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Sample records for west-east admixed population

  1. Evidence that a West-East admixed population lived in the Tarim Basin as early as the early Bronze Age

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    Zhang Quanchao

    2010-02-01

    Full Text Available Abstract Background The Tarim Basin, located on the ancient Silk Road, played a very important role in the history of human migration and cultural communications between the West and the East. However, both the exact period at which the relevant events occurred and the origins of the people in the area remain very obscure. In this paper, we present data from the analyses of both Y chromosomal and mitochondrial DNA (mtDNA derived from human remains excavated from the Xiaohe cemetery, the oldest archeological site with human remains discovered in the Tarim Basin thus far. Results Mitochondrial DNA analysis showed that the Xiaohe people carried both the East Eurasian haplogroup (C and the West Eurasian haplogroups (H and K, whereas Y chromosomal DNA analysis revealed only the West Eurasian haplogroup R1a1a in the male individuals. Conclusion Our results demonstrated that the Xiaohe people were an admixture from populations originating from both the West and the East, implying that the Tarim Basin had been occupied by an admixed population since the early Bronze Age. To our knowledge, this is the earliest genetic evidence of an admixed population settled in the Tarim Basin.

  2. A population genetics model of linkage disequilibrium in admixed populations

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Understanding linkage disequilibrium (LD) created in admixed population and the rate of decay in the disequilibrium over evolution is an important subject in population genetics theory and in disease gene mapping in human populations. The present study represents the theoretical investigation of effects of gene frequencies, levels of LD and admixture proportions of donor populations on the evolutionary dynamics of the LD of the admixed population. We examined the conditions under which the admixed population reached linkage equilibrium or the peak level of the LD. The study reveals the inappropriateness in approximating the dynamics of the LD generated by population admixture by the commonly used formula in literature. An appropriate equation for the dynamics is proposed. The distinct feature of the newly suggested formula is that the value of the nonlinear component of the LD remains constant in the first generation of the population evolution. Comparison between the predicted disequilibrium dynamics shows that the error will be caused by using the old formula, and thus resulting in a misguidance in using the evolutionary information of the admixed population in gene mapping.

  3. New approaches to disease mapping in admixed populations.

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    Seldin, Michael F; Pasaniuc, Bogdan; Price, Alkes L

    2011-06-28

    Admixed populations such as African Americans and Hispanic Americans are often medically underserved and bear a disproportionately high burden of disease. Owing to the diversity of their genomes, these populations have both advantages and disadvantages for genetic studies of complex phenotypes. Advances in statistical methodologies that can infer genetic contributions from ancestral populations may yield new insights into the aetiology of disease and may contribute to the applicability of genomic medicine to these admixed population groups.

  4. Interethnic diversity of NAT2 polymorphisms in Brazilian admixed populations

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    Di Pietro Giuliano

    2010-10-01

    Full Text Available Abstract Background N-acetyltransferase type 2 (Nat2 is a phase II drug- metabolizing enzyme that plays a key role in the bioactivation of aromatic and heterocyclic amines. Its relevance in drug metabolism and disease susceptibility remains a central theme for pharmacogenetic research, mainly because of its genetic variability among human populations. In fact, the evolutionary and ethnic-specific SNPs on the NAT2 gene remain a focus for the potential discoveries in personalized drug therapy and genetic markers of diseases. Despite the wide characterization of NAT2 SNPs frequency in established ethnic groups, little data are available for highly admixed populations. In this context, five common NAT2 SNPs (G191A, C481T, G590A, A803G and G857A were investigated in a highly admixed population comprised of Afro-Brazilians, Whites, and Amerindians in northeastern Brazil. Thus, we sought to determine whether the distribution of NAT2 polymorphism is different among these three ethnic groups. Results Overall, there were no statistically significant differences in the distribution of NAT2 polymorphism when Afro-Brazilian and White groups were compared. Even the allele frequency of 191A, relatively common in African descendents, was not different between the Afro-Brazilian and White groups. However, allele and genotype frequencies of G590A were significantly higher in the Amerindian group than either in the Afro-Brazilian or White groups. Interestingly, a haplotype block between G590A and A803G was verified exclusively among Amerindians. Conclusions Our results indicate that ethnic admixture might contribute to a particular pattern of genetic diversity in the NAT2 gene and also offer new insights for the investigation of possible new NAT2 gene-environment effects in admixed populations.

  5. The behavior of admixed populations in neighbor-joining inference of population trees.

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    Kopelman, Naama M; Stone, Lewi; Gascuel, Olivier; Rosenberg, Noah A

    2013-01-01

    Neighbor-joining is one of the most widely used methods for constructing evolutionary trees. This approach from phylogenetics is often employed in population genetics, where distance matrices obtained from allele frequencies are used to produce a representation of population relationships in the form of a tree. In phylogenetics, the utility of neighbor-joining derives partly from a result that for a class of distance matrices including those that are additive or tree-like-generated by summing weights over the edges connecting pairs of taxa in a tree to obtain pairwise distances-application of neighbor-joining recovers exactly the underlying tree. For populations within a species, however, migration and admixture can produce distance matrices that reflect more complex processes than those obtained from the bifurcating trees typical in the multispecies context. Admixed populations-populations descended from recent mixture of groups that have long been separated-have been observed to be located centrally in inferred neighbor-joining trees, with short external branches incident to the path connecting their source populations. Here, using a simple model, we explore mathematically the behavior of an admixed population under neighbor-joining. We show that with an additive distance matrix, a population admixed among two source populations necessarily lies on the path between the sources. Relaxing the additivity requirement, we examine the smallest nontrivial case-four populations, one of which is admixed between two of the other three-showing that the two source populations never merge with each other before one of them merges with the admixed population. Furthermore, the distance on the constructed tree between the admixed population and either source population is always smaller than the distance between the source populations, and the external branch for the admixed population is always incident to the path connecting the sources. We define three properties that hold

  6. Facial asymmetry and genetic ancestry in Latin American admixed populations

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    Quinto Sanchez, Mirsha; Adhikari, Kaustubh; Acunã Alonzo, Víctor; Cintas, Célia; de Cerqueira, Caio Cesar Silva; Ramallo, Virgínia; Castillo, Lucia; Farrera, Alodi; Jaramillo, Claudia; Arias, Williams; Fuentes, Macarena; Everardo, Paola; Avila, Francisco de; Jorge A. Gómez Valdés; Hunemeier, Tábita

    2015-01-01

    Fluctuating and directional asymmetry are aspects of morphological variation widely used to infer environmental and genetic factors affecting facial phenotypes. However, the genetic basis and environmental determinants of both asymmetry types is far from being completely known. The analysis of facial asymmetries in admixed individuais can be of help to characterize the impact of a genome's heterozygosity on the deveiopmental basis of both fl.uctuating and directional asymmetries. Here we char...

