WorldWideScience

Sample records for contrasting demographic histories

  1. Contrasting demographic histories of the neighboring bonobo and chimpanzee

    DEFF Research Database (Denmark)

    Hvilsom, Christina; Carlsen, Frands; Heller, Rasmus

    2014-01-01

    analyzed complete mitochondrial genomes representing all four recognized chimpanzee subspecies and the bonobo to infer the recent demographic history and used simulations to exclude a confounding effect of population structure. Our genus-wide Bayesian coalescent-based analysis revealed surprisingly...... dissimilar demographic histories of the chimpanzee subspecies and the bonobo, despite their overlapping habitat requirements. Whereas the central and eastern chimpanzee subspecies were inferred to have expanded tenfold between around 50,000 and 80,000 years ago and today, the population size...

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

    Science.gov (United States)

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

    2015-08-01

    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

  3. Contrasting population genetic structure among freshwater-resident and anadromous lampreys: the role of demographic history, differential dispersal and anthropogenic barriers to movement

    Science.gov (United States)

    Bracken, Fiona S A; Hoelzel, A Rus; Hume, John B; Lucas, Martyn C

    2015-01-01

    The tendency of many species to abandon migration remains a poorly understood aspect of evolutionary biology that may play an important role in promoting species radiation by both allopatric and sympatric mechanisms. Anadromy inherently offers an opportunity for the colonization of freshwater environments, and the shift from an anadromous to a wholly freshwater life history has occurred in many families of fishes. Freshwater-resident forms have arisen repeatedly among lampreys (within the Petromyzontidae and Mordaciidae), and there has been much debate as to whether anadromous lampreys, and their derived freshwater-resident analogues, constitute distinct species or are divergent ecotypes of polymorphic species. Samples of 543 European river lamprey Lampetra fluviatilis (mostly from anadromous populations) and freshwater European brook lamprey Lampetra planeri from across 18 sites, primarily in the British Isles, were investigated for 13 polymorphic microsatellite DNA loci, and 108 samples from six of these sites were sequenced for 829 bp of mitochondrial DNA (mtDNA). We found contrasting patterns of population structure for mtDNA and microsatellite DNA markers, such that low diversity and little structure were seen for all populations for mtDNA (consistent with a recent founder expansion event), while fine-scale structuring was evident for nuclear markers. Strong differentiation for microsatellite DNA loci was seen among freshwater-resident L. planeri populations and between L. fluviatilis and L. planeri in most cases, but little structure was evident among anadromous L. fluviatilis populations. We conclude that postglacial colonization founded multiple freshwater-resident populations with strong habitat fidelity and limited dispersal tendencies that became highly differentiated, a pattern that was likely intensified by anthropogenic barriers. PMID:25689694

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

    African Journals Online (AJOL)

    STORAGESEVER

    2008-10-20

    Oct 20, 2008 ... In order to estimate the demographic history and genetic structure of. Epinephelus ... using DNA sequence data from the 5' end of the control region. ... on the aquaculture and biology of E. akaara, and Deng ... evolutionary history of the species. .... at low frequency are more likely to be new, θл is a useful.

  5. Inferring Demographic History Using Two-Locus Statistics.

    Science.gov (United States)

    Ragsdale, Aaron P; Gutenkunst, Ryan N

    2017-06-01

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

  6. Genealogy and Demographic History of a Widespread Amphibian throughout Indochina.

    Science.gov (United States)

    Blair, Christopher; Davy, Christina M; Ngo, Andre; Orlov, Nikolai L; Shi, Hai-tao; Lu, Shun-qing; Gao, Lan; Rao, Ding-qi; Murphy, Robert W

    2013-01-01

    Relatively little is known about spatial patterns of cryptic diversity in tropical species and the processes that generate them. Few studies examine the geographic distribution of genetic lineages in Southeast Asia, an area hypothesized to harbor substantial cryptic diversity. We investigated the evolutionary history of Asian tree frogs of the Polypedates leucomystax complex (n = 172) based on 1800 bp of the mtDNA genes ND1 and cytochrome b and tested hypotheses pertaining to climate, geology, and dispersal patterns. Analyses revealed substantial genetic diversity and lineage divergence throughout the region with evidence for widespread sympatric lineages and a general north versus south clustering. Relaxed molecular clock analysis and tests for demographic expansion identified an initial cladogenesis during the Miocene with subsequent Plio-Pleistocene diversification, with the former corresponding to periods of increased aridity and the onset of monsoonal weather systems. Rates of diversification were relatively constant until the Early Pleistocene when rates increased exponentially. We found equivocal evidence for isolation-by-distance and a potential role of some landscape features as partial barriers to dispersal. Finally, our analyses showed that divergence between insular and mainland populations occurred before Homo sapiens colonized Southeast Asia, suggesting that historical human-mediated dispersal did not drive insular diversification. Our results suggested that demographic expansion in the Late Pleistocene resulted in widespread sympatric lineages in the P. leucomystax complex throughout southern China and Indochina and further clarified the evolutionary history of lineages within P. leucomystax.

  7. Demographic analysis of continuous-time life-history models

    NARCIS (Netherlands)

    de Roos, A.M.

    2008-01-01

    I present a computational approach to calculate the population growth rate, its sensitivity to life-history parameters and associated statistics like the stable population distribution and the reproductive value for exponentially growing populations, in which individual life history is described as

  8. Demographic analysis of continuous-time life-history models

    NARCIS (Netherlands)

    A.M. de Roos

    2008-01-01

    I present a computational approach to calculate the population growth rate, its sensitivity to life-history parameters and associated statistics like the stable population distribution and the reproductive value for exponentially growing populations, in which individual life history is described as

  9. [Hereditary spherocytosis: Review. Part I. History, demographics, pathogenesis, and diagnosis].

    Science.gov (United States)

    Donato, Hugo; Crisp, Renée Leonor; Rapetti, María Cristina; García, Eliana; Attie, Myriam

    2015-01-01

    Hereditary spherocytosis is the most frequent hereditary anemia excluding beta thalassemia in Argentina. Historical, demographic, genetic and pathogenic aspects of the disease are reviewed, and confirmatory laboratory tests are described. Special characteristics on the outcome of the disease in our population and prevalent protein deficiencies in our country are described. Emphasis is given on new available laboratory tests, which allow an earlier diagnosis using volume of blood samples significantly smaller than required for conventional tests.

  10. Intraspecific life history variation in contrasting habitats: Insights from an obligate symbiotic organism.

    Science.gov (United States)

    Merinero, Sonia; Aragón, Gregorio; Martínez, Isabel

    2017-07-28

    Life history theory predicts that plants in unfavorable habitats for juvenile growth and survival will commence reproduction at smaller sizes and exhibit higher reproductive allocations than those in favorable habitats. The scope of life history theory will increase if these predictions apply to a broad range of organisms. Populations of organisms in contrasting habitats may experience different demographic rates. Thus, we compared the demography and life history traits of a lichen species in contrasting habitats. We compared the abundance, growth, mortality, and reproductive strategy (threshold size for reproduction and reproductive allometry) of epiphytic and saxicolous populations of the asexually reproducing lichen Lobarina scrobiculata in two oak forests in central Spain. The growth rates of saxicolous individuals were two times faster than those of epiphytic individuals. Epiphytic specimens exhibited a smaller threshold size for reproduction and a higher reproductive allocation than their saxicolous counterparts. The populations hosted by trees were two times larger than those on rocks (13,788 vs. 6629 individuals, respectively). The mortality rate did not vary between habitats. Our results demonstrate that contrasting habitats selected for differences in the demography and life history traits of a lichen species. Consistent with life history theory predictions, in the habitat with slower growth, L. scrobiculata started to reproduce at a smaller size and its reproductive allocation was higher. This study extends the scope of life history theory and improves our understanding of life history patterns and variations in overlooked taxa such as lichens. © 2017 Botanical Society of America.

  11. Demographic history of the Tibetan antelope Pantholops hodgsoni(chiru)

    Institute of Scientific and Technical Information of China (English)

    Yu-Rong DU; Song-Chang GUO; Zhao-Feng WANG; Hai-Xing CI; Zhen-Yuan CAI; Qian ZHANG; Jian-Ping SU; Jian-Quan LIU

    2010-01-01

    The Tibetan antelope(chiru,Pantholops hodgsoni),a heavily poached species and symbol of the QinghaiTibetan Plateau(QTP),is noted worldwide for its special calving migration.This species originated in the early Quaternary and it is interesting to know how the following climatic oscillations affected its demographic dynamics in the climate-sensitive QTP.In this study,we analyzed the mitochondrial D-loop region from 312 individuals sampled in all of the six major populations.We found high rates of gene flow and little genetic differentiation between populations,suggesting that the calving migration may have homogenized the genetic pool of this species.Both mismatch distribution analyses and coalescent simulations suggested that this species experienced a demographic expansion approximately 600-200 Kyt following the retreat of the large glaciers developed in the QTP at 800-600 Kyr,rather than at the end of the last glacial age,as previously suggested based on a limited sample size.In addition,we found evidence of a chiru population decrease probably related to the human settings at the QTP during the middle Holocene.

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

    DEFF Research Database (Denmark)

    Harris, Kelley; Nielsen, Rasmus

    2013-01-01

    There has been much recent excitement about the use of genetics to elucidate ancestral history and demography. Whole genome data from humans and other species are revealing complex stories of divergence and admixture that were left undiscovered by previous smaller data sets. A central challenge...

  13. Formal linguistics as a cue to demographic history.

    Science.gov (United States)

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

    2016-06-20

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

  14. Demographic history and rare allele sharing among human populations

    Science.gov (United States)

    Gravel, Simon; Henn, Brenna M.; Gutenkunst, Ryan N.; Indap, Amit R.; Marth, Gabor T.; Clark, Andrew G.; Yu, Fuli; Gibbs, Richard A.; Bustamante, Carlos D.; Altshuler, David L.; Durbin, Richard M.; Abecasis, Gonçalo R.; Bentley, David R.; Chakravarti, Aravinda; Clark, Andrew G.; Collins, Francis S.; De La Vega, Francisco M.; Donnelly, Peter; Egholm, Michael; Flicek, Paul; Gabriel, Stacey B.; Gibbs, Richard A.; Knoppers, Bartha M.; Lander, Eric S.; Lehrach, Hans; Mardis, Elaine R.; McVean, Gil A.; Nickerson, Debbie A.; Peltonen, Leena; Schafer, Alan J.; Sherry, Stephen T.; Wang, Jun; Wilson, Richard K.; Gibbs, Richard A.; Deiros, David; Metzker, Mike; Muzny, Donna; Reid, Jeff; Wheeler, David; Wang, Jun; Li, Jingxiang; Jian, Min; Li, Guoqing; Li, Ruiqiang; Liang, Huiqing; Tian, Geng; Wang, Bo; Wang, Jian; Wang, Wei; Yang, Huanming; Zhang, Xiuqing; Zheng, Huisong; Lander, Eric S.; Altshuler, David L.; Ambrogio, Lauren; Bloom, Toby; Cibulskis, Kristian; Fennell, Tim J.; Gabriel, Stacey B.; Jaffe, David B.; Shefler, Erica; Sougnez, Carrie L.; Bentley, David R.; Gormley, Niall; Humphray, Sean; Kingsbury, Zoya; Koko-Gonzales, Paula; Stone, Jennifer; McKernan, Kevin J.; Costa, Gina L.; Ichikawa, Jeffry K.; Lee, Clarence C.; Sudbrak, Ralf; Lehrach, Hans; Borodina, Tatiana A.; Dahl, Andreas; Davydov, Alexey N.; Marquardt, Peter; Mertes, Florian; Nietfeld, Wilfiried; Rosenstiel, Philip; Schreiber, Stefan; Soldatov, Aleksey V.; Timmermann, Bernd; Tolzmann, Marius; Egholm, Michael; Affourtit, Jason; Ashworth, Dana; Attiya, Said; Bachorski, Melissa; Buglione, Eli; Burke, Adam; Caprio, Amanda; Celone, Christopher; Clark, Shauna; Conners, David; Desany, Brian; Gu, Lisa; Guccione, Lorri; Kao, Kalvin; Kebbel, Andrew; Knowlton, Jennifer; Labrecque, Matthew; McDade, Louise; Mealmaker, Craig; Minderman, Melissa; Nawrocki, Anne; Niazi, Faheem; Pareja, Kristen; Ramenani, Ravi; Riches, David; Song, Wanmin; Turcotte, Cynthia; Wang, Shally; Mardis, Elaine R.; Wilson, Richard K.; Dooling, David; Fulton, Lucinda; Fulton, Robert; Weinstock, George; Durbin, Richard M.; Burton, John; Carter, David M.; Churcher, Carol; Coffey, Alison; Cox, Anthony; Palotie, Aarno; Quail, Michael; Skelly, Tom; Stalker, James; Swerdlow, Harold P.; Turner, Daniel; De Witte, Anniek; Giles, Shane; Gibbs, Richard A.; Wheeler, David; Bainbridge, Matthew; Challis, Danny; Sabo, Aniko; Yu, Fuli; Yu, Jin; Wang, Jun; Fang, Xiaodong; Guo, Xiaosen; Li, Ruiqiang; Li, Yingrui; Luo, Ruibang; Tai, Shuaishuai; Wu, Honglong; Zheng, Hancheng; Zheng, Xiaole; Zhou, Yan; Li, Guoqing; Wang, Jian; Yang, Huanming; Marth, Gabor T.; Garrison, Erik P.; Huang, Weichun; Indap, Amit; Kural, Deniz; Lee, Wan-Ping; Leong, Wen Fung; Quinlan, Aaron R.; Stewart, Chip; Stromberg, Michael P.; Ward, Alistair N.; Wu, Jiantao; Lee, Charles; Mills, Ryan E.; Shi, Xinghua; Daly, Mark J.; DePristo, Mark A.; Altshuler, David L.; Ball, Aaron D.; Banks, Eric; Bloom, Toby; Browning, Brian L.; Cibulskis, Kristian; Fennell, Tim J.; Garimella, Kiran V.; Grossman, Sharon R.; Handsaker, Robert E.; Hanna, Matt; Hartl, Chris; Jaffe, David B.; Kernytsky, Andrew M.; Korn, Joshua M.; Li, Heng; Maguire, Jared R.; McCarroll, Steven A.; McKenna, Aaron; Nemesh, James C.; Philippakis, Anthony A.; Poplin, Ryan E.; Price, Alkes; Rivas, Manuel A.; Sabeti, Pardis C.; Schaffner, Stephen F.; Shefler, Erica; Shlyakhter, Ilya A.; Cooper, David N.; Ball, Edward V.; Mort, Matthew; Phillips, Andrew D.; Stenson, Peter D.; Sebat, Jonathan; Makarov, Vladimir; Ye, Kenny; Yoon, Seungtai C.; Bustamante, Carlos D.; Clark, Andrew G.; Boyko, Adam; Degenhardt, Jeremiah; Gravel, Simon; Gutenkunst, Ryan N.; Kaganovich, Mark; Keinan, Alon; Lacroute, Phil; Ma, Xin; Reynolds, Andy; Clarke, Laura; Flicek, Paul; Cunningham, Fiona; Herrero, Javier; Keenen, Stephen; Kulesha, Eugene; Leinonen, Rasko; McLaren, William M.; Radhakrishnan, Rajesh; Smith, Richard E.; Zalunin, Vadim; Zheng-Bradley, Xiangqun; Korbel, Jan O.; Stütz, Adrian M.; Humphray, Sean; Bauer, Markus; Cheetham, R. Keira; Cox, Tony; Eberle, Michael; James, Terena; Kahn, Scott; Murray, Lisa; Chakravarti, Aravinda; Ye, Kai; De La Vega, Francisco M.; Fu, Yutao; Hyland, Fiona C. L.; Manning, Jonathan M.; McLaughlin, Stephen F.; Peckham, Heather E.; Sakarya, Onur; Sun, Yongming A.; Tsung, Eric F.; Batzer, Mark A.; Konkel, Miriam K.; Walker, Jerilyn A.; Sudbrak, Ralf; Albrecht, Marcus W.; Amstislavskiy, Vyacheslav S.; Herwig, Ralf; Parkhomchuk, Dimitri V.; Sherry, Stephen T.; Agarwala, Richa; Khouri, Hoda M.; Morgulis, Aleksandr O.; Paschall, Justin E.; Phan, Lon D.; Rotmistrovsky, Kirill E.; Sanders, Robert D.; Shumway, Martin F.; Xiao, Chunlin; McVean, Gil A.; Auton, Adam; Iqbal, Zamin; Lunter, Gerton; Marchini, Jonathan L.; Moutsianas, Loukas; Myers, Simon; Tumian, Afidalina; Desany, Brian; Knight, James; Winer, Roger; Craig, David W.; Beckstrom-Sternberg, Steve M.; Christoforides, Alexis; Kurdoglu, Ahmet A.; Pearson, John V.; Sinari, Shripad A.; Tembe, Waibhav D.; Haussler, David; Hinrichs, Angie S.; Katzman, Sol J.; Kern, Andrew; Kuhn, Robert M.; Przeworski, Molly; Hernandez, Ryan D.; Howie, Bryan; Kelley, Joanna L.; Melton, S. Cord; Abecasis, Gonçalo R.; Li, Yun; Anderson, Paul; Blackwell, Tom; Chen, Wei; Cookson, William O.; Ding, Jun; Kang, Hyun Min; Lathrop, Mark; Liang, Liming; Moffatt, Miriam F.; Scheet, Paul; Sidore, Carlo; Snyder, Matthew; Zhan, Xiaowei; Zöllner, Sebastian; Awadalla, Philip; Casals, Ferran; Idaghdour, Youssef; Keebler, John; Stone, Eric A.; Zilversmit, Martine; Jorde, Lynn; Xing, Jinchuan; Eichler, Evan E.; Aksay, Gozde; Alkan, Can; Hajirasouliha, Iman; Hormozdiari, Fereydoun; Kidd, Jeffrey M.; Sahinalp, S. Cenk; Sudmant, Peter H.; Mardis, Elaine R.; Chen, Ken; Chinwalla, Asif; Ding, Li; Koboldt, Daniel C.; McLellan, Mike D.; Dooling, David; Weinstock, George; Wallis, John W.; Wendl, Michael C.; Zhang, Qunyuan; Durbin, Richard M.; Albers, Cornelis A.; Ayub, Qasim; Balasubramaniam, Senduran; Barrett, Jeffrey C.; Carter, David M.; Chen, Yuan; Conrad, Donald F.; Danecek, Petr; Dermitzakis, Emmanouil T.; Hu, Min; Huang, Ni; Hurles, Matt E.; Jin, Hanjun; Jostins, Luke; Keane, Thomas M.; Le, Si Quang; Lindsay, Sarah; Long, Quan; MacArthur, Daniel G.; Montgomery, Stephen B.; Parts, Leopold; Stalker, James; Tyler-Smith, Chris; Walter, Klaudia; Zhang, Yujun; Gerstein, Mark B.; Snyder, Michael; Abyzov, Alexej; Balasubramanian, Suganthi; Bjornson, Robert; Du, Jiang; Grubert, Fabian; Habegger, Lukas; Haraksingh, Rajini; Jee, Justin; Khurana, Ekta; Lam, Hugo Y. K.; Leng, Jing; Mu, Xinmeng Jasmine; Urban, Alexander E.; Zhang, Zhengdong; Li, Yingrui; Luo, Ruibang; Marth, Gabor T.; Garrison, Erik P.; Kural, Deniz; Quinlan, Aaron R.; Stewart, Chip; Stromberg, Michael P.; Ward, Alistair N.; Wu, Jiantao; Lee, Charles; Mills, Ryan E.; Shi, Xinghua; McCarroll, Steven A.; Banks, Eric; DePristo, Mark A.; Handsaker, Robert E.; Hartl, Chris; Korn, Joshua M.; Li, Heng; Nemesh, James C.; Sebat, Jonathan; Makarov, Vladimir; Ye, Kenny; Yoon, Seungtai C.; Degenhardt, Jeremiah; Kaganovich, Mark; Clarke, Laura; Smith, Richard E.; Zheng-Bradley, Xiangqun; Korbel, Jan O.; Humphray, Sean; Cheetham, R. Keira; Eberle, Michael; Kahn, Scott; Murray, Lisa; Ye, Kai; De La Vega, Francisco M.; Fu, Yutao; Peckham, Heather E.; Sun, Yongming A.; Batzer, Mark A.; Konkel, Miriam K.; Walker, Jerilyn A.; Xiao, Chunlin; Iqbal, Zamin; Desany, Brian; Blackwell, Tom; Snyder, Matthew; Xing, Jinchuan; Eichler, Evan E.; Aksay, Gozde; Alkan, Can; Hajirasouliha, Iman; Hormozdiari, Fereydoun; Kidd, Jeffrey M.; Chen, Ken; Chinwalla, Asif; Ding, Li; McLellan, Mike D.; Wallis, John W.; Hurles, Matt E.; Conrad, Donald F.; Walter, Klaudia; Zhang, Yujun; Gerstein, Mark B.; Snyder, Michael; Abyzov, Alexej; Du, Jiang; Grubert, Fabian; Haraksingh, Rajini; Jee, Justin; Khurana, Ekta; Lam, Hugo Y. K.; Leng, Jing; Mu, Xinmeng Jasmine; Urban, Alexander E.; Zhang, Zhengdong; Gibbs, Richard A.; Bainbridge, Matthew; Challis, Danny; Coafra, Cristian; Dinh, Huyen; Kovar, Christie; Lee, Sandy; Muzny, Donna; Nazareth, Lynne; Reid, Jeff; Sabo, Aniko; Yu, Fuli; Yu, Jin; Marth, Gabor T.; Garrison, Erik P.; Indap, Amit; Leong, Wen Fung; Quinlan, Aaron R.; Stewart, Chip; Ward, Alistair N.; Wu, Jiantao; Cibulskis, Kristian; Fennell, Tim J.; Gabriel, Stacey B.; Garimella, Kiran V.; Hartl, Chris; Shefler, Erica; Sougnez, Carrie L.; Wilkinson, Jane; Clark, Andrew G.; Gravel, Simon; Grubert, Fabian; Clarke, Laura; Flicek, Paul; Smith, Richard E.; Zheng-Bradley, Xiangqun; Sherry, Stephen T.; Khouri, Hoda M.; Paschall, Justin E.; Shumway, Martin F.; Xiao, Chunlin; McVean, Gil A.; Katzman, Sol J.; Abecasis, Gonçalo R.; Blackwell, Tom; Mardis, Elaine R.; Dooling, David; Fulton, Lucinda; Fulton, Robert; Koboldt, Daniel C.; Durbin, Richard M.; Balasubramaniam, Senduran; Coffey, Allison; Keane, Thomas M.; MacArthur, Daniel G.; Palotie, Aarno; Scott, Carol; Stalker, James; Tyler-Smith, Chris; Gerstein, Mark B.; Balasubramanian, Suganthi; Chakravarti, Aravinda; Knoppers, Bartha M.; Abecasis, Gonçalo R.; Bustamante, Carlos D.; Gharani, Neda; Gibbs, Richard A.; Jorde, Lynn; Kaye, Jane S.; Kent, Alastair; Li, Taosha; McGuire, Amy L.; McVean, Gil A.; Ossorio, Pilar N.; Rotimi, Charles N.; Su, Yeyang; Toji, Lorraine H.; TylerSmith, Chris; Brooks, Lisa D.; Felsenfeld, Adam L.; McEwen, Jean E.; Abdallah, Assya; Juenger, Christopher R.; Clemm, Nicholas C.; Collins, Francis S.; Duncanson, Audrey; Green, Eric D.; Guyer, Mark S.; Peterson, Jane L.; Schafer, Alan J.; Abecasis, Gonçalo R.; Altshuler, David L.; Auton, Adam; Brooks, Lisa D.; Durbin, Richard M.; Gibbs, Richard A.; Hurles, Matt E.; McVean, Gil A.

    2011-01-01

    High-throughput sequencing technology enables population-level surveys of human genomic variation. Here, we examine the joint allele frequency distributions across continental human populations and present an approach for combining complementary aspects of whole-genome, low-coverage data and targeted high-coverage data. We apply this approach to data generated by the pilot phase of the Thousand Genomes Project, including whole-genome 2–4× coverage data for 179 samples from HapMap European, Asian, and African panels as well as high-coverage target sequencing of the exons of 800 genes from 697 individuals in seven populations. We use the site frequency spectra obtained from these data to infer demographic parameters for an Out-of-Africa model for populations of African, European, and Asian descent and to predict, by a jackknife-based approach, the amount of genetic diversity that will be discovered as sample sizes are increased. We predict that the number of discovered nonsynonymous coding variants will reach 100,000 in each population after ∼1,000 sequenced chromosomes per population, whereas ∼2,500 chromosomes will be needed for the same number of synonymous variants. Beyond this point, the number of segregating sites in the European and Asian panel populations is expected to overcome that of the African panel because of faster recent population growth. Overall, we find that the majority of human genomic variable sites are rare and exhibit little sharing among diverged populations. Our results emphasize that replication of disease association for specific rare genetic variants across diverged populations must overcome both reduced statistical power because of rarity and higher population divergence. PMID:21730125

  15. Climatic conditions produce contrasting influences on demographic traits in a long-distance Arctic migrant.

    Science.gov (United States)

    Cleasby, Ian R; Bodey, Thomas W; Vigfusdottir, Freydis; McDonald, Jenni L; McElwaine, Graham; Mackie, Kerry; Colhoun, Kendrew; Bearhop, Stuart

    2017-03-01

    The manner in which patterns of variation and interactions among demographic rates contribute to population growth rate (λ) is key to understanding how animal populations will respond to changing climatic conditions. Migratory species are likely to be particularly sensitive to climatic conditions as they experience a range of different environments throughout their annual cycle. However, few studies have provided fully integrated demographic analyses of migratory populations in response to changing climatic conditions. Here, we employed integrated population models to demonstrate that the environmental conditions experienced during a short but critical period play a central role in the demography of a long-distance migrant, the light-bellied Brent goose (Branta bernicla hrota). Female survival was positively associated with June North Atlantic Oscillation (NAO) values, whereas male survival was not. In contrast, breeding productivity was negatively associated with June NAO, suggesting a trade-off between female survival and reproductive success. Both adult female and adult male survival showed low temporal variation, whereas there was high temporal variation in recruitment and breeding productivity. In addition, while annual population growth was positively correlated with annual breeding productivity, a sensitivity analysis revealed that population growth was most sensitive to changes in adult survival. Our results demonstrate that the environmental conditions experienced during a relatively short-time window at the start of the breeding season play a critical role in shaping the demography of a long-distant Arctic migrant. Crucially, different demographic rates responded in opposing directions to climatic variation, emphasising the need for integrated analysis of multiple demographic traits when understanding population dynamics. © 2016 The Authors. Journal of Animal Ecology © 2016 British Ecological Society.

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

    Science.gov (United States)

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

    2008-09-01

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

  17. 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.

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

    Science.gov (United States)

    Chiang, Yu-Chung; Huang, Bing-Hong; Liao, Pei-Chun

    2012-01-01

    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.

  19. 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...

  20. Demographic histories and patterns of linkage disequilibrium in Chinese and Indian rhesus macaques

    DEFF Research Database (Denmark)

    Hernandez, Ryan D; Hubisz, Melissa J; Wheeler, David A;

    2007-01-01

    To understand the demographic history of rhesus macaques (Macaca mulatta) and document the extent of linkage disequilibrium (LD) in the genome, we partially resequenced five Encyclopedia of DNA Elements regions in 9 Chinese and 38 captive-born Indian rhesus macaques. Population genetic analyses o...

  1. 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.

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

    DEFF Research Database (Denmark)

    Goldstein, Josephine

    2017-01-01

    Jellyfish blooms are conspicuous demographic events that have received increasing attention by the public and the scientific community over the last decades due to their negative impact on fisheries, tourism and other human industries. Several aspects of the complex life cycles of the jellyfish...... 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...... population dynamics and may inspire future research to sharpen an integrated view of jellyfish life histories in an ever changing environment. Such insight might be of particular importance beyond A. aurita in times of habitat eutrophication, climate warming and changes in species diversity....

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

    Science.gov (United States)

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

    2017-06-26

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

  4. Population expansions dominate demographic histories of endemic and widespread Pacific reef fishes

    Science.gov (United States)

    Delrieu-Trottin, Erwan; Mona, Stefano; Maynard, Jeffrey; Neglia, Valentina; Veuille, Michel; Planes, Serge

    2017-01-01

    Despite the unique nature of endemic species, their origin and population history remain poorly studied. We investigated the population history of 28 coral reef fish species, close related, from the Gambier and Marquesas Islands, from five families, with range size varying from widespread to small-range endemic. We analyzed both mitochondrial and nuclear sequence data using neutrality test and Bayesian analysis (EBSP and ABC). We found evidence for demographic expansions for most species (24 of 28), irrespective of range size, reproduction strategy or archipelago. The timing of the expansions varied greatly among species, from 8,000 to 2,000,000 years ago. The typical hypothesis for reef fish that links population expansions to the Last Glacial Maximum fit for 14 of the 24 demographic expansions. We propose two evolutionary processes that could lead to expansions older than the LGM: (a) we are retrieving the signature of an old colonization process for widespread, large-range endemic and paleoendemic species or (b) speciation; the expansion reflects the birth of the species for neoendemic species. We show for the first time that the demographic histories of endemic and widespread reef fish are not distinctly different and suggest that a number of processes drive endemism. PMID:28091580

  5. Population expansions dominate demographic histories of endemic and widespread Pacific reef fishes

    Science.gov (United States)

    Delrieu-Trottin, Erwan; Mona, Stefano; Maynard, Jeffrey; Neglia, Valentina; Veuille, Michel; Planes, Serge

    2017-01-01

    Despite the unique nature of endemic species, their origin and population history remain poorly studied. We investigated the population history of 28 coral reef fish species, close related, from the Gambier and Marquesas Islands, from five families, with range size varying from widespread to small-range endemic. We analyzed both mitochondrial and nuclear sequence data using neutrality test and Bayesian analysis (EBSP and ABC). We found evidence for demographic expansions for most species (24 of 28), irrespective of range size, reproduction strategy or archipelago. The timing of the expansions varied greatly among species, from 8,000 to 2,000,000 years ago. The typical hypothesis for reef fish that links population expansions to the Last Glacial Maximum fit for 14 of the 24 demographic expansions. We propose two evolutionary processes that could lead to expansions older than the LGM: (a) we are retrieving the signature of an old colonization process for widespread, large-range endemic and paleoendemic species or (b) speciation; the expansion reflects the birth of the species for neoendemic species. We show for the first time that the demographic histories of endemic and widespread reef fish are not distinctly different and suggest that a number of processes drive endemism.

  6. Inferring population structure and demographic history using Y-STR data from worldwide populations.

    Science.gov (United States)

    Xu, Hongyang; Wang, Chuan-Chao; Shrestha, Rukesh; Wang, Ling-Xiang; Zhang, Manfei; He, Yungang; Kidd, Judith R; Kidd, Kenneth K; Jin, Li; Li, Hui

    2015-02-01

    The Y chromosome is one of the best genetic materials to explore the evolutionary history of human populations. Global analyses of Y chromosomal short tandem repeats (STRs) data can reveal very interesting world population structures and histories. However, previous Y-STR works tended to focus on small geographical ranges or only included limited sample sizes. In this study, we have investigated population structure and demographic history using 17 Y chromosomal STRs data of 979 males from 44 worldwide populations. The largest genetic distances have been observed between pairs of African and non-African populations. American populations with the lowest genetic diversities also showed large genetic distances and coancestry coefficients with other populations, whereas Eurasian populations displayed close genetic affinities. African populations tend to have the oldest time to the most recent common ancestors (TMRCAs), the largest effective population sizes and the earliest expansion times, whereas the American, Siberian, Melanesian, and isolated Atayal populations have the most recent TMRCAs and expansion times, and the smallest effective population sizes. This clear geographic pattern is well consistent with serial founder model for the origin of populations outside Africa. The Y-STR dataset presented here provides the most detailed view of worldwide population structure and human male demographic history, and additionally will be of great benefit to future forensic applications and population genetic studies.

  7. 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.

  8. Demographics by depth: spatially explicit life-history dynamics of a protogynous reef fish

    OpenAIRE

    Collins, Angela B.; McBride, Richard S.

    2011-01-01

    Distribution and demographics of the hogfish (Lachnolaimus maximus) were investigated by using a combined approach of in situ observations and life history analyses. Presence, density, size, age, and size and age at sex change all varied with depth in the eastern Gulf of Mexico. Hogfish (64–774 mm fork length and 0–19 years old) were observed year-round and were most common over complex, natural hard bottom habitat. As depth increased, the presence and density of hogfish decreased, but mea...

  9. 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.

  10. Phylogeography and demographic history of two widespread Indo-Pacific mudskippers (Gobiidae: Periophthalmus).

    Science.gov (United States)

    Polgar, G; Zane, L; Babbucci, M; Barbisan, F; Patarnello, T; Rüber, L; Papetti, C

    2014-04-01

    This study provides a first description of the phylogeographic patterns and evolutionary history of two species of the mudskipper genus Periophthalmus. These amphibious gobies are distributed throughout the whole Indo-Pacific region and Atlantic coast of Africa, in peritidal habitats of soft-bottom coastal ecosystems. Three sequence datasets of two widely distributed species, Periophthalmus argentilineatus and P. kalolo, were obtained by amplifying and sequencing two mtDNA markers (D-loop and 16S rDNA) and the nDNA rag1 region. The three datasets were then used to perform phylogeographic, demographic and population genetic analyses. Our results indicate that tectonic events and past climatic oscillations strongly contributed to shape present genetic differentiation, phylogeographic and demographic patterns. We found support for the monophyly of P. kalolo, and only shallow genetic differentiation between East-African and Indo-Malayan populations of this species. However, our collections of the morphospecies P. argentilineatus include three molecularly distinct lineages, one of them more closely related to P. kalolo. The presence of Miocenic timings for the most recent common ancestors of some of these morphologically similar clades, suggests the presence of strong stabilising selection in mudskippers' habitats. At population level, demographic analyses and palaeoecological records of mangrove ecosystems suggest that Pleistocene bottlenecks and expansion plus secondary contact events of the studied species were associated with recurrent sea transgressions during interglacials, and sea regressions or stable regimes during glacials, respectively.

  11. Consequences of extreme life history traits on population persistence: do short-lived gobies face demographic bottlenecks?

    Science.gov (United States)

    Lefèvre, Carine D.; Nash, Kirsty L.; González-Cabello, Alonso; Bellwood, David R.

    2016-06-01

    The majority of coral reef goby species are short-lived, with some highly abundant species living less than 100 d. To understand the role and consequences of this extreme life history in shaping coral reef fish populations, we quantitatively documented the structure of small reef fish populations over a 26-month period (>14 short-lived fish generations) at an inshore reef on the Great Barrier Reef, Australia. Most species with life spans >1 yr, such as pomacentrids, exhibited a peak in recruitment during the austral summer, driving seasonal changes in the small fish community composition. In contrast, there were no clear changes in goby community composition, despite the abundance of short-lived, high turnover species. Species of Eviota, the most abundant gobiid genus observed, showed remarkably similar demographic profiles year-round, with consistent densities of adults as well as recently recruited juveniles. Our results demonstrate ongoing recruitment of these small cryptic fishes, which appears to compensate for an exceptionally short life span on the reef. Our results suggest that gobiid populations are able to overcome demographic limitations, and by maintaining reproduction, larval survival and recruitment throughout the year, they may avoid population bottlenecks. These findings also underline the potential trophodynamic importance of these small species; because of this constant turnover, Eviota species and other short-lived fishes may be particularly valuable contributors to the flow of energy on coral reefs, underpinning the year-round trophic structure.

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

    Directory of Open Access Journals (Sweden)

    Antonio González-Martín

    Full Text Available 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.

  13. 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. PMID:26292226

  14. 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.

  15. Reconstructing the demographic history of divergence between European river and brook lampreys using approximate Bayesian computations

    Directory of Open Access Journals (Sweden)

    Quentin Rougemont

    2016-04-01

    Full Text Available Inferring the history of isolation and gene flow during species divergence is a central question in evolutionary biology. The European river lamprey (Lampetra fluviatilis and brook lamprey (L. planeri show a low reproductive isolation but have highly distinct life histories, the former being parasitic-anadromous and the latter non-parasitic and freshwater resident. Here we used microsatellite data from six replicated population pairs to reconstruct their history of divergence using an approximate Bayesian computation framework combined with a random forest model. In most population pairs, scenarios of divergence with recent isolation were outcompeted by scenarios proposing ongoing gene flow, namely the Secondary Contact (SC and Isolation with Migration (IM models. The estimation of demographic parameters under the SC model indicated a time of secondary contact close to the time of speciation, explaining why SC and IM models could not be discriminated. In case of an ancient secondary contact, the historical signal of divergence is lost and neutral markers converge to the same equilibrium as under the less parameterized model allowing ongoing gene flow. Our results imply that models of secondary contacts should be systematically compared to models of divergence with gene flow; given the difficulty to discriminate among these models, we suggest that genome-wide data are needed to adequately reconstruct divergence history.

  16. 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

  17. 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

  18. 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

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

    DEFF Research Database (Denmark)

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

    2015-01-01

    Aim: We used an integrative approach to reconstruct the evolutionary history of the alpine long-eared bat, Plecotus macrobullaris, to test whether the variable effects of Pleistocene climatic oscillations across geographical regions led to contrasting population-level demographic histories within...... a single species. Location: The Western Palaearctic. Methods: We sequenced the complete mitochondrial genomes of 57 individuals from across the distribution of the species. The analysis integrated ecological niche modelling (ENM), approximate Bayesian computation (ABC), measures of genetic diversity...

  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. 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.

