 6/7 studies were found to increase commuter cycling of which the effect was significant in only 3/6 studies. Environmental interventions, however, had small but positive effects in much larger but more difficult to define populations. Almost all studies had substantial loss to follow-up. Despite commuter cycling prevalence varying widely between countries, robust evidence of what interventions will increase commuter cycling in low cycling prevalence nations is sparse. Wider environmental interventions that make cycling conducive appear to reach out to hard to define but larger populations. This could mean that environmental interventions, despite their small positive effects, have greater public health significance than individual-based or group-based measures because those interventions encourage a larger number of people to integrate physical activity into their everyday lives. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
What interventions increase commuter cycling? A systematic review
Stewart, Glenn; Anokye, Nana Kwame; Pokhrel, Subhash
2015-01-01
Objective To identify interventions that will increase commuter cycling. Setting All settings where commuter cycling might take place. Participants Adults (aged 18+) in any country. Interventions Individual, group or environmental interventions including policies and infrastructure. Primary and secondary outcome measures A wide range of ‘changes in commuter cycling’ indicators, including frequency of cycling, change in workforce commuting mode, change in commuting population transport mode, use of infrastructure by defined populations and population modal shift. Results 12 studies from 6 countries (6 from the UK, 2 from Australia, 1 each from Sweden, Ireland, New Zealand and the USA) met the inclusion criteria. Of those, 2 studies were randomised control trials and the remainder preintervention and postintervention studies. The majority of studies (n=7) evaluated individual-based or group-based interventions and the rest environmental interventions. Individual-based or group-based interventions in 6/7 studies were found to increase commuter cycling of which the effect was significant in only 3/6 studies. Environmental interventions, however, had small but positive effects in much larger but more difficult to define populations. Almost all studies had substantial loss to follow-up. Conclusions Despite commuter cycling prevalence varying widely between countries, robust evidence of what interventions will increase commuter cycling in low cycling prevalence nations is sparse. Wider environmental interventions that make cycling conducive appear to reach out to hard to define but larger populations. This could mean that environmental interventions, despite their small positive effects, have greater public health significance than individual-based or group-based measures because those interventions encourage a larger number of people to integrate physical activity into their everyday lives. PMID:26275902
Genotype imputation in a coalescent model with infinitely-many-sites mutation
Huang, Lucy; Buzbas, Erkan O.; Rosenberg, Noah A.
2012-01-01
Empirical studies have identified population-genetic factors as important determinants of the properties of genotype-imputation accuracy in imputation-based disease association studies. Here, we develop a simple coalescent model of three sequences that we use to explore the theoretical basis for the influence of these factors on genotype-imputation accuracy, under the assumption of infinitely-many-sites mutation. Employing a demographic model in which two populations diverged at a given time in the past, we derive the approximate expectation and variance of imputation accuracy in a study sequence sampled from one of the two populations, choosing between two reference sequences, one sampled from the same population as the study sequence and the other sampled from the other population. We show that under this model, imputation accuracy—as measured by the proportion of polymorphic sites that are imputed correctly in the study sequence—increases in expectation with the mutation rate, the proportion of the markers in a chromosomal region that are genotyped, and the time to divergence between the study and reference populations. Each of these effects derives largely from an increase in information available for determining the reference sequence that is genetically most similar to the sequence targeted for imputation. We analyze as a function of divergence time the expected gain in imputation accuracy in the target using a reference sequence from the same population as the target rather than from the other population. Together with a growing body of empirical investigations of genotype imputation in diverse human populations, our modeling framework lays a foundation for extending imputation techniques to novel populations that have not yet been extensively examined. PMID:23079542
Slart, Riemer H.J.A.; Hulleman, Enzo V.; Dierckx, Rudi A.J.O.; Velthuis, Birgitta K.; van der Harst, Pim; Sosnovik, David E.; Borra, Ronald J.H.; Prakken, Niek H.J.
2017-01-01
Background Although cardiac MR and T1 mapping are increasingly used to diagnose diffuse fibrosis based cardiac diseases, studies reporting T1 values in healthy and diseased myocardium, particular in nonischemic cardiomyopathies (NICM) and populations with increased cardiovascular risk, seem contradictory. Purpose To determine the range of native myocardial T1 value ranges in patients with NICM and populations with increased cardiovascular risk. Study Type Systemic review and meta‐analysis. Population Patients with NICM, including hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM), and patients with myocarditis (MC), iron overload, amyloidosis, Fabry disease, and populations with hypertension (HT), diabetes mellitus (DM), and obesity. Field Strength/Sequence (Shortened) modified Look–Locker inversion‐recovery MR sequence at 1.5 or 3T. Assessment PubMed and Embase were searched following the PRISMA guidelines. Statistical Tests The summary of standard mean difference (SMD) between the diseased and a healthy control populations was generated using a random‐effects model in combination with meta‐regression analysis. Results The SMD for HCM, DCM, and MC patients were significantly increased (1.41, 1.48, and 1.96, respectively, P < 0.01) compared with healthy controls. The SMD for HT patients with and without left‐ventricle hypertrophy (LVH) together was significantly increased (0.19, P = 0.04), while for HT patients without LVH the SMD was zero (0.03, P = 0.52). The number of studies on amyloidosis, iron overload, Fabry disease, and HT patients with LVH did not meet the requirement to perform a meta‐analysis. However, most studies reported a significantly increased T1 for amyloidosis and HT patients with LVH and a significant decreased T1 for iron overload and Fabry disease patients. Data Conclusions Native T1 mapping by using an (Sh)MOLLI sequence can potentially assess myocardial changes in HCM, DCM, MC, iron overload, amyloidosis, and Fabry disease compared to controls. In addition, it can help to diagnose left‐ventricular remodeling in HT patients. Level of Evidence: 2 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:891–912. PMID:29131444
Deutsch, Madeline B
2016-06-01
An accurate estimate of the number of transgender and gender nonconforming people is essential to inform policy and funding priorities and decisions. Historical reports of population sizes of 1 in 4000 to 1 in 50,000 have been based on clinical populations and likely underestimate the size of the transgender population. More recent population-based studies have found a 10- to 100-fold increase in population size. Studies that estimate population size should be population based, employ the two-step method to allow for collection of both gender identity and sex assigned at birth, and include measures to capture the range of transgender people with nonbinary gender identities.
No population genetic structure in a widespread aquatic songbird from the Neotropics
Cadena, Carlos Daniel; Gutierrez-Pinto, Natalia; Davila, Nicolas; Chesser, R. Terry
2011-01-01
Neotropical lowland organisms often show marked population genetic structure, suggesting restricted migration among populations. However, most phylogeographic studies have focused on species inhabiting humid forest interior. Little attention has been devoted to the study of species with ecologies conducive to dispersal, such as those of more open and variable environments associated with watercourses. Using mtDNA sequences, we examined patterns of genetic variation in a widely distributed Neotropical songbird of aquatic environments, the Yellow-hooded Blackbird (Icteridae, Chrysomus icterocephalus). In contrast to many forest species, Yellow-hooded Blackbirds showed no detectable genetic structure across their range, which includes lowland populations on both sides of the Andes, much of northeastern South America, Amazonia, as well as a phenotypically distinct highland population in Colombia. A coalescent-based analysis of the species indicated that its effective population size has increased considerably, suggesting a range expansion. Our results support the hypothesis that species occurring in open habitats and tracking temporally dynamic environments should show increased dispersal propensities (hence gene flow) relative to species from closed and more stable environments. The phenotypic and behavioral variation among populations of our study species appears to have arisen recently and perhaps in the face of gene flow.
Projected effects of climate and development on California wildfire emissions through 2100.
Hurteau, Matthew D; Westerling, Anthony L; Wiedinmyer, Christine; Bryant, Benjamin P
2014-02-18
Changing climatic conditions are influencing large wildfire frequency, a globally widespread disturbance that affects both human and natural systems. Understanding how climate change, population growth, and development patterns will affect the area burned by and emissions from wildfires and how populations will in turn be exposed to emissions is critical for climate change adaptation and mitigation planning. We quantified the effects of a range of population growth and development patterns in California on emission projections from large wildfires under six future climate scenarios. Here we show that end-of-century wildfire emissions are projected to increase by 19-101% (median increase 56%) above the baseline period (1961-1990) in California for a medium-high temperature scenario, with the largest emissions increases concentrated in northern California. In contrast to other measures of wildfire impacts previously studied (e.g., structural loss), projected population growth and development patterns are unlikely to substantially influence the amount of projected statewide wildfire emissions. However, increases in wildfire emissions due to climate change may have detrimental impacts on air quality and, combined with a growing population, may result in increased population exposure to unhealthy air pollutants.
Lutz, Wolfgang; KC, Samir
2010-01-01
The total size of the world population is likely to increase from its current 7 billion to 8–10 billion by 2050. This uncertainty is because of unknown future fertility and mortality trends in different parts of the world. But the young age structure of the population and the fact that in much of Africa and Western Asia, fertility is still very high makes an increase by at least one more billion almost certain. Virtually, all the increase will happen in the developing world. For the second half of the century, population stabilization and the onset of a decline are likely. In addition to the future size of the population, its distribution by age, sex, level of educational attainment and place of residence are of specific importance for studying future food security. The paper provides a detailed discussion of different relevant dimensions in population projections and an evaluation of the methods and assumptions used in current global population projections and in particular those produced by the United Nations and by IIASA. PMID:20713384
Wahman, Kerstin; Nash, Mark S; Lewis, John E; Seiger, Ake; Levi, Richard
2010-05-01
Comparison of prevalence of cardiovascular disease risks in persons with chronic traumatic paraplegia with those in the general population. Cross-sectional comparative study. A total of 135 individuals, age range 18-79 years, with chronic (> or = 1 year) traumatic paraplegia. The prevalences of diabetes mellitus, dyslipidaemia, hypertension, overweight, and smoking, were assessed in the study population and were compared with an age- and gender-matched sample of the general population in the region under study. History of myocardial infarction and medication for dyslipidaemia, hypertension, and diabetes mellitus were also recorded. chi2 tests were used to compare the paraplegic cohort with the general population sample. Significantly more persons with paraplegia reported a history of myocardial infarction (5.9%) than those in the comparison group (0.7%). The prevalences of diabetes mellitus (5.9%), dyslipidaemia (11.1%), and hypertension (14.1%) were also significantly higher in the paraplegic group, as were drug treatment for these disorders. Persons with paraplegia report increased prevalences of diabetes mellitus, hypertension, and dyslipidaemia, in particular, compared with the general population. Population-based screening and therapeutic counter-measures for these conditions may therefore be particularly indicated for this patient group.
Ohta, T.
1992-01-01
There are several unsolved problems concerning the model of nearly neutral mutations. One is the interaction of subdivided population structure and weak selection that spatially fluctuates. The model of nearly neutral mutations whose selection coefficient spatially fluctuates has been studied by adopting the island model with periodic extinction-recolonization. Both the number of colonies and the migration rate play significant roles in determining mutants' behavior, and selection is ineffective when the extinction-recolonization is frequent with low migration rate. In summary, the number of mutant substitutions decreases and the polymorphism increases by increasing the total population size, and/or decreasing the extinction-recolonization rate. However, by increasing the total size of the population, the mutant substitution rate does not become as low when compared with that in panmictic populations, because of the extinction-recolonization, especially when the migration rate is limited. It is also found that the model satisfactorily explains the contrasting patterns of molecular polymorphisms observed in sibling species of Drosophila, including heterozygosity, proportion of polymorphism and fixation index. PMID:1582566
Whiteman, Noah Kerness; Matson, Kevin D; Bollmer, Jennifer L; Parker, Patricia G
2005-01-01
An increased susceptibility to disease is one hypothesis explaining how inbreeding hastens extinction in island endemics and threatened species. Experimental studies show that disease resistance declines as inbreeding increases, but data from in situ wildlife systems are scarce. Genetic diversity increases with island size across the entire range of an extremely inbred Galápagos endemic bird, providing the context for a natural experiment examining the effects of inbreeding on disease susceptibility. Extremely inbred populations of Galápagos hawks had higher parasite abundances than relatively outbred populations. We found a significant island effect on constitutively produced natural antibody (NAb) levels and inbred populations generally harboured lower average and less variable NAb levels than relatively outbred populations. Furthermore, NAb levels explained abundance of amblyceran lice, which encounter the host immune system. This is the first study linking inbreeding, innate immunity and parasite load in an endemic, in situ wildlife population and provides a clear framework for assessment of disease risk in a Galápagos endemic. PMID:16618672
Isolation mediates persistent founder effects on zooplankton colonisation in new temporary ponds
Badosa, Anna; Frisch, Dagmar; Green, Andy J.; Rico, Ciro; Gómez, Africa
2017-01-01
Understanding the colonisation process in zooplankton is crucial for successful restoration of aquatic ecosystems. Here, we analyzed the clonal and genetic structure of the cyclical parthenogenetic rotifer Brachionus plicatilis by following populations established in new temporary ponds during the first three hydroperiods. Rotifer populations established rapidly after first flooding, although colonisation was ongoing throughout the study. Multilocus genotypes from 7 microsatellite loci suggested that most populations (10 of 14) were founded by few clones. The exception was one of the four populations that persisted throughout the studied hydroperiods, where high genetic diversity in the first hydroperiod suggested colonisation from a historical egg bank, and no increase in allelic diversity was detected with time. In contrast, in another of these four populations, we observed a progressive increase of allelic diversity. This population became less differentiated from the other populations suggesting effective gene flow soon after its foundation. Allelic diversity and richness remained low in the remaining two, more isolated, populations, suggesting little gene flow. Our results highlight the complexity of colonisation dynamics, with evidence for persistent founder effects in some ponds, but not in others, and with early immigration both from external source populations, and from residual, historical diapausing egg banks. PMID:28276459
Isolation mediates persistent founder effects on zooplankton colonisation in new temporary ponds
NASA Astrophysics Data System (ADS)
Badosa, Anna; Frisch, Dagmar; Green, Andy J.; Rico, Ciro; Gómez, Africa
2017-03-01
Understanding the colonisation process in zooplankton is crucial for successful restoration of aquatic ecosystems. Here, we analyzed the clonal and genetic structure of the cyclical parthenogenetic rotifer Brachionus plicatilis by following populations established in new temporary ponds during the first three hydroperiods. Rotifer populations established rapidly after first flooding, although colonisation was ongoing throughout the study. Multilocus genotypes from 7 microsatellite loci suggested that most populations (10 of 14) were founded by few clones. The exception was one of the four populations that persisted throughout the studied hydroperiods, where high genetic diversity in the first hydroperiod suggested colonisation from a historical egg bank, and no increase in allelic diversity was detected with time. In contrast, in another of these four populations, we observed a progressive increase of allelic diversity. This population became less differentiated from the other populations suggesting effective gene flow soon after its foundation. Allelic diversity and richness remained low in the remaining two, more isolated, populations, suggesting little gene flow. Our results highlight the complexity of colonisation dynamics, with evidence for persistent founder effects in some ponds, but not in others, and with early immigration both from external source populations, and from residual, historical diapausing egg banks.
Raz, Raanan; Weisskopf, Marc G; Davidovitch, Michael; Pinto, Ofir; Levine, Hagai
2014-01-01
We analyzed data from the Israeli National Insurance Institute (NII). Autism Spectrum Disorder (ASD) incidence was calculated for all children born in Israel 1992-2009, and by population groups. Overall, 9,109 ASD cases among 2,431,649 children were identified. ASD cumulative incidence by age 8 years increased 10-fold during 2000-2011, from 0.049% to 0.49%, while other child disabilities in NII increased only 1.65-fold. There was a consistent increase in ASD incidence with advancing birth cohorts born 1992-2004, stabilizing among those born 2005-2009. ASD rates among Israeli Arabs were substantially lower, and increased about 10 years later than the general population. The findings suggest a role for ASD awareness, accessing of the government benefit, or the way the concept of ASD is perceived. PMID:25287899
Colony-Level Differences in the Scaling Rules Governing Wood Ant Compound Eye Structure.
Perl, Craig D; Niven, Jeremy E
2016-04-12
Differential organ growth during development is essential for adults to maintain the correct proportions and achieve their characteristic shape. Organs scale with body size, a process known as allometry that has been studied extensively in a range of organisms. Such scaling rules, typically studied from a limited sample, are assumed to apply to all members of a population and/or species. Here we study scaling in the compound eyes of workers of the wood ant, Formica rufa, from different colonies within a single population. Workers' eye area increased with body size in all the colonies showing a negative allometry. However, both the slope and intercept of some allometric scaling relationships differed significantly among colonies. Moreover, though mean facet diameter and facet number increased with body size, some colonies primarily increased facet number whereas others increased facet diameter, showing that the cellular level processes underlying organ scaling differed among colonies. Thus, the rules that govern scaling at the organ and cellular levels can differ even within a single population.
Wang, Sheng-Yin; Zhou, Xian-Hong; Zhang, An-Sheng; Li, Li-Li; Men, Xing-Yuan; Zhang, Si-Cong; Liu, Yong-Jie; Yu, Yi
2012-07-01
To understand the resistance risks of Frankliniella occidentalis Pergande against phoxim, this paper studied the resistance mechanisms of phoxim-resistant F. occidentalis population against phoxim and the cross-resistance of the population against other insecticides. The phoxim-resistant population had medium level cross-resistance to chlorpyrifos, lambda-cyhalothrin, and methomyl, low level cross-resistance to chlorfenapyr, imidacloprid, emamectin-benzoate, and spinosad, but no cross-resistance to acetamiprid and abamectin. The synergists piperonyl butoxide (PBO), s, s, s-tributyl phosphorotrithioate (DEF), and triphenyl phosphate (TPP) had significant synergism (P < 0.05) on the toxicity of phoxim to the resistant (XK), field (BJ), and susceptible (S) populations, while diethyl maleate (DEM) had no significant synergism to XK and S populations but had significant synergism to BJ population. As compared with S population, the XK and BJ populations had significantly increased activities of mixed-functional oxidases P450 (2.79-fold and 1.48-fold), b, (2.88-fold and 1.88-fold), O-demethylase (2.60-fold and 1.68-fold), and carboxylesterase (2.02-fold and 1.61-fold, respectively), and XK population had a significantly increased acetylcholine esterase activity (3.10-fold). Both XK and BJ population had an increased activity of glutathione S-transferases (1.11-fold and 1.20-fold, respectively), but the increment was not significant. The increased detoxification enzymes activities in F. occidentalis could play an important role in the resistance of the plant against phoxim.
Wang, Ji-Wei; Cui, Zhi-Ting; Cui, Hong-Wei; Wei, Chang-Nian; Harada, Koichi; Minamoto, Keiko; Ueda, Kimiyo; Ingle, Kapilkumar N; Zhang, Cheng-Gang; Ueda, Atsushi
2010-12-01
The floating population refers to the large and increasing number of migrants without local household registration status and has become a new demographic phenomenon in China. Most of these migrants move from the rural areas of the central and western parts of China to the eastern and coastal metropolitan areas in pursuit of a better life. The floating population of China was composed of 121 million people in 2000, and this number was expected to increase to 300 million by 2010. Quality of life (QOL) studies of the floating population could provide a critical starting point for recognizing the potential of regions, cities and local communities to improve QOL. This study explored the construct of QOL of the floating population in Shanghai, China. We conducted eight focus groups with 58 members of the floating population (24 males and 34 females) and then performed a qualitative thematic analysis of the interviews. The following five QOL domains were identified from the analysis: personal development, jobs and career, family life, social relationships and social security. The results indicated that stigma and discrimination permeate these life domains and influence the framing of life expectations. Proposals were made for reducing stigma and discrimination against the floating population to improve the QOL of this population.
Wood, Jacquelyn L A; Tezel, Defne; Joyal, Destin; Fraser, Dylan J
2015-09-01
How population size influences quantitative genetic variation and differentiation among natural, fragmented populations remains unresolved. Small, isolated populations might occupy poor quality habitats and lose genetic variation more rapidly due to genetic drift than large populations. Genetic drift might furthermore overcome selection as population size decreases. Collectively, this might result in directional changes in additive genetic variation (VA ) and trait differentiation (QST ) from small to large population size. Alternatively, small populations might exhibit larger variation in VA and QST if habitat fragmentation increases variability in habitat types. We explored these alternatives by investigating VA and QST using nine fragmented populations of brook trout varying 50-fold in census size N (179-8416) and 10-fold in effective number of breeders, Nb (18-135). Across 15 traits, no evidence was found for consistent differences in VA and QST with population size and almost no evidence for increased variability of VA or QST estimates at small population size. This suggests that (i) small populations of some species may retain adaptive potential according to commonly adopted quantitative genetic measures and (ii) populations of varying sizes experience a variety of environmental conditions in nature, however extremely large studies are likely required before any firm conclusions can be made. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.
Traditional Knowledge of Rainwater Harvesting Compared to Five Modern Case Studies (proceedings)
The water-energy-food nexus is receiving increased attention worldwide due to climate change and rising population. According to a projection of the United Nations, the global population is expected to increase by a factor of 1.3 by 2050—from 7.2 billion to 9.6 billion—with corre...
Low-Cost Behavioral Nudges Increase Medicaid Take-Up Among Eligible Residents Of Oregon.
Wright, Bill J; Garcia-Alexander, Ginny; Weller, Margarette A; Baicker, Katherine
2017-05-01
Efforts to reduce the ranks of the uninsured hinge on take-up of available programs and subsidies, but take-up of even free insurance is often less than complete. The evidence of the effectiveness of policies aiming to increase take-up is limited. We used a randomized controlled design to evaluate the impact of improved communication and behaviorally informed "nudges" designed to increase Medicaid take-up among eligible populations. Fielding randomized interventions in two different study populations in Oregon, we found that even very low-cost interventions substantially increased enrollment. Effects were larger in a population whose members had already expressed interest in obtaining coverage, but the effects were more persistent in low-income populations whose members were already enrolled in other state assistance programs but had not expressed interest in health insurance. The effects were similar across different demographic groups. Our results suggest that improving the design of enrollment processes and using low-cost mass-outreach efforts have the potential to substantially increase insurance coverage of vulnerable populations. Project HOPE—The People-to-People Health Foundation, Inc.
Analysis of Urban Growth in Edwardsville Illinois Using Remote Sensing and Population Change
NASA Astrophysics Data System (ADS)
Onuoha, Hilda U.
Rapid urbanization is one of the many critical, global issues. This very significant social and economic phenomenon has brought about much debate in the past twenty years and has become a very important policy issue. Understanding its dynamics and patterns is important to develop appropriate policies and make more informed planning decisions. Many dimensions to the urban land growth have been identified in related literature including drivers, relationship with other factors like population, impacts, and methods of measurement. In this study, urban growth in the Edwardsville area (composed of Edwardsville and Glen Carbon, Illinois) is analyzed spatio-temporally using remote sensing and population change from 1990 to 2015. The objectives of this study are (a) identifying the major land use changes in the Edwardsville area from 1990 to 2015, (b) analyzing the rate of urban growth and its relationship to population change in the area from 1990 to 2015, (c) identifying the general pattern and direction of urban growth in the study area. Using multi-temporal satellite images to classify and derive changes in land cover classes during the study period, results showed that the land cover classes with major changes are the urban/built-up land and agricultural/grassland, with a steady increase in the former and steady decrease in the later. Results also show the highest rate of increase in urban land was between 2000 and 2010. In comparison to population, the both show increase over the study years but urban land shows a higher rate of increase indicating dispersion. To analyze urban growth pattern in the area, the study area was divided into three zones: NE, SE, and W. The SE zone showed the highest amount of the growth and from the results, the infill type of growth was inferred.
Relation between age and carotid artery intima-medial thickness: a systematic review.
van den Munckhof, Inge C L; Jones, Helen; Hopman, Maria T E; de Graaf, Jacqueline; Nyakayiru, Jean; van Dijk, Bart; Eijsvogels, Thijs M H; Thijssen, Dick H J
2018-05-12
Carotid artery intima-medial thickness (cIMT) represents a popular measure of atherosclerosis and is predictive of future cardiovascular and cerebrovascular events. Although older age is associated with a higher cIMT, little is known about whether this increase in cIMT follows a linear relationship with age or it is affected under influence of cardiovascular diseases (CVD) or CVD risk factors. We hypothesize that the relationship between cIMT and age is nonlinear and is affected by CVD or risk factors. A systematic review of studies that examined cIMT in the general population and human populations free from CVD/risk factors was undertaken. The literature search was conducted in PubMed, Scopus, and Web of Science. Seventeen studies with 32 unique study populations, involving 10,124 healthy individuals free from CVD risk factors, were included. Furthermore, 58 studies with 115 unique study populations were included, involving 65,774 individuals from the general population (with and without CVD risk factors). A strong positive association was evident between age and cIMT in the healthy population, demonstrating a gradual, linear increase in cIMT that did not differ between age decades (r = 0.91, P < 0.001). Although populations with individuals with CVD demonstrated a higher cIMT compared to populations free of CVD, a linear relation between age and cIMT was also present in this population. Our data suggest that cIMT is strongly and linearly related to age. This linear relationship was not affected by CVD or risk factors. © 2018 Wiley Periodicals, Inc.
Expansion of corals on temperate reefs: direct and indirect effects of marine heatwaves
NASA Astrophysics Data System (ADS)
Tuckett, C. A.; de Bettignies, T.; Fromont, J.; Wernberg, T.
2017-09-01
Globally, many temperate marine communities have experienced significant temperature increases over recent decades in the form of gradual warming and heatwaves. As a result, these communities are shifting towards increasingly subtropical and tropical species compositions. Expanding coral populations have been reported from several temperate reef ecosystems along warming coastlines; these changes have been attributed to direct effects of gradual warming over decades. In contrast, increases in coral populations following shorter-term extreme warming events have rarely been documented. In this study, we compared coral populations on 17 temperate reefs in Western Australia before (2005/06) and after (2013) multiple marine heatwaves (2010-2012) affected the entire coastline. We hypothesised that coral communities would expand and change as a consequence of increasing local populations and recruitment of warm-affinity species. We found differences in coral community structure over time, driven primarily by a fourfold increase of one local species, Plesiastrea versipora, rather than recruitment of warm-affinity species. Coral populations became strongly dominated by small size classes, indicative of recent increased recruitment or recruit survival. These changes were likely facilitated by competitive release of corals from dominant temperate seaweeds, which perished during the heatwaves, rather than driven by direct temperature effects. Overall, as corals are inherently warm-water taxa not commonly associated with seaweed-dominated temperate reefs, these findings are consistent with a net tropicalisation. Our study draws attention to processes other than gradual warming that also influence the trajectory of temperate reefs in a changing ocean.
Kim, Hyun Soo
2018-01-01
Aged population is increasing worldwide due to the aging process that is inevitable. Accordingly, longevity and healthy aging have been spotlighted to promote social contribution of aged population. Many studies in the past few decades have reported the process of aging and longevity, emphasizing the importance of maintaining genomic stability in exceptionally long-lived population. Underlying reason of longevity remains unclear due to its complexity involving multiple factors. With advances in sequencing technology and human genome-associated approaches, studies based on population-based genomic studies are increasing. In this review, we summarize recent longevity and healthy aging studies of human population focusing on DNA repair as a major factor in maintaining genome integrity. To keep pace with recent growth in genomic research, aging- and longevity-associated genomic databases are also briefly introduced. To suggest novel approaches to investigate longevity-associated genetic variants related to DNA repair using genomic databases, gene set analysis was conducted, focusing on DNA repair- and longevity-associated genes. Their biological networks were additionally analyzed to grasp major factors containing genetic variants of human longevity and healthy aging in DNA repair mechanisms. In summary, this review emphasizes DNA repair activity in human longevity and suggests approach to conduct DNA repair-associated genomic study on human healthy aging.
Stoeckel, James A; González, María J; Oris, James T; Kovach, Mathew J; Mace, Kimberly M
2008-11-01
Atrazine is one of the most commonly applied herbicides in North America and annually pulses through many midwestern stream and reservoir systems. Previous studies have yielded conflicting results regarding the ability of atrazine to stimulate male production by Daphnia, an effect hypothesized to lower population growth rates during a period of intense larval fish predation. In the present study, populations of Daphnia parvula and Daphnia ambigua exhibited high proportions of males but no ephippial females when atrazine pulsed into Acton Lake, a small midwestern reservoir. Field results thus supported the hypothesis of excess male production by Daphnia during the spring herbicide pulse. In laboratory studies, dose-response studies, and population-level assays revealed no effect of atrazine on male production or population growth rate of multiple clones differing in reproductive strategy and exposure history. However, D. parvula increased male production in response to an endogenous crustacean hormone (methyl farnesoate). Excess male production observed in the field population was therefore not likely caused by atrazine, although we cannot rule out the possibility of interactive effects of atrazine and some other stressor. Apparent signs of endocrine disruption in the presence of high concentrations of a suspected agent should be viewed with caution in the absence of parallel laboratory studies involving individuals from the populations of interest.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Vasilieva, A. N.; Voloshin, D. G.; Kovalev, A. S., E-mail: kovalev@dnph.phys.msu.su
2015-05-15
The behavior of the populations of two metastable and two lower resonance levels of argon atoms in the plasma of an RF capacitive discharge was studied. The populations were measured by two methods: the method of emission self-absorption and the method based on measurements of the intensity ratios of spectral lines. It is shown that the populations of resonance levels increase with increasing power deposited in the discharge, whereas the populations of metastable levels is independent of the RF power. The distribution of the populations over energy levels is not equilibrium under these conditions. The population kinetics of argon atomicmore » levels in the discharge plasma is simulated numerically. The distribution function of plasma electrons recovered from the measured populations of atomic levels and numerical simulations is found to be non-Maxwellian.« less
Population and prehistory II: Space-limited human populations in constant environments
Puleston, Cedric O.; Tuljapurkar, Shripad
2010-01-01
We present a population model to examine the forces that determined the quality and quantity of human life in early agricultural societies where cultivable area is limited. The model is driven by the non-linear and interdependent relationships between the age distribution of a population, its behavior and technology, and the nature of its environment. The common currency in the model is the production of food, on which age-specific rates of birth and death depend. There is a single nontrivial equilibrium population at which productivity balances caloric needs. One of the most powerful controls on equilibrium hunger level is fertility control. Gains against hunger are accompanied by decreases in population size. Increasing worker productivity does increase equilibrium population size but does not improve welfare at equilibrium. As a case study we apply the model to the population of a Polynesian valley before European contact. PMID:18598711
Population and prehistory II: space-limited human populations in constant environments.
Puleston, Cedric O; Tuljapurkar, Shripad
2008-09-01
We present a population model to examine the forces that determined the quality and quantity of human life in early agricultural societies where cultivable area is limited. The model is driven by the non-linear and interdependent relationships between the age distribution of a population, its behavior and technology, and the nature of its environment. The common currency in the model is the production of food, on which age-specific rates of birth and death depend. There is a single non-trivial equilibrium population at which productivity balances caloric needs. One of the most powerful controls on equilibrium hunger level is fertility control. Gains against hunger are accompanied by decreases in population size. Increasing worker productivity does increase equilibrium population size but does not improve welfare at equilibrium. As a case study we apply the model to the population of a Polynesian valley before European contact.
Nguyen, Vu H
2017-06-01
To determine the implications of the reviewed literature in population health improvement. A review of the literature was conducted with the search of four databases: PubMed, PsycINFO, ERIC, and Google Scholar. Search terms entered into these databases were 'osteoporosis community'. After a thorough review of all search results, 11 studies were found to be community osteoporosis screening services, and descriptions of each study's participants and location, details and descriptions of each study's community osteoporosis screening service, and effectiveness on outcome measure(s) for each study's objective were reviewed and examined to determine their implications on population health. Nine of the 11 studies on community osteoporosis screening services were conducted at community pharmacy settings, and all studies included participants that were all or mostly older women, with only three studies that included men as participants. In addition to osteoporosis screening, all studies included osteoporosis education and/or counseling with the exception of one study. Various outcome measures were assessed in these studies, and with the exception of osteoporosis treatment adherence, weight-bearing exercise and osteoporosis-specified quality of life, community osteoporosis screening services showed positive outcomes in increasing osteoporosis awareness, osteoporosis knowledge, osteoporosis risk identification, calcium intake, service satisfaction, primary care physician perspective, and financial sustainability. In particular, community osteoporosis screening services are helpful in identifying those with osteoporosis or are at moderate risk to high risk, and they are effective in increasing outcomes that help prevent osteoporotic fractures, such as osteoporosis medication prescription and calcium intake. Furthermore, participants feel satisfied in partaking in community osteoporosis screening services, primary care physicians do believe that they are useful, and they are financially stable as they earn profit net gains. Community osteoporosis screening services provide a cost-effective approach towards preventing osteoporotic fractures for population health, particularly in identifying osteoporosis or high risk of the disease in populations. This review determined preventive measures for osteoporotic fractures, such as increased calcium intake and osteoporosis medication prescriptions, resulting in decreased osteoporotic fractures and increased population health improvement.
Sha, Jingjing; Wang, You; Chen, Hongmei; Wang, Ming; Wang, Hong; Li, Xiaohong; Qi, Lei; Tang, Xuexi
2015-09-01
Polybrominated diphenyl ethers (PBDEs) are highly persistent anthropogenic contaminants found in the environment, posing a risk to aquatic ecosystems, whereas there is a lack of data concerning their impacts on marine invertebrates. The objective of this study was to assess the relative lethal and sublethal aquatic toxicity effects of two PBDEs, BDE-47 and BDE-209 congeners, on marine zooplankton rotifer Brachionus plicatilis associated with PBDE concentrations and time of exposure. Gas chromatography-mass spectrometry (GC-MS) analyses were performed to determine actual PBDE concentrations. Rotifer population demographic parameters from life tables, including age-specific survivorship (lx), age-specific fecundity (mx), net reproductive rate (R0), intrinsic rate of increase (rm), finite rate of increase (λ), life expectancy (E0) and generation time (T), were used as measures of treatment effects. Results from this study have revealed increasingly intense negative effects on many of the rotifer demographic parameters with elevated PBDE concentrations. The population growth curves of B. plicatilis showed almost no lag phase and reached peak abundances within 11 days, while B. plicatilis exposed to BDE-209 had a lag phase of about 5 days. In addition, increased PBDE levels reduced the population abundances and peak population densities of B. plicatilis. The two PBDEs have caused the carrying capacity (K) suppressed and the negative influence turned more serious as the concentration rose. Results also revealed that the time to reach growth curve inflection point (Tp) was shortened by PBDEs to different degrees. This study not only indicated that life table demography and population growth curve studies were two important aspects used to evaluate toxicant PBDE effects, but also compared the two PBDE disruptions to the population growth and reproduction of the rotifer. Copyright © 2015 Elsevier Inc. All rights reserved.
Epidemiology of Benign External Hydrocephalus in Norway-A Population-Based Study.
Wiig, Ulrikke S; Zahl, Sverre M; Egge, Arild; Helseth, Eirik; Wester, Knut
2017-08-01
Benign external hydrocephalus is defined as a rapidly increasing head circumference (occipitofrontal circumference) with characteristic radiological findings of increased subarachnoid cerebrospinal fluid spaces on neuroimaging. The incidence of benign external hydrocephalus has not been previously reported, and there is no available information on the ratio of benign external hydrocephalus in the population of hydrocephalic children. This study is retrospective and population-based study, geographically covering two health regions in the southern half of Norway with a total mean population of 3.34 million in the ten-year study period, constituting approximately 75% of the Norwegian population. Children with a head circumference crossing two percentiles, or greater than the 97.5th percentile, and with typical imaging findings of enlarged frontal subarachnoid spaces with or without enlarged ventricles were included. Children were excluded if they had a history of head trauma, intracranial hemorrhage, central nervous system infection, other known causes of hydrocephalus, or were born preterm defined as birth before 37 weeks of gestation. A total of 176 children fitting the criteria were identified, giving an incidence of 0.4 per 1000 live births. One hundred fifty-two (86.4%) of the patients were male, and mean age at referral was 7.3 months. Increasing head circumference was the main reason for referral in 158 (89.8%) patients and the only finding in 60 (34.1%) patients. Thirty-seven (21%) children had normal ventricles on imaging; the remainder had increased ventricular size. The incidence of pediatric hydrocephalus in Norway is reported to be 0.75 per 1000 live births, thus benign external hydrocephalus accounts for approximately 50% of hydrocephalic conditions in this population. The incidence of benign external hydrocephalus was found to be 0.4 per 1000 live births in this population. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.
Roca-Acevedo, G; Picollo, M I; Capriotti, N; Sierra, I; Santo-Orihuela, P L
2015-09-01
Chagas disease is a zoonosis transmitted to man by blood-sucking triatomine bugs found in the Americas. Triatoma infestans (Klug, 1834) is the main vector of Chagas' disease in Argentina. The control of this illness relies heavily on vector control through the use of insecticide. However, resistance to pyrethroid insecticides associated with ineffective field treatments has been increasingly reported in T. infestans from Argentina and Bolivia. There are few reports on the expression and causes of resistance in eggs of resistant populations, and even fewer studies on insecticide resistance throughout embryonic development. In this study, we explore the biochemical and molecular mechanisms potentially associated with the deltamethrin resistance assessed in the developing eggs of the Argentinean (Campo Largo) and Bolivian (Entre Ríos) T. infestans populations.We found measurable activity of monooxigenases and pyrethroid esterases throughout embryonic development. The pyrethroid esterase activity grew steadily throughout development in all the studied populations and was highest in eggs 12 d old. Mean enzyme activity increased from 13.6 to 16.3 and 22.2 picomol 7-hydroxycoumarin/min (7-OHC) in eggs of 4-, 7-, and 12 d old from the susceptible reference bug colony. Mean activity of resistant populations increased from 16.0 to 25.9 picomol 7-OHC/min in eggs of 4- to 12 d old in Entre Ríos population, and from 15.9 to 28.9 picomol 7-OHC/min in Campo Largo population. Molecular analysis of susceptible and resistant developing eggs detected L1014F mutation in both resistant populations, but no L925I mutation was found in any of the studied populations.Higher esterase activity and L1014F presence justify the resistance to pyrethroid throughout developing eggs of both studied T. infestans populations. The description of resistance profiles including resistance mechanisms involved will allow a rational design of campaigns for the control of Chagas disease transmission. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
Use of amphetamine-type stimulants in the Islamic Republic of Iran, 2004-2015: a review.
Shadloo, Behrang; Amin-Esmaeili, Masoumeh; Haft-Baradaran, Minoo; Noroozi, Alireza; Ghorban-Jahromi, Reza; Rahimi-Movaghar, Afarin
2017-05-01
Amphetamine-type stimulants (ATS) are the second most commonly used illicit drugs in the world, after cannabis. The production of ATS has increased worldwide, including in the Middle East. This review aims to assess ATS use in the Islamic Republic of Iran. PubMed, Scientific Information Database (a national database) and Iranian Center for Addiction Studies were searched. The review included studies on the general population, university and high school students, other specific populations, and drug users. The result show that self-reported methamphetamine and ecstasy use in 2016 was < 1% in the general population and university and high-school students, but the prevalence was higher in certain groups. There has also been an increase in the proportion of ATS users among clients of drug treatment centres. The findings highlight the need for high quality epidemiological studies and closer monitoring of stimulant use in different populations.
Trends in high-risk sexual behaviors among general population groups in China: a systematic review.
Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W N; de Vlas, Sake J
2013-01-01
The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population.
Trends in High-Risk Sexual Behaviors among General Population Groups in China: A Systematic Review
Cai, Rui; Richardus, Jan Hendrik; Looman, Caspar W. N.; de Vlas, Sake J.
2013-01-01
Background The objective of this review was to investigate whether Chinese population groups that do not belong to classical high risk groups show an increasing trend of engaging in high-risk sexual behaviors. Methods We systematically searched the English and Chinese literature on sexual risk behaviors published between January 1980 and March 2012 in PubMed and the China National Knowledge Infrastructure (CNKI). We included observational studies that focused on population groups other than commercial sex workers (CSWs) and their clients, and men who have sex with men (MSM) and quantitatively reported one of the following indicators of recent high-risk sexual behavior: premarital sex, commercial sex, multiple sex partners, condom use or sexually transmitted infections (STIs). We used generalized linear mixed model to examine the time trend in engaging in high-risk sexual behaviors. Results We included 174 observational studies involving 932,931 participants: 55 studies reported on floating populations, 73 on college students and 46 on other groups (i.e. out-of-school youth, rural residents, and subjects from gynecological or obstetric clinics and premarital check-up centers). From the generalized linear mixed model, no significant trends in engaging in high-risk sexual behaviors were identified in the three population groups. Discussion Sexual risk behaviors among certain general population groups have not increased substantially. These groups are therefore unlikely to incite a STI/HIV epidemic among the general Chinese population. Because the studied population groups are not necessarily representative of the general population, the outcomes found may not reflect those of the general population. PMID:24236121
Population limitation in a non-cyclic arctic fox population in a changing climate.
Pálsson, Snæbjörn; Hersteinsson, Páll; Unnsteinsdóttir, Ester R; Nielsen, Ólafur K
2016-04-01
Arctic foxes Vulpes lagopus (L.) display a sharp 3- to 5-year fluctuation in population size where lemmings are their main prey. In areas devoid of lemmings, such as Iceland, they do not experience short-term fluctuations. This study focusses on the population dynamics of the arctic fox in Iceland and how it is shaped by its main prey populations. Hunting statistics from 1958-2003 show that the population size of the arctic fox was at a maximum in the 1950s, declined to a minimum in the 1970s, and increased steadily until 2003. Analysis of the arctic fox population size and their prey populations suggests that fox numbers were limited by rock ptarmigan numbers during the decline period. The recovery of the arctic fox population was traced mostly to an increase in goose populations, and favourable climatic conditions as reflected by the Subpolar Gyre. These results underscore the flexibility of a generalist predator and its responses to shifting food resources and climate changes.
Asiki, Gershim; Baisley, Kathy; Kamali, Anatoli; Kaleebu, Pontiano; Seeley, Janet; Newton, Robert
2015-04-01
To characterise trends over time in smoking and alcohol consumption in a rural Ugandan population between 1994 and 2011. We used self-reported data from a long-standing population cohort - the General Population Cohort. From 1989 to 1999, the study population comprised about 10 000 residents of 15 adjacent villages. From 1999, 10 more villages were added, doubling the population. Among adults (≥13 years, who comprise about half of the total study population), data on smoking were collected in 1994/1995, 2008/2009 and in 2010/2011. Data on alcohol were collected in 1996/1997, 2000/2001, 2009/2010 and 2010/2011. The reported prevalence of smoking among men was 17% in 1994/1995, 14% in 2008/2009 and 16% in 2010/2011; equivalent figures for women were 1.5%, 1% and 2%. In the most recent time period, for both sexes combined, prevalence of smoking increased from 1.5% in those aged <29 years, to 18% in those 50+ years (P < 0.001); prevalence was 14.8% in the lowest tertile of socio-economic status, decreasing to 3.7% in the highest (P < 0.001). For alcohol consumption, current drinking was reported by 39% in 1996/1997, 35% in 2000/2001 and 28% in 2010/2011; men were more likely to drink than women (32.9% vs. 23.5% in 2010/2011) and consumption increased with age (P < 0.001); and was associated with low socio-economic status, riskier sexual behaviour and being HIV positive (P < 0.001). In this rural Ugandan population, consumption of cigarettes and alcohol is higher among men than women, increases with age and is more frequent among those with low socio-economic status. We find no evidence of increases in either exposure over time. © 2014 John Wiley & Sons Ltd.
Jeemon, Panniyammakal; Prabhakaran, Dorairaj; Goenka, Shifalika; Ramakrishnan, Lakshmy; Padmanabhan, Sandosh; Huffman, Mark; Joshi, Prashant; Sivasankaran, Sivasubramonian; Mohan, B V M; Ahmed, F; Ramanathan, Meera; Ahuja, R; Sinha, Nakul; Thankappan, K R; Reddy, K S
2012-04-01
Cardiovascular risk factors clustering associated with blood pressure (BP) has not been studied in the Indian population. This study was aimed at assessing the clustering effect of cardiovascular risk factors with suboptimal BP in Indian population as also the impact of risk reduction interventions. Data from 10543 individuals collected in a nation-wide surveillance programme in India were analysed. The burden of risk factors clustering with blood pressure and coronary heart disease (CHD) was assessed. The impact of a risk reduction programmme on risk factors clustering was prospectively studied in a sub-group. Mean age of participants was 40.9 ± 11.0 yr. A significant linear increase in number of risk factors with increasing blood pressure, irrespective of stratifying using different risk factor thresholds was observed. While hypertension occurred in isolation in 2.6 per cent of the total population, co-existence of hypertension and >3 risk factors was observed in 12.3 per cent population. A comprehensive risk reduction programme significantly reduced the mean number of additional risk factors in the intervention population across the blood pressure groups, while it continued to be high in the control arm without interventions (both within group and between group P<0.001). The proportion of 'low risk phenotype' increased from 13.4 to 19.9 per cent in the intervention population and it was decreased from 27.8 to 10.6 per cent in the control population (P<0.001). The proportion of individuals with hypertension and three more risk factors decreased from 10.6 to 4.7 per cent in the intervention arm while it was increased from 13.3 to 17.8 per cent in the control arm (P<0.001). Our findings showed that cardiovascular risk factors clustered together with elevated blood pressure and a risk reduction programme significantly reduced the risk factors burden.
Logsetty, Sarvesh; Shamlou, Amir; Gawaziuk, Justin P; March, Justin; Doupe, Malcolm; Chateau, Dan; Hoppensack, Mike; Khan, Sazzadul; Medved, Maria; Leslie, William D; Enns, Murray W; Stein, Murray B; Asmundson, Gordon J G; Sareen, Jitender
2016-06-01
This study investigates the increased risk of mental health outcomes and health care utilization associated with burn with two year of follow-up using a longitudinal population-based matched cohort design. Adult burn survivors (n=157) were identified from a provincial burn registry and matched 1:5 with non-burn control subjects from the general population (matching variables age and gender). The prevalence of mental health outcomes and the rates of health care utilization between the groups were compared for the 2years pre and post index date using anonymously linked population-based administrative health care data. Rates were adjusted for age, gender and sociodemographic characteristics. While the burn cohort had an increased prevalence of mental health problems after burn compared to the control cohort, the burn group also had an increased prevalence of pre-burn depression (16.6% vs 7.8%; p=0.0005) and substance use disorders (8.9% vs 3.2%; p=0.001) when compared to controls. Once the pre-existing prevalence of mental illness was taken into account there was no significant change in the prevalence of mental health problems when comparing the burn group to controls over time. Although burns may not increase rates of mental health issues and health care utilization, burn survivors are a vulnerable group who already demonstrate increased rates of psychopathology and need for care. The present study highlights the importance of assessment and treatment of mental health outcomes in this population. Copyright © 2016 Elsevier Ltd and ISBI. All rights reserved.
Demographic history of an English coal-mining parish: Houghton-le-Spring, County Durham, 1660-1820
DOE Office of Scientific and Technical Information (OSTI.GOV)
Peck, T.R.
In 1666 the size of the population of Houghton-le-Spring was 2332. By 1821, the population had grown to 12,889 persons. The population of the village grew primarily due to increasing fertility during the period. The Total Martial Fertility Ratio (20-49) increased from 6.98 to 8.37 between the late seventeenth and the early nineteenth centuries. The mean age at first marriage for brides and grooms declined on average by three years. During the 160 years of the study the level of mortality actually increased. In the parish of Houghton-le-Spring, the coal miners, who were prime examples of proletarians, did marry muchmore » younger than a person engaged in the traditional occupations. Thus, the primary cause of the increasing level of fertility in the parish was the process of proletarianization. The study of mortality revealed that coal miners and their dependents suffered higher rates of mortality than persons in other occupations. These higher rates were partly caused by a greater incidence of deaths due to mining accidents. The population proved to be surprisingly immobile. Approximately 90% of the population lived their entire life within fifteen miles of their place of birth. This was true of all occupational groups.« less
Struchiner, Claudio Jose; Rocklöv, Joacim; Wilder-Smith, Annelies; Massad, Eduardo
2015-01-01
In Singapore, the frequency and magnitude of dengue epidemics have increased significantly over the past 40 years. It is important to understand the main drivers for the rapid increase in dengue incidence. We studied the relative contributions of putative drivers for the rise of dengue in Singapore: population growth, climate parameters and international air passenger arrivals from dengue endemic countries, for the time period of 1974 until 2011. We used multivariable Poisson regression models with the following predictors: Annual Population Size; Aedes Premises Index; Mean Annual Temperature; Minimum and Maximum Temperature Recorded in each year; Annual Precipitation and Annual Number of Air Passengers arriving from dengue-endemic South-East Asia to Singapore. The relative risk (RR) of the increase in dengue incidence due to population growth over the study period was 42.7, while the climate variables (mean and minimum temperature) together explained an RR of 7.1 (RR defined as risk at the end of the time period relative to the beginning and goodness of fit associated with the model leading to these estimates assessed by pseudo-R2 equal to 0.83). Estimating the extent of the contribution of these individual factors on the increasing dengue incidence, we found that population growth contributed to 86% while the residual 14% was explained by increase in temperature. We found no correlation with incoming air passenger arrivals into Singapore from dengue endemic countries. Our findings have significant implications for predicting future trends of the dengue epidemics given the rapid urbanization with population growth in many dengue endemic countries. It is time for policy-makers and the scientific community alike to pay more attention to the negative impact of urbanization and urban climate on diseases such as dengue. PMID:26322517
Struchiner, Claudio Jose; Rocklöv, Joacim; Wilder-Smith, Annelies; Massad, Eduardo
2015-01-01
In Singapore, the frequency and magnitude of dengue epidemics have increased significantly over the past 40 years. It is important to understand the main drivers for the rapid increase in dengue incidence. We studied the relative contributions of putative drivers for the rise of dengue in Singapore: population growth, climate parameters and international air passenger arrivals from dengue endemic countries, for the time period of 1974 until 2011. We used multivariable Poisson regression models with the following predictors: Annual Population Size; Aedes Premises Index; Mean Annual Temperature; Minimum and Maximum Temperature Recorded in each year; Annual Precipitation and Annual Number of Air Passengers arriving from dengue-endemic South-East Asia to Singapore. The relative risk (RR) of the increase in dengue incidence due to population growth over the study period was 42.7, while the climate variables (mean and minimum temperature) together explained an RR of 7.1 (RR defined as risk at the end of the time period relative to the beginning and goodness of fit associated with the model leading to these estimates assessed by pseudo-R2 equal to 0.83). Estimating the extent of the contribution of these individual factors on the increasing dengue incidence, we found that population growth contributed to 86% while the residual 14% was explained by increase in temperature. We found no correlation with incoming air passenger arrivals into Singapore from dengue endemic countries. Our findings have significant implications for predicting future trends of the dengue epidemics given the rapid urbanization with population growth in many dengue endemic countries. It is time for policy-makers and the scientific community alike to pay more attention to the negative impact of urbanization and urban climate on diseases such as dengue.
de Pedro-Cuesta, Jesús; Virués-Ortega, Javier; Vega, Saturio; Seijo-Martínez, Manuel; Saz, Pedro; Rodríguez, Fernanda; Rodríguez-Laso, Angel; Reñé, Ramón; de las Heras, Susana Pérez; Mateos, Raimundo; Martínez-Martín, Pablo; Manubens, José María; Mahillo-Fernandez, Ignacio; López-Pousa, Secundino; Lobo, Antonio; Reglà, Jordi Llinàs; Gascón, Jordi; García, Francisco José; Fernández-Martínez, Manuel; Boix, Raquel; Bermejo-Pareja, Félix; Bergareche, Alberto; Benito-León, Julián; de Arce, Ana; del Barrio, José Luis
2009-01-01
Background This study describes the prevalence of dementia and major dementia subtypes in Spanish elderly. Methods We identified screening surveys, both published and unpublished, in Spanish populations, which fulfilled specific quality criteria and targeted prevalence of dementia in populations aged 70 years and above. Surveys covering 13 geographically different populations were selected (prevalence period: 1990-2008). Authors of original surveys provided methodological details of their studies through a systematic questionnaire and also raw age-specific data. Prevalence data were compared using direct adjustment and logistic regression. Results The reanalyzed study population (aged 70 year and above) was composed of Central and North-Eastern Spanish sub-populations obtained from 9 surveys and totaled 12,232 persons and 1,194 cases of dementia (707 of Alzheimer's disease, 238 of vascular dementia). Results showed high variation in age- and sex-specific prevalence across studies. The reanalyzed prevalence of dementia was significantly higher in women; increased with age, particularly for Alzheimer's disease; and displayed a significant geographical variation among men. Prevalence was lowest in surveys reporting participation below 85%, studies referred to urban-mixed populations and populations diagnosed by psychiatrists. Conclusion Prevalence of dementia and Alzheimer's disease in Central and North-Eastern Spain is higher in females, increases with age, and displays considerable geographic variation that may be method-related. People suffering from dementia and Alzheimer's disease in Spain may approach 600,000 and 400,000 respectively. However, existing studies may not be completely appropriate to infer prevalence of dementia and its subtypes in Spain until surveys in Southern Spain are conducted. PMID:19840375
Pleasants, John M.; Zalucki, Myron P.; Oberhauser, Karen S.; Brower, Lincoln P.; Taylor, Orley R.; Thogmartin, Wayne E.
2017-01-01
To assess the change in the size of the eastern North American monarch butterfly summer population, studies have used long-term data sets of counts of adult butterflies or eggs per milkweed stem. Despite the observed decline in the monarch population as measured at overwintering sites in Mexico, these studies found no decline in summer counts in the Midwest, the core of the summer breeding range, leading to a suggestion that the cause of the monarch population decline is not the loss of Midwest agricultural milkweeds but increased mortality during the fall migration. Using these counts to estimate population size, however, does not account for the shift of monarch activity from agricultural fields to non-agricultural sites over the past 20 years, as a result of the loss of agricultural milkweeds due to the near-ubiquitous use of glyphosate herbicides. We present the counter-hypotheses that the proportion of the monarch population present in non-agricultural habitats, where counts are made, has increased and that counts reflect both population size and the proportion of the population observed. We use data on the historical change in the proportion of milkweeds, and thus monarch activity, in agricultural fields and non-agricultural habitats to show why using counts can produce misleading conclusions about population size. We then separate out the shifting proportion effect from the counts to estimate the population size and show that these corrected summer monarch counts show a decline over time and are correlated with the size of the overwintering population. In addition, we present evidence against the hypothesis of increased mortality during migration. The milkweed limitation hypothesis for monarch decline remains supported and conservation efforts focusing on adding milkweeds to the landscape in the summer breeding region have a sound scientific basis.
Pleasants, John M; Zalucki, Myron P; Oberhauser, Karen S; Brower, Lincoln P; Taylor, Orley R; Thogmartin, Wayne E
2017-01-01
To assess the change in the size of the eastern North American monarch butterfly summer population, studies have used long-term data sets of counts of adult butterflies or eggs per milkweed stem. Despite the observed decline in the monarch population as measured at overwintering sites in Mexico, these studies found no decline in summer counts in the Midwest, the core of the summer breeding range, leading to a suggestion that the cause of the monarch population decline is not the loss of Midwest agricultural milkweeds but increased mortality during the fall migration. Using these counts to estimate population size, however, does not account for the shift of monarch activity from agricultural fields to non-agricultural sites over the past 20 years, as a result of the loss of agricultural milkweeds due to the near-ubiquitous use of glyphosate herbicides. We present the counter-hypotheses that the proportion of the monarch population present in non-agricultural habitats, where counts are made, has increased and that counts reflect both population size and the proportion of the population observed. We use data on the historical change in the proportion of milkweeds, and thus monarch activity, in agricultural fields and non-agricultural habitats to show why using counts can produce misleading conclusions about population size. We then separate out the shifting proportion effect from the counts to estimate the population size and show that these corrected summer monarch counts show a decline over time and are correlated with the size of the overwintering population. In addition, we present evidence against the hypothesis of increased mortality during migration. The milkweed limitation hypothesis for monarch decline remains supported and conservation efforts focusing on adding milkweeds to the landscape in the summer breeding region have a sound scientific basis.
Khomenko, I M; Zakladna, N V; Orlova, N M
2017-12-01
To evaluate the health status of adult population living in the Ukrainian nuclear power industry obser vation zone on the example of Zaporizhzhia Nuclear Power Plant. System review, analytic, sociological survey and statistical methods. There was established an increase in the incidence of digestive diseases among adult population in Nikopol of Dnipropetrovsk region, which is included in the Zaporizhzhia NPP observation zone. The highest increase was observed in the incidence of peptic ulcer, gastritis and duodenitis, cholecystitis and cholangitis by 340 %, 305 % and 83 %, respectively. In connection with the residence in industrially developed region and NPP life extension in Ukraine, the possible influence of harmful factors on health status of the population of observation zones, an increase in the incidence of digestive diseases among adult population, there is required continuous monitoring and detailed study of public health. I. M. Khomenko, N. V. Zakladna, N. M. Orlova.
Bosch de Basea, Magda; Salotti, Jane A; Pearce, Mark S; Muchart, Jordi; Riera, Luis; Barber, Ignasi; Pedraza, Salvador; Pardina, Marina; Capdevila, Antoni; Espinosa, Ana; Cardis, Elisabeth
2016-01-01
Although there are undeniable diagnostic benefits of CT scanning, its increasing use in paediatric radiology has become a topic of concern regarding patient radioprotection. To assess the rate of CT scanning in Catalonia, Spain, among patients younger than 21 years old at the scan time. This is a sub-study of a larger international cohort study (EPI-CT, the International pediatric CT scan study). Data were retrieved from the radiological information systems (RIS) of eight hospitals in Catalonia since the implementation of digital registration (between 1991 and 2010) until 2013. The absolute number of CT scans annually increased 4.5% between 1991 and 2013, which was less accentuated when RIS was implemented in most hospitals. Because the population attending the hospitals also increased, however, the rate of scanned patients changed little (8.3 to 9.4 per 1,000 population). The proportions of patients with more than one CT and more than three CTs showed a 1.51- and 2.7-fold increase, respectively, over the 23 years. Gradual increases in numbers of examinations and scanned patients were observed in Catalonia, potentially explained by new CT scanning indications and increases in the availability of scanners, the number of scans per patient and the size of the attended population.
Ningal, Tine; Hartemink, A E; Bregt, A K
2008-04-01
The relation between human population growth and land use change is much debated. Here we present a case study from Papua New Guinea where the population has increased from 2.3 million in 1975 to 5.2 million in 2000. Since 85% of the population relies on subsistence agriculture, population growth affects agricultural land use. We assessed land use change in the Morobe province (33,933 km2) using topographic maps of 1975 and Landsat TM images of 1990 and 2000. Between 1975 and 2000, agricultural land use increased by 58% and population grew by 99%. Most new agricultural land was taken from primary forest and the forest area decreased from 9.8 ha person(-1) in 1975 to 4.4 ha person(-1) in 2000. Total population change and total land use change were strongly correlated. Most of the agricultural land use change occurred on Inceptisols in areas with high rainfall (>2500 mm year(-1)) on moderate to very steep slopes (10-56%). Agricultural land use changes in logged-over areas were in the vicinity of populated places (villages), and in close proximity to road access. There was considerable variation between the districts but districts with higher population growth also had larger increases in agricultural areas. It is concluded that in the absence of improved farming systems the current trend of increased agriculture with rapid population growth is likely to continue.
Hansen, Ann-Brit E; Gerstoft, Jan; Kronborg, Gitte; Larsen, Carsten S; Pedersen, Court; Pedersen, Gitte; Obel, Niels
2012-01-28
To compare fracture risk in persons with and without HIV infection and to examine the influence of highly active antiretroviral therapy (HAART) initiation on risk of fracture. Population-based nationwide cohort study using Danish registries. Outcome measures were time to first fracture at any site, time to first low-energy and high-energy fracture in HIV-infected patients (n = 5306) compared with a general population control cohort (n = 26 530) matched by sex and age during the study period 1995-2009. Cox regression analyses were used to estimate incidence rate ratios (IRRs). HIV-infected patients had increased risk of fracture [IRR 1.5, 95% confidence interval (CI) 1.4-1.7] compared with population controls. The relative risk was lower in HIV-monoinfected patients (IRR 1.3, 95% CI 1.2-1.4) than in HIV/hepatitis C virus (HCV)-coinfected patients (IRR 2.9, 95% CI 2.5-3.4).Both HIV-monoinfected and HIV/HCV-coinfected patients had increased risk of low-energy fracture, IRR of 1.6 (95% CI 1.4-1.8) and 3.8 (95% CI 3.0-4.9). However, only HIV/HCV-coinfected patients had increased risk of high-energy fracture, IRR of 2.4 (95% CI 2.0-2.9). Among HIV-monoinfected patients the risk of low-energy fracture was only significantly increased after HAART exposure, IRR of 1.8 (95% CI 1.5-2.1). The increased risk in HAART-exposed patients was not associated with CD4 cell count, prior AIDS, tenofovir or efavirenz exposure, but with comorbidity and smoking. HIV-infected patients had increased risk of fracture compared with population controls. Among HIV-monoinfected patients the increased risk was observed for low-energy but not for high-energy fractures, and the increased risk of low-energy fracture was only observed in HAART-exposed patients.
