Breast and ovarian cancer risks to carriers of the BRCA1 5382insC and 185delAG and BRCA2 6174delT mutations: a combined analysis of 22 population based studies

PubMed Central

Antoniou, A; Pharoah, P; Narod, S; Risch, H; Eyfjord, J; Hopper, J; Olsson, H; Johannsson, O; Borg, A; Pasini, B; Radice, P; Manoukian, S; Eccles, D; Tang, N; Olah, E; Anton-Culver, H; Warner, E; Lubinski, J; Gronwald, J; Gorski, B; Tulinius, H; Thorlacius, S; Eerola, H; Nevanlinna, H; Syrjakoski, K; Kallioniemi, O; Thompson, D; Evans, C; Peto, J; Lalloo, F; Evans, D; Easton, D

2005-01-01

A recent report estimated the breast cancer risks in carriers of the three Ashkenazi founder mutations to be higher than previously published estimates derived from population based studies. In an attempt to confirm this, the breast and ovarian cancer risks associated with the three Ashkenazi founder mutations were estimated using families included in a previous meta-analysis of populatrion based studies. The estimated breast cancer risks for each of the founder BRCA1 and BRCA2 mutations were similar to the corresponding estimates based on all BRCA1 or BRCA2 mutations in the meta-analysis. These estimates appear to be consistent with the observed prevalence of the mutations in the Ashkenazi Jewish population. PMID:15994883

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region.

PubMed

Ndumu, Deo B; Baumung, Roswitha; Hanotte, Olivier; Wurzinger, Maria; Okeyo, Mwai A; Jianlin, Han; Kibogo, Harrison; Sölkner, Johann

2008-01-01

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others.

A comparison of methods for calculating population exposure estimates of daily weather for health research.

PubMed

Hanigan, Ivan; Hall, Gillian; Dear, Keith B G

2006-09-13

To explain the possible effects of exposure to weather conditions on population health outcomes, weather data need to be calculated at a level in space and time that is appropriate for the health data. There are various ways of estimating exposure values from raw data collected at weather stations but the rationale for using one technique rather than another; the significance of the difference in the values obtained; and the effect these have on a research question are factors often not explicitly considered. In this study we compare different techniques for allocating weather data observations to small geographical areas and different options for weighting averages of these observations when calculating estimates of daily precipitation and temperature for Australian Postal Areas. Options that weight observations based on distance from population centroids and population size are more computationally intensive but give estimates that conceptually are more closely related to the experience of the population. Options based on values derived from sites internal to postal areas, or from nearest neighbour sites--that is, using proximity polygons around weather stations intersected with postal areas--tended to include fewer stations' observations in their estimates, and missing values were common. Options based on observations from stations within 50 kilometres radius of centroids and weighting of data by distance from centroids gave more complete estimates. Using the geographic centroid of the postal area gave estimates that differed slightly from the population weighted centroids and the population weighted average of sub-unit estimates. To calculate daily weather exposure values for analysis of health outcome data for small areas, the use of data from weather stations internal to the area only, or from neighbouring weather stations (allocated by the use of proximity polygons), is too limited. The most appropriate method conceptually is the use of weather data from sites within 50 kilometres radius of the area weighted to population centres, but a simpler acceptable option is to weight to the geographic centroid.

Disease outcome of inflammatory bowel disease patients: general outline of a Europe-wide population-based 10-year clinical follow-up study.

PubMed

Wolters, Frank L; Russel, Maurice G; Sijbrandij, Jildou; Schouten, Leo J; Odes, Selwyn; Riis, Lene; Munkholm, Pia; Langholz, Ebbe; Bodini, Paolo; O'Morain, Colm; Katsanos, Kostas; Tsianos, Epameinondas; Vermeire, Severine; Van Zeijl, Gilbert; Limonard, Charles; Hoie, Ole; Vatn, Morten; Moum, Bjørn; Stockbrügger, Reinhold W

2006-01-01

To give a general outline of a 10-year clinical follow-up study of a population-based European cohort of inflammatory bowel disease (IBD) patients and to present the first results in terms of clinical outcome parameters and risk factors. A population-based cohort of newly, prospectively, diagnosed cases was initiated between 1991 and 1993. The 2201 patients with IBD (706 had Crohn's disease (CD), 1379 had ulcerative colitis (UC) and 116 had indeterminate colitis) originated from 20 different areas in 11 different European countries and Israel. For the 10-year follow-up of this cohort, electronic data-collecting instruments were made available through an Internet-based website. Data concerning vital status, disease activity, medication use, surgical events, cancer, pregnancy, fertility, quality of life and health-care costs were gathered. A blood sample was obtained from patients and controls to perform genotypic characterization. Thirteen centres from eight European countries and Israel participated. In 958 (316 CD and 642 UC) out of a total of 1505 IBD patients (64%) from these 13 centres, a complete dataset was obtained at follow-up. Even though an increased mortality risk was observed in CD patients 10 years after diagnosis, a benign disease course was observed in this patient group in terms of disease recurrence. A correlation between ASCA and CARD15 variants in CD patients and complicated disease course was observed. A north-south gradient was observed regarding colectomy rates in UC patients. Direct costs were found to be highest in the first year after diagnosis and greater in CD patients than in UC patients, with marked differences between participating countries. This 10-year clinical follow-up study of a population-based European cohort of IBD patients provides updated information on disease outcome of these patient groups.

Costs of detection bias in index-based population monitoring

USGS Publications Warehouse

Moore, C.T.; Kendall, W.L.

2004-01-01

Managers of wildlife populations commonly rely on indirect, count-based measures of the population in making decisions regarding conservation, harvest, or control. The main appeal in the use of such counts is their low material expense compared to methods that directly measure the population. However, their correct use rests on the rarely-tested but often-assumed premise that they proportionately reflect population size, i.e., that they constitute a population index. This study investigates forest management for the endangered Red-cockaded Woodpecker (Picoides borealis) and the Wood Thrush (Hylocichla mustelina) at the Piedmont National Wildlife Refuge in central Georgia, U.S.A. Optimal decision policies for a joint species objective were derived for two alternative models of Wood Thrush population dynamics. Policies were simulated under scenarios of unbiasedness, consistent negative bias, and habitat-dependent negative bias in observed Wood Thrush densities. Differences in simulation outcomes between biased and unbiased detection scenarios indicated the expected loss in resource objectives (here, forest habitat and birds) through decision-making based on biased population counts. Given the models and objective function used in our analysis, expected losses were as great as 11%, a degree of loss perhaps not trivial for applications such as endangered species management. Our analysis demonstrates that costs of uncertainty about the relationship between the population and its observation can be measured in units of the resource, costs which may offset apparent savings achieved by collecting uncorrected population counts.

Population Genetic Structure of Apple Scab (Venturia inaequalis (Cooke) G. Winter) in Iran

PubMed Central

Ebrahimi, Leila; Fotuhifar, Khalil-Berdi; Javan Nikkhah, Mohammad; Naghavi, Mohammad-Reza; Baisakh, Niranjan

2016-01-01

The population genetic structure of 278 Venturia inaequalis isolates, collected from different apple cultivars of eighteen different provinces in Iran, was investigated using 22 polymorphic microsatellite markers. Analysis of molecular variation, Bayesian clustering and Nei's genetic distance analyses based on 88 microsatellite alleles indicated substantial levels of gene flow among the collection sites. Ninety three percent of the variation was observed among the individuals within the populations and only 7% variation was observed among the populations. Structure analysis grouped the isolates into two populations. Maximum number of pathogen genotypes (44) was observed in the North of Iran that grows various different apple cultivars. Investigation on the variation of the pathogen on different cultivars in the North of Iran suggested a significant differentiation of the pathogen populations between wild apple and commercial cultivars. During sampling, varying ranges of scab infection were observed on various apple cultivars in forests, monoculture and mix orchards. Wild type apple (Malus orientalis) along the Caspian Sea Coast had the most infection in comparison with the Iranian endemic and commercial cultivars. Based on the genetic analysis and host tracking scenario of the pathogen, it was presumed that Iran could potentially be the center of origin of V. inaequalis, which requires further detailed studies with isolates collected from different parts of central Asia and world for confirmation. PMID:27631622

Influence of exposure differences on city-to-city variations in PM2.5-mortality effect estimates

EPA Science Inventory

Multi-city population-based epidemiological studies have observed heterogeneity between city specific PM2.5-mortality effect estimates. One possibility is city-specific differences in overall population exposure to PM2.5. In a previous analysis we explored this latter point by cl...

Estimating abundance of an open population with an N-mixture model using auxiliary data on animal movements.

PubMed

Ketz, Alison C; Johnson, Therese L; Monello, Ryan J; Mack, John A; George, Janet L; Kraft, Benjamin R; Wild, Margaret A; Hooten, Mevin B; Hobbs, N Thompson

2018-04-01

Accurate assessment of abundance forms a central challenge in population ecology and wildlife management. Many statistical techniques have been developed to estimate population sizes because populations change over time and space and to correct for the bias resulting from animals that are present in a study area but not observed. The mobility of individuals makes it difficult to design sampling procedures that account for movement into and out of areas with fixed jurisdictional boundaries. Aerial surveys are the gold standard used to obtain data of large mobile species in geographic regions with harsh terrain, but these surveys can be prohibitively expensive and dangerous. Estimating abundance with ground-based census methods have practical advantages, but it can be difficult to simultaneously account for temporary emigration and observer error to avoid biased results. Contemporary research in population ecology increasingly relies on telemetry observations of the states and locations of individuals to gain insight on vital rates, animal movements, and population abundance. Analytical models that use observations of movements to improve estimates of abundance have not been developed. Here we build upon existing multi-state mark-recapture methods using a hierarchical N-mixture model with multiple sources of data, including telemetry data on locations of individuals, to improve estimates of population sizes. We used a state-space approach to model animal movements to approximate the number of marked animals present within the study area at any observation period, thereby accounting for a frequently changing number of marked individuals. We illustrate the approach using data on a population of elk (Cervus elaphus nelsoni) in Northern Colorado, USA. We demonstrate substantial improvement compared to existing abundance estimation methods and corroborate our results from the ground based surveys with estimates from aerial surveys during the same seasons. We develop a hierarchical Bayesian N-mixture model using multiple sources of data on abundance, movement and survival to estimate the population size of a mobile species that uses remote conservation areas. The model improves accuracy of inference relative to previous methods for estimating abundance of open populations. © 2018 by the Ecological Society of America.

[Kawasaki disease is more prevalent in rural areas of Catalonia (Spain)].

PubMed

Sánchez-Manubens, Judith; Antón, Jordi; Bou, Rosa; Iglesias, Estibaliz; Calzada-Hernandez, Joan; Rodó, Xavier; Morguí, Josep-Antón

2017-10-01

Kawasaki disease (KD) is an acute self-limited systemic vasculitis relatively common in childhood. The etiology of KD is still unknown, although clinical, laboratory and epidemiological features suggest an infectious origin or trigger. Differences on incidence between countries have been related to specific genetic factors, ethnicity, country of birth and some other sociocultural and environmental factors. We present a population-based study on incidence of KD in Catalonia (Spain), focusing on differences between patients in rural and non-rural areas of the region. Observational population-based study including all Pediatric Units in Catalan hospitals, between 2004 and 2014. A 12-month (March 2013-March 2014) prospective collection of new cases of KD was carried out to determine the incidence of KD. The rest of the data was retrieved retrospectively. Data from 399 patients over the 10-year study period was analyzed. Among the total KD patients, 353 (88.5%) lived in non-rural areas and 46 (11.5%) in rural areas. It was found that there is a significant difference (P<.001) between the percentage of rural population observed in patients with KD (11.5%), and the expected 5% of the Catalan population. This is the first population-based study showing significant differences on KD incidence rates between rural and non-rural areas. Copyright © 2016 Asociación Española de Pediatría. Publicado por Elsevier España, S.L.U. All rights reserved.

Fracture prediction and calibration of a Canadian FRAX® tool: a population-based report from CaMos

PubMed Central

Fraser, L.-A.; Langsetmo, L.; Berger, C.; Ioannidis, G.; Goltzman, D.; Adachi, J. D.; Papaioannou, A.; Josse, R.; Kovacs, C. S.; Olszynski, W. P.; Towheed, T.; Hanley, D. A.; Kaiser, S. M.; Prior, J.; Jamal, S.; Kreiger, N.; Brown, J. P.; Johansson, H.; Oden, A.; McCloskey, E.; Kanis, J. A.

2016-01-01

Summary A new Canadian WHO fracture risk assessment (FRAX®) tool to predict 10-year fracture probability was compared with observed 10-year fracture outcomes in a large Canadian population-based study (CaMos). The Canadian FRAX tool showed good calibration and discrimination for both hip and major osteoporotic fractures. Introduction The purpose of this study was to validate a new Canadian WHO fracture risk assessment (FRAX®) tool in a prospective, population-based cohort, the Canadian Multi-centre Osteoporosis Study (CaMos). Methods A FRAX tool calibrated to the Canadian population was developed by the WHO Collaborating Centre for Metabolic Bone Diseases using national hip fracture and mortality data. Ten-year FRAX probabilities with and without bone mineral density (BMD) were derived for CaMos women (N=4,778) and men (N=1,919) and compared with observed fracture outcomes to 10 years (Kaplan–Meier method). Cox proportional hazard models were used to investigate the contribution of individual FRAX variables. Results Mean overall 10-year FRAX probability with BMD for major osteoporotic fractures was not significantly different from the observed value in men [predicted 5.4% vs. observed 6.4% (95%CI 5.2–7.5%)] and only slightly lower in women [predicted 10.8% vs. observed 12.0% (95%CI 11.0–12.9%)]. FRAX was well calibrated for hip fracture assessment in women [predicted 2.7% vs. observed 2.7% (95%CI 2.2–3.2%)] but underestimated risk in men [predicted 1.3% vs. observed 2.4% (95%CI 1.7–3.1%)]. FRAX with BMD showed better fracture discrimination than FRAX without BMD or BMD alone. Age, body mass index, prior fragility fracture and femoral neck BMD were significant independent predictors of major osteoporotic fractures; sex, age, prior fragility fracture and femoral neck BMD were significant independent predictors of hip fractures. Conclusion The Canadian FRAX tool provides predictions consistent with observed fracture rates in Canadian women and men, thereby providing a valuable tool for Canadian clinicians assessing patients at risk of fracture. PMID:21161508

Sighting frequency and relative abundance of bottlenose dolphins (Tursiops truncatus) along the northeast coast of Margarita Island and Los Frailes Archipelago, Venezuela.

PubMed

Oviedo, Lenin; Silva, Noemi

2005-01-01

The study of local cetaceans in Venezuela has a very recent history, and few efforts have been made in the assessment of coastal populations based on field research. The occurrence of whales and dolphins along the northeast coast of Venezuela has been documented through sightings and stranding records. Given the underwater topographical features and the influence of upwelling processes, this area is considered a very productive coastal ecosystem. Our objective was to establish the sighting frequency and relative abundance of bottlenose dolphins in the area. Sighting records were gathered on bottlenose dolphins and other cetacean species occurring along the northeast coast of Margarita Island and Los Frailes Archipelago through direct observation during land-based (6 surveys, 48 hours of observation) and boat-based surveys (24 surveys, 121 hours of observation, 1295 km covered). A sighting frequency was calculated using two methodologies and then compared, considering: 1) a mean effective observation time (4.27 hours), and 2) distance covered with cetacean sightings (1108 kin). A third method is proposed relating a mean effective distance covered with cetacean sightings and expressed as a percentage. The abundance index was calculated using the mean effective observation time. The sighting frequency of Tursiops truncattus in the study area was 3 - 4 sightings per day of 4.27 observation hours, or by 185 kilometers covered. The relative abundance was calculated as 35 dolphins in the study area, so a total population of less than 60 dolphins could inhabit the proposed range. Tursiops truncatus is the dominant species in the northeast coast of Margarita Island and Los Frailes Archipelago with 70% of all the sightings, so this locality could be termed as the distribution range of a possible local population of bottlenose dolphins.

Demographic Variables for Wild Asian Elephants Using Longitudinal Observations

PubMed Central

de Silva, Shermin; Webber, C. Elizabeth; Weerathunga, U. S.; Pushpakumara, T. V.; Weerakoon, Devaka K.; Wittemyer, George

2013-01-01

Detailed demographic data on wild Asian elephants have been difficult to collect due to habitat characteristics of much of the species’ remaining range. Such data, however, are critical for understanding and modeling population processes in this endangered species. We present data from six years of an ongoing study of Asian elephants (Elephas maximus) in Uda Walawe National Park, Sri Lanka. This relatively undisturbed population numbering over one thousand elephants is individually monitored, providing cohort-based information on mortality and reproduction. Reproduction was seasonal, such that most births occurred during the long inter-monsoon dry season and peaked in May. During the study, the average age at first reproduction was 13.4 years and the 50th percentile inter-birth interval was approximately 6 years. Birth sex ratios did not deviate significantly from parity. Fecundity was relatively stable throughout the observed reproductive life of an individual (ages 11–60), averaging between 0.13–0.17 female offspring per individual per year. Mortalities and injuries based on carcasses and disappearances showed that males were significantly more likely than females to be killed or injured through anthropogenic activity. Overall, however, most observed injuries did not appear to be fatal. This population exhibits higher fecundity and density relative to published estimates on other Asian elephant populations, possibly enhanced by present range constriction. Understanding the factors responsible for these demographic dynamics can shed insight on the future needs of this elephant population, with probable parallels to other populations in similar settings. PMID:24376581

Demographic variables for wild Asian elephants using longitudinal observations.

PubMed

de Silva, Shermin; Webber, C Elizabeth; Weerathunga, U S; Pushpakumara, T V; Weerakoon, Devaka K; Wittemyer, George

2013-01-01

Detailed demographic data on wild Asian elephants have been difficult to collect due to habitat characteristics of much of the species' remaining range. Such data, however, are critical for understanding and modeling population processes in this endangered species. We present data from six years of an ongoing study of Asian elephants (Elephas maximus) in Uda Walawe National Park, Sri Lanka. This relatively undisturbed population numbering over one thousand elephants is individually monitored, providing cohort-based information on mortality and reproduction. Reproduction was seasonal, such that most births occurred during the long inter-monsoon dry season and peaked in May. During the study, the average age at first reproduction was 13.4 years and the 50(th) percentile inter-birth interval was approximately 6 years. Birth sex ratios did not deviate significantly from parity. Fecundity was relatively stable throughout the observed reproductive life of an individual (ages 11-60), averaging between 0.13-0.17 female offspring per individual per year. Mortalities and injuries based on carcasses and disappearances showed that males were significantly more likely than females to be killed or injured through anthropogenic activity. Overall, however, most observed injuries did not appear to be fatal. This population exhibits higher fecundity and density relative to published estimates on other Asian elephant populations, possibly enhanced by present range constriction. Understanding the factors responsible for these demographic dynamics can shed insight on the future needs of this elephant population, with probable parallels to other populations in similar settings.

Association of the oxytocin receptor (OXTR) gene polymorphisms with autism spectrum disorder (ASD) in the Japanese population.

PubMed

Liu, Xiaoxi; Kawamura, Yoshiya; Shimada, Takafumi; Otowa, Takeshi; Koishi, Shinko; Sugiyama, Toshiro; Nishida, Hisami; Hashimoto, Ohiko; Nakagami, Ryoichi; Tochigi, Mamoru; Umekage, Tadashi; Kano, Yukiko; Miyagawa, Taku; Kato, Nobumasa; Tokunaga, Katsushi; Sasaki, Tsukasa

2010-03-01

The oxytocin receptor (OXTR) gene, which is located on chromosome 3p25.3, has been implicated as a candidate gene for susceptibility of autism spectrum disorder (ASD). Positive associations between OXTR and ASD have been reported in earlier studies. However, the results were inconsistent and demand further studies. In this study, we investigated the associations between OXTR and ASD in a Japanese population by analyzing 11 single-nucleotide polymorphisms (SNPs) using both family-based association test (FBAT) and population-based case-control test. No significant signal was detected in the FBAT test. However, significant differences were observed in allelic frequencies of four SNPs, including rs2254298 between patients and controls. The risk allele of rs2254298 was 'A', which was consistent with the previous study in Chinese, and not with the observations in Caucasian. The difference in the risk allele of this SNP in previous studies might be attributable to an ethnic difference in the linkage disequilibrium structure between the Asians and Caucasians. In addition, haplotype analysis exhibits a significant association between a five-SNP haplotype and ASD, including rs22542898. In conclusion, our study might support that OXTR has a significant role in conferring the risk of ASD in the Japanese population.

Social network analysis of the genetic structure of Pacific islanders.

PubMed

Terrell, John Edward

2010-05-01

Social network analysis (SNA) is a body of theory and a set of relatively new computer-aided techniques used in the analysis and study of relational data. Recent studies of autosomal markers from over 40 human populations in the south-western Pacific have further documented the remarkable degree of genetic diversity in this part of the world. I report additional analysis using SNA methods contributing new controlled observations on the structuring of genetic diversity among these islanders. These SNA mappings are then compared with model-based network expectations derived from the geographic distances among the same populations. Previous studies found that genetic divergence among island Melanesian populations is organised by island, island size/topography, and position (coastal vs. inland), and that similarities observed correlate only weakly with an isolation-by-distance model. Using SNA methods, however, improves the resolution of among population comparison, and suggests that isolation by distance constrained by social networks together with position (coastal/inland) accounts for much of the population structuring observed. The multilocus data now available is also in accord with current thinking on the impact of major biogeographical transformations on prehistoric colonisation and post-settlement human interaction in Oceania.

The Low-Mass Stellar Content of the Scorpius-Centaurus OB Association

NASA Technical Reports Server (NTRS)

Yorke, H.; Kunkel, M.; Brander, W.; Zinnecker, H.; Neuhauser, R.; Schmitt, J.; Mayor, M.; Udry, S.

2000-01-01

Based on ROSAT observations and data obtained with ground-based telescopes, we have carried out an extensive study of the low-mass pre-main-sequence population in Upper Scorpius, the youngest subgroup of the Scorpius-Centaurus OB association.

Use of Mobile Device Data To Better Estimate Dynamic Population Size for Wastewater-Based Epidemiology.

PubMed

Thomas, Kevin V; Amador, Arturo; Baz-Lomba, Jose Antonio; Reid, Malcolm

2017-10-03

Wastewater-based epidemiology is an established approach for quantifying community drug use and has recently been applied to estimate population exposure to contaminants such as pesticides and phthalate plasticizers. A major source of uncertainty in the population weighted biomarker loads generated is related to estimating the number of people present in a sewer catchment at the time of sample collection. Here, the population quantified from mobile device-based population activity patterns was used to provide dynamic population normalized loads of illicit drugs and pharmaceuticals during a known period of high net fluctuation in the catchment population. Mobile device-based population activity patterns have for the first time quantified the high degree of intraday, week, and month variability within a specific sewer catchment. Dynamic population normalization showed that per capita pharmaceutical use remained unchanged during the period when static normalization would have indicated an average reduction of up to 31%. Per capita illicit drug use increased significantly during the monitoring period, an observation that was only possible to measure using dynamic population normalization. The study quantitatively confirms previous assessments that population estimates can account for uncertainties of up to 55% in static normalized data. Mobile device-based population activity patterns allow for dynamic normalization that yields much improved temporal and spatial trend analysis.

Epidemiology of haemolytic uremic syndrome in children. Data from the North Italian HUS network.

PubMed

Ardissino, Gianluigi; Salardi, Stefania; Colombo, Elisa; Testa, Sara; Borsa-Ghiringhelli, Nicolò; Paglialonga, Fabio; Paracchini, Valentina; Tel, Francesca; Possenti, Ilaria; Belingheri, Mirco; Civitillo, Cristina Felice; Sardini, Stefano; Ceruti, Rossella; Baldioli, Carlo; Tommasi, Paola; Parola, Luciana; Russo, Fiorella; Tedeschi, Silvana

2016-04-01

Despite the severity of HUS and the fact that it represents a leading cause of acute kidney injury in children, the general epidemiology of HUS is all but well documented. The present study provides updated, population-based, purely epidemiological information on HUS in childhood from a large and densely populated area of northern Italy (9.6 million inhabitants, 1.6 million children). We systematically reviewed the files concerning patients with STEC-HUS and atypical HUS (aHUS) over a 10-year observation period (January 2003-December 2012). We included all incident cases with a documented first episode of HUS before the age of 18 years. We identified 101 cases of HUS during the 10 years. The overall mean annual incidence was 6.3 cases/million children aged <18 years (range 1.9-11.9), and 15.7/million of age-related population (MARP) among subjects aged <5 years; aHUS accounted for 11.9 % of the cases (mean incidence 0.75/MARP). The overall case fatality rate was 4.0 % (3.4 % STEC-HUS, 8.3 % aHUS). Given the public health impact of HUS, this study provides recent, population-based epidemiological data useful for healthcare planning and particularly for estimating the financial burden that healthcare providers might have to face in treating HUS, whose incidence rate seems to increase in Northern Italy. • HUS is a rare disease, but it represents the leading cause of acute kidney injury in children worldwide. • STEC-HUS (also called typical, D + HUS) is more common compared to atypical HUS, but recent, population-based epidemiological data (incidence) are scanty. What is New: • Comprehensive, population-based epidemiological data concerning both typical and atypical HUS based on a long observational period.

Urban waterfowl population: Ecological evaluation of management and planning

NASA Astrophysics Data System (ADS)

Greer, David M.

1982-05-01

An urban population of ducks in Puyallup, Washington, USA was studied for 14 consecutive months beginning in November 1978. Observations were made weekly from four study sites where ducks would congregate at early morning hours. Factors contributing to the presence of waterfowl in Puyallyup included abundant food supplies and a creek corridor that connected fragmented habitats in the urban area to the larger rural populations of waterfowl. Mallards ( Anas platyrhynchos) were the most abundant of the 13 species observed and were the only ducks remaining during the nesting season. Habitat size and complexity were important factors influencing the species diversity of a particular site. Nesting success of mallards was poor due to limited distribution of nesting habitat, intraspecific aggression, and human disturbance. Both site-specific and more broad-based strategies are suggested for managing and planning for duck populations in urban areas.

Dementia Research: Populations, Progress, Problems, and Predictions.

PubMed

Hunter, Sally; Smailagic, Nadja; Brayne, Carol

2018-05-16

Alzheimer's disease (AD) is a clinicopathologically defined syndrome leading to cognitive impairment. Following the recent failures of amyloid-based randomized controlled trials to change the course of AD, there are growing calls for a re-evaluation of basic AD research. Epidemiology offers one approach to integrating the available evidence. Here we examine relationships between evidence from population-based, clinicopathological studies of brain aging and a range of hypotheses from all areas of AD research. We identify various problems, including a lack of systematic approach to measurement of clinical and neuropathological factors associated with dementia in experimental and clinical settings, poor understanding of the strengths and weaknesses of different observational and experimental designs, a lack of clarity in relation to disease definitions from the clinical, neuropathological, and molecular perspectives, inadequate characterization of brain aging in the human population, difficulties in translation between laboratory-based and population-based evidence bases, and a lack of communication between different sections of the dementia research community. Population studies highlight complexity and predict that therapeutic approaches based on single disease features will not be successful. Better characterization of brain aging in the human population is urgently required to select biomarkers and therapeutic targets that are meaningful to human disease. The generation of detailed and reliable evidence must be addressed before progress toward therapeutic interventions can be made.

[Genetic differentiation of Isaria farinosa populations in Anhui Province of East China].

PubMed

Sun, Zhao-Hong; Luan, Feng-Gang; Zhang, Da-Min; Chen, Ming-Jun; Wang, Bin; Li, Zeng-Zhi

2011-11-01

Isaria farinosa is an important entomopathogenic fungus. By using ISSR, this paper studied the genetic heterogeneity of six I. farinosa populations at different localities of Anhui Province, East China. A total of 98.5% polymorphic loci were amplified with ten polymorphic primers, but the polymorphism at population level varied greatly, within the range of 59.6%-93.2%. The genetic differentiation index (G(st)) between the populations based on Nei's genetic heterogenesis analysis was 0.3365, and the gene flow (N(m)) was 0.4931. The genetic differentiation between the populations was lower than that within the populations, suggesting that the genetic variation of I. farinosa mainly come from the interior of the populations. The UPGMA clustering based on the genetic similarities between the isolates revealed that the Xishan population was monophylectic, while the other five populations were polyphylectic, with the Yaoluoping population being the most heterogenic and the Langyashan population being the least heterogenic. No correlations were observed between the geographic distance and the genetic distance of the populations. According to the UPGMA clustering based on the genetic distance between the populations, the six populations were classified into three groups, and this classification was accorded with the clustering based on geographic environment, suggesting the effects of environmental heterogeneity on the population heterogeneity.

Polymorphic butterfly reveals the missing link in ecological speciation.

PubMed

Chamberlain, Nicola L; Hill, Ryan I; Kapan, Durrell D; Gilbert, Lawrence E; Kronforst, Marcus R

2009-11-06

Ecological speciation occurs when ecologically based, divergent selection causes the evolution of reproductive isolation. There are many empirical examples of this process; however, there exists a poorly characterized stage during which the traits that distinguish species ecologically and reproductively segregate in a single population. By using a combination of genetic mapping, mate-choice experiments, field observations, and population genetics, we studied a butterfly population with a mimetic wing color polymorphism and found that the butterflies exhibited partial, color-based, assortative mate preference. These traits represent the divergent, ecologically based signal and preference components of sexual isolation that usually distinguish incipient and sibling species. The association between behavior and recognition trait in a single population may enhance the probability of speciation and provides an example of the missing link between an interbreeding population and isolated species.

Genetic and morphological characterisation of the Ankole Longhorn cattle in the African Great Lakes region

PubMed Central

Ndumu, Deo B; Baumung, Roswitha; Hanotte, Olivier; Wurzinger, Maria; Okeyo, Mwai A; Jianlin, Han; Kibogo, Harrison; Sölkner, Johann

2008-01-01

The study investigated the population structure, diversity and differentiation of almost all of the ecotypes representing the African Ankole Longhorn cattle breed on the basis of morphometric (shape and size), genotypic and spatial distance data. Twentyone morphometric measurements were used to describe the morphology of 439 individuals from 11 sub-populations located in five countries around the Great Lakes region of central and eastern Africa. Additionally, 472 individuals were genotyped using 15 DNA microsatellites. Femoral length, horn length, horn circumference, rump height, body length and fore-limb circumference showed the largest differences between regions. An overall FST index indicated that 2.7% of the total genetic variation was present among sub-populations. The least differentiation was observed between the two sub-populations of Mbarara south and Luwero in Uganda, while the highest level of differentiation was observed between the Mugamba in Burundi and Malagarasi in Tanzania. An estimated membership of four for the inferred clusters from a model-based Bayesian approach was obtained. Both analyses on distance-based and model-based methods consistently isolated the Mugamba sub-population in Burundi from the others. PMID:18694545

Invited review: study design considerations for clinical research in veterinary radiology and radiation oncology.

PubMed

Scrivani, Peter V; Erb, Hollis N

2013-01-01

High quality clinical research is essential for advancing knowledge in the areas of veterinary radiology and radiation oncology. Types of clinical research studies may include experimental studies, method-comparison studies, and patient-based studies. Experimental studies explore issues relative to pathophysiology, patient safety, and treatment efficacy. Method-comparison studies evaluate agreement between techniques or between observers. Patient-based studies investigate naturally acquired disease and focus on questions asked in clinical practice that relate to individuals or populations (e.g., risk, accuracy, or prognosis). Careful preplanning and study design are essential in order to achieve valid results. A key point to planning studies is ensuring that the design is tailored to the study objectives. Good design includes a comprehensive literature review, asking suitable questions, selecting the proper sample population, collecting the appropriate data, performing the correct statistical analyses, and drawing conclusions supported by the available evidence. Most study designs are classified by whether they are experimental or observational, longitudinal or cross-sectional, and prospective or retrospective. Additional features (e.g., controlled, randomized, or blinded) may be described that address bias. Two related challenging aspects of study design are defining an important research question and selecting an appropriate sample population. The sample population should represent the target population as much as possible. Furthermore, when comparing groups, it is important that the groups are as alike to each other as possible except for the variables of interest. Medical images are well suited for clinical research because imaging signs are categorical or numerical variables that might be predictors or outcomes of diseases or treatments. © 2013 Veterinary Radiology & Ultrasound.

Expanding the Evidence Base: Comparing Randomized Controlled Trials and Observational Studies of Statins.

PubMed

Atar, Dan; Ong, Seleen; Lansberg, Peter J

2015-01-01

It is widely accepted that randomized controlled trials (RCTs) are the gold standard for demonstrating the efficacy of a given therapy (results under ideal conditions). Observational studies, on the other hand, can complement this by demonstrating effectiveness (results under real-world conditions). To examine the role that observational studies can play in complementing data from RCTs, we reviewed published studies for statins, a class of drugs that have been widely used to reduce the risk of cardiovascular (CV) events by lowering low-density lipoprotein cholesterol levels. RCTs have consistently demonstrated the benefits of statin treatment in terms of CV risk reduction and have demonstrated that more intensive statin therapy has incremental benefits over less intensive treatment. Observational studies of statin use in 'real-world' populations have served to augment the evidence base generated from statin RCTs in preselected populations of patients who are often at high CV risk and have led to similar safety and efficacy findings. They have also raised questions about factors affecting medication adherence, under-treatment, switching between statins, and failure to reach low-density lipoprotein cholesterol target levels, questions for which the answers could lead to improved patient care.

Comparison between Flow Cytometry and Traditional Culture Methods for Efficacy Assessment of Six Disinfectant Agents against Nosocomial Bacterial Species

PubMed Central

Massicotte, Richard; Mafu, Akier A.; Ahmad, Darakhshan; Deshaies, Francis; Pichette, Gilbert; Belhumeur, Pierre

2017-01-01

The present study was undertaken to compare the use of flow cytometry (FCM) and traditional culture methods for efficacy assessment of six disinfectants used in Quebec hospitals including: two quaternary ammonium-based, two activated hydrogen peroxide-based, one phenol-based, and one sodium hypochlorite-based. Four nosocomial bacterial species, Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Vancomycin-resistant Enterococci faecalis, were exposed to minimum lethal concentrations (MLCs) and sublethal concentrations (1/2 MLCs) of disinfectants under study. The results showed a strong correlation between the two techniques for the presence of dead and live cell populations, as well as, evidence of injured populations with the FCM. The only exception was observed with sodium hypochlorite at higher concentrations where fluorescence was diminished and underestimating dead cell population. The results also showed that FCM can replace traditional microbiological methods to study disinfectant efficacy on bacteria. Furthermore, FCM profiles for E. coli and E. faecalis cells exposed to sublethal concentrations exhibited distinct populations of injured cells, opening a new aspect for future research and investigation to elucidate the role of injured, cultural/noncuturable/resuscitable cell populations in infection control. PMID:28217115

Estimating canine cancer incidence: findings from a population-based tumour registry in northwestern Italy.

PubMed

Baioni, Elisa; Scanziani, Eugenio; Vincenti, Maria Claudia; Leschiera, Mauro; Bozzetta, Elena; Pezzolato, Marzia; Desiato, Rosanna; Bertolini, Silvia; Maurella, Cristiana; Ru, Giuseppe

2017-06-28

Canine cancer registry data can be put to good use in epidemiological studies. Quantitative comparison of tumour types may reveal unusual cancer frequencies, providing directions for research and generation of hypotheses of cancer causation in a specific area, and suggest leads for identifying risk factors. Here we report canine cancer incidence rates calculated from a population-based registry in an area without any known specific environmental hazard. In its 90 months of operation from 2001 to 2008 (the observation period in this study), the population-based Piedmont Canine Cancer Registry collected data on 1175 tumours confirmed by histopathological diagnosis. The incidence rate was 804 per 100,000 dog-years for malignant tumours and 897 per 100,000 dog-years for benign tumours. Higher rates for all cancers were observed in purebred dogs, particularly in Yorkshire terrier and Boxer. The most prevalent malignant neoplasms were cutaneous mastocytoma and hemangiopericytoma, and mammary gland complex carcinoma and simplex carcinoma. The Piedmont canine cancer registry is one of few of its kind whose operations have been consistently supported by long-term public funding. The registry-based cancer incidence rates were estimated with particular attention to the validity of data collection, thus minimizing the potential for bias. The findings on cancer incidence rates may provide a reliable reference for comparison studies. Researches conducted on dogs, used as sentinels for community exposure to environmental carcinogens, can be useful to detect excess risks in the incidence of malignant tumours in the human population.

Assessment of Visual Status of the Aeta, a Hunter-Gatherer Population of the Philippines (An AOS Thesis)

PubMed Central

Allingham, R. Rand

2008-01-01

Purpose A screening study was performed to assess levels of visual impairment and blindness among a representative sample of older members of the Aeta, an indigenous hunter-gatherer population living on the island of Luzon in the Philippines. Methods Unrelated older Aeta couples were randomly invited to participate in a visual screening study. All consented individuals had ocular history, medical history, complete ophthalmic examination, height, weight, and blood pressure taken. Results A total of 225 individuals were screened from 4 villages. Visual acuity, both uncorrected and pinhole corrected, was significantly worse among older vs younger age-groups for women, men, and when combined (P < .001). Visual impairment was present in 48% of uncorrected and 43% of pinhole corrected eyes in the oldest age-group. Six percent of the screened population was bilaterally blind. The major causes of blindness were readily treatable. The most common etiologies as a proportion of blind eyes were cataract (66%), refractive error (20%), and trauma (7%). No cases of primary open-angle, primary angle-closure, or exfoliation glaucoma were observed in this population. Discussion Visual impairment and blindness were common in the Aeta population. Primary forms of glaucoma, a major cause of blindness found in most population-based studies, were not observed. The absence of primary glaucoma in this population may reflect random sampling error. However, based on similar findings in the Australian Aborigine, this raises the possibility that these two similar populations may share genetic and/or environmental factors that are protective for glaucoma.. PMID:19277240

A Population-Based Approach to Study the Impact of PROP Perception on Food Liking in Populations along the Silk Road

PubMed Central

Robino, Antonietta; Mezzavilla, Massimo; Pirastu, Nicola; Dognini, Maddalena; Tepper, Beverly J.; Gasparini, Paolo

2014-01-01

Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3%) and Armenia (39.0%) and a higher frequency of non tasters in Georgia (50.9%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes. PMID:24626196

A population-based approach to study the impact of PROP perception on food liking in populations along the Silk Road.

PubMed

Robino, Antonietta; Mezzavilla, Massimo; Pirastu, Nicola; Dognini, Maddalena; Tepper, Beverly J; Gasparini, Paolo

2014-01-01

Taste is one of the main factors determining food choices. Differences in PROP bitter taste perception have been implicated in individual differences in food preferences and selection. The present study examined associations between, PROP phenotypes, self-reported food liking and TAS2R38 polymorphisms, the major gene implicated in PROP bitterness, in six different populations of the Caucasus and Central Asia, located along the ancient Silk Road. Differences in the distribution of PROP phenotypes across populations were detected, with a higher frequency of super tasters in Tajikistan (31.3%) and Armenia (39.0%) and a higher frequency of non tasters in Georgia (50.9%). While no relationships were observed between PROP phenotypes and food liking using standard statistical tests, we used an approach based on comparison of distance matrices derived from these data. The first matrix compared the food liking ratings of each population to all others pairwise using the Kruskal-Wallis test (at p<0.00063), and the second one compared the distribution of PROP phenotypes across all populations in a similar manner calculating the chi-square statistic as a distance measure. A strong correlation between the two matrices was found (Mantel test: r = 0.67, p-value = 0.03), suggesting that the pattern of food liking across populations was closely related to the distribution of PROP phenotypes. This same relationship was not observed when TAS2R38 genotypes were substituted for PROP phenotypes in this analysis. Our data suggest that a population-based approach utilizing distance matrices is a useful technique for detecting PROP-related differences in food liking and can be applied to other taste phenotypes.

Non-parametric estimation of population size changes from the site frequency spectrum.

PubMed

Waltoft, Berit Lindum; Hobolth, Asger

2018-06-11

Changes in population size is a useful quantity for understanding the evolutionary history of a species. Genetic variation within a species can be summarized by the site frequency spectrum (SFS). For a sample of size n, the SFS is a vector of length n - 1 where entry i is the number of sites where the mutant base appears i times and the ancestral base appears n - i times. We present a new method, CubSFS, for estimating the changes in population size of a panmictic population from an observed SFS. First, we provide a straightforward proof for the expression of the expected site frequency spectrum depending only on the population size. Our derivation is based on an eigenvalue decomposition of the instantaneous coalescent rate matrix. Second, we solve the inverse problem of determining the changes in population size from an observed SFS. Our solution is based on a cubic spline for the population size. The cubic spline is determined by minimizing the weighted average of two terms, namely (i) the goodness of fit to the observed SFS, and (ii) a penalty term based on the smoothness of the changes. The weight is determined by cross-validation. The new method is validated on simulated demographic histories and applied on unfolded and folded SFS from 26 different human populations from the 1000 Genomes Project.

Development of habitat suitability indices for the Candy Darter, with cross-scale validation across representative populations

USGS Publications Warehouse

Dunn, Corey G.; Angermeier, Paul

2016-01-01

Understanding relationships between habitat associations for individuals and habitat factors that limit populations is a primary challenge for managers of stream fishes. Although habitat use by individuals can provide insight into the adaptive significance of selected microhabitats, not all habitat parameters will be significant at the population level, particularly when distributional patterns partially result from habitat degradation. We used underwater observation to quantify microhabitat selection by an imperiled stream fish, the Candy Darter Etheostoma osburni, in two streams with robust populations. We developed multiple-variable and multiple-life-stage habitat suitability indices (HSIs) from microhabitat selection patterns and used them to assess the suitability of available habitat in streams where Candy Darter populations were extirpated, localized, or robust. Next, we used a comparative framework to examine relationships among (1) habitat availability across streams, (2) projected habitat suitability of each stream, and (3) a rank for the likely long-term viability (robustness) of the population inhabiting each stream. Habitat selection was characterized by ontogenetic shifts from the low-velocity, slightly embedded areas used by age-0 Candy Darters to the swift, shallow areas with little fine sediment and complex substrate, which were used by adults. Overall, HSIs were strongly correlated with population rank. However, we observed weak or inverse relationships between predicted individual habitat suitability and population robustness for multiple life stages and variables. The results demonstrated that microhabitat selection by individuals does not always reflect population robustness, particularly when based on a single life stage or season, which highlights the risk of generalizing habitat selection that is observed during nonstressful periods or for noncritical resources. These findings suggest that stream fish managers may need to be cautious when implementing conservation measures based solely on observations of habitat selection by individuals and that detailed study at the individual and population levels may be necessary to identify habitat that limits populations.

Science deficiency in conservation practice: the monitoring of tiger populations in India

USGS Publications Warehouse

Karanth, K.U.; Nichols, J.D.; Seidensticker, J.; Dinerstein, Eric; Smith, J.L.D.; McDougal, C.; Johnsingh, A.J.T.; Chundawat, Raghunandan S.; Thapar, V.

2003-01-01

Conservation practices are supposed to get refined by advancing scientific knowledge. We study this phenomenon in the context of monitoring tiger populations in India, by evaluating the 'pugmark census method' employed by wildlife managers for three decades. We use an analytical framework of modem animal population sampling to test the efficacy of the pugmark censuses using scientific data on tigers and our field observations. We identify three critical goals for monitoring tiger populations, in order of increasing sophistication: (1) distribution mapping, (2) tracking relative abundance, (3) estimation of absolute abundance. We demonstrate that the present census-based paradigm does not work because it ignores the first two simpler goals, and targets, but fails to achieve, the most difficult third goal. We point out the utility and ready availability of alternative monitoring paradigms that deal with the central problems of spatial sampling and observability. We propose an alternative sampling-based approach that can be tailored to meet practical needs of tiger monitoring at different levels of refinement.

Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers

PubMed Central

Garzón-Martínez, Gina A.; Osorio-Guarín, Jaime A.; Delgadillo-Durán, Paola; Mayorga, Franklin; Enciso-Rodríguez, Felix E.; Landsman, David

2015-01-01

The genus Physalis is common in the Americas and includes several economically important species, among them Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNPs) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation FST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies. PMID:26550601

Genetic diversity and population structure in Physalis peruviana and related taxa based on InDels and SNPs derived from COSII and IRG markers.

PubMed

Garzón-Martínez, Gina A; Osorio-Guarín, Jaime A; Delgadillo-Durán, Paola; Mayorga, Franklin; Enciso-Rodríguez, Felix E; Landsman, David; Mariño-Ramírez, Leonardo; Barrero, Luz Stella

2015-12-01

The genus Physalis is common in the Americas and includes several economically important species, among them Physalis peruviana that produces appetizing edible fruits. We studied the genetic diversity and population structure of P. peruviana and characterized 47 accessions of this species along with 13 accessions of related taxa consisting of 222 individuals from the Colombian Corporation of Agricultural Research (CORPOICA) germplasm collection, using Conserved Orthologous Sequences (COSII) and Immunity Related Genes (IRGs). In addition, 642 Single Nucleotide Polymorphism (SNPs) markers were identified and used for the genetic diversity analysis. A total of 121 alleles were detected in 24 InDels loci ranging from 2 to 9 alleles per locus, with an average of 5.04 alleles per locus. The average number of alleles in the SNP markers was two. The observed heterozygosity for P. peruviana with InDel and SNP markers was higher (0.48 and 0.59) than the expected heterozygosity (0.30 and 0.41). Interestingly, the observed heterozygosity in related taxa (0.4 and 0.12) was lower than the expected heterozygosity (0.59 and 0.25). The coefficient of population differentiation F ST was 0.143 (InDels) and 0.038 (SNPs), showing a relatively low level of genetic differentiation among P. peruviana and related taxa. Higher levels of genetic variation were instead observed within populations based on the AMOVA analysis. Population structure analysis supported the presence of two main groups and PCA analysis based on SNP markers revealed two distinct clusters in the P. peruviana accessions corresponding to their state of cultivation. In this study, we identified molecular markers useful to detect genetic variation in Physalis germplasm for assisting conservation and crossbreeding strategies.

Treatment intensification without improved HbA1c levels in children and adolescents with Type 1 diabetes mellitus.

PubMed

Sildorf, S M; Hertel, N T; Thomsen, J; Fredheim, S; Hastrup, H; Pipper, C; Hertz, B; Svensson, J

2016-04-01

To examine trends in diabetes treatment in Danish children and adolescents with Type 1 diabetes mellitus, comparing treatment intensity with metabolic outcomes in the population, and to describe the challenges of population-based registries in a clinical setting with rapidly changing treatment methods. This observational study is based on the Danish national population registry of childhood diabetes, which includes 99% of children diagnosed with Type 1 diabetes before the age of 15 years. We included 4527 people diagnosed between 2000 and 2012. Self-monitored blood glucose measurements, insulin injections/boluses, treatment method and metabolic control quantifications were analysed and adjusted for the effects of gender and ethnicity, the combined effect of age, visit year and duration, and for the random effects of individual and hospital settings. Treatment was intensified via an increasing number of self-monitored blood glucose measurements and injections/boluses. More than six injections/boluses and an increased number of self-monitored blood glucose measurements were significantly associated with lower metabolic control. No reduction, however, in the overall mean HbA1c concentration was observed between 2005 [66 mmol/mol (8.2%)] and 2012 [65 mmol/mol (8.1%)]. Changed registration practices in 2009 introduced artificial jumps in data. Intensifying treatment alone does not lead to improved metabolic control in the overall population despite the appearance of lower HbA1c in individuals with a greater number of self-monitored blood glucose measurements and injections/boluses. The contradictory results reflect difficulties in using observational studies to predict results of intervention in the individual. Data collected from population-based registries need to be adjusted continuously to reflect changes in care. © 2015 Diabetes UK.

Cost-effectiveness of rituximab as maintenance treatment for relapsed follicular lymphoma: results of a population-based study.

PubMed

Blommestein, Hedwig M; Issa, Djamila E; Pompen, Marjolein; Ten Hoor, Gerhard; Hogendoorn, Mels; Joosten, Peter; Zweegman, Sonja; Huijgens, Peter C; Uyl-de Groot, Carin A

2014-01-01

On the basis of two population-based registries, our study aims to calculate the real-world cost-effectiveness of rituximab maintenance compared with observation in relapsed or refractory follicular lymphoma patients who responded to second-line chemotherapy. Data were obtained from the EORTC20981 trial, the Netherlands Cancer Registry and two population-based registries. A Markov model was developed to calculate cost per life year gained (LYG) and quality-adjusted life years (QALYs) for three scenarios. Our real-world patients were (62 years) 6 to 7 years older and had higher complete response rates to second-line chemotherapy than the trial population. Differences between the real-world rituximab and observation group were observed for second-line chemotherapy and disease progression. Groups were more balanced after using propensity matching. Relying entirely on updated trial results (scenario1) in combination with local cost data resulted in ratios of €11,259 per LYG and €12,655 per QALY. For scenario2, consisting of trial efficacy and matched real-world costs, ratios of €21,202 per LYG and €23,821 per QALY were calculated. Using real-world matched evidence (scenario3) for both effectiveness and costs showed ratios of €10,591 per LYG and €11,245 per QALY. Although differences in real-world and trial population were found, using real-world data as well as results from long-term trial follow-up showed favourable ICERs for rituximab maintenance. Nevertheless, results showed that caution is required with data synthesis, interpretation and generalisability of results. As different scenarios provide answers to different questions, we recommend healthcare decision-makers to recognise the importance of calculating several cost-effectiveness scenarios. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hybridization among Arctic white-headed gulls (Larus spp.) obscures the genetic legacy of the Pleistocene

USGS Publications Warehouse

Sonsthagen, Sarah A.; Chesser, R. Terry; Bell, Douglas A.; Dove, Carla J.

2012-01-01

We studied the influence of glacial oscillations on the genetic structure of seven species of white-headed gull that breed at high latitudes (Larus argentatus, L. canus, L. glaucescens, L. glaucoides, L. hyperboreus, L. schistisagus, and L. thayeri). We evaluated localities hypothesized as ice-free areas or glacial refugia in other Arctic vertebrates using molecular data from 11 microsatellite loci, mitochondrial DNA (mtDNA) control region, and six nuclear introns for 32 populations across the Holarctic. Moderate levels of genetic structure were observed for microsatellites (FST= 0.129), introns (ΦST= 0.185), and mtDNA control region (ΦST= 0.461), with among-group variation maximized when populations were grouped based on subspecific classification. Two haplotype and at least two allele groups were observed across all loci. However, no haplotype/allele group was composed solely of individuals of a single species, a pattern consistent with recent divergence. Furthermore, northernmost populations were not well differentiated and among-group variation was maximized when L. argentatus and L. hyberboreus populations were grouped by locality rather than species, indicating recent hybridization. Four populations are located in putative Pleistocene glacial refugia and had larger t estimates than the other 28 populations. However, we were unable to substantiate these putative refugia using coalescent theory, as all populations had genetic signatures of stability based on mtDNA. The extent of haplotype and allele sharing among Arctic white-headed gull species is noteworthy. Studies of other Arctic taxa have generally revealed species-specific clusters as well as genetic structure within species, usually correlated with geography. Aspects of white-headed gull behavioral biology, such as colonization ability and propensity to hybridize, as well as their recent evolutionary history, have likely played a large role in the limited genetic structure observed.

Evaluation of type 2 diabetes genetic risk variants in Chinese adults: findings from 93,000 individuals from the China Kadoorie Biobank.

PubMed

Gan, Wei; Walters, Robin G; Holmes, Michael V; Bragg, Fiona; Millwood, Iona Y; Banasik, Karina; Chen, Yiping; Du, Huaidong; Iona, Andri; Mahajan, Anubha; Yang, Ling; Bian, Zheng; Guo, Yu; Clarke, Robert J; Li, Liming; McCarthy, Mark I; Chen, Zhengming

2016-07-01

Genome-wide association studies (GWAS) have discovered many risk variants for type 2 diabetes. However, estimates of the contributions of risk variants to type 2 diabetes predisposition are often based on highly selected case-control samples, and reliable estimates of population-level effect sizes are missing, especially in non-European populations. The individual and cumulative effects of 59 established type 2 diabetes risk loci were measured in a population-based China Kadoorie Biobank (CKB) study of 93,000 Chinese adults, including >7,100 diabetes cases. Association signals were directionally consistent between CKB and the original discovery GWAS: of 56 variants passing quality control, 48 showed the same direction of effect (binomial test, p = 2.3 × 10(-8)). We observed a consistent overall trend towards lower risk variant effect sizes in CKB than in case-control samples of GWAS meta-analyses (mean 19-22% decrease in log odds, p ≤ 0.0048), likely to reflect correction of both 'winner's curse' and spectrum bias effects. The association with risk of diabetes of a genetic risk score, based on lead variants at 25 loci considered to act through beta cell function, demonstrated significant interactions with several measures of adiposity (BMI, waist circumference [WC], WHR and percentage body fat [PBF]; all p interaction < 1 × 10(-4)), with a greater effect being observed in leaner adults. Our study provides further evidence of shared genetic architecture for type 2 diabetes between Europeans and East Asians. It also indicates that even very large GWAS meta-analyses may be vulnerable to substantial inflation of effect size estimates, compared with those observed in large-scale population-based cohort studies. Details of how to access China Kadoorie Biobank data and details of the data release schedule are available from www.ckbiobank.org/site/Data+Access .

Geographical distance and local environmental conditions drive the genetic population structure of a freshwater microalga (Bathycoccaceae; Chlorophyta) in Patagonian lakes.

PubMed

Fernández, Leonardo D; Hernández, Cristián E; Schiaffino, M Romina; Izaguirre, Irina; Lara, Enrique

2017-10-01

The patterns and mechanisms underlying the genetic structure of microbial populations remain unresolved. Herein we investigated the role played by two non-mutually exclusive models (i.e. isolation by distance and isolation by environment) in shaping the genetic structure of lacustrine populations of a microalga (a freshwater Bathycoccaceae) in the Argentinean Patagonia. To our knowledge, this was the first study to investigate the genetic population structure in a South American microorganism. Population-level analyses based on ITS1-5.8S-ITS2 sequences revealed high levels of nucleotide and haplotype diversity within and among populations. Fixation index and a spatially explicit Bayesian analysis confirmed the occurrence of genetically distinct microalga populations in Patagonia. Isolation by distance and isolation by environment accounted for 38.5% and 17.7% of the genetic structure observed, respectively, whereas together these models accounted for 41% of the genetic differentiation. While our results highlighted isolation by distance and isolation by environment as important mechanisms in driving the genetic population structure of the microalga studied, none of these models (either alone or together) could explain the entire genetic differentiation observed. The unexplained variation in the genetic differentiation observed could be the result of founder events combined with rapid local adaptations, as proposed by the monopolisation hypothesis. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Is the Definition of Roma an Important Matter? The Parallel Application of Self and External Classification of Ethnicity in a Population-Based Health Interview Survey.

PubMed

Janka, Eszter Anna; Vincze, Ferenc; Ádány, Róza; Sándor, János

2018-02-16

The Roma population is typified by a poor and, due to difficulties in ethnicity assessment, poorly documented health status. We aimed to compare the usefulness of self-reporting and observer-reporting in Roma classification for surveys investigating differences between Roma and non-Roma populations. Both self-reporting and observer-reporting of Roma ethnicity were applied in a population-based health interview survey. A questionnaire was completed by 1849 people aged 18-64 years; this questionnaire provided information on 52 indicators (morbidity, functionality, lifestyle, social capital, accidents, healthcare use) indicators. Multivariate logistic regression models controlling for age, sex, education and employment were used to produce indicators for differences between the self-reported Roma ( N = 124) and non-Roma ( N = 1725) populations, as well as between observer-reported Roma ( N = 179) and non-Roma populations ( N = 1670). Differences between interviewer-reported and self-reported individuals of Roma ethnicity in statistical inferences were observed for only seven indicators. The self-reporting approach was more sensitive for two indicators, and the observer-reported assessment for five indicators. Based on our results, the self-reported identity can be considered as a useful approach, and the application of observer-reporting cannot considerably increase the usefulness of a survey, because the differences between Roma and non-Roma individuals are much bigger than the differences between indicators produced by self-reported or observer-reported data on individuals of Roma ethnicity.

An introduction to medical statistics for health care professionals: Hypothesis tests and estimation.

PubMed

Thomas, Elaine

2005-01-01

This article is the second in a series of three that will give health care professionals (HCPs) a sound introduction to medical statistics (Thomas, 2004). The objective of research is to find out about the population at large. However, it is generally not possible to study the whole of the population and research questions are addressed in an appropriate study sample. The next crucial step is then to use the information from the sample of individuals to make statements about the wider population of like individuals. This procedure of drawing conclusions about the population, based on study data, is known as inferential statistics. The findings from the study give us the best estimate of what is true for the relevant population, given the sample is representative of the population. It is important to consider how accurate this best estimate is, based on a single sample, when compared to the unknown population figure. Any difference between the observed sample result and the population characteristic is termed the sampling error. This article will cover the two main forms of statistical inference (hypothesis tests and estimation) along with issues that need to be addressed when considering the implications of the study results. Copyright (c) 2005 Whurr Publishers Ltd.

Reliability of Total Test Scores When Considered as Ordinal Measurements

ERIC Educational Resources Information Center

Biswas, Ajoy Kumar

2006-01-01

This article studies the ordinal reliability of (total) test scores. This study is based on a classical-type linear model of observed score (X), true score (T), and random error (E). Based on the idea of Kendall's tau-a coefficient, a measure of ordinal reliability for small-examinee populations is developed. This measure is extended to large…

Integrating data from multiple sources for insights into demographic processes: Simulation studies and proof of concept for hierarchical change-in-ratio models.

PubMed

Nilsen, Erlend B; Strand, Olav

2018-01-01

We developed a model for estimating demographic rates and population abundance based on multiple data sets revealing information about population age- and sex structure. Such models have previously been described in the literature as change-in-ratio models, but we extend the applicability of the models by i) using time series data allowing the full temporal dynamics to be modelled, by ii) casting the model in an explicit hierarchical modelling framework, and by iii) estimating parameters based on Bayesian inference. Based on sensitivity analyses we conclude that the approach developed here is able to obtain estimates of demographic rate with high precision whenever unbiased data of population structure are available. Our simulations revealed that this was true also when data on population abundance are not available or not included in the modelling framework. Nevertheless, when data on population structure are biased due to different observability of different age- and sex categories this will affect estimates of all demographic rates. Estimates of population size is particularly sensitive to such biases, whereas demographic rates can be relatively precisely estimated even with biased observation data as long as the bias is not severe. We then use the models to estimate demographic rates and population abundance for two Norwegian reindeer (Rangifer tarandus) populations where age-sex data were available for all harvested animals, and where population structure surveys were carried out in early summer (after calving) and late fall (after hunting season), and population size is counted in winter. We found that demographic rates were similar regardless whether we include population count data in the modelling, but that the estimated population size is affected by this decision. This suggest that monitoring programs that focus on population age- and sex structure will benefit from collecting additional data that allow estimation of observability for different age- and sex classes. In addition, our sensitivity analysis suggests that focusing monitoring towards changes in demographic rates might be more feasible than monitoring abundance in many situations where data on population age- and sex structure can be collected.

Can changes in population mixing and socio-economic deprivation in Cumbria, England explain changes in cancer incidence around Sellafield?

PubMed

McNally, Richard J Q; James, Peter W; Blakey, Karen; Basta, Nermine O; Norman, Paul D; Pearce, Mark S

2017-06-01

Previously excesses in incident cases of leukaemia and non-Hodgkin lymphoma have been observed amongst young people born or resident in Seascale, Cumbria. These excesses have not been seen more recently. It is postulated that the former apparent increased risk was related to 'unusual population mixing', which is not present in recent years. This study investigated changes in measures of population mixing from 1951-2001. Comparisons were made between three specified areas. Area-based measures were calculated (migration, commuting, deprivation, population density). All areas have become more affluent, although Seascale was consistently the most affluent. Seascale has become less densely populated, with less migration into the ward and less diversity with respect to migrants' origin. There have been marked changes in patterns of population mixing throughout Cumbria. Lesser population mixing has been observed in Seascale in recent decades. Changes in pattern and nature of population mixing may explain the lack of recent excesses. Copyright © 2017 Elsevier Ltd. All rights reserved.

Significant increase in the apparent incidence of essential thrombocythemia related to new WHO diagnostic criteria: a population-based study

PubMed Central

Girodon, François; Bonicelli, Gilles; Schaeffer, Céline; Mounier, Morgane; Carillo, Serge; Lafon, Ingrid; Carli, Paule Marie; Janoray, Inès; Ferrant, Emmanuelle; Maynadié, Marc

2009-01-01

To observe the effect of the new World Health Organization (WHO) criteria on the incidence of myeloproliferative neoplasms, we performed a retrospective study of a population-based registry in the Côte d’Or area, France, from 1980 to 2007. A total of 524 myeloproliferative neoplasms were registered for the 1980–2007 period, including 135 polycythemia vera, 308 essential thrombocythemia and 81 idiopathic myelofibroses. No change in the incidence of either polycythemia vera or idiopathic myelofibrosis was observed for the 2005–2007 period, compared to 1980–2004. On the contrary, a pronounced increase in the incidence of essential thrombocythemia was noted after 2005, mainly due to the use of JAK2 mutation screening and a lower threshold of platelet count. Our study confirms the relevance of the new WHO diagnostic criteria in allowing earlier diagnosis of essential thrombocythemia. PMID:19377078

Long-Term Associations of Childhood Suicide Ideation

ERIC Educational Resources Information Center

Herba, Catherine M.; Ferdinand, Robert F.; van der Ende, Jan; Verhulst, Frank C.

2007-01-01

A population-based study examined whether suicide ideation in childhood adversely affects mental health in adulthood. It was observed that childhood suicide ideation could lead to worrying mental health consequences in adulthood.

The Solid Rocket Motor Slag Population: Results of a Radar-Based Regressive Statistical Evaluation

NASA Technical Reports Server (NTRS)

Horstman, Matthew F.; Xu, Yu-Lin

2008-01-01

Solid rocket motor (SRM) slag has been identified as a potential source of man-made orbital debris. The possibility that SRMs (in addition to generating dust particles in the sub-millimeter range) may generate particles up to centimeters in size has caused concern regarding their contribution to the debris environment. Returned surfaces from space do not have sufficient area or exposure time to provide a clear picture of the SRM millimeter and centimeter debris population. Currently, radar observation is probably the only way to collect data showing the debris contribution from SRMs. Such observation is used to sample the debris environment, but it is difficult to obtain accurate orbital elements for the detected debris objects. NASA has developed several models to describe the different orbital debris populations, based on assumed debris production mechanisms to create clouds of debris objects that can be propagated in time. The NASA model, LEGEND (LEO-to-GEO Environment Debris), functions as a time-tested debris model for most debris sources. However, the current LEGEND model does not include contributions from the SRM population. An SRM model has recently been developed by NASA, based on purely theoretical details of SRM production and known SRM launches, but verification with hard data is needed. Because the detections of individual SRM objects cannot be deterministically separated from the total debris observed by radar, the validation of the SRM model can only be done by combining it with the LEGEND breakup model and comparing it with data. By applying observational constraints, the degree of SRM slag contribution to the environment may be estimated. This serves as an observationally sound method from which to calibrate a purely theoretical model into something more realistic. For this study, we use the populations observed by the Haystack radar from 1996 to present. For the SRM debris, we use a historical database of SRM launches, propellant masses, and estimated locations and times of tailoff to produce and propagate the SRM debris clouds. Comparisons with radar data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the populations estimated from the data. The result is a model SRM population that fits within the bounds of the observed environment and estimates of the production and contribution of SRM debris to the environment.

Long-term observations of Boreal Toads at an ARMI apex site

USGS Publications Warehouse

Corn, Paul Stephen; Muths, Erin L.; Pilliod, David S.

2011-01-01

The U.S. Geological Survey’s Amphibian Research and Monitoring Initiative (ARMI) is a national project with goals to monitor the status and trends of amphibians, conduct research on causes of declines, and provide information and support to management agencies for conservation of amphibian populations. ARMI activities are organized around extensive inventories and place-based monitoring (such as collaboration with the Greater Yellowstone Inventory and Monitoring Network), and intensive population studies and research at selected locations (apex sites). One such site is an oxbow pond on the Buffalo Fork near the Black Rock Ranger Station east of Grand Teton National Park. We have been conducting mark-recapture of boreal toads (Anaxyrus boreas) at Black Rock since 2002. In concert with studies of other toad populations in the Rocky Mountains, we have documented a high rate of incidence of the chytrid fungus Batrachochytrium dendrobatidis (Bd) and a negative rate of growth of the toad population, but not the population crash or extinction observed in other populations with high prevalence of Bd. Long-term observations at other ARMI apex sites have proven invaluable for studying effects of climate change on amphibian behavior, and the Black Rock site has been upgraded with onsite recording of weather data and auditory monitoring of other amphibian species. Continued research at Black Rock will be critical for understanding the interrelated effects of climate and disease on amphibians in the Greater Yellowstone Ecosystem.

Assessing interethnic admixture using an X-linked insertion-deletion multiplex.

PubMed

Ribeiro-Rodrigues, Elzemar Martins; dos Santos, Ney Pereira Carneiro; dos Santos, Andrea Kely Campos Ribeiro; Pereira, Rui; Amorim, António; Gusmão, Leonor; Zago, Marco Antonio; dos Santos, Sidney Emanuel Batista

2009-01-01

In this study, a PCR multiplex was optimized, allowing the simultaneous analysis of 13 X-chromosome Insertion/deletion polymorphisms (INDELs). Genetic variation observed in Africans, Europeans, and Native Americans reveals high inter-population variability. The estimated proportions of X-chromosomes in an admixed population from the Brazilian Amazon region show a predominant Amerindian contribution (approximately 41%), followed by European (approximately 32%) and African (approximately 27%) contributions. The proportion of Amerindian contribution based on X-linked data is similar to the expected value based on mtDNA and Y-chromosome information. The accuracy for assessing interethnic admixture, and the high differentiation between African, European, and Native American populations, demonstrates the suitability of this INDEL set to measure ancestry proportions in three-hybrid populations, as it is the case of Latin American populations.

Genetic variation and population structure in Jamunapari goats using microsatellites, mitochondrial DNA, and milk protein genes.

PubMed

Rout, P K; Thangraj, K; Mandal, A; Roy, R

2012-01-01

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed.

Genetic Variation and Population Structure in Jamunapari Goats Using Microsatellites, Mitochondrial DNA, and Milk Protein Genes

PubMed Central

Rout, P. K.; Thangraj, K.; Mandal, A.; Roy, R.

2012-01-01

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed. PMID:22606053

Injury risk functions based on population-based finite element model responses: Application to femurs under dynamic three-point bending.

PubMed

Park, Gwansik; Forman, Jason; Kim, Taewung; Panzer, Matthew B; Crandall, Jeff R

2018-02-28

The goal of this study was to explore a framework for developing injury risk functions (IRFs) in a bottom-up approach based on responses of parametrically variable finite element (FE) models representing exemplar populations. First, a parametric femur modeling tool was developed and validated using a subject-specific (SS)-FE modeling approach. Second, principal component analysis and regression were used to identify parametric geometric descriptors of the human femur and the distribution of those factors for 3 target occupant sizes (5th, 50th, and 95th percentile males). Third, distributions of material parameters of cortical bone were obtained from the literature for 3 target occupant ages (25, 50, and 75 years) using regression analysis. A Monte Carlo method was then implemented to generate populations of FE models of the femur for target occupants, using a parametric femur modeling tool. Simulations were conducted with each of these models under 3-point dynamic bending. Finally, model-based IRFs were developed using logistic regression analysis, based on the moment at fracture observed in the FE simulation. In total, 100 femur FE models incorporating the variation in the population of interest were generated, and 500,000 moments at fracture were observed (applying 5,000 ultimate strains for each synthesized 100 femur FE models) for each target occupant characteristics. Using the proposed framework on this study, the model-based IRFs for 3 target male occupant sizes (5th, 50th, and 95th percentiles) and ages (25, 50, and 75 years) were developed. The model-based IRF was located in the 95% confidence interval of the test-based IRF for the range of 15 to 70% injury risks. The 95% confidence interval of the developed IRF was almost in line with the mean curve due to a large number of data points. The framework proposed in this study would be beneficial for developing the IRFs in a bottom-up manner, whose range of variabilities is informed by the population-based FE model responses. Specifically, this method mitigates the uncertainties in applying empirical scaling and may improve IRF fidelity when a limited number of experimental specimens are available.

From blackbirds to black holes: Investigating capture-recapture methods for time domain astronomy

NASA Astrophysics Data System (ADS)

Laycock, Silas G. T.

2017-07-01

In time domain astronomy, recurrent transients present a special problem: how to infer total populations from limited observations. Monitoring observations may give a biassed view of the underlying population due to limitations on observing time, visibility and instrumental sensitivity. A similar problem exists in the life sciences, where animal populations (such as migratory birds) or disease prevalence, must be estimated from sparse and incomplete data. The class of methods termed Capture-Recapture is used to reconstruct population estimates from time-series records of encounters with the study population. This paper investigates the performance of Capture-Recapture methods in astronomy via a series of numerical simulations. The Blackbirds code simulates monitoring of populations of transients, in this case accreting binary stars (neutron star or black hole accreting from a stellar companion) under a range of observing strategies. We first generate realistic light-curves for populations of binaries with contrasting orbital period distributions. These models are then randomly sampled at observing cadences typical of existing and planned monitoring surveys. The classical capture-recapture methods, Lincoln-Peterson, Schnabel estimators, related techniques, and newer methods implemented in the Rcapture package are compared. A general exponential model based on the radioactive decay law is introduced which is demonstrated to recover (at 95% confidence) the underlying population abundance and duty cycle, in a fraction of the observing visits (10-50%) required to discover all the sources in the simulation. Capture-Recapture is a promising addition to the toolbox of time domain astronomy, and methods implemented in R by the biostats community can be readily called from within python.

Genetic variation and forensic characteristic analysis of 25 STRs of a novel fluorescence co-amplification system in Chinese Southern Shaanxi Han population.

PubMed

Liu, Yao-Shun; Chen, Jian-Gang; Mei, Ting; Guo, Yu-Xin; Meng, Hao-Tian; Li, Jian-Fei; Wei, Yuan-Yuan; Jin, Xiao-Ye; Zhu, Bo-Feng; Zhang, Li-Ping

2017-08-15

We analyzed the genetic polymorphisms of 15 autosomal and 10 Y-chromosomal STR loci in 214 individuals of Han population from Southern Shaanxi of China and studied the genetic relationships between Southern Shaanxi Han and other populations. We observed a total of 150 alleles at 15 autosomal STR loci with the corresponding allelic frequencies ranging from 0.0023 to 0.5210, and the combined power of discrimination and exclusion for the 15 autosomal STR loci were 0.99999999999999998866 and 0.999998491, respectively. For the 10 Y-STR loci, totally 100 different haplotypes were obtained, of which 94 were unique. The discriminatory capacity and haplotype diversity values of the 10 Y-STR loci were 0.9259 and 0.998269, respectively. The results demonstrated high genetic diversities of the 25 STR loci in the population for forensic applications. We constructed neighbor-joining tree and conducted principal component analysis based on 15 autosomal STR loci and conducted multidimensional scaling analysis and constructed neighbor-joining tree based on 10 Y-STR loci. The results of population genetic analyses based on both autosomal and Y-chromosome STRs indicated that the studied Southern Shaanxi Han population had relatively closer genetic relationship with Eastern Han population, and distant relationships with Croatian, Serbian and Moroccan populations.

THE HUBBLE SPACE TELESCOPE UV LEGACY SURVEY OF GALACTIC GLOBULAR CLUSTERS: THE INTERNAL KINEMATICS OF THE MULTIPLE STELLAR POPULATIONS IN NGC 2808

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellini, A.; Anderson, J.; Marel, R. P. van der

2015-09-01

Numerous observational studies have revealed the ubiquitous presence of multiple stellar populations in globular clusters and cast many difficult challenges for the study of the formation and dynamical history of these stellar systems. In this Letter we present the results of a study of the kinematic properties of multiple populations in NGC 2808 based on high-precision Hubble Space Telescope proper-motion measurements. In a recent study, Milone et al. identified five distinct populations (A–E) in NGC 2808. Populations D and E coincide with the helium-enhanced populations in the middle and the blue main sequences (mMS and bMS) previously discovered by Piottomore » et al.; populations A–C correspond to the redder main sequence that, in Piotto et al., was associated with the primordial stellar population. Our analysis shows that, in the outermost regions probed (between about 1.5 and 2 times the cluster half-light radius), the velocity distribution of populations D and E is radially anisotropic (the deviation from an isotropic distribution is significant at the ∼3.5σ level). Stars of populations D and E have a smaller tangential velocity dispersion than those of populations A–C, while no significant differences are found in the radial velocity dispersion. We present the results of a numerical simulation showing that the observed differences between the kinematics of these stellar populations are consistent with the expected kinematic fingerprint of the diffusion toward the cluster outer regions of stellar populations initially more centrally concentrated.« less

Disease introduction is associated with a phase transition in bighorn sheep demographics

PubMed Central

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul Chafee; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (lambda =1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (lambda = 0.98) over the next twenty years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. PMID:27859120

Disease introduction is associated with a phase transition in bighorn sheep demographics

USGS Publications Warehouse

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul C.; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles.

CDPOP: A spatially explicit cost distance population genetics program

Treesearch

Erin L. Landguth; S. A. Cushman

2010-01-01

Spatially explicit simulation of gene flow in complex landscapes is essential to explain observed population responses and provide a foundation for landscape genetics. To address this need, we wrote a spatially explicit, individual-based population genetics model (CDPOP). The model implements individual-based population modelling with Mendelian inheritance and k-allele...

Hospice care in a commercial preferred provider organization population in Tennessee.

PubMed

Coulter, Steven L; Melvin, Terry; Carden, J Payne; Mathis, Rick S

2015-03-01

This study was undertaken to examine two aspects of care at the end of life. First, we wanted to see whether the cost savings demonstrated repeatedly in the US Medicare hospice population would also be observed in a commercial population in Tennessee. They were. The second primary interest we had was whether there were certain medical services that seemed to presage death. We found four categories of services that profoundly increase in number as the end of life is approached: primary care, hospital-based specialist, non-hospital based specialist, and oncologist services. It is hoped that these findings could lead to a simple predictive model based on readily available claims data to help identify candidates for Hospice Care earlier. © The Author(s) 2013.

Stellar population in star formation regions of galaxies

NASA Astrophysics Data System (ADS)

Gusev, Alexander S.; Shimanovskaya, Elena V.; Shatsky, Nikolai I.; Sakhibov, Firouz; Piskunov, Anatoly E.; Kharchenko, Nina V.

2018-05-01

We developed techniques for searching young unresolved star groupings (clusters, associations, and their complexes) and of estimating their physical parameters. Our study is based on spectroscopic, spectrophotometric, and UBVRI photometric observations of 19 spiral galaxies. In the studied galaxies, we found 1510 objects younger than 10 Myr and present their catalogue. Having combined photometric and spectroscopic data, we derived extinctions, chemical abundances, sizes, ages, and masses of these groupings. We discuss separately the specific cases, when the gas extinction does not agree with the interstellar one. We assume that this is due to spatial offset of Hii clouds with respect to the related stellar population.We developed a method to estimate age of stellar population of the studied complexes using their morphology and the relation with associated H emission region. In result we obtained the estimates of chemical abundances for 80, masses for 63, and ages for 57 young objects observed in seven galaxies.

Comparison of outcomes after use of biphasic or monophasic defibrillators among out-of-hospital cardiac arrest patients: a nationwide population-based observational study.

PubMed

Tanabe, Seizan; Yasunaga, Hideo; Ogawa, Toshio; Koike, Soichi; Akahane, Manabu; Horiguchi, Hiromasa; Hatanaka, Tetsuo; Yokota, Hiroyuki; Imamura, Tomoaki

2012-09-01

The use and popularity of the biphasic waveform defibrillator as a replacement for the monophasic waveform defibrillator are increasing, but it is unclear whether this can improve the rate of survival among out-of-hospital cardiac arrest patients. This study aimed to verify the hypothesis that the outcome of out-of-hospital cardiac arrest patients who received defibrillation shock with the biphasic waveform defibrillator was better than that of patients who received defibrillation shock with the monophasic defibrillator. This prospective, nationwide, population-based, observational study included 21 172 out-of-hospital cardiac arrest patients with initial ventricular fibrillation or pulseless ventricular tachycardia from January 1, 2005, through December 31, 2007. Defibrillation shock was performed by monophasic defibrillator on 8224 (39%) patients and by biphasic defibrillator on 12 948 (61%) patients. The rate of survival at 1 month with minimal neurological impairment was 11.6% (951/8192) in the monophasic defibrillator group and 12.8% (1653/12 928) in the biphasic defibrillator group. Hierarchical logistic regression analysis using a generalized estimation equation showed no significant difference between the biphasic and monophasic groups in 1-month survival with minimal neurological impairment (adjusted odds ratio, 1.07; 95% confidence interval, 0.91-1.26; P=0.42). Confirmatory propensity score analyses showed similar results. Although monophasic defibrillators are being replaced by biphasic defibrillators, our nationwide population-based observational study failed to demonstrate a statistically significant association between defibrillation waveform and 1-month survival rate with minimal neurological impairment.

Inheritance of Mesotrione Resistance in an Amaranthus tuberculatus (var. rudis) Population from Nebraska, USA

PubMed Central

Oliveira, Maxwel C.; Gaines, Todd A.; Jhala, Amit J.; Knezevic, Stevan Z.

2018-01-01

A population of Amaranthus tuberculatus (var. rudis) evolved resistance to 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor herbicides (mesotrione, tembotrione, and topramezone) in Nebraska. The level of resistance was the highest to mesotrione, and the mechanism of resistance in this population is metabolism-based likely via cytochrome P450 enzymes. The increasing number of weeds resistant to herbicides warrants studies on the ecology and evolutionary factors contributing for resistance evolution, including inheritance of resistance traits. In this study, we investigated the genetic control of mesotrione resistance in an A. tuberculatus population from Nebraska, USA. Results showed that reciprocal crosses in the F1 families exhibited nuclear inheritance, which allows pollen movement carrying herbicide resistance alleles. The mode of inheritance varied from incomplete recessive to incomplete dominance depending upon the F1 family. Observed segregation patterns for the majority of the F2 and back-cross susceptible (BC/S) families did not fit to a single major gene model. Therefore, multiple genes are likely to confer metabolism-based mesotrione resistance in this A. tuberculatus population from Nebraska. The results of this study aid to understand the genetics and inheritance of a non-target-site based mesotrione resistant A. tuberculatus population from Nebraska, USA. PMID:29456544

An integrated modeling approach to estimating Gunnison Sage-Grouse population dynamics: combining index and demographic data.

USGS Publications Warehouse

Davis, Amy J.; Hooten, Mevin B.; Phillips, Michael L.; Doherty, Paul F.

2014-01-01

Evaluation of population dynamics for rare and declining species is often limited to data that are sparse and/or of poor quality. Frequently, the best data available for rare bird species are based on large-scale, population count data. These data are commonly based on sampling methods that lack consistent sampling effort, do not account for detectability, and are complicated by observer bias. For some species, short-term studies of demographic rates have been conducted as well, but the data from such studies are typically analyzed separately. To utilize the strengths and minimize the weaknesses of these two data types, we developed a novel Bayesian integrated model that links population count data and population demographic data through population growth rate (λ) for Gunnison sage-grouse (Centrocercus minimus). The long-term population index data available for Gunnison sage-grouse are annual (years 1953–2012) male lek counts. An intensive demographic study was also conducted from years 2005 to 2010. We were able to reduce the variability in expected population growth rates across time, while correcting for potential small sample size bias in the demographic data. We found the population of Gunnison sage-grouse to be variable and slightly declining over the past 16 years.

Mediterranean Diet and Cardiometabolic Diseases in Racial/Ethnic Minority Populations in the United States

PubMed Central

Sotos-Prieto, Mercedes; Mattei, Josiemer

2018-01-01

The Mediterranean diet (MedDiet) has been recommended to the general population by many scientific organizations as a healthy dietary pattern, based on strong evidence of association with improved cardiometabolic health, including lower risk of cardiovascular disease, diabetes, and obesity. However, most studies have been conducted in Mediterranean or European countries or among white populations in the United States (US), while few exist for non-Mediterranean countries or racial/ethnic minority populations in the US. Because most existing studies evaluating adherence to the MedDiet use population-specific definitions or scores, the reported associations may not necessarily apply to other racial/ethnic populations that may have different distributions of intake. Moreover, racial/ethnic groups may have diets that do not comprise the typical Mediterranean foods captured by these scores. Thus, there is a need to determine if similar positive effects from following a MedDiet are observed in diverse populations, as well as to identify culturally-relevant foods reflected within Mediterranean-like patterns, that can facilitate implementation and promotion of such among broader racial/ethnic groups. In this narrative review, we summarize and discuss the evidence from observational and intervention studies on the MedDiet and cardiometabolic diseases in racial/ethnic minority populations in the US, and offer recommendations to enhance research on MedDiet for such populations. PMID:29538339

Mediterranean Diet and Cardiometabolic Diseases in Racial/Ethnic Minority Populations in the United States.

PubMed

Sotos-Prieto, Mercedes; Mattei, Josiemer

2018-03-14

The Mediterranean diet (MedDiet) has been recommended to the general population by many scientific organizations as a healthy dietary pattern, based on strong evidence of association with improved cardiometabolic health, including lower risk of cardiovascular disease, diabetes, and obesity. However, most studies have been conducted in Mediterranean or European countries or among white populations in the United States (US), while few exist for non-Mediterranean countries or racial/ethnic minority populations in the US. Because most existing studies evaluating adherence to the MedDiet use population-specific definitions or scores, the reported associations may not necessarily apply to other racial/ethnic populations that may have different distributions of intake. Moreover, racial/ethnic groups may have diets that do not comprise the typical Mediterranean foods captured by these scores. Thus, there is a need to determine if similar positive effects from following a MedDiet are observed in diverse populations, as well as to identify culturally-relevant foods reflected within Mediterranean-like patterns, that can facilitate implementation and promotion of such among broader racial/ethnic groups. In this narrative review, we summarize and discuss the evidence from observational and intervention studies on the MedDiet and cardiometabolic diseases in racial/ethnic minority populations in the US, and offer recommendations to enhance research on MedDiet for such populations.