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

    Directory of Open Access Journals (Sweden)

    Tom H E Mason

    Full Text Available BACKGROUND: 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. METHODOLOGY/PRINCIPAL FINDINGS: 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. CONCLUSIONS/SIGNIFICANCE: 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

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

    Science.gov (United States)

    Yur'yev, Andriy; Akerele, Evaristo

    2016-11-01

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

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

    Directory of Open Access Journals (Sweden)

    David Piñera Ramírez

    2012-07-01

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

  5. Demographic structure and life history traits of the common goby Pomatoschistus microps (Teleostei, Gobiidae) in a Mediterranean coastal lagoon (Rhône River delta, France)

    Science.gov (United States)

    Pampoulie, Christophe

    2001-12-01

    Demographic structure and life history traits of the common goby Pomatoschistus microps were investigated in a brackish water lagoon of the Rhône River delta (Mediterranean Sea, southern France). The size frequency distribution and gonadosomatic index indicated that three different age groups occurred and reproduced successively in the lagoon, resulting in a long spawning period from March to September and a high investment in reproduction. This high investment in reproduction, which contrasts with that found in other mostly northern European populations, probably relates to the unpredictability of the goby's environmental conditions.

  6. Population structure and demographic history of the chukar partridge Alectoris chukar in China

    Institute of Scientific and Technical Information of China (English)

    Sen SONG; Shijie BAO; Ying WANG; Xinkang BAO; Bei AN; Xiaoli WANG; Naifa LIU

    2013-01-01

    Pleistocene climate fluctuations have shaped the patterns of genetic diversity observed in extant species.Although the effects of recent glacial cycles on genetic diversity have been well studied on species in Europe and North America,genetic legacy of species in the Pleistocene in north and northwest of China where glaciations was not synchronous with the ice sheet development in the Northern Hemisphere or or had little or no ice cover during the glaciations' period,remains poorly understood.Here we used phylogeographic methods to investigate the genetic structure and population history of the chukar partridge Alectoris chukar in north and northwest China.A 1,152-1,154 bp portion of the mtDNA CR were sequenced for all 279 specimens and a total number of 91 haplotypes were defined by 113 variable sites.High levels of gene flow were found and gene flow estimates were greater than 1 for most population pairs in our study.The AMOVA analysis showed that 81% and 16% of the total genetic variability was found within populations and among populations within groups,respectively.The demographic history of chukar was examined using neutrality tests and mismatch distribution analyses and results indicated Late Pleistocene population expansion.Results revealed that most populations of chukar experienced population expansion during 0.027-0.06 Ma.These results are at odds with the results found in Europe and North America,where population expansions occurred after Last Glacial Maximum (LGM,0.023 to 0.018 Ma).Our results are not consistent with the results from avian species of Tibetan Plateau,either,where species experienced population expansion following the retreat of the extensive glaciation period (0.5 to 0.175 Ma).

  7. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies.

    Science.gov (United States)

    Nyman, Tommi; Valtonen, Mia; Aspi, Jouni; Ruokonen, Minna; Kunnasranta, Mervi; Palo, Jukka U

    2014-09-01

    Island populations are on average smaller, genetically less diverse, and at a higher risk to go extinct than mainland populations. Low genetic diversity may elevate extinction probability, but the genetic component of the risk can be affected by the mode of diversity loss, which, in turn, is connected to the demographic history of the population. Here, we examined the history of genetic erosion in three Fennoscandian ringed seal subspecies, of which one inhabits the Baltic Sea 'mainland' and two the 'aquatic islands' composed of Lake Saimaa in Finland and Lake Ladoga in Russia. Both lakes were colonized by marine seals after their formation c. 9500 years ago, but Lake Ladoga is larger and more contiguous than Lake Saimaa. All three populations suffered dramatic declines during the 20th century, but the bottleneck was particularly severe in Lake Saimaa. Data from 17 microsatellite loci and mitochondrial control-region sequences show that Saimaa ringed seals have lost most of the genetic diversity present in their Baltic ancestors, while the Ladoga population has experienced only minor reductions. Using Approximate Bayesian computing analyses, we show that the genetic uniformity of the Saimaa subspecies derives from an extended founder event and subsequent slow erosion, rather than from the recent bottleneck. This suggests that the population has persisted for nearly 10,000 years despite having low genetic variation. The relatively high diversity of the Ladoga population appears to result from a high number of initial colonizers and a high post-colonization population size, but possibly also by a shorter isolation period and/or occasional gene flow from the Baltic Sea.

  8. 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

  9. LIFE-HISTORY VARIATION IN ECOLOGICALLY CONTRASTING POPULATIONS OF AGROSTIS-STOLONIFERA

    NARCIS (Netherlands)

    Kik, C.; van Andel, Jelte; Joenje, W.

    1990-01-01

    (1) Life-history variation among four ecologically contrasting populations of Agrostis stolonifera was examined using a reciprocal-transplant technique in natural habitats. (2) Survival, growth and flowering were mainly determined environmentally across transplant sites, although population effects

  10. Effect of Population Reduction on mtDNA Diversity and Demographic History of Korean Cattle Populations.

    Science.gov (United States)

    Dadi, Hailu; Lee, Seung-Hwan; Jung, Kyoung Sup; Choi, Jae Won; Ko, Moon-Suck; Han, Young-Joon; Kim, Jong-Joo; Kim, Kwan-Suk

    2012-09-01

    The population sizes of three Korean indigenous cattle populations have been drastically reduced over the past decades. In this study, we examined the extent to which reduction in populations influenced genetic diversity, population structure and demographic history using complete mitochondrial DNA (mtDNA) control region sequences. The complete mtDNA control region was sequenced in 56 individuals from Korean Black (KB), Jeju Black (JEB) and Korean Brindle (BRI) cattle populations. We included 27 mtDNA sequences of Korean Brown (BRO) from the GenBank database. Haplotype diversity estimate for the total population was high (0.870) while nucleotide diversity was low (0.004). The KB showed considerably low nucleotide (π = 0.001) and haplotype (h = 0.368) diversities. Analysis of molecular variance revealed a low level of genetic differentiation but this was highly significant (ppopulations. Of the total genetic diversity, 7.6% was attributable to among cattle populations diversity and the rest (92.4%) to differences within populations. The mismatch distribution analysis and neutrality tests revealed that KB population was in genetic equilibrium or decline. Indeed, unless an appropriate breeding management practice is developed, inbreeding and genetic drift will further impoverish genetic diversity of these cattle populations. Rational breed development and conservation strategy is needed to safeguard these cattle population.

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

    OpenAIRE

    2015-01-01

    Background Several factors have been reported as risk factors for multiple sclerosis (MS); however, the main causes of the disease are still unknown. A geographical area with a low MS incidence is Ahvaz, Iran. Objectives The objective of this study was to evaluate the association of several demographic characteristics, family history, and birth month with MS in Ahvaz. Patients and Methods ...

  12. 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

  13. 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

  14. 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

  15. Population genetics and demographic history of red seaweed, Palmaria palmata, from the Canada–northwest Atlantic

    Directory of Open Access Journals (Sweden)

    Jingjing Li

    2013-05-01

    Full Text Available The paleoclimate change (e.g. the glacial fluctuation in the late Pleistocene played an important role in shaping species’ population genetic structure, geographic distribution patterns, and gradient of diversity and composition. In this study, we sampled eight populations (138 individuals of Palmaria palmata, a commercially and ecologically important red macroalga found on both sides of the North Atlantic coast, aiming to assess the genetic structure and demographic history through the integration of mitochondrial cox2–3 spacer and RAPD variation. Eleven mtDNA cox2–3 haplotypes were detected, one of which (C3 was common and located centrally in a haplotype network. It is shared by all populations and is regarded as ancestral. Two northern populations from the Gulf of St. Lawrence had highest levels of genetic diversity, and were significantly divergent from all other populations. AMOVA showed that highest genetic variation for cox2–3 occurred within populations, while less existed among groups. This was consistent with the results of a STRUCTURE clustering analysis of RAPD data. Our genetic diversity and haplotype network analyses indicated that multiple glacial refugia might have existed for the species along the Canada–north- west Atlantic coast. Furthermore, Bayesian skyline plot analysis based on cox2–3 spacer sequences indicated that population size underwent a slight increase over temporal and spatial scales. This occurred in approximately 0.18–0.13 million years ago. Pairwise genetic distance (K2P between populations from the Gulf of St. Lawrence and the Bay of Fundy was 0.2%, indicating that they diverged from their common ancestor since about 0.36 million years ago. The evidence from our study suggests that climatic oscillations during the late Pleistocene had a drastic influence on the demography and genetic diversity of P. palmata in the Canada–northwest Atlantic.

  16. Demographic history of speciation in a Senecio altitudinal hybrid zone on Mt. Etna.

    Science.gov (United States)

    Filatov, Dmitry A; Osborne, Owen G; Papadopulos, Alexander S T

    2016-06-01

    Hybrid zones typically form as a result of species coming into secondary contact, but can also be established in situ as an ecotonal hybrid zone, a situation which has been reported far less frequently. An altitudinal hybrid zone on Mount Etna between two ragwort species (the low elevation Senecio chrysanthemifolius and high elevation S. aethnensis) could potentially represent either of these possibilities. However, a scenario of secondary contact vs. speciation with gene flow has not been explicitly tested. Here, we test these alternatives and demonstrate that the data do not support secondary contact. Furthermore, we report that the previous analyses of speciation history of these species were based on admixed populations, which has led to inflated estimates of ongoing, interspecific gene flow. Our new analyses, based on 'pure' S. aethnensis and S. chrysanthemifolius populations, reveal gene exchange of less than one effective migrant per generation, a level low enough to allow the species to accumulate neutral, genomewide differences. Overall, our results are consistent with a scenario of speciation with gene flow and a divergence time which coincides with the rise of Mt. Etna to altitudes above 2000 m (~150 KY). Further work to quantify the role of adaptation to contrasting environments of high and low altitudes will be needed to support the scenario of recent ecological speciation in this system.

  17. 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

    2012-07-01

    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.

  18. 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.

  19. Demographic characteristics of the Common Loon in the Upper Great Lakes: Old history and new findings

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — We provide several aspects of Common Loon life history that were previously undescribed. From 1989-98, information was collected from 1,165 uniquely marked loons...

  20. 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....

  1. The developmental history of the gadolinium chelates as intravenous contrast media for magnetic resonance.

    Science.gov (United States)

    Runge, Val M; Ai, Tao; Hao, Dapeng; Hu, Xuemei

    2011-12-01

    The developmental history of the gadolinium chelates, which spans 30 years, is described, focusing, in part, on the seminal work with each of the major agents in use today. By examining this history, insight is gained into important issues of efficacy and safety, with valuable lessons to be learned from the mistakes made during this period. An overview of physicochemical characteristics and chemical structures is also provided. The review concludes with a discussion of current research directions involving this field, which is that of the intravenous contrast media for magnetic resonance, in the past 5 years.

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

    Science.gov (United States)

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

    2016-12-01

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

  3. 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

  4. 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 ...... by random genetic drift. The implications for future gene mapping studies are discussed....

  5. 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 ...

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

    Science.gov (United States)

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

    2016-10-01

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

  7. 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.

  8. A coupled phylogeographical and species distribution modelling approach recovers the demographical history of a Neotropical seasonally dry forest tree species.

    Science.gov (United States)

    Collevatti, Rosane G; Terribile, Levi Carina; Lima-Ribeiro, Matheus S; Nabout, João C; de Oliveira, Guilherme; Rangel, Thiago F; Rabelo, Suelen G; Diniz-Filho, Jose A F

    2012-12-01

    We investigated here the demographical history of Tabebuia impetiginosa (Bignoniaceae) to understand the dynamics of the disjunct geographical distribution of South American seasonally dry forests (SDFs), based on coupling an ensemble approach encompassing hindcasting species distribution modelling and statistical phylogeographical analysis. We sampled 17 populations (280 individuals) in central Brazil and analysed the polymorphisms at chloroplast (trnS-trnG, psbA-trnH, and ycf6-trnC intergenic spacers) and nuclear (ITS nrDNA) genomes. Phylogenetic analyses based on median-joining network showed no haplotype sharing among population but strong evidence of incomplete lineage sorting. Coalescent analyses showed historical constant populations size, negligible gene flow among populations, and an ancient time to most recent common ancestor dated from ~4.7 ± 1.1 Myr BP. Most divergences dated from the Lower Pleistocene, and no signal of important population size reduction was found in coalescent tree and tests of demographical expansion. Demographical scenarios were built based on past geographical range dynamic models, using two a priori biogeographical hypotheses ('Pleistocene Arc' and 'Amazonian SDF expansion') and on two additional hypotheses suggested by the palaeodistribution modelling built with several algorithms for distribution modelling and palaeoclimatic data. The simulation of these demographical scenarios showed that the pattern of diversity found so far for T. impetiginosa is in consonance with a palaeodistribution expansion during the last glacial maximum (LGM, 21 kyr BP), strongly suggesting that the current disjunct distribution of T. impetiginosa in SDFs may represent a climatic relict of a once more wide distribution.

  9. Demographic and life history characteristics influence the cytonuclear composition of mosquitofish populations

    Science.gov (United States)

    Scribner, Kim T.; Avise, John C.; Beaumont, A.

    1994-01-01

    Experimental laboratory crosses and population experiments reveal significant differences in individual life-history traits and population demography between two related species of mosquitofish, Gambusia affinis and G. holbrooki. With respect to life-history traits, progeny from G. holbrooki exhibit larger size at birth and earlier age at sexual maturity than do progeny from G. affinis parents. With respect to demography, populations of G. holbrooki exhibit higher recruitment and carrying capacity and loser overwinter mortality than do populations of G. affinis. These differences help t explain the dramatic changes in cytonuclear genotype frequency observed in replicated experimental hybrid populations of Gambusia monitored over 52 weeks. These experimental results are interpreted in the context of introgression patterns previously studied indirectly from distributions of cytonuclear genotypes in a natural mosquitofish hybrid zone.

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

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    Bagheri

    2015-09-01

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

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

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    Etienne Patin

    2009-04-01

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

  12. Contrasting Socio-Economic and Demographic Profiles of Two, Small Island, Economic Species: MIRAB versus PROFIT/SITE

    Directory of Open Access Journals (Sweden)

    Ashley Oberst

    2007-11-01

    Full Text Available The MIRAB model developed by Bertram and Watters, based on remittances and aid, has dominated the small island economy literature for two decades. Recently, two challenges have surfaced: the PROFIT formulation emphasizing domestic policy flexibility - a so-called ‘resourcefulness of jurisdiction’ - and a dynamic private sector (Baldacchino, 2006; and the SITE model, stressing the role of tourism (McElroy, 2006. To date, there has been no comparative assessment of these different island models. This article addresses this gap. Its point of departure is to consider SITE islands as a subspecies of the PROFIT cluster. It constructs comprehensive profiles across 27 socio-economic and demographic variables for two island sub-groups with populations of less than three million: 23 MIRAB and 35 PROFIT-SITE. Results indicate PROFIT-SITE islands are much more affluent, socially advanced and demographically mature than their MIRAB counterparts.

  13. Inference of gorilla demographic and selective history from whole-genome sequence data.

    Science.gov (United States)

    McManus, Kimberly F; Kelley, Joanna L; Song, Shiya; Veeramah, Krishna R; Woerner, August E; Stevison, Laurie S; Ryder, Oliver A; Ape Genome Project, Great; Kidd, Jeffrey M; Wall, Jeffrey D; Bustamante, Carlos D; Hammer, Michael F

    2015-03-01

    Although population-level genomic sequence data have been gathered extensively for humans, similar data from our closest living relatives are just beginning to emerge. Examination of genomic variation within great apes offers many opportunities to increase our understanding of the forces that have differentially shaped the evolutionary history of hominid taxa. Here, we expand upon the work of the Great Ape Genome Project by analyzing medium to high coverage whole-genome sequences from 14 western lowland gorillas (Gorilla gorilla gorilla), 2 eastern lowland gorillas (G. beringei graueri), and a single Cross River individual (G. gorilla diehli). We infer that the ancestors of western and eastern lowland gorillas diverged from a common ancestor approximately 261 ka, and that the ancestors of the Cross River population diverged from the western lowland gorilla lineage approximately 68 ka. Using a diffusion approximation approach to model the genome-wide site frequency spectrum, we infer a history of western lowland gorillas that includes an ancestral population expansion of 1.4-fold around 970 ka and a recent 5.6-fold contraction in population size 23 ka. The latter may correspond to a major reduction in African equatorial forests around the Last Glacial Maximum. We also analyze patterns of variation among western lowland gorillas to identify several genomic regions with strong signatures of recent selective sweeps. We find that processes related to taste, pancreatic and saliva secretion, sodium ion transmembrane transport, and cardiac muscle function are overrepresented in genomic regions predicted to have experienced recent positive selection.

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

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    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.

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

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    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.

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

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2016-01-01

    The spatial distribution and the amount of intraspecific genetic variation of marine organisms are strongly influenced by many biotic and abiotic factors. Comparing biological and genetic data characterizing species living in the same habitat can help to elucidate the processes driving these variation patterns. Here, we present a comparative multispecies population genetic study on seven mangrove crabs co-occurring in the West Indian Ocean characterized by planktotrophic larvae with similar pelagic larval duration. Our main aim was to investigate whether a suite of biological, behavioural and ecological traits could affect genetic diversities of the study species in combination with historical demographic parameters. As possible current explanatory factors, we used the intertidal micro-habitat colonised by adult populations, various parameters of individual and population fecundity, and the timing of larval release. As the genetic marker, we used partial sequences of cytochrome oxidase subunit I gene. Genetic and ecological data were collected by the authors and/or gathered from primary literature. Permutational multiple regression models and ANOVA tests showed that species density and their reproductive output in combination with historical demographic parameters could explain the intraspecific genetic variation indexes across the seven species. In particular, species producing consistently less eggs per spawning event showed higher values of haplotype diversity. Moreover, Tajima’s D parameters well explained the recorded values for haplotype diversity and average γst. We concluded that current intraspecific gene diversities in crabs inhabiting mangrove forests were affected by population fecundity as well as past demographic history. The results were also discussed in terms of management and conservation of fauna in the Western Indian Ocean mangroves. PMID:27379532

  17. Population structure and demographic history of Sicyopterus japonicus (Perciformes; Gobiidae) in Taiwan inferred from mitochondrial control region sequences.

    Science.gov (United States)

    Ju, Y M; Hsu, C H; Fang, L S; Lin, H D; Wu, J H; Han, C C; Chen, I-S; Chiang, T Y

    2013-09-27

    The amphidromous goby Sicyopterus japonicus is distributed throughout southern Taiwan and Japan. Larvae of this freshwater fish go through a long marine stage. This migratory mode influences population genetic structure. We examined the genetic diversity, population differentiation, and demographic history of S. japonicus based on the mitochondrial DNA control region. We identified 102 haplotypes from 107 S. japonicus individuals from 22 populations collected from Taiwan and Islet Lanyu. High mean haplotype diversity (h = 0.999) versus low nucleotide diversity (θπ = 0.008) was detected across populations. There was low correspondence between clusters identified in the neighbor-joining tree and geographical region, as also indicated by AMOVA and pairwise F(ST) estimates. Both mismatch distribution analysis and Tajima's D test indicated that S. japonicus likely experienced a demographic expansion. Using a Bayesian skyline plot approach, we estimated the time of onset of the expansion of S. japonicus at 135 kyr (during the Pleistocene) and the time of stable effective population size at approximately 2.5 kyr (last glacial maximum). Based on these results, we suggest 1) a panmictic population at the oceanic planktonic larval stage, mediated by the Kuroshio current; 2) a long planktonic marine stage and long period of dispersal, which may have permitted efficient tracking of environmental shifts during the Pleistocene; and 3) a stable, constant population size ever since the last glacial maximum.

  18. Utilizing spatial demographic and life history variation to optimize sustainable yield of a temperate sex-changing fish.

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    Scott L Hamilton

    Full Text Available Fish populations vary geographically in demography and life history due to environmental and ecological processes and in response to exploitation. However, population dynamic models and stock assessments, used to manage fisheries, rarely explicitly incorporate spatial variation to inform management decisions. Here, we describe extensive geographic variation in several demographic and life history characteristics (e.g., size structure, growth, survivorship, maturation, and sex change of California sheephead (Semicossyphus pulcher, a temperate rocky reef fish targeted by recreational and commercial fisheries. Fish were sampled from nine locations throughout southern California in 2007-2008. We developed a dynamic size and age-structured model, parameterized separately for each location, to assess the potential cost or benefit in terms of fisheries yield and conservation objectives of changing minimum size limits and/or fishing mortality rates (compared to the status quo. Results indicate that managing populations individually, with location-specific regulations, could increase yield by over 26% while maintaining conservative levels of spawning biomass. While this local management approach would be challenging to implement in practice, we found statistically similar increases in yield could be achieved by dividing southern California into two separate management regions, reflecting geographic similarities in demography. To maximize yield, size limits should be increased by 90 mm in the northern region and held at current levels in the south. We also found that managing the fishery as one single stock (the status quo, but with a size limit 50 mm greater than the current regulations, could increase overall fishery yield by 15%. Increases in size limits are predicted to enhance fishery yield and may also have important ecological consequences for the predatory role of sheephead in kelp forests. This framework for incorporating demographic variation

  19. 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.

  20. 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.

  1. Phylogeography, genetic diversity and demographic history of the Iranian Kurdish groups based on mtDNA sequences

    Indian Academy of Sciences (India)

    FATAH ZAREI; HASSAN RAJABI-MAHAM

    2016-12-01

    Throughout the history of modern humans, the current Kurdish-inhabited area has served as part of a tricontinental crossroad for major human migrations. Also, a significant body of archaeological evidence points to this area as the site of Neolithic transition. To investigate the phylogeography, origins and demographic history, mtDNA D-loop region of individuals representing four Kurdish groups from Iran were analysed. Our data indicated that most of the Kurds mtDNA lineages belong to branches of the haplogroups with the Western Eurasian origin; with small fractions of the Eastern Eurasian and sub-Saharan African lineages. The low level of mtDNA diversity observed in the Havrami group presented a bias towards isolation or increased drift due to small population size; while in the Kurmanji group it indicated a bias towards drift or mass migration events during the 5–18th century AD. 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 data, revealed a recent expansion of the Kurds (∼9,500 years before present) related to the Neolithic transition from hunting and gathering, to farmingand cattle breeding in the Near East. Further, the high frequencies of typical haplogroups for early farmers (H; 37.1%) and hunter-gatherers (U; 13.8%) in the Kurds may testify the earlier hunter-gatherers in the Kurdish-inhabited area that adopted and admixed the Kurds ancestors following the Neolithic transition.

  2. Contrasting Responses to Harvesting and Environmental Drivers of Fast and Slow Life History Species.

    Science.gov (United States)

    Quetglas, Antoni; Rueda, Lucía; Alvarez-Berastegui, Diego; Guijarro, Beatriz; Massutí, Enric

    2016-01-01

    According to their main life history traits, organisms can be arranged in a continuum from fast (species with small body size, short lifespan and high fecundity) to slow (species with opposite characteristics). Life history determines the responses of organisms to natural and anthropogenic factors, as slow species are expected to be more sensitive than fast species to perturbations. Owing to their contrasting traits, cephalopods and elasmobranchs are typical examples of fast and slow strategies, respectively. We investigated the responses of these two contrasting strategies to fishing exploitation and environmental conditions (temperature, productivity and depth) using generalized additive models. Our results confirmed the foreseen contrasting responses of cephalopods and elasmobranchs to natural (environment) and anthropogenic (harvesting) influences. Even though a priori foreseen, we did expect neither the clear-cut differential responses between groups nor the homogeneous sensitivity to the same factors within the two taxonomic groups. Apart from depth, which affected both groups equally, cephalopods and elasmobranchs were exclusively affected by environmental conditions and fishing exploitation, respectively. Owing to its short, annual cycle, cephalopods do not have overlapping generations and consequently lack the buffering effects conferred by different age classes observed in multi-aged species such as elasmobranchs. We suggest that cephalopods are sensitive to short-term perturbations, such as seasonal environmental changes, because they lack this buffering effect but they are in turn not influenced by continuous, long-term moderate disturbances such as fishing because of its high population growth and turnover. The contrary would apply to elasmobranchs, whose multi-aged population structure would buffer the seasonal environmental effects, but they would display strong responses to uninterrupted harvesting due to its low population resilience. Besides

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

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    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.

  4. 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.

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

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    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.

  6. 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

  7. Divergence of gastropod life history in contrasting thermal environments in a geothermal lake.

    Science.gov (United States)

    Johansson, M P; Ermold, F; Kristjánsson, B K; Laurila, A

    2016-10-01

    Experiments using natural populations have provided mixed support for thermal adaptation models, probably because the conditions are often confounded with additional environmental factors like seasonality. The contrasting geothermal environments within Lake Mývatn, northern Iceland, provide a unique opportunity to evaluate thermal adaptation models using closely located natural populations. We conducted laboratory common garden and field reciprocal transplant experiments to investigate how thermal origin influences the life history of Radix balthica snails originating from stable cold (6 °C), stable warm (23 °C) thermal environments or from areas with seasonal temperature variation. Supporting thermal optimality models, warm-origin snails survived poorly at 6 °C in the common garden experiment and better than cold-origin and seasonal-origin snails in the warm habitat in the reciprocal transplant experiment. Contrary to thermal adaptation models, growth rate in both experiments was highest in the warm populations irrespective of temperature, indicating cogradient variation. The optimal temperatures for growth and reproduction were similar irrespective of origin, but cold-origin snails always had the lowest performance, and seasonal-origin snails often performed at an intermediate level compared to snails originating in either stable environment. Our results indicate that central life-history traits can differ in their mode of evolution, with survival following the predictions of thermal optimality models, whereas ecological constraints have shaped the evolution of growth rates in local populations.

  8. Oceanography and life history predict contrasting genetic population structure in two Antarctic fish species.

    Science.gov (United States)

    Young, Emma F; Belchier, Mark; Hauser, Lorenz; Horsburgh, Gavin J; Meredith, Michael P; Murphy, Eugene J; Pascoal, Sonia; Rock, Jennifer; Tysklind, Niklas; Carvalho, Gary R

    2015-06-01

    Understanding the key drivers of population connectivity in the marine environment is essential for the effective management of natural resources. Although several different approaches to evaluating connectivity have been used, they are rarely integrated quantitatively. Here, we use a 'seascape genetics' approach, by combining oceanographic modelling and microsatellite analyses, to understand the dominant influences on the population genetic structure of two Antarctic fishes with contrasting life histories, Champsocephalus gunnari and Notothenia rossii. The close accord between the model projections and empirical genetic structure demonstrated that passive dispersal during the planktonic early life stages is the dominant influence on patterns and extent of genetic structuring in both species. The shorter planktonic phase of C. gunnari restricts direct transport of larvae between distant populations, leading to stronger regional differentiation. By contrast, geographic distance did not affect differentiation in N. rossii, whose longer larval period promotes long-distance dispersal. Interannual variability in oceanographic flows strongly influenced the projected genetic structure, suggesting that shifts in circulation patterns due to climate change are likely to impact future genetic connectivity and opportunities for local adaptation, resilience and recovery from perturbations. Further development of realistic climate models is required to fully assess such potential impacts.

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

    Science.gov (United States)

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

    2013-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Evolutionary origin and demographic history of an ancient conifer (Juniperus microsperma) in the Qinghai-Tibetan Plateau.

    Science.gov (United States)

    Shang, Hui-Ying; Li, Zhong-Hu; Dong, Miao; Adams, Robert P; Miehe, Georg; Opgenoorth, Lars; Mao, Kang-Shan

    2015-05-15

    All Qinghai-Tibetan Plateau (QTP) endemic species are assumed to have originated recently, although very rare species most likely diverged early. These ancient species provide an excellent model to examine the origin and evolution of QTP endemic plants in response to the QTP uplifts and the climate changes that followed in this high altitude region. In this study, we examined these hypotheses by employing sequence variation from multiple nuclear and chloroplast DNA of 239 individuals of Juniperus microsperma and its five congeners. Both phylogenetic and population genetic analyses revealed that J. microsperma diverged from its sister clade comprising two species with long isolation around the Early Miocene, which corresponds to early QTP uplift. Demographic modeling and coalescent tests suggest that J. microsperma experienced an obvious bottleneck event during the Quaternary when the global climate greatly oscillated. The results presented here support the hypotheses that the QTP uplifts and Quaternary climate changes played important roles in shaping the evolutionary history of this rare juniper.

  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. Contrasting patterns of Y chromosome and mtDNA variation in Africa: evidence for sex-biased demographic processes.

    Science.gov (United States)

    Wood, Elizabeth T; Stover, Daryn A; Ehret, Christopher; Destro-Bisol, Giovanni; Spedini, Gabriella; McLeod, Howard; Louie, Leslie; Bamshad, Mike; Strassmann, Beverly I; Soodyall, Himla; Hammer, Michael F

    2005-07-01

    To investigate associations between genetic, linguistic, and geographic variation in Africa, we type 50 Y chromosome SNPs in 1122 individuals from 40 populations representing African geographic and linguistic diversity. We compare these patterns of variation with those that emerge from a similar analysis of published mtDNA HVS1 sequences from 1918 individuals from 39 African populations. For the Y chromosome, Mantel tests reveal a strong partial correlation between genetic and linguistic distances (r=0.33, P=0.001) and no correlation between genetic and geographic distances (r=-0.08, P>0.10). In contrast, mtDNA variation is weakly correlated with both language (r=0.16, P=0.046) and geography (r=0.17, P=0.035). AMOVA indicates that the amount of paternal among-group variation is much higher when populations are grouped by linguistics (Phi(CT)=0.21) than by geography (Phi(CT)=0.06). Levels of maternal genetic among-group variation are low for both linguistics and geography (Phi(CT)=0.03 and 0.04, respectively). When Bantu speakers are removed from these analyses, the correlation with linguistic variation disappears for the Y chromosome and strengthens for mtDNA. These data suggest that patterns of differentiation and gene flow in Africa have differed for men and women in the recent evolutionary past. We infer that sex-biased rates of admixture and/or language borrowing between expanding Bantu farmers and local hunter-gatherers played an important role in influencing patterns of genetic variation during the spread of African agriculture in the last 4000 years.

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

    Directory of Open Access Journals (Sweden)

    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

  15. 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.

  16. Reconstructing the demographic history of the human lineage using whole-genome sequences from human and three great apes.

    Science.gov (United States)

    Hara, Yuichiro; Imanishi, Tadashi; Satta, Yoko

    2012-01-01

    The demographic history of human would provide helpful information for identifying the evolutionary events that shaped the humanity but remains controversial even in the genomic era. To settle the controversies, we inferred the speciation times (T) and ancestral population sizes (N) in the lineage leading to human and great apes based on whole-genome alignment. A coalescence simulation determined the sizes of alignment blocks and intervals between them required to obtain recombination-free blocks with a high frequency. This simulation revealed that the size of the block strongly affects the parameter inference, indicating that recombination is an important factor for achieving optimum parameter inference. From the whole genome alignments (1.9 giga-bases) of human (H), chimpanzee (C), gorilla (G), and orangutan, 100-bp alignment blocks separated by ≥5-kb intervals were sampled and subjected to estimate τ = μT and θ = 4μgN using the Markov chain Monte Carlo method, where μ is the mutation rate and g is the generation time. Although the estimated τ(HC) differed across chromosomes, τ(HC) and τ(HCG) were strongly correlated across chromosomes, indicating that variation in τ is subject to variation in μ, rather than T, and thus, all chromosomes share a single speciation time. Subsequently, we estimated Ts of the human lineage from chimpanzee, gorilla, and orangutan to be 6.0-7.6, 7.6-9.7, and 15-19 Ma, respectively, assuming variable μ across lineages and chromosomes. These speciation times were consistent with the fossil records. We conclude that the speciation times in our recombination-free analysis would be conclusive and the speciation between human and chimpanzee was a single event.

  17. 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

  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. Family History, Diabetes, and Other Demographic and Risk Factors Among Participants of the National Health and Nutrition Examination Survey 1999–2002

    Directory of Open Access Journals (Sweden)

    Debra Duquette, MS, CGC

    2005-03-01

    Full Text Available Introduction Family history of diabetes has been recognized as an important risk factor of the disease. Family medical history represents valuable genomic information because it characterizes the combined interactions between environmental, behavioral, and genetic factors. This study examined the strength and effect of having a family history of diabetes on the prevalence of self-reported, previously diagnosed diabetes among adult participants of the National Health and Nutrition Examination Survey 1999–2002. Methods The study population included data from 10,283 participants aged 20 years and older. Gender, age, race/ethnicity, poverty income ratio, education level, body mass index, and family history of diabetes were examined in relation to diabetes status. Diabetes prevalence estimates and odds ratios of diabetes were calculated based on family history and other factors. Results The prevalence of diabetes among individuals who have a first-degree relative with diabetes (14.3% was significantly higher than that of individuals without a family history (3.2%, corresponding to a crude odds ratio of five. Both prevalence and odds ratio estimates significantly increased with the number of relatives affected with diabetes. Family history was also associated with several demographic and risk factors. Conclusion Family history of diabetes was shown to be a significant predictor of diabetes prevalence in the adult U.S. population. We advocate the inclusion of family history assessment in public health prevention and screening programs as an inexpensive and valuable source of genomic information and measure of diabetes risk.

  20. Mercury accumulation in peatbogs at Czech sites with contrasting pollution histories.

    Science.gov (United States)

    Zuna, M; Ettler, V; Šebek, O; Mihaljevič, M

    2012-05-01

    Mercury (Hg) concentrations and accumulation patterns were studied in (210)Pb-dated peat cores from three ombrotrophic sites in the Czech Republic with contrasting emission histories (Novodomské rašeliniště, ND, and Bílá Smědá, BS, in the polluted northern parts of the country, and Jezerní slať, JS, in a relatively pristine southern part of the Czech Republic). The Hg concentration varied significantly between sites. Whereas the sites in the northern part of the Czech Republic yielded a range of higher Hg concentrations (50-750 μg kg(-1) for ND and 30-600 μg kg(-1) for BS), a Hg concentration range of 40-220 μg kg(-1) was reported at JS. At the northern localities, the highest Hg concentrations were detected at depths of 5-10 cm, corresponding to the period between the early 1960s until the late 1980s. In contrast, the highest Hg values at JS were observed at a depth of 10-15 cm, corresponding to the period between the early 1950s and the early 1970s. The maximum Hg accumulation rates were approximately 2× higher at the northern localities (ND: 106 μg m(-2)yr(-1), BS: 90 μg m(-2)yr(-1), JS: 43 μg m(-2)yr(-1)). Although a decrease in the Hg concentration can be observed in the youngest segments of all the peat cores, a slight increase in Hg accumulation rates in the most recent peat segments (living Sphagnum moss) has been reported for all three sites (40-44 μg m(-2)yr(-1)), which is approximately 2× higher than in peat bogs in western and northern Europe. This observation may either be related to a real recent increase in Hg emissions in Central Europe (active coal mining and burning and limited Hg pollution control in thermal power plants) or could indicate a preferential Hg binding mechanism in the living moss at the surface of the peat.

  1. Deeper insight into maternal genetic assessments and demographic history for Egyptian indigenous chicken populations using mtDNA analysis

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    Marwa A. Eltanany

    2016-09-01

    Full Text Available This study principally sought to reveal the demographic expansion of Egyptian indigenous chickens (EIC using representative breeds: Sinai (North, Fayoumi (Middle and Dandarawi (South of Egypt as well as to deeply clarify their genetic diversity, possible matrilineal origin and dispersal routes. A total of 33 partial mitochondrial DNA sequences were generated from EIC and compared with a worldwide reference dataset of 1290 wild and domestic chicken sequences. Study populations had 12 polymorphic variable sites and 7 haplotypes. A lack of maternal substructure between EIC was detected (FST = 0.003. The unimodal mismatch distribution and negative values of Tajima’s D (−0.659 and Fu’s Fs (−0.157 indicated demographic expansion among EIC and pointed to Fayoumi as the oldest EIC population. Egyptian haplotypes were clustered phylogenetically into two divergent clades. Their phylogeography revealed an ancient single maternal lineage of Egyptian chickens likely derived from Indian-Subcontinent. Moreover, a recent maternal commercial heritage possibly originated in Yunnan-Province and/or surrounding areas was admixed restrictedly into Sinai. It is implied that Egypt was an entry point for Indian chicken into Africa and its further dispersal route to Europe. This study provides a clue supporting the previous assumption that urged utilizing consistent founder populations having closely related progenitors for synthetizing a stabilized homogenous crossbreed as a sustainable discipline in breeding program.

  2. Patterns of nucleotide sequence variation in ICAM1 and TNF genes in twelve ethnic groups of India: roles of demographic history and natural selection

    Indian Academy of Sciences (India)

    Sanghamitra Sengupta; Shabana Farheen; Neelanjana Mukherjee; Partha P. Majumder

    2007-12-01

    We have studied DNA sequence variation in and around the genes ICAM1 and TNF, which play functional and correlated roles in inflammatory processes and immune cell responses, in 12 diverse ethnic groups of India, with a view to investigating the relative roles of demographic history and natural selection in shaping the observed patterns of variation. The total numbers of single nucleotide polymorphisms (SNPs) detected at the ICAM1 and TNF loci were 29 and 12, respectively. Haplotype and allele frequencies differed significantly across populations. The site frequency spectra at these loci were significantly different from those expected under neutrality, and showed an excess of intermediate-frequency variants consistent with balancing selection. However, as expected under balancing selection, there was no significant reduction of $F_{ST}$ values compared to neutral autosomal loci. Mismatch distributions were consistent with population expansion for both loci. On the other hand, the phylogenetic network among haplotypes for the TNF locus was similar to expectations under population expansion, while that for the ICAM1 was as expected under balancing selection. Nucleotide diversity at the ICAM1 locus was an order of magnitude lower in the promoter region, compared to the introns or exons, but no such difference was noted for the TNF gene. Thus, we conclude that the pattern of nucleotide variation in these genes has been modulated by both demographic history and selection. This is not surprising in view of the known allelic associations of several polymorphisms in these genes with various diseases, both infectious and noninfectious.

