WorldWideScience

Sample records for contrasting demographic histories

  1. Contrasting demographic history and phylogeographical patterns in two Indo-Pacific gastropods.

    Science.gov (United States)

    Crandall, Eric D; Frey, Melissa A; Grosberg, Richard K; Barber, Paul H

    2008-01-01

    Marine species with ranges that span the Indo-Australian Archipelago (IAA) exhibit a range of phylogeographical patterns, most of which are interpreted in the context of vicariance between Indian and Pacific Ocean populations during Pliocene and Pleistocene low sea-level stands. However, patterns often vary among ecologically similar taxa, sometimes even within genera. This study compares phylogeographical patterns in two species of highly dispersive neritid gastropod, Nerita albicilla and Nerita plicata, with nearly sympatric ranges that span the Indo-Pacific. Mitochondrial COI sequences from >1000 individuals from 97 sites reveal similar phylogenies in both species (two divergent clades differing by 3.2% and 2.3%, for N. albicilla and N. plicata, respectively). However, despite ecological similarity and congeneric status, the two species exhibit phylogeographical discordance. N. albicilla has maintained reciprocal monophyly of Indian and Pacific Ocean populations, while N. plicata is panmictic between oceans, but displays a genetic cline in the Central Pacific. Although this difference might be explained by qualitatively different demographic histories, parameter estimates from three coalescent models indicate that both species have high levels of gene flow between demes (2Nem>75), and share a common history of population expansion that is likely associated with cyclical flooding of continental shelves and island lagoons following low sea-level stands. Results indicate that ecologically similar, codistributed species may respond very differently to shared environmental processes, suggesting that relatively minor differences in traits such as pelagic larval duration or microhabitat association may profoundly impact phylogeographical structure.

  2. 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.

  3. Convergent Phenotypic Evolution despite Contrasting Demographic Histories in the Fauna of White Sands.

    Science.gov (United States)

    Rosenblum, Erica Bree; Parent, Christine E; Diepeveen, Eveline T; Noss, Clay; Bi, Ke

    2017-08-01

    When are evolutionary outcomes predictable? Cases of convergent evolution can shed light on when, why, and how different species exhibit shared evolutionary trajectories. In particular, studying diverse species in a common environment can illuminate how different factors facilitate or constrain adaptive evolution. Here we integrate studies of pattern and process in the fauna at White Sands (New Mexico) to understand the determinants of convergent evolution. Numerous animal species at White Sands exhibit phenotypic convergence in response to a novel-and shared-selective environment: geologically young gypsum dunes. We synthesize 15 years of research on White Sands lizards to assess the contribution of natural selection, genetic architecture, and population demography to patterns of phenotypic evolution. We also present new data for two species of White Sands arthropods, Ammobaenetes arenicolus and Habronattus ustulatus. Overall, we find dramatic phenotypic convergence across diverse species at White Sands. Although the direction of phenotypic response is parallel, the magnitude of phenotypic response varies among species. We also find that species exhibit strikingly different demographic patterns across the ecotone. The species with the most genetic structure between White Sands and dark-soil populations generally exhibit the least phenotypic divergence, suggesting population demography as a key modulator of adaptation. Comparative studies are particularly important for understanding the determinants of convergence in natural systems.

  4. 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

    2015-08-01

    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

  5. 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

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

    African Journals Online (AJOL)

    Small yellow croaker, Larimichthys polyactis (Bleeker, 1877), a commercially important benthopelagic fish, is widely distributed in the Bohai, Yellow and East China Seas. To evaluate the population genetic structure and demographic history of L. polyactis, we sequenced the complete mitochondrial deoxyribonucleic acid ...

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

    African Journals Online (AJOL)

    Climatic oscillations during the Pleistocene ice ages in the Northwestern Pacific produced great changes in species' geographical distribution and abundance, which could be expected to have genetic consequences in marine fishes. In order to estimate the demographic history and genetic structure of Epinephelus akaara ...

  8. 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.

  9. 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.

  10. 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...

  11. 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

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

    Indian Academy of Sciences (India)

    The Mantel test showed strong isolation by distance, and AMOVA results for global and regional scales confirmed that the geography had acted as the main driving force in shaping the current pattern of mtDNA diversity, rather than linguistic similarity. The results of demographic analyses, in agreement with archaeological ...

  13. Salivary alpha-amylase during pregnancy: diurnal course and associations with obstetric history, maternal demographics, and mood.

    Science.gov (United States)

    Giesbrecht, Gerald F; Granger, Douglas A; Campbell, Tavis; Kaplan, Bonnie

    2013-03-01

    Diurnal patterns of salivary alpha amylase (sAA) in pregnant women have not previously been described. The current study employed ecological momentary assessment to examine the association between the diurnal sAA, obstetric history, maternal demographics, and mood during pregnancy. Saliva was self-collected by 83 pregnant women (89% White, age 25.3-43.0 years; mean gestational age 21.9 weeks, range 6-37 weeks; gravida 1-6) at home over three days. Results indicated that current pregnancy (gestational age and fetal sex) and maternal demographics were not related to diurnal sAA. In contrast, a history of previous miscarriage (Parameter = -.17; SE = .05; p history, trait anxiety (Parameter = .16; SE = .04; p pregnancy is sensitive to emotional arousal. Evaluating diurnal patterns of sAA holds promise for advancing understanding of how emotional arousal during pregnancy may affect fetal development. Copyright © 2012 Wiley Periodicals, Inc.

  14. Radiocarbon test for demographic events in written and oral history.

    Science.gov (United States)

    Edinborough, Kevan; Porčić, Marko; Martindale, Andrew; Brown, Thomas Jay; Supernant, Kisha; Ames, Kenneth M

    2017-11-21

    We extend an established simulation-based method to test for significant short-duration (1-2 centuries) demographic events known from one documented historical and one oral historical context. Case study 1 extrapolates population data from the Western historical tradition using historically derived demographic data from the catastrophic European Black Death/bubonic plague ( Yersinia pestis ). We find a corresponding statistically significant drop in absolute population using an extended version of a previously published simulation method. Case study 2 uses this refined simulation method to test for a settlement gap identified in oral historical records of descendant Tsimshian First Nations communities from the Prince Rupert Harbour region of the Pacific Northwest region of British Columbia, Canada. Using a regional database of n = 523 radiocarbon dates, we find a significant drop in relative population using the extended simulation-based method consistent with Tsimshian oral records. We conclude that our technical refinement extends the utility of radiocarbon simulation methods and can provide a rigorous test of demographic predictions derived from a range of historical sources.

  15. 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 i...

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

    Indian Academy of Sciences (India)

    FATAH ZAREI

    lence of animal domestication and cultivation around 9,000. YBP and continuing to the present. In contrast, the U-type. mtDNAs show a population growth between 20,000 and. 10,000 YBP seeming to represent earlier hunter-gatherers that initiated farming practices and admixed with immigrant populations (Fu et al. 2012).

  17. 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...

  18. 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.

  19. Population demographic history can cause the appearance of recombination hotspots.

    Science.gov (United States)

    Johnston, Henry R; Cutler, David J

    2012-05-04

    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. Copyright © 2012 The American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.

  20. 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

  1. 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...

  2. Diversification, biogeographic pattern, and demographic history of Taiwanese Scutellaria species inferred from nuclear and chloroplast DNA.

    Directory of Open Access Journals (Sweden)

    Yu-Chung Chiang

    Full Text Available The ragged topography created by orogenesis generates diversified habitats for plants in Taiwan. In addition to colonization from nearby mainland China, high species diversity and endemism of plants is also present in Taiwan. Five of the seven Scutellaria species (Lamiaceae in Taiwan, for example, are endemic to the island. Hypotheses of multiple sources or in situ radiation have arisen to explain the high endemism of Taiwanese species. In this study, phylogenetic analyses using both nuclear and chloroplast markers revealed the multiple sources of Taiwanese Scutellaria species and confirmed the rapid and recent speciation of endemic species, especially those of the "indica group" composed of S. indica, S. austrotaiwanensis, S. tashiroi, and S. playfairii. The common ancestors of the indica group colonized first in northern Taiwan and dispersed regionally southward and eastward. Climate changes during glacial/interglacial cycles led to gradual colonization and variance events in the ancestors of these species, resulting in the present distribution and genetic differentiation of extant populations. Population decline was also detected in S. indica, which might reflect a bottleneck effect from the glacials. In contrast, the recently speciated endemic members of the indica group have not had enough time to accumulate much genetic variation and are thus genetically insensitive to demographic fluctuations, but the extant lineages were spatially expanded in the coalescent process. This study integrated phylogenetic and population genetic analyses to illustrate the evolutionary history of Taiwanese Scutellaria of high endemism and may be indicative of the diversification mechanism of plants on continental islands.

  3. How the world survived the population bomb: lessons from 50 years of extraordinary demographic history.

    Science.gov (United States)

    Lam, David

    2011-11-01

    The world population will reach 7 billion in late 2011, a demographic milestone that is causing renewed attention to the challenges caused by population growth. This article looks at the last 50 years of demographic change, one of the most extraordinary periods in demographic history. During this period, world population grew at rates that have never been seen before and will almost surely never be seen again. There were many concerns about the potential impact of rapid population growth in the 1960s, including mass starvation in countries such as India, depletion of nonrenewable resources, and increased poverty in low-income countries. The actual experience was very different. World food production increased faster than world population in every decade since the 1960s, resource prices fell during most of the period, and poverty declined significantly in much of the developing world. The article considers the economic and demographic explanations for the surprising successes of this important period in demographic history. It also looks at regions that have been less successful, especially Africa, and at the lessons for dealing with the important challenges that still remain.

  4. 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...

  5. 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.

  6. Population genetic structure and demographic history of the black fly vector, Simulium nodosum in Thailand.

    Science.gov (United States)

    Chaiyasan, P; Pramual, P

    2016-09-01

    An understanding of the genetic structure and diversity of vector species is crucial for effective control and management. In this study, mitochondrial DNA sequences were used to examine the genetic structure, diversity and demographic history of a black fly vector, Simulium nodosum Puri (Diptera: Simuliidae), in Thailand. A total of 145 sequences were obtained from 10 sampling locations collected across geographical ranges in the country. Low genetic diversity was found in populations of S. nodosum that could be explained by the recent population history of this species. Demographic history analysis revealed a signature of demographic expansion dating back to only 2600-5200 years ago. Recent population expansion in S. nodosum possibly followed an increase in agriculture that enabled its hosts', humans and domestic animals, densities to increase. Alternatively, the Thai populations could be a derivative of an older expansion event in the more northern populations. Mitochondrial DNA genealogy revealed no genetically divergent lineages, which agrees with the previous cytogenetic study. Genetic structure analyses found that only 27% of the pairwise comparisons were significantly different. The most likely explanation for the pattern of genetic structuring is the effect of genetic drift because of recent colonization. © 2016 The Royal Entomological Society.

  7. Spatial genetics of wild tomato species reveals roles of the Andean geography on demographic history.

    Science.gov (United States)

    Nakazato, Takuya; Housworth, Elizabeth A

    2011-01-01

    Understanding the demographic history of natural populations in relation to the geographic features in their habitats is an important step toward deciphering the mechanisms of evolutionary processes in nature. This study investigates how the complex geographic and ecological features of the Andes play a role in demographic history, species divergence, dispersal patterns, and hybridization in wild tomato species. We investigated spatial genetics of two closely related wild tomato species, Solanum lycopersicum and S. pimpinellifolium, by integrating amplified fragment length polymorphism (AFLP) marker data and geographic information system (GIS)-derived geographic and climatic data. The two species represent genetically distinct lineages largely separated by the Andes, but hybridize extensively in central to northern Ecuador, likely mediated by the transitional climatic conditions between those of the two species. Solanum lycospericum has likely experienced a severe population bottleneck during the colonization of the eastern Andes followed by a rapid population expansion. The study demonstrates that the evolutionary patterns of the two wild tomatoes, including demographic history, dispersal patterns, interspecific divergence, and hybridization, are intimately related to the complex geographic and ecological features of the Andes. Integrating genetic data across the genome and GIS-derived environmental data can provide insights into the patterns of complex evolutionary processes in nature.

  8. 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

  9. 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 hypotheses. However, by evaluating the consistency of theoretical predictions with empirically-estimated effective size, insights can be gained regarding life-history characteristics, as well as 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. Here we describe and demonstrate this approach by addressing the conservation of a reintroduced population of Asiatic wild ass (Equus hemionus). We estimate the variance effective size (N ev ) from genetic data (N ev = 24.3), and we formulate predictions for the impacts on N ev of demography, polygyny, female variance in life-time reproductive success, and heritability of female reproductive success. By contrasting the genetic estimation with theoretical predictions, we find that polygyny is the strongest factor effecting genetic drift, as only when accounting for polygyny were predictions consistent with the genetically-measured N ev , with 10.6% mating males per generation when heritability of female RS was unaccounted for (polygyny responsible for 81% decrease in N ev ), and 19.5% when it was accounted for (polygyny responsible for 67% decrease in N ev ). Heritability of female reproductive success was also found to affect N ev , with h f 2 = 0.91 (heritability responsible for 41% decrease in N ev ). The low effective population size is of concern, and we suggest specific management actions focusing on factors identified as strongly affecting N ev -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

  10. Contrasting life histories in neighbouring populations of a large mammal.

    Science.gov (United States)

    Mason, Tom H E; Chirichella, Roberta; Richards, Shane A; Stephens, Philip A; Willis, Stephen G; Apollonio, Marco

    2011-01-01

    A fundamental life history question is how individuals should allocate resources to reproduction optimally over time (reproductive allocation). The reproductive restraint hypothesis predicts that reproductive effort (RE; the allocation of resources to current reproduction) should peak at prime-age, whilst the terminal investment hypothesis predicts that individuals should continue to invest more resources in reproduction throughout life, owing to an ever-decreasing residual reproductive value. There is evidence supporting both hypotheses in the scientific literature. We used an uncommonly large, 38 year dataset on Alpine chamois (Rupicapra rupicapra) shot at various times during the rutting period to test these two hypotheses. We assumed that body mass loss in rutting males was strongly related to RE and, using a process-based approach, modelled how male relative mass loss rates varied with age. For different regions of our study area, we provide evidence consistent with different hypotheses for reproductive allocation. In sites where RE declined in older age, this appears to be strongly linked to declining body condition in old males. In this species, terminal investment may only occur in areas with lower rates of body mass senescence. Our results show that patterns of reproductive allocation may be more plastic than previously thought. It appears that there is a continuum from downturns in RE at old age to terminal investment that can be manifest, even across adjacent populations. Our work identifies uncertainty in the relationship between reproductive restraint and a lack of competitive ability in older life (driven by body mass senescence); both could explain a decline in RE in old age and may be hard to disentangle in empirical data. We discuss a number of environmental and anthropogenic factors which could influence reproductive life histories, underlining that life history patterns should not be generalised across different populations.

  11. Contrasting life histories in neighbouring populations of a large mammal.

    Directory of Open Access Journals (Sweden)

    Tom H E Mason

    Full Text Available A fundamental life history question is how individuals should allocate resources to reproduction optimally over time (reproductive allocation. The reproductive restraint hypothesis predicts that reproductive effort (RE; the allocation of resources to current reproduction should peak at prime-age, whilst the terminal investment hypothesis predicts that individuals should continue to invest more resources in reproduction throughout life, owing to an ever-decreasing residual reproductive value. There is evidence supporting both hypotheses in the scientific literature.We used an uncommonly large, 38 year dataset on Alpine chamois (Rupicapra rupicapra shot at various times during the rutting period to test these two hypotheses. We assumed that body mass loss in rutting males was strongly related to RE and, using a process-based approach, modelled how male relative mass loss rates varied with age. For different regions of our study area, we provide evidence consistent with different hypotheses for reproductive allocation. In sites where RE declined in older age, this appears to be strongly linked to declining body condition in old males. In this species, terminal investment may only occur in areas with lower rates of body mass senescence.Our results show that patterns of reproductive allocation may be more plastic than previously thought. It appears that there is a continuum from downturns in RE at old age to terminal investment that can be manifest, even across adjacent populations. Our work identifies uncertainty in the relationship between reproductive restraint and a lack of competitive ability in older life (driven by body mass senescence; both could explain a decline in RE in old age and may be hard to disentangle in empirical data. We discuss a number of environmental and anthropogenic factors which could influence reproductive life histories, underlining that life history patterns should not be generalised across different populations.

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

    DEFF Research Database (Denmark)

    Goldstein, Josephine

    2017-01-01

    species involved in mass occurrence have been covered in previous studies, providing important insight into diverse life stage-specific adaptation strategies to changing environmental conditions. Quantification of the demographic rates that characterize different life-history stages however has remained...... scarce and patchy, although may unravel the basic principles underlying jellyfish blooms. In this thesis, vital rates for all life stages of the common jellyfish Aurelia aurita (Scyphozoa, Cnidaria) are documented, which allows pointing out important mechanisms that drive the population dynamics......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...

  13. Life-history evolution in guppies VIII: the demographics of density regulation in guppies (Poecilia reticulata).

    Science.gov (United States)

    Reznick, David N; Bassar, Ronald D; Travis, Joseph; Helen Rodd, F

    2012-09-01

    In prior research, we found the way guppy life histories evolve in response to living in environments with a high or low risk of predation is consistent with life-history theory that assumes no density dependence. We later found that guppies from high-predation environments experience higher mortality rates than those from low-predation environments, but the increased risk was evenly distributed across all age/size classes. Life-history theory that assumes density-independent population growth predicts that life histories will not evolve under such circumstances, yet we have shown with field introduction experiments that they do evolve. However, theory that incorporates density regulation predicts this pattern of mortality can result in the patterns of life-history evolution we had observed. Here we report on density manipulation experiments performed in populations of guppies from low-predation environments to ask whether natural populations normally experience density regulation and, if so, to characterize the short-term demographic changes that underlie density regulation. Our experiments reveal that these populations are density regulated. Decreased density resulted in higher juvenile growth, decreased juvenile mortality rates, and increased reproductive investment by adult females. Increased density causes reduced offspring size, decreased fat storage by adult females, and increased adult mortality. © 2012 The Author(s). Evolution© 2012 The Society for the Study of Evolution.

  14. Statistical inference on genetic data reveals the complex demographic history of human populations in central Asia.

    Science.gov (United States)

    Palstra, Friso P; Heyer, Evelyne; Austerlitz, Frédéric

    2015-06-01

    The demographic history of modern humans constitutes a combination of expansions, colonizations, contractions, and remigrations. The advent of large scale genetic data combined with statistically refined methods facilitates inference of this complex history. Here we study the demographic history of two genetically admixed ethnic groups in Central Asia, an area characterized by high levels of genetic diversity and a history of recurrent immigration. Using Approximate Bayesian Computation, we infer that the timing of admixture markedly differs between the two groups. Admixture in the traditionally agricultural Tajiks could be dated back to the onset of the Neolithic transition in the region, whereas admixture in Kyrgyz is more recent, and may have involved the westward movement of Turkic peoples. These results are confirmed by a coalescent method that fits an isolation-with-migration model to the genetic data, with both Central Asian groups having received gene flow from the extremities of Eurasia. Interestingly, our analyses also uncover signatures of gene flow from Eastern to Western Eurasia during Paleolithic times. In conclusion, the high genetic diversity currently observed in these two Central Asian peoples most likely reflects the effects of recurrent immigration that likely started before historical times. Conversely, conquests during historical times may have had a relatively limited genetic impact. These results emphasize the need for a better understanding of the genetic consequences of transmission of culture and technological innovations, as well as those of invasions and conquests. © The Author 2015. 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.

  15. Exploring Approximate Bayesian Computation for inferring recent demographic history with genomic markers in nonmodel species.

    Science.gov (United States)

    Elleouet, Joane S; Aitken, Sally N

    2018-01-22

    Approximate Bayesian computation (ABC) is widely used to infer demographic history of populations and species using DNA markers. Genomic markers can now be developed for nonmodel species using reduced representation library (RRL) sequencing methods that select a fraction of the genome using targeted sequence capture or restriction enzymes (genotyping-by-sequencing, GBS). We explored the influence of marker number and length, knowledge of gametic phase, and tradeoffs between sample size and sequencing depth on the quality of demographic inferences performed with ABC. We focused on two-population models of recent spatial expansion with varying numbers of unknown parameters. Performing ABC on simulated data sets with known parameter values, we found that the timing of a recent spatial expansion event could be precisely estimated in a three-parameter model. Taking into account uncertainty in parameters such as initial population size and migration rate collectively decreased the precision of inferences dramatically. Phasing haplotypes did not improve results, regardless of sequence length. Numerous short sequences were as valuable as fewer, longer sequences, and performed best when a large sample size was sequenced at low individual depth, even when sequencing errors were added. ABC results were similar to results obtained with an alternative method based on the site frequency spectrum (SFS) when performed with unphased GBS-type markers. We conclude that unphased GBS-type data sets can be sufficient to precisely infer simple demographic models, and discuss possible improvements for the use of ABC with genomic data. © 2018 John Wiley & Sons Ltd.

  16. 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.

  17. Demographic History of Indigenous Populations in Mesoamerica Based on mtDNA Sequence Data.

    Science.gov (United States)

    González-Martín, Antonio; Gorostiza, Amaya; Regalado-Liu, Lucía; Arroyo-Peña, Sergio; Tirado, Sergio; Nuño-Arana, Ismael; Rubi-Castellanos, Rodrigo; Sandoval, Karla; Coble, Michael D; Rangel-Villalobos, Héctor

    2015-01-01

    The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before.

  18. 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

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

    Directory of Open Access Journals (Sweden)

    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

  20. Specialist and generalist symbionts show counterintuitive levels of genetic diversity and discordant demographic histories along the Florida Reef Tract

    Science.gov (United States)

    Titus, Benjamin M.; Daly, Marymegan

    2017-03-01

    Specialist and generalist life histories are expected to result in contrasting levels of genetic diversity at the population level, and symbioses are expected to lead to patterns that reflect a shared biogeographic history and co-diversification. We test these assumptions using mtDNA sequencing and a comparative phylogeographic approach for six co-occurring crustacean species that are symbiotic with sea anemones on western Atlantic coral reefs, yet vary in their host specificities: four are host specialists and two are host generalists. We first conducted species discovery analyses to delimit cryptic lineages, followed by classic population genetic diversity analyses for each delimited taxon, and then reconstructed the demographic history for each taxon using traditional summary statistics, Bayesian skyline plots, and approximate Bayesian computation to test for signatures of recent and concerted population expansion. The genetic diversity values recovered here contravene the expectations of the specialist-generalist variation hypothesis and classic population genetics theory; all specialist lineages had greater genetic diversity than generalists. Demography suggests recent population expansions in all taxa, although Bayesian skyline plots and approximate Bayesian computation suggest the timing and magnitude of these events were idiosyncratic. These results do not meet the a priori expectation of concordance among symbiotic taxa and suggest that intrinsic aspects of species biology may contribute more to phylogeographic history than extrinsic forces that shape whole communities. The recovery of two cryptic specialist lineages adds an additional layer of biodiversity to this symbiosis and contributes to an emerging pattern of cryptic speciation in the specialist taxa. Our results underscore the differences in the evolutionary processes acting on marine systems from the terrestrial processes that often drive theory. Finally, we continue to highlight the Florida Reef

  1. 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

  2. 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

  3. 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

  4. 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....

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

    Science.gov (United States)

    Zhao, Shancen; Zheng, Pingping; Dong, Shanshan; Zhan, Xiangjiang; Wu, Qi; Guo, Xiaosen; Hu, Yibo; He, Weiming; Zhang, Shanning; Fan, Wei; Zhu, Lifeng; Li, Dong; Zhang, Xuemei; Chen, Quan; Zhang, Hemin; Zhang, Zhihe; Jin, Xuelin; Zhang, Jinguo; Yang, Huanming; Wang, Jian; Wang, Jun; Wei, Fuwen

    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 population expansions, two bottlenecks and two divergences. Evidence indicated that, whereas global changes in climate were the primary drivers of population fluctuation for millions of years, human activities likely underlie recent population divergence and serious decline. We identified three distinct panda populations that show genetic adaptation to their environments. However, in all three populations, anthropogenic activities have negatively affected pandas for 3,000 years.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    Directory of Open Access Journals (Sweden)

    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

  12. Recent demographic history and present fine-scale structure in the Northwest Atlantic leatherback (Dermochelys coriacea turtle population.

    Directory of Open Access Journals (Sweden)

    Erica Molfetti

    Full Text Available 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

  13. Genomic Analysis of Demographic History and Ecological Niche Modeling in the Endangered Sumatran Rhinoceros Dicerorhinus sumatrensis.

    Science.gov (United States)

    Mays, Herman L; Hung, Chih-Ming; Shaner, Pei-Jen; Denvir, James; Justice, Megan; Yang, Shang-Fang; Roth, Terri L; Oehler, David A; Fan, Jun; Rekulapally, Swanthana; Primerano, Donald A

    2018-01-08

    The vertebrate extinction rate over the past century is approximately 22-100 times greater than background extinction rates [1], and large mammals are particularly at risk [2, 3]. Quaternary megafaunal extinctions have been attributed to climate change [4], overexploitation [5], or a combination of the two [6]. Rhinoceroses (Family: Rhinocerotidae) have a rich fossil history replete with iconic examples of climate-induced extinctions [7], but current pressures threaten to eliminate this group entirely. The Sumatran rhinoceros (Dicerorhinus sumatrensis) is among the most imperiled mammals on earth. The 2011 population was estimated at ≤216 wild individuals [8], and currently the species is extirpated, or nearly so, throughout the majority of its former range [8-12]. Understanding demographic history is important in placing current population status into a broader ecological and evolutionary context. Analysis of the Sumatran rhinoceros genome reveals extreme changes in effective population size throughout the Pleistocene. Population expansion during the early to middle Pleistocene was followed by decline. Ecological niche modeling indicated that changing climate most likely played a role in the decline of the Sumatran rhinoceros, as less suitable habitat on an emergent Sundaland corridor isolated Sumatran rhinoceros populations. By the end of the Pleistocene, the Sundaland corridor was submerged, and populations were fragmented and consequently reduced to low Holocene levels from which they would never recover. Past events denuded the Sumatran rhinoceros of genetic diversity through population decline, fragmentation, or some combination of the two and most likely made the species even more susceptible to later exploitation and habitat loss. VIDEO ABSTRACT. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  14. CONTRAST

    DEFF Research Database (Denmark)

    Kristensen, Thomas Krogsgaard

    2007-01-01

    Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon.......Dette er en afrapportering fra den årlige CONTRAST workshop, der i 2007 blev afholdt i Yaoundé, Cameroon....