A NEO population generation and observation simulation software tool

NASA Astrophysics Data System (ADS)

Müller, Sven; Gelhaus, Johannes; Hahn, Gerhard; Franco, Raffaella

One of the main targets of ESA's Space Situational Awareness (SSA) program is to build a wide knowledge base about objects that can potentially harm Earth (Near-Earth Objects, NEOs). An important part of this effort is to create the Small Bodies Data Centre (SBDC) which is going to aggregate measurement data from a fully-integrated NEO observation sensor network. Until this network is developed, artificial NEO measurement data is needed in order to validate SBDC algorithms. Moreover, to establish a functioning NEO observation sensor network, it has to be determined where to place sensors, what technical requirements have to be met in order to be able to detect NEOs and which observation strategies work the best. Because of this, a sensor simulation software was needed. This paper presents a software tool which allows users to create and analyse NEO populations and to simulate and analyse population observations. It is a console program written in Fortran and comes with a Graphical User Interface (GUI) written in Java and C. The tool can be distinguished into the components ``Population Generator'' and ``Observation Simulator''. The Population Generator component is responsible for generating and analysing a NEO population. Users can choose between creating fictitious (random) and synthetic populations. The latter are based on one of two models describing the orbital and size distribution of observed NEOs: The existing socalled ``Bottke Model'' (Bottke et al. 2000, 2002) and the new ``Granvik Model'' (Granvik et al. 2014, in preparation) which has been developed in parallel to the tool. Generated populations can be analysed by defining 2D, 3D and scatter plots using various NEO attributes. As a result, the tool creates the appropiate files for the plotting tool ``gnuplot''. The tool's Observation Simulator component yields the Observation Simulation and Observation Analysis functions. Users can define sensor systems using ground- or space-based locations as well as optical or radar sensors and simulate observation campaigns. The tool outputs field-of-view crossings and actual detections of the selected NEO population objects. Using the Observation Analysis users are able to process and plot the results of the Observation Simulation. In order to enable end-users to handle the tool in a user-intuitive and comfortable way, a GUI has been created based on the modular Eclipse Rich Client Platform (RCP) technology. Through the GUI users can easily enter input data for the tool, execute it and view its output data in a clear way. Additionally, the GUI runs gnuplot to create plot pictures and presents them to the user. Furthermore, users can create projects to organise executions of the tool.

Geographical and ethnic variability of finger ridge-counts: biplots of male and female Indian samples.

PubMed

Krishnan, T; Reddy, B M

1994-01-01

The graphical technique of biplot due to Gabriel and others is explained, and is applied to ten finger ridge-count means of 239 populations, mostly Indian. The biplots, together with concentration ellipses based on them, are used to study geographical, gender and ethnic/social group variability, to compare Indian populations with other populations and to study relations between individual counts and populations. The correlation structure of ridge-counts exhibits a tripartite division of digits demonstrated by many other studies, but with a somewhat different combination of digits. Comparisons are also made with the results of Leguebe and Vrydagh, who used principal components, discriminant functions, Andrews functions, etc., to study geographical and gender variations. There is a great deal of homogeneity in Indian populations when compared to populations from the rest of the world. Although broad geographical contiguity is reflected in the biplots, local (states within India) level contiguity is not maintained. Monogoloids and Caucasoids have distinct ridge-count structures. The higher level of homogeneity in females and on the left side observed by Leguebe and Vrydagh is also observed in the biplots. A comparison with principal component plots indicates that biplots yield a graphical representation similar to component plots, and convey more information than component plots.

Participation in population-based case-control studies: does the observed decline vary by socio-economic status?

PubMed

Mazloum, Marie; Bailey, Helen D; Heiden, Tamika; Armstrong, Bruce K; de Klerk, Nicholas; Milne, Elizabeth

2012-05-01

An Australian study of childhood leukaemia (Aus-ALL) previously reported that control participation was positively associated with socio-economic status (SES). A similar study of childhood brain tumours (Aus-CBT) was carried out 4 years later, and this paper compares control participation and its relationship with SES in the two studies. To assess the representativeness of controls in terms of SES, the addresses of controls were linked to Australian Bureau of Statistics Census 2006 Collection Districts (CDs), and hence to area-based indices of SES. Independent sample t-tests and chi-squared tests were used to compare the SES indices of CDs where Aus-CBT controls lived with those where Aus-ALL controls lived and with those of all CDs where Australian families lived. The overall percentage of eligible families who agreed to participate was lower in Aus-CBT (53.9%) than in Aus-ALL (70.3%). Control families in both studies were of higher SES than the general population, while the distribution of SES among recruited controls was similar in both studies. These findings provide some reassurance that the observed decline in research participation over time may not be associated with an increasingly unrepresentative participant population. © 2012 Blackwell Publishing Ltd.

Understanding the use of emergency department and urgent care services by diabetic patients of a Family Medicine Health Team: a retrospective observational study.

PubMed

Ward, Matthew

2017-03-01

Aim To understand the frequency, urgency, and rationale of emergency department and urgent care (ED/UC) use by diabetic patients of a Family Medicine Health Team (FHT). A retrospective, observational study with comparison control groups was conducted from 1 January 2013 to 31 December 2014. A total of 693 diabetic patients were compared with two, age-standardized non-diabetic groups: one with a higher disease burden based on International Classification of Diseases 9 diagnoses and the other from a randomized patient pool. Findings The diabetic group utilized ED/UC services 1.25 and 1.92 times more often than the two control populations, consistent with that observed in other studies. Canadian Triage and Acuity Scale scores were essentially the same for the diabetic population. Only 3.1% of visits were for diabetic related emergencies, in contrast to the expected 23% by surveyed physicians of the FHT. Diabetic patient's sought treatment for cellulitis, wounds, abscesses, and infections more often than the control populations.

Population genetic structure of rare and endangered plants using molecular markers

USGS Publications Warehouse

Raji, Jennifer; Atkinson, Carter T.

2013-01-01

This study was initiated to assess the levels of genetic diversity and differentiation in the remaining populations of Phyllostegia stachyoides and Melicope zahlbruckneri in Hawai`i Volcanoes National Park and determine the extent of gene flow to identify genetically distinct individuals or groups for conservation purposes. Thirty-six Amplified Fragment Length Polymorphic (AFLP) primer combinations generated a total of 3,242 polymorphic deoxyribonucleic acid (DNA) fragments in the P. stachyoides population with a percentage of polymorphic bands (PPB) ranging from 39.3 to 65.7% and 2,780 for the M. zahlbruckneri population with a PPB of 18.8 to 64.6%. Population differentiation (Fst) of AFLP loci between subpopulations of P. stachyoides was low (0.043) across populations. Analysis of molecular variance of P. stachyoides showed that 4% of the observed genetic differentiation occurred between populations in different kīpuka and 96% when individuals were pooled from all kīpuka. Moderate genetic diversity was detected within the M. zahlbruckneri population. Bayesian and multivariate analyses both classified the P. stachyoides and M. zahlbruckneri populations into genetic groups with considerable sub-structuring detected in the P. stachyoides population. The proportion of genetic differentiation among populations explained by geographical distance was estimated by Mantel tests. No spatial correlation was found between genetic and geographic distances in both populations. Finally, a moderate but significant gene flow that could be attributed to insect or bird-mediated dispersal of pollen across the different kīpuka was observed. The results of this study highlight the utility of a multi-allelic DNA-based marker in screening a large number of polymorphic loci in small and closely related endangered populations and revealed the presence of genetically unique groups of individuals in both M. zahlbruckneri and P. stachyoides populations. Based on these findings, approaches that can assist conservation efforts of these species are proposed. 

Cognitive Correlates of Functional Abilities in Individuals with Mild Cognitive Impairment: Comparison of Questionnaire, Direct Observation and Performance-based Measures

PubMed Central

Schmitter-Edgecombe, Maureen; Parsey, Carolyn M.

2014-01-01

The relationship between and the cognitive correlates of several proxy measures of functional status were studied in a population with mild cognitive impairment (MCI). Participants were 51 individuals diagnosed with MCI and 51 cognitively healthy older adults (OA). Participants completed performance-based functional status tests, standardized neuropsychological tests, and performed eight activities of daily living (e.g., watered plants, filled medication dispenser) while under direct observation in a campus apartment. An informant interview about everyday functioning was also conducted. Compared to the OA control group, the MCI group performed more poorly on all proxy measures of everyday functioning. The informant-report of instrumental activities of daily living (IADL) did not correlate with the two performance-based measures; however, both the informant-report IADL and the performance-based everyday problem-solving test correlated with the direct observation measure. After controlling for age and education, cognitive predictors did not explain a significant amount of variance in the performance-based measures; however, performance on a delayed memory task was a unique predictor for the informant-report IADL, and processing speed predicted unique variance for the direct observation score. These findings indicate that differing methods for evaluating functional status are not assessing completely overlapping aspects of everyday functioning in the MCI population. PMID:24766574

Cognitive correlates of functional abilities in individuals with mild cognitive impairment: comparison of questionnaire, direct observation, and performance-based measures.

PubMed

Schmitter-Edgecombe, Maureen; Parsey, Carolyn M

2014-01-01

The relationship between, and the cognitive correlates of, several proxy measures of functional status were studied in a population with mild cognitive impairment (MCI). Participants were 51 individuals diagnosed with MCI and 51 cognitively healthy older adults (OA). Participants completed performance-based functional status tests and standardized neuropsychological tests, and performed eight activities of daily living (e.g., watered plants, filled medication dispenser) while under direct observation in a campus apartment. An informant interview about everyday functioning was also conducted. Compared to the OA control group, the MCI group performed more poorly on all proxy measures of everyday functioning. The informant report of instrumental activities of daily living (IADL) did not correlate with the two performance-based measures; however, both the informant-report IADL and the performance-based everyday problem-solving test correlated with the direct observation measure. After controlling for age and education, cognitive predictors did not explain a significant amount of variance in the performance-based measures; however, performance on a delayed memory task was a unique predictor for the informant-report IADL, and processing speed predicted unique variance for the direct observation score. These findings indicate that differing methods for evaluating functional status are not assessing completely overlapping aspects of everyday functioning in the MCI population.

Harvesting, predation and competition effects on a red coral population

NASA Astrophysics Data System (ADS)

Abbiati, M.; Buffoni, G.; Caforio, G.; Di Cola, G.; Santangelo, G.

A Corallium rubrum population, dwelling in the Ligurian Sea, has been under observation since 1987. Biometric descriptors of colonies (base diameter, weight, number of polyps, number of growth rings) have been recorded and correlated. The population size structure was obtained by distributing the colonies into diameter classes, each size class representing the average annual increment of diameter growth. The population was divided into ten classes, including a recruitment class. This size structure showed a fairly regular trend in the first four classes. The irregularity of survival in the older classes agreed with field observations on harvesting and predation. Demographic parameters such as survival, growth plasticity and natality coefficients were estimated from the experimental data. On this basis a discrete nonlinear model was implemented. The model is based on a kind of density-dependent Leslie matrix, where the feedback term only occurs in survival of the first class; the recruitment function is assumed to be dependent on the total biomass and related to inhibiting effects due to competitive interactions. Stability analysis was applied to steady-state solutions. Numerical simulations of population evolution were carried out under different conditions. The dynamics of settlement and the effects of disturbances such as harvesting, predation and environmental variability were studied.

SCORE should be preferred to Framingham to predict cardiovascular death in French population.

PubMed

Marchant, Ivanny; Boissel, Jean-Pierre; Kassaï, Behrouz; Bejan, Theodora; Massol, Jacques; Vidal, Chrystelle; Amsallem, Emmanuel; Naudin, Florence; Galan, Pilar; Czernichow, Sébastien; Nony, Patrice; Gueyffier, François

2009-10-01

Numerous studies have examined the validity of available scores to predict the absolute cardiovascular risk. We developed a virtual population based on data representative of the French population and compared the performances of the two most popular risk equations to predict cardiovascular death: Framingham and SCORE. A population was built based on official French demographic statistics and summarized data from representative observational studies. The 10-year coronary and cardiovascular death risk and their ratio were computed for each individual by SCORE and Framingham equations. The resulting rates were compared with those derived from national vital statistics. Framingham overestimated French coronary deaths by 2.8 in men and 1.9 in women, and cardiovascular deaths by 1.5 in men and 1.3 in women. SCORE overestimated coronary death by 1.6 in men and 1.7 in women, and underestimated cardiovascular death by 0.94 in men and 0.85 in women. Our results revealed an exaggerated representation of coronary among cardiovascular death predicted by Framingham, with coronary death exceeding cardiovascular death in some individual profiles. Sensitivity analyses gave some insights to explain the internal inconsistency of the Framingham equations. Evidence is that SCORE should be preferred to Framingham to predict cardiovascular death risk in French population. This discrepancy between prediction scores is likely to be observed in other populations. To improve the validation of risk equations, specific guidelines should be issued to harmonize the outcomes definition across epidemiologic studies. Prediction models should be calibrated for risk differences in the space and time dimensions.

Game On: Past Year Gambling, Gambling-Related Problems, and Fantasy Sports Gambling Among College Athletes and Non-athletes.

PubMed

Martin, Ryan J; Nelson, Sarah E; Gallucci, Andrew R

2016-06-01

College students experience higher rates of gambling-related problems than most other population segments, including the general population. Although Division I (D1) athletes often have more at stake than the average student if and when they gamble (e.g., the potential to lose their athletic eligibility), relatively few studies have assessed the gambling behavior of this population and none have specifically assessed fantasy sports gambling. We conducted a study to examine gambling behavior (past-year gambling, gambling-related problems, and fantasy sport gambling) among a sample (N = 692) of college students at a private religiously affiliated university in the Southwest US. The sample for our study was unique in that approximately 30 % of the participants were D1 athletes. We compared the gambling behavior among three groups based on the athlete status: D1 athletes, club/intramural/recreational (CIR) athletes, and non-athletes (NAs). Compared to females in our sample, males observed higher rates of past year gambling, fantasy sports participation, fantasy sports gambling, and gambling-related problems. Among males, we found that CIR athletes observed the highest rates of past year gambling and fantasy sports participation and D1 athletes observed higher rates than NAs. We did not find differences in fantasy sport gambling and past year gambling-related problems based on athlete status in males or females.

Long-term observation of amphibian populations inhabiting urban and forested areas in Yekaterinburg, Russia

NASA Astrophysics Data System (ADS)

Vershinin, Vladimir L.; Vershinina, Svetlana D.; Berzin, Dmitry L.; Zmeeva, Darya V.; Kinev, Alexander V.

2015-05-01

This article presents data derived from a 36 year-long uninterrupted observational study of amphibian populations living in the city and vicinity of Yekaterinburg, Russia. This area is inhabited by six amphibian species. Based on a degree of anthropogenic transformation, the urban territory is divided into five highly mosaic zones characterized by vegetation, temperature, and a distinctive water pollution profile. Population data is presented year-by-year for the number of animals, sex ratio, and species-specific fecundity including the number and quality of spawns for the following amphibian species: Salamandrella keyserligii, Rana arvalis, R. temporaria, Lissotriton vulgaris, and Pelophylax ridibundus. These data provide an excellent opportunity to assess an urban environment from an animal population-wide perspective, as well as revealing the forces driving animal adaptation to the anthropogenic transformation of habitats.

Chloroplast DNA Diversity among Trees, Populations and Species in the California Closed-Cone Pines (Pinus Radiata, Pinus Muricata and Pinus Attenuata)

PubMed Central

Hong, Y. P.; Hipkins, V. D.; Strauss, S. H.

1993-01-01

The amount, distribution and mutational nature of chloroplast DNA polymorphisms were studied via analysis of restriction fragment length polymorphisms in three closely related species of conifers, the California closed-cone pines-knobcone pine: Pinus attenuata Lemm.; bishop pine: Pinus muricata D. Don; and Monterey pine: Pinus radiata D. Don. Genomic DNA from 384 trees representing 19 populations were digested with 9-20 restriction enzymes and probed with cloned cpDNA fragments from Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] that comprise 82% of the chloroplast genome. Up to 313 restriction sites were surveyed, and 25 of these were observed to be polymorphic among or within species. Differences among species accounted for the majority of genetic (haplotypic) diversity observed [G(st) = 84(+/-13)%]; nucleotide diversity among species was estimated to be 0.3(+/-0.1)%. Knobcone pine and Monterey pine displayed almost no genetic variation within or among populations. Bishop pine also showed little variability within populations, but did display strong population differences [G(st) = 87(+/-8)%] that were a result of three distinct geographic groups. Mean nucleotide diversity within populations was 0.003(+/-0.002)%; intrapopulation polymorphisms were found in only five populations. This pattern of genetic variation contrasts strongly with findings from study of nuclear genes (allozymes) in the group, where most genetic diversity resides within populations rather than among populations or species. Regions of the genome subject to frequent length mutations were identified; estimates of subdivision based on length variant frequencies in one region differed strikingly from those based on site mutations or allozymes. Two trees were identified with a major chloroplast DNA inversion that closely resembled one documented between Pinus and Pseudotsuga. PMID:7905846

Customized vs population-based growth charts to identify neonates at risk of adverse outcome: systematic review and Bayesian meta-analysis of observational studies.

PubMed

Chiossi, G; Pedroza, C; Costantine, M M; Truong, V T T; Gargano, G; Saade, G R

2017-08-01

To compare the effectiveness of customized vs population-based growth charts for the prediction of adverse pregnancy outcomes. MEDLINE, ClinicalTrials.gov and The Cochrane Library were searched up to 31 May 2016 to identify interventional and observational studies comparing adverse outcomes among large- (LGA) and small- (SGA) for-gestational-age neonates, when classified according to customized vs population-based growth charts. Perinatal mortality and admission to the neonatal intensive care unit (NICU) of both SGA and LGA neonates, intrauterine fetal demise (IUFD) and neonatal mortality of SGA neonates, and neonatal shoulder dystocia and hypoglycemia as well as maternal third- and fourth-degree perineal lacerations in LGA pregnancies were evaluated. The electronic search identified 237 records that were examined based on title and abstract, of which 27 full-text articles were examined for eligibility. After excluding seven articles, 20 observational studies were included in a Bayesian meta-analysis. Neonates classified as SGA according to customized growth charts had higher risks of IUFD (odds ratio (OR), 7.8 (95% CI, 4.2-12.3)), neonatal death (OR, 3.5 (95% CI, 1.1-8.0)), perinatal death (OR, 5.8 (95% CI, 3.8-7.8)) and NICU admission (OR, 3.6 (95% CI, 2.0-5.5)) than did non-SGA cases. Neonates classified as SGA according to population-based growth charts also had increased risk for adverse outcomes, albeit the point estimates of the pooled ORs were smaller: IUFD (OR, 3.3 (95% CI, 1.9-5.0)), neonatal death (OR, 2.9 (95% CI, 1.2-4.5)), perinatal death (OR, 4.0 (95% CI, 2.8-5.1)) and NICU admission (OR, 2.4 (95% CI, 1.7-3.2)). For LGA vs non-LGA, there were no differences in pooled ORs for perinatal death, NICU admission, hypoglycemia and maternal third- and fourth-degree perineal lacerations when classified according to either the customized or the population-based approach. In contrast, both approaches indicated that LGA neonates are at increased risk for shoulder dystocia than are non-LGA ones (OR, 7.4 (95% CI, 4.9-9.8) using customized charts; OR, 8.0 (95% CI, 5.3-10.1) using population-based charts). Both customized and population-based growth charts can identify SGA neonates at risk for adverse outcomes. Although the point estimates of the pooled ORs may differ for some outcomes, the overlapping CIs and lack of direct comparisons prevent conclusions from being drawn on the superiority of one method. Future clinical trials should compare directly the two approaches in the management of fetuses of abnormal size. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Testing the Latino paradox in Latin America: a population-based study of Intra-regional immigrants in Chile.

PubMed

Cabieses, Baltica; Tunstall, Helena; Pickett, Kate

2013-10-01

Several studies in high-income countries report better health status of immigrants compared to the local population ("healthy migrant" effect), regardless of their socioeconomic deprivation. This is known as the Latino paradox. To test the Latino paradox within Latin America by assessing the health of international immigrants to Chile, most of them from Latin American countries, and comparing them to the Chilean-born. Secondary data analysis of the population-based CASEN survey-2006. Three health outcomes were included: disability, illness/accident, and cancer/chronic condition (dichotomous). Demographics (age, sex, marital status, urban/rural, ethnicity), socioeconomic-status (SES: educational level, employment status and household income per-capita), and material standards (overcrowding, sanitation, housing quality). Crude and adjusted weighted regression models were performed. One percent of Chile's population were immigrants, mainly from other Latin American countries. A "healthy migrant" effect appeared within the total immigrant population: this group had a significantly lower crude prevalence of almost all health indicators than the Chilean-born, which remained after adjusting for various demographic characteristics. However, this effect lost significance when adjusting by SES for most outcomes. The Latino paradox was not observed for international immigrants compared to the local population in Chile. Also, health of immigrants with the longest time of residency showed similar health rates to the Chilean-born. The Latino paradox was not observed in Chile. Protecting low SES immigrants in Chile could have large positive effects in their health at arrival and over time.

Are cardiovascular disease risk assessment and management programmes cost effective? A systematic review of the evidence.

PubMed

Lee, John Tayu; Lawson, Kenny D; Wan, Yizhou; Majeed, Azeem; Morris, Stephen; Soljak, Michael; Millett, Christopher

2017-06-01

The World Health Organization recommends that countries implement population-wide cardiovascular disease (CVD) risk assessment and management programmes. The aim of this study was to conduct a systematic review to evaluate whether this recommendation is supported by cost-effectiveness evidence. Published economic evaluations were identified via electronic medical and social science databases (including Medline, Web of Science, and the NHS Economic Evaluation Database) from inception to March 2016. Study quality was evaluated using a modified version of the Consolidated Health Economic Evaluation Reporting Standards. Fourteen economic evaluations were included: five studies based on randomised controlled trials, seven studies based on observational studies and two studies using hypothetical modelling synthesizing secondary data. Trial based studies measured CVD risk factor changes over 1 to 3years, with modelled projections of longer term events. Programmes were either not, or only, cost-effective under non-verified assumptions such as sustained risk factor changes. Most observational and hypothetical studies suggested programmes were likely to be cost-effective; however, study deigns are subject to bias and subsequent empirical evidence has contradicted key assumptions. No studies assessed impacts on inequalities. In conclusion, recommendations for population-wide risk assessment and management programmes lack a robust, real world, evidence basis. Given implementation is resource intensive there is a need for robust economic evaluation, ideally conducted alongside trials, to assess cost effectiveness. Further, the efficiency and equity impact of different delivery models should be investigated, and also the combination of targeted screening with whole population interventions recognising that there multiple approaches to prevention. Copyright © 2017. Published by Elsevier Inc.

A Population-based survey of risk for cancer in individuals diagnosed with myotonic dystrophy

PubMed Central

Abbott, Diana; Johnson, Nicholas E; Cannon-Albright, Lisa A.

2018-01-01

Introduction The risk of cancer in patients diagnosed with myotonic dystrophy (DM) is reported for the homogeneous Utah population. Methods Clinical data accessed from the largest Utah healthcare providers have been record-linked to the Utah Population Database (UPDB), a population-based resource also linked to the Utah Cancer Registry. Relative risks were estimated for 36 cancers of different types in 281 DM patients. Results Testicular cancer (RR=10.74; 95% CI: 1.91, 38.79), endometrial cancer (6.98; 1.24, 25.22), and Non-Hodgkins lymphoma (4.25; 1.16, 12.43) were all observed at significant excess in DM patients. Discussion This study confirms an overall increased risk of cancer in DM. Individuals diagnosed with DM might benefit from risk counseling. PMID:27064430

Differences in cytochrome p450-mediated pharmacokinetics between chinese and caucasian populations predicted by mechanistic physiologically based pharmacokinetic modelling.

PubMed

Barter, Zoe E; Tucker, Geoffrey T; Rowland-Yeo, Karen

2013-12-01

International Conference on Harmonization of Technical Requirements for Registration of Pharmaceuticals for Human Use (ICH) guidelines emphasize the need for better understanding of the influence of ethnicity on drug response to minimize duplication of clinical studies, thereby expediting drug approval. We have developed a Chinese database for the prediction of differences in the population kinetics of drugs mainly metabolized by cytochromes P450 (CYPs) relative to Caucasian populations. Such predictions should help to inform the need for duplication of in vivo pharmacokinetic studies in the two ethnic groups and the design of such studies. Demographic and physiological data for Chinese, along with information on CYP abundances and the frequencies of associated genetic polymorphisms in Chinese, were collated from literature sources and incorporated within the Simcyp Population-based Simulator(®) (v11.1). Default Simcyp parameter values for a virtual Caucasian population and for model compounds metabolized principally by specific CYPs were used as the point of reference. The drugs and the main CYPs involved in their metabolism were phenacetin (CYP1A2), desipramine (CYP2D6), tolbutamide (CYP2C9), omeprazole (CYP2C19), and alprazolam and midazolam (CYP3A). Hydroxy bupropion formation was used as a more sensitive marker of CYP2B6 activity than bupropion kinetics. Observed plasma drug concentration-time profiles and pharmacokinetic parameters after oral and, where possible, intravenous dosing were obtained from published in vivo studies in both Chinese and Caucasian subjects. Virtual subjects generated within Simcyp were matched to the subjects used in the in vivo studies with respect to age, sex, dosage and, where possible, CYP phenotype frequency. Predicted and observed plasma drug concentrations and weight-normalized clearances were compared between the ethnic groups. Significant differences were identified between Chinese and Caucasian populations in the frequency of CYP2C19 poor metabolizers (PMs) [Chinese 13 %; Caucasian 2.4 %], CYP2D6 PMs and intermediate metabolizers (IMs) [Chinese PMs 0.3 %, IMs 39 %; Caucasian PMs 8 %, IMs <1 %], the hepatic abundance of CYP2C19 (mean values: Chinese 8 pmol/mg; Caucasian 14 pmol/mg) and liver weight (mean values: Chinese 1198 g; Caucasian 1603 g). The observed plasma drug concentration-time profiles and weight-normalized clearances were predicted with reasonable accuracy (100 % within twofold; 89 % within 1.5-fold) in both ethnic groups. The predicted phenacetin, tolbutamide, omeprazole, desipramine, midazolam (intravenous), midazolam (oral), alprazolam (intravenous) and alprazolam (oral) clearances were 36, 25, 51, 43, 24, 17, 21 and 22 % lower, respectively, in Chinese than in Caucasians; the observed clearances were 28, 2, 75, 42, 19, 62, 20 and 21 % lower, respectively. Predicted and observed formation of hydroxy bupropion was lower in Caucasians than in Chinese (6 and 20 %, respectively). Differences between ethnic groups were less after normalization for body weight. The results of this study indicate the value of simulation based on mechanistic physiologically based pharmacokinetic modelling (PBPK) in anticipating the likely extent of any differences in the kinetics of CYP substrates in Chinese and Caucasian populations arising from demographic, physiological and genetic differences.

Out of Africa: modern human origins special feature: explaining worldwide patterns of human genetic variation using a coalescent-based serial founder model of migration outward from Africa.

PubMed

DeGiorgio, Michael; Jakobsson, Mattias; Rosenberg, Noah A

2009-09-22

Studies of worldwide human variation have discovered three trends in summary statistics as a function of increasing geographic distance from East Africa: a decrease in heterozygosity, an increase in linkage disequilibrium (LD), and a decrease in the slope of the ancestral allele frequency spectrum. Forward simulations of unlinked loci have shown that the decline in heterozygosity can be described by a serial founder model, in which populations migrate outward from Africa through a process where each of a series of populations is formed from a subset of the previous population in the outward expansion. Here, we extend this approach by developing a retrospective coalescent-based serial founder model that incorporates linked loci. Our model both recovers the observed decline in heterozygosity with increasing distance from Africa and produces the patterns observed in LD and the ancestral allele frequency spectrum. Surprisingly, although migration between neighboring populations and limited admixture between modern and archaic humans can be accommodated in the model while continuing to explain the three trends, a competing model in which a wave of outward modern human migration expands into a series of preexisting archaic populations produces nearly opposite patterns to those observed in the data. We conclude by developing a simpler model to illustrate that the feature that permits the serial founder model but not the archaic persistence model to explain the three trends observed with increasing distance from Africa is its incorporation of a cumulative effect of genetic drift as humans colonized the world.

Familial link of otitis media requiring tympanostomy tubes.

PubMed

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.

Genetic variation and forensic characteristic analysis of 25 STRs of a novel fluorescence co-amplification system in Chinese Southern Shaanxi Han population

PubMed Central

Liu, Yao-Shun; Chen, Jian-Gang; Mei, Ting; Guo, Yu-Xin; Meng, Hao-Tian; Li, Jian-Fei; Wei, Yuan-Yuan; Jin, Xiao-Ye; Zhu, Bo-Feng; Zhang, Li-Ping

2017-01-01

We analyzed the genetic polymorphisms of 15 autosomal and 10 Y-chromosomal STR loci in 214 individuals of Han population from Southern Shaanxi of China and studied the genetic relationships between Southern Shaanxi Han and other populations. We observed a total of 150 alleles at 15 autosomal STR loci with the corresponding allelic frequencies ranging from 0.0023 to 0.5210, and the combined power of discrimination and exclusion for the 15 autosomal STR loci were 0.99999999999999998866 and 0.999998491, respectively. For the 10 Y-STR loci, totally 100 different haplotypes were obtained, of which 94 were unique. The discriminatory capacity and haplotype diversity values of the 10 Y-STR loci were 0.9259 and 0.998269, respectively. The results demonstrated high genetic diversities of the 25 STR loci in the population for forensic applications. We constructed neighbor-joining tree and conducted principal component analysis based on 15 autosomal STR loci and conducted multidimensional scaling analysis and constructed neighbor-joining tree based on 10 Y-STR loci. The results of population genetic analyses based on both autosomal and Y-chromosome STRs indicated that the studied Southern Shaanxi Han population had relatively closer genetic relationship with Eastern Han population, and distant relationships with Croatian, Serbian and Moroccan populations. PMID:28903432

Disease introduction is associated with a phase transition in bighorn sheep demographics.

PubMed

Manlove, Kezia; Cassirer, E Frances; Cross, Paul C; Plowright, Raina K; Hudson, Peter J

2016-10-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. © 2016 by the Ecological Society of America.

Usage of purchased self-tests for HIV and sexually transmitted infections in Amsterdam, the Netherlands: results of population-based and serial cross-sectional studies among the general population and sexual risk groups

PubMed Central

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

Amyotrophic lateral sclerosis, rural environment and agricultural work in the Local Health District of Ferrara, Italy, in the years 1964-1998.

PubMed

Govoni, Vittorio; Granieri, Enrico; Fallica, Elisa; Casetta, Ilaria

2005-11-01

Previous epidemiological surveys, both analytic and descriptive, in the Local Health District (LHD) of Ferrara, northern Italy, have indicated that rural residence and agricultural work might constitute risk factors for Amyotrophic Lateral Sclerosis (ALS). The present investigation is a demographic survey in the LHD of Ferrara in the years 1964-1998 which aimed to verify whether the level of urbanization and agricultural activities might influence the risk of ALS. Based on the data obtained in a recent incidence study in the LHD of Ferrara which reported a mean annual crude incidence rate of ALS in the years 1964-1998 of 1.63 per 100,000 population (95 % CI 1.31-2.00), it was possible to compare the number of observed ALS cases and the number of expected ALS cases according to the level of urbanization and usual occupation on the basis of the residential and occupational pattern identified in the population of the LHD of Ferrara in the study period under the assumption of a homogeneous distribution of ALS. The present survey identified four different levels of urbanization in the LHD of Ferrara in the study period and for none of them was a difference between the number of observed and expected ALS cases found. Also in the most rural of the four identified levels of urbanization (small villages with an average population in the study period lower than 1,000 inhabitants and scattered houses in the countryside) no difference was found between observed and expected number of ALS cases (observed ALS cases 16, 95% Poisson CI 9.1-25.9, expected ALS cases 18.3). Based on the occupational pattern identified in the population of the LHD of Ferrara in the study period the number of incident cases of ALS whose usual occupation was in agricultural work exceeded the expected number (observed ALS cases 22, 95% Poisson CI 13.8-32.3, expected ALS cases 6.0). The present findings indicate that rural residence itself does not influence the risk of ALS while agricultural activities could influence the risk of ALS, with occupational exposure to agricultural chemicals playing a possible role.

A systematic review of population based epidemiological studies in Myasthenia Gravis

PubMed Central

2010-01-01

Background The aim was to collate all myasthenia gravis (MG) epidemiological studies including AChR MG and MuSK MG specific studies. To synthesize data on incidence rate (IR), prevalence rate (PR) and mortality rate (MR) of the condition and investigate the influence of environmental and technical factors on any trends or variation observed. Methods Studies were identified using multiple sources and meta-analysis performed to calculate pooled estimates for IR, PR and MR. Results 55 studies performed between 1950 and 2007 were included, representing 1.7 billion population-years. For All MG estimated pooled IR (eIR): 5.3 per million person-years (C.I.:4.4, 6.1), range: 1.7 to 21.3; estimated pooled PR: 77.7 per million persons (C.I.:64.0, 94.3), range 15 to 179; MR range 0.1 to 0.9 per millions person-years. AChR MG eIR: 7.3 (C.I.:5.5, 7.8), range: 4.3 to 18.0; MuSK MG IR range: 0.1 to 0.32. However marked variation persisted between populations studied with similar methodology and in similar areas. Conclusions We report marked variation in observed frequencies of MG. We show evidence of increasing frequency of MG with year of study and improved study quality. This probably reflects improved case ascertainment. But other factors must also influence disease onset resulting in the observed variation in IR across geographically and genetically similar populations. PMID:20565885

NuSTAR view of the central region of M31

NASA Astrophysics Data System (ADS)

Stiele, H.; Kong, A. K. H.

2018-04-01

Our neighbouring large spiral galaxy, the Andromeda galaxy (M31 or NGC 224), is an ideal target to study the X-ray source population of a nearby galaxy. NuSTAR observed the central region of M31 in 2015 and allows studying the population of X-ray point sources at energies higher than 10 keV. Based on the source catalogue of the large XMM-Newton survey of M31, we identified counterparts to the XMM-Newton sources in the NuSTAR data. The NuSTAR data only contain sources of a brightness comparable (or even brighter) than the selected sources that have been detected in XMM-Newton data. We investigate hardness ratios, spectra, and long-term light curves of individual sources obtained from NuSTAR data. Based on our spectral studies, we suggest four sources as possible X-ray binary candidates. The long-term light curves of seven sources that have been observed more than once show low (but significant) variability.

Population structure and genotypic variation of Crataegus pontica inferred by molecular markers.

PubMed

Rahmani, Mohammad-Shafie; Shabanian, Naghi; Khadivi-Khub, Abdollah; Woeste, Keith E; Badakhshan, Hedieh; Alikhani, Leila

2015-11-01

Information about the natural patterns of genetic variability and their evolutionary bases are of fundamental practical importance for sustainable forest management and conservation. In the present study, the genetic diversity of 164 individuals from fourteen natural populations of Crataegus pontica K.Koch was assessed for the first time using three genome-based molecular techniques; inter-retrotransposon amplified polymorphism (IRAP); inter-simple sequence repeats (ISSR) and start codon targeted (SCoT) polymorphism. IRAP, ISSR and SCoT analyses yielded 126, 254 and 199 scorable amplified bands, respectively, of which 90.48, 93.37 and 83.78% were polymorphic. ISSR revealed efficiency over IRAP and SCoT due to high effective multiplex ratio, marker index and resolving power. The dendrograms based on the markers used and combined data divided individuals into three major clusters. The correlation between the coefficient matrices for the IRAP, ISSR and SCoT data was significant. A higher level of genetic variation was observed within populations than among populations based on the markers used. The lower divergence levels depicted among the studied populations could be seen as evidence of gene flow. The promotion of gene exchange will be very beneficial to conserve and utilize the enormous genetic variability. Copyright © 2015 Elsevier B.V. All rights reserved.

Determination of Instructional Leadership Administrators

ERIC Educational Resources Information Center

Öznacar, Behcet; Osma, Elif

2016-01-01

This research, based on observations of teacher candidates in prep school educations and secondary schools the instructional leaders of executive managers who aim at investigating a research study descriptive nature. General screening model is used for the study. The research population in the Near East University in the Faculty of Education,…

Influence of exposure differences on city-to-city heterogeneity in PM2.5-mortality associations in US cities

EPA Science Inventory

Multi-city population-based epidemiological studies have observed heterogeneity between city-specific fine particulate matter (PM2.5)-mortality effect estimates. These studies typically use ambient monitoring data as a surrogate for exposure leading to potential exposure misclass...

Mobile phone use and glioma risk: comparison of epidemiological study results with incidence trends in the United States.

PubMed

Little, M P; Rajaraman, P; Curtis, R E; Devesa, S S; Inskip, P D; Check, D P; Linet, M S

2012-03-08

In view of mobile phone exposure being classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC), we determined the compatibility of two recent reports of glioma risk (forming the basis of the IARC's classification) with observed incidence trends in the United States. Comparison of observed rates with projected rates of glioma incidence for 1997-2008. We estimated projected rates by combining relative risks reported in the 2010 Interphone study and a 2011 Swedish study by Hardell and colleagues with rates adjusted for age, registry, and sex; data for mobile phone use; and various latency periods. US population based data for glioma incidence in 1992-2008, from 12 registries in the Surveillance, Epidemiology, and End Results (SEER) programme (Atlanta, Detroit, Los Angeles, San Francisco, San Jose-Monterey, Seattle, rural Georgia, Connecticut, Hawaii, Iowa, New Mexico, and Utah). Data for 24,813 non-Hispanic white people diagnosed with glioma at age 18 years or older. Age specific incidence rates of glioma remained generally constant in 1992-2008 (-0.02% change per year, 95% confidence interval -0.28% to 0.25%), a period coinciding with a substantial increase in mobile phone use from close to 0% to almost 100% of the US population. If phone use was associated with glioma risk, we expected glioma incidence rates to be higher than those observed, even with a latency period of 10 years and low relative risks (1.5). Based on relative risks of glioma by tumour latency and cumulative hours of phone use in the Swedish study, predicted rates should have been at least 40% higher than observed rates in 2008. However, predicted glioma rates based on the small proportion of highly exposed people in the Interphone study could be consistent with the observed data. Results remained valid if we used either non-regular users or low users of mobile phones as the baseline category, and if we constrained relative risks to be more than 1. Raised risks of glioma with mobile phone use, as reported by one (Swedish) study forming the basis of the IARC's re-evaluation of mobile phone exposure, are not consistent with observed incidence trends in US population data, although the US data could be consistent with the modest excess risks in the Interphone study.

Long-term effect of statins on the risk of new-onset osteoporosis: A nationwide population-based cohort study.

PubMed

Lin, Tsung-Kun; Chou, Pesus; Lin, Ching-Heng; Hung, Yi-Jen; Jong, Gwo-Ping

2018-01-01

Several observational cohort and meta-analytical studies in humans have shown that statin users have a lower risk of fractures or greater bone mineral densities (BMD) than nonusers. However, some studies including randomized clinical trials have the opposite results, particularly in Asian populations. This study investigates the impacts of statins on new-onset osteoporosis in Taiwan. In a nationwide retrospective population-based cohort study, 45,342 subjects aged between 50-90 years having received statin therapy (statin-users) since January 1 2001, and observed through December 31 2013 were selected from the National Health Insurance Research Database of Taiwan. Likewise, 115,594 patients had no statin therapy (statin-non-users) were included as controls in this study. Multivariable Cox proportional hazards analysis for drug exposures was employed to evaluate the association between statin treatment and new-onset of osteoporosis risk. We also used the long-rank test to evaluate the difference of probability of osteoporosis-free survival. During the 13-year follow-up period, 16,146 of all enrolled subjects (10.03%) developed osteoporosis, including 3097 statin-users (6.83%) and 13,049 statin-non-users (11.29%). Overall, statin therapy reduced the risk of new-onset osteoporosis by 48% (adjusted hazard ratio [HR] 0.52; 95% CI 0.50 to 0.54). A dose-response relationship between statin treatment and the risk of new-onset osteoporosis was observed. The adjusted hazard ratios for new-onset osteoporosis were 0.84 (95% CI, 0.78 to 0.90), 0.56 (95% CI, 0.52 to 0.60) and 0.23 (95% CI, 0.21 to 0.25) when cumulative defined daily doses (cDDDs) ranged from 28 to 90, 91 to 365, and more than 365, respectively, relative to nonusers. Otherwise, high-potency statins (rosuvastatin and atorvastatin) and moderate-potency statin (simvastatin) seemed to have a potential protective effect for osteoporosis. In this population-based cohort study, we found that statin use is associated with a decreased risk of osteoporosis in both genders. The osteoprotective effect of statins seemed to be more prominent with a dependency on the cumulative dosage and statin intensity.

Coffee consumption and risk of colorectal cancer in a population-based prospective cohort of Japanese men and women.

PubMed

Lee, Kyung-Jae; Inoue, Manami; Otani, Tetsuya; Iwasaki, Motoki; Sasazuki, Shizuka; Tsugane, Shoichiro

2007-09-15

We prospectively examined the association between coffee consumption and the risk of developing colorectal cancer in a large population-based cohort study (the JPHC Study) of Japanese men and women. Data were analyzed from a population-based cohort of 96,162 subjects (46,023 men and 50,139 women). A total of 1,163 incident colorectal cancers were identified during the follow-up period, including 763 cases of colon cancer and 400 of rectal cancer. We observed a significant inverse association between coffee consumption and the risk of developing invasive colon cancer among women. Compared with those who almost never consumed coffee, women who regularly consumed 3 or more cups of coffee per day had a RR of 0.44 (95% CI = 0.19-1.04; p for trend = 0.04) after adjustment for potential confounding factors. However, no significant association was found for rectal cancer in women. In men, no significant decrease was observed in any colorectal cancer site. Further, additional analyses on the association of green tea consumption with colorectal cancer risk found no significant association in men or women. These findings suggest that coffee consumption may lower the risk of colon cancer among Japanese women. (c) 2007 Wiley-Liss, Inc.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hepler, K.R.; Hansen, P.A.; Bernard, D.R.

Five emigrating populations of Dolly Varden and cutthroat trout were intercepted in 1989-1991 during seaward migration to Prince William Sound following the Exxon Valdez oil spill; two into the spill area, three into non-spill areas. Study populations were comprised of tagged adults and subadults. Survival rates were estimated with log-linear models of capture histories of tagged fish. We used a two-stage simulation based on bootstrapping and Monte Carlo techniques to compare average survival rates in study populations that were and were not associated with spilled oil. Growth and survival rates were significantly lower in study populations associated with spilled oil.more » Results are consistent with the occurrence of a deleterious impact on growth and survival of emigrating species, although unable to be confirmed as results emanated from observation, not experiment.« less

Solid Tumors After Chemotherapy or Surgery for Testicular Nonseminoma: A Population-Based Study

PubMed Central

Fung, Chunkit; Fossa, Sophie D.; Milano, Michael T.; Oldenburg, Jan; Travis, Lois B.

2013-01-01

Purpose Increased risks of solid tumors after older radiotherapy strategies for testicular cancer (TC) are well established. Few population-based studies, however, focus on solid cancer risk among survivors of TC managed with nonradiotherapy approaches. We quantified the site-specific risk of solid cancers among testicular nonseminoma patients treated in the modern era of cisplatin-based chemotherapy, without radiotherapy. Patients and Methods Standardized incidence ratios (SIRs) for solid tumors were calculated for 12,691 patients with testicular nonseminoma reported to the population-based Surveillance, Epidemiology, and End Results program (1980 to 2008) and treated initially with either chemotherapy (n = 6,013) or surgery (n = 6,678) without radiotherapy. Patients accrued 116,073 person-years of follow-up. Results Two hundred ten second solid cancers were observed. No increased risk followed surgery alone (SIR, 0.93; 95% CI, 0.76 to 1.14; n = 99 solid cancers), whereas significantly increased 40% excesses (SIR, 1.43; 95% CI, 1.18 to 1.73; n = 111 solid cancers) occurred after chemotherapy. Increased risks of solid cancers after chemotherapy were observed in most follow-up periods (median latency, 12.5 years), including more than 20 years after treatment (SIR, 1.54; 95% CI, 0.96 to 2.33); significantly increased three- to seven-fold risks occurred for cancers of the kidney (SIR, 3.37; 95% CI, 1.79 to 5.77), thyroid (SIR, 4.40; 95% CI, 2.19 to 7.88), and soft tissue (SIR, 7.49; 95% CI, 3.59 to 13.78). Conclusion To our knowledge, this is the first large population-based series reporting significantly increased risks of solid cancers among patients with testicular nonseminoma treated in the modern era of cisplatin-based chemotherapy. Subsequent analytic studies should focus on the evaluation of dose-response relationships, types of solid cancers, latency patterns, and interactions with other possible factors, including genetic susceptibility. PMID:24043737

Variability in the Results of Meta-Analysis as a Function of Comparing Effect Sizes Based on Scores from Noncomparable Measures: A Simulation Study

ERIC Educational Resources Information Center

Nugent, William R.

2017-01-01

Meta-analysis is a significant methodological advance that is increasingly important in research synthesis. Fundamental to meta-analysis is the presumption that effect sizes, such as the standardized mean difference (SMD), based on scores from different measures are comparable. It has been argued that population observed score SMDs based on scores…

EVIDENCE FOR A CONSTANT IMF IN EARLY-TYPE GALAXIES BASED ON THEIR X-RAY BINARY POPULATIONS

NASA Astrophysics Data System (ADS)

Zepf, Stephen E.; Maccarone, T. J.; Kundu, A.; Gonzalez, A. H.; Lehmer, B.; Maraston, C.

2014-01-01

A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having steeper IMFs. These steeper IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars and black holes. In this paper, we specifically predict the variation in the number of black holes and neutron stars in early type galaxies based on the IMF variation required to reproduce the observed mass-to-light ratio trends with galaxy mass. We then test whether such variations are observed by studying the field low-mass X-ray binary populations (LMXBs) of nearby early-type galaxies. These binaries are field neutron stars or black holes accreting from a low-mass donor star. We specifically compare the number of field LMXBs per K-band light in a well-studied sample of elliptical galaxies, and use this result to distinguish between an invariant IMF and one that is Kroupa/Chabrier-like at low masses and steeper at high masses. We discuss how these observations constrain the possible forms of the IMF variations and how future Chandra observations can enable sharper tests of the IMF.

Imputation-Based Meta-Analysis of Severe Malaria in Three African Populations

PubMed Central

Band, Gavin; Le, Quang Si; Jostins, Luke; Pirinen, Matti; Kivinen, Katja; Jallow, Muminatou; Sisay-Joof, Fatoumatta; Bojang, Kalifa; Pinder, Margaret; Sirugo, Giorgio; Conway, David J.; Nyirongo, Vysaul; Kachala, David; Molyneux, Malcolm; Taylor, Terrie; Ndila, Carolyne; Peshu, Norbert; Marsh, Kevin; Williams, Thomas N.; Alcock, Daniel; Andrews, Robert; Edkins, Sarah; Gray, Emma; Hubbart, Christina; Jeffreys, Anna; Rowlands, Kate; Schuldt, Kathrin; Clark, Taane G.; Small, Kerrin S.; Teo, Yik Ying; Kwiatkowski, Dominic P.; Rockett, Kirk A.; Barrett, Jeffrey C.; Spencer, Chris C. A.

2013-01-01

Combining data from genome-wide association studies (GWAS) conducted at different locations, using genotype imputation and fixed-effects meta-analysis, has been a powerful approach for dissecting complex disease genetics in populations of European ancestry. Here we investigate the feasibility of applying the same approach in Africa, where genetic diversity, both within and between populations, is far more extensive. We analyse genome-wide data from approximately 5,000 individuals with severe malaria and 7,000 population controls from three different locations in Africa. Our results show that the standard approach is well powered to detect known malaria susceptibility loci when sample sizes are large, and that modern methods for association analysis can control the potential confounding effects of population structure. We show that pattern of association around the haemoglobin S allele differs substantially across populations due to differences in haplotype structure. Motivated by these observations we consider new approaches to association analysis that might prove valuable for multicentre GWAS in Africa: we relax the assumptions of SNP–based fixed effect analysis; we apply Bayesian approaches to allow for heterogeneity in the effect of an allele on risk across studies; and we introduce a region-based test to allow for heterogeneity in the location of causal alleles. PMID:23717212

Home Care and Health Reform: Changes in Home Care Utilization in One Canadian Province, 1990-2000

ERIC Educational Resources Information Center

Penning, Margaret J.; Brackley, Moyra E.; Allan, Diane E.

2006-01-01

Purpose: This study examines population-based trends in home care service utilization, alone and in conjunction with hospitalizations, during a period of health reform in Canada. It focuses on the extent to which observed trends suggest enhanced community-based care relative to three competing hypotheses: cost-cutting, medicalization, and…

Optimizing the creation of base populations for aquaculture breeding programs using phenotypic and genomic data and its consequences on genetic progress.

PubMed

Fernández, Jesús; Toro, Miguel Á; Sonesson, Anna K; Villanueva, Beatriz

2014-01-01

The success of an aquaculture breeding program critically depends on the way in which the base population of breeders is constructed since all the genetic variability for the traits included originally in the breeding goal as well as those to be included in the future is contained in the initial founders. Traditionally, base populations were created from a number of wild strains by sampling equal numbers from each strain. However, for some aquaculture species improved strains are already available and, therefore, mean phenotypic values for economically important traits can be used as a criterion to optimize the sampling when creating base populations. Also, the increasing availability of genome-wide genotype information in aquaculture species could help to refine the estimation of relationships within and between candidate strains and, thus, to optimize the percentage of individuals to be sampled from each strain. This study explores the advantages of using phenotypic and genome-wide information when constructing base populations for aquaculture breeding programs in terms of initial and subsequent trait performance and genetic diversity level. Results show that a compromise solution between diversity and performance can be found when creating base populations. Up to 6% higher levels of phenotypic performance can be achieved at the same level of global diversity in the base population by optimizing the selection of breeders instead of sampling equal numbers from each strain. The higher performance observed in the base population persisted during 10 generations of phenotypic selection applied in the subsequent breeding program.

Key Design Considerations When Calculating Cost Savings for Population Health Management Programs in an Observational Setting.

PubMed

Murphy, Shannon M E; Hough, Douglas E; Sylvia, Martha L; Dunbar, Linda J; Frick, Kevin D

2018-02-08

To illustrate the impact of key quasi-experimental design elements on cost savings measurement for population health management (PHM) programs. Population health management program records and Medicaid claims and enrollment data from December 2011 through March 2016. The study uses a difference-in-difference design to compare changes in cost and utilization outcomes between program participants and propensity score-matched nonparticipants. Comparisons of measured savings are made based on (1) stable versus dynamic population enrollment and (2) all eligible versus enrolled-only participant definitions. Options for the operationalization of time are also discussed. Individual-level Medicaid administrative and claims data and PHM program records are used to match study groups on baseline risk factors and assess changes in costs and utilization. Savings estimates are statistically similar but smaller in magnitude when eliminating variability based on duration of population enrollment and when evaluating program impact on the entire target population. Measurement in calendar time, when possible, simplifies interpretability. Program evaluation design elements, including population stability and participant definitions, can influence the estimated magnitude of program savings for the payer and should be considered carefully. Time specifications can also affect interpretability and usefulness. © Health Research and Educational Trust.

Population genetic analysis of Enterocytozoon bieneusi in humans.

PubMed

Li, Wei; Cama, Vitaliano; Feng, Yaoyu; Gilman, Robert H; Bern, Caryn; Zhang, Xichen; Xiao, Lihua

2012-01-01

Genotyping based on sequence analysis of the ribosomal internal transcribed spacer has revealed significant genetic diversity in Enterocytozoonbieneusi. Thus far, the population genetics of E. bieneusi and its significance in the epidemiology of microsporidiosis have not been examined. In this study, a multilocus sequence typing of E. bieneusi in AIDS patients in Lima, Peru was conducted, using 72 specimens previously genotyped as A, D, IV, EbpC, WL11, Peru7, Peru8, Peru10 and Peru11 at the internal transcribed spacer locus. Altogether, 39 multilocus genotypes were identified among the 72 specimens. The observation of strong intragenic linkage disequilibria and limited genetic recombination among markers were indicative of an overall clonal population structure of E. bieneusi. Measures of pair-wise intergenic linkage disequilibria and a standardised index of association (IAS) based on allelic profile data further supported this conclusion. Both sequence-based and allelic profile-based phylogenetic analyses showed the presence of two genetically isolated groups in the study population, one (group 1) containing isolates of the anthroponotic internal transcribed spacer genotype A, and the other (group 2) containing isolates of multiple internal transcribed spacer genotypes (mainly genotypes D and IV) with zoonotic potential. The measurement of linkage disequilibria and recombination indicated group 2 had a clonal population structure, whereas group 1 had an epidemic population structure. The formation of the two sub-populations was confirmed by STRUCTURE and Wright's fixation index (FST) analyses. The data highlight the power of MLST in understanding the epidemiology of E. bieneusi. Published by Elsevier Ltd.

Revisiting typhoid fever surveillance in low and middle income countries: lessons from systematic literature review of population-based longitudinal studies.

PubMed

Mogasale, Vittal; Mogasale, Vijayalaxmi V; Ramani, Enusa; Lee, Jung Seok; Park, Ju Yeon; Lee, Kang Sung; Wierzba, Thomas F

2016-01-29

The control of typhoid fever being an important public health concern in low and middle income countries, improving typhoid surveillance will help in planning and implementing typhoid control activities such as deployment of new generation Vi conjugate typhoid vaccines. We conducted a systematic literature review of longitudinal population-based blood culture-confirmed typhoid fever studies from low and middle income countries published from 1(st) January 1990 to 31(st) December 2013. We quantitatively summarized typhoid fever incidence rates and qualitatively reviewed study methodology that could have influenced rate estimates. We used meta-analysis approach based on random effects model in summarizing the hospitalization rates. Twenty-two papers presented longitudinal population-based and blood culture-confirmed typhoid fever incidence estimates from 20 distinct sites in low and middle income countries. The reported incidence and hospitalizations rates were heterogeneous as well as the study methodology across the sites. We elucidated how the incidence rates were underestimated in published studies. We summarized six categories of under-estimation biases observed in these studies and presented potential solutions. Published longitudinal typhoid fever studies in low and middle income countries are geographically clustered and the methodology employed has a potential for underestimation. Future studies should account for these limitations.

Serum levels of brominated flame retardants (BFRs: PBDE, HBCD) and influence of dietary factors in a population-based study on Swedish adults.

PubMed

Bjermo, Helena; Aune, Marie; Cantillana, Tatiana; Glynn, Anders; Lind, P Monica; Ridefelt, Peter; Darnerud, Per Ola

2017-01-01

The aim of this study was to investigate associations between serum concentrations of brominated flame retardants and personal characteristics, including diet, in adults participating in a population-based study in Sweden 2010-11. Moreover, observed concentrations were used in a health risk assessment, using published health-based reference values. Serum samples of 170 adult individuals of both sexes were analyzed for 10 PBDE congeners and HBCD by GC-MS. When including concentrations between LOD and LOQ, highest median serum concentration was observed for BDE-153 (1.2 ng/g serum lipid), followed by BDE-209 (0.95 ng/g lipid), BDE-47 (0.49 ng/g lipid) and BDE-100 (0.21 ng/g lipid). Median concentration of HBCD was 0.10 ng/g lipid. A few markedly elevated concentrations of BDE-209, HBCD (77-78 ng/g lipid) and BDE-47 (44 ng/g lipid) were observed. The only statistical significant findings were higher BDE-153 concentrations in men than in women, and positive associations between serum BDE-153 concentrations and consumption of fish (total), beef, mutton and poultry. PBDE concentrations were in accordance with concentrations reported in other European countries but generally lower than those found in North America. Median PBDE serum concentrations observed in adults from Sweden suggest sufficient health protection, when compared with published health-based reference values, although some outliers with high serum concentrations had lower safety margins. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Prior medical conditions and medication use and risk of non-Hodgkin lymphoma in Connecticut United States women.

PubMed

Zhang, Yawei; Holford, Theodore R; Leaderer, Brian; Zahm, Shelia Hoar; Boyle, Peter; Morton, Lindsay McOmber; Zhang, Bing; Zou, Kaiyong; Flynn, Stuart; Tallini, Giovanni; Owens, Patricia H; Zheng, Tongzhang

2004-05-01

To further investigate the role of prior medical conditions and medication use in the etiology of non-Hodgkin lymphoma (NHL), we analyzed the data from a population-based case-control study of NHL in Connecticut women. A total of 601 histologically confirmed incident cases of NHL and 717 population-based controls were included in this study. In-person interviews were administered using standardized, structured questionnaires to collect information on medical conditions and medication use. An increased risk was found among women who had a history of autoimmune disorders (such as rheumatoid arthritis, lupus erythematosus, Sjogren's syndrome, and multiple sclerosis), anemia, eczema, or psoriasis. An increased risk was also observed among women who had used steroidal anti-inflammatory drugs and tranquilizers. A reduced risk was found for women who had scarlet fever or who had used estrogen replacement therapy, aspirin, medications for non-insulin dependent diabetes, HMG-CoA reductase inhibitors, or beta-adrenergic blocking agents. Risk associated with past medical history appeared to vary based on NHL subtypes, but the results were based on small number of exposed subjects. A relationship between certain prior medical conditions and medication use and risk of NHL was observed in this study. Further studies are warranted to confirm our findings.

Increased risk of pyogenic liver abscess in patients with alcohol intoxication: A population-based retrospective cohort study.

PubMed

Wang, Yao-Chien; Yang, Kai-Wei; Lee, Tien-Ying Peter; Lin, Cheng-Li; Liaw, Geng-Wang; Hung, Dong-Zong; Kao, Chia-Hung; Chen, Wei-Kung; Yang, Tse-Yen

2017-11-01

We designed a population-based retrospective cohort study to investigate the association between the event of alcohol intoxication and the risk of pyogenic liver abscess. The present study enrolled 245,076 patients with a history of alcohol intoxication from 2000 to 2010 and matched each of them with four comparison patients, with similar mean age and sex ratios. We determined the cumulative incidences and adjusted hazard ratios (aHRs) of liver abscess. A significant association was observed between alcohol intoxication and liver abscess. The incidence density rate of liver abscess was 3.47-fold greater in the alcohol intoxication (AI) cohort than in the non-AI cohort (12.2 vs. 3.43 per 10,000 person-years), with an adjusted HR (aHR) of 2.64 (95% CI = 2.26 to 3.08). This population-based study positively associated the event of alcohol intoxication with increased risk of liver abscess. Our findings warrant further large-scale and in-depth investigations in this area. Copyright © 2017 Elsevier Inc. All rights reserved.

16S partial gene mitochondrial DNA and internal transcribed spacers ribosomal DNA as differential markers of Trichuris discolor populations.

PubMed

Callejón, R; Halajian, A; de Rojas, M; Marrugal, A; Guevara, D; Cutillas, C

2012-05-25

Comparative morphological, biometrical and molecular studies of Trichuris discolor isolated from Bos taurus from Spain and Iran was carried out. Furthermore, Trichuris ovis isolated from B. taurus and Capra hircus from Spain has been, molecularly, analyzed. Morphological studies revealed clear differences between T. ovis and T. discolor isolated from B. taurus but differences were not observed between populations of T. discolor isolated from different geographical regions. Nevertheless, the molecular studies based on the amplification and sequencing of the internal transcribed spacers 1 and 2 ribosomal DNA and 16S partial gene mitochondrial DNA showed clear differences between both populations of T. discolor from Spain and Iran suggesting two cryptic species. Phylogenetic studies corroborated these data. Thus, phylogenetic trees based on ITS1, ITS2 and 16S partial gene sequences showed that individuals of T. discolor from B. taurus from Iran clustered together and separated, with high bootstrap values, of T. discolor isolated from B. taurus from Spain, while populations of T. ovis from B. taurus and C. hircus from Spain clustered together but separated with high bootstrap values of both populations of T. discolor. Furthermore, a comparative phylogenetic study has been carried out with the ITS1and ITS2 sequences of Trichuris species from different hosts. Three clades were observed: the first clustered all the species of Trichuris parasitizing herbivores (T. discolor, T. ovis, Trichuris leporis and Trichuris skrjabini), the second clustered all the species of Trichuris parasitizing omnivores (Trichuris trichiura and Trichuris suis) and finally, the third clustered species of Trichuris parasitizing carnivores (Trichuris muris, Trichuris arvicolae and Trichuris vulpis). Copyright © 2011 Elsevier B.V. All rights reserved.

High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian women and cancer study: a population-based prospective study.

PubMed

Gavrilyuk, Oxana; Braaten, Tonje; Skeie, Guri; Weiderpass, Elisabete; Dumeaux, Vanessa; Lund, Eiliv

2014-03-25

Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country. A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods. During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m2, and in current smokers. These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method.

Serum levels of PCDDs, PCDFs and PCBs in non-occupationally exposed population groups living near two incineration plants in Tuscany, Italy.

PubMed

De Felip, Elena; Abballe, Annalisa; Casalino, Francesco; di Domenico, Alessandro; Domenici, Pierangela; Iacovella, Nicola; Ingelido, Anna Maria; Pretolani, Elisabetta; Spagnesi, Maurizio

2008-05-01

A pilot study was carried out in Tuscany, Italy, to provide preliminary information on the concentrations of polychlorinated dibenzodioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorobiphenyls (DL-PCBs), and selected non-dioxin-like PCBs (NDL-PCBs) in groups of subjects living in the vicinity of two incineration plants. Seventy-four volunteers were enrolled from areas identified as under a potential impact from incinerator emissions and from not exposed areas. No significant differences were observed between subjects living in the two types of areas. Total concentrations of PCDDs, PCDFs, and DL-PCBs resulted to be in the range 23-30 pg WHO-TEQ g(-1), lipid base, for subjects in the 27-54 year age groups, while concentrations increased to 40-44 pgTEQ g(-1) for the two 55-67 year age groups. The levels of PCDDs and PCDFs were in good agreement with those observed for unexposed population groups in Italy, while the contribution to total TEQ from DL-PCBs was appreciably higher than those currently observed in the general population in Italy and other countries. As to NDL-PCBs, serum levels of the six "indicator" congeners were in the range 240-300 ng g(-1), lipid base, for subjects in the 27-54 year age groups. A raise in NDL-PCB body burden (430-470 ng g(-1), lipid base) was observed for the two 55+ year age groups, in agreement with the expected age-dependent increase. The findings from this study do not show an incremental exposure to PCDDs and PCDFs in the samples from subjects living around the two incineration plants, whereas PCB congener profiles in all samples suggest a possible impact on the area of interest of industrial activities from near industrial settlements.

Population genomics provide insights into the evolution and adaptation of the eastern honey bee (Apis cerana).

PubMed

Chen, Chao; Wang, Huihua; Liu, Zhiguang; Chen, Xiao; Tang, Jiao; Meng, Fanming; Shi, Wei

2018-06-20

The mechanisms by which organisms adapt to variable environments are a fundamental question in evolutionary biology and are important to protect important species in response to a changing climate. An interesting candidate to study this question is the honey bee Apis cerana, a keystone pollinator with a wide distribution throughout a large variety of climates, that exhibits rapid dispersal. Here, we re-sequenced the genome of 180 A. cerana individuals from eighteen populations throughout China. Using a population genomics approach, we observed considerable genetic variation in A. cerana. Patterns of genetic differentiation indicate high divergence at the subspecies level, and physical barriers rather than distance are the driving force for population divergence. Estimations of divergence time suggested that the main branches diverged between 300 and 500 ka. Analyses of the population history revealed a substantial influence of the Earth's climate on the effective population size of A. cerana, as increased population sizes were observed during warmer periods. Further analyses identified candidate genes under natural selection that are potentially related to honey bee cognition, temperature adaptation, and olfactory. Based on our results, A. cerana may have great potential in response to climate change. Our study provides fundamental knowledge of the evolution and adaptation of A. cerana.

Epidemiology and outcomes of out-of-hospital cardiac arrest in Qatar: A nationwide observational study.

PubMed

Irfan, Furqan B; Bhutta, Zain Ali; Castren, Maaret; Straney, Lahn; Djarv, Therese; Tariq, Tooba; Thomas, Stephen Hodges; Alinier, Guillaume; Al Shaikh, Loua; Owen, Robert Campbell; Al Suwaidi, Jassim; Shuaib, Ashfaq; Singh, Rajvir; Cameron, Peter Alistair

2016-11-15

Out-of-hospital cardiac arrest (OHCA) studies from the Middle East and Asian region are limited. This study describes the epidemiology, emergency health services, and outcomes of OHCA in Qatar. This was a prospective nationwide population-based observational study on OHCA patients in Qatar according to Utstein style guidelines, from June 2012 to May 2013. Data was collected from various sources; the national emergency medical service, 4 emergency departments, and 8 public hospitals. The annual crude incidence of presumed cardiac OHCA attended by EMS was 23.5 per 100,000. The age-sex standardized incidence was 87.8 per 100,000 population. Of the 447 OHCA patients included in the final analysis, most were male (n=360, 80.5%) with median age of 51years (IQR=39-66). Frequently observed nationalities were Qatari (n=89, 19.9%), Indian (n=74, 16.6%) and Nepalese (n=52, 11.6%). Bystander cardiopulmonary resuscitation (CPR) was carried out in 92 (20.6%) OHCA patients. Survival rate was 8.1% (n=36) and multivariable logistic regression indicated that initial shockable rhythm (OR 13.4, 95% CI 5.4-33.3, p=0.001) was associated with higher odds of survival while male gender (OR 0.27, 95% CI 0.1-0.8, p=0.01) and advanced cardiac life support (ACLS) (OR 0.15, 95% CI 0.04-0.5, p=0.02) were associated with lower odds of survival. Standardized incidence and survival rates were comparable to Western countries. Although expatriates comprise more than 80% of the population, Qataris contributed 20% of the total cardiac arrests observed. There are significant opportunities to improve outcomes, including community-based CPR and defibrillation training. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Dramatic Increase in Incidence of Ulcerative Colitis and Crohn's Disease (1988-2011): A Population-Based Study of French Adolescents.

PubMed

Ghione, Silvia; Sarter, Hélène; Fumery, Mathurin; Armengol-Debeir, Laura; Savoye, Guillaume; Ley, Delphine; Spyckerelle, Claire; Pariente, Benjamin; Peyrin-Biroulet, Laurent; Turck, Dominique; Gower-Rousseau, Corinne

2018-02-01

Few data are available to describe the changes in incidence of pediatric-onset inflammatory bowel disease (IBD). The aim of this study was to describe changes in incidence and phenotypic presentation of pediatric-onset IBD in northern France during a 24-year period. Pediatric-onset IBD (<17 years) was issued from a population-based IBD study in France between 1988 and 2011. Age groups and digestive location were defined according to the Paris classification. 1,350 incident cases were recorded (8.3% of all IBD) including 990 Crohn's disease (CD), 326 ulcerative colitis (UC) and 34 IBD unclassified (IBDU). Median age at diagnosis was similar in CD (14.4 years (Q1=11.8-Q3=16.0)) and UC (14.0 years (11.0-16.0)) and did not change over time. There were significantly more males with CD (females/males=0.82) than UC (females/males=1.25) (P=0.0042). Median time between onset of symptoms and IBD diagnosis was consistently 3 months (1-6). Mean incidence was 4.4/10 5 for IBD overall (3.2 for CD, 1.1 for UC and 0.1 for IBDU). From 1988-1990 to 2009-2011, a dramatic increase in incidences of both CD and UC were observed in adolescents (10-16 years): for CD from 4.2 to 9.5/10 5 (+126%; P<0.001) and for UC, from 1.6 to 4.1/10 5 (+156%; P<0.001). No modification in age or location at diagnosis was observed in either CD or UC. In this population-based study, CD and UC incidences increased dramatically in adolescents across a 24-year span, suggesting that one or more strong environmental factors may predispose this population to IBD.

Populations, productivity, and feeding habits of seabirds at Cape Thompson, Alaska: Final report

USGS Publications Warehouse

Fadely, Brian S.; Piatt, John F.; Hatch, Scott A.; Roseneau, David G.

1989-01-01

Investigations of seabird population sizes and breeding biology were conducted at Cape Thompson from 1959 to 1961 during pre-development studies associated with the Atomic through 1982, the Alaskan Program (OCSEAP) supported determine whether changes Energy Commission’s “Project Chariot.” From 1976 Outer Continental Shelf Environmental Assessment efforts to recensus seabirds at Cape Thompson and had occurred since the 1959-61 period. Prior to the present study, it had been 6 years since the last efforts to census seabird colonies in this area.We established a field camp at the and occupied it continuously until 31 were selected for cliff nesting species comprising the Cape Thompson complex, mouth of Ikijaktusak Creek on 2 July August 1988. Permanent study plots in four of the five discrete colonies and regular observations were made throughout the study to document attendance patterns, breeding phenology, and success of murres and kittiwakes. Periodic collections of adults offshore were used to determine the food habits of study species. Shore-based work was supplemented with offshore studies of seabird foraging from the USFWS vessel Eagle-Tiglax, 24-31 August (Fig. 2).Correlation analysis revealed negative trends in murre attendance at all Cape Thompson colonies between 1960 and 1982 or 1988, significantly so for 3 of the 5 colonies. Based on apparent changes in species composition within the colonies, Common Murres declined at a more rapid rate than Thick-billed Murres between 1960 and 1988. Combining information from all colonies, it appears that murre populations have been relatively stable since about 1979. In contrast to murres, the kittiwake population showed no significant trends between 1960 and 1982 or between 1960 and 1988. All fluctuations in kittiwake numbers documented between years were within the variability expected within years. Breeding productivity of murres was about average during 1988 (0.47 young/pair), whereas the productivity of kittiwakes was very poor (0.15 young/pair).Murres and kittiwakes fed mostly on arctic cod and sand lance distributed widely but in low concentrations (e.g., 0.1-10 g/m3) UP to 1.20 km north and northwest of Cape Thompson. In the total area surveyed (225 km2), only two major feeding aggregations were observed where fish school densities exceeded 15 g/ins. Forage fish densities were higher in shallow Alaska Coastal Current waters than offshore in Bering Sea waters, and piscivorous seabirds like murres and kittiwakes fed mostly in coastal waters. Reduced numbers of fish in murre and kittiwake stomachs in August and low breeding success of kittiwakes suggested that forage fish densities observed around Cape Thompson in late August were sufficient to sustain murres but were insufficient for, or inaccessible to, kittiwakes.The breeding failure of Black-legged Kittiwakes at Cape Thompson in 1988 was part throughout causes of kittiwakes of a pervasive syndrome of failure in this species observed the Bering/Chukchi seas and Gulf of Alaska in recent years. The recurrent widespread breeding failure need to be identified if are to have a role in area-wide population monitoring during the period of Alaskan OCS development by the oil and gas industry.The system of land-based plots established in 1988 is recommended for future population monitoring of cliff-nesting birds at Cape Thompson. Based on the coefficients of variation among counts observed in this study, it is estimated that 10 replicate counts per year would detect an 8% change in numbers of Thick-billed Murres between years and a 12% change in Common Murres, with 75% certainty of statistical significance at the 0.05 level. Similarly, a 9% annual change in the population of Black-legged Kittiwakes should be detectable at the 0.05 significance level given samples of 10 replicate counts of the land-based plots.

The Prevalence of Amblyopia and Its Determinants in a Population-based Study.

PubMed

Faghihi, Mohammad; Hashemi, Hassan; Nabovati, Payam; Saatchi, Mohammad; Yekta, Abbasali; Rafati, Shokoofeh; Ostadimoghaddam, Hadi; Khabazkhoob, Mehdi

2017-12-01

To determine the prevalence of amblyopia and its determinants in a population-based study in Mashhad County, Iran. This cross-sectional, population-based study was conducted on the population of Mashhad County aged >1 year using randomized stratified cluster sampling. Examinations were performed after selection of the participants and their free transportation to the sampling site. The examinations included the measurement of uncorrected and corrected visual acuity, cycloplegic and non-cycloplegic refraction, cover testing, slit-lamp biomicroscopy, and ophthalmoscopy. In this study, amblyopia was defined as best corrected visual acuity (BCVA) of 20/30 or less or 2-line interocular optotype acuity differences with no pathology. After considering the exclusion criteria, the data of 2739 individuals, 65.6% of whom were women, were analyzed. The mean age of the participants was 29.5±17.5 years. The prevalence of amblyopia was 4.6% (95% CI: 3.77%-5.43%) in the total population. The lowest prevalence was 2.24% in the age group 5-15 years (95% CI: 0.99%-3.48%) and the highest prevalence was 7.14% in the age group 55-65 years (95% CI: 2.64%-11.56%). Anisometropic amblyopia was observed in 45.24% of the amblyopic participants. Isometropic, mixed (strabismic/anisometropic), and strabismic amblyopia were other common causes of amblyopia, with a prevalence of 24.6%, 16.67%, and 13.49% in amblyopic patients, respectively. The odds ratio (OR) of having amblyopia for each 1-year increase in age was 1.02 (95% CI: 1.01-1.03). Amblyopia was less common in people with better socioeconomic status. This study showed the prevalence of amblyopia in all age groups in a population-based study for the first time. The findings of this study regarding the relatively high prevalence of amblyopia in the older population and its lower prevalence in young people indicate attention to amblyopia in recent years.

Educational differences in incidence of cancer in Lithuania, 2001-2009: evidence from census-linked cancer registry data.

PubMed

Smailyte, Giedre; Jasilionis, Domantas; Vincerzevskiene, Ieva; Krilaviciute, Agne; Ambrozaitiene, Dalia; Stankuniene, Vladislava; Shkolnikov, Vladimir M

2015-05-01

This study used population-based census-linked cancer incidence data to identify patterns of educational differentials in the risk of cancer by detailed sites of cancer in Lithuania. The study is based on the linkage between all records of the 2001 population census, all records from the Lithuanian Cancer Registry (cancer incidence), and all death and emigration records from Statistics Lithuania for the period between 6 April 2001 and 31 December 2009. The study population (cohort) includes all permanent residents of Lithuania aged 30-74 years on the day of the census (6 April 2001). The study found that cancers of the lip, mouth, and pharynx, esophagus, stomach, larynx, urinary bladder, pancreas, and lung for men and cancers of the cervix uteri, lung, and colon for women show a statistically significant inverse educational gradient with excess incidence in the lowest educational group. At the same time, a reversed cancer risk gradient with the highest incidence for the higher education group was observed for thyroid cancer, melanoma, nonmelanoma skin cancers, and non-Hodgkin lymphomas. This group also includes prostate cancer, kidney cancer, and multiple myeloma for men and cancer of the pancreas, breast cancer, cancer of the colon, and cancer of the uterus for women. The associations between education and cancer incidence observed in this study reflect the concordance between social status and lifestyle-related risk factors for cancer. Cancer awareness in society has also contributed toward the observed higher risk of cancer, which is usually promoted more by patients with higher education.

SSR and morphological trait based population structure analysis of 130 diverse flax (Linum usitatissimum L.) accessions.

PubMed

Choudhary, Shashi Bhushan; Sharma, Hariom Kumar; Kumar, Arroju Anil; Maruthi, Rangappa Thimmaiah; Mitra, Jiban; Chowdhury, Isholeena; Singh, Binay Kumar; Karmakar, Pran Gobinda

2017-02-01

A total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST-SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI=0.46; He=0.31; P=85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P=0.01. The maximum Nei's unbiased genetic distance (D=0.11) was observed between fibre type and linseed type exotic sub-populations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasm. Copyright © 2016 Académie des sciences. Published by Elsevier Masson SAS. All rights reserved.

Differences in dehydration tolerance among populations of a gametophyte-only fern.

PubMed

Chambers, Sally M; Watkins, J E; Sessa, Emily B

2017-04-01

For many plant species, historical climatic conditions may have left lasting imprints that are detectable in contemporary populations. Additionally, if these historical conditions also prevented gene flow among populations, these populations may be differentiated with respect to one another and their contemporary environmental conditions. For the fern, Vittaria appalachiana , one theory is that historical conditions during the Pleistocene largely shaped both the distribution and lack of sporophyte production. Our goals-based on this theory-were to examine physiological differences among and within populations spanning the species' geographic range, and the contribution of historical climatic conditions to this differentiation. We exposed explants from five populations to four drying treatments and examined differences in physiological response. Additionally, we examined the role of historical and current climatic conditions in driving the observed population differentiation. Populations differ in their ability to tolerate varying levels of dehydration, displaying a pattern of countergradient selection. Exposure to historical and contemporary climatic conditions, specifically variation in temperature and precipitation regimes, resulted in population divergence observed among contemporary populations. Historical conditions have shaped not only the distribution of V. appalachiana , but also its current physiological limitations. Results from this study support the hypothesis that climatic conditions during the Pleistocene are responsible for the distribution of this species, and may be responsible for the observed differences in dehydration tolerance. Additionally, dehydration tolerance may be the driving factor for previously reported patterns of countergradient selection in this species. © 2017 Botanical Society of America.

Recruitment and enrollment of African Americans into health promoting programs: the effects of health promoting programs on cardiovascular disease risk study.

PubMed

Okhomina, Victoria I; Seals, Samantha R; Marshall, Gailen D

2018-04-03

Randomized controlled trials (RCT) often employ multiple recruitment methods to attract participants, however, special care must be taken to be inclusive of under-represented populations. We examine how recruiting from an existing observational study affected the recruitment of African Americans into a RCT that included yoga-based interventions. In particular, we report the recruitment success of The Effects of Health Promoting Programs (HPP) on Cardiovascular Disease Risk (NCT02019953), the first yoga-based clinical trial to focus only on African Americans. To recruit participants, a multifaceted recruitment strategy was implemented exclusively in the Jackson Heart Study (JHS) cohort. The HPP recruited from the JHS cohort using direct mailings, signs and flyers placed around JHS study facilities, and through JHS annual follow-up interviews. Enrollment into HPP was open to all active JHS participants that were eligible to return for the third clinic exam (n = 4644). The target sample size was 375 JHS participants over a 24 month recruitment and enrollment period. From the active members of the JHS cohort, 503 were pre-screened for eligibility in HPP. More than 90% of those pre-screened were provisionally eligible for the study. The enrollment goal of 375 was completed after a 16-month enrollment period with over 25% (n = 97) of the required sample size enrolling during the second month of recruitment. The findings show that participants in observational studies can be successfully recruited into RCT. Observational studies provide researchers with a well-defined population that may be of interest when designing clinical trials. This is particularly useful in the recruitment of a high-risk, traditionally underrepresented populations for non-pharmacological clinical trials where traditional recruitment methods may prolong enrollment periods and extend study budgets.

The impact of cardiovascular disease prevalence on women's enrollment in landmark randomized cardiovascular trials: a systematic review.

PubMed

Tsang, Wendy; Alter, David A; Wijeysundera, Harindra C; Zhang, Tony; Ko, Dennis T

2012-01-01

Many studies have demonstrated that women are substantially underrepresented in cardiovascular trials, but few have considered that women develop cardiovascular disease at older ages than men. The extent to which observed gender enrollment inequalities persist after accounting for age-gender differences in disease prevalence is unknown. The purpose of the study was to compare observed rates of women participating in cardiovascular clinical trials with expected rates of female participation based on age- and gender-specific population disease prevalence. Publications between 1997 and 2009 in the three leading medical journals were included to calculate observed women's enrollment rates. Population-based data in Canada were used to determine the expected enrollment rates of women. Multicenter, randomized cardiovascular clinical trials that enrolled both men and women were analyzed. Two reviewers independently extracted data on women's enrollment and important clinical trial characteristics. The female enrollment rate was 30% in the included 325 trials, which ranged from 27% in trials of coronary artery disease, 27% in heart failure, 31% in arrhythmia, to 45% in primary prevention. Increased female enrollment correlated strongly with increasing age at recruitment in cardiovascular clinical trials (P < 0.001). After accounting for age- and gender-specific differences in disease prevalence, gaps in female enrollment were much lower than the expected enrollment rates estimated by 5% in coronary artery disease, 13% in heart failure, 9% in arrhythmia, and 3% in primary prevention. Only cardiovascular trials were evaluated in our study. Female underrepresentation in cardiovascular clinical trials is smaller than conventionally believed after accounting for age- and gender-specific population disease prevalence. Our findings suggest that greater representation of women in cardiovascular clinical trials can be achieved through the recruitment of older populations.

Multiple, Distinct Intercontinental Lineages but Isolation of Australian Populations in a Cosmopolitan Lichen-Forming Fungal Taxon, Psora decipiens (Psoraceae, Ascomycota)

PubMed Central

Leavitt, Steven D.; Westberg, Martin; Nelsen, Matthew P.; Elix, John A.; Timdal, Einar; Sohrabi, Mohammad; St. Clair, Larry L.; Williams, Laura; Wedin, Mats; Lumbsch, H. T.

2018-01-01

Multiple drivers shape the spatial distribution of species, including dispersal capacity, niche incumbency, climate variability, orographic barriers, and plate tectonics. However, biogeographic patterns of fungi commonly do not fit conventional expectations based on studies of animals and plants. Fungi, in general, are known to occur across exceedingly broad, intercontinental distributions, including some important components of biological soil crust communities (BSCs). However, molecular data often reveal unexpected biogeographic patterns in lichenized fungal species that are assumed to have cosmopolitan distributions. The lichen-forming fungal species Psora decipiens is found on all continents, except Antarctica and occurs in BSCs across diverse habitats, ranging from hot, arid deserts to alpine habitats. In order to better understand factors that shape population structure in cosmopolitan lichen-forming fungal species, we investigated biogeographic patterns in the cosmopolitan taxon P. decipiens, along with the closely related taxa P. crenata and P. saviczii. We generated a multi-locus sequence dataset based on a worldwide sampling of these taxa in order to reconstruct evolutionary relationships and explore phylogeographic patterns. Both P. crenata and P. decipiens were not recovered as monophyletic; and P. saviczii specimens were recovered as a monophyletic clade closely related to a number of lineages comprised of specimens representing P. decipiens. Striking phylogeographic patterns were observed for P. crenata, with populations from distinct geographic regions belonging to well-separated, monophyletic lineages. South African populations of P. crenata were further divided into well-supported sub-clades. While well-supported phylogenetic substructure was also observed for the nominal taxon P. decipiens, nearly all lineages were comprised of specimens collected from intercontinental populations. However, all Australian specimens representing P. decipiens were recovered within a single well-supported monophyletic clade consisting solely of Australian samples. Our study supports up to 10 candidate species-level lineages in P. decipiens, based on genealogical concordance and coalescent-based species delimitation analyses. Our results support the general pattern of the biogeographic isolation of lichen-forming fungal populations in Australia, even in cases where closely related congeners have documented intercontinental distributions. Our study has important implications for understanding factors influencing diversification and distributions of lichens associated with BSC. PMID:29527197

Meat and Seafood Consumption in Relation to Plasma Metabolic Profiles in a Chinese Population: A Combined Untargeted and Targeted Metabolomics Study.