  7. Detecting Heterogeneity in Population Structure Across the Genome in Admixed Populations.

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    McHugh, Caitlin; Brown, Lisa; Thornton, Timothy A

    2016-09-01

    The genetic structure of human populations is often characterized by aggregating measures of ancestry across the autosomal chromosomes. While it may be reasonable to assume that population structure patterns are similar genome-wide in relatively homogeneous populations, this assumption may not be appropriate for admixed populations, such as Hispanics and African-Americans, with recent ancestry from two or more continents. Recent studies have suggested that systematic ancestry differences can arise at genomic locations in admixed populations as a result of selection and nonrandom mating. Here, we propose a method, which we refer to as the chromosomal ancestry differences (CAnD) test, for detecting heterogeneity in population structure across the genome. CAnD can incorporate either local or chromosome-wide ancestry inferred from SNP genotype data to identify chromosomes harboring genomic regions with ancestry contributions that are significantly different than expected. In simulation studies with real genotype data from phase III of the HapMap Project, we demonstrate the validity and power of CAnD. We apply CAnD to the HapMap Mexican-American (MXL) and African-American (ASW) population samples; in this analysis the software RFMix is used to infer local ancestry at genomic regions, assuming admixing from Europeans, West Africans, and Native Americans. The CAnD test provides strong evidence of heterogeneity in population structure across the genome in the MXL sample ([Formula: see text]), which is largely driven by elevated Native American ancestry and deficit of European ancestry on the X chromosomes. Among the ASW, all chromosomes are largely African derived and no heterogeneity in population structure is detected in this sample.

  8. The role of local ancestry adjustment in association studies using admixed populations.

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    Zhang, Jianqi; Stram, Daniel O

    2014-09-01

    Association analysis using admixed populations imposes challenges and opportunities for disease mapping. By developing some explicit results for the variance of an allele of interest conditional on either local or global ancestry and by simulation of recently admixed genomes we evaluate power and false-positive rates under a variety of scenarios concerning linkage disequilibrium (LD) and the presence of unmeasured variants. Pairwise LD patterns were compared between admixed and nonadmixed populations using the HapMap phase 3 data. Based on the above, we showed that as follows: For causal variants with similar effect size in all populations, power is generally higher in a study using admixed population than using nonadmixed population, especially for highly differentiated SNPs. This gain of power is achieved with adjustment of global ancestry, which completely removes any cross-chromosome inflation of type I error rates, and addresses much of the intrachromosome inflation. If reliably estimated, adjusting for local ancestry precisely recovers the localization that could have been achieved in a stratified analysis of source populations. Improved localization is most evident for highly differentiated SNPs; however, the advantage of higher power is lost on exactly the same differentiated SNPs. In the real admixed populations such as African Americans and Latinos, the expansion of LD is not as dramatic as in our simulation. While adjustment for global ancestry is required prior to announcing a novel association seen in an admixed population, local ancestry adjustment may best be regarded as a localization tool not strictly required for discovery purposes. © 2014 WILEY PERIODICALS, INC.

  9. Outlining the Ancestry Landscape of Colombian Admixed Populations

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    Ossa, Humberto; Aquino, Juliana; Pereira, Rui; Ibarra, Adriana; Ossa, Rafael H; Pérez, Luz Adriana; Granda, Juan David; Lattig, Maria Claudia; Groot, Helena; Fagundes de Carvalho, Elizeu; Gusmão, Leonor

    2016-01-01

    The ancestry of the Colombian population comprises a large number of well differentiated Native communities belonging to diverse linguistic groups. In the late fifteenth century, a process of admixture was initiated with the arrival of the Europeans, and several years later, Africans also became part of the Colombian population. Therefore, the genepool of the current Colombian population results from the admixture of Native Americans, Europeans and Africans. This admixture occurred differently in each region of the country, producing a clearly stratified population. Considering the importance of population substructure in both clinical and forensic genetics, we sought to investigate and compare patterns of genetic ancestry in Colombia by studying samples from Native and non-Native populations living in its 5 continental regions: the Andes, Caribe, Amazonia, Orinoquía, and Pacific regions. For this purpose, 46 AIM-Indels were genotyped in 761 non-related individuals from current populations. Previously published genotype data from 214 Colombian Natives from five communities were used for population comparisons. Significant differences were observed between Native and non-Native populations, among non-Native populations from different regions and among Native populations from different ethnic groups. The Pacific was the region with the highest African ancestry, Amazonia harboured the highest Native ancestry and the Andean and Orinoquían regions showed the highest proportion of European ancestry. The Andean region was further sub-divided into 6 sub-regions: North East, Central West, Central East, West, South West and South East. Among these regions, the South West region showed a significantly lower European admixture than the other regions. Hardy-Weinberg equilibrium and variance values of ancestry among individuals within populations showed a potential stratification of the Pacific population. PMID:27736937

