Science.gov

Sample records for joint demographic history

  1. Geographical barriers and climate influence demographic history in narrowleaf cottonwoods

    PubMed Central

    Evans, L M; Allan, G J; DiFazio, S P; Slavov, G T; Wilder, J A; Floate, K D; Rood, S B; Whitham, T G

    2015-01-01

    Studies of genetic variation can clarify the role of geography and spatio-temporal variation of climate in shaping demography, particularly in temperate zone tree species with large latitudinal ranges. Here, we examined genetic variation in narrowleaf cottonwood, Populus angustifolia, a dominant riparian tree. Using multi-locus surveys of polymorphism in 363 individuals across the species' 1800 km latitudinal range, we found that, first, P. angustifolia has stronger neutral genetic structure than many forest trees (simple sequence repeat (SSR) FST=0.21), with major genetic groups corresponding to large apparent geographical barriers to gene flow. Second, using SSRs and putatively neutral sequenced loci, coalescent simulations indicated that populations diverged before the last glacial maximum (LGM), suggesting the presence of population structure before the LGM. Third, the LGM and subsequent warming appear to have had different influences on each of these distinct populations, with effective population size reduction in the southern extent of the range but major expansion in the north. These results are consistent with the hypothesis that climate and geographic barriers have jointly affected the demographic history of P. angustifolia, and point the importance of both factors as being instrumental in shaping genetic variation and structure in widespread forest trees. PMID:25585921

  2. Linkage Disequilibrium and Demographic History of Wild and Domestic Canids

    PubMed Central

    Gray, Melissa M.; Granka, Julie M.; Bustamante, Carlos D.; Sutter, Nathan B.; Boyko, Adam R.; Zhu, Lan; Ostrander, Elaine A.; Wayne, Robert K.

    2009-01-01

    Assessing the extent of linkage disequilibrium (LD) in natural populations of a nonmodel species has been difficult due to the lack of available genomic markers. However, with advances in genotyping and genome sequencing, genomic characterization of natural populations has become feasible. Using sequence data and SNP genotypes, we measured LD and modeled the demographic history of wild canid populations and domestic dog breeds. In 11 gray wolf populations and one coyote population, we find that the extent of LD as measured by the distance at which r2 = 0.2 extends <10 kb in outbred populations to >1.7 Mb in populations that have experienced significant founder events and bottlenecks. This large range in the extent of LD parallels that observed in 18 dog breeds where the r2 value varies from ∼20 kb to >5 Mb. Furthermore, in modeling demographic history under a composite-likelihood framework, we find that two of five wild canid populations exhibit evidence of a historical population contraction. Five domestic dog breeds display evidence for a minor population contraction during domestication and a more severe contraction during breed formation. Only a 5% reduction in nucleotide diversity was observed as a result of domestication, whereas the loss of nucleotide diversity with breed formation averaged 35%. PMID:19189949

  3. Contrasting demographic histories of the neighboring bonobo and chimpanzee.

    PubMed

    Hvilsom, Christina; Carlsen, Frands; Heller, Rasmus; Jaffré, Nina; Siegismund, Hans R

    2014-01-01

    The Pleistocene epoch was a period of dramatic climate change that had profound impacts on the population sizes of many animal species. How these species were shaped by past events is often unclear, hindering our understanding of the population dynamics resulting in present day populations. We 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 of the neighboring bonobo remained constant. The changes in population size are likely linked to changes in habitat area due to climate oscillations during the late Pleistocene. Furthermore, the timing of population expansion for the rainforest-adapted chimpanzee is concurrent with the expansion of the savanna-adapted human, which could suggest a common response to changed climate conditions around 50,000-80,000 years ago.

  4. Demographic history and linkage disequilibrium in human populations.

    PubMed

    Laan, M; Pääbo, S

    1997-12-01

    In the human genome, linkage disequilibrium (LD)--the non-random association of alleles at chromosomal loci--has been studied mainly in regions surrounding disease genes on affected chromosomes. Consequently, little information is available on the distribution of LD across anonymous genomic regions in the general population. However, demographic history is expected to influence the extent of overall LD across the genome, so a population that has been of constant size will display higher levels of LD than a population that has expanded. In support of this, the extent of LD between anonymous loci on chromosome 4 in chimpanzees (as a model of a population of constant size) has been compared to that in Finns (as a model of an expanded population; refs 8,9) and found to exhibit more LD than in the latter population. In Europe, studies of mitochondrial (mt) DNA sequences have suggested that most populations have experienced expansion, whereas the Saami in northern Fenno-Scandinavia have been of constant size (Table 1). Thus, in northern Europe, populations with radically different demographic histories live in close geographic proximity to each other. We studied the allelic associations between anonymous microsatellite loci on the X chromosome in the Saami and neighbouring populations and found dramatically higher levels of LD in the Saami than in other populations in the region. This indicates that whereas recently expanded populations, such as the Finns, are well suited to map single disease genes affected by recent mutations, populations that have been of constant size, such as the Saami, may be much better suited to map genes for complex traits that are caused by older mutations.

  5. Phylogeography and demographic history of the neotropical otter (Lontra longicaudis).

    PubMed

    Trinca, Cristine S; de Thoisy, Benoit; Rosas, Fernando C W; Waldemarin, Helen F; Koepfli, Klaus-Peter; Vianna, Juliana A; Eizirik, Eduardo

    2012-07-01

    The Neotropical otter (Lontra longicaudis) is a medium-sized semiaquatic carnivore with a broad distribution in the Neotropical region. Despite being apparently common in many areas, it is one of the least known otters, and genetic studies on this species are scarce. Here, we have investigated its genetic diversity, population structure, and demographic history across a large portion of its geographic range by analyzing 1471 base pairs (bp) of mitochondrial DNA from 52 individuals. Our results indicate that L. longicaudis presents high levels of genetic diversity and a consistent phylogeographic pattern, suggesting the existence of at least 4 distinct evolutionary lineages in South America. The observed phylogeographic partitions are partially congruent with the subspecies classification previously proposed for this species. Coalescence-based analyses indicate that Neotropical otter mitochondrial DNA lineages have shared a rather recent common ancestor, approximately 0.5 Ma, and have subsequently diversified into the observed phylogroups. A consistent scenario of recent population expansion was identified in Eastern South America based on several complementary analyses of historical demography. The results obtained here provide novel insights on the evolutionary history of this largely unknown Neotropical mustelid and should be useful to design conservation and management policies on behalf of this species and its habitats.

  6. Demographic history and rare allele sharing among human populations.

    PubMed

    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

    2011-07-19

    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.

  7. Demographic history and rare allele sharing among human populations

    PubMed Central

    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

  8. Inferring Demographic History from a Spectrum of Shared Haplotype Lengths

    PubMed Central

    Harris, Kelley; Nielsen, Rasmus

    2013-01-01

    There has been much recent excitement about the use of genetics to elucidate ancestral history and demography. Whole genome data from humans and other species are revealing complex stories of divergence and admixture that were left undiscovered by previous smaller data sets. A central challenge is to estimate the timing of past admixture and divergence events, for example the time at which Neanderthals exchanged genetic material with humans and the time at which modern humans left Africa. Here, we present a method for using sequence data to jointly estimate the timing and magnitude of past admixture events, along with population divergence times and changes in effective population size. We infer demography from a collection of pairwise sequence alignments by summarizing their length distribution of tracts of identity by state (IBS) and maximizing an analytic composite likelihood derived from a Markovian coalescent approximation. Recent gene flow between populations leaves behind long tracts of identity by descent (IBD), and these tracts give our method power by influencing the distribution of shared IBS tracts. In simulated data, we accurately infer the timing and strength of admixture events, population size changes, and divergence times over a variety of ancient and recent time scales. Using the same technique, we analyze deeply sequenced trio parents from the 1000 Genomes project. The data show evidence of extensive gene flow between Africa and Europe after the time of divergence as well as substructure and gene flow among ancestral hominids. In particular, we infer that recent African-European gene flow and ancient ghost admixture into Europe are both necessary to explain the spectrum of IBS sharing in the trios, rejecting simpler models that contain less population structure. PMID:23754952

  9. Demographic screening for MRSA may compromise the effectiveness of ring fencing on a joint replacement unit.

    PubMed

    Schmidt, H-M A; Izon, C; Maley, M W

    2012-11-01

    Ring fencing of joint replacement (JR) units has been reported to reduce infections and is recommended by health authorities in Australia and the UK. It has not been determined whether a demographic risk assessment is adequate to prevent the admission of patients colonized with meticillin-resistant Staphylococcus aureus (MRSA) to ring-fenced units. As such, 250 admissions to the JR unit of a suburban Sydney hospital were screened, and MRSA colonization was identified in 2.8% of patients complying with the demographic risk assessment. Demographic risk assessment is not an adequate substitute for physical MRSA screening, and undermines the effectiveness of ring-fencing procedures.

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

    PubMed

    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.

  11. Formal linguistics as a cue to demographic history.

    PubMed

    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.

  12. The Joint Cruise Missiles Project: An Acquisition History--Appendixes

    DTIC Science & Technology

    1982-08-01

    itilan History," Rand R-3039, Auqust 198 *_2These appendixes include: Joint Cruise Missiles Project Office Evolution ; DMA/JCMPO Interaction3 Cruise...APPENDIX A: JOINT CRUISE MISSILES PROJECT OFFICE EVOLUTION ................1 Creation of the JCMPO........................................1U:ALCM...Management Transition..................................11 JCMPO Management Evolution After ALCM Transfer...............15 B: DMA/JCMPO INTERACTION

  13. Joint Genome Institute's Automation Approach and History

    SciTech Connect

    Roberts, Simon

    2006-07-05

    Department of Energy/Joint Genome Institute (DOE/JGI) collaborates with DOE national laboratories and community users, to advance genome science in support of the DOE missions of clean bio-energy, carbon cycling, and bioremediation.

  14. Length distributions of identity by descent reveal fine-scale demographic history.

    PubMed

    Palamara, Pier Francesco; Lencz, Todd; Darvasi, Ariel; Pe'er, Itsik

    2012-11-02

    Data-driven studies of identity by descent (IBD) were recently enabled by high-resolution genomic data from large cohorts and scalable algorithms for IBD detection. Yet, haplotype sharing currently represents an underutilized source of information for population-genetics research. We present analytical results on the relationship between haplotype sharing across purportedly unrelated individuals and a population's demographic history. We express the distribution of IBD sharing across pairs of individuals for segments of arbitrary length as a function of the population's demography, and we derive an inference procedure to reconstruct such demographic history. The accuracy of the proposed reconstruction methodology was extensively tested on simulated data. We applied this methodology to two densely typed data sets: 500 Ashkenazi Jewish (AJ) individuals and 56 Kenyan Maasai (MKK) individuals (HapMap 3 data set). Reconstructing the demographic history of the AJ cohort, we recovered two subsequent population expansions, separated by a severe founder event, consistent with previous analysis of lower-throughput genetic data and historical accounts of AJ history. In the MKK cohort, high levels of cryptic relatedness were detected. The spectrum of IBD sharing is consistent with a demographic model in which several small-sized demes intermix through high migration rates and result in enrichment of shared long-range haplotypes. This scenario of historically structured demographies might explain the unexpected abundance of runs of homozygosity within several populations.

  15. Demographic Histories, Isolation and Social Factors as Determinants of the Genetic Structure of Alpine Linguistic Groups

    PubMed Central

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

    2013-01-01

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

  16. How the World Survived the Population Bomb: Lessons From 50 Years of Extraordinary Demographic History

    PubMed Central

    Lam, David

    2012-01-01

    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. PMID:22005884

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

    PubMed

    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.

  18. Genomic sequencing of Plasmodium falciparum malaria parasites from Senegal reveals the demographic history of the population.

    PubMed

    Chang, Hsiao-Han; Park, Daniel J; Galinsky, Kevin J; Schaffner, Stephen F; Ndiaye, Daouda; Ndir, Omar; Mboup, Souleymane; Wiegand, Roger C; Volkman, Sarah K; Sabeti, Pardis C; Wirth, Dyann F; Neafsey, Daniel E; Hartl, Daniel L

    2012-11-01

    Malaria is a deadly disease that causes nearly one million deaths each year. To develop methods to control and eradicate malaria, it is important to understand the genetic basis of Plasmodium falciparum adaptations to antimalarial treatments and the human immune system while taking into account its demographic history. To study the demographic history and identify genes under selection more efficiently, we sequenced the complete genomes of 25 culture-adapted P. falciparum isolates from three sites in Senegal. We show that there is no significant population structure among these Senegal sampling sites. By fitting demographic models to the synonymous allele-frequency spectrum, we also estimated a major 60-fold population expansion of this parasite population ∼20,000-40,000 years ago. Using inferred demographic history as a null model for coalescent simulation, we identified candidate genes under selection, including genes identified before, such as pfcrt and PfAMA1, as well as new candidate genes. Interestingly, we also found selection against G/C to A/T changes that offsets the large mutational bias toward A/T, and two unusual patterns: similar synonymous and nonsynonymous allele-frequency spectra, and 18% of genes having a nonsynonymous-to-synonymous polymorphism ratio >1.

  19. Unification Theory of Optimal Life Histories and Linear Demographic Models in Internal Stochasticity

    PubMed Central

    Oizumi, Ryo

    2014-01-01

    Life history of organisms is exposed to uncertainty generated by internal and external stochasticities. Internal stochasticity is generated by the randomness in each individual life history, such as randomness in food intake, genetic character and size growth rate, whereas external stochasticity is due to the environment. For instance, it is known that the external stochasticity tends to affect population growth rate negatively. It has been shown in a recent theoretical study using path-integral formulation in structured linear demographic models that internal stochasticity can affect population growth rate positively or negatively. However, internal stochasticity has not been the main subject of researches. Taking account of effect of internal stochasticity on the population growth rate, the fittest organism has the optimal control of life history affected by the stochasticity in the habitat. The study of this control is known as the optimal life schedule problems. In order to analyze the optimal control under internal stochasticity, we need to make use of “Stochastic Control Theory” in the optimal life schedule problem. There is, however, no such kind of theory unifying optimal life history and internal stochasticity. This study focuses on an extension of optimal life schedule problems to unify control theory of internal stochasticity into linear demographic models. First, we show the relationship between the general age-states linear demographic models and the stochastic control theory via several mathematical formulations, such as path–integral, integral equation, and transition matrix. Secondly, we apply our theory to a two-resource utilization model for two different breeding systems: semelparity and iteroparity. Finally, we show that the diversity of resources is important for species in a case. Our study shows that this unification theory can address risk hedges of life history in general age-states linear demographic models. PMID:24945258

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

    PubMed Central

    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

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

    PubMed

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

    2017-01-16

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Reconstructing the demographic history of orang-utans using Approximate Bayesian Computation.

    PubMed

    Nater, Alexander; Greminger, Maja P; Arora, Natasha; van Schaik, Carel P; Goossens, Benoit; Singleton, Ian; Verschoor, Ernst J; Warren, Kristin S; Krützen, Michael

    2015-01-01

    Investigating how different evolutionary forces have shaped patterns of DNA variation within and among species requires detailed knowledge of their demographic history. Orang-utans, whose distribution is currently restricted to the South-East Asian islands of Borneo (Pongo pygmaeus) and Sumatra (Pongo abelii), have likely experienced a complex demographic history, influenced by recurrent changes in climate and sea levels, volcanic activities and anthropogenic pressures. Using the most extensive sample set of wild orang-utans to date, we employed an Approximate Bayesian Computation (ABC) approach to test the fit of 12 different demographic scenarios to the observed patterns of variation in autosomal, X-chromosomal, mitochondrial and Y-chromosomal markers. In the best-fitting model, Sumatran orang-utans exhibit a deep split of populations north and south of Lake Toba, probably caused by multiple eruptions of the Toba volcano. In addition, we found signals for a strong decline in all Sumatran populations ~24 ka, probably associated with hunting by human colonizers. In contrast, Bornean orang-utans experienced a severe bottleneck ~135 ka, followed by a population expansion and substructuring starting ~82 ka, which we link to an expansion from a glacial refugium. We showed that orang-utans went through drastic changes in population size and connectedness, caused by recurrent contraction and expansion of rainforest habitat during Pleistocene glaciations and probably hunting by early humans. Our findings emphasize the fact that important aspects of the evolutionary past of species with complex demographic histories might remain obscured when applying overly simplified models.

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

    PubMed

    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.

  5. Genetic diversification and demographic history of the cactophilic pseudoscorpion Dinocheirus arizonensis from the Sonoran Desert.

    PubMed

    Pfeiler, Edward; Bitler, Ben G; Castrezana, Sergio; Matzkin, Luciano M; Markow, Therese A

    2009-07-01

    Sequence data from a segment of the mitochondrial cytochrome c oxidase subunit I (COI) gene were used to examine phylogenetic relationships, estimate gene flow and infer demographic history of the cactophilic chernetid pseudoscorpion, Dinocheirus arizonensis (Banks), from the Sonoran Desert. Phylogenetic trees resolved two clades of D. arizonensis, one from mainland Sonora, Mexico and southern Arizona (clade I) and the other from the Baja California peninsula and southern Arizona (clade II). The two clades were separated by a mean genetic distance (d) of approximately 2.6%. Hierarchical analysis of molecular variance indicated highly significant population structuring in D. arizonensis (overall Phi(ST)=0.860; P<0.0001), with 80% of the genetic variation distributed among the two clades. Most pairwise comparisons of Phi(ST) among populations within each clade, however, were not significant. The results suggest that phoretic dispersal on vagile cactophilic insects such as the neriid cactus fly Odontoloxozus longicornis (Coquillett) provides sufficient gene flow to offset the accumulation of unique haplotypes within each clade of the non-vagile pseudoscorpion. Preliminary results on dispersal capability of O. longicornis were consistent with this conclusion. Tests designed to reconstruct demographic history from sequence data indicated that both clades of D. arizonensis, as well as O. longicornis, have experienced historical population expansions. Potential barriers to gene flow that may have led to genetic isolation and diversification in clades I and II of D. arizonensis are discussed.

  6. Estimating genome-wide heterozygosity: effects of demographic history and marker type

    PubMed Central

    Miller, J M; Malenfant, R M; David, P; Davis, C S; Poissant, J; Hogg, J T; Festa-Bianchet, M; Coltman, D W

    2014-01-01

    Heterozygosity–fitness correlations (HFCs) are often used to link individual genetic variation to differences in fitness. However, most studies examining HFCs find weak or no correlations. Here, we derive broad theoretical predictions about how many loci are needed to adequately measure genomic heterozygosity assuming different levels of identity disequilibrium (ID), a proxy for inbreeding. We then evaluate the expected ability to detect HFCs using an empirical data set of 200 microsatellites and 412 single nucleotide polymorphisms (SNPs) genotyped in two populations of bighorn sheep (Ovis canadensis), with different demographic histories. In both populations, heterozygosity was significantly correlated across marker types, although the strength of the correlation was weaker in a native population compared with one founded via translocation and later supplemented with additional individuals. Despite being bi-allelic, SNPs had similar correlations to genome-wide heterozygosity as microsatellites in both populations. For both marker types, this association became stronger and less variable as more markers were considered. Both populations had significant levels of ID; however, estimates were an order of magnitude lower in the native population. As with heterozygosity, SNPs performed similarly to microsatellites, and precision and accuracy of the estimates of ID increased as more loci were considered. Although dependent on the demographic history of the population considered, these results illustrate that genome-wide heterozygosity, and therefore HFCs, are best measured by a large number of markers, a feat now more realistically accomplished with SNPs than microsatellites. PMID:24149650

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

    PubMed Central

    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

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

    PubMed

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

    2017-02-25

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

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

    PubMed

    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.

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

    PubMed Central

    Roux, Camille; Neuenschwander, Samuel; Goudet, Jérôme; Launey, Sophie; Evanno, Guillaume

    2016-01-01

    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. PMID:27077007

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

    PubMed

    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

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

    PubMed Central

    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

  13. Demographic history and the low genetic diversity in Dipteryx alata (Fabaceae) from Brazilian Neotropical savannas

    PubMed Central

    Collevatti, R G; Telles, M P C; Nabout, J C; Chaves, L J; Soares, T N

    2013-01-01

    Genetic effects of habitat fragmentation may be undetectable because they are generally a recent event in evolutionary time or because of confounding effects such as historical bottlenecks and historical changes in species' distribution. To assess the effects of demographic history on the genetic diversity and population structure in the Neotropical tree Dipteryx alata (Fabaceae), we used coalescence analyses coupled with ecological niche modeling to hindcast its distribution over the last 21 000 years. Twenty-five populations (644 individuals) were sampled and all individuals were genotyped using eight microsatellite loci. All populations presented low allelic richness and genetic diversity. The estimated effective population size was small in all populations and gene flow was negligible among most. We also found a significant signal of demographic reduction in most cases. Genetic differentiation among populations was significantly correlated with geographical distance. Allelic richness showed a spatial cline pattern in relation to the species' paleodistribution 21 kyr BP (thousand years before present), as expected under a range expansion model. Our results show strong evidences that genetic diversity in D. alata is the outcome of the historical changes in species distribution during the late Pleistocene. Because of this historically low effective population size and the low genetic diversity, recent fragmentation of the Cerrado biome may increase population differentiation, causing population decline and compromising long-term persistence. PMID:23591520

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

    PubMed

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

    2013-01-01

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

  15. Life history and demographic variation in the lizard Sceloporus graciosus: A long-term study

    SciTech Connect

    Tinkle, D.W. ); Dunham, A.E. ); Congdon, J.D. )

    1993-12-01

    An 11-yr study of life history and demographic variation in the sagebrush lizard Sceloporus graciosus was carried out on two study areas (Rattlesnake Ridge and Ponderosa Flat) in the Kolob Mesa Section of Zion National Park, Utah. Two primary objectives of this mark-recapture study were to: (1) quantify variation in age structure, age, and size at maturity, age-specific survivorship and fecundity, and individual growth rates, and (2) conduct a series of density reduction experiments designed to elucidate the effects of density on growth rates and survival of posthatchling lizards. In addition, the authors examined the relationships of variation in population density and deviation from long-term average precipitation and temperature to variation in individual growth, reproduction, and demography. 43 refs., 5 figs., 11 tabs.

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

    USGS Publications Warehouse

    LaManna, Joseph A.; Martin, Thomas E.

    2016-01-01

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

  17. Neutral nuclear variation in Baboons (genus Papio) provides insights into their evolutionary and demographic histories.

    PubMed

    Boissinot, Stéphane; Alvarez, Lauren; Giraldo-Ramirez, Juliana; Tollis, Marc

    2014-12-01

    Baboons (genus Papio) are distributed over most of sub-Saharan Africa and in the southern portion of the Arabian Peninsula. Six distinct morphotypes, with clearly defined geographic distributions, are recognized (the olive, chacma, yellow, Guinea, Kinda, and hamadryas baboons). The evolutionary relationships among baboon forms have long been a controversial issue. Phylogenetic analyses based on mitochondrial DNA sequences revealed that the modern baboon morphotypes are mitochondrially paraphyletic or polyphyletic. The discordance between mitochondrial lineages and morphology is indicative of extensive introgressive hybridization between ancestral baboon populations. To gain insights into the evolutionary relationships among morphotypes and their demographic history, we performed an analysis of nuclear variation in baboons. We sequenced 13 noncoding, putatively neutral, nuclear regions, and scored the presence/absence of 18 polymorphic transposable elements in a sample of 45 baboons belonging to five of the six recognized baboon forms. We found that the chacma baboon is the sister-taxon to all other baboons and the yellow baboon is the sister-taxon to an unresolved northern clade containing the olive, Guinea, and hamadryas baboons. We estimated that the diversification of baboons occurred entirely in the Pleistocene, the earliest split dating ∼1.5 million years ago, and that baboons have experienced relatively large and constant effective population sizes for most of their evolutionary history (∼30,000 to 95,000 individuals).

  18. Neutral Nuclear Variation in Baboons (genus Papio) Provides Insights into their Evolutionary and Demographic Histories

    PubMed Central

    Boissinot, Stéphane; Alvarez, Lauren; Giraldo-Ramirez, Juliana; Tollis, Marc

    2015-01-01

    Baboons (genus Papio) are distributed over most of sub-Saharan Africa and in the southern portion of the Arabian Peninsula. Six distinct morphotypes, with clearly defined geographic distributions, are recognized (the olive, chacma, yellow, Guinea, Kinda and hamadryas baboons). The evolutionary relationships among baboon forms have long been a controversial issue. Phylogenetic analyses based on mitochondrial DNA sequences revealed that the modern baboon morphotypes are mitochondrially paraphyletic or polyphyletic. The discordance between mitochondrial lineages and morphology is indicative of extensive introgressive hybridization between ancestral baboon populations. To gain insights into the evolutionary relationships among morphotypes and their demographic history, we performed an analysis of nuclear variation in baboons. We sequenced 13 non-coding, putatively neutral, nuclear regions and scored the presence/absence of 18 polymorphic transposable elements in a sample of 45 baboons belonging to five of the six recognized baboon forms. We found that the chacma baboon is the sister-taxon to all other baboons and the yellow baboon is the sister-taxon to an unresolved northern clade containing the olive, Guinea and hamadryas baboons. We estimated that the diversification of baboons occurred entirely in the Pleistocene, the earliest split dating ~1.5 million years ago, and that baboons have experienced relatively large and constant population sizes for most of their evolutionary history (~30,000 to 95,000 individuals). PMID:25234435

  19. Comparative Genetic Structure and Demographic History in Endemic Galápagos Weevils

    PubMed Central

    Stepien, Courtney C.; Sijapati, Manisha; Roque Albelo, Lázaro

    2012-01-01

    The challenge of maintaining genetic diversity within populations can be exacerbated for island endemics if they display population dynamics and behavioral attributes that expose them to genetic drift without the benefits of gene flow. We assess patterns of the genetic structure and demographic history in 27 populations of 9 species of flightless endemic Galápagos weevils from 9 of the islands and 1 winged introduced close relative. Analysis of mitochondrial DNA reveals a significant population structure and moderately variable, though demographically stable, populations for lowland endemics (FST = 0.094–0.541; π: 0.014–0.042; Mismatch P = 0.003–0.026; and D(Tajima) = −0.601 to 1.203), in contrast to signals of past contractions and expansions in highland specialists on 2 islands (Mismatch P = 0.003–0.026 and D(Tajima) = −0.601 to 1.203). We interpret this series of variable and highly structured population groups as a system of long-established, independently founded island units, where structuring could be a signal of microallopatric differentiation due to patchy host plant distribution and poor dispersal abilities. We suggest that the severe reduction and subsequent increase of a suitably moist habitat that accompanied past climatic variation could have contributed to the observed population fluctuations in highland specialists. We propose the future exploration of hybridization between the introduced and highland endemic species on Santa Cruz, especially given the expansion of the introduced species into the highlands, the sensitivity to past climatic variation detected in highland populations, and the potentially threatened state of single-island endemics. PMID:22174444

  20. Population Genetic Structure and Demographic History of Atrina pectinata Based on Mitochondrial DNA and Microsatellite Markers

    PubMed Central

    Xue, Dong-Xiu; Wang, Hai-Yan; Zhang, Tao; Liu, Jin-Xian

    2014-01-01

    The pen shell, Atrina pectinata, is one of the commercial bivalves in East Asia and thought to be recently affected by anthropogenic pressure (habitat destruction and/or fishing pressure). Information on its population genetic structure is crucial for the conservation of A. pectinata. Considering its long pelagic larval duration and iteroparity with high fecundity, the genetic structure for A. pectinata could be expected to be weak at a fine scale. However, the unusual oceanography in the coasts of China and Korea suggests potential for restricted dispersal of pelagic larvae and geographical differentiation. In addition, environmental changes associated with Pleistocene sea level fluctuations on the East China Sea continental shelf may also have strongly influenced historical population demography and genetic diversity of marine organisms. Here, partial sequences of the mitochondrial Cytochrome c oxidase subunit I (COI) gene and seven microsatellite loci were used to estimate population genetic structure and demographic history of seven samples from Northern China coast and one sample from North Korea coast. Despite high levels of genetic diversity within samples, there was no genetic differentiation among samples from Northern China coast and low but significant genetic differentiation between some of the Chinese samples and the North Korean sample. A late Pleistocene population expansion, probably after the Last Glacial Maximum, was also demonstrated for A. pectinata samples. No recent genetic bottleneck was detected in any of the eight samples. We concluded that both historical recolonization (through population range expansion and demographic expansion in the late Pleistocene) and current gene flow (through larval dispersal) were responsible for the weak level of genetic structure detected in A. pectinata. PMID:24789175

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

    PubMed

    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.

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

    PubMed Central

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

    2014-01-01

    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. PMID:25535558

  3. Shipwrecks and founder effects: divergent demographic histories reflected in Caribbean mtDNA.

    PubMed

    Salas, Antonio; Richards, Martin; Lareu, María-Victoria; Sobrino, Beatriz; Silva, Sandra; Matamoros, Mireya; Macaulay, Vincent; Carracedo, Angel

    2005-12-01

    During the period of the Atlantic slave trade (15th-19th centuries), millions of people were forced to move from Africa to many American destinations, changing dramatically the human landscape of the Americas. Here, we analyze mitochondrial DNA from two different American populations with African ancestry, with hitherto unknown European and Native American components. On the basis of historical records, African-Americans from Chocó (Colombia) and the Garífunas (or "Black Carib") of Honduras are likely to have had very different demographic histories, with a significant founder effect in the formation of the latter. Both the common features and differences are reflected in their mtDNA composition. Both show a minor component (approximately 16%) from Native Central/South Americans and a larger component (approximately 84%) from sub-Saharan Africans. The latter component is very diverse in the African-Americans from Chocó, similar to that of sub-Saharan Africans, but much less so in the Garífunas, with several mtDNA types elevated to high frequency, suggesting the action of genetic drift.

  4. Demographic History of a Recent Invasion of House Mice on the Isolated Island of Gough

    PubMed Central

    Gray, Melissa M.; Wegmann, Daniel; Haasl, Ryan J.; White, Michael A.; Gabriel, Sofia I.; Searle, Jeremy B.; Cuthbert, Richard J.; Ryan, Peter G.; Payseur, Bret A.

    2014-01-01

    Island populations provide natural laboratories for studying key contributors to evolutionary change, including natural selection, population size, and the colonization of new environments. The demographic histories of island populations can be reconstructed from patterns of genetic diversity. House mice (Mus musculus) inhabit islands throughout the globe, making them an attractive system for studying island colonization from a genetic perspective. Gough Island, in the central South Atlantic Ocean, is one of the remotest islands in the world. House mice were introduced to Gough Island by sealers during the 19th century, and display unusual phenotypes, including exceptionally large body size and carnivorous feeding behavior. We describe genetic variation in Gough Island mice using mitochondrial sequences, nuclear sequences, and microsatellites. Phylogenetic analysis of mitochondrial sequences suggested that Gough Island mice belong to Mus musculus domesticus, with the maternal lineage possibly originating in England or France. Cluster analyses of microsatellites revealed genetic membership for Gough Island mice in multiple coastal populations in Western Europe, suggesting admixed ancestry. Gough Island mice showed substantial reductions in mitochondrial and nuclear sequence variation and weak reductions in microsatellite diversity compared with Western European populations, consistent with a population bottleneck. Approximate Bayesian Computation (ABC) estimated that mice recently colonized Gough Island (~100 years ago) and experienced a 98% reduction in population size followed by a rapid expansion. Our results indicate that the unusual phenotypes of Gough Island mice evolved rapidly, positioning these mice as useful models for understanding rapid phenotypic evolution. PMID:24617968

  5. Deciphering the Wisent Demographic and Adaptive Histories from Individual Whole-Genome Sequences

    PubMed Central

    Gautier, Mathieu; Moazami-Goudarzi, Katayoun; Levéziel, Hubert; Parinello, Hugues; Grohs, Cécile; Rialle, Stéphanie; Kowalczyk, Rafał; Flori, Laurence

    2016-01-01

    As the largest European herbivore, the wisent (Bison bonasus) is emblematic of the continent wildlife but has unclear origins. Here, we infer its demographic and adaptive histories from two individual whole-genome sequences via a detailed comparative analysis with bovine genomes. We estimate that the wisent and bovine species diverged from 1.7 × 106 to 850,000 years before present (YBP) through a speciation process involving an extended period of limited gene flow. Our data further support the occurrence of more recent secondary contacts, posterior to the Bos taurus and Bos indicus divergence (∼150,000 YBP), between the wisent and (European) taurine cattle lineages. Although the wisent and bovine population sizes experienced a similar sharp decline since the Last Glacial Maximum, we find that the wisent demography remained more fluctuating during the Pleistocene. This is in agreement with a scenario in which wisents responded to successive glaciations by habitat fragmentation rather than southward and eastward migration as for the bovine ancestors. We finally detect 423 genes under positive selection between the wisent and bovine lineages, which shed a new light on the genome response to different living conditions (temperature, available food resource, and pathogen exposure) and on the key gene functions altered by the domestication process. PMID:27436010

  6. Demographic history of a recent invasion of house mice on the isolated Island of Gough.

    PubMed

    Gray, Melissa M; Wegmann, Daniel; Haasl, Ryan J; White, Michael A; Gabriel, Sofia I; Searle, Jeremy B; Cuthbert, Richard J; Ryan, Peter G; Payseur, Bret A

    2014-04-01

    Island populations provide natural laboratories for studying key contributors to evolutionary change, including natural selection, population size and the colonization of new environments. The demographic histories of island populations can be reconstructed from patterns of genetic diversity. House mice (Mus musculus) inhabit islands throughout the globe, making them an attractive system for studying island colonization from a genetic perspective. Gough Island, in the central South Atlantic Ocean, is one of the remotest islands in the world. House mice were introduced to Gough Island by sealers during the 19th century and display unusual phenotypes, including exceptionally large body size and carnivorous feeding behaviour. We describe genetic variation in Gough Island mice using mitochondrial sequences, nuclear sequences and microsatellites. Phylogenetic analysis of mitochondrial sequences suggested that Gough Island mice belong to Mus musculus domesticus, with the maternal lineage possibly originating in England or France. Cluster analyses of microsatellites revealed genetic membership for Gough Island mice in multiple coastal populations in Western Europe, suggesting admixed ancestry. Gough Island mice showed substantial reductions in mitochondrial and nuclear sequence variation and weak reductions in microsatellite diversity compared with Western European populations, consistent with a population bottleneck. Approximate Bayesian computation (ABC) estimated that mice recently colonized Gough Island (~100 years ago) and experienced a 98% reduction in population size followed by a rapid expansion. Our results indicate that the unusual phenotypes of Gough Island mice evolved rapidly, positioning these mice as useful models for understanding rapid phenotypic evolution.

  7. Genetic differentiation and demographic history in Drosophila pachea from the Sonoran Desert.

    PubMed

    Pfeiler, Edward; Erez, Tamar; Hurtado, Luis A; Markow, Therese A

    2007-05-01

    Genetic variation at six microsatellite DNA loci and a segment of the mitochondrial cytochrome oxidase subunit I (COI) locus was used to estimate gene flow, population structure, and demographic history in the cactophilic Drosophila pachea from the Sonoran Desert of North America, a species that shows a strict association with its senita host cactus (genus Lophocereus). For microsatellite analyses, thirteen populations of D. pachea were sampled, five in mainland Mexico and the southwestern USA, and eight on the Baja California (Baja) peninsula, covering essentially the entire range of the species. Analysis of molecular variance (AMOVA) of microsatellite data revealed that populations from both the mainland and the Baja peninsula generally showed little structure, although there were a few exceptions, suggesting some local differentiation and restriction of gene flow within both regions. Pairwise comparisons of F(ST) among each of the mainland and Baja populations showed evidence of both panmixia and population subdivision. AMOVA performed on grouped populations from both the mainland and Baja, however, revealed significant partitioning of genetic variation among the two regions, but no partitioning among localities within each region. Bayesian skyline analyses of the COI data set, consisting of four mainland and seven peninsular populations, revealed population expansions dating to the Pleistocene or late Pliocene in D. pachea from both regions, although regional differences were seen in the estimated timing of the expansions and in changes in effective population size over time.

  8. Diversification, Biogeographic Pattern, and Demographic History of Taiwanese Scutellaria Species Inferred from Nuclear and Chloroplast DNA

    PubMed Central

    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. PMID:23226402

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

    PubMed

    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.

  10. Evaluation of demographic history and neutral parameterization on the performance of FST outlier tests.

    PubMed

    Lotterhos, Katie E; Whitlock, Michael C

    2014-05-01

    F(ST) outlier tests are a potentially powerful way to detect genetic loci under spatially divergent selection. Unfortunately, the extent to which these tests are robust to nonequilibrium demographic histories has been understudied. We developed a landscape genetics simulator to test the effects of isolation by distance (IBD) and range expansion on FST outlier methods. We evaluated the two most commonly used methods for the identification of F(ST) outliers (FDIST2 and BayeScan, which assume samples are evolutionarily independent) and two recent methods (FLK and Bayenv2, which estimate and account for evolutionary nonindependence). Parameterization with a set of neutral loci ('neutral parameterization') always improved the performance of FLK and Bayenv2, while neutral parameterization caused FDIST2 to actually perform worse in the cases of IBD or range expansion. BayeScan was improved when the prior odds on neutrality was increased, regardless of the true odds in the data. On their best performance, however, the widely used methods had high false-positive rates for IBD and range expansion and were outperformed by methods that accounted for evolutionary nonindependence. In addition, default settings in FDIST2 and BayeScan resulted in many false positives suggesting balancing selection. However, all methods did very well if a large set of neutral loci is available to create empirical P-values. We conclude that in species that exhibit IBD or have undergone range expansion, many of the published FST outliers based on FDIST2 and BayeScan are probably false positives, but FLK and Bayenv2 show great promise for accurately identifying loci under spatially divergent selection.

  11. The Joint Cruise Missiles Project: An Acquisition History

    DTIC Science & Technology

    1982-08-01

    production, fixed- price -incentive-fee contracts were used, and as development matures the contracts are being shifted to firm fixed price . Multi... Evolution of the Joint Project Office ................................. 12 Cruise Missile Project Commonality ................................. 21...the topics is contained in the appendixes, which are referenced throughout the text. EVOLUTION OF THE JOINT PROJECT OFFICE In 1973, the Joint Logistics

  12. Demographic Divergence History of Pied Flycatcher and Collared Flycatcher Inferred from Whole-Genome Re-sequencing Data

    PubMed Central

    Nadachowska-Brzyska, Krystyna; Burri, Reto; Olason, Pall I.; Kawakami, Takeshi; Smeds, Linnéa; Ellegren, Hans

    2013-01-01

    Profound knowledge of demographic history is a prerequisite for the understanding and inference of processes involved in the evolution of population differentiation and speciation. Together with new coalescent-based methods, the recent availability of genome-wide data enables investigation of differentiation and divergence processes at unprecedented depth. We combined two powerful approaches, full Approximate Bayesian Computation analysis (ABC) and pairwise sequentially Markovian coalescent modeling (PSMC), to reconstruct the demographic history of the split between two avian speciation model species, the pied flycatcher and collared flycatcher. Using whole-genome re-sequencing data from 20 individuals, we investigated 15 demographic models including different levels and patterns of gene flow, and changes in effective population size over time. ABC provided high support for recent (mode 0.3 my, range <0.7 my) species divergence, declines in effective population size of both species since their initial divergence, and unidirectional recent gene flow from pied flycatcher into collared flycatcher. The estimated divergence time and population size changes, supported by PSMC results, suggest that the ancestral species persisted through one of the glacial periods of middle Pleistocene and then split into two large populations that first increased in size before going through severe bottlenecks and expanding into their current ranges. Secondary contact appears to have been established after the last glacial maximum. The severity of the bottlenecks at the last glacial maximum is indicated by the discrepancy between current effective population sizes (20,000–80,000) and census sizes (5–50 million birds) of the two species. The recent divergence time challenges the supposition that avian speciation is a relatively slow process with extended times for intrinsic postzygotic reproductive barriers to evolve. Our study emphasizes the importance of using genome-wide data to

  13. Joint motion pattern classification by cluster analysis of kinematic, demographic, and subjective variables.

    PubMed

    Hwang, Jaejin; Shin, Hyunjung; Jung, Myung-Chul

    2013-07-01

    The purpose of this study is to identify joint motion patterns by classifying the full range of motion (ROM) into several sections. Forty participants were stratified by age and gender and they performed 18 full-swing motions at a self-selected speed. Joint angle, angular velocity, angular acceleration, and subjective discomfort rating were collected for each motion. K-means cluster analyses were used to classify joint motion patterns and ROM sections. The results showed that two or three clusters were mainly determined by the kinematic variables of angular velocity and acceleration. The motions of three clusters showed that the ROM sections of low and moderate velocity with moderate and high accelerations occurred in the initial (negative) and terminal (positive) phases, respectively, whereas those of high velocity with low acceleration were shown in the mid (neutral) phase. The motions of two clusters revealed that while the patterns of high velocity and high acceleration were found on the positive side of the ROM, those of low velocity and low acceleration were on the negative and neutral sides. The ROM sections close to both ends of the ROM may have a larger physical load than the others. This study provides information that could be useful for developing postural analysis tools for dynamic work.

  14. Impact of Demographics, Sexual History, and Psychological Functioning on the Acquisition of STDs in Adolescents.

    ERIC Educational Resources Information Center

    Rosenthal, Susan L.; Biro, Frank M.; Succop, Paul A.; Bernstein, David I.; Stanberry, Lawrence R.

    1997-01-01

    Examines the variables related to multiple episodes of sexually transmitted disease (STD) among adolescent females (n=88) and males (n=44). Results indicate that acquisition of an STD is related to the demographic characteristics of age and gender, as well as to the number of lifetime partners and attitudes about STD acquisition. (RJM)

  15. A survey of temporomandibular joint dislocation: aetiology, demographics, risk factors and management in 96 Nigerian cases.