Do prescription stimulants increase the risk of adverse cardiovascular events?: A systematic review
2012-01-01
Background There is increasing concern that prescription stimulants may be associated with adverse cardiovascular events such as stroke, myocardial infarction, and sudden death. Public health concerns are amplified by increasing use of prescription stimulants among adults. Methods The objective of this study was to conduct a systematic review of the evidence of an association between prescription stimulant use and adverse cardiovascular outcomes. PUBMED, MEDLINE, EMBASE and Google Scholar searches were conducted using key words related to these topics (MESH): ADHD; Adults; Amphetamine; Amphetamines; Arrhythmias, Cardiac; Cardiovascular Diseases; Cardiovascular System; Central Nervous Stimulants; Cerebrovascular; Cohort Studies; Case–control Studies; Death; Death, Sudden, Cardiac; Dextroamphetamine; Drug Toxicity; Methamphetamine; Methylphenidate; Myocardial Infarction; Stimulant; Stroke; Safety. Eligible studies were population-based studies of children, adolescents, or adults using prescription stimulant use as the independent variable and a hard cardiovascular outcome as the dependent variable. Results Ten population-based observational studies which evaluated prescription stimulant use with cardiovascular outcomes were reviewed. Six out of seven studies in children and adolescents did not show an association between stimulant use and adverse cardiovascular outcomes. In contrast, two out of three studies in adults found an association. Conclusions Findings of an association between prescription stimulant use and adverse cardiovascular outcomes are mixed. Studies of children and adolescents suggest that statistical power is limited in available study populations, and the absolute risk of an event is low. More suggestive of a safety signal, studies of adults found an increased risk for transient ischemic attack and sudden death/ventricular arrhythmia. Interpretation was limited due to differences in population, cardiovascular outcome selection/ascertainment, and methodology. Accounting for confounding and selection biases in these studies is of particular concern. Future studies should address this and other methodological issues. PMID:22682429
Ram, R
1984-04-01
The relationship between population increase, economic growth, education and income inequality was examined in a cross-section study based on data from 26 developing and 2 developed countries. As other studies have noted, high population growth is associated with a less equal income distribution. A 1 percentage point reduction in the rate of population growth tends to raise the income share of the poorest 80% in the less developed world by almost 5 percentage points and is associated with a 1.7 percentage point increase in the income share of the poorest 40%. The relationship between short-run income growth and equality, on the other hand, is strong and positive. Estimates suggest that a 1 percentage point increase in the short-run rate of growth of the gross domestic product (GDP) increases the income share of the bottom 80% by about 2 percentage points and that of the poorest 40% by almost 1 percentage point. Although higher mean schooling appears to be a mild equalizer, educational inequality does not appear to have an adverse effect on income distribution. Overall, these results challenge the widely held belief that there must be a growth-equity trade-off. Moreover, they suggest that the impact of educational inequality on income distribution may be different from that observed in earlier studies, implying a need for caution in using these earlier results as a basis for educational policy development.
Morioka, Travis Y; Bolin, Jeremy T; Attipoe, Selasi; Jones, Donnamaria R; Stephens, Mark B; Deuster, Patricia A
2015-07-01
Although prior studies have examined the prevalence of dietary supplement use among various populations, data on single vitamins prescribed by health care providers are limited. This study examined trends in single-vitamin supplement (A, C, D, E, K) prescriptions by providers from military treatment facilities from 2007 to 2011. We examined prescription data from the Department of Defense Pharmacy Data Transaction Service to determine trends in the aforementioned single-vitamin supplement prescriptions. Prescription rates per 1,000 active duty personnel were estimated using population data retrieved from the Defense Medical Epidemiology Database (i.e., [number of prescriptions/population size] × 1,000). Across the 5-year period, the number of vitamin D prescriptions per 1,000 active duty personnel increased 454%. In contrast, the number of vitamin A, vitamin E, and vitamin K prescriptions per 1,000 active duty personnel decreased by 32%, 53%, and 29% respectively. Vitamin C prescriptions remained relatively constant. Across all age groups, total single-vitamin supplement prescriptions increased by 180%. Together, prescriptions examined in this study increased steadily from 2007 to 2011, primarily because of the increase in vitamin D prescriptions. The exhibited trend reflects the current general-population pattern of dietary supplement use, with large increases in vitamin D and declines in vitamin E. Reprint & Copyright © 2015 Association of Military Surgeons of the U.S.
Ramo, Cristina; Amat, Juan A; Nilsson, Leif; Schricke, Vincent; Rodríguez-Alonso, Mariano; Gómez-Crespo, Enrique; Jubete, Fernando; Navedo, Juan G; Masero, José A; Palacios, Jesús; Boos, Mathieu; Green, Andy J
2015-01-01
The unusually high quality of census data for large waterbirds in Europe facilitates the study of how population change varies across a broad geographical range and relates to global change. The wintering population of the greylag goose Anser anser in the Atlantic flyway spanning between Sweden and Spain has increased from 120 000 to 610 000 individuals over the past three decades, and expanded its wintering range northwards. Although population sizes recorded in January have increased in all seven countries in the wintering range, we found a pronounced northwards latitudinal effect in which the rate of increase is higher at greater latitudes, causing a constant shift in the centre of gravity for the spatial distribution of wintering geese. Local winter temperatures have a strong influence on goose numbers but in a manner that is also dependent on latitude, with the partial effect of temperature (while controlling for the increasing population trend between years) being negative at the south end and positive at the north end of the flyway. Contrary to assumptions in the literature, the expansion of crops exploited by greylag geese has made little contribution to the increases in population size. Only in one case (expansion of winter cereals in Denmark) did we find evidence of an effect of changing land use. The expanding and shifting greylag population is likely to have increasing impacts on habitats in northern Europe during the course of this century.
Linking vital rates to invasiveness of a perennial herb.
Ramula, Satu
2014-04-01
Invaders generally show better individual performance than non-invaders and, therefore, vital rates (survival, growth, fecundity) could potentially be used to predict species invasiveness outside their native range. Comparative studies have usually correlated vital rates with the invasiveness status of species, while few studies have investigated them in relation to population growth rate. Here, I examined the influence of five vital rates (plant establishment, survival, growth, flowering probability, seed production) and their variability (across geographic regions, habitat types, population sizes and population densities) on population growth rate (λ) using data from 37 populations of an invasive, iteroparous herb (Lupinus polyphyllus) in a part of its invaded range in Finland. Variation in vital rates was often related to habitat type and population density. The performance of the populations varied from declining to rapidly increasing independently of habitat type, population size or population density, but differed between regions. The population growth rate increased linearly with plant establishment, and with the survival and growth of vegetative individuals, while the survival of flowering individuals and annual seed production were not related to λ. The vital rates responsible for rapid population growth varied among populations. These findings highlight the importance of both regional and local conditions to plant population dynamics, demonstrating that individual vital rates do not necessarily correlate with λ. Therefore, to understand the role of individual vital rates in a species ability to invade, it is necessary to quantify their effect on population growth rate.
Epidemiological evidence for a health risk from mobile phone base stations.
Khurana, Vini G; Hardell, Lennart; Everaert, Joris; Bortkiewicz, Alicja; Carlberg, Michael; Ahonen, Mikko
2010-01-01
Human populations are increasingly exposed to microwave/radiofrequency (RF) emissions from wireless communication technology, including mobile phones and their base stations. By searching PubMed, we identified a total of 10 epidemiological studies that assessed for putative health effects of mobile phone base stations. Seven of these studies explored the association between base station proximity and neurobehavioral effects and three investigated cancer. We found that eight of the 10 studies reported increased prevalence of adverse neurobehavioral symptoms or cancer in populations living at distances < 500 meters from base stations. None of the studies reported exposure above accepted international guidelines, suggesting that current guidelines may be inadequate in protecting the health of human populations. We believe that comprehensive epidemiological studies of long-term mobile phone base station exposure are urgently required to more definitively understand its health impact.
Walsh, Michael G; Haseeb, Ma
2015-01-01
Ebola virus disease (EVD) is an emerging infectious disease of zoonotic origin that has been responsible for high mortality and significant social disruption in West and Central Africa. Zoonotic transmission of EVD requires contact between susceptible human hosts and the reservoir species for Ebolaviruses, which are believed to be fruit bats. Nevertheless, features of the landscape that may facilitate such points of contact have not yet been adequately identified. Nor have spatial dependencies between zoonotic EVD transmission and landscape structures been delineated. This investigation sought to describe the spatial relationship between zoonotic EVD transmission events, or spillovers, and population density and vegetation cover. An inhomogeneous Poisson process model was fitted to all precisely geolocated zoonotic transmissions of EVD in West and Central Africa. Population density was strongly associated with spillover; however, there was significant interaction between population density and green vegetation cover. In areas of very low population density, increasing vegetation cover was associated with a decrease in risk of zoonotic transmission, but as population density increased in a given area, increasing vegetation cover was associated with increased risk of zoonotic transmission. This study showed that the spatial dependencies of Ebolavirus spillover were associated with the distribution of population density and vegetation cover in the landscape, even after controlling for climate and altitude. While this is an observational study, and thus precludes direct causal inference, the findings do highlight areas that may be at risk for zoonotic EVD transmission based on the spatial configuration of important features of the landscape.
Aoyama, T; Hirata, K; Yamamoto, Y; Yokota, H; Hayashi, H; Aoyama, Y; Matsumoto, Y
2016-08-01
Midazolam (MDZ) is commonly used for sedating critically ill patients. The daily dose required for adequate sedation increases in increments over 100 h after administration. The objectives of this study were to characterize the MDZ pharmacokinetics in critically ill patients and to describe the phenomenon of increasing daily dose by means of population pharmacokinetic analysis. Data were obtained from 30 patients treated in an intensive care unit. The patients received MDZ intravenously as a combination of bolus and continuous infusion. Serum MDZ concentration was assayed by high-performance liquid chromatography. Population pharmacokinetic analysis was performed using the NONMEM software package. The alteration of clearance unexplained by demographic factors and clinical laboratory data was described as an autoinduction of MDZ clearance using a semi-mechanistic pharmacokinetic-enzyme turnover model. The final population pharmacokinetic model was a one-compartment model estimated by incorporating a semi-mechanistic pharmacokinetic-enzyme turnover model for clearance, taking autoinduction into account. A significant covariate for MDZ clearance was total bilirubin. An increase in total bilirubin indicated a reduction in MDZ clearance. From simulation using the population pharmacokinetic parameters obtained in this study, MDZ clearance increased 2·3 times compared with pre-induced clearance 100 h after the start of 12·5 mg/h continuous infusion. Autoinduction and total bilirubin were significant predictors of the clearance of MDZ in this population. Step-by-step dosage adjustment using this population pharmacokinetic model may be useful for establishing a MDZ dosage regimen in critically ill patients. © 2016 John Wiley & Sons Ltd.
Soft drinks consumption, diet quality and BMI in a Mediterranean population.
Balcells, Eva; Delgado-Noguera, Mario; Pardo-Lozano, Ricardo; Roig-González, Taïs; Renom, Anna; González-Zobl, Griselda; Muñoz-Ortego, Juan; Valiente-Hernández, Susana; Pou-Chaubron, Marina; Schröder, Helmut
2011-05-01
Evidence of the effects of soft drinks consumption on BMI and lifestyle in adult populations is mixed and quite limited. The aim of the present study was to determine the association of soft drinks consumption with BMI and lifestyle in a representative Mediterranean population. Two independent, population-based, cross-sectional (2000 and 2005) studies. Dietary intake was assessed using a validated FFQ. Weight and height were measured. Girona, Spain. Random sample of the 35- to 74-year-old population (3910 men and 4285 women). Less than half (41·7%) of the population consumed soft drinks; the mean consumption was 36·2 ml/d. The prevalence of sedentary lifestyle increased with the frequency of soft drinks consumption (P = 0·025). Daily soft drinks consumption significantly increased the risk of low adherence to the Mediterranean diet (OR = 0·57, 95% CI 0·44, 0·74 v. top tertile of Mediterranean diet score). Multiple linear regression analyses, controlled for potential confounders, revealed that an increment in soft drinks consumption of 100 ml was associated with a 0·21 kg/m² increase in BMI (P = 0·001). Only implausibly low reports of energy consumption showed a null association between soft drinks consumption and BMI. Soft drinks consumption was not embedded in a healthy diet context and was positively associated with BMI and sedentary lifestyle in this Mediterranean population.
Moradi-Lakeh, Maziar; Forouzanfar, Mohammad Hossein; El Bcheraoui, Charbel; Daoud, Farah; Afshin, Ashkan; Hanson, Sarah Wulf; Vos, Theo; Naghavi, Mohsen; Murray, Christopher J L; Mokdad, Ali H
2017-01-01
The prevalence of diabetes in the Eastern Mediterranean Region (EMR) is among the highest in the world. We used findings from the Global Burden of Disease 2013 study to calculate the burden of diabetes in the EMR. The burden of diabetes and burden attributable to high fasting plasma glucose (HFPG) were calculated for each of the 22 countries in the EMR between 1990 and 2013. A systematic analysis was performed on mortality and morbidity data to estimate prevalence, deaths, and disability-adjusted life years (DALYs). The diabetes death rate increased by 60.7%, from 12.1 per 100,000 population (95% uncertainty interval [UI]: 11.2-13.2) in 1990 to 19.5 per 100,000 population (95% UI: 17.4-21.5) in 2013. The diabetes DALY rate increased from 589.9 per 100,000 (95% UI: 498.0-698.0) in 1990 to 883.5 per 100,000 population (95% UI: 732.2-1,051.5) in 2013. In 2013, HFPG accounted for 4.9% (95% UI: 4.4-5.3) of DALYs from all causes. Total DALYs from diabetes increased by 148.6% during 1990-2013; population growth accounted for a 62.9% increase, and aging and increase in age-specific DALY rates accounted for 31.8% and 53.9%, respectively. Our findings show that diabetes causes a major burden in the EMR, which is increasing. Aging and population growth do not fully explain this increase in the diabetes burden. Programs and policies are urgently needed to reduce risk factors for diabetes, increase awareness of the disease, and improve diagnosis and control of diabetes to reduce its burden. © 2017 by the American Diabetes Association.
What Works to Increase the Use of Research in Population Health Policy and Programmes: A Review
ERIC Educational Resources Information Center
Moore, Gabriel; Redman, Sally; Haines, Mary; Todd, Angela
2011-01-01
Policy agencies are implementing strategies to increase the use of research in policy decisions. This paper examines the evidence about the effectiveness of these strategies. We conducted an extensive search focused on population health policy and programmes. We classified 106 papers meeting study criteria into research type (conceptual,…
Falls and Fall Prevention in Older Adults With Early-Stage Dementia: An Integrative Review.
Lach, Helen W; Harrison, Barbara E; Phongphanngam, Sutthida
2017-05-01
Older adults with mild cognitive impairment (MCI) and early-stage dementia have an increased risk of falling, with risks to their health and quality of life. The purpose of the current integrative review was to evaluate evidence on fall risk and fall prevention in this population. Studies were included if they examined falls or fall risk factors in older adults with MCI or early-stage dementia, or reported interventions in this population; 40 studies met criteria. Evidence supports the increased risk of falls in individuals even in the early stages of dementia or MCI, and changes in gait, balance, and fear of falling that may be related to this increased fall risk. Interventions included exercise and multifactorial interventions that demonstrated some potential to reduce falls in this population. Few studies had strong designs to provide evidence for recommendations. Further study in this area is warranted. [Res Gerontol Nurs. 2017; 10(03):139-148.]. Copyright 2016, SLACK Incorporated.
Patterns and Correlates of Research Productivity in Population Scientists.
ERIC Educational Resources Information Center
Richards, James M., Jr.
Although a concern with population issues has gone out of fashion, the problems underlying that concern have not disappeared. Solving these problems would be facilitated by increased knowledge produced by scientists working directly on population issues. A study was conducted to explore patterns and correlates of research productivity of members…
Rapid cycling genomic selection in a multiparental tropical maize population
USDA-ARS?s Scientific Manuscript database
Genomic selection (GS) increases genetic gain by reducing the length of the selection cycle, as has been exemplified in maize using rapid cycling recombination of biparental populations. However, no results of GS applied to maize multi-parental populations have been reported so far. This study is th...
Genomics of a revived breed: Case study of the Belgian campine cattle
Wijnrocx, Katrien; Colinet, Frédéric G.; Gengler, Nicolas; Hulsegge, Bettine; Windig, Jack J.; Buys, Nadine
2017-01-01
Through centuries of both natural and artificial selection, a variety of local cattle populations arose with highly specific phenotypes. However, the intensification and expansion of scale in animal production systems led to the predominance of a few highly productive cattle breeds. The loss of local populations is often considered irreversible and with them specific qualities and rare variants could be lost as well. Over these last years, the interest in these local breeds has increased again leading to increasing efforts to conserve these breeds or even revive lost populations, e.g. through the use of crosses with similar breeds. However, the remaining populations are expected to contain crossbred individuals resulting from introgressions. They are likely to carry exogenous genes that affect the breed’s authenticity on a genomic level. Using the revived Campine breed as a case study, 289 individuals registered as purebreds were genotyped on the Illumina BovineSNP50. In addition, genomic information on the Illumina BovineHD and Illumina BovineSNP50 of ten breeds was available to assess the current population structure, genetic diversity, and introgression with phenotypically similar and/or historically related breeds. Introgression with Holstein and beef cattle genotypes was limited to only a few farms. While the current population shows a substantial amount of within-breed variation, the majority of genotypes can be separated from other breeds in the study, supporting the re-establishment of the Campine breed. The majority of the population is genetically close to the Deep Red (NL), Improved Red (NL) and Eastern Belgium Red and White (BE) cattle, breeds known for their historical ties to the Campine breed. This would support an open herdbook policy, thereby increasing the population size and consequently providing a more secure future for the breed. PMID:28426822
Colorectal cancer screening in high-risk groups is increasing, although current smokers fall behind.
Oluyemi, Aminat O; Welch, Amy R; Yoo, Lisa J; Lehman, Erik B; McGarrity, Thomas J; Chuang, Cynthia H
2014-07-15
There is limited information about colorectal cancer (CRC) screening trends in high-risk groups, including the black, obese, diabetic, and smoking populations. For this study, the authors evaluated national CRC screening trends in these high-risk groups to provide insights into whether screening resources are being appropriately used. This was a nationally representative, population-based study using the Behavioral Risk Factor Surveillance System from the Centers for Disease Control. Data analysis was performed using bivariate analyses with weighted logistic regression. In the general population, CRC screening increased significantly from 59% to 65% during the years 2006 to 2010. The screening prevalence in non-Hispanic blacks was 58% in 2006 and 65% in 2010. Among obese individuals, the prevalence of up-to-date CRC screening increased significantly from 59% in 2006 to 66% in 2010. Screening prevalence in individuals with diabetes was 63% in 2006 and 69% in 2010. The CRC screening prevalence in current smokers was 45% in 2006 and 50% in 2010. The odds of CRC screening in the non-Hispanic black population, the obese population, and the diabetic population were higher than in non-Hispanic whites, normal weight individuals, and the population without diabetes, respectively. Current smokers had significantly lower odds of CRC screening than never-smokers in the years studied (2006: odds ratio [OR], 0.71; 95% confidence interval [CI], 0.66-0.76; 2008: OR, 0.67; 95% CI, 0.63-0.71; 2010: OR, 0.69; 95% CI, 0.66-0.73). The prevalence of CRC screening in high-risk groups is trending upward. Despite this, current smokers have significantly lower odds of CRC screening compared with the general population. © 2014 American Cancer Society.
Hong, A Ram; Lim, Soo
2015-09-01
Metabolic syndrome is referred to as syndrome X or insulin resistance syndrome, and is primarily composed of abdominal obesity, diabetes, glucose intolerance, dyslipidemia and high blood pressure. Asians have a lower frequency of obesity than Caucasians, but have an increasing tendency toward metabolic syndrome. Thus, metabolic syndrome poses a major challenge for public health professionals, and is set to become a social and economic problem in Asian populations. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. Recently, several studies were carried out on a large scale that represents the general Korean population. The prevalence of metabolic syndrome in Korean adults has varied depending on the study designs and different criteria, but shows a distinct increasing trend of metabolic syndrome driven by an increase in abdominal obesity and dyslipidemia. Given the rapid economic progression of Korea over the past 30 years along with a rise of the aged population, it is expected that the prevalence of metabolic syndrome will further increase. Therefore, a proactive strategy at the governmental level for metabolic syndrome prevention should be implemented, reducing abdominal obesity and dyslipidemia. Healthy dietary habits and regular exercise should be emphasized as a part of such a strategy.
Hong, A Ram; Lim, Soo
2015-01-01
Metabolic syndrome is referred to as syndrome X or insulin resistance syndrome, and is primarily composed of abdominal obesity, diabetes, glucose intolerance, dyslipidemia and high blood pressure. Asians have a lower frequency of obesity than Caucasians, but have an increasing tendency toward metabolic syndrome. Thus, metabolic syndrome poses a major challenge for public health professionals, and is set to become a social and economic problem in Asian populations. Most data on metabolic syndrome are based on studies from Western countries with only limited information derived from Asian populations. Recently, several studies were carried out on a large scale that represents the general Korean population. The prevalence of metabolic syndrome in Korean adults has varied depending on the study designs and different criteria, but shows a distinct increasing trend of metabolic syndrome driven by an increase in abdominal obesity and dyslipidemia. Given the rapid economic progression of Korea over the past 30 years along with a rise of the aged population, it is expected that the prevalence of metabolic syndrome will further increase. Therefore, a proactive strategy at the governmental level for metabolic syndrome prevention should be implemented, reducing abdominal obesity and dyslipidemia. Healthy dietary habits and regular exercise should be emphasized as a part of such a strategy. PMID:26417407
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gupta, Shlok; Kong, Weidong; Booth, Christopher M.
2014-01-01
Purpose: Clinical trials have shown that the addition of chemotherapy to radiation therapy (RT) improves survival in advanced head-and-neck cancer. The objective of this study was to describe the effectiveness of concomitant chemoradiation therapy (C-CRT) in routine practice. Methods and Materials: This was a population-based cohort study. Electronic records of treatment from all provincial cancer centers were linked to a population--based cancer registry to describe the adoption of C-CRT for head-and-neck cancer patients in Ontario, Canada. The study population was then divided into pre- and postadoption cohorts, and their outcomes were compared. Results: Between 1992 and 2008, 18,867 patients hadmore » diagnoses of head-and-neck cancer in Ontario, of whom 7866 (41.7%) were treated with primary RT. The proportion of primary RT cases that received C-CRT increased from 2.2% in the preadoption cohort (1992-1998) to 39.3% in the postadoption cohort (2003-2008). Five-year survival among all primary RT cases increased from 43.6% in the preadoption cohort to 51.8% in the postadoption cohort (P<.001). Over the same period, treatment-related hospital admissions increased significantly, but there was no significant increase in treatment-related deaths. Conclusions: C-CRT was widely adopted in Ontario after 2003, and its adoption was temporally associated with an improvement in survival.« less
Ribeiro, Armindo Sousa; Seixas, Rui; Gálvez, Juan Manuel; Climent, Vicente
2018-05-16
The primary objective of our study is to determine the prevalence of the metabolic syndrome in the population. The secondary objective is to determine the prevalence of cardiovascular risk factors, anthropometric alterations and the prevalence of target organ damage and their relationship with aging. The sample for the study was obtained by means of a consecutive population-based demonstration in 803 adults over 18 years of age belonging to the labor force of the company Grupo Delta SA. The study was carried out according to the guidelines of the Declaration of Helsinki. The individuals included in the study voluntarily participated, once informed of the purpose of the study, giving their prior verbal consent, to the company's human resources department, in the case of Delta Group workers. 23.8% of the population has metabolic syndrome more prevalent in males, no smoking, no significant alcohol consumption, sedentary, with a high Body mass index (BMI). Its prevalence increases with age. We found that the prevalence of metabolic syndrome increases with age and is present in people of working age, increasing the risk of cardiovascular diseases, work-related absences, and socio-economic costs. Copyright © 2018 Diabetes India. Published by Elsevier Ltd. All rights reserved.
Yilmaz, Sevgi; Toy, Süleyman; Demircioglu Yildiz, Nalan; Yilmaz, Hasan
2009-01-01
In the study, main purpose was to determine the effect of population growth along with the increase in urbanisation, motor vehicle use and green area amount on the temperature values using a 55-year data set in Erzurum, which is hardly industrialised, and one of the coldest cities with highest elevation in Turkey. Although the semi-decadal increases, means of which are 0.1 degrees C for mean, minimum and maximum temperatures, are not clear enough to make a strong comment even in the lights of figures or tables, it was found as the result of the statistical analysis that population growth and increases in the number of vehicles, the number of buildings and the green area amount in the city have no significant effect on mean temperatures. However, the relationships between population growth and maximum temperature; and the number of vehicles and minimum temperature were found to be statistically significant.
Yracheta, Joseph M; Alfonso, Javier; Lanaspa, Miguel A; Roncal-Jimenez, Carlos; Johnson, Sarah B; Sánchez-Lozada, Laura G; Johnson, Richard J
2015-06-01
The Hispanic American, the largest minority population in the United States, is at increased risk for obesity, diabetes and end-stage renal disease. Here we review genetic and environmental factors that might account for their increased risk for these conditions. Whereas many environmental and genetic factors have important roles in driving the increased risk for obesity and kidney disease in this population, a case is made that excessive intake of sugary beverages is a contributory cause. Studies focusing on decreasing intake of sugary beverages among the Hispanic American could potentially reduce renal and cardiovascular complications in this population.
López-Uribe, Margarita M; Morreale, Stephen J; Santiago, Christine K; Danforth, Bryan N
2015-01-01
Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei's GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators.
López-Uribe, Margarita M.; Morreale, Stephen J.; Santiago, Christine K.; Danforth, Bryan N.
2015-01-01
Bees are the primary pollinators of flowering plants in almost all ecosystems. Worldwide declines in bee populations have raised awareness about the importance of their ecological role in maintaining ecosystem functioning. The naturally strong philopatric behavior that some bee species show can be detrimental to population viability through increased probability of inbreeding. Furthermore, bee populations found in human-altered landscapes, such as urban areas, can experience lower levels of gene flow and effective population sizes, increasing potential for inbreeding depression in wild bee populations. In this study, we investigated the fine-scale population structure of the solitary bee Colletes inaequalis in an urbanized landscape. First, we developed a predictive spatial model to detect suitable nesting habitat for this ground nesting bee and to inform our field search for nests. We genotyped 18 microsatellites in 548 female individuals collected from nest aggregations throughout the study area. Genetic relatedness estimates revealed that genetic similarity among individuals was slightly greater within nest aggregations than among randomly chosen individuals. However, genetic structure among nest aggregations was low (Nei’s GST = 0.011). Reconstruction of parental genotypes revealed greater genetic relatedness among females than among males within nest aggregations, suggesting male-mediated dispersal as a potentially important mechanism of population connectivity and inbreeding avoidance. Size of nesting patch was positively correlated with effective population size, but not with other estimators of genetic diversity. We detected a positive trend between geographic distance and genetic differentiation between nest aggregations. Our landscape genetic models suggest that increased urbanization is likely associated with higher levels of inbreeding. Overall, these findings emphasize the importance of density and distribution of suitable nesting patches for enhancing bee population abundance and connectivity in human dominated habitats and highlights the critical contribution of landscape genetic studies for enhanced conservation and management of native pollinators. PMID:25950429
Piziak, Veronica
2012-01-01
The prevalence of early childhood obesity has increased dramatically particularly among the Mexican American population. Obesity leads to earlier onset of related diseases such as type 2 diabetes. The Head Start population of Texas is largely Mexican American. Dietary intake in this population demonstrated a diet very low in fiber, high in salt, and containing excessive calories with a low intake of fruit and vegetables. This study was performed in a Texas Head Start population to evaluate a bilingual pictorial nutrition education game. Acceptance of the bilingual concept and the game had been previously studied in a Head Start population in five Texas counties. The effectiveness in producing a change in eating habits was studied as a pilot project 413 children and their parents at the Bastrop County Head Start. Parents were asked to supply data about at home food frequency at the beginning and the end of the school year and the results compared. The parents were given a demonstration of the educational objectives and the students played the game throughout the year. By the end of the school year there was a statistically significant increase in the vegetables offered to this population both during the week at home (p = 0.009) and on the weekends (p = 0.02). PMID:22690195
Piziak, Veronica
2012-04-01
The prevalence of early childhood obesity has increased dramatically particularly among the Mexican American population. Obesity leads to earlier onset of related diseases such as type 2 diabetes. The Head Start population of Texas is largely Mexican American. Dietary intake in this population demonstrated a diet very low in fiber, high in salt, and containing excessive calories with a low intake of fruit and vegetables. This study was performed in a Texas Head Start population to evaluate a bilingual pictorial nutrition education game. Acceptance of the bilingual concept and the game had been previously studied in a Head Start population in five Texas counties. The effectiveness in producing a change in eating habits was studied as a pilot project 413 children and their parents at the Bastrop County Head Start. Parents were asked to supply data about at home food frequency at the beginning and the end of the school year and the results compared. The parents were given a demonstration of the educational objectives and the students played the game throughout the year. By the end of the school year there was a statistically significant increase in the vegetables offered to this population both during the week at home (p = 0.009) and on the weekends (p = 0.02).
Incorporating Case Studies into a World Food and Population Course
ERIC Educational Resources Information Center
Econopouly, Bethany F.; Byrne, Patrick F.; Johnson, Marc A.
2010-01-01
The use of case studies in college courses can increase student engagement with the subject matter and improve analytical, problem-solving, and communication skills. Case studies were introduced in a relatively large (54 students) undergraduate world food and population course at Colorado State University in the spring semester of 2008 and…
Gross, C. L.; Mackay, D.
2014-01-01
Background and Aims Olearia flocktoniae is an endangered shrub that was passively translocated from its natural ecosystem, where it has since gone extinct. This study aimed to determine sensitivities vital to populations persisting in human-created areas. Methods Population colonization, longevity and extinction were investigated over 20 years using 133 populations. Seed-bank longevity was determined from germination trials of seeds exhumed from extinct and extant sites via a 10-year glasshouse trial and by in situ sowing experiments. 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) with different disturbance histories were used to evaluate sensitivities in vital rates. Key Results Most populations had few individuals (∼30) and were transient (<5 years above ground). The intrinsic population growth rate was rarely >1 and all but two populations were extinct at year 20. Seeds were short-lived in situ. Although >1000 seeds per plant were produced annually in most populations, sensitivity analysis showed that the transition to the seed bank and the transition from the seed bank to seedlings are key vulnerabilities in the life-cycle. Conclusions Seedling establishment is promoted by recent disturbance. Increasing the number of disturbance events in populations, even severe disturbances that almost extirpate populations, significantly increases longer-term population persistence. Only populations that were disturbed annually survived the full 20 years of the study. The results show that translocated populations of O. flocktoniae will fail to persist without active management. PMID:24844983
Cartee, Amanda K.; Owens, Lisa A.; Lahr, Brian D.; Yawn, Barbara P.; Murray, Joseph A.; Kudva, Yogish C.
2016-01-01
Context Worldwide studies show that the type 1 diabetes (T1D) incidence is increasing by 3% annually. Objectives We investigated the recent incidence of T1D in a US Midwestern county to determine whether this increase has been sustained and compare to celiac disease (CD) incidence. The prevalence of (CD), an associated autoimmune disease, within the cohort was also investigated. Design A broad search strategy was used to identify all cases of T1D in Olmsted County, Minnesota, between January 1,1994 and December 31, 2010 using the Rochester Epidemiology Project. Diagnosis and residency status were confirmed through the medical record. Incidence rates were directly standardized to the 2010 United States population. Poisson regression was used to test for a change in incidence rate. Clinical charts were reviewed to confirm case status. Setting Population-based study in Olmsted County, Minnesota. Main Outcome Measure The trend in T1D incidence in a population-based study in a Midwestern US county. Results There were 233 incident cases of T1D. Directly adjusting for age and sex with respect to the 2010 US white population, the overall annual incidence of T1D was 9.2 (95% CI, 8.0-10.4) per 100,000 people per year among all ages and 19.9 (95% CI, 16.6-23.2) per 100,000 per people per year for those younger than 20 years. There was no significant increase in the incidence of T1D over time (P=.45). Despite the overall stability in annual incidence, there was an initial increasing trend followed by a plateau. Of the 109 T1D patients (46%) tested for CD, 12% had biopsy-proven CD. Conclusions The incidence of T1D has stopped increasing in Olmsted County, Minnesota, in the most recent decade. Further studies are needed to confirm this finding and explore reasons for this plateau. PMID:27492913
Interventions to promote cycling: systematic review
Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J
2010-01-01
Objectives To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Design Systematic review. Data sources Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled “before and after” experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Results Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of “environmentally friendly” modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Conclusions Community-wide promotional activities and improving infrastructure for cycling have the potential to increase cycling by modest amounts, but further controlled evaluative studies incorporating more precise measures are required, particularly in areas without an established cycling culture. Studies of individualised marketing report consistent positive effects of interventions on cycling behaviour, but these findings should be confirmed using more robust study designs. Future research should also examine how best to promote cycling in children and adolescents and through workplaces. Whether interventions to promote cycling result in an increase in overall physical activity or changes in anthropometric measures is unclear. PMID:20959282
Interventions to promote cycling: systematic review.
Yang, Lin; Sahlqvist, Shannon; McMinn, Alison; Griffin, Simon J; Ogilvie, David
2010-10-18
To determine what interventions are effective in promoting cycling, the size of the effects of interventions, and evidence of any associated benefits on overall physical activity or anthropometric measures. Systematic review. Published and unpublished reports in any language identified by searching 13 electronic databases, websites, reference lists, and existing systematic reviews, and papers identified by experts in the field. Review methods Controlled "before and after" experimental or observational studies of the effect of any type of intervention on cycling behaviour measured at either individual or population level. Twenty five studies (of which two were randomised controlled trials) from seven countries were included. Six studies examined interventions aimed specifically at promoting cycling, of which four (an intensive individual intervention in obese women, high quality improvements to a cycle route network, and two multifaceted cycle promotion initiatives at town or city level) were found to be associated with increases in cycling. Those studies that evaluated interventions at population level reported net increases of up to 3.4 percentage points in the population prevalence of cycling or the proportion of trips made by bicycle. Sixteen studies assessing individualised marketing of "environmentally friendly" modes of transport to interested households reported modest but consistent net effects equating to an average of eight additional cycling trips per person per year in the local population. Other interventions that targeted travel behaviour in general were not associated with a clear increase in cycling. Only two studies assessed effects of interventions on physical activity; one reported a positive shift in the population distribution of overall physical activity during the intervention. Community-wide promotional activities and improving infrastructure for cycling have the potential to increase cycling by modest amounts, but further controlled evaluative studies incorporating more precise measures are required, particularly in areas without an established cycling culture. Studies of individualised marketing report consistent positive effects of interventions on cycling behaviour, but these findings should be confirmed using more robust study designs. Future research should also examine how best to promote cycling in children and adolescents and through workplaces. Whether interventions to promote cycling result in an increase in overall physical activity or changes in anthropometric measures is unclear.
Papasozomenou, Panayiota; Athanasiadis, Apostolos P; Zafrakas, Menelaos; Panteris, Eleftherios; Loufopoulos, Aristoteles; Assimakopoulos, Efstratios; Tarlatzis, Basil C
2016-03-01
To compare normal ranges of ultrasonographically measured fetal nasal bone length in the second trimester between different ethnic groups. A prospective, non-interventional study in order to establish normal ranges of fetal nasal bone length in the second trimester in a Greek population was conducted in 1220 singleton fetuses between 18 completed weeks and 23 weeks and 6 days of gestation. A literature search followed in order to identify similar studies in different population groups. Fetal nasal bone length mean values and percentiles from different population groups were compared. Analysis of measurements in the Greek population showed a linear association, i.e., increasing nasal bone length with increasing gestational age from 5.73 mm at 18 weeks to 7.63 mm at 23 weeks. Eleven studies establishing normal ranges of fetal nasal bone length in the second trimester were identified. Comparison of fetal nasal bone length mean values between the 12 population groups showed statistically significant differences (P<0.0001). Normal ranges of fetal nasal bone length in the second trimester vary significantly between different ethnic groups. Hence, distinct ethnic nomograms of fetal nasal bone length in the second trimester should be used in a given population rather than an international model.
Brennan, Adrian C; Harris, Stephen A; Hiscock, Simon J
2003-06-29
Senecio squalidus L. (Asteraceae) has been the subject of several ecological and population genetic studies due to its well-documented history of introduction, establishment and spread throughout Britain in the past 300 years. Our recent studies have focused on identifying and quantifying factors associated with the sporophytic self-incompatibility (SSI) system of S. squalidus that may have contributed to its success as a colonist. These findings are of general biological interest because they provide important insights into the short-term evolutionary dynamics of a plant mating system. The number of S-alleles in populations and their dominance interactions were investigated in eight wild British populations using cross-diallel studies. The numbers of S-alleles in British S. squalidus populations are typically low (average of 5.3 S-alleles) and the entire British population is estimated to possess no more than 7-11 S-alleles. Such low numbers of S-alleles are most probably a consequence of population bottlenecks associated with introduction and colonization. Potential evolutionary impacts on SSI caused by a paucity of S-alleles, such as restricted mate availability, are discussed, and we suggest that increased dominance interactions between S-alleles may be an important short-term means of increasing mate availability when S-allele numbers are low.
Urbanization and physician maldistribution: a longitudinal study in Japan
2011-01-01
Background The relative shortage of physicians in Japan's rural areas is an important issue in health policy. In the 1970s, the Japanese government began a policy to increase the number of medical students and to achieve a better distribution of physicians. Beginning in 1985, however, admissions to medical school were reduced to prevent a future oversupply of physicians. In 2007, medical school entrants equaled just 92% of their 1982 peers. The urban annual population growth rate is positive and the rural is negative, a trend that may affect denominator populations and physician distribution. Methods Our data cover six time points and span a decade: 1998, 2000, 2002, 2004, 2006, and 2008. The spatial units for analysis are the secondary tier of medical care (STM) as defined by the Medical Service Law and related legislation. We examined trends in the geographic disparities in population and physician distribution among 348 STMs in Japan. We compared populations and the number of physicians per 100,000 populations in each STM. To measure maldistribution quantitatively, we calculated Gini coefficients for physician distribution. Results Between 1998 and 2008, the total population and the number of practicing physicians for every 100,000 people increased by 0.95% and 13.6%, respectively. However, the inequality of physician distribution remained constant, although small and mostly rural areas experienced an increase in physician to population ratios. In contrast, as the maldistribution of population escalated during the same period, the Gini coefficient of population rose. Although the absolute number of practicing physicians in small STMs decreased, the fall in the denominator population of the STMs resulted in an increase in the number of practicing physicians per population in those located in rural areas. Conclusions A policy that increased the number of physicians and the physician to population ratios between 1998 and 2008 in all geographic areas of Japan, irrespective of size, did not lead to a more equal geographical distribution of physicians. The ratios of physicians to population in small rural STMs increased because of concurrent trends in urbanization and not because of a rise in the number of practicing physicians. PMID:21982582
Cheung, Chui Ming Gemmy; Ong, Peng Guan; Neelam, Kumari; Tan, Pok Chien; Shi, Yuan; Mitchell, Paul; Wang, Jie Jin; Sabanayagam, Charumathi; Cheng, Ching-Yu; Wong, Tien Yin
2017-09-01
To determine the 6-year incidence of early and late age-related macular degeneration (AMD) in a Singaporean Malay population and to validate the Age-Related Eye Disease Study (AREDS) simplified severity scale in Asians. Prospective, population cohort study. The Singapore Malay Eye Study baseline participants (age, ≥40 years; 2006-2008) were followed up in 2011 through 2013, and 1901 of 3280 of eligible participants (72.1%) took part. Fundus photographs were graded using the Wisconsin AMD grading system. Incidence of early and late AMD. Gradable fundus photographs were available for 1809 participants who attended both baseline and 6-year follow-up examinations. The age-standardized incidences of early and late AMD were 5.89% (95% confidence interval [CI], 4.81-7.16) and 0.76% (95% CI, 0.42-1.29), respectively. The 5-year age-standardized incidence of early AMD (calculated based on the 6-year incidence) was lower in our population (5.58%; 95% CI, 4.43-7.01) compared with the Beaver Dam Eye Study population (8.19%). The incidence of late AMD in our population was similar to that of the Beaver Dam Eye Study population (0.98% [95% CI, 0.49-1.86] vs. 0.91%), the Blue Mountains Eye Study population (1.10% [95% CI, 0.52-9.56] vs. 1.10%), and the Hisayama Study population (1.09% [95% CI, 0.54-4.25] vs. 0.84%). The incidence of late AMD increased markedly with increasing baseline AREDS score (step 0, 0.23%; step 4, 9.09%). This study documented the incidence of early and late AMD in a Malay population. The AREDS simplified severity scale is useful in predicting the risk of late AMD development in Asians. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.
High population variability and source-sink dynamics in a solitary bee species.
Franzén, Markus; Nilsson, Sven G
2013-06-01
Although solitary bees are considered to play key roles in ecosystem functions, surprisingly few studies have explored their population dynamics. We investigated the population dynamics of a rare, declining, solitary bee (Andrena humilis) in a landscape of 80 km2 in southern Sweden from 2003 to 2011. Only one population was persistent throughout all years studied; most likely this population supplied the surrounding landscape with 11 smaller, temporary local populations. Despite stable pollen availability, the size of the persistent population fluctuated dramatically in a two-year cycle over the nine years, with 490-1230 nests in odd-numbered years and 21-48 nests in even-numbered years. These fluctuations were not significantly related to climatic variables or pollen availability. Nineteen colonization and 14 extinction events were recorded. Occupancy decreased with distance from the persistent population and increased with increasing resource (pollen) availability. There were significant positive correlations between the size of the persistent population and patch occupancy and colonization. Colonizations were generally more common in patches closer to the persistent population, whereas extinctions were independent of distance from the persistent population. Our results highlight the complex population dynamics that exist for this solitary bee species, which could be due to source-sink dynamics, a prolonged diapause, or can represent a bet-hedging strategy to avoid natural enemies and survive in small habitat patches. If large fluctuations in solitary bee populations prove to be widespread, it will have important implications for interpreting ecological relationships, bee conservation, and pollination.
Incidence of Venous Thromboembolism in Asian Populations: A Systematic Review.
Lee, Lai Heng; Gallus, Alexander; Jindal, Ravul; Wang, Chen; Wu, Chau-Chung
2017-12-01
Introduction Despite a marked recent increase in the number of publications describing the incidence of venous thromboembolism (VTE) in Asia, and especially in mainland China, Hong Kong, Taiwan, Korea, Japan and Singapore, there remains a lack of consensus on the true risks, and trends over time, to inform appropriate clinical practice. The purpose of this systematic review was therefore to examine evidence about the incidence of symptomatic VTE in Asia. Methods Databases were searched for studies from Asia, published between January 1995 and February 2016, on the incidence of symptomatic VTE, deep vein thrombosis (DVT) or pulmonary embolism. Review of eligible studies was conducted independently by two reviewers. Data were extracted on incidence, predispositions and recurrence of VTE. Results One thousand nighty-five studies were identified, of which 73 were eligible for full text review and data extraction. Three population-wide estimates of VTE rates identified from Korea, Taiwan and Hong Kong reported annual incidences of 13.8, 15.9 and 19.9 per 100,000, respectively. Nine studies of Asian hospital registries or databases reported VTE rates ranging from 11 to 88 cases per 10,000 admissions. Population-based estimates of post-surgical DVT rates ranged from 0.15 to 1.35%. Age was a significant risk factor for VTE in all population groups. Conclusion Population-wide incidence estimates in Asia were approximately 15 to 20% of the levels recorded in western countries but have increased over time. It is anticipated this synthesis of evidence on the incidence of VTE and its predisposing factors will increase awareness about VTE in Asian populations.
Paradoxical effects of density on measurement of copper tolerance in Silene paradoxa L.
Capuana, Maurizio; Colzi, Ilaria; Buccianti, Antonella; Coppi, Andrea; Palm, Emily; Del Bubba, Massimo; Gonnelli, Cristina
2018-01-01
This work investigated if the assessment of tolerance to trace metals can depend on plant density in the experimental design. A non-metallicolous and a metallicolous populations of Silene paradoxa were hydroponically cultivated at increasing density and in both the absence (-Cu conditions) and excess of copper (+Cu conditions). In -Cu conditions, the metallicolous population showed a lower susceptibility to plant density in comparison to the non-metallicolous one, explained by a higher capacity of the metallicolous population to exploit resources. In +Cu conditions, an alleviating effect of increasing density was found in roots. Such effect was present to a greater extent in the non-metallicolous population, thus making the populations equally copper-tolerant at the highest density used. In shoots, an additive effect of increasing plant density to copper toxicity was reported. Its higher intensity in the metallicolous population reverted the copper tolerance relationship at the highest plant densities used. In both populations, a density-induced decrease in root copper accumulation was observed, thus concurring to the reported mitigation in +Cu conditions. Our work revealed the importance of density studies on the optimization of eco-toxicological bioassays and of metal tolerance assessment and it can be considered the first example of an alleviating effect of increasing plant number on copper stress in a metallophyte.
Dahl, Christopher R.; Bickham, John W.; Wickliffe, Jeffery K.; Custer, Thomas W.
2001-01-01
DNA sequence analysis of a 215 base-pair region of the mitochondrial cytochrome b gene was used to examine genetic variation and search for evidence of an increased mutation rate in black-crowned night-herons. We examined five populations exposed to environmental contamination (primarily PAHs and PCBs) and one reference population from the eastern U.S. There was no evidence of a high mutation rate even within populations previously shown to exhibit increased variation in DNA content among somatic cells as a result of petroleum exposure. Three haplotypes were observed among 99 individuals. The low level of variability could be evidence for a genetic bottleneck, or that cytochrome b is too conservative for use in population genetic studies of this species. With the exception of one population from Louisiana, pair-wise Phist estimates were very low, indicative of little population structure and potentially high rates of effective migration among populations.
Feldman, Adina L; Long, Gráinne H; Johansson, Ingegerd; Weinehall, Lars; Fhärm, Eva; Wennberg, Patrik; Norberg, Margareta; Griffin, Simon J; Rolandsson, Olov
2017-03-29
Promoting positive changes in lifestyle behavior in the whole population may be a feasible and effective approach to reducing type 2 diabetes burden, but the impact of population shifts of modifiable risk factors remains unclear. Currently most of the evidence on modifiable lifestyle behavior and type 2 diabetes risk on a population level comes from studies of between-individual differences. The objective of the study was to investigate the association and potential impact on disease burden for within-individual change in lifestyle behavior and diabetes risk. Population-based prospective cohort study of 35,680 participants aged 30-50 at baseline in 1990-2003 in Västerbotten County, Sweden (follow-up until 2013). Five self-reported modifiable lifestyle behaviors (tobacco use, physical activity, alcohol intake, dietary fiber intake and dietary fat intake) were measured at baseline and 10 year follow-up. Lifestyle behaviors were studied separately, and combined in a score. Incident diabetes was detected by oral glucose tolerance tests. Multivariate logistic regression models and population attributable fractions (PAF) were used to analyze the association between change in lifestyle behavior between baseline and 10 year follow-up, and risk of incident diabetes. Incident diabetes was detected in 1,184 (3.3%) participants at 10 year follow-up. There was a reduced diabetes risk associated with increase in dietary fiber intake, odds ratio (OR) 0.79 (95% confidence interval (CI) 0.66, 0.96) for increase of at least one unit standard deviation (3.0 g/1,000 kcal) of the baseline distribution, PAF 16.0% (95% CI 4.2, 26.4%). Increase in the lifestyle behavior score was associated with reduced diabetes risk, OR 0.92 (95% CI 0.85, 0.99) per unit increase of the score. These results support a causal link between lifestyle behavior and type 2 diabetes incidence. A small shift in lifestyle behaviors, in particular intake of dietary fiber, has the potential to reduce diabetes burden in the population and might be a suitable target for public health intervention.
White, Richard S A; McHugh, Peter A; McIntosh, Angus R
2016-10-01
Because smaller habitats dry more frequently and severely during droughts, habitat size is likely a key driver of survival in populations during climate change and associated increased extreme drought frequency. Here, we show that survival in populations during droughts is a threshold function of habitat size driven by an interaction with population density in metapopulations of the forest pool dwelling fish, Neochanna apoda. A mark-recapture study involving 830 N. apoda individuals during a one-in-seventy-year extreme drought revealed that survival during droughts was high for populations occupying pools deeper than 139 mm, but declined steeply in shallower pools. This threshold was caused by an interaction between increasing population density and drought magnitude associated with decreasing habitat size, which acted synergistically to increase physiological stress and mortality. This confirmed two long-held hypotheses, firstly concerning the interactive role of population density and physiological stress, herein driven by habitat size, and secondly, the occurrence of drought survival thresholds. Our results demonstrate how survival in populations during droughts will depend strongly on habitat size and highlight that minimum habitat size thresholds will likely be required to maximize survival as the frequency and intensity of droughts are projected to increase as a result of global climate change. © 2016 John Wiley & Sons Ltd.
Implementation of a national near-road NO2 monitoring network--conference
In recent years, a large number of health studies have identified increased risks of adverse health effects for populations spending significant time near major roads. These studies indicate that populations living, working or going to school near major roads may be subjected to ...
Chiu, C-C; Wang, J-J; Chen, Y-S; Chen, J-J; Tsai, T-C; Lai, C-C; Sun, D-P; Shi, H-Y
2015-09-01
Despite the huge and growing global burden of hepatocellular carcinoma (HCC), high-quality population-based studies of HCC prevalence and outcomes are scarce. To analyze trends and predictors of hospital resource utilization and mortality rates in a population of patients who had received HCC surgery. This population-based patient cohort study retrospectively analyzed 23,107 patients who had received surgical treatment for HCC from 1998 to 2009. The prevalence rate of surgical treatment in HCC patients significantly increased by 167.4% from 4.857 per 100,000 persons in 1998 to 12.989 per 100,000 persons in 2009 (P < 0.001). Age, gender, Deyo-Charlson co-morbidity index score, hospital volume, surgeon volume, digestive system disease, hepatitis type and liver cirrhosis were significantly associated with HCC surgical outcomes (P < 0.05). Over the 12-year period analyzed, the estimated mean hospital treatment cost increased 9.4% whereas mean length of stay (LOS) decreased 25.3%. The estimated mean overall survival time after HCC surgery was 40.9 months (SD 1.2 months), and the overall in-hospital 1-, 3-, and 5-year survival rates were 97.2%, 79.9%, 61.1%, and 54.6%, respectively. These population-based data reveal that the prevalence of HCC has increased, especially in older patients. Additionally, hospital treatment costs for HCC have increased despite decreases in LOS. These analytical results should be applicable to most countries with relatively small populations. Additionally, healthcare providers and patients should recognize that attributes of both the patient and the hospital may affect outcomes. Copyright © 2015 Elsevier Ltd. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com; Mahasakpan, Pranee; Limpatanachote, Pisit
Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4{+-}2.3 {mu}g/g creatinine) was significantly greater than that for men (2.0{+-}2.2 {mu}g/g creatinine). Hypertension was presentedmore » in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.« less
Population dynamics of Microtus pennsylvanicus in corridor-linked patches
Coffman, C.J.; Nichols, J.D.; Pollock, K.H.
2001-01-01
Corridors have become a key issue in the discussion of conservation planning: however, few empirical data exist on the use of corridors and their effects on population dynamics. The objective of this replicated, population level, capture-re-capture experiment on meadow voles was to estimate and compare population characteristics of voles between (1) corridor-linked fragments, (2) isolated or non-linked fragments, and (3) unfragmented areas. We conducted two field experiments involving 22600 captures of 5700 individuals. In the first, the maintained corridor study, corridors were maintained at the time of fragmentation, and in the second, the constructed corridor study, we constructed corridors between patches that had been fragmented for some period of time. We applied multistate capture-recapture models with the robust design to estimate adult movement and survival rates, population size, temporal variation in population size, recruitment, and juvenile survival rates. Movement rates increased to a greater extent on constructed corridor-linked grids than on the unfragmented or non-linked fragmented grids between the pre- and post-treatment periods. We found significant differences in local survival on the treated (corridor-linked) grids compared to survival on the fragmented and unfragmented grids between the pre- and post-treatment periods. We found no clear pattern of treatment effects on population size or recruitment in either study. However, in both studies, we found that unfragmented grids were more stable than the fragmented grids based on lower temporal variability in population size. To our knowledge, this is the first experimental study demonstrating that corridors constructed between existing fragmented populations can indeed cause increases in movement and associated changes in demography, supporting the use of constructed corridors for this purpose in conservation biology.
Frohnauer, N.K.; Pierce, C.L.; Kallemeyn, L.W.
2007-01-01
The genetically unique population of muskellunge Esox masquinongy inhabiting Shoepack Lake in Voyageurs National Park, Minnesota, is potentially at risk for loss of genetic variability and long-term viability. Shoepack Lake has been subject to dramatic surface area changes from the construction of an outlet dam by beavers Castor canadensis and its subsequent failure. We simulated the long-term dynamics of this population in response to recruitment variation, increased exploitation, and reduced habitat area. We then estimated the effective population size of the simulated population and evaluated potential threats to long-term viability, based on which we recommend management actions to help preserve the long-term viability of the population. Simulations based on the population size and habitat area at the beginning of a companion study resulted in an effective population size that was generally above the threshold level for risk of loss of genetic variability, except when fishing mortality was increased. Simulations based on the reduced habitat area after the beaver dam failure and our assumption of a proportional reduction in population size resulted in an effective population size that was generally below the threshold level for risk of loss of genetic variability. Our results identified two potential threats to the long-term viability of the Shoepack Lake muskellunge population, reduction in habitat area and exploitation. Increased exploitation can be prevented through traditional fishery management approaches such as the adoption of no-kill, barbless hook, and limited entry regulations. Maintenance of the greatest possible habitat area and prevention of future habitat area reductions will require maintenance of the outlet dam built by beavers. Our study should enhance the long-term viability of the Shoepack Lake muskellunge population and illustrates a useful approach for other unique populations. ?? Copyright by the American Fisheries Society 2007.
Rahman, M M; Baker, G; Powis, K J; Roush, R T; Schmidt, O
2010-08-01
Field surveys of pest insect pest populations in agroecosystems reveal low but significant levels of tolerance to synthetic and biological pesticides but fail to uncover resistance alleles in test crosses. To study the potential of inducible mechanisms to generate tolerance to synthetic pesticides, we performed baseline susceptibility studies in field and laboratory populations of diamondback moth, Plutella xylostella (L.), to commercial formulations of emamectin benzoate. Pesticide exposure in the field caused elevated levels of tolerance, which decreased in field-collected populations after maintaining insects with pesticide-free diet in the laboratory. Because no significant resistance alleles were identified in back-crossed individuals, the observed increase in tolerance was probably not based on preexisting recessive resistance mechanisms in the population. Instead, the genetic analysis after five and 12 generations is compatible with a transient up-regulation of an immune and metabolic status in tolerant insects that can be transmitted to offspring by a maternal effect. Although the epigenetic effects contributed to incremental increases in tolerance in the first five generations, other resistance mechanisms that are transmitted genetically predominate after 12 generations of increased exposure to the pesticide.
Vulnerability Risk Index Profile for Elder Abuse in Community-Dwelling Population
Dong, XinQi; Simon, Melissa A.
2013-01-01
Objectives Elder abuse is associated with increased morbidity and mortality. This study aims to develop a vulnerability index for elder abuse in a community-dwelling population. Design Population-based study Setting Geographically defined community in Chicago. Participants A population-based study was conducted in Chicago of community-dwelling older adults who participated in the Chicago Health and Aging Project (CHAP). Of the 8,157 participants in the CHAP study, 213 participants were reported to social services agency for suspected elder abuse. Measurements A vulnerability index for elder abuse was constructed from sociodemographic, health-related, and psychosocial factors. The outcomes of interest were reported and confirmed elder abuse. Logistic regression models were used to determine the accuracy of the index with respect to elder abuse outcomes. Results Out of the selected risk index for elder abuse, every one point increase in the 9 item vulnerability index items, there was a two fold increase in the risk for reported elder abuse (OR, 2.19 (2.00–2.40) and confirmed elder abuse (OR, 2.19 (1.94–2.47). Compared to the reference group, older adults with 3–4 vulnerability index items had increased risk for reported elder abuse (OR, 2.98 (1.98–4.49) and confirmed elder abuse (OR, 3.90, (2.07–7.36); and older adults with 5 or more risk index items, there was an 18 fold increase in risk for reported elder abuse (OR, 18.46 (12.15–28.04) and confirmed elder abuse (OR, 26.79 (14.18–50.61). Receiver Operating Characteristic (ROC) statistically derived curves for identifying reported elder abuse ranged between 0.77–0.84 and for predicting confirmed elder abuse ranged between 0.79–0.86. Conclusion The vulnerability risk index demonstrates value for identifying individuals at risk for elder abuse. Additional studies are needed to validate this index in other community dwelling populations. PMID:25180376
Population Dynamics of Belonolaimus longicaudatusin a Cotton Production System
Crow, W. T.; Weingartner, D. P.; McSorley, R.; Dickson, D. W.
2000-01-01
Belonolaimus longicaudatus is a recognized pathogen of cotton (Gossypium hirsutum), but insufficient information is available on the population dynamics and economic thresholds of B. longicaudatus in cotton production. In this study, data collected from a field in Florida were used to develop models predicting population increases of B. longicaudatus on cotton and population declines under clean fallow. Population densities of B. longicaudatus increased on cotton, reaching a carrying capacity of 139 nematodes/130 cm³ of soil, but decreased exponentially during periods of bare fallow. The model indicated that population densities should decrease each year of monocropped cotton, if an alternate host is not present between sequential cotton crops. Economic thresholds derived from published damage functions and current prices for cotton and nematicides varied from 2 to 5 B. longicaudatus/130 cm³ of soil, depending on the nematicide used. PMID:19270968
Annequin, Margot; Lert, France; Spire, Bruno; Dray-Spira, Rosemary
2016-01-01
Despite improved health, unemployment has increased among people living with HIV (PlwHIV) over the last decade. However, since the economic recession of 2008, unemployment also increased in the French general population. This paper aimed to determine if the increase in the unemployment rate in the HIV population was higher than that in the French general population. We used data from the ANRS-Vespa study, a repeated cross-sectional survey among two national representative samples of PlwHIV followed at hospitals in France in 2003 and 2011. We compared employment and unemployment rates between HIV-infected people (overall and according to period of HIV diagnosis) and the French general population in 2003 and 2011, using multivariate Poisson regressions adjusted for individual sociodemographic characteristics. The employment rate among PlwHIV was consistently lower than that in the general population in 2003 and 2011. In contrast, there was a trend of an increasing unemployment rate difference between PlwHIV and the general population: PlwHIV's unemployment rate was 1.48 (95% confidence interval [CI]: 1.16-1.90) times higher than that of the general population in 2003, versus 1.62 (95% CI: 1.34-1.96) times higher in 2011. This unemployment rate difference was the highest for PlwHIV diagnosed in or after 2008 (adjusted prevalence rate ratio: 2.06; 95% CI: 1.59-2.67). These results suggest that in time of economic recession, an increasing proportion of PlwHIV may be excluded from the labor market although they are willing to re-enter it. This constitutes a major issue relative to social consequences of chronic disease.
Annequin, Margot; Lert, France; Spire, Bruno; Dray-Spira, Rosemary
2016-01-01
Background Despite improved health, unemployment has increased among people living with HIV (PlwHIV) over the last decade. However, since the economic recession of 2008, unemployment also increased in the French general population. This paper aimed to determine if the increase in the unemployment rate in the HIV population was higher than that in the French general population. Methods We used data from the ANRS-Vespa study, a repeated cross-sectional survey among two national representative samples of PlwHIV followed at hospitals in France in 2003 and 2011. We compared employment and unemployment rates between HIV-infected people (overall and according to period of HIV diagnosis) and the French general population in 2003 and 2011, using multivariate Poisson regressions adjusted for individual sociodemographic characteristics. Results The employment rate among PlwHIV was consistently lower than that in the general population in 2003 and 2011. In contrast, there was a trend of an increasing unemployment rate difference between PlwHIV and the general population: PlwHIV’s unemployment rate was 1.48 (95% confidence interval [CI]: 1.16–1.90) times higher than that of the general population in 2003, versus 1.62 (95% CI: 1.34–1.96) times higher in 2011. This unemployment rate difference was the highest for PlwHIV diagnosed in or after 2008 (adjusted prevalence rate ratio: 2.06; 95% CI: 1.59–2.67). Conclusions These results suggest that in time of economic recession, an increasing proportion of PlwHIV may be excluded from the labor market although they are willing to re-enter it. This constitutes a major issue relative to social consequences of chronic disease. PMID:27814374
Peprah, Emmanuel; Xu, Huichun; Tekola-Ayele, Fasil; Royal, Charmaine D.