  15. 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

  16. 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.

  17. 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

  18. 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

  19. Demographic factors, rearing and health history: its relation with nutrition and child development

    OpenAIRE

    Cortés Moreno, Assol; Universidad Nacional Autónoma de México-FES Iztacala; Avilés Flores, Ana Laura; Universidad Nacional Autónoma de México-FES Iztacala

    2010-01-01

    Effects of undernourishment on psychological development vary according psychosocial factors. This study assessed the impact of demographic, familiar, and rearing variables on nourishment and psychological development in children aged complementary feeding. A sample of 124 child-caregiver dyads from four different socioeconomic and nutritional index communities from México participated. Anthropometrics and child development were measured. Prediction power of demographics, rearing practices, a...

  20. 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.

  1. Population structure and demographic history of a tropical lowland rainforest tree species Shorea parvifolia (Dipterocarpaceae) from Southeastern Asia

    Science.gov (United States)

    Iwanaga, Hiroko; Teshima, Kosuke M; Khatab, Ismael A; Inomata, Nobuyuki; Finkeldey, Reiner; Siregar, Iskandar Z; Siregar, Ulfah J; Szmidt, Alfred E

    2012-01-01

    Distribution of tropical rainforests in Southeastern Asia has changed over geo-logical time scale, due to movement of tectonic plates and/or global climatic changes. Shorea parvifolia is one of the most common tropical lowland rainforest tree species in Southeastern Asia. To infer population structure and demographic history of S. parvifolia, as indicators of temporal changes in the distribution and extent of tropical rainforest in this region, we studied levels and patterns of nucleotide polymorphism in the following five nuclear gene regions: GapC, GBSSI, PgiC, SBE2, and SODH. Seven populations from peninsular Malaysia, Sumatra, and eastern Borneo were included in the analyses. STRUCTURE analysis revealed that the investigated populations are divided into two groups: Sumatra-Malay and Borneo. Furthermore, each group contained one admixed population. Under isolation with migration model, divergence of the two groups was estimated to occur between late Pliocene (2.6 MYA) and middle Pleistocene (0.7 MYA). The log-likelihood ratio tests of several demographic models strongly supported model with population expansion and low level of migration after divergence of the Sumatra-Malay and Borneo groups. The inferred demographic history of S. parvifolia suggested the presence of a scarcely forested land bridge on the Sunda Shelf during glacial periods in the Pleistocene and predominance of tropical lowland rainforest at least in Sumatra and eastern Borneo. PMID:22957170

  2. 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.

  3. Implant and endodontic treatment selection are influenced by patients' demographic characteristics, insurance status, and medical history: A retrospective cohort study.

    Science.gov (United States)

    Chatzopoulos, Georgios S; Wolff, Larry F

    2017-01-01

    The aim of this study was to examine any potential association between demographic characteristics, socioeconomic status, dental insurance, and medical and tobacco history between patients that received endodontic treatment or extraction and implant treatment in a university dental clinic. Dental charts of patients who received root canal treatment and implant therapy were retrieved from the University of Minnesota School of Dentistry records. Age at the time of the procedure, gender, medical history, tobacco use, dental insurance status, zip code, and type of treatment provided were recorded. Patients who had both treatment modalities were excluded from the analysis. A total of 8,540 records of patients with a mean age of 50.66 years who have received either endodontic treatment (73.6%) or implant therapy (26.4%) were included. A statistically significant (P implant treatment as related to age, socioeconomic status, high blood pressure, asthma, thyroid disorders, arthritis, artificial joint, osteoporosis, depression, anxiety, cancer, and cancer treatment. Nonsmokers were significantly more likely to select a treatment plan with implants rather than an endodontic therapy. Within the limitations of this retrospective study, demographic parameters, insurance status, smoking, and medical history significantly affected the treatment selection between implant and endodontic treatment in a university setting.

  4. Demographic variations in HIV testing history among emergency department patients: implications for HIV screening in US emergency departments

    Science.gov (United States)

    Merchant, Roland C; Catanzaro, Bethany M; Seage, George R; Mayer, Kenneth H; Clark, Melissa A; DeGruttola, Victor G; Becker, Bruce M

    2011-01-01

    Objective To determine the proportion of emergency department (ED) patients who have been tested for human immunodeficiency virus (HIV) infection and assess if patient history of HIV testing varies according to patient demographic characteristics. Design From July 2005–July 2006, a random sample of 18–55-year-old English-speaking patients being treated for sub-critical injury or illness at a northeastern US ED were interviewed on their history of HIV testing. Logistic regression models were created to compare patients by their history of being tested for HIV according to their demography. Odds ratios (ORs) with 95% confidence intervals (CIs) were estimated. Results Of 2107 patients surveyed who were not known to be HIV-infected, the median age was 32 years; 54% were male, 71% were white, and 45% were single/never married; 49% had private health-care insurance and 45% had never been tested for HIV. Of the 946 never previously tested for HIV, 56.1% did not consider themselves at risk for HIV. In multivariable logistic regression analyses, those less likely to have been HIV tested were male (OR: 1.32 [1.37–2.73]), white (OR: 1.93 [1.37–2.73]), married (OR: 1.53 [1.12–2.08]), and had private health-care insurance (OR: 2.10 [1.69–2.61]). There was a U-shaped relationship between age and history of being tested for HIV; younger and older patients were less likely to have been tested. History of HIV testing and years of formal education were not related. Conclusion Almost half of ED patients surveyed had never been tested for HIV. Certain demographic groups are being missed though HIV diagnostic testing and screening programmes in other settings. These groups could potentially be reached through universal screening. PMID:19564517

  5. 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.

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

    Science.gov (United States)

    2013-01-01

    Background 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. Results 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. Conclusions 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

  7. 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.

  8. 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...... here for comparison. The analyses of gene diversity excess at 15 unlinked microsatellite markers did not reveal any sign of a severe bottleneck to have occurred within approximately 1200 years' history of the Faroese population. The extensive LD in this population may, therefore, have arisen primarily...

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

    DEFF Research Database (Denmark)

    Jorgensen, T.H.; Degn, B.; Wang, A.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...

  10. 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 ...

  11. 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).

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

    Science.gov (United States)

    Ostfeld, Richard S; Levi, Taal; Jolles, Anna E; Martin, Lynn B; Hosseini, Parviez R; Keesing, Felicia

    2014-01-01

    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.

  13. 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.

  14. Demographic history and genetic structure of the Welsh settlement in Patagonia (1865-1920

    Directory of Open Access Journals (Sweden)

    Crognier, Emile

    2007-01-01

    Full Text Available Although migrations have been thoroughly studied, still little is known about colonization processes. This study analyses the demographic and genetic structures of a colonization process. All the Welsh migrants to the Chubut (Argentina from year 1865 until year 1925 were identified and their contribution to the gene pool of the colony estimated from genealogies. Three waves of immigration which arrived in 1865, 1874 and 1886 were the main population component, besides a high fertility. In 1868 the population was principally composed of reproductive adults. In 1876, young children and reproductive adults dominated. In 1895 it was a typical young population. In 1920 an ageing trend was already perceptible. The origins of the settlers were so varied that the colony may be considered a sampling at random in the Welsh gene pool. 40% of the founders did not contribute genes. The settling of the Welsh in the Chubut presents two characteristics that may be common to any colonization process: (1 the evolution of the demographic structure from a predominantly young adult male composition to a balance in both sexes and ages. (2 The ‘genetic cost’ resulting from the loss of the genes of some of the founders.

  15. Quaternary evolution and ice sheet history of contrasting landscapes in Uummannaq and Sukkertoppen, western Greenland

    Science.gov (United States)

    Beel, C. R.; Lifton, N. A.; Briner, J. P.; Goehring, B. M.

    2016-10-01

    Constraining the history of the Greenland Ice Sheet (GIS) is important for improving our understanding of ice sheet dynamics and landscape evolution processes. We analyzed in situ cosmogenic 10Be and 26Al in 26 rock samples from two high-elevation landscapes adjacent to the GIS, minimally eroded by past glaciations and of differing character in Uummannaq (n = 16) and Sukkertoppen (n = 10), western Greenland. The Uummannaq region is characterized by a marine embayment with islands and peninsulas, where the margin of the GIS is marine-based, whereas the Sukkertoppen landscape resides within the wide terrestrial fringe outboard of the land-terminating portion of the southwestern GIS margin. We targeted landscapes for sampling with highly weathered surfaces adjacent to cold-based portions of extant ice caps (indicated by preservation of fragile, dead vegetation emerging from beneath retreating ice margins). Paired isotope results require differing surface histories between the two areas. Many surfaces in the Uummannaq region have minimum exposure durations up to ca. 300 kyr, but with no significant burial. Most surfaces in the Sukkertoppen region, however, yield complex exposure histories with minimum cumulative exposure durations up to ca. 100 kyr and minimum cumulative burial durations up to ca. 400 kyr, yielding minimum total surface histories of up to 500 ka. These findings suggest that parts of the Uummannaq landscape may have been continuously exposed throughout much of the middle and late Quaternary. On the other hand, the high-altitude surfaces in the Sukkertoppen region were largely preserved beneath minimally-erosive, cold-based ice during the same period. Data from the Uummannaq region thus stand in contrast not only to the Sukkertoppen region, but also to other sites surrounding Baffin Bay reported in previous studies. We hypothesize that surfaces in the Uummannaq region may have remained as nunataks above the Last Glacial Maximum (LGM) ice sheet surface

  16. 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

  17. Genetic signals of past demographic changes and the history of oak populations in California

    Science.gov (United States)

    Dodd, R. S.

    2009-04-01

    A retrospective view of species' demographic changes can inform on population stability through times of climatic change and the origins and spatial structure of genetic diversity in contemporary populations. The former provides the means to predict responses to future climatic change, while the latter allows us to infer the ability of populations to buffer the effects of reductions in population size and fragmentation. The approximately 1.8 my of the Pleistocene is believed to have had a significant impact on diversity through high rates of extinction during early glacial cycles and population expansions and contractions during the later cycles. In the Mediterranean basin, early emphasis on taxa with wide latitudinal ranges led to models of refugial sites and subsequent recolonization routes that could explain geographic patterns in genetic diversity, with a trend towards reduced genetic diversity in the north. More recently, the study of strictly Mediterranean taxa has revealed relictual sites that have persisted over very long periods of time, commonly relatively poor in diversity, but populations well differentiated from one site to another. In California, relatively little is known of the population dynamics of plant taxa during the Pleistocene glacial cycles, or to what extent differentiation today is a result of pre-Pleistocene events. For several animal taxa, differentiation between Coastal and Sierran taxa are believed to date to the Pliocene. Major demographic changes resulting in population isolation, bottlenecks, founder events and population expansions leave a genetic signal that can be detected through appropriate genetic markers and analyses. Such signals help to infer whether past climate fluctuations have had important effects on population demographics. Here, I will focus on key oak species of the California mediterranean climate zone. I will explore the likely effects of the last glacial maximum on oak populations using palaeoclimate and niche

  18. 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

  19. 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.

  20. 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.

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

    Science.gov (United States)

    Dunstan, Andrew J; Ward, Peter D; Marshall, N Justin

    2011-02-10

    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.

  2. 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.

  3. 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.

  4. Genetic structuring and recent demographic history of red pandas (Ailurus fulgens) inferred from microsatellite and mitochondrial DNA.

    Science.gov (United States)

    Hu, Yibo; Guo, Yu; Qi, Dunwu; Zhan, Xiangjiang; Wu, Hua; Bruford, Michael W; Wei, Fuwen

    2011-07-01

    Clarification of the genetic structure and population history of a species can shed light on the impacts of landscapes, historical climate change and contemporary human activities and thus enables evidence-based conservation decisions for endangered organisms. The red panda (Ailurus fulgens) is an endangered species distributing at the edge of the Qinghai-Tibetan Plateau and is currently subject to habitat loss, fragmentation and population decline, thus representing a good model to test the influences of the above-mentioned factors on a plateau edge species. We combined nine microsatellite loci and 551 bp of mitochondrial control region (mtDNA CR) to explore the genetic structure and demographic history of this species. A total of 123 individuals were sampled from 23 locations across five populations. High levels of genetic variation were identified for both mtDNA and microsatellites. Phylogeographic analyses indicated little geographic structure, suggesting historically wide gene flow. However, microsatellite-based Bayesian clustering clearly identified three groups (Qionglai-Liangshan, Xiaoxiangling and Gaoligong-Tibet). A significant isolation-by-distance pattern was detected only after removing Xiaoxiangling. For mtDNA data, there was no statistical support for a historical population expansion or contraction for the whole sample or any population except Xiaoxiangling where a signal of contraction was detected. However, Bayesian simulations of population history using microsatellite data did pinpoint population declines for Qionglai, Xiaoxiangling and Gaoligong, demonstrating significant influences of human activity on demography. The unique history of the Xiaoxiangling population plays a critical role in shaping the genetic structure of this species, and large-scale habitat loss and fragmentation is hampering gene flow among populations. The implications of our findings for the biogeography of the Qinghai-Tibetan Plateau, subspecies classification and

  5. 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.

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

    Science.gov (United States)

    Mondin, Lívia A. de Carvalho; Machado, Carolina B.; de Resende, Emiko K.; Marques, Debora K. S.; Galetti, Pedro M.

    2018-01-01

    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 Pleistocene interglacial

  7. 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

  8. Single-virion sequencing of lamivudine-treated HBV populations reveal population evolution dynamics and demographic history.

    Science.gov (United States)

    Zhu, Yuan O; Aw, Pauline P K; de Sessions, Paola Florez; Hong, Shuzhen; See, Lee Xian; Hong, Lewis Z; Wilm, Andreas; Li, Chen Hao; Hue, Stephane; Lim, Seng Gee; Nagarajan, Niranjan; Burkholder, William F; Hibberd, Martin

    2017-10-27

    Viral populations are complex, dynamic, and fast evolving. The evolution of groups of closely related viruses in a competitive environment is termed quasispecies. To fully understand the role that quasispecies play in viral evolution, characterizing the trajectories of viral genotypes in an evolving population is the key. In particular, long-range haplotype information for thousands of individual viruses is critical; yet generating this information is non-trivial. Popular deep sequencing methods generate relatively short reads that do not preserve linkage information, while third generation sequencing methods have higher error rates that make detection of low frequency mutations a bioinformatics challenge. Here we applied BAsE-Seq, an Illumina-based single-virion sequencing technology, to eight samples from four chronic hepatitis B (CHB) patients - once before antiviral treatment and once after viral rebound due to resistance. With single-virion sequencing, we obtained 248-8796 single-virion sequences per sample, which allowed us to find evidence for both hard and soft selective sweeps. We were able to reconstruct population demographic history that was independently verified by clinically collected data. We further verified four of the samples independently through PacBio SMRT and Illumina Pooled deep sequencing. Overall, we showed that single-virion sequencing yields insight into viral evolution and population dynamics in an efficient and high throughput manner. We believe that single-virion sequencing is widely applicable to the study of viral evolution in the context of drug resistance and host adaptation, allows differentiation between soft or hard selective sweeps, and may be useful in the reconstruction of intra-host viral population demographic history.

  9. 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.

  10. Genetic Pattern and Demographic History ofSalminus brasiliensis: Population Expansion in the Pantanal Region during the Pleistocene.

    Science.gov (United States)

    Mondin, Lívia A de Carvalho; Machado, Carolina B; de Resende, Emiko K; Marques, Debora K S; Galetti, Pedro M

    2018-01-01

    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 Pleistocene

  11. Effects of Pleistocene climatic fluctuations on the phylogeographic and demographic histories of Pacific herring (Clupea pallasii).

    Science.gov (United States)

    Liu, Jin-Xian; Tatarenkov, Andrey; Beacham, Terry D; Gorbachev, Victor; Wildes, Sharon; Avise, John C

    2011-09-01

    We gathered mitochondrial DNA sequences (557 bp from the control region in 935 specimens and 668 bp of the cytochrome b gene in 139 specimens) of Pacific herring collected from 20 nearshore localities spanning the species' extensive range along the North Pacific coastlines of Asia and North America. Haplotype diversity and nucleotide diversity were high, and three major phylogeographic lineages (sequence divergences ca. 1.5%) were detected. Using a variety of phylogenetic methods, coalescent reasoning, and molecular dating interpreted in conjunction with paleoclimatic and physiographic evidence, we infer that the genetic make-up of extant populations of C. pallasii was shaped by Pleistocene environmental impacts on the historical demography of this species. A deep genealogical split that cleanly distinguishes populations in the western vs. eastern North Pacific probably originated as a vicariant separation associated with a glacial cycle that drove the species southward and isolated two ancestral populations in Asia and North America. Another deep genealogical split may have involved either a vicariant isolation of a third herring lineage (perhaps originally in the Gulf of California) or it may have resulted simply from the long coalescent times that are possible in large populations. Coalescent analyses showed that all the three evolutionary lineages of C. pallasii experienced major expansions in their most recent histories after having remained more stable in the preceding periods. Independent of the molecular calibration chosen, populations of C. pallasii appear to have remained stable or grown throughout the periods that covered at least two major glaciations, and probably more. © 2011 Blackwell Publishing Ltd.

  12. Demographic history, genetic structure and gene flow in a steppe-associated raptor species

    Science.gov (United States)

    2011-01-01

    Background Environmental preferences and past climatic changes may determine the length of time during which a species range has contracted or expanded from refugia, thereby influencing levels of genetic diversification. Connectivity among populations of steppe-associated taxa might have been maximal during the long glacial periods, and interrupted only during the shorter interglacial phases, potentially resulting in low levels of genetic differentiation among populations. We investigated this hypothesis by exploring patterns of genetic diversity, past demography and gene flow in a raptor species characteristic of steppes, the Montagu's harrier (Circus pygargus), using mitochondrial DNA data from 13 breeding populations and two wintering populations. Results Consistent with our hypothesis, Montagu's harrier has relatively low genetic variation at the mitochondrial DNA. The highest levels of genetic diversity were found in coastal Spain, France and central Asia. These areas, which were open landscapes during the Holocene, may have acted as refugia when most of the European continent was covered by forests. We found significant genetic differentiation between two population groups, at the SW and NE parts of the species' range. Two events of past population growth were detected, and occurred ca. 7500-5500 and ca. 3500-1000 years BP in the SW and NE part of the range respectively. These events were likely associated with vegetation shifts caused by climate and human-induced changes during the Holocene. Conclusions The relative genetic homogeneity observed across populations of this steppe raptor may be explained by a short isolation time, relatively recent population expansions and a relaxed philopatry. We highlight the importance of considering the consequence of isolation and colonization processes in order to better understand the evolutionary history of steppe species. PMID:22093489

  13. Demographic history, genetic structure and gene flow in a steppe-associated raptor species

    Directory of Open Access Journals (Sweden)

    Garcia Jesus T

    2011-11-01

    Full Text Available Abstract Background Environmental preferences and past climatic changes may determine the length of time during which a species range has contracted or expanded from refugia, thereby influencing levels of genetic diversification. Connectivity among populations of steppe-associated taxa might have been maximal during the long glacial periods, and interrupted only during the shorter interglacial phases, potentially resulting in low levels of genetic differentiation among populations. We investigated this hypothesis by exploring patterns of genetic diversity, past demography and gene flow in a raptor species characteristic of steppes, the Montagu's harrier (Circus pygargus, using mitochondrial DNA data from 13 breeding populations and two wintering populations. Results Consistent with our hypothesis, Montagu's harrier has relatively low genetic variation at the mitochondrial DNA. The highest levels of genetic diversity were found in coastal Spain, France and central Asia. These areas, which were open landscapes during the Holocene, may have acted as refugia when most of the European continent was covered by forests. We found significant genetic differentiation between two population groups, at the SW and NE parts of the species' range. Two events of past population growth were detected, and occurred ca. 7500-5500 and ca. 3500-1000 years BP in the SW and NE part of the range respectively. These events were likely associated with vegetation shifts caused by climate and human-induced changes during the Holocene. Conclusions The relative genetic homogeneity observed across populations of this steppe raptor may be explained by a short isolation time, relatively recent population expansions and a relaxed philopatry. We highlight the importance of considering the consequence of isolation and colonization processes in order to better understand the evolutionary history of steppe species.

  14. Demographic history, genetic structure and gene flow in a steppe-associated raptor species.

    Science.gov (United States)

    Garcia, Jesus T; Alda, Fernando; Terraube, Julien; Mougeot, François; Sternalski, Audrey; Bretagnolle, Vincent; Arroyo, Beatriz

    2011-11-17

    Environmental preferences and past climatic changes may determine the length of time during which a species range has contracted or expanded from refugia, thereby influencing levels of genetic diversification. Connectivity among populations of steppe-associated taxa might have been maximal during the long glacial periods, and interrupted only during the shorter interglacial phases, potentially resulting in low levels of genetic differentiation among populations. We investigated this hypothesis by exploring patterns of genetic diversity, past demography and gene flow in a raptor species characteristic of steppes, the Montagu's harrier (Circus pygargus), using mitochondrial DNA data from 13 breeding populations and two wintering populations. Consistent with our hypothesis, Montagu's harrier has relatively low genetic variation at the mitochondrial DNA. The highest levels of genetic diversity were found in coastal Spain, France and central Asia. These areas, which were open landscapes during the Holocene, may have acted as refugia when most of the European continent was covered by forests. We found significant genetic differentiation between two population groups, at the SW and NE parts of the species' range. Two events of past population growth were detected, and occurred ca. 7500-5500 and ca. 3500-1000 years BP in the SW and NE part of the range respectively. These events were likely associated with vegetation shifts caused by climate and human-induced changes during the Holocene. The relative genetic homogeneity observed across populations of this steppe raptor may be explained by a short isolation time, relatively recent population expansions and a relaxed philopatry. We highlight the importance of considering the consequence of isolation and colonization processes in order to better understand the evolutionary history of steppe species.

  15. 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.

  16. Leading and trailing edges of moving plates record contrasting thermal, mechanical, tectonic and stratigraphic histories

    Science.gov (United States)

    Bodur, O. F.; Rey, P. F.; Müller, D.

    2017-12-01

    At the transition between thick continental plates and thinner adjacent oceanic plates, the deep-seated corner of the related lithospheric mantle step is exposed to thermomechanical erosion during plate motion, and lateral variations in lithospheric thickness and temperature at these regions initiate a corner flow. Here, we present a suite of thermomechanical numerical experiments to document and characterize the mechanical and thermal evolution of the trailing and leading edge of a moving plate. We show that the geometry of the trailing and leading margins of plates evolve by a combination of thermomechanical accretion or erosion, respectively. This drives subsidence and uplift, part of which is dynamically driven by the mantle flow, and the remainder is an isostatic response to the change in structure and/or temperature of the margins. Interestingly, leading and trailing edges record contrasting tectonic histories with magnitudes of extension/contraction measurable after tens of million years of plate motion. Our numerical experiments predict different sediment supply and accommodation space, along with different tectonics and heat flow for different margins during sedimentation. These suggest that measurable differences in tectonics and stratigraphy should exist between the trailing and leading margins of moving continents. This new modelling approach will provide new insights into fundamental differences in the evolution of Australian passive margin basins regarding their subsidence, thermal evolution and stratigraphy depending on their location along the southern, trailing edge or the northern leading edge of the continent.

  17. The contribution of parental smoking history and socio-demographic factors to the smoking behavior of Israeli women.

    Science.gov (United States)

    Segal-Engelchin, Dorit; Friedmann, Enav; Cwikel, Julie G

    2014-01-01

    This study examined the interplay between sociodemographic factors and parental smoking history in shaping the smoking behavior of Israeli women (N = 302). The study was conducted in the Negev region, which is characterized by a high proportion of immigrants and high percentage of low socioeconomic and educational groups. The specific objectives of this study were to examine: (1) The prevalence and characteristics of women smokers, ex-smokers and never-smokers; and (2) the contribution of education and parent smoking history to women's current smoking. Low levels of education, being Israeli born or veteran immigrants of European-American origin significantly increased the risk of smoking, whereas an orthodox lifestyle and new immigrant status significantly reduced the likelihood of smoking. Occasional smokers reported significantly higher primary care utilization than never smokers. A significant relationship between smoking and pain, gynecological symptoms and depression was found. Results indicate that childhood exposure to maternal smoking was a significant risk factor for smoking, whereas paternal past smoking negatively affects smoking in women. Also, results show that parental educational level affects women's smoking behavior indirectly by influencing their own educational attainment, which in turn is negatively associated with the likelihood of smoking. Mothers with higher education were more likely to smoke, an effect that was reversed for their daughters. Our results demonstrate how demographic, parental and lifestyle factors affect women's smoking in a multi-ethnic society and highlight the need to examine both generational and intergenerational effects.

  18. 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.

  19. 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.

  20. 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.

  1. [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)).

  2. 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

  3. Phylogeographic structure, cryptic speciation and demographic history of the sharpbelly (Hemiculter leucisculus), a freshwater habitat generalist from southern China.

    Science.gov (United States)

    Chen, Weitao; Zhong, Zaixuan; Dai, Wei; Fan, Qi; He, Shunping

    2017-09-12

    Species with broad distributions frequently divide into multiple genetic forms and may therefore be viewed as "cryptic species". Here, we used the mitochondrial cytochrome b (Cytb) and 12 nuclear DNA loci to investigate phylogeographic structures of the sharpbelly (Hemiculter leucisculus) in rivers in southern China and explored how the geological and climatic factors have shaped the genetic diversity and evolutionary history of this species. Our mitochondrial phylogenetic analysis identified three major lineages (lineages A, B, and C). Lineages B and C showed a relatively narrower geographic distribution, whereas lineage A was widely distributed in numerous drainages. Divergence dates suggested that H. leucisculus populations diverged between 1.61-2.38 Ma. Bayesian species delimitation analysis using 12 nuclear DNA loci indicated the three lineages probably represented three valid taxa. Isolation-with-migration (IM) analysis found substantial gene flow has occurred among the three lineages. Demographic analyses showed that lineages B and C have experienced rapid demographic expansion at 0.03 Ma and 0.08 Ma, respectively. Hemiculter leucisculus populations in drainages in southern China comprise three mtDNA lineages, and each of which may represent a separate species. Intense uplift of the Qinghai-Tibetan Plateau, evolution of Asian monsoons, changes in paleo-drainages, and poor dispersal ability may have driven the divergence of the three putative species. However, gene flow occurs among the three lineages. Climatic fluctuations have a prominent impact on the populations from the lineages B and C, but exerted little influence on the lineage A.