    PubMed

    Ugboko, V I; Oginni, F O; Ajike, S O; Olasoji, H O; Adebayo, E T

    2005-07-01

    A retrospective study of 96 cases of temporomandibular joint dislocation was undertaken. Patients' ages ranged from 9 to 85 years (mean+/-SD, 35.3+/-17.4 years) and peak incidence was at 20-29 years. Mean duration was 7.9 weeks (range, 1h to 3 years). Acute, chronic and recurrent dislocations were seen in 46 (47.9%), 29 (30.2%) and 21 (21.9%) patients, respectively. Males dominated in all three categories but this was not statistically significant (P = 0.8). Excessive mouth opening while yawning (44 cases) was the commonest cause of dislocation, followed by road traffic accidents (13 cases). Ten patients (10.4%) had an underlying systemic disease, the commonest being epilepsy (four cases); those with acute dislocation recorded the highest incidence of underlying illness. Bilateral anterior (86 cases) dislocations were the most frequent. Of the 96 patients, 89 (92.7%) were available for treatment. Manual reduction with or without anaesthesia proved effective for 38/45 acute, 5/24 chronic and 14/20 recurrent cases. Chronic dislocations were treated mainly by surgical osteotomy (13/24). Vertical subsigmoid and oblique ramus osteotomies were the commonest surgical techniques recorded. Treatment was satisfactory for all patients surgically handled except for one case of anterior open bite postoperatively. This study has shown that excessive mouth opening while yawning is the commonest cause of temporomandibular joint dislocation in Nigerians, and conservative approaches to management remain quite effective irrespective of the duration and clinical subtype. The best choice of surgical technique should be determined by proper clinical evaluation and the need to avoid or minimize postoperative morbidity.

  16. Lower extremity joint position sense in runners with and without a history of knee overuse injury.

    PubMed

    Foch, Eric; Milner, Clare E

    2012-07-01

    Kinematic and kinetic analyses are routinely implemented to determine if gait differences exist between runners with and without a history of knee injury. Hip and knee kinematic differences have been reported between knee injured and non-injured runners. Yet, there is no consensus on whether these differences are the primary variables contributing to knee injury. Furthermore, there may be additional underlying factors that contribute to the development of injury that cannot be determined by gait analysis. The purpose of this investigation was to determine if joint position sense differences exist in runners with and without a history of knee overuse injury. Sagittal plane knee and hip joint position sense was measured in 13 runners with a history of knee overuse injury and 13 runners with no history of knee overuse injury. Absolute joint position replication error was measured during both a weight bearing and a non-weight bearing condition. Joint position replication errors at each joint were compared among groups and task using a two-way ANOVA with joint task as the repeated measure. Knee and hip joint replication errors were similar between both groups. The weight bearing and non-weight bearing tasks resulted in similar joint position replication errors. There were no interaction effects. In conclusion, knee flexion and hip adduction joint position sense is similar in runners with and without a history of knee overuse injury. Therefore, joint position sense measured via weight bearing and non-weight bearing joint position replication tasks may not play an important role in the development of knee overuse injury.

  17. United States -- Mexican joint ventures: A case history approach

    SciTech Connect

    Moore, N.L.; Chidester, R.J.; Hughes, K.R.; Fowler, R.A.

    1993-03-01

    Because the Mexican government has encouraged investment in Mexico by increasing the percentage of ownership of a Mexican business that a US company can hold, joint ventures are more attractive now than they had been in the past. This study provides preliminary information for US renewable energy companies who are interested in forming a joint venture with a Mexican company. This report is not intended to be a complete reference but does identifies a number of important factors that should be observed when forming a Mexican joint venture: (1)Successful joint ventures achieve the goals of each partner. (2)It is essential that all parties agree to the allocation of responsibilities. (3)Put everything in writing. (4)Research in depth the country or countries in which you are considering doing business.

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

    PubMed

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

    PubMed Central

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

    2016-01-01

    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. PMID:26823447

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

    PubMed

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

    2012-08-23

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

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed

    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.

  3. Altitudinal variation of demographic life-history traits does not mimic latitudinal variation in natterjack toads (Bufo calamita).

    PubMed

    Oromi, Neus; Sanuy, Delfi; Sinsch, Ulrich

    2012-02-01

    In anuran amphibians, age- and size-related life-history traits vary along latitudinal and altiudinal gradients. In the present study, we tested the hypothesis that altitudinal and latitudinal effects cause similar responses by assessing demographic life-history traits in nine Bufo calamita populations inhabiting elevations from sea level to 2270 m. Skeletochronologically determined age at maturity and longevity increased at elevations exceeding 2000 m, but female potential reproductive lifespan (PRLS) did not increase with altitude, as it did with latitude. Integrating the available evidence, it was found that lifetime fecundity of natterjacks decreased at the upper altitudinal range because PRLS was about the same as in lowland populations but females were smaller. In contrast, small size of northern females was compensated for by increased PRLS which minimised latitudinal variation of lifetime fecundity. Thus, this study provides evidence that altitudinal effects on life-history traits do not mimic latitudinal effects. Life-history trait variation along the altitudinal gradient seems to respond directly to the shortening of the annual activity period. As there is no evidence for increasing mortality in highland populations, reduced lifetime fecundity may be the ultimate reason for the natterjacks' inability to colonise elevations exceeding 2500 m.

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

    NASA Astrophysics Data System (ADS)

    Dodd, R. S.

    2009-04-01

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

  5. Relationships among and between ELL Status, Demographic Characteristics, Enrollment History, and School Persistence. CRESST Report 810

    ERIC Educational Resources Information Center

    Kim, Jinok

    2011-01-01

    This report examines enrollment history, achievement gaps, and persistence in school for ELL students and reclassified ELL students as compared to non-ELL students. The study uses statewide individual-level data sets merged from students' entry to exit in the state's public school system for graduate cohorts of 2006, 2007, and 2008. Analytic…

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

    PubMed Central

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

    2014-01-01

    The importance of evolutionary conservation – how understanding evolutionary forces can help guide conservation decisions – is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) – an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral Ne of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation. PMID:25553073

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

    PubMed

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

    2008-01-01

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

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

    PubMed

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

    2014-01-01

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

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

    PubMed

    Patin, Etienne; Laval, Guillaume; Barreiro, Luis B; Salas, Antonio; Semino, Ornella; Santachiara-Benerecetti, Silvana; Kidd, Kenneth K; Kidd, Judith R; Van der Veen, Lolke; Hombert, Jean-Marie; Gessain, Antoine; Froment, Alain; Bahuchet, Serge; Heyer, Evelyne; Quintana-Murci, Lluís

    2009-04-01

    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.

  10. Genetic diversity, population structure, effective population size and demographic history of the Finnish wolf population.

    PubMed

    Aspi, J; Roininen, E; Ruokonen, M; Kojola, I; Vilà, C

    2006-05-01

    The Finnish wolf population (Canis lupus) was sampled during three different periods (1996-1998, 1999-2001 and 2002-2004), and 118 individuals were genotyped with 10 microsatellite markers. Large genetic variation was found in the population despite a recent demographic bottleneck. No spatial population subdivision was found even though a significant negative relationship between genetic relatedness and geographic distance suggested isolation by distance. Very few individuals did not belong to the local wolf population as determined by assignment analyses, suggesting a low level of immigration in the population. We used the temporal approach and several statistical methods to estimate the variance effective size of the population. All methods gave similar estimates of effective population size, approximately 40 wolves. These estimates were slightly larger than the estimated census size of breeding individuals. A Bayesian model based on Markov chain Monte Carlo simulations indicated strong evidence for a long-term population decline. These results suggest that the contemporary wolf population size is roughly 8% of its historical size, and that the population decline dates back to late 19th century or early 20th century. Despite an increase of over 50% in the census size of the population during the whole study period, there was only weak evidence that the effective population size during the last period was higher than during the first. This may be caused by increased inbreeding, diminished dispersal within the population, and decreased immigration to the population during the last study period.

  11. Khoisan hunter-gatherers have been the largest population throughout most of modern-human demographic history

    PubMed Central

    Kim, Hie Lim; Ratan, Aakrosh; Perry, George H.; Montenegro, Alvaro; Miller, Webb; Schuster, Stephan C.

    2014-01-01

    The Khoisan people from Southern Africa maintained ancient lifestyles as hunter-gatherers or pastoralists up to modern times, though little else is known about their early history. Here we infer early demographic histories of modern humans using whole-genome sequences of five Khoisan individuals and one Bantu speaker. Comparison with a 420 K SNP data set from worldwide individuals demonstrates that two of the Khoisan genomes from the Ju/’hoansi population contain exclusive Khoisan ancestry. Coalescent analysis shows that the Khoisan and their ancestors have been the largest populations since their split with the non-Khoisan population ~100–150 kyr ago. In contrast, the ancestors of the non-Khoisan groups, including Bantu-speakers and non-Africans, experienced population declines after the split and lost more than half of their genetic diversity. Paleoclimate records indicate that the precipitation in southern Africa increased ~80–100 kyr ago while west-central Africa became drier. We hypothesize that these climate differences might be related to the divergent-ancient histories among human populations. PMID:25471224

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

    PubMed Central

    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

  13. Whole-genome sequence analyses of Western Central African Pygmy hunter-gatherers reveal a complex demographic history and identify candidate genes under positive natural selection

    PubMed Central

    Hsieh, PingHsun; Veeramah, Krishna R.; Lachance, Joseph; Tishkoff, Sarah A.; Wall, Jeffrey D.; Hammer, Michael F.; Gutenkunst, Ryan N.

    2016-01-01

    African Pygmies practicing a mobile hunter-gatherer lifestyle are phenotypically and genetically diverged from other anatomically modern humans, and they likely experienced strong selective pressures due to their unique lifestyle in the Central African rainforest. To identify genomic targets of adaptation, we sequenced the genomes of four Biaka Pygmies from the Central African Republic and jointly analyzed these data with the genome sequences of three Baka Pygmies from Cameroon and nine Yoruba famers. To account for the complex demographic history of these populations that includes both isolation and gene flow, we fit models using the joint allele frequency spectrum and validated them using independent approaches. Our two best-fit models both suggest ancient divergence between the ancestors of the farmers and Pygmies, 90,000 or 150,000 yr ago. We also find that bidirectional asymmetric gene flow is statistically better supported than a single pulse of unidirectional gene flow from farmers to Pygmies, as previously suggested. We then applied complementary statistics to scan the genome for evidence of selective sweeps and polygenic selection. We found that conventional statistical outlier approaches were biased toward identifying candidates in regions of high mutation or low recombination rate. To avoid this bias, we assigned P-values for candidates using whole-genome simulations incorporating demography and variation in both recombination and mutation rates. We found that genes and gene sets involved in muscle development, bone synthesis, immunity, reproduction, cell signaling and development, and energy metabolism are likely to be targets of positive natural selection in Western African Pygmies or their recent ancestors. PMID:26888263

  14. Phylogeography of Chinese cherry (Prunus pseudocerasus Lindl.) inferred from chloroplast and nuclear DNA: insights into evolutionary patterns and demographic history.

    PubMed

    Chen, T; Chen, Q; Luo, Y; Huang, Z-L; Zhang, J; Tang, H-R; Pan, D-M; Wang, X-R

    2015-07-01

    Chinese cherry (Prunus pseudocerasus Lindl.) is a commercially valuable fruit crop in China. In order to obtain new insights into its evolutionary history and provide valuable recommendations for resource conservation, phylogeographic patterns of 26 natural populations (305 total individuals) from six geographic regions were analyzed using chloroplast and nuclear DNA fragments. Low levels of haplotype and nucleotide diversity were found in these populations, especially in landrace populations. It is likely that a combined effect of botanical characteristics impact the effective population size, such as inbreeding mating system, long life span, as well as vegetative reproduction. In addition, strong bottleneck effect caused by domestication, together with founder effect after dispersal and subsequent demographic expansion, might also accelerate the reduction of the genetic variation in landrace populations. Interestingly, populations from Longmen Mountain (LMM) and Daliangshan Mountain (DLSM) exhibited relatively higher levels of genetic diversity, inferring the two historical genetic diversity centers of the species. Moreover, moderate population subdivision was also detected by both chloroplast DNA (GST = 0.215; NST = 0.256) and nuclear DNA (GST = 0.146; NST = 0.342), respectively. We inferred that the episodes of efficient gene flow through seed dispersal, together with features of long generation cycle and inbreeding mating system, were likely the main contributors causing the observed phylogeographic patterns. Finally, factors that led to the present demographic patterns of populations from these regions and taxonomic varieties were also discussed.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Demographic history, marker variability and genetic differentiation in sandy beach fauna: What is the meaning of low FST's?

    NASA Astrophysics Data System (ADS)

    Bezuidenhout, Karien; Nel, Ronel; Hauser, Lorenz

    2014-10-01

    This note demonstrates the effect of locus variability and demographic history on the estimation of genetic differentiation and its interpretation in terms of ecological connectivity. Cytochrome c oxidase subunit I (COI, mtDNA) sequences of the beach clam Donax serra from four sites along the South African coast were analysed. D. serra showed low COI haplotype diversity (h = 0.30 ± 0.069, 7 haplotypes), suggesting expansion from a small source population into extant habitats. As a consequence, statistical power to measure genetic connectivity was low. The lack of genetic population structure therefore does not necessarily demonstrate high connectivity. Although COI has been used successfully to identify species and populations isolated for prolonged periods of time, lack of differentiation has to be interpreted with caution, especially in terms of extant patterns of connectivity.

  17. [Mitochondrial DNA sequence variation, demographic history, and population structure of Amur sturgeon Acipenser schrenckii Brandt, 1869].

    PubMed

    Shedko, S V; Miroshnichenko, I L; Nemkova, G A; Koshelev, V N; Shedko, M B

    2015-02-01

    The variability of the mtDNA control region (D-loop) was examined in Amur sturgeon endemic to the Amur River. This species is also classified as critically endangered by the IUCN Red List of Threatened species. Sequencing of 796- to 812-bp fragments of the D-loop in 112 sturgeon collected in the Lower Amur revealed 73 different genotypes. The sample was characterized by a high level of haplotypic (0.976) and nucleotide (0.0194) diversity. The identified haplotypes split into two well-defined monophyletic groups, BG (n = 39) and SM (n = 34), differing (HKY distance) on average by 3.41% of nucleotide positions upon an average level of intragroup differences of 0.54 and 1.23%, respectively. Moreover, the haplotypes of the SM groups differed by the presence of a 13-14 bp deletion. Most ofthe samples (66 out of 112) carried BG haplotypes. Overall, the pattern of pairwise nucleotide differences and the results of neutrality tests, as well as the results of tests for compliance with the model of sudden demographic expansion or with the model of exponential growth pointed to a past significant increase in the number of Amur sturgeon, which was most clearly manifested in the analysis of data on the BG haplogroup. The constructed Bayesian skyline plots showed that this growth began about 18 to 16 thousand years ago. At present, the effective size of the strongly reduced (due to overharvesting) population of Amur sturgeon may be equal to or even lower than it was before the beginning of this growth during the Last Glacial Maximum. The presence in the mitochondrial gene pool ofAmur sturgeon of two haplogroups, their unequal evolutionary dynamics, and, judging by scanty data, their unequal representation in the Russian and Chinese parts of the Amur River basin point to the possible existence of at least two distinct populations of Amur sturgeon in the past.

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

    PubMed

    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.

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

    PubMed

    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. Utilizing Spatial Demographic and Life History Variation to Optimize Sustainable Yield of a Temperate Sex-Changing Fish

    PubMed Central

    Hamilton, Scott L.; Wilson, Jono R.; Ben-Horin, Tal; Caselle, Jennifer E.

    2011-01-01

    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 into fisheries

  1. Genetic diversity, genetic structure and demographic history of Cycas simplicipinna (Cycadaceae) assessed by DNA sequences and SSR markers

    PubMed Central

    2014-01-01

    Background Cycas simplicipinna (T. Smitinand) K. Hill. (Cycadaceae) is an endangered species in China. There were seven populations and 118 individuals that we could collect were genotyped in this study. Here, we assessed the genetic diversity, genetic structure and demographic history of this species. Results Analyses of data of DNA sequences (two maternally inherited intergenic spacers of chloroplast, cpDNA and one biparentally inherited internal transcribed spacer region ITS4-ITS5, nrDNA) and sixteen microsatellite loci (SSR) were conducted in the species. Of the 118 samples, 86 individuals from the seven populations were used for DNA sequencing and 115 individuals from six populations were used for the microsatellite study. We found high genetic diversity at the species level, low genetic diversity within each of the seven populations and high genetic differentiation among the populations. There was a clear genetic structure within populations of C. simplicipinna. A demographic history inferred from DNA sequencing data indicates that C. simplicipinna experienced a recent population contraction without retreating to a common refugium during the last glacial period. The results derived from SSR data also showed that C. simplicipinna underwent past effective population contraction, likely during the Pleistocene. Conclusions Some genetic features of C. simplicipinna such as having high genetic differentiation among the populations, a clear genetic structure and a recent population contraction could provide guidelines for protecting this endangered species from extinction. Furthermore, the genetic features with population dynamics of the species in our study would help provide insights and guidelines for protecting other endangered species effectively. PMID:25016306

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

    PubMed

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

    NASA Astrophysics Data System (ADS)

    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

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

    PubMed Central

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

    2015-01-01

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

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

    PubMed Central

    Tsutsui, Neil D.; Ramírez, Santiago R.

    2017-01-01

    The western honey bee, Apis mellifera, provides critical pollination services to agricultural crops worldwide. However, despite substantial interest and prior investigation, the early evolution and subsequent diversification of this important pollinator remain uncertain. The primary hypotheses place the origin of A. mellifera in either Asia or Africa, with subsequent radiations proceeding from one of these regions. Here, we use two publicly available whole-genome data sets plus newly sequenced genomes and apply multiple population genetic analysis methods to investigate the patterns of ancestry and admixture in native honey bee populations from Europe, Africa, and the Middle East. The combination of these data sets is critical to the analyses, as each contributes samples from geographic locations lacking in the other, thereby producing the most complete set of honey bee populations available to date. We find evidence supporting an origin of A. mellifera in the Middle East or North Eastern Africa, with the A and Y lineages representing the earliest branching lineages. This finding has similarities with multiple contradictory hypotheses and represents a disentangling of genetic relationships, geographic proximity, and secondary contact to produce a more accurate picture of the origins of A. mellifera. We also investigate how previous studies came to their various conclusions based on incomplete sampling of populations, and illustrate the importance of complete sampling in understanding evolutionary processes. These results provide fundamental knowledge about genetic diversity within Old World honey bee populations and offer insight into the complex history of an important pollinator. PMID:28164223

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

    PubMed

    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.

  7. Demographic history of Diadema antillarum, a keystone herbivore on Caribbean reefs.

    PubMed Central

    Lessios, H. A.; Garrido, M. J.; Kessing, B. D.

    2001-01-01

    The sea urchin Diadema antillarum was the most important herbivore on Caribbean reefs until 1983, when mass mortality reduced its populations by more than 97%. Knowledge of its past demography is essential to reconstruct reef ecology as it was before human impact, which has been implicated as having caused high pre-mortality Diadema abundance. To determine the history of its population size, we sequenced the ATPase 6 and 8 region of mitochondrial DNA from populations in the Caribbean and in the eastern Atlantic (which was not affected by the mass mortality), as well as from the eastern Pacific D. mexicanum. The Caribbean population harbours an order of magnitude more molecular diversity than those of the eastern Pacific or the eastern Atlantic and, despite the recent mass mortality, its DNA sequences bear the genetic signature of a previous population expansion. By estimating mutation rates from divergence between D. antillarum and D. mexicanum, that were separated at a known time by the Isthmus of Panama, and by using estimates of effective population size derived from mismatch distributions and a maximum likelihood coalescence algorithm, we date the expansion as having occurred no more recently than 100 000 years before the present. Thus, Diadema was abundant in the Caribbean long before humans could have affected ecological processes; the genetic data contain no evidence of a recent, anthropogenically caused, population increase. PMID:11703875

  8. Contrasting recombination patterns and demographic histories of the plant pathogen Ralstonia solanacearum inferred from MLSA

    PubMed Central

    Wicker, Emmanuel; Lefeuvre, Pierre; de Cambiaire, Jean-Charles; Lemaire, Christophe; Poussier, Stéphane; Prior, Philippe

    2012-01-01

    We used multilocus sequence analysis (MLSA) on a worldwide collection of the plant pathogenic Ralstonia solanacearum (Betaproteobacteria) to retrace its complex evolutionary history. Using genetic imprints left during R. solanacearum evolution, we were able to delineate distinct evolutionary complex displaying contrasting dynamics. Among the phylotypes already described (I, IIA, IIB, III, IV), eight groups of strains with distinct evolutionary patterns, named clades, were identified. From our recombination analysis, we identified 21 recombination events that occurred within and across these lineages. Although appearing the most divergent and ancestral phylotype, phylotype IV was inferred as a gene donor for the majority of the recombination events that we detected. Whereas this phylotype apparently fuelled the species diversity, ongoing diversification was mainly detected within phylotype I, IIA and III. These three groups presented a recent expanding population structure, a high level of homologous recombination and evidences of long-distance migrations. Factors such as adaptation to a specific host or intense trading of infected crops may have promoted this diversification. Whether R. solanacearum lineages will eventually evolve in distinct species remains an open question. The intensification of cropping and increase of geographical dispersion may favour situations of phylotype sympatry and promote higher exchange of key factors for host adaptation from their common genetic pool. PMID:22094345

  9. Population Genomic Analysis Reveals a Rich Speciation and Demographic History of Orang-utans (Pongo pygmaeus and Pongo abelii)

    PubMed Central

    Ma, Xin; Kelley, Joanna L.; Eilertson, Kirsten; Musharoff, Shaila; Degenhardt, Jeremiah D.; Martins, André L.; Vinar, Tomas; Kosiol, Carolin; Siepel, Adam; Gutenkunst, Ryan N.; Bustamante, Carlos D.

    2013-01-01

    To gain insights into evolutionary forces that have shaped the history of Bornean and Sumatran populations of orang-utans, we compare patterns of variation across more than 11 million single nucleotide polymorphisms found by previous mitochondrial and autosomal genome sequencing of 10 wild-caught orang-utans. Our analysis of the mitochondrial data yields a far more ancient split time between the two populations (∼3.4 million years ago) than estimates based on autosomal data (0.4 million years ago), suggesting a complex speciation process with moderate levels of primarily male migration. We find that the distribution of selection coefficients consistent with the observed frequency spectrum of autosomal non-synonymous polymorphisms in orang-utans is similar to the distribution in humans. Our analysis indicates that 35% of genes have evolved under detectable negative selection. Overall, our findings suggest that purifying natural selection, genetic drift, and a complex demographic history are the dominant drivers of genome evolution for the two orang-utan populations. PMID:24194868

  10. Population genomic analysis reveals a rich speciation and demographic history of orang-utans (Pongo pygmaeus and Pongo abelii).

    PubMed

    Ma, Xin; Kelley, Joanna L; Eilertson, Kirsten; Musharoff, Shaila; Degenhardt, Jeremiah D; Martins, André L; Vinar, Tomas; Kosiol, Carolin; Siepel, Adam; Gutenkunst, Ryan N; Bustamante, Carlos D

    2013-01-01

    To gain insights into evolutionary forces that have shaped the history of Bornean and Sumatran populations of orang-utans, we compare patterns of variation across more than 11 million single nucleotide polymorphisms found by previous mitochondrial and autosomal genome sequencing of 10 wild-caught orang-utans. Our analysis of the mitochondrial data yields a far more ancient split time between the two populations (~3.4 million years ago) than estimates based on autosomal data (0.4 million years ago), suggesting a complex speciation process with moderate levels of primarily male migration. We find that the distribution of selection coefficients consistent with the observed frequency spectrum of autosomal non-synonymous polymorphisms in orang-utans is similar to the distribution in humans. Our analysis indicates that 35% of genes have evolved under detectable negative selection. Overall, our findings suggest that purifying natural selection, genetic drift, and a complex demographic history are the dominant drivers of genome evolution for the two orang-utan populations.

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

    PubMed Central

    2012-01-01

    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. PMID:23020523

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

    USGS Publications Warehouse

    Ehlo, Chase A.; Layzer, James B.

    2014-01-01

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

  13. Demographic patterns of Ferocactus cylindraceus in relation to substrate age and grazing history

    USGS Publications Warehouse

    Bowers, Janice E.

    1997-01-01

    Three subpopulations of Ferocactus cylindraceus, a short-columnar cactus of the Sonoran and Mojave deserts, were sampled in Grand Canyon, Arizona, USA, at sites representing a range of substrate ages and different grazing histories. Age-height relations were determined from annual growth, then used to estimate probable year of establishment for each cohort. Eight years between 1944 and 1992 were especially favorable for establishment. Six of these 8 years coincided with El Nino-Southern Oscillation conditions, indicating that as for many woody plants in arid regions, somewhat unusual climatic conditions are necessary if populations are to replace themselves. Comparison of age structures showed that established and developing populations have somewhat different dynamics in that the rate of population increase was slowest on the youngest terrace. On the ancient terraces, about half the plants were less than 25 years old. Plants older than 40 years were few; however the oldest plants in the study (about 49 years) grew on the ancient terraces. On the recent terrace, 76% of the subpopulation was 25 years or younger, and the oldest living plant was about 36 years of age. The age structures of subpopulations on grazed and ungrazed sites also differed markedly. On ungrazed sites, subpopulations were more or less at equilibrium, with enough young plants to replace old ones as they died. In contrast, the subpopulation on the grazed site was in a state of marked disequilibrium. Grazing before 1981 largely extirpated a palatable subshrub that was probably an important nurse plant. Until the shrub population at Indian Canyon recovers from decades of burro grazing, a rebound in E cylindraceus establishment is not to be expected.

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

    PubMed Central

    2011-01-01

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

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

    PubMed

    Elias, Scott A

    2014-01-01

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

  16. Importance of demographic history for phylogeographic inference on the arctic–alpine plant Phyllodoce caerulea in East Asia

    PubMed Central

    Ikeda, H; Sakaguchi, S; Yakubov, V; Barkalov, V; Setoguchi, H

    2016-01-01

    Arctic–alpine plants have enormous ranges in the Northern Hemisphere. Phylogeographic studies have provided insights into their glacial survival as well as their postglacial colonization history. However, our understanding of the population dynamics of disjunct alpine populations in temperate regions remains limited. During Pleistocene cold periods, alpine populations of arctic–alpine species in East Asia were either connected to an ice-free Beringia refugium or they persisted with prolonged isolation after their establishment. To estimate which of these scenarios is more likely, we elucidated the genetic structure of Phyllodoce caerulea (Ericaceae) in Beringia and northern Japan, East Asia. Sequence variation in multiple nuclear loci revealed that P. caerulea can be distinguished into northern and southern groups. A demographic analysis demonstrated that the north–south divergence did not predate the last glacial period and detected introgression from Phyllodoce aleutica, relative widely distributed in East Asia, exclusively into the southern group. Therefore, although there has been genetic divergence between northern Japan and Beringia in P. caerulea, the divergence is unlikely to have resulted from their prolonged geographic separation throughout several cycles of glacial and interglacial periods. Instead, our study suggests that the introgression contributed to the genetic divergence of P. caerulea and that the range of P. caerulea was plausibly connected between northern Japan and Beringia during the last glacial period. Overall, our study not only provides a biogeographic insight into alpine populations of arctic–alpine plants in East Asia but also emphasizes the importance of careful interpretation of genetic structure for inferring phylogeographic history. PMID:26531250

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

    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.

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

    PubMed Central

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

    2015-01-01

    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. PMID:25977142

  20. Speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a species of conservation concern

    PubMed Central

    Gottscho, Andrew D; Marks, Sharyn B; Jennings, W Bryan

    2014-01-01

    The North American deserts were impacted by both Neogene plate tectonics and Quaternary climatic fluctuations, yet it remains unclear how these events influenced speciation in this region. We tested published hypotheses regarding the timing and mode of speciation, population structure, and demographic history of the Mojave Fringe-toed Lizard (Uma scoparia), a sand dune specialist endemic to the Mojave Desert of California and Arizona. We sampled 109 individual lizards representing 22 insular dune localities, obtained DNA sequences for 14 nuclear loci, and found that U. scoparia has low genetic diversity relative to the U. notata species complex, comparable to that of chimpanzees and southern elephant seals. Analyses of genotypes using Bayesian clustering algorithms did not identify discrete populations within U. scoparia. Using isolation-with-migration (IM) models and a novel coalescent-based hypothesis testing approach, we estimated that U. scoparia diverged from U. notata in the Pleistocene epoch. The likelihood ratio test and the Akaike Information Criterion consistently rejected nested speciation models that included parameters for migration and population growth of U. scoparia. We reject the Neogene vicariance hypothesis for the speciation of U. scoparia and define this species as a single evolutionarily significant unit for conservation purposes. PMID:25360285

  1. High-Dimensional Coexistence of Temperate Tree Species: Functional Traits, Demographic Rates, Life-History Stages, and Their Physical Context

    PubMed Central

    McMahon, Sean M.; Metcalf, Charlotte J. E.; Woodall, Christopher W.

    2011-01-01

    Theoretical models indicate that trade-offs between growth and survival strategies of tree species can lead to coexistence across life history stages (ontogeny) and physical conditions experienced by individuals. There exist predicted physiological mechanisms regulating these trade-offs, such as an investment in leaf characters that may increase survival in stressful environments at the expense of investment in bole or root growth. Confirming these mechanisms, however, requires that potential environmental, ontogenetic, and trait influences are analyzed together. Here, we infer growth and mortality of tree species given size, site, and light characteristics from forest inventory data from Wisconsin to test hypotheses about growth-survival trade-offs given species functional trait values under different ontogenetic and environmental states. A series of regression analyses including traits and rates their interactions with environmental and ontogenetic stages supported the relationships between traits and vital rates expected from the expectations from tree physiology. A combined model including interactions between all variables indicated that relationships between demographic rates and functional traits supports growth-survival trade-offs and their differences across species in high-dimensional niche space. The combined model explained 65% of the variation in tree growth and supports a concept of community coexistence similar to Hutchinson's n-dimensional hypervolume and not a low-dimensional niche model or neutral model. PMID:21305020

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

    PubMed Central

    2014-01-01

    Background Understanding the demographic history of a population is critical to conservation and to our broader understanding of evolutionary processes. For many tropical large mammals, however, this aim is confounded by the absence of fossil material and by the misleading signal obtained from genetic data of recently fragmented and isolated populations. This is particularly true for the lion which as a consequence of millennia of human persecution, has large gaps in its natural distribution and several recently extinct populations. Results We sequenced mitochondrial DNA from museum-preserved individuals, including the extinct Barbary lion (Panthera leo leo) and Iranian lion (P. l. persica), as well as lions from West and Central Africa. We added these to a broader sample of lion sequences, resulting in a data set spanning the historical range of lions. Our Bayesian phylogeographical analyses provide evidence for highly supported, reciprocally monophyletic lion clades. Using a molecular clock, we estimated that recent lion lineages began to diverge in the Late Pleistocene. Expanding equatorial rainforest probably separated lions in South and East Africa from other populations. West African lions then expanded into Central Africa during periods of rainforest contraction. Lastly, we found evidence of two separate incursions into Asia from North Africa, first into India and later into the Middle East. Conclusions We have identified deep, well-supported splits within the mitochondrial phylogeny of African lions, arguing for recognition of some regional populations as worthy of independent conservation. More morphological and nuclear DNA data are now needed to test these subdivisions. PMID:24690312

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

    PubMed

    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.

  4. WTCS Transfers to the University of Wisconsin System. Information on: Enrollment, Demographics, Outcomes, Conclusions. Joint Administrative Committee on Academic Programs.

    ERIC Educational Resources Information Center

    Wisconsin Univ. System, Madison.

    This document reports on enrollment, demographics, and outcomes for Wisconsin Technical College System (WTCS) transfers to the University of Wisconsin (UW) System. Enrollment Information presents findings on transfers within and into the UW System by year (1994-95 to 1997-98), illustrates the proportion of transfers within and into the UW System…

  5. The Impact of Demographic Changes on Social Programs. Joint Economic Committee, Ninety-Seventh Congress, Second Session.

    ERIC Educational Resources Information Center

    Joint Economic Committee, Washington, DC.

    The social policy implications of demographic trends are examined, to help policy makers anticipate future needs for services with greater accuracy. Crises such as energy needs and social security financing illustrate the need for greater recognition of the time dimension of public policy. Many of our most difficult problems, if they are to be…

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

    PubMed

    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.

  7. Reconstructing the Demographic History of the Human Lineage Using Whole-Genome Sequences from Human and Three Great Apes

    PubMed Central

    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 τHC differed across chromosomes, τHC and τHCG 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. PMID:22975719

  8. Five-year reliability of key demographic and life history data collected from self-respondents and next-of-kin.

    PubMed

    Sonderman, Jennifer S; Tarone, Robert E; McLaughlin, Joseph K

    2014-07-01

    The ability of study participants or their next-of-kin to provide basic demographic and life history data is of critical importance in epidemiologic studies and government surveys. Most interview studies to date have focused on the reliability of these variables either as self-reported over short periods of time (<2 years) or as reported by the next-of-kin concurrently with the study participant. In a unique reinterview study, the authors examine the concordance of responses 5 years after the initial interview among 196 surviving study participants and 107 next-of-kin respondents of participants who died after the first interview. The reliability of demographic, anthropometric, reproductive, and residential history questions was high overall, with most κ and Spearman rank-correlation coefficients being above 0.80 for both self-respondents and next-of-kin at reinterview in 1985. In particular, almost perfect agreement was observed for year of birth, religion raised, number of children, and age at first birth, whereas agreement was lowest for childhood residential history. Contrary to expectation, the next-of-kin responses were generally as reliable as those of the original participants themselves 5 years after the initial study, providing further support for the usefulness of surrogate respondents in collecting demographic and life history information in epidemiologic investigations when no other source is available.

  9. Joint palaeoclimate reconstruction from pollen data via forward models and climate histories

    NASA Astrophysics Data System (ADS)

    Parnell, Andrew C.; Haslett, John; Sweeney, James; Doan, Thinh K.; Allen, Judy R. M.; Huntley, Brian

    2016-11-01

    We present a method and software for reconstructing palaeoclimate from pollen data with a focus on accounting for and reducing uncertainty. The tools we use include: forward models, which enable us to account for the data generating process and hence the complex relationship between pollen and climate; joint inference, which reduces uncertainty by borrowing strength between aspects of climate and slices of the core; and dynamic climate histories, which allow for a far richer gamut of inferential possibilities. Through a Monte Carlo approach we generate numerous equally probable joint climate histories, each of which is represented by a sequence of values of three climate dimensions in discrete time, i.e. a multivariate time series. All histories are consistent with the uncertainties in the forward model and the natural temporal variability in climate. Once generated, these histories can provide most probable climate estimates with uncertainty intervals. This is particularly important as attention moves to the dynamics of past climate changes. For example, such methods allow us to identify, with realistic uncertainty, the past century that exhibited the greatest warming. We illustrate our method with two data sets: Laguna de la Roya, with a radiocarbon dated chronology and hence timing uncertainty; and Lago Grande di Monticchio, which contains laminated sediment and extends back to the penultimate glacial stage. The procedure is made available via an open source R package, Bclim, for which we provide code and instructions.

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

    PubMed

    Shi, Wentao; Ayub, Qasim; Vermeulen, Mark; Shao, Rong-guang; Zuniga, Sofia; van der Gaag, Kristiaan; de Knijff, Peter; Kayser, Manfred; Xue, Yali; Tyler-Smith, Chris

    2010-02-01

    We have investigated human male demographic history using 590 males from 51 populations in the Human Genome Diversity Project - Centre d'Etude du Polymorphisme Humain worldwide panel, typed with 37 Y-chromosomal Single Nucleotide Polymorphisms and 65 Y-chromosomal Short Tandem Repeats and analyzed with the program Bayesian Analysis of Trees With Internal Node Generation. The general patterns we observe show a gradient from the oldest population time to the most recent common ancestors (TMRCAs) and expansion times together with the largest effective population sizes in Africa, to the youngest times and smallest effective population sizes in the Americas. These parameters are significantly negatively correlated with distance from East Africa, and the patterns are consistent with most other studies of human variation and history. In contrast, growth rate showed a weaker correlation in the opposite direction. Y-lineage diversity and TMRCA also decrease with distance from East Africa, supporting a model of expansion with serial founder events starting from this source. A number of individual populations diverge from these general patterns, including previously documented examples such as recent expansions of the Yoruba in Africa, Basques in Europe, and Yakut in Northern Asia. However, some unexpected demographic histories were also found, including low growth rates in the Hazara and Kalash from Pakistan and recent expansion of the Mozabites in North Africa.

  11. Distinguishing the effects of selection from demographic history in the genetic variation of two sister passerines based on mitochondrial–nuclear comparison

    PubMed Central

    Hung, C-M; Zink, R M

    2014-01-01

    Determining the mechanisms responsible for the distribution of genetic diversity in natural populations has occupied a central role in molecular evolution. Our study was motivated by the unprecedented observation that a widespread Eurasian flycatcher, Ficedula albicilla, exhibited no variation at the mitochondrial DNA (mtDNA) ND2 gene in 75 individuals sampled over a 5000-km distance. In contrast, its sister species, F. parva, had low but considerably higher levels of mtDNA variation. We assessed whether natural selection or demographic factors could explain the absence of mtDNA variation in F. albicilla. Eighteen nuclear genes were sequenced to estimate the two species' phylogeographic histories, and for comparison to the mtDNA data. Multilocus coalescence analyses suggested that F. albicilla experienced a population expansion perhaps following a population bottleneck. Simulations based on this demographic history, however, did not replicate the extremely low level of mtDNA variation. Historical range changes based on ecological niche models also failed to explain the observed mtDNA patterns. Neutrality tests (DHEW and ML-HKA) suggested a non-neutral pattern in the mtDNA of F. albicilla. We found a transmembrane-skewed distribution of nonsynonymous substitutions between the two species, three of which caused functional change; the results implied that positive selection could have targeted mtDNA. Several lines of evidence support selection rather than demographic history as the main force influencing the patterns of mtDNA variation. Despite the influence of natural selection, many of the phylogeographic inferences derived from mtDNA were robust, including species limits and a high level of gene flow among populations within species. PMID:24619180

  12. Sealable joint steel sheet piling for groundwater control and remediation: Case histories

    SciTech Connect

    Smyth, D.; Jowett, R.; Gamble, M.

    1997-12-31

    The Waterloo Barrier{trademark} steel sheet piling (patents pending) incorporates a cavity at each interlocking joint that is flushed clean and injected with sealant after the piles have been driven into the ground to form a vertical cutoff wall. The installation and sealing procedures allow for a high degree of quality assurance and control. Bulk wall hydraulic conductivities of 10{sup -8} to 10{sup -10} cm/sec have been demonstrated at field installations. Recent case histories are presented in which Waterloo Barrier{trademark} cutoff walls are used to prevent off-site migration of contaminated groundwater or soil gases to adjacent property and waterways. Full enclosures to isolate DNAPL source zones or portions of contaminated aquifers for pilot-scale remediation testing will also be described. Monitoring data will be used to demonstrate the effectiveness of the Waterloo Barrier{trademark} in these applications.

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

    PubMed

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

    2016-09-15

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

  14. Strong population genetic structure and contrasting demographic histories for the small-spotted catshark (Scyliorhinus canicula) in the Mediterranean Sea.

    PubMed

    Kousteni, V; Kasapidis, P; Kotoulas, G; Megalofonou, P

    2015-03-01

    Coastal and demersal chondrichthyans, such as the small-spotted catshark, are expected to exhibit genetic differentiation in areas of complex geomorphology like the Mediterranean Basin because of their limited dispersal ability. To test this hypothesis, we used a fragment of the mitochondrial cytochrome c oxidase subunit I gene and 12 nuclear microsatellite loci in order to investigate the genetic structure and historical demography of this species, and to identify potential barriers to gene flow. Samples were collected from the Balearic Islands, the Algerian Basin, the Ionian Sea, the Corinthian Gulf and various locations across the Aegean Sea. Additional sequences from the Atlantic and the Levantine Basin retrieved from GenBank were included in the mitochondrial DNA analysis. Both mitochondrial and nuclear microsatellite DNA data revealed a strong genetic subdivision, mainly between the western and eastern Mediterranean, whereas the Levantine Basin shared haplotypes with both areas. The geographic isolation of the Mediterranean basins seems to enforce the population genetic differentiation of the species, with the deep sea acting as a strong barrier to its dispersal. Contrasting historical demographic patterns were also observed in different parts of the species' distribution, most notably a population growth trend in the western Mediterranean/Atlantic area and a slight decreasing one in the Aegean Sea. The different effects of the Pleistocene glacial periods on the habitat availability may explain the contrasting demographic patterns observed. The current findings suggest that the small-spotted catshark exhibits several genetic stocks in the Mediterranean, although further study is needed.

  15. Strong population genetic structure and contrasting demographic histories for the small-spotted catshark (Scyliorhinus canicula) in the Mediterranean Sea

    PubMed Central

    Kousteni, V; Kasapidis, P; Kotoulas, G; Megalofonou, P

    2015-01-01

    Coastal and demersal chondrichthyans, such as the small-spotted catshark, are expected to exhibit genetic differentiation in areas of complex geomorphology like the Mediterranean Basin because of their limited dispersal ability. To test this hypothesis, we used a fragment of the mitochondrial cytochrome c oxidase subunit I gene and 12 nuclear microsatellite loci in order to investigate the genetic structure and historical demography of this species, and to identify potential barriers to gene flow. Samples were collected from the Balearic Islands, the Algerian Basin, the Ionian Sea, the Corinthian Gulf and various locations across the Aegean Sea. Additional sequences from the Atlantic and the Levantine Basin retrieved from GenBank were included in the mitochondrial DNA analysis. Both mitochondrial and nuclear microsatellite DNA data revealed a strong genetic subdivision, mainly between the western and eastern Mediterranean, whereas the Levantine Basin shared haplotypes with both areas. The geographic isolation of the Mediterranean basins seems to enforce the population genetic differentiation of the species, with the deep sea acting as a strong barrier to its dispersal. Contrasting historical demographic patterns were also observed in different parts of the species' distribution, most notably a population growth trend in the western Mediterranean/Atlantic area and a slight decreasing one in the Aegean Sea. The different effects of the Pleistocene glacial periods on the habitat availability may explain the contrasting demographic patterns observed. The current findings suggest that the small-spotted catshark exhibits several genetic stocks in the Mediterranean, although further study is needed. PMID:25469687

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

    PubMed Central

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

    2014-01-01

    Background: Little is known about the epidemiology of suicide attempts among psychiatric outpatients in Mexico. This study was aimed to determine the socio-demographic, clinical and behavioral characteristics associated with suicide attempts in psychiatric outpatients in two public hospitals in Durango, Mexico. Methods: Two hundred seventy six psychiatric outpatients (154 suicide attempters and 122 patients without suicide attempt history) attended the two public hospitals in Durango City, Mexico were included in this study. Socio-demographic, clinical and behavioral characteristics were obtained retrospectively from all outpatients and compared in relation to the presence or absence of suicide attempt history. Results: Increased prevalence of suicide attempts was associated with mental and behavioral disorders due to psychoactive substance use (F10-19) (P=0.01), schizophrenia, schizotypal and delusional disorders (F20-29) (P=0.02), mood (affective) disorders (F30-39) (P<0.001), and disorders of adult personality and behavior (F60-69) (P<0.001). Multivariate analysis showed that suicide attempts were associated with young age (OR=1.21, 95% CI: 1.06-1.39; P=0.003), female gender (OR=2.98, 95% CI: 1.55-5.73; P=0.001), urban residence (OR=2.31, 95% CI: 1.17-4.57; P=0.01), memory impairment (OR=1.91, 95% CI: 1.07-3.40; P=0.02), alcohol consumption (OR=2.39, 95% CI: 1.21-4.70; P=0.01), and sexual promiscuity (OR=3.90, 95% CI: 1.74-8.77; P<0.001). Conclusions: We report the association of suicide attempts with socio-demographic, clinical and behavioral characteristics in psychiatric outpatients in Mexico. Results may be useful for an optimal planning of preventive measures against suicide attempts in psychiatric outpatients. PMID:24711751

  17. The joint effects of water and sanitation on diarrheal disease: A multi-country analysis of the Demographic and Health Surveys

    PubMed Central

    Fuller, James A.; Westphal, Joslyn A.; Kenney, Brooke; Eisenberg, Joseph N. S.