2014-01-01
Genomic research is one of the tools for elucidating the pathogenesis of diseases of global health relevance, and paving the research dimension to clinical and public health translation. Recent advances in genomic research and technologies have increased our understanding of human diseases, genes associated with these disorders, and the relevant mechanisms. Genome-wide association studies (GWAS) have proliferated since the first studies were published several years ago, and have become an important tool in helping researchers comprehend human variation and the role genetic variants play in disease. However, the need to expand the diversity of populations in GWAS has become increasingly apparent as new knowledge is gained about genetic variation. Inclusion of diverse populations in genomic studies is critical to a more complete understanding of human variation and elucidation of the underpinnings of complex diseases. In this review, we summarize the available data on GWAS in recent-African ancestry populations within the western hemisphere (i.e. African Americans and peoples of the Caribbean) and continental African populations. Furthermore, we highlight ways in which genomic studies in populations of recent African ancestry have led to advances in the areas of malaria, HIV, prostate cancer, and other diseases. Finally, we discuss the advantages of conducting GWAS in recent African ancestry populations in the context of addressing existing and emerging global health conditions. PMID:25427668
ERIC Educational Resources Information Center
Pilat, Dirk
2016-01-01
Increasing workload due to reduced numbers of general practitioners, a population boom and an aging population has increased the need for accessible distance learning for the UK's primary care doctors. The Royal College of General Practitioners is now in its eighth year of delivering high quality e-learning to 72,000 registered users via its…
Juma, Dauglas Wafula; Wang, Hongtao; Li, Fengting
2014-04-01
Anthropogenic-induced water quality pollution is a major environmental problem in freshwater ecosystems today. As a result of this, eutrophication of lakes occurs. Population and economic development are key drivers of water resource pollution. To evaluate how growth in the riparian population and in the gross domestic product (GDP) with unplanned development affects the water quality of the lake, this paper evaluates Lake Victoria Kenyan waters basin. Waters quality data between 1990 and 2012 were analyzed along with reviews of published literature, papers, and reports. The nitrate-nitrogen (NO3-N), soluble phosphorus (PO4-P), chlorophyll a, and Secchi transparencies were evaluated as they are key water quality indicators. The NO3-N increased from 10 μg l(-1) in 1990 to 98 μg 1(-1) in 2008, while PO4-P increased from 4 μg l(-1) in 1990 to 57 μg l(-1) in 2008. The population and economic growth of Kenya are increasing with both having minimums in 1990 of 24.143 million people and 12.18 billion US dollars, to maximums in 2010 of 39.742 million people and 32.163 billion US dollars, respectively. A Secchi transparency is reducing with time, indicating an increasing pollution. This was confirmed by an increase in aquatic vegetation using an analysis of moderate resolution imaging spectroradiometer (MODIS) images of 2000 and 2012 of Kenyan waters. This study found that increasing population and GDP increases pollution discharge thus polluting lakes. One of major factors causing lake water pollution is the unplanned or poor waste management policy and service.
Hitiris, Nikolas; Mohanraj, Rajiv; Norrie, John; Brodie, Martin J
2007-05-01
All studies report an increased mortality risk for people with epilepsy compared with the general population. Population-based studies have demonstrated that the increased mortality is often related to the cause of the epilepsy. Common etiologies include neoplasia, cerebrovascular disease, and pneumonia. Deaths in selected cohorts, such as sudden unexpected death in epilepsy (SUDEP), status epilepticus (SE), suicides, and accidents are more frequently epilepsy-related. SUDEP is a particular cause for concern in younger people, and whether and when SUDEP should be discussed with patients with epilepsy remain problematic issues. Risk factors for SUDEP include generalized tonic-clonic seizures, increased seizure frequency, concomitant learning disability, and antiepileptic drug polypharmacy. The overall incidence of SE may be increasing, although case fatality rates remain constant. Mortality is frequently secondary to acute symptomatic disorders. Poor compliance with treatment in patients with epilepsy accounts for a small proportion of deaths from SE. The incidence of suicide is increased, particularly for individuals with epilepsy and comorbid psychiatric conditions. Late mortality figures in patients undergoing epilepsy surgery vary and are likely to reflect differences in case selection. Future studies of mortality should be prospective and follow agreed guidelines to better quantify risk and causation in individual populations.
Trend estimation in populations with imperfect detection
Kery, Marc; Dorazio, Robert M.; Soldaat, Leo; Van Strien, Arco; Zuiderwijk, Annie; Royle, J. Andrew
2009-01-01
1. Trends of animal populations are of great interest in ecology but cannot be directly observed owing to imperfect detection. Binomial mixture models use replicated counts to estimate abundance, corrected for detection, in demographically closed populations. Here, we extend these models to open populations and illustrate them using sand lizard Lacerta agilis counts from the national Dutch reptile monitoring scheme. 2. Our model requires replicated counts from multiple sites in each of several periods, within which population closure is assumed. Counts are described by a hierarchical generalized linear model, where the state model deals with spatio-temporal patterns in true abundance and the observation model with imperfect counts, given that true state. We used WinBUGS to fit the model to lizard counts from 208 transects with 1–10 (mean 3) replicate surveys during each spring 1994–2005. 3. Our state model for abundance contained two independent log-linear Poisson regressions on year for coastal and inland sites, and random site effects to account for unexplained heterogeneity. The observation model for detection of an individual lizard contained effects of region, survey date, temperature, observer experience and random survey effects. 4. Lizard populations increased in both regions but more steeply on the coast. Detectability increased over the first few years of the study, was greater on the coast and for the most experienced observers, and highest around 1 June. Interestingly, the population increase inland was not detectable when the observed counts were analysed without account of detectability. The proportional increase between 1994 and 2005 in total lizard abundance across all sites was estimated at 86% (95% CRI 35–151). 5. Synthesis and applications. Open-population binomial mixture models are attractive for studying true population dynamics while explicitly accounting for the observation process, i.e. imperfect detection. We emphasize the important conceptual benefit provided by temporal replicate observations in terms of the interpretability of animal counts.
Genetic structure of the Newfoundland and Labrador population: founder effects modulate variability.
Zhai, Guangju; Zhou, Jiayi; Woods, Michael O; Green, Jane S; Parfrey, Patrick; Rahman, Proton; Green, Roger C
2016-07-01
The population of the province of Newfoundland and Labrador (NL) has been a resource for genetic studies because of its historical isolation and increased prevalence of several monogenic disorders. Controversy remains regarding the genetic substructure and the extent of genetic homogeneity, which have implications for disease gene mapping. Population substructure has been reported from other isolated populations such as Iceland, Finland and Sardinia. We undertook this study to further our understanding of the genetic architecture of the NL population. We enrolled 494 individuals randomly selected from NL. Genome-wide SNP data were analyzed together with that from 14 other populations including HapMap3, Ireland, Britain and Native American samples from the Human Genome Diversity Project. Using multidimensional scaling and admixture analysis, we observed that the genetic structure of the NL population resembles that of the British population but can be divided into three clusters that correspond to religious/ethnic origins: Protestant English, Roman Catholic Irish and North American aboriginals. We observed reduced heterozygosity and an increased inbreeding coefficient (mean=0.005), which corresponds to that expected in the offspring of third-cousin marriages. We also found that the NL population has a significantly higher number of runs of homozygosity (ROH) and longer lengths of ROH segments. These results are consistent with our understanding of the population history and indicate that the NL population may be ideal for identifying recessive variants for complex diseases that affect populations of European origin.
NASA Astrophysics Data System (ADS)
Tay, T. T.; Low, Raymond; Loke, H. J.; Chua, Y. L.; Goh, Y. H.
2018-04-01
The proliferation of robotic technologies in recent years brings robots closer to humanities. There are many researches on going at various stages of development to bring robots into our homes, schools, nurseries, elderly care centres, offices, hospitals and factories. With recently developed robots having tendency to have appearance which increasingly displaying similarities to household animals and humans, there is a need to study the existence of uncanny valley phenomenon. Generally, the acceptance of people toward robots increases as the robots acquire increasing similarities to human features until a stage where people feel very uncomfortable, eerie, fear and disgust when the robot appearance become almost human like but not yet human. This phenomenon called uncanny valley was first reported by Masahiro Mori. There are numerous researches conducted to measure the existence of uncanny valley in Japan and European countries. However, there is limited research reported on uncanny valley phenomenon in Malaysia so far. In view of the different cultural background and exposure of Malaysian population to robotics technology compared to European or East Asian populations, it is worth to study this phenomenon in Malaysian context. The main aim of this work is to conduct a preliminary study to determine the existence of uncanny valley phenomenon in Malaysian urban and rural populations. It is interesting to find if there are any differences in the acceptance of the two set of populations despite of their differences. Among others the urban and rural populations differ in term of the rate of urbanization and exposure to latest technologies. A set of four interactive robotic faces and an ideal human model representing the fifth robot are used in this study. The robots have features resembling a cute animal, cartoon character, typical robot and human-like. Questionnaire surveys are conducted on respondents from urban and rural populations. Survey data collected are analysed to determine the preferred features in a humanoid robot, the acceptance of respondents toward the robotic faces and the existence of uncanny valley phenomenon. Based on the limited study, it is found that the uncanny valley phenomenon existed in both the Malaysian urban and rural population.
USDA-ARS?s Scientific Manuscript database
Small reference populations limit the accuracy of genomic prediction in numerically small breeds, such as the Danish Jersey. The objective of this study was to investigate two approaches to improve genomic prediction by increasing the size of the reference population for Danish Jerseys. The first ap...
Threatened and endangered species are increasingly impacted by agricultural pesticides. Interest in developing regulatory approaches that address pesticide impacts on populations is creating a need for risk assessment tools that capture interactions between life histories and sp...
Threatened and endangered species are increasingly impacted by agricultural pesticides. Interest in developing regulatory approaches that address pesticide impacts on populations is creating a need for risk assessment tools that capture interactions between life histories and sp...
The Relationship between Assertiveness and College Satisfaction in a Multicultural Population.
ERIC Educational Resources Information Center
Abston, Nathaniel, Jr.; Wesley, Andrea L.
The changing ethnic population of college students presents a need to assess college satisfaction, particularly in view of the increasing numbers of black students attending predominantly white colleges and universities. The relationship between assertiveness and college satisfaction was studied in a multicultural population of 23 black and 23…
Rural-Urban Migration in Colombia.
ERIC Educational Resources Information Center
Schultz, T. Paul
The rural-urban migration pattern in Colombia during the last 25 years has resulted in a population increase in urban areas from 30 to 52 percent of the total population. This study explores the causes of internal migration. Migration rates are estimated for various groups in the population to clarify who migrates and to where. A model of…
Epidemiologic and experimental studies have demonstrated a variety of health effects in response to ozone (O3) exposure. Studies have demonstrated that some populations may be at increased risk of O3-related health effects. Objectives: To identify populations and lifestages pote...
Evangelista, Charlotte; Britton, Robert J; Cucherousset, Julien
2015-06-01
Exploitation can modify the characteristics of fish populations through the selective harvesting of individuals, with this potentially leading to rapid ecological and evolutionary changes. Despite the well-known effects of invasive fishes on aquatic ecosystems generally, the potential effects of their selective removal through angling, a strategy commonly used to manage invasive fish, are poorly understood. The aim of this field-based study was to use the North American pumpkinseed Lepomis gibbosus as the model species to investigate the consequences of selective removal on their population characteristics and juvenile growth rates across 10 populations in artificial lakes in southern France. We found that the maximal individual mass in populations decreased as removal pressure through angling increased, whereas we did not observed any changes in the maximal individual length in populations as removal pressure increased. Total population abundance did not decrease as removal pressure increased; instead, here was a U-shaped relationship between removal pressure and the abundance of medium-bodied individuals. In addition, population biomass had a U-shaped curve response to removal pressure, implying that invasive fish populations can modulate their characteristics to compensate for the negative effects of selective removals. In addition, individual lengths at age 2 and juvenile growth rates decreased as removal pressure through angling increased, suggesting a shift toward an earlier size at maturity and an overall slower growing phenotype. Therefore, these outputs challenge the efficiency of selective management methods, suggesting the use of more proactive strategies to control invasive populations, and the need to investigate the potential ecological and evolutionary repercussions of nonrandom removal.
Evangelista, Charlotte; Britton, Robert J; Cucherousset, Julien
2015-01-01
Exploitation can modify the characteristics of fish populations through the selective harvesting of individuals, with this potentially leading to rapid ecological and evolutionary changes. Despite the well-known effects of invasive fishes on aquatic ecosystems generally, the potential effects of their selective removal through angling, a strategy commonly used to manage invasive fish, are poorly understood. The aim of this field-based study was to use the North American pumpkinseed Lepomis gibbosus as the model species to investigate the consequences of selective removal on their population characteristics and juvenile growth rates across 10 populations in artificial lakes in southern France. We found that the maximal individual mass in populations decreased as removal pressure through angling increased, whereas we did not observed any changes in the maximal individual length in populations as removal pressure increased. Total population abundance did not decrease as removal pressure increased; instead, here was a U-shaped relationship between removal pressure and the abundance of medium-bodied individuals. In addition, population biomass had a U-shaped curve response to removal pressure, implying that invasive fish populations can modulate their characteristics to compensate for the negative effects of selective removals. In addition, individual lengths at age 2 and juvenile growth rates decreased as removal pressure through angling increased, suggesting a shift toward an earlier size at maturity and an overall slower growing phenotype. Therefore, these outputs challenge the efficiency of selective management methods, suggesting the use of more proactive strategies to control invasive populations, and the need to investigate the potential ecological and evolutionary repercussions of nonrandom removal. PMID:26078856
Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations?
Kannus, Pekka; Niemi, Seppo; Parkkari, Jari; Palvanen, Mika; Heinonen, Ari; Sievänen, Harri; Järvinen, Teppo; Khan, Karim; Järvinen, Markku
2002-08-01
Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones.
Air pollution and health risks due to vehicle traffic.
Zhang, Kai; Batterman, Stuart
2013-04-15
Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed-volume relationship, the California Line Source Dispersion Model, an empirical NO2-NOx relationship, estimated travel time changes during congestion, and concentration-response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, "U" shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2-NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must consider travel time, the duration of rush-hour, congestion-specific emission estimates, and uncertainties. Copyright © 2013 Elsevier B.V. All rights reserved.
Air pollution and health risks due to vehicle traffic
Zhang, Kai; Batterman, Stuart
2014-01-01
Traffic congestion increases vehicle emissions and degrades ambient air quality, and recent studies have shown excess morbidity and mortality for drivers, commuters and individuals living near major roadways. Presently, our understanding of the air pollution impacts from congestion on roads is very limited. This study demonstrates an approach to characterize risks of traffic for on- and near-road populations. Simulation modeling was used to estimate on- and near-road NO2 concentrations and health risks for freeway and arterial scenarios attributable to traffic for different traffic volumes during rush hour periods. The modeling used emission factors from two different models (Comprehensive Modal Emissions Model and Motor Vehicle Emissions Factor Model version 6.2), an empirical traffic speed–volume relationship, the California Line Source Dispersion Model, an empirical NO2–NOx relationship, estimated travel time changes during congestion, and concentration–response relationships from the literature, which give emergency doctor visits, hospital admissions and mortality attributed to NO2 exposure. An incremental analysis, which expresses the change in health risks for small increases in traffic volume, showed non-linear effects. For a freeway, “U” shaped trends of incremental risks were predicted for on-road populations, and incremental risks are flat at low traffic volumes for near-road populations. For an arterial road, incremental risks increased sharply for both on- and near-road populations as traffic increased. These patterns result from changes in emission factors, the NO2–NOx relationship, the travel delay for the on-road population, and the extended duration of rush hour for the near-road population. This study suggests that health risks from congestion are potentially significant, and that additional traffic can significantly increase risks, depending on the type of road and other factors. Further, evaluations of risk associated with congestion must consider travel time, the duration of rush-hour, congestion-specific emission estimates, and uncertainties. PMID:23500830
Does childhood cancer affect parental divorce rates? A population-based study.
Syse, Astri; Loge, Jon H; Lyngstad, Torkild H
2010-02-10
PURPOSE Cancer in children may profoundly affect parents' personal relationships in terms of psychological stress and an increased care burden. This could hypothetically elevate divorce rates. Few studies on divorce occurrence exist, so the effect of childhood cancers on parental divorce rates was explored. PATIENTS AND METHODS Data on the entire Norwegian married population, age 17 to 69 years, with children age 0 to 20 years in 1974 to 2001 (N = 977,928 couples) were retrieved from the Cancer Registry, the Central Population Register, the Directorate of Taxes, and population censuses. Divorce rates for 4,590 couples who were parenting a child with cancer were compared with those of otherwise similar couples by discrete-time hazard regression models. Results Cancer in a child was not associated with an increased risk of parental divorce overall. An increased divorce rate was observed with Wilms tumor (odds ratio [OR], 1.52) but not with any of the other common childhood cancers. The child's age at diagnosis, time elapsed from diagnosis, and death from cancer did not influence divorce rates significantly. Increased divorce rates were observed for couples in whom the mothers had an education greater than high school level (OR, 1.16); the risk was particularly high shortly after diagnosis, for CNS cancers and Wilms tumors, for couples with children 0 to 9 years of age at diagnosis, and after a child's death. CONCLUSION This large, registry-based study shows that cancer in children is not associated with an increased parental divorce rate, except with Wilms tumors. Couples in whom the wife is highly educated appear to face increased divorce rates after a child's cancer, and this may warrant additional study.
Population based study of rates of multiple pregnancies in Denmark, 1980-94.
Westergaard, T.; Wohlfahrt, J.; Aaby, P.; Melbye, M.
1997-01-01
OBJECTIVE: To study trends in multiple pregnancies not explained by changes in maternal age and parity patterns. DESIGN: Trends in population based figures for multiple pregnancies in Denmark studied from complete national records on parity history and vital status. POPULATION: 497,979 Danish women and 803,019 pregnancies, 1980-94. MAIN OUTCOME MEASURES: National rates of multiple pregnancies, infant mortality, and stillbirths controlled for maternal age and parity. Special emphasis on primiparous women > or = 30 years of age, who are most likely to undergo fertility treatment. RESULTS: The national incidence of multiple pregnancies increased 1.7-fold during 1980-94, the increase primarily in 1989-94 and almost exclusively in primiparous women aged > or = 30 years, for whom the adjusted population based twinning rate increased 2.7-fold and the triplet rate 9.1-fold. During 1989-94, the adjusted yearly increase in multiple pregnancies for these women was 19% (95% confidence interval 16% to 21%) and in dizygotic twin pregnancies 25% (21% to 28%). The proportion of multiple births among infant deaths in primiparous women > or = 30 years increased from 11.5% to 26.9% during the study period. The total infant mortality, however, did not increase for these women because of a simultaneous significant decrease in infant mortality among singletons. CONCLUSIONS: A relatively small group of women has drastically changed the overall national rates of multiple pregnancies. The introduction of new treatments to enhance fertility has probably caused these changes and has also affected the otherwise decreasing trend in infant mortality. Consequently, the resources, both economical and otherwise, associated with these treatments go well beyond those invested in specific fertility enhancing treatments. PMID:9080993
Crespi, Catherine M; Vergara, Ximena P; Hooper, Chris; Oksuzyan, Sona; Wu, Sheng; Cockburn, Myles; Kheifets, Leeka
2016-06-28
Studies have reported an increased risk of childhood leukaemia associated with living near high-voltage electric power transmission lines that extend to distances at which magnetic fields from lines are negligible. We conducted a large records-based case-control study of childhood leukaemia risk in the population living near power lines in California. The study included 5788 childhood leukaemia and 3308 central nervous system (CNS) cancer cases (for comparison) born in and diagnosed in California (1986-2008), and matched to population-based controls by age and sex. We geocoded birth address and estimated the distance from residence to transmission lines using geographic information systems, aerial imagery, and, for some residences, site visits. For leukaemia, there was a slight excess of cases within 50 m of a transmission line over 200 kV (odds ratio 1.4, 95% confidence interval 0.7-2.7). There was no evidence of increased risk for distances beyond 50 m, for lower-voltage lines, or for CNS cancers. Our findings did not clearly support an increased childhood leukaemia risk associated with close proximity (<50 m) to higher voltage lines, but could be consistent with a small increased risk. Reports of increased risk for distances beyond 50 m were not replicated.
Santric-Milicevic, M; Vasic, V; Terzic-Supic, Z
2016-08-15
In times of austerity, the availability of econometric health knowledge assists policy-makers in understanding and balancing health expenditure with health care plans within fiscal constraints. The objective of this study is to explore whether the health workforce supply of the public health care sector, population number, and utilization of inpatient care significantly contribute to total health expenditure. The dependent variable is the total health expenditure (THE) in Serbia from the years 2003 to 2011. The independent variables are the number of health workers employed in the public health care sector, population number, and inpatient care discharges per 100 population. The statistical analyses include the quadratic interpolation method, natural logarithm and differentiation, and multiple linear regression analyses. The level of significance is set at P < 0.05. The regression model captures 90 % of all variations of observed dependent variables (adjusted R square), and the model is significant (P < 0.001). Total health expenditure increased by 1.21 standard deviations, with an increase in health workforce growth rate by 1 standard deviation. Furthermore, this rate decreased by 1.12 standard deviations, with an increase in (negative) population growth rate by 1 standard deviation. Finally, the growth rate increased by 0.38 standard deviation, with an increase of the growth rate of inpatient care discharges per 100 population by 1 standard deviation (P < 0.001). Study results demonstrate that the government has been making an effort to control strongly health budget growth. Exploring causality relationships between health expenditure and health workforce is important for countries that are trying to consolidate their public health finances and achieve universal health coverage at the same time.
Pritchard, C; Evans, B
1997-07-01
The aetiology of malignant disease is multi-factorial, including contributory environmental factors. Based upon the premise that increases in the density of population will be coterminous with a worsening of the environment, it is hypothesised that such changes should be reflected in an increase in cancer mortality in general and in elderly populations. By focusing upon changes in the elderly (+75) deaths between two time periods, the study corrects for age factors related to cancer mortality. The study tests this hypothesis via correlations between population density and malignancy death rates in general and elderly age bands over a thirty year period. It was found that there were positive and significant correlations between population density and malignancy mortality rates in the Western World, especially amongst men, but all correlations strengthened in the direction hypothesised. The findings were not an artefact of longevity, further research is required to give a better understanding of these findings.
Hatzenbuehler, Mark L; McLaughlin, Katie A; Keyes, Katherine M; Hasin, Deborah S
2010-03-01
We examined the relation between living in states that instituted bans on same-sex marriage during the 2004 and 2005 elections and the prevalence of psychiatric morbidity among lesbian, gay, and bisexual (LGB) populations. We used data from wave 1 (2001-2002) and wave 2 (2004-2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (N = 34,653), a longitudinal, nationally representative study of noninstitutionalized US adults. Psychiatric disorders defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, increased significantly between waves 1 and 2 among LGB respondents living in states that banned gay marriage for the following outcomes: any mood disorder (36.6% increase), generalized anxiety disorder (248.2% increase), any alcohol use disorder (41.9% increase), and psychiatric comorbidity (36.3% increase). These psychiatric disorders did not increase significantly among LGB respondents living in states without constitutional amendments. Additionally, we found no evidence for increases of the same magnitude among heterosexuals living in states with constitutional amendments. Living in states with discriminatory policies may have pernicious consequences for the mental health of LGB populations. These findings lend scientific support to recent efforts to overturn these policies.
Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum
Rico, Y; Wagner, H H
2016-01-01
Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations. PMID:27381322
Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum.
Rico, Y; Wagner, H H
2016-11-01
Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations.
Ward, Megan; Johnson, Steven D; Zalucki, Myron P
2013-04-01
One of the essential requirements for an introduced plant species to become invasive is an ability to reproduce outside the native range, particularly when initial populations are small. If a reproductive Allee effect is operating, plants in small populations will have reduced reproductive success relative to plants in larger populations. Alternatively, if plants in small populations experience less competition for pollination than those in large populations, they may actually have higher levels of reproductive success than plants in large populations. To resolve this uncertainty, we investigated how the per capita fecundity of plants was affected by population size in three invasive milkweed species. Field surveys of seed production in natural populations of different sizes but similar densities were conducted for three pollinator-dependent invasive species, namely Asclepias curassavica, Gomphocarpus fruticosus and G. physocarpus. Additionally, supplemental hand-pollinations were performed in small and large populations in order to determine whether reproductive output was limited by pollinator activity in these populations. Reproductive Allee effects were not detected in any of the study species. Instead, plants in small populations exhibited remarkably high levels of reproductive output compared to those in large populations. Increased fruit production following supplemental hand-pollinations suggested that the lower reproductive output of naturally pollinated plants in large populations is a consequence of pollen limitation rather than limitation due to abiotic resources. This is consistent with increased intraspecific competition for pollination amongst plants in large populations. It is likely that the invasion of these milkweed species in Australia has been enhanced because plants in small founding populations experience less intraspecific competition for pollinators than those in large populations, and thus have the ability to produce copious amounts of seeds.
Tiwari, Siddharth; Killiny, Nabil; Stelinski, Lukasz L
2013-02-01
Five field populations of Diaphorina citri Kuwayama from various regions of Florida were evaluated in 2011 for resistance to commonly used insecticides. Three diagnostic doses (LD50, LD75, and LD95), developed in 2009 using a laboratory susceptible population, were used to measure changes in susceptibility levels of field-collected populations as compared with a susceptible laboratory population. Further reductions in the susceptibility levels of D. citri to chlorpyriphos and fenpropathrin were determined, compared with results obtained in 2010. Mean percent mortality obtained from all five locations was significantly lower than observed with the laboratory susceptible population for all insecticides tested. Previously, expression of five CYP4 genes was implicated in contributing to insecticide metabolism in D. citri. In the current study, we compared the relative expression of these five CYP4 genes and their associated levels of protein expression among field-collected and laboratory susceptible populations. Expression of all CYP4 genes investigated was higher in field-collected populations when normalized against the laboratory susceptible population. There was an increased signal of a band corresponding to a 45 kDa protein in four of the five field populations as measured by the Western blot assay, which suggests increased production of cytochrome P450 enzymes. The current results indicate that insecticide resistance continues to increase in Florida populations ofD. citri, particularly to chlorpyriphos and fenpropathrin. However, there was no further decrease in susceptibility of Florida populations of D. citri to neonicotinoid insecticides in 2011 as compared with previous years.
High mutation rates limit evolutionary adaptation in Escherichia coli
Wagner, Andreas
2018-01-01
Mutation is fundamental to evolution, because it generates the genetic variation on which selection can act. In nature, genetic changes often increase the mutation rate in systems that range from viruses and bacteria to human tumors. Such an increase promotes the accumulation of frequent deleterious or neutral alleles, but it can also increase the chances that a population acquires rare beneficial alleles. Here, we study how up to 100-fold increases in Escherichia coli’s genomic mutation rate affect adaptive evolution. To do so, we evolved multiple replicate populations of asexual E. coli strains engineered to have four different mutation rates for 3000 generations in the laboratory. We measured the ability of evolved populations to grow in their original environment and in more than 90 novel chemical environments. In addition, we subjected the populations to whole genome population sequencing. Although populations with higher mutation rates accumulated greater genetic diversity, this diversity conveyed benefits only for modestly increased mutation rates, where populations adapted faster and also thrived better than their ancestors in some novel environments. In contrast, some populations at the highest mutation rates showed reduced adaptation during evolution, and failed to thrive in all of the 90 alternative environments. In addition, they experienced a dramatic decrease in mutation rate. Our work demonstrates that the mutation rate changes the global balance between deleterious and beneficial mutational effects on fitness. In contrast to most theoretical models, our experiments suggest that this tipping point already occurs at the modest mutation rates that are found in the wild. PMID:29702649
Koizumi, Kazuki; Kawanai, Takuya; Hashimoto, Erika; Kanbara, Yasuhiro; Masuda, Toshiya; Kanemaru, Kaori; Okano, Yoshiro; Oyama, Yasuo
2011-06-01
Curcumin exhibits various pharmacological actions including anti-inflammatory, anti-infectious, and anticancer actions. Furthermore, the supplements containing curcumin are supplied for persons consuming alcoholic beverage. A primary criterion for an ingredient ingested by general population is that it exerts no harmful effect. In this study, we examined the effect of curcumin on rat thymocytes to see if curcumin exerts cytotoxicity on normal cells. The incubation with 10 μM curcumin for 24h increased the population of dead cells while it was not the case for 5 μM or less. Curcumin at 5-10 μM increased the populations of shrunken cells and the cells positive to annexin V, phenomena for early stage of apoptosis. However, the incubation with 10 μM curcumin suppressed the increase in population of cells with hypodiploid DNA, a phenomenon for late stage of apoptosis. Thus, curcumin at 10 μM may show both proapoptotic and antiapoptotic actions. The simultaneous incubation with 5 μM, but not 3 μM, curcumin and 0.5% ethanol increased the population of shrunken cells. It is likely that curcumin at 5 μM or more exerts cytotoxic action on normal cells although many studies show some anticancer actions of curcumin at 10 μM or more on cancer cells. Copyright © 2011 Elsevier Ltd. All rights reserved.
Cardiac calcification in renal patients: what we do and don't know.
Hujairi, Nabil M A; Afzali, Behdad; Goldsmith, David J A
2004-02-01
Cardiovascular (CV) disease is one of the major causes of mortality in patients with renal diseases, with an increased odds ratio of mortality with risk factors as diverse as blood pressure (high or low), cholesterol level (high or low), left ventricular hypertrophy, vascular stiffness, chronic inflammation, and hyperhomocysteinemia. Mainly cross-sectional studies of renal patients showed excess CV calcification (CVC) compared with the general population, but a clear link between calcification and subsequent mortality is tenuous to date. Several factors have been incriminated to explain the increase in CVC in this particular population. Increased duration of dialysis therapy, dyslipidemia, altered calcium-phosphorus metabolism, and chronic inflammation have all been associated with increased CVC. However, with the shortage of large, observational, population-based, prospective studies tracking these potential risk factors and the pathogenesis of CVC in renal patients not yet sufficiently understood, it is difficult with the present state of knowledge to make robust recommendations about care strategies. The purpose of this review is to examine the 10 available studies of renal patients that have used modern CVC imaging and quantification techniques for clues to likely targets for future interventional studies.
Influence of Temperature on Population Development of Eight Species of Pratylenchus on Soybean
Acosta, Nelia; Malek, R. B.
1979-01-01
In a soil temperature study, population increase on 'Clark 63' soybeatt was most rapid at 30 C in Pratylenchus alleni, P. brachyurus, P. cofleae, P. neglectus, P. scribneri, and P. zeae and at 25 C in P. penetrans and P. vulnus. The last two were the only species that reproduced at 15 C. Populations of all species increased over the range of 20-30 C, except those of P. neglectus at 20 C and P. coffeae, which was not tested below 25 C. Only P. brachyurus, P. neglectus, P. scribneri and P. zeae reproduced at 35 C. At their optimum temperatures, P. scribneri exhibited the greatest population increase, 1248-fold, and P. penetrans the least, 32-fold. This is the first report of soybean as a host for P. vulnus. PMID:19300639
DOE Office of Scientific and Technical Information (OSTI.GOV)
Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com; Mahasakpan, Pranee; Limpatanachote, Pisit
Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinarymore » excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: {yields} Excessive calciuria is the major risk of urinary stone formation. {yields} We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. {yields} The rate of urinary stones increases with increasing urinary cadmium. {yields} Urinary calcium excretion increases with increasing urinary cadmium. {yields} Elevated calciuria induced by cadmium may increase the risk of urinary stones.« less
Suo, Zhenhe; Munthe, Else; Solberg, Steinar; Ma, Liwei; Wang, Mengyu; Westerdaal, Nomdo Anton Christiaan; Kvalheim, Gunnar; Gaudernack, Gustav
2013-01-01
Lung cancer (LC) with its different subtypes is generally known as a therapy resistant cancer with the highest morbidity rate worldwide. Therapy resistance of a tumor is thought to be related to cancer stem cells (CSCs) within the tumors. There have been indications that the lung cancer is propagated and maintained by a small population of CSCs. To study this question we established a panel of 15 primary lung cancer cell lines (PLCCLs) from 20 fresh primary tumors using a robust serum-free culture system. We subsequently focused on identification of lung CSCs by studying these cell lines derived from 4 representative lung cancer subtypes such as small cell lung cancer (SCLC), large cell carcinoma (LCC), squamous cell carcinoma (SCC) and adenocarcinoma (AC). We identified a small population of cells strongly positive for CD44 (CD44high) and a main population which was either weakly positive or negative for CD44 (CD44low/−). Co-expression of CD90 further narrowed down the putative stem cell population in PLCCLs from SCLC and LCC as spheroid-forming cells were mainly found within the CD44highCD90+ sub-population. Moreover, these CD44highCD90+ cells revealed mesenchymal morphology, increased expression of mesenchymal markers N-Cadherin and Vimentin, increased mRNA levels of the embryonic stem cell related genes Nanog and Oct4 and increased resistance to irradiation compared to other sub-populations studied, suggesting the CD44highCD90+ population a good candidate for the lung CSCs. Both CD44highCD90+ and CD44highCD90− cells in the PLCCL derived from SCC formed spheroids, whereas the CD44low/− cells were lacking this potential. These results indicate that CD44highCD90+ sub-population may represent CSCs in SCLC and LCC, whereas in SCC lung cancer subtype, CSC potentials were found within the CD44high sub-population. PMID:23469181
Vogelmann, James E.
1995-01-01
Spatial patterns and rates of forest fragmentation were assessed using digital remote sensing data for a region in southern New England that included 157 townships in southern New Hampshire and northeastern Massachusetts. The study area has undergone marked population increases over the last several decades. Following classification of 1973 and 1988 Landsat Multispectral Scanner data into forest and nonforest classes, data were incorporated into a geographic information system. The natural logarithms of forest area to perimeter ratios, referred to as the forest continuity index, were used to assess patterns and trends of forest fragmentation across the region Forest continuity index values were extracted from each township for both data sets and compared with population data. Forest continuity index values were found to decrease with increasing population density until about 200 persons per square kilometer, after which the relationship stabilized. With slight population increases at low densities forest continuity index values declined sharply, implying abrupt increases in forest fragmentation. Results from the study indicated good negative correlations (r2 values of 0.81 and 0.77) between the Multispectral Scanner-derived forest continuity index and natural logs of township population density. Socioeconomic indicators such as affluence and commuting patterns did not appear to correlate well with forest fragmentation estimates. Decreases in forest continuity index values occurred throughout much of the study region between 1973 and 1988, suggesting that forest fragmentation is occurring over large regions within the eastern United States. It is technologically feasible to assess patterns and rates of forest fragmentation across much larger areas than analyzed in this study; such analyses would provide useful overviews enabling objective assessment of the magnitude of forest fragmentation.
Souma, Nao; Isakova, Tamara; Lipiszko, David; Sacco, Ralph L.; Elkind, Mitchell S. V.; DeRosa, Janet T.; Silverberg, Shonni J.; Mendez, Armando J.; Dong, Chuanhui
2016-01-01
Context: An elevated fibroblast growth factor (FGF) 23 is an independent risk factor for cardiovascular disease and mortality in patients with kidney disease. The relationship between FGF23 and cause-specific mortality in the general population is unknown. Objective: To investigate the association of elevated FGF23 with the risk of cause-specific mortality in a racially and ethnically diverse urban general population. Design, Setting, Participants: The Northern Manhattan Study is a population-based prospective cohort study. Residents who were > 39 years old and had no history of stroke were enrolled between 1993 and 2001. Participants with available blood samples for baseline FGF23 testing were included in the current study (n = 2525). Main Outcome Measures: Cause-specific death events. Results: A total of 1198 deaths (474 vascular, 612 nonvascular, 112 unknown cause) occurred during a median follow-up of 14 years. Compared to participants in the lowest FGF23 quintile, those in the highest quintile had a 2.07-fold higher risk (95% confidence interval [CI], 1.45, 2.94) of vascular death and a 1.64-fold higher risk (95% CI, 1.22, 2.20) of nonvascular death in fully adjusted models. Higher FGF23 was independently associated with increased risk of mortality due to cancer, but only in Hispanic participants (hazard ratio per 1 unit increase in ln FGF23 of 1.87; 95% CI, 1.40, 2.50; P for interaction = .01). Conclusions: Elevated FGF23 was independently associated with increased risk of vascular and nonvascular mortality in a diverse general population and with increased risk of cancer death specifically in Hispanic individuals. PMID:27501282
Epidemiology and Trends in Incidence of Kidney Cancer in Iran.
Mirzaei, Maryam; Pournamdar, Zahra; Salehiniya, Hamid
2015-01-01
Kidney cancer has shown an increasing trend in recent decades. This study aimed to determine change in the incidence rate between 2003 and 2009 in Iran. In this study, national cancer registry data were used. Crude incidence rates were calculated per 100,000 and age-standardized incidence rates (ASRs) were computed using the direct standardization method and the world standard population. Significant trend of incidence rates was examined by the Cochran-Armitage test for linear trend. A total of 6,944 cases of kidney cancer were reported. The incidence cases increased from 595 patients in 2003 to 1,387 patients in 2009. Sex ratio (male to female) was 1.67. ASR also increased from 1.18 in 2003 to 2.52 in 2009 per 100,000, but the increasing trend was not significant. A slow increasing trend of incidence rate was observed in the study population. This may be due to an increase of risk factors. It is suggested to perform a study on risk factors for the cancer.
Brassine, Eléanor; Parker, Daniel
2015-01-01
Camera trapping studies have become increasingly popular to produce population estimates of individually recognisable mammals. Yet, monitoring techniques for rare species which occur at extremely low densities are lacking. Additionally, species which have unpredictable movements may make obtaining reliable population estimates challenging due to low detectability. Our study explores the effectiveness of intensive camera trapping for estimating cheetah (Acinonyx jubatus) numbers. Using both a more traditional, systematic grid approach and pre-determined, targeted sites for camera placement, the cheetah population of the Northern Tuli Game Reserve, Botswana was sampled between December 2012 and October 2013. Placement of cameras in a regular grid pattern yielded very few (n = 9) cheetah images and these were insufficient to estimate cheetah density. However, pre-selected cheetah scent-marking posts provided 53 images of seven adult cheetahs (0.61 ± 0.18 cheetahs/100km²). While increasing the length of the camera trapping survey from 90 to 130 days increased the total number of cheetah images obtained (from 53 to 200), no new individuals were recorded and the estimated population density remained stable. Thus, our study demonstrates that targeted camera placement (irrespective of survey duration) is necessary for reliably assessing cheetah densities where populations are naturally very low or dominated by transient individuals. Significantly our approach can easily be applied to other rare predator species. PMID:26698574
Brassine, Eléanor; Parker, Daniel
2015-01-01
Camera trapping studies have become increasingly popular to produce population estimates of individually recognisable mammals. Yet, monitoring techniques for rare species which occur at extremely low densities are lacking. Additionally, species which have unpredictable movements may make obtaining reliable population estimates challenging due to low detectability. Our study explores the effectiveness of intensive camera trapping for estimating cheetah (Acinonyx jubatus) numbers. Using both a more traditional, systematic grid approach and pre-determined, targeted sites for camera placement, the cheetah population of the Northern Tuli Game Reserve, Botswana was sampled between December 2012 and October 2013. Placement of cameras in a regular grid pattern yielded very few (n = 9) cheetah images and these were insufficient to estimate cheetah density. However, pre-selected cheetah scent-marking posts provided 53 images of seven adult cheetahs (0.61 ± 0.18 cheetahs/100 km²). While increasing the length of the camera trapping survey from 90 to 130 days increased the total number of cheetah images obtained (from 53 to 200), no new individuals were recorded and the estimated population density remained stable. Thus, our study demonstrates that targeted camera placement (irrespective of survey duration) is necessary for reliably assessing cheetah densities where populations are naturally very low or dominated by transient individuals. Significantly our approach can easily be applied to other rare predator species.
Methodology for the evaluation of vascular surgery manpower in France.
Berger, L; Mace, J M; Ricco, J B; Saporta, G
2013-01-01
The French population is growing and ageing. It is expected to increase by 2.7% by 2020, and the number of individuals over 65 years of age is expected to increase by 3.3 million, a 33% increase, between 2005 and 2020. As the number of vascular surgery procedures is closely associated with the age of a population, it is anticipated that there will be a significant increase in the workload of vascular surgeons. A model is presented to predict changes in vascular surgery activity according to population ageing, including other parameters that could affect workload evolution. Three types of arterial procedures were studied: infrarenal abdominal aortic aneurysm (AAA) surgery, peripheral arterial occlusive disease (PAOD) procedures and carotid artery (CEA) procedures. Data were selected and extracted from the national PMSI (Medical Information System Program) database. Data obtained from 2000 were used to predict data based on an ageing population for 2008. From this model, a weighted index was defined for each group by comparing expected and observed workloads. According to the model, over this 8-year period, there was an overall increase in vascular procedures of 52.2%, with an increase of 89% in PAOD procedures. Between 2000 and 2009, the total increase was 58.0%, with 3.9% for AAA procedures, 101.7% for PAOD procedures and 13.2% for CEA procedures. The weighted model based on an ageing population and corrected by a weighted factor predicted this increase. This weighted model is able to predict the workload of vascular surgeons over the coming years. An ageing population and other factors could result in a significant increase in demand for vascular surgical services. Copyright © 2012 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.
Gross, C L; Mackay, D
2014-07-01
Olearia flocktoniae is an endangered shrub that was passively translocated from its natural ecosystem, where it has since gone extinct. This study aimed to determine sensitivities vital to populations persisting in human-created areas. Population colonization, longevity and extinction were investigated over 20 years using 133 populations. Seed-bank longevity was determined from germination trials of seeds exhumed from extinct and extant sites via a 10-year glasshouse trial and by in situ sowing experiments. 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) with different disturbance histories were used to evaluate sensitivities in vital rates. Most populations had few individuals (∼30) and were transient (<5 years above ground). The intrinsic population growth rate was rarely >1 and all but two populations were extinct at year 20. Seeds were short-lived in situ. Although >1000 seeds per plant were produced annually in most populations, sensitivity analysis showed that the transition to the seed bank and the transition from the seed bank to seedlings are key vulnerabilities in the life-cycle. Seedling establishment is promoted by recent disturbance. Increasing the number of disturbance events in populations, even severe disturbances that almost extirpate populations, significantly increases longer-term population persistence. Only populations that were disturbed annually survived the full 20 years of the study. The results show that translocated populations of O. flocktoniae will fail to persist without active management. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company.
A case-control study: occupational cooking and the risk of uveal melanoma
2010-01-01
Background A European-wide population based case-control study (European rare cancer study) undertaken in nine European countries examined risk factors for uveal melanoma. They found a positive association between cooks and the risk of uveal melanoma. In our study we examine whether cooks or people who worked in cook related jobs have an increased uveal melanoma risk. Methods We conducted a case-control study during 2002 and 2005. Overall, 1653 eligible subjects (age range: 20-74 years, living in Germany) participated. Interviews were conducted with 459 incident uveal melanoma cases, 827 population controls, 180 ophthalmologist controls and 187 sibling controls. Data on occupational exposure were obtained from a self-administered postal questionnaire and a computer-assisted telephone interview. We used conditional logistic regression to estimate odds ratios adjusting for the matching factors. Results Overall, we did not observe an increased risk of uveal melanoma among people who worked as cooks or who worked in cook related jobs. When we restricted the source population of our study to the population of the Federal State of Northrhine-Westphalia, we observed an increased risk among subjects who were categorized as cooks in the cases-control analysis. Conclusion Our results are in conflict with former results of the European rare cancer study. Considering the rarity of the disease laboratory in vitro studies of human uveal melanoma cell lines should be done to analyze potential exposure risk factors like radiation from microwaves, strong light from incandescent ovens, or infrared radiation. PMID:20969762
Risk of Dementia Associated with Elevated Plasma Homocysteine in a Latin American Population
Chacón, Inara J.; Molero, Aldrín E.; Pino-Ramírez, Gloria; Luchsinger, José A.; Lee, Joseph H.; Maestre, Gladys E.
2009-01-01
The relationship between total homocysteine (tHcy) and dementia risk remains controversial, as the association varies among populations and dementia subtypes. We studied a Venezuelan population that has high prevalence of both elevated tHcy and dementia. We tested the hypotheses that (1) elevated tHcy is associated with increased dementia risk, (2) the risk is greater for vascular dementia (VaD) than for Alzheimer's disease (AD), and (3) a history of stroke may partly explain this association. 2100 participants (≥55 years old) of the Maracaibo Aging Study underwent standardized neurological, neuropsychiatric, and cardiovascular assessments. Elevated tHcy was significantly associated with dementia, primarily VaD. When history of stroke and other confounding factors were taken into account, elevated tHcy remained a significant risk factor in older (>66 years), but not in younger (55–66 years) subjects. Ongoing studies of this population may provide insight into the mechanism by which tHcy increases risk for dementia. PMID:20798752
Haq, Ihsan ul; Vreysen, Marc J. B.; Schutze, Mark; Hendrichs, Jorge; Shelly, Todd
2016-01-01
Males of some species included in the Bactrocera dorsalis complex are strongly attracted to methyl eugenol (ME) (1,2-dimethoxy-4-(2-propenyl) benzene), a natural compound occurring in a variety of plant species. ME feeding of males of the B. dorsalis complex is known to enhance their mating competitiveness. Within B. dorsalis, recent studies show that Asian and African populations of B. dorsalis are sexually compatible, while populations of B. dorsalis and Bactrocera carambolae are relatively incompatible. The objectives of this study were to examine whether ME feeding by males affects mating compatibility between Asian and African populations of B. dorsalis and ME feeding reduces male mating incompatibility between B. dorsalis (Asian population) and B. carambolae. The data confirmed that Asian and African populations of B. dorsalis are sexually compatible for mating and showed that ME feeding only increased the number of matings. Though ME feeding also increased the number of matings of B. dorsalis (Asian population) and B. carambolae males but the sexual incompatibility between both species was not reduced by treatment with ME. These results conform to the efforts resolving the biological species limits among B. dorsalis complex and have implications for fruit fly control programs in fields and horticultural trade. PMID:26362991
Genetic rescue in an inbred Arctic fox (Vulpes lagopus) population.
Hasselgren, Malin; Angerbjörn, Anders; Eide, Nina E; Erlandsson, Rasmus; Flagstad, Øystein; Landa, Arild; Wallén, Johan; Norén, Karin
2018-03-28
Isolation of small populations can reduce fitness through inbreeding depression and impede population growth. Outcrossing with only a few unrelated individuals can increase demographic and genetic viability substantially, but few studies have documented such genetic rescue in natural mammal populations. We investigate the effects of immigration in a subpopulation of the endangered Scandinavian arctic fox ( Vulpes lagopus ), founded by six individuals and isolated for 9 years at an extremely small population size. Based on a long-term pedigree (105 litters, 543 individuals) combined with individual fitness traits, we found evidence for genetic rescue. Natural immigration and gene flow of three outbred males in 2010 resulted in a reduction in population average inbreeding coefficient ( f ), from 0.14 to 0.08 within 5 years. Genetic rescue was further supported by 1.9 times higher juvenile survival and 1.3 times higher breeding success in immigrant first-generation offspring compared with inbred offspring. Five years after immigration, the population had more than doubled in size and allelic richness increased by 41%. This is one of few studies that has documented genetic rescue in a natural mammal population suffering from inbreeding depression and contributes to a growing body of data demonstrating the vital connection between genetics and individual fitness. © 2018 The Author(s).
Galvão, K S C; Ramos, H C C; Santos, P H A D; Entringer, G C; Vettorazzi, J C F; Pereira, M G
2015-07-03
This study aimed to improve grain yield in the full-sib reciprocal recurrent selection program of maize from the North Fluminense State University. In the current phase of the program, the goal is to maintain, or even increase, the genetic variability within and among populations, in order to increase heterosis of the 13th cycle of reciprocal recurrent selection. Microsatellite expressed sequence tags (EST-SSRs) were used as a tool to assist the maximization step of genetic variability, targeting the functional genome. Eighty S1 progenies of the 13th recur-rent selection cycle, 40 from each population (CIMMYT and Piranão), were analyzed using 20 EST-SSR loci. Genetic diversity, observed heterozygosity, information content of polymorphism, and inbreeding co-efficient were estimated. Subsequently, analysis of genetic dissimilarity, molecular variance, and a graphical dispersion of genotypes were conducted. The number of alleles in the CIMMYT population ranged from 1 to 6, while in the Piranão population the range was from 2 to 8, with a mean of 3.65 and 4.35, respectively. As evidenced by the number of alleles, the Shannon index showed greater diversity for the Piranão population (1.04) in relation to the CIMMYT population (0.89). The genic SSR markers were effective in clustering genotypes into their respective populations before selection and an increase in the variation between populations after selection was observed. The results indicate that the study populations have expressive genetic diversity, which cor-responds to the functional genome, indicating that this strategy may contribute to genetic gain, especially in association with the grain yield of future hybrids.
Arbuthnott, Katherine G; Hajat, Shakoor
2017-12-05
It is widely acknowledged that the climate is warming globally and within the UK. In this paper, studies which assess the direct impact of current increased temperatures and heat-waves on health and those which project future health impacts of heat under different climate change scenarios in the UK are reviewed.This review finds that all UK studies demonstrate an increase in heat-related mortality occurring at temperatures above threshold values, with respiratory deaths being more sensitive to heat than deaths from cardiovascular disease (although the burden from cardiovascular deaths is greater in absolute terms). The relationship between heat and other health outcomes such as hospital admissions, myocardial infarctions and birth outcomes is less consistent. We highlight the main populations who are vulnerable to heat. Within the UK, these are older populations, those with certain co-morbidities and those living in Greater London, the South East and Eastern regions.In all assessments of heat-related impacts using different climate change scenarios, deaths are expected to increase due to hotter temperatures, with some studies demonstrating that an increase in the elderly population will also amplify burdens. However, key gaps in knowledge are found in relation to how urbanisation and population adaptation to heat will affect health impacts, and in relation to current and future strategies for effective, sustainable and equitable adaptation to heat. These and other key gaps in knowledge, both in terms of research needs and knowledge required to make sound public- health policy, are discussed.
Human and cattle population changes in deltaic West Bengal, India between 1977-1987
DOE Office of Scientific and Technical Information (OSTI.GOV)
Odend'hal, S.
1988-03-01
In 1967-1970, 3.81 km/sup 2/ of a densely populated deltaic area of Hooghly district in West Bengal, India was intensively studied. This same area was resurveyed in 1977 and 1987. From 1977-1987, the human population has increased 10.1%, while the number of households has increased 25%. The total number of children below 10 years of age has diminished. The cattle have increased 26.5%. The number of working-age male cattle has dropped significantly with reliance, primarily on hand tractor power for field cultivation. The number of female cattle has increased substantially. Artificial insemination and the use of temperate breeds of bullsmore » have had an obvious impact. Improvements in the general environment were observed.« less
Island Economic Vulnerability to Natural Disasters—the case of Changdao
NASA Astrophysics Data System (ADS)
Zhang, Z.
2016-12-01
The paper take Changdao County as sample to analyze differentiated impacts of natural disasters on island counties. The result shows that under increased population densities, small islands quickly face binding size limitations and suffer diminished per-capita resources from sustained population increases. The isolated, high-risk geography of small islands exacerbate the scale of a natural disaster shock, rendering many risk-pooling local mechanisms ineffective; disaster assistance flows were also shown to be ineffective in this study. In an environment of increasing weather hazards and resources at risk, it is imperative to understand the determinants of natural disaster vulnerability towards future loss mitigation. Importantly, disaster-thwarting polices must consider perverse implications of economic development measures, such as per-capita income, and infrastructure investments interacting with increased population densities.
Younossi, Zobair M; Stepanova, Maria
2011-10-01
Professional societies recommend hepatitis A and hepatitis B immunization for individuals with chronic liver disease (CLD), but the degree of implementation is unknown. Data were obtained from the National Health and Nutrition Examination Surveys (NHANES) conducted in 1999-2008. For the entire study population and for those with CLD and diabetes, we determined the rates and independent predictors of history of hepatitis A and hepatitis B (HepA and HepB) vaccinations, of their effectiveness, and of seroprevalence of hepatitis A antibody and anti-HB surface antibody. In total, 24,871 participants from NHANES were included: 14,886 (1999-2004) and 9,985 (2005-2008). Of these individuals, 14.0% had CLD and 8.6% had diabetes. During the study period, HepA vaccination in CLD increased from 13.3% ± 1.0% to 20.0% ± 1.5%, HepB vaccination increased from 23.4% ± 1.2% to 32.1% ± 1.5%. Of subtypes of CLD, HepA vaccination rates increased only in nonalcoholic fatty liver disease (NAFLD), whereas HepB vaccination increased for patients with hepatitis C and nonalcoholic fatty liver disease. In the diabetic cohort, HepA vaccination rates increased from 9.3% ± 1.1% to 15.4% ± 1.7% and HepB rates increased from 15.2% ± 1.5% to 22.4% ± 1.7%. All changes were similar to those observed in the general population. The quality measure (QM) for HepA in the general population decreased from 44.4% ± 1.2% in 1999-2004 to 41.7% ± 1.9% in 2005-2008, and similar changes were noted for all subcohorts. On the other hand, QM for HepB increased from 31.7% ± 0.9% to 40.7% ± 1.0% in the population, whereas no changes in QM were noted in any diagnostic cohort except for NAFLD. Although vaccination rates in CLD and diabetic cohorts are increasing, they remain low. Given the public health implications of acute hepatitis A and hepatitis B in patients with CLD, better implementation of the vaccination recommendations for these populations is warranted. Copyright © 2011 American Association for the Study of Liver Diseases.
de Pesters, A; Coon, W G; Brunner, P; Gunduz, A; Ritaccio, A L; Brunet, N M; de Weerd, P; Roberts, M J; Oostenveld, R; Fries, P; Schalk, G
2016-07-01
Performing different tasks, such as generating motor movements or processing sensory input, requires the recruitment of specific networks of neuronal populations. Previous studies suggested that power variations in the alpha band (8-12Hz) may implement such recruitment of task-specific populations by increasing cortical excitability in task-related areas while inhibiting population-level cortical activity in task-unrelated areas (Klimesch et al., 2007; Jensen and Mazaheri, 2010). However, the precise temporal and spatial relationships between the modulatory function implemented by alpha oscillations and population-level cortical activity remained undefined. Furthermore, while several studies suggested that alpha power indexes task-related populations across large and spatially separated cortical areas, it was largely unclear whether alpha power also differentially indexes smaller networks of task-related neuronal populations. Here we addressed these questions by investigating the temporal and spatial relationships of electrocorticographic (ECoG) power modulations in the alpha band and in the broadband gamma range (70-170Hz, indexing population-level activity) during auditory and motor tasks in five human subjects and one macaque monkey. In line with previous research, our results confirm that broadband gamma power accurately tracks task-related behavior and that alpha power decreases in task-related areas. More importantly, they demonstrate that alpha power suppression lags population-level activity in auditory areas during the auditory task, but precedes it in motor areas during the motor task. This suppression of alpha power in task-related areas was accompanied by an increase in areas not related to the task. In addition, we show for the first time that these differential modulations of alpha power could be observed not only across widely distributed systems (e.g., motor vs. auditory system), but also within the auditory system. Specifically, alpha power was suppressed in the locations within the auditory system that most robustly responded to particular sound stimuli. Altogether, our results provide experimental evidence for a mechanism that preferentially recruits task-related neuronal populations by increasing cortical excitability in task-related cortical areas and decreasing cortical excitability in task-unrelated areas. This mechanism is implemented by variations in alpha power and is common to humans and the non-human primate under study. These results contribute to an increasingly refined understanding of the mechanisms underlying the selection of the specific neuronal populations required for task execution. Copyright © 2016 Elsevier Inc. All rights reserved.
Olsen, Jonathan R; Mitchell, Richard; Ogilvie, David
2016-07-07
Promoting active travel is an important part of increasing population physical activity, which has both physical and mental health benefits. A key benefit described by the then Scottish Government of the five-mile M74 motorway extension, which opened during June 2011 in the south of Glasgow, was that the forecast reduction in motor traffic on local streets would make these streets safer for walking and cycling, thus increasing active travel by the local population. The aim of the study was to evaluate the impact of new motorway infrastructure on the proportion of journey stages made actively (cycling or on foot) by individuals travelling in and out of the local area. Data for the periods 2009-10 and 2012-13 were extracted from the Scottish Household Survey (SHS) travel diaries, which record each journey stage made during the previous day by a representative sample of the Scottish population aged 16 and over. Each individual journey stage was assigned to one of the following study areas surrounding existing and new transport infrastructure: (1) an area surrounding the new M74 motorway extension (n = 435 (2009-10), 543 (2012-13)), (2) a comparator area surrounding an existing motorway (n = 477 (2009-10), 560 (2012-13)), and (3) a control area containing no comparable motorway infrastructure (n = 541 (2009-10), 593 (2012-13)). Multivariable, multi-level regression analysis was performed to determine any between-area differences in change in active travel over time, which might indicate an intervention effect. Reference populations were defined using two alternative definitions, (1) Glasgow City and (2) Glasgow and surrounding local authorities. The results showed an increase in the proportion of journey stages using active travel in all study areas compared to both reference populations. However, there were no significant between-area differences to suggest an effect attributable the M74 motorway extension. There was no clear evidence that the M74 motorway extension either increased or decreased active travel in the local area. The anticipation by policy makers that reduced motorised traffic on local streets might increase journeys walked or cycled appears to have been unfounded.
Ogboghodo, I A; Oluwafemi, A P; Ekeh, S M
2006-05-01
The study was carried out to investigate the effects of application of cassava mill effluent on bacteria and fungi types and population in a soil grown to maize (Zea Mays L.) Microbial populations were determined before pollution of soil with cassava mill effluent, six weeks after pollution with effluent and at the end of the experiment. Results obtained showed that bacteria and fungi populations increased with time as rates of pollution increased. It was also observed that some bacteria present in the soil at the beginning of the experiment and up to the sixth week after pollution with effluent became extinct at the end of the experiment.
Reid, S.M.; Wilson, C.C.; Mandrak, N.E.; Carl, L.M.
2008-01-01
Dams have the potential to affect population size and connectivity, reduce genetic diversity, and increase genetic differences among isolated riverine fish populations. Previous research has reported adverse effects on the distribution and demographics of black redhorse (Moxostoma duquesnei), a threatened fish species in Canada. However, effects on genetic diversity and population structure are unknown. We used microsatellite DNA markers to assess the number of genetic populations in the Grand River (Ontario) and to test whether dams have resulted in a loss of genetic diversity and increased genetic differentiation among populations. Three hundred and seventy-seven individuals from eight Grand River sites were genotyped at eight microsatellite loci. Measures of genetic diversity were moderately high and not significantly different among populations; strong evidence of recent population bottlenecks was not detected. Pairwise FST and exact tests identified weak (global FST = 0.011) but statistically significant population structure, although little population structuring was detected using either genetic distances or an individual-based clustering method. Neither geographic distance nor the number of intervening dams were correlated with pairwise differences among populations. Tests for regional equilibrium indicate that Grand River populations were either in equilibrium between gene flow and genetic drift or that gene flow is more influential than drift. While studies on other species have identified strong dam-related effects on genetic diversity and population structure, this study suggests that barrier permeability, river fragment length and the ecological characteristics of affected species can counterbalance dam-related effects. ?? 2007 Springer Science+Business Media B.V.
A new study of China's population control during the past ten years.
Wei, J
1989-02-01
This paper summarizes the control of population in China in the past 10 years and the changes that are occurring. Recently, an increase in the number of family members has directly influenced socioeconomic status by increasing family income and improving living conditions. Rural families have no incentives to control the number of children born. The cyclic effect of the 1962-73 baby boom is also causing a recent surge in population. China has studied these problems and has taken the following measures: new family planning systems have been established; population has been controlled macroscopically and flexibility is allowed at an individual level; governmental family planning organizations have been set up and financed; family planning education has been increased; family planning services have been enforced; incentives and restrictions have been implemented. China must work as a whole to enact and enforce these policies. Families must show restraint in childbearing. The only way for this to be accomplished is by decreasing the socioeconomic incentives to have children. Finally, reforms should be in tune with changing situations.
Bjerregaard, Peter; Becker, Ulrik
2013-01-01
Questionnaires are widely used to obtain information on health-related behaviour, and they are more often than not the only method that can be used to assess the distribution of behaviour in subgroups of the population. No validation studies of reported consumption of tobacco or alcohol have been published from circumpolar indigenous communities. The purpose of the study is to compare information on the consumption of tobacco and alcohol obtained from 3 population surveys in Greenland with import statistics. Estimates of consumption of cigarettes and alcohol using several different survey instruments in cross-sectional population studies from 1993-1994, 1999-2001 and 2005-2010 were compared with import statistics from the same years. For cigarettes, survey results accounted for virtually the total import. Alcohol consumption was significantly under-reported with reporting completeness ranging from 40% to 51% for different estimates of habitual weekly consumption in the 3 study periods. Including an estimate of binge drinking increased the estimated total consumption to 78% of the import. Compared with import statistics, questionnaire-based population surveys capture the consumption of cigarettes well in Greenland. Consumption of alcohol is under-reported, but asking about binge episodes in addition to the usual intake considerably increased the reported intake in this population and made it more in agreement with import statistics. It is unknown to what extent these findings at the population level can be inferred to population subgroups.
Åström, Christofer; Åström, Daniel Oudin; Andersson, Camilla; Ebi, Kristie L; Forsberg, Bertil
2017-07-07
The health burden from heatwaves is expected to increase with rising global mean temperatures and more extreme heat events over the coming decades. Health-related effects from extreme heat are more common in elderly populations. The population of Europe is rapidly aging, which will increase the health effects of future temperatures. In this study, we estimate the magnitude of adaptation needed to lower vulnerability to heat in order to prevent an increase in heat-related deaths in the 2050s; this is the Adaptive Risk Reduction (ARR) needed. Temperature projections under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 from 18 climate models were coupled with gridded population data and exposure-response relationships from a European multi-city study on heat-related mortality. In the 2050s, the ARR for the general population is 53.5%, based on temperature projections under RCP 4.5. For the population above 65 years in Southern Europe, the ARR is projected to be 45.9% in a future with an unchanged climate and 74.7% with climate change under RCP 4.5. The ARRs were higher under RCP 8.5. Whichever emission scenario is followed or population projection assumed, Europe will need to adapt to a great degree to maintain heat-related mortality at present levels, which are themselves unacceptably high, posing an even greater challenge.