  10. A Continuous Correlated Beta Process Model for Genetic Ancestry in Admixed Populations.

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    Gompert, Zachariah

    2016-01-01

    Admixture and recombination create populations and genomes with genetic ancestry from multiple source populations. Analyses of genetic ancestry in admixed populations are relevant for trait and disease mapping, studies of speciation, and conservation efforts. Consequently, many methods have been developed to infer genome-average ancestry and to deconvolute ancestry into continuous local ancestry blocks or tracts within individuals. Current methods for local ancestry inference perform well when admixture occurred recently or hybridization is ongoing, or when admixture occurred in the distant past such that local ancestry blocks have fixed in the admixed population. However, methods to infer local ancestry frequencies in isolated admixed populations still segregating for ancestry do not exist. In the current paper, I develop and test a continuous correlated beta process model to fill this analytical gap. The method explicitly models autocorrelations in ancestry frequencies at the population-level and uses discriminant analysis of SNP windows to take advantage of ancestry blocks within individuals. Analyses of simulated data sets show that the method is generally accurate such that ancestry frequency estimates exhibited low root-mean-square error and were highly correlated with the true values, particularly when large (±10 or ±20) SNP windows were used. Along these lines, the proposed method outperformed post hoc inference of ancestry frequencies from a traditional hidden Markov model (i.e., the linkage model in structure), particularly when admixture occurred more distantly in the past with little on-going gene flow or was followed by natural selection. The reliability and utility of the method was further assessed by analyzing genetic ancestry in an admixed human population (Uyghur) and three populations from a hybrid zone between Mus domesticus and M. musculus. Considerable variation in ancestry frequencies was detected within and among chromosomes in the Uyghur

  11. Autosomal admixture levels are informative about sex bias in admixed populations.

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    Goldberg, Amy; Verdu, Paul; Rosenberg, Noah A

    2014-11-01

    Sex-biased admixture has been observed in a wide variety of admixed populations. Genetic variation in sex chromosomes and functions of quantities computed from sex chromosomes and autosomes have often been examined to infer patterns of sex-biased admixture, typically using statistical approaches that do not mechanistically model the complexity of a sex-specific history of admixture. Here, expanding on a model of Verdu and Rosenberg (2011) that did not include sex specificity, we develop a model that mechanistically examines sex-specific admixture histories. Under the model, multiple source populations contribute to an admixed population, potentially with their male and female contributions varying over time. In an admixed population descended from two source groups, we derive the moments of the distribution of the autosomal admixture fraction from a specific source population as a function of sex-specific introgression parameters and time. Considering admixture processes that are constant in time, we demonstrate that surprisingly, although the mean autosomal admixture fraction from a specific source population does not reveal a sex bias in the admixture history, the variance of autosomal admixture is informative about sex bias. Specifically, the long-term variance decreases as the sex bias from a contributing source population increases. This result can be viewed as analogous to the reduction in effective population size for populations with an unequal number of breeding males and females. Our approach suggests that it may be possible to use the effect of sex-biased admixture on autosomal DNA to assist with methods for inference of the history of complex sex-biased admixture processes.

  12. Genetic variants of TSLP and asthma in an admixed urban population.

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    Mengling Liu

    Full Text Available BACKGROUND: Thymic stromal lymphopoietin (TSLP, an IL7-like cytokine produced by bronchial epithelial cells is upregulated in asthma and induces dendritic cell maturation supporting a Th2 response. Environmental pollutants, including tobacco smoke and diesel exhaust particles upregulate TSLP suggesting that TSLP may be an interface between environmental pollution and immune responses in asthma. Since asthma is prevalent in urban communities, variants in the TSLP gene may be important in asthma susceptibility in these populations. OBJECTIVES: To determine whether genetic variants in TSLP are associated with asthma in an urban admixed population. METHODOLOGY AND MAIN RESULTS: Ten tag-SNPs in the TSLP gene were analyzed for association with asthma using 387 clinically diagnosed asthmatic cases and 212 healthy controls from an urban admixed population. One SNP (rs1898671 showed nominally significant association with asthma (odds ratio (OR = 1.50; 95% confidence interval (95% CI: 1.09-2.05, p = 0.01 after adjusting for age, BMI, income, education and population stratification. Association results were consistent using two different approaches to adjust for population stratification. When stratified by smoking status, the same SNP showed a significantly increased risk associated with asthma in ex-smokers (OR = 2.00, 95% CI: 1.04-3.83, p = 0.04 but not significant in never-smokers (OR = 1.34; 95% CI: 0.93-1.94, p = 0.11. Haplotype-specific score test indicated that an elevated risk for asthma was associated with a specific haplotype of TSLP involving SNP rs1898671 (OR = 1.58, 95% CI: 1.10-2.27, p = 0.01. Association of this SNP with asthma was confirmed in an independent large population-based cohort consortium study (OR = 1.15, 95% CI: 1.07-1.23, p = 0.0003 and the results stratified by smoking status were also validated (ex-smokers: OR = 1.21, 95% CI: 1.08-1.34, p = 0.003; never-smokers: OR = 1

  13. Genetic structure of a unique admixed population: implications for medical research.

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    Patterson, Nick; Petersen, Desiree C; van der Ross, Richard E; Sudoyo, Herawati; Glashoff, Richard H; Marzuki, Sangkot; Reich, David; Hayes, Vanessa M

    2010-02-01

    STATEMENT: In naming population groups, we think a chief aim is to use terms that the group members use themselves, or find familiar and comfortable. The terms used in this manuscript to describe populations are as historically correct as possible and are chosen so as not to offend any population group. Two of the authors (DCP and REvdR) belong to the Coloured population, with one of the authors (REvdR) having contributed extensively to current literature on the history of the Coloured people of South Africa and served as Vice-President of the South African Institute of Race Relations. According to the 2001 South African census (http://www.statssa.gov.za/census01/HTML/CInBrief/CIB2001.pdf), "Statistics South Africa continues to classify people by population group, in order to monitor progress in moving away from the apartheid-based discrimination of the past. However, membership of a population group is now based on self-perception and self-classification, not on a legal definition. Five options were provided on the questionnaire, Black African, Coloured, Indian or Asian, White and Other. Responses in the category 'Other' were very few and were therefore imputed". We have elected to use the term Bushmen rather than San to refer to the hunter-gatherer people of Southern Africa. Although they have no collective name for themselves, this decision was based on the term Bushmen (or Bossiesman) being the more familiar to the communities themselves, while the term San is the more accepted academic classification. Understanding human genetic structure has fundamental implications for understanding the evolution and impact of human diseases. In this study, we describe the complex genetic substructure of a unique and recently admixed population arising approximately 350 years ago as a direct result of European settlement in South Africa. Analysis was performed using over 900 000 genome-wide single nucleotide polymorphisms in 20 unrelated ancestry-informative marker selected