    2014-01-01

    Objectives To assess the joint effects of water and sanitation infrastructure, whether they are redundant services preventing the same cases of diarrheal disease, act independently, or act synergistically; and to assess how these effects vary by country and over time. Methods We used data from 217 Demographic and Health Surveys conducted in 90 countries between 1986 and 2013. We used modified Poisson regression to assess the impact of water and sanitation infra-structure on the prevalence of diarrhea among children under five. Results The impact of water and sanitation varied across surveys, and adjusting for socioeconomic status drove these estimates towards the null. Sanitation had a greater effect than water infrastructure when all 217 surveys were pooled; however, the impact of sanitation diminished over time. Based on survey data from the past ten years, we saw no evidence for benefits in improving drinking water or sanitation alone, but we estimated a 6% reduction of both combined (prevalence ratio = 0.94, 95% confidence limit 0.91-0.98). Conclusions Water and sanitation interventions should be combined to maximize the number of cases of diarrheal disease prevented in children under five. Further research should identify the sources of variability seen between countries and across time. These national surveys likely include substantial measurement error in the categorization of water and sanitation, making it difficult to interpret the roles of other pathways. PMID:25430739

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

    PubMed

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

    2014-10-01

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

  19. Comparing maternal genetic variation across two millennia reveals the demographic history of an ancient human population in southwest Turkey

    PubMed Central

    Ottoni, Claudio; Willet, Rinse; Claeys, Johan; Talloen, Peter; Van de Vijver, Katrien; Chikhi, Lounès; Poblome, Jeroen; Decorte, Ronny

    2016-01-01

    More than two decades of archaeological research at the site of Sagalassos, in southwest Turkey, resulted in the study of the former urban settlement in all its features. Originally settled in late Classical/early Hellenistic times, possibly from the later fifth century BCE onwards, the city of Sagalassos and its surrounding territory saw empires come and go. The Plague of Justinian in the sixth century CE, which is considered to have caused the death of up to a third of the population in Anatolia, and an earthquake in the seventh century CE, which is attested to have devastated many monuments in the city, may have severely affected the contemporary Sagalassos community. Human occupation continued, however, and Byzantine Sagalassos was eventually abandoned around 1200 CE. In order to investigate whether these historical events resulted in demographic changes across time, we compared the mitochondrial DNA variation of two population samples from Sagalassos (Roman and Middle Byzantine) and a modern sample from the nearby town of Ağlasun. Our analyses revealed no genetic discontinuity across two millennia in the region and Bayesian coalescence-based simulations indicated that a major population decline in the area coincided with the final abandonment of Sagalassos, rather than with the Plague of Justinian or the mentioned earthquake. PMID:26998313

  20. Population genomics shed light on the demographic and adaptive histories of European invasion in the Pacific oyster, Crassostrea gigas

    PubMed Central

    Rohfritsch, Audrey; Bierne, Nicolas; Boudry, Pierre; Heurtebise, Serge; Cornette, Florence; Lapègue, Sylvie

    2013-01-01

    Crassostrea gigas originated from the Pacific coast of Asia, but was introduced into several European countries in the early 1970s. Natural populations have now spread across the length of the western seaboard of Europe. To elucidate the demographic and selective processes at play during this rapid expansion, genome-scan analysis was performed on different populations. High diversities and low differentiation were observed overall, but significant genetic differentiation was found among newly established populations and between the newly established northern group and a nearly panmictic group composed of southern European populations and a population from Japan. Loss of genetic diversity was also seen in the north, likely caused by founder events during colonization. The few strongly supported outlier loci revealed a genetic structure uncorrelated with the north/south differentiation, but grouping two samples from the Danish fjords (northern group) and one from the Dutch Scheldt estuary (southern group) with the one from Japan. These findings might reflect the following: (i) parallel adaptation to similar environmental pressures (fjord-like environment) within each of the two groups or (ii) a footprint of a secondary introduction of an alternative genomic background maintained by multifarious isolation factors. Our results call for a closer examination of adaptive genetic structure in the area of origin. PMID:24187588

  1. Pragmatic Perspective on Conservation Genetics and Demographic History of the Last Surviving Population of Kashmir Red Deer (Cervus elaphus hanglu) in India

    PubMed Central

    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. PMID:25671567

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

    PubMed

    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.

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

    USGS Publications Warehouse

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

    2016-01-01

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

  4. Sea-level variations have influenced the demographic history of estuarine and freshwater fishes of the coastal plain of Paraná, Brazil.

    PubMed

    Tschá, M K; Baggio, R A; Marteleto, F M; Abilhoa, V; Bachmann, L; Boeger, W A

    2017-03-01

    This study surveyed the mitochondrial haplotype diversity of nine freshwater fish species and two estuarine-marine species from the coastal basins and drainages of the highland plateaus of Paraná, Brazil. Portions of the cytochrome b gene or the control region were sequenced. The demographic history of each species was inferred using the Bayesian skyline method, mismatch distribution analysis and statistical neutrality tests. Demographic reconstruction analyses revealed a single pattern of variation in the effective population size (Ne ) among species. No dramatic changes in Ne were detected in upland species. By contrast, evidence of population expansion over the past 200 000 years was detected in all coastal plain and estuarine species. These findings correspond to periods of low sea-level (regressions) followed by a rapid increase in the sea-level by >100 m. The resulting reconnections and subsequent fragmentation and isolation between the estuarine and freshwater bodies were putatively relevant to the historical demography of the fish species in these areas.

  5. Phylogeography across a continent: the evolutionary and demographic history of the North American racer (Serpentes: Colubridae: Coluber constrictor).

    PubMed

    Burbrink, Frank T; Fontanella, Frank; Alexander Pyron, R; Guiher, Timothy J; Jimenez, Cynthia

    2008-04-01

    Most phylogeographic studies examine organisms that do not have transcontinental distributions and therefore the genetic and temporal effects of barriers across an entire continent cannot be assessed with respect to a single species. We examined the phylogeographic structure, lineage age, and historical demography using sequences from the mtDNA cytochrome b gene of the widespread North American racer (Coluber constrictor), one of the few abundant transcontinental snakes that occurs throughout many diverse biomes. Our results indicate that this complex is comprised of six lineages differing greatly in geographic extent, with the largest (a central US clade) being approximately 26 times greater than the smallest (a lineage restricted to the Florida Panhandle and nearby portions of adjacent States). Most of the six lineages appear to be separated at previously identified genetic barriers for several vertebrates with similar ranges. Lineage diversification in this species began in the late Miocene, separating populations in the Florida Peninsula from the remainder of the US. Diversification of lineages continued throughout the Pliocene and early Pleistocene. Four of the six lineages occur east of the Mississippi River, with only two distinctly young ( approximately 1.5 mya) lineages found west of the Mississippi River (one occurs west of Continental Divide). All methods of demographic inference, including the mismatch distribution, Fu and Li's D and Tajima's D , and Bayesian skyline plots revealed population expansion occurring in the mid-to-late Pleistocene for every lineage, regardless of size or proximity to formerly glaciated areas. Population expansion for lineages found east of the Mississippi River occurred earlier and was much greater than those found west of the River.

  6. Selection and demographic history shape the molecular evolution of the gamete compatibility protein bindin in Pisaster sea stars

    PubMed Central

    Popovic, Iva; Marko, Peter B; Wares, John P; Hart, Michael W

    2014-01-01

    Reproductive compatibility proteins have been shown to evolve rapidly under positive selection leading to reproductive isolation, despite the potential homogenizing effects of gene flow. This process has been implicated in both primary divergence among conspecific populations and reinforcement during secondary contact; however, these two selective regimes can be difficult to discriminate from each other. Here, we describe the gene that encodes the gamete compatibility protein bindin for three sea star species in the genus Pisaster. First, we compare the full-length bindin-coding sequence among all three species and analyze the evolutionary relationships between the repetitive domains of the variable second bindin exon. The comparison suggests that concerted evolution of repetitive domains has an effect on bindin divergence among species and bindin variation within species. Second, we characterize population variation in the second bindin exon of two species: We show that positive selection acts on bindin variation in Pisaster ochraceus but not in Pisaster brevispinus, which is consistent with higher polyspermy risk in P. ochraceus. Third, we show that there is no significant genetic differentiation among populations and no apparent effect of sympatry with congeners that would suggest selection based on reinforcement. Fourth, we combine bindin and cytochrome c oxidase 1 data in isolation-with-migration models to estimate gene flow parameter values and explore the historical demographic context of our positive selection results. Our findings suggest that positive selection on bindin divergence among P. ochraceus alleles can be accounted for in part by relatively recent northward population expansions that may be coupled with the potential homogenizing effects of concerted evolution. PMID:24967076

  7. Selection and demographic history shape the molecular evolution of the gamete compatibility protein bindin in Pisaster sea stars.

    PubMed

    Popovic, Iva; Marko, Peter B; Wares, John P; Hart, Michael W

    2014-05-01

    Reproductive compatibility proteins have been shown to evolve rapidly under positive selection leading to reproductive isolation, despite the potential homogenizing effects of gene flow. This process has been implicated in both primary divergence among conspecific populations and reinforcement during secondary contact; however, these two selective regimes can be difficult to discriminate from each other. Here, we describe the gene that encodes the gamete compatibility protein bindin for three sea star species in the genus Pisaster. First, we compare the full-length bindin-coding sequence among all three species and analyze the evolutionary relationships between the repetitive domains of the variable second bindin exon. The comparison suggests that concerted evolution of repetitive domains has an effect on bindin divergence among species and bindin variation within species. Second, we characterize population variation in the second bindin exon of two species: We show that positive selection acts on bindin variation in Pisaster ochraceus but not in Pisaster brevispinus, which is consistent with higher polyspermy risk in P. ochraceus. Third, we show that there is no significant genetic differentiation among populations and no apparent effect of sympatry with congeners that would suggest selection based on reinforcement. Fourth, we combine bindin and cytochrome c oxidase 1 data in isolation-with-migration models to estimate gene flow parameter values and explore the historical demographic context of our positive selection results. Our findings suggest that positive selection on bindin divergence among P. ochraceus alleles can be accounted for in part by relatively recent northward population expansions that may be coupled with the potential homogenizing effects of concerted evolution.

  8. The use of microsatellite variation to infer population structure and demographic history in a natural model system.

    PubMed

    Goldstein, D B; Roemer, G W; Smith, D A; Reich, D E; Bergman, A; Wayne, R K

    1999-02-01

    To assess the reliability of genetic markers it is important to compare inferences that are based on them to a priori expectations. In this article we present an analysis of microsatellite variation within and among populations of island foxes (Urocyon littoralis) on California's Channel Islands. We first show that microsatellite variation at a moderate number of loci (19) can provide an essentially perfect description of the boundaries between populations and an accurate representation of their historical relationships. We also show that the pattern of variation across unlinked microsatellite loci can be used to test whether population size has been constant or increasing. Application of these approaches to the island fox system indicates that microsatellite variation may carry considerably more information about population history than is currently being used.

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

    PubMed

    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.

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

    PubMed

    Nakagome, Shigeki; Mano, Shuhei; Hasegawa, Masami

    2013-01-01

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

  11. Measuring concurrency using a joint multistate and point process model for retrospective sexual history data.

    PubMed

    Aralis, Hilary J; Gorbach, Pamina M; Brookmeyer, Ron

    2016-10-30

    Understanding the impact of concurrency, defined as overlapping sexual partnerships, on the spread of HIV within various communities has been complicated by difficulties in measuring concurrency. Retrospective sexual history data consisting of first and last dates of sexual intercourse for each previous and ongoing partnership is often obtained through use of cross-sectional surveys. Previous attempts to empirically estimate the magnitude and extent of concurrency among these surveyed populations have inadequately accounted for the dependence between partnerships and used only a snapshot of the available data. We introduce a joint multistate and point process model in which states are defined as the number of ongoing partnerships an individual is engaged in at a given time. Sexual partnerships starting and ending on the same date are referred to as one-offs and modeled as discrete events. The proposed method treats each individual's continuation in and transition through various numbers of ongoing partnerships as a separate stochastic process and allows the occurrence of one-offs to impact subsequent rates of partnership formation and dissolution. Estimators for the concurrent partnership distribution and mean sojourn times during which a person has k ongoing partnerships are presented. We demonstrate this modeling approach using epidemiological data collected from a sample of men having sex with men and seeking HIV testing at a Los Angeles clinic. Among this sample, the estimated point prevalence of concurrency was higher among men later diagnosed HIV positive. One-offs were associated with increased rates of subsequent partnership dissolution. Copyright © 2016 John Wiley & Sons, Ltd.

  12. Systematic review of patient history and physical examination to diagnose chronic low back pain originating from the facet joints.

    PubMed

    Maas, E T; Juch, J N S; Ostelo, R W J G; Groeneweg, J G; Kallewaard, J W; Koes, B W; Verhagen, A P; Huygen, F J P M; van Tulder, M W

    2017-03-01

    Patient history and physical examination are frequently used procedures to diagnose chronic low back pain (CLBP) originating from the facet joints, although the diagnostic accuracy is controversial. The aim of this systematic review is to determine the diagnostic accuracy of patient history and/or physical examination to identify CLBP originating from the facet joints using diagnostic blocks as reference standard. We searched MEDLINE, EMBASE, CINAHL, Web of Science and the Cochrane Collaboration database from inception until June 2016. Two review authors independently selected studies for inclusion, extracted data and assessed the risk of bias. We calculated sensitivity and specificity values, with 95% confidence intervals (95% CI). Twelve studies were included, in which 129 combinations of index tests and reference standards were presented. Most of these index tests have only been evaluated in single studies with a high risk of bias. Four studies evaluated the diagnostic accuracy of the Revel's criteria combination. Because of the clinical heterogeneity, results were not pooled. The published sensitivities ranged from 0.11 (95% CI 0.02-0.29) to 1.00 (95% CI 0.75-1.00), and the specificities ranged from 0.66 (95% CI 0.46-0.82) to 0.91 (95% CI 0.83-0.96). Due to clinical heterogeneity, the evidence for the diagnostic accuracy of patient history and/or physical examination to identify facet joint pain is inconclusive. Patient history and physical examination cannot be used to limit the need of a diagnostic block. The validity of the diagnostic facet joint block should be studied, and high quality studies are required to confirm the results of single studies.

  13. 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.

    PubMed

    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

  14. History of the Standing Joint Force Headquarters for Elimination (SJFHQ-E): No More Ad Hoc

    DTIC Science & Technology

    2014-05-22

    for a Standing Joint Force Headquarters (SJFHQ) - Core Element (CE). Washington, DC: Joint Chiefs of Staff, 2008. Creswell , John W. Qualitative...reduce the threat to the United States and its allies from nuclear, biological, chemical (NBC) weapons … as well as provide research and development...that were known and available for this research project. Project 31 Due to lack of official

  15. 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.

    PubMed

    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.

  16. Genome-wide divergence, haplotype distribution and population demographic histories for Gossypium hirsutum and Gossypium barbadense as revealed by genome-anchored SNPs

    PubMed Central

    Reddy, Umesh K.; Nimmakayala, Padma; Abburi, Venkata Lakshmi; Reddy, C. V. C. M.; Saminathan, Thangasamy; Percy, Richard G.; Yu, John Z.; Frelichowski, James; Udall, Joshua A.; Page, Justin T.; Zhang, Dong; Shehzad, Tariq; Paterson, Andrew H.

    2017-01-01

    Use of 10,129 singleton SNPs of known genomic location in tetraploid cotton provided unique opportunities to characterize genome-wide diversity among 440 Gossypium hirsutum and 219 G. barbadense cultivars and landrace accessions of widespread origin. Using the SNPs distributed genome-wide, we examined genetic diversity, haplotype distribution and linkage disequilibrium patterns in the G. hirsutum and G. barbadense genomes to clarify population demographic history. Diversity and identity-by-state analyses have revealed little sharing of alleles between the two cultivated allotetraploid genomes, with a few exceptions that indicated sporadic gene flow. We found a high number of new alleles, representing increased nucleotide diversity, on chromosomes 1 and 2 in cultivated G. hirsutum as compared with low nucleotide diversity on these chromosomes in landrace G. hirsutum. In contrast, G. barbadense chromosomes showed negative Tajima’s D on several chromosomes for both cultivated and landrace types, which indicate that speciation of G. barbadense itself, might have occurred with relatively narrow genetic diversity. The presence of conserved linkage disequilibrium (LD) blocks and haplotypes between G. hirsutum and G. barbadense provides strong evidence for comparable patterns of evolution in their domestication processes. Our study illustrates the potential use of population genetic techniques to identify genomic regions for domestication. PMID:28128280

  17. Rabbit knee model of post-traumatic joint contractures: the long-term natural history of motion loss and myofibroblasts.

    PubMed

    Hildebrand, Kevin A; Sutherland, Craig; Zhang, Mei

    2004-03-01

    Our objective is to describe the natural history of motion loss with time and myofibroblast numbers in a rabbit knee model of post-traumatic joint contractures. Twenty-eight skeletally mature New Zealand White female rabbits had five-mm-squares of cortical bone removed from the medial and lateral femoral condyles of the right knee. A Kirschner wire (K-wire) was used to immobilize the knee joint in maximum flexion. A second operation was performed 8 weeks later to remove the K-wire. The rabbits were divided into four groups depending on the time of remobilization; 0, 8, 16 or 32 weeks. The average flexion contracture of the experimental knees in the 0-week and 8-week remobilization groups (38 degrees and 33 degrees, respectively) were significantly greater when compared with the values of the unoperated contralateral knees (8 degrees). The average flexion contractures of the experimental knees in the 16-week and 32-week remobilization groups were also greater than the unoperated contralateral knees, although they were not statistically significant. The average flexion contractures of the 16-week and 32-week groups were 19 degrees and 18 degrees, respectively, indicating a stabilization of the motion loss. Myofibroblast numbers in the posterior joint capsules were elevated 4-5x in the knees with contractures when compared to the contralateral knees. The initial decrease in severity followed by stabilization of motion loss and the association of motion loss with myofibroblasts mimics the human scenario of permanent post-traumatic joint contractures.

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

    PubMed Central

    2009-01-01

    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 flow patterns among An

  19. The Effect of Velocity of Joint Mobilization on Corticospinal Excitability in Individuals With a History of Ankle Sprain.

    PubMed

    Fisher, Beth E; Piraino, Andrew; Lee, Ya-Yun; Smith, Jo Armour; Johnson, Sean; Davenport, Todd E; Kulig, Kornelia

    2016-07-01

    Study Design Controlled laboratory study. Background Joint mobilization and manipulation decrease pain and improve patient function. Yet, the processes underlying these changes are not well understood. Measures of corticospinal excitability provide insight into potential mechanisms mediated by the central nervous system. Objectives To investigate the differential effects of joint mobilization and manipulation at the talocrural joint on corticospinal excitability in individuals with resolved symptoms following ankle sprain. Methods Twenty-seven participants with a history of ankle sprain were randomly assigned to the control, joint mobilization, or thrust manipulation group. The motor-evoked potential (MEP) and cortical silent period (CSP) of the tibialis anterior and gastrocnemius were obtained with transcranial magnetic stimulation at rest and during active contraction of the tibialis anterior. The slopes of MEP/CSP input/output curves and the maximal MEP/CSP values were calculated to indicate corticospinal excitability. Behavioral measures, including ankle dorsiflexion and dynamic balance, were evaluated. Results A repeated-measures analysis of variance of the MEP slope showed a significant group-by-time interaction for the tibialis anterior at rest (P = .002) and during active contraction (P = .042). After intervention, the thrust manipulation group had an increase in corticospinal excitability, while the corticospinal excitability decreased in the mobilization group. The thrust manipulation group, but not other groups, also demonstrated a significant increase in the maximal MEP amplitude of the tibialis anterior after intervention. Conclusion The findings suggest that joint manipulation and mobilization have different effects on corticospinal excitability. The increased corticospinal excitability following thrust manipulation may provide a window for physical therapists to optimize muscle recruitment and subsequently movement. The trial was registered at

  20. Molecular demographic history of the annual sunflowers Helianthus annuus and H. petiolaris--large effective population sizes and rates of long-term gene flow.

    PubMed

    Strasburg, Jared L; Rieseberg, Loren H

    2008-08-01

    Hybridization between distinct species may lead to introgression of genes across species boundaries, and this pattern can potentially persist for extended periods as long as selection at some loci or genomic regions prevents thorough mixing of gene pools. However, very few reliable estimates of long-term levels of effective migration are available between hybridizing species throughout their history. Accurate estimates of divergence dates and levels of gene flow require data from multiple unlinked loci as well as an analytical framework that can distinguish between lineage sorting and gene flow and incorporate the effects of demographic changes within each species. Here we use sequence data from 18 anonymous nuclear loci in two broadly sympatric sunflower species, Helianthus annuus and H. petiolaris, analyzed within an "isolation with migration" framework to make genome-wide estimates of the ages of these two species, long-term rates of gene flow between them, and effective population sizes and historical patterns of population growth. Our results indicate that H. annuus and H. petiolaris are approximately one million years old and have exchanged genes at a surprisingly high rate (long-term N(ef)m estimates of approximately 0.5 in each direction), with somewhat higher rates of introgression from H. annuus into H. petiolaris than vice versa. In addition, each species has undergone dramatic population expansion since divergence, and both species have among the highest levels of genetic diversity reported for flowering plants. Our results provide the most comprehensive estimate to date of long-term patterns of gene flow and historical demography in a nonmodel plant system, and they indicate that species integrity can be maintained even in the face of extensive gene flow over a prolonged period.

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

    PubMed Central

    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

  2. Genetic structure and demographic history reveal migration of the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) from the southern to northern regions of China.

    PubMed

    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.

  3. Patterns of Variation at Ustilago maydis Virulence Clusters 2A and 19A Largely Reflect the Demographic History of Its Populations

    PubMed Central

    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. PMID:24887029

  4. 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

    PubMed Central

    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

  5. [Demographic perspectives].

    PubMed

    Parant, A

    1999-01-01

    This is a brief review of possible future developments in global population trends. The author notes that the world's population will number between 8 and 11 billion by the year 2050. Topics discussed include changes in the regional balance of population, changes in the age composition of the population, and demographic aging in Europe.

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

    PubMed

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

    2014-07-01

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

  7. Conservation genetics of a rare Gerbil species: a comparison of the population genetic structures and demographic histories of the locally rare Pygmy Gerbil and the common Anderson's Gerbil

    PubMed Central

    2010-01-01

    Background One of the major challenges in evolutionary biology is identifying rare species and devising management plans to protect them while also sustaining their genetic diversity. However, in attempting a broad understanding of rarity, single-species studies provide limited insights because they do not reveal whether the factors that affect rare species differ from those that affect more common species. To illustrate this important concept and to arrive at a better understanding of the form of rarity characterizing the rare Gerbillus henleyi, we explored its population genetic structure alongside that of the locally common Gerbillus andersoni allenbyi. We trapped gerbils in several locations in Israel's western and inner Negev sand dunes. We then extracted DNA from ear samples, and amplified two mitochondrial sequences: the control region (CR) and the cytochrome oxidase 2 gene (CO2). Results Nucleotide diversity was low for all sequences, especially for the CR of G. a. allenbyi, which showed no diversity. We could not detect any significant population genetic structure in G. henleyi. In contrast, G. a. allenbyi's CO2 sequence showed significant population genetic structure. Pairwise PhiPT comparisons showed low values for G. henleyi but high values for G. a. allenbyi. Analysis of the species' demographic history indicated that G. henleyi's population size has not changed recently, and is under the influence of an ongoing bottleneck. The same analysis for G. a. allenbyi showed that this species has undergone a recent population expansion. Conclusions Comparing the two species, the populations of G. a. allenbyi are more isolated from each other, likely due to the high habitat specificity characterizing this species. The bottleneck pattern found in G. henleyi may be the result of competition with larger gerbil species. This result, together with the broad habitat use and high turnover rate characterizing G. henleyi, may explain the low level of differentiation

  8. Encounter history modeling of joint mark-recapture, tag-resighting and tag-recovery data under temporary emigration

    USGS Publications Warehouse

    Barker, R.J.; Burnham, K.P.; White, Gary C.

    2004-01-01

    We describe a joint analysis of mark-recapture, tag-resight and tag-recovery data that directly models the encounter history of an animal. The probability of the encounter history for each animal is partitioned into survival, recapture, resighting, and recovery components, and a component for the probability that the animal is never encountered again. Temporary migration enters into the likelihood through the recapture component, and movement of marked animals in and out of the area where they are subject to capture is modeled using a Markov chain. Random temporary emigration and permanent emigration are special cases. An important feature of directly modeling the encounter histories is that covariates that are specific to individuals can be included in the analysis. The model is applied to a brown trout tagging data set and provides strong evidence of Markovian temporary emigration. The new model is needed to provide correct estimates of trout survival probabilities which are shown to depend on the length of the fish at first capture.

  9. Joint Cockpit Office: history and role in defense-wide issues regarding avionics displays

    NASA Astrophysics Data System (ADS)

    O'Connor, John C.; Kraemer, William A.

    2000-08-01

    The charter of the Joint Cockpit Office (JCO) is to plan, coordinate and accelerate the transition of advanced development cockpit/crew station technologies critical to crew effectiveness in current and future air vehicles. The JCO helps assure a single, coordinated, and highly integrated cockpit/crew station Science and Technology (S&T) program within and between the Air Force, the Army, and the Navy. It serves as the primary interface and focal point for issues involving these technologies for organizations within and external to the Services. The Services are at the advent of fielding new technologies such as helmet-mounted displays as a primary flight reference. They will most certainly evaluate the use of windowless cockpits to counter the laser threat and allow for less constraining aerodynamic conditions in future vehicle design. The transition to multi-spectral displays in future military and commercial aircraft is imminent. The JCO is well positioned to assess and focus the research needed to safely exploit these new technologies and meet customer requirements. Presently, the JCO is undertaking three initiatives: creation of a joint-service, Cooperative Research and Development Agreement (CRDA) with Lockheed Martin to study the thresholds of virtual helmet-mounted display attributes and effects on pilot performance; management of the Spatial Disorientation Countermeasures program, and facilitation of the actions determined by the DoD Executive Agent for Flat Panel Displays.

  10. Joint inference of microsatellite mutation models, population history and genealogies using transdimensional Markov Chain Monte Carlo.

    PubMed

    Wu, Chieh-Hsi; Drummond, Alexei J

    2011-05-01

    We provide a framework for Bayesian coalescent inference from microsatellite data that enables inference of population history parameters averaged over microsatellite mutation models. To achieve this we first implemented a rich family of microsatellite mutation models and related components in the software package BEAST. BEAST is a powerful tool that performs Bayesian MCMC analysis on molecular data to make coalescent and evolutionary inferences. Our implementation permits the application of existing nonparametric methods to microsatellite data. The implemented microsatellite models are based on the replication slippage mechanism and focus on three properties of microsatellite mutation: length dependency of mutation rate, mutational bias toward expansion or contraction, and number of repeat units changed in a single mutation event. We develop a new model that facilitates microsatellite model averaging and Bayesian model selection by transdimensional MCMC. With Bayesian model averaging, the posterior distributions of population history parameters are integrated across a set of microsatellite models and thus account for model uncertainty. Simulated data are used to evaluate our method in terms of accuracy and precision of estimation and also identification of the true mutation model. Finally we apply our method to a red colobus monkey data set as an example.

  11. Hip joint pathology: relationship between patient history, physical tests, and arthroscopy findings in clinical practice.

    PubMed

    Tijssen, M; van Cingel, R E H; de Visser, E; Hölmich, P; Nijhuis-van der Sanden, M W G

    2017-03-01

    The purpose of this retrospective cohort study was to (a) describe the clinical presentation of femoroacetabular impingement (FAI) and hip labral pathology; (b) describe the accuracy of patient history and physical tests for FAI and labral pathology as confirmed by hip arthroscopy. Patients (18-65 years) were included if they were referred to a physical therapist to gather pre-operative data and were then diagnosed during arthroscopy. Results of pre-operative patient history and physical tests were collected and compared to arthroscopy. Data of 77 active patients (mean age: 37 years) were included. Groin as main location of pain, the Anterior Impingement test (AIT), Flexion-Abduction-External Rotation (FABER) test, and Fitzgerald test had a high sensitivity (range 0.72-0.91). Sensitivity increased when combining these tests (0.97) as either groin as main location of pain and a positive FABER test or a positive AIT and a positive FABER test were the shortest most sensitive combinations. The results of this study point out that in clinical practice absence of groin as main location of pain combined with a negative FABER test or the combination of a negative AIT and a negative FABER test are suggested to rule out the diagnosis of symptomatic FAI and/or labral pathology.

  12. The Joint Committee for Traceability in Laboratory Medicine (JCTLM) - its history and operation.

    PubMed

    Jones, Graham R D; Jackson, Craig

    2016-01-30

    The Joint Committee for Traceability in Laboratory Medicine (JCTLM) was formed to bring together the sciences of metrology, laboratory medicine and laboratory quality management. The aim of this collaboration is to support worldwide comparability and equivalence of measurement results in clinical laboratories for the purpose of improving healthcare. The JCTLM has its origins in the activities of international metrology treaty organizations, professional societies and federations devoted to improving measurement quality in physical, chemical and medical sciences. The three founding organizations, the International Committee for Weights and Measures (CIPM), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC) and the International Laboratory Accreditation Cooperation (ILAC) are the leaders of this activity. The main service of the JCTLM is a web-based database with a list of reference materials, reference methods and reference measurement services meeting appropriate international standards. This database allows manufacturers to select references for assay traceability and provides support for suppliers of these services. As of mid 2015 the database lists 295 reference materials for 162 analytes, 170 reference measurement procedures for 79 analytes and 130 reference measurement services for 39 analytes. There remains a need for the development and implementation of metrological traceability in many areas of laboratory medicine and the JCTLM will continue to promote these activities into the future.

  13. Dounreay PFR irradiation history for the joint US/UK actinide sample exposures

    SciTech Connect

    Raman, S.; Murphy, B.D.; Nestor, C.W. Jr.

    1995-07-01

    The operating history of the Dounreay Prototype Fast Reactor is presented to the extent that it is relevant to the irradiation of actinide specimens that were subsequently analyzed at Oak Ridge National Laboratory (ORNL). Three fuel pins with actinide samples were irradiated from July 1982 to July 1988 and returned to ORNL for analysis. They contained isotopes of elements from thorium to curium. The times when each of these fuel pins were in the reactor core are described as are the operating power levels and neutron spectra. The appendices give daily power levels of the reactor as well as six-group neutron energy spectra for various times and axial positions in the core.

  14. Look before You Leap: Underestimating Chinese Student History, Chinese University Setting and Chinese University Steering in Sino-British HE Joint Ventures?

    ERIC Educational Resources Information Center

    Dow, Ewan G.

    2010-01-01

    This article makes the case--in three parts--that many Anglo-Chinese university collaborations (joint ventures) to date have seriously underestimated Chinese (student) history, the Chinese university setting and Chinese national governmental steering as part of the process of "glocalisation". Recent turbulence in this particular HE…

  15. A joint history of the nature of genetic variation and the nature of schizophrenia.

    PubMed

    Kendler, K S

    2015-02-01

    This essay traces the history of concepts of genetic variation and schizophrenia from Darwin and Mendel to the present. For Darwin, the important form of genetic variation for evolution is continuous in nature and small in effect. Biometricians led by Pearson agreed and developed statistical genetic approaches utilizing trait correlations in relatives. Mendel studied discontinuous traits and subsequent Mendelians, led by Bateson, assumed that important genetic variation was large in effect producing discontinuous phenotypes. Although biometricians studied 'insanity', schizophrenia genetics under Kraepelin and Rüdin utilized Mendelian approaches congruent with their anatomical-clinical disease model of dementia praecox. Fisher showed, assuming many genes of small effect, Mendelian and Biometrical models were consilient. Echoing prior conflicts, psychiatric genetics since then has utilized both biometrical models, largely in twins, and Mendelian models, based on advancing molecular techniques. In 1968, Gottesman proposed a polygenic model for schizophrenia based on a threshold version of Fisher's theory. Since then, rigorous studies of the schizophrenia spectrum suggest that genetic risk for schizophrenia is more likely continuous than categorical. The last 5 years has seen increasingly convincing evidence from genome-wide association study (GWAS) and sequencing that genetic risk for schizophrenia is largely polygenic, and congruent with Fisher's and Gottesman's models. The gap between biometrical and molecular Mendelian models for schizophrenia has largely closed. The efforts to ground a categorical biomedical model of schizophrenia in Mendelian genetics have failed. The genetic risk for schizophrenia is widely distributed in human populations so that we all carry some degree of risk.

  16. A joint history of the nature of genetic variation and the nature of schizophrenia

    PubMed Central

    Kendler, KS

    2014-01-01

    This essay traces the history of concepts of genetic variation and schizophrenia from Darwin and Mendel to the present. For Darwin, the important form of genetic variation for evolution is continuous in nature and small in effect. Biometricians led by Pearson agreed and developed statistical genetic approaches utilizing trait correlations in relatives. Mendel studied discontinuous traits and subsequent Mendelians, led by Bateson, assumed that important genetic variation was large in effect producing discontinuous phenotypes. Although biometricians studied ‘insanity’, schizophrenia genetics under Kraepelin and Rüdin utilized Mendelian approaches congruent with their anatomical-clinical disease model of dementia praecox. Fisher showed, assuming many genes of small effect, Mendelian and Biometrical models were consilient. Echoing prior conflicts, psychiatric genetics since then has utilized both biometrical models, largely in twins, and Mendelian models, based on advancing molecular techniques. In 1968, Gottesman proposed a polygenic model for schizophrenia based on a threshold version of Fisher’s theory. Since then, rigorous studies of the schizophrenia spectrum suggest that genetic risk for schizophrenia is more likely continuous than categorical. The last 5 years has seen increasingly convincing evidence from genome-wide association study (GWAS) and sequencing that genetic risk for schizophrenia is largely polygenic, and congruent with Fisher’s and Gottesman’s models. The gap between biometrical and molecular Mendelian models for schizophrenia has largely closed. The efforts to ground a categorical biomedical model of schizophrenia in Mendelian genetics have failed. The genetic risk for schizophrenia is widely distributed in human populations so that we all carry some degree of risk. …Variations, as Darwin and most breeders recognized, were of two types. There were sports, large discontinuous variations, relatively rare … [and] there were the less

  17. History of the Joint Chiefs of Staff. The Joint Chiefs of Staff and the War in Vietnam, 1960-1968. Part 2

    DTIC Science & Technology

    2012-01-01

    eight targets dropped, the staff substituted a group of facilities in the Haiphong/Hon Gay port areas. "If there is a substantial fall out of targets...strike nine fixed targets, none of them particularly valuable. The program did not include the Haiphong/Hon Gay targets.28 In late August, the Joint...military aspects of the issue, the Joint Chiefs recommended the addition of aerial mining of the approaches to Haiphong, Hon Gay , and Cam Pha to the

  18. Not all non-drinkers with HIV are equal: demographic and clinical comparisons among current non-drinkers with and without a history of prior alcohol use disorders.

    PubMed

    Crane, Heidi M; Nance, Robin M; Merrill, Joseph O; Hutton, Heidi; Chander, Geetanjali; McCaul, Mary E; Mathews, W Chris; Fredericksen, Rob; Simoni, Jane M; Mayer, Kenneth; Mugavero, Michael J; Willig, James H; Burkholder, Greer; Drozd, Daniel R; Mimiaga, Matthew; Lau, Bryan; Kim, H Nina; Cropsey, Karen; Moore, Richard D; Christopoulos, Katerina; Geng, Elvin; Eron, Joseph J; Napravnik, Sonia; Kitahata, Mari M; Saag, Michael S; Delaney, Joseph Ac

    2017-02-01

    Studies of persons living with HIV (PLWH) have compared current non-drinkers to at-risk drinkers without differentiating whether current non-drinkers had a prior alcohol use disorder (AUD). The purpose of this study was to compare current non-drinkers with and without a prior AUD on demographic and clinical characteristics to understand the impact of combining them. We included data from six sites across the US from 1/2013 to 3/2015. Patients completed tablet-based clinical assessments at routine clinic appointments using the most recent assessment. Current non-drinkers were identified by AUDIT-C scores of 0. We identified a prior probable AUD by a prior AUD diagnosis in the electronic medical record (EMR) or a report of attendance at alcohol treatment in the clinical assessment. We used multivariate logistic regression to examine factors associated with prior AUD. Among 2235 PLWH who were current non-drinkers, 36% had a prior AUD with more patients with an AUD identified by the clinical assessment than the EMR. Higher proportions with a prior AUD were male, depressed, and reported current drug use compared to non-drinkers without a prior AUD. Former cocaine/crack (70% vs. 25%), methamphetamine/crystal (49% vs. 16%), and opioid/heroin use (35% vs. 7%) were more commonly reported by those with a prior AUD. In adjusted analyses, male sex, past methamphetamine/crystal use, past marijuana use, past opioid/heroin use, past and current cocaine/crack use, and cigarette use were associated with a prior AUD. In conclusion, this study found that among non-drinking PLWH in routine clinical care, 36% had a prior AUD. We found key differences between those with and without prior AUD in demographic and clinical characteristics, including drug use and depression. These results suggest that non-drinkers are heterogeneous and need further differentiation in studies and that prior alcohol misuse (including alcohol treatment) should be included in behavioural health assessments as

  19. Whole-genome sequencing reveals absence of recent gene flow and separate demographic histories for Anopheles punctulatus mosquitoes in Papua New Guinea

    PubMed Central

    LOGUE, KYLE; SMALL, SCOTT T.; CHAN, ERNEST R.; REIMER, LISA; SIBA, PETER M.; ZIMMERMAN, PETER A.; SERRE, DAVID

    2015-01-01

    Anopheles mosquitoes are the vectors of several human diseases including malaria. In many malaria endemic areas, several species of Anopheles coexist, sometimes in the form of related sibling species that are morphologically indistinguishable. Determining the size and organization of Anopheles populations, and possible ongoing gene flow among them is important for malaria control and, in particular, for monitoring the spread of insecticide resistance alleles. However, these parameters have been difficult to evaluate in most Anopheles species due to the paucity of genetic data available. Here, we assess the extent of contemporary gene flow and historical variations in population size by sequencing and de novo assembling the genomes of wild-caught mosquitoes from four species of the Anopheles punctulatus group of Papua New Guinea. Our analysis of more than 50 Mb of orthologous DNA sequences revealed no evidence of contemporary gene flow among these mosquitoes. In addition, investigation of the demography of two of the An. punctulatus species revealed distinct population histories. Overall, our analyses suggest that, despite their similarities in morphology, behaviour and ecology, contemporary sympatric populations of An. punctulatus are evolving independently. PMID:25677924

  20. The Joint Chiefs of Staff and the War in Vietnam, 1960-1968. Part 3: History of the Joint Chiefs of Staff

    DTIC Science & Technology

    2009-01-01

    ports of Cam Pha and Hon Gai , and the eight major operational airfields, only three of which were currently authorized for attack. The Joint Chiefs...authorized air strikes against the minor ports of Cam Pha and Hon Gai . They were to be bombed only when ships were at least 2,000 yards from the docks...until North Vietnam, as a result of attacks against the Haiphong port, began using Cam 71) JCS and the War in Vietnam, 1960-1968 Pha and Hon Gai for

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2015-03-01

    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.

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

    PubMed Central

    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

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

    PubMed

    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. 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

    PubMed Central

    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

  7. History of the Balkans: Twentieth Century. Volume 2. The Joint Committee on Eastern Europe Publication Series. No. 12.

    ERIC Educational Resources Information Center

    Jelavich, Barbara

    Principal issues in the 20th century development of the Balkan Peninsula are discussed in this introductory history text. Three themes--national rivalries, great power interference, and the economic, social, and political problems of modernization--are given special emphasis. An overview of 18th and 19th century history precedes the two major…

  8. [An inveterate fracture of the barton type of the distal radius with dislocation in the radiocarpal joint--case history].

    PubMed

    Bednarenko, Marcin; Kotela, Ireneusz; Bołtuć, Witold; Jakubowski, Lukasz

    2006-01-01

    Barton's fracture was first described and isolated as a disease entity in 1839. It is a quite rare fracture constituting, according to various authors 1.5-2.3% of the distal radius fractures. It is usually accompanied with subluxation or luxation in the radiocarpal joint. In the study we present treatment, dealing with operative difficulties and rehabilitation in a 52-year-old patient with an inveterate fracture of the Barton type of the distal radius with dislocation in the radiocarpal joint. He was previously treated by a local quack. The patient underwent an operative treatment; fragments were anatomically repositioned and a stable fixation was applied. As a result of treatment and intensive rehabilitation, we achieved synostosis and functionality of the wrist and left hand.

  9. History of the Balkans: Eighteenth and Nineteenth Centuries. Volume 1. The Joint Committee on Eastern Europe Publications Series. No. 12.