Åström, Christofer; Oudin Åström, Daniel; Andersson, Camilla; L. Ebi, Kristie; Forsberg, Bertil
2017-01-01
The health burden from heatwaves is expected to increase with rising global mean temperatures and more extreme heat events over the coming decades. Health-related effects from extreme heat are more common in elderly populations. The population of Europe is rapidly aging, which will increase the health effects of future temperatures. In this study, we estimate the magnitude of adaptation needed to lower vulnerability to heat in order to prevent an increase in heat-related deaths in the 2050s; this is the Adaptive Risk Reduction (ARR) needed. Temperature projections under Representative Concentration Pathway (RCP) 4.5 and RCP 8.5 from 18 climate models were coupled with gridded population data and exposure-response relationships from a European multi-city study on heat-related mortality. In the 2050s, the ARR for the general population is 53.5%, based on temperature projections under RCP 4.5. For the population above 65 years in Southern Europe, the ARR is projected to be 45.9% in a future with an unchanged climate and 74.7% with climate change under RCP 4.5. The ARRs were higher under RCP 8.5. Whichever emission scenario is followed or population projection assumed, Europe will need to adapt to a great degree to maintain heat-related mortality at present levels, which are themselves unacceptably high, posing an even greater challenge. PMID:28686197
Genomic Consequences of Population Decline in the Endangered Florida Scrub-Jay.
Chen, Nancy; Cosgrove, Elissa J; Bowman, Reed; Fitzpatrick, John W; Clark, Andrew G
2016-11-07
Understanding the population genetic consequences of declining population size is important for conserving the many species worldwide facing severe decline [1]. Thorough empirical studies on the impacts of population reduction at a genome-wide scale in the wild are scarce because they demand huge field and laboratory investments [1, 2]. Previous studies have demonstrated the importance of gene flow in introducing genetic variation to small populations [3], but few have documented both genetic and fitness consequences of decreased immigration through time in a natural population [4-6]. Here we assess temporal variation in gene flow, inbreeding, and fitness using longitudinal genomic, demographic, and phenotypic data from a long-studied population of federally Threatened Florida scrub-jays (Aphelocoma coerulescens). We exhaustively sampled and genotyped the study population over two decades, providing one of the most detailed longitudinal investigations of genetics in a wild animal population to date. Immigrants were less heterozygous than residents but still introduced genetic variation into our study population. Owing to regional population declines, immigration into the study population declined from 1995-2013, resulting in increased levels of inbreeding and reduced fitness via inbreeding depression, even as the population remained demographically stable. Our results show that, contrary to conventional wisdom, small peripheral populations that already have undergone a genetic bottleneck may play a vital role in preserving genetic diversity of larger and seemingly stable populations. These findings underscore the importance of investing in the persistence of small populations and maintaining population connectivity in conservation of fragmented species. Copyright © 2016 Elsevier Ltd. All rights reserved.
Morris, Gail; Hostetler, Jeffrey A; Conner, L Mike; Oli, Madan K
2011-12-01
Predation and food resources can strongly affect small mammal population dynamics directly by altering vital rates or indirectly by influencing behaviors. Fire may also strongly influence population dynamics of species inhabiting fire-adapted habitats because fire can alter food and cover availability. We used capture-mark-recapture and radio-telemetry studies to experimentally examine how supplemental feeding, mammalian predator exclusion, and prescribed fire affected survival, abundance, and reproduction of hispid cotton rats (Sigmodon hispidus) in southwestern Georgia, USA. Prescribed fire reduced survival, abundance, and rates of transitions to reproductive states. Food supplementation increased survival, transitions to reproductive states, and abundance, but was not sufficient to prevent post-fire declines in any of these parameters. Mammalian predator exclusion did not strongly affect any of the considered parameters. Our results show that fire strongly influenced cotton rat populations in our study site, primarily by reducing cover and increasing predation risk from non-mammalian predators.
Trends in acute psychiatric inpatient care in Massachusetts.
Hudson, Christopher G
2004-11-01
This report presents the preliminary results of a longitudinal study of acute psychiatric hospitalization in the Commonwealth of Massachusetts for fiscal years 1994 to 2000. The study was a secondary analysis of data obtained through the Commonwealth's mandated case-mix reporting system, covering 42 acute psychiatric facilities and 119,284 patients. Results include a 58.4 percent increase in the patient population, accompanied by declines in both length of stay and readmission rates; increases in the number of diagnoses of depression and in the number of patient deaths; and shifts to an older population increasingly supported by Medicaid and Medicare, especially managed care programs.
Overweight is an independent risk factor for cardiovascular disease in Chinese populations.
Zhou, Beifan; Wu, Yangfeng; Yang, Jun; Li, Ying; Zhang, Hongye; Zhao, Liancheng
2002-08-01
In the last decade of the 20th century, cardiovascular disease was the leading cause of death in China, accounting for one-third of the total deaths. In comparison with western populations, the mean body weight or body mass index (BMI) of the Chinese population was lower, but showed an increasing trend. Whether the variation within lower levels of BMI or waist circumference was associated with other risk factors of cardiovascular disease, and whether they contribute independently to the risk of cardiovascular disease in the Chinese population, was investigated in this study. In keeping with a uniform study design, in each of 14 study populations at different geographical locations and with different characteristics, the incidence rates of stroke, coronary heart disease (CHD) and the causes of death were monitored in approximately/= 100000 residents from 1991 to 1995 using the MONICA procedure. Risk factors were surveyed in a random cluster sample of 1000 subjects (35-59 years of age) from each population under surveillance using internationally standardized methods and a centralized system to ensure quality control. Among the risk factors, body weight, height, and waist and hip circumferences were measured. Cross-sectional stratified analyses were used to analyse the relationship of BMI (kg m(-2)) or waist circumference to other metabolic risk factors. Ten cohorts among the 14 study populations with 24734 participants were surveyed from 1982 to 1985 as a baseline for further study and were followed-up for 9 years taking the events of stroke, CHD and different causes of death as end-points. Cox regression models were used to explore the association of BMI with the relative risks of stroke, CHD and total death. The survey in 14 random samples with a total number of 19 741 subjects showed that the mean BMI (20.8-25.1) and waist circumference (67.8-86.7 cm) were much lower than those of western populations. There was, however, variation in the anthropometric measurements among populations within China. Thus, rates of overweight varied from 2.7% to 48.1% and obesity from 0% to 9.5% on the basis of the World Health Organization (WHO) classification, but these values were lower than those found in western populations. Data from the 10 cohort samples compared with baseline data in the early 1980s showed that the mean BMIs increased significantly in eight populations during the early 1990s with the differences ranging from 0.5 to 2.5 kg m(-2). Despite the lower level of BMI and the lower rate of overweight, cross-sectional analyses showed that the prevalence of hypertension, high fasting serum glucose, high serum total cholesterol and low high-density lipoprotein cholesterol (HDL-C) and their clustering were all raised with increases in BMI or waist circumference. The prospective cohort study showed that the BMI was one of the independent risk factors for stroke and CHD in Chinese populations. Hence, in a Chinese population characterized by lower levels of BMI and great variability in rates of overweight, variation of BMI was significantly related to the prevalence of other metabolic risk factors and their clustering. Overweight was one of the independent risk factors for stroke and CHD, both at population and individual levels. Given the increasing trends of BMI in the last 10 years, during the period of economic transition there is a need to encourage the population to adopt healthy dietary habits and to increase their physical activity. Health education and health promotion are important for the prevention and non-pharmacological therapy of cardiovascular disease in China.
Guo, Hua; Wang, Xiaoan; Xiao, Yaping
2005-02-01
In this paper, the fractal characters of Larix chinensis populations in Qinling Mountain were studied by contiguous grid quadrate sampling method and by boxing-counting dimension and information dimension. The results showed that the high boxing-counting dimension (1.8087) and information dimension (1.7931) reflected a higher spatial occupational degree of L. chinensis populations. Judged by the dispersal index and Morisita's pattern index, L. chinensis populations clumped at three different age stages (0-25, 25-50 and over 50 years). From Greig-Smiths' mean variance analysis, the figure of pattern scale showed that L. chinensis populations clumped in 128 m2 and 512 m2, and the different age groups clumped in different scales. The pattern intensities decreased with increasing age, and tended to reduce with increasing area when detected by Kershaw's PI index. The spatial pattern characters of L. chinensis populations may be their responses to environmental factors.
Characterization of the Hispanic or Latino Population in Health Research: A Systematic Review
Hayes, Susan L.; Chen, Mei Hsuan; González, Javier; Gany, Francesca M.
2015-01-01
The size and diversity of the Hispanic population in the United States has dramatically increased, with vast implications for health research. We conducted a systematic review of the characterization of the Hispanic population in health research and described its implications. Relevant studies were identified by searches of PubMed, Embase Scopus, and Science/Social Sciences Citation Index from 2000 to 2011. 131 articles met criteria. 56 % of the articles reported only “Hispanic” or “Latino” as the characteristic of the Hispanic research population while no other characteristics were reported. 29 % of the articles reported language, 27 % detailed country of origin and 2 % provided the breakdown of race. There is great inconsistency in reported characteristics of Hispanics in health research. The lack of detailed characterization of this population ultimately creates roadblocks in translating evidence into practice when providing care to the large and increasingly diverse Hispanic population in the US. PMID:23315046
A review of population data utilization in beef cattle research.
Jones, R; Langemeier, M
2010-04-01
Controlled experimentation has been the most common source of research data in most biological sciences. However, many research questions lend themselves to the use of population data, or combinations of population data and data resulting from controlled experimentation. Studies of important economic outcomes, such as efficiency, profits, and costs, lend themselves particularly well to this type of analysis. Analytical methods that have been most commonly applied to population data in studies related to livestock production and management include statistical regression and mathematical programming. In social sciences, such as applied economics, it has become common to utilize more than one method in the same study to provide answers to the various questions at hand. Of course, care must be taken to ensure that the methods of analysis are appropriately applied; however, a wide variety of beef industry research questions are being addressed using population data. Issues related to data sources, aggregation levels, and consistency of collection often surface when using population data. These issues are addressed by careful consideration of the questions being addressed and the costs of data collection. Previous research across a variety of cattle production and marketing issues provides a broad foundation upon which to build future research. There is tremendous opportunity for increased use of population data and increased collaboration across disciplines to address issues of importance to the cattle industry.
Jabeen, Nazish
2014-01-01
ABSTRACT Kashmiri population in the northeast of Pakistan has strong historical, cultural and linguistic affinities with the neighbouring populations of upper Punjab and Potohar region of Pakistan. However, the study of consanguineous unions, which are customarily practised in many populations of Pakistan, revealed marked differences between the Kashmiris and other populations of northern Pakistan with respect to the distribution of marriage types and inbreeding coefficient (F). The current descriptive epidemiological study carried out in Bhimber district of Mirpur division, Azad Jammu and Kashmir, Pakistan, demonstrated that consanguineous marriages were 62% of the total marriages (F=0.0348). First-cousin unions were the predominant type of marriages and constituted 50.13% of total marital unions. The estimates of inbreeding coefficient were higher in the literate subjects, and consanguinity was witnessed to be rising with increasing literacy level. Additionally, consanguinity was observed to be associated with ethnicity, family structure, language, and marriage arrangements. Based upon these data, a distinct sociobiological structure, with increased stratification and higher genomic homozygosity, is expected for this Kashmiri population. In this communication, we present detailed distribution of the types of marital unions and the incidences of consanguinity and inbreeding coefficient (F) across various sociodemographic strata of Bhimber/Mirpuri population. The results of this study would have implication not only for other endogamous populations of Pakistan but also for the sizeable Kashmiri community immigrated to Europe. PMID:25076667
Grogan, Kathleen E; Sauther, Michelle L; Cuozzo, Frank P; Drea, Christine M
2017-10-01
Across species, diversity at the major histocompatibility complex (MHC) is critical to individual disease resistance and, hence, to population health; however, MHC diversity can be reduced in small, fragmented, or isolated populations. Given the need for comparative studies of functional genetic diversity, we investigated whether MHC diversity differs between populations which are open, that is experiencing gene flow, versus populations which are closed, that is isolated from other populations. Using the endangered ring-tailed lemur ( Lemur catta ) as a model, we compared two populations under long-term study: a relatively "open," wild population ( n = 180) derived from Bezà Mahafaly Special Reserve, Madagascar (2003-2013) and a "closed," captive population ( n = 121) derived from the Duke Lemur Center (DLC, 1980-2013) and from the Indianapolis and Cincinnati Zoos (2012). For all animals, we assessed MHC-DRB diversity and, across populations, we compared the number of unique MHC-DRB alleles and their distributions. Wild individuals possessed more MHC-DRB alleles than did captive individuals, and overall, the wild population had more unique MHC-DRB alleles that were more evenly distributed than did the captive population. Despite management efforts to maintain or increase genetic diversity in the DLC population, MHC diversity remained static from 1980 to 2010. Since 2010, however, captive-breeding efforts resulted in the MHC diversity of offspring increasing to a level commensurate with that found in wild individuals. Therefore, loss of genetic diversity in lemurs, owing to small founder populations or reduced gene flow, can be mitigated by managed breeding efforts. Quantifying MHC diversity within individuals and between populations is the necessary first step to identifying potential improvements to captive management and conservation plans.
Idilbi, Nasra Muhammad; Barhana, Micha; Milman, Uzi; Carel, Rafael S
2012-11-01
The Arab population of Israel is a separate ethnic group from the Jewish population, embracing a different lifestyle and different nutritional habits and environmental exposures. These variations may lead to dissimilar expressions of certain diseases in the Arab Israeli as compared with the Jewish population. In recent years, the Arab population in Israel has experienced rapid and marked changes toward westernization in lifestyle, and significant increases in the incidence rate of both diabetes mellitus (DM) and cancer This is combined with an increase in known risk factors common to both illnesses. Review of recent publications and official health statistics provided the sources of information for this review. Studies show that in recent decades the incidence rate of DM in the Israeli Arab population has increased by 9.1 per 1000 persons annually and of cancer by 1.3 per 1000 person annually among males and by 1.2 per 1000 person among females. In contrast, these rates have decreased in the Jewish population. Lifestyle change in recent decades (westernization) in the Israeli Arab population has led to a marked increase in the incidence rate of DM and cancer in this group. The most influential risk factors are unhealthy diet, physical inactivity and tobacco smoking. By understanding these processes, effective intervention efforts can be initiated in order to reverse these trends.
DOT National Transportation Integrated Search
2015-12-01
Roads have the potential to fragment wildlife populations, leading to genetic diversity loss, : inbreeding, and increased extinction risk for small, isolated populations. In this study, we used : coyote as a model to investigate how four Northern Cal...
ERIC Educational Resources Information Center
Dewald, Robin J.
2010-01-01
The purpose of this study was to explore teaching strategies that promote a culturally sensitive nursing education and culturally sensitive nursing. The diversity of Americans has increased. Thus, the nursing student population and patient population have both become more diverse. Nursing education programs, therefore, need to know the best…
Aboagye-Sarfo, Patrick; Mai, Qun; Sanfilippo, Frank M; Preen, David B; Stewart, Louise M; Fatovich, Daniel M
2015-06-01
To determine the magnitude and characteristics of the increase in ED demand in Western Australia (WA) from 2007 to 2013. We conducted a population-based longitudinal study examining trends in ED demand, stratified by area of residence, age group, sex, Australasian Triage Scale category and discharge disposition. The outcome measures were annual number and rate of ED presentations. We calculated average annual growth, and age-specific and age-standardised rates. We assessed the statistical significance of trends, overall and within each category, using the Mann-Kendall trend test and analysis of variance ANOVA. We also calculated the proportions of growth in ED demand that were attributable to changes in population and utilisation rate. From 2007 to 2013, ED presentations increased by an average 4.6% annually from 739,742 to 945,244. The rate increased 1.4% from 354.1 to 382.6 per 1000 WA population (P = 0.02 for the trend). The main increase occurred in metropolitan WA, age 45+ years, triage category 2 and 3 and admitted cohorts. Approximately three-quarters of this increase was due to population change (growth and ageing) and one-quarter due to increase in utilisation. Our study reveals a 4.6% annual increase in ED demand in WA in 2007-2013, mostly because of an increase in people with urgent and complex care needs, and not a shift (demand transfer) from primary care. This indicates that a system-wide integrated approach is required for demand management. © 2015 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine.
Interactive effects of herbivory and competition intensity determine invasive plant performance.
Huang, Wei; Carrillo, Juli; Ding, Jianqing; Siemann, Evan
2012-10-01
Herbivory can reduce plant fitness, and its effects can be increased by competition. Though numerous studies have examined the joint effects of herbivores and competitors on plant performance, these interactive effects are seldom considered in the context of plant invasions. Here, we examined variation in plant performance within a competitive environment in response to both specialist and generalist herbivores using Chinese tallow as a model species. We combined tallow plants from native and invasive populations to form all possible pairwise combinations, and designated invasive populations as stronger neighbours and native populations as weaker neighbours. We found that when no herbivory was imposed, invasive populations always had higher total biomass than natives, regardless of their neighbours, which is consistent with our assumption of increased competitive ability. Defoliation by either generalist or specialist herbivores suppressed plant growth but the effects of specialists were generally stronger for invasive populations. Invasive populations had their lowest biomass when fed upon by specialists while simultaneously competing with stronger neighbours. The root/shoot ratios of invasive populations were lower than those of native populations under almost all conditions, and invasive plants were taller than native plants overall, especially when herbivores were present, suggesting that invasive populations may adopt an "aboveground first" strategy to cope with herbivory and competition. These results suggest that release from herbivores, especially specialists, improves an invader's performance and helps to increase its competitive ability. Therefore, increasing interspecific competition intensity by planting a stronger neighbour while simultaneously releasing a specialist herbivore may be an especially effective method of managing invasive plants.
An analysis of ED utilization by adults with intellectual disability.
Venkat, Arvind; Pastin, Rene B; Hegde, Gajanan G; Shea, John M; Cook, Jeffrey T; Culig, Carl
2011-05-01
We sought to identify factors increasing the odds of ED utilization among intellectually disabled (ID) adults and differentiate their discharge diagnoses from the general adult ED population. This was a retrospective, observational open cohort study of all ID adults residing at an intermediate care facility and their ED visits to a tertiary center (January 1, 2007-July 30, 2008). We abstracted from the intermediate care facility database subjects' demographic, ID, health and adaptive status variables, and their requirement of ED care/hospitalization. We obtained from the hospital database the primary International Classification of Diseases 9 ED/hospital discharge diagnoses for the study and general adult population. Using multivariate logistic regression, we computed odds ratios (OR) for ED utilization/hospitalization in the cohort. Using the conditional large-sample binomial test, we differentiated the study and general populations' discharge diagnoses. A total of 433 subjects met the inclusion criteria. Gastrostomy/jejunostomy increased the odds of ED utilization (OR, 4.16; confidence interval [CI], 1.64-10.58). Partial help to feed (OR, 2.59; CI, 1.14-5.88), gastrostomy/jejunostomy (OR, 3.26; CI, 1.30-8.18), and increasing number of prescribed medications (OR, 1.08; CI, 1.03-1.14) increased the odds of hospitalization. Auditory impairment (OR, 0.45; CI, 0.23-0.88) decreased the odds of hospitalization. For ED discharge diagnoses, ID adults were more likely (P < .05) than the general population to have diagnoses among digestive disorders and ill-defined symptoms/signs. For hospital discharge diagnoses, ID adults were more likely (P < .05) to have diagnoses among infectious/parasitic, nervous system, and respiratory disorders. Among ID adults, feeding status increased the odds of ED utilization, feeding status, and increasing number of prescribed medications of that hospitalization. Intellectually disabled adults' discharge diagnoses differed significantly from the general adult ED population. Copyright © 2011 Elsevier Inc. All rights reserved.
van der Meer, Sascha; Jacquemyn, Hans
2015-01-01
Due to changes in land use, the natural habitats of an increasing number of plant species have become more and more fragmented. In landscapes that consist of patches of suitable habitat, the frequency and extent of long-distance seed dispersal can be expected to be an important factor determining local genetic diversity and regional population structure of the remaining populations. In plant species that are restricted to riparian habitats, rivers can be expected to have a strong impact on the dynamics and spatial genetic structure of populations as they may enable long-distance seed dispersal and thus maintain gene flow between fragmented populations. In this study, we used polymorphic microsatellite markers to investigate the genetic diversity and the spatial genetic structure of 28 populations of Saxifraga granulata along two rivers in central Belgium. We hypothesized that rivers might be essential for gene flow among increasingly isolated populations of this species. Genetic diversity was high (HS = 0.68), which to a certain extent can be explained by the octoploid nature of S. granulata in the study area. Populations along the Dijle and Demer rivers were also highly differentiated (G” ST = 0.269 and 0.164 and D EST = 0.190 and 0.124, respectively) and showed significant isolation-by-distance, indicating moderate levels of gene flow primarily between populations that are geographically close to each other. Along the river Demer population genetic diversity was higher upstream than downstream, suggesting that seed dispersal via the water was not the primary mode of dispersal. Overall, these results indicate that despite increasing fragmentation populations along both rivers were highly genetically diverse. The high ploidy level and longevity of S. granulata have most likely buffered negative effects of fragmentation on genetic diversity and the spatial genetic structure of populations in riparian grasslands. PMID:26079603
Hunter, Mark D; Kozlov, Mikhail V; Itämies, Juhani; Pulliainen, Erkki; Bäck, Jaana; Kyrö, Ella-Maria; Niemelä, Pekka
2014-06-01
Changes in climate are influencing the distribution and abundance of the world's biota, with significant consequences for biological diversity and ecosystem processes. Recent work has raised concern that populations of moths and butterflies (Lepidoptera) may be particularly susceptible to population declines under environmental change. Moreover, effects of climate change may be especially pronounced in high latitude ecosystems. Here, we examine population dynamics in an assemblage of subarctic forest moths in Finnish Lapland to assess current trajectories of population change. Moth counts were made continuously over a period of 32 years using light traps. From 456 species recorded, 80 were sufficiently abundant for detailed analyses of their population dynamics. Climate records indicated rapid increases in temperature and winter precipitation at our study site during the sampling period. However, 90% of moth populations were stable (57%) or increasing (33%) over the same period of study. Nonetheless, current population trends do not appear to reflect positive responses to climate change. Rather, time-series models illustrated that the per capita rates of change of moth species were more frequently associated negatively than positively with climate change variables, even as their populations were increasing. For example, the per capita rates of change of 35% of microlepidoptera were associated negatively with climate change variables. Moth life-history traits were not generally strong predictors of current population change or associations with climate change variables. However, 60% of moth species that fed as larvae on resources other than living vascular plants (e.g. litter, lichen, mosses) were associated negatively with climate change variables in time-series models, suggesting that such species may be particularly vulnerable to climate change. Overall, populations of subarctic forest moths in Finland are performing better than expected, and their populations appear buffered at present from potential deleterious effects of climate change by other ecological forces. © 2014 John Wiley & Sons Ltd.
Mental health in the Dutch population and in general practice: 1987–2001
Verhaak, Peter FM; Hoeymans, Nancy; Garssen, Anna A; Westert, Gert P
2005-01-01
Background In the last 15 years, both the demand for and supply of specialised mental health care increased considerably in the Netherlands. Increased demand may reflect a change in psychological morbidity, but may also be a consequence of increased supply. Specialised health care in the Netherlands is accessible only through referral by a GP, and so it is important to consider the role of primary care in the diagnosis of mental health problems. Aim The aim of this study is to achieve a better understanding of the development of mental health status in the Dutch population and the consequent help-seeking behaviour in primary care. Method Using two comparable morbidity studies carried out in the Dutch population and in primary care, we compared data from 1987 and 2001 to assess the following: possible differences in mental health between 1987 and 2001; possible differences in prevalence of mental disorder as diagnosed by GPs in 1987 and 2001; possible differences in the sociodemographic determinants of mental health and mental disorder in primary care between 1987 and 2001. Results Our results show an increase in mental and social problems in the population between 1987 and 2001. However, GPs diagnosed fewer patients as having a mental disorder in 2001 than they did in 1987. The risk of mental disorders or social problems in several sociodemographic groups remained largely the same, as did the chance of receiving a psychological or social diagnosis. Conclusion We conclude that, while mental disorder in the population is increasing, the role of primary care has changed. Although GPs diagnose a lower percentage of mental problems as such, they refer an increasingly larger proportion of these to secondary care. PMID:16212852
Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja
2014-01-01
Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes. PMID:24552840
Egea-Serrano, Andrés; Hangartner, Sandra; Laurila, Anssi; Räsänen, Katja
2014-04-07
Environmental change can simultaneously cause abiotic stress and alter biological communities, yet adaptation of natural populations to co-changing environmental factors is poorly understood. We studied adaptation to acid and predator stress in six moor frog (Rana arvalis) populations along an acidification gradient, where abundance of invertebrate predators increases with increasing acidity of R. arvalis breeding ponds. First, we quantified divergence among the populations in anti-predator traits (behaviour and morphology) at different rearing conditions in the laboratory (factorial combinations of acid or neutral pH and the presence or the absence of a caged predator). Second, we evaluated relative fitness (survival) of the populations by exposing tadpoles from the different rearing conditions to predation by free-ranging dragonfly larvae. We found that morphological defences (relative tail depth) as well as survival of tadpoles under predation increased with increasing pond acidity (under most experimental conditions). Tail depth and larval size mediated survival differences among populations, but the contribution of trait divergence to survival was strongly dependent on prior rearing conditions. Our results indicate that R. arvalis populations are adapted to the elevated predator pressure in acidified ponds and emphasize the importance of multifarious selection via both direct (here: pH) and indirect (here: predators) environmental changes.
Suicidal ideation and attempts in patients with stroke: a population-based study.
Chung, Jae Ho; Kim, Jung Bin; Kim, Ji Hyun
2016-10-01
Stroke is known to be associated with an increase in the risk for suicide. However, there are very few population-based studies investigating the risk of suicidal ideation and attempts in patients with stroke. The purpose of this study was to compare the risk of suicidal ideation and attempts between patients with stroke and population without stroke using nationwide survey data. Individual-level data were obtained from 228,735 participants (4560 with stroke and 224,175 without stroke) of the 2013 Korean Community Health Survey. Demographic characteristics, socioeconomic status, physical health status, and mental health status were compared between patients with stroke and population without stroke. Multivariable logistic regression was performed to investigate the independent effects of the stroke on suicidal ideation and attempts. Stroke patients had more depressive mood (12.6 %) than population without stroke (5.7 %, p < 0.001). Stroke patients experienced more suicidal ideation (24.4 %) and attempts (1.3 %) than population without stroke (9.8 and 0.4 %, respectively; both p < 0.001). Stroke was found to increase the risk for suicidal ideation (OR 1.65, 95 % CI 1.52-1.79) and suicidal attempts (OR 1.64, 95 % CI 1.21-2.22), adjusting for demographics, socioeconomic factors, and physical health and mental health factors. We found that stroke increased the risk for suicidal ideation and attempts, independent of other factors that are known to be associated with suicidality, suggesting that stroke per se may be an independent risk factor for suicidality.
Virani, Shama; Rentschler, Katie M.; Nishijo, Muneko; Ruangyuttikarn, Werawan; Swaddiwudhipong, Witaya; Basu, Niladri; Rozek, Laura S.
2016-01-01
The adverse health effects of cadmium (Cd) are well known in human populations; however, much of what is known about biological mechanisms of Cd comes from in vitro and animal studies. The adverse health outcomes due to high levels of Cd exposure in the population of Mae Sot, Thailand have been extensively characterized. Here, for the first time, this population is being studied in an epigenetic context. The objective of this study was to characterize the association between DNA methylation markers and Cd exposure, taking into account sex and smoking differences, in an adult population at an increased risk of experiencing adverse health outcomes from high body burden of Cd. One hundred and sixty-nine residents from known exposure areas of Mae Sot, Thailand and one hundred residents from non-exposed areas nearby were surveyed in 2012. Urine and blood samples were collected for measurement of urinary Cd (UCd) and DNA methylation of Cd-related markers (DNMT3B, MGMT, LINE-1, MT2A). UCd levels were 7 times higher in the exposed compared to the unexposed populations (exposed median: 7.4 μg/L, unexposed median: 1.0 μg/L, p <0.001). MGMT hypomethylation was associated with increasing levels of UCd in the total population. Sex-specific associations included MT2A and DNMT3B hypomethylation in women and LINE-1 hypermethylation in men with increasing UCd. Upon subanalysis, these associations separated by smoking status. In summary, environmental Cd exposure is associated with gene-specific DNA methylation in a sex and smoking dependent manner. PMID:26688266
Grøvle, Lars; Haugen, Anne J; Ihlebaek, Camilla M; Keller, Anne; Natvig, Bård; Brox, Jens I; Grotle, Margreth
2011-06-01
Chronic nonspecific low back pain is accompanied by high rates of comorbid mental and physical conditions. The aims of this study were to investigate if patients with specific back pain, that is, sciatica caused by lumbar herniation, report higher rates of subjective health complaints (SHCs) than the general population and if there is an association between change in sciatica symptoms and change in SHCs over a 12-month period. A multicenter cohort study of 466 sciatica patients was conducted with follow-up at 3 months and 1 year. Comorbid SHCs were measured by 27 items of the SHC inventory. Odds ratios (ORs) for each SHC were calculated with comparison to a general population sample (n=928) by logistic regression. The SHC number was calculated by summing all complaints present. At baseline, the ORs for reporting SHCs for the sciatica patients were significantly elevated in 15 of the 27 items with a mean (S.D.) SHC number of 7.5 (4.4), compared to 5.2 (4.4) in the general population (P<.01). Among those who during the 1-year follow-up period fully recovered from their sciatica, the SHC number was reduced to normal levels. Among those with persisting or worsening sciatica, the number increased to a level almost double that of the general population. Compared to the general population, the prevalence of subjective health complaints in sciatica is increased. During follow-up, the number of health complaints increased in patients with persisting or worsening sciatica. Copyright © 2010 Elsevier Inc. All rights reserved.
Premature mortality due to social and material deprivation in Nova Scotia, Canada.
Saint-Jacques, Nathalie; Dewar, Ron; Cui, Yunsong; Parker, Louise; Dummer, Trevor Jb
2014-10-25
Inequalities in health attributable to inequalities in society have long been recognized. Typically, those most privileged experience better health, regardless of universal access to health care. Associations between social and material deprivation and mortality from all causes of death--a measure of population health, have been described for some regions of Canada. This study further examines the link between deprivation and health, focusing on major causes of mortality for both rural and urban populations. In addition, it quantifies the burden of premature mortality attributable to social and material deprivation in a Canadian setting where health care is accessible to all. The study included 35,266 premature deaths (1995-2005), grouped into five causes and aggregated over census dissemination areas. Two indices of deprivation (social and material) were derived from six socioeconomic census variables. Premature mortality was modeled as a function of these deprivation indices using Poisson regression. Premature mortality increased significantly with increasing levels of social and material deprivation. The impact of material deprivation on premature mortality was similar in urban and rural populations, whereas the impact of social deprivation was generally greater in rural populations. There were a doubling in premature mortality for those experiencing a combination of the most extreme levels of material and social deprivation. Socioeconomic deprivation is an important determinant of health equity and affects every segment of the population. Deprivation accounted for 40% of premature deaths. The 4.3% of the study population living in extreme levels of socioeconomic deprivation experienced a twofold increased risk of dying prematurely. Nationally, this inequitable risk could translate into a significant public health burden.
Immediate or lagged responses of a red squirrel population to pulsed resources.
Selonen, Vesa; Varjonen, Rauno; Korpimäki, Erkki
2015-02-01
According to producer-consumer models, consumers should follow pulsed resources with a time lag. This view has been challenged by studies demonstrating that individuals may anticipate future resource pulses by increasing reproduction just before the pulse. We studied population fluctuations and reproduction in European red squirrels, Sciurus vulgaris, in relation to seed masting of the main food resource (the Norway spruce) in boreal coniferous forests between 1979 and 2013. Red squirrels are pre-dispersal seed predators, and previous studies have shown that they can anticipate the coming seed mast. We did not find any indication that anticipation of masting (year t ) increased red squirrel reproduction in the preceding spring to early summer. Instead, the reproductive output of the squirrels was highest in the spring following the mast, indicating that the population had to be at its largest size in the autumn after the mast (year(t+1)), when lots of subadults were around. However, we surmised, based on snow tracks and squirrel nest data, that the population crashed during the following winter (year(t+1)). These data reflected the adult population during winter, which peaked at the same time as the resource pulse. We can therefore conclude that the time lag between the resource pulse and the attainment of the peak number of squirrels was less than one year, and that the resource crash affected more juveniles and subadults than adults. The population increase overlapped with the occurrence of masting, but there was also a lagged response, supporting the classical view of producer-consumer models.
Nichols, Gordon L; Richardson, Judith F; Sheppard, Samuel K; Lane, Chris; Sarran, Christophe
2012-01-01
To review Campylobacter cases in England and Wales over 2 decades and examine the main factors/mechanisms driving the changing epidemiology. A descriptive study of Campylobacter patients between 1989 and 2011. Cases over 3 years were linked anonymously to postcode, population density, deprivation indices and census data. Cases over 5 years were anonymously linked to local weather exposure estimates. Patients were from general practice, hospital and environmental health investigations through primary diagnostic laboratories across England and Wales. There were 1 109 406 cases. Description of changes in Campylobacter epidemiology over 23 years and how the main drivers may influence these. There was an increase in Campylobacter cases over the past 23 years, with the largest increase in people over 50 years. Changes in the underlying population have contributed to this, including the impacts of population increases after World War I, World War II and the 'baby boom' of the 1960s. A recent increase in risk or ascertainment within this population has caused an increase in cases in all age groups from 2004 to 2011. The seasonal increase in cases between weeks 18 (Early May) and 22 (Early June) was consistent across ages, years and regions and was most marked in children and in more rural regions. Campylobacter prevalence by week in each region correlated with temperature 2 weeks before. There were higher prevalences in areas with a low population density, low deprivation and lower percentage of people of ethnic origin. Data from sero-phage and multilocus sequence typing show a few common types and many uncommon types. The drivers/mechanisms influencing seasonality, age distribution, population density, socioeconomic and long-term differences are diverse and their relative contributions remain to be established. Surveillance and typing provide insights into Campylobacter epidemiology and sources of infection, providing a sound basis for targeted interventions.
Potvin, Dominique A; Clegg, Sonya M
2015-02-01
In birds, song divergence often precedes and facilitates divergence of other traits. We assessed the relative roles of cultural drift, innovation, and acoustic adaptation in divergence of island bird dialects, using silvereyes (Zosterops lateralis). In recently colonized populations, syllable diversity was not significantly lower than source populations, shared syllables between populations decreased with increasing number of founder events, and dialect variation displayed contributions from both habitat features and drift. The breadth of multivariate space occupied by recently colonized Z. l. lateralis populations was comparable to evolutionarily old forms that have diverged over thousands to hundreds of thousands of years. In evolutionarily old subspecies, syllable diversity was comparable to the mainland and the amount of variation in syllable composition explained by habitat features increased by two- to threefold compared to recently colonized populations. Together these results suggest that cultural drift influences syllable repertoires in recently colonized populations, but innovation likely counters syllable loss from colonization. In evolutionarily older populations, the influence of acoustic adaptation increases, possibly favoring a high diversity of syllables. These results suggest that the relative importance of cultural drift and acoustic adaptation changes with time since colonization in island bird populations, highlighting the value of considering multiple mechanisms and timescale of divergence when investigating island song divergence. © 2014 The Author(s). Evolution © 2014 The Society for the Study of Evolution.
Yaka, Reyhan; Birand, Ayşegül; Yılmaz, Yasemin; Caner, Ceren; Açan, Sinan Can; Gündüzalp, Sidar; Parvizi, Poorya; Erim Özdoğan, Aslı; Togan, İnci; Somel, Mehmet
2018-05-01
North Mesopotamia has witnessed dramatic social change during the Holocene, but the impact of these events on its demographic history is poorly understood. Here, we study this question by analysing genetic data from the recently excavated Late Iron Age settlement of Çemialo Sırtı in Batman, southeast Turkey. Archaeological and radiocarbon evidence indicate that the site was inhabited during the second and first millennia BCE. Çemialo Sırtı reveals nomadic items of the Early Iron Age, as well as items associated with the Late Achaemenid and subsequent Hellenistic Periods. We compare Çemialo Sırtı mitochondrial DNA profiles with earlier and later populations from west Eurasia to describe genetic continuity patterns in the region. A total of 16 Çemialo Sırtı individuals' remains were studied. PCR and Sanger sequencing were used to obtain mitochondrial DNA HVRI-HVRII sequences. We studied haplotype diversity and pairwise genetic distances using F ST , comparing the Çemialo Sırtı population with ancient and modern-day populations from west Eurasia. Coalescent simulations were carried out to test continuity for specific population comparisons. Mitochondrial DNA (mtDNA) haplotypes from 12 Çemialo Sırtı individuals reveal high haplotype diversity in this population, conspicuously higher than early Holocene west Eurasian populations, which supports the notion of increasing population admixture in west Eurasia through the Holocene. In its mtDNA composition, Çemialo Sırtı shows highest affinity to Neolithic north Syria and Neolithic Anatolia among ancient populations studied, and to modern-day southwest Asian populations. Based on population genetic simulations we cannot reject continuity between Neolithic and Iron Age, or between Iron Age and present-day populations of the region. Despite the region's complex sociopolitical history and indication for increased genetic diversity over time, we find no evidence for sharp shifts in north Mesopotamian maternal genetic composition within the last 10,000 years. © 2018 Wiley Periodicals, Inc.
Kevin Ford; Joshua H. Ness; Judith L. Bronstein; William F. Morris
2015-01-01
The impact of mutualists on a partnerâs demography depends on how they affect the partnerâs multiple vital rates and how those vital rates, in turn, affect population growth. However, mutualism studies rarely measure effects on multiple vital rates or integrate them to assess the ultimate impact on population growth. We used vital rate data, population models and...
Tack, Ayco J. M.; Mononen, Tommi; Hanski, Ilkka
2015-01-01
Climate change is known to shift species' geographical ranges, phenologies and abundances, but less is known about other population dynamic consequences. Here, we analyse spatio-temporal dynamics of the Glanville fritillary butterfly (Melitaea cinxia) in a network of 4000 dry meadows during 21 years. The results demonstrate two strong, related patterns: the amplitude of year-to-year fluctuations in the size of the metapopulation as a whole has increased, though there is no long-term trend in average abundance; and there is a highly significant increase in the level of spatial synchrony in population dynamics. The increased synchrony cannot be explained by increasing within-year spatial correlation in precipitation, the key environmental driver of population change, or in per capita growth rate. On the other hand, the frequency of drought during a critical life-history stage (early larval instars) has increased over the years, which is sufficient to explain the increasing amplitude and the expanding spatial synchrony in metapopulation dynamics. Increased spatial synchrony has the general effect of reducing long-term metapopulation viability even if there is no change in average metapopulation size. This study demonstrates how temporal changes in weather conditions can lead to striking changes in spatio-temporal population dynamics. PMID:25854888
Tang, Grace S Y; Sadanandan, Keren R; Rheindt, Frank E
2016-01-01
With increasing urbanization, urban-fragmented landscapes are becoming more and more prevalent worldwide. Such fragmentation may lead to small, isolated populations that face great threats from genetic factors that affect even avian species with high dispersal propensities. Yet few studies have investigated the population genetics of species living within urban-fragmented landscapes in the Old World tropics, in spite of the high levels of deforestation and fragmentation within this region. We investigated the evolutionary history and population genetics of the olive-winged bulbul (Pycnonotus plumosus) in Singapore, a highly urbanized island which retains <5% of its original forest cover in fragments. Combining our own collected and sequenced samples with those from the literature, we conducted phylogenetic and population genetic analyses. We revealed high genetic diversity, evidence for population expansion, and potential presence of pronounced gene flow across the population in Singapore. This suggests increased chances of long-term persistence for the olive-winged bulbul and the ecosystem services it provides within this landscape.
Meyer, J D F; Snook, M E; Houchins, K E; Rector, B G; Widstrom, N W; McMullen, M D
2007-06-01
Maysin is a naturally occurring C-glycosyl flavone found in maize (Zea mays L.) silk tissue that confers resistance to corn earworm (Helicoverpa zea, Boddie). Recently, two new maize populations were derived for high silk maysin. The two populations were named the exotic populations of maize (EPM) and the southern inbreds of maize (SIM). Quantitative trait locus (QTL) analysis was employed to determine which loci were responsible for elevated maysin levels in inbred lines derived from the EPM and SIM populations. The candidate genes consistent with QTL position included the p (pericarp color), c2 (colorless2), whp1 (white pollen1) and in1 (intensifier1) loci. The role of these loci in controlling high maysin levels in silks was tested by expression analysis and use of the loci as genetic markers onto the QTL populations. These studies support p, c2 and whp1, but not in1, as loci controlling maysin. Through this study, we determined that the p locus regulates whp1 transcription and that increased maysin in these inbred lines was primarily due to alleles at both structural and regulatory loci promoting increased flux through the flavone pathway by increasing chalcone synthase activity.
Hardman, Samuel I; Dalesman, Sarah
2018-03-22
Animals in urban habitats face many novel selection pressures such as increased human population densities and human disturbance. This is predicted to favour bolder and more aggressive individuals together with greater flexibility in behaviour. Previous work has focussed primarily on studying these traits in captive birds and has shown increased aggression and reduced consistency between traits (behavioural syndromes) in birds from urban populations. However, personality (consistency within a behavioural trait) has not been well studied in the wild. Here we tested whether urban free-living male great tits show greater territorial aggression than rural counterparts. We also tested predictions that both behavioural syndromes and personality would show lower consistency in urban populations. We found that urban populations were more aggressive than rural populations and urban birds appeared to show lower levels of individual behavioural repeatability (personality) as predicted. However, we found no effect of urbanisation on behavioural syndromes (correlations between multiple behavioural traits). Our results indicate that urban environments may favour individuals which exhibit increased territorial aggression and greater within-trait flexibility which may be essential to success in holding urban territories. Determining how urban environments impact key fitness traits will be important in predicting how animals cope with ongoing urbanisation.
Coronary heart disease in Indian Asians.
Tan, Sian-Tsung; Scott, William; Panoulas, Vasileios; Sehmi, Joban; Zhang, Weihua; Scott, James; Elliott, Paul; Chambers, John; Kooner, Jaspal S
2014-01-01
The Indian Asian population accounts for a fifth of all global deaths from coronary heart disease (CHD). CHD deaths on the Indian subcontinent have doubled since 1990, and are predicted to rise a further 50% by 2030. Reasons underlying the increased CHD mortality among Indian Asians remain unknown. Although conventional cardiovascular risk factors contribute to CHD in Indian Asians as in other populations, these do not account for their increased risk. Type-2 diabetes, insulin resistance and related metabolic disturbances are more prevalent amongst Indian Asians than Europeans, and have been proposed as major determinants of higher CHD risk among Indian Asians. However, this view is not supported by prospective data. Genome-wide association studies have not identified differences in allele frequencies or effect sizes in known loci to explain the increased CHD risk in Indian Asians. Limited knowledge of mechanisms underlying higher CHD risk amongst Indian Asians presents a major obstacle to reducing the burden of CHD in this population. Systems biology approaches such as genomics, epigenomics, metabolomics and transcriptomics, provide a non-biased approach for discovery of novel biomarkers and disease pathways underlying CHD. Incorporation of these 'omic' approaches in prospective Indian Asian cohorts such as the London Life Sciences Population Study (LOLIPOP) provide an exciting opportunity for the identification of new risk factors underlying CHD in this high risk population.
North American osprey populations and contaminants: Historic and contemporary perspectives
Henny, Charles J.; Grove, Robert A.; Kaiser, James L.; Johnson, Branden L.
2010-01-01
Osprey (Pandion haliaetus) populations were adversely affected by DDT and perhaps other contaminants in the United States and elsewhere. Reduced productivity, eggshell thinning, and high DDE concentrations in eggs were the signs associated with declining osprey populations in the 1950s, 1960s, and 1970s. The species was one of the first studied on a large scale to bring contaminant issues into focus. Although few quantitative population data were available prior to the 1960s, many osprey populations in North America were studied during the 1960s and 1970s with much learned about basic life history and biology. This article reviews the historical and current effects of contaminants on regional osprey populations. Breeding populations in many regions of North America showed post-DDT-era (1972) population increases of varying magnitudes, with many populations now appearing to stabilize at much higher numbers than initially reported in the 1970s and 1980s. However, the magnitude of regional population increases in the United States between 1981 (first Nationwide Survey, ∼8,000 pairs), when some recovery had already occurred, 1994 (second survey, ∼14,200), and 2001 (third survey, ∼16,000–19,000), or any other years, is likely not a simple response to the release from earlier contaminant effects, but a response to multi-factorial effects. This indirect “contaminant effects” measurement comparing changes (i.e., recovery) in post-DDT-era population numbers over time is probably confounded by changing human attitudes toward birds of prey (shooting, destroying nests, etc.), changing habitats, changing fish populations, and perhaps competition from other species. The species' adaptation to newly created reservoirs and its increasing use of artificial nesting structures (power poles, nesting platforms, cell towers, channel markers, offshore duck blinds, etc.) are two important factors. The timing of the initial use of artificial nesting structures, which replaced declining numbers of suitable trees at many locations, varied regionally (much later in the western United States and Mexico). Because of the increasing use of artificial nesting structures, there may be more ospreys nesting in North America now than ever before. Now, with the impact of most legacy organic contaminants (DDT, other organochlorine [OC] pesticides, polychlorinated biphenyls [PCB], polychlorinated dibenzo-p-dioxins [PCDD], polychlorinated dibenzofurans (PCDF]) greatly reduced or eliminated, and some osprey populations showing evidence of stabilizing, the species was proposed as a Worldwide Sentinel Species for evaluating emerging contaminants. Several emerging contaminants are already being studied, such as polybrominated diphenyl ethers (PBDE) and perfluorinated acids and sulfonate compounds (PFC). The many advantages for continued contaminant investigations using the osprey include a good understanding of its biology and ecology, its known distribution and abundance, and its ability to habituate to humans and their activities, which permits nesting in some of the potentially most contaminated environments. It is a top predator in most ecosystems, and its nests are relatively easy to locate and study with little researcher impact on reproductive success.
Quantifying the life-history response to increased male exposure in female Drosophila melanogaster.
Edward, Dominic A; Fricke, Claudia; Gerrard, Dave T; Chapman, Tracey
2011-02-01
Precise estimates of costs and benefits, the fitness economics, of mating are of key importance in understanding how selection shapes the coevolution of male and female mating traits. However, fitness is difficult to define and quantify. Here, we used a novel application of an established analytical technique to calculate individual- and population-based estimates of fitness-including those sensitive to the timing of reproduction-to measure the effects on females of increased exposure to males. Drosophila melanogaster females were exposed to high and low frequencies of contact with males, and life-history traits for each individual female were recorded. We then compared different fitness estimates to determine which of them best described the changes in life histories. We predicted that rate-sensitive estimates would be more accurate, as mating influences the rate of offspring production in this species. The results supported this prediction. Increased exposure to males led to significantly decreased fitness within declining but not stable or increasing populations. There was a net benefit of increased male exposure in expanding populations, despite a significant decrease in lifespan. The study shows how a more accurate description of fitness, and new insights can be achieved by considering individual life-history strategies within the context of population growth. © 2010 The Author(s). Evolution© 2010 The Society for the Study of Evolution.
Long, Qian; Xu, Ling; Bekedam, Henk; Tang, Shenglan
2013-06-13
China's health system reform launched in early 2000s has achieved better coverage of health insurance and significantly increased the use of healthcare for vast majority of Chinese population. This study was to examine changes in the structure of total health expenditures in China in 2000-2011, and to investigate the financial burden of healthcare placed on its population, particularly between urban and rural areas and across different socio-economic development regions. Health expenditures data came from the China National Health Accounts study in 1990-2011, and other data used to calculate the financial burden of healthcare were from China Statistical Yearbook and China Population Statistical Yearbook. Total health expenditures were divided into government and social expenditure, and out-of-pocket payment. The financial burden of healthcare was estimated as out-of-pocket payment per capita as a percentage of annual household living consumption expenditure per capita. Between 2000 and 2011, total health expenditures in China increased from Chinese yuan 319 to 1888 (United States dollars 51 to 305), with average annual increase of 17.4%. Government and social health expenditure increased rapidly being 22.9% and 18.8% of average annual growth rate, respectively. The share of out-of-pocket payment in total health expenditure for the urban population declined from 53% in 2005 to 36% in 2011, but had only a slight decrease for the rural population from 53% to 50%. Out-of-pocket payment, as a percentage of annual household living consumption, has continued to rise, particularly in the rural population from the less developed region (6.1% in 2000 to 8.8% in 2011). The rapid increase of public funding to subsidize health insurance in China, as part of the reform strategy, did not mitigate the out-of-pocket payment for healthcare over the past decade. Financial burden of healthcare on the rural population increased. Affordability among the rural households with sick members, particularly in the less developed region, is getting worse. It needs effective measures on cost control including healthcare provider payment reform and well developed health insurance schemes to offer better financial protection for the vulnerable Chinese seeking essential healthcare.
Jakobsson, Anna; Padrón, Benigno
2014-01-01
Invasive plants may compete with native species for abiotic factors as light, space and nutrients, and have also been shown to affect native pollination interactions. Studies have mainly focused on how invasive plants affect pollinator behaviour, i.e. attraction of pollinators to or away from native flowers. However, when an invasive plant provides resources utilized by native pollinators this could increase pollinator population sizes and thereby pollination success in natives. Effects mediated through changes in pollinator population sizes have been largely ignored in previous studies, and the dominance of negative interactions suggested by meta-analyses may therefore be biased. We investigated the impact of the invasive Lupinus polyphyllus on pollination in the native Lotus corniculatus using a study design comparing invaded and uninvaded sites before and after the flowering period of the invasive. We monitored wild bee abundance in transects, and visit rate and seed production of potted Lotus plants. Bumblebee abundance increased 3.9 times in invaded sites during the study period, whereas it was unaltered in uninvaded sites. Total visit rate per Lotus plant increased 2.1 times in invaded sites and decreased 4.4 times in uninvaded sites. No corresponding change in seed production of Lotus was found. The increase in visit rate to Lotus was driven by an increase in solitary bee visitation, whereas mainly bumblebees were observed to visit the invasive Lupinus. The mechanism by which the invasive increases pollinator visit rates to Lotus could be increased availability of other flower resources for solitary bees when bumblebees forage on Lupinus.
How much gene flow is needed to avoid inbreeding depression in wild tiger populations?
Kenney, John; Allendorf, Fred W.; McDougal, Charles; Smith, James L. D.
2014-01-01
The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations. PMID:24990671
How much gene flow is needed to avoid inbreeding depression in wild tiger populations?
Kenney, John; Allendorf, Fred W; McDougal, Charles; Smith, James L D
2014-08-22
The number and size of tiger populations continue to decline owing to habitat loss, habitat fragmentation and poaching of tigers and their prey. As a result, tiger populations have become small and highly structured. Current populations have been isolated since the early 1970s or for approximately seven generations. The objective of this study is to explore how inbreeding may be affecting the persistence of remaining tiger populations and how dispersal, either natural or artificial, may reduce the potentially detrimental effect of inbreeding depression. We developed a tiger simulation model and used published levels of genetic load in mammals to simulate inbreeding depression. Following a 50 year period of population isolation, we introduced one to four dispersing male tigers per generation to explore how gene flow from nearby populations may reduce the negative impact of inbreeding depression. For the smallest populations, even four dispersing male tigers per generation did not increase population viability, and the likelihood of extinction is more than 90% within 30 years. Unless habitat connectivity is restored or animals are artificially introduced in the next 70 years, medium size wild populations are also likely to go extinct, with only four to five of the largest wild tiger populations likely to remain extant in this same period without intervention. To reduce the risk of local extinction, habitat connectivity must be pursued concurrently with efforts to increase population size (e.g. enhance habitat quality, increase habitat availability). It is critical that infrastructure development, dam construction and other similar projects are planned appropriately so that they do not erode the extent or quality of habitat for these populations so that they can truly serve as future source populations. © 2014 The Author(s) Published by the Royal Society. All rights reserved.
Desowitz, R. S.; Saave, J. J.
1965-01-01
The formolized tanned sheep erythrocyte haemagglutination test has been applied to an immuno-malariometric study in Australian New Guinea to determine whether the haemagglutination titre reflects a subject's immune state and to measure the effect of malaria control operations on a population's immunity. Two population groups were studied—one (unprotected) living in holoendemic malaria conditions, the other (protected) living in an area subject to malaria control measures for four years. An increase in both serological positivity rates and geometric mean titres among the unprotected group with increasing age suggests that the test does serve to assess the state of immunity; the corresponding rates were much lower in the protected population, particularly among the children. The authors foresee the possible use of the haemagglutination test as a supplement to other procedures in assessing the progress of a malaria campaign. They, note, however, that more immuno-malariometric studies on populations subject to different degrees of malaria endemicity will need to be carried out before the relationship between the immune state and serological results can be clearly established. PMID:14310901
Corporate social responsibility initiatives addressing social exclusion in Bangladesh.
Werner, Wendy J
2009-08-01
The private sector is often seen as a driver of exclusionary processes rather than a partner in improving the health and welfare of socially-excluded populations. However, private-sector initiatives and partnerships- collectively labelled corporate social responsibility (CSR) initiatives-may be able to positively impact social status, earning potential, and access to services and resources for socially-excluded populations. This paper presents case studies of CSR projects in Bangladesh that are designed to reduce social exclusion among marginalized populations and explores whether CSR initiatives can increase economic and social capabilities to reduce exclusion. The examples provide snapshots of projects that (a) increase job-skills and employment opportunities for women, disabled women, and rehabilitated drug-users and (b) provide healthcare services to female workers and their communities. The CSR case studies cover a limited number of people but characteristics and practices replicable and scaleable across different industries, countries, and populations are identified. Common success factors from the case studies form the basis for recommendations to design and implement more CSR initiatives targeting socially-excluded groups. The analysis found that CSR has potential for positive and lasting impact on developing countries, especifically on socially-excluded populations. However, there is a need for additional monitoring and critical evaluation.
Corcuera, Leyre; Gil-Pelegrín, Eustaquio; Notivol, Eduardo
2012-12-01
We studied the intraspecific variability of maritime pine in a set of morphological and physiological traits: soil-to-leaf hydraulic conductance, intrinsic water-use efficiency (WUE, estimated by carbon isotope composition, δ(13)C), root morphology, xylem anatomy, growth and carbon allocation patterns. The data were collected from Pinus pinaster Aiton seedlings (25 half-sib families from five populations) grown in a greenhouse and subjected to water and water-stress treatments. The aims were to relate this variability to differences in water availability at the geographic location of the populations, and to study the potential trade-offs among traits. The drought-stressed seedlings demonstrated a decrease in hydraulic conductance and root surface area and increased WUE and root tip number. The relationships among the growth, morphological, anatomical and physiological traits changed with the scale of study: within the species, among/within populations. The populations showed a highly significant relationship between the percentage reduction in whole-plant hydraulic conductance and WUE. The differences among the populations in root morphology, whole-plant conductance, carbon allocation, plant growth and WUE were significant and consistent with dryness of the site of seed origin. The xeric populations exhibited lower growth and a conservative water use, as opposed to the fast-growing, less water-use-efficient populations from mesic habitats. The xeric and mesic populations, Tamrabta and San Cipriano, respectively, showed the most contrasting traits and were clustered in opposite directions along the main axis in the canonical discriminant analysis under both the control and drought treatments. The results suggest the possibility of selecting the Arenas population, which presents a combination of traits that confer increased growth and drought resistance.
2011-01-01
Background Hypertension may increase tortuosity or twistedness of arteries. We applied a centerline extraction algorithm and tortuosity metric to magnetic resonance angiography (MRA) brain images to quantitatively measure the tortuosity of arterial vessel centerlines. The most commonly used arterial tortuosity measure is the distance factor metric (DFM). This study tested a DFM based measurement’s ability to detect increases in arterial tortuosity of hypertensives using existing images. Existing images presented challenges such as different resolutions which may affect the tortuosity measurement, different depths of the area imaged, and different artifacts of imaging that require filtering. Methods The stability and accuracy of alternative centerline algorithms was validated in numerically generated models and test brain MRA data. Existing images were gathered from previous studies and clinical medical systems by manually reading electronic medical records to identify hypertensives and negatives. Images of different resolutions were interpolated to similar resolutions. Arterial tortuosity in MRA images was measured from a DFM curve and tested on numerically generated models as well as MRA images from two hypertensive and three negative control populations. Comparisons were made between different resolutions, different filters, hypertensives versus negatives, and different negative controls. Results In tests using numerical models of a simple helix, the measured tortuosity increased as expected with more tightly coiled helices. Interpolation reduced resolution-dependent differences in measured tortuosity. The Korean hypertensive population had significantly higher arterial tortuosity than its corresponding negative control population across multiple arteries. In addition one negative control population of different ethnicity had significantly less arterial tortuosity than the other two. Conclusions Tortuosity can be compared between images of different resolutions by interpolating from lower to higher resolutions. Use of a universal negative control was not possible in this study. The method described here detected elevated arterial tortuosity in a hypertensive population compared to the negative control population and can be used to study this relation in other populations. PMID:22166145
Diedrich, Karl T; Roberts, John A; Schmidt, Richard H; Kang, Chang-Ki; Cho, Zang-Hee; Parker, Dennis L
2011-10-18
Hypertension may increase tortuosity or twistedness of arteries. We applied a centerline extraction algorithm and tortuosity metric to magnetic resonance angiography (MRA) brain images to quantitatively measure the tortuosity of arterial vessel centerlines. The most commonly used arterial tortuosity measure is the distance factor metric (DFM). This study tested a DFM based measurement's ability to detect increases in arterial tortuosity of hypertensives using existing images. Existing images presented challenges such as different resolutions which may affect the tortuosity measurement, different depths of the area imaged, and different artifacts of imaging that require filtering. The stability and accuracy of alternative centerline algorithms was validated in numerically generated models and test brain MRA data. Existing images were gathered from previous studies and clinical medical systems by manually reading electronic medical records to identify hypertensives and negatives. Images of different resolutions were interpolated to similar resolutions. Arterial tortuosity in MRA images was measured from a DFM curve and tested on numerically generated models as well as MRA images from two hypertensive and three negative control populations. Comparisons were made between different resolutions, different filters, hypertensives versus negatives, and different negative controls. In tests using numerical models of a simple helix, the measured tortuosity increased as expected with more tightly coiled helices. Interpolation reduced resolution-dependent differences in measured tortuosity. The Korean hypertensive population had significantly higher arterial tortuosity than its corresponding negative control population across multiple arteries. In addition one negative control population of different ethnicity had significantly less arterial tortuosity than the other two. Tortuosity can be compared between images of different resolutions by interpolating from lower to higher resolutions. Use of a universal negative control was not possible in this study. The method described here detected elevated arterial tortuosity in a hypertensive population compared to the negative control population and can be used to study this relation in other populations.
Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Carter, Sue; He, Ka
2016-01-01
We aimed to evaluate the association of cadmium exposure with the risk of prostate cancer in both the general and occupational populations. Online database searches were performed for studies of prostate cancer risk and cadmium exposure. Twelve cohort studies (5 in the general, 7 in occupational populations) and 9 case-control studies (3 in the general, 6 in occupational populations) were identified. Five/seven cohort studies in the general and occupational populations consist of 78,263/13, 434 participants with a mean follow-up of 12.1/43.0 years, respectively. Case-control studies include 334 cases/670 controls in the general population, and 1,315 cases/4,477 controls in occupational populations. Comparing the highest to the lowest category of cadmium exposure in the general population, the weighted relative risk of prostate cancer incidence and mortality among cohort studies, and the weighted odds ratio in case-control studies were 1.05 (95%CI [0.91, 1.22]), 0.83 (95%CI [0.35, 1.98]), and 1.27 (95%CI [0.58,2.78]), respectively. For occupational populations, the weighted OR in case-control studies was 1.17 (95%CI [0.85, 1.62]), and the weighted standardized mortality ratio in cohort studies was 98 (95%CI [75, 126]). Accumulated epidemiological evidence does not support the hypothesis that cadmium exposure may increase the risk of prostate cancer in either the general or occupational populations. PMID:27174617
Chen, Cheng; Xun, Pengcheng; Nishijo, Muneko; Carter, Sue; He, Ka
2016-05-13
We aimed to evaluate the association of cadmium exposure with the risk of prostate cancer in both the general and occupational populations. Online database searches were performed for studies of prostate cancer risk and cadmium exposure. Twelve cohort studies (5 in the general, 7 in occupational populations) and 9 case-control studies (3 in the general, 6 in occupational populations) were identified. Five/seven cohort studies in the general and occupational populations consist of 78,263/13, 434 participants with a mean follow-up of 12.1/43.0 years, respectively. Case-control studies include 334 cases/670 controls in the general population, and 1,315 cases/4,477 controls in occupational populations. Comparing the highest to the lowest category of cadmium exposure in the general population, the weighted relative risk of prostate cancer incidence and mortality among cohort studies, and the weighted odds ratio in case-control studies were 1.05 (95%CI [0.91, 1.22]), 0.83 (95%CI [0.35, 1.98]), and 1.27 (95%CI [0.58,2.78]), respectively. For occupational populations, the weighted OR in case-control studies was 1.17 (95%CI [0.85, 1.62]), and the weighted standardized mortality ratio in cohort studies was 98 (95%CI [75, 126]). Accumulated epidemiological evidence does not support the hypothesis that cadmium exposure may increase the risk of prostate cancer in either the general or occupational populations.