  3. Numts help to reconstruct the demographic history of the ocellated lizard (Lacerta lepida) in a secondary contact zone

    DEFF Research Database (Denmark)

    Miraldo, Andreia; Hewitt, Godfrey M; Dear, Paul H

    2012-01-01

    In northwestern Iberia, two largely allopatric Lacerta lepida mitochondrial lineages occur, L5 occurring to the south of Douro River and L3 to the north, with a zone of putative secondary contact in the region of the Douro River valley. Cytochrome b sequence chromatograms with polymorphisms...... of secondary contact between the lineages. The additional incidence of these numts to the north of the putative contact zone is consistent with an earlier postglacial northward range expansion of L5, preceding that of L3. We show that genetic exchange between the lineages responsible for the origin...... of these numts in L3 after secondary contact occurred prior to, or coincident with, the northward expansion of L3. This study shows that, in the context of phylogeographic analysis, numts can provide evidence for past demographic events and can be useful tools for the reconstruction of complex evolutionary...

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

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    Mohammad Reza Ashrafzadeh

    2015-12-01

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

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

    Science.gov (United States)

    Woods, Steven R; Archer, Steven R; Schwinning, Susan

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Steven R Woods

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

  7. Pragmatic perspective on conservation genetics and demographic history of the last surviving population of Kashmir red deer (Cervus elaphus hanglu) in India.

    Science.gov (United States)

    Mukesh; Kumar, Ved P; Sharma, Lalit K; Shukla, Malay; Sathyakumar, Sambandam

    2015-01-01

    The hangul (Cervus elaphus hanglu) is of great conservation concern because it represents the easternmost and only hope for an Asiatic survivor of the red deer species in the Indian subcontinent. Despite the rigorous conservation efforts of the Department of Wildlife Protection in Jammu & Kashmir, the hangul population has experienced a severe decline in numbers and range contraction in the past few decades. The hangul population once abundant in the past has largely become confined to the Dachigam landscape, with a recent population estimate of 218 individuals. We investigated the genetic variability and demographic history of the hangul population and found that it has shown a relatively low diversity estimates when compared to other red deer populations of the world. Neutrality tests, which are used to evaluate demographic effects, did not support population expansion, and the multimodal pattern of mismatch distribution indicated that the hangul population is under demographic equilibrium. Furthermore, the hangul population did not exhibit any signature of bottleneck footprints in the past, and Coalescent Bayesian Skyline plot analysis revealed that the population had not experienced any dramatic changes in the effective population size over the last several thousand years. We observed a strong evidence of sub-structuring in the population, wherein the majority of individuals were assigned to different clusters in Bayesian cluster analysis. Population viability analysis demonstrated insignificant changes in the mean population size, with a positive growth rate projected for the next hundred years. We discuss the phylogenetic status of hangul for the first time among the other red deer subspecies of the world and strongly recommend to upgrade hangul conservation status under IUCN that should be discrete from the other red deer subspecies of the world to draw more conservation attention from national and international bodies.

  8. 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.

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

    Science.gov (United States)

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

    2016-11-01

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

  10. Pragmatic perspective on conservation genetics and demographic history of the last surviving population of Kashmir red deer (Cervus elaphus hanglu in India.

    Directory of Open Access Journals (Sweden)

    Mukesh

    Full Text Available The hangul (Cervus elaphus hanglu is of great conservation concern because it represents the easternmost and only hope for an Asiatic survivor of the red deer species in the Indian subcontinent. Despite the rigorous conservation efforts of the Department of Wildlife Protection in Jammu & Kashmir, the hangul population has experienced a severe decline in numbers and range contraction in the past few decades. The hangul population once abundant in the past has largely become confined to the Dachigam landscape, with a recent population estimate of 218 individuals. We investigated the genetic variability and demographic history of the hangul population and found that it has shown a relatively low diversity estimates when compared to other red deer populations of the world. Neutrality tests, which are used to evaluate demographic effects, did not support population expansion, and the multimodal pattern of mismatch distribution indicated that the hangul population is under demographic equilibrium. Furthermore, the hangul population did not exhibit any signature of bottleneck footprints in the past, and Coalescent Bayesian Skyline plot analysis revealed that the population had not experienced any dramatic changes in the effective population size over the last several thousand years. We observed a strong evidence of sub-structuring in the population, wherein the majority of individuals were assigned to different clusters in Bayesian cluster analysis. Population viability analysis demonstrated insignificant changes in the mean population size, with a positive growth rate projected for the next hundred years. We discuss the phylogenetic status of hangul for the first time among the other red deer subspecies of the world and strongly recommend to upgrade hangul conservation status under IUCN that should be discrete from the other red deer subspecies of the world to draw more conservation attention from national and international bodies.

  11. Contrasting maternal and paternal histories in the linguistic context of Burkina Faso.

    Science.gov (United States)

    Barbieri, Chiara; Whitten, Mark; Beyer, Klaus; Schreiber, Henning; Li, Mingkun; Pakendorf, Brigitte

    2012-04-01

    Burkina Faso is located in the heart of West Africa and is a representative of the local structured patterns of human variability. Here, different cultures and languages are found in a geographic contiguity, as a result of several waves of migration and the succession of long- and short-term empires. However, historical documentation for this area is only partial, focusing predominantly on the recent empires, and linguistic surveys lack the power to fully elucidate the social context of the contact-induced changes. In this paper, we report Y-chromosomal data and complete mtDNA genome sequences for ten populations from Burkina Faso whose languages belong to two very distantly related branches of the Niger-Congo phylum, the Gur and Mande language families. In addition, two further populations, the Mande-speaking Mandenka from Senegal and the Yoruba from Nigeria, were included for regional comparison. We focus on the different historical trajectories undergone by the maternal and paternal lineages. Our results reveal a striking structure in the paternal line, which matches the linguistic affiliation of the ethnolinguistic groups, in contrast to the near-complete homogeneity of the populations in the maternal line. However, while the ancient structure along the linguistic lines is apparent in the Y-chromosomal haplogroup affiliation, this has clearly been overlain by more recent migrations, as shown by significant correlations between the genetic distances based on Y chromosome short tandem repeats and geographic distances between the populations, as well as by the patterns of shared haplotypes. Using the complete mtDNA sequences, we are able to reconstruct population size variation in the past, showing a strong sign of expansion in the concomitance with the Holocene Climate Optimum approximately 12,000-10,000 years ago, which has been suggested as the cause of the spread of the Niger-Congo phylum in the area. However, subsequent climatic fluctuations do not appear to

  12. 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.

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

    Science.gov (United States)

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

    2014-02-22

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

  14. 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.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Science.gov (United States)

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

    2013-01-01

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

  17. Population Structure, Genetic Diversity, Effective Population Size, Demographic History and Regional Connectivity Patterns of the Endangered Dusky Grouper, Epinephelus marginatus (Teleostei: Serranidae), within Malta's Fisheries Management Zone.

    Science.gov (United States)

    Buchholz-Sørensen, Molly; Vella, Adriana

    2016-01-01

    The objective of this study is to describe the genetic population structure and demographic history of the endangered marine fish, Epinephelus marginatus, within Malta's Fisheries Management Zone for the purpose of localised conservation planning. Epinephelus marginatus is a long-lived, sedentary, reef-associated protogynous hermaphrodite with high commercial and recreational value that is at risk of extinction throughout its global distribution. Based on global trends, population substructuring and gaps in local knowledge this has led to an increased interest in evaluation of local stock. Assessment of Maltese demography was based on historical and contemporary catch landings data whilst genetic population structure and regional connectivity patterns were evaluated by examining 175 individuals collected within the central Mediterranean region between 2002 and 2009 using 14 nuclear microsatellite loci. Demographic stock assessment of Maltese E. marginatus' revealed a 99% decline in catch landings between 1947 and 2009 within the Fisheries Management Zone. A contemporary modest mean size was observed, 3 ± 3 kg, where approximately 17% of the population was juvenile, 68% female/sex-changing and 15% were male with a male-to-female sex ratio of 1:5. Genetic analysis describes the overall population of E. marginatus' within the Fisheries Management Zone as decreasing in size (ƟH = 2.2), which has gone through a significant size reduction in the past (M = 0.41) and consequently shows signs of moderate inbreeding (FIS = 0.10, p < 0.001) with an estimated effective population size of 130 individuals. Results of spatially explicit Bayesian genetic cluster analysis detected two geographically distinct subpopulations within Malta's Fisheries Management Zone and that they are connected to a larger network of E. marginatus' within the Sicily Channel. Results suggest conservation management should be designed to reflect E. marginatus' within Malta's Fisheries Management Zone

  18. Population Structure, Genetic Diversity, Effective Population Size, Demographic History and Regional Connectivity Patterns of the Endangered Dusky Grouper, Epinephelus marginatus (Teleostei: Serranidae, within Malta's Fisheries Management Zone.

    Directory of Open Access Journals (Sweden)

    Molly Buchholz-Sørensen

    Full Text Available The objective of this study is to describe the genetic population structure and demographic history of the endangered marine fish, Epinephelus marginatus, within Malta's Fisheries Management Zone for the purpose of localised conservation planning. Epinephelus marginatus is a long-lived, sedentary, reef-associated protogynous hermaphrodite with high commercial and recreational value that is at risk of extinction throughout its global distribution. Based on global trends, population substructuring and gaps in local knowledge this has led to an increased interest in evaluation of local stock. Assessment of Maltese demography was based on historical and contemporary catch landings data whilst genetic population structure and regional connectivity patterns were evaluated by examining 175 individuals collected within the central Mediterranean region between 2002 and 2009 using 14 nuclear microsatellite loci. Demographic stock assessment of Maltese E. marginatus' revealed a 99% decline in catch landings between 1947 and 2009 within the Fisheries Management Zone. A contemporary modest mean size was observed, 3 ± 3 kg, where approximately 17% of the population was juvenile, 68% female/sex-changing and 15% were male with a male-to-female sex ratio of 1:5. Genetic analysis describes the overall population of E. marginatus' within the Fisheries Management Zone as decreasing in size (ƟH = 2.2, which has gone through a significant size reduction in the past (M = 0.41 and consequently shows signs of moderate inbreeding (FIS = 0.10, p < 0.001 with an estimated effective population size of 130 individuals. Results of spatially explicit Bayesian genetic cluster analysis detected two geographically distinct subpopulations within Malta's Fisheries Management Zone and that they are connected to a larger network of E. marginatus' within the Sicily Channel. Results suggest conservation management should be designed to reflect E. marginatus' within Malta's Fisheries

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

    Science.gov (United States)

    Jørgensen, K T; Pedersen, B V; Nielsen, N M; Hansen, A V; Jacobsen, S; Frisch, M

    2011-10-01

    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. We linked national register data about socio-demographic variables, reproductive histories and OA hospital contacts to a cohort of 4.6 million Danes. Ratios of first OA hospitalisation rates (RRs) were calculated using Poisson regression. Overall, 100,437 women and 92,020 men had a first OA hospital contact during 91.5 million person-years between 1982 and 2008. Short education, low income and married status were significantly associated with increased OA risk, and persons with children were at higher risk of OA(overall) (RR=1.10 in women; RR=1.22 in men), OA(knee) (RRs 1.14; 1.28), OA(back) (RRs 1.18; 1.33), and OA(hand) (RRs 1.21; 1.43), but not of OA(hip) (RRs 0.96; 1.00) than persons without children. The RR of OA(overall) increased by a factor of 1.05 in women and 1.04 in men per additional child, most notably for OA(knee) in women (1.10 per child). Risk of OA hospitalisation was highest among married persons and persons with short education or low income. The similar or even stronger associations with reproductive factors in men than women suggest that unmeasured lifestyle factors rather than biological factors associated with pregnancy might explain the higher OA risk in persons with children. However, the particularly strong association between parity and risk of OA(knee) in women is compatible with a role of pregnancy-associated factors. Copyright © 2011 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights reserved.

  20. Contrasting Holocene environmental histories may explain patterns of species richness and rarity in a Central European landscape

    Science.gov (United States)

    Hájek, Michal; Dudová, Lydie; Hájková, Petra; Roleček, Jan; Moutelíková, Jitka; Jamrichová, Eva; Horsák, Michal

    2016-02-01

    Neolithic. This environmental history was unfavourable for the survival of Early-Holocene forest-steppe species in the north-eastern White Carpathians and may explain the impoverished grassland flora compared to the south-western part. We conclude that contrasting Holocene histories may explain those patterns in species richness and distributions, which cannot be explained by recent environmental conditions alone.

  1. Sequence diversity patterns suggesting balancing selection in partially sex-linked genes of the plant Silene latifolia are not generated by demographic history or gene flow.

    Science.gov (United States)

    Guirao-Rico, Sara; Sánchez-Gracia, Alejandro; Charlesworth, Deborah

    2017-03-01

    DNA sequence diversity in genes in the partially sex-linked pseudoautosomal region (PAR) of the sex chromosomes of the plant Silene latifolia is higher than expected from within-species diversity of other genes. This could be the footprint of sexually antagonistic (SA) alleles that are maintained by balancing selection in a PAR gene (or genes) and affect polymorphism in linked genome regions. SA selection is predicted to occur during sex chromosome evolution, but it is important to test whether the unexpectedly high sequence polymorphism could be explained without it, purely by the combined effects of partial linkage with the sex-determining region and the population's demographic history, including possible introgression from Silene dioica. To test this, we applied approximate Bayesian computation-based model choice to autosomal sequence diversity data, to find the most plausible scenario for the recent history of S. latifolia and then to estimate the posterior density of the most relevant parameters. We then used these densities to simulate variation to be expected at PAR genes. We conclude that an excess of variants at high frequencies at PAR genes should arise in S. latifolia populations only for genes with strong associations with fully sex-linked genes, which requires closer linkage with the fully sex-linked region than that estimated for the PAR genes where apparent deviations from neutrality were observed. These results support the need to invoke selection to explain the S. latifolia PAR gene diversity, and encourage further work to test the possibility of balancing selection due to sexual antagonism. © 2016 John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    Conn Jan E

    2009-11-01

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

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

    Science.gov (United States)

    Gutiérrez, Lina A; Naranjo, Nelson J; Cienfuegos, Astrid V; Muskus, Carlos E; Luckhart, Shirley; Conn, Jan E; Correa, Margarita M

    2009-11-19

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

  4. Historie

    DEFF Research Database (Denmark)

    Poulsen, Jens Aage

    Historie i serien handler om læreplaner og læremidler og deres brug i skolefaget historie. Bogen indeholder nyttige redskaber til at analysere og vurdere læremidler......Historie i serien handler om læreplaner og læremidler og deres brug i skolefaget historie. Bogen indeholder nyttige redskaber til at analysere og vurdere læremidler...

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

    Directory of Open Access Journals (Sweden)

    Carlos Jiménez

    Full Text Available Kidney transplantation is the therapy of choice for end-stage kidney disease. Graft's life span is shorter than expected due in part to the delayed diagnosis of various complications, specifically those related to silent progression. It is recognized that serum creatinine levels and proteinuria are poor markers of mild kidney lesions, which results in delayed clinical information. There are many investigation looking for early markers of graft damage. Decreasing kidney graft cortical microcirculation has been related to poor prognosis in kidney transplantation. Cortical capillary blood flow (CCBF can be measured by real-time contrast-enhanced sonography (RT-CES. Our aim was to describe the natural history of CCBF over time under diverse conditions of kidney transplantation, to explore the influence of donor conditions and recipient events, and to determine the capacity of CCBF for predicting renal function in medium term.RT-CES was performed in 79 consecutive kidney transplant recipients during the first year under regular clinical practice. Cortical capillary blood flow was measured. Clinical variables were analyzed. The influence of CCBF has been determined by univariate and multivariate analysis using mixed regression models based on sequential measurements for each patient over time. We used a first-order autoregression model as the structure of the covariation between measures. The post-hoc comparisons were considered using the Bonferroni correction.The CCBF values varied significantly over the study periods and were significantly lower at 48 h and day 7. Brain-death donor age and CCBF levels showed an inverse relationship (r: -0.62, p<0.001. Living donors showed higher mean CCBF levels than brain-death donors at each point in the study. These significant differences persisted at month 12 (54.5 ± 28.2 vs 33.7 ± 30 dB/sec, living vs brain-death donor, respectively, p = 0.004 despite similar serum creatinine levels (1.5 ± 0.3 and 1.5 ± 0

  6. 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

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

    Science.gov (United States)

    Kellner, Ronny; Hanschke, Christian; Begerow, Dominik

    2014-01-01

    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.

  8. 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.

  9. Low Contraceptive Use among Young Females in Uganda: Does Birth History and Age at Birth have an Influence? Analysis of 2011 Demographic and Health Survey

    Science.gov (United States)

    Kabagenyi, Allen; Habaasa, Gilbert; Rutaremwa, Gideon

    2017-01-01

    Background Globally adolescent fertility has been associated with increased risk to maternal and child health morbidity and mortality. The low use of contraception has been associated with high fertility levels, which is remains a public health concern that efforts have been raised to avert this. We examine the influence history of a previous birth and age at first birth would have on young women’s use of contraception. Methods Using the 2011 Uganda Demographic and Health Survey data, we examine the predictors of contraceptive use on a sample of 3692 young females in Uganda. While controlling for education and age of respondents, logistic regression analyses were run to provide the net effect of the examined predictors on contraceptive use. The study variables included age of respondents, marital status, age at first birth, births in past five years, socioeconomic status, residence, region, education level, religion, occupation and whether the last child was wanted. Results The findings show that only 12% of the adolescents were using contraception at the time of the survey. The key predictors of contraceptive use among young women in Uganda were age at first birth, history of previous birth, current age, and place of residence, education and socioeconomic status. Respondents who had a birth in the 5 years prior to the survey had five times (OR = 5.0, 95% CI = 3.7-6.5) the odds of contraceptive use compared to those who had never had a birth. Further, adolescent females with at least a secondary education were more likely to use contraceptives (OR = 1.55, 95% CI = 1.2-2.0) than those with primary education. The odds of contraceptive use were least among adolescents from Northern region (OR = 0.39, 95% CI = 0.2-0.6) compared to those from central region of Uganda. Muslim adolescent females were more likely to use contraceptives compared to Catholics (OR = 1.59, 95% CI = 1.1-2.3). Conclusion There is great need to address issues that hinder young people from using

  10. 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.

  11. 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....

  12. 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....

  13. 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.

  14. 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 Lan

  15. Can soil seed banks serve as genetic memory? A study of three species with contrasting life history strategies.

    Directory of Open Access Journals (Sweden)

    Bohumil Mandák

    Full Text Available We attempted to confirm that seed banks can be viewed as an important genetic reservoir by testing the hypothesis that standing (aboveground plants represent a nonrandom sample of the seed bank. We sampled multilocus allozyme genotypes from three species with different life history strategies: Amaranthus retroflexus, Carduus acanthoides, Pastinaca sativa. In four populations of each species we analysed the extent to which allele and genotype frequencies vary in consecutive life history stages including the summer seed bank, which has been overlooked up to now. We compared the winter seed bank (i.e., seeds collected before the spring germination peak, seedlings, rosettes, the summer seed bank (i.e., seeds collected after the spring germination peak and fruiting plants. We found that: (1 All three species partitioned most of their genetic diversity within life history stages and less among stages within populations and among populations. (2 All genetic diversity parameters, except for allele frequencies, were similar among all life history stages across all populations in different species. (3 There were differences in allele frequencies among life history stages at all localities in Amaranthus retroflexus and at three localities in both Carduus acanthoides and Pastinaca sativa. (4 Allele frequencies did not differ between the winter and summer seed bank in most Carduus acanthoides and Pastinaca sativa populations, but there was a marked difference in Amaranthus retroflexus. In conclusion, we have shown that the summer seed bank is not genetically depleted by spring germination and that a majority of genetic diversity remains in the soil through summer. We suggest that seed banks in the species investigated play an important role by maintaining genetic diversity sufficient for recovery rather than by accumulating new genetic diversity at each locality.

  16. Concordance and Contrast Between Community-Based Physicians' and Dentist Anesthesiologists' History and Physicals in Outpatient Pediatric Dental Surgery

    Science.gov (United States)

    Thikkurissy, Sarat; Smiley, Megann; Casamassimo, Paul S

    2008-01-01

    The objectives of this study were to compare history and physical examinations (H&Ps) done by community-based physicians and dentist anesthesiologists for children undergoing general anesthesia for dental rehabilitation. One hundred sixty-eight records were evaluated from the Nationwide Children's Hospital Dental Surgery Center of patients anesthetized between June 2006 and March 2007. These patients had H&Ps completed by both a community-based physician and a dentist anesthesiologist prior to general anesthesia. H&P forms were reviewed by the 3 authors to identify missing data, American Society of Anesthesiologists (ASA) classification, and impact on care. There was a statistically significant difference with respect to 10 of 17 sections examined, with the community-based physicians' H&Ps tending to be incomplete more often. Over 20% of community-based physicians made no mention of the history of present illness. One third of all physician H&Ps were missing vital sign recordings. No significant difference was noted between the physicians' and dentist anesthesiologists' ratings of ASA status. The physician H&P altered course of anesthesia treatment in <1% of studied cases. Statistically significant deficiencies were noted in the physician H&P in 60% of categories. PMID:18547151

  17. Contrasting Structures and Deformational History of Syntectonic Granites of Campina Grande and Serra Redonda, Borborema Province, NE Brazil

    Directory of Open Access Journals (Sweden)

    Sérgio Wilians de Oliveira Rodrigues

    2011-04-01

    Full Text Available The Campina Grande and Serra Redonda Granites are intrusive along the contact of the Paleoproterozoic basement(Alto Moxotó Domain with the Tonian gneisses (Alto Pajeú Domain of the Borborema Province (northeast Brazil. TheCampina Grande Granite (U-Pb age = 581± 2 Ma shows a concentric oval-shaped structure whereas the Serra RedondaGranite (U-Pb age = 576 ± 3 Ma has a tabular shape, elongated in the NE-SW direction. The plutons are separated bythe left-lateral Galante transcurrent shear zone. In this study, the anisotropy of magnetic susceptibility (AMS was appliedto 64 outcrops of granites to determine the internal structures of these plutons and to explore the relationship betweenmagmatism and deformation in an orogenic setting. The magnetic fabrics are concordant with the metamorphic structure ofthe host rocks. Strike-slip shear zones controlled the emplacement of the Serra Redonda Granite, as indicated by sigmoidalfoliation, defining shear bands associated with the Galante shear zone. In contrast, the magmatic/magnetic fabric of theCampina Grande granite seems to have been produced by body (ascensional forces. The pluton displays an inward dipping, concentric planar fabric parallel to the wall rock contact and lineations highly oblique to the foliation trend. The fabric of the Campina Grande pluton is consistent with a magma moving over a ramp dipping to southwest, with the lineation at high angle to the NE-trending flow direction. The contrasting structures of the plutons reflect the episodic nature of orogenic deformation, which was punctuated by the alternation of weak and strong strains, affecting the fabric development of the syntectonic intrusions.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-02-01

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

  19. 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.

  20. I/Ca records of local redox history for contrasting depositional environments during Cenomanian-Turonian OAE2

    Science.gov (United States)

    Lu, Z.; Zhou, X.; Junium, C. K.; Sageman, B. B.; Jenkyns, H.

    2012-12-01

    the global OAE imprint. The findings highlight the potential sensitivity of I/Ca as a proxy for reconstruction of redox histories.

  1. Contrast in stress-strain history during exhumation between high- and ultrahigh-pressure metamorphic units in the Western Alps: Microboudinage analysis of piemontite in metacherts

    Science.gov (United States)

    Omori, Yasutomo; Barresi, Antonello; Kimura, Nozomi; Okamoto, Atsushi; Masuda, Toshiaki

    2016-08-01

    Our analyses of microboudinage structures of piemontite grains embedded within six samples of metachert, one collected from an ultrahigh-pressure (UHP) metamorphic unit at Lago di Cignana in Italy of the Western Alps, and the other five from surrounding high-pressure (HP) metamorphic units in Italy and France, have revealed that the structures are all symmetrical in type, and were presumably produced in coaxial strain fields. Stress-strain analyses of the microboudinaged grains revealed significant contrasts in the stress and strain histories of the UHP and HP metamorphic units, with the differential stress recorded by the UHP sample being unequivocally lower than that recorded by the five HP samples. In addition, our analyses showed that the UHP sample underwent stress-relaxation during microboudinage, whereas the five HP samples did not. On the basis of these observations and analyses we discuss the mechanical decoupling of the UHP and HP units that led to different histories in differential stress between the units during exhumation of the Western Alps.

  2. [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.

  3. In hot and cold water: differential life-history traits are key to success in contrasting thermal deep-sea environments.

    Science.gov (United States)

    Marsh, Leigh; Copley, Jonathan T; Tyler, Paul A; Thatje, Sven

    2015-07-01

    Few species of reptant decapod crustaceans thrive in the cold-stenothermal waters of the Southern Ocean. However, abundant populations of a new species of anomuran crab, Kiwa tyleri, occur at hydrothermal vent fields on the East Scotia Ridge. As a result of local thermal conditions at the vents, these crabs are not restricted by the physiological limits that otherwise exclude reptant decapods south of the polar front. We reveal the adult life history of this species by piecing together variation in microdistribution, body size frequency, sex ratio, and ovarian and embryonic development, which indicates a pattern in the distribution of female Kiwaidae in relation to their reproductive development. High-density 'Kiwa' assemblages observed in close proximity to sources of vent fluids are constrained by the thermal limit of elevated temperatures and the availability of resources for chemosynthetic nutrition. Although adult Kiwaidae depend on epibiotic chemosynthetic bacteria for nutrition, females move offsite after extrusion of their eggs to protect brooding embryos from the chemically harsh, thermally fluctuating vent environment. Consequently, brooding females in the periphery of the vent field are in turn restricted by low-temperature physiological boundaries of the deep-water Southern Ocean environment. Females have a high reproductive investment in few, large, yolky eggs, facilitating full lecithotrophy, with the release of larvae prolonged, and asynchronous. After embryos are released, larvae are reliant on locating isolated active areas of hydrothermal flow in order to settle and survive as chemosynthetic adults. Where the cold water restricts the ability of all adult stages to migrate over long distances, these low temperatures may facilitate the larvae in the location of vent sites by extending the larval development period through hypometabolism. These differential life-history adaptations to contrasting thermal environments lead to a disjunct life history

  4. Demographic and life-history patterns in a population of ring-tailed lemurs (Lemur catta) at Beza Mahafaly Reserve, Madagascar: a 15-year perspective.

    Science.gov (United States)

    Gould, Lisa; Sussman, R W; Sauther, Michelle L

    2003-02-01

    Over 15 field seasons (1987-2001), we collected census and life-history data on a population of individually identified ring-tailed lemurs at the Beza Mahafaly Reserve, Madagascar. No significant difference was found in population size over the study period, though a marked decline in the population occurred following a 2-year drought. The population rebounded rapidly after the immediate postdrought period. There was nearly a complete replacement of individuals over the study period. Average group size is 11.5 animals, and adult male to female sex ratio is 0.92. Most females reproduce annually, and the average fecundity rate is 84.3%. The greatest variability in fecundity is found among old females. We suggest that ring-tailed lemur females follow an "income breeding" strategy, i.e., females use maximum resources during reproduction rather than relying on fat stores, as do "capital breeders." Infant mortality to 1 year of age in a nondrought year is 52%, higher than infant mortality in small to medium-sized anthropoids. The oldest known female was 18 years old in 2001. We suggest that 18-20 years may represent the maximum life-span for wild ring-tailed lemurs. Because males regularly emigrate from the population, we have no data regarding male life-span; however, there is some indication that males do not survive as long as females. Group fission has occurred three times: twice from one parent group living in the driest area of the reserve, with the most dispersed food resources. We suggest that the reproductive strategy that has evolved in this species, wherein females reproduce early in life and annually until old age, is a response to the unusual climate and environmental conditions under which Lemur catta has evolved.

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Ivana Rešetnik

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

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

    Science.gov (United States)

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

    2016-01-01

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

  8. 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.

  9. Contrasting Physiological Responses of Two Populations of the Razor Clam Tagelus dombeii with Different Histories of Exposure to Paralytic Shellfish Poisoning (PSP)

    Science.gov (United States)

    Navarro, Jorge M.; González, Katerina; Cisternas, Barbara; López, Jorge A.; Chaparro, Oscar R.; Segura, Cristian J.; Córdova, Marco; Suárez-Isla, Benjamín; Fernandez-Reiriz, María J.; Labarta, Uxio

    2014-01-01

    This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the presence of toxins in the diet. However, clams from Corral-Valdivia, which have never been exposed to PSP, exhibited significantly reduced filtration activity and absorption, affecting the energy allocated to scope for growth (SFG). Ammonia excretion and oxygen uptake were not affected significantly by the presence of A. catenella in the diet. Measurements of energy acquisition and expenditure were performed during a 12-day intoxication period. According to three-way repeated measure ANOVAs, the origin of the clams had a highly significant effect on all physiological variables, and the interaction between diet and origin was significant for the clearance and absorption rates and for the scope for growth. The scope for growth index showed similar positive values for both the toxic and non-toxic individuals from the Melinka-Aysén population. However, it was significantly reduced in individuals from Corral-Valdivia when exposed to the diet containing A. catenella. The absence of differences between the physiological response of the toxic and non-toxic clams from Melinka-Aysén may be related to the frequent presence of A. catenella in the environment, indicating that this bivalve does not suffer negative consequences from PSP. By contrast, A. catenella has a negative effect on the physiological performance, primarily on the energy gained from the environment, on T. dombeii from Corral-Valdivia. This study supports the hypothesis that the history of PSP exposure plays an important role in the physiological performance and fitness of filter feeding bivalves. PMID:25153329

  10. Contrasting physiological responses of two populations of the razor clam Tagelus dombeii with different histories of exposure to paralytic shellfish poisoning (PSP).

    Science.gov (United States)

    Navarro, Jorge M; González, Katerina; Cisternas, Barbara; López, Jorge A; Chaparro, Oscar R; Segura, Cristian J; Córdova, Marco; Suárez-Isla, Benjamín; Fernandez-Reiriz, María J; Labarta, Uxio

    2014-01-01

    This study describes the physiological performance of two populations of the razor clam Tagelus dombeii from two geographic areas with different histories of exposure to paralytic shellfish poisoning (PSP) linked to the toxic dinoflagellate Alexandrium catenella. Clams from Melinka-Aysén, which are frequently exposed to PSP, were not affected by the presence of toxins in the diet. However, clams from Corral-Valdivia, which have never been exposed to PSP, exhibited significantly reduced filtration activity and absorption, affecting the energy allocated to scope for growth (SFG). Ammonia excretion and oxygen uptake were not affected significantly by the presence of A. catenella in the diet. Measurements of energy acquisition and expenditure were performed during a 12-day intoxication period. According to three-way repeated measure ANOVAs, the origin of the clams had a highly significant effect on all physiological variables, and the interaction between diet and origin was significant for the clearance and absorption rates and for the scope for growth. The scope for growth index showed similar positive values for both the toxic and non-toxic individuals from the Melinka-Aysén population. However, it was significantly reduced in individuals from Corral-Valdivia when exposed to the diet containing A. catenella. The absence of differences between the physiological response of the toxic and non-toxic clams from Melinka-Aysén may be related to the frequent presence of A. catenella in the environment, indicating that this bivalve does not suffer negative consequences from PSP. By contrast, A. catenella has a negative effect on the physiological performance, primarily on the energy gained from the environment, on T. dombeii from Corral-Valdivia. This study supports the hypothesis that the history of PSP exposure plays an important role in the physiological performance and fitness of filter feeding bivalves.

  11. Population Structure, Genetic Diversity, Effective Population Size, Demographic History and Regional Connectivity Patterns of the Endangered Dusky Grouper, Epinephelus marginatus (Teleostei: Serranidae), within Malta’s Fisheries Management Zone

    Science.gov (United States)

    Vella, Adriana

    2016-01-01

    The objective of this study is to describe the genetic population structure and demographic history of the endangered marine fish, Epinephelus marginatus, within Malta’s Fisheries Management Zone for the purpose of localised conservation planning. Epinephelus marginatus is a long-lived, sedentary, reef-associated protogynous hermaphrodite with high commercial and recreational value that is at risk of extinction throughout its global distribution. Based on global trends, population substructuring and gaps in local knowledge this has led to an increased interest in evaluation of local stock. Assessment of Maltese demography was based on historical and contemporary catch landings data whilst genetic population structure and regional connectivity patterns were evaluated by examining 175 individuals collected within the central Mediterranean region between 2002 and 2009 using 14 nuclear microsatellite loci. Demographic stock assessment of Maltese E. marginatus’ revealed a 99% decline in catch landings between 1947 and 2009 within the Fisheries Management Zone. A contemporary modest mean size was observed, 3 ± 3 kg, where approximately 17% of the population was juvenile, 68% female/sex-changing and 15% were male with a male-to-female sex ratio of 1:5. Genetic analysis describes the overall population of E. marginatus’ within the Fisheries Management Zone as decreasing in size (ƟH = 2.2), which has gone through a significant size reduction in the past (M = 0.41) and consequently shows signs of moderate inbreeding (FIS = 0.10, p < 0.001) with an estimated effective population size of 130 individuals. Results of spatially explicit Bayesian genetic cluster analysis detected two geographically distinct subpopulations within Malta’s Fisheries Management Zone and that they are connected to a larger network of E. marginatus’ within the Sicily Channel. Results suggest conservation management should be designed to reflect E. marginatus’ within Malta’s Fisheries

  12. History of Red Crater volcano, Tongariro Volcanic Centre (New Zealand): Abrupt shift in magmatism following recharge and contrasting evolution between neighboring volcanoes

    Science.gov (United States)

    Shane, Phil; Maas, Roland; Lindsay, Jan

    2017-06-01

    Red Crater volcano is one of several contemporaneously active vents on the Tongariro Volcanic Centre. Its history provides an opportunity to investigate the contrasting magmatic evolutionary paths of closely-spaced volcanoes. Rocks erupted at Red Crater over the last 3.4 ka display typical subduction-related trace element and isotopic signatures. Those erupted pre-1.8 ka are medium-K andesites (SiO2 59-62 wt%). They represent the most voluminous magmas and were emplaced in 5 lava flow events. An abrupt shift to the eruption of basaltic andesite (SiO2 53-54 wt%) with less radiogenic Sr-Nd-Pb isotope ratios, occurred post-1.8 ka. This period comprised 6 smaller volume, lava flow episodes and the contemporaneous development of a scoria cone. Plagioclase phenocrysts in post-1.8 ka lava flows have resorbed cores with diverse textural and compositional growth patterns, as would be expected from the disruption of a crystal mush. They are similar to phenocrysts of the pre-1.8 ka lava flows. The post-1.8 ka plagioclase is distinguished from those in the older lavas by overgrowths with elevated An ( 70-90), FeO and MgO contents, that mantle the resorbed cores ( An50-70). These rims are compositionally similar to groundmass plagioclase. This demonstrates that new mafic magma was intruded into the system, mixing with and entraining relic crystals from the older andesite system. Iron and Mg zoning patterns in the crystals are not consistent with significant re-equilibration via diffusion. Hence, the generation of eruptible magma during the last 1.8 ka required repeated mafic intrusion events. The emptying of the older andesitic magma reservoir early in the volcano's history removed buoyancy barriers to the direct eruption of more mafic magmas. This pattern of magmatism is not recorded at the contemporaneously active Ngauruhoe volcano, just 3 km to the SSW. Ngauruhoe rocks are compositionally distinct and are more heterogeneous in isotopic composition. Although mafic recharge is

  13. Contrast Materials

    Science.gov (United States)

    ... Physician Resources Professions Site Index A-Z Contrast Materials What are contrast materials and how do they ... material? Pregnancy and contrast materials What are contrast materials and how do they work? Contrast materials, also ...

  14. Evolutionary shaping of demographic schedules

    Science.gov (United States)

    Wachter, Kenneth W.; Steinsaltz, David; Evans, Steven N.

    2014-01-01

    Evolutionary processes of natural selection may be expected to leave their mark on age patterns of survival and reproduction. Demographic theory includes three main strands—mutation accumulation, stochastic vitality, and optimal life histories. This paper reviews the three strands and, concentrating on mutation accumulation, extends a mathematical result with broad implications concerning the effect of interactions between small age-specific effects of deleterious mutant alleles. Empirical data from genomic sequencing along with prospects for combining strands of theory hold hope for future progress. PMID:25024186

  15. Democratic constraints on demographic policy.

    Science.gov (United States)

    Grigsby, J S

    1984-01-01

    The discussion compares the population policies adopted in Sweden during the 1930s to raise fertiity and the policies considered in the US during the 1970s in response to the high fertility experienced in the 1950s. Both sets of policies recommended increased availability of birth control, more liberal abortion laws, and greater employment opportunities for women. It becomes evident that the constraints imposed by a democratic system of government translate into policy recommendations that place individual freedom of choice and equal opportunity for all citizens as higher goals than any specific demographic target. Consequently, the population commissions of Sweden and the US made similar suggestions on how to resolve their opposite demographic problems. The demographic situations in the 2 nations were antipodal, and the countries also had very different social climates. This additional disparity was insufficient to counterbalance the apparently overwhelming influence of the democratic political systems in making virtually identical policy recommendations. Yet, the contrasting social climates of Sweden in 1935 and the US in 1970-72 may explain the different reactions each commission received. In terms of the responses by both citizens and government officials to the commissions' reports, the Swedish commission was more successful. Practically all of their recommendations were enthusiastically received and quickly adopted by the Swedish Riksdag. Yet, when the criterion for success becomes whether or not a demographic target was met, it increased in the 1940s and then dropped again while the same social policies were in effect. Even before the US commission began its study, fertility in the US had fallen and continues to remain low. These findings suggest that commissions in democratic countries will most likely never recommend dramatic measures in population policy. Thus, it is questionable whether such commissions in democratic nations will totally fulfill the

  16. 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.

  17. 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...

  18. 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.

  19. Divergent ecological histories of two sister Antarctic krill species led to contrasted patterns of genetic diversity in their heat-shock protein (hsp70) arsenal.