  4. 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.

  5. Gene flow and demographic history of the mangrove crab Neosarmatium meinerti: A case study from the western Indian Ocean

    Science.gov (United States)

    Ragionieri, Lapo; Cannicci, Stefano; Schubart, Christoph D.; Fratini, Sara

    2010-01-01

    Most marine organisms are characterized by at least one planktonic phase during their life history, potentially allowing interconnection of populations separated by several hundred kilometers. For many years, the idea that marine species are genetically homogenous throughout their range of distribution, due to passive larval transport, has been a paradigm. Nowadays, a growing number of studies underline the existence of boundaries in the marine realm and highlight how larval dispersal is a complex process depending on biotic as well as abiotic factors. Marine fragmented habitats, such as atolls, mangroves and estuaries, are optimal systems for investigating the marine dispersion process under a metapopulation approach, since populations can be geographically defined a priori as opposed to those occupying open marine environments. Within this frame, the present paper investigates the population genetic structure and the demographic history of the mangrove crab Neosarmatium meinerti within the western Indian Ocean by partial sequences of the mitochondrial DNA cytochrome oxidase subunit I. A total of 167 specimens were sampled from six mangrove sites distributed along the East African coast, from Kenya to South Africa, also including a mangrove forest located on Mahé Island, Seychelles. A sharp genetic break between the mainland and the Seychelles is recorded, revealing the existence of two historically distinct groups that can be defined as independent evolutionary units. Gene flow along the East African coast appears to be high enough to form a single metapopulation, probably by means of stepping stone populations. Otherwise, this mainland metapopulation is currently under expansion through a gradual moving front from the subtropical toward the equatorial populations.

  6. Older prisoners: psychological distress and associations with mental health history, cognitive functioning, socio-demographic, and criminal justice factors.

    Science.gov (United States)

    Baidawi, Susan

    2016-03-01

    The growth among older prisoner populations, including in Australia, necessitates an understanding of this group in order to generate effective management strategies. One particular concern is the mental well-being of older prisoners. This study aimed to determine the level of psychological distress among sentenced prisoners aged 50 years and older, to compare this level to that seen among younger prisoners and older people in the community, and to investigate which mental health history, cognitive functioning, socio-demographic, and criminal justice characteristics were associated with psychological distress. A cross-sectional survey of 173 older (M = 63 years) and 60 younger prisoners (M = 34 years) in two Australian jurisdictions was conducted. The Kessler Psychological Distress (K10) scale was administered with prisoners and additional data were collected from interviews and participant health and corrections files. K10 scores were compared to community norms using data from the Australian Health Survey. Average K10 scores of the older prisoners were significantly lower than the younger prisoners' (p = 0.04), though the effect size was small (r = 0.1). Significantly, higher distress levels were observed in comparison to the general population (p prisoners being three times more likely to display very high levels of distress (12.3% vs. 3.7%). Higher psychological distress scores among older prisoners were significantly associated with female gender (p = 0.002) and a history of mental health issues (p = 0.002). While the levels of distress seen among older prisoners were significantly lower than that of younger prisoners, their higher levels of distress in comparison to community norms demonstrate a need for correctional services to be attuned to the mental health of the expanding older prisoner population.

  7. 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

  8. Low genetic diversity in wide-spread Eurasian liver fluke Opisthorchis felineus suggests special demographic history of this trematode species.

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    Ilja I Brusentsov

    Full Text Available 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.

  9. 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.

  10. Genetic structure and demographic history should inform conservation: Chinese cobras currently treated as homogenous show population divergence.

    Directory of Open Access Journals (Sweden)

    Long-Hui Lin

    Full Text Available An understanding of population structure and genetic diversity is crucial for wildlife conservation and for determining the integrity of wildlife populations. The vulnerable Chinese cobra (Naja atra has a distribution from the mouth of the Yangtze River down to northern Vietnam and Laos, within which several large mountain ranges and water bodies may influence population structure. We combined 12 microsatellite loci and 1117 bp of the mitochondrial cytochrome b gene to explore genetic structure and demographic history in this species, using 269 individuals from various localities in Mainland China and Vietnam. High levels of genetic variation were identified for both mtDNA and microsatellites. mtDNA data revealed two main (Vietnam + southern China + southwestern China; eastern + southeastern China and one minor (comprising only two individuals from the westernmost site clades. Microsatellite data divided the eastern + southeastern China clade further into two genetic clusters, which include individuals from the eastern and southeastern regions, respectively. The Luoxiao and Nanling Mountains may be important barriers affecting the diversification of lineages. In the haplotype network of cytchrome b, many haplotypes were represented within a "star" cluster and this and other tests suggest recent expansion. However, microsatellite analyses did not yield strong evidence for a recent bottleneck for any population or genetic cluster. The three main clusters identified here should be considered as independent management units for conservation purposes. The release of Chinese cobras into the wild should cease unless their origin can be determined, and this will avoid problems arising from unnatural homogenization.

  11. Ecosystem Carbon Budgets under Contrasting Land Use Histories Using Eddy Covariance and Deep Core Methods

    Science.gov (United States)

    Abraha, M.; Gelfand, I.; Hamilton, S. K.; Shao, C.; Su, Y. J.; Robertson, G. P.; Chen, J.

    2016-12-01

    Increasing demand for agricultural production could be met through conversion of uncultivated lands and/or intensification of production on existing agricultural lands, each with distinct implications for ecosystem carbon budgets. We investigated the carbon budget of two intensively managed continuous no-till corn fields with contrasting land use histories over six years using eddy covariance (EC) and deep core methods. One treatment had been managed as Conservation Reserve Program (CRP) grassland for 22 years before conversion, thus representing conversion of uncultivated lands into agriculture, and the other treatment had been managed as conventional agriculture (AGR) in a corn-soybean rotation for several decades before conversion, thus representing agricultural intensification. We hypothesized that the AGR land would sequester more carbon or at least remain neutral owing to the reduced soil disturbance and increased overall productivity of the land following conversion. Accordingly, we expected soil carbon to either increase or remain unchanged compared to its pre-conversion status. We also hypothesized that the CRP grassland converted to no-till would lose carbon to the atmosphere until a new equilibrium is reached owing to the decomposition of the large below- and above-ground plant biomass and soil organic matter that had accumulated during the 22 years of CRP management. Consequently, we anticipated the soil carbon to decrease compared to its pre-conversion status. The EC-derived carbon budget supported our hypothesis in that the former AGR land was on average carbon neutral (-8 g C m-2 yr-1) while the former CRP land emitted 301 g C m-2 yr-1 to the atmosphere over the six year period. In contradiction to the hypothesis, the deep core method indicated that the former AGR land emitted 167 g C m-2 yr-1 to the atmosphere while the former CRP land sequestered 127 g C m-2 yr-1 over the same time period. This could be due to pre-conversion plant biomass and soil

  12. 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

  13. Contrast enhanced ultrasound of a gallbladder lesion in a patient with a history of renal cell and rectal cancer.

    Science.gov (United States)

    Reiser, Markus; Oehmen, Frank; Walter, Hajo; Büsing, Martin

    2013-01-01

    The gallbladder is an uncommon site of metastatic cancer. Although ultrasound can be regarded as a first line investigation for the detection of gallbladder lesions, differentiation between benign and malignant tumors usually requires resection. Real-time contrast enhanced ultrasound (CEUS) is a well-established technique for the classification of liver, pancreatic, and renal diseases (Weskott, 2008). The application of CEUS in the diagnosis of gallbladder tumors has rarely been described. We report the application of contrast enhanced ultrasound for the characterization of a gallbladder lesion in a 63-year-old patient with a history of renal cell and rectal cancer.

  14. 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

  15. Inferring Individual Inbreeding and Demographic History from Segments of Identity by Descent inFicedulaFlycatcher Genome Sequences.

    Science.gov (United States)

    Kardos, Marty; Qvarnström, Anna; Ellegren, Hans

    2017-03-01

    Individual inbreeding and historical demography can be estimated by analyzing runs of homozygosity (ROH), which are indicative of chromosomal segments of identity by descent (IBD). Such analyses have so far been rare in natural populations due to limited genomic resources. We analyzed ROH in whole genome sequences from 287 Ficedula flycatchers representing four species, with the objectives of evaluating the causes of genome-wide variation in the abundance of ROH and inferring historical demography. ROH were clearly more abundant in genomic regions with low recombination rate. However, this pattern was substantially weaker when ROH were mapped using genetic rather than physical single nucleotide polymorphism (SNP) coordinates in the genome. Empirical results and simulations suggest that high ROH abundance in regions of low recombination was partly caused by increased power to detect the very long IBD segments typical of regions with a low recombination rate. Simulations also showed that hard selective sweeps (but not soft sweeps or background selection) likely contributed to variation in the abundance of ROH across the genome. Comparisons of the abundance of ROH among several study populations indicated that the Spanish pied flycatcher population had the smallest historical effective population size ( N e ) for this species, and that a putatively recently founded island (Baltic) population had the smallest historical N e among the collared flycatchers. Analysis of pairwise IBD in Baltic collared flycatchers indicated that this population was founded <60 generations ago. This study provides a rare genomic glimpse into demographic history and the mechanisms underlying the genome-wide distribution of ROH. Copyright © 2017 by the Genetics Society of America.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. 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.

  19. 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

    OpenAIRE

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

    2014-01-01

    Background: 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. Methods: Two hundred seventy six psychiatric outpatients (154 suicide attempters and 122 patients without suicide attempt history) attended the two public hospitals in Durango City, Me...

  20. 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.

  1. Injury History in the Collegiate Equestrian Athlete: Part I: Mechanism of Injury, Demographic Data and Spinal Injury

    Directory of Open Access Journals (Sweden)

    Michael L. Pilato

    2017-04-01

    Full Text Available Purpose: Equestrian sports are known to have a high risk and rate of injury. While there is injury data available on acute injuries in the equestrian population, it is of a general nature. Within that data appears to be a lack of information on the collegiate equestrian athlete. Thus, the purpose of the current study and this analysis is to describe the demographics and incidence of spinal injuries found in intercollegiate equestrian athlete. Method: A survey was developed with input from each author and implemented in Mach forms. It was sent to 43 equestrian coaches in the Eastern United States who passed it on to their athletes. We estimated 753 athletes would have access to the survey and had a total of 73 respondents. Descriptive statistics were calculated for total number of injuries for each injury category. Results: Demographic information, conditioning activity, riding style, pain medication use, total responses (injuries per body area and injuries to the spine and pelvis are detailed in tables 1-6. Of interesting note is only 73% of respondents reported having access to or utilizing the schools athletic program as part of their participation on the schools equestrian team. Conclusions and Recommendations: The current study is amongst the first, if not the first, to report specifically on injury patterns and frequency in US collegiate equestrian athletes. There were several findings that from a sports medicine and athletic perspective are concerning. The lack of overall knowledge and research about the equestrian athlete would appear to put it in the same position as cheerleading was 20 years ago. Significantly more sport specific research is needed to improve the health and safety of the athletes.

  2. 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) (Psuicide attempts were associated with young age (OR=1.21, 95% CI: 1.06-1.39; P=0.003), female gender (OR=2.98, 95% CI: 1.55-5.73; P=0.001), urban 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; Psuicide attempts with socio-demographic, clinical and behavioral characteristics in psychiatric outpatients in Mexico. Results may be useful for an optimal planning of preventive measures against suicide attempts in psychiatric outpatients.

  3. 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

  4. Human paternal and maternal demographic histories: insights from high-resolution Y chromosome and mtDNA sequences.

    Science.gov (United States)

    Lippold, Sebastian; Xu, Hongyang; Ko, Albert; Li, Mingkun; Renaud, Gabriel; Butthof, Anne; Schröder, Roland; Stoneking, Mark

    2014-01-01

    Comparisons of maternally-inherited mitochondrial DNA (mtDNA) and paternally-inherited non-recombining Y chromosome (NRY) variation have provided important insights into the impact of sex-biased processes (such as migration, residence pattern, and so on) on human genetic variation. However, such comparisons have been limited by the different molecular methods typically used to assay mtDNA and NRY variation (for example, sequencing hypervariable segments of the control region for mtDNA vs. genotyping SNPs and/or STR loci for the NRY). Here, we report a simple capture array method to enrich Illumina sequencing libraries for approximately 500 kb of NRY sequence, which we use to generate NRY sequences from 623 males from 51 populations in the CEPH Human Genome Diversity Panel (HGDP). We also obtained complete mtDNA genome sequences from the same individuals, allowing us to compare maternal and paternal histories free of any ascertainment bias. We identified 2,228 SNPs in the NRY sequences and 2,163 SNPs in the mtDNA sequences. Our results confirm the controversial assertion that genetic differences between human populations on a global scale are bigger for the NRY than for mtDNA, although the differences are not as large as previously suggested. More importantly, we find substantial regional variation in patterns of mtDNA versus NRY variation. Model-based simulations indicate very small ancestral effective population sizes (<100) for the out-of-Africa migration as well as for many human populations. We also find that the ratio of female effective population size to male effective population size (Nf/Nm) has been greater than one throughout the history of modern humans, and has recently increased due to faster growth in Nf than Nm. The NRY and mtDNA sequences provide new insights into the paternal and maternal histories of human populations, and the methods we introduce here should be widely applicable for further such studies.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Tropical specialist vs. climate generalist: Diversification and demographic history of sister species of Carlia skinks from northwestern Australia.

    Science.gov (United States)

    Afonso Silva, Ana C; Bragg, Jason G; Potter, Sally; Fernandes, Carlos; Coelho, Maria Manuela; Moritz, Craig

    2017-08-01

    Species endemic to the tropical regions are expected to be vulnerable to future climate change due in part to their relatively narrow climatic niches. In addition, these species are more likely to have responded strongly to past climatic change, and this can be explored through phylogeographic analyses. To test the hypothesis that tropical specialists are more sensitive to climate change than climate generalists, we generated and analyse sequence data from mtDNA and ~2500 exons to compare scales of historical persistence and population fluctuation in two sister species of Australian rainbow skinks: the tropical specialist Carlia johnstonei and the climate generalist C. triacantha. We expect the tropical specialist species to have deeper and finer-scale phylogeographic structure and stronger demographic fluctuations relative to the closely related climate generalist species, which should have had more stable populations through periods of harsh climate in the late Quaternary. Within C. johnstonei, we find that some populations from the northern Kimberley islands are highly divergent from mainland populations. In C. triacantha, one major clade occurs across the deserts and into the mesic Top End, and another occurs primarily in the Kimberley with scattered records eastwards. Where their ranges overlap in the Kimberley, both mitochondrial DNA and nuclear DNA suggest stronger phylogeographic structure and range expansion within the tropical specialist, whereas the climate generalist has minimal structuring and no evidence of recent past range expansion. These results are consistent with the hypothesis that tropical specialists are more sensitive to past climatic change. © 2017 John Wiley & Sons Ltd.

  7. Marine sponges with contrasting life histories can be complementary biomonitors of heavy metal pollution in coastal ecosystems.

    Science.gov (United States)

    Batista, Daniela; Muricy, Guilherme; Rocha, Rafael Chávez; Miekeley, Norbert F

    2014-05-01

    In this study, we compared the usefulness of a long-living sponge (Hymeniacidon heliophila, Class Demospongiae) and a short-living one (Paraleucilla magna, Class Calcarea) as biomonitors of metallic pollution. The concentrations of 16 heavy metals were analyzed in both species along a gradient of decreasing pollution from the heavily polluted Guanabara Bay to the less impacted coastal islands in Rio de Janeiro, SE Brazil (SW Atlantic). The levels of most elements analyzed were higher in H. heliophila (Al, Co, Cr, Cu, Fe, Mn, Ni, Hg, Ni, and Sn) and P. magna (Ni, Cu, Mn, Al, Ti, Fe, Pb, Co, Cr, Zn, and V) collected from the heavily polluted bay when compared with the cleanest sites. Hymeniacidon heliophila accumulates 11 elements more efficiently than P. magna. This difference may be related to their skeleton composition, histological organization, symbiont bacteria and especially to their life cycle. Both species can be used as a biomonitors of metallic pollution, but while Hymeniacidon heliophila was more effective in concentrating most metals, Paraleucilla magna is more indicated to detect recent pollutant discharges due to its shorter life cycle. We suggest that the complementary use of species with contrasting life histories can be an effective monitoring strategy of heavy metals in coastal environments.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. Pregnancy history and current use of contraception among women of reproductive age in Burundi, Kenya, Rwanda, Tanzania and Uganda: analysis of demographic and health survey data.

    Science.gov (United States)

    Bakibinga, Pauline; Matanda, Dennis J; Ayiko, Rogers; Rujumba, Joseph; Muiruri, Charles; Amendah, Djesika; Atela, Martin

    2016-03-10

    To examine the relationship between pregnancy history and the use of contraception among women of reproductive age (15-49 years) in East Africa. Demographic and Health Surveys data from Burundi (2010), Kenya (2008-2009), Rwanda (2010), Tanzania (2010) and Uganda (2011) were used in the analysis. Logistic regression was used to determine the effects of women's pregnancy history on their use of contraception. Burundi, Kenya, Rwanda, Tanzania and Uganda. 3226, 2377, 4396, 3250 and 2596 women of reproductive age (15-49 years) from Burundi, Kenya, Rwanda, Tanzania and Uganda, respectively, were included in the analysis. Women who had experienced a mistimed pregnancy were more likely to use a modern contraceptive method during their most recent sexual encounter in Kenya, Rwanda, Burundi and Uganda. Other significant correlates of women's contraceptive use were: desire for more children, parity, household wealth, maternal education and access information through radio. In-country regional differences on use of modern contraceptive methods were noted across five East African countries. Women's birth histories were significantly associated with their decision to adopt a modern contraceptive method. This highlights the importance of considering women's birth histories, especially women with mistimed births, in the promotion of contraceptive use in East Africa. Variations as a result of place of residency, educational attainment, access to family planning information and products, and wealth ought to be addressed in efforts to increase use of modern contraceptive methods in the East African region. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  14. 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.

  15. Evolutionary history of a widespread Indo-Pacific goby: the role of Pleistocene sea-level changes on demographic contraction/expansion dynamics.

    Science.gov (United States)

    Hoareau, Thierry Bernard; Boissin, Emilie; Berrebi, Patrick

    2012-01-01

    Compared to endemics, widespread species are of particular interest to retrace recent evolutionary history. These species have a large population size which provides a clearer genetic signature of past events. Moreover, their wide geographic range increases the potential occurrence of evolutionary events (expansion, divergence, etc.). Here, we used several coalescent-based methods to disentangle the evolutionary history of a widespread amphidromous goby (Sicyopterus lagocephalus), in the light of sea-level variations during the Pleistocene. Using 75 samples recovered from three biogeographic regions (Western Indian Ocean, Melanesia and Polynesia), we analysed a portion of the cytochromeb gene and confirmed three major haplogroups, each specific to a region. Furthermore, we found that: (1) the Melanesian haplogroup was the oldest while the two peripheral regions hosted daughter haplogroups; (2) two centrifugal colonisation events occurred from Melanesia to the periphery, each synchronised with periods of strong paleo-ENSO episodes; (3) the demographic contraction-expansion events were linked to Pleistocene sea-level changes; (4) Melanesia and Polynesia acted as efficient refuges during the Last Glacial Maximum. These results highlight the importance of studying widespread species to better understand the role of climate changes and paleo-oceanography on the evolution of biodiversity. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Demographic study of port wine stain patients attending a laser clinic: family history, prevalence of naevus anaemicus and results of prior treatment.

    Science.gov (United States)

    Mills, C M; Lanigan, S W; Hughes, J; Anstey, A V

    1997-07-01

    All patients with port wine stains (PWS) attending a tunable dye laser clinic were examined by one author (SWL), forming a large group which has allowed study of the demographic data of such patients. Two hundred and eighty-three patients, 217 females (median age 24 years, range 0.5-73) and 66 males (median age 20 years, range 0.75-72), were examined. The PWS were on the face in 226, neck in 69, trunk in 36, upper limb in 35 and lower limb in 29. The commonest lesional colour was purple (63 patients), while 39 naevi were pink/red, 35 pink/ purple and 35 pink. The naevus was flat in 255 patients, cobblestoned in 28, associated with hypertrophy in 31 and with scarring in 22. Seventy-two patients (25.4%) had a positive family history of birthmarks, 20 strawberry haemangiomas and 22 PWS, the family history of PWS being higher than expected for the prevalence of this naevus in the population. One hundred and forty-six patients were also examined for naevus anaemicus which was noted in 12 (8.2%), confirming an association between these two naevi. Ninety-four patients had received previous treatment, most commonly with the argon laser (56 patients), of whom only five reported a good result, and 17 of 22 patients with treatment-related scarring had been treated with this laser. Cosmetic camouflage was used in 109 (38.5%) of patients, who usually had PWS on the face (94%), of whom only 46 (16%) had received advice of its use.

  17. Ecocardiografía de contraste: historia, características de las microburbujas y técnicas instrumentales Contrast echocardiography: history, micro bubble characteristics and instrumental techniques

    Directory of Open Access Journals (Sweden)

    Carlos Cubides

    Full Text Available Este artículo describe la historia de la ecocardiografía de contraste, las características físicas de las microburbujas de los agentes de contraste, las principales herramientas instrumentales (índice mecánico, foco y enfoque, número de imágenes por segundo y las técnicas ecocardiográficas (segunda armónica, armónica de fusión, segunda armónica de pulso invertido, imagen intermitente, angio y densitometría acústica actualmente disponibles para uso clínico.This article describes the history of contrast echocardiography, the physical characteristics of the contrast agents’ 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.

  18. 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.

  19. 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

  20. 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

  1. Socio-demographic factors, reproductive history and risk of osteoarthritis in a cohort of 4.6 million Danish women and men

    DEFF Research Database (Denmark)

    Jørgensen, K T; Pedersen, B V; Nielsen, N M

    2011-01-01

    Studies addressing possible socio-demographic and reproductive factors in the aetiology of osteoarthritis (OA) are few. We studied possible influences of educational level, household income, marital status and parenting patterns on OA risk overall and at anatomical sites.......Studies addressing possible socio-demographic and reproductive factors in the aetiology of osteoarthritis (OA) are few. We studied possible influences of educational level, household income, marital status and parenting patterns on OA risk overall and at anatomical sites....

  2. 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

  3. Early development of congeneric sea urchins (Heliocidaris) with contrasting life history modes in a warming and high CO2 ocean.

    Science.gov (United States)

    Hardy, Natasha A; Byrne, Maria

    2014-12-01

    The impacts of ocean change stressors - warming and acidification - on marine invertebrate development have emerged as a significant impact of global change. We investigated the response of early development to the larval stage in sympatric, congeneric sea urchins, Heliocidaris tuberculata and Heliocidaris erythrogramma with contrasting modes of development to ocean warming and acidification. Effects of these stressors were assessed by quantifying the percentage of normal development during the first 24 h post fertilization, in cross-factorial experiments that included three temperature treatments (control: 20 °C; +4: 24 °C; +6: 26 °C) and four pHNIST levels (control: 8.2; -0.4: 7.8; -0.6: 7.6; -0.8: 0.4). The experimental treatments were designed in context with present day and near-future (∼2100) conditions for the southeast Australia global warming hotspot. Temperature was the most important factor affecting development of both species causing faster progression through developmental stages as well as a decrease in the percentage of normal development. H. erythrogramma embryos were less tolerant of increased temperature than those of H. tuberculata. Acidification impaired development to the larval stage in H. tuberculata, but this was not the case for H. erythrogramma. Thus, outcomes for the planktonic life phase of the two Heliocidaris species in response to ocean warming and acidification will differ. As shown for these species, single-stressor temperature or acidification studies can be misleading with respect to determining species' vulnerability and responses to global change. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. 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

  5. Microsatellite DNA analysis of northern pike ( Esox lucius L.) populations: insights into the genetic structure and demographic history of a genetically depauperate species

    DEFF Research Database (Denmark)

    Jacobsen, B. H.; Hansen, Michael Møller; Loeschcke, V.

    2005-01-01

    and southern European populations were highly distinct. A population from Ireland was monomorphic at all loci, presumably reflecting founder events associated with introduction of the species to the island in the sixteenth century. Bayesian analysis of demographic parameters showed differences in theta (a...

  6. [Retention of contrast media in the history of radiology : Sequelae of the former use of thorotrast and new challenges].

    Science.gov (United States)

    van Kaick, G; Delorme, S

    2016-12-01

    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.

  7. 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.

  8. 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.

  9. 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

  10. DEMOGRAPHIC TRANSITION AND DEMOGRAPHIC PROBLEM IN BULGARIA

    Directory of Open Access Journals (Sweden)

    Krasimir Levkov

    2017-12-01

    Full Text Available The demographic problem is a topical issue for the Bulgarian society. It is the result of a long socio-economic process that began in the 1920s. The author agrees that the solution of the demographic problem depends both on the correct demographic policy of the state and on the conscious demographic behavior of each of its citizens.

  11. Contrasts & Connections: Teachers' Resource Book, Second Edition for the Revised National Curriculum. The Schools History Project, "Discovering the Past Y7."

    Science.gov (United States)

    Shephard, Colin; Corbishley, Mike; Large, Alan; Tames, Richard

    This history course has been designed by the Schools History Project for the national curriculum in England. It covers three study units for the revised curriculum, including: (1) the Roman Empire as a study of an era or turning point in European history before 1914; (2) Medieval Realms as a statutory unit; and (3) Islamic Civilizations as a study…

  12. 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.