PubMed

Lu, Yonghai; Zou, Li; Su, Jin; Tai, E Shyong; Whitton, Clare; Dam, Rob M van; Ong, Choon Nam

2017-06-30

We examined the relationship between different patterns of meat and seafood consumption and plasma metabolic profiles in an Asian population. We selected 270 ethnic Chinese men and women from the Singapore Prospective Study Program based on their dietary habits assessed with a validated food frequency questionnaire. Participants were divided into four subgroups: high meat and high seafood ( n = 60), high meat and low seafood ( n = 64), low meat and high seafood ( n = 60), and low meat and low seafood ( n = 86) consumers. Plasma metabolites were measured using both targeted and untargeted mass spectroscopy-based analyses. A total of 42 metabolites differed significantly by dietary group. Higher concentrations of essential amino acids, polyunsaturated fatty acids, and d-glucose were found in high meat and/or seafood consumers as compared with the group with a low consumption of these animal foods. Red meat, poultry, fish, shellfish, soy products, and dairy were each correlated with at least one differential metabolite ( r = -0.308 to 0.448). Some observations, such as the correlation between fish and 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), confirmed previous studies. Other observations, such as the correlation between shellfish and phosphatidylethanolamine (p36:4), were novel. We also observed significant correlations between plasma metabolites and clinical characteristics, such as CMPF with fasting blood glucose ( r = 0.401). These findings demonstrate a significant influence of meat and seafood consumption on metabolic profiles in the Asian population.

Virtual colleagues, virtually colleagues—physicians’ use of Twitter: a population-based observational study

PubMed Central

Brynolf, Anne; Johansson, Stefan; Appelgren, Ester; Lynoe, Niels; Edstedt Bonamy, Anna-Karin

2013-01-01

Objective To investigate potential violations of patient confidentiality or other breaches of medical ethics committed by physicians and medical students active on the social networking site Twitter. Design Population-based cross-sectional observational study. Setting The social networking site Twitter (Swedish-speaking users, n=298819). Population Physicians and medical students (Swedish-speaking users, n=237) active on the social networking site Twitter between July 2007 and March 2012. Main outcome measure Postings that reflect unprofessional behaviour and ethical breaches among physicians and medical students. Results In all, 237 Twitter accounts were established as held by physicians and medical students and a total of 13 780 tweets were analysed by content. In all, 276 (1.9%) tweets were labelled as ‘unprofessional’. Among these, 26 (0.2%) tweets written by 15 (6.3%) physicians and medical students included information that could violate patient privacy. No information on the personal ID number or names was disclosed, but parts of the patient documentation or otherwise specific indicatory information on patients were found. Unprofessional tweets were more common among users writing under a pseudonym and among medical students. Conclusions In this study of physicians and medical students on Twitter, we observed potential violations of patient privacy and other breaches of medical ethics. Our findings underline that every physician and medical student has to consider his or her presence on social networking sites. It remains to be investigated if the introduction of social networking site guidelines for medical professionals will improve awareness. PMID:23883885

Meat and Seafood Consumption in Relation to Plasma Metabolic Profiles in a Chinese Population: A Combined Untargeted and Targeted Metabolomics Study

PubMed Central

Lu, Yonghai; Zou, Li; Su, Jin; Tai, E. Shyong; Whitton, Clare; van Dam, Rob M.; Ong, Choon Nam

2017-01-01

We examined the relationship between different patterns of meat and seafood consumption and plasma metabolic profiles in an Asian population. We selected 270 ethnic Chinese men and women from the Singapore Prospective Study Program based on their dietary habits assessed with a validated food frequency questionnaire. Participants were divided into four subgroups: high meat and high seafood (n = 60), high meat and low seafood (n = 64), low meat and high seafood (n = 60), and low meat and low seafood (n = 86) consumers. Plasma metabolites were measured using both targeted and untargeted mass spectroscopy-based analyses. A total of 42 metabolites differed significantly by dietary group. Higher concentrations of essential amino acids, polyunsaturated fatty acids, and d-glucose were found in high meat and/or seafood consumers as compared with the group with a low consumption of these animal foods. Red meat, poultry, fish, shellfish, soy products, and dairy were each correlated with at least one differential metabolite (r = −0.308 to 0.448). Some observations, such as the correlation between fish and 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), confirmed previous studies. Other observations, such as the correlation between shellfish and phosphatidylethanolamine (p36:4), were novel. We also observed significant correlations between plasma metabolites and clinical characteristics, such as CMPF with fasting blood glucose (r = 0.401). These findings demonstrate a significant influence of meat and seafood consumption on metabolic profiles in the Asian population. PMID:28665358

No evidence of response bias in a population-based childhood cancer survivor questionnaire survey — Results from the Swiss Childhood Cancer Survivor Study

PubMed Central

Gianinazzi, Micòl E.; Michel, Gisela; Zwahlen, Marcel; von der Weid, Nicolas X.; Kuehni, Claudia E.

2017-01-01

Purpose This is the first study to quantify potential nonresponse bias in a childhood cancer survivor questionnaire survey. We describe early and late responders and nonresponders, and estimate nonresponse bias in a nationwide questionnaire survey of survivors. Methods In the Swiss Childhood Cancer Survivor Study, we compared characteristics of early responders (who answered an initial questionnaire), late responders (who answered after ≥1 reminder) and nonresponders. Sociodemographic and cancer-related information was available for the whole population from the Swiss Childhood Cancer Registry. We compared observed prevalence of typical outcomes in responders to the expected prevalence in a complete (100% response) representative population we constructed in order to estimate the effect of nonresponse bias. We constructed the complete population using inverse probability of participation weights. Results Of 2328 survivors, 930 returned the initial questionnaire (40%); 671 returned the questionnaire after ≥1reminder (29%). Compared to early and late responders, we found that the 727 nonresponders (31%) were more likely male, aged <20 years, French or Italian speaking, of foreign nationality, diagnosed with lymphoma or a CNS or germ cell tumor, and treated only with surgery. But observed prevalence of typical estimates (somatic health, medical care, mental health, health behaviors) was similar among the sample of early responders (40%), all responders (69%), and the complete representative population (100%). In this survey, nonresponse bias did not seem to influence observed prevalence estimates. Conclusion Nonresponse bias may play only a minor role in childhood cancer survivor studies, suggesting that results can be generalized to the whole population of such cancer survivors and applied in clinical practice. PMID:28463966

Education, the Brain and Dementia: Neuroprotection or Compensation?

ERIC Educational Resources Information Center

Brayne, Carol; Ince, Paul G.; Keage, Hannah A. D.; McKeith, Ian G.; Matthews, Fiona E.; Polvikoski, Tuomo; Sulkava, Raimo

2010-01-01

The potential protective role of education for dementia is an area of major interest. Almost all older people have some pathology in their brain at death but have not necessarily died with dementia. We have explored these two observations in large population-based cohort studies (Epidemiological Clinicopathological Studies in Europe; EClipSE) in…

Backpacking with a Prayer: Tradition and Modernity

ERIC Educational Resources Information Center

Davidovitch, Nitza

2016-01-01

This study focuses on the phenomenon of Israeli backpacking as a function of traditional, observant, and secular population segments. We explored whether and to what degree backpacking features are related to the affinity of backpackers with the Jewish tradition and faith. Our study was based on a sample of 120 Israeli backpackers who had returned…

Steps Toward Identifying PAHs: A Child's Garden of Recent Results

NASA Technical Reports Server (NTRS)

Hudgins, Douglas M.

2005-01-01

Based on over two decades of experimental, observational and theoretical studies by scientists around the world. It is now widely accepted that the composite emission of mixtures of vibrationally-excited PAHs and PAH ions can accommodate the general pattern of band positions, intensities, and profiles observed in the discreet IR emission features of carbon-rich interstellar dust, as well as the variations in those characteristics. These variations provide insight into the detailed nature of the emitting PAH population and reflect conditions within the emitting regions giving the population enormous potential as probes of astrophysical environments. Moreover, the ubiquity and abundance of this material has impacts that extend well beyond the IR. In this presentation we will examine recent, combined experimental, theoretical, and observational studies that indicate that nitrogen-substituted PAHs represent an important component of the interstellar dust population, and we will go on to explore some of the ramifications of this result. We will also explore the results of recent experimental studies of the strong, low-lying electronic transitions of ionized PAH ions in the Near-IR (0.7 - 2.5 microns) and explore the role that these transitions might play in pumping the PAH IR emission in regions of low-excitation.

Towards A Complete Census of the Compton-thick AGN population and the NH Distribution of AGN in the Local Universe.

NASA Astrophysics Data System (ADS)

Annuar, A.

2015-09-01

We present updated results from an ongoing project to establish the most unbiased census of the Compton- thick active galactic nucleus (CTAGN) population and the intrinsic column density (NH) distribution of the overall AGN population in the local universe, using a sample of mid-infrared (mid-IR) selected AGN within 15 Mpc. We find that 20% of the AGN in the sample are bona-fide CTAGN based upon hard X-ray studies (E > 10 keV). More candidates are then selected using multiwavelength techniques, i.e. mid-IR:X-ray and optical [OIII]5007:X-ray flux ratios. Based on these analyses along with evidence from previous literature, we initially find a further 25% of potential candidates. We then observed two of these candidates, NGC 5643 and NGC 3486, using NuSTAR and is able to confirm the former as a CTAGN and rule out the latter as an obscured AGN. This constrains the total CTAGN population in the sample to 25-40%, though it could potentially be as high as 65% accounting for those that still lack data. Finally, we use these results to estimate the intrinsic NH distribution of the local AGN population. Two more of our CTAGN candidates are scheduled to be observed by NuSTAR, bringing the completeness of hard X-ray energy data of the sample to 65%. This work provides a well-defined local benchmark for AGN unification studies.

[Impact of Morbidity on Health Care Costs of a Department of Health through Clinical Risk Groups. Valencian Community, Spain].

PubMed

Caballer Tarazona, Vicent; Guadalajara Olmeda, Natividad; Vivas Consuelo, David; Clemente Collado, Antonio

2016-06-08

Risk adjustment systems based on diagnosis stratify the population according to the observed morbidity. The aim of this study was to analyze the total health expenditure in a health area, relating to age, gender and morbidity observed in the population. Observational cross-sectional study of population and area of health care costs in the Health District of Denia-Marina Salud (Alicante) in 2013. Population (N=156,811) were stratified by Clinical Risk Groups into 9 states of health, state 1 being healthy, and state 9 the highest disease burden. Each inhabitant was charged with the hospital costs, primary care and outpatient pharmacy to obtain the total costs. Health status and severity by age and gender, as well as the costs of each group were analysed. The statistical tests, student t and χ2 were applied to verify the existence of significant differences between and intra groups. The average cost per inhabitant was 983 euros which increased from 240 euros to 42,881 at the state 9 and severity level 6. Patients of health states 5 and 6 caused the largest expenditure by concentration of the population, but health states 8 and 9 had the highest average expenditure, with 80% of hospitalised cost. A different composition of health expenditure per individual morbidity was corroborated, with an exponential growth in hospital spending.

Genotyping faecal samples of Bengal tiger Panthera tigris tigris for population estimation: a pilot study.

PubMed

Bhagavatula, Jyotsna; Singh, Lalji

2006-10-17

Bengal tiger Panthera tigris tigris the National Animal of India, is an endangered species. Estimating populations for such species is the main objective for designing conservation measures and for evaluating those that are already in place. Due to the tiger's cryptic and secretive behaviour, it is not possible to enumerate and monitor its populations through direct observations; instead indirect methods have always been used for studying tigers in the wild. DNA methods based on non-invasive sampling have not been attempted so far for tiger population studies in India. We describe here a pilot study using DNA extracted from faecal samples of tigers for the purpose of population estimation. In this study, PCR primers were developed based on tiger-specific variations in the mitochondrial cytochrome b for reliably identifying tiger faecal samples from those of sympatric carnivores. Microsatellite markers were developed for the identification of individual tigers with a sibling Probability of Identity of 0.005 that can distinguish even closely related individuals with 99.9% certainty. The effectiveness of using field-collected tiger faecal samples for DNA analysis was evaluated by sampling, identification and subsequently genotyping samples from two protected areas in southern India. Our results demonstrate the feasibility of using tiger faecal matter as a potential source of DNA for population estimation of tigers in protected areas in India in addition to the methods currently in use.

Local Adaptation at the Transcriptome Level in Brown Trout: Evidence from Early Life History Temperature Genomic Reaction Norms

PubMed Central

Meier, Kristian; Hansen, Michael Møller; Normandeau, Eric; Mensberg, Karen-Lise D.; Frydenberg, Jane; Larsen, Peter Foged; Bekkevold, Dorte; Bernatchez, Louis

2014-01-01

Local adaptation and its underlying molecular basis has long been a key focus in evolutionary biology. There has recently been increased interest in the evolutionary role of plasticity and the molecular mechanisms underlying local adaptation. Using transcriptome analysis, we assessed differences in gene expression profiles for three brown trout (Salmo trutta) populations, one resident and two anadromous, experiencing different temperature regimes in the wild. The study was based on an F2 generation raised in a common garden setting. A previous study of the F1 generation revealed different reaction norms and significantly higher QST than FST among populations for two early life-history traits. In the present study we investigated if genomic reaction norm patterns were also present at the transcriptome level. Eggs from the three populations were incubated at two temperatures (5 and 8 degrees C) representing conditions encountered in the local environments. Global gene expression for fry at the stage of first feeding was analysed using a 32k cDNA microarray. The results revealed differences in gene expression between populations and temperatures and population × temperature interactions, the latter indicating locally adapted reaction norms. Moreover, the reaction norms paralleled those observed previously at early life-history traits. We identified 90 cDNA clones among the genes with an interaction effect that were differently expressed between the ecologically divergent populations. These included genes involved in immune- and stress response. We observed less plasticity in the resident as compared to the anadromous populations, possibly reflecting that the degree of environmental heterogeneity encountered by individuals throughout their life cycle will select for variable level of phenotypic plasticity at the transcriptome level. Our study demonstrates the usefulness of transcriptome approaches to identify genes with different temperature reaction norms. The responses observed suggest that populations may vary in their susceptibility to climate change. PMID:24454810

Linkage disequilibrium, SNP frequency change due to selection, and association mapping in popcorn chromosome regions containing QTLs for quality traits

PubMed Central

Paes, Geísa Pinheiro; Viana, José Marcelo Soriano; Silva, Fabyano Fonseca e; Mundim, Gabriel Borges

2016-01-01

Abstract The objectives of this study were to assess linkage disequilibrium (LD) and selection-induced changes in single nucleotide polymorphism (SNP) frequency, and to perform association mapping in popcorn chromosome regions containing quantitative trait loci (QTLs) for quality traits. Seven tropical and two temperate popcorn populations were genotyped for 96 SNPs chosen in chromosome regions containing QTLs for quality traits. The populations were phenotyped for expansion volume, 100-kernel weight, kernel sphericity, and kernel density. The LD statistics were the difference between the observed and expected haplotype frequencies (D), the proportion of D relative to the expected maximum value in the population, and the square of the correlation between the values of alleles at two loci. Association mapping was based on least squares and Bayesian approaches. In the tropical populations, D-values greater than 0.10 were observed for SNPs separated by 100-150 Mb, while most of the D-values in the temperate populations were less than 0.05. Selection for expansion volume indirectly led to increase in LD values, population differentiation, and significant changes in SNP frequency. Some associations were observed for expansion volume and the other quality traits. The candidate genes are involved with starch, storage protein, lipid, and cell wall polysaccharides synthesis. PMID:27007903

Linkage disequilibrium, SNP frequency change due to selection, and association mapping in popcorn chromosome regions containing QTLs for quality traits.

PubMed

Paes, Geísa Pinheiro; Viana, José Marcelo Soriano; Silva, Fabyano Fonseca E; Mundim, Gabriel Borges

2016-03-01

The objectives of this study were to assess linkage disequilibrium (LD) and selection-induced changes in single nucleotide polymorphism (SNP) frequency, and to perform association mapping in popcorn chromosome regions containing quantitative trait loci (QTLs) for quality traits. Seven tropical and two temperate popcorn populations were genotyped for 96 SNPs chosen in chromosome regions containing QTLs for quality traits. The populations were phenotyped for expansion volume, 100-kernel weight, kernel sphericity, and kernel density. The LD statistics were the difference between the observed and expected haplotype frequencies (D), the proportion of D relative to the expected maximum value in the population, and the square of the correlation between the values of alleles at two loci. Association mapping was based on least squares and Bayesian approaches. In the tropical populations, D-values greater than 0.10 were observed for SNPs separated by 100-150 Mb, while most of the D-values in the temperate populations were less than 0.05. Selection for expansion volume indirectly led to increase in LD values, population differentiation, and significant changes in SNP frequency. Some associations were observed for expansion volume and the other quality traits. The candidate genes are involved with starch, storage protein, lipid, and cell wall polysaccharides synthesis.

Cancer incidence among population utilizing geothermal hot water: a census-based cohort study.

PubMed

Kristbjornsdottir, Adalbjorg; Rafnsson, Vilhjalmur

2013-12-15

The aim of the study was to assess whether utilization of geothermal hot-water is associated with risk of cancer. The cohort from census was followed from 1981 to 2010 in nation-wide death and cancer registries. The moving apart of American-Eurasian tectonic plates, observed in Iceland, results in high volcanic activity. The definition of the study populations was based on geological information. The target population was inhabitants of communities located on bedrock younger than 3.3 million years, utilizing hot-water supply generated from geothermal wells since 1972. The two reference populations were inhabitants of communities without this hot-water supply located on areas with less volcanic/geothermal activity, and bedrock older than 3.3 million years. Hazard ratio (HR), and 95% confidence intervals (CI) were adjusted for age, gender, education, housing, reproductive factors and smoking. HR in the geothermal hot-water supply areas for all cancer was 1.15 (95% CI 1.05-1.25) as compared with nongeothermal areas. The HR for breast cancer was 1.40 (1.12-1.75), prostate cancer 1.61 (1.29-2.00), kidney cancer 1.64 (1.11-2.41), lymphatic and haematopoietic tissue cancers 1.45 (1.08-1.95), and for basal cell carcinoma (BCC) of the skin 1.46 (1.16-1.82). Positive exposure-response relations were observed between the risk of these cancers and the degree of volcanic/geothermal activity in the reference areas. Increased incidence of all cancers, breast, prostate, kidney cancer and BCC of the skin was found among the population utilizing geothermal hot-water for decades. More precise information on exposure is needed in future studies. Copyright © 2013 UICC.

Estimation of Untracked Geosynchronous Population from Short-Arc Angles-Only Observations

NASA Technical Reports Server (NTRS)

Healy, Liam; Matney, Mark

2017-01-01

Telescope observations of the geosynchronous regime will observe two basic types of objects --- objects related to geosynchronous earth orbit (GEO) satellites, and objects in highly elliptical geosynchronous transfer orbits (GTO). Because telescopes only measure angular rates, the GTO can occasionally mimic the motion of GEO objects over short arcs. A GEO census based solely on short arc telescope observations may be affected by these ``interlopers''. A census that includes multiple angular rates can get an accurate statistical estimate of the GTO population, and that then can be used to correct the estimate of the geosynchronous earth orbit population.

Exposure to ambient air pollution and the incidence of dementia: A population-based cohort study.

PubMed

Chen, Hong; Kwong, Jeffrey C; Copes, Ray; Hystad, Perry; van Donkelaar, Aaron; Tu, Karen; Brook, Jeffrey R; Goldberg, Mark S; Martin, Randall V; Murray, Brian J; Wilton, Andrew S; Kopp, Alexander; Burnett, Richard T

2017-11-01

Emerging studies have implicated air pollution in the neurodegenerative processes. Less is known about the influence of air pollution, especially at the relatively low levels, on developing dementia. We conducted a population-based cohort study in Ontario, Canada, where the concentrations of pollutants are among the lowest in the world, to assess whether air pollution exposure is associated with incident dementia. The study population comprised all Ontario residents who, on 1 April 2001, were 55-85years old, Canadian-born, and free of physician-diagnosed dementia (~2.1 million individuals). Follow-up extended until 2013. We used population-based health administrative databases with a validated algorithm to ascertain incident diagnosis of dementia as well as prevalent cases. Using satellite observations, land-use regression model, and an optimal interpolation method, we derived long-term average exposure to fine particulate matter (≤2.5μm in diameter) (PM 2.5 ), nitrogen dioxide (NO 2 ), and ozone (O 3 ), respectively at the subjects' historical residences based on a population-based registry. We used multilevel spatial random-effects Cox proportional hazards models, adjusting for individual and contextual factors, such as diabetes, brain injury, and neighborhood income. We conducted various sensitivity analyses, such as lagging exposure up to 10years and considering a negative control outcome for which no (or weaker) association with air pollution is expected. We identified 257,816 incident cases of dementia in 2001-2013. We found a positive association between PM 2.5 and dementia incidence, with a hazard ratio (HR) of 1.04 (95% confidence interval (CI): 1.03-1.05) for every interquartile-range increase in exposure to PM 2.5 . Similarly, NO 2 was associated with increased incidence of dementia (HR=1.10; 95% CI: 1.08-1.12). No association was found for O 3 . These associations were robust to all sensitivity analyses examined. These estimates translate to 6.1% of dementia cases (or 15,813 cases) attributable to PM 2.5 and NO 2 , based on the observed distribution of exposure relative to the lowest quartile in concentrations in this cohort. In this large cohort, exposure to air pollution, even at the relative low levels, was associated with higher dementia incidence. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

European Population Substructure: Clustering of Northern and Southern Populations

PubMed Central

Seldin, Michael F; Shigeta, Russell; Villoslada, Pablo; Selmi, Carlo; Tuomilehto, Jaakko; Silva, Gabriel; Belmont, John W; Klareskog, Lars; Gregersen, Peter K

2006-01-01

Using a genome-wide single nucleotide polymorphism (SNP) panel, we observed population structure in a diverse group of Europeans and European Americans. Under a variety of conditions and tests, there is a consistent and reproducible distinction between “northern” and “southern” European population groups: most individual participants with southern European ancestry (Italian, Spanish, Portuguese, and Greek) have >85% membership in the “southern” population; and most northern, western, eastern, and central Europeans have >90% in the “northern” population group. Ashkenazi Jewish as well as Sephardic Jewish origin also showed >85% membership in the “southern” population, consistent with a later Mediterranean origin of these ethnic groups. Based on this work, we have developed a core set of informative SNP markers that can control for this partition in European population structure in a variety of clinical and genetic studies. PMID:17044734

Mammary tumor associated Hspb1 mutation and screening of eight cat populations of the world.

PubMed

Saif, R; Awan, A R; Lyons, L; Gandolfi, B; Tayyab, M; Ellahi Babar, M; Wasim, M

2016-01-01

Current research highlights the Hspb1 based screening of eight cat populations of the world to investigate the association of newly found locus within cat mammary tumors. Total 180 cats were screened on the basis of Hspb1 4 bp deletion locus (1514-1517del4) which was observed in six mammary tumor cases in Siamese cat breed. Case-control association study revealed the non-significance with P=0.201 and an overall mutant allele frequency of 0.30 ranging from 0.20-0.40 was observed in other cat populations. Similarly, HWE was also obeyed in combined population samples with P=0.860 and found non-significant with range of 0.429-0.708 in other non-Pakistani cat populations as well. These results might be helpful to understand the association of this novel locus in a better way with large sample size of cases and may also serve as a potential marker for mammary tumor diagnosis, particularly in cats and generally in all other animal populations in comparative genetics and genomics context.

Census-independent population mapping in northern Nigeria

DOE PAGES

Weber, Eric M.; Seaman, Vincent Y.; Stewart, Robert N.; ...

2017-10-21

Although remote sensing has long been used to aid in the estimation of population, it has usually been in the context of spatial disaggregation of national census data, with the census counts serving both as observational data for specifying models and as constraints on model outputs. Here we present a framework for estimating populations from the bottom up, entirely independently of national census data, a critical need in areas without recent and reliable census data. To make observations of population density, we replace national census data with a microcensus, in which we enumerate population for a sample of small areasmore » within the states of Kano and Kaduna in northern Nigeria. Using supervised texture-based classifiers with very high resolution satellite imagery, we produce a binary map of human settlement at 8-meter resolution across the two states and then a more refined classification consisting of 7 residential types and 1 non-residential type. Using the residential types and a model linking them to the population density observations, we produce population estimates across the two states in a gridded raster format, at approximately 90-meter resolution. We also demonstrate a simulation framework for capturing uncertainty and presenting estimates as prediction intervals for any region of interest of any size and composition within the study region. As a result, used in concert with previously published demographic estimates, our population estimates allowed for predictions of the population under 5 in ten administrative wards that fit strongly with reference data collected during polio vaccination campaigns.« less

Census-independent population mapping in northern Nigeria

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, Eric M.; Seaman, Vincent Y.; Stewart, Robert N.

Although remote sensing has long been used to aid in the estimation of population, it has usually been in the context of spatial disaggregation of national census data, with the census counts serving both as observational data for specifying models and as constraints on model outputs. Here we present a framework for estimating populations from the bottom up, entirely independently of national census data, a critical need in areas without recent and reliable census data. To make observations of population density, we replace national census data with a microcensus, in which we enumerate population for a sample of small areasmore » within the states of Kano and Kaduna in northern Nigeria. Using supervised texture-based classifiers with very high resolution satellite imagery, we produce a binary map of human settlement at 8-meter resolution across the two states and then a more refined classification consisting of 7 residential types and 1 non-residential type. Using the residential types and a model linking them to the population density observations, we produce population estimates across the two states in a gridded raster format, at approximately 90-meter resolution. We also demonstrate a simulation framework for capturing uncertainty and presenting estimates as prediction intervals for any region of interest of any size and composition within the study region. As a result, used in concert with previously published demographic estimates, our population estimates allowed for predictions of the population under 5 in ten administrative wards that fit strongly with reference data collected during polio vaccination campaigns.« less

Genome-wide linkage disequilibrium and genetic diversity in five populations of Australian domestic sheep.

PubMed

Al-Mamun, Hawlader Abdullah; Clark, Samuel A; Kwan, Paul; Gondro, Cedric

2015-11-24

Knowledge of the genetic structure and overall diversity of livestock species is important to maximise the potential of genome-wide association studies and genomic prediction. Commonly used measures such as linkage disequilibrium (LD), effective population size (N e ), heterozygosity, fixation index (F ST) and runs of homozygosity (ROH) are widely used and help to improve our knowledge about genetic diversity in animal populations. The development of high-density single nucleotide polymorphism (SNP) arrays and the subsequent genotyping of large numbers of animals have greatly increased the accuracy of these population-based estimates. In this study, we used the Illumina OvineSNP50 BeadChip array to estimate and compare LD (measured by r (2) and D'), N e , heterozygosity, F ST and ROH in five Australian sheep populations: three pure breeds, i.e., Merino (MER), Border Leicester (BL), Poll Dorset (PD) and two crossbred populations i.e. F1 crosses of Merino and Border Leicester (MxB) and MxB crossed to Poll Dorset (MxBxP). Compared to other livestock species, the sheep populations that were analysed in this study had low levels of LD and high levels of genetic diversity. The rate of LD decay was greater in Merino than in the other pure breeds. Over short distances (<10 kb), the levels of LD were higher in BL and PD than in MER. Similarly, BL and PD had comparatively smaller N e than MER. Observed heterozygosity in the pure breeds ranged from 0.3 in BL to 0.38 in MER. Genetic distances between breeds were modest compared to other livestock species (highest F ST = 0.063) but the genetic diversity within breeds was high. Based on ROH, two chromosomal regions showed evidence of strong recent selection. This study shows that there is a large range of genome diversity in Australian sheep breeds, especially in Merino sheep. The observed range of diversity will influence the design of genome-wide association studies and the results that can be obtained from them. This knowledge will also be useful to design reference populations for genomic prediction of breeding values in sheep.

Determinants of inequalities in the quality of Brazilian diet: trends in 12-year population-based study (2003-2015).

PubMed

Mello, Aline Veroneze de; Sarti, Flávia Mori; Pereira, Jaqueline Lopes; Goldbaum, Moisés; Cesar, Chester Luiz Galvão; Alves, Maria Cecilia Goi Porto; Fisberg, Regina Mara

2018-06-07

Recent studies have explored the influence of socioeconomic inequalities on the diet quality. However, there is lack of evidence regarding the level of inequalities in dietary quality and its main contributing factors from population-based follow-up studies. The primary objective of this study was to investigate the level and the determinants of inequalities in diet quality in a representative sample of adolescents, adults and older adults resident in São Paulo, Brazil. Data from the Health Survey of São Paulo (ISA-Capital) were analyzed for 2003 (n = 2398), 2008 (n = 1662) and 2015 (n = 1742) surveys. Information on food consumption was obtained through 24-h dietary recall, and diet quality was assessed based on the Revised Brazilian Healthy Eating Index (BHEI-R). The descriptive variables were compared using 95% confidence interval. The scores of BHEI-R and its components were compared across age groups and year. The association between socioeconomic inequalities and diet quality was based on the estimation of concentration index. We observed that the BHEI-R scores gradually improved over 12-years, with older adults showing the greatest improvement. The increase in overall population score was observed for total fruits, whole fruits, whole grains, oils and sodium. The main contributor to socioeconomic inequality in diet quality in 2003 was ethnic group, and in 2008 and 2015, it was per capita household income; age was a persistent factor of inequality in the population over the years. Concentration indices indicated that lower income individuals had higher BHEI-R scores in 2003; however, there was a shift in favor of higher income individuals in 2008 and 2015. Changes in the patterns of determination of inequalities according to age, ethnic group or income during the period analyzed show the existence of ongoing process of contribution of demographic and socioeconomic factors in the diet quality of individuals in a large urban center.

Whole genome sequencing and imputation in isolated populations identify genetic associations with medically-relevant complex traits

PubMed Central

Southam, Lorraine; Gilly, Arthur; Süveges, Dániel; Farmaki, Aliki-Eleni; Schwartzentruber, Jeremy; Tachmazidou, Ioanna; Matchan, Angela; Rayner, Nigel W.; Tsafantakis, Emmanouil; Karaleftheri, Maria; Xue, Yali; Dedoussis, George; Zeggini, Eleftheria

2017-01-01

Next-generation association studies can be empowered by sequence-based imputation and by studying founder populations. Here we report ∼9.5 million variants from whole-genome sequencing (WGS) of a Cretan-isolated population, and show enrichment of rare and low-frequency variants with predicted functional consequences. We use a WGS-based imputation approach utilizing 10,422 reference haplotypes to perform genome-wide association analyses and observe 17 genome-wide significant, independent signals, including replicating evidence for association at eight novel low-frequency variant signals. Two novel cardiometabolic associations are at lead variants unique to the founder population sequences: chr16:70790626 (high-density lipoprotein levels beta −1.71 (SE 0.25), P=1.57 × 10−11, effect allele frequency (EAF) 0.006); and rs145556679 (triglycerides levels beta −1.13 (SE 0.17), P=2.53 × 10−11, EAF 0.013). Our findings add empirical support to the contribution of low-frequency variants in complex traits, demonstrate the advantage of including population-specific sequences in imputation panels and exemplify the power gains afforded by population isolates. PMID:28548082

[Inverse probability weighting (IPW) for evaluating and "correcting" selection bias].

PubMed

Narduzzi, Silvia; Golini, Martina Nicole; Porta, Daniela; Stafoggia, Massimo; Forastiere, Francesco

2014-01-01

the Inverse probability weighting (IPW) is a methodology developed to account for missingness and selection bias caused by non-randomselection of observations, or non-random lack of some information in a subgroup of the population. to provide an overview of IPW methodology and an application in a cohort study of the association between exposure to traffic air pollution (nitrogen dioxide, NO₂) and 7-year children IQ. this methodology allows to correct the analysis by weighting the observations with the probability of being selected. The IPW is based on the assumption that individual information that can predict the probability of inclusion (non-missingness) are available for the entire study population, so that, after taking account of them, we can make inferences about the entire target population starting from the nonmissing observations alone.The procedure for the calculation is the following: firstly, we consider the entire population at study and calculate the probability of non-missing information using a logistic regression model, where the response is the nonmissingness and the covariates are its possible predictors.The weight of each subject is given by the inverse of the predicted probability. Then the analysis is performed only on the non-missing observations using a weighted model. IPW is a technique that allows to embed the selection process in the analysis of the estimates, but its effectiveness in "correcting" the selection bias depends on the availability of enough information, for the entire population, to predict the non-missingness probability. In the example proposed, the IPW application showed that the effect of exposure to NO2 on the area of verbal intelligence quotient of children is stronger than the effect showed from the analysis performed without regard to the selection processes.

Analysis of umbu (Spondias tuberosa Arruda (Anacardiaceae)) in different landscape management regimes: a process of incipient domestication?

PubMed

Lins Neto, Ernani Machado de Freitas; Peroni, Nivaldo; Maranhão, Christine Maria Carneiro; Maciel, Maria Inês Sucupira; de Albuquerque, Ulysses Paulino

2012-07-01

Plant domestication is an evolutionary process guided by human groups who modify the landscape for their needs. The objective of this study was to evaluate the phenotypic variations between populations of Spondias tuberosa Arruda (umbuzeiro) when subjected to different local landscape management strategies. The influence of the landscape management system on these populations was evaluated in five identified regional units (mountains, base of mountains, pastures, cultivated areas and home gardens). Ten individuals were randomly selected from each region and subjected to morphological and chemical fruit analysis. The diversity index, based on Simpson's index, was determined for the different populations. We then evaluated the morphological differences between the individual fruits from the distinct landscape areas. We observed no significant differences in morphological diversity between the areas studied. Our data suggest that the umbuzeiro specimens in this region may be in the process of incipient domestication.

Genetic diversity and population structure in Bactrocera correcta (Diptera: Tephritidae) inferred from mtDNA cox1 and microsatellite markers

PubMed Central

Qin, Yu-Jia; Buahom, Nopparat; Krosch, Matthew N.; Du, Yu; Wu, Yi; Malacrida, Anna R.; Deng, Yu-Liang; Liu, Jia-Qi; Jiang, Xiao-Long; Li, Zhi-Hong

2016-01-01

Bactrocera correcta is one of the most destructive pests of horticultural crops in tropical and subtropical regions. Despite the economic risk, the population genetics of this pest have remained relatively unexplored. This study explores population genetic structure and contemporary gene flow in B. correcta in Chinese Yunnan Province and attempts to place observed patterns within the broader geographical context of the species’ total range. Based on combined data from mtDNA cox1 sequences and 12 microsatellite loci obtained from 793 individuals located in 7 countries, overall genetic structuring was low. The expansion history of this species, including likely human-mediated dispersal, may have played a role in shaping the observed weak structure. The study suggested a close relationship between Yunnan Province and adjacent countries, with evidence for Western and/or Southern Yunnan as the invasive origin of B. correcta within Yunnan Province. The information gleaned from this analysis of gene flow and population structure has broad implications for quarantine, trade and management of this pest, especially in China where it is expanding northward. Future studies should concentrate effort on sampling South Asian populations, which would enable better inferences of the ancestral location of B. correcta and its invasion history into and throughout Asia. PMID:27929126

Experimental reintroduction of the federally endangered Santa Cruz Island bush mallow (Malacothamnus fasciculatus var. nestioticus)

USGS Publications Warehouse

Wilken, D.H.; McEachern, K.

2011-01-01

Studies of Malacothamnus fasciculatus var. nesioticus were begun in 1995 to understand its distribution, reproductive biology and ecological requirements. After 100+ years of depredation by sheep, two known populations of fewer than 20 plants each survived in 1995. Molecular studies showed that each of the two populations was composed of 1–3 genets. During our study, two additional populations of similar size were discovered. Plants are self-compatible but require insect visitation to augment pollination. Based on seed set, viable embryos, and germination rates, we found no evidence for inbreeding depression. Bush mallow also reproduces vegetatively by rhizomes, the primary means of establishment and persistence in natural populations, and a key feature for maximizing recovery success. Ex situ observations and trial in situ outplantings suggested that supplemental watering was critical to initial survival. We developed a recovery strategy composed of four plots located at varying elevations and aspects. Each plot was enclosed to exclude feral pigs, which posed a continuing threat. Each plot was planted with twelve rooted plants derived from each of three natural populations. Plants were provided supplemental watering for four months. Survivorship after one year ranged from 46% to 91%. Significant differences in survivorship were observed relative to source of plants. After twelve months some plants were flowering and reproducing vegetatively.

Identifying instruments to quantify financial management skills in adults with acquired cognitive impairments.

PubMed

Engel, Lisa; Bar, Yael; Beaton, Dorcas E; Green, Robin E; Dawson, Deirdre R

2016-01-01

Financial management skills-that is, the skills needed to handle personal finances such as banking and paying bills-are essential to a person's autonomy, independence, and community living. To date, no comprehensive review of financial management skills instruments exists, making it difficult for clinicians and researchers to choose relevant instruments. The objectives of this review are to: (a) identify all available instruments containing financial management skill items that have been used with adults with acquired cognitive impairments; (b) categorize the instruments by source (i.e., observation based, self-report, proxy report); and (c) describe observation-based performance instruments by populations, overarching concepts measured, and comprehensiveness of financial management items. Objective (c) focuses on observation-based performance instruments as these measures can aid in situations where the person with cognitive impairment has poor self-awareness or where the proxy has poor knowledge of the person's current abilities. Two reviewers completed two systematic searches of five databases. Instruments were categorized by reviewing published literature, copies of the instruments, and/or communication with instrument authors. Comprehensiveness of items was based on nine key domains of financial management skills developed by the authors. A total of 88 discrete instruments were identified. Of these, 44 were categorized as observation-based performance and 44 as self- and/or proxy-reports. Of the 44 observation-based performance instruments, 8 had been developed for acquired brain injury populations and 24 for aging and dementia populations. Only 7 of the observation-based performance instruments had items spanning 6 or more of the 9 financial management skills domains. The majority of instruments were developed for aging and dementia populations, and few were comprehensive. This review provides foundation for future instrument psychometric and clinimetric reviews. It a necessary first step in providing information to support decision making for clinicians and researchers selecting financial management skills instruments.

Structure of the New England herring gull population

USGS Publications Warehouse

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.

Comparative morphological studies on four populations of the shrimp Rimicaris exoculata from the Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Vereshchaka, A. L.

1997-11-01

Four populations (a total of 677 specimens) of the hydrothermal shrimp species Rimicaris exoculata from three Mid-Atlantic Ridge vent fields were studied: Broken Spur (29°N), TAG (26°N), and "14-45" (14°N). Five morphological characters were analysed: number of dorsolateral spines on telson, telative carapace width, relative abdominal length, presence of "abnormal telson", and fat content. Dependences of each character upon shrimp size were analysed. Division of the shrimp ontogenesis on the basis of general morphology is proposed. Phenotypic analysis based upon five selected characters revealed statistically significant divergence between two populations within the same vent field TAG. Probable causes of observed divergence are discussed.

Occupational Exposure to Electric Shocks and Magnetic Fields and Amyotrophic Lateral Sclerosis in Sweden.

PubMed

Fischer, Heidi; Kheifets, Leeka; Huss, Anke; Peters, Tracy L; Vermeulen, Roel; Ye, Weimin; Fang, Fang; Wiebert, Pernilla; Vergara, Ximena P; Feychting, Maria

2015-11-01

Amyotrophic lateral sclerosis (ALS) has been consistently related to "electric occupations," but associations with magnetic field levels were generally weaker than those with electrical occupations. Exposure to electric shock has been suggested as a possible explanation. Furthermore, studies were generally based on mortality or prevalence of ALS, and studies often had limited statistical power. Using two electric shock and three magnetic field job-exposure matrices, we evaluated the relationship of occupational magnetic fields, electric shocks, electric occupations, and incident ALS in a large population-based nested case-control study in Sweden. Subanalyses, specified a priori, were performed for subjects by gender and by age (less than and more than 65 years). Overall, we did not observe any associations between occupational magnetic field or electric shock exposure and ALS. For individuals less than 65 years old, high electric shock exposure was associated with an odds ratio (OR) of 1.22 (95% confidence interval [CI] = 1.03, 1.43). The corresponding result for the age group 65 years or older was OR = 0.92 (95% CI = 0.81, 1.05). Results were similar regardless which job exposure matrices, exposure definitions, or cutpoints were used. For electric occupations, ORs were close to unity, regardless of age. For welders, no association was observed overall, although for welders <65 years the OR was 1.52 (95% CI = 1.05, 2.21). In this very large population-based study based on incident ALS case subjects, we did not confirm previous observations of higher risk of ALS in electrical occupations, and provided only weak support for associations between electric shocks and ALS.

[The demographic evolution of homogeneous micro-regions in the period 1970-1980].

PubMed

De Souza Alf; Lana Rcds

1982-01-01

"The purpose of this study is to examine the demographic evolution of the Brazilian homogeneous microregions in the period 1970/80. It is based on the relative variations observed [in] the population as a whole.... Microregional unities were classified according to the intensity of their populational increase and loss. The different classes were spatially identified in order to establish the relation between demographic growth and the characteristics of the areas." (summary in ENG) excerpt

Drug prescription patterns in patients with Addison's disease: a Swedish population-based cohort study.

PubMed

Björnsdottir, Sigridur; Sundström, Anders; Ludvigsson, Jonas F; Blomqvist, Paul; Kämpe, Olle; Bensing, Sophie

2013-05-01

There are no published data on drug prescription in patients with Addison's disease (AD). Our objective was to describe the drug prescription patterns in Swedish AD patients before and after diagnosis compared with population controls. We conducted a population-based cohort study in Sweden. Through the Swedish National Patient Register and the Swedish Prescribed Drug Register, we identified 1305 patients with both a diagnosis of AD and on combination treatment with hydrocortisone/cortisone acetate and fludrocortisone. Direct evidence of the AD diagnosis from patient charts was not available. We identified 11 996 matched controls by the Register of Population. We determined the ratio of observed to expected number of patients treated with prescribed drugs. Overall, Swedish AD patients received more prescribed drugs than controls, and 59.3% of the AD patients had medications indicating concomitant autoimmune disease. Interestingly, both before and after the diagnosis of AD, patients used more gastrointestinal medications, antianemic preparations, lipid-modifying agents, antibiotics for systemic use, hypnotics and sedatives, and drugs for obstructive airway disease (all P values < .05). Notably, an increased prescription of several antihypertensive drugs and high-ceiling diuretics was observed after the diagnosis of AD. Gastrointestinal symptoms and anemia, especially in conjunction with autoimmune disorders, should alert the physician about the possibility of AD. The higher use of drugs for cardiovascular disorders after diagnosis in patients with AD raises concerns about the replacement therapy.

Study of Genetic Diversity among Simmental Cross Cattle in West Sumatra Based on Microsatellite Markers

PubMed Central

Agung, Paskah Partogi; Saputra, Ferdy; Septian, Wike Andre; Lusiana; Zein, Moch. Syamsul Arifin; Sulandari, Sri; Anwar, Saiful; Wulandari, Ari Sulistyo; Said, Syahruddin; Tappa, Baharuddin

2016-01-01

A study was conducted to assess the genetic diversity among Simmental Cross cattle in West Sumatra using microsatellite DNA markers. A total of 176 individual cattle blood samples was used for obtaining DNA samples. Twelve primers of microsatellite loci as recommended by FAO were used to identify the genetic diversity of the Simmental Cross cattle population. Multiplex DNA fragment analysis method was used for allele identification. All the microsatellite loci in this study were highly polymorphic and all of the identified alleles were able to classify the cattle population into several groups based on their genetic distance. The heterozygosity values of microsatellite loci in this study ranged from 0.556 to 0.782. The polymorphism information content (PIC) value of the 12 observed loci is high (PIC>0.5). The highest PIC value in the Simmental cattle population was 0.893 (locus TGLA53), while the lowest value was 0.529 (locus BM1818). Based on the genetic distance value, the subpopulation of the Simmental Cross-Agam and the Simmental Cross-Limapuluh Kota was exceptionally close to the Simmental Purebred thus indicating that a grading-up process has taken place with the Simmental Purebred. In view of the advantages possessed by the Simmental Cross cattle and the evaluation of the genetic diversity results, a number of subpopulations in this study can be considered as the initial (base) population for the Simmental Cross cattle breeding programs in West Sumatra, Indonesia. PMID:26732442

Analyzing ion distributions around DNA: sequence-dependence of potassium ion distributions from microsecond molecular dynamics

PubMed Central

Pasi, Marco; Maddocks, John H.; Lavery, Richard

2015-01-01

Microsecond molecular dynamics simulations of B-DNA oligomers carried out in an aqueous environment with a physiological salt concentration enable us to perform a detailed analysis of how potassium ions interact with the double helix. The oligomers studied contain all 136 distinct tetranucleotides and we are thus able to make a comprehensive analysis of base sequence effects. Using a recently developed curvilinear helicoidal coordinate method we are able to analyze the details of ion populations and densities within the major and minor grooves and in the space surrounding DNA. The results show higher ion populations than have typically been observed in earlier studies and sequence effects that go beyond the nature of individual base pairs or base pair steps. We also show that, in some special cases, ion distributions converge very slowly and, on a microsecond timescale, do not reflect the symmetry of the corresponding base sequence. PMID:25662221

Bridging the gap between the randomised clinical trial world and the real world by combination of population-based registry and electronic health record data: A case study in haemato-oncology.

PubMed

Kibbelaar, R E; Oortgiesen, B E; van der Wal-Oost, A M; Boslooper, K; Coebergh, J W; Veeger, N J G M; Joosten, P; Storm, H; van Roon, E N; Hoogendoorn, M

2017-11-01

Randomised clinical trials (RCTs) are considered the basis of evidence-based medicine. It is recognised more and more that application of RCT results in daily practice of clinical decision-making is limited because the RCT world does not correspond with the clinical real world. Recent strategies aiming at substitution of RCT databases by improved population-based registries (PBRs) or by improved electronic health record (EHR) systems to provide significant data for clinical science are discussed. A novel approach exemplified by the HemoBase haemato-oncology project is presented. In this approach, a PBR is combined with an advanced EHR, providing high-quality data for observational studies and support of best practice development. This PBR + EHR approach opens a perspective on randomised registry trials. Copyright © 2017 Elsevier Ltd. All rights reserved.

VISIT-TS: A multimedia tool for population studies on tic disorders.

PubMed

Vachon, M Jonathan; Striley, Catherine W; Gordon, Mollie R; Schroeder, Miriam L; Bihun, Emily C; Koller, Jonathan M; Black, Kevin J

2016-01-01

Population-based assessment of Tourette syndrome (TS) and other tic disorders produces a paradox. On one hand, ideally diagnosis of tic disorders requires expert observation. In fact, diagnostic criteria for TS explicitly require expert assessment of tics for a definite diagnosis. On the other hand, large-scale population surveys with expert assessment of every subject are impracticable. True, several published studies have successfully used expert assessment to find tic prevalence in a representative population (e.g. all students in a school district). However, extending these studies to larger populations is daunting. We created a multimedia tool to demonstrate tics to a lay audience, discuss their defining and common attributes, and address features that differentiate tics from other movements and vocalizations. A first version was modified to improve clarity and to include a more diverse group in terms of age and ethnicity. The result is a tool intended for epidemiological research. It may also provide additional benefits, such as more representative minority recruitment for other TS studies and increased community awareness of TS.

Ischaemic heart disease mortality in Serbia, 1991-2013; a joinpoint analysis

PubMed Central

Ilic, Milena; Ilic, Irena

2017-01-01

Background & objectives: Ischaemic heart disease (IHD) has been one of the leading causes of mortality in the world. In many European countries the mortality rates due to IHD have been rising rapidly. This study was aimed to assess the IHD mortality trend in Serbia. Methods: A population-based cross-sectional study analyzing IHD mortality in Serbia in the period 1991-2013 was carried out based on official data. The age-standardized rates (ASRs, per 100,000) were calculated using the direct method, according to the European standard population. Joinpoint analysis was used to estimate the average annual percentage change (AAPC) with the corresponding 95 per cent confidence interval (CI). Results: More than 253,000 people (143,420 men and 110,276 women) died due to IHD in Serbia during the observed period, and most of them (over 160,000 people) were patients with myocardial infarction (MI). Average annual ASR for IHD was 113.6/100,000. There was no overall significant trend for mortality due to IHD (AAPC=+0.1%, 95% CI −0.8-1.0), but there was one joinpoint: the trend significantly increased by +2.3 per cent per year from 1991 to 2006 and then significantly decreased by −6.4 per cent from 2006 to onwards. Significantly decreased mortality trends for MI in both genders were observed: according to the comparability test, mortality trends in men and women were parallel (final selected model failed to reject parallelism, P=0.0567). Interpretation & conclusions: No significant trend for mortality due to IHD was observed in Serbia during the study period. The substantial decline of mortality from IHD seen in most developed countries during the past decades was not observed in Serbia. Further efforts are required to reduce mortality from IHD in Serbian population. PMID:29664033

Blood pressure reduction by reducing sodium intake in the population: one shoe fits all?

PubMed

Teo, Koon; Mente, Andrew

2014-07-01

Current guidelines, based on extrapolations of observational studies or short-term relatively small clinical trials, recommend that daily sodium intake should be around 2 g/day or less. The assumption is that the relationship between sodium consumption and blood pressure (BP) levels is linear in all populations. Recent development suggests this may not be correct. We reviewed the literature on the association between sodium reduction and BP lowering, and preliminary data on 100,000 individuals from the Prospective Urban Rural Epidemiology study on sodium excretion and the association of sodium excretion with BP in general populations from 17 countries in five continents, with a focus on major subgroups. Earlier observational studies have shown inconsistencies in their findings which were not addressed by the recommendations. The PURE results showed that associations between sodium intake and BP were not linear; proportionally, higher BP was found in individuals with higher sodium intake compared with those with lower sodium intake, in individuals with hypertension compared to those without hypertension, and in older individuals compared with younger individuals. Recent data do not support the recommendation that all populations should reduce their sodium intake to one low level.

Comparative analysis of premature mortality among urban immigrants in Bremen, Germany: a retrospective register-based linkage study.

PubMed

Makarova, Nataliya; Brand, Tilman; Brünings-Kuppe, Claudia; Pohlabeln, Hermann; Luttmann, Sabine

2016-03-21

The main objective of this study was to explore differences in mortality patterns among two large immigrant groups in Germany: one from Turkey and the other from the former Soviet Union (FSU). To this end, we investigated indicators of premature mortality. This study was conducted as a retrospective population-based study based on mortality register linkage. Using mortality data for the period 2004-2010, we calculated age-standardised death rates (SDR) and standardised mortality ratios (SMR) for premature deaths (

Comparative analysis of premature mortality among urban immigrants in Bremen, Germany: a retrospective register-based linkage study

PubMed Central

Makarova, Nataliya; Brand, Tilman; Brünings-Kuppe, Claudia; Pohlabeln, Hermann; Luttmann, Sabine

2016-01-01

Objectives The main objective of this study was to explore differences in mortality patterns among two large immigrant groups in Germany: one from Turkey and the other from the former Soviet Union (FSU). To this end, we investigated indicators of premature mortality. Design This study was conducted as a retrospective population-based study based on mortality register linkage. Using mortality data for the period 2004–2010, we calculated age-standardised death rates (SDR) and standardised mortality ratios (SMR) for premature deaths (

Stressful psychosocial factors and symptoms of gastroesophageal reflux disease: a population-based study in Norway.

PubMed

Jansson, Catarina; Wallander, Mari-Ann; Johansson, Saga; Johnsen, Roar; Hveem, Kristian

2010-01-01

Adverse psychosocial factors, including work-related stress, are, like gastroesophageal reflux disease (GERD), increasing health problems in industrialized countries. The importance of clarifying the relation between psychosocial factors and GERD has been stressed, but there are few population-based studies. This was a population-based, cross-sectional, case-control study based on two health surveys conducted in the Norwegian county Nord-Trondelag in 1984-86 and 1995-97. GERD symptoms were assessed in the second survey, which included 65,333 participants, representing 70% of the county's adult population. The 3153 persons reporting severe GERD symptoms were defined as cases and the 40,210 persons without such symptoms were defined as controls. Data on psychosocial factors and potential confounders were collected using questionnaires. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated using unconditional logistic regression. In models adjusted for age, sex, smoking, obesity and socioeconomic status, positive associations were observed between high job demands (OR 1.9, 95% CI 1.6-2.2), low job control (OR 1.1, 95% CI 1.0-1.2) and job strain (OR 1.9, 95% CI 1.6-2.4) and risk of GERD symptoms. Persons reporting low job satisfaction had a twofold (95% CI 1.6-2.5) increased risk of GERD compared to persons reporting high job satisfaction. Self pressure (OR 1.8, 95% CI 1.6-2.1) and time pressure (OR 2.0, 95% CI 1.7-2.4) were positively associated with GERD symptoms. These associations were attenuated after further adjustment for anxiety, depression, myocardial infarction, angina pectoris, stroke and insomnia, but remained statistically significant. This population-based study reveals a link between stressful psychosocial factors, including job strain, and GERD symptoms.

Exploring Population Admixture Dynamics via Empirical and Simulated Genome-wide Distribution of Ancestral Chromosomal Segments

PubMed Central

Jin, Wenfei; Wang, Sijia; Wang, Haifeng; Jin, Li; Xu, Shuhua

2012-01-01

The processes of genetic admixture determine the haplotype structure and linkage disequilibrium patterns of the admixed population, which is important for medical and evolutionary studies. However, most previous studies do not consider the inherent complexity of admixture processes. Here we proposed two approaches to explore population admixture dynamics, and we demonstrated, by analyzing genome-wide empirical and simulated data, that the approach based on the distribution of chromosomal segments of distinct ancestry (CSDAs) was more powerful than that based on the distribution of individual ancestry proportions. Analysis of 1,890 African Americans showed that a continuous gene flow model, in which the African American population continuously received gene flow from European populations over about 14 generations, best explained the admixture dynamics of African Americans among several putative models. Interestingly, we observed that some African Americans had much more European ancestry than the simulated samples, indicating substructures of local ancestries in African Americans that could have been caused by individuals from some particular lineages having repeatedly admixed with people of European ancestry. In contrast, the admixture dynamics of Mexicans could be explained by a gradual admixture model in which the Mexican population continuously received gene flow from both European and Amerindian populations over about 24 generations. Our results also indicated that recent gene flows from Sub-Saharan Africans have contributed to the gene pool of Middle Eastern populations such as Mozabite, Bedouin, and Palestinian. In summary, this study not only provides approaches to explore population admixture dynamics, but also advances our understanding on population history of African Americans, Mexicans, and Middle Eastern populations. PMID:23103229

Analysis of genotype diversity and evolution of Dengue virus serotype 2 using complete genomes

PubMed Central

Waman, Vaishali P.; Kolekar, Pandurang; Ramtirthkar, Mukund R.; Kale, Mohan M.

2016-01-01

Background Dengue is one of the most common arboviral diseases prevalent worldwide and is caused by Dengue viruses (genus Flavivirus, family Flaviviridae). There are four serotypes of Dengue Virus (DENV-1 to DENV-4), each of which is further subdivided into distinct genotypes. DENV-2 is frequently associated with severe dengue infections and epidemics. DENV-2 consists of six genotypes such as Asian/American, Asian I, Asian II, Cosmopolitan, American and sylvatic. Comparative genomic study was carried out to infer population structure of DENV-2 and to analyze the role of evolutionary and spatiotemporal factors in emergence of diversifying lineages. Methods Complete genome sequences of 990 strains of DENV-2 were analyzed using Bayesian-based population genetics and phylogenetic approaches to infer genetically distinct lineages. The role of spatiotemporal factors, genetic recombination and selection pressure in the evolution of DENV-2 is examined using the sequence-based bioinformatics approaches. Results DENV-2 genetic structure is complex and consists of fifteen subpopulations/lineages. The Asian/American genotype is observed to be diversified into seven lineages. The Asian I, Cosmopolitan and sylvatic genotypes were found to be subdivided into two lineages, each. The populations of American and Asian II genotypes were observed to be homogeneous. Significant evidence of episodic positive selection was observed in all the genes, except NS4A. Positive selection operational on a few codons in envelope gene confers antigenic and lineage diversity in the American strains of Asian/American genotype. Selection on codons of non-structural genes was observed to impact diversification of lineages in Asian I, cosmopolitan and sylvatic genotypes. Evidence of intra/inter-genotype recombination was obtained and the uncertainty in classification of recombinant strains was resolved using the population genetics approach. Discussion Complete genome-based analysis revealed that the worldwide population of DENV-2 strains is subdivided into fifteen lineages. The population structure of DENV-2 is spatiotemporal and is shaped by episodic positive selection and recombination. Intra-genotype diversity was observed in four genotypes (Asian/American, Asian I, cosmopolitan and sylvatic). Episodic positive selection on envelope and non-structural genes translates into antigenic diversity and appears to be responsible for emergence of strains/lineages in DENV-2 genotypes. Understanding of the genotype diversity and emerging lineages will be useful to design strategies for epidemiological surveillance and vaccine design. PMID:27635316

Multiple Stellar Populations in Star Clusters

NASA Astrophysics Data System (ADS)

Piotto, G.

2013-09-01

For half a century it had been astronomical dogma that a globular cluster (GC) consists of stars born at the same time out of the same material, and this doctrine has borne rich fruits. In recent years, high resolution spectroscopy and high precision photometry (from space and ground-based observations) have shattered this paradigm, and the study of GC populations has acquired a new life that is now moving it in new directions. Evidence of multiple stellar populations have been identified in the color-magnitude diagrams of several Galactic and Magellanic Cloud GCs where they had never been imagined before.

What Is the Real Public Health Significance of Iron Deficiency and Iron Deficiency Anaemia in Croatia? A Population-Based Observational Study on Pregnant Women at Early Pregnancy from Eastern Croatia.

PubMed

Banjari, Ines; Kenjerić, Daniela; Mandić, Milena L

2015-06-01

Studies imply that significance of iron deficiency (ID) and iron deficiency anaemia (IDA) for pregnancy outcomes is especially highlighted in the early pregnancy. Prevalence around the world varies widely, however, no data is available up to date for Croatia or neighbouring countries. Therefore, the objective was to determine the prevalence of ID and IDA among pregnant women from Croatia at the first trimester. Also, the aim was to compare two criterions; the World Health Organization (WHO) one and the clinical one. Randomised observational population based study was set up and 265 pregnant women at the first trimester were enrolled. Based on the WHO criteria, 17.7% on haemoglobin basis and 18.5% on haematocrit basis had either ID or IDA. Clinical criteria showed that even 32.8% had either ID or IDA (transferrin saturation <20.0%). The WHO criterion shows less sensitivity, especially in detecting less severe stages of IDA. Regardless of the criteria used, ID and IDA present a mild to moderate public health problem in pregnant women population. This high share of pregnant women who are starting their pregnancy as iron deficient, presents a potentially high risk for the pregnancy outcomes, especially in terms of a newborn, and it is fully justified to treat them as diseases of public health significance. Copyright© by the National Institute of Public Health, Prague 2015.

Phylogeography of the American woodcock (Scolopax minor): Are management units based on band recovery data reflected in genetically based management units?

USGS Publications Warehouse

Rhymer, J.M.; McAuley, D.G.; Ziel, H.L.

2005-01-01

Information on population connectivity throughout the annual cycle has become more crucial, because populations of many migratory birds are in decline. One such species is the American Woodcock (Scolopax minor), which inhabits early-successional forests in eastern North America. Although band recoveries have proved useful for dividing populations of this game bird species into an Eastern Region and Central Region for management purposes, these data do not provide enough detail to determine the breeding population of origin of birds recovered on stopover and wintering areas. To obtain more fine-scale data, we undertook a phylogeographic study of American Woodcock populations throughout their primary breeding range in the eastern United States and Canada using mitochondrial DNA (mtDNA) sequences from the hypervariable control region I (CRI) and ND6 gene. Despite high haplotype diversity, nucleotide diversity was low and there was no phylogeographic structure among American Woodcock populations across the species range, with birds from many states and provinces in both management regions sharing identical haplotypes. Results suggest recent or ongoing gene flow among populations, with asymmetric movement of birds between migration flyways. As has been demonstrated for several other avian species in North America, American Woodcock appear to have undergone a rapid population expansion following the late Pleistocene glacial retreat. Thus, a combination of historical demographic factors and recent or ongoing gene flow mask any population structure based on mtDNA that might accrue from philopatry to breeding areas observed in studies of marked birds.

Problem Based Learning in Cooperative Situation (PBLCS) and Its Impact on Development of Personal Intelligence

ERIC Educational Resources Information Center

Talib, Ahmad; Bini Kailani, Ismail

2014-01-01

The objective of this study was focused on the observation on the practice of PBLCS learning model, and its impact on the development of personal intelligence (interpersonal and intrapersonal) students. This study used a quasi-experimental design with one factor measurement. The study population was students of class XI, IPA (Natural Science) SMAN…

Estimating population size of Pygoscelid Penguins from TM data

NASA Technical Reports Server (NTRS)

Olson, Charles E., Jr.; Schwaller, Mathew R.; Dahmer, Paul A.

1987-01-01

An estimate was made toward a continent wide population of penguins. The results indicate that Thematic Mapper data can be used to identify penguin rookeries due to the unique reflectance properties of guano. Strong correlations exist between nesting populations and rookery area occupied by the birds. These correlations allow estimation of the number of nesting pairs in colonies. The success of remote sensing and biometric analyses leads one to believe that a continent wide estimate of penguin populations is possible based on a timely sample employing ground based and remote sensing techniques. Satellite remote sensing along the coastline may well locate previously undiscovered penguin nesting sites, or locate rookeries which have been assumed to exist for over a half century, but never located. Observations which found that penguins are one of the most sensitive elements in the complex of Southern Ocean ecosystems motivated this study.

Male circumcision and HIV infection risk.

PubMed

Krieger, John N

2012-02-01

Male circumcision is being promoted to reduce human immunodeficiency virus type 1 (HIV) infection rates. This review evaluates the scientific evidence suggesting that male circumcision reduces HIV infection risk in high-risk heterosexual populations. We followed the updated International Consultation on Urological Diseases evidence-based medicine recommendations to critically review the scientific evidence on male circumcision and HIV infection risk. Level 1 evidence supports the concept that male circumcision substantially reduces the risk of HIV infection. Three major lines of evidence support this conclusion: biological data suggesting that this concept is plausible, data from observational studies supported by high-quality meta-analyses, and three randomized clinical trials supported by high-quality meta-analyses. The evidence from these biological studies, observational studies, randomized controlled clinical trials, meta-analyses, and cost-effectiveness studies is conclusive. The challenges to implementation of male circumcision as a public health measure in high-risk populations must now be faced.

Is higher sodium intake associated with elevated systemic inflammation? A population-based study.

PubMed

Fogarty, Andrew W; Lewis, Sarah A; McKeever, Tricia M; Britton, John R

2009-06-01

Observational epidemiologic studies have suggested that a low-sodium diet is associated with reduced mortality. The objective was to test the hypothesis that a higher dietary intake of sodium is associated with increased systemic inflammation--a potential risk factor for both cardiovascular disease and cancer. The study design consisted of a randomly selected, cross-sectional, population-based study of 2633 individuals surveyed in 1991, of whom 1597 participants provided paired urinary and blood samples permitting measurement of 24-h urinary sodium excretion and serum C-reactive protein (CRP) concentrations. The mean (+/-SD) 24-h sodium intake for the population was 177 +/- 69 mmol. In the basic model adjusted for age, sex, and smoking, higher levels of 24-h sodium excretion were directly associated with serum CRP, with an increase in serum CRP of 1.20 mg/L per 100-mmol increment in sodium excretion (95% CI: 1.11, 1.30). However, this association was reduced after adjustment for body mass index, with an increase in serum CRP of 1.06 mg/L per 100-mmol increment in sodium excretion (95% CI: -1.02, 1.15). We observed a linear association between an objective measure of sodium intake and serum CRP that may be influenced by confounding by body mass index. The magnitude of these associations suggests that dietary sodium consumption is unlikely to be an important modifiable risk factor for increased systemic inflammation.

Usage of purchased self-tests for HIV and sexually transmitted infections in Amsterdam, the Netherlands: results of population-based and serial cross-sectional studies among the general population and sexual risk groups.

PubMed

Bil, Janneke P; Prins, Maria; Stolte, Ineke G; Dijkshoorn, Henriëtte; Heijman, Titia; Snijder, Marieke B; Davidovich, Udi; Zuure, Freke R

2017-09-21

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. Data were collected in four different studies among the general population (S1 - 2) and sexual risk groups (S3 - 4). 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). Prevalence of HIV/STI self-test usage and its determinants. 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. 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. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Cardiopulmonary resuscitation of out-of-hospital traumatic cardiac arrest in Qatar: A nationwide population-based study.

PubMed

Irfan, Furqan B; Consunji, Rafael; El-Menyar, Ayman; George, Pooja; Peralta, Ruben; Al-Thani, Hassan; Thomas, Stephen Hodges; Alinier, Guillaume; Shuaib, Ashfaq; Al-Suwaidi, Jassim; Singh, Rajvir; Castren, Maaret; Cameron, Peter A; Djarv, Therese

2017-08-01

Traumatic cardiac arrest studies have reported improved survival rates recently, ranging from 1.7-7.5%. This population-based nationwide study aims to describe the epidemiology, interventions and outcomes, and determine predictors of survival from out-of-hospital traumatic cardiac arrest (OHTCA) in Qatar. An observational retrospective population-based study was conducted on OHTCA patients in Qatar, from January 2010 to December 2015. Traumatic cardiac arrest was redefined to include out-of-hospital traumatic cardiac arrest (OHTCA) and in-hospital traumatic cardiac arrest (IHTCA). A total of 410 OHTCA patients were included in the 6-year study period. The mean annual crude incidence rate of OHTCA was 4.0 per 100,000 population, in Qatar. OHTCA mostly occurred in males with a median age of 33. There was a preponderance of blunt injuries (94.3%) and head injuries (66.3%). Overall, the survival rate was 2.4%. Shockable rhythm, prehospital external hemorrhage control, in-hospital blood transfusion, and surgery were associated with higher odds of survival. Adrenaline (Epinephrine) lowered the odds of survival. The incidence of OHTCA was less than expected, with a low rate of survival. Thoracotomy was not associated with improved survival while Adrenaline administration lowered survival in OHTCA patients with majority blunt injuries. Interventions to enable early prehospital control of hemorrhage, blood transfusion, thoracostomy and surgery improved survival. Copyright © 2017 Elsevier B.V. All rights reserved.

Hypertension in Germany.

PubMed

Neuhauser, Hannelore; Diederichs, Claudia; Boeing, Heiner; Felix, Stephan B; Jünger, Claus; Lorbeer, Roberto; Meisinger, Christine; Peters, Annette; Völzke, Henry; Weikert, Cornelia; Wild, Philipp; Dörr, Marcus

2016-12-02

Hypertension is a key risk factor. However, population data based on blood pressure measurements in Germany are scarce. Standardized blood pressure (BP) measurements and medication data from seven population-based studies conducted in Germany between 1994 and 2012 (66 845 participants, 25-74 years) were analyzed: the EPICPotsdam study (1994-1998, EPIC), the KORA-S4 Study (1999-2001) in Augsburg, and the Gutenberg Health Study (2007-2012, GHS) in Mainz/Mainz-Bingen provided data for descriptive comparisons. Time trends were analyzed based on identical study regions for the German National Health Interview and Examination Survey 1998 (BGS98) and the German Health Examination Survey for Adults (2008-11, DEGS1) as well as the Study of Health in Pomerania (SHIP) in Northeast Germany (1997-2001) and the SHIP-TREND study (2008-2012). BP data were adjusted for study-specific measurement devices based on calibration studies. After adjustment for study-specific measurement devices, mean systolic and diastolic BP values were lower and treatment proportions higher in recent (2007-2012) compared to older (1994-2001) studies. Mean BP decrease was most pronounced (systolic ≥ 10 mmHg) in the elderly (55-74 years). The regional SHIP-TREND data for Northeast Germany showed a decrease in mean systolic BP in young men aged 25 to 34 years; on a national level according to the DEGS1 data, however, no such decrease was observed for this group. New data add evidence for lower BP in Germany. However, the prevention potential remains high. Future research based on population-based data should place a special focus on blood pressure data in young men.

Genotype-Based Association Mapping of Complex Diseases: Gene-Environment Interactions with Multiple Genetic Markers and Measurement Error in Environmental Exposures

PubMed Central

Lobach, Irvna; Fan, Ruzone; Carroll, Raymond T.

2011-01-01

With the advent of dense single nucleotide polymorphism genotyping, population-based association studies have become the major tools for identifying human disease genes and for fine gene mapping of complex traits. We develop a genotype-based approach for association analysis of case-control studies of gene-environment interactions in the case when environmental factors are measured with error and genotype data are available on multiple genetic markers. To directly use the observed genotype data, we propose two genotype-based models: genotype effect and additive effect models. Our approach offers several advantages. First, the proposed risk functions can directly incorporate the observed genotype data while modeling the linkage disequihbrium information in the regression coefficients, thus eliminating the need to infer haplotype phase. Compared with the haplotype-based approach, an estimating procedure based on the proposed methods can be much simpler and significantly faster. In addition, there is no potential risk due to haplotype phase estimation. Further, by fitting the proposed models, it is possible to analyze the risk alleles/variants of complex diseases, including their dominant or additive effects. To model measurement error, we adopt the pseudo-likelihood method by Lobach et al. [2008]. Performance of the proposed method is examined using simulation experiments. An application of our method is illustrated using a population-based case-control study of association between calcium intake with the risk of colorectal adenoma development. PMID:21031455

Seroprevalence of Helicobacter pylori in Hispanics living in Puerto Rico: A population-based study.

PubMed

González-Pons, María; Soto-Salgado, Marievelisse; Sevilla, Javier; Márquez-Lespier, Juan M; Morgan, Douglas; Pérez, Cynthia M; Cruz-Correa, Marcia

2018-02-01

Helicobacter pylori is an important etiologic factor for peptic ulcers and gastric cancer, one of the top ten leading causes of cancer death in Puerto Rico. However, the prevalence of H. pylori infections in this population was previously unknown. The aim of this study was to examine the seroprevalence of H. pylori and its associated risk factors in Puerto Rico. A cross-sectional study was designed using an existing population-based biorepository. Seropositivity was determined using the Premier ™ H. pylori immunoassay. Helicobacter pylori seroprevalence was estimated with 95% confidence using marginal standardization following logistic regression. To assess the risk factors associated with H. pylori seropositivity, a multivariable log-binomial model was fitted to estimate the prevalence ratio (PR) and its 95% confidence interval (95% CI). A total of 528 population-based serum samples were analyzed. The mean age of the study population was 41 ± 12 years, of whom 55.3% were females. The overall seroprevalence of H. pylori was 33.0% (95% CI = 28.3%-38.1%). Increasing age and having <12 years of education were significantly (P < .05) associated with H. pylori seropositivity in the multivariable model; however, residing in counties with low population density reached marginal significance (P = .085). We report that H. pylori infection is common among Hispanics living in Puerto Rico. The H. pylori seroprevalence observed in Puerto Rico is similar to the seroprevalence reported in the overall population of the United States. The association between H. pylori seroprevalence and the risk factors analyzed offers insight into the epidemiology of gastric cancer in Puerto Rico and warrants further investigation. © 2017 The Authors. Helicobacter Published by John Wiley & Sons Ltd.

High coffee consumption and different brewing methods in relation to postmenopausal endometrial cancer risk in the Norwegian Women and Cancer Study: a population-based prospective study

PubMed Central

2014-01-01

Background Coffee and its compounds have been proposed to inhibit endometrial carcinogenesis. Studies in the Norwegian population can be especially interesting due to the high coffee consumption and increasing incidence of endometrial cancer in the country. Methods A total of 97 926 postmenopausal Norwegian women from the population-based prospective Norwegian Women and Cancer (NOWAC) Study, were included in the present analysis. We evaluated the general association between total coffee consumption and endometrial cancer risk as well as the possible impact of brewing method. Multivariate Cox regression analysis was used to estimate risks, and heterogeneity tests were performed to compare brewing methods. Results During an average of 10.9 years of follow-up, 462 incident endometrial cancer cases were identified. After multivariate adjustment, significant risk reduction was found among participants who drank ≥8 cups/day of coffee with a hazard ratio of 0.52 (95% confidence interval, CI 0.34-0.79). However, we did not observe a significant dose-response relationship. No significant heterogeneity in risk was found when comparing filtered and boiled coffee brewing methods. A reduction in endometrial cancer risk was observed in subgroup analyses among participants who drank ≥8 cups/day and had a body mass index ≥25 kg/m2, and in current smokers. Conclusions These data suggest that in this population with high coffee consumption, endometrial cancer risk decreases in women consuming ≥8 cups/day, independent of brewing method. PMID:24666820

Male reproductive system parameters in a two-generation reproduction study of ammonium perfluorooctanoate in rats and human relevance.

PubMed

York, Raymond G; Kennedy, Gerald L; Olsen, Geary W; Butenhoff, John L

2010-04-30

Ammonium perfluorooctanoate (ammonium PFOA) is an industrial surfactant that has been used primarily as a processing aid in the manufacture of fluoropolymers. The environmental and metabolic stability of PFOA together with its presence in human blood and long elimination half-life have led to extensive toxicological studies in laboratory animals. Two recent publications based on observations from the Danish general population have reported: (1) a negative association between serum concentrations of PFOA in young adult males and their sperm counts and (2) a positive association among women with time to pregnancy. A two-generation reproduction study in rats was previously published (2004) in which no effects on functional reproduction were observed at doses up to 30mg ammonium PFOA/kg body weight. The article contained the simple statement: "In males, fertility was normal as were all sperm parameters". In order to place the recent human epidemiological data in perspective, herein we provide the detailed male reproductive parameters from that study, including sperm quality and testicular histopathology. Sperm parameters in rats from the two-generation study in all ammonium PFOA treatment groups were unaffected by treatment with ammonium PFOA. These observations reflected the normal fertility observations in these males. No evidence of altered testicular and sperm structure and function was observed in ammonium PFOA-treated rats whose mean group serum PFOA concentrations ranged up to approximately 50,000ng/mL. Given that median serum PFOA in the Danish cohorts was approximately 5ng/mL, it seems unlikely that concentrations observed in the general population, including those recently reported in Danish general population, could be associated causally with a real decrement in sperm number and quality.

Attitudes towards the Euro: An Empirical Study Based on the German Socio-Economic Panel (SOEP)

ERIC Educational Resources Information Center

Isengard, Bettina; Schneider, Thorsten

2007-01-01

This paper investigates changing attitudes towards the euro over time in Germany using longitudinal micro-data from the German Socio Economic Panel Study. We observe that a large part of the German population was worried about the new currency both before and after its introduction. Social psychological theories provide insight into these…

Community duplicate diet methodology: A new tool for estimating dietary exposure to pesticides

EPA Science Inventory

An observational field study was conducted to assess the feasibility of a community duplicate diet collection method; a dietary monitoring procedure that is population-based. The purpose was to establish an alternative procedure to duplicate diet sampling that would be more effi...

Life-history and habitat features influence the within-river genetic structure of Atlantic salmon.

PubMed

Vähä, Juha-Pekka; Erkinaro, Jaakko; Niemelä, Eero; Primmer, Craig R

2007-07-01

Defining populations and identifying ecological and life-history characteristics affecting genetic structure is important for understanding species biology and hence, for managing threatened or endangered species or populations. In this study, populations of the world's largest indigenous Atlantic salmon (Salmo salar) stock were first inferred using model-based clustering methods, following which life-history and habitat variables best predicting the genetic diversity of populations were identified. This study revealed that natal homing of Atlantic salmon within the Teno River system is accurate at least to the tributary level. Generally, defining populations by main tributaries was observed to be a reasonable approach in this large river system, whereas in the mainstem of the river, the number of inferred populations was fewer than the number of distinct sampling sites. Mainstem and headwater populations were genetically more diverse and less diverged, while each tributary fostered a distinct population with high genetic differentiation and lower genetic diversity. Population structure and variation in genetic diversity among populations were poorly explained by geographical distance. In contrast, age-structure, as estimated by the proportion of multisea-winter spawners, was the most predictive variable in explaining the variation in the genetic diversity of the populations. This observation, being in agreement with theoretical predictions, emphasizes the essence of large multisea-winter females in maintaining the genetic diversity of populations. In addition, the unique genetic diversity of populations, as estimated by private allele richness, was affected by the ease of accessibility of a site, with more difficult to access sites having lower unique genetic diversity. Our results show that despite this species' high capacity for migration, tributaries foster relatively closed populations with little gene flow which will be important to consider when developing management strategies for the system.

Using multiple data types and integrated population models to improve our knowledge of apex predator population dynamics.

PubMed

Bled, Florent; Belant, Jerrold L; Van Daele, Lawrence J; Svoboda, Nathan; Gustine, David; Hilderbrand, Grant; Barnes, Victor G

2017-11-01

Current management of large carnivores is informed using a variety of parameters, methods, and metrics; however, these data are typically considered independently. Sharing information among data types based on the underlying ecological, and recognizing observation biases, can improve estimation of individual and global parameters. We present a general integrated population model (IPM), specifically designed for brown bears ( Ursus arctos ), using three common data types for bear ( U . spp.) populations: repeated counts, capture-mark-recapture, and litter size. We considered factors affecting ecological and observation processes for these data. We assessed the practicality of this approach on a simulated population and compared estimates from our model to values used for simulation and results from count data only. We then present a practical application of this general approach adapted to the constraints of a case study using historical data available for brown bears on Kodiak Island, Alaska, USA. The IPM provided more accurate and precise estimates than models accounting for repeated count data only, with credible intervals including the true population 94% and 5% of the time, respectively. For the Kodiak population, we estimated annual average litter size (within one year after birth) to vary between 0.45 [95% credible interval: 0.43; 0.55] and 1.59 [1.55; 1.82]. We detected a positive relationship between salmon availability and adult survival, with survival probabilities greater for females than males. Survival probabilities increased from cubs to yearlings to dependent young ≥2 years old and decreased with litter size. Linking multiple information sources based on ecological and observation mechanisms can provide more accurate and precise estimates, to better inform management. IPMs can also reduce data collection efforts by sharing information among agencies and management units. Our approach responds to an increasing need in bear populations' management and can be readily adapted to other large carnivores.

Population genomics of the inbred Scandinavian wolf.

PubMed

Hagenblad, Jenny; Olsson, Maria; Parker, Heidi G; Ostrander, Elaine A; Ellegren, Hans

2009-04-01

The Scandinavian wolf population represents one of the genetically most well-characterized examples of a severely bottlenecked natural population (with only two founders), and of how the addition of new genetic material (one immigrant) can at least temporarily provide a 'genetic rescue'. However, inbreeding depression has been observed in this population and in the absence of additional immigrants, its long-term viability is questioned. To study the effects of inbreeding and selection on genomic diversity, we performed a genomic scan with approximately 250 microsatellite markers distributed across all autosomes and the X chromosome. We found linkage disequilibrium (LD) that extended up to distances of 50 Mb, exceeding that of most outbreeding species studied thus far. LD was particularly pronounced on the X chromosome. Overall levels of observed genomic heterozygosity did not deviate significantly from simulations based on known population history, giving no support for a general selection for heterozygotes. However, we found evidence supporting balancing selection at a number of loci and also evidence suggesting directional selection at other loci. For markers on chromosome 23, the signal of selection was particularly strong, indicating that purifying selection against deleterious alleles may have occurred even in this very small population. These data suggest that population genomics allows the exploration of the effects of neutral and non-neutral evolution on a finer scale than what has previously been possible.

Nationwide population-based study of cause-specific death rates in patients with psoriasis.

PubMed

Salahadeen, E; Torp-Pedersen, C; Gislason, G; Hansen, P R; Ahlehoff, O

2015-05-01

Psoriasis is a common chronic disease, mediated by type 1 and 17 helper T cell-driven inflammation. Epidemiological studies have demonstrated a wide range of comorbidities and increased mortality rates. However, the current evidence on psoriasis-related mortality is limited and nationwide data have not been presented previously. In a nationwide population-based cohort we evaluated all-cause and cause-specific death rates in patients with psoriasis as compared to the general population. The entire Danish population aged 18 and above, corresponding to a total of 5,458,627 individuals (50.7% female, 40.9 years ± 19.7), including 94,069 with mild psoriasis (53% female, 42.0 ± 17.0 years) and 28,253 with severe psoriasis (53.4% female, 43.0 ± 16.5 years), was included. A total of 884,661 deaths were recorded, including 10 916 in patients with mild psoriasis and 3699 in patients with severe psoriasis. The age at time of death varied by psoriasis status, i.e. 76.5 ± 14.0, 74.4 ± 12.8 and 72.0 ± 13.4 years, for the general population, mild psoriasis and severe psoriasis respectively. In general, the highest death rates were observed in patients with severe psoriasis. Overall death rates per 1000 patient years were 13.8 [confidence interval (CI) 13.8-13.8], 17.0 (CI 16.7-17.3) and 25.4 (CI 24.6-26.3) for the general population, patients with mild psoriasis and patients with severe psoriasis respectively. This nationwide population-based study of cause-specific death rates in patients with psoriasis demonstrated reduced lifespan and increased rates of all examined specific causes of death in patients with psoriasis compared to the general population. © 2014 European Academy of Dermatology and Venereology.

