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Sample records for contrasting demographic histories

  1. Contrasting patterns of population structure and demographic history in cryptic species of Bostrychia intricata (Rhodomelaceae, Rhodophyta) from New Zealand.

    Science.gov (United States)

    Muangmai, Narongrit; Fraser, Ceridwen I; Zuccarello, Giuseppe C

    2015-06-01

    Spatial patterns of genetic diversity provide insight into the demography and history of species. Morphologically similar but genetically distinct "cryptic" species are increasingly being recognized in marine organisms through molecular analyses. Such species are, on closer inspection, often discovered to display contrasting life histories or occasionally minor morphological differences; molecular tools can thus be useful indicators of diversity. Bostrychia intricata, a marine red alga, is widely distributed throughout the Southern Hemisphere and comprises many cryptic species. We used mitochondrial cytochrome c oxidase I gene sequences to assess the genetic variation, population genetic structure, and demographic history of B. intricata in New Zealand. Our results supported the existence of three cryptic species of B. intricata (N2, N4, and N5) in New Zealand. Cryptic species N4, which was found throughout New Zealand, showed a higher genetic diversity and wider distribution than the other two species, which were only found in the North Island and northern South Island. Our analyses showed low to moderate genetic differentiation among eastern North Island populations for cryptic species N2, but high differentiation among North and South Island populations for N4, suggesting different population structure between these cryptic species. Data also indicated that N2 has recently undergone population expansion, probably since the Last Glacial Maximum (LGM), while the higher genetic diversity in N4 populations suggests persistence in situ through the LGM. The contrasting population structures and inferred demographic histories of these species highlight that life history can vary greatly even among morphologically indistinguishable taxa. © 2015 Phycological Society of America.

  2. Contrasting demographic history and gene flow patterns of two mangrove species on either side of the Central American Isthmus

    Science.gov (United States)

    Cerón-Souza, Ivania; Gonzalez, Elena G; Schwarzbach, Andrea E; Salas-Leiva, Dayana E; Rivera-Ocasio, Elsie; Toro-Perea, Nelson; Bermingham, Eldredge; McMillan, W Owen

    2015-01-01

    Comparative phylogeography offers a unique opportunity to understand the interplay between past environmental events and life-history traits on diversification of unrelated but co-distributed species. Here, we examined the effects of the quaternary climate fluctuations and palaeomarine currents and present-day marine currents on the extant patterns of genetic diversity in the two most conspicuous mangrove species of the Neotropics. The black (Avicennia germinans, Avicenniaceae) and the red (Rhizophora mangle, Rhizophoraceae) mangroves have similar geographic ranges but are very distantly related and show striking differences on their life-history traits. We sampled 18 Atlantic and 26 Pacific locations for A. germinans (N = 292) and R. mangle (N = 422). We performed coalescence simulations using microsatellite diversity to test for evidence of population change associated with quaternary climate fluctuations. In addition, we examined whether patterns of genetic variation were consistent with the directions of major marine (historical and present day) currents in the region. Our demographic analysis was grounded within a phylogeographic framework provided by the sequence analysis of two chloroplasts and one flanking microsatellite region in a subsample of individuals. The two mangrove species shared similar biogeographic histories including: (1) strong genetic breaks between Atlantic and Pacific ocean basins associated with the final closure of the Central American Isthmus (CAI), (2) evidence for simultaneous population declines between the mid-Pleistocene and early Holocene, (3) asymmetric historical migration with higher gene flow from the Atlantic to the Pacific oceans following the direction of the palaeomarine current, and (4) contemporary gene flow between West Africa and South America following the major Atlantic Ocean currents. Despite the remarkable differences in life-history traits of mangrove species, which should have had a strong influence on seed

  3. Present-day genetic composition suggests contrasting demographic histories of two dominant chaetognaths of the Nort-East Atlantic, Sagitta elegans and S. setosa

    NARCIS (Netherlands)

    Peijnenburg, K.T.C.A.; van Haastrecht, E.K.; Fauvelot, C.Y.

    2005-01-01

    Sagitta elegans and S. setosa are the two dominant chaetognaths in the North-East (NE) Atlantic. They are closely related and have a similar ecology and life history, but differ in distributional ranges. Sagitta setosa is a typical neritic species occurring exclusively above shelf regions, whereas

  4. Population genetic structure and demographic history of small ...

    African Journals Online (AJOL)

    Population genetic structure and demographic history of small yellow croaker, ... diversity (0.0112 ± 0.0061 to 0.0141 ± 0.0075) were detected in the species. ... into two closely related clades, but did not appear to have any geographic ...

  5. Inferring Demographic History Using Two-Locus Statistics.

    Science.gov (United States)

    Ragsdale, Aaron P; Gutenkunst, Ryan N

    2017-06-01

    Population demographic history may be learned from contemporary genetic variation data. Methods based on aggregating the statistics of many single loci into an allele frequency spectrum (AFS) have proven powerful, but such methods ignore potentially informative patterns of linkage disequilibrium (LD) between neighboring loci. To leverage such patterns, we developed a composite-likelihood framework for inferring demographic history from aggregated statistics of pairs of loci. Using this framework, we show that two-locus statistics are more sensitive to demographic history than single-locus statistics such as the AFS. In particular, two-locus statistics escape the notorious confounding of depth and duration of a bottleneck, and they provide a means to estimate effective population size based on the recombination rather than mutation rate. We applied our approach to a Zambian population of Drosophila melanogaster Notably, using both single- and two-locus statistics, we inferred a substantially lower ancestral effective population size than previous works and did not infer a bottleneck history. Together, our results demonstrate the broad potential for two-locus statistics to enable powerful population genetic inference. Copyright © 2017 by the Genetics Society of America.

  6. The Demographic and Adaptive History of the African Green Monkey.

    Science.gov (United States)

    Pfeifer, Susanne P

    2017-05-01

    Relatively little is known about the evolutionary history of the African green monkey (genus Chlorocebus) due to the lack of sampled polymorphism data from wild populations. Yet, this characterization of genetic diversity is not only critical for a better understanding of their own history, but also for human biomedical research given that they are one of the most widely used primate models. Here, I analyze the demographic and selective history of the African green monkey, utilizing one of the most comprehensive catalogs of wild genetic diversity to date, consisting of 1,795,643 autosomal single nucleotide polymorphisms in 25 individuals, representing all five major populations: C. a. aethiops, C. a. cynosurus, C. a. pygerythrus, C. a. sabaeus, and C. a tantalus. Assuming a mutation rate of 5.9 × 10-9 per base pair per generation and a generation time of 8.5 years, divergence time estimates range from 523 to 621 kya for the basal split of C. a. aethiops from the other four populations. Importantly, the resulting tree characterizing the relationship and split-times between these populations differs significantly from that presented in the original genome paper, owing to their neglect of within-population variation when calculating between population-divergence. In addition, I find that the demographic history of all five populations is well explained by a model of population fragmentation and isolation, rather than novel colonization events. Finally, utilizing these demographic models as a null, I investigate the selective history of the populations, identifying candidate regions potentially related to adaptation in response to pathogen exposure. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  7. Contrasting demographic histories of the neighboring bonobo and chimpanzee

    DEFF Research Database (Denmark)

    Hvilsom, Christina; Carlsen, Frands; Heller, Rasmus

    2014-01-01

    of the neighboring bonobo remained constant. The changes in population size are likely linked to changes in habitat area due to climate oscillations during the late Pleistocene. Furthermore, the timing of population expansion for the rainforest-adapted chimpanzee is concurrent with the expansion of the savanna...

  8. Multilocus dataset reveals demographic histories of two peat mosses in Europe

    Directory of Open Access Journals (Sweden)

    Hock Zsófia

    2007-08-01

    Full Text Available Abstract Background Revealing the past and present demographic history of populations is of high importance to evaluate the conservation status of species. Demographic data can be obtained by direct monitoring or by analysing data of historical and recent collections. Although these methods provide the most detailed information they are very time consuming. Another alternative way is to make use of the information accumulated in the species' DNA over its history. Recent development of the coalescent theory makes it possible to reconstruct the demographic history of species using nucleotide polymorphism data. To separate the effect of natural selection and demography, multilocus analysis is needed because these two forces can produce similar patterns of polymorphisms. In this study we investigated the amount and pattern of sequence variability of a Europe wide sample set of two peat moss species (Sphagnum fimbriatum and S. squarrosum with similar distributions and mating systems but presumably contrasting historical demographies using 3 regions of the nuclear genome (appr. 3000 bps. We aimed to draw inferences concerning demographic, and phylogeographic histories of the species. Results All three nuclear regions supported the presence of an Atlantic and Non-Atlantic clade of S. fimbriatum suggesting glacial survival of the species along the Atlantic coast of Europe. Contrarily, S. squarrosum haplotypes showed three clades but no geographic structure at all. Maximum likelihood, mismatch and Bayesian analyses supported a severe historical bottleneck and a relatively recent demographic expansion of the Non-Atlantic clade of S. fimbriatum, whereas size of S. squarrosum populations has probably decreased in the past. Species wide molecular diversity of the two species was nearly the same with an excess of replacement mutations in S. fimbriatum. Similar levels of molecular diversity, contrasting phylogeographic patterns and excess of replacement

  9. Contrast echocardiography: history, micro bubble characteristics and instrumental techniques

    International Nuclear Information System (INIS)

    Cubides, Carlos; Restrepo, Gustavo; Aristizabal, Dagnovar; Munera, Ana

    2006-01-01

    This article describes the history of contrast echocardiography, the physical characteristics of the contrast agent's micro bubbles, the main instrumental tools (mechanical index, focus and focusing, frame rate), and the echocardiography techniques (second harmonic imaging, fusion harmonic, power pulse inversion imaging, triggered imaging, intermittent harmonic power Doppler, color power angio and acoustic densitometry), actually available for clinical use

  10. Domestication and human demographic history in South America.

    Science.gov (United States)

    Perez, S Ivan; Postillone, María Bárbara; Rindel, Diego

    2017-05-01

    The early groups of hunter-gatherers who peopled South America faced significant ecological changes in their trophic niche for a relatively short period after the initial peopling. In particular, the incorporation of cultigens during the Holocene led to a wider trophic niche and probably to an increased carrying capacity of the environment. Here, we study the relationship between the incorporation of domestic resources during the Holocene and the demographic dynamics of human populations at a regional scale in South America. We employ mitochondrial DNA (mtDNA), radiocarbon data and Bayesian methods to estimate differences in population size, human occupation and explore the demographic changes of human populations in three regions (i.e., South-Central Andes, Northwest, and South Patagonia). We also use archaeological evidence to infer the main diet changes in these regions. The absolute population size during the later Late Holocene was fifteen times larger in the South-Central Andes than in Northwest Patagonia, and two times larger in the latter region than in South Patagonia. The South-Central Andes display the earlier and more abrupt population growth, beginning about 9000 years BP, whereas Northwest Patagonia exhibits a more slow growth, beginning about 7000-7500 years BP. South Patagonia represents a later and slower population increase. In this work we uncovered a well-supported pattern of the demographic change in the populations from South-Central Andes and Patagonia, obtained on the basis of different data and quantitative approaches, which suggests that the incorporation of domestic resources was paramount for the demographic expansion of these populations during the Holocene. © 2017 Wiley Periodicals, Inc.

  11. Demographic history and biologically relevant genetic variation of Native Mexicans inferred from whole-genome sequencing

    OpenAIRE

    Romero-Hidalgo, Sandra; Ochoa-Leyva, Adrián; Garcíarrubio, Alejandro; Acuña-Alonzo, Victor; Antúnez-Argüelles, Erika; Balcazar-Quintero, Martha; Barquera-Lozano, Rodrigo; Carnevale, Alessandra; Cornejo-Granados, Fernanda; Fernández-López, Juan Carlos; García-Herrera, Rodrigo; García-Ortíz, Humberto; Granados-Silvestre, Ángeles; Granados, Julio; Guerrero-Romero, Fernando

    2017-01-01

    Understanding the genetic structure of Native American populations is important to clarify their diversity, demographic history, and to identify genetic factors relevant for biomedical traits. Here, we show a demographic history reconstruction from 12 Native American whole genomes belonging to six distinct ethnic groups representing the three main described genetic clusters of Mexico (Northern, Southern, and Maya). Effective population size estimates of all Native American groups remained bel...

  12. Inferring demographic history from a spectrum of shared haplotype lengths

    DEFF Research Database (Denmark)

    Harris, Kelley; Nielsen, Rasmus

    2013-01-01

    There has been much recent excitement about the use of genetics to elucidate ancestral history and demography. Whole genome data from humans and other species are revealing complex stories of divergence and admixture that were left undiscovered by previous smaller data sets. A central challenge...... is to estimate the timing of past admixture and divergence events, for example the time at which Neanderthals exchanged genetic material with humans and the time at which modern humans left Africa. Here, we present a method for using sequence data to jointly estimate the timing and magnitude of past admixture...

  13. Formal linguistics as a cue to demographic history.

    Science.gov (United States)

    Longobardi, Giuseppe; Ceolin, Andrea; Ecay, Aaron; Ghirotto, Silvia; Guardiano, Cristina; Irimia, Monica-Alexandrina; Michelioudakis, Dimitris; Radkevich, Nina; Pettener, Davide; Luiselli, Donata; Barbujani, Guido

    2016-06-20

    Beyond its theoretical success, the development of molecular genetics has brought about the possibility of extraordinary progress in the study of classification and in the inference of the evolutionary history of many species and populations. A major step forward was represented by the availability of extremely large sets of molecular data suited to quantitative and computational treatments. In this paper, we argue that even in cognitive sciences, purely theoretical progress in a discipline such as linguistics may have analogous impact. Thus, exactly on the model of molecular biology, we propose to unify two traditionally unrelated lines of linguistic investigation: 1) the formal study of syntactic variation (parameter theory) in the biolinguistic program; 2) the reconstruction of relatedness among languages (phylogenetic taxonomy). The results of our linguistic analysis have thus been plotted against data from population genetics and the correlations have turned out to be largely significant: given a non-trivial set of languages/populations, the description of their variation provided by the comparison of systematic parametric analysis and molecular anthropology informatively recapitulates their history and relationships. As a result, we can claim that the reality of some parametric model of the language faculty and language acquisition/transmission (more broadly of generative grammar) receives strong and original support from its historical heuristic power. Then, on these grounds, we can begin testing Darwin's prediction that, when properly generated, the trees of human populations and of their languages should eventually turn out to be significantly parallel.

  14. Population Demographic History Can Cause the Appearance of Recombination Hotspots

    Science.gov (United States)

    Johnston, Henry R.; Cutler, David J.

    2012-01-01

    Although the prevailing view among geneticists suggests that recombination hotspots exist ubiquitously across the human genome, there is only limited experimental evidence from a few genomic regions to support the generality of this claim. A small number of true recombination hotspots are well supported experimentally, but the vast majority of hotspots have been identified on the basis of population genetic inferences from the patterns of linkage disequilibrium (LD) seen in the human population. These inferences are made assuming a particular model of human history, and one of the assumptions of that model is that the effective population size of humans has remained constant throughout our history. Our results show that relaxation of the constant population size assumption can create LD and variation patterns that are qualitatively and quantitatively similar to human populations without any need to invoke localized hotspots of recombination. In other words, apparent recombination hotspots could be an artifact of variable population size over time. Several lines of evidence suggest that the vast majority of hotspots identified on the basis of LD information are unlikely to have elevated recombination rates. PMID:22560089

  15. Inferring the demographic history of European Ficedula flycatcher populations

    Directory of Open Access Journals (Sweden)

    Backström Niclas

    2013-01-01

    Full Text Available Abstract Background Inference of population and species histories and population stratification using genetic data is important for discriminating between different speciation scenarios and for correct interpretation of genome scans for signs of adaptive evolution and trait association. Here we use data from 24 intronic loci re-sequenced in population samples of two closely related species, the pied flycatcher and the collared flycatcher. Results We applied Isolation-Migration models, assignment analyses and estimated the genetic differentiation and diversity between species and between populations within species. The data indicate a divergence time between the species of Conclusions Our results provide further evidence for a divergence process where different genomic regions may be at different stages of speciation. We also conclude that forthcoming analyses of genotype-phenotype relations in these ecological model species should be designed to take population stratification into account.

  16. Contrasted demographic responses facing future climate change in Southern Ocean seabirds.

    Science.gov (United States)

    Barbraud, Christophe; Rivalan, Philippe; Inchausti, Pablo; Nevoux, Marie; Rolland, Virginie; Weimerskirch, Henri

    2011-01-01

    1. Recent climate change has affected a wide range of species, but predicting population responses to projected climate change using population dynamics theory and models remains challenging, and very few attempts have been made. The Southern Ocean sea surface temperature and sea ice extent are projected to warm and shrink as concentrations of atmospheric greenhouse gases increase, and several top predator species are affected by fluctuations in these oceanographic variables. 2. We compared and projected the population responses of three seabird species living in sub-tropical, sub-Antarctic and Antarctic biomes to predicted climate change over the next 50 years. Using stochastic population models we combined long-term demographic datasets and projections of sea surface temperature and sea ice extent for three different IPCC emission scenarios (from most to least severe: A1B, A2, B1) from general circulation models of Earth's climate. 3. We found that climate mostly affected the probability to breed successfully, and in one case adult survival. Interestingly, frequent nonlinear relationships in demographic responses to climate were detected. Models forced by future predicted climatic change provided contrasted population responses depending on the species considered. The northernmost distributed species was predicted to be little affected by a future warming of the Southern Ocean, whereas steep declines were projected for the more southerly distributed species due to sea surface temperature warming and decrease in sea ice extent. For the most southerly distributed species, the A1B and B1 emission scenarios were respectively the most and less damaging. For the two other species, population responses were similar for all emission scenarios. 4. This is among the first attempts to study the demographic responses for several populations with contrasted environmental conditions, which illustrates that investigating the effects of climate change on core population dynamics

  17. Effects of Demographic History on the Detection of Recombination Hotspots from Linkage Disequilibrium.

    Science.gov (United States)

    Dapper, Amy L; Payseur, Bret A

    2018-02-01

    In some species, meiotic recombination is concentrated in small genomic regions. These "recombination hotspots" leave signatures in fine-scale patterns of linkage disequilibrium, raising the prospect that the genomic landscape of hotspots can be characterized from sequence variation. This approach has led to the inference that hotspots evolve rapidly in some species, but are conserved in others. Historic demographic events, such as population bottlenecks, are known to affect patterns of linkage disequilibrium across the genome, violating population genetic assumptions of this approach. Although such events are prevalent, demographic history is generally ignored when making inferences about the evolution of recombination hotspots. To determine the effect of demography on the detection of recombination hotspots, we use the coalescent to simulate haplotypes with a known recombination landscape. We measure the ability of popular linkage disequilibrium-based programs to detect hotspots across a range of demographic histories, including population bottlenecks, hidden population structure, population expansions, and population contractions. We find that demographic events have the potential to greatly reduce the power and increase the false positive rate of hotspot discovery. Neither the power nor the false positive rate of hotspot detection can be predicted without also knowing the demographic history of the sample. Our results suggest that ignoring demographic history likely overestimates the power to detect hotspots and therefore underestimates the degree of hotspot sharing between species. We suggest strategies for incorporating demographic history into population genetic inferences about recombination hotspots. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  18. Demographics.

    Science.gov (United States)

    Gillis, Artha J; Bath, Eraka

    2016-01-01

    There is a large proportion of minority youth involved in the juvenile justice system. Disproportionate minority contact (DMC) occurs when the proportion of any ethnic group is higher at any given stage in the juvenile justice process than the proportion of this group in the general population. There are several theories explaining the presence and persistence of DMC. This article reviews the history of DMC and the theories and implications of this problem. It discusses several targets for interventions designed to reduce DMC and offer resources in this area. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. MUSIDH, multiple use of simulated demographic histories, a novel method to reduce computation time in microsimulation models of infectious diseases.

    Science.gov (United States)

    Fischer, E A J; De Vlas, S J; Richardus, J H; Habbema, J D F

    2008-09-01

    Microsimulation of infectious diseases requires simulation of many life histories of interacting individuals. In particular, relatively rare infections such as leprosy need to be studied in very large populations. Computation time increases disproportionally with the size of the simulated population. We present a novel method, MUSIDH, an acronym for multiple use of simulated demographic histories, to reduce computation time. Demographic history refers to the processes of birth, death and all other demographic events that should be unrelated to the natural course of an infection, thus non-fatal infections. MUSIDH attaches a fixed number of infection histories to each demographic history, and these infection histories interact as if being the infection history of separate individuals. With two examples, mumps and leprosy, we show that the method can give a factor 50 reduction in computation time at the cost of a small loss in precision. The largest reductions are obtained for rare infections with complex demographic histories.

  20. Tobacco availability and point of sale marketing in demographically contrasting districts of Massachusetts.

    Science.gov (United States)

    Laws, M Barton; Whitman, J; Bowser, D M; Krech, L

    2002-06-01

    To assess the prevalence and characteristics of tobacco sales and point-of-sale promotions and advertising in predominantly Latino business districts, and in comparison districts; and the economic importance of tobacco sales and marketing to Latino owned small businesses. Observational surveys of retail establishments and interviews with store managers. Demographically contrasting business districts of eastern Massachusetts. Percentage of businesses selling tobacco, numbers and characteristics of exterior and interior tobacco advertisements per store, merchant reports of promotional allowances received from tobacco distributors. The proportion of businesses selling tobacco, and hence having storefront tobacco advertising, is strongly negatively correlated with per capita income in the census tracts where businesses are located (Spearman's rho = -0.794, p = 0.006). Mentholated brands are marketed disproportionately in low income, urban communities. Latino merchants are highly dependent on tobacco sales, but would require relatively modest compensation to forego tobacco promotional allowances. Storefront tobacco advertising is far more prevalent in predominantly minority, low income communities than in non-minority, higher income communities, principally because of the differing mix of kinds of businesses in the two types of communities, and the greater prevalence of tobacco vendors in lower income neighbourhoods. Tobacco companies obtain this advertising at little cost.

  1. The confounding effect of population structure on bayesian skyline plot inferences of demographic history

    DEFF Research Database (Denmark)

    Heller, Rasmus; Chikhi, Lounes; Siegismund, Hans

    2013-01-01

    Many coalescent-based methods aiming to infer the demographic history of populations assume a single, isolated and panmictic population (i.e. a Wright-Fisher model). While this assumption may be reasonable under many conditions, several recent studies have shown that the results can be misleading...... when it is violated. Among the most widely applied demographic inference methods are Bayesian skyline plots (BSPs), which are used across a range of biological fields. Violations of the panmixia assumption are to be expected in many biological systems, but the consequences for skyline plot inferences...... the best scheme for inferring demographic change over a typical time scale. Analyses of data from a structured African buffalo population demonstrate how BSP results can be strengthened by simulations. We recommend that sample selection should be carefully considered in relation to population structure...

  2. Revealing life-history traits by contrasting genetic estimations with predictions of effective population size.

    Science.gov (United States)

    Greenbaum, Gili; Renan, Sharon; Templeton, Alan R; Bouskila, Amos; Saltz, David; Rubenstein, Daniel I; Bar-David, Shirli

    2017-12-22

    Effective population size, a central concept in conservation biology, is now routinely estimated from genetic surveys and can also be theoretically predicted from demographic, life-history, and mating-system data. By evaluating the consistency of theoretical predictions with empirically estimated effective size, insights can be gained regarding life-history characteristics and the relative impact of different life-history traits on genetic drift. These insights can be used to design and inform management strategies aimed at increasing effective population size. We demonstrated this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimated the variance effective size (N ev ) from genetic data (N ev =24.3) and formulated predictions for the impacts on N ev of demography, polygyny, female variance in lifetime reproductive success (RS), and heritability of female RS. By contrasting the genetic estimation with theoretical predictions, we found that polygyny was the strongest factor affecting genetic drift because only when accounting for polygyny were predictions consistent with the genetically measured N ev . The comparison of effective-size estimation and predictions indicated that 10.6% of the males mated per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ) and 19.5% mated when female RS was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female RS also affected N ev ; hf2=0.91 (heritability responsible for 41% decrease in N ev ). The low effective size is of concern, and we suggest that management actions focus on factors identified as strongly affecting Nev, namely, increasing the availability of artificial water sources to increase number of dominant males contributing to the gene pool. This approach, evaluating life-history hypotheses in light of their impact on effective population size, and contrasting

  3. A training manual for event history data management using Health and Demographic Surveillance System data.

    Science.gov (United States)

    Bocquier, Philippe; Ginsburg, Carren; Herbst, Kobus; Sankoh, Osman; Collinson, Mark A

    2017-06-26

    The objective of this research note is to introduce a training manual for event history data management. The manual provides a first comprehensive guide to longitudinal Health and Demographic Surveillance System (HDSS) data management that allows for a step-by-step description of the process of structuring and preparing a dataset for the calculation of demographic rates and event history analysis. The research note provides some background information on the INDEPTH Network, and the iShare data repository and describes the need for a manual to guide users as to how to correctly handle HDSS datasets. The approach outlined in the manual is flexible and can be applied to other longitudinal data sources. It facilitates the development of standardised longitudinal data management and harmonization of datasets to produce a comparative set of results.

  4. The significance of the allergy history in the use of intravenous X-ray contrast media

    International Nuclear Information System (INIS)

    Schmidt, M.; Kroczek, U.

    1986-01-01

    A restrospective study correlating allergy histories and reactions to X-ray contrast media was performed with a study group containing 519 patients receiving intravenous and infusion cholangiograms and 827 patients receiving intravenous and infusion pyelograms. Reactions against X-ray contrast media were observed significantly more frequently among patients with a positive allergy history independent of the suspected allergy (p [de

  5. Blacktip reef sharks, Carcharhinus melanopterus, have high genetic structure and varying demographic histories in their Indo-Pacific range

    KAUST Repository

    Vignaud, Thomas M.; Mourier, Johann; Maynard, Jeffrey Allen; Leblois, Raphaë l; Spaet, Julia L.Y.; Clua, É ric; Neglia, Valentina; Planes, Serge

    2014-01-01

    For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics

  6. Life history tactics shape amphibians' demographic responses to the North Atlantic Oscillation.

    Science.gov (United States)

    Cayuela, Hugo; Joly, Pierre; Schmidt, Benedikt R; Pichenot, Julian; Bonnaire, Eric; Priol, Pauline; Peyronel, Olivier; Laville, Mathias; Besnard, Aurélien

    2017-11-01

    Over the last three decades, climate abnormalities have been reported to be involved in biodiversity decline by affecting population dynamics. A growing number of studies have shown that the North Atlantic Oscillation (NAO) influences the demographic parameters of a wide range of plant and animal taxa in different ways. Life history theory could help to understand these different demographic responses to the NAO. Indeed, theory states that the impact of weather variation on a species' demographic traits should depend on its position along the fast-slow continuum. In particular, it is expected that NAO would have a higher impact on recruitment than on adult survival in slow species, while the opposite pattern is expected occur in fast species. To test these predictions, we used long-term capture-recapture datasets (more than 15,000 individuals marked from 1965 to 2015) on different surveyed populations of three amphibian species in Western Europe: Triturus cristatus, Bombina variegata, and Salamandra salamandra. Despite substantial intraspecific variation, our study revealed that these three species differ in their position on a slow-fast gradient of pace of life. Our results also suggest that the differences in life history tactics influence amphibian responses to NAO fluctuations: Adult survival was most affected by the NAO in the species with the fastest pace of life (T. cristatus), whereas recruitment was most impacted in species with a slower pace of life (B. variegata and S. salamandra). In the context of climate change, our findings suggest that the capacity of organisms to deal with future changes in NAO values could be closely linked to their position on the fast-slow continuum. © 2017 John Wiley & Sons Ltd.

  7. Demographic history and population structure of Anopheles pseudopunctipennis in Argentina based on the mitochondrial COI gene.

    Science.gov (United States)

    Dantur Juri, María J; Moreno, Marta; Prado Izaguirre, Mónica J; Navarro, Juan C; Zaidenberg, Mario O; Almirón, Walter R; Claps, Guillermo L; Conn, Jan E

    2014-09-04

    Anopheles pseudopunctipennis is an important malaria vector in the Neotropical region and the only species involved in Plasmodium transmission in the Andean foothills. Its wide geographical distribution in America, high preference for biting humans and capacity to rest inside dwellings after feeding, are attributes contributing to its vector status. Previous reports have tried to elucidate its taxonomic status, distinguishing populations from North, Central and South America. In the present study we used a mitochondrial marker to examine the demographic history of An. pseudopunctipennis in northwestern Argentina. Twelve localities were selected across 550 km of the distribution of this species in Argentina, including two near the Bolivian border and several in South Tucumán, for sampling. A fragment of the cytochrome oxidase I (COI) gene was sequenced and haplotype relationships were analyzed by a statistical parsimony network and a Neighbor-Joining (NJ) tree. Genetic differentiation was estimated with FST. Historical demographic processes were evaluated using diversity measures, neutrality tests and mismatch distribution. Forty-one haplotypes were identified, of which haplotype A was the most common and widely distributed. Neither the network nor the NJ tree showed any geographic differentiation between northern and southern populations. Haplotype diversities, Tajima's DT and Fu & Li's F and D neutrality tests and mismatch distribution supported a scenario of Holocene demographic expansion. The demographic pattern suggests that An. pseudopunctipennis has undergone a single colonization process, and the ancestral haplotype is shared by specimens from all localities, indicating mitochondrial gene flow. Genetic differentiation was minimal, observed only between one northern and one southern locality. The estimated time of the population expansion of this species was during the Holocene. These data suggest that regional vector control measures would be equally

  8. Genomic Insights into the Ancestry and Demographic History of South America

    Science.gov (United States)

    Homburger, Julian R.; Moreno-Estrada, Andrés; Gignoux, Christopher R.; Nelson, Dominic; Sanchez, Elena; Ortiz-Tello, Patricia; Pons-Estel, Bernardo A.; Acevedo-Vasquez, Eduardo; Miranda, Pedro; Langefeld, Carl D.; Gravel, Simon; Alarcón-Riquelme, Marta E.; Bustamante, Carlos D.

    2015-01-01

    South America has a complex demographic history shaped by multiple migration and admixture events in pre- and post-colonial times. Settled over 14,000 years ago by Native Americans, South America has experienced migrations of European and African individuals, similar to other regions in the Americas. However, the timing and magnitude of these events resulted in markedly different patterns of admixture throughout Latin America. We use genome-wide SNP data for 437 admixed individuals from 5 countries (Colombia, Ecuador, Peru, Chile, and Argentina) to explore the population structure and demographic history of South American Latinos. We combined these data with population reference panels from Africa, Asia, Europe and the Americas to perform global ancestry analysis and infer the subcontinental origin of the European and Native American ancestry components of the admixed individuals. By applying ancestry-specific PCA analyses we find that most of the European ancestry in South American Latinos is from the Iberian Peninsula; however, many individuals trace their ancestry back to Italy, especially within Argentina. We find a strong gradient in the Native American ancestry component of South American Latinos associated with country of origin and the geography of local indigenous populations. For example, Native American genomic segments in Peruvians show greater affinities with Andean indigenous peoples like Quechua and Aymara, whereas Native American haplotypes from Colombians tend to cluster with Amazonian and coastal tribes from northern South America. Using ancestry tract length analysis we modeled post-colonial South American migration history as the youngest in Latin America during European colonization (9–14 generations ago), with an additional strong pulse of European migration occurring between 3 and 9 generations ago. These genetic footprints can impact our understanding of population-level differences in biomedical traits and, thus, inform future medical

  9. Genomic Insights into the Ancestry and Demographic History of South America.

    Science.gov (United States)

    Homburger, Julian R; Moreno-Estrada, Andrés; Gignoux, Christopher R; Nelson, Dominic; Sanchez, Elena; Ortiz-Tello, Patricia; Pons-Estel, Bernardo A; Acevedo-Vasquez, Eduardo; Miranda, Pedro; Langefeld, Carl D; Gravel, Simon; Alarcón-Riquelme, Marta E; Bustamante, Carlos D

    2015-12-01

    South America has a complex demographic history shaped by multiple migration and admixture events in pre- and post-colonial times. Settled over 14,000 years ago by Native Americans, South America has experienced migrations of European and African individuals, similar to other regions in the Americas. However, the timing and magnitude of these events resulted in markedly different patterns of admixture throughout Latin America. We use genome-wide SNP data for 437 admixed individuals from 5 countries (Colombia, Ecuador, Peru, Chile, and Argentina) to explore the population structure and demographic history of South American Latinos. We combined these data with population reference panels from Africa, Asia, Europe and the Americas to perform global ancestry analysis and infer the subcontinental origin of the European and Native American ancestry components of the admixed individuals. By applying ancestry-specific PCA analyses we find that most of the European ancestry in South American Latinos is from the Iberian Peninsula; however, many individuals trace their ancestry back to Italy, especially within Argentina. We find a strong gradient in the Native American ancestry component of South American Latinos associated with country of origin and the geography of local indigenous populations. For example, Native American genomic segments in Peruvians show greater affinities with Andean indigenous peoples like Quechua and Aymara, whereas Native American haplotypes from Colombians tend to cluster with Amazonian and coastal tribes from northern South America. Using ancestry tract length analysis we modeled post-colonial South American migration history as the youngest in Latin America during European colonization (9-14 generations ago), with an additional strong pulse of European migration occurring between 3 and 9 generations ago. These genetic footprints can impact our understanding of population-level differences in biomedical traits and, thus, inform future medical

  10. Genomic Insights into the Ancestry and Demographic History of South America.

    Directory of Open Access Journals (Sweden)

    Julian R Homburger

    2015-12-01

    Full Text Available South America has a complex demographic history shaped by multiple migration and admixture events in pre- and post-colonial times. Settled over 14,000 years ago by Native Americans, South America has experienced migrations of European and African individuals, similar to other regions in the Americas. However, the timing and magnitude of these events resulted in markedly different patterns of admixture throughout Latin America. We use genome-wide SNP data for 437 admixed individuals from 5 countries (Colombia, Ecuador, Peru, Chile, and Argentina to explore the population structure and demographic history of South American Latinos. We combined these data with population reference panels from Africa, Asia, Europe and the Americas to perform global ancestry analysis and infer the subcontinental origin of the European and Native American ancestry components of the admixed individuals. By applying ancestry-specific PCA analyses we find that most of the European ancestry in South American Latinos is from the Iberian Peninsula; however, many individuals trace their ancestry back to Italy, especially within Argentina. We find a strong gradient in the Native American ancestry component of South American Latinos associated with country of origin and the geography of local indigenous populations. For example, Native American genomic segments in Peruvians show greater affinities with Andean indigenous peoples like Quechua and Aymara, whereas Native American haplotypes from Colombians tend to cluster with Amazonian and coastal tribes from northern South America. Using ancestry tract length analysis we modeled post-colonial South American migration history as the youngest in Latin America during European colonization (9-14 generations ago, with an additional strong pulse of European migration occurring between 3 and 9 generations ago. These genetic footprints can impact our understanding of population-level differences in biomedical traits and, thus, inform

  11. Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula: multiple refugia, range expansions and secondary contact zones

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    Hewitt Godfrey M

    2011-06-01

    Full Text Available Abstract Background The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results Results support the existence of 6 evolutionary lineages (phylogroups with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. Conclusions The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a

  12. Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula: multiple refugia, range expansions and secondary contact zones.

    Science.gov (United States)

    Miraldo, Andreia; Hewitt, Godfrey M; Paulo, Octavio S; Emerson, Brent C

    2011-06-17

    The Iberian Peninsula is recognized as an important refugial area for species survival and diversification during the climatic cycles of the Quaternary. Recent phylogeographic studies have revealed Iberia as a complex of multiple refugia. However, most of these studies have focused either on species with narrow distributions within the region or species groups that, although widely distributed, generally have a genetic structure that relates to pre-Quaternary cladogenetic events. In this study we undertake a detailed phylogeographic analysis of the lizard species, Lacerta lepida, whose distribution encompasses the entire Iberian Peninsula. We attempt to identify refugial areas, recolonization routes, zones of secondary contact and date demographic events within this species. Results support the existence of 6 evolutionary lineages (phylogroups) with a strong association between genetic variation and geography, suggesting a history of allopatric divergence in different refugia. Diversification within phylogroups is concordant with the onset of the Pleistocene climatic oscillations. The southern regions of several phylogroups show a high incidence of ancestral alleles in contrast with high incidence of recently derived alleles in northern regions. All phylogroups show signs of recent demographic and spatial expansions. We have further identified several zones of secondary contact, with divergent mitochondrial haplotypes occurring in narrow zones of sympatry. The concordant patterns of spatial and demographic expansions detected within phylogroups, together with the high incidence of ancestral haplotypes in southern regions of several phylogroups, suggests a pattern of contraction of populations into southern refugia during adverse climatic conditions from which subsequent northern expansions occurred. This study supports the emergent pattern of multiple refugia within Iberia but adds to it by identifying a pattern of refugia coincident with the southern distribution

  13. L'analyse contrastive: histoire et situation actuelle (Contrastive Analysis: History and Current Situation).

    Science.gov (United States)

    Py, Bernard

    1984-01-01

    It is suggested that it is not between two languages that transfers and interference occur, but within the learner. The learner mediates and constructs this relationship according to acquisition operations, processes, strategies, and stages that contrastive analysis, despite its utility, can neither account for nor predict. (MSE)

  14. Genome - wide variation and demographic history of small cats with a focus on Felis species

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    Anubhab Khan

    2017-10-01

    Full Text Available Majority of the 38 known cat species are classified as small and they inhabit five of the seven continents. They survive in a vast range of habitats but still 12 out of the 18 threatened felids are small cats. However, there has not been enough progress in the field of small cat research as they generally get overshadowed by the charismatic big cats. Here we attempt to create a resource for small cat research especially of the genus Felis which has six species out of which two are classified as vulnerable by IUCN and at least one more is at risk. We collected tissue samples of four Felis chaus (Jungle cat from central India and used available whole genome sequences of nine individuals from four other Felis species, two individuals of Prionailurus bengalensis and an Otocolobus manul. These whole genome sequences were filtered and aligned with the already published domestic cat (Felis catus genome assembly. Felids are closely related species and reads from all species in our study aligned with the domestic cat genome with a rate of at least 93%. We estimated the existing genomic variation by calculating heterozygous SNP encounter rate. So far, it seems that all wild cats have more genetic variation than Felis catus species. This can be attributed to the inbreeding in these cats. Among the wild cats, Felis silvestris seems to have the highest level of genetic variation. To understand the reasons behind the distribution of genetic variation in small cats, we estimated the demographic histories of each of the species using PSMC. This method can only detect demographic changes more than 1000 generations ago. We observe that roughly all species share a parallel history in terms of population increase. The most interesting and important feature might be that all wild small cat population sizes increased exponentially around twenty thousand years ago as opposed to domestic cat and big cats which declined around this time. Another interesting feature of

  15. Whole-genome sequencing of giant pandas provides insights into demographic history and local adaptation

    DEFF Research Database (Denmark)

    Zhao, Shancen; Zheng, Pingping; Dong, Shanshan

    2013-01-01

    The panda lineage dates back to the late Miocene and ultimately leads to only one extant species, the giant panda (Ailuropoda melanoleuca). Although global climate change and anthropogenic disturbances are recognized to shape animal population demography their contribution to panda population...... dynamics remains largely unknown. We sequenced the whole genomes of 34 pandas at an average 4.7-fold coverage and used this data set together with the previously deep-sequenced panda genome to reconstruct a continuous demographic history of pandas from their origin to the present. We identify two...... panda populations that show genetic adaptation to their environments. However, in all three populations, anthropogenic activities have negatively affected pandas for 3,000 years....

  16. Meat and Nicotinamide: A Causal Role in Human Evolution, History, and Demographics

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    Adrian C Williams

    2017-04-01

    Full Text Available Hunting for meat was a critical step in all animal and human evolution. A key brain-trophic element in meat is vitamin B 3 /nicotinamide. The supply of meat and nicotinamide steadily increased from the Cambrian origin of animal predators ratcheting ever larger brains. This culminated in the 3-million-year evolution of Homo sapiens and our overall demographic success. We view human evolution, recent history, and agricultural and demographic transitions in the light of meat and nicotinamide intake. A biochemical and immunological switch is highlighted that affects fertility in the ‘de novo’ tryptophan-to-kynurenine-nicotinamide ‘immune tolerance’ pathway. Longevity relates to nicotinamide adenine dinucleotide consumer pathways. High meat intake correlates with moderate fertility, high intelligence, good health, and longevity with consequent population stability, whereas low meat/high cereal intake (short of starvation correlates with high fertility, disease, and population booms and busts. Too high a meat intake and fertility falls below replacement levels. Reducing variances in meat consumption might help stabilise population growth and improve human capital.

  17. Genome-wide Ancestry and Demographic History of African-Descendant Maroon Communities from French Guiana and Suriname.

    Science.gov (United States)

    Fortes-Lima, Cesar; Gessain, Antoine; Ruiz-Linares, Andres; Bortolini, Maria-Cátira; Migot-Nabias, Florence; Bellis, Gil; Moreno-Mayar, J Víctor; Restrepo, Berta Nelly; Rojas, Winston; Avendaño-Tamayo, Efren; Bedoya, Gabriel; Orlando, Ludovic; Salas, Antonio; Helgason, Agnar; Gilbert, M Thomas P; Sikora, Martin; Schroeder, Hannes; Dugoujon, Jean-Michel

    2017-11-02

    The transatlantic slave trade was the largest forced migration in world history. However, the origins of the enslaved Africans and their admixture dynamics remain unclear. To investigate the demographic history of African-descendant Marron populations, we generated genome-wide data (4.3 million markers) from 107 individuals from three African-descendant populations in South America, as well as 124 individuals from six west African populations. Throughout the Americas, thousands of enslaved Africans managed to escape captivity and establish lasting communities, such as the Noir Marron. We find that this population has the highest proportion of African ancestry (∼98%) of any African-descendant population analyzed to date, presumably because of centuries of genetic isolation. By contrast, African-descendant populations in Brazil and Colombia harbor substantially more European and Native American ancestry as a result of their complex admixture histories. Using ancestry tract-length analysis, we detect different dates for the European admixture events in the African-Colombian (1749 CE; confidence interval [CI]: 1737-1764) and African-Brazilian (1796 CE; CI: 1789-1804) populations in our dataset, consistent with the historically attested earlier influx of Africans into Colombia. Furthermore, we find evidence for sex-specific admixture patterns, resulting from predominantly European paternal gene flow. Finally, we detect strong genetic links between the African-descendant populations and specific source populations in Africa on the basis of haplotype sharing patterns. Although the Noir Marron and African-Colombians show stronger affinities with African populations from the Bight of Benin and the Gold Coast, the African-Brazilian population from Rio de Janeiro has greater genetic affinity with Bantu-speaking populations from the Bight of Biafra and west central Africa. Copyright © 2017 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  18. Demographic trajectories of Baja California and California, 1900-2000. Contrasts and parallelisms

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    David Piñera Ramírez

    2012-07-01

    Full Text Available The purpose is to analyze migration processes that have occurred in two neighboring states, pointing out the characteristics acquired in each of them, especially regarding their origin and type of labor relations they have produced. Therefore, the migration as the thematic axis and following the guidelines of comparative history, it is shown that both in California and in Baja California, migration flows have played a fundamental role. The comparative appro­ach also leads to the search for similarities and differences represented in different moments, such as the impact of "Prohibition", the Great Depression and two World Wars, or specific phenomena as the arrival of the railroad. But above all, the common thread is migration with its two key issues mentioned above, the origin of migration flows and labor relations that they have generated in the two Californias.

  19. Socio-demographic Characteristics of Individuals with History of Crack Cocaine Use in the US General Population.

    Science.gov (United States)

    Yur'yev, Andriy; Akerele, Evaristo

    2016-11-01

    This study explores socio-demographic characteristics of individuals with history of crack cocaine use. Data from the 29th Round of General Social Survey was used. Respondents with history of crack cocaine use were compared to respondents without such history. T test was applied to identify differences between groups. Approximately 6 % of respondents reported lifetime history of crack cocaine use. Groups with and without history of crack cocaine use differed significantly in gender, marital status, education, income distribution, employment, health perception, family and financial satisfaction, criminal history, happiness, sexual history, history of injection drug use, and HIV testing. There were no significant differences for race. The study provides insights that could improve identification and prevention of substance use disorders.

  20. Costs of fear: Behavioral and life-history responses to risk and their demographic consequences vary across species

    Science.gov (United States)

    LaManna, Joseph A.; Martin, Thomas E.

    2016-01-01

    Behavioural responses to reduce predation risk might cause demographic ‘costs of fear’. Costs differ among species, but a conceptual framework to understand this variation is lacking. We use a life-history framework to tie together diverse traits and life stages to better understand interspecific variation in responses and costs. We used natural and experimental variation in predation risk to test phenotypic responses and associated demographic costs for 10 songbird species. Responses such as increased parental attentiveness yielded reduced development time and created benefits such as reduced predation probability. Yet, responses to increased risk also created demographic costs by reducing offspring production in the absence of direct predation. This cost of fear varied widely across species, but predictably with the probability of repeat breeding. Use of a life-history framework can aid our understanding of potential demographic costs from predation, both from responses to perceived risk and from direct predation mortality.

  1. Demographical history and palaeodistribution modelling show range shift towards Amazon Basin for a Neotropical tree species in the LGM.

    Science.gov (United States)

    Vitorino, Luciana Cristina; Lima-Ribeiro, Matheus S; Terribile, Levi Carina; Collevatti, Rosane G

    2016-10-13

    We studied the phylogeography and demographical history of Tabebuia serratifolia (Bignoniaceae) to understand the disjunct geographical distribution of South American seasonally dry tropical forests (SDTFs). We specifically tested if the multiple and isolated patches of SDTFs are current climatic relicts of a widespread and continuously distributed dry forest during the last glacial maximum (LGM), the so called South American dry forest refugia hypothesis, using ecological niche modelling (ENM) and statistical phylogeography. We sampled 235 individuals of T. serratifolia in 17 populations in Brazil and analysed the polymorphisms at three intergenic chloroplast regions and ITS nuclear ribosomal DNA. Coalescent analyses showed a demographical expansion at the last c. 130 ka (thousand years before present). Simulations and ENM also showed that the current spatial pattern of genetic diversity is most likely due to a scenario of range expansion and range shift towards the Amazon Basin during the colder and arid climatic conditions associated with the LGM, matching the expected for the South American dry forest refugia hypothesis, although contrasting to the Pleistocene Arc hypothesis. Populations in more stable areas or with higher suitability through time showed higher genetic diversity. Postglacial range shift towards the Southeast and Atlantic coast may have led to spatial genome assortment due to leading edge colonization as the species tracks suitable environments, leading to lower genetic diversity in populations at higher distance from the distribution centroid at 21 ka. Haplotype sharing or common ancestry among populations from Caatinga in Northeast Brazil, Atlantic Forest in Southeast and Cerrado biome and ENM evince the past connection among these biomes.

  2. Influence Of Demographic Factors And History Of Malaria With The Incidence Malaria In MORU PHC

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    Sudirman Manumpa

    2017-01-01

    Full Text Available Malaria morbidity in Moru health center, with parameter Annual Parasite Incident (API, amounted to 16.9% in 2014. This figure was still high when compared to the target of eliminating malaria in Indonesia about <1% in 2030. Incidence of malaria is more common in children aged 5 months - <12 years. This high rates of malaria leads to poverty, low level of learning achievement of children and in pregnant women causing low birth weight in babies and death. The purpose of this study was to analyze the factors that influence the incidence of tertian and Tropikana malaria or combined Tropikana and tertian (mix in Moru PHC in sub-district Alor Southwestern, Alor Regency.This study used a cross-sectional design, the population of study were all patients undergoing peripheral blood examination in Moru PHC’s laboratory from June to October 2015. The number of samples in this study was 173 respondents. The sampling technique was Simple Random Sampling. Instruments of data collection were a questionnaire and observation sheet.Results of the study by Chi-Square test showed that the factors influencing the incidence of malaria were socioeconomic status (sig 0,000, education level (sig 0.001. By using multivariate analysis with logistic regression test, results were obtained the age of 5 months - <12 value (sig 0.025 and socioeconomic status (sig 0,000 influencing the incidence of malaria.Variables that affect the incidence of malaria were demographic factors such as age, education level, socioeconomic status. It is advisable to harness swamp thus improving the economic status of society and build permanent house. Keywords: incidence malaria, demographic factors, history of malaria

  3. Population genetic structure and demographic history of Atrina pectinata based on mitochondrial DNA and microsatellite markers.

    Directory of Open Access Journals (Sweden)

    Dong-Xiu Xue

    Full Text Available The pen shell, Atrina pectinata, is one of the commercial bivalves in East Asia and thought to be recently affected by anthropogenic pressure (habitat destruction and/or fishing pressure. Information on its population genetic structure is crucial for the conservation of A. pectinata. Considering its long pelagic larval duration and iteroparity with high fecundity, the genetic structure for A. pectinata could be expected to be weak at a fine scale. However, the unusual oceanography in the coasts of China and Korea suggests potential for restricted dispersal of pelagic larvae and geographical differentiation. In addition, environmental changes associated with Pleistocene sea level fluctuations on the East China Sea continental shelf may also have strongly influenced historical population demography and genetic diversity of marine organisms. Here, partial sequences of the mitochondrial Cytochrome c oxidase subunit I (COI gene and seven microsatellite loci were used to estimate population genetic structure and demographic history of seven samples from Northern China coast and one sample from North Korea coast. Despite high levels of genetic diversity within samples, there was no genetic differentiation among samples from Northern China coast and low but significant genetic differentiation between some of the Chinese samples and the North Korean sample. A late Pleistocene population expansion, probably after the Last Glacial Maximum, was also demonstrated for A. pectinata samples. No recent genetic bottleneck was detected in any of the eight samples. We concluded that both historical recolonization (through population range expansion and demographic expansion in the late Pleistocene and current gene flow (through larval dispersal were responsible for the weak level of genetic structure detected in A. pectinata.

  4. Recent Demographic History and Present Fine-Scale Structure in the Northwest Atlantic Leatherback (Dermochelys coriacea) Turtle Population

    Science.gov (United States)

    Molfetti, Érica; Torres Vilaça, Sibelle; Georges, Jean-Yves; Plot, Virginie; Delcroix, Eric; Le Scao, Rozen; Lavergne, Anne; Barrioz, Sébastien; dos Santos, Fabrício Rodrigues; de Thoisy, Benoît

    2013-01-01

    The leatherback turtle Dermochelys coriacea is the most widely distributed sea turtle species in the world. It exhibits complex life traits: female homing and migration, migrations of juveniles and males that remain poorly known, and a strong climatic influence on resources, breeding success and sex-ratio. It is consequently challenging to understand population dynamics. Leatherbacks are critically endangered, yet the group from the Northwest Atlantic is currently considered to be under lower risk than other populations while hosting some of the largest rookeries. Here, we investigated the genetic diversity and the demographic history of contrasted rookeries from this group, namely two large nesting populations in French Guiana, and a smaller one in the French West Indies. We used 10 microsatellite loci, of which four are newly isolated, and mitochondrial DNA sequences of the control region and cytochrome b. Both mitochondrial and nuclear markers revealed that the Northwest Atlantic stock of leatherbacks derives from a single ancestral origin, but show current genetic structuration at the scale of nesting sites, with the maintenance of migrants amongst rookeries. Low nuclear genetic diversities are related to founder effects that followed consequent bottlenecks during the late Pleistocene/Holocene. Most probably in response to climatic oscillations, with a possible influence of early human hunting, female effective population sizes collapsed from 2 million to 200. Evidence of founder effects and high numbers of migrants make it possible to reconsider the population dynamics of the species, formerly considered as a metapopulation model: we propose a more relaxed island model, which we expect to be a key element in the currently observed recovering of populations. Although these Northwest Atlantic rookeries should be considered as a single evolutionary unit, we stress that local conservation efforts remain necessary since each nesting site hosts part of the genetic

  5. Genomic differentiation and demographic histories of Atlantic and Indo-Pacific yellowfin tuna (Thunnus albacares) populations.

    Science.gov (United States)

    Barth, J M I; Damerau, M; Matschiner, M; Jentoft, S; Hanel, R

    2017-04-13

    Recent developments in the field of genomics have provided new and powerful insights into population structure and dynamics that are essential for the conservation of biological diversity. As a commercially highly valuable species, the yellowfin tuna (Thunnus albacares) is intensely exploited throughout its distribution in tropical oceans around the world, and is currently classified as near threatened. However, conservation efforts for this species have so far been hampered by limited knowledge of its population structure, due to incongruent results of previous investigations. Here, we use whole-genome sequencing in concert with a draft genome assembly to decipher the global population structure of the yellowfin tuna, and to investigate its demographic history. We detect significant differentiation of Atlantic and Indo-Pacific yellowfin tuna populations as well as the possibility of a third diverged yellowfin tuna group in the Arabian Sea. We further observe evidence for past population expansion as well as asymmetric gene flow from the Indo-Pacific to the Atlantic. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  6. Phylogeographic analyses of the pampas cat (Leopardus colocola; Carnivora, Felidae) reveal a complex demographic history

    Science.gov (United States)

    da Silva Santos, Anelisie; Trigo, Tatiane Campos; de Oliveira, Tadeu Gomes; Silveira, Leandro

    2018-01-01

    Abstract The pampas cat is a small felid that occurs in open habitats throughout much of South America. Previous studies have revealed intriguing patterns of morphological differentiation and genetic structure among its populations, as well as molecular evidence for hybridization with the closely related L. tigrinus. Here we report phylogeographic analyses encompassing most of its distribution (focusing particularly on Brazilian specimens, which had been poorly sampled in previous studies), using a novel dataset comprising 2,143 bp of the mitogenome, along with previously reported mtDNA sequences. Our data revealed strong population strutucture and supported a west-to-east colonization process in this species’ history. We detected two population expansion events, one older (ca. 200 thousand years ago [kya]) in western South America and another more recent (ca. 60-50 kya) in eastern areas, coinciding with the expansion of savanna environments in Brazil. Analyses including L. tigrinus individuals bearing introgressed mtDNA from L. colocola showed a complete lack of shared haplotypes between species, indicating that their hybridization was ancient. Finally, we observed a close relationship between Brazilian/Uruguayan L. colocola haplotypes and those sampled in L. tigrinus, indicating that their hybridization was likely related to the demographic expansion of L. colocola into eastern South America. PMID:29668017

  7. Demographic histories, isolation and social factors as determinants of the genetic structure of Alpine linguistic groups.

    Science.gov (United States)

    Coia, Valentina; Capocasa, Marco; Anagnostou, Paolo; Pascali, Vincenzo; Scarnicci, Francesca; Boschi, Ilaria; Battaggia, Cinzia; Crivellaro, Federica; Ferri, Gianmarco; Alù, Milena; Brisighelli, Francesca; Busby, George B J; Capelli, Cristian; Maixner, Frank; Cipollini, Giovanna; Viazzo, Pier Paolo; Zink, Albert; Destro Bisol, Giovanni

    2013-01-01

    Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of "local ethnicity" on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet to be understood

  8. Demographic histories, isolation and social factors as determinants of the genetic structure of Alpine linguistic groups.

    Directory of Open Access Journals (Sweden)

    Valentina Coia

    Full Text Available Great European mountain ranges have acted as barriers to gene flow for resident populations since prehistory and have offered a place for the settlement of small, and sometimes culturally diverse, communities. Therefore, the human groups that have settled in these areas are worth exploring as an important potential source of diversity in the genetic structure of European populations. In this study, we present new high resolution data concerning Y chromosomal variation in three distinct Alpine ethno-linguistic groups, Italian, Ladin and German. Combining unpublished and literature data on Y chromosome and mitochondrial variation, we were able to detect different genetic patterns. In fact, within and among population diversity values observed vary across linguistic groups, with German and Italian speakers at the two extremes, and seem to reflect their different demographic histories. Using simulations we inferred that the joint effect of continued genetic isolation and reduced founding group size may explain the apportionment of genetic diversity observed in all groups. Extending the analysis to other continental populations, we observed that the genetic differentiation of Ladins and German speakers from Europeans is comparable or even greater to that observed for well known outliers like Sardinian and Basques. Finally, we found that in south Tyroleans, the social practice of Geschlossener Hof, a hereditary norm which might have favored male dispersal, coincides with a significant intra-group diversity for mtDNA but not for Y chromosome, a genetic pattern which is opposite to those expected among patrilocal populations. Together with previous evidence regarding the possible effects of "local ethnicity" on the genetic structure of German speakers that have settled in the eastern Italian Alps, this finding suggests that taking socio-cultural factors into account together with geographical variables and linguistic diversity may help unveil some yet

  9. American Military Veteran Entrepreneurs: A Comprehensive Profile of Demographic, Service History, and Psychosocial Characteristics.

    Science.gov (United States)

    Heinz, Adrienne J; Freeman, Michael A; Harpaz-Rotem, Ilan; Pietrzak, Robert H

    2017-01-01

    American military veterans are nearly twice as likely to be self-employed compared to non-veterans, and are majority owners in nine percent of all businesses nationwide. Despite their contribution to the broader economy and the potential for training programs to cultivate and foster successful self-employment and veteran-lead entrepreneurial ventures, research on veteran entrepreneurs remains limited. In order to gain a better understanding of the potential strengths and vulnerabilities of veteran entrepreneurs, the current study utilized data from a large, nationally representative sample to profile self-employed veterans (n=230) and compare them to veterans who work as employees (n=1,055) with respect to demographic, military service history, and psychosocial characteristics. Results indicated that self-employed veterans were older and more educated and more likely to utilize VA healthcare. Self-employed veterans were more likely to serve in Vietnam and to serve in the military for fewer years. No differences were noted in perceived military experience, level of combat exposure, or military branch served as a function of self-employment. Although reporting more lifetime traumas, self-employed veterans did not experience higher rates of current or lifetime psychopathology or lower perceived quality of life. Potential protective resilience-promoting factors may be associated with the higher levels of openness, extraversion, optimism, achievement-orientation (purpose in life), and greater need for autonomy and professional development observed among self-employed veterans. Moreover, self-employed veterans demonstrated higher levels of gratitude, community integration, and altruistic service to others. Findings have potential to inform human resources management strategies and vocational training and reintegration initiatives for veterans.

  10. American Military Veteran Entrepreneurs: A Comprehensive Profile of Demographic, Service History, and Psychosocial Characteristics

    Science.gov (United States)

    Heinz, Adrienne J.; Freeman, Michael A.; Harpaz-Rotem, Ilan; Pietrzak, Robert H.

    2017-01-01

    American military veterans are nearly twice as likely to be self-employed compared to non-veterans, and are majority owners in nine percent of all businesses nationwide. Despite their contribution to the broader economy and the potential for training programs to cultivate and foster successful self-employment and veteran-lead entrepreneurial ventures, research on veteran entrepreneurs remains limited. In order to gain a better understanding of the potential strengths and vulnerabilities of veteran entrepreneurs, the current study utilized data from a large, nationally representative sample to profile self-employed veterans (n=230) and compare them to veterans who work as employees (n=1,055) with respect to demographic, military service history, and psychosocial characteristics. Results indicated that self-employed veterans were older and more educated and more likely to utilize VA healthcare. Self-employed veterans were more likely to serve in Vietnam and to serve in the military for fewer years. No differences were noted in perceived military experience, level of combat exposure, or military branch served as a function of self-employment. Although reporting more lifetime traumas, self-employed veterans did not experience higher rates of current or lifetime psychopathology or lower perceived quality of life. Potential protective resilience-promoting factors may be associated with the higher levels of openness, extraversion, optimism, achievement-orientation (purpose in life), and greater need for autonomy and professional development observed among self-employed veterans. Moreover, self-employed veterans demonstrated higher levels of gratitude, community integration, and altruistic service to others. Findings have potential to inform human resources management strategies and vocational training and reintegration initiatives for veterans. PMID:29290645

  11. Demographic development of ukrainian rural area: lessons of history, modern socio-economic threats

    Directory of Open Access Journals (Sweden)

    D.P. Melnychuk

    2016-06-01

    Full Text Available The article is devoted to urgent problems of demographic development of rural areas, their impact on socioeconomic processes at all levels of the national economic system. The content of demographic and economic antonyms of «demographic development» and «demographic catastrophe» has been characterized. The article analyzes the historical background of demographic change in rural areas, their socio-economic consequences. It’s reasonably concluded that the economic development of Ukraine requires urgent settlement of the negative socio-demographic trends that are characteristic for a Ukrainian village. Nowadays, these trends are of a destructive nature. They lead to a protracted crisis of agricultural production which is very difficult to overcome solely with the tools of technical and technological modernization. This will complicate the food security of the state for many years; lower the level and quality of life of the population, lead to greater territorial disparities and degradation of rural areas and the marginalization of residents of Ukrainian villages.