  13. Contrasting cooling and exhumation histories of tectonic blocks in the eastern part of the Eastern Alps and its possible relationships with lithospheric dynamics

    Science.gov (United States)

    Wölfler, Andreas; Glotzbach, Christoph

    2017-04-01

    In the European Alps two fundamental changes in the lithospheric structure controlled the geodynamic evolution of the orogen: (1) Late Eocene to Early Oligocene rupturing of the European slab and (2) Early Miocene change in subduction polarity between the Western and Eastern Alps. In particular, the eastern part of the Eastern Alps is a key area which will provide both, information about the surface response to the Eocene/Oligocene slab breakoff and the response to a proposed isostatic rebound due to slab detachment of the European lithosphere in the Miocene (Handy et al., 2015). The eastern part of the Eastern Alps is characterized by fault-bounded blocks with different thermochronological ages, mean elevations and hillslope angles, indicating a variable spatial and temporal evolution throughout the Cenozoic era. The topographic pattern of the study area can be described in terms of (1) high relief with a rugged surface and steep slopes in the Niedere Tauern and (2) lower relief and distinctly smoother topography in the Seckauer Tauern, the Gurktal, Saualpe and Koralpe blocks. Generally, tectonic blocks with higher relief and rugged topography display the youngest apatite fission track (AFT) and apatite (U-Th)/He data (AHe); the Niedere Tauern concurs with middle Miocene AFT and late Miocene/Pliocene AHe ages (Wölfler et al., 2016). The other tectonic blocks generally show Eocene to Oligocene AFT ages (Wölfler et al., 2016 and references therein) and Oligocene to early Miocene AHe ages (Legrain et al., 2014, own preliminary work). New AFT and AHe data from the Gurktal block and Seckauer Tauern indicate that substantial parts of the study area where at near-surface conditions since the Eocene and Oligocene. Thermal history models suggest fast cooling through the AFT and AHe closure temperatures in the Oligocene as a possible response to slab breakoff that was followed by thermal stagnation until the present. In contrast, the neighboring Niedere Tauern experienced

  14. Establishing and implementing Demographic Surveillance System ...

    African Journals Online (AJOL)

    Demographic, social economic status, immunisation coverage and birth history data was collected during the follow-up and each household was visited every 4 months. Estimates of mortality levels were derived from deaths that were collected during household visits. Birth history data were used to estimate the lifetime and ...

  15. 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.

  16. Contrasting patterns of genetic diversity across the ranges of Pinus monticola and P. strobus: a comparison between eastern and western North American postglacial colonization histories.

    Science.gov (United States)

    Nadeau, Simon; Godbout, Julie; Lamothe, Manuel; Gros-Louis, Marie-Claude; Isabel, Nathalie; Ritland, Kermit

    2015-08-01

    • Premises of the study: Understanding the influence of recent glacial and postglacial periods on species' distributions is key for predicting the effects of future environmental changes. We investigated the influence of two physiographic landscapes on population structure and postglacial colonization of two white pine species of contrasting habitats: P. monticola, which occurs in the highly mountainous region of western North America, and P. strobus, which occurs in a much less mountainous area in eastern North America.• To characterize the patterns of genetic diversity and population structure across the ranges of both species, 158 and 153 single nucleotide polymorphism (SNP) markers derived from expressed genes were genotyped on range-wide samples of 61 P. monticola and 133 P. strobus populations, respectively.• In P. monticola, a steep latitudinal decrease in genetic diversity likely resulted from postglacial colonization involving rare long-distance dispersal (LDD) events. In contrast, no geographic patterns of diversity were detected in P. strobus, suggesting recolonization via a gradually advancing front or frequent LDD events. For each species, structure analyses identified two distinct southern and northern genetic groups that likely originated from two different glacial lineages. At a finer scale, and for the two species, smaller subgroups were detected that could be remnants of cryptic refugia.• During postglacial colonization, the western and eastern North American landscapes had different impacts on genetic signatures in P. monticola compared with P. strobus. We discuss the importance of our findings for conservation programs and predictions of species' response to climate change. © 2015 Her Majesty the Queen in Right of Canada. Published by the Botanical Society of America.

  17. Contrast Materials

    Science.gov (United States)

    ... a red blood cell— and have a high degree of "echogenicity", or ability to reflect ultrasound waves. ... and radiologist to understand the potential risks and benefits of the contrast-enhanced scan. For MR imaging, ...

  18. 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.

  19. 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,…

  20. The business of demographics.

    Science.gov (United States)

    Russell, C

    1984-06-01

    The emergence of "demographics" in the past 15 years is a vital tool for American business research and planning. Tracing demographic trends became important for businesses when traditional consumer markets splintered with the enormous changes since the 1960s in US population growth, age structure, geographic distribution, income, education, living arrangements, and life-styles. The mass of reliable, small-area demographic data needed for market estimates and projections became available with the electronic census--public release of Census Bureau census and survey data on computer tape, beginning with the 1970 census. Census Bureau tapes as well as printed reports and microfiche are now widely accessible at low cost through summary tape processing centers designated by the bureau and its 12 regional offices and State Data Center Program. Data accessibility, plummeting computer costs, and businessess' unfamiliarity with demographics spawned the private data industry. By 1984, 70 private companies were offering demographic services to business clients--customized information repackaged from public data or drawn from proprietary data bases created from such data. Critics protest the for-profit use of public data by companies able to afford expensive mainframe computer technology. Business people defend their rights to public data as taxpaying ceitzens, but they must ensure that the data are indeed used for the public good. They must also question the quality of demographic data generated by private companies. Business' demographic expertise will improve when business schools offer training in demography, as few now do, though 40 of 88 graduate-level demographic programs now include business-oriented courses. Lower cost, easier access to business demographics is growing as more census data become available on microcomputer diskettes and through on-line linkages with large data bases--from private data companies and the Census Bureau itself. A directory of private and

  1. Chronological objects in demographic research

    Directory of Open Access Journals (Sweden)

    Frans J. Willekens

    2013-03-01

    Full Text Available BACKGROUND Calendar time, age and duration are chronological objects. They represent an instant or a time period. Age and duration are usually expressed in units with varying lengths. The number of days in a month or a year depends on the position on the calendar. The units are also not homogeneous and the structure influences measurement. One solution, common in demography, is to use units that are large enough for the results not to be seriously affected by differences in length and structure. Another approach is to take the idiosyncrasy of calendars into account and to work directly with calendar dates. The technology that enables logical and arithmetic operations on dates is available. OBJECTIVE To illustrate logical and arithmetic operations on dates and conversions between time measurements. METHODS Software packages include utilities to process dates. I use existing and a few new utilities in R to illustrate operations on dates and conversions between calendar dates and elapsed time since a reference moment or a reference event. Three demographic applications are presented. The first is the impact of preferences for dates and days on demographic indicators. The second is event history analysis with time-varying covariates. The third is microsimulation of life histories in continuous time. CONCLUSIONS The technology exists to perform operations directly on dates, enabling more precise calculations of duration and elapsed time in demographic analysis. It eliminates the need for (a approximations and (b transformations of dates, such as Century Month Code, that are convenient for computing durations but are a barrier to interpretation. Operations on dates, such as the computation of age, should consider time units of varying length.

  2. Demographic estimation methods for plants with dormancy

    Science.gov (United States)

    Kery, M.; Gregg, K.B.

    2004-01-01

    Demographic studies in plants appear simple because unlike animals, plants do not run away. Plant individuals can be marked with, e.g., plastic tags, but often the coordinates of an individual may be sufficient to identify it. Vascular plants in temperate latitudes have a pronounced seasonal life–cycle, so most plant demographers survey their study plots once a year often during or shortly after flowering. Life–states are pervasive in plants, hence the results of a demographic study for an individual can be summarized in a familiar encounter history, such as 0VFVVF000. A zero means that an individual was not seen in a year and a letter denotes its state for years when it was seen aboveground. V and F here stand for vegetative and flowering states, respectively. Probabilities of survival and state transitions can then be obtained by mere counting.Problems arise when there is an unobservable dormant state, i.e., when plants may stay belowground for one or more growing seasons. Encounter histories such as 0VF00F000 may then occur where the meaning of zeroes becomes ambiguous. A zero can either mean a dead or a dormant plant. Various ad hoc methods in wide use among plant ecologists have made strong assumptions about when a zero should be equated to a dormant individual. These methods have never been compared among each other. In our talk and in Kéry et al. (submitted), we show that these ad hoc estimators provide spurious estimates of survival and should not be used.In contrast, if detection probabilities for aboveground plants are known or can be estimated, capturerecapture (CR) models can be used to estimate probabilities of survival and state–transitions and the fraction of the population that is dormant. We have used this approach in two studies of terrestrial orchids, Cleistes bifaria (Kéry et al., submitted) and Cypripedium reginae(Kéry & Gregg, submitted) in West Virginia, U.S.A. For Cleistes, our data comprised one population with a total of 620

  3. New Granadan native populations: recent demographic research.

    Science.gov (United States)

    Villamarin, J A

    1982-01-01

    A survey of recent work on the demographic history of the colonial native populations in the area that is now Colombia is presented, with emphasis on the study of the Chibcha Indians. Information is included on published data, sources, issues, and future research questions.

  4. 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...

  5. 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

  6. DEMOGRAPHIC SECURITY: THEORY, METHODOLOGY, EVALUATION

    Directory of Open Access Journals (Sweden)

    Mikhail V. Karmanov

    2015-01-01

    Full Text Available The paper analyzes the theoretical aspects of demographic security. Reviewed and analyzed the point of view of various scholars to the definition of demographic security. The main directions of statistical analysis of demographic security.

  7. HISTOPATHOLOGIC AND DEMOGRAPHIC

    African Journals Online (AJOL)

    Esem

    ABSTRACT. Background: Thyroid gland disease is a common disorder of the endocrine system worldwide.This disease varies according to the environment. The aim of this study is to determine demographic and histopathologic patterns of thyroid disease at the University Teaching Hospital,. Lusaka, Zambia. Methods: This ...

  8. Planning, demographics and Slovenia

    Directory of Open Access Journals (Sweden)

    Aleksander Jakoš

    2009-01-01

    Full Text Available In this article, the issue of demographics is presented as one of the most important factors in regard to the future development of Slovenia. We are still not fully aware of the consequences of the demographic development in the past, which has caused the current situation. The balance between the active and retired population is disturbed, as the percentage of retired persons is on the increase. This process will continue, because the number of retirements will increase in the future, mainly due to the demographic reasons. In regard to the current age the structure of the population in Slovenia, we can expect a huge and absolute increase in the number of elderly people and an even faster increase in the percentage of elderly people in the entire population. The number of retired persons will indirectly increase due to the longer life expectancy. In a demographic sense, the increase of elderly people means a significantly higher annual number of deaths and therefore a strong negative natural growth. This will be even more evident due to the significant decrease of the number of births in the last 30 years. This problem arises not only from low birth rates, but also due to the fact that the generations of women in their fertility period are less numerous.

  9. 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...

  10. 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.

  11. 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...

  12. 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

  13. Immediate hypersensitivity reaction to gadolinium-based MR contrast media.

    Science.gov (United States)

    Jung, Jae-Woo; Kang, Hye-Ryun; Kim, Min-Hye; Lee, Whal; Min, Kyung-Up; Han, Moon-Hee; Cho, Sang-Heon

    2012-08-01

    To determine the incidence and risk factors of immediate hypersensitivity reactions to gadolinium-based magnetic resonance (MR) contrast agents. Institutional review board approval and a waiver of informed consent were obtained. A retrospective study of patients who had been given gadolinium-based MR contrast media between August 2004 and July 2010 was performed by reviewing their electronic medical records. In addition to data on immediate hypersensitivity reaction, the kinds of MR contrast media and demographic data including age, sex, and comorbidity were collected. To compare the groups, the χ(2) test, Fisher exact test, χ(2) test for trend, Student t test, analysis of variance test, and multiple logistic regression test were performed. A total of 112 immediate hypersensitivity reactions (0.079% of 141 623 total doses) were identified in 102 patients (0.121% of 84 367 total patients). Among the six evaluated MR contrast media, gadodiamide had the lowest rate (0.013%) of immediate hypersensitivity reactions, while gadobenate dimeglumine had the highest rate (0.22%). The rate for immediate hypersensitivity reactions was significantly higher in female patients (odds ratio = 1.687; 95% confidence interval: 1.143, 2.491) and in patients with allergies and asthma (odds ratio = 2.829; 95% confidence interval: 1.427, 5.610). Patients with a previous history of immediate hypersensitivity reactions had a higher rate of recurrence after reexposure to MR contrast media (30%) compared with the incidence rate in total patients (P immediate hypersensitivity reactions increased depending on the number of times patients were exposed to MR contrast media (P for trend = .036). The most common symptom was urticaria (91.1%), and anaphylaxis occurred in 11 cases (9.8%). The mortality rate was 0.0007% because of one fatality. The incidence of immediate hypersensitivity reactions to MR contrast media was 0.079%, and the recurrence rate of hypersensitivity reactions was 30% in

  14. 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...

  15. 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.

  16. Geo-Demographic Risks in the Apuseni Mountains. Demographic Ageing

    OpenAIRE

    GABRIELA-ALINA MUREŞAN; CRISTIAN-NICOLAE BOŢAN

    2014-01-01

    The territorial system of the Apuseni Mountains can be considered a critical region from a geo-demographic viewpoint. This is due to two major geo-demographic risks that affect it at present, namely the massive migration, mainly of the young and adult population, and the severe decrease in birth rate, also as a consequence of migration. These two processes determine the main two geo-demographic risks within the Apuseni Mountains: on the one hand, depopulation and the geo-demographic decline o...

  17. 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...

  18. 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...

  19. 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.)

  20. 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

  1. 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.

  2. 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 (U; 13.8%) in the Kurds may testify ... Neolithic after the technologies for food production were. ∗For correspondence. E-mail: ..... MtDNA haplogroup frequencies in the Kurdish groups. Haplogroup. So. Ha. Kur. Kal. Iq_Ku.

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... Jansson, 2000; Hewitt, 2000). Range changes can be expected to have genetic consequences and the advent of DNA technology provides suitable markers to examine the genetic effects of these changes (Hewitt, 2000). In the modern oceans, most of (> 75%) the marginal. *Corresponding author. E-mail: ...

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

    Indian Academy of Sciences (India)

    drift due to small population size; while in the Kurmanji group it indicated a bias towards drift or mass migration events dur- ing the 5–18th century AD. The Mantel test showed strong isolation ...... Izady M. R. 1992 The Kurds: A concise handbook, 1st edition. Taylor and Francis, London, UK. Kloss-Brandstätter A., Pacher D., ...

  5. 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 habit...

  6. The pre-history of demographic regions in traditional Europe.

    Science.gov (United States)

    Poos, L R

    1986-01-01

    The origins of regional variations observed in the household formation systems of rural Europe in the preindustrial era are explored. The author notes that recently exploited census-type data sources concerning Byzantine Greece, early Renaissance Italy, and late medieval England have made it possible to argue that the broad regional variations established at the eve of industrialization are in fact discernible from a much earlier era. The available data on household size and type are also reviewed, with a focus on English data. (SUMMARY IN FRE AND GER)

  7. 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

  8. 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

  9. 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.

  10. 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.

  11. [The demographic doctrines of Plato].

    Science.gov (United States)

    Vilquin, E

    1982-01-01

    Plato has been invoked so often in discussions of population and so many different and contradictory attitudes toward population and demography have been attributed to him that it is necessary to examine his own works and their context in order to understand his true views of the subject. This article briefly examines Plato's demographic thought and its relation to the sociopolitical conditions and intellectual currents of his time and place. The major themes of his demographic work are viewed as outgrowths of the fundamental principles of platonic philosophy and ethics: perfect love, biological and spiritual fertility, procreation as a duty, eugenics, moderation and static equilibrium, the need for demographic legislation, and the justification for and methods of demographic policy. The demographic doctrines espoused in Plato's "Laws" and "The Republic" are then examined. Analysis of Plato's global demographic thought demonstrates how the implementation of perfectly logical means of improving the collective good through measures affecting social organization, legislation, and education resulted in the most totalitarian demographic doctrine ever enunciated. Thus for example, the necessity of harmonizing the ideal of platonic love with the biologic renewal of society led Plato to grant rulers absolute and exclusive power over the family, marriage, sexuality, procreation, and the life and death of infants.

  12. 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.

  13. 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.

  14. 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...

  15. 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...

  16. 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...

  17. Demographic Future of Gorski Kotar

    Directory of Open Access Journals (Sweden)

    Ivan Lajić

    2010-08-01

    Full Text Available Demographic development of Gorski Kotar has largely been a reflection of unfavourable natural-geographic and socio-economic circumstances, which had impelled emigration of the population from this region already by the end of the 19th century, and this process has not stopped till nowadays. The decrease in the total number of inhabitants has been strongly influenced by decades of emigration. Since the 1960s, negative natural movements have significantly contributed to total depopulation. Based on the analysis of negative demographic processes in the Gorski Kotar region, several kinds of demographic projections have been made for the period until 2021. According to these projections, further negative demographic tendencies and additional diminution of the Gorski Kotar population, as well as a negative birth-rate and the erosion of all demographic and economic structures are expected. Population ageing will be a fundamental determinant of future demographic development of the observed area, because every third inhabitant will be more than 60 years old and this points to potential problems in the social and economic development of the region.

  18. 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.

  19. 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.)

  20. Geo-Demographic Risks in the Apuseni Mountains. Demographic Ageing

    Directory of Open Access Journals (Sweden)

    GABRIELA-ALINA MUREŞAN

    2014-12-01

    Full Text Available The territorial system of the Apuseni Mountains can be considered a critical region from a geo-demographic viewpoint. This is due to two major geo-demographic risks that affect it at present, namely the massive migration, mainly of the young and adult population, and the severe decrease in birth rate, also as a consequence of migration. These two processes determine the main two geo-demographic risks within the Apuseni Mountains: on the one hand, depopulation and the geo-demographic decline of the settlements and, on the other hand, population ageing. The present study aims to analyse the latter by focussing on the Land of the Moţi. Conclusions emphasise a rather severe process of demographic ageing. The rate of the old age group increased from 17.9% in 1992 to 25.2% in 2011. All the 16 administrative-territorial units under analysis recorded an increase in the rate of the old age group. In 2011, the ratio of the extreme age groups (young population/old age group is above the unit (1 both in the region as a whole and in the majority of its administrative units.

  1. 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

  2. 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

  3. 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....

  4. 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....

  5. 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...... measures used to reduce the incidence of CIN, and the management of patients receiving metformin. Key Points • Definition, risk factors and prevention of contrast medium induced nephropathy are reviewed. • CIN risk is lower with intravenous than intra-arterial iodinated contrast medium. • eGFR of 45 ml....../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....

  6. 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.

  7. 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.

  8. Contrastes de Forma: Contrastes de ilusiones (I)

    OpenAIRE

    Salvador González, José María

    1986-01-01

    Primera parte del análisis crítico de los principales movimientos artísticos representados en la Exposición Contrastes de Forma, organizada por varios museos de Nueva York en el Museo de Arte Contemporáneo de Caracas.

  9. 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)

  10. Portraying User Interface History

    DEFF Research Database (Denmark)

    Jørgensen, Anker Helms

    2008-01-01

    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...... history at large have been sparse. However, a small spate of publications appeared recently, so a reasonable number of papers are available. Hence this work-in-progress paints a portrait of the current history of user interfaces at large. The paper first describes a theoretical framework recruited from...... 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...

  11. 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

  12. Changing Demographics: Challenges for Educators.

    Science.gov (United States)

    Williams, Betty Fry

    1992-01-01

    This paper identifies demographic changes in the areas of poverty, single-parent families, teenage pregnancy, and educational achievement, with emphasis on increased vulnerability of minority populations. It also notes related challenges to the educational system in personnel recruitment and preparation, effective delivery of educational services…

  13. The demographic situation in Cambodia.

    Science.gov (United States)

    Huguet, J W

    1991-12-01

    The demographic situation in Cambodia is described. Various estimates made by official bodies are used, since very little statistical data exists for the country. Estimates are provided for age and sex distribution, spatial distribution, the disabled population, widowed and separated women, numbers of displaced persons by province, and number of returnees expected from camps in neighboring Thailand.

  14. 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…

  15. 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...

  16. General perceptual contrast metric

    Science.gov (United States)

    Liberg, Anna; Hasler, David

    2003-06-01

    A combined achromatic and chromatic contrast metric for digital images and video is presented in this paper. Our work is aimed at tuning any parametric rendering algorithm in an automated way by computing how much details an observer perceives in a rendered scene. The contrast metric is based on contrast analysis in spatial domain of image sub-bands constructed by pyramidal decomposition of the image. The proposed contrast metric is the sum of the perceptual contrast of every pixel in the image at different detail levels corresponding to different viewing distances. The novel metric shows high correlation with subjective experiments. Important applications involve optimal parameter set of any image rendering and contrast enhancement technique or auto exposure of an image capturing device.

  17. [The demographer's point of view].

    Science.gov (United States)

    Arias De Blois, J

    1993-03-01

    Although the predictable consequence of the acceleration of world population growth were foreseen 40 years ago, the need for population education did not become obvious until much later. Only in the 1960s did a number of countries become aware of changes in population dynamics and their implications for the quality of life and for socioeconomic development goals. Population phenomena and their implications are almost as poorly understood by most persons today as they were when the first population policies were announced. Population education has been viewed as a means of achieving a better understanding of population phenomena. It is believed that acquiring knowledge of population phenomena will promote responsible decision making on questions related to population problems. The early preoccupation in population education with fertility and family planning aroused considerable resistance. There is still strong resistance to including population dynamics and their implications in educational programs. But the most exclusive interest in family planning as a means of reducing the population explosion has broadened in response to a number of events including recognition of family planning as a human right, studies of the effects of high fertility on maternal-child health and education, the mortality decline in developing countries, and the strong increase in migratory movements resulting from urbanization and other causes. The university teaching of demography has become important only recently, and population education at the elementary and secondary level is more recent still. Each educational system must decide for itself the best bode of integrating demographic themes into the different disciplines. The principal demographic themes that should be incorporated will generally fit into existing programs of study. Because of the dynamic nature of demographic phenomena, the content of population education should be reviewed periodically with the assistance of a

  18. 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....

  19. 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.)

  20. Dialysis and contrast media

    Energy Technology Data Exchange (ETDEWEB)

    Morcos, Sameh K. [Department of Diagnostic Imaging, Northern General Hospital, Sheffield Teaching Hospitals NHS Trust, Sheffield S5 7AU (United Kingdom); Thomsen, Henrik S. [Department of Diagnostic Radiology 54E2, Copenhagen University Hospital at Herlev, Herlev Ringvej 75, 2730 Herlev (Denmark); Webb, Judith A.W. [Department of Diagnostic Imaging, St Bartholomew' s Hospital, London EC1A 7BE (United Kingdom)

    2002-12-01

    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.)

  1. Bet Hedging against Demographic Fluctuations

    Science.gov (United States)

    Xue, BingKan; Leibler, Stanislas

    2017-09-01

    Biological organisms have to cope with stochastic variations in both the external environment and the internal population dynamics. Theoretical studies and laboratory experiments suggest that population diversification could be an effective bet-hedging strategy for adaptation to varying environments. Here we show that bet hedging can also be effective against demographic fluctuations that pose a trade-off between growth and survival for populations even in a constant environment. A species can maximize its overall abundance in the long term by diversifying into coexisting subpopulations of both "fast-growing" and "better-surviving" individuals. Our model generalizes statistical physics models of birth-death processes to incorporate dispersal, during which new populations are founded, and can further incorporate variations of local environments. In this way, we unify different bet-hedging strategies against demographic and environmental variations as a general means of adaptation to both types of uncertainties in population growth.

  2. 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

  3. 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).

  4. Describing contrast across scales

    Science.gov (United States)

    Syed, Sohaib Ali; Iqbal, Muhammad Zafar; Riaz, Muhammad Mohsin

    2017-06-01

    Due to its sensitive nature against illumination and noise distributions, contrast is not widely used for image description. On the contrary, the human perception of contrast along different spatial frequency bandwidths provides a powerful discriminator function that can be modeled in a robust manner against local illumination. Based upon this observation, a dense local contrast descriptor is proposed and its potential in different applications of computer vision is discussed. Extensive experiments reveal that this simple yet effective description performs well in comparison with state of the art image descriptors. We also show the importance of this description in multiresolution pansharpening framework.

  5. 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, ...

  6. 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 ...

  7. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

    (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......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...... efficiency. Optimization can address practical issues, such as finding an optimal spatial filter for the chosen application, and can even enable a Reverse Phase Contrast mode where intensity patterns are converted into a phase modulation....

  8. 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...

  9. 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

  10. Demographic consequences of defeating aging.

    Science.gov (United States)

    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 of this study is that population changes are surprisingly slow in their response to a dramatic life extension. For example, we applied the cohort-component method of population projections to 2005 Swedish population for several scenarios of life extension and a fertility schedule observed in 2005. Even for very long 100-year projection horizon, with the most radical life extension scenario (assuming no aging at all after age 60), the total population increases by 22% only (from 9.1 to 11.0 million). Moreover, if some members of society reject to use new anti-aging technologies for some religious or any other reasons (inconvenience, non-compliance, fear of side effects, costs, etc.), then the total population size may even decrease over time. Thus, even in the case of the most radical life extension scenario, population growth could be relatively slow and may not necessarily lead to overpopulation. Therefore, the real concerns should be placed not on the threat of catastrophic population consequences (overpopulation), but rather on such potential obstacles to a success of biomedical war on aging, as scientific, organizational, and financial limitations.

  11. 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...

  12. Mountains too high and valleys too deep drive population structuring and demographics in a Qinghai-Tibetan Plateau frogNanorana pleskei(Dicroglossidae).

    Science.gov (United States)

    Zhou, Weiwei; Jin, Jieqiong; Wu, Jun; Chen, Hongman; Yang, Junxiao; Murphy, Robert W; Che, Jing

    2017-01-01

    Pleistocene glacial-interglacial climatic oscillations greatly shaped the current genetic structure of many species. However, geographic features may influence the impact of climatic cycling. Distinct geographic and environmental characters between northern and southern parts of the eastern Qinghai-Tibetan Plateau (EQTP) facilitate explorations into the impacts of geographic features on species. The northern parts of EQTP contain large areas of marsh, and the environment is rather homogeneous. In contrast, the southern EQTP harbors complex alpine valleys and a much more heterogeneous setting. We evaluate DNA sequence variation from both the mitochondrial and nuclear genomes in Nanorana pleskei , a species endemic to the EQTP. Hypothesis testing on the evolutionary history of N. pleskei indicates that northern populations can disperse freely, but alpine valleys isolate southern populations. Demographic histories between northern and southern populations also differ. Northern populations appear to have experienced population expansions, while southern frogs exhibit a far more stable demographic history. By combining climatic analyses and species' distribution models, our study suggests that geographic and environmental features drive the differences between the northern and southern EQTP.