    ERIC Educational Resources Information Center

    Jelavich, Barbara

    Designed as an introductory history, this book covers developments in the Balkan Peninsula from the 17th through the 19th centuries. Emphasis is placed on the process by which separate nationalities broke away from imperial rule, established independent states, and embarked on economic and social modernization. To establish perspective on the role…

  10. Human Resources & Demographics: Characteristics of People and Policy.

    ERIC Educational Resources Information Center

    Joint Economic Committee, Washington, DC.

    The Human Resources and Demographics staff study for the Joint Economic Committee's Special Study on Economic Change presents demographic data to support the position that it will take a strong economy to enable the United States to utilize its human resources. Data are presented, in narrative format, on fertility, population, characteristics of…

  11. Evolutionary shaping of demographic schedules

    PubMed Central

    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

  12. Re-writing the natural history of pain and related symptoms in the joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.

    PubMed

    Castori, Marco; Morlino, Silvia; Celletti, Claudia; Ghibellini, Giulia; Bruschini, Michela; Grammatico, Paola; Blundo, Carlo; Camerota, Filippo

    2013-12-01

    Joint hypermobility syndrome (JHS) and Ehlers-Danlos syndrome, hypermobility type (EDS-HT) are two clinically overlapping connective tissue disorders characterized by chronic/recurrent pain, joint instability complications, and minor skin changes. Fatigue and headache are also common, although are not yet considered diagnostic criteria. JHS/EDS-HT is a unexpectedly common condition that remains underdiagnosed by most clinicians and pain specialists. This results in interventions limited to symptomatic and non-satisfactory treatments, lacking reasonable pathophysiologic rationale. In this manuscript the fragmented knowledge on pain, fatigue, and headache in JHS/EDS is presented with review of the available published information and a description of the clinical course by symptoms, on the basis of authors' experience. Pathogenic mechanisms are suggested through comparisons with other functional somatic syndromes (e.g., chronic fatigue syndrome, fibromyalgia, and functional gastrointestinal disorders). The re-writing of the natural history of JHS/EDS-HT is aimed to raise awareness among clinical geneticists and specialists treating chronic pain conditions about pain and other complications of JHS/EDS-HT. Symptoms' clustering by disease stage is proposed to investigate both the molecular causes and the symptoms management of JHS/EDS-HT in future studies.

  13. Dancing with Demographers.

    ERIC Educational Resources Information Center

    Robertson, Heather-Jane

    2000-01-01

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

  14. Demographics: People and Markets.

    ERIC Educational Resources Information Center

    Merrick, Thomas W.; Tordella, Stephen J.

    1988-01-01

    Population shifts directly affect the bottom line, so the basics of demography are now basic to business as well. Demographics combine demographic data with socioeconomic and geographic factors to help business and other managers know the market for the goods and services they offer. This guide explains market, product, and site analyses,…

  15. Bayesian Analysis of Evolutionary Divergence with Genomic Data Under Diverse Demographic Models.

    PubMed

    Chung, Yujin; Hey, Jody

    2017-02-25

    We present a new Bayesian method for estimating demographic and phylogenetic history using population genomic data. Several key innovations are introduced that allow the study of diverse models within an Isolation with Migration framework. The new method implements a 2-step analysis, with an initial Markov chain Monte Carlo (MCMC) phase that samples simple coalescent trees, followed by the calculation of the joint posterior density for the parameters of a demographic model. In step 1, the MCMC sampling phase, the method uses a reduced state space, consisting of coalescent trees without migration paths, and a simple importance sampling distribution without the demography of interest. Once obtained, a single sample of trees can be used in step 2 to calculate the joint posterior density for model parameters under multiple diverse demographic models, without having to repeat MCMC runs. Because migration paths are not included in the state space of the MCMC phase, but rather are handled by analytic integration in step 2 of the analysis, the method is scalable to a large number of loci with excellent MCMC mixing properties. With an implementation of the new method in the computer program MIST, we demonstrate the method's accuracy, scalability and other advantages using simulated data and DNA sequences of two common chimpanzee subspecies: Pan troglodytes troglodytes (P. t.) and P. t. verus.

  16. Genetic demographic networks: Mathematical model and applications.

    PubMed

    Kimmel, Marek; Wojdyła, Tomasz

    2016-10-01

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

  17. Demographic changes and nationalism.

    PubMed

    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.

  18. Reassessing the Demographic Imperative

    ERIC Educational Resources Information Center

    Folts, W. Edward; Rosenberg, Edwin; Muir, Kenneth B.; Baumhover, Lorin A.

    2005-01-01

    For many years gerontologists have discussed the consequences of advances that have lengthened lives but have been less successful at improving the quality of those lives. While this debate continues, the resulting demographic shift in the age profile of the United States threatens to overwhelm our ability to care for those who most need…

  19. The Demographic Imperative

    ERIC Educational Resources Information Center

    Jordan, Stephen M.

    2009-01-01

    As the United States moves toward becoming a "minority-majority" country, what more can--and should--college presidents and governing boards do to provide low-income students and students of color with a pipeline to high-quality education? Ongoing discourse about shifting demographics locally and nationally must be built into…

  20. Changing Hispanic Demographics.

    ERIC Educational Resources Information Center

    McKay, Emily Gantz

    This report provides a demographic overview of Hispanics in the United States. Information was drawn largely from recent census figures. The following highlights are reported: (1) Hispanic Americans are the youngest and fastest growing minority group, but they are also more likely than non-Hispanics to drop out of school, be unemployed or…

  1. Youth Demographics. Fact Sheet

    ERIC Educational Resources Information Center

    Lopez, Mark Hugo; Marcelo, Karlo Barrios

    2006-01-01

    This fact sheet compares the numbers of 18-25 year-old residents and citizens by gender, race, ethnicity, geographic distribution, marital status, military status, unemployment, educational attainment, and assesses population trends from 1968-2006. It explores such demographic characteristics of young people using data from the March Annual…

  2. Joint swelling

    MedlinePlus

    Swelling of a joint ... Joint swelling may occur along with joint pain . The swelling may cause the joint to appear larger or abnormally shaped. Joint swelling can cause pain or stiffness. After an ...

  3. KSC History Project

    NASA Technical Reports Server (NTRS)

    Dethloff, Henry C.

    2001-01-01

    The KSC History Project focuses on archival research and oral history interviews on the history of Kennedy Space Center (KSC). Related projects include the preparation of a precis and chapter outline for a proposed book-length narrative history, a bibliography of key primary and secondary resources, a brief monograph overview of the history of KSC, and a monograph on the history of safety at the Center. Finally, there is work on the development of a web page and a personal history data base associated with the oral history project. The KSC History Project has been a joint endeavor between Henry C. Dethloff and Dr. Noble Lee Snaples, Jr.

  4. [Reforms and demographic crisis].

    PubMed

    Velichkovskiĭ, B T

    2002-01-01

    During reformation years all basic medical and demographic indices have undergone negative changes in Russia. Since 1992 there has been a steady-state decrease in the population due to the fact that mortality rates are extremely greater than birth ones. In 2001, the Russian population reduced in number by nearly a million. The birth rates are twice less than that requires for a simple reproduction of generations. Extremely high death rates remain among the population, in able-bodied males. The main reasons for the demographic crisis are the negative consequences of the implemented reforms rather than the transition from traditional to the new present-day reproduction of the population. It is problematic now to correct the situation via active migration of Russian-speaking persons. This requires enormous funds to provide comers with jobs and dwelling. It is unreal to diminish annual departure of 100 thousand persons, mainly young educated professionals from the country, though it is joust not only a demographic, but a strategic problem. In 2001 there was a some rise in birth rates. But this is the most illusive way of solving the demographic crisis. Just in the USSR, the high educational level of the population, the socioeconomic emancipation of females and progress in medicine gave rise to the transition to the present-day reproduction of the population, which is characterized by low birth and death rates. So the population is unlikely to be replenished by high birth rates. The main way of overcoming the demographic crisis is to reduce mortality and not to allow young people to die prematurely. For this it is necessary to know the biological mechanisms responsible for extremely high mortality. It is most likely to be due to breakdown in the dynamic stereotype of higher nervous performance, as stated by I. P. Pavlov. Today it is insufficient to control alcoholism, traumatism, and smoking by healthy lifestyle propaganda in order to reduce death rates in Russian. All

  5. Asians in New York City: A Demographic Summary.

    ERIC Educational Resources Information Center

    Steingasser, Jean; And Others

    This demographic survey provides the following information on Asian Americans: (1) states with the highest Asian American population; (2) ethnic breakdown among Asians; (3) Asian immigration history and legislation affecting it; (4) individual immigration histories of Asian Americans in New York City (New York), including the Chinese, Japanese,…

  6. Examining the knee joint.

    PubMed

    Monk, Daniel

    2013-04-01

    Appropriate history taking and examination can ensure accurate diagnosis of common knee problems, and rapid and effective interventions or referral to orthopaedic specialists. This article describes the anatomy of the knee joint and discusses relevant history taking, the examination process, special tests and radiology, as well as common knee injuries and their management.

  7. Building demographic literacy.

    PubMed

    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.

  8. Stochastic demographic forecasting.

    PubMed

    Lee, R D

    1992-11-01

    "This paper describes a particular approach to stochastic population forecasting, which is implemented for the U.S.A. through 2065. Statistical time series methods are combined with demographic models to produce plausible long run forecasts of vital rates, with probability distributions. The resulting mortality forecasts imply gains in future life expectancy that are roughly twice as large as those forecast by the Office of the Social Security Actuary.... Resulting stochastic forecasts of the elderly population, elderly dependency ratios, and payroll tax rates for health, education and pensions are presented."

  9. Demographic Trends in Social Work over a Quarter-Century in an Increasingly Female Profession

    ERIC Educational Resources Information Center

    Schilling, Robert; Morrish, Jennifer Naranjo; Liu, Gan

    2008-01-01

    This article depicts the changing demographic portrait of social work education in the United States from 1974 through 2000 and considers the demographic shifts in the profession of social work. During this period, BSW and joint MSW-BSW programs increased from 150 to 404, MSW programs increased from 79 to 139, and social work doctoral programs…

  10. China's demographic dilemma.

    PubMed

    1994-01-01

    China's population policies should take into account that further population declines between 1992 and the year 2000 will result in reducing the proportion of young people and increasing by two times the number of elderly over the age of 65 years. The aged population which was 1.2 billion in 1994 is expected to increase to 12.9% of total population. The expected increases in the elderly would make China the only country in the world, beside Japan with an expected elderly population comprising 20% of total population by 2025, ever to have such a high proportion of aged. China must decide whether it is more important to reduce population growth or secure a favorable ratio of working age persons to elderly dependents. With a high proportion of elderly in a population, there would be a need for social support from children for the elderly and increased expenditures for pensions, public health services, social welfare, and social relief. Griffith Feeney and Yuan Jianhua of the Beijing Institute of Information and Control in 1994 examined data from a 1992 national survey and found that fertility declined from 2.04 children per woman in 1990 to 1.65 children per woman in 1991, which is replacement level fertility. The reliability of the survey results has been questioned by Chinese demographers because of the change in national birth planning policy to the responsibility system among local, regional, and national political and administrative heads for family planning use. The study researchers conclude that, even with underreporting of 10% to 20%, the survey results indicate attainment of Chinese replacement level fertility. If policy continues to press for fertility decline, there would be unprecedented number of elderly and a tremendous population imbalance. Demographically, this form of age structure imbalance has never been experienced historically. The 1992 State Family Planning Commission survey results were substantiated by surveys conducted between 1982 and 1990

  11. KSC History Project

    NASA Technical Reports Server (NTRS)

    Snaples, Lee

    2001-01-01

    The project is a joint endeavor between Dr. Henry Dethloff and myself and is producing a number of products related to KSC history. This report is a summary of those projects. First, there is an overview monograph covering KSC history. Second, there is a chapter outline for an eventual book-length history. Third, there is monograph on safety at KSC. Finally, there is a web page and database dedicated to the KSC oral history project.

  12. Planet Demographics from Transits

    NASA Astrophysics Data System (ADS)

    Howard, Andrew

    2015-08-01

    From the demographics of planets detected by the Kepler mission, we have learned that there exists approximately one planet per star for planets larger than Earth orbiting inside of 1 AU. We have also learned the relative occurrence of these planets as a function of their orbital periods, sizes, and host star masses and metallicities. In this talk I will review the key statistical findings that the planet size distribution peaks in the range 1-3 times Earth-size, the orbital period distribution is characterized by a power-law cut off at short periods, small planets are more prevalent around small stars, and that approximately 20% of Sun-like stars hosts a planet 1-2 times Earth-size in a habitable zone. Looking forward, I will describe analysis of photometry from the K2 mission that is yielding initial planet discoveries and offering the opportunity to measure planet occurrence in widely separated regions of the galaxy. Finally, I will also discuss recent techniques to discover transiting planets in space-based photometry and to infer planet population properties from the ensemble of detected and non-detected transit signals.

  13. Relations between demographic parameters.

    PubMed

    Demetrius, L

    1979-05-01

    The mean life-expectancy e describes the average prospective life-time of an individual aged zero. This parameter can be explicitly described in terms of the survivorship distribution of the population. The Malthusian parameter r represents the asymptotic growth rate of a population. This parameter can be implicitly expressed in terms of the net-maternity distribution. The parameters e and r incompletely incorporate the age-specific fertility and mortality pattern of a population; distinct populations may have the same growth rate but different net-maternity functions; distinct populations may be characterized by the same mean life expectation but may have different survivorship distributions. This article analyzes a class of parameters called the entropy of a population (Demetrius, 1974a) which distinguishes between net-maternity functions with the same growth rate and also mortality distributions with the same mean life expectation. This class of parameters measures the convexity of the fertility and mortality distributions. This paper analyzes the relations between the entropy parameter and the standard demographic parameters.

  14. Demographics of Planetary Science

    NASA Astrophysics Data System (ADS)

    Bagenal, F.; White, S.

    2011-10-01

    A survey was sent out to university departments around the US that were thought to include faculty involved in planetary science research and/or offer planetary science undergraduate or graduate degrees. This is Part A of a study of the demographics of planetary science carried out by the American Institute of Physics (AIP) and sponsored by NASA's Planetary Science Division. Part B will be a survey of the planetary scientists with PhDs working in the US, to be carried out by the AIP in mid-2011. Starting on December 8th 2010 surveys were sent out by email to department chairs. A total of 48 departments responded between December 9th and April 8th . There is only U of Arizona that has a department that is called planetary sciences - the rest are combined with Earth sciences (14), astronomy (15), geology/geophysics (8), physics (7), atmospheric science (5), something else or combinations thereof. We present statistics from these 48 departments on faculty, researchers, graduate and undergraduate students.

  15. Demographic Trends: Impact on Schools

    ERIC Educational Resources Information Center

    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. 38 CFR 4.66 - Sacroiliac joint.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... permit assumption of pure traumatic origin, objective evidence of damage to the joint, and history of... paralysis attributable to disease affecting the lumbar vertebrae and the intervertebral disc....

  17. Tidal disruption event demographics

    NASA Astrophysics Data System (ADS)

    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 < 10-1 yr (37 d), and 84 per cent having longer time-scales. Many residual rate discrepancies can be explained if surveys are biased against TDEs with these longer tfb, which seems very 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.

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

    PubMed

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

    2014-09-01

    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.

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

    USGS Publications Warehouse

    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.

  20. [Diagnosis. History and physical examination].

    PubMed

    Pérez Martín, Álvaro

    2014-01-01

    Family physicians play a key role in the diagnosis and management of patients with osteoarthritis. Diagnosis is mainly clinical and radiological. A complete history should be taken with meticulous physical examination of the joints. The history-taking should aim to detect risk factors and compatible clinical symptoms. Pain characteristics should be identified, distinguishing between mechanical and inflammatory pain, and an exhaustive examination of the joints should be performed, with evaluation of the presence of pain, deformity, mobility restrictions (both active and passive), crepitus, joint effusion, and inflammation. A differential diagnosis should be made with all diseases that affect the joints and/or produce joint stiffness.

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

    ERIC Educational Resources Information Center

    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…

  2. [Contemporary demographic survey of Venezuela].

    PubMed

    Osorio, E

    1985-01-01

    Current demographic trends in Venezuela are reviewed, based on data from the 1981 census. Topics covered include population growth, age structure, family characteristics, school-age population, foreign population, spatial distribution, labor force, and housing.

  3. Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint.

    PubMed

    Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

    2014-01-01

    Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement.

  4. Utility of Intraoperative Neuromonitoring during Minimally Invasive Fusion of the Sacroiliac Joint

    PubMed Central

    Woods, Michael; Birkholz, Denise; MacBarb, Regina; Capobianco, Robyn; Woods, Adam

    2014-01-01

    Study Design. Retrospective case series. Objective. To document the clinical utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion for patients diagnosed with sacroiliac joint dysfunction (as a direct result of sacroiliac joint disruptions or degenerative sacroiliitis) and determine stimulated electromyography thresholds reflective of favorable implant position. Summary of Background Data. Intraoperative neuromonitoring is a well-accepted adjunct to minimally invasive pedicle screw placement. The utility of intraoperative neuromonitoring during minimally invasive surgical sacroiliac joint fusion using a series of triangular, titanium porous plasma coated implants has not been evaluated. Methods. A medical chart review of consecutive patients treated with minimally invasive surgical sacroiliac joint fusion was undertaken at a single center. Baseline patient demographics and medical history, intraoperative electromyography thresholds, and perioperative adverse events were collected after obtaining IRB approval. Results. 111 implants were placed in 37 patients. Sensitivity of EMG was 80% and specificity was 97%. Intraoperative neuromonitoring potentially avoided neurologic sequelae as a result of improper positioning in 7% of implants. Conclusions. The results of this study suggest that intraoperative neuromonitoring may be a useful adjunct to minimally invasive surgical sacroiliac joint fusion in avoiding nerve injury during implant placement. PMID:25544898

  5. Joint pain

    MedlinePlus

    ... that may be done include: CBC or blood differential C-reactive protein Joint x-ray Sedimentation rate ... chap 256. Schaible H-G. Joint pain: basic mechanisms. In: McMahon SB, Koltzenburg M, Tracey I, Turk ...

  6. Joint Interdiction

    DTIC Science & Technology

    2016-09-09

    Purpose This publication has been prepared under the direction of the Chairman of the Joint Chiefs of Staff. It sets forth joint doctrine to govern the...governmental and nongovernmental organizations, multinational forces, and other interorganizational partners. It provides military guidance for the...exercise of authority by combatant commanders and other joint force commanders (JFCs), and prescribes joint doctrine for operations and training. It

  7. Joint Disorders

    MedlinePlus

    A joint is where two or more bones come together, like the knee, hip, elbow, or shoulder. Joints can be damaged by many types of injuries or diseases, including Arthritis - inflammation of a joint. It causes pain, stiffness, and swelling. Over time, ...

  8. Social demographic change and autism.

    PubMed

    Liu, Kayuet; Zerubavel, Noam; Bearman, Peter

    2010-05-01

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

  9. Social Demographic Change and Autism

    PubMed Central

    LIU, KAYUET; ZERUBAVEL, NOAM; BEARMAN, PETER

    2010-01-01

    Parental age at child’s birth—which has increased for U.S. children in the 1992–2000 birth cohorts—is strongly associated with an increased risk of autism. By turning a social demographic lens on the historical patterning of concordance among twin pairs, we identify a central mechanism for this association: de novo mutations, which are deletions, insertions, and duplications of DNA in the germ cells that are not present in the parents’ DNA. Along the way, we show that a demographic eye on the rising prevalence of autism leads to three major discoveries. First, the estimated heritability of autism has been dramatically overstated. Second, heritability estimates can change over remarkably short periods of time because of increases in germ cell mutations. Third, social demographic change can yield genetic changes that, at the population level, combine to contribute to the increased prevalence of autism. PMID:20608100

  10. Incidence and Demographics of Childhood Ptosis

    PubMed Central

    Griepentrog, Gregory J.; Diehl, Nancy; Mohney, Brian G.

    2012-01-01

    Purpose To report the incidence and demographics of childhood ptosis diagnosed over a 40-year period in a well-defined population. Design Retrospective, population-based cohort study. Participants Patients (< 19 years) diagnosed with childhood ptosis as residents of Olmsted County, Minnesota, from January 1, 1965, through December 31, 2004 Methods The medical records of all potential patients identified by the Rochester Epidemiology Project were reviewed. Main Outcome Measures Calculated annual age- and sex-specific incidence rates and demographic information. Results A total of 107 children were diagnosed with ptosis during the 40-year period, yielding an incidence of 7.9/100,000 < 19 years (95% confidence interval [CI]: 6.4-9.5) of age. Ninety-six (89.7%) of the 107 were congenital in onset, 81 (75%) of which had simple congenital ptosis, yielding a birth prevalence of 1 in 842 births. A family history of childhood ptosis was present in twelve percent of queried patients with simple congenital ptosis. Three (4%) of the simple congenital ptosis cases were bilateral and 55 (68%) of the unilateral cases involved the left upper eyelid (95% CI: 57%-78%, p<0.001). Conclusion Childhood ptosis was diagnosed in 7.9 per 100,000 patients less than 19 years (95% CI: 6.4-9.5). Simple congenital ptosis was the most prevalent form, occurring in 1 in 842 births, and significantly more likely to involve the left side. PMID:21496927

  11. Uncovering the hidden demographic history of the USSR.

    PubMed

    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.

  12. Grandparents today: a demographic profile.

    PubMed

    Szinovacz, M E

    1998-02-01

    This article presents a demographic profile of grandparents, using the National Survey of Families and Households. Specific dimensions of grandparenthood addressed include grandparents' survival, the timing of grandparenthood, grandparents' involvement in other roles, surrogate parenting, and stepgrandparents. The data indicate considerable heterogeneity among grandparents of different genders and races or ethnicities. They also suggest modifications in previous descriptions of modern grandparenthood.

  13. Grandparents Today: A Demographic Profile.

    ERIC Educational Resources Information Center

    Szinovacz, Maximiliane E.

    1998-01-01

    Utilizes the National Survey of Families and Households to present a demographic profile of grandparents. Examines grandparents' survival, timing of grandparenthood, grandparents' involvement in other roles, surrogate parenting, and stepgrandparents. Data indicate considerable heterogeneity among grandparents of different genders and ethnicities.…

  14. Demographic Modelling in Weed Biocontrol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    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...

  15. Enrollment Management: Demographic Changes. Report.

    ERIC Educational Resources Information Center

    Gribbons, Barry C.; Meuschke, Daylene M.

    The Office of Institutional Development and Technology and the Public Information Office created this report that identifies several topics of research in order to inform marketing efforts associated with enrollment management. The report is based upon demographic studies done at the College of Canyons to measure things such as changes in the size…

  16. Are Demographics the Nation's Destiny?

    ERIC Educational Resources Information Center

    Glass, Gene V.

    2008-01-01

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

  17. Demographic Factors Affecting Faculty Salary.

    ERIC Educational Resources Information Center

    Webster, Allen L.

    1995-01-01

    Specific demographic attributes that influence salary at institutions of higher education were studied through data from 420 faculty members at 9 institutions. Results suggested that experience, publication rates, time at the institution, and possession of a terminal degree affected salary levels. The presence of salary compression was noted. (SLD)

  18. Democratic constraints on demographic policy.

    PubMed

    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

  19. Memory specificity and mindfulness jointly moderate the effect of reflective pondering on depressive symptoms in individuals with a history of recurrent depression.

    PubMed

    Brennan, Kate; Barnhofer, Thorsten; Crane, Catherine; Duggan, Danielle; Williams, J Mark G

    2015-05-01

    In previously depressed individuals, reflective thinking may easily get derailed and lead to detrimental effects. This study investigated the conditions in which such thinking is, or is not, adaptive. Levels of mindfulness and autobiographical memory specificity were assessed as potential moderators of the relationship between reflective thinking and depressive symptoms. Two hundred seventy-four individuals with a history of three or more previous episodes of depression completed self-report measures of depressive symptoms, rumination-including subscales for reflection and brooding-and mindfulness, as well as an autobiographical memory task to assess memory specificity. In those low in both mindfulness and memory specificity, higher levels of reflection were related to more depressive symptoms, whereas in all other groups higher levels of reflection were related to fewer depressive symptoms. The results demonstrate that the relation between reflective pondering and depressive symptoms varies depending on individual state or trait factors. In previously depressed individuals, the cognitive problem-solving aspect of reflection may be easily hampered when tendencies toward unspecific processing are increased, and awareness of mental processes such as self-judgment and reactivity is decreased.

  20. Rupture history of the 2008 Mw 7.9 Wenchuan, China, earthquake: Evaluation of separate and joint inversions of geodetic, teleseismic, and strong-motion data

    USGS Publications Warehouse

    Hartzell, Stephen; Mendoza, Carlos; Ramírez-Guzmán, Leonardo; Zeng, Yuesha; Mooney, Walter

    2013-01-01

    An extensive data set of teleseismic and strong-motion waveforms and geodetic offsets is used to study the rupture history of the 2008 Wenchuan, China, earthquake. A linear multiple-time-window approach is used to parameterize the rupture. Because of the complexity of the Wenchuan faulting, three separate planes are used to represent the rupturing surfaces. This earthquake clearly demonstrates the strengths and limitations of geodetic, teleseismic, and strong-motion data sets. Geodetic data (static offsets) are valuable for determining the distribution of shallower slip but are insensitive to deeper faulting and reveal nothing about the timing of slip. Teleseismic data in the distance range 30°–90° generally involve no modeling difficulties because of simple ray paths and can distinguish shallow from deep slip. Teleseismic data, however, cannot distinguish between different slip scenarios when multiple fault planes are involved because steep takeoff angles lead to ambiguity in timing. Local strong-motion data, on the other hand, are ideal for determining the direction of rupture from directivity but can easily be over modeled with inaccurate Green’s functions, leading to misinterpretation of the slip distribution. We show that all three data sets are required to give an accurate description of the Wenchuan rupture. The moment is estimated to be approximately 1.0 × 1021 N · m with the slip characterized by multiple large patches with slips up to 10 m. Rupture initiates on the southern end of the Pengguan fault and proceeds unilaterally to the northeast. Upon reaching the cross-cutting Xiaoyudong fault, rupture of the adjacent Beichuan fault starts at this juncture and proceeds bilaterally to the northeast and southwest.

  1. Joint Control for Dummies*: An Elaboration of Lowenkron's Model of Joint (Stimulus) Control.

    PubMed

    Sidener, David W

    2006-01-01

    The following paper describes Lowenkron's model of joint (stimulus) control. Joint control is described as a means of accounting for performances, especially generalized performances, for which a history of contingency control does not provide an adequate account. Examples are provided to illustrate instances in which joint control may facilitate performance of a task.

  2. Joint Control for Dummies*: An Elaboration of Lowenkron's Model of Joint (Stimulus) Control

    PubMed Central

    Sidener, David W

    2006-01-01

    The following paper describes Lowenkron's model of joint (stimulus) control. Joint control is described as a means of accounting for performances, especially generalized performances, for which a history of contingency control does not provide an adequate account. Examples are provided to illustrate instances in which joint control may facilitate performance of a task. PMID:22477350

  3. Joint Control for Dummies: An Elaboration of Lowenkron's Model of Joint (Stimulus) Control

    ERIC Educational Resources Information Center

    Sidener, David W.

    2006-01-01

    The following paper describes Lowenkron's model of joint (stimulus) control. Joint control is described as a means of accounting for performances, especially generalized performances, for which a history of contingency control does not provide an adequate account. Examples are provided to illustrate instances in which joint control may facilitate…

  4. Demographic estimation methods for plants with dormancy

    USGS Publications Warehouse

    Kery, M.; Gregg, K.B.

    2004-01-01

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

  5. Ceramic joints

    DOEpatents

    Miller, Bradley J.; Patten, Jr., Donald O.

    1991-01-01

    Butt joints between materials having different coefficients of thermal expansion are prepared having a reduced probability of failure of stress facture. This is accomplished by narrowing/tapering the material having the lower coefficient of thermal expansion in a direction away from the joint interface and not joining the narrow-tapered surface to the material having the higher coefficient of thermal expansion.

  6. Febrile Seizure: Demographic Features and Causative Factors

    PubMed Central

    ESMAILI GOURABI, Hamed; BIDABADI, Elham; CHERAGHALIPOUR, Fatemeh; AARABI, Yasaman; SALAMAT, Fatemeh

    2012-01-01

    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. 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. PMID:24665278

  7. [Population education. The school and demographic demographic knowledge].

    PubMed

    Camarena Cordova, R M

    1991-01-01

    Population education is recognized as a means of promoting changes in demographic behavior. Mexico's 1973 General Law of Population and its associated regulations assigned to education an important role in supporting the population policy. Inclusion of population content in curricular programs at the basic education level has been a major action. Content referring to sexuality, responsible parenthood, and human reproduction was introduced into the curriculum as part of the 1974 educational reform, and other topics such as family, health care, and environment were reformulated to emphasize their connection to demographic policy. The curricular change was important, but was not supported by later actions to enrich it and keep it up to date. The population education curriculum in basic education was never evaluated. Some studies of the knowledge and atti tudes of adolescents regarding sexuality, contraception, and reproduction have demonstrated the importance of the school as a channel of information but have also raised doubts about the quality and effectiveness of existing curricula. Other studies have found the population education content in primary texts to be too general, superficial, incomplete, and stereotyped in the treatment of some themes. The population education curriculum began to be reconsidered beginning in the mid-1980s. An interinstitutional group is now redefining and redesigning the population education materials that will be included in the plans, programs, and supporting material for basic education that will result from the current program for educational modernization. The relevance of these actions is obvious, despite their neglect by demographers. In the 1990-91 school year, 18.3 million children will be registered in primary and secondary schools, a figure representing 22.9% of the total 1990 population. In other words, over 20% of Mexicans will be potential recipients of population education.

  8. 13. Sacroiliac joint pain.

    PubMed

    Vanelderen, Pascal; Szadek, Karolina; Cohen, Steven P; De Witte, Jan; Lataster, Arno; Patijn, Jacob; Mekhail, Nagy; van Kleef, Maarten; Van Zundert, Jan

    2010-01-01

    The sacroiliac joint accounts for approximately 16% to 30% of cases of chronic mechanical low back pain. Pain originating in the sacroiliac joint is predominantly perceived in the gluteal region, although pain is often referred into the lower and upper lumbar region, groin, abdomen, and/ or lower limb(s). Because sacroiliac joint pain is difficult to distinguish from other forms of low back pain based on history, different provocative maneuvers have been advocated. Individually, they have weak predictive value, but combined batteries of tests can help ascertain a diagnosis. Radiological imaging is important to exclude "red flags" but contributes little in the diagnosis. Diagnostic blocks are the diagnostic gold standard but must be interpreted with caution, because false-positive as well as false-negative results occur frequently. Treatment of sacroiliac joint pain is best performed in the context of a multidisciplinary approach. Conservative treatments address the underlying causes (posture and gait disturbances) and consist of exercise therapy and manipulation. Intra-articular sacroiliac joint infiltrations with local anesthetic and corticosteroids hold the highest evidence rating (1 B+). If the latter fail or produce only short-term effects, cooled radiofrequency treatment of the lateral branches of S1 to S3 (S4) is recommended (2 B+) if available. When this procedure cannot be used, (pulsed) radiofrequency procedures targeted at L5 dorsal ramus and lateral branches of S1 to S3 may be considered (2 C+).

  9. The Joint Cargo Aircraft Legislative Issues and the Way Ahead

    DTIC Science & Technology

    2009-05-01

    color images. 14. ABSTRACT The Joint Cargo Aircraft (JCA), a joint acquisition program between the Army and Air Force, has had an unusual history, and... acquisition processes, and proper organization of each military branch. As an introduction to this topic, this paper intends to describe briefly the basic JCA...Abstract The Joint Cargo Aircraft (JCA), a joint acquisition program between the Army and Air Force, has had an unusual history, and has been a

  10. Comparative demographics of a Hawaiian forest bird community

    USGS Publications Warehouse

    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

  11. Compliant joint

    NASA Technical Reports Server (NTRS)

    Eklund, Wayne D. (Inventor); Kerley, James J. (Inventor)

    1990-01-01

    A compliant joint is provided for prosthetic and robotic devices which permits rotation in three different planes. The joint provides for the controlled use of cable under motion. Perpendicular outer mounting frames are joined by swaged cables that interlock at a center block. Ball bearings allow for the free rotation of the second mounting frame relative to the first mounting frame within a predetermined angular rotation that is controlled by two stop devices. The cables allow for compliance at the stops and the cables allow for compliance in six degrees of freedom enabling the duplication or simulation of the rotational movement and flexibility of a natural hip or knee joint, as well as the simulation of a joint designed for a specific robotic component for predetermined design parameters.

  12. Joint Commission

    MedlinePlus

    Skip to main content The Joint Commission Log In | Request Guest Access Forgot password? | Log In Help Contact Us | Careers | JCR Web Store | Press Room Search Home Accreditation Accreditation Ambulatory Health ...

  13. Alcohol Consumption in Demographic Subpopulations

    PubMed Central

    Delker, Erin; Brown, Qiana; Hasin, Deborah S.

    2016-01-01

    Alcohol consumption is common across subpopulations in the United States. However, the health burden associated with alcohol consumption varies across groups, including those defined by demographic characteristics such as age, race/ethnicity, and gender. Large national surveys, such as the National Epidemiologic Survey on Alcohol and Related Conditions and the National Survey on Drug Use and Health, found that young adults ages 18–25 were at particularly high risk of alcohol use disorder and unintentional injury caused by drinking. These surveys furthermore identified significant variability in alcohol consumption and its consequences among racial/ethnic groups. White respondents reported the highest prevalence of current alcohol consumption, whereas alcohol abuse and dependence were most prevalent among Native Americans. Native Americans and Blacks also were most vulnerable to alcohol-related health consequences. Even within ethnic groups, there was variability between and among different subpopulations. With respect to gender, men reported more alcohol consumption and binge drinking than women, especially in older cohorts. Men also were at greater risk of alcohol abuse and dependence, liver cirrhosis, homicide after alcohol consumption, and drinking and driving. Systematic identification and measurement of the variability across demographics will guide prevention and intervention efforts, as well as future research. PMID:27159807

  14. Exoplanet Demographics with Microlensing Surveys

    NASA Astrophysics Data System (ADS)

    Gaudi, B.

    2014-04-01

    Because of its unique sensitivity to low-mass, long-period, and free-floating planets, microlensing is an essential complement to our arsenal of planet detection methods. I motivate microlensing surveys for exoplanets, and in particular describe how they can be used to test models for planet formation, as well as inform our understanding of the frequency and potential habitability of low-mass planets located in the habitable zones of their host stars. I review results from current microlensing surveys, and then discuss expectations for next-generation experiments. I explain why a space-based mission is necessary to realize the full potential of microlensing. When combined with the results from complementary surveys such as Kepler, a space-based microlensing survey will yield a nearly complete picture of the demographics of planetary systems throughout the Galaxy.

  15. Demographic parameters and natural selection.

    PubMed

    Demetrius, L

    1974-12-01

    This paper introduces two new demographic parameters, the entropy and the reproductive potential of a population. The entropy of a population measures the variability of the contribution of the different age classes to the stationary age distribution. The reproductive potential measures the mean of the contribution of the different age classes to the growth rate. Using a relation between these measures and the Malthusian parameter, it is shown that in a random mating population in Hardy-Weinberg equilibrium, and under slow selection, the rate of change of entropy is equal to the genetic variance in entropy minus the genetic covariance of entropy and reproductive potential. This result is an analogue of Fisher's fundamental theorem of natural selection.

  16. The prevalence of chondrocalcinosis (CC) of the acromioclavicular (AC) joint on chest radiographs and correlation with calcium pyrophosphate dihydrate (CPPD) crystal deposition disease.

    PubMed

    Parperis, Konstantinos; Carrera, Guillermo; Baynes, Keith; Mautz, Alan; Dubois, Melissa; Cerniglia, Ross; Ryan, Lawrence M

    2013-09-01

    Digital imaging combined with picture archiving and communication system (PACS) access allows detailed image retrieval and magnification. Calcium pyrophosphate dihydrate (CPPD) crystals preferentially deposit in fibrocartilages, the cartilage of the acromioclavicular (AC) joint being one such structure. We sought to determine if examination of the AC joints on magnified PACS imaging of chest films would be useful in identifying chondrocalcinosis (CC). Retrospective radiographic readings and chart reviews involving 1,920 patients aged 50 or more who had routine outpatient chest radiographs over a 4-month period were performed. Knee radiographs were available for comparison in 489 patients. Medical records were reviewed to abstract demographics, chest film reports, and diagnoses. AC joint CC was identified in 1.1 % (21/1,920) of consecutive chest films. Patients with AC joint CC were 75 years of age versus 65.4 in those without CC (p < 0.0002). Four hundred eighty-nine patients had knee films. Six of these patients had AC joint CC, and of these, five also had knee CC (83 %). Of the 483 without AC joint CC, 62 (12 %) had knee CC (p = 0.002). Patients with AC joint CC were more likely to have a recorded history of CPPD crystal deposition disease than those without AC joint CC (14 versus 1 %, p = 0.0017). The prevalence of AC joint CC increases with age and is associated with knee CC. A finding of AC joint CC should heighten suspicion of pseudogout or secondary osteoarthritis in appropriate clinical settings and, in a young patient, should alert the clinician to the possibility of an associated metabolic condition.

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

    PubMed Central

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

    2013-01-01

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

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

    PubMed

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

    2013-12-01

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

  19. Demographic Change and Parent-Child Relationships in Adulthood

    PubMed Central

    Seltzer, Judith A.; Bianchi, Suzanne M.

    2014-01-01

    Demographic changes in who becomes a parent, how many children parents have, and the marital statuses of parents and children affect the extent to which parents and adult children provide for each other later in life. We describe these demographic changes and their implications for the help parents and children give each other throughout their adult years. The changing demography of US families has increased both generations’ need for family assistance among those already disadvantaged and has exacerbated differences between the socioeconomically advantaged and disadvantaged in the availability of kin support. Variations in the marital histories of parents and children also contribute to a divergence between mother-child and father-child relationships in later life. The churning of couple relationships in both generations blurs the boundaries between who is in the family and who is not, threatening the effectiveness of the family safety net among those who may need it the most. PMID:25378767

  20. The Security Dynamics of Demographic Factors

    DTIC Science & Technology

    2000-01-01

    in the public domain. The principal aim of this report is to provide a framework for understanding the influence of demographic factors on...This report presents a framework for understanding the implications of global demographic trends for international and U.S. national Security. One of...its goals is to spark discussion between demographers and national security analysts. The document should be of interest to security analysts

  1. Australian Defence Force Demographic Data and Challenges

    DTIC Science & Technology

    2001-10-01

    AUSTRALIAN DEFENCE FORCE DEMOGRAPHIC DATA AND CHALLENGES Directorate of Strategic Personnel Planning and Research DSPPR Technical Note 10/2001...DATE 00 OCT 2001 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Australian Defence Force Demographic Data and Challenges 5a...Prescribed by ANSI Std Z39-18 AUSTRALIAN DEFENCE FORCE DEMOGRAPHIC DATA AND CHALLENGES The findings and views expressed in this report are the results

  2. Posttraumatic Temporomandibular Joint Disorders

    PubMed Central

    Giannakopoulos, Helen E.; Quinn, Peter D.; Granquist, Eric; Chou, Joli C.

    2009-01-01

    The temporomandibular joint (TMJ) has many essential functions. None of its components are exempt from injury. Facial asymmetry, malocclusion, disturbances in growth, osteoarthritis, and ankylosis can manifest as complications from trauma to the TMJ. The goals of initial treatment include achievement of pretraumatic function, restoration of facial symmetry, and resolution of pain. These same objectives hold true for late repairs and reconstruction of the TMJ apparatus. Treatment is demanding, and with opposing approaches. The following article explores various treatment options for problems presenting as a result of a history of trauma to the TMJ. PMID:22110802

  3. Acromioclavicular and sternoclavicular joint injuries.

    PubMed

    Macdonald, Peter B; Lapointe, Pierre

    2008-10-01

    Acromioclavicular (AC) joint injuries are a frequent diagnosis following an acute shoulder injury. The literature on AC joint dislocation is extensive, reflecting the intense debate surrounding the topic. The choice of treatment is influenced by factors including the type of injury, the patient's occupation, the patient's past medical history, the acuity of the injury, and patient expectations. Sternoclavicular (SC) joint dislocation is an uncommon injury. The treatment of acute anterior SC joint dislocations is controversial. It is difficult to study with a well-designed prospective study because of the low frequency of this injury. Posterior dislocations are much less common than anterior dislocations. Posterior dislocations, however, are more serious; they are associated with significant complications and require prompt attention.

  4. Demographic studies of extrasolar planets

    NASA Astrophysics Data System (ADS)

    Morton, Timothy

    Uncovering the demographics of extrasolar planets is crucial to understanding the processes of their formation and evolution. In this thesis, we present four studies that contribute to this end, three of which relate to NASA's Kepler mission, which has revolutionized the field of exoplanets in the last few years. In the pre-Kepler study, we investigate a sample of exoplanet spin-orbit measurements---measurements of the inclination of a planet's orbit relative to the spin axis of its host star---to determine whether a dominant planet migration channel can be identified, and at what confidence. Applying methods of Bayesian model comparison to distinguish between the predictions of several different migration models, we find that the data strongly favor a two-mode migration scenario combining planet-planet scattering and disk migration over a single-mode Kozai migration scenario. While we test only the predictions of particular Kozai and scattering migration models in this work, these methods may be used to test the predictions of any other spin-orbit misaligning mechanism. We then present two studies addressing astrophysical false positives in Kepler data. The Kepler mission has identified thousands of transiting planet candidates, and only relatively few have yet been dynamically confirmed as bona fide planets, with only a handful more even conceivably amenable to future dynamical confirmation. As a result, the ability to draw detailed conclusions about the diversity of exoplanet systems from Kepler detections relies critically on understanding the probability that any individual candidate might be a false positive. We show that a typical a priori false positive probability for a well-vetted Kepler candidate is only about 5-10%, enabling confidence in demographic studies that treat candidates as true planets. We also present a detailed procedure that can be used to securely and efficiently validate any individual transit candidate using detailed information of the

  5. The Importance of Demographic Data in Astronomy

    NASA Astrophysics Data System (ADS)

    Elmegreen, Debra M.

    2014-01-01

    The most effective astronomical workforce will be one that comprises a diverse and inclusive community. The “New Worlds, New Horizons in Astronomy and Astrophysics” Decadal Survey, with input from its Infrastructure Study Group on Demographics, provided an overview of recent demographic trends. Demographics in astronomy have undergone significant changes over the past two generations in several, but not all, categories. Maintaining records of demographics regarding age, gender, and minority status, as well as trends by discipline and career choices, is vital in planning for the future training and employment of astronomers.