  14. Sensitive detection of chromosomal segments of distinct ancestry in admixed populations.

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    Alkes L Price

    2009-06-01

    Full Text Available Identifying the ancestry of chromosomal segments of distinct ancestry has a wide range of applications from disease mapping to learning about history. Most methods require the use of unlinked markers; but, using all markers from genome-wide scanning arrays, it should in principle be possible to infer the ancestry of even very small segments with exquisite accuracy. We describe a method, HAPMIX, which employs an explicit population genetic model to perform such local ancestry inference based on fine-scale variation data. We show that HAPMIX outperforms other methods, and we explore its utility for inferring ancestry, learning about ancestral populations, and inferring dates of admixture. We validate the method empirically by applying it to populations that have experienced recent and ancient admixture: 935 African Americans from the United States and 29 Mozabites from North Africa. HAPMIX will be of particular utility for mapping disease genes in recently admixed populations, as its accurate estimates of local ancestry permit admixture and case-control association signals to be combined, enabling more powerful tests of association than with either signal alone.

  15. Butyrylcholinesterase polymorphisms (BCHE and CHE2 loci) in Brazilian Indian and admixed populations.

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    Alcântara, V M; De Lourenço, M A; Salzano, F M; Petzl-Erler, M L; Coimbra, C E; Santos, R V; Chautard-Freire-Maia, E A

    1995-10-01

    The genetic variability of butyrylcholinesterase, determined by the BCHE and CHE2 loci, was examined in nine Brazilian Indian groups. In addition, a search for the presence of the BCHE*F allele was also performed in eight other Brazilian Indian samples and in five admixed (black-Indian-white) rural Amazonian communities previously studied for the CHE2 locus and the BCHE*A allele. In the Indian populations the frequency of the BCHE*F allele varied from 0 to 7.1% +/- 3.4 and the frequency of the CHE2 C5+ phenotype ranged from 1.4% +/- 1.4 to 45.9% +/- 3.8. This study seems to be the first to report the presence of the BCHE*F allele in native Americans. The BCHE*A allele appeared in one Indian group (1.4% +/- 1.0), and we suggest that its existence in this tribe and in other native Americans can be explained by gene flow from white populations. Gene flow may also be the reason for the occurrence of the BCHE*F allele in Brazilian Indians, whereas the CHE2*C5+ allele may have been present in the paleo-Indians. The distributions of both the BCHE*F allele and the CHE2 C5+ phenotype in Brazilian Indians seem to be the result of the action of random genetic drift.

  16. PETROCHINA WEST EAST GAS PIPELINE & SALES COMPANY

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ PetroChina West East Gas Pipeline & Sales Company, a regional company directly under PetroChina Company Limited (PetroChina), is responsible for the construction and operation of the West-East Gas Pipeline Project, and the gas marketing and sales of the natural gas market in China.

  17. Enhanced statistical tests for GWAS in admixed populations: assessment using African Americans from CARe and a Breast Cancer Consortium.

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    Bogdan Pasaniuc

    2011-04-01

    Full Text Available While genome-wide association studies (GWAS have primarily examined populations of European ancestry, more recent studies often involve additional populations, including admixed populations such as African Americans and Latinos. In admixed populations, linkage disequilibrium (LD exists both at a fine scale in ancestral populations and at a coarse scale (admixture-LD due to chromosomal segments of distinct ancestry. Disease association statistics in admixed populations have previously considered SNP association (LD mapping or admixture association (mapping by admixture-LD, but not both. Here, we introduce a new statistical framework for combining SNP and admixture association in case-control studies, as well as methods for local ancestry-aware imputation. We illustrate the gain in statistical power achieved by these methods by analyzing data of 6,209 unrelated African Americans from the CARe project genotyped on the Affymetrix 6.0 chip, in conjunction with both simulated and real phenotypes, as well as by analyzing the FGFR2 locus using breast cancer GWAS data from 5,761 African-American women. We show that, at typed SNPs, our method yields an 8% increase in statistical power for finding disease risk loci compared to the power achieved by standard methods in case-control studies. At imputed SNPs, we observe an 11% increase in statistical power for mapping disease loci when our local ancestry-aware imputation framework and the new scoring statistic are jointly employed. Finally, we show that our method increases statistical power in regions harboring the causal SNP in the case when the causal SNP is untyped and cannot be imputed. Our methods and our publicly available software are broadly applicable to GWAS in admixed populations.

  18. Enhanced statistical tests for GWAS in admixed populations: assessment using African Americans from CARe and a Breast Cancer Consortium.

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    Pasaniuc, Bogdan; Zaitlen, Noah; Lettre, Guillaume; Chen, Gary K; Tandon, Arti; Kao, W H Linda; Ruczinski, Ingo; Fornage, Myriam; Siscovick, David S; Zhu, Xiaofeng; Larkin, Emma; Lange, Leslie A; Cupples, L Adrienne; Yang, Qiong; Akylbekova, Ermeg L; Musani, Solomon K; Divers, Jasmin; Mychaleckyj, Joe; Li, Mingyao; Papanicolaou, George J; Millikan, Robert C; Ambrosone, Christine B; John, Esther M; Bernstein, Leslie; Zheng, Wei; Hu, Jennifer J; Ziegler, Regina G; Nyante, Sarah J; Bandera, Elisa V; Ingles, Sue A; Press, Michael F; Chanock, Stephen J; Deming, Sandra L; Rodriguez-Gil, Jorge L; Palmer, Cameron D; Buxbaum, Sarah; Ekunwe, Lynette; Hirschhorn, Joel N; Henderson, Brian E; Myers, Simon; Haiman, Christopher A; Reich, David; Patterson, Nick; Wilson, James G; Price, Alkes L