  13. The complex biogeographic history of a widespread tropical tree species.

    Science.gov (United States)

    Dick, Christopher W; Heuertz, Myriam

    2008-11-01

    Many tropical forest tree species have broad geographic ranges, and fossil records indicate that population disjunctions in some species were established millions of years ago. Here we relate biogeographic history to patterns of population differentiation, mutational and demographic processes in the widespread rainforest tree Symphonia globulifera using ribosomal (ITS) and chloroplast DNA sequences and nuclear microsatellite (nSSR) loci. Fossil records document sweepstakes dispersal origins of Neotropical S. globulifera populations from Africa during the Miocene. Despite historical long-distance gene flow, nSSR differentiation across 13 populations from Costa Rica, Panama, Ecuador (east and west of Andes) and French Guiana was pronounced (F(ST)= 0.14, R(ST)= 0.39, P F(ST)) to the divergences between cis- and trans-Andean populations. Both DNA sequence and nSSR data reflect contrasting demographic histories in lower Mesoamerica and Amazonia. Amazon populations show weak phylogeographic structure and deviation from drift-mutation equilibrium indicating recent population expansion. In Mesoamerica, genetic drift was strong and contributed to marked differentiation among populations. The genetic structure of S. globulifera contains fingerprints of drift-dispersal processes and phylogeographic footprints of geological uplifts and sweepstakes dispersal.

  14. 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.

  15. 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.

  16. Comparative demographics of a Hawaiian forest bird community

    Science.gov (United States)

    Guillaumet, Alban; Woodworth, Bethany L.; Camp, Richard J.; Paxton, Eben H.

    2016-01-01

    Estimates of demographic parameters such as survival and reproductive success are critical for guiding management efforts focused on species of conservation concern. Unfortunately, reliable demographic parameters are difficult to obtain for any species, but especially for rare or endangered species. Here we derived estimates of adult survival and recruitment in a community of Hawaiian forest birds, including eight native species (of which three are endangered) and two introduced species at Hakalau Forest National Wildlife Refuge, Hawaiʻi. Integrated population models (IPM) were used to link mark–recapture data (1994–1999) with long-term population surveys (1987–2008). To our knowledge, this is the first time that IPM have been used to characterize demographic parameters of a whole avian community, and provides important insights into the life history strategies of the community. The demographic data were used to test two hypotheses: 1) arthropod specialists, such as the ‘Akiapōlā‘au Hemignathus munroi, are ‘slower’ species characterized by a greater relative contribution of adult survival to population growth, i.e. lower fecundity and increased adult survival; and 2) a species’ susceptibility to environmental change, as reflected by its conservation status, can be predicted by its life history traits. We found that all species were characterized by a similar population growth rate around one, independently of conservation status, origin (native vs non-native), feeding guild, or life history strategy (as measured by ‘slowness’), which suggested that the community had reached an equilibrium. However, such stable dynamics were achieved differently across feeding guilds, as demonstrated by a significant increase of adult survival and a significant decrease of recruitment along a gradient of increased insectivory, in support of hypothesis 1. Supporting our second hypothesis, we found that slower species were more vulnerable species at the global

  17. 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 with a si......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...

  18. 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)

  19. Our Demographically Divided World, Worldwatch Paper 74.

    Science.gov (United States)

    Brown, Lester R.; Jacobson, Jodi L.

    Existing demographic analyses do not explain the negative relationship between population growth and life-support systems that are now emerging in scores of developing countries. The demographic transition, a theory first outlined by demographer Frank Notestein in 1945, classified all societies into one of three stages. Drawing heavily on the…

  20. 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

  1. 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.

  2. Conceptual History, Cultural History, Social History

    Directory of Open Access Journals (Sweden)

    Viktor Zhivov (†

    2014-10-01

    Full Text Available V. M. Zhivov’s introduction to Studies in Historical Semantics of the Russian Language in the Early Modern Period (2009, translated here for the first time, offers a critical survey of the historiography on Begriffsgeschichte, the German school of conceptual history associated with the work of Reinhart Koselleck, as well as of its application to the study of Russian culture.  By situating Begriffsgeschichte in the context of late-nineteenth and early twentieth-century European philosophy, particularly hermeneutics and phenomenology, the author points out the important, and as yet unacknowledged, role that Russian linguists have played in the development of a native school of conceptual history.  In the process of outlining this alternative history of the discipline, Zhivov provides some specific examples of the way in which the study of “historical semantics” can be used to analyze the development of Russian modernity.

  3. 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)

  4. 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...

  5. 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.

  6. 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...

  7. 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.)

  8. Polychromatic diffraction contrast tomography

    International Nuclear Information System (INIS)

    King, A.; Reischig, P.; Adrien, J.; Peetermans, S.; Ludwig, W.

    2014-01-01

    This tutorial review introduces the use of polychromatic radiation for 3D grain mapping using X-ray diffraction contrast tomography. The objective is to produce a 3D map of the grain shapes and orientations within a bulk, millimeter-sized polycrystalline sample. The use of polychromatic radiation enables the standard synchrotron X-ray technique to be applied in a wider range of contexts: 1) Using laboratory X-ray sources allows a much wider application of the diffraction contrast tomography technique. 2) Neutron sources allow large samples, or samples containing high Z elements to be studied. 3) Applied to synchrotron sources, smaller samples may be treated, or faster measurements may be possible. Challenges and particularities in the data acquisition and processing, and the limitations of the different variants, are discussed. - Highlights: • We present a tutorial review of polychromatic diffraction contrast tomography techniques. • The use of polychromatic radiation allows the standard synchrotron DCT technique to be extended to a range of other sources. • The characteristics and limitations of all variants of the techniques are derived, discussed and compared. • Examples using laboratory X-ray and cold neutron radiation are presented. • Suggestions for the future development of these techniques are presented

  9. 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

  10. 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.

  11. 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

  12. Demographic responses of boreal-montane orchid Malaxis monophyllos (L. Sw. populations to contrasting environmental conditions

    Directory of Open Access Journals (Sweden)

    Edyta Jermakowicz

    2016-03-01

    Full Text Available In an age of changes in species’ geographical ranges, compounded by climatic and anthropogenic impacts, it become important to know which processes and factors influence plant populations and their persistence in the long term. Here we investigated dynamic and fitness components in twelve populations of Malaxis monophyllos (L. Sw., situated in different geographical (regions and ecological (type of habitat units. Although M. monophyllos is a rare species, characterized by highly fragmented, boreal-montane distribution range, in last few decades it successfully colonized secondary habitats in Polish uplands. Our results indicate that M. monophyllos is represented mainly by small populations, which annual spatial and temporal changes might be very high, what affects the ephemeral character of these populations, regardless of the region and type of habitat. This dynamic structure, in turn, is caused by intensive exchange of individuals in populations, as well as by their short above-ground life span. Despite the large range of variation in size and reproductive traits, we can distinguish some regional patterns, which indicate boreal region as the most optimal for M. monophyllos growth and persistence in the long term, and with montane and upland/anthropogenic populations, due to lower reproductive parameters, as the most threatened. Although it should be considered that anthropogenic populations, despite their lower reproductive parameters and instability in the long term, present an intermediate, geographical and ecological character, therefore they may be valuable in shaping, both M. monophyllos’ future range, as well as its potential for response on ongoing and future changes. In general, reproduction is the main factor differentiating of M. monophyllos populations in regions, and we can suspect that it may become the cause of the future differentiation and isolation of these populations, occurring with progressive range fragmentation.

  13. Familial cluster headache: demographic patterns in affected and nonaffected.

    Science.gov (United States)

    Sjöstrand, Christina; Russell, Michael Bjørn; Ekbom, Karl; Waldenlind, Elisabet

    2010-03-01

    Smoking has been claimed to be more common in cluster headache (CH) sufferers than in nonaffected subjects. Other demographic information such as handedness, body mass index, eye color, education, occupation, and alcohol use has been described as being different in CH patients compared with a control population. The aim of this study was to get more detailed information in CH patients with a positive family history and their nonaffected relatives, assuming that there would be demographic differences between the groups. Affected CH patients and nonaffected first- and second-degree relatives (n = 114) received a posted questionnaire. Information from 83 subjects (42 affected and 41 first- and/or second-degree relatives) from 23 families was received. P personality-lifestyle-related phenomena or a combination of these mechanisms.

  14. Climate Change, Demographics, Technology, and Globalization: Their Impact on the Acquisition Community

    Science.gov (United States)

    2008-04-01

    changes in climate, demographics, technology , and globalization . History is replete with examples of unexpected events that startled and surprised...sensitive, and advanced technology will become more difficult to keep secure and shared only as intended by the United States. Globalization Local...located in low-lying coastal and other water-stressed areas will pose greater T R A N S F O R M A T I O N Climate Change, Demographics, Technology

  15. 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 ...

  16. 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.

  17. 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.

  18. 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.

  19. The welfare state and demographic dividends

    Directory of Open Access Journals (Sweden)

    Gemma Abío

    2017-05-01

    Full Text Available Background: The demographic transition experienced by developed countries produces initial positive effects on economic growth ‒ the first demographic dividend ‒ which can be extended into a second demographic dividend if baby boomers' savings increase capital accumulation. Nevertheless, aging might reverse this process if dissaving of elderly baby boomers and the pressure on the pay-as-you-go financed welfare state reduce savings and capital. Objective: The aim of this paper is to evaluate the extent to which demographic dividends in Spain provide an opportunity for the reform of the welfare state system for an aging population. Methods: We decompose demographic dividends using a general equilibrium overlapping generations model with realistic demography and public transfers from the National Transfer Accounts database. This allows us to capture the endogenous evolution of savings and capital accumulation and, hence, the second demographic dividend. Results: When baby boomers enter the labor market, the purely demographic support ratio increases and this positive effect is extended by composition changes in the age structure of workers. When they start saving, the second demographic dividend arises, while its total net effect depends both on the strength of the aging process and on transfer size. Conclusions: The derived decomposition shows that the second demographic dividend might also disappear. Sharp population aging in Spain implies that capital will shrink drastically after 2040. Before this, there seems to be margin for reforms; however, an extension of the welfare state toward the Nordic model would considerably reduce capital. Contribution: This paper contributes to the debate on the effects of demographics on economic growth by decomposing demographic dividends and investigating the impact of different welfare state transfer systems on the second demographic dividend.

  20. The Epidemiology and Demographics of Hip Dysplasia

    Science.gov (United States)

    Loder, Randall T.; Skopelja, Elaine N.

    2011-01-01

    The etiology of developmental dysplasia of the hip (DDH) is unknown. There are many insights, however, from epidemiologic/demographic information. A systematic medical literature review regarding DDH was performed. There is a predominance of left-sided (64.0%) and unilateral disease (63.4%). The incidence per 1000 live births ranges from 0.06 in Africans in Africa to 76.1 in Native Americans. There is significant variability in incidence within each racial group by geographic location. The incidence of clinical neonatal hip instability at birth ranges from 0.4 in Africans to 61.7 in Polish Caucasians. Predictors of DDH are breech presentation, positive family history, and gender (female). Children born premature, with low birth weights, or to multifetal pregnancies are somewhat protected from DDH. Certain HLA A, B, and D types demonstrate an increase in DDH. Chromosome 17q21 is strongly associated with DDH. Ligamentous laxity and abnormalities in collagen metabolism, estrogen metabolism, and pregnancy-associated pelvic instability are well-described associations with DDH. Many studies demonstrate an increase of DDH in the winter, both in the northern and southern hemispheres. Swaddling is strongly associated with DDH. Amniocentesis, premature labor, and massive radiation exposure may increase the risk of DDH. Associated conditions are congenital muscular torticollis and congenital foot deformities. The opposite hip is frequently abnormal when using rigorous radiographic assessments. The role of acetabular dysplasia and adult hip osteoarthritis is complex. Archeological studies demonstrate that the epidemiology of DDH may be changing. PMID:24977057

  1. 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.

  2. 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...

  3. 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...... is proposed as a coordinate system that fully describes temporal variation in demographic data....

  4. Contrast-induced nephropathy

    Energy Technology Data Exchange (ETDEWEB)

    Persson, P.B. [Inst. of Physiology, Humboldt Univ., Medizinische Fakultaet (Charite), Berlin (Germany)

    2005-11-15

    How contrast medium-induced nephropathy (CIN) comes about is not fully understood, although CIN constitutes a leading cause of renal failure. Here, a short review of clinical trials and a more thorough outline of mechanisms thought to cause CIN are outlined. Osmolality is only one of several physicochemical properties of contrast media (CM). Iso-osmolar CM are dimers, not monomers. Thus, they have physicochemical features different from other CM, e. g., in terms of viscosity (which is over fivefold greater than plasma viscosity). This may be of considerable pathophysiologic and clinical importance. There are studies providing evidence for a greater perturbation in renal functions by iso-osmolar CM in comparison to nonionic low-osmolar CM. Conversely, some previous clinical trials indicate an advantage of the iso-osmolar CM. This review highlights altered rheological properties, perturbation of renal hemodynamics, regional hypoxia, auto- and paracrine factors (adenosine, endothelin, reactive oxygen species) and direct cytotoxic effects, which are all thought to participate in causing CIN. It is concluded that the use of CM in general, and high viscous iso-osmolar CM in particular, can be deleterious to the kidney due to augmented resistance in the renal tubules. (orig.)

  5. 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.......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 program...... called isotonic regression. We provide a few analytic properties of the solutions to this problem. We also design a tailored first order optimization procedure together with a full complexity analysis. The proposed method turns out to be practically more efficient and reliable than the best existing...

  6. Demographic manipulation in the Caucasus (with special reference to Georgia).

    Science.gov (United States)

    Hewitt, B G

    1995-01-01

    The author discusses political developments in the Caucasus region since the collapse of the Soviet Union. The focus is on the events in Georgia that led to the war in South Ossetia (particularly in Abkhazia), and the author suggests that this development is the latest in a 200-year history of demographic manipulation of minority peoples by the region's two major powers, Russia and Georgia. Parallels are drawn between the Georgian war in Abkhazia and Russia's war in Chechenia. The author questions the value of the principle of territorial integrity, and suggests that alternative principles safeguarding the rights of ethnic minorities would be more appropriate in these circumstances.

  7. 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.)

  8. 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

  9. 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 Geor...... for solutions and policies, is the agenda for an engaged environmental history from now on.......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...

  10. Introducing Labor History.

    Science.gov (United States)

    Whitmer, John Dale

    1997-01-01

    Provides a brief overview for including labor history in the social studies curriculum. Notes the broad range of subjects (geography, history, economics, music, and art) and approaches (women's history, social history, oral history) that encompass labor history. (MJP)

  11. Matematikkens historie

    DEFF Research Database (Denmark)

    Hansen, Vagn Lundsgaard

    2009-01-01

    Matematikkens historie i syv kapitler: 1. Matematik i støbeskeen; 2. Matematikkens græske arv; 3. Den gyldne tidsalder for hinduer og arabere; 4. Matematik i Kina; 5. Renæssancens matematik; 6. Regning med infinitesimaler ser dagens lys; 7. Matematik i det tyvende århundrede.......Matematikkens historie i syv kapitler: 1. Matematik i støbeskeen; 2. Matematikkens græske arv; 3. Den gyldne tidsalder for hinduer og arabere; 4. Matematik i Kina; 5. Renæssancens matematik; 6. Regning med infinitesimaler ser dagens lys; 7. Matematik i det tyvende århundrede....

  12. The State Economic, Demographic & Fiscal Handbook 1993.

    Science.gov (United States)

    Baer, David; Cohen, Lee

    This handbook is an easy-to-use reference book for policymakers, public officials, and policy analysts, as well as anyone else who may need up-to-date information about state economic, demographic, and fiscal data. The book includes data on demographics, poverty rates, per capita state personal income, state and local tax rates, and state and…

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

    African Journals Online (AJOL)

    Background: Meningiomas are common brain tumours and display gender, racial and ethnic differences in their demographic profile. The demographic profile of our patients diagnosed with intracranial meningiomas is presented and compared with the literature. Objectives: To determine the age, gender, racial and ethnic ...

  14. Bias and ignorance in demographic perception.

    Science.gov (United States)

    Landy, D; Guay, B; Marghetis, T

    2017-08-31

    When it comes to knowledge of demographic facts, misinformation appears to be the norm. Americans massively overestimate the proportions of their fellow citizens who are immigrants, Muslim, LGBTQ, and Latino, but underestimate those who are White or Christian. Previous explanations of these estimation errors have invoked topic-specific mechanisms such as xenophobia or media bias. We reconsidered this pattern of errors in the light of more than 30 years of research on the psychological processes involved in proportion estimation and decision-making under uncertainty. In two publicly available datasets featuring demographic estimates from 14 countries, we found that proportion estimates of national demographics correspond closely to what is found in laboratory studies of quantitative estimates more generally. Biases in demographic estimation, therefore, are part of a very general pattern of human psychology-independent of the particular topic or demographic under consideration-that explains most of the error in estimates of the size of politically salient populations. By situating demographic estimates within a broader understanding of general quantity estimation, these results demand reevaluation of both topic-specific misinformation about demographic facts and topic-specific explanations of demographic ignorance, such as media bias and xenophobia.

  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. 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...

  17. 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

  18. 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...

  19. 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...

  20. 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...

  1. The Farm in American History.

    Science.gov (United States)

    Shideler, James H.

    1991-01-01

    Explores the family farm as an economic institution and cultural symbol in U.S. history. Explains how farms worked as economic units. Contrasts the idyllic family farm against realities of business failures and family problems. Examines the family farm's role in shaping the U.S. character and asks what its essential demise will mean. (CH)

  2. Demographic characteristics of users of worksite health promotion written materials.

    Science.gov (United States)

    Golaszewski, T; Yen, L T

    1992-01-01

    Despite a long history of work organizations supplying health-oriented written materials to employees, little was known about the underlying factors contributing to their use. Earlier findings suggested that demographics might play a role in this process. Therefore, this research attempted to define user profiles of four basic written materials commonly found in worksite programs: medical self-care guide, newsletter, health risk appraisal (HRA), and HRA individual report. The results of a post-program questionnaire were collected from 10 work organizations using a commercial health promotion program (N = 5,167; 29.8%). After defining a user for each piece, chi-square and logistic regression determined proportional differences between users and nonusers by selected demographics. After controlling for variable interactions, the most likely user of the medical self-care guide was a non-white, lower educated female over age 40; the newsletter, a female over age 40; the HRA, a higher job rated female; and the HRA report, a female over age 40. Written materials may have a different use pattern than other program offerings, or different than what might have been suspected intuitively. Other than female gender, most demographic variables either offered insignificant or unexpected contributions to prediction models. These results suggest that written materials may have a wider appeal than previously recognized.

  3. 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.

  4. Germ banks affect the inference of past demographic events.

    Science.gov (United States)

    Živković, Daniel; Tellier, Aurélien

    2012-11-01

    Continuous progress in empirical population genetics based on the whole-genome polymorphism data requires the theoretical analysis of refined models in order to interpret the evolutionary history of populations with adequate accuracy. Recent studies focus prevalently on the aspects of demography and adaptation, whereas age structure (for example, in plants via the maintenance of seed banks) has attracted less attention. Germ banking, that is, seed or egg dormancy, is a prevalent and important life-history trait in plants and invertebrates, which buffers against environmental variability and modulates species extinction in fragmented habitats. Within this study, we investigate the combined effect of germ banking and time-varying population size on the neutral coalescent and particularly derive the allele frequency spectrum under some simplifying assumptions. We then perform an ABC analysis using two simple demographic scenarios-a population expansion and an instantaneous decline. We demonstrate the appreciable influence of seed banks on the estimation of demographic parameters depending on the germination rate with biases scaled by the square of the germination rate. In the more complex case of a population bottleneck, which comprises an instantaneous decline and an expansion phase, ignoring information on the germination rate denies reliable estimates of the bottleneck parameters via the allelic spectrum. In particular, when seeds remain in the bank over several generations, recent expansions may remain invisible in the frequency spectrum, whereas ancient declines leave signatures much longer than in the absence of seed bank. © 2012 Blackwell Publishing Ltd.

  5. 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

  6. The demographic effects of technological change and capitalist transformation--a re-interpretation of the demographic transition theory.

    Science.gov (United States)

    Maitra, P

    1992-06-01

    The interrelationship between demographic transition, capitalist transformation, and technological change in the 2 contrasting cases of the UK and India is explored. In the UK, technological change evolved from the extensive to the intensive phase, while technological change was introduced in India from the UK and other developed economies. The Demographic Transition Model is re-examined for these cases while the extensive and intensive phases of technological change with their effects on labor demand and consequent effects on fertility rate are analyzed. Changes in economic structure, demography, and factor pricing systems are presented as indicators of capitalist transformation of an economy. At the onset of capitalist transformation, population growth tends to decline as a result of increasing demand for labor in productive activities. Accordingly, the pattern of population growth depends upon the growth of demand for labor in productive activities which in turn depends upon the nature of the source of technological change; Demographic Transition theory ignores this point. Debate remains over whether imported technology, once reaching maturity, may effect capitalist transformation of economies toward true integrated development.

  7. 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...

  8. Demographic and clinical features of neuromyelitis optica

    DEFF Research Database (Denmark)

    Pandit, L.; Asgari, Nasrin; Apiwattanakul, M.

    2015-01-01

    The comparative clinical and demographic features of neuromyelitis optica (NMO) are not well known. In this review we analyzed peer-reviewed publications for incidence and prevalence, clinical phenotypes, and demographic features of NMO. Population-based studies from Europe, South East and Southern...... course, particularly in anti-aquaporin 4 antibody (anti AQP4-IgG)-positive patients. Ethnicity may have a bearing on disease phenotype and clinical outcome. Despite limitations inherent to the review process, themes noted in clinical and demographic features of NMO among different populations promote...

  9. 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

  10. Demographic spatial genetic structure of the Neotropical tree, Jacaranda copaia.

    Science.gov (United States)

    Jones, F A; Hubbell, S P

    2006-10-01

    We used genotypes from six microsatellite loci and demographic data from a large mapped forest plot to study changes in spatial genetic structure across demographic stages, from seed rain to seedlings, juveniles, and adult diameter classes in the Neotropical tree, Jacaranda copaia. In pairwise comparisons of genetic differentiation among demographic classes, only seedlings were significantly differentiated from the other diameter classes; F(ST) values ranged from 0.006 to 0.009. Furthermore, only seedlings showed homozygote excess suggesting biparental inbreeding in the large diameter reproductive adults. We found very low levels of relatedness in the first distance class of trees, 1-26 cm diameter (F(ij) = 0.011). However, there was a 5- to 10-fold rise in relatedness in the smallest distance class, from the smallest to the largest tree diameter classes (F(ij) = 0.110 for individuals > 56 cm diameter). A variety of non-mutually exclusive mechanisms have been invoked perviously to explain such a pattern, including natural selection, history, or nonequilibrium population dynamics. The long-term demographic data available for this species allow us to evaluate these mechanisms. Jacaranda is a fast-growing, light-demanding species with low recruitment rates and high mortality rates in the smaller diameter classes. It successfully regenerates only in large light gaps, which occur infrequently and stochastically in space and time. These factors contribute to the nonequilibrium population dynamics and observed low genetic structure in the small size classes. We conclude that the pattern of spatial genetic transitions in Jacaranda is consistent with overlapping related generations and strong but infrequent periods of high recruitment, followed by long periods of population decline.

  11. Double contrast gastrography in dogs.

    Science.gov (United States)

    Kumar, R; Peshin, P K; Nigam, J M

    1981-09-01

    For experimental evaluation of double contrast gastrography in 9 dogs, sodium iothalamate and air were used for positive and negative contrast, respectively, to delineate the gastric mucosa. The technic was simple and reasonably safe. Results were satisfactory when the stomach was empty, and appropriate volumes of contrast materials were evenly distributed.

  12. Sommerferiens historie

    DEFF Research Database (Denmark)

    Lützen, Karin

    2011-01-01

    Summer holiday is a pleasure which did not become available to many people until the 20th Century. The article describes the early mountain rambles of the bourgeoisie and their holidays in seaside boarding houses. Outdoor pursuits and stays in boarding houses at bathing resorts also became...... pattern. Finally, the history of the special holiday camps is told, which were established by American Jews because they were excluded from many hotels....

  13. 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

  14. 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

  15. Relationship between some selected Socio Demographic Profiles ...

    African Journals Online (AJOL)

    Abstract. This study assesses the relationship between some selected demographic profiles and methicillin resistant. Staphylococcus aureus (MRSA) amongst 384 apparently healthy residents in Ekpoma, Edo, Nigeria. Following standard protocol, nasal swab samples were subjected to bacteriological investigation and ...

  16. 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...

  17. Professionals and Power Vacuums on Demographic Change

    DEFF Research Database (Denmark)

    Seabrooke, Leonard; Tsingou, Eleni

    . Demographic change is acknowledged as a policy concern within many advanced industrialize countries, but discussions about low fertility are not explicitly expressed in terms of policy objectives. Governments, sensitive to the authoritarian implications of prescriptive natalist policies, focus instead...

  18. Family Formation Trajectories in Romania, the Russian Federation and France : Towards the Second Demographic Transition?

    NARCIS (Netherlands)

    Potarca, Gina; Mills, Melinda; Lesnard, Laurent

    This study examines family formation trajectories as a manifestation of the second demographic transition (SDT) in three countries, comparing and contrasting two post-socialist countries (Romania and the Russian Federation) with France as benchmark country advanced in the SDT. By examining combined

  19. 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

  20. DEMOGRAPHIC CHARACTERISTICS OF STARA ZAGORA MUNICIPALITY

    Directory of Open Access Journals (Sweden)

    Dimitrina Skachkova

    2016-12-01

    Full Text Available The article presents the demographic characteristics of the municipality of Stara Zagora, analyzing and comparing to those of the country the following: population number and dynamics, spatial distribution, sex and age structure, ethnic and confessional structure, educational structure, population movement and others. Attention is also paid to labor resources and unemployment. The conclusions underline the main demographic trends – common for the country and specific for the municipality analyzed.