  6. Hypermobile joints

    MedlinePlus

    ... A.M. Editorial team. Related MedlinePlus Health Topics Joint Disorders Browse the Encyclopedia A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an ...

  7. Broadening the Demographics at NIST

    NASA Astrophysics Data System (ADS)

    Gebbie, Katharine B.

    2001-04-01

    Scientists have the rare privilege of earning their living by doing what they most enjoy. Women and minorities have the right, the need and the talent to compete for that privilege. And if the profession is to serve its goal of advancing, diffusing and applying the knowledge of science, it must draw upon the widest possible spectrum of talented individuals--the best and the brightest from all segments of society. This talk will discuss and evaluate efforts at NIST to ensure that women and minorities have the opportunity to participate fully in the scientific endeavor. These efforts include close collaboration with predominantly female and minority colleges; programs for students interested in pursuing advanced education; and a Summer Undergraduate Research Fellowship (SURF) program, sponsored jointly with NSF, that affords 50 students the opportunity to spend 12 weeks engaged one-on-one with NIST scientists in projects combining quests for fundamental knowledge with direct applications to problems of national importance.

  8. Intellectual History, Social History, Cultural History...and Our History.

    ERIC Educational Resources Information Center

    Nord, David Paul

    1990-01-01

    Defines and explores the links among intellectual, social, and cultural history. Warns that an adequate foundation must be laid in the economic and institutional social history of mass media before communication historians jump into cultural history. (SR)

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

    ERIC Educational Resources Information Center

    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…

  10. The Unaddressed Costs of Changing Student Demographics

    ERIC Educational Resources Information Center

    Kaplan, Leslie S.; Owings, William A.

    2013-01-01

    This article discusses the impact of changing student demographics on financing education and on our national wellbeing. We begin by examining the research of current student demographics and their relationship to learning and education costs. We then calculate a 1% cost factor from the average per-pupil expenditure based on the 2011 "Digest…

  11. Lifelong Learning and Demographics: A Japanese Perspective

    ERIC Educational Resources Information Center

    Ogawa, Seiko

    2005-01-01

    This paper explores the social dimension of lifelong learning from the perspective of demographics, with particular focus on the issue of the birth of fewer children, which has become one of the most important current social issues in Japanese society. When considering the relationship between lifelong learning and demographics, the issues arising…

  12. [The Brazilian population: demographic and spatial dynamics].

    PubMed

    Bret, B; Le Gauffey, Y; Thery, H; Waniez, P

    1984-01-01

    Recent demographic trends in Brazil are reviewed. A continuing decline in fertility is noted as the demographic transition proceeds. The differences by region and between rural and urban areas are considered. Attention is also paid to differences in spatial distribution and to internal migration.

  13. [The ecological limits to demographic growth].

    PubMed

    Raffestin, C

    1989-09-01

    Although most individuals are able to conceive of limitations on local resources, the idea that global resources are also potentially exhaustible appears harder to grasp. Not only are soil resources exhaustible, but the total vegetal biomass is ultimately limited by the fixed quantity of energy received from the sun. If the biomass is finite, the human population must also be finite. It would be very difficult to estimate the size of the human population that could be supported on earth because of the very different use of resources by different groups. Roughly 76% of the world's 5 billion persons live in the developing countries, and most of them weigh less heavily on the ecosystem as individuals than do persons living in the developed countries. Despite the difficulties of defining an ecologic limit on growth, the topic has held a certain fascination throughout history and various attempts have been made, most recently in 1972 with "The Limits of Growth". The question of ecological limits to growth is implicitly or explicitly posed in terms of 3 major problems: food resources, the physical capacity of ecosystems, and the territoriality of populations within ecosystems. The problem is made more complex by the fact that the objective of human societies compatible with resources. Soil erosion, inappropriate agricultural practices, pollution, the automobile and waste disposal are examples of technological aspects of society whose costs have not been rationally dealth with and which are not managed in a satisfactory manner in contemporary life. All economic and demographic growth carries with it bioecological degradation. The question of whether the earth is now overpopulated cannot be answered precisely. Nevertheless, the terrestrial ecosystem is in crisis; it is being degraded faster than it can be restored. There are no more free goods; air and water are not free.

  14. The Epidemiology and Demographics of Hip Dysplasia

    PubMed Central

    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

  15. Ancient DNA and human history

    PubMed Central

    Slatkin, Montgomery; Racimo, Fernando

    2016-01-01

    We review studies of genomic data obtained by sequencing hominin fossils with particular emphasis on the unique information that ancient DNA (aDNA) can provide about the demographic history of humans and our closest relatives. We concentrate on nuclear genomic sequences that have been published in the past few years. In many cases, particularly in the Arctic, the Americas, and Europe, aDNA has revealed historical demographic patterns in a way that could not be resolved by analyzing present-day genomes alone. Ancient DNA from archaic hominins has revealed a rich history of admixture between early modern humans, Neanderthals, and Denisovans, and has allowed us to disentangle complex selective processes. Information from aDNA studies is nowhere near saturation, and we believe that future aDNA sequences will continue to change our understanding of hominin history. PMID:27274045

  16. Ancient DNA and human history.

    PubMed

    Slatkin, Montgomery; Racimo, Fernando

    2016-06-07

    We review studies of genomic data obtained by sequencing hominin fossils with particular emphasis on the unique information that ancient DNA (aDNA) can provide about the demographic history of humans and our closest relatives. We concentrate on nuclear genomic sequences that have been published in the past few years. In many cases, particularly in the Arctic, the Americas, and Europe, aDNA has revealed historical demographic patterns in a way that could not be resolved by analyzing present-day genomes alone. Ancient DNA from archaic hominins has revealed a rich history of admixture between early modern humans, Neanderthals, and Denisovans, and has allowed us to disentangle complex selective processes. Information from aDNA studies is nowhere near saturation, and we believe that future aDNA sequences will continue to change our understanding of hominin history.

  17. Joint assembly

    NASA Technical Reports Server (NTRS)

    Wilson, Andrew (Inventor); Punnoose, Andrew (Inventor); Strausser, Katherine (Inventor); Parikh, Neil (Inventor)

    2010-01-01

    A joint assembly is provided which includes a drive assembly and a swivel mechanism. The drive assembly features a motor operatively associated with a plurality of drive shafts for driving auxiliary elements, and a plurality of swivel shafts for pivoting the drive assembly. The swivel mechanism engages the swivel shafts and has a fixable element that may be attached to a foundation. The swivel mechanism is adapted to cooperate with the swivel shafts to pivot the drive assembly with at least two degrees of freedom relative to the foundation. The joint assembly allows for all components to remain encased in a tight, compact, and sealed package, making it ideal for space, exploratory, and commercial applications.

  18. [Contemplations on demographic theories (author's transl)].

    PubMed

    Maier, W

    1979-03-01

    All demographic theories make statements on the relationship between population developments and economic developments. The demographic teachings of Adam Smith, Thomas Robert Malthus, and Karl Marx are embedded in their specific economic theories and contain ideologic statements which are not detrimental to demographic and economic sciences but a stimulus for research. The demographic theories which developed with the onset of the industrial revolution of the 19th century are all sceptical of too high populations independent of their analysis of the market mechanisms or of capitalistic production relationships. This has remained unchanged to date. The statistical evaluation of the 1980's underlines this problem. The reproductive behaviour and demographic theory of a highly industrialized economy can not be based on experience alone but must also be based on rational findings. The rejection of the prestige value of children on the reproductive behaviour which is independent of circumstances must be recognized.

  19. A Demographic Perspective on Family Change

    PubMed Central

    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

  20. The joint allele frequency spectrum of multiple populations: a coalescent theory approach.

    PubMed

    Chen, Hua

    2012-03-01

    The allele frequency spectrum is a series of statistics that describe genetic polymorphism, and is commonly used for inferring population genetic parameters and detecting natural selection. Population genetic theory on the allele frequency spectrum for a single population has been well studied using both coalescent theory and diffusion equations. Recently, the theory was extended to the joint allele frequency spectrum (JAFS) for three populations using diffusion equations and was shown to be very useful in inferring human demographic history. In this paper, I show that the JAFS can be analytically derived with coalescent theory for a basic model of two isolated populations and then extended to multiple populations and various complex scenarios, such as those involving population growth and bottleneck, migration, and positive selection. Simulation study is used to demonstrate the accuracy and applicability of the theoretical model. The coalescent theory-based approach for the JAFS can characterize the demographic history with comprehensive statistical models as the diffusion approach does, and in addition gains several novel advantages: the computational complexity of calculating the JAFS with coalescent theory is reduced, and thus it is feasible to analytically obtain the JAFS for multiple populations; the hitchhiking effect can be efficiently modeled in coalescent theory, enabling the development of methodologies for detecting selection via multi-population polymorphism data. As an alternative to the diffusion approximation approach, the coalescent theory for the JAFS also provides a foundation for population genetic inference with the advent of large-scale genomic polymorphism data.

  1. Joint Warrior

    DTIC Science & Technology

    2011-05-04

    hour per response , including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and...reflect my own personal views and are not necessarily endorsed by the NWC or the Department of the Navy. 14. ABSTRACT The way we fight wars has been...evolving over thousands of years. Today, the U.S. Navy, finds itself in the post- modern area of war fighting . Joint warfare is the latest

  2. Demographic training and research in Africa.

    PubMed

    Igun, A A

    1976-09-01

    The state of demographic data in Africa is reviewed in this paper along with constraints affecting the collection of adequate demographic information. An evaluation is made of the present situation and efforts to rectify the shortage of demographic personnel in the UN sponsored subregional demographic institutes, including an outline of the course program. The effort and progress being made in similar training programs at the University of Ife, Nigeria, is also examined. Obstacles to the collection of demographic data are classified as physical difficulties; administrative and official problems and difficulties; technical and staff problems; and sociocultural problems. A consensus has been reached on the inadequacy of past efforts in data collection and analysis in Africa. Special attention must be paid to the training of demographers. A comparison is made between demographers in developed countries who have their data collected for them and the African demographer who must be his own statistician, sociologist, anthropologist, and geographer to understand the biases his data are subject to. Training for African demographers should emphasize problems in data collection, data manipulation, and innovation in solving methodological problems. Type of personnel needed include teachers of demography, high level professionals, middle level professionals and low level workers. The training programs given by the Regional Institutes for Population Studies are a postgraduate diploma course, lasting 1 year and a Master's degree course for those who obtain the diploma. Subjects covered include substantive demography; technical demography; family planning, its development and evaluation; auxiliary subjects including mathematics, statistics, sampling and research methods; and complementary subjects e.g., economics, sociology, national planning, physiology of reproduction, and genetics. Short term research projects and a major research report are an integral part of the programs

  3. General properties of joints and joint networks in subhorizontally layered reservoir rocks

    SciTech Connect

    Verbeek, E.R.; Grout, M.A. )

    1993-09-01

    Properties of individual joints and joint networks in flat-lying, nearly underformed rocks are consistently and predictably related to lithology and to stratal sequence in the following ways. (1) Orientations: Strike dispersions of 15-30[degrees] within joint sets approximate normal distributions. Smaller dispersions are known for early formed sets within fine-grained, well-cemented, brittle rocks; dispersions increase with increasing layer thickness, grain size, and friability. Dip dispersions increase with changes in rock properties. (2) Dimensions: Joint heights are influenced by thickness of depositional units and degree of lithologic contrast between them. The smallest joints form in thinly bedded sequences of contrasting rock type; the largest are in thick, internally homogeneous units and sequences of low lithologic contrast. A correspondence exists between joint height and length for early joints, but lengths of later ones are increasingly influenced by preexisting joints and tend to become progressively smaller for successive sets. (3) Spacing: Joint spacings are influenced by lithology and thickness of the jointed layer through a relation of the form log S = m log T + c, where S = median joint spacing, T = mechanical layer thickness, and m and c are constants dependent on lithology. Mechanical layer thickness may be greater or less than bed thickness depending on lithologic contrast between beds and degree of lithologic homogeneity within beds. (4) Interconnections: The relative proportions of [open quotes]blind[close quotes] endings, terminations, and intersections among joints differ from set to set as a function of the mineralization history and spacings of preexisting joints. (5) Apertures: For early, isolated cracks, joint shapes in cross section are biconvex, and maximum aperture at joint midpoint is proportional to joint length; thus, all joints have approximately the same shape regardless of size. No such relation exists for joints of later sets.

  4. Demographic threats to the sustainability of Brazil nut exploitation.

    PubMed

    Peres, Carlos A; Baider, Claudia; Zuidema, Pieter A; Wadt, Lúcia H O; Kainer, Karen A; Gomes-Silva, Daisy A P; Salomão, Rafael P; Simões, Luciana L; Franciosi, Eduardo R N; Cornejo Valverde, Fernando; Gribel, Rogério; Shepard, Glenn H; Kanashiro, Milton; Coventry, Peter; Yu, Douglas W; Watkinson, Andrew R; Freckleton, Robert P

    2003-12-19

    A comparative analysis of 23 populations of the Brazil nut tree (Bertholletia excelsa) across the Brazilian, Peruvian, and Bolivian Amazon shows that the history and intensity of Brazil nut exploitation are major determinants of population size structure. Populations subjected to persistent levels of harvest lack juvenile trees less than 60 centimeters in diameter at breast height; only populations with a history of either light or recent exploitation contain large numbers of juvenile trees. A harvesting model confirms that intensive exploitation levels over the past century are such that juvenile recruitment is insufficient to maintain populations over the long term. Without management, intensively harvested populations will succumb to a process of senescence and demographic collapse, threatening this cornerstone of the Amazonian extractive economy.

  5. Joint service EOD robotics program

    NASA Astrophysics Data System (ADS)

    Hacker, Kurt; Brezina, Byron; DeBolt, Chris

    2006-05-01

    Within the military, the Explosive Ordnance Disposal (EOD) community has been an early adopter of robotic capabilities. The Joint Service EOD (JSEOD) Program is in the process of fielding its third generation of robotic systems to the EOD technicians. Robots have been an invaluable asset to the EOD technician, and they have been critical to operations in Iraq as we prosecute the IED problem. This paper provides a brief history of past EOD robotic systems, a description of currently fielded and supported systems, and the future of robotic programs within the Joint Service EOD community.

  6. Temporomandibular joint disorders in children.

    PubMed

    Howard, James A

    2013-01-01

    A child's difficulty in verbalizing the precise location and nature of facial pain and jaw dysfunction often results in a nondefinitive history, increasing the importance of the dentist's awareness of the early signs and symptoms of temporomandibular joint disorders (TMD). A focused examination of the masticatory musculature, the temporomandibular joints, and associated capsular and ligamentous structures can reveal if a patient's symptoms are TMD in origin. An accurate differential diagnosis enables timely referral to appropriate health care providers and minimizes the use of diagnostic imaging.

  7. Demographic diversity and sustainable fisheries.

    PubMed

    Fujiwara, Masami

    2012-01-01

    Fish species are diverse. For example, some exhibit early maturation while others delay maturation, some adopt semelparous reproductive strategies while others are iteroparous, and some are long-lived and others short-lived. The diversity is likely to have profound effects on fish population dynamics, which in turn has implications for fisheries management. In this study, a simple density-dependent stage-structured population model was used to investigate the effect of life history traits on sustainable yield, population resilience, and the coefficient of variation (CV) of the adult abundance. The study showed that semelparous fish can produce very high sustainable yields, near or above 50% of the carrying capacity, whereas long-lived iteroparous fish can produce very low sustainable yields, which are often much less than 10% of the carrying capacity. The difference is not because of different levels of sustainable fishing mortality rate, but because of difference in the sensitivity of the equilibrium abundance to fishing mortality. On the other hand, the resilience of fish stocks increases from delayed maturation to early maturation strategies but remains almost unchanged from semelparous to long-lived iteroparous. The CV of the adult abundance increases with increased fishing mortality, not because more individuals are recruited into the adult stage (as previous speculated), but because the mean abundance is more sensitive to fishing mortality than its standard deviation. The magnitudes of these effects vary depending on the life history strategies of the fish species involved. It is evident that any past high yield of long-lived iteroparous fish is a transient yield level, and future commercial fisheries should focus more on fish that are short-lived (including semelparous species) with high compensatory capacity.

  8. Investigation of the Demographic and Selective Forces Shaping the Nucleotide Diversity of Genes Involved in Nod Factor Signaling in Medicago truncatula

    PubMed Central

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

    2007-01-01

    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. PMID:18073426

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

    PubMed

    Jones, F A; Hubbell, S P

    2006-10-01

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

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

    PubMed

    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.

  11. [Joint infections. Known facts and new trends].

    PubMed

    Diefenbeck, M; Abitzsch, D; Hofmann, G O

    2012-06-01

    Acute septic arthritis is a surgical emergency because rapid septic destruction of articular cartilage can lead to impairment or even loss of joint function. Diagnosis consists of patient history, clinical examination, laboratory results, (sonography- guided) joint aspiration and radiography. Emergency therapy is based on arthroscopic or open joint debridement and lavage combined with systemic antibiotic therapy. No data are available for the recommendation of local antibiotics but antiseptic solutions are not recommended because of cartilage damage. New trends in diagnostics are positron emission tomography/computed tomography (PET/CT), urine sticks for analysis of joint fluid and molecular pathology. Chronic joint empyema is more diagnostically demanding and is difficult to treat. In cases of necrotic and infected articular cartilage, joint resection has to be performed for quiescence of infection. Options following successful treatment of empyema are arthroplasty, arthrodesis or permanent resection.

  12. The Joint Effects of Lifestyle Factors and Comorbidities on the Risk of Colorectal Cancer: A Large Chinese Retrospective Case-Control Study

    PubMed Central

    Hu, Hai; Zhou, Yangyang; Ren, Shujuan; Wu, Jiajin; Zhu, Meiying; Chen, Donghui; Yang, Haiyan; Wang, Liwei

    2015-01-01

    Background Colorectal cancer (CRC) is a major cause of cancer morbidity and mortality. In previous epidemiologic studies, the respective correlation between lifestyle factors and comorbidity and CRC has been extensively studied. However, little is known about their joint effects on CRC. Methods We conducted a retrospective case-control study of 1,144 diagnosed CRC patients and 60,549 community controls. A structured questionnaire was administered to the participants about their socio-demographic factors, anthropometric measures, comorbidity history and lifestyle factors. Logistic regression model was used to calculate the odds ratio (ORs) and 95% confidence intervals (95%CIs) for each factor. According to the results from logistic regression model, we further developed healthy lifestyle index (HLI) and comorbidity history index (CHI) to investigate their independent and joint effects on CRC risk. Results Four lifestyle factors (including physical activities, sleep, red meat and vegetable consumption) and four types of comorbidity (including diabetes, hyperlipidemia, history of inflammatory bowel disease and polyps) were found to be independently associated with the risk of CRC in multivariant logistic regression model. Intriguingly, their combined pattern- HLI and CHI demonstrated significant correlation with CRC risk independently (ORHLI: 3.91, 95%CI: 3.13–4.88; ORCHI: 2.49, 95%CI: 2.11–2.93) and jointly (OR: 10.33, 95%CI: 6.59–16.18). Conclusions There are synergistic effects of lifestyle factors and comorbidity on the risk of colorectal cancer in the Chinese population. PMID:26710070

  13. Differentiate or Die: Colleges Need a Clear Niche to Thrive in the Coming Demographic Crisis

    ERIC Educational Resources Information Center

    Handy, Ty J.

    2008-01-01

    New England higher education is about to experience a decade-long demographic crisis unlike anything in its history. While the crisis will significantly affect all six New England States, it will be most acute in the three northern states, as the competition for qualified high school graduates begins to intensify. The New England states, including…

  14. The demographic work of Sir William Wilde.

    PubMed

    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.

  15. Unemployment among Black Youths, Demographics, and Crime.

    ERIC Educational Resources Information Center

    Calvin, Allen D.

    1981-01-01

    Erroneous conclusions relating to the interrelationship among unemployment rates, demographics, and crime rates of Black youths are discussed. A reexamination of the data shows that crime by Black youths bears a close relationship with prevailing economic conditions. (Author/RC)

  16. Teaching Family History: Papers from Old Sturbridge Village.

    ERIC Educational Resources Information Center

    Journal of Family History, 1981

    1981-01-01

    Essays in this special issue of the "Journal of Family History" focus on the teaching of family history by using artifacts. The articles were written by the staff at Old Sturbridge Village (OSV). The first article discusses how family history is taught at OSV. Students study a real family using demographic information and artifacts such as…

  17. Joint appointments in practice positions.

    PubMed

    Hutelmyer, C M; Donnelly, G F

    1996-01-01

    Faculty practice has been a value in both nursing education and nursing service. Recent changes in education provide the opportunity for practice to be rewarded in the university setting. Changes in health care delivery demand expert practitioners and leadership in advanced practice nursing. The history of education-practice integration is reviewed. A new role of the practitioner educator (reverse joint appointee) is presented. Benefits of the position to both education and practice are discussed.

  18. Health & Demographic Surveillance System Profile: The Ifakara Rural and Urban Health and Demographic Surveillance System (Ifakara HDSS).

    PubMed

    Geubbels, Eveline; Amri, Shamte; Levira, Francis; Schellenberg, Joanna; Masanja, Honorati; Nathan, Rose

    2015-06-01

    The Ifakara Rural HDSS (125,000 people) was set up in 1996 for a trial of the effectiveness of social marketing of bed nets on morbidity and mortality of children aged under 5 years, whereas the Ifakara Urban HDSS (45,000 people) since 2007 has provided demographic indicators for a typical small urban centre setting. Jointly they form the Ifakara HDSS (IHDSS), located in the Kilombero valley in south-east Tanzania. Socio-demographic data are collected twice a year. Current malaria work focuses on phase IV studies for antimalarials and on determinants of fine-scale variation of pathogen transmission risk, to inform malaria elimination strategies. The IHDSS is also used to describe the epidemiology and health system aspects of maternal, neonatal and child health and for intervention trials at individual and health systems levels. More recently, IHDSS researchers have studied epidemiology, health-seeking and national programme effectiveness for chronic health problems of adults and older people, including for HIV, tuberculosis and non-communicable diseases. A focus on understanding vulnerability and designing methods to enhance equity in access to services are cross-cutting themes in our work. Unrestricted access to core IHDSS data is in preparation, through INDEPTH iSHARE [www.indepth-ishare.org] and the IHI data portal [http://data.ihi.or.tz/index.php/catalog/central].

  19. Community History.

    ERIC Educational Resources Information Center

    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.…

  20. Joint x-ray

    MedlinePlus

    X-ray - joint; Arthrography; Arthrogram ... x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be moved into other positions for more ...

  1. [Thoughts on demographic optimization in contemporary Poland].

    PubMed

    Oledzki, M

    1980-01-01

    This article presents the viewpoint of the Polish school of social policy of the Institute of Social Economy concerning the problem of optimization of demographic structures and processes in contemporary Poland. This school was created under the leadership of the outstanding sociologist Ludwik Krzywicki (1859-1941). The reasoning concerns, first of all, the scientific premises of the choice of criteria of demographic optimization examined and then there is a critical assessment of modern simplified approaches to the definition of optimum population. It also shows actual possibilities of demographic optimization and the complexity of analytical categories of socioeconomic processes which determine the development of the population in specific time and space. In conclusion, the theory of demographic optimization is regarded as a task too ambitious and perhaps even utopian in view of the assumptions needed for its satisfactory realization. This conclusion confirms the thesis contained in the handbook of demography by J.Z. Holzer published in 1970. The author considers, however, that the search for a theory of demographic optimization is still a task which mobilizes social sciences to an integration centered on demography and social policy. (author's)

  2. Identifying image preferences based on demographic attributes

    NASA Astrophysics Data System (ADS)

    Fedorovskaya, Elena A.; Lawrence, Daniel R.

    2014-02-01

    The intent of this study is to determine what sorts of images are considered more interesting by which demographic groups. Specifically, we attempt to identify images whose interestingness ratings are influenced by the demographic attribute of the viewer's gender. To that end, we use the data from an experiment where 18 participants (9 women and 9 men) rated several hundred images based on "visual interest" or preferences in viewing images. The images were selected to represent the consumer "photo-space" - typical categories of subject matter found in consumer photo collections. They were annotated using perceptual and semantic descriptors. In analyzing the image interestingness ratings, we apply a multivariate procedure known as forced classification, a feature of dual scaling, a discrete analogue of principal components analysis (similar to correspondence analysis). This particular analysis of ratings (i.e., ordered-choice or Likert) data enables the investigator to emphasize the effect of a specific item or collection of items. We focus on the influence of the demographic item of gender on the analysis, so that the solutions are essentially confined to subspaces spanned by the emphasized item. Using this technique, we can know definitively which images' ratings have been influenced by the demographic item of choice. Subsequently, images can be evaluated and linked, on one hand, to their perceptual and semantic descriptors, and, on the other hand, to the preferences associated with viewers' demographic attributes.

  3. [Syringomyelia and associated bone and joint diseases].

    PubMed

    Alnot, J-Y; Rossarie, R; Welby, F

    2007-05-01

    Syringomyelia can occur in patients presenting bone and joint diseases of various origins. When joint destruction of the shoulder or elbow produces little pain, a neurological cause might be involved. In this case, the disease history can be of utmost importance because an initial diagnosis of rheumatoid polyarthritis, polyosteoarthritis, or destructive joint disease can be misleading before the syringomyelic origin of the bone and joint disease becomes patent. We report two cases illustrating this association and the diagnostic pitfalls which can delay recognition of the syringomyelia. Better awareness of the prevalence of this condition should be helpful in establishing the diagnosis and in selecting patients who can benefit from neurosurgical treatment. The two cases presented here suggest that syringomyelia could be underdiagnosed in certain patients with an initially atypical presentation. A review of the current knowledge of syringomyelia suggests that arthroplasty is generally not advisable for destroyed dislocated syringomyelic joints.

  4. A Great War More Worthy Of Relation Than Any That Had Preceded It: Thucycides History of the Peloponnesian War as a Rosetta Stone for Joint Warfare and Operational Art

    DTIC Science & Technology

    2006-06-16

    wars long past as well as to those still reeking with the scent of battle .” General Douglas MacArthur 1935 Report to Sec of Army The...Joint Operations. The JMOHC uses the Battle of Vicksburg, the beaches of Inchon, and the sands of Operation DESERT STORM as case studies to... Battles , Cities, and Concepts of the Peloponnesian War. Naval War College, 2002, (NWC reprint) The Peloponnesian War was doctrinally illustrative

  5. Demographic rates and population viability of black bears in Louisiana

    USGS Publications Warehouse

    Laufenberg, Jared S.; Clark, Joseph D.; Hooker, Michael J.; Lowe, Carrie L.; O'Connell-Goode, Kaitlin C.; Troxler, Jesse C.; Davidson, Maria M.; Chamberlain, Michael J.; Chandler, Richard B.

    2015-01-01

    The Louisiana black bear (Ursus americanus luteolus) was reduced to a few small, fragmented, and isolated subpopulations in the Lower Mississippi Alluvial Valley by the mid-twentieth century resulting from loss and fragmentation of habitat. In 1992, the United States Fish and Wildlife Service (USFWS) granted the Louisiana black bear threatened status under the United States Endangered Species Act of 1973. Since that time, a recovery plan was developed, a reintroduced population was established, and habitat recovery has occurred. The Recovery Plan states that a minimum of 2 populations must be viable (i.e., persistence probabilities over 100 years >0.95), 1 in the Tensas River Basin and 1 in the Atchafalaya River Basin. Consequently, our objectives were to 1) estimate demographic rates of Louisiana black bear subpopulations, 2) develop data-driven stochastic population projection models, and 3) determine how different projection model assumptions affect population trajectories and predictions about long-term persistence. Our overall goal was to assess long-term persistence of the bear subpopulations in Louisiana, individually and as a whole. We collected data using varying combinations of non-invasive DNA sampling, live capture, winter den visits, and radio monitoring from 2002 to 2012 in the 4 areas currently supporting breeding subpopulations in Louisiana: Tensas River Basin (TRB), Upper Atchafalaya River Basin (UARB), Lower Atchafalaya River Basin (LARB), and a recently reintroduced population at the Three Rivers Complex (TRC). From 2002 to 2012, we radio monitored fates of 86 adult females within the TRB and 43 in the TRC. Mean estimates of annual adult survival for the TRB and TRC were 0.997 and 0.990, respectively, when unknown fates were assumed alive and 0.970 and 0.926 when unknown fates were assumed dead. From 2003 to 2013, we observed 130 cub litters from 74 females in the TRB, and 74 cub litters from 45 females in the TRC. During the same period, we

  6. Spacesuit mobility knee joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1979-01-01

    Pressure suit mobility joints are for use in interconnecting adjacent segments of an hermetically sealed spacesuit in which low torques, low leakage and a high degree of reliability are required. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics and includes linkages which restrain the joint from longitudinal distension and includes a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  7. Spacesuit mobility joints

    NASA Technical Reports Server (NTRS)

    Vykukal, H. C. (Inventor)

    1978-01-01

    Joints for use in interconnecting adjacent segments of an hermetically sealed spacesuit which have low torques, low leakage and a high degree of reliability are described. Each of the joints is a special purpose joint characterized by substantially constant volume and low torque characteristics. Linkages which restrain the joint from longitudinal distension and a flexible, substantially impermeable diaphragm of tubular configuration spanning the distance between pivotally supported annuli are featured. The diaphragms of selected joints include rolling convolutions for balancing the joints, while various joints include wedge-shaped sections which enhance the range of motion for the joints.

  8. Demographic and affective covariates of pain.

    PubMed

    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.

  9. Demographic change and carbon dioxide emissions.

    PubMed

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

    2012-07-14

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

  10. Estimating demographic parameters using a combination of known-fate and open N-mixture models

    USGS Publications Warehouse

    Schmidt, Joshua H.; Johnson, Devin S.; Lindberg, Mark S.; Adams, Layne G.

    2015-01-01

    Accurate estimates of demographic parameters are required to infer appropriate ecological relationships and inform management actions. Known-fate data from marked individuals are commonly used to estimate survival rates, whereas N-mixture models use count data from unmarked individuals to estimate multiple demographic parameters. However, a joint approach combining the strengths of both analytical tools has not been developed. Here we develop an integrated model combining known-fate and open N-mixture models, allowing the estimation of detection probability, recruitment, and the joint estimation of survival. We demonstrate our approach through both simulations and an applied example using four years of known-fate and pack count data for wolves (Canis lupus). Simulation results indicated that the integrated model reliably recovered parameters with no evidence of bias, and survival estimates were more precise under the joint model. Results from the applied example indicated that the marked sample of wolves was biased toward individuals with higher apparent survival rates than the unmarked pack mates, suggesting that joint estimates may be more representative of the overall population. Our integrated model is a practical approach for reducing bias while increasing precision and the amount of information gained from mark–resight data sets. We provide implementations in both the BUGS language and an R package.

  11. Estimating demographic parameters using a combination of known-fate and open N-mixture models.

    PubMed

    Schmidt, Joshua H; Johnson, Devin S; Lindberg, Mark S; Adams, Layne G

    2015-10-01

    Accurate estimates of demographic parameters are required to infer appropriate ecological relationships and inform management actions. Known-fate data from marked individuals are commonly used to estimate survival rates, whereas N-mixture models use count data from unmarked individuals to estimate multiple demographic parameters. However, a joint approach combining the strengths of both analytical tools has not been developed. Here we develop an integrated model combining known-fate and open N-mixture models, allowing the estimation of detection probability, recruitment, and the joint estimation of survival. We demonstrate our approach through both simulations and an applied example using four years of known-fate and pack count data for wolves (Canis lupus). Simulation results indicated that the integrated model reliably recovered parameters with no evidence of bias, and survival estimates were more precise under the joint model. Results from the applied example indicated that the marked sample of wolves was biased toward individuals with higher apparent survival rates than the unmarked pack mates, suggesting that joint estimates may be more representative of the overall population. Our integrated model is a practical approach for reducing bias while increasing precision and the amount of information gained from mark-resight data sets. We provide implementations in both the BUGS language and an R package.

  12. Demographic Challenges in America’s Future,

    DTIC Science & Technology

    1982-05-01

    of women are em- ployed, and if the opportunity cost of children is a sufficiently impor- tant factor in couples’ decisions, fertility rates may even...AD-A130 637 DEMOGRAPHIC CHALLENGES IN AMERICA’S FTTUREIU) RAND CORP / SANTA MONICA CA W ’P BUTZ ET AL. MAY 02 RAND/R 2911 RC seI-AD-E?5O 765...UNCLASSIFIED FIG 5/1 N OI liiie M~lD 1.0 4 *2.0 1111.25 lii I.4 . Ifln IIII~ - MICROCOPY RESOLUTION TEST CHART k&TONAL 9uREAU OF STAN0AROS -96 - A Demographic

  13. The demographic transition: model and reality.

    PubMed

    Alexandersson, G

    1981-01-01

    Observed exponential population growth curves are short-term parts of a logistic or S-curve in demography or a product-cycle curve in technology. All human populations have the ability to adjust their rates of growth, a fact recognized by the demographic transition model. The acceleration of world population growth that began after 1650 and became conspicuous after 1850 was largely confined to industrialized countries of European culture until after World War II, when the S-curve passed the inflection point. Many signs indicate that the decline in growth rates may become striking in the 1980s or 1990s. The demographic transition agrees with the logistic curve, and since the ultimate carrying capacity of the Earth is limited, represents an intelligent adaptation. The industrial countries with the longest statistical records, such as Sweden and Finland, evidence early efforts to control fertility. The demographic transition in Sweden lasted from 1815 to 1930 and occurred without government interference. A question for postindustrial western society is whether birth rates will be adjusted to the rising death rates expected as the population ages. Birth and death rates in most formulations of the demographic transition model are typical of Western Europe at the start of the transition process but are much too low for most countries of the world. Japan's demographic transition and that of several other Asian countries have occurred much more rapidly than those of Western Europe and have demonstrated not only that the demographic transition model was applicable but that the time span could be shortened by a factor of about 10 when government policy was substituted for spontaneous development. The Indian experience however shows that the shortening of the transition cannot be imposed from above. The demographic transition is well on its way in most of Asia and Latin America, but Africa and the Muslim countries of Asia have so far done little to restrain their high

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

    PubMed

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

    2003-12-01

    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.

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

    USGS Publications Warehouse

    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.

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

    PubMed Central

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

    2015-01-01

    INTRODUCTION This study aimed to describe the demographic, social, developmental and behavioural profile of children hospitalised for alleged child maltreatment syndrome (CMS). METHODS This study was a retrospective review of the consecutive inpatient records of children (0–16 years) admitted to the National University Hospital, Singapore, for alleged CMS over a three-year period. Descriptive data on the demographic characteristics, alleged maltreatment, medical and developmental histories, and family background of these children were collected and analysed. Chi-square statistics were used to test whether family factors were associated with the type of maltreatment and the presence of developmental disorders. RESULTS A total of 89 children, who accounted for 90 admission cases, were studied. Physical abuse (70.0%) was the most common, followed by neglect (11.1%) and sexual abuse (7.8%). Child protection services had already been involved in 29.2% of the cases prior to the child’s admission. Children who were victims of abuse were more likely to come from homes with a prior history of domestic violence (p = 0.028). Financial difficulty was found to be a risk factor for neglect (p = 0.005). Among the 89 children, 15.7% were found to have developmental disorders and 10.1% had mental health diagnoses. Children who had developmental disorders were more likely to have a parent with a mental health disorder (p = 0.002). CONCLUSION A sizeable proportion of the children admitted for alleged CMS had developmental or behavioural disorders. Clinicians have a role in ensuring that these children have appropriate follow-up plans. Children from high-risk families should be screened for maltreatment. PMID:26668405

  17. Population momentum across vertebrate life histories

    USGS Publications Warehouse

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

    2006-01-01

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

  18. Demographic Group Differences in Adolescents' Time Attitudes

    ERIC Educational Resources Information Center

    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…

  19. Understanding China's Demographic Dividends and Labor Issue

    ERIC Educational Resources Information Center

    Peng, Xizhe

    2013-01-01

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

  20. Life Potential as a Basic Demographic Indicator

    ERIC Educational Resources Information Center

    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…

  1. Demographic Trends Affecting the Future Labor Force.

    ERIC Educational Resources Information Center

    Taeuber, Karl E.

    This report reviews recent population and manpower projections and examines how they take into account certain unexpected shifts in demographic, social, and economic behavior. It also assesses how well the particular circumstances, trends, and problems of the nation's major minority groups have been brought into the purview of the projection…

  2. 5 CFR 841.404 - Demographic factors.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Demographic factors. 841.404 Section 841... factors. (a) The Office of Personnel Management (OPM) will consider the factors listed below in determining normal cost percentages. To the extent data are available for the factor by specific category...

  3. Human population growth and the demographic transition.

    PubMed

    Bongaarts, John

    2009-10-27

    The world and most regions and countries are experiencing unprecedentedly rapid demographic change. The most obvious example of this change is the huge expansion of human numbers: four billion have been added since 1950. Projections for the next half century expect a highly divergent world, with stagnation or potential decline in parts of the developed world and continued rapid growth in the least developed regions. Other demographic processes are also undergoing extraordinary change: women's fertility has dropped rapidly and life expectancy has risen to new highs. Past trends in fertility and mortality have led to very young populations in high fertility countries in the developing world and to increasingly older populations in the developed world. Contemporary societies are now at very different stages of their demographic transitions. This paper summarizes key trends in population size, fertility and mortality, and age structures during these transitions. The focus is on the century from 1950 to 2050, which covers the period of most rapid global demographic transformation.

  4. The Demographics of Corporal Punishment in Texas

    ERIC Educational Resources Information Center

    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…

  5. Complexity and demographic stability in population models.

    PubMed

    Demetrius, Lloyd; Gundlach, Volker Matthias; Ochs, Gunter

    2004-05-01

    This article is concerned with relating the stability of a population, as defined by the rate of decay of fluctuations induced by demographic stochasticity, with its heterogeneity in age-specific birth and death rates. We invoke the theory of large deviations to establish a fluctuation theorem: The demographic stability of a population is positively correlated with evolutionary entropy, a measure of the variability in the age of reproducing individuals in the population. This theorem is exploited to predict certain correlations between ecological constraints and evolutionary trends in demographic stability, namely, (i) bounded growth constraints--a uni-directional increase in stability, (ii) unbounded growth constraints (large population size)--a uni-directional decrease in stability, (iii) unbounded growth constraints (small population size)--random, non-directional change in stability. These principles relating ecological constraints with trends in demographic stability are shown to be far reaching generalizations of the tenets derived from classical studies of stability in an evolutionary context. These results thus provide a new conceptual framework for explaining patterns of variation in population numbers observed in natural populations.

  6. State Differences: The Key to Demographics.

    ERIC Educational Resources Information Center

    Hodgkinson, Harold

    1999-01-01

    This companion piece to a 1997 article examines United States demographic trends, such as diversity by age, "race" and U.S. Census racial classifications, wealth, transiency, suburbanization and sprawl, and immigration, focusing on differences among states and metro regions. Nothing, including achievement scores, social services, and…

  7. A Model for External Demographic Analysis.

    ERIC Educational Resources Information Center

    Hall, Barbara Ann

    A data-collection model is presented for the gathering of timely information on population demographic characteristics, as well as economic, educational, environmental, and social trends. First, the paper discusses the importance of anticipating internal and external changes and establishing priorities for resource allocation in the design of a…

  8. Demographic Factors Related to Enrollment Projections. Draft.

    ERIC Educational Resources Information Center

    Pitruzzello, Philip

    School districts must analyze demographic data carefully if they hope to deal effectively with changing enrollment patterns. Sources of relevant data include local planning boards, utility companies, government records of vital statistics, carefully conducted school censuses, and municipal records of housing construction and property transfers.…

  9. Some Demographic Correlates of Changing Newspaper Circulation.

    ERIC Educational Resources Information Center

    Eberhard, Wallace B.

    There are varied opinions on the relationship between the circulation penetration of the American daily newspapers and certain demographic indicators. Previous studies have treated the growth of circulation figures by utilizing gross national data and have indicated the role newspaper circulation plays in defining the limits of major urban…

  10. Psychological and Demographic Correlates of Career Patterns

    ERIC Educational Resources Information Center

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

    2009-01-01

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

  11. Demographic and Lifestyle Variables Associated with Obesity

    ERIC Educational Resources Information Center

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

    2010-01-01

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

  12. RHEUMATOID ARTHRITIS—Diagnosis in Peripheral Joint Affliction

    PubMed Central

    Mettier, Stacy R.

    1955-01-01

    The diagnosis of rheumatoid arthritis in a typical case depends upon a history of pain and swelling of various joints throughout the body. In the first stages the disease usually involves only the small joints of the hands and feet, but sooner or later it spreads to the larger joints. This may be accompanied by fibrosis of one or more joints, causing disability ranging from disuse of one joint up to total incapacity. Diagnosis in early or atypical cases is often impossible until the patient has been under observation a long time. It is important that diagnosis be made as early as possible, in order that appropriate therapy may be started and ankylosis and disability of the joints prevented. Since laboratory procedures and roentgen films do not show early changes, emphasis is placed on the history and physical examination for diagnosis. PMID:14351989

  13. Optimized Bolted Joint

    NASA Technical Reports Server (NTRS)

    Hart-Smith, L. J.; Bunin, B. L.; Watts, D. J.

    1986-01-01

    Computer technique aids joint optimization. Load-sharing between fasteners in multirow bolted composite joints computed by nonlinear-analysis computer program. Input to analysis was load-deflection data from 180 specimens tested as part of program to develop technology of structural joints for advanced transport aircraft. Bolt design optimization technique applicable to major joints in composite materials for primary and secondary structures and generally applicable for metal joints as well.

  14. Canadian History.

    ERIC Educational Resources Information Center

    School Libraries in Canada, 2003

    2003-01-01

    Includes 22 articles that address Canadian history and the importance of having students honor Canada's past by providing articles relating to the areas of History and Social Studies covering: historical fiction as instructional material; Canadian scientists; agricultural fairs; the Historical Foundation; social science books on Canada; student…

  15. History of the Space Radiation Effects (SPACERAD) Program for the joint USAF/NASA CRRES mission. Part 1. From the origins through the launch, 1981-1990. Interim report

    SciTech Connect

    Liebowitz, R.P.