    2011-04-01

    While genome-wide association studies (GWAS) have primarily examined populations of European ancestry, more recent studies often involve additional populations, including admixed populations such as African Americans and Latinos. In admixed populations, linkage disequilibrium (LD) exists both at a fine scale in ancestral populations and at a coarse scale (admixture-LD) due to chromosomal segments of distinct ancestry. Disease association statistics in admixed populations have previously considered SNP association (LD mapping) or admixture association (mapping by admixture-LD), but not both. Here, we introduce a new statistical framework for combining SNP and admixture association in case-control studies, as well as methods for local ancestry-aware imputation. We illustrate the gain in statistical power achieved by these methods by analyzing data of 6,209 unrelated African Americans from the CARe project genotyped on the Affymetrix 6.0 chip, in conjunction with both simulated and real phenotypes, as well as by analyzing the FGFR2 locus using breast cancer GWAS data from 5,761 African-American women. We show that, at typed SNPs, our method yields an 8% increase in statistical power for finding disease risk loci compared to the power achieved by standard methods in case-control studies. At imputed SNPs, we observe an 11% increase in statistical power for mapping disease loci when our local ancestry-aware imputation framework and the new scoring statistic are jointly employed. Finally, we show that our method increases statistical power in regions harboring the causal SNP in the case when the causal SNP is untyped and cannot be imputed. Our methods and our publicly available software are broadly applicable to GWAS in admixed populations.

  19. Genetic architecture of skin and eye color in an African-European admixed population.

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    Sandra Beleza

    2013-03-01

    Full Text Available Variation in human skin and eye color is substantial and especially apparent in admixed populations, yet the underlying genetic architecture is poorly understood because most genome-wide studies are based on individuals of European ancestry. We study pigmentary variation in 699 individuals from Cape Verde, where extensive West African/European admixture has given rise to a broad range in trait values and genomic ancestry proportions. We develop and apply a new approach for measuring eye color, and identify two major loci (HERC2[OCA2] P = 2.3 × 10(-62, SLC24A5 P = 9.6 × 10(-9 that account for both blue versus brown eye color and varying intensities of brown eye color. We identify four major loci (SLC24A5 P = 5.4 × 10(-27, TYR P = 1.1 × 10(-9, APBA2[OCA2] P = 1.5 × 10(-8, SLC45A2 P = 6 × 10(-9 for skin color that together account for 35% of the total variance, but the genetic component with the largest effect (~44% is average genomic ancestry. Our results suggest that adjacent cis-acting regulatory loci for OCA2 explain the relationship between skin and eye color, and point to an underlying genetic architecture in which several genes of moderate effect act together with many genes of small effect to explain ~70% of the estimated heritability.

  20. Estimating ancestral proportions in a multi-ethnic US sample: implications for studies of admixed populations

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    Levran Orna

    2012-07-01

    Full Text Available Abstract This study was designed to determine the ancestral composition of a multi-ethnic sample collected for studies of drug addictions in New York City and Las Vegas, and to examine the reliability of self-identified ethnicity and three-generation family history data. Ancestry biographical scores for seven clusters corresponding to world major geographical regions were obtained using STRUCTURE, based on genotypes of 168 ancestry informative markers (AIMs, for a sample of 1,291 African Americans (AA, European Americans (EA, and Hispanic Americans (HA along with data from 1,051 HGDP-CEPH ‘diversity panel’ as a reference. Self-identified ethnicity and family history data, obtained in an interview, were accurate in identifying the individual major ancestry in the AA and the EA samples (approximately 99% and 95%, respectively but were not useful for the HA sample and could not predict the extent of admixture in any group. The mean proportions of the combined clusters corresponding to European and Middle Eastern populations in the AA sample, revealed by AIMs analysis, were 0.13. The HA subjects, predominantly Puerto Ricans, showed a highly variable hybrid contribution pattern of clusters corresponding to Europe (0.27, Middle East (0.27, Africa (0.20, and Central Asia (0.14. The effect of admixture on allele frequencies is demonstrated for two single-nucleotide polymorphisms (118A > G, 17 C > T of the mu opioid receptor gene (OPRM1. This study reiterates the importance of AIMs in defining ancestry, especially in admixed populations.

  1. Exome Sequencing in an Admixed Isolated Population Indicates NFXL1 Variants Confer a Risk for Specific Language Impairment

    Science.gov (United States)

    Villanueva, Pía; Nudel, Ron; Hoischen, Alexander; Fernández, María Angélica; Simpson, Nuala H.; Gilissen, Christian; Reader, Rose H.; Jara, Lillian; Echeverry, Maria Magdalena; Francks, Clyde; Baird, Gillian; Conti-Ramsden, Gina; O’Hare, Anne; Bolton, Patrick F.; Hennessy, Elizabeth R.; Palomino, Hernán; Carvajal-Carmona, Luis; Veltman, Joris A.; Cazier, Jean-Baptiste; De Barbieri, Zulema

    2015-01-01

    Children affected by Specific Language Impairment (SLI) fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic techniques to investigate an admixed isolated founder population from the Robinson Crusoe Island (Chile), who are affected by a high incidence of SLI, increasing the power to discover contributory genetic factors. We utilize exome sequencing in selected individuals from this population to identify eight coding variants that are of putative significance. We then apply association analyses across the wider population to highlight a single rare coding variant (rs144169475, Minor Allele Frequency of 4.1% in admixed South American populations) in the NFXL1 gene that confers a nonsynonymous change (N150K) and is significantly associated with language impairment in the Robinson Crusoe population (p = 2.04 × 10–4, 8 variants tested). Subsequent sequencing of NFXL1 in 117 UK SLI cases identified four individuals with heterozygous variants predicted to be of functional consequence. We conclude that coding variants within NFXL1 confer an increased risk of SLI within a complex genetic model. PMID:25781923

  2. Exome sequencing in an admixed isolated population indicates NFXL1 variants confer a risk for specific language impairment.