Long-term effective population size dynamics of an intensively monitored vertebrate population

PubMed Central

Mueller, A-K; Chakarov, N; Krüger, O; Hoffman, J I

2016-01-01

Long-term genetic data from intensively monitored natural populations are important for understanding how effective population sizes (Ne) can vary over time. We therefore genotyped 1622 common buzzard (Buteo buteo) chicks sampled over 12 consecutive years (2002–2013 inclusive) at 15 microsatellite loci. This data set allowed us to both compare single-sample with temporal approaches and explore temporal patterns in the effective number of parents that produced each cohort in relation to the observed population dynamics. We found reasonable consistency between linkage disequilibrium-based single-sample and temporal estimators, particularly during the latter half of the study, but no clear relationship between annual Ne estimates () and census sizes. We also documented a 14-fold increase in between 2008 and 2011, a period during which the census size doubled, probably reflecting a combination of higher adult survival and immigration from further afield. Our study thus reveals appreciable temporal heterogeneity in the effective population size of a natural vertebrate population, confirms the need for long-term studies and cautions against drawing conclusions from a single sample. PMID:27553455

Conservation Genetics of Threatened Hippocampus guttulatus in Vulnerable Habitats in NW Spain: Temporal and Spatial Stability of Wild Populations with Flexible Polygamous Mating System in Captivity

PubMed Central

López, Almudena; Vera, Manuel; Planas, Miquel; Bouza, Carmen

2015-01-01

This study was focused on conservation genetics of threatened Hippocampus guttulatus on the Atlantic coast of NW Iberian Peninsula. Information about spatial structure and temporal stability of wild populations was obtained based on microsatellite markers, and used for monitoring a captive breeding program firstly initiated in this zone at the facilities of the Institute of Marine Research (Vigo, Spain). No significant major genetic structure was observed regarding the biogeographical barrier of Cape Finisterre. However, two management units under continuous gene flow are proposed based on the allelic differentiation between South-Atlantic and Cantabrian subpopulations, with small to moderate contemporary effective size based on single-sample methods. Temporal stability was observed in South-Atlantic population samples of H. guttulatus for the six-year period studied, suggesting large enough effective population size to buffer the effects of genetic drift within the time frame of three generations. Genetic analysis of wild breeders and offspring in captivity since 2009 allowed us to monitor the breeding program founded in 2006 in NW Spain for this species. Similar genetic diversity in the renewed and founder broodstock, regarding the wild population of origin, supports suitable renewal and rearing processes to maintain genetic variation in captivity. Genetic parentage proved single-brood monogamy in the wild and in captivity, but flexible short- and long-term mating system under captive conditions, from strict monogamy to polygamy within and/or among breeding seasons. Family analysis showed high reproductive success in captivity under genetic management assisted by molecular relatedness estimates to avoid inbreeding. This study provides genetic information about H. guttulatus in the wild and captivity within an uncovered geographical range for this data deficient species, to be taken into account for management and conservation purposes. PMID:25646777

Utilisation of prehospital emergency medical services for hyperglycaemia: A community-based observational study.

PubMed

Villani, Melanie; Nanayakkara, Natalie; Ranasinha, Sanjeeva; Earnest, Arul; Smith, Karen; Soldatos, Georgia; Teede, Helena; Zoungas, Sophia

2017-01-01

This study examines prehospital Emergency Medical Service (EMS) utilisation and patterns of demand for hyperglycaemia management, including characteristics of individuals and factors related to hospital transport. A state-wide, community-based observational study of all patients requiring prehospital EMS for hyperglycaemia during a 7 year study period (Jan 2009-Dec 2015) using electronic data from the Ambulance Victoria data warehouse was conducted. Pre-specified variables related to patient demographics, comorbidities, examination findings, paramedic treatment and transport outcomes were obtained. Logistic regression was used to assess factors associated with transport to hospital. There were 11,417 cases of hyperglycaemia attended by paramedics during the study period, accounting for 0.3-0.4% of the total annual EMS caseload, and equating to 0.54 attendances per 100 people with diabetes in the state of Victoria, Australia, per year. There was a significant increase in annual utilisation, with a rate ratio of 1.62 between 2009 (2.42 cases per 10,000 population) and 2015 (3.91 cases per 10,000 population). Fifty-one percent of cases had type 2 diabetes, 37% had type 1 diabetes, 4% had diabetes with the type unspecified and 8% had no recorded history of diabetes. Ninety percent of cases were transported to hospital. Factors associated with increased odds of transport to hospital included no known history of diabetes, regional/rural locations, case time between 0600 and <1800 hours, increasing number of comorbidities and increasingly unstable vital sign observations. There is substantial utilisation of prehospital EMS for hyperglycaemia. With increased population prevalence of diabetes predicted, further research on opportunities for prevention, as well as optimal management in the prehospital environment is warranted.

Development of microsatellite markers for Dimorphandra mollis (Leguminosae), a widespread tree from the Brazilian cerrado.

PubMed

Souza, Helena A V; Collevatti, Rosane G; Lemos-Filho, José P; Santos, Fabrício R; Lovato, Maria Bernadete

2012-03-01

Microsatellite markers were developed for Dimorphandra mollis (Leguminosae), a widespread tree in the Brazilian cerrado (a savanna-like vegetation). Microsatellite markers were developed from an enriched library. The analyses of polymorphism were based on 56 individuals from three populations. Nine microsatellite loci were polymorphic, with the number of alleles per locus ranging from three to 10 across populations. The observed and expected heterozygosities per locus and population ranged from 0.062 to 0.850 and from 0.062 to 0.832, respectively. These microsatellites provide an efficient tool for population genetics studies and will be used to assess the genetic diversity and spatial genetic structure of D. mollis.

Mobile phone use and glioma risk: comparison of epidemiological study results with incidence trends in the United States

PubMed Central

Rajaraman, P; Curtis, R E; Devesa, S S; Inskip, P D; Check, D P; Linet, M S

2012-01-01

Objective In view of mobile phone exposure being classified as a possible human carcinogen by the International Agency for Research on Cancer (IARC), we determined the compatibility of two recent reports of glioma risk (forming the basis of the IARC’s classification) with observed incidence trends in the United States. Design Comparison of observed rates with projected rates of glioma incidence for 1997-2008. We estimated projected rates by combining relative risks reported in the 2010 Interphone study and a 2011 Swedish study by Hardell and colleagues with rates adjusted for age, registry, and sex; data for mobile phone use; and various latency periods. Setting US population based data for glioma incidence in 1992-2008, from 12 registries in the Surveillance, Epidemiology, and End Results (SEER) programme (Atlanta, Detroit, Los Angeles, San Francisco, San Jose-Monterey, Seattle, rural Georgia, Connecticut, Hawaii, Iowa, New Mexico, and Utah). Participants Data for 24 813 non-Hispanic white people diagnosed with glioma at age 18 years or older. Results Age specific incidence rates of glioma remained generally constant in 1992-2008 (−0.02% change per year, 95% confidence interval −0.28% to 0.25%), a period coinciding with a substantial increase in mobile phone use from close to 0% to almost 100% of the US population. If phone use was associated with glioma risk, we expected glioma incidence rates to be higher than those observed, even with a latency period of 10 years and low relative risks (1.5). Based on relative risks of glioma by tumour latency and cumulative hours of phone use in the Swedish study, predicted rates should have been at least 40% higher than observed rates in 2008. However, predicted glioma rates based on the small proportion of highly exposed people in the Interphone study could be consistent with the observed data. Results remained valid if we used either non-regular users or low users of mobile phones as the baseline category, and if we constrained relative risks to be more than 1. Conclusions Raised risks of glioma with mobile phone use, as reported by one (Swedish) study forming the basis of the IARC’s re-evaluation of mobile phone exposure, are not consistent with observed incidence trends in US population data, although the US data could be consistent with the modest excess risks in the Interphone study. PMID:22403263

Clinically observed chickenpox and the risk of childhood-onset multiple sclerosis.

PubMed

Mikaeloff, Yann; Caridade, Guillaume; Suissa, Samy; Tardieu, Marc

2009-05-15

The authors conducted a population-based case-control study to investigate whether clinically observed chickenpox, linked with a level of intensity for clinical expression, increases the risk of multiple sclerosis (MS) in childhood. The cases were MS patients whose disease onset occurred between 1994 and 2003, before age 16 years, in France. Each case was matched for age, sex, and geographic origin with as many as 12 controls randomly selected from the general population. Information about clinically observed chickenpox in cases and controls before the index date regarding onset of MS was collected with a standardized questionnaire and was checked against health certificates. Conditional logistic regression was used to estimate the odds ratio for an association between MS and chickenpox. The 137 MS cases were matched with 1,061 controls. Clinically observed chickenpox had occurred in 76.6% of the cases and 84.9% of their matched controls. The adjusted odds ratio of MS onset associated with chickenpox occurrence was 0.58 (95% confidence interval: 0.36, 0.92). The authors concluded that clinically observed chickenpox was associated with a lower risk of childhood-onset MS in a French population.

Counting the stunted children in a population: a criticism of old and new approaches and a conciliatory proposal.

PubMed

Monteiro, C A

1991-01-01

Two methods for estimating the prevalence of growth retardation in a population are evaluated: the classical method, which is based on the proportion of children whose height is more than 2 standard deviations below the expected mean of a reference population; and a new method recently proposed by Mora, which is based on the whole height distribution of observed and reference populations. Application of the classical method to several simulated populations leads to the conclusion that in most situations in developing countries the prevalence of growth retardation is grossly underestimated, and reflects only the presence of severe growth deficits. A second constraint with this method is a marked reduction of the relative differentials between more and less exposed strata. Application of Mora's method to the same simulated populations reduced but did not eliminate these constraints. A novel method for estimating the prevalence of growth retardation, which is based also on the whole height distribution of observed and reference populations, is also described and evaluated. This method produces better estimates of the true prevalence of growth retardation with no reduction in relative differentials.

Clinical implementation of a knowledge based planning tool for prostate VMAT.

PubMed

Powis, Richard; Bird, Andrew; Brennan, Matthew; Hinks, Susan; Newman, Hannah; Reed, Katie; Sage, John; Webster, Gareth

2017-05-08

A knowledge based planning tool has been developed and implemented for prostate VMAT radiotherapy plans providing a target average rectum dose value based on previously achievable values for similar rectum/PTV overlap. The purpose of this planning tool is to highlight sub-optimal clinical plans and to improve plan quality and consistency. A historical cohort of 97 VMAT prostate plans was interrogated using a RayStation script and used to develop a local model for predicting optimum average rectum dose based on individual anatomy. A preliminary validation study was performed whereby historical plans identified as "optimal" and "sub-optimal" by the local model were replanned in a blinded study by four experienced planners and compared to the original clinical plan to assess whether any improvement in rectum dose was observed. The predictive model was then incorporated into a RayStation script and used as part of the clinical planning process. Planners were asked to use the script during planning to provide a patient specific prediction for optimum average rectum dose and to optimise the plan accordingly. Plans identified as "sub-optimal" in the validation study observed a statistically significant improvement in average rectum dose compared to the clinical plan when replanned whereas plans that were identified as "optimal" observed no improvement when replanned. This provided confidence that the local model can identify plans that were suboptimal in terms of rectal sparing. Clinical implementation of the knowledge based planning tool reduced the population-averaged mean rectum dose by 5.6Gy. There was a small but statistically significant increase in total MU and femoral head dose and a reduction in conformity index. These did not affect the clinical acceptability of the plans and no significant changes to other plan quality metrics were observed. The knowledge-based planning tool has enabled substantial reductions in population-averaged mean rectum dose for prostate VMAT patients. This suggests plans are improved when planners receive quantitative feedback on plan quality against historical data.

A Population-Based Assessment of the Agreement Between Grading of Goniophotographic Images and Gonioscopy in the Chinese-American Eye Study (CHES).

PubMed

Murakami, Yohko; Wang, Dandan; Burkemper, Bruce; Lin, Shan C; Varma, Rohit

2016-08-01

To compare grading of goniophotographic images and gonioscopy in assessing the iridocorneal angle. In a population-based, cross-sectional study, participants underwent gonioscopy and goniophotographic imaging during the same visit. The iridocorneal angle was classified as closed if the posterior trabecular meshwork could not be seen. A single masked observer graded the goniophotographic images, and each eye was classified as having angle closure based on the number of closed quadrants. Agreement between the methods was analyzed by calculating kappa (κ) and first-order agreement coefficient (AC1) statistics and comparison of area under receiver operating characteristic curves (AUC). A total of 4149 Chinese Americans (3994 eyes) were included in this study. The agreement for angle closure diagnosis between gonioscopy and EyeCam was moderate to excellent (κ = 0.60, AC1 0.90, AUC 0.76-0.80). Detection of iridocorneal angle closure based on goniophotographic imaging shows moderate to very good agreement with angle closure assessment using gonioscopy.

Parallel Evolution of Cold Tolerance within Drosophila melanogaster

PubMed Central

Braun, Dylan T.; Lack, Justin B.

2017-01-01

Drosophila melanogaster originated in tropical Africa before expanding into strikingly different temperate climates in Eurasia and beyond. Here, we find elevated cold tolerance in three distinct geographic regions: beyond the well-studied non-African case, we show that populations from the highlands of Ethiopia and South Africa have significantly increased cold tolerance as well. We observe greater cold tolerance in outbred versus inbred flies, but only in populations with higher inversion frequencies. Each cold-adapted population shows lower inversion frequencies than a closely-related warm-adapted population, suggesting that inversion frequencies may decrease with altitude in addition to latitude. Using the FST-based “Population Branch Excess” statistic (PBE), we found only limited evidence for parallel genetic differentiation at the scale of ∼4 kb windows, specifically between Ethiopian and South African cold-adapted populations. And yet, when we looked for single nucleotide polymorphisms (SNPs) with codirectional frequency change in two or three cold-adapted populations, strong genomic enrichments were observed from all comparisons. These findings could reflect an important role for selection on standing genetic variation leading to “soft sweeps”. One SNP showed sufficient codirectional frequency change in all cold-adapted populations to achieve experiment-wide significance: an intronic variant in the synaptic gene Prosap. Another codirectional outlier SNP, at senseless-2, had a strong association with our cold trait measurements, but in the opposite direction as predicted. More generally, proteins involved in neurotransmission were enriched as potential targets of parallel adaptation. The ability to study cold tolerance evolution in a parallel framework will enhance this classic study system for climate adaptation. PMID:27777283

Epidemiology of vitamin D insufficiency and deficiency in a population in a sunny country: Geospatial meta-analysis in Brazil.

PubMed

Pereira-Santos, Marcos; Santos, José Yure Gomes Dos; Carvalho, Gisele Queiroz; Santos, Djanilson Barbosa Dos; Oliveira, Ana Marlúcia

2018-02-08

Studies conducted among populations of tropical countries have reported high prevalences of vitamin D deficiency and insufficiency. Information resulting from meta-analyses on the spatial distribution of vitamin D deficiency and insufficiency in tropical countries is still rare. The aim of this review was investigated the prevalence of vitamin D deficiency and insufficiency among the Brazilian population. Observational studies were searched in eight electronically databases. Additionally, theses and dissertations and abstracts were screened. Details on study design, methods, population, mean and data on serum concentrations of vitamin D in different age groups in Brazil were extracted. Data were pooled using a random-effects model and choropleth maps were created based on the geopolitical regions of the country. 72 published paper met the inclusion criteria. The mean vitamin D concentration among the Brazilian population between 2000 and 2017 of 67.65 nmol/L (95% CI: 65.91, 69.38 nmol/L).The prevalences of vitamin D deficiency and insufficiency were 28.16% (95% CI: 23.90, 32.40) and 45.26% (95% CI: 35.82, 54.71), respectively, for the Brazilian population. The highest prevalence of deficiency were observed in the southern and southeastern regions and the highest occurrence of vitamin D insufficiency was among the populations of the southeastern and northeastern regions. Finally, there are high prevalence of inadequate vitamin D concentrations among the population, regardless of age group in Brazil. The development of vitamin D food fortification policies in needs to be cautious and carefully planned.

Application of a hybrid model to reduce bias and improve precision in population estimates for elk (Cervus elaphus) inhabiting a cold desert ecosystem

USGS Publications Warehouse

Schoenecker, Kathryn A.; Lubow, Bruce C.

2016-01-01

Accurately estimating the size of wildlife populations is critical to wildlife management and conservation of species. Raw counts or “minimum counts” are still used as a basis for wildlife management decisions. Uncorrected raw counts are not only negatively biased due to failure to account for undetected animals, but also provide no estimate of precision on which to judge the utility of counts. We applied a hybrid population estimation technique that combined sightability modeling, radio collar-based mark-resight, and simultaneous double count (double-observer) modeling to estimate the population size of elk in a high elevation desert ecosystem. Combining several models maximizes the strengths of each individual model while minimizing their singular weaknesses. We collected data with aerial helicopter surveys of the elk population in the San Luis Valley and adjacent mountains in Colorado State, USA in 2005 and 2007. We present estimates from 7 alternative analyses: 3 based on different methods for obtaining a raw count and 4 based on different statistical models to correct for sighting probability bias. The most reliable of these approaches is a hybrid double-observer sightability model (model MH), which uses detection patterns of 2 independent observers in a helicopter plus telemetry-based detections of radio collared elk groups. Data were fit to customized mark-resight models with individual sighting covariates. Error estimates were obtained by a bootstrapping procedure. The hybrid method was an improvement over commonly used alternatives, with improved precision compared to sightability modeling and reduced bias compared to double-observer modeling. The resulting population estimate corrected for multiple sources of undercount bias that, if left uncorrected, would have underestimated the true population size by as much as 22.9%. Our comparison of these alternative methods demonstrates how various components of our method contribute to improving the final estimate and demonstrates why each is necessary.

Performance of International Classification of Diseases-based injury severity measures used to predict in-hospital mortality and intensive care admission among traumatic brain-injured patients.

PubMed

Gagné, Mathieu; Moore, Lynne; Sirois, Marie-Josée; Simard, Marc; Beaudoin, Claudia; Kuimi, Brice Lionel Batomen

2017-02-01

The International Classification of Diseases (ICD) is the main classification system used for population-based traumatic brain injury (TBI) surveillance activities but does not contain direct information on injury severity. International Classification of Diseases-based injury severity measures can be empirically derived or mapped to the Abbreviated Injury Scale, but no single approach has been formally recommended for TBI. The aim of this study was to compare the accuracy of different ICD-based injury severity measures for predicting in-hospital mortality and intensive care unit (ICU) admission in TBI patients. We conducted a population-based retrospective cohort study. We identified all patients 16 years or older with a TBI diagnosis who received acute care between April 1, 2006, and March 31, 2013, from the Quebec Hospital Discharge Database. The accuracy of five ICD-based injury severity measures for predicting mortality and ICU admission was compared using measures of discrimination (area under the receiver operating characteristic curve [AUC]) and calibration (calibration plot and the Hosmer-Lemeshow goodness-of-fit statistic). Of 31,087 traumatic brain-injured patients in the study population, 9.0% died in hospital, and 34.4% were admitted to the ICU. Among ICD-based severity measures that were assessed, the multiplied derivative of ICD-based Injury Severity Score (ICISS-Multiplicative) demonstrated the best discriminative ability for predicting in-hospital mortality (AUC, 0.858; 95% confidence interval, 0.852-0.864) and ICU admissions (AUC, 0.813; 95% confidence interval, 0.808-0.818). Calibration assessments showed good agreement between observed and predicted in-hospital mortality for ICISS measures. All severity measures presented high agreement between observed and expected probabilities of ICU admission for all deciles of risk. The ICD-based injury severity measures can be used to accurately predict in-hospital mortality and ICU admission in TBI patients. The ICISS-Multiplicative generally outperformed other ICD-based injury severity measures and should be preferred to control for differences in baseline characteristics between TBI patients in surveillance activities or injury research when only ICD codes are available. Prognostic study, level III.

Long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia): survey methods, data management, and long-term population trends.

PubMed

Ojanen, Sami P; Nieminen, Marko; Meyke, Evgeniy; Pöyry, Juha; Hanski, Ilkka

2013-10-01

Long-term observational studies conducted at large (regional) spatial scales contribute to better understanding of landscape effects on population and evolutionary dynamics, including the conditions that affect long-term viability of species, but large-scale studies are expensive and logistically challenging to keep running for a long time. Here, we describe the long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) that has been conducted since 1991 in a large network of 4000 habitat patches (dry meadows) within a study area of 50 by 70 km in the Åland Islands in Finland. We explain how the landscape structure has been described, including definition, delimitation, and mapping of the habitat patches; methods of field survey, including the logistics, cost, and reliability of the survey; and data management using the EarthCape biodiversity platform. We describe the long-term metapopulation dynamics of the Glanville fritillary based on the survey. There has been no long-term change in the overall size of the metapopulation, but the level of spatial synchrony and hence the amplitude of fluctuations in year-to-year metapopulation dynamics have increased over the years, possibly due to increasing frequency of exceptional weather conditions. We discuss the added value of large-scale and long-term population studies, but also emphasize the need to integrate more targeted experimental studies in the context of long-term observational studies. For instance, in the case of the Glanville fritillary project, the long-term study has produced an opportunity to sample individuals for experiments from local populations with a known demographic history. These studies have demonstrated striking differences in dispersal rate and other life-history traits of individuals from newly established local populations (the offspring of colonizers) versus individuals from old, established local populations. The long-term observational study has stimulated the development of metapopulation models and provided an opportunity to test model predictions. This combination of empirical studies and modeling has facilitated the study of key phenomena in spatial dynamics, such as extinction threshold and extinction debt.

Long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia): survey methods, data management, and long-term population trends

PubMed Central

Ojanen, Sami P; Nieminen, Marko; Meyke, Evgeniy; Pöyry, Juha; Hanski, Ilkka

2013-01-01

Long-term observational studies conducted at large (regional) spatial scales contribute to better understanding of landscape effects on population and evolutionary dynamics, including the conditions that affect long-term viability of species, but large-scale studies are expensive and logistically challenging to keep running for a long time. Here, we describe the long-term metapopulation study of the Glanville fritillary butterfly (Melitaea cinxia) that has been conducted since 1991 in a large network of 4000 habitat patches (dry meadows) within a study area of 50 by 70 km in the Åland Islands in Finland. We explain how the landscape structure has been described, including definition, delimitation, and mapping of the habitat patches; methods of field survey, including the logistics, cost, and reliability of the survey; and data management using the EarthCape biodiversity platform. We describe the long-term metapopulation dynamics of the Glanville fritillary based on the survey. There has been no long-term change in the overall size of the metapopulation, but the level of spatial synchrony and hence the amplitude of fluctuations in year-to-year metapopulation dynamics have increased over the years, possibly due to increasing frequency of exceptional weather conditions. We discuss the added value of large-scale and long-term population studies, but also emphasize the need to integrate more targeted experimental studies in the context of long-term observational studies. For instance, in the case of the Glanville fritillary project, the long-term study has produced an opportunity to sample individuals for experiments from local populations with a known demographic history. These studies have demonstrated striking differences in dispersal rate and other life-history traits of individuals from newly established local populations (the offspring of colonizers) versus individuals from old, established local populations. The long-term observational study has stimulated the development of metapopulation models and provided an opportunity to test model predictions. This combination of empirical studies and modeling has facilitated the study of key phenomena in spatial dynamics, such as extinction threshold and extinction debt. PMID:24198935

A stochastic bioenergetics model based approach to translating large river flow and temperature in to fish population responses: The pallid sturgeon example

USGS Publications Warehouse

Wildhaber, Mark L.; Dey, Rima; Wikle, Christopher K.; Moran, Edward H.; Anderson, Christopher J.; Franz, Kristie J.

2015-01-01

In managing fish populations, especially at-risk species, realistic mathematical models are needed to help predict population response to potential management actions in the context of environmental conditions and changing climate while effectively incorporating the stochastic nature of real world conditions. We provide a key component of such a model for the endangered pallid sturgeon (Scaphirhynchus albus) in the form of an individual-based bioenergetics model influenced not only by temperature but also by flow. This component is based on modification of a known individual-based bioenergetics model through incorporation of: the observed ontogenetic shift in pallid sturgeon diet from marcroinvertebrates to fish; the energetic costs of swimming under flowing-water conditions; and stochasticity. We provide an assessment of how differences in environmental conditions could potentially alter pallid sturgeon growth estimates, using observed temperature and velocity from channelized portions of the Lower Missouri River mainstem. We do this using separate relationships between the proportion of maximum consumption and fork length and swimming cost standard error estimates for fish captured above and below the Kansas River in the Lower Missouri River. Critical to our matching observed growth in the field with predicted growth based on observed environmental conditions was a two-step shift in diet from macroinvertebrates to fish.

A Study Of Anomalous Stars and Binary Populations Within Open Clusters: Tests Of Theoretical Models

NASA Astrophysics Data System (ADS)

Geller, Aaron M.; Mathieu, Robert D.; Braden, Ella; Latham, David W.

2008-08-01

``Anomalous'' stars, such as blue stragglers and more recently sub- subgiants, have been an enduring challenge for stellar evolution theory. Recently it has become clear that in star clusters these systems are closely linked to the binary star populations. Furthermore, through advances in N-body modeling, we have come to realize that stellar dynamical processes play a central role in the formation of such anomalous stars. Indeed, these stars trace the interface between the classical fields of stellar evolution and stellar dynamics. We propose a thesis study to directly probe this interface through high-precision radial-velocity measurements of the anomalous stars and the binary populations in four open clusters. We have selected NGC 188 (7 Gyr), M67 (NGC 2682; 4 Gyr), NGC 6819 (2.4 Gyr), and M35 (NGC 2168; 150 Myr), as these span a wide range in age, are rich enough to provide statistically significant conclusions, and already have an extensive base of kinematic, spectroscopic, and photometric observations from the WIYN Open Cluster Study. Our proposed observations will define the spectroscopic hard binary populations (fraction, frequency distributions of orbital parameters, mass ratios) for orbital periods approaching the hard-soft boundary. These observations will also provide a comprehensive survey for anomalous stars, including secure establishment of their cluster membership. These data will allow us to perform the first detailed comparison to predictions from open cluster simulations of the binary populations among normal and anomalous stars, and thereby to constrain the evolutionary paths from one to the other.

A Study Of Anomalous Stars and Binary Populations Within Open Clusters: Tests Of Theoretical Models

NASA Astrophysics Data System (ADS)

Geller, Aaron M.; Mathieu, Robert D.; Gosnell, Natalie; Latham, David W.

2009-02-01

``Anomalous'' stars, such as blue stragglers and more recently sub- subgiants, have been an enduring challenge for stellar evolution theory. Recently it has become clear that in star clusters these systems are closely linked to the binary star populations. Furthermore, through advances in N-body modeling, we have come to realize that stellar dynamical processes play a central role in the formation of such anomalous stars. Indeed, these stars trace the interface between the classical fields of stellar evolution and stellar dynamics. We propose a thesis study to directly probe this interface through high-precision radial-velocity measurements of the anomalous stars and the binary populations in four open clusters. We have selected NGC 188 (7 Gyr), M67 (NGC 2682; 4 Gyr), NGC 6819 (2.4 Gyr), and M35 (NGC 2168; 150 Myr), as these span a wide range in age, are rich enough to provide statistically significant conclusions, and already have an extensive base of kinematic, spectroscopic, and photometric observations from the WIYN Open Cluster Study. Our proposed observations will define the spectroscopic hard binary populations (fraction, frequency distributions of orbital parameters, mass ratios) for orbital periods approaching the hard-soft boundary. These observations will also provide a comprehensive survey for anomalous stars, including secure establishment of their cluster membership. These data will allow us to perform the first detailed comparison to predictions from open cluster simulations of the binary populations among normal and anomalous stars, and thereby to constrain the evolutionary paths from one to the other.

A Study Of Anomalous Stars and Binary Populations Within Open Clusters: Tests Of Theoretical Models

NASA Astrophysics Data System (ADS)

Geller, Aaron M.; Mathieu, Robert D.; Braden, Ella; Latham, David W.

2008-02-01

``Anomalous'' stars, such as blue stragglers and more recently sub- subgiants, have been an enduring challenge for stellar evolution theory. Recently it has become clear that in star clusters these systems are closely linked to the binary star populations. Furthermore, through advances in N-body modeling, we have come to realize that stellar dynamical processes play a central role in the formation of such anomalous stars. Indeed, these stars trace the interface between the classical fields of stellar evolution and stellar dynamics. We propose a thesis study to directly probe this interface through high-precision radial-velocity measurements of the anomalous stars and the binary populations in four open clusters. We have selected NGC 188 (7 Gyr), M67 (NGC 2682; 4 Gyr), NGC 6819 (2.4 Gyr), and M35 (NGC 2168; 150 Myr), as these span a wide range in age, are rich enough to provide statistically significant conclusions, and already have an extensive base of kinematic, spectroscopic, and photometric observations from the WIYN Open Cluster Study. Our proposed observations will define the spectroscopic hard binary populations (fraction, frequency distributions of orbital parameters, mass ratios) for orbital periods approaching the hard-soft boundary. These observations will also provide a comprehensive survey for anomalous stars, including secure establishment of their cluster membership. These data will allow us to perform the first detailed comparison to predictions from open cluster simulations of the binary populations among normal and anomalous stars, and thereby to constrain the evolutionary paths from one to the other.

Effects of life-state on detectability in a demographic study of the terrestrial orchid Cleistes bifaria

USGS Publications Warehouse

Kery, M.; Gregg, K.B.

2003-01-01

1. Most plant demographic studies follow marked individuals in permanent plots. Plots tend to be small, so detectability is assumed to be one for every individual. However, detectability could be affected by factors such as plant traits, time, space, observer, previous detection, biotic interactions, and especially by life-state. 2. We used a double-observer survey and closed population capture-recapture modelling to estimate state-specific detectability of the orchid Cleistes bifaria in a long-term study plot of 41.2 m2. Based on AICc model selection, detectability was different for each life-state and for tagged vs. previously untagged plants. There were no differences in detectability between the two observers. 3. Detectability estimates (SE) for one-leaf vegetative, two-leaf vegetative, and flowering/fruiting states correlated with mean size of these states and were 0.76 (0.05), 0.92 (0.06), and 1 (0.00), respectively, for previously tagged plants, and 0.84 (0.08), 0.75 (0.22), and 0 (0.00), respectively, for previously untagged plants. (We had insufficient data to obtain a satisfactory estimate of previously untagged flowering plants). 4. Our estimates are for a medium-sized plant in a small and intensively surveyed plot. It is possible that detectability is even lower for larger plots and smaller plants or smaller life-states (e.g. seedlings) and that detectabilities < 1 are widespread in plant demographic studies. 5. State-dependent detectabilities are especially worrying since they will lead to a size- or state-biased sample from the study plot. Failure to incorporate detectability into demographic estimation methods introduces a bias into most estimates of population parameters such as fecundity, recruitment, mortality, and transition rates between life-states. We illustrate this by a simple example using a matrix model, where a hypothetical population was stable but, due to imperfect detection, wrongly projected to be declining at a rate of 8% per year. 6. Almost all plant demographic studies are based on models for discrete states. State and size are important predictors both for demographic rates and detectability. We suggest that even in studies based on small plots, state- or size-specific detectability should be estimated at least at some point to avoid biased inference about the dynamics of the population sampled.

Iris pigmentation and photopic visual acuity: a preliminary study.

PubMed

Short, G B

1975-11-01

Visual acuity under varying conditions of light stress was tested in four human populations. It was found that the density of iris pigmentation had no significant effect on visual acuity under conditions of bright light. While some acclimatization to local light levels was observed, significant population differences in visual acuity were obtained. A hypothesis is advanced at to the adaptive value of varying densities of pigmentation of the iris based on the known heat absorption properties of melanin granules.

Risk of fragility fracture among patients with sarcoidosis: a population-based study 1976-2013.

PubMed

Ungprasert, P; Crowson, C S; Matteson, E L

2017-06-01

Incidence of fragility fracture of a population-based cohort of 345 patients with sarcoidosis was compared with age and sex-matched comparators. The incidence of fragility fracture was higher among patients with sarcoidosis with hazard ratio (HR) of 2.18. Several chronic inflammatory disorders increase the risk of fragility fracture. However, little is known about the risk of fragility fracture in patients with sarcoidosis. This study was conducted using a previously identified population-based cohort of 345 patients with incident sarcoidosis from Olmsted County, Minnesota. Diagnosis of sarcoidosis required physician diagnosis supported by biopsy showing non-caseating granuloma, radiographic evidence of intrathoracic sarcoidosis, and compatible clinical presentations without evidence of other granulomatous diseases. Sex and age-matched subjects randomly selected from the same underlying population were used as comparators. Medical records of cases and comparators were reviewed for baseline characteristics and incident fragility fracture. Fragility fractures were observed in 34 patients with sarcoidosis, corresponding to a cumulative incidence of 5.6% at 10 years, while 18 fragility fractures were observed among comparators for a cumulative incidence of 2.4% at 10 years. The HR of fragility fractures among cases compared with comparators was 2.18 (95% confidence interval [CI], 1.23-3.88). The risk of fragility fracture by site was significantly higher among patients with sarcoidosis, and was due to a higher rate of distal forearm fracture (HR 3.58; 95% CI 1.53-8.40). Statistically non-significant increased risk was also observed in proximal femur (HR 1.66; 95% CI 0.45-6.06) and proximal humerus (HR 3.27; 95% CI 0.66-16.21). Risk of vertebral fracture was not increased (HR 1.00; 95% CI 0.32-3.11). Patients with sarcoidosis have an increased risk of fragility fracture which is primarily driven by the higher incidence of distal forearm fracture.

Characterization of Metabolically Active Bacterial Populations in Subseafloor Nankai Trough Sediments above, within, and below the Sulfate–Methane Transition Zone

PubMed Central

Mills, Heath J.; Reese, Brandi Kiel; Shepard, Alicia K.; Riedinger, Natascha; Dowd, Scot E.; Morono, Yuki; Inagaki, Fumio

2012-01-01

A remarkable number of microbial cells have been enumerated within subseafloor sediments, suggesting a biological impact on geochemical processes in the subseafloor habitat. However, the metabolically active fraction of these populations is largely uncharacterized. In this study, an RNA-based molecular approach was used to determine the diversity and community structure of metabolically active bacterial populations in the upper sedimentary formation of the Nankai Trough seismogenic zone. Samples used in this study were collected from the slope apron sediment overlying the accretionary prism at Site C0004 during the Integrated Ocean Drilling Program Expedition 316. The sediments represented microbial habitats above, within, and below the sulfate–methane transition zone (SMTZ), which was observed approximately 20 m below the seafloor (mbsf). Small subunit ribosomal RNA were extracted, quantified, amplified, and sequenced using high-throughput 454 pyrosequencing, indicating the occurrence of metabolically active bacterial populations to a depth of 57 mbsf. Transcript abundance and bacterial diversity decreased with increasing depth. The two communities below the SMTZ were similar at the phylum level, however only a 24% overlap was observed at the genus level. Active bacterial community composition was not confined to geochemically predicted redox stratification despite the deepest sample being more than 50 m below the oxic/anoxic interface. Genus-level classification suggested that the metabolically active subseafloor bacterial populations had similarities to previously cultured organisms. This allowed predictions of physiological potential, expanding understanding of the subseafloor microbial ecosystem. Unique community structures suggest very diverse active populations compared to previous DNA-based diversity estimates, providing more support for enhancing community characterizations using more advanced sequencing techniques. PMID:22485111

Implications of intercorrelation between hepatic CYP3A4-CYP2C8 enzymes for the evaluation of drug-drug interactions: a case study with repaglinide.

PubMed

Doki, Kosuke; Darwich, Adam S; Achour, Brahim; Tornio, Aleksi; Backman, Janne T; Rostami-Hodjegan, Amin

2018-05-01

Statistically significant positive correlations are reported for the abundance of hepatic drug-metabolizing enzymes. We investigate, as an example, the impact of CYP3A4-CYP2C8 intercorrelation on the predicted interindividual variabilities of clearance and drug-drug interactions (DDIs) for repaglinide using physiologically based pharmacokinetic (PBPK) modelling. PBPK modelling and simulation were employed using Simcyp Simulator (v15.1). Virtual populations were generated assuming intercorrelations between hepatic CYP3A4-CYP2C8 abundances derived from observed values in 24 human livers. A repaglinide PBPK model was used to predict PK parameters in the presence and absence of gemfibrozil in virtual populations, and the results were compared with a clinical DDI study. Coefficient of variation (CV) of oral clearance was 52.5% in the absence of intercorrelation between CYP3A4-CYP2C8 abundances, which increased to 54.2% when incorporating intercorrelation. In contrast, CV for predicted DDI (as measured by AUC ratio before and after inhibition) was reduced from 46.0% in the absence of intercorrelation between enzymes to 43.8% when incorporating intercorrelation: these CVs were associated with 5th/95th percentiles (2.48-11.29 vs. 2.49-9.69). The range of predicted DDI was larger in the absence of intercorrelation (1.55-77.06) than when incorporating intercorrelation (1.79-25.15), which was closer to clinical observations (2.6-12). The present study demonstrates via a systematic investigation that population-based PBPK modelling incorporating intercorrelation led to more consistent estimation of extreme values than those observed in interindividual variabilities of clearance and DDI. As the intercorrelations more realistically reflect enzyme abundances, virtual population studies involving PBPK and DDI should avoid using Monte Carlo assignment of enzyme abundance. © 2018 The British Pharmacological Society.

The Association between Social Jetlag, the Metabolic Syndrome, and Type 2 Diabetes Mellitus in the General Population: The New Hoorn Study.

PubMed

Koopman, Anitra D M; Rauh, Simone P; van 't Riet, Esther; Groeneveld, Lenka; van der Heijden, Amber A; Elders, Petra J; Dekker, Jacqueline M; Nijpels, Giel; Beulens, Joline W; Rutters, Femke

2017-08-01

Only a few studies have investigated the metabolic consequences of social jetlag. Therefore, we examined the association of social jetlag with the metabolic syndrome and type 2 diabetes mellitus in a population-based cohort. We used cross-sectional data from the New Hoorn Study cohort ( n = 1585, 47% men, age 60.8 ± 6 years). Social jetlag was calculated as the difference in midpoint sleep (in hours) between weekdays and weekend days. Poisson and linear regression models were used to study the associations, and age was regarded as a possible effect modifier. We adjusted for sex, employment status, education, smoking, physical activity, sleep duration, and body mass index. In the total population, we only observed an association between social jetlag and the metabolic syndrome, with prevalence ratios adjusted for sex, employment status, and educational levels of 1.64 (95% CI 1.1-2.4), for participants with >2 h social jetlag, compared with participants with <1 h social jetlag. However, we observed an interaction effect of median age (<61 years). In older participants (≥61 years), no significant associations were observed between social jetlag status, the metabolic syndrome, and diabetes or prediabetes. In the younger group (<61 years), the adjusted prevalence ratios were 1.29 (95% CI 0.9-1.9) and 2.13 (95% CI 1.3-3.4) for the metabolic syndrome and 1.39 (95% CI 1.1-1.9) and 1.75 (95% CI 1.2-2.5) for diabetes/prediabetes, for participants with 1-2 h and >2 h social jetlag, compared with participants with <1 h social jetlag. In conclusion, in our population-based cohort, social jetlag was associated with a 2-fold increased risk of the metabolic syndrome and diabetes/prediabetes, especially in younger (<61 years) participants.

Measuring spatial and temporal trends of nicotine and alcohol consumption in Australia using wastewater-based epidemiology.

PubMed

Lai, Foon Yin; Gartner, Coral; Hall, Wayne; Carter, Steve; O'Brien, Jake; Tscharke, Benjamin J; Been, Frederic; Gerber, Cobus; White, Jason; Thai, Phong; Bruno, Raimondo; Prichard, Jeremy; Kirkbride, K Paul; Mueller, Jochen F

2018-06-01

Tobacco and alcohol consumption remain priority public health issues world-wide. As participation in population-based surveys has fallen, it is increasingly challenging to estimate accurately the prevalence of alcohol and tobacco use. Wastewater-based epidemiology (WBE) is an alternative approach for estimating substance use at the population level that does not rely upon survey participation. This study examined spatio-temporal patterns in nicotine (a proxy for tobacco) and alcohol consumption in the Australian population via WBE. Daily wastewater samples (n = 164) were collected at 18 selected wastewater treatment plants across Australia, covering approximately 45% of the total population. Nicotine and alcohol metabolites in the samples were measured using liquid chromatography-tandem mass spectrometry. Daily consumption of nicotine and alcohol and its associated uncertainty were computed using Monte Carlo simulations. Nation-wide daily average and weekly consumption of these two substances were extrapolated using ordinary least squares and mixed-effect models. Nicotine and alcohol consumption was observed in all communities. Consumption of these substances in rural towns was three to four times higher than in urban communities. The spatial consumption pattern of these substances was consistent across the monitoring periods in 2014-15. Nicotine metabolites significantly reduced by 14-25% (P = 0.001-0.008) (2014-15) in some catchments. Alcohol consumption remained constant over the studied periods. Strong weekly consumption patterns were observed for alcohol but not nicotine. Nation-wide, the daily average consumption per person (aged 15-79 years) was estimated at approximately 2.5 cigarettes and 1.3-2.0 standard drinks (weekday-weekend) of alcohol. These estimates were close to the sale figure and apparent consumption, respectively. Wastewater-based epidemiology is a feasible method for objectively evaluating the geographic, temporal and weekly profiles of nicotine and alcohol consumption in different communities nationally. © 2018 Society for the Study of Addiction.

Examining the effects of air pollution composition on within region differences in PM2.5 mortality risk estimates

EPA Science Inventory

Multi-city population-based epidemiological studies have observed significant heterogeneity in both the magnitude and direction of city-specific risk estimates, but tended to focus on regional differences in PM2.5 mortality risk estimates. Interpreting differences in risk estimat...

Migration features of Ips typographus in the Tatra Mountains: using a genetic method

Treesearch

Ferenc Lakatos

2003-01-01

The genetic structure of Ips typographus populations in the Tatra Mountains was studied based on the observed differences of gene flow and migration rate. It was a highlighted question as to what extent different natural barriers influence the migration potential of the species.

LIMITATIONS ON THE USES OF MULTIMEDIA EXPOSURE MEASUREMENTS FOR MULTIPATHWAY EXPOSURE ASSESSMENT - PART I: HANDLING OBSERVATIONS BELOW DETECTION LIMITS

EPA Science Inventory

Multimedia data from two probability-based exposure studies were investigated in terms of how censoring of non-detects affected estimation of population parameters and associations. Appropriate methods for handling censored below-detection-limit (BDL) values in this context were...

Values and Context: Taiwan Principal Preparation and Practice from an American Perspective

ERIC Educational Resources Information Center

Vogel, Linda R.

2015-01-01

This qualitative study explores the preparation and practice of school leaders in Taiwan based on indepth interviews and observations with six Taiwan school directors serving geographically diverse student populations. The journey leading to school leadership and the challenges that this representative group of educational leaders face are…

Pre-Whaling Genetic Diversity and Population Ecology in Eastern Pacific Gray Whales: Insights from Ancient DNA and Stable Isotopes

PubMed Central

Alter, S. Elizabeth; Newsome, Seth D.; Palumbi, Stephen R.

2012-01-01

Commercial whaling decimated many whale populations, including the eastern Pacific gray whale, but little is known about how population dynamics or ecology differed prior to these removals. Of particular interest is the possibility of a large population decline prior to whaling, as such a decline could explain the ∼5-fold difference between genetic estimates of prior abundance and estimates based on historical records. We analyzed genetic (mitochondrial control region) and isotopic information from modern and prehistoric gray whales using serial coalescent simulations and Bayesian skyline analyses to test for a pre-whaling decline and to examine prehistoric genetic diversity, population dynamics and ecology. Simulations demonstrate that significant genetic differences observed between ancient and modern samples could be caused by a large, recent population bottleneck, roughly concurrent with commercial whaling. Stable isotopes show minimal differences between modern and ancient gray whale foraging ecology. Using rejection-based Approximate Bayesian Computation, we estimate the size of the population bottleneck at its minimum abundance and the pre-bottleneck abundance. Our results agree with previous genetic studies suggesting the historical size of the eastern gray whale population was roughly three to five times its current size. PMID:22590499

Methylenetetrahydrofolate reductase polymorphisms and susceptibility to acute lymphoblastic leukemia in a Chinese population: a meta-analysis.

PubMed

Xiao, Yi; Deng, Tao-Ran; Su, Chang-Liang; Shang, Zhen

2014-01-01

Although many epidemiologic studies have investigated the methylenetetrahydrofolate reductase (MTHFR) gene polymorphisms and their association with acute lymphoblastic leukemia (ALL), definitive conclusions cannot be drawn. To clarify the effects of MTHFR polymorphisms on the risk of ALL, a meta-analysis was performed in a Chinese population. A computerized literature search was carried out in PubMed, the Chinese Biomedicine (CBM) database, China National Knowledge Infrastructure (CNKI) platform, and the Wanfang database (Chinese) to collect relevant articles. A total of 11 articles including 1,738 ALL cases and 2,438 controls were included in this meta-analysis. Overall, a significantly decreased association was found between the MTHFR C677T polymorphism and ALL risk when all studies in Chinese populations were pooled into the meta-analysis. In subgroup analyses stratified by age, ethnicity, and source of controls, the same results were observed in children, in population-based studies, and in people with no stated ethnicity. However, a significantly increased association was also found for MTHFR C677T in hospital-based studies, and for MTHFR A1298C in people with no stated ethnicity. Our results suggest that the MTHFR C677T and A1298C polymorphisms may be potential biomarkers for ALL risk in Chinese populations, and studies with a larger sample size and wider population spectrum are required before definitive conclusions can be drawn. © 2014 S. Karger GmbH, Freiburg.

Isolation and characterization of 14 tetranucleotide microsatellite loci for the cannonball jellyfish (Stomolophus sp.) by next generation sequencing.

PubMed

Getino-Mamet, Leandro Nicolás; Valdivia-Carrillo, Tania; Gómez Daglio, Liza; García-De León, Francisco Javier

2017-04-01

The Cannonball jellyfish (Stomolophus sp.) is a species of jellyfish with high relevance in artisanal fishing. Studies of their populations do not extend beyond the morphological descriptions knowing that presents a great morphological variability. However, there are no genetic studies to determine the number of independent populations, so microsatellite markers become a suitable option. Since there are no species-specific microsatellite loci, in this paper, 14 new microsatellite loci are characterized. Microsatellite loci were isolated de novo through next generation sequencing, by two runs on Illumina MiSeq. A total of 506,771,269 base pair were obtained, from which 142,616 were microsatellite loci, and 1546 of them could design primers. We tested 14 primer pairs on 32 individuals from Bahía de La Paz, Gulf of California. We observed low genetic variation among loci (mean number of alleles per locus = 4.33, mean observed heterozygosity 0.381, mean expected heterozygosity 0.501). These loci are the first ones described for the species and will be helpful to carry out genetic diversity and population genetics studies.

Use of Atorvastatin in Lipid Disorders and Cardiovascular Disease in Chinese Patients

PubMed Central

Ye, Yi-Cong; Zhao, Xi-Liang; Zhang, Shu-Yang

2015-01-01

Objective: Statins are still underused for the prevention of cardiovascular disease (CVD) in China. Hence, we conducted a systemic review on the pharmacology, clinical efficacy, and adverse events of atorvastatin, as well as on patient adherence. Data Sources: We conducted a systemic search in PubMed with the following keywords: “atorvastatin” (Supplementary concept) or “atorvastatin” (All field) and (“China” [AD] or “China” [all field] or “Chinese” [All field]). Study Selection: Clinical or basic research articles on atorvastatin were included. Results: Atorvastatin is a reversible and competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A reductase, decreasing the de novo cholesterol synthesis. The pharmacokinetics of atorvastatin among Chinese is similar to those in Caucasians, and several gene polymorphisms have proved to be associated with the metabolism of atorvastatin in the Chinese population. Several international multiple-center randomized control trials have demonstrated the benefit of atorvastatin for primary and secondary prevention of CVD. None of them, however, included the Chinese, and current evidence in the population is still inadequate, due to the small sample size, low study quality, short study duration, and the use of surrogate endpoints instead of clinical endpoints. The overall incidence of adverse events observed with atorvastatin did not increase in the 10–80 mg dose range, and was similar to that observed with placebo and in patients treated with other statins, which makes atorvastatin well-tolerated in the Chinese population. Moreover, high patient adherence was observed in clinical studies. Conclusions: Based on the current available evidence, there is no significant difference between Chinese and non-Chinese population in term of pharmacology and clinical efficacy/safety. High-quality evidence is still needed to support the use of atorvastatin in high-risk Chinese population. PMID:25591572

Do You See What I See? Exploring the Consequences of Luminosity Limits in Black Hole-Galaxy Evolution Studies

NASA Astrophysics Data System (ADS)

Jones, Mackenzie L.; Hickox, Ryan C.; Mutch, Simon J.; Croton, Darren J.; Ptak, Andrew F.; DiPompeo, Michael A.

2017-07-01

In studies of the connection between active galactic nuclei (AGNs) and their host galaxies, there is widespread disagreement on some key aspects of the connection. These disagreements largely stem from a lack of understanding of the nature of the full underlying AGN population. Recent attempts to probe this connection utilize both observations and simulations to correct for a missed population, but presently are limited by intrinsic biases and complicated models. We take a simple simulation for galaxy evolution and add a new prescription for AGN activity to connect galaxy growth to dark matter halo properties and AGN activity to star formation. We explicitly model selection effects to produce an “observed” AGN population for comparison with observations and empirically motivated models of the local universe. This allows us to bypass the difficulties inherent in models that attempt to infer the AGN population by inverting selection effects. We investigate the impact of selecting AGNs based on thresholds in luminosity or Eddington ratio on the “observed” AGN population. By limiting our model AGN sample in luminosity, we are able to recreate the observed local AGN luminosity function and specific star formation-stellar mass distribution, and show that using an Eddington ratio threshold introduces less bias into the sample by selecting the full range of growing black holes, despite the challenge of selecting low-mass black holes. We find that selecting AGNs using these various thresholds yield samples with different AGN host galaxy properties.

A checklist approach for monitoring neotropical migrant birds: Twenty-year trends in birds of Quebec Using EPOQ

Treesearch

Andre Cyr; Jacques Larivee

1993-01-01

EPOQ (Studies of Bird Populations in Quebec) is a data base on birds of Quebec containing more than 2.2 million records of observations recorded on 158,000 checklists from 3,600 observation sites since 1950. Trends were measured for each of four subsets of EPOQ data between 1970 and 1989 (all year, spring (April-May), summer (June-July), and fall (August-October) as...

Molecular evidence of hybridization in sympatric populations of the Enantia jethys complex (Lepidoptera: Pieridae).

PubMed

Jasso-Martínez, Jovana M; Machkour-M'Rabet, Salima; Vila, Roger; Rodríguez-Arnaiz, Rosario; Castañeda-Sortibrán, América Nitxin

2018-01-01

Hybridization events are frequently demonstrated in natural butterfly populations. One interesting butterfly complex species is the Enantia jethys complex that has been studied for over a century; many debates exist regarding the species composition of this complex. Currently, three species that live sympatrically in the Gulf slope of Mexico (Enantia jethys, E. mazai, and E. albania) are recognized in this complex (based on morphological and molecular studies). Where these species live in sympatry, some cases of interspecific mating have been observed, suggesting hybridization events. Considering this, we employed a multilocus approach (analyses of mitochondrial and nuclear sequences: COI, RpS5, and Wg; and nuclear dominant markers: inter-simple sequence repeat (ISSRs) to study hybridization in sympatric populations from Veracruz, Mexico. Genetic diversity parameters were determined for all molecular markers, and species identification was assessed by different methods such as analyses of molecular variance (AMOVA), clustering, principal coordinate analysis (PCoA), gene flow, and PhiPT parameters. ISSR molecular markers were used for a more profound study of hybridization process. Although species of the Enantia jethys complex have a low dispersal capacity, we observed high genetic diversity, probably reflecting a high density of individuals locally. ISSR markers provided evidence of a contemporary hybridization process, detecting a high number of hybrids (from 17% to 53%) with significant differences in genetic diversity. Furthermore, a directional pattern of hybridization was observed from E. albania to other species. Phylogenetic study through DNA sequencing confirmed the existence of three clades corresponding to the three species previously recognized by morphological and molecular studies. This study underlines the importance of assessing hybridization in evolutionary studies, by tracing the lineage separation process that leads to the origin of new species. Our research demonstrates that hybridization processes have a high occurrence in natural populations.

The effectiveness of an integrated collaborative care model vs. a shifted outpatient collaborative care model on community functioning, residential stability, and health service use among homeless adults with mental illness: a quasi-experimental study.

PubMed

Stergiopoulos, Vicky; Schuler, Andrée; Nisenbaum, Rosane; deRuiter, Wayne; Guimond, Tim; Wasylenki, Donald; Hoch, Jeffrey S; Hwang, Stephen W; Rouleau, Katherine; Dewa, Carolyn

2015-08-28

Although a growing number of collaborative mental health care models have been developed, targeting specific populations, few studies have utilized such interventions among homeless populations. This quasi-experimental study compared the outcomes of two shelter-based collaborative mental health care models for men experiencing homelessness and mental illness: (1) an integrated multidisciplinary collaborative care (IMCC) model and (2) a less resource intensive shifted outpatient collaborative care (SOCC) model. In total 142 participants, 70 from IMCC and 72 from SOCC were enrolled and followed for 12 months. Outcome measures included community functioning, residential stability, and health service use. Multivariate regression models were used to compare study arms with respect to change in community functioning, residential stability, and health service use outcomes over time and to identify baseline demographic, clinical or homelessness variables associated with observed changes in these domains. We observed improvements in both programs over time on measures of community functioning, residential stability, hospitalizations, emergency department visits and community physician visits, with no significant differences between groups over time on these outcome measures. Our findings suggest that shelter-based collaborative mental health care models may be effective for individuals experiencing homelessness and mental illness. Future studies should seek to confirm these findings and examine the cost effectiveness of collaborative care models for this population.

Lifestyle factors among proton pump inhibitor users and nonusers: a cross-sectional study in a population-based setting.

PubMed

Hvid-Jensen, Frederik; Nielsen, Rikke B; Pedersen, Lars; Funch-Jensen, Peter; Drewes, Asbjørn Mohr; Larsen, Finn B; Thomsen, Reimar W

2013-01-01

Lifestyle factors may influence observed associations between proton pump inhibitor (PPI) usage and health outcomes. The aim of the study reported here was to examine characteristics and differences in lifestyle among PPI users and nonusers. This cross-sectional study utilized data from a 2006 population-based health survey of 21,637 persons in the Central Danish Region. All persons using prescribed PPIs were identified through linkage to a population-based prescription database. Biometric measures and prevalence of smoking, excessive alcohol consumption, diet, and physical exercise were analyzed, comparing PPI users with nonusers. Among 10,129 (46.8%) male and 11,508 (53.2%) female survey respondents, 1,356 (13.4%) males and 1,691 (14.7%) females reported ever use of PPIs. PPI users were more obese (16.7%) than nonusers (13.1%), with an age- and sex-standardized prevalence ratio (PR) of 1.3 (95% confidence interval [CI]: 1.2-1.4). The prevalence of smokers was also higher in the PPI group (26.2% vs 22.3% [PR =1.2, 95% CI: 1.1-1.3]), as was the prevalence of ex-smokers (41.0% vs 32.0% [PR =1.2, 95% CI: 1.1-1.2]). Unhealthy diet was slightly more common among PPI users than among nonusers (15.4% vs 13.0%), with a PR of 1.2 (95% CI: 1.1-1.3). Physical exercise level and alcohol consumption were similar in the two groups. Hospital-diagnosed comorbidity was observed in 35% of PPI users (a Charlson Comorbidity Index score of 1 or more) compared with only 15% among nonusers. PPI users are more obese, smoke more, and have significantly more comorbidities than PPI nonusers. These data are important when evaluating unmeasured confounding in observational studies of PPI effects.

Japanese population structure, based on SNP genotypes from 7003 individuals compared to other ethnic groups: effects on population-based association studies.

PubMed

Yamaguchi-Kabata, Yumi; Nakazono, Kazuyuki; Takahashi, Atsushi; Saito, Susumu; Hosono, Naoya; Kubo, Michiaki; Nakamura, Yusuke; Kamatani, Naoyuki

2008-10-01

Because population stratification can cause spurious associations in case-control studies, understanding the population structure is important. Here, we examined Japanese population structure by "Eigenanalysis," using the genotypes for 140,387 SNPs in 7003 Japanese individuals, along with 60 European, 60 African, and 90 East-Asian individuals, in the HapMap project. Most Japanese individuals fell into two main clusters, Hondo and Ryukyu; the Hondo cluster includes most of the individuals from the main islands in Japan, and the Ryukyu cluster includes most of the individuals from Okinawa. The SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were found in the HLA region in chromosome 6. The nonsynonymous SNPs with the greatest frequency differences between the Hondo and Ryukyu clusters were the Val/Ala polymorphism (rs3827760) in the EDAR gene, associated with hair thickness, and the Gly/Ala polymorphism (rs17822931) in the ABCC11 gene, associated with ear-wax type. Genetic differentiation was observed, even among different regions in Honshu Island, the largest island of Japan. Simulation studies showed that the inclusion of different proportions of individuals from different regions of Japan in case and control groups can lead to an inflated rate of false-positive results when the sample sizes are large.

Multilocus Patterns of Nucleotide Diversity, Linkage Disequilibrium and Demographic History of Norway Spruce [Picea abies (L.) Karst

PubMed Central

Heuertz, Myriam; De Paoli, Emanuele; Källman, Thomas; Larsson, Hanna; Jurman, Irena; Morgante, Michele; Lascoux, Martin; Gyllenstrand, Niclas

2006-01-01

DNA polymorphism at 22 loci was studied in an average of 47 Norway spruce [Picea abies (L.) Karst.] haplotypes sampled in seven populations representative of the natural range. The overall nucleotide variation was limited, being lower than that observed in most plant species so far studied. Linkage disequilibrium was also restricted and did not extend beyond a few hundred base pairs. All populations, with the exception of the Romanian population, could be divided into two main domains, a Baltico–Nordic and an Alpine one. Mean Tajima's D and Fay and Wu's H across loci were both negative, indicating the presence of an excess of both rare and high-frequency-derived variants compared to the expected frequency spectrum in a standard neutral model. Multilocus neutrality tests based on D and H led to the rejection of the standard neutral model and exponential growth in the whole population as well as in the two main domains. On the other hand, in all three cases the data are compatible with a severe bottleneck occurring some hundreds of thousands of years ago. Hence, demographic departures from equilibrium expectations and population structure will have to be accounted for when detecting selection at candidate genes and in association mapping studies, respectively. PMID:17057229

No Evidence for Synergy Between Human Papillomavirus Genotypes for the Risk of High-Grade Squamous Intraepithelial Lesions in a Large Population-Based Study

PubMed Central

Wentzensen, Nicolas; Nason, Martha; Schiffman, Mark; Dodd, Lori; Hunt, William C.; Wheeler, Cosette M.

2014-01-01

Background. Multiple human papillomavirus (HPV) genotypes may be independently or synergistically associated with risk of high-grade squamous intraepithelial lesions (HSILs). We evaluated the risk of HSIL in women concomitantly infected with multiple HPV genotypes. Methods. A population-based stratified sample of 59 664 cervical cytology specimens from women residing in New Mexico were evaluated for cytologic abnormalities and HPV genotypes. We calculated the risk of HSIL in women infected with a single HPV genotype and the risk in those infected with multiple HPV genotypes. Results. The highest risk of HSIL was observed for HPV-16 (0.036), followed by HPV-33 (0.028), HPV-58 (0.024), and HPV-18 (0.022). For most types, we observed a greater risk of HSIL in women infected with multiple carcinogenic HPV types. In contrast, the risk of HSIL was similar in women infected with HPV-16 and other types, compared with women infected with HPV-16 only. We observed an increased but plateauing risk of HSIL in women infected with multiple types, compared with those infected with a single type, with risk ratios of 1.5 (95% confidence interval [CI], 1.2–1.8), 1.7 (95% CI, 1.3–2.4), and 1.4 (95% CI, 0.83–2.5) for women infected with 2, 3, and ≥4 genotypes, respectively. Conclusions. In the largest population-based study of HPV genotypes and cytologic outcomes so far, we did not see more than additive effects of HPV types on the risk of HSIL in women infected with multiple types. PMID:24179110

Updated population metadata for United States historical climatology network stations

USGS Publications Warehouse

Owen, T.W.; Gallo, K.P.

2000-01-01

The United States Historical Climatology Network (HCN) serial temperature dataset is comprised of 1221 high-quality, long-term climate observing stations. The HCN dataset is available in several versions, one of which includes population-based temperature modifications to adjust urban temperatures for the "heat-island" effect. Unfortunately, the decennial population metadata file is not complete as missing values are present for 17.6% of the 12 210 population values associated with the 1221 individual stations during the 1900-90 interval. Retrospective grid-based populations. Within a fixed distance of an HCN station, were estimated through the use of a gridded population density dataset and historically available U.S. Census county data. The grid-based populations for the HCN stations provide values derived from a consistent methodology compared to the current HCN populations that can vary as definitions of the area associated with a city change over time. The use of grid-based populations may minimally be appropriate to augment populations for HCN climate stations that lack any population data, and are recommended when consistent and complete population data are required. The recommended urban temperature adjustments based on the HCN and grid-based methods of estimating station population can be significantly different for individual stations within the HCN dataset.

Occupational risk factors for brain cancer: a population-based case-control study in Iowa.

PubMed

Zheng, T; Cantor, K P; Zhang, Y; Keim, S; Lynch, C F

2001-04-01

A number of occupations and industries have been inconsistently associated with the risk of brain cancer. To further explore possible relationships, we conducted a population-based case-control study of brain glioma in the state of Iowa, involving 375 histologically confirmed incident cases and 2434 population-based controls. Among men, the industries and/or occupations that had a significantly increased risk for employment of more than 10 years included roofing, siding, and sheet metalworking; newspaper work; rubber and plastics products, particularly tires and inner tubes; miscellaneous manufacturing industries; wholesale trade of durable goods, grain, and field beans; cleaning and building service occupations; miscellaneous mechanics and repairers; and janitors and cleaners. Subjects who worked in plumbing, heating, and air conditioning; electrical services; gasoline service stations; and military occupations also experienced a significantly increased risk. Among women, significant excess risk was observed for occupations in agricultural services and farming, apparel and textile products, electrical and electronic equipment manufacturing, various retail sales, record-keeping, and restaurant service. Workers in industries with a potential for gasoline or motor exhaust exposures experienced a non-significant excess risk of brain glioma.

Evaluating the Impact of an Accountable Care Organization on Population Health: The Quasi-Experimental Design of the German Gesundes Kinzigtal.

PubMed

Pimperl, Alexander; Schulte, Timo; Mühlbacher, Axel; Rosenmöller, Magdalena; Busse, Reinhard; Groene, Oliver; Rodriguez, Hector P; Hildebrandt, Helmut

2017-06-01

A central goal of accountable care organizations (ACOs) is to improve the health of their accountable population. No evidence currently links ACO development to improved population health. A major challenge to establishing the evidence base for the impact of ACOs on population health is the absence of a theoretically grounded, robust, operationally feasible, and meaningful research design. The authors present an evaluation study design, provide an empirical example, and discuss considerations for generating the evidence base for ACO implementation. A quasi-experimental study design using propensity score matching in combination with small-scale exact matching is implemented. Outcome indicators based on claims data were constructed and analyzed. Population health is measured by using a range of mortality indicators: mortality ratio, age at time of death, years of potential life lost/gained, and survival time. The application is assessed using longitudinal data from Gesundes Kinzigtal, one of the leading population-based ACOs in Germany. The proposed matching approach resulted in a balanced control of observable differences between the intervention (ACO) and control groups. The mortality indicators used indicate positive results. For example, 635.6 fewer years of potential life lost (2005.8 vs. 2641.4; t-test: sig. P < 0.05*) in the ACO intervention group (n = 5411) attributable to the ACO, also after controlling for a potential (indirect) immortal time bias by excluding the first half year after enrollment from the outcome measurement. This empirical example of the impact of a German ACO on population health can be extended to the evaluation of ACOs and other integrated delivery models of care.

Ranking ecological risks of multiple chemical stressors on amphibians.

PubMed

Fedorenkova, Anastasia; Vonk, J Arie; Lenders, H J Rob; Creemers, Raymond C M; Breure, Anton M; Hendriks, A Jan

2012-06-01

Populations of amphibians have been declining worldwide since the late 1960s. Despite global concern, no studies have quantitatively assessed the major causes of this decline. In the present study, species sensitivity distributions (SSDs) were developed to analyze the sensitivity of anurans for ammonium, nitrate, heavy metals (cadmium, copper), pesticides (18 compounds), and acidification (pH) based on laboratory toxicity data. Ecological risk (ER) was calculated as the probability that a measured environmental concentration of a particular stressor in habitats where anurans were observed would exceed the toxic effect concentrations derived from the species sensitivity distributions. The assessment of ER was used to rank the stressors according to their potential risk to anurans based on a case study of Dutch freshwater bodies. The derived ERs revealed that threats to populations of anurans decreased in the sequence of pH, copper, diazinon, ammonium, and endosulfan. Other stressors studied were of minor importance. The method of deriving ER by combining field observation data and laboratory data provides insight into potential threats to species in their habitats and can be used to prioritize stressors, which is necessary to achieve effective management in amphibian conservation. Copyright © 2012 SETAC.

Phase coupling and synchrony in the spatiotemporal dynamics of muskrat and mink populations across Canada

PubMed Central

Haydon, D. T.; Stenseth, N. C.; Boyce, M. S.; Greenwood, P. E.

2001-01-01

Population ecologists have traditionally focused on the patterns and causes of population variation in the temporal domain for which a substantial body of practical analytic techniques have been developed. More recently, numerous studies have documented how populations may fluctuate synchronously over large spatial areas; analyses of such spatially extended time-series have started to provide additional clues regarding the causes of these population fluctuations and explanations for their synchronous occurrence. Here, we report on the development of a phase-based method for identifying coupling between temporally coincident but spatially distributed cyclic time-series, which we apply to the numbers of muskrat and mink recorded at 81 locations across Canada. The analysis reveals remarkable parallel clines in the strength of coupling between proximate populations of both species—declining from west to east—together with a corresponding increase in observed synchrony between these populations the further east they are located. PMID:11606729

Cytochrome b sequences in black-crowned night-herons (Nycticorax nycticorax) from heronries exposed to genotoxic contaminants

USGS Publications Warehouse

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.

High early life mortality in free-ranging dogs is largely influenced by humans

PubMed Central

Paul, Manabi; Sen Majumder, Sreejani; Sau, Shubhra; Nandi, Anjan K.; Bhadra, Anindita

2016-01-01

Free-ranging dogs are a ubiquitous part of human habitations in many developing countries, leading a life of scavengers dependent on human wastes for survival. The effective management of free-ranging dogs calls for understanding of their population dynamics. Life expectancy at birth and early life mortality are important factors that shape life-histories of mammals. We carried out a five year-long census based study in seven locations of West Bengal, India, to understand the pattern of population growth and factors affecting early life mortality in free-ranging dogs. We observed high rates of mortality, with only ~19% of the 364 pups from 95 observed litters surviving till the reproductive age; 63% of total mortality being human influenced. While living near people increases resource availability for dogs, it also has deep adverse impacts on their population growth, making the dog-human relationship on streets highly complex. PMID:26804633

The role of chemoprevention by selective cyclooxygenase-2 inhibitors in colorectal cancer patients - a population-based study

PubMed Central

2012-01-01

Background There are limited population-based studies focusing on the chemopreventive effects of selective cyclooxygenase-2 (COX-2) inhibitors against colorectal cancer. The purpose of this study is to assess the trends and dose–response effects of various medication possession ratios (MPR) of selective COX-2 inhibitor used for chemoprevention of colorectal cancer. Methods A population-based case–control study was conducted using the Taiwan Health Insurance Research Database (NHIRD). The study comprised 21,460 colorectal cancer patients and 79,331 controls. The conditional logistic regression was applied to estimate the odds ratios (ORs) for COX-2 inhibitors used for several durations (5 years, 3 years, 1 year, 6 months and 3 months) prior to the index date. Results In patients receiving selective COX-2 inhibitors, the OR was 0.51 (95% CI=0.29~0.90, p=0.021) for an estimated 5-year period in developing colorectal cancer. ORs showing significant protection effects were found in 10% of MPRs for 5-year, 3-year, and 1-year usage. Risk reduction against colorectal cancer by selective COX-2 inhibitors was observed as early as 6 months after usage. Conclusion Our results indicate that selective COX-2 inhibitors may reduce the development of colorectal cancer by at least 10% based on the MPRs evaluated. Given the limited number of clinical reports from general populations, our results add to the knowledge of chemopreventive effects of selective COX-2 inhibitors against cancer in individuals at no increased risk of colorectal cancer. PMID:23217168

The equivalence of a human observer and an ideal observer in binary diagnostic tasks

NASA Astrophysics Data System (ADS)

He, Xin; Samuelson, Frank; Gallas, Brandon D.; Sahiner, Berkman; Myers, Kyle

2013-03-01

The Ideal Observer (IO) is "ideal" for given data populations. In the image perception process, as the raw images are degraded by factors such as display and eye optics, there is an equivalent IO (EIO). The EIO uses the statistical information that exits the perception/cognitive degradations as the data. We assume a human observer who received sufficient training, e.g., radiologists, and hypothesize that such a human observer can be modeled as if he is an EIO. To measure the likelihood ratio (LR) distributions of an EIO, we formalize experimental design principles that encourage rationality based on von Neumann and Morgenstern's (vNM) axioms. We present examples to show that many observer study design refinements, although motivated by empirical principles explicitly, implicitly encourage rationality. Our hypothesis is supported by a recent review paper on ROC curve convexity by Pesce, Metz, and Berbaum. We also provide additional evidence based on a collection of observer studies in medical imaging. EIO theory shows that the "sub-optimal" performance of a human observer can be mathematically formalized in the form of an IO, and measured through rationality encouragement.

[Epidemiological methods used in studies in the prevalence of Tourette syndrome].

PubMed

Stefanoff, Paweł; Mazurek, Jacek

2003-01-01

Tourette syndrome (TS) prevalence was studied since the early 80-ies. Its clinical course is characterised by co-occurrence of motor and vocal tics. Results of previous epidemiological studies were surprisingly divergent: the prevalence varied from 0.5 to 115 cases per 10,000 population. The disease previously recognised as extremely rare and severe is now considered as quite common, with often moderate course. Selected methods used in studies of TS prevalence and analysis of their possible impact on study results are presented. The studies were divided into 3 groups: studies of the hospitalised population, large-scale screenings and studies involving school population, basing on characteristic and size of population, methods of selection of subjects, diagnostic and screening methods used. Studies of the hospitalised population involved patients with most severe symptoms, in different age groups, different methods of final diagnosis confirmation were used. TS prevalence varied from 0.5 up to 15 cases per 10,000 population. Procedures used in large-scale screening studies made possible the elimination of potential selection bias. Large populations were studied using transparent and repetitive confirmation of diagnoses. Their validity was additionally checked in parallel validity studies. TS prevalence was in the range 4.3 to 10 cases per 10,000 population. The highest TS prevalence was obtained in studies involving schoolchildren. Data were gathered from multiple sources: from parents, teachers and children, as well as from classroom observation. Diagnoses were made by experienced clinicians. TS prevalence obtained in school population studies was between 36.2 up to 115 per 10,000 population.

A Study of the Multiple Populations in M10

NASA Astrophysics Data System (ADS)

Gerber, Jeffrey M.; Friel, Eileen D.; Vesperini, Enrico

2017-06-01

We present an analysis of CN and CH band strengths which allow the identification of multiple populations in red giant stars in the globular cluster M10. Our measurements come from low-resolution spectroscopy obtained for ~140 red and asymptotic giant branch stars over two observation runs using Hydra on the WIYN 3.5m telescope. We sort the stars into nitrogen normal and enhanced populations based on the distribution of CN band strength as a function of magnitude. Once the stars are sorted into first and second generation (CN normal and enhanced, respectively), we compare this analysis to other ways of determining multiple stellar populations such as with the light elements Na and O and photometric indicators, particularly the UV photometry from the Hubble Space Telescope. C and N abundances are determined by matching observed CN and CH band measurements with those produced by synthetic spectra created with the Synthetic Spectrum Generator (SSG). The large sample size also allows us to study characteristics like radial distribution, and evolutionary effects such as the depletion of carbon (and subsequent nitrogen enrichment) as a star climbs the red giant branch. We find a rate of carbon depletion as a function of time for both populations in M10 and compare our result to M13, a cluster similar in metallicity.

Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

PubMed

David, Lior; Rosenberg, Noah A; Lavi, Uri; Feldman, Marcus W; Hillel, Jossi

2007-01-01

Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L.), a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi) variants. Grass carp (Ctenopharyngodon idella) was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp) to 32% (koi) and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication.

Genetic diversity and population structure inferred from the partially duplicated genome of domesticated carp, Cyprinus carpio L.

PubMed Central

David, Lior; Rosenberg, Noah A; Lavi, Uri; Feldman, Marcus W; Hillel, Jossi

2007-01-01

Genetic relationships among eight populations of domesticated carp (Cyprinus carpio L.), a species with a partially duplicated genome, were studied using 12 microsatellites and 505 AFLP bands. The populations included three aquacultured carp strains and five ornamental carp (koi) variants. Grass carp (Ctenopharyngodon idella) was used as an outgroup. AFLP-based gene diversity varied from 5% (grass carp) to 32% (koi) and reflected the reasonably well understood histories and breeding practices of the populations. A large fraction of the molecular variance was due to differences between aquacultured and ornamental carps. Further analyses based on microsatellite data, including cluster analysis and neighbor-joining trees, supported the genetic distinctiveness of aquacultured and ornamental carps, despite the recent divergence of the two groups. In contrast to what was observed for AFLP-based diversity, the frequency of heterozygotes based on microsatellites was comparable among all populations. This discrepancy can potentially be explained by duplication of some loci in Cyprinus carpio L., and a model that shows how duplication can increase heterozygosity estimates for microsatellites but not for AFLP loci is discussed. Our analyses in carp can help in understanding the consequences of genotyping duplicated loci and in interpreting discrepancies between dominant and co-dominant markers in species with recent genome duplication. PMID:17433244

Macronutrient, vitamin, and mineral intakes in the EPIC-Germany cohorts.

PubMed

Schulze, M B; Linseisen, J; Kroke, A; Boeing, H

2001-01-01

This article presents intakes of nutrients in the EPIC-Heidelberg and the EPIC-Potsdam (European Investigation into Cancer and Nutrition) studies. Estimates are based on standardized 24-hour dietary recalls. Recalls from 1,013 men and 1,078 women in Heidelberg and from 1,032 men and 898 women in Potsdam were included in the analysis. The estimated nutrient intake was based on the German Food Code and Nutrient Data Base version II.3. Analyses were carried out stratified by sex and weighted for the day of the week and age. Men in Potsdam reported significantly higher intakes of energy (mean Potsdam = 10,718 kJ, mean Heidelberg = 10,387 kJ) and higher intakes of vitamins and minerals as compared with men in Heidelberg. However, Heidelberg men consumed more alcohol, alpha-tocopherol, phosphorus, calcium, and magnesium. Potsdam women reported lower energy (mean Potsdam = 7,537 kJ, mean Heidelberg = 7,855 kJ), alcohol, and cholesterol intakes as compared with Heidelberg women. Vitamin and mineral intakes were lower too, except for retinol and ascorbic acid. The intakes of energy and most nutrients observed in the Potsdam and Heidelberg study populations were within the range reported from other German studies. The observed differences between both study populations indicate different dietary patterns, increasing the exposure variation in the EPIC study. Copyright 2001 S. Karger AG, Basel

Using multiple data types and integrated population models to improve our knowledge of apex predator population dynamics

USGS Publications Warehouse

Bled, Florent; Belant, Jerrold L.; Van Daele, Lawrence J.; Svoboda, Nathan; Gustine, David D.; Hilderbrand, Grant V.; Barnes, Victor G.

2017-01-01

Current management of large carnivores is informed using a variety of parameters, methods, and metrics; however, these data are typically considered independently. Sharing information among data types based on the underlying ecological, and recognizing observation biases, can improve estimation of individual and global parameters. We present a general integrated population model (IPM), specifically designed for brown bears (Ursus arctos), using three common data types for bear (U. spp.) populations: repeated counts, capture–mark–recapture, and litter size. We considered factors affecting ecological and observation processes for these data. We assessed the practicality of this approach on a simulated population and compared estimates from our model to values used for simulation and results from count data only. We then present a practical application of this general approach adapted to the constraints of a case study using historical data available for brown bears on Kodiak Island, Alaska, USA. The IPM provided more accurate and precise estimates than models accounting for repeated count data only, with credible intervals including the true population 94% and 5% of the time, respectively. For the Kodiak population, we estimated annual average litter size (within one year after birth) to vary between 0.45 [95% credible interval: 0.43; 0.55] and 1.59 [1.55; 1.82]. We detected a positive relationship between salmon availability and adult survival, with survival probabilities greater for females than males. Survival probabilities increased from cubs to yearlings to dependent young ≥2 years old and decreased with litter size. Linking multiple information sources based on ecological and observation mechanisms can provide more accurate and precise estimates, to better inform management. IPMs can also reduce data collection efforts by sharing information among agencies and management units. Our approach responds to an increasing need in bear populations’ management and can be readily adapted to other large carnivores.

Probing the X-Ray Binary Populations of the Ring Galaxy NGC 1291

NASA Technical Reports Server (NTRS)

Luo, B.; Fabbiano, G.; Fragos, T.; Kim, D. W.; Belczynski, K.; Brassington, N. J.; Pellegrini, S.; Tzanavaris, P.; Wang, J.; Zezas, A.

2012-01-01

We present Chandra studies of the X-ray binary (XRB) populations in the bulge and ring regions of the ring galaxy NGC 1291. We detect 169 X-ray point sources in the galaxy, 75 in the bulge and 71 in the ring, utilizing the four available Chandra observations totaling an effective exposure of 179 ks. We report photometric properties of these sources in a point-source catalog. There are approx. 40% of the bulge sources and approx. 25% of the ring sources showing > 3(sigma) long-term variability in their X-ray count rate. The X-ray colors suggest that a significant fraction of the bulge (approx. 75%) and ring (approx. 65%) sources are likely low-mass X-ray binaries (LMXBs). The spectra of the nuclear source indicate that it is a low-luminosity AGN with moderate obscuration; spectral variability is observed between individual observations. We construct 0.3-8.0 keV X-ray luminosity functions (XLFs) for the bulge and ring XRB populations, taking into account the detection incompleteness and background AGN contamination. We reach 90% completeness limits of approx.1.5 x 10(exp 37) and approx. 2.2 x 10(exp 37) erg/s for the bulge and ring populations, respectively. Both XLFs can be fit with a broken power-law model, and the shapes are consistent with those expected for populations dominated by LMXBs. We perform detailed population synthesis modeling of the XRB populations in NGC 1291 , which suggests that the observed combined XLF is dominated by aD old LMXB population. We compare the bulge and ring XRB populations, and argue that the ring XRBs are associated with a younger stellar population than the bulge sources, based on the relative over-density of X-ray sources in the ring, the generally harder X-ray color of the ring sources, the overabundance of luminous sources in the combined XLF, and the flatter shape of the ring XLF.

Rising Use Of Observation Care Among The Commercially Insured May Lead to Total And Out-Of-Pocket Cost Savings.

PubMed

Adrion, Emily R; Kocher, Keith E; Nallamothu, Brahmajee K; Ryan, Andrew M

2017-12-01

Proponents of hospital-based observation care argue that it has the potential to reduce health care spending and lengths-of-stay, compared to short-stay inpatient hospitalizations. However, critics have raised concerns about the out-of-pocket spending associated with observation care. Recent reports of high out-of-pocket spending among Medicare beneficiaries have received considerable media attention and have prompted direct policy changes. Despite the potential for changed policies to indirectly affect non-Medicare patients, little is known about the use of, and spending associated with, observation care among commercially insured populations. Using multipayer commercial claims for the period 2009-13, we evaluated utilization and spending among patients admitted for six conditions that are commonly managed with either observation care or short-stay hospitalizations. In our study period, the use of observation care increased relative to that of short-stay hospitalizations. Total and out-of-pocket spending were substantially lower for observation care, though both grew rapidly-and at rates much higher than spending in the inpatient setting-over the study period. Despite this growth, spending on observation care is unlikely to exceed spending for short-stay hospitalizations. As observation care attracts greater attention, policy makers should be aware that Medicare policies that disincentivize observation may have unintended financial impacts on non-Medicare populations, where observation care may be cost saving.

Three Decades of Farmed Escapees in the Wild: A Spatio-Temporal Analysis of Atlantic Salmon Population Genetic Structure throughout Norway

PubMed Central

Glover, Kevin A.; Quintela, María; Wennevik, Vidar; Besnier, François; Sørvik, Anne G. E.; Skaala, Øystein

2012-01-01

Each year, hundreds of thousands of domesticated farmed Atlantic salmon escape into the wild. In Norway, which is the world’s largest commercial producer, many native Atlantic salmon populations have experienced large numbers of escapees on the spawning grounds for the past 15–30 years. In order to study the potential genetic impact, we conducted a spatio-temporal analysis of 3049 fish from 21 populations throughout Norway, sampled in the period 1970–2010. Based upon the analysis of 22 microsatellites, individual admixture, FST and increased allelic richness revealed temporal genetic changes in six of the populations. These changes were highly significant in four of them. For example, 76% and 100% of the fish comprising the contemporary samples for the rivers Vosso and Opo were excluded from their respective historical samples at P = 0.001. Based upon several genetic parameters, including simulations, genetic drift was excluded as the primary cause of the observed genetic changes. In the remaining 15 populations, some of which had also been exposed to high numbers of escapees, clear genetic changes were not detected. Significant population genetic structuring was observed among the 21 populations in the historical (global FST = 0.038) and contemporary data sets (global FST = 0.030), although significantly reduced with time (P = 0.008). This reduction was especially distinct when looking at the six populations displaying temporal changes (global FST dropped from 0.058 to 0.039, P = 0.006). We draw two main conclusions: 1. The majority of the historical population genetic structure throughout Norway still appears to be retained, suggesting a low to modest overall success of farmed escapees in the wild; 2. Genetic introgression of farmed escapees in native salmon populations has been strongly population-dependent, and it appears to be linked with the density of the native population. PMID:22916215

HLA-A, -B, -C, -DQB1, and -DRB1,3,4,5 allele and haplotype frequencies in the Costa Rica Central Valley Population and its relationship to worldwide populations.

PubMed

Arrieta-Bolaños, Esteban; Maldonado-Torres, Hazael; Dimitriu, Oana; Hoddinott, Michael A; Fowles, Finnuala; Shah, Anila; Orlich-Pérez, Priscilla; McWhinnie, Alasdair J; Alfaro-Bourrouet, Wilbert; Buján-Boza, Willem; Little, Ann-Margaret; Salazar-Sánchez, Lizbeth; Madrigal, J Alejandro

2011-01-01

The human leukocyte antigen (HLA) system is the most polymorphic in humans. Its allele, genotype, and haplotype frequencies vary significantly among different populations. Molecular typing data on HLA are necessary for the development of stem cell donor registries, cord blood banks, HLA-disease association studies, and anthropology studies. The Costa Rica Central Valley Population (CCVP) is the major population in this country. No previous study has characterized HLA frequencies in this population. Allele group and haplotype frequencies of HLA genes in the CCVP were determined by means of molecular typing in a sample of 130 unrelated blood donors from one of the country's major hospitals. A comparison between these frequencies and those of 126 populations worldwide was also carried out. A minimum variance dendrogram based on squared Euclidean distances was constructed to assess the relationship between the CCVP sample and populations from all over the world. Allele group and haplotype frequencies observed in this study are consistent with a profile of a dynamic and diverse population, with a hybrid ethnic origin, predominantly Caucasian-Amerindian. Results showed that populations genetically closest to the CCVP are a Mestizo urban population from Venezuela, and another one from Guadalajara, Mexico. Copyright © 2011 American Society for Histocompatibility and Immunogenetics. All rights reserved.