Prevalence and incidence of hypertension from 1995 to 2005: a population-based study.
Tu, Karen; Chen, Zhongliang; Lipscombe, Lorraine L
2008-05-20
Researchers have predicted that there will be a relative increase of 24% in the prevalence of hypertension in developed countries from 2000 to 2025. Hypertension is a leading risk factor for death, stroke, cardiovascular disease and renal disease. Thus, accurate estimates of the prevalence of hypertension in a population have important implications for public policy. We sought to assess whether the estimated increase in the prevalence of hypertension has been underestimated. We performed a population-based cohort study using linked administrative data for adults aged 20 years and older in Ontario, Canada's most populous province with more than 12 million residents. Using a validated case-definition algorithm for hypertension, we examined trends in prevalence from 1995 to 2005 and in incidence from 1997 to 2004. The number of adults with hypertension more than doubled from 1995 to 2005. The age- and sex-adjusted prevalence increased from 153.1 per 1000 adults in 1995 to 244.8 per 1000 in 2005, which was a relative increase of 60.0% (p < 0.001). The age- and sex-adjusted incidence of hypertension increased from 25.5 per 1000 adults in 1997 to 32.1 per 1000 in 2004, which was a relative increase of 25.7% (p < 0.001). Our findings indicate that the rise in hypertension prevalence will likely far exceed the predicted prevalence for 2025. Public health strategies to prevent and manage hypertension and its sequelae are urgently needed.
Prevalence and incidence of hypertension from 1995 to 2005: a population-based study
Tu, Karen; Chen, Zhongliang; Lipscombe, Lorraine L.
2008-01-01
Background Researchers have predicted that there will be a relative increase of 24% in the prevalence of hypertension in developed countries from 2000 to 2025. Hypertension is a leading risk factor for death, stroke, cardiovascular disease and renal disease. Thus, accurate estimates of the prevalence of hypertension in a population have important implications for public policy. We sought to assess whether the estimated increase in the prevalence of hypertension has been underestimated. Methods We performed a population-based cohort study using linked administrative data for adults aged 20 years and older in Ontario, Canada's most populous province with more than 12 million residents. Using a validated case-definition algorithm for hypertension, we examined trends in prevalence from 1995 to 2005 and in incidence from 1997 to 2004. Results The number of adults with hypertension more than doubled from 1995 to 2005. The age-and sex-adjusted prevalence increased from 153.1 per 1000 adults in 1995 to 244.8 per 1000 in 2005, which was a relative increase of 60.0% (p < 0.001). The age-and sex-adjusted incidence of hypertension increased from 25.5 per 1000 adults in 1997 to 32.1 per 1000 in 2004, which was a relative increase of 25.7% (p < 0.001). Interpretation Our findings indicate that the rise in hypertension prevalence will likely far exceed the predicted prevalence for 2025. Public health strategies to prevent and manage hypertension and its sequelae are urgently needed. PMID:18490638
Persson, I; Granath, F; Askling, J; Ludvigsson, J F; Olsson, T; Feltelius, N
2014-02-01
To investigate the association between vaccination with Pandemrix and risk of selected neurological and immune-related diseases including narcolepsy. Population-based prospective cohort study using data from regional vaccination registries and national health registries. Seven healthcare regions in Sweden comprising 61% of the Swedish population. Study population of 3,347,467 vaccinated and 2,497,572 nonvaccinated individuals (vaccination coverage ≈ 60%) followed between 2009 and 2011 for 6.9 million person-years after exposure and 6.0 million person-years without exposure. First recorded diagnosis of neurological and immune-related diseases. Relative risks [hazard ratios (HRs) with 95% confidence intervals (CIs)] assessed using Cox regression, adjusted for covariates. For all selected neurological and immune-related outcomes under study, other than allergic vaccine reactions (for which we verified an expected increase in risk) and narcolepsy, HRs were close to 1.0 and always below 1.3. We observed a three-fold increased risk of a diagnosis of narcolepsy (HR: 2.92, 95% CI: 1.78-4.79; that is, four additional cases per 100,000 person-years) in individuals ≤ 20 years of age at vaccination and a two-fold increase (HR: 2.18, 95% CI: 1.00-4.75) amongst young adults between 21 and 30 years of age. The excess risk declined successively with increasing age at vaccination; no increase in risk was seen after 40 years of age. For a large number of selected neurological and immune-related diseases, we could neither confirm any causal association with Pandemrix nor refute entirely a small excess risk. We confirmed an increased risk for a diagnosis of narcolepsy in individuals ≤ 20 years of age and observed a trend towards an increased risk also amongst young adults between 21 and 30 years. © 2013 The Association for the Publication of the Journal of Internal Medicine.
[Food and population: study of three countries].
1988-12-01
In 1985, despite a nearly 25% worldwide surplus of cereals, more than 700 million poor people had insufficient food and some 17 million children died of malnutrition or related causes. 16% of the developing world's population is undernourished. Rapid population growth is a major reason for the world's hunger. Large families exhaust the resources of many urban couples and rural couples with little land. Closely spaced pregnancies deplete the nutritional resources of the mother and lead to low birth weight babies and inadequate lactation. Population growth in already densely populated countries reduces the land available for each family, inevitably contributing to poverty and rural malnutrition. Unemployment and underemployment reach alarming proportions in the city, where the combination of high fertility rates and migration from the countryside have produced growth twice that of the world population as a whole. Few developing countries have been able to generate sufficient investment to create new jobs for all seeking them. Unstable governments attempt to pacify urban unrest by subsidizing food prices and concentrating social and economic investments in the cities, causing further deterioration in rural conditions. Today more than 60 countries have food deficits, although not all are suffering. India, Kenya, and Mexico are 3 countries that have had some success in balancing population growth and food production, but each still has undernourished population sectors because of economic policies that fail to provide sufficient help to their poor and because of implacable population growth. Ending malnutrition in the 3 countries will require reducing the cost of food for households and increasing their incomes, but both objectives are made more difficult by rapid population growth. As a result of the green revolution and other factors, food production in India has tripled since 1950, but population has almost doubled in the same years. With rapid population growth, per capita agricultural productivity increased much more slowly than production. Kenya has enjoyed impressive economic growth since independence, but its rate of population growth of 4.2%/year, the highest in the world, has meant that per capita income increases have been modest. Average nutritional status has declined in Kenya since 1968. The rate of population growth in Mexico has declined to 2.3-2.6%/year in 1986 from the 3.5% of 1974, but population growth will be rapid for decades to come because of the young age structure. Agricultural production has increased but has not kept pace with population growth. Kenya, India, and Mexico have the human and natural resources to make further economic gains in the coming decades. The difficulty of feeding their populations adequately will increase to the extent that they fail to curb their rapid population increase.
Cold periods and coronary events: an analysis of populations worldwide
Barnett, A.; Dobson, A.; McElduff, P.; Salomaa, V.; Kuulasmaa, K.; Sans, S.; t for
2005-01-01
Study objective: To investigate the association between cold periods and coronary events, and the extent to which climate, sex, age, and previous cardiac history increase risk during cold weather. Design: A hierarchical analyses of populations from the World Health Organisation's MONICA project. Setting: Twenty four populations from the WHO's MONICA project, a 21 country register made between 1980 and 1995. Patients: People aged 35–64 years who had a coronary event. Main results: Daily rates of coronary events were correlated with the average temperature over the current and previous three days. In cold periods, coronary event rates increased more in populations living in warm climates than in populations living in cold climates, where the increases were slight. The increase was greater in women than in men, especially in warm climates. On average, the odds for women having an event in the cold periods were 1.07 higher than the odds for men (95% posterior interval: 1.03 to 1.11). The effects of cold periods were similar in those with and without a history of a previous myocardial infarction. Conclusions: Rates of coronary events increased during comparatively cold periods, especially in warm climates. The smaller increases in colder climates suggest that some events in warmer climates are preventable. It is suggested that people living in warm climates, particularly women, should keep warm on cold days. PMID:15965137
Lawless, Conor; Jurk, Diana; Gillespie, Colin S; Shanley, Daryl; Saretzki, Gabriele; von Zglinicki, Thomas; Passos, João F
2012-01-01
Increases in cellular Reactive Oxygen Species (ROS) concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells.One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage). However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS). We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence.
Lawless, Conor; Jurk, Diana; Gillespie, Colin S.; Shanley, Daryl; Saretzki, Gabriele; von Zglinicki, Thomas; Passos, João F.
2012-01-01
Increases in cellular Reactive Oxygen Species (ROS) concentration with age have been observed repeatedly in mammalian tissues. Concomitant increases in the proportion of replicatively senescent cells in ageing mammalian tissues have also been observed. Populations of mitotic human fibroblasts cultured in vitro, undergoing transition from proliferation competence to replicative senescence are useful models of ageing human tissues. Similar exponential increases in ROS with age have been observed in this model system. Tracking individual cells in dividing populations is difficult, and so the vast majority of observations have been cross-sectional, at the population level, rather than longitudinal observations of individual cells. One possible explanation for these observations is an exponential increase in ROS in individual fibroblasts with time (e.g. resulting from a vicious cycle between cellular ROS and damage). However, we demonstrate an alternative, simple hypothesis, equally consistent with these observations which does not depend on any gradual increase in ROS concentration: the Stochastic Step Model of Replicative Senescence (SSMRS). We also demonstrate that, consistent with the SSMRS, neither proliferation-competent human fibroblasts of any age, nor populations of hTERT overexpressing human fibroblasts passaged beyond the Hayflick limit, display high ROS concentrations. We conclude that longitudinal studies of single cells and their lineages are now required for testing hypotheses about roles and mechanisms of ROS increase during replicative senescence. PMID:22359661
Vanasse, Alain; Cohen, Alan; Courteau, Josiane; Bergeron, Patrick; Dault, Roxanne; Gosselin, Pierre; Blais, Claudia; Bélanger, Diane; Rochette, Louis; Chebana, Fateh
2016-01-01
Background: Floods represent a serious threat to human health beyond the immediate risk of drowning. There is few data on the potential link between floods and direct consequences on health such as on cardiovascular health. This study aimed to explore the impact of one of the worst floods in the history of Quebec, Canada on acute cardiovascular diseases (CVD). Methods: A cohort study with a time series design with multiple control groups was built with the adult population identified in the Quebec Integrated Chronic Disease Surveillance System. A geographic information system approach was used to define the study areas. Logistic regressions were performed to compare the occurrence of CVD between groups. Results: The results showed a 25%–27% increase in the odds in the flooded population in spring 2011 when compared with the population in the same area in springs 2010 and 2012. Besides, an increase up to 69% was observed in individuals with a medical history of CVD. Conclusion: Despite interesting results, the association was not statistically significant. A possible explanation to this result can be that the population affected by the flood was probably too small to provide the statistical power to answer the question, and leaves open a substantial possibility for a real and large effect. PMID:26828511
Vanasse, Alain; Cohen, Alan; Courteau, Josiane; Bergeron, Patrick; Dault, Roxanne; Gosselin, Pierre; Blais, Claudia; Bélanger, Diane; Rochette, Louis; Chebana, Fateh
2016-01-28
Floods represent a serious threat to human health beyond the immediate risk of drowning. There is few data on the potential link between floods and direct consequences on health such as on cardiovascular health. This study aimed to explore the impact of one of the worst floods in the history of Quebec, Canada on acute cardiovascular diseases (CVD). A cohort study with a time series design with multiple control groups was built with the adult population identified in the Quebec Integrated Chronic Disease Surveillance System. A geographic information system approach was used to define the study areas. Logistic regressions were performed to compare the occurrence of CVD between groups. The results showed a 25%-27% increase in the odds in the flooded population in spring 2011 when compared with the population in the same area in springs 2010 and 2012. Besides, an increase up to 69% was observed in individuals with a medical history of CVD. Despite interesting results, the association was not statistically significant. A possible explanation to this result can be that the population affected by the flood was probably too small to provide the statistical power to answer the question, and leaves open a substantial possibility for a real and large effect.
Basu, Sanjay; King, Abby C
2013-12-01
Chronic noncommunicable diseases (NCDs) are now prevalent in many low- and middle-income countries and confer a heightened risk of disability. It is unclear how public health programs can identify the older adults at highest risk of disability related to NCDs within diverse developing country populations. We studied nationally representative survey data from 7,150 Indian adults older than 50 years of age who participated in the World Health Organization Study on Global Aging and Adult Health (2007-2010) to identify population subgroups who are highly disabled. Using machine-learning algorithms, we identified sociodemographic correlates of disability. Although having 2 or more symptomatic NCDs was a key correlate of disability, the prevalence of symptomatic, undiagnosed NCDs was highest among the lowest 2 wealth quintiles of Indian adults, contrary to prior hypotheses of increased NCDs with wealth. Women and persons from rural populations were also disproportionately affected by nondiagnosed NCDs, with high out-of-pocket health care expenditures increasing the probability of remaining symptomatic from NCDs. These findings also indicate that NCD prevalence surveillance studies in low- and middle-income countries should expand beyond self-reported diagnoses to include more extensive symptom- and examination-based surveys, given the likely high rate of surveillance bias due to barriers to diagnosis among vulnerable populations.
Ameca y Juárez, Eric I; Ellis, Edward A; Rodríguez-Luna, Ernesto
2015-07-01
Long-term studies quantifying impacts of hurricane activity on growth and trajectory of primate populations are rare. Using a 14-year monitored population of Alouatta palliata mexicana as a study system, we developed a modeling framework to assess the relative contribution of hurricane disturbance and two types of human impacts, habitat loss, and hunting, on quasi-extinction risk. We found that the scenario with the highest level of disturbance generated a 21% increase in quasi-extinction risk by 40 years compared to scenarios of intermediate disturbance, and around 67% increase relative to that found in low disturbance scenarios. We also found that the probability of reaching quasi-extinction due to human disturbance alone was below 1% by 40 years, although such scenarios reduced population size by 70%, whereas the risk of quasi-extinction ranged between 3% and 65% for different scenarios of hurricane severity alone, in absence of human impacts. Our analysis moreover found that the quasi-extinction risk driven by hunting and hurricane disturbance was significantly lower than the quasi-extinction risk posed by human-driven habitat loss and hurricane disturbance. These models suggest that hurricane disturbance has the potential to exceed the risk posed by human impacts, and, in particular, to substantially increase the speed of the extinction vortex driven by habitat loss relative to that driven by hunting. Early mitigation of habitat loss constituted the best method for reducing quasi-extinction risk: the earlier habitat loss is halted, the less vulnerable the population becomes to hurricane disturbance. By using a well-studied population of A. p. mexicana, we help understand the demographic impacts that extreme environmental disturbance can trigger on isolated populations of taxa already endangered in other systems where long-term demographic data are not available. For those experiencing heavy anthropogenic pressure and lacking sufficiently evolved coping strategies against unpredictable environmental disturbance, the risk of population extinction can be exacerbated. © 2015 Wiley Periodicals, Inc.
Serum osteoprotegerin and renal function in the general population: the Tromsø Study.
Vik, Anders; Brodin, Ellen E; Mathiesen, Ellisiv B; Brox, Jan; Jørgensen, Lone; Njølstad, Inger; Brækkan, Sigrid K; Hansen, John-Bjarne
2017-02-01
Serum osteoprotegerin (OPG) is elevated in patients with chronic kidney disease (CKD) and increases with decreasing renal function. However, there are limited data regarding the association between OPG and renal function in the general population. The aim of the present study was to explore the relation between serum OPG and renal function in subjects recruited from the general population. We conducted a cross-sectional study with 6689 participants recruited from the general population in Tromsø, Norway. Estimated glomerular filtration rate (eGFR) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equations. OPG was modelled both as a continuous and categorical variable. General linear models and linear regression with adjustment for possible confounders were used to study the association between OPG and eGFR. Analyses were stratified by the median age, as serum OPG and age displayed a significant interaction on eGFR. In participants ≤62.2 years with normal renal function (eGFR ≥90 mL/min/1.73 m 2 ) eGFR increased by 0.35 mL/min/1.73 m 2 (95% CI 0.13-0.56) per 1 standard deviation (SD) increase in serum OPG after multiple adjustment. In participants older than the median age with impaired renal function (eGFR <90 mL/min/1.73 m 2 ), eGFR decreased by 1.54 (95% CI -2.06 to -1.01) per 1 SD increase in serum OPG. OPG was associated with an increased eGFR in younger subjects with normal renal function and with a decreased eGFR in older subjects with reduced renal function. Our findings imply that the association between OPG and eGFR varies with age and renal function.
ALS and the Military: A Population-Based Study in the Danish Registries
Seals, Ryan M.; Kioumourtzoglou, Marianthi-Anna; Gredal, Ole; Hansen, Johnni; Weisskopf, Marc G.
2016-01-01
Background Prior studies have suggested that military service may be associated with the development of amyotrophic lateral sclerosis. We conducted a population-based case-control study in Denmark to assess whether occupation in the Danish military is associated with an increased risk of developing amyotrophic lateral sclerosis. Methods There were 3,650 incident cases of amyotrophic lateral sclerosis recorded in the Danish National Patient Registry between 1982 and 2009. Each case was matched to 100 age- and sex-matched population controls alive and free of amyotrophic lateral sclerosis on the date of the case diagnosis. Comprehensive occupational history was obtained from the Danish Pension Fund database, which began in 1964. Results 2.4% (n=8,922) of controls had a history of employment in the military prior to the index date. Military employees overall had an elevated rate of ALS (OR=1.3; 95% CI: 1.1-1.6). A ten-year increase in years employed by the military was associated with an odds ratio of 1.2 (95% CI: 1.0-1.4), and all quartiles of time employed were elevated. There was little suggestion of a pattern across calendar year of first employment, but there was some evidence that increasing age at first employment was associated with increased ALS rates. Rates were highest in the decade immediately following the end of employment (OR=1.6; 95% CI: 1.2-2.2). Conclusions In this large population-based case-control study, employment by the military is associated with increased rates of ALS. These findings are consistent with earlier findings that military service or employment may entail exposure to risk factors for ALS. PMID:26583610
Xie, Shu-Zhe; Liu, Zhi-Zhong; Yu, Jun-hua; Liu, Li; Wang, Wei; Xie, Dao-Lin; Qin, Jiang-Bo
2015-11-01
Many molecular epidemiological studies have been performed to explore the association between MTHFR C677T polymorphism and cancer risk in diverse populations. However, the results were inconsistent. Hence, we performed a meta-analysis to investigate the association between cancer risk and MTHFR C677T (150,086 cases and 200,699 controls from 446 studies) polymorphism. Overall, significantly increased cancer risk was found when all eligible studies were pooled into the meta-analysis. In the further stratified and sensitivity analyses, significantly increased breast cancer risk was found in Asians and Indians, significantly decreased colon cancer risk was found, significantly decreased colorectal cancer risk was found in male population, significantly increased gastric cancer risk was found in Caucasians and Asians, significantly increased hepatocellular cancer risk was found in Asians, significantly decreased adult acute lymphoblastic leukemia (AALL) risk was found in Caucasians, significantly decreased childhood acute lymphoblastic leukemia (CALL) risk was found in Asians, and significantly increased multiple myeloma and NHL risk was found in Caucasians. In summary, this meta-analysis suggests that MTHFR C677T polymorphism is associated with increased breast cancer, gastric cancer, and hepatocellular cancer risk in Asians, is associated with increased gastric cancer, multiple myeloma, and NHL risk in Caucasians, is associated with decreased AALL risk in Caucasians, is associated with decreased CALL risk in Asians, is associated with increased breast cancer risk in Asians, is associated with decreased colon cancer risk, and is associated with decreased colorectal cancer risk in male population. Moreover, this meta-analysis also points out the importance of new studies, such as Asians of HNC, Asians of lung cancer, and Indians of breast cancer, because they had high heterogeneity in this meta-analysis (I(2) > 75%).
Evidence of population resistance to extreme low flows in a fluvial-dependent fish species
Katz, Rachel A.; Freeman, Mary C.
2015-01-01
Extreme low streamflows are natural disturbances to aquatic populations. Species in naturally intermittent streams display adaptations that enhance persistence during extreme events; however, the fate of populations in perennial streams during unprecedented low-flow periods is not well-understood. Biota requiring swift-flowing habitats may be especially vulnerable to flow reductions. We estimated the abundance and local survival of a native fluvial-dependent fish species (Etheostoma inscriptum) across 5 years encompassing historic low flows in a sixth-order southeastern USA perennial river. Based on capturemark-recapture data, the study shoal may have acted as a refuge during severe drought, with increased young-of-the-year (YOY) recruitment and occasionally high adult immigration. Contrary to expectations, summer and autumn survival rates (30 days) were not strongly depressed during low-flow periods, despite 25%-80% reductions in monthly discharge. Instead, YOY survival increased with lower minimum discharge and in response to small rain events that increased low-flow variability. Age-1+ fish showed the opposite pattern, with survival decreasing in response to increasing low-flow variability. Results from this population dynamics study of a small fish in a perennial river suggest that fluvial-dependent species can be resistant to extreme flow reductions through enhanced YOY recruitment and high survival
Piotrow, P T
1993-06-01
Some of the history and special features of the US population assistance program administered by USAID are recounted. Future predictions are also made for funding and new directions for the US population assistance program and environmental issues. The topics addressed were part of a talk given in 1992 at a meeting of the Council on Population Education held in Tokyo. Credit is given to Japan for its contribution to family planning (FP) efforts by setting an example of reducing population size within a decade and providing financial support internationally. Japan's example so impressed General William H. Draper, Jr. that he worked for the establishment of the USAID and the UN Population Fund, and funding for the International Planned Parenthood Federation. He encouraged Japanese officials to provide support for international population and (FP) programs. Currently, the US provides $350 million in population assistance. Encouragement was given for Japan to increase its international commitment of $80 million and to contribute to the Johns Hopkins University William H. Draper, Jr., fellowship fund for graduate students from developing countries to study modern health communication. The special features of the US population assistance program were identified as follows: 1) high funding levels, 2) availability of FP services, 3) adequate contraceptive supplies, 4) availability of professional population staff, and 5) an emphasis on data and evaluation. The single most important element of the USAID program is the reliance on private, nongovernmental organizations (NGOs), which can establish flexible, independent, innovative and cost- effective programs. Predictions for the future were that the US Congress would expand overseas population assistance. Domestic policy will have priority, and the future will depend on who occupies the key policy positions at the State Department and USAID. THere will be more emphasis on free political elections, on humanitarian issues, and on environmental issues. New directions will be to increase funding, reduce restrictions on population assistance, increase support for NGOs, expand FP communication programs, improve the quality of FP services, increase distribution of condoms, and increase coordination among donors. The enter educate approach to promoting FP is described.
NASA Astrophysics Data System (ADS)
Harrington, Luke J.; Otto, Friederike E. L.
2018-03-01
Understanding how continuing increases in global mean temperature will exacerbate societal exposure to extreme weather events is a question of profound importance. However, determining population exposure to the impacts of heat extremes at 1.5 °C and 2 °C of global mean warming requires not only (1) a robust understanding of the physical climate system response, but also consideration of (2) projected changes to overall population size, as well as (3) changes to where people will live in the future. This analysis introduces a new framework, adapted from studies of probabilistic event attribution, to disentangle the relative importance of regional climate emergence and changing population dynamics in the exposure to future heat extremes across multiple densely populated regions in Southern Asia and Eastern Africa (SAEA). Our results reveal that, when population is kept at 2015 levels, exposure to heat considered severe in the present decade across SAEA will increase by a factor of 4.1 (2.4-9.6) and 15.8 (5.0-135) under a 1.5°- and 2.0°-warmer world, respectively. Furthermore, projected population changes by the end of the century under an SSP1 and SSP2 scenario can further exacerbate these changes by a factor of 1.2 (1.0-1.3) and 1.5 (1.3-1.7), respectively. However, a large fraction of this additional risk increase is not related to absolute increases in population, but instead attributed to changes in which regions exhibit continued population growth into the future. Further, this added impact of population redistribution will be twice as significant after 2.0 °C of warming, relative to stabilisation at 1.5 °C, due to the non-linearity of increases in heat exposure. Irrespective of the population scenario considered, continued African population expansion will place more people in locations where emergent changes to future heat extremes are exceptionally severe.
Mullins, C R; Mamedova, L K; Carpenter, A J; Ying, Y; Allen, M S; Yoon, I; Bradford, B J
2013-09-01
The rumen microbial ecosystem is a critical factor that links diets to bovine physiology and productivity; however, information about dietary effects on microbial populations has generally been limited to small numbers of samples and qualitative assessment. To assess whether consistent shifts in microbial populations occur in response to common dietary manipulations in dairy cattle, samples of rumen contents were collected from 2 studies for analysis by quantitative real-time PCR (qPCR). In one study, lactating Holstein cows (n=8) were fed diets in which a nonforage fiber source replaced an increasing proportion of forages and concentrates in a 4×4 Latin square design, and samples of ruminal digesta were collected at 9-h intervals over 3 d at the end of each period. In the second study, lactating Holstein cows (n=15) were fed diets with or without the inclusion of a Saccharomyces cerevisiae fermentation product (SCFP) in a crossover design. In this study, rumen liquid and solid samples were collected during total rumen evacuations before and after feeding in a 42-h period. In total, 146 samples of ruminal digesta were used for microbial DNA isolation and analysis by qPCR. Validated primer sets were used to quantify total bacterial and anaerobic fungal populations as well as 12 well-studied bacterial taxa. The relative abundance of the target populations was similar to those previously reported. No significant treatment effects were observed for any target population. A significant interaction of treatment and dry matter intake was observed, however, for the abundance of Eubacterium ruminantium. Increasing dry matter intake was associated with a quadratic decrease in E. ruminantium populations in control animals but with a quadratic increase in E.ruminantium populations in cows fed SCFP. Analysis of sample time effects revealed that Fibrobacter succinogenes and fungal populations were more abundant postfeeding, whereas Ruminococcus albus tended to be more abundant prefeeding. Seven of the target taxa were more abundant in either the liquid or solid fractions of ruminal digesta. By accounting for the total mass of liquid and solid fractions in the rumen and the relative abundance of total bacteria in each fraction, it was estimated that 92% of total bacteria were found in the solid digesta fraction. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.
Horn, Johannes; Damm, Oliver; Greiner, Wolfgang; Hengel, Hartmut; Kretzschmar, Mirjam E; Siedler, Anette; Ultsch, Bernhard; Weidemann, Felix; Wichmann, Ole; Karch, André; Mikolajczyk, Rafael T
2018-01-09
Epidemiological studies suggest that reduced exposure to varicella might lead to an increased risk for herpes zoster (HZ). Reduction of exposure to varicella is a consequence of varicella vaccination but also of demographic changes. We analyzed how the combination of vaccination programs and demographic dynamics will affect the epidemiology of varicella and HZ in Germany over the next 50 years. We used a deterministic dynamic compartmental model to assess the impact of different varicella and HZ vaccination strategies on varicella and HZ epidemiology in three demographic scenarios, namely the projected population for Germany, the projected population additionally accounting for increased immigration as observed in 2015/2016, and a stationary population. Projected demographic changes alone result in an increase of annual HZ cases by 18.3% and a decrease of varicella cases by 45.7% between 1990 and 2060. Independently of the demographic scenario, varicella vaccination reduces the cumulative number of varicella cases until 2060 by approximately 70%, but also increases HZ cases by 10%. Unlike the currently licensed live attenuated HZ vaccine, the new subunit vaccine candidate might completely counteract this effect. Relative vaccine effects were consistent across all demographic scenarios. Demographic dynamics will be a major determinant of HZ epidemiology in the next 50 years. While stationary population models are appropriate for assessing vaccination impact, models incorporating realistic population structures allow a direct comparison to surveillance data and can thus provide additional input for immunization decision-making and resource planning.
Social activity, cognitive decline and dementia risk: a 20-year prospective cohort study.
Marioni, Riccardo E; Proust-Lima, Cecile; Amieva, Helene; Brayne, Carol; Matthews, Fiona E; Dartigues, Jean-Francois; Jacqmin-Gadda, Helene
2015-10-24
Identifying modifiable lifestyle correlates of cognitive decline and risk of dementia is complex, particularly as few population-based longitudinal studies jointly model these interlinked processes. Recent methodological developments allow us to examine statistically defined sub-populations with separate cognitive trajectories and dementia risks. Engagement in social, physical, or intellectual pursuits, social network size, self-perception of feeling well understood, and degree of satisfaction with social relationships were assessed in 2854 participants from the Paquid cohort (mean baseline age 77 years) and related to incident dementia and cognitive change over 20-years of follow-up. Multivariate repeated cognitive information was exploited by defining the global cognitive functioning as the latent common factor underlying the tests. In addition, three latent homogeneous sub-populations of cognitive change and dementia were identified and contrasted according to social environment variables. In the whole population, we found associations between increased engagement in social, physical, or intellectual pursuits and increased cognitive ability (but not decline) and decreased risk of incident dementia, and between feeling understood and slower cognitive decline. There was evidence for three sub-populations of cognitive aging: fast, medium, and no cognitive decline. The social-environment measures at baseline did not help explain the heterogeneity of cognitive decline and incident dementia diagnosis between these sub-populations. We observed a complex series of relationships between social-environment variables and cognitive decline and dementia. In the whole population, factors such as increased engagement in social, physical, or intellectual pursuits were related to a decreased risk of dementia. However, in a sub-population analysis, the social-environment variables were not linked to the heterogeneous patterns of cognitive decline and dementia risk that defined the sub-groups.
Jorgenson, Andrew K; Clark, Brett
2013-01-01
This study examines the regional and temporal differences in the statistical relationship between national-level carbon dioxide emissions and national-level population size. The authors analyze panel data from 1960 to 2005 for a diverse sample of nations, and employ descriptive statistics and rigorous panel regression modeling techniques. Initial descriptive analyses indicate that all regions experienced overall increases in carbon emissions and population size during the 45-year period of investigation, but with notable differences. For carbon emissions, the sample of countries in Asia experienced the largest percent increase, followed by countries in Latin America, Africa, and lastly the sample of relatively affluent countries in Europe, North America, and Oceania combined. For population size, the sample of countries in Africa experienced the largest percent increase, followed countries in Latin America, Asia, and the combined sample of countries in Europe, North America, and Oceania. Findings for two-way fixed effects panel regression elasticity models of national-level carbon emissions indicate that the estimated elasticity coefficient for population size is much smaller for nations in Africa than for nations in other regions of the world. Regarding potential temporal changes, from 1960 to 2005 the estimated elasticity coefficient for population size decreased by 25% for the sample of Africa countries, 14% for the sample of Asia countries, 6.5% for the sample of Latin America countries, but remained the same in size for the sample of countries in Europe, North America, and Oceania. Overall, while population size continues to be the primary driver of total national-level anthropogenic carbon dioxide emissions, the findings for this study highlight the need for future research and policies to recognize that the actual impacts of population size on national-level carbon emissions differ across both time and region.
Raheel, Shafay; Shbeeb, Izzat; Crowson, Cynthia S; Matteson, Eric L
2017-08-01
To determine time trends in the incidence and survival of polymyalgia rheumatica (PMR) over a 15-year period in Olmsted County, Minnesota, and to examine trends in incidence of PMR in the population by comparing this time period to a previous incidence cohort from the same population base. All cases of incident PMR among Olmsted County, Minnesota residents in 2000-2014 were identified to extend the previous 1970-1999 cohort. Detailed review of all individual medical records was performed. Incidence rates were age- and sex-adjusted to the US white 2010 population. Survival rates were compared with the expected rates in the population of Minnesota. There were 377 incident cases of PMR during the 15-year study period. Of these, 64% were female and the mean age at incidence was 74.1 years. The overall age- and sex-adjusted annual incidence of PMR was 63.9 (95% confidence interval [95% CI] 57.4-70.4) per 100,000 population ages ≥50 years. Incidence rates increased with age in both sexes, but incidence fell after age 80 years. There was a slight increase in incidence of PMR in the recent time period compared to 1970-1999 (P = 0.063). Mortality among individuals with PMR was not significantly worse than that expected in the general population (standardized mortality ratio 0.70 [95% CI 0.57-0.85]). The incidence of PMR has increased slightly in the past 15 years compared to previous decades. Survivorship in patients with PMR is not worse than in the general population. © 2016, American College of Rheumatology.
Crespi, Catherine M; Vergara, Ximena P; Hooper, Chris; Oksuzyan, Sona; Wu, Sheng; Cockburn, Myles; Kheifets, Leeka
2016-01-01
Background: Studies have reported an increased risk of childhood leukaemia associated with living near high-voltage electric power transmission lines that extend to distances at which magnetic fields from lines are negligible. We conducted a large records-based case-control study of childhood leukaemia risk in the population living near power lines in California. Methods: The study included 5788 childhood leukaemia and 3308 central nervous system (CNS) cancer cases (for comparison) born in and diagnosed in California (1986–2008), and matched to population-based controls by age and sex. We geocoded birth address and estimated the distance from residence to transmission lines using geographic information systems, aerial imagery, and, for some residences, site visits. Results: For leukaemia, there was a slight excess of cases within 50 m of a transmission line over 200 kV (odds ratio 1.4, 95% confidence interval 0.7–2.7). There was no evidence of increased risk for distances beyond 50 m, for lower-voltage lines, or for CNS cancers. Conclusions: Our findings did not clearly support an increased childhood leukaemia risk associated with close proximity (<50 m) to higher voltage lines, but could be consistent with a small increased risk. Reports of increased risk for distances beyond 50 m were not replicated. PMID:27219016
The prevalence of artificial lens implants in the civil airman population.
DOT National Transportation Integrated Search
1992-03-01
The use of artificial lens implants to correct for aphakia has become increasingly prevalent in the United States. This study analyzes the distribution of intraocular lens (IOL) implants in the civil airman population by type (unilateral bilateral), ...
Megaregion freight movements : a case study of the Texas Triangle.
DOT National Transportation Integrated Search
2011-09-01
U.S. population growth is predicted to substantially increase over the next 40 years, particularly in areas with large regional economies forecasted to contain over two-thirds of the national economic activity. In Texas, population growth from 2000 t...
Mega-region freight movements : a case study of the Texas triangle.
DOT National Transportation Integrated Search
2011-09-01
U.S. population growth is predicted to substantially increase over the next 40 years, particularly in areas : with large regional economies forecasted to contain over two-thirds of the national economic activity. In : Texas, population growth from 20...
Trends in mortality and biological stress in a medieval polish urban population.
Betsinger, Tracy K; DeWitte, Sharon
2017-12-01
Urbanization in pre-modern populations may have had a variety of consequences related to population crowding. However, research on the effects of urbanization have provided inconsistent results regarding the biological impact of this transition on human populations. The purpose of this study is to test the hypothesis that urbanization caused an increase in overall biological stress in a medieval (10th-13th centuries AD) Polish population. A human skeletal sample (n=164) was examined for the presence of porotic hyperostosis, cribra orbitalia, linear enamel hypoplasia, periosteal reaction, and specific infectious diseases. Prevalence rates were compared among three temporal samples: initial urbanization, early urbanization, and later urbanization. Results indicate no significant trends for any of the pathological conditions. Cox proportional hazards analyses, however, revealed a significant increase in the risk of death over time, which supports the hypothesis. These results reflect the necessity of using multiple analyses to address bioarchaeological questions. The lack of significant results from skeletal indicators may be due to an earlier urbanization trend in the population. This study illustrates that the association of urbanization with elevated biological stress is complicated and dependent on various factors, including culture and time period. Copyright © 2017 Elsevier Inc. All rights reserved.
Vitart, Veronique; Carothers, Andrew D; Hayward, Caroline; Teague, Peter; Hastie, Nicholas D; Campbell, Harry; Wright, Alan F
2005-05-01
Few studies have investigated genetic differentiation within nonisolate European populations, despite the initiation of large national sample collections such as U.K. Biobank. Here, we used short tandem repeat markers to explore fine-scale genetic structure and to examine the extent of linkage disequilibrium (LD) within national subpopulations. We studied 955 unrelated individuals of local ancestry from nine Scottish rural regions and the urban center of Edinburgh, as well as 96 unrelated individuals from the general U.K. population. Despite little overall differentiation on the basis of allele frequencies, there were clear differences among subpopulations in the extent of pairwise LD, measured between a subset of X-linked markers, that reflected presumed differences in the depths of the underlying genealogies within these subpopulations. Therefore, there are strategic advantages in studying rural subpopulations, in terms of increased power and reduced cost, that are lost by sampling across regions or within urban populations. Similar rural-urban contrasts are likely to exist in many other populations with stable rural subpopulations, which could influence the design of genetic association studies and national biobank data collections.
da Silva, Ellen Moreno; Fernandes, Marianne Rodrigues; de Carvalho, Darlen Cardoso; Leitao, Luciana Pereira Colares; Cavalcante, Giovanna Chaves; Pereira, Esdras Edgar Batista; Modesto, Antônio André Conde; Guerreiro, João Farias; de Assumpção, Paulo Pimentel; Dos Santos, Sidney Emanuel Batista; Dos Santos, Ney Pereira Carneiro
2017-11-29
Global literature describes differences in the incidence of gastric cancer among populations. For instance, Europeans have lower incidence rates of gastric cancer in relation to Latin and Asian populations, particularly Korean and Japanese populations. However, only a few studies have been able to verify the occurrence of gastric cancer in admixed populations with high interethnic degree mix, such as the Brazilian Amazon region. We observed an increase in European ancestry in the control group compared to the case group (47% vs. 41%). Using increments of 10%, compared to categorical distribution of European ancestry in the sample, we found a difference in the contribution between cases and controls (p = 0.03). Multiple logistic regression was performed to determine the influence of European ancestry in susceptibility to gastric cancer in the sample. According to the adopted model, for each 10% increase in European ancestry, there is a 20% decrease chance of developing gastric cancer (P = 0.0121; OR = 0.81; 95% CI 0.54-0.83). Overall, the results suggest that a greater contribution of European ancestry can be a protective factor for the development of gastric cancer in the studied Amazon population. It can help to establish protocols able to predict susceptibility to gastric cancer in admixed populations.
Decreased winter severity increases viability of a montane frog population
McCaffery, Rebecca M.; Maxell, Bryce A.
2010-01-01
Many proximate causes of global amphibian declines have been well documented, but the role that climate change has played and will play in this crisis remains ambiguous for many species. Breeding phenology and disease outbreaks have been associated with warming temperatures, but, to date, few studies have evaluated effects of climate change on individual vital rates and subsequent population dynamics of amphibians. We evaluated relationships among local climate variables, annual survival and fecundity, and population growth rates from a 9-year demographic study of Columbia spotted frogs (Rana luteiventris) in the Bitterroot Mountains of Montana. We documented an increase in survival and breeding probability as severity of winter decreased. Therefore, a warming climate with less severe winters is likely to promote population viability in this montane frog population. More generally, amphibians and other ectotherms inhabiting alpine or boreal habitats at or near their thermal ecological limits may benefit from the milder winters provided by a warming climate as long as suitable habitats remain intact. A more thorough understanding of how climate change is expected to benefit or harm amphibian populations at different latitudes and elevations is essential for determining the best strategies to conserve viable populations and allow for gene flow and shifts in geographic range. PMID:20421473
McLaughlin, Katie A.; Keyes, Katherine M.; Hasin, Deborah S.
2010-01-01
Objectives. We examined the relation between living in states that instituted bans on same-sex marriage during the 2004 and 2005 elections and the prevalence of psychiatric morbidity among lesbian, gay, and bisexual (LGB) populations. Methods. We used data from wave 1 (2001–2002) and wave 2 (2004–2005) of the National Epidemiologic Survey on Alcohol and Related Conditions (N = 34 653), a longitudinal, nationally representative study of noninstitutionalized US adults. Results. Psychiatric disorders defined by the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, increased significantly between waves 1 and 2 among LGB respondents living in states that banned gay marriage for the following outcomes: any mood disorder (36.6% increase), generalized anxiety disorder (248.2% increase), any alcohol use disorder (41.9% increase), and psychiatric comorbidity (36.3% increase). These psychiatric disorders did not increase significantly among LGB respondents living in states without constitutional amendments. Additionally, we found no evidence for increases of the same magnitude among heterosexuals living in states with constitutional amendments. Conclusions. Living in states with discriminatory policies may have pernicious consequences for the mental health of LGB populations. These findings lend scientific support to recent efforts to overturn these policies. PMID:20075314
Jensen, Elizabeth T; Hoffman, Kate; Shaheen, Nicholas J; Genta, Robert M; Dellon, Evan S
2014-05-01
Eosinophilic esophagitis (EoE) is an increasingly prevalent chronic disease arising from an allergy/immune-mediated process. Generally, the risk of atopic disease differs in rural and urban environments. The relationship between population density and EoE is unknown. Our aim was to assess the relationship between EoE and population density. We conducted a cross-sectional, case-control study of patients with esophageal biopsies in a US national pathology database between January 2009 and June 2012 to assess the relationship between population density and EoE. Using geographic information systems, the population density (individuals per square mile) was determined for each patient zip code. The odds of esophageal eosinophilia and EoE were estimated for each quintile of population density and adjusted for potential confounders. Sensitivity analyses were conducted with varying case definitions and to evaluate the potential for bias from endoscopy volume and patient factors. Of 292,621 unique patients in the source population, 89,754 had normal esophageal biopsies and 14,381 had esophageal eosinophilia with ≥15 eosinophils per high-power field. The odds of having esophageal eosinophilia increased with decreasing population density (P for trend <0.001). Compared with those in the highest quintile of population density, odds of having esophageal eosinophilia were significantly higher among those in the lowest quintile of population density (adjusted odds ratio (aOR) 1.27, 95% confidence interval (CI): 1.18, 1.36). A similar dose-response trend was observed across case definitions with increased odds of EoE in the lowest population density quintile (aOR 1.59, 95% CI: 1.45-1.76). Estimates were robust to sensitivity analyses. Population density is strongly and inversely associated with esophageal eosinophilia and EoE. This association is robust to varying case definitions and adjustment factors. Environmental exposures that are more prominent in rural areas may be relevant to the pathogenesis of EoE.
Jensen, Elizabeth T.; Hoffman, Kate; Shaheen, Nicholas J.; Genta, Robert M.; Dellon, Evan S.
2015-01-01
Objectives Eosinophilic esophagitis (EoE) is an increasingly prevalent chronic disease arising from an allergy/immune-mediated process. Generally, the risk of atopic disease differs in rural and urban environments. The relationship between population density and EoE is unknown. Our aim was to assess the relationship between EoE and population density. Methods : We conducted a cross-sectional, case-control study of patients with esophageal biopsies in a U.S. national pathology database between January 2009 and June 2012 to assess the relationship between population density and EoE. Using Geographic Information Systems (GIS), the population density (individuals/mile2) was determined for each patient zip code. The odds of esophageal eosinophilia and EoE were estimated for each quintile of population density and adjusted for potential confounders. Sensitivity analyses were conducted with varying case definitions and to evaluate the potential for bias from endoscopy volume and patient factors. Results Of 292,621 unique patients in the source population, 89,754 had normal esophageal biopsies and 14,381 had esophageal eosinophilia with ≥15 eosinophils per high-power field (eos/hpf). The odds of esophageal eosinophilia increased with decreasing population density (p for trend < 0.001). Compared to those in the highest quintile of population density, odds of esophageal eosinophilia were significantly higher amongst those in the lowest quintile of population density (aOR 1.27, 95% CI: 1.18, 1.36). A similar dose-response trend was observed across case definitions with odds of EoE increased in the lowest population density quintile (aOR 1.59, 95% CI: 1.45-1.76). Estimates were robust to sensitivity analyses. Conclusions Population density is strongly and inversely associated with esophageal eosinophilia and EoE. This association is robust to varying case definitions and adjustment factors. Environmental exposures more prominent in rural areas may be relevant to the pathogenesis of EoE. PMID:24667575
Concurrent alcohol and tobacco use among a middle-aged and elderly population in Mumbai.
Gupta, Prakash C; Maulik, Pallab K; Pednekar, Mangesh S; Saxena, Shekhar
2005-01-01
The concurrent use of alcohol and tobacco and its deleterious effects have been reported in the western literature. However, studies on the relationship between concurrent alcohol and tobacco use in India are limited. This study outlines the association between concurrent alcohol and tobacco use among a middle-aged and elderly population in a western Indian cohort after controlling for various sociodemographic factors. A total of 35 102 men, 45 years of age and above were interviewed for concurrent alcohol and tobacco use. The sample was part of an earlier cohort drawn from the general population. The data were analysed after controlling for age, education, religion and mother-tongue. Among alcohol users, 51.1% smoked tobacco and 35.6% used smokeless tobacco. The relative risk of alcohol use was highest among those smoking cigarettes or beedis and among those using mishri with betel quid and tobacco. The risk of alcohol use increased with the frequency of tobacco use. The risk also increased with higher amounts of alcohol consumption, but peaked at around 100-150 ml of absolute alcohol use. The study highlights the association between concurrent alcohol and tobacco use among the Indian population. This has important public health implications since concurrent use of these is synergistic for increased risk of oropharyngeal cancers.
Tinea capitis outbreak among paediatric refugee population, an evolving healthcare challenge.
Mashiah, Jacob; Kutz, Ana; Ben Ami, Ronen; Savion, Mihal; Goldberg, Ilan; Gan Or, Tamar; Zidan, Omri; Sprecher, Eli; Harel, Avikam
2016-09-01
Outbreaks of tinea capitis (TC) represent a major medical and economic burden. Population migrations have become a phenomenon of increasing relevance for medical conditions management. Given the recent massive arrival of immigrants, we sought to determine epidemiologic trends for TC among paediatric populations at the Tel Aviv Medical Center. We conducted a retrospective study of all TC cases diagnosed between 2010 and 2014 in a paediatric dermatology unit of a tertiary medical centre, serving as a referral centre for the paediatric refugee population from the great Tel Aviv area. Epidemiologic, clinical and treatment data including effectiveness and safety were reviewed. In all, 145 children met the inclusion criteria. Trend analyses showed increases in TC rates over the study period. Incidence rates were higher in boys than in girls. Children of African origin had the highest TC incidence rates as compared with other ethnic groups. Trichophyton violaceum and Microsporum audouinii were the predominant causative organisms. Treatment with griseofulvin was satisfactory in all cases. There was a significant increase in TC incidence rates in the Tel Aviv area over the study period. TV and MA were the predominant organisms. These trends may be a result of poor living conditions and crowded school premises. © 2016 Blackwell Verlag GmbH.
The bigger picture of FTO – the first GWAS-identified obesity gene
Loos, Ruth J.F.; Yeo, Giles S.H.
2014-01-01
In 2007, SNPs that cluster in the first intron of FTO showed highly significant association in the first two genome-wide association studies for obesity traits of which the minor allele increases body mass index (BMI) by 0.39 kg/m2 (or 1,130 g in body weight) and risk of obesity by 1.20 fold. Subsequent studies convincingly confirmed this association across populations of diverse ancestry and throughout the life course, with the largest effect seen in young adulthood. The effect of FTO SNPs on obesity traits in African and Asian ancestry populations is similar or somewhat smaller than in European ancestry populations, but the BMI-increasing allele is substantially less prevalent in non-European ancestry populations. FTO SNPs do not influence physical activity levels, yet, in physically active individuals, FTO’s effect on obesity susceptibility is attenuated by ~30%. Growing evidence from epidemiological and functional studies suggests that FTO confers an increased risk of obesity through subtle changes in food intake and preference. In addition, recent emerging data now points to a role for FTO in the sensing of nutrients and the regulation of translation and growth. In this review, we explore the genetic epidemiology of FTO and discuss how its complex biology might link to the regulation of body weight. PMID:24247219
NASA Astrophysics Data System (ADS)
Mahmud, A.; Hixson, M.; Kleeman, M. J.
2012-02-01
The effect of climate change on population-weighted concentrations of particulate matter (PM) during extreme events was studied using the Parallel Climate Model (PCM), the Weather Research and Forecasting (WRF) model and the UCD/CIT 3-D photochemical air quality model. A "business as usual" (B06.44) global emissions scenario was dynamically downscaled for the entire state of California between the years 2000-2006 and 2047-2053. Air quality simulations were carried out for 1008 days in each of the present-day and future climate conditions using year-2000 emissions. Population-weighted concentrations of PM0.1, PM2.5, and PM10 total mass, components species, and primary source contributions were calculated for California and three air basins: the Sacramento Valley air basin (SV), the San Joaquin Valley air basin (SJV) and the South Coast Air Basin (SoCAB). Results over annual-average periods were contrasted with extreme events. Climate change between 2000 vs. 2050 did not cause a statistically significant change in annual-average population-weighted PM2.5 mass concentrations within any major sub-region of California in the current study. Climate change did alter the annual-average composition of the airborne particles in the SoCAB, with notable reductions of elemental carbon (EC; -3%) and organic carbon (OC; -3%) due to increased annual-average wind speeds that diluted primary concentrations from gasoline combustion (-3%) and food cooking (-4%). In contrast, climate change caused significant increases in population-weighted PM2.5 mass concentrations in central California during extreme events. The maximum 24-h average PM2.5 concentration experienced by an average person during a ten-year period in the SJV increased by 21% due to enhanced production of secondary particulate matter (manifested as NH4NO3). In general, climate change caused increased stagnation during future extreme pollution events, leading to higher exposure to diesel engines particles (+32%) and wood combustion particles (+14%) when averaging across the population of the entire state. Enhanced stagnation also isolated populations from distant sources such as shipping (-61%) during extreme events. The combination of these factors altered the statewide population-averaged composition of particles during extreme events, with EC increasing by 23%, nitrate increasing by 58%, and sulfate decreasing by 46%.
NASA Astrophysics Data System (ADS)
Mahmud, A.; Hixson, M.; Kleeman, M. J.
2012-08-01
The effect of climate change on population-weighted concentrations of particulate matter (PM) during extreme pollution events was studied using the Parallel Climate Model (PCM), the Weather Research and Forecasting (WRF) model and the UCD/CIT 3-D photochemical air quality model. A "business as usual" (B06.44) global emissions scenario was dynamically downscaled for the entire state of California between the years 2000-2006 and 2047-2053. Air quality simulations were carried out for 1008 days in each of the present-day and future climate conditions using year-2000 emissions. Population-weighted concentrations of PM0.1, PM2.5, and PM10 total mass, components species, and primary source contributions were calculated for California and three air basins: the Sacramento Valley air basin (SV), the San Joaquin Valley air basin (SJV) and the South Coast Air Basin (SoCAB). Results over annual-average periods were contrasted with extreme events. The current study found that the change in annual-average population-weighted PM2.5 mass concentrations due to climate change between 2000 vs. 2050 within any major sub-region in California was not statistically significant. However, climate change did alter the annual-average composition of the airborne particles in the SoCAB, with notable reductions of elemental carbon (EC; -3%) and organic carbon (OC; -3%) due to increased annual-average wind speeds that diluted primary concentrations from gasoline combustion (-3%) and food cooking (-4%). In contrast, climate change caused significant increases in population-weighted PM2.5 mass concentrations in central California during extreme events. The maximum 24-h average PM2.5 concentration experienced by an average person during a ten-yr period in the SJV increased by 21% due to enhanced production of secondary particulate matter (manifested as NH4NO3). In general, climate change caused increased stagnation during future extreme pollution events, leading to higher exposure to diesel engines particles (+32%) and wood combustion particles (+14%) when averaging across the population of the entire state. Enhanced stagnation also isolated populations from distant sources such as shipping (-61%) during extreme events. The combination of these factors altered the statewide population-averaged composition of particles during extreme events, with EC increasing by 23 %, nitrate increasing by 58%, and sulfate decreasing by 46%.
Stephenson, Elizabeth A; Collins, Kathryn K; Dubin, Anne M; Epstein, Michael R; Hamilton, Robert M; Kertesz, Naomi J; Alexander, Mark E; Cecchin, Frank; Triedman, John K; Walsh, Edward P; Berul, Charles I
2002-10-01
Recent studies in adult populations have revealed seasonal variation in the frequency of acute cardiovascular events, including life-threatening arrhythmias, demonstrating increased events during winter and early spring. Trends in the time of day that arrhythmias occur also were noted. We sought to establish whether pediatric and young adult congenital heart disease implantable cardioverter defibrillator (ICD) recipients have circadian or seasonal variability in shock frequency, similar to adult populations. Data from ICD patients at six pediatric centers in North America were analyzed to assess the timing of life-threatening arrhythmias. The populations consisted of children and adults with congenital heart disease and ICDs placed for malignant arrhythmias. Data were considered in 46 patients who received appropriate therapy (total 139 episodes) for ventricular tachycardia or ventricular fibrillation. Multiple variables were analyzed, including time of day, day of week, and month of year. In contrast to previously studied adult patients, fewer events occurred in the early morning (7.5%), with the most therapies occurring between 6 P.M. and midnight (35%). An increased frequency of therapies was observed in the fall and winter (September-January), representing 60% of all appropriate shocks. Unlike adult populations, Mondays did not have an increased frequency of malignant arrhythmias. Pediatric and adult congenital heart disease populations have moderate seasonal and 24-hour variation in ICD event rate, with some distinctly different peaks than those seen in typical adult ICD populations. These findings suggest circadian variation in arrhythmia vulnerability that may differ from conventional occupational, physical, or emotional stressors. (J Cardiovasc Electrophysiol, Vol. 13, pp.
Jenkins, Tara L; Harrison, Donald L; Jacobs, Elgene W; Neas, Barbara R; Hagemann, Tracy M
2009-01-01
To evaluate the economic effect of a pharmacy benefit expansion on a population of Oklahoma Medicaid recipients and to determine whether recipients who routinely maximized their monthly prescription limit (cap) before the benefit expansion benefited more from the expansion than the remainder of the study population. Retrospective study. Oklahoma Medicaid claims data from January 1, 2003, to December 31, 2004. Data from 15,936 Oklahoma Medicaid recipients. Retrospective administrative analysis using the Oklahoma Health Care Authority pharmacy and medical claims databases. Total health care expenditures per recipient per year, total medical expenditures per recipient per year, and total pharmacy expenditures per recipient per year. Total health care expenditures increased 17% after the benefit expansion (P < 0.0001). Of this increase, 65% was attributed to pharmacy expenditures and 35% to medical expenditures. However, a subpopulation of recipients who routinely reached their prescription limit before the expansion had a statistically significant increase in total and pharmacy expenditures; a statistically significant increase in medical expenditures was not observed. Although total health care expenditures increased after a monthly pharmacy benefit in a Medicaid population was expanded, a subpopulation of recipients identified as high pharmacy users before the expansion did not have a statistically significant increase in medical expenditures, whereas those who were non-high users experienced a significant increase. Additionally, this subpopulation experienced a nonsignificant decrease in hospital expenditures. These results could suggest that this subpopulation was affected differently than the overall population by the expansion of the Medicaid pharmacy benefit.
Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh
2016-09-01
Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we show that long-term laboratory populations of D. melanogaster, descended from some of the populations used in the earlier studies, evolve essentially the same set of traits as the D. ananassae and D. n. nasuta crowding-adapted populations when subjected to a similar larval density at low absolute volumes of food. As in the case of D. ananassae and D. n. nasuta, and in stark contrast to earlier studies with D. melanogaster, these crowding-adapted populations of D. melanogaster did not evolve greater larval feeding rates as a correlate of increased competitive ability. The present results clearly suggest that the suite of phenotypes through which the evolution of greater competitive ability is achieved in fruitflies depends critically not just on larval density per unit volume of food, but also on the total amount of food available in the culture vials. We discuss these results in the context of an hypothesis about how larval density and the height of the food column in culture vials might interact to alter the fitness costs and benefits of increased larval feeding rates, thus resulting in different routes to the evolution of greater competitive ability, depending on the details of exactly how the larval crowding was implemented.
Effects of College Experiences on Male and Female Student Leadership Capacity in Taiwan
ERIC Educational Resources Information Center
Wu, Ching-Ling
2011-01-01
This study examined how college experiences affect student leadership capacity in the general college population, as well as in male versus female populations. The data were drawn from a longitudinal sample of students across 156 colleges in Taiwan. Results of this study indicated that student leadership capacity increased after college entry.…
NASA Technical Reports Server (NTRS)
Young, Ronald B.; Bridge, Kristin Y.; Vaughn, Jeffrey R.
1999-01-01
Skeletal muscle hypertrophy is promoted in vivo by administration of beta-drenergic receptor (bAR) agonists. Chicken skeletal muscle cells were treated with 1 (mu)M isoproterenol, a strong bAR agonist, between days 7 and 10 in culture. bAR population increased by approximately 40% during this treatment; however, the ability of the cells to synthesize cyclic AMP (cAMP) was diminished by two-fold. The quantity of myosin heavy chain (MHC) was not affected. To understand further the relationship between intracellular cAMP levels, bAR population, and muscle protein accumulation, intracellular cAMP levels were artificially elevated by treatment with 0-10 uM forskolin for up to three days. The basal concentration of CAMP in forskolin-treated cells increased up to 7-fold in a dose dependent manner. Increasing concentrations of forskolin also led to an increase in bAR population, with a maximum increase of approximately 40-60% at 10 uM forskolin. A maximum increase of 40-50% in the quantity of MHC was observed at 0.2 uM forskolin, but higher concentrations of forskolin reduced the quantity of MHC back to control levels. At 0.2 uM forskolin, intracellular levels of cAMP were higher by approximately 35%, and the (beta)AR population was higher by approximately 30%. Neither the number of muscle nuclei fused into myotubes nor the percentage of nuclei in myotubes were affected by forskolin at any of the concentrations studied.
Using population genetic tools to develop a control strategy for feral cats (Felis catus) in Hawai'i
Hansen, H.; Hess, S.C.; Cole, D.; Banko, P.C.
2007-01-01
Population genetics can provide information about the demographics and dynamics of invasive species that is beneficial for developing effective control strategies. We studied the population genetics of feral cats on Hawai'i Island by microsatellite analysis to evaluate genetic diversity and population structure, assess gene flow and connectivity among three populations, identify potential source populations, characterise population dynamics, and evaluate sex-biased dispersal. High genetic diversity, low structure, and high number of migrants per generation supported high gene flow that was not limited spatially. Migration rates revealed that most migration occurred out of West Mauna Kea. Effective population size estimates indicated increasing cat populations despite control efforts. Despite high gene flow, relatedness estimates declined significantly with increased geographic distance and Bayesian assignment tests revealed the presence of three population clusters. Genetic structure and relatedness estimates indicated male-biased dispersal, primarily from Mauna Kea, suggesting that this population should be targeted for control. However, recolonisation seems likely, given the great dispersal ability that may not be inhibited by barriers such as lava flows. Genetic monitoring will be necessary to assess the effectiveness of future control efforts. Management of other invasive species may benefit by employing these population genetic tools. ?? CSIRO 2007.
Is urbanisation scrambling the genetic structure of human populations? A case study
Ashrafian-Bonab, Maziar; Handley, Lori Lawson; Balloux, François
2007-01-01
Recent population expansion and increased migration linked to urbanisation are assumed to be eroding the genetic structure of human populations. We investigated change in population structure over three generations by analysing both demographic and mitochondrial DNA (mtDNA) data from a random sample of 2351 men from twenty-two Iranian populations. Potential changes in genetic diversity (θ) and genetic distance (FST) over the last three generations were analysed by assigning mtDNA sequences to populations based on the individual's place of birth or that of their mother or grandmother. Despite the fact that several areas included cities of over one million inhabitants, we detected no change in genetic diversity, and only a small decrease in population structure, except in the capital city (Tehran), which was characterised by massive immigration, increased θ and a large decrease in FST over time. Our results suggest that recent erosion of human population structure might not be as important as previously thought, except in some large conurbations, and this clearly has important implications for future sampling strategies. PMID:17106453
Dunn, Michael J; Jackson, Jennifer A; Adlard, Stacey; Lynnes, Amanda S; Briggs, Dirk R; Fox, Derren; Waluda, Claire M
2016-01-01
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual increase in gentoo breeding pairs.
Dunn, Michael J.; Jackson, Jennifer A.; Adlard, Stacey; Lynnes, Amanda S.; Briggs, Dirk R.; Fox, Derren; Waluda, Claire M.
2016-01-01
We report long-term changes in population size of three species of sympatrically breeding pygoscelid penguins: Adélie (Pygoscelis adeliae), chinstrap (Pygoscelis antarctica) and gentoo (Pygoscelis papua ellsworthii) over a 38 year period at Signy Island, South Orkney Islands, based on annual counts from selected colonies and decadal all-island systematic counts of occupied nests. Comparing total numbers of breeding pairs over the whole island from 1978/79 to 2015/16 revealed varying fortunes: gentoo penguin pairs increased by 255%, (3.5% per annum), chinstrap penguins declined by 68% (-3.6% per annum) and Adélie penguins declined by 42% (-1.5% per annum). The chinstrap population has declined steadily over the last four decades. In contrast, Adélie and gentoo penguins have experienced phases of population increase and decline. Annual surveys of selected chinstrap and Adélie colonies produced similar trends from those revealed by island-wide surveys, allowing total island population trends to be inferred relatively well. However, while the annual colony counts of chinstrap and Adélie penguins showed a trend consistent in direction with the results from all-island surveys, the magnitude of estimated population change was markedly different between colony wide and all island counts. Annual population patterns suggest that pair numbers in the study areas partly reflect immigration and emigration of nesting birds between different parts of the island. Breeding success for all three species remained broadly stable over time in the annually monitored colonies. Breeding success rates in gentoo and chinstrap penguins were strongly correlated, despite the differing trends in population size. This study shows the importance of effective, standardised monitoring to accurately determine long-term population trajectories. Our results indicate significant declines in the Adélie and chinstrap penguin populations at Signy Island over the last five decades, and a gradual increase in gentoo breeding pairs. PMID:27783668
Pearce, J.M.