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    Pía Villanueva

    2015-03-01

    Full Text Available Children affected by Specific Language Impairment (SLI fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic techniques to investigate an admixed isolated founder population from the Robinson Crusoe Island (Chile, who are affected by a high incidence of SLI, increasing the power to discover contributory genetic factors. We utilize exome sequencing in selected individuals from this population to identify eight coding variants that are of putative significance. We then apply association analyses across the wider population to highlight a single rare coding variant (rs144169475, Minor Allele Frequency of 4.1% in admixed South American populations in the NFXL1 gene that confers a nonsynonymous change (N150K and is significantly associated with language impairment in the Robinson Crusoe population (p = 2.04 × 10-4, 8 variants tested. Subsequent sequencing of NFXL1 in 117 UK SLI cases identified four individuals with heterozygous variants predicted to be of functional consequence. We conclude that coding variants within NFXL1 confer an increased risk of SLI within a complex genetic model.

  3. Exome sequencing in an admixed isolated population indicates NFXL1 variants confer a risk for specific language impairment.

    Science.gov (United States)

    Villanueva, Pía; Nudel, Ron; Hoischen, Alexander; Fernández, María Angélica; Simpson, Nuala H; Gilissen, Christian; Reader, Rose H; Jara, Lillian; Echeverry, María Magdalena; Echeverry, Maria Magdalena; Francks, Clyde; Baird, Gillian; Conti-Ramsden, Gina; O'Hare, Anne; Bolton, Patrick F; Hennessy, Elizabeth R; Palomino, Hernán; Carvajal-Carmona, Luis; Veltman, Joris A; Cazier, Jean-Baptiste; De Barbieri, Zulema; Fisher, Simon E; Newbury, Dianne F

    2015-03-01

    Children affected by Specific Language Impairment (SLI) fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic techniques to investigate an admixed isolated founder population from the Robinson Crusoe Island (Chile), who are affected by a high incidence of SLI, increasing the power to discover contributory genetic factors. We utilize exome sequencing in selected individuals from this population to identify eight coding variants that are of putative significance. We then apply association analyses across the wider population to highlight a single rare coding variant (rs144169475, Minor Allele Frequency of 4.1% in admixed South American populations) in the NFXL1 gene that confers a nonsynonymous change (N150K) and is significantly associated with language impairment in the Robinson Crusoe population (p = 2.04 × 10-4, 8 variants tested). Subsequent sequencing of NFXL1 in 117 UK SLI cases identified four individuals with heterozygous variants predicted to be of functional consequence. We conclude that coding variants within NFXL1 confer an increased risk of SLI within a complex genetic model.

  4. Several different lactase persistence associated alleles and high diversity of the lactase gene in the admixed Brazilian population.

    Science.gov (United States)

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

    2012-01-01

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

  5. Several different lactase persistence associated alleles and high diversity of the lactase gene in the admixed Brazilian population.

    Directory of Open Access Journals (Sweden)

    Deise C Friedrich

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

  6. Socioeconomic and nutritional factors account for the association of gastric cancer with Amerindian ancestry in a Latin American admixed population.

    Science.gov (United States)

    Pereira, Latife; Zamudio, Roxana; Soares-Souza, Giordano; Herrera, Phabiola; Cabrera, Lilia; Hooper, Catherine C; Cok, Jaime; Combe, Juan M; Vargas, Gloria; Prado, William A; Schneider, Silvana; Kehdy, Fernanda; Rodrigues, Maira R; Chanock, Stephen J; Berg, Douglas E; Gilman, Robert H; Tarazona-Santos, Eduardo

    2012-01-01

    Gastric cancer is one of the most lethal types of cancer and its incidence varies worldwide, with the Andean region of South America showing high incidence rates. We evaluated the genetic structure of the population from Lima (Peru) and performed a case-control genetic association study to test the contribution of African, European, or Native American ancestry to risk for gastric cancer, controlling for the effect of non-genetic factors. A wide set of socioeconomic, dietary, and clinic information was collected for each participant in the study and ancestry was estimated based on 103 ancestry informative markers. Although the urban population from Lima is usually considered as mestizo (i.e., admixed from Africans, Europeans, and Native Americans), we observed a high fraction of Native American ancestry (78.4% for the cases and 74.6% for the controls) and a very low African ancestry (gastric cancer, but socioeconomic factors associated both with gastric cancer and Native American ethnicity account for this association. Therefore, the high incidence of gastric cancer in Peru does not seem to be related to susceptibility alleles common in this population. Instead, our result suggests a predominant role for ethnic-associated socioeconomic factors and disparities in access to health services. Since Native Americans are a neglected group in genomic studies, we suggest that the population from Lima and other large cities from Western South America with high Native American ancestry background may be convenient targets for epidemiological studies focused on this ethnic group.

  7. Socioeconomic and nutritional factors account for the association of gastric cancer with Amerindian ancestry in a Latin American admixed population.

    Directory of Open Access Journals (Sweden)

    Latife Pereira

    Full Text Available Gastric cancer is one of the most lethal types of cancer and its incidence varies worldwide, with the Andean region of South America showing high incidence rates. We evaluated the genetic structure of the population from Lima (Peru and performed a case-control genetic association study to test the contribution of African, European, or Native American ancestry to risk for gastric cancer, controlling for the effect of non-genetic factors. A wide set of socioeconomic, dietary, and clinic information was collected for each participant in the study and ancestry was estimated based on 103 ancestry informative markers. Although the urban population from Lima is usually considered as mestizo (i.e., admixed from Africans, Europeans, and Native Americans, we observed a high fraction of Native American ancestry (78.4% for the cases and 74.6% for the controls and a very low African ancestry (<5%. We determined that higher Native American individual ancestry is associated with gastric cancer, but socioeconomic factors associated both with gastric cancer and Native American ethnicity account for this association. Therefore, the high incidence of gastric cancer in Peru does not seem to be related to susceptibility alleles common in this population. Instead, our result suggests a predominant role for ethnic-associated socioeconomic factors and disparities in access to health services. Since Native Americans are a neglected group in genomic studies, we suggest that the population from Lima and other large cities from Western South America with high Native American ancestry background may be convenient targets for epidemiological studies focused on this ethnic group.