Inbreeding depression by environment interactions in a free-living mammal population

PubMed Central

Pemberton, J M; Ellis, P E; Pilkington, J G; Bérénos, C

2017-01-01

Experimental studies often find that inbreeding depression is more severe in harsh environments, but the few studies of in situ wild populations available to date rarely find strong support for this effect. We investigated evidence for inbreeding depression by environment interactions in nine traits in the individually monitored Soay sheep population of St Kilda, using genomic inbreeding coefficients based on 37 037 single-nucleotide polymorphism loci, and population density as an axis of environmental variation. All traits showed variation with population density and all traits showed some evidence for depression because of either an individual's own inbreeding or maternal inbreeding. However, only six traits showed evidence for an interaction in the expected direction, and only two interactions were statistically significant. We identify three possible reasons why wild population studies may generally fail to find strong support for interactions between inbreeding depression and environmental variation compared with experimental studies. First, for species with biparental inbreeding only, the amount of observed inbreeding in natural populations is generally low compared with that used in experimental studies. Second, it is possible that experimental studies sometimes actually impose higher levels of stress than organisms experience in the wild. Third, some purging of the deleterious recessive alleles that underpin interaction effects may occur in the wild. PMID:27876804

Inbreeding depression by environment interactions in a free-living mammal population.

PubMed

Pemberton, J M; Ellis, P E; Pilkington, J G; Bérénos, C

2017-01-01

Experimental studies often find that inbreeding depression is more severe in harsh environments, but the few studies of in situ wild populations available to date rarely find strong support for this effect. We investigated evidence for inbreeding depression by environment interactions in nine traits in the individually monitored Soay sheep population of St Kilda, using genomic inbreeding coefficients based on 37 037 single-nucleotide polymorphism loci, and population density as an axis of environmental variation. All traits showed variation with population density and all traits showed some evidence for depression because of either an individual's own inbreeding or maternal inbreeding. However, only six traits showed evidence for an interaction in the expected direction, and only two interactions were statistically significant. We identify three possible reasons why wild population studies may generally fail to find strong support for interactions between inbreeding depression and environmental variation compared with experimental studies. First, for species with biparental inbreeding only, the amount of observed inbreeding in natural populations is generally low compared with that used in experimental studies. Second, it is possible that experimental studies sometimes actually impose higher levels of stress than organisms experience in the wild. Third, some purging of the deleterious recessive alleles that underpin interaction effects may occur in the wild.

Optimal Sequence of Irinotecan and Oxaliplatin-Based Regimens in Metastatic Colorectal Cancer: A Population-Based Observational Study

PubMed Central

Lin, Ching-Heng; Hwang, Wen-Li

2015-01-01

The optimal sequence of irinotecan and oxaliplatin-based regimens for metastatic colorectal cancer remains unclear. We conducted a population-based observational study by retrospectively reviewing records from Taiwan’s National Health Insurance Research Database to explore this issue. Patients aged ≥20 years with metastatic colorectal cancer newly diagnosed between 2004 and 2008 (n = 9490) were enrolled in current study. Among these 9490 patients, 3895 patients (41.04%) did not receive any chemotherapy within the first three months after catastrophic illness registration. Patients who received best supportive care were older and had higher Charlson comorbidity indexes and incidences of comorbidities than those who received irinotecan-based regimens, oxaliplatin-based regimens, and 5-fluorouracil/capecitabine alone. Patients who received irinotecan followed by oxaliplatin-based regimens and those who received the reverse sequence were further stratified into arm A (n = 542) and arm B (n = 1156), respectively. The median first time to next treatment was not significantly different between arm A and arm B (210 days vs. 196 days; p = 0.17). However, the median second time to next treatment was longer in arm A than in arm B (155 days vs. 123 days; p = 0.006), which translated into a better overall survival (487 days vs. 454 days; p = 0.02). The crossover rate was higher in arm A than in arm B (47.84% vs. 41.61%; p<0.001). Multivariate Cox regression analyses showed that overall survival was comparable between the two chemotherapy sequences (p = 0.27). Our study suggested that irinotecan followed by oxaliplatin-based regimens might be a better chemotherapy treatment option for metastatic colorectal cancer than the reverse sequence given the higher crossover rate and potential overall survival benefit. PMID:26273837

Optimal Sequence of Irinotecan and Oxaliplatin-Based Regimens in Metastatic Colorectal Cancer: A Population-Based Observational Study.

PubMed

Teng, Chieh-Lin Jerry; Wang, Chen-Yu; Chen, Yi-Huei; Lin, Ching-Heng; Hwang, Wen-Li

2015-01-01

The optimal sequence of irinotecan and oxaliplatin-based regimens for metastatic colorectal cancer remains unclear. We conducted a population-based observational study by retrospectively reviewing records from Taiwan's National Health Insurance Research Database to explore this issue. Patients aged ≥ 20 years with metastatic colorectal cancer newly diagnosed between 2004 and 2008 (n = 9490) were enrolled in current study. Among these 9490 patients, 3895 patients (41.04%) did not receive any chemotherapy within the first three months after catastrophic illness registration. Patients who received best supportive care were older and had higher Charlson comorbidity indexes and incidences of comorbidities than those who received irinotecan-based regimens, oxaliplatin-based regimens, and 5-fluorouracil/capecitabine alone. Patients who received irinotecan followed by oxaliplatin-based regimens and those who received the reverse sequence were further stratified into arm A (n = 542) and arm B (n = 1156), respectively. The median first time to next treatment was not significantly different between arm A and arm B (210 days vs. 196 days; p = 0.17). However, the median second time to next treatment was longer in arm A than in arm B (155 days vs. 123 days; p = 0.006), which translated into a better overall survival (487 days vs. 454 days; p = 0.02). The crossover rate was higher in arm A than in arm B (47.84% vs. 41.61%; p<0.001). Multivariate Cox regression analyses showed that overall survival was comparable between the two chemotherapy sequences (p = 0.27). Our study suggested that irinotecan followed by oxaliplatin-based regimens might be a better chemotherapy treatment option for metastatic colorectal cancer than the reverse sequence given the higher crossover rate and potential overall survival benefit.

Genetic diversity and population genetic analysis of bovine MHC class II DRB3.2 locus in three Bos indicus cattle breeds of Southern India.

PubMed

Das, D N; Sri Hari, V G; Hatkar, D N; Rengarajan, K; Saravanan, R; Suryanarayana, V V S; Murthy, L K

2012-12-01

The present study was performed to evaluate the genetic polymorphism of BoLA-DRB3.2 locus in Malnad Gidda, Hallikar and Ongole South Indian Bos indicus cattle breeds, employing the PCR-RFLP technique. In Malnad Gidda population, 37 BoLA-DRB3.2 alleles were detected, including one novel allele DRB3*2503 (GenBank: HM031389) that was observed in the frequency of 1.87%. In Hallikar and Ongole populations, 29 and 21 BoLA-DRB3.2 alleles were identified, respectively. The frequencies of the most common BoLA-DRB3.2 alleles (with allele frequency > 5%), in Malnad Gidda population, were DRB3.2*15 (10.30%), DRB3*5702 (9.35%), DRB3.2*16 (8.41%), DRB3.2*23 (7.01%) and DRB3.2*09 (5.61%). In Hallikar population, the most common alleles were DRB3.2*11 (13.00%), DRB3.2*44 (11.60%), DRB3.2*31 (10.30%), DRB3.2*28 (5.48%) and DRB3.2*51 (5.48%). The most common alleles in Ongole population were DRB3.2*15 (22.50%), DRB3.2*06 (20.00%), DRB3.2*13 (13.30%), DRB3.2*12 (9.17%) and DRB3.2*23 (7.50%). A high degree of heterozygosity observed in Malnad Gidda (H(O) = 0.934, H(E) = 0.955), Hallikar (H(O) = 0.931, H(E) = 0.943) and Ongole (H(O) = 0.800, H(E) = 0.878) populations, along with F(IS) values close to F(IS) zero (Malnad Gidda: F(IS) = 0.0221, Hallikar: F(IS) = 0.0127 and Ongole: F(IS) = 0.0903), yielded nonsignificant P-values with respect to Hardy-Weinberg equilibrium probabilities revealing, no perceptible inbreeding, greater genetic diversity and characteristic population structure being preserved in the three studied cattle populations. The phylogenetic tree constructed based on the frequencies of BoLA-DRB3.2 alleles observed in 10 Bos indicus and Bos taurus cattle breeds revealed distinct clustering of specific Bos indicus cattle breeds, along with unique genetic differentiation observed among them. The results of this study demonstrated that the BoLA-DRB3.2 is a highly polymorphic locus, with significant breed-specific genetic diversities being present amongst the three studied cattle breeds. The population genetics and phylogenetic analysis have revealed pivotal information about the population structure and importance of the presently studied three Bos indicus cattle breeds as unique animal genetic resources, which have to be conserved for maintaining native cattle genetic diversity. © 2012 Blackwell Publishing Ltd.

Turing patterns and a stochastic individual-based model for predator-prey systems

NASA Astrophysics Data System (ADS)

Nagano, Seido

2012-02-01

Reaction-diffusion theory has played a very important role in the study of pattern formations in biology. However, a group of individuals is described by a single state variable representing population density in reaction-diffusion models and interaction between individuals can be included only phenomenologically. Recently, we have seamlessly combined individual-based models with elements of reaction-diffusion theory. To include animal migration in the scheme, we have adopted a relationship between the diffusion and the random numbers generated according to a two-dimensional bivariate normal distribution. Thus, we have observed the transition of population patterns from an extinction mode, a stable mode, or an oscillatory mode to the chaotic mode as the population growth rate increases. We show our phase diagram of predator-prey systems and discuss the microscopic mechanism for the stable lattice formation in detail.

Mortality, migration, income, and air pollution: a comparative study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bozzo, S.R.; Novak, K.M.; Galdos, F.

1978-06-02

The interrelationships among different demographic factors, specific causes of death, median family income, and estimated air pollution emissions were examined. Using the Medical Data Base (MEDABA) developed at Brookhaven National Laboratory, the entire population of the United States was cross-tabulated by income and emission levels of air pollutants. Path analysis was used to examine a number of patterns and relationships for each age, race, and sex group containing a minimum of 10,000 persons. Competitive and complementary effects were observed. These effects were frequently age dependent and occasionaly sex related. This specialized data base, the application of path analysis, and themore » development of a dynamic population and mortality model, in combination, proved to be a useful tool for investigating the effects of energy related pollutants on the exposed population.« less

Cancer risk diversity in non-western migrants to Europe: An overview of the literature.

PubMed

Arnold, Melina; Razum, Oliver; Coebergh, Jan-Willem

2010-09-01

Cancer risk varies geographically and across ethnic groups that can be monitored in cancer control to respond to observed trends as well as ensure appropriate health care. The study of cancer risk in immigrant populations has great potential to contribute new insights into aetiology, diagnosis and treatment of cancer. Disparities in cancer risk patterns between immigrant and autochthonous populations have been reported many times, but up to now studies have been heterogeneous and may be discordant in their findings. The aim of this overview was to compile and compare studies on cancer occurrence in migrant populations from non-western countries residing in Western Europe in order to reflect current knowledge in this field and to appeal for further research and culturally sensitive prevention strategies. We included 37 studies published in the English language between 1990 and April 2010 focussing on cancer in adult migrants from non-western countries, living in the industrialised countries of the European Union. Migrants were defined based on their country of birth, ethnicity and name-based approaches. We conducted a between-country comparison of age-adjusted cancer incidence and mortality in immigrant populations with those in autochthonous populations. Across the board migrants from non-western countries showed a more favourable all-cancer morbidity and mortality compared with native populations of European host countries, but with considerable site-specific risk diversity: Migrants from non-western countries were more prone to cancers that are related to infections experienced in early life, such as liver, cervical and stomach cancer. In contrast, migrants of non-western origin were less likely to suffer from cancers related to a western lifestyle, e.g. colorectal, breast and prostate cancer. Confirming the great cancer risk diversity in non-western migrants in and between different European countries, this overview reaffirms the importance of exposures experienced during life course (before, during and after migration) for carcinogenesis. Culturally sensitive cancer prevention programmes should focus on individual risk patterns and specific health care needs. Therefore, continuously changing environments and subsequently changing risks in both migrant and autochthonous populations need to be observed carefully in the future. Copyright © 2010 Elsevier Ltd. All rights reserved.

A genomic insight into the peopling of Manipur, India.

PubMed

Meitei, Khangembam Somibabu; Meitei, Sanjenbam Yaiphaba; Asghar, Mohammad; Achoubi, Nongthombam; Murry, Benrithung; Mondal, Prakash Ranjan; Sachdeva, Mohinder Pal; Saraswathy, Kallur Nava

2010-12-01

manipur, one of the northeastern states of India, lies on the ancient silk route and serves as a meeting point between the Southeast Asia and South Asia. this study was conducted to understand and estimate the genomic diversity among various population groups of Manipur, with a major goal of getting an insight into the peopling of India. seven human-specific Alu insertion/deletion polymorphisms were screened on 366 individuals belonging to eight ethnic groups of Manipur, including both tribal (Aimol, Kabui, Kom, Paite, and Thadou) and nontribal populations (Bamon, Muslims, and Meitei). all the biallelic loci are polymorphic except CD4, which is monomorphic in six out of the eight studied populations. The average heterozygosity values are low (0.309-0.395), with relatively higher average heterozygosity values among Bamons and Muslims than other studied populations, suggesting admixture in these two populations. Lower heterozygosity values of the tribal populations place them closer to the Chinese and Southeast Asian populations, indicating their late arrival in India coupled with geographical isolation. this study provides evidence for the genetic heterogeneity of the Manipur populations. It also supports the hypothesis, based on the archeological and linguistic findings, that the northeastern populations of India have a close genetic affinity with the southeastern and East Asian populations. The genetic discontinuity observed between the studied populations and the other non-Northeast Indian populations suggests the role of northeast border as a "barrier" rather than a corridor.

Population Accessibility to Radiotherapy Services in New South Wales Region of Australia: a methodological contribution

NASA Astrophysics Data System (ADS)

Shukla, Nagesh; Wickramasuriya, Rohan; Miller, Andrew; Perez, Pascal

2015-05-01

This paper proposes an integrated modelling process to assess the population accessibility to radiotherapy treatment services in future based on future cancer incidence and road network-based accessibility. Previous research efforts assessed travel distance/time barriers affecting access to cancer treatment services, as well as epidemiological studies that showed that cancer incidence rates vary with population demography. It is established that travel distances to treatment centres and demographic profiles of the accessible regions greatly influence the demand for cancer radiotherapy (RT) services. However, an integrated service planning approach that combines spatially-explicit cancer incidence projections, and the RT services accessibility based on patient road network have never been attempted. This research work presents this novel methodology for the accessibility assessment of RT services and demonstrates its viability by modelling New South Wales (NSW) cancer incidence rates for different age-sex groups based on observed cancer incidence trends; estimating the road network-based access to current NSW treatment centres; and, projecting the demand for RT services in New South Wales, Australia from year 2011 to 2026.

The Use of Surrogate Data in Demographic Population Viability Analysis: A Case Study of California Sea Lions

PubMed Central

2015-01-01

Reliable data necessary to parameterize population models are seldom available for imperiled species. As an alternative, data from populations of the same species or from ecologically similar species have been used to construct models. In this study, we evaluated the use of demographic data collected at one California sea lion colony (Los Islotes) to predict the population dynamics of the same species from two other colonies (San Jorge and Granito) in the Gulf of California, Mexico, for which demographic data are lacking. To do so, we developed a stochastic demographic age-structured matrix model and conducted a population viability analysis for each colony. For the Los Islotes colony we used site-specific pup, juvenile, and adult survival probabilities, as well as birth rates for older females. For the other colonies, we used site-specific pup and juvenile survival probabilities, but used surrogate data from Los Islotes for adult survival probabilities and birth rates. We assessed these models by comparing simulated retrospective population trajectories to observed population trends based on count data. The projected population trajectories approximated the observed trends when surrogate data were used for one colony but failed to match for a second colony. Our results indicate that species-specific and even region-specific surrogate data may lead to erroneous conservation decisions. These results highlight the importance of using population-specific demographic data in assessing extinction risk. When vital rates are not available and immediate management actions must be taken, in particular for imperiled species, we recommend the use of surrogate data only when the populations appear to have similar population trends. PMID:26413746

Often Asked but Rarely Answered: Can Asians Meet DSM-5/ICD-10 Autism Spectrum Disorder Criteria?

PubMed Central

Kim, So Hyun; Koh, Yun-Joo; Lim, Eun-Chung; Kim, Soo-Jeong; Leventhal, Bennett L.

2016-01-01

Abstract Objectives: To evaluate whether Asian (Korean children) populations can be validly diagnosed with autism spectrum disorder (ASD) using Western-based diagnostic instruments and criteria based on Diagnostic and Statistical Manual on Mental Disorders, 5th edition (DSM-5). Methods: Participants included an epidemiologically ascertained 7–14-year-old (N = 292) South Korean cohort from a larger prevalence study (N = 55,266). Main outcomes were based on Western-based diagnostic methods for Korean children using gold standard instruments, Autism Diagnostic Interview-Revised, and Autism Diagnostic Observation Schedule. Factor analysis and ANOVAs were performed to examine factor structure of autism symptoms and identify phenotypic differences between Korean children with ASD and non-ASD diagnoses. Results: Using Western-based diagnostic methods, Korean children with ASD were successfully identified with moderate-to-high diagnostic validity (sensitivities/specificities ranging 64%–93%), strong internal consistency, and convergent/concurrent validity. The patterns of autism phenotypes in a Korean population were similar to those observed in a Western population with two symptom domains (social communication and restricted and repetitive behavior factors). Statistically significant differences in the use of socially acceptable communicative behaviors (e.g., direct gaze, range of facial expressions) emerged between ASD versus non-ASD cases (mostly p < 0.001), ensuring that these can be a similarly valid part of the ASD phenotype in both Asian and Western populations. Conclusions: Despite myths, biases, and stereotypes about Asian social behavior, Asians (at least Korean children) typically use elements of reciprocal social interactions similar to those in the West. Therefore, standardized diagnostic methods widely used for ASD in Western culture can be validly used as part of the assessment process and research with Koreans and, possibly, other Asians. PMID:27315155

Detection of sea otters in boat-based surveys of Prince William Sound, Alaska

USGS Publications Warehouse

Udevitz, Mark S.; Bodkin, James L.; Costa, Daniel P.

1995-01-01

Boat-based surveys have been commonly used to monitor sea otter populations, but there has been little quantitative work to evaluate detection biases that may affect these surveys. We used ground-based observers to investigate sea otter detection probabilities in a boat-based survey of Prince William Sound, Alaska. We estimated that 30% of the otters present on surveyed transects were not detected by boat crews. Approximately half (53%) of the undetected otters were missed because the otters left the transects, apparently in response to the approaching boat. Unbiased estimates of detection probabilities will be required for obtaining unbiased population estimates from boat-based surveys of sea otters. Therefore, boat-based surveys should include methods to estimate sea otter detection probabilities under the conditions specific to each survey. Unbiased estimation of detection probabilities with ground-based observers requires either that the ground crews detect all of the otters in observed subunits, or that there are no errors in determining which crews saw each detected otter. Ground-based observer methods may be appropriate in areas where nearly all of the sea otter habitat is potentially visible from ground-based vantage points.

Chronic care coordination by integrating care through a team-based, population-driven approach: a case study.

PubMed

van Eeghen, Constance O; Littenberg, Benjamin; Kessler, Rodger

2018-05-23

Patients with chronic conditions frequently experience behavioral comorbidities to which primary care cannot easily respond. This study observed a Vermont family medicine practice with integrated medical and behavioral health services that use a structured approach to implement a chronic care management system with Lean. The practice chose to pilot a population-based approach to improve outcomes for patients with poorly controlled Type 2 diabetes using a stepped-care model with an interprofessional team including a community health nurse. This case study observed the team's use of Lean, with which it designed and piloted a clinical algorithm composed of patient self-assessment, endorsement of behavioral goals, shared documentation of goals and plans, and follow-up. The team redesigned workflows and measured reach (patients who engaged to the end of the pilot), outcomes (HbA1c results), and process (days between HbA1c tests). The researchers evaluated practice member self-reports about the use of Lean and facilitators and barriers to move from pilot to larger scale applications. Of 20 eligible patients recruited over 3 months, 10 agreed to participate and 9 engaged fully (45%); 106 patients were controls. Relative to controls, outcomes and process measures improved but lacked significance. Practice members identified barriers that prevented implementation of all changes needed but were in agreement that the pilot produced useful outcomes. A systematized, population-based, chronic care management service is feasible in a busy primary care practice. To test at scale, practice leadership will need to allocate staffing, invest in shared documentation, and standardize workflows to streamline office practice responsibilities.

Challenges on the epidemiological and economic burden of diabetes and hypertension in Mexico.

PubMed

Arredondo, Armando; Orozco, Emanuel; Alcalde-Rabanal, Jaqueline; Navarro, Juan; Azar, Alejandra

2018-01-01

OBJECTIVE To analyze the epidemiological and economic burden of the health services demand due to diabetes and hypertension in Mexico. METHODS Evaluation study based on a time series study that had as a universe of study the assured and uninsured population that demands health services from the three main institutions of the Health System in Mexico: The Health Department, the Mexican Institute of Social Security, and Institute of Services and Social Security for State Workers. The financing method was based on instrumentation and consensus techniques for medium case management. In order to estimate the epidemiological changes and financial requirements, a time series of observed cases for diabetes and hypertension 1994-2013 was integrated. Probabilistic models were developed based on the Box-Jenkins technique for the period of 2013-2018 with 95% confidence intervals and p < 0.05. RESULTS Comparing results from 2013 versus 2018, in the five regions, different incremental trends of 14%-17% in epidemiological changes and 58%-66% in the economic burden for both diseases were observed. CONCLUSIONS If the risk factors and the different models of care remained as they currently are in the three institutions analyzed, the financial consequences would be of greater impact for the Mexican Institute of Social Security, following in order of importance the Institute of Services and Social Security for State Workers and lastly the Health Department. The financial needs for both diseases will represent approximately 13%-15% of the total budget allocated to the uninsured population and 15%-17% for the population insured depending on the region.

Challenges on the epidemiological and economic burden of diabetes and hypertension in Mexico

PubMed Central

Arredondo, Armando; Orozco, Emanuel; Alcalde-Rabanal, Jaqueline; Navarro, Juan; Azar, Alejandra

2018-01-01

ABSTRACT OBJECTIVE To analyze the epidemiological and economic burden of the health services demand due to diabetes and hypertension in Mexico. METHODS Evaluation study based on a time series study that had as a universe of study the assured and uninsured population that demands health services from the three main institutions of the Health System in Mexico: The Health Department, the Mexican Institute of Social Security, and Institute of Services and Social Security for State Workers. The financing method was based on instrumentation and consensus techniques for medium case management. In order to estimate the epidemiological changes and financial requirements, a time series of observed cases for diabetes and hypertension 1994–2013 was integrated. Probabilistic models were developed based on the Box-Jenkins technique for the period of 2013–2018 with 95% confidence intervals and p < 0.05. RESULTS Comparing results from 2013 versus 2018, in the five regions, different incremental trends of 14%–17% in epidemiological changes and 58%-66% in the economic burden for both diseases were observed. CONCLUSIONS If the risk factors and the different models of care remained as they currently are in the three institutions analyzed, the financial consequences would be of greater impact for the Mexican Institute of Social Security, following in order of importance the Institute of Services and Social Security for State Workers and lastly the Health Department. The financial needs for both diseases will represent approximately 13%–15% of the total budget allocated to the uninsured population and 15%–17% for the population insured depending on the region. PMID:29489993

Trends and changes in paediatric tonsil surgery in Sweden 1987–2013: a population-based cohort study

PubMed Central

Borgström, Anna; Nerfeldt, Pia; Friberg, Danielle; Sunnergren, Ola; Stalfors, Joacim

2017-01-01

Objectives The objective of this study was to longitudinally describe the history of tonsil surgery in Swedish children and adolescents regarding incidence, indications for surgery, surgical methods and the age and gender distributions. Setting A retrospective longitudinal population-based cohort study based on register data from the Swedish National Patient Register (NPR) and population data from Statistics Sweden. Participants All Swedish children 1–<18 years registered in the NPR with a tonsil surgery procedure 1987–2013. Results 167 894 tonsil surgeries were registered in the NPR 1987–2013. An increase in the total incidence rate was observed, from 22/10 000 person years in 1987 to 47/10 000 in 2013. The most marked increase was noted in children 1–3 years of age, increasing from 17 to 73/10 000 person years over the period. The proportion children with obstructive/sleep disordered breathing (SDB) indications increased from 42.4% in 1987 to 73.6% in 2013. Partial tonsillectomy, tonsillotomy (TT), increased since 1996 and in 2013 55.1% of all tonsil procedures were TTs. Conclusions There have been considerable changes in clinical practice for tonsil surgery in Swedish children over the past few decades. Overall, a doubling in the total incidence rate was observed. This increase consisted mainly of an increase in surgical procedures due to obstructive/SDB indications, particularly among the youngest age group (1–3 years old). TT has gradually replaced tonsillectomy as the predominant method for tonsil surgery. PMID:28087550

The effectiveness of snow cube throwing learning model based on exploration

NASA Astrophysics Data System (ADS)

Sari, Nenden Mutiara

2017-08-01

This study aimed to know the effectiveness of Snow Cube Throwing (SCT) and Cooperative Model in Exploration-Based Math Learning in terms of the time required to complete the teaching materials and student engagement. This study was quasi-experimental research was conducted at SMPN 5 Cimahi, Indonesia. All student in grade VIII SMPN 5 Cimahi which consists of 382 students is used as population. The sample consists of two classes which had been chosen randomly with purposive sampling. First experiment class consists of 38 students and the second experiment class consists of 38 students. Observation sheet was used to observe the time required to complete the teaching materials and record the number of students involved in each meeting. The data obtained was analyzed by independent sample-t test and used the chart. The results of this study: SCT learning model based on exploration are more effective than cooperative learning models based on exploration in terms of the time required to complete teaching materials based on exploration and student engagement.

A population-based study of cognitive impairment in socially vulnerable adults in Argentina. The Matanza Riachuelo study preliminary results

PubMed Central

Bartoloni, Leonardo; Blatt, Graciela; Insua, Iván; Furman, Mariano; González, María Agustina; Hermann, Bárbara; Kesselman, Mariana; Massautis, Alicia; Reinado, Alejandra; Senas, Patricia; Yavitz, Claudia; Lejarraga, Horacio; Nunes, Fernando; Arizaga, Raúl Luciano; Allegri, Ricardo F

2014-01-01

Population aging has taken place intensively worldwide, even in developing countries. These countries have population groups with low resources and basic unmet needs that are frequently omitted from epidemiological studies. Objective The purpose of this study was to determine the prevalence of cognitive impairment (CI) and dementia in an economic and socially vulnerable population from Argentina. Methods A door-to-door observational population-based survey among adults over 60 years of cognitive impairment and dementia in the social vulnerable area of the Matanza Riachuelo Basin, in the suburban area of Buenos Aires, Argentina was conducted. Trained psychologists interviewed subjects and a proxy informant. A standardized protocol including a socio-demographic questionnaire, the Mini-Mental State Examination, the Geriatric Depression Scale and a functional inventory for IADL and ADL was administered. Diagnoses were divided into three general categories: normal cognitive function, cognitive impairment-no dementia (CIND) and dementia. Results and Conclusions A total of 2437 elderly persons were assessed, of which 73.6% fulfilled inclusion criteria. The prevalence of CI among those over 60 was 26.4% (18.1% CIND and 8.3% dementia) with higher prevalence of dementia in younger individuals than rates reported in developed counties, probably due to low control of vascular risk factors. This information can help inform health public decisions in the generation of programs and plans for the prevention, diagnosis and treatment of cognitive impairment in this type of socially vulnerable population. PMID:29213923

A population-based study of cognitive impairment in socially vulnerable adults in Argentina. The Matanza Riachuelo study preliminary results.

PubMed

Bartoloni, Leonardo; Blatt, Graciela; Insua, Iván; Furman, Mariano; González, María Agustina; Hermann, Bárbara; Kesselman, Mariana; Massautis, Alicia; Reinado, Alejandra; Senas, Patricia; Yavitz, Claudia; Lejarraga, Horacio; Nunes, Fernando; Arizaga, Raúl Luciano; Allegri, Ricardo F

2014-01-01

Population aging has taken place intensively worldwide, even in developing countries. These countries have population groups with low resources and basic unmet needs that are frequently omitted from epidemiological studies. The purpose of this study was to determine the prevalence of cognitive impairment (CI) and dementia in an economic and socially vulnerable population from Argentina. A door-to-door observational population-based survey among adults over 60 years of cognitive impairment and dementia in the social vulnerable area of the Matanza Riachuelo Basin, in the suburban area of Buenos Aires, Argentina was conducted. Trained psychologists interviewed subjects and a proxy informant. A standardized protocol including a socio-demographic questionnaire, the Mini-Mental State Examination, the Geriatric Depression Scale and a functional inventory for IADL and ADL was administered. Diagnoses were divided into three general categories: normal cognitive function, cognitive impairment-no dementia (CIND) and dementia. A total of 2437 elderly persons were assessed, of which 73.6% fulfilled inclusion criteria. The prevalence of CI among those over 60 was 26.4% (18.1% CIND and 8.3% dementia) with higher prevalence of dementia in younger individuals than rates reported in developed counties, probably due to low control of vascular risk factors. This information can help inform health public decisions in the generation of programs and plans for the prevention, diagnosis and treatment of cognitive impairment in this type of socially vulnerable population.

A study of the remarkable galaxy system AM 546-324 (the core of Abell S0546)

NASA Astrophysics Data System (ADS)

Faúndez-Abans, M.; Krabbe, A. C.; de Oliveira-Abans, M.; da Rocha-Poppe, P. C.; Rodrigues, I.; Fernandes-Martin, V. A.; Fernandes, I. F.

2012-07-01

Aims: We report first results of an investigation of the tidally disturbed galaxy system AM 546-324, whose two principal galaxies 2MFGC 04711 and AM 0546-324 (NED02) were previously classified as interacting doubles. This system was selected to study the interaction of ellipticals in a moderately dense environment. We provide spectral characteristics of the system and present an observational study of the interaction effects on the morphology, kinematics, and stellar population of these galaxies. Methods: The study is based on long-slit spectrophotometric data in the range of ~4500-8000 Å obtained with the Gemini Multi-Object Spetrograph at Gemini South (GMOS-S). We have used the stellar population synthesis code STARLIGHT to investigate the star formation history of these galaxies. The Gemini/GMOS-S direct r-G0303 broad band pointing image was used to enhance and study fine morphological structures. The main absorption lines in the spectra were used to determine the radial velocity. Results: Along the whole long-slit signal, the spectra of the Shadowy galaxy (discovered by us), 2MFGC 04711, and AM 0546-324 (NED02) resemble that of an early-type galaxy. We estimated redshifts of z = 0.0696, z = 0.0693 and z = 0.0718, corresponding to heliocentric velocities of 20 141 km s-1, 20 057 km s-1, and 20 754 km s-1 for the Shadowy galaxy, 2MFGC 04711 and AM 0546-324 (NED02), respectively. The central regions of 2MFGC 04711 and AM 0546-324 (NED02) are completely dominated by an old stellar population of 2 × 109 < t ≤ 13 × 109 yr and do not show any spatial variation in the contribution of the stellar-population components. Conclusions: The observed rotation profile distribution of 2MFGC 04711 and AM 0546-324 (NED02) can be adequately interpreted as an ongoing stage of interaction with the Shadowy galaxy as the center of the local gravitational potential-well of the system. The three galaxies are all early-type. The extended and smooth distribution of the material in the Shadowy galaxy is a good laboratory to study direct observational signatures of tidal friction in action. Based on observations made at the Gemini Observatory, under the identification number GS-2010B-Q-7.

Cancer incidence and nuclear facilities in Ukraine: a community-based study.

PubMed

Bazyka, D A; Prysyazhnyuk, A Ye; Romanenko, A Ye; Fedorenko, Z P; Gudzenko, N A; Fuzik, M M; Khukhrianska, O M; Trotsyuk, N K; Gulak, L O; Goroch, Ye L; Sumkina, Ye V

2012-07-01

The study goal was to investigate malignant tumors incidence in 5 Ukrainian cities with nuclear hazardous enterprises: extractive, processing enterprises of uranium ore (Zhovti Wody and Dniprodzerzhynsk of Dnipropetrovsk region) and nuclear power stations (Energodar of Zaporizhska region, Pivdennoukrainsk of Mykolayivska region, Netishyn of Khmelnytska region). average annual population of the cities under study in 2003-2008 was 439 600 persons. Total and specific cancer incidence was investigated. Site specific incidence was analyzed for malignancies proved to be radiosensitive in previous studies: trachea, bronchus and lung, breast, kidney, thyroid cancer and leukemia. Data on cancer cases were received in National Cancer Registry of Ukraine (National Cancer Institute). There was used the data of the State Statistics Committee of Ukraine on the size of the studied population by gender - age groups. Standardized incidence ratio of cancer at a whole and for each of five specific forms of malignancies were calculated for the population of each city and group of cities depending on the nature of industrial activity. During the observed period there were registered 9 381 cancer cases in inhabitants of Ukrainian cities with radiation hazardous facilities. There was stated that cancer incidence rate in population of 5 cities significantly exceeded national and regional levels. Among specific forms of malignancy there were observed excess of lung, trachea, bronchus, breast, kidney cancer and leukemia in population of extractive, processing uranium ore cities. No excess of thyroid cancer was identified. In cities with nuclear power station there were registered excess of kidney cancer. Results of the study suggest the necessity to explore the role of various factors in forming the identified cancer incidence features in the Ukrainian population living near the nuclear power facilities.

Models of Eucalypt phenology predict bat population flux.

PubMed

Giles, John R; Plowright, Raina K; Eby, Peggy; Peel, Alison J; McCallum, Hamish

2016-10-01

Fruit bats (Pteropodidae) have received increased attention after the recent emergence of notable viral pathogens of bat origin. Their vagility hinders data collection on abundance and distribution, which constrains modeling efforts and our understanding of bat ecology, viral dynamics, and spillover. We addressed this knowledge gap with models and data on the occurrence and abundance of nectarivorous fruit bat populations at 3 day roosts in southeast Queensland. We used environmental drivers of nectar production as predictors and explored relationships between bat abundance and virus spillover. Specifically, we developed several novel modeling tools motivated by complexities of fruit bat foraging ecology, including: (1) a dataset of spatial variables comprising Eucalypt-focused vegetation indices, cumulative precipitation, and temperature anomaly; (2) an algorithm that associated bat population response with spatial covariates in a spatially and temporally relevant way given our current understanding of bat foraging behavior; and (3) a thorough statistical learning approach to finding optimal covariate combinations. We identified covariates that classify fruit bat occupancy at each of our three study roosts with 86-93% accuracy. Negative binomial models explained 43-53% of the variation in observed abundance across roosts. Our models suggest that spatiotemporal heterogeneity in Eucalypt-based food resources could drive at least 50% of bat population behavior at the landscape scale. We found that 13 spillover events were observed within the foraging range of our study roosts, and they occurred during times when models predicted low population abundance. Our results suggest that, in southeast Queensland, spillover may not be driven by large aggregations of fruit bats attracted by nectar-based resources, but rather by behavior of smaller resident subpopulations. Our models and data integrated remote sensing and statistical learning to make inferences on bat ecology and disease dynamics. This work provides a foundation for further studies on landscape-scale population movement and spatiotemporal disease dynamics.

Several Different Lactase Persistence Associated Alleles and High Diversity of the Lactase Gene in the Admixed Brazilian Population

PubMed Central

Friedrich, Deise C.; Santos, Sidney E. B.; Ribeiro-dos-Santos, Ândrea K. C.; Hutz, Mara H.

2012-01-01

Adult-type hypolactasia is a common phenotype caused by the lactase enzyme deficiency. The −13910 C>T polymorphism, located 14 Kb upstream of the lactase gene (LCT) in the MCM6 gene was associated with lactase persistence (LP) in Europeans. This polymorphism is rare in Africa but several other variants associated with lactase persistence were observed in Africans. The aims of this study were to identify polymorphisms in the MCM6 region associated with the lactase persistence phenotype and to determine the distribution of LCT gene haplotypes in 981 individuals from North, Northeast and South Brazil. These polymorphisms were genotyped by PCR based methods and sequencing. The −13779*C,−13910*T, −13937*A, −14010*C, −14011*T LP alleles previously described in the MCM6 gene region that acts as an enhancer for the LCT gene were identified in Brazilians. The most common LP allele was −13910*T. Its frequency was highly correlated with European ancestry in the Brazilian populations investigated. The −13910*T was higher (0.295) in southern Brazilians of European ancestry and lower (0.175) in the Northern admixed population. LCT haplotypes were derived from the 10 LCT SNPs genotyped. Overall twenty six haplotypes previously described were identified in the four Brazilian populations studied. The Multidimensional Scaling analysis showed that Belém, in the north, was closer to Amerindians. Northeastern and southern Afro-descendants were more related with Bantu-speaking South Africans whereas the Southern population with European ancestry grouped with Southern and Northern Europeans. This study shows a high variability considering the number of LCT haplotypes observed. Due to the highly admixed nature of the Brazilian populations, the diagnosis of hypolactasia in Brazil, based only in the investigation of the −13910*T allele is an oversimplification. PMID:23029545

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

Regional differences in echocardiography provision in New Zealand--results from the 2013 SCANZ Workforce Survey.

PubMed

Buckley, Belinda A; Poppe, Katrina; Farnworth, Mark J; Whalley, Gillian

2015-01-30

Abstract Healthcare may be unevenly distributed based on geographic location. This study aimed to identify whether regional differences in echocardiography provision exist and, if so, to explore key causes. In March 2013, 18 public hospitals with a sonographer-led echocardiography service were surveyed, all of which provided data. Questions related to characteristics of the sonographer workforce, echocardiogram volumes and workflows. Information on District Health Board (DHB) population was obtained from public access websites. Multivariable linear regression was performed using the following variables: ethnicity, age, socioeconomic status, type of centre, sonographer full-time equivalent (FTE) and number/proportion of trainees to determine their potential contribution to echocardiogram volume. 1748 echocardiograms were performed per 100,000 population (mean) with significant differences seen amongst DHBs but not between tertiary surgical and regional centres (surgical median 1802, regional median 1658, p=0.18). Regional disparity in the population-based cardiac sonographer workforce size was observed and the number of scans performed per sonographer was higher in larger centres. In multivariable modelling, the DHB population-based scan volume was predicted by: socioeconomic status (top two quintiles of deprivation status increased scans by 75 per 100,000 population, p=0.02) and age (age 20 to 65 years increased scans by 131 per 100,000 population, p=0.06). Regional differences in echocardiography services in New Zealand exist as evidenced by marked regional disparity in both population-based echo volumes and cardiac sonographer workforce size.

The effects of adding group-based lifestyle counselling to individual counselling on changes in plasma glucose levels in a randomized controlled trial: the Inter99 study.

PubMed

Lau, C; Vistisen, D; Toft, U; Tetens, I; Glümer, C; Pedersen, O; Jørgensen, T; Borch-Johnsen, K

2011-12-01

This study aimed to assess whether group-based lifestyle counselling offered to a high-risk population subgroup had any effect beyond individual multifactorial interventions on fasting plasma glucose (FPG) and 2-h plasma glucose (2hPG) changes. In a population-based study of 6784 participants, 4053 were determined to be at high risk based on a risk estimate of ischaemic heart disease or the presence of risk factors (smoking, hypertension, hypercholesterolaemia, obesity, impaired glucose tolerance). Of these subjects, 90% were randomized to high-intensity intervention (group A) and 10% to low-intensity intervention (group B). All participants went through health examinations, risk assessments and individual lifestyle counselling. Participants in group A were further offered group-based lifestyle counselling. The intervention was repeated after 1 and 3 years. A total of 2738 participants free of diabetes at baseline (1999-2001) and with at least one FPG and/or 2hPG measurement during 5 years of follow-up were included in the analyses. Differences in changes of plasma glucose between groups A and B were analyzed using multilevel linear regression. For FPG, crude 5-year changes were significantly different between the two groups (group A: -0.003 mmol/L vs group B: -0.079 mmol/L; P=0.0427). After adjusting for relevant confounders, no differences in FPG changes were observed (P=0.116). Also, no significant differences in the 5-year changes in 2hPG between the two groups were observed (group A: - 0.127 mmol/L vs group B: -0.201 mmol/L; P=0.546). Offering additional group-based intervention to a high-risk population subgroup had no clinical effects on changes in plasma glucose beyond those of individualized multifactorial interventions. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Does childhood cancer affect parental divorce rates? A population-based study.

PubMed

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.

Raw garlic consumption as a protective factor for lung cancer, a population-based case-control study in a Chinese population

PubMed Central

Jin, Zi-Yi; Wu, Ming; Han, Ren-Qiang; Zhang, Xiao-Feng; Wang, Xu-Shan; Liu, Ai-Ming; Zhou, Jin-Yi; Lu, Qing-Yi; Zhang, Zuo-Feng; Zhao, Jin-Kou

2013-01-01

Protective effect of garlic on the development of cancer has been reported in vitro and in vivo experimental studies, however, few human epidemiological studies have evaluated the relationship. A population-based case-control study has been conducted in a Chinese population from 2003 to 2010, with the aim to explore the association between raw garlic consumption and lung cancer. Epidemiological data were collected by face-to-face interviews using a standard questionnaire among 1,424 lung cancer cases and 4,543 healthy controls. Unconditional logistic regression was employed to estimate adjusted odds ratios (OR) and their 95% confidence intervals (CIs), and to evaluate ratio of odds ratios (ROR) for multiplicative interactions between raw garlic consumption and other risk factors. After adjusting for potential confounding factors, raw garlic consumption of ≥ 2 times per week is inversely associated with lung cancer (OR = 0.56, 95% CI = 0.44-0.72) with a monotonic dose-response relationship (p for trend <0.001). Furthermore, strong interactions at either additive and/or multiplicative scales were observed between raw garlic consumption and tobacco smoking (Synergy Index (SI) = 0.70, 95% CI = 0.57-0.85; and ROR = 0.78, 95% CI = 0.67-0.90), as well as high-temperature cooking oil fume (ROR = 0.77, 95% CI = 0.59-1.00). In conclusion, protective association between intake of raw garlic and lung cancer has been observed with a dose-response pattern, suggesting that garlic may potentially serve as a chemopreventive agent for lung cancer. Effective components in garlic in lung cancer chemoprevention warrant further in-depth investigation. PMID:23658367

Quantifying Population-Level Risks Using an Individual-Based Model: Sea Otters, Harlequin Ducks, and the Exxon Valdez Oil Spill

PubMed Central

Harwell, Mark A; Gentile, John H; Parker, Keith R

2012-01-01

Ecological risk assessments need to advance beyond evaluating risks to individuals that are largely based on toxicity studies conducted on a few species under laboratory conditions, to assessing population-level risks to the environment, including considerations of variability and uncertainty. Two individual-based models (IBMs), recently developed to assess current risks to sea otters and seaducks in Prince William Sound more than 2 decades after the Exxon Valdez oil spill (EVOS), are used to explore population-level risks. In each case, the models had previously shown that there were essentially no remaining risks to individuals from polycyclic aromatic hydrocarbons (PAHs) derived from the EVOS. New sensitivity analyses are reported here in which hypothetical environmental exposures to PAHs were heuristically increased until assimilated doses reached toxicity reference values (TRVs) derived at the no-observed-adverse-effects and lowest-observed-adverse-effects levels (NOAEL and LOAEL, respectively). For the sea otters, this was accomplished by artificially increasing the number of sea otter pits that would intersect remaining patches of subsurface oil residues by orders of magnitude over actual estimated rates. Similarly, in the seaduck assessment, the PAH concentrations in the constituents of diet, sediments, and seawater were increased in proportion to their relative contributions to the assimilated doses by orders of magnitude over measured environmental concentrations, to reach the NOAEL and LOAEL thresholds. The stochastic IBMs simulated millions of individuals. From these outputs, frequency distributions were derived of assimilated doses for populations of 500 000 sea otters or seaducks in each of 7 or 8 classes, respectively. Doses to several selected quantiles were analyzed, ranging from the 1-in-1000th most-exposed individuals (99.9% quantile) to the median-exposed individuals (50% quantile). The resulting families of quantile curves provide the basis for characterizing the environmental thresholds below which no population-level effects could be detected and above which population-level effects would be expected to become manifest. This approach provides risk managers an enhanced understanding of the risks to populations under various conditions and assumptions, whether under hypothetically increased exposure regimes, as demonstrated here, or in situations in which actual exposures are near toxic effects levels. This study shows that individual-based models are especially amenable and appropriate for conducting population-level risk assessments, and that they can readily be used to answer questions about the risks to individuals and populations across a variety of exposure conditions. Integr Environ Assess Manag 2012; 8: 503–522. © 2012 SETAC PMID:22275071

Quantifying population-level risks using an individual-based model: sea otters, Harlequin Ducks, and the Exxon Valdez oil spill.

PubMed

Harwell, Mark A; Gentile, John H; Parker, Keith R

2012-07-01

Ecological risk assessments need to advance beyond evaluating risks to individuals that are largely based on toxicity studies conducted on a few species under laboratory conditions, to assessing population-level risks to the environment, including considerations of variability and uncertainty. Two individual-based models (IBMs), recently developed to assess current risks to sea otters and seaducks in Prince William Sound more than 2 decades after the Exxon Valdez oil spill (EVOS), are used to explore population-level risks. In each case, the models had previously shown that there were essentially no remaining risks to individuals from polycyclic aromatic hydrocarbons (PAHs) derived from the EVOS. New sensitivity analyses are reported here in which hypothetical environmental exposures to PAHs were heuristically increased until assimilated doses reached toxicity reference values (TRVs) derived at the no-observed-adverse-effects and lowest-observed-adverse-effects levels (NOAEL and LOAEL, respectively). For the sea otters, this was accomplished by artificially increasing the number of sea otter pits that would intersect remaining patches of subsurface oil residues by orders of magnitude over actual estimated rates. Similarly, in the seaduck assessment, the PAH concentrations in the constituents of diet, sediments, and seawater were increased in proportion to their relative contributions to the assimilated doses by orders of magnitude over measured environmental concentrations, to reach the NOAEL and LOAEL thresholds. The stochastic IBMs simulated millions of individuals. From these outputs, frequency distributions were derived of assimilated doses for populations of 500,000 sea otters or seaducks in each of 7 or 8 classes, respectively. Doses to several selected quantiles were analyzed, ranging from the 1-in-1000th most-exposed individuals (99.9% quantile) to the median-exposed individuals (50% quantile). The resulting families of quantile curves provide the basis for characterizing the environmental thresholds below which no population-level effects could be detected and above which population-level effects would be expected to become manifest. This approach provides risk managers an enhanced understanding of the risks to populations under various conditions and assumptions, whether under hypothetically increased exposure regimes, as demonstrated here, or in situations in which actual exposures are near toxic effects levels. This study shows that individual-based models are especially amenable and appropriate for conducting population-level risk assessments, and that they can readily be used to answer questions about the risks to individuals and populations across a variety of exposure conditions. Copyright © 2012 SETAC.

Variation of genetic diversity in a rapidly expanding population of the greater long-tailed hamster (Tscherskia triton) as revealed by microsatellites.

PubMed

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.

Modeling the effects of trophy selection and environmental disturbance on a simulated population of African lions.

PubMed

Whitman, Karyl L; Starfield, Anthony M; Quadling, Henley; Packer, Craig

2007-06-01

Tanzania is a premier destination for trophy hunting of African lions (Panthera leo) and is home to the most extensive long-term study of unhunted lions. Thus, it provides a unique opportunity to apply data from a long-term field study to a conservation dilemma: How can a trophy-hunted species whose reproductive success is closely tied to social stability be harvested sustainably? We used an individually based, spatially explicit, stochastic model, parameterized with nearly 40 years of behavioral and demographic data on lions in the Serengeti, to examine the separate effects of trophy selection and environmental disturbance on the viability of a simulated lion population in response to annual harvesting. Female population size was sensitive to the harvesting of young males (> or = 3 years), whereas hunting represented a relatively trivial threat to population viability when the harvest was restricted to mature males (> or = 6 years). Overall model performance was robust to environmental disturbance and to errors in age assessment based on nose coloration as an index used to age potential trophies. Introducing an environmental disturbance did not eliminate the capacity to maintain a viable breeding population when harvesting only older males, and initially depleted populations recovered within 15-25 years after the disturbance to levels comparable to hunted populations that did not experience a catastrophic event. These results are consistent with empirical observations of lion resilience to environmental stochasticity.

[Radio and microwave frequency radiation and health--an analysis of the literature].

PubMed

Röösli, M; Rapp, R; Braun-Fahrländer, C

2003-06-01

This paper gives an overview of present scientific knowledge in health research on the effects from radio and microwave frequency radiation, at levels to which the general population is typically exposed. The review is based on human experimental and epidemiological studies investigating the effects of radiation in the frequency range between 100 kHz and 10 GHz. The relevant studies were identified via systematic searches of the databases Medline and ISI Web of Science. The review concludes that the existing scientific knowledge base is too limited to draw final conclusions on the health risk from exposure in the low-dose range. Only few studies have investigated the effect of long-term exposure on the general population in the normal environment. Accordingly, little can be predicted regarding long-term health risks. Various studies observed an increased risk for tumours in the hematopoietic and lymphatic tissue of people living in the proximity of TV and radio broadcast transmitters. However, methodological limitations to these studies have been identified and their findings are controversial. In studies of a possible association between brain tumours and mobile phone use, the average period mobile phones use was short compared to the known latency period of brain tumours. Although these studies did not establish an overall increased risk of brain tumours associated with mobile phone use, there were some indications of an association. Immediate effects associated with mobile phone use have been observed in human experimental studies that cannot be explained by conventional thermal mechanisms. The observed effects are within the normal physiological range and are therefore hard to interpret with respect to an increased risk to health. However, it can be concluded that mechanisms other than the established thermal mechanisms exist. Because of the present fragmentary scientific database, a precautionary approach when dealing with radio and microwave frequency radiation is recommended for the individual and the general population.

The rationale/design of the Guimarães/Vizela study: a multimodal population-based cohort study to determine global cardiovascular risk and disease.

PubMed

Cunha, Pedro Guimarães; Cotter, Jorge; Oliveira, Pedro; Vila, Isabel; Sousa, Nuno

2014-06-01

Cardiovascular disease and dementia are growing medical and social problems in aging societies. Appropriate knowledge of cardiovascular disease and cognitive decline risk factors (RFs) are critical for global CVR health preventive intervention. Many epidemiological studies use case definition based on data collected/measured in a single visit, a fact that can overestimate prevalence rates and distant from clinical practice demanding criteria. Portugal displays an elevated stroke mortality rate. However, population's global CV risk characterization is limited, namely, considering traditional/nontraditional RF and new intermediate phenotypes of CV and renal disease. Association of hemodynamic variables (pulse wave velocity and central blood pressure) with global CVR stratification, cognitive performance, and kidney disease are practically inexistent at a dwelling population level. After reviewing published data, we designed a population-based cohort study to analyze the prevalence of these cardiovascular RFs and intermediate phenotypes, using random sampling of adult dwellers living in 2 adjacent cities. Strict definition of phenotypes was planned: subjects were observed twice, and several hemodynamic and other biological variables measured at least 3 months apart. Three thousand thirty-eight subjects were enrolled, and extensive data collection (including central and peripheral blood pressure, pulse wave velocity), sample processing, and biobank edification were carried out. One thousand forty-seven cognitive evaluations were performed. Seeking for CV risk reclassification, early identification of subjects at risk, and evidence of early vascular aging and cognitive and renal function decline, using the strict daily clinical practice criteria, will lead to better resource allocation in preventive measures at a population level.

A sampling design and model for estimating abundance of Nile crocodiles while accounting for heterogeneity of detectability of multiple observers

USGS Publications Warehouse

Shirley, Matthew H.; Dorazio, Robert M.; Abassery, Ekramy; Elhady, Amr A.; Mekki, Mohammed S.; Asran, Hosni H.

2012-01-01

As part of the development of a management program for Nile crocodiles in Lake Nasser, Egypt, we used a dependent double-observer sampling protocol with multiple observers to compute estimates of population size. To analyze the data, we developed a hierarchical model that allowed us to assess variation in detection probabilities among observers and survey dates, as well as account for variation in crocodile abundance among sites and habitats. We conducted surveys from July 2008-June 2009 in 15 areas of Lake Nasser that were representative of 3 main habitat categories. During these surveys, we sampled 1,086 km of lake shore wherein we detected 386 crocodiles. Analysis of the data revealed significant variability in both inter- and intra-observer detection probabilities. Our raw encounter rate was 0.355 crocodiles/km. When we accounted for observer effects and habitat, we estimated a surface population abundance of 2,581 (2,239-2,987, 95% credible intervals) crocodiles in Lake Nasser. Our results underscore the importance of well-trained, experienced monitoring personnel in order to decrease heterogeneity in intra-observer detection probability and to better detect changes in the population based on survey indices. This study will assist the Egyptian government establish a monitoring program as an integral part of future crocodile harvest activities in Lake Nasser

The Effects of Cannabis Among Adults With Chronic Pain and an Overview of General Harms: A Systematic Review.

PubMed

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).

Do we need demographic data to forecast plant population dynamics?

USGS Publications Warehouse

Tredennick, Andrew T.; Hooten, Mevin B.; Adler, Peter B.

2017-01-01

Rapid environmental change has generated growing interest in forecasts of future population trajectories. Traditional population models built with detailed demographic observations from one study site can address the impacts of environmental change at particular locations, but are difficult to scale up to the landscape and regional scales relevant to management decisions. An alternative is to build models using population-level data that are much easier to collect over broad spatial scales than individual-level data. However, it is unknown whether models built using population-level data adequately capture the effects of density-dependence and environmental forcing that are necessary to generate skillful forecasts.Here, we test the consequences of aggregating individual responses when forecasting the population states (percent cover) and trajectories of four perennial grass species in a semi-arid grassland in Montana, USA. We parameterized two population models for each species, one based on individual-level data (survival, growth and recruitment) and one on population-level data (percent cover), and compared their forecasting accuracy and forecast horizons with and without the inclusion of climate covariates. For both models, we used Bayesian ridge regression to weight the influence of climate covariates for optimal prediction.In the absence of climate effects, we found no significant difference between the forecast accuracy of models based on individual-level data and models based on population-level data. Climate effects were weak, but increased forecast accuracy for two species. Increases in accuracy with climate covariates were similar between model types.In our case study, percent cover models generated forecasts as accurate as those from a demographic model. For the goal of forecasting, models based on aggregated individual-level data may offer a practical alternative to data-intensive demographic models. Long time series of percent cover data already exist for many plant species. Modelers should exploit these data to predict the impacts of environmental change.

Regression-Based Estimates of Observed Functional Status in Centenarians

PubMed Central

Mitchell, Meghan B.; Miller, L. Stephen; Woodard, John L.; Davey, Adam; Martin, Peter; Burgess, Molly; Poon, Leonard W.

2011-01-01

Purpose of the Study: There is lack of consensus on the best method of functional assessment, and there is a paucity of studies on daily functioning in centenarians. We sought to compare associations between performance-based, self-report, and proxy report of functional status in centenarians. We expected the strongest relationships between proxy reports and observed performance of basic activities of daily living (BADLs) and instrumental activities of daily living (IADLs). We hypothesized that the discrepancy between self-report and observed daily functioning would be modified by cognitive status. We additionally sought to provide clinicians with estimates of centenarians’ observed daily functioning based on their mental status in combination with subjective measures of activities of daily living (ADLs). Design and Methods: Two hundred and forty-four centenarians from the Georgia Centenarian Study were included in this cross-sectional population-based study. Measures included the Direct Assessment of Functional Status, self-report and proxy report of functional status, and the Mini-Mental State Examination (MMSE). Results: Associations between observed and proxy reports were stronger than between observed and self-report across BADL and IADL measures. A significant MMSE by type of report interaction was found, indicating that lower MMSE performance is associated with a greater discrepancy between subjective and objective ADL measures. Implications: Results demonstrate associations between 3 methods of assessing functional status and suggest proxy reports are generally more accurate than self-report measures. Cognitive status accounted for some of the discrepancy between observed and self-reports, and we provide clinicians with tables to estimate centenarians’ performance on observed functional measures based on MMSE and subjective report of functional status. PMID:20974657

Suicide Risk Assessment and Prevention: A Systematic Review Focusing on Veterans.

PubMed

Nelson, Heidi D; Denneson, Lauren M; Low, Allison R; Bauer, Brian W; O'Neil, Maya; Kansagara, Devan; Teo, Alan R

2017-10-01

Suicide rates in veteran and military populations in the United States are high. This article reviews studies of the accuracy of methods to identify individuals at increased risk of suicide and the effectiveness and adverse effects of health care interventions relevant to U.S. veteran and military populations in reducing suicide and suicide attempts. Trials, observational studies, and systematic reviews relevant to U.S. veterans and military personnel were identified in searches of MEDLINE, PsycINFO, SocINDEX, and Cochrane databases (January 1, 2008, to September 11, 2015), on Web sites, and in reference lists. Investigators extracted and confirmed data and dual-rated risk of bias for included studies. Nineteen studies evaluated accuracy of risk assessment methods, including models using retrospective electronic records data and clinician- or patient-rated instruments. Most methods demonstrated sensitivity ≥80% or area-under-the-curve values ≥.70 in single studies, including two studies based on electronic records of veterans and military personnel, but specificity varied. Suicide rates were reduced in six of eight observational studies of population-level interventions. Only two of ten trials of individual-level psychotherapy reported statistically significant differences between treatment and usual care. Risk assessment methods have been shown to be sensitive predictors of suicide and suicide attempts, but the frequency of false positives limits their clinical utility. Research to refine these methods and examine clinical applications is needed. Studies of suicide prevention interventions are inconclusive; trials of population-level interventions and promising therapies are required to support their clinical use.

A case-control study: occupational cooking and the risk of uveal melanoma

PubMed Central

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

On the use of satellite-based estimates of rainfall temporal distribution to simulate the potential for malaria transmission in rural Africa

NASA Astrophysics Data System (ADS)

Yamana, Teresa K.; Eltahir, Elfatih A. B.

2011-02-01

This paper describes the use of satellite-based estimates of rainfall to force the Hydrology, Entomology and Malaria Transmission Simulator (HYDREMATS), a hydrology-based mechanistic model of malaria transmission. We first examined the temporal resolution of rainfall input required by HYDREMATS. Simulations conducted over Banizoumbou village in Niger showed that for reasonably accurate simulation of mosquito populations, the model requires rainfall data with at least 1 h resolution. We then investigated whether HYDREMATS could be effectively forced by satellite-based estimates of rainfall instead of ground-based observations. The Climate Prediction Center morphing technique (CMORPH) precipitation estimates distributed by the National Oceanic and Atmospheric Administration are available at a 30 min temporal resolution and 8 km spatial resolution. We compared mosquito populations simulated by HYDREMATS when the model is forced by adjusted CMORPH estimates and by ground observations. The results demonstrate that adjusted rainfall estimates from satellites can be used with a mechanistic model to accurately simulate the dynamics of mosquito populations.

Educators' Reports on Incidence of Harassment and Advocacy toward LGBTQ Students

ERIC Educational Resources Information Center

Dragowski, Eliza A.; McCabe, Paul C.; Rubinson, Florence

2016-01-01

This study is based on a national survey investigation of 968 educators, who reported the incidence of LGBTQ harassment in schools, and their advocacy efforts on behalf of this population. LGBTQ-related knowledge, attitudes, norms, and perceived ability to advocate were also assessed. Ninety percent of educators reported observing LGBTQ harassment…

The association between vitamin B12, albuminuria and reduced kidney function: an observational cohort study

USDA-ARS?s Scientific Manuscript database

Background: Variants in CUBN, the gene encoding cubilin, a proximal tubular transport protein, have been associated with albuminuria and vitamin B12 (B12) deficiency. We hypothesized that low levels of B12 would be associated with albuminuria in a population-based cohort. Methods: We analyzed parti...

Effect of aircraft noise on the equilibrium of airport residents: Longitudinal study around Roissy, phase 3

NASA Technical Reports Server (NTRS)

Francois, J.

1981-01-01

The effects of airplane noise on the mental equilibrium of residents living near airports are discussed, and based on population sample surveys involving health questionnaires and self-administered personality tests. Progressive changes were observed on the part of residents living near a large airport.

Cancer in the Sami population of North Norway, 1970-1997.

PubMed

Haldorsen, T; Tynes, T

2005-02-01

The Sami population in North Norway constitutes an ethnic minority with a lifestyle that diverges from that of the rest of the population. A cohort of 19 801 people of Sami origin was followed for cancer incidence over the period 1970-1997 by the Norwegian Cancer Registry. Among the Sami 1340 cases of cancer were observed versus 1658.2 expected, based on a regional reference population. For both sexes a significantly decreased incidence of colon cancer was observed. The standardized incidence ratio (SIR) for men was 0.50 (95% confidence interval (CI) 0.34-0.71) and for women 0.62 (95% CI 0.43-0.85). Low SIRs were observed for lung cancer: 0.63 (95% CI 0.51-0.77) and 0.60 (95% CI 0.37-0.91), for men and women, respectively. Men of Sami ancestry had a decreased risk of prostate cancer: SIR 0.57 (95% CI 0.45-0.71). Among women 127 cases of breast cancer were observed versus 149.6 expected. A relatively high physical activity and a diet rich in fish may in part explain the low cancer incidence. Some Sami were exposed to radioactivity as a result of their diet based on reindeer products. Adverse effects on their cancer incidence were not observed.

Uniform Temperature Dependency in the Phenology of a Keystone Herbivore in Lakes of the Northern Hemisphere

PubMed Central

Straile, Dietmar; Adrian, Rita; Schindler, Daniel E.

2012-01-01

Spring phenologies are advancing in many ecosystems associated with climate warming causing unpredictable changes in ecosystem functioning. Here we establish a phenological model for Daphnia, an aquatic keystone herbivore based on decadal data on water temperatures and the timing of Daphnia population maxima from Lake Constance, a large European lake. We tested this model with long-term time-series data from two lakes (Müggelsee, Germany; Lake Washington, USA), and with observations from a diverse set of 49 lakes/sites distributed widely across the Northern Hemisphere (NH). The model successfully captured the observed temporal variation of Daphnia phenology in the two case study sites (r2 = 0.25 and 0.39 for Müggelsee and Lake Washington, respectively) and large-scale spatial variation in the NH (R2 = 0.57). These results suggest that Daphnia phenology follows a uniform temperature dependency in NH lakes. Our approach – based on temperature phenologies – has large potential to study and predict phenologies of animal and plant populations across large latitudinal gradients in other ecosystems. PMID:23071520

Quantitating and Dating Recent Gene Flow between European and East Asian Populations

PubMed Central

Qin, Pengfei; Zhou, Ying; Lou, Haiyi; Lu, Dongsheng; Yang, Xiong; Wang, Yuchen; Jin, Li; Chung, Yeun-Jun; Xu, Shuhua

2015-01-01

Historical records indicate that extensive cultural, commercial and technological interaction occurred between European and Asian populations. What have been the biological consequences of these contacts in terms of gene flow? We systematically estimated gene flow between Eurasian groups using genome-wide polymorphisms from 34 populations representing Europeans, East Asians, and Central/South Asians. We identified recent gene flow between Europeans and Asians in most populations we studied, including East Asians and Northwestern Europeans, which are normally considered to be non-admixed populations. In addition we quantitatively estimated the extent of this gene flow using two statistical approaches, and dated admixture events based on admixture linkage disequilibrium. Our results indicate that most genetic admixtures occurred between 2,400 and 310 years ago and show the admixture proportions to be highly correlated with geographic locations, with the highest admixture proportions observed in Central Asia and the lowest in East Asia and Northwestern Europe. Interestingly, we observed a North-to-South decline of European gene flow in East Asians, suggesting a northern path of European gene flow diffusing into East Asian populations. Our findings contribute to an improved understanding of the history of human migration and the evolutionary mechanisms that have shaped the genetic structure of populations in Eurasia. PMID:25833680

The Association of Hot Red Chili Pepper Consumption and Mortality: A Large Population-Based Cohort Study

PubMed Central

Chopan, Mustafa

2017-01-01

The evidence base for the health effects of spice consumption is insufficient, with only one large population-based study and no reports from Europe or North America. Our objective was to analyze the association between consumption of hot red chili peppers and mortality, using a population-based prospective cohort from the National Health and Nutritional Examination Survey (NHANES) III, a representative sample of US noninstitutionalized adults, in which participants were surveyed from 1988 to 1994. The frequency of hot red chili pepper consumption was measured in 16,179 participants at least 18 years of age. Total and cause-specific mortality were the main outcome measures. During 273,877 person-years of follow-up (median 18.9 years), a total of 4,946 deaths were observed. Total mortality for participants who consumed hot red chili peppers was 21.6% compared to 33.6% for those who did not (absolute risk reduction of 12%; relative risk of 0.64). Adjusted for demographic, lifestyle, and clinical characteristics, the hazard ratio was 0.87 (P = 0.01; 95% Confidence Interval 0.77, 0.97). Consumption of hot red chili peppers was associated with a 13% reduction in the instantaneous hazard of death. Similar, but statistically nonsignificant trends were seen for deaths from vascular disease, but not from other causes. In this large population-based prospective study, the consumption of hot red chili pepper was associated with reduced mortality. Hot red chili peppers may be a beneficial component of the diet. PMID:28068423

Identification of vertebral deformities in the Polish population by morphometric X-ray absorptiometry - results of the EPOLOS study.

PubMed

Skowrońska-Jóźwiak, Elzbieta; Płudowski, Paweł; Karczmarewicz, Elzbieta; Lorenc, Roman; Lewiński, Andrzej

2009-01-01

The aim of the study was the determination of the prevalence of asymptomatic vertebral deformities in healthy persons of the Polish population, based on morphometric X-ray absorptiometry (MXA), and comparison of the results with data from literature, obtained by other techniques. The study involved 829 persons, including 520 women and 309 men, aged 18-79 years, untreated for osteoporosis before. The Th(4) to L(4) vertebrae were examined. Lateral scans of the thoracic-lumbar spine were made by an Expert-XL densitometer. Six point digitization was used to calculate the anterior (Ha), central (Hc), and posterior (Hp) height of the Th(4)-L(4) vertebral bodies. The vertebrae were defined as having prevalent deformities when at least one ratio value (Ha/Hp, Hc/Hp, Hp/Hp up, or Hp/Hp low) fell 3 SDs below or even more than the reference mean of that ratio at any vertebral level. The analysis was performed on 9629 vertebrae, of which 167 (1.75%), evaluated as deformed and considered as fractures, were observed in 113 patients (13.63 % of the examined patients). In 81 persons (74% of the patients with fractures; 9.7% of the studied population), single fractures were demonstrated, while in 28 persons, multiple deformities prevailed. Fractures occurred in 108 women (20.7% of the examined women) and 42 men (13.5% of the examined men). The highest incidence of deformities was observed in women over 55 years of age. First-degree deformities dominated. Deformities of the Th(8) and Th(6) vertebrae were most frequently observed. 1. Using MXA, it was found that in the Polish population deformities of vertebrae are common, as was demonstrated in X-ray morphometric studies in the European Vertebral Observation Study (EVOS). 2. Densitometric morphometry, as a non-invasive technique, may become a useful tool in the diagnostics of vertebral fractures.

Star Formation Histories of Local Group Dwarf Galaxies. (Ludwig Biermann Award Lecture 1996)

NASA Astrophysics Data System (ADS)

Grebel, E. K.

The star formation histories of dwarf galaxies in the Local Group are reviewed. First the question of Local Group membership is considered based on various criteria. The properties of 31 (36) galaxies are consistent with likely (potential) Local Group membership. To study the star formation histories of these galaxies, a multi-parameter problem needs to be solved: Ages, metallicities, population fractions, and spatial variations must be determined, which depend crucially on the knowledge of reddening and distance. The basic methods for studying resolvable stellar populations are summarized. One method is demonstrated using the Fornax dwarf spheroidal galaxy. A comprehensive compilation of the star formation histories of dwarf irregulars, dwarf ellipticals, and dwarf spheroidals in the Local Group is presented and visualized through Hodge's population boxes. All galaxies appear to have differing fractions of old and intermediate-age populations, and those sufficiently massive and undisturbed to retain and recycle their gas are still forming stars today. Star formation has occurred either in distinct episodes or continuously over long periods of time. Metallicities and enrichment vary widely. Constraints on merger and remnant scenarios are discussed, and a unified picture based on the current knowledge is presented. Primary goals for future observations are: accurate age determinations based on turnoff photometry, detection of subpopulations distinct in age, metallicity, and/or spatial distribution; improved distances; and astrometric studies to derive orbits and constrain past and future interactions.

Preeminence of Staphylococcus aureus in infective endocarditis: a 1-year population-based survey.

PubMed

Selton-Suty, Christine; Célard, Marie; Le Moing, Vincent; Doco-Lecompte, Thanh; Chirouze, Catherine; Iung, Bernard; Strady, Christophe; Revest, Matthieu; Vandenesch, François; Bouvet, Anne; Delahaye, François; Alla, François; Duval, Xavier; Hoen, Bruno

2012-05-01

Observational studies showed that the profile of infective endocarditis (IE) significantly changed over the past decades. However, most studies involved referral centers. We conducted a population-based study to control for this referral bias. The objective was to update the description of characteristics of IE in France and to compare the profile of community-acquired versus healthcare-associated IE. A prospective population-based observational study conducted in all medical facilities from 7 French regions (32% of French individuals aged ≥18 years) identified 497 adults with Duke-Li-definite IE who were first admitted to the hospital in 2008. Main measures included age-standardized and sex-standardized incidence of IE and multivariate Cox regression analysis for risk factors of in-hospital death. The age-standardized and sex-standardized annual incidence of IE was 33.8 (95% confidence interval [CI], 30.8-36.9) cases per million inhabitants. The incidence was highest in men aged 75-79 years. A majority of patients had no previously known heart disease. Staphylococci were the most common causal agents, accounting for 36.2% of cases (Staphylococcus aureus, 26.6%; coagulase-negative staphylococci, 9.7%). Healthcare-associated IE represented 26.7% of all cases and exhibited a clinical pattern significantly different from that of community-acquired IE. S. aureus as the causal agent of IE was the most important factor associated with in-hospital death in community-acquired IE (hazard ratio [HR], 2.82 [95% CI, 1.72-4.61]) and the single factor in healthcare-associated IE (HR, 2.54 [95% CI, 1.33-4.85]). S. aureus became both the leading cause and the most important prognostic factor of IE, and healthcare-associated IE appeared as a major subgroup of the disease.

Annual diagnosis rate of superficial vein thrombosis of the lower limbs: the STEPH community-based study.

PubMed

Frappé, P; Buchmuller-Cordier, A; Bertoletti, L; Bonithon-Kopp, C; Couzan, S; Lafond, P; Leizorovicz, A; Merah, A; Presles, E; Preynat, P; Tardy, B; Décousus, H

2014-06-01

The incidence of superficial vein thrombosis (SVT) in the general adult population remains unknown. To assess the annual diagnosis rate of symptomatic, objectively confirmed lower limb SVT, associated or not with concomitant deep vein thrombosis and/or symptomatic pulmonary embolism. We conducted, from November 14, 2011, to November 13, 2012, a multicenter, community-based study in the Saint-Etienne urban area, France, representing a population of 265 687 adult residents (according to the 2009 census). All 248 general practitioners located within the area were asked to refer any patient with clinically suspected lower limb acute SVT to a vascular physician for systematic compression ultrasonography. All 28 vascular physicians located within the area participated in the study. The annual diagnosis rate, with the corresponding 95% confidence interval (CI), was calculated as the number of patients with symptomatic, objectively confirmed SVT divided by the number of person-years at risk defined by population data of the area. All venous thromboembolic events were validated by an independent central adjudication committee. Overall, 171 patients with symptomatic, confirmed SVT were reported. The annual diagnosis rate was 0.64& (95% CI, 0.55%-0.74&), was higher in women, and increased with advancing age regardless of gender [corrected]. Concomitant deep vein thrombosis (20 proximal) was observed in 42 patients (24.6% [95% CI, 18.3%-31.7%]), and concomitant symptomatic pulmonary embolism was observed in eight patients (4.7% [95% CI, 2.0%-9.0%]). This first community-based study showed that symptomatic SVT with confirmed diagnosis is a relatively common disease frequently associated with thromboembolic events in the deep venous system. © 2014 International Society on Thrombosis and Haemostasis.

Spatial and Temporal Analysis of Winter Fog Episodes over South Asia by exploiting ground-based and satellite observations

NASA Astrophysics Data System (ADS)

Fahim Khokhar, Muhammad; Yasmin, Naila; Zaib, Naila; Murtaza, Rabia; Noreen, Asma; Ishtiaq, Hira; Khayyam, Junaid; Panday, Arnico

2016-04-01

The South Asian region in general and the Indo-Gangetic Plains (IGP) in particular hold about 1/6th of the world's population and is considered as one of the major hotspots with increasing air pollution. Due to growing population and globalization, South Asia is experiencing high transformations in the urban and industrial sectors. Fog is one of the meteorological/environmental phenomena which can generate significant social and economic problems especially havoc to air and road traffic. Meteorological stations provide information about the fog episodes only on the basis of point observation. Continuous monitoring as well as a spatially coherent picture of fog distribution can only be possible through the use of satellite imagery. Current study focus on winter fog episodes over South Asian region using Moderate Resolution Image Spectrometer (MODIS) Level 2 Terra Product and other MODIS Aerosol Product in addition to ground-based sampling and AERONET measurements. MODIS Corrected Reflectance RGBs are used to analyse the spatial extent of fog over study area. MOD04 level 2 Collection 6 data is used to study aerosol load and distribution which are further characterised by using aerosol type land product of MODIS. In order to study the variation of ground based observations from satellite data MODIS, AERONET and high volume air Sampler were used. Main objective of this study was to explore the spatial extent of fog, its causes and to analyse the Aerosol Optical Depth (AOD) over South Asia with particular focus over Indo-Gangetic Plains (IGP). Current studies show a descent increase in AOD from past few decades over South Asia and is contributing to poor air quality in the region due to growing population, urbanization, and industrialization. Smoke and absorbing aerosol are major constituent of fog over South Asia. Furthermore, winter 2014-15 extended span of Fog was also observed over South Asia. A significant correlation between MODIS (AOD) and AERONET Station (AOD) data was identified. Mass concentration of PM2.5 and PM10 over sampling sites exceeded the Pak-NEQS at most occasions. However, during the current winter of 2015-16 the number of fog days has substantially reduced. Although, reasons are not clear yet but may be attributed to the atmospheric changes induced by the onset El-NINO.

Breed-specific incidence rates of canine primary bone tumors — A population based survey of dogs in Norway

PubMed Central

Anfinsen, Kristin P.; Grotmol, Tom; Bruland, Oyvind S.; Jonasdottir, Thora J.

2011-01-01

This is one of few published population-based studies describing breed specific rates of canine primary bone tumors. Incidence rates related to dog breeds could help clarify the impact of etiological factors such as birth weight, growth rate, and adult body weight/height on development of these tumors. The study population consisted of dogs within 4 large/giant breeds; Irish wolfhound (IW), Leonberger (LB), Newfoundland (NF), and Labrador retriever (LR), born between January 1st 1989 and December 31st 1998. Questionnaires distributed to owners of randomly selected dogs — fulfilling the criteria of breed, year of birth, and registration in the Norwegian Kennel Club — constituted the basis for this retrospective, population-based survey. Of the 3748 questionnaires received by owners, 1915 were completed, giving a response rate of 51%. Forty-three dogs had been diagnosed with primary bone tumors, based upon clinical examination and x-rays. The breeds IW and LB, with 126 and 72 cases per 10 000 dog years at risk (DYAR), respectively, had significantly higher incidence rates of primary bone tumors than NF and LR (P < 0.0001). Incidence rates for the latter were 11 and 2 cases per 10 000 DYAR, respectively. Pursuing a search for risk factors other than body size/weight is supported by the significantly different risks of developing primary bone tumors between similarly statured dogs, like NF and LB, observed in this study. Defining these breed-specific incidence rates enables subsequent case control studies, ultimately aiming to identify specific etiological factors for developing primary bone tumors. PMID:22210997

Forensic timber identification: a case study of a CITES listed species, Gonystylus bancanus (Thymelaeaceae).

PubMed

Ng, Kevin Kit Siong; Lee, Soon Leong; Tnah, Lee Hong; Nurul-Farhanah, Zakaria; Ng, Chin Hong; Lee, Chai Ting; Tani, Naoki; Diway, Bibian; Lai, Pei Sing; Khoo, Eyen

2016-07-01

Illegal logging and smuggling of Gonystylus bancanus (Thymelaeaceae) poses a serious threat to this fragile valuable peat swamp timber species. Using G. bancanus as a case study, DNA markers were used to develop identification databases at the species, population and individual level. The species level database for Gonystylus comprised of an rDNA (ITS2) and two cpDNA (trnH-psbA and trnL) markers based on a 20 Gonystylus species database. When concatenated, taxonomic species recognition was achieved with a resolution of 90% (18 out of the 20 species). In addition, based on 17 natural populations of G. bancanus throughout West (Peninsular Malaysia) and East (Sabah and Sarawak) Malaysia, population and individual identification databases were developed using cpDNA and STR markers respectively. A haplotype distribution map for Malaysia was generated using six cpDNA markers, resulting in 12 unique multilocus haplotypes, from 24 informative intraspecific variable sites. These unique haplotypes suggest a clear genetic structuring of West and East regions. A simulation procedure based on the composition of the samples was used to test whether a suspected sample conformed to a given regional origin. Overall, the observed type I and II errors of the databases showed good concordance with the predicted 5% threshold which indicates that the databases were useful in revealing provenance and establishing conformity of samples from West and East Malaysia. Sixteen STRs were used to develop the DNA profiling databases for individual identification. Bayesian clustering analyses divided the 17 populations into two main genetic clusters, corresponding to the regions of West and East Malaysia. Population substructuring (K=2) was observed within each region. After removal of bias resulting from sampling effects and population subdivision, conservativeness tests showed that the West and East Malaysia databases were conservative. This suggests that both databases can be used independently for random match probability estimation within respective regions. The reliability of the databases was further determined by independent self-assignment tests based on the likelihood of each individual's multilocus genotype occurring in each identified population, genetic cluster and region with an average percentage of correctly assigned individuals of 54.80%, 99.60% and 100% respectively. Thus, after appropriate validation, the genetic identification databases developed for G. bancanus in this study could support forensic applications and help safeguard this valuable species into the future. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Characterizing the Stellar Population of NGC 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kounkel, Marina; Hartmann, Lee; Calvet, Nuria

NGC 1980 is a young cluster that is located about 0.°5 south of the Orion Nebula Cluster (ONC). Recent studies by Bouy et al. and Pillitteri et al. have suggested that NGC 1980 contains an older population of stars compared to a much younger ONC, and that it belongs to a foreground population that may be located in front of the Orion A molecular gas by as much as 40 pc. In this work, we present low-resolution spectra toward 148 young stars found toward the NGC 1980 region. We determine the spectral types of these stars, examine accretion signatures and measuremore » the extinction toward them. We determine that based on these observations, the age of the population of NGC 1980 is indistinguishable from L1641, estimated to be ∼3 Myr, comparable with the study by Fang et al.« less

Use of driving-impairing medicines by a Spanish population: a population-based registry study

PubMed Central

Gutierrez-Abejón, Eduardo; Herrera-Gómez, Francisco; Criado-Espegel, Paloma

2017-01-01

Objective To assess the use of driving-impairing medicines (DIM) in the general population with special reference to length of use and concomitant use. Design Population-based registry study. Setting The year 2015 granted medicines consumption data recorded in the Castile and León (Spain) medicine dispensation registry was consulted. Participants Medicines and DIM consumers from a Spanish population (Castile and León: 2.4 million inhabitants). Exposure Medicines and DIM consumption. Patterns of use by age and gender based on the length of use (acute: 1–7 days, subacute: 8–29 days and chronic use: ≥30 days) were of interest. Estimations regarding the distribution of licensed drivers by age and gender were employed to determine the patterns of use of DIM. Results DIM were consumed by 34.4% (95% CI 34.3% to 34.5%) of the general population in 2015, more commonly with regularity (chronic use: 22.5% vs acute use: 5.3%) and more frequently by the elderly. On average, 2.3 DIM per person were dispensed, particularly to chronic users (2.8 DIM per person). Age and gender distribution differences were observed between the Castile and León medicine dispensation registry data and the drivers’ license census data. Of all DIM dispensed, 83.8% were in the Anatomical Therapeutic Chemical code group nervous system medicines (N), which were prescribed to 29.2% of the population. Conclusions The use of DIM was frequent in the general population. Chronic use was common, but acute and subacute use should also be considered. This finding highlights the need to make patients, health professionals, health providers, medicine regulatory agencies and policy-makers at large aware of the role DIM play in traffic safety. PMID:29170289

Balancing the Evidence: How to Reconcile the Results of Observational Studies vs. Randomized Clinical Trials in Dialysis.

PubMed

Shen, Jenny I; Lum, Erik L; Chang, Tara I

2016-09-01

Because large randomized clinical trials (RCTs) in dialysis have been relatively scarce, evidence-based dialysis care has depended heavily on the results of observational studies. However, when results from RCTs appear to contradict the findings of observational studies, nephrologists are left to wonder which type of study they should believe. In this editorial, we explore the key differences between observational studies and RCTs in the context of such seemingly conflicting studies in dialysis. Confounding is the major limitation of observational studies, whereas low statistical power and problems with external validity are more likely to limit the findings of RCTs. Differences in the specification of the population, exposure, and outcomes can also contribute to different results among RCTs and observational studies. Rigorous methods are required regardless of what type of study is conducted, and readers should not automatically assume that one type of study design is superior to the other. Ultimately, dialysis care requires both well-designed, well-conducted observational studies and RCTs to move the field forward. © 2016 Wiley Periodicals, Inc.

Balancing the Evidence: How to Reconcile the Results of Observational Studies vs. Randomized Clinical Trials in Dialysis

PubMed Central

Shen, Jenny I.; Lum, Erik L.; Chang, Tara I.