2006-01-01
Insertions and deletions (indels) result in sequences of various lengths when homologous gene regions are compared among individuals or species. Although indels are typically phylogenetically informative, occurrence and incorporation of these characters as gaps in intraspecific population genetic data sets are rarely discussed. Moreover, the impact of gaps on estimates of fixation indices, such as FST, has not been reviewed. Here, I summarize the occurrence and population genetic signal of indels among 60 published studies that involved alignments of multiple sequences from the mitochondrial DNA (mtDNA) control region of vertebrate taxa. Among 30 studies observing indels, an average of 12% of both variable and parsimony-informative sites were composed of these sites. There was no consistent trend between levels of population differentiation and the number of gap characters in a data block. Across all studies, the average influence on estimates of ??ST was small, explaining only an additional 1.8% of among population variance (range 0.0-8.0%). Studies most likely to observe an increase in ??ST with the inclusion of gap characters were those with < 20 variable sites, but a near equal number of studies with few variable sites did not show an increase. In contrast to studies at interspecific levels, the influence of indels for intraspecific population genetic analyses of control region DNA appears small, dependent upon total number of variable sites in the data block, and related to species-specific characteristics and the spatial distribution of mtDNA lineages that contain indels. ?? 2006 Blackwell Publishing Ltd.
Nuclear DNA analyses in genetic studies of populations: practice, problems and prospects.
Zhang, De-Xing; Hewitt, Godfrey M
2003-03-01
Population-genetic studies have been remarkably productive and successful in the last decade following the invention of PCR technology and the introduction of mitochondrial and microsatellite DNA markers. While mitochondrial DNA has proven powerful for genealogical and evolutionary studies of animal populations, and microsatellite sequences are the most revealing DNA markers available so far for inferring population structure and dynamics, they both have important and unavoidable limitations. To obtain a fuller picture of the history and evolutionary potential of populations, genealogical data from nuclear loci are essential, and the inclusion of other nuclear markers, i.e. single copy nuclear polymorphic (scnp) sequences, is clearly needed. Four major uncertainties for nuclear DNA analyses of populations have been facing us, i.e. the availability of scnp markers for carrying out such analysis, technical laboratory hurdles for resolving haplotypes, difficulty in data analysis because of recombination, low divergence levels and intraspecific multifurcation evolution, and the utility of scnp markers for addressing population-genetic questions. In this review, we discuss the availability of highly polymorphic single copy DNA in the nuclear genome, describe patterns and rate of evolution of nuclear sequences, summarize past empirical and theoretical efforts to recover and analyse data from scnp markers, and examine the difficulties, challenges and opportunities faced in such studies. We show that although challenges still exist, the above-mentioned obstacles are now being removed. Recent advances in technology and increases in statistical power provide the prospect of nuclear DNA analyses becoming routine practice, allowing allele-discriminating characterization of scnp loci and microsatellite loci. This certainly will increase our ability to address more complex questions, and thereby the sophistication of genetic analyses of populations.
van Strien, Maarten J; Keller, Daniela; Holderegger, Rolf; Ghazoul, Jaboury; Kienast, Felix; Bolliger, Janine
2014-03-01
For conservation managers, it is important to know whether landscape changes lead to increasing or decreasing gene flow. Although the discipline of landscape genetics assesses the influence of landscape elements on gene flow, no studies have yet used landscape-genetic models to predict gene flow resulting from landscape change. A species that has already been severely affected by landscape change is the large marsh grasshopper (Stethophyma grossum), which inhabits moist areas in fragmented agricultural landscapes in Switzerland. From transects drawn between all population pairs within maximum dispersal distance (< 3 km), we calculated several measures of landscape composition as well as some measures of habitat configuration. Additionally, a complete sampling of all populations in our study area allowed incorporating measures of population topology. These measures together with the landscape metrics formed the predictor variables in linear models with gene flow as response variable (F(ST) and mean pairwise assignment probability). With a modified leave-one-out cross-validation approach, we selected the model with the highest predictive accuracy. With this model, we predicted gene flow under several landscape-change scenarios, which simulated construction, rezoning or restoration projects, and the establishment of a new population. For some landscape-change scenarios, significant increase or decrease in gene flow was predicted, while for others little change was forecast. Furthermore, we found that the measures of population topology strongly increase model fit in landscape genetic analysis. This study demonstrates the use of predictive landscape-genetic models in conservation and landscape planning.
García-Comas, Luis; Ordobás, María; Sanz, Juan Carlos; Ramos, Belén; Arce, Araceli; Barranco, Dolores
2016-01-01
Seroprevalence surveys enable the level of endemicity of hepatitis A (HAV) to be assessed. The aim of this study was to estimate the seroprevalence (SP) antibody against HAV by age group, and compare it with those obtained in previous surveys. Observational cross-sectional study. The target population consists of residents from 2 to 60 years old in the Community of Madrid. Two-stage cluster sampling was performed with stratification of first stage units. After signing the informed consent, a serum sample was extracted from each participant and sociodemographic data were collected by a questionnaire. SP antibodies to hepatitis A is 46.8% (95% CI 44.6 to 49.0). The SP increases with age. It is higher in the population from more endemic countries and people with less education and lower social class. In relation to the previous survey, SP increased in the population under 30 years old, and a decline after that age is observed. If only the autochthonous population and from countries with very low endemicity is observed, the increase is statistically significant in the 2-5 years age group. Our region has a very low level of endemicity thus, following the recommendations of WHO, vaccination should be targeted at specific risk groups. Copyright © 2015 Elsevier España, S.L.U. y Sociedad Española de Enfermedades Infecciosas y Microbiología Clínica. All rights reserved.
Olsen, Siri L; Töpper, Joachim P; Skarpaas, Olav; Vandvik, Vigdis; Klanderud, Kari
2016-05-01
Biotic interactions are often ignored in assessments of climate change impacts. However, climate-related changes in species interactions, often mediated through increased dominance of certain species or functional groups, may have important implications for how species respond to climate warming and altered precipitation patterns. We examined how a dominant plant functional group affected the population dynamics of four co-occurring forb species by experimentally removing graminoids in seminatural grasslands. Specifically, we explored how the interaction between dominants and subordinates varied with climate by replicating the removal experiment across a climate grid consisting of 12 field sites spanning broad-scale temperature and precipitation gradients in southern Norway. Biotic interactions affected population growth rates of all study species, and the net outcome of interactions between dominants and subordinates switched from facilitation to competition with increasing temperature along the temperature gradient. The impacts of competitive interactions on subordinates in the warmer sites could primarily be attributed to reduced plant survival. Whereas the response to dominant removal varied with temperature, there was no overall effect of precipitation on the balance between competition and facilitation. Our findings suggest that global warming may increase the relative importance of competitive interactions in seminatural grasslands across a wide range of precipitation levels, thereby favouring highly competitive dominant species over subordinate species. As a result, seminatural grasslands may become increasingly dependent on disturbance (i.e. traditional management such as grazing and mowing) to maintain viable populations of subordinate species and thereby biodiversity under future climates. Our study highlights the importance of population-level studies replicated under different climatic conditions for understanding the underlying mechanisms of climate change impacts on plants. © 2016 John Wiley & Sons Ltd.
Luo, X N; Yang, M; Liang, X F; Jin, K; Lv, L Y; Tian, C X; Yuan, Y C; Sun, J
2015-09-25
In this study, 12 polymorphic microsatellites were inves-tigated to determine the genetic diversity and structure of 5 consecu-tive selected populations of golden mandarin fish (Siniperca scherzeri Steindachner). The total numbers of alleles, average heterozyosity, and average polymorphism information content showed that the genetic diversity of these breeding populations was decreasing. Additionally, pairwise fixation index FST values among populations and Da values in-creased from F1 generation to subsequent generations (FST values from 0.0221-0.1408; Da values from 0.0608-0.1951). Analysis of molecular variance indicated that most genetic variations arise from individuals within populations (about 92.05%), while variation among populations accounted for only 7.95%. The allele frequency of the loci SC75-220 and SC101-222 bp changed regularly in the 5 breeding generations. Their frequencies were gradually increased and showed an enrichment trend, indicating that there may be genetic correlations between these 2 loci and breeding traits. Our study indicated that microsatellite markers are effective for assessing the genetic variability in the golden mandarin fish breeding program.
McCaffery, Rebecca M.; Reisor, Rita; Irvine, Kathryn M.; Brunson, Jessi
2014-01-01
Energy development, in combination with other environmental stressors, poses a persistent threat to rare species endemic to the energy-producing regions of the Western United States. Demographic analyses of monitored populations can provide key information on the natural dynamics of threatened plant and animal populations, and how they might be affected by ongoing and future development. In the Uinta Basin in Utah and Colorado, Graham’s beardtongue (Penstemon grahamii) and White River beardtongue (Penstemon scariosus var. albifluvis) are two rare endemic wildflowers that persist on oil shale habitats heavily impacted by current energy exploration and development, and slated for expanded traditional drilling and oil shale development. We described demographic characteristics and population viability for two populations of each species that have been monitored since 2004. First, we measured population size, survival rates, transitions between life stages, and recruitment using individually marked plants at the four study areas. Then, we used matrix population models to determine stochastic population growth rates (λ) and the probability that each population would persist 50 years into the future, given current conditions. The two P. grahamii study plots had small populations averaging 70 adult plants, and relatively constant and high survival in both vegetative and flowering plants. The two P. scariosus var. albifluvis study plots had populations that averaged 120 adult plants, with high and stable survival in flowering plants and variable survival in vegetative plants. Recruitment of new seedlings into all populations was low and variable, with most recruitment occurring in one or two years. Both P. grahamii populations had λ near 1.0 (stable). One P. scariosus var. albifluvis population appeared to be declining (λ=0.97), while the other was increasing (λ=1.16). Our analyses reveal populations that appear relatively stable, but that are susceptible to declines now and into the future. Increases in environmental variability, deterministic changes in habitat conditions or stressors, or a single catastrophic event could all have immediately deleterious impacts on the long-term growth trajectory of these populations.
Potential negative ecological effects of corridors.
Haddad, Nick M; Brudvig, Lars A; Damschen, Ellen I; Evans, Daniel M; Johnson, Brenda L; Levey, Douglas J; Orrock, John L; Resasco, Julian; Sullivan, Lauren L; Tewksbury, Josh J; Wagner, Stephanie A; Weldon, Aimee J
2014-10-01
Despite many studies showing that landscape corridors increase dispersal and species richness for disparate taxa, concerns persist that corridors can have unintended negative effects. In particular, some of the same mechanisms that underlie positive effects of corridors on species of conservation interest may also increase the spread and impact of antagonistic species (e.g., predators and pathogens), foster negative effects of edges, increase invasion by exotic species, increase the spread of unwanted disturbances such as fire, or increase population synchrony and thus reduce persistence. We conducted a literature review and meta-analysis to evaluate the prevalence of each of these negative effects. We found no evidence that corridors increase unwanted disturbance or non-native species invasion; however, these have not been well-studied concerns (1 and 6 studies, respectively). Other effects of corridors were more often studied and yielded inconsistent results; mean effect sizes were indistinguishable from zero. The effect of edges on abundances of target species was as likely to be positive as negative. Corridors were as likely to have no effect on antagonists or population synchrony as they were to increase those negative effects. We found 3 deficiencies in the literature. First, despite studies on how corridors affect predators, there are few studies of related consequences for prey population size and persistence. Second, properly designed studies of negative corridor effects are needed in natural corridors at scales larger than those achievable in experimental systems. Third, studies are needed to test more targeted hypotheses about when corridor-mediated effects on invasive species or disturbance may be negative for species of management concern. Overall, we found no overarching support for concerns that construction and maintenance of habitat corridors may result in unintended negative consequences. Negative edge effects may be mitigated by widening corridors or softening edges between corridors and the matrix. Other negative effects are relatively small and manageable compared with the large positive effects of facilitating dispersal and increasing diversity of native species. © 2014 Society for Conservation Biology.
Nationwide Trend of Sepsis: A Comparison Among Octogenarians, Elderly, and Young Adults.
Lee, Si-Huei; Hsu, Tzu-Chun; Lee, Meng-Tse Gabriel; Chao, Christin Chihh-Ting; Lee, Wan-Chien; Lai, Chi-Cheng; Lee, Chien-Chang
2018-06-01
We aimed to compare the sepsis incidence, mortality rates, and primary sites of infection among adult, elderly, and octogenarian patients with sepsis. Population-based cohort study. The entire health insurance claims data of Taiwan, which enrolled 99.8% of the 23 million Taiwanese population. Sepsis patients were identified by International Classification of Diseases, 9th Edition, Clinical Modification codes for both infection and organ dysfunction from January 1, 2002, to December 31, 2012. Patients were categorized into three age groups: 1) adults (18-64 yr); 2) elderly (65-84 yr); and 3) oldest old (≥ 85 yr). The 30-day all-cause mortality was verified by a linked national death certificate database. None. From 2002 to 2012, we identified 1,259,578 patients with sepsis, of which 417,328 (33.1%) were adults, 652,618 (51.8%) were elderly, and 189,632 (15.1%) were oldest old. We determined that the incidence of sepsis in the oldest old was 9,414 cases per 100,000 population on 2012, which was 31-fold greater than the adult incidence (303 cases per 100,000 population) and three-fold greater than the elderly incidence (2,908 cases per 100,000 population). Despite the increasing trend in incidence, the mortality decreased by 34% for adults, 24% for elderly, and 22% for oldest old. However, systemic fungal infection was disproportionately increased in oldest old patients (1.76% annual increase) and the elderly patients (1.00% annual increase). The incidence of sepsis is disproportionately increased in elderly and oldest old patients. Despite the increasing trend in incidence, the mortality rate in geriatric patients with sepsis has decreased. However, the increased incidence of fungal infections in the geriatric population warrants further attention.
[Prevalence of metabolic syndrome and cardiovascular risk in an urban area of Murcia].
Fernández-Ruiz, Virginia E; Paniagua-Urbano, José A; Solé-Agustí, María; Ruiz-Sánchez, Alfonso; Gómez-Marín, José
2014-11-01
It is extensive scientific literature that has defined the metabolic syndrome as a precursor of cardiovascular disease. To estimate the prevalence of metabolic syndrome and cardiovascular risk in the population of a basic health area of Murcia. Cross sectional study population of the district health "The Esparragal" random sample of the population between 18 and 86 years living in the area. Personal history were collected and held a relevant clinical, anthropometric data and analytics for the estimation of Metabolic Syndrome and Cardiovascular Risk following criteria dictated by the current literature, adjusted for sex and age. The mean age of the study population was 59.34 ± 14.79 years, with 52.5% males. The overall prevalence of metabolic syndrome criteria World Health Organization is presented 36.8%, a figure increased under International Diabetes Ferderation recommendations to 58.2% and according to National Cholesterol Education Program, an estimated 53.5%. The presentation of this syndrome is slightly higher in men (54.1 versus 52.8 %), and in parallel with increasing age (p < 0.001). The prevalence of people at high risk of cardiovascular disease is 32.1 % (95 % CI 29.4 to 34.8), with 45.2 % (95% CI 41.2 to 49.2) in men and 17.6% (95% CI 14.4 to 20.8) in women. The prevalence of metabolic syndrome and cardiovascular risk in the study population is the highest found in Spain in population studies, indicating an invaluable population on which preventive measures. Copyright AULA MEDICA EDICIONES 2014. Published by AULA MEDICA. All rights reserved.
Subasinghe, Asvini K; Arabshahi, Simin; Busingye, Doreen; Evans, Roger G; Walker, Karen Z; Riddell, Michaela A; Thrift, Amanda G
2016-01-01
The prevalence of hypertension, the greatest contributor to mortality globally, is increasing in low-and-middle income countries (LMICs). In urban regions of LMICs, excessive salt intake is associated with increased risk of hypertension. We aimed to determine whether this is the case in rural regions as well. We performed a meta-analysis of studies in rural and urban areas of LMICs in which the association of salt and hypertension were assessed using multivariable models. We identified 18 studies with a total of 134,916 participants. The prevalence of high salt intake ranged from 21.3% to 89.5% in rural and urban populations. When salt was analysed as a continuous variable, a greater impact of salt on hypertension was found in urban (n=4) (pooled effect size (ES) 1.42, 95% CI 1.19, 1.69) than in rural populations (n=4) (pooled ES 1.07, 95% CI 1.04, 1.10, p for difference <0.001). In studies where salt was analysed continuously, a greater impact of salt on hypertension was observed in lean rural populations (BMI <23 kg/m2) than in non-lean rural populations (BMI >=23 kg/m2, p for difference <0.001). The prevalence of high salt intake is similar in rural and urban regions. Excessive salt intake has a greater impact on the prevalence of hypertension in urban than rural regions. BMI appears to modify the relationship between salt and hypertension in rural populations.
Slowly switching between environments facilitates reverse evolution in small populations.
Tan, Longzhi; Gore, Jeff
2012-10-01
Natural populations must constantly adapt to ever-changing environmental conditions. A particularly interesting question is whether such adaptations can be reversed by returning the population to an ancestral environment. Such evolutionary reversals have been observed in both natural and laboratory populations. However, the factors that determine the reversibility of evolution are still under debate. The time scales of environmental change vary over a wide range, but little is known about how the rate of environmental change influences the reversibility of evolution. Here, we demonstrate computationally that slowly switching between environments increases the reversibility of evolution for small populations that are subject to only modest clonal interference. For small populations, slow switching reduces the mean number of mutations acquired in a new environment and also increases the probability of reverse evolution at each of these "genetic distances." As the population size increases, slow switching no longer reduces the genetic distance, thus decreasing the evolutionary reversibility. We confirm this effect using both a phenomenological model of clonal interference and also a Wright-Fisher stochastic simulation that incorporates genetic diversity. Our results suggest that the rate of environmental change is a key determinant of the reversibility of evolution, and provides testable hypotheses for experimental evolution. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.
Bil, Janneke P; Prins, Maria; Stolte, Ineke G; Dijkshoorn, Henriëtte; Heijman, Titia; Snijder, Marieke B; Davidovich, Udi; Zuure, Freke R
2017-01-01
Objectives There are limited data on the usage of commercially bought self-tests for HIV and other sexually transmitted infections (STIs). Therefore, we studied HIV/STI self-test usage and its determinants among the general population and sexual risk groups between 2007 and 2015 in Amsterdam, the Netherlands. Setting Data were collected in four different studies among the general population (S1–2) and sexual risk groups (S3–4). Participants S1–Amsterdam residents participating in representative population-based surveys (2008 and 2012; n=6044) drawn from the municipality register; S2–Participants of a population-based study stratified by ethnicity drawn from the municipality register of Amsterdam (2011–2015; n=17 603); S3–Men having sex with men (MSM) participating in an HIV observational cohort study (2008 and 2013; n=597) and S4–STI clinic clients participating in a cross-sectional survey (2007–2012; n=5655). Primary and secondary outcome measures Prevalence of HIV/STI self-test usage and its determinants. Results The prevalence of HIV/STI self-test usage in the preceding 6–12 months varied between 1% and 2% across studies. Chlamydia self-tests were most commonly used, except among MSM in S3. Chlamydia and syphilis self-test usage increased over time among the representative sample of Amsterdam residents (S1) and chlamydia self-test usage increased over time among STI clinic clients (S4). Self-test usage was associated with African Surinamese or Ghanaian ethnic origin (S2), being woman or MSM (S1 and 4) and having had a higher number of sexual partners (S1–2). Among those in the general population who tested for HIV/STI in the preceding 12 months, 5–9% used a self-test. Conclusions Despite low HIV/STI self-test usage, we observed increases over time in chlamydia and syphilis self-test usage. Furthermore, self-test usage was higher among high-risk individuals in the general population. It is important to continue monitoring self-test usage and informing the public about the unknown quality of available self-tests in the Netherlands and about the pros and cons of self-testing. PMID:28939577
Dodds, Naomi; Emerson, Philip; Phillips, Stephanie; Green, David R; Jansen, Jan O
2017-03-01
Trauma systems in remote and rural regions often rely on helicopter emergency medical services to facilitate access to definitive care. The siting of such resources is key, but often relies on simplistic modeling of coverage, using circular isochrones. Scotland is in the process of implementing a national trauma network, and there have been calls for an expansion of aeromedical retrieval capacity. The aim of this study was to analyze population and area coverage of the current retrieval service configuration, with three aircraft, and a configuration with an additional helicopter, in the North East of Scotland, using a novel methodology. Both overall coverage and coverage by physician-staffed aircraft, with enhanced clinical capability, were analyzed. This was a geographical analysis based on calculation of elliptical isochrones, which consider the "open-jaw" configuration of many retrieval flights. Helicopters are not always based at hospitals. We modeled coverage based on different outbound and inbound flights. Areally referenced population data were obtained from the Scottish Government. The current helicopter network configuration provides 94.2% population coverage and 59.0% area coverage. The addition of a fourth helicopter would marginally increase population coverage to 94.4% and area coverage to 59.1%. However, when considering only physician-manned aircraft, the current configuration provides only 71.7% population coverage and 29.4% area coverage, which would be increased to 91.1% and 51.2%, respectively, with a second aircraft. Scotland's current helicopter network configuration provides good population coverage for retrievals to major trauma centers, which would only be increased minimally by the addition of a fourth aircraft in the North East. The coverage provided by the single physician-staffed aircraft is more limited, however, and would be increased considerably by a second physician-staffed aircraft in the North East. Elliptical isochrones provide a useful means of modeling "open-jaw" retrieval missions and provide a more realistic estimate of coverage. Epidemiological study, level IV; therapeutic study, level IV.
Santidrián Tomillo, Pilar; Genovart, Meritxell; Paladino, Frank V; Spotila, James R; Oro, Daniel
2015-08-01
Temperature-dependent sex determination (TSD) is the predominant form of environmental sex determination (ESD) in reptiles, but the adaptive significance of TSD in this group remains unclear. Additionally, the viability of species with TSD may be compromised as climate gets warmer. We simulated population responses in a turtle with TSD to increasing nest temperatures and compared the results to those of a virtual population with genotypic sex determination (GSD) and fixed sex ratios. Then, we assessed the effectiveness of TSD as a mechanism to maintain populations under climate change scenarios. TSD populations were more resilient to increased nest temperatures and mitigated the negative effects of high temperatures by increasing production of female offspring and therefore, future fecundity. That buffered the negative effect of temperature on the population growth. TSD provides an evolutionary advantage to sea turtles. However, this mechanism was only effective over a range of temperatures and will become inefficient as temperatures rise to levels projected by current climate change models. Projected global warming threatens survival of sea turtles, and the IPCC high gas concentration scenario may result in extirpation of the studied population in 50 years. © 2015 John Wiley & Sons Ltd.
[TRENDS IN HEALTH OF THE POPULATION IN THE AREA OF THE TENGIZ FIELD].
Kenessaryiev, U I; Yerzhanova, A E; Kenessary, D U; Amrin, M K; Dosmukhametov, A T; Baimukhamedov, A A
2015-01-01
At the present the Caspian oil and gas field became extremely important for the economy of Kazakhstan and it has entered a qualitatively new stage of its development. In connection with the intensive development of these fields the attention of both scientists and health practitioners is attracted by problems of populations' health. In the article there are presented data of a study of the quality of main objects of environment, health condition, demographic indices of and morbidity rate of the population of the Zhylyoi district of the Atyrau region. The population resides in the region of influence of the Tengiz oil and gas field. The level of mortality in Zhylyoi for the periodfrom 2006 to 2013 was establishe to decline, as birth rate rather increased. Indices of the population's structure retain the tendency to the progressive type, possibly in relation with urbanization and industrial migration of population, that increased in last years. The district mortality rates are below national, regional and urban values. Natural population growth in Zhylyoi has increased by 27.6%. The analysis of primary morbidity of the population of the Zhylyoi district in dynamics from 2006 to 2013 shows a some decrease. In the structure of the morbidity there was noted a decrease in the proportion of diseases of the skin and subcutaneous tissue, respiratory diseases, digestive organs. However, the proportion of blood diseases, diseases of the hematopoietic system and blood flow has increased. Alongside this in the region there is clearly discernible the scarcity of doctors, qualified nurses and beds.
Dalager-Pedersen, Michael; Søgaard, Mette; Schønheyder, Henrik Carl; Nielsen, Henrik; Thomsen, Reimar Wernich
2014-04-01
Infections may trigger acute cardiovascular events, but the risk after community-acquired bacteremia is unknown. We assessed the risk for acute myocardial infarction and ischemic stroke within 1 year of community-acquired bacteremia. This population-based cohort study was conducted in Northern Denmark. We included 4389 hospitalized medical patients with positive blood cultures obtained on the day of admission. Patients hospitalized with bacteremia were matched with up to 10 general population controls and up to 5 acutely admitted nonbacteremic controls, matched on age, sex, and calendar time. All incident events of myocardial infarction and stroke during the following 365 days were ascertained from population-based healthcare databases. Multivariable regression analyses were used to assess relative risks with 95% confidence intervals (CIs) for myocardial infarction and stroke among bacteremia patients and their controls. The risk for myocardial infarction or stroke was greatly increased within 30 days of community-acquired bacteremia: 3.6% versus 0.2% among population controls (adjusted relative risk, 20.86; 95% CI, 15.38-28.29) and 1.7% among hospitalized controls (adjusted relative risk, 2.18; 95% CI, 1.80-2.65). The risks for myocardial infarction or stroke remained modestly increased from 31 to 180 days after bacteremia in comparison with population controls (adjusted hazard ratio, 1.64; 95% CI, 1.18-2.27), but not versus hospitalized controls (adjusted hazard ratio, 0.95; 95% CI, 0.69-1.32). No differences in cardiovascular risk were seen after >6 months. Increased 30-day risks were consistently found for a variety of etiologic agents and infectious foci. Community-acquired bacteremia is associated with increased short-term risk of myocardial infarction and stroke.
Elbaz, Avi; Mor, Amit; Segal, Ganit; Aloni, Yoav; Teo, Yee Hong; Teo, Yee Sze; Das-De, Shamal; Yeo, Seng Jin
2014-01-02
Previous studies have shown the effect of a unique therapy with a non-invasive biomechanical foot-worn device (AposTherapy) on Caucasian western population suffering from knee osteoarthritis. The purpose of the current study was to evaluate the effect of this therapy on the level of symptoms and gait patterns in a multi-ethnic Singaporean population suffering from knee osteoarthritis. Fifty-eight patients with bilateral medial compartment knee osteoarthritis participated in the study. All patients underwent a computerized gait test and completed two self-assessment questionnaires (WOMAC and SF-36). The biomechanical device was calibrated to each patient, and therapy commenced. Changes in gait patterns and self-assessment questionnaires were reassessed after 3 and 6 months of therapy. A significant improvement was seen in all of the gait parameters following 6 months of therapy. Specifically, gait velocity increased by 15.9%, step length increased by 10.3%, stance phase decreased by 5.9% and single limb support phase increased by 2.7%. In addition, pain, stiffness and functional limitation significantly decreased by 68.3%, 66.7% and 75.6%, respectively. SF-36 physical score and mental score also increased significantly following 6 months of therapy (46.1% and 22.4%, respectively) (P < 0.05 for all parameters). Singaporean population with medial compartment knee osteoarthritis demonstrated improved gait patterns, reported alleviation in symptoms and improved function and quality of life following 6 months of therapy with a unique biomechanical device. Registration number NCT01562652.
Kawasaki, Ryo; Wang, Jie Jin; Rochtchina, Elena; Taylor, Bronwen; Wong, Tien Yin; Tominaga, Makoto; Kato, Takeo; Daimon, Makoto; Oizumi, Toshihide; Kawata, Sumio; Kayama, Takamasa; Yamashita, Hidetoshi; Mitchell, Paul
2006-08-01
To describe the prevalence of retinal vascular signs and their association with cardiovascular risk factors in a Japanese population. Population-based cross-sectional study. Adult persons aged 35 years or older from Funagata, Yamagata Prefecture, Japan (n = 1481). The Funagata Study is a Japanese population-based study of persons aged 35 years or older, and included 1961 nondiabetic participants (53.3% of 3676 eligible subjects). A nonmydriatic retinal photograph was taken of 1 eye to assess retinal microvascular signs. Retinal arteriolar wall signs (focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar wall reflex) and retinopathy were assessed in 1481 participants without diabetes (40.3% of eligible persons) using a standardized protocol. Using a computer-assisted method, retinal vessel diameters were measured in 921 participants with gradable retinal image (25.1% of eligible persons). Prevalence of retinal microvascular signs and their association with cardiovascular risk factors. Moderate or severe focal arteriolar narrowing, arteriovenous nicking, enhanced arteriolar wall reflex, and retinopathy were found in 8.3%, 15.2%, 18.7%, and 9.0%, respectively, of the study population. Mean (+/-standard error) values for retinal arteriolar diameter were 178.6+/-21.0 mum, and mean values (+/-standard error) for venular diameter were 214.9+/-20.6 mum. Older persons were more likely to have retinal arteriolar wall signs, retinopathy, and narrower retinal vessel diameters. After adjusting for multiple factors, each 10-mmHg increase in mean arterial blood pressure was associated with a 20% to 40% increased likelihood of retinal arteriolar signs and a 2.8-mum reduction in arteriolar diameter. Retinopathy was associated with higher body mass index and both impaired glucose tolerance and impaired fasting glucose. In nondiabetic Japanese adults, retinal arteriolar wall signs were associated with older age and increased blood pressure, whereas retinopathy was associated with older age, higher body mass index, impaired glucose tolerance, and impaired fasting glucose. These findings are comparable with data from white populations.
Transition to an aging Japan: public pension, savings, and capital taxation.
Kato, R
1998-09-01
This study examined options for compensating for the shortages of money for public pensions due to population aging in Japan: increases in pension contributions, consumption pension taxes, interest income pension taxes, and inheritance pension taxes. The analysis relied on simulation in an expanded life cycle growth model. Data were obtained from 1992 estimations of population by the Institute of Population Problems of the Ministry of Health and Welfare. This study is unique in its use of real population data for the simulations and in its use of transition states. The analysis begins with a description of the altered Overlapping Generations Model by Auerback and Kotlikoff (1983). The model accounts for the inaccuracy of lifetime and liquidity constraints and ordinary budget constraints and reproduces the consumption-savings profiles of older people and incorporates wage income taxation and other forms of taxation. Income includes wage and interest income. The analysis includes a description of the method of simulation, assumptions, and evaluation of the effects of population aging. It is assumed that narrower government sector spending on general expenditures per worker will increase by 1% every year. It is concluded that national saving rates will probably decrease due to population aging. The lowest levels of capital stock and savings will result from higher pension contributions. The highest level of capital stock will result from higher consumption pension taxes during 1990-2015. Preferred policies should focus on increasing interest income rates.
Keever, Allison; McGowan, Conor P.; Ditchkoff, Stephen S.; Acker, S.A.; Grand, James B.; Newbolt, Chad H.
2017-01-01
Automated cameras have become increasingly common for monitoring wildlife populations and estimating abundance. Most analytical methods, however, fail to account for incomplete and variable detection probabilities, which biases abundance estimates. Methods which do account for detection have not been thoroughly tested, and those that have been tested were compared to other methods of abundance estimation. The goal of this study was to evaluate the accuracy and effectiveness of the N-mixture method, which explicitly incorporates detection probability, to monitor white-tailed deer (Odocoileus virginianus) by using camera surveys and a known, marked population to collect data and estimate abundance. Motion-triggered camera surveys were conducted at Auburn University’s deer research facility in 2010. Abundance estimates were generated using N-mixture models and compared to the known number of marked deer in the population. We compared abundance estimates generated from a decreasing number of survey days used in analysis and by time periods (DAY, NIGHT, SUNRISE, SUNSET, CREPUSCULAR, ALL TIMES). Accurate abundance estimates were generated using 24 h of data and nighttime only data. Accuracy of abundance estimates increased with increasing number of survey days until day 5, and there was no improvement with additional data. This suggests that, for our system, 5-day camera surveys conducted at night were adequate for abundance estimation and population monitoring. Further, our study demonstrates that camera surveys and N-mixture models may be a highly effective method for estimation and monitoring of ungulate populations.
Trivelpiece, Wayne Z.; Hinke, Jefferson T.; Miller, Aileen K.; Reiss, Christian S.; Trivelpiece, Susan G.
2011-01-01
The West Antarctic Peninsula (WAP) and adjacent Scotia Sea support abundant wildlife populations, many of which were nearly extirpated by humans. This region is also among the fastest-warming areas on the planet, with 5–6 °C increases in mean winter air temperatures and associated decreases in winter sea-ice cover. These biological and physical perturbations have affected the ecosystem profoundly. One hypothesis guiding ecological interpretations of changes in top predator populations in this region, the “sea-ice hypothesis,” proposes that reductions in winter sea ice have led directly to declines in “ice-loving” species by decreasing their winter habitat, while populations of “ice-avoiding” species have increased. However, 30 y of field studies and recent surveys of penguins throughout the WAP and Scotia Sea demonstrate this mechanism is not controlling penguin populations; populations of both ice-loving Adélie and ice-avoiding chinstrap penguins have declined significantly. We argue in favor of an alternative, more robust hypothesis that attributes both increases and decreases in penguin populations to changes in the abundance of their main prey, Antarctic krill. Unlike many other predators in this region, Adélie and chinstrap penguins were never directly harvested by man; thus, their population trajectories track the impacts of biological and environmental changes in this ecosystem. Linking trends in penguin abundance with trends in krill biomass explains why populations of Adélie and chinstrap penguins increased after competitors (fur seals, baleen whales, and some fishes) were nearly extirpated in the 19th to mid-20th centuries and currently are decreasing in response to climate change. PMID:21482793
Abdominal obesity, ethnicity and gastro‐oesophageal reflux symptoms
Corley, Douglas A; Kubo, Ai; Zhao, Wei
2007-01-01
Objective To evaluate the associations between abdominal obesity and gastro‐oesophageal reflux disease (GORD), and their interactions with ethnicity and gender. Design A cross‐sectional study. Participants completed detailed symptom questionnaires and underwent a standardised examination, including anthropometric measurements. Setting A large integrated healthcare system. Patients 80 110 members of the Kaiser Permanente multiphasic health check‐up cohort. Main outcome measures Gastro‐oesophageal reflux‐type symptoms. Results Recent reflux‐type symptoms were present in 11% of the population. The multivariate OR for symptoms with an abdominal diameter (adjusted for body mass index (BMI)) of ⩾26 vs <16.3 cm was 1.85 (95% CI 1.55 to 2.21) for the white population, 0.95 (95% CI 0.61 to 1.48) for the black population and 0.64 (95% CI 0.18 to 2.30) for Asians. The mean abdominal diameter was greater in men (22.0 cm, 95% CI 21.9 to 22.0) than in women (20.1 cm, 95% CI 20.0 to 20.1, p<0.01), but the risk of symptoms for any given diameter did not differ markedly by gender. The association between increasing BMI and symptoms was also much stronger among the white population than among the black population. The association between BMI and reflux‐type symptoms was partially mediated through abdominal diameter. Conclusions There was a consistent association between abdominal diameter (independent of BMI) and reflux‐type symptoms in the white population, but no consistent associations in the black population or Asians. The BMI association was also strongest among the white population. These findings, combined with the increased prevalence of abdominal obesity in male subjects, suggest that an increased obesity may disproportionately increase GORD‐type symptoms in the white population and in male subjects. PMID:17047097
Structure of the New England herring gull population
Kadlec, J.A.; Drury, W.H.
1968-01-01
Measurements of the rates of population increase, reproduction, and mortality together with an observed age ratio, were used to analyze the population of the Herring Gull in New England. Data from sporadic censuses prior to this study, aerial censuses by the authors, and National Audubon Society Christmas Bird Count indicated that the New England breeding population has been doubling every 12 to 15 years since the early 1900's. This increase has involved founding new colonies and expanding the breeding range There is evidence that 15 to 30% of the adults do not breed in any given year. Sixty-one productivity measurements on 43 islands from 1963 through 1966, involving almost 13,000 nests, showed that from 0.8 to 1.4 young/breeding pair/year is the usual range of rate of production. The age distribution in the population was determined by classifying Herring Gulls by plumage category on an aerial census of the coast from Tampico, Mexico, to Cape Sable, Nova Scotia. Of the 622,000 gulls observed, 68% were adults, 17% were second- and third-year birds, and 15% were first-year birds. Mortality rates derived from band recovery data were too high to be consistent with the observed rate of population growth, productivity, and age structure. Loss of bands increasing to the rate of about 20%/year 5 years after banding eliminates most of the discrepancy. The age structure and rate of population increase indicate a mortality rate of 4 to 9% for gulls 2 years old or older, compared with the 25 to 30% indicated by band recoveries. The population structure we have developed fits everything we have observed about Herring Gull population dynamics, except mortality based on band recoveries.
Prevalence and distribution of dental restorative materials in US Air Force veterans.
Albertini, T F; Kingman, A; Brown, L J
1997-01-01
Millions of restorative procedures are performed annually in the United States, yet very little is known about their distribution in the general population. With increasing concern about potential adverse health effects of some restorative materials, a better understanding of the extent of exposure to these materials in the population is important. The purpose of this study is to report the prevalence, patterns, and distribution of dental restorative materials in a population of male veterans. This collaborative study with the US Air Force examined 1,166 male veterans to assess exposure to dental amalgam and other restorative materials. An inventory of dental materials in the study population was obtained through oral examinations. Dental materials were classified into five categories: (1) amalgam; (2) resin; (3) porcelain, cement, or temporary, including ionomer (PCT); (4) cast gold alloys/direct filling gold; and (5) other metals (OM). The mean age of the study participants was 52.9 years. Over 94 percent of the study participants were dentate. The study participants averaged 45.8 restored/replaced surfaces. Restored/replaced surfaces increased with age while the number of teeth decreased with age. The most frequently used restorative material was amalgam, averaging 19.89 surfaces per subject, followed by PCT (9.38), resins (8.99), OM (5.52), and gold (4.91). The distributions of restorative materials varied by age, arch type, and location in the mouth. The study population experienced substantial exposure to dental materials.
Study of genetic direct search algorithms for function optimization
NASA Technical Reports Server (NTRS)
Zeigler, B. P.
1974-01-01
The results are presented of a study to determine the performance of genetic direct search algorithms in solving function optimization problems arising in the optimal and adaptive control areas. The findings indicate that: (1) genetic algorithms can outperform standard algorithms in multimodal and/or noisy optimization situations, but suffer from lack of gradient exploitation facilities when gradient information can be utilized to guide the search. (2) For large populations, or low dimensional function spaces, mutation is a sufficient operator. However for small populations or high dimensional functions, crossover applied in about equal frequency with mutation is an optimum combination. (3) Complexity, in terms of storage space and running time, is significantly increased when population size is increased or the inversion operator, or the second level adaptation routine is added to the basic structure.
Does colour polymorphism enhance survival of prey populations?
Wennersten, Lena; Forsman, Anders
2009-01-01
That colour polymorphism may protect prey populations from predation is an old but rarely tested hypothesis. We examine whether colour polymorphic populations of prey exposed to avian predators in an ecologically valid visual context were exposed to increased extinction risk compared with monomorphic populations. We made 2976 artificial pastry prey, resembling Lepidoptera larvae, in four different colours and presented them in 124 monomorphic and 124 tetramorphic populations on tree trunks and branches such that they would be exposed to predation by free-living birds, and monitored their ‘survival’. Among monomorphic populations, there was a significant effect of prey coloration on survival, confirming that coloration influenced susceptibility to visually oriented predators. Survival of polymorphic populations was inferior to that of monomorphic green populations, but did not differ significantly from monomorphic brown, yellow or red populations. Differences in survival within polymorphic populations paralleled those seen among monomorphic populations; the red morph most frequently went extinct first and the green morph most frequently survived the longest. Our findings do not support the traditional protective polymorphism hypothesis and are in conflict with those of earlier studies. As a possible explanation to our findings, we offer a competing ‘giveaway cue’ hypothesis: that polymorphic populations may include one morph that attracts the attention of predators and that polymorphic populations therefore may suffer increased predation compared with some monomorphic populations. PMID:19324729
Density effect on great tit (Parus major) clutch size intensifies in a polluted environment.
Eeva, Tapio; Lehikoinen, Esa
2013-12-01
Long-term data on a great tit (Parus major) population breeding in a metal-polluted zone around a copper-nickel smelter indicate that, against expectations, the clutch size of this species is decreasing even though metal emissions in the area have decreased considerably over the past two decades. Here, we document long-term population-level changes in the clutch size of P. major and explore if changes in population density, population numbers of competing species, timing of breeding, breeding habitat, or female age distribution can explain decreasing clutch sizes. Clutch size of P. major decreased by one egg in the polluted zone during the past 21 years, while there was no significant change in clutch size in the unpolluted reference zone over this time period. Density of P. major nests was similar in both environments but increased threefold during the study period in both areas (from 0.8 to 2.4 nest/ha). In the polluted zone, clutch size has decreased as a response to a considerable increase in population density, while a corresponding density change in the unpolluted zone did not have such an effect. The other factors studied did not explain the clutch size trend. Fledgling numbers in the polluted environment have been relatively low since the beginning of the study period, and they do not show a corresponding decrease to that noted for the clutch size over the same time period. Our study shows that responses of commonly measured life-history parameters to anthropogenic pollution depend on the structure of the breeding population. Interactions between pollution and intrinsic population characters should therefore be taken into account in environmental studies.
Seri Masran, Siti Nor Ain; Ab Majid, Abdul Hafiz
2017-07-01
The tropical bed bug is scientifically recognized as a significant public health problem. While there is an increased awareness about their resurgence by medical and life science committees, efficient bed bug management still remains unresolved. The solution may soon arise, as information about bed bugs' infestation dynamics and systematics are becoming more distinguishable. Recent developments in studies about bed bugs are based on molecular intervention by determining their genetic variation and phylogeography. The aim of this study is to assess the phylogenetic relationships and genetic diversity among the populations of tropical bed bugs inhabiting Malaysia. A molecular genotyping study was conducted with 22 tropical bed bug populations composed of three individuals per population. The mitochondrial (COI) gene was used as a marker. The data obtained were analyzed using the T-Coffee, ClustalX, MEGA 6.0, and PAUP software. The results showed one main monophyletic clade that consisted of two groups: Ch01 and Ch02. Ch02 consists of samples from the Bandar Hilir population, differing from the other populations studied by one singleton base. However, as there were no changes in the amino acid, this singleton genetic variation was considered to have no effect on genetic differentiation. Ch01 shows similarity with some sequence of Cimex hemipterus (F.) from Thailand, suggesting an international diversity connection. The disparity index apparently suggests that all isolates are homogeneous populations and are supported by the low value of the mean pairwise distance between isolates. This study will increase the knowledge about phylogeographic diversity of tropical bed bug in Malaysia. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.
EVALUATING THE EFFECTS OF NEAR ROAD SOLID AND VEGETATION BARRIERS ON MSAT EXPOSURES
Public health concerns for populations living, working and going to school near high-traffic roadways has increased substantially in recent years. Air quality measurement studies indicate high pollutant concentrations can occur near these large roads, impacting population exposu...
Fujiwara, Takeo; Shinozaki, Tomohiro
2017-01-01
Objective Few longitudinal studies have examined the effect of tobacco price increase on both cessation among smokers and relapse among quitters. Our objective was to investigate the differential impact of the tobacco price increase on the changes in smoking status in the total population and various subgroups. Methods We analysed data from a Japanese nationally representative longitudinal study of 30 773 individuals aged 50–59 years (weighted sum of discrete-time number = 215 411) with smoking information, using inverse probability weighting to account for non-response at follow-up. Generalised estimating equation models were used to calculate the odds ratios (ORs) for smoking behavioural changes (cessation among smokers and relapse among quitters), using discrete-time design. Stratified analyses were conducted according to demographic, socioeconomic and health behavioural characteristics. Results From 2005 to 2012, current smoker prevalence among the middle-aged Japanese population decreased from 30.5% to 24.3%. Of all the factors surveyed, only the tobacco price increase in 2010 (up by 37%, the highest increase during the period) was significantly associated with both cessation among smokers (OR 2.14, 95% confidence interval 1.90 to 2.41) and prevention of relapse among quitters (0.60, 0.46 to 0.77). Regarding the subgroup analysis, the tobacco price increase was associated with a significant reduction in relapse in the lowest income, recent quitters and very poor health subgroups. However, different associations were observed for cessation; a significant association between price increase and cessation was observed among all subgroups except for the heavy smoker and recently unemployed subgroups. Conclusions We confirmed that the tobacco price rise was associated with increasing cessation and decreasing relapse concurrently. Furthermore, this price rise was associated with favourable smoking changes in nearly all population subgroups; a large differential impact was not observed across the various subgroups. PMID:26880743
Pazzaglia, Ugo E; Sibilia, Valeria; Congiu, Terenzio; Pagani, Francesca; Ravanelli, Marco; Zarattini, Guido
2015-07-01
Bone aging was studied in an experimental model (rabbit femur) in three populations aged 0.5, 1.5, and 7.5 years. Cortical bone histology was compared with a data set from a 1.5-month-old population of an earlier published paper. From 0.5-year-old onward, the mean femur length did not increase further. Thereafter, the mean marrow area increased and the cortical area decreased significantly with aging. This was associated with a structural pattern transformation from plexiform to laminar and then Haversian-like type. The distal meta-epiphysis bone trabecular density of the oldest populations also was significantly lower in specific regions of interest (ROI). Percentage sealed primary vascular canals in laminar bone significantly increased with aging without variation of percentage sealed secondary osteons. Remodeling rate reflected by the density of cutting cones did not significantly change among the age populations. These data suggest that laminar bone vascular pattern is more functional in the fast diaphyseal expansion but not much streamlined with the renewal of blood flow during secondary remodeling. Bone aging was characterized by: 1) secondary remodeling subendosteally; 2) increment of sealed primary vascular canals number; 3) increased calcium content of the cortex; 4) cortical and trabecular bone mass loss in specific ROIs. Taken together, the present data may give a morphological and morphometric basis to perform comparative studies on experimental models of osteoporosis in the rabbit. © 2015 Wiley Periodicals, Inc.
Aldosterone and glomerular filtration--observations in the general population.
Hannemann, Anke; Rettig, Rainer; Dittmann, Kathleen; Völzke, Henry; Endlich, Karlhans; Nauck, Matthias; Wallaschofski, Henri
2014-03-10
Increasing evidence suggests that aldosterone promotes renal damage. Since data on the association between aldosterone and renal function in the general population are sparse, we chose to address this issue. We investigated the associations between the plasma aldosterone concentration (PAC) or the aldosterone-to-renin ratio (ARR) and the estimated glomerular filtration rate (eGFR) in a sample of adult men and women from Northeast Germany. A study population of 1921 adult men and women who participated in the first follow-up of the Study of Health in Pomerania was selected. None of the subjects used drugs that alter PAC or ARR. The eGFR was calculated according to the four-variable Modification of Diet in Renal Disease formula. Chronic kidney disease (CKD) was defined as an eGFR < 60 ml/min/1.73 m2. Linear regression models, adjusted for sex, age, waist circumference, diabetes mellitus, smoking status, systolic and diastolic blood pressures, serum triglyceride concentrations and time of blood sampling revealed inverse associations of PAC or ARR with eGFR (ß-coefficient for log-transformed PAC -3.12, p < 0.001; ß-coefficient for log-transformed ARR -3.36, p < 0.001). Logistic regression models revealed increased odds for CKD with increasing PAC (odds ratio for a one standard deviation increase in PAC: 1.35, 95% confidence interval: 1.06-1.71). There was no statistically significant association between ARR and CKD. Our study demonstrates that PAC and ARR are inversely associated with the glomerular filtration rate in the general population.
An evaluation of population index and estimation techniques for tadpoles in desert pools
Jung, Robin E.; Dayton, Gage H.; Williamson, Stephen J.; Sauer, John R.; Droege, Sam
2002-01-01
Using visual (VI) and dip net indices (DI) and double-observer (DOE), removal (RE), and neutral red dye capture-recapture (CRE) estimates, we counted, estimated, and censused Couch's spadefoot (Scaphiopus couchii) and canyon treefrog (Hyla arenicolor) tadpole populations in Big Bend National Park, Texas. Initial dye experiments helped us determine appropriate dye concentrations and exposure times to use in mesocosm and field trials. The mesocosm study revealed higher tadpole detection rates, more accurate population estimates, and lower coefficients of variation among pools compared to those from the field study. In both mesocosm and field studies, CRE was the best method for estimating tadpole populations, followed by DOE and RE. In the field, RE, DI, and VI often underestimated populations in pools with higher tadpole numbers. DI improved with increased sampling. Larger pools supported larger tadpole populations, and tadpole detection rates in general decreased with increasing pool volume and surface area. Hence, pool size influenced bias in tadpole sampling. Across all techniques, tadpole detection rates differed among pools, indicating that sampling bias was inherent and techniques did not consistently sample the same proportion of tadpoles in each pool. Estimating bias (i.e., calculating detection rates) therefore was essential in assessing tadpole abundance. Unlike VI and DOE, DI, RE, and CRE could be used in turbid waters in which tadpoles are not visible. The tadpole population estimates we used accommodated differences in detection probabilities in simple desert pool environments but may not work in more complex habitats.
Hutchinson, Rebecca Newlin; Shin, Sonya
2014-01-01
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, perhaps due to low socioeconomic status and access to quality healthcare. Successful programs will address social determinants and increase healthcare access. Community-based outreach to bring health services to the most vulnerable may also be very helpful in this effort. Systematic review registration number N/A PMID:24454685
Peterson, C. Matthew; Johnstone, Erica B.; Hammoud, Ahmad O.; Stanford, Joseph B.; Varner, Michael W.; Kennedy, Anne; Chen, Zhen; Sun, Liping; Fujimoto, Victor Y.; Hediger, Mary L.; Buck Louis, Germaine M.
2014-01-01
OBJECTIVE We sought to identify risk factors for endometriosis and their consistency across study populations in the Endometriosis: Natural History, Diagnosis, and Outcomes (ENDO) Study. STUDY DESIGN In this prospective matched, exposure cohort design, 495 women aged 18–44 years undergoing pelvic surgery (exposed to surgery, operative cohort) were compared to an age- and residence-matched population cohort of 131 women (unexposed to surgery, populationcohort). Endometriosis was diagnosed visually at laparoscopy/laparotomy or by pelvic magnetic resonance imaging in the operative and population cohorts, respectively. Logistic regression estimated the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for each cohort. RESULTS The incidence of visualized endometriosis was 40% in the operative cohort (11.8% stage 3–4 by revised criteria from the American Society for Reproductive Medicine), and 11% stage 3–4 in the population cohort by magnetic resonance imaging. An infertility history increased the odds of an endometriosis diagnosis in both the operative (AOR, 2.43; 95% CI, 1.57–3.76) and population (AOR, 7.91; 95% CI, 1.69–37.2) cohorts. In the operative cohort only, dysmenorrhea (AOR, 2.46; 95% CI, 1.28–4.72) and pelvic pain (AOR, 3.67; 95% CI, 2.44–5.50) increased the odds of diagnosis, while gravidity (AOR, 0.49; 95% CI, 0.32–0.75), parity (AOR, 0.42; 95% CI, 0.28–0.64), and body mass index (AOR, 0.95; 95% CI, 0.93–0.98) decreased the odds of diagnosis. In all sensitivity analyses for different diagnostic subgroups, infertility history remained a strong risk factor. CONCLUSION An infertility history was a consistent risk factor for endometriosis in both the operative and population cohorts of the ENDO Study. Additionally, identified risk factors for endometriosis vary based upon cohort selection and diagnostic accuracy. Finally, endometriosis in the population may be more common than recognized. PMID:23454253
Morbidity and Mortality in Sarcoidosis
Gerke, Alicia K.
2015-01-01
Purpose of Review Chronic sarcoidosis is a complex disease with numerous comorbid conditions and can be fatal in some cases. Recognizing causes of morbidity and mortality is important to effectively select treatments, manage symptoms, and improve outcomes. The purpose of this review is to examine emerging knowledge on morbidity and mortality in sarcoidosis. Recent Findings Approximately one to five percent of patients with sarcoidosis die from complications of sarcoidosis. Recent population studies indicate that mortality may be increasing over the past decade. The reasons behind these trends are unclear, but could include increasing incidence, detection rates, severity of disease, or age of the population. Morbidity of sarcoidosis is reflected by a trend of increased hospitalizations over recent years and increased use of healthcare resources. Morbidity can be caused by organ damage from granulomatous inflammation, treatment complications, and psychosocial effects of the disease. Recent studies are focused on morbidity related to cardiopulmonary complications, bone health, and aging within the sarcoidosis population. Last, sarcoidosis is associated with autoimmune diseases, pulmonary embolism, and malignancy; however, the underlying mechanisms linking diseases continue to be debated. Summary Morbidity in sarcoidosis is significant and multifactorial. Mortality is infrequent, but may be increasing over the years. PMID:25029298
Impact of different study populations on reader behavior and performance metrics: initial results
NASA Astrophysics Data System (ADS)
Gallas, Brandon D.; Pisano, Etta; Cole, Elodia; Myers, Kyle
2017-03-01
The FDA recently completed a study on design methodologies surrounding the Validation of Imaging Premarket Evaluation and Regulation called VIPER. VIPER consisted of five large reader sub-studies to compare the impact of different study populations on reader behavior as seen by sensitivity, specificity, and AUC, the area under the ROC curve (receiver operating characteristic curve). The study investigated different prevalence levels and two kinds of sampling of non-cancer patients: a screening population and a challenge population. The VIPER study compared full-field digital mammography (FFDM) to screenfilm mammography (SFM) for women with heterogeneously dense or extremely dense breasts. All cases and corresponding images were sampled from Digital Mammographic Imaging Screening Trial (DMIST) archives. There were 20 readers (American Board Certified radiologists) for each sub-study, and instead of every reader reading every case (fully-crossed study), readers and cases were split into groups to reduce reader workload and the total number of observations (split-plot study). For data collection, readers first decided whether or not they would recall a patient. Following that decision, they provided an ROC score for how close or far that patient was from the recall decision threshold. Performance results for FFDM show that as prevalence increases to 50%, there is a moderate increase in sensitivity and decrease in specificity, whereas AUC is mainly flat. Regarding precision, the statistical efficiency (ratio of variances) of sensitivity and specificity relative to AUC are 0.66 at best and decrease with prevalence. Analyses comparing modalities and the study populations (screening vs. challenge) are still ongoing.
Impact of Different Study Populations on Reader Behavior and Performance Metrics: Initial Results
Gallas, Brandon D.; Pisano, Etta; Cole, Elodia; Myers, Kyle
2017-01-01
The FDA recently completed a study on design methodologies surrounding the Validation of Imaging Premarket Evaluation and Regulation called VIPER. VIPER consisted of five large reader sub-studies to compare the impact of different study populations on reader behavior as seen by sensitivity, specificity, and AUC, the area under the ROC curve (receiver operating characteristic curve). The study investigated different prevalence levels and two kinds of sampling of non-cancer patients: a screening population and a challenge population. The VIPER study compared full-field digital mammography (FFDM) to screen-film mammography (SFM) for women with heterogeneously dense or extremely dense breasts. All cases and corresponding images were sampled from Digital Mammographic Imaging Screening Trial (DMIST) archives. There were 20 readers (American Board Certified radiologists) for each sub-study, and instead of every reader reading every case (fully-crossed study), readers and cases were split into groups to reduce reader workload and the total number of observations (split-plot study). For data collection, readers first decided whether or not they would recall a patient. Following that decision, they provided an ROC score for how close or far that patient was from the recall decision threshold. Performance results for FFDM show that as prevalence increases to 50%, there is a moderate increase in sensitivity and decrease in specificity, whereas AUC is mainly flat. Regarding precision, the statistical efficiency (ratio of variances) of sensitivity and specificity relative to AUC are 0.66 at best and decrease with prevalence. Analyses comparing modalities and the study populations (screening vs. challenge) are still ongoing. PMID:28845078
Occupation and thyroid cancer: a population-based case-control study in Connecticut
Ba, Yue; Huang, Huang; Lerro, Catherine C.; Li, Shuzhen; Zhao, Nan; Li, Anqi; Ma, Shuangge; Udelsman, Robert; Zhang, Yawei
2016-01-01
Objective The study aims to explore the associations between various occupations and thyroid cancer risk. Methods A population-based case-control study involving 462 histologically confirmed incident cases and 498 controls was conducted in Connecticut in 2010–2011. Results A significantly increased risk of thyroid cancer, particularly papillary microcarcinoma, was observed for those working as the healthcare practitioners and technical workers, health diagnosing and treating practitioners and registered nurses. Those working in building and grounds cleaning, maintenance occupations, pest control, retail sales, and customer service also had increased risk for papillary thyroid cancer. Subjects who worked as cooks, janitors, cleaners, and customer service representatives were at an increased risk of papillary thyroid cancer with tumor size >1 cm. Conclusions Certain occupations were associated with an increased risk of thyroid cancer, with some tumor size and subtype specificity. PMID:26949881
Schregel, Julia; Kopatz, Alexander; Eiken, Hans Geir; Swenson, Jon E; Hagen, Snorre B
2017-01-01
The degree of gene flow within and among populations, i.e. genetic population connectivity, may closely track demographic population connectivity. Alternatively, the rate of gene flow may change relative to the rate of dispersal. In this study, we explored the relationship between genetic and demographic population connectivity using the Scandinavian brown bear as model species, due to its pronounced male dispersal and female philopatry. Thus, we expected that females would shape genetic structure locally, whereas males would act as genetic mediators among regions. To test this, we used eight validated microsatellite markers on 1531 individuals sampled noninvasively during country-wide genetic population monitoring in Sweden and Norway from 2006 to 2013. First, we determined sex-specific genetic structure and substructure across the study area. Second, we compared genetic differentiation, migration/gene flow patterns, and spatial autocorrelation results between the sexes both within and among genetic clusters and geographic regions. Our results indicated that demographic connectivity was not a reliable indicator of genetic connectivity. Among regions, we found no consistent difference in long-term gene flow and estimated current migration rates between males and females. Within regions/genetic clusters, only females consistently displayed significant positive spatial autocorrelation, indicating male-biased small-scale dispersal. In one cluster, however, males showed a dispersal pattern similar to females. The Scandinavian brown bear population has experienced substantial recovery over the last decades; however, our results did not show any changes in its large-scale population structure compared to previous studies, suggesting that an increase in population size and dispersal of individuals does not necessary lead to increased genetic connectivity. Thus, we conclude that both genetic and demographic connectivity should be estimated, so as not to make false assumptions about the reality of wildlife populations.
Heat exposure in cities: combining the dynamics of temperature and population
NASA Astrophysics Data System (ADS)
Hu, L.; Wilhelmi, O.; Uejio, C. K.
2017-12-01
Assessment of human exposure to extreme heat requires the distributions of temperature and population. However, both variables are dynamic, thus presenting many challenges in capturing temperature and population patterns spatially and over time in an urban context. This study aims to improve the understanding of spatiotemporal patterns of urban population exposure to heat, taking Chicago, USA as an example. We estimate the hourly, geographically variable, population distribution considering commute of workers and students in a regular weekday and analyze the diurnal air temperature patterns during different meteorological conditions from satellite observations. The results show a relatively larger temperature increase in less urbanized areas during extreme heat events (EHEs), resulting in a spatially homogeneous temperature distribution over Chicago Metropolitan area. A lake cooling effect is weaker during EHEs. Population dynamics due to daily commute determine higher population density in more urbanized areas during daytime. The city-wide analysis reveals that the exposure is more sensitive to the nighttime temperature increases, and EHEs enhance this sensitivity. The high exposure hotspots are identified at the northwest Chicago, Cicero and Oak Park areas, where the influence from Lake Michigan is weakened, while the spatial extent of high outdoor exposure areas varies diurnally. This study's findings have potential to better inform general heat mitigation strategies during hot summer months and facilitate emergency response during EHEs. Availability of remotely-sensed temperature observations as well as the workers and students commute-adjusted population data allows for the adoption of this study's methodology in other major metropolitan areas. A better understanding of space-time patterns of urban population's exposure to heat will further enable local decision makers to mitigate extreme heat health risks and develop more targeted heat preparedness and response strategies.
Increased prevalence of metabolic syndrome in non-obese asian Indian-an urban-rural comparison.