    Science.gov (United States)

    Papot, Claire; Cascella, Kévin; Toullec, Jean-Yves; Jollivet, Didier

    2016-03-01

    The Arctic and the Antarctic Peninsula are currently experiencing some of the most rapid rates of ocean warming on the planet. This raises the question of how the initial adaptation to extreme cold temperatures was put in place and whether or not directional selection has led to the loss of genetic variation at key adaptive systems, and thus polar species' (re)adaptability to higher temperatures. In the Southern Ocean, krill represents the most abundant fauna and is a critical member at the base of the Antarctic food web. To better understand the role of selection in shaping current patterns of polymorphisms, we examined genetic diversity of the cox-1 and hsp70 genes by comparing two closely related species of Euphausiid that differ in ecology. Results on mtcox-1 agreed with previous studies, indicating high and similar effective population sizes. However, a coalescent-based approach on hsp70 genes highlighted the role of positive selection and past demographic changes in their recent evolution. Firstly, some form of balancing selection was acting on the inducible isoform C, which reflected the maintenance of an ancestral adaptive polymorphism in both species. Secondly, E. crystallorophias seems to have lost most of its hsp70 diversity because of a population crash and/or directional selection to cold. Nonsynonymous diversities were always greater in E. superba, suggesting that it might have evolved under more heterogeneous conditions. This can be linked to species' ecology with E. superba living in more variable pelagic conditions, while E. crystallorophias is strictly associated with continental shelves and sea ice.

  20. ddRAD-seq phylogenetics based on nucleotide, indel, and presence-absence polymorphisms: Analyses of two avian genera with contrasting histories.

    Science.gov (United States)

    DaCosta, Jeffrey M; Sorenson, Michael D

    2016-01-01

    Genotype-by-sequencing (GBS) methods have revolutionized the field of molecular ecology, but their application in molecular phylogenetics remains somewhat limited. In addition, most phylogenetic studies based on large GBS data sets have relied on analyses of concatenated data rather than species tree methods that explicitly account for genealogical stochasticity among loci. We explored the utility of "double-digest" restriction site-associated DNA sequencing (ddRAD-seq) for phylogenetic analyses of the Lagonosticta firefinches (family Estrildidae) and the Vidua brood parasitic finches (family Viduidae). As expected, the number of homologous loci shared among samples was negatively correlated with genetic distance due to the accumulation of restriction site polymorphisms. Nonetheless, for each genus, we obtained data sets of ∼3000 loci shared in common among all samples, including a more distantly related outgroup taxon. For all samples combined, we obtained >1000 homologous loci despite ∼20my divergence between estrildid and parasitic finches. In addition to nucleotide polymorphisms, the ddRAD-seq data yielded large sets of indel and locus presence-absence polymorphisms, all of which had higher consistency indices than mtDNA sequence data in the context of concatenated parsimony analyses. Species tree methods, using individual gene trees or single nucleotide polymorphisms as input, generated results broadly consistent with analyses of concatenated data, particularly for Lagonosticta, which appears to have a well resolved, bifurcating history. Results for Vidua were also generally consistent across methods and data sets, although nodal support and results from different species tree methods were more variable. Lower gene tree congruence in Vidua is likely the result of its unique evolutionary history, which includes rapid speciation by host shift and occasional hybridization and introgression due to incomplete reproductive isolation. We conclude that dd

  1. 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.

  2. Demographic changes and nationalism.

    Science.gov (United States)

    Vishnevskii, A G

    1995-01-01

    This article examines the different characteristics of the many peoples inhabiting what used to be the Soviet Union and communist Eastern Europe, including Yugoslavia. The differences among these nationalities, or ethnic groups, are illustrated using the example of demographic modernization, showing how different peoples have or have not passed through the demographic transition process. The author looks at ethnic differences in mortality, fertility, natural increase, and migration, as well as economic and social inequalities among ethnic groups. The prospects for inter-ethnic conflict are assessed.

  3. Contrastive Lexicology.

    Science.gov (United States)

    Hartmann, R. R. K.

    This paper deals with the relation between etymologically related words in different languages. A survey is made of seven stages in the development of contrastive lexicology. These are: prelinguistic word studies, semantics, lexicography, translation, foreign language learning, bilingualism, and finally contrastive analysis. Concerning contrastive…

  4. 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 findi...

  5. 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.

  6. Building demographic literacy.

    Science.gov (United States)

    Crews, K

    1993-01-01

    Students should get in the habit of seeking out the most current projections, estimates, or rates available. Since demographic measures change over time, publications based on the UN's world population projections from 1980 or 1990 may need to be supplemented using the UN's most current, 1992, projections. A 1989 Census Bureau report on the African American Population will not contain data from the 1990 Census or the 1992 Current Population Survey, conducted by the Census Bureau. Some groups collect data with advocacy in mind, as shown by the range of estimates of participants at the 1993 National March on Washington for Lesbian, Gay and Bi Equal Rights and Liberation. The organizers estimated that 1 million people participated; the US Park Police estimated 300,000; and the Washington Blade, a gay newspaper, reported 750,000. A seemingly innocuous choice of phrasing can change the meaning of demographic data. One commonly misreported concept is population doubling time which is not a prediction, but rather a concept designed to accent how fast a population is growing at the present time. At current rates, the population of India would double in size in 34 years, but it is more likely that growth rates will begin to slow down somewhat during that time. Older students may be encouraged to examine the assumptions behind population projections. The UN's long-range projection that world population will grow to 10 billion by 2050 is based on certain assumption about fertility and mortality during the period. With regard to the fastest growing US minority, Hispanics added the largest number of people to the US population during the 1980s, but Asians had the largest percent increase. The time to initiate demographic literacy is in the early grades of school.

  7. 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...

  8. Contrasting `Oceanic Anoxic Events' in Earth's History

    Science.gov (United States)

    Clarkson, M. O.; Stirling, C. H.; Jenkyns, H. C.; Cooke, I. R.; Dickson, A.; Porcelli, D.; Pogge von Strandmann, P.

    2016-12-01

    Oxygen is fundamental to the evolution of life and a lack of oxygen in marine environments is often cited as a causal mechanism for mass extinctions. Anoxia was likely a main contributor to the Permo-Triassic extinction and also important for causing the delayed and complex recovery that took place during the Early Triassic. Despite strong evidence for anoxia, at various places, times and water depths, the extended Permo-to-Early Triassic interval was exceptionally complex and multiple environmental pressures occurred simultaneously. Each kill-mechanism holds a unique position in the carbon cycle and yet they are all inter-related. For example, oceanic anoxia is intimately linked to changes in weathering and nutrient availability, biological productivity and temperature increases. It also represents one of many powerful mechanisms that can help stabilize the global climate, where carbon burial under anoxic conditions can drive dramatic cooling. Here we examine the details of anoxia development for the Permo-Triassic extinction and Early Triassic recovery period, calling upon comparisons to the well-studied Mesozoic Oceanic Anoxic Events (OAEs). The OAEs represent discrete intervals of anoxia that may offer a framework for understanding oxygenation around the Permo-Triassic. In particular, we question whether the Early Triassic represents a series of separate carbon-cycle perturbations, like the OAEs, or a complex internal response to extreme environmental change. We present independent evidence for the global extent of anoxia during OAE2, using 238U/235U (δ238U). These data are placed into the wider carbon-cycle context in order to unravel the driving mechanisms and potential feedback responses of anoxia development. This conceptual OAE model will then be applied to the complexities of the extended Permo-Triassic interval to examine the details of carbon cycle behaviour.

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

    Science.gov (United States)

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

    2016-07-01

    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.

  10. Significant demographic and fine-scale genetic structure in expanding and senescing populations of the terrestrial orchid Cymbidium goeringii (Orchidaceae).

    Science.gov (United States)

    Chung, Mi Yoon; Nason, John D; Chung, Myong Gi

    2011-12-01

    Fine-scale genetic structure (FSGS) in plants is influenced by variation in spatial and temporal demographic processes. To determine how demographic structure and FSGS change with stages of population succession, we studied replicate expanding and senescing populations of the Asian terrestrial orchid Cymbidium goeringii. We used spatial autocorrelation methods (O-ring and kinship statistics) to quantify spatial demographic structure and FSGS in two expanding and two senescing populations, also measuring genetic diversity and inbreeding in each. All populations exhibited significant aggregation of individuals and FSGS at short spatial scales. In expanding populations, this finding was associated with high recruitment rates, suggesting restricted seed dispersal. In senescing populations, recruitment was minimal, suggesting alternative mechanisms of aggregation, perhaps including spatial associations with mycorrhizal fungi. All populations had significant evidence of genetic bottlenecks, and inbreeding levels were consistently high. Our results indicate that different successional stages can generate similar patterns of spatial demographic and genetic structure, but as a consequence of different processes. These results contrast with the only other study of senescence effects on population genetic structure in an herbaceous perennial, which found little to no FSGS in senescing populations. With the exception of populations subject to mass collection by orchid sellers, significant FSGS is characteristic of the 16 terrestrial orchid species examined to date. From a conservation perspective, this result suggests that inference of orchid population history will benefit from analyses of both FSGS and demographic structure in combination with other ecological field data.

  11. Demographic trends in Sweden

    Directory of Open Access Journals (Sweden)

    2004-08-01

    Full Text Available In the present note, we present the main features of recent trends in vital family-demographic behavior in Sweden. For this purpose, published indices of marriage, divorce, and childbearing risks by calendar year are updated by adding another two or three years of observation to our series. We demonstrate that the latest trend reversal in Swedish birth rates, which occurred at the end of the 1990s, continued to manifest itself in increasing propensities for childbearing during the early years of the 21st century. The rise pertains to all birth orders. Marriage propensities showed an increase as well, however, to a large extent expressed in a short-term development that was prevalent at the turn of the millennium. The previous long-term trend of rising divorce risks leveled off during the first two years of the new century.

  12. 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

  13. [Demographic profile of Venezuela].

    Science.gov (United States)

    Quintero, I

    1984-04-01

    Sources of demographic data for Venezuela include 11 population censuses conducted between 1873-1981, birth and death registration statistics, and the household sample survey. The average annual rate of population growth increase from 2.8% between 1920-40 to 3-4% thereafter. The population at the 1961 census was 7.52 million. According to preliminary data from the 1981 census, the population of 14.57 million is growing at an annual rate of 2.8%. 41.2% of the population is under 15 years old, implying a huge demand for educational and health services, housing and employment. The dependency rate in 1980 was 81.3% for the country as a whole, 100.4% in rural areas, and 76.0% in urban areas. The young age structure means that the population will continue to grow even if natality rates decline. The crude natality rate was estimated at 47.3/1000 for 1950-55, 36.0 for 1970-75, and 32.9 for 1980-85. Some rural areas still have natality rates of over 47/1000. The total fertility rate declined from 6.5 in 1950-55 to 4.1 in 1980-85. The decline in the natality rate reflects improving quality of life, availability of family planning services, urbanization, and access of women to productive activities and educational centers. The mortality rate was 12.3/1000 in 1950-55, 9.1 in 1960-65, in 1970-75, and has been estimated at 5.5 for 1980-85. Some rural areas have mortality rates of 8.1. The infant mortality rate was 50.2/1000 in 1971 and 34.3 in 1980. Life expectancy at birth is about 69 years. During the 1920s, Venezuela unerwent expansion in infrastructure and technological utilization, generating rapid urbanization. 39.2% of the population was urban in 1941, compared to 78.8% in 1980. The significance of urbanization in Venezuela is due to the rapidity as well as the diffusion of the process. The household sample survey for the 2nd half of 1980 indicated a total of 8.16 million employed and an activity rate of 32.1% overall, 46.4% for males and 17.7% for females. The

  14. Tidal disruption event demographics

    Science.gov (United States)

    Kochanek, C. S.

    2016-09-01

    We survey the properties of stars destroyed in tidal disruption events (TDEs) as a function of black hole (BH) mass, stellar mass and evolutionary state, star formation history and redshift. For M_{BH} ≲ 10^7 M_{⊙}, the typical TDE is due to a M* ˜ 0.3 M⊙ M-dwarf, although the mass function is relatively flat for M_{ast } ≲ M_{⊙}. The contribution from older main-sequence stars and sub-giants is small but not negligible. From MBH ≃ 107.5-108.5 M⊙, the balance rapidly shifts to higher mass stars and a larger contribution from evolved stars, and is ultimately dominated by evolved stars at higher BH masses. The star formation history has little effect until the rates are dominated by evolved stars. TDE rates should decline very rapidly towards higher redshifts. The volumetric rate of TDEs is very high because the BH mass function diverges for low masses. However, any emission mechanism which is largely Eddington-limited for low BH masses suppresses this divergence in any observed sample and leads to TDE samples dominated by MBH ≃ 106.0-107.5 M⊙ BHs with roughly Eddington peak accretion rates. The typical fall-back time is relatively long, with 16 per cent having tfb plausible if tfb has any relation to the transient rise time. For almost any BH mass function, systematic searches for fainter, faster time-scale TDEs in smaller galaxies, and longer time-scale TDEs in more massive galaxies are likely to be rewarded.

  15. Demographic Trends: Impact on Schools

    Science.gov (United States)

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

    2010-01-01

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

  16. 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

  17. 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.

  18. Predicting Psychiatric Rehabilitation Outcome Using Demographic Characteristics: A Replication

    Science.gov (United States)

    Anthony, William A.; Buell, Gregory J.

    1974-01-01

    Replication was undertaken of a recent study conducted by Buell and Anthony which had found that recidivism and posthospital employment could be predicted by a single demographic variable, number of previous hospitalizations and employment history, respectively. Results of the replication were consistent for posthospital employment but not for…

  19. 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...

  20. EJSCREEN Demographic Indicators 2015 Internal

    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...

  1. 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...

  2. 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

  3. DEMOGRAPHIC VULNERABILITIES IN TECUCI PLAIN

    Directory of Open Access Journals (Sweden)

    Iulian Adrian ŞORCARU

    2013-06-01

    Full Text Available The study focuses on analyzing and mapping 8 indicators considered to best reflect the demographic vulnerability in Tecuci Plain in the year 2010 and proposes a model of aggregation which finally allows us to distinguish three major types of demographic vulnerability (low, medium and high. Mapping the final values also shows significant disparities in the territorial administrative units that broadly overlap the plain, the most vulnerable being Tecuci city and the peripheral communes, towards Vrancea and Vaslui Counties.

  4. 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.

  5. Demographic history of european populations of Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Olivier François

    2008-05-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    a little over 10 000 years ago, consistent with the last proposed isolation of the Baltic Sea. Approximate Bayesian computation also identified genetic signals consistent with postglacial population expansion across much of the species range, suggesting that grey seals are highly responsive to changes...

  7. Tourism Market and Demographic Changes

    Directory of Open Access Journals (Sweden)

    Alexandru Nedelea

    2008-10-01

    Full Text Available This paper identifies the major demographic trends and their implications for consumer market. It is important to know how will demographic change influence the tourism market in particularly and how can the tourist industry adapt to these. The advancing ageing of society will result in far reaching changes, particularly on the demand side. To profitably seize the opportunities, managers must understand how senior markets evolve and adapt products and service offerings along multiple dimensions to meet the needs of senior consumers.

  8. Million-year melt-presence in monotonous intermediate magma for a volcanic-plutonic assemblage in the Central Andes: Contrasting histories of crystal-rich and crystal-poor super-sized silicic magmas

    Science.gov (United States)

    Kaiser, Jason F.; de Silva, Shanaka; Schmitt, Axel K.; Economos, Rita; Sunagua, Mayel

    2017-01-01

    crystallized as a granodiorite pluton which was sampled as xenoliths in much later volcanic events. Over the ∼1.1 Ma zircon crystallization history for the PGI, postcaldera lavas and xenoliths, the melt remained in an ∼100-150 °C temperature window as indicated by Ti-in-zircon thermometry. Although chemical trends are consistent with zircon crystallization at variable temperatures, there is no secular cooling, but rather a thermal rejuvenation following the 2.89 Ma PGI eruption. As such these data provide a "low and slow" temporal constraint for models for the pre-eruptive lifetimes of mushy magma in contrast to the "rapid" mobilization of crystal-poor silicic magmas, consistent with a model where the latter are incubated within the former and extracted rapidly prior to eruption. The thermal and chemical monotony of crystal-rich dacites throughout a caldera cycle connotes conditions where near-eutectic melt can be maintained in near-surface magma reservoirs for an extended period of time if the subvolcanic magma reservoir is sufficiently large so that hotter and initially zircon-undersaturated magma can replenish shallow magma vented in a supereruption.

  9. A Statistical Assessment of Demographic Bonus towards Poverty Alleviation

    Directory of Open Access Journals (Sweden)

    Jamal Abdul Nasir

    2011-09-01

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

  10. 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...

  11. Logistics Dynamics and Demographic Change

    NARCIS (Netherlands)

    Klumpp, Matthias; Abidi, Hella; Bioly, Sascha; Buchkremer, Rüdiger; 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. Portraying User Interface History

    DEFF Research Database (Denmark)

    Jørgensen, Anker Helms

    2008-01-01

    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...... 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...

  13. Febrile Seizure: Demographic Features and Causative Factors

    Directory of Open Access Journals (Sweden)

    Hamed ESMAILI GOURABI

    2012-10-01

    Full Text Available ObjectiveBecause of geographical and periodical variation, we prompted to determine the demographic features and causative factors for febrile seizure in Rasht.Materials & MethodsIn this cross-sectional study, all 6–month- to 6-year-old children with the diagnosis of febrile seizure admitted to 17 Shahrivar hospital in Rasht, from August, 2009 to August, 2010 were studied. Age, sex, family history of the disease, seizure types, body temperature upon admission and infectious causes of the fever were recorded. All statistical analysis was performed with SPSS software, version 16.ResultsOf the 214 children (mean age, 25.24±15.40 months, 124 were boys and 109 had a positive family history. Complex seizures were seen in 39 cases. In patients with a complex febrile seizure, 59% had the repetitive type, 20.5% had the focal type and 20.5% had more than 15 minutes duration of seizures. Most of the repetitive seizures (78.3% occurred in patients under 2 years old; the difference between under and over 2-year-old patients was statistically significant (P=0.02. Study results did not show significant differences between the two genders for simple or complex seizures. The mean body temperature upon admission was 38.2±1.32◦C (38.31±0.82 degrees in boys and 38.04±1.78 in girls. Upper respiratory infections were seen in most patients (74.29%. All cases of lower respiratory infections were boys. There was a statistically significant difference between boys and girls in causes of fever.ConclusionMost of the children had a positive family history and the most common causative factor was upper respiratory infection.

  14. Demographic characteristics of exploited tropical lutjanids: a comparative analysis

    OpenAIRE

    Heupel, Michelle R.; Williams, Ashley A.; David J. Welch; Campbell R. Davies; Penny, Ann; Jacob P Kritzer; Marriott, Ross J.; Bruce D. Mapstone

    2010-01-01

    Demographic parameters from seven exploited coral reef lutjanid species were compared as a case study of the implications of intrafamily variation in life histories for multispecies harvest management. Modal lengths varied by 4 cm among four species (Lutjanus fulviflamma, L. vitta, L. carponotatus, L. adetii), which were at least 6 cm smaller than the modal lengths of the largest species (L. gibbus, Symphorus nematophorus, Aprion virescens). Modal ages, indicating ages of full selection to...

  15. 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.)

  16. Comparative demographics of a Hawaiian forest bird community

    Science.gov (United States)

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

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

    Science.gov (United States)

    Al-Shammri, Suhail N.; Hanna, Magdy G.; Chattopadhyay, Arpita; Akanji, Abayomi O.

    2015-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Suhail N Al-Shammri

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

  19. DEMOGRAPHIC FACTOR OF ECOLOGICAL POLICY

    OpenAIRE

    2015-01-01

    Demographic factor of ecological policy is analyzed. Анализируется демографическая составляющая экологической политики. Аналізується демографічна складова екологічної політики.

  20. SELECTED DETERMINANTS OF DEMOGRAPHIC SAFETY

    Directory of Open Access Journals (Sweden)

    Stanisława Ostasiewicz

    2016-09-01

    Full Text Available The article presents, in a simplifi ed manner, selected theories of population to explain the current trends of population development in Poland and throughout the world. The aim of the article is to present the demographic threats that have emerged in the last eighty years. Prognosticated age structures have also been predicted. Signifi cant diff erences between the structure of the population now and the future have been indicated, particularly regarding the ageing of the population. Against the background of global transformations analyzes of changes in Poland have been conducted. The comparison shows that changes in Poland are highly analogous to transformations around the world, such as declining birth rates and increasing life expectancy. These changes cause ageing of the population, which could result in the collapse of the functioning of the labor market and the pension system as it currently exists.

  1. Demographic Ageing on Croatian Islands

    Directory of Open Access Journals (Sweden)

    Ivo Nejašmić

    2013-08-01

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

  2. 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.

  3. Contrast-induced nephropathy

    Directory of Open Access Journals (Sweden)

    Ricardo A. García Hernández

    2016-06-01

    Full Text Available Contrast-induced nephropathy is an important complication associated with the use of contrast media. Favoring factors for the development of contrast-induced nephronpathy have been widely described, being diabetes mellitus and previous renal disease the greatest risk. The pathophysiology is a complex process where the medullary hypoxia represents the trigger element. Previous hydration and the use of low osmolality contrast are the most recommended measures to prevent its development.

  4. Febrile Seizure: Demographic Features and Causative Factors

    Directory of Open Access Journals (Sweden)

    Hamed ESMAILI GOURABI

    2013-01-01

    Full Text Available How to cite this article: Esmaili Gourabi H, Bidabadi E, Cheraghalipour  F, Aarabi  Y, Salamat F. Febrile Seizure: Demographic Features and Causative Factors. Iran J Child Neurol Autumn 2012; 6(4:33-37.Abstract Objective Because of geographical and periodical variation, we prompted to determine the demographic features and causative factors for febrile seizure in Rasht. Materials & Methods In this cross-sectional study, all 6–month- to 6-year-old children with the diagnosis of febrile seizure admitted to 17 Shahrivar hospital in Rasht, from August, 2009 to August, 2010 were studied. Age, sex, family history of the disease, seizure types, body temperature upon admission and infectious causes of the fever were recorded. All statistical analysis was performed with SPSS software, version 16. Results Of the 214 children (mean age, 25.24±15.40 months, 124 were boys and 109 had a positive family history. Complex seizures were seen in 39 cases. In patients with a complex febrile seizure, 59% had the repetitive type, 20.5% had the focal type and 20.5% had more than 15 minutes duration of seizures. Most of the repetitive seizures (78.3% occurred in patients under 2 years old; the difference between under and over 2-year-old patients was statistically significant (P=0.02. Study results did not show significant differences between the two genders for simple or complex seizures. The mean body temperature upon admission was 38.2±1.32◦C (38.31±0.82 degrees in boys and 38.04±1.78 in girls. Upper respiratory infections were seen in most patients (74.29%. All cases of lower respiratory infections were boys. There was a statistically significant difference between boys and girls in causes of fever. Conclusion Most of the children had a positive family history and the most common causative factor was upper respiratory infection.  References: Huang MC, Huang CC, Thomas K. Febrile convulsions: development and validation of a questionnaire to measure

  5. 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.

  6. A Contrastive Study of American and Chinese Principal’s Ideas of University Running in the History of Lingnan University%岭南大学校史上中外校长办学理念的差异

    Institute of Scientific and Technical Information of China (English)

    孙清海

    2015-01-01

    The idea of how to run a university for a principal is very important.Lingnan University,as a Christian College at its beginning,was founded by a group of American missionary,who held the idea of claiming the Gospel and training Christians,but they ignored the influence of Chinese feelings of nationalism and patriotism.However, ZHONG Rongguang,a Chinese principal,made adaptation of the idea to emphasize the practical education,and al-so raise money aboard for many times,and then managed to develop Lingnan into a multi-diciplinary and compre-hensive university.Thus,by contrast,we can get a better understanding on the important role a principal plays in the development of a university.%大学校长的办学理念对一所大学的发展极其重要。岭南大学是一所教会大学,最初是由一批美国传教士所建立的,其坚持以传教为主的办学理念,但忽略了中国民众的民族主义和爱国主义情感的影响。而钟荣光校长掌舵岭大后,因势利导地调整办学理念为“以实用教育为主”,且多次赴海外筹款,最终把岭大发展成为多学科综合性大学。通过对岭南大学校史上中外校长办学理念的对比,更有利于我们看清校长对于大学发展所起到的灵魂性的主导作用。

  7. 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.

  8. Sequence Analysis in Demographic Research

    Directory of Open Access Journals (Sweden)

    Billari, Francesco C.

    2001-01-01

    Full Text Available EnglishThis paper examines the salient features of sequence analysis in demogrpahicresearch. The new approach allows a holistic perspective on life course analysis and is based on arepresentation of lives as sequences of states. Some of the methods for analyzing such data aresketched, from complex description to optimal matching ot monoethetic divisive algorithms. Afer ashort ilustration of a demographically-relevant example, the needs in terms of data collection and theopportunities of applying the same aproach to synthetic data are discussed.FrenchOn examine ici les principaux éléments de l’analyse par séquence endémographie. Cette nouvelle technique permet une perspective unifiée del’analyse du cours de la vie, en représentant la vie comme une série d’états.Certaines des méthodes pour de telles analyses sont décrites, en commençant parla description complexe, pour considérer ensuite les alignements optimales, etles algorithmes de division. Après un court exemple en démographie, onconsidère les besoins en données et les possibilités d’application aux donnéessynthétique.

  9. Demographic changes and international factor mobility

    OpenAIRE

    2004-01-01

    This paper reviews the extent and policy implications of linkages between demographic changes and international factor mobility. Evidence is found of significant demographic effects on both migration and the current account, but for different reasons neither increased migration nor international transfers of savings is expected to offer much assistance in digesting the variety of demographic transitions expected over the next fifty years. The paper also examines more briefly the effects of de...

  10. Community History.

    Science.gov (United States)

    Lewis, Helen M.

    1997-01-01

    Recounts the experience of researching community history in Ivanhoe, Virginia, between 1987 and 1990. The Ivanhoe History Project involved community members in collecting photographs, memorabilia, and oral histories of their town. Subsequent published volumes won the W. D. Weatherford Award and inspired a quilt exhibit and a theatrical production.…

  11. 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

  12. Demographic characteristics of patients with pulmonary thromboembolism

    Directory of Open Access Journals (Sweden)

    Ali Duman

    2015-03-01

    Full Text Available Objective: Pulmonary thromboembolism (PTE is a common disease with high mortality and difficult diagnosis.The incidence in our country cannot be calculated because there is no adequate and regular data. In our study,we aimed to investigate the demographic characteristics,risk factors, incidence, Wells and Geneva scores diagnostic and treatment methods of the patients in our emergency department with a diagnosis of PTE. Methods:Files of the 112 patients who were admitted to Erciyes University Medical Faculty Emergency Department between January 2010 - February 2012 were analyzed retrospectively. Data were analyzed with SPSS 17.0 statistical software. Results:The mean age of patients was 65.02 ± 16.23.Forty-one (36.6% of the patients were male and 71 (63.4% were female. The most common complaint of patients was shortness of breath (81.3%, respectively.Immobilization(35.7% and history of previous surgery(19.6% were among the risk factors of the patients. Average troponin levels of the patients was 0.13 ± 0.48 ng/Land average d-dimer levels was 12.698.12 ± 8.779.92 μg/L. Geneva scores of the patients were: 4 patients (3.6% low score, 88 patients (78.6% medium score and 20 patients (17.9% high score. Wells Clinical Probability scores of the patients were; 1 patient (0.9% low probability, 74 patients (66.1% intermediate probability and 37 patients (33% high probability. In the treatmentof patients; heparin infusion (36.6%, enoxaparin sodium(59.8% and tPA (3.6% were used. Conclusion: In spite of improvements in diagnosis and treatment methods, pulmonary embolism diagnosis is stil a problem. The first step to diagnosis in patients with risk factors begin to suspect.J Clin Exp Invest 2015; 6 (1:10-15

  13. 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...... 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....

  14. Contrast induced nephropathy

    DEFF Research Database (Denmark)

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

    2011-01-01

    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....

  15. Contrast induced nephropathy

    DEFF Research Database (Denmark)

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

    2011-01-01

    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....

  16. A Contrastive Study of Fan Wenlan′s Compendium of Chinese History and Qian Mu′s Outline of Chinese History%范文澜《中国通史简编》与钱穆《国史大纲》比较研究

    Institute of Scientific and Technical Information of China (English)

    赵梅春

    2014-01-01

    范文澜《中国通史简编》、钱穆《国史大纲》在有关中国历史发展进程、动因、主体等问题上,表现出了不同甚至对立的观点,代表了20世纪三四十年代关于中国历史的两种不同认识。《中国通史简编》强调经济基础在历史发展中的决定作用,认为人民群众的革命斗争是历史发展的直接推动力,而中国历史在这两股力量的推动下不断从低级社会形态向高级社会形态发展,合乎人类历史发展的一般规律。《国史大纲》则力图证明中国历史是在民族文化与民族精神的推动下,以士大夫阶层为领导,于和平的环境中以舒齐的步骤不断进步,有异于在斗争中凸显其活力的西方社会。有关中国历史认识的这种差异,一方面反映出其撰述者用以考察中国历史的指导思想有别,另一方面则折射出面对历史巨变人们所采取的应变对策的不同。《中国通史简编》第一次系统地说出了革命者对中国历史的全部看法,而《国史大纲》则更多地代表传统知识分子面对国家民族危机所采取的应变策略。不难看出,人们对历史的认识,不仅受制于其历史观,同时也与其对现实社会的思考和历史前途的憧憬密切相关。%Both Fan Wenlan's Compendium of Chinese History and Qian Mu's Outline of Chinese History show different and even opposing views on the Chinese historical development, motivation, subjects, and other issues, representing two different understandings of Chinese history in the 1930s and 1940s. The former emphasizes that the economic basis plays a decisive role in historical develop-ment. The people's revolutionary struggle is the direct driving force of historical development, and Chinese history will constantly develop from the lower form of social development to the higher under the impetus of these two forces, in line with the general law of development of human history

  17. Contrastive analyses of medical history of psychiatry outpatient service at different time-points%精神科门诊不同时点病例资料对比分析

    Institute of Scientific and Technical Information of China (English)

    李文飞; 王克永; 夏海森; 陶领知; 程林

    2009-01-01

    目的 探讨不同时点精神科门诊就诊结构及治疗状况. 方法 抽取2006年1月1日~2月10日在我院门诊就诊的480例精神病患者设为研究组,抽取2001年1月1日~2月10日在我院门诊就诊的404例精神病患者设为对照组.统计两组患者的一般资料、疾病诊断及药物治疗状况并进行对比分析. 结果 两组一般资料均无显著性差异(P>0.05);研究组情感性精神病、疑似精神分裂症诊断率显著高于对照组,而分裂样精神病诊断率显著低于对照组(P均<0.01);抗精神病药物奋乃静、舒必利选择率显著低于对照组,而阿立哌唑、喹硫平选择率显著高于对照组(P<0.01);抗抑郁剂曲唑酮、氟西汀选择率显著低于对照组,而舍曲林、帕罗西汀、西酞普兰选择率显著高于对照组(P<0.05或0.01);情绪稳定剂丙戊酸钠选择率显著高于对照组(P<0.01);苯二氮(艹)/(卓)类药物氯硝西泮选择率显著低于对照组(P<0.01). 结论 精神科门诊就诊者情感性精神病及疑似精神分裂症诊断率显著增加,而分裂样精神病诊断率显著下降;新型抗精神病药物及新型抗抑郁剂使用率有明显增加趋势;苯二氮(艹)/(卓)类药物使用率有显著下降趋势.首诊病程尚无变化,人们对精神疾病的认识依然不足,有关职能部门应进一步加大宣传力度,提高人们对精神疾病的认识能力,以利于早发现、早就医.%Objective To explore the structure of doctors' office visiting and therapeutic status at psychiatry outpatient service at different time-points. Methods 480 patients with psychosis who visited doctors' office at outpatient service of our hospital from Jan. 1 to Feb. 10, 2006 were assigned to research group and 404 ones from Jan. 1 to Feb. 10, 2001 to control group.General data,disease diagnosis and medication status were added up and analyzed contrastively. Results There were no significant differences in general data(P>0

  18. 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.

  19. 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…

  20. 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... (CONTINUED) FEDERAL EMPLOYEES RETIREMENT SYSTEM-GENERAL ADMINISTRATION Government Costs § 841.404 Demographic factors. (a) The Office of Personnel Management (OPM) will consider the factors listed below...

  1. 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 Southe...

  2. A Demographic Perspective on Family Change

    Science.gov (United States)

    Bianchi, Suzanne M.

    2014-01-01

    Demographic analysis seeks to understand how individual microlevel decisions about child-bearing, marriage and partnering, geographic mobility, and behaviors that influence health and longevity aggregate to macrolevel population trends and differentials in fertility, mortality and migration. In this review, I first discuss theoretical perspectives—classic demographic transition theory, the perspective of the “second demographic transition,” the spread of developmental idealism—that inform demographers’ understanding of macrolevel population change. Then, I turn to a discussion of the role that demographically informed data collection has played in illuminating family change since the mid-20th century in the United States. Finally, I discuss ways in which demographic theory and data collection might inform future areas of family research, particularly in the area of intergenerational family relationships and new and emerging family forms. PMID:26078785

  3. Socio-demographics and the development of malaria elimination strategies in the low transmission setting.

    Science.gov (United States)

    Chuquiyauri, Raul; Paredes, Maribel; Peñataro, Pablo; Torres, Sonia; Marin, Silvia; Tenorio, Alexander; Brouwer, Kimberly C; Abeles, Shira; Llanos-Cuentas, Alejandro; Gilman, Robert H; Kosek, Margaret; Vinetz, Joseph M

    2012-03-01

    This analysis presents a comprehensive description of malaria burden and risk factors in Peruvian Amazon villages where malaria transmission is hypoendemic. More than 9000 subjects were studied in contrasting village settings within the Department of Loreto, Peru, where most malaria occurs in the country. Plasmodium vivax is responsible for more than 75% of malaria cases; severe disease from any form of malaria is uncommon and death rare. The association between lifetime malaria episodes and individual and household covariates was studied using polychotomous logistic regression analysis, assessing effects on odds of some vs. no lifetime malaria episodes. Malaria morbidity during lifetime was strongly associated with age, logging, farming, travel history, and living with a logger or agriculturist. Select groups of adults, particularly loggers and agriculturists acquire multiple malaria infections in transmission settings outside of the main domicile, and may be mobile human reservoirs by which malaria parasites move within and between micro-regions within malaria endemic settings. For example, such individuals might well be reservoirs of transmission by introducing or reintroducing malaria into their home villages and their own households, depending on vector ecology and the local village setting. Therefore, socio-demographic studies can identify people with the epidemiological characteristic of transmission risk, and these individuals would be prime targets against which to deploy transmission blocking strategies along with insecticide treated bednets and chemoprophylaxis.

  4. Socio-Demographics and the Development of Malaria Elimination Strategies in the Low Transmission Setting

    Science.gov (United States)

    Chuquiyauri, Raul; Paredes, Maribel; Peñataro, Pablo; Torres, Sonia; Marin, Silvia; Tenorio, Alexander; Brouwer, Kimberly C.; Abeles, Shira; Llanos-Cuentas, Alejandro; Gilman, Robert H.; Kosek, Margaret; Vinetz, Joseph M.

    2011-01-01

    This analysis presents a comprehensive description of malaria burden and risk factors in Peruvian Amazon villages where malaria transmission is hypoendemic. More than 9,000 subjects were studied in contrasting village settings within the Department of Loreto, Peru, where most malaria occurs in the country. Plasmodium vivax is responsible for more than 75% of malaria cases; severe disease from any form of malaria is uncommon and death rare. The association between lifetime malaria episodes and individual and household covariates was studied using polychotomous logistic regression analysis, assessing effects on odds of some vs. no lifetime malaria episodes. Malaria morbidity during lifetime was strongly associated with age, logging, farming, travel history, and living with a logger or agriculturist. Select groups of adults, particularly loggers and agriculturists acquire multiple malaria infections in transmission settings outside of the main domicile, and may be mobile human reservoirs by which malaria parasites move within and between micro-regions within malaria endemic settings. For example, such individuals might well be reservoirs of transmission by introducing or reintroducing malaria into their home villages and their own households, depending on vector ecology and the local village setting. Therefore, socio-demographic studies can identify people with the epidemiological characteristic of transmission risk, and these individuals would be prime targets against which to deploy transmission blocking strategies along with insecticide treated bednets and chemoprophylaxis. PMID:22100446

  5. Entangled histories

    Science.gov (United States)

    Cotler, Jordan; Wilczek, Frank

    2016-12-01

    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.

  6. 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.

  7. 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.

  8. Association of parental history of type 2 diabetes with age, lifestyle, anthropometric factors, and clinical severity at type 2 diabetes diagnosis

    DEFF Research Database (Denmark)

    Svensson, Elisabeth; Berencsi, Klara; Sander, Simone;

    2016-01-01

    BACKGROUND: We investigated whether parental history of type 2 diabetes mellitus (T2D) is associated with age, lifestyle, anthropometric factors, and clinical severity at the time of T2D diagnosis. METHODS: We conducted a cross-sectional study based on the Danish Centre for Strategic Research...... in Type 2 Diabetes cohort. We examined the prevalence ratios (PR) of demographic, lifestyle, anthropometric, and clinical factors according to parental history, using Poisson regression adjusting for age and gender. RESULTS: Of 2825 T2D patients, 34% (n = 964) had a parental history of T2D. Parental.......80)], and also tended to be associated with lower beta cell function. In contrast, patients both with and without a parental history had similar occurrence of central obesity [91% vs. 91%], weight gain ≥30 kg since age 20 [52% vs. 53%], and lack of regular physical activity [60% vs. 58%]. Presence of diabetes...

  9. [Demographic projections for Latin American countries prepared by CELADE].