    1992-03-16

    The history narrates the Space Radiation Effects (SPACERAD) Program from its origins in 1981 through the launch of the SPACERAD experiments on the USAF/NASA Combined Release/Radiation Effects Satellite (CRRES) on July 25, 1990 and the initial data results in October 1990. The SPACERAD Program comprised a coordinated schedule of space-and-ground testing of state-of-the-art microelectronics, together with new satellite measurements of the Earth's radiation belts. The goals for the program were to produce improved standards and procedures for ground-testing future space microelectronics and new dynamic models of the radiation belts. The history discusses programmatic, management and funding issues that arose in the course of its realization.

  16. Demographic variation in the U.K. serotine bat: filling gaps in knowledge for management

    PubMed Central

    Chauvenet, Alienor L M; Hutson, Anthony M; Smith, Graham C; Aegerter, James N

    2014-01-01

    Species of conservation concern, or those in conflict with man, are most efficiently managed with an understanding of their population dynamics. European bats exemplify the need for successful and cost-effective management for both reasons, often simultaneously. Across Europe, bats are protected, and the concept of Favourable Conservation Status (FCS) is used as a key tool for the assessment and licensing of disruptive actions to populations. However, for efficient decision-making, this assessment requires knowledge on the demographic rates and long-term dynamics of populations. We used capture–mark–recapture to describe demographic rates for the Serotine bat (Eptesicus serotinus) at two sites in England and investigate the transition rates between three stages: juveniles, immatures, and breeders. We then use these rates in an individual-based population dynamics model to investigate the expected trajectories for both populations. Our results demonstrate for the first time the presence and scale of temporal variation in this species' demography. We describe the lengthy prereproductive period (3.5 years) that female Serotines experience. Finally, we show how site-specific variation in demographic rates can produce divergent population trajectories. Effective management of European bat populations can be achieved through the understanding of life histories, and local demographic rates and population dynamics, in order to anticipate the presence of source and sink sites in the landscape. Using the Serotine bat in England, we show that these can be obtained from rigorous and systematic studies of long-term demographic datasets. PMID:25614796

  17. Population momentum across the demographic transition.

    PubMed

    Blue, Laura; Espenshade, Thomas J

    2011-01-01

    Population momentum is the main driver of global population growth today, and this makes an appreciation of momentum critical to understanding contemporary worldwide growth dynamics. This article traces population momentum along with two recently defined measures of momentum decomposed—stable and nonstable momentum—across the demographic transition. We use historical data and population projections from 16 countries to illustrate some previously ignored empirical regularities of the demographic transition in both the developed and the developing world. We also demonstrate the dynamic nature of stable and nonstable momentum, as changes in stable momentum lead to predictable changes in current and future nonstable momentum. These results suggest that momentum, which by definition is measured at a point in time, can also be considered as a process that unfolds over time.

  18. New Approaches to Demographic Data Collection

    PubMed Central

    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

  19. The spatial components of demographic change.

    PubMed

    Campisi, D

    1986-04-01

    "In recent years, fertility in developed countries has drastically fallen towards replacement levels, so that further changes play an increasing role in determining the dynamics of population systems. In this paper, the dynamics of multiregional populations are analyzed when occasional perturbations resulting from changes in social and economic conditions exist. A perturbation theory for population models is introduced and the increasing effect of changes in demographic rates in determining the spatial component of the multiregional population growth is shown." The author outlines the critical situations in which perturbations produce drastic demographic changes. Data for Italy are used to show the theory's usefulness in analyzing both short- and long-term effects of changes in vital rates.

  20. Global demographic trends and future carbon emissions.

    PubMed

    O'Neill, Brian C; Dalton, Michael; Fuchs, Regina; Jiang, Leiwen; Pachauri, Shonali; Zigova, Katarina

    2010-10-12

    Substantial changes in population size, age structure, and urbanization are expected in many parts of the world this century. Although such changes can affect energy use and greenhouse gas emissions, emissions scenario analyses have either left them out or treated them in a fragmentary or overly simplified manner. We carry out a comprehensive assessment of the implications of demographic change for global emissions of carbon dioxide. Using an energy-economic growth model that accounts for a range of demographic dynamics, we show that slowing population growth could provide 16-29% of the emissions reductions suggested to be necessary by 2050 to avoid dangerous climate change. We also find that aging and urbanization can substantially influence emissions in particular world regions.

  1. Global demographic trends and future carbon emissions

    PubMed Central

    O'Neill, Brian C.; Dalton, Michael; Fuchs, Regina; Jiang, Leiwen; Pachauri, Shonali; Zigova, Katarina

    2010-01-01

    Substantial changes in population size, age structure, and urbanization are expected in many parts of the world this century. Although such changes can affect energy use and greenhouse gas emissions, emissions scenario analyses have either left them out or treated them in a fragmentary or overly simplified manner. We carry out a comprehensive assessment of the implications of demographic change for global emissions of carbon dioxide. Using an energy–economic growth model that accounts for a range of demographic dynamics, we show that slowing population growth could provide 16–29% of the emissions reductions suggested to be necessary by 2050 to avoid dangerous climate change. We also find that aging and urbanization can substantially influence emissions in particular world regions. PMID:20937861

  2. Exoplanet Demographics with WFIRST-AFTA

    NASA Astrophysics Data System (ADS)

    Gaudi, B. S.; WFIRST-AFTA Science Definition Team

    2014-01-01

    Measurements of the demographics of exoplanets over a broad range of planet and host-star properties provide fundamental empirical constraints on theories of planet formation and evolution. Because of its unique sensitivity to low-mass, long-period, and free-floating planets, microlensing is an essential complement to our arsenal of planet detection methods. I outline the expected returns of a microlensing survey with WFIRST-AFTA. When combined with the results from complementary surveys such as Kepler, WFIRST-AFTA will yield a nearly complete picture of the demographics of planetary systems throughout the Galaxy, providing fundamental tests of planet formation theories, and informing our understanding of the frequency and potential habitability of low mass planets located in the habitable zones of their host stars.

  3. Demographic perspectives on Saudi Arabia's development.

    PubMed

    Looney, R E

    1985-06-01

    Demographic movements likely to be taking place in Saudi Arabia were hypothesized on the basis of general knowledge. The discussion reports on population size, general Arab demographic patterns, general determinants of fertility, Arab fertility patterns, Saudi fertility patterns, mortality in general, mortality in the Middle East, mortality in Saudi Arabia, Saudi Arabian population growth, immigration, the changing composition of the work force, and third plan targets. Some doubt exists as to the size of Saudi Arabia's population, but there is little question that the total is growing rapidly. This expansion is taking place through stepped up immigration and a relatively high natural growth of indigenous Saudis, but statistics on population size, structure, and on the number of births and deaths leaves the magnitude of a number of important demographic trends in doubt. Yet, considerable evidence exists that several of the Arab countries in the region with fairly good demographic data are likely to have similar demographic patterns. In depth analysis of the demographic dynamics of these countries, particularly Jordan and Kuwait, identified several common elements bearing on several key parameters. Using what Saudi data is available and making comparisons with these neighboring countries, one can, based on expected levels of birth and death rates, indirectly infer the natural growth of Saudi Arabia's population. With several notable exceptions, Saudi Arabia's demographic patterns show a marked similarity to those experienced in the region as a whole. The average rate of population growth in both Saudi Arabia and the Arab region is about 3% a year and in both instances fertility rates are high. The demographic structure of these countries is characterized by the youthfulness of the population. In most of the Arab countries, the population aged 15 years or under accounts for over 48% of the population. The rate of the economically active population is low, ranging from

  4. Evolving demographics of advanced dental education.

    PubMed

    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.

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

    PubMed

    Ananta, A

    1993-06-01

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

  6. Lethality and Autonomous Systems: The Roboticist Demographic

    DTIC Science & Technology

    2008-01-01

    humanoid (22%), and other (23%); 9) Media Influence: only 18% said that media had a strong or very strong influence on their attitude to robots ...and whether certain emotions would be appropriate in a military robot . The Wars question was worded as follows: To what extent do you think ...Lethality and Autonomous Systems: The Roboticist Demographic Lilia V. Moshkina and Ronald C. Arkin Mobile Robot Laboratory, College of

  7. Different Approaches to Monitoring Local Demographic Change,

    DTIC Science & Technology

    1982-05-01

    1.254 Franklin 1.150 1.131 Schoharie 1.253 1.141 Fulton 1.317 1.260 Schuyler 0.959 0.927 Genesee 1.028 0.990 Seneca 0.978 0.943 Greene 1.574 1.528...Goldsmith, Harold F., and Elizabeth L. Unger. 1973. Social Area Analysis: Procedures and Illustrative Application Based Upon the Mental Health Demographic

  8. Entropy Based Modelling for Estimating Demographic Trends.

    PubMed

    Li, Guoqi; Zhao, Daxuan; Xu, Yi; Kuo, Shyh-Hao; Xu, Hai-Yan; Hu, Nan; Zhao, Guangshe; Monterola, Christopher

    2015-01-01

    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.

  9. Rural Household Demographics, Livelihoods and the Environment

    PubMed Central

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

    2008-01-01

    This paper reviews and synthesizes findings from scholarly work on linkages among rural household demographics, livelihoods and the environment. Using the livelihood approach as an organizing framework, we examine evidence on the multiple pathways linking environmental variables and the following demographic variables: fertility, migration, morbidity and mortality, and lifecycles. Although the review draws on studies from the entire developing world, we find the majority of micro-level 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. PMID:19190718

  10. Intelligent system to study demographic evolution

    NASA Astrophysics Data System (ADS)

    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.

  11. Family History

    MedlinePlus

    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 ...

  12. Modeling of Human Joint Structures.

    DTIC Science & Technology

    1982-09-01

    Radial Lateral " epicondyle Olecranon Radius Ulna Figure 3. Lateral aspect of the right elbow joint. -17- Annular Ligament This strong band encircles... elbow joint, knee joint, human joints, shoulder joint, ankle joint, joint models, hip joint, ligaments. 20. ABSTRACT (Continue on reverse side If...ligaments. -A rather extended discussion of the articulations and anatomical descriptions of the elbow , shoulder, hip, knee and ankle joints are

  13. [The keys to the western demographic "miracle"].

    PubMed

    Burguiere, A

    1991-09-01

    Unlike most historical disciplines which had access to copious sources of data before refining their analytical methods, historical demography has almost simultaneously acquired data and developed rigorous analytical methods. French parish records did not attract detailed scrutiny until after World War II, but family reconstitution and other methods of exploitation were soon perfected. The continuing paradox of historical demography is that its statistical methods are rigorous but data remain sparse. Several dozen villages and a few cities have emerged from a vast obscurity but entire regions remain unexplored. Nonetheless, the study of preindustrial populations has progressed more in the past 20 years than has study of populations in the industrial era. Complex phenomena such as the fertility decline and incipient control of birth rates in late 18th century Europe have been studied or explained more adequately than has the inverse phenomenon, the baby boom of the 1940s. A major impetus to historical demography in Europe was the desire of demographers at the National Institute of Demographic Studies to understand Europe's fertility decline through knowledge of the mechanisms that initially caused it to occur. The diversity of apparent demographic models that have resulted from the works of historical demographers has caused various regional models to be proposed for France in the 17th and 18th centuries. It is clear from statistical analysis of available data that by the 18th century, fertility control was practiced by the mass of the French population, but the interpretation of this fact is problematic. The change in fertility behavior must reflect a deeper change in mentalities. The diffusion of contraception in the 18th century did not represent a transgression of the teachings of the Catholic Church as much as a change in attitudes toward life in which the future security of children was increasingly sought in education and improved living standards, and in

  14. Individual heterogeneity in life histories and eco-evolutionary dynamics.

    PubMed

    Vindenes, Yngvild; Langangen, Øystein

    2015-05-01

    Individual heterogeneity in life history shapes eco-evolutionary processes, and unobserved heterogeneity can affect demographic outputs characterising life history and population dynamical properties. Demographic frameworks like matrix models or integral projection models represent powerful approaches to disentangle mechanisms linking individual life histories and population-level processes. Recent developments have provided important steps towards their application to study eco-evolutionary dynamics, but so far individual heterogeneity has largely been ignored. Here, we present a general demographic framework that incorporates individual heterogeneity in a flexible way, by separating static and dynamic traits (discrete or continuous). First, we apply the framework to derive the consequences of ignoring heterogeneity for a range of widely used demographic outputs. A general conclusion is that besides the long-term growth rate lambda, all parameters can be affected. Second, we discuss how the framework can help advance current demographic models of eco-evolutionary dynamics, by incorporating individual heterogeneity. For both applications numerical examples are provided, including an empirical example for pike. For instance, we demonstrate that predicted demographic responses to climate warming can be reversed by increased heritability. We discuss how applications of this demographic framework incorporating individual heterogeneity can help answer key biological questions that require a detailed understanding of eco-evolutionary dynamics.

  15. Individual heterogeneity in life histories and eco-evolutionary dynamics

    PubMed Central

    Vindenes, Yngvild; Langangen, Øystein

    2015-01-01

    Individual heterogeneity in life history shapes eco-evolutionary processes, and unobserved heterogeneity can affect demographic outputs characterising life history and population dynamical properties. Demographic frameworks like matrix models or integral projection models represent powerful approaches to disentangle mechanisms linking individual life histories and population-level processes. Recent developments have provided important steps towards their application to study eco-evolutionary dynamics, but so far individual heterogeneity has largely been ignored. Here, we present a general demographic framework that incorporates individual heterogeneity in a flexible way, by separating static and dynamic traits (discrete or continuous). First, we apply the framework to derive the consequences of ignoring heterogeneity for a range of widely used demographic outputs. A general conclusion is that besides the long-term growth rate lambda, all parameters can be affected. Second, we discuss how the framework can help advance current demographic models of eco-evolutionary dynamics, by incorporating individual heterogeneity. For both applications numerical examples are provided, including an empirical example for pike. For instance, we demonstrate that predicted demographic responses to climate warming can be reversed by increased heritability. We discuss how applications of this demographic framework incorporating individual heterogeneity can help answer key biological questions that require a detailed understanding of eco-evolutionary dynamics. PMID:25807980

  16. Semiconstrained Distal Radioulnar Joint Prosthesis

    PubMed Central

    Savvidou, Christiana; Murphy, Erin; Mailhot, Emilie; Jacob, Shushan; Scheker, Luis R.

    2013-01-01

    Distal radioulnar joint (DRUJ) problems can occur as a result of joint instability, abutment, or incongruity. The DRUJ is a weight-bearing joint; the ulnar head is frequently excised either totally or partially, and in some cases it is fused, because of degenerative, rheumatoid, or posttraumatic arthritis. Articles about these procedures report the ability to pronate and supinate, but they rarely discuss grip strength, and even less do they address lifting capacity. We report the long term results of the first 35 patients who underwent total DRUJ arthroplasty with the Aptis DRUJ prosthesis after 5 years follow-up. Surgical indications were all causes of dysfunctional DRUJ (degenerative, posttraumatic, autoimmune, congenital). We recorded data for patient demographics, range of motion (ROM), strength, and lifting capacity of the operated and of the nonoperated extremity. Pain and functional assessments were also recorded. The Aptis DRUJ prosthesis, a bipolar self-stabilizing DRUJ endoprosthesis that restores forearm function, consists of a semiconstained and modular implant designed to replace the function of the ulnar head, the sigmoid notch of the radius, and the triangular fibrocartilage ligaments. The surgical technique is presented in detail. The majority of the patients regained adequate ROM and improved their strength and lifting capacity to the operated side. Pain and activities of daily living were improved. Twelve patients experienced complications, most commonly being extensor carpi ulnaris (ECU) tendinitis, ectopic bone formation, bone resorption with stem loosening, low-grade infection, and need for ball replacement. The Aptis total DRUJ replacement prosthesis is an alternative to salvage procedures that enables a full range of motion as well as the ability to grip and lift weights encountered in daily living activities. PMID:24436788

  17. One-year outcomes after minimally invasive sacroiliac joint fusion with a series of triangular implants: a multicenter, patient-level analysis

    PubMed Central

    Sachs, Donald; Capobianco, Robyn; Cher, Daniel; Holt, Timothy; Gundanna, Mukund; Graven, Timothy; Shamie, A Nick; Cummings, John

    2014-01-01

    Background Sacroiliac joint (SI) pain is an often-overlooked cause of lower-back pain, due in part to a lack of specific findings on radiographs and a symptom profile similar to other back-related disorders. A minimally invasive surgical (MIS) approach to SI joint fusion using a series of triangular, titanium plasma spray-coated implants has shown favorable outcomes in patients with SI joint pain refractory to conservative care. The aim of this study was to provide a multicenter experience of MIS SI joint fusion using a patient-level analysis. Patients and methods We report a patient-level analysis from 144 patients with a mean of 16 months postoperative follow-up. Demographic information, perioperative measures, complications, and clinical outcomes using a visual analog scale for pain were collected prospectively. Random-effects regression models were used to account for intersite variability. Results The mean age was 58 years, 71% of patients were female, and 62% had a history of lumbar spinal fusion. Mean (95% confidence interval [CI]) operative time was 73 minutes (25.4–118), blood loss was minimal, and hospital stay was 0.8 days (0.1–1.5). At follow-up, mean (95% CI) visual analog scale pain scores improved by 6.1 points (5.7–6.6). Substantial clinical benefit, defined as a decrease in pain by >2.5 points or a score of 3.5 or less, was achieved in 91.9% of patients (95% CI 83.9%–96.1%), and 96% (95% CI 86.3%–98.8%) of patients indicated they would have the same surgery again. Conclusion When conservative measures fail to relieve symptoms resulting from degeneration or disruption of the SI joint, MIS SI joint fusion using a series of triangular, porous, titanium plasma spray-coated implants is a safe and effective treatment option. PMID:25210479

  18. Progressive Damage Analysis of Bonded Composite Joints

    NASA Technical Reports Server (NTRS)

    Leone, Frank A., Jr.; Girolamo, Donato; Davila, Carlos G.

    2012-01-01

    The present work is related to the development and application of progressive damage modeling techniques to bonded joint technology. The joint designs studied in this work include a conventional composite splice joint and a NASA-patented durable redundant joint. Both designs involve honeycomb sandwich structures with carbon/epoxy facesheets joined using adhesively bonded doublers.Progressive damage modeling allows for the prediction of the initiation and evolution of damage within a structure. For structures that include multiple material systems, such as the joint designs under consideration, the number of potential failure mechanisms that must be accounted for drastically increases the complexity of the analyses. Potential failure mechanisms include fiber fracture, intraply matrix cracking, delamination, core crushing, adhesive failure, and their interactions. The bonded joints were modeled using highly parametric, explicitly solved finite element models, with damage modeling implemented via custom user-written subroutines. Each ply was discretely meshed using three-dimensional solid elements. Layers of cohesive elements were included between each ply to account for the possibility of delaminations and were used to model the adhesive layers forming the joint. Good correlation with experimental results was achieved both in terms of load-displacement history and the predicted failure mechanism(s).

  19. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... arthritis, or JRA), systemic lupus erythematosus (SLE), and Lyme disease. Joint aspiration is diagnostic but it also can ... Parents MORE ON THIS TOPIC Evaluate Your Child's Lyme Disease Risk Living With Lupus Bones, Muscles, and Joints ...

  20. Culture - joint fluid

    MedlinePlus

    Joint fluid culture ... fungi, or viruses grow. This is called a culture. If these germs are detected, other tests may ... is no special preparation needed for the lab culture. How to prepare for the removal of joint ...

  1. Temporomandibular Joint Dysfunction

    MedlinePlus

    The temporomandibular joint (TMJ) connects your jaw to the side of your head. When it works well, it enables you to ... For people with TMJ dysfunction, problems with the joint and muscles around it may cause Pain that ...

  2. Knee joint replacement

    MedlinePlus

    ... page: //medlineplus.gov/ency/article/002974.htm Knee joint replacement To use the sharing features on this page, please enable JavaScript. Knee joint replacement is a surgery to replace a knee ...

  3. Large displacement spherical joint

    DOEpatents

    Bieg, Lothar F.; Benavides, Gilbert L.

    2002-01-01

    A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

  4. Hip joint injection

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/007633.htm Hip joint injection To use the sharing features on this ... injection is a shot of medicine into the hip joint. The medicine helps relieve pain and inflammation. It ...

  5. DEMOGRAPHIC UNCERTAINTY IN ECOLOGICAL RISK ASSESSMENTS. (R825347)

    EPA Science Inventory

    We built a Ricker's model incorporating demographic stochasticity to simulate the effects of demographic uncertainty on responses of gray-tailed vole (Microtus canicaudus) populations to pesticide applications. We constructed models with mark-recapture data collected from populat...

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

    ERIC Educational Resources Information Center

    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…

  7. Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Arch & Chord Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie & Diagonal Brace Joint Detail; Chord, Panel Post, Tie & Crossbracing Joint Detail - Dunlapsville Covered Bridge, Spanning East Fork Whitewater River, Dunlapsville, Union County, IN

  8. Joint Enrollment Report, 2014

    ERIC Educational Resources Information Center

    Iowa Department of Education, 2014

    2014-01-01

    The Iowa Department of Education collects information on joint enrollment in Iowa's 15 community colleges. Jointly enrolled students are high school students enrolled in community college credit coursework. Most jointly enrolled students enroll through Senior Year Plus (SYP) programs such as Postsecondary Enrollment Options (PSEO) and concurrent…

  9. Joint Aspiration (Arthrocentesis)

    MedlinePlus

    ... Old Feeding Your 1- to 2-Year-Old Joint Aspiration (Arthrocentesis) KidsHealth > For Parents > Joint Aspiration (Arthrocentesis) Print A A A What's in ... español Aspiración articular (artrocentesis) What It Is A joint aspiration (arthrocentesis) is a test that involves withdrawing ( ...

  10. Demographic and Anthropometric Assessment of US Army Anthropometric Data Base

    DTIC Science & Technology

    1985-08-01

    demographics , because the demographic composition of the Army is influenced by many factors . Among these are: recruiting priorities, the state of the...34ST -I-BILAD TECHNICAL REPORT AD NATICK/TR-86/004 DEMOGRAPHIC AND ANTHROPOMETRIC ASSESSMENT OF US ARMY SANTHROPOMETRIC DATA BASE BY DTIC BRUCE...TITLE (and Subtitle) S. TYPE OF REPORT & PERIOD COVERED Demographic and Anthropometric Assessment of Interim Report, Task I, eSeptember 1984 - April

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

    PubMed

    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.

  12. Understanding and Using Demographic Data: Terms and Measures.

    ERIC Educational Resources Information Center

    Lilley, Stephen

    This publication provides program planners and others with information and analytical tools for using demographic data in program planning, implementation, and evaluation. The report reviews the importance of demographic data and their relevance to programs and proper implementation of laws, discusses the collection of demographic information by…

  13. Social Security Disability: Demographic and Economic Characteristics of New Beneficiaries.

    DTIC Science & Technology

    1988-01-01

    your offices, we are providing information on the demographic , health, and economic conditions of social security disability insurance program...new survey in a subsequent report. SSA conducted its New Beneficiary Survey between October and December 1982, collecting a wide range of demographic ...retired beneficiaries and the general population. DEMOGRAPHIC AND EMPLOYMENT CHARACTERISTICS The disabled beneficiaries surveyed consisted of

  14. Demographics and treatment of the American family.

    PubMed

    Jojic, Mirjana; Raj, Abita; Wilkins, Kerry; Treadwell, Robyn; Caussade-Rodriguez, Eduardo; Blum, Joshua

    2012-04-01

    There have been numerous changes to the US family over the past several decades. Traditional family roles have changed, and the conception of what Americans consider a 'family' has likewise shifted with differing societal views regarding gender, gender roles, race, and ethnicity. This review examines demographics of the American family as well as a number of family therapies that have been historically and are presently used to treat family problems. We expect that with the changes present in US society, family therapies will need to continue to be sensitive and adaptive to these shifts in order to be effective.

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

    PubMed

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

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

  16. Lunar History

    NASA Technical Reports Server (NTRS)

    Edmunson, Jennifer E.

    2009-01-01

    This section of the workshop describes the history of the moon, and offers explanations for the importance of understanding lunar history for engineers and users of lunar simulants. Included are summaries of the initial impact that is currently in favor as explaining the moon's formation, the crust generation, the creation of craters by impactors, the era of the lunar cataclysm, which some believe effected the evolution of life on earth, the nature of lunar impacts, crater morphology, which includes pictures of lunar craters that show the different types of craters, more recent events include effect of micrometeorites, solar wind, radiation and generation of agglutinates. Also included is a glossary of terms.

  17. Demographic and health surveys: a profile.

    PubMed

    Corsi, Daniel J; Neuman, Melissa; Finlay, Jocelyn E; Subramanian, S V

    2012-12-01

    Demographic and Health Surveys (DHS) are comparable nationally representative household surveys that have been conducted in more than 85 countries worldwide since 1984. The DHS were initially designed to expand on demographic, fertility and family planning data collected in the World Fertility Surveys and Contraceptive Prevalence Surveys, and continue to provide an important resource for the monitoring of vital statistics and population health indicators in low- and middle-income countries. The DHS collect a wide range of objective and self-reported data with a strong focus on indicators of fertility, reproductive health, maternal and child health, mortality, nutrition and self-reported health behaviours among adults. Key advantages of the DHS include high response rates, national coverage, high quality interviewer training, standardized data collection procedures across countries and consistent content over time, allowing comparability across populations cross-sectionally and over time. Data from DHS facilitate epidemiological research focused on monitoring of prevalence, trends and inequalities. A variety of robust observational data analysis methods have been used, including cross-sectional designs, repeated cross-sectional designs, spatial and multilevel analyses, intra-household designs and cross-comparative analyses. In this profile, we present an overview of the DHS along with an introduction to the potential scope for these data in contributing to the field of micro- and macro-epidemiology. DHS datasets are available for researchers through MEASURE DHS at www.measuredhs.com.

  18. Children with limb deficiencies: demographic characteristics.

    PubMed

    Al-Worikat, Abdel Fattah; Dameh, Walid

    2008-03-01

    The aim of this study is to determine the demographic data for amputations in children in relation of age, sex, level and cause of amputation. Data were collected from the records of amputees who attended the prosthetic clinic at the Royal Rehabilitation Center, King Hussein Medical Centre, Jordan, between 1 January 1995 and 31 December 2005. Demographic data (age, sex, level and cause of amputation) were analyzed. Some 120 children with different levels of amputation were included with mean age of 6.2 years. There were 64 (53.3%) males and 56 (46.7%) females. Male to female ratio was 1.15:1. The dominant level of amputation was trans-radial in 10 patients (15.62%) in the upper limb and trans-tibial in 18 patients (28.12%) in the lower limb. The dominant cause of amputation was congenital deficiency in 56 patients (46.67%) followed by trauma in 48 (40%). The results of this study presented greater similarities to others in the literature, congenital limb deficiency being the dominant cause of amputation in children. This study helps in planning the needs for materials and budgets for the treatment of amputee children in Jordan.

  19. Demographic Characteristics of World Class Jamaican Sprinters

    PubMed Central

    Irving, Rachael; Charlton, Vilma; Morrison, Errol; Facey, Aldeam; Buchanan, Oral

    2013-01-01

    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. PMID:24396303

  20. Household demographic determinants of Ebola epidemic risk.

    PubMed

    Adams, Ben

    2016-03-07

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

  1. Material Stock Demographics: Cars in Great Britain.

    PubMed

    Cabrera Serrenho, André; Allwood, Julian M

    2016-03-15

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

  2. Bulletproof History.

    ERIC Educational Resources Information Center

    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)

  3. Arguing History

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2013-01-01

    The history of science illustrates some exciting--and sometimes controversial--moments. Unfortunately, textbooks tend to focus on results in a scientific discipline and only occasionally showcase an interesting historical vignette, telling the story behind those results. Although required studies may leave teachers little classroom time for…

  4. Making History

    ERIC Educational Resources Information Center

    Shein, Esther

    2008-01-01

    Jennifer Dorman was in a fix. Teaching ninth-grade US history at Holicong Middle School in Doylestown, Pennsylvania, Dorman wanted to tap into her students' interest in creating "something of value not just for their teachers, but something they could share with other students and people." But that required something a conventional paper-based…

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

    PubMed Central

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

    2014-01-01

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

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

    PubMed

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

    2014-09-16

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

  7. History of San Marco

    NASA Technical Reports Server (NTRS)

    Caporale, A. J.

    1968-01-01

    A brief history is reported of the first San Marco project, a joint program of the United States and Italy. The Project was a three phase effort to investigate upper air density and associated ionosphere phenomena. The initial phase included the design and development of the spacecraft, the experiments, the launch complex, and a series of suborbital flights, from Wallops Island. The second phase, consisting of designing, fabricating, and testing a spacecraft for the first orbital mission, culminated in an orbital launch also from Wallops Island. The third phase consisted of further refining the experiments and spacecraft instrumentation and of establishing a full-bore scout complex in Kenya. The launch of San Marco B, in April 1967, from this complex into an equatorial orbit, concluded the initial San Marco effort.

  8. Study methods, recruitment, socio-demographic findings and demographic representativeness in the OPPERA study

    PubMed Central

    Slade, Gary D.; Bair, Eric; By, Kunthel; Mulkey, Flora; Baraian, Cristina; Rothwell, Rebecca; Reynolds, Maria; Miller, Vanessa; Gonzalez, Yoly; Gordon, Sharon; Ribeiro-Dasilva, Margarete; Lim, Pei Feng; Greenspan, Joel D; Dubner, Ron; Fillingim, Roger B; Diatchenko, Luda; Maixner, William; Dampier, Dawn; Knott, Charles; Ohrbach, Richard

    2011-01-01

    This paper describes methods used in the project “Orofacial Pain Prospective Evaluation and Risk Assessment” (OPPERA) and evaluates socio-demographic characteristics associated with temporomandibular disorders (TMD) in the OPPERA case-control study. Representativeness was investigated by comparing socio-demographic profiles of OPPERA participants with population census profiles of counties near study sites and by comparing age- and gender-associations with TMD in OPPERA and the 2007-09 US National Health Interview Survey. Volunteers aged 18-44 years were recruited at four US study sites: 3,263 people without TMD were enrolled into the prospective cohort study; 1,633 of them were selected as controls for the baseline case-control study. Cases were 185 volunteers with examiner-classified TMD. Distributions of some demographic characteristics among OPPERA participants differed from census profiles, although there was less difference in socio-economic profiles. Odds of TMD was associated with greater age in this 18-44 year range; females had three times the odds of TMD as males; and relative to non-Hispanic-Whites, other racial groups had one-fifth the odds of TMD. Age- and gender-associations with chronic TMD were strikingly similar to associations observed in the US population. Assessments of representativeness in this demographically diverse group of community volunteers suggest that OPPERA case-control findings have good internal validity. PMID:22074749

  9. Demographics: Diversity in More Forms. Student Demographics, Now and the Future.

    ERIC Educational Resources Information Center

    Windham, Patricia; And Others

    While demographic diversity among the student body has increased substantially over the past several decades, the academic, economic, and social diversity of students will play a greater part in upcoming staffing and faculty requirements at community colleges. Data from Tallahassee Community College (TCC), in Florida, from 1980 to 1994 indicate…

  10. Kentucky Demographics: Demographic and Economic Impacts of Migration in Kentucky, 1975-80. No. 11.

    ERIC Educational Resources Information Center

    Price, Michael

    This analysis of demographic and economic impacts of migration compared samples of nonmigrants, inmigrants, and outmigrants for Kentucky from 1975 to 1980. Age, gender, race, birth place, educational attainment, income, and labor force characteristics were compared for the three groups. Inmigrants, including intrastate migrants, were compared on…

  11. Independent Demographic Responses to Climate Change among Temperate and Tropical Milksnakes (Colubridae: Genus Lampropeltis)

    PubMed Central

    Ruane, Sara; Torres-Carvajal, Omar; Burbrink, Frank T.

    2015-01-01

    The effects of Late Quaternary climate change have been examined for many temperate New World taxa, but the impact of Pleistocene glacial cycles on Neotropical taxa is less well understood, specifically with respect to changes in population demography. Here, we examine historical demographic trends for six species of milksnake with representatives in both the temperate and tropical Americas to determine if species share responses to climate change as a taxon or by area (i.e., temperate versus tropical environments). Using a multilocus dataset, we test for the demographic signature of population expansion and decline using non-genealogical summary statistics, as well as coalescent-based methods. In addition, we determine whether range sizes are correlated with effective population sizes for milksnakes. Results indicate that there are no identifiable trends with respect to demographic response based on location, and that species responded to changing climates independently, with tropical taxa showing greater instability. There is also no correlation between range size and effective population size, with the largest population size belonging to the species with the smallest geographic distribution. Our study highlights the importance of not generalizing the demographic histories of taxa by region and further illustrates that the New World tropics may not have been a stable refuge during the Pleistocene. PMID:26083467

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

    PubMed

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

    2013-12-01

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

  13. Genetic stratigraphy of key demographic events in Arabia.

    PubMed

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

    2015-01-01

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

  14. Genetic Stratigraphy of Key Demographic Events in Arabia

    PubMed Central

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

    2015-01-01

    At the crossroads between Africa and Eurasia, Arabia is necessarily a melting pot, its peoples enriched by successive gene flow over the generations. Estimating the timing and impact of these multiple migrations are important steps in reconstructing the key demographic events in the human history. However, current methods based on genome-wide information identify admixture events inefficiently, tending to estimate only the more recent ages, as here in the case of admixture events across the Red Sea (∼8–37 generations for African input into Arabia, and 30–90 generations for “back-to-Africa” migrations). An mtDNA-based founder analysis, corroborated by detailed analysis of the whole-mtDNA genome, affords an alternative means by which to identify, date and quantify multiple migration events at greater time depths, across the full range of modern human history, albeit for the maternal line of descent only. In Arabia, this approach enables us to infer several major pulses of dispersal between the Near East and Arabia, most likely via the Gulf corridor. Although some relict lineages survive in Arabia from the time of the out-of-Africa dispersal, 60 ka, the major episodes in the peopling of the Peninsula took place from north to south in the Late Glacial and, to a lesser extent, the immediate post-glacial/Neolithic. Exchanges across the Red Sea were mainly due to the Arab slave trade and maritime dominance (from ∼2.5 ka to very recent times), but had already begun by the early Holocene, fuelled by the establishment of maritime networks since ∼8 ka. The main “back-to-Africa” migrations, again undetected by genome-wide dating analyses, occurred in the Late Glacial period for introductions into eastern Africa, whilst the Neolithic was more significant for migrations towards North Africa. PMID:25738654

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

    PubMed

    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.

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

    PubMed

    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.

  17. How well can body size represent effects of the environment on demographic rates? Disentangling correlated explanatory variables.

    PubMed

    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.

  18. Demographics of the Short Period Comets

    NASA Astrophysics Data System (ADS)

    Grav, Tommy; Spahr, T.; Pan-STARRS Moving Object Processing Team

    2008-09-01

    The demographics of the short period comets is not very well understood. In order to create an accurate synthetic population of object to be used in the testing and prediction of the efficiency of the upcoming Pan-STARRS project, we have used two years of minor planet observations reported by the LINEAR survey to construct a model of the underlying cometary population. We find that the known population of Jupiter family comets are the visible portion of two populations, one with aphelia at Jupiter and another with aphelia at Saturn. Furthermore the population of small short period comets is found to be larger than previously thought. In this talk we present the synthetic model and its implication and prospects for science with Pan-STARRS and LSST.

  19. Fire victims: medical outcomes and demographic characteristics.

    PubMed Central

    Levine, M S; Radford, E P

    1977-01-01

    The medical outcomes and demographic characteristics of all victims of fires identified by The Baltimore Fire Department during a 14-month period in Baltimore City were studied. Fifty-nine per cent of victims suffered minor injuries, 25 per cent required hospitalization and 16 per cent were fatalities. The majority of survivable injuries were due to burns, while the majority of deaths were due to pulmonary injury and carbon monoxide intoxication. Deaths occurring at the scene of the fire or during the first 24 hours were predominantly due to carbon monoxide. Exposure to fires was more likely to result in deaths in the very young and very old. Evidence from autopsy protocols suggests that alcohol was a contributory factor. PMID:911020

  20. Demographic variation in nutrition knowledge in England

    PubMed Central

    Parmenter, K.; Waller, J.; Wardle, J.

    2000-01-01

    This paper describes a nutrition knowledge survey carried out on a cross-section of the adult population of England (n = 1040), looking at knowledge relating to current dietary recommendations, sources of nutrients, healthy food choices and diet–disease links. Serious gaps in knowledge about even the basic recommendations were discovered, and there was much confusion over the relationship between diet and disease. Significant differences in knowledge between socio-demographic groups were found, with men having poorer knowledge than women, and knowledge declining with lower educational level and socio-economic status. Possible reasons for these differences and implications for public education campaigns and socio-economic inequalities in health are discussed. PMID:10751375

  1. 3D face analysis for demographic biometrics

    SciTech Connect

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

    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.

  2. Demographic group differences in adolescents' time attitudes.

    PubMed

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

    2013-04-01

    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 Americans and Asian Americans reported higher scores for negative time attitudes and lower scores for positive time attitudes than European Americans and Latinos, with medium sizes. Adolescents in the low socioeconomic status group reported a less favorable evaluation of their past than middle and high SES peers, but there were no meaningful differences in time attitudes by gender. Findings indicate that middle SES adolescents, high school juniors and seniors, Latinos, and European Americans had higher representation in positive time attitude clusters (i.e., Positives and Balanced) than high SES adolescents, high school freshmen and sophomores, and African Americans.

  3. The Demographics of Women in Astronomy

    NASA Astrophysics Data System (ADS)

    Urry, M.; Marvel, K. B.; Blacker, B.

    1999-12-01

    To assess the status of women in astronomy we need data. How many women are astronomers? How does this percentage change with professional level? Do women have an advantage over men in hiring or other professional opportunities, or do men have the advantage, or is the playing field level? Using recent STScI and AAS surveys, I report the gender demographics in U.S. astronomy departments in 1999. Roughly 1/4 of astronomy graduate students are women, and this percentage decreases with rank, to 6% at the full professor level. Comparing to similar data from 1992, it appears that women fall behind men at the first transition, from graduate student to postdoc, but then keep pace with men in moving to faculty positions. (There is no sign that women advance more easily than men.) Interestingly, the percentage of women is slighly higher in the larger, better known institutions than in the profession as a whole.

  4. River history.

    PubMed

    Vita-Finzi, Claudio

    2012-05-13

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

  5. Demographic patterns and sustainable development in Ghana.

    PubMed

    Tawiah, E O

    1995-01-01

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

  6. Sacroiliac joint pain.

    PubMed

    Dreyfuss, Paul; Dreyer, Susan J; Cole, Andrew; Mayo, Keith

    2004-01-01

    The sacroiliac joint is a source of pain in the lower back and buttocks in approximately 15% of the population. Diagnosing sacroiliac joint-mediated pain is difficult because the presenting complaints are similar to those of other causes of back pain. Patients with sacroiliac joint-mediated pain rarely report pain above L5; most localize their pain to the area around the posterior superior iliac spine. Radiographic and laboratory tests primarily help exclude other sources of low back pain. Magnetic resonance imaging, computed tomography, and bone scans of the sacroiliac joint cannot reliably determine whether the joint is the source of the pain. Controlled analgesic injections of the sacroiliac joint are the most important tool in the diagnosis. Treatment modalities include medications, physical therapy, bracing, manual therapy, injections, radiofrequency denervation, and arthrodesis; however, no published prospective data compare the efficacy of these modalities.

  7. Acromioclavicular Joint Separations

    DTIC Science & Technology

    2013-01-01

    non-surgical measures, high-grade inju- ries frequently warrant surgical intervention to minimize pain and maximize shoulder function. Factors such as...sports [1–3]. While most injuries can be managed non-operatively, high-grade separations may result in per- sistent pain or functional decline and...joint pathology (cross arm adduction and loading of the AC joint) can be helpful to localize shoulder pain to the AC joint. These tests are especial- ly

  8. Joint Program Management Handbook

    DTIC Science & Technology

    1994-12-01

    the Engieermg and Manufacuring Devopment Phase. Nfilestoae HI- Develommen Annros Devopment approval marks a significant step for any program, but it is...to review concept formulaton. Systems Engilneertn As with service programs, systems engineering in joint program management is an essential tool . I...MANAGEMENT HANDBOOK On=e wd Umawtaiutt As discussed in Chapter 7, systems analysis of relationships is a usef tool for joint program managers. The joint

  9. Naturally rare versus newly rare: demographic inferences on two timescales inform conservation of Galápagos giant tortoises.