Mahadik, S R; Deo, S S; Mehtalia, S D
2007-06-01
In the present study we evaluated the association of insulin resistance (IR) with different components of Metabolic Syndrome (MS) in an Asian Indian population, and performed a comparative study between urban and rural populations of India. A Total of 267 urban men and women aged 25-70 years participated in this study. RESULTS were compared with rural data from a previously published study. Fasting serum insulin, uric acid, and lipid profile were measured along with fasting and 2 hour plasma glucose. Association of MS and IR was studied by using univariate regression analysis. Prevalence of MS was significantly higher in the urban population compared to that of the rural population (35.2% vs 20.6%, chi(2) = 23.2, p < 0.001). Calculated insulin resistence (HOMA-IR) was common in MS group of both populations. Percentage prevalence of IR was high and almost the same in both population (42%). Percentage prevalence of abdominal obesity and hypertriglyceridemia was significantly higher in the urban population compared to the rural population. Linear regression analysis of IR significantly correlated with different components of MS of both the population. The significant finding of the present study was that the rural population exhibited a high prevalence of MS and IR, though nonobese. IR correlated with components of MS not only in the urban but also in the rural population. To reduce the incidence of Type 2 Diabetes (T2DM) and cardiovascular disease (CVD) in our populations, early identification of populations at risk based on prevalence of MS and IR will become of prime importance.
Zhang, Boya; Li, Guoxing; Ma, Yue; Pan, Xiaochuan
2018-04-01
Human health faces unprecedented challenges caused by climate change. Thus, studies of the effect of temperature change on total mortality have been conducted in numerous countries. However, few of those studies focused on temperature-related mortality due to cardiovascular disease (CVD) or considered future population changes and adaptation to climate change. We present herein a projection of temperature-related mortality due to CVD under different climate change, population, and adaptation scenarios in Beijing, a megacity in China. To this end, 19 global circulation models (GCMs), 3 representative concentration pathways (RCPs), 3 socioeconomic pathways, together with generalized linear models and distributed lag non-linear models, were used to project future temperature-related CVD mortality during periods centered around the years 2050 and 2070. The number of temperature-related CVD deaths in Beijing is projected to increase by 3.5-10.2% under different RCP scenarios compared with that during the baseline period. Using the same GCM, the future daily maximum temperatures projected using the RCP2.6, RCP4.5, and RCP8.5 scenarios showed a gradually increasing trend. When population change is considered, the annual rate of increase in temperature-related CVD deaths was up to fivefold greater than that under no-population-change scenarios. The decrease in the number of cold-related deaths did not compensate for the increase in that of heat-related deaths, leading to a general increase in the number of temperature-related deaths due to CVD in Beijing. In addition, adaptation to climate change may enhance rather than ameliorate the effect of climate change, as the increase in cold-related CVD mortality greater than the decrease in heat-related CVD mortality in the adaptation scenarios will result in an increase in the total number of temperature-related CVD mortalities. Copyright © 2018 Elsevier Inc. All rights reserved.
Familial link of otitis media requiring tympanostomy tubes.
Padia, Reema; Alt, Jeremiah A; Curtin, Karen; Muntz, Harlan R; Orlandi, Richard R; Berger, Justin; Meier, Jeremy D
2017-04-01
Placement of tympanostomy tubes for recurrent or chronic otitis media is the most commonly performed ambulatory procedure in the United States. Etiologies have been speculated to be environmentally based, and studies have suggested a genetic component to the disease. However, no large-scale studies have attempted to define a familial component. The objective of this study was to determine the familial risk of otitis media requiring tympanostomy tubes (OMwTT) in a statewide population. Retrospective observational cohort study with population-based matched controls. Using an extensive genealogical database linked to medical records, the familial risk of OMwTT was calculated for relatives of probands (46,249 patients diagnosed with OMwTT from 1996-2013) compared to random population controls matched 5:1 on sex and birth year from logistic regression models. The median age at time of tympanostomy tube placement was 1 year (interquartile range, 0-2 years). First-degree relatives of patients with OMwTT, primarily siblings, had a 5-fold increased risk of OMwTT (P < 10 -16 ). Second-degree relatives were at a 1.5-fold increased risk (P < 10 -15 ). More extended relatives (third, fourth and fifth degree) showed a 1.4-fold increased risk (P < 10 -15 ). In the largest population-based study to date, a significant familial risk is confirmed in OMwTT, suggesting otitis media may have a significant genetic component given the increased risk found in close as well as distant relatives. This could be influenced by shared environments given a five-times risk observed in siblings. Further understanding the genetic basis of OMwTT and its interplay with environmental factors may clarify the etiology and lead to better detection of disease and treatments. 3b. Laryngoscope, 127:962-966, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.
NASA Astrophysics Data System (ADS)
Xie, Zhihao; Xiao, Hui; Tang, Xuexi; Cai, Hengjiang
2009-06-01
The interspecific interactions between the rotifer Brachionus plicatilis and two harmful algal blooms (HAB) species were investigated experimentally by single culture method. B. plicatilis population and the growth of the two algae were compared at different algal cell densities. The results demonstrated that the B. plicatilis obtained sufficient nutrition from Prorocentrum donghaiense to support net population increase. With exposure to 2.5×104 cells mL-1 of P. donghaiense, the number of B. plicatilis increased faster than it did when exposed to other four algal densities (5, 10, 15 and 20 ×104 cells mL-1), and the increase rate of B. plicatilis population ( r) at this algal density was 0.104 ± 0.015 rd-1. Cell densities of P. donghaiense decreased due to the grazing of B. plicatilis. In contrast, Heterosigma akashiwo had an adverse effect on B. plicatilis population and its growth was largely unaffected by rotifer grazing. In this case, B. plicatilis population decreased and H. akashiwo grew at a rate similar to that of the control.
Ghosh, Anirban; Baltekin, Özden; Wäneskog, Marcus; Elkhalifa, Dina; Hammarlöf, Disa L; Elf, Johan; Koskiniemi, Sanna
2018-05-02
Bacterial populations can use bet-hedging strategies to cope with rapidly changing environments. One example is non-growing cells in clonal bacterial populations that are able to persist antibiotic treatment. Previous studies suggest that persisters arise in bacterial populations either stochastically through variation in levels of global signalling molecules between individual cells, or in response to various stresses. Here, we show that toxins used in contact-dependent growth inhibition (CDI) create persisters upon direct contact with cells lacking sufficient levels of CdiI immunity protein, which would otherwise bind to and neutralize toxin activity. CDI-mediated persisters form through a feedforward cycle where the toxic activity of the CdiA toxin increases cellular (p)ppGpp levels, which results in Lon-mediated degradation of the immunity protein and more free toxin. Thus, CDI systems mediate a population density-dependent bet-hedging strategy, where the fraction of non-growing cells is increased only when there are many cells of the same genotype. This may be one of the mechanisms of how CDI systems increase the fitness of their hosts. © 2018 The Authors.
Sex ratio rather than population size affects genetic diversity in Antennaria dioica.
Rosche, C; Schrieber, K; Lachmuth, S; Durka, W; Hirsch, H; Wagner, V; Schleuning, M; Hensen, I
2018-03-09
Habitat fragmentation and small population size can lead to genetic erosion in threatened plant populations. Classical theory implies that dioecy can counteract genetic erosion as it decreases the magnitude of inbreeding and genetic drift due to obligate outcrossing. However, in small populations, sex ratios may be strongly male- or female-biased, leading to substantial reductions in effective population size. This may theoretically result in a unimodal relationship between sex ratios and genetic diversity; yet, empirical studies on this relationship are scarce. Using AFLP markers, we studied genetic diversity, structure and differentiation in 14 highly fragmented Antennaria dioica populations from the Central European lowlands. Our analyses focused on the relationship between sex ratio, population size and genetic diversity. Although most populations were small (mean: 35.5 patches), genetic diversity was moderately high. We found evidence for isolation-by-distance, but overall differentiation of the populations was rather weak. Females dominated 11 populations, which overall resulted in a slightly female-biased sex ratio (61.5%). There was no significant relationship between population size and genetic diversity. The proportion of females was not unimodally but positively linearly related to genetic diversity. The high genetic diversity and low genetic differentiation suggest that A. dioica has been widely distributed in the Central European lowlands in the past, while fragmentation occurred only in the last decades. Sex ratio has more immediate consequences on genetic diversity than population size. An increasing proportion of females can increase genetic diversity in dioecious plants, probably due to a higher amount of sexual reproduction. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.
NASA Technical Reports Server (NTRS)
Veldkamp, T. I. E.; Wada, Y.; Aerts, J. C. J. H.; Ward, P. J.
2016-01-01
Changing hydro-climatic and socioeconomic conditions increasingly put pressure on fresh water resources and are expected to aggravate water scarcity conditions towards the future. Despite numerous calls for risk-based water scarcity assessments, a global-scale framework that includes UNISDR's definition of risk does not yet exist. This study provides a first step towards such a risk based assessment, applying a Gamma distribution to estimate water scarcity conditions at the global scale under historic and future conditions, using multiple climate change and population growth scenarios. Our study highlights that water scarcity risk, expressed in terms of expected annual exposed population, increases given all future scenarios, up to greater than 56.2% of the global population in 2080. Looking at the drivers of risk, we find that population growth outweigh the impacts of climate change at global and regional scales. Using a risk-based method to assess water scarcity, we show the results to be less sensitive than traditional water scarcity assessments to the use of fixed threshold to represent different levels of water scarcity. This becomes especially important when moving from global to local scales, whereby deviations increase up to 50% of estimated risk levels.
Ježić, Marin; Mlinarec, Jelena; Vuković, Rosemary; Katanić, Zorana; Krstin, Ljiljana; Nuskern, Lucija; Poljak, Igor; Idžojtić, Marilena; Tkalec, Mirta; Ćurković-Perica, Mirna
2018-07-01
Invasive species, especially plant pathogens, have a potential to completely eradicate native plant species and remodel landscapes. Tripartite interactions among sweet chestnut (Castanea sativa), chestnut blight-causing invasive fungus Cryphonectria parasitica, and hyperparasitic virus Cryphonectria hypovirus 1 (CHV1) were studied in two populations. The number of different vegetative compatibility (vc) types of C. parasitica more than doubled over the 10 years, while the hypovirulence incidence dropped in one population and slightly increased in the other one. Over the course of our 3-year monitoring experiment, the prevalence of hypovirulent isolates obtained from monitored cankers increased slowly (i.e., more hypovirulent isolates were being obtained from the same cankers over time). Within studied cankers, considerable changes in vc type and CHV1 presence were observed, indicating a highly dynamic system in which virulent and hypovirulent mycelia, sometimes of discordant vc types, often appeared together. The increase in hypovirulence prevalence did not have any observable curative effect on the cankers and, occasionally, reactivation of healed cankers by new, virulent C. parasitica isolates was observed. Both short- and long-term observations and revalidation of the infected plant populations are necessary to accurately estimate disease progress and formulate an adequate disease management strategy.
Fung, Christina; McIsaac, Jessie-Lee D; Kuhle, Stefan; Kirk, Sara F L; Veugelers, Paul J
2013-12-01
The objective of this study is to assess population-level trends in children's dietary intake and weight status before and after the implementation of a provincial school nutrition policy in the province of Nova Scotia, Canada. Self-reported dietary behavior and nutrient intake and measured body mass index were collected as part of a population-level study with grade 5 students in 2003 (n=5215) and 2011 (5508), prior to and following implementation of the policy. We applied random effects regression methods to assess the effect of the policy on dietary and health outcomes. In 2011, students reported consuming more milk products, while there was no difference in mean consumption of vegetables and fruits in adjusted models. Adjusted regression analysis revealed a statistically significant decrease in sugar-sweetened beverage consumption. Despite significant temporal decreases in dietary energy intake and increases in diet quality, prevalence rates of overweight and obesity continued to increase. This population-level intervention research suggests a positive influence of school nutrition policies on diet quality, energy intake and healthy beverage consumption, and that more action beyond schools is needed to curb the increases in the prevalence of childhood obesity. © 2013.
Korean Variant Archive (KOVA): a reference database of genetic variations in the Korean population.
Lee, Sangmoon; Seo, Jihae; Park, Jinman; Nam, Jae-Yong; Choi, Ahyoung; Ignatius, Jason S; Bjornson, Robert D; Chae, Jong-Hee; Jang, In-Jin; Lee, Sanghyuk; Park, Woong-Yang; Baek, Daehyun; Choi, Murim
2017-06-27
Despite efforts to interrogate human genome variation through large-scale databases, systematic preference toward populations of Caucasian descendants has resulted in unintended reduction of power in studying non-Caucasians. Here we report a compilation of coding variants from 1,055 healthy Korean individuals (KOVA; Korean Variant Archive). The samples were sequenced to a mean depth of 75x, yielding 101 singleton variants per individual. Population genetics analysis demonstrates that the Korean population is a distinct ethnic group comparable to other discrete ethnic groups in Africa and Europe, providing a rationale for such independent genomic datasets. Indeed, KOVA conferred 22.8% increased variant filtering power in addition to Exome Aggregation Consortium (ExAC) when used on Korean exomes. Functional assessment of nonsynonymous variant supported the presence of purifying selection in Koreans. Analysis of copy number variants detected 5.2 deletions and 10.3 amplifications per individual with an increased fraction of novel variants among smaller and rarer copy number variable segments. We also report a list of germline variants that are associated with increased tumor susceptibility. This catalog can function as a critical addition to the pre-existing variant databases in pursuing genetic studies of Korean individuals.
Promoting effects on reproduction increase population vulnerability of Daphnia magna.
Agatz, Annika; Hammers-Wirtz, Monika; Gabsi, Faten; Ratte, Hans Toni; Brown, Colin D; Preuss, Thomas G
2012-07-01
Environmental risk assessment of chemicals is based on single species tests at the individual level with single compounds. However, the protection goal is the sustainability of a population, which faces several natural stressors and mixtures of chemicals in the environment. Therefore, experiments were undertaken to quantify the combined effects of chemicals with different modes of action on Daphnia magna populations. Populations continuously exposed to dispersogen A and at abundance equilibrium were treated with a 2-d pulse of p353-nonylphenol. In previous studies, dispersogen A was shown to act as a natural info-chemical, promoting the reproduction of daphnids (higher offspring quantity) coupled with reduced offspring fitness, whereas nonylphenol in pulsed-exposure caused size-selective mortality. Dispersogen A caused accelerated population growth to maximum abundance, shifted the population structure towards smaller individuals, and increased the population sensitivity to nonylphenol. The authors showed that a positive effect observed at the individual level can be transposed to a negative effect when monitored at the population level. So far, positive effects are not addressed in environmental risk assessment, and even in higher-tier testing, population structure is not quantified. Both factors indicate a potential mismatch between protection aim and risk assessment practice. Copyright © 2012 SETAC.
Including the Group Quarters Population in the US Synthesized Population Database
Chasteen, Bernadette M.; Wheaton, William D.; Cooley, Philip C.; Ganapathi, Laxminarayana; Wagener, Diane K.
2011-01-01
In 2005, RTI International researchers developed methods to generate synthesized population data on US households for the US Synthesized Population Database. These data are used in agent-based modeling, which simulates large-scale social networks to test how changes in the behaviors of individuals affect the overall network. Group quarters are residences where individuals live in close proximity and interact frequently. Although the Synthesized Population Database represents the population living in households, data for the nation’s group quarters residents are not easily quantified because of US Census Bureau reporting methods designed to protect individuals’ privacy. Including group quarters population data can be an important factor in agent-based modeling because the number of residents and the frequency of their interactions are variables that directly affect modeling results. Particularly with infectious disease modeling, the increased frequency of agent interaction may increase the probability of infectious disease transmission between individuals and the probability of disease outbreaks. This report reviews our methods to synthesize data on group quarters residents to match US Census Bureau data. Our goal in developing the Group Quarters Population Database was to enable its use with RTI’s US Synthesized Population Database in the Modeling of Infectious Diseases Agent Study. PMID:21841972
Blair, Andrew
2004-07-01
New Zealand is a little country with a little economy but with a population that's rapidly aging. New Zealand's population is only 4.3 million people. It's GDP is only $US58.6 billion (2002). New Zealand's expenditure on health as a percentage of GDP is not out of line with that of other countries. As a nation we have been increasing expenditure on health over recent years. In 1990 we spent 7% of GDP on health. In 1995 that increased to 7.65% and is now 8.3%. However, in per capita terms our expenditure on health does not compare so well with like countries. The size of New Zealand's economy is restricting what our country spends on health. Health is already the second highest demand on the New Zealand tax dollar. The tolerance of New Zealanders would be challenged if a Government attempted to increase taxes further to meet the growing demands for expenditure on health, but at the same time the population's expectations are increasing. This is the challenging situation we face today. What lies ahead? Like all industrialized countries New Zealand is facing an aging population. The population below age 40 is decreasing, but it is increasing significantly over that age. 16% of the population is currently aged over 60. By 2051 this proportion will almost double to just over 31%. Coupled with the aging population is increased awareness and expectations, as access to options for treatment and technology becomes readily accessible to the population through such media as the internet. The extent of the impact of the aging population can be clearly represented by focusing on one specialty such as orthopaedics. The New Zealand Orthopaecic Association undertook a study in July 2003 which concluded (among other things) that as a result of the projected aging of the population, over the next 50 years: Musculo-skeletal operations will increase by over 30%. The number of hip replacements will nearly double. The incidence of osteoporosis will increase by a massive 201%. The number of people affected by arthritis will increase by nearly 50%. A huge increase in numbers affected with musculoskeletal conditions will require significant increases in health care resources, including hospital beds and facilities, orthopaedic surgeons and other health care professionals. New Zealand has been slow to acknowledge and plan for the increased demand for health services which is looming. Growing New Zealand's economy will help, but alone will not be enough. It is more than just finding the financial resources to better meet the demand. The enormous demands on the availability of treatment resources including hospital facilities and trained health care professionals must be addressed. There are major workforce issues to be faced. The change in population distribution between young and old will have an impact and it will be necessary to ensure that there are sufficient numbers of properly trained health care professionals available at all levels. It is hoped that improvements in preventative care programmes and new technologies and treatment techniques may reduce the rate of demand. As the health of our population is improved through targeted programmes dealing with obesity, diabetes, smoking and accident prevention, it may be possible to reallocate or change the focus of resources within the health and hospital sectors. Many countries are developing national strategies for their aging population. Clearly the New Zealand Government needs to move swiftly to develop a plan to manage the increased burden that is developing as a result of the aging population. That plan must create an environment which facilitates, encourages and supports greater private investment in healthcare facilities and healthcare delivery. Incentives must be created to motivate individuals to take greater responsibility for their healthcare needs and the funding of it. The development of a long term strategy to meet the challenges of the aging population is a priority.
Indonesia (country/area statements).
1985-09-01
According to this statement presented to the Committee on Population of the UN Economic and Social Commission for Asia and the Pacific, the 3 main problems of the Indonesian population concern growth, distribution, and the quality of the population in relation to socioeconomic development. At the beginning of the 1st 5-year development plan in 1969, fertility was estimated at 44/1000, mortality at 19/1000, and infant mortality at 140; by 1984, the crude birth rate was 34/1000, the crude death rate 12/1000, and the growth rate about 2.2%. Infant mortality is expected to drop to 70/1000 by 1988. Development and improvements in nutrition, public health, and curative medicine have been responsible for most of the mortality decline. The major causes of death are infectious and parasitic diseases. The decline in fertility has been attributed to the family planning program; currently 55% of eligible couples practice family planning. The maldistribution of the population among the 13,677 islands of the archipelago is due to geographic factors as well as to the former colonial policy favoring the island of Java. A resettlement program resettled 500,000 persons during the 3rd plan period starting in 1979, and the 4th plan aims to resettle about 750,000 people from Java, Bali, and Lombok. Migration between islands has been increasing because of differentials in the speed of development. The urban population is expected to increase from 22% in 1980 to 40% by 2000. Jakarta's population of 6.5 million is expected to increase to 15 million and the national population from 165 million to 216 million. Studies are underway to identify ways of improving the physical and nonphysical qualities of the population to increase productivity and creativity. In the past decade, teaching and research as well as information, education, and communication efforts have spread to all parts of the country. Present government policy is gradually to shift responsibility for family planning to the community, with the Women's Programme for Family welfare run by village women leaders in each of the 66,000 villages serving as the main channel. Indonesian volunteer organizations in population and family planning are playing an important role at the grassroots level. Migration data in Indonesia is available only for destinations. Most of the rural migration from Java, Bali and Lombok consists of participants in government resettlement programs. Recent studies have shown that natural increase contributed about 60% to urbanization, rural-urban migration about 30%, and reclassification about 10%. The community oriented primary health care program has established new health centers and significantly increased health manpower. To enhance the role of women in socioeconomic development, the family planning program has introduced income-generating schemes in rural areas throughout the country. A network of information services on population and family planning has been established, and the government is working on the Indonesian Population Plan of Action to provide a longterm perspective on integrating population and development.
Vitek, Charles R.; Čakalo, Jurja-Ivana; Kruglov, Yuri V.; Dumchev, Konstantin V.; Salyuk, Tetyana O.; Božičević, Ivana; Baughman, Andrew L.; Spindler, Hilary H.; Martsynovska, Violetta A.; Kobyshcha, Yuri V.; Abdul-Quader, Abu S.; Rutherford, George W.
2014-01-01
Background Ukraine developed Europe's most severe HIV epidemic due to widespread transmission among persons who inject drugs (PWID). Since 2004, prevention has focused on key populations; antiretroviral therapy (ART) coverage has increased. Recent data show increases in reported HIV cases through 2011, especially attributed to sexual transmission, but also signs of potential epidemic slowing. We conducted a data triangulation exercise to better analyze available data and inform program implementation. Methods and Findings We reviewed data for 2005 to 2012 from multiple sources, primarily national HIV case reporting and integrated biobehavioral surveillance (IBBS) studies among key populations. Annually reported HIV cases increased at a progressively slower rate through 2011 with recent increases only among older, more immunosuppressed individuals; cases decreased 2.7% in 2012. Among women <25 years of age, cases attributed to heterosexual transmission and HIV prevalence in antenatal screening declined after 2008. Reported cases among young PWID declined by three-fourths. In 2011, integrated biobehavioral surveillance demonstrated decreased HIV prevalence among young members of key populations compared with 2009. HIV infection among female sex workers (FSW) remains strongly associated with a personal history of injecting drug use (IDU). Conclusions This analysis suggests that Ukraine's HIV epidemic has slowed, with decreasing reported cases and older cases predominating among those diagnosed. Recent decreases in cases and in prevalence support decreased incidence among young PWID and women. Trends among heterosexual men and men who have sex with men (MSM) are less clear; further study and enhanced MSM prevention are needed. FSW appear to have stable prevalence with risk strongly associated with IDU. Current trends suggest the Ukrainian epidemic can be contained with enhanced prevention among key populations and increased treatment access. PMID:25251080
de Sá Rodrigues, L C; Holmes, K E; Thompson, V; Newton, M A; Stein, T J
2017-03-01
An increased serum alkaline phosphatase concentration is known to be associated with a negative prognosis in canine and human osteosarcoma. To expand upon previous studies regarding the biological relevance of increased serum alkaline phosphatase as a negative prognostic factor, xenogeneic heterotopic transplants were performed using six canine primary osteosarcoma cell lines generated from patients with differing serum alkaline phosphatase concentrations (three normal and three increased). Three of the six cell lines were capable of generating tumours and tumour formation was independent of the serum alkaline phosphatase status of the cell line. Microarray analysis identified 379 genes as being differentially expressed between the tumourigenic and non-tumourigenic cell lines. Frizzled-6 was upregulated to the greatest extent (7.78-fold) in tumourigenic cell lines compared with non-tumourigenic cell lines. Frizzled-6, a co-receptor for Wnt ligands has been associated with enhanced tumour-initiating cells and poor prognosis for other tumours. The increased expression of frizzled-6 was confirmed by quantitative reverse transcription polymerase chain reaction (QPCR) and Western blot analysis. Additionally, the tumourigenic cell lines also had an increase in the percentage of side population cells compared with non-tumourigenic cell lines (5.89% versus 1.58%, respectively). There were no differences in tumourigenicity, frizzled-6 or percentage of side population cells noted between osteosarcoma cell lines generated from patients of differing serum alkaline phosphatase concentration. However, to our knowledge this is the first study to identified frizzled-6 as a possible marker of osteosarcoma cell populations with enhanced tumourigenicity and side population cells. Future work will focus on defining the role of frizzled-6 in osteosarcoma tumourigenesis and tumour-initiating cells. © 2015 John Wiley & Sons Ltd.
An alternative covariance estimator to investigate genetic heterogeneity in populations.
Heslot, Nicolas; Jannink, Jean-Luc
2015-11-26
For genomic prediction and genome-wide association studies (GWAS) using mixed models, covariance between individuals is estimated using molecular markers. Based on the properties of mixed models, using available molecular data for prediction is optimal if this covariance is known. Under this assumption, adding individuals to the analysis should never be detrimental. However, some empirical studies showed that increasing training population size decreased prediction accuracy. Recently, results from theoretical models indicated that even if marker density is high and the genetic architecture of traits is controlled by many loci with small additive effects, the covariance between individuals, which depends on relationships at causal loci, is not always well estimated by the whole-genome kinship. We propose an alternative covariance estimator named K-kernel, to account for potential genetic heterogeneity between populations that is characterized by a lack of genetic correlation, and to limit the information flow between a priori unknown populations in a trait-specific manner. This is similar to a multi-trait model and parameters are estimated by REML and, in extreme cases, it can allow for an independent genetic architecture between populations. As such, K-kernel is useful to study the problem of the design of training populations. K-kernel was compared to other covariance estimators or kernels to examine its fit to the data, cross-validated accuracy and suitability for GWAS on several datasets. It provides a significantly better fit to the data than the genomic best linear unbiased prediction model and, in some cases it performs better than other kernels such as the Gaussian kernel, as shown by an empirical null distribution. In GWAS simulations, alternative kernels control type I errors as well as or better than the classical whole-genome kinship and increase statistical power. No or small gains were observed in cross-validated prediction accuracy. This alternative covariance estimator can be used to gain insight into trait-specific genetic heterogeneity by identifying relevant sub-populations that lack genetic correlation between them. Genetic correlation can be 0 between identified sub-populations by performing automatic selection of relevant sets of individuals to be included in the training population. It may also increase statistical power in GWAS.
2012-01-01
Background The Asian population is one of the fastest growing ethnic minority groups in western countries. However, cancer screening uptake is consistently lower in this group than in the native-born populations. As a first step towards developing an effective cancer screening intervention program targeting Asian women, we conducted a comprehensive systematic review, without geographic, language or date limitations, to update current knowledge on the effectiveness of existing intervention strategies to enhance breast and cervical screening uptake in Asian women. Methods This study systematically reviewed studies published as of January 2010 to synthesize knowledge about effectiveness of cancer screening interventions targeting Asian women. Fifteen multidisciplinary peer-reviewed and grey literature databases were searched to identify relevant studies. Results The results of our systematic review were reported in accordance with the PRISMA Statement. Of 37 selected intervention studies, only 18 studies included valid outcome measures (i.e. self-reported or recorded receipt of mammograms or Pap smear). 11 of the 18 intervention studies with valid outcome measures used multiple intervention strategies to target individuals in a specific Asian ethnic group. This observed pattern of intervention design supports the hypothesis that employing a combination of multiple strategies is more likely to be successful than single interventions. The effectiveness of community-based or workplace-based group education programs increases when additional supports, such as assistance in scheduling/attending screening and mobile screening services are provided. Combining cultural awareness training for health care professionals with outreach workers who can help healthcare professionals overcome language and cultural barriers is likely to improve cancer screening uptake. Media campaigns and mailed culturally sensitive print materials alone may be ineffective in increasing screening uptake. Intervention effectiveness appears to vary with ethnic population, methods of program delivery, and study setting. Conclusions Despite some limitations, our review has demonstrated that the effectiveness of existing interventions to promote breast and cervical cancer screening uptake in Asian women may hinge on a variety of factors, such as type of intervention and study population characteristics. While some studies demonstrated the effectiveness of certain intervention programs, the cost effectiveness and long-term sustainability of these programs remain questionable. When adopting an intervention program, it is important to consider the impacts of social-and cultural factors specific to the Asian population on cancer screening uptake. Future research is needed to develop new interventions and tools, and adopt vigorous study design and evaluation methodologies to increase cancer screening among Asian women to promote population health and health equity. PMID:22676147
Lu, Mingshan; Moritz, Sabina; Lorenzetti, Diane; Sykes, Lindsay; Straus, Sharon; Quan, Hude
2012-06-07
The Asian population is one of the fastest growing ethnic minority groups in western countries. However, cancer screening uptake is consistently lower in this group than in the native-born populations. As a first step towards developing an effective cancer screening intervention program targeting Asian women, we conducted a comprehensive systematic review, without geographic, language or date limitations, to update current knowledge on the effectiveness of existing intervention strategies to enhance breast and cervical screening uptake in Asian women. This study systematically reviewed studies published as of January 2010 to synthesize knowledge about effectiveness of cancer screening interventions targeting Asian women. Fifteen multidisciplinary peer-reviewed and grey literature databases were searched to identify relevant studies. The results of our systematic review were reported in accordance with the PRISMA Statement. Of 37 selected intervention studies, only 18 studies included valid outcome measures (i.e. self-reported or recorded receipt of mammograms or Pap smear). 11 of the 18 intervention studies with valid outcome measures used multiple intervention strategies to target individuals in a specific Asian ethnic group. This observed pattern of intervention design supports the hypothesis that employing a combination of multiple strategies is more likely to be successful than single interventions. The effectiveness of community-based or workplace-based group education programs increases when additional supports, such as assistance in scheduling/attending screening and mobile screening services are provided. Combining cultural awareness training for health care professionals with outreach workers who can help healthcare professionals overcome language and cultural barriers is likely to improve cancer screening uptake. Media campaigns and mailed culturally sensitive print materials alone may be ineffective in increasing screening uptake. Intervention effectiveness appears to vary with ethnic population, methods of program delivery, and study setting. Despite some limitations, our review has demonstrated that the effectiveness of existing interventions to promote breast and cervical cancer screening uptake in Asian women may hinge on a variety of factors, such as type of intervention and study population characteristics. While some studies demonstrated the effectiveness of certain intervention programs, the cost effectiveness and long-term sustainability of these programs remain questionable. When adopting an intervention program, it is important to consider the impacts of social-and cultural factors specific to the Asian population on cancer screening uptake. Future research is needed to develop new interventions and tools, and adopt vigorous study design and evaluation methodologies to increase cancer screening among Asian women to promote population health and health equity.
Decline of recent seabirds inferred from a composite 1000-year record of population dynamics
Xu, Liqiang; Liu, Xiaodong; Wu, Libin; Sun, Liguang; Zhao, Jinjun; Chen, Lin
2016-01-01
Based on three ornithogenic sediment profiles and seabird subfossils therein from the Xisha Islands, South China Sea, the relative population size of seabirds over the past 1000 years was reconstructed using reflectance spectrum. Here we present an apparent increase and subsequent decline of seabirds on these islands in the South China Sea. Seabird populations peaked during the Little Ice Age (LIA, 1400–1850 AD), implying that the cool climate during the LIA appears to have been more favorable to seabirds on the Xisha Islands in the South China Sea. Climate change partly explains the recent decrease in seabird populations over the past 150 years, but the significant decline and almost complete disappearance thereof on most of the Xisha Islands is probably attributable to human disturbance. Our study reveals the increasing impact of anthropogenic activities on seabird population in recent times. PMID:27748366
Lankau, Richard A; Strauss, Sharon Y
2011-01-01
Environmental management typically seeks to increase or maintain the population sizes of desirable species and to decrease population sizes of undesirable pests, pathogens, or invaders. With changes in population size come long-recognized changes in ecological processes that act in a density-dependent fashion. While the ecological effects of density dependence have been well studied, the evolutionary effects of changes in population size, via changes in ecological interactions with community members, are underappreciated. Here, we provide examples of changing selective pressures on, or evolution in, species as a result of changes in either density of conspecifics or changes in the frequency of heterospecific versus conspecific interactions. We also discuss the management implications of such evolutionary responses in species that have experienced rapid increases or decreases in density caused by human actions. PMID:25567977
Cheating, trade-offs and the evolution of aggressiveness in a natural pathogen population
Barrett, Luke; Bell, Thomas; Dwyer, Greg; Bergelson, Joy
2011-01-01
The evolutionary dynamics of pathogens are critically important for disease outcomes, prevalence and emergence. In this study we investigate ecological conditions that may promote the long-term maintenance of virulence polymorphisms in pathogen populations. Recent theory predicts that evolution towards increased virulence can be reversed if less aggressive social ‘cheats’ exploit more aggressive ‘cooperator’ pathogens. However, there is no evidence that social exploitation operates within natural pathogen populations. We show that for the bacterium Pseudomonas syringae, major polymorphisms for pathogenicity are maintained at unexpectedly high frequencies in populations infecting the host Arabidopsis thaliana. Experiments reveal that less aggressive strains substantially increase their growth potential in mixed infections and have a fitness advantage in non-host environments. These results suggest that niche differentiation can contribute to the maintenance of virulence polymorphisms, and that both within-host and between-host growth rates modulate cheating and cooperation in P. syringae populations. PMID:21951910
A population-based longitudinal study on the implications of demographics on future blood supply.
Greinacher, Andreas; Weitmann, Kerstin; Lebsa, Anne; Alpen, Ulf; Gloger, Doris; Stangenberg, Wolfgang; Kiefel, Volker; Hoffmann, Wolfgang
2016-12-01
Changes in demographics with increases in older age groups and decreases in younger age groups imply an increased demand for blood transfusions paralleled by a decrease in the population eligible for blood donation. However, more restrictive transfusion triggers and the patient blood management initiative also reduce the demand for red blood cells (RBCs). Eastern Germany is a model region for the impact of demographic changes, which manifest in this region approximately 10 years earlier than in other regions due to the 50% birth rate decline after 1989. We report the 2010 longitudinal 5-year follow-up of the study assessing all whole blood donations and RBC transfusions in Mecklenburg-West Pomerania. We compared the projections that were made 5 years ago with: 1) the current age structure of the blood donor and transfusion recipient populations and 2) its impact on blood demand and blood donation numbers in specific age groups. Transfusion rates were lower and blood donation rates were higher than predicted in 2005. Although transfusion rates/1000 decreased in nearly all age groups, the overall annual transfusion rate increased to 66.4 RBC units/1000 (in 2005, 62.2/1000) due to the absolute increase in the elderly population. Despite a 7.4% decline in the population 18 to 65 years of age, whole blood donations increased by 11.7% between 2005 and 2010, but thereafter decreased by 21% (first-time donors by 39.4%), reflecting the effect of the post-1990 birth rate decline on the donor population. Changes in demography and medical practice impact the delicate balance between available blood supply and potential future transfusion needs. In times of pronounced demographic changes, regular monitoring of the blood demand and age structure of blood recipients and donors is required to allow strategic planning to prevent blood shortages or overproduction. © 2016 AABB.
Chronic kidney disease in Polish elderly population aged 75+: results of the WOBASZ Senior Survey.
Zdrojewski, Łukasz; Król, Ewa; Rutkowski, Bolesław; Piotrowski, Walerian; Pająk, Andrzej; Drygas, Wojciech; Zdrojewski, Tomasz
2017-04-01
Kidney filtration decreases with age, which results in an increased frequency of chronic kidney disease (CKD) in the elderly population. The purpose of the study was to assess the prevalence and epidemiology of CKD in the Polish elderly population. A representative sample of the Polish elderly population, composed of 918 people (F 452, M 466) in the age of ≥75 years, was chosen. All participants had their history, anthropometric measures and biochemical parameters (creatinine, fasting glucose, complete cholesterol) evaluated. CKD was diagnosed when eGFR was <60 ml/min/1.73 m 2 . The comorbidities, anthropometric and social factors connected with the onset of CKD were also analyzed. The prevalence of CKD in the analyzed population was 26.9% (F 32.0%, M 15.8%), which gives an estimated number of 495,590 (95% CI 396,363-594,817) patients in the study subpopulation. The majority of these people were in the G3A category-70.1%, while the remaining fell under the G3B-25.7%, G4-3.1% and G5-1.1% categories. Disease awareness among the participants was found to be at 17%. Arterial hypertension (AH) was more frequent in people with CKD (91.0 vs. 80.3%, P < 0.001), whereas diabetes mellitus (DM) prevalence was comparable in both CKD and non-CKD groups (11.7 vs. 11.4%, ns). In the examined group, DM had no influence on the frequency of CKD. In contrast, the presence of cardiovascular diseases substantially increased the chances of developing CKD (OR 1.87, P < 0.05). 1. The prevalence of CKD in the Polish elderly population was 26.9%. 2. Awareness of CKD is low. 3. DM, increasing age and AH did not increase the risk of CKD. 4. Coexistence of cardiovascular diseases increased the risk of having CKD.
Population-dependent effects of ocean acidification.
Wood, Hannah L; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P
2016-04-13
Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica.The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. © 2016 The Author(s).
Population-dependent effects of ocean acidification
Wood, Hannah L.; Sundell, Kristina; Almroth, Bethanie Carney; Sköld, Helén Nilsson; Eriksson, Susanne P.
2016-01-01
Elevated carbon dioxide levels and the resultant ocean acidification (OA) are changing the abiotic conditions of the oceans at a greater rate than ever before and placing pressure on marine species. Understanding the response of marine fauna to this change is critical for understanding the effects of OA. Population-level variation in OA tolerance is highly relevant and important in the determination of ecosystem resilience and persistence, but has received little focus to date. In this study, whether OA has the same biological consequences in high-salinity-acclimated population versus a low-salinity-acclimated population of the same species was investigated in the marine isopod Idotea balthica. The populations were found to have physiologically different responses to OA. While survival rate was similar between the two study populations at a future CO2 level of 1000 ppm, and both populations showed increased oxidative stress, the metabolic rate and osmoregulatory activity differed significantly between the two populations. The results of this study demonstrate that the physiological response to OA of populations from different salinities can vary. Population-level variation and the environment provenance of individuals used in OA experiments should be taken into account for the evaluation and prediction of climate change effects. PMID:27053741
ERIC Educational Resources Information Center
Kirby, A.; Woodward, A.; Jackson, S.; Wang, Y.; Crawford, M. A.
2010-01-01
Despite the increased interest in the effects of omega-3 supplementation on childrens' learning and behaviour, there are a lack of controlled studies of this kind that have utilised a typically developing population. This study investigated the effects of omega-3 supplementation in 450 children aged 8-10 years old from a mainstream school…
Proper Antibiotic Use in a Home-Based Primary Care Population Treated for Urinary Tract Infections.
Gee, Megan E; Ford, James; Conway, Erin L; Ott, Michael C; Sellick, John A; Mergenhagen, Kari A
2018-02-01
To evaluate the trends associated with diagnosis and treatment of urinary tract infections (UTI) in a home-based primary care population of Veterans Health System patients from 2006 to 2015. Retrospective cohort study. Veterans Healthcare System. Home-based primary care patients treated for UTI from 2006 to 2015. None. Appropriate therapy was determined based on the McGeer criteria. Multivariate logistic regression was used to determine factors leading to appropriate UTI treatment. Of 366 available patients, 68 (18.6%) were tested for a UTI. Appropriate therapy occurred in 26% of patients. Allergy to any antibiotic increased the odds of appropriate treatment (odds ratio [OR] = 5.6, 95% confidence interval [CI] 1.5-23.2). Flank pain and increased urinary frequency also increased the likelihood of being treated appropriately (OR = 25.9, 95% CI 2.9-584.0 and OR = 4.49, 95% CI 0.99-21.2, respectively). Antibiotics were overused for treating UTIs in the homebound population. Patients with flank pain, increased urinary frequency, and antibiotic allergy were more likely to receive appropriate treatment. Pharmacists, therefore, have a viable opportunity to increase appropriate antibiotic prescribing in the home-based primary care population.
Assessment of facial golden proportions among central Indian population.
Saurabh, Rathore; Piyush, Bolya; Sourabh, Bhatt; Preeti, Ojha; Trivedi, Rutvik; Vishnoi, Pradeep
2016-12-01
This study aimed to identify and establish the facial and smile proportions in young adults and to compare the results with ideal or divine proportions, compare the proportions of males and females included in our study population and compare them with those established for Caucasian and Japanese populations. Two hundred participants (164 females, 36 males) with Angle's class I malocclusion (M.O). and well-balanced faces were selected and photographed in the frontal repose position. Analysis was done in Adobe Photoshop software. Statistical analysis was done using the Statistical Package for the Social Sciences version 17.0. (IBM Corporation Armonk, New York, United States). Results suggested that females are more near to ideal ratios and males are more deviated from the ideal ratios. The proportions of males and females were not considerably different from each other. In Indian population, upper 3 rd facial height (TR-LC) was increased and mid-face height (LC-LN) was decreased; in lower 3 rd of the face, LN-CH was slightly increased in comparison to CH-ME. In facial widths, outer canthal width (LC-LC) was greater in the Indian population and mouth width (CH-CH) was normal. When compared with Indian population, Japanese participants had wider noses, outer canthal distance, and bitemporal width. It was concluded that significant difference was found between the proportions of the Indian population and ideal ratio. When Indian population was compared with Japanese and Caucasian populations, some parameters of facial proportions showed significant difference, which leads to the need for establishing standardized norms for various facial proportions in Indian population.
Efremov, V V
2005-05-01
The effect of subdivision on the effective size (Ne) of the early-run sockeye salmon Oncorhynchus nerka population of Lake Azabach'e (Kamchatka Peninsula) has been studied. The mode of this effect is determined by the relative productivity of the subpopulations and its magnitude, by the rate of individual migration among subpopulations and genetic differentiation. If the contributions of subpopulations (offspring numbers) are different, genetic differentiation can reduce the Ne of the subdivided population. At equal subpopulation contributions, genetic differentiation always increases the Ne of the subdivided population in comparison with a panmictic population. We have found that all sockeye salmon subpopulations of Azabach'e Lake produce equal offspring numbers contributing to the next generation. The genetic differentiation between sockeye salmon subpopulations is low, and the subdivision increases the Ne of the early-run race with reference to the sum of the effective sizes of the subpopulations by as little as 2%.
Tachmazidou, Ioanna; Dedoussis, George; Southam, Lorraine; Farmaki, Aliki-Eleni; Ritchie, Graham R. S.; Xifara, Dionysia K.; Matchan, Angela; Hatzikotoulas, Konstantinos; Rayner, Nigel W.; Chen, Yuan; Pollin, Toni I.; O’Connell, Jeffrey R.; Yerges-Armstrong, Laura M.; Kiagiadaki, Chrysoula; Panoutsopoulou, Kalliope; Schwartzentruber, Jeremy; Moutsianas, Loukas; Tsafantakis, Emmanouil; Tyler-Smith, Chris; McVean, Gil; Xue, Yali; Zeggini, Eleftheria
2013-01-01
Isolated populations can empower the identification of rare variation associated with complex traits through next generation association studies, but the generalizability of such findings remains unknown. Here we genotype 1,267 individuals from a Greek population isolate on the Illumina HumanExome Beadchip, in search of functional coding variants associated with lipids traits. We find genome-wide significant evidence for association between R19X, a functional variant in APOC3, with increased high-density lipoprotein and decreased triglycerides levels. Approximately 3.8% of individuals are heterozygous for this cardioprotective variant, which was previously thought to be private to the Amish founder population. R19X is rare (<0.05% frequency) in outbred European populations. The increased frequency of R19X enables discovery of this lipid traits signal at genome-wide significance in a small sample size. This work exemplifies the value of isolated populations in successfully detecting transferable rare variant associations of high medical relevance. PMID:24343240
Tachmazidou, Ioanna; Dedoussis, George; Southam, Lorraine; Farmaki, Aliki-Eleni; Ritchie, Graham R S; Xifara, Dionysia K; Matchan, Angela; Hatzikotoulas, Konstantinos; Rayner, Nigel W; Chen, Yuan; Pollin, Toni I; O'Connell, Jeffrey R; Yerges-Armstrong, Laura M; Kiagiadaki, Chrysoula; Panoutsopoulou, Kalliope; Schwartzentruber, Jeremy; Moutsianas, Loukas; Tsafantakis, Emmanouil; Tyler-Smith, Chris; McVean, Gil; Xue, Yali; Zeggini, Eleftheria
2013-01-01
Isolated populations can empower the identification of rare variation associated with complex traits through next generation association studies, but the generalizability of such findings remains unknown. Here we genotype 1,267 individuals from a Greek population isolate on the Illumina HumanExome Beadchip, in search of functional coding variants associated with lipids traits. We find genome-wide significant evidence for association between R19X, a functional variant in APOC3, with increased high-density lipoprotein and decreased triglycerides levels. Approximately 3.8% of individuals are heterozygous for this cardioprotective variant, which was previously thought to be private to the Amish founder population. R19X is rare (<0.05% frequency) in outbred European populations. The increased frequency of R19X enables discovery of this lipid traits signal at genome-wide significance in a small sample size. This work exemplifies the value of isolated populations in successfully detecting transferable rare variant associations of high medical relevance.
Taiwan's population and family planning efforts: an historical perspective.
Cernada, G; Sun, T H; Chang, M C; Tsai, J F
The unprecedented decline of Taiwan's natural population increase rate from 3% in 1963 to 1.9% in 1973, attributed primarily to an increasing use of contraception, brought universal attention to one of the first and most successful national family planning programs, at a time when successes were few. Taiwan met its goal of decreasing its natural increase rate despite its young population, increasing numbers of women of childbearing ages, a strong preference for sons and a per capita income at the outset in 1963 of less than U.S.$200. Recognition of this achievement brought thousands of professionals, particularly from developing countries, to study the program firsthand: more than 3,000 during 1970--73 alone. This was matched by an avalanche of publications about the program that appeared around the world, written by practitioners, academics and others. This article tells the story of this success.
White-tailed deer population dynamics and adult female survival in the presence of a novel predator
Michael C. Chitwood; Marcus A. Lashley; John C. Kilgo; Christopher E. Moorman; Christopher S. Deperno
2015-01-01
Recent localized declines in white-tailed deer (Odocoileus virginianus) populations in the southeastern United States have been linked to increasing predation pressure from coyotes (Canis latrans), a novel predator to the region. Studies have documented coyotes as the leading cause of mortality for neonates, and 1 study documented coyotes as a mortality factor for...
Federal Register 2010, 2011, 2012, 2013, 2014
2011-08-09
... Nutrition Assistance Program Participation Among Medicare's Extra Help Population Pilot Projects AGENCY... Participation Among Medicare's Extra Help Population Pilot Projects. DATES: Written comments must be received on... Efforts to Increase Supplemental Nutrition Assistance Program Participation Among Medicare's Extra Help...
The geography of spatial synchrony
Jonathan A. Walter; Lawrence W. Sheppard; Thomas L. Anderson; Jude H. Kastens; Ottar N. Bjørnstad; Andrew M. Liebhold; Daniel C. Reuman; Bernd Blasius
2017-01-01
Spatial synchrony, defined as correlated temporal fluctuations among populations, is a fundamental feature of population dynamics, but many aspects of synchrony remain poorly understood. Few studies have examined detailed geographical patterns of synchrony; instead most focus on how synchrony declines with increasing linear distance between locations, making the...
ASSESSING EXPOSURES TO MOBILE SOURCE AIR TOXIC EMISSIONS FOR POPULATIONS LIVING NEAR ROADWAYS
A growing number of epidemiological studies have identified an increase in occurrence of adverse health effects for populations living near major roads. However, the biological mechanism(s) leading to the adverse effects have not been identified. Limitations in exposure assessm...
Human Papillomavirus Vaccination at a Time of Changing Sexual Behavior
Lazzarato, Fulvio; Brisson, Marc; Franceschi, Silvia
2016-01-01
Human papillomavirus (HPV) prevalence varies widely worldwide. We used a transmission model to show links between age-specific sexual patterns and HPV vaccination effectiveness. We considered rural India and the United States as examples of 2 heterosexual populations with traditional age-specific sexual behavior and gender-similar age-specific sexual behavior, respectively. We simulated these populations by using age-specific rates of sexual activity and age differences between sexual partners and found that transitions from traditional to gender-similar sexual behavior in women <35 years of age can result in increased (2.6-fold in our study) HPV16 prevalence. Our model shows that reductions in HPV16 prevalence are larger if vaccination occurs in populations before transitions in sexual behavior and that increased risk for HPV infection attributable to transition is preventable by early vaccination. Our study highlights the importance of using time-limited opportunities to introduce HPV vaccination in traditional populations before changes in age-specific sexual patterns occur. PMID:26691673
The Rate of Sepsis in a National Pediatric Population, 2006 to 2012.
Schuller, Kristin A; Hsu, Benson S; Thompson, Allyson B
2017-10-01
The rate of pediatric severe sepsis is reported to be on the rise in the United States, increasing by approximately 6000 cases annually. The goal of this study was to determine the rate of pediatric sepsis per 100 000 inpatient discharges over time. The 2006, 2009, and 2012 Agency for Healthcare Research and Quality Healthcare Cost Utilization Project Kid's Inpatient Databases were used to analyze the rate of sepsis in children over time. The rate of pediatric sepsis has increased over time from 92.8 per 100 000 in 2006 to 158.7 per 100 000 in 2012. Children less than a year old with Medicaid coverage and 3 or more procedures during hospitalization have significantly higher rates than their counterparts. This study helps clarify the population demographics that are at greater risk for sepsis infections. Understanding the at-risk population aids policymakers and care providers in targeting these populations and make drastic changes to sepsis policies.
van Manen, Frank T.; Ebinger, Michael R.; Haroldson, Mark A.; Harris, Richard B.; Higgs, Megan D.; Cherry, Steve; White, Gary C.; Schwartz, Charles C.
2014-01-01
Doak and Cutler critiqued methods used by the Interagency Grizzly Bear Study Team (IGBST) to estimate grizzly bear population size and trend in the Greater Yellowstone Ecosystem. Here, we focus on the premise, implementation, and interpretation of simulations they used to support their arguments. They argued that population increases documented by IGBST based on females with cubs-of-the-year were an artifact of increased search effort. However, we demonstrate their simulations were neither reflective of the true observation process nor did their results provide statistical support for their conclusion. They further argued that survival and reproductive senescence should be incorporated into population projections, but we demonstrate their choice of extreme mortality risk beyond age 20 and incompatible baseline fecundity led to erroneous conclusions. The conclusions of Doak and Cutler are unsubstantiated when placed within the context of a thorough understanding of the data, study system, and previous research findings and publications.
Human Papillomavirus Vaccination at a Time of Changing Sexual Behavior.
Baussano, Iacopo; Lazzarato, Fulvio; Brisson, Marc; Franceschi, Silvia
2016-01-01
Human papillomavirus (HPV) prevalence varies widely worldwide. We used a transmission model to show links between age-specific sexual patterns and HPV vaccination effectiveness. We considered rural India and the United States as examples of 2 heterosexual populations with traditional age-specific sexual behavior and gender-similar age-specific sexual behavior, respectively. We simulated these populations by using age-specific rates of sexual activity and age differences between sexual partners and found that transitions from traditional to gender-similar sexual behavior in women <35 years of age can result in increased (2.6-fold in our study) HPV16 prevalence. Our model shows that reductions in HPV16 prevalence are larger if vaccination occurs in populations before transitions in sexual behavior and that increased risk for HPV infection attributable to transition is preventable by early vaccination. Our study highlights the importance of using time-limited opportunities to introduce HPV vaccination in traditional populations before changes in age-specific sexual patterns occur.
Getting Under the Hood: How and for Whom Does Increasing Course Structure Work?
Eddy, Sarah L.
2014-01-01
At the college level, the effectiveness of active-learning interventions is typically measured at the broadest scales: the achievement or retention of all students in a course. Coarse-grained measures like these cannot inform instructors about an intervention's relative effectiveness for the different student populations in their classrooms or about the proximate factors responsible for the observed changes in student achievement. In this study, we disaggregate student data by racial/ethnic groups and first-generation status to identify whether a particular intervention—increased course structure—works better for particular populations of students. We also explore possible factors that may mediate the observed changes in student achievement. We found that a “moderate-structure” intervention increased course performance for all student populations, but worked disproportionately well for black students—halving the black–white achievement gap—and first-generation students—closing the achievement gap with continuing-generation students. We also found that students consistently reported completing the assigned readings more frequently, spending more time studying for class, and feeling an increased sense of community in the moderate-structure course. These changes imply that increased course structure improves student achievement at least partially through increasing student use of distributed learning and creating a more interdependent classroom community. PMID:25185229
Eakin, Elizabeth G; Bull, Sheana S; Glasgow, Russell E; Mason, Mondi
2002-01-01
There has been increased recognition of the importance of developing diabetes self-management education (DSME) interventions that are effective with under-served and minority populations. Despite several recent studies in this area, there is to our knowledge no systematic review or synthesis of what has been learned from this research. An electronic literature search identified five formative evaluations and ten controlled DSME intervention trials focused on under-served (low-income, minority or aged) populations. The RE-AIM (Reach, Efficacy, Adoption, Implementation, Maintenance) evaluation framework was used to evaluate the controlled studies on the dimensions of reach, efficacy, adoption, implementation, and maintenance. Fifty percent of the studies identified reported on the percentage of patients who participated, and the percentages were highly variable. The methodological quality of the articles was generally good and the short-term results were encouraging, especially on behavioral outcomes. Data on adoption (representativeness of settings and clinicians who participate) and implementation were almost never reported. Studies of modalities in addition to group meetings are needed to increase the reach of DSME with under-served populations. The promising formative evaluation work that has been conducted needs to be extended for more systematic study of the process of intervention implementation and adaptation with special populations. Studies that explicitly address the community context and that address multiple issues related to public health impact of DSME interventions are recommended to enhance long-term results. Copyright 2002 John Wiley & Sons, Ltd.
Chromosome 9p21 In Ischemic Stroke: Population Structure and Meta-Analysis
Anderson, CD; Biffi, A; Rost, NS; Cortellini, L; Furie, KL; Rosand, J
2011-01-01
Background and Purpose Sequence variants on chromosome 9p21.3 are implicated in coronary artery disease (CAD) and myocardial infarction (MI), but studies in ischemic stroke have produced inconsistent results. We investigated whether these conflicting findings were due to false positive studies confounded by population stratification, or false negative studies that failed to account for effects specific to certain stroke subtypes. Methods After assessing for population stratification at 9p21.3 using genome-wide data, we meta-analyzed 8 ischemic stroke studies. This analysis focused on two single nucleotide polymorphisms (SNPs), rs1537378 and rs10757278, as these variants are in strong linkage disequilibrium with most SNPs analyzed in prior studies of the region. Results Principal component analysis of the genome-wide data showed no evidence of population stratification at that locus. Meta-analysis confirmed that both rs1537378 and rs10757278 are risk factors for ischemic stroke (odds ratios 1.09, [p = 0.0014], and 1.11, [p = 0.001] respectively). Subtype analysis revealed a substantial increase in the effect of each SNP for risk of large artery (LA) stroke, achieving an effect size similar to that seen in CAD/MI. Conclusions Variants on 9p21.3 are associated with ischemic stroke, and restriction of analysis to LA stroke increases effect size towards that observed in prior association studies of CAD/MI. Previous inconsistent findings are best explained by this subtype-specificity rather than any unmeasured confounding by population stratification. PMID:20395606
Whiting, James R; Magalhaes, Isabel S; Singkam, Abdul R; Robertson, Shaun; D'Agostino, Daniele; Bradley, Janette E; MacColl, Andrew D C
2018-06-20
Understanding how wild immune variation covaries with other traits can reveal how costs and trade-offs shape immune evolution in the wild. Divergent life history strategies may increase or alleviate immune costs, helping shape immune variation in a consistent, testable way. Contrasting hypotheses suggest that shorter life histories may alleviate costs by offsetting them against increased mortality; or increase the effect of costs if immune responses are traded off against development or reproduction. We investigated the evolutionary relationship between life history and immune responses within an island radiation of three-spined stickleback, with discrete populations of varying life histories and parasitism. We sampled two short-lived, two long-lived and an anadromous population using qPCR to quantify current immune profile and RAD-seq data to study the distribution of immune variants within our assay genes and across the genome. Short-lived populations exhibited significantly increased expression of all assay genes, which was accompanied by a strong association with population-level variation in local alleles and divergence in a gene that may be involved in complement pathways. In addition, divergence around the eda gene in anadromous fish is likely associated with increased inflammation. A wider analysis of 15 populations across the island revealed that immune genes across the genome show evidence of having diverged alongside life history strategies. Parasitism and reproductive investment were also important sources of variation for expression, highlighting the caution required when assaying immune responses in the wild. These results provide strong, gene-based support for current hypotheses linking life history and immune variation across multiple populations of a vertebrate model. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
Terry, Anna R; Jordan, Justin T; Schwamm, Lee; Plotkin, Scott R
2016-01-01
Although neurofibromatosis type 1 (NF1) may be associated with an incompletely understood vasculopathy, relative odds of stroke in this population is not known. Using the 1998 to 2009 US Nationwide Inpatient Sample, we performed a case-control study matching cases of NF1 to controls without such a diagnosis. We then compared the odds of stroke between the 2 groups. We used multivariable logistic regression to adjust for known or suspected confounders. NF1 was associated with younger mean age at the time of stroke (41 versus 48) and a lower prevalence of stroke risk factors among adult patients. Pediatric patients with NF1, however, were more likely to have hypertension. Patients with NF1 were significantly more likely to be diagnosed with any stroke (odds ratio, 1.2; P<0.0001) than the general population. The odds of intracerebral hemorrhage were greatest among hemorrhagic stroke types analyzed (odds ratio, 1.9; P<0.0001). In the pediatric NF1 population, the odds of intracerebral hemorrhage were more dramatically elevated (odds ratio, 8.1; P<0.0001). The odds of ischemic stroke were also increased with NF1 in the pediatric (odds ratio, 3.4; P<0.0001) but not in the adult population. When compared with the general population, the odds of any type of stroke are significantly increased for patients with NF1, both adult and pediatric. This risk is most notable for hemorrhagic strokes although it is also increased for ischemic strokes in children. Physicians should be aware of the increased risk of stroke in this population, and consider stroke as a potential cause of new neurological symptoms. © 2015 American Heart Association, Inc.
Hatahet, W; Khosla, P; Fungwe, T V
2002-07-01
Although significant advances have been made in the area of cardiovascular disease, few studies have targeted ethnic groups. There is a large and growing Arab-American (AA) population living in Southeast Michigan, whose risk of cardiovascular disease may be on the increase. The objective of this study was to evaluate the prevalence of cardiovascular disease risk factors and associated behavioral factors in an AA community with a large population of emigrants, subjected to significant lifestyle changes. Three hundred and fifty-two AA living in Southeast Michigan, mostly from the Middle East, were screened to determine their eating and smoking habits, body mass index (BMI) body fat analysis, blood pressure, and complete lipid profiling. Overweight was defined as a BMI greater than or equal to the 85th percentile value for age- and sex-specific reference data from the third National Health and Nutrition Examination Survey (NHANES III). Correlation analysis was used to examine factors associated with being overweight, with adjustment for age and sex. Blood cholesterol concentrations were compared with published data for Arabs from the Middle Eastern countries. The overall prevalence of being overweight in subjects aged 35 and older was significantly higher than NHANES III reference data (Men, 27.7% (95% confidence interval, 21.8-34.5); women, 33.7% (95% confidence interval, 27.9-40.1)). A mean cholesterol concentration of 210 +/- 4 mg/dl was observed in those over the age of 40. The mean high-density lipoprotein (HDL)-cholesterol levels for men and women were 38 and 48 mg/dl, respectively. Greater than 54.6% of all subjects had a total cholesterol:HDL ratio > 4.5. Although being overweight and obesity were prevalent in this population, the mean BMI for men was 25.7 +/- 0.34, compared with 27 +/- 0.58 for women. Increased BMI was significantly correlated (P < 0.01) with increased blood pressure, increased glucose levels, increased total cholesterol and decreased HDL-cholesterol levels (P < 0.01). Elevation in risk factors to cardiovascular disease is prevalent in this population and indicates a need for programs targeting primary prevention of obesity in men and women. These results, which could be attributed in part to lifestyle changes typical of most emigrant populations, suggest an increase in the risk for developing cardiovascular disease. In addition, this study provides a basis for future intervention to improve the health of this population.
Burkett, Ellen; Martin-Khan, Melinda G; Scott, Justin; Samanta, Mayukh; Gray, Leonard C
2017-07-01
Objectives The aim of the present study was to describe trends in and age and gender distributions of presentations of older people to Australian emergency departments (EDs) from July 2006 to June 2011, and to develop ED utilisation projections to 2050. Methods A retrospective analysis of data collected in the National Non-admitted Patient Emergency Department Care Database was undertaken to assess trends in ED presentations. Three standard Australian Bureau of Statistics population growth models, with and without adjustment for current trends in ED presentation growth and effects of climate change, were examined with projections of ED presentations across three age groups (0-64, 65-84 and ≥85 years) to 2050. Results From 2006-07 to 2010-11, ED presentations increased by 12.63%, whereas the Australian population over this time increased by only 7.26%. Rates of presentation per head of population were greatest among those aged ≥85 years. Projections of ED presentations to 2050 revealed that overall ED presentations are forecast to increase markedly, with the rate of increase being most marked for older people. Conclusion Growth in Australian ED presentations from 2006-07 to 2010-11 was greater than that expected from population growth alone. The predicted changes in demand for ED care will only be able to be optimally managed if Australian health policy, ED funding instruments and ED models of care are adjusted to take into account the specific care and resource needs of older people. What is known about the topic? Rapid population aging is anticipated over coming decades. International studies and specific local-level Australian studies have demonstrated significant growth in ED presentations. There have been no prior national-level Australian studies of ED presentation trends by age group. What does this paper add? The present study examined national ED presentation trends from July 2006 to June 2011, with specific emphasis on trends in presentation by age group. ED presentation growth was found to exceed population growth in all age groups. The rate of ED presentations per head of population was highest among those aged ≥85 years. ED utilisation projections to 2050, using standard Australian Bureau of Statistics population modelling, with and without adjustment for current ED growth, were developed. The projections demonstrated linear growth in ED presentation for those aged 0-84 years, with growth in ED presentations of the ≥85 year age group demonstrating marked acceleration after 2030. What are the implications for practitioners? Growth in ED presentations exceeding population growth suggests that current models of acute health care delivery require review to ensure that optimal care is delivered in the most fiscally efficient manner. Trends in presentation of older people emphasise the imperative for ED workforce planning and education in care of this complex patient cohort, and the requirement to review funding models to incentivise investment in ED avoidance and substitutive care models targeting older people.