  12. Demographic histories of adaptively diverged riparian and non-riparian species of Ainsliaea (Asteraceae) inferred from coalescent analyses using multiple nuclear loci.

    Science.gov (United States)

    Mitsui, Yuki; Setoguchi, Hiroaki

    2012-12-28

    /non-riparian lineages showed contrasting patterns of gene flow and genetic differentiation, implying that each lineage showed different degrees of reproductive isolation and that they had experienced unique evolutionary and demographic histories in the process of adaptive divergence.

  13. Genetic diversity, outcrossing rate, and demographic history along a climatic gradient in the ruderal plant Ruellia nudiflora (Acanthaceae)

    OpenAIRE

    Vargas-Mendoza, Carlos F.; Ortegón-Campos, Ilka; Marrufo-Zapata, Denis; Herrera, Carlos M.; Parra-Tabla, Víctor

    2015-01-01

    Ruellia nudiflora has shown a high potential to easily invade disturbed areas. Outcrossing rate and genetic structure and diversity in this species were examined along a climatic gradient in the Yucatán Peninsula (Mexico) in order to understand the effects of environmental heterogeneity - isolation by environment (IBE) - as well as correlation in herkogamy on genetic structure, diversity, and demographic history in this species. Nine populations were sampled along a temperature-precipitation ...

  14. Urbanization shapes the demographic history of a native rodent (the white-footed mouse, Peromyscus leucopus) in New York City

    OpenAIRE

    Harris, Stephen E.; Xue, Alexander T.; Alvarado-Serrano, Diego; Boehm, Joel T.; Joseph, Tyler; Hickerson, Michael J.; Munshi-South, Jason

    2016-01-01

    How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice, Peromyscus leucopus, in the New York City (NYC) metropolitan area using coalescent-based simulations to infer demographic history from the site-frequency spectrum. We assigned individuals to evolutionary clusters and then inferred recent divergence times, population size changes and migration using genome-wide single nucle...

  15. Effects of geological changes and climatic fluctuations on the demographic histories and low genetic diversity of Squaliobarbus curriculus in Yellow River.

    Science.gov (United States)

    Zhou, Wei; Song, Na; Wang, Jun; Gao, Tianxiang

    2016-09-15

    The 104 samples of Squaliobarbus curriculus were collected from four localities in Yellow River and one region in Yangtze River. Analyses of the first hypervariable region of mitochondrial DNA control region of 555bp revealed only 15 polymorphism sites and defined 19 haplotypes. Low-to-moderate levels of haplotype diversity and low nucleotide diversity were observed in Yellow River populations (h=0.2529-0.7510, π=0.0712%-0.2197%). In contrast, Poyang Lake population showed high haplotype diversity and lower-middle nucleotide diversity (h=0.9636, π=0.5317%). Low genetic differentiation was estimated among Yellow River populations and significant level of genetic structure was detected between two rivers. Population genetic structure between two rivers was believed to be connected with geographical barriers and paleoclimatic events. The demographic history of S. curriculus in Yellow River examined by neutrality tests, mismatch distribution analysis, and Bayesian skyline analysis suggested a sudden and spatial population expansion dating to the Holocene. Climatic warming and changes of Yellow River course may have important effects on demographic facet of S. curriculus history. The same signal was also obtained on Poyang Lake population in late Pleistocene during the last interglacial period. During the period, the pronounced climatic change and the water system variation of PYL may have an important influence on the population. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Genomic Analyses Reveal Demographic History and Temperate Adaptation of the Newly Discovered Honey Bee Subspecies Apis mellifera sinisxinyuan n. ssp.

    Science.gov (United States)

    Chen, Chao; Liu, Zhiguang; Pan, Qi; Chen, Xiao; Wang, Huihua; Guo, Haikun; Liu, Shidong; Lu, Hongfeng; Tian, Shilin; Li, Ruiqiang; Shi, Wei

    2016-05-01

    Studying the genetic signatures of climate-driven selection can produce insights into local adaptation and the potential impacts of climate change on populations. The honey bee (Apis mellifera) is an interesting species to study local adaptation because it originated in tropical/subtropical climatic regions and subsequently spread into temperate regions. However, little is known about the genetic basis of its adaptation to temperate climates. Here, we resequenced the whole genomes of ten individual bees from a newly discovered population in temperate China and downloaded resequenced data from 35 individuals from other populations. We found that the new population is an undescribed subspecies in the M-lineage of A. mellifera (Apis mellifera sinisxinyuan). Analyses of population history show that long-term global temperature has strongly influenced the demographic history of A. m. sinisxinyuan and its divergence from other subspecies. Further analyses comparing temperate and tropical populations identified several candidate genes related to fat body and the Hippo signaling pathway that are potentially involved in adaptation to temperate climates. Our results provide insights into the demographic history of the newly discovered A. m. sinisxinyuan, as well as the genetic basis of adaptation of A. mellifera to temperate climates at the genomic level. These findings will facilitate the selective breeding of A. mellifera to improve the survival of overwintering colonies. © The Author 2016. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  17. Region-wide and ecotype-specific differences in demographic histories of threespine stickleback populations, estimated from whole genome sequences.

    Science.gov (United States)

    Liu, Shenglin; Hansen, Michael M; Jacobsen, Magnus W

    2016-10-01

    We analysed 81 whole genome sequences of threespine sticklebacks from Pacific North America, Greenland and Northern Europe, representing 16 populations. Principal component analysis of nuclear SNPs grouped populations according to geographical location, with Pacific populations being more divergent from each other relative to European and Greenlandic populations. Analysis of mitogenome sequences showed Northern European populations to represent a single phylogeographical lineage, whereas Greenlandic and particularly Pacific populations showed admixture between lineages. We estimated demographic history using a genomewide coalescence with recombination approach. The Pacific populations showed gradual population expansion starting >100 Kya, possibly reflecting persistence in cryptic refuges near the present distributional range, although we do not rule out possible influence of ancient admixture. Sharp population declines ca. 14-15 Kya were suggested to reflect founding of freshwater populations by marine ancestors. In Greenland and Northern Europe, demographic expansion started ca. 20-25 Kya coinciding with the end of the Last Glacial Maximum. In both regions, marine and freshwater populations started to show different demographic trajectories ca. 8-9 Kya, suggesting that this was the time of recolonization. In Northern Europe, this estimate was surprisingly late, but found support in subfossil evidence for presence of several freshwater fish species but not sticklebacks 12 Kya. The results demonstrate distinctly different demographic histories across geographical regions with potential consequences for adaptive processes. They also provide empirical support for previous assumptions about freshwater populations being founded independently from large, coherent marine populations, a key element in the Transporter Hypothesis invoked to explain the widespread occurrence of parallel evolution across freshwater stickleback populations. © 2016 John Wiley & Sons Ltd.

  18. Inferring the demographic history of an oligophagous grasshopper: Effects of climatic niche stability and host-plant distribution.

    Science.gov (United States)

    Noguerales, Víctor; Cordero, Pedro J; Ortego, Joaquín

    2018-01-01

    Understanding the consequences of past environmental changes on the abiotic and biotic components of the landscape and deciphering their impacts on the demographic trajectories of species is a major issue in evolutionary biogeography. In this study, we combine nuclear and mitochondrial genetic data to study the phylogeographical structure and lineage-specific demographic histories of the scrub-legume grasshopper (Chorthippus binotatus binotatus), a montane taxon distributed in the Iberian Peninsula and France that exclusively feeds on certain scrub-legume species. Genetic data and paleo-distribution modelling indicate the presence of four main lineages that seem to have diverged in allopatry and long-term persisted in Iberian and French refugia since the Mid Pleistocene. Comparisons of different demographic hypotheses in an Approximate Bayesian Computation (ABC) framework supported a population bottleneck in the northwestern French clade and paleo-distribution modelling indicate that the populations of this lineage have experienced more severe environmental fluctuations during the last 21 000 years than those from the Iberian Peninsula. Accordingly, we found that nuclear genetic diversity of the populations of scrub-legume grasshopper is positively associated with local stability of suitable habitats defined by both Pleistocene climate changes and historical distributional shifts of host-plant species. Overall, our study highlights the importance of integrating the potential effects of abiotic (i.e. climate and geography) and biotic components (i.e. inter-specific interactions) into the study of the evolutionary and demographic history of specialist taxa with narrow ecological requirements. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Genetic structure and demographic history of Colletotrichum gloeosporioides sensu lato and C. truncatum isolates from Trinidad and Mexico.

    Science.gov (United States)

    Rampersad, Sephra N; Perez-Brito, Daisy; Torres-Calzada, Claudia; Tapia-Tussell, Raul; Carrington, Christine V F

    2013-06-22

    C. gloeosporioides sensu lato is one of the most economically important post-harvest diseases affecting papaya production worldwide. There is currently no information concerning the genetic structure or demographic history of this pathogen in any of the affected countries. Knowledge of molecular demographic parameters for different populations will improve our understanding of the biogeographic history as well as the evolutionary and adaptive potential of these pathogens. In this study, sequence data for ACT, GPDH, β-TUB and ITS gene regions were analyzed for C. gloeosporioides sensu lato and C. truncatum isolates infecting papaya in Trinidad and Mexico in order to determine the genetic structure and demographic history of these populations. The data indicated that Mexico is the ancestral C. gloeosporioides sensu lato population with asymmetrical migration to Trinidad. Mexico also had the larger effective population size but, both Mexico and Trinidad populations exhibited population expansion. Mexico also had greater nucleotide diversity and high levels of diversity for each gene. There was significant sub-division of the Trinidad and Mexico populations and low levels of genetic divergence among populations for three of the four gene regions; β-TUB was shown to be under positive selection. There were also dissimilar haplotype characteristics for both populations. Mutation may play a role in shaping the population structure of C. gloeosporioides sensu lato isolates from Trinidad and from Mexico, especially with respect to the ACT and GPDH gene regions. There was no evidence of gene flow between the C. truncatum populations and it is possible that the Mexico and Trinidad populations emerged independently of each other. The study revealed relevant information based on the genetic structure as well as the demographic history of two fungal pathogens infecting papaya, C. gloeosporioides sensu lato and C. truncatum, in Trinidad and Mexico. Understanding the genetic

  20. Impact of Quaternary climatic changes and interspecific competition on the demographic history of a highly mobile generalist carnivore, the coyote.

    Science.gov (United States)

    Koblmüller, Stephan; Wayne, Robert K; Leonard, Jennifer A

    2012-08-23

    Recurrent cycles of climatic change during the Quaternary period have dramatically affected the population genetic structure of many species. We reconstruct the recent demographic history of the coyote (Canis latrans) through the use of Bayesian techniques to examine the effects of Late Quaternary climatic perturbations on the genetic structure of a highly mobile generalist species. Our analysis reveals a lack of phylogeographic structure throughout the range but past population size changes correlated with climatic changes. We conclude that even generalist carnivorous species are very susceptible to environmental changes associated with climatic perturbations. This effect may be enhanced in coyotes by interspecific competition with larger carnivores.

  1. Museum DNA reveals the demographic history of the endangered Seychelles warbler.

    Science.gov (United States)

    Spurgin, Lewis G; Wright, David J; van der Velde, Marco; Collar, Nigel J; Komdeur, Jan; Burke, Terry; Richardson, David S

    2014-11-01

    The importance of evolutionary conservation - how understanding evolutionary forces can help guide conservation decisions - is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) - an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral N e of several thousands falling to Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation.

  2. Linkage disequilibrium and demographic history of the isolated population of the Faroe Islands

    DEFF Research Database (Denmark)

    Jorgensen, Tove H; Degn, Birte; Wang, August G

    2002-01-01

    The isolated population of the Faroe Islands has a history of recent expansion after being limited to a small size for centuries. Such an isolated population may be ideal for linkage disequilibrium mapping of disease genes if linkage disequilibrium (LD) extends over large regions. Analyses of 18 ...

  3. Urbanization shapes the demographic history of a native rodent (the white-footed mouse, Peromyscus leucopus) in New York City.

    Science.gov (United States)

    Harris, Stephen E; Xue, Alexander T; Alvarado-Serrano, Diego; Boehm, Joel T; Joseph, Tyler; Hickerson, Michael J; Munshi-South, Jason

    2016-04-01

    How urbanization shapes population genomic diversity and evolution of urban wildlife is largely unexplored. We investigated the impact of urbanization on white-footed mice,Peromyscus leucopus,in the New York City (NYC) metropolitan area using coalescent-based simulations to infer demographic history from the site-frequency spectrum. We assigned individuals to evolutionary clusters and then inferred recent divergence times, population size changes and migration using genome-wide single nucleotide polymorphisms genotyped in 23 populations sampled along an urban-to-rural gradient. Both prehistoric climatic events and recent urbanization impacted these populations. Our modelling indicates that post-glacial sea-level rise led to isolation of mainland and Long Island populations. These models also indicate that several urban parks represent recently isolated P. leucopus populations, and the estimated divergence times for these populations are consistent with the history of urbanization in NYC. © 2016 The Author(s).

  4. Demographic Structure and Evolutionary History of Drosophila ornatifrons (Diptera, Drosophilidae) from Atlantic Forest of Southern Brazil.

    Science.gov (United States)

    Gustani, Emanuele C; Oliveira, Ana Paula F; Santos, Mateus H; Machado, Luciana P B; Mateus, Rogério P

    2015-04-01

    Drosoph1la ornatifrons of the guarani group (Diptera: Drosophilidae) is found mainly in humid areas of the Atlantic Forest biome, especially in the southern region of Brazil. Historical and contemporary fragmentation events influenced species diversity and distribution in this biome, although the role of paleoclimatic and paleogeographic events remain to be verified. The objective of the present study was to evaluate the demographic structure of D. ornatifrons from collection sites that are remnants of Atlantic Forest in southern Brazil, in order to contribute to the understanding of the processes that affected the patterns of genetic variability in this species. To achieve this goal, we sequenced 51 individuals from nine localities and 64 individuals from six localities for the mitochondrial genes Cytochrome Oxidase I and II, respectively. Our results indicate that D. ornatifrons may have experienced a demographic expansion event from the southernmost locations of its distribution, most likely from those located next to the coast and in fragments of Atlantic Forest inserted in the Pampa biome (South 2 group), towards the interior (South 1 group). This expansion probably started after the last glacial maximum, between 20,000 and 18,000 years ago, and was intensified near the Pleistocene-Holocene transition, around 12,000 years ago, when temperature started to rise. In this work we discuss how the haplotypes found barriers to gene flow and dispersal, influenced by the biogeographic pattern of Atlantic Forest.

  5. Life history and demographic drivers of reservoir competence for three tick-borne zoonotic pathogens.

    Directory of Open Access Journals (Sweden)

    Richard S Ostfeld

    Full Text Available Animal and plant species differ dramatically in their quality as hosts for multi-host pathogens, but the causes of this variation are poorly understood. A group of small mammals, including small rodents and shrews, are among the most competent natural reservoirs for three tick-borne zoonotic pathogens, Borrelia burgdorferi, Babesia microti, and Anaplasma phagocytophilum, in eastern North America. For a group of nine commonly-infected mammals spanning >2 orders of magnitude in body mass, we asked whether life history features or surrogates for (unknown encounter rates with ticks, predicted reservoir competence for each pathogen. Life history features associated with a fast pace of life generally were positively correlated with reservoir competence. However, a model comparison approach revealed that host population density, as a proxy for encounter rates between hosts and pathogens, generally received more support than did life history features. The specific life history features and the importance of host population density differed somewhat between the different pathogens. We interpret these results as supporting two alternative but non-exclusive hypotheses for why ecologically widespread, synanthropic species are often the most competent reservoirs for multi-host pathogens. First, multi-host pathogens might adapt to those hosts they are most likely to experience, which are likely to be the most abundant and/or frequently bitten by tick vectors. Second, species with fast life histories might allocate less to certain immune defenses, which could increase their reservoir competence. Results suggest that of the host species that might potentially be exposed, those with comparatively high population densities, small bodies, and fast pace of life will often be keystone reservoirs that should be targeted for surveillance or management.

  6. Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

    KAUST Repository

    Salles, Océane C.

    2016-07-26

    The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies establishing the demographic and life-history consequences of occupying different reef substrata are rare and no studies have monitored individuals in situ over their lifetime and determined the fate of their offspring. Here, we documented a quasi-turnover and local reproductive success for an entire population of orange clownfish (Amphiprion percula) from Kimbe Island, Papua New Guinea, by taking bi-annual samples of DNA over a 10-yr period (2003–2013). We compared demographic and life-history traits of individuals living on two host anemone species, Heteractis magnifica and Stichodactyla gigantea, including female size, adult continued presence (a proxy for relative longevity range), early post-settlement growth, the number of eggs per clutch and ‘local’ reproductive success (defined for each adult as the number of offspring returning to the natal population). Our results indicate that while the relative longevity of adults was similar on both host anemone species, females living in H. magnifica were larger than females in S. gigantea. However, despite females growing larger and producing more eggs on H. magnifica, we found that local reproductive success was significantly higher for clownfish living in S. gigantea. Life-history traits also exhibited local spatial variation, with higher local reproductive success recorded for adults living on S. gigantea on the eastern side of the island. Our findings support a ‘silver-spoon’ hypothesis that predicts individuals that are fortunate enough to recruit into good habitat and location will be rewarded with higher long-term reproductive success and will make a disproportionate contribution to population renewal. © 2016 Springer-Verlag Berlin Heidelberg

  7. Life-history stages of the jellyfish Aurelia aurita - towards a demographic understanding of jellyfish blooms

    DEFF Research Database (Denmark)

    Goldstein, Josephine

    2017-01-01

    Jellyfish blooms are conspicuous demographic events that have received increasing attention by the public and the scientific community over the last decades due to their negative impact on fisheries, tourism and other human industries. Several aspects of the complex life cycles of the jellyfish......, including frequent mass occurrence of A. aurita medusae in temperate Danish waters. The present novel data show for instance, that jellyfish blooms of A. aurita are strongly affected by food availability and corresponding shifts between asexually reproducing benthic polyps and sexually reproducing pelagic...... medusae, which might be highly representative for the majority of bloom-forming jellyfish species. Findings further indicate that seasonal shrinkage and subsequent disappearance of A. aurita medusae is rather driven by food limitation than by a trade-off between sexual reproduction and metabolic...

  8. Inferring the demographic history from DNA sequences: An importance sampling approach based on non-homogeneous processes.

    Science.gov (United States)

    Ait Kaci Azzou, S; Larribe, F; Froda, S

    2016-10-01

    In Ait Kaci Azzou et al. (2015) we introduced an Importance Sampling (IS) approach for estimating the demographic history of a sample of DNA sequences, the skywis plot. More precisely, we proposed a new nonparametric estimate of a population size that changes over time. We showed on simulated data that the skywis plot can work well in typical situations where the effective population size does not undergo very steep changes. In this paper, we introduce an iterative procedure which extends the previous method and gives good estimates under such rapid variations. In the iterative calibrated skywis plot we approximate the effective population size by a piecewise constant function, whose values are re-estimated at each step. These piecewise constant functions are used to generate the waiting times of non homogeneous Poisson processes related to a coalescent process with mutation under a variable population size model. Moreover, the present IS procedure is based on a modified version of the Stephens and Donnelly (2000) proposal distribution. Finally, we apply the iterative calibrated skywis plot method to a simulated data set from a rapidly expanding exponential model, and we show that the method based on this new IS strategy correctly reconstructs the demographic history. Copyright © 2016. Published by Elsevier Inc.

  9. Comparative phylogeography and demographic history of the wood lemming (Myopus schisticolor): implications for late Quaternary history of the taiga species in Eurasia.

    Science.gov (United States)

    Fedorov, V B; Goropashnaya, A V; Boeskorov, G G; Cook, J A

    2008-01-01

    The association between demographic history, genealogy and geographical distribution of mitochondrial DNA cytochrome b haplotypes was studied in the wood lemming (Myopus schisticolor), a species that is closely associated with the boreal forest of the Eurasian taiga zone from Scandinavia to the Pacific coast. Except for a major phylogeographic discontinuity (0.9% nucleotide divergence) in southeastern Siberia, only shallow regional genetic structure was detected across northern Eurasia. Genetic signs of demographic expansions imply that successive range contractions and expansions on different spatial scales represented the primary historical events that shaped geographical patterns of genetic variation. Comparison of phylogeographic structure across a taxonomically diverse array of other species that are ecologically associated with the taiga forest revealed similar patterns and identified two general aspects. First, the major south-north phylogeographic discontinuity observed in five out of six species studied in southeastern Siberia and the Far East implies vicariant separation in two different refugial areas. The limited distribution range of the southeastern lineages provides no evidence of the importance of the putative southeastern refugial area for postglacial colonization of northern Eurasia by boreal forest species. Second, the lack of phylogeographic structure associated with significant reciprocal monophyly and genetic signatures of demographic expansion in all nine boreal forest animal species studied to date across most of northern Eurasia imply contraction of each species to a single refugial area during the late Pleistocene followed by range expansion on a continental scale. Similar phylogeographic patterns observed in this taxonomically diverse set of organisms with different life histories and dispersal potentials reflect the historical dynamics of their shared environment, the taiga forest in northern Eurasia.

  10. Genetic structure and demographic history of brown trout ( Salmo trutta ) populations from the southern Balkans

    DEFF Research Database (Denmark)

    Apostolidis, A.P.; Madeira, M.J.; Hansen, Michael Møller

    2008-01-01

    1. The present study was designed to characterize the genetic structure of brown trout (Salmo trutta) populations from the southern Balkans and to assess the spread of non-native strains and their introgression into native trout gene pools. We analysed polymorphism at nine microsatellite loci...... in seven supposedly non-admixed and three stocked brown trout populations. 2. The analyses confirmed the absence of immigration and extraordinarily strong genetic differentiation among the seven non-introgressed populations in parallel with low levels of intrapopulation genetic variability. In contrast...

  11. Inferring the demographic history of African farmers and pygmy hunter-gatherers using a multilocus resequencing data set.

    Directory of Open Access Journals (Sweden)

    Etienne Patin

    2009-04-01

    Full Text Available The transition from hunting and gathering to farming involved a major cultural innovation that has spread rapidly over most of the globe in the last ten millennia. In sub-Saharan Africa, hunter-gatherers have begun to shift toward an agriculture-based lifestyle over the last 5,000 years. Only a few populations still base their mode of subsistence on hunting and gathering. The Pygmies are considered to be the largest group of mobile hunter-gatherers of Africa. They dwell in equatorial rainforests and are characterized by their short mean stature. However, little is known about the chronology of the demographic events-size changes, population splits, and gene flow--ultimately giving rise to contemporary Pygmy (Western and Eastern groups and neighboring agricultural populations. We studied the branching history of Pygmy hunter-gatherers and agricultural populations from Africa and estimated separation times and gene flow between these populations. We resequenced 24 independent noncoding regions across the genome, corresponding to a total of approximately 33 kb per individual, in 236 samples from seven Pygmy and five agricultural populations dispersed over the African continent. We used simulation-based inference to identify the historical model best fitting our data. The model identified included the early divergence of the ancestors of Pygmy hunter-gatherers and farming populations approximately 60,000 years ago, followed by a split of the Pygmies' ancestors into the Western and Eastern Pygmy groups approximately 20,000 years ago. Our findings increase knowledge of the history of the peopling of the African continent in a region lacking archaeological data. An appreciation of the demographic and adaptive history of African populations with different modes of subsistence should improve our understanding of the influence of human lifestyles on genome diversity.

  12. Multiple Sclerosis and Several Demographic Characteristics, Family History of MS, and Month of Birth: A Case-Control Study

    Directory of Open Access Journals (Sweden)

    Bagheri

    2015-09-01

    Full Text Available Background Several factors have been reported as risk factors for multiple sclerosis (MS; however, the main causes of the disease are still unknown. A geographical area with a low MS incidence is Ahvaz, Iran. Objectives The objective of this study was to evaluate the association of several demographic characteristics, family history, and birth month with MS in Ahvaz. Patients and Methods This was a case-control study including 155 MS cases and 155 controls matched for age, sex, and residential status. The participants were selected randomly, using a systematic method, from the MS patients referred to the MS Society of Khuzestan (Iran. The data collection tool was a standardized questionnaire designed by the authors to assess demographic characteristics. Data were analyzed using descriptive statistics including mean, frequency, and standard deviation and inferential statistical tests including χ2, Fisher’s exact test, and logistic regression using SPSS version 19. Results In both cases and controls, no significant associations were found between Arab ethnicity and incidence of MS, marital status and risk of MS in Ahvaz, or more than 15-year residency in Ahvaz, birth in Khuzestan, and month of birth and the risk of MS (P > 0.05. However, there was a marginally significant association between living from birth to age 15 years in Ahvaz and MS (P = 0.05. Furthermore, there was an association between a family history of MS and the risk of MS in Ahvaz (P = 0.02, which was significant in univariate logistic regression (P = 0.006. Conclusions The findings suggested that according to the ecological conditions of Ahvaz, a family history of MS may increase the risk of developing MS.

  13. Nautilus pompilius life history and demographics at the Osprey Reef Seamount, Coral Sea, Australia.

    Directory of Open Access Journals (Sweden)

    Andrew J Dunstan

    Full Text Available Nautiloids are the subject of speculation as to their threatened status arising from the impacts of targeted fishing for the ornamental shell market. Life history knowledge is essential to understand the susceptibility of this group to overfishing and to the instigation of management frameworks. This study provides a comprehensive insight into the life of Nautilus in the wild. At Osprey Reef from 1998-2008, trapping for Nautilus was conducted on 354 occasions, with 2460 individuals of one species, Nautilus pompilius, captured and 247 individuals recaptured. Baited remote underwater video systems (BRUVS were deployed on 15 occasions and six remotely operated vehicle (ROV dives from 100-800 m were conducted to record Nautilus presence and behavior. Maturity, sex and size data were recorded, while measurements of recaptured individuals allowed estimation of growth rates to maturity, and longevity beyond maturity. We found sexual dimorphism in size at maturity (males: 131.9±SD = 2.6 mm; females: 118.9±7.5 mm shell diameter in a population dominated by mature individuals (58%. Mean growth rates of 15 immature recaptured animals were 0.061±0.023 mm day(-1 resulting in an estimate of around 15.5 years to maturation. Recaptures of mature animals after five years provide evidence of a lifespan exceeding 20 years. Juvenile Nautilus pompilius feeding behavior was recorded for the first time within the same depth range (200-610 m as adults. Our results provide strong evidence of a K-selected life history for Nautilus from a detailed study of a 'closed' wild population. In conjunction with population size and density estimates established for the Osprey Reef Nautilus, this work allows calculations for sustainable catch and provides mechanisms to extrapolate these findings to other extant nautiloid populations (Nautilus and Allonautilus spp. throughout the Indo-Pacific.

  14. Contrasting population-level responses to Pleistocene climatic oscillations in an alpine bat revealed by complete mitochondrial genomes and evolutionary history inference

    DEFF Research Database (Denmark)

    Alberdi, Antton; Gilbert, M. Thomas P; Razgour, Orly

    2015-01-01

    Aim: We used an integrative approach to reconstruct the evolutionary history of the alpine long-eared bat, Plecotus macrobullaris, to test whether the variable effects of Pleistocene climatic oscillations across geographical regions led to contrasting population-level demographic histories within...... a single species. Location: The Western Palaearctic. Methods: We sequenced the complete mitochondrial genomes of 57 individuals from across the distribution of the species. The analysis integrated ecological niche modelling (ENM), approximate Bayesian computation (ABC), measures of genetic diversity...... and Bayesian phylogenetic methods. Results: We identified two deep lineages: a western lineage, restricted to the Pyrenees and the Alps, and an eastern lineage, which expanded across the mountain ranges east of the Dinarides (Croatia). ENM projections of past conditions predicted that climatic suitability...

  15. Demographic history of Canary Islands male gene-pool: replacement of native lineages by European

    Directory of Open Access Journals (Sweden)

    Amorim António

    2009-08-01

    Full Text Available Abstract Background The origin and prevalence of the prehispanic settlers of the Canary Islands has attracted great multidisciplinary interest. However, direct ancient DNA genetic studies on indigenous and historical 17th–18th century remains, using mitochondrial DNA as a female marker, have only recently been possible. In the present work, the analysis of Y-chromosome polymorphisms in the same samples, has shed light on the way the European colonization affected male and female Canary Island indigenous genetic pools, from the conquest to present-day times. Results Autochthonous (E-M81 and prominent (E-M78 and J-M267 Berber Y-chromosome lineages were detected in the indigenous remains, confirming a North West African origin for their ancestors which confirms previous mitochondrial DNA results. However, in contrast with their female lineages, which have survived in the present-day population since the conquest with only a moderate decline, the male indigenous lineages have dropped constantly being substituted by European lineages. Male and female sub-Saharan African genetic inputs were also detected in the Canary population, but their frequencies were higher during the 17th–18th centuries than today. Conclusion The European colonization of the Canary Islands introduced a strong sex-biased change in the indigenous population in such a way that indigenous female lineages survived in the extant population in a significantly higher proportion than their male counterparts.

  16. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs.

    Directory of Open Access Journals (Sweden)

    Sara Fratini

    Full Text Available The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima's D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves.

  17. Demographic History and Reproductive Output Correlates with Intraspecific Genetic Variation in Seven Species of Indo-Pacific Mangrove Crabs.

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2016-01-01

    The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima's D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves.

  18. Tropical rainforests that persisted: inferences from the Quaternary demographic history of eight tree species in the Guiana shield.

    Science.gov (United States)

    Barthe, Stéphanie; Binelli, Giorgio; Hérault, Bruno; Scotti-Saintagne, Caroline; Sabatier, Daniel; Scotti, Ivan

    2017-02-01

    How Quaternary climatic and geological disturbances influenced the composition of Neotropical forests is hotly debated. Rainfall and temperature changes during and/or immediately after the last glacial maximum (LGM) are thought to have strongly affected the geographical distribution and local abundance of tree species. The paucity of the fossil records in Neotropical forests prevents a direct reconstruction of such processes. To describe community-level historical trends in forest composition, we turned therefore to inferential methods based on the reconstruction of past demographic changes. In particular, we modelled the history of rainforests in the eastern Guiana Shield over a timescale of several thousand generations, through the application of approximate Bayesian computation and maximum-likelihood methods to diversity data at nuclear and chloroplast loci in eight species or subspecies of rainforest trees. Depending on the species and on the method applied, we detected population contraction, expansion or stability, with a general trend in favour of stability or expansion, with changes presumably having occurred during or after the LGM. These findings suggest that Guiana Shield rainforests have globally persisted, while expanding, through the Quaternary, but that different species have experienced different demographic events, with a trend towards the increase in frequency of light-demanding, disturbance-associated species. © 2016 John Wiley & Sons Ltd.

  19. Contemporary genetic structure and postglacial demographic history of the black scorpionfish, Scorpaena porcus, in the Mediterranean and the Black Seas.

    Science.gov (United States)

    Boissin, E; Micu, D; Janczyszyn-Le Goff, M; Neglia, V; Bat, L; Todorova, V; Panayotova, M; Kruschel, C; Macic, V; Milchakova, N; Keskin, Ç; Anastasopoulou, A; Nasto, I; Zane, L; Planes, S

    2016-05-01

    Understanding the distribution of genetic diversity in the light of past demographic events linked with climatic shifts will help to forecast evolutionary trajectories of ecosystems within the current context of climate change. In this study, mitochondrial sequences and microsatellite loci were analysed using traditional population genetic approaches together with Bayesian dating and the more recent approximate Bayesian computation scenario testing. The genetic structure and demographic history of a commercial fish, the black scorpionfish, Scorpaena porcus, was investigated throughout the Mediterranean and Black Seas. The results suggest that the species recently underwent population expansions, in both seas, likely concomitant with the warming period following the Last Glacial Maximum, 20 000 years ago. A weak contemporaneous genetic differentiation was identified between the Black Sea and the Mediterranean Sea. However, the genetic diversity was similar for populations of the two seas, suggesting a high number of colonizers entered the Black Sea during the interglacial period and/or the presence of a refugial population in the Black Sea during the glacial period. Finally, within seas, an east/west genetic differentiation in the Adriatic seems to prevail, whereas the Black Sea does not show any structured spatial genetic pattern of its population. Overall, these results suggest that the Black Sea is not that isolated from the Mediterranean, and both seas revealed similar evolutionary patterns related to climate change and changes in sea level. © 2016 John Wiley & Sons Ltd.

  20. Genetic Pattern and Demographic History of Salminus brasiliensis: Population Expansion in the Pantanal Region during the Pleistocene

    Directory of Open Access Journals (Sweden)

    Lívia A. de Carvalho Mondin

    2018-01-01

    Full Text Available Pleistocene climate changes were major historical events that impacted South American biodiversity. Although the effects of such changes are well-documented for several biomes, it is poorly known how these climate shifts affected the biodiversity of the Pantanal floodplain. Fish are one of the most diverse groups in the Pantanal floodplains and can be taken as a suitable biological model for reconstructing paleoenvironmental scenarios. To identify the effects of Pleistocene climate changes on Pantanal’s ichthyofauna, we used genetic data from multiple populations of a top-predator long-distance migratory fish, Salminus brasiliensis. We specifically investigated whether Pleistocene climate changes affected the demography of this species. If this was the case, we expected to find changes in population size over time. Thus, we assessed the genetic diversity of S. brasiliensis to trace the demographic history of nine populations from the Upper Paraguay basin, which includes the Pantanal floodplain, that form a single genetic group, employing approximate Bayesian computation (ABC to test five scenarios: constant population, old expansion, old decline, old bottleneck following by recent expansion, and old expansion following by recent decline. Based on two mitochondrial DNA markers, our inferences from ABC analysis, the results of Bayesian skyline plot, the implications of star-like networks, and the patterns of genetic diversity (high haplotype diversity and low-to-moderate nucleotide diversity indicated a sudden population expansion. ABC allowed us to make strong quantitative inferences about the demographic history of S. brasiliensis. We estimated a small ancestral population size that underwent a drastic fivefold expansion, probably associated with the colonization of newly formed habitats. The estimated time of this expansion was consistent with a humid and warm phase as inferred by speleothem growth phases and travertine records during

  1. Blacktip reef sharks, Carcharhinus melanopterus, have high genetic structure and varying demographic histories in their Indo-Pacific range

    KAUST Repository

    Vignaud, Thomas M.

    2014-10-13

    For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics of blacktip reef sharks, Carcharhinus melanopterus; one of the most abundant reef-associated sharks and the apex predator of many shallow water reefs of the Indian and Pacific Oceans. Our sampling includes 4 widely separated locations in the Indo-Pacific and 11 islands in French Polynesia with different levels of coastal development. Four-teen microsatellite loci were analysed for samples from all locations and two mitochondrial DNA fragments, the control region and cytochrome b, were examined for 10 locations. For microsatellites, genetic diversity is higher for the locations in the large open systems of the Red Sea and Australia than for the fragmented habitat of the smaller islands of French Polynesia. Strong significant structure was found for distant locations with FST values as high as ∼0.3, and a smaller but still significant structure is found within French Polynesia. Both mitochondrial genes show only a few mutations across the sequences with a dominant shared haplotype in French Polynesia and New Caledonia suggesting a common lineage different to that of East Australia. Demographic history analyses indicate population expansions in the Red Sea and Australia that may coincide with sea level changes after climatic events. Expansions and flat signals are indicated for French Polynesia as well as a significant recent bottleneck for Moorea, the most human-impacted lagoon of the locations in French Polynesia.

  2. Blacktip reef sharks, Carcharhinus melanopterus, have high genetic structure and varying demographic histories in their Indo-Pacific range.

    Science.gov (United States)

    Vignaud, Thomas M; Mourier, Johann; Maynard, Jeffrey A; Leblois, Raphael; Spaet, Julia; Clua, Eric; Neglia, Valentina; Planes, Serge

    2014-11-01

    For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics of blacktip reef sharks, Carcharhinus melanopterus; one of the most abundant reef-associated sharks and the apex predator of many shallow water reefs of the Indian and Pacific Oceans. Our sampling includes 4 widely separated locations in the Indo-Pacific and 11 islands in French Polynesia with different levels of coastal development. Four-teen microsatellite loci were analysed for samples from all locations and two mitochondrial DNA fragments, the control region and cytochrome b, were examined for 10 locations. For microsatellites, genetic diversity is higher for the locations in the large open systems of the Red Sea and Australia than for the fragmented habitat of the smaller islands of French Polynesia. Strong significant structure was found for distant locations with FST values as high as ~0.3, and a smaller but still significant structure is found within French Polynesia. Both mitochondrial genes show only a few mutations across the sequences with a dominant shared haplotype in French Polynesia and New Caledonia suggesting a common lineage different to that of East Australia. Demographic history analyses indicate population expansions in the Red Sea and Australia that may coincide with sea level changes after climatic events. Expansions and flat signals are indicated for French Polynesia as well as a significant recent bottleneck for Moorea, the most human-impacted lagoon of the locations in French Polynesia. © 2014 John Wiley & Sons Ltd.

  3. Population demographics and life history of the round hickorynut (Obovaria subrotunda) in the Duck River, Tennessee

    Science.gov (United States)

    Ehlo, Chase A.; Layzer, James B.

    2014-01-01

    Population characteristics and life history aspects of healthy mussel populations are poorly understood. The reproductive cycle, age and growth, and population structure of Obovaria subrotunda were examined at four sites in the middle Duck River, Tennessee. Obovaria subrotunda was confirmed to be a bradytictic species, spawning in the late summer and holding glochidia in the gills for 11 mo until the following summer. Fecundity was positively related to mussel length (R2  =  0.75) and ranged from 7122 to 76,584 glochidia. Fourteen species of fish found in the Duck River, in the families Percidae, Cyprinidae, and Cottidae, were infested with glochidia in the laboratory to examine potential hosts. Juveniles transformed onEtheostoma blennioides (greenside darter), E. obama (spangled darter), E. flabellare (fantail darter), and Cottus carolinae (banded sculpin). Analyses of shell thin-sections indicated that males grew faster and obtained a larger size than females. Individuals live to at least 14 y old. Females became sexually mature at age one. Four sites were quantitatively sampled using a systematic design with three random starts. The observed ratio of adult males to females (0.9∶1) did not differ significantly from 1∶1. Results of the quantitative sampling showed an increase in density compared to earlier studies and a high proportion of 1 to 5 y old O. subrotunda.

  4. The Complex Demographic History and Evolutionary Origin of the Western Honey Bee, Apis Mellifera.

    Science.gov (United States)

    Cridland, Julie M; Tsutsui, Neil D; Ramírez, Santiago R

    2017-02-01

    The western honey bee, Apis mellifera, provides critical pollination services to agricultural crops worldwide. However, despite substantial interest and prior investigation, the early evolution and subsequent diversification of this important pollinator remain uncertain. The primary hypotheses place the origin of A. mellifera in either Asia or Africa, with subsequent radiations proceeding from one of these regions. Here, we use two publicly available whole-genome data sets plus newly sequenced genomes and apply multiple population genetic analysis methods to investigate the patterns of ancestry and admixture in native honey bee populations from Europe, Africa, and the Middle East. The combination of these data sets is critical to the analyses, as each contributes samples from geographic locations lacking in the other, thereby producing the most complete set of honey bee populations available to date. We find evidence supporting an origin of A. mellifera in the Middle East or North Eastern Africa, with the A and Y lineages representing the earliest branching lineages. This finding has similarities with multiple contradictory hypotheses and represents a disentangling of genetic relationships, geographic proximity, and secondary contact to produce a more accurate picture of the origins of A. mellifera. We also investigate how previous studies came to their various conclusions based on incomplete sampling of populations, and illustrate the importance of complete sampling in understanding evolutionary processes. These results provide fundamental knowledge about genetic diversity within Old World honey bee populations and offer insight into the complex history of an important pollinator. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

  5. Spatial patterning and floral synchrony among trillium populations with contrasting histories of herbivory

    Directory of Open Access Journals (Sweden)

    Christopher R. Webster

    2015-02-01

    Full Text Available We investigated the spatial patterning and floral synchrony within and among populations of a non-clonal, forest understory herb, Trillium catesbaei. Two populations of T. catesbaei within Great Smoky Mountains National Park were monitored for five years: Cades Cove (high deer abundance and Whiteoak Sink (low deer abundance. All individuals within each population were mapped during year one and five. Only flowering and single-leaf juveniles were mapped during intervening years. Greater distances between flowering plants (plants currently in flower and substantially lower population densities and smaller patch sizes were observed at Cades Cove versus Whiteoak Sink. However, with the exception of flowering plants, contrasting histories of herbivory did not appear to fundamentally alter the spatial patterning of the T. catesbaei population at Cades Cove, an area with a long and well-documented history of deer overabundance. Regardless of browse history, non-flowering life stages were significantly clustered at all spatial scales examined. Flowering plants were clustered in all years at Whiteoak Sink, but more often randomly distributed at Cades Cove, possibly as a result of their lower abundance. Between years, however, there was a positive spatial association between the locations of flowering plants at both sites. Flowering rate was synchronous between sites, but lagged a year behind favorable spring growing conditions, which likely allowed plants to allocate photosynthate from a favorable year towards flowering the subsequent year. Collectively, our results suggest that chronically high levels of herbivory may be associated with spatial patterning of flowering within populations of a non-clonal plant. They also highlight the persistence of underlying spatial patterns, as evidenced by high levels of spatial clustering among non-flowering individuals, and the pervasive, although muted in a population subjected to chronic herbivory, influence of

  6. Distinguishing bipolar II depression from major depressive disorder with comorbid borderline personality disorder: demographic, clinical, and family history differences.

    Science.gov (United States)

    Zimmerman, Mark; Martinez, Jennifer H; Morgan, Theresa A; Young, Diane; Chelminski, Iwona; Dalrymple, Kristy

    2013-09-01

    Because of the potential treatment implications, it is clinically important to distinguish between bipolar II depression and major depressive disorder with comorbid borderline personality disorder. The high frequency of diagnostic co-occurrence and resemblance of phenomenological features has led some authors to suggest that borderline personality disorder is part of the bipolar spectrum. Few studies have directly compared patients with bipolar disorder and borderline personality disorder. In the present study from the Rhode Island Methods to Improve Diagnostic Assessment and Services project, we compared these 2 groups of patients on demographic, clinical, and family history variables. From December 1995 to May 2012, 3,600 psychiatric patients presenting to the outpatient practice at Rhode Island Hospital (Providence, Rhode Island) were evaluated with semistructured diagnostic interviews for DSM-IV Axis I and Axis II disorders. The focus of the present study is the 206 patients with DSM-IV major depressive disorder and borderline personality disorder (MDD-BPD) and 62 patients with DSM-IV bipolar II depression without borderline personality disorder. The patients with MDD-BPD were significantly more often diagnosed with posttraumatic stress disorder (P depression had a significantly higher morbid risk for bipolar disorder in their first-degree relatives than the MDD-BPD patients (P depression and major depressive disorder with comorbid borderline personality disorder differed on a number of clinical and family history variables, thereby supporting the validity of this distinction. © Copyright 2013 Physicians Postgraduate Press, Inc.

  7. Comparative phylogeography and demographic history of European shads (Alosa alosa and A. fallax inferred from mitochondrial DNA

    Directory of Open Access Journals (Sweden)

    Faria Rui

    2012-09-01

    . fallax, migration from the Mediterranean to the Atlantic was detected but not in the opposite direction, with colonization of the North Atlantic probably occurring after last glacial maximum. Conclusion The similar haplotype network topologies between the two species support a common intraspecific history of isolation. Despite these similarities, A. alosa and A. fallax have clearly responded differently to the hydrological dynamics of the Pleistocene, as reflected in their distinct demographic histories. As the species additionally occupy different ecological niches it should not be surprising that they differ in resilience to natural or human-mediated climatic changes. For A. fallax, it is further clear that its demographic response to large-scale hydrological events is not synchronized between the Atlantic and Mediterranean basins. These regional and species-specific differences should be incorporated into future predictive modeling of biological response to climate change as well as current management concepts.

  8. Comparative phylogeography and demographic history of European shads (Alosa alosa and A. fallax) inferred from mitochondrial DNA.

    Science.gov (United States)

    Faria, Rui; Weiss, Steven; Alexandrino, Paulo

    2012-09-30

    Atlantic was detected but not in the opposite direction, with colonization of the North Atlantic probably occurring after last glacial maximum. The similar haplotype network topologies between the two species support a common intraspecific history of isolation. Despite these similarities, A. alosa and A. fallax have clearly responded differently to the hydrological dynamics of the Pleistocene, as reflected in their distinct demographic histories. As the species additionally occupy different ecological niches it should not be surprising that they differ in resilience to natural or human-mediated climatic changes. For A. fallax, it is further clear that its demographic response to large-scale hydrological events is not synchronized between the Atlantic and Mediterranean basins. These regional and species-specific differences should be incorporated into future predictive modeling of biological response to climate change as well as current management concepts.

  9. Range-wide multilocus phylogeography of the red fox reveals ancient continental divergence, minimal genomic exchange and distinct demographic histories.

    Science.gov (United States)

    Statham, Mark J; Murdoch, James; Janecka, Jan; Aubry, Keith B; Edwards, Ceiridwen J; Soulsbury, Carl D; Berry, Oliver; Wang, Zhenghuan; Harrison, David; Pearch, Malcolm; Tomsett, Louise; Chupasko, Judith; Sacks, Benjamin N

    2014-10-01

    Widely distributed taxa provide an opportunity to compare biogeographic responses to climatic fluctuations on multiple continents and to investigate speciation. We conducted the most geographically and genomically comprehensive study to date of the red fox (Vulpes vulpes), the world's most widely distributed wild terrestrial carnivore. Analyses of 697 bp of mitochondrial sequence in ~1000 individuals suggested an ancient Middle Eastern origin for all extant red foxes and a 400 kya (SD = 139 kya) origin of the primary North American (Nearctic) clade. Demographic analyses indicated a major expansion in Eurasia during the last glaciation (~50 kya), coinciding with a previously described secondary transfer of a single matriline (Holarctic) to North America. In contrast, North American matrilines (including the transferred portion of Holarctic clade) exhibited no signatures of expansion until the end of the Pleistocene (~12 kya). Analyses of 11 autosomal loci from a subset of foxes supported the colonization time frame suggested by mtDNA (and the fossil record) but, in contrast, reflected no detectable secondary transfer, resulting in the most fundamental genomic division of red foxes at the Bering Strait. Endemic continental Y-chromosome clades further supported this pattern. Thus, intercontinental genomic exchange was overall very limited, consistent with long-term reproductive isolation since the initial colonization of North America. Based on continental divergence times in other carnivoran species pairs, our findings support a model of peripatric speciation and are consistent with the previous classification of the North American red fox as a distinct species, V. fulva. © 2014 John Wiley & Sons Ltd.

  10. Inferring contemporary levels of gene flow and demographic history in a local population of the leaf beetle Gonioctena olivacea from mitochondrial DNA sequence variation.

    Science.gov (United States)

    Mardulyn, Patrick; Milinkovitch, Michel C

    2005-05-01

    We have studied mitochondrial DNA variation in a local population of the leaf beetle species Gonioctena olivacea, to check whether its apparent low dispersal behaviour affects its pattern of genetic variation at a small geographical scale. We have sampled 10 populations of G. olivacea within a rectangle of 5 x 2 km in the Belgian Ardennes, as well as five populations located approximately along a straight line of 30 km and separated by distances of 3-12 km. For each sampled individual (8-19 per population), a fragment of the mtDNA control region was polymerase chain reaction-amplified and sequenced. Sequence data were analysed to test whether significant genetic differentiation could be detected among populations separated by such relatively short distances. The reconstructed genealogy of the mitochondrial haplotypes was also used to investigate the demographic history of these populations. Computer simulations of the evolution of populations were conducted to assess the minimum amount of gene flow that is necessary to explain the observed pattern of variation in the samples. Results show that migration among populations included in the rectangle of 5 x 2 km is substantial, and probably involves the occurrence of dispersal flights. This appears difficult to reconcile with the results of a previous ecological field study that concluded that most of this species dispersal occurs by walking. While sufficient migration to homogenize genetic diversity occurs among populations separated by distances of a few hundred metres to a few kilometres, distances greater than 5 km results in contrast in strong differentiation among populations, suggesting that migration is drastically reduced on such distances. Finally, the results of coalescent simulations suggest that the star-like genealogy inferred from the mtDNA sequence data is fully compatible with a past demographic expansion. However, a metapopulation structure alone (without the need to invoke a population expansion

  11. A brief history of the changing occupations and demographics of coleopterists from the 18th through the 20th century.

    Science.gov (United States)

    Elias, Scott A

    2014-01-01

    Systematic entomology flourished as a branch of Natural History from the 1750s to the end of the nineteenth century. During this interval, the "era of Heroic Entomology," the majority of workers in the field were dedicated amateurs. This article traces the demographic and occupational shifts in entomology through this 150-year interval and into the early twentieth century. The survey is based on entomologists who studied beetles (Coleoptera), and who named sufficient numbers of species to have their own names abbreviated by subsequent taxonomists. In the eighteenth century, 27 entomologists achieved this level of prominence, of whom 37% were academics, 19% were doctors, 11% had private incomes, 19% were clergymen, and 8% were government officials. Many of those with private incomes were members of the European aristocracy, and all but one were European men. The nineteenth century list included 192 entomologists, of whom 17% were academics, 16% were museum curators, 2% were school teachers, 15% were doctors, 6% were military men, 7% were merchants, 2% were government entomologists, 6% had private incomes, 5% were clergymen, 5% were government officials, and 4% were lawyers. The demographics of entomology shifted dramatically in the nineteenth century. Whereas many of the noteworthy entomologists of the eighteenth century were German, Swedish, or French, in the nineteenth century, many more European countries are represented, and almost one-fifth of the noteworthy entomologists were from the United States. The nineteenth century list, like the eighteenth century list, contains no women. By the twentieth century, 63% of 178 noteworthy systematic entomologists were paid professionals, teaching entomology courses in universities, or studying insect taxonomy in museums and government-sponsored laboratories. Only one person on the twentieth century list had a private income, but women (ten individuals) were included on the list for the first time.

  12. [Analysis of the genetic and demographic structure of populations from Aginskii Buryat district contrasting in habitation conditions].

    Science.gov (United States)

    Tabikhanov, L E; Osipova, L P

    2012-12-01

    Genetic and demographic characteristics of populations from two settlements from the Aginskii Buryat district of Trans-Baikal krai (Alkhanai and Orlovskii) were studied. It was demonstrated that the mononational Buryat settlement of Alkhanai, located in the agrarian Dul'durginskii region of the district far from large settlements and transport highways, is characterized by a large prereproductive volume (45%) and by a small share of individuals from the elderly age group (16.4%). A shift in age characteristics in the Buryat group (36.6 and 22.4%, respectively) was detected in the urban settlement of Orlovskii with a population of mixed ethnic composition, located in a densely populated industrialized part of the district. A modified sex ratio was also demonstrated in Alkhanai as opposed to the Buryat part of the Orlovskii population (sex indices were 0.94 and 0.99). Analysis of population mixture was conducted; marriage structure and migrations were described. The endogamy index of the Alkhanai locality was 0.41; in the group of Buryats from Orlovskii, 0.09. A decrease in the amount of pregnancies and births and a larger distribution of family planning practice among Buryats from Orlovskii were detected. The average amount of births of living children per woman in Alkhanai was 5.11; in Buryats from Orlovskii, 3.90. The selection pressure was estimated as low by means of the Crow index (I(tot) 0.28-0.48). In all described groups, a component that characterizes differential fertility (I(f)) exceeds the child mortality component (I(m)).

  13. Revealing the maternal demographic history of Panthera leo using ancient DNA and a spatially explicit genealogical analysis.

    Science.gov (United States)

    Barnett, Ross; Yamaguchi, Nobuyuki; Shapiro, Beth; Ho, Simon Y W; Barnes, Ian; Sabin, Richard; Werdelin, Lars; Cuisin, Jacques; Larson, Greger

    2014-04-02

    Understanding the demographic history of a population is critical to conservation and to our broader understanding of evolutionary processes. For many tropical large mammals, however, this aim is confounded by the absence of fossil material and by the misleading signal obtained from genetic data of recently fragmented and isolated populations. This is particularly true for the lion which as a consequence of millennia of human persecution, has large gaps in its natural distribution and several recently extinct populations. We sequenced mitochondrial DNA from museum-preserved individuals, including the extinct Barbary lion (Panthera leo leo) and Iranian lion (P. l. persica), as well as lions from West and Central Africa. We added these to a broader sample of lion sequences, resulting in a data set spanning the historical range of lions. Our Bayesian phylogeographical analyses provide evidence for highly supported, reciprocally monophyletic lion clades. Using a molecular clock, we estimated that recent lion lineages began to diverge in the Late Pleistocene. Expanding equatorial rainforest probably separated lions in South and East Africa from other populations. West African lions then expanded into Central Africa during periods of rainforest contraction. Lastly, we found evidence of two separate incursions into Asia from North Africa, first into India and later into the Middle East. We have identified deep, well-supported splits within the mitochondrial phylogeny of African lions, arguing for recognition of some regional populations as worthy of independent conservation. More morphological and nuclear DNA data are now needed to test these subdivisions.

  14. Low Genetic Diversity in Wide-Spread Eurasian Liver Fluke Opisthorchis felineus Suggests Special Demographic History of This Trematode Species

    Science.gov (United States)

    Brusentsov, Ilja I.; Katokhin, Alexey V.; Brusentsova, Irina V.; Shekhovtsov, Sergei V.; Borovikov, Sergei N.; Goncharenko, Grigoriy G.; Lider, Lyudmila A.; Romashov, Boris V.; Rusinek, Olga T.; Shibitov, Samat K.; Suleymanov, Marat M.; Yevtushenko, Andrey V.; Mordvinov, Viatcheslav A.

    2013-01-01

    Opisthorchis felineus or Siberian liver fluke is a trematode parasite (Opisthorchiidae) that infects the hepato-biliary system of humans and other mammals. Despite its public health significance, this wide-spread Eurasian species is one of the most poorly studied human liver flukes and nothing is known about its population genetic structure and demographic history. In this paper, we attempt to fill this gap for the first time and to explore the genetic diversity in O. felineus populations from Eastern Europe (Ukraine, European part of Russia), Northern Asia (Siberia) and Central Asia (Northern Kazakhstan). Analysis of marker DNA fragments from O. felineus mitochondrial cytochrome c oxidase subunit 1 and 3 (cox1, cox3) and nuclear rDNA internal transcribed spacer 1 (ITS1) sequences revealed that genetic diversity is very low across the large geographic range of this species. Microevolutionary processes in populations of trematodes may well be influenced by their peculiar biology. Nevertheless, we suggest that lack of population genetics structure observed in O. felineus can be primarily explained by the Pleistocene glacial events and subsequent sudden population growth from a very limited group of founders. Rapid range expansion of O. felineus through Asian and European territories after severe bottleneck points to a high dispersal potential of this trematode species. PMID:23634228

  15. A worldwide survey of human male demographic history based on Y-SNP and Y-STR data from the HGDP-CEPH populations

    NARCIS (Netherlands)

    W. Shi (Wentao); Q. Ayub (Qasim); M. Vermeulen (Mark); R.G. Shao (Rong Guang); S.B. Zuniga (Sofia); K. van der Gaag (Kristiaan); P. de Knijff (Peter); M.H. Kayser (Manfred); Y. Xue (Yali); C. Tyler-Smith (Chris)

    2010-01-01

    textabstractWe have investigated human male demographic history using 590 males from 51 populations in the Human Genome Diversity Project-Centre d'Étude du Polymorphisme Humain worldwide panel, typed with 37 Y-chromosomal Single Nucleotide Polymorphisms and 65 Y-chromosomal Short Tandem Repeats and

  16. Genome-wide analyses of the Bemisia tabaci species complex reveal contrasting patterns of admixture and complex demographic histories.

    Directory of Open Access Journals (Sweden)

    S Elfekih

    Full Text Available Once considered a single species, the whitefly, Bemisia tabaci, is a complex of numerous morphologically indistinguishable species. Within the last three decades, two of its members (MED and MEAM1 have become some of the world's most damaging agricultural pests invading countries across Europe, Africa, Asia and the Americas and affecting a vast range of agriculturally important food and fiber crops through both feeding-related damage and the transmission of numerous plant viruses. For some time now, researchers have relied on a single mitochondrial gene and/or a handful of nuclear markers to study this species complex. Here, we move beyond this by using 38,041 genome-wide Single Nucleotide Polymorphisms, and show that the two invasive members of the complex are closely related species with signatures of introgression with a third species (IO. Gene flow patterns were traced between contemporary invasive populations within MED and MEAM1 species and these were best explained by recent international trade. These findings have profound implications for delineating the B. tabaci species status and will impact quarantine measures and future management strategies of this global pest.

  17. Do Insect Populations Die at Constant Rates as They Become Older? Contrasting Demographic Failure Kinetics with Respect to Temperature According to the Weibull Model.

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    Petros Damos

    Full Text Available Temperature implies contrasting biological causes of demographic aging in poikilotherms. In this work, we used the reliability theory to describe the consistency of mortality with age in moth populations and to show that differentiation in hazard rates is related to extrinsic environmental causes such as temperature. Moreover, experiments that manipulate extrinsic mortality were used to distinguish temperature-related death rates and the pertinence of the Weibull aging model. The Newton-Raphson optimization method was applied to calculate parameters for small samples of ages at death by estimating the maximum likelihoods surfaces using scored gradient vectors and the Hessian matrix. The study reveals for the first time that the Weibull function is able to describe contrasting biological causes of demographic aging for moth populations maintained at different temperature regimes. We demonstrate that at favourable conditions the insect death rate accelerates as age advances, in contrast to the extreme temperatures in which each individual drifts toward death in a linear fashion and has a constant chance of passing away. Moreover, slope of hazard rates shifts towards a constant initial rate which is a pattern demonstrated by systems which are not wearing out (e.g. non-aging since the failure, or death, is a random event independent of time. This finding may appear surprising, because, traditionally, it was mostly thought as rule that in aging population force of mortality increases exponentially until all individuals have died. Moreover, in relation to other studies, we have not observed any typical decelerating aging patterns at late life (mortality leveling-off, but rather, accelerated hazard rates at optimum temperatures and a stabilized increase at the extremes.In most cases, the increase in aging-related mortality was simulated reasonably well according to the Weibull survivorship model that is applied. Moreover, semi log- probability hazard

  18. Divorcing the Late Upper Palaeolithic demographic histories of mtDNA haplogroups M1 and U6 in Africa

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    Pennarun Erwan

    2012-12-01

    Full Text Available Abstract Background A Southwest Asian origin and dispersal to North Africa in the Early Upper Palaeolithic era has been inferred in previous studies for mtDNA haplogroups M1 and U6. Both haplogroups have been proposed to show similar geographic patterns and shared demographic histories. Results We report here 24 M1 and 33 U6 new complete mtDNA sequences that allow us to refine the existing phylogeny of these haplogroups. The resulting phylogenetic information was used to genotype a further 131 M1 and 91 U6 samples to determine the geographic spread of their sub-clades. No southwest Asian specific clades for M1 or U6 were discovered. U6 and M1 frequencies in North Africa, the Middle East and Europe do not follow similar patterns, and their sub-clade divisions do not appear to be compatible with their shared history reaching back to the Early Upper Palaeolithic. The Bayesian Skyline Plots testify to non-overlapping phases of expansion, and the haplogroups’ phylogenies suggest that there are U6 sub-clades that expanded earlier than those in M1. Some M1 and U6 sub-clades could be linked with certain events. For example, U6a1 and M1b, with their coalescent ages of ~20,000–22,000 years ago and earliest inferred expansion in northwest Africa, could coincide with the flourishing of the Iberomaurusian industry, whilst U6b and M1b1 appeared at the time of the Capsian culture. Conclusions Our high-resolution phylogenetic dissection of both haplogroups and coalescent time assessments suggest that the extant main branching pattern of both haplogroups arose and diversified in the mid-later Upper Palaeolithic, with some sub-clades concomitantly with the expansion of the Iberomaurusian industry. Carriers of these maternal lineages have been later absorbed into and diversified further during the spread of Afro-Asiatic languages in North and East Africa.