  8. Socioeconomic and Nutritional Factors Account for the Association of Gastric Cancer with Amerindian Ancestry in a Latin American Admixed Population

    Science.gov (United States)

    Pereira, Latife; Zamudio, Roxana; Soares-Souza, Giordano; Herrera, Phabiola; Cabrera, Lilia; Hooper, Catherine C.; Cok, Jaime; Combe, Juan M.; Vargas, Gloria; Prado, William A.; Schneider, Silvana; Kehdy, Fernanda; Rodrigues, Maira R.; Chanock, Stephen J.; Berg, Douglas E.; Gilman, Robert H.; Tarazona-Santos, Eduardo

    2012-01-01

    Gastric cancer is one of the most lethal types of cancer and its incidence varies worldwide, with the Andean region of South America showing high incidence rates. We evaluated the genetic structure of the population from Lima (Peru) and performed a case-control genetic association study to test the contribution of African, European, or Native American ancestry to risk for gastric cancer, controlling for the effect of non-genetic factors. A wide set of socioeconomic, dietary, and clinic information was collected for each participant in the study and ancestry was estimated based on 103 ancestry informative markers. Although the urban population from Lima is usually considered as mestizo (i.e., admixed from Africans, Europeans, and Native Americans), we observed a high fraction of Native American ancestry (78.4% for the cases and 74.6% for the controls) and a very low African ancestry (<5%). We determined that higher Native American individual ancestry is associated with gastric cancer, but socioeconomic factors associated both with gastric cancer and Native American ethnicity account for this association. Therefore, the high incidence of gastric cancer in Peru does not seem to be related to susceptibility alleles common in this population. Instead, our result suggests a predominant role for ethnic-associated socioeconomic factors and disparities in access to health services. Since Native Americans are a neglected group in genomic studies, we suggest that the population from Lima and other large cities from Western South America with high Native American ancestry background may be convenient targets for epidemiological studies focused on this ethnic group. PMID:22870209

  9. Comparison of Genome-Wide Association Methods in Analyses of Admixed Populations with Complex Familial Relationships

    DEFF Research Database (Denmark)

    Kadri, Naveen; Guldbrandtsen, Bernt; Sørensen, Peter;

    2014-01-01

    ) levels. We also compared type-I error rates among models in analyses of publicly available human and dog datasets. The models corrected for none, one, or both structure levels. Correction for K was performed with linear mixed models incorporating familial relationships estimated from pedigrees or genetic......Population structure is known to cause false-positive detection in association studies. We compared the power, precision, and type-I error rates of various association models in analyses of a simulated dataset with structure at the population (admixture from two populations; P) and family (K...... corrected for P. In contrast, correction for P alone in linear models was insufficient. The power and precision of linear mixed models with and without correction for P were similar. Furthermore, power, precision, and type-I error rate were comparable in linear mixed models incorporating pedigree...

  10. Haplotype diversity of 17 Y-str loci in an admixed population from the Brazilian Amazon

    Science.gov (United States)

    Francez, Pablo Abdon da Costa; Ramos, Luiz Patrick Vidal; de Jesus Brabo Ferreira Palha, Teresinha; dos Santos, Sidney Emanuel Batista

    2012-01-01

    The allelic and haplotype frequencies of 17 Y-STR loci most commonly used in forensic testing were estimated in a sample of 138 unrelated healthy males from Macapá, in the northern Amazon region of Brazil. The average gene diversity was 0.6554 ± 0.3315. 134 haplotypes of the 17 loci were observed, 130 of them unique and four present in two individuals each. The haplotype diversity index was 0.9996 + 0.0009, with the most frequent haplogroups being R1b (52.2%), E1b1b (11.6%), J2 (10.1%) and Q (7.2%). Most haplogroups of this population belonged to European male lineages (89.2%), followed by Amerindian (7.2%) and African (3.6%) lineages. PMID:22481873

  11. Detection of ancestry informative HLA alleles confirms the admixed origins of Japanese population.

    Science.gov (United States)

    Nakaoka, Hirofumi; Mitsunaga, Shigeki; Hosomichi, Kazuyoshi; Shyh-Yuh, Liou; Sawamoto, Taiji; Fujiwara, Tsutomu; Tsutsui, Naohisa; Suematsu, Koji; Shinagawa, Akira; Inoko, Hidetoshi; Inoue, Ituro

    2013-01-01

    The polymorphisms in the human leukocyte antigen (HLA) region are powerful tool for studying human evolutionary processes. We investigated genetic structure of Japanese by using five-locus HLA genotypes (HLA-A, -B, -C, -DRB1, and -DPB1) of 2,005 individuals from 10 regions of Japan. We found a significant level of population substructure in Japanese; particularly the differentiation between Okinawa Island and mainland Japanese. By using a plot of the principal component scores, we identified ancestry informative alleles associated with the underlying population substructure. We examined extent of linkage disequilibrium (LD) between pairs of HLA alleles on the haplotypes that were differentiated among regions. The LDs were strong and weak for pairs of HLA alleles characterized by low and high frequencies in Okinawa Island, respectively. The five-locus haplotypes whose alleles exhibit strong LD were unique to Japanese and South Korean, suggesting that these haplotypes had been recently derived from the Korean Peninsula. The alleles characterized by high frequency in Japanese compared to South Korean formed segmented three-locus haplotype that was commonly found in Aleuts, Eskimos, and North- and Meso-Americans but not observed in Korean and Chinese. The serologically equivalent haplotype was found in Orchid Island in Taiwan, Mongol, Siberia, and Arctic regions. It suggests that early Japanese who existed prior to the migration wave from the Korean Peninsula shared ancestry with northern Asian who moved to the New World via the Bering Strait land bridge. These results may support the admixture model for peopling of Japanese Archipelago.

  12. HLA class I and class II conserved extended haplotypes and their fragments or blocks in Mexicans: implications for the study of genetic diversity in admixed populations.