Lewinson, Ryan T; Vallerand, Isabelle A; Parsons, Laurie M; LaMothe, Jeremy M; Frolkis, Alexandra D; Lowerison, Mark W; Kaplan, Gilaad G; Patten, Scott B; Barnabe, Cheryl
2018-01-01
Objectives Imaging studies in patients with cutaneous psoriasis have demonstrated asymptomatic bone and tendon changes, commonly of the foot and ankle. We sought to determine if patients with cutaneous psoriasis have an increased risk of clinically significant foot and ankle tendinopathy or enthesopathy compared with the general population. Methods Patients with cutaneous psoriasis and a general population cohort were identified in The Health Improvement Network, a general practice medical records database from the UK. All patients with psoriatic arthritis were excluded. Cox proportional-hazards models (α=0.05) estimated the HR for development of foot and ankle tendinopathy or enthesopathy among patients with psoriasis, with adjustment for numerous covariates. Results In total, 78 630 patients with cutaneous psoriasis and 5 983 338 persons from the general population were identified. In an unadjusted model, patients with cutaneous psoriasis had a 25% increased risk of developing foot and ankle tendinopathy or enthesopathy compared with the general population (HR 1.25, 95% CI 1.20 to 1.30, p<0.0001). The HR remained unchanged and statistically significant after adjusting for covariates, and in sensitivity analyses. Conclusions These data suggest that patients with psoriasis can have foot and ankle tendinopathy or enthesopathy without having psoriatic arthritis, presenting a diagnostic challenge to physicians. Further research is needed to elucidate mechanisms contributing to this increased risk. PMID:29862046
Hensing, Gunnel; Andersson, Lena; Brage, Sören
2006-01-01
Background The aim of this study was to assess the incidence of sickness absence with psychiatric diagnoses from 1994–2000, and the distribution across gender, age groups, diagnostic groups and regions in a general population. Methods The population at risk was defined as all individuals aged 16–66 years who were entitled to sickness benefits in 1994, 1996, 1998 and 2000 (n = 2,282,761 in 2000). All individuals with a full-time disability pension were excluded. The study included approximately 77% of the Norwegian population aged 16–66 years. For each year, the study base started on 1 January and ended on 31 December. Individuals that were sick-listed for more than 14/16 consecutive days with a psychiatric diagnosis on their medical certificate were selected as cases. Included in this study were data for Norway, the capital city Oslo and five regions in the southeast of the country. Results Sickness absence with psychiatric diagnoses increased in all age groups, in women and men, and in all regions. At the national level, the cumulative incidence increased in women from 1.7% in 1994 to 4.6% in 2000, and in men from 0.8% in 1994 to 2.2% in 2000. The highest cumulative incidence was found in middle-aged women and men (30–59 years). Women had a higher incidence than men in all stratification groups. The cumulative incidences in 2000 varied between 4.6% to 5.6% in women in the different regions, and for men the corresponding figures were 2.1% to 3.2%. Throughout the four years studied, women in Oslo had more than twice as high incidence levels of sickness absence with alcohol and drug diagnoses as the country as a whole. There were some differences between regions in sickness absence with specific psychiatric diagnoses, but they were small and most comparisons were non-significant. Conclusion Sickness absence with psychiatric diagnoses increased between 1994 and 2000 in Norway. The increase was highest in the middle-aged, and in women. Few regional differences were found. That the increase pervaded all stratification groups supports general explanations of the increase, such as changes in attitudes to psychiatric disorders in both patients and doctors, and increased mental distress probably associated with societal changes at a more structural level. PMID:16923198
NASA Astrophysics Data System (ADS)
Rasmussen, K. L.; Prein, A. F.; Rasmussen, R. M.; Ikeda, K.; Liu, C.
2017-11-01
Novel high-resolution convection-permitting regional climate simulations over the US employing the pseudo-global warming approach are used to investigate changes in the convective population and thermodynamic environments in a future climate. Two continuous 13-year simulations were conducted using (1) ERA-Interim reanalysis and (2) ERA-Interim reanalysis plus a climate perturbation for the RCP8.5 scenario. The simulations adequately reproduce the observed precipitation diurnal cycle, indicating that they capture organized and propagating convection that most climate models cannot adequately represent. This study shows that weak to moderate convection will decrease and strong convection will increase in frequency in a future climate. Analysis of the thermodynamic environments supporting convection shows that both convective available potential energy (CAPE) and convective inhibition (CIN) increase downstream of the Rockies in a future climate. Previous studies suggest that CAPE will increase in a warming climate, however a corresponding increase in CIN acts as a balancing force to shift the convective population by suppressing weak to moderate convection and provides an environment where CAPE can build to extreme levels that may result in more frequent severe convection. An idealized investigation of fundamental changes in the thermodynamic environment was conducted by shifting a standard atmospheric profile by ± 5 °C. When temperature is increased, both CAPE and CIN increase in magnitude, while the opposite is true for decreased temperatures. Thus, even in the absence of synoptic and mesoscale variations, a warmer climate will provide more CAPE and CIN that will shift the convective population, likely impacting water and energy budgets on Earth.
Cortesi, Paolo A; Assietti, Roberto; Cuzzocrea, Fabrizio; Prestamburgo, Domenico; Pluderi, Mauro; Cozzolino, Paolo; Tito, Patrizia; Vanelli, Roberto; Cecconi, Davide; Borsa, Stefano; Cesana, Giancarlo; Mantovani, Lorenzo G
2017-09-15
Retrospective large population based-study. Assessment of the epidemiologic trends and economic burden of first spinal fusions. No adequate data are available regarding the epidemiology of spinal fusion surgery and its economic impact in Europe. The study population was identified through a data warehouse (DENALI), which matches clinical and economic data of different Healthcare Administrative databases of the Italian Lombardy Region. The study population consisted of all subjects, resident in Lombardy, who, during the period January 2001 to December 2010, underwent spinal fusion surgery (ICD-9-CM codes: 81.04, 81.05, 81.06, 81.07, and 81.08). The first procedure was used as the index event. We estimated the incidence of first spinal fusion surgery, the population and surgery characteristics and the healthcare costs from the National Health Service's perspective. The analysis was performed for the entire population and divided into the main groups of diagnosis. The analysis identified 17,772 [mean age (SD): 54.6 (14.5) years, 55.3% females] spinal fusion surgeries. Almost 67% of the patients suffered from a lumbar degenerative disease. The incidence rate of interventions increased from 11.5 to 18.5 per 100,000 person-year between 2001 and 2006, and was above 20.0 per 100,000 person-year in the last 4 years. The patients' mean age increased during the observational time period from 48.1 to 55.9 years; whereas the median hospital length of stay reported for the index event decreased. The average cost of the spinal fusion surgery increased during the observational period, from &OV0556; 4726 up to &OV0556; 9388. The study showed an increasing incidence of spinal fusion surgery and costs from 2001 to 2010. These results can be used to better understand the epidemiological and economic burden of these interventions, and help to optimize the resources available considering the different clinical approaches accessible today. 4.
Immigrants’ duration of residence and adverse birth outcomes: a population-based study
Urquia, ML; Frank, JW; Moineddin, R; Glazier, RH
2010-01-01
Please cite this paper as: Urquia M, Frank J, Moineddin R, Glazier R. Immigrants’ duration of residence and adverse birth outcomes: a population-based study. BJOG 2010;117:591–601. Objective This study aimed to examine preterm and small-for-gestational-age (SGA) births among immigrants, by duration of residence, and to compare them with the Canadian-born population. Design Population-based cross-sectional study with retrospective assessment of immigration. Setting Metropolitan areas of Ontario, Canada. Population A total of 83 233 singleton newborns born to immigrant mothers and 314 237 newborns born to non-immigrant mothers. Methods We linked a database of immigrants acquiring permanent residence in Ontario, Canada, in the period 1985–2000 with mother–infant hospital records (2002–2007). Duration of residence was measured as completed years from arrival to Canada to delivery/birth. Logistic regression models were used to estimate the effects of duration of residence with adjusted odds ratios and 95% confidence intervals. In analyses restricted to immigrants only, hierarchical models were used to account for the clustering of births into maternal countries of birth. Main outcome measures Preterm birth (PTB) and SGA birth. Results Recent immigrants (<5 years) had a lower risk of PTB (4.7%) than non-immigrants (6.2%), but those with ≥15 years of stay were at higher risk (7.4%). Among immigrants, a 5-year increase in Canadian residence was associated with an increase in PTB (AOR 1.14, 95% CI 1.10–1.19), but not in SGA birth (AOR 0.99, 95% CI 0.96–1.02). Conclusions Time since migration was associated with increases in the risk of PTB, but was not associated with an increase in SGA births. Ignoring duration of residence may mask important disparities in preterm delivery between immigrants and non-immigrants, and between immigrant subgroups categorised by their duration of residence. PMID:20374596
Wang, Lijuan; Feng, Liangshu; Yao, Yan; Wang, Yuzhi; Chen, Ying; Feng, Jiachun; Xing, Yingqi
2015-01-01
Ultrasonography of the optic nerve sheath diameter (ONSD) is a non-invasive and rapid method that might be helpful in the identification of increased intracranial pressure (ICP). The use of an ONSD greater than 5 mm on ultrasound as an indicator of increased ICP in a Caucasian population has been studied. However, the cut-off point of this predictor in Chinese patients has not been established. Thus, we conducted this study to identify the ONSD criterion for the detection of elevated opening pressure on lumbar puncture (LP) in a Chinese population and to investigate the influencing factors. This study was a blind cross-sectional study. Patients who presented with suspected increased ICP were included. The opening pressure on LP of each participant was confirmed. We analyzed the clinical differences between the groups of patients with abnormal and normal opening pressures on LP. A receiver operating characteristic curve was constructed to determine the ONSD cut-off point for the identification of abnormal opening pressure on LP. In total, 279 patients were recruited, and 101 patients presented with elevated opening pressure on LP. ONSD was a significant independent predictor of elevated opening pressure on LP (p<0.001). However, no statistical significance was observed regarding the factors that might have affected this relationship including gender, age, body mass index, waistline, head circumference, hypertension and pathological subtype. The ONSD cut-off point for the identification of elevated opening pressure on LP was 4.1 mm; this cut-off yielded a sensitivity of 95% and a specificity of 92%. ONSD is a strong and accurate predictor of elevated opening pressure on LP. The cut-off point of this predictor in a Chinese population was remarkably lower than that found in a Caucasian population. Thus, ethnic differences should be noted when using the ONSD as an indicator of increased ICP.
Rasmussen, Line D; Helleberg, Marie; May, Margaret T; Afzal, Shoaib; Kronborg, Gitte; Larsen, Carsten S; Pedersen, Court; Gerstoft, Jan; Nordestgaard, Børge G; Obel, Niels
2015-05-01
Human immunodeficiency virus-infected individuals have increased risk of myocardial infarction (MI); however, the contribution from smoking and potentiating effects of HIV are controversial. From the Danish HIV Cohort Study and the Copenhagen General Population Study, we identified 3251 HIV-infected individuals and 13 004 population controls matched on age and gender. Data on MI were obtained from the National Hospital Registry and the National Registry of Causes of Death. We calculated adjusted incidence rate ratios (aIRR) for risk of MI and population-attributable fractions (PAF) of MI associated with smoking. In never smokers, HIV was not associated with an increased risk of MI (aIRR, 1.01; 95% confidence interval [CI], .41-2.54). In previous and current smokers, HIV was associated with a substantially increased risk of MI (aIRR, 1.78; 95% CI, .75-4.24 and aIRR, 2.83; 95% CI, 1.71-4.70). The PAF associated with ever smoking (previous or current) was 72% (95% CI, 55%-82%) for HIV-infected individuals and 24% (95% CI, 3%-40%) for population controls. If all current smokers stopped smoking, 42% (95% CI, 21%-57%) and 21% (95% CI, 12%-28%) of all MIs could potentially be avoided in these 2 populations. Smoking is associated with a higher risk of MI in the HIV-infected population than in the general population. Approximately 3 of 4 MIs among HIV-infected individuals are associated with ever smoking compared with only 1 of 4 MIs among population controls. Smoking cessation could potentially prevent more than 40% of MIs among HIV-infected individuals, and smoking cessation should be a primary focus in modern HIV care. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.
Walsh, A M
1998-01-01
During the next decade, the population over age 65 is expected to increase by 11% while the population over age 85 is expected to increase by 42%. These projections suggest that many organizations which currently provide services to the aged will be required to design a range of new products and services for this diverse population. Vertically integrated services provide a viable opportunity to competitively position an organization to respond to the diverse needs of an aged market. Since vertical integration will be essential in negotiating capitate contracts for the aged in the future, this study examined the extent of vertical integration in 116 health and social service organizations in an urban market with an expanding geriatric population.
Bonhoeffer, Sebastian
2018-01-01
The stress-induced mutagenesis hypothesis postulates that in response to stress, bacteria increase their genome-wide mutation rate, in turn increasing the chances that a descendant is able to better withstand the stress. This has implications for antibiotic treatment: exposure to subinhibitory doses of antibiotics has been reported to increase bacterial mutation rates and thus probably the rate at which resistance mutations appear and lead to treatment failure. More generally, the hypothesis posits that stress increases evolvability (the ability of a population to generate adaptive genetic diversity) and thus accelerates evolution. Measuring mutation rates under stress, however, is problematic, because existing methods assume there is no death. Yet subinhibitory stress levels may induce a substantial death rate. Death events need to be compensated by extra replication to reach a given population size, thus providing more opportunities to acquire mutations. We show that ignoring death leads to a systematic overestimation of mutation rates under stress. We developed a system based on plasmid segregation that allows us to measure death and division rates simultaneously in bacterial populations. Using this system, we found that a substantial death rate occurs at the tested subinhibitory concentrations previously reported to increase mutation rate. Taking this death rate into account lowers and sometimes removes the signal for stress-induced mutagenesis. Moreover, even when antibiotics increase mutation rate, we show that subinhibitory treatments do not increase genetic diversity and evolvability, again because of effects of the antibiotics on population dynamics. We conclude that antibiotic-induced mutagenesis is overestimated because of death and that understanding evolvability under stress requires accounting for the effects of stress on population dynamics as much as on mutation rate. Our goal here is dual: we show that population dynamics and, in particular, the numbers of cell divisions are crucial but neglected parameters in the evolvability of a population, and we provide experimental and computational tools and methods to study evolvability under stress, leading to a reassessment of the magnitude and significance of the stress-induced mutagenesis paradigm. PMID:29750784
Frenoy, Antoine; Bonhoeffer, Sebastian
2018-05-01
The stress-induced mutagenesis hypothesis postulates that in response to stress, bacteria increase their genome-wide mutation rate, in turn increasing the chances that a descendant is able to better withstand the stress. This has implications for antibiotic treatment: exposure to subinhibitory doses of antibiotics has been reported to increase bacterial mutation rates and thus probably the rate at which resistance mutations appear and lead to treatment failure. More generally, the hypothesis posits that stress increases evolvability (the ability of a population to generate adaptive genetic diversity) and thus accelerates evolution. Measuring mutation rates under stress, however, is problematic, because existing methods assume there is no death. Yet subinhibitory stress levels may induce a substantial death rate. Death events need to be compensated by extra replication to reach a given population size, thus providing more opportunities to acquire mutations. We show that ignoring death leads to a systematic overestimation of mutation rates under stress. We developed a system based on plasmid segregation that allows us to measure death and division rates simultaneously in bacterial populations. Using this system, we found that a substantial death rate occurs at the tested subinhibitory concentrations previously reported to increase mutation rate. Taking this death rate into account lowers and sometimes removes the signal for stress-induced mutagenesis. Moreover, even when antibiotics increase mutation rate, we show that subinhibitory treatments do not increase genetic diversity and evolvability, again because of effects of the antibiotics on population dynamics. We conclude that antibiotic-induced mutagenesis is overestimated because of death and that understanding evolvability under stress requires accounting for the effects of stress on population dynamics as much as on mutation rate. Our goal here is dual: we show that population dynamics and, in particular, the numbers of cell divisions are crucial but neglected parameters in the evolvability of a population, and we provide experimental and computational tools and methods to study evolvability under stress, leading to a reassessment of the magnitude and significance of the stress-induced mutagenesis paradigm.
Arredondo, Armando; Aviles, Raul
2015-01-01
The need to integrate economic and epidemiological aspects in the clinical perspective leads to a proposal for the analysis of health disparities and to an evaluation of the health services and of the new challenges which are now being faced by health system reforms in middle income countries. To identify the epidemiological changes, the demand for health services and economic burden from chronic diseases (diabetes and hypertension) in a middle income county. We conducted longitudinal analyses of costs and epidemiological changes for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations. The cost-evaluation method was used, based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2014-2016, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95%, and the Box-Pierce test. Regarding epidemiological changes expected in both diseases for 2014 vs. 2016, an increase is expected, although results predict a greater increase for diabetes, 8-12% in all three studied institutions, (p < .05). Indeed, in the case of diabetes, the increase was 41469 cases for uninsured population (SSA) and 65737 for the insured population (IMSS and ISSSTE). On hypertension cases the increase was 38109 for uninsured vs 62895 for insured. Costs in US$ ranged from $699 to $748 for annual case management per patient in the case of diabetes, and from $485 to $622 in patients with hypertension. Comparing financial consequences of health services required by insured and uninsured populations, the greater increase (23%) will be for the insured population (p < .05). The financial requirements of both diseases will amount to 19.5% of the total budget for the uninsured and 12.5% for the insured population. If the risk factors and the different health care models remain as they currently are, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant challenge is the appearance of internal competition in the use and allocation of financial resources with programs for other chronic and infectious diseases.
Arredondo, Armando; Aviles, Raul
2015-01-01
Background The need to integrate economic and epidemiological aspects in the clinical perspective leads to a proposal for the analysis of health disparities and to an evaluation of the health services and of the new challenges which are now being faced by health system reforms in middle income countries. Objective To identify the epidemiological changes, the demand for health services and economic burden from chronic diseases (diabetes and hypertension) in a middle income county. Methods We conducted longitudinal analyses of costs and epidemiological changes for diabetes and hypertension in the Mexican health system. The study population included both the insured and uninsured populations. The cost-evaluation method was used, based on the instrumentation and consensus techniques. To estimate the epidemiological changes and financial consequences for 2014–2016, six models were constructed according to the Box-Jenkins technique, using confidence intervals of 95%, and the Box-Pierce test. Results Regarding epidemiological changes expected in both diseases for 2014 vs. 2016, an increase is expected, although results predict a greater increase for diabetes, 8–12% in all three studied institutions, (p < .05). Indeed, in the case of diabetes, the increase was 41469 cases for uninsured population (SSA) and 65737 for the insured population (IMSS and ISSSTE). On hypertension cases the increase was 38109 for uninsured vs 62895 for insured. Costs in US$ ranged from $699 to $748 for annual case management per patient in the case of diabetes, and from $485 to $622 in patients with hypertension. Comparing financial consequences of health services required by insured and uninsured populations, the greater increase (23%) will be for the insured population (p < .05). The financial requirements of both diseases will amount to 19.5% of the total budget for the uninsured and 12.5% for the insured population. Conclusions If the risk factors and the different health care models remain as they currently are, the economic impact of expected epidemiological changes on the social security system will be particularly strong. Another relevant challenge is the appearance of internal competition in the use and allocation of financial resources with programs for other chronic and infectious diseases. PMID:25781625
Relationship between obesity and other risk factors and skin disease among adult Saudi population.
Khalil, Ghada M; Al Shobaili, Hani A; Alzolibani, Abdullateef; Al Robaee, Ahmad
2011-01-01
Obesity is accused for a wide spectrum of dermatologic diseases; no previous follow-up study has been conducted to investigate these conditions in adult male and female Saudi population. To describe obesity pattern using BMI and to assess the association between obesity and certain skin diseases among adult Saudi population. A retrospective cohort study of 2-year duration was conducted. The study sample was randomly selected from dermatology clinics at Qassim. Male cohorts were 61 obese adults and 48 nonobese adults. Female cohorts were 32 obese adults and 36 nonobese adults. Measurement of BMI, waist-hip ratio, fasting glucose, blood pressure, and dermatological examination was performed. Skin disease incidence was significantly increased among exposed rather than nonexposed cohorts with a relative risk of 2.3 in male cohort and 2.3 in female cohort. Acanthosis nigricans and striae distensae incidence increased in exposed men and women with highly significant difference from nonexposed groups. Skin tag incidence significantly increased in the exposed male cohorts only but not the female cohort. Hirsutism, dry skin, pruritis, and planter keratosis all showed nonsignificant differences. The most frequently reported infections in obese men were tinea pedis (18%), intertrigo (14.7%), and bacterial folliculitis (13.1%) with significant difference. BMI was the only risk factor that regresses on skin disease occurrence in study groups. Our study linked incidence of acanthosis nigricans and striae distensae to obesity in both female and male adult population but showed sex difference for other skin diseases, which raised many questions and requires further longer duration follow-up studies.
High hunting pressure selects for earlier birth date: Wild boar as a case study
Gamelon, M.; Besnard, A.; Gaillard, J.-M.; Servanty, S.; Baubet, E.; Brandt, S.; Gimenez, O.
2011-01-01
Exploitation by humans affects the size and structure of populations. This has evolutionary and demographic consequences that have typically being studied independent of one another. We here applied a framework recently developed applying quantitative tools from population ecology and selection gradient analysis to quantify the selection on a quantitative trait-birth date-through its association with multiple fitness components. From the long-term monitoring (22 years) of a wild boar (Sus scrofa scrofa) population subject to markedly increasing hunting pressure, we found that birth dates have advanced by up to 12 days throughout the study period. During the period of low hunting pressure, there was no detectable selection. However, during the period of high hunting pressure, the selection gradient linking breeding probability in the first year of life to birth date was negative, supporting current life-history theory predicting selection for early births to reproduce within the first year of life with increasing adult mortality. ?? 2011 The Author(s). Evolution?? 2011 The Society for the Study of Evolution..
Review of benzodiazepine use in children and adolescents.
Witek, Malgorzata W; Rojas, Veronica; Alonso, Carmen; Minami, Haruka; Silva, Raul R
2005-01-01
Clinically, benzodiazepines are used in adult populations much more frequently than in children and adolescents. There may be a number of reasons for this disparity including a dearth of well controlled clinical studies and the issue of dependence associated with long term use. However, over a ten year span there has been nearly a three fold increase in the use patterns for these agents in the child population. In open studies much of the literature has indicated potentially useful results, but these findings have not been replicated when more refined methodological studies have been conducted. The lack of encouraging results in these later studies may be attributable to a number of factors such as modest sample sizes and less than optimal patient selection. Nonetheless, with increasing prescriptions being written for these agents it is not clear what is compelling clinicians to use them. In this paper we will review the available literature on benzodiazepine use in the child and adolescent population, focusing primarily on psychiatric applications.
Programs to Increase High School Completion
Hahn, Robert A.; Knopf, John A.; Wilson, Sandra Jo; Truman, Benedict I.; Milstein, Bobby; Johnson, Robert L.; Fielding, Jonathan E.; Muntaner, Carles J.M.; Jones, Camara Phyllis; Fullilove, Mindy T.; Moss, Regina Davis; Uefffng, Erin; Hunt, Pete C.
2015-01-01
Context High school completion (HSC) is an established predictor of long-term morbidity and mortality. U.S. rates of HSC are substantially lower among students from low-income families and most racial/ethnic minority populations than students from high-income families and the non-Hispanic white population. This systematic review assesses the effectiveness of programs to increase HSC and the potential of these programs to improve lifelong health among at-risk students. Evidence acquisition A search located a meta-analysis (search period 1985–2010/2011) on the effects of programs to increase HSC or General Educational Development (GED) diploma receipt; the meta-analysis was concordant with Community Guide definitions and methodologic standards. Programs were assessed separately for the general student population (152 studies) and students who were parents or pregnant (15 studies). A search for studies published between 2010 and August 2012 located ten more recent studies, which were assessed for consistency with the meta-analysis. Analyses were conducted in 2013. Evidence synthesis The review focused on the meta-analysis. Program effectiveness was measured as the increased rate of HSC (or GED receipt) by the intervention group compared with controls. All assessed program types were effective in increasing HSC in the general student population: vocational training, alternative schooling, social–emotional skills training, college-oriented programming, mentoring and counseling, supplemental academic services, school and class restructuring, multiservice packages, attendance monitoring and contingencies, community service, and case management. For students who had children or were pregnant, attendance monitoring and multiservice packages were effective. Ten studies published after the search period for the meta-analysis were consistent with its findings. Conclusions There is strong evidence that a variety of HSC programs can improve high school or GED completion rates. Because many programs are targeted to high-risk students and communities, they are likely to advance health equity. PMID:25818117
Fleuriet, A; Periquet, G; Anxolabéhère, D
1990-01-01
In natural populations of Drosophila melanogaster, sigma virus is usually present in a minority of individuals. The virus is transmitted transovarially but is not contagious from fly to fly. Two viral Types (I and II) are found in populations. One of them (Type II) is better adapted to an allele for resistance to the virus, present as a polymorphism in fly populations. Previous observations have led to the hypothesis that a viral Type II originating in central France might be invading populations. The study of Languedoc populations was undertaken to examine this hypothesis. Two striking phenomena were observed. The strong increase in Type II clones frequency (from 0.53 to 0.91) confirmed that there was invasion in this region. The frequency of infected flies also increased dramatically, at levels never observed elsewhere yet, which indicates that Languedoc should present some unusual characteristics. The epidemiological consequences of such a burst, in the case of a pathogenic virus would have to be taken into consideration. Significant changes in other viral characteristics, from 1983 to 1987, in Languedoc populations have also been documented.
Li, Shou-Li; Vasemägi, Anti; Ramula, Satu
2016-01-01
Background and Aims Assessing the demographic consequences of genetic variation is fundamental to invasion biology. However, genetic and demographic approaches are rarely combined to explore the effects of genetic variation on invasive populations in natural environments. This study combined population genetics, demographic data and a greenhouse experiment to investigate the consequences of genetic variation for the population fitness of the perennial, invasive herb Lupinus polyphyllus. Methods Genetic and demographic data were collected from 37 L. polyphyllus populations representing different latitudes in Finland, and genetic variation was characterized based on 13 microsatellite loci. Associations between genetic variation and population size, population density, latitude and habitat were investigated. Genetic variation was then explored in relation to four fitness components (establishment, survival, growth, fecundity) measured at the population level, and the long-term population growth rate (λ). For a subset of populations genetic variation was also examined in relation to the temporal variability of λ. A further assessment was made of the role of natural selection in the observed variation of certain fitness components among populations under greenhouse conditions. Key Results It was found that genetic variation correlated positively with population size, particularly at higher latitudes, and differed among habitat types. Average seedling establishment per population increased with genetic variation in the field, but not under greenhouse conditions. Quantitative genetic divergence (QST) based on seedling establishment in the greenhouse was smaller than allelic genetic divergence (F′ST), indicating that unifying selection has a prominent role in this fitness component. Genetic variation was not associated with average survival, growth or fecundity measured at the population level, λ or its variability. Conclusions The study suggests that although genetic variation may facilitate plant invasions by increasing seedling establishment, it may not necessarily affect the long-term population growth rate. Therefore, established invasions may be able to grow equally well regardless of their genetic diversity. PMID:26420202
Weeks, Andrew R; Stoklosa, Jakub; Hoffmann, Ary A
2016-01-01
As increasingly fragmented and isolated populations of threatened species become subjected to climate change, invasive species and other stressors, there is an urgent need to consider adaptive potential when making conservation decisions rather than focussing on past processes. In many cases, populations identified as unique and currently managed separately suffer increased risk of extinction through demographic and genetic processes. Other populations currently not at risk are likely to be on a trajectory where declines in population size and fitness soon appear inevitable. Using datasets from natural Australian mammal populations, we show that drift processes are likely to be driving uniqueness in populations of many threatened species as a result of small population size and fragmentation. Conserving and managing such remnant populations separately will therefore often decrease their adaptive potential and increase species extinction risk. These results highlight the need for a paradigm shift in conservation biology practise; strategies need to focus on the preservation of genetic diversity at the species level, rather than population, subspecies or evolutionary significant unit. The introduction of new genetic variants into populations through in situ translocation needs to be considered more broadly in conservation programs as a way of decreasing extinction risk by increasing neutral genetic diversity which may increase the adaptive potential of populations if adaptive variation is also increased.
Corporate Social Responsibility Initiatives Addressing Social Exclusion in Bangladesh
2009-01-01
The private sector is often seen as a driver of exclusionary processes rather than a partner in improving the health and welfare of socially-excluded populations. However, private-sector initiatives and partnerships—collectively labelled corporate social responsibility (CSR) initiatives—may be able to positively impact social status, earning potential, and access to services and resources for socially-excluded populations. This paper presents case studies of CSR projects in Bangladesh that are designed to reduce social exclusion among marginalized populations and explores whether CSR initiatives can increase economic and social capabilities to reduce exclusion. The examples provide snapshots of projects that (a) increase job-skills and employment opportunities for women, disabled women, and rehabilitated drug-users and (b) provide healthcare services to female workers and their communities. The CSR case studies cover a limited number of people but characteristics and practices replicable and scaleable across different industries, countries, and populations are identified. Common success factors from the case studies form the basis for recommendations to design and implement more CSR initiatives targeting socially-excluded groups. The analysis found that CSR has potential for positive and lasting impact on developing countries, especifically on socially-excluded populations. However, there is a need for additional monitoring and critical evaluation. PMID:19761088
Depression in Cardiovascular Patients in Middle Eastern Populations: A Literature Review.
Donnelly, Tam Truong; Al Suwaidi, Jassim Mohd; Al-Qahtani, Awad; Asaad, Nidal; Qader, Najlaa Abdul; Singh, Rajvir; Fung, Tak Shing; Mueed, Irem; Sharara, Shima; El Banna, Noha; Omar, Sarah
2015-08-01
Cardiovascular disease (CVD) is increasing in Middle Eastern countries. Depression is associated with increased morbidity and mortality rates among cardiovascular (CV) patients. Early detection of and intervention for depression among CV patients can reduce morbidity and mortality and save health care costs. Public information on mental health care needs of Arab CV patients living in Middle East regions is scattered and limited. This literature review surveyed and summarized research studies to learn what is known about the relationship between depression and CVD in Middle Eastern populations. The information will raise awareness among health care professionals and policy makers regarding the clinical significance of depression in Arab CV patients. It might contribute to development of culturally appropriate and effective mental health care services. Multiple databases were searched and 60 articles were assessed, including studies that investigated depression in Arab CV patient populations, physiological mechanisms of depression-CVD comorbidity, and intervention strategies that affect CV risk in depressed Arab patients. We discuss the extent to which this issue has been explored in Arab populations living in Middle East regions and Arab populations living abroad. We recommend that more comprehensive and in-depth research studies be conducted with Arab cardiac patients to enable implementation of culturally appropriate and effective mental health care interventions.
Barros, Ana B; Dias, Sonia F; Martins, Maria Rosario O
2015-10-30
In public health, hard-to-reach populations are often recruited by non-probabilistic sampling methods that produce biased results. In order to overcome this, several sampling methods have been improved and developed in the last years. The aim of this systematic review was to identify all current methods used to survey most-at-risk populations of men who have sex with men and sex workers. The review also aimed to assess if there were any relations between the study populations and the sampling methods used to recruit them. Lastly, we wanted to assess if the number of publications originated in middle and low human development (MLHD) countries had been increasing in the last years. A systematic review was conducted using electronic databases and a total of 268 published studies were included in the analysis. In this review, 11 recruitment methods were identified. Semi-probabilistic methods were used most commonly to survey men who have sex with men, and the use of the Internet was the method that gathered more respondents. We found that female sex workers were more frequently recruited through non-probabilistic methods than men who have sex with men (odds = 2.2; p < 0.05; confidence interval (CI) [1.1-4.2]). In the last 6 years, the number of studies based in middle and low human development countries increased more than the number of studies based in very high and high human development countries (odds = 2.5; p < 0.05; CI [1.3-4.9]). This systematic literature review identified 11 methods used to sample men who have sex with men and female sex workers. There is an association between the type of sampling method and the population being studied. The number of studies based in middle and low human development countries has increased in the last 6 years of this study.
Cadogan, Cathal A; Ryan, Cristín; Cahir, Caitriona; Bradley, Colin P; Bennett, Kathleen
2018-06-01
The aim of this study was to examine prescribing trends for benzodiazepines and Z-drugs to General Medical Services (GMS) patients in Ireland. A repeated cross-sectional analysis of the national pharmacy claims database was conducted for GMS patients aged ≥16 years from 2005 to 2015. Prescribing rates per 1000 eligible GMS population were calculated with 95% confidence intervals (CIs). Negative binomial regression was used to determine longitudinal trends and compare prescribing rates across years, gender and age groups. Duration of supply and rates of concomitant benzodiazepine and Z-drug prescribing were determined. Age (16-44, 45-64, ≥65 years) and gender trends were investigated. Benzodiazepine prescribing rates decreased significantly from 225.92/1000 population (95% CI 224.94-226.89) in 2005 to 166.07/1000 population (95% CI 165.38-166.75) in 2015 (P < 0.0001). Z-drug prescribing rates increased significantly from 95.36/1000 population (95% CI 94.73-96.00) in 2005 to 109.11/1000 population (95% CI 108.56-109.67) in 2015 (P = 0.048). Approximately one-third of individuals dispensed either benzodiazepines or Z-drugs were receiving long-term prescriptions (>90 days). The proportion of those receiving >1 benzodiazepine and/or Z-drug concomitantly increased from 11.9% in 2005 to 15.3% in 2015. Benzodiazepine and Z-drug prescribing rates were highest for older women (≥65 years) throughout the study period. Benzodiazepine prescribing to the GMS population in Ireland decreased significantly from 2005 to 2015, and was coupled with significant increases in Z-drug prescribing. The study shows that benzodiazepine and Z-drug prescribing is common in this population, with high proportions of individuals receiving long-term prescriptions. Targeted interventions are needed to reduce potentially inappropriate long-term prescribing and use of these medications in Ireland. © 2018 The British Pharmacological Society.
Increasing rates of diabetes amongst status Aboriginal youth in Alberta, Canada
Oster, Richard T.; Johnson, Jeffrey A.; Balko, Stephanie U.; Svenson, Larry W.; Toth, Ellen L.
2012-01-01
Objectives To track and compare trends in diabetes rates from 1995 to 2007 for Status Aboriginal and general population youth. Study design Longitudinal observational research study (quantitative) using provincial administrative data. Methods De-identified data was obtained from Alberta Health and Wellness administrative databases for Status Aboriginal (First Nations and Inuit people with Treaty status) and general population youth (<20 years). Diabetes cases were identified using the National Diabetes Surveillance System algorithm. Crude annual diabetes prevalence and incidence rates were calculated. The likelihood of being a prevalent case and incident case of diabetes for the 2 populations was compared for the year 2007. Average Annual Percent Changes (AAPC) in prevalence and incidence from 1995 to 2007 were determined and compared between the 2 groups to examine trends over time. Results While the prevalence of diabetes was higher in the general population in 1995, by 2007 there were no between group differences, reflected in the significantly higher AAPC of 6.98 for Status Aboriginal youth. Status Aboriginal males had a lower diabetes risk in 1995 compared with females, and experienced a greater increase in prevalence over the 13 years (AAPC 9.18) so that by 2007 their rates were equivalent to those of the females. Differences in diabetes incidence trends were only observed among male youth, where increases in incidence were greater for Status Aboriginal (AAPC 11.65) compared to general population males (AAPC 4.62) (p = 0.03). Conclusion Youth-onset diabetes is an increasing problem in Alberta, especially among young Status Aboriginal males. PMID:22584517
Shi, Hon-Yi; Hwang, Shiuh-Lin; Lee, I-Chen; Chen, I-Te; Lee, King-Teh; Lin, Chih-Lung
2014-12-01
The authors sought to analyze trends in hospital resource utilization and mortality rates in a population of patients who had received traumatic brain injury (TBI) surgery. This nationwide population-based cohort study retrospectively analyzed 18,286 patients who had received surgical treatment for TBI between 1998 and 2010. The multiple linear regression model and Cox proportional hazards model were used for multivariate assessment of outcome predictors. The prevalence rate of surgical treatment for patients with TBI gradually but significantly (p < 0.001) increased by 47.6% from 5.0 per 100,000 persons in 1998 to 7.4 per 100,000 persons in 2010. Age, sex, Deyo-Charlson comorbidity index score, hospital volume, and surgeon volume were significantly associated with TBI surgery outcomes (p < 0.05). Over the 12-year period analyzed, the estimated mean hospital treatment cost increased 19.06%, whereas the in-hospital mortality rate decreased 10.9%. The estimated mean time of overall survival after TBI surgery (± SD) was 83.0 ± 4.2 months, and the overall in-hospital and 1-, 3-, and 5-year survival rates were 74.5%, 67.3%, 61.1%, and 57.8%, respectively. These data reveal an increased prevalence of TBI, especially in older patients, and an increased hospital treatment cost but a decreased in-hospital mortality rate. Health care providers and patients should recognize that attributes of the patient and of the hospital may affect hospital resource utilization and the mortality rate. These results are relevant not only to other countries with similar population sizes but also to countries with larger populations.
Increased inequality in mortality from road crashes among Arabs and Jews in Israel.
Magid, Avi; Leibovitch-Zur, Shalhevet; Baron-Epel, Orna
2015-01-01
Previous studies in several countries have shown that the economically disadvantaged seem to have a greater risk of being involved in a car crash. The aim of the present study was to compare rates and trends in mortality and injury from road crashes by age among the Arab and Jewish populations in Israel. Data on road crashes with casualties (2003-2011) from the Israeli Central Bureau of Statistics were analyzed. Age-adjusted road crash injury rates and mortality rates for 2003 to 2011 were calculated and time trends for each age group and population group are presented. Time trend significance was evaluated by linear regression models. Arabs in Israel are at increased risk of injury and mortality from road crashes compared to Jews. Road crash injury rates have significantly decreased in both populations over the last decade, although the rates have been persistently higher among Arabs. Road crash mortality rates have also decreased significantly in the Jewish population but not in the Arab population. This implies an increase in the disparity in mortality between Jews and Arabs. The most prominent differences in road crash injury and mortality rates between Arabs and Jews can be observed in young adults and young children. The reduction in road crashes in the last decade is a positive achievement. However, the reductions are not equal among Arabs and Jews in Israel. Therefore, an increase in the disparities in mortality from road crashes is apparent. Public health efforts need to focus specifically on decreasing road crashes in the Arab community.
Differences in psychotropic drug prescriptions among ethnic groups in the Netherlands.
Wittkampf, Laura Christina; Smeets, Hugo M; Knol, Mirjam J; Geerlings, Mirjam I; Braam, Arjan W; De Wit, Niek J
2010-08-01
Psychotropic drug use in Europe and the USA has increased in the past 20 years. The rise in mental health-care use instigated a debate about possible differences in prevalence rates between different ethnic groups in the Netherlands, although the exact differences were unknown. The aim of this study was to determine whether these minority groups were more or less likely than the native population to receive psychotropic drugs. A descriptive population study was conducted using the Agis Health Database, containing demographic and health-care consumption data of approximately 1.5 million inhabitants of the Netherlands. Rates of prescriptions of psychotropic drugs from 2001 to 2006 and adjusted odds ratios for psychotropic drug prescriptions among native Dutch, Turkish and Moroccan ethnic groups were calculated. These data were analysed using logistic regression, after being adjusted for age, gender and socioeconomic status. The mean year prevalence of psychotropic drug prescriptions from 2001 to 2006 was 14.0%. Except for a decrease in anxiolytic drugs, the prescriptions of psychotropic drugs increased from 2001 to 2006. These trends were the same for all of the ethnic groups considered. Among both the Moroccan and Turkish populations, there was a higher risk of antidepressant and antipsychotic drug prescriptions, and a pronounced lower risk of ADHD medication and lithium prescriptions compared to the native population. Among the Turkish population, the risk of anxiolytic drug prescriptions was greater than in the native population. Compared to the native population in the Netherlands, first- and second-generation Turkish and Moroccan immigrants had an increased risk of antidepressant and antipsychotic drug prescriptions and a decreased risk of ADHD medication and Lithium prescriptions. Further research is needed to clarify whether patients of different ethnic backgrounds with the same symptoms receive similar diagnosis and adequate treatment.
Shehnaz, Syed Ilyas; Guruswami, Gomathi Kadayam; Ibrahim, Salwa Abdelzaher Mabrouk; Mustafa, Sana Abdul Jabbar
2017-01-01
Background: To evaluate the level of knowledge regarding warning signs, presenting symptoms and risk factors associated with coronary heart disease (CHD) among population of Dubai and Northern Emirates in UAE. Materials and Methods: A cross sectional survey of 1367 residents of Dubai and Northern Emirates was conducted using a self-administered questionnaire. Results: Respondents were classified into two groups: Young Adult Population (YAP; 18-24 years of age) and General Population (GP; 25 years and older). Majority of participants were males (56.7%) and of South Asian (57.5%) or Middle-Eastern (30.8%) ethnicity. Regarding presenting symptoms of CHD, chest pain was identified by around 80% of population, whereas pain in the left shoulder was recognized by 61% of GP and 44% of YAP. Atypical symptoms were poorly identified. Regarding risk factors, only one-fourth population knew that males were at higher risk compared to premenopausal females. Few knew that the risk increases in females after menopause and that the risk is higher for females who smoke and use oral contraceptives. 62% knew that the survivors of a heart attack are at high risk of recurrences. Except for tobacco smoke, hypercholesterolemia and hypertension, knowledge of other risk factors was not satisfactory. Older adults and females had comparatively higher level of knowledge. Conclusion: Knowledge level of many of the symptoms and risk factors of CHD is unsatisfactory. There is, therefore, a need to increase the awareness in the population of UAE. The knowledge gaps identified through this study can be addressed through health campaigns to increase the awareness about warning signs, symptoms and modifiable risk factors. . PMID:29181228
O'Keefe, Kaitlin A; Shafir, Shira C; Shoaf, Kimberley I
2013-01-01
Local health departments (LHDs) must have sufficient numbers of staff functioning in an epidemiologic role with proper education, training, and skills to protect the health of communities they serve. This pilot study was designed to describe the composition, training, and competency level of LHD staff and examine the hypothesis that potential disparities exist between LHDs serving different sized populations. Cross-sectional surveys were conducted with directors and epidemiologic staff from a sample of 100 LHDs serving jurisdictions of varied sizes. Questionnaires included inquiries regarding staff composition, education, training, and measures of competency modeled on previously conducted studies by the Council of State and Territorial Epidemiologists. Number of epidemiologic staff, academic degree distribution, epidemiologic training, and both director and staff confidence in task competencies were calculated for each LHD size strata. Disparities in measurements were observed in LHDs serving different sized populations. LHDs serving small populations reported a smaller average number of epidemiologic staff than those serving larger jurisdictions. As size of population served increased, percentages of staff and directors holding bachelors' and masters' degrees increased, while those holding RN degrees decreased. A higher degree of perceived competency of staff in most task categories was reported in LHDs serving larger populations. LHDs serving smaller populations reported fewer epidemiologic staff, therefore might benefit from additional resources. Differences observed in staff education, training, and competencies suggest that enhanced epidemiologic training might be particularly needed in LHDs serving smaller populations. RESULTS can be used as a baseline for future research aimed at identifying areas where training and personnel resources might be particularly needed to increase the capabilities of LHDs.
Demographic responses of Pinguicula ionantha to prescribed fire: a regression-design LTRE approach.
Kesler, Herbert C; Trusty, Jennifer L; Hermann, Sharon M; Guyer, Craig
2008-06-01
This study describes the use of periodic matrix analysis and regression-design life table response experiments (LTRE) to investigate the effects of prescribed fire on demographic responses of Pinguicula ionantha, a federally listed plant endemic to the herb bog/savanna community in north Florida. Multi-state mark-recapture models with dead recoveries were used to estimate survival and transition probabilities for over 2,300 individuals in 12 populations of P. ionantha. These estimates were applied to parameterize matrix models used in further analyses. P. ionantha demographics were found to be strongly dependent on prescribed fire events. Periodic matrix models were used to evaluate season of burn (either growing or dormant season) for fire return intervals ranging from 1 to 20 years. Annual growing and biannual dormant season fires maximized population growth rates for this species. A regression design LTRE was used to evaluate the effect of number of days since last fire on population growth. Maximum population growth rates calculated using standard asymptotic analysis were realized shortly following a burn event (<2 years), and a regression design LTRE showed that short-term fire-mediated changes in vital rates translated into observed increases in population growth. The LTRE identified fecundity and individual growth as contributing most to increases in post-fire population growth. Our analyses found that the current four-year prescribed fire return intervals used at the study sites can be significantly shortened to increase the population growth rates of this rare species. Understanding the role of fire frequency and season in creating and maintaining appropriate habitat for this species may aid in the conservation of this and other rare herb bog/savanna inhabitants.
Jones, Amanda L; Downs, Colleen T
2011-01-01
Worldwide domestic and feral cat (Felis catus) numbers have increased. Concerns regarding high populations of feral cats in urban areas include wildlife predation, public nuisance, and disease. This study aimed to estimate the size of the feral cat population on 5 campuses of the University of KwaZulu-Natal, South Africa, to determine whether sterilization has an effect and to make management recommendations. The study used both the total count and mark-recapture methods to estimate the feral cat population on each campus. The study chose a noninvasive method of taking photographs to "mark" individuals and record those who were sterilized. The study estimated a total of 186 cats on all campuses and density at 161 cats km(-2). There was a negative relationship between sterilization and numbers. Sites with higher sterilization showed a lower proportion of younger cats. At the average sterilization of 55%, the population, according to predictions, would remain stable at fecundity, survival, and immigration rates reported by cat caretakers. However, caretakers underestimated cat abundance by 7 ± 37 SD%. Caretakers' feral cat sterilization and feeding programs appear to provide a service to the university community. Key management recommendations were to increase sterilization to 90% to reduce the population over the long term and to raise funds to support the costs incurred by voluntary cat caretakers.
Population structure and inbreeding from pedigree analysis of purebred dogs.
Calboli, Federico C F; Sampson, Jeff; Fretwell, Neale; Balding, David J
2008-05-01
Dogs are of increasing interest as models for human diseases, and many canine population-association studies are beginning to emerge. The choice of breeds for such studies should be informed by a knowledge of factors such as inbreeding, genetic diversity, and population structure, which are likely to depend on breed-specific selective breeding patterns. To address the lack of such studies we have exploited one of the world's most extensive resources for canine population-genetics studies: the United Kingdom (UK) Kennel Club registration database. We chose 10 representative breeds and analyzed their pedigrees since electronic records were established around 1970, corresponding to about eight generations before present. We find extremely inbred dogs in each breed except the greyhound and estimate an inbreeding effective population size between 40 and 80 for all but 2 breeds. For all but 3 breeds, >90% of unique genetic variants are lost over six generations, indicating a dramatic effect of breeding patterns on genetic diversity. We introduce a novel index Psi for measuring population structure directly from the pedigree and use it to identify subpopulations in several breeds. As well as informing the design of canine population genetics studies, our results have implications for breeding practices to enhance canine welfare.
A Study of Optimum Population Levels—A Progress Report*
Singer, S. Fred
1972-01-01
The purpose of this study is to explore different approaches and to develop a methodology that will allow a calculation of “optimum levels of population.” The discussion is specialized to the United States, but the methodology should be broad enough to handle other countries, including less-developed countries. The study is based on economics, but with major inputs from the areas of technology, natural resources management, environmental effects, and demography. The general approach will be to develop an index for quality of life (IQL or Q-index) and to maximize this index as a function of level and distribution of population. The technique consists of a reshuffling of national income accounts so as to be able to go from the Gross National Product (GNP) to the index for quality of life, plus a careful discussion of what is and what is not to be included. The initial part of the study consists of a projection of the index for quality of life as population level increases and as population distribution changes, under the assumption of various technologies, particularly as these relate to the consumption of minerals, energy, and other natural resources. One would expect that as economic growth continues, an increasing fraction of expenditures would be for the diseconomics produced by population growth and economic growth. This study should be useful by providing a rational base for governmental policies regarding population, both in the United States and abroad. Another application of the study is to technology assessment, by measurement of the impact on economic well-being through the introduction of new technologies. Therefore, one can gauge the necessary and desirable investments in certain new technologies. In general, mathematical models resulting from this study can become useful diagnostic tools to analyze the consequences of various public and private policy decisions. PMID:4509346
National Trends and Geographic Variation in Availability of Home Health Care: 2002–2015
Wang, Yun; Leifheit-Limson, Erica C; Fine, Jonathan; Pandolfi, Michelle M; Gao, Yan; Liu, Fanglin; Eckenrode, Sheila; Lichtman, Judith H
2017-01-01
Objectives To evaluate national trends and geographic variation in the availability of home health care from 2002–2015 and identify county-specific characteristics associated with home health care. Design Observational study Setting All counties in the United States Participants All Medicare-certified home health agencies included in the Centers for Medicare & Medicaid Services Home Health Compare system. Measurements County-specific availability of home health care, defined as the number of available home health agencies that provided services to a given county per 100,000 population aged ≥18 years. Results The study included 15,184 Medicare-certified home health agencies that served 97% of U.S. ZIP codes. Between 2002–2003 and 2014–2015, the county-specific number of available home health agencies per 100,000 population aged ≥18 years increased from 14.7 to 21.8 and the median (inter-quartile range) population that was serviced by at least one home health agency increased from 403,605 (890,329) to 455,488 (1,039,328). Considerable geographic variation in the availability of home health care was observed. The West, North-East, and South Atlantic regions had lower home health care availability than the Central regions, and this pattern persisted over the study period. Counties with higher median income, a larger senior population, higher rates of households without a car and low access to stores, more obesity, greater inactivity, and higher proportions of non-Hispanic white, non-Hispanic black, and Hispanic populations were more likely to have higher availability of home health care. Conclusion The availability of home health care increased nationwide during the study period, but there was much geographic variation. PMID:28322441
The assessment of biases in the acoustic discrimination of individuals
Šálek, Martin
2017-01-01
Animal vocalizations contain information about individual identity that could potentially be used for the monitoring of individuals. However, the performance of individual discrimination is subjected to many biases depending on factors such as the amount of identity information, or methods used. These factors need to be taken into account when comparing results of different studies or selecting the most cost-effective solution for a particular species. In this study, we evaluate several biases associated with the discrimination of individuals. On a large sample of little owl male individuals, we assess how discrimination performance changes with methods of call description, an increasing number of individuals, and number of calls per male. Also, we test whether the discrimination performance within the whole population can be reliably estimated from a subsample of individuals in a pre-screening study. Assessment of discrimination performance at the level of the individual and at the level of call led to different conclusions. Hence, studies interested in individual discrimination should optimize methods at the level of individuals. The description of calls by their frequency modulation leads to the best discrimination performance. In agreement with our expectations, discrimination performance decreased with population size. Increasing the number of calls per individual linearly increased the discrimination of individuals (but not the discrimination of calls), likely because it allows distinction between individuals with very similar calls. The available pre-screening index does not allow precise estimation of the population size that could be reliably monitored. Overall, projects applying acoustic monitoring at the individual level in population need to consider limitations regarding the population size that can be reliably monitored and fine-tune their methods according to their needs and limitations. PMID:28486488
Newtonraj, Ariarathinam; Murugan, Natesan; Singh, Zile; Chauhan, Ramesh Chand; Velavan, Anandan; Mani, Manikandan
2017-05-01
Physical inactivity is the fourth leading cause of death worldwide. Increase in physical activity decreases the incidence of cardiovascular diseases, Type 2 diabetes, stroke, and improves psychological wellbeing. To study the level of physical inactivity among the adult population in an urban area of Puducherry in India and its associated risk factors. This cross-sectional study was conducted among 569 adult participants from an urban area of Pondicherry. The level of physical inactivity was measured by using WHO standard Global Physical Activity Questionnaire (GPAQ). Overall prevalence of physical inactivity in our study was 49.7% (CI: 45.6-53.8). Among the physically active people, contribution of physical activity by work was 77.4%, leisure time activities were 11.6% and transport time was 11%. Both men and women were equally inactive {Physically inactive among women was 50% (CI:44.1-55.9)} and {Physically inactive among men was 49.5% (CI:43.8-55.2)}. Prevalence of physical inactivity was increasing with increasing age. Non tobacco users were two times more active than tobacco users {Adjusted Odds Ratio: 2.183 (1.175- 4.057)}. Employed were more active as compared to retired {Adjusted Odds Ratio: 0.412 (0.171-0.991)}, students {Adjusted Odds Ratio: 0.456 (0.196-1.060)}, house wives {Adjusted Odds Ratio: 0.757 (0.509-1.127)} and unemployed {Adjusted Odds Ratio: 0.538 (0.271-1.068)}. Non alcoholics were only 0.34 times as active as alcoholics. Level of physical activity was found to be insufficient among adult urban population of Puducherry. Working adult population found to be active, that too due to their work pattern. There is a need to promote leisure time and travelling time physical activity.
National Trends and Geographic Variation in Availability of Home Health Care: 2002-2015.
Wang, Yun; Leifheit-Limson, Erica C; Fine, Jonathan; Pandolfi, Michelle M; Gao, Yan; Liu, Fanglin; Eckenrode, Sheila; Lichtman, Judith H
2017-07-01
To evaluate national trends and geographic variation in the availability of home health care from 2002 to 2015 and identify county-specific characteristics associated with home health care. Observational study. All counties in the United States. All Medicare-certified home health agencies included in the Centers for Medicare & Medicaid Services Home Health Compare system. County-specific availability of home health care, defined as the number of available home health agencies that provided services to a given county per 100,000 population aged ≥18 years. The study included 15,184 Medicare-certified home health agencies that served 97% of U.S. ZIP codes. Between 2002-2003 and 2014-2015, the county-specific number of available home health agencies per 100,000 population aged ≥18 years increased from 14.7 to 21.8 and the median (inter-quartile range) population that was serviced by at least one home health agency increased from 403,605 (890,329) to 455,488 (1,039,328). Considerable geographic variation in the availability of home health care was observed. The West, North East, and South Atlantic regions had lower home health care availability than the Central regions, and this pattern persisted over the study period. Counties with higher median income, a larger senior population, higher rates of households without a car and low access to stores, more obesity, greater inactivity, and higher proportions of non-Hispanic white, non-Hispanic black, and Hispanic populations were more likely to have higher availability of home health care. The availability of home health care increased nationwide during the study period, but there was much geographic variation. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.
Population-based study of presbyopia in Shahroud, Iran.
Hashemi, Hassan; Khabazkhoob, Mehdi; Jafarzadehpur, Ebrahim; Mehravaran, Shiva; Emamian, Mohammad Hassan; Yekta, AbbasAli; Shariati, Mohammad; Fotouhi, Akbar
2012-12-01
There is limited information regarding the prevalence of presbyopia in different parts of the world. The add power and the prevalence of presbyopia by age and gender in general population of Shahroud, north of Iran, were studied. Population-based cross-sectional study. Using random cluster sampling, 6311 people from the 40- to 64-year-old population of Shahroud were invited. Of the invited population, 5190 individuals (82.2%) participated in the study. Presbyopia was defined as the correction of near vision to logMAR 1 (N8 point) with at least 1 D of add power. Near visual acuity of participants was evaluated with a logMAR chart at a distance of 40 cm. Mean add power in the age groups of 40-44, 45-49, 50-54, 55-59 and 60-64 years was 0.65, 1.30, 1.70, 1.87 and 2.08 D, respectively. For each 5-year increase in age, a 0.35 D increase in add power was noted. The prevalence of presbyopia was 58.15% (95% confidence interval: 56.46-59.84). Presbyopia was more prevalent in women (P < 0.001) and increased with ageing more in women than in men (P < 0.001). Furthermore, in the 60-64-year-old age group, 11% of men and 23% of women were not presbyopic. Compared with other reports, the add power in different age groups was 0.5 D less, and presbyopia was less prevalent. More than 50% of the over 45-year-old individuals were presbyopic and 17% of the over 60 individuals were free of this condition. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.
Experimental evolution under hyper-promiscuity in Drosophila melanogaster.
Perry, Jennifer C; Joag, Richa; Hosken, David J; Wedell, Nina; Radwan, Jacek; Wigby, Stuart
2016-06-16
The number of partners that individuals mate with over their lifetime is a defining feature of mating systems, and variation in mate number is thought to be a major driver of sexual evolution. Although previous research has investigated the evolutionary consequences of reductions in the number of mates, we know little about the costs and benefits of increased numbers of mates. Here, we use a genetic manipulation of mating frequency in Drosophila melanogaster to create a novel, highly promiscuous mating system. We generated D. melanogaster populations in which flies were deficient for the sex peptide receptor (SPR) gene - resulting in SPR- females that mated more frequently - and genetically-matched control populations, and allowed them to evolve for 55 generations. At several time-points during this experimental evolution, we assayed behavioural, morphological and transcriptional reproductive phenotypes expected to evolve in response to increased population mating frequencies. We found that males from the high mating frequency SPR- populations evolved decreased ability to inhibit the receptivity of their mates and decreased copulation duration, in line with predictions of decreased per-mating investment with increased sperm competition. Unexpectedly, SPR- population males also evolved weakly increased sex peptide (SP) gene expression. Males from SPR- populations initially (i.e., before experimental evolution) exhibited more frequent courtship and faster time until mating relative to controls, but over evolutionary time these differences diminished or reversed. In response to experimentally increased mating frequency, SPR- males evolved behavioural responses consistent with decreased male post-copulatory investment at each mating and decreased overall pre-copulatory performance. The trend towards increased SP gene expression might plausibly relate to functional differences in the two domains of the SP protein. Our study highlights the utility of genetic manipulations of animal social and sexual environments coupled with experimental evolution.
Kim, Jung-Wook; Lee, Chang Kyun; Rhee, Sang Youl; Oh, Chi Hyuck; Shim, Jae-Jun; Kim, Hyo Jong
2018-04-01
Data regarding health-care costs and utilization for inflammatory bowel disease (IBD) at the population level are limited in Asia. We aimed to investigate the nationwide prevalence and health-care cost and utilization of IBD in Korea. We tracked the IBD-attributable health-care costs and utilization from 2010 to 2014 using the public dataset obtained from Korean National Health Insurance Service claims. We estimated the nationwide prevalence of IBD using population census data from Statistics Korea during the same period. In total, 236 106 IBD patients were analyzed. The estimated IBD prevalence significantly increased from 85.1/100 000 in 2010 to 106/100 000 in 2014. The overall annual health-care costs for IBD increased from $23.2 million (US dollars) in 2010 to $49.7 million in 2014 (P < 0.001). During the same period, the health-care cost per capita also increased from $572.3 to $983.7 (P < 0.001). The outpatient to total cost ratio increased from 45.5% in 2010 to 66.6% in 2014. Regarding health-care utilization, the outpatient to total days of service use ratio increased from 73.1% in 2010 to 76.9% in 2014. Of the total days of service used, the proportions of tertiary, general, and community hospitals increased significantly with a concomitant decrease in that of primary clinics (all P values < 0.001). This population-based study confirmed the steadily rising rate of prevalence of IBD in Korea. It also demonstrated that the shifting to outpatient care and advanced care settings are drivers for the dramatic increase in IBD-related health-care costs in Korea. © 2017 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.
Jordan, Steve; Giersch, J. Joseph; Muhlfeld, Clint C.; Hotaling, Scott; Fanning, Liz; Tappenbeck, Tyler H.; Luikart, Gordon
2016-01-01
Much remains unknown about the genetic status and population connectivity of high-elevation and high-latitude freshwater invertebrates, which often persist near snow and ice masses that are disappearing due to climate change. Here we report on the conservation genetics of the meltwater stonefly Lednia tumana (Ricker) of Montana, USA, a cold-water obligate species. We sequenced 1530 bp of mtDNA from 116 L. tumana individuals representing “historic” (>10 yr old) and 2010 populations. The dominant haplotype was common in both time periods, while the second-most-common haplotype was found only in historic samples, having been lost in the interim. The 2010 populations also showed reduced gene and nucleotide diversity and increased genetic isolation. We found lower genetic diversity in L. tumana compared to two other North American stonefly species, Amphinemura linda (Ricker) and Pteronarcys californica Newport. Our results imply small effective sizes, increased fragmentation, limited gene flow, and loss of genetic variation among contemporary L. tumana populations, which can lead to reduced adaptive capacity and increased extinction risk. This study reinforces concerns that ongoing glacier loss threatens the persistence of L. tumana, and provides baseline data and analysis of how future environmental change could impact populations of similar organisms. PMID:27348125