  1. Stock vs. Bond Yields, and Demographic Fluctuations

    DEFF Research Database (Denmark)

    Gozluklu, Arie; Morin, Annaïg

    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...... a cross-country panel, we document the cross-sectional variation of the demographic effect and explain the cross-country differences in comovement between stock and bond markets....

  2. 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.

  3. Two centuries of demographic change in Canada

    Directory of Open Access Journals (Sweden)

    Barry Edmonston

    2014-03-01

    Full Text Available One key aspect of the demographic transition—the shift from high mortality and high fertility to low mortality and low fertility is a major change in the population’s age distribution from a pyramid-shaped young age structure to a pillar-shaped old age structure. This paper discusses two demographic processes affected by changes in age structure. First, there are effects on vital rates, with important differences in the observed crude rates and the implied intrinsic vital rates. Second, changes in age structure influence population momentum. More recently, demographers have noted that older age distributions associated with fertility levels below replacement have negative population momentum. Although the demographic transition has been well-described for many countries, demographers have seldom analyzed intrinsic vital rates and population momentum over time, which are dynamic processes affected by changes in the population age structure and which, in turn, influence future changes in population growth and size. This paper uses new data and methods to analyze intrinsic vital rates and population momentum across two centuries of demographic change in Canada

  4. 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)

  5. 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.)

  6. Nuclear magnetic resonance contrast agents

    Science.gov (United States)

    Smith, P.H.; Brainard, J.R.; Jarvinen, G.D.; Ryan, R.R.

    1997-12-30

    A family of contrast agents for use in magnetic resonance imaging and a method of enhancing the contrast of magnetic resonance images of an object by incorporating a contrast agent of this invention into the object prior to forming the images or during formation of the images. A contrast agent of this invention is a paramagnetic lanthanide hexaazamacrocyclic molecule, where a basic example has the formula LnC{sub 16}H{sub 14}N{sub 6}. Important applications of the invention are in medical diagnosis, treatment, and research, where images of portions of a human body are formed by means of magnetic resonance techniques. 10 figs.

  7. 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...

  8. LCA History

    DEFF Research Database (Denmark)

    Bjørn, Anders; Owsianiak, Mikołaj; Molin, Christine

    2017-01-01

    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...... internally and made little communication to stakeholders. After a silent period in the 1970s, the 1980s and 1990s saw an increase in methodological development and international collaboration and coordination in the scientific community and method development increasingly took place in universities....... With the consolidation of the methodological basis, application of LCA widened to encompass a rapidly increasing range of products and systems with studies commissioned or performed by both industry and governments, and results were increasingly communicated through academic papers and industry and government reports...

  9. 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...

  10. 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)

  11. 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.

  12. GENDER DEMOGRAPHIC DISPARITIES IN BACAU COUNTY

    Directory of Open Access Journals (Sweden)

    Oana Ancuta Stangaciu

    2014-12-01

    Full Text Available Gender demographic disparities existing in Bacau County were determined by means of some demographic indicators such as: population, natural growth, live births, marriages, divorces, indicators which have been broken down by gender. The assessment of the disparities between men and women from the point of view of the demographic phenomena emphasize the fact that on the level of Bacau County there is a surplus of female population, as during the whole period subjected to the analysis, the positive and respectively the negative natural growth for the male population were lower and higher respectively than the one registered in the case of the female population. The birth rate, marriage rate and divorce rate phenomena also changed significantly after 1990 ; thus, the average age of marriage increased, and the gender difference also had a certain growth, which caused a shift in the fertility intensity from the age group 20-24 to the very next one - the 25-29 age group.

  13. 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.

  14. Demographic and Related Determinants of Recent Cuban Emigration.

    Science.gov (United States)

    Briquets, Sergio Diaz

    1983-01-01

    Examines principal demographic determinants of recent Cuban emigration and discusses how these demographic variables interact with other social, economic, and political determinants. Suggests that Cuban labor migration is more responsive to demographic factors than some theorists assume. (Author/MJL)

  15. [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)

  16. 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

  17. 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

  18. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    -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......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...... 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...

  19. "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.

  20. 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.

  1. 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...

  2. 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.

  3. 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.

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

    African Journals Online (AJOL)

    To determine the influence of the demographic attributes of wholesales yam marketers on their marketing cost, data were collected from 80 respondents randomly selected from 10 yam markets in two Local Government Areas of Delta State. Results of data analysis reveals that wholesale yam marketing in the study area ...

  5. Demographics of Preschoolers Who Require AAC

    Science.gov (United States)

    Binger, Cathy; Light, Janice

    2006-01-01

    PURPOSE: The purpose of the investigation was to gather demographic information pertaining to preschoolers who require augmentative and alternative communication (AAC). METHOD: To obtain this information, a survey was developed and then distributed to preschool speech-language pathologists (SLPs) in Pennsylvania. RESULTS: Results indicated that…

  6. Demographic and Lifestyle Variables Associated with Obesity

    Science.gov (United States)

    Worthy, Sheri L.; Lokken, Kristine; Pilcher, Kenneth; Boeka, Abbe

    2010-01-01

    Objective: Overweight and obesity rates are associated with chronic diseases and higher rates of disability and continue to rise in the United States and worldwide. The purpose of this study was to build on past research and further investigate demographic and lifestyle variables associated with increased body mass index (BMI: kg/m[squared]).…

  7. 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…

  8. Demographic and management factors associated with biosecurity ...

    African Journals Online (AJOL)

    Biosecurity measures are poorly or infrequently implemented in livestock farms. This study attempted to explore reasons for under-implementation of biosecurity in pig farms by determining demographic and management factors related to having good biosecurity score on 144 pig farms in south west Nigeria. A pretested ...

  9. Demographic, ergonomic and psychosocial factors affecting work ...

    African Journals Online (AJOL)

    Work related musculoskeletal disorders have been associated with demographic factors, work stresses and psycho-social stress symptoms. The study aimed to evaluate factors associated with MSDs in different body regions among Indian tobacco processing workers. A group of 450 tobacco processing workers participated ...

  10. Understanding China's Demographic Dividends and Labor Issue

    Science.gov (United States)

    Peng, Xizhe

    2013-01-01

    One of the major concerns about the one-child policy is its negative impact on the current and future labor force in China. People have talked about the Lewis Turning Point and the end of demographic dividends. Some of these arguments, however, can be misleading. The working-age population (ages 15 to 59) can be treated as the potential labor…

  11. Demographic Variables predicting Employees Willingness to share ...

    African Journals Online (AJOL)

    Review of literature on tacit knowledge sharing revealed a dearth of empirical research on the connection between demographic variables and willingness to share tacit knowledge. This study therefore extend tacit knowledge sharing literature by exploring the influence of age, gender, job tenure, and educational level on ...

  12. Demographic and epidemiological characteristics of HIV ...

    African Journals Online (AJOL)

    Background: In view of the maturing HIV epidemic in sub-Saharan Africa, better understanding of its epidemiology among older adults is necessary in order to design appropriate care and treatment programmes for them. Objectives: To describe the demographic and epidemiological characteristics of HIV opportunistic ...

  13. 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

  14. International trade with pensions and demographic shock

    NARCIS (Netherlands)

    Fedotenkov, I.; van Groezen, Bas; Meijdam, Lex

    The central question of this paper is how international trade and specialization are affected by different designs of pension schemes and asymmetric demographic changes. In a model with two goods, two countries and two production factors, we find that countries with a relatively large unfunded

  15. Perceived Organizational Support and Some Demographic ...

    African Journals Online (AJOL)

    The present study investigated the relationship between perceived organizational support and some demographic variables on organizational commitment of non-teaching employees in a state-owned university in Nigeria. Using an ex post facto design, two hundred and six (n=206) non-teaching employees consisting of ...

  16. Demographic and Socioeconomic Factors Influencing Malaria

    African Journals Online (AJOL)

    Gyuk et al.

    examine the demographic and socioeconomic factors of malaria incidence in Calabar, Cross ... environmental hygiene in order to reduce the incidence of malaria in the area. Keywords: Malaria, Incidence, Prevalence and Socioeconomic factors .... were young people who are conscious of their health and are more likely to ...

  17. Prevalence, demographic and psychosocial correlates for school ...

    African Journals Online (AJOL)

    In multivariable logistic regression analysis, socio-demographic factors (older age, being male, the experience of hunger), externalising behaviour (tobacco use, alcohol use, having been in a physical fight, being bullied, having sustained an injury), and lack of protective social-familial factors (lack of peer support and lack of ...

  18. 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 ...

  19. Demographic change, international trade and capital flows

    NARCIS (Netherlands)

    Fedotenkov, I.; van Groezen, B.J.A.M.; Meijdam, A.C.

    2014-01-01

    Trade in goods that are not perfect substitutes can considerably change the predictions of standard neoclassical models about the effects of demographic developments. This paper considers a relative decrease in the population size of one country, when countries specialize in the production of

  20. 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...

  1. 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...

  2. 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 ...

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

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

    23 juin 2009 ... 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 ...

  4. 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.)

  5. 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 ...

  6. Demographic compensation does not rescue populations at a trailing range edge.

    Science.gov (United States)

    Sheth, Seema Nayan; Angert, Amy Lauren

    2018-03-06

    Species' geographic ranges and climatic niches are likely to be increasingly mismatched due to rapid climate change. If a species' range and niche are out of equilibrium, then population performance should decrease from high-latitude "leading" range edges, where populations are expanding into recently ameliorated habitats, to low-latitude "trailing" range edges, where populations are contracting from newly unsuitable areas. Demographic compensation is a phenomenon whereby declines in some vital rates are offset by increases in others across time or space. In theory, demographic compensation could increase the range of environments over which populations can succeed and forestall range contraction at trailing edges. An outstanding question is whether range limits and range contractions reflect inadequate demographic compensation across environmental gradients, causing population declines at range edges. We collected demographic data from 32 populations of the scarlet monkeyflower ( Erythranthe cardinalis ) spanning 11° of latitude in western North America and used integral projection models to evaluate population dynamics and assess demographic compensation across the species' range. During the 5-y study period, which included multiple years of severe drought and warming, population growth rates decreased from north to south, consistent with leading-trailing dynamics. Southern populations at the trailing range edge declined due to reduced survival, growth, and recruitment, despite compensatory increases in reproduction and faster life-history characteristics. These results suggest that demographic compensation may only delay population collapse without the return of more favorable conditions or the contribution of other buffering mechanisms such as evolutionary rescue.

  7. 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.

  8. The second demographic transition and the development level of Colombia departments, 2005

    Directory of Open Access Journals (Sweden)

    Isabel C. Grajales A

    2010-11-01

    Full Text Available Objective: to analyze the behavior of some demographic characteristics for each department to identify the state of demographic transition and its relationship to the development level. Methodology: descriptive study based on secondary information sources published by the National Statistics Department and the National Planning Department. Results: the global fertility rate of the country was 2.5 in 2005. Chocó reported the highest rate whereas Bogotá reported the lowest. A total of 67% of Colombian states registered higher rates than the average rate in the country. Mortality rate of children in the country was 24.5, with the lowest rates registered in El Valle, Caldas, and Bogotá. The highest rates were registered in Arauca and Chocó. 26.6% of Colombian states show some advance in the demographic transition process. By contrast, 67% of the states are classified as lagged behind. There is a relation between the demographic transition index and the development indicators. Conclusion: Although some departments reach an advanced level of demographic transition, most of them still show high rates of infant mortality or fecundity which keep them behind in this process. Inequalities in living conditions of the country’s departments could be influencing the behavior of the demographic components analyzed.

  9. The Generalised Phase Contrast Method

    DEFF Research Database (Denmark)

    Glückstad, Jesper

    An analytic framework and a complete description for the design and optimisation of on-axis centred spatially filtering common path systems are presented. The Generalised Phase Contrast method is derived and introduced as the common denominator for these systems basically extending Zernike......’s original phase contrast scheme into a much wider range of operation and application. It is demonstrated that the Generalised Phase Contrast method can be successfully applied to the interpretation and subsequent optimisation of a number of different, commonly applied spatially filtering architectures...... designs and parameter settings. Finally, a number of original applications facilitated by the parallel light-beam encoding of the Generalised Phase Contrast method are briefly outlined. These include among others, wavefront sensing and generation, advanced usercontrolled optical micro...

  10. Voluntary attention enhances contrast appearance.

    Science.gov (United States)

    Liu, Taosheng; Abrams, Jared; Carrasco, Marisa

    2009-03-01

    Voluntary (endogenous, sustained) covert spatial attention selects relevant sensory information for prioritized processing. The behavioral and neural consequences of such selection have been extensively documented, but its phenomenology has received little empirical investigation. We asked whether voluntary attention affects the subjective appearance of contrast--a fundamental dimension of visual perception. We used a demanding rapid serial visual presentation (RSVP) task to direct endogenous attention to a given location and measured perceived contrast at the attended and unattended locations. Attention increased perceived contrast of suprathreshold stimuli and also improved performance on a concurrent orientation discrimination task at the cued location. We ruled out response bias as an alternative account of the pattern of results. Thus, this study establishes that voluntary attention enhances perceived contrast. This phenomenological consequence links behavioral and neurophysiological studies on the effects of attention.

  11. 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...

  12. Multiscale based adaptive contrast enhancement

    Science.gov (United States)

    Abir, Muhammad; Islam, Fahima; Wachs, Daniel; Lee, Hyoung

    2013-02-01

    A contrast enhancement algorithm is developed for enhancing the contrast of x-ray images. The algorithm is based on Laplacian pyramid image processing technique. The image is decomposed into three frequency sub-bands- low, medium, and high. Each sub-band contains different frequency information of the image. The detail structure of the image lies on the high frequency sub-band and the overall structure lies on the low frequency sub-band. Apparently it is difficult to extract detail structure from the high frequency sub-bands. Enhancement of the detail structures is necessary in order to find out the calcifications on the mammograms, cracks on any object such as fuel plate, etc. In our proposed method contrast enhancement is achieved from high and medium frequency sub-band images by decomposing the image based on multi-scale Laplacian pyramid and enhancing contrast by suitable image processing. Standard Deviation-based Modified Adaptive contrast enhancement (SDMACE) technique is applied to enhance the low-contrast information on the sub-bands without overshooting noise. An alpha-trimmed mean filter is used in SDMACE for sharpness enhancement. After modifying all sub-band images, the final image is derived from reconstruction of the sub-band images from lower resolution level to upper resolution level including the residual image. To demonstrate the effectiveness of the algorithm an x-ray of a fuel plate and two mammograms are analyzed. Subjective evaluation is performed to evaluate the effectiveness of the algorithm. The proposed algorithm is compared with the well-known contrast limited adaptive histogram equalization (CLAHE) algorithm. Experimental results prove that the proposed algorithm offers improved contrast of the x-ray images.

  13. A theory of behavioral contrast.

    Science.gov (United States)

    Killeen, Peter R

    2014-11-01

    The reinforcers that maintain target instrumental responses also reinforce other responses that compete with them for expression. This competition, and its imbalance at points of transition between different schedules of reinforcement, causes behavioral contrast. The imbalance is caused by differences in the rates at which different responses come under the control of component stimuli. A model for this theory of behavioral contrast is constructed by expanding the coupling coefficient of MPR (Killeen, 1994). The coupling coefficient gives the degree of association of a reinforcer with the target response (as opposed to other competing responses). Competing responses, often identified as interim or adjunctive or superstitious behavior, are intrinsic to reinforcement schedules, especially interval schedules. In addition to that base-rate of competition, additional competing responses may spill over from the prior component, causing initial contrast; and they may be modulated by conditioned reinforcement or punishment from stimuli associated with subsequent component change, causing terminal contrast. A formalization of these hypotheses employed (a) a hysteresis model of off-target responses giving rise to initial contrast, and (b) a competing traces model of the suppression or enhancement of ongoing competitive responses by signals of following-schedule transition. The theory was applied to transient contrast, the following schedule effect, and the component duration effect. © Society for the Experimental Analysis of Behavior.

  14. 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.)

  15. Characteristics of Prison Hospice Patients: Medical History, Hospice Care, and End-of-Life Symptom Prevalence.

    Science.gov (United States)

    Cloyes, Kristin G; Berry, Patricia H; Martz, Kim; Supiano, Katherine

    2015-07-01

    Increasing numbers of prisoners in the United States are dying from age-related and chronic illnesses while incarcerated. This study is among the first to document characteristics of a population of prison hospice patients. Retrospective review of medical records for all patients admitted to the Louisiana State Penitentiary prison hospice program between January 1, 2004, and May 31, 2012 (N = 79) examined demographics, medical history, hospice diagnosis, length of stay, and end-of-life symptom prevalence on admission and during final 72 hours before death. Resulting data were contrasted with community-based end-of-life care study data, demonstrating a unique clinical profile of this group. As prisons consider adopting programs to meet the growing need for inmate end-of-life care, more research concerning the particular characteristics and unique needs of prison hospice patients will inform these efforts. © The Author(s) 2015.

  16. 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.

  17. Correlations Between Awareness of Illness (Insight) and History of Addiction in Heroin-Addicted Patients

    Science.gov (United States)

    Maremmani, Angelo Giovanni Icro; Rovai, Luca; Rugani, Fabio; Pacini, Matteo; Lamanna, Francesco; Bacciardi, Silvia; Perugi, Giulio; Deltito, Joseph; Dell’Osso, Liliana; Maremmani, Icro

    2012-01-01

    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 behavior. 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. PMID:22787450

  18. 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

  19. Young adults' sources of contraceptive information: variations based on demographic characteristics and sexual risk behaviors.

    Science.gov (United States)

    Khurana, Atika; Bleakley, Amy

    2015-02-01

    Sexual information sources used by young adults can influence their contraceptive knowledge and behaviors, yet little is known about sources most frequently used by young adults, especially by groups with histories of sexual risk involvement. Nationally representative data from 1800 unmarried young adults, aged 18-29 years, were analyzed to (1) examine the sources of contraceptive information most frequently used by young adults and (2) assess variations (if any) in source use based on demographic characteristics and sexual risk history (determined based on past sexual behaviors). "Doctors/nurses" was the most frequently used contraceptive information source reported by young adults. Significant variations existed in source use based on demographic characteristics and sexual risk history. Females were more likely to obtain contraceptive information from health care professionals, whereas males were more likely to report friends, partners, internet and television/radio as their frequently used source. Young adults with a sexual risk history were more likely to rely on doctors/nurses and less likely to report friends and internet as their frequently used source than those without a sexual risk history. Receiving contraceptive information from doctors/nurses was associated with greater accuracy in knowledge about contraceptive use and efficacy as compared to all other sources. Young adults' use of specific contraceptive information sources can vary based on their demographic characteristics and sexual risk involvement. Future research should identify better strategies to connect young adults, especially young males, with sexual risk histories to more reliable sources of information. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. 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.

  1. 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.

  2. Historical sampling reveals dramatic demographic changes in western gorilla populations

    Directory of Open Access Journals (Sweden)

    Guschanski Katerina

    2011-04-01

    Full Text Available Abstract Background Today many large mammals live in small, fragmented populations, but it is often unclear whether this subdivision is the result of long-term or recent events. Demographic modeling using genetic data can estimate changes in long-term population sizes while temporal sampling provides a way to compare genetic variation present today with that sampled in the past. In order to better understand the dynamics associated with the divergences of great ape populations, these analytical approaches were applied to western gorillas (Gorilla gorilla and in particular to the isolated and Critically Endangered Cross River gorilla subspecies (G. g. diehli. Results We used microsatellite genotypes from museum specimens and contemporary samples of Cross River gorillas to infer both the long-term and recent population history. We find that Cross River gorillas diverged from the ancestral western gorilla population ~17,800 years ago (95% HDI: 760, 63,245 years. However, gene flow ceased only ~420 years ago (95% HDI: 200, 16,256 years, followed by a bottleneck beginning ~320 years ago (95% HDI: 200, 2,825 years that caused a 60-fold decrease in the effective population size of Cross River gorillas. Direct comparison of heterozygosity estimates from museum and contemporary samples suggests a loss of genetic variation over the last 100 years. Conclusions The composite history of western gorillas could plausibly be explained by climatic oscillations inducing environmental changes in western equatorial Africa that would have allowed gorilla populations to expand over time but ultimately isolate the Cross River gorillas, which thereafter exhibited a dramatic population size reduction. The recent decrease in the Cross River population is accordingly most likely attributable to increasing anthropogenic pressure over the last several hundred years. Isolation of diverging populations with prolonged concomitant gene flow, but not secondary admixture, appears

  3. Genetic footprints of demographic expansion in North America, but not Amazonia, during the Late Quaternary

    Science.gov (United States)

    Lessa, Enrique P.; Cook, Joseph A.; Patton, James L.

    2003-01-01

    The biotic consequences of climate change have attracted considerable attention. In particular, the “refugial debate” centers on the possible retraction of habitats to limited areas that may have served as refuges for many associated species, especially during glaciations of the Quaternary. One prediction of such scenarios is that populations must have experienced substantial growth accompanying climatic amelioration and the occupation of newly expanded habitats. We used coalescence theory to examine the genetic evidence, or lack thereof, for late Pleistocene refugia of boreal North American and tropical Amazonian mammals. We found substantial and concordant evidence of demographic expansion in North American mammals, particularly at higher latitudes. In contrast, small mammals from western Amazonia appear to have experienced limited or no demographic expansion after the Late Pleistocene. Thus, demographic responses to climate change can be tracked genetically and appear to vary substantially across the latitudinal gradient of biotic diversity. PMID:12913123

  4. 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.

  5. 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 ...

  6. TEENAGE PREGNANCY: DEMOGRAPHICS, MATERNAL AND FOETAL OUTCOME

    OpenAIRE

    Radhika Gollapudi; Jagadeeshwari Sistla

    2016-01-01

    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 o...

  7. Using Twitter data for demographic research

    OpenAIRE

    Dilek Yildiz; Jo Munson; Agnese Vitali; Ramine Tinati; Jennifer A. Holland

    2017-01-01

    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 i...

  8. 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.

  9. Demographic Challenges in America’s Future,

    Science.gov (United States)

    1982-05-01

    3 Why Do Fertility Rates Change?’.................... 4 America’s Changing Age Structure .................. 10 III. INTERNAL POPULATION...Population’s Changing Age Structure .............. 10 6. The Shift Toward Smaller Communities.............. 14 7. The Shift to the Sunbelt, 1970-80...born couples) may virtually halt early in the next cen- tury. Unprecedented demographic changes are in store-in the popu- lation’s age structure , in

  10. 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

  11. Development of reprogenetics and its demographic aspects

    Directory of Open Access Journals (Sweden)

    Devedžić Mirjana M.

    2004-01-01

    Full Text Available The development of reprogenetics during the last two decades of the XX century has brought a new age of reproduction. The paper surveys different types of reprogenetics in a wider sense, i.e. different assisted reproductive technologies (ART that include manipulation of female reproductive cell out of a woman's womb. Development of reprogenetics is documented by available quantitative indicators of the number and success of ART procedures in developed countries at the beginning of the XXI century. Since 1978, when the first baby was born from in vitro fertilization, the number of children born that way has reached 1% of all children, and in some countries even over 3%. Moreover, existing documentation is incomplete and does not include all forms of assisted reproduction - in reality, the importance of assisted reproduction is even higher and becomes demographically significant. Hence the paper indicates existing and potential effects of the ART development on the demographic development i.e. on specific demographic aspects of this phenomenon. It also points out the effects on the level of fertility, on the changes of direct fertility determinants, and on the levels of mortality and infant mortality, as well as a new understanding of birth control, the possibility of affecting biological structures, and the changes of the fundaments of marriage and family. Development perspectives of reprogenetics are also being raised in the context of bioethical discussions and indicate ethical dilemmas related to assisted reproduction. Solutions to the dilemmas define the scope of applying new reproductive technologies in the future.

  12. Demographic change and carbon dioxide emissions.

    Science.gov (United States)

    O'Neill, Brian C; Liddle, Brant; Jiang, Leiwen; Smith, Kirk R; Pachauri, Shonali; Dalton, Michael; Fuchs, Regina

    2012-07-14

    Relations between demographic change and emissions of the major greenhouse gas carbon dioxide (CO(2)) have been studied from different perspectives, but most projections of future emissions only partly take demographic influences into account. We review two types of evidence for how CO(2) emissions from the use of fossil fuels are affected by demographic factors such as population growth or decline, ageing, urbanisation, and changes in household size. First, empirical analyses of historical trends tend to show that CO(2) emissions from energy use respond almost proportionately to changes in population size and that ageing and urbanisation have less than proportional but statistically significant effects. Second, scenario analyses show that alternative population growth paths could have substantial effects on global emissions of CO(2) several decades from now, and that ageing and urbanisation can have important effects in particular world regions. These results imply that policies that slow population growth would probably also have climate-related benefits. Copyright © 2012 Elsevier Ltd. All rights reserved.

  13. Rural Household Demographics, Livelihoods and the Environment.

    Science.gov (United States)

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

    2008-02-01

    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 studies have been conducted in either marginal (mountainous or arid) or frontier environments, especially Amazonia. Though the linkages are mediated by many complex and often context-specific factors, there is strong evidence that dependence on natural resources intensifies when households lose human and social capital through adult morbidity and mortality, and qualified evidence for the influence of environmental factors on household decision-making regarding fertility and migration. Two decades of research on lifecycles and land-cover change at the farm level have yielded a number of insights about how households make use of different land-use and natural resource management strategies at different stages. A thread running throughout the review is the importance of managing risk through livelihood diversification, ensuring future income security, and culture-specific norms regarding appropriate and desirable activities and demographic responses. Recommendations for future research are provided.

  14. 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.

  15. 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...

  16. 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 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...... reviewed. KEY POINTS : • Clinical features, risk factors and prevention of nephrogenic systemic fibrosis are reviewed • Patients with GFR below 30 ml/min/1.73 m ( 2 ) have increased risk of developing NSF • Low stability gadolinium contrast media show the strongest association with NSF • Following...

  17. 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.)

  18. 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.