    Science.gov (United States)

    Somoza, J L

    1978-04-01

    The CELADE (Centro Latinoamericano de Demografia) prepares population projections for 20 Latin American countries, a difficult task considering the lack of reliable census data on births, deaths, and other demographic information. Nevertheless, the demographic situation can be estimated by distinguishing two states in the process: estimating past and present population history and formulating hypotheses regarding the future trends of demographic variables. In a typical situation for most Latin American countries, the first stage is the most difficult; results are mostly approximations of the reality. Thus, projections based on these data are unreliable. The present demographic situation in Latin America was analyzed by estimating fertility, mortality and international migration. Fertility rate was calculated based on the following data: number of children born to the female population, number of live births during the year prior to the census classified according to mother's age and number of children registered according to age up to 10 or 15 years of age. Fertility was thus calculated within 5 years prior to the census. Mortality was roughly estimated by calculating the annual death distribution by age. This promoted questions relating to orphans and the relative number of children who survived out of total number of children born to a woman. Little data was available on migration due to lack of registries on annual migration. It was estimated based on the number of people who left the country for 5 years, and promoted questions such as which country is one native of and year of entry into the country. The most important task relating to population projection of Latin America is the improvement of knowledge on fertility, mortality and migration.

  10. amily Planning Brings China Demographic Bonus

    Institute of Scientific and Technical Information of China (English)

    马瀛通

    2007-01-01

    Editorial note Scholars around the world are voicing their criticisms on China’s family planning policy,which,in their opinions,will lead to an unhealthy population structure.This article reviews the concepts of"rich before old"and"negative demographic bonus",and concludes that with regards to some indicators such as dependency ratio and demographic bonus,there exists a discrepancy between calculations and reality.The author believes that China will continue to witness a surge of demographic bonus in the future.

  11. 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...

  12. Turning towards History: Turning towards Utopia

    Science.gov (United States)

    Freeman-Moir, John

    2004-01-01

    Turning towards history--to be contrasted with turning away from history--captures the Marxian sense of education. Marx worked out the elements of a theory of political education in relation to history by equating education with the coincidence of the changing of circumstances and people. This theory received its most comprehensive yet succinct…

  13. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

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

  14. 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, ...

  15. Generalized phase contrast:

    DEFF Research Database (Denmark)

    Glückstad, Jesper; Palima, Darwin

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

  16. 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.

  17. 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...

  18. 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...

  19. Romerrigets historie

    DEFF Research Database (Denmark)

    Christiansen, Erik

    Romerrigets historie fra Roms legendariske grundlæggelse i 753 f.v.t. til Heraklios' tronbestigelse i 610 e.v.t.......Romerrigets historie fra Roms legendariske grundlæggelse i 753 f.v.t. til Heraklios' tronbestigelse i 610 e.v.t....

  20. 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.

  1. Quantum Histories

    CERN Document Server

    Kent, A

    1998-01-01

    There are good motivations for considering some type of quantum histories formalism. Several possible formalisms are known, defined by different definitions of event and by different selection criteria for sets of histories. These formalisms have a natural interpretation, according to which nature somehow chooses one set of histories from among those allowed, and then randomly chooses to realise one history from that set; other interpretations are possible, but their scientific implications are essentially the same. The selection criteria proposed to date are reasonably natural, and certainly raise new questions. For example, the validity of ordering inferences which we normally take for granted --- such as that a particle in one region is necessarily in a larger region containing it --- depends on whether or not our history respects the criterion of ordered consistency, or merely consistency. However, the known selection criteria, including consistency and medium decoherence, are very weak. It is not possibl...

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

    DEFF Research Database (Denmark)

    Abascal, Federico; Corvelo, André; Cruz, Fernando;

    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...

  3. Demographic cycles, cohort size, and earnings.

    Science.gov (United States)

    Berger, M C

    1989-05-01

    This article examines whether position in the demographic cycle is an important factor in determining earnings and earnings growth. Earnings equations for white males are estimated by using March Current Population Survey data. Position in the demographic cycle is captured by including both measures of own cohort size and the size of surrounding cohorts in the estimated earnings equations. Position in the demographic cycle matters. Increases in own cohort size lead to flatter earnings profiles, whereas increases in the size of surrounding cohorts are associated with steeper earnings profiles. The net effect is that those who enter the labor market before or after the peak of the demographic cycle start out with lower earnings but experience faster earnings growth. This pattern is uniform across all schooling groups: high school dropouts, high school graduates, those with some college, and college graduates.

  4. The demographic work of Sir William Wilde.

    Science.gov (United States)

    Froggatt, P

    2016-05-01

    This paper argues that Sir William Wilde was indeed a pioneering demographer. It also describes the unveiling of the plaque commemorating Sir William Wilde at his home, 1, Merrion Square, Dublin on the 28 October 1971.

  5. Demographics and presenting clinical features of childhood ...

    African Journals Online (AJOL)

    Demographics and presenting clinical features of childhood systemic lupus ... and characteristics of children with systemic lupus erythematosus (SLE). ... Rashes were found to be the commonest clinical feature present at the time of diagnosis, ...

  6. 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

  7. Demographic heterogeneity, cohort selection, and population growth

    OpenAIRE

    Bruce E. Kendall; Fox, Gordon A.; Fujiwara, Masami; Nogeire, Theresa M.

    2011-01-01

    Demographic heterogeneity—variation among individuals in survival and reproduction—is ubiquitous in natural populations. Structured population models address heterogeneity due to age, size, or major developmental stages. However, other important sources of demographic heterogeneity, such as genetic variation, spatial heterogeneity in the environment, maternal effects, and differential exposure to stressors, are often not easily measured and hence are modeled as stochasticity. Recent research ...

  8. 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

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

    Science.gov (United States)

    Chen, Jinping; Rossiter, Stephen J; Flanders, Jonathan R; Sun, Yanhong; Hua, Panyu; Miller-Butterworth, Cassandra; Liu, Xusheng; Rajan, Koilmani E; Zhang, Shuyi

    2010-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Jinping Chen

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

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

    NARCIS (Netherlands)

    Potarca, Gina; Mills, Melinda; Lesnard, Laurent

    2013-01-01

    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

  12. Anisotropic Contrast Optical Microscope

    CERN Document Server

    Peev, D; Kananizadeh, N; 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

    2016-01-01

    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. We demonstrate the anisotropic contrast optical microscope by mea...

  13. 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 ...

  14. Compressive Phase Contrast Tomography

    CERN Document Server

    Maia, F R N C; Marchesini, S; Padmore, H A; Parkinson, D Y; Pien, J; Schirotzek, A; Yang, C; 10.1117/12.861946

    2010-01-01

    When x-rays penetrate soft matter, their phase changes more rapidly than their amplitude. In- terference 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 con- trast 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).

  15. Revolution without ideology: demographic transition in East Asia.

    Science.gov (United States)

    Anderson, T D

    1980-01-01

    The acceleration of demographic transition in East Asia is a process of great potential import for the world. The most rapid and large scale transformation of demographic pattern in world history is being accomplished in this region. Demographic processes in other countries and regions have been viewed in the light of past events. Demographic transition has been accepted as a desirable goal, but its realization was believed subject to certain constraints. These include the need to attain high rates of economic growth in order to stimulate the transition and the longer period of time required to accomplish the transition. It was assumed that at least 2 generations would be subject to gradually diminishing rates of increase and slow cultural modification before transition entered its last phase. This interpretation of the preconditions and specific character of demographic transition has been subject to increasing challenge, and recent events in East Asia accentuate such doubts. Most new views begin with the premises that contemporary pretransition societies are not European in culture and the 1970s are not the 1880s. East Asia also differs culturally from other developing areas, including South and Southeast Asia. The most significant regional features are cultural. Demographic transition in the region began after World War 2 and somewhat differently in each East Asian country. The process began first in Japan. The 3rd phase was accomplished rapidly but not as a specific consequence of the modernization process. The end of World War 2 and the spurt in births accompanying military demobilization contributed to a population surge. The cultural factors of practicality, homogeneity, social discipline, and nearly universial literacy were decisive here. Abortion was legalized in 1948 and other forms of birth control were made readily available. Between 1947 and 1957 the birthrate was halved to 17/1000. In Taiwan and South Korea public concern about high rates of

  16. Understanding the contrasting spatial haplotype patterns of malaria-protective β-globin polymorphisms.

    Science.gov (United States)

    Hockham, Carinna; Piel, Frédéric B; Gupta, Sunetra; Penman, Bridget S

    2015-12-01

    The malaria-protective β-globin polymorphisms, sickle-cell (β(S)) and β(0)-thalassaemia, are canonical examples of human adaptation to infectious disease. Occurring on distinct genetic backgrounds, they vary markedly in their patterns of linked genetic variation at the population level, suggesting different evolutionary histories. β(S) is associated with five classical restriction fragment length polymorphism haplotypes that exhibit remarkable specificity in their geographical distributions; by contrast, β(0)-thalassaemia mutations are found on haplotypes whose distributions overlap considerably. Here, we explore why these two polymorphisms display contrasting spatial haplotypic distributions, despite having malaria as a common selective pressure. We present a meta-population genetic model, incorporating individual-based processes, which tracks the evolution of β-globin polymorphisms on different haplotypic backgrounds. Our simulations reveal that, depending on the rate of mutation, a large population size and/or high population growth rate are required for both the β(S)- and the β(0)-thalassaemia-like patterns. However, whilst the β(S)-like pattern is more likely when population subdivision is high, migration low and long-distance migration absent, the opposite is true for β(0)-thalassaemia. Including gene conversion has little effect on the overall probability of each pattern; however, when inter-haplotype fitness variation exists, gene conversion is more likely to have contributed to the diversity of haplotypes actually present in the population. Our findings highlight how the contrasting spatial haplotype patterns exhibited by β(S) and β(0)-thalassaemia may provide important indications as to the evolution of these adaptive alleles and the demographic history of the populations in which they have evolved.

  17. 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)

  18. Pregnancy intention, demographic differences, and psychosocial health.

    Science.gov (United States)

    Maxson, Pamela; Miranda, Marie Lynn

    2011-08-01

    We explore the psychosocial, demographic, and maternal characteristics across wanted, mistimed, and unwanted pregnancies. Data from 1321 women from a prospective cohort study of pregnant women in Durham, NC, are analyzed. Psychosocial correlates were obtained through prenatal surveys; electronic medical records were used to ascertain maternal health and pregnancy outcomes. Sixty-two percent of the women indicated an unintended pregnancy, with 44% (578) mistimed and 18% (245) unwanted. Only 38% of the pregnancies were characterized as wanted. Women with unwanted and with mistimed pregnancies were similar demographically, but they differed significantly on psychosocial profiles and maternal characteristics. Women with mistimed and with wanted pregnancies differed in demographics and psychosocial profiles. Wanted pregnancies had the healthiest, mistimed an intermediate, and unwanted the poorest psychosocial profile. Women with unwanted pregnancies had the highest depression, perceived stress, and negative paternal support scores (ppsychosocial profiles had higher odds of being in the unwanted category. Controlling for psychosocial and demographic variables, perceived stress and positive paternal support remained significant predictors of belonging to the unwanted and mistimed groups. Fully characterizing pregnancy intention and its relationship to psychosocial profiles may provide a basis for identifying women with highest risk during pregnancy and early motherhood. Women with unwanted and mistimed pregnancies may appear similar demographically but are different psychosocially. Women with unwanted pregnancies have multiple risk factors and would benefit from targeted interventions.

  19. 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.

  20. Demographic and affective covariates of pain.

    Science.gov (United States)

    Garron, D C; Leavitt, F

    1979-11-01

    Relationships of four demographic variables and five affective variables to eight attributes of low back pain were investigated in 251 patients by stepwise, multivariate analysis. The demographic variables are age, sex, race, and education. The affective variables are state anxiety, trait anxiety anxiety, hostility, and depression. Seven of the pain variables are from the factorially derived Low Back Pain Questionnaire. The eighth pain variable is a self-estimate of intensity. Relationships among demographic and pain variables are small and unsystematic. Hostility has a small, systematically inverse relation to pain variables, supporting theories relating low back pain to inhibition of anger. Anxiety has a small positive relationship, and depression has no relationship to pain variables. In general, the small relationships indicate that the Low Back Pain Questionnaire provides descriptions of pain that are not confounded by social characteristics or current emotional states of patients.

  1. Robust demographic inference from genomic and SNP data.

    Directory of Open Access Journals (Sweden)

    Laurent Excoffier

    2013-10-01

    Full Text Available 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 ∂a∂i, 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.

  2. Febrile Seizure: Demographic Features and Causative Factors

    OpenAIRE

    2012-01-01

    How to cite this article: Esmaili Gourabi H, Bidabadi E, Cheraghalipour  F, Aarabi  Y, Salamat F. Febrile Seizure: Demographic Features and Causative Factors. Iran J Child Neurol Autumn 2012; 6(4):33-37.Abstract Objective Because of geographical and periodical variation, we prompted to determine the demographic features and causative factors for febrile seizure in Rasht. Materials & Methods In this cross-sectional study, all 6–month- to 6-year-old children with the diagnosis of febrile s...

  3. Polychromatic diffraction contrast tomography

    Energy Technology Data Exchange (ETDEWEB)

    King, A., E-mail: king@synchrotron-soleil.fr [Synchrotron SOLEIL, Gif-sur-Yvette 91192 (France); Reischig, P. [Xnovo Technology ApS, 4600 Køge (Denmark); Department of Materials Science and Engineering, Delft University of Technology, Delft 2628 CD (Netherlands); Adrien, J. [MATEIS, INSA de Lyon, Villeurbanne 69621 (France); Peetermans, S. [Paul Scherrer Institut, CH-5232 Villigen (Switzerland); Ludwig, W. [MATEIS, INSA de Lyon, Villeurbanne 69621 (France); European Synchrotron Radiation Facility, Grenoble 38043 (France)

    2014-11-15

    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.

  4. Contrastive topics decomposed

    Directory of Open Access Journals (Sweden)

    Michael Wagner

    2012-12-01

    Full Text Available The analysis of contrastive topics introduced in Büring 1997b and further developed in Büring 2003 relies on distinguishing two types of constituents that introduce alternatives: the sentence focus, which is marked by a FOC feature, and the contrastive topic, which is marked by a CT feature. A non-compositional rule of interpretation that refers to these features is used to derive a topic semantic value, a nested set of sets of propositions. This paper presents evidence for a correlation between the restrictive syntax of nested focus operators and the syntax of contrastive topics, a correlation which is unexpected under this analysis. A compositional analysis is proposed that only makes use of the flatter focus semantic values introduced by focus operators. The analysis aims at integrating insights from the original analysis while at the same time capturing the observed syntactic restrictions. http://dx.doi.org/10.3765/sp.5.8 BibTeX info

  5. IUD Expulsion and its Socio-demographic Determinants in China

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Objective To identify the determinant of the occurrence of IUD expulsionMaterials & Methods Based on 25 733 IUD uses from the Chinese Two-per-Thou-sand Fertility Survey data, this study examines the patterns and differentials of IUDexpulsion rate by characteristics of women, and identifies the socio-demographic deter-minants of IUD expulsion. A Life Table method was used to calculate the cumulativeexpulsion rate and a random-effects discrete-time survival model was employed to as-sess the impact of potential determinants simultaneously on the risk of expelling anIUD.Results Three major findings are observed in this study. First, IUD expulsion wasthe second main reason, after pregnancy during IUD use, for IUD discontinuationduring the first four years of IUD insertion; the expulsion rates were 6. 4%, 9. 1%,10. 8 %, and 12. 0% at 12, 24, 36and 48months, respectively. Second, there was aclustering of IUD expulsion: some women experienced repeated IUD expulsions.Third, some socio-demographic characteristics and fertility history were associatedwith the occurrence of IUD expulsion. In particular, the expulsion rate was highamong young women, among those with two or more children and among those livingin rural areas.Conclusion The above mentioned factors shoald be addressed in order to decrease theIUD expulsion rate and enhance the reprocluctive he alth of women.

  6. Demographic analysis from summaries of an age-structured population

    Science.gov (United States)

    Link, William A.; Royle, J. Andrew; Hatfield, Jeff S.

    2003-01-01

    Demographic analyses of age-structured populations typically rely on life history data for individuals, or when individual animals are not identified, on information about the numbers of individuals in each age class through time. While it is usually difficult to determine the age class of a randomly encountered individual, it is often the case that the individual can be readily and reliably assigned to one of a set of age classes. For example, it is often possible to distinguish first-year from older birds. In such cases, the population age structure can be regarded as a latent variable governed by a process prior, and the data as summaries of this latent structure. In this article, we consider the problem of uncovering the latent structure and estimating process parameters from summaries of age class information. We present a demographic analysis for the critically endangered migratory population of whooping cranes (Grus americana), based only on counts of first-year birds and of older birds. We estimate age and year-specific survival rates. We address the controversial issue of whether management action on the breeding grounds has influenced recruitment, relating recruitment rates to the number of seventh-year and older birds, and examining the pattern of variation through time in this rate.

  7. Socio-Demographic and Cognitive Determinants of Breast Cancer Screening

    Directory of Open Access Journals (Sweden)

    Mehdi Mirzaei-Alavijeh

    2016-12-01

    Full Text Available Breast cancer is one of the causes of cancer death among women. In developed countries, one out of every nine women is diagnosed with this type of cancer. The purpose of this study was to determine the socio-demographic and cognitive determinants related to breast cancer screening among Iranian women’s based on the protection motivation theory (PMT. This cross-sectional study was conducted among 385 women’s aged 35 to 50 years old referred to health centers in Abadan city, the southwest of Iran, during 2016. Participants filled out a self-administered questionnaire. Data were analyzed by SPSS version 21 using bivariate correlation, and logistic regression statistical tests at 95% significant level. The mean age of respondents was 39.12 years [95% CI: 38.72, 39.53], ranged from 35 to 50 years. Almost 7.5% and 19.1% of the participants had mammography and self-breast examination during last year. Age, education and positive history of breast cancer among family were the best socio-demographic predictive factors of breast cancer screening. Also among theoretical constructs of PMT, perceived severity and self-efficacy were the best predictors on breast cancer screening. Based on our result, it seems that designing and implementation of educational programs to increase seriousness about side effect of breast cancer and increase self-efficacy toward breast cancer screening behavior may be usefulness of the results in order to prevent of breast cancer.

  8. 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....

  9. Linjefaget historie

    DEFF Research Database (Denmark)

    Rasch-Christensen, Andreas

    Afhandlingen er en undersøgelse af linjefaget historie ved læreruddannelsen. Med fokus på subjektperspektivet peger afhandlingen på en række afgørende udviklingsperspektiver for læreruddannelsen, uddannelsen af historielærere og folkeskolens historieundervisning.......Afhandlingen er en undersøgelse af linjefaget historie ved læreruddannelsen. Med fokus på subjektperspektivet peger afhandlingen på en række afgørende udviklingsperspektiver for læreruddannelsen, uddannelsen af historielærere og folkeskolens historieundervisning....

  10. 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....

  11. Environmental history

    DEFF Research Database (Denmark)

    Pawson, Eric; Christensen, Andreas Aagaard

    2016-01-01

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

  12. 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.

  13. 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 μm2 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

  14. Demographic Costs Associated with Differences in Habitat Space Occupancy.

    Science.gov (United States)

    Williams, Kelly A; Miles, Donald B

    2016-01-01

    Delimiting the habitat characteristics describing the environmental conditions required by a species has become a critical tool for predicting organismal responses to environmental change. Grinnell emphasized the effects of environmental factors on the ability of a population to maintain a positive growth rate, yet few studies have included demographic or reproductive data in analyses of the Grinnellian niche. Identifying differences in habitat exploitation patterns in response to structural variation in the environment presents an incomplete description of the ability of species to adapt to changing habitats if demographic traits are not included. We estimated the vegetation characteristics used by individuals within a population of hooded warblers (Setophaga citrina) across a spatial transect that includes three structurally different forest habitats. We predicted individuals should select similar structural characteristics within each habitat and have similar reproductive success across sample sites. In the two years post burn, adults were present but no young fledged indicating the habitat requirements necessary for reproduction were absent in this habitat. We found significant differences in habitat space occupied by individuals in unaltered and harvested habitats. Nesting habitats used by female warblers differed from available habitat. Fledging success was lower in the harvested habitat 10 to 12 years post-harvest. In the harvested habitat, fledging success was greater on mesic slopes but decreased along a habitat gradient to xeric ridgetops, suggesting compensation in habitat use does not ameliorate fitness costs. In contrast, there was no difference in the number of fledged young along this gradient in the unaltered habitat. Based solely on occupancy data, traditional ecological niche models would incorrectly conclude the environmental characteristics found across the three forested habitats are included in the Grinnellian niche of the hooded warbler

  15. Cultural history as polyphonic history

    Directory of Open Access Journals (Sweden)

    Burke, Peter

    2010-06-01

    Full Text Available This texts offers a reflection on the origins and actual development of the field of cultural history through a comparison with the term that has served as title for this seminar: “polyphonic history”. The author provides an overview of the themes that have structured the seminar (the history of representations, the history of the body and the cultural history of science with the aim of making explicit and clarifying this plurality of voices in the field of history as well as its pervasiveness in other research areas.

    En este texto se ofrece una reflexión sobre el origen y actual desarrollo del campo de la historia cultural a través de una comparación con el término que ha dado título a este seminario: “historia polifónica”. El autor propone un recorrido por las áreas temáticas que han conformado la estructura del seminario (la historia de las representaciones, la historia del cuerpo y la historia cultural de la ciencia con el objeto de explicitar y explicar esta pluralidad de voces en el campo de la historia, así como su repercusión en otras áreas del conocimiento.

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

    Science.gov (United States)

    Schneider, A W; Fichtner, J

    2014-08-01

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

  17. 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.

  18. Why History?

    Science.gov (United States)

    Duffy, Robert E.

    1988-01-01

    Examines the way in which studying history contributes to intellectual development. Identifies five mental attributes it enhances: perspective--gained from placing people, events, institutions against larger background; encounter--confronting great ideas, personalities, etc.; relativism in a pluralistic world--developed from immersion in other…

  19. Bulletproof History.

    Science.gov (United States)

    Roy, R. H.

    1994-01-01

    Asserts that the writers and producers of the television documentary, "The Valour and the Horror," provided a false impression of an event to fit preconceived and erroneous interpretations of history. Points out specific examples of inaccurate historical presentations and provides contradictory historical interpretations. (CFR)

  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. Potted history

    NARCIS (Netherlands)

    Van Dijk, T.

    2010-01-01

    The Jordan Valley was once populated by a people, now almost forgotten by historians, with whom the pharaoh of Egypt sought favour. That is the conclusion reached by Niels Groot, the first researcher to take a PhD at the Delft-Leiden Centre for Archaeology, Art History and Science.

  2. Environmental versus demographic variability in stochastic predator-prey models

    Science.gov (United States)

    Dobramysl, U.; Täuber, U. C.

    2013-10-01

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

  3. Life Potential as a Basic Demographic Indicator

    Science.gov (United States)

    Goerlich, Francisco J.; Soler, Angel

    2013-01-01

    This paper proposes an indicator that integrates life expectancy with the demographic structure of the population for a given society. By doing this, we have a simple indicator of mortality and aging combined, which could be very useful for developed societies. As is widely known, life expectancy at birth is independent of the demographic…

  4. Demographic development in ASEAN: a comparative overview.

    Science.gov (United States)

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

    1981-01-01

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

  5. Second demographic transition de-blocked?

    Directory of Open Access Journals (Sweden)

    Bobić Mirjana

    2011-01-01

    Full Text Available The text is re-examining the previously established dilemma related to whether Serbia (without Kosovo and Metohija is the country of second demographic transition, i.e.: has the transition been de-blocked, under the assumption that this is a worldwide historical process of transformation of industrialized countries. The last thesis, around which there exists a lot of controversy in the contemporary population theory, is however not dealt with in detail; to the contrary, it is used as the general theoretical framework for the exploration of the most recent tendencies in the transformation of nuptiality and fertility regime in Serbia, as well as in the western and countries in post-socialist transformation. Special attention is given to the ideational changes, more precisely to the specific features of the value profile of the Serbian population, which is one of the most important determinants of the societal framework, that acts in the back of the afore mentioned aggregate demographic indicators. Finally, the hypothesis is posed (which should be further investigated by means of in-depth research and complementary approach that the speeding-up of the second demographic transition and intensification of the individualisation not only of the partnership but of the parenthood as well, accompanied with the rise of living standard and social support to balancing work and family, would have produced important emancipating and, concomitantly, positive socioeconomic and demographic effects.

  6. 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…

  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. Economic and Demographic Predictors of Inclusive Education

    Science.gov (United States)

    Cosier, Meghan E.; Causton-Theoharis, Julie

    2011-01-01

    This study investigated economic and demographic predictors of levels of inclusion of students with disabilities in 129 school districts. Multiple regression analysis was utilized to address the following research questions: (a) Is there a relationship between economic factors and percentage of highly included students with disabilities in general…

  9. Demographic Group Differences in Adolescents' Time Attitudes

    Science.gov (United States)

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

    2013-01-01

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

  10. The Macroeconomic Dynamics of Demographic Shocks

    NARCIS (Netherlands)

    Heijdra, B.J.; Ligthart, J.E.

    2004-01-01

    The paper employs an extended Yaari-Blanchard model of overlapping generations to study how the macroeconomy is affected over time by various demographic changes.It is shown that a proportional decline in fertility and death rates has qualitatively similar effects to capital income subsidies; both p

  11. High Contrast CRT.

    Science.gov (United States)

    1979-08-01

    r AD’ A076 235 WATKINS—JOHNSON Co SCOTYS VAL LEY CA F/S 9/5 N HIGH CONTRAST CRT.CU) AUG 79 6 A HOLNQUIST DAABO7—77—C—263 9 UNCLASSIFIED DEL.ET—TR—77...Air Force Systems Command A t t n : l) l . CA 2w) U I f iee ’ of \\ iva l Re ’~.ea r ch Andr ews AFI4 ( • ~~ii 4.~7 001 Washington , l ) .C. 20331

  12. Quality of demographic data in GGS Wave 1

    Directory of Open Access Journals (Sweden)

    Jorik Vergauwen

    2015-03-01

    Full Text Available Background: A key feature of the Generations & Gender Programme (GGP is that longitudinal micro-data from the Generations and Gender Surveys (GGS can be combined with indicators from the Contextual Database (CDB that provide information on the macro-level context in which people live. This allows researchers to consider the impact of socio-cultural, economic, and policy contexts on changing demographic behaviour since the 1970s. The validity of longitudinal analyses combining individual-level and contextual data depends, however, on whether the micro-data give a correct account of demographic trends after 1970. Objective: This article provides information on the quality of retrospective longitudinal data on first marriage and fertility in the first wave of the GGS. Methods: Using the union and fertility histories recorded in the GGS, we compare period indicators of women's nuptiality and fertility behaviour for the period 1970-2005 and cohort indicators of nuptiality and fertility for women born after 1925 to population statistics. Results: Results suggest that, in general, period indicators estimated retrospectively from the GGS are fairly accurate from the 1970s onwards, allowing exceptions for specific indicators in specific countries. Cohort indicators, however, were found to be less accurate for cohorts born before 1945, suggesting caution when using the GGS to study patterns of union and family formation in these older cohorts. Conclusions: The assessment of the validity of demographic data in the GGS provides country-specific information on time periods and birth cohorts for which GGS estimates deviate from population statistics. Researchers may use this information to decide on the observation period or cohorts to include in their analysis, or use the results as a starting point for a more detailed analysis of item nonresponse in union and fertility histories, which may further improve the quality of GGS estimates, particularly for these

  13. Investigation of the demographic and selective forces shaping the nucleotide diversity of genes involved in nod factor signaling in Medicago truncatula.

    Science.gov (United States)

    De Mita, Stéphane; Ronfort, Joëlle; McKhann, Heather I; Poncet, Charles; El Malki, Redouane; Bataillon, Thomas

    2007-12-01

    Symbiotic nitrogen-fixing rhizobia are able to trigger root deformation in their Fabaceae host plants, allowing their intracellular accommodation. They do so by delivering molecules called Nod factors. We analyzed the patterns of nucleotide polymorphism of five genes controlling early Nod factor perception and signaling in the Fabaceae Medicago truncatula to understand the selective forces shaping the evolution of these genes. We used 30 M. truncatula genotypes sampled in a genetically homogeneous region of the species distribution range. We first sequenced 24 independent loci and detected a genomewide departure from the hypothesis of neutrality and demographic equilibrium that suggests a population expansion. These data were used to estimate parameters of a simple demographic model incorporating population expansion. The selective neutrality of genes controlling Nod factor perception was then examined using a combination of two complementary neutrality tests, Tajima's D and Fay and Wu's standardized H. The joint distribution of D and H expected under neutrality was obtained under the fitted population expansion model. Only the gene DMI1, which is expected to regulate the downstream signal, shows a pattern consistent with a putative selective event. In contrast, the receptor-encoding genes NFP and NORK show no significant signatures of selection. Among the genes that we analyzed, only DMI1 should be viewed as a candidate for adaptation in the recent history of M. truncatula.

  14. Visual function of Egyptian children with low vision and the demographic determinants

    Directory of Open Access Journals (Sweden)

    El Byoumi Boshra

    2010-01-01

    Full Text Available Aims: To determine whether the LV Prasad-Functional Vision Questionnaire (LVP-FVQ could be used to assess self-reported visual function and quality of visual life in Egyptian school aged children. Materials and Methods: The LVP-FVQ was used to assess the quality of visual function in school-age children. All subjects were students at the time of assessment. Subjects underwent a visual function assessment that included distance and near visual acuity, contrast sensitivity, color vision and visual field examination where possible. Data analysis were for both descriptive and inference statistics. A P < 0.05 was considered statistically significant. Results: Fifty children aged 11.28 ± 3.5 years (range, 5 years to 18 years with moderate-to-severe visual impairment most of their lives were enrolled. Twenty-two subjects (44% had albinism, 18 (36% subjects had hereditary retinal dystrophy, 6 (12% subjects had cone dystrophy, 2 (4% subjects had bilateral amblyopia and 2 (4% subjects had congenital coloboma without other disabilities. The four most difficult tasks were related to the following daily activities alluded to in the questionnaire such as reading a textbook at arms length, copying from the blackboard, seeing somebody across the road and identifying colors. There was no statistically significant association between the demographic variables and the level of visual functioning, sex, age, type of school, family history or consanguinity (P > 0.05 for all variables. Conclusion: LVP-FVQ can be used to screen Egyptian children with visual impairment. Input and integration of the parents and the school teachers to evaluate the child s behavior at home and the school is essential to developing a balanced questionnaire.

  15. 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...

  16. Sommerferiens historie

    DEFF Research Database (Denmark)

    Lützen, Karin

    2011-01-01

    favourite ways for com- mon people to spend their holidays, and with the introduction of holiday pay in the 1930s almost everybody could take a couple of weeks off work in the sum- mer. With the introduction of charter tourism many people went off to Southern Europe to spend their holidays on the same...... pattern. Finally, the history of the special holiday camps is told, which were established by American Jews because they were excluded from many hotels....

  17. What is a polycentric history of psychology?

    Directory of Open Access Journals (Sweden)

    Adrian Charles Brock

    2014-09-01

    Full Text Available The term, "polycentric history of psychology" was originally used by Kurt Danziger and it has since been adopted by other historians of psychology. The article provides an introduction to this approach. The trend towards the internationalisation of psychology has led to the history of American psychology being supplemented by other local histories. Polycentric history is contrasted this approach. It is concerned with the interrelationships between centres and not individual centres considered in isolation. The article concludes with some examples of history that has been written from a polycentric perspective.

  18. Phase Contrast Imaging

    DEFF Research Database (Denmark)

    1996-01-01

    with a simple one-to-one mapping between resolution elements of a spatial phase modulator and resolution elements of the generated intensity pattern is provided. According to the invention a method is provided for synthesizing an intensity pattern with low loss of electromagnetic energy, comprising spatial...... modulation of electromagnetic radiation with a spatial phase mask for modulation of the phase of the incident eletromagnetic radiation by phasor values of individual resolution elements of the spatial phase mask, each phasor value being determined in such a way that the values of the Fourier transformed......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...

  19. Demographic variables in coal miners’ safety attitude

    Science.gov (United States)

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

    2017-03-01

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

  20. Complexity and demographic explanations of cumulative culture.

    Directory of Open Access Journals (Sweden)

    Adrien Querbes

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

  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.......This paper analyzes the strong comovement between real stock and nominal bond yields at generational (low) frequencies. Life-cycle patterns in savings behavior in an overlapping generations model with cash-in-advance constraints explain this persistent comovement between financial yields. We argue...

  2. The AAVSO 2011 Demographic and Background Survey

    CERN Document Server

    Price, C Aaron

    2012-01-01

    In 2011, the AAVSO conducted a survey of 615 people who are or were recently active in the 101-year old 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 ...

  3. 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.......This paper analyzes the strong comovement between real stock and nominal bond yields at generational (low) frequencies. Life-cycle patterns in savings behavior in an overlapping generations model with cash-in-advance constraints explain this persistent comovement between financial yields. We argue...

  4. New Approaches to Demographic Data Collection

    Science.gov (United States)

    Treiman, Donald J.; Lu, Yao; Qi, Yaqiang

    2013-01-01

    As population scientists have expanded the range of topics they study, increasingly considering the interrelationship between population phenomena and social, economic, and health conditions, they have expanded the kinds of data collected and have brought to bear new data collection techniques and procedures, often borrowed from other fields. These new approaches to demographic data collection are the concern of this essay. We consider three main topics: new developments in sampling procedures; new developments in fieldwork procedures; and new developments in the kind of information collected in demographic and social surveys. We conclude with some comments on data sharing in the social research community and a list of major Chinese surveys publicly available to researchers. Where possible we illustrate our points with Chinese examples. PMID:23844330

  5. 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.

  6. Work history and U.S. elders' transitions into poverty.

    Science.gov (United States)

    McLaughlin, D K; Jensen, L

    2000-08-01

    Poverty risks among elders are shaped in critical ways by their work history, demographic characteristics, current marital status, and residential context. Using 25 years of data from the Panel Study of Income Dynamics, we combined past occupation and work history of elders and their spouses with information on current marital status and residence to estimate discrete time event history models of first transitions into poverty after reaching age 55. Education, work history, and preretirement wages contributed to men's and some women's probability of becoming poor. Work history remained an important predictor of transitions into poverty, even after controlling for preretirement wages and human capital. Metropolitan residence was associated with a lower probability of making transitions into poverty. This residential difference was not appreciably attenuated in three of four elderly subgroups after measures of work history, preretirement wages, current life events, and demographic characteristics of the elders were included in the models.

  7. The demographic cycle and optimal schooling choices.

    Science.gov (United States)

    Jeon, B P; Berger, M C

    1996-10-01

    A model is developed that enables the authors to estimate the effects of demographic cycles on both earnings and schooling. The model is tested using data from the 1991 Korean Occupational Wage Survey. The results indicate that cohorts following large birth cohorts in the cycle choose relatively less formal schooling compared to pre-peak cohorts, and that post-peak cohorts also have lower incomes. This result concerning South Korea is consistent with findings from previous studies concerning the United States.

  8. Regions of Demographic Dynamism in Haryana

    OpenAIRE

    Sanjeev Goel

    2014-01-01

    There are different types of population structures in different parts of the world, the nature of demographic challenges also differ accordingly. The developed countries like USA, Canada, Japan, Australia and many European countries face a problem of slow or even negative population growth. The main concern of the government in these countries remains on population ageing, decline in working force and increasing dependency ratio. The developing countries like India, Pakistan, Bangladesh and L...

  9. DEMOGRAPHIC PREDICTORS WITHIN LOCAL PUBLIC ADMINISTRATION

    Directory of Open Access Journals (Sweden)

    Bente Florina Maria

    2014-12-01

    Design/methodology/approach- Using a quantitative methodological approach, a survey based on SERVQUAL instrument was applied in order to evaluate local public communication. Data from a sample of 380 citizens within Western Romanian were analyzed. Specific demographic predictors that can influence citizens' satisfaction regarding the quality of communication are analyzed. Findings-By analyzing data it was possible to determine citizen satisfaction and to assess its relationship with different demographic characteristics. The results illustrate that gender does not significantly affect satisfaction, instead age, marital status, residence location (urban versus rural, income, education and occupational status of the respondents significantly affect satisfaction regarding local public communication. In addition, the findings confirm a relationship between the citizens' satisfaction and the age, income, education and occupational status of the respondents. Research limitations/implications- Owing to the budget and time limits, only a one-shot survey was conducted, therefore the comparison between “before” and “after” analysis could not be performed. In addition, further research should investigate the local public communication within national contexts. Practical implications -The adapted SERVQUAL scale may be used by institution managers to objectively assess communication performance and local authority service quality. Originality/value- There continues to be a lack of research regarding the communication process within local public administration and the effect of demographic predictors of communication satisfaction. This paper examines both the perceptions and the expectations of citizens regarding public communication. The results offer insights into residence location, age, income, education and occupational status effects on evaluations of communication satisfaction. Finally, the study contributes to studies of perceived service quality by bearing out

  10. 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...

  11. Demographic Pressure in the European Union

    OpenAIRE

    Peeters, Marga; Groot, Loek

    2012-01-01

    On top of the sovereign debt crisis in the European Union, demographic change is exerting enormous pressure on public finances. We analyse four policy options: lowering pension benefits, increasing labour market participation of the native population, immigration and participation of older people. Our results show that the most publically indebted EU economies face the highest increases in public spending on the retiring baby boom generations over the coming decades. Fortunately for these eco...

  12. Mortality versus Morbidity in the Demographic Transition

    OpenAIRE

    Aksan, Anna-Maria; Chakraborty, Shankha

    2014-01-01

    The link between the mortality and epidemiological transitions is used to identify the effect of the former on the fertility transition: a mortality transition that is not accompanied by improving morbidity causes slower demographic and economic change. In a model where children may die from infectious disease, childhood health affects human capital and noninfectious-disease-related adult mortality. When child mortality falls from lower prevalence, as it did in western Europe, labor productiv...

  13. Evolving demographics of advanced dental education.

    Science.gov (United States)

    Waldman, H Barry; Perlman, Steven P; Cinotti, Debra A

    2009-01-01

    The numbers of dental school graduates and students enrolled in post graduate programs have increased. Decreases are noted in the enrollment in Periodontics and Prosthodontics programs and a marked increase in the enrollment in Pediatric Dentistry programs. A review of these changes, by gender and race/ethnicity provides an overview of the future demographics of the profession. Some concerns regarding the future are considered.