  19. The impact of selection, gene flow and demographic history on heterogeneous genomic divergence: three-spine sticklebacks in divergent environments.

    Science.gov (United States)

    Ferchaud, Anne-Laure; Hansen, Michael M

    2016-01-01

    Heterogeneous genomic divergence between populations may reflect selection, but should also be seen in conjunction with gene flow and drift, particularly population bottlenecks. Marine and freshwater three-spine stickleback (Gasterosteus aculeatus) populations often exhibit different lateral armour plate morphs. Moreover, strikingly parallel genomic footprints across different marine-freshwater population pairs are interpreted as parallel evolution and gene reuse. Nevertheless, in some geographic regions like the North Sea and Baltic Sea, different patterns are observed. Freshwater populations in coastal regions are often dominated by marine morphs, suggesting that gene flow overwhelms selection, and genomic parallelism may also be less pronounced. We used RAD sequencing for analysing 28 888 SNPs in two marine and seven freshwater populations in Denmark, Europe. Freshwater populations represented a variety of environments: river populations accessible to gene flow from marine sticklebacks and large and small isolated lakes with and without fish predators. Sticklebacks in an accessible river environment showed minimal morphological and genomewide divergence from marine populations, supporting the hypothesis of gene flow overriding selection. Allele frequency spectra suggested bottlenecks in all freshwater populations, and particularly two small lake populations. However, genomic footprints ascribed to selection could nevertheless be identified. No genomic regions were consistent freshwater-marine outliers, and parallelism was much lower than in other comparable studies. Two genomic regions previously described to be under divergent selection in freshwater and marine populations were outliers between different freshwater populations. We ascribe these patterns to stronger environmental heterogeneity among freshwater populations in our study as compared to most other studies, although the demographic history involving bottlenecks should also be considered in the

  20. A demographic history of a population of howler monkeys (Alouatta palliata living in a fragmented landscape in Mexico

    Directory of Open Access Journals (Sweden)

    Jurgi Cristóbal Azkarate

    2017-08-01

    Full Text Available Long-term field studies are critical for our understanding of animal life history and the processes driving changes in demography. Here, we present long-term demographic data for the northernmost population of mantled howler monkeys (Alouatta palliata residing in a highly anthropogenically fragmented landscape in Los Tuxtlas, Mexico. We carried out 454 monthly group visits to 10 groups of mantled howler monkeys between 2000 and 2011. The population remained relatively stable over the 11-year study period, with an overall increase in the total number of individuals. Birth rates and inter-birth intervals were comparable to those of howler monkeys at non-fragmented sites, suggesting that living in a fragmented landscape did not affect the reproductive output of our study population. Moreover, despite the landscape, dispersal events were commonplace, including many secondary dispersals (individuals emigrating from groups that they had previously immigrated into. Finally, we found a marked effect of seasonality on the dynamics of our study population. In particular, the period of lowest temperatures and resource scarcity between November and March was associated with higher mortality and reproductive inhibition, while the period of resource abundance between April and May was associated with the majority of conceptions and weaning of offspring. This, in turn, could be influencing dispersal patterns in our study area, as male howler monkeys seem to time some of their immigrations into new groups to coincide with the start of the period of higher fertility, while females preferentially joined new groups several months before the onset of this period. These data have important implications for the conservation and management of howler monkeys in fragmented landscapes, as well as for our understanding of the effect of seasonality over howler monkey dispersal, reproduction and survival.

  1. Genetic variability, local selection and demographic history: genomic evidence of evolving towards allopatric speciation in Asian seabass.

    Science.gov (United States)

    Wang, Le; Wan, Zi Yi; Lim, Huan Sein; Yue, Gen Hua

    2016-08-01

    Genomewide analysis of genetic divergence is critically important in understanding the genetic processes of allopatric speciation. We sequenced RAD tags of 131 Asian seabass individuals of six populations from South-East Asia and Australia/Papua New Guinea. Using 32 433 SNPs, we examined the genetic diversity and patterns of population differentiation across all the populations. We found significant evidence of genetic heterogeneity between South-East Asian and Australian/Papua New Guinean populations. The Australian/Papua New Guinean populations showed a rather lower level of genetic diversity. FST and principal components analysis revealed striking divergence between South-East Asian and Australian/Papua New Guinean populations. Interestingly, no evidence of contemporary gene flow was observed. The demographic history was further tested based on the folded joint site frequency spectrum. The scenario of ancient migration with historical population size changes was suggested to be the best fit model to explain the genetic divergence of Asian seabass between South-East Asia and Australia/Papua New Guinea. This scenario also revealed that Australian/Papua New Guinean populations were founded by ancestors from South-East Asia during mid-Pleistocene and were completely isolated from the ancestral population after the last glacial retreat. We also detected footprints of local selection, which might be related to differential ecological adaptation. The ancient gene flow was examined and deemed likely insufficient to counteract the genetic differentiation caused by genetic drift. The observed genomic pattern of divergence conflicted with the 'genomic islands' scenario. Altogether, Asian seabass have likely been evolving towards allopatric speciation since the split from the ancestral population during mid-Pleistocene. © 2016 John Wiley & Sons Ltd.

  2. Inferring Genetic Variation and Demographic History of Michelia yunnanensis Franch. (Magnoliaceae from Chloroplast DNA Sequences and Microsatellite Markers

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    Shikang Shen

    2017-04-01

    Full Text Available Michelia yunnanensis Franch., is a traditional ornamental, aromatic, and medicinal shrub that endemic to Yunnan Province in southwest China. Although the species has a large distribution pattern and is abundant in Yunnan Province, the populations are dramatically declining because of overexploitation and habitat destruction. Studies on the genetic variation and demography of endemic species are necessary to develop effective conservation and management strategies. To generate such knowledge, we used 3 pairs of universal cpDNA markers and 10 pairs of microsatellite markers to assess the genetic diversity, genetic structure, and demographic history of 7 M. yunnanensis populations. We calculated a total of 88 alleles for 10 polymorphic loci and 10 haplotypes for a combined 2,089 bp of cpDNA. M. yunnanensis populations showed high genetic diversity (Ho = 0.551 for nuclear markers and Hd = 0.471 for cpDNA markers and low genetic differentiation (FST = 0.058. Geographical structure was not found among M. yunnanensis populations. Genetic distance and geographic distance were not correlated (P > 0.05, which indicated that geographic isolation is not the primary cause of the low genetic differentiation of M. yunnanensis. Additionally, M. yunnanensis populations contracted ~20,000–30,000 years ago, and no recent expansion occurred in current populations. Results indicated that the high genetic diversity of the species and within its populations holds promise for effective genetic resource management and sustainable utilization. Thus, we suggest that the conservation and management of M. yunnanensis should address exotic overexploitation and habitat destruction.

  3. Reconciling deep calibration and demographic history: bayesian inference of post glacial colonization patterns in Carcinus aestuarii (Nardo, 1847 and C. maenas (Linnaeus, 1758.

    Directory of Open Access Journals (Sweden)

    Ilaria A M Marino

    Full Text Available A precise inference of past demographic histories including dating of demographic events using bayesian methods can only be achieved with the use of appropriate molecular rates and evolutionary models. Using a set of 596 mitochondrial cytochrome c oxidase I (COI sequences of two sister species of European green crabs of the genus Carcinus (C. maenas and C. aestuarii, our study shows how chronologies of past evolutionary events change significantly with the application of revised molecular rates that incorporate biogeographic events for calibration and appropriate demographic priors. A clear signal of demographic expansion was found for both species, dated between 10,000 and 20,000 years ago, which places the expansions events in a time frame following the Last Glacial Maximum (LGM. In the case of C. aestuarii, a population expansion was only inferred for the Adriatic-Ionian, suggestive of a colonization event following the flooding of the Adriatic Sea (18,000 years ago. For C. maenas, the demographic expansion inferred for the continental populations of West and North Europe might result from a northward recolonization from a southern refugium when the ice sheet retreated after the LGM. Collectively, our results highlight the importance of using adequate calibrations and demographic priors in order to avoid considerable overestimates of evolutionary time scales.

  4. Comparative demography of an epiphytic lichen: support for general life history patterns and solutions to common problems in demographic parameter estimation.

    Science.gov (United States)

    Shriver, Robert K; Cutler, Kerry; Doak, Daniel F

    2012-09-01

    Lichens are major components in many terrestrial ecosystems, yet their population ecology is at best only poorly understood. Few studies have fully quantified the life history or demographic patterns of any lichen, with particularly little attention to epiphytic species. We conducted a 6-year demographic study of Vulpicida pinastri, an epiphytic foliose lichen, in south-central Alaska. After testing multiple size-structured functions to describe patterns in each V. pinastri demographic rate, we used the resulting estimates to construct a stochastic demographic model for the species. This model development led us to propose solutions to two general problems in construction of demographic models for many taxa: how to simply but accurately characterize highly skewed growth rates, and how to estimate recruitment rates that are exceptionally difficult to directly observe. Our results show that V. pinastri has rapid and variable growth and, for small individuals, low and variable survival, but that these traits are coupled with considerable longevity (e.g., >50 years mean future life span for a 4-cm(2) thallus) and little deviation of the stochastic population growth rate from the deterministic expectation. Comparisons of the demographic patterns we found with those of other lichen studies suggest that their relatively simple architecture may allow clearer generalities about growth patterns for lichens than for other taxa, and that the expected pattern of faster growth rates for epiphytic species is substantiated.

  5. From the past to the present: Wolf phylogeography and demographic history based on the mitochondrial control region

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    Erik Ersmark

    2016-12-01

    Full Text Available The global distribution of the grey wolf (Canis lupus is a complex assembly consisting of a large number of populations and described subspecies. How these lineages are related to one another is still not fully resolved, largely due to the fact that large geographical regions remain poorly sampled both at the core and periphery of the species’ range. Analyses of ancient wolves have also suffered from uneven sampling, but have shown indications of a major turnover at some point during the Pleistocene-Holocene boundary in northern North America. Here we analyze variation in the mitochondrial control region in 122 contemporary wolves from some of the less studied populations, as well as six samples from the previously unstudied Greenland subspecies (Canis l. orion and two Late Pleistocene samples from Siberia. Together with the publicly available control region sequences of both modern and ancient wolves, this study examines genetic diversity on a wide geographical and temporal scale that includes both Eurasia and North America. We identify 13 new haplotypes, of which the majority is found in northern and eastern Asia. The results show that the Greenland samples are all represented by one haplotype, previously identified in North American wolves, among which this population seems to trace its maternal lineage. The phylogeny and network analyses show a wide spatial distribution of several lineages, but also some clusters with more distinct geographical affiliation. In North America, we find support for an end-Pleistocene population bottleneck through coalescent simulations under an approximate Bayesian framework in contrast to previous studies that suggested an extinction-replacement event. However, we find no support for a similar bottleneck in Eurasia. Overall, this global analysis helps to clarify our understanding of the complex history for wolves in Eurasia and North America.

  6. Contrasting latitudinal patterns of life-history divergence in two genera of new world thrushes (Turdinae)

    Science.gov (United States)

    Boyce, Andy J.; Martin, Thomas E.

    2017-01-01

    Several long-standing hypotheses have been proposed to explain latitudinal patterns of life-history strategies. Here, we test predictions of four such hypotheses (seasonality, food limitation, nest predation and adult survival probability) by examining life-history traits and age-specific mortality rates of several species of thrushes (Turdinae) based on field studies at temperate and tropical sites and data gathered from the literature. Thrushes in the genus Catharus showed the typical pattern of slower life-history strategies in the tropics while co-occuring Turdus thrushes differed much less across latitudes. Seasonality is a broadly accepted hypothesis for latitudinal patterns, but the lack of concordance in latitudinal patterns between co-existing genera that experience the same seasonal patterns suggests seasonality cannot fully explain latitudinal trait variation in thrushes. Nest-predation also could not explain patterns based on our field data and literature data for these two genera. Total feeding rates were similar, and per-nestling feeding rates were higher at tropical latitudes in both genera, suggesting food limitation does not explain trait differences in thrushes. Latitudinal patterns of life histories in these two genera were closely associated with adult survival probability. Thus, our data suggest that environmental influences on adult survival probability may play a particularly strong role in shaping latitudinal patterns of life-history traits.

  7. Genetic tools link long-term demographic and life-history traits of anemonefish to their anemone hosts

    KAUST Repository

    Salles, Océ ane C.; Saenz-Agudelo, Pablo; Almany, Glenn R.; Berumen, Michael L.; Thorrold, Simon R.; Jones, Geoffrey P.; Planes, Serge

    2016-01-01

    The life-history traits and population dynamics of species are increasingly being attributed to the characteristics of their preferred habitats. While coral reef fish are often strongly associated with particular habitats, long-term studies

  8. Genetic diversity, outcrossing rate, and demographic history along a climatic gradient in the ruderal plant Ruellia nudiflora (Acanthaceae)

    OpenAIRE

    Vargas-Mendoza, Carlos F.; Ortegón-Campos, Ilka; Marrufo-Zapata, Denis; Herrera, Carlos M.; Parra-Tabla, Víctor

    2015-01-01

    © 2015 Universidad Nacional Autónoma de México, Instituto de Biología. All Rights Reserved. Ruellia nudiflora has shown a high potential to easily invade disturbed areas. Outcrossing rate and genetic structure and diversity in this species were examined along a climatic gradient in the Yucatán Peninsula (Mexico) in order to understand the effects of environmental heterogeneity - isolation by environment (IBE) - as well as correlation in herkogamy on genetic structure, diversity, and demograph...

  9. Comparison of population genetic patterns in two widespread freshwater mussels with contrasting life histories in western North America.

    Science.gov (United States)

    Mock, K E; Brim Box, J C; Chong, J P; Furnish, J; Howard, J K

    2013-12-01

    We investigate population genetic structuring in Margaritifera falcata, a freshwater mussel native to western North America, across the majority of its geographical range. We find shallow rangewide genetic structure, strong population-level structuring and very low population diversity in this species, using both mitochondrial sequence and nuclear microsatellite data. We contrast these patterns with previous findings in another freshwater mussel species group (Anodonta californiensis/A. nuttalliana) occupying the same continental region and many of the same watersheds. We conclude that differences are likely caused by contrasting life history attributes between genera, particularly host fish requirements and hermaphroditism. Further, we demonstrate the occurrence of a 'hotspot' for genetic diversity in both groups of mussels, occurring in the vicinity of the lower Columbia River drainage. We suggest that stream hierarchy may be responsible for this pattern and may produce similar patterns in other widespread freshwater species. © 2013 John Wiley & Sons Ltd.

  10. Contrasting pollen histories of MIS 5e and the Holocene from Lake Titicaca (Bolivia/Peru)

    Science.gov (United States)

    Hanselman, Jennifer A.; Gosling, William D.; Paduano, Gina M.; Bush, Mark B.

    2005-10-01

    Two long sediment records (cores LTO1-2B and LT01-3B) from Lake Titicaca, Bolivia/Peru, are compared with a previously analysed Holocene record from this lake (core NE98-1PC). The Holocene records of LT01-2B and NE98-1PC are similar. There are striking differences, however, between the MIS 5e sections of the long cores and the Holocene records. In these records, temperature is probably the dominant parameter that determines the total fossil pollen concentration and is used to time the onset and termination of deglaciation. In contrast, the relative and absolute abundance of specific taxa (e.g. Polylepis/Acaena, Chenopodiaceae) are indicators of relative moisture availability. Although the Holocene contains a period of aridity between ca. 8000 cal. yr BP and 4300 cal. yr BP, it is a minor event compared with the more extreme aridity of MIS 5e. Core LT01-3B showed similar trends during MIS 5e when compared to LT01-2B, as did NE98-1PC when comparing Holocene records. MIS 5e and the Holocene are markedly different interglacials, depicted by shifts in pollen concentration and taxa representation over time.

  11. Seedling responses to water pulses in shrubs with contrasting histories of grassland encroachment.

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    Steven R Woods

    Full Text Available Woody plant encroachment into grasslands has occurred worldwide, but it is unclear why some tree and shrub species have been markedly more successful than others. For example, Prosopis velutina has proliferated in many grasslands of the Sonoran Desert in North America over the past century, while other shrub species with similar growth form and life history, such as Acacia greggii, have not. We conducted a glasshouse experiment to assess whether differences in early seedling development could help explain why one species and not the other came to dominate many Sonoran Desert grasslands. We established eight watering treatments mimicking a range of natural precipitation patterns and harvested seedlings 16 or 17 days after germination. A. greggii had nearly 7 times more seed mass than P. velutina, but P. velutina emerged earlier (by 3.0±0.3 d and grew faster (by 8.7±0.5 mg d⁻¹. Shoot mass at harvest was higher in A. greggii (99±6 mg seedling⁻¹ than in P. velutina (74±2 mg seedling⁻¹, but there was no significant difference in root mass (54±3 and 49±2 mg seedling⁻¹, respectively. Taproot elongation was differentially sensitive to water supply: under the highest initial watering pulse, taproots were 52±19 mm longer in P. velutina than in A. greggii. Enhanced taproot elongation under favorable rainfall conditions could give nascent P. velutina seedlings growth and survivorship advantages by helping reduce competition with grasses and maintain contact with soil water during drought. Conversely, A. greggii's greater investment in mass per seed appeared to provide little return in early seedling growth. We suggest that such differences in recruitment traits and their sensitivities to environmental conditions may help explain ecological differences between species that are highly similar as adults and help identify pivotal drivers of shrub encroachment into grasslands.

  12. Socio-Demographic, Clinical and Behavioral Characteristics Associated with a History of Suicide Attempts among Psychiatric Outpatients: A Case Control Study in a Northern Mexican City.

    Science.gov (United States)

    Alvarado-Esquivel, Cosme; Sánchez-Anguiano, Luis Francisco; Arnaud-Gil, Carlos Alberto; Hernández-Tinoco, Jesús; Molina-Espinoza, Luis Fernando; Rábago-Sánchez, Elizabeth

    2014-03-01

    Little is known about the epidemiology of suicide attempts among psychiatric outpatients in Mexico. This study was aimed to determine the socio-demographic, clinical and behavioral characteristics associated with suicide attempts in psychiatric outpatients in two public hospitals in Durango, Mexico. Two hundred seventy six psychiatric outpatients (154 suicide attempters and 122 patients without suicide attempt history) attended the two public hospitals in Durango City, Mexico were included in this study. Socio-demographic, clinical and behavioral characteristics were obtained retrospectively from all outpatients and compared in relation to the presence or absence of suicide attempt history. Increased prevalence of suicide attempts was associated with mental and behavioral disorders due to psychoactive substance use (F10-19) (P=0.01), schizophrenia, schizotypal and delusional disorders (F20-29) (P=0.02), mood (affective) disorders (F30-39) (Purban residence (OR=2.31, 95% CI: 1.17-4.57; P=0.01), memory impairment (OR=1.91, 95% CI: 1.07-3.40; P=0.02), alcohol consumption (OR=2.39, 95% CI: 1.21-4.70; P=0.01), and sexual promiscuity (OR=3.90, 95% CI: 1.74-8.77; PMexico. Results may be useful for an optimal planning of preventive measures against suicide attempts in psychiatric outpatients.

  13. Demographic modelling reveals a history of divergence with gene flow for a glacially tied stonefly in a changing post-Pleistocene landscape

    Science.gov (United States)

    Hotaling, Scott; Muhlfeld, Clint C.; Giersch, J. Joseph; Ali, Omar; Jordan, Steve; Miller, Michael R.; Luikart, Gordon; Weisrock, David W.

    2018-01-01

    AimClimate warming is causing extensive loss of glaciers in mountainous regions, yet our understanding of how glacial recession influences evolutionary processes and genetic diversity is limited. Linking genetic structure with the influences shaping it can improve understanding of how species respond to environmental change. Here, we used genome-scale data and demographic modelling to resolve the evolutionary history of Lednia tumana, a rare, aquatic insect endemic to alpine streams. We also employed a range of widely used data filtering approaches to quantify how they influenced population structure results.LocationAlpine streams in the Rocky Mountains of Glacier National Park, Montana, USA.TaxonLednia tumana, a stonefly (Order Plecoptera) in the family Nemouridae.MethodsWe generated single nucleotide polymorphism data through restriction-site associated DNA sequencing to assess contemporary patterns of genetic structure for 11 L. tumana populations. Using identified clusters, we assessed demographic history through model selection and parameter estimation in a coalescent framework. During population structure analyses, we filtered our data to assess the influence of singletons, missing data and total number of markers on results.ResultsContemporary patterns of population structure indicate that L. tumana exhibits a pattern of isolation-by-distance among populations within three genetic clusters that align with geography. Mean pairwise genetic differentiation (FST) among populations was 0.033. Coalescent-based demographic modelling supported divergence with gene flow among genetic clusters since the end of the Pleistocene (~13-17 kya), likely reflecting the south-to-north recession of ice sheets that accumulated during the Wisconsin glaciation.Main conclusionsWe identified a link between glacial retreat, evolutionary history and patterns of genetic diversity for a range-restricted stonefly imperiled by climate change. This finding included a history of

  14. Geographic structure and demographic history of Iranian brown bear (Ursus arctos based on mtDNA control region sequences

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    Mohammad Reza Ashrafzadeh

    2015-12-01

    Full Text Available In recent years, the brown bear's range has declined and its populations in some areas have faced extinction. Therefore, to have a comprehensive picture of genetic diversity and geographic structure of populations is essential for effective conservation strategies. In this research, we sequenced a 271bp segment of mtDNA control region of seven Iranian brown bears, where a total dataset of 467 sequences (brown and polar bears were used in analyses. Overall, 113 different haplotypes and 77 polymorphic sites were identified within the segment. Based on phylogenetic analyses, Iranian brown bears were not nested in any other clades. The low values of Nm (range=0.014-0.187 and high values of Fst (range=0.728-0.972 among Iranian bears and others revealed a genetically significant differentiation. We aren't found any significant signal of demographic reduction in Iranian bears. The time to the most recent common ancestor of Iranian brown bears (Northern Iran was found to be around 19000 BP.

  15. Retention of contrast media in the history of radiology. Sequelae of the former use of thorotrast and new challenges

    International Nuclear Information System (INIS)

    Kaick, G. van; Delorme, S.

    2016-01-01

    Detection of gadolinium deposits in patients who have repeatedly been administered intravenous gadolinium chelates have given rise to concern regarding the long-term safety of magnetic resonance imaging (MRI) contrast media. Nevertheless, negative long-term clinical effects have not yet been observed. In some publications parallels have been drawn to the sequelae of thorotrast that was formerly used for arterial angiography. In this article the history of thorotrast use is briefly described and in particular why, despite warnings, this substance was used frequently and worldwide. A brief summary of the results of the German Thorotrast Study revealed that high excess rates were only observed for primary malignant liver tumors after a 15-year or longer latency period and to a lesser degree of leukemias, as well as for severe local complications due to paravascular injections, particularly in the neck region. Based on this historical review, we will venture to take stock of the outcome from the ''success story'' of this contrast agent. (orig.) [de

  16. Identical metabolic rate and thermal conductance in Rock Sandpiper (Calidris ptilocnemis) subspecies with contrasting nonbreeding life histories

    Science.gov (United States)

    Ruthrauff, Daniel R.; Dekinga, Anne; Gill, Robert E.; Piersma, Theunis

    2013-01-01

    Closely related species or subspecies can exhibit metabolic differences that reflect site-specific environmental conditions. Whether such differences represent fixed traits or flexible adjustments to local conditions, however, is difficult to predict across taxa. The nominate race of Rock Sandpiper (Calidris ptilocnemis) exhibits the most northerly nonbreeding distribution of any shorebird in the North Pacific, being common during winter in cold, dark locations as far north as upper Cook Inlet, Alaska (61°N). By contrast, the tschuktschorum subspecies migrates to sites ranging from about 59°N to more benign locations as far south as ~37°N. These distributional extremes exert contrasting energetic demands, and we measured common metabolic parameters in the two subspecies held under identical laboratory conditions to determine whether differences in these parameters are reflected by their nonbreeding life histories. Basal metabolic rate and thermal conductance did not differ between subspecies, and the subspecies had a similar metabolic response to temperatures below their thermoneutral zone. Relatively low thermal conductance values may, however, reflect intrinsic metabolic adaptations to northerly latitudes. In the absence of differences in basic metabolic parameters, the two subspecies’ nonbreeding distributions will likely be more strongly influenced by adaptations to regional variation in ecological factors such as prey density, prey quality, and foraging habitat.

  17. Historical DNA reveals the demographic history of Atlantic cod (Gadus morhua) in medieval and early modern Iceland.

    Science.gov (United States)

    Ólafsdóttir, Guðbjörg Ásta; Westfall, Kristen M; Edvardsson, Ragnar; Pálsson, Snæbjörn

    2014-02-22

    Atlantic cod (Gadus morhua) vertebrae from archaeological sites were used to study the history of the Icelandic Atlantic cod population in the time period of 1500-1990. Specifically, we used coalescence modelling to estimate population size and fluctuations from the sequence diversity at the cytochrome b (cytb) and Pantophysin I (PanI) loci. The models are consistent with an expanding population during the warm medieval period, large historical effective population size (NE), a marked bottleneck event at 1400-1500 and a decrease in NE in early modern times. The model results are corroborated by the reduction of haplotype and nucleotide variation over time and pairwise population distance as a significant portion of nucleotide variation partitioned across the 1550 time mark. The mean age of the historical fished stock is high in medieval times with a truncation in age in early modern times. The population size crash coincides with a period of known cooling in the North Atlantic, and we conclude that the collapse may be related to climate or climate-induced ecosystem change.

  18. Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

    Directory of Open Access Journals (Sweden)

    Shigeki Nakagome

    Full Text Available Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA and matrilineal mitochondrial DNA (mtDNA. Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA or more than 14 times (mtDNA larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

  19. The role of human demographic history in determining the distribution and frequency of transferase-deficient galactosaemia mutations.

    LENUS (Irish Health Repository)

    Flanagan, J M

    2010-02-01

    Classical or transferase-deficient galactosaemia is an inherited metabolic disorder caused by mutation in the human Galactose-1-phosphate uridyl transferase (GALT) gene. Of some 170 causative mutations reported, fewer than 10% are observed in more than one geographic region or ethnic group. To better understand the population history of the common GALT mutations, we have established a haplotyping system for the GALT locus incorporating eight single nucleotide polymorphisms and three short tandem repeat markers. We analysed haplotypes associated with the three most frequent GALT gene mutations, Q188R, K285N and Duarte-2 (D2), and estimated their age. Haplotype diversity, in conjunction with measures of genetic diversity and of linkage disequilibrium, indicated that Q188R and K285N are European mutations. The Q188R mutation arose in central Europe within the last 20 000 years, with its observed east-west cline of increasing relative allele frequency possibly being due to population expansion during the re-colonization of Europe by Homo sapiens in the Mesolithic age. K285N was found to be a younger mutation that originated in Eastern Europe and is probably more geographically restricted as it arose after all major European population expansions. The D2 variant was found to be an ancient mutation that originated before the expansion of Homo sapiens out of Africa.

  20. Low concentrations, potential ecological consequences: Synthetic estrogens alter life-history and demographic structures of aquatic invertebrates

    International Nuclear Information System (INIS)

    Souza, María Sol; Hallgren, Per; Balseiro, Esteban; Hansson, Lars-Anders

    2013-01-01

    Contraceptive drugs are nowadays found in aquatic environments around the globe. Particularly, 17α-ethinylestradiol (EE 2 ) may act even at low concentrations, such as those recorded in natural ecosystems. We evaluated the physiological effects of EE 2 on cyclopoids and calanoids, common copepods in both marine and freshwater communities. We used three EE 2 concentrations and assessed its impact on activity of different physiological endpoints: Acetylcholinesterase (neurotransmission), Glutathione S-transferase (detoxifying system), and Caspase-3 (apoptosis). While EE 2 exerts, distinctive effect on detoxifying and apoptotic systems, no effect on AChE was observed at environmental doses. Our results show that EE 2 exposure affects differently copepod physiology endpoints, altering moulting process, adult recruitment in calanoids and calanoid to cyclopoid ratio. The ecological consequences of this underlying physiological process may affect since life history to population and community structures, and this represent a new aspects of this xenobiotic in natural systems. Highlights: •We evaluated physiological effects of 17α-ethinylestradiol (EE 2 ) on copepods. •We measured the EE 2 effect on neurotransmission, detoxifying system and apoptosis. •EE 2 exert distinctive effect on detoxifying and apoptotic systems. •EE 2 affects differently calanoids and cyclopoids moulting and adult recruitment. •Physiological impact in invertebrates' communities is a novel aspect of EE 2 effects. -- Anthropogenic estrogens modify the physiological functioning of aquatic invertebrates

  1. Ancestral polymorphisms and sex-biased migration shaped the demographic history of brown bears and polar bears.

    Science.gov (United States)

    Nakagome, Shigeki; Mano, Shuhei; Hasegawa, Masami

    2013-01-01

    Recent studies have reported discordant gene trees in the evolution of brown bears and polar bears. Genealogical histories are different among independent nuclear loci and between biparentally inherited autosomal DNA (aDNA) and matrilineal mitochondrial DNA (mtDNA). Based on multi-locus genomic sequences from aDNA and mtDNA, we inferred the population demography of brown and polar bears and found that brown bears have 6 times (aDNA) or more than 14 times (mtDNA) larger population sizes than polar bears and that polar bear lineage is derived from within brown bear diversity. In brown bears, the effective population size ratio of mtDNA to aDNA was at least 0.62, which deviated from the expected value of 0.25, suggesting matriarchal population due to female philopatry and male-biased migration. These results emphasize that ancestral polymorphisms and sex-biased migration may have contributed to conflicting branching patterns in brown and polar bears across aDNA genes and mtDNA.

  2. Inferences of population structure and demographic history for Taxodium distichum, a coniferous tree in North America, based on amplicon sequencing analysis.

    Science.gov (United States)

    Ikezaki, Yuka; Suyama, Yoshihisa; Middleton, Beth A; Tsumura, Yoshihiko; Teshima, Kousuke; Tachida, Hidenori; Kusumi, Junko

    2016-11-01

    Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum, is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences in two varieties, T. distichum var. distichum (bald cypress) and T. distichum var. imbricarium (pond cypress), are well known, but little is known about the level of genetic differentiation between the varieties and the demographic history of local populations. We analyzed nucleotide polymorphisms at 47 nuclear loci from 96 individuals collected from the Mississippi River Alluvial Valley (MRAV), and Gulf Coastal populations in Texas, Louisiana, and Florida using high-throughput DNA sequencing. Standard population genetic statistics were calculated, and demographic parameters were estimated using a composite-likelihood approach. Taxodium distichum in North America can be divided into at least three genetic groups, bald cypress in the MRAV and Texas, bald cypress in Florida, and pond cypress in Florida. The levels of genetic differentiation among the groups were low but significant. Several loci showed the signatures of positive selection, which might be responsible for local adaptation or varietal differentiation. Bald cypress was genetically differentiated into two geographical groups, and the boundary was located between the MRAV and Florida. This differentiation could be explained by population expansion from east to west. Despite the overlap of the two varieties' ranges, they were genetically differentiated in Florida. The estimated demographic parameters suggested that pond cypress split from bald cypress during the late Miocene. © 2016 Botanical Society of America.

  3. Inference of population structure and demographic history in Taxodium distichum, a coniferous tree in North America, based on amplicon sequence analysis

    Science.gov (United States)

    Ikezaki, Yuka; Suyama, Yoshihisa; Middleton, Beth A.; Tsumura, Yoshihiko; Teshima, Kousuke; Tachida, Hidenori; Kusumi, Junko

    2016-01-01

    PREMISE OF THE STUDY: Studies of natural genetic variation can elucidate the genetic basis of phenotypic variation and the past population structure of species. Our study species, Taxodium distichum, is a unique conifer that inhabits the flood plains and swamps of North America. Morphological and ecological differences in two varieties, T. distichum var. distichum (bald cypress) and T. distichum var. imbricarium (pond cypress), are well known, but little is known about the level of genetic differentiation between the varieties and the demographic history of local populations.METHODS: We analyzed nucleotide polymorphisms at 47 nuclear loci from 96 individuals collected from the Mississippi River Alluvial Valley (MRAV), and Gulf Coastal populations in Texas, Louisiana, and Florida using high-throughput DNA sequencing. Standard population genetic statistics were calculated, and demographic parameters were estimated using a composite-likelihood approach.KEY RESULTS: Taxodium distichum in North America can be divided into at least three genetic groups, bald cypress in the MRAV and Texas, bald cypress in Florida, and pond cypress in Florida. The levels of genetic differentiation among the groups were low but significant. Several loci showed the signatures of positive selection, which might be responsible for local adaptation or varietal differentiation.CONCLUSIONS: Bald cypress was genetically differentiated into two geographical groups, and the boundary was located between the MRAV and Florida. This differentiation could be explained by population expansion from east to west. Despite the overlap of the two varieties’ ranges, they were genetically differentiated in Florida. The estimated demographic parameters suggested that pond cypress split from bald cypress during the late Miocene.

  4. Comprehensive Characterization of HIV-1 Molecular Epidemiology and Demographic History in the Brazilian Region Most Heavily Affected by AIDS.

    Science.gov (United States)

    Gräf, Tiago; Machado Fritsch, Hegger; de Medeiros, Rúbia Marília; Maletich Junqueira, Dennis; Esteves de Matos Almeida, Sabrina; Pinto, Aguinaldo Roberto

    2016-09-15

    The high incidence of AIDS cases and the dominance of HIV-1 subtype C infections are two features that distinguish the HIV-1 epidemic in the two southernmost Brazilian states (Rio Grande do Sul [RS] and Santa Catarina [SC]) from the epidemic in other parts of the country. Nevertheless, previous studies on HIV molecular epidemiology were conducted mainly in capital cities, and a more comprehensive understanding of factors driving this unique epidemic in Brazil is necessary. Blood samples were collected from individuals in 13 municipalities in the Brazilian southern region. HIV-1 env and pol genes were submitted to phylogenetic analyses for assignment of subtype, and viral population phylodynamics were reconstructed by applying Skygrid and logistic coalescent models in a Bayesian analysis. A high prevalence of subtype C was observed in all sampled locations; however, an increased frequency of recombinant strains was found in RS, with evidence for new circulating forms (CRFs). In the SC state, subtype B and C epidemics were associated with distinct exposure groups. Although logistic models estimated similar growth rates for HIV-1 subtype C (HIV-1C) and HIV-1B, a Skygrid plot reveals that the former epidemic has been expanding for a longer time. Our results highlight a consistent expansion of HIV-1C in south Brazil, and we also discuss how heterosexual and men who have sex with men (MSM) transmission chains might have impacted the current prevalence of HIV-1 subtypes in this region. The AIDS epidemic in south Brazil is expanding rapidly, but the circumstances driving this condition are not well known. A high prevalence of HIV-1 subtype C was reported in the capital cities of this region, in contrast to the subtype B dominance in the rest of the country. This study sought to comparatively investigate the HIV-1 subtype B and C epidemics by sampling individuals from several cities in the two states with the highest AIDS incidences in Brazil. Our analyses showed distinct

  5. Identity and diversity of coral endosymbionts (zooxanthellae) from three Palauan reefs with contrasting bleaching, temperature and shading histories.

    Science.gov (United States)

    Fabricius, K E; Mieog, J C; Colin, P L; Idip, D; van Oppen, M J H

    2004-08-01

    The potential of corals to associate with more temperature-tolerant strains of algae (zooxanthellae, Symbiodinium) can have important implications for the future of coral reefs in an era of global climate change. In this study, the genetic identity and diversity of zooxanthellae was investigated at three reefs with contrasting histories of bleaching mortality, water temperature and shading, in the Republic of Palau (Micronesia). Single-stranded conformation polymorphism and sequence analysis of the ribosomal DNA internal transcribed spacer (ITS)1 region was used for genotyping. A chronically warm but partly shaded coral reef in a marine lake that is hydrographically well connected to the surrounding waters harboured only two single-stranded conformation polymorphism profiles (i.e. zooxanthella communities). It consisted only of Symbiodinium D in all 13 nonporitid species and two Porites species investigated, with the remaining five Porites harbouring C*. Despite the high temperature in this lake (> 0.5 degrees above ambient), this reef did not suffer coral mortality during the (1998) bleaching event, however, no bleaching-sensitive coral families and genera occur in the coral community. This setting contrasts strongly with two other reefs with generally lower temperatures, in which 10 and 12 zooxanthella communities with moderate to low proportions of clade D zooxanthellae were found. The data indicate that whole coral assemblages, when growing in elevated seawater temperatures and at reduced irradiance, can be composed of colonies associated with the more thermo-tolerant clade D zooxanthellae. Future increases in seawater temperature might, therefore, result in an increasing prevalence of Symbiodinium phylotype D in scleractinian corals, possibly associated with a loss of diversity in both zooxanthellae and corals. Copyright 2004 Blackwell Publishing Ltd

  6. Do arbuscular mycorrhizal fungi with contrasting life-history strategies differ in their responses to repeated defoliation?

    Science.gov (United States)

    Ijdo, Marleen; Schtickzelle, Nicolas; Cranenbrouck, Sylvie; Declerck, Stéphane

    2010-04-01

    Arbuscular mycorrhizal (AM) fungi obligatorily depend on carbon (C) resources provided via the plant and therefore fluctuations in C availability may strongly and differently affect AM fungi with different life-history strategies (LHS). In the present study, we examined the effect of repeated defoliation of in vitro grown barrel medic (Medicago truncatula) on the spore and auxiliary cell (AC) production dynamics of a presumed r-strategist (Glomus intraradices) and a presumed K-strategist (Dentiscutata reticulata). Glomus intraradices modulated the production of spores directly to C availability, showing direct investment in reproduction as expected for r-strategists. In contrast, AC production of D. reticulata was not affected after a single defoliation and thus showed higher resistance to fluctuating C levels, as expected for K-strategists. Our results demonstrate that plant defoliation affects the production of extraradical C storage structures of G. intraradices and D. reticulata differently. Our results contribute towards revealing differences in LHS among AM fungal species, a step further towards understanding their community dynamics in natural ecosystems and agroenvironments.

  7. The Natural History of Kidney Graft Cortical Microcirculation Determined by Real-Time Contrast-Enhanced Sonography (RT-CES).

    Science.gov (United States)

    Jiménez, Carlos; López, María Ovidia; Ros, Amaia; Aguilar, Ana; Menendez, David; Rivas, Begoña; Santana, María José; Vaca, Marco Antonio; Escuin, Fernando; Madero, Rosario; Selgas, Rafael

    2016-01-01

    Kidney transplantation is the therapy of choice for end-stage kidney disease. Graft's life span is shorter than expected due in part to the delayed diagnosis of various complications, specifically those related to silent progression. It is recognized that serum creatinine levels and proteinuria are poor markers of mild kidney lesions, which results in delayed clinical information. There are many investigation looking for early markers of graft damage. Decreasing kidney graft cortical microcirculation has been related to poor prognosis in kidney transplantation. Cortical capillary blood flow (CCBF) can be measured by real-time contrast-enhanced sonography (RT-CES). Our aim was to describe the natural history of CCBF over time under diverse conditions of kidney transplantation, to explore the influence of donor conditions and recipient events, and to determine the capacity of CCBF for predicting renal function in medium term. RT-CES was performed in 79 consecutive kidney transplant recipients during the first year under regular clinical practice. Cortical capillary blood flow was measured. Clinical variables were analyzed. The influence of CCBF has been determined by univariate and multivariate analysis using mixed regression models based on sequential measurements for each patient over time. We used a first-order autoregression model as the structure of the covariation between measures. The post-hoc comparisons were considered using the Bonferroni correction. The CCBF values varied significantly over the study periods and were significantly lower at 48 h and day 7. Brain-death donor age and CCBF levels showed an inverse relationship (r: -0.62, p<0.001). Living donors showed higher mean CCBF levels than brain-death donors at each point in the study. These significant differences persisted at month 12 (54.5 ± 28.2 vs 33.7 ± 30 dB/sec, living vs brain-death donor, respectively, p = 0.004) despite similar serum creatinine levels (1.5 ± 0.3 and 1.5 ± 0.5 mg/dL). A

  8. Queer diagnoses: parallels and contrasts in the history of homosexuality, gender variance, and the diagnostic and statistical manual.

    Science.gov (United States)

    Drescher, Jack

    2010-04-01

    The American Psychiatric Association (APA) is in the process of revising its Diagnostic and Statistical Manual (DSM), with the DSM-V having an anticipated publication date of 2012. As part of that ongoing process, in May 2008, APA announced its appointment of the Work Group on Sexual and Gender Identity Disorders (WGSGID). The announcement generated a flurry of concerned and anxious responses in the lesbian, gay, bisexual, and transgender (LGBT) community, mostly focused on the status of the diagnostic categories of Gender Identity Disorder (GID) (for both children and adolescents and adults). Activists argued, as in the case of homosexuality in the 1970s, that it is wrong to label expressions of gender variance as symptoms of a mental disorder and that perpetuating DSM-IV-TR's GID diagnoses in the DSM-V would further stigmatize and cause harm to transgender individuals. Other advocates in the trans community expressed concern that deleting GID would lead to denying medical and surgical care for transgender adults. This review explores how criticisms of the existing GID diagnoses parallel and contrast with earlier historical events that led APA to remove homosexuality from the DSM in 1973. It begins with a brief introduction to binary formulations that lead not only to linkages of sexual orientation and gender identity, but also to scientific and clinical etiological theories that implicitly moralize about matters of sexuality and gender. Next is a review of the history of how homosexuality came to be removed from the DSM-II in 1973 and how, not long thereafter, the GID diagnoses found their way into DSM-III in 1980. Similarities and differences in the relationships of homosexuality and gender identity to psychiatric and medical thinking are elucidated. Following a discussion of these issues, the author recommends changes in the DSM-V and some internal and public actions that the American Psychiatric Association should take.

  9. Population structure analyses and demographic history of the malaria vector Anopheles albimanus from the Caribbean and the Pacific regions of Colombia

    Directory of Open Access Journals (Sweden)

    Conn Jan E

    2009-11-01

    Full Text Available Abstract Background Anopheles albimanus is an important malaria vector in some areas throughout its distribution in the Caribbean and the Pacific regions of Colombia, covering three biogeographic zones of the neotropical region, Maracaibo, Magdalena and Chocó. Methods This study was conducted to estimate intra-population genetic diversity, genetic differentiation and demographic history of An. albimanus populations because knowledge of vector population structure is a useful tool to guide malaria control programmes. Analyses were based on mtDNA COI gene sequences and four microsatellite loci of individuals collected in eight populations from the Caribbean and the Pacific regions of Colombia. Results Two distinctive groups were consistently detected corresponding to COI haplotypes from each region. A star-shaped statistical parsimony network, significant and unimodal mismatch distribution, and significant negative neutrality tests together suggest a past demographic expansion or a selective sweep in An. albimanus from the Caribbean coast approximately 21,994 years ago during the late Pleistocene. Overall moderate to low genetic differentiation was observed between populations within each region. However, a significant level of differentiation among the populations closer to Buenaventura in the Pacific region was observed. The isolation by distance model best explained genetic differentiation among the Caribbean region localities: Los Achiotes, Santa Rosa de Lima and Moñitos, but it could not explain the genetic differentiation observed between Turbo (Magdalena providence, and the Pacific region localities (Nuquí, Buenaventura, Tumaco. The patterns of differentiation in the populations from the different biogeographic provinces could not be entirely attributed to isolation by distance. Conclusion The data provide evidence for limited past gene flow between the Caribbean and the Pacific regions, as estimated by mtDNA sequences and current gene

  10. Patterns of variation at Ustilago maydis virulence clusters 2A and 19A largely reflect the demographic history of its populations.

    Directory of Open Access Journals (Sweden)

    Ronny Kellner

    Full Text Available The maintenance of an intimate interaction between plant-biotrophic fungi and their hosts over evolutionary times involves strong selection and adaptative evolution of virulence-related genes. The highly specialised maize pathogen Ustilago maydis is assigned with a high evolutionary capability to overcome host resistances due to its high rates of sexual recombination, large population sizes and long distance dispersal. Unlike most studied fungus-plant interactions, the U. maydis - Zea mays pathosystem lacks a typical gene-for-gene interaction. It exerts a large set of secreted fungal virulence factors that are mostly organised in gene clusters. Their contribution to virulence has been experimentally demonstrated but their genetic diversity within U. maydis remains poorly understood. Here, we report on the intraspecific diversity of 34 potential virulence factor genes of U. maydis. We analysed their sequence polymorphisms in 17 isolates of U. maydis from Europe, North and Latin America. We focused on gene cluster 2A, associated with virulence attenuation, cluster 19A that is crucial for virulence, and the cluster-independent effector gene pep1. Although higher compared to four house-keeping genes, the overall levels of intraspecific genetic variation of virulence clusters 2A and 19A, and pep1 are remarkably low and commensurate to the levels of 14 studied non-virulence genes. In addition, each gene is present in all studied isolates and synteny in cluster 2A is conserved. Furthermore, 7 out of 34 virulence genes contain either no polymorphisms or only synonymous substitutions among all isolates. However, genetic variation of clusters 2A and 19A each resolve the large scale population structure of U. maydis indicating subpopulations with decreased gene flow. Hence, the genetic diversity of these virulence-related genes largely reflect the demographic history of U. maydis populations.

  11. Genetic Structure and Demographic History Reveal Migration of the Diamondback Moth Plutella xylostella (Lepidoptera: Plutellidae) from the Southern to Northern Regions of China

    Science.gov (United States)

    Wei, Shu-Jun; Shi, Bao-Cai; Gong, Ya-Jun; Jin, Gui-Hua; Chen, Xue-Xin; Meng, Xiang-Feng

    2013-01-01

    The diamondback moth Plutella xylostella (Linnaeus) (Lepidoptera: Plutellidae) is one of the most destructive insect pests of cruciferous plants worldwide. Biological, ecological and genetic studies have indicated that this moth is migratory in many regions around the world. Although outbreaks of this pest occur annually in China and cause heavy damage, little is known concerning its migration. To better understand its migration pattern, we investigated the population genetic structure and demographic history of the diamondback moth by analyzing 27 geographical populations across China using four mitochondrial genes and nine microsatellite loci. The results showed that high haplotype diversity and low nucleotide diversity occurred in the diamondback moth populations, a finding that is typical for migratory species. No genetic differentiation among all populations and no correlation between genetic and geographical distance were found. However, pairwise analysis of the mitochondrial genes has indicated that populations from the southern region were more differentiated than those from the northern region. Gene flow analysis revealed that the effective number of migrants per generation into populations of the northern region is very high, whereas that into populations of the southern region is quite low. Neutrality testing, mismatch distribution and Bayesian Skyline Plot analyses based on mitochondrial genes all revealed that deviation from Hardy-Weinberg equilibrium and sudden expansion of the effective population size were present in populations from the northern region but not in those from the southern region. In conclusion, all our analyses strongly demonstrated that the diamondback moth migrates within China from the southern to northern regions with rare effective migration in the reverse direction. Our research provides a successful example of using population genetic approaches to resolve the seasonal migration of insects. PMID:23565158

  12. Contrasting neogene denudation histories of different structural regions in the transantarctic mountains rift flank constrained by cosmogenic isotope measurements

    NARCIS (Netherlands)

    Wateren, F.M. van der; Dunai, T.J.; Balen, R.T. van; Klas, W.; Verbers, A.L.L.M.; Passchier, S.; Herpers, U.

    1999-01-01

    Separate regions within the Transantarctic Mountains, the uplifted flank of the West Antarctic rift system, appear to have distinct Neogene histories of glaciation and valley downcutting. Incision of deep glacial outlet valleys occurred at different times throughout central and northern Victoria

  13. Demographic consequences of climate change and land cover help explain a history of extirpations and range contraction in a declining snake species.

    Science.gov (United States)

    Pomara, Lars Y; LeDee, Olivia E; Martin, Karl J; Zuckerberg, Benjamin

    2014-07-01

    Developing conservation strategies for threatened species increasingly requires understanding vulnerabilities to climate change, in terms of both demographic sensitivities to climatic and other environmental factors, and exposure to variability in those factors over time and space. We conducted a range-wide, spatially explicit climate change vulnerability assessment for Eastern Massasauga (Sistrurus catenatus), a declining endemic species in a region showing strong environmental change. Using active season and winter adult survival estimates derived from 17 data sets throughout the species' range, we identified demographic sensitivities to winter drought, maximum precipitation during the summer, and the proportion of the surrounding landscape dominated by agricultural and urban land cover. Each of these factors was negatively associated with active season adult survival rates in binomial generalized linear models. We then used these relationships to back-cast adult survival with dynamic climate variables from 1950 to 2008 using spatially explicit demographic models. Demographic models for 189 population locations predicted known extant and extirpated populations well (AUC = 0.75), and models based on climate and land cover variables were superior to models incorporating either of those effects independently. These results suggest that increasing frequencies and severities of extreme events, including drought and flooding, have been important drivers of the long-term spatiotemporal variation in a demographic rate. We provide evidence that this variation reflects nonadaptive sensitivity to climatic stressors, which are contributing to long-term demographic decline and range contraction for a species of high-conservation concern. Range-wide demographic modeling facilitated an understanding of spatial shifts in climatic suitability and exposure, allowing the identification of important climate refugia for a dispersal-limited species. Climate change vulnerability

  14. Changing demographics

    International Nuclear Information System (INIS)

    Vetter, B.M.

    1991-01-01

    This paper reports on changing population demographics, poor academic preparation for and a decreasing interest in engineering among college students which indicates possible shortages ahead, particularly among chemical and petroleum engineers. The talent pool for engineering must be enlarged to include women and minority men, if we are to ensure an adequate future supply for the U.S

  15. Relationship between the natural history of chronic subdural hematoma and enhancement of the inner membrane on post-contrast CT scan

    Energy Technology Data Exchange (ETDEWEB)

    Nakaguchi, Hiroshi; Yoshimasu, Norio [Teraoka Memorial Hospital, Shinichi, Hiroshima (Japan); Tanishima, Takeo [Tokyo Kosei Nenkin Hospital (Japan)

    2003-02-01

    The purpose of this study was to determine the features and natural history of the inner membrane in CSDH (chronic subdural hemotoma) patients using pre- and post-contrast CT scans. Twenty-four patients with CSDH (28 hematomas) who underwent pre- and post-contrast CT scanning prior to surgery ware studied. CSDH was classified according to the internal architecture as the homogeneous (HM) type, the laminar (LM) type, the separated (SP) type, and the trabecular (TR) type. For each type, the enhancement of the inner membrane, the outer membrane, and trabeculae was evaluated. Enhancement of the inner membrane develops as the stage of CSDH progresses. Although the inner membrane was not enhanced in the HM type, it was enhanced in almost all of the patients with the other types (p <0.0001). In 13% of patients with the LM type, 29% with the SP type, and 40% with the TR type, the inner membrane was moderately or markedly enhanced. The outer membrane was not thickened in any patient. In 88% of the patients who had contralateral hemiparesis on admission and 42% of those who did not have hemiparesis, the inner membrane was clearly enhanced (p=0.0166). This indicated that blood flow to the inner membrane from the pia matter induced hypoperfusion of the brain parenchyma beneath the hematoma in addition to the effect of direct compression. Contrast CT scanning may be useful for diagnosing the extent of enlargement of the inner membrane, predicting the risk of local brain damage, and evaluating the stage in the natural history of CSDH. (author)

  16. Relationship between the natural history of chronic subdural hematoma and enhancement of the inner membrane on post-contrast CT scan

    International Nuclear Information System (INIS)

    Nakaguchi, Hiroshi; Yoshimasu, Norio; Tanishima, Takeo

    2003-01-01

    The purpose of this study was to determine the features and natural history of the inner membrane in CSDH (chronic subdural hematoma) patients using pre- and post-contrast CT scans. Twenty-four patients with CSDH (28 hematomas) who underwent pre- and post-contrast CT scanning prior to surgery ware studied. CSDH was classified according to the internal architecture as the homogeneous (HM) type, the laminar (LM) type, the separated (SP) type, and the trabecular (TR) type. For each type, the enhancement of the inner membrane, the outer membrane, and trabeculae was evaluated. Enhancement of the inner membrane develops as the stage of CSDH progresses. Although the inner membrane was not enhanced in the HM type, it was enhanced in almost all of the patients with the other types (p <0.0001). In 13% of patients with the LM type, 29% with the SP type, and 40% with the TR type, the inner membrane was moderately or markedly enhanced. The outer membrane was not thickened in any patient. In 88% of the patients who had contralateral hemiparesis on admission and 42% of those who did not have hemiparesis, the inner membrane was clearly enhanced (p=0.0166). This indicated that blood flow to the inner membrane from the pia matter induced hypoperfusion of the brain parenchyma beneath the hematoma in addition to the effect of direct compression. Contrast CT scanning may be useful for diagnosing the extent of enlargement of the inner membrane, predicting the risk of local brain damage, and evaluating the stage in the natural history of CSDH. (author)

  17. Phylogeography and Demographic History of Chinese Black-Spotted Frog Populations (Pelophylax nigromaculata: Evidence for Independent Refugia Expansion and Secondary Contact

    Directory of Open Access Journals (Sweden)

    Zhou Kaiya

    2008-01-01

    Full Text Available Abstract Background Pleistocene glaciations had considerable impact on phylogeographic patterns within and among closely related species of many vertebrates. Compared to Europe and North America, research on the phylogeography of vertebrates in East Asia, particularly in China, remains limited. The black-spotted frog (Pelophylax nigromaculata is a widespread species in East Asia. The wide distribution of this species in China makes it an ideal model for the study of palaeoclimatic effects on vertebrates in East Asia. Our previous studies of P. nigromaculata revealed significant subdivisions between the northeast China populations and populations in other regions of the mainland. In the present study, we aim to see whether the deepest splits among lineages and perhaps subsequent genealogical divisions are temporally consistent with a Pleistocene origin and whether clade geographic distributions, with insight into expansion patterns, are similarly spatially consistent with this model. Results Using 1143 nucleotides of the mitochondrial cytochrome b gene from 262 individuals sampled from 28 localities, two main clades (clade A and clade B differing by c. 7.72% sequence divergence were defined from parsimony analyses. The corresponding timing of lineage divergence, 0.92 Mya, indicates a most likely Pleistocene split. The A clade is further subdivided into two sub-clades, A1 and A2 with 1.22% sequence divergence. Nested clade phylogeographical and population demographic analyses suggested that the current distribution of this frog species was the result of range expansion from two independent refugia during the last interglacial period. We discovered a population within which haplotype lineages A and B of P. nigromaculata coexist in the Dongliao area of China by nucleotide sequences, PCR-RFLP and ISSR (inter simple sequence repeat patterns. The ISSR result in particular supported divergence between the mitochondrial clades A and B and implied

  18. Population genetic structure and demographic history of the freshwater crab Potamon elbursi (Brachyura: Potamidae from the Alborz Mountains in northern Iran

    Directory of Open Access Journals (Sweden)

    Alireza Keikhosravi

    2015-04-01

    Full Text Available Hydrographically separated populations of the freshwater crab Potamon elbursi Pretzmann, 1976 were genetically investigated to assess their local diversity and to reconstruct the possible role of Quaternary glaciations in shaping current diversity in the Alborz Mountains, northern Iran. A total of 61 specimens from six rivers were collected from the two different drainage systems of the Alborz Mountains, Namak Lake and the South Caspian watershed. A comparative analysis of a partial sequence of the mitochondrial cytochrome oxidase subunit I gene revealed relatively high overall haplotype diversity and low nucleotide diversity. In four populations, there is no association between the haplotype network and the geographical separation between drainages, whereas the remaining two populations consist of private haplotypes. Gene flow among rivers was estimated using pairwise differences of Φst; in almost all cases gene flow was significantly restricted, regardless of association to a particular river system. Surprisingly, the only exception was the pairwise comparison of two distant rivers belonging to different drainages; this lack of differentiation may be attributed to incomplete lineage sorting or secondary introduction events. The mismatch distribution analysis, together with the shape of the haplotype network and the nucleotide and haplotype diversity indices, indicates that the studied metapopulation show the signature of recent population bottlenecks followed by demographic or spatial expansion and dating back to Pleistocene climatic fluctuations. 

  19. Genetic Structure and Population Demographic History of a Widespread Mangrove Plant Xylocarpus granatum J. Koenig across the Indo-West Pacific Region

    Directory of Open Access Journals (Sweden)

    Yuki Tomizawa

    2017-12-01

    Full Text Available Xylocarpus granatum J. Koenig is one of the most widespread core component species of mangrove forests in the Indo-West Pacific (IWP region, and as such is suitable for examining how genetic structure is generated across spatiotemporal scales. We evaluated the genetic structure of this species using maternally inherited chloroplast (cp and bi-parentally inherited nuclear DNA markers, with samples collected across the species range. Both cp and nuclear DNA showed generally similar patterns, revealing three genetic groups in the Indian Ocean, South China Sea (with Palau, and Oceania, respectively. The genetic diversity of the Oceania group was significantly lower, and the level of population differentiation within the Oceania group was significantly higher, than in the South China Sea group. These results revealed that in addition to the Malay Peninsula—a common land barrier for mangroves—there is a genetic barrier in an oceanic region of the West Pacific that prevents gene flow among populations. Moreover, demographic inference suggested that these patterns were generated in relation to sea level changes during the last glacial period and the emergence of Sahul Shelf which lied northwest of Australia. We propose that the three genetic groups should be considered independent conservation units, and that the Oceania group has a higher conservation priority.

  20. Genetic Population Structure and Demographic History of the Widespread Common Shipworm Teredo navalis Linnaeus 1758 (Mollusca: Bivalvia: Teredinidae in European Waters Inferred from Mitochondrial COI Sequence Data

    Directory of Open Access Journals (Sweden)

    Ronny Weigelt

    2017-06-01

    Full Text Available The first documented scientific reports of the common marine shipworm Teredo navalis (Bivalvia for Central European waters date back to the time between 1700 and 1730 in the Netherlands. During the following centuries there were several irregular mass occurrences reported for both the North Sea and the Baltic Sea. These events were accompanied by massive destruction of wooden ships and coastal protection structures. In this study, the first population analysis of T. navalis is presented with the aim to detect the genetic population structure in the waters of Central Europe. The mtDNA COI (cytochrome c oxidase subunit I locus was found as suitable molecular marker and hence a 675 bp gene fragment was studied. A total of 352 T. navalis specimens from 13 different sampling sites distributed across Central Europe were examined. Subsequently, various population genetic indices including FST values and an AMOVA analysis were applied for the description of the population structure. To visualize the distribution of haplotypes at the different sampling sites two median-joining networks were calculated. In addition, the past demographic structure of the T. navalis population was analyzed, among others by calculating Tajima's D, Fu's F and the mismatch distribution. Finally, all computations of the population genetic indices could not reveal differentiated populations or any kind of distinct population structure in T. navalis. The network analyses revealed “star-like” patterns without differentiated substructures or demes. Therefore, it can be assumed that a sudden expansion of this species took place without any indications of neither a bottleneck nor a founder effect for the study area. The results of this study support the concept of a regional panmictic population in the waters of Central Europe with unhindered migration of individuals (e.g., via pelagic larvae between the various sampling sites as reflected by a high gene flow.