2016-01-01

Because large randomized clinical trials (RCTs) in dialysis have been relatively scarce, evidence-based dialysis care has depended heavily on the results of observational studies. However, when results from RCTs appear to contradict the findings of observational studies, nephrologists are left to wonder which type of study they should believe. In this editorial we explore the key differences between observational studies and RCTs in the context of such seemingly conflicting studies in dialysis. Confounding is the major limitation of observational studies, while low statistical power and problems with external validity are more likely to limit the findings of RCTs. Differences in the specification of the population, exposure, and outcomes can also contribute to different results among RCTs and observational studies. Rigorous methods are required regardless of what type of study is conducted, and readers should not automatically assume that one type of study design is superior to the other. Ultimately, dialysis care requires both well-designed, well-conducted observational studies and RCTs to move the field forward. PMID:27207819

Patterns of Mortality in Patients Treated with Dental Implants: A Comparison of Patient Age Groups and Corresponding Reference Populations.

PubMed

Jemt, Torsten; Kowar, Jan; Nilsson, Mats; Stenport, Victoria

2015-01-01

Little is known about the relationship between implant patient mortality compared to reference populations. The aim of this study was to report the mortality pattern in patients treated with dental implants up to a 15-year period, and to compare this to mortality in reference populations with regard to age at surgery, sex, and degree of tooth loss. Patient cumulative survival rate (CSR) was calculated for a total of 4,231 treated implant patients from a single clinic. Information was based on surgical registers in the clinic and the National Population Register in Sweden. Patients were arranged into age groups of 10 years, and CSR was compared to that of the reference population of comparable age and reported in relation to age at surgery, sex, and type of jaw/dentition. A similar, consistent, general relationship between CSR of different age groups of implant patients and reference populations could be observed for all parameters studied. Completely edentulous patients presented higher mortality than partially edentulous patients (P < .05). Furthermore, implant patients in younger age groups showed mortality similar to or higher than reference populations, while older patient age groups showed increasingly lower mortality than comparable reference populations for edentulous and partially edentulous patients (P < .05). A consistent pattern of mortality in different age groups of patients compared to reference populations was observed, indicating higher patient mortality in younger age groups and lower in older groups. The reported pattern is not assumed to be related to implant treatment per se, but is assumed to reflect the variation in general health of a selected subgroup of treated implant patients compared to the reference population in different age groups.

Integration of manatee life-history data and population modeling

USGS Publications Warehouse

Eberhardt, L.L.; O'Shea, Thomas J.; O'Shea, Thomas J.; Ackerman, B.B.; Percival, H. Franklin

1995-01-01

Aerial counts and the number of deaths have been a major focus of attention in attempts to understand the population status of the Florida manatee (Trichechus manatus latirostris). Uncertainties associated with these data have made interpretation difficult. However, knowledge of manatee life-history attributes increased and now permits the development of a population model. We describe a provisional model based on the classical approach of Lotka. Parameters in the model are based on data from'other papers in this volume and draw primarily on observations from the Crystal River, Blue Spring, and Adantic Coast areas. The model estimates X (the finite rate ofincrease) at each study area, and application ofthe delta method provides estimates of variance components and partial derivatives ofX with respectto key input parameters (reproduction, adult survival, and early survival). In some study areas, only approximations of some parameters are available. Estimates of X and coefficients of variation (in parentheses) of manatees were 1.07 (0.009) in the Crystal River, 1.06 (0.012) at Blue Spring, and 1.01 (0.012) on the Atlantic Coast. Changing adult survival has a major effect on X. Early-age survival has the smallest effect. Bootstrap comparisons of population growth estimates from trend counts in the Crystal River and at Blue Spring and the reproduction and survival data suggest that the higher, observed rates from counts are probably not due to chance. Bootstrapping for variance estimates based on reproduction and survival data from manatees at Blue Spring and in the Crystal River provided estimates of X, adult survival, and rates of reproduction that were similar to those obtained by other methods. Our estimates are preliminary and suggestimprovements for future data collection and analysis. However, results support efforts to reduce mortality as the most effective means to promote the increased growth necessary for the eventual recovery of the Florida manatee population.

Long‐term trends in fall age ratios of black brant

USGS Publications Warehouse

Ward, David H.; Amundson, Courtney L.; Stehn, Robert A.; Dau, Christian P.

2018-01-01

Accurate estimates of the age composition of populations can inform past reproductive success and future population trajectories. We examined fall age ratios (juveniles:total birds) of black brant (Branta bernicla nigricans; brant) staging at Izembek National Wildlife Refuge near the tip of the Alaska Peninsula, southwest Alaska, USA, 1963 to 2015. We also investigated variation in fall age ratios associated with sampling location, an index of flock size, survey effort, day of season, observer, survey platform (boat‐ or land‐based) and tide stage. We analyzed data using logistic regression models implemented in a Bayesian framework. Mean predicted fall age ratio controlling for survey effort, day of year, and temporal and spatial variation was 0.24 (95% CL = 0.23, 0.25). Overall trend in age ratios was −0.6% per year (95% CL = −1.3%, 0.2%), resulting in an approximate 26% decline in the proportion of juveniles over the study period. We found evidence for variation across a range of variables implying that juveniles are not randomly distributed in space and time within Izembek Lagoon. Age ratios varied by location within the study area and were highly variable among years. They decreased with the number of birds aged (an index of flock size) and increased throughout September before leveling off in early October and declining in late October. Age ratios were similar among tide stages and observers and were lower during boat‐based (offshore) than land‐based (nearshore) surveys. Our results indicate surveys should be conducted annually during early to mid‐October to ensure the entire population is present and available for sampling, and throughout Izembek Lagoon to account for spatiotemporal variation in age ratios. Sampling should include a wide range of flock sizes representative of their distribution and occur in flocks located near and off shore. Further research evaluating the cause of declining age ratios in the fall population is necessary to inform management and predict long‐term population dynamics of brant.

The impact of new transportation modes on population distribution in Jing-Jin-Ji region of China

PubMed Central

Wang, Lizhe; Chen, Lajiao

2018-01-01

This paper conducts a novel study in China’s Jing-Jin-Ji region to investigate the determinants of population distribution and short-term migration based on a comprehensive dataset including traditional census data, earth observation data, and emerging Internet data. Our results show that due to the high level of urbanization in this region, natural conditions are no longer the strongest determinants of population distribution. New transportation modes, such as high-speed rail, have arisen as a significant determinant of population distribution and short-term migration, particularly in large cities. Socio-economic factors such as GDP, investment, urbanization level, and technology, which are traditionally assumed to govern population distribution and short-term migration, have less influence although education still remains an important factor affecting population distribution. These findings will contribute valuable information to regional planning decision-making in the Jing-Jin-Ji region. PMID:29360105

Mealtime Energy Intake and Feeding Behaviour in Children Who Fail to Thrive: A Population-Based Case-Control Study

ERIC Educational Resources Information Center

Parkinson, Kathryn N.; Wright, Charlotte M.; Drewett, Robert F.

2004-01-01

Background: The essential link between energy needs and energy intake is feeding behaviour, yet few studies have directly observed feeding behaviour in children who have failed to thrive. A cohort of 961 term infants was screened to identify children with first year weight gain below the 5th centile in order to examine their feeding behaviour and…

Yellowstone bison genetics: let us move forward

USGS Publications Warehouse

Halbert, Natalie D.; Gogan, Peter J.P.; Hedrick, Philip W.; Wahl, Jacquelyn M.; Derr, James N.

2012-01-01

White and Wallen (2012) disagree with the conclusions and suggestions made in our recent assessment of population structure among Yellowstone National Park (YNP) bison based on 46 autosomal microsatellite loci in 661 animals (Halbert et al. 2012). First, they suggest that "the existing genetic substructure (that we observed) was artificially created." Specifically, they suggest that the substructure observed between the northern and central populations is the result of human activities, both historical and recent. In fact, the genetic composition of all known existing bison herds was created by, or has been influenced by, anthropogenic activities, although this obviously does not reduce the value of these herds for genetic conservation (Dratch and Gogan 2010). As perspective, many, if not most, species of conservation concern have been influenced by human actions and as a result currently exist as isolated populations. However, it is quite difficult to distinguish between genetic differences caused by human actions and important ancestral variation contained in separate populations without data from early time periods. Therefore, to not lose genetic variation that may be significant or indicative of important genetic variation, the generally acceptable management approach is to attempt to retain this variation based on the observed population genetic subdivision (Hedrick et al. 1986).

Estimating a Global Hydrological Carrying Capacity Using GRACE Observed Water Stress

NASA Astrophysics Data System (ADS)

An, K.; Reager, J. T.; Famiglietti, J. S.

2013-12-01

Global population is expected to reach 9 billion people by the year 2050, causing increased demands for water and potential threats to human security. This study attempts to frame the overpopulation problem through a hydrological resources lens by hypothesizing that observed groundwater trends should be directly attributed to human water consumption. This study analyzes the relationships between available blue water, population, and cropland area on a global scale. Using satellite data from NASA's Gravity Recovery and Climate Experiment (GRACE) along with land surface model data from the Global Land Data Assimilation System (GLDAS), a global groundwater depletion trend is isolated, the validity of which has been verified in many regional studies. By using the inherent distributions of these relationships, we estimate the regional populations that have exceeded their local hydrological carrying capacity. Globally, these populations sum to ~3.5 billion people that are living in presently water-stressed or potentially water-scarce regions, and we estimate total cropland is exceeding a sustainable threshold by about 80 million km^2. Key study areas such as the North China Plain, northwest India, and Mexico City were qualitatively chosen for further analysis of regional water resources and policies, based on our distributions of water stress. These case studies are used to verify the groundwater level changes seen in the GRACE trend . Tfor the many populous, arid regions of the world that have already begun to experience the strains of high water demand.he many populous, arid regions of the world have already begun to experience the strains of high water demand. It will take a global cooperative effort of improving domestic and agricultural use efficiency, and summoning a political will to prioritize environmental issues to adapt to a thirstier planet. Global Groundwater Depletion Trend (Mar 2003-Dec 2011)

Addictive behaviors related to opioid use for chronic pain: a population-based study.

PubMed

Højsted, Jette; Ekholm, Ola; Kurita, Geana Paula; Juel, Knud; Sjøgren, Per

2013-12-01

The growing body of research showing increased opioid use in patients with chronic pain coupled with concerns regarding addiction encouraged the development of this population-based study. The goal of the study was to investigate the co-occurrence of indicators of addictive behaviors in patients with chronic non-cancer pain in long-term opioid treatment. The study combined data from the individual-based Danish Health Survey in 2010 and the official Danish health and socio-economic, individual-based registers. From a simple random sample of 25,000 adults (16 years or older) living in Denmark, 13,281 individuals were analyzed through multiple logistic regression analyses to assess the association between chronic pain (lasting ≥6 months), opioid use, health behavior, and body mass index. Six potential addictive behaviors were identified: daily smoking; high alcohol intake; illicit drug use in the past year; obesity; long-term use of benzodiazepines; and long-term use of benzodiazepine-related drugs. At least 2 of the 6 addictive behaviors were observed in 22.6% of the long-term opioid users with chronic pain compared with 11.5% of the non-opioid users with chronic pain and 8.9% of the individuals without chronic pain. Thus, a strong association was demonstrated between long-term opioid use and the clustering of addictive behaviors. An intricate relationship between chronic pain, opioid use, and addictive behaviors was observed in this study, which deserves both clinical attention and further research. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

The gamma-ray pulsar population of globular clusters: Implications for the GeV excess

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hooper, Dan; Linden, Tim

In this study, it has been suggested that the GeV excess, observed from the region surrounding the Galactic Center, might originate from a population of millisecond pulsars that formed in globular clusters. With this in mind, we employ the publicly available Fermi data to study the gamma-ray emission from 157 globular clusters, identifying a statistically significant signal from 25 of these sources (ten of which are not found in existing gamma-ray catalogs). We combine these observations with the predicted pulsar formation rate based on the stellar encounter rate of each globular cluster to constrain the gamma-ray luminosity function of millisecondmore » pulsars in the Milky Way's globular cluster system. We find that this pulsar population exhibits a luminosity function that is quite similar to those millisecond pulsars observed in the field of the Milky Way (i.e. the thick disk). After pulsars are expelled from a globular cluster, however, they continue to lose rotational kinetic energy and become less luminous, causing their luminosity function to depart from the steady-state distribution. Using this luminosity function and a model for the globular cluster disruption rate, we show that millisecond pulsars born in globular clusters can account for only a few percent or less of the observed GeV excess. Among other challenges, scenarios in which the entire GeV excess is generated from such pulsars are in conflict with the observed mass of the Milky Way's Central Stellar Cluster.« less

The gamma-ray pulsar population of globular clusters: Implications for the GeV excess

DOE PAGES

Hooper, Dan; Linden, Tim

2016-08-09

In this study, it has been suggested that the GeV excess, observed from the region surrounding the Galactic Center, might originate from a population of millisecond pulsars that formed in globular clusters. With this in mind, we employ the publicly available Fermi data to study the gamma-ray emission from 157 globular clusters, identifying a statistically significant signal from 25 of these sources (ten of which are not found in existing gamma-ray catalogs). We combine these observations with the predicted pulsar formation rate based on the stellar encounter rate of each globular cluster to constrain the gamma-ray luminosity function of millisecondmore » pulsars in the Milky Way's globular cluster system. We find that this pulsar population exhibits a luminosity function that is quite similar to those millisecond pulsars observed in the field of the Milky Way (i.e. the thick disk). After pulsars are expelled from a globular cluster, however, they continue to lose rotational kinetic energy and become less luminous, causing their luminosity function to depart from the steady-state distribution. Using this luminosity function and a model for the globular cluster disruption rate, we show that millisecond pulsars born in globular clusters can account for only a few percent or less of the observed GeV excess. Among other challenges, scenarios in which the entire GeV excess is generated from such pulsars are in conflict with the observed mass of the Milky Way's Central Stellar Cluster.« less

Traffic-related air pollution increased the risk of Parkinson's disease in Taiwan: A nationwide study.

PubMed

Lee, Pei-Chen; Liu, Li-Ling; Sun, Yu; Chen, Yu-An; Liu, Chih-Ching; Li, Chung-Yi; Yu, Hwa-Lung; Ritz, Beate

2016-11-01

Ambient air pollution has been associated with many health conditions, but little is known about its effects on neurodegenerative diseases, such as Parkinson's disease (PD). In this study, we investigated the influence of ambient air pollution on PD in a nationwide population-based case-control study in Taiwan. We identified 11,117 incident PD patients between 2007 and 2009 from the Taiwanese National Health Insurance Research Database and selected 44,468 age- and gender-matched population controls from the longitudinal health insurance database. The average ambient pollutant exposure concentrations from 1998 through the onset of PD were estimated using quantile-based Bayesian Maximum Entropy models. Basing from logistic regression models, we estimated the odds ratios (ORs) and 95% confidence intervals (CIs) of ambient pollutant exposures and PD risk. We observed positive associations between NO x , CO exposures, and PD. In multi-pollutant models, for NO x and CO above the 75th percentile exposure compared with the lowest percentile, the ORs of PD were 1.37 (95% CI=1.23-1.52) and 1.17 (95% CI=1.07-1.27), respectively. This study suggests that ambient air pollution exposure, especially from traffic-related pollutants such as NO x and CO, increases PD risk in the Taiwanese population. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Bayesian approach to the creation of a study-customized neonatal brain atlas

PubMed Central

Zhang, Yajing; Chang, Linda; Ceritoglu, Can; Skranes, Jon; Ernst, Thomas; Mori, Susumu; Miller, Michael I.; Oishi, Kenichi

2014-01-01

Atlas-based image analysis (ABA), in which an anatomical “parcellation map” is used for parcel-by-parcel image quantification, is widely used to analyze anatomical and functional changes related to brain development, aging, and various diseases. The parcellation maps are often created based on common MRI templates, which allow users to transform the template to target images, or vice versa, to perform parcel-by-parcel statistics, and report the scientific findings based on common anatomical parcels. The use of a study-specific template, which represents the anatomical features of the study population better than common templates, is preferable for accurate anatomical labeling; however, the creation of a parcellation map for a study-specific template is extremely labor intensive, and the definitions of anatomical boundaries are not necessarily compatible with those of the common template. In this study, we employed a Volume-based Template Estimation (VTE) method to create a neonatal brain template customized to a study population, while keeping the anatomical parcellation identical to that of a common MRI atlas. The VTE was used to morph the standardized parcellation map of the JHU-neonate-SS atlas to capture the anatomical features of a study population. The resultant “study-customized” T1-weighted and diffusion tensor imaging (DTI) template, with three-dimensional anatomical parcellation that defined 122 brain regions, was compared with the JHU-neonate-SS atlas, in terms of the registration accuracy. A pronounced increase in the accuracy of cortical parcellation and superior tensor alignment were observed when the customized template was used. With the customized atlas-based analysis, the fractional anisotropy (FA) detected closely approximated the manual measurements. This tool provides a solution for achieving normalization-based measurements with increased accuracy, while reporting scientific findings in a consistent framework. PMID:25026155

A continuation of base-line studies for environmentally monitoring Space Transportation Systems (STS) at John F. Kennedy Space Center. Volume 4: Threatened and endangered species of the Kennedy Space Center. Part 1: Marine turtle studies

NASA Technical Reports Server (NTRS)

Ehrhart, L. M.

1980-01-01

The status of marine turtle populations in the KSC area was studied using data from previous results from ground and aerial surveillance conducted from 1976 to April 1979. During ground surveillance, various data were recorded on emergent turtles such as: species, weight, tag number (if previously tagged), time discovered, activity at discovery and the location of discovery. Observations were also made on nesting and reproductive characteristics, population estimates, immigration and emigration and growth rate of the turtles. Mortality studies were additionally made and autopsies performed on dead turtles found in the area. It is concluded that further mortality documentation should be done just prior to and just after a future space launch operation in order to accurately assess the cause and effect relationship of such a launch on the turtle population.

Assessment of sexual risk behaviors and perception of vulnerability to sexually transmitted diseases/acquired immunodeficiency syndrome in women, 1999-2012: a population based survey in a medium-sized Brazilian city.

PubMed

Mesenburg, Marilia Arndt; Muniz, Ludmila Correa; Silveira, Mariângela Freitas

2014-01-01

Sexual behavior is a key factor for susceptibility to sexually transmitted diseases. An evaluation of the sexual behavior of women at reproductive age was conducted in 1999. A replication of this study aims to evaluate the current situation and identify changes in sexual behavior, 13 years later. This is a population-based cross-sectional study, conducted with 1071 women in Pelotas, Brazil. Compared to the 1999 study, a 14% increase in early sexual debut and an 8% decrease in the non-use of condoms were observed in 2012. The proportion of women who reported anal sex doubled between these periods. There was no trend of increase or decrease in the prevalence of behaviors with distinct patterns being observed for each of them. Reduction of non-use of condoms may be an indicator of the effectiveness of campaigns to promote safe sex. However, the increased prevalence of early sexual debut and anal sex indicates the need for campaigns to continue and to expand their focus, especially among vulnerable groups. Copyright © 2014 Elsevier Editora Ltda. All rights reserved.

Solar Wind Strahl Observations and Their Implication to the Core-Halo Formation due to Scattering

NASA Technical Reports Server (NTRS)

Vinas, Adolfo F.

2011-01-01

A study of the kinetic properties of the strahl electron velocity distribution functions (VDF?s) in the solar wind is presented. This study focuses on the mechanisms that control and regulate the electron VDF?s and the stability of the strahl electrons in the solar wind; mechanisms that are not yet well understood. Various parameters are investigated such as the strahl-electron density, temperature anisotropy, and electron heat-flux. These parameters are used to investigate the stability of the strahl population. The analysis check for whether the strahl electrons are constrained by some instability (e.g., the whistler or KAW instabilities), or are maintained by other types of processes. The electron heat-flux and temperature anisotropy are determined by modeling of the 3D-VDF?s from which the moments properties of the various populations are obtained. The results of this study have profound implication on the current hypothesis about the probable formation of the solar wind halo electrons produced from the scattering of the strahl population. This hypothesis is strengthened by direct observations of the strahl electrons being scattered into the core-halo in an isolated event. The observation implies that the scattering of the strahl is not a continuous process but occurs in bursts in regions where conditions for wave growth providing the scattering are optimum. Sometimes, observations indicate that the strahl component is anisotropic (Tper/Tpal approx. 2). This provides a possible free energy source for the excitation of whistler waves as a possible scattering mechanism, however this condition is not always observed. The study is based on high time resolution data from the Cluster/PEACE electron spectrometer.

Blastopathies and microcephaly in a Chornobyl impacted region of Ukraine

PubMed Central

Wertelecki, Wladimir; Yevtushok, Lyubov; Zymak-Zakutnia, Natalia; Wang, Bin; Sosyniuk, Zoriana; Lapchenko, Serhiy; Hobart, Holly H

2014-01-01

This population-based descriptive epidemiology study demonstrates that rates of conjoined twins, teratomas, neural tube defects, microcephaly, and microphthalmia in the Rivne province of Ukraine are among the highest in Europe. The province is 200 km distant from the Chornobyl site and its northern half, a region known as Polissia, is significantly polluted by ionizing radiation. The rates of neural tube defects, microcephaly and microphthalmia in Polissia are statistically significantly higher than in the rest of the province. A survey of at-birth head size showed that values were statistically smaller in males and females born in one Polissia county than among neonates born in the capital city. These observations provide clues for confirmatory and cause-effect prospective investigations. The strength of this study stems from a reliance on international standards prevalent in Europe and a decade-long population-based surveillance of congenital malformations in two distinct large populations. The limitations of this study, as those of other descriptive epidemiology investigations, is that identified cause-effect associations require further assessment by specific prospective investigations designed to address specific teratogenic factors. PMID:24666273

Changes in anthropometrical data of the Hungarian child and adult population during the last thirty years based on family studies conducted by the Department of Forensic Medicine at Budapest.

PubMed

Magyar, Lóránt; Bellovits, Orsolya; Bujdosó, Györgyi

2006-06-01

Studies of the Hungarian child and adult population have revealed striking changes over the past thirty years with respect to body height and body mass, an observation, which has also been confirmed by other investigations (Gyenis & Joubert 2003, Maródi et. al. 2002). Based on these deviations the authors were interested in the variability of some anthropometrical head measures, which are of particular importance for forensic anthropological questions concerning face reconstruction (Editorial 2001, Jayprakash et. al. 2001, Szilvdssy & Kritscher 1997, Szilvdssy et al. 1997). The majority of such reconstruction methods, however, do not take into consideration the process of secular trend. It is the aim of this study to improve the anthropological basis for exact reconstruction methods by elaboration of temporal changes of face, head and body measures of the Hungarian population collected during the past thirty years. For this data from 2353 adults and 861 children investigated in 1974, and 869 adults 287 children investigated between 1994 and 2004 are available.

Removing Obstacles To Eliminating Racial And Ethnic Disparities In Behavioral Health Care.

PubMed

Alegría, Margarita; Alvarez, Kiara; Ishikawa, Rachel Zack; DiMarzio, Karissa; McPeck, Samantha

2016-06-01

Despite decades of research, racial and ethnic disparities in behavioral health care persist. The Affordable Care Act expanded access to behavioral health care, but many reform initiatives fail to consider research about racial/ethnic minorities. Mistaken assumptions that underlie the expansion of behavioral health care run the risk of replicating existing service disparities. Based on a review of relevant literature and numerous observational and field studies with minority populations, we identified the following three mistaken assumptions: Improvement in health care access alone will reduce disparities, current service planning addresses minority patients' preferences, and evidence-based interventions are readily available for diverse populations. We propose tailoring the provision of care to remove obstacles that minority patients face in accessing treatment, promoting innovative services that respond to patients' needs and preferences, and allowing flexibility in evidence-based practice and the expansion of the behavioral health workforce. These proposals should help meet the health care needs of a growing racial/ethnic minority population. Project HOPE—The People-to-People Health Foundation, Inc.

Removing Obstacles To Eliminate Racial And Ethnic Disparities In Behavioral Health Care

PubMed Central

Alegría, Margarita; Alvarez, Kiara; Ishikawa, Rachel Zack; DiMarzio, Karissa; McPeck, Samantha

2016-01-01

Despite decades of research, racial and ethnic disparities in behavioral health care persist. The Affordable Care Act expanded access to behavioral health care, but many reform initiatives fail to consider research about racial/ethnic minorities. Mistaken assumptions that underlie the expansion of behavioral health care risk replicating existing service disparities. Based on a review of relevant literature and numerous observational and field studies with minority populations, we identified the following three mistaken assumptions: improvement in health care access alone will reduce disparities, current service planning addresses minority patients’ preferences, and evidence-based interventions are readily available for diverse populations. We propose tailoring the provision of care to remove obstacles that minority patients face in accessing treatment, promoting innovative services that respond to patient needs and preferences, and allowing flexibility in evidence-based practice and the expansion of the behavioral health workforce. These proposals should help meet the health care needs of a growing racial/ethnic minority population. PMID:27269014

Relevance of single-particle and collective excitations in zirconium isotopes populated by neutron transfer reactions in the {sup 90}Zr+{sup 208}Pb system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pajtler, M. Varga, E-mail: maja.varga@fizika.unios.hr; Szilner, S.; Malenica, D. Jelavić

2015-10-15

Multineutron transfer reaction {sup 90}Zr+{sup 208}Pb has been studied at the energy close to the Coulomb barrier energy by using the PRISMA + CLARA set-up. In this fragment-γ coincidence measurement, the selective properties of the reaction mechanism in the population of the specific states have been discussed. Based on the observed γ transitions of neutron transfer channels, namely {sup 89–94}Zr isotopes, their level schemes have been constructed and updated.

Association Between Barracks Type and Acute Respiratory Infection in a Gender Integrated Army Basic Combat Training Population

PubMed Central

White, Duvel W.; Feigley, Charles E.; McKeown, Robert E.; Hout, Joseph J.; Hebert, James R.

2015-01-01

Background Acute respiratory infections (ARIs) are the leading cause of acute morbidity and lost work time in the United States. Few studies have looked at building design and transmission of ARIs. Objectives This study explores the association of ventilation design, room occupancy numbers, and training week with ARI rates in Army Basic Combat Training barracks. Methods This observational study captured the overall incidence of ARI in a cohort of 16,258 individuals attending basic combat training at Fort Jackson, South Carolina. Results ARI risk was higher among trainees living in the 60-person room barracks compared with those living in 8-person rooms, which increased rapidly for the first few weeks of training and then declined to baseline. Conclusions Findings support direct contact as primary ARI transmission mode in this study population based on observed lower ARI risk in smaller room barracks and similar risk in large room barracks despite heating, ventilation, and air conditioning system variability. PMID:21882781

Exposure to community violence and self-harm in California: A multi-level, population-based, case-control study.

PubMed

Matthay, Ellicott C; Farkas, Kriszta; Skeem, Jennifer; Ahern, Jennifer

2018-06-07

Self-harm is a leading cause of morbidity and mortality. Exposure to community violence is an important and potentially modifiable feature of the social environment that may affect self-harm, but studies to date are limited in the samples and outcomes examined. We conducted a population-based, nested case-control study. Cases were all deaths and hospital visits due to self-harm in California, 2006-2013. We frequency-matched California resident population-based controls from the American Community Survey to cases on age, gender, race/ethnicity, and year of survey/injury. We assessed past-year community violence using deaths and hospital visits due to interpersonal violence in the community of residence. We estimated risk-difference parameters that were defined to avoid extrapolation and to capture associations between changes in the distribution of community violence and the population-level risk of self-harm. After adjustment for confounders, setting past-year community violence to the lowest monthly levels observed within each community over the study period was associated with a 30.1 (95% CI: 29.6 to 30.5) per 100,000 persons per year lower risk of nonfatal self-harm, but no difference in the risk of fatal self-harm. Associations for a parameter corresponding to a hypothetical violence prevention intervention targeting high-violence communities indicated a 5% decrease in self-harm at the population level. In sensitivity analyses, results were robust. This study strengthens evidence on the relationship between community violence and self-harm. Future research should investigate reasons for differential associations by age and gender and whether community violence prevention programs have meaningful impacts on self-harm.

A panel of ancestry informative markers to estimate and correct potential effects of population stratification in Han Chinese.

PubMed

Qin, Pengfei; Li, Zhiqiang; Jin, Wenfei; Lu, Dongsheng; Lou, Haiyi; Shen, Jiawei; Jin, Li; Shi, Yongyong; Xu, Shuhua

2014-02-01

Population stratification acts as a confounding factor in genetic association studies and may lead to false-positive or false-negative results. Previous studies have analyzed the genetic substructures in Han Chinese population, the largest ethnic group in the world comprising ∼20% of the global human population. In this study, we examined 5540 Han Chinese individuals with about 1 million single-nucleotide polymorphisms (SNPs) and screened a panel of ancestry informative markers (AIMs) to facilitate the discerning and controlling of population structure in future association studies on Han Chinese. Based on genome-wide data, we first confirmed our previous observation of the north-south differentiation in Han Chinese population. Second, we developed a panel of 150 validated SNP AIMs to determine the northern or southern origin of each Han Chinese individual. We further evaluated the performance of our AIMs panel in association studies in simulation analysis. Our results showed that this AIMs panel had sufficient power to discern and control population stratification in Han Chinese, which could significantly reduce false-positive rates in both genome-wide association studies (GWAS) and candidate gene association studies (CGAS). We suggest this AIMs panel be genotyped and used to control and correct population stratification in the study design or data analysis of future association studies, especially in CGAS which is the most popular approach to validate previous reports on genetic associations of diseases in post-GWAS era.

Early warning signal for dengue outbreaks and identification of high risk areas for dengue fever in Colombia using climate and non-climate datasets.

PubMed

Lee, Jung-Seok; Carabali, Mabel; Lim, Jacqueline K; Herrera, Victor M; Park, Il-Yeon; Villar, Luis; Farlow, Andrew

2017-07-10

Dengue has been prevalent in Colombia with high risk of outbreaks in various locations. While the prediction of dengue epidemics will bring significant benefits to the society, accurate forecasts have been a challenge. Given competing health demands in Colombia, it is critical to consider the effective use of the limited healthcare resources by identifying high risk areas for dengue fever. The Climate Risk Factor (CRF) index was constructed based upon temperature, precipitation, and humidity. Considering the conditions necessary for vector survival and transmission behavior, elevation and population density were taken into account. An Early Warning Signal (EWS) model was developed by estimating the elasticity of the climate risk factor function to detect dengue epidemics. The climate risk factor index was further estimated at the smaller geographical unit (5 km by 5 km resolution) to identify populations at high risk. From January 2007 to December 2015, the Early Warning Signal model successfully detected 75% of the total number of outbreaks 1 ~ 5 months ahead of time, 12.5% in the same month, and missed 12.5% of all outbreaks. The climate risk factors showed that populations at high risk are concentrated in the Western part of Colombia where more suitable climate conditions for vector mosquitoes and the high population level were observed compared to the East. This study concludes that it is possible to detect dengue outbreaks ahead of time and identify populations at high risk for various disease prevention activities based upon observed climate and non-climate information. The study outcomes can be used to minimize potential societal losses by prioritizing limited healthcare services and resources, as well as by conducting vector control activities prior to experiencing epidemics.

Do You See What I See? Exploring the Consequences of Luminosity Limits in Black Hole–Galaxy Evolution Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, Mackenzie L.; Hickox, Ryan C.; DiPompeo, Michael A.

In studies of the connection between active galactic nuclei (AGNs) and their host galaxies, there is widespread disagreement on some key aspects of the connection. These disagreements largely stem from a lack of understanding of the nature of the full underlying AGN population. Recent attempts to probe this connection utilize both observations and simulations to correct for a missed population, but presently are limited by intrinsic biases and complicated models. We take a simple simulation for galaxy evolution and add a new prescription for AGN activity to connect galaxy growth to dark matter halo properties and AGN activity to starmore » formation. We explicitly model selection effects to produce an “observed” AGN population for comparison with observations and empirically motivated models of the local universe. This allows us to bypass the difficulties inherent in models that attempt to infer the AGN population by inverting selection effects. We investigate the impact of selecting AGNs based on thresholds in luminosity or Eddington ratio on the “observed” AGN population. By limiting our model AGN sample in luminosity, we are able to recreate the observed local AGN luminosity function and specific star formation-stellar mass distribution, and show that using an Eddington ratio threshold introduces less bias into the sample by selecting the full range of growing black holes, despite the challenge of selecting low-mass black holes. We find that selecting AGNs using these various thresholds yield samples with different AGN host galaxy properties.« less

Public health research: lost in translation or speaking the wrong language?

PubMed

Kansagra, Susan M; Farley, Thomas A

2011-12-01

Public health leaders, like physicians, need to make decisions that impact health based on strong evidence. To generate useful evidence for public health leaders, research must focus on interventions that have potential to impact population-level health. Often policy and environmental changes are the interventions with the greatest potential impact on population health, but studying these is difficult because of limitations in the methods typically used and emphasized in health research. To create useful evidence for policy and environmental interventions, other research methods are needed, including observational studies, the use of surveillance data for evaluation, and predictive mathematical modeling. More emphasis is needed on these types of study designs by researchers, funding agencies, and scientific journals.

Comparison of individual-based modeling and population approaches for prediction of foodborne pathogens growth.

PubMed

Augustin, Jean-Christophe; Ferrier, Rachel; Hezard, Bernard; Lintz, Adrienne; Stahl, Valérie

2015-02-01

Individual-based modeling (IBM) approach combined with the microenvironment modeling of vacuum-packed cold-smoked salmon was more effective to describe the variability of the growth of a few Listeria monocytogenes cells contaminating irradiated salmon slices than the traditional population models. The IBM approach was particularly relevant to predict the absence of growth in 25% (5 among 20) of artificially contaminated cold-smoked salmon samples stored at 8 °C. These results confirmed similar observations obtained with smear soft cheese (Ferrier et al., 2013). These two different food models were used to compare the IBM/microscale and population/macroscale modeling approaches in more global exposure and risk assessment frameworks taking into account the variability and/or the uncertainty of the factors influencing the growth of L. monocytogenes. We observed that the traditional population models significantly overestimate exposure and risk estimates in comparison to IBM approach when contamination of foods occurs with a low number of cells (<100 per serving). Moreover, the exposure estimates obtained with the population model were characterized by a great uncertainty. The overestimation was mainly linked to the ability of IBM to predict no growth situations rather than the consideration of microscale environment. On the other hand, when the aim of quantitative risk assessment studies is only to assess the relative impact of changes in control measures affecting the growth of foodborne bacteria, the two modeling approach gave similar results and the simplest population approach was suitable. Copyright © 2014 Elsevier Ltd. All rights reserved.

Inverse Association Between Cancer and Dementia: A Population-based Registry Study in Taiwan.

PubMed

Lin, Hsiu-Li; Lin, Hsiu-Chen; Tseng, Yuan-Fu; Chen, Shih-Chang; Hsu, Chien-Yeh

2016-01-01

Dementia and cancer are 2 common diseases in the elderly. This retrospective cohort study used a population-based insurance claim dataset, merged with a cancer registry, to test whether risk reduction of cancers occurs at various primary sites after diagnosis of dementia. The study included a cohort of 3282 patients who were first diagnosed with dementia between 2001 and 2002. A control cohort consisted of 13,128 subjects matched for age, sex, and year of enrollment. The site of cancer and duration between the diagnosis of dementia and cancer were analyzed. Among the dementia cases, 169 patients (5.2%) were diagnosed with cancer during a median observation period of 40 months. In the control group, 976 subjects (7.4%) were diagnosed with cancer, during a median observation period of 46 months. During a 7-year follow-up period, the adjusted hazard ratio for cancer among dementia patients was 0.77 (95% confidence interval, 0.65-0.91), and significantly lower for colon (0.54, 0.29-0.99) and prostate cancers (0.44, 0.20-0.98). This study showed an inverse association between cancer and dementia. Further studies focusing on colon and prostate cancers may help elucidate the underlying mechanism and expand the therapeutic strategies.

Reconsidering the use of rankings in the valuation of health states: a model for estimating cardinal values from ordinal data

PubMed Central

Salomon, Joshua A

2003-01-01

Background In survey studies on health-state valuations, ordinal ranking exercises often are used as precursors to other elicitation methods such as the time trade-off (TTO) or standard gamble, but the ranking data have not been used in deriving cardinal valuations. This study reconsiders the role of ordinal ranks in valuing health and introduces a new approach to estimate interval-scaled valuations based on aggregate ranking data. Methods Analyses were undertaken on data from a previously published general population survey study in the United Kingdom that included rankings and TTO values for hypothetical states described using the EQ-5D classification system. The EQ-5D includes five domains (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) with three possible levels on each. Rank data were analysed using a random utility model, operationalized through conditional logit regression. In the statistical model, probabilities of observed rankings were related to the latent utilities of different health states, modeled as a linear function of EQ-5D domain scores, as in previously reported EQ-5D valuation functions. Predicted valuations based on the conditional logit model were compared to observed TTO values for the 42 states in the study and to predictions based on a model estimated directly from the TTO values. Models were evaluated using the intraclass correlation coefficient (ICC) between predictions and mean observations, and the root mean squared error of predictions at the individual level. Results Agreement between predicted valuations from the rank model and observed TTO values was very high, with an ICC of 0.97, only marginally lower than for predictions based on the model estimated directly from TTO values (ICC = 0.99). Individual-level errors were also comparable in the two models, with root mean squared errors of 0.503 and 0.496 for the rank-based and TTO-based predictions, respectively. Conclusions Modeling health-state valuations based on ordinal ranks can provide results that are similar to those obtained from more widely analyzed valuation techniques such as the TTO. The information content in aggregate ranking data is not currently exploited to full advantage. The possibility of estimating cardinal valuations from ordinal ranks could also simplify future data collection dramatically and facilitate wider empirical study of health-state valuations in diverse settings and population groups. PMID:14687419

Surface intervalley scattering on GaAs(110) studied with picosecond laser photoemission

NASA Astrophysics Data System (ADS)

Haight, R.; Silberman, J. A.

1990-01-01

Laser-based photoemission sources provide the unique opportunity to study dynamic electronic processes at surfaces and interfaces. Using angle-resolved, laser photoemission with < 1 ps time resolution, we have directly observed a new surface band at the X¯ point in the GaAs(110) surface Brillouin zone. The appearance of electron population in this valley occurs only as a result of scattering from the directly photoexcited valley at overlineГ. The momentum resolution of our experiment has permitted us to isolate the dynamic electron population changes at both overlineГ and X¯ and to deduce the scattering time between the two valleys.

Occupation and thyroid cancer: a population-based case-control study in Connecticut

PubMed Central

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

Association of socio-economic, gender and health factors with common mental disorders in women: a population-based study of 5703 married rural women in India.

PubMed

Shidhaye, Rahul; Patel, Vikram

2010-12-01

There are few population-based studies from low- and middle-income countries that have described the association of socio-economic, gender and health factors with common mental disorders (CMDs) in rural women. Population-based study of currently married rural women in the age group of 15-39 years. The baseline data are from the National Family Health Survey-II conducted in 1998. A follow-up study was conducted 4 years later in 2002-03. The outcome of CMD was assessed using the 12-item General Health Questionnaire (GHQ-12). Due to the hierarchical nature and complex survey design, data were analysed using mixed-effect logistic regression with random intercept model. A total of 5703 women (representing 83.5% of eligible women) completed follow-up. The outcome of CMD was observed in 609 women (10.7%, 95% confidence interval 9.8-11.6). The following factors were independently associated with the outcome of CMD in the final multivariable model: higher age, low education, low standard of living, recent intimate partner violence (IPV), husband's unsatisfactory reaction to dowry, husband's alcohol use and women's own tobacco use. Socio-economic and gender disadvantage factors are independently associated with CMDs in this population of women. Strategies that address structural determinants, for example to promote women's education and reduce their exposure to IPV, may reduce the burden of CMDs in women.

Population genetic structure analysis and forensic evaluation of Xinjiang Uigur ethnic group on genomic deletion and insertion polymorphisms.

PubMed

Mei, Ting; Shen, Chun-Mei; Liu, Yao-Shun; Meng, Hao-Tian; Zhang, Yu-Dang; Guo, Yu-Xin; Dong, Qian; Wang, Xin-Xin; Yan, Jiang-Wei; Zhu, Bo-Feng; Zhang, Li-Ping

2016-01-01

The Uigur ethnic minority is the largest ethnic group in the Xinjiang Uygur Autonomous Region of China, and valuable resource for the study of ethnogeny. The objective of this study was to estimate the genetic diversities and forensic parameters of 30 insertion-deletion loci in Uigur ethnic group from Xinjiang Uigur Autonomous Region of China and to analyze the genetic relationships between Xinjiang Uigur group and other previously published groups based on population data of these loci. All the tested loci were conformed to Hardy-Weinberg equilibrium after Bonferroni correction. The observed and expected heterozygosity ranged from 0.3750 to 0.5515; and 0.4057 to 0.5037, respectively. The combined power of discrimination and probability of exclusion in the group were 0.99999999999940 and 0.9963, respectively. We analyzed the D A distance, interpopulation differentiations and population structure, conducted principal component analysis and neighbor-joining tree based on our studied group and 21 reference groups. The present results indicated that the studied Xinjiang Uigur group (represented our samples from the whole territory of Xinjiang Uigur Autonomous Region) had a close relationships with Urumchi Uigur (represented previously reported samples from Urumchi of Xinjiang) and Kazak groups. The present study may provide novel biological information for the study of population genetics, and can also increase our understanding of the genetic relationships between Xinjiang Uigur group and other groups.

Cancer morbidity among methyl isocyanate exposed long- term survivors and their offspring: a hospital-based five year descriptive study (2006 - 2011) and future directions to predict cancer risk in the affected population.

PubMed

Senthilkumar, Chinnu Sugavanam; Malla, Tahir Mohi-ud-Din; Sah, Nand Kishore; Ganesh, Narayanan

2011-01-01

The purpose of this study was to update both researchers and clinicians about the cancer incidence in methyl isocyanate (MIC) exposed long-term survivors and in their offspring, focusing on the etiological plausibility. In the time period 2006-2011, cancer morbidity was evaluated in the population surviving after exposure to (MIC) on December 3rd, 1984, in Bhopal. This descriptive study is based on hospital registration of 1261 cancer patients those are MIC gas victims and their subsequently born offspring. Morbidity status was studied on the basis of gender, age, organ and site with relative percentages. Cancers on specific sites, with special reference to breast (n=231) (18.31%), lung (n=103) (8.16%), tongue (n=103) (8.16%), buccal mucosa (n=94) (7.45%), cervix (n=72) (5.70%), and esophagus (n=68) (5.39%) were found in high proportions. Ovary (n=43) (3.40%), brain (n=42) (3.33%), larynx (n=40) (3.17%), non-Hodgkin's (n=31) (2.45%), gallbladder (n=29) (2.29%), stomach (n=28) (2.22%), head and neck (n=28) (2.22%), liver (n=27) (2.14%), acute lymphoid leukemia (n=24) (1.90%), rectum (n=20) (1.58%), colon (n=20) (1.58%), chronic myeloid leukemia (n=17) (1.34%), alveolus (n=17) (1.34%), Hodgkin's (n=14) (1.11%), uterus (n=14) (1.11%), multiple myeloma (n=14) (1.11%), and prostate (n=11) (0.87%) lesions were observed less frequently. Remarkably, gradual increase of cancers on different organs and sites were observed in the long- term survivors and their offspring. The present study observed some cancers which were not previously reported in this population. In addition, we also present the future research directions with systematic approaches to predict cancer risk in long-term survivors and their future generations. On the basis of this morbidity report, we suggest the need of biological surveillance through immune system biomonitoring and cytogenetic screening to predict the cancer risk in the MIC exposed population and their offspring.

Population-level analysis and validation of an individual-based cutthroat trout model

Treesearch

Steven F. Railsback; Bret C. Harvey; Roland H. Lamberson; Derek E. Lee; Claasen Nathan J.; Shuzo Yoshihara

2002-01-01

Abstract - An individual-based model of stream trout is analyzed by testing its ability to reproduce patterns of population-level behavior observed in real trout: (1) "self-thinning," a negative power relation between weight and abundance; (2) a "critical period" of density-dependent mortality in young-of-the-year; (3) high and age-speci...

Contrasting physiological responses to future ocean acidification among Arctic copepod populations.

PubMed

Thor, Peter; Bailey, Allison; Dupont, Sam; Calosi, Piero; Søreide, Janne E; De Wit, Pierre; Guscelli, Ella; Loubet-Sartrou, Lea; Deichmann, Ida M; Candee, Martin M; Svensen, Camilla; King, Andrew L; Bellerby, Richard G J

2018-01-01

Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognized as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid-base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis. In copepodites stage CIV, measured reaction norms of ingestion rate and metabolic rate showed severe reductions in ingestion and increased metabolic expenses in two populations from Svalbard (Kongsfjord and Billefjord) whereas no effects were observed in a population from the Disko Bay, West Greenland. At pH T 7.87, which has been predicted for the Svalbard west coast by year 2100, these changes resulted in reductions in scope for growth of 19% in the Kongsfjord and a staggering 50% in the Billefjord. Interestingly, these effects were not observed in stage CV copepodites from any of the three locations. It seems that CVs may be more tolerant to OA perhaps due to a general physiological reorganization to meet low intracellular pH during hibernation. Needless to say, the observed changes in the CIV stage will have serious implications for the C. glacialis population health status and growth around Svalbard. However, OA tolerant populations such as the one in the Disko Bay could help to alleviate severe effects in C. glacialis as a species. © 2017 John Wiley & Sons Ltd.

SunSmart: evaluation of a pilot school-based sun protection intervention in Hispanic early adolescents

PubMed Central

Miller, K. A.; Langholz, B. M.; Ly, T.; Harris, S. C.; Richardson, J. L.; Peng, D. H.; Cockburn, M. G.

2015-01-01

The incidence of melanoma is rising among Hispanic populations in the United States. The purpose of this study is to evaluate the impact of a pilot sun safety educational intervention conducted from 2006 to 2012 on Hispanic early adolescents in a high ultraviolet environment. Nineteen schools with high Hispanic enrollment were recruited from urban neighborhoods in Los Angeles. The analytic sample was restricted to students identifying as Hispanic or Latino (n = 777). A mixed effects linear model was used to test mean changes from pre- to posttest on students’ sun protection knowledge, attitudes and behaviors. Significant improvements were observed across several cognitive outcomes related to sun protection, including knowledge of and attitudes toward sun protection and self-efficacy to wear sunscreen. However, changes in sun protective behaviors were not achieved. Although some improvements were observed, future studies should identify the factors that motivate sun protection in this population and develop tailored prevention strategies, as improving the sun safe behaviors of Hispanic youths may aid in reducing the risk of melanoma in adulthood in this population. PMID:25801103

FRED (a Framework for Reconstructing Epidemic Dynamics): an open-source software system for modeling infectious diseases and control strategies using census-based populations.

PubMed

Grefenstette, John J; Brown, Shawn T; Rosenfeld, Roni; DePasse, Jay; Stone, Nathan T B; Cooley, Phillip C; Wheaton, William D; Fyshe, Alona; Galloway, David D; Sriram, Anuroop; Guclu, Hasan; Abraham, Thomas; Burke, Donald S

2013-10-08

Mathematical and computational models provide valuable tools that help public health planners to evaluate competing health interventions, especially for novel circumstances that cannot be examined through observational or controlled studies, such as pandemic influenza. The spread of diseases like influenza depends on the mixing patterns within the population, and these mixing patterns depend in part on local factors including the spatial distribution and age structure of the population, the distribution of size and composition of households, employment status and commuting patterns of adults, and the size and age structure of schools. Finally, public health planners must take into account the health behavior patterns of the population, patterns that often vary according to socioeconomic factors such as race, household income, and education levels. FRED (a Framework for Reconstructing Epidemic Dynamics) is a freely available open-source agent-based modeling system based closely on models used in previously published studies of pandemic influenza. This version of FRED uses open-access census-based synthetic populations that capture the demographic and geographic heterogeneities of the population, including realistic household, school, and workplace social networks. FRED epidemic models are currently available for every state and county in the United States, and for selected international locations. State and county public health planners can use FRED to explore the effects of possible influenza epidemics in specific geographic regions of interest and to help evaluate the effect of interventions such as vaccination programs and school closure policies. FRED is available under a free open source license in order to contribute to the development of better modeling tools and to encourage open discussion of modeling tools being used to evaluate public health policies. We also welcome participation by other researchers in the further development of FRED.

Living in isolation - population structure, reproduction, and genetic variation of the endangered plant species Dianthus gratianopolitanus (Cheddar pink).

PubMed

Putz, Christina M; Schmid, Christoph; Reisch, Christoph

2015-09-01

The endangered plant species Dianthus gratianopolitanus exhibits a highly fragmented distribution range comprising many isolated populations. Based upon this pattern of distribution, we selected a study region in Switzerland with a lower magnitude of isolation (Swiss Jura) and another study region in Germany with a higher degree of isolation (Franconian Jura). In each region, we chose ten populations to analyze population structure, reproduction, and genetic variation in a comparative approach. Therefore, we determined population density, cushion size, and cushion density to analyze population structure, investigated reproductive traits, including number of flowers, capsules, and germination rate, and analyzed amplified fragment length polymorphisms to study genetic variation. Population and cushion density were credibly higher in German than in Swiss populations, whereas reproductive traits and genetic variation within populations were similar in both study regions. However, genetic variation among populations and isolation by distance were stronger in Germany than in Switzerland. Generally, cushion size and density as well as flower and capsule production increased with population size and density, whereas genetic variation decreased with population density. In contrast to our assumptions, we observed denser populations and cushions in the region with the higher magnitude of isolation, whereas reproductive traits and genetic variation within populations were comparable in both regions. This corroborates the assumption that stronger isolation must not necessarily result in the loss of fitness and genetic variation. Furthermore, it supports our conclusion that the protection of strongly isolated populations contributes essentially to the conservation of a species' full evolutionary potential.

A Population-Based Assessment of the Agreement Between Grading of Goniophotographic Images and Gonioscopy in the Chinese-American Eye Study (CHES)

PubMed Central

Murakami, Yohko; Wang, Dandan; Burkemper, Bruce; Lin, Shan C.; Varma, Rohit

2016-01-01

Purpose To compare grading of goniophotographic images and gonioscopy in assessing the iridocorneal angle. Methods In a population-based, cross-sectional study, participants underwent gonioscopy and goniophotographic imaging during the same visit. The iridocorneal angle was classified as closed if the posterior trabecular meshwork could not be seen. A single masked observer graded the goniophotographic images, and each eye was classified as having angle closure based on the number of closed quadrants. Agreement between the methods was analyzed by calculating kappa (κ) and first-order agreement coefficient (AC1) statistics and comparison of area under receiver operating characteristic curves (AUC). Results A total of 4149 Chinese Americans (3994 eyes) were included in this study. The agreement for angle closure diagnosis between gonioscopy and EyeCam was moderate to excellent (κ = 0.60, AC1 0.90, AUC 0.76–0.80). Conclusions Detection of iridocorneal angle closure based on goniophotographic imaging shows moderate to very good agreement with angle closure assessment using gonioscopy. PMID:27571018

Near-infrared spectroscopy of post-starburst galaxies: a limited impact of TP-AGB stars on galaxy spectral energy distributions

NASA Astrophysics Data System (ADS)

Zibetti, Stefano; Gallazzi, Anna; Charlot, Stéphane; Pierini, Daniele; Pasquali, Anna

2013-01-01

We present Very Large Telescope Infrared Spectrometer And Array Camera (ISAAC) near-infrared (NIR) spectrophotometric observations of 16 post-starburst galaxies aimed at constraining the debated influence of thermally pulsing asymptotic giant branch (TP-AGB) stars on the spectral energy distribution (SED) of galaxies with stellar ages between 0.5 and 2 Gyr, hence critical for high-redshift studies. Post-starburst galaxies are characterized by negligible ongoing star formation and a SED dominated by the stellar population formed in a recent (<2 Gyr) burst. By selecting post-starburst galaxies with mean luminosity-weighted ages between 0.5 and 1.5 Gyr and a broad range of metallicities (based on Sloan Digital Sky Survey optical spectroscopy), we explore the parameter space over which the relative energy output of TP-AGB stars peaks. A key feature of the present study is that we target galaxies at z ≈ 0.2, so that two main spectral features of TP-AGB stars (C-molecule band-head drops at 1.41 and 1.77 μm, blended with strong telluric absorption features, hence hardly observable from the ground, for targets at z ≈ 0) move inside the H and K atmospheric windows and can be constrained for the first time to high accuracy. Our observations provide key constraints to stellar population synthesis models. Our main results are (i) the NIR regions around 1.41 and 1.77 μm (rest frame) are featureless for all galaxies in our sample over the whole range of relevant ages and metallicities at variance with the Maraston `TP-AGB heavy' models, which exhibit marked drops there, and (ii) no flux boosting is observed in the NIR. The optical-NIR SEDs of most of our post-starburst galaxies can be consistently reproduced with the 2003 version of the Bruzual & Charlot models, using either simple stellar populations of corresponding light-weighted ages and metallicities or a more realistic burst plus an underlying old population containing up to approximately 60 per cent of the total stellar mass. In contrast, all combinations of this kind based on the Maraston models are unable to simultaneously reproduce the smoothness of the NIR spectra and the relatively blue optical-NIR colours in the observations. The data collected in this study appear to disfavour `TP-AGB heavy' models with respect to `TP-AGB light' ones.

Mental illness and a high-risk, elderly Japanese population: characteristic differences related to gender and residential location.

PubMed

Kikuchi, Hiroyuki; Takamiya, Tomoko; Odagiri, Yuko; Ohya, Yumiko; Shimomitsu, Teruichi; Inoue, Shigeru

2013-12-01

Examining the sociodemographic determinants of psychological distress is important in identifying specific subgroups in need of further intervention. However, there are few studies focusing on older populations and on the role of gender or location of residence. To try to clarify characteristics of a population at high risk for mental illness, we examined the sociodemographic determinants of psychological distress in older adults living in three different locations. A mail survey was used to collect data on levels of psychological distress and sociodemographic characteristics from a population-based sample of 1894 older adults who lived in Bunkyo (urban setting), Fuchu (suburban setting) and Oyama (rural setting) in Japan (aged 65-74 years, 51.3% men). Psychological distress level was measured based on Kessler's six-item psychological distress scale (K6) and dichotomized into two groups with a cut-off score of 5 (0-4 or 5-24). Multiple logistic regression analyses were used to examine the associations between sociodemographic factors, specifically gender and location of residence, and psychological distress levels. The variables of older age, living in Bunkyo, living in Oyama and living alone were significantly associated with high psychological distress. Although these associations were observed in men, no associations were observed in women. Location-specific analyses showed significant associations between sociodemographic and psychological distress among men living in Oyama, but not among those in Bunkyo or Fuchu. Sociodemographic factors were significantly correlated with psychological distress, particularly among older men in rural areas. Characteristics of a population at high risk for mental illness may vary based on gender and location of residence. Health promotion initiatives for older adults may be more effective if they take these demographic factors into account. © 2013 The Authors. Psychogeriatrics © 2013 Japanese Psychogeriatric Society.

Inverse Association Between Gluteofemoral Obesity and Risk of Barrett's Esophagus in a Pooled Analysis.

PubMed

Kendall, Bradley J; Rubenstein, Joel H; Cook, Michael B; Vaughan, Thomas L; Anderson, Lesley A; Murray, Liam J; Shaheen, Nicholas J; Corley, Douglas A; Chandar, Apoorva K; Li, Li; Greer, Katarina B; Chak, Amitabh; El-Serag, Hashem B; Whiteman, David C; Thrift, Aaron P

2016-10-01

Gluteofemoral obesity (determined by measurement of subcutaneous fat in the hip and thigh regions) could reduce risks of cardiovascular and diabetic disorders associated with abdominal obesity. We evaluated whether gluteofemoral obesity also reduces the risk of Barrett's esophagus (BE), a premalignant lesion associated with abdominal obesity. We collected data from non-Hispanic white participants in 8 studies in the Barrett's and Esophageal Adenocarcinoma Consortium. We compared measures of hip circumference (as a proxy for gluteofemoral obesity) from cases of BE (n = 1559) separately with 2 control groups: 2557 population-based controls and 2064 individuals with gastroesophageal reflux disease (GERD controls). Study-specific odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated using individual participant data and multivariable logistic regression and combined using a random-effects meta-analysis. We found an inverse relationship between hip circumference and BE (OR per 5-cm increase, 0.88; 95% CI, 0.81-0.96), compared with population-based controls in a multivariable model that included waist circumference. This association was not observed in models that did not include waist circumference. Similar results were observed in analyses stratified by frequency of GERD symptoms. The inverse association with hip circumference was statistically significant only among men (vs population-based controls: OR, 0.85; 95% CI, 0.76-0.96 for men; OR, 0.93; 95% CI, 0.74-1.16 for women). For men, within each category of waist circumference, a larger hip circumference was associated with a decreased risk of BE. Increasing waist circumference was associated with an increased risk of BE in the mutually adjusted population-based and GERD control models. Although abdominal obesity is associated with an increased risk of BE, there is an inverse association between gluteofemoral obesity and BE, particularly among men. Copyright © 2016 AGA Institute. Published by Elsevier Inc. All rights reserved.

Resilience and tipping points of an exploited fish population over six decades.

PubMed

Vasilakopoulos, Paraskevas; Marshall, C Tara

2015-05-01

Complex natural systems with eroded resilience, such as populations, ecosystems and socio-ecological systems, respond to small perturbations with abrupt, discontinuous state shifts, or critical transitions. Theory of critical transitions suggests that such systems exhibit fold bifurcations featuring folded response curves, tipping points and alternate attractors. However, there is little empirical evidence of fold bifurcations occurring in actual complex natural systems impacted by multiple stressors. Moreover, resilience of complex systems to change currently lacks clear operational measures with generic application. Here, we provide empirical evidence for the occurrence of a fold bifurcation in an exploited fish population and introduce a generic measure of ecological resilience based on the observed fold bifurcation attributes. We analyse the multivariate development of Barents Sea cod (Gadus morhua), which is currently the world's largest cod stock, over six decades (1949-2009), and identify a population state shift in 1981. By plotting a multivariate population index against a multivariate stressor index, the shift mechanism was revealed suggesting that the observed population shift was a nonlinear response to the combined effects of overfishing and climate change. Annual resilience values were estimated based on the position of each year in relation to the fitted attractors and assumed tipping points of the fold bifurcation. By interpolating the annual resilience values, a folded stability landscape was fit, which was shaped as predicted by theory. The resilience assessment suggested that the population may be close to another tipping point. This study illustrates how a multivariate analysis, supported by theory of critical transitions and accompanied by a quantitative resilience assessment, can clarify shift mechanisms in data-rich complex natural systems. © 2014 John Wiley & Sons Ltd.

ERAP1 variants are associated with ankylosing spondylitis in East Asian population: a new Chinese case-control study and meta-analysis of published series.

PubMed

Chen, C; Zhang, X

2015-06-01

Endoplasmic reticulum aminopeptidase 1 (ERAP1) has been confirmed to be associated with ankylosing spondylitis (AS) in Caucasian. However, whether they are associated with AS in East Asian population remains unidentified. We investigated this relationship by a new Chinese case-control study and a meta-analysis of published series. 368 cases and 460 controls were recruited in the Chinese case-control study. Genotyping was completed using the chip-based matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Allelic associations were analysed using contingency tables. In the meta-analysis, up to 2748 cases and 2774 controls from seven different studies and the new Chinese study were combined using Review Manager software version 5.1.1. Mantel-Haenszel or Inverse Variance test was used to calculate fixed or random-effects pooled ORs. In the new Chinese study, strong association with AS was observed for marker rs10050860, rs27434 and rs1065407 at P value of <0.001. Moderate association was observed for rs30187 at P value of <0.01, while no association was observed for rs27044 (P = 0.37) and rs2287987 (P = 0.23). The meta-analysis showed that rs27037 and rs30187 were strongly associated with AS (P < 0.00001). Significant association was also observed for rs27434 (P = 0.001). No association was shown for rs27044 (P = 0.70). We concluded that ERAP1 variants are associated with AS in East Asian population, indicating a common pathogenic mechanism for AS in East Asians and Caucasians. © 2015 John Wiley & Sons Ltd.

The temporal spectrum of adult mosquito population fluctuations: conceptual and modeling implications.

PubMed

Jian, Yun; Silvestri, Sonia; Brown, Jeff; Hickman, Rick; Marani, Marco

2014-01-01

An improved understanding of mosquito population dynamics under natural environmental forcing requires adequate field observations spanning the full range of temporal scales over which mosquito abundance fluctuates in natural conditions. Here we analyze a 9-year daily time series of uninterrupted observations of adult mosquito abundance for multiple mosquito species in North Carolina to identify characteristic scales of temporal variability, the processes generating them, and the representativeness of observations at different sampling resolutions. We focus in particular on Aedes vexans and Culiseta melanura and, using a combination of spectral analysis and modeling, we find significant population fluctuations with characteristic periodicity between 2 days and several years. Population dynamical modelling suggests that the observed fast fluctuations scales (2 days-weeks) are importantly affected by a varying mosquito activity in response to rapid changes in meteorological conditions, a process neglected in most representations of mosquito population dynamics. We further suggest that the range of time scales over which adult mosquito population variability takes place can be divided into three main parts. At small time scales (indicatively 2 days-1 month) observed population fluctuations are mainly driven by behavioral responses to rapid changes in weather conditions. At intermediate scales (1 to several month) environmentally-forced fluctuations in generation times, mortality rates, and density dependence determine the population characteristic response times. At longer scales (annual to multi-annual) mosquito populations follow seasonal and inter-annual environmental changes. We conclude that observations of adult mosquito populations should be based on a sub-weekly sampling frequency and that predictive models of mosquito abundance must include behavioral dynamics to separate the effects of a varying mosquito activity from actual changes in the abundance of the underlying population.

The structural and functional connectivity of the grassland plant Lychnis flos-cuculi

PubMed Central

Aavik, T; Holderegger, R; Bolliger, J

2014-01-01

Understanding the relationship between structural and functional connectivity is essential for successful restoration and conservation management, particularly in intensely managed agricultural landscapes. We evaluated the relationship between structural and functional connectivity of the wetland plant Lychnis flos-cuculi in a fragmented agricultural landscape using landscape genetic and network approaches. First, we studied the effect of structural connectivity, such as geographic distance and various landscape elements (forest, agricultural land, settlements and ditch verges), on gene flow among populations as a measurement of functional connectivity. Second, we examined the effect of structural graph-theoretic connectivity measures on gene flow among populations and on genetic diversity within populations of L. flos-cuculi. Among landscape elements, forests hindered gene flow in L. flos-cuculi, whereas gene flow was independent of geographic distance. Among the structural graph-theoretic connectivity variables, only intrapopulation connectivity, which was based on population size, had a significant positive effect on gene flow, that is, more gene flow took place among larger populations. Unexpectedly, interpopulation connectivity of populations, which takes into account the spatial location and distance among populations, did not influence gene flow in L. flos-cuculi. However, higher observed heterozygosity and lower inbreeding was observed in populations characterised by higher structural interpopulation connectivity. This finding shows that a spatially coherent network of populations is significant for maintaining the genetic diversity of populations. Nevertheless, lack of significant relationships between gene flow and most of the structural connectivity measures suggests that structural connectivity does not necessarily correspond to functional connectivity. PMID:24253937

The association between continuous positive airway pressure therapy and liver disease development in obstructive sleep apnea/hypopnea syndrome patients: a nationwide population-based cohort study in Taiwan.

PubMed

Hang, Liang-Wen; Chen, Chi-Fung; Wang, Chang-Bi; Wu, Trong-Neng; Liang, Wen-Miin; Chou, Tzu-Chieh

2017-05-01

Studies on the association between continuous positive airway pressure (CPAP) treatment and liver diseases such as non-alcoholic fatty liver disease (NAFLD) and cirrhosis in patients with obstructive sleep apnea/hypopnea syndrome (OSAHS) are limited. To the best of our knowledge, none exists that makes use of a national database in an Asian population. This study aims to evaluate the effects of CPAP treatment on patients with these two disorders in a retrospective, population-based study in Taiwan. Using the Taiwan National Health Insurance claims database, this study collected the data of OSAHS patients diagnosed between 2000 and 2008 and divided them into CPAP treatment and non-CPAP treatment groups. All subjects were followed up until 2010. Liver disease incidence and risk were calculated. The CPAP group had a lower cumulative incidence rate of developing liver disease than the non-CPAP group within the observation periods (p < 0.001). After adjusting for age, gender, urbanization level, and comorbidities, the CPAP treatment group showed a lower risk of developing liver disease compared with the non-CPAP treatment group (sub-aHR of 0.66 (95% CI 0.55-0.80), p < 0.001). Our observations suggest that CPAP treatment may play an important role to delay the progression of liver disease in OSAHS patients and decreases the incidence of liver disease among OSAHS patients. Thus, CPAP therapy may be a feasible way to decrease the risk of liver disease among patients with OSAHS.

A review of Human Biomonitoring studies of trace elements in Pakistan.

PubMed

Waseem, Amir; Arshad, Jahanzaib

2016-11-01

Human biomonitoring (HBM) measures the concentration levels of substances or their metabolites in human body fluids and tissues. HBM of dose and biochemical effect monitoring is an effective way of measuring human exposure to chemical substances. Many countries have conducted HBM studies to develop a data base for many chemicals including trace metals of health concern for their risk assessment and risk management. However, in Pakistan, HBM program on large scale for general population does not exist at present or in the past has been reported. Various individual HBM studies have been reported on the assessment of trace elements (usually heavy metals) from Pakistan; most of them are epidemiological cross sectional surveys. In this current review we tried to develop a data base of HBM studies of trace elements namely arsenic, cadmium, copper, chromium, iron, lead, manganese, nickel, and zinc in biological fluids (blood, urine) and tissues (hair, nails) in general population of Pakistan. Studies from all available sources have been explored, discussed and presented in the form of tables and figures. The results of these studies were critically compared with large scale HBM programs of other countries, (US & European communities etc). It was observed from the present study that the most of the toxic metals in biological fluids/tissues in general population of Pakistan, have higher background values comparatively. For example the mean values of toxic metals like As, Cd, Cr, Ni, and Pb in blood of general population were found as 2.08 μg/L, 4.24 μg/L, 60.5 μg/L, 1.95 μg/L, 198 μg/L respectively. Similarly, the urine mean values of 67.6 μg/L, 3.2 μg/L, 16.4 μg/L, 6.2 μg/L and 86.5 μg/L were observed for As, Cd, Cr, Ni, and Pb respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Demographic and health situation of children in conditions of economic destabilization in the Ukraine.

PubMed

Pantyley, Viktoriya

2014-01-01

In new conditions of socio-economic development in the Ukraine, the health of the population of children is considered as the most reliable indicator of socio-economic development of the country. The primary goal of the study was analysis of the effect of contemporary socio-economic transformations, their scope, and strength of effect on the demographic and social situation of children in various regions of the Ukraine. The methodological objectives of the study were as follows: development of a synthetic measure of the state of health of the population of children, based on the Hellwig's method, and selection of districts in the Ukraine according to the present health-demographic situation of children. The study was based on statistical data from the State Statistics Service of Ukraine, Centre of Medical Statistics in Kiev, Ukrainian Ministry of Defence, as well as Ministry of Education and Science, Youth and Sports of Ukraine. The following research methods were used: analysis of literature and Internet sources, selection and analysis of statistical materials, cartographic and statistical methods. Basic indices of the demographic and health situation of the population of children were analyzed, as well as factors of a socio-economic nature which affect this situation. A set of variables was developed for the synthetic evaluation of the state of health of the population of children. The typology of the Ukrainian districts was performed according to the state of health of the child population, based on the Hellwig's taxonomic method. Deterioration was observed of selected quality parameters, as well as a change in the strength and directions of effect of factors of organizational-institutional, socioeconomic, historical and cultural nature on the population of children potential.

Incidence of type 2 diabetes in Mexico: results of the Mexico City Diabetes Study after 18 years of follow-up.

PubMed

González-Villalpando, Clicerio; Dávila-Cervantes, Claudio Alberto; Zamora-Macorra, Mireya; Trejo-Valdivia, Belem; González-Villalpando, María Elena

2014-01-01

To estimate the incidence of type 2 diabetes (T2D) in Mexican population. Population based prospective study. At baseline (1990), the population at risk (1939 non-diabetic adults 35-64 years) was evaluated with oral glucose tolerance test. Subsequent similar evaluations were done (1994, 1998, 2008). American Diabetes Association diagnostic criteria were applied. The period of observation was 27842 person-years, the cumulative incidence of T2D was 14.4 and 13.7 per 1000 person-years for men and women, respectively. Incidence was 15.8, 15.7 and 12.7 per 1 000 person-years for the second (1994), third (1998) and fourth (2008) follow-up phases, respectively. The mean age at diagnosis was 44 years for prevalent cases and 56 years for incident cases. This is the first estimate of long-term incidence of T2D in Mexican population. The incidence is among the highest reported worldwide. It remained with few changes throughout the study period.

Exploitation of immunofluorescence for the quantification and characterization of small numbers of Pasteuria endospores.

PubMed

Costa, Sofia R; Kerry, Brian R; Bardgett, Richard D; Davies, Keith G

2006-12-01

The Pasteuria group of endospore-forming bacteria has been studied as a biocontrol agent of plant-parasitic nematodes. Techniques have been developed for its detection and quantification in soil samples, and these mainly focus on observations of endospore attachment to nematodes. Characterization of Pasteuria populations has recently been performed with DNA-based techniques, which usually require the extraction of large numbers of spores. We describe a simple immunological method for the quantification and characterization of Pasteuria populations. Bayesian statistics were used to determine an extraction efficiency of 43% and a threshold of detection of 210 endospores g(-1) sand. This provided a robust means of estimating numbers of endospores in small-volume samples from a natural system. Based on visual assessment of endospore fluorescence, a quantitative method was developed to characterize endospore populations, which were shown to vary according to their host.

Primary care physician supply and other key determinants of health care utilisation: the case of Switzerland

PubMed Central

Busato, André; Künzi, Beat

2008-01-01

Background The Swiss government decided to freeze new accreditations for physicians in private practice in Switzerland based on the assumption that demand-induced health care spending may be cut by limiting care offers. This legislation initiated an ongoing controversial public debate in Switzerland. The aim of this study is therefore the determination of socio-demographic and health system-related factors of per capita consultation rates with primary care physicians in the multicultural population of Switzerland. Methods The data were derived from the complete claims data of Swiss health insurers for 2004 and included 21.4 million consultations provided by 6564 Swiss primary care physicians on a fee-for-service basis. Socio-demographic data were obtained from the Swiss Federal Statistical Office. Utilisation-based health service areas were created and were used as observational units for statistical procedures. Multivariate and hierarchical models were applied to analyze the data. Results Models within the study allowed the definition of 1018 primary care service areas with a median population of 3754 and an average per capita consultation rate of 2.95 per year. Statistical models yielded significant effects for various geographical, socio-demographic and cultural factors. The regional density of physicians in independent practice was also significantly associated with annual consultation rates and indicated an associated increase 0.10 for each additional primary care physician in a population of 10,000 inhabitants. Considerable differences across Swiss language regions were observed with reference to the supply of ambulatory health resources provided either by primary care physicians, specialists, or hospital-based ambulatory care. Conclusion The study documents a large small-area variation in utilisation and provision of health care resources in Switzerland. Effects of physician density appeared to be strongly related to Swiss language regions and may be rooted in the different cultural backgrounds of the served populations. PMID:18190705

Survival in pediatric medulloblastoma: a population-based observational study to improve prognostication.

PubMed

Weil, Alexander G; Wang, Anthony C; Westwick, Harrison J; Ibrahim, George M; Ariani, Rojine T; Crevier, Louis; Perreault, Sebastien; Davidson, Tom; Tseng, Chi-Hong; Fallah, Aria

2017-03-01

Medulloblastoma is the most common form of brain malignancy of childhood. The mainstay of epidemiological data regarding childhood medulloblastoma is derived from case series, hence population-based studies are warranted to improve the accuracy of survival estimates. To utilize a big-data approach to update survival estimates in a contemporary cohort of children with medulloblastoma. We performed a population-based retrospective observational cohort study utilizing the Surveillance, Epidemiology, and End Results Program database that captures all children, less than 20 years of age, between 1973 and 2012 in 18 geographical regions representing 28% of the US population. We included all participants with a presumed or histologically diagnosis of medulloblastoma. The main outcome of interest is survivors at 1, 5 and 10 years following diagnosis. A cohort of 1735 children with a median (interquartile range) age at diagnosis of 7 (4-11) years, with a diagnosis of medulloblastoma were identified. The incidence and prevalence of pediatric medulloblastoma has remained stable over the past 4 decades. There is a critical time point at 1990 when the overall survival has drastically improved. In the contemporary cohort (1990 onwards), the percentage of participants alive was 86, 70 and 63% at 1, 5 and 10 years, respectively. Multivariate Cox-Regression model demonstrated Radiation (HR 0.37; 95% CI 0.30-0.46, p < 0.001) and Surgery (HR 0.42; 95% CI 0.30-0.58, p < 0.001) independently predict survival. The probability of mortality from a neurological cause is <5% in patients who are alive 8 years following diagnosis. The SEER cohort analysis demonstrates significant improvements in pediatric medulloblastoma survival. In contrast to previous reports, the majority of patients survive in the modern era, and those alive 8 years following initial diagnosis are likely a long-term survivor. The importance of minimizing treatment-related toxicity is increasingly apparent given the likelihood of long-term survival.

A Population-based Case–Control Study of Urinary Arsenic Species and Squamous Cell Carcinoma in New Hampshire, USA

PubMed Central

Li, Zhigang; Perry, Ann E.; Spencer, Steven K.; Gandolfi, A. Jay; Karagas, Margaret R.

2013-01-01

Background: Chronic high arsenic exposure is associated with squamous cell carcinoma (SCC) of the skin, and inorganic arsenic (iAs) metabolites may play an important role in this association. However, little is known about the carcinogenicity of arsenic at levels commonly observed in the United States. Objective: We estimated associations between total urinary arsenic and arsenic species and SCC in a U.S. population. Methods: We conducted a population-based case–control SCC study (470 cases, 447 controls) in a U.S. region with moderate arsenic exposure through private well water and diet. We measured urinary iAs, monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA), and summed these arsenic species (ΣAs). Because seafood contains arsenolipids and arsenosugars that metabolize into DMA through alternate pathways, participants who reported seafood consumption within 2 days before urine collection were excluded from the analyses. Results: In adjusted logistic regression analyses (323 cases, 319 controls), the SCC odds ratio (OR) was 1.37 for each ln-transformed microgram per liter increase in ln-transformed ΣAs concentration [ln(ΣAs)] (95% CI: 1.04, 1.80). Urinary ln(MMA) and ln(DMA) also were positively associated with SCC (OR = 1.34; 95% CI: 1.04, 1.71 and OR = 1.34; 95% CI: 1.03, 1.74, respectively). A similar trend was observed for ln(iAs) (OR = 1.20; 95% CI: 0.97, 1.49). Percent iAs, MMA, and DMA were not associated with SCC. Conclusions: These results suggest that arsenic exposure at levels common in the United States relates to SCC and that arsenic metabolism ability does not modify the association. Citation: Gilbert-Diamond D, Li Z, Perry AE, Spencer SK, Gandolfi AJ, Karagas MR. 2013. A population-based case–control study of urinary arsenic species and squamous cell carcinoma in New Hampshire, USA. Environ Health Perspect 121:1154–1160; http://dx.doi.org/10.1289/ehp.1206178 PMID:23872349

Primary care physician supply and other key determinants of health care utilisation: the case of Switzerland.

PubMed

Busato, André; Künzi, Beat

2008-01-11

The Swiss government decided to freeze new accreditations for physicians in private practice in Switzerland based on the assumption that demand-induced health care spending may be cut by limiting care offers. This legislation initiated an ongoing controversial public debate in Switzerland. The aim of this study is therefore the determination of socio-demographic and health system-related factors of per capita consultation rates with primary care physicians in the multicultural population of Switzerland. The data were derived from the complete claims data of Swiss health insurers for 2004 and included 21.4 million consultations provided by 6564 Swiss primary care physicians on a fee-for-service basis. Socio-demographic data were obtained from the Swiss Federal Statistical Office. Utilisation-based health service areas were created and were used as observational units for statistical procedures. Multivariate and hierarchical models were applied to analyze the data. Models within the study allowed the definition of 1018 primary care service areas with a median population of 3754 and an average per capita consultation rate of 2.95 per year. Statistical models yielded significant effects for various geographical, socio-demographic and cultural factors. The regional density of physicians in independent practice was also significantly associated with annual consultation rates and indicated an associated increase 0.10 for each additional primary care physician in a population of 10,000 inhabitants. Considerable differences across Swiss language regions were observed with reference to the supply of ambulatory health resources provided either by primary care physicians, specialists, or hospital-based ambulatory care. The study documents a large small-area variation in utilisation and provision of health care resources in Switzerland. Effects of physician density appeared to be strongly related to Swiss language regions and may be rooted in the different cultural backgrounds of the served populations.

Untapped Potential of Observational Research to Inform Clinical Decision Making: American Society of Clinical Oncology Research Statement.

PubMed

Visvanathan, Kala; Levit, Laura A; Raghavan, Derek; Hudis, Clifford A; Wong, Sandra; Dueck, Amylou; Lyman, Gary H

2017-06-01

ASCO believes that high-quality observational studies can advance evidence-based practice for cancer care and are complementary to randomized controlled trials (RCTs). Observational studies can generate hypotheses by evaluating novel exposures or biomarkers and by revealing patterns of care and relationships that might not otherwise be discovered. Researchers can then test these hypotheses in RCTs. Observational studies can also answer or inform questions that either have not been or cannot be answered by RCTs. In addition, observational studies can be used for postmarketing surveillance of new cancer treatments, particularly in vulnerable populations. The incorporation of observational research as part of clinical decision making is consistent with the position of many leading institutions. ASCO identified five overarching recommendations to enhance the role of observational research in clinical decision making: (1) improve the quality of electronic health data available for research, (2) improve interoperability and the exchange of electronic health information, (3) ensure the use of rigorous observational research methodologies, (4) promote transparent reporting of observational research studies, and (5) protect patient privacy.

Mental health differences between German gay and bisexual men and population-based controls.

PubMed

Sattler, Frank A; Franke, Gabriele H; Christiansen, Hanna

2017-07-21

International studies have revealed that gay and bisexual men present more mental health problems than the general male population. Furthermore, there is evidence that minority stress predicts mental health problems in gay and bisexual men. The aim of the present study is to provide initial data on mental health differences in Germany and to analyze the effect of minority stress. Mental health data on n = 1903 German gay and bisexual men and n = 958 men from a population-based sample were assessed using a shortened version of the SCL-90-S. The mental health of the two samples was compared. Furthermore, a linear regression was conducted for the gay and bisexual sample: mental health was used as the criterion and minority stressors as predictors. As compared to our population sample, gay and bisexual men demonstrated more mental health problems with a moderate effect size. In the regression, minority stress predicted mental health problems in the gay and bisexual sample. We observed pronounced mental health differences between gay and bisexual men versus the population sample. These differences could be at least partly due to the minority stress gay and bisexual men face. Research should focus on how to reduce and cope with minority stress.

Estimating population size for Capercaillie (Tetrao urogallus L.) with spatial capture-recapture models based on genotypes from one field sample

USGS Publications Warehouse

Mollet, Pierre; Kery, Marc; Gardner, Beth; Pasinelli, Gilberto; Royle, Andy

2015-01-01

We conducted a survey of an endangered and cryptic forest grouse, the capercaillie Tetrao urogallus, based on droppings collected on two sampling occasions in eight forest fragments in central Switzerland in early spring 2009. We used genetic analyses to sex and individually identify birds. We estimated sex-dependent detection probabilities and population size using a modern spatial capture-recapture (SCR) model for the data from pooled surveys. A total of 127 capercaillie genotypes were identified (77 males, 46 females, and 4 of unknown sex). The SCR model yielded atotal population size estimate (posterior mean) of 137.3 capercaillies (posterior sd 4.2, 95% CRI 130–147). The observed sex ratio was skewed towards males (0.63). The posterior mean of the sex ratio under the SCR model was 0.58 (posterior sd 0.02, 95% CRI 0.54–0.61), suggesting a male-biased sex ratio in our study area. A subsampling simulation study indicated that a reduced sampling effort representing 75% of the actual detections would still yield practically acceptable estimates of total size and sex ratio in our population. Hence, field work and financial effort could be reduced without compromising accuracy when the SCR model is used to estimate key population parameters of cryptic species.

Correlation between mean body mass index in the population and prevalence of obesity in Brazilian capitals: empirical evidence for a population-based approach of obesity.

PubMed

Lobato, Jackeline Christiane Pinto; Kale, Pauline Lorena; Velarde, Luis Guillermo Coca; Szklo, Moyses; Costa, Antonio José Leal

2015-04-02

The purpose of this study was to investigate the association between mean body mass index (BMI) and prevalence of obesity in adult populations living in Brazilian State capitals. An ecological study was conducted, using data from the National Household Budget Survey conducted in July 2002 through June 2003, including a representative sample of 48.470 households. Pearson's correlation and linear regression coefficients were estimated in order to define the relationships of mean BMI and sex-specific, age standardized obesity prevalence (BMI ≥ 30.0 kg/m(2)) in adults aged 20 to 59 years. Stronger correlations between BMI and prevalence of obesity were observed in women (r = 0.9; p < 0.001) than in men (r = 0.6; p = 0.001) in all analyzes. A reduction of one unit in mean BMI predicted a decline in the prevalence of obesity of about 4.0% (95% CI: 1.7-6.3) in men, and 3.4% (95% CI: 2.6-4.3) in women. We found a correlation between BMI and prevalence of obesity, particularly among women, suggesting that population-based strategies would be effective to reduce the prevalence of obesity in adult populations living in Brazilian state capitals.

Estimating population genetic parameters and comparing model goodness-of-fit using DNA sequences with error

PubMed Central

Liu, Xiaoming; Fu, Yun-Xin; Maxwell, Taylor J.; Boerwinkle, Eric

2010-01-01

It is known that sequencing error can bias estimation of evolutionary or population genetic parameters. This problem is more prominent in deep resequencing studies because of their large sample size n, and a higher probability of error at each nucleotide site. We propose a new method based on the composite likelihood of the observed SNP configurations to infer population mutation rate θ = 4Neμ, population exponential growth rate R, and error rate ɛ, simultaneously. Using simulation, we show the combined effects of the parameters, θ, n, ɛ, and R on the accuracy of parameter estimation. We compared our maximum composite likelihood estimator (MCLE) of θ with other θ estimators that take into account the error. The results show the MCLE performs well when the sample size is large or the error rate is high. Using parametric bootstrap, composite likelihood can also be used as a statistic for testing the model goodness-of-fit of the observed DNA sequences. The MCLE method is applied to sequence data on the ANGPTL4 gene in 1832 African American and 1045 European American individuals. PMID:19952140

Population and forensic data for three sets of forensic genetic markers in four ethnic groups from Iran: Persians, Lurs, Kurds and Azeris.