  19. Contrasting drivers of reproductive ageing in albatrosses.

    Science.gov (United States)

    Froy, Hannah; Lewis, Sue; Nussey, Daniel H; Wood, Andrew G; Phillips, Richard A

    2017-09-01

    Age-related variation in reproductive performance is ubiquitous in wild vertebrate populations and has important consequences for population and evolutionary dynamics. The ageing trajectory is shaped by both within-individual processes, such as improvement and senescence, and the among-individual effects of selective appearance and disappearance. To date, few studies have compared the role of these different drivers among species or populations. In this study, we use nearly 40 years of longitudinal monitoring data to contrast the within- and among-individual processes contributing to the reproductive ageing patterns in three albatross species (two biennial and one annual breeder) and test whether these can be explained by differences in life histories. Early-life performance in all species increased with age and was predominantly influenced by within-individual improvements. However, reproductive senescence was detected in only two of the species. In the species exhibiting senescent declines, we also detected a terminal improvement in breeding success. This is suggestive of a trade-off between reproduction and survival, which was supported by evidence of selective disappearance of good breeders. We demonstrate that comparisons of closely related species which differ in specific aspects of their life history can shed light on the ecological and evolutionary forces shaping variation in ageing patterns. © 2017 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

  20. 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.

  1. Extreme genomic erosion after recurrent demographic bottlenecks in the highly endangered Iberian lynx

    OpenAIRE

    Abascal, Federico; Corvelo, Andr?; Cruz, Fernando; Villanueva-Ca?as, Jos? L.; Vlasova, Anna; Marcet-Houben, Marina; Mart?nez-Cruz, Bego?a; Cheng, Jade Yu; Prieto, Pablo; Quesada, V?ctor; Quilez, Javier; Li, Gang; Garc?a, Francisca; Rubio-Camarillo, Miriam; Frias, Leonor

    2016-01-01

    Background Genomic studies of endangered species provide insights into their evolution and demographic history, reveal patterns of genomic erosion that might limit their viability, and offer tools for their effective conservation. The Iberian lynx (Lynx pardinus) is the most endangered felid and a unique example of a species on the brink of extinction. Results We generate the first annotated draft of the Iberian lynx genome and carry out genome-based analyses of lynx demography, evolution, an...

  2. Industrial energy use and the human life history.

    Science.gov (United States)

    Burger, Oskar; Delong, John P; Hamilton, Marcus J

    2011-01-01

    The demographic rates of most organisms are supported by the consumption of food energy, which is used to produce new biomass and fuel physiological processes. Unlike other species, modern humans use 'extra-metabolic' energy sources acquired independent of physiology, which also influence demographics. We ask whether the amount of extra-metabolic energy added to the energy budget affects demographic and life history traits in a predictable way. Currently it is not known how human demographics respond to energy use, and we characterize this response using an allometric approach. All of the human life history traits we examine are significant functions of per capita energy use across industrialized populations. We find a continuum of traits from those that respond strongly to the amount of extra-metabolic energy used, to those that respond with shallow slopes. We also show that the differences in plasticity across traits can drive the net reproductive rate to below-replacement levels.

  3. 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…

  4. 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.)

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...

  12. 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

  13. Demographic Consequences of the Stalingrad Battle

    Directory of Open Access Journals (Sweden)

    Evgeniy F. Krinko

    2018-02-01

    Full Text Available The first information about the losses of the Red Army and the Wehrmacht in the Battle of Stalingrad, the deaths of the civilian population of the Stalingrad region during the Nazi occupation were published back in the years of the Great Patriotic War. Later many authors investigated these questions. In the early 1990s, Soviet losses were calculated by a group of specialists of the General Staff under the leadership of Colonel General G. F. Krivosheev. However, there are alternative points of view on this issue. In general, the demographic consequences of the Battle of Stalingrad as a complex scientific problem have not been sufficiently studied. The authors of the article consider different types of losses, mention major military associations and units that took part in the fights for Stalingrad, as well as the number of soldiers in military units. The special attention is paid to the losses of civilian population. According to the most conservative estimates, the military losses of both parties in the Stalingrad battle amounted to at least 2–2.5 million people. The population of the Stalingrad region declined as a result of evacuation, hostilities and occupation by more than 0.5 million people, or nearly by a quarter. Mass losses led to significant deformations in the demographic structure of the population of the Stalingrad and neighboring regions. The number of working age men suffere the especially sharp decline. These deformations had determined the unfavorable trends in the demographic development of the region for many decades. In the introductory part of the paper E.F. Krinko describes the main types of losses and correlation of military forces by the beginning of the Stalingrad Battle. The conclusions made by the author summarize the overall research results. M. V. Medvedev reveals specific types of military and civilian losses suffered as a result of the Stalingrad Battle.

  14. [Abortion in Brazil: a demographic approach].

    Science.gov (United States)

    Cecatti, José Guilherme; Guerra, Gláucia Virgínia de Queiroz Lins; Sousa, Maria Helena de; Menezes, Greice Maria de Souza

    2010-03-01

    To evaluate the prevalence of spontaneous and induced abortion reported by a sample of Brazilian women interviewed in the National Demographic Health Survey of 1996. This was a secondary analysis of the Brazilian DHS-96 database, with information from interviews with a representative sample of 12,612 women about their reproductive life, focusing on the prevalence of spontaneous and induced abortion in the last five years and the associated factors for the various regions of the country and for Brazil as a whole. The sampling method was implemented with a strategy selection in two stages, one for the households and the other for women. The prevalence of spontaneous and induced abortion was estimated for Brazil and regions, and the socio-demographic characteristics of the women were analyzed as a function of the abortion's experience. A multinomial regression model analysis was used for the identification of factors independently associated with both types of abortion; their OR and respective 95% CI are reported. The prevalence of reported spontaneous abortion was 14% and the prevalence of induced abortion was 2.4% for the country as a whole. The state with the highest prevalence of induced abortion was Rio de Janeiro with 6.5%, followed by the Northeast region with 3.1%. The places with the lowest prevalence were the state of São Paulo and the South region. Both spontaneous and induced abortion showed higher prevalences with increasing age of the women studied. Being from the urban area (OR=1.5; 95%CI=1.0-2.3), having had more than one live child (OR=2.2; 95%CI=1.5-3.2) and being non-white (OR=1.4; 95%CI=1.0-1.8) were the main risk factors for induced abortion. The non-modifiable risk factors for induced abortion identified in this study indicate the need for improvement of educational and contraceptive actions, with priority for these specific demographic groups.

  15. [Demographic Dynamics and Educational Inequality in Mexico].

    Science.gov (United States)

    Giorguli Saucedo, Silvia E; Vargas Valle, Eunice D; Ulloa, Viviana Salinas; Hubert, Celia; Potter, Joseph E

    This paper seeks to explore the link between educational processes and Mexico's demographic dynamic. In the tradition of thought on population and development, it has been hypothesized that the population growth rate, family size and migration influence the accumulation of human capital among the school-age population. This study explores the link between the academic performance of youth between the age of 14 and 23 and the youth dependency ratio, teenage fertility and internal and international migration, using data aggregated at the municipal level for the year 2000. The analysis uses indicators on the educational supply at the municipal level based on the administrative statistics of the Public Education Secretariat (SEP).

  16. Contemporary demographic changes of the Rasina district

    OpenAIRE

    Stričević, Ljiljana; Radivojević, Aleksandar; Golubović, Ninoslav; Miletić, Jelena; Milić, Jana

    2016-01-01

    Rasina District is faced with serious demographic problems at the beginning of the twenty-first century which are the consequence of long-term economic and social changes both in this area and the country as a whole. The basic problem is insufficient population regeneration, which further leads to other negative processes. One of the most important problems of Rasina District is the ageing of population, i.e., a drop in young population and a significant rise in old population. Therefore, the...

  17. Risk society and the second demographic transition

    Directory of Open Access Journals (Sweden)

    David R. Hall

    2002-12-01

    Full Text Available Prominent “risk society” theorists such as Giddens and Beck have identified risk as a fundamental organizing principle of contemporary society. Importantly, a major cause of risk awareness and anxiety in modern society is individualism . . a concept Lesthaeghe linked to changes in family formation. In this regard, of the types of risk discussed in the sociological literature, “interpersonal risks” associated with cohabitation, marriage, and parenting are of obvious salience. This paper explores how the modern “risk society” thesis, and the concept of interpersonal risk could materially contribute to understanding the second demographic transition.

  18. 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)

  19. Demographic estimation methods for plants with unobservable life-states

    Science.gov (United States)

    Kery, M.; Gregg, K.B.; Schaub, M.

    2005-01-01

    Demographic estimation of vital parameters in plants with an unobservable dormant state is complicated, because time of death is not known. Conventional methods assume that death occurs at a particular time after a plant has last been seen aboveground but the consequences of assuming a particular duration of dormancy have never been tested. Capture-recapture methods do not make assumptions about time of death; however, problems with parameter estimability have not yet been resolved. To date, a critical comparative assessment of these methods is lacking. We analysed data from a 10 year study of Cleistes bifaria, a terrestrial orchid with frequent dormancy, and compared demographic estimates obtained by five varieties of the conventional methods, and two capture-recapture methods. All conventional methods produced spurious unity survival estimates for some years or for some states, and estimates of demographic rates sensitive to the time of death assumption. In contrast, capture-recapture methods are more parsimonious in terms of assumptions, are based on well founded theory and did not produce spurious estimates. In Cleistes, dormant episodes lasted for 1-4 years (mean 1.4, SD 0.74). The capture-recapture models estimated ramet survival rate at 0.86 (SE~ 0.01), ranging from 0.77-0.94 (SEs # 0.1) in anyone year. The average fraction dormant was estimated at 30% (SE 1.5), ranging 16 -47% (SEs # 5.1) in anyone year. Multistate capture-recapture models showed that survival rates were positively related to precipitation in the current year, but transition rates were more strongly related to precipitation in the previous than in the current year, with more ramets going dormant following dry years. Not all capture-recapture models of interest have estimable parameters; for instance, without excavating plants in years when they do not appear aboveground, it is not possible to obtain independent timespecific survival estimates for dormant plants. We introduce rigorous

  20. DEMOGRAPHICAL AND MEDICAL GEOGRAPHY RESEARCHES IN BUCOWINA

    Directory of Open Access Journals (Sweden)

    Dorin DUMITRAS

    2010-02-01

    Full Text Available The article investigates the ecology factors of environment and medicaldemographycal situations of sickness rate and populations’mortality demonstrated with an example of urbanized landscapes of Bucowina. A greater corrective connection is revealed among cancer apathy (r=0.5-0.6, general dent rate (r=0.5, and an integral index of ecological safety of city’s landscape environment. The authors revealed backward (negative dependency among the increased harshness of drinking water and cancer pathology of digestion organs and abdominal cavity.This article deals with synthesis of medical-demographic study results of anthropic landscapes under the aspect of their utilization in order to increase human ecological conditions. One of the problems that authors tried to solve in the process of research lies indeveloping of theoretical and methodological thesis (based on combined analysis ofecological factors and demographical status in order to determine ecological situation inthe region and to evaluate life and activity conditions of population.

  1. 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.

  2. Contemporary demographic changes of the Rasina district

    Directory of Open Access Journals (Sweden)

    Stričević Ljiljana

    2016-01-01

    Full Text Available Rasina District is faced with serious demographic problems at the beginning of the twenty-first century which are the consequence of long-term economic and social changes both in this area and the country as a whole. The basic problem is insufficient population regeneration, which further leads to other negative processes. One of the most important problems of Rasina District is the ageing of population, i.e., a drop in young population and a significant rise in old population. Therefore, the population of Rasina District is already in the critical phase of demographic aging. Such age structure influences further economic development of this area at large. The decrease in young population, which is the carrier of future reproduction and regeneration of the population of this area, is evident. So as to stop or decelerate these processes, it is necessary to improve life conditions and ensure certain economic standard. Otherwise, these processes will not be stopped; they will be all the more intensified.

  3. 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.

  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. 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.

  6. 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

  7. Estimating relatedness and inbreeding using molecular markers and pedigrees: the effect of demographic history.

    Science.gov (United States)

    Robinson, S P; Simmons, L W; Kennington, W J

    2013-12-01

    Estimates of inbreeding and relatedness are commonly calculated using molecular markers, although the accuracy of such estimates has been questioned. As a further complication, in many situations, such estimates are required in populations with reduced genetic diversity, which is likely to affect their accuracy. We investigated the correlation between microsatellite- and pedigree-based coefficients of inbreeding and relatedness in laboratory populations of Drosophila melanogaster that had passed through bottlenecks to manipulate their genetic diversity. We also used simulations to predict expected correlations between marker- and pedigree-based estimates and to investigate the influence of linkage between loci and null alleles. Our empirical data showed lower correlations between marker- and pedigree-based estimates in our control (nonbottleneck) population than were predicted by our simulations or those found in similar studies. Correlations were weaker in bottleneck populations, confirming that extreme reductions in diversity can compromise the ability of molecular estimates to detect recent inbreeding events. However, this result was highly dependent on the strength of the bottleneck and we did not observe or predict any reduction in correlations in our population that went through a relatively severe bottleneck of N = 10 for one generation. Our results are therefore encouraging, as molecular estimates appeared robust to quite severe reductions in genetic diversity. It should also be remembered that pedigree-based estimates may not capture realized identity-by-decent and that marker-based estimates may actually be more useful in certain situations. © 2013 John Wiley & Sons Ltd.

  8. Genetic variation and inference of demographic histories in non-model species

    OpenAIRE

    Tison, Jean-Luc

    2014-01-01

    Both long-term environmental changes such as those driven by the glacial cycles and more recent anthropogenic impacts have had major effects on the past demography in wild organisms. Within species, these changes are reflected in the amount and distribution of neutral genetic variation. In this thesis, mitochondrial and microsatellite DNA was analysed to investigate how environmental and anthropogenic factors have affected genetic diversity and structure in four ecologically different animal ...

  9. 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

    of diversity. In this paper, we examine the effect of DNA damage on population genetic estimates of ancestral population size. We simulate data using standard coalescent simulations that include postmortem damage and show that estimates of effective population sizes are inflated around, or right after......, the sampling time of the ancestral DNA sequences. This bias leads to estimates of increasing, and then decreasing, population sizes, as observed in several recently published studies. We reanalyze a recently published data set of DNA sequences from the Bison (Bison bison/Bison priscus) and show that the signal...

  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. Life History and Demographic Drivers of Reservoir Competence for Three Tick-Borne Zoonotic Pathogens

    OpenAIRE

    Ostfeld, Richard S.; Levi, Taal; Jolles, Anna E.; Martin, Lynn B.; Hosseini, Parviez R.; Keesing, Felicia

    2014-01-01

    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 as...

  13. 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 ...

  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. 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.

  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 Riv...

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

    OpenAIRE

    Cridland, Julie M.; Tsutsui, Neil D.; Ram?rez, Santiago R.

    2017-01-01

    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 sequence...

  18. 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.

  19. Osmolality of nonionic contrast media.

    Science.gov (United States)

    Miklautz, H; Fichte, K; Wegscheider, K

    1989-01-01

    Solutions of different low osmolar contrast media (CM) obviously show clinically relevant differences in the osmolality despite equal iodine concentrations and similar molecular structure. To obtain precise and comparable data, the osmolality of five batches (usually) each of contrast media, iopamidol, iohexol, iopromide, and ioxaglate-all preparations commercially available-were measured by means of the vapor pressure method. The osmolality of the solutions of sodium meglumine ioxaglate with the same iodine concentration is lower than that of the nonionic CM examined. Iopromide showed the lowest osmolality and iohexol the highest value of the nonionic preparations. The differences are statistically significant as a rule. They are attributed to a varying association and hydration of the CM molecules in the solution.

  20. 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...

  1. Contrasting genetic metrics and patterns among naturalized rainbow trout (Oncorhynchus mykiss) in two Patagonian lakes differentially impacted by trout aquaculture

    OpenAIRE

    Canales‐Aguirre, Cristian B.; Seeb, Lisa W.; Seeb, James E.; Cádiz, María I.; Musleh, Selim S.; Arismendi, Ivan; Gajardo, Gonzalo; Galleguillos, Ricardo; Gomez‐Uchida, Daniel

    2017-01-01

    Abstract Different pathways of propagation and dispersal of non‐native species into new environments may have contrasting demographic and genetic impacts on established populations. Repeated introductions of rainbow trout (Oncorhynchus mykiss) to Chile in South America, initially through stocking and later through aquaculture escapes, provide a unique setting to contrast these two pathways. Using a panel of single nucleotide polymorphisms, we found contrasting genetic metrics and patterns amo...

  2. Contrast-enhanced digital mammography

    Energy Technology Data Exchange (ETDEWEB)

    Dromain, Clarisse [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)], E-mail: dromain@igr.fr; Balleyguier, Corinne; Adler, Ghazal [Department of Radiology, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Garbay, Jean Remi [Department of Surgery, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France); Delaloge, Suzette [Department of Medicine, Institut Gustave-Roussy, 39, rue Camille Desmoulins, 94805 Villejuif Cedex (France)

    2009-01-15

    CEDM is a recent development of digital mammography using the intra-venous injection of an iodinated contrast agent in conjunction with a mammography examination. Two techniques have been developed to perform CEDM examinations: the temporal subtraction technique with acquisition of high-energy images before and after contrast medium injection and the dual energy technique with acquisition of a pair of low and high-energy images only after contrast medium injection. The temporal subtraction technique offered the possibility to analyze the kinetic curve of enhancement of breast lesions, similarly to breast MRI. The dual energy technique do not provide information about the kinetic of tumor enhancement but allows the acquisition of multiples views of the same breast or bilateral examination and is less sensitive to patient motion than temporal CEDM. Initial clinical experience has shown the ability of CEDM to map the distribution of neovasculature induced by cancer using mammography. Moreover, previous studies have shown a superiority of MX + CEDM, either for the assessment of the probability of malignancy than for BIRADS assessment comparing to MX alone. The potential clinical applications are the clarification of mammographically equivocal lesions, the detection of occult lesions on standard mammography, particularly in dense breast, the determination of the extent of disease, the assessment of recurrent disease and the monitoring of the response to chemotherapy. CEDM should result in a simple way to enhance the detection and the characterization of breast lesions.

  3. Conceptual history and History of Education

    Directory of Open Access Journals (Sweden)

    Conrad VILANOU I TORRANO

    2013-11-01

    Full Text Available After noting the importance of linguistic turn in the field of historiography, the two leading currents in the field of conceptual history are identi- fied, the Cambridge school and Reinhart Koselleck’s Begriffsgeschichte. The paper focuses on the analysis of the latter trend in conceptual history, linked to the phi- losophical (Heidegger, Gadamer, political (Schmitt and historical (Dilthey tradi- tion within the German academic community. The paper then reviews the origin and nature of the History of Pedagogy, which arose as part of the classic History of Ideas and later gave rise, after the Second World War, to a Social History of Education. Finally, a conceptual History of Education is proposed that, in addi- tion to addressing the various conceptual strata included in the different terms, also takes into account the intellectual and cultural aspects through a return to discourses and pedadogic narratives.

  4. 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....

  5. 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....

  6. 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.

  7. Used planet: a global history.

    Science.gov (United States)

    Ellis, Erle C; Kaplan, Jed O; Fuller, Dorian Q; Vavrus, Steve; Klein Goldewijk, Kees; Verburg, Peter H

    2013-05-14

    Human use of land has transformed ecosystem pattern and process across most of the terrestrial biosphere, a global change often described as historically recent and potentially catastrophic for both humanity and the biosphere. Interdisciplinary paleoecological, archaeological, and historical studies challenge this view, indicating that land use has been extensive and sustained for millennia in some regions and that recent trends may represent as much a recovery as an acceleration. Here we synthesize recent scientific evidence and theory on the emergence, history, and future of land use as a process transforming the Earth System and use this to explain why relatively small human populations likely caused widespread and profound ecological changes more than 3,000 y ago, whereas the largest and wealthiest human populations in history are using less arable land per person every decade. Contrasting two spatially explicit global reconstructions of land-use history shows that reconstructions incorporating adaptive changes in land-use systems over time, including land-use intensification, offer a more spatially detailed and plausible assessment of our planet's history, with a biosphere and perhaps even climate long ago affected by humans. Although land-use processes are now shifting rapidly from historical patterns in both type and scale, integrative global land-use models that incorporate dynamic adaptations in human-environment relationships help to advance our understanding of both past and future land-use changes, including their sustainability and potential global effects.

  8. History of animal bioacoustics

    Science.gov (United States)

    Popper, Arthur N.; Dooling, Robert J.

    2002-11-01

    The earliest studies on animal bioacoustics dealt largely with descriptions of sounds. Only later did they address issues of detection, discrimination, and categorization of complex communication sounds. This literature grew substantially over the last century. Using the Journal of the Acoustical Society of America as an example, the number of papers that fall broadly within the realm of animal sound production, communication, and hearing rose from two in the partial first decade of the journal in the 1930's, to 20 in the 1970's, to 92 in the first 2 years of this millennium. During this time there has been a great increase in the diversity of species studied, the sophistication of the methods used, and the complexity of the questions addressed. As an example, the first papers in JASA focused on a guinea pig and a bird. In contrast, since the year 2000 studies are often highly comparative and include fish, birds, dolphins, dogs, ants, crickets, and snapping shrimp. This paper on the history of animal bioacoustics will consider trends in work over the decades and discuss the formative work of a number of investigators who have spurred the field by making critical theoretical and experimental observations.

  9. History of Polish gastrointestinal radiology.

    Science.gov (United States)

    Urbanik, A

    2003-12-01

    As early as several days after the publication of the information concerning Roentgen's discovery the first radiological examinations were performed in Poland. The new method was immediately introduced into medical practice, including gastroenterology. In that pioneer period the most important works were those by Walery Jaworski who was the first man in the world to perform an X-ray of gall stones as well as the stomach with the use of a contrast medium. In its more-than-a-hundred-year history Polish gastrointestinal radiology has attempted not only to catch up with the world science, but it also has made a considerable contribution to its development.

  10. How Can We Teach History through Television?

    Science.gov (United States)

    Bage, Grant

    1997-01-01

    Contrasts the ambivalent attitudes of teachers toward television and generalized research on teachers' uses of television, with detailed empirical evidence from primary school history coordinators describing their reactions to and expectations of the medium. The data describes a wide variety of reasons why television is educationally useful in the…

  11. History into Drama: The Perspective of "1 Henry IV."

    Science.gov (United States)

    Champion, Larry S.

    1978-01-01

    Contrasts Shakespeare's "Henry V" and "Henry IV" series, in which human interaction becomes history, with plays such as "Julius Caesar," which focus on psychological analysis and the internalized protagonist. (MB)

  12. 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

  13. 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.)

  14. From demographic dividend to demographic burden: The impact of population ageing on economic growth in Europe

    NARCIS (Netherlands)

    van der Gaag, N.L.; de Beer, J.A.A.

    2015-01-01

    In the coming years, the share of the working-age population in the total population will start to decline in all countries of the European Union. All other things remaining equal, this so-called demographic burden will have a downward effect on economic growth. This paper examines whether the

  15. Life History Patterns

    DEFF Research Database (Denmark)

    Jones, Owen

    2016-01-01

    Maximum longevity varies hugely across species, ranging from days to millennia. Reproductive output also varies by orders of magnitude. These patterns result from demographic age-trajectories of mortality and fertility, which show comparable diversity. The familiar demographic trajectories of hum...

  16. 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

  17. 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.

  18. Demographic perspectives on China and India.

    Science.gov (United States)

    Adlakha, A; Banister, J

    1995-04-01

    This paper compares levels and trends of population growth rates, age and sex composition, mortality, and fertility including family planning practices in the world's two most populous countries, China and India. Both countries are undergoing demographic transition but China is nearer than India to achieving a stationary population. Fertility in China has declined below replacement level while in India it is nearly one and a half children per woman above replacement level. Both countries have achieved large reductions in mortality but life expectancy at birth in China is currently about 10 years longer than in India. Both countries have young populations but China will precede India in the aging of population structure during the 21st century.

  19. Demographic variables in Auckland medical students.

    Science.gov (United States)

    Collins, J P; Jones, J; White, G R

    1993-07-28

    To review the important background details of students admitted to the Auckland School of Medicine over its 25 years. Data collected at the time of application on 2448 students who successfully gained entry to the course has been analysed and compared with similar demographic variables in the New Zealand population as a whole, and with some of the findings from a survey performed on the total student population enrolling at Auckland University during 1990. Successful applicants had a mean age of 18.6 years, 39.7% were females and 77% were born in New Zealand. Eighty-three percent were European, 3.6% Maori, 2.4% Pacific Islanders and 10.8% Chinese, Indian or other Asian. Sixty-three percent came from cities over 100,000, 16% being from towns less than 20,000 people. State schools were attended by 77% of entrants and 55% went to single sex schools. University students enrolling in 1990 came from affluent backgrounds with 70% of medical students that year being from socioeconomic levels one and two. Parental occupation was found to clearly influence the career choice of students. Auckland medical students are predominantly from large cities and affluent backgrounds with only those of European origin being admitted in the same proportion as they occupy in the New Zealand population. The high ratio of Asian students reflects their commitment to senior secondary school studies while the lower admission rate for Maori and Polynesian students is due in part to the large number who leave school without completing their secondary education. The possible impact of these demographic variables on recruitment and loss from the course and on the choice and location of practice is discussed.

  20. 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.

  1. 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.

  2. 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

  3. Document delivery services contrasting views

    CERN Document Server

    1999-01-01

    Design and maintain document delivery services that are ideal for academic patrons! In Document Delivery Services: Contrasting Views, you'll visit four university library systems to discover the considerations and challenges each library faced in bringing document delivery to its clientele. This book examines the questions about document delivery that are most pressing in the profession of library science. Despite their own unique experiences, you'll find common practices among all four?including planning, implementation of service, and evaluation of either user satisfaction and/or vendor per

  4. Demographic response of cutlassfish (Trichiurus japonicus and T. nanhaiensis) to fluctuating palaeo-climate and regional oceanographic conditions in the China seas.