  1. Genetic Diversity and Demographic History of Wild and Cultivated/Naturalised Plant Populations: Evidence from Dalmatian Sage (Salvia officinalis L., Lamiaceae)

    Science.gov (United States)

    Rešetnik, Ivana; Baričevič, Dea; Batîr Rusu, Diana; Carović-Stanko, Klaudija; Chatzopoulou, Paschalina; Dajić-Stevanović, Zora; Gonceariuc, Maria; Grdiša, Martina; Greguraš, Danijela; Ibraliu, Alban; Jug-Dujaković, Marija; Krasniqi, Elez; Liber, Zlatko; Murtić, Senad; Pećanac, Dragana; Radosavljević, Ivan; Stefkov, Gjoshe; Stešević, Danijela; Šoštarić, Ivan; Šatović, Zlatko

    2016-01-01

    Dalmatian sage (Salvia officinalis L., Lamiaceae) is a well-known aromatic and medicinal Mediterranean plant that is native in coastal regions of the western Balkan and southern Apennine Peninsulas and is commonly cultivated worldwide. It is widely used in the food, pharmaceutical and cosmetic industries. Knowledge of its genetic diversity and spatiotemporal patterns is important for plant breeding programmes and conservation. We used eight microsatellite markers to investigate evolutionary history of indigenous populations as well as genetic diversity and structure within and among indigenous and cultivated/naturalised populations distributed across the Balkan Peninsula. The results showed a clear separation between the indigenous and cultivated/naturalised groups, with the cultivated material originating from one restricted geographical area. Most of the genetic diversity in both groups was attributable to differences among individuals within populations, although spatial genetic analysis of indigenous populations indicated the existence of isolation by distance. Geographical structuring of indigenous populations was found using clustering analysis, with three sub-clusters of indigenous populations. The highest level of gene diversity and the greatest number of private alleles were found in the central part of the eastern Adriatic coast, while decreases in gene diversity and number of private alleles were evident towards the northwestern Adriatic coast and southern and eastern regions of the Balkan Peninsula. The results of Ecological Niche Modelling during Last Glacial Maximum and Approximate Bayesian Computation suggested two plausible evolutionary trajectories: 1) the species survived in the glacial refugium in southern Adriatic coastal region with subsequent colonization events towards northern, eastern and southern Balkan Peninsula; 2) species survived in several refugia exhibiting concurrent divergence into three genetic groups. The insight into genetic

  2. Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats, India: implications for conservation in a biodiversity hotspot.

    Science.gov (United States)

    Bodare, Sofia; Tsuda, Yoshiaki; Ravikanth, Gudasalamani; Uma Shaanker, Ramanan; Lascoux, Martin

    2013-09-01

    The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range-wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species' evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old-growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (F IS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation-based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies.

  3. Genetic structure and demographic history of the endangered tree species Dysoxylum malabaricum (Meliaceae) in Western Ghats, India: implications for conservation in a biodiversity hotspot

    Science.gov (United States)

    Bodare, Sofia; Tsuda, Yoshiaki; Ravikanth, Gudasalamani; Uma Shaanker, Ramanan; Lascoux, Martin

    2013-01-01

    The impact of fragmentation by human activities on genetic diversity of forest trees is an important concern in forest conservation, especially in tropical forests. Dysoxylum malabaricum (white cedar) is an economically important tree species, endemic to the Western Ghats, India, one of the world's eight most important biodiversity hotspots. As D. malabaricum is under pressure of disturbance and fragmentation together with overharvesting, conservation efforts are required in this species. In this study, range-wide genetic structure of twelve D. malabaricum populations was evaluated to assess the impact of human activities on genetic diversity and infer the species’ evolutionary history, using both nuclear and chloroplast (cp) DNA simple sequence repeats (SSR). As genetic diversity and population structure did not differ among seedling, juvenile and adult age classes, reproductive success among the old-growth trees and long distance seed dispersal by hornbills were suggested to contribute to maintain genetic diversity. The fixation index (FIS) was significantly correlated with latitude, with a higher level of inbreeding in the northern populations, possibly reflecting a more severe ecosystem disturbance in those populations. Both nuclear and cpSSRs revealed northern and southern genetic groups with some discordance of their distributions; however, they did not correlate with any of the two geographic gaps known as genetic barriers to animals. Approximate Bayesian computation-based inference from nuclear SSRs suggested that population divergence occurred before the last glacial maximum. Finally we discussed the implications of these results, in particular the presence of a clear pattern of historical genetic subdivision, on conservation policies. PMID:24223264

  4. Contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure

    International Nuclear Information System (INIS)

    Barbosa, Fernando; Ramires, Irene; Rodrigues, Maria Heloisa C.; Saint' Pierre, Tatiana D.; Curtius, Adilson J.; Buzalaf, Marilia R.; Gerlach, Raquel F.; Tanus-Santos, Jose E.

    2006-01-01

    We examined the effect of age and sex on the relationship between the concentrations of Pb in blood (Pb-B) and in plasma (Pb-P) in an adult population with a history of lead exposure. Pb-P was determined by inductively coupled plasma mass spectrometry (ICP-MS) and Pb-B by graphite furnace atomic absorption spectrometry (GF AAS). We studied 154 adults (56 men and 98 women) from 18 to 60-year old. Pb-B levels varied from 10.0 to 428.0 μg/L, with a mean of 76 μg/L. Blood lead levels varied from 10.0 to 428.0 μg/L in men (mean, 98.3 μg/L) and from 10.0 to 263.0 μg/L (mean, 62.8 μg/L) in women. Corresponding Pb-Ps were 0.02-2.9 μg/L (mean, 0.66 μg/L) and 0.02-1.5 μg/L (mean, 0.42 μg/L) in men and women, respectively. The relationship between Pb-B and Pb-P was found to be curvilinear (r=0.757, P 1492 (y=Pb-P, and x=Pb-B). The %Pb-P/Pb-B ratio ranged from 0.03% to 1.85%. A positive association was found between %Pb-P/Pb-B ratio and Pb-B levels. When data were separated by sex, this association was also relevant for men (y=0.0184x 0.702 ) and women (y=0.0534x 0.5209 ) (y=%Pb-P/Pb-B and x=Pb-B). Moreover, we found an interesting positive correlation between Log (Pb-P/Pb-B) and age for women (r=0.31, P<0.0001) and a negative correlation for men (r=-0.164, P=0.07). Taken together, these results suggest contrasting effects of age on the plasma/whole blood lead ratio in men and women with a history of lead exposure. Moreover, sex might play an important role in the metabolism of lead, implying further consideration on the kinetic models constructed of lead toxicity

  5. Contrast Materials

    Science.gov (United States)

    ... is mixed with water before administration liquid paste tablet When iodine-based and barium-sulfate contrast materials ... for patients with kidney failure or allergies to MRI and/or computed tomography (CT) contrast material. Microbubble ...

  6. Contrasting population and life history responses of a young morph-pair of European whitefish to the invasion of a specialised coregonid competitor, vendace.

    Directory of Open Access Journals (Sweden)

    Odd Terje Sandlund

    Full Text Available Invasions of non-native species represent a global problem of great scientific interest. Here we study in detail the response in population and life history characteristics of closely related native species, with divergent habitat preferences, that are impacted by an invading species over a sufficient time period to allow a new stable state to become established. A time series of 20 years starting at the first occurrence of the invader (vendace Coregonus albula (L. allows exploration of the long term population and life history response of two ecologically, morphologically, and genetically different native sympatric morphs (DR- and SR- of congeneric whitefish C. lavaretus (L.. The whitefish morphs are taxonomically equally related to the invading vendace, but only the planktivorous DR-whitefish share its pelagic niche. We would expect that the ecological differences between the whitefish morphs may be used as a predictor of competitive effects. Vendace exhibited an initial boom-and-bust development, and has continued to fluctuate in density. The responses of the pelagic DR-whitefish were: i an immediate habitat shift, ii a subsequent population decline caused by increased annual mortality, and iii a new stable state at a lower density and apparently relaxed competition. The ecologically more distant benthivorous SR-whitefish also showed significant, but a much more limited response during this process, indicating damped indirect interactions through the food-web. This long-term case-study found that in two native eco-species equally related to the invader, only one of the eco-species was highly affected. Direct competition for resources is obviously important for species interactions, whereas the taxonomic relatedness per se seems to offer little predictive power for invasion effects.

  7. Dancing with Demographers.

    Science.gov (United States)

    Robertson, Heather-Jane

    2000-01-01

    Demographic projections concerning the shortage of teachers in Canada, their pay scale, the feminization of teaching, the gender gap in salaries, and teacher autonomy have often been incorrect, or correct for the wrong reasons. Instead of relying on demographic predictions, teachers should contemplate who they really want to be professionally,…

  8. Geographic structure of genetic variation in the widespread woodland grass Milium effusum L. A comparison between two regions with contrasting history and geomorphology.

    Science.gov (United States)

    Tyler, Torbjörn

    2002-12-01

    Allozyme variation in the forest grass Milium effusum L. was studied in 21-23 populations within each of two equally sized densely sampled areas in northern and southern Sweden. In addition, 25 populations from other parts of Eurasia were studied for comparison. The structure of variation was analysed with both diversity statistics and measures based on allelic richness at a standardised sample size. The species was found to be highly variable, but no clear geographic patterns in the distribution of alleles or in overall genetic differentiation were found, either within the two regions or within the whole sample. Thus, no inferences about the direction of postglacial migration could be made. Obviously, migration and gene flow must have taken place in a manner capable of randomising the distribution of alleles. However, there were clear differences in levels and structuring of the variation between the two regions. Levels of variation, both in terms of genetic diversity and allelic richness, were lower in northern Sweden as compared with southern Sweden. In contrast, different measures of geographic structure all showed higher levels of population differentiation in the northern region. This is interpreted as due to different geomorphological conditions in the two regions, creating a relatively continuous habitat and gene flow in the southern region as compared with the northern region where the species, although common, is confined to narrow and mutually isolated corridors in the landscape.

  9. Myocardial Fibrosis in Competitive Triathletes Detected by Contrast-Enhanced CMR Correlates With Exercise-Induced Hypertension and Competition History.

    Science.gov (United States)

    Tahir, Enver; Starekova, Jitka; Muellerleile, Kai; von Stritzky, Alexandra; Münch, Julia; Avanesov, Maxim; Weinrich, Julius M; Stehning, Christian; Bohnen, Sebastian; Radunski, Ulf K; Freiwald, Eric; Blankenberg, Stefan; Adam, Gerhard; Pressler, Axel; Patten, Monica; Lund, Gunnar K

    2017-12-08

    This study analyzed the presence of myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiac magnetic resonance (CMR) in correlation with the performance of competitive triathletes objectified by an exercise test and individual competition history. Myocardial fibrosis detected by LGE CMR has been reported to occur in 0% to 50% of asymptomatic athletes. However, the cause and mechanisms of myocardial fibrosis are unclear. Eighty-three asymptomatic triathletes undergoing >10 training h per week (43 ± 10 years of age; 65% male) and 36 sedentary controls were studied by using LGE and extracellular volume (ECV) CMR. Parameters of physical fitness were measured by spiroergometry. Triathletes reported their lifetime competition results. LGE CMR revealed focal nonischemic myocardial fibrosis in 9 of 54 (17%) male triathletes (LGE + ) but in none of the female triathletes (p pressure (213 ± 24 mm Hg) than LGE - triathletes (194 ± 26 mm Hg; p 1,880 km completed during competition had the highest accuracy to predict LGE, with an area under the curve value of 0.876 (p pressure (p < 0.05) and the swimming race distance (p < 0.01) as independent predictors of LGE presence. Myocardial fibrosis in asymptomatic triathletes seems to be associated with exercise-induced hypertension and the race distances. There appears to be a safe upper limit, beyond which exercise may result in myocardial fibrosis. Copyright © 2017 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

  10. Genetic structure and effective population size through time: a tale on two coastal marine species with contrasting life-history patterns

    Directory of Open Access Journals (Sweden)

    Sara Martins Francisco

    2015-12-01

    Full Text Available Species with dispersal mediated by planktonic larvae are expected to be more likely to show temporal genetic variation, due to differences in larval mortality and dispersal ability. The shanny Lipophrys pholis is a typical benthic rocky intertidal fish and its dispersion is limited to its long larval stage. In contrast, the sand-smelt Atherina presbyter has a very short planktonic life, small size and weak swimming capabilities, which translates into reduced dispersion potential. A total of 226 specimens of L. pholis (collected in 2003, 2013 and 2014 and 281 of A. presbyter (collected in 2005, 2012, 2013 and 2014 were screened for genetic variation using the mitochondrial control region. Only 12 (out of 171 and 25 (out of 155 haplotypes found were shared between sampling periods for the shanny and the sand smelt, respectively. For both species, haplotype networks showed a deep genealogy with multiple levels of diversification and no temporal structure. Interestingly, some of the previously inferred missing haplotypes were sampled in more recent years. The genetic diversity indices showed little variation among sampling periods and were generally high. For L. pholis significant genetic differentiation was detected between 2013 and 2014, while no significant differences were detected between sampling periods in A. presbyter. The shanny showed lower effective population size per generation when compared to the sand-smelt (which yielded lack of evidence for genetic drift for the first and second period of the study. These results highlight the fact that temporal changes in the gene pool composition need to be considered when evaluating population structure, especially for species with long pelagic larval dispersion, more vulnerable to fluctuations in the recruitment.

  11. Family Health Histories and Their Impact on Retirement Confidence.

    Science.gov (United States)

    Zick, Cathleen D; Mayer, Robert N; Smith, Ken R

    2015-08-01

    Retirement confidence is a key social barometer. In this article, we examine how personal and parental health histories relate to working-age adults' feelings of optimism or pessimism about their overall retirement prospects. This study links survey data on retirement planning with information on respondents' own health histories and those of their parents. The multivariate models control for the respondents' socio-demographic and economic characteristics along with past retirement planning activities when estimating the relationships between family health histories and retirement confidence. Retirement confidence is inversely related to parental history of cancer and cardiovascular disease but not to personal health history. In contrast, retirement confidence is positively associated with both parents being deceased. As members of the public become increasingly aware of how genetics and other family factors affect intergenerational transmission of chronic diseases, it is likely that the link between family health histories and retirement confidence will intensify. © The Author(s) 2015.

  12. Laboratory Demographics Lookup Tool

    Data.gov (United States)

    U.S. Department of Health & Human Services — This website provides demographic information about laboratories, including CLIA number, facility name and address, where the laboratory testing is performed, the...

  13. Contrast media

    International Nuclear Information System (INIS)

    Decazes, Ph.

    2004-01-01

    The Guerbet firm, which holds 69% of the capital on the contrast media for medical imagery, could sale about 20% of this capital in order to accelerate its development in the United States, one of its next market with the Japan. (O.M.)

  14. Serbian demographers on demography

    Directory of Open Access Journals (Sweden)

    Rašević Mirjana

    2013-01-01

    Full Text Available Introduction: The objective of this paper is to collect the opinions of the leading demographers in Serbia on four significant matters. The matters are: development, state and future of demography, the successfulness of researchers in this scientific discipline, improvement of the Stanovništvo journal, as well as the population priority of our society and range of population policies. Method: A qualitative interview was chosen as the instrument for data collection. Namely, a structured interview, based on nine questions was sent by e-mail to eleven addresses of relevant demographers in the second half of October 2013. The basic reason for sending questions by e-mail was the aspiration to obtain authentic replies which require time for contemplation. Ten completed questionnaires were returned within two weeks. On the one hand, an integral picture on the chosen themes for research was attempted to be obtained in the analysis of received opinions to certain groups of questions and on the other hand to portray the spectrum of different observations. The responses of our prominent demographers were analyzed and compared to clearly pronounced standpoints of eminent demographers published in world journals on similar themes and with findings of internet researches among members of the International Union for the Scientific Study of Population. Results: The results show that there is a high level of consent among demographers in Serbia regarding the well positioning of demography in relation to other social studies and its good perspectives. The interviewed experts see the future of demography in its integration with a wide circle of sciences, the application of demography and/or greater engagement of researchers in carrying out public policies. However, the estimations of the interviewed demographers as regards the development and state of demography in Serbia are divided. Although a large number of topics had been listed, migrations and population

  15. Demographic Change and Transport

    DEFF Research Database (Denmark)

    Haustein, Sonja; Siren, Anu Kristiina; Framke, Elisabeth

    This report is the literature review on demographic changes and transport of Work Package 1 of the EU project CONSOL, “CONcerns and SOLutions – Road Safety in the Ageing Societies” (contract period: 2011-2013). The report is a state-of-the art report that combines current knowledge with new...

  16. Country Demographic Profiles: Thailand.

    Science.gov (United States)

    Bureau of the Census (DOC), Suitland, MD. Population Div.

    This profile of the population of Thailand contains 35 tables of selected demographic information, including size of population and estimates of fertility and mortality, beginning in 1950. An adjusted distribution of the population by age and sex is given for the latest census year, as well as for 1976. Projections of the number of women of…

  17. EJSCREEN Demographic Indicators 2015 Public

    Science.gov (United States)

    EJSCREEN uses demographic factors as very general indicators of a community's potential susceptibility to the types of environmental factors included in this screening tool. There are six demographic indicators: Demographic Index, Supplementary Demographic Index, Individuals under Age 5, Individuals over Age 64, Percent Low-Income, Linguistic Isolation, Percent Minority, and Less than High School Education.

  18. Retention of contrast media in the history of radiology. Sequelae of the former use of thorotrast and new challenges; Kontrastmittelretention in der Geschichte der Radiologie. Folgen der frueheren Thorotrastanwendungen und neue Herausforderungen

    Energy Technology Data Exchange (ETDEWEB)

    Kaick, G. van; Delorme, S. [Deutsches Krebsforschungszentrum (DKFZ), Heidelberg (Germany)

    2016-12-15

    Detection of gadolinium deposits in patients who have repeatedly been administered intravenous gadolinium chelates have given rise to concern regarding the long-term safety of magnetic resonance imaging (MRI) contrast media. Nevertheless, negative long-term clinical effects have not yet been observed. In some publications parallels have been drawn to the sequelae of thorotrast that was formerly used for arterial angiography. In this article the history of thorotrast use is briefly described and in particular why, despite warnings, this substance was used frequently and worldwide. A brief summary of the results of the German Thorotrast Study revealed that high excess rates were only observed for primary malignant liver tumors after a 15-year or longer latency period and to a lesser degree of leukemias, as well as for severe local complications due to paravascular injections, particularly in the neck region. Based on this historical review, we will venture to take stock of the outcome from the ''success story'' of this contrast agent. (orig.) [German] Der Nachweis von Gadoliniumablagerungen im Koerper von Patienten nach mehrfacher Injektion von Gadoliniumchelaten hat Irritationen ausgeloest. Gleichwohl gibt es bislang keine Hinweise auf resultierende klinische Spaetfolgen. In verschiedenen Veroeffentlichungen wird auf moegliche Parallelen zu den Folgen der Anwendung des frueheren Roentgenkontrastmittels Thorotrast hingewiesen. In diesem Beitrag wird die Geschichte der Thorotrastanwendung dargelegt, insbesondere weshalb es trotz der Warnungen zur haeufigen, weltweiten Anwendung des Praeparats kam. Aus einer kurzen Zusammenfassung der Ergebnisse der Deutschen Thorotraststudie wird deutlich, dass erst nach einer ueber 15-jaehrigen Latenzzeit hohe Exzessraten an primaeren Lebertumoren und in geringerem Masse auch an Leukaemien auftraten und schwerwiegende Folgen paravasaler Injektionen v. a. im Halsbereich beobachtet wurden. In einem historischen

  19. [Recent demographic trends].

    Science.gov (United States)

    1983-01-01

    A review of demographic trends in Luxembourg in 1982 is presented. A decline in fertility, the first since 1977, is noted, together with an increase in divorce, as well as a negative migration balance for the first time since 1967. Topics covered include natural increase and migration, fertility, marriage and divorce, mortality, adoption, and legislation affecting the family. Special consideration is given to the mortality experience of those who were subjected to compulsory labor during World War II.

  20. Demographic inferences from large-scale NGS data

    DEFF Research Database (Denmark)

    Pedersen, Casper-Emil Tingskov

    .g. human genetics. In this thesis, the three papers presented demonstrate the advantages of NGS data in the framework of population genetics for elucidating demographic inferences, important for understanding conservation efforts, selection and mutational burdens. In the first whole-genome study...... that the demographic history of the Inuit is the most extreme in terms of population size, of any human population. We identify a slight increase in the number of deleterious alleles because of this demographic history and support our results using simulations. We use this to show that the reduction in population size...

  1. Socio-Demographic Determinants of Eclampsia in Calabar; A Ten ...

    African Journals Online (AJOL)

    A ten-year review of the socio-demographic determinants of eclampsia was ... had past histories of eclampsia, while in 7 (18.4%) cases history of change of ... no formal education and 34.25% were subsistence farmers living in the suburbs of ...

  2. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  3. EJSCREEN Version 1, Demographic Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map service displays demographic data used in EJSCREEN. All demographic data were derived from American Community Survey 2006-2010 estimates. EJSCREEN is an...

  4. The demographic dynamics of small island societies.

    Science.gov (United States)

    Cruz, M; D'ayala, P G; Marcus, E; Mcelroy, J L; Rossi, O

    1987-01-01

    Small islands and microstates have demonstrated a unique demographic pattern, including cycles of swift population increases or decreases well beyond natural birth and death rate balances. These demographic fluctuations have been produced largely by rises or declines in market opportunities. The process of taking advantage of favorable opportunities is always followed by a specialization in the given activity, without regard to environmental protection issues or a longterm strategy for economic development and resource diversification. The population growth phase is associated with increasing fragility of the economic base, whether because of the external dangers of overspecialization or induced internal dysfunctions such as disease and resource depletion. Eventually complete collapse results, causing chronic outmigration or even depopulation. Case histories of maritime basins in the Mediterranean, Caribbean, and Pacific show that the demographic structure of small islands has been particularly sensitive to changing economic opportunities, the vagaries of market forces, and cataclysmic natural events. Experience in these areas suggests that balanced economic development of small islands should be based on diversification of activities, thus ensuring a relatively stable pattern of growth, sound environmental management, and control of dangerous demographic fluctuations. Special attention should be given to the development of broad-based research and cooperation to integrate specific island opportunities within a regional network.

  5. Demographic Structural Theory: 25 Years On

    Directory of Open Access Journals (Sweden)

    Jack A. Goldstone

    2017-12-01

    Full Text Available I am grateful to Cliodynamics for this special issue revisiting the ideas put forth in Revolution and Rebellion in the Early Modern World (Goldstone 1991, 2016 a quarter century ago. The two things that one could hope for in advancing any theory are that it proves capable of being advanced and enriched by other scholars, and that it proves capable of being applied in new ways and to new phenomena that were not anticipated. This issue gives examples of both, and shows how scholars are even now only beginning to tap the possibilities of Demographic Structural Theory (DST in explaining politics, history, and long-term economic trends. In this essay, I will tell the story of how demographic structural theory was conceived, relate its early reception among scholars, and comment on the important contributions by other scholars to this special issue.

  6. Demographics and remote locations

    Energy Technology Data Exchange (ETDEWEB)

    Coppus, G. [Dynawise Inc., Calgary, AB (Canada)

    2005-07-01

    Within the next decade, the number of people leaving the workforce will exceed the number of new entrants. The demand for workers is expected to increase in Alberta due to oil sands industry growth. Sixty-four per cent of all responding federal, provincial, and municipal government organizations have reported shortages in their work environments, and almost 8 in 10 organizations predict they will continue to be understaffed in the next 3 to 5 years. Tightness in the general labour market will have an impact on employers in remote locations, and planning is essential to avoid the creation of a mercenary culture and a reliance on compensation. Challenges found in remote locations include high turnover rates among recent hires; critical gaps in service length; aggressive retirement; and the fact that the local population is often seen as unqualified for many industrial jobs. This Power Point presentation suggested that although decisions to join or quit a company are often based on considerations such as the organizational environment and amount of compensation, the relationship between employees and management is the most important attribute in many career decisions. Rigorous quantitative analysis of current demographics combined with forecasting analysis may help to forestall recruitment difficulties for many companies. Productivity analyses, and the effects of work overload on absenteeism, attrition and quality of workmanship must also be examined. Many companies are now focusing on retention and development strategies on mid-career staff to address depletion, as well as redesigning procedures to operate with less skilled staff. It was concluded that extra efforts are now being made to attract non-traditional employees, and non-traditional employment models are being considered by some companies. refs., tabs., figs.

  7. Demographic structure and macroeconomic trends

    OpenAIRE

    Aksoy, Yunus; Basso, H.S.; Smith, Ronald; Grasl, Tobias

    2018-01-01

    We estimate the effect of changes in demographic structure on long term\\ud trends of key macroeconomic variables using a Panel VAR for 21 OECD economies from 1970-2014. The panel data variation assists the identification of demographic effects, while the dynamic structure,\\ud incorporating multiple channels of influence, uncovers long-term effects.\\ud We propose a theoretical model, relating demographics, innovation and\\ud growth, whose simulations match our empirical findings. The current\\ud...

  8. Demographic Consequences of Defeating Aging

    OpenAIRE

    Gavrilov, Leonid A.; Gavrilova, Natalia S.

    2010-01-01

    A common objection against starting a large-scale biomedical war on aging is the fear of catastrophic population consequences (overpopulation). This fear is only exacerbated by the fact that no detailed demographic projections for radical life extension scenario have been conducted so far. This study explores different demographic scenarios and population projections, in order to clarify what could be the demographic consequences of a successful biomedical war on aging. A general conclusion o...

  9. Contesting 'Patriotic History': Zimbabwe's liberation war history and ...

    African Journals Online (AJOL)

    Remarkably, the article observes that the exclusively women authored anthology on liberation war history offers an inventory of a gender based trajectory of memory, thus ... On the other hand, the sidelined demographic categories contest narrow 'patriotic history' by engineering counter discursive historical accounts.

  10. A Community Patient Demographic System

    OpenAIRE

    Gabler, James M.; Simborg, Donald W.

    1985-01-01

    A Community Patient Demographic System is described. Its purpose is to link patient identification, demographic and insurance information among multiple organizations in a community or among multiple registration systems within the same organization. This function requires that there be a competent patient identification methodology and clear definition of local responsibilities for number assignment and database editing.

  11. Demographic Trends: Impact on Schools

    Science.gov (United States)

    Chong, Sylvia N. Y.; Cheah, Horn Mun

    2010-01-01

    Background: Singapore is experiencing great demographic change. These demographic trends show fewer young people and declining birth rates, greater longevity for ageing generations and an increase in the number of non-Singaporean residents. Statistics also show that more than half of the total population increase in the last decades was…

  12. Uncovering the hidden demographic history of the USSR.

    Science.gov (United States)

    Blum, A

    1991-01-01

    After the results of the 1937 census were calculated and the figures were lower than expected, Stalin arrested the census takers, altered the figures, and cancelled it. But, he did not destroy the records; they have remained in the archives of the Central National Archives for 50 years. They are now finally open to inspection thanks to glasnost. The records that are being examined are confirming what some in the West had suspected all along. Stalin wanted the 1937 census to show 170 million people, but because of famine, the actual number was more like 162 million. Stalin wanted the census to show the world that socialism was better than capitalism in terms of growth. However the forced collectivization of farms and the forced relocations of people resulted in a famine in 1933 which wiped out about 2.5 times more people over and above normal death rates. In some regions this figure is 4.5 times what is normally was. The number of people lost during WWII is also being revised in light of these new records. It appears that 26 million people died as the result of hostilities between 1941-45. This is in addition to the number normally expected to die during the same time.

  13. Demographic history of european populations of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Olivier François

    2008-05-01

    Full Text Available The model plant species Arabidopsis thaliana is successful at colonizing land that has recently undergone human-mediated disturbance. To investigate the prehistoric spread of A. thaliana, we applied approximate Bayesian computation and explicit spatial modeling to 76 European accessions sequenced at 876 nuclear loci. We find evidence that a major migration wave occurred from east to west, affecting most of the sampled individuals. The longitudinal gradient appears to result from the plant having spread in Europe from the east approximately 10,000 years ago, with a rate of westward spread of approximately 0.9 km/year. This wave-of-advance model is consistent with a natural colonization from an eastern glacial refugium that overwhelmed ancient western lineages. However, the speed and time frame of the model also suggest that the migration of A. thaliana into Europe may have accompanied the spread of agriculture during the Neolithic transition.

  14. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    FATAH ZAREI

    loop region of individuals representing four Kurdish groups from Iran .... research studies were performed on the origin and genetic landscape of the Kurds, ... haplogroups were determined on the basis of diagnostic sites using the PhyloTree 16 ...

  15. Genetic population structuring and demographic history of red ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... 2College of Aquaculture, Ocean University of China, Qingdao 266003, China. ... changes in species' geographical distribution and abundance, which could be ...... circulation and climate change from the Santa Barbara basin.

  16. Adaptive Evolution and Demographic History of Norway Spruce (Picea Abies)

    OpenAIRE

    Källman, Thomas

    2009-01-01

    One of the major challenges in evolutionary biology is to determine the genetic basis of adaptive variation. In Norway spruce (Picea abies) the timing of bud set shows a very strong latitudinal cline despite a very low genetic differentiation between populations. The timing of bud set in Norway spruce is under strong genetic control and triggered by changes in photoperiod, but no genes controlling this response have so far been described. In this thesis we used a combination of functional stu...

  17. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    Further, the high frequencies of typical haplogroups for early farmers (H; 37.1%) and hunter-gatherers ... graphic region, the mountainous northern perimeter of the historic Fertile ..... and one sub-Saharan African (L3*) were identified in the. Kurdish ...... goats (Capra hircus) in the Zagros Mountains 10,000 years ago. Science ...

  18. Global population structure and demographic history of the grey seal

    DEFF Research Database (Denmark)

    Klimova, A.; Phillips, C. D.; Fietz, Katharina

    2014-01-01

    Although the grey seal Halichoerus grypus is one of the most familiar and intensively studied of all pinniped species, its global population structure remains to be elucidated. Little is also known about how the species as a whole may have historically responded to climate-driven changes in habitat...... a little over 10 000 years ago, consistent with the last proposed isolation of the Baltic Sea. Approximate Bayesian computation also identified genetic signals consistent with postglacial population expansion across much of the species range, suggesting that grey seals are highly responsive to changes...

  19. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    FATAH ZAREI

    mutations), and analyses of molecular variance (AMOVA) based on different criteria .... high and low levels of mean number of pairwise differences. Population ..... east frontiers of the country against the constant inroads of the Turkmen and ...

  20. Phylogeography, genetic diversity and demographic history of the ...

    Indian Academy of Sciences (India)

    Our data indicated that most of the Kurds mtDNA lineages belong to branches of the haplogroups with the Western Eurasian origin; with small fractions of the Eastern Eurasian and sub-Saharan African lineages. The low level of mtDNA diversity observed in the Havrami group presented a bias towards isolation or increased ...

  1. Habitat and scale shape the demographic fate of the keystone sea urchin Paracentrotus lividus in Mediterranean macrophyte communities.

    Directory of Open Access Journals (Sweden)

    Patricia Prado

    Full Text Available Demographic processes exert different degrees of control as individuals grow, and in species that span several habitats and spatial scales, this can influence our ability to predict their population at a particular life-history stage given the previous life stage. In particular, when keystone species are involved, this relative coupling between demographic stages can have significant implications for the functioning of ecosystems. We examined benthic and pelagic abundances of the sea urchin Paracentrotus lividus in order to: 1 understand the main life-history bottlenecks by observing the degree of coupling between demographic stages; and 2 explore the processes driving these linkages. P. lividus is the dominant invertebrate herbivore in the Mediterranean Sea, and has been repeatedly observed to overgraze shallow beds of the seagrass Posidonia oceanica and rocky macroalgal communities. We used a hierarchical sampling design at different spatial scales (100 s, 10 s and <1 km and habitats (seagrass and rocky macroalgae to describe the spatial patterns in the abundance of different demographic stages (larvae, settlers, recruits and adults. Our results indicate that large-scale factors (potentially currents, nutrients, temperature, etc. determine larval availability and settlement in the pelagic stages of urchin life history. In rocky macroalgal habitats, benthic processes (like predation acting at large or medium scales drive adult abundances. In contrast, adult numbers in seagrass meadows are most likely influenced by factors like local migration (from adjoining rocky habitats functioning at much smaller scales. The complexity of spatial and habitat-dependent processes shaping urchin populations demands a multiplicity of approaches when addressing habitat conservation actions, yet such actions are currently mostly aimed at managing predation processes and fish numbers. We argue that a more holistic ecosystem management also needs to incorporate the

  2. Predicting primate responses to "Stochastic" demographic events.

    Science.gov (United States)

    Strier, K B

    1999-01-01

    Comparative approaches in contemporary primate behavioral ecology have tended to emphasize the deterministic properties of stochastic ecological variables. Yet, primate responses to ecological fluctuations may be mediated by the interactions among demographic processes at the levels of individuals, groups, and populations. In this paper I examine long-term data collected from June 1982-July 1998 on one expanding group of muriquis (Brachyteles arachnoides) at the Estação Biologica de Caratinga, Minas Gerais, Brazil to explore the demographic and life history correlates of reproductive seasonality and skewed infant sex ratios. Variation in the size of annual birth cohorts (≥2 infants) was positively related to variation in the annual distribution of births (r (s)=0.96,n=10,p<0.01), indicating the importance of considering the effects that the number of reproductive females may have on interpretations of reproductive seasonality. The female-biased infants sex ratio documented from 59 births was attributed exclusively to multiparous mothers. Primiparous mothers produced comparable numbers of sons (n=6) and daughters (n=7), and were increasingly likely to produce daughters with each subsequent reproductive event. Seven of the 11 females that have produced≥3 infants to date exhibited biases in favor of daughters whereas only 1 was biased in favor of sons. Variation in female sensitivity to local resource competition at different stages of their life histories may account for the female-biased infant sex ration in this population.

  3. [The demographic potential of Russia].

    Science.gov (United States)

    Vishnevskii, A

    1998-05-01

    This is a general review of current demographic trends in Russia. The author analyzes the decline in population size that is taking place at the end of the twentieth century, and traces its origins as far back as the disturbances associated with World War I, the Communist revolution, and the civil war that followed it. Political repression during the Stalinist period and the tribulations experienced during World War II also contributed to the current demographic crisis. The author discusses the changes in migration patterns and the declining fertility and increasing mortality rates. The decline in life expectancy is also addressed. Some comparisons are made with the demographic situation in other European countries.

  4. Accounting for rate variation among lineages in comparative demographic analyses

    Science.gov (United States)

    Hope, Andrew G.; Ho, Simon Y. W.; Malaney, Jason L.; Cook, Joseph A.; Talbot, Sandra L.

    2014-01-01

    Genetic analyses of contemporary populations can be used to estimate the demographic histories of species within an ecological community. Comparison of these demographic histories can shed light on community responses to past climatic events. However, species experience different rates of molecular evolution, and this presents a major obstacle to comparative demographic analyses. We address this problem by using a Bayesian relaxed-clock method to estimate the relative evolutionary rates of 22 small mammal taxa distributed across northwestern North America. We found that estimates of the relative molecular substitution rate for each taxon were consistent across the range of sampling schemes that we compared. Using three different reference rates, we rescaled the relative rates so that they could be used to estimate absolute evolutionary timescales. Accounting for rate variation among taxa led to temporal shifts in our skyline-plot estimates of demographic history, highlighting both uniform and idiosyncratic evolutionary responses to directional climate trends for distinct ecological subsets of the small mammal community. Our approach can be used in evolutionary analyses of populations from multiple species, including comparative demographic studies.

  5. Linking habitat structure to life history strategy: Insights from a Mediterranean killifish

    Science.gov (United States)

    Cavraro, Francesco; Daouti, Irini; Leonardos, Ioannis; Torricelli, Patrizia; Malavasi, Stefano

    2014-01-01

    Modern theories of life history evolution deal with finding links between environmental factors, demographic structure of animal populations and the optimal life history strategy. Small-sized teleost fish, occurring in fragmented populations under contrasting environments, have been widely used as study models to investigate these issues. In the present study, the Mediterranean killifish Aphanius fasciatus was used to investigate the relationships between some habitat features and life history strategy. We selected four sites in the Venice lagoon inhabited by this species, exhibiting different combinations of two factors: overall adult mortality, related to intertidal water coverage and a consequent higher level of predator exposure, and the level of sediment organic matter, as indicator of habitat trophic richness. Results showed that these were the two most important factors influencing demography and life history traits in the four sites. Fish from salt marshes with high predator pressure were smaller and produced a higher number of eggs, whereas bigger fish and a lower reproductive investment were found in the two closed, not tidally influenced habitats. Habitat richness was positively related with population density, but negatively related with growth rate. In particular the synergy between high resources and low predation level was found to be important in shaping peculiar life history traits. Results were discussed in the light of the interactions between selective demographic forces acting differentially on age/size classes, such as predation, and habitat trophic richness that may represent an important energetic constraint on life history traits. The importance to link habitat productivity and morphology to demographic factors for a better understanding of the evolution of life history strategy under contrasting environments was finally suggested.

  6. Modeling evolutionary games in populations with demographic structure

    DEFF Research Database (Denmark)

    Li, Xiang-Yi; Giaimo, Stefano; Baudisch, Annette

    2015-01-01

    interactions, but usually omits life history and the demographic structure of the population. Here we show how an integration of both aspects can substantially alter the underlying evolutionary dynamics. We study the replicator dynamics of strategy interactions in life stage structured populations. Individuals...

  7. EJSCREEN Demographic Indicators 2015 Public

    Data.gov (United States)

    U.S. Environmental Protection Agency — EJSCREEN uses demographic factors as very general indicators of a community's potential susceptibility to the types of environmental factors included in this...

  8. EJSCREEN Demographic Indicators 2016 Public

    Data.gov (United States)

    U.S. Environmental Protection Agency — EJSCREEN uses demographic factors as very general indicators of a community's potential susceptibility to the types of environmental factors included in this...

  9. Adverse reactions to intravascularly administered contrast media

    International Nuclear Information System (INIS)

    Olin, T.

    1986-01-01

    A hypothesis is formulated about the mechanisms causing adverse reactions to contrast media. Contrast media act in two ways. They stimulate the mast cells to release histamine and leukotrienes, and they inhibit the enzymes which otherwise degrade leukotrienes. Thus individuals, especially those with a history of allergy, are easily exposed to undue amounts of leukotrienes and these are responsible for the adverse reactions. (orig.)

  10. The Demographic and Clinical Characteristics of Ulcerative Colitis in a Northeast Brazilian Population

    Directory of Open Access Journals (Sweden)

    Bruno César da Silva

    2015-01-01

    Full Text Available Introduction. The purpose of this study was to describe the clinical and demographic characteristics of UC in Bahia, a Brazilian state, and to identify the variables associated with extensive colitis, steroid therapy, immunosuppression, and colectomy. Methods. In this cross-sectional study UC patients were interviewed, and additional information was collected from the medical records. Descriptive statistics and multivariate Poisson regression analysis were used. Results. This study included 267 individuals, the mean age of whom was 39.4 years at diagnosis. There was a predominance of females and left-side colitis. Extensive colitis was positively associated with male gender, diarrhea, weight loss, and a younger age at diagnosis. In contrast, active smoking and a family history of IBD were negatively associated with extensive colitis. Positive associations were observed between steroid therapy and diarrhea, weight loss, urban patients, extraintestinal manifestations (EIMs, and hospitalization. Younger age and weight loss at diagnosis, a family history of IBD, extensive colitis, EIMs, hospitalization, and steroid therapy were all positively associated with immunosuppression. In contrast, Caucasian individuals, smokers, patients with rectal bleeding, and rural patients areas were all observed to have a decreased likelihood of immunosuppression. Conclusions. Our results corroborate the association between higher prevalence of extensive colitis and younger age at diagnosis. An association between steroid therapy and clinical presentation at diagnosis was observed. The observation that white individuals and rural patients use less immunosuppressive drugs highlights the need to study the influence of environmental and genetic factors on the behavior of UC in this population.

  11. The second demographic transition: a concise overview of its development.

    Science.gov (United States)

    Lesthaeghe, Ron

    2014-12-23

    This article gives a concise overview of the theoretical development of the concept of the "second demographic transition" since it was coined in 1986, its components, and its applicability, first to European populations and subsequently also to non-European societies as well. Both the demographic and the societal contrasts between the first demographic transition (FDT) and the second demographic transition (SDT) are highlighted. Then, the major criticisms of the SDT theory are outlined, and these issues are discussed in the light of the most recent developments in Europe, the United States, the Far East, and Latin America. It turns out that three major SDT patterns have developed and that these evolutions are contingent on much older systems of kinship and family organization.

  12. Spatial extent in demographic research - approach and problems

    Directory of Open Access Journals (Sweden)

    Knežević Aleksandar

    2015-01-01

    Full Text Available One of the starting methodological problems in demographic research is the definition of spatial extent, which mostly doesn’t correspond to spatial extent already defined by different levels of administrative-territorial unitsthat are used for distribution of usable statistical data. That’s why determining the spatial extent of a demographic research is closely tied with administrative-territorial division of the territory that is being researched, wherein the fact that differentiation of demographic phenomena and processes cannot be the only basis of setting the principles of regionalization must be strictly acknowledged. This problem is particularly common in historical demographic analyses of geographically determined wholes, which are in administratively-territorial sense represented by one or more smaller territorial units, with their borders changing through the history, which directly affects comparability of the statistical data, and makes it considerably more difficult to track demographic change through longer time intervals. The result of these efforts is usually a solution based on a compromise which enables us to examine the dynamics of population change with little deviation from already defined borders of regional geographic wholes. For that reason in this paper the problem of defining spatial extent in demographic research is examined trough several different approaches in case of Eastern Serbia, as a geographically determined region, a historic area, a spatially functioning whole and as a statistical unit for demographic research, with no judgment calls in regard to any of the regionalization principles. [Projekat Ministarstva nauke Republike Srbije, br. III 47006

  13. Development of contrast media

    International Nuclear Information System (INIS)

    Krause, W.

    1993-01-01

    Description of all contrast media (ionic and nonionic monomers, ionic and nonionic dimers) was presented. Chemotoxicity, osmolality and viscosity of some contrast agents were analyzed. The main adverse reactions to ionic and nonionic contrast media were described

  14. Radiographic contrast media

    International Nuclear Information System (INIS)

    Golman, K.; Holtz, E.; Almen, T.

    1987-01-01

    Contrast media are used in diagnostic radiology to enhance the X-ray attenuation between a body structure of interest and the surrounding tissue. A detail becomes perceptible on a roentgenogram only when its contrast exceeds a minimum value in relation to the background. Small areas of interest must have higher contrast than the background. The contrast effect depends on concentration of the contrast media with the body. A high contrast media concentration difference thus gives rise to more morphological details in the radiographs. Contrast media can be divided into negative contrast media such as air and gas which attenuate X-rays less than the body tissues, and positive contrast materials which attenuate X-rays more than the body tissues. The positive contrast media all contain either iodine (atomic number 53) or barium (atomic number 56) and can be divided into water-insoluble and water-soluble contrast media

  15. Demographics in Astronomy and Astrophysics

    Science.gov (United States)

    Ulvestad, James S.

    2011-05-01

    Astronomy has been undergoing a significant demographic shift over the last several decades, as shown by data presented in the 2000 National Research Council (NRC) report "Federal Funding of Astronomical Research," and the 2010 NRC report, "New Worlds, New Horizons in Astronomy and Astrophysics." For example, the number of advertised postdoctoral positions in astronomy has increased much more rapldly than the number of faculty positions, contributing to a holding pattern of early-career astronomers in multiple postdoctoral positions. This talk will summarize some of the current demographic trends in astronomy, including information about gender and ethnic diversity, and describe some of the possible implications for the future. I thank the members of the Astro2010 Demographics Study Group, as well as numerous white-paper contributors to Astro2010, for providing data and analyses.

  16. Social demographic change and autism.

    Science.gov (United States)

    Liu, Kayuet; Zerubavel, Noam; Bearman, Peter

    2010-05-01

    Parental age at child's birth--which has increased for U.S. children in the 1992-2000 birth cohorts--is strongly associated with an increased risk of autism. By turning a social demographic lens on the historical patterning of concordance among twin pairs, we identify a central mechanism for this association: de novo mutations, which are deletions, insertions, and duplications of DNA in the germ cells that are not present in the parents' DNA. Along the way, we show that a demographic eye on the rising prevalence of autism leads to three major discoveries. First, the estimated heritability of autism has been dramatically overstated. Second, heritability estimates can change over remarkably short periods of time because of increases in germ cell mutations. Third, social demographic change can yield genetic changes that, at the population level, combine to contribute to the increased prevalence of autism.

  17. Subacute Sclerosing Panencephalitis: Clinical and Demographic Characteristics

    International Nuclear Information System (INIS)

    Rafique, A.; Amjad, N.; Chand, P.; Ahmed, K.; Ibrahim, S.; Zaidi, S. S. Z.; Rana, M. S.

    2014-01-01

    Objective: To determine the clinical and demographic characteristics of children diagnosed with Subacute sclerosing panencephalitis (SSPE). Study Design: Case series. Place and Duration of Study: The Aga Khan University Hospital, Karachi, from January 2000 to June 2012. Methodology: A retrospective analysis was done, regarding medical charts of 43 children under the age of 16 years with a discharge diagnosis of SSPE. Demographic and clinical characteristics were recorded. Results were expressed as percentages. Results: Most of the 43 patients were male (72%). The average age at presentation was 8.7 years with average duration of symptoms being 100.6 days. History of measles was present in 17 patients (39.5%). All children had seizures at presentation and 65% had cognitive impairment. Most patients required poly therapy for control of seizures. Sodium valproate was the most commonly used anti-epileptic agent; Isoprinosine was tried in 22 (51%) patients. CSF for antimeasles antibodies was positive in approximately 86% of the 40 (93%) children. EEG showed burst suppression pattern in 36 (83.7%) cases. Forty-two patients (97.6%) were discharged home in a vegetative state. Conclusion: SSPE is progressive neurodegenerative disorder. It can be prevented by timely immunization against measles. Measles antibody in the CSF is diagnostic for SSPE and is helpful in early diagnosis. Most patients experience a gradual but progressive decline in motor and cognitive functions. (author)

  18. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Joyce T. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Robinson, Joshua D. [Ann and Robert Lurie Children' s Hospital of Chicago, Division of Pediatric Cardiology, 225 E. Chicago Ave., Box 21, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Deng, Jie [Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Rigsby, Cynthia K. [Ann and Robert Lurie Children' s Hospital of Chicago, Department of Pediatrics, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Ann and Robert Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)

    2016-12-15

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  19. Combined blood pool and extracellular contrast agents for pediatric and young adult cardiovascular magnetic resonance imaging

    International Nuclear Information System (INIS)

    Johnson, Joyce T.; Robinson, Joshua D.; Deng, Jie; Rigsby, Cynthia K.

    2016-01-01

    A comprehensive cardiac magnetic resonance (cardiac MR) study including both late gadolinium enhancement (LGE) and MR angiography may be indicated for patients with a history of acquired or congenital heart disease. To study the novel use of an extracellular agent for assessment of LGE combined with a blood pool contrast agent for detailed MR angiography evaluation to yield a comprehensive cardiac MR study in these patients. We reviewed clinical cardiac MR studies utilizing extracellular and blood pool contrast agents and noted demographics, clinical data and adverse events. We rated LGE image quality and MR angiography image quality for each vascular segment and calculated inter-rater variability. We also quantified contrast-to-noise ratio (CNR). Thirty-three patients (mean age 13.9 ± 3 years) received an extracellular contrast agent (10 gadobenate dimeglumine, 23 gadopentetate dimeglumine) and blood pool contrast agent (33 gadofosveset trisodium). No adverse events were reported. MRI indications included Kawasaki disease (8), cardiomyopathy and coronary anatomy (15), repaired congenital heart disease (8), and other (2). Mean LGE quality was 2.6 ± 0.6 with 97% diagnostic imaging. LGE quality did not vary by type of contrast agent given (P = 0.07). Mean MR angiography quality score was 4.7 ± 0.6, with high inter-rater agreement (k = 0.6-0.8, P < 0.002). MR angiography quality did not vary by type of contrast agent used (P = 0.6). Cardiac MR studies utilizing both extracellular and blood pool contrast agents are feasible and safe and provide excellent-quality LGE and MR angiography images. The use of two contrast agents allows for a comprehensive assessment of both myocardial viability and vascular anatomy during the same exam. (orig.)

  20. Logistics Dynamics and Demographic Change

    NARCIS (Netherlands)

    Klumpp, Matthias; Abidi, Hella; Bioly, Sascha; Buchkremer, Rüdiger; Ebener, Stefan; Sandhaus, Gregor; Freitag, Michael; Kotzab, Herbert; Pannek, Jürgen

    2016-01-01

    Change and dynamics in logistics are interestingly driven at the same time by external as well as internal forces. This contribution outlines a big data literature review methodology to overview recognizable external changes and analyzes the interaction of one major trend—demographic change—further

  1. Are Demographics the Nation's Destiny?

    Science.gov (United States)

    Glass, Gene V.

    2008-01-01

    In this article, the author discusses the demographic trends affecting America's public schools. As an expert on empirical evaluation of education, the author believes the major debates over vouchers, charter schools, bilingual education, and other issues are not really about preparing the next generation to compete with China or India, or about…

  2. Demographic Modelling in Weed Biocontrol

    Science.gov (United States)

    Demographic matrix modeling of plant populations can be a powerful tool to identify key life stage transitions that contribute the most to population growth of an invasive plant and hence should be targeted for disruption. Therefore, this approach has the potential to guide the pre-release selection...

  3. A Statistical Assessment of Demographic Bonus towards Poverty Alleviation

    Directory of Open Access Journals (Sweden)

    Jamal Abdul Nasir

    2011-09-01

    Full Text Available The shift of birth and death rates from high to low level in any population is referred as demographic transition. Mechanically, the transition of a society creates more working member of its own population commonly called demographic bonus. This articleempirically explores the realistic soundness of demographic bonus in reducing the poverty level of the society. Three contrasting regions namely Eastern Asia, Central America and Oceania were selected for analytical purposes. The findings indicate that Eastern Asia and Oceania are currently facing the end of their transition whereas theCentral America is lagged behind in transition. Central America due to last runner in transition race is the sustained recipient of its own demographic bonus by the year 2030.On the basis of three mechanisms namely: labour supply, savings and human capital, the Eastern Asian region is found to be successful beneficiary of its own demographic gift which concludes that many million people have escaped from poverty. Under the right policy environment on the above three mechanisms, Eastern Asia experience indicates the realistic contribution of demographic bonus to reduce poverty.

  4. [Recent demographic trends in Turkey].

    Science.gov (United States)

    Behar, C

    1993-01-01

    Coverage of Turkey's vital registration system remains incomplete, and it cannot yet be used to measure annual population changes. Data and demographic indices based on the 1990 census and the 1989 National Demographic Survey are the most recent available. Turkey's population in 1990 was 56 million. The proportion urban increased to 59% from 49.2% in 1980. Nearly 35% of the population was under 15 years old, and the median age was 21.6 for males and 22.3 for females. The average age at first marriage in 1989 was 24.8 for men and 21.8 for women. Mortality has been in continuous decline. The crude death rate dropped from 16.4/1000 in 1960-65 to slightly under 8 in 1989. Life expectancy at birth was 63.3 for men and 66 for women. The infant mortality rate declined from 166 in 1965-70 to 85 in 1989. Rural or urban residence and maternal educational level were the most significant determinants of infant mortality differentials. Turkey's total fertility rate declined from 6.2 in 1960 to 4.3 in 1978 and 3.4 in 1988-89. The crude birth rate declined from around 40/1000 in 1968 to under 28/1000 in 1989. Fertility began to decline in the last third of the nineteenth century in Istanbul and other large cities of the Ottoman Empire. Istanbul's total fertility rate was a relatively low 3.9 even before World War I. Turkey adopted a policy to slow demographic growth in the mid 1960s, and family planning activities were supported by nongovernmental organizations. The direct impact of these policies on demographic behavior appears to have been somewhat limited, and the use of traditional methods of birth limitation remains widespread. Abortion was legalized in 1983 and is available at public hospitals. The proportion of married women aged 15-49 who use contraception increased from 38% in 1973 to 63% in 1988. Regional differentials in demographic indices are significant in Turkey, with the Anatolian East and Southeast lagging behind other regions in fertility and mortality decline

  5. Demographic features of subjects with congenital glaucoma

    Science.gov (United States)

    Tamçelik, Nevbahar; Atalay, Eray; Bolukbasi, Selim; Çapar, Olgu; Ozkok, Ahmet

    2014-01-01

    Context: Congenital glaucoma is a potentially blinding ocular disease of the childhood. Identification of the possible associated risk factors and may be helpful for prevention or early detection of this public health problem. Aims: To demonstrate the demographic features of congenital glaucoma subjects. Setting and Design: The charts of congenital glaucoma patients referred to Tamcelik Glaucoma Center were retrospectively reviewed through the dates of 2000 and 2013. Materials and Methods: Analyzed data included diagnosis, age at first presentation, symptoms at first presentation, laterality of the disease, sex, presence of consanguinity, family history of congenital glaucoma, maturity of the fetus at delivery, and maternal age at conception. Statistical Analysis Used: Statistical Package for Social Sciences (SPSS) version 19.0 by IBM (SPSS Inc, Chicago, Illinois, USA) was used to compare the mean of continuous variables with Student's t-test and analysis of variance (ANOVA) and χ2 test was used to test differences in proportions of categorical variables. Results: The data of 600 eyes of 311 patients were analyzed. The distribution of primary and secondary congenital glaucoma among the patients were 63.3% (n = 197) and 36.7% (n = 114), respectively. Of the 311 patients, 57.2% (n = 178) were male and 42.8% (n = 133) were female. The overall frequency of bilateral disease was 92.3% (n = 287). Overall rate of consanguinity and positive family history was 45.3% (n = 141) and 21.2% (n = 66), respectively. Conclusions: Bilateral disease in this study was more common than previously reported studies. Positive family history was more frequent in primary congenital glaucoma although not statistically significant. PMID:24881602

  6. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me...

  7. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast...

  8. Perforations during contrast enema

    International Nuclear Information System (INIS)

    Vogel, H.; Steinkamp, U.; Grabbe, E.; Allgemeines Krankenhaus Ochsenzoll, Hamburg

    1983-01-01

    During contrast enema, perforation into the retroperitoneal space can be differentiated from perforation into the peritoneum and perforation into the intestinal wall associated with formation of barium granulomas or submucosal spreading of the contrast medium. Other special forms are perforation with contrast medium embolism of diverticula; of the processus vermiformis; penetration of contrast medium into fistulous systems and from the operated areas. Risk factors are: balloon catheter, intestinal tubes with a hard tip, preternatural anus, excessive enema pressure, contrast medium additions, preceding manipulations, intestinal diseases, advanced age and delegation of manipulations to assistants and unskilled staff. Children are particularly at risk. (orig.) [de

  9. Contrast induced nephropathy

    DEFF Research Database (Denmark)

    Stacul, Fulvio; van der Molen, Aart J; Reimer, Peter

    2011-01-01

    PURPOSE: The Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) has updated its 1999 guidelines on contrast medium-induced nephropathy (CIN). AREAS COVERED: Topics reviewed include the definition of CIN, the choice of contrast medium, the prophylactic me....../min/1.73 m (2) is CIN risk threshold for intravenous contrast medium. • Hydration with either saline or sodium bicarbonate reduces CIN incidence. • Patients with eGFR = 60 ml/min/1.73 m (2) receiving contrast medium can continue metformin normally....

  10. Bohmian histories and decoherent histories

    International Nuclear Information System (INIS)

    Hartle, James B.

    2004-01-01

    The predictions of the Bohmian and the decoherent (or consistent) histories formulations of the quantum mechanics of a closed system are compared for histories--sequences of alternatives at a series of times. For certain kinds of histories, Bohmian mechanics and decoherent histories may both be formulated in the same mathematical framework within which they can be compared. In that framework, Bohmian mechanics and decoherent histories represent a given history by different operators. Their predictions for the probabilities of histories of a closed system therefore generally differ. However, in an idealized model of measurement, the predictions of Bohmian mechanics and decoherent histories coincide for the probabilities of records of measurement outcomes. The formulations are thus difficult to distinguish experimentally. They may differ in their accounts of the past history of the Universe in quantum cosmology

  11. History Matters

    Institute of Scientific and Technical Information of China (English)

    2017-01-01

    In 2002, she began working as alecturer at Minzu University of China.Now, she teaches English, historicalliterature, ancient Chinese history,historical theory and method, ancientsocial history of China, ancient palacepolitical history of China and the historyof the Sui and Tang dynasties and thePeriod of Five Dynasties.

  12. Economic Effects of Demographic Ageing

    Directory of Open Access Journals (Sweden)

    Litra A.V.

    2014-12-01

    Full Text Available Romania goes through profound changes due to unprecedented demographic developments. As a result of declining birth rates and emigration after 1990, by the year 2060 is looming a possible doubling of the percentage of the population 65 years and over, from 15 to 30%, and the working age population to fall by about 30 percent. Deterioration of the relationship between labour force and inactive population leads to pressure on the public budget and tax system, strains on pension and social security systems, redefining consumer preferences, type and size of the saved or spent amounts, higher demand for healthcare services, increasing poverty risk for elderly households.

  13. Anaphylactoid reactions after iodinated contrast media

    International Nuclear Information System (INIS)

    Strejcek, J.; Sehr, A.

    1987-01-01

    A survey is presented of data published in the literature on the incidence of undesirable and especially anaphylactoid reactions to intravenously administered iodinated contrast media used in radiodiagnosis, this with regard to age, sex, allergy in the patient's history, previously administered contrast media, possible previous reaction. A detailed description is presented of the assumed mechanisms of these reactions. There does not exist any reliable premedication. It is always indispensable to consider the indications of the examination using iodinated contrast agents and the possibilities of immediate and qualified resuscitation. (author). 2 tabs., 36 refs

  14. Histories electromagnetism

    International Nuclear Information System (INIS)

    Burch, Aidan

    2004-01-01

    Working within the HPO (History Projection Operator) Consistent Histories formalism, we follow the work of Savvidou on (scalar) field theory [J. Math. Phys. 43, 3053 (2002)] and that of Savvidou and Anastopoulos on (first-class) constrained systems [Class. Quantum Gravt. 17, 2463 (2000)] to write a histories theory (both classical and quantum) of Electromagnetism. We focus particularly on the foliation-dependence of the histories phase space/Hilbert space and the action thereon of the two Poincare groups that arise in histories field theory. We quantize in the spirit of the Dirac scheme for constrained systems

  15. Phase contrast image synthesis

    DEFF Research Database (Denmark)

    Glückstad, J.

    1996-01-01

    A new method is presented for synthesizing arbitrary intensity patterns based on phase contrast imaging. The concept is grounded on an extension of the Zernike phase contrast method into the domain of full range [0; 2 pi] phase modulation. By controlling the average value of the input phase funct...... function and by choosing appropriate phase retardation at the phase contrast filter, a pure phase to intensity imaging is accomplished. The method presented is also directly applicable in dark field image synthesis....

  16. Dialysis and contrast media

    International Nuclear Information System (INIS)

    Morcos, Sameh K.; Thomsen, Henrik S.; Webb, Judith A.W.