  14. [[Demographic characteristics of "business bachelors" in Japan

    Science.gov (United States)

    Yamamoto, C

    1987-01-01

    The demographic characteristics of those obliged to live away from their families because of the distance between their normal homes and places of work or education in Japan are described. Data are from a variety of official and other sources. The author notes that such persons are generally male. Factors affecting the growth of this phenomenon in Japan are the concept of lifetime employment with the same company and the popularity of sending children away to school.

  15. Entropy Based Modelling for Estimating Demographic Trends.

    Directory of Open Access Journals (Sweden)

    Guoqi Li

    Full Text Available In this paper, an entropy-based method is proposed to forecast the demographical changes of countries. We formulate the estimation of future demographical profiles as a constrained optimization problem, anchored on the empirically validated assumption that the entropy of age distribution is increasing in time. The procedure of the proposed method involves three stages, namely: 1 Prediction of the age distribution of a country's population based on an "age-structured population model"; 2 Estimation the age distribution of each individual household size with an entropy-based formulation based on an "individual household size model"; and 3 Estimation the number of each household size based on a "total household size model". The last stage is achieved by projecting the age distribution of the country's population (obtained in stage 1 onto the age distributions of individual household sizes (obtained in stage 2. The effectiveness of the proposed method is demonstrated by feeding real world data, and it is general and versatile enough to be extended to other time dependent demographic variables.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. The Relationship between Demographic Factors and Substance Craving Among Drug-Dependents

    OpenAIRE

    F PoorSeyedMousaiee; V. Mousavi; M Kafi

    2015-01-01

    Objective: This study was conducted with the aim of examining the role of demographic factors such as age, marital status, education degree, the age of initiating addiction, duration of addiction, monthly cost of drug use, and an incarceration history in the intensity of addicts’ craving for substance use. Method: In this descriptive and cross-sectional study, 195 male addicts, after being interviewed, were selected as the participants of the study via convenience sampling method. They consti...

  1. Global History: Opportunities, Dangers, Recent Trends

    OpenAIRE

    Kocka, Jürgen

    2012-01-01

    In contrast to national historical approaches, global history responds to the cultural and intellectual needs of communities, societies and cultures are increasingly interconnected. Global history is an appropriate way of looking to “our past”, in an era of accelerated globalization, helping to “de-provincialize” the discipline. For historians of Europe, global history approaches offer a useful ground for embedding, relativizing and enriching their views and perspectives, even when they conti...

  2. Uncovering History for Future History Teachers

    Science.gov (United States)

    Fischer, Fritz

    2010-01-01

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

  3. Ildens historier

    DEFF Research Database (Denmark)

    Lassen, Henrik Roesgaard

    In December 2012 a manuscript entitled "Tællelyset" ['The Tallow Candle'] was discovered in an archive. The story was subsequently presented to the world as Hans Christian Andersen's first fairy tale and rather bombastically celebrated as such. In this book it is demonstrated that the text cannot...... from a point-by-point tracing of 'the origins and history' of Hans Christian Andersen's famous fairy tales. Where did the come from? How did they become the iconic texts that we know today? On this background it becomes quite clear that "Tællelyset" is a modern pastiche and not a genuine Hans Christian...... Andersen fairy tale....

  4. Demographic Transformations of the Russian Regional Space

    Directory of Open Access Journals (Sweden)

    Elena Viktorovna Kurushina

    2015-07-01

    Full Text Available The paper considers the transformations of the quantitative components of human capital, which is the main driver of economic growth in the material, institutional and mental space. According to the author’s concept of stratified space, the processes of self-reproduction and self-renewal of a system are carried out in the material space. This can be determined by the indicators of fertility, mortality and migration in the demographic subsystem. The process of self-regulation of a system on the basis of legislative acts and behavior patterns is carried out in the institutional space. Institutional transformations are also manifested in the implementation of federal target programs for socio-economic development, affecting the state of the demographic subsystem. The processes of self-reflection, self-determination and self-development are carried out in the mental space. Mental transformations in the demographic subsystem are manifested in the change of value orientations. In accordance with the system of values that are conceptualized in modern development strategies the authors define the following models of Man: Economic Man, Socio-Economic Man (who lives in agglomeration centers and at the periphery, Socio-Natural Man (Environmental Man and Householder Man and Innovative Man. Demographic shifts are investigated in 83 Russian regions on the determinants of birth rate and mortality. The analyzed period of transformation covers 2005 and 2012. Methods of matrix analysis are used to visualize the process of demographic shifts. The assessment of transformation of the stratified regional space spheres is given on the basis of the multifactor models of the population natural growth rate. The paper reveals the reduction in the level and variation of mortality rate, the increasing importance and differentiation of regions according to fertility rate, and the effectiveness of introducing the institution of maternity capital from a perspective of the

  5. Predicting Neck Abscess with Contrast-Enhanced Computed Tomography

    OpenAIRE

    2014-01-01

    Neck abscesses are difficult to diagnose and treat. Currently, contrast-enhanced computed tomography (CECT) is the imaging modality of choice. The study aims to determine the predictive value of CECT findings in diagnosing neck abscess, causes of neck abscess and the most common neck space involved in the local population. 84 consecutive patients clinically suspected to have neck abscess who underwent CECT and surgical confirmation of pus were included. Demographic and clinical data were reco...

  6. 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

    2017-02-16

    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.

  7. Demographic Processes in the Southern Part of the Hungarian – Romanian Border

    Directory of Open Access Journals (Sweden)

    EGON NAGY

    2012-01-01

    Full Text Available This paper is a demographic comparative study of two neighboring regions along the southern part of the Romanian-Hungarian border region, which serves as a fundament for further analyses concerning the verification of cohesion between the two parts of the border. We have concluded our study with the statement that in spite of its traditionally low population increase, the Romanian Timiş and Arad counties have a more advantageous demographical condition than the neighboring Hungarian Békés and Csongrád counties, which can be described as having a generalized demographical decline. Though in Romania the Banat region for many decades is classified as a crisis-zone from a demographical point of view, it can show off an impressive attractiveness in terms of inner-migration in contrast to its Hungarian neighbors. In contrast with the northern part of the Romanian-Hungarian border, in this region the border strip does not overlap with a socio-economic periphery, because this phenomenon is more scattered in space.

  8. Demographics and Angiographic Findings in Patients under 35 Years of Age with Acute ST Elevation Myocardial Infarction

    Directory of Open Access Journals (Sweden)

    Ali Abbasi

    2011-05-01

    Full Text Available Background: ST-elevation myocardial infarction (STEMI is a major cause of cardiovascular mortality worldwide.There are differences between very young patients with STEMI and their older counterparts. This study investigates the demographics and clinical findings in very young patients with STEMI.Methods: Through a review of the angiography registry, 108 patients aged ≤ 35 years (Group I were compared with 5544 patients aged > 35 years (Group II who underwent coronary angiography after STEMI.Results: Group I patients were more likely to be male (92.6%, smokers, and have a family history of cardiovascular diseases (34.6%. The prevalence of diabetes, dyslipidemia, and hypertension was higher in the old patients. Triglyceride and hemoglobin were significantly higher in Group I. Normal coronary angiogram was reported in 18.5% of the young patients, and in 2.1% of the older patients. The prevalence of single-vessel and multi-vessel coronary artery disease was similar in the two groups (34.3% vs. 35.2%. The younger subjects were more commonly candidates for medical treatmentand percutaneous coronary intervention (PCI (84.2%, while coronary artery bypass grafting (CABG was considered for the 39.5% of their older counterparts.Conclusion: In the young adults with STEMI, male gender, smoking, family history, and high triglyceride level were moreoften observed. A considerable proportion of the young patients presented with multi-vessel coronary disease. PCI or medicaltreatment was the preferred treatment in the younger patients; in contrast to their older counterparts, in whom CABG was more commonly chosen for revascularization.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-11-01

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

  10. Professionals and Power Vacuums on Demographic Change

    DEFF Research Database (Denmark)

    Seabrooke, Leonard; Tsingou, Eleni

    Aging populations across advanced industrialized countries are expected to have a great impact on a range of socio-economic policies, ranging from welfare and pensions provision to industrial, labor market and financial policies. While populations are aging there has also been a drop in birth rates....... 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...

  11. Demographic and Clinical Characteristics of People with Intellectual Disabilities with and without Substance Abuse Disorders in a Medicaid Population

    Science.gov (United States)

    Slayter, Elspeth Maclean

    2010-01-01

    Little is known about the demographic and clinical characteristics of people with intellectual disabilities and substance abuse problems. Drawing on health care billing claims for people with Medicaid coverage aged 12-99 years, the characteristics of people with intellectual disability and a history of substance abuse (N = 9,484) were explored and…

  12. THE PROCESS AND EFFECTS OF DEMOGRAPHIC TRANSITION IN PENANG, MALAYSIA

    National Research Council Canada - National Science Library

    Usman Haji Yaakob; Nik Norliati Fitri Md Nor

    2013-01-01

      This article describes the demographic transition in Penang, Malaysia based on the demographic transition theory, which explains the decline of birth and death rates in European countries during the 18th century...

  13. The association of demographic variables and dietary habits on ...

    African Journals Online (AJOL)

    The association of demographic variables and dietary habits on body mass ... socio-demographic variables, weight, height, frequency of physical activity, and food ... in Korea should focus on reducing the intake of meat and high energy foods.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. Demographic Characteristics of World Class Jamaican Sprinters

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    Rachael Irving

    2013-01-01

    Full Text Available The dominance of Jamaican sprinters in international meets remains largely unexplained. Proposed explanations include demographics and favorable physiological characteristics. The aim of this study was to analyze the demographic characteristics of world class Jamaican sprinters. Questionnaires administered to 120 members of the Jamaican national team and 125 controls elicited information on place of birth, language, ethnicity, and distance and method of travel to school. Athletes were divided into three groups based on athletic disciplines: sprint (s: 100–400 m; n=80, jump and throw (j/t: jump and throw; n=25 and, middle distance (md: 800–3000 m; n=15. Frequency differences between groups were assessed using chi-square tests. Regional or county distribution of sprint differed from that of middle distance (P<0.001 but not from that of jump and throw athletes (P=0.24 and that of controls (P=0.59. Sprint athletes predominately originated from the Surrey county (s = 46%, j/t = 37%, md = 17, C = 53%, whilst middle distance athletes exhibited excess from the Middlesex county (md = 60%. The language distribution of all groups showed uniformity with a predominance of English. A higher proportion of middle distance and jump and throw athletes walked to school (md = 80%, j/t = 52%, s = 10%, and C = 12% and travelled greater distances to school. In conclusion, Jamaica’s success in sprinting may be related to environmental and social factors.

  19. 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.

  20. 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

  1. The Future of History and History Teaching.

    Science.gov (United States)

    Commager, Henry Steele

    1983-01-01

    Technical history, a quantitative record of history strengthened by new techniques in mathematics, computer science, and other fields has advantages over former approaches to history--history as philosophy and historical theology. For example, it makes available more source materials. However, it has drawbacks, e.g., it directs research to highly…

  2. The Future of History and History Teaching.

    Science.gov (United States)

    Commager, Henry Steele

    1983-01-01

    Technical history, a quantitative record of history strengthened by new techniques in mathematics, computer science, and other fields has advantages over former approaches to history--history as philosophy and historical theology. For example, it makes available more source materials. However, it has drawbacks, e.g., it directs research to highly…

  3. The households of Serbia at the dawn of third millennium: Socio-demographical analysis

    Directory of Open Access Journals (Sweden)

    Bobić Mirjana

    2004-01-01

    Full Text Available Side by side with tumultuous social processes in the end of XXth century great demographical changes have been taking place in Serbia, such as: the decline of nuptiality and fertility, postponement of family formation into older ages of life course of individuals, the rise of: extramarital births as well as adolescent pregnancies and live births, the spread of one-parent households, particularly of lone mothers, and divorces. Besides that, the main feature of the demographic development of Serbia has been increased mobility of population, namely migrations of highly educated professionals to the West ("brain drain" and forced migration of refugees and internally displaced persons to Serbia, as a consequence of armed conflicts in its surroundings and at Kosovo and Metohija. All the above-mentioned demographical changes caused the precomposition of households, as profound associations of population, where its biological and socio-economical reproductions take place. The information of last census of population of Serbia in 2002 indicate that according to the features of family and households, Serbia has approached the countries of Central and Eastern Europe, that are forerunning in the process of post-socialistic transformation and European integrations. Common characteristics of all those countries are: decrease of universality and popularity of marriage delay of childbearing, continuation of earlier demographic tendencies: of low natality, depopulation and aging of population. All those processes have contributed to the transformation of prevailing forms of households, i.e. decline of nuclear family units and the rise of single person households households of aged persons, as well as single-parent ones. As to the Serbia the demographic differences between its separate parts: Vojvodina and central Serbia, have been fading for the first time in its history, owing to previous socio-demographic developments starting from the beginning of XXth

  4. Chiropractors in Finland – a demographic survey

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    Malmqvist Stefan

    2008-08-01

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

  5. Demographic shifts in the Czech Republic after 1989 : A second demographic transition view

    NARCIS (Netherlands)

    Sobotka, T.; Zeman, K.; Kantorova, V.

    2003-01-01

    A dramatic change in fertility, family formation and living arrangements took place in the Czech Republic over the 1990s. The establishment of democracy, profound social transformation and transition to the market economy affected the values and demographic behaviour of the young Czech generation.

  6. Demographic and Citation Trends in Astrophysical Journal papers and Reports

    CERN Document Server

    Schwarz, G J

    2004-01-01

    We have used data from ADS, AAS, and astro-ph, to study the publishing, preprint posting, and citation patterns for papers published in the ApJ in 1999 and 2002. This allowed us to track statistical trends in author demographics, preprint posting habits, and citation rates for ApJ papers as a whole and across various subgroups and types of ApJ papers. The most interesting results are the frequencies of use of the astro-ph server across various subdisciplines of astronomy, and the impact that such posting has on the citation history of the subsequent ApJ papers. By 2002 72% of ApJ papers were posted as astro-ph preprints, but this fraction varies from 22-95% among the subfields studied. A majority of these preprints (61%) were posted after the papers were accepted at ApJ, and 88% were posted or updated after acceptance. On average, ApJ papers posted on astro-ph are cited more than twice as often as those that are not posted on astro-ph. This difference can account for a number of other, secondary citation tren...

  7. Postpartum depression and psycho-socio-demographic predictors.

    Science.gov (United States)

    Abdollahi, Fatemeh; Sazlina, Shariff-Ghazali; Zain, Azhar Md; Zarghami, Mehran; Asghari Jafarabadi, Mohammad; Lye, Munn-Sann

    2014-12-01

    There appears to be a growing international recognition of postpartum depression as a significant public health concern. This paper determined the prevalence and psycho-socio-demographic predictors of postpartum depression symptomatology and its constancy over 12-week postpartum in Mazandaran province Iranian women. Edinburgh Postnatal Depression Scale and General Health Questionnaire were used to identify possible health and depression status in a cohort of 1,950 eligible pregnant women who attended primary health centers from January to June 2010, at 2 and 12 weeks postpartum. Logistic regression analysis was used to determine the predictors of postpartum depression among women. Prevalence of continued depression was found to be 9.9% on all three assessments. A mother's psychological distress, experience of depression, and anxiety in the first and second trimester of pregnancy and a family history of depression were the characteristics that had the strongest significant association with the development of postpartum depression. Women who married at a younger age also were more prone to postpartum depression development. One in ten depressed women in this study continued to be depressed over the 12-week postpartum period. Interventions should target women with the greatest risk, especially those with psychological distress during pregnancy. © 2014 Wiley Publishing Asia Pty Ltd.

  8. 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...

  9. Virtual water controlled demographic growth of nations

    CERN Document Server

    Suweis, Samir; Maritan, Amos; D'Odorico, Paolo

    2013-01-01

    Population growth is in general constrained by food production, which in turn depends on the access to water resources. At a country level, some populations use more water than they control because of their ability to import food and the virtual water required for its production. Here, we investigate the dependence of demographic growth on available water resources for exporting and importing nations. By quantifying the carrying capacity of nations based on calculations of the virtual water available through the food trade network, we point to the existence of a global water unbalance. We suggest that current export rates will not be maintained and consequently we question the long-run sustainability of the food trade system as a whole. Water rich regions are likely to soon reduce the amount of virtual water they export, thus leaving import-dependent regions without enough water to sustain their populations. We also investigate the potential impact of possible scenarios that might mitigate these effects throu...

  10. 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.

  11. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

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

    2011-01-01

    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...... sonography to depict tumor neovascularization can be increased by contrast agents. Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion. In the future, these techniques could potentially be used to quantify tumor perfusion, to assess...

  12. Trust and its Relationship to Demographic Factors

    Directory of Open Access Journals (Sweden)

    Asghar Mirfardi

    2011-01-01

    Full Text Available Problem statement: Social trust is the main theme in the social life. Trust is “the expectation that arises within a community of regular, honest and cooperative behavior, based on commonly shared norms”. Development, social trust and security are intertwined categories and have interaction to each other. Social trust, as a main factor in social capital, provide social context for developmental programs. This study, examine the affect of Demographic factors on the social trust to others. As social trust is a key factor in social relationship, this study is needed to evaluate such factor according to demographic factors. Approach: This study has been done on existing data about Iranian values and attitudes. Some factors such as gender, age, education level, job situation, marital situation have been studied in this study. Some of these variables such as education, correspondence to development level, especially in social development. This study is done via documental method (archive and Documental data about mentioned themes and second analysis of The Iranian National Values and attitudes Survey (2000. Results: Findings of this study indicated that there is significant relationship between all of independent variables (Gender, age, education level, job situation, marital situation and social trust to families and relatives, there is significant relationship between variables such as gender, education level, job situation, marital situation (independent variables and social trust to friends. Analyzing the data showed that, the residents of less and more developed cities have different situation in trust. Conclusion/Recommendations: This study introduces three types of trust upon the development level of societies. Trust in Iran is an example of trust structure in developing societies.

  13. Geriatric trauma: demographics, injuries, and mortality.

    Science.gov (United States)

    Keller, Julie M; Sciadini, Marcus F; Sinclair, Elizabeth; O'Toole, Robert V

    2012-09-01

    To identify injuries that elderly sustain during high-energy trauma and determine which are associated with mortality. Retrospective review of prospectively collected database. Academic trauma center. Patients selected from database of all trauma admissions from January 2004 through June 2009. Study population consisted of patients directly admitted from scene of injury who sustained high-energy trauma with at least one orthopaedic injury and were 65 years or older (n = 597). Review of demographics, trauma markers, injuries, and disposition statuses. Statistical analysis using χ test, Student t test, and logistic regression analysis. The most common fractures were of the rib, distal radius, pelvic ring, facial bones, proximal humerus, clavicle, ankle, and sacrum. The injuries associated with the highest mortality rates were fractures of the cervical spine with neurological deficit (47%), at the C2 level (44%), and of the proximal femur (25%), pelvic ring (25%), clavicle (24%), and distal humerus (24%). The fractures significantly associated with mortality were fractures of the clavicle (P = 0.001), foot joints (P = 0.001), proximal humerus or shaft and head of the humerus (P = 0.002), sacroiliac joint (P = 0.004), and distal ulna (P = 0.002). Elderly patients present with significantly worse injuries, remain in the hospital longer, require greater use of resources after discharge, and die at 3 times the rate of the younger population. Although the high mortality rates associated with cervical spine, hip, and pelvic ring fractures were not unexpected, the injuries that were statistically associated with mortality were unexpected. Injuries such as clavicle fracture were statistically associated with mortality. As our population ages and becomes more active, the demographic may gain in clinical importance. Prognostic Level II. See Instructions for Authors for a complete description of levels of evidence.

  14. Discourse Theory and "Contrastive Rhetoric."

    Science.gov (United States)

    Bar-Lev, Zev

    1986-01-01

    Appraises R. Kaplan's "contrastic rhetoric" in the light of a multilanguage research project on discourse structure. Concludes that Kaplan's specific analyses are in need of substantive revision. (FL)

  15. Fuzzy-Contextual Contrast Enhancement.

    Science.gov (United States)

    Parihar, Anil; Verma, Om; Khanna, Chintan

    2017-02-08

    This paper presents contrast enhancement algorithms based on fuzzy contextual information of the images. We introduce fuzzy similarity index and fuzzy contrast factor to capture the neighborhood characteristics of a pixel. A new histogram, using fuzzy contrast factor of each pixel is developed, and termed as the fuzzy dissimilarity histogram (FDH). A cumulative distribution function (CDF) is formed with normalized values of FDH and used as a transfer function to obtain the contrast enhanced image. The algorithm gives good contrast enhancement and preserves the natural characteristic of the image. In order to develop a contextual intensity transfer function, we introduce a fuzzy membership function based on fuzzy similarity index and coefficient of variation of the image. The contextual intensity transfer function is designed using the fuzzy membership function to achieve final contrast enhanced image. The overall algorithm is referred as the fuzzy contextual contrast-enhancement (FCCE) algorithm. The proposed algorithms are compared with conventional and state-of-art contrast enhancement algorithms. The quantitative and visual assessment of the results is performed. The results of quantitative measures are statistically analyzed using t-test. The exhaustive experimentation and analysis show the proposed algorithm efficiently enhances contrast and yields in natural visual quality images.

  16. Dynamic heterogeneity in life histories

    DEFF Research Database (Denmark)

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

    2009-01-01

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

  17. [Demographic analysis of the blue shark, Prionace glauca, in the North Atlantic Ocean].

    Science.gov (United States)

    Gao, Chun-xia; Dai, Xiao-jie; Tian, Si-quan; Wu, Feng; Zhu, Jiang-feng

    2016-02-01

    The blue shark, Prionace glauca, is the main by-catch species in tuna longline fishery. As one of top species in the oceanic food webs, the blue shark plays an important role in the marine ecosystem. Traditional stock assessment methods are difficult to accurately evaluate the population dynamic for this shark because of limited data. Based on life-history parameters of the blue shark in the North Atlantic, demographic analysis was employed to estimate the demographic parameters and evaluate the potential exploitation for the blue shark. Moreover, we discussed the relationship between age at first capture and critical value of fishing mortality corresponding to the value of intrinsic rate of natural increase 0. The results showed that the survival rate (S) of blue shark from 0.719 to 0.820, intrinsic rate of natural increase (r0) from 0.250 to 0.381, time of population doubling (tx2) from 1.819 to 2.773 years, reproduction rate per generation (R0) from 6.600 to 22.255, and generation time (G) from 8.498 to 10.162 years. The sensitivity analysis for the life history parameters revealed that the uncertainties of natural mortality existed in the first age class, age at maturity and maximum age had slight influence on the demographic parameters. Fishing mortality (Fc) increased with the age at first capture. When the age at first capture (tc) was more than five, there was no obvious relationship between Fc and tc.

  18. Climatic influence on demographic parameters of a tropical seabird varies with age and sex.

    Science.gov (United States)

    Oro, Daniel; Torres, Roxana; Rodríguez, Cristina; Drummond, Hugh

    2010-04-01

    In marine ecosystems climatic fluctuation and other physical variables greatly influence population dynamics, but differential effects of physical variables on the demographic parameters of the two sexes and different age classes are largely unexplored. We analyzed the effects of climate on the survival and recruitment of both sexes and several age classes of a long-lived tropical seabird, the Blue-footed Booby (Sula nebouxii), using long-term observations on marked individuals. Results demonstrated a complex interaction between yearly fluctuations in climate (both local and global indexes, during both winter and breeding season) and the sex and age of individuals. Youngest birds' survival and recruitment were commonly affected by local climate, whereas oldest birds' parameters tended to be constant and less influenced by environmental variables. These results confirm the theoretical prediction that sex- and age-related variation in life-history demographic traits is greater under poor environmental conditions, and they highlight the importance of including variability in fitness components in demographic and evolutionary models. Males and females showed similar variation in survival but different recruitment patterns, in relation to both age and the spatial scale of climatic influence (local or global). Results indicate different life-history tactics for each sex and different ages, with birds likely trying to maximize their fitness by responding to the environmental contingencies of each year.

  19. Demographische Diskurse und Politiken aus Geschlechterperspektive Demographic Discourse and Politics from the Perspective of Gender

    Directory of Open Access Journals (Sweden)

    Diana Auth

    2007-07-01

    Full Text Available Der von Peter A. Berger und Heike Kahlert herausgegebene Sammelband umfasst Analysen, die sich aus Geschlechterperspektive mit dem demographischen Wandel im nationalen und internationalen Kontext beschäftigen. Durch seine ideologie- und herrschaftskritischen sowie empirisch fundierten Beiträge zum demographischen Wandel trägt das Buch zur Versachlichung der medial wie wissenschaftlich aufgeheizten Debatte bei. Die Autor/-innen widersprechen allesamt der Tendenz, soziale Probleme zu demographisieren, und fordern stattdessen eine stärkere Historisierung, Kontextualisierung und eine geschlechtssensible Analyse und Interpretation demographischer Entwicklungen.The collected volume, edited by Peter A. Berger and Heike Kahlert, contains analyses that concern themselves with demographic change in the national and international context. The book contains empirically based articles on demographic change that are critical of ideology and dominance, thus contributing to the objectification of the heated debate in the media and science. The authors all contradict the tendency to demographically position social problems and demand instead a stronger focus on history, contextualization, and a gender-sensitive analysis and interpretation of demographic developments.

  20. Spatial continuities and discontinuities in two successive demographic transitions: Spain and Belgium, 1880-2010

    Directory of Open Access Journals (Sweden)

    Ron Lesthaeghe

    2013-01-01

    Full Text Available This is a study of how the synergisms between cultural and structural factors, which played a major role during the historical fertility and nuptiality transition (first demographic transition or FDT, have continued to condition demographic innovations connected to the "second demographic transition" (SDT. The continuity or discontinuity from the "first" to the "second" demographic transition is studied for spatial aggregates over more than a century in two national contexts, i.e., Belgium and Spain. Special attention is paid to the role of successive secularization waves in shaping the geographical patterns of both transitions. The study also shows that the maps of the two aspects of the SDT, i.e., the "postponement" and the "non-conformism" transitions respectively, are shaped by different determinants. Explanations are offered using the "Ready, Willing, and Able" paradigm, which allows us to uncover the different conditioning and limiting factors involved. The "non-conformist" transitions (control of marital fertility during the FDT and rise of cohabitation and non-conventional family formation during the SDT more closely mirror the history of secularization and the "Willingness" condition, whereas the fertility postponement aspect of the SDT mainly reflects female education and employment, or the "Readiness" condition. This generalization holds in both countries. However, in Belgium spatial continuity from FDT to SDT is connected to stable patterns of secularization, whereas in Spain it is linked to long standing differences with respect to female literacy and education.

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

    NARCIS (Netherlands)

    Tieleman, BI; Williams, JB; Visser, GH

    2004-01-01

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

  2. 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.

  3. Contrast discrimination at high contrasts reveals the influence of local light adaptation on contrast processing.

    Science.gov (United States)

    Kingdom, F A; Whittle, P

    1996-03-01

    Previous measurements of contrast discrimination threshold, delta C, as a function of pedestal contrast, C, for sine-wave gratings have shown a power law relationship between delta C and C at suprathreshold levels of C. However, these studies have rarely used contrasts greater than 50%. Whittle (1986), using incremental and decremental patches, found that delta C increased with C only up to about 50%. At higher contrasts it decreased. Since a periodic stimulus can be considered to be composed of increments and decrements, we thought we might find such an inverse U-shaped function for gratings if we used contrasts up to 100%. We tested this for both sine-wave and square-wave stimuli at spatial frequencies from 0.0625 to 8.0 c/deg. We found that for frequencies up to 0.5 c/deg, delta C in nearly all cases 'dipped down' after about C = 50% contrast. At 4.0 and 8.0 c/deg, however, no dip-down occurred. Additional experiments showed that the dip-down was unlikely to be due to cortical long-term adaptation and most likely an effect of localized light adaptation to the dark bars. We argue that the absence of dip-down at high spatial frequencies was mainly due to the attenuation of contrast by the optics of the eye. As for the results of Whittle (1986), a Weber's Law in W = (Lmax-Lmin)/Lmin describes the inverse U-shaped contrast discrimination function well. Two other contrast expressions also linearize the data on log-log plots. We show how some familiar notions about the physiological operation of localized light adaptation can easily account for the form of the contrast discrimination function. Finally we estimate the number of discriminable steps in contrast from detection threshold to maximum contrast for the various spatial frequencies tested.

  4. Future forest aboveground carbon dynamics in the central United States: the importance of forest demographic processes

    Science.gov (United States)

    Jin, Wenchi; He, Hong S.; Thompson, Frank R.; Wang, Wen J.; Fraser, Jacob S.; Shifley, Stephen R.; Hanberry, Brice B.; Dijak, William D.

    2017-01-01

    The Central Hardwood Forest (CHF) in the United States is currently a major carbon sink, there are uncertainties in how long the current carbon sink will persist and if the CHF will eventually become a carbon source. We used a multi-model ensemble to investigate aboveground carbon density of the CHF from 2010 to 2300 under current climate. Simulations were done using one representative model for each of the simple, intermediate, and complex demographic approaches (ED2, LANDIS PRO, and LINKAGES, respectively). All approaches agreed that the current carbon sink would persist at least to 2100. However, carbon dynamics after current carbon sink diminishes to zero differ for different demographic modelling approaches. Both the simple and the complex demographic approaches predicted prolonged periods of relatively stable carbon densities after 2100, with minor declines, until the end of simulations in 2300. In contrast, the intermediate demographic approach predicted the CHF would become a carbon source between 2110 and 2260, followed by another carbon sink period. The disagreement between these patterns can be partly explained by differences in the capacity of models to simulate gross growth (both birth and subsequent growth) and mortality of short-lived, relatively shade-intolerant tree species. PMID:28165483

  5. Nonlinear intravascular ultrasound contrast imaging

    NARCIS (Netherlands)

    Goertz, David E.; Frijlink, Martijn E.; de Jong, N.; van der Steen, Antonius F.W.

    2006-01-01

    Nonlinear contrast agent imaging with intravascular ultrasound (IVUS) is investigated using a prototype IVUS system and an experimental small bubble contrast agent. The IVUS system employed a mechanically scanned single element transducer and was operated at a 20 MHz transmit frequency (F20) for

  6. Contrast enhancement in light microscopy.

    Science.gov (United States)

    Ernst Keller, H; Watkins, Simon

    2013-01-01

    The optical microscope is a fundamental component of an image cytometry system. This unit covers the basic concepts of light microscopy, including Köhler illumination, resolution, contrast, and numerical aperture, and reviews the many types of instruments and techniques for contrast enhancement.

  7. Contrast-enhanced peripheral MRA

    DEFF Research Database (Denmark)

    Nielsen, Yousef W; Thomsen, Henrik S

    2012-01-01

    In the last decade contrast-enhanced magnetic resonance angiography (CE-MRA) has gained wide acceptance as a valuable tool in the diagnostic work-up of patients with peripheral arterial disease. This review presents current concepts in peripheral CE-MRA with emphasis on MRI technique and contrast...

  8. Genetic diversity and demographic history of the dromedary camel (Camelus dromedarius)

    OpenAIRE

    Almathen, Faisal

    2014-01-01

    The dromedary camel (Camelus dromedarius) commonly referred to as ‘ship of the desert’ has played an important part in the development and expansion of trading networks across inhospitable habitats over 3000 years, linking Arabian, Asian, African and European civilisations. Caravan roads, which are part of the major trading networks, have facilitated livestock exchange across large geographic distances. Dromedary camels are known to have been extensively used as pack animals along these carav...

  9. 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 ...

  10. Conservation genetics of local and wild pig populations : insight in genetic diversity and demographic history

    NARCIS (Netherlands)

    Herrero Medrano, J.

    2013-01-01

    Het doel van het onderzoek zoals beschreven in dit proefschrift was om de genetische diversiteit en demografische geschiedenis van lokale varkenspopulaties te verkennen middels het integreren van verschillende genetische merker systemen.

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

    NARCIS (Netherlands)

    Francioli, Laurent C.; Menelaou, Andronild; Pulit, Sara L.; Van Dijk, Freerk; Palamara, Pier Francesco; Elbers, Clara C.; Neerincx, Pieter B. T.; Ye, Kai; Guryev, Victor; Kloosterman, Wigard P.; Deelen, Patrick; Abdellaoui, Abdel; Van Leeuwen, Elisabeth M.; Van Oven, Mannis; Vermaat, Martijn; Li, Mingkun; Laros, Jeroen F. J.; Karssen, Lennart C.; Kanterakis, Alexandros; Amin, Najaf; Hottenga, Jouke Jan; Lameijer, Eric-Wubbo; Kattenberg, Mathijs; Dijkstra, Martijn; Byelas, Heorhiy; Van Settenl, Jessica; Van Schaik, Barbera D. C.; Bot, Jan; Nijman, Isaac J.; Renkens, Ivo; Marscha, Tobias; Schonhuth, Alexander; Hehir-Kwa, Jayne Y.; Handsaker, Robert E.; Polak, Paz; Sohail, Mashaal; Vuzman, Dana; Hormozdiari, Fereydoun; Van Enckevort, David; Mei, Hailiang; Koval, Vyacheslav; Moed, Ma-Tthijs H.; Van der Velde, K. Joeri; Rivadeneira, Fernando; Estrada, Karol; Medina-Gomez, Carolina; Isaacs, Aaron; McCarroll, Steven A.; Beekrnan, Marian; De Craen, Anton J. M.; Suchiman, H. Eka D.; Hofman, Albert; Oostra, Ben; Uitterlinden, Andre G.; Willemsen, Gonneke; Platteel, Mathieu; Veldink, Jan H.; Van den Berg, Leonard H.; Pitts, Steven J.; Potluri, Shobha; Sundar, Purnima; Cox, David R.; Sunyaev, Shamil R.; Den Dunnen, Johan T.; Stoneking, Mark; De Knijff, Peter; Kayser, Manfred; Li, Qibin; Li, Yingrui; Du, Yuanping; Chen, Ruoyan; Cao, Hongzhi; Li, Ning; Cao, Sujie; Wang, Jun; Bovenberg, Jasper A.; Peer, Itsik; Slagboom, P. Eline; Van Duijn, Cornelia M.; Boomsma, Dorret I.; Van Ommen, Gert-Jan B.; De Bakker, Paul I. W.; Swertz, Morris A.; Wijmenga, Cisca

    2014-01-01

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

  12. Phylogeography and demographic history of Amblyomma variegatum (Fabricius) (Acari: Ixodidae), the tropical bont tick.

    Science.gov (United States)

    Beati, Lorenza; Patel, Jaymin; Lucas-Williams, Helene; Adakal, Hassane; Kanduma, Esther G; Tembo-Mwase, Enala; Krecek, Rosina; Mertins, James W; Alfred, Jeffery T; Kelly, Susyn; Kelly, Patrick

    2012-06-01

    The genetic diversity of Amblyomma variegatum (Fabricius) from four Caribbean islands and five African countries was compared by analyzing the sequences of three gene fragments, two mitochondrial (12SrDNA and D-Loop-DL), and one nuclear (intergenic transcribed spacer 2 [ITS2]). Genetic variability of the ITS2 DNA fragment consisted of only uninformative single nucleotide mutations, and therefore this gene was excluded from further analyses. Mitochondrial gene divergences among African populations and between Caribbean and African populations were very low. Nevertheless, the data suggest that A. variegatum is divided into distinct East and West African groups, the western group including all Caribbean samples. Phylogenetic analyses of the 12SrDNA and DL gene sequences showed that the West African A. variegatum clustered in a well-supported monophyletic clade, distinct from eastern paraphyletic lineages. Sequences of A. variegatum from the Caribbean were embedded in the West African clade, which supports the known West African historical origin for these ticks.

  13. Inferring the population structure and demographic history of the tick, Amblyomma americanum Linnaeus.

    Science.gov (United States)

    Mixson, Tonya R; Lydy, Shari L; Dasch, Gregory A; Real, Leslie A

    2006-06-01

    A hierarchial population genetic study was conducted on 703 individual Amblyomma americanum from nine populations in Georgia, U.S.A. Populations were sampled from the Coastal Plain, midland Piedmont region, and the upper Piedmont region. Twenty-nine distinct haplotypes were found. A minimum spanning tree was constructed that indicated these haplotypes comprised two lineages, the root of which was distinctly star-like. The majority of the variation found was among ticks within each population, indicating high amounts of gene flow and little genetic differentiation between the three regions. An overall F(ST) value of 0.006 supported the lack of genetic structuring between collection sites in Georgia. Mantel regression analysis revealed no isolation by distance. Signatures of population expansion were detected in the shapes of the mismatch distribution and tests of neutrality. The absence of genetic differentiation combined with the rejection of the null model of isolation by distance may indicate recent range expansion in Georgia or insufficient time to reach an equilibrium where genetic drift may have affected allele frequencies. Alternatively, the high degree of panmixia found within A. americanum in Georgia may be due to bird-mediated dispersal of ticks increasing the genetic similarity between geographically separated populations.

  14. Phylogeography and Demographic History of Amblyomma variegatum (Fabricius) (Acari: Ixodidae), the Tropical Bont Tick

    OpenAIRE

    Beati, Lorenza; Patel, Jaymin; Lucas-Williams, Helene; Adakal, Hassane; Kanduma, Esther G.; Tembo-Mwase, Enala; Krecek, Rosina; Mertins, James W.; Alfred, Jeffery T.; Kelly, Susyn; Kelly, Patrick

    2012-01-01

    The genetic diversity of Amblyomma variegatum (Fabricius) from four Caribbean islands and five African countries was compared by analyzing the sequences of three gene fragments, two mitochondrial (12SrDNA and D-Loop-DL), and one nuclear (intergenic transcribed spacer 2 [ITS2]). Genetic variability of the ITS2 DNA fragment consisted of only uninformative single nucleotide mutations, and therefore this gene was excluded from further analyses. Mitochondrial gene divergences among African populat...