    PubMed

    Garrick, Ryan C; Kajdacsi, Brittney; Russello, Michael A; Benavides, Edgar; Hyseni, Chaz; Gibbs, James P; Tapia, Washington; Caccone, Adalgisa

    2015-02-01

    Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (N e ) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galápagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ∽100 generations, ∽2500 years) and deep (pre-Holocene, >10 thousand years ago) timescales. At the deep timescale, three populations showed strong signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical N e of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary N e were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, N e generally represented ∽0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this distinction

  10. Naturally rare versus newly rare: demographic inferences on two timescales inform conservation of Galápagos giant tortoises

    PubMed Central

    Garrick, Ryan C; Kajdacsi, Brittney; Russello, Michael A; Benavides, Edgar; Hyseni, Chaz; Gibbs, James P; Tapia, Washington; Caccone, Adalgisa

    2015-01-01

    Long-term population history can influence the genetic effects of recent bottlenecks. Therefore, for threatened or endangered species, an understanding of the past is relevant when formulating conservation strategies. Levels of variation at neutral markers have been useful for estimating local effective population sizes (Ne) and inferring whether population sizes increased or decreased over time. Furthermore, analyses of genotypic, allelic frequency, and phylogenetic information can potentially be used to separate historical from recent demographic changes. For 15 populations of Galápagos giant tortoises (Chelonoidis sp.), we used 12 microsatellite loci and DNA sequences from the mitochondrial control region and a nuclear intron, to reconstruct demographic history on shallow (past ∽100 generations, ∽2500 years) and deep (pre-Holocene, >10 thousand years ago) timescales. At the deep timescale, three populations showed strong signals of growth, but with different magnitudes and timing, indicating different underlying causes. Furthermore, estimated historical Ne of populations across the archipelago showed no correlation with island age or size, underscoring the complexity of predicting demographic history a priori. At the shallow timescale, all populations carried some signature of a genetic bottleneck, and for 12 populations, point estimates of contemporary Ne were very small (i.e., < 50). On the basis of the comparison of these genetic estimates with published census size data, Ne generally represented ∽0.16 of the census size. However, the variance in this ratio across populations was considerable. Overall, our data suggest that idiosyncratic and geographically localized forces shaped the demographic history of tortoise populations. Furthermore, from a conservation perspective, the separation of demographic events occurring on shallow versus deep timescales permits the identification of naturally rare versus newly rare populations; this distinction should

  11. Infected shoulder joint with loose Suture Anchor in the joint after Bankart’s Repair- A Case Report

    PubMed Central

    Kumar, Mukesh; Thilak, Jai

    2016-01-01

    Introduction: The glenoid labrum is frequently torn in traumatic glenohumeral dislocation; arthroscopic repair is the standard method of treatment. The complications associated with this repair are pulling out of metal suture anchors, chondrolysis and joint infection. The infection of joint after arthroscopy is less than 1%. Staphylococcus is most common organism and rarely followed by Pseudomonas aeruginosa. We report a case of infected shoulder with chondrolysis of the joint and pulled out metal suture anchor lying inside the joint after Bankart’s repair. Case Report: A 22-year-old gentleman came to us with complaints of shoulder joint pain & gross restriction of movements for one year, with history of intermittent fever and treatment in nearby hospital. He also gives past history of recurrent dislocation of shoulder with last episode 18 months back, which was diagnosed as Bankart’s lesion and arthroscopic Bankart’s repair was done 15 months back. He was evaluated at our institute and suspected to have infection of shoulder joint with pulled out metal suture anchor inside the joint. Arthroscopic removal of suture anchor and debridement of shoulder joint was done, Culture was obtained and culture specific antibiotics were given for six weeks, and significant improvement was observed with this line of treatment. At lyear follow up, the patient was able to perform his daily activities with terminal restriction of range of motion. Conclusions: Shoulder joint infection is rare after Bankart’s repair and required a high degree of suspicion. Any foreign materials inside the joint should be taken out & followed with aggressive treatment by debridement, irrigation and culture specific antibiotics. Suppression of joint infection with antibiotics should be avoided specially when there is foreign body inside the joint. PMID:27703928

  12. [Chronic knee joint discomfort].

    PubMed

    Wittke, R

    2005-06-23

    Chronic pain in the knee joint is frequently a sign of arthrosis in adults. This must be clearly differentiated from other knee problems. Patellofemoral stress syndrome (occurs mostly in young people) and arthritis with effusion in the knee joint after long and mostly unusual stress also allow only a reduced function of the knee joint. However, even when the knee joint is still fully functional, chronic problems could already exist: For example, for joggers, iliotibial band friction syndrome (runner's knee) or after high unphysiological stress, patellar tendinopathy (jumper's knee). These must be differentiated from pes anserinus syndrome and a plica mediopatellaris.

  13. The Diagnosis of Periprosthetic Joint Infection.

    PubMed

    Springer, Bryan D

    2015-06-01

    Periprosthetic joint infection remains one of the most common failure modes following total hip and total knee arthroplasty. As such, a systematic and cost effective approach to the evaluation and work-up of a patient with a suspected periprosthetic joint infection should be undertaken in every patient with a painful total joint. Although we have many diagnostic tools, a history and physical remain the most important. Many of the current laboratory tests are indirect measure of infection, lack specificity for diagnosis of infection, but serve as sensitive and cost effective screening tools. In addition, a new definition of periprosthetic infection helps to standardize the diagnosis. Biomarkers hold the promise of improved specificity and are becoming increasingly popular as a diagnostic tool.

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

    PubMed

    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."

  15. Demographic variation across successional stages and their effects on the population dynamics of the neotropical palm Euterpe precatoria.

    PubMed

    Otárola, Mauricio Fernández; Avalos, Gerardo

    2014-06-01

    • Premise of the study: Environmental heterogeneity is a strong selective force shaping adaptation and population dynamics across temporal and spatial scales. Natural and anthropogenic gradients influence the variation of environmental and biotic factors, which determine population demography and dynamics. Successional gradients are expected to influence demographic parameters, but the relationship between these gradients and the species life history, habitat requirements, and degree of variation in demographic traits remains elusive.• Methods: We used the palm Euterpe precatoria to test the effect of successional stage on plant demography within a continuous population. We calculated demographic parameters for size stages and performed matrix analyses to investigate the demographic variation within primary and secondary forests of La Selva, Costa Rica.• Key results: We observed differences in mortality and recruitment of small juveniles between primary and secondary forests. Matrix models described satisfactorily the chronosequence of population changes, which were characterized by high population growth rate in disturbed areas, and decreased growth rate in old successional forests until reaching stability.• Conclusions: Different demographic parameters can be expressed in contiguous subpopulations along a gradient of successional stages with important consequences for population dynamics. Demographic variation superimposed on these gradients contributes to generate subpopulations with different demographic composition, density, and ecological properties. Therefore, the effects of spatial variation must be reconsidered in the design of demographic analyses of tropical palms, which are prime examples of subtle local adaptation. These considerations are crucial in the implementation of management plans for palm species within spatially complex and heterogeneous tropical landscapes.

  16. Uncovering History for Future History Teachers

    ERIC Educational Resources Information Center

    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…

  17. Do Joint Fighter Programs Save Money?

    DTIC Science & Technology

    2013-01-01

    genesis of the Joint Strike Fighter (JSF) program. William Suit, Headquarters AFMC History Office, searched through vast amounts of primary source...appreciated. We also owe a special debt of gratitude to our project monitor, Dr.  Ross Jackson, Deputy Division Chief, Studies and Analyses Division... William Lucyshyn, and Michael Arendt, Competition in Defense Acquisitions, College Park, Md.: University of Maryland Center for Public Policy and

  18. Mechanics of Sheeting Joints

    NASA Astrophysics Data System (ADS)

    Martel, S. J.

    2015-12-01

    Physical breakdown of rock across a broad scale spectrum involves fracturing. In many areas large fractures develop near the topographic surface, with sheeting joints being among the most impressive. Sheeting joints share many geometric, textural, and kinematic features with other joints (opening-mode fractures) but differ in that they are (a) discernibly curved, (b) open near the topographic surface, and (c) form subparallel to the topographic surface. Where sheeting joints are geologically young, the surface-parallel compressive stresses are typically several MPa or greater. Sheeting joints are best developed beneath domes, ridges, and saddles; they also are reported, albeit rarely, beneath valleys or bowls. A mechanism that accounts for all these associations has been sought for more than a century: neither erosion of overburden nor high lateral compressive stresses alone suffices. Sheeting joints are not accounted for by Mohr-Coulomb shear failure criteria. Principles of linear elastic fracture mechanics, together with the mechanical effect of a curved topographic surface, do provide a basis for understanding sheeting joint growth and the pattern sheeting joints form. Compressive stresses parallel to a singly or doubly convex topographic surface induce a tensile stress perpendicular to the surface at shallow depths; in some cases this alone could overcome the weight of overburden to open sheeting joints. If regional horizontal compressive stresses, augmented by thermal stresses, are an order of magnitude or so greater than a characteristic vertical stress that scales with topographic amplitude, then topographic stress perturbations can cause sheeting joints to open near the top of a ridge. This topographic effect can be augmented by pressure within sheeting joints arising from water, ice, or salt. Water pressure could be particularly important in helping drive sheeting joints downslope beneath valleys. Once sheeting joints have formed, the rock sheets between

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

    PubMed Central

    Bode, Michael; Williamson, David H.; Weeks, Rebecca; Jones, Geoff P.; Almany, Glenn R.; Harrison, Hugo B.; Hopf, Jess K.; Pressey, Robert L.

    2016-01-01

    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 difficult to

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

    PubMed

    Bode, Michael; Williamson, David H; Weeks, Rebecca; Jones, Geoff P; Almany, Glenn R; Harrison, Hugo B; Hopf, Jess K; Pressey, Robert L

    2016-01-01

    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 difficult to

  1. The Impact of Educational Interventions by Socio-Demographic Attribute

    DTIC Science & Technology

    2008-07-10

    The Impact of Educational Interventions by Socio- Demographic Attribute Brian R. Hirshman, Michael Martin, Michael W. Bigrigg and...The Impact of Educational Interventions by Socio- Demographic Attribute 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S...mechanisms have been added to Construct, and these attributes have been tied to socio- demographic sub-populations, it is now possible to examine the effects

  2. The Changing Demographic Profile of the United States

    DTIC Science & Technology

    2006-05-05

    Demographic Profile of the United States Updated May 5, 2006 Laura B. Shrestha Specialist in Demography Domestic Social Policy Division Report...TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE The Changing Demographic Profile of the United States 5a. CONTRACT NUMBER 5b. GRANT...unclassified c. THIS PAGE unclassified Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 The Changing Demographic Profile of the United

  3. Behavioral, Psychological, and Demographic Predictors of Physical Fitness.

    DTIC Science & Technology

    1987-12-14

    psychological factors related to beliefs about fitness and weight control, and background/ demographic factors . These findings represent a successful attempt to...7AD-A192 697 BEHAVIORAL PSYCHOLOGICAL AND DEMOGRAPHIC PREDICTORS OF j PHYSICAL FITNESS(U) NAVAL HEALTH RESEARCH CENTER SAN DIEGO CA T L CONW~AY 1.4...DEC 87 NHRC-87-37 UNCLASSIFIED F/G 6/ie NL Illll i 11 .0 14w -W -- - -JCFILE Copy BEHAVIORALF PSYCHOLOGICAL, AND DEMOGRAPHIC - PREDICTORS OPPHYSICAL

  4. A Comparison of Breast Cancer Treatment Regimens by Demographic Characteristics

    DTIC Science & Technology

    1998-10-01

    Cancer Treatment Regimens by Demographic Characteristics PRINCIPAL INVESTIGATOR: Marianne E. Ulcickas Yood, M.P.H. CONTRACTING ORGANIZATION: Henry...NUMBERS A Comparison of Breast Cancer Treatment Regimens by Demographic Characteristics DAMD17-97-1-7302 6. AUTHOR(S) Marianne E. Ulcickas Yood, M.P.H. 7... Cancer Treatment Regimens by Demographic Characteristics (DAMD17-97-1-7302), Annual Report October, 1998 TABLE OF CONTENTS Introduction

  5. The value of age and medical history for predicting colorectal cancer and adenomas in people referred for colonoscopy

    PubMed Central

    2011-01-01

    Background Colonoscopy is an invasive and costly procedure with a risk of serious complications. It would therefore be useful to prioritise colonoscopies by identifying people at higher risk of either cancer or premalignant adenomas. The aim of this study is to assess a model that identifies people with colorectal cancer, advanced, large and small adenomas. Methods Patients seen by gastroenterologists and colorectal surgeons between April 2004 and December 2006 completed a validated, structured self-administered questionnaire prior to colonoscopy. Information was collected on symptoms, demographics and medical history. Multinomial logistic regression was used to simultaneously assess factors associated with findings on colonoscopy of cancer, advanced adenomas and adenomas sized 6 -9 mm, and ≤ 5 mm. The area under the curve of ROC curve was used to assess the incremental gain of adding demographic variables, medical history and symptoms (in that order) to a base model that included only age. Results Sociodemographic variables, medical history and symptoms (from 8,204 patients) jointly provide good discrimination between colorectal cancer and no abnormality (AUC 0.83), but discriminate less well between adenomas and no abnormality (AUC advanced adenoma 0.70; other adenomas 0.67). Age is the dominant risk factor for cancer and adenomas of all sizes. Having a colonoscopy within the last 10 years confers protection for cancers and advanced adenomas. Conclusions Our models provide guidance about which factors can assist in identifying people at higher risk of disease using easily elicited information. This would allow colonoscopy to be prioritised for those for whom it would be of most benefit. PMID:21899773

  6. Enforcement and Compliance History Online | US EPA

    EPA Pesticide Factsheets

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

  7. Health & Demographic Surveillance System Profile: The Nairobi Urban Health and Demographic Surveillance System (NUHDSS).

    PubMed

    Beguy, Donatien; Elung'ata, Patricia; Mberu, Blessing; Oduor, Clement; Wamukoya, Marylene; Nganyi, Bonface; Ezeh, Alex

    2015-04-01

    The Nairobi Urban Health and Demographic Surveillance System (NUHDSS) was the first urban-based longitudinal health and demographic surveillance platform in sub-Saharan Africa (SSA). The NUHDSS was established in 2002 to provide a platform to investigate the long-term social, economic and health consequences of urban residence, and to serve as a primary research tool for intervention and impact evaluation studies focusing on the needs of the urban poor in SSA. Since its inception, the NUHDSS has successfully followed every year a population of about 65,000 individuals in 24,000 households in two slum communities--Korogocho and Viwandani--in Nairobi, Kenya. Data collected include key demographic and health information (births, deaths including verbal autopsy, in- and out-migration, immunization) and other information that characterizes living conditions in the slums (livelihood opportunities, household amenities and possessions, type of housing etc.). In addition to the routine data, it has provided a robust platform for nesting several studies examining the challenges of rapid urbanization in SSA and associated health and poverty dynamics. NUHDSS data are shared through internal and external collaborations, in accordance with the Centre's guidelines for publications, data sharing.

  8. Health & Demographic Surveillance System Profile: Farafenni Health and Demographic Surveillance System in The Gambia.

    PubMed

    Jasseh, Momodou; Gomez, Pierre; Greenwood, Brian M; Howie, Stephen R C; Scott, Susana; Snell, Paul C; Bojang, Kalifa; Cham, Mamady; Corrah, Tumani; D'Alessandro, Umberto

    2015-06-01

    The Farafenni Health and Demographic Surveillance System (Farafenni HDSS) is located 170 km from the coast in a rural area of The Gambia, north of the River Gambia. It was set up in 1981 by the UK Medical Research Council Laboratories to generate demographic and health information required for the evaluation of a village-based, primary health care programme in 40 villages. Regular updates of demographic events and residency status have subsequently been conducted every 4 months. The surveillance area was extended in 2002 to include Farafenni Town and surrounding villages to support randomized, controlled trials. With over three decades of prospective surveillance, and through specific scientific investigations, the platform (population ≈ 50,000) has generated data on: morbidity and mortality due to malaria in children and during pregnancy; non-communicable disease among adults; reproductive health; and levels and trends in childhood and maternal mortality. Other information routinely collected includes causes of death through verbal autopsy, and household socioeconomic indicators. The current portfolio of the platform includes tracking Millennium Development Goal 4 (MDG4) attainments in rural Gambia and cause-of-death determination.

  9. Impact of demographic policy on population growth.

    PubMed

    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

  10. Joint Newspaper Operating Agreements.

    ERIC Educational Resources Information Center

    Parsons, Marie

    The number of competing daily newspapers in American cities has dwindled until only about 50 cities boast two papers. Of the newspapers in those cities, 23 now maintain separate editorial operations but have joint printing, advertising, and circulation departments. The concept of joint operation is 50 years old, dating from the Depression years…

  11. Jointness, A Selected Bibliography.

    DTIC Science & Technology

    1997-02-01

    Joint warfare is team warfare. Joint Pub 1 purple- suiter -An officer assigned to duty on a staff where no particu- lar service predominates. This may...Force Quarterly, no. 5 (Summer 1994): 64-70. Winton, Harold R. "Partnership and Tension: The Army and Air Force Between Vietnam and Desert Shield

  12. Demographics of Resonances in Exoplanetary Systems

    NASA Astrophysics Data System (ADS)

    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. Emergence of Rapid Evolution from Demographic Stochasticity

    NASA Astrophysics Data System (ADS)

    Shih, Hong-Yan; Goldenfeld, Nigel

    2014-03-01

    The phenomenon of ``rapid evolution'' arises when genetic variation occurs fast enough to significantly change ecodynamics. Data from experiments with algae-rotifer system and bacteria-phage system show unusual dynamics when there are subpopulations of preys with different trait values, including predator-prey phase shifts near π (and distinct from the canonical value of π / 2) and so-called cryptic cycles, in which populations of preys remain constant while the predator population oscillates. Such phenomena have been modeled with deterministic differential equations containing empirical Michaelis-Menten kinetic terms and the unusual dynamics that is attributed to postulate complicated trade-off between sub-populations. Here we present a generic individual-level stochastic model of interacting populations that includes a subpopulation resistant to the predator but with metabolic cost. We solve this model by using a master equation approach, and by performing system size expansion, we find that antiphase and cryptic quasi-cycles can emerge from the combination of intrinsic demographic fluctuations and clonal mutations alone. These analytic results are then compared with Gillespie simulations, and the typical phase diagram of the system is calculated.

  14. Demographic controls of future global fire risk

    NASA Astrophysics Data System (ADS)

    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.

  15. Algeria. From demographic explosion to social rupture.

    PubMed

    Fargues, P

    1994-01-01

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

  16. Jointness for the Rest of Us: Reforming Joint Professional Development

    DTIC Science & Technology

    2016-06-10

    Vision 2020 (JV 2020 ) is the conceptual template established to guide the transformation of America’s Armed Forces. According to this template, the...of Staff. Joint Vision 2020 , (Washington DC. Office of the Chairman of the Joint Chiefs of Staff Joint Electronic Library, February 2001):1. 2 Ibid...Staffs of Staff, 2011. __________. Joint Vision 2020 .Washington DC. Office of the Chairman of the Joint Chiefs of Staff Joint Electronic Library

  17. Handbook on dynamics of jointed structures.

    SciTech Connect

    Ames, Nicoli M.; Lauffer, James P.; Jew, Michael D.; Segalman, Daniel Joseph; Gregory, Danny Lynn; Starr, Michael James; Resor, Brian Ray

    2009-07-01

    The problem of understanding and modeling the complicated physics underlying the action and response of the interfaces in typical structures under dynamic loading conditions has occupied researchers for many decades. This handbook presents an integrated approach to the goal of dynamic modeling of typical jointed structures, beginning with a mathematical assessment of experimental or simulation data, development of constitutive models to account for load histories to deformation, establishment of kinematic models coupling to the continuum models, and application of finite element analysis leading to dynamic structural simulation. In addition, formulations are discussed to mitigate the very short simulation time steps that appear to be required in numerical simulation for problems such as this. This handbook satisfies the commitment to DOE that Sandia will develop the technical content and write a Joints Handbook. The content will include: (1) Methods for characterizing the nonlinear stiffness and energy dissipation for typical joints used in mechanical systems and components. (2) The methodology will include practical guidance on experiments, and reduced order models that can be used to characterize joint behavior. (3) Examples for typical bolted and screw joints will be provided.

  18. Cygnus History

    SciTech Connect

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

    2009-07-02

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

  19. Senior Officer Oral History Program Project Handlist. [Revised.

    ERIC Educational Resources Information Center

    Army War Coll., Carlisle Barracks, PA.

    The Senior Officer Oral History Program (SOOHP) is sponsored jointly by the U.S. Army War College and the U.S. Army Military History Institute, as an educational service. As of 1992, this program includes over 2,000 hours of taped interviews and 100,000 transcribed pages covering 900 military personalities and special topics. This document is a…

  20. Pressure vessel flex joint

    NASA Technical Reports Server (NTRS)

    Kahn, Jon B. (Inventor)

    1992-01-01

    An airtight, flexible joint is disclosed for the interfacing of two pressure vessels such as between the Space Station docking tunnel and the Space Shuttle Orbiter bulkhead adapter. The joint provides for flexibility while still retaining a structural link between the two vessels required due to the loading created by the internal/external pressure differential. The joint design provides for limiting the axial load carried across the joint to a specific value, a function returned in the Orbiter/Station tunnel interface. The flex joint comprises a floating structural segment which is permanently attached to one of the pressure vessels through the use of an inflatable seal. The geometric configuration of the joint causes the tension between the vessels created by the internal gas pressure to compress the inflatable seal. The inflation pressure of the seal is kept at a value above the internal/external pressure differential of the vessels in order to maintain a controlled distance between the floating segment and pressure vessel. The inflatable seal consists of either a hollow torus-shaped flexible bladder or two rolling convoluted diaphragm seals which may be reinforced by a system of straps or fabric anchored to the hard structures. The joint acts as a flexible link to allow both angular motion and lateral displacement while it still contains the internal pressure and holds the axial tension between the vessels.

  1. Demographic Faultlines: A Meta-Analysis of the Literature

    ERIC Educational Resources Information Center

    Thatcher, Sherry M. B.; Patel, Pankaj C.

    2011-01-01

    We propose and test a theoretical model focusing on antecedents and consequences of demographic faultlines. We also posit contingencies that affect overall team dynamics in the context of demographic faultlines, such as the study setting and performance measurement. Using meta-analysis structural equation modeling with a final data set consisting…

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

    ERIC Educational Resources Information Center

    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.…

  3. Strategic Responses to Demographic Changes: Students, Faculty, and Patrons.

    ERIC Educational Resources Information Center

    Scott, Robert A.

    Demographic changes affecting college students, faculty, and patrons and responses to the changes are considered. For each of the three groups, attention is directed to factors influencing change within and outside the campus, options available to the campus, and strategies for responding to the demographic changes. To recruit new full-time…

  4. Making the Case for Demographic Data in Extension Programming

    ERIC Educational Resources Information Center

    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…

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

    ERIC Educational Resources Information Center

    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…

  6. Demographic Trends and Economic Problems: A Challenge for Swedish Education.

    ERIC Educational Resources Information Center

    Dahllof, Urban

    1981-01-01

    Present economic difficulties in Sweden, it is suggested, pose a threat to educational policy for which demographic development could otherwise offer alternatives aimed primarily at promoting qualitative progress. The present demographic situation is dominated by changes in three dimensions: the size of its younger age groups, internal migration,…

  7. Language Minority Student Demographics in Maine Schools, 1997-98.

    ERIC Educational Resources Information Center

    Berube, Barney

    The report provides both statewide and school district summative data concerning language minority (LM) student demographics in Maine. Statewide data include a demographic overview, annual LM enrollments, high-concentration LM areas, distribution of minority languages, by language or language group, number of Maine public schools enrolling…

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

    ERIC Educational Resources Information Center

    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,…

  9. A Classroom Activity to Illustrate the Demographic Transition

    ERIC Educational Resources Information Center

    Weihe, Paul

    2006-01-01

    A discussion of the Demographic Transition is included in many Environmental Biology or Environmental Science classes. The Demographic Transition occurs as a nation becomes more urban and wealthy, and was widely observed in the twentieth century. The phenomenon includes decreasing family size (fewer children) across generations. In this classroom…

  10. Demographic trends, population policy and public opinion.

    PubMed

    Palomba, R; Bonifazi, C; Menniti, A

    1989-01-01

    Findings are analyzed of the Instituto di Richerche solla poplazione survey carried out in Italy in 1987 which focused on: 1) those variables which may be indirectly affecting Italian's fertility intentions, and 2) the degree of acceptability of a global social policy i.e., one that is not only restricted to economic incentives to be offered to families. Data was obtained from a national sample of 1500 people between 18-49 years. Italians have a good awareness of demographic issues; 61% knew of the decline in marriages; 72% were aware of the increasing aging population; 50% viewed the fall in birth rate negatively; and 41% thought that population and fertility trends would remain at the present low level or would decrease even further (49%). The birth rate decline was contributed to economic reasons at both reasons at both a global and an individual level. The majority of people did not show any signs of prejudice toward immigrants; however, they did favor limiting the number of foreigners in general with the exception of political refugees. The majority were also in favor of helping 3rd World countries. Although Italians value their children and the parent-child relationship very highly, a reduction in the value of children with increasing educational level of the respondents was observed. 83% thought that couples should be allowed to have as many children as they wanted; 81% agreed that measures regarding contraceptive knowledge and availability should be improved; and 49% were in favor of measures to increase births. Regarding possible new policy measures, 50% were in full agreement on the development and increased efficiency of social services to enable women to go out to work. (author's modified)

  11. Foot Syndactyly: A Clinical and Demographic Analysis

    PubMed Central

    Kim, Jong Ho; Kim, Byung Jun

    2016-01-01

    Background Syndactyly of the foot is the second most common congenital foot anomaly. In East Asia, however, no large case study has been reported regarding the clinical features of isolated foot syndactyly. In this study, we report a review of 118 patients during the last 25 years. Methods We conducted a chart review of patients who underwent surgical correction for foot syndactyly between January 1990 and December 2014. Operations were performed with a dorsal triangular flap and a full-thickness skin graft. The demographics of included patients and their clinical features were evaluated. Surgical outcomes and complications were analyzed. Results Among 118 patients with 194 webs (155 feet), 111 patients showed nonsyndromic cases and 7 patients showed syndromic cases. In 80 unilateral cases (72.1%), the second web was the most frequently involved (37.5%), followed by the fourth (30%), the first (15%), the third (15%), the first and second in combination (1.3%), and the second and third in combination (1.3%). Among 31 bilateral cases, 2 cases were asymmetric. Among the remaining 29 symmetric bilateral cases, the second web was the most frequently involved (45.2%), followed by the first (22.6%), and the fourth (6.5%). No specific postoperative complications were observed, except in the case of 1 patient (0.51%) who required a secondary operation to correct web creep. Conclusions This retrospective clinical study of 118 patients with both unilateral and bilateral foot syndactyly revealed that the second web was the most frequently involved. In addition, complete division and tension-free wound closure with a full-thickness skin graft of sufficient size showed good postoperative results. PMID:27896188

  12. The demographics of military children and families.

    PubMed

    Clever, Molly; Segal, David R

    2013-01-01

    Since the advent of the all-volunteer force in the 1970s, marriage, parenthood, and family life have become commonplace in the U.S. military among enlisted personnel and officers alike, and military spouses and children now outnumber service members by a ratio of 1.4 to 1. Reviewing data from the government and from academic and nonacademic research, Molly Clever and David R. Segal find several trends that distinguish today's military families. Compared with civilians, for example, service members marry younger and start families earlier. Because of the requirements of their jobs, they move much more frequently than civilians do, and they are often separated from their families for months at a time. And despite steady increases since the 1970s in the percentage of women who serve, the armed forces are still overwhelmingly male, meaning that the majority of military parents are fathers. Despite these distinguishing trends, Clever and Segal's chief finding is that military families cannot be neatly pigeonholed. Instead, they are a strikingly diverse population with diverse needs. Within the military, demographic groups differ in important ways, and the service branches differ from one another as well. Military families themselves come in many forms, including not only the categories familiar from civilian life--two-parent, single-parent, and so on--but also, unique to the military, dual-service families in which both parents are service members. Moreover, military families' needs change over time as they move through personal and military transitions. Thus the best policies and programs to help military families and children are flexible and adaptable rather than rigidly structured.

  13. Demographics of the European apicultural industry.

    PubMed

    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

  14. Demographics of the European Apicultural Industry

    PubMed Central

    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

  15. Compliant Joints For Robots

    NASA Technical Reports Server (NTRS)

    Kerley, James J., Jr.

    1990-01-01

    Compliant joints devised to accommodate misalignments of tools and/or workpieces with respect to robotic manipulators. Has characteristics and appearance of both universal-joint and cable-spring-type flexible shaft coupling. Compliance derived from elastic properties of short pieces of cable. Compliance of joint determined by lengths, distances between, relative orientations, thickness of strands, number of strands, material, amount of pretwist, and number of short pieces of cable. Worm-drive mechanism used to adjust lengths to vary compliance as needed during operation.

  16. Joint Robotics Program

    DTIC Science & Technology

    2008-04-23

    Åèìáëáíáçå= oÉëÉ~êÅÜ=póãéçëáìã= JOINT ROBOTICS PROGRAM Published: 23 April 2008 by Joel Brown and Paul Varian 5th Annual Acquisition Research...3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Joint Robotics Program 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM...ëóåÉêÖó=Ñçê=áåÑçêãÉÇ=ÅÜ~åÖÉ=======- 464 - = = Joint Robotics Program Presenter: Joel Brown, Defense Acquisition University Author: Paul Varian

  17. Total ankle joint replacement.

    PubMed

    2016-02-01

    Ankle arthritis results in a stiff and painful ankle and can be a major cause of disability. For people with end-stage ankle arthritis, arthrodesis (ankle fusion) is effective at reducing pain in the shorter term, but results in a fixed joint, and over time the loss of mobility places stress on other joints in the foot that may lead to arthritis, pain and dysfunction. Another option is to perform a total ankle joint replacement, with the aim of giving the patient a mobile and pain-free ankle. In this article we review the efficacy of this procedure, including how it compares to ankle arthrodesis, and consider the indications and complications.

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

    PubMed

    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.

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

    PubMed

    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.

  20. Origin and demographic history of the endemic Taiwan spruce (Picea morrisonicola).

    PubMed

    Bodare, Sofia; Stocks, Michael; Yang, Jeng-Chuann; Lascoux, Martin

    2013-09-01

    Taiwan spruce (Picea morrisonicola) is a vulnerable conifer species endemic to the island of Taiwan. A warming climate and competition from subtropical tree species has limited the range of Taiwan spruce to the higher altitudes of the island. Using seeds sampled from an area in the central mountain range of Taiwan, 15 nuclear loci were sequenced in order to measure genetic variation and to assess the long-term genetic stability of the species. Genetic diversity is low and comparable to other spruce species with limited ranges such as Picea breweriana, Picea chihuahuana, and Picea schrenkiana. Importantly, analysis using approximate Bayesian computation (ABC) provides evidence for a drastic decline in the effective population size approximately 0.3-0.5 million years ago (mya). We used simulations to show that this is unlikely to be a false-positive result due to the limited sample used here. To investigate the phylogenetic origin of Taiwan spruce, additional sequencing was performed in the Chinese spruce Picea wilsonii and combined with previously published data for three other mainland China species, Picea purpurea, Picea likiangensis, and P. schrenkiana. Analysis of population structure revealed that P. morrisonicola clusters most closely with P. wilsonii, and coalescent analyses using the program MIMAR dated the split to 4-8 mya, coincidental to the formation of Taiwan. Considering the population decrease that occurred after the split, however, led to a much more recent origin.

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

    PubMed Central

    2014-01-01

    Background Habitat fragmentation has accelerated within the last century, but may have been ongoing over longer time scales. We analyzed the timing and genetic consequences of fragmentation in two isolated lake-dwelling brown trout populations. They are from the same river system (the Gudenå River, Denmark) and have been isolated from downstream anadromous trout by dams established ca. 600–800 years ago. For reference, we included ten other anadromous populations and two hatchery strains. Based on analysis of 44 microsatellite loci we investigated if the lake populations have been naturally genetically differentiated from anadromous trout for thousands of years, or have diverged recently due to the establishment of dams. Results Divergence time estimates were based on 1) Approximate Bayesian Computation and 2) a coalescent-based isolation-with-gene-flow model. Both methods suggested divergence times ca. 600–800 years bp, providing strong evidence for establishment of dams in the Medieval as the factor causing divergence. Bayesian cluster analysis showed influence of stocked trout in several reference populations, but not in the focal lake and anadromous populations. Estimates of effective population size using a linkage disequilibrium method ranged from 244 to > 1,000 in all but one anadromous population, but were lower (153 and 252) in the lake populations. Conclusions We show that genetic divergence of lake-dwelling trout in two Danish lakes reflects establishment of water mills and impassable dams ca. 600–800 years ago rather than a natural genetic population structure. Although effective population sizes of the two lake populations are not critically low they may ultimately limit response to selection and thereby future adaptation. Our results demonstrate that populations may have been affected by anthropogenic disturbance over longer time scales than normally assumed. PMID:24903056

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

    PubMed Central

    Fregel, Rosa; Gomes, Verónica; Gusmão, Leonor; González, Ana M; Cabrera, Vicente M; Amorim, António; Larruga, Jose M

    2009-01-01

    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. PMID:19650893

  3. Gene flow and demographic history of leopards (Panthera pardus) in the central Indian highlands

    PubMed Central

    Dutta, Trishna; Sharma, Sandeep; Maldonado, Jesús E; Wood, Thomas C; Panwar, Hemendra S; Seidensticker, John

    2013-01-01

    Gene flow is a critical ecological process that must be maintained in order to counteract the detrimental effects of genetic drift in subdivided populations, with conservation benefits ranging from promoting the persistence of small populations to spreading adaptive traits in changing environments. We evaluated historical and contemporary gene flow and effective population sizes of leopards in a landscape in central India using noninvasive sampling. Despite the dramatic changes in land-use patterns in this landscape through recent times, we did not detect any signs that the leopard populations have been through a genetic bottleneck, and they appear to have maintained migration–drift equilibrium. We found that historical levels of gene flow (mean mh = 0.07) were significantly higher than contemporary levels (mean mc = 0.03), and populations with large effective population sizes (Satpura and Kanha Tiger Reserves) are the larger exporters of migrants at both timescales. The greatest decline in historical versus contemporary gene flow is between pairs of reserves that are currently not connected by forest corridors (i.e., Melghat-Pench mh − mc = 0.063; and Kanha-Satpura mh − mc = 0.054). We attribute this reduction in gene flow to accelerated fragmentation and habitat alteration in the landscape over the past few centuries, and suggest protection of forest corridors to maintain gene flow in this landscape. PMID:24062803

  4. Demographic History of the Genus Pan Inferred from Whole Mitochondrial Genome Reconstructions

    PubMed Central

    Tucci, Serena; de Manuel, Marc; Ghirotto, Silvia; Benazzo, Andrea; Prado-Martinez, Javier; Lorente-Galdos, Belen; Nam, Kiwoong; Dabad, Marc; Hernandez-Rodriguez, Jessica; Comas, David; Navarro, Arcadi; Schierup, Mikkel H.; Andres, Aida M.; Barbujani, Guido; Hvilsom, Christina; Marques-Bonet, Tomas

    2016-01-01

    The genus Pan is the closest genus to our own and it includes two species, Pan paniscus (bonobos) and Pan troglodytes (chimpanzees). The later is constituted by four subspecies, all highly endangered. The study of the Pan genera has been incessantly complicated by the intricate relationship among subspecies and the statistical limitations imposed by the reduced number of samples or genomic markers analyzed. Here, we present a new method to reconstruct complete mitochondrial genomes (mitogenomes) from whole genome shotgun (WGS) datasets, mtArchitect, showing that its reconstructions are highly accurate and consistent with long-range PCR mitogenomes. We used this approach to build the mitochondrial genomes of 20 newly sequenced samples which, together with available genomes, allowed us to analyze the hitherto most complete Pan mitochondrial genome dataset including 156 chimpanzee and 44 bonobo individuals, with a proportional contribution from all chimpanzee subspecies. We estimated the separation time between chimpanzees and bonobos around 1.15 million years ago (Mya) [0.81–1.49]. Further, we found that under the most probable genealogical model the two clades of chimpanzees, Western + Nigeria-Cameroon and Central + Eastern, separated at 0.59 Mya [0.41–0.78] with further internal separations at 0.32 Mya [0.22–0.43] and 0.16 Mya [0.17–0.34], respectively. Finally, for a subset of our samples, we compared nuclear versus mitochondrial genomes and we found that chimpanzee subspecies have different patterns of nuclear and mitochondrial diversity, which could be a result of either processes affecting the mitochondrial genome, such as hitchhiking or background selection, or a result of population dynamics. PMID:27345955

  5. Demographic History of the Genus Pan Inferred from Whole Mitochondrial Genome Reconstructions.

    PubMed

    Lobon, Irene; Tucci, Serena; de Manuel, Marc; Ghirotto, Silvia; Benazzo, Andrea; Prado-Martinez, Javier; Lorente-Galdos, Belen; Nam, Kiwoong; Dabad, Marc; Hernandez-Rodriguez, Jessica; Comas, David; Navarro, Arcadi; Schierup, Mikkel H; Andres, Aida M; Barbujani, Guido; Hvilsom, Christina; Marques-Bonet, Tomas

    2016-07-03

    The genus Pan is the closest genus to our own and it includes two species, Pan paniscus (bonobos) and Pan troglodytes (chimpanzees). The later is constituted by four subspecies, all highly endangered. The study of the Pan genera has been incessantly complicated by the intricate relationship among subspecies and the statistical limitations imposed by the reduced number of samples or genomic markers analyzed. Here, we present a new method to reconstruct complete mitochondrial genomes (mitogenomes) from whole genome shotgun (WGS) datasets, mtArchitect, showing that its reconstructions are highly accurate and consistent with long-range PCR mitogenomes. We used this approach to build the mitochondrial genomes of 20 newly sequenced samples which, together with available genomes, allowed us to analyze the hitherto most complete Pan mitochondrial genome dataset including 156 chimpanzee and 44 bonobo individuals, with a proportional contribution from all chimpanzee subspecies. We estimated the separation time between chimpanzees and bonobos around 1.15 million years ago (Mya) [0.81-1.49]. Further, we found that under the most probable genealogical model the two clades of chimpanzees, Western + Nigeria-Cameroon and Central + Eastern, separated at 0.59 Mya [0.41-0.78] with further internal separations at 0.32 Mya [0.22-0.43] and 0.16 Mya [0.17-0.34], respectively. Finally, for a subset of our samples, we compared nuclear versus mitochondrial genomes and we found that chimpanzee subspecies have different patterns of nuclear and mitochondrial diversity, which could be a result of either processes affecting the mitochondrial genome, such as hitchhiking or background selection, or a result of population dynamics.

  6. Demographic history and adaptation account for clock gene diversity in humans

    PubMed Central

    Dall'Ara, I; Ghirotto, S; Ingusci, S; Bagarolo, G; Bertolucci, C; Barbujani, G

    2016-01-01

    Circadian clocks give rise to daily oscillations in behavior and physiological functions that often anticipate upcoming environmental changes generated by the Earth rotation. In model organisms a relationship exists between several genes affecting the circadian rhythms and latitude. We investigated the allele distributions at 116 000 single-nucleotide polymorphisms (SNPs) of 25 human clock and clock-related genes from the 1000Genomes Project, and at a reference data set of putatively neutral polymorphisms. The global genetic structure at the clock genes did not differ from that observed at the reference data set. We then tested for evidence of local adaptation searching for FST outliers under both an island and a hierarchical model, and for significant association between allele frequencies and environmental variables by a Bayesian approach. A total of 230 SNPs in 23 genes, or 84 SNPs in 19 genes, depending on the significance thresholds chosen, showed signs of local adaptation, whereas a maximum of 190 SNPs in 23 genes had significant covariance with one or more environmental variables. Only two SNPs from two genes (NPAS2 and AANAT) exhibit both elevated population differentiation and covariance with at least one environmental variable. We then checked whether the SNPs emerging from these analyses fall within a set of candidate SNPs associated with different chronotypes or sleep disorders. Correlation of five such SNPs with environmental variables supports a selective role of latitude or photoperiod, but certainly not a major one. PMID:27301334

  7. Impact Of Selfing On The Inference Of Demographic History From Whole Genomes In Theobroma cacao L.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Theobroma cacao L (cacao: Malvaceae) is a small tree found naturally in the Amazonian rain forest. An interesting feature of cacao is that it persists in populations of naturally outcrossing and inbreeding plants, as it is a species with a complex system of self-incompatibility, where a fraction of...

  8. Phylogeography and demographic history of Babina pleuraden (Anura, Ranidae) in southwestern China.

    PubMed

    Li, Zejun; Yu, Guohua; Rao, Dingqi; Yang, Junxing

    2012-01-01

    Factors that determine genetic structure of species in southwestern China remain largely unknown. In this study, sequences of two mitochondrial genes (COI and cyt b) were determined to investigate the phylogeography and demography of Babina pleuraden, a pond frog endemic to southwestern China. A total of 262 individuals from 22 populations across the entire range of the species were collected. Our results indicate that B. pleuraden comprises five well-supported mitochondrial lineages roughly corresponding to five geographical areas. The phylogeographic structure of B. pleuraden has been shaped primarily by the unique regional responses of the Yunnan Plateau to the rapid uplift of the Qinghai-Tibetan Plateau occurred c. 2.5 Mya (B phrase of Qingzang Movement) and climatic oscillation during middle Pleistocene (c. 0.64-0.36 Mya), rather than by the paleo-drainage systems. The present wide distribution of the species has resulted from recent population expansion (c. 0.053-0.025 Mya) from multiple refugia prior to the Last Glacial Maximum, corresponding to the scenario of "refugia within refugia".

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

  11. The Future of History and History Teaching.

    ERIC Educational Resources Information Center

    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…

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

    PubMed

    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.

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

    NASA Astrophysics Data System (ADS)

    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.

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

    PubMed Central

    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. PMID:27293619

  15. Conservation biology for suites of species: Demographic modeling for Pacific island kingfishers

    USGS Publications Warehouse

    Kesler, D.C.; Haig, S.M.

    2007-01-01

    Conservation practitioners frequently extrapolate data from single-species investigations when managing critically endangered populations. However, few researchers initiate work with the intent of making findings useful to conservation efforts for other species. We presented and explored the concept of conducting conservation-oriented research for suites of geographically separated populations with similar natural histories, resource needs, and extinction threats. An example was provided in the form of an investigation into the population demography of endangered Micronesian kingfishers (Todiramphus cinnamominus). We provided the first demographic parameter estimates for any of the 12 endangered Pacific Todiramphus species, and used results to develop a population projection matrix model for management throughout the insular Pacific. Further, we used the model for elasticity and simulation analyses with demographic values that randomly varied across ranges that might characterize congener populations. Results from elasticity and simulation analyses indicated that changes in breeding adult survival exerted the greatest magnitude of influence on population dynamics. However, changes in nestling survival were more consistently correlated with population dynamics as demographic rates were randomly altered. We concluded that conservation practitioners working with endangered Pacific kingfishers should primarily focus efforts on factors affecting nestling and breeder survival, and secondarily address fledgling juveniles and helpers. Further, we described how the generalized base model might be changed to focus on individual populations and discussed the potential application of multi-species models to other conservation situations. ?? 2007 Elsevier Ltd. All rights reserved.

  16. Background and History of the Joint Committee's Program Evaluation Standards

    ERIC Educational Resources Information Center

    Yarbrough, Donald B.; Shulha, Lyn M.; Caruthers, Flora

    2004-01-01

    It is generally thought that evaluation originated with the civil service exams that were administered in ancient China. However, modern evaluation and, of particular importance to this article, evaluation standards, originated in the United States. Why this occurred is part of a larger question about the development of social and educational…

  17. The Joint Confidence Level Paradox: A History of Denial

    NASA Technical Reports Server (NTRS)

    Butts, Glenn; Linton, Kent

    2009-01-01

    This paper is intended to provide a reliable methodology for those tasked with generating price tags on construction (C0F) and research and development (R&D) activities in the NASA performance world. This document consists of a collection of cost-related engineering detail and project fulfillment information from early agency days to the present. Accurate historical detail is the first place to start when determining improved methodologies for future cost and schedule estimating. This paper contains a beneficial proposed cost estimating method for arriving at more reliable numbers for future submits. When comparing current cost and schedule methods with earlier cost and schedule approaches, it became apparent that NASA's organizational performance paradigm has morphed. Mission fulfillment speed has slowed and cost calculating factors have increased in 21st Century space exploration.