    2002-01-01

    In a previous survey we revealed uncertainty among responders about (a) whether or not to perform hemodialysis in patients with severely reduced renal function who had received contrast medium; and (b) when to perform hemodialysis in patients on regular treatment with hemodialysis or continuous ambulatory dialysis who received contrast medium. Therefore, the Contrast Media Safety Committee of The European Society of Urogenital Radiology decided to review the literature and to issue guidelines. The committee performed a Medline search. Based on this, a report and guidelines were prepared. The report was discussed at the Ninth European Symposium on Urogenital Radiology in Genoa, Italy. Hemodialysis and peritoneal dialysis safely remove both iodinated and gadolinium-based contrast media. The effectiveness of hemodialysis depends on many factors including blood and dialysate flow rate, permeability of dialysis membrane, duration of hemodialysis and molecular size, protein binding, hydrophilicity, and electrical charge of the contrast medium. Generally, several hemodialysis sessions are needed to removal all contrast medium, whereas it takes 3 weeks for continuous ambulatory dialysis to remove the agent completely. There is no need to schedule the dialysis in relation to the injection of iodinated or MR contrast media or the injection of contrast agent in relation to the dialysis program. Hemodialysis does not protect poorly functioning kidneys against contrast-medium-induced nephrotoxicity. Simple guidelines are given. (orig.)

  17. Portraying User Interface History

    DEFF Research Database (Denmark)

    Jørgensen, Anker Helms

    2008-01-01

    history. Next the paper analyses a selected sample of papers on UI history at large. The analysis shows that the current state-of-art is featured by three aspects: Firstly internalism, in that the papers adress the tech­nologies in their own right with little con­text­ualization, secondly whiggism...... in that they largely address prevailing UI techno­logies, and thirdly history from above in that they focus on the great deeds of the visionaries. The paper then compares this state-of-art in UI history to the much more mature fields history of computing and history of technology. Based hereon, some speculations......The user interface is coming of age. Papers adressing UI history have appeared in fair amounts in the last 25 years. Most of them address particular aspects such as an in­novative interface paradigm or the contribution of a visionary or a research lab. Contrasting this, papers addres­sing UI...

  18. Relation Between Demographic Factors And Hospitalization In ...

    African Journals Online (AJOL)

    Relation Between Demographic Factors And Hospitalization In Patients With Gastrointestinal Disorders, Using Quantail Regression Analysis. ... East African Journal of Public Health ... Objective: The aim of this study is to investigate relation between demographic factors and hospitalization in gastrointestinal disorders.

  19. Understanding the Demographic and Health Transition in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    23 juin 2009 ... Understanding the Demographic and Health Transition in Developing Countries ... countries comes from analysis of demographic and health survey data. ... Navrongo (Ghana), Matlab (Bangladesh) and Filabavi (Viet Nam) ...

  20. Contrast analysis : A tutorial

    NARCIS (Netherlands)

    Haans, A.

    2018-01-01

    Contrast analysis is a relatively simple but effective statistical method for testing theoretical predictions about differences between group means against the empirical data. Despite its advantages, contrast analysis is hardly used to date, perhaps because it is not implemented in a convenient

  1. Demographic Ageing on Croatian Islands

    Directory of Open Access Journals (Sweden)

    Ivo Nejašmić

    2013-08-01

    Full Text Available This paper analyses the changes in the population structure of the Croatian islands by age, warns of the degree of ageing, provides spatial differentiation of this process and presents perspective of ageing at the level of settlement. Typing of population ageing is based on scores and has seven types. The total island population in 2011 belongs to the type 5 – very old population. Almost a half of the settlements (out of 303 have been affected by the highest levels of ageing (types 6 and 7. It was found that a quarter of island settlements will become “dead villages” in a foreseeable future; most of them are on small islands but also in the interior of larger islands. These are villages decaying in every respect, in which the way of life, as we know it, veins and goes out. The present ageing villagers are their last residents in most cases. Eve¬rything suggests that demographic recovery of the islands is not possible with the forces in situ. It is important to strike a balance between the needs and opportunities in order to successfully organize life on the islands, both small and large ones, and the fact is that there is a continuing disparity, which is especially profound in small islands. A sensitive and selective approach is needed to overcome the unfavourable demographic trends. Therefore it is necessary to respect the particularities of indi¬vidual islands and island groups in devising development strategy. Solutions to the problems must come of the local and wider community in synergy with relevant professional and scientific institutions. However, if the solutions are not found or measures do not give results, if the islands are left to desorganisation and senilisation, a part of the islands will become a wasteland. With regard to the value of this area whose wealth are people in the first place, this would be an intolerable civilization decline.

  2. Sociocultural and Demographic Risk Factors for the Development of Multiple Sclerosis in Kuwait: A Case - Control Study.

    Directory of Open Access Journals (Sweden)

    Suhail N Al-Shammri

    Full Text Available Immunological, genetic and environmental factors are believed to play important roles in the pathogenesis of Multiple Sclerosis (MS. There have been many studies on risk factors for MS but these have been mainly in Caucasian populations; robust studies in Arab populations remain relatively uncommon. This study therefore aimed to identify behavioral, socio-cultural, and demographic factors associated with development of MS in Kuwait, a high income Arab country, currently undergoing a demographic transition.In this case- control study, 195 Kuwaiti MS patients and 146 healthy age and sex-matched controls were recruited. Both groups of subjects were interviewed using a structured questionnaire, in relation to anthropometric, socio-cultural and demographic data, residence during the 1990/91 Gulf War and current and past medical history, including medications. We also clinically evaluated, and retrospectively reviewed medical records of patients to derive appropriate clinical information, including associated chronic medical illness requiring long-term treatment.On multiple logistic regression analysis after adjustment for potential confounders including age, gender and BMI, in all the subjects, a positive associations prevail with presence of MS and some sociocultural and demographic factors, which included non-Bedouin ethnicity (AOR 2, 95% CI 1.0-3.9, p 0.049, positive family history of MS (AOR 10.6, 95% CI 3.0-36.9, p < 0.001, and low daily sunlight exposure of < 15min/day (AOR 5.3, 95% CI 2.7-10.5 p < 0.001. In addition, while 41.8% of MS patients indicated at least one comorbidity, only 26.8% of the controls reported any associated physical illness, with the suggestion that presence of certain comorbidities might increase MS risk (AOR 2.4, 95% CI 1.3-4.7, p < 0.001. Other risk variables such as smoking status and mode of routine outdoor dressing were not significant in all the MS subjects taken as a whole, but demonstrated variably positive

  3. Demographic controls of future global fire risk

    Science.gov (United States)

    Knorr, W.; Arneth, A.; Jiang, L.

    2016-08-01

    Wildfires are an important component of terrestrial ecosystem ecology but also a major natural hazard to societies, and their frequency and spatial distribution must be better understood. At a given location, risk from wildfire is associated with the annual fraction of burned area, which is expected to increase in response to climate warming. Until recently, however, only a few global studies of future fire have considered the effects of other important global environmental change factors such as atmospheric CO2 levels and human activities, and how these influence fires in different regions. Here, we contrast the impact of climate change and increasing atmospheric CO2 content on burned area with that of demographic dynamics, using ensembles of climate simulations combined with historical and projected population changes under different socio-economic development pathways for 1901-2100. Historically, humans notably suppressed wildfires. For future scenarios, global burned area will continue to decline under a moderate emissions scenario, except for low population growth and fast urbanization, but start to increase again from around mid-century under high greenhouse gas emissions. Contrary to common perception, we find that human exposure to wildfires increases in the future mainly owing to projected population growth in areas with frequent wildfires, rather than by a general increase in burned area.

  4. Entangled histories

    International Nuclear Information System (INIS)

    Cotler, Jordan; Wilczek, Frank

    2016-01-01

    We introduce quantum history states and their mathematical framework, thereby reinterpreting and extending the consistent histories approach to quantum theory. Through thought experiments, we demonstrate that our formalism allows us to analyze a quantum version of history in which we reconstruct the past by observations. In particular, we can pass from measurements to inferences about ‘what happened’ in a way that is sensible and free of paradox. Our framework allows for a richer understanding of the temporal structure of quantum theory, and we construct history states that embody peculiar, non-classical correlations in time. (paper)

  5. Contrast agents for MRI

    International Nuclear Information System (INIS)

    Bonnemain, B.

    1994-01-01

    Contrast agents MRI (Magnetic Resonance Imaging) have been developed to improve the diagnostic information obtained by this technic. They mainly interact on T1 and T2 parameters and increase consequently normal to abnormal tissues contrast. The paramagnetic agents which mainly act on longitudinal relaxation rate (T1) are gadolinium complexes for which stability is the main parameter to avoid any release of free gadolinium. The superparamagnetic agents that decrease signal intensity by an effect on transversal relaxation rate (T2) are developed for liver, digestive and lymph node imaging. Many area of research are now opened for optimal use of present and future contrast agents in MRI. (author). 28 refs., 4 tabs

  6. Compressive Phase Contrast Tomography

    International Nuclear Information System (INIS)

    Maia, Filipe; MacDowell, Alastair; Marchesini, Stefano; Padmore, Howard A.; Parkinson, Dula Y.; Pien, Jack; Schirotzek, Andre; Yang, Chao

    2010-01-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. Interference effects visible with high brightness sources creates higher contrast, edge enhanced images. When the object is piecewise smooth (made of big blocks of a few components), such higher contrast datasets have a sparse solution. We apply basis pursuit solvers to improve SNR, remove ring artifacts, reduce the number of views and radiation dose from phase contrast datasets collected at the Hard X-Ray Micro Tomography Beamline at the Advanced Light Source. We report a GPU code for the most computationally intensive task, the gridding and inverse gridding algorithm (non uniform sampled Fourier transform).

  7. Intellectual History

    DEFF Research Database (Denmark)

    In the 5 Questions book series, this volume presents a range of leading scholars in Intellectual History and the History of Ideas through their answers to a brief questionnaire. Respondents include Michael Friedman, Jacques le Goff, Hans Ulrich Gumbrecht, Jonathan Israel, Phiip Pettit, John Pocock...

  8. Generalized Phase Contrast

    CERN Document Server

    Glückstad, Jesper

    2009-01-01

    Generalized Phase Contrast elevates the phase contrast technique not only to improve phase imaging but also to cross over and interface with diverse and seemingly disparate fields of contemporary optics and photonics. This book presents a comprehensive introduction to the Generalized Phase Contrast (GPC) method including an overview of the range of current and potential applications of GPC in wavefront sensing and phase imaging, structured laser illumination and image projection, optical trapping and manipulation, and optical encryption and decryption. The GPC method goes further than the restrictive assumptions of conventional Zernike phase contrast analysis and achieves an expanded range of validity beyond weak phase perturbations. The generalized analysis yields design criteria for tuning experimental parameters to achieve optimal performance in terms of accuracy, fidelity and light efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, ...

  9. Mamografia Espectral de Contraste

    OpenAIRE

    Martins, Inês Santiago; Pereira, Inês; Pacheco, Hugo Pisco; Moutinho, Leonor

    2014-01-01

    A mamografia de contraste é uma aplicação recente possível com a mamografia digital directa, que utiliza contraste iodado endovenoso tendo como princípio a neovascularização induzida no cancro da mama, permitindo obter informação morfológica e funcional. Na mamografia espectral de contraste realiza-se uma aquisição simultânea com alta e baixa energia para cada incidência após administração de contraste iodado endovenoso. É depois feita uma imagem recombinada em que são realçadas as áreas que ...

  10. Aspiration of Barium Contrast

    OpenAIRE

    Fuentes Santos, Cristina; Steen, Bárbara

    2014-01-01

    The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical fil...

  11. Criminal Justice History

    Directory of Open Access Journals (Sweden)

    Thomas Krause

    2005-01-01

    Full Text Available This review article discusses studies on the history of crime and the criminal law in England and Ireland published during the last few years. These reflect the ›history of crime and punishment‹ as a more or less established sub-discipline of social history, at least in England, whereas it only really began to flourish in the german-speaking world from the 1990s onwards. By contrast, the legal history of the criminal law and its procedure has a strong, recently revived academic tradition in Germany that does not really have a parallel in the British Isles, whose legal scholars still evidence their traditional reluctance to confront penal subjects.

  12. CONSEQUENCES OF THE DEMOGRAPHIC CRISIS

    Directory of Open Access Journals (Sweden)

    LIVIU RADU

    2014-11-01

    Full Text Available Major dysfunctionalities can arise from the demographic decline, both on a social level and from the perspective of the economic-financial evolution of the world’s states. The obvious aging of the industrialized states’ population overlapping the import of cheap workforce in the developing countries can start mutations whose consequences are somewhat predictable but discouraging. An accelerated urbanization of the states is foreseen, as well as the decrease of birthrates, negative external migration, increase of mortality and its stagnation in a larger value than that of the birthrate, and not least the population’s aging will hinder a part of the developing countries to sustain a high rhythm of long-term economical increase. The socialeconomic consequences will be reflected in the labor market, the householders’ amount of income as well as in the education’s level. All of these aspects call for a rethinking of the public politics, especially of the social insurance’s system and of the education, a reorientation of the economy based on the increase of specializing in production and productivity, as well as a financial stability unburdened by the politics’ interference in the business environment.

  13. Public health and demographic statistics

    International Nuclear Information System (INIS)

    Patrick, C.H.; Loebl, A.S.; Miller, F.L.; Ritchey, P.N. Jr.

    1976-01-01

    The purpose of this program is to assess the methodology and available data sources appropriate for use in analytical studies and environmental impact statements concerning the health effects of nuclear power plants. The techniques developed should be applicable as well to evaluation of the known risks of high levels of radiation exposure and of conflicting evidence on low-level effects, such as those associated with the normal operations of nuclear power plants. To accomplish this purpose, a two-pronged approach has been developed. The first involves a determination of the public health and demographic data sources of local, state, and federal origin that are available for use in analyses of health effects and environmental impact statements. The second part involves assessment of the methods used by epidemiologists, biostatisticians, and other scientists as found in the literature on health effects. This two-pronged approach provides a means of assessing the strength and shortcomings of studies of the impact of nuclear facilities on the health of the general population in a given locality

  14. Gender inequalities and demographic behavior.

    Science.gov (United States)

    1995-01-01

    A summary was provided of the central findings about gender inequalities in Egypt, India, Ghana, and Kenya published by the Population Council in 1994. These countries exhibited gender inequalities in different ways: the legal, economic, and educational systems; family planning and reproductive health services; and the health care system. All countries had in common a high incidence of widowhood. Widowhood was linked with high levels of insecurity, which were linked with high fertility. Children thus became insurance in old age. In Ghana, women's insecurity was threatened through high levels of marital instability and polygyny. In Egypt, insecurity was translated into economic vulnerability because of legal discrimination against women when family systems were disrupted. In India and all four countries, insecurity was reflective of limited access to education, an impediment to economic autonomy. In all four countries, women's status was inferior due to limited control over reproductive decision making about childbearing limits and contraception. In India, the cultural devaluation of girls contributed to higher fertility to satisfy the desire for sons. In India and Egypt, family planning programs were dominated by male-run organizations that were more concerned about demographic objectives than reproductive health. The universal inequality was the burden women carry for contraception. Family planning programs have ignored the local realities of reproductive behavior, family structures, and gender relations. The assumption that husbands and wives have similar fertility goals or that fathers fully share the costs of children is mistaken in countries such as Ghana. Consequently, fertility has declined less than 13% in Ghana, but fertility has declined by over 30% in Kenya. Family planning programs must be aware of gender issues.

  15. [Maternal mortality: the demographic aspects].

    Science.gov (United States)

    Sanogo, D

    1989-10-01

    The World Health Organization (WHO) has defined maternal mortality (MM) as a death following a delivery or during the 42 day period following a prolonged or complicated delivery. This definition is ambiguous because it does not take into account the institutional causes (deficiencies) that lead to MM in Sub-Saharan Africa (SSA) nor does it reflect all the reasons leading to MM because of the lack of nationwide health information systems and the lack of accurate statistics. While developed countries can depend on the state to provide accurate statistics, developing countries depend on hospitals, health training centers and special surveys to provide such data which often leads to 25-50% gross underestimations of MM. The most recent WHO data (1989) shows that SSA has the highest MM rates worldwide, ranging from 500- 700/100,000 as compared to Asia with 55-650; Latin America with 110-210 and the developed countries with 10-48. The data for SSA doesn't reflect the true situation in the rural areas where MM rates are over 1000/1000,000. MM is a symptom of poor countries where women contribute to their own deaths through repeated pregnancies, causing significant socioeconomic losses to society. UNICEF (1988) has categorized the demographic factors as high risk for women based on: 1) the age of the mother, and 2) the number of pregnancies. Family planning (FP) reduces MM by preventing illegal abortions; it reduces the number of unwanted pregnancies and increases the earnings of a community by reducing the number of pregnant women. The experience of developed countries demonstrates how women have avoided high-risk and unwanted pregnancies.

  16. Correlating intravenous radiographic contrast media reactions with the allergic profile

    International Nuclear Information System (INIS)

    Chua-Lim, A.; Enright, T.; Duda, E.; Lim, D.T.

    1987-01-01

    To determine the relevance of allergy as a predisposing factor in reactions to radiographic contrast media, the authors investigated the incidence of allergy among 100 randomly selected patients undergoing intravenous excretory urography and CT. The study population consisted of 50 reactors and 50 nonreactos to radiographic contrast media. All 100 subjects completed an allergy history, percutaneous allergy tests, and an in vitro specific IgE assay to common allergens. Thirty-four of 50 reactors had a positive allergy history, in contrast to 15 of 50 nonreactors (P < .001). Twenty-seven reactors had positive skin tests, in contrast to 12 of 50 nonreactors (P < .005). In vitro IgE assay results are pending. The results indicate that patients with positive histories or positive skin tests or both are at an increased risk for reactions to radiographic contrast media

  17. Public Pension Reform, Demographics, and Inequality

    OpenAIRE

    von Weizsäcker, Robert K

    1994-01-01

    Starting from a simple, descriptive model of individual income, an explicit link between the age composition of a population and the personal distribution of incomes is established. Demographic effects on income inequality are derived. Next, a pay-as-you-go financed state pension system is introduced. The resulting government budget constraint entails interrelations between fiscal and demographic variables, causing an additional, indirect demographic impact on the distribution. This is shown ...

  18. Molecular evidence for a recent demographic expansion in the puma (Puma concolor) (Mammalia, Felidae)

    Science.gov (United States)

    Matte, Eunice M.; Castilho, Camila S.; Miotto, Renata A.; Sana, Denis A.; Johnson, Warren E.; O’Brien, Stephen J.; de Freitas, Thales R. O.; Eizirik, Eduardo

    2013-01-01

    The puma is an iconic predator that ranges throughout the Americas, occupying diverse habitats. Previous phylogeographic analyses have revealed that it exhibits moderate levels of genetic structure across its range, with few of the classically recognized subspecies being supported as distinct demographic units. Moreover, most of the species’ molecular diversity was found to be in South America. To further investigate the phylogeographic structure and demographic history of pumas we analyzed mtDNA sequences from 186 individuals sampled throughout their range, with emphasis on South America. Our objectives were to refine the phylogeographic assessment within South America and to investigate the demographic history of pumas using a coalescent approach. Our results extend previous phylogeographic findings, reassessing the delimitation of historical population units in South America and demonstrating that this species experienced a considerable demographic expansion in the Holocene, ca. 8,000 years ago. Our analyses indicate that this expansion occurred in South America, prior to the hypothesized re-colonization of North America, which was therefore inferred to be even more recent. The estimated demographic history supports the interpretation that pumas suffered a severe demographic decline in the Late Pleistocene throughout their distribution, followed by population expansion and re-colonization of the range, initiating from South America. PMID:24385863

  19. Molecular evidence for a recent demographic expansion in the puma (Puma concolor (Mammalia, Felidae

    Directory of Open Access Journals (Sweden)

    Eunice M. Matte

    2013-01-01

    Full Text Available The puma is an iconic predator that ranges throughout the Americas, occupying diverse habitats. Previous phylogeographic analyses have revealed that it exhibits moderate levels of genetic structure across its range, with few of the classically recognized subspecies being supported as distinct demographic units. Moreover, most of the species' molecular diversity was found to be in South America. To further investigate the phylogeographic structure and demographic history of pumas we analyzed mtDNA sequences from 186 individuals sampled throughout their range, with emphasis on South America. Our objectives were to refine the phylogeographic assessment within South America and to investigate the demographic history of pumas using a coalescent approach. Our results extend previous phylogeographic findings, reassessing the delimitation of historical population units in South America and demonstrating that this species experienced a considerable demographic expansion in the Holocene, ca. 8,000 years ago. Our analyses indicate that this expansion occurred in South America, prior to the hypothesized re-colonization of North America, which was therefore inferred to be even more recent. The estimated demographic history supports the interpretation that pumas suffered a severe demographic decline in the Late Pleistocene throughout their distribution, followed by population expansion and re-colonization of the range, initiating from South America.

  20. Family History

    Science.gov (United States)

    Your family history includes health information about you and your close relatives. Families have many factors in common, including their genes, ... as heart disease, stroke, and cancer. Having a family member with a disease raises your risk, but ...

  1. Trauma history is associated with prior suicide attempt history in hospitalized patients with major depressive disorder.

    Science.gov (United States)

    Brown, Lily A; Armey, Michael A; Sejourne, Corinne; Miller, Ivan W; Weinstock, Lauren M

    2016-09-30

    Although the relationships between PTSD, abuse history, and suicidal behaviors are well-established in military and outpatient samples, little data is available on this relationship in inpatient samples. This study examines the relationships between these variables and related demographic and clinical correlates in a sample of psychiatric inpatients with a diagnosis of major depressive disorder using electronic medical record (EMR) data. Controlling for relevant demographic and clinical variables, PTSD diagnosis and history of abuse were both significantly associated with history of suicide attempt, but in a combined model, only history of abuse remained as a significant predictor. Whereas history of abuse was associated with a history multiple suicide attempts, PTSD diagnosis was not. Both insurance status and gender acted as significant moderators of the relationship between history of abuse and history of suicide attempt, with males and those with public/no insurance having greater associations with history of suicide attempts when an abuse history was present. These data indicate the importance of documentation of PTSD, abuse history, and history of suicide attempts. The results also suggest that in the presence of an abuse history or PTSD diagnosis, additional time spent on safety and aftercare planning following hospital discharge may be indicated. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  2. Aspiration of Barium Contrast

    Directory of Open Access Journals (Sweden)

    Cristina Fuentes Santos

    2014-01-01

    Full Text Available The aspiration of barium contrast is a rare complication that may occur during studies of the digestive tract. Barium is an inert material that can cause anywhere from an asymptomatic mechanical obstruction to serious symptoms of respiratory distress that can result in patient death. We present the case of a 79-year-old male patient in whom we observed the presence of contrast medium residue in the lung parenchyma as an incidental finding during hospitalization. When the patient’s medical file was reviewed, images were found of a barium swallow study that the patient had undergone months earlier, and we were able to observe the exact moment of the aspiration of the contrast material. The patient had been asymptomatic since the test.

  3. Digest: Demographic inferences accounting for selection at linked sites†.

    Science.gov (United States)

    Simon, Alexis; Duranton, Maud

    2018-05-16

    Complex demography and selection at linked sites can generate spurious signatures of divergent selection. Unfortunately, many attempts at demographic inference consider overly simple models and neglect the effect of selection at linked sites. In this issue, Rougemont and Bernatchez (2018) applied an approximate Bayesian computation (ABC) framework that accounts for indirect selection to reveal a complex history of secondary contacts in Atlantic salmon (Salmo salar) that might explain a high rate of latitudinal clines in this species. © 2018 The Author(s). Evolution © 2018 The Society for the Study of Evolution.

  4. Representation of Social History Factors Across Age Groups: A Topic Analysis of Free-Text Social Documentation.

    Science.gov (United States)

    Lindemann, Elizabeth A; Chen, Elizabeth S; Wang, Yan; Skube, Steven J; Melton, Genevieve B

    2017-01-01

    As individuals age, there is potential for dramatic changes in the social and behavioral determinants that affect health status and outcomes. The importance of these determinants has been increasingly recognized in clinical decision-making. We sought to characterize how social and behavioral health determinants vary in different demographic groups using a previously established schema of 28 social history types through both manual analysis and automated topic analysis of social documentation in the electronic health record across the population of an entire integrated healthcare system. Our manual analysis generated 8,335 annotations over 1,400 documents, representing 24 (86%) social history types. In contrast, automated topic analysis generated 22 (79%) social history types. A comparative evaluation demonstrated both similarities and differences in coverage between the manual and topic analyses. Our findings validate the widespread nature of social and behavioral determinants that affect health status over populations of individuals over their lifespan.

  5. The Natural History and Risk Factors of Musculoskeletal Conditions Resulting in Disability Among US Army Personnel

    National Research Council Canada - National Science Library

    Lincoln, Andrew

    2002-01-01

    We describe the natural history of 13 musculoskeletal conditions requiring hospitalization and identify demographic, behavioral, psychosocial, occupational, and clinical characteristics most strongly...

  6. Contrast media: future aspects

    International Nuclear Information System (INIS)

    Weinmann, H.J.; Platzek, J.; Schirmer, H.; Pietsch, H.; Carretero, J.; Harto, J.; Medina, J.; Riefke, B.; Martin, J.

    2005-01-01

    In spite of the dramatic development in CT, there was no major breakthrough in the iodinated contrast media development. New agents based on hybrid between MRI and CT compounds may be a new innovative alternative. This new approach may also open new indications such as radiotherapy. (orig.)

  7. Roentgen contrast medium

    International Nuclear Information System (INIS)

    Tamborski, C.

    1989-01-01

    The patent deals with a roentgen contrast medium containing a perfluorinebrominealkylether of the formula C m F 2m+1 OC n F 2n Br dispersed in water, preferentially in the presence of a non-ionic dispersing agent such as a fluorinated amidoaminoxide. 2 tabs

  8. High migration rates shape the postglacial history of amphi-Atlantic bryophytes.

    Science.gov (United States)

    Désamoré, Aurélie; Patiño, Jairo; Mardulyn, Patrick; Mcdaniel, Stuart F; Zanatta, Florian; Laenen, Benjamin; Vanderpoorten, Alain

    2016-11-01

    Paleontological evidence and current patterns of angiosperm species richness suggest that European biota experienced more severe bottlenecks than North American ones during the last glacial maximum. How well this pattern fits other plant species is less clear. Bryophytes offer a unique opportunity to contrast the impact of the last glacial maximum in North America and Europe because about 60% of the European bryoflora is shared with North America. Here, we use population genetic analyses based on approximate Bayesian computation on eight amphi-Atlantic species to test the hypothesis that North American populations were less impacted by the last glacial maximum, exhibiting higher levels of genetic diversity than European ones and ultimately serving as a refugium for the postglacial recolonization of Europe. In contrast with this hypothesis, the best-fit demographic model involved similar patterns of population size contractions, comparable levels of genetic diversity and balanced migration rates between European and North American populations. Our results thus suggest that bryophytes have experienced comparable demographic glacial histories on both sides of the Atlantic. Although a weak, but significant genetic structure was systematically recovered between European and North American populations, evidence for migration from and towards both continents suggests that amphi-Atlantic bryophyte population may function as a metapopulation network. Reconstructing the biogeographic history of either North American or European bryophyte populations therefore requires a large, trans-Atlantic geographic framework. © 2016 John Wiley & Sons Ltd.

  9. Iodinated contrast media nephrotoxicity

    International Nuclear Information System (INIS)

    Meyrier, A.

    1994-01-01

    In the late seventies, iodinated contrast agents (ICA) were considered to be a major cause of acute iatrogenic renal failure. Over the last decade new contrast agents have been synthesized, nonionic and less hyperosmolar. The incidence of acute renal failure due to ICAs, varies from 3.7 to 70% of cases according to the series, with an average figure of 10.2%. The pathophysiology of ICA nephrotoxicity was mainly studied in laboratory animal models. Three main factors are involved in an inducing ICA-mediated decrease in glomerular filtration rate: reduction of the renal plasma flow, a direct cytotoxic effect on renal tubular cells and erythrocyte alteration leading to intra-renal sludge. Excluding dysglobulinemias with urinary excretion of immunoglobulin light chains, which represent a special case of maximum nephrotoxicity, 4 main risk factors of renal toxicity have been identified in nondiabetic subjects: previous renal failure with serum creatinine levels greater than 140 μmol per liter, extracellular dehydration, age over 60 and use of high doses of ICA and/or repeated ICA injections before serum creatinine levels return to baseline. Preventive measures for avoiding ICA nephrotoxicity are threefold: maintain or restore adequate hydration with saline infusion, stop NSAID treatment several days before ICA administration, and allow a 5 day interval before repeating contrast media injections. New, nonionic and moderately hyperosmolar contrast agents appear to be much less nephrotoxic than conventional ICAs in laboratory animals and in high-risk patients. It is advisable to select such contrast media for investigating high-risk patients. This approach was recently substantiated in well designed, randomized clinical studies which included more than 2 000 patients. (author)

  10. Nephrogenic systemic fibrosis and gadolinium-based contrast media

    DEFF Research Database (Denmark)

    Thomsen, Henrik S; Morcos, Sameh K; Almén, Torsten

    2012-01-01

    PURPOSE: To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. AREAS COVERED: Topics reviewed include the history, clinical features and prevalence of neph...... guidelines regarding gadolinium contrast agents minimises the risk of NSF • Potential long-term harm from gadolinium accumulation in the body is discussed.......PURPOSE: To update the guidelines of the Contrast Media Safety Committee (CMSC) of the European Society of Urogenital Radiology (ESUR) on nephrogenic systemic fibrosis and gadolinium-based contrast media. AREAS COVERED: Topics reviewed include the history, clinical features and prevalence...... of nephrogenic systemic fibrosis and the current understanding of its pathophysiology. The risk factors for NSF are discussed and prophylactic measures are recommended. The stability of the different gadolinium-based contrast media and the potential long-term effects of gadolinium in the body have also been...

  11. Demographic and Economic Changes and Postsecondary Education.

    Science.gov (United States)

    Charner, Ivan

    The interaction of demographic and economic shifts has led to, and will continue to effect, changes in the postsecondary education system and institutions. Demographic shifts include aging of the population, more women in the paid labor force, and increased numbers of minorities. Economic shifts include the growth of the information sector,…

  12. Is there a Demographic Time-bomb?

    DEFF Research Database (Denmark)

    Greve, Bent

    2006-01-01

    The article discuss whether the demographic transition in Europe will have any impact on the future of the European welfare states......The article discuss whether the demographic transition in Europe will have any impact on the future of the European welfare states...

  13. Demographic transitions in Europe and the world

    NARCIS (Netherlands)

    Willekens, Frans

    The demographic transition is a universal phenomenon. All regions of the world experience a change from high levels of mortality and fertility to low levels. The onset and pace of the demographic transition vary between regions and countries because of differences in timing of events and conditions

  14. 5 CFR 841.404 - Demographic factors.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Demographic factors. 841.404 Section 841.404 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT (CONTINUED) CIVIL SERVICE REGULATIONS (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.404 Demographic...

  15. Demographic transitions in Europe and the world

    NARCIS (Netherlands)

    Willekens, F.J.; Matthijs, K.; Neels, K.; Timmerman, C.; Haers, J.; Mels, S.

    2016-01-01

    Willekens, F. (2015) Demographic transitions in Europe and the world. In: K. Matthijs, K. Neels, C. Timmerman. J. Haers and S. Mels eds. Population change at work in Europe, the Middle-East and North Africa. Beyond the demographic divide. Ashgate (International Population Studies Series) pp. 13-44.

  16. Environmental history

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2017-01-01

    Environmental history is an interdisciplinary pursuit that has developed as a form of conscience to counter an increasingly powerful, forward-looking liberal theory of the environment. It deals with the relations between environmental ideas and materialities, from the work of the geographers George...... risks”. These are exposed by environmental history’s focus on long-run analysis and its narrative form that identifies the stories that we tell ourselves about nature. How a better understanding of past environmental transformations helps to analyse society and agency, and what this can mean...... for solutions and policies, is the agenda for an engaged environmental history from now on....

  17. Ildens historier

    DEFF Research Database (Denmark)

    Lassen, Henrik Roesgaard

    have been written by Andersen. In several chapters the curiously forgotten history of fire-lighting technology is outlined, and it is demonstrated that "Tællelyset" is written by a person with a modern perspective on how to light a candle - among other things. The central argument in the book springs...... from a point-by-point tracing of 'the origins and history' of Hans Christian Andersen's famous fairy tales. Where did the come from? How did they become the iconic texts that we know today? On this background it becomes quite clear that "Tællelyset" is a modern pastiche and not a genuine Hans Christian...

  18. Mamografia com contraste

    OpenAIRE

    Baptista, Rita; Silva, Carina; Reis, Cláudia

    2016-01-01

    O estudo pretendeu apresentar as indicações clínicas, vantagens e princípios da mamografia com contraste, identificar as evoluyções tecnológicas para a mamografia com contraste e caracterizar as práticas e os desafios dos técnicos de radiologia do Hospital de Santarém (único no país a utilizar esta técnica). O cancro da mama é uma das principais causas de morte nas mulheres, em todo o mundo, mas principalmente nos Estados Unidos da América, Canadá, Europa Ocidental e Austrália. Em Portugal, e...

  19. Current iodinated contrast media

    International Nuclear Information System (INIS)

    Stacul, F.

    2001-01-01

    The number of scientific papers on iodinated contrast media is declining. Indeed, comparative trials between high-osmolality and low-osmolality agents largely showed the higher safety and tolerability of the latter, and this is no longer a matter of discussion. Only financial constraints could prevent a total conversion to low-osmolality agents. Research comparing low-osmolality (nonionic monomers, ionic dimer) and iso-osmolality contrast media (nonionic dimers) are still ongoing. Both classes of nonionic compounds proved safer than the ionic dimer. The relative merits of nonionic monomers and nonionic dimers are a matter for debate, and criteria for a selective use of different agents for different procedures could be discussed. (orig.)

  20. Contrasting genetic structure in two co-distributed species of old world fruit bat.

    Directory of Open Access Journals (Sweden)

    Jinping Chen

    2010-11-01

    Full Text Available The fulvous fruit bat (Rousettus leschenaulti and the greater short-nosed fruit bat (Cynopterus sphinx are two abundant and widely co-distributed Old World fruit bats in Southeast and East Asia. The former species forms large colonies in caves while the latter roots in small groups in trees. To test whether these differences in social organization and roosting ecology are associated with contrasting patterns of gene flow, we used mtDNA and nuclear loci to characterize population genetic subdivision and phylogeographic histories in both species sampled from China, Vietnam and India. Our analyses from R. leschenaulti using both types of marker revealed little evidence of genetic structure across the study region. On the other hand, C. sphinx showed significant genetic mtDNA differentiation between the samples from India compared with China and Vietnam, as well as greater structuring of microsatellite genotypes within China. Demographic analyses indicated signatures of past rapid population expansion in both taxa, with more recent demographic growth in C. sphinx. Therefore, the relative genetic homogeneity in R. leschenaulti is unlikely to reflect past events. Instead we suggest that the absence of substructure in R. leschenaulti is a consequence of higher levels of gene flow among colonies, and that greater vagility in this species is an adaptation associated with cave roosting.

  1. Oromandibular Dystonia: Demographics and Clinical Data from 240 Patients

    Directory of Open Access Journals (Sweden)

    Linda Slaim

    2018-05-01

    Full Text Available Objective To report demographic data from a large cohort of patients with oromandibular dystonia (OMD. Methods This is a retrospective review of patients with OMD referred to our institution between 1989 and 2015. Demographic (age of onset, gender, and familial history of dystonia and clinical (type of OMD, associated dystonia, and etiology of dystonia data were collected from a cohort of 240 individuals. Results The mean age of onset of OMD was 51.6 years old, with a female predominance (2:1. A family history of dystonia was found in 6 patients (2.5%. One hundred and forty-nine patients (62.1% had the jaw-opening type of OMD, 48 patients (20.0% had the jaw-closing type, and 43 patients (17.9% had a mixed form of OMD. Lingual dystonia was also present in 64 (26.7% of these patients. Eighty-two patients (34.2% had a focal dystonia, 131 patients (54.6% had a segmental dystonia, and 27 patients (11.3% had a generalized dystonia. One hundred and seventy-one patients (71.3% had idiopathic OMD. Conclusion OMD is a chronic and disabling focal dystonia. Our study found a prevalence of female patients, an onset in middle age and a predominantly idiopathic etiology. Unlike other studies, jaw-opening was found to be the most frequent clinical type of OMD.

  2. Anisotropic contrast optical microscope.

    Science.gov (United States)

    Peev, D; Hofmann, T; Kananizadeh, N; Beeram, S; Rodriguez, E; Wimer, S; Rodenhausen, K B; Herzinger, C M; Kasputis, T; Pfaunmiller, E; Nguyen, A; Korlacki, R; Pannier, A; Li, Y; Schubert, E; Hage, D; Schubert, M

    2016-11-01

    An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm 2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves

  3. Demographic Ranking of the Baltic Sea States

    Directory of Open Access Journals (Sweden)

    Sluka N.

    2014-06-01

    Full Text Available The relevance of the study lies in the acute need to modernise the tools for a more accurate and comparable reflection of the demographic reality of spatial objects of different scales. This article aims to test the methods of “demographic rankings” developed by Yermakov and Shmakov. The method is based on the principles of indirect standardisation of the major demographic coefficients relative to the age structure.The article describes the first attempt to apply the method to the analysis of birth and mortality rates in 1995 and 2010 for 140 countries against the global average, and for the Baltic Sea states against the European average. The grouping of countries and the analysis of changes over the given period confirmed a number of demographic development trends and the persistence of wide territorial disparities in major indicators. The authors identify opposite trends in ranking based on the standardised birth (country consolidation at the level of averaged values and mortality (polarisation rates. The features of demographic process development in the Baltic regions states are described against the global and European background. The study confirmed the validity of the demographic ranking method, which can be instrumental in solving not only scientific but also practical tasks, including those in the field of demographic and social policy.

  4. Business History

    DEFF Research Database (Denmark)

    Hansen, Per H.

    2012-01-01

    This article argues that a cultural and narrative perspective can enrich the business history field, encourage new and different questions and answers, and provide new ways of thinking about methods and empirical material. It discusses what culture is and how it relates to narratives. Taking...

  5. LCA History

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikołaj; Molin, Christine

    2018-01-01

    The idea of LCA was conceived in the 1960s when environmental degradation and in particular the limited access to resources started becoming a concern. This chapter gives a brief summary of the history of LCA since then with a focus on the fields of methodological development, application...

  6. Rewriting History.

    Science.gov (United States)

    Ramirez, Catherine Clark

    1994-01-01

    Suggests that the telling of vivid stories can help engage elementary students' emotions and increase the chances of fostering an interest in Texas history. Suggests that incorporating elements of the process approach to writing can merge with social studies objectives in creating a curriculum for wisdom. (RS)

  7. Population momentum across vertebrate life histories

    Science.gov (United States)

    Koons, D.N.; Grand, J.B.; Arnold, J.M.

    2006-01-01

    Population abundance is critically important in conservation, management, and demographic theory. Thus, to better understand how perturbations to the life history affect long-term population size, we examined population momentum for four vertebrate classes with different life history strategies. In a series of demographic experiments we show that population momentum generally has a larger effect on long-term population size for organisms with long generation times than for organisms with short generation times. However, patterns between population momentum and generation time varied across taxonomic groups and according to the life history parameter that was changed. Our findings indicate that momentum may be an especially important aspect of population dynamics for long-lived vertebrates, and deserves greater attention in life history studies. Further, we discuss the importance of population momentum in natural resource management, pest control, and conservation arenas. ?? 2006 Elsevier B.V. All rights reserved.

  8. Genetic demographic networks: Mathematical model and applications.

    Science.gov (United States)

    Kimmel, Marek; Wojdyła, Tomasz

    2016-10-01

    Recent improvement in the quality of genetic data obtained from extinct human populations and their ancestors encourages searching for answers to basic questions regarding human population history. The most common and successful are model-based approaches, in which genetic data are compared to the data obtained from the assumed demography model. Using such approach, it is possible to either validate or adjust assumed demography. Model fit to data can be obtained based on reverse-time coalescent simulations or forward-time simulations. In this paper we introduce a computational method based on mathematical equation that allows obtaining joint distributions of pairs of individuals under a specified demography model, each of them characterized by a genetic variant at a chosen locus. The two individuals are randomly sampled from either the same or two different populations. The model assumes three types of demographic events (split, merge and migration). Populations evolve according to the time-continuous Moran model with drift and Markov-process mutation. This latter process is described by the Lyapunov-type equation introduced by O'Brien and generalized in our previous works. Application of this equation constitutes an original contribution. In the result section of the paper we present sample applications of our model to both simulated and literature-based demographies. Among other we include a study of the Slavs-Balts-Finns genetic relationship, in which we model split and migrations between the Balts and Slavs. We also include another example that involves the migration rates between farmers and hunters-gatherers, based on modern and ancient DNA samples. This latter process was previously studied using coalescent simulations. Our results are in general agreement with the previous method, which provides validation of our approach. Although our model is not an alternative to simulation methods in the practical sense, it provides an algorithm to compute pairwise

  9. Contrast Invariant SNR

    DEFF Research Database (Denmark)

    Weiss, Pierre; Escande, Paul; Dong, Yiqiu

    We design an image quality measure independent of local contrast changes, which constitute simple models of illumination changes. Given two images, the algorithm provides the image closest to the first one with the component tree of the second. This problem can be cast as a specific convex progra...... algorithms based on interior point methods. The algorithm has potential applications in change detection, color image processing or image fusion. A Matlab implementation is available at http://www.math.univ-toulouse.fr/_weiss/PageCodes.html....

  10. Climatic conditions cause complex patterns of covariation between demographic traits in a long-lived raptor

    NARCIS (Netherlands)

    Herfindal, Ivar; van de Pol, Martijn; Nielsen, Jan Tøttrup; Sæther, Bernt-Erik; Møller, Anders Pape

    2015-01-01

    1.Environmental variation can induce life history changes that can last over a large part of the lifetime of an organism. If multiple demographic traits are affected, expected changes in climate may influence environmental covariances among traits in a complex manner. Thus, examining the

  11. Business History as Cultural History

    DEFF Research Database (Denmark)

    Lunde Jørgensen, Ida

    The paper engages with the larger question of how cultural heritage becomes taken for granted and offers a complimentary view to the anthropological ʻCopenhagen School’ of business history, one that draws attention to the way corporate wealth directly and indirectly influences the culture available...

  12. Complexity and demographic explanations of cumulative culture

    NARCIS (Netherlands)

    Querbes, A.; Vaesen, K.; Houkes, W.N.

    2014-01-01

    Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological

  13. Lethality and Autonomous Systems: The Roboticist Demographic

    National Research Council Canada - National Science Library

    Moshkina, Lilia V; Arkin, Ronald C

    2008-01-01

    .... Army Research Office. The robotics researcher demographic, one of several targeted in this survey that includes policy makers, the military, and the general public, provides the data for this report...

  14. Demographic Characteristics Related To Wholesale Marketing Of ...

    African Journals Online (AJOL)

    Demographic Characteristics Related To Wholesale Marketing Of Yam In Delta State, Nigeria. ... analysis reveals that wholesale yam marketing in the study area was male - dominated (78.8%), most of ... EMAIL FULL TEXT EMAIL FULL TEXT

  15. Rural Household Demographics, Livelihoods and the Environment

    OpenAIRE

    de Sherbinin, Alex; VanWey, Leah; McSweeney, Kendra; Aggarwal, Rimjhim; Barbieri, Alisson; Henry, Sabina; Hunter, Lori M.; Twine, Wayne

    2008-01-01

    This paper reviews and synthesizes findings from scholarly work on linkages among rural household demographics, livelihoods and the environment. Using the livelihood approach as an organizing framework, we examine evidence on the multiple pathways linking environmental variables and the following demographic variables: fertility, migration, morbidity and mortality, and lifecycles. Although the review draws on studies from the entire developing world, we find the majority of micro-level studie...

  16. Gender inequalities from the demographic perspective

    Directory of Open Access Journals (Sweden)

    Devedžić Mirjana

    2006-01-01

    Full Text Available The paper analyzes the meaning of the phrase "the woman’s status in the society" that is recognized in demography as an important cultural factor of demographic development and transitional changes. The analysis indicates qualitative shifts in the woman’s status and simultaneously reveals its importance at present, not only in traditional, but also in modern and developed societies. On the other hand, it explains the importance of sex as a biodemographic determinant, and introduces the concept of gender that sheds another light on the concepts of sex and woman’s status in the society and integrates them. Gender regimes that subsume the inferiority of women in public and private social structures are examined from demographic perspective, albeit only in those phenomenological aspects that can be supported by demographic research, theories, and analyses. To this end, the paper analyzes the effects of strengthening gender equalities on the fertility and mortality transitions, the gender’s impact on the population distribution by sex in South Asian countries, and highlights the key role of gender in interpreting certain social and economic structures. It also stresses the establishing of gender equality as an important element of population policies. The global dimension of the patriarchal society is illustrated through a series of examples of demographic phenomena from various societies. Gender regimes underlie all of these phenomena. The paper puts foreword certain theoretical hypotheses about gender inequalities, and finds their connections with demographic behaviors and demographic indicators. Finally, it summarizes the role of demography in gender (inequality research and the demographic perspective of the way and the speed the demographic equality is being established. Demography is seen as an irreplaceable discipline in examining gender inequalities, especially at the global level. With the advance of qualitative methods in demography

  17. Clinical survey on adverse reaction of contrast media, final report

    International Nuclear Information System (INIS)

    Katayama, Hitoshi; Ishida, Osamu; Osawa, Tadashi

    1988-01-01

    This report is a final analysis of adverse reactions to iodinated contrast media examined in 33,440 patients from 11 hospitals during the period from October 1983 through June 1986. Adverse reactions, such as nausea, exanthema and vomiting, to contrast media occurred in 2,523 patients (7.5 %), with the higher number occuring in patients aged 40 - 60, irrespective of sex. There were no significant alternations in vital signs. Patients positive for pretesting and having a history of allergy had higher incidences of adverse reactions (48 % and 52 %, respectively). A history of allergy is the most potential predictor for adverse reactions to contrast media. There was no definitive correlation between prior medication of contrast media and the occurrence of their adverse reactions. The relationship between the occurrence of adverse reactions and both kinds and dosage of contrast media was unknown. (Namekawa, K.)

  18. River history.

    Science.gov (United States)

    Vita-Finzi, Claudio

    2012-05-13

    During the last half century, advances in geomorphology-abetted by conceptual and technical developments in geophysics, geochemistry, remote sensing, geodesy, computing and ecology-have enhanced the potential value of fluvial history for reconstructing erosional and depositional sequences on the Earth and on Mars and for evaluating climatic and tectonic changes, the impact of fluvial processes on human settlement and health, and the problems faced in managing unstable fluvial systems. This journal is © 2012 The Royal Society

  19. Environmental History

    OpenAIRE

    Kearns, Gerard

    2004-01-01

    There was a time when almost all Western geography could be termed environmental history. In the late nineteenth century, physical geographers explained landscapes by describing how they had evolved. Likewise, human geographers saw society as shaped by the directing hands of the environment. By the 1960s this had very much changed. Process studies shortened the temporal framework in geographical explanation and cut the cord between nature and society. Now, physical and human...

  20. [Demographic transition or revolution? The weaknesses and implications of the demographic transition theory. Part 1: the origins].

    Science.gov (United States)

    Bourcier De Carbon, P

    1998-01-01

    The work of Adolphe Landry is reviewed in relation to development of demographic transition theory. Landry was appointed administrator in 1912 of the National Alliance Against Depopulation and remained active in it his whole life. He also helped create family allowance programs in France. As early as 1909, Landry described three different population regimes. In the "primitive" regime, which characterized all nonhuman life and human life during most of history, the population was adjusted to available subsistence by mortality. In the "intermediate" phase, restrictions on marriage and control of reproduction outside marriage maintained the population at a level below the maximum supportable. In the "contemporary" regime, the universal practice of contraception and abortion could lead to very low levels of fertility. The spread of contraception and low fertility appeared to Landry a true demographic revolution. He attributed the acceptance of contraception to a change in the common aspirations of human beings regarding their conditions, a desire for improved material well-being and social advancement, and an increased spirit of rationality and even calculation in their behavior. Landry believed that the contemporary regime, unlike the preceding two, had no mechanism implying equilibrium. The demographic revolution freed fertility from social determinants and linked it more closely to individual interests. Landry expected the contemporary regime to spread throughout the entire world, with many areas still in the primitive phase passing directly to the contemporary. He was concerned with the effects of demographic aging, and he deplored birth control propaganda that claimed it as a cure for unemployment and for overpopulation in the poor Asian countries. The birth control movements in England and the US were successful in bringing the two countries into the contemporary regime. A number of organizations such as the Population Association of America and the Office of

  1. Prevention of adverse reactions to intravascular contrast media

    International Nuclear Information System (INIS)

    Soyer, P.; Levesque, M.

    1990-01-01

    The exact mechanisms of adverse reactions to contrast media are still imperfectly known. However, these reactions may be classified as idiosyncratic. Non-idiosyncratic reactions can be prevented by using new, non-ionic contrast agents. Idiosyncratic reactions can be prevented by specific premedication. Patients with a history of idiosyncratic reaction may benefit from corticosteroids and antihistamines administered prophylactically. Patients who seem to be more likely than others to react to contrast media must be premedicated, the risk of reaction being identified and evaluated by questioning. It has recently been suggested that all patients about to receive an intravascular injection of contrast medium should also be premedicated [fr

  2. Phase Contrast Imaging

    DEFF Research Database (Denmark)

    1996-01-01

    The invention relates to a method and a system for synthesizing a prescribed intensity pattern based on phase contrast imaging that is not based on the assumption of prior art methods that the pahase shift phi is less than 1 radian. An improved method based on a simple imaging operation...... phasors attain predetermined values for predetermined spatial frequencies, and the phasor value of the specific resolution element of the spatial phase mask corresponds to a distinct intensity level of the image of the resolution element in the intensity pattern, and a spatial phase filter for phase...... shifting of a part of the electromagntic radiation, in combination with an imaging system for generation of the intensity pattern by interference in the image plane of the imaging system between the part of the electromagnetic raidation that has been phase shifted by the phase filter and the remaining part...

  3. Paramagnetic contrast material

    International Nuclear Information System (INIS)

    McNamara, M.T.

    1987-01-01

    Paramagnetic contrast materials have certainly demonstrated clinical utility in a variety of organ systems for improved detection of various neoplastic, inflammatory, infectious, and physiologic abnormalities. Although the more commonly employed extracellular agents, such as Gd-DTPA, have been quite safe and useful, particularly in the CNS, it is almost certain that other substances will achieve more success in various other organs, such as iron oxides in the reticuloendothelial system and persisting extracellular agents in the cardiovascular system. Finally, as MRI technology continues to evolve, producing such exciting new sequences as gradient-echo fast scans, the roles of currently existing and newly discovered paramagnetic pharmaceuticals must be continuously reevaluated both to obtain maximum clinical benefit and to guide the search for newer agents that may further optimize the diagnostic efficacy of MRI

  4. New MR contrast agent

    International Nuclear Information System (INIS)

    Grossman, C.D.; Subramanian, G.; Schneider, R.; Szeverenyi, N.E.; Rosenbaum, A.M.; Gagne, G.; Tillapaugh-Fay, G.; Berlin, R.; Ritter-Hrncirik, C.; Yu, S.

    1990-01-01

    This paper evaluates an MR contrast agent-meglumine tris-(2,6-dicarboxypyridine) gadolinium (III) or gadolinium dipicolinate (Gd-DPC)-produced in-house. Rats were anesthetized with pentobarbital. For renal imaging, bowel motion artifact was minimized with glucagon (0.014 mg/kg, intravenous (IV)). Enhanced images were generated on a 2-T chemical shift imaging system with a 31-cm horizontal bore magnet after IV injection of Gd-DPC (100 μM/kg). Coronal sections of the kidneys and sagittal sections of the brain, 2 mm thick, were made. Six to eight excitations and 128 or 356 phase-encoding steps were used for each image. Control animals were injected with equivalent doses of gadopentetate dimeglumine

  5. Uncovering History for Future History Teachers

    Science.gov (United States)

    Fischer, Fritz

    2010-01-01

    The art of history teaching is at a crossroads. Recent scholarship focuses on the need to change the teaching of history so students can better learn history, and insists that history teachers must move beyond traditional structures and methods of teaching in order to improve their students' abilities to think with history. This article presents…

  6. Demographic aspects of social security in region

    Directory of Open Access Journals (Sweden)

    Alla Gennad'evna Leont'eva

    2012-06-01

    Full Text Available This paper presents a situational analysis of the level of life safety in the field of demographic regions of the Ural Federal District. The analysis is based on data from the Federal Statistics and covers the period 2000-2010. We have developed a system of indicators for evaluating safety in the demographic sphere. We set the main threats to the social and economic stability in the regions. The system of thresholds includes three blocks: the reproduction of the population, marriage and family relationships and health. We have presented a quantitative description of the main threats. Identified priority areas of social protection, providing increased stability of the regional socio-economic development, reducing the likelihood of social conflicts and improve the demographic situation.

  7. A unified framework of demographic time

    DEFF Research Database (Denmark)

    Riffe, Tim; Schöley, Jonas; Villavicencio, Francisco

    Demographic thought and practice is largely conditioned by the Lexis diagram, a two-dimensional graphical representation of the identity between age, period, and birth cohort. This relationship does not account for remaining years of life or other related time measures, whose use in demographic...... research is both underrepresented and incompletely situated. We describe a three-dimensional relationship between six different measures of demographic time: chronological age, time to death, lifespan, time of birth, time of death, and period. We describe four identities among subsets of these six measures......, and a full identity that relates the six of them. One of these identities is the age-period-cohort identity, while the other three are relatively novel. We provide a topological overview of the diagrams that pertain to these identities. The 3-d geometric representation of the full six-way identity...

  8. [The beginning of the Cuban demographic revolution].

    Science.gov (United States)

    Hernandez Castellon, R

    1981-01-01

    The characteristics of the Cuban demographic revolution associated with the main economic, political, and social changes in the country are analyzed. The authors begin with a brief historical outline of the political-economic situation in the country in the middle of the 19th century. There is emphasis on the dependency of the Cuban economy and its monoproducer nature (with sugar being the major export). This was due to the Spanish colonization and to the subsequent American neocolonization. The discovery of the cause for yellow fever by a Cuban physician and the sanitation campaign conducted by the Americans contributed to a diminishing of mortality. A great migratory flow occurred due to the price of sugar in the world market. This must have influenced Cuban demographic patterns which are a major factor linked to the demographic revolution. The influence on proliferation of urbanization and educational trends is emphasized. The low participation in economic activities of women during the early part of the century did affect fertility levels. The trends in mortality throughout the period 1907-43 are pointed out. It was found that 1 major aspect which had a bearing on Cuban demographic patterns was the 2 large migratory flows. An analysis of growth rates in the population--which also confirms the demographic changes in Cuba--is presented. It is concluded that the 4th decade of this century witnessed Cuba's entry in a new stage of the demographic revolution, a stage in which decreased fertility and mortality go together to create a new period. (author's)

  9. Using demographic characteristics of populations to detect spatial fragmentation following suspected ebola outbreaks in great apes.

    Science.gov (United States)

    Genton, Céline; Cristescu, Romane; Gatti, Sylvain; Levréro, Florence; Bigot, Elodie; Motsch, Peggy; Le Gouar, Pascaline; Pierre, Jean-Sébastien; Ménard, Nelly

    2017-09-01

    Demographic crashes due to emerging diseases can contribute to population fragmentation and increase extinction risk of small populations. Ebola outbreaks in 2002-2004 are suspected to have caused a decline of more than 80% in some Western lowland gorilla (Gorilla gorilla gorilla) populations. We investigated whether demographic indicators of this event allowed for the detection of spatial fragmentation in gorilla populations. We collected demographic data from two neighbouring populations: the Lokoué population, suspected to have been affected by an Ebola outbreak (followed from 2001 to 2014), and the Romani population, of unknown demographic status before Ebola outbreaks (followed from 2005 to 2014). Ten years after the outbreak, the Lokoué population is slowly recovering and the short-term demographic indicators of a population crash were no longer detectable. The Lokoué population has not experienced any additional demographic perturbation over the past decade. The Romani population did not show any of the demographic indicators of a population crash over the past decade. Its demographic structure remained similar to that of unaffected populations. Our results highlighted that the Ebola disease could contribute to fragmentation of gorilla populations due to the spatially heterogeneous impact of its outbreaks. The demographic structure of populations (i.e., age-sex and group structure) can be useful indicators of a possible occurrence of recent Ebola outbreaks in populations without known history, and may be more broadly used in other emerging disease/species systems. Longitudinal data are critical to our understanding of the impact of emerging diseases on wild populations and their conservation. © 2017 Wiley Periodicals, Inc.

  10. Demographics, political power and economic growth.

    Science.gov (United States)

    Holtz-eakin, D

    1993-01-01

    "Growth theory may be used to predict the response of saving, capital formation, and output growth to large demographic shifts. Such large shifts would also be expected to alter the demand for government services and the desired levels of taxation in the population. This paper extends the overlapping-generations model of economic growth to predict the evolution of government tax and spending policy through the course of a major demographic shift. Simulations suggest that this approach may yield valuable insights into the evolution of policy in the United States and other industrialized economies." excerpt

  11. Prevalence, demographics and clinical characteristics of multiple sclerosis in Qatar.

    Science.gov (United States)

    Deleu, Dirk; Mir, Danial; Al Tabouki, Ahmed; Mesraoua, Rim; Mesraoua, Boulenouar; Akhtar, Naveed; Al Hail, Hassan; D'souza, Atlantic; Melikyan, Gayane; Imam, Yahia Z B; Osman, Yasir; Elalamy, Osama; Sokrab, Tageldin; Kamran, Sadaat; Ruiz Miyares, Francisco; Ibrahim, Faiza

    2013-05-01

    No published epidemiologic data on multiple sclerosis (MS) in Qatar exist. Our objectives were to determine the prevalence, demographics and clinical characteristics of MS in the Middle Eastern country of Qatar. We analyzed data for Qatari MS patients fulfilling the McDonald diagnostic criteria. A total of 154 patients fulfilled the inclusion criteria. On 31 April 2010, the crude prevalence of MS in Qatar was 64.57 per 100,000 inhabitants (95% CI: 58.31-70.37). The female-to-male ratio was 1.33:1. A positive family history was found in 10.4% of included MS patients. We conclude that Qatar is now a medium-to-high risk area for MS, with some important differences in clinical characteristics as compared to other countries in the region.

  12. Robust Demographic Inference from Genomic and SNP Data

    Science.gov (United States)

    Excoffier, Laurent; Dupanloup, Isabelle; Huerta-Sánchez, Emilia; Sousa, Vitor C.; Foll, Matthieu

    2013-01-01

    We introduce a flexible and robust simulation-based framework to infer demographic parameters from the site frequency spectrum (SFS) computed on large genomic datasets. We show that our composite-likelihood approach allows one to study evolutionary models of arbitrary complexity, which cannot be tackled by other current likelihood-based methods. For simple scenarios, our approach compares favorably in terms of accuracy and speed with , the current reference in the field, while showing better convergence properties for complex models. We first apply our methodology to non-coding genomic SNP data from four human populations. To infer their demographic history, we compare neutral evolutionary models of increasing complexity, including unsampled populations. We further show the versatility of our framework by extending it to the inference of demographic parameters from SNP chips with known ascertainment, such as that recently released by Affymetrix to study human origins. Whereas previous ways of handling ascertained SNPs were either restricted to a single population or only allowed the inference of divergence time between a pair of populations, our framework can correctly infer parameters of more complex models including the divergence of several populations, bottlenecks and migration. We apply this approach to the reconstruction of African demography using two distinct ascertained human SNP panels studied under two evolutionary models. The two SNP panels lead to globally very similar estimates and confidence intervals, and suggest an ancient divergence (>110 Ky) between Yoruba and San populations. Our methodology appears well suited to the study of complex scenarios from large genomic data sets. PMID:24204310

  13. Cygnus History

    International Nuclear Information System (INIS)

    Henderson, David J.; Gignac, Raymond E.; Good, Douglas E.; Hansen, Mark D.; Mitton, Charles V.; Nelson, Daniel S.; Ormond, Eugene C.; Cordova, Steve R.; Molina, Isidro; Smith, John R.; Rose, Evan A.