  15. 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

    , coinciding with the closure of the Panama Gateway that led to reinforcement of the Gulf Stream. This could have advected larvae towards European/North African coasts, in which case American eel would be expected to be the ancestral species. This scenario could, however, not be unequivocally confirmed...... for positive selection at the ATP6 and possibly ND5 genes, indicating a role in speciation. The findings suggest an important role of ocean current changes in speciation of marine organisms...

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

    Science.gov (United States)

    Jacobsen, M W; Pujolar, J M; Gilbert, M T P; Moreno-Mayar, J V; Bernatchez, L; Als, T D; Lobon-Cervia, J; Hansen, M M

    2014-11-01

    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 European/North African and North American coasts, respectively. We analyzed 104 mitogenomes from the two species along with mitogenomes of other Anguilla and outgroup species. We estimated divergence time between the two species to identify major events involved in speciation. We also considered two previously stated hypotheses: one where the ancestral species was present in only one continent but was advected across the Atlantic by ocean current changes and another where population declines during Pleistocene glaciations led to increasing vicariance, facilitating speciation. Divergence time was estimated to ∼3.38 Mya, coinciding with the closure of the Panama Gateway that led to reinforcement of the Gulf Stream. This could have advected larvae towards European/North African coasts, in which case American eel would be expected to be the ancestral species. This scenario could, however, not be unequivocally confirmed by analyses of dN/dS, nucleotide diversity and effective population size estimates. Extended bayesian skyline plots showed fluctuations of effective population sizes and declines during glaciations, and thus also lending support to the importance of vicariance during speciation. There was evidence for positive selection at the ATP6 and possibly ND5 genes, indicating a role in speciation. The findings suggest an important role of ocean current changes in speciation of marine organisms.

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

    Science.gov (United States)

    Fratini, Sara; Ragionieri, Lapo; Cannicci, Stefano

    2010-01-01

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

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

    DEFF Research Database (Denmark)

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

    2008-01-01

    The field of ancient DNA (aDNA) is casting new light on many evolutionary questions. However, problems associated with the postmortem instability of DNA may complicate the interpretation of aDNA data. For example, in population genetic studies, the inclusion of damaged DNA may inflate estimates...... 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...

  19. 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...... 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...

  20. Phylogeography and demographic history of Lacerta lepida in the Iberian Peninsula

    DEFF Research Database (Denmark)

    Miraldo, Andreia; Hewitt, Godfrey M; Paulo, Octavio S;

    2011-01-01

    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...

  1. 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

    genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Results: Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence...

  2. 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...

  3. A demographic-economic explanation of political stability: Mauritius as a microcosm.

    Science.gov (United States)

    Lempert, D

    1987-06-01

    "This paper examines current models of economic and political development--social modernization theory, political and economic characteristics of stable regimes, and cross country analysis of political stability--and tests them on the Indian Ocean Island of Mauritius. The analysis continues with a causal explanation for political stability in Mauritius' recent history, derived from an examination of economic policies and demographic patterns. Political change in Mauritius over the past sixty years seems to be explained best by a model for political stability which integrates specific economic and demographic factors. The model, applicable to development in other third world nations, revises Malthus' conclusion that population and economic conditions move in an oscillatory relationship and replaces it with a more comprehensive theory, suggesting that political stability is a function of both economic development and a repeating cyclical relationship between economics and population."

  4. Demographic estimates from Y chromosome microsatellite polymorphisms: Analysis of a worldwide sample

    Directory of Open Access Journals (Sweden)

    Macpherson J

    2004-08-01

    Full Text Available Abstract Polymorphisms in microsatellites on the human Y chromosome have been used to estimate important demographic parameters of human history. We compare two coalescent-based statistical methods that give estimates for a number of demographic parameters using the seven Y chromosome polymorphisms in the HGDP-CEPH Cell Line Panel, a collection of samples from 52 worldwide populations. The estimates for the time to the most recent common ancestor vary according to the method used and the assumptions about the prior distributions of model parameters, but are generally consistent with other global Y chromosome studies. We explore the sensitivity of these results to assumptions about the prior distributions and the evolutionary models themselves.

  5. 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

  6. 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.

  7. Socio-demographic factors and cervical length in pregnancy.

    Science.gov (United States)

    Petrović, Dorde; Novakov-Mikić, Aleksandra; Mandić, Vesna

    2008-01-01

    The cervical length is an important factor in the risk evaluation of preterm delivery. The aim of this work was to determine the correlation between the cervical length and the demographic characteristics. A transversal type prospective study was done on a sample of 579 pregnant women at various gestational age of low risk mono-fetal pregnancy. The cervical length was measured by trans-vaginal ultrasound procedure within the regular pregnancy monitoring process. The following data were taken into consideration: the woman's age, her body mass at the beginning of the pregnancy and her height in order to calculate the body mass index as well as her smoking habit at the moment of conception. The mean cervical length was 34.3 mm and 35 mm in the group of women aged 30 and less and 31 and over, respectively. The cervix was insignificantly shorter in younger women (being 34.9 mm/35.9 mm in the 1st trimester, 34.5 mm/35.1 mm in the 2nd one and 33.9 mm/34.7 mm in the 3rd trimester). The sample of 579 pregnant women consisted of 448 non-smokers and 131 smokers. The difference in the length of the cervix in smokers and nonsmokers was not significant (being 32.2 mm/35.9 mm; 35 mm/34 mm and 34.4 mm/33.5 mm in the 1st, 2nd and 3rd trimester, respectively). The correlation between the body mass index and the cervical length was analyzed by trimesters. In the first trimester the increase in the body mass index was followed by the shortening of the cervix; the cervical length was not affected by the BAI in the second trimester, whereas the higher the body mass index the longer the cervix in the third trimester. Our study has shown that the cervical length is affected neither by the age of the woman nor her smoking habit but it is affected by the body mass index at the moment of conception, that linear trend being negative in the 1st trimester but positive in the 3rd one. Since the cervical length may be affected not only by the socio-demographic characteristics but the gynecologic

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

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Yousef W. [Dept. of Radiology, Copenhagen Univ. Hospital Bispebjerg, Bispebjerg (Denmark)], e-mail: ywnielsen@gmail.com; Thomsen, Henrik S. [Dept. of Diagnostic Radiology, Copenhagen Univ. Hospital Herlev, Herlev (Denmark)

    2012-09-15

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

  9. Demographic impact of vaccination: a review.

    Science.gov (United States)

    Bonanni, P

    1999-10-29

    Vaccination is one of the most powerful means to save lives and to increase the level of health of mankind. However, the impact of immunization against the most threatening infectious agents on life expectancy has been the object of a still open debate. The main issues are: the relative influence of nutrition and infectious diseases on demographic patterns of populations; the possibility that lives saved thanks to vaccination are subsequently lost due to other competing causes of death; the positive indirect effect of immunization on other causes of death. With regard to past evidence, several data from the United Kingdom and Scandinavian countries show that the widespread use of smallpox vaccination starting at the beginning of the nineteenth century resulted in a marked and sustained decline not only of smallpox-related deaths, but also of the overall crude death rate, and contributed greatly to an unprecedented growth of European population. As to the present, it is estimated that 3 million children are saved annually by vaccination, but 2 million still die because they are not immunized. Tetanus, measles and pertussis are the main vaccine-preventable killers in the first years of life. Data from Bangladesh show that full implementation of EPI vaccines has the potential of reducing mortality by almost one half in children aged 1-4 years. Recent progress in the development of vaccines against agents responsible for much mortality in the developing countries make it possible to forecast a further substantial reduction of deaths for infectious diseases in the next century.

  10. The shifting demographic landscape of pandemic influenza.

    Directory of Open Access Journals (Sweden)

    Shweta Bansal

    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.

  11. Coping behaviour of female teachers: Demographic determinants

    Directory of Open Access Journals (Sweden)

    M Chaturvedi

    2009-01-01

    Full Text Available Background: The study investigates the role of certain demographic variables in determining stress-coping behavior of female teachers. Materials and Methods: The sample consists of 150 female teachers selected by stratified sampling method from various schools of Bhopal. Stress-coping behavior was measured with the help of a subscale of ′The Occupational Stress Indicator′ (Wendy Lord, 1993 consisting of 28 items encompassing six dimensions of coping strategies i.e. Logics, Involvement, Social Support, Task Strategies, Time Management and Home and Work Relations. The scores of the subjects were compared in terms of marital status, age, and level of teaching with the help of ′t′ test and ′F′ test was used for comparing experience. Results: Marital status, age, and experience were found to be significant determinants of stress-coping, whereas the sores did not differ significantly on the basis of level of teaching. Conclusion: Married teachers in the age range of 40-60 years, with higher experience can cope better with the job stress than their counterparts.

  12. Demographics of Resonances in Exoplanetary Systems

    Science.gov (United States)

    Ragozzine, Darin; Conaway, James L.; MacDonald, Mariah G.; Sallee, Victor

    2016-10-01

    NASA's Kepler Space Telescope has identified ~700 systems of multiple transiting exoplanets containing ~1700 planets. Most of these multi-transiting systems have 3-5 planets small planets with periods of roughly 5-50 days and are known as Systems with Tightly-spaced Inner Planets (STIPs). These information-rich exoplanetary systems have precisely measured period ratios which allows for the identification and characterization of orbital mean motion resonances. Improved understanding of the resonant populations will reveal much about the formation and evolution of planetary systems. Lissauer, Ragozzine, et al. 2011 found that most Kepler systems were not in resonance, but that there was a small excess of planets wide of resonance. We present new analyses that rigorously identify the frequency of planets in multiple resonances (including three-body resonances) and thus identify many specific new results on the demographics of resonances. We also show that the apparent over-abundance of resonances can be attributed to a difference in inclinations (potentially from dissipation) with implications for the true underlying frequency of resonant systems. We compare the period ratio distribution of Kepler (corrected for inclination biases) to Radial Velocity (RV) surveys and conclude that RV systems are often missing small intermediate planets. This has serious implications for the completeness of RV identification of planets in STIPs.

  13. 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.

  14. Multimodal nanoparticulate bioimaging contrast agents.

    Science.gov (United States)

    Sharma, Parvesh; Singh, Amit; Brown, Scott C; Bengtsson, Niclas; Walter, Glenn A; Grobmyer, Stephen R; Iwakuma, Nobutaka; Santra, Swadeshmukul; Scott, Edward W; Moudgil, Brij M

    2010-01-01

    A wide variety of bioimaging techniques (e.g., ultrasound, computed X-ray tomography, magnetic resonance imaging (MRI), and positron emission tomography) are commonly employed for clinical diagnostics and scientific research. While all of these methods use a characteristic "energy-matter" interaction to provide specific details about biological processes, each modality differs from another in terms of spatial and temporal resolution, anatomical and molecular details, imaging depth, as well as the desirable material properties of contrast agents needed for augmented imaging. On many occasions, it is advantageous to apply multiple complimentary imaging modalities for faster and more accurate prognosis. Since most imaging modalities employ exogenous contrast agents to improve the signal-to-noise ratio, the development and use of multimodal contrast agents is considered to be highly advantageous for obtaining improved imagery from sought-after imaging modalities. Multimodal contrast agents offer improvements in patient care, and at the same time can reduce costs and enhance safety by limiting the number of contrast agent administrations required for imaging purposes. Herein, we describe the synthesis and characterization of nanoparticulate-based multimodal contrast agent for noninvasive bioimaging using MRI, optical, and photoacoustic tomography (PAT)-imaging modalities. The synthesis of these agents is described using microemulsions, which enable facile integration of the desired diversity of contrast agents and material components into a single entity.

  15. [The colonial state and demographic knowledge in French West Africa, 1904-1960].

    Science.gov (United States)

    Gervais, R R

    1996-01-01

    "Our lack of knowledge on the production of population estimates in France's colonial empire is in sharp contrast to the efforts of British authorities after 1940. To understand this ¿omission', we have to assess the numerous oppositions existing within the French colonial state.... After the first memoranda of 1904 and 1909, colonial census-taking activities were inexorably merged with everyday administrative tasks: taxation, justice, policing, etc. This shift clearly influenced the form and function of demographic knowledge in French West Africa (AOF).... We conclude with a mixed assessment of attempts to amass demographic knowledge and especially of the influence such knowledge actually had on decision-making." (SUMMARY IN ENG AND SPA)

  16. Epistemological Distinctions Between Science and History

    CERN Document Server

    Courtney, Michael

    2008-01-01

    This article describes epistemological distinctions between science and history. Science investigates models of natural law using repeatable experiments as the ultimate arbiter. In contrast, history investigates past events by considering physical evidence, documentary evidence, and eyewitness testimony. Because questions of natural law are repeatably testable by any audience that exercises due experimental care, models of natural law are inherently more objective and testable with greater certainty than theories of past events.

  17. 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

  18. Popular history magazines and history education

    Directory of Open Access Journals (Sweden)

    Robert Thorp

    2016-05-01

    Full Text Available This paper argues that popular history magazines may be a welcome complement to other forms of historical media in history teaching. By outlining a theoretical framework that captures uses of history, the paper analyses popular history magazine articles from five European countries all dealing with the outbreak of World War I. The study finds that while the studied articles provide a rather heterogeneous view of the causes of the Great War, they can be used to discuss and analyse the importance of perspective in history, thus offering an opportunity to further a more disciplinary historical understanding.

  19. Small intestine contrast injection (image)

    Science.gov (United States)

    ... and throat, through the stomach into the small intestine. When in place, contrast dye is introduced and ... means of demonstrating whether or not the small intestine is normal when abnormality is suspected.

  20. 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.

  1. Contrast induced nephropathy in urology

    Directory of Open Access Journals (Sweden)

    Viji Samuel Thomson

    2009-01-01

    Full Text Available Intravenous contrast agents have a distinct role in urological imaging: to study precise anatomical delineation, vascularity, and to assess the function of the renal unit. Contrast induced nephropathy (CIN is a known adverse effect of intravenous contrast administration. The literature on incidence, pathophysiology, clinical features, and current preventive strategies available for CIN relevant to urologists was reviewed. A search of the PubMed database was done using the keywords nephropathy and media, prevention and control or prevention Contrast media (explode, all adverse effects, and kidney diseases (explode. An online search of the EMBASE database for the time ranging from 1977 to February 2009 was performed using the keywords ionic contrast medium, adverse drug reaction, major or controlled clinical study, human, nephrotoxicity, and kidney disease. Current publications and data most relevant to urologists were examined. CIN was the third most common cause of hospital-acquired renal failure. The incidence is less common with intravenous contrast administration as compared with intra-arterial administration. The pathogenesis of contrast mediated nephropathy is due to a combination of toxic injury to renal tubules and medullary ischemic injury mediated by reactive oxygen species. CIN most commonly manifests as a nonoliguric and asymptomatic transient decline in renal function. Patients who developed CIN were found to have increased mortality, longer hospital stay, and complicated clinical course. An overview of risk factors and risk prediction score for prognostication of CIN are elaborated. Preventive strategies including choice of contrast agents, maximum tolerated dose, role of hydration, hydration regime, etc. are discussed. The role of N- acetyl cysteine, Theophylline, Fenoldapam, Endothelin receptor antagonists, iloprost, atrial natriuretic peptide, and newer therapies such as targeted renal therapy (TRT are discussed. A working

  2. 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...

  3. Demographics of the European apicultural industry.

    Directory of Open Access Journals (Sweden)

    Marie-Pierre Chauzat

    Full Text Available 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

  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. Contrast-enhanced endoscopic ultrasonography

    Institute of Scientific and Technical Information of China (English)

    Nischita K Reddy; Ana Maria Ioncic(a); Adrian S(a)ftoiu; Peter Vilmann; Manoop S Bhutani

    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 sonography to depict tumor neovascularization can be increased by contrast agents.Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion.In the future,these techniques could potentially be used to quantify tumor perfusion,to assess and monitor the efficacy of antiangiogenic agents,to assist targeted drug delivery and allow molecular imaging.

  6. 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.

  7. 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.

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

    OpenAIRE

    Das Sudip; Chatterjee Tapas; Banerji G; Biswas Indranil

    2006-01-01

    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 sca...

  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. 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.

  11. Socio Demographic Factors Related to Smoking among Rural Adolescent

    Directory of Open Access Journals (Sweden)

    Farzana Islam Khan

    2014-07-01

    Full Text Available Background: Smoking is one of the leading preventable causes of premature death, disease, and disability. Adolescence is the period of physical, psychological and social maturation from childhood to adulthood and adolescent smoking is a continuous process which is related to many disease factors. Objective: To find out the factors related to smoking among rural adolescents. Materials and method: One hundred and fifty one male adolescent aged 13 to 19 years from rural areas were interviewed with a semi-structured questionnaire during January to June 2013, at Dhamrai Upazilla Health Complex, Savar, Dhaka, Bangladesh. The socio demographic details, smoking and depression history were recorded. The Center for Epidemiologic Studies Depression (CES-D Scale was used to measure the presence of depression. Smoking behavior was measured by a number of questions. Results: Mean(±SD age of the study subjects was 16.8(±1.9 years. Most of the respondents started smoking around the average age of 14.3 years. The study shows that 64% respondents were smokers. Among smokers 80% were influenced by their friends about smoking. Seventy eight percent of the smokers were suffering from depression while 22% of nonsmokers were depressed (p<0.001. Majority (72% of the issues of the smoker parents were smoker (p<0.5. Domestic violence (p<0.001 and stressful events in life (p<0.05 also played significant roles for smoking. Conclusion: Depression, parent smoking and peer smoking, domestic violence, and stressful life events are important factors to start smoking in rural adolescents.

  12. The Retrospective Evaluation of Childhood Psoriasis Clinically and Demographic Features

    Directory of Open Access Journals (Sweden)

    Ayşe Serap Karadağ

    2013-03-01

    Full Text Available Objective: This study was aimed to define the clinical and demographic findings of psoriasis in childhood. Methods: In this retrospective study, the data from 64 children with psoriasis admitted at the our dermatology clinic between January 2007 and January 2011 were included whose data were fully. Results: Of the patients, 37 (57.8% were boys and 27 (42.2% were girls. Mean age of the children was 10.08 ±3.98 years (3-16. In 10 (15% cases, a positive family history was detected. The most frequent localizations at onset were trunk (46.9%, scalp (28.1%, knee-elbow (10.9% and extremities (7.9%, respectively. The most commonly seen clinical types were plaque (68.8%, guttate (20.3%, palmoplantar (9.4%, pustular (1.6%, respectively. Nine children had nail involvement. Out of all patients, 21.9% had upper respiratory tract infections and 9.4% had emotional stres. Four cases were diagnosed with depression. Of the cases, two cases were on non-steroid anti-inflammatory medication, and 4 of them were on antibiotics. Systemic treatments were given to 21.9% of the cases besides topical treatments. Conclusion: The epidemiological studies of psoriasis during childhood period for different countries have been reported. In this study, the ratio shows differences when compared to those previous studies. There are few epidemiologic studies for Turkey. We believe that further epidemiological studies including large number of patients' groups will contribute the diagnosis and treatment of the disease.

  13. Dimensions of Delusions in Major Depression: Socio-demographic and Clinical Correlates in an Unipolar-Bipolar Sample.

    Science.gov (United States)

    Zaninotto, Leonardo; Souery, Daniel; Calati, Raffaella; Camardese, Giovanni; Janiri, Luigi; Montgomery, Stuart; Kasper, Siegfried; Zohar, Joseph; De Ronchi, Diana; Mendlewicz, Julien; Serretti, Alessandro

    2015-04-30

    The present study aims at exploring associations between a continuous measure of distorted thought contents and a set of demographic and clinical features in a sample of unipolar/bipolar depressed patients. Our sample included 1,833 depressed subjects. Severity of mood symptoms was assessed by the 21 items Hamilton Depression Rating Scale (HAM-D). The continuous outcome measure was represented by a delusion (DEL) factor, extracted from HAM-D items and including items: 2 ("Feelings of guilt"), 15 ("Hypochondriasis"), and 20 ("Paranoid symptoms"). Each socio-demographic and clinical variable was tested by a generalized linear model test, having depressive severity (HAM-D score?DEL score) as the covariate. A family history of major depressive disorder (MDD; p=0.0006), a diagnosis of bipolar disorder, type I ( p=0.0003), a comorbid general anxiety disorder (psocio-demographic or clinical variable was found to be associated to our continuous measure of distorted thinking in depression.

  14. 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.

  15. Treatment of Hidden Heterogeneity in Event History Analysis

    OpenAIRE

    1986-01-01

    In this paper we describe some statistical tools for event history analysis when there is unobserved heterogeneity of particular types as well as measured covariates. For expository purposes we also discuss several potential applications of these statistical methods. Actual application of these methods to demographic data remains as a goal for future work.

  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. Investigating European genetic history through computer simulations.

    Science.gov (United States)

    Currat, Mathias; Silva, Nuno M

    2013-01-01

    The genetic diversity of Europeans has been shaped by various evolutionary forces including their demographic history. Genetic data can thus be used to draw inferences on the population history of Europe using appropriate statistical methods such as computer simulation, which constitutes a powerful tool to study complex models. Here, we focus on spatially explicit simulation, a method which takes population movements over space and time into account. We present its main principles and then describe a series of studies using this approach that we consider as particularly significant in the context of European prehistory. All simulation studies agree that ancient demographic events played a significant role in the establishment of the European gene pool; but while earlier works support a major genetic input from the Near East during the Neolithic transition, the most recent ones revalue positively the contribution of pre-Neolithic hunter-gatherers and suggest a possible impact of very ancient demographic events. This result of a substantial genetic continuity from pre-Neolithic times to the present challenges some recent studies analyzing ancient DNA. We discuss the possible reasons for this discrepancy and identify future lines of investigation in order to get a better understanding of European evolution.

  18. The family and demographic change in Sri Lanka.

    Science.gov (United States)

    Caldwell, B

    1996-01-01

    Sri Lanka has almost completed the demographic transition with low mortality rates and fertility rates approaching replacement levels. Sri Lanka shares these characteristics with the South Indian states of Kerala and Tamil Nadu in contrast to elsewhere in South Asia where mortality and especially fertility rates remain much higher. A key part of the explanation for these differences lies in the nature of the family. The Sri Lankan family is essentially the conjugal unit of husband, wife and dependent children whereas in northern South Asia agnatic relations between son and parents are central to family structure. Related to this family system the position of women in Sri Lankan society was relatively high in South Asian terms. Consequently women had a strong say in health and fertility behaviour. When required, for example, mothers take the initiative in seeking health care for themselves and their children. Importantly family structure has facilitated female education which is associated with both mortality and fertility decline. There are few concerns that the values imparted by secular education are contrary to the values of the family or to women's roles within it. The egalitarian family structure has also contributed to fertility decline by raising the costs of children and reducing the long-run benefits to be gained from them. Sri Lanka is particularly distinctive in the contribution of changes in female age at marriage to its fertility decline, marriage age having risen six years this century. This change has been accompanied in recent times by a shift from family-arranged to self-selected (love) marriage. The explanation lies in changes in the socio-economic system which have reduced the centrality of the family in wider social and economic relations, and placed a greater premium on an individual's own abilities and attributes.

  19. 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.

  20. Demographic Estimation from Face Images: Human vs. Machine Performance.

    Science.gov (United States)

    Han, Hu; Otto, Charles; Liu, Xiaoming; Jain, Anil K

    2015-06-01

    Demographic estimation entails automatic estimation of age, gender and race of a person from his face image, which has many potential applications ranging from forensics to social media. Automatic demographic estimation, particularly age estimation, remains a challenging problem because persons belonging to the same demographic group can be vastly different in their facial appearances due to intrinsic and extrinsic factors. In this paper, we present a generic framework for automatic demographic (age, gender and race) estimation. Given a face image, we first extract demographic informative features via a boosting algorithm, and then employ a hierarchical approach consisting of between-group classification, and within-group regression. Quality assessment is also developed to identify low-quality face images that are difficult to obtain reliable demographic estimates. Experimental results on a diverse set of face image databases, FG-NET (1K images), FERET (3K images), MORPH II (75K images), PCSO (100K images), and a subset of LFW (4K images), show that the proposed approach has superior performance compared to the state of the art. Finally, we use crowdsourcing to study the human perception ability of estimating demographics from face images. A side-by-side comparison of the demographic estimates from crowdsourced data and the proposed algorithm provides a number of insights into this challenging problem.

  1. China's Demographic Challenge Requires an Integrated Coping Strategy

    Science.gov (United States)

    Peng, Xizhe

    2013-01-01

    China has entered into a new stage of demographic dynamics whereby population-related challenges are more complicated than ever before. The current one-child policy should be modified. However, the anticipated impacts of such a policy change should not be over-exaggerated. China's demographic challenge requires an integrated coping strategy.…

  2. Making the Case for Demographic Data in Extension Programming

    Science.gov (United States)

    Curtis, Katherine J.; Verdoff, Daniel; Rizzo, Bill; Beaudoin, James

    2012-01-01

    Understanding one's community is essential for effective Extension programming across all program areas. The use of current and reliable demographic data is crucial for Extension to develop effective education and programming to track change and to uncover hidden community characteristics. We discuss what demographic data are, present…

  3. Europe at the crossroads: demographic challenges and international migration

    NARCIS (Netherlands)

    van Nimwegen, N.; van der Erf, R.F.

    2010-01-01

    Two demographic challenges confront Europe today: population ageing and population decline. These challenges are two sides of the same demographic coin. While low fertility and increasing longevity cause populations to rapidly grow older, low fertility also leads to population decline. This paper de

  4. Developing a Global Mindset: Integrating Demographics, Sustainability, Technology, and Globalization

    Science.gov (United States)

    Aggarwal, Raj

    2011-01-01

    Business schools face a number of challenges in responding to the business influences of demographics, sustainability, and technology--all three of which are also the fundamental driving forces for globalization. Demographic forces are creating global imbalances in worker populations and in government finances; the world economy faces…

  5. Making the Case for Demographic Data in Extension Programming

    Science.gov (United States)

    Curtis, Katherine J.; Verdoff, Daniel; Rizzo, Bill; Beaudoin, James

    2012-01-01

    Understanding one's community is essential for effective Extension programming across all program areas. The use of current and reliable demographic data is crucial for Extension to develop effective education and programming to track change and to uncover hidden community characteristics. We discuss what demographic data are, present…

  6. The Impact of Extrinsic Demographic Factors on Cantonese Speech Acquisition

    Science.gov (United States)

    To, Carol K. S.; Cheung, Pamela S. P.; McLeod, Sharynne

    2013-01-01

    This study modeled the associations between extrinsic demographic factors and children's speech acquisition in Hong Kong Cantonese. The speech of 937 Cantonese-speaking children aged 2;4 to 6;7 in Hong Kong was assessed using a standardized speech test. Demographic information regarding household income, paternal education, maternal education,…

  7. Developing a Global Mindset: Integrating Demographics, Sustainability, Technology, and Globalization

    Science.gov (United States)

    Aggarwal, Raj

    2011-01-01

    Business schools face a number of challenges in responding to the business influences of demographics, sustainability, and technology--all three of which are also the fundamental driving forces for globalization. Demographic forces are creating global imbalances in worker populations and in government finances; the world economy faces…

  8. 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

  9. 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.

  10. 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....

  11. Microforms and Sport History.

    Science.gov (United States)

    Levine, Peter

    1986-01-01

    Explores the importance of sport history as it reflects the social and cultural history of the United States. Discussion covers the various sport history materials that are available in microform, including the Spalding Collection, twentieth-century microfilm sources, and sports and social history (Sports Periodicals microfilm series). (EJS)

  12. What Is Literary "History"?

    Science.gov (United States)

    Harris, Wendell V.

    1994-01-01

    Examines the meaning of the word "history" as used in the common phrase "literary history" by critics and scholars. Asserts the differences between historical scholarship and literary history. Argues that the grounding activity of literary history is insulated from the relativism insisted upon by poststructuralist theorizing.…

  13. Agency in Fertility Decisions in Western Europe During the Demographic Transition: A Comparative Perspective.

    Science.gov (United States)

    Reher, David Sven; Sandström, Glenn; Sanz-Gimeno, Alberto; van Poppel, Frans W A

    2017-02-01

    We use a set of linked reproductive histories taken from Sweden, the Netherlands, and Spain for the period 1871-1960 to address key issues regarding how reproductive change was linked specifically to mortality and survivorship and more generally to individual agency. Using event-history analysis, this study investigates how the propensity to have additional children was influenced by the number of surviving offspring when reproductive decisions were made. The results suggest that couples were continuously regulating their fertility to achieve reproductive goals. Families experiencing child fatalities show significant increases in the hazard of additional births. In addition, the sex composition of the surviving sibset also appears to have influenced reproductive decisions in a significant but changing way. The findings offer strong proof of active decision-making during the demographic transition and provide an important contribution to the literature on the role of mortality for reproductive change.

  14. Socio-demographic characteristics of cancer patients: Hospital based cancer registry in a tertiary care hospital of India

    Directory of Open Access Journals (Sweden)

    S Puri

    2014-01-01

    Full Text Available Aim: To determine the socio-demographic characteristics of cancer patients. Materials and Methods: Review of the Cancer registry, and patient interview. Information on socio-demographic profile, medical history, family history and previous treatment, if any, was retrieved from the patient. If the patient couldn′t be contacted then information was taken from pathology/radiotherapy or medical records department. Results: A total of 684 patients participated in the study. More than 40% of males and 53.7% of females were illiterate, P < 0.05. The majority (33.5% of participants were of low socioeconomic status. The most frequently reported cancer (ca in males it was ca lung (40.9 and ca oesophagus (9.8. In females most common cancer were ca breast (23.9 followed by ca cervix (11.7.

  15. 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.

  16. Subharmonic imaging of contrast agents.

    Science.gov (United States)

    Forsberg, F; Shi, W T; Goldberg, B B

    2000-03-01

    Ultrasound contrast agents promise to improve the sensitivity and specificity of diagnostic ultrasound imaging. It is of great importance to adapt ultrasound equipment for optimal use with contrast agents e.g., by exploiting the nonlinear properties of the contrast microbubbles. Harmonic imaging is one technique that has been extensively studied and is commercially available. However, harmonic imaging is associated with problems, due to second harmonic generation and accumulation within the tissue itself. Given the lack of subharmonic generation in tissue, one alternative is the creation of subharmonic images by transmitting at the fundamental frequency (fo) and receiving at the subharmonic (fo/2). Subharmonic imaging should have a much better lateral resolution and may be suitable for scanning deep-lying structures owing to the higher transmit frequency and the much smaller attenuation of scattered subharmonic signals. In this paper, we will review different aspects of subharmonic imaging including implementation, in-vitro gray-scale imaging and subharmonic aided pressure estimation.

  17. Adverse reactions to intravenous iodinated contrast media: a prospective study

    Directory of Open Access Journals (Sweden)

    Dhruv J. Modi

    2012-06-01

    Full Text Available Background: Adverse reactions to intravenous iodinated contrast media may be classified as general and organ-specific, such as contrast-induced nephrotoxicity. General adverse reactions may be sub classified into acute and delayed types. Acute general adverse reactions can range from transient minor reactions to life-threatening severe reactions. This study was done to determine clinical adverse effects of the iodinated contrast media. Methods: Data of 899 consecutive patients at C.U. Shah Medical College and Hospital, Surendranagar, who received sodium meglumine diatrizoate intravenous iodinated contrast media during the period of May 2011 to April 2012, were collected for any adverse drug reactions. Results: Out of 899, 189 patients developed adverse contrast reactions. The incidences of mild, moderate and severe adverse reactions were 19.47%, 1.33% and 0.28%, respectively. There were no differences in the incidence of adverse reactions according to gender (males 21.1%; females 20.7%; p= >0.05 or age (p= >0.05. The incidence of adverse reactions was significantly higher in patients with a history of previous reactions (50% than in those with no history (21.25%; p= <0.05. Conclusions: The skin was the most commonly affected site of reactions. In reactions, mild forms were more common compared to moderate and severe. [Int J Basic Clin Pharmacol 2012; 1(3.000: 211-215

  18. Retrospective Demographic Analysis of Patients Seeking Care at a Free University Chiropractic Clinic

    Science.gov (United States)

    Stevens, Gerald; Campeanu, Michael; Sorrento, Andrew T.; Ryu, Jiwoon; Burke, Jeanmarie

    2016-01-01

    Objective The purpose of this study was to describe the demographics, presenting complaints, and health history of new patients seeking treatment at a free chiropractic clinic within a university health center. Methods A retrospective analysis of patient files from 2008 to 2009 was performed for a free student chiropractic clinic in the Buffalo, NY, area. Demographics, presenting complaints, and health history of new patients seeking treatment were recorded. Results There were 343 new chiropractic patient files. Most patients were between the ages of 18 and 30 years (n = 304, 88%) with an almost equal distribution of men (n = 163, 48%) and women (n = 180, 52%). The patients were mostly single (n = 300, 87%). Patients self-reported that their case histories excluded a current medical diagnosis (n = 261, 76%), previous history of disease (n = 216, 63%), allergies (n = 240, 70%), previous surgical procedures (n = 279, 81%), and medication use (n = 250, 73%). The frequencies of spinal complaints were as follows: lumbar spine, n = 176 (51%); cervical spine, n = 78 (23%); and thoracic spine, n = 44 (13%). Maintenance care, headaches, and spine-related upper and lower extremities complaints accounted for the other 13% of patients treated. Half were chronic (n = 172, 50%), and a third were acute (n=108, 31%). Patients averaged 6 chiropractic visits, with 88% having 11 visits or less. Conclusion This study found that new patients seeking care at a free student chiropractic clinic within a university health center in the Buffalo area mainly consisted of young single adults, with chronic lumbar spine complaints with few comorbidities. PMID:27069428

  19. Long-term demographic decline and late glacial divergence in a Californian paleoendemic: Sequoiadendron giganteum (giant sequoia)

    OpenAIRE

    Dodd, Richard S.; DeSilva, Rainbow

    2016-01-01

    Mediterranean ecosystems comprise a high proportion of endemic taxa whose response to climate change will depend on their evolutionary origins. In the California flora, relatively little attention has been given to the evolutionary history of paleoendemics from a molecular perspective, yet they number among some of the world's most iconic plant species. Here, we address questions of demographic change in Sequoiadendron giganteum (giant sequoia) that is restricted to a narrow belt of groves in...

  20. Long‐term demographic decline and late glacial divergence in a Californian paleoendemic: Sequoiadendron giganteum (giant sequoia)

    OpenAIRE

    Dodd, Richard S.; DeSilva, Rainbow

    2016-01-01

    Abstract Mediterranean ecosystems comprise a high proportion of endemic taxa whose response to climate change will depend on their evolutionary origins. In the California flora, relatively little attention has been given to the evolutionary history of paleoendemics from a molecular perspective, yet they number among some of the world's most iconic plant species. Here, we address questions of demographic change in Sequoiadendron giganteum (giant sequoia) that is restricted to a narrow belt of ...

  1. Linking physiological approaches to marine vertebrate conservation: using sex steroid hormone determinations in demographic assessments.

    Science.gov (United States)

    Labrada-Martagón, Vanessa; Zenteno-Savín, Tania; Mangel, Marc

    2014-01-01

    Sex, age and sexual maturation are key biological parameters for aspects of life history and are fundamental information for assessing demographic changes and the reproductive viability and performance of natural populations under exploitation pressures or in response to environmental influences. Much of the information available on the reproductive condition, length at sexual maturity and sex determinations of endangered species has been derived from direct examination of the gonads in dead animals, either intentionally or incidentally caught, or from stranded individuals. However, morphological data, when used alone, do not provide accurate demographic information in sexually monomorphic marine vertebrate species (e.g. sharks, sea turtles, seabirds and cetaceans). Hormone determination is an accurate and non-destructive method that provides indirect information about sex, reproductive condition and sexual maturity of free-ranging individuals. Correlations between sex steroid concentrations and biochemical parameters, gonadal development and state, reproductive behaviour and secondary external features have been already demonstrated in many species. Different non-lethal approaches (e.g. surgical and mark-recapture procedures), with intrinsic advantages and disadvantages when applied on free-ranging organisms, have been proposed to asses sex, growth and reproductive condition. Hormone determination from blood samples will generate valuable additional demographic information needed for stock assessment and biological conservation.

  2. Due Diligence for Students - Geoscience Skills and Demographic Data for Career Planning

    Science.gov (United States)

    Keane, C. M.

    2001-05-01

    A major focus of the American Geological Institute's Human Resources program has been providing demographic and employment data so that students and mentors can better understand the dynamics of a career in the geosciences. AGI has a long history of collecting these data for the geoscience community, including 46 years of geoscience enrollments, periodic comprehensive surveys of employment in the discipline, and working closely with other organizations that collect these data. AGI has launched a new suite of surveys to examine the skills desired by employers and the skills provided through a geoscience education. Historical demographic and enrollment data allow a number of the major trends to be examined. These trends include the dominance of industry as employer in the geosciences and how the cyclicity of geoscience employment has become more complex with the development of the environmental sector over the last 30 years. Additionally, demographics are changing rapidly, with a geoscience workforce that is changing rapidly in age, gender, and background. The discipline may also be facing a change in the nature of geoscience employment, with chronic shortages of skilled geoscientists, but will job opportunities actually increase. This may not be as paradoxical as it appears. The geoindustries are attempting to adjust their strategies to dampen business cycles, which then may lead to more stable employment levels for geoscientists, but they are also broadening their vision of who can become competent geoscientists.

  3. Demographic and historical backgrounds of the elderly with nonepileptic seizures: A comparative study

    Directory of Open Access Journals (Sweden)

    Acar Goksemin

    2010-01-01

    Full Text Available Background : Non-epileptic seizures (NES are not infrequent in the elderly. However, the data on NES in the elderly is likited. Aim : To study the demographic and historical background of eldely patients with NES and compare the same with the data in the younger patients with NES. Materials and Methods : Patients with NES over 55 years of age and the next two consecutive patients with NES between ages 18 and 45 were compared in terms of demographic and historical features, psychiatric evaluation and MMPI testing. Results : Of all the 128 patients with NES, 13 (10.6% were over 55 years of age. History of physical/sexual abuse was high in both the groups. The mean length of time for NES diagnosis was longer in the elderly (13.38 ± 15.33 vs. 6.15 ± 8.04 years; P < 0.05. Majority of the patients with NES were on AEDs without evidence of epilepsy and almost half in both the groups were using benzodiazepines. Conclusion : In demographic and historical aspects old and young patients do not display major differences; however, the diagnosis is significantly delayed in the elderly. Early diagnosis with video EEG is recommended to avoid potential long-term risks associated with inappropriate treatments.