PubMed

Poulsen, L; Farzad, M Sharafi; Børsting, C; Tomas, C; Pereira, V; Morling, N

2015-07-01

A total of 255 individuals (Persians, Lurs, Kurds and Azeris) from Iran were typed for three sets of forensic genetic markers with the NGM SElect™, DIPplex(®) and Argus X-12 kits. Statistically significant deviations (P≤0.002) from Hardy-Weinberg expectations were observed for the insertion-deletion markers HLD97 and HLD93 after Holm-Šidák correction. Statistically significant (P<0.05) levels of linkage disequilibrium were observed between markers within two of the four studied X-chromosomal linkage groups. AMOVA analyses of the three sets of markers did not show population structure when the individuals were grouped according to their ethnic group. The Iranian population grouped closely to populations living geographically near to Iran based on pairwise FST distances. The matching probabilities ranged from 1 in 3.2×10(7) males by using haplotype frequencies of four X-chromosomal haplogroups to 1 in 3.4×10(21) individuals for the 16 autosomal STRs. Copyright © 2015. Published by Elsevier Ireland Ltd.

Integrating 400 million variants from 80,000 human samples with extensive annotations: towards a knowledge base to analyze disease cohorts.

PubMed

Hakenberg, Jörg; Cheng, Wei-Yi; Thomas, Philippe; Wang, Ying-Chih; Uzilov, Andrew V; Chen, Rong

2016-01-08

Data from a plethora of high-throughput sequencing studies is readily available to researchers, providing genetic variants detected in a variety of healthy and disease populations. While each individual cohort helps gain insights into polymorphic and disease-associated variants, a joint perspective can be more powerful in identifying polymorphisms, rare variants, disease-associations, genetic burden, somatic variants, and disease mechanisms. We have set up a Reference Variant Store (RVS) containing variants observed in a number of large-scale sequencing efforts, such as 1000 Genomes, ExAC, Scripps Wellderly, UK10K; various genotyping studies; and disease association databases. RVS holds extensive annotations pertaining to affected genes, functional impacts, disease associations, and population frequencies. RVS currently stores 400 million distinct variants observed in more than 80,000 human samples. RVS facilitates cross-study analysis to discover novel genetic risk factors, gene-disease associations, potential disease mechanisms, and actionable variants. Due to its large reference populations, RVS can also be employed for variant filtration and gene prioritization. A web interface to public datasets and annotations in RVS is available at https://rvs.u.hpc.mssm.edu/.

Inverse association between dietary vitamin D and risk of cutaneous melanoma in a northern Italy population

PubMed Central

Vinceti, Marco; Malagoli, Carlotta; Fiorentini, Chiara; Longo, Caterina; Crespi, Catherine M.; Albertini, Giuseppe; Ricci, Cinzia; Lanzoni, Anna; Reggiani, Maurizio; Virgili, Annarosa; Osti, Federica; Lombardi, Mara; Santini, Marcello; Fanti, Pier Alessandro; Dika, Emi; Sieri, Sabina; Krogh, Vittorio; Seidenari, Stefania; Pellacani, Giovanni

2010-01-01

The possibility of an inverse association between vitamin D and risk of cancer and, in particular, of cutaneous malignant melanoma has been suggested, but results of epidemiologic studies are still conflicting. We examined the relation between dietary vitamin D intake and melanoma risk through a population-based case-control study (380 cases, 719 controls) in a northern region of Italy, a country with average vitamin D intake lower than in northern Europe or the US. We assessed average daily intake of vitamin D from foodstuffs using the European Prospective Investigation into Cancer and Nutrition (EPIC) semiquantitative food frequency questionnaire. In this population, levels of vitamin D intake were considerably lower than those observed in recent US studies. We found an inverse relation between dietary vitamin D and melanoma risk in the sample as a whole, in both crude and adjusted analyses. In sex and age-specific analyses, this association appeared to be stronger among males and among older subjects. These findings suggest that, at the relatively low levels of intake observed in this sample, an inverse relation between dietary vitamin D and risk of cutaneous malignant melanoma may exist. PMID:21541899

High-Level Genetic Diversity and Complex Population Structure of Siberian Apricot (Prunus sibirica L.) in China as Revealed by Nuclear SSR Markers

PubMed Central

Wang, Zhe; Kang, Ming; Liu, Huabo; Gao, Jiao; Zhang, Zhengdong; Li, Yingyue; Wu, Rongling; Pang, Xiaoming

2014-01-01

Siberian apricot (Prunus sibirica L.), an ecologically and economically important tree species with a high degree of tolerance to a variety of extreme environmental conditions, is widely distributed across the mountains of northeastern and northern China, eastern and southeastern regions of Mongolia, Eastern Siberia, and the Maritime Territory of Russia. However, few studies have examined the genetic diversity and population structure of this species. Using 31 nuclear microsatellites, we investigated the level of genetic diversity and population structure of Siberian apricot sampled from 22 populations across China. The number of alleles per locus ranged from 5 to 33, with an average of 19.323 alleles. The observed heterozygosity and expected heterozygosity ranged from 0.037 to 0.874 and 0.040 to 0.924 with average values of 0.639 and 0.774, respectively. A STRUCTURE-based analysis clustered all of the populations into four genetic clusters. Significant genetic differentiation was observed between all population pairs. A hierarchical analysis of molecular variance attributed about 94% of the variation to within populations. No significant difference was detected between the wild and semi-wild groups, indicating that recent cultivation practices have had little impact on the genetic diversity of Siberian apricot. The Mantel test showed that the genetic distance among the populations was not significantly correlated with geographic distance (r = 0.4651, p = 0.9940). Our study represents the most comprehensive investigation of the genetic diversity and population structure of Siberian apricot in China to date, and it provides valuable information for the collection of genetic resources for the breeding of Siberian apricot and related species. PMID:24516551

Epidemiology of prostate and kidney cancer in the Aboriginal population of Canada: A systematic review

PubMed Central

Wong, Emily Chu Lee; Kapoor, Anil

2017-01-01

Introduction Prostate and kidney cancer rates in the Aboriginal population of Canada is a growing issue. Methods A systematic review of prostate and kidney cancer epidemiology in the Aboriginal population of Canada was performed with international comparison and evaluation of present epidemiological disparities. PubMed, Medline, and Embase (from January 1946 to June 2016), relevant government-published reports, and the websites of organizations contributing to prostate or kidney cancer guidelines were searched. We included studies that informed any of the three epidemiological questions this review is focused on answering. Results Two systematic reviews, two meta-analyses, five literature reviews, and 21 single-study papers were included. The incidence and mortality rates of kidney cancer were elevated among Canadian Aboriginals when compared to the provincial or national population and to several international regions. No studies reported data on survival. Prostate cancer incidence, mortality, and survival rates were lower in Aboriginals provincially, nationally, and internationally, with incidence and survival reaching statistical significance. Elevated rate of risk factors for kidney cancer was a significant finding among Canadian Aboriginals. Aboriginals were screened for prostate cancer less than the general Canadian population, a trend also observed in the U.S. Conclusions The elevated incidence and mortality of kidney cancer among Canadian Aboriginals is most likely attributable to the rise in lifestyle-based risk factors. Two correlations concerning prostate cancer are made. However, due to temporal and regional disparities in data, further investigation is required to elucidate these observations. PMID:28503238

Cystic fibrosis carrier screening in a North American population.

PubMed

Zvereff, Val V; Faruki, Hawazin; Edwards, Marcia; Friedman, Kenneth J

2014-07-01

The aim of this study was to compare the mutation frequency distribution for a 32-mutation panel and a 69-mutation panel used for cystic fibrosis carrier screening. Further aims of the study were to examine the race-specific detection rates provided by both panels and to assess the performance of extended panels in large-scale, population-based cystic fibrosis carrier screening. Although genetic screening for the most common CFTR mutations allows detection of nearly 90% of cystic fibrosis carriers, the large number of other mutations, and their distribution within different ethnic groups, limits the utility of general population screening. Patients referred for cystic fibrosis screening from January 2005 through December 2010 were tested using either a 32-mutation panel (n = 1,601,308 individuals) or a 69-mutation panel (n = 109,830). The carrier frequencies observed for the 69-mutation panel study population (1/36) and Caucasian (1/27) and African-American individuals (1/79) agree well with published cystic fibrosis carrier frequencies; however, a higher carrier frequency was observed for Hispanic-American individuals (1/48) using the 69-mutation panel as compared with the 32-mutation panel (1/69). The 69-mutation panel detected ~20% more mutations than the 32-mutation panel for both African-American and Hispanic-American individuals. Expanded panels using race-specific variants can improve cystic fibrosis carrier detection rates within specific populations. However, it is important that the pathogenicity and the relative frequency of these variants are confirmed.

Development of a socio-ecological environmental justice model for watershed-based management

NASA Astrophysics Data System (ADS)

Sanchez, Georgina M.; Nejadhashemi, A. Pouyan; Zhang, Zhen; Woznicki, Sean A.; Habron, Geoffrey; Marquart-Pyatt, Sandra; Shortridge, Ashton

2014-10-01

The dynamics and relationships between society and nature are complex and difficult to predict. Anthropogenic activities affect the ecological integrity of our natural resources, specifically our streams. Further, it is well-established that the costs of these activities are born unequally by different human communities. This study considered the utility of integrating stream health metrics, based on stream health indicators, with socio-economic measures of communities, to better characterize these effects. This study used a spatial multi-factor model and bivariate mapping to produce a novel assessment for watershed management, identification of vulnerable areas, and allocation of resources. The study area is the Saginaw River watershed located in Michigan. In-stream hydrological and water quality data were used to predict fish and macroinvertebrate measures of stream health. These measures include the Index of Biological Integrity (IBI), Hilsenhoff Biotic Index (HBI), Family IBI, and total number of Ephemeroptera, Plecoptera, and Trichoptera (EPT) taxa. Stream health indicators were then compared to spatially coincident socio-economic data, obtained from the United States Census Bureau (2010), including race, income, education, housing, and population size. Statistical analysis including spatial regression and cluster analysis were used to examine the correlation between vulnerable human populations and environmental conditions. Overall, limited correlation was observed between the socio-economic data and ecological measures of stream health, with the highest being a negative correlation of 0.18 between HBI and the social parameter household size. Clustering was observed in the datasets with urban areas representing a second order clustering effect over the watershed. Regions with the worst stream health and most vulnerable social populations were most commonly located nearby or down-stream to highly populated areas and agricultural lands.

Establishment and baseline characteristics of a nationwide Danish cohort of patients with Ehlers-Danlos syndrome.

PubMed

Kulas Søborg, Marie-Louise; Leganger, Julie; Quitzau Mortensen, Laura; Rosenberg, Jacob; Burcharth, Jakob

2017-05-01

The aim of this study was to investigate national prevalence, general demographic characteristics and survival of Danish patients with Ehlers-Danlos syndrome (EDS). A population-based cohort study was conducted using a database consisting of the entire Danish population alive at any given time between 1 January 2000 and 31 December 2012, based upon longitudinal Danish national registers. All patients with EDS were identified, and the cohort was described by disease prevalence, basic demographic characteristics, mean age at death and mortality for the observational period of 13 years. The cohort held 1427 unique persons with EDS, giving a national prevalence of 0.02%. The EDS population had a mean ( s . d .) age of 34.9 (18.6) years and comprised 73.9% females and 26.1% males. Of the cohort, 95.9% originated from Denmark and 57% were unmarried. We found that 31.6% of the cohort received state-granted subsidies, of which 77% were in the form of early retirement pension. Regarding educational status, 28.1% of the EDS cohort had completed primary education (⩽10th grade) as their highest educational level, while 71.9% had completed a higher level. During the observation period, 42 patients died, with a mean ( s . d .) age at death of 53.6 (21.7) years. This study confirmed a small national prevalence of patients diagnosed with EDS and showed that the majority of patients diagnosed are female. The EDS cohort had a lower educational level, mean age and life expectancy compared with the background population and showed a predisposition for receiving state-granted subsidies. © The Author 2017. Published by Oxford University Press on behalf of the British Society for Rheumatology. All rights reserved. For Permissions, please email: journals.permissions@oup.com

Comorbidity profile of poliomyelitis survivors in a Chinese population: a population-based study.

PubMed

Kang, Jiunn-Horng; Lin, Herng-Ching

2011-06-01

Previous reports of comorbid conditions in poliomyelitis survivors mainly focused on some disease categories, such as respiratory diseases, gastrointestinal diseases, psychiatric diseases, neurological diseases and cancer. Data regarding a wide spectrum of medical comorbidities in patients with poliomyelitis is still sparse. This study aimed to investigate and profile the wide range of comorbidities among the survivors of paralytic poliomyelitis in a Chinese population. In total, 2,032 paralytic poliomyelitis patients were selected as the study group and the comparison group consisted of 10,160 randomly selected enrollees. The comorbidities for analysis were based on a modified version of the Elixhauser Comorbidity Index. Conditional logistic regression analyses were computed to investigate the risk of comorbidities for these two groups. As compared to controls, patients with paralytic poliomyelitis had significantly higher prevalence of hypertension, ischemic heart disease, hyperlipidemia, congestive heart failure, cardiac arrhythmias, peripheral vascular disorder, stroke, paralysis, migraines, Parkinson's disease, rheumatoid arthritis, ankylosing spondylitis, pulmonary circulation disorders, chronic pulmonary disease, liver disease, peptic ulcers, hepatitis B or C, deficiency anemias, depression, and lymphoma. Most of the differences are of clinical interest, ORs often being between 2 and 3. No significant difference between poliomyelitis patients and controls was observed in the prevalence of SLE, tuberculosis, alcohol abuse and drug abuse. Our findings demonstrate that survivors of paralytic poliomyelitis in Taiwan are at higher risk of having multiple medical comorbidities although some potential confounding factors including educational level, marital status, obesity and physical activity are not available in our database. The pattern is generally consistent with previous observations from Western populations. Nevertheless, we found several novel associations which have rarely, if ever, been reported previously.

Classification and conservation priority of five Deccani sheep ecotypes of Maharashtra, India

PubMed Central

Arora, Reena; Jain, Anand

2017-01-01

Characterization of Indian livestock breeds has mostly been limited to single breed/population focused on either physical description of traditionally recognized breeds/populations or to their genetic description. Usually, morphological and genetic characterization has taken place in isolation. A parallel morphological characterization of genetically identified breeds or genetic characterization of morphologically described breeds is mostly missing, and their conservation priorities have largely been based on solely considering degree of endangerment. This study uses parallel approach based on morphometric and genetic differentiation for classification of five sheep ecotypes of Maharashtra state, and sets their conservation priority using threat parameters, current utilities/merits and contribution to genetic diversity. A total of 1101 animals were described for 7 body measurements for morphometric characterization. From this sample set, 456 animals were genotyped for 25 microsatellite markers for genetic characterization. Conservation priorities were assessed combining genetic and non-genetic factors. All studied traits varied significantly among ecotypes (p<0.05). All morphometric traits exhibited substantial sexual dimorphism except ear length. Males were 42% heavier than females. Madgyal sheep were the largest amongst the five ecotypes. In the stepwise discriminant analysis, all measured traits were significant and were found to have potential discriminatory power. Tail length was the most discriminatory trait. The Mahalanobis distance of the morphological traits between Kolhapuri and Madgyal was maximum (12.07) while the least differentiation was observed between Madgyal and Solapuri (1.50). Discriminant analysis showed that 68.12% sheep were classified into their source population. The Sangamneri sheep showed least assignment error (22%) whilst Solapuri exhibited maximum error level (41%). A total of 407 alleles were observed, with an average of 16.28 alleles per locus. Sufficient levels of genetic diversity were observed in all the ecotypes with observed heterozygosity values exceeding 0.47 and gene diversity values exceeding 0.76. About 6% of the total genetic variation was explained by population differences (FST = 0.059). Pairwise FST values indicated least differentiation between Solapuri and Madgyal (0.025). In terms of genetic distances, Kolhapuri and Lonand were most closely related (Ds = 0.177). The most probable structure clustering of the five studied populations was at K = 5. The study showed a fair congruence between the dendrogram constructed on the basis of Mahalanobis distances and Nei’s as well as Reynolds genetic distances. The findings gave highest conservation priority to Lonand and least to Solapuri ecotype. PMID:28910329

TEACH: An Ethogram-Based Method to Observe and Record Teaching Behavior

ERIC Educational Resources Information Center

Kline, Michelle Ann

2017-01-01

Teaching has attracted growing research attention in studies of human and animal behavior as a crucial behavior that coevolved with human cultural capacities. However, the synthesis of data on teaching across species and across human populations has proven elusive because researchers use a variety of definitions and methods to approach the topic.…

Gender-Based Approaches to Language Teaching and Language Choice in the Academic Environment: An Analysis.

ERIC Educational Resources Information Center

Fidalgo, Reyes

The focus of this highly quantitative investigation is the analysis of the differences observed, both in methodological approach and in language choice in the classroom, during five years of classroom visitations. The study reflects information collected from two very different institutions with radically distinct populations: a rural setting with…

How Do Physicians Become Medical Experts? A Test of Three Competing Theories: Distinct Domains, Independent Influence and Encapsulation Models

ERIC Educational Resources Information Center

Violato, Claudio; Gao, Hong; O'Brien, Mary Claire; Grier, David; Shen, E.

2018-01-01

The distinction between basic sciences and clinical knowledge which has led to a theoretical debate on how medical expertise is developed has implications for medical school and lifelong medical education. This longitudinal, population based observational study was conducted to test the fit of three theories--knowledge encapsulation, independent…

Adaptive non-linear control for cancer therapy through a Fokker-Planck observer.

PubMed

Shakeri, Ehsan; Latif-Shabgahi, Gholamreza; Esmaeili Abharian, Amir

2018-04-01

In recent years, many efforts have been made to present optimal strategies for cancer therapy through the mathematical modelling of tumour-cell population dynamics and optimal control theory. In many cases, therapy effect is included in the drift term of the stochastic Gompertz model. By fitting the model with empirical data, the parameters of therapy function are estimated. The reported research works have not presented any algorithm to determine the optimal parameters of therapy function. In this study, a logarithmic therapy function is entered in the drift term of the Gompertz model. Using the proposed control algorithm, the therapy function parameters are predicted and adaptively adjusted. To control the growth of tumour-cell population, its moments must be manipulated. This study employs the probability density function (PDF) control approach because of its ability to control all the process moments. A Fokker-Planck-based non-linear stochastic observer will be used to determine the PDF of the process. A cost function based on the difference between a predefined desired PDF and PDF of tumour-cell population is defined. Using the proposed algorithm, the therapy function parameters are adjusted in such a manner that the cost function is minimised. The existence of an optimal therapy function is also proved. The numerical results are finally given to demonstrate the effectiveness of the proposed method.

A plant-based diet for overweight and obesity prevention and treatment

PubMed Central

Turner-McGrievy, Gabrielle; Mandes, Trisha; Crimarco, Anthony

2017-01-01

The goal of this paper is to review the evidence related to the effect of plant-based dietary patterns on obesity and weight loss, including both observational and intervention trials. Literature from plant-based diets (PBDs) epidemiological and clinical trial research was used to inform this review. In addition, data on dietary quality, adherence, and acceptability were evaluated and are presented. Both clinical trials and observational research indicate an advantage to adoption of PBDs for preventing overweight and obesity and promoting weight loss. PBDs may also confer higher levels of diet quality than are observed with other therapeutic diet approaches, with similar levels of adherence and acceptability. Future studies should utilize health behavior theory to inform intervention development and delivery of PBDs studies and new technologies to bring interventions to scale for greater public health impact. Research examining PBDs and weight loss is also needed with more diverse populations, including older adults. Based on the available evidence, PBDs should be considered a viable option for the treatment and prevention of overweight and obesity. PMID:28630616

A plant-based diet for overweight and obesity prevention and treatment.

PubMed

Turner-McGrievy, Gabrielle; Mandes, Trisha; Crimarco, Anthony

2017-05-01

The goal of this paper is to review the evidence related to the effect of plant-based dietary patterns on obesity and weight loss, including both observational and intervention trials. Literature from plant-based diets (PBDs) epidemiological and clinical trial research was used to inform this review. In addition, data on dietary quality, adherence, and acceptability were evaluated and are presented. Both clinical trials and observational research indicate an advantage to adoption of PBDs for preventing overweight and obesity and promoting weight loss. PBDs may also confer higher levels of diet quality than are observed with other therapeutic diet approaches, with similar levels of adherence and acceptability. Future studies should utilize health behavior theory to inform intervention development and delivery of PBDs studies and new technologies to bring interventions to scale for greater public health impact. Research examining PBDs and weight loss is also needed with more diverse populations, including older adults. Based on the available evidence, PBDs should be considered a viable option for the treatment and prevention of overweight and obesity.

Risk of colorectal cancer and small bowel adenocarcinoma in Crohn's disease: a population-based study from western Hungary 1977-2008.

PubMed

Lakatos, Peter Laszlo; David, Gyula; Pandur, Tunde; Erdelyi, Zsuzsanna; Mester, Gabor; Balogh, Mihaly; Szipocs, Istvan; Molnar, Csaba; Komaromi, Erzsebet; Kiss, Lajos S; Lakatos, Laszlo

2011-04-01

Limited data are available on the incidence and predictors of colorectal (CRC) and small bowel adenocarcinoma (SBA) in patients with Crohn's disease (CD) from population-based cohorts. Since data are completely missing from Eastern Europe, our aim was to analyze the incidence and risk factors of CD associated CRC and SBA in the population-based, Veszprem province database, which included incident patients diagnosed between January 1, 1977 and December 31, 2008. The data of 506 incident CD patients were analyzed (age-at-diagnosis: 31.5, SD: 13.8 years). Both hospital and outpatient records were collected and comprehensively reviewed. CRC was diagnosed in five patients (5/5758 person-year-duration) during follow-up, while no patients developed SBA in this cohort. Standardized incidence ratio (SIR) of CRC was not increased overall with five cases observed vs. 5.02 expected (SIR: 0.99, 95% CI: 0.41-2.39); however, there was a tendency for increased incidence in males (five cases observed vs. 2.56 expected; SIR: 1.95, 95% CI: 0.81-4.70). Age at onset of CD (p<0.001), male gender (p=0.022) and stenosing disease behavior at diagnosis (p<0.001) but not disease location were identified as risk factors for developing CRC in univariate analysis and Kaplan-Meier analysis. The cumulative risk for developing CRC after a disease duration of 20 years was 1.1% (95% CI: 0.6-1.7%). The incidence of CRC and SBA was not increased in this population-based CD cohort. Age at onset of CD, male gender and stenosing disease behavior at diagnosis were identified as risk factors of CRC. Copyright © 2010 European Crohn's and Colitis Organisation. Published by Elsevier B.V. All rights reserved.

Genetic diversity of the Tibetan antelope (Pantholops hodgsonii) population of Ladakh, India, its relationship with other populations and conservation implications.

PubMed

Ahmad, Khursheed; Kumar, Ved P; Joshi, Bheem Dutt; Raza, Mohamed; Nigam, Parag; Khan, Anzara Anjum; Goyal, Surendra P

2016-10-21

The Tibetan antelope (Pantholops hodgsonii), or chiru, is an endangered antelope, distributed in China [Xinjiang, Xizang, Qinghai, Zhuolaihu Lake (Breeding habitat)], and India (Aksai Chin and Ladakh). There is a global demand for the species prized wool, which is used in weaving shahtoosh shawls. Over the years, the population of the Tibetan antelope has drastically declined from more than a million to a few thousand individuals, mainly due to poaching. Field studies undertaken in Ladakh, India also indicated winter migration of the population to Tibet. Migration between winter and calving habitats is well established to be female-biased across the Qinghai Tibetan Plateau (QTP). For effective conservation planning, genetic characterization is considered the best way to understand the likely impact of threats for ensuring the long-term viability of the population. In this regard, genetic characteristics of all Chinese populations are well-studied using mitochondrial and microsatellite markers, but information is lacking for the Indian population. Therefore, using the control region marker, we document for the first time the genetic variation of the Indian population of the Tibetan antelope, the extent of migration and its relationships with other populations of China. The partial fragment of control region (259 bp) marker was successfully amplified in 30 Tibetan antelope samples that were collected from the Chang Chenmo Valley in eastern Ladakh, India. We also retrieved control region sequences (n = 88) available in the public domain from GenBank of different Chinese populations. Low levels of nucleotide (π; 0.004) and haplotype (hd; 0.543) diversity were observed in the Indian population when compared to Chinese populations (π = 0.01357-0.02048 and hd = 0.889-0.986). Commonly used indices (Tajima's D and Fu's Fs) were analyzed for inferring the demographic history of the Indian populations, and all values were negative indicating population expansion or demographic equilibrium, though nonsignificant. We observed five haplotypes in the Indian population, and these were not reported in previously studied populations of QTP. Bayesian-based phylogenetic analysis indicates the presence of four clades, however, the posterior probability support for three of these clades is weak (<0.5). Of these, the Indian population formed a distinct clade, whereas the Chinese populations exhibited shared haplotypes, and no geographic structure was observed. Median-joining network analysis was conducted for 46 haplotypes in the overall population, except the samples from India which showed a star-like topology. The Indian population is separated by one median vector from the Chinese population. The present study revealed the presence of different sub-clades in the Bayesian phylogenetic tree and five new haplotypes only in the Indian population or sampling location. Furthermore, in the phylogenetic tree, Indian haplotypes of Tibetan antelopes were clustered with the haplotype reported in the Chinese population of the Xinjiang region. Median-joining network analysis showed shared haplotypes pattern in all populations of QTP except the samples from India which showed new haplotypes. Given the presence of low nucleotide and haplotype diversity in eastern Ladakh populations and limited information available for populations of the western side in its range, we suggest to include genetic studies of Tibetan antelope populations around Aksai Chin (Fig. 1) under the proposed transboundary agenda between India and China and assess relationships with other populations. Such understanding would enable the planning of conservation strategies for ensuring long-term survival of westernmost populations in its range, and if required, it would establish connectivity with the other populations.

Statin Safety in Chinese: A Population-Based Study of Older Adults.

PubMed

Li, Daniel Q; Kim, Richard B; McArthur, Eric; Fleet, Jamie L; Hegele, Robert A; Shah, Baiju R; Weir, Matthew A; Molnar, Amber O; Dixon, Stephanie; Tu, Jack V; Anand, Sonia; Garg, Amit X

2016-01-01

Compared to Caucasians, Chinese achieve a higher blood concentration of statin for a given dose. It remains unknown whether this translates to increased risk of serious statin-associated adverse events amongst Chinese patients. We conducted a population-based retrospective cohort study of older adults (mean age, 74 years) newly prescribed a statin in Ontario, Canada between 2002 and 2013, where 19,033 Chinese (assessed through a validated surname algorithm) were matched (1:3) by propensity score to 57,099 non-Chinese. This study used linked healthcare databases. The follow-up observation period (mean 1.1, maximum 10.8 years) was similar between groups, as were the reasons for censoring the observation period (end of follow-up, death, or statin discontinuation). Forty-seven percent (47%) of Chinese were initiated on a higher than recommended statin dose. Compared to non-Chinese, Chinese ethnicity did not associate with any of the four serious statin-associated adverse events assessed in this study [rhabdomyolysis hazard ratio (HR) 0.61 (95% CI 0.28 to 1.34), incident diabetes HR 1.02 (95% CI 0.80 to 1.30), acute kidney injury HR 0.90 (95% CI 0.72 to 1.13), or all-cause mortality HR 0.88 (95% CI 0.74 to 1.05)]. Similar results were observed in subgroups defined by statin type and dose. We observed no higher risk of serious statin toxicity in Chinese than matched non-Chinese older adults with similar indicators of baseline health. Regulatory agencies should review available data, including findings from our study, to decide if a change in their statin dosing recommendations for people of Chinese ethnicity is warranted.

Standardizing the double-observer survey method for estimating mountain ungulate prey of the endangered snow leopard.

PubMed

Suryawanshi, Kulbhushansingh R; Bhatnagar, Yash Veer; Mishra, Charudutt

2012-07-01

Mountain ungulates around the world have been threatened by illegal hunting, habitat modification, increased livestock grazing, disease and development. Mountain ungulates play an important functional role in grasslands as primary consumers and as prey for wild carnivores, and monitoring of their populations is important for conservation purposes. However, most of the several currently available methods of estimating wild ungulate abundance are either difficult to implement or too expensive for mountainous terrain. A rigorous method of sampling ungulate abundance in mountainous areas that can allow for some measure of sampling error is therefore much needed. To this end, we used a combination of field data and computer simulations to test the critical assumptions associated with double-observer technique based on capture-recapture theory. The technique was modified and adapted to estimate the populations of bharal (Pseudois nayaur) and ibex (Capra sibirica) at five different sites. Conducting the two double-observer surveys simultaneously led to underestimation of the population by 15%. We therefore recommend separating the surveys in space or time. The overall detection probability for the two observers was 0.74 and 0.79. Our surveys estimated mountain ungulate populations (± 95% confidence interval) of 735 (± 44), 580 (± 46), 509 (± 53), 184 (± 40) and 30 (± 14) individuals at the five sites, respectively. A detection probability of 0.75 was found to be sufficient to detect a change of 20% in populations of >420 individuals. Based on these results, we believe that this method is sufficiently precise for scientific and conservation purposes and therefore recommend the use of the double-observer approach (with the two surveys separated in time or space) for the estimation and monitoring of mountain ungulate populations.

Geographic strain differentiation of Schistosoma japonicum in the Philippines using microsatellite markers

PubMed Central

Moendeg, Kharleezelle J.; Angeles, Jose Ma M.; Nakao, Ryo; Leonardo, Lydia R.; Fontanilla, Ian Kendrich C.; Goto, Yasuyuki; Kirinoki, Masashi; Villacorte, Elena A.; Rivera, Pilarita T.; Inoue, Noboru; Chigusa, Yuichi

2017-01-01

Background Microsatellites have been found to be useful in determining genetic diversities of various medically-important parasites which can be used as basis for an effective disease management and control program. In Asia and Africa, the identification of different geographical strains of Schistosoma japonicum, S. haematobium and S. mansoni as determined through microsatellites could pave the way for a better understanding of the transmission epidemiology of the parasite. Thus, the present study aims to apply microsatellite markers in analyzing the populations of S. japonicum from different endemic areas in the Philippines for possible strain differentiation. Methodology/ Principal findings Experimental mice were infected using the cercariae of S. japonicum collected from infected Oncomelania hupensis quadrasi snails in seven endemic municipalities. Adult worms were harvested from infected mice after 45 days of infection and their DNA analyzed against ten previously characterized microsatellite loci. High genetic diversity was observed in areas with high endemicity. The degree of genetic differentiation of the parasite population between endemic areas varies. Geographical separation was considered as one of the factors accounting for the observed difference between populations. Two subgroups have been observed in one of the study sites, suggesting that co-infection with several genotypes of the parasite might be present in the population. Clustering analysis showed no particular spatial structuring between parasite populations from different endemic areas. This result could possibly suggest varying degrees of effects of the ongoing control programs and the existing gene flow in the populations, which might be attributed to migration and active movement of infected hosts from one endemic area to another. Conclusions/ Significance Based on the results of the study, it is reasonable to conclude that genetic diversity could be one possible criterion to assess the infection status in highly endemic areas. Genetic surveillance using microsatellites is therefore important to predict the ongoing gene flow and degree of genetic diversity, which indirectly reflects the success of the control program in schistosomiasis-endemic areas. PMID:28692692

Prevalence of Dementia and Cognitive Complaints in the Context of High Cognitive Reserve: A Population-Based Study.

PubMed

Perquin, Magali; Diederich, Nico; Pastore, Jessica; Lair, Marie-Lise; Stranges, Saverio; Vaillant, Michel

2015-01-01

This study aimed to assess the prevalence of dementia and cognitive complaints in a cross-sectional sample of Luxembourg seniors, and to discuss the results in the societal context of high cognitive reserve resulting from multilingualism. A population sample of 1,377 people representative of Luxembourg residents aged over 64 years was initially identified via the national social insurance register. There were three different levels of contribution: full participation in the study, partial participation, and non-participation. We examined the profiles of these three different samples so that we could infer the prevalence estimates in the Luxembourgish senior population as a whole using the prevalence estimates obtained in this study. After careful attention to the potential bias and of the possibility of underestimation, we considered the obtained prevalence estimates of 3.8% for dementia (with corresponding 95% confidence limits (CL) of 2.8% and 4.8%) and 26.1% for cognitive complaints (CL = [17.8-34.3]) as trustworthy. Based on these findings, we postulate that high cognitive reserve may result in surprisingly low prevalence estimates of cognitive complaints and dementia in adults over the age of 64 years, which thereby corroborates the longer disability-free life expectancy observed in the Luxembourg population. To the best of our knowledge, this study is the first to report such Luxembourgish public health data.

Prevalence of Dementia and Cognitive Complaints in the Context of High Cognitive Reserve: A Population-Based Study

PubMed Central

Perquin, Magali; Diederich, Nico; Pastore, Jessica; Lair, Marie-Lise; Stranges, Saverio; Vaillant, Michel

2015-01-01

Objectives This study aimed to assess the prevalence of dementia and cognitive complaints in a cross-sectional sample of Luxembourg seniors, and to discuss the results in the societal context of high cognitive reserve resulting from multilingualism. Methods A population sample of 1,377 people representative of Luxembourg residents aged over 64 years was initially identified via the national social insurance register. There were three different levels of contribution: full participation in the study, partial participation, and non-participation. We examined the profiles of these three different samples so that we could infer the prevalence estimates in the Luxembourgish senior population as a whole using the prevalence estimates obtained in this study. Results After careful attention to the potential bias and of the possibility of underestimation, we considered the obtained prevalence estimates of 3.8% for dementia (with corresponding 95% confidence limits (CL) of 2.8% and 4.8%) and 26.1% for cognitive complaints (CL = [17.8–34.3]) as trustworthy. Conclusion Based on these findings, we postulate that high cognitive reserve may result in surprisingly low prevalence estimates of cognitive complaints and dementia in adults over the age of 64 years, which thereby corroborates the longer disability-free life expectancy observed in the Luxembourg population. To the best of our knowledge, this study is the first to report such Luxembourgish public health data. PMID:26390288

Modeling larval connectivity of the Atlantic surfclams within the Middle Atlantic Bight: Model development, larval dispersal and metapopulation connectivity

NASA Astrophysics Data System (ADS)

Zhang, Xinzhong; Haidvogel, Dale; Munroe, Daphne; Powell, Eric N.; Klinck, John; Mann, Roger; Castruccio, Frederic S.

2015-02-01

To study the primary larval transport pathways and inter-population connectivity patterns of the Atlantic surfclam, Spisula solidissima, a coupled modeling system combining a physical circulation model of the Middle Atlantic Bight (MAB), Georges Bank (GBK) and the Gulf of Maine (GoM), and an individual-based surfclam larval model was implemented, validated and applied. Model validation shows that the model can reproduce the observed physical circulation patterns and surface and bottom water temperature, and recreates the observed distributions of surfclam larvae during upwelling and downwelling events. The model results show a typical along-shore connectivity pattern from the northeast to the southwest among the surfclam populations distributed from Georges Bank west and south along the MAB shelf. Continuous surfclam larval input into regions off Delmarva (DMV) and New Jersey (NJ) suggests that insufficient larval supply is unlikely to be the factor causing the failure of the population to recover after the observed decline of the surfclam populations in DMV and NJ from 1997 to 2005. The GBK surfclam population is relatively more isolated than populations to the west and south in the MAB; model results suggest substantial inter-population connectivity from southern New England to the Delmarva region. Simulated surfclam larvae generally drift for over one hundred kilometers along the shelf, but the distance traveled is highly variable in space and over time. Surfclam larval growth and transport are strongly impacted by the physical environment. This suggests the need to further examine how the interaction between environment, behavior, and physiology affects inter-population connectivity. Larval vertical swimming and sinking behaviors have a significant net effect of increasing larval drifting distances when compared with a purely passive model, confirming the need to include larval behavior.

Fine mapping of genetic polymorphisms of pulmonary tuberculosis within chromosome 18q11.2 in the Chinese population: a case-control study.

PubMed

Dai, Yaoyao; Zhang, Xia; Pan, Hongqiu; Tang, Shaowen; Shen, Hongbing; Wang, Jianming

2011-10-22

Recently, one genome-wide association study identified a susceptibility locus of rs4331426 on chromosome 18q11.2 for tuberculosis in the African population. To validate the significance of this susceptibility locus in other areas, we conducted a case-control study in the Chinese population. The present study consisted of 578 cases and 756 controls. The SNP rs4331426 and other six tag SNPs in the 100 Kbp up and down stream of rs4331426 on chromosome 18q11.2 were genotyped by using the Taqman-based allelic discrimination system. As compared with the findings from the African population, genetic variation of the SNP rs4331426 was rare among the Chinese. No significant differences were observed in genotypes or allele frequencies of the tag SNPs between cases and controls either before or after adjusting for age, sex, education, smoking, and drinking history. However, we observed strong linkage disequilibrium of SNPs. Constructed haplotypes within this block were linked the altered risks of tuberculosis. For example, in comparison with the common haplotype AA(rs8087945-rs12456774), haplotypes AG(rs8087945-rs12456774) and GA(rs8087945-rs12456774) were associated with a decreased risk of tuberculosis, with the adjusted odds ratio(95% confidence interval) of 0.34(0.27-0.42) and 0.22(0.16-0.29), respectively. Susceptibility locus of rs4331426 discovered in the African population could not be validated in the Chinese population. None of genetic polymorphisms we genotyped were related to tuberculosis in the single-point analysis. However, haplotypes on chromosome 18q11.2 might contribute to an individual's susceptibility. More work is necessary to identify the true causative variants of tuberculosis.

Relevance of genetic relationship in GWAS and genomic prediction.

PubMed

Pereira, Helcio Duarte; Soriano Viana, José Marcelo; Andrade, Andréa Carla Bastos; Fonseca E Silva, Fabyano; Paes, Geísa Pinheiro

2018-02-01

The objective of this study was to analyze the relevance of relationship information on the identification of low heritability quantitative trait loci (QTLs) from a genome-wide association study (GWAS) and on the genomic prediction of complex traits in human, animal and cross-pollinating populations. The simulation-based data sets included 50 samples of 1000 individuals of seven populations derived from a common population with linkage disequilibrium. The populations had non-inbred and inbred progeny structure (50 to 200) with varying number of members (5 to 20). The individuals were genotyped for 10,000 single nucleotide polymorphisms (SNPs) and phenotyped for a quantitative trait controlled by 10 QTLs and 90 minor genes showing dominance. The SNP density was 0.1 cM and the narrow sense heritability was 25%. The QTL heritabilities ranged from 1.1 to 2.9%. We applied mixed model approaches for both GWAS and genomic prediction using pedigree-based and genomic relationship matrices. For GWAS, the observed false discovery rate was kept below the significance level of 5%, the power of detection for the low heritability QTLs ranged from 14 to 50%, and the average bias between significant SNPs and a QTL ranged from less than 0.01 to 0.23 cM. The QTL detection power was consistently higher using genomic relationship matrix. Regardless of population and training set size, genomic prediction provided higher prediction accuracy of complex trait when compared to pedigree-based prediction. The accuracy of genomic prediction when there is relatedness between individuals in the training set and the reference population is much higher than the value for unrelated individuals.

Population pharmacokinetics of empagliflozin, a sodium glucose cotransporter 2 inhibitor, in patients with type 2 diabetes.

PubMed

Riggs, Matthew M; Staab, Alexander; Seman, Leo; MacGregor, Thomas R; Bergsma, Timothy T; Gastonguay, Marc R; Macha, Sreeraj

2013-10-01

Data from five randomized, placebo-controlled, multiple oral dose studies of empagliflozin in patients with type 2 diabetes mellitus (T2DM; N = 974; 1-100 mg q.d.; ≤12 weeks) were used to develop a population pharmacokinetic (PK) model for empagliflozin. The model consisted of two-compartmental disposition, lagged first-order absorption and first-order elimination, and incorporated appropriate covariates. Population estimates (interindividual variance, CV%) of oral apparent clearance, central and peripheral volumes of distribution, and inter-compartmental clearance were 9.87 L/h (26.9%), 3.02 L, 60.4 L (30.8%), and 5.16 L/h, respectively. An imposed allometric weight effect was the most influential PK covariate effect, with a maximum effect on exposure of ±30%, using 2.5th and 97.5th percentiles of observed weights, relative to the median observed weight. Sex and race did not lend additional description to PK variability beyond allometric weight effects, other than ∼25% greater oral absorption rate constant for Asian patients. Age, total protein, and smoking/alcohol history did not affect PK parameters. Predictive check plots were consistent with observed data, implying an adequate description of empagliflozin PKs following multiple dosing in patients with T2DM. The lack of marked covariate effects, including weight, suggests that no exposure-based dose adjustments were required within the study population and dose range. © The Author(s) 2013 John Wiley & Sons, Ltd.

Generative inference for cultural evolution.

PubMed

Kandler, Anne; Powell, Adam

2018-04-05

One of the major challenges in cultural evolution is to understand why and how various forms of social learning are used in human populations, both now and in the past. To date, much of the theoretical work on social learning has been done in isolation of data, and consequently many insights focus on revealing the learning processes or the distributions of cultural variants that are expected to have evolved in human populations. In population genetics, recent methodological advances have allowed a greater understanding of the explicit demographic and/or selection mechanisms that underlie observed allele frequency distributions across the globe, and their change through time. In particular, generative frameworks-often using coalescent-based simulation coupled with approximate Bayesian computation (ABC)-have provided robust inferences on the human past, with no reliance on a priori assumptions of equilibrium. Here, we demonstrate the applicability and utility of generative inference approaches to the field of cultural evolution. The framework advocated here uses observed population-level frequency data directly to establish the likely presence or absence of particular hypothesized learning strategies. In this context, we discuss the problem of equifinality and argue that, in the light of sparse cultural data and the multiplicity of possible social learning processes, the exclusion of those processes inconsistent with the observed data might be the most instructive outcome. Finally, we summarize the findings of generative inference approaches applied to a number of case studies.This article is part of the theme issue 'Bridging cultural gaps: interdisciplinary studies in human cultural evolution'. © 2018 The Author(s).

Population pharmacokinetics of intravenous Erwinia asparaginase in pediatric acute lymphoblastic leukemia patients.

PubMed

Sassen, Sebastiaan D T; Mathôt, Ron A A; Pieters, Rob; Kloos, Robin Q H; de Haas, Valérie; Kaspers, Gertjan J L; van den Bos, Cor; Tissing, Wim J E; Te Loo, Maroeska; Bierings, Marc B; Kollen, Wouter J W; Zwaan, Christian M; van der Sluis, Inge M

2017-03-01

Erwinia asparaginase is an important component in the treatment of pediatric acute lymphoblastic leukemia. A large variability in serum concentrations has been observed after intravenous Erwinia asparaginase. Currently, Dutch Childhood Oncology Group protocols dose alterations are based on trough concentrations to ensure adequate asparaginase activity (≥100 IU/L). The aim of this study was to describe the population pharmacokinetics of intravenous Erwinia asparaginase to quantify and gather insight into inter-individual and inter-occasion variability. The starting dose was evaluated on the basis of the derived population pharmacokinetic parameters. In a multicenter prospective observational study, a total of 714 blood samples were collected from 51 children (age 1-17 years) with acute lymphoblastic leukemia. The starting dose was 20,000 IU/m 2 three times a week and adjusted according to trough levels from week three onwards. A population pharmacokinetic model was developed using NONMEM ® A 2-compartment linear model with allometric scaling best described the data. Inter-individual and inter-occasion variability of clearance were 33% and 13%, respectively. Clearance in the first month of treatment was 14% higher ( P <0.01). Monte Carlo simulations with our pharmacokinetic model demonstrated that patients with a low weight might require higher doses to achieve similar concentrations compared to patients with high weight. The current starting dose of 20,000 IU/m 2 might result in inadequate concentrations, especially for smaller, lower weight patients, hence dose adjustments based on individual clearance are recommended. The protocols were approved by the institutional review boards. (Registered at NTR 3379 Dutch Trial Register; www.trialregister.nl). Copyright© Ferrata Storti Foundation.

Level of emotional awareness in the general French population: effects of gender, age, and education level.

PubMed

Nandrino, Jean-Louis; Baracca, Margaret; Antoine, Pascal; Paget, Virginie; Bydlowski, Sarah; Carton, Solange

2013-01-01

The Levels of Emotional Awareness Scale (LEAS) developed by Lane et al. (1990) measures the ability of a subject to discriminate his or her own emotional state and that of others. The scale is based on a cognitive-developmental model in which emotional awareness increases in a similar fashion to intellectual functions. Because studies performed using North American and German populations have demonstrated an effect of age, gender, and level of education on the ability to differentiate emotional states, our study attempts to evaluate whether these factors have the same effects in a general French population. 750 volunteers (506 female, 244 male), who were recruited from three regions of France (Lille, Montpellier, Paris), completed the LEAS. The sample was divided into five age groups and three education levels. The results of the LEAS scores for self and others and the total score showed a difference in the level of emotional awareness for different age groups, by gender and education level. A higher emotional level was observed for younger age groups, suggesting that emotional awareness depends on the cultural context and generational societal teachings. Additionally, the level of emotional awareness was higher in women than in men and lower in individuals with less education. This result might be explained by an educational bias linked to gender and higher education whereby expressive ability is reinforced. In addition, given the high degree of variability in previously observed scores in the French population, we propose a standard based on our French sample.

Using probability modelling and genetic parentage assignment to test the role of local mate availability in mating system variation.

PubMed

Blyton, Michaela D J; Banks, Sam C; Peakall, Rod; Lindenmayer, David B

2012-02-01

The formal testing of mating system theories with empirical data is important for evaluating the relative importance of different processes in shaping mating systems in wild populations. Here, we present a generally applicable probability modelling framework to test the role of local mate availability in determining a population's level of genetic monogamy. We provide a significance test for detecting departures in observed mating patterns from model expectations based on mate availability alone, allowing the presence and direction of behavioural effects to be inferred. The assessment of mate availability can be flexible and in this study it was based on population density, sex ratio and spatial arrangement. This approach provides a useful tool for (1) isolating the effect of mate availability in variable mating systems and (2) in combination with genetic parentage analyses, gaining insights into the nature of mating behaviours in elusive species. To illustrate this modelling approach, we have applied it to investigate the variable mating system of the mountain brushtail possum (Trichosurus cunninghami) and compared the model expectations with the outcomes of genetic parentage analysis over an 18-year study. The observed level of monogamy was higher than predicted under the model. Thus, behavioural traits, such as mate guarding or selective mate choice, may increase the population level of monogamy. We show that combining genetic parentage data with probability modelling can facilitate an improved understanding of the complex interactions between behavioural adaptations and demographic dynamics in driving mating system variation. © 2011 Blackwell Publishing Ltd.

Resolving the Milky Way and Nearby Galaxies with WFIRST

NASA Astrophysics Data System (ADS)

Kalirai, Jasonjot

High-resolution studies of nearby stellar populations have served as a foundation for our quest to understand the nature of galaxies. Today, studies of resolved stellar populations constrain fundamental relations -- such as the initial mass function of stars, the time scales of stellar evolution, the timing of mass loss and amount of energetic feedback, the color-magnitude relation and its dependency on age and metallicity, the stellar-dark matter connection in galaxy halos, and the build up of stellar populations over cosmic time -- that represent key ingredients in our prescription to interpret light from the Universe and to measure the physical state of galaxies. More than in any other area of astrophysics, WFIRST will yield a transformative impact in measuring and characterizing resolved stellar populations in the Milky Way and nearby galaxies. The proximity and level of detail that such populations need to be studied at directly map to all three pillars of WFIRST capabilities - sensitivity from a 2.4 meter space based telescope, resolution from 0.1" pixels, and large 0.3 degree field of view from multiple detectors. Our WFIRST GO Science Investigation Team (F) will develop three WFIRST (notional) GO programs related to resolved stellar populations to fully stress WFIRST's Wide Field Instrument. The programs will include a Survey of the Milky Way, a Survey of Nearby Galaxy Halos, and a Survey of Star-Forming Galaxies. Specific science goals for each program will be validated through a wide range of observational data sets, simulations, and new algorithms. As an output of this study, our team will deliver optimized strategies and tools to maximize stellar population science with WFIRST. This will include: new grids of IR-optimized stellar evolution and synthetic spectroscopic models; pipelines and algorithms for optimal data reduction at the WFIRST sensitivity and pixel scale; wide field simulations of MW environments and galaxy halos; cosmological simulations of nearby galaxy halos matched to WFIRST observations; strategies and automated algorithms to find substructure and dwarf galaxies in WFIRST IR data sets; and documentation. Our team will work closely with the WFIRST Science Center to translate our notional programs into inputs that can help achieve readiness for WFIRST science operations. This includes building full observing programs with target definitions, observing sequences, scheduling constraints, data processing needs, and calibration requirements. Our team has been chosen carefully. Team members are leading scientists in stellar population work that will be a core science theme for WFIRST and are also involved in all large future astronomy projects that will operate in the WFIRST era. The team is intentionally small, and each member will "own" significant science projects. The team will aggressively advocate for WFIRST through innovative initiatives. The team is also diverse in geographical location, observers and theorists, and gender.

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass.

PubMed

Pembleton, Luke W; Inch, Courtney; Baillie, Rebecca C; Drayton, Michelle C; Thakur, Preeti; Ogaji, Yvonne O; Spangenberg, German C; Forster, John W; Daetwyler, Hans D; Cogan, Noel O I

2018-06-02

Exploitation of data from a ryegrass breeding program has enabled rapid development and implementation of genomic selection for sward-based biomass yield with a twofold-to-threefold increase in genetic gain. Genomic selection, which uses genome-wide sequence polymorphism data and quantitative genetics techniques to predict plant performance, has large potential for the improvement in pasture plants. Major factors influencing the accuracy of genomic selection include the size of reference populations, trait heritability values and the genetic diversity of breeding populations. Global diversity of the important forage species perennial ryegrass is high and so would require a large reference population in order to achieve moderate accuracies of genomic selection. However, diversity of germplasm within a breeding program is likely to be lower. In addition, de novo construction and characterisation of reference populations are a logistically complex process. Consequently, historical phenotypic records for seasonal biomass yield and heading date over a 18-year period within a commercial perennial ryegrass breeding program have been accessed, and target populations have been characterised with a high-density transcriptome-based genotyping-by-sequencing assay. Ability to predict observed phenotypic performance in each successive year was assessed by using all synthetic populations from previous years as a reference population. Moderate and high accuracies were achieved for the two traits, respectively, consistent with broad-sense heritability values. The present study represents the first demonstration and validation of genomic selection for seasonal biomass yield within a diverse commercial breeding program across multiple years. These results, supported by previous simulation studies, demonstrate the ability to predict sward-based phenotypic performance early in the process of individual plant selection, so shortening the breeding cycle, increasing the rate of genetic gain and allowing rapid adoption in ryegrass improvement programs.

Occupational exposure to chemicals drives the increased risk of asthma and rhinitis observed for exposure to vapours, gas, dust and fumes: a cross-sectional population-based study.

PubMed

Schyllert, Christian; Rönmark, Eva; Andersson, Martin; Hedlund, Ulf; Lundbäck, Bo; Hedman, Linnea; Lindberg, Anne

2016-10-01

Occupational exposure to the composite measure vapours, gases, dusts and fumes (VGDF), contribute to the burden of asthma and rhinitis. The objective was to evaluate occupational exposure to VGDF, which is further divided into the components chemicals, organic and inorganic dust in relation to asthma and rhinitis. Previously examined participants from three population-based cohorts in the Obstructive Lung disease In Northern Sweden (OLIN) studies were re-examined during 2002-2004. In total, 4036 participated in a structured interview and answered a questionnaire on occupational exposures. Occupational exposure to VGDF increased the risk of asthma, and concomitant asthma and rhinitis. Exposure to chemicals, but not dust, showed a similar pattern. Exposure to chemicals increased the risks (OR, 95% CI) of rhinitis without asthma (1.29, 1.10 to 1.52), asthma without rhinitis (1.42, 1.15 to 1.77) and concomitant asthma and rhinitis (1.60, 1.31 to 1.96) when adjusted for confounders such as age, smoking habits, body mass index and sex. The association between exposure to chemicals and asthma and rhinitis remained independent of exposure to dust and was also so when excluding exposure to isocyanates and welding fumes. The results were similar for women and men, as well as for never-smokers and participants without a history of allergy. In this cross-sectional population-based study, occupational exposure to chemicals contributed substantially to the increased risk of asthma and rhinitis observed for occupational exposure to VGDF. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Sex Hormones and Sleep in Men and Women From the General Population: A Cross-Sectional Observational Study.

PubMed

Kische, Hanna; Ewert, Ralf; Fietze, Ingo; Gross, Stefan; Wallaschofski, Henri; Völzke, Henry; Dörr, Marcus; Nauck, Matthias; Obst, Anne; Stubbe, Beate; Penzel, Thomas; Haring, Robin

2016-11-01

Associations between sex hormones and sleep habits originate mainly from small and selected patient-based samples. We examined data from a population-based sample with various sleep characteristics and the major part of sex hormones measured by mass spectrometry. We used data from 204 men and 213 women of the cross-sectional Study of Health in Pomerania-TREND. Associations of total T (TT) and free T, androstenedione (ASD), estrone, estradiol (E2), dehydroepiandrosterone-sulphate, SHBG, and E2 to TT ratio with sleep measures (including total sleep time, sleep efficiency, wake after sleep onset, apnea-hypopnea index [AHI], Insomnia Severity Index, Epworth Sleepiness Scale, and Pittsburgh Sleep Quality Index) were assessed by sex-specific multivariable regression models. In men, age-adjusted associations of TT (odds ratio 0.62; 95% confidence interval (CI) 0.46-0.83), free T, and SHBG with AHI were rendered nonsignificant after multivariable adjustment. In multivariable analyses, ASD was associated with Epworth Sleepiness Scale (β-coefficient per SD increase in ASD: -0.71; 95% CI: -1.18 to -0.25). In women, multivariable analyses showed positive associations of dehydroepiandrosterone-sulphate with wake after sleep onset (β-coefficient: .16; 95% CI 0.03-0.28) and of E2 and E2 to TT ratio with Epworth Sleepiness Scale. Additionally, free T and SHBG were associated with AHI in multivariable models among premenopausal women. The present cross-sectional, population-based study observed sex-specific associations of androgens, E2, and SHBG with sleep apnea and daytime sleepiness. However, multivariable-adjusted analyses confirmed the impact of body composition and health-related lifestyle on the association between sex hormones and sleep.

The Molecular and Spatial Epidemiology of Typhoid Fever in Rural Cambodia.

PubMed

Pham Thanh, Duy; Thompson, Corinne N; Rabaa, Maia A; Sona, Soeng; Sopheary, Sun; Kumar, Varun; Moore, Catrin; Tran Vu Thieu, Nga; Wijedoru, Lalith; Holt, Kathryn E; Wong, Vanessa; Pickard, Derek; Thwaites, Guy E; Day, Nicholas; Dougan, Gordon; Turner, Paul; Parry, Christopher M; Baker, Stephen

2016-06-01

Typhoid fever, caused by the bacterium Salmonella Typhi, is an endemic cause of febrile disease in Cambodia. The aim of this study was to better understand the epidemiology of pediatric typhoid fever in Cambodia. We accessed routine blood culture data from Angkor Hospital for Children (AHC) in Siem Reap province between 2007 and 2014, and performed whole genome sequencing (WGS) on the isolated bacteria to characterize the S. Typhi population. The resulting phylogenetic information was combined with conventional epidemiological approaches to investigate the spatiotemporal distribution of S. Typhi and population-level risk factors for reported disease. During the study period, there were 262 cases of typhoid within a 100 km radius of AHC, with a median patient age of 8.2 years (IQR: 5.1-11.5 years). The majority of infections occurred during the rainy season, and commune incidences as high as 11.36/1,000 in children aged <15 years were observed over the study period. A population-based risk factor analysis found that access to water within households and increasing distance from Tonle Sap Lake were protective. Spatial mapping and WGS provided additional resolution for these findings, and confirmed that proximity to the lake was associated with discrete spatiotemporal disease clusters. We confirmed the dominance of MDR H58 S. Typhi in this population, and found substantial evidence of diversification (at least seven sublineages) within this single lineage. We conclude that there is a substantial burden of pediatric typhoid fever in rural communes in Cambodia. Our data provide a platform for additional population-based typhoid fever studies in this location, and suggest that this would be a suitable setting in which to introduce a school-based vaccination programme with Vi conjugate vaccines.

The Molecular and Spatial Epidemiology of Typhoid Fever in Rural Cambodia

PubMed Central

Rabaa, Maia A; Sona, Soeng; Sopheary, Sun; Kumar, Varun; Moore, Catrin; Tran Vu Thieu, Nga; Wijedoru, Lalith; Holt, Kathryn E.; Wong, Vanessa; Pickard, Derek; Thwaites, Guy E.; Day, Nicholas; Dougan, Gordon; Turner, Paul; Parry, Christopher M.; Baker, Stephen

2016-01-01

Typhoid fever, caused by the bacterium Salmonella Typhi, is an endemic cause of febrile disease in Cambodia. The aim of this study was to better understand the epidemiology of pediatric typhoid fever in Cambodia. We accessed routine blood culture data from Angkor Hospital for Children (AHC) in Siem Reap province between 2007 and 2014, and performed whole genome sequencing (WGS) on the isolated bacteria to characterize the S. Typhi population. The resulting phylogenetic information was combined with conventional epidemiological approaches to investigate the spatiotemporal distribution of S. Typhi and population-level risk factors for reported disease. During the study period, there were 262 cases of typhoid within a 100 km radius of AHC, with a median patient age of 8.2 years (IQR: 5.1–11.5 years). The majority of infections occurred during the rainy season, and commune incidences as high as 11.36/1,000 in children aged <15 years were observed over the study period. A population-based risk factor analysis found that access to water within households and increasing distance from Tonle Sap Lake were protective. Spatial mapping and WGS provided additional resolution for these findings, and confirmed that proximity to the lake was associated with discrete spatiotemporal disease clusters. We confirmed the dominance of MDR H58 S. Typhi in this population, and found substantial evidence of diversification (at least seven sublineages) within this single lineage. We conclude that there is a substantial burden of pediatric typhoid fever in rural communes in Cambodia. Our data provide a platform for additional population-based typhoid fever studies in this location, and suggest that this would be a suitable setting in which to introduce a school-based vaccination programme with Vi conjugate vaccines. PMID:27331909

Incidence of sport-related traumatic brain injury and risk factors of severity: a population-based epidemiologic study.

PubMed

Selassie, Anbesaw W; Wilson, Dulaney A; Pickelsimer, E Elisabeth; Voronca, Delia C; Williams, Nolan R; Edwards, Jonathan C

2013-12-01

Few studies of sport-related traumatic brain injury (TBI) are population-based or rely on directly observed data on cause, demographic characteristics, and severity. This study addresses the epidemiology of sport-related TBI in a large population. Data on all South Carolina hospital and emergency department encounters for TBI, 1998-2011, were analyzed. Annual incidence rate of sport-related TBI was calculated, and rates were compared across demographic groups. Sport-related TBI severity was modeled as a function of demographic and TBI characteristics using logistic regression. A total of 16,642 individuals with sport-related TBI yielded an average annual incidence rate of 31.5/100,000 population with a steady increase from 19.7 in 1998 to 45.6 in 2011. The most common mechanisms of sport-related TBI were kicked in football (38.1%), followed by fall injuries in sports (20.3%). Incidence rate was greatest in adolescents ages 12-18 (120.6/100,000/persons). Severe sport-related TBI was strongly associated with off-road vehicular sport (odds ratio [OR], 4.73; 95% confidence interval [95% CI], 2.92-7.67); repeated head trauma (OR, 4.36; 95% CI, 3.69-5.15); equestrian sport (OR, 2.73; 95% CI, 1.64-4.51); and falls during sport activities (OR, 2.72; 95% CI, 1.67-4.46). The high incidence of sport-related TBI in youth, potential for repetitive mild TBI, and its long-term consequences on learning warrants coordinated surveillance activities and population-based outcome studies. Copyright © 2013 Elsevier Inc. All rights reserved.

Ground-based observation of near-Earth asteroids

NASA Technical Reports Server (NTRS)

Gaffey, Michael J.

1992-01-01

An increased ground-based observation program is an essential component of any serious attempt to assess the resource potential of near-Earth asteroids. A vigorous search and characterization program could lead to the discovery and description of about 400 to 500 near-Earth asteroids in the next 20 years. This program, in conjunction with meteorite studies, would provide the data base to ensure that the results of a small number of asteroid-rendezvous and sample-return missions could be extrapolated with confidence into a geological base map of the Aten, Apollo, and Amor asteroids. Ground-based spectral studies of nearly 30 members of the Aten/Apollo/Amor population provide good evidence that this class includes bodies composed of silicates, metal-silicates, and carbonaceous assemblages similar to those found in meteorites. The instruments that are being used or could be used to search for near-Earth asteroids are listed. Techniques useful in characterizing asteroids and the types of information obtainable using these techniques are listed.

Wastewater-based epidemiology to assess human exposure to pyrethroid pesticides.

PubMed

Rousis, Nikolaos I; Zuccato, Ettore; Castiglioni, Sara

2017-02-01

Pesticides are active substances with potentially adverse effects on human health, and therefore great effort is addressed to study the relation between their widespread use and the effects on humans. To track human exposure to pesticides, novel approaches are needed to give additional information on exposure at population level. In this study, a novel application of Wastewater-Based Epidemiology (WBE) was developed to measure the intake of pyrethroid pesticides in a population. Three human urinary metabolites of pyrethroids were selected and validated as biomarkers of exposure by evaluating their sources and stability in wastewater. They were measured by liquid chromatography-tandem mass spectrometry in raw urban wastewater collected from the wastewater treatment plants of six Italian cities. Their concentrations were used as biomarkers to back-calculate the intake of pyrethroid pesticides in the population. WBE results were in line with the urinary biomarker levels of biomonitoring studies considering dilution in wastewater. Significant differences in the metabolites levels were observed among different cities. Seasonal variations in human intake of pyrethroids were also seen, as expected, with higher intakes during spring/summer. Intakes in the six cities were compared with the acceptable daily intake (ADI) and it was concluded that some of the populations examined might face significant health risks. Results confirm that this method can provide supplementary information to biomonitoring studies and can be a valuable tool for obtaining objective, direct information on the real levels of exposure to pyrethroids of different populations. Copyright © 2016 Elsevier Ltd. All rights reserved.

The healthy migrant effect in primary care.

PubMed

Gimeno-Feliu, Luis A; Calderón-Larrañaga, Amaia; Diaz, Esperanza; Poblador-Plou, Beatriz; Macipe-Costa, Rosa; Prados-Torres, Alexandra

2015-01-01

To compare the morbidity burden of immigrants and natives residing in Aragón, Spain, based on patient registries in primary care, which represents individuals' first contact with the health system. A retrospective observational study was carried out, based on linking electronic primary care medical records to patients' health insurance cards. The study population consisted of the entire population assigned to general practices in Aragón, Spain (1,251,540 individuals, of whom 12% were immigrants). We studied the morbidity profiles of both the immigrant and native populations using the Adjusted Clinical Group System. Logistic regressions were conducted to compare the morbidity burden of immigrants and natives after adjustment for age and gender. Our study confirmed the "healthy immigrant effect", particularly for immigrant men. Relative to the native population, the prevalence rates of the most frequent diseases were lower among immigrants. The percentage of the population showing a moderate to very high morbidity burden was higher among natives (52%) than among Latin Americans (33%), Africans (29%), western Europeans (27%), eastern Europeans and North Americans (26%) and/or Asians (20%). Differences were smaller for immigrants who had lived in the country for 5 years or longer. Length of stay in the host country had a decisive influence on the morbidity burden represented by immigrants, although the health status of both men and women worsened with longer stay in the host country. Copyright © 2014 SESPAS. Published by Elsevier Espana. All rights reserved.

Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case–control study in four Nordic countries

PubMed Central

Farioli, Andrea; Straif, Kurt; Brandi, Giovanni; Curti, Stefania; Kjaerheim, Kristina; Martinsen, Jan Ivar; Sparen, Pär; Tryggvadottir, Laufey; Weiderpass, Elisabete; Biasco, Guido; Violante, Francesco Saverio; Mattioli, Stefano; Pukkala, Eero

2018-01-01

Objectives To assess the association between occupational exposure to asbestos and the risk of cholangiocarcinoma (CC). Methods We conducted a case–control study nested in the Nordic Occupational Cancer (NOCCA) cohort. We studied 1458 intrahepatic CC (ICC) and 3972 extrahepatic CC (ECC) cases occurring among subjects born in 1920 or later in Finland, Iceland, Norway and Sweden. Each case was individually matched by birth year, gender and country to five population controls. The cumulative exposure to asbestos (measured in fibres (f)/ml × years) was assessed by applying the NOCCA job-exposure matrix to data on occupations collected during national population censuses (conducted in 1960, 1970, 1980/81 and 1990). Odds ratios (OR) and 95% CI were estimated using conditional logistic regression models adjusted by printing industry work. Results We observed an increasing risk of ICC with cumulative exposure to asbestos: never exposed, OR 1.0 (reference category); 0.1–4.9 f/mL × years, OR 1.1 (95% CI 0.9 to 1.3); 5.0–9.9 f/mL × years, OR 1.3 (95% CI 0.9 to 2.1); 10.0–14.9 f/mL × years, OR 1.6 (95% CI 1.0 to 2.5); ≥15.0 f/mL × years, OR 1.7 (95% CI 1.1 to 2.6). We did not observe an association between cumulative asbestos exposure and ECC. Conclusions Our study provides evidence that exposure to asbestos might be a risk factor for ICC. Our findings also suggest that the association between ECC and asbestos is null or weaker than that observed for ICC. Further studies based on large industrial cohorts of asbestos workers and possibly accounting for personal characteristics and clinical history are needed. PMID:29133597

Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case-control study in four Nordic countries.

PubMed

Farioli, Andrea; Straif, Kurt; Brandi, Giovanni; Curti, Stefania; Kjaerheim, Kristina; Martinsen, Jan Ivar; Sparen, Pär; Tryggvadottir, Laufey; Weiderpass, Elisabete; Biasco, Guido; Violante, Francesco Saverio; Mattioli, Stefano; Pukkala, Eero

2018-03-01

To assess the association between occupational exposure to asbestos and the risk of cholangiocarcinoma (CC). We conducted a case-control study nested in the Nordic Occupational Cancer (NOCCA) cohort. We studied 1458 intrahepatic CC (ICC) and 3972 extrahepatic CC (ECC) cases occurring among subjects born in 1920 or later in Finland, Iceland, Norway and Sweden. Each case was individually matched by birth year, gender and country to five population controls. The cumulative exposure to asbestos (measured in fibres (f)/ml × years) was assessed by applying the NOCCA job-exposure matrix to data on occupations collected during national population censuses (conducted in 1960, 1970, 1980/81 and 1990). Odds ratios (OR) and 95% CI were estimated using conditional logistic regression models adjusted by printing industry work. We observed an increasing risk of ICC with cumulative exposure to asbestos: never exposed, OR 1.0 (reference category); 0.1-4.9 f/mL × years, OR 1.1 (95% CI 0.9 to 1.3); 5.0-9.9 f/mL × years, OR 1.3 (95% CI 0.9 to 2.1); 10.0-14.9 f/mL × years, OR 1.6 (95% CI 1.0 to 2.5); ≥15.0 f/mL × years, OR 1.7 (95% CI 1.1 to 2.6). We did not observe an association between cumulative asbestos exposure and ECC. Our study provides evidence that exposure to asbestos might be a risk factor for ICC. Our findings also suggest that the association between ECC and asbestos is null or weaker than that observed for ICC. Further studies based on large industrial cohorts of asbestos workers and possibly accounting for personal characteristics and clinical history are needed. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Quantification of the genetic change in the transition of Rhodnius pallescens Barber, 1932 (Hemiptera: Reduviidae) from field to laboratory.

PubMed

Gómez-Sucerquia, Leysa Jackeline; Triana-Chávez, Omar; Jaramillo-Ocampo, Nicolás

2009-09-01

Previous studies have reported genetic differences between wild-caught sylvatic, domestic and laboratory pop-ulations of several Triatominae species. The differences between sylvatic and laboratory colonies parallel are similar to the differences observed between sylvatic and domestic populations. Laboratory colonies are frequently used as references for field populations, but the consequences of founder events on the genetic makeup of laboratory or domestic populations are rarely quantified. Our goal was to quantify the genetic change in Rhodnius pallescens populations artificially submitted to founder effects via laboratory colonization. We compared the genetic makeup of two sylvatic populations and their laboratory descendants using a panel of 10 microsatellite markers. Both sylvatic populations were initially collected from palm trees, but the colonies differed in the number of founder insects and amount of time kept in the laboratory. We evaluated allelic polymorphism, differences between expected and observed heterozygosity, estimates of population differentiation (Fst) and inbreeding (Fis, Fit) and cluster analyses based on Nei's distances. We found a unique genetic structure for each sample population, with significant differentiation between the field insects and each of the laboratory generations. These analyses showed strong founder effects and showed that genetic drift had led to a genetic equilibrium over several generations of isolation. Our results suggest that laboratory colonies of R. pallescens have a different genetic structure than their wild relatives and similar processes likely affect other Triatominae laboratory stocks.

Restitution and genetic differentiation of salmon populations in the southern Baltic genotyped with the Atlantic salmon 7K SNP array.

PubMed

Poćwierz-Kotus, Anita; Bernaś, Rafał; Kent, Matthew P; Lien, Sigbjørn; Leliűna, Egidijus; Dębowski, Piotr; Wenne, Roman

2015-05-06

Native populations of Atlantic salmon in Poland, from the southern Baltic region, became extinct in the 1980s. Attempts to restitute salmon populations in Poland have been based on a Latvian salmon population from the Daugava river. Releases of hatchery reared smolts started in 1986, but to date, only one population with confirmed natural reproduction has been observed in the Slupia river. Our aim was to investigate the genetic differentiation of salmon populations in the southern Baltic using a 7K SNP (single nucleotide polymorphism) array in order to assess the impact of salmon restitution in Poland. One hundred and forty salmon samples were collected from: the Polish Slupia river including wild salmon and individuals from two hatcheries, the Swedish Morrum river and the Lithuanian Neman river. All samples were genotyped using an Atlantic salmon 7K SNP array. A set of 3218 diagnostic SNPs was used for genetic analyses. Genetic structure analyses indicated that the individuals from the investigated populations were clustered into three groups i.e. one clade that included individuals from both hatcheries and the wild population from the Polish Slupia river, which was clearly separated from the other clades. An assignment test showed that there were no stray fish from the Morrum or Neman rivers in the sample analyzed from the Slupia river. Global FST over polymorphic loci was high (0.177). A strong genetic differentiation was observed between the Lithuanian and Swedish populations (FST = 0.28). Wild juvenile salmon specimens that were sampled from the Slupia river were the progeny of fish released from hatcheries and, most likely, were not progeny of stray fish from Sweden or Lithuania. Strong genetic differences were observed between the salmon populations from the three studied locations. Our recommendation is that future stocking activities that aim at restituting salmon populations in Poland include stocking material from the Lithuanian Neman river because of its closer geographic proximity.

Basal cell skin cancer and the risk of second primary cancers: a cancer registry-based study in Lithuania.

PubMed

Krilaviciute, Agne; Vincerzevskiene, Ieva; Smailyte, Giedre

2016-07-01

The aim of this population-based cohort study was to determine the risk of second primary cancer in basal cell carcinoma (BCC) patients in Lithuania. This analysis was based on patients diagnosed with BCC in Lithuania between 1998 and 2007 and followed until 2011. Standardized incidence ratios for subsequent cancers as a ratio of observed number of cancer cases in people with previous BCC diagnosis to the expected number of cancer cases in the underlying general population were calculated. After diagnosis of BCC, 1442 new cases of selected cancers were diagnosed. Compared with the general population, the incidence of all new primaries combined after BCC was very close to expected. Statistically meaningful increase in developing subsequent cancer was obtained for Hodgkin's lymphoma, prostate cancer, and leukemia in men, and for cancers of the lip, lung, and breast in women. Risk of melanoma and thyroid cancer was significantly elevated in both sexes. Relative risk of cancer of the eye was increased although not significant. In our study, we found increased cancer risk for cancers related to sun exposure. In addition, increased risks were identified for Hodgkin's lymphoma, thyroid cancer, leukemia, prostate, and breast cancer in BCC patients. Copyright © 2016 Elsevier Inc. All rights reserved.

Morphological adaptation to climate in modern Homo sapiens crania: the importance of basicranial breadth.

PubMed

Nowaczewska, Wioletta; Dabrowski, Paweł; Kuźmiński, Łukasz

2011-09-01

The aim of this study is to investigate whether the variation in breadth of the cranial base among modern human populations that inhabit different regions of the world is linked with climatic adaptation. This work provides an examination of two hypotheses. The first hypothesis is that the correlation between basicranial breadth and ambient temperature is stronger than the correlation between temperature and other neurocranial variables, such as maximum cranial breadth, maximum neurocranial length, and the endocranial volume. The second hypothesis is that the correlation between the breadth of the cranial base and the ambient temperature is significant even when other neurocranial features used in this study (including the size of the neurocranium) are constant. For the sake of this research, the necessary neurocranial variables for fourteen human populations living in diverse environments were obtained from Howells' data (except for endocranial volume which was obtained by means of estimation). The ambient temperature (more precisely, the mean yearly temperature) of the environments inhabited by these populations was used as a major climatic factor. Data were analysed using Pearson correlation coefficients, linear regression and partial correlation analyses. The results supported the two hypotheses, thus suggesting that ambient temperature may contribute to the observed differences in the breadth of the cranial base in the studied modern humans.

Probabilistic atlas and geometric variability estimation to drive tissue segmentation.

PubMed

Xu, Hao; Thirion, Bertrand; Allassonnière, Stéphanie

2014-09-10

Computerized anatomical atlases play an important role in medical image analysis. While an atlas usually refers to a standard or mean image also called template, which presumably represents well a given population, it is not enough to characterize the observed population in detail. A template image should be learned jointly with the geometric variability of the shapes represented in the observations. These two quantities will in the sequel form the atlas of the corresponding population. The geometric variability is modeled as deformations of the template image so that it fits the observations. In this paper, we provide a detailed analysis of a new generative statistical model based on dense deformable templates that represents several tissue types observed in medical images. Our atlas contains both an estimation of probability maps of each tissue (called class) and the deformation metric. We use a stochastic algorithm for the estimation of the probabilistic atlas given a dataset. This atlas is then used for atlas-based segmentation method to segment the new images. Experiments are shown on brain T1 MRI datasets. Copyright © 2014 John Wiley & Sons, Ltd.

Study design and "evidence" in patient-oriented research.

PubMed

Concato, John

2013-06-01

Individual studies in patient-oriented research, whether described as "comparative effectiveness" or using other terms, are based on underlying methodological designs. A simple taxonomy of study designs includes randomized controlled trials on the one hand, and observational studies (such as case series, cohort studies, and case-control studies) on the other. A rigid hierarchy of these design types is a fairly recent phenomenon, promoted as a tenet of "evidence-based medicine," with randomized controlled trials receiving gold-standard status in terms of producing valid results. Although randomized trials have many strengths, and contribute substantially to the evidence base in clinical care, making presumptions about the quality of a study based solely on category of research design is unscientific. Both the limitations of randomized trials as well as the strengths of observational studies tend to be overlooked when a priori assumptions are made. This essay presents an argument in support of a more balanced approach to evaluating evidence, and discusses representative examples from the general medical as well as pulmonary and critical care literature. The simultaneous consideration of validity (whether results are correct "internally") and generalizability (how well results apply to "external" populations) is warranted in assessing whether a study's results are accurate for patients likely to receive the intervention-examining the intersection of clinical and methodological issues in what can be called a medicine-based evidence approach. Examination of cause-effect associations in patient-oriented research should recognize both the strengths and limitations of randomized trials as well as observational studies.

Incidence of low and high-energy fractures in persons with and without HIV infection: a Danish population-based cohort study.

PubMed

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.

Observational studies using propensity score analysis underestimated the effect sizes in critical care medicine.

PubMed

Zhang, Zhongheng; Ni, Hongying; Xu, Xiao

2014-08-01

Propensity score (PS) analysis has been increasingly used in critical care medicine; however, its validation has not been systematically investigated. The present study aimed to compare effect sizes in PS-based observational studies vs. randomized controlled trials (RCTs) (or meta-analysis of RCTs). Critical care observational studies using PS were systematically searched in PubMed from inception to April 2013. Identified PS-based studies were matched to one or more RCTs in terms of population, intervention, comparison, and outcome. The effect sizes of experimental treatments were compared for PS-based studies vs. RCTs (or meta-analysis of RCTs) with sign test. Furthermore, ratio of odds ratio (ROR) was calculated from the interaction term of treatment × study type in a logistic regression model. A ROR < 1 indicates greater benefit for experimental treatment in RCTs compared with PS-based studies. RORs of each comparison were pooled by using meta-analytic approach with random-effects model. A total of 20 PS-based studies were identified and matched to RCTs. Twelve of the 20 comparisons showed greater beneficial effect for experimental treatment in RCTs than that in PS-based studies (sign test P = 0.503). The difference was statistically significant in four comparisons. ROR can be calculated from 13 comparisons, of which four showed significantly greater beneficial effect for experimental treatment in RCTs. The pooled ROR was 0.71 (95% CI: 0.63, 0.79; P = 0.002), suggesting that RCTs (or meta-analysis of RCTs) were more likely to report beneficial effect for the experimental treatment than PS-based studies. The result remained unchanged in sensitivity analysis and meta-regression. In critical care literature, PS-based observational study is likely to report less beneficial effect of experimental treatment compared with RCTs (or meta-analysis of RCTs). Copyright © 2014 Elsevier Inc. All rights reserved.

Tracing the Trans-Pacific Evolutionary History of a Domesticated Seaweed (Gracilaria chilensis) with Archaeological and Genetic Data

PubMed Central

Guillemin, Marie-Laure; Valero, Myriam; Faugeron, Sylvain; Nelson, Wendy; Destombe, Christophe

2014-01-01

The history of a domesticated marine macroalga is studied using archaeological, phylogeographic and population genetic tools. Phylogeographic and population genetic analyses demonstrated that the cultivated red alga Gracilaria chilensis colonised the Chilean coast from New Zealand. Combining archaeological observations with phylogeographic data provided evidence that exchanges between New Zealand and Chile have occurred at least before the Holocene, likely at the end of the Last Glacial Maximum (LGM) and we suggest that migration probably occurred via rafting. Furthermore, the remarkably low microsatellite diversity found in the Chilean populations compared to those in New Zealand is consistent with a recent genetic bottleneck as a result of over-exploitation of natural populations and/or the process of domestication. Therefore, the aquaculture of this seaweed, based essentially on clonal propagation, is occurring from genetically depressed populations and may be driving the species to an extinction vortex in Chile. PMID:25501717

Geographical patterns of Kaposi's sarcoma, nonHodgkin lymphomas, and cervical cancer associated with HIV infection in five African populations.

PubMed

Chaabna, Karima; Boniol, Mathieu; de Vuyst, Hugo; Vanhems, Philippe; Antônio de Ávila Vitoria, Marco; Curado, Maria-Paula

2012-01-01

The objective of this study is to describe the most recent geographical patterns of incidence of AIDS-related cancers, Kaposi's sarcoma (KS), nonHodgkin lymphoma (NHL), and cervical cancer in North African and subSaharan African populations. Data were extracted for the period 1998-2002 from five African population-based cancer registries: Kyadondo, Harare, Setif, Sousse, and Gharbiah. Age-standardized rates were calculated using the African standard population; a comparison was made between these populations by computing the standardized incidence ratio and 95% confidence intervals. The KS rate was found to be significantly higher in men than in women, and higher in Harare (women: 26.3/100,000; men: 50.4/100,000) and Kyadondo (women: 23.6/100,000; men: 30.2/100,000) than in the North African sites for both sexes (<0.3/100,000). In addition, the KS rate in women from Harare was similar to that for Kyadondo. Gharbiah presented the highest rates for NHL (women: 7 per 100,000; men: 11.9/100,000) for both sexes. We observed that Harare and Kyadondo had similar age-specific incidence in the high-risk age group for HIV/AIDS (15-49 years), and these rates were 4.5-fold higher in subSaharan populations than those in the North African sites. Thus, it was observed that the pattern of HIV prevalence is variable with the lowest prevalence in North African countries, intermediate prevalence in Uganda, and the highest prevalence in Zimbabwe. Our findings show that the incidence of NHL and cervical cancer, considered to be HIV/AIDS-related cancers, does not follow the pattern of HIV prevalence in the five studied African populations. Thus, the highest NHL incidence rate in both sexes in Gambia may be explained, at least in great part, by the highest hepatitis C virus prevalence observed there. Indeed, factors other than HIV infection likely contribute to their geographical patterns.

Genetic Diversity and Population Structure of Leishmania infantum from Southeastern France: Evaluation Using Multi-Locus Microsatellite Typing

PubMed Central

Pomares, Christelle; Marty, Pierre; Bañuls, Anne Laure; Lemichez, Emmanuel; Pratlong, Francine; Faucher, Benoît; Jeddi, Fakhri; Moore, Sandy; Michel, Grégory; Aluru, Srikanth; Piarroux, Renaud; Hide, Mallorie

2016-01-01

In the south of France, Leishmania infantum is responsible for numerous cases of canine leishmaniasis (CanL), sporadic cases of human visceral leishmaniasis (VL) and rare cases of cutaneous and muco-cutaneous leishmaniasis (CL and MCL, respectively). Several endemic areas have been clearly identified in the south of France including the Pyrénées-Orientales, Cévennes (CE), Provence (P), Alpes-Maritimes (AM) and Corsica (CO). Within these endemic areas, the two cities of Nice (AM) and Marseille (P), which are located 150 km apart, and their surroundings, concentrate the greatest number of French autochthonous leishmaniasis cases. In this study, 270 L. infantum isolates from an extended time period (1978–2011) from four endemic areas, AM, P, CE and CO, were assessed using Multi-Locus Microsatellite Typing (MLMT). MLMT revealed a total of 121 different genotypes with 91 unique genotypes and 30 repeated genotypes. Substantial genetic diversity was found with a strong genetic differentiation between the Leishmania populations from AM and P. However, exchanges were observed between these two endemic areas in which it seems that strains spread from AM to P. The genetic differentiations in these areas suggest strong epidemiological structuring. A model-based analysis using STRUCTURE revealed two main populations: population A (consisting of samples primarily from the P and AM endemic areas with MON-1 and non-MON-1 strains) and population B consisting of only MON-1 strains essentially from the AM endemic area. For four patients, we observed several isolates from different biological samples which provided insight into disease relapse and re-infection. These findings shed light on the transmission dynamics of parasites in humans. However, further data are required to confirm this hypothesis based on a limited sample set. This study represents the most extensive population analysis of L. infantum strains using MLMT conducted in France. PMID:26808522

Change in genetic size of small-closed populations: Lessons from a domestic mammal population.