    2009-01-01

    The Cygnus Dual Beam Radiographic Facility consists of two identical radiographic sources: Cygnus 1 and Cygnus 2. This Radiographic Facility is located in an underground tunnel test area at the Nevada Test Site. The sources were developed to produce high-resolution images for dynamic plutonium experiments. This work will recount and discuss salient maintenance and operational issues encountered during the history of Cygnus. A brief description of Cygnus systems and rational for design selections will set the stage for this historical narrative. It is intended to highlight the team-derived solutions for technical problems encountered during extended periods of maintenance and operation. While many of the issues are typical to pulsed power systems, some of the solutions are unique. It is hoped that other source teams will benefit from this presentation, as well as other necessary disciplines (e.g., source users, system architects, facility designers and managers, funding managers, and team leaders)

  14. Environmental history

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2017-01-01

    Environmental history is an interdisciplinary pursuit that has developed as a form of conscience to counter an increasingly powerful, forward-looking liberal theory of the environment. It deals with the relations between environmental ideas and materialities, from the work of the geographers George...... Perkins Marsh, Carl Sauer, and Clarence Glacken, to more recent global-scale assessments of the impact of the “great acceleration” since 1950. Today’s “runaway world” paradoxically embraces risk management in an attempt to determine its own future whilst generating a whole new category of “manufactured...... risks”. These are exposed by environmental history’s focus on long-run analysis and its narrative form that identifies the stories that we tell ourselves about nature. How a better understanding of past environmental transformations helps to analyse society and agency, and what this can mean...

  15. Phase Contrast Imaging

    International Nuclear Information System (INIS)

    Menk, Ralf Hendrik

    2008-01-01

    All standard (medical) x-ray imaging technologies, rely primarily on the amplitude properties of the incident radiation, and do not depend on its phase. This is unchanged since the discovery by Roentgen that the intensity of an x-ray beam, as measured by the exposure on a film, was related to the relative transmission properties of an object. However, recently various imaging techniques have emerged which depend on the phase of the x-rays as well as the amplitude. Phase becomes important when the beam is coherent and the imaging system is sensitive to interference phenomena. Significant new advances have been made in coherent optic theory and techniques, which now promise phase information in medical imaging. The development of perfect crystal optics and the increasing availability of synchrotron radiation facilities have contributed to a significant increase in the application of phase based imaging in materials and life sciences. Unique source characteristics such as high intensity, monochromaticity, coherence and high collimating provide an ideal source for advanced imaging. Phase contrast imaging has been applied in both projection and computed tomography modes, and recent applications have been made in the field of medical imaging. Due to the underlying principle of X-ray detection conventional image receptors register only intensities of wave fields and not their phases. During the last decade basically five different methods were developed that translate the phase information into intensity variations. These methods are based on measuring the phase shift φ directly (using interference phenomena), the gradient ∇ φ , or the Laplacian ∇ 2 φ. All three methods can be applied to polychromatic X-ray sources keeping in mind that the native source is synchrotron radiation, featuring monochromatic and reasonable coherent X-ray beams. Due to the vast difference in the coefficients that are driven absorption and phase effects (factor 1,000-10,000 in the energy

  16. Visualising the demographic factors which shape population age structure

    Directory of Open Access Journals (Sweden)

    Tom Wilson

    2016-09-01

    Full Text Available Background: The population pyramid is one of the most popular tools for visualising population age structure. However, it is difficult to discern from the diagram the relative effects of different demographic components on the size of age-specific populations, making it hard to understand exactly how a population's age structure is formed. Objective: The aim of this paper is to introduce a type of population pyramid which shows how births, deaths, and migration have shaped a population's age structure. Methods: Births, deaths, and population data were obtained from the Human Mortality Database and the Australian Bureau of Statistics. A variation on the conventional population pyramid, termed here a components-of-change pyramid, was created. Based on cohort population accounts, it illustrates how births, deaths, and net migration have created the population of each age group. A simple measure which summarises the impact of net migration on age structure is also suggested. Results: Example components-of-change pyramids for several countries and subnational regions are presented, which illustrate how births, deaths, and net migration have fashioned current population age structures. The influence of migration is shown to vary greatly between populations. Conclusions: The new type of pyramid aids interpretation of a population's age structure and helps to understand its demographic history over the last century.

  17. "ALS reversals": demographics, disease characteristics, treatments, and co-morbidities.

    Science.gov (United States)

    Harrison, Daniel; Mehta, Paul; van Es, Michael A; Stommel, Elijah; Drory, Vivian E; Nefussy, Beatrice; van den Berg, Leonard H; Crayle, Jesse; Bedlack, Richard

    2018-04-02

    To identify differences in demographics, disease characteristics, treatments, and co-morbidities between patients with "amyotrophic lateral sclerosis (ALS) reversals" and those with typically progressive ALS. Cases of possible ALS reversals were found in prior publications, in the Duke ALS clinic, through self-referral or referral from other Neurologists, and on the internet. Of 89 possible reversals identified, 36 cases were included because chart or literature review confirmed their diagnosis and a robust, sustained improvement in at least one objective measure. Controls were participants in the Pooled Resource Open-Access ALS Clinical Trials database and the National ALS Registry. Cases and controls were compared using descriptive statistics. ALS reversals were more likely to be male, have limb onset disease, and initially progress faster. The prevalences of myasthenia gravis (MG) and purely lower motor neuron disease in cases were higher than estimates of these prevalences in the general population. The odds of taking curcumin, luteolin, cannabidiol, azathioprine, copper, glutathione, vitamin D, and fish oil were greater for cases than controls. When compared to patients with typically progressive ALS, patients with reversals differed in their demographics, disease characteristics, and treatments. While some of these patients may have had a rare antibody-mediated ALS mimicker, such as atypical myasthenia gravis, details of their exams, EMGs and family histories argue that this was unlikely. Instead, our data suggest that ALS reversals warrant evaluation for mechanisms of disease resistance and that treatments associated with multiple ALS reversals deserve further study.

  18. From Demographic Dividend to Demographic Burden? : Regional Trends of Population Aging in Russia

    OpenAIRE

    Matytsin, Mikhail; Moorty, Lalita; Richter, Kaspar

    2015-01-01

    Do regions with higher working age populations grow faster? This paper examines this question using data from Russian regions and finds evidence that demographic trends influence regional growth convergence. In other words, keeping other factors constant, poorer regions grow faster than richer regions, and some of the growth convergence is explained by demographic changes: faster growth in...

  19. Child maltreatment syndrome: demographics and developmental issues of inpatient cases.

    Science.gov (United States)

    Ngiam, Xin Ying; Kang, Ying Qi; Aishworiya, Ramkumar; Kiing, Jennifer; Law, Evelyn Chung Ning

    2015-11-01

    This study aimed to describe the demographic, social, developmental and behavioural profile of children hospitalised for alleged child maltreatment syndrome (CMS). This study was a retrospective review of the consecutive inpatient records of children (0-16 years) admitted to the National University Hospital, Singapore, for alleged CMS over a three-year period. Descriptive data on the demographic characteristics, alleged maltreatment, medical and developmental histories, and family background of these children were collected and analysed. Chi-square statistics were used to test whether family factors were associated with the type of maltreatment and the presence of developmental disorders. A total of 89 children, who accounted for 90 admission cases, were studied. Physical abuse (70.0%) was the most common, followed by neglect (11.1%) and sexual abuse (7.8%). Child protection services had already been involved in 29.2% of the cases prior to the child's admission. Children who were victims of abuse were more likely to come from homes with a prior history of domestic violence (p = 0.028). Financial difficulty was found to be a risk factor for neglect (p = 0.005). Among the 89 children, 15.7% were found to have developmental disorders and 10.1% had mental health diagnoses. Children who had developmental disorders were more likely to have a parent with a mental health disorder (p = 0.002). A sizeable proportion of the children admitted for alleged CMS had developmental or behavioural disorders. Clinicians have a role in ensuring that these children have appropriate follow-up plans. Children from high-risk families should be screened for maltreatment.

  20. Environmental versus demographic variability in stochastic predator–prey models

    International Nuclear Information System (INIS)

    Dobramysl, U; Täuber, U C

    2013-01-01

    In contrast to the neutral population cycles of the deterministic mean-field Lotka–Volterra rate equations, including spatial structure and stochastic noise in models for predator–prey interactions yields complex spatio-temporal structures associated with long-lived erratic population oscillations. Environmental variability in the form of quenched spatial randomness in the predation rates results in more localized activity patches. Our previous study showed that population fluctuations in rare favorable regions in turn cause a remarkable increase in the asymptotic densities of both predators and prey. Very intriguing features are found when variable interaction rates are affixed to individual particles rather than lattice sites. Stochastic dynamics with demographic variability in conjunction with inheritable predation efficiencies generate non-trivial time evolution for the predation rate distributions, yet with overall essentially neutral optimization. (paper)

  1. [The demographic development in Germany : challenge and chances for urology].

    Science.gov (United States)

    Schneider, A W; Fichtner, J

    2014-08-01

    Urology is affected by the demographic development in Germany more than any other medical discipline. Despite a relatively stable total population, by the year 2040 there will be an absolute and relevant increase in urological diseases caused only by the demographic development in the population. This is particularly true for the increase in oncological treatment just in the field of the discipline of urology. Even now the current numbers for tumor development in Germany (RKI 2014) in the urological oncology segment of all tumor diseases show an increasing trend with more than 23 %. This significant increase in performance is in contrast to the age development of the specialists in this discipline. In total but especially due to the significantly over-aged specialist medical profession in urology, this leads to a substantial bottleneck of specialists in the discipline of urology. This deficiency of personnel resources in urology is aggravated by the requirements of Generation Y for a well-adjusted work-life balance and the associated feminization of the medical profession. This requires intelligent strategies for.

  2. Demographic characteristics and employment among people with severe mental illness in a multisite study.

    Science.gov (United States)

    Burke-Miller, Jane K; Cook, Judith A; Grey, Dennis D; Razzano, Lisa A; Blyler, Crystal R; Leff, H Stephen; Gold, Paul B; Goldberg, Richard W; Mueser, Kim T; Cook, William L; Hoppe, Sue K; Stewart, Michelle; Blankertz, Laura; Dudek, Kenn; Taylor, Amanda L; Carey, Martha Ann

    2006-04-01

    People with psychiatric disabilities experience disproportionately high rates of unemployment. As research evidence is mounting regarding effective vocational programs, interest is growing in identifying subgroup variations. Data from a multisite research and demonstration program were analyzed to identify demographic characteristics associated with employment outcomes, after adjusting for the effects of program, services, and study site. Longitudinal analyses found that people with more recent work history, younger age, and higher education were more likely to achieve competitive employment and to work more hours per month, while race and gender effects varied by employment outcome. Results provide strong evidence of demographic subgroup variation and need.

  3. Public History

    Directory of Open Access Journals (Sweden)

    Marta Gouveia de Oliveira Rovai

    2017-04-01

    Full Text Available Este artigo tem como proposta apresentar o conceito e as práticas de História Pública como um novo posicionamento da ciência histórica em diálogo com profissionais da comunicação, no sentido de produzir e divulgar as experiências humanas. Para isso, discute-se a origem do conceito de História Pública e as diferentes formas de educação histórica que a utilização das novas tecnologias podem proporcionar (dentre elas a internet. Nesse sentido, convida-se o leitor para a reflexão sobre as possibilidades de publicização e de democratização do conhecimento histórico e da cultura, ampliando-se a oportunidade de produção, de divulgação e de acesso do público a diferentes formas experiências no tempo. O artigo também intenciona chamar atenção dos profissionais que lidam com a História e com a Comunicação para os perigos de produções exclusivamente submetidas ao mercado que transformam a popularização da História no reforço de estigmas culturais.   PALAVRAS-CHAVE: História Pública; Educação histórica e Comunicação; democratização e estigmatização.     ABSTRACT This article aims to present the concept and practices of Public History as a new positioning of historical science in dialogue with communication professionals, in the sense of producing and disseminating human experiences. For this, the origin of the concept of Public History and the different forms of historical education that the use of the new technologies can provide (among them the Internet is discussed. In this sense, the reader is invited to reflect on the possibilities of publicizing and democratizing historical knowledge and culture, expanding the opportunity for production, dissemination and public access to different forms of experience in time. The article also intends to draw attention from professionals dealing with History and Communication to the dangers of exclusively commercialized productions that transform the popularization

  4. Environmental vs Demographic Stochasticity in Population Growth

    OpenAIRE

    Braumann, C. A.

    2010-01-01

    Compares the effect on population growth of envinonmental stochasticity (random environmental variations described by stochastic differential equations) with demographic stochasticity (random variations in births and deaths described by branching processes and birth-and-death processes), in the density-independent and the density-dependent cases.

  5. The Demographics of Corporal Punishment in Texas

    Science.gov (United States)

    Phillips, Stephanie

    2012-01-01

    This dissertation examined the student discipline policies of 1,025 Texas school districts, as well as data from the Texas Education Agency's Academic Excellence Indicator System in order to identify demographic patterns regarding corporal punishment policies in Texas schools. The study also studied the relationship between a district's corporal…

  6. Psychological and Demographic Correlates of Career Patterns

    Science.gov (United States)

    Reitzle, Matthias; Korner, Astrid; Vondracek, Fred W.

    2009-01-01

    Recent years have witnessed a growing diversity of career patterns, resulting from the relative decline of stable employment. In the present study of 1368 employed and self-employed German adults career pattern diversity was assessed using nine pictograms. The goal was to identify psychological and demographic correlates of these patterns and to…

  7. Demographic development in ASEAN: a comparative overview.

    Science.gov (United States)

    Herrin, A N; Pardoko, H; Lim, L L; Hongladorom, C

    1981-01-01

    A comparative overview of recent demographic developments in the ASEAN (Association of Southeast Asian Nations) region is presented. Countries discussed include Indonesia, Malaysia, the Philippines, Singapore, and Thailand. Separate consideration is given to mortality; fertility; and migration, spatial distribution, and employment. A final section is concerned with emerging issues and directions for population policy.

  8. Global demographic change and climate policies

    NARCIS (Netherlands)

    Gerlagh, Reyer; Jaimes, Richard; Motavasseli, Ali

    2017-01-01

    Between 1950 and 2017, world average life expectancy increased from below-50 to above-70, while the fertility rate dropped from 5 to about 2.5. We develop and calibrate an analytic climate-economy model with overlapping generations to study the effect of such demographic change on capital markets

  9. Demographic Group Differences in Adolescents' Time Attitudes

    Science.gov (United States)

    Andretta, James R.; Worrell, Frank C.; Mello, Zena R.; Dixson, Dante D.; Baik, Sharon H.

    2013-01-01

    In the present study, we examined demographic differences in time attitudes in a sample of 293 adolescents. Time attitudes were measured using the Adolescent Time Attitude Scale (Mello & Worrell, 2007; Worrell, Mello, & Buhl, 2011), which assesses positive and negative attitudes toward the past, the present, and the future. Generally, African…

  10. Changing demographics and shrinking engineering enrollments

    International Nuclear Information System (INIS)

    Vetter, B.M.

    1992-01-01

    This paper reports that changing U.S. population demographics, poor academic preparation, and a decreasing interest in engineering among college student indicate possible shortages ahead, particularly among chemical and petroleum engineers. If we are to ensure an adequate future supply for the U.S., the engineering talent pool must be enlarged to include women and minority men

  11. Demographic and Socioeconomic Factors Influencing Malaria

    African Journals Online (AJOL)

    Gyuk et al.

    demographic environment also plays a significant role in the ... Also, Child mortality rates are known to be higher in poor .... especially Christian women have better health education than ... urban life which could have some impacts on malaria prevention .... insecticides, leave in decent areas and are able to access medical ...

  12. Understanding the Demographic and Health Transition in ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    The shift from high to low levels of mortality and fertility called the demographic transition occurred over a century ago in the developed world. While the reasons for the transition in Western Europe and North America are well documented, little is known about the transition in developing countries except that it is reported to ...

  13. Demographic characteristics of nuclear installations sites

    International Nuclear Information System (INIS)

    Doumenc, A.; Faure, J.

    1988-01-01

    The selection of a nuclear installations sites can not be conceived without a deep analysis of demographic context. This analysis permits to define the critical populations around the installation and is an essential element of emergency plans. 1 tab., 2 refs. (F.M.)

  14. The demographic situation in the European Union

    NARCIS (Netherlands)

    van Nimwegen, N.; van der Erf, R.F.; Heering, E.L.; van Nimwegen, N.; van der Erf, R.

    2009-01-01

    This chapter focuses on the recent demographic situation and related population trends in the 27 Member States of the European Union. Some attention will also be paid to its two Candidate Countries, Croatia and the Former Yugoslav Republic of Macedonia, as well as to the EFTA Countries (Iceland,

  15. demographic factors associated factors associated with malaria

    African Journals Online (AJOL)

    userpc

    .8%) than those in other nce of 35.4% which was actors can predispose alence of malaria in a study were significantly eveloping guidelines and more effective disease endemic areas (Bashar et therefore attempts to rmation on possible demographic factors d out in four selected geria; Major Ibrahim B. Hospital Zaria, Hajiya.

  16. Demographic change in the northern forest

    Science.gov (United States)

    Kenneth M. Johnson; Susan I. Stewart; Miranda H. Mockrin

    2012-01-01

    The Northern Forest spans more than 26 million acres across Maine, New Hampshire, New York, and Vermont. With densely settled urban cores, sprawling suburbs, struggling industrial and forest products towns, fast growing recreational areas, and isolated rural villages, the region includes many of the diverse strands that together compose the demographic fabric of the...

  17. Demographic monitoring of Wright fishhook cactus

    Science.gov (United States)

    Ronald J. Kass

    2001-01-01

    Wright fishhook cactus (Sclerocactus wrightiae Benson) is a small barrel cactus endemic to the San Rafael Swell in south-central Utah. It was listed as an endangered species in 1979 due to its small population size, threats of over-collecting, and development associated with oil and gas. Demographic monitoring was initiated in 1993 with the following objectives: to...

  18. Clinico - demographic factors associated with diarrhoeal disease ...

    African Journals Online (AJOL)

    Objectives: To determine the proportion of under-5 children presenting with diarrhoeal disease, and the clinicodemographic variables associated with the outcome at the emergency paediatric ward (CHER) of the Nnamdi Azikiwe University Teaching Hospital, Nnewi, South- East Nigeria. Methods: Clinical and demographic ...

  19. Demographic profile of patients diagnosed with intracranial ...

    African Journals Online (AJOL)

    Abstract. Background: Meningiomas are common brain tumours and display gender, racial and ethnic differences in their demographic profile. ... The mean age of patients was 45.7 ± 10.5 years with a female-to-male ratio of 3.8:1. The mean ...

  20. Demographic characteristics, leadership styles, job attitudes and ...

    African Journals Online (AJOL)

    This purpose of this study was to investigate the predictive influence of demographic characteristics, leadership styles, job attitudes and personality on job performance among civil servants in Southwest Nigeria. The sample consists of 400 civil servants (males = 275, females = 125) randomly selected from Southwestern ...

  1. The Value of Contrast Echocardiography

    Directory of Open Access Journals (Sweden)

    Shannon C. Treiber

    2016-01-01

    Full Text Available Purpose: There is much evidence-based research proving the effectiveness of contrast echocardiography, but there are still questions and concerns about its specific uses. This study tested the effectiveness of contrast echocardiography in defining the left ventricular endocardial border. Methods: From 30 patients, a total of 60 echocardiograms –– 30 with and 30 without use of contrast –– were retrospectively reviewed by four blinded cardiologists with advanced training in echocardiography. No single cardiologist reviewed contrast and noncontrast images of the same patient. Each set of 30 echocardiograms was then studied for wall-motion scoring. Visualization of left ventricular wall segments and a global visualization confidence level of interpretation were recorded. Results: Of all wall segments (N = 510, 91% were visualized in echocardiograms with use of contrast, whereas 75% of the walls were visualized in echocardiograms without contrast (P < 0.001. Of 30 examinations, 17 contrast echocardiograms were read with high confidence compared to 6 without contrast use (P = 0.004. The number of walls visualized with contrast was increased in 18 patients (60%, whereas noncontrast echocardiograms yielded more visualized walls in 6 patients (20%, P = 0.002. Conclusions: This study demonstrates that contrast is valuable to echocardiographic imaging. Its use should be supported throughout echocardiography clinics and encouraged in certain patients for whom resting and stress echocardiography results without contrast often prove uninterpretable.

  2. The demographic transition influences variance in fitness and selection on height and BMI in rural Gambia.

    Science.gov (United States)

    Courtiol, Alexandre; Rickard, Ian J; Lummaa, Virpi; Prentice, Andrew M; Fulford, Anthony J C; Stearns, Stephen C

    2013-05-20

    Recent human history is marked by demographic transitions characterized by declines in mortality and fertility. By influencing the variance in those fitness components, demographic transitions can affect selection on other traits. Parallel to changes in selection triggered by demography per se, relationships between fitness and anthropometric traits are also expected to change due to modification of the environment. Here we explore for the first time these two main evolutionary consequences of demographic transitions using a unique data set containing survival, fertility, and anthropometric data for thousands of women in rural Gambia from 1956-2010. We show how the demographic transition influenced directional selection on height and body mass index (BMI). We observed a change in selection for both traits mediated by variation in fertility: selection initially favored short females with high BMI values but shifted across the demographic transition to favor tall females with low BMI values. We demonstrate that these differences resulted both from changes in fitness variance that shape the strength of selection and from shifts in selective pressures triggered by environmental changes. These results suggest that demographic and environmental trends encountered by current human populations worldwide are likely to modify, but not stop, natural selection in humans. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Effects of computed tomography contrast medium factors on contrast enhancement

    International Nuclear Information System (INIS)

    Terasawa, Kazuaki; Hatcho, Atsushi; Okuda, Itsuko

    2011-01-01

    The various nonionic iodinated contrast media used in contrast computed tomography (CT) studies differ in terms of their composition, characteristics, and iodine concentration (mgI/ml), as well as the volume injected (ml). Compared with ionic iodinated contrast media, nonionic iodinated contrast media are low-osmolar agents, with different agents having different osmotic pressures. Using a custom-made phantom incorporating a semipermeable membrane, the osmotic flow rate (hounsfield unit (HU)/s) could easily be measured based on the observed increase in CT numbers, and the relationship between the osmotic pressure and the osmotic flow rate could be obtained (r 2 =0.84). In addition, taking the effects of patient size into consideration, the levels of contrast enhancement in the abdominal aorta (AA) and inferior vena cava (IVC) were compared among four types of CT contrast medium. The results showed differences in contrast enhancement in the IVC during the equilibrium phase depending on the type of contrast medium used. It was found that the factors responsible for the differences observed in enhancement in the IVC were the osmotic flow rate and the volume of the blood flow pathways in the circulatory system. It is therefore considered that the reproducibility of contrast enhancement is likely to be reduced in the examination of parenchymal organs, in which scanning must be performed during the equilibrium phase, even if the amount of iodine injected per unit body weight (mgI/kg) is maintained at a specified level. (author)

  4. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

    Tuljapurkar, Shripad; Steiner, Uli; Orzack, Steven Hecht

    2009-01-01

    or no fixed heterogeneity influences this trait. We propose that dynamic heterogeneity provides a 'neutral' model for assessing the possible role of unobserved 'quality' differences between individuals. We discuss fitness for dynamic life histories, and the implications of dynamic heterogeneity...... generate dynamic heterogeneity: life-history differences produced by stochastic stratum dynamics. We characterize dynamic heterogeneity in a range of species across taxa by properties of the Markov chain: the entropy, which describes the extent of heterogeneity, and the subdominant eigenvalue, which...... distributions of lifetime reproductive success. Dynamic heterogeneity contrasts with fixed heterogeneity: unobserved differences that generate variation between life histories. We show by an example that observed distributions of lifetime reproductive success are often consistent with the claim that little...

  5. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncica, Ana Maria; Saftoiu, Adrian

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...

  6. Demographic variables in coal miners’ safety attitude

    Science.gov (United States)

    Yin, Wen-wen; Wu, Xiang; Ci, Hui-Peng; Qin, Shu-Qi; Liu, Jia-Long

    2017-03-01

    To change unsafe behavior through adjusting people’s safety attitudes has become an important measure to prevent accidents. Demographic variables, as influential factors of safety attitude, are fundamental and essential for the research. This research does a questionnaire survey among coal mine industry workers, and makes variance analysis and correlation analysis of the results in light of age, length of working years, educational level and experiences of accidents. The results show that the coal miners’ age, length of working years and accident experiences correlate lowly with safety attitudes, and those older coal miners with longer working years have better safety attitude, as coal miners without experiences of accident do.However, educational level has nothing to do with the safety attitude. Therefore, during the process of safety management, coal miners with different demographic characteristics should be put more attention to.

  7. Simulation of Demographic Change in Palestinian Territories

    Science.gov (United States)

    Sumour, M. A.; El-Astal, A. H.; Shabat, M. M.; Radwan, M. A.

    Mortality, birth rates and retirement play a major role in demographic changes. In most cases, mortality rates decreased in the past century without noticeable decrease in fertility rates, leading to a significant increase in population growth. In many poor countries like Palestinian Territories the number of births has fallen and the life expectancy increased. In this paper we concentrate on measuring, analyzing and extrapolating the age structure in Palestine a few decades ago into the future. A Fortran program has been designed and used for the simulation and analysis of our statistical data. This study of demographic change in Palestine has shown that Palestinians will have in future problems as the strongest age cohorts are the above-60-year olds. We therefore recommend the increase of both the retirement age and female employment.

  8. Complexity and demographic explanations of cumulative culture.

    Science.gov (United States)

    Querbes, Adrien; Vaesen, Krist; Houkes, Wybo

    2014-01-01

    Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century) to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

  9. Complexity and demographic explanations of cumulative culture.

    Directory of Open Access Journals (Sweden)

    Adrien Querbes

    Full Text Available Formal models have linked prehistoric and historical instances of technological change (e.g., the Upper Paleolithic transition, cultural loss in Holocene Tasmania, scientific progress since the late nineteenth century to demographic change. According to these models, cumulation of technological complexity is inhibited by decreasing--while favoured by increasing--population levels. Here we show that these findings are contingent on how complexity is defined: demography plays a much more limited role in sustaining cumulative culture in case formal models deploy Herbert Simon's definition of complexity rather than the particular definitions of complexity hitherto assumed. Given that currently available empirical evidence doesn't afford discriminating proper from improper definitions of complexity, our robustness analyses put into question the force of recent demographic explanations of particular episodes of cultural change.

  10. Is the demographic dividend an education dividend?

    Science.gov (United States)

    Crespo Cuaresma, Jesús; Lutz, Wolfgang; Sanderson, Warren

    2014-02-01

    The effect of changes in age structure on economic growth has been widely studied in the demography and population economics literature. The beneficial effect of changes in age structure after a decrease in fertility has become known as the "demographic dividend." In this article, we reassess the empirical evidence on the associations among economic growth, changes in age structure, labor force participation, and educational attainment. Using a global panel of countries, we find that after the effect of human capital dynamics is controlled for, no evidence exists that changes in age structure affect labor productivity. Our results imply that improvements in educational attainment are the key to explaining productivity and income growth and that a substantial portion of the demographic dividend is an education dividend.

  11. Running injuries - changing trends and demographics.

    Science.gov (United States)

    Fields, Karl B

    2011-01-01

    Running injuries are common. Recently the demographic has changed, in that most runners in road races are older and injuries now include those more common in master runners. In particular, Achilles/calf injuries, iliotibial band injury, meniscus injury, and muscle injuries to the hamstrings and quadriceps represent higher percentages of the overall injury mix in recent epidemiologic studies compared with earlier ones. Evidence suggests that running mileage and previous injury are important predictors of running injury. Evidence-based research now helps guide the treatment of iliotibial band, patellofemoral syndrome, and Achilles tendinopathy. The use of topical nitroglycerin in tendinopathy and orthotics for the treatment of patellofemoral syndrome has moderate to strong evidence. Thus, more current knowledge about the changing demographics of runners and the application of research to guide treatment and, eventually, prevent running injury offers hope that clinicians can help reduce the high morbidity associated with long-distance running.

  12. Properties of conventional contrast media

    International Nuclear Information System (INIS)

    Muetzel, W.

    1981-01-01

    A comprehensive overview is given of the properties of contrast media currently used in computed tomography (CT). The chemical structure of the compounds and the physicochemical properties derived therefrom are described. Emphasis is placed on the importance of the physicochemical properties of contrast media for tolerance and the pharmacokinetic behavior of compounds in the body. An outline is given of the basic ideas governing rational use of contrast media in CT, which result from complex, time-dependent distribution of contrast media in different tissue spaces. (Auth.)

  13. Using Twitter data for demographic research

    Directory of Open Access Journals (Sweden)

    Dilek Yildiz

    2017-11-01

    Full Text Available Background: Social media data is a promising source of social science data. However, deriving the demographic characteristics of users and dealing with the nonrandom, nonrepresentative populations from which they are drawn represent challenges for social scientists. Objective: Given the growing use of social media data in social science research, this paper asks two questions: 1 To what extent are findings obtained with social media data generalizable to broader populations, and 2 what is the best practice for estimating demographic information from Twitter data? Methods: Our analyses use information gathered from 979,992 geo-located Tweets sent by 22,356 unique users in South East England between 23 June and 4 July 2014. We estimate demographic characteristics of the Twitter users with the crowd-sourcing platform CrowdFlower and the image-recognition software Face++. To evaluate bias in the data, we run a series of log-linear models with offsets and calibrate the nonrepresentative sample of Twitter users with mid-year population estimates for South East England. Results: CrowdFlower proves to be more accurate than Face++ for the measurement of age, whereas both tools are highly reliable for measuring the sex of Twitter users. The calibration exercise allows bias correction in the age-, sex-, and location-specific population counts obtained from the Twitter population by augmenting Twitter data with mid-year population estimates. Contribution: The paper proposes best practices for estimating Twitter users' basic demographic characteristics and a calibration method to address the selection bias in the Twitter population, allowing researchers to generalize findings based on Twitter to the general population.

  14. [Demographic characteristics of consumers in Indonesia?].

    Science.gov (United States)

    Ananta, A

    1993-06-01

    "This paper presents a mosaic of business opportunities arising from the different demographic characteristics of the provinces in the western part of Indonesia. The author discusses the total number of population, density, and per capita income to [shed] some light on the volume of the market. He also presents the business impact of the [changes] in fertility, mortality, and the...life style of those aged 40-64." (SUMMARY IN ENG) excerpt

  15. Demographic and economic disparities among Arctic regions

    OpenAIRE

    Schmidt, Jennifer Irene; Aanesen, Margrethe; Klokov, Konstantin; Kruschov, Sergei; Hausner, Vera Helene

    2015-01-01

    Accepted manuscript version. Published version at http://doi.org/10.1080/1088937X.2015.1065926. We use demographic and economic indicators to analyze spatial differences and temporal trends across 18 regions surrounding the Arctic Ocean. Multifactor and cluster analysis were used on 10 indicators reflecting income, employment and demography from 1995 to 2008. The main difference is between regions with high population densities, low natural growth rate, and low unemployment (Ru...

  16. Demographic Modeling Via 3-dimensional Markov Chains

    OpenAIRE

    Viquez, Juan Jose; Campos, Alexander; Loria, Jorge; Mendoza, Luis Alfredo; Viquez, Jorge Aurelio

    2017-01-01

    This article presents a new model for demographic simulation which can be used to forecast and estimate the number of people in pension funds (contributors and retirees) as well as workers in a public institution. Furthermore, the model introduces opportunities to quantify the financial ows coming from future populations such as salaries, contributions, salary supplements, employer contribution to savings/pensions, among others. The implementation of this probabilistic model will be of great ...

  17. DEMOGRAPHIC PROFILE OF ADVENTURE TOURISTS IN PRETORIA

    OpenAIRE

    Melissa Jeanette Lötter; Sue Geldenhuys; Marius Potgieter

    2012-01-01

    It is difficult to examine different motivations and segment differentiations in niche markets such as adventure tourism seeing that it is not a well-defined segment in the discipline of tourism studies. In order to assist adventure tourism companies towards identifying and developing effective marketing strategies to attract or penetrate the adventure niche market, this study aims to contribute towards the current understanding of adventure tourists in Pretoria by compiling a demographic pro...

  18. Demographic and transportation parameters in RADTRAN

    International Nuclear Information System (INIS)

    Brogan, J.D.; Cashwell, J.W.; Neuhauser, K.S.

    1989-01-01

    Recent efforts at Sandia National Laboratories have focused not only on modification of the RADTRAN transportation risk analysis code but also on updating the default parameters for population, land use, and roadway characteristics used by the code. Changes to the code have been discussed earlier in this Conference. This paper summarizes the results of a review of transportation and demographic parameters, performed to complement recent model modifications

  19. Responsive survey design, demographic data collection, and models of demographic behavior.

    Science.gov (United States)

    Axinn, William G; Link, Cynthia F; Groves, Robert M

    2011-08-01

    To address declining response rates and rising data-collection costs, survey methodologists have devised new techniques for using process data ("paradata") to address nonresponse by altering the survey design dynamically during data collection. We investigate the substantive consequences of responsive survey design-tools that use paradata to improve the representative qualities of surveys and control costs. By improving representation of reluctant respondents, responsive design can change our understanding of the topic being studied. Using the National Survey of Family Growth Cycle 6, we illustrate how responsive survey design can shape both demographic estimates and models of demographic behaviors based on survey data. By juxtaposing measures from regular and responsive data collection phases, we document how special efforts to interview reluctant respondents may affect demographic estimates. Results demonstrate the potential of responsive survey design to change the quality of demographic research based on survey data.

  20. Exile and demographic population growth in Serbia

    Directory of Open Access Journals (Sweden)

    Stevanović Radoslav

    2005-01-01

    Full Text Available The data of the 2002 population census on refugee population are analyzed in this paper with a basic aim to determine the significance (contribution of refugee corpus in demographic development of the Republic of Serbia. By analyzing the data, it has been determined that the refugee corpus does not significantly differ from the domicile population in the basic, above all demographic and other qualitative characteristics. The differences which can be noticed with certain (primarily socio-economic characteristics, due to the proportionally small participation of refugee persons in relation to the total (domicile population, could not significantly influence the total demographic, socio-economic and other characteristics of the population of central Serbia and Vojvodina. The most significant contribution of refugee (classifying the refugee corpus in the country's total population is reflected in the mitigation of the depopulation trend, namely population growth, not only both micro-entities, but also lower administrative-territorial entities (districts depending on the enumerated refugee population in them. However, population projections indicate that by the middle of this century (2050 the positive effects of the basically larger number of inhabitants will be lost caused by the inflow of refugee population.

  1. Intelligent system to study demographic evolution

    Science.gov (United States)

    Rodrigues, M. de Fatima; Ramos, Carlos; Henriques, Pedro R.

    1999-02-01

    With three centuries of existence, the study of population's behavior implies the manipulation of large amounts of incomplete and imprecise data with high dimensionality. By virtue of its multidisciplinary character, the work in demography involves at least historicists, statisticians and computer scientists/programmers. Moreover, successful demographic analysis requires qualified experts, who have succeeded in analysing data through many views and relate different sources of information, including their personal knowledge of the epoch or regions under study. In this paper, we present an intelligent system to study demographic evolution (ISSDE). This system has a module based on on-line analytical processing (OLAP), which permits conducting multiple analysis, combining many data dimensions. It has a deductive database system, which allows the execution of elaborated queries through the database. It has another module for date treatment (generalization and/or reduction); and, at last, a data mining module to discover nontrivial relations hidden within data. We discover the data treatment procedure with two phases: data generalization and data reduction. In data generalization, utilizing knowledge about concept hierarchies and relevance of data, aggregation of attribute values is performed. In the data reduction phase, rough set theory is applied to compute the minimal attribute set. We highlight the advantages of combining attribute value generalization with rough set theory, to find a subset of attributes that lets the mining process discover more useful patterns, by providing results from the application of the C5.0 algorithm in a demographic relational database.

  2. Beyond demographics is destiny: understanding economic mitigation strategies for demographic change in China

    OpenAIRE

    Judy, John B.

    2015-01-01

    Approved for public release; distribution is unlimited The favorable demographics that have contributed to China’s rapid economic growth are changing. China’s working-age population is currently peaking and within two decades its overall population will begin to shrink. In addition to a shrinking working-age population, China will see an increase in the elderly population and a rising dependency ratio. This demographic change may have an economically significant impact. If China’s enormous...

  3. CORRELATIONS BETWEEN AWARENESS OF ILLNESS (INSIGHT AND HISTORY OF ADDICTION IN HEROIN-ADDICTED PATIENTS

    Directory of Open Access Journals (Sweden)

    Angelo Giovanni Icro eMaremmani

    2012-07-01

    Full Text Available In a group of 1066 heroin addicts, who were seeking treatment for opioid agonist treatment, we looked for differences in historical, demographic and clinical characteristics, between patients with different levels of awareness of illness (insight. The results showed that, in the cohort studied, a majority of subjects lacked insight into their heroin-use behaviour. Compared with the impaired-insight group, those who possessed insight into their illness showed significantly greater awareness of past social, somatic and psychopathological impairments, and had a greater number of past treatment-seeking events for heroin addiction. In contrast with other psychiatric illnesses, the presence of awareness appears to be related to the passing of time and to the worsening of the illness. Methodologies to improve the insight of patients should, therefore, be targeted more directly on patients early in their history of heroin dependence, because the risk of lack of insight is greatest during this period.

  4. Decline, Adaptation or Transformation:New Perspectives on Demographic Change in Resource Peripheries in Australia and Sweden

    Directory of Open Access Journals (Sweden)

    Dean B. Carson

    2016-01-01

    Full Text Available Many sparsely populated resource peripheries in developed countries are perceived to suffer from periods of demographic decline due to loss of employment opportunities and services, youth out-migration and population ageing. While these trends tend to apply at broad regional scales and for particular time periods, diverse patterns of demographic change may be apparent if different spatial, temporal and social scales of analysis are taken into consideration. Comparing the experiences of two case study regions in northern Sweden and inland South Australia, this paper proposes an alternative conceptual framework to the “discourse of decline”, which could be used to examine the nuances of demographic change within resource peripheries. The framework includes spatial scale considerations that contrast broader regional demographic patterns with the experiences of sub-regions and individual settlements. It also includes temporal scale aspects, examining demographic change over different time periods to understand the pace, duration and frequency of population growth and decline. The framework finally includes social unit considerations, emphasising that demographic change affects different social groups in different ways. The results of the case studies suggest that considering demographic change as adaptation or transformation rather than decline may be more useful for identifying new – and qualitatively different – demographic pathways that emerge over time.

  5. Celebrate Women's History.

    Science.gov (United States)

    Leonard, Carolyn M.; Baradar, Mariam

    This teachers' guide to activities celebrating Women's History Month focuses on women whose important contributions have been omitted from history textbooks. Women's History Month grew from a 1977 celebration of Women's History Week and is intended to bring women's history into the school curriculum. International Women's Day, celebrated on March…

  6. Demographics and frequency of the intermittently upturned omentum at CT

    Energy Technology Data Exchange (ETDEWEB)

    Penn, Alex; Wang, Wilbur; Wang, Zhen Jane; Yee, Judy; Webb, Emily M.; Yeh, Benjamin M., E-mail: ben.yeh@ucsf.edu

    2013-11-01

    Objectives: To describe the demographics and frequency of the intermittently upturned omentum at CT. Methods: We retrospectively reviewed abdominal CT scans of 336 consecutive patients (189 men and 147 women) who were imaged between June 1 and June 17, 2010 and who had prior comparison scans. Readers recorded the presence or absence of an intermittently upturned omentum, defined as a thick rind of fat interposed between the liver and the anterior abdominal wall seen on one but not the other scan. At chart review, we recorded patient demographics and other clinical characteristics (prior surgical history, presence of cirrhosis). Results: An intermittently upturned omentum was found in 10 of 336 (3.0%) patients. An intermittently upturned omentum was seen more commonly in men than in women (9 of 189 men, or 4.8% versus 1 of 147 women, or 0.7%, p = 0.047) and in cirrhotics (4 of 37 cirrhotics, or 10.8% versus 6 of 299 non-cirrhotics, or 2.0%, p = 0.023). In a sub-analysis of patients without prior abdominal surgery, this finding was again seen more commonly in men than women (7 of 163 men, or 4.3% versus 0 of 134 women, or 0%, p = 0.018) and in cirrhotics (3 of 33 cirrhotics, or 9.1% versus 4 of 264 non-cirrhotics, or 1.5%, p = 0.032). Conclusions: An intermittently upturned omentum is not uncommon and is more frequently seen in men and in patients with cirrhosis who may have a larger anterior hepatic space.

  7. Demographics and frequency of the intermittently upturned omentum at CT

    International Nuclear Information System (INIS)

    Penn, Alex; Wang, Wilbur; Wang, Zhen Jane; Yee, Judy; Webb, Emily M.; Yeh, Benjamin M.

    2013-01-01

    Objectives: To describe the demographics and frequency of the intermittently upturned omentum at CT. Methods: We retrospectively reviewed abdominal CT scans of 336 consecutive patients (189 men and 147 women) who were imaged between June 1 and June 17, 2010 and who had prior comparison scans. Readers recorded the presence or absence of an intermittently upturned omentum, defined as a thick rind of fat interposed between the liver and the anterior abdominal wall seen on one but not the other scan. At chart review, we recorded patient demographics and other clinical characteristics (prior surgical history, presence of cirrhosis). Results: An intermittently upturned omentum was found in 10 of 336 (3.0%) patients. An intermittently upturned omentum was seen more commonly in men than in women (9 of 189 men, or 4.8% versus 1 of 147 women, or 0.7%, p = 0.047) and in cirrhotics (4 of 37 cirrhotics, or 10.8% versus 6 of 299 non-cirrhotics, or 2.0%, p = 0.023). In a sub-analysis of patients without prior abdominal surgery, this finding was again seen more commonly in men than women (7 of 163 men, or 4.3% versus 0 of 134 women, or 0%, p = 0.018) and in cirrhotics (3 of 33 cirrhotics, or 9.1% versus 4 of 264 non-cirrhotics, or 1.5%, p = 0.032). Conclusions: An intermittently upturned omentum is not uncommon and is more frequently seen in men and in patients with cirrhosis who may have a larger anterior hepatic space

  8. The new numbers contrast sensitivity chart for contrast sensitivity measurement

    Directory of Open Access Journals (Sweden)

    Bharkbhum Khambhiphant

    2011-10-01

    Conclusions: These charts show reasonable agreement and can be used interchangeably with the MARS. It is helpful for Thai people who can only read numbers in doing the test. We can use them in routinely contrast sensitivity measurement.

  9. Sensitivity analysis of effective population size to demographic parameters in house sparrow populations.

    Science.gov (United States)

    Stubberud, Marlene Waege; Myhre, Ane Marlene; Holand, Håkon; Kvalnes, Thomas; Ringsby, Thor Harald; Saether, Bernt-Erik; Jensen, Henrik

    2017-05-01

    The ratio between the effective and the census population size, Ne/N, is an important measure of the long-term viability and sustainability of a population. Understanding which demographic processes that affect Ne/N most will improve our understanding of how genetic drift and the probability of fixation of alleles is affected by demography. This knowledge may also be of vital importance in management of endangered populations and species. Here, we use data from 13 natural populations of house sparrow (Passer domesticus) in Norway to calculate the demographic parameters that determine Ne/N. Using the global variance-based Sobol' method for the sensitivity analyses, we found that Ne/N was most sensitive to demographic variance, especially among older individuals. Furthermore, the individual reproductive values (that determine the demographic variance) were most sensitive to variation in fecundity. Our results draw attention to the applicability of sensitivity analyses in population management and conservation. For population management aiming to reduce the loss of genetic variation, a sensitivity analysis may indicate the demographic parameters towards which resources should be focused. The result of such an analysis may depend on the life history and mating system of the population or species under consideration, because the vital rates and sex-age classes that Ne/N is most sensitive to may change accordingly. © 2017 John Wiley & Sons Ltd.

  10. Accuracy of Demographic Inferences from the Site Frequency Spectrum: The Case of the Yoruba Population.

    Science.gov (United States)

    Lapierre, Marguerite; Lambert, Amaury; Achaz, Guillaume

    2017-05-01

    Some methods for demographic inference based on the observed genetic diversity of current populations rely on the use of summary statistics such as the Site Frequency Spectrum (SFS). Demographic models can be either model-constrained with numerous parameters, such as growth rates, timing of demographic events, and migration rates, or model-flexible, with an unbounded collection of piecewise constant sizes. It is still debated whether demographic histories can be accurately inferred based on the SFS. Here, we illustrate this theoretical issue on an example of demographic inference for an African population. The SFS of the Yoruba population (data from the 1000 Genomes Project) is fit to a simple model of population growth described with a single parameter ( e.g. , founding time). We infer a time to the most recent common ancestor of 1.7 million years (MY) for this population. However, we show that the Yoruba SFS is not informative enough to discriminate between several different models of growth. We also show that for such simple demographies, the fit of one-parameter models outperforms the stairway plot, a recently developed model-flexible method. The use of this method on simulated data suggests that it is biased by the noise intrinsically present in the data. Copyright © 2017 by the Genetics Society of America.

  11. Contrast-enhanced peripheral MRA. Technique and contrast agents

    International Nuclear Information System (INIS)

    Nielsen, Yousef W.; Thomsen, Henrik S.

    2012-01-01

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast agents. Peripheral CE-MRA is defined as an MR angiogram of the arteries from the aortic bifurcation to the feet. Advantages of CE-MRA include minimal invasiveness and lack of ionizing radiation. The basic technique employed for peripheral CE-MRA is the bolus-chase method. With this method a paramagnetic MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic field strength of the MRI system, receiver coil configuration, use of parallel imaging, contrast bolus timing technique, and k-space filling strategies. Furthermore, it is possible to optimize peripheral CE-MRA using venous compression techniques, hybrid scan protocols, time-resolved imaging, and steady-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal insufficiency. Using optimized technique and a stable MRI contrast agent, peripheral CE-MRA is a safe procedure with diagnostic accuracy close to that of conventional catheter X

  12. Adriamycin nephrosis and contrast media

    International Nuclear Information System (INIS)

    Thomsen, H.S.; Golman, K.; Hemmingsen, L.; Larsen, S.; Skaarup, P.; Koebenhavns Amts Sygehus, Herlev; Koebenhavns Amts Sygehus, Herlev; Centralsygehuset, Nykoebing Falster; Malmoe Allmaenna Sjukhus

    1990-01-01

    Urine profiles (albumin, glucose, NAG, LDH, GGT and sodium) were followed for 9 days after intravenous injection of either diatrizoate, iohexol, or saline in 27 Wistar rats with nephrosis induced by Adriamycin 42 days before. Another 9 rats exposed to neither Adriamycin nor contrast media served as controls. None of the contrast media caused further increased albuminuria of significance, whereas both induced significantly increased excretion of all 5 tubular components. The excretion of NAG and sodium was significantly higher following diatrizoate than following iohexol. From 24 h post injection there was no significantly greater excretion of any of the components after either diatrizoate or iohexol than after saline among the rats given Adriamycin. At the end of day 9 after contrast medium injection neither serum sodium, potassium, glucose, urea, creatinine, nor albumin revealed any contrast media related changes. Kidney histology showed quantitatively larger lesions in kidneys exposed to Adriamycin and contrast media than in kidneys exposed to Adriamycin and saline. There were no differences between the two contrast media groups. It is thus concluded, that both high osmolar ionic and low osmolar non-ionic contrast media cause temporary tubular dysfunction but no further glomerular dysfunction in rats with nephrosis induced by Adriamycin. The histologic findings indicate that both media may worsen non-reversible renal lesions. (orig.)

  13. Stock vs. Bond Yields, and Demographic Fluctuations

    DEFF Research Database (Denmark)

    Gozluklu, Arie; Morin, Annaïg

    This paper analyzes the strong comovement between real stock and nominal bond yields at generational (low) frequencies. Life-cycle patterns in savings behavior in an overlapping generations model with cash-in-advance constraints explain this persistent comovement between financial yields. We argue...... that the slow-evolving time-series covariation due to changing population age structure accounts for the equilibrium relation between stock and bond markets. As a result, by exploiting the demographic information into distant future, the forecasting performance of evaluation models improves. Finally, using...

  14. Environment, migration and the European demographic deficit

    International Nuclear Information System (INIS)

    Harper, Sarah

    2012-01-01

    Many countries in the more developed world, and some in the less developed, are facing new economic and social pressures associated with the ageing of their populations. Europe, in particular, is forecast to have a demographic deficit, which may be alleviated by in-migration to the region. However, several commentators have proposed that Europe will not be able to successfully compete with other regions, in particular Asia, in the coming years for the skills it will require. This letter explores these themes, arguing that climate change will increase the attractiveness of Europe as a destination of economic choice for future skilled workers, to the detriment of more environmentally challenged regions. (letter)

  15. Environment, migration and the European demographic deficit

    Science.gov (United States)

    Harper, Sarah

    2012-03-01

    Many countries in the more developed world, and some in the less developed, are facing new economic and social pressures associated with the ageing of their populations. Europe, in particular, is forecast to have a demographic deficit, which may be alleviated by in-migration to the region. However, several commentators have proposed that Europe will not be able to successfully compete with other regions, in particular Asia, in the coming years for the skills it will require. This letter explores these themes, arguing that climate change will increase the attractiveness of Europe as a destination of economic choice for future skilled workers, to the detriment of more environmentally challenged regions.

  16. [Demographic development of Croatia, 1991-1994].

    Science.gov (United States)

    Lajic, I

    1995-01-01

    "The demographic development of Croatia in the period 1991-1994, marked by... Serbian aggression, the state of ¿half-war', and the war in Bosnia and Hercegovina, should be described as irregular--its components being determined by the above conditions. This proves especially true concerning forced migrations and their past and future influence on population change. The paper analyzes the insufficiently studied topic of war mortality, as well as various dimensions of the refugee population. It also emphasizes several structural characteristics of the population, particularly its ethnic structure, and the population dynamics in the temporarily occupied territories." (EXCERPT)

  17. Patterns of demographic change in the Americas.

    Science.gov (United States)

    Ubelaker, D H

    1992-06-01

    Considerable scholarly debate has focused on the nature of demographic change in the Americas before and after 1492. Recent research on human skeletal samples and related archeological materials suggests that morbidity and mortality were increasing throughout much of the Western Hemisphere before 1492 in response to increased population density, increased sedentism, and changing subsistence. The evidence suggests that after 1492 population reduction was caused not by continental pandemics but by localized or regional epidemics augmented by social and economic disruption. The twentieth century has witnessed remarkable Native American population recovery, fueled both by improvements in health care and changing definitions of "being Indian."

  18. Enforcement and Compliance History Online | US EPA

    Science.gov (United States)

    ECHO, Enforcement and Compliance History Online, provides compliance and enforcement information for approximately 800,000 EPA-regulated facilities nationwide. ECHO includes permit, inspection, violation, enforcement action, and penalty information about facilities regulated under the Clean Air Act (CAA) Stationary Source Program, Clean Water Act (CWA) National Pollutant Elimination Discharge System (NPDES), and/or Resource Conservation and Recovery Act (RCRA). Information also is provided on surrounding demographics when available.

  19. The AAVSO 2011 Demographic and Background Survey

    Science.gov (United States)

    Price, A.

    2012-04-01

    In 2011, the AAVSO conducted a survey of 615 people who are or were recently active in the organization. The survey included questions about their demographic background and variable star interests. Data are descriptively analyzed and compared with prior surveys. Results show an organization of very highly educated, largely male amateur and professional astronomers distributed across 108 countries. Participants tend to be loyal, with the average time of involvement in the AAVSO reported as 14 years. Most major demographic factors have not changed much over time. However, the average age of new members is increasing. Also, a significant portion of the respondents report being strictly active in a non-observing capacity, reflecting the growing mission of the organization. Motivations of participants are more aligned with scientific contribution than with that reported by other citizen science projects. This may help explain why a third of all respondents are an author or co-author of a paper in an astronomical journal. Finally, there is some evidence that participation in the AAVSO has a greater impact on the respondents' view of their role in astronomy compared to that expected through increasing amateur astronomy experience alone.

  20. Household demographic determinants of Ebola epidemic risk.

    Science.gov (United States)

    Adams, Ben

    2016-03-07

    A salient characteristic of Ebola, and some other infectious diseases such as Tuberculosis, is intense transmission among small groups of cohabitants and relatively limited indiscriminate transmission in the wider population. Here we consider a mathematical model for an Ebola epidemic in a population structured into households of equal size. We show that household size, a fundamental demographic unit, is a critical factor that determines the vulnerability of a community to epidemics, and the effort required to control them. Our analysis is based on the household reproduction number, but we also consider the basic reproduction number, intrinsic growth rate and final epidemic size. We show that, when other epidemiological parameters are kept the same, all of these quantifications of epidemic growth and size are increased by larger households and more intense within-household transmission. We go on to model epidemic control by case detection and isolation followed by household quarantine. We show that, if household quarantine is ineffective, the critical probability with which cases must be detected to halt an epidemic increases significantly with each increment in household size and may be a very challenging target for communities composed of large households. Effective quarantine may, however, mitigate the detrimental impact of large household sizes. We conclude that communities composed of large households are fundamentally more vulnerable to epidemics of infectious diseases primarily transmitted by close contact, and any assessment of control strategies for these epidemics should take into account the demographic structure of the population. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Material Stock Demographics: Cars in Great Britain.

    Science.gov (United States)

    Cabrera Serrenho, André; Allwood, Julian M

    2016-03-15

    Recent literature on material flow analysis has been focused on quantitative characterization of past material flows. Fewer analyses exist on past and prospective quantification of stocks of materials in-use. Some of these analyses explore the composition of products' stocks, but a focus on the characterization of material stocks and its relation with service delivery is often neglected. We propose the use of the methods of human demography to characterize material stocks, defined herein as stock demographics, exploring the insights that this approach could provide for the sustainable management of materials. We exemplify an application of stock demographics by characterizing the composition and service delivery of iron, steel, and aluminum stocks of cars in Great Britain, 2002-2012. The results show that in this period the stock has become heavier, it is traveling less, and it is idle for more time. The visualization of material stocks' dynamics demonstrates the pace of product replacement as a function of its usefulness and enables the formulation of policy interventions and the exploration of future trends.

  2. Changing demographics: what to watch for.

    Science.gov (United States)

    Morrison, P A

    1987-07-01

    Four broad demographic transformations: 1) the population's reconfiguration into smaller household units, especially those comprised of persons living alone; 2) changing employment patterns, notably the shift of married women into paid employment and the resulting proliferation of dual-earner families; 3) transformations in the population's age composition; and 4) the geography of growth in terms of regions that will gain or lose population--can be expected to have a profound impact on opportunities and challenges facing the business sector. The number of future households is projected to increase from 88.6 million in 1986 to 101.5 million by 1996. The sharpest gains will be among households headed by persons ranging in age from the late 30s to the early 50s. The fastest growth through the year 2000 is expected to occur in the Mountain states of the US. Business economists should be alert to these demographic analyses both to spot emerging growth markets and to identify long-term strategic issues, especially as the labor market changes. It will be increasingly important to differentiate time-sensitive from price-sensitive consumers.

  3. Child survival and the demographic "trap".

    Science.gov (United States)

    Kalish, S

    1992-02-01

    A debate within the UK public health community has centered around the feasibility of campaigns to improve child survival rates in Africa in the absence of equally aggressive efforts to increase family planning acceptance. The central spokesperson in this debate, Maurice King of the University of Leeds, has argued that population growth in sub-Saharan countries is undermining the carrying capacity of available resources and threatening ecological collapse. These countries are not exhibiting the characteristic demographic transition pattern, in which declining death rates eventually create conditions conducive to lower birth rates. Instead, they have fallen into a "demographic trap " in which population increases are outstripping growth in food production. To remedy this situation, King advocates the introduction of the concept of sustainability of the ecological foundations of health into the World Health Organizations's official definition of health. Richard Jolly of UNICEF has countered King's articles with the insistence that UNICEF has long supported child survival within the broader context of family planning provision and advocacy of birth spacing.

  4. Demographic Characteristics of Strokes Types in Sanliurfa

    Directory of Open Access Journals (Sweden)

    Yusuf Ižnanc

    2016-01-01

    Full Text Available Aim: Sanliurfa training and research hospital for diagnosis and treatment of patients with stroke admitted demographic features planned. We aimed to study demographic feature of stroke patient who admitted to Sanliurfa training and research hospital for diagnosis and treatment. Material and Method: 01/10/2011 and 01/9/2012, ischemic and hemorrhagic brain training and research hospital in Sanliurfa vascular disease diagnosis and treatment without any exclusion criteria, patient sequential 454 retrospectively.Results: 366%u2019si 88 were ischemic, hemorrhagic stroke. 54.6% by sex male,% 45.4 were women. Average age: 67.86 di.56.3% radiologically roaming the front circulation infarct brain infarct% found the rear 23.2. Hospital stay duration: 9.27 day.. Hemorrhagic stroke was longer this Sura in the group. Mortality rate 4.6% in all in packaging (21 patients, ischemic in boots in 1.9% (7 patients, hemorrhagic of boots were found at 15.9% (14 patients.Discussion: our study of Sanliurfa province stroke data in terms of the region together, although a portion of their valuable results. In the summer, the ischemic stroke incidence is higher.

  5. Late adverse reactions to intravascular iodinated contrast media

    International Nuclear Information System (INIS)

    Webb, Judith A.W.; Stacul, Fulvio; Thomsen, Henrik S.; Morcos, Sameh K.

    2003-01-01

    Late adverse reactions to intravascular iodinated contrast media are defined as reactions occurring 1 h to 1 week after contrast medium injection. They have received increasing interest over the past decade, but their prevalence remains uncertain and their pathophysiology is not fully understood. The Contrast Media Safety Committee of the European Society of Urogenital Radiology decided to review the literature and to issue guidelines. An extensive literature search was carried out and summarized in a report. Based on the available information, simple guidelines have been drawn up. The report and guidelines were discussed at the 8th European Symposium on Urogenital Radiology in Genoa. Late adverse reactions after intravascular iodinated contrast medium include symptoms such as nausea, vomiting, headache, itching, skin rash, musculoskeletal pain, and fever. A significant proportion of these reactions is unrelated to the contrast medium; however, allergy-like skin reactions are well-documented side effects of contrast media with an incidence of approximately 2%. Late reactions appear to be commoner after non-ionic dimers. The majority of late skin reactions after contrast medium exposure are probably T-cell-mediated allergic reactions. Patients at increased risk of late skin reactions are those with a history of previous contrast medium reaction and those on interleukin-2 treatment. Most skin reactions are self-limiting and resolve within a week. Management is symptomatic and similar to the management of other drug-induced skin reactions. (orig.)

  6. The Politics of Rewriting History: New History Textbooks and Curriculum Materials in Russia

    Science.gov (United States)

    Zajda, Joseph; Zajda, Rea

    2003-07-01

    The collapse of communism in Russia in 1991 necessitated, among other things, the rewriting of school history textbooks, which had been dominated by Marxist-Leninist interpretations of historical events. The aim of this article is to evaluate the new postcommunist history taught in upper secondary schools, giving particular attention to how the models for Russian identity presented in the new textbooks redefine legitimate culture for students. Attention will also be given to the multiple perspectives on history that textbooks and other curriculum materials emphasize; these new methods contrast with the grand narrative that dominated the study of history before 1991.

  7. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

    Reddy, Nischita K; Ioncică, Ana Maria; Săftoiu, Adrian

    2011-01-01

    Contrast agents are increasingly being used to characterize the vasculature in an organ of interest, to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures. We review the mechanisms of action of first, second and third generation contrast...... agents and their use in various endoscopic procedures in the gastrointestinal tract. Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy, assessment of depth of invasion of esophageal, gastric and gall bladder...... cancers and visualization of the portal venous system and esophageal varices. In addition, contrast agents can be used to differentiate pancreatic lesions. The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies. The sensitivity of power Doppler...