  4. The Relationship between Demographic Factors and Substance Craving Among Drug-Dependents

    Directory of Open Access Journals (Sweden)

    F PoorSeyedMousaiee

    2015-03-01

    Full Text Available Objective: This study was conducted with the aim of examining the role of demographic factors such as age, marital status, education degree, the age of initiating addiction, duration of addiction, monthly cost of drug use, and an incarceration history in the intensity of addicts’ craving for substance use. Method: In this descriptive and cross-sectional study, 195 male addicts, after being interviewed, were selected as the participants of the study via convenience sampling method. They constituted six groups of opium smokers, heroin inhalers, heroin smokers, heroin injectors, methamphetamine smokers, and crack smokers and answered the questions of demographic characteristics and Franken’s desire for drug questionnaire. Indeed, substance craving of the respondents was measured by the computerized test of measuring visual indicators of substance craving. Results: The results showed that there is a significant positive relationship between education degree and induced substance craving, monthly cost of drug use and induced substance craving, and also between education degree and instantaneous substance craving. Conclusion: Some demographic factors can be important factors in predicting substance craving in addicts, which is, in itself, among the significant dimensions in treatment process.

  5. 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.

  6. A History of Until

    CERN Document Server

    Masini, Andrea; Volpe, Marco

    2009-01-01

    Until is a notoriously difficult temporal operator as it is both existential and universal at the same time: A until B holds at the current time instant w iff either B holds at w or there exists a time instant w' in the future at which B holds and such that A holds in all the time instants between the current one and w'. This "ambivalent" nature poses a significant challenge when attempting to give deduction rules for until. In this paper, in contrast, we make explicit this duality of until to provide well-behaved natural deduction rules for linear-time logics by introducing a new temporal operator that allows us to formalize the "history" of until, i.e., the "internal" universal quantification over the time instants between the current one and w'. This approach provides the basis for formalizing deduction systems for temporal logics endowed with the until operator. For concreteness, we give here a labeled natural deduction system for a linear-time logic endowed with the new operator and show that, via a prop...

  7. The history of AIDS exceptionalism

    Directory of Open Access Journals (Sweden)

    Smith Julia H

    2010-12-01

    Full Text Available Abstract In the history of public health, HIV/AIDS is unique; it has widespread and long-lasting demographic, social, economic and political impacts. The global response has been unprecedented. AIDS exceptionalism - the idea that the disease requires a response above and beyond "normal" health interventions - began as a Western response to the originally terrifying and lethal nature of the virus. More recently, AIDS exceptionalism came to refer to the disease-specific global response and the resources dedicated to addressing the epidemic. There has been a backlash against this exceptionalism, with critics claiming that HIV/AIDS receives a disproportionate amount of international aid and health funding. This paper situations this debate in historical perspective. By reviewing histories of the disease, policy developments and funding patterns, it charts how the meaning of AIDS exceptionalism has shifted over three decades. It argues that while the connotation of the term has changed, the epidemic has maintained its course, and therefore some of the justifications for exceptionalism remain.

  8. Theorizing Content: Tools from Cultural History

    Science.gov (United States)

    Hawkey, Kate

    2007-01-01

    What lies behind the lack of theorizing about content in history in contrast to much greater attention given to theorizing about children's developing understanding of historical skills and processes? Egan's model of the characteristic ways in which children of different ages engage with the world is used to raise the question of what content to…

  9. TEENAGE PREGNANCY: DEMOGRAPHICS, MATERNAL AND FOETAL OUTCOME

    Directory of Open Access Journals (Sweden)

    Radhika Gollapudi

    2016-08-01

    Full Text Available BACKGROUND Pregnancy though is a physiological event in a woman’s life, it has its own associated complications. In teenage pregnancies, the physical and emotional state of stress coupled with biological immaturity leads to adverse effect both on the health of the mother and the foetus. METHODS This study is a clinical prospective study analysing the demographics, maternal health issues and the foetal outcome in teenage pregnancies. The study was conducted over a period of one year at a government tertiary care center. Pregnant women in the age group of 13-19 years who delivered during the study period were included in the study group. All pregnant women over 20 years of age who delivered during the same period were taken as control group. Women who had medical disorders complicating pregnancy were excluded from the study. Anaemia, pregnancy induced hypertension, antepartum haemorrhage and mode of delivery were the maternal outcomes that were noted. Intrauterine growth retardation, prematurity, low birth weight, APGAR score were analysed with respect to the foetus. RESULTS In this study, the total number of pregnant women who delivered during the study period were 4782, 536 were teenage mothers, constituting 11.2% of the total pregnancies. Of the 536 teenage mothers, 69.78% belonged to the rural areas and 71.64% were found to have inadequate antenatal visits to the hospital. The mean age of teenage pregnancy was 17.18 years. Incidence of anaemia was 44.2% in comparison, the control group had an incidence of 33.02%. In our study, incidence of Pregnancy induced hypertension was 18.64% in teenage mothers and 10.6% in non-teenage mothers. The incidence of Antepartum Haemorrhage in our study was 8.94% in teenage mothers. Incidence of lower segment caesarean section was 22.76% in the teenage group as compared to 14.57% in the non-teenage group. In our study, 13.05% of teenage mothers had preterm deliveries as compared to 6.40% of non-teenage mothers

  10. Hominin life history: reconstruction and evolution.

    Science.gov (United States)

    Robson, Shannen L; Wood, Bernard

    2008-04-01

    In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables, traits such as weaning, age at sexual maturity, and life span, from life history-related variables such as body mass, brain growth, and dental development. The latter are either linked with, or can be used to make inferences about, life history, thus providing an opportunity for estimating life history parameters in fossil taxa. We compare the life history variables of modern great apes and identify traits that are likely to be shared by the last common ancestor of Pan-Homo and those likely to be derived in hominins. All great apes exhibit slow life histories and we infer this to be true of the last common ancestor of Pan-Homo and the stem hominin. Modern human life histories are even slower, exhibiting distinctively long post-menopausal life spans and later ages at maturity, pointing to a reduction in adult mortality since the Pan-Homo split. We suggest that lower adult mortality, distinctively short interbirth intervals, and early weaning characteristic of modern humans are derived features resulting from cooperative breeding. We evaluate the fidelity of three life history-related variables, body mass, brain growth and dental development, with the life history parameters of living great apes. We found that body mass is the best predictor of great ape life history events. Brain growth trajectories and dental development and eruption are weakly related proxies and inferences from them should be made with caution. We evaluate the evidence of life history-related variables available for extinct species and find that prior to the transitional hominins there is no evidence of any hominin taxon possessing a body size, brain size or aspects of dental development much different from what we assume to be the primitive life history pattern for the Pan-Homo clade. Data for

  11. Inferences of Recent and Ancient Human Population History Using Genetic and Non-Genetic Data

    Science.gov (United States)

    Kitchen, Andrew

    2008-01-01

    I have adopted complementary approaches to inferring human demographic history utilizing human and non-human genetic data as well as cultural data. These complementary approaches form an interdisciplinary perspective that allows one to make inferences of human history at varying timescales, from the events that occurred tens of thousands of years…

  12. Restless Legs Syndrome in an Appalachian Primary Care Population: Prevalence, Demographic and Lifestyle Correlates, and Burden

    Science.gov (United States)

    Innes, Kim E.; Flack, Kathryn L.; Selfe, Terry Kit; Kandati, Sahiti; Agarwal, Parul

    2013-01-01

    Background: Restless legs syndrome (RLS) is a common and distressing sensorimotor disorder of unknown etiology. While the epidemiology of RLS has been examined in several North American and European studies, research on RLS and RLS burden in poor, rural populations, including those residing in Appalachia, remains sparse. In this study, we investigated RLS prevalence in an Appalachian primary care population and examined the association of RLS to demographic factors, lifestyle characteristics, sleep quality, and mood disorders. Methods: Participants of this anonymous survey study were community-dwelling adults aged ≥ 18 years visiting one of 4 West Virginia primary care clinics. Data gathered included detailed information on sleep patterns, demographic characteristics, lifestyle factors, and health/medical history; the survey also included questions specific to RLS diagnosis and severity. Response rates were excellent, with 68% of eligible adults contacted returning completed surveys (N = 1,424/2,087). Pregnant women (N = 65) and those with missing data on key variables (N = 142) were excluded from the analyses. Results: Of the 1,217 participants included in the final analytic sample, 19.6% (18.2% with symptoms at least once/month) met the 4 IRLSSG diagnostic criteria in the absence of positional discomfort or leg cramps; 14.5% reported RLS symptoms at least once/week and 10.1% indicated symptoms ≥ 3×/week. Excluding respondents with diabetes, kidney disease, or anemia reduced these rates only slightly. Those with RLS were more likely to be older, female, lower income, unemployed, disabled, non-Hispanic white, and less likely to be college educated than those without RLS. Mood and sleep impairment were significantly elevated in those with RLS; after adjustment for demographic and lifestyle characteristics, health history, and other factors, those with RLS remained significantly more likely to indicate a history of depression (adjusted odds ratio [OR] = 1.9; 95

  13. Influence of harvesting pressure on demographic tactics: Implications for wildlife management

    Science.gov (United States)

    Servanty, S.; Gaillard, J.-M.; Ronchi, F.; Focardi, S.; Baubet, E.; Gimenez, O.

    2011-01-01

    Demographic tactics within animal populations are shaped by selective pressures. Exploitation exerts additional pressures so that differing demographic tactics might be expected among populations with differences in levels of exploitation. Yet little has been done so far to assess the possible consequences of exploitation on the demographic tactics of mammals, even though such information could influence the choice of effective management strategies. Compared with similar-sized ungulate species, wild boar Sus scrofa has high reproductive capabilities, which complicates population management. Using a perturbation analysis, we investigated how population growth rates (??) and critical life-history stages differed between two wild boar populations monitored for several years, one of which was heavily harvested and the other lightly harvested. Asymptotic ?? was 1??242 in the lightly hunted population and 1??115 in the heavily hunted population, while the ratio between the elasticity of adult survival and juvenile survival was 2??63 and 1??27, respectively. A comparative analysis including 21 other ungulate species showed that the elasticity ratio in the heavily hunted population was the lowest ever observed. Compared with expected generation times of similar-sized ungulates (more than 6years), wild boar has a fast life-history speed, especially when facing high hunting pressure. This is well illustrated by our results, where generation times were 3??6years in the lightly hunted population and only 2??3years in the heavily hunted population. High human-induced mortality combined with non-limiting food resources accounted for the accelerated life history of the hunted population because of earlier reproduction. Synthesis and applications. For wild boar, we show that when a population is facing a high hunting pressure, increasing the mortality in only one age-class (e.g. adults or juveniles) may not allow managers to limit population growth. We suggest that simulations of

  14. Contrast-enhanced endoscopic ultrasonography

    DEFF Research Database (Denmark)

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

  15. Socio-demographic correlates of fear of crime and the social context of contemporary urban China.

    Science.gov (United States)

    Liu, Jianhong; Messner, Steven F; Zhang, Lening; Zhuo, Yue

    2009-09-01

    Previous research in the West has established major socio-demographic correlates of fear of crime. The interpretation of these correlates is typically based on the concept of physical or social vulnerability of individuals. These correlates are implicitly regarded as invariant to social or community contexts, reflecting universal human behavioral patterns. The present study argues that social change may alter patterns of perceptions associated with fear among socio-demographic groups, thus affecting socio-demographic correlates of fear of crime. We explore how social changes in China have created a generational gap that influences the effects of age and education on fear of crime. The study finds that, in contrast with the well-established patterns in Western communities, the young and educated exhibit a higher level of fear of crime in urban China than their counterparts. The study also finds that consistent with Western literature, females are fearful and that personal victimization experience increases the level of fear. We discuss the social and community processes that produce these interesting patterns.

  16. Multilocus Analyses Reveal Postglacial Demographic Shrinkage of Juniperus morrisonicola (Cupressaceae), a Dominant Alpine Species in Taiwan.

    Science.gov (United States)

    Huang, Chi-Chun; Hsu, Tsai-Wen; Wang, Hao-Ven; Liu, Zin-Huang; Chen, Yi-Yen; Chiu, Chi-Te; Huang, Chao-Li; Hung, Kuo-Hsiang; Chiang, Tzen-Yuh

    2016-01-01

    Postglacial climate changes alter geographical distributions and diversity of species. Such ongoing changes often force species to migrate along the latitude/altitude. Altitudinal gradients represent assemblage of environmental, especially climatic, variable factors that influence the plant distributions. Global warming that triggered upward migrations has therefore impacted the alpine plants on an island. In this study, we examined the genetic structure of Juniperus morrisonicola, a dominant alpine species in Taiwan, and inferred historical, demographic dynamics based on multilocus analyses. Lower levels of genetic diversity in north indicated that populations at higher latitudes were vulnerable to climate change, possibly related to historical alpine glaciers. Neither organellar DNA nor nuclear genes displayed geographical subdivisions, indicating that populations were likely interconnected before migrating upward to isolated mountain peaks, providing low possibilities of seed/pollen dispersal across mountain ranges. Bayesian skyline plots suggested steady population growth of J. morrisonicola followed by recent demographic contraction. In contrast, most lower-elevation plants experienced recent demographic expansion as a result of global warming. The endemic alpine conifer may have experienced dramatic climate changes over the alternation of glacial and interglacial periods, as indicated by a trend showing decreasing genetic diversity with the altitudinal gradient, plus a fact of upward migration.

  17. Demographic characteristics and ocular involvement in Behçet patients in Southeast Anatolia

    Directory of Open Access Journals (Sweden)

    Fatih Mehmet Türkcü

    2013-09-01

    Full Text Available Objective: The aim of this study was to evaluate the demographiccharacteristics of Behcet’s disease (BD patientswith and without ocular involvement.Methods: In this retrospective study BD patients followedup between 2009 and 2013 years in ophthalmology anddermatology clinics were reviewed. Patients were dividedinto 2 groups according to the ocular involvement asocular or non-ocular BD. For each patient, age of onset,gender, family history, and systemic involvement were examined.The frequency of these data was analyzed.Results: Of the 295 patients 177 were ocular BD and 118were non-ocular BD. Ocular involvement were seen morefrequently in male patients than in females. There wasno change between the groups in terms of age at onsetof the disease, a history of thrombophlebitis or gastrointestinal,pulmonary and joint involvement. Pathergy testpositivity and the presence of genital ulcers had more frequentin non-ocular BD.Conclusion: In this study clinical and demographic characteristicsof ocular and non-ocular BD patients in theSoutheast Anatolian Region of Turkey were presented. Asimilar study was not performed previously in our regiontherefore we believe that those data will be useful for diagnosisand follow-up of BD patients. J Clin Exp Invest2013; 4 (3: 339-342Key words: Behçet disease, eye involvement, demographic characteristics

  18. Detecting the Evolution of Deliberate Fertility Control before the Demographic Transition in Germany

    Directory of Open Access Journals (Sweden)

    Aliaksandr Amialchuk

    2012-10-01

    Full Text Available BACKGROUND Pervious literature has established the existence of deliberate non-parity-specific fertility control in pre-transitional populations. However, less focus has been given to the timing of its onset. In addition, previous studies focused on the changes in fertility in response to the local prices of grains, which may be endogenous. OBJECTIVE This paper studies the emergence and evolution of deliberate fertility control by investigating the link between child mortality and economic stress on the one hand and non-parity-specific birth control on the other, in historic German villages between 1700 and 1900. METHODS Birth histories from fourteen German villages (1700-1900 and rye price series are used in a micro-level event history analysis. The fertility response of second and higher-order births to the mortality of children over age two and exogenous fluctuations in rye price are used as measures of the extent of deliberate non-parity-specific birth control. RESULTS Over the course of the demographic transition, the effect of the death of children generally increases after controlling for the effect of the death of children less than two years old. The negative fertility response to high rye prices before and in the year immediately following the price change occurred only after 1800. CONCLUSIONS The replacement and insurance effects associated with child mortality generally increased before the demographic transition. The emergence of the negative effect of high rye prices on fertility after 1800 further supports the presence and evolution of deliberate non-parity-specific fertility control before the demographic transition.

  19. Density-dependent coral recruitment displays divergent responses during distinct early life-history stages.

    Science.gov (United States)

    Doropoulos, Christopher; Evensen, Nicolas R; Gómez-Lemos, Luis A; Babcock, Russell C

    2017-05-01

    Population growth involves demographic bottlenecks that regulate recruitment success during various early life-history stages. The success of each early life-history stage can vary in response to population density, interacting with intrinsic (e.g. behavioural) and environmental (e.g. competition, predation) factors. Here, we used the common reef-building coral Acropora millepora to investigate how density-dependence influences larval survival and settlement in laboratory experiments that isolated intrinsic effects, and post-settlement survival in a field experiment that examined interactions with environmental factors. Larval survival was exceptionally high (greater than 80%) and density-independent from 2.5 to 12 days following spawning. By contrast, there was a weak positive effect of larval density on settlement, driven by gregarious behaviour at the highest density. When larval supply was saturated, settlement was three times higher in crevices compared with exposed microhabitats, but a negative relationship between settler density and post-settlement survival in crevices and density-independent survival on exposed surfaces resulted in similar recruit densities just one month following settlement. Moreover, a negative relationship was found between turf algae and settler survival in crevices, whereas gregarious settlement improved settler survival on exposed surfaces. Overall, our findings reveal divergent responses by coral larvae and newly settled recruits to density-dependent regulation, mediated by intrinsic and environmental interactions.

  20. Correlation between demographic characteristics, cognitive functioning and functional independence in stroke patients

    Directory of Open Access Journals (Sweden)

    Arsić Slađana

    2016-01-01

    Full Text Available Introduction. It has been assumed that there is causality of the achieved level of functional independence with the degree of preservation of cognitive function in stroke patients. Demographic characteristics may be important for monitoring the achieved level of functional independence. Objective. The aim of this study was to examine the relationship of demographic characteristics and functional independence in regard to the level of cognitive impairment in stroke patients. Methods. The study included 50 stroke patients after rehabilitation, as well as age- and gender-matched 50 subjects selected randomly, according to the demographic characteristics of the studied sample, who in their medical history had no neurological disorders. For the assessment of functional independence, the Functional Independence Measure (FIM test was used. The general cognition was estimated by the Mini-Mental State Examination (MMSE test. The statistical analyses included the Mann-Whitney test, for two independent samples, measures of canonical correlation, and χ2 test. Results. There was a statistically significant difference between the groups in relation to risk factors, hypertension and diabetes mellitus type II (p<0.001; There was a statistically significant difference within the groups in relation to the cognitive impairment in all the examined demographic characteristics (p<0.001; the differences within the groups in relation to the cognitive impairment are present on all subscales of the FIM test (p<0.05; the differences within the groups in relation to handedness, hemiparesis, show that mild cognitive impairment is more common among left hemiparesis, while a more severe one is more common among right-sided hemiparesis (p<0.05; More severe cognitive impairment is common among women, the elderly and in persons with lower education (p<0.05. Conclusion. By prevention of risk factors, and prevention of possible cognitive impairment, consequences of stroke can be

  1. DEMOGRAPHIC PROFILE OF PEDIATRIC OSTEOSARCOMA IN SOUTH INDIA: A SINGLE INSTITUTION EXPERIENCE

    Directory of Open Access Journals (Sweden)

    Ashok S Komaranchath, L. Appaji, K. C. Lakshmaiah, Mangesh Kamath, Rekha V Kumar

    2015-07-01

    Full Text Available INTRODUCTION: Osteosarcoma is the most common primary malignant bone tumor in children and adolescents, accounting for 4% of all childhood cancers worldwide. In India, the incidence varies from 4.7% to 11.6%, where this malignancy is associated with significant morbidity and mortality. There is paucity of demographic and clinical data for osteosarcoma in India. Objective: To retrospectively assess the demographic and clinical profile of pediatric osteosarcoma presenting at a tertiary cancer care centre of South India. Materials and Methods: From January 2010 to December 2013, all children under the age of 15 years diagnosed with osteosarcoma on histopathology were retrospectively analyzed for age, gender, rural or urban location, history, location of tumour, investigations, stage and histopathological subtype. The findings were formulated to chart the demographic and clinical profile. Results: A total of 37 cases of pediatric osteosarcoma were analyzed. The median age was 13 years with only three patients under the age of 10 years. There was a slight female preponderance with male: female ratio of 1:1.3. Most common mode of presentation was with pain and swelling of local site. Three patients had presented with a pathological fracture. The most common site involved was the distal femur. Over 90% of the cases were conventional osteosarcoma. Around 32% of patients had stage IV disease at presentation. Around 37% of patients from rural areas and 20% of patients from urban areas presented with metastatic disease. Conclusions: The aim of the study was the demographic and clinical description of osteosarcoma in the pediatric age group. A slight female preponderance was noted. The most common sites were consistent with western data except for an increased incidence in the fibula. There was an increased incidence of metastatic disease as compared to western population and a larger proportion of these patients seemed to come from rural areas.

  2. The age demographics of academic librarians a profession apart

    CERN Document Server

    Wilder, Stanley

    2013-01-01

    The Age Demographics of Academic Librarians: A Profession Apart discusses the current demographics of librarianship in North America and examines how a huge retiree rate will affect the profession. With the average age of librarians increasing dramatically since 1990, this book examines the changes that will have to take place in your library, such as recruiting, training, and working with a smaller staff. The Age Demographics of Academic Librarians provides you with insights on how to make your library's transition easier when several of your colleagues leave your library. Valuable and intell

  3. Investigating diet and physical activity in Malaysia: education and family history of diabetes relate to lower levels of physical activity

    National Research Council Canada - National Science Library

    Tam, Cai Lian; Bonn, Gregory; Yeoh, Si Han; Wong, Chee Piau

    2014-01-01

    .... Knowledge of diabetes, health locus of control, diet and exercise habits, as well as family history, education level and other demographic factors to better understand the correlates of risky and healthy behaviors...

  4. Disentangling the effects of evolutionary, demographic, and environmental factors influencing genetic structure of natural populations: Atlantic herring as a case study

    DEFF Research Database (Denmark)

    Gaggiotti, Oscar E.; Bekkevold, Dorte; Jørgensen, Hanne B.H.;

    2009-01-01

    carried out separate analyses of neutral and selected genetic variation, which allowed us to establish that the two most important factors affecting population structure were selection due to salinity at spawning sites and feeding migrations. The genetic signal left by the demographic history of herring...

  5. Evaluating vegetation effects on animal demographics: the role of plant phenology and sampling bias.

    Science.gov (United States)

    Gibson, Daniel; Blomberg, Erik J; Sedinger, James S

    2016-04-24

    Plant phenological processes produce temporal variation in the height and cover of vegetation. Key aspects of animal life cycles, such as reproduction, often coincide with the growing season and therefore may inherently covary with plant growth. When evaluating the influence of vegetation variables on demographic rates, the decision about when to measure vegetation relative to the timing of demographic events is important to avoid confounding between the demographic rate of interest and vegetation covariates. Such confounding could bias estimated effect sizes or produce results that are entirely spurious. We investigated how the timing of vegetation sampling affected the modeled relationship between vegetation structure and nest survival of greater sage-grouse (Centrocercus urophasianus), using both simulated and observational data. We used the height of live grasses surrounding nests as an explanatory covariate, and analyzed its effect on daily nest survival. We compared results between models that included grass height measured at the time of nest fate (hatch or failure) with models where grass height was measured on a standardized date - that of predicted hatch date. Parameters linking grass height to nest survival based on measurements at nest fate produced more competitive models, but slope coefficients of grass height effects were biased high relative to truth in simulated scenarios. In contrast, measurements taken at predicted hatch date accurately predicted the influence of grass height on nest survival. Observational data produced similar results. Our results demonstrate the importance of properly considering confounding between demographic traits and plant phenology. Not doing so can produce results that are plausible, but ultimately inaccurate.

  6. High-contrast imaging testbed

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K; Silva, D; Poyneer, L; Macintosh, B; Bauman, B; Palmer, D; Remington, T; Delgadillo-Lariz, M

    2008-01-23

    Several high-contrast imaging systems are currently under construction to enable the detection of extra-solar planets. In order for these systems to achieve their objectives, however, there is considerable developmental work and testing which must take place. Given the need to perform these tests, a spatially-filtered Shack-Hartmann adaptive optics system has been assembled to evaluate new algorithms and hardware configurations which will be implemented in these future high-contrast imaging systems. In this article, construction and phase measurements of a membrane 'woofer' mirror are presented. In addition, results from closed-loop operation of the assembled testbed with static phase plates are presented. The testbed is currently being upgraded to enable operation at speeds approaching 500 hz and to enable studies of the interactions between the woofer and tweeter deformable mirrors.

  7. 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.

  8. low birthweight babies: socio-demographic and obstetric ...

    African Journals Online (AJOL)

    2002-10-01

    Oct 1, 2002 ... mothers (aged below 20 years) and older mothers of low birthweight ( ... have unfavourable socio-demographic and obstetric factors like ... having less formal education, being unemployed and having obstetric risks for poor.

  9. Evaluation of Demographic Variables and Socio-economic Status ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Evaluation of Demographic Variables and Socio-economic Status on the Prevalence of. Health Hazards ... management provide food and harbourage for rodents, mosquitoes .... were factors influencing solid waste management in. Abeokuta.

  10. Demographic profile and epidemiology of injury in Mthatha, South ...

    African Journals Online (AJOL)

    EB

    1997-01-01

    Jan 1, 1997 ... Demographic profile and epidemiology of injury in Mthatha, South. Africa. Dhaffala A1 ... Department of Surgery, Walter Sisulu University, Mthatha, South Africa,. 2. Faculty of Health ..... of concern in nursing science. J Nurs ...

  11. Regional Differentiation of The Demographic Potential in Italy and Poland

    Directory of Open Access Journals (Sweden)

    Pastuszka Sławomir

    2017-09-01

    Full Text Available The aim of this paper is to compare the demographic potential of given Italian and Polish regions. The analysis shows that the demographic situation in Poland, unlike in Italy, is not directly related to the level of development of some regions and their geographical location. In Italy, the unfavorable demographic situation is typical of most of the less-developed southern regions, whereas in Poland it occurs in voivodships with different economic potential, situated in different parts of the country. This is probably the result of the current polycentric development of Poland, characteristic of a centralized economy, and the polar development in Italy. Certain demographic similarities, but of different levels, related to the dynamics of the population, the level of fertility, and net migration are observable in the macro-regions of Mezzogiorno and Eastern Poland.

  12. Socio-demographic determinants of the knowledge of diabetes ...

    African Journals Online (AJOL)

    Socio-demographic determinants of the knowledge of diabetes mellitus in Onitsha-North Local Government Area, Anambra State, ... Open Access DOWNLOAD FULL TEXT ... The instrument used for the collection of data was self-administered ...

  13. Customers Demographics Influence on Usage of Retail Banking Channels

    Directory of Open Access Journals (Sweden)

    Neha GUPTA

    2016-09-01

    Full Text Available The study presents the usage of retail banking influenced by customers’ demographics of selected Public Sector Banks (PSBs of India. The study was based on primary data collected through structured questionnaire. The simple random sampling technique used for data collection for sample size 692. The study finds that public sector banks need to understand the usage pattern of an individual customer using delivery channel to add greater value to customers. Respondent age groups influence ATMs usage. Internet banking is majorly influenced by the customers’ demographics. Respondents’ age group and qualification influence mobile banking. Branch lobby kiosk is not influenced by any demographics. The identification of most influential demographic variable will help to build strong and effective cross-selling and up-selling of financial products and services. Our study was limited to the customers of PSBs of India. This study may be helpful to PSBs for enhancing effective usage of delivery channels.

  14. EnviroAtlas - Green Bay, WI - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  15. EnviroAtlas - Fresno, CA - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  16. EnviroAtlas - New Haven, CT - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  17. Socio-Demographic Factors Influencing Work-Role Salience Among ...

    African Journals Online (AJOL)

    Socio-Demographic Factors Influencing Work-Role Salience Among ... The findings showed that students from lower socio-economic status homes and those ... The need to involve the students\\' parents in career education programmes and ...

  18. China’s grave demographic challenges in coming decades

    Institute of Scientific and Technical Information of China (English)

    任强; 郑晓瑛

    2009-01-01

    This paper systematically analyzes the uncertainties of major demographic indicators from China’s 2000 census,such as fertility,gender ratio at birth,and age structure,and through a probability demographic forecast gives an assessment of the situation facing the country.Research outcomes suggest that great differences exist in the estimate of China’s fertility,gender ratio at birth and low-age child population.These differences directly affect China’s current and future demographic uncertainties,and have implications for policy and future research.The demographic uncertainties caused by current conditions are of great value to decision-makers and the public alike.

  19. Political demography: Powerful trends under-attended by demographic science.

    Science.gov (United States)

    Teitelbaum, Michael S

    2015-01-01

    The interconnections between politics and the dramatic demographic changes under way around the world have been neglected by the two research disciplines that could contribute most to their understanding: demography and political science. Instead, this area of 'political demography' has largely been ceded to political activists, pundits, and journalists, leading often to exaggerated or garbled interpretation. The terrain includes some of the most politically sensitive and contested issues: alleged demographically determined shifts in the international balance of power; low fertility, population decline, and demographic ageing; international migration; change in national identity; and compositional shifts in politically sensitive social categories and human rights. Meanwhile many governments and non-governmental actors have actively pursued varieties of 'strategic demography', deploying fertility, mortality, or migration as instruments of domestic or international policy. Political scientists and demographers could and should use their knowledge and analytic techniques to improve understanding and to moderate excessive claims and fears on these topics.

  20. Gender in Science and Engineering Faculties: Demographic Inertia Revisited.

    Directory of Open Access Journals (Sweden)

    Nicole R Thomas

    Full Text Available The under-representation of women on faculties of science and engineering is ascribed in part to demographic inertia, which is the lag between retirement of current faculty and future hires. The assumption of demographic inertia implies that, given enough time, gender parity will be achieved. We examine that assumption via a semi-Markov model to predict the future faculty, with simulations that predict the convergence demographic state. Our model shows that existing practices that produce gender gaps in recruitment, retention, and career progression preclude eventual gender parity. Further, we examine sensitivity of the convergence state to current gender gaps to show that all sources of disparity across the entire faculty career must be erased to produce parity: we cannot blame demographic inertia.

  1. Gender in Science and Engineering Faculties: Demographic Inertia Revisited.

    Science.gov (United States)

    Thomas, Nicole R; Poole, Daniel J; Herbers, Joan M

    2015-01-01

    The under-representation of women on faculties of science and engineering is ascribed in part to demographic inertia, which is the lag between retirement of current faculty and future hires. The assumption of demographic inertia implies that, given enough time, gender parity will be achieved. We examine that assumption via a semi-Markov model to predict the future faculty, with simulations that predict the convergence demographic state. Our model shows that existing practices that produce gender gaps in recruitment, retention, and career progression preclude eventual gender parity. Further, we examine sensitivity of the convergence state to current gender gaps to show that all sources of disparity across the entire faculty career must be erased to produce parity: we cannot blame demographic inertia.

  2. socio-demographic factors in under five children with acute ...

    African Journals Online (AJOL)

    2013-09-01

    Sep 1, 2013 ... Their socio-demographic factors such as age, sex, breastfeeding status, parents ... acute diarrhoea among under five children in Enugu, Nigeria. ... Malnutrition predisposes .... Determinants of the utilization of children's Health.

  3. EnviroAtlas - Phoenix, AZ - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  4. Demographic Trends (1970-2010) for Coastal Geographies

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Demographic Trends (1970-2010) were derived from Census Block Group Data for 13 different coastal geographies. For a full listing of the geographies available,...

  5. EnviroAtlas - Portland, OR - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  6. EnviroAtlas - Des Moines, IA - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  7. EnviroAtlas - Paterson, NJ - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  8. EnviroAtlas - Memphis, TN - Demographics by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is a summary of key demographic groups for the EnviroAtlas community. This dataset was produced by the US EPA to support research and online...

  9. Socio-Demographic Correlates of Overweight and Obesity among ...

    African Journals Online (AJOL)

    AJRH Managing Editor

    demographic factors with increased BMI among Nigeria women aged 20-49 years using secondary data collected for the .... Half (50.2%) of the women were of the Islamic .... South East .... demonstrates evidence of good living, makes them.

  10. 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.

  11. Electrofluidic systems for contrast management

    Science.gov (United States)

    Rebello, Keith J.; Maranchi, Jeffrey P.; Tiffany, Jason E.; Brown, Christopher Y.; Maisano, Adam J.; Hagedon, Matthew A.; Heikenfeld, Jason C.

    2012-06-01

    Operating in dynamic lighting conditions and in greatly varying backgrounds is challenging. Current paints and state-ofthe- art passive adaptive coatings (e.g. photochromics) are not suitable for multi- environment situations. A semi-active, low power, skin is needed that can adapt its reflective properties based on the background environment to minimize contrast through the development and incorporation of suitable pigment materials. Electrofluidic skins are a reflective display technology for electronic ink and paper applications. The technology is similar to that in E Ink but makes use of MEMS based microfluidic structures, instead of simple black and white ink microcapsules dispersed in clear oil. Electrofluidic skin's low power operation and fast switching speeds (~20 ms) are an improvement over current state-ofthe- art contrast management technologies. We report on a microfluidic display which utilizes diffuse pigment dispersion inks to change the contrast of the underlying substrate from 5.8% to 100%. Voltage is applied and an electromechanical pressure is used to pull a pigment dispersion based ink from a hydrophobic coated reservoir into a hydrophobic coated surface channel. When no voltage is applied, the Young-Laplace pressure pushes the pigment dispersion ink back down into the reservoir. This allows the pixel to switch from the on and off state by balancing the two pressures. Taking a systems engineering approach from the beginning of development has enabled the technology to be integrated into larger systems.

  12. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... Education What's New Emergency Preparedness and You 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 ...

  13. "Hillary - en god historie"

    DEFF Research Database (Denmark)

    Bjerre, Thomas Ærvold

    2007-01-01

    Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november......Anmeldelse af Carl Bernsteins Hillary Rodham Clinton og Michael Ehrenreichs Hillary - En amerikansk historie Udgivelsesdato: 15. november...

  14. History of Bioterrorism: Botulism

    Science.gov (United States)

    ... Guide Reaching At-Risk Populations MedCon 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 ...

  15. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... What's New Emergency Preparedness and You 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 ...

  16. History of Bioterrorism: Botulism

    Medline Plus

    Full Text Available ... Education What's New Emergency Preparedness and You 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 ...

  17. [Integration of demographic variables into development plans in the Sahel].

    Science.gov (United States)

    Wane, H R

    1992-07-01

    A founding principle of the Program of Action of N'Djamena is the interdependence of population and development and the need for development strategies to take demographic factors into account. The concept of integration of population variables into development has evolved since its introduction in the 1974 World Population Plan of Action from a simple description of population size, growth rates, and distribution to a stress on harmonizing population policies and development policies with macroeconomic variables. The essence of the concept is the consideration given by development policies and programs to the interrelations between population, resources, the environment, and development factors. Population variables and goals should ideally be treated as endogenous variables in development planning, but in practice the extreme complexity of such a systematic approach limits its ability to be made operational. Usually the most crucial problems only are included. Integrated planning is composed of explicit or implicit population policies intended to influence demographic variables and of socioeconomic policies intended to adapt to demographic change. In the Sahel, only Senegal, Burkina Faso, and Mali have formal population policies, but around 1980 several countries of the region began to show interest in influencing demographic variables as they did economic variables. Fundamental principles for developing an integration strategy can be applied regardless or whether the plan is based on projections, analysis of interaction of a demographic variable with factors specific to a sector, or a monosectorial or multisectorial demoeconomic planning model. Demographic data is used more frequently in diagnosing problems than in developing projections or formulating objectives. The level of disaggregation of demographic projections and estimates tends to be low, despite the great potential utility of demographic projections in planning. Demographic projections can be useful

  18. Demographic Dynamics and the Empirics of Economic Growth

    OpenAIRE

    Michael Sarel

    1995-01-01

    This paper examines the effects of demographic dynamics on the measured rates of economic growth. First, it develops a model of production with labor productivity that varies with age. Second, it uses macroeconomic and demographic data to estimate the relative productivity of different age groups. Third, it constructs a panel database of effective labor supply in order to reflect the changing age-structure of the population. Fourth, it decomposes the historical measured growth rates into effe...

  19. Pension Reform and Demographic Uncertainty : The Case of Germany

    OpenAIRE

    2003-01-01

    The present paper compares the distributional and risk-sharing consequences of two pension reform proposals in Germany which both aim to improve the sustainability of the current system by introducing demographic variables to the benefit calculation. While the first reform proposes a so-called "sustainability factor" which measures the changes in the dependency ratio, the second reform proposes a so-called "demographic factor" which takes into account the changes in life expectancy. Our simul...

  20. Fast demographic traits promote high diversification rates of Amazonian trees

    OpenAIRE

    Baker, Timothy R.; Pennington, R. Toby; Magallon, Susana; Gloor, Emanuel; Laurance, William F.; Alexiades, Miguel; Alvarez, Esteban; Araujo, Alejandro; Arets, Eric J. M. M.; Aymard, Gerardo; de Oliveira, Atila Alves; Amaral, Iêda; Arroyo, Luzmila; Bonal, Damien; Roel J.W. Brienen

    2014-01-01

    The Amazon rain forest sustains the world's highest tree diversity, but it remains unclear why some clades of trees are hyperdiverse, whereas others are not. Using dated phylogenies, estimates of current species richness and trait and demographic data from a large network of forest plots, we show that fast demographic traits - short turnover times - are associated with high diversification rates across 51 clades of canopy trees. This relationship is robust to assuming that diversification rat...