    Science.gov (United States)

    He, Lijun; Zhang, Aibing; Weese, David; Li, Shengfa; Li, Jiansheng; Zhang, Jing

    2014-09-16

    Glacial cycles of the Quaternary have heavily influenced the demographic history of various species. To test the evolutionary impact of palaeo-geologic and climatic events on the demographic history of marine taxa from the coastal Western Pacific, we investigated the population structure and demographic history of two economically important fish (Trichiurus japonicus and T. nanhaiensis) that inhabit the continental shelves of the East China and northern South China Seas using the mitochondrial cytochrome b sequences and Bayesian Skyline Plot analyses. A molecular rate of 2.03% per million years, calibrated to the earliest flooding of the East China Sea shelf (70-140 kya), revealed a strong correlation between population sizes and primary production. Furthermore, comparison of the demographic history of T. japonicus populations from the East China and South China Seas provided evidence of the postglacial development of the Changjiang (Yangtze River) Delta. In the South China Sea, interspecific comparisons between T. japonicus and T. nanhaiensis indicated possible evolutionary responses to changes in palaeo-productivity that were influenced by East Asian winter monsoons. This study not only provides insight into the demographic history of cutlassfish but also reveals potential clues regarding the historic productivity and regional oceanographic conditions of the Western Pacific marginal seas.

  5. Demographic response of cutlassfish (Trichiurus japonicus and T. nanhaiensis) to fluctuating palaeo-climate and regional oceanographic conditions in the China seas

    Science.gov (United States)

    He, Lijun; Zhang, Aibing; Weese, David; Li, Shengfa; Li, Jiansheng; Zhang, Jing

    2014-01-01

    Glacial cycles of the Quaternary have heavily influenced the demographic history of various species. To test the evolutionary impact of palaeo-geologic and climatic events on the demographic history of marine taxa from the coastal Western Pacific, we investigated the population structure and demographic history of two economically important fish (Trichiurus japonicus and T. nanhaiensis) that inhabit the continental shelves of the East China and northern South China Seas using the mitochondrial cytochrome b sequences and Bayesian Skyline Plot analyses. A molecular rate of 2.03% per million years, calibrated to the earliest flooding of the East China Sea shelf (70–140 kya), revealed a strong correlation between population sizes and primary production. Furthermore, comparison of the demographic history of T. japonicus populations from the East China and South China Seas provided evidence of the postglacial development of the Changjiang (Yangtze River) Delta. In the South China Sea, interspecific comparisons between T. japonicus and T. nanhaiensis indicated possible evolutionary responses to changes in palaeo-productivity that were influenced by East Asian winter monsoons. This study not only provides insight into the demographic history of cutlassfish but also reveals potential clues regarding the historic productivity and regional oceanographic conditions of the Western Pacific marginal seas. PMID:25223336

  6. 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.

  7. 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.

  8. 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 periodontal disease. With respect to severe periodontal disease, significant (p 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.

  9. 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.

  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. Commercialization of vein contrast enhancement

    Science.gov (United States)

    Lovhoiden, Gunnar; Deshmukh, Harshal; Vrancken, Carlos; Zhang, Yong; Zeman, Herbert D.; Weinberg, Devin

    2003-07-01

    An ongoing clinical study of an experimental infrared (IR) device, the Vein Contrast Enhancer (VCE) that visualizes surface veins for medical access, indicates that a commercial device with the performance of the existing VCE would have significant clinical utility for even a very skilled phlebotomist. A proof-of-principle prototype VCE device has now been designed and constructed that captures IR images of surface veins with a commercial CCD camera, transfers the images to a PC for real-time software image processing to enhance the vein contrast, and projects the enhanced images back onto the skin with a modified commercial LCD projector. The camera and projector are mounted on precision slides allowing for precise mechanical alignment of the two optical axes and for measuring the effects of axes misalignment. Precision alignment of the captured and projected images over the entire field-of-view is accomplished electronically by software adjustments of the translation, scaling, and rotation of the enhanced images before they are projected back onto the skin. This proof-of-principle prototype will be clinically tested and the experience gained will lead to the development of a commercial device, OnTarget!, that is compact, easy to use, and will visualize accessible veins in almost all subjects needing venipuncture.

  12. High index contrast photonics platform

    Science.gov (United States)

    Chu, Sai T.; Little, Brent E.; Hryniewicz, John V.; Johnson, Fred G.; King, Oliver; Gill, Dave; Chen, Wenlu; Chen, Wei

    2005-10-01

    A new low-loss high-index-contrast photonics platform has been developed for integrated optics and microwave photonics. The platform consists of a material system that has an index contrast that is adjustable from 0 to 25% and which is processed using conventional CMOS tools. The platform allows one to four orders of magnitude reduction in the size of optical components compared with conventional planar technologies. As an example, meter long path lengths occupy coils that are millimeters in diameter. Microwave photonic building blocks that are enabled include large bit count programmable delay lines for beam steering and shaping that fit in less than a square centimeter and which have delays controllable from 5 fsec to 10 nsec. Also enabled are arrays of high order tunable filters, a hundred micrometers in size, having linewidths ranging from tens of MHz to tens of GHz. These filters can be tuned over several hundred GHz, and when placed in Vernier architectures can be tuned across the C band (5 THz). An optical chip typically consists of dozens of optical elements. Each element is placed in its own micro-control loop that consists of a thin film heater for thermo-optic control and a thermistor for electronic feedback. The micro-control loops impart intelligence to the optical chip.

  13. Contact double-contrast cholangiography.

    Science.gov (United States)

    Hishida, Y

    1979-05-01

    Recently operative cholangiography has become an essential step in biliary surgery. However, an usual technique in which x-ray film is set beneath the patient has its limitation in visualization of fine changes. The author devised a new technique to resolve this problem. A triangular mammography film designed for good positioning is vaccum-packed, coupled with an intensifying screen of the same size, and then is sterilized in advance. Barium solution mixed with Gascon drop (a defoaming agent) is used as contrast material. The duodenum and head of the pancreas are mobilized. Usual cholangiography is performed at first, introducing angiographic media through a catheter placed into the catheter placed into the common duct via the cystic duct. After this study a triangle film pack is set beneath the second part of the duodenum. Two to three milliliters of barium, 1 to 2 ml of Gascon, and 15 ml of air are pushed in; thus a contact double-contrast cholangiogram is obtained. This technique promises clear demonstration of the distal bile duct without risk, and even fine mucosal plicae may be discernible in the film.

  14. 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

  15. 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.

  16. Some Demographic Changes in the Population of Montenegro with the Projection of Future Demographic Development

    Directory of Open Access Journals (Sweden)

    Goran Rajović

    2016-04-01

    Full Text Available Dramatic demographic changes through which in recent decade’s passes Montenegrin society, the consequences arising from the new realities require a serious socio-political engagement. Process of population aging, that began the seventies of the 20th century, represents a significant problem. The process of demographic change was accompanied by an internal migration to major urban centers, primarily Podgorica and Montenegrin coast, leading to emptying the interior of Montenegro. Unfortunately, this development of the population structure of Montenegro opens a series of questions and challenges that would the creators of the future you should put high on the scale of its priorities. In this text we will point out on change of total number of citizens of Montenegro according to the base and chain indexes of 1921-2011 and population in Montenegro 2016–2091 (cohort model projections.

  17. Algeria. From demographic explosion to social rupture.

    Science.gov (United States)

    Fargues, P

    1994-01-01

    Large families were the rule 20-30 years ago in the Maghrib and less than ten years ago in the Mashriq, with couples typically bearing 7-9 children over the course of their reproductive lives. The overall rate of total fertility, however, declined by more than 50% by the beginning of the 1990s. Rates of population growth in all Mediterranean Arab countries have actually started to decline. This stabilization of actual population growth does not, however, mean that the demand for social services will level off. Demand for health and education services increases with the decrease in the number of infants and children per family. In the years ahead, there will also be more jobs to create and houses to build, with additional future costs attributed less to an increase in numbers than to rising aspirations. The author discusses rural-urban and regional differentials in fertility, the political economy of fertility, social change and women's status, the rapid and wide-scale diffusion of formal education, and how demographic change has set the stage for horizontal competition between peers and vertical competition among generations.

  18. Demographic and clinical features of adolescent parasuicides.

    Science.gov (United States)

    Neehall, J; Beharry, N

    1994-12-01

    The demographic, ethnic and clinical characteristics of 102 adolescents admitted to the Port-of Spain General Hospital over a 10-month period because of parasuicide were studied. The estimated rate of attempted suicide among adolescents was 94 per 100,000 of the hospital catchment population. Ninety per cent of the sample were females. Fifteen per cent had previously attempted suicide. Twenty-five per cent were clinically depressed, 22% had adjustment reactions, and in 49% no mental illness was detected. In 50% of cases, no further treatment was necessary after the first psychiatric interview. Intra-family conflicts were the most frequent reasons given for the attempted suicides. Girls of East Indian origin attempted suicide more frequently than those of African origin. Adolescents of mixed racial backgrounds attempted suicide less frequently than those of either African or East Indian origins. The findings of the study suggest a need for the adolescent psychiatric services to be upgraded, and for a review of the hospital policy of admitting all parasuicides of whatever degree as this is resulting in unnecessary and costly utilization of hospital beds.

  19. Demographic evidence for adaptive theories of aging.

    Science.gov (United States)

    Mitteldorf, J J

    2012-07-01

    Pleiotropic theories for the evolutionary origins of senescence have been ascendant for forty years (see, for example, G. Williams (1957) Evolution, 11, 398-411; T. Kirkwood (1977) Nature, 270, 301-304), and it is not surprising that interpreters of demographic data seek to frame their results in this context. But some of that evidence finds a much more natural explanation in terms of adaptive aging. Here we re-interpret the 1997 results of the Centenarian Study in Boston, which found in their sample of centenarian women an excess of late childbearing. The finding was originally interpreted as a selection effect: a metabolic link between late menopause and longevity. But we demonstrate that this interpretation is statistically strained, and that the data in fact indicate a causal link: bearing a child late in life induces a metabolic response that promotes longevity. This conclusion directly contradicts some pleiotropic theories of aging that postulate a "cost of reproduction", and it supports theories of aging as an adaptive genetic program.

  20. 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.

  1. 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.

  2. 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 ...

  3. 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

  4. 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 (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. 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...

  6. 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.

  7. 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

    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...... 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......, 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...

  8. 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 ...

  9. 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 ...

  10. History and Epic Poetry.

    Science.gov (United States)

    Turk, Thomas N.

    1994-01-01

    Describes the use of epic poetry in a combined English/history humanities class. Concludes that epic poetry, the combination of history and verse, helps students understand the continuity and meaning of the Western tradition. (CFR)

  11. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... CDC is Doing Blog: Public Health Matters Video: "The History of Bioterrorism" Recommend on Facebook Tweet Share ... or can be used as bioterrorist weapons. Watch the Complete Program "The History of Bioterroism" (26 min ...

  12. 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.

  13. Genet longevity and populatiln age structure of the clonal pioneer species Geum reptans based on demographic field data and projection matrix modelling

    OpenAIRE

    de Witte, Lucienne C.; Scherrer, Daniel; Stöcklin, Jürg

    2011-01-01

    Genet life span is a key demographic trait for understanding life history of plants. However, the longevity of clonal plants is hard to determine, especially when inter-ramet connections are short-lived and plants subsequently move independently of one another in space by means of an expansive growth strategy. In this study we estimated genet life span in the clonal pioneer species Geumreptans, living on glacier forelands, by using a projection matrix model based on demographic field data of ...

  14. 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.

  15. 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.

  16. Studying Ancient History.

    Science.gov (United States)

    Barrow, Robin

    1982-01-01

    Defends the value and relevance of the study of ancient history and classics in history curricula. The unique homogeneity of the classical period contributes to its instructional manageability. A year-long, secondary-level course on fifth-century Greece and Rome is described to illustrate effective approaches to teaching ancient history. (AM)

  17. Towards a European History

    NARCIS (Netherlands)

    H. van Dijk (Henk)

    2000-01-01

    textabstractAlthough historical writing is a profession with a long tradition, history as an academic discipline is strongly related to the development of the nation state in the nineteenth century. Notwithstanding specialisations like e.g. cultural history and social and economic history put less

  18. Mellem historie- og krigsvidenskab

    DEFF Research Database (Denmark)

    Hansen Schøning, Anna Sofie

    2016-01-01

    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...

  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. Temperature histories from tree rings and corals

    Energy Technology Data Exchange (ETDEWEB)

    Cook, E.R. [Tree-Ring Lab., Palisades, NY (United States)

    1995-05-01

    Recent temperature trends in long tree-ring and coral proxy temperature histories are evaluated and compared in an effort to objectively determine how anomalous twentieth century temperature changes have been. These histories mostly reflect regional variations in summer warmth from the tree rings and annual warmth from the corals. In the Northern Hemisphere. the North American tree-ring temperature histories and those from the north Polar Urals, covering the past 1000 or more years, indicate that the twentieth century has been anomalously warm relative to the past. In contrast, the tree-ring history from northern Fennoscandia indicates that summer temperatures during the {open_quote}Medieval Warm Period{close_quote} were probably warmer on average than those than during this century. In the Southern Hemisphere, the tree-ring temperature histories from South America show no indication of recent warming, which is in accordance with local instrumental records. In contrast, the tree-ring, records from Tasmania and New Zealand indicate that the twentieth century has been unusually warm particularly since 1960. The coral temperature histories from the Galapagos Islands and the Great Barrier Reef are in broad agreement with the tree-ring temperature histories in those sectors, with the former showing recent cooling and the latter showing recent warming that may be unprecedented. Overall, the regional temperature histories evaluated here broadly support the larger-scale evidence for anomalous twentieth century warming based on instrumental records. However, this warming cannot be confirmed as an unprecedented event in all regions. 38 refs., 3 figs., 2 tabs.

  1. 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.

  2. 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

  3. 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.

  4. 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

  5. Epidemiology and demographics of aggressive periodontitis.

    Science.gov (United States)

    Susin, Cristiano; Haas, Alex N; Albandar, Jasim M

    2014-06-01

    Epidemiologic studies of aggressive periodontitis have used different study designs and a range of examination methods and case definitions, and this greatly complicates the study of disease prevalence in populations. The wide range of disease case definitions, in particular, profoundly impacts the reported rate of disease, and the use of a standard disease definition is strongly recommended. Surveys of aggressive periodontitis that use only clinical examinations, without radiographic examination to confirm the presence of a distinctive pattern of tissue loss, may overestimate the prevalence of this disease, particularly when a low threshold of attachment loss is used. The prevalence of aggressive periodontitis varies significantly between populations, and differences in race/ethnicities seem to be a key factor. Studies consistently show that aggressive periodontitis is most prevalent in Africa and in populations of African descent and is least prevalent in Caucasians in Europe and North America. Among children and young adults the prevalence of this disease is higher in older than in younger age groups. Most studies show comparable disease prevalence in male and female subjects. These findings show that aggressive periodontitis is a significant health problem in certain populations. This review also highlights a lack of information on the epidemiology and demographics of this disease in many parts of the world, particularly in Asia and Africa. Epidemiologic studies of aggressive periodontitis in high-risk populations are important and could provide vital data on the determinants of this disease, and this information is needed for the establishment of effective health-promotion measures. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. China’s Demographic Limits to Economic Growth

    Science.gov (United States)

    2012-06-01

    Hawaii at Manoa, 2005). 10 Ibid. 11 Wang Feng and Andrew Mason, "The Demographic Factor in China’s Transition," in China’s Great Economic Transformation...suffering to the population and serious damage to the economy,”106 the demographic transition did not end upon the Communist takeover . From 1953 to 1958...Population Studies Program, University of Hawaii at Manoa, 2005. Montgomery, Keith. "The Demographic Transition." March 18, 2008. http

  7. Demographic Transitions and Economic Miracles in Emerging Asia

    OpenAIRE

    David E. Bloom; Jeffrey G. Williamson

    1997-01-01

    The demographic transition a change from high to low rates of mortality and fertility has been more dramatic in East Asia during this century than in any other region or historical period. By introducing demographic variables into an empirical model of economic growth, this essay shows that this transition has contributed substantially to East Asia's so-called economic miracle. The 'miracle' occurred in part because East Asia's demographic transition resulted in its working-age population gro...

  8. Demographic and clinical profiles in patients with acute urticaria.

    Science.gov (United States)

    Sánchez-Borges, M; Capriles-Hulett, A; Caballero-Fonseca, F

    2015-01-01

    Urticaria is a common cause for consultation in general and specialised medical practices. There is scarce information on the characteristics of patients suffering acute urticaria in Latin America. To investigate demographic and clinical features of patients with acute urticaria attending two allergy clinics in Caracas, Venezuela. A prospective study of all new patients who consulted during a three-year period because of acute urticaria. Information on age, gender, symptom duration, previous medical history, body distribution of wheals and angio-oedema, laboratory investigations, skin prick tests, and pharmacological treatment, was collected. Patients were classified according to their age as children/adolescents and adults. Two hundred and forty eight patients (177 adults and 71 children) were studied. Acute urticaria was more frequent in middle-aged atopic female patients. Lesions more often involved upper and lower limbs and head, and 31% of patients exhibited generalised urticaria. Laboratory investigations, performed only in selected cases, did not contribute to the final diagnosis. Most frequent subtypes of acute urticaria were spontaneous, dermographic, papular, and drug-induced urticaria. Most patients were treated with non-sedating antihistamines, with increased use of cetirizine and levocetirizine in children, while 5.6% of children and 20.3% of adults required the addition of short courses of systemic corticosteroids. Acute urticaria is a frequent cause of consultation for allergists, affecting more often middle-aged female atopic patients. The use of extensive complementary tests does not seem to be cost-effective for this clinical condition. Spontaneous, dermographic, papular and drug-induced urticaria are the most common subtypes. Copyright © 2014 SEICAP. Published by Elsevier Espana. All rights reserved.

  9. 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.

  10. Planning Marine Reserve Networks for Both Feature Representation and Demographic Persistence Using Connectivity Patterns.

    Directory of Open Access Journals (Sweden)

    Michael Bode

    Full Text Available Marine reserve networks must ensure the representation of important conservation features, and also guarantee the persistence of key populations. For many species, designing reserve networks is complicated by the absence or limited availability of spatial and life-history data. This is particularly true for data on larval dispersal, which has only recently become available. However, systematic conservation planning methods currently incorporate demographic processes through unsatisfactory surrogates. There are therefore two key challenges to designing marine reserve networks that achieve feature representation and demographic persistence constraints. First, constructing a method that efficiently incorporates persistence as well as complementary feature representation. Second, incorporating persistence using a mechanistic description of population viability, rather than a proxy such as size or distance. Here we construct a novel systematic conservation planning method that addresses both challenges, and parameterise it to design a hypothetical marine reserve network for fringing coral reefs in the Keppel Islands, Great Barrier Reef, Australia. For this application, we describe how demographic persistence goals can be constructed for an important reef fish species in the region, the bar-cheeked trout (Plectropomus maculatus. We compare reserve networks that are optimally designed for either feature representation or demographic persistence, with a reserve network that achieves both goals simultaneously. As well as being practically applicable, our analyses also provide general insights into marine reserve planning for both representation and demographic persistence. First, persistence constraints for dispersive organisms are likely to be much harder to achieve than representation targets, due to their greater complexity. Second, persistence and representation constraints pull the reserve network design process in divergent directions, making it

  11. The Method of Culture Contrast

    DEFF Research Database (Denmark)

    Hasse, Cathrine; Trentemøller, Stine; Motzkau, Johanna

    2009-01-01

    In this article, we suggest that research is a practical activity building on local category systems belonging specifically to research (etic categories) as well as categories belonging specifically to the national culture of the researcher (emic categories) (Pike 1967). Much cross-cultural resea......In this article, we suggest that research is a practical activity building on local category systems belonging specifically to research (etic categories) as well as categories belonging specifically to the national culture of the researcher (emic categories) (Pike 1967). Much cross......-cultural research can be argued to rest on what has been called implicit comparisons (Nader 1994) of such categorisations. We assume that research of local activities, such as schooling and higher education, is influenced by the researcher's emic and etic categorisations. To get beyond the risk of reproducing......) framework on which the research is conducted. First we present a recent study of European universities as culturally diverse working places and we present an approach in which the researcher's emic and etic categorisations can be challenged when contrasted with each other (Hasse & Trentemøller 2008). Second...

  12. Integral equations with contrasting kernels

    Directory of Open Access Journals (Sweden)

    Theodore Burton

    2008-01-01

    Full Text Available In this paper we study integral equations of the form $x(t=a(t-\\int^t_0 C(t,sx(sds$ with sharply contrasting kernels typified by $C^*(t,s=\\ln (e+(t-s$ and $D^*(t,s=[1+(t-s]^{-1}$. The kernel assigns a weight to $x(s$ and these kernels have exactly opposite effects of weighting. Each type is well represented in the literature. Our first project is to show that for $a\\in L^2[0,\\infty$, then solutions are largely indistinguishable regardless of which kernel is used. This is a surprise and it leads us to study the essential differences. In fact, those differences become large as the magnitude of $a(t$ increases. The form of the kernel alone projects necessary conditions concerning the magnitude of $a(t$ which could result in bounded solutions. Thus, the next project is to determine how close we can come to proving that the necessary conditions are also sufficient. The third project is to show that solutions will be bounded for given conditions on $C$ regardless of whether $a$ is chosen large or small; this is important in real-world problems since we would like to have $a(t$ as the sum of a bounded, but badly behaved function, and a large well behaved function.

  13. Evaluation of the commonest site, demographic profile and most effective therapy in scabies

    Directory of Open Access Journals (Sweden)

    Das Sudip

    2006-01-01

    Full Text Available The study was planned to find out commonest sites of scabies in Indian patients. Attempt was made to study the demographic profile i.e., the common age groups, affection of family members, friends or sexual partners, type of skin lesions, history of previous affection of scabies, coassociation with STDs, and to find out the most effective treatment of scabies. Our study showed that genitalia and finger webs were the most common sites and papular lesions were by far the commonest lesion in scabies. Oral lvermectin remained the most effective drug closely followed by topical 5% permethrin cream.

  14. DEMOGRAPHIC IMPERATIVES OF MODERNIZATION PROCESSES IN EDUCATIONAL POLICY (FOR EXAMPLE REGIONS OF INNER ASIA

    Directory of Open Access Journals (Sweden)

    Tatiana Innokentievna Garmaeva

    2017-02-01

    Methodological basis of the research are the historical, sociological methods, and also systematic and structural-functional analysis. The results of the research will help to determine the demographic processes in the cross-border regions of Inner Asia, in particular in the Republic of Buryatia (Russia, Autonomous Region of Inner Mongolia (China, Mongolia; the possibility of the higher education system’s development in the designated regions. The obtained results can be used in the work of public authorities involved in the development of public policy in the field of education, in reading of the lecture course, special seminars on pedagogy and history of education for the students and specialists of humanities.

  15. Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol.

    Science.gov (United States)

    Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

    2014-10-06

    Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR).The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15-87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma.

  16. Breakthrough reactions of iodinated and gadolinium contrast media after oral steroid premedication protocol

    International Nuclear Information System (INIS)

    Jingu, Akiko; Fukuda, Junya; Taketomi-Takahashi, Ayako; Tsushima, Yoshito

    2014-01-01

    Adverse reactions to iodinated and gadolinium contrast media are an important clinical issue. Although some guidelines have proposed oral steroid premedication protocols to prevent adverse reactions, some patients may have reactions to contrast media in spite of premedication (breakthrough reaction; BTR). The purpose of this study was to assess the frequency, type and severity of BTR when following an oral steroid premedication protocol. All iodinated and gadolinium contrast-enhanced radiologic examinations between August 2011 and February 2013 for which the premedication protocol was applied in our institution were assessed for BTRs. The protocol was applied to a total of 252 examinations (153 patients, ages 15–87 years; 63 males, 90 females). Of these, 152 were for prior acute adverse reactions to contrast media, 85 were for a history of bronchial asthma, and 15 were for other reasons. There were 198 contrast enhanced CTs and 54 contrast enhanced MRIs. There were nine BTR (4.5%) for iodinated contrast media, and only one BTR (1.9%) for gadolinium contrast media: eight were mild and one was moderate. No patient who had a mild index reaction (IR) had a severe BTR. Incidence of BTRs when following the premedication protocol was low. This study by no means proves the efficacy of premedication, but provides some support for following a premedication protocol to improve safety of contrast-enhanced examinations when prior adverse reactions are mild, or when there is a history of asthma

  17. 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

  18. 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

  19. Demographic situation and development in Nepal.

    Science.gov (United States)

    Pradhanang, A L

    1983-01-01

    In Nepal economic development has not kept pace with population growth. The government must develop a vigorous dual program to promote economic development and to reduce population growth. Previous efforts to promote economic development, using a macrolevel approach, failed to improve the economic conditions for the majority of Nepal's citizens. The macrolevel approach required large capital outlays and resulted in an influx of foreign investors and the importation of inappropriate technologies from the developed countries. As a result, urbanization and pollution increased, and both the proportion and the absolute number of poor persons increased. A microlevel approach is now being instituted by the government, and an emphasis is being placed on meeting the basic needs of the poor and on promoting economic self-sufficiency. The country has extensive water resources which can be tapped for irrigation purposes. Nepal also has rich mineral deposits which should be exploited in such a way as to ensure that the profits accrue to the Nepalese. The country has an abundance of manpower resources, but there is a dearth of skilled workers. Unemployment, especially in rural areas, is a serious problem, and efforts should be made to either develop the agricultural sector or create new jobs in other sectors. Nepal's demographic problems include rapid population growth, the influx of a large number of migrants from India, and a high rural to urban migration rate. In 1981, the population size was 15 million, the annual growth rate was 2.6%, the crude birth rate was 38.5, the crude death rate was 18.4, and life expectancy was 47.5 years. The government is currently developing plans 1) to promote the development of core sectors of the economy, 2) to provide family planning services for the poor, 3) to meet the basic needs of rural residents in order to stem the flow of migration to urban areas, 4) to mobilize women to play an active role in the country's development and population

  20. Laser speckle contrast imaging in biomedical optics.

    Science.gov (United States)

    Boas, David A; Dunn, Andrew K

    2010-01-01

    First introduced in the 1980s, laser speckle contrast imaging is a powerful tool for full-field imaging of blood flow. Recently laser speckle contrast imaging has gained increased attention, in part due to its rapid adoption for blood flow studies in the brain. We review the underlying physics of speckle contrast imaging and discuss recent developments to improve the quantitative accuracy of blood flow measures. We also review applications of laser speckle contrast imaging in neuroscience, dermatology and ophthalmology.