  8. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    MRI contrast agent is injected intravenously and T1-weighted images are acquired in the subsequent arterial first-pass phase. In order to achieve high quality MR angiograms without interfering venous contamination or artifacts, a number of factors need to be taken into account. This includes magnetic......-state MRA. Gadolinium(Gd)-based contrast agents are used for CE-MRA of the peripheral arteries. Extracellular Gd agents have a pharmacokinetic profile similar to iodinated contrast media. Accordingly, these agents are employed for first-pass MRA. Blood-pool Gd-based agents are characterized by prolonged...... intravascular stay, due to macromolecular structure or protein binding. These agents can be used for first-pass, as well as steady-state MRA. Some Gd-based contrast agents with low thermodynamic stability have been linked to development of nephrogenic systemic fibrosis in patients with severe renal...

  9. Composite likelihood estimation of demographic parameters

    Directory of Open Access Journals (Sweden)

    Garrigan Daniel

    2009-11-01

    Full Text Available Abstract Background Most existing likelihood-based methods for fitting historical demographic models to DNA sequence polymorphism data to do not scale feasibly up to the level of whole-genome data sets. Computational economies can be achieved by incorporating two forms of pseudo-likelihood: composite and approximate likelihood methods. Composite likelihood enables scaling up to large data sets because it takes the product of marginal likelihoods as an estimator of the likelihood of the complete data set. This approach is especially useful when a large number of genomic regions constitutes the data set. Additionally, approximate likelihood methods can reduce the dimensionality of the data by summarizing the information in the original data by either a sufficient statistic, or a set of statistics. Both composite and approximate likelihood methods hold promise for analyzing large data sets or for use in situations where the underlying demographic model is complex and has many parameters. This paper considers a simple demographic model of allopatric divergence between two populations, in which one of the population is hypothesized to have experienced a founder event, or population bottleneck. A large resequencing data set from human populations is summarized by the joint frequency spectrum, which is a matrix of the genomic frequency spectrum of derived base frequencies in two populations. A Bayesian Metropolis-coupled Markov chain Monte Carlo (MCMCMC method for parameter estimation is developed that uses both composite and likelihood methods and is applied to the three different pairwise combinations of the human population resequence data. The accuracy of the method is also tested on data sets sampled from a simulated population model with known parameters. Results The Bayesian MCMCMC method also estimates the ratio of effective population size for the X chromosome versus that of the autosomes. The method is shown to estimate, with reasonable

  10. Demographic Characteristics, Phenomenology, Comorbidity, and Family History in 200 Individuals With Body Dysmorphic Disorder

    Science.gov (United States)

    Phillips, Katharine A.; Menard, William; Fay, Christina; Weisberg, Risa

    2005-01-01

    The authors examined characteristics of body dysmorphic disorder in the largest sample for which a wide range of clinical features has been reported. The authors also compared psychiatrically treated and untreated subjects. Body dysmorphic disorder usually began during adolescence, involved numerous body areas and behaviors, and was characterized by poor insight, high comorbidity rates, and high rates of functional impairment, suicidal ideation, and suicide attempts. There were far more similarities than differences between the currently treated and untreated subjects, although the treated subjects displayed better insight and had more comorbidity. PMID:16000674

  11. The genetic structure of populations from Haiti and Jamaica reflect divergent demographic histories.

    Science.gov (United States)

    Simms, Tanya M; Rodriguez, Carol E; Rodriguez, Rosa; Herrera, Rene J

    2010-05-01

    The West Indies represent an amalgamation of African, European and in some cases, East Asian sources, but the contributions from each ethnic group remain relatively unexplored from a genetic perspective. In the present study, we report, for the first time, allelic frequency data across the complete set of 15 autosomal STR loci for general collections from Haiti and Jamaica, which were subsequently used to examine the genetic diversity present in each island population. Our results indicate that although both Haiti and Jamaica display genetic affinities with the continental African collections, a stronger African signal is detected in Haiti than in Jamaica. Although only minimal contributions from non-African sources were observed in Haiti, Jamaica displays genetic input from both European and East Asian sources, an admixture profile similar to other New World collections of African descent analyzed in this report. The divergent genetic signatures present in these populations allude to the different migratory events of Africans, Europeans, and East Asians into the New World.

  12. The effect of ancient DNA damage on inferences of demographic histories

    DEFF Research Database (Denmark)

    Axelsson, Erik; Willerslev, Eske; Gilbert, Marcus Thomas Pius

    2008-01-01

    The field of ancient DNA (aDNA) is casting new light on many evolutionary questions. However, problems associated with the postmortem instability of DNA may complicate the interpretation of aDNA data. For example, in population genetic studies, the inclusion of damaged DNA may inflate estimates o...... for a change in effective population size in this data set vanishes once the effects of putative damage are removed. Our results suggest that population genetic analyses of aDNA sequences, which do not accurately account for damage, should be interpreted with great caution....

  13. Whole-genome sequence variation, population structure and demographic history of the Dutch population

    NARCIS (Netherlands)

    Francioli, Laurent C.; Menelaou, Andronild; Pulit, Sara L.; Van Dijk, Freerk; Palamara, Pier Francesco; Elbers, Clara C.; Neerincx, Pieter B. T.; Ye, Kai; Guryev, Victor; Kloosterman, Wigard P.; Deelen, Patrick; Abdellaoui, Abdel; Van Leeuwen, Elisabeth M.; Van Oven, Mannis; Vermaat, Martijn; Li, Mingkun; Laros, Jeroen F. J.; Karssen, Lennart C.; Kanterakis, Alexandros; Amin, Najaf; Hottenga, Jouke Jan; Lameijer, Eric-Wubbo; Kattenberg, Mathijs; Dijkstra, Martijn; Byelas, Heorhiy; Van Settenl, Jessica; Van Schaik, Barbera D. C.; Bot, Jan; Nijman, Isaac J.; Renkens, Ivo; Marscha, Tobias; Schonhuth, Alexander; Hehir-Kwa, Jayne Y.; Handsaker, Robert E.; Polak, Paz; Sohail, Mashaal; Vuzman, Dana; Hormozdiari, Fereydoun; Van Enckevort, David; Mei, Hailiang; Koval, Vyacheslav; Moed, Ma-Tthijs H.; Van der Velde, K. Joeri; Rivadeneira, Fernando; Estrada, Karol; Medina-Gomez, Carolina; Isaacs, Aaron; Platteel, Mathieu; Swertz, Morris A.; Wijmenga, Cisca

    Whole-genome sequencing enables complete characterization of genetic variation, but geographic clustering of rare alleles demands many diverse populations be studied. Here we describe the Genome of the Netherlands (GoNL) Project, in which we sequenced the whole genomes of 250 Dutch parent-offspring

  14. Speciation and demographic history of Atlantic eels (Anguilla anguilla and A. rostrata) revealed by mitogenome sequencing

    DEFF Research Database (Denmark)

    Jacobsen, M.W.; Pujolar, J.M.; Gilbert, M.T.P.

    2014-01-01

    Processes leading to speciation in oceanic environments without obvious physical barriers remain poorly known. European and American eel (Anguilla anguilla and A. rostrata) spawn in partial sympatry in the Sargasso Sea. Larvae are advected by the Gulf Stream and other currents towards the Europea...

  15. The effects of Medieval dams on genetic divergence and demographic history in brown trout populations.

    Science.gov (United States)

    Hansen, Michael M; Limborg, Morten T; Ferchaud, Anne-Laure; Pujolar, José-Martin

    2014-06-05

    Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600-800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence times ca. 600-800 years bp, providing strong evidence for establishment of dams in the Medieval as the factor causing divergence. Bayesian cluster analysis showed influence of stocked trout in several reference populations, but not in the focal lake and anadromous populations. Estimates of effective population size using a linkage disequilibrium method ranged from 244 to > 1,000 in all but one anadromous population, but were lower (153 and 252) in the lake populations. We show that genetic divergence of lake-dwelling trout in two Danish lakes reflects establishment of water mills and impassable dams ca. 600-800 years ago rather than a natural genetic population structure. Although effective population sizes of the two lake populations are not critically low they may ultimately limit response to selection and thereby future adaptation. Our results demonstrate that populations may have been affected by anthropogenic disturbance over longer time scales than normally assumed.

  16. The effects of medieval dams on genetic divergence and demographic history in brown trout populations

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Limborg, Morten; Ferchaud, A.-L.

    2014-01-01

    Background: Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River......, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600-800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally...... genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Results: Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence...

  17. Whole-genome sequence variation, population structure and demographic history of the Dutch population

    NARCIS (Netherlands)

    The Genome of the Netherlands Consortium; T. Marschall (Tobias); A. Schönhuth (Alexander)

    2014-01-01

    htmlabstractWhole-genome sequencing enables complete characterization of genetic variation, but geographic clustering of rare alleles demands many diverse populations be studied. Here we describe the Genome of the Netherlands (GoNL) Project, in which we sequenced the whole genomes of 250 Dutch

  18. Stock structure and demographic history of the Indo-West Pacific mud crab Scylla serrata

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2010-01-01

    The increasing exploitation of mangrove forests, without any sustainable planning, has been seriously compromising the survival of this ecosystem and of its exclusive resources. Scylla serrata is one of the most commercially exploited crabs inhabiting mangroves and estuaries of the Indo-Pacific region. This species is extensively harvested, mainly for selling to the tourist market, and, as a consequence, its populations are in constant decline. The aim of the present study was to assess the level of genetic exchange of S. serrata within the Western Indian Ocean (WIO), using a population genetic structure approach. To achieve this goal, we reconstructed the intra-specific geographic pattern of genetic variation by partial sequencing the mitochondrial DNA cytochrome oxidase subunit I, in samples from seven mangrove sites of the WIO. Our data set then encompassed all the sequences for the same genetic marker deposited in Genbank and corresponding to samples from South East Asia, Australia and some Pacific Islands: this allowed us to estimate the level of connectivity among S. serrata populations within its distribution area. Our results show that an unique Scylla serrata metapopulation exists within the WIO; while throughout the entire Indo-Pacific region at least three distinct genetic stocks occur, corresponding to well-defined geographic regions (WIO, Eastern Australia and Pacific Ocean, North-Western Australia). South East China appears as the depositary of the most ancient haplotype and at the present time shares a haplotype with the Red Sea. The WIO populations show the signature of recent population bottlenecks, as expected for populations deeply exploited in a recent past. On the basis of our results, we can conclude that both the S. serrata populations and their habitats, i.e. mangrove forests and estuaries, of the WIO require future management and conservation regulations to avoiding overexploitation of this important key predator and marketable resource.

  19. Genetic stratigraphy of key demographic events in Arabia.

    Science.gov (United States)

    Fernandes, Verónica; Triska, Petr; Pereira, Joana B; Alshamali, Farida; Rito, Teresa; Machado, Alison; Fajkošová, Zuzana; Cavadas, Bruno; Černý, Viktor; Soares, Pedro; Richards, Martin B; Pereira, Luísa

    2015-01-01

    At the crossroads between Africa and Eurasia, Arabia is necessarily a melting pot, its peoples enriched by successive gene flow over the generations. Estimating the timing and impact of these multiple migrations are important steps in reconstructing the key demographic events in the human history. However, current methods based on genome-wide information identify admixture events inefficiently, tending to estimate only the more recent ages, as here in the case of admixture events across the Red Sea (~8-37 generations for African input into Arabia, and 30-90 generations for "back-to-Africa" migrations). An mtDNA-based founder analysis, corroborated by detailed analysis of the whole-mtDNA genome, affords an alternative means by which to identify, date and quantify multiple migration events at greater time depths, across the full range of modern human history, albeit for the maternal line of descent only. In Arabia, this approach enables us to infer several major pulses of dispersal between the Near East and Arabia, most likely via the Gulf corridor. Although some relict lineages survive in Arabia from the time of the out-of-Africa dispersal, 60 ka, the major episodes in the peopling of the Peninsula took place from north to south in the Late Glacial and, to a lesser extent, the immediate post-glacial/Neolithic. Exchanges across the Red Sea were mainly due to the Arab slave trade and maritime dominance (from ~2.5 ka to very recent times), but had already begun by the early Holocene, fuelled by the establishment of maritime networks since ~8 ka. The main "back-to-Africa" migrations, again undetected by genome-wide dating analyses, occurred in the Late Glacial period for introductions into eastern Africa, whilst the Neolithic was more significant for migrations towards North Africa.

  20. Demographic evidence of illegal harvesting of an endangered asian turtle.

    Science.gov (United States)

    Sung, Yik-Hei; Karraker, Nancy E; Hau, Billy C H

    2013-12-01

    Harvesting pressure on Asian freshwater turtles is severe, and dramatic population declines of these turtles are being driven by unsustainable collection for food markets, pet trade, and traditional Chinese medicine. Populations of big-headed turtle (Platysternon megacephalum) have declined substantially across its distribution, particularly in China, because of overcollection. To understand the effects of chronic harvesting pressure on big-headed turtle populations, we examined the effects of illegal harvesting on the demography of populations in Hong Kong, where some populations still exist. We used mark-recapture methods to compare demographic characteristics between sites with harvesting histories and one site in a fully protected area. Sites with a history of illegal turtle harvesting were characterized by the absence of large adults and skewed ratios of juveniles to adults, which may have negative implications for the long-term viability of populations. These sites also had lower densities of adults and smaller adult body sizes than the protected site. Given that populations throughout most of the species' range are heavily harvested and individuals are increasingly difficult to find in mainland China, the illegal collection of turtles from populations in Hong Kong may increase over time. Long-term monitoring of populations is essential to track effects of illegal collection, and increased patrolling is needed to help control illegal harvesting of populations, particularly in national parks. Because few, if any, other completely protected populations remain in the region, our data on an unharvested population of big-headed turtles serve as an important reference for assessing the negative consequences of harvesting on populations of stream turtles. Evidencia Demográfica de la Captura Ilegal de una Tortuga Asiática en Peligro. © 2013 Society for Conservation Biology.

  1. Evaluation of Socio-Demographic Characteristics of HIV/AIDS ...

    African Journals Online (AJOL)

    Evaluation of Socio-Demographic Characteristics of HIV/AIDS Patients in a Tertiary Hospital. ... Journal of Pharmaceutical and Allied Sciences. Journal Home ... Keywords: Socio-demographics, HIV/AID, Retrospective, Teaching hospital ...

  2. Contrast media: interactions with other drugs and clinical tests

    International Nuclear Information System (INIS)

    Morcos, Sameh K.; Exley, C.M.; Thomsen, Henrik S.

    2005-01-01

    Many patients with multiple medical problems who are receiving a variety of drugs are investigated with imaging techniques which require intravascular contrast media. The Contrast Media Safety Committee of the European Society of Urogenital Radiology therefore decided to review the literature and to draw up simple guidelines on interactions between contrast media and other drugs. An extensive literature search was carried out and summarized in a report. Based on the available information, simple guidelines have been drawn up. The report and guidelines were discussed at the 11th European Symposium on Urogenital Radiology in Santiago de Compostela. Contrast media may interact with other drugs, and may interfere with isotope studies and biochemical measurements. Awareness of the patient drug history is important to avoid potential hazards. Simple guidelines are presented. (orig.)

  3. Contrast Media: Are There Differences in Nephrotoxicity among Contrast Media?

    Science.gov (United States)

    2014-01-01

    Iodinated contrast agents are usually classified based upon their osmolality—high, low, and isosmolar. Iodinated contrast agents are also nephrotoxic in some but not all patients resulting in loss of glomerular filtration rate. Over the past 30 years, nephrotoxicity has been linked to osmolality although the precise mechanism underlying such a link has been elusive. Improvements in our understanding of the pathogenesis of nephrotoxicity and prospective randomized clinical trials have attempted to further explore the relationship between osmolality and nephrotoxicity. In this review, the basis for our current understanding that there are little if any differences in nephrotoxic potential between low and isosmolar contrast media will be detailed using data from clinical studies. PMID:24587997

  4. Chiropractors in Finland – a demographic survey

    Directory of Open Access Journals (Sweden)

    Malmqvist Stefan

    2008-08-01

    Full Text Available Abstract Background The Finnish chiropractic profession is young and not fully accepted by Finnish healthcare authorities. The demographic profile and style of practice has not been described to date. However, as the profession seems to be under rapid development, it would be of interest to stakeholders, both chiropractic and political, to obtain a baseline description of this profession with a view to the development of future goals and strategies for the profession. The purpose of this study was to describe the chiropractic profession in Finland in relation to its demographic background, the demographics of their clinics, practice patterns, interactions with other health care practitioners and some of the professions' plans for the future. Methods A structured questionnaire survey was conducted in 2005, in which all 50 members of the Finnish Chiropractic Union were invited to participate. Results In all, 44 questionnaires were returned (response rate 88%. Eighty percent of the respondents were men, and 77% were aged 30 to 44 years old, most of whom graduated after 1990 with either a university-based bachelors' or masters' degree in chiropractic. Solo practice was their main practice pattern. The vast majority described their scope of practice to be based on a musculoskeletal approach, using the Diversified Technique, performing Soft Tissue Therapy and about two-thirds also used an Activator Instrument (mechanical adjusting instrument. The mean number of patient visits reported to have been seen weekly was 59 of which nine were new patients. Most practitioners found this number of patients satisfactory. At the initial consultation, 80% of respondents spent 30–45 minutes with their patients, 75% spent 20–30 minutes with "new old" patients and on subsequent visits 80% of respondents spent 15–30 minutes. Interactions with other health care professions were reasonably good and most of chiropractors intended to remain within the profession

  5. Osteoblastic Metastases Mimickers on Contrast Enhanced CT

    Directory of Open Access Journals (Sweden)

    Fahad Al-Lhedan

    2017-01-01

    Full Text Available Secondary osseous involvement in lymphoma is more common compared to primary bone lymphoma. The finding of osseous lesion can be incidentally discovered during the course of the disease. However, osseous metastases are infrequently silent. Detection of osseous metastases is crucial for accurate staging and optimal treatment planning of lymphoma. The aim of imaging is to identify the presence and extent of osseous disease and to assess for possible complications such as pathological fracture of the load-bearing bones and cord compression if the lesion is spinal. We are presenting two patients with treated lymphoma who were in complete remission. On routine follow-up contrast enhanced CT, there were new osteoblastic lesions in the spine worrisome for metastases. Additional studies were performed for further evaluation of both of them which did not demonstrate any corresponding suspicious osseous lesion. The patients have a prior history of chronic venous occlusive thrombosis that resulted in collaterals formation. Contrast enhancement of the vertebral body marrow secondary to collaterals formation and venous flow through the vertebral venous plexus can mimic the appearance of spinal osteoblastic metastases.

  6. Land use and demographic grids in Cosyma

    International Nuclear Information System (INIS)

    Robinson, C.A.; Hasemann, I.

    1991-01-01

    The spatial distribution of the population, agricultural production, economic activity, and the position of land and sea, are important elements of accident consequence codes. These data are necessary in evaluating the health effects within the population arising from the external dose, inhalation and ingestion pathways. These distributions are also essential in calculating the economic impact of implementing countermeasures, such as relocation and food bans. This paper includes a discussion of the agricultural production and population distribution information available for EC countries, their resolution, availability and sources. The gridded data included in the COSYMA system are described. Particular aspects, such as the difficulties involved with using economic land use information, are also explained. Future developments, and their effect on the requirements for land use and demographic grids, are outlined

  7. 3D face analysis for demographic biometrics

    Energy Technology Data Exchange (ETDEWEB)

    Tokola, Ryan A [ORNL; Mikkilineni, Aravind K [ORNL; Boehnen, Chris Bensing [ORNL

    2015-01-01

    Despite being increasingly easy to acquire, 3D data is rarely used for face-based biometrics applications beyond identification. Recent work in image-based demographic biometrics has enjoyed much success, but these approaches suffer from the well-known limitations of 2D representations, particularly variations in illumination, texture, and pose, as well as a fundamental inability to describe 3D shape. This paper shows that simple 3D shape features in a face-based coordinate system are capable of representing many biometric attributes without problem-specific models or specialized domain knowledge. The same feature vector achieves impressive results for problems as diverse as age estimation, gender classification, and race classification.

  8. Extraparenchymal neurocysticercosis: Demographic, clinicoradiological, and inflammatory features.

    Directory of Open Access Journals (Sweden)

    Mariana Marcin Sierra

    2017-06-01

    Full Text Available Extraparenchymal neurocysticercosis (ExPNCC, an infection caused by Taenia solium cysticerci that mainly occurs in the ventricular compartment (Ve or the basal subarachnoid space (SAb, is more severe but less frequent and much less studied than parenchymal neurocysticercosis (ParNCC. Demographic, clinical, radiological, and lumbar cerebrospinal fluid features of patients affected by ExPNCC are herein described and compared with those of ParNCC patients.429 patients with a confirmed diagnosis of neurocysticercosis, attending the Instituto Nacional de Neurología y Neurocirugía, a tertiary reference center in Mexico City, from 2000 through 2014, were included. Demographic information, signs and symptoms, radiological patterns, and lumbar cerebrospinal fluid (CSF laboratory values were retrieved from medical records for all patients. Data were statistically analyzed to assess potential differences depending on cyst location and to determine the effects of age and sex on the disease presentation. In total, 238 ExPNCC and 191 ParNCC patients were included. With respect to parenchymal cysts, extraparenchymal parasites were diagnosed at an older age (P = 0.002, chiefly caused intracranial hypertension (P < 0.0001, were more frequently multiple and vesicular (P < 0.0001, and CSF from these patients showed higher protein concentration and cell count (P < 0.0001. SAb patients were diagnosed at an older age than Ve patients, and showed more frequently seizures, vesicular cysticerci, and higher CSF cellularity. Gender and age modulated some traits of the disease.This study evidenced clear clinical, radiological, and inflammatory differences between ExPNCC and ParNCC, and between SAb and Ve patients, and demonstrated that parasite location determines different pathological entities.

  9. Demographic patterns and sustainable development in Ghana.

    Science.gov (United States)

    Tawiah, E O

    1995-01-01

    There is a growing recognition that the present demographic patterns in sub-Saharan Africa, including Ghana, do not augur well for the achievement of sustainable development. Ghana is characterized by a youthful population, rapid population growth, uneven population distribution, high fertility, and rural-urban migration which has brought human numbers into collision with resources to sustain them. It is submitted that the issues discussed are equally applicable to the subregion as well. The estimated population in 1993 was about 16.4 million. The population of Ghana increased from 1970 to 1984 at a rate of growth of 2.6% per annum. The proliferation of small settlements has serious implications for sustainable development. Urban centers comprised about 12.9% of the total population in 1948, 23% in 1960, 28.3% in 1970, and 31.3% in 1984. The average woman in Ghana still has more than six children. The 1988 Ghana Demographic and Health Survey (GDHS) indicated that the median age at first marriage for women was 16.5 years. Contraceptive use is low in sub-Sahara Africa. Currently married women (15-49) currently using any modern method ranged from 1% in Burundi (1987) and Mali (1987) to 36% in Zimbabwe (1988/89). The rapid population growth in Ghana, coupled with the concentration of infrastructural facilities and job opportunities in the urban centers, has resulted in a massive rural-urban migration. Basic social facilities like health, water, housing, and electricity have been stretched to their breakpoints. The Government of Ghana initiated a major effort to put environmental issues on the priority agenda in March 1988. This led to the preparation of an Environmental Action Plan (EAP) in 1991 to address issues relating to the protection of the environment, but the need is still urgent to adopt relevant population policies as a basic strategy in sustainable development.

  10. How to misuse echo contrast

    Directory of Open Access Journals (Sweden)

    Missios Anna

    2009-01-01

    Full Text Available Abstract Background Primary intracardiac tumours are rare, there are however several entities that can mimic tumours. Contrast echocardiography has been suggested to aid the differentiation of various suspected masses. We present a case where transthoracic echocardiography completely misdiagnosed a left atrial mass, partly due to use of echo contrast. Case presentation An 80 year-old woman was referred for transthoracic echocardiography because of one-month duration of worsening of dyspnoea. Transthoracic echocardiography displayed a large echodense mass in the left atrium. Intravenous injection of contrast (SonoVue, Bracco Inc., It indicated contrast-enhancement of the structure, suggesting tumour. Transesophageal echocardiography revealed, however, a completely normal finding in the left atrium. Subsequent gastroscopy examination showed a hiatal hernia. Conclusion It is noteworthy that the transthoracic echocardiographic exam completely misdiagnosed what seemed like a left atrial mass, which in part was an effect of the use of echo contrast. This example highlights that liberal use of transoesophageal echocardiography is often warranted if optimal display of cardiac structures is desired.

  11. NOAA History - Main Page

    Science.gov (United States)

    NOAA History Banner gold bar divider home - takes you to index page about the site contacts noaa americas science and service noaa legacy 1807 - 2007 NOAA History is an intrinsic part of the history of Initiative scroll divider More NOAA History from Around the Nation scroll divider drawing of a tornado NOAA

  12. Reinventing Entrepreneurial History

    DEFF Research Database (Denmark)

    Wadhwani, R. Daniel; Lubinski, Christina

    2017-01-01

    Research on entrepreneurship remains fragmented in business history. A lack of conceptual clarity inhibits comparisons between studies and dialogue among scholars. To address these issues, we propose to reinvent entrepreneurial history as a research field. We define “new entrepreneurial history...... and reconfiguring resources, and legitimizing novelty. The article elaborates on the historiography, premises, and potential contributions of new entrepreneurial history....

  13. Kiropraktikkens historie i Danmark

    DEFF Research Database (Denmark)

    Jørgensen, Per

    Bogen er den første samlede, forskningsbaserede fremstilling om kiropraktikkens danske historie. Den har udblik til kiropraktikkens historie i USA.......Bogen er den første samlede, forskningsbaserede fremstilling om kiropraktikkens danske historie. Den har udblik til kiropraktikkens historie i USA....

  14. Energy and water budgets of larks in a life history perspective : Parental effort varies with aridity

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Visser, GH

    We compared physiological, demographic, and ecological variables of larks to gain insights into life history variation along an aridity gradient, incorporating phylogenetic relationships in analyses when appropriate. Quantifying field metabolic rate (FMR). and water influx rate (WIR) of parents

  15. Cosmic growth history and expansion history

    International Nuclear Information System (INIS)

    Linder, Eric V.

    2005-01-01

    The cosmic expansion history tests the dynamics of the global evolution of the universe and its energy density contents, while the cosmic growth history tests the evolution of the inhomogeneous part of the energy density. Precision comparison of the two histories can distinguish the nature of the physics responsible for the accelerating cosmic expansion: an additional smooth component--dark energy--or a modification of the gravitational field equations. With the aid of a new fitting formula for linear perturbation growth accurate to 0.05%-0.2%, we separate out the growth dependence on the expansion history and introduce a new growth index parameter γ that quantifies the gravitational modification

  16. Demographic change and marriage choices in one Carib family.

    Science.gov (United States)

    Adams, K

    1994-03-01

    The demographic adaptation of a family of Topside Caribs along the Barama River in Guyana was studied. The family history included two grandfather and granddaughter marriages. Jack Raymond's father, who was born in 1870, left Bottomside after the death of his wife in the 1920s and settled above the falls of the Barama River (Topside in Sawari) with the hope of subsistence living off the rain forest. Information on the grandfather generation was made difficult by name changes, general references to all men in the second generation as grandfathers, and the focus on father's and mother's generation. The typical pattern was for brothers to live close by, and intermarry with a family of sisters. Female children married mother's brothers' sons or father's sisters sons. Their children formed their own cluster settlements. The early history indicated economic hardship, loss of wives, and difficulties in remarrying. The Baird chronicles of the reintroduction of gold mining and the ethnography of Gillin indicated that malaria and round worm were diseases affecting the indigenous population during the 1920s and 1930s. The Topside population was supported by the local gold-mining economy, while the Bottomside population suffered economic hardship and high infant mortality. In the Jack Raymond family, remarriage resulted in children marrying cross cousins. The younger daughter married in the 1940s, when subsistence production of cassava and hunting and gold-mining income provided the family's livelihood. The daughter had 10 surviving children, compared to her adoptive mother's two. For the daughter's generation, the first pregnancy occurred between the ages of 18 and 22 years, and birth spacing was 20-30 months for 25 years. Neither polygyny nor monogamy affected the potential for 12 children. In this Baramita Air Strip population in 1971, there were 62 mothers; reproductive histories were available for 59. The changes in reproductive patterns after 1940 were apparent: for

  17. Multiscale image contrast amplification (MUSICA)

    Science.gov (United States)

    Vuylsteke, Pieter; Schoeters, Emile P.

    1994-05-01

    This article presents a novel approach to the problem of detail contrast enhancement, based on multiresolution representation of the original image. The image is decomposed into a weighted sum of smooth, localized, 2D basis functions at multiple scales. Each transform coefficient represents the amount of local detail at some specific scale and at a specific position in the image. Detail contrast is enhanced by non-linear amplification of the transform coefficients. An inverse transform is then applied to the modified coefficients. This yields a uniformly contrast- enhanced image without artefacts. The MUSICA-algorithm is being applied routinely to computed radiography images of chest, skull, spine, shoulder, pelvis, extremities, and abdomen examinations, with excellent acceptance. It is useful for a wide range of applications in the medical, graphical, and industrial area.

  18. Contrast enhancement CT by iopamidol

    International Nuclear Information System (INIS)

    Mori, Masaki; Makita, Nobue; Yanai, Kyoko

    1984-01-01

    In order to evaluate the contrast enhancement effect and safety of iopamidol (IOP) in CT examination, IOP was compared with angiographin (AG). In the liver and abdominal aorta, peak CT values were obtained earlier and were higher in the group with AG than in the group with IOP. However, CT values in the group with IOP decreased a little more slowly than those in the group with AG. There was no significant difference in the effect on contrast enhancement between the groups. Intravenous injection of IOP caused lower degree of burning sensation than that of AG, and some of the patients with IOP did not feel burning sensation at all. Changes in clinical laboratory values were slight before and after intravenous injection of IOP. These results suggest that IOP is satisfactory in terms of safety and effect on contrast enhancement in CT examination. (Namekawa, K.)

  19. THE COMPARISONS AND CONTRASTS BETWEEN ENGLISH AND MALAY LANGUAGES

    Directory of Open Access Journals (Sweden)

    Mohd Nazri Latiff Azmi

    2016-06-01

    Full Text Available English and Malay languages are categorized as popular languages in the world. However, both languages underwent different history and composition. This study investigates the languages in terms of history, phonology, loanwords, grammar, morphology and semantics. The purposes of studying the comparisons and contrasts of both languages are not only to analyze the uniqueness of the languages but also to identify the process of understanding the languages especially the view of second language learners. It is found that two languages come from different background; somehow they share similar characteristics such as the vowels sounds, loanwords and semantics. However, the learners face difficulty in learning both languages especially in pronunciations and spelling.

  20. Contrast-guided image interpolation.

    Science.gov (United States)

    Wei, Zhe; Ma, Kai-Kuang

    2013-11-01

    In this paper a contrast-guided image interpolation method is proposed that incorporates contrast information into the image interpolation process. Given the image under interpolation, four binary contrast-guided decision maps (CDMs) are generated and used to guide the interpolation filtering through two sequential stages: 1) the 45(°) and 135(°) CDMs for interpolating the diagonal pixels and 2) the 0(°) and 90(°) CDMs for interpolating the row and column pixels. After applying edge detection to the input image, the generation of a CDM lies in evaluating those nearby non-edge pixels of each detected edge for re-classifying them possibly as edge pixels. This decision is realized by solving two generalized diffusion equations over the computed directional variation (DV) fields using a derived numerical approach to diffuse or spread the contrast boundaries or edges, respectively. The amount of diffusion or spreading is proportional to the amount of local contrast measured at each detected edge. The diffused DV fields are then thresholded for yielding the binary CDMs, respectively. Therefore, the decision bands with variable widths will be created on each CDM. The two CDMs generated in each stage will be exploited as the guidance maps to conduct the interpolation process: for each declared edge pixel on the CDM, a 1-D directional filtering will be applied to estimate its associated to-be-interpolated pixel along the direction as indicated by the respective CDM; otherwise, a 2-D directionless or isotropic filtering will be used instead to estimate the associated missing pixels for each declared non-edge pixel. Extensive simulation results have clearly shown that the proposed contrast-guided image interpolation is superior to other state-of-the-art edge-guided image interpolation methods. In addition, the computational complexity is relatively low when compared with existing methods; hence, it is fairly attractive for real-time image applications.

  1. Iodinated contrast media nephrotoxicity. Nephrotoxicite des produits de contraste iodes

    Energy Technology Data Exchange (ETDEWEB)

    Meyrier, A. (Hopital Avicenne, 93 - Bobigny (France))

    1994-01-01

    In the late seventies, iodinated contrast agents (ICA) were considered to be a major cause of acute iatrogenic renal failure. Over the last decade new contrast agents have been synthesized, nonionic and less hyperosmolar. The incidence of acute renal failure due to ICAs, varies from 3.7 to 70% of cases according to the series, with an average figure of 10.2%. The pathophysiology of ICA nephrotoxicity was mainly studied in laboratory animal models. Three main factors are involved in an inducing ICA-mediated decrease in glomerular filtration rate: reduction of the renal plasma flow, a direct cytotoxic effect on renal tubular cells and erythrocyte alteration leading to intra-renal sludge. Excluding dysglobulinemias with urinary excretion of immunoglobulin light chains, which represent a special case of maximum nephrotoxicity, 4 main risk factors of renal toxicity have been identified in nondiabetic subjects: previous renal failure with serum creatinine levels greater than 140 [mu]mol per liter, extracellular dehydration, age over 60 and use of high doses of ICA and/or repeated ICA injections before serum creatinine levels return to baseline. Preventive measures for avoiding ICA nephrotoxicity are threefold: maintain or restore adequate hydration with saline infusion, stop NSAID treatment several days before ICA administration, and allow a 5 day interval before repeating contrast media injections. New, nonionic and moderately hyperosmolar contrast agents appear to be much less nephrotoxic than conventional ICAs in laboratory animals and in high-risk patients. It is advisable to select such contrast media for investigating high-risk patients. This approach was recently substantiated in well designed, randomized clinical studies which included more than 2 000 patients. (author).

  2. Quantitative contrast-enhanced mammography for contrast medium kinetics studies

    Science.gov (United States)

    Arvanitis, C. D.; Speller, R.

    2009-10-01

    Quantitative contrast-enhanced mammography, based on a dual-energy approach, aims to extract quantitative and temporal information of the tumour enhancement after administration of iodinated vascular contrast media. Simulations using analytical expressions and optimization of critical parameters essential for the development of quantitative contrast-enhanced mammography are presented. The procedure has been experimentally evaluated using a tissue-equivalent phantom and an amorphous silicon active matrix flat panel imager. The x-ray beams were produced by a tungsten target tube and spectrally shaped using readily available materials. Measurement of iodine projected thickness in mg cm-2 has been performed. The effect of beam hardening does not introduce nonlinearities in the measurement of iodine projected thickness for values of thicknesses found in clinical investigations. However, scattered radiation introduces significant deviations from slope equal to unity when compared with the actual iodine projected thickness. Scatter correction before the analysis of the dual-energy images provides accurate iodine projected thickness measurements. At 10% of the exposure used in clinical mammography, signal-to-noise ratios in excess of 5 were achieved for iodine projected thicknesses less than 3 mg cm-2 within a 4 cm thick phantom. For the extraction of temporal information, a limited number of low-dose images were used with the phantom incorporating a flow of iodinated contrast medium. The results suggest that spatial and temporal information of iodinated contrast media can be used to indirectly measure the tumour microvessel density and determine its uptake and washout from breast tumours. The proposed method can significantly improve tumour detection in dense breasts. Its application to perform in situ x-ray biopsy and assessment of the oncolytic effect of anticancer agents is foreseeable.

  3. Demographic monitoring of wild muriqui populations: Criteria for defining priority areas and monitoring intensity.

    Science.gov (United States)

    Strier, Karen B; Possamai, Carla B; Tabacow, Fernanda P; Pissinatti, Alcides; Lanna, Andre M; Rodrigues de Melo, Fabiano; Moreira, Leandro; Talebi, Maurício; Breves, Paula; Mendes, Sérgio L; Jerusalinsky, Leandro

    2017-01-01

    Demographic data are essential to assessments of the status of endangered species. However, establishing an integrated monitoring program to obtain useful data on contemporary and future population trends requires both the identification of priority areas and populations and realistic evaluations of the kinds of data that can be obtained under different monitoring regimes. We analyzed all known populations of a critically endangered primate, the muriqui (genus: Brachyteles) using population size, genetic uniqueness, geographic importance (including potential importance in corridor programs) and implementability scores to define monitoring priorities. Our analyses revealed nine priority populations for the northern muriqui (B. hypoxanthus) and nine for the southern muriqui (B. arachnoides). In addition, we employed knowledge of muriqui developmental and life history characteristics to define the minimum monitoring intensity needed to evaluate demographic trends along a continuum ranging from simple descriptive changes in population size to predictions of population changes derived from individual based life histories. Our study, stimulated by the Brazilian government's National Action Plan for the Conservation of Muriquis, is fundamental to meeting the conservation goals for this genus, and also provides a model for defining priorities and methods for the implementation of integrated demographic monitoring programs for other endangered and critically endangered species of primates.

  4. Demographic monitoring of wild muriqui populations: Criteria for defining priority areas and monitoring intensity.

    Directory of Open Access Journals (Sweden)

    Karen B Strier

    Full Text Available Demographic data are essential to assessments of the status of endangered species. However, establishing an integrated monitoring program to obtain useful data on contemporary and future population trends requires both the identification of priority areas and populations and realistic evaluations of the kinds of data that can be obtained under different monitoring regimes. We analyzed all known populations of a critically endangered primate, the muriqui (genus: Brachyteles using population size, genetic uniqueness, geographic importance (including potential importance in corridor programs and implementability scores to define monitoring priorities. Our analyses revealed nine priority populations for the northern muriqui (B. hypoxanthus and nine for the southern muriqui (B. arachnoides. In addition, we employed knowledge of muriqui developmental and life history characteristics to define the minimum monitoring intensity needed to evaluate demographic trends along a continuum ranging from simple descriptive changes in population size to predictions of population changes derived from individual based life histories. Our study, stimulated by the Brazilian government's National Action Plan for the Conservation of Muriquis, is fundamental to meeting the conservation goals for this genus, and also provides a model for defining priorities and methods for the implementation of integrated demographic monitoring programs for other endangered and critically endangered species of primates.

  5. Validity of self-reported periodontal measures, demographic characteristics and systemic medical conditions.

    Science.gov (United States)

    Chatzopoulos, Georgios S; Cisneros, Alejandro; Sanchez, Miguel; Lunos, Scott; Wolff, Larry F

    2018-04-06

    The objective of the present study was to assess self-reported periodontal screening questions, demographic characteristics, systemic medical conditions and tobacco use for predicting periodontal disease among individuals seeking dental therapy in a university dental clinic. In this retrospective study, a total of 4,890 randomly selected dental charts were evaluated from among patients who had attended the University of Minnesota School of Dentistry clinics for treatment. Radiographic bone loss measurements were utilized to assess the severity of periodontal disease. Demographic characteristics as well as medical history of the patients were also recorded. Five self-reported periodontal screening questions were included with the range of answers limited to Yes/No. Generalized logit models were used to assess the association between bone loss and the predictors. The sample mean age was 54.1 years and included 52.6% males and 14.9% smokers with a mean number of missing teeth of 3.5. Self-reported tooth mobility, history of "gum treatment" and the importance to keep the teeth as well as age, tobacco use and cancer were statistically significant (p brushing", gender, diabetes, anxiety and arthritis. Self-reported periodontal screening questions as well as demographic characteristics, smoking and systemic medical conditions were significant predictors of periodontal disease and they could be used as valid, economical and practical measures. This article is protected by copyright. All rights reserved. © 2018 American Academy of Periodontology.

  6. Experts Networks and the European Commission on Demographic Change

    DEFF Research Database (Denmark)

    Seabrooke, Leonard; Tsingou, Eleni; Willers, Johann Ole

    experts on demographic change. Our findings suggest that on demographic change issues at the EU level, DG EMPL has taken the lead, while DG ECFIN is the secondary actor. Still, internal European Commission dynamics mean that the lead actor on demographic issues has less autonomy in articulating a funded......This paper examines who populates the expert and policy network around demographic change issues in Europe. We examine how competing policy departments in the European Commission Directorates-General (DGs) deal with the issue of Europe’s changing demography, as well as discuss the role of external...... and clear policy position on how to address them. As a consequence, there is little institutional memory and hardly a depository of activity on demographic change. While outside expertise comes primarily from demographers, and other scholars concerned with demographic change, they are primarily an academic...

  7. Jewish history as a history of immigration: an overview of current historiography in the Scandinavian countries

    Directory of Open Access Journals (Sweden)

    Christhard Hoffmann

    2016-01-01

    Full Text Available This article provides a first critical overview of the historiography of Jewish immigration and integration in Sweden, Denmark and Norway. While the experience of immigration has been crucial for Scandinavian Jewry, scholarly interest in Jewish migration history only emerged during the 1980s in connection with the focus on migration and ethnicity in Swedish research and the adaptation of sociological concepts of migration in general historiography. By analysing key historio-graphical works, focusing on their approaches and main narratives, this article aims at a critical methodological self-reflection. It identifies two major approaches to Jewish immigration history in current Scandinavian historiography: the demographic and social history approach, focusing in particular on the role of Jewish immigrants in the labour market, their settlement and housing conditions and their social mobility; and the cultural history approach, reconstructing and preserving the vanished world of Yiddish immigrant culture.

  8. Impact of demographic policy on population growth.

    Science.gov (United States)

    Podyashchikh, P

    1968-01-01

    Various bourgeois theories, including the reactionary Malthusianism and its variants, challenge the Marxist-Leninist revolutionary theory on the growth of population. Bourgeois science maintains that unchanging biological laws of proliferation form the foundation of social life. Malthus, in his "An Essay on the Principle of Population," contends that population increases in a geometric rate, while means of subsistence tend to increase only in an arithmetic rate: neither the way of production nor social conditions but this law of nature in control of proliferation had been the cause of overpopulation, which again leads to misery, hunger, and unemployment. From this follows the possible conclusion that the working classes should be concerned not about how to change the social order but how to reduce the number of childbirths. Progressive science views the laws of social life in a totally different way. Marxism-Leninism teaches that population size, despite the markedly important role played by it in historical progress, fails to represent that main force of social progress which determines the mode of production and of the distribution of material goods, but just the reverse: the mode of production determines the growth of population, the changes in its density and composition. Marxism-Leninism teaches that each historical stage of production (slavery, feudalism, capitalism) has its own special, historically valid demographic law. Bourgeois science maintains that humankind faces an absolute overpopulation caused by the means of production lagging behind the growth of population. Actually this is only a relative overpopulation due to the fact that capitalistic production is subjected to the interests of increasing capitalistic profit and not to those of meeting the demands of population. In socialist countries, production is incessantly developing and expanding, and employment of the entire productive population is ensured. Consequently, the problem of relative

  9. Ultrasound Contrast Agent Microbubble Dynamics

    NARCIS (Netherlands)

    Overvelde, M.L.J.; Vos, Henk; de Jong, N.; Versluis, Michel; Paradossi, Gaio; Pellegretti, Paolo; Trucco, Andrea

    2010-01-01

    Ultrasound contrast agents are traditionally used in ultrasound-assisted organ perfusion imaging. Recently the use of coated microbubbles has been proposed for molecular imaging applications where the bubbles are covered with a layer of targeting ligands to bind specifically to their target cells.

  10. Color contrasting in radioscopy systems

    International Nuclear Information System (INIS)

    Lopaev, V.P.; Pavlov, S.V.; Nazarenko, V.G.

    1979-01-01

    Transformation principles for achromatic radioscopy control systems to color ones have been considered. Described is the developed ''Gamma 1'' roentgen-TV facility with color contrasting, which is based on the principle of analog conversion of brightness signal to a hue. By means of color channels amplifiers realized are the special amplitude characteristics, permitting in comparison with the common method of analogous transformation to obtain the greater number of hues within the identical range of brightnesses of image under investigation due to introducing purple colors. The investigation of amplitude resolution capability of color contrasting device has shown, that in the case of color contrasting of image the amplitude resolution is 1.7-1.8 time higher than in the case of achromatic one. Defectoscopic sensitivity during the testing of 5-20 mm thick steel products in the process of experimental-production tests turned out to be 1.1-1.3 time higher when using color contrasting of radioscopic image. Realization simplicity, high resolution, noise stability and wide functional possibilities of the facility show the prospects for its using during the quality control of welded joints in products of power engineering

  11. The shifting demographic landscape of pandemic influenza.

    Directory of Open Access Journals (Sweden)

    Shweta Bansal

    2010-02-01

    Full Text Available As Pandemic (H1N1 2009 influenza spreads around the globe, it strikes school-age children more often than adults. Although there is some evidence of pre-existing immunity among older adults, this alone may not explain the significant gap in age-specific infection rates.Based on a retrospective analysis of pandemic strains of influenza from the last century, we show that school-age children typically experience the highest attack rates in primarily naive populations, with the burden shifting to adults during the subsequent season. Using a parsimonious network-based mathematical model which incorporates the changing distribution of contacts in the susceptible population, we demonstrate that new pandemic strains of influenza are expected to shift the epidemiological landscape in exactly this way.Our analysis provides a simple demographic explanation for the age bias observed for H1N1/09 attack rates, and suggests that this bias may shift in coming months. These results have significant implications for the allocation of public health resources for H1N1/09 and future influenza pandemics.

  12. Population growth, demographic change, and cultural landscapes.

    Science.gov (United States)

    Woodgate, G; Sage, C

    1994-01-01

    The inclusion of both ecological and socioeconomic components within landscapes makes possible the perception of the hierarchical character of landscape organization. A research approach is needed to conceptualize cultural landscapes as the product of interaction between society and nature. Richard Norgaard's 1984 paper on coevolutionary agricultural development attempts to meet this challenge. Coevolution is the interactive synthesis of natural and social mechanisms of change that characterize the relationship between social systems and ecosystems. The relationship between population, consumption, and environmental changes is complex. Currently industrialized countries present the biggest threat to global environmental resources. The issue of carrying capacity is the corollary of population and the environment. It is primarily the technological factor rather than population that needs to be controlled. The relationship between rich and poor countries is determined by superior economic power. An analysis of landscape change is made, tracing the coevolution of society and environment from the end of the feudal era and making comparisons with continental Europe. Over the years since 1945 the need to realize potential economies of scale has resulted in a wholesale loss of woodlands, hedgerows, and small ponds in the UK. In a global context the likely impacts of population growth and demographic change on landscapes will be influenced by such socioeconomic factors as technology and affluence; policies that ignore cause and effect; and the traditional tendency to treat the environment as a waste repository and a supply depot.

  13. How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables.

    Science.gov (United States)

    Brooks, Mollie E; Mugabo, Marianne; Rodgers, Gwendolen M; Benton, Timothy G; Ozgul, Arpat

    2016-03-01

    Demographic rates are shaped by the interaction of past and current environments that individuals in a population experience. Past environments shape individual states via selection and plasticity, and fitness-related traits (e.g. individual size) are commonly used in demographic analyses to represent the effect of past environments on demographic rates. We quantified how well the size of individuals captures the effects of a population's past and current environments on demographic rates in a well-studied experimental system of soil mites. We decomposed these interrelated sources of variation with a novel method of multiple regression that is useful for understanding nonlinear relationships between responses and multicollinear explanatory variables. We graphically present the results using area-proportional Venn diagrams. Our novel method was developed by combining existing methods and expanding upon them. We showed that the strength of size as a proxy for the past environment varied widely among vital rates. For instance, in this organism with an income breeding life history, the environment had more effect on reproduction than individual size, but with substantial overlap indicating that size encompassed some of the effects of the past environment on fecundity. This demonstrates that the strength of size as a proxy for the past environment can vary widely among life-history processes within a species, and this variation should be taken into consideration in trait-based demographic or individual-based approaches that focus on phenotypic traits as state variables. Furthermore, the strength of a proxy will depend on what state variable(s) and what demographic rate is being examined; that is, different measures of body size (e.g. length, volume, mass, fat stores) will be better or worse proxies for various life-history processes. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

  14. Part 1: MRI features of focal nodular hyperplasia with an emphasis on hepatobiliary contrast agents

    International Nuclear Information System (INIS)

    Sutherland, Tom; Seale, Melanie; Yap, Yap

    2014-01-01

    Focal nodular hyperplasia (FNH) is the second most common benign liver tumour and typically do not require any treatment. An accurate non-invasive diagnosis is therefore vital to avoid unnecessary intervention and to reassure patients. This article discusses the demographics and pathology of FNH and reviews the appearance of FNH at MRI using liver-specific contrast agents.

  15. Clinical and Demographical Characteristics of Patients with Medication Overuse Headache in Argentina and Chile

    DEFF Research Database (Denmark)

    Shand, Beatriz; Goicochea, Maria Teresa; Valenzuela, Raul

    2015-01-01

    population was formed by 240 MOH subjects, 110 from Chile and 130 from Argentina, consecutively attending the local headache centres. In each centre, specifically trained neurologist interviewed and confirmed the diagnosis according to the ICHD-II criteria. A detailed history was collected on an electronic......BACKGROUND: Data on the characteristics of Medication Overuse Headache (MOH) in Latin American (LA) are scarce. Here we report the demographic and clinical features of the MOH patients from Argentina and Chile enrolled in the multinational COMOESTAS project in the period 2008-2010. METHODS: The LA......, where it affects mostly women, in the most active decades of life. Some differences emerge as regards the demographic and clinical characteristics of MOH in this population as compared to Europe or Northern America. What seems more worrying about MOH in Argentina and Chile is that most patients overuse...

  16. A demographic-economic explanation of political stability: Mauritius as a microcosm.

    Science.gov (United States)

    Lempert, D

    1987-06-01

    "This paper examines current models of economic and political development--social modernization theory, political and economic characteristics of stable regimes, and cross country analysis of political stability--and tests them on the Indian Ocean Island of Mauritius. The analysis continues with a causal explanation for political stability in Mauritius' recent history, derived from an examination of economic policies and demographic patterns. Political change in Mauritius over the past sixty years seems to be explained best by a model for political stability which integrates specific economic and demographic factors. The model, applicable to development in other third world nations, revises Malthus' conclusion that population and economic conditions move in an oscillatory relationship and replaces it with a more comprehensive theory, suggesting that political stability is a function of both economic development and a repeating cyclical relationship between economics and population." excerpt

  17. A review of small canned computer programs for survey research and demographic analysis.

    Science.gov (United States)

    Sinquefield, J C

    1976-12-01

    A variety of small canned computer programs for survey research and demographic analysis appropriate for use in developing countries are reviewed in this article. The programs discussed are SPSS (Statistical Package for the Social Sciences); CENTS, CO-CENTS, CENTS-AID, CENTS-AIE II; MINI-TAB EDIT, FREQUENCIES, TABLES, REGRESSION, CLIENT RECORD, DATES, MULT, LIFE, and PREGNANCY HISTORY; FIVFIV and SINSIN; DCL (Demographic Computer Library); MINI-TAB Population Projection, Functional Population Projection, and Family Planning Target Projection. A description and evaluation for each program of uses, instruction manuals, computer requirements, and procedures for obtaining manuals and programs are provided. Such information is intended to facilitate and encourage the use of the computer by data processors in developing countries.

  18. Heterogeneity of life histories in a nonhuman primate population

    DEFF Research Database (Denmark)

    Hernández Pacheco, Raisa; Steiner, Uli

    2014-01-01

    histories within a primate population is generated by density-dependent dynamics, the demographic data of Cayo Santiago rhesus macaques over 40 years and 7000 individuals was used. A multi-stage model using a first-order Markov process describing reproductive dynamics was constructed and annual entropy...

  19. Cannabis use and family history in adolescent first episode ...

    African Journals Online (AJOL)

    Objectives: To investigate the clinical correlates of cannabis use in adolescents with first episode psychosis (FEP). Methods: Inpatient psychiatric records provided demographic, lifetime cannabis use, family history of mental illness, and clinical data on 45 FEP adolescents, aged 12–18 years, admitted to a psychiatric unit in ...

  20. Ionic versus nonionic contrast media

    International Nuclear Information System (INIS)

    Zylak, C.J.; Gafni, A.

    1988-01-01

    The efficacy and effectiveness of the nonionic contrast media have been established. Widespread usage has been hampered because of the approximate tenfold increase in cost compared with the ionic media. An economic evaluation considering costs and consequences of both interventions (ionic vs nonionic contrast media) was performed; it is a cost effectiveness (CEA) and a cost-benefit analysis (CBA) for the Canadian experience. The results of the CEA demonstrate a value per life-year saved within an acceptable range when compared with value for quality-adjusted life years for programs such as treatment of severe (diastolic≥ 105 mm Hg) and mild (diastolic 95-104 mm Hg) hypertension in men aged 40. The CBA showed a net cost to society when benefits were measured as future treatment costs saved plus productivity gained. However, if people are willing to pay a small amount for the comfort of the new intervention, this will result in a break-even situation

  1. Contrast-enhanced MR angiography

    International Nuclear Information System (INIS)

    Bosmans, H.; Marchal, G.

    1996-01-01

    Despite many optimizations, the current limitations of plain MR angiography include: Saturation that impairs the visualization of veins and arteries with slow flow and spin-dephasing signal voids in locations with turbulent flow. Recently, the use of contrast agents has been proposed to cope with these remaining problems. Because of induced shortening of the T1 of the blood, saturation in the blood vessels is overcome. As a result, arteries and veins are visualized with the same signal intensity, which makes the technique less flow-dependent. In combination with short T1-weighted acquisitions, today CE MRA can be obtained while the patient is holding his breath. This last approach is most promising for abdominal applications since the respiratory motion can be frozen. As these acquisitions also use very short echo times, spin dephasing can be reduced. In conclusion, the use of contrast agents has greatly increased the clinical usefulness of MR angiography. (orig.) [de

  2. Minimum resolvable power contrast model

    Science.gov (United States)

    Qian, Shuai; Wang, Xia; Zhou, Jingjing

    2018-01-01

    Signal-to-noise ratio and MTF are important indexs to evaluate the performance of optical systems. However,whether they are used alone or joint assessment cannot intuitively describe the overall performance of the system. Therefore, an index is proposed to reflect the comprehensive system performance-Minimum Resolvable Radiation Performance Contrast (MRP) model. MRP is an evaluation model without human eyes. It starts from the radiance of the target and the background, transforms the target and background into the equivalent strips,and considers attenuation of the atmosphere, the optical imaging system, and the detector. Combining with the signal-to-noise ratio and the MTF, the Minimum Resolvable Radiation Performance Contrast is obtained. Finally the detection probability model of MRP is given.

  3. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... is Doing Blog: Public Health Matters Video: "The History of Bioterrorism" Recommend on Facebook Tweet Share Compartir ... as bioterrorist weapons. Watch the Complete Program "The History of Bioterroism" (26 min 38 sec) Watch Specific ...

  4. History of Bioterrorism: Botulism

    Science.gov (United States)

    ... is Doing Blog: Public Health Matters Video: "The History of Bioterrorism" Recommend on Facebook Tweet Share Compartir ... as bioterrorist weapons. Watch the Complete Program "The History of Bioterroism" (26 min 38 sec) Watch Specific ...

  5. "Hillary - en god historie"

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2007-01-01

    Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november......Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november...

  6. Immunologic basis for adverse reactions to radiographic contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Stejskal, V; Nilsson, R; Grepe, A [Astra Pharmaceuticals AB, Soedertaelje (Sweden). Lab. of Safety Assessment Stockholm Univ. (Sweden). Dept. of Genetic and Cellular Toxicology Stockholm Univ. (Sweden). Wallenberglaboratoriet Danderyds Sjukhus, Danderyd (Sweden). Radiologic Clinic

    1990-11-01

    The lymphocyte transformation test (LTT) was used to elucidate whether certain side effects induced by radiographic contrast media have an immunologic etiology. Groups studied were: 8 patients who had previously experienced adverse reactions in association with urography, 6 patients who underwent urography without notable side reactions, 17 occupationally exposed nurses, and 9 unexposed controls. The lymphocytes from 2 hypersensitive patients and from 11 nurses exhibited a positive proliferative response to amidotrizoate. Five nurses who had shown a positive response, had a previous history of hypersensitivity reactions when handling contrast media, whereas the remaining 6 were free of symptoms. Amidotrizoatespecific memory cells were absent in patients who underwent urography without signs of hypersensitivity and in 7/9 of unexposed control subjects. Lymphocytes from patients sensitive to amidotrizoate cross-reacted to structurally related ionic contrast media while nonionic contrast agents did not induce proliferation of the lymphocytes. Thus, ionic radiographic contrast agents have antigenic properties in man. Irradiated mixtures of radiographic contrast media and serum proteins were, in general, not effective in inducing an LTT response. (orig.).

  7. Immunologic basis for adverse reactions to radiographic contrast media

    International Nuclear Information System (INIS)

    Stejskal, V.; Nilsson, R.; Grepe, A.; Stockholm Univ.; Stockholm Univ.; Danderyds Sjukhus, Danderyd

    1990-01-01

    The lymphocyte transformation test (LTT) was used to elucidate whether certain side effects induced by radiographic contrast media have an immunologic etiology. Groups studied were: 8 patients who had previously experienced adverse reactions in association with urography, 6 patients who underwent urography without notable side reactions, 17 occupationally exposed nurses, and 9 unexposed controls. The lymphocytes from 2 hypersensitive patients and from 11 nurses exhibited a positive proliferative response to amidotrizoate. Five nurses who had shown a positive response, had a previous history of hypersensitivity reactions when handling contrast media, whereas the remaining 6 were free of symptoms. Amidotrizoatespecific memory cells were absent in patients who underwent urography without signs of hypersensitivity and in 7/9 of unexposed control subjects. Lymphocytes from patients sensitive to amidotrizoate cross-reacted to structurally related ionic contrast media while nonionic contrast agents did not induce proliferation of the lymphocytes. Thus, ionic radiographic contrast agents have antigenic properties in man. Irradiated mixtures of radiographic contrast media and serum proteins were, in general, not effective in inducing an LTT response. (orig.)

  8. Effects of theophyline on contrast

    OpenAIRE

    A.R. Fatahiyan; B. Baqerii; A. Mohseni; A. Makhlouq

    2006-01-01

    Background and purpose: Contrast-induced nephropathy (CN) is one of the most common causes of iatrogenic acute renal failure. In fact CN is the third leading cause of new ARF in hospitalized patients. Radiocontrast-associated ARF is a significant problem in patients with cardiovascular disease. The risk factors for cardiovascular disease also predispose these patients to an increased risk of renal failure. Various strategies have been suggested for preventing CN. Since adenosine may play a ro...