PubMed

Ghafouri-Kesbi, Farhad

2010-10-01

The aim of this study was to monitor changes in genetic size of a small-closed population of Iranian Zandi sheep, by using pedigree information from animals born between 1991 and 2005. The genetic size was assessed by using measures based on the probability of identity-by-descend of genes (coancestry, f, and effective population size, N(e) ), as well as measures based on probability of gene origin (effective number of founders, f(e) , effective number of founder genomes, f(g) , and effective number of non-founder genomes, f(ne) ). Average coancestry, or the degree of genetic similarity of individuals, increased from 0.81% to 1.44% during the period 1993 to 2005, at the same time that N(e) decreased from 263 to 93. The observed trend for f(e) was irregular throughout the experiment in a way that f(e) was 68, 87, 77, 92, and 80 in 1993, 1996, 1999, 2002, and 2005, respectively. Simultaneously, f(g) , the most informative effective number, decreased from 61 to 35. The index of genetic diversity (GD) which was obtained from estimates of f(g) , decreased about 2% throughout the period studied. In addition, a noticeable reduction was observed in the estimates of f(ne) from 595 in 1993 to 61 in 2005. The higher than 1 ratio of f(e) to f(g) indicated the presence of bottlenecks and genetic drift in the development of this population of Zandi sheep. From 1993 to 1999, f(ne) was much higher than f(e) , thereby indicating that with respect to loss of genetic diversity, the unequal contribution of founders was more important than the random genetic drift in non-founder generations. Subsequently, random genetic drift in non-founder generations was the major reason for f(e) > f(ne) . The minimization of average coancestry in new reproductive individuals was recommended as a means of preserving the population against a further loss in genetic diversity.

"Lies, damned lies ..." and observational studies in comparative effectiveness research.

PubMed

Albert, Richard K

2013-06-01

A new federal initiative has allocated $1.1 billion to comparative effectiveness research, and many have emphasized the importance of including observational studies in this effort. The rationale for using observational studies to assess comparative effectiveness is based on concerns that randomized controlled trials (RCTs) are not "real world" because they enroll homogeneous patient populations, measure study outcomes that are not important to patients, use protocols that are overly complex, are conducted in specialized centers, and use study treatments that are not consistent with usual care, and that RCTs are not always feasible because of a lack of equipoise, the need to assess delayed endpoints, and concerns that they take years to complete and are expensive. This essay questions the validity of each of these proposed limitations, summarizes concerns raised about the accuracy of results generated by observational studies, provides some examples of discrepancies between results of observational studies and RCTs that pertain to pulmonary and critical care, and suggests that using observational studies for comparative effectiveness research may increase rather than decrease the cost of health care and may harm patients.

TESTING STELLAR POPULATION SYNTHESIS MODELS WITH SLOAN DIGITAL SKY SURVEY COLORS OF M31's GLOBULAR CLUSTERS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.

2011-08-10

Accurate stellar population synthesis models are vital in understanding the properties and formation histories of galaxies. In order to calibrate and test the reliability of these models, they are often compared with observations of star clusters. However, relatively little work has compared these models in the ugriz filters, despite the recent widespread use of this filter set. In this paper, we compare the integrated colors of globular clusters in the Sloan Digital Sky Survey (SDSS) with those predicted from commonly used simple stellar population (SSP) models. The colors are based on SDSS observations of M31's clusters and provide the largestmore » population of star clusters with accurate photometry available from the survey. As such, it is a unique sample with which to compare SSP models with SDSS observations. From this work, we identify a significant offset between the SSP models and the clusters' g - r colors, with the models predicting colors which are too red by g - r {approx} 0.1. This finding is consistent with previous observations of luminous red galaxies in the SDSS, which show a similar discrepancy. The identification of this offset in globular clusters suggests that it is very unlikely to be due to a minority population of young stars. The recently updated SSP model of Maraston and Stroembaeck better represents the observed g - r colors. This model is based on the empirical MILES stellar library, rather than theoretical libraries, suggesting an explanation for the g - r discrepancy.« less

Incidence of breast cancer and estimates of overdiagnosis after the initiation of a population-based mammography screening program.

PubMed

Coldman, Andrew; Phillips, Norm

2013-07-09

There has been growing interest in the overdiagnosis of breast cancer as a result of mammography screening. We report incidence rates in British Columbia before and after the initiation of population screening and provide estimates of overdiagnosis. We obtained the numbers of breast cancer diagnoses from the BC Cancer Registry and screening histories from the Screening Mammography Program of BC for women aged 30-89 years between 1970 and 2009. We calculated age-specific rates of invasive breast cancer and ductal carcinoma in situ. We compared these rates by age, calendar period and screening participation. We obtained 2 estimates of overdiagnosis from cumulative cancer rates among women between the ages of 40 and 89 years: the first estimate compared participants with nonparticipants; the second estimate compared observed and predicted population rates. We calculated participation-based estimates of overdiagnosis to be 5.4% for invasive disease alone and 17.3% when ductal carcinoma in situ was included. The corresponding population-based estimates were -0.7% and 6.7%. Participants had higher rates of invasive cancer and ductal carcinoma in situ than nonparticipants but lower rates after screening stopped. Population incidence rates for invasive cancer increased after 1980; by 2009, they had returned to levels similar to those of the 1970s among women under 60 years of age but remained elevated among women 60-79 years old. Rates of ductal carcinoma in situ increased in all age groups. The extent of overdiagnosis of invasive cancer in our study population was modest and primarily occurred among women over the age of 60 years. However, overdiagnosis of ductal carcinoma in situ was elevated for all age groups. The estimation of overdiagnosis from observational data is complex and subject to many influences. The use of mammography screening in older women has an increased risk of overdiagnosis, which should be considered in screening decisions.

Assessing the potential spread and maintenance of foot-and-mouth disease virus infection in wild ungulates: general principles and application to a specific scenario in Thrace.

PubMed

Dhollander, S; Belsham, G J; Lange, M; Willgert, K; Alexandrov, T; Chondrokouki, E; Depner, K; Khomenko, S; Özyörük, F; Salman, M; Thulke, H H; Bøtner, A

2016-04-01

Foot-and-mouth disease (FMD), due to infection with serotype O virus, occurred in wild boar and within eleven outbreaks in domestic livestock in the south-east of Bulgaria, Thrace region, in 2011. Hence, the issue of the potential for the spread and maintenance of FMD virus (FMDV) infection in a population of wild ungulates became important. This assessment focused on the spread and maintenance of FMDV infection within a hypothetical wild boar and deer population in an environment, which is characterized by a climate transitional between Mediterranean and continental and variable wildlife population densities. The assessment was based on three aspects: (i) a systematic review of the literature focusing on experimental infection studies to identify the parameters describing the duration of FMDV infection in deer and wild boar, as well as observational studies assessing the occurrence of FMDV infection in wild deer and wild boar populations, (ii) prevalence survey data of wild boar and deer in Bulgaria and Turkey and (iii) an epidemiological model, simulating the host-to-host spread of FMDV infections. It is concluded, based on all three aspects, that the wildlife population in Thrace, and so wildlife populations in similar ecological settings, are probably not able to maintain FMD in the long term in the absence of FMDV infection in the domestic host population. However, limited spread of FMDV infection in time and space in the wildlife populations can occur. If there is a continued cross-over of FMDV between domestic and wildlife populations or a higher population density, virus circulation may be prolonged. © 2014 Blackwell Verlag GmbH.

The Solid Rocket Motor Slag Population: Results of a Radar-based Regressive Statistical Evaluation

NASA Technical Reports Server (NTRS)

Horstman, Matthew F.; Xu, Yu-Lin

2008-01-01

Solid rocket motor (SRM) slag has been identified as a significant source of man-made orbital debris. The propensity of SRMs to generate particles of 100 m and larger has caused concern regarding their contribution to the debris environment. Radar observation, rather than in-situ gathered evidence, is currently the only measurable source for the NASA/ODPO model of the on-orbit slag population. This simulated model includes the time evolution of the resultant orbital populations using a historical database of SRM launches, propellant masses, and estimated locations and times of tail-off. However, due to the small amount of observational evidence, there can be no direct comparison to check the validity of this model. Rather than using the assumed population developed from purely historical and physical assumptions, a regressional approach was used which utilized the populations observed by the Haystack radar from 1996 to present. The estimated trajectories from the historical model of slag sources, and the corresponding plausible detections by the Haystack radar, were identified. Comparisons with observational data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the historical data obtained. The result is a model SRM population that fits within the bounds of the observed environment.

Distribution of CYP2D6 and CYP2C19 Polymorphisms Associated with Poor Metabolizer Phenotype in Five Amerindian Groups and Western Mestizos from Mexico

PubMed Central

Salazar-Flores, Joel; Torres-Reyes, Luis A.; Martínez-Cortés, Gabriela; Rubi-Castellanos, Rodrigo; Sosa-Macías, Martha; Muñoz-Valle, José F.; González-González, César; Ramírez, Angélica; Román, Raquel; Méndez, José L.; Barrera, Andrés; Torres, Alfredo; Medina, Rafael

2012-01-01

Background: The distribution of polymorphisms in the CYP2D6 and CYP2C19 genes allows inferring the potential risk for specific adverse drug reactions and lack of therapeutic effects in humans. This variability shows differences among human populations. The aim of this study was to analyze single-nucleotide polymorphisms related to a poor metabolizer (PM) phenotype in nonpreviously studied Amerindian groups and Mestizos (general admixed population) from Mexico. Methods: We detected by SNaPshot® different polymorphisms located in CYP2D6 (*3, *4, *6, *7, and *8) and CYP2C19 (*2, *3, *4 and *5) in western Mestizos (n=145) and five Amerindian groups from Mexico: Tarahumaras from the North (n=88); Purépechas from the Center (n=101); and Tojolabales (n=68), Tzotziles (n=88), and Tzeltales (n=20) from the Southeast. Genotypes were observed by capillary electrophoresis. The genetic relationships among these populations were estimated based on these genes. Results and Discussion: The wild-type allele (*1) of both genes was predominant in the Mexican populations studied. The most widely observed alleles were CYP2C19*2 (range, 0%–31%) and CYP2D6*4 (range, 1.2%–7.3%), whereas CYP2D6*3 was exclusively detected in Mestizos. Conversely, CYP2C19*4 and *5, as well as CYP2D6*3, *6, *7, and *8, were not observed in the majority of the Mexican populations. The Tarahumaras presented a high frequency of the allele CYP2C19*2 (31%) and of homozygotes *2/*2 (10.7%), which represent a high frequency of potentially PM phenotypes in this Amerindian group. The genetic distances showed high differentiation of Tarahumaras (principally for CYP2C19 gene). In general, a relative proximity was observed between most of the Amerindian, Mexican-Mestizo, and Latin-American populations. Conclusion: In general, the wild-type allele (*1) predominates in Mexican populations, outlining a relatively homogeneous distribution for CYP2C19 and CYP2D6. The exception is the Tarahumara group that displays a potentially increased risk for adverse reactions to CYP2C19-metabolized drugs. PMID:22913530

An AFM-based pit-measuring method for indirect measurements of cell-surface membrane vesicles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Xiaojun; Department of Biotechnology, Nanchang University, Nanchang, Jiangxi 330031; Chen, Yuan

2014-03-28

Highlights: • Air drying induced the transformation of cell-surface membrane vesicles into pits. • An AFM-based pit-measuring method was developed to measure cell-surface vesicles. • Our method detected at least two populations of cell-surface membrane vesicles. - Abstract: Circulating membrane vesicles, which are shed from many cell types, have multiple functions and have been correlated with many diseases. Although circulating membrane vesicles have been extensively characterized, the status of cell-surface membrane vesicles prior to their release is less understood due to the lack of effective measurement methods. Recently, as a powerful, micro- or nano-scale imaging tool, atomic force microscopy (AFM)more » has been applied in measuring circulating membrane vesicles. However, it seems very difficult for AFM to directly image/identify and measure cell-bound membrane vesicles due to the similarity of surface morphology between membrane vesicles and cell surfaces. Therefore, until now no AFM studies on cell-surface membrane vesicles have been reported. In this study, we found that air drying can induce the transformation of most cell-surface membrane vesicles into pits that are more readily detectable by AFM. Based on this, we developed an AFM-based pit-measuring method and, for the first time, used AFM to indirectly measure cell-surface membrane vesicles on cultured endothelial cells. Using this approach, we observed and quantitatively measured at least two populations of cell-surface membrane vesicles, a nanoscale population (<500 nm in diameter peaking at ∼250 nm) and a microscale population (from 500 nm to ∼2 μm peaking at ∼0.8 μm), whereas confocal microscopy only detected the microscale population. The AFM-based pit-measuring method is potentially useful for studying cell-surface membrane vesicles and for investigating the mechanisms of membrane vesicle formation/release.« less

Space observations for global and regional studies of the biosphere

NASA Technical Reports Server (NTRS)

Cihlar, J.; Li, Z.; Chen, J.; Sellers, P.; Hall, F.

1994-01-01

The capability to make space-based measurements of Earth at high spatial and temporal resolutions, which would not otherwise be economically or practically feasible, became available just in time to contribute to scientific understanding of the interactive processes governing the total Earth system. Such understanding has now become essential in order to take practical steps which would counteract or mitigate the pervasive impact of the growing human population on the future habitability of the Earth. The paper reviews the rationale for using space observations for studies of climate and terrestrial ecosystems at global and regional scales, as well as the requirements for such observations for studies of climate and ecosystem dynamics. The present status of these developments is reported along with initiatives under way to advance the use of satellite observations for Earth system studies. The most important contribution of space observations is the provision of physical or biophysical parameters for models representing various components of the Earth system. Examples of such parameters are given for climatic and ecosystem studies.

Incidence and survival time trends for Spanish children and adolescents with leukaemia from 1983 to 2007.

PubMed

Marcos-Gragera, R; Galceran, J; Martos, C; de Munain, A L; Vicente-Raneda, M; Navarro, C; Quirós-Garcia, J R; Sánchez, M-J; Ardanaz, E; Ramos, M; Mateos, A; Salmerón, D; Felipe, S; Peris-Bonet, R

2017-03-01

We have analysed incidence and survival trends of children and adolescents with leukaemia registered in Spanish population-based cancer registries during the period 1983-2007. Childhood and adolescent leukaemia cases were drawn from the 11 Spanish population-based cancer registries. For survival, registries with data for the period 1991-2005 and follow-up until 31-12-2010 were included. Overall incidence trends were evaluated using joinpoint analysis. Observed survival rates were estimated using Kaplan-Meier, and trends were tested using the log-rank test. Based on 2606 cases (2274 children and 332 adolescents), the overall age-adjusted incidence rate (ASRw) of leukaemia was 47.9 cases per million child-years in children and 23.8 in adolescents. The ASRw of leukaemia increased with an annual percentage change of 9.6 % (95 % CI: 2.2-17.6) until 1990 followed by a stabilisation of rates. In adolescents, incidence did not increase. Five-year survival increased from 66 % in 1991-1995 to 76 % in 2001-2005. By age, survival was dramatically lower in infants (0) and adolescents (15-19) than in the other age groups and no improvement was observed. In both children and adolescents, differences in 5-year survival rates among major subgroups of leukaemias were significant. The increasing incidence trends observed in childhood leukaemias during the study period were confined to the beginning of the period. Remarkable improvements in survival have been observed in Spanish children with leukaemias. However, this improvement was not observed in infants and adolescents.

Genetic variation facilitates seedling establishment but not population growth rate of a perennial invader

PubMed Central

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

The episode of genetic drift defining the migration of humans out of Africa is derived from a large east African population size.

PubMed

Elhassan, Nuha; Gebremeskel, Eyoab Iyasu; Elnour, Mohamed Ali; Isabirye, Dan; Okello, John; Hussien, Ayman; Kwiatksowski, Dominic; Hirbo, Jibril; Tishkoff, Sara; Ibrahim, Muntaser E

2014-01-01

Human genetic variation particularly in Africa is still poorly understood. This is despite a consensus on the large African effective population size compared to populations from other continents. Based on sequencing of the mitochondrial Cytochrome C Oxidase subunit II (MT-CO2), and genome wide microsatellite data we observe evidence suggesting the effective size (Ne) of humans to be larger than the current estimates, with a foci of increased genetic diversity in east Africa, and a population size of east Africans being at least 2-6 fold larger than other populations. Both phylogenetic and network analysis indicate that east Africans possess more ancestral lineages in comparison to various continental populations placing them at the root of the human evolutionary tree. Our results also affirm east Africa as the likely spot from which migration towards Asia has taken place. The study reflects the spectacular level of sequence variation within east Africans in comparison to the global sample, and appeals for further studies that may contribute towards filling the existing gaps in the database. The implication of these data to current genomic research, as well as the need to carry out defined studies of human genetic variation that includes more African populations; particularly east Africans is paramount.

A population based study comparing changes in rotavirus burden on the Island of Ireland between a highly vaccinated population and an unvaccinated population.

PubMed

Armstrong, Gillian; Gallagher, Naomh; Cabrey, Paul; Graham, Adele M; McKeown, Paul J; Jackson, Sarah; Dallat, Mary; Smithson, Richard D

2016-09-07

Rotavirus infection is a leading cause of gastroenteritis in infants and children globally. Reductions in rotavirus activity have been observed following introduction of rotavirus vaccination programmes, however a reductions have also been reported in some unvaccinated countries. The Island of Ireland incorporates the two jurisdictions Northern Ireland (NI) and the Republic of Ireland (IE). Both have similarities in climate, demography, morbidity and mortality but distinct health administrations and vaccination policies. Rotarix was added to the childhood immunisation programme in NI on the 1 July 2013. IE have not introduced routine rotavirus vaccination to date. The aim of this population based ecological study was to evaluate the impact of the rotavirus vaccine on burden of rotavirus disease in NI, and to compare with IE as an unvaccinated control population. This will help determine if the changes seen were due to the rotavirus vaccine, or due to confounding factors. A number of population based measures of disease burden were compared in both jurisdictions pre-vaccine (six years; 2007/08-2012/13) and post-vaccine (two years; 2013/14-2014/15). The data sources included national rotavirus surveillance data based on laboratory reports/notifications; hospital admission data; and notifications of gastroenteritis in under 2year olds. In the post-vaccination period, rotavirus incidence in NI dropped by 54% while in IE it increased by 19% compared to the pre-vaccine period. Notifications of gastroenteritis in under 2s in NI declined by 53% and hospital admissions in under 5year olds in NI declined by 40% in the post vaccine period. This natural experiment demonstrated a significant reduction in rotavirus disease activity post-vaccine introduction in NI with associated reductions in healthcare utilisation, with a concurrent increase in rotavirus disease activity in the non-vaccinated population in IE. These findings support rotavirus vaccination as an effective measure to reduce childhood morbidity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Limitations of basing screening policies on screening trials: The US Preventive Services Task Force and Prostate Cancer Screening.

PubMed

Etzioni, Ruth; Gulati, Roman; Cooperberg, Matt R; Penson, David M; Weiss, Noel S; Thompson, Ian M

2013-04-01

The US Preventive Services Task Force recently recommended against prostate-specific antigen screening for prostate cancer based primarily on evidence from the European Randomized Study of Screening for Prostate Cancer (ERSPC) and the US Prostate, Lung, Colorectal, and Ovarian (PLCO) cancer screening trial. : To examine limitations of basing screening policy on evidence from screening trials. We reviewed published modeling studies that examined population and trial data. The studies (1) project the roles of screening and changes in primary treatment in the US mortality decline; (2) extrapolate the ERSPC mortality reduction to the long-term US setting; (3) estimate overdiagnosis based on US incidence trends; and (4) quantify the impact of control arm screening on PLCO mortality results. Screening plausibly explains 45% and changes in primary treatment can explain 33% of the US prostate cancer mortality decline. Extrapolating the ERSPC results to the long-term US setting implies an absolute mortality reduction at least 5 times greater than that observed in the trial. Approximately 28% of screen-detected cases are overdiagnosed in the United States versus 58% of screen-detected cases suggested by the ERSPC results. Control arm screening can explain the null result in the PLCO trial. Modeling studies indicate that population trends and trial results extended to the long-term population setting are consistent with greater benefit of prostate-specific antigen screening-and more favorable harm-benefit tradeoffs-than has been suggested by empirical trial evidence.

Memory and obesity affect the population dynamics of asexual freshwater planarians

NASA Astrophysics Data System (ADS)

Dunkel, Jörn; Talbot, Jared; Schötz, Eva-Maria

2011-04-01

Asexual reproduction in multicellular organisms is a complex biophysical process that is not yet well understood quantitatively. Here, we report a detailed population study for the asexual freshwater planarian Schmidtea mediterranea, which can reproduce via transverse fission due to a large stem cell contingent. Our long-term observations of isolated non-interacting planarian populations reveal that the characteristic fission waiting time distributions for head and tail fragments differ significantly from each other. The stochastic fission dynamics of tail fragments exhibits non-negligible memory effects, implying that an accurate mathematical description of future data should be based on non-Markovian tree models. By comparing the effective growth of non-interacting planarian populations with those of self-interacting populations, we are able to quantify the influence of interactions between flatworms and physical conditions on the population growth. A surprising result is the non-monotonic relationship between effective population growth rate and nutrient supply: planarians exhibit a tendency to become 'obese' if the feeding frequency exceeds a critical level, resulting in a decreased reproduction activity. This suggests that these flatworms, which possess many genes homologous to those of humans, could become a new model system for studying dietary effects on reproduction and regeneration in multicellular organisms.

Contributions of a group-based exercise program for coping with fibromyalgia: a qualitative study giving voice to female patients.

PubMed

Beltrán-Carrillo, Vicente J; Tortosa-Martínez, Juan; Jennings, George; Sánchez, Elena S

2013-01-01

Numerous quantitative studies have illustrated the potential usefulness of exercise programs for women with fibromyalgia. However, a deeper understanding of the physical and especially psychosocial benefits of exercise therapy from the subjective perspective of this population is still needed. This study was conducted with 25 women who had fibromyalgia and were participating in a nine-month, group-based exercise program. The aim was to provide an in-depth description and analysis of the perceived physical and psychosocial benefits of participation. Qualitative data were collected through observation, interviews, and focus groups. The exercise program not only alleviated the physical symptoms of fibromyalgia, but social interactions within the group helped to counteract the isolation, frustration, and depression often associated with this chronic condition. The data from this study may contribute to a deeper understanding of the benefits of exercise for women with fibromyalgia and might be useful for the improvement of future exercise programs for this population.

Genetic variation, population structure and linkage disequilibrium in Switchgrass with ISSR, SCoT and EST-SSR markers.

PubMed

Zhang, Yu; Yan, Haidong; Jiang, Xiaomei; Wang, Xiaoli; Huang, Linkai; Xu, Bin; Zhang, Xinquan; Zhang, Lexin

2016-01-01

To evaluate genetic variation, population structure, and the extent of linkage disequilibrium (LD), 134 switchgrass ( Panicum virgatum L.) samples were analyzed with 51 markers, including 16 ISSRs, 20 SCoTs, and 15 EST-SSRs. In this study, a high level of genetic variation was observed in the switchgrass samples and they had an average Nei's gene diversity index (H) of 0.311. A total of 793 bands were obtained, of which 708 (89.28 %) were polymorphic. Using a parameter marker index (MI), the efficiency of the three types of markers (ISSR, SCoT, and EST-SSR) in the study were compared and we found that SCoT had a higher marker efficiency than the other two markers. The 134 switchgrass samples could be divided into two sub-populations based on STRUCTURE, UPGMA clustering, and principal coordinate analyses (PCA), and upland and lowland ecotypes could be separated by UPGMA clustering and PCA analyses. Linkage disequilibrium analysis revealed an average r 2 of 0.035 across all 51 markers, indicating a trend of higher LD in sub-population 2 than that in sub-population 1 ( P  < 0.01). The population structure revealed in this study will guide the design of future association studies using these switchgrass samples.

Population regulation in Gyrodactylus salaris - Atlantic salmon (Salmo salar L.) interactions: testing the paradigm.

PubMed

Ramírez, Raúl; Bakke, Tor A; Harris, Philip D

2015-07-25

Gyrodactylus salaris is a directly transmitted ectoparasite that reproduces in situ on its fish host. Wild Norwegian (East Atlantic) salmon stocks are thought to be especially susceptible to the parasite due to lack of co-adaptation, contrary to Baltic salmon stocks. This study i) identifies whether time- and density-dependent mechanisms in gyrodactylid population growth exist in G. salaris-Atlantic salmon interactions and ii) based on differences between Norwegian and Baltic stocks, determines whether the 'Atlantic susceptible, Baltic resistant' paradigm holds as an example of local adaptation. A total of 18 datasets of G. salaris population growth on individually isolated Atlantic salmon (12 different stocks) infected with three parasite strains were re-analysed using a Bayesian approach. Datasets included over 2000 observations of 388 individual fish. The best fitting model of population growth was time-limited; parasite population growth rate declined consistently from the beginning of infection. We found no evidence of exponential population growth in any dataset. In some stocks, a density dependence in the size of the initial inoculum limited the maximum rate of parasite population growth. There is no evidence to support the hypothesis that all Norwegian and Scottish Atlantic salmon stocks are equally susceptible to G. salaris, while Baltic stocks control and limit infections due to co-evolution. Northern and Western Norwegian as well as the Scottish Shin stocks, support higher initial parasite population growth rates than Baltic, South-eastern Norwegian, or the Scottish Conon stocks, and several Norwegian stocks tested (Akerselva, Altaelva, Lierelva, Numedalslågen), and the Scottish stocks (i.e. Conon, Shin), were able to limit infections after 40-50 days. No significant differences in performance of the three parasite strains (Batnfjordselva, Figga, and Lierelva), or the two parasite mitochondrial haplotypes (A and F) were observed. Our study shows a spectrum of growth rates, with some fish of the South-eastern Norwegian stocks sustaining parasite population growth rates overlapping those seen on Baltic Neva and Indalsälv stocks. This observation is inconsistent with the 'Baltic-resistant, Atlantic-susceptible' hypothesis, but suggests heterogeneity, perhaps linked to other host resistance genes driven by selection for local disease syndromes.

The Small Size Debris Population at GEO from Optical Observations

NASA Technical Reports Server (NTRS)

Seitzer, Patrick; Barker, Ed; Buckalew, Brent; Burkhardt, Andrew; Cowardin, Heather; Frith, James; Kaleida, Catherine; Lederer, Susan M.; Lee, Chris H.

2017-01-01

We have observed the geosynchronous orbit (GEO) debris population at sizes smaller than 10 cm using optical observations with the 6.5-m Magellan telescope 'Walter Baade' at the Las Campanas Observatory in Chile. The IMACS f/2 imaging camera with a 0.5-degree diameter field of view has been used in small area surveys of the GEO regime to study the population of optically faint GEO debris. The goal is to estimate the population of GEO debris that is fainter than can be studied with 1-meter class telescopes. A significant population of objects fainter than R = 19th magnitude has been found. These objects have observed with angular rates consistent with circular orbits and orbital inclinations up to 15 degrees at GEO. A sizeable number of these objects have significant brightness variations ("flashes") during the 5-second exposure, which suggest rapid changes in the albedo-projected size product.

Most common patterns of acne in male adolescents: a population-based study.

PubMed

Duquia, Rodrigo P; de Almeida, Hiram L; Breunig, Juliano A; Souzat, Paulo R M; Göellner, Caroline D

2013-05-01

Acne vulgaris is a common skin disease affecting more than 85% of adolescents and often continuing into adulthood. Population-based studies to assess the patterns and severity of acne have not been achieved. The aim of this study was to assess the most common patterns of facial and trunk acne in young (18-year-old) men in a representative sample of male adolescents in a city in southern Brazil and to investigate the severity of inflammatory and non-inflammatory lesions in these individuals. In Brazil, military service is compulsory for all males. Every adolescent male must report to his military service headquarters to submit to a medical screening examination. The study included 2201 adolescents, each of whom underwent a skin examination conducted by a dermatologist to identify and quantify all non-inflammatory (comedones) and inflammatory (papules, pustules, and nodules) lesions. Non-inflammatory lesions (comedones) were observed on 1487 individuals, and inflammatory lesions (papules and pustules) were noted on 1497 individuals. The most common patterns of facial acne were the full-face, bilateral malar and frontal mentonian distributions. This is the first population-based study to evaluate patterns of acne. Facial involvement was very prevalent, and the frontal region was found to dominate patterns of distribution of acne vulgaris. Comedonian acne of the face was much more intense and affected the entire face. In inflammatory facial acne, the majority of the study subjects exhibited up to five lesions in the region under study. © 2013 The International Society of Dermatology.

Prospects for Observing Ultracompact Binaries with Space-Based Gravitational Wave Interferometers and Optical Telescopes

NASA Technical Reports Server (NTRS)

Littenberg, T. B.; Larson, S. L.; Nelemans, G.; Cornish, N. J.

2012-01-01

Space-based gravitational wave interferometers are sensitive to the galactic population of ultracompact binaries. An important subset of the ultracompact binary population are those stars that can be individually resolved by both gravitational wave interferometers and electromagnetic telescopes. The aim of this paper is to quantify the multimessenger potential of space-based interferometers with arm-lengths between 1 and 5 Gm. The Fisher information matrix is used to estimate the number of binaries from a model of the Milky Way which are localized on the sky by the gravitational wave detector to within 1 and 10 deg(exp 2) and bright enough to be detected by a magnitude-limited survey.We find, depending on the choice ofGW detector characteristics, limiting magnitude and observing strategy, that up to several hundred gravitational wave sources could be detected in electromagnetic follow-up observations.

Filipino DNA variation at 12 X-chromosome short tandem repeat markers.

PubMed

Salvador, Jazelyn M; Apaga, Dame Loveliness T; Delfin, Frederick C; Calacal, Gayvelline C; Dennis, Sheila Estacio; De Ungria, Maria Corazon A

2018-06-08

Demands for solving complex kinship scenarios where only distant relatives are available for testing have risen in the past years. In these instances, other genetic markers such as X-chromosome short tandem repeat (X-STR) markers are employed to supplement autosomal and Y-chromosomal STR DNA typing. However, prior to use, the degree of STR polymorphism in the population requires evaluation through generation of an allele or haplotype frequency population database. This population database is also used for statistical evaluation of DNA typing results. Here, we report X-STR data from 143 unrelated Filipino male individuals who were genotyped via conventional polymerase chain reaction-capillary electrophoresis (PCR-CE) using the 12 X-STR loci included in the Investigator ® Argus X-12 kit (Qiagen) and via massively parallel sequencing (MPS) of seven X-STR loci included in the ForenSeq ™ DNA Signature Prep kit of the MiSeq ® FGx ™ Forensic Genomics System (Illumina). Allele calls between PCR-CE and MPS systems were consistent (100% concordance) across seven overlapping X-STRs. Allele and haplotype frequencies and other parameters of forensic interest were calculated based on length (PCR-CE, 12 X-STRs) and sequence (MPS, seven X-STRs) variations observed in the population. Results of our study indicate that the 12 X-STRs in the PCR-CE system are highly informative for the Filipino population. MPS of seven X-STR loci identified 73 X-STR alleles compared with 55 X-STR alleles that were identified solely by length via PCR-CE. Of the 73 sequence-based alleles observed, six alleles have not been reported in the literature. The population data presented here may serve as a reference Philippine frequency database of X-STRs for forensic casework applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Anthropometric assessment of crane cabins and recommendations for design: A case study.

PubMed

Zunjic, Aleksandar; Brkic, Vesna Spasojevic; Klarin, Milivoj; Brkic, Aleksandar; Krstic, Dragan

2015-01-01

Work of crane operators is very difficult and demanding. Therefore, it is very important that the cabin of a crane be designed on the basis of relevant anthropometric data. However, it is very difficult to find a research that considers anthropometric convenience of crane cabins. From the theoretical viewpoint, it is important to perceive and to classify effects of the anthropometric incompatibility of crane cabins. Globally, the objective is to consider the anthropometric convenience of existing crane cabins, and possibilities for improvements of their design from the ergonomic point of view. In this regard, it is significant to detect constraints that impede or hinder the work of the crane operators, which could be overcome with certain anthropometric solutions. The main objective is to examine whether and to what extent is justifiable to use anthropometric data that are obtained on the basis of general (national) population, during designing the crane cabins. For the assessment of existing crane cabins and the work of operators, four methods were used: observation of the work of the operators and design solutions of the cabins, the checklist approach, interviewing of operators and the experimental research based on obtaining the data on the population of crane operators. Results of the analysis based on the method of observation, analysis based on the application of the checklist, as well as interviewing of the operators indicate that certain construction constraints of the components in the cabins are the main reasons of reduced visibility and improper working postures of operators. All this has caused the emergence of continuous musculoskeletal loading of the crane operators. The results of the anthropometric research that were obtained on the population of crane operators in this case study suggest that there is a statistically significant difference, when compared data of this population of workers with anthropometric data from the general population. Analyzed workplaces in crane cabins do not correspond to the majority of operators from the anthropometric standpoint. The conducted anthropometric analysis has been indicated that could be made the mistake, if dimensions of the cabin and layout of equipment would be relied on data derived from the general population of citizens. In order to achieve greater precision in the design and configuration of equipment, it is recommended using the data that are obtained directly on the population of the crane operators when designing the cabin.

The dynamical origin of multiple populations in intermediate-age clusters in the Magellanic Clouds

NASA Astrophysics Data System (ADS)

Hong, Jongsuk; de Grijs, Richard; Askar, Abbas; Berczik, Peter; Li, Chengyuan; Wang, Long; Deng, Licai; Kouwenhoven, M. B. N.; Giersz, Mirek; Spurzem, Rainer

2017-11-01

Numerical simulations were carried out to study the origin of multiple stellar populations in the intermediate-age clusters NGC 411 and NGC 1806 in the Magellanic Clouds. We performed NBODY6++ simulations based on two different formation scenarios, an ad hoc formation model where second-generation (SG) stars are formed inside a cluster of first-generation (FG) stars using the gas accumulated from the external intergalactic medium and a minor merger model of unequal mass (MSG/MFG ∼ 5-10 per cent) clusters with an age difference of a few hundred million years. We compared our results such as the radial profile of the SG-to-FG number ratio with observations on the assumption that the SG stars in the observations are composed of cluster members, and confirmed that both the ad hoc formation and merger scenarios reproduce the observed radial trend of the SG-to-FG number ratio, which shows less centrally concentrated SG than FG stars. It is difficult to constrain the formation scenario for the multiple populations by only using the spatial distribution of the SG stars. SG stars originating from the merger scenario show a significant velocity anisotropy and rotational features compared to those from the ad hoc formation scenario. Thus, observations aimed at kinematic properties like velocity anisotropy or rotational velocities for SG stars should be obtained to better understand the formation of the multiple populations in these clusters. This is, however, beyond current instrumentation capabilities.

The Influence of Type 1 Diabetes Mellitus on Pulmonary Function and Exercise Capacity - Results from the Study of Health in Pomerania (SHIP).

PubMed

Stubbe, Beate; Schipf, Sabine; Schäper, Christoph; Felix, Stephan B; Steveling, Antje; Nauck, Matthias; Völzke, Henry; Wallaschofski, Henri; Friedrich, Nele; Ewert, Ralf; Ittermann, Till; Gläser, Sven

2017-01-01

Background: Diabetes mellitus Type 1 (T1DM) is associated with metabolic and microvascular diseases as part of a multi-organ and multi-systemic disorder. The dense network of capillary vessels in the lungs may change during the course of the development of microangiopathy. The connective tissue as well as alveoli may be subjected to non-enzymatic glycosylation of proteins which may in turn affect pulmonary function. Previous studies investigating lung function in patients with type 1 diabetes have only been performed on small numbers of patients. Our study is based on population data of the Study of Health in Pomerania (SHIP). Objective: To investigate the influence of metabolic control on pulmonary system function and to establish a decreased pulmonary system function as a late complication of T1DM in a population based setting. Methods: The study is a case matched study with multiple controls based on participants with T1DM (SHIP-DM-1, n=73) and non-diabetics (SHIP-1, n=292) from the population based study of Pomerania. Data on lung function and exercise performance stratified by age, sex, body mass index and smoking habits in participants with T1DM and without diabetes were matched. Results: Participants with T1DM showed a significantly lower total lung capacity, residual volume and forced vital capacity. The transfer factor for carbon monoxide, the maximum power output and oxygen uptake during exercise were significantly decreased in comparison to the general population without diabetes. Conclusion: The pattern of abnormal pulmonary function as observed in the present study with a reduction in lung volume parameters and reduced oxygen uptake in participants with T1DM suggests a restrictive type of lung disease caused by an intrinsic lung tissue derangement as well as pulmonary microangiopathy. © Georg Thieme Verlag KG Stuttgart · New York.

The TSH levels and risk of hypothyroidism: Results from a population based prospective cohort study in an Iranian adult's population.

PubMed

Aminorroaya, Ashraf; Meamar, Rokhsareh; Amini, Massoud; Feizi, Awat; Nasri, Maryam; Tabatabaei, Azamosadat; Faghihimani, Elham

2017-06-01

The aim of current study was to assess the relationship between serum TSH levels and hypothyroidism risk in the euthyroid population. In a population-based cohort study, a total of 615 individuals with a normal baseline TSH, from of total population (n=2254) in 2006, were followed up for 6years. TSH, total T4, thyroid peroxidase antibody (TPOAb), and thyroglobulin antibody (TgAb) were measured. The relative risk (RR) and 95% confidence interval (95%CI) were calculated based on logistic regression. The Receiver Operating Characteristic (ROC) analysis along with area under the curve (AUC) was used to prediction of future hypothyroidism. TSH level in 2006 was a significant predictor for overt hypothyroidism, in the total population (RR=3.5) and female (RR=1.37) (all, P value<0.05). A cutoff value of TSH at 2.05mIU/L [AUC: (CI95 %), 0.68 (0.44-0.92; P=0.05)] was obtained for differentiating the patients with overt hypothyroidism from euthyroid. However, this cut off was not observed when we included only negative TPO and TgAbs people in 2006. The RR of hypothyroidism increased gradually when TSH level increased from 2.06-3.6mIU/L to >3.6mIU/L in the total population and both sexes. In women, the risk of overt hypothyroidism was significantly higher in subjects with TSH above 3.6 than those subject with THS levels≤2.05 [RR: (CI95 %), 20.57(2.-207.04), P value<0.05]. A cutoff value of TSH at 2.05mIU/L could predict the development of overt hypothyroidism in future. However, it was not applicable for people with negative TPOAb and negative TgAb. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Optimal designs for population pharmacokinetic studies of the partner drugs co-administered with artemisinin derivatives in patients with uncomplicated falciparum malaria.

PubMed

Jamsen, Kris M; Duffull, Stephen B; Tarning, Joel; Lindegardh, Niklas; White, Nicholas J; Simpson, Julie A

2012-07-11

Artemisinin-based combination therapy (ACT) is currently recommended as first-line treatment for uncomplicated malaria, but of concern, it has been observed that the effectiveness of the main artemisinin derivative, artesunate, has been diminished due to parasite resistance. This reduction in effect highlights the importance of the partner drugs in ACT and provides motivation to gain more knowledge of their pharmacokinetic (PK) properties via population PK studies. Optimal design methodology has been developed for population PK studies, which analytically determines a sampling schedule that is clinically feasible and yields precise estimation of model parameters. In this work, optimal design methodology was used to determine sampling designs for typical future population PK studies of the partner drugs (mefloquine, lumefantrine, piperaquine and amodiaquine) co-administered with artemisinin derivatives. The optimal designs were determined using freely available software and were based on structural PK models from the literature and the key specifications of 100 patients with five samples per patient, with one sample taken on the seventh day of treatment. The derived optimal designs were then evaluated via a simulation-estimation procedure. For all partner drugs, designs consisting of two sampling schedules (50 patients per schedule) with five samples per patient resulted in acceptable precision of the model parameter estimates. The sampling schedules proposed in this paper should be considered in future population pharmacokinetic studies where intensive sampling over many days or weeks of follow-up is not possible due to either ethical, logistic or economical reasons.

Sex ratios of fledgling and recaptured subadult spotted owls in the southern Sierra Nevada

Treesearch

George N. Steger

1995-01-01

Estimates of instantaneous growth rates (A) of spotted owl (Strix occidentalis) populations have been based on demographic data that uniformly assumed an equal sex ratio among fledglings. In this study, sex ratios of subadults, banded as juveniles, and fledgling California spotted owls (S. o. occidentalis) were observed and compared to an assumed 1 : 1 ratio. The...

Validation of cross-sectional time series and multivariate adaptive regression splines models for the prediction of energy expenditure in children and adolescents using doubly labeled water

USDA-ARS?s Scientific Manuscript database

Accurate, nonintrusive, and inexpensive techniques are needed to measure energy expenditure (EE) in free-living populations. Our primary aim in this study was to validate cross-sectional time series (CSTS) and multivariate adaptive regression splines (MARS) models based on observable participant cha...

Chain pooling to minimize prediction error in subset regression. [Monte Carlo studies using population models

NASA Technical Reports Server (NTRS)

Holms, A. G.

1974-01-01

Monte Carlo studies using population models intended to represent response surface applications are reported. Simulated experiments were generated by adding pseudo random normally distributed errors to population values to generate observations. Model equations were fitted to the observations and the decision procedure was used to delete terms. Comparison of values predicted by the reduced models with the true population values enabled the identification of deletion strategies that are approximately optimal for minimizing prediction errors.

Current issues and future perspectives of gastric cancer screening

PubMed Central

Hamashima, Chisato

2014-01-01

Gastric cancer remains the second leading cause of cancer death worldwide. About half of the incidence of gastric cancer is observed in East Asian countries, which show a higher mortality than other countries. The effectiveness of 3 new gastric cancer screening techniques, namely, upper gastrointestinal endoscopy, serological testing, and “screen and treat” method were extensively reviewed. Moreover, the phases of development for cancer screening were analyzed on the basis of the biomarker development road map. Several observational studies have reported the effectiveness of endoscopic screening in reducing mortality from gastric cancer. On the other hand, serologic testing has mainly been used for targeting the high-risk group for gastric cancer. To date, the effectiveness of new techniques for gastric cancer screening has remained limited. However, endoscopic screening is presently in the last trial phase of development before their introduction to population-based screening. To effectively introduce new techniques for gastric cancer screening in a community, incidence and mortality reduction from gastric cancer must be initially and thoroughly evaluated by conducting reliable studies. In addition to effectiveness evaluation, the balance of benefits and harms must be carefully assessed before introducing these new techniques for population-based screening. PMID:25320514

C-reactive protein levels and treatment resistance in schizophrenia-A Danish population-based cohort study.

PubMed

Horsdal, Henriette Thisted; Wimberley, Theresa; Benros, Michael Eriksen; Gasse, Christiane

2017-11-01

Schizophrenia is associated with increased levels of inflammatory markers. However, it remains unclear whether inflammatory markers are associated with treatment-resistant schizophrenia. We conducted a population-based follow-up study among individuals with a first-time schizophrenia diagnosis and a baseline C-reactive protein measurement (a commonly available marker of systemic inflammation) from 2000 to 2012. We defined treatment resistance as the earliest observed instance of either clozapine initiation or hospital admission due to schizophrenia after having received at least 2 prior antipsychotic monotherapy trials of adequate duration. We used adjusted Cox regression analysis to calculate hazard ratios. We identified 390 individuals with a C-reactive protein measurement at first-time schizophrenia diagnosis. A nonsignificant higher median C-reactive protein (4.0 vs. 3.1 mg/L, p = .13) was observed among the 52 (13.3%) treatment-resistant individuals. Increased levels of C-reactive protein (above 3 mg/L) at baseline were not associated with treatment resistance (adjusted hazard ratio = 0.99, 95% confidence interval [0.56, 1.73]). C-reactive protein, as a single inflammatory marker, appears insufficient to detect treatment-resistant schizophrenia. Copyright © 2017 John Wiley & Sons, Ltd.

Duration of breast feeding and arterial distensibility in early adult life: population based study.

PubMed

Leeson, C P; Kattenhorn, M; Deanfield, J E; Lucas, A

2001-03-17

To test the hypothesis that duration of breast feeding is related to changes in vascular function relevant to the development of cardiovascular disease. Population based observational study. Cambridge. 331 adults (171 women, 160 men) aged between 20 and 28 years, born in Cambridge Maternity Hospital. Distensibility of brachial artery, type and duration of infant feeding, current lipid profile, and other cardiovascular risk factors. The longer the period of breast feeding the less distensible the artery wall in early adult life, with no sex differences (regression coefficient = -3.93 micrometer/month, 95% confidence interval -7.29 to -0.57, P=0.02). However, in those breast fed for less than four months, arterial distensibility was not significantly reduced compared with an exclusively formula fed group. The vascular changes observed were not explained by alterations in plasma cholesterol concentration in adult life. Breast feeding in infancy is related to reduced arterial function 20 years later. These data should not alter current recommendations in favour of breast feeding, which has several benefits for infant health. Further work is needed, however, to explore the optimal duration of breast feeding in relation to cardiovascular outcomes.

Size and age structure of anadromous and landlocked populations of Rainbow Smelt

USGS Publications Warehouse

O'Malley, Andrew; Enterline, Claire; Zydlewski, Joseph D.

2017-01-01

Rainbow Smelt Osmerus mordax are widely distributed in both anadromous and landlocked populations throughout northeastern North America; abundance, size at age, and maximum size vary widely among populations and life histories. In the present study, size at age, von Bertalanffy growth parameters, population age distributions, and precision and bias in age assessment based on scales and sectioned otoliths were compared between ecotypes and among populations of Rainbow Smelt. To compare the ecotypes, we collected spawning adults from four anadromous and three landlocked populations in Maine during spring 2014. A significant bias was identified in only one of four scale comparisons but in four of seven otolith comparisons; however, a comparable level of precision was indicated. Anadromous populations had larger and more variable size at age and von Bertalanffy growth parameters than landlocked fish. Populations were composed of ages 1–4; six populations were dominated by age-2 or age-3 individuals, and one population was dominated by age-1 fish. These data suggest the presence of considerable plasticity among populations. A latitudinal gradient was observed in the anadromous Rainbow Smelt, which may show signs of population stress at the southern extent of their distribution.

Characterising private and shared signatures of positive selection in 37 Asian populations.

PubMed

Liu, Xuanyao; Lu, Dongsheng; Saw, Woei-Yuh; Shaw, Philip J; Wangkumhang, Pongsakorn; Ngamphiw, Chumpol; Fucharoen, Suthat; Lert-Itthiporn, Worachart; Chin-Inmanu, Kwanrutai; Chau, Tran Nguyen Bich; Anders, Katie; Kasturiratne, Anuradhani; de Silva, H Janaka; Katsuya, Tomohiro; Kimura, Ryosuke; Nabika, Toru; Ohkubo, Takayoshi; Tabara, Yasuharu; Takeuchi, Fumihiko; Yamamoto, Ken; Yokota, Mitsuhiro; Mamatyusupu, Dolikun; Yang, Wenjun; Chung, Yeun-Jun; Jin, Li; Hoh, Boon-Peng; Wickremasinghe, Ananda R; Ong, RickTwee-Hee; Khor, Chiea-Chuen; Dunstan, Sarah J; Simmons, Cameron; Tongsima, Sissades; Suriyaphol, Prapat; Kato, Norihiro; Xu, Shuhua; Teo, Yik-Ying

2017-04-01

The Asian Diversity Project (ADP) assembled 37 cosmopolitan and ethnic minority populations in Asia that have been densely genotyped across over half a million markers to study patterns of genetic diversity and positive natural selection. We performed population structure analyses of the ADP populations and divided these populations into four major groups based on their genographic information. By applying a highly sensitive algorithm haploPS to locate genomic signatures of positive selection, 140 distinct genomic regions exhibiting evidence of positive selection in at least one population were identified. We examined the extent of signal sharing for regions that were selected in multiple populations and observed that populations clustered in a similar fashion to that of how the ancestry clades were phylogenetically defined. In particular, populations predominantly located in South Asia underwent considerably different adaptation as compared with populations from the other geographical regions. Signatures of positive selection present in multiple geographical regions were predicted to be older and have emerged prior to the separation of the populations in the different regions. In contrast, selection signals present in a single population group tended to be of lower frequencies and thus can be attributed to recent evolutionary events.

Characterising private and shared signatures of positive selection in 37 Asian populations

PubMed Central

Liu, Xuanyao; Lu, Dongsheng; Saw, Woei-Yuh; Shaw, Philip J; Wangkumhang, Pongsakorn; Ngamphiw, Chumpol; Fucharoen, Suthat; Lert-itthiporn, Worachart; Chin-inmanu, Kwanrutai; Chau, Tran Nguyen Bich; Anders, Katie; Kasturiratne, Anuradhani; de Silva, H Janaka; Katsuya, Tomohiro; Kimura, Ryosuke; Nabika, Toru; Ohkubo, Takayoshi; Tabara, Yasuharu; Takeuchi, Fumihiko; Yamamoto, Ken; Yokota, Mitsuhiro; Mamatyusupu, Dolikun; Yang, Wenjun; Chung, Yeun-Jun; Jin, Li; Hoh, Boon-Peng; Wickremasinghe, Ananda R; Ong, RickTwee-Hee; Khor, Chiea-Chuen; Dunstan, Sarah J; Simmons, Cameron; Tongsima, Sissades; Suriyaphol, Prapat; Kato, Norihiro; Xu, Shuhua; Teo, Yik-Ying

2017-01-01

The Asian Diversity Project (ADP) assembled 37 cosmopolitan and ethnic minority populations in Asia that have been densely genotyped across over half a million markers to study patterns of genetic diversity and positive natural selection. We performed population structure analyses of the ADP populations and divided these populations into four major groups based on their genographic information. By applying a highly sensitive algorithm haploPS to locate genomic signatures of positive selection, 140 distinct genomic regions exhibiting evidence of positive selection in at least one population were identified. We examined the extent of signal sharing for regions that were selected in multiple populations and observed that populations clustered in a similar fashion to that of how the ancestry clades were phylogenetically defined. In particular, populations predominantly located in South Asia underwent considerably different adaptation as compared with populations from the other geographical regions. Signatures of positive selection present in multiple geographical regions were predicted to be older and have emerged prior to the separation of the populations in the different regions. In contrast, selection signals present in a single population group tended to be of lower frequencies and thus can be attributed to recent evolutionary events. PMID:28098149

Suicidal drug overdose in patients with systemic lupus erythematosus, a nationwide population-based case-control study.

PubMed

Tang, K T; Lin, C H; Chen, H H; Chen, Y H; Chen, D Y

2016-02-01

A four-fold increase of suicide mortality has been demonstrated in systemic lupus erythematosus (SLE) patients. Prior studies showed that the most common method of suicide attempts in SLE patients involves drug overdose. Therefore, we conducted a nationwide population-based case-control study to elucidate factors associated with drug overdose as suicide attempt in SLE patients. This study was based on the National Health Insurance Research Database in Taiwan. We identified all SLE patients from January 1, 2000 to December 31, 2010. Patients who had suicidal drug overdose (SDO) were selected as cases while age- and gender-matched patients who did not have SDO were selected as controls. The incidence rate of SDO in SLE patients was 291 cases per 100,000 person-years, higher than that in the general population (160 cases per 100,000 person-years). In a multivariate logistic regression analysis, we observed that SDO was associated with psychiatric disorders such as depressive disorders (odds ratio: 8.36, 95% confidence interval (CI): 5.60-12.48) and insomnia (odds ratio: 2.71, 95% CI: 1.73-4.25), and lower monthly income (odds ratios: 2.74 to 3.50) in SLE patients. SDO is associated with psychiatric disorders such as depressive disorders and insomnia, and lower monthly income in SLE patients. © The Author(s) 2015.

Young adults' trajectories of Ecstasy use: a population based study.

PubMed

Smirnov, Andrew; Najman, Jake M; Hayatbakhsh, Reza; Plotnikova, Maria; Wells, Helene; Legosz, Margot; Kemp, Robert

2013-11-01

Young adults' Ecstasy use trajectories have important implications for individual and population-level consequences of Ecstasy use, but little relevant research has been conducted. This study prospectively examines Ecstasy trajectories in a population-based sample. Data are from the Natural History Study of Drug Use, a retrospective/prospective cohort study conducted in Australia. Population screening identified a probability sample of Ecstasy users aged 19-23 years. Complete data for 30 months of follow-up, comprising 4 time intervals, were available for 297 participants (88.4% of sample). Trajectories were derived using cluster analysis based on recent Ecstasy use at each interval. Trajectory predictors were examined using a generalized ordered logit model and included Ecstasy dependence (World Mental Health Composite International Diagnostic Instrument), psychological distress (Hospital Anxiety Depression Scale), aggression (Young Adult Self Report) and contextual factors (e.g. attendance at electronic/dance music events). Three Ecstasy trajectories were identified (low, intermediate and high use). At its peak, the high-use trajectory involved 1-2 days Ecstasy use per week. Decreasing frequency of use was observed for intermediate and high-use trajectories from 12 months, independently of market factors. Intermediate and high-use trajectory membership was predicted by past Ecstasy consumption (>70 pills) and attendance at electronic/dance music events. High-use trajectory members were unlikely to have used Ecstasy for more than 3 years and tended to report consistently positive subjective effects at baseline. Given the social context and temporal course of Ecstasy use, Ecstasy trajectories might be better understood in terms of instrumental rather than addictive drug use patterns. © 2013 Elsevier Ltd. All rights reserved.

Polyunsaturated fatty acid interactions and breast cancer incidence: a population-based case-control study on Long Island, New York.

PubMed

Khankari, Nikhil K; Bradshaw, Patrick T; Steck, Susan E; He, Ka; Olshan, Andrew F; Shen, Jing; Ahn, Jiyoung; Chen, Yu; Ahsan, Habibul; Terry, Mary Beth; Teitelbaum, Susan L; Neugut, Alfred I; Santella, Regina M; Gammon, Marilie D

2015-12-01

Experimental studies demonstrate that ω-3 polyunsaturated fatty acids (PUFAs) inhibit inflammatory eicosanoids generated by ω-6 PUFAs. Epidemiologic studies on dietary ω-3 PUFA intake show consistent inverse associations with breast cancer incidence among Asian populations, where ω-3, relative to ω-6, intake is high. In contrast, associations are inconsistent among Western populations, where intake of ω-3, relative to ω-6, is low. We hypothesized that examining interactions between ω-3 and ω-6 would help elucidate the PUFA-breast cancer association in the United States. In a Long Island, New York, population-based study of 1463 breast cancer cases and 1500 controls, we estimated multivariable-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression to examine interactions between ω-3 and ω-6 intake. We observed a super-additive interaction (relative excess risk due to interaction = 0.41; 95% confidence interval = 0.06-0.76) between ω-3 and ω-6 intake in association with breast cancer incidence, although the CIs for the joint exposure of low ω-3/high ω-6 compared to high ω-3/low ω-6 intake were wide (odds ratio = 1.20; 95% confidence interval = 0.85-1.69). Breast cancer risk reduction may be possible for U.S. women with dietary consumption of higher ω-3, which has anti-inflammatory properties, in concert with lower ω-6, which induces inflammation. Replication from future U.S.-based investigations is needed. Copyright © 2015 Elsevier Inc. All rights reserved.

Craters and ejecta on Pluto and Charon: Anticipated results from the New Horizons flyby

NASA Astrophysics Data System (ADS)

Bierhaus, Edward B.; Dones, Luke

2015-01-01

We examine the flux of bodies striking Pluto and Charon, and the nature of the crater populations that will form as a result of these impacts. Assuming impact speeds of 2 km/s and an impact angle of 45 ° , a 1 km impactor will form a 4.2 km diameter transient crater on Pluto, and a ∼5.0 km crater on Charon, as compared with 8-13 km for several mid-sized saturnian satellites and 8-10 km for the icy Galilean satellites. We predict that secondary craters will be present in the crater size-frequency distribution (SFD) for Pluto and Charon at sizes less than a few km, at spatial densities comparable to the range seen on the mid-sized saturnian satellites and distinctly less than seen on the icy Galilean satellites. Pluto should have more secondary craters formed per primary impact than Charon, so if neither crater population on these bodies is in saturation, Charon's crater SFD should be the "cleanest" reflection of the primary, impacting SFD. Ejecta from Pluto and Charon escape more efficiently from the combined system, relative to ejecta from a satellite in orbit around a giant planet, due to the absence of a large central body. We estimate that Kuiper Belt Objects (KBOs) with diameters larger than 1 km should strike Pluto and Charon on (nominal) timescales of 2.2 and 10 million years, respectively. These estimates are uncertain because the numbers of small KBOs are poorly constrained. Our estimated rates are smaller than earlier predictions of impact rates, primarily because we assume a KBO size distribution that is shallower overall than previous studies did. The impact rate, combined with the observed crater SFD, will enable estimates of relative and absolute age of different geologic units, should different geologic units exist. We explore two scenarios in regards to the crater population: (1) a shallow (differential power-law index of p ∼ 2 , i.e. for dN / dD ∝D-p), based on the crater SFD observed on young terrains of Galilean and saturnian satellites; and (2) a slightly steeper SFD (p ∼ 3), based on extrapolations of larger (∼100 km) KBOs from ground-based surveys. If the observed primary crater SFD, at diameters less than a few tens of km, is consistent with a differential power-law index p ∼ 2 , that will confirm that KBOs are deficient in small bodies relative to extrapolations from known ∼100 km KBOs, consistent with expectations derived from examination of crater populations in young terrains on the Galilean and saturnian satellites. If the crater SFD has p ⩾ 3 over all observed sizes, then that power-law index applies across the KBO population over at least two orders of magnitude (1 km to100 km objects), and there must be some process that erodes the small KBOs when they migrate to the Jupiter-Saturn region of the Solar System. Whatever SFD is observed, the primary crater population on Pluto and Charon will provide the strongest constraint on the SFD of small KBOs, which will be beyond the observational reach of ground- and space-based telescopes for years to come. This, in turn, will provide a fundamental constraint for further understanding of the evolution of this distant and compelling population of bodies beyond Neptune.

Demographic collapse and low genetic diversity of the Irrawaddy dolphin population inhabiting the Mekong River

PubMed Central

Beasley, Isabel; Ackermann, Corinne Y.; Lieckfeldt, Dietmar; Ludwig, Arne; Ryan, Gerard E.; Bejder, Lars; Parra, Guido J.; Wolfensberger, Rebekka; Spencer, Peter B. S.

2018-01-01

In threatened wildlife populations, it is important to determine whether observed low genetic diversity may be due to recent anthropogenic pressure or the consequence of historic events. Historical size of the Irrawaddy dolphin (Orcaella brevirostris) population inhabiting the Mekong River is unknown and there is significant concern for long-term survival of the remaining population as a result of low abundance, slow reproduction rate, high neonatal mortality, and continuing anthropogenic threats. We investigated population structure and reconstructed the demographic history based on 60 Irrawaddy dolphins samples collected between 2001 and 2009. The phylogenetic analysis indicated reciprocal monophyly of Mekong River Orcaella haplotypes with respect to haplotypes from other populations, suggesting long-standing isolation of the Mekong dolphin population from other Orcaella populations. We found that at least 85% of all individuals in the two main study areas: Kratie and Stung Treng, bore the same mitochondrial haplotype. Out of the 21 microsatellite loci tested, only ten were polymorphic and exhibited very low levels of genetic diversity. Both individual and frequency-based approaches suggest very low and non-significant genetic differentiation of the Mekong dolphin population. Evidence for recent bottlenecks was equivocal. Some results suggested a recent exponential decline in the Mekong dolphin population, with the current size being only 5.2% of the ancestral population. In order for the Mekong dolphin population to have any potential for long-term survival, it is imperative that management priorities focus on preventing any further population fragmentation or genetic loss, reducing or eliminating anthropogenic threats, and promoting connectivity between all subpopulations. PMID:29298312

Assessing the Generalizability of Randomized Trial Results to Target Populations

PubMed Central

Stuart, Elizabeth A.; Bradshaw, Catherine P.; Leaf, Philip J.

2014-01-01

Recent years have seen increasing interest in and attention to evidence-based practices, where the “evidence” generally comes from well-conducted randomized trials. However, while those trials yield accurate estimates of the effect of the intervention for the participants in the trial (known as “internal validity”), they do not always yield relevant information about the effects in a particular target population (known as “external validity”). This may be due to a lack of specification of a target population when designing the trial, difficulties recruiting a sample that is representative of a pre-specified target population, or to interest in considering a target population somewhat different from the population directly targeted by the trial. This paper first provides an overview of existing design and analysis methods for assessing and enhancing the ability of a randomized trial to estimate treatment effects in a target population. It then provides a case study using one particular method, which weights the subjects in a randomized trial to match the population on a set of observed characteristics. The case study uses data from a randomized trial of School-wide Positive Behavioral Interventions and Supports (PBIS); our interest is in generalizing the results to the state of Maryland. In the case of PBIS, after weighting, estimated effects in the target population were similar to those observed in the randomized trial. The paper illustrates that statistical methods can be used to assess and enhance the external validity of randomized trials, making the results more applicable to policy and clinical questions. However, there are also many open research questions; future research should focus on questions of treatment effect heterogeneity and further developing these methods for enhancing external validity. Researchers should think carefully about the external validity of randomized trials and be cautious about extrapolating results to specific populations unless they are confident of the similarity between the trial sample and that target population. PMID:25307417

Assessing the generalizability of randomized trial results to target populations.

PubMed

Stuart, Elizabeth A; Bradshaw, Catherine P; Leaf, Philip J

2015-04-01

Recent years have seen increasing interest in and attention to evidence-based practices, where the "evidence" generally comes from well-conducted randomized trials. However, while those trials yield accurate estimates of the effect of the intervention for the participants in the trial (known as "internal validity"), they do not always yield relevant information about the effects in a particular target population (known as "external validity"). This may be due to a lack of specification of a target population when designing the trial, difficulties recruiting a sample that is representative of a prespecified target population, or to interest in considering a target population somewhat different from the population directly targeted by the trial. This paper first provides an overview of existing design and analysis methods for assessing and enhancing the ability of a randomized trial to estimate treatment effects in a target population. It then provides a case study using one particular method, which weights the subjects in a randomized trial to match the population on a set of observed characteristics. The case study uses data from a randomized trial of school-wide positive behavioral interventions and supports (PBIS); our interest is in generalizing the results to the state of Maryland. In the case of PBIS, after weighting, estimated effects in the target population were similar to those observed in the randomized trial. The paper illustrates that statistical methods can be used to assess and enhance the external validity of randomized trials, making the results more applicable to policy and clinical questions. However, there are also many open research questions; future research should focus on questions of treatment effect heterogeneity and further developing these methods for enhancing external validity. Researchers should think carefully about the external validity of randomized trials and be cautious about extrapolating results to specific populations unless they are confident of the similarity between the trial sample and that target population.

Genetic diversity in populations of Isatis glauca Aucher ex Boiss. ssp. from Central Anatolia in Turkey, as revealed by AFLP analysis.

PubMed

Özbek, Özlem; Görgülü, Elçin; Yıldırımlı, Şinasi

2013-12-01

Isatidae L. is a complex and systematically difficult genus in Brassicaceae. The genus displays great morphological polymorphism, which makes the classification of species and subspecies difficult as it is observed in Isatis glauca Aucher ex Boiss. The aim of this study is characterization of the genetic diversity in subspecies of Isatis glauca Aucher ex Boiss. distributed widely in Central Anatolia, in Turkey by using Amplified Fragment Length Polymorphism (AFLP) technique. Eight different Eco RI-Mse I primer combinations produced 805 AFLP loci, 793 (98.5%) of which were polymorphic in 67 accessions representing nine different populations. The data obtained by AFLP was computed with using GDA (Genetic Data Analysis) and STRUCTURE (version 2.3.3) software programs for population genetics. The mean proportion of the polymorphic locus (P), the mean number of alleles (A), the number of unique alleles (U) and the mean value of gene diversity (He) were 0.59, 1.59, 20, and 0.23 respectively. The coancestry coefficient (ϴ) was 0.24. The optimal number of K was identified as seven. The principal component analysis (PCA) explained 85.61% of the total genetic variation. Isatis glauca ssp. populations showed a high level of genetic diversity, and the AFLP analysis revealed that high polymorphism and differentiated subspecies could be used conveniently for population genetic studies. The principal coordinate analysis (PCoA) based on the dissimilarity matrix, the dendrogram drawn with UPGMA method and STRUCTURE cluster analysis distinguished the accessions successfully. The accessions formed distinctive population structures for populations AA, AB, E, K, and S. Populations AG1 and AG2 seemed to have similar genetic content, in addition, in both populations several hybrid individuals were observed. The accessions did not formed distinctive population structures for both populations AI and ANP. Consequently, Ankara province might be the area, where species Isatis glauca Aucher ex Boiss. originated.

TP53 codon 72 polymorphism and susceptibility to cervical cancer in the Chinese population: an update meta-analysis

PubMed Central

Li, Bing; Wang, Xin; Chen, Hong; Shang, Li-Xin; Wu, Nan

2015-01-01

Background: Although many epidemiologic studies investigated the TP53 codon 72 polymorphism and its association with cervical cancer (CC), definite conclusions cannot be drawn. Aim of the study: To evaluate the association between TP53 codon 72 polymorphism and risk of cervical cancer in the Chinese population. Methods: A computerized literature search was carried out in PubMed, Springer Link, Ovid, Chinese Biomedical Database (CBM), Chinese National Knowledge Infrastructure (CNKI), and Chinese Wanfang Database to collect relevant articles. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to calculate the strength of association. Results: A total of 16 studies including 1684 CC cases and 1178 controls were involved in this meta-analysis. Overall, significant increased association was found between the Pro/Pro carriers and CC risk when all studies in Chinese population pooled into the meta-analysis (heterozygous model: OR = 1.22, 95% CI: 1.01-1.46). In subgroup analyses stratified by ethnicity and source of controls, the same results were observed in Han and in hospital-based studies. Conclusion: Our results suggest that the TP53 codon 72 polymorphism may be potential biomarkers for CC risk in the Chinese population, especially for Han Chinese, and studies with wider spectrum of population are required for definite conclusions. PMID:26309559

Differential Item Functioning in the SF-36 Physical Functioning and Mental Health Sub-Scales: A Population-Based Investigation in the Canadian Multicentre Osteoporosis Study.

PubMed

Lix, Lisa M; Wu, Xiuyun; Hopman, Wilma; Mayo, Nancy; Sajobi, Tolulope T; Liu, Juxin; Prior, Jerilynn C; Papaioannou, Alexandra; Josse, Robert G; Towheed, Tanveer E; Davison, K Shawn; Sawatzky, Richard

2016-01-01

Self-reported health status measures, like the Short Form 36-item Health Survey (SF-36), can provide rich information about the overall health of a population and its components, such as physical, mental, and social health. However, differential item functioning (DIF), which arises when population sub-groups with the same underlying (i.e., latent) level of health have different measured item response probabilities, may compromise the comparability of these measures. The purpose of this study was to test for DIF on the SF-36 physical functioning (PF) and mental health (MH) sub-scale items in a Canadian population-based sample. Study data were from the prospective Canadian Multicentre Osteoporosis Study (CaMos), which collected baseline data in 1996-1997. DIF was tested using a multiple indicators multiple causes (MIMIC) method. Confirmatory factor analysis defined the latent variable measurement model for the item responses and latent variable regression with demographic and health status covariates (i.e., sex, age group, body weight, self-perceived general health) produced estimates of the magnitude of DIF effects. The CaMos cohort consisted of 9423 respondents; 69.4% were female and 51.7% were less than 65 years. Eight of 10 items on the PF sub-scale and four of five items on the MH sub-scale exhibited DIF. Large DIF effects were observed on PF sub-scale items about vigorous and moderate activities, lifting and carrying groceries, walking one block, and bathing or dressing. On the MH sub-scale items, all DIF effects were small or moderate in size. SF-36 PF and MH sub-scale scores were not comparable across population sub-groups defined by demographic and health status variables due to the effects of DIF, although the magnitude of this bias was not large for most items. We recommend testing and adjusting for DIF to ensure comparability of the SF-36 in population-based investigations.

Discovery of Extended Main-sequence Turnoffs in Four Young Massive Clusters in the Magellanic Clouds

NASA Astrophysics Data System (ADS)

Li, Chengyuan; de Grijs, Richard; Deng, Licai; Milone, Antonino P.

2017-08-01

An increasing number of young massive clusters (YMCs) in the Magellanic Clouds have been found to exhibit bimodal or extended main sequences (MSs) in their color-magnitude diagrams (CMDs). These features are usually interpreted in terms of a coeval stellar population with different stellar rotational rates, where the blue and red MS stars are populated by non- (or slowly) and rapidly rotating stellar populations, respectively. However, some studies have shown that an age spread of several million years is required to reproduce the observed wide turnoff regions in some YMCs. Here we present the ultraviolet-visual CMDs of four Large and Small Magellanic Cloud YMCs, NGC 330, NGC 1805, NGC 1818, and NGC 2164, based on high-precision Hubble Space Telescope photometry. We show that they all exhibit extended main-sequence turnoffs (MSTOs). The importance of age spreads and stellar rotation in reproducing the observations is investigated. The observed extended MSTOs cannot be explained by stellar rotation alone. Adopting an age spread of 35-50 Myr can alleviate this difficulty. We conclude that stars in these clusters are characterized by ranges in both their ages and rotation properties, but the origin of the age spread in these clusters remains unknown.

A new mechanism for relativistic particle acceleration via wave-particle interaction

NASA Astrophysics Data System (ADS)

Lapenta, Giovanni; Markidis, Stefano; Marocchino, Alberto

2006-10-01

Often in laboratory, space and astrophysical plasma, high energy populations are observed. Two puzzling factors still defy our understanding. First, such populations of high energy particles produce power law distributions that are not only ubiquitous but also persistent in time. Such persistence is in direct contradiction to the H theorem that states the ineluctable transition of physical systems towards thermodynamic equilibrium, and ergo Maxwellian distributions. Second, such high energy populations are efficiently produced, much more efficiently than processes that we know can produce. A classic example of such a situation is cosmic rays where power alws extend up to tremendolus energy ranges. In the present work, we identify a new mechanism for particle acceleration via wave-particle interaction. The mechanism is peculiar to special relativity and has no classical equivalent. That explains why it is not observed in most simulation studies of plasma processes, based on classical physics. The mechanism is likely to be active in systems undergoing streaming instabilities and in particular shocked systems. The new mechanism can produce energy increases vastly superior to previously known mechanisms (such as Fermi acceleration) and can hold the promise of explaining at least some of the observed power laws.

Environmental, psychological, and social influences on physical activity among Japanese adults: structural equation modeling analysis.

PubMed

Ishii, Kaori; Shibata, Ai; Oka, Koichiro

2010-08-05

An understanding of the contributing factors to be considered when examining how individuals engage in physical activity is important for promoting population-based physical activity. The environment influences long-term effects on population-based health behaviors. Personal variables, such as self-efficacy and social support, can act as mediators of the predictive relationship between the environment and physical activity. The present study examines the direct and indirect effects of environmental, psychological, and social factors on walking, moderate-intensity activity excluding walking, and vigorous-intensity activity among Japanese adults. The participants included 1,928 Japanese adults aged 20-79 years. Seven sociodemographic attributes (e.g., gender, age, education level, employment status), psychological variables (self-efficacy, pros, and cons), social variables (social support), environmental variables (home fitness equipment, access to facilities, neighborhood safety, aesthetic sensibilities, and frequency of observing others exercising), and the International Physical Activity Questionnaire were assessed via an Internet-based survey. Structural equation modeling was conducted to determine associations between environmental, psychological, and social factors with physical activity. Environmental factors could be seen to have indirect effects on physical activity through their influence on psychological and social variables such as self-efficacy, pros and cons, and social support. The strongest indirect effects could be observed by examining the consequences of environmental factors on physical activity through cons to self-efficacy. The total effects of environmental factors on physical activity were 0.02 on walking, 0.02 on moderate-intensity activity excluding walking, and 0.05 on vigorous-intensity activity. The present study indicates that environmental factors had indirect effects on walking, moderate-intensity activity excluding walking and vigorous-intensity activity among Japanese adults, especially through the effects on these factors of self-efficacy, social support, and pros and cons. The findings of the present study imply that intervention strategies to promote more engagement in physical activity for population-based health promotion may be necessary.

Environmental, psychological, and social influences on physical activity among Japanese adults: structural equation modeling analysis

PubMed Central

2010-01-01

Background An understanding of the contributing factors to be considered when examining how individuals engage in physical activity is important for promoting population-based physical activity. The environment influences long-term effects on population-based health behaviors. Personal variables, such as self-efficacy and social support, can act as mediators of the predictive relationship between the environment and physical activity. The present study examines the direct and indirect effects of environmental, psychological, and social factors on walking, moderate-intensity activity excluding walking, and vigorous-intensity activity among Japanese adults. Methods The participants included 1,928 Japanese adults aged 20-79 years. Seven sociodemographic attributes (e.g., gender, age, education level, employment status), psychological variables (self-efficacy, pros, and cons), social variables (social support), environmental variables (home fitness equipment, access to facilities, neighborhood safety, aesthetic sensibilities, and frequency of observing others exercising), and the International Physical Activity Questionnaire were assessed via an Internet-based survey. Structural equation modeling was conducted to determine associations between environmental, psychological, and social factors with physical activity. Results Environmental factors could be seen to have indirect effects on physical activity through their influence on psychological and social variables such as self-efficacy, pros and cons, and social support. The strongest indirect effects could be observed by examining the consequences of environmental factors on physical activity through cons to self-efficacy. The total effects of environmental factors on physical activity were 0.02 on walking, 0.02 on moderate-intensity activity excluding walking, and 0.05 on vigorous-intensity activity. Conclusions The present study indicates that environmental factors had indirect effects on walking, moderate-intensity activity excluding walking and vigorous-intensity activity among Japanese adults, especially through the effects on these factors of self-efficacy, social support, and pros and cons. The findings of the present study imply that intervention strategies to promote more engagement in physical activity for population-based health promotion may be necessary. PMID:20684794

Virtual colleagues, virtually colleagues--physicians' use of Twitter: a population-based observational study.

PubMed

Brynolf, Anne; Johansson, Stefan; Appelgren, Ester; Lynoe, Niels; Edstedt Bonamy, Anna-Karin

2013-01-01

To investigate potential violations of patient confidentiality or other breaches of medical ethics committed by physicians and medical students active on the social networking site Twitter. Population-based cross-sectional observational study. The social networking site Twitter (Swedish-speaking users, n=298819). Physicians and medical students (Swedish-speaking users, n=237) active on the social networking site Twitter between July 2007 and March 2012. Postings that reflect unprofessional behaviour and ethical breaches among physicians and medical students. In all, 237 Twitter accounts were established as held by physicians and medical students and a total of 13 780 tweets were analysed by content. In all, 276 (1.9%) tweets were labelled as 'unprofessional'. Among these, 26 (0.2%) tweets written by 15 (6.3%) physicians and medical students included information that could violate patient privacy. No information on the personal ID number or names was disclosed, but parts of the patient documentation or otherwise specific indicatory information on patients were found. Unprofessional tweets were more common among users writing under a pseudonym and among medical students. In this study of physicians and medical students on Twitter, we observed potential violations of patient privacy and other breaches of medical ethics. Our findings underline that every physician and medical student has to consider his or her presence on social networking sites. It remains to be investigated if the introduction of social networking site guidelines for medical professionals will improve awareness.

A comparison of pedigree- and DNA-based measures for identifying inbreeding depression in the critically endangered Attwater's Prairie-chicken.

PubMed

Hammerly, Susan C; Morrow, Michael E; Johnson, Jeff A

2013-11-01

The primary goal of captive breeding programmes for endangered species is to prevent extinction, a component of which includes the preservation of genetic diversity and avoidance of inbreeding. This is typically accomplished by minimizing mean kinship in the population, thereby maintaining equal representation of the genetic founders used to initiate the captive population. If errors in the pedigree do exist, such an approach becomes less effective for minimizing inbreeding depression. In this study, both pedigree- and DNA-based methods were used to assess whether inbreeding depression existed in the captive population of the critically endangered Attwater's Prairie-chicken (Tympanuchus cupido attwateri), a subspecies of prairie grouse that has experienced a significant decline in abundance and concurrent reduction in neutral genetic diversity. When examining the captive population for signs of inbreeding, variation in pedigree-based inbreeding coefficients (f(pedigree)) was less than that obtained from DNA-based methods (f(DNA)). Mortality of chicks and adults in captivity were also positively correlated with parental relatedness (r(DNA)) and f(DNA), respectively, while no correlation was observed with pedigree-based measures when controlling for additional variables such as age, breeding facility, gender and captive/release status. Further, individual homozygosity by loci (HL) and parental rDNA values were positively correlated with adult mortality in captivity and the occurrence of a lethal congenital defect in chicks, respectively, suggesting that inbreeding may be a contributing factor increasing the frequency of this condition among Attwater's Prairie-chickens. This study highlights the importance of using DNA-based methods to better inform management decisions when pedigrees are incomplete or errors may exist due to uncertainty in pairings. © 2013 John Wiley & Sons Ltd.

The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study.

PubMed

Cohen, Deborah A; Han, Bing; Evenson, Kelly R; Nagel, Catherine; McKenzie, Thomas L; Marsh, Terry; Williamson, Stephanie; Harnik, Peter

2017-02-01

Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170-174; http://dx.doi.org/10.1289/EHP293.

The Prevalence and Use of Walking Loops in Neighborhood Parks: A National Study

PubMed Central

Cohen, Deborah A.; Han, Bing; Evenson, Kelly R.; Nagel, Catherine; McKenzie, Thomas L.; Marsh, Terry; Williamson, Stephanie; Harnik, Peter

2016-01-01

Background: Previous studies indicate that the design of streets and sidewalks can influence physical activity among residents. Park features also influence park use and park-based physical activity. Although individuals can walk on streets and sidewalks, walking loops in parks offer a setting to walk in nature and to avoid interruptions from traffic. Objectives: Here we describe the use of walking loops in parks and compare the number of park users and their physical activity in urban neighborhood parks with and without walking loops. Methods: We analyzed data from the National Study of Neighborhood Parks in which a representative sample of neighborhood parks (n = 174) from 25 U.S. cities with > 100,000 population were observed systematically to document facilities and park users by age group and sex. We compared the number of people and their physical activity in parks with and without walking loops, controlling for multiple factors, including park size, facilities, and population density. Results: Overall, compared with parks without walking loops, on average during an hourly observation, parks with walking loops had 80% more users (95% CI: 42, 139%), and levels of moderate-to-vigorous physical activity were 90% higher (95% CI: 49, 145%). The additional park use and park-based physical activity occurred not only on the walking loops but throughout the park. Conclusions: Walking loops may be a promising means of increasing population level physical activity. Further studies are needed to confirm a causal relationship. Citation: Cohen DA, Han B, Evenson KR, Nagel C, McKenzie TL, Marsh T, Williamson S, Harnik P. 2017. The prevalence and use of walking loops in neighborhood parks: a national study. Environ Health Perspect 125:170–174; http://dx.doi.org/10.1289/EHP293 PMID:27517530

Evidence for a Constant Initial Mass Function in Early-type Galaxies Based on Their X-Ray Binary Populations

NASA Astrophysics Data System (ADS)

Peacock, Mark B.; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Gonzalez, Anthony H.; Lehmer, Bret D.; Maraston, Claudia

2014-04-01

A number of recent studies have proposed that the stellar initial mass function (IMF) of early type galaxies varies systematically as a function of galaxy mass, with higher mass galaxies having bottom-heavy IMFs. These bottom-heavy IMFs have more low-mass stars relative to the number of high mass stars, and therefore naturally result in proportionally fewer neutron stars (NSs) and black holes (BHs). In this paper, we specifically predict the variation in the number of BHs and NSs based on the power-law IMF variation required to reproduce the observed mass-to-light ratio trends with galaxy mass. We then test whether such variations are observed by studying the field low-mass X-ray binary (LMXB) populations of nearby early-type galaxies. In these binaries, an NS or BH accretes matter from a low-mass donor star. Their number is therefore expected to scale with the number of BHs and NSs present in a galaxy. We find that the number of LMXBs per K-band light is similar among the galaxies in our sample. These data therefore demonstrate the uniformity of the slope of the IMF from massive stars down to those now dominating the K-band light and are consistent with an invariant IMF. Our results are inconsistent with an IMF which varies from a Kroupa/Chabrier like IMF for low-mass galaxies to a steep power-law IMF (with slope x = 2.8) for high mass galaxies. We discuss how these observations constrain the possible forms of the IMF variations and how future Chandra observations can enable sharper tests of the IMF. Based in part on observations made with the NASA/ESA Hubble Space Telescope, and obtained from the Hubble Legacy Archive, which is a collaboration between the Space Telescope Science Institute (STScI/NASA), the Space Telescope European Coordinating Facility (ST-ECF/ESA) and the Canadian Astronomy Data Centre (CADC/NRC/CSA). The scientific results reported in this article are based in part on data obtained from the Chandra Data Archive and observations made by the Chandra X-ray Observatory and published previously in cited articles.

Galactic gamma-ray observations and galactic structure

NASA Technical Reports Server (NTRS)

Stecker, F. W.

1975-01-01

Recent observations of gamma-rays originating in the galactic disk together with radio observations, support an emerging picture of the overall structure of our galaxy with higher interstellar gas densities and star formation rates in a region which corresponds to that of the inner arms. The emerging picture is one where molecular clouds make up the dominant constituent of the interstellar gas in the inner galaxy and play a key role in accounting for the gamma-rays and phenomena associated with the production of young stars and other population 1 objects. In this picture, cosmic rays are associated with supernovae and are primarily of galactic origin. These newly observed phenomena can be understood as consequences of the density wave theories of spiral structure. Based on these new developments, the suggestion is made that a new galactic population class, Population O, be added to the standard Populations 1 and 2 in order to recognize important differences in dynamics and distribution between diffuse galactic H1 and interstellar molecular clouds.