  18. Shoulder Joint Replacement

    MedlinePlus

    ... examination. This will assess shoulder motion, stability, and strength. joint. (Right) Osteoarthritis of the shoulder. Note the ... you can start moving sooner and get your strength back more quickly. Talk with your surgeon if ...

  19. Evaluating the Y chromosomal timescale in human demographic and lineage dating

    PubMed Central

    2014-01-01

    Y chromosome is a superb tool for inferring human evolution and recent demographic history from a paternal perspective. However, Y chromosomal substitution rates obtained using different modes of calibration vary considerably, and have produced disparate reconstructions of human history. Here, we discuss how substitution rate and date estimates are affected by the choice of different calibration points. We argue that most Y chromosomal substitution rates calculated to date have shortcomings, including a reliance on the ambiguous human-chimpanzee divergence time, insufficient sampling of deep-rooting pedigrees, and using inappropriate founding migrations, although the rates obtained from a single pedigree or calibrated with the peopling of the Americas seem plausible. We highlight the need for using more deep-rooting pedigrees and ancient genomes with reliable dates to improve the rate estimation. PMID:25215184

  20. Panel Post & Diagonal Brace Joint Detail; Crossbracing Center Joint ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Panel Post & Diagonal Brace Joint Detail; Crossbracing Center Joint Detail; Chord, Panel Post, Tie Bar, & Diagonal Brace Joint Detail; Chord, Tie Bar, & Crossbracing Joint Detail - Medora Bridge, Spanning East Fork of White River at State Route 235, Medora, Jackson County, IN

  1. Jointness: A Selected Bibliography

    DTIC Science & Technology

    2010-12-01

    JOINTNESS A Selected Bibliography U.S. ARMY WAR COLLEGE LIBRARY December 2010 Report Documentation Page Form...Lenore Garder 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) U.S. Army War College...of the U.S. Army War College. A revised and updated version of our earlier bibliographies on jointness, it focuses on aspects of United States

  2. Successfully Developing Joint Leaders

    DTIC Science & Technology

    2010-07-26

    least for the ROTC aspect of the Navy commissioning source, this is about to change at the University of South Florida (USF). In fact the “Joint...get their training over a six- month period at Fort Sill, Oklahoma. A Marine aviator will go through Pensacola Naval Air Station, Florida alongside...MCAS Beaufort, he served in Afghanistan as “Commanding Officer of Taskforce Panther , a joint coalition taskforce in support of OEF” (http

  3. Demographic situation and development in Nepal.

    PubMed

    Pradhanang, A L

    1983-01-01

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

  4. Health & Demographic Surveillance System Profile: The Magu Health and Demographic Surveillance System (Magu HDSS)

    PubMed Central

    Kishamawe, Coleman; Isingo, Raphael; Mtenga, Baltazar; Zaba, Basia; Todd, Jim; Clark, Benjamin; Changalucha, John; Urassa, Mark

    2015-01-01

    The Magu Health and Demographic Surveillance System (Magu HDSS) is part of Kisesa OpenCohort HIV Study located in a rural area of North-Western Tanzania. Since its establishment in 1994, information on pregnancies, births, marriages, migrations and deaths have been monitored and updated between one and three times a year by trained fieldworkers. Other research activities implemented in the cohort include: sero surveys which have been conducted every 2–3 years to collect socioeconomic data, HIV sero status and health knowledge attitude and behaviour in adults aged 15 years or more living in the area; verbal autopsy (VA) interviews conducted to establish cause of death in all deaths encountered in the area; Llnking data collected at health facilities to community-based data; monitoring voluntary counselling and testing (VCT); and assessing uptake of antiretroviral treatment (ART). In addition, within the community, qualitative studies have been conducted to address issues linked to HIV stigma, the perception of ART access and adherence. In 2014, the population was over 35 000 individuals. Magu HDSS has contributed to Tanzanian estimates of fertility and mortality, and is a member of the INDEPTH network. Demographic data for Magu HDSS are available via the INDEPTH Network’s Sharing and Accessing Repository (iSHARE) and applications to access HDSS data for collaborative analysis are encouraged. PMID:26403815

  5. Health & Demographic Surveillance System Profile: The Muzaffarpur-TMRC Health and Demographic Surveillance System

    PubMed Central

    Malaviya, Paritosh; Picado, Albert; Hasker, Epco; Ostyn, Bart; Kansal, Sangeeta; Singh, Rudra Pratap; Shankar, Ravi; Boelaert, Marleen; Sundar, Shyam

    2014-01-01

    The Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS), established in 2007, was developed as an enlargement of the scope of a research collaboration on the project Visceral Leishmaniasis in Bihar, which had been ongoing since 2005. The HDSS is located in a visceral leishmaniasis (VL)-endemic area in the Muzaffarpur district of Bihar state in India. It is the only HDSS conducting research on VL, which is a vector-borne infectious disease transmitted by female phlebotomine sandflies and is fatal if left untreated. Currently the HDSS serves a population of over 105 000 in 66 villages. The HDSS collects data on vital events including pregnancies, births, deaths, migration and marriages, as well as other socio-economic indicators, at regular intervals. Incident VL cases are identified. The HDSS team is experienced in conducting both qualitative and quantitative studies, sample collection and rapid diagnostic tests in the field. In each village, volunteers connect the HDSS team with the community members. The Muzaffarpur-TMRC HDSS provides opportunities for studies on VL and other neglected tropical diseases (NTDs) and their interaction with demographic events such as migration. Queries related to research collaborations and data sharing can be sent to Dr Shyam Sundar at [drshyamsundar@hotmail.com]. PMID:25186307

  6. Health & Demographic Surveillance System Profile: The Rufiji Health and Demographic Surveillance System (Rufiji HDSS).

    PubMed

    Mrema, Sigilbert; Kante, Almamy M; Levira, Francis; Mono, Amaniel; Irema, Kahema; de Savigny, Don; Masanja, Honorati

    2015-04-01

    The Rufiji Health and Demographic Surveillance System (HDSS) was established in October 1998 to evaluate the impact on burden of disease of health system reforms based on locally generated data, prioritization, resource allocation and planning for essential health interventions. The Rufiji HDSS collects detailed information on health and survival and provides a framework for population-based health research of relevance to local and national health priorities.In December 2012 the population under surveillance was about 105,503 people, residing in 19,315 households. Monitoring of households and members within households is undertaken in regular 6-month cycles known as 'rounds'. Self reported information is collected on demographic, household, socioeconomic and geographical characteristics. Verbal autopsy is conducted using standardized questionnaires, to determine probable causes of death. In conjunction with core HDSS activities, the ongoing studies in Rufiji HDSS focus on maternal and new-born health, evaluation of safety of artemether-lumefantrine (AL) exposure in early pregnancy and the clinical safety of a fixed dose of dihydroartemisinin-piperaquine (DHA-PQP) in the community. Findings of studies conducted in Rufiji HDSS can be accessed at www.ihi.or.tz/IHI-Digital-Library.

  7. Health & demographic surveillance system profile: the Nahuche Health and Demographic Surveillance System, Northern Nigeria (Nahuche HDSS).

    PubMed

    Alabi, Olatunji; Doctor, Henry V; Jumare, Abdulazeez; Sahabi, Nasiru; Abdulwahab, Ahmad; Findley, Sally E; Abubakar, Sani D

    2014-12-01

    The Nahuche Health and Demographic Surveillance System (HDSS) study site, established in 2009 with 137 823 individuals is located in Zamfara State, north western Nigeria. North-West Nigeria is a region with one of the worst maternal and child health indicators in Nigeria. For example, the 2013 Nigeria Demographic and Health Survey estimated an under-five mortality rate of 185 deaths per 1000 live births for the north-west geo-political zone compared with a national average of 128 deaths per 1000 live births. The site comprises over 100 villages under the leadership of six district heads. Virtually all the residents of the catchment population are Hausa by ethnicity. After a baseline census in 2010, regular update rounds of data collection are conducted every 6 months. Data collection on births, deaths, migration events, pregnancies, marriages and marriage termination events are routinely conducted. Verbal autopsy (VA) data are collected on all deaths reported during routine data collection. Annual update data on antenatal care and household characteristics are also collected. Opportunities for collaborations are available at Nahuche HDSS. The Director of Nahuche HDSS, M.O. Oche at [ochedr@hotmail.com] is the contact person for all forms of collaboration.

  8. Health & Demographic Surveillance System Profile: The Magu Health and Demographic Surveillance System (Magu HDSS).

    PubMed

    Kishamawe, Coleman; Isingo, Raphael; Mtenga, Baltazar; Zaba, Basia; Todd, Jim; Clark, Benjamin; Changalucha, John; Urassa, Mark

    2015-12-01

    The Magu Health and Demographic Surveillance System (Magu HDSS) is part of Kisesa OpenCohort HIV Study located in a rural area of North-Western Tanzania. Since its establishment in 1994, information on pregnancies, births, marriages, migrations and deaths have been monitored and updated between one and three times a year by trained fieldworkers. Other research activities implemented in the cohort include: sero surveys which have been conducted every 2-3 years to collect socioeconomic data, HIV sero status and health knowledge attitude and behaviour in adults aged 15 years or more living in the area; verbal autopsy (VA) interviews conducted to establish cause of death in all deaths encountered in the area; Llnking data collected at health facilities to community-based data; monitoring voluntary counselling and testing (VCT); and assessing uptake of antiretroviral treatment (ART). In addition, within the community, qualitative studies have been conducted to address issues linked to HIV stigma, the perception of ART access and adherence.In 2014, the population was over 35 000 individuals. Magu HDSS has contributed to Tanzanian estimates of fertility and mortality, and is a member of the INDEPTH network. Demographic data for Magu HDSS are available via the INDEPTH Network's Sharing and Accessing Repository (iSHARE) and applications to access HDSS data for collaborative analysis are encouraged.

  9. High pressure ceramic joint

    DOEpatents

    Ward, Michael E.; Harkins, Bruce D.

    1993-01-01

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures.

  10. High pressure ceramic joint

    DOEpatents

    Ward, M.E.; Harkins, B.D.

    1993-11-30

    Many recuperators have components which react to corrosive gases and are used in applications where the donor fluid includes highly corrosive gases. These recuperators have suffered reduced life, increased service or maintenance, and resulted in increased cost. The present joint when used with recuperators increases the use of ceramic components which do not react to highly corrosive gases. Thus, the present joint used with the present recuperator increases the life, reduces the service and maintenance, and reduces the increased cost associated with corrosive action of components used to manufacture recuperators. The present joint is comprised of a first ceramic member, a second ceramic member, a mechanical locking device having a groove defined in one of the first ceramic member and the second ceramic member. The joint and the mechanical locking device is further comprised of a refractory material disposed in the groove and contacting the first ceramic member and the second ceramic member. The present joint mechanically provides a high strength load bearing joint having good thermal cycling characteristics, good resistance to a corrosive environment and good steady state strength at elevated temperatures. 4 figures.

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

    PubMed Central

    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

  12. Joint pain. It isn't always arthritis.

    PubMed

    Baum, J

    1989-01-01

    When a history of trauma or overuse is absent in a patient presenting with pain and stiffness in a joint, bursitis and tendinitis should be considered, especially if the patient is elderly. Appropriate questioning can narrow the differential diagnosis, and physical examination confirms the impression gathered by history taking. Treatment may include one or more injections of a local anesthetic (with or without a long-acting corticosteroid), use of an oral corticosteroid or nonsteroidal antiinflammatory agent, and in some cases, surgery.

  13. Population demographics, survival, and reporduction: Alaska sea otter research

    USGS Publications Warehouse

    Monson, D.H.; Bodkin, James L.; Doak, D.F.; Estes, J.A.; Tinker, M.T.; Siniff, D.B.; Maldini, Daniela; Calkins, Donald; Atkinson, Shannon; Meehan, Rosa

    2004-01-01

    The fundamental force behind population change is the balance between age-specific survival and reproductive rates. Thus, understanding population demographics is crucial when trying to interpret trends in population change over time. For many species, demographic rates change as the population’s status (i.e., relative to prey resources) varies. Indices of body condition indicative of individual energy reserves can be a useful gauge of population status. Integrated studies designed to measure (1) population trends; (2) current population status; and (3) demographic rates will provide the most complete picture of the factors driving observed population changes. In particular, estimates of age specific survival and reproduction in conjunction with measures of population change can be integrated into population matrix models useful in explaining observed trends. We focus here on the methods used to measure demographic rates in sea otters, and note the importance of comparable methods between studies. Next, we review the current knowledge of the influence of population status on demographic parameters. We end with examples of the power of matrix modeling as a tool to integrate various types of demographic information for detecting otherwise hard to detect changes in demographic parameters.

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

    USGS Publications Warehouse

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

    2011-01-01

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

  15. Demographic crisis and recovery: a case study of the Xavante of Pimentel Barbosa.

    PubMed

    Flowers, N

    1994-03-01

    This case study of the Xavante of Pimentel Barbosa is an example of an Amazonian Indian group that, when exposed to White society, experienced the common history of diseases and social disruption, and then eventually, recovered from the demographic shock, increased fertility, and reduced mortality. Early contact for the Xavante was during the early 18th century in Goias state, Brazil; by the end of the 19th century the Xavante had migrated west into Mato Grosso in isolation. Brazilian government interests (1940s) and a research expeditionary group (1962) resulted in health posts and extensive genetic, epidemiologic, and demographic studies. The results showed good physical and nutritional status, but stress from epidemic disease and social disruption. Conditions had improved by 1976, and the battle was with encroaching ranchers. Strong indian political action led to the securing of boundaries within the Pimentel Barbosa reservation by 1977. The population doubled from 249 in 1977 to 411 in 1988, and increased to 3 villages. There was evidence of a return to more traditional practices. Data collection for this analysis occurred during 1976-77 and 1988 and 1990. Results were provided for recent demographic change, recent births and deaths, factors affecting fertility, fertility change, parity and infant mortality, life expectancy changes, infanticide, population growth, marriage patterns, and health changes. Fertility histories were collected from 71 women in 1971 and 109 women in 1990. Difficulties were encountered due to Xavante differences in enumeration of children. In the comparison of the surveys in 1977 and 1990, there was close correspondence of reported births, and discrepancies of 4-9 births and in age at death. The difficulties encountered were attributed to problems with interpreters. The demographic analysis showed evidence of introduced diseases, which increased infant mortality and threatened population replacement, followed by decreased infant

  16. Joint Doctrine for Civil Affairs

    DTIC Science & Technology

    2007-11-02

    Authorities ( MACA ), DODD 5525.5, DOD Cooperation with Civilian Law Enforcement Officials, and JP 3-07.7, Joint Doctrine for Civil Support. II-15 Civil Affairs...Joint Operation Planning and Execution System JP joint publication JTF joint task force LOAC law of armed conflict MACA military assistance to civil

  17. Joint Electromagnetic Spectrum Management Operations

    DTIC Science & Technology

    2012-03-20

    synchronizing, and deconflicting JEMSMO actions (p. IV-7) Doctrine Update for JP 6-01, Joint Electromagnetic Spectrum Management Operations...communications system directorate of a joint staff (J-6), to support joint planning, coordination, and control of the spectrum for assigned forces. Executive...in the respective Service or joint publications. Interference Resolution To ensure critical frequencies and spectrum-dependent systems are

  18. [Demographic research in Togo. Evaluation of change and prospects].

    PubMed

    Nomenyo, A

    1986-01-01

    It is only since the independance of Togo, in 1958, and after 3 General Census, (1958-59, 1970, 1981), followed immediately by post-census surveys, that a solid basis of statistical data has been available for demographic research. But it is only after 1970, with the creation of the Benin University, and its Demographic Research Unit, the arrival of researchers at the ORSTOM Center of Lome, and of the demographers trained at the IFORD and IDP, that real demographic research has existed. Since then, the ORSTOM has conducted a study on the dynamics of population (fertility, migration, nuptiality, mortality) and its socioeconomic consequences on the agricultural economy of the Plateau Region (1975-1979). It is currently conducting a study in North Togo, comparing demographic data (nuptiality, fertility, infant mortality, family structure) with socioeconomic data (system of land property, women's activity, wives' status in polygamic families), for a better understanding of the influence of demographic reproduction on global social reproduction. The Demographic Research Unit led several studies on fertility in Southeast Togo and Lome. Several other surveys by the department of statistics and the IFORD, by the INRS, as well as student these from diverse schools of Benin University, are studying demo-geography, demo-economy, and demo-sociology. Still, the main problems are the bad quality of the data on fertility and mortality, and the inconsistancy of civil registration. But the interest of the present administration for demographic information may lead to the creation of a "Population Unit" assisting the government, to the definition of a status for researchers, and to the participation of Togo in the new program of Demographic and Health Surveys planned for 35 countries by the Westinghouse Institute for Resource Development.

  19. Detecting concerted demographic response across community assemblages using hierarchical approximate Bayesian computation.

    PubMed

    Chan, Yvonne L; Schanzenbach, David; Hickerson, Michael J

    2014-09-01

    Methods that integrate population-level sampling from multiple taxa into a single community-level analysis are an essential addition to the comparative phylogeographic toolkit. Detecting how species within communities have demographically tracked each other in space and time is important for understanding the effects of future climate and landscape changes and the resulting acceleration of extinctions, biological invasions, and potential surges in adaptive evolution. Here, we present a statistical framework for such an analysis based on hierarchical approximate Bayesian computation (hABC) with the goal of detecting concerted demographic histories across an ecological assemblage. Our method combines population genetic data sets from multiple taxa into a single analysis to estimate: 1) the proportion of a community sample that demographically expanded in a temporally clustered pulse and 2) when the pulse occurred. To validate the accuracy and utility of this new approach, we use simulation cross-validation experiments and subsequently analyze an empirical data set of 32 avian populations from Australia that are hypothesized to have expanded from smaller refugia populations in the late Pleistocene. The method can accommodate data set heterogeneity such as variability in effective population size, mutation rates, and sample sizes across species and exploits the statistical strength from the simultaneous analysis of multiple species. This hABC framework used in a multitaxa demographic context can increase our understanding of the impact of historical climate change by determining what proportion of the community responded in concert or independently and can be used with a wide variety of comparative phylogeographic data sets as biota-wide DNA barcoding data sets accumulate.

  20. Combining genetic and demographic data for prioritizing conservation actions: insights from a threatened fish species

    PubMed Central

    Paz-Vinas, Ivan; Comte, Lise; Chevalier, Mathieu; Dubut, Vincent; Veyssiere, Charlotte; Grenouillet, Gaël; Loot, Geraldine; Blanchet, Simon

    2013-01-01

    Abstract Prioritizing and making efficient conservation plans for threatened populations requires information at both evolutionary and ecological timescales. Nevertheless, few studies integrate multidisciplinary approaches, mainly because of the difficulty for conservationists to assess simultaneously the evolutionary and ecological status of populations. Here, we sought to demonstrate how combining genetic and demographic analyses allows prioritizing and initiating conservation plans. To do so, we combined snapshot microsatellite data and a 30-year-long demographic survey on a threatened freshwater fish species (Parachondrostoma toxostoma) at the river basin scale. Our results revealed low levels of genetic diversity and weak effective population sizes (<63 individuals) in all populations. We further detected severe bottlenecks dating back to the last centuries (200–800 years ago), which may explain the differentiation of certain populations. The demographic survey revealed a general decrease in the spatial distribution and abundance of P. toxostoma over the last three decades. We conclude that demo-genetic approaches are essential for (1) identifying populations for which both evolutionary and ecological extinction risks are high; and (2) proposing conservation plans targeted toward these at risk populations, and accounting for the evolutionary history of populations. We suggest that demo-genetic approaches should be the norm in conservation practices. We combined genetic and demographic data from a threatened freshwater fish species (Parachondrostoma toxostoma) at the river basin scale for conservation purposes. Genetic diversity and effective population sizes are very low, probably due to the strong genetic bottlenecks detected in this study. The species spatial distribution and abundance also decreased during the last decades. PMID:24567833

  1. Detecting Concerted Demographic Response across Community Assemblages Using Hierarchical Approximate Bayesian Computation

    PubMed Central

    Chan, Yvonne L.; Schanzenbach, David; Hickerson, Michael J.

    2014-01-01

    Methods that integrate population-level sampling from multiple taxa into a single community-level analysis are an essential addition to the comparative phylogeographic toolkit. Detecting how species within communities have demographically tracked each other in space and time is important for understanding the effects of future climate and landscape changes and the resulting acceleration of extinctions, biological invasions, and potential surges in adaptive evolution. Here, we present a statistical framework for such an analysis based on hierarchical approximate Bayesian computation (hABC) with the goal of detecting concerted demographic histories across an ecological assemblage. Our method combines population genetic data sets from multiple taxa into a single analysis to estimate: 1) the proportion of a community sample that demographically expanded in a temporally clustered pulse and 2) when the pulse occurred. To validate the accuracy and utility of this new approach, we use simulation cross-validation experiments and subsequently analyze an empirical data set of 32 avian populations from Australia that are hypothesized to have expanded from smaller refugia populations in the late Pleistocene. The method can accommodate data set heterogeneity such as variability in effective population size, mutation rates, and sample sizes across species and exploits the statistical strength from the simultaneous analysis of multiple species. This hABC framework used in a multitaxa demographic context can increase our understanding of the impact of historical climate change by determining what proportion of the community responded in concert or independently and can be used with a wide variety of comparative phylogeographic data sets as biota-wide DNA barcoding data sets accumulate. PMID:24925925

  2. Demographic transition theory: a neglected aspect of the nomadism-sedentarism continuum.

    PubMed

    Meir, A

    1986-01-01

    This paper proposes an adaptation of demographic transition theory to the nomadism-sedentarism continuum. It is argued that a change along this continuum implies a change in the mode of production, which in turn entails changes in fertility and mortality. The following hypotheses are set forth: 1) at the pastoral phase of a nomadic society, fertility is relatively low and mortality is relatively high, yielding a low rate of natural increase; 2) as a pastoral nomadic society senentarizes, fertility begins to rise and mortality falls, resulting in a sharp rise in natural increase, but as sedentarization becomes more advanced, both these trends slow down somewhat; 3) as the nomadic society becomes fully sedentarized, there is a period in which fertility remains at a high level but then begins to fall slowly, whereas mortality, after reaching a temporary minimum, exhibits a minor increase followed by a resumption of a declining trend; and 4) in the postsedentarization phase, the demographic regime of the ex-nomads becomes similar to the 2nd and 3rd stages of the original demographic transition theory, with a slowdown of the decline in mortality, followed by a later slowdown of fertility and of the rate of natural increase. The hypothesis of rising fertility among sedentarizing nomads is related to both social modernization and economic growth and development, including an improved standard of living and public health services. The interrelated processes of general societal responses to population growth and the changing role of children in the family are assumed to account for the eventual fertility decline. Data from several countries, including a case history from Israel, suggest that birth rates increase along the continuum but their decline at postsedentarization will depend on trends in the general rural sector. Natural increase rates of sedentarizing nomads are considerably higher than those of pastoral nomads. It is concluded that this approach may fill a gap in

  3. The Joint Operating Environment (JOE): Challenges and Implications for the Future Joint Force

    DTIC Science & Technology

    2008-11-25

    be called on to protect our national interests. Merely sustaining the health of the Joint Force, never mind adapting and transforming, is far more...very powerful motives prevent us from doing so – security, honour, and self interest. And we were not the first to act in this way. Far from it.” 4...deep understanding of the enemy – his culture, history, geography, religious and ideological motivations , and particularly the huge differences in

  4. Recent range-wide demographic expansion in a Taiwan endemic montane bird, Steere's Liocichla (Liocichla steerii)

    PubMed Central

    2010-01-01

    Background The subtropical island of Taiwan is an area of high endemism and a complex topographic environment. Phylogeographic studies indicate that vicariance caused by Taiwan's mountains has subdivided many taxa into genetic phylogroups. We used mitochondrial DNA sequences and nuclear microsatellites to test whether the evolutionary history of an endemic montane bird, Steere's Liocichla (Liocichla steerii), fit the general vicariant paradigm for a montane organism. Results We found that while mountains appear to channel gene flow they are not a significant barrier for Steere's Liocichla. Recent demographic expansion was evident, and genetic diversity was relatively high across the island, suggesting expansion from multiple areas rather than a few isolated refugia. Ecological niche modeling corroborated the molecular results and suggested that populations of Steere's Liocichla are connected by climatically suitable habitat and that there was less suitable habitat during the Last Glacial Maximum. Conclusions Genetic and ecological niche modeling data corroborate a single history--Steere's Liocichla was at lower density during the Last Glacial Maximum and has subsequently expanded in population density. We suggest that such a range-wide density expansion might be an overlooked cause for the genetic patterns of demographic expansion that are regularly reported. We find significant differences among some populations in FST indices and an admixture analysis. Though both of these results are often used to suggest conservation action, we affirm that statistically significant results are not necessarily biologically meaningful and we urge caution when interpreting highly polymorphic data such as microsatellites. PMID:20219124

  5. Demographic and clinical features of inclusion body myositis in North America

    PubMed Central

    Paltiel, A. David; Ingvarsson, Einar; Lee, Donald K. K.; Leff, Richard L.; Nowak, Richard J.; Petschke, Kurt D.; Richards-Shubik, Seth; Zhou, Ange; Shubik, Martin; O’Connor, Kevin C.

    2016-01-01

    Objective Define the demographics, natural history, and clinical management of patients with inclusion body myositis (IBM). Background Few studies of the demographics, natural history, and clinical management of IBM have been performed in a large patient population. Methods A cross-sectional, self-reporting survey was conducted. Results The mean age of the 916 participants was 70.4 years, the male-to-female ratio was 2:1, and the majority reported difficulty with ambulation and activities of daily living. The earliest symptoms included impaired use and weakness of arms and legs. The mean time from first symptoms to diagnosis was 4.7 years. Half reported that IBM was their initial diagnosis. A composite functional index negatively associated with age, disease duration, and positively associated with participation in exercise. Conclusion These data are valuable for informing patients how IBM manifestations are expected to impair daily living and indicate that self-reporting could be used to establish outcome measures in clinical trials. PMID:25557419

  6. Postglacial range shift and demographic expansion of the marine intertidal snail Batillaria attramentaria

    PubMed Central

    Ho, Phuong-Thao; Kwan, Ye-Seul; Kim, Boa; Won, Yong-Jin

    2015-01-01

    To address the impacts of past climate changes, particularly since the last glacial period, on the history of the distribution and demography of marine species, we investigated the evolutionary and demographic responses of the intertidal batillariid gastropod, Batillaria attramentaria, to these changes, using the snail as a model species in the northwest Pacific. We applied phylogeographic and divergence population genetic approaches to mitochondrial COI sequences from B. attramentaria. To cover much of its distributional range, 197 individuals collected throughout Korea and 507 publically available sequences (mostly from Japan) were used. Finally, a Bayesian skyline plot (BSP) method was applied to reconstruct the demographic history of this species. We found four differentiated geographic groups around Korea, confirming the presence of two distinct, geographically subdivided haplogroups on the Japanese coastlines along the bifurcated routes of the warm Tsushima and Kuroshio Currents. These two haplogroups were estimated to have begun to split approximately 400,000 years ago. Population divergence analysis supported the hypothesis that the Yellow Sea was populated by a northward range expansion of a small fraction of founders that split from a southern ancestral population since the last glacial maximum (LGM: 26,000–19,000 years ago), when the southern area became re-submerged. BSP analyses on six geographically and genetically defined groups in Korea and Japan consistently demonstrated that each group has exponentially increased approximately since the LGM. This study resolved the phylogeography of B. attramentaria as a series of events connected over space and time; while paleoceanographic conditions determining the connectivity of neighboring seas in East Asia are responsible for the vicariance of this species, the postglacial sea-level rise and warming temperatures have played a crucial role in rapid range shifts and broad demographic expansions of its

  7. Postglacial range shift and demographic expansion of the marine intertidal snail Batillaria attramentaria.

    PubMed

    Ho, Phuong-Thao; Kwan, Ye-Seul; Kim, Boa; Won, Yong-Jin

    2015-01-01

    To address the impacts of past climate changes, particularly since the last glacial period, on the history of the distribution and demography of marine species, we investigated the evolutionary and demographic responses of the intertidal batillariid gastropod, Batillaria attramentaria, to these changes, using the snail as a model species in the northwest Pacific. We applied phylogeographic and divergence population genetic approaches to mitochondrial COI sequences from B. attramentaria. To cover much of its distributional range, 197 individuals collected throughout Korea and 507 publically available sequences (mostly from Japan) were used. Finally, a Bayesian skyline plot (BSP) method was applied to reconstruct the demographic history of this species. We found four differentiated geographic groups around Korea, confirming the presence of two distinct, geographically subdivided haplogroups on the Japanese coastlines along the bifurcated routes of the warm Tsushima and Kuroshio Currents. These two haplogroups were estimated to have begun to split approximately 400,000 years ago. Population divergence analysis supported the hypothesis that the Yellow Sea was populated by a northward range expansion of a small fraction of founders that split from a southern ancestral population since the last glacial maximum (LGM: 26,000-19,000 years ago), when the southern area became re-submerged. BSP analyses on six geographically and genetically defined groups in Korea and Japan consistently demonstrated that each group has exponentially increased approximately since the LGM. This study resolved the phylogeography of B. attramentaria as a series of events connected over space and time; while paleoceanographic conditions determining the connectivity of neighboring seas in East Asia are responsible for the vicariance of this species, the postglacial sea-level rise and warming temperatures have played a crucial role in rapid range shifts and broad demographic expansions of its

  8. Females with FVIII and FIX deficiency have reduced joint range of motion

    PubMed Central

    Sidonio, Robert F.; Mili, Fatima D.; Li, Tengguo; Miller, Connie H.; Hooper, William C.; DeBaun, Michael R.; Soucie, Michael

    2015-01-01

    Little is known about rates of joint bleeding among females with FVIII/FIX deficiency or hemophilia carriers. In a cross-sectional study, we tested the hypothesis that females with FVIII or FIX deficiency enrolled in the Universal Data Collection (UDC) project had a reduced mean overall joint range of motion (ROM) compared with historic controls from the Normal Joint Study. Demographics, clinical characteristics, and joint ROM measurements on 303 females without a bleeding disorder and 148 females with FVIII and FIX deficiency, respectively, between the ages of 2–69 years and a body mass index (BMI) ≤35 were compared. Multivariate linear regression was performed with the overall joint ROM (sum of the right and left ROM measurements of five joints) as the dependent variable and FVIII or FIX activity as the independent variable adjusting for age, race, BMI, and number of joint bleeds reported over the last 6 months. As FVIII and FIX activity decreased, the mean overall joint ROM became reduced and in most cases was significantly lower than that of the controls regardless of age and clinical hemophilia severity. Further investigation of reduced joint ROM as evidence of subclinical joint bleeding in females with FVIII and FIX deficiency is warranted. PMID:24838518

  9. Subtalar joint septic arthritis in a patient with hypogammaglobulinemia.

    PubMed

    Wynes, Jacob; Harris, William; Hadfield, Robert A; Malay, D Scot

    2013-01-01

    The clinical presentation of a monoarticular, red, hot, and swollen joint has many possible diagnoses, including septic arthritis, which is 1 of the most devastating. The morbidity associated with this pathologic process involves permanent joint damage and the potential for progression to systemic illness and, even, mortality. The common risk factors for joint sepsis include a history of rheumatoid arthritis, previous joint surgery, joint prosthesis, intravenous drug abuse, alcoholism, diabetes, previous intra-articular steroid use, and cutaneous ulceration. The diagnosis is primarily determined from the culture results after arthrocentesis and correlation with direct visualization, imaging, and various serologies, including synovial analysis. In the present report, a case of an insidious presentation of subtalar joint septic arthritis and its association with a unique patient presentation concomitant with primary immunodeficiency and culture-proven Myocplasma hominis infection is discussed. Septic arthritis has a predilection for the lower extremities and typically is isolated to the hip or knee, with less common involvement of the ankle or metatarsophalangeal joints. Owing to the uncommon nature of primary immunodeficiency disorders and the paucity of studies discussing their association with septic arthridites, we aimed to raise awareness of subtalar joint septic arthritis and to provide a brief overview of the pathogenesis as it presented in a 33-year-old male with X-linked hypogammaglobulinemia/agammaglobulinema.

  10. Clinical and demographic characteristics and functional status of the patients with fibromyalgia syndrome

    PubMed Central

    Sahin, Nilay; Atik, Aziz; Dogan, Erdal

    2014-01-01

    OBJECTIVE: To investigate the clinical and demographic characteristics and functional status of the patients with fibromyalgia syndrome (FMS). METHODS: Ninety-four patients with the diagnosis of FMS were included in the study. All patients were evaluated with short form 36 for quality of life (SF-36), pain, depression, benign joint hypermobility syndrome (BJHS), myofacial pain syndrome (MPS), and demogrophic characteristics. End-point measurements were SF-36 for quality of life, visual analogue scale, Beck Depression Index, anamnesis, and physical examination. RESULTS: The majority of the patients were women who were suffering from generalised pain with a median age of 40.4. Mostly depression and sleep disorders were accompanying the syndrome. Physical examination revealed MPS and BJHS in most of the patients. CONCLUSION: BJHS and MPS must also be investigated in patients with the diagnosis of FMS. PMID:28058309

  11. Significance of cocaine history in schizophrenia.

    PubMed

    Sevy, S; Kay, S R; Opler, L A; van Praag, H M

    1990-10-01

    Fifty-one schizophrenic inpatients were divided into two groups, those with and without history of cocaine use, and compared on historical, demographic, cognitive, and psychopathological measures. Patients with a cocaine history were found to be significantly more depressed, less socialized, and more impaired in conceptual encoding and verbal memory, while less disordered in attention. The two groups did not differ in severity of illness or positive and negative syndromes. There were also no differences in control variables such as age, gender, education, intelligence, premorbid adjustment, neuroleptic dose, onset and chronicity of illness, continuity of hospitalization, paranoid subtype, and psychiatric illness in the family. Cocaine history was associated with multiple illicit drug use, but for other substances there was no increased liability for depression or cognitive deficits. The results suggest that the clinical presentation in schizophrenia is significantly associated with prior cocaine experience.

  12. Periprosthetic Joint Infections

    PubMed Central

    Lima, Ana Lucia L.; Oliveira, Priscila R.; Carvalho, Vladimir C.; Saconi, Eduardo S.; Cabrita, Henrique B.; Rodrigues, Marcelo B.

    2013-01-01

    Implantation of joint prostheses is becoming increasingly common, especially for the hip and knee. Infection is considered to be the most devastating of prosthesis-related complications, leading to prolonged hospitalization, repeated surgical intervention, and even definitive loss of the implant. The main risk factors to periprosthetic joint infections (PJIs) are advanced age, malnutrition, obesity, diabetes mellitus, HIV infection at an advanced stage, presence of distant infectious foci, and antecedents of arthroscopy or infection in previous arthroplasty. Joint prostheses can become infected through three different routes: direct implantation, hematogenic infection, and reactivation of latent infection. Gram-positive bacteria predominate in cases of PJI, mainly Staphylococcus aureus and Staphylococcus epidermidis. PJIs present characteristic signs that can be divided into acute and chronic manifestations. The main imaging method used in diagnosing joint prosthesis infections is X-ray. Computed tomography (CT) scan may assist in distinguishing between septic and aseptic loosening. Three-phase bone scintigraphy using technetium has high sensitivity, but low specificity. Positron emission tomography using fluorodeoxyglucose (FDG-PET) presents very divergent results in the literature. Definitive diagnosis of infection should be made by isolating the microorganism through cultures on material obtained from joint fluid puncturing, surgical wound secretions, surgical debridement procedures, or sonication fluid. Success in treating PJI depends on extensive surgical debridement and adequate and effective antibiotic therapy. Treatment in two stages using a spacer is recommended for most chronic infections in arthroplasty cases. Treatment in a single procedure is appropriate in carefully selected cases. PMID:24023542

  13. Distal radioulnar joint injuries

    PubMed Central

    Thomas, Binu P; Sreekanth, Raveendran

    2012-01-01

    Distal radioulnar joint is a trochoid joint relatively new in evolution. Along with proximal radioulnar joint, forearm bones and interosseous membrane, it allows pronosupination and load transmission across the wrist. Injuries around distal radioulnar joint are not uncommon, and are usually associated with distal radius fractures,fractures of the ulnar styloid and with the eponymous Galeazzi or Essex_Lopresti fractures. The injury can be purely involving the soft tissue especially the triangular fibrocartilage or the radioulnar ligaments. The patients usually present with ulnar sided wrist pain, features of instability, or restriction of rotation. Difficulty in carrying loads in the hand is a major constraint for these patients. Thorough clinical examination to localize point of tenderness and appropriate provocative tests help in diagnosis. Radiology and MRI are extremely useful, while arthroscopy is the gold standard for evaluation. The treatment protocols are continuously evolving and range from conservative, arthroscopic to open surgical methods. Isolated dislocation are uncommon. Basal fractures of the ulnar styloid tend to make the joint unstable and may require operative intervention. Chronic instability requires reconstruction of the stabilizing ligaments to avoid onset of arthritis. Prosthetic replacement in arthritis is gaining acceptance in the management of arthritis. PMID:23162140

  14. Temporomandibular joint disorders.

    PubMed

    Buescher, Jennifer J

    2007-11-15

    Temporomandibular joint disorders are common in adults; as many as one third of adults report having one or more symptoms, which include jaw or neck pain, headache, and clicking or grating within the joint. Most symptoms improve without treatment, but various noninvasive therapies may reduce pain for patients who have not experienced relief from self-care therapies. Physical therapy modalities (e.g., iontophoresis, phonophoresis), psychological therapies (e.g., cognitive behavior therapy), relaxation techniques, and complementary therapies (e.g., acupuncture, hypnosis) are all used for the treatment of temporomandibular joint disorders; however, no therapies have been shown to be uniformly superior for the treatment of pain or oral dysfunction. Noninvasive therapies should be attempted before pursuing invasive, permanent, or semi-permanent treatments that have the potential to cause irreparable harm. Dental occlusion therapy (e.g., oral splinting) is a common treatment for temporomandibular joint disorders, but a recent systematic review found insufficient evidence for or against its use. Some patients with intractable temporomandibular joint disorders develop chronic pain syndrome and may benefit from treatment, including antidepressants or cognitive behavior therapy.

  15. Dissimilar metals joint evaluation

    NASA Technical Reports Server (NTRS)

    Wakefield, M. E.; Apodaca, L. E.

    1974-01-01

    Dissimilar metals tubular joints between 2219-T851 aluminum alloy and 304L stainless steel were fabricated and tested to evaluate bonding processes. Joints were fabricated by four processes: (1) inertia (friction) weldings, where the metals are spun and forced together to create the weld; (2) explosive welding, where the metals are impacted together at high velocity; (3) co-extrusion, where the metals are extruded in contact at high temperature to promote diffusion; and (4) swaging, where residual stresses in the metals after a stretching operation maintain forced contact in mutual shear areas. Fifteen joints of each type were prepared and evaluated in a 6.35 cm (2.50 in.) O.D. size, with 0.32 cm (0.13 in.) wall thickness, and 7.6 cm (3.0 in) total length. The joints were tested to evaluate their ability to withstand pressure cycle, thermal cycle, galvanic corrosion and burst tests. Leakage tests and other non-destructive test techniques were used to evaluate the behavior of the joints, and the microstructure of the bond areas was analyzed.

  16. Human genetic data reveal contrasting demographic patterns between sedentary and nomadic populations that predate the emergence of farming.

    PubMed

    Aimé, Carla; Laval, Guillaume; Patin, Etienne; Verdu, Paul; Ségurel, Laure; Chaix, Raphaëlle; Hegay, Tatyana; Quintana-Murci, Lluis; Heyer, Evelyne; Austerlitz, Frédéric

    2013-12-01

    Demographic changes are known to leave footprints on genetic polymorphism. Together with the increased availability of large polymorphism data sets, coalescent-based methods allow inferring the past demography of populations from their present-day patterns of genetic diversity. Here, we analyzed both nuclear (20 noncoding regions) and mitochondrial (HVS-I) resequencing data to infer the demographic history of 66 African and Eurasian human populations presenting contrasting lifestyles (nomadic hunter-gatherers, nomadic herders, and sedentary farmers). This allowed us to investigate the relationship between lifestyle and demography and to address the long-standing debate about the chronology of demographic expansions and the Neolithic transition. In Africa, we inferred expansion events for farmers, but constant population sizes or contraction events for hunter-gatherers. In Eurasia, we inferred higher expansion rates for farmers than herders with HVS-I data, except in Central Asia and Korea. Although isolation and admixture processes could have impacted our demographic inferences, these processes alone seem unlikely to explain the contrasted demographic histories inferred in populations with different lifestyles. The small expansion rates or constant population sizes inferred for herders and hunter-gatherers may thus result from constraints linked to nomadism. However, autosomal data revealed contraction events for two sedentary populations in Eurasia, which may be caused by founder effects. Finally, the inferred expansions likely predated the emergence of agriculture and herding. This suggests that human populations could have started to expand in Paleolithic times, and that strong Paleolithic expansions in some populations may have ultimately favored their shift toward agriculture during the Neolithic.

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

    PubMed

    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.

  18. Assessing patterns of fish demographics and habitat in stream networks

    EPA Science Inventory

    Effective habitat restoration planning requires correctly anticipating demographic responses to altered habitats. New applications of Passive Integrated Transponder (PIT) tag technology to fish-habitat research have provided critical insights into fish movement, growth, and surv...

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

    PubMed

    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. The second demographic transition: A concise overview of its development

    PubMed Central

    Lesthaeghe, Ron

    2014-01-01

    This article gives a concise overview of the theoretical development of the concept of the “second demographic transition” since it was coined in 1986, its components, and its applicability, first to European populations and subsequently also to non-European societies as well. Both the demographic and the societal contrasts between the first demographic transition (FDT) and the second demographic transition (SDT) are highlighted. Then, the major criticisms of the SDT theory are outlined, and these issues are discussed in the light of the most recent developments in Europe, the United States, the Far East, and Latin America. It turns out that three major SDT patterns have developed and that these evolutions are contingent on much older systems of kinship and family organization. PMID:25453112