  9. Demographics of the European apicultural industry.

    Science.gov (United States)

    Chauzat, Marie-Pierre; Cauquil, Laura; Roy, Lise; Franco, Stéphanie; Hendrikx, Pascal; Ribière-Chabert, Magali

    2013-01-01

    Over the last few years, many European and North American countries have reported a high rate of disorders (mortality, dwindling and disappearance) affecting honeybee colonies (Apis mellifera). Although beekeeping has become an increasingly professional activity in recent years, the beekeeping industry remains poorly documented in Europe. The European Union Reference Laboratory for Honeybee Health sent a detailed questionnaire to each Member State, in addition to Kosovo and Norway, to determine the demographics and state of their beekeeping industries. Based on data supplied by the National Reference Laboratory for honeybee diseases in each European country, a European database was created to describe the beekeeping industry including the number and types of beekeepers, operation size, industry production, and health (notifiable diseases, mortalities). The total number of beekeepers in Europe was estimated at 620,000. European honey production was evaluated at around 220,000 tons in 2010. The price of honey varied from 1.5 to 40 €/kg depending on the country and on the distribution network. The estimated colony winter mortality varied from 7 to 28% depending on the country and the origin of the data (institutional survey or beekeeping associations). This survey documents the high heterogeneity of the apicultural industry within the European Union. The high proportion of non-professional beekeepers and the small mean number of colonies per beekeeper were the only common characteristics at European level. The tremendous variation in European apicultural industries has implication for any comprehensive epidemiological or economic analysis of the industry. This variability needs to be taken into account for such analysis as well as for future policy development. The industry would be served if beekeeping registration was uniformly implemented across member states. Better information on the package bee and queen production would help in understanding the ability of

  10. Multiregional demographic projections in practice: a metropolitan example.

    Science.gov (United States)

    Congdon, P

    1992-01-01

    "This paper examines options for local and regional projections which reflect both demographic interdependencies with jobs and housing at this area scale, and the inapplicability of traditional demographic projection methods to population or areal subdivisions. This context for local demographic projections requires constraints (for example, to job and housing forecasts or to higher area totals), the use of proxy or explanatory indicators to predict demographic rates or totals, and parameterization of demographic schedules, to facilitate comparison across numerous localities and to set future assumptions about demographic components. The traditional framework of self-contained projection by deterministic cohort survival is therefore widened to include regio-scientific and stochastic modelling concepts. The framework for empirical analysis is London [England] and its boroughs." (SUMMARY IN FRE AND GER) excerpt

  11. Contrast detail phantom for SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Cabrejas, M.L. de; Arashiro, J G; Giannone, C. [Comision Nacional de Energia Atomica, Buenos Aires (Argentina); Camuyrano, M; Nohara, G [Universidad de Buenos Aires, Buenos Aires (Argentina). Facultad Ciencias Exactas

    1996-06-01

    A new low variable contrast phantom for single photon emission computed tomography (SPECT) was constructed, tested and compared with other existing phantoms. It contains simulated cylindrical lesions of four different diameters (D{sub i}), embedded in a cylindrical scattering medium and a uniform section to evaluate tomographic uniformity. The concentration of tracer in the simulated lesions and the scattering medium (background) can be varied to simulate hot and cold lesions. Different applications of the phantom were tested, including determination of the minimum object contrast (OCm) necessary to detect lesions as a function of lesion size, lesion type (hot or cold) and acquisition and processing protocols by visual inspection. This parameter allows categorization of instruments comparing an `image quality index` (IQI). Preliminary comparison with the Britten contrast processing method showed that the detectable OCm was of the same order of magnitude, but the presented device seems more suitable for training and intercomparison purposes. The constructed phantom, of simple design, has proved to be useful for acquisition and processing condition evaluation, OCm estimation and external quality control. (author). 11 refs, 4 figs.

  12. Advancing High Contrast Adaptive Optics

    Science.gov (United States)

    Ammons, M.; Poyneer, L.; GPI Team

    2014-09-01

    A long-standing challenge has been to directly image faint extrasolar planets adjacent to their host suns, which may be ~1-10 million times brighter than the planet. Several extreme AO systems designed for high-contrast observations have been tested at this point, including SPHERE, Magellan AO, PALM-3000, Project 1640, NICI, and the Gemini Planet Imager (GPI, Macintosh et al. 2014). The GPI is the world's most advanced high-contrast adaptive optics system on an 8-meter telescope for detecting and characterizing planets outside of our solar system. GPI will detect a previously unstudied population of young analogs to the giant planets of our solar system and help determine how planetary systems form. GPI employs a 44x44 woofer-tweeter adaptive optics system with a Shack-Hartmann wavefront sensor operating at 1 kHz. The controller uses Fourier-based reconstruction and modal gains optimized from system telemetry (Poyneer et al. 2005, 2007). GPI has an apodized Lyot coronal graph to suppress diffraction and a near-infrared integral field spectrograph for obtaining planetary spectra. This paper discusses current performance limitations and presents the necessary instrumental modifications and sensitivity calculations for scenarios related to high-contrast observations of non-sidereal targets.

  13. Electrofluidic systems for contrast management

    Science.gov (United States)

    Rebello, Keith J.; Maranchi, Jeffrey P.; Tiffany, Jason E.; Brown, Christopher Y.; Maisano, Adam J.; Hagedon, Matthew A.; Heikenfeld, Jason C.

    2012-06-01

    Operating in dynamic lighting conditions and in greatly varying backgrounds is challenging. Current paints and state-ofthe- art passive adaptive coatings (e.g. photochromics) are not suitable for multi- environment situations. A semi-active, low power, skin is needed that can adapt its reflective properties based on the background environment to minimize contrast through the development and incorporation of suitable pigment materials. Electrofluidic skins are a reflective display technology for electronic ink and paper applications. The technology is similar to that in E Ink but makes use of MEMS based microfluidic structures, instead of simple black and white ink microcapsules dispersed in clear oil. Electrofluidic skin's low power operation and fast switching speeds (~20 ms) are an improvement over current state-ofthe- art contrast management technologies. We report on a microfluidic display which utilizes diffuse pigment dispersion inks to change the contrast of the underlying substrate from 5.8% to 100%. Voltage is applied and an electromechanical pressure is used to pull a pigment dispersion based ink from a hydrophobic coated reservoir into a hydrophobic coated surface channel. When no voltage is applied, the Young-Laplace pressure pushes the pigment dispersion ink back down into the reservoir. This allows the pixel to switch from the on and off state by balancing the two pressures. Taking a systems engineering approach from the beginning of development has enabled the technology to be integrated into larger systems.

  14. Invader population speeds up life history during colonization

    OpenAIRE

    Amundsen, Per-Arne; Salonen, Erno; Niva, Teuvo; Gjelland, Karl Øystein; Præbel, Kim; Sandlund, Odd Terje; Knudsen, Rune; Bøhn, Thomas

    2012-01-01

    We explore the long-term developments in population biology and life history during the invasion and establishment of the fish species vendace Coregonus albula in a subarctic watercourse by comparing life-history traits and molecular genetic estimates between the source and the colonist population. The two populations exhibited highly contrasting life-history strategies. Relative to the source population, the colonist population was characterized by slower somatic growth rates, earlier sexual...

  15. Canadian petroleum history bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Cass, D.

    2003-09-27

    The Petroleum History Bibliography includes a list of more than 2,000 publications that record the history of the Canadian petroleum industry. The list includes books, theses, films, audio tapes, published articles, company histories, biographies, autobiographies, fiction, poetry, humour, and an author index. It was created over a period of several years to help with projects at the Petroleum History Society. It is an ongoing piece of work, and as such, invites comments and additions.

  16. Late adverse reactions to intravascular iodine based contrast media

    DEFF Research Database (Denmark)

    Bellin, Marie-France; Stacul, Fulvio; Webb, Judith A W

    2011-01-01

    DEFINITION: Late adverse reactions (LAR) to contrast media (CM) are defined as reactions occurring 1 h to 1 week after exposure. NEED FOR REVIEW: In view of more prospective studies of LAR and new data about their pathophysiology, the Contrast Medium Safety Committee (CMSC) of the European Society...... or delayed reading intradermal). The main risk factors for LAR are a previous reaction to contrast medium, a history of allergy, and interleukin-2 treatment. Most skin reactions are mild or moderate and self-limiting. MANAGEMENT: Management is symptomatic and similar to the management of other drug......-induced skin reactions. To reduce the risk of repeat reactions avoidance of the relevant CM and any cross-reacting agents identified by skin testing is recommended....

  17. Demographic Composition of the Online Buyers in Turkey

    OpenAIRE

    Sinan NARDALI

    2011-01-01

    Demographic variables may have an impact on Internet usage patterns. Online buyers’ characteristics keeps changing time along with the shifting dynamics of Turkish consumers’ demographic profile and day by day online shopping becomes a safe and popular option in Turkey. Current study investigates demographic composition of the online buyers that influence consumer attitudes towards online shopping behavior in Izmir, the third largest city in Turkey. This study examines attitudes toward online...

  18. Diet History Questionnaire: Database Revision History

    Science.gov (United States)

    The following details all additions and revisions made to the DHQ nutrient and food database. This revision history is provided as a reference for investigators who may have performed analyses with a previous release of the database.

  19. History of Science and History of Philologies.

    Science.gov (United States)

    Daston, Lorraine; Most, Glenn W

    2015-06-01

    While both the sciences and the humanities, as currently defined, may be too heterogeneous to be encompassed within a unified historical framework, there is good reason to believe that the history of science and the history of philologies both have much to gain by joining forces. This collaboration has already yielded striking results in the case of the history of science and humanist learning in early modern Europe. This essay argues that first, philology and at least some of the sciences (e.g., astronomy) remained intertwined in consequential ways well into the modern period in Western cultures; and second, widening the scope of inquiry to include other philological traditions in non-Western cultures offers rich possibilities for a comparative history of learned practices. The focus on practices is key; by shifting the emphasis from what is studied to how it is studied, deep commonalities emerge among disciplines--and intellectual traditions--now classified as disparate.

  20. Modern History of Tibet

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    Authored by Xu Guangzhi, this book is a subsidiary project of Research Into Traditional Culture and History (of the PRC Ministry of Education) conducted by China Tibetology Research Institute of Tibet University. The book combines modern history of Tibet with modern history of China as a whole. It tells the close ties between various members of the Chinese nation.

  1. History of Particle Physics

    Science.gov (United States)

    back to history page Back Particle Physics Timeline For over two thousand years people have thought the Standard Model. We invite you to explore this history of particle physics with a focus on the : Quantum Theory 1964 - Present: The Modern View (the Standard Model) back to history page Back Sections of

  2. Teaching Women's History.

    Science.gov (United States)

    Fain, George

    1995-01-01

    Argues that women's history should stress the broad sociological view of women's roles not only in politics but in mundane, day-to-day life throughout all of history, rather that reducing women's history to a few token figures. Notes that many college and secondary texts and testing materials have recognized the trend toward the inclusion of…

  3. Towards Household History

    NARCIS (Netherlands)

    van Rappard, J.F.H.

    1998-01-01

    It is maintained that in contradistinction to the natural sciences, in psychology (and other human sciences) ‘history is not past tense’. This is borne out by the contemporary relevance of a specific part of the history of psychology, which focuses on the internal-theoretical significance of history

  4. Film and History.

    Science.gov (United States)

    Schaber, Robin L.

    2002-01-01

    Provides an annotated bibliography of Web sites that focus on using film to teach history. Includes Web sites in five areas: (1) film and education; (2) history of cinema; (3) film and history resources; (4) film and women; and (5) film organizations. (CMK)

  5. A population-based longitudinal study on the implication of demographic changes on blood donation and transfusion demand.

    Science.gov (United States)

    Greinacher, Andreas; Weitmann, Kerstin; Schönborn, Linda; Alpen, Ulf; Gloger, Doris; Stangenberg, Wolfgang; Stüpmann, Kerstin; Greger, Nico; Kiefel, Volker; Hoffmann, Wolfgang

    2017-06-13

    Transfusion safety includes the risk of transmission of pathogens, appropriate transfusion thresholds, and sufficient blood supply. All industrialized countries experience major ongoing demographic changes resulting from low birth rates and aging of the baby boom generation. Little evidence exists about whether future blood supply and demand correlate with these demographic changes. The ≥50% decline in birth rate in the eastern part of Germany after 1990 facilitates systematic study of the effects of pronounced demographic changes on blood donation and demand. In this prospective, 10-year longitudinal study, we enrolled all whole blood donors and all patients receiving red blood cell transfusions in the state of Mecklenburg-West Pomerania. We compared projections made in 2005 based on the projected demographic changes with: (1) number and age distribution of blood donors and transfusion recipients in 2015 and (2) blood demand within specific age and patient groups. Blood donation rates closely followed the demographic changes, showing a decrease of -18% (vs projected -23%). In contrast, 2015 transfusion rates were -21.3% lower than projected. We conclude that although changes in demography are highly predictive for the blood supply, transfusion demand is strongly influenced by changes in medical practice. Given ongoing pronounced demographic change, regular monitoring of the donor/recipient age distributions and associated impact on blood demand/supply relationships is required to allow strategic planning to prevent blood shortages or overproduction.

  6. Demographic Characteristics of Our Patients with Carpal Tunnel Syndrome

    Directory of Open Access Journals (Sweden)

    Ebru Umay

    2011-09-01

    Full Text Available Aim: Carpal tunnel (CTS is the most common trap neuropathy but, still fully understood the cause of this and effective factors. In this study was aimed to the evaluation demographic features of the cases with CTS admitted to our electroneuromyography (ENMG laboratory. Material and Methods: In the study, 119 patients with CTS to evaluate our ENMG laboratory were received. All patients age, sex, dominant and affected hand, duration of education, marital status, height, weight, additional diseases, occupational, hand and wrist repetitive motion made, use of computer and smoking status was assessed. Patients’ body mass index (BMI was calculated. Results: 102 cases (85.7% females, mean age was 46.32 years ± 12: 18. While in 115 (96.6% cases using the right hand is dominant, in 85 cases (76.6% with bilateral involvement were at hand. While the rate of patient who between five to eight year duration of education had was 47.1%, 84% patients were married. Also, BMI were determined as 29.33± 3.01. According to the state in 22 patients with additional diseases, diabetes mellitus in 22, hypothyroidism in 4, also 1 patient had arthritis. The majority of our patients (70.6% housewives formed. The 67.2% rate of repetetive activities as making crafts, the computer usage at a rate of 11.8% had history. The rate of smoking was 19.3%.  Conclusions:  As a result, CTS, especially in middle-aged housewives and obese is a common syndrome. Despite many reasons to be reported in the etiology of idiopathic 85%. At a rate of 25.4% of women in our society is considered paid work, especially in terms of determining the etiology of the more detailed studies are needed to ousewives.

  7. The Retrospective Evaluation of Childhood Psoriasis Clinically and Demographic Features

    Directory of Open Access Journals (Sweden)

    Ayşe Serap Karadağ

    2013-03-01

    Full Text Available Objective: This study was aimed to define the clinical and demographic findings of psoriasis in childhood. Methods: In this retrospective study, the data from 64 children with psoriasis admitted at the our dermatology clinic between January 2007 and January 2011 were included whose data were fully. Results: Of the patients, 37 (57.8% were boys and 27 (42.2% were girls. Mean age of the children was 10.08 ±3.98 years (3-16. In 10 (15% cases, a positive family history was detected. The most frequent localizations at onset were trunk (46.9%, scalp (28.1%, knee-elbow (10.9% and extremities (7.9%, respectively. The most commonly seen clinical types were plaque (68.8%, guttate (20.3%, palmoplantar (9.4%, pustular (1.6%, respectively. Nine children had nail involvement. Out of all patients, 21.9% had upper respiratory tract infections and 9.4% had emotional stres. Four cases were diagnosed with depression. Of the cases, two cases were on non-steroid anti-inflammatory medication, and 4 of them were on antibiotics. Systemic treatments were given to 21.9% of the cases besides topical treatments. Conclusion: The epidemiological studies of psoriasis during childhood period for different countries have been reported. In this study, the ratio shows differences when compared to those previous studies. There are few epidemiologic studies for Turkey. We believe that further epidemiological studies including large number of patients' groups will contribute the diagnosis and treatment of the disease.

  8. History of mathematics and history of science

    OpenAIRE

    Mann, Tony

    2011-01-01

    This essay argues that the diversity of the history of mathematics community in the United Kingdom has influenced the development of the subject and is a significant factor behind the different concerns often evident in work on the history of mathematics when compared with that of historians of science. The heterogeneous nature of the community, which includes many who are not specialist historians, and the limited opportunities for academic\\ud careers open to practitioners have had a profoun...

  9. Dissemination and geovisualization of territorial entities' history

    Directory of Open Access Journals (Sweden)

    Christine Plumejeaud

    2014-06-01

    Full Text Available This paper describes an innovative solution for geovisualization of the demographic and administrative history of French municipalities, named "communes" in French. This solution allows for the open dissemination of such data. The challenge is to provide a web interface for unskilled users in order to help them understand complex information about the demographic evolution of French territories. Our approach combines interactive thematic, spatial, and temporal views. We describe our architecture, based on open-source technologies, and the organization of this imperfect geo-historical information in our spatiotemporal database. Our second contribution concerns the concept of an acquaintance graph that has been used to obtain an efficient design with good performance in our geovisualization website.

  10. Bowel Angioedema Associated With Iodinated Contrast Media: Incidence and Predisposing Factors.

    Science.gov (United States)

    Seo, Nieun; Chung, Yong Eun; Lim, Joon Seok; Song, Mi Kyung; Kim, Myeong-Jin; Kim, Ki Whang

    2017-09-01

    Bowel angioedema is an acute adverse reaction to iodinated contrast media (CM) that involves the gastrointestinal tract. We aimed to investigate the incidence and predisposing factors of iodinated CM-associated bowel angioedema during computed tomography (CT) examinations. This study was approved by our institutional review board, and informed consent was waived due to its retrospective design. From July 2013 to July 2015, adult patients with a history of adverse reactions to iodinated CM during CT (group A, n = 427) and patients without adverse reactions matched for age and sex with the propensity-score matching method (group B, n = 427) were studied. Contrast media-associated bowel angioedema was determined when bowel wall thickness increased after contrast enhancement compared with the precontrast scan. Potential predisposing factors including patient demographics, symptoms and time of adverse reactions, and CM-related factors were compared between patients with and without angioedema in group A. In addition, the incidence of bowel angioedema was compared between groups A and B. The incidence of CM-associated bowel angioedema in group A was 3.3% (14/427) in the per-patient analysis and 2.6% (15/578) in the per-examination analysis. The CM-associated bowel angioedema involved the distal duodenum and/or proximal jejunum and showed long-segmental circumferential bowel wall thickening on CT. None of the studied predisposing factors was different between patients with and without bowel angioedema (P > 0.05). The incidence of CM-associated bowel angioedema in group B was 1.9% (8/427) and 1.7% (8/458) for per-patient and per-examination analyses, respectively, and these rates were not significantly different between groups A and B (P = 0.346 and P = 0.370, respectively). The incidence of CM-associated bowel angioedema during CT was 1.7% to 3.3%, and none of the studied predisposing factors was associated with bowel angioedema.

  11. World History Workshop (1983).

    Science.gov (United States)

    1984-10-01

    history appeared tenuous. While the study of American history was viewed as necessary to "indoctrinate kids ," world history is unable to make such a...world" which is hard to avoid in world history, where one examines China in 1500, China in 1800, and so on. A pedagogical goal in the new course was to...the historian to make intelligent decisions about what information he is going to talk about. Viewing world history as a scenario also has a pedagogic

  12. MEAT GOAT DEMOGRAPHICS AND NICHE MARKETING

    Directory of Open Access Journals (Sweden)

    Jeffrey Fisher

    2009-06-01

    Full Text Available Six focus groups were conducted with each having ten people who attend different Islamic Centers in Ohio. The objective of the focus groups was to understand Halal meat purchase patterns and consumption patterns of the Moslem population with special attention to goat. The Ohio State University Extension personnel are utilizing these results to work with meat goat producers to understand and meet the requirements of the Halal meat market.  Participants discussed the Zabiha approach to slaughtering animals as the most merciful by causing the least pain. Many participants noted they had no way of knowing where the animal  came from and this held tremendous concerns relative to the feeding of animal by-products, use of hormones, and adulteration with pork. These trust concerns led to decisions about where to purchase their meat with 72% purchasing from a Moslem owned retail store. Only 13% purchased from a large grocery and 8% direct from a farmer.   Participants indicated their consumption patterns according to weekly, seasonal, and holiday use in addition to variations according to their personal geographic origin. The average meat purchase was 23 pounds with an average occurrence of 12.5 times per annum.  Purchasing trends indicated that 78% prefer lean over marbled cuts. Nearly 86% prefer fresh over frozen goat meat and nearly a third responded that they would pay more for fresh. Intact males were preferred by 42% of the respondents. Preferences for meat goat cuts were: Leg (71%, Chops (42%, Shoulder (24%, Breast (7%. Nearly a third indicated they also want the kidneys, heart, or head. Demographic shifts in the United States indicate that there are almost 53 million people who have a preference for goat meat. There are 2.4 million goats in the US according to the 2007 Agricultural Statistics. Based on consumption trends of this study, goat demand exceeds inventory by 160%. Meat goat consumer trends are changing regarding

  13. Demographic upheavals in the former USSR.

    Science.gov (United States)

    Haub, C

    1995-01-01

    Fertility and life expectancy have changed since the breakup of the Soviet republics in 1991 and continue to change very rapidly. Before 1991, the USSR was the fastest growing developed country in the world. Annual growth rates in the mid-1980s were 0.9% compared to only 0.1% in Europe or 1.1% in the US. Immigration did not greatly affect the USSR's growth rate. By 1993, the population had declined in 8 of the 15 former republics. Deaths exceeded births in Russia, Belarus, Ukraine, Estonia, and Latvia, followed by Lithuania in 1994. The last census was conducted in 1989. Fertility declined in Russia from 1.9 in 1990 to 1.4 in 1993. Fertility has been low in Lithuania at 1.7, in the Ukraine at 1.6, in Latvia at 1.5, and in Estonia at 1.4. Kazakhstan, Georgia, and Kyrgyzstan have experienced fertility decline, which was affected by emigration to Russia and other countries after 1990. 25 million Russians have resided in the former republics in 1990. In Kazakhstan, the 160,000 more births than deaths were offset by 200,000 emigrants. Central republics with higher fertility experienced declines after 1990; for example, Kyrgyzstan declined from 3.7 in 1990 to 3.3 in 1993. Life expectancy for males in Russia in 1993 was 58.9 years, which was a decline from 63.8 years in 1990. About 50% of the decline in life expectancy was due to circulatory diseases, and about 25% was due to external causes such as accidents, suicide, and alcoholism. Infant mortality has been increasing since 1990; for example, it increased in the Ukraine from 12.9 in 1990 to 14.1 in 1992. Russia's population in 1993 experienced 700,000 more deaths than births. The demographic impact will be declining school enrollments and smaller employment among the working population to support the aged. The change to a market economy has been uneven in Russia, where it has advanced more rapidly than in the republics. It is unclear whether the declining birth rate and increasing mortality rates will continue, but

  14. A prospective study on the risk of contrast induced nephropathy in the patients who underwent contrast-enhanced CT examination

    International Nuclear Information System (INIS)

    Zhang Baocui; Zhang Yudong; Zhao Kai; Wang Xiaoying; Jiang Xuexiang

    2013-01-01

    Objective: To investigate the incidence of contrast induced nephropathy (CIN) among different patient groups after contrast agent injection. Methods: A total of 1243 patients were included in this study (male = 694, female = 549). The SCr level one week before and 72 hours after the CT examination and the incidence of CIN were recorded and comparison was made among groups according to sex, age, body mass index (BMI), the history of high blood pressure (HBP), diabetes mellitus (DM), chronic kidney disease (CKD), chronic heart failure (CHF), tumor, nephrotoxicity drug (NTD) usage. The frequency, type, dose and injection velocity of the contrast media (CM) were also recorded. Multivariate predictors of CIN were identified by Logistic regression using step-wise selection with entry and exit criteria of P 1). Conclusion: Women, age ≥ 75 years, LOCM, NTD, tumor, and the frequency of using CM more than once per month were more likely to develop CIN. (authors)

  15. Mellem historie- og krigsvidenskab

    DEFF Research Database (Denmark)

    Hansen Schøning, Anna Sofie

    2016-01-01

    history was used to establish national and organisational identity. In the 1880s, military history was used as a means to find, explain and apply universal principles of war and, in the 1910s, military history should be used as a means to gain general insight that could potentially lead to a better......The article investigates how military history was taught as part of the Danish higher officer education from 1830 to 1920 and how the subject was affected by developments in academic history and the science of war. It argues that military history, as it was taught in the formal officer education......, could not be seen solely as a historic subject but also as a subject under the influence of the discipline of military science. Three very different understandings of how military history can contribute to higher officer education are shown through the analysis of textbooks. In the 1830s military...

  16. Three concepts of history

    Directory of Open Access Journals (Sweden)

    Antonio Campillo

    2016-05-01

    Full Text Available The aim of this article is twofold. On the one hand, I will outline the diverse usages that the concept of history has taken on throughout Western history. These different usages may be grouped together in three semantic fields (history as a way of knowing, as a way of being and as a way of doing, which correspond to three ways of understanding the Philosophy of History: as Epistemology of History, as Ontology of historicity and as ethical-political Critique of the present. On the other hand, I will show that these three concepts of history (and, accordingly, the three ways of understanding the Philosophy of History refer mutually to each other and, thus, are inseparable from each other.

  17. Inferences of Recent and Ancient Human Population History Using Genetic and Non-Genetic Data

    Science.gov (United States)

    Kitchen, Andrew

    2008-01-01

    I have adopted complementary approaches to inferring human demographic history utilizing human and non-human genetic data as well as cultural data. These complementary approaches form an interdisciplinary perspective that allows one to make inferences of human history at varying timescales, from the events that occurred tens of thousands of years…

  18. Health & demographic surveillance system profile: the Nahuche Health and Demographic Surveillance System, Northern Nigeria (Nahuche HDSS).

    Science.gov (United States)

    Alabi, Olatunji; Doctor, Henry V; Jumare, Abdulazeez; Sahabi, Nasiru; Abdulwahab, Ahmad; Findley, Sally E; Abubakar, Sani D

    2014-12-01

    The Nahuche Health and Demographic Surveillance System (HDSS) study site, established in 2009 with 137 823 individuals is located in Zamfara State, north western Nigeria. North-West Nigeria is a region with one of the worst maternal and child health indicators in Nigeria. For example, the 2013 Nigeria Demographic and Health Survey estimated an under-five mortality rate of 185 deaths per 1000 live births for the north-west geo-political zone compared with a national average of 128 deaths per 1000 live births. The site comprises over 100 villages under the leadership of six district heads. Virtually all the residents of the catchment population are Hausa by ethnicity. After a baseline census in 2010, regular update rounds of data collection are conducted every 6 months. Data collection on births, deaths, migration events, pregnancies, marriages and marriage termination events are routinely conducted. Verbal autopsy (VA) data are collected on all deaths reported during routine data collection. Annual update data on antenatal care and household characteristics are also collected. Opportunities for collaborations are available at Nahuche HDSS. The Director of Nahuche HDSS, M.O. Oche at [ochedr@hotmail.com] is the contact person for all forms of collaboration. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  19. Health & Demographic Surveillance System profile: the Muzaffarpur-TMRC Health and Demographic Surveillance System.

    Science.gov (United States)

    Malaviya, Paritosh; Picado, Albert; Hasker, Epco; Ostyn, Bart; Kansal, Sangeeta; Singh, Rudra Pratap; Shankar, Ravi; Boelaert, Marleen; Sundar, Shyam

    2014-10-01

    The Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS), established in 2007, was developed as an enlargement of the scope of a research collaboration on the project Visceral Leishmaniasis in Bihar, which had been ongoing since 2005. The HDSS is located in a visceral leishmaniasis (VL)-endemic area in the Muzaffarpur district of Bihar state in India. It is the only HDSS conducting research on VL, which is a vector-borne infectious disease transmitted by female phlebotomine sandflies and is fatal if left untreated. Currently the HDSS serves a population of over 105,000 in 66 villages. The HDSS collects data on vital events including pregnancies, births, deaths, migration and marriages, as well as other socio-economic indicators, at regular intervals. Incident VL cases are identified. The HDSS team is experienced in conducting both qualitative and quantitative studies, sample collection and rapid diagnostic tests in the field. In each village, volunteers connect the HDSS team with the community members. The Muzaffarpur-TMRC HDSS provides opportunities for studies on VL and other neglected tropical diseases (NTDs) and their interaction with demographic events such as migration. Queries related to research collaborations and data sharing can be sent to Dr Shyam Sundar at [drshyamsundar@hotmail.com]. © The Author 2014; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association.

  20. Phase contrast STEM for thin samples: Integrated differential phase contrast.

    Science.gov (United States)

    Lazić, Ivan; Bosch, Eric G T; Lazar, Sorin

    2016-01-01

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). Copyright © 2015 Elsevier B.V. All rights reserved.

  1. What is on a demographer's mind?: a worldwide survey

    NARCIS (Netherlands)

    van Dalen, H.P.; Henkens, K.

    2012-01-01

    Background: Over the years, the community of demographers has grown in numbers and research interests, and has become increasingly interdisciplinary. The question is whether this process of growth and diversity has led to a fragmented community of demographers. Objective: We examine whether or not

  2. What is on a demographer's mind? : A worldwide survey

    NARCIS (Netherlands)

    van Dalen, H.P.; Henkens, C.J.I.M.

    2012-01-01

    BACKGROUND Over the years, the community of demographers has grown in numbers and research interests, and has become increasingly interdisciplinary. The question is whether this process of growth and diversity has led to a fragmented community of demographers. OBJECTIVE We examine whether or not

  3. Implications of research staff demographics for psychological science.

    Science.gov (United States)

    Does, Serena; Ellemers, Naomi; Dovidio, John F; Norman, Jasmine B; Mentovich, Avital; van der Lee, Romy; Goff, Phillip Atiba

    2018-03-01

    Long-standing research traditions in psychology have established the fundamental impact of social categories, such as race and gender, on people's perceptions of themselves and others, as well as on the general human cognition and behavior. However, there is a general tendency to ignore research staff demographics (e.g., researchers' race and gender) in research development and research reports. Variation in research staff demographics can exert systematic and scientifically informative influences on results from psychological research. Consequently, research staff demographics need to be considered, studied, and/or reported, along with how these demographics were allowed to vary across participants or conditions (e.g., random assignment, matched with participant demographics, or included as a factor in the experimental design). In addition to providing an overview of multidisciplinary evidence of research staff demographics effects, we discuss how research staff demographics might influence research findings through (a) ingroup versus outgroup effects, (b) stereotype and (implicit) bias effects, and (c) priming and social tuning effects. Finally, an overview of recommended considerations is included (see the Appendix) to help illustrate how to systematically incorporate relevant research staff demographics in psychological science. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  4. [Some unique characteristics of the demographic situation in Russia].

    Science.gov (United States)

    Brui, B; Mikhailov, E

    1991-01-01

    The authors briefly describe the demographic situation in the Russian Soviet Federated Socialist Republic, using data from the 1989 census and current demographic research. Changes in the birth rate and population growth are examined, and migration flows in the various regions of the republic are compared. Factors affecting low birth rates are analyzed, and trends in marriage, divorce, mortality, and life expectancy are explored.

  5. Epidemiological and demographic HIV/AIDS projections: South Africa

    African Journals Online (AJOL)

    Epidemiological and demographic HIV/AIDS projections: South Africa. ... African Journal of AIDS Research ... Projections and the Spectrum model program developed by the Futures Group were used to model the South African HIV epidemic, project future trends in HIV/AIDS and estimate the demographic impact of AIDS.

  6. Developing a Global Mindset: Integrating Demographics, Sustainability, Technology, and Globalization

    Science.gov (United States)

    Aggarwal, Raj

    2011-01-01

    Business schools face a number of challenges in responding to the business influences of demographics, sustainability, and technology--all three of which are also the fundamental driving forces for globalization. Demographic forces are creating global imbalances in worker populations and in government finances; the world economy faces…

  7. Relating plant height to demographic rates and extinction vulnerability

    NARCIS (Netherlands)

    Jonge, de Melinda M.J.; Hilbers, Jelle P.; Jongejans, Eelke; Ozinga, Wim A.; Hendriks, A.J.; Huijbregts, Mark A.J.

    2018-01-01

    To prioritize conservation efforts, it is important to know which plant species are most vulnerable to extinction. Intrinsic extinction vulnerabilities depend on demographic parameters, but for many species these demographic parameters are lacking. Body size has been successfully used as proxy of

  8. Optimal demographic information for policy development in the ...

    African Journals Online (AJOL)

    After ten years of a democratic education system in South Africa , the demographic realities should be better understood in educational planning. The fragmented nature of the predemocratic education system has led to undesirable perceptions about quality education and has subsequently influenced the demographic ...

  9. Implications of Demographic Change for the Design of Retirement Programs.

    Science.gov (United States)

    Biggs, John H.

    1994-01-01

    The influences that demographic changes may have on the design of private pension plans in the twenty-first century are examined. Major demographic factors to be considered include the aging of the population, declining mortality rate, potential for an even lower mortality rate, improved health for all ages and especially for older workers, and…

  10. Making the Case for Demographic Data in Extension Programming

    Science.gov (United States)

    Curtis, Katherine J.; Verdoff, Daniel; Rizzo, Bill; Beaudoin, James

    2012-01-01

    Understanding one's community is essential for effective Extension programming across all program areas. The use of current and reliable demographic data is crucial for Extension to develop effective education and programming to track change and to uncover hidden community characteristics. We discuss what demographic data are, present…

  11. The Impact Of Demographic Factors On Organisational Commitment ...

    African Journals Online (AJOL)

    The Study Investigated the Impact of demographic factors on organization commitment among workers in selected work organizations in Lagos State of Nigeria. This was for the purpose of ascertaining the relevance of demographic factors on workers' commitment to organizations goal achievement in Nigeria. The ex-post ...

  12. Radiographic contrast media, function and future reassessed

    International Nuclear Information System (INIS)

    Sovak, M.

    1988-01-01

    A brief review is given of the use of radiographic contrast media in cholecysto- and cholangiography, central nervous system imaging, urography and angiography. Other aspects briefly discussed are the use of large i.v. doses of contrast media for CT contrast enhancement and the design theory for improved water soluble contrast media. (U.K.)

  13. TEENAGE PREGNANCY: DEMOGRAPHICS, MATERNAL AND FOETAL OUTCOME

    Directory of Open Access Journals (Sweden)

    Radhika Gollapudi

    2016-08-01

    Full Text Available BACKGROUND Pregnancy though is a physiological event in a woman’s life, it has its own associated complications. In teenage pregnancies, the physical and emotional state of stress coupled with biological immaturity leads to adverse effect both on the health of the mother and the foetus. METHODS This study is a clinical prospective study analysing the demographics, maternal health issues and the foetal outcome in teenage pregnancies. The study was conducted over a period of one year at a government tertiary care center. Pregnant women in the age group of 13-19 years who delivered during the study period were included in the study group. All pregnant women over 20 years of age who delivered during the same period were taken as control group. Women who had medical disorders complicating pregnancy were excluded from the study. Anaemia, pregnancy induced hypertension, antepartum haemorrhage and mode of delivery were the maternal outcomes that were noted. Intrauterine growth retardation, prematurity, low birth weight, APGAR score were analysed with respect to the foetus. RESULTS In this study, the total number of pregnant women who delivered during the study period were 4782, 536 were teenage mothers, constituting 11.2% of the total pregnancies. Of the 536 teenage mothers, 69.78% belonged to the rural areas and 71.64% were found to have inadequate antenatal visits to the hospital. The mean age of teenage pregnancy was 17.18 years. Incidence of anaemia was 44.2% in comparison, the control group had an incidence of 33.02%. In our study, incidence of Pregnancy induced hypertension was 18.64% in teenage mothers and 10.6% in non-teenage mothers. The incidence of Antepartum Haemorrhage in our study was 8.94% in teenage mothers. Incidence of lower segment caesarean section was 22.76% in the teenage group as compared to 14.57% in the non-teenage group. In our study, 13.05% of teenage mothers had preterm deliveries as compared to 6.40% of non-teenage mothers

  14. History of mathematics and history of science.

    Science.gov (United States)

    Mann, Tony

    2011-09-01

    This essay argues that the diversity of the history of mathematics community in the United Kingdom has influenced the development of the subject and is a significant factor behind the different concerns often evident in work on the history of mathematics when compared with that of historians of science. The heterogeneous nature of the community, which includes many who are not specialist historians, and the limited opportunities for academic careers open to practitioners have had a profound effect on the discipline, leading to a focus on elite mathematics and great mathematicians. More recently, reflecting earlier developments in the history of science, an increased interest in the context and culture of the practice of mathematics has become evident.

  15. The teaching of history through histories

    Directory of Open Access Journals (Sweden)

    María Gabriela Calvas-Ojeda

    2017-12-01

    Full Text Available The comic strips have been introduced into the world of history as a didactic resource for their learning; However, there are still shortcomings in their use by teachers, motivated on many occasions due to lack of knowledge and insufficient methodological preparation; The purpose of this work is to socialize knowledge related to these didactic resources to contribute to the didactic-methodological enrichment of the teacher, in order to change this attitude. The methodological strategy responds to the quantitative-qualitative paradigm; in the collection of the information a participant observation guide was used to the history classes and interview to a sample of 9 teachers of Third Degree of the schools of the city of Machala randomly selected. We recorded the observations of the knowledge acquired by the 98 students who received the classes mediated by comic strips, which allowed us to conclude that comics for the teaching and learning of History constitute a powerful didactic resource.

  16. PHENOTYPIC DIFFERENTIATION AT SOUTHERN LIMIT BORDERS: THE CASE STUDY OF TWO FUCOID MACROALGAL SPECIES WITH DIFFERENT LIFE-HISTORY TRAITS1.

    Science.gov (United States)

    Araújo, Rita; Serrão, Ester A; Sousa-Pinto, Isabel; Åberg, Per

    2011-06-01

    Marginal populations are often geographically isolated, smaller, and more fragmented than central populations and may frequently have to face suboptimal local environmental conditions. Persistence of these populations frequently involves the development of adaptive traits at phenotypic and genetic levels. We compared population structure and demographic variables in two fucoid macroalgal species contrasting in patterns of genetic diversity and phenotypic plasticity at their southern distribution limit with a more central location. Models were Ascophyllum nodosum (L.) Le Jol. (whose extreme longevity and generation overlap may buffer genetic loss by drift) and Fucus serratus L. (with low genetic diversity at southern margins). At edge locations, both species exhibited trends in life-history traits compatible with population persistence but by using different mechanisms. Marginal populations of A. nodosum had higher reproductive output in spite of similar mortality rates at all life stages, making edge populations denser and with smaller individuals. In F. serratus, rather than demographic changes, marginal populations differed in habitat, occurring restricted to a narrower vertical habitat range. We conclude that persistence of both A. nodosum and F. serratus at the southern-edge locations depends on different strategies. Marginal population persistence in A. nodosum relies on a differentiation in life-history traits, whereas F. serratus, putatively poorer in evolvability potential, is restricted to a narrower vertical range at border locations. These results contribute to the general understanding of mechanisms that lead to population persistence at distributional limits and to predict population resilience under a scenario of environmental change. © 2011 Phycological Society of America.

  17. Ultrasound contrast agents: an overview.

    Science.gov (United States)

    Cosgrove, David

    2006-12-01

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MIdeveloped for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating vasospasm after subarachnoid haemorrhage). An important situation where demonstrating tissue devitalisation is important is in interstitial ablation of focal liver lesions: using microbubble contrast agents at the end of a procedure allows immediate evaluation of the

  18. Optimising the diagnostic imaging process through clinical history documentation

    International Nuclear Information System (INIS)

    Egan, I.; Baird, M.

    2003-01-01

    In the United Kingdom the 1990s were characterised by radiographer role extension including radiographic reporting and the performance of a variety of contrast examinations. In Australia where a privatised health system constrains the role of radiographers, other ways need to be found to improve professional practice and enhance patient care. One such way is for radiographers to develop knowledge and skills in clinical history taking. The paper advocates the development of a formalised approach to clinical history taking that portrays the radiographer as a professional and advocate of patient rights and welfare. The paper examines history taking approaches used by other health care professionals and proposes a clinical history template using five key areas of interview: area and type of symptoms, current history, past history, special considerations and psychosocial/occupational history. Copyright (2003) Australian Institute of Radiography

  19. A case report on a severe anaphylaxis reaction to Gadolinium-based MR contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Park, Juil; Kim, Tae Hyung; Park, Chang Min; Yoon, Soon Ho; Lee, Whal; Kang, Hye Ryun; Choi, Young Hun [Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-02-15

    Acute hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast media have been shown to have a much lower incidence and they are generally milder in terms of severity than acute adverse reactions associated with the use of iodinated contrast media for computed tomography scans. However, even though it is rare, a severe hypersensitivity reaction to MR contrast media can occur. Here we present the case of a 66-year-old woman who experienced a severe hypersensitivity reaction after administration of gadolinium-based contrast media without a previous history of allergies.

  20. Marine Environmental History

    DEFF Research Database (Denmark)

    Poulsen, Bo

    2012-01-01

    human society and natural marine resources. Within this broad topic, several trends and objectives are discernable. The essay argue that the so-called material marine environmental history has its main focus on trying to reconstruct the presence, development and environmental impact of past fisheries......This essay provides an overview of recent trends in the historiography of marine environmental history, a sub-field of environmental history which has grown tremendously in scope and size over the last c. 15 years. The object of marine environmental history is the changing relationship between...... and whaling operations. This ambition often entails a reconstruction also of how marine life has changed over time. The time frame rages from Paleolithicum to the present era. The field of marine environmental history also includes a more culturally oriented environmental history, which mainly has come...

  1. Ranking economic history journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    2010-01-01

    This study ranks-for the first time-12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We also...... compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential for economic...... history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

  2. Ranking Economic History Journals

    DEFF Research Database (Denmark)

    Di Vaio, Gianfranco; Weisdorf, Jacob Louis

    This study ranks - for the first time - 12 international academic journals that have economic history as their main topic. The ranking is based on data collected for the year 2007. Journals are ranked using standard citation analysis where we adjust for age, size and self-citation of journals. We...... also compare the leading economic history journals with the leading journals in economics in order to measure the influence on economics of economic history, and vice versa. With a few exceptions, our results confirm the general idea about what economic history journals are the most influential...... for economic history, and that, although economic history is quite independent from economics as a whole, knowledge exchange between the two fields is indeed going on....

  3. Clinical applications of contrast echocardiography

    International Nuclear Information System (INIS)

    Jorge, Leon Galindo

    2005-01-01

    The echocardiography is the technique more used for the diagnosis and pursuit of the cardiovascular illnesses; therefore, their diagnostic precision has acquired a vital importance in the handling of the patients with cardiovascular pathologies. However, with relative frequency, the diagnostic capacity of the echocardiography exam is diminished by limitations of the acoustic window, mainly in-patient with obesity, lung illnesses and alterations of the thoracic wall. This can be obviated with the use of the intra-esophagus echocardiography, although this it is a procedure semi-invasive and not very practical of carrying out in all the patients with problems of acoustic window. In this article the clinical applications are revised more common of the contrast echocardiography

  4. Ultrasound contrast agents: An overview

    International Nuclear Information System (INIS)

    Cosgrove, David

    2006-01-01

    With the introduction of microbubble contrast agents, diagnostic ultrasound has entered a new era that allows the dynamic detection of tissue flow of both the macro and microvasculature. Underpinning this development is the fact that gases are compressible, and thus the microbubbles expand and contract in the alternating pressure waves of the ultrasound beam, while tissue is almost incompressible. Special software using multiple pulse sequences separates these signals from those of tissue and displays them as an overlay or on a split screen. This can be done at low acoustic pressures (MI < 0.3) so that the microbubbles are not destroyed and scanning can continue in real time. The clinical roles of contrast enhanced ultrasound scanning are expanding rapidly. They are established in echocardiography to improve endocardial border detection and are being developed for myocardial perfusion. In radiology, the most important application is the liver, especially for focal disease. The approach parallels that of dynamic CT or MRI but ultrasound has the advantages of high spatial and temporal resolution. Thus, small lesions that can be indeterminate on CT can often be studied with ultrasound, and situations where the flow is very rapid (e.g., focal nodular hyperplasia where the first few seconds of arterial perfusion may be critical to making the diagnosis) are readily studied. Microbubbles linger in the extensive sinusoidal space of normal liver for several minutes whereas they wash out rapidly from metastases, which have a low vascular volume and thus appear as filling defects. The method has been shown to be as sensitive as three-phase CT. Microbubbles have clinical uses in many other applications where knowledge of the microcirculation is important (the macrocirculation can usually be assessed adequately using conventional Doppler though there are a few important situations where the signal boost given by microbubbles is useful, e.g., transcranial Doppler for evaluating

  5. Impact of demographic factors, early family relationships and depressive symptomatology in teenage pregnancy.

    Science.gov (United States)

    Quinlivan, Julie A; Tan, Louisa H; Steele, Angela; Black, Kirsten

    2004-04-01

    Teenage pregnancy has been well studied from a demographic risk perspective, but less data examining the early interpersonal family experiences of teenage mothers are available. We aimed to explore the relative impact of demographic, early interpersonal family relationships and depressive symptomatology as associations for teenage, as compared to non-teenage, childbearing. A prospective cross-sectional cohort study was undertaken. Institutional ethics committee approval and informed consent were obtained. Data from consecutive teenage (teenage) and non-teenage (control) subgroups of antenatal women were compared. Subjects were interviewed and completed the following questionnaires: demographic, drug use and lifestyle; early life experiences; Hospital Anxiety and Depression Scale (HADS); and General Health Questionnaire-28. In multivariate analysis, the following factors had a significant independent association with younger age of motherhood in order of magnitude: a history of parental separation/divorce in early childhood; exposure to family violence in early childhood; illicit drug use (ever or in pregnancy); idealization of the pregnancy; low family income; a positive HADS-A or HADS-D subscale score; and a low level of education. Interventions to reduce the rate of teenage births need to be multifocal and should include strategies to address early childhood exposure to parental separation and violence, reduce idealization of pregnancy, diagnose psychological symptomatology and offer alternative career choices to children defaulting in the education system.

  6. Conservation biology for suites of species: Demographic modeling for Pacific island kingfishers

    Science.gov (United States)

    Kesler, D.C.; Haig, S.M.

    2007-01-01

    Conservation practitioners frequently extrapolate data from single-species investigations when managing critically endangered populations. However, few researchers initiate work with the intent of making findings useful to conservation efforts for other species. We presented and explored the concept of conducting conservation-oriented research for suites of geographically separated populations with similar natural histories, resource needs, and extinction threats. An example was provided in the form of an investigation into the population demography of endangered Micronesian kingfishers (Todiramphus cinnamominus). We provided the first demographic parameter estimates for any of the 12 endangered Pacific Todiramphus species, and used results to develop a population projection matrix model for management throughout the insular Pacific. Further, we used the model for elasticity and simulation analyses with demographic values that randomly varied across ranges that might characterize congener populations. Results from elasticity and simulation analyses indicated that changes in breeding adult survival exerted the greatest magnitude of influence on population dynamics. However, changes in nestling survival were more consistently correlated with population dynamics as demographic rates were randomly altered. We concluded that conservation practitioners working with endangered Pacific kingfishers should primarily focus efforts on factors affecting nestling and breeder survival, and secondarily address fledgling juveniles and helpers. Further, we described how the generalized base model might be changed to focus on individual populations and discussed the potential application of multi-species models to other conservation situations. ?? 2007 Elsevier Ltd. All rights reserved.

  7. Phase contrast STEM for thin samples: Integrated differential phase contrast

    International Nuclear Information System (INIS)

    Lazić, Ivan; Bosch, Eric G.T.; Lazar, Sorin

    2016-01-01

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

  8. Phase contrast STEM for thin samples: Integrated differential phase contrast

    Energy Technology Data Exchange (ETDEWEB)

    Lazić, Ivan, E-mail: ivan.lazic@fei.com; Bosch, Eric G.T.; Lazar, Sorin

    2016-01-15

    It has been known since the 1970s that the movement of the center of mass (COM) of a convergent beam electron diffraction (CBED) pattern is linearly related to the (projected) electrical field in the sample. We re-derive a contrast transfer function (CTF) for a scanning transmission electron microscopy (STEM) imaging technique based on this movement from the point of view of image formation and continue by performing a two-dimensional integration on the two images based on the two components of the COM movement. The resulting integrated COM (iCOM) STEM technique yields a scalar image that is linear in the phase shift caused by the sample and therefore also in the local (projected) electrostatic potential field of a thin sample. We confirm that the differential phase contrast (DPC) STEM technique using a segmented detector with 4 quadrants (4Q) yields a good approximation for the COM movement. Performing a two-dimensional integration, just as for the COM, we obtain an integrated DPC (iDPC) image which is approximately linear in the phase of the sample. Beside deriving the CTFs of iCOM and iDPC, we clearly point out the objects of the two corresponding imaging techniques, and highlight the differences to objects corresponding to COM-, DPC-, and (HA) ADF-STEM. The theory is validated with simulations and we present first experimental results of the iDPC-STEM technique showing its capability for imaging both light and heavy elements with atomic resolution and a good signal to noise ratio (SNR). - Highlights: • First DPC-based atomic resolution images of potential and charge density are obtained. • This is enabled by integration and differentiation of 2D DPC signals, respectively. • Integrated DPC (iDPC) based on 4 quadrant imaging is compared to iCOM imaging. • Noise analysis and comparison with standard STEM imaging modes is provided. • iDPC allows direct imaging of light (C, N, O …) and heavy (Ga, Au …) atoms together.

  9. Feasible Histories, Maximum Entropy

    International Nuclear Information System (INIS)

    Pitowsky, I.

    1999-01-01

    We consider the broadest possible consistency condition for a family of histories, which extends all previous proposals. A family that satisfies this condition is called feasible. On each feasible family of histories we choose a probability measure by maximizing entropy, while keeping the probabilities of commuting histories to their quantum mechanical values. This procedure is justified by the assumption that decoherence increases entropy. Finally, a criterion for identifying the nearly classical families is proposed

  10. The impact of mycotoxicoses on human history.

    Science.gov (United States)

    Peraica, Maja; Rašić, Dubravka

    2012-12-01

    Mycotoxicoses are acute or chronic diseases of humans and animals caused by mycotoxins, toxic compounds produced by moulds. Of about 400 known mycotoxins only a small number are known to cause mycotoxicoses in humans. Organs that are most targeted are those in which mycotoxins are metabolised, that is, the liver and kidneys, but the lesions may affect the neurological, respiratory, digestive, haematological, endocrine, and immune systems as well. The epidemics of mycotoxicoses are often connected with times of famine, when population consumes food that would not be consumed in normal circumstances. Mycotoxicoses have influenced human history, causing demographic changes, migrations, or even influencing the outcomes of wars. Fortunately, epidemics affecting so many persons and with so many fatalities belong to the past. Today they only appear in small communities such as schools and factory canteens. This paper presents epidemics and pandemics of mycotoxicoses that influenced human history.

  11. Cooperative Station History Forms

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Various forms, photographs and correspondence documenting the history of Cooperative station instrumentation, location changes, inspections, and...

  12. Public and popular history

    CERN Document Server

    De Groot, Jerome

    2013-01-01

    This interdisciplinary collection considers public and popular history within a global framework, seeking to understand considerations of local, domestic histories and the ways they interact with broader discourses. Grounded in particular local and national situations, the book addresses the issues associated with popular history in a globalised cultural world, such as: how the study of popular history might work in the future; new ways in which the terms 'popular' and 'public' might inform one another and nuance scholarship; transnational, intercultural models of 'pastness'; cultural translat

  13. Demographic crisis and recovery: a case study of the Xavante of Pimentel Barbosa.

    Science.gov (United States)

    Flowers, N

    1994-03-01

    This case study of the Xavante of Pimentel Barbosa is an example of an Amazonian Indian group that, when exposed to White society, experienced the common history of diseases and social disruption, and then eventually, recovered from the demographic shock, increased fertility, and reduced mortality. Early contact for the Xavante was during the early 18th century in Goias state, Brazil; by the end of the 19th century the Xavante had migrated west into Mato Grosso in isolation. Brazilian government interests (1940s) and a research expeditionary group (1962) resulted in health posts and extensive genetic, epidemiologic, and demographic studies. The results showed good physical and nutritional status, but stress from epidemic disease and social disruption. Conditions had improved by 1976, and the battle was with encroaching ranchers. Strong indian political action led to the securing of boundaries within the Pimentel Barbosa reservation by 1977. The population doubled from 249 in 1977 to 411 in 1988, and increased to 3 villages. There was evidence of a return to more traditional practices. Data collection for this analysis occurred during 1976-77 and 1988 and 1990. Results were provided for recent demographic change, recent births and deaths, factors affecting fertility, fertility change, parity and infant mortality, life expectancy changes, infanticide, population growth, marriage patterns, and health changes. Fertility histories were collected from 71 women in 1971 and 109 women in 1990. Difficulties were encountered due to Xavante differences in enumeration of children. In the comparison of the surveys in 1977 and 1990, there was close correspondence of reported births, and discrepancies of 4-9 births and in age at death. The difficulties encountered were attributed to problems with interpreters. The demographic analysis showed evidence of introduced diseases, which increased infant mortality and threatened population replacement, followed by decreased infant

  14. Influence of harvesting pressure on demographic tactics: Implications for wildlife management

    Science.gov (United States)

    Servanty, S.; Gaillard, J.-M.; Ronchi, F.; Focardi, S.; Baubet, E.; Gimenez, O.

    2011-01-01

    Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (??) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. Asymptotic ?? was 1??242 in the lightly hunted population and 1??115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2??63 and 1??27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. Compared with expected generation times of similar-sized ungulates (more than 6years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3??6years in the lightly hunted population and only 2??3years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of

  15. Identification of risk factors and demographic features of patients with peri partum cardiomyopathy

    International Nuclear Information System (INIS)

    Sharieff, S.; Khan, Shah-e-Zaman

    2002-01-01

    Objective: To describe and identify the demographic features and risk factors for peri partum cardiomyopathy (PPCM). Design: A prospective study: The study was conducted at the department of Adult Cardiology, National Institute of Cardiovascular Diseases (NICVD), Karachi, Pakistan from December 1999 to August 2001. Subjects and Methods: A total of 35 consecutive patients diagnosed to have peri partum cardiomyopathy (PPCM) on echocardiogram were enrolled. Proforma containing demographic characteristics and established risk factors for PPCM was established and filled carefully. The data gathered was analyzed statistically. Results: The mean age at the time of diagnosis was 30.8-6.74 years. Urdu speaking (Mohajir) population was found to be more affected ethnic group (42.9%) Majority of the patients was from lower socio-economic group with poor nutritional status (77%) and multiparous (77.14%). 25.7% had past history of PPCM and 71.4% presented during postpartum period. Mortality at six months was 22.8% while 42.9% had persistent disease and only 34.3% recovered completely. Conclusion: Advanced age, lower economic group with poor nutritional status, multi parity and past history of peri partum cardiomyopathy were identified as risk factors for the development of PPCM, especially among Mohajir population. There was no statistically significant difference between the clinical features and outcome of patients presented first time or with recurrent PPCM. We identified advanced age (>30 years), high LVEDD, and low ejection fraction (EF) at initial presentation as poor prognostic factors. (author)

  16. A history of the histories of econometrics

    NARCIS (Netherlands)

    Boumans, Marcel; Dupont-Kieffer, Ariane

    2011-01-01

    Econometricians have from the start considered historical knowledge of their own discipline as reflexive knowledge useful for delineating their discipline, that is, for setting its disciplinary boundaries with respect to its aims, its methods, and its scientific values. As such, the histories

  17. Is prevalence of colorectal polyps higher in patients with family history of colorectal cancer?

    OpenAIRE

    Murad-Regadas, Sthela Maria; Bezerra, Carla Camila Rocha; Peixoto, Ana Ligia Rocha; Regadas, Francisco Sérgio Pinheiro; Rodrigues, Lusmar Veras; Siebra, José Airton Gonçalves; da Silva Fernandes, Graziela Olivia; Vasconcelos, Rafael Aragão

    2015-01-01

    ABSTRACTObjectives:To assess the prevalence of polyps in patients with a family history of colorectal cancer, in comparison to asymptomatic individuals with indication for screening.Methods:A prospective study in a group of patients who underwent colonoscopy between 2012 and 2014. Patients were divided into two groups: Group I: no family history of colorectal cancer, and Group II: with a family history in first-degree relatives. Demographic characteristics, findings on colonoscopy...

  18. Future scenarios of land change based on empirical data and demographic trends

    Science.gov (United States)

    Sleeter, Benjamin M.; Wilson, Tamara; Sharygin, Ethan; Sherba, Jason

    2017-01-01

    Changes in land use and land cover (LULC) have important and fundamental interactions with the global climate system. Top-down global scale projections of land use change have been an important component of climate change research; however, their utility at local to regional scales is often limited. The goal of this study was to develop an approach for projecting changes in LULC based on land use histories and demographic trends. We developed a set of stochastic, empirical-based projections of LULC change for the state of California, for the period 2001–2100. Land use histories and demographic trends were used to project a “business-as-usual” (BAU) scenario and three population growth scenarios. For the BAU scenario, we projected developed lands would more than double by 2100. When combined with cultivated areas, we projected a 28% increase in anthropogenic land use by 2100. As a result, natural lands were projected to decline at a rate of 139 km2 yr−1; grasslands experienced the largest net decline, followed by shrublands and forests. The amount of cultivated land was projected to decline by approximately 10%; however, the relatively modest change masked large shifts between annual and perennial crop types. Under the three population scenarios, developed lands were projected to increase 40–90% by 2100. Our results suggest that when compared to the BAU projection, scenarios based on demographic trends may underestimate future changes in LULC. Furthermore, regardless of scenario, the spatial pattern of LULC change was likely to have the greatest negative impacts on rangeland ecosystems.

  19. Strong population bottleneck and repeated demographic expansions of Populus adenopoda (Salicaceae) in subtropical China.

    Science.gov (United States)

    Fan, Liqiang; Zheng, Honglei; Milne, Richard I; Zhang, Lei; Mao, Kangshan

    2018-03-14

    Glacial refugia and inter-/postglacial recolonization routes during the Quaternary of tree species in Europe and North America are well understood, but far less is known about those of tree species in subtropical eastern Asia. Thus, we have examined the phylogeographic history of Populus adenopoda (Salicaceae), one of the few poplars that naturally occur in this subtropical area. Genetic variations across the range of the species in subtropical China were surveyed using ten nuclear microsatellite loci and four chloroplast fragments (matK, trnG-psbK, psbK-psbI and ndhC-trnV). Coalescent-based analyses were used to test demographic and migration hypotheses. In addition, species distribution models (SDMs) were constructed to infer past, present and future potential distributions of the species. Thirteen chloroplast haplotypes were detected, and haplotype-rich populations were found in central and southern parts of the species' range. STRUCTURE analyses of nuclear microsatellite loci suggest obvious lineage admixture, especially in peripheral and northern populations. DIYABC analysis suggests that the species might have experienced two independent rounds of demographic expansions and a strong bottleneck in the late Quaternary. SDMs indicate that the species' range contracted during the Last Glacial Maximum (LGM), and contracted northward but expanded eastward during the Last Interglacial (LIG). Chloroplast data and SDMs suggest that P. adenopoda might have survived in multiple glacial refugia in central and southern parts of its range during the LGM. Populations of the Yunnan-Guizhou Plateau in the southern part have high chloroplast DNA diversity, but may have contributed little to the postglacial recolonization of northern and eastern parts. The three major demographic events inferred by DIYABC coincide with the initiation of the LIG, start of the LGM and end of the LGM, respectively. The species may have experienced multiple rounds of range contraction during

  20. Detecting the Evolution of Deliberate Fertility Control before the Demographic Transition in Germany

    Directory of Open Access Journals (Sweden)

    Aliaksandr Amialchuk

    2012-10-01

    Full Text Available BACKGROUND Pervious literature has established the existence of deliberate non-parity-specific fertility control in pre-transitional populations. However, less focus has been given to the timing of its onset. In addition, previous studies focused on the changes in fertility in response to the local prices of grains, which may be endogenous. OBJECTIVE This paper studies the emergence and evolution of deliberate fertility control by investigating the link between child mortality and economic stress on the one hand and non-parity-specific birth control on the other, in historic German villages between 1700 and 1900. METHODS Birth histories from fourteen German villages (1700-1900 and rye price series are used in a micro-level event history analysis. The fertility response of second and higher-order births to the mortality of children over age two and exogenous fluctuations in rye price are used as measures of the extent of deliberate non-parity-specific birth control. RESULTS Over the course of the demographic transition, the effect of the death of children generally increases after controlling for the effect of the death of children less than two years old. The negative fertility response to high rye prices before and in the year immediately following the price change occurred only after 1800. CONCLUSIONS The replacement and insurance effects associated with child mortality generally increased before the demographic transition. The emergence of the negative effect of high rye prices on fertility after 1800 further supports the presence and evolution of deliberate non-parity-specific fertility control before the demographic transition.