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    Joaquín Zúñiga

    Full Text Available Major histocompatibility complex (MHC genes are highly polymorphic and informative in disease association, transplantation, and population genetics studies with particular importance in the understanding of human population diversity and evolution. The aim of this study was to describe the HLA diversity in Mexican admixed individuals. We studied the polymorphism of MHC class I (HLA-A, -B, -C, and class II (HLA-DRB1, -DQB1 genes using high-resolution sequence based typing (SBT method and we structured the blocks and conserved extended haplotypes (CEHs in 234 non-related admixed Mexican individuals (468 haplotypes by a maximum likelihood method. We found that HLA blocks and CEHs are primarily from Amerindian and Caucasian origin, with smaller participation of African and recent Asian ancestry, demonstrating a great diversity of HLA blocks and CEHs in Mexicans from the central area of Mexico. We also analyzed the degree of admixture in this group using short tandem repeats (STRs and HLA-B that correlated with the frequency of most probable ancestral HLA-C/-B and -DRB1/-DQB1 blocks and CEHs. Our results contribute to the analysis of the diversity and ancestral contribution of HLA class I and HLA class II alleles and haplotypes of Mexican admixed individuals from Mexico City. This work will help as a reference to improve future studies in Mexicans regarding allotransplantation, immune responses and disease associations.

  13. IL28B polymorphisms are markers of therapy response and are influenced by genetic ancestry in chronic hepatitis C patients from an admixed population.

    Science.gov (United States)

    Cavalcante, Lourianne N; Abe-Sandes, Kiyoko; Angelo, Ana Luiza D; Machado, Taisa M B; Lemaire, Denise C; Mendes, Carlos M C; Pinho, João R; Malta, Fernanda; Lyra, Luiz G C; Lyra, André C

    2012-03-01

    IL28B polymorphisms are predictors of therapy response in hepatitis C virus (HCV) patients. We do not know whether they are markers of treatment response in admixed populations or not. To determine whether IL28B polymorphisms are predictors of therapy response in patients with HCV from an admixed population and are influenced by genetic ancestry. rs12979860 and rs8099917 were genotyped in 222 HCV patients treated with pegylated interferon and ribavirin. Ancestry was determined using genetic markers. IL28B rs12979860 C/C was associated with sustained virological response (SVR), whereas C/T and T/T were associated with failure to therapy (P = 1.12 × 10(-5) ). IL28B rs8099917 T/T was associated with SVR, and G/G and G/T were associated with nonresponse/relapse (NR/R) (P = 8.00 × 10(-3) ). Among HCV genotype 1 patients with C/C genotype, genomic ancestry did not interfere with therapy response. Among patients with rs12979860 T/T genotype, African genetic contribution was greater in the NR/R group (P = 1.51 × 10(-3) ), whereas Amerindian and European genetic ancestry contribution were higher in the SVR group (P = 3.77 × 10(-3) and P = 2.16 × 10(-2) respectively). Among HCV type 1 patients with rs8099917 T/T, African genetic contribution was significantly greater in the NR/R group (P = 5.0 × 10(-3) ); Amerindian and European ancestry genetic contribution were greater in the SVR group. IL28B rs12979860 and rs8099917 polymorphisms were predictors of therapy response in HCV genotypes 1, 2 and 3 subjects from an admixed population. Genomic ancestry did not interfere with response to therapy in patients with rs12979860 C/C, whereas it interfered in patients with C/T and T/T genotypes. Among HCV genotype 1 rs8099917 T/T patients, genomic ancestry interfered with response to therapy. © 2011 John Wiley & Sons A/S.

  14. Recovery of native genetic background in admixed populations using haplotypes, phenotypes, and pedigree information--using Cika cattle as a case breed.

    Science.gov (United States)

    Simčič, Mojca; Smetko, Anamarija; Sölkner, Johann; Seichter, Doris; Gorjanc, Gregor; Kompan, Dragomir; Medugorac, Ivica

    2015-01-01

    The aim of this study was to obtain unbiased estimates of the diversity parameters, the population history, and the degree of admixture in Cika cattle which represents the local admixed breeds at risk of extinction undergoing challenging conservation programs. Genetic analyses were performed on the genome-wide Single Nucleotide Polymorphism (SNP) Illumina Bovine SNP50 array data of 76 Cika animals and 531 animals from 14 reference populations. To obtain unbiased estimates we used short haplotypes spanning four markers instead of single SNPs to avoid an ascertainment bias of the BovineSNP50 array. Genome-wide haplotypes combined with partial pedigree and type trait classification show the potential to improve identification of purebred animals with a low degree of admixture. Phylogenetic analyses demonstrated unique genetic identity of Cika animals. Genetic distance matrix presented by rooted Neighbour-Net suggested long and broad phylogenetic connection between Cika and Pinzgauer. Unsupervised clustering performed by the admixture analysis and two-dimensional presentation of the genetic distances between individuals also suggest Cika is a distinct breed despite being similar in appearance to Pinzgauer. Animals identified as the most purebred could be used as a nucleus for a recovery of the native genetic background in the current admixed population. The results show that local well-adapted strains, which have never been intensively managed and differentiated into specific breeds, exhibit large haplotype diversity. They suggest a conservation and recovery approach that does not rely exclusively on the search for the original native genetic background but rather on the identification and removal of common introgressed haplotypes would be more powerful. Successful implementation of such an approach should be based on combining phenotype, pedigree, and genome-wide haplotype data of the breed of interest and a spectrum of reference breeds which potentially have had

  15. Molecular analysis of the GYPB gene to infer S, s, and U phenotypes in an admixed population of Minas Gerais, Brazil

    Science.gov (United States)

    Faria, Marina Alves; Martins, Marina Lobato; Schmidt, Luciana Cayres; Malta, Maria Clara Fernandes da Silva

    2012-01-01

    Objective To implement genotyping for S, s and U antigens of the MNS blood group system at the Fundação Hemominas and to evaluate the occurrence of GYPB gene polymorphisms associated with the U- and U+var phenotypes and deletion of the GYPB gene for the first time in an admixed population of Minas Gerais, Brazil. The S, s and U antigens can cause transfusion reactions and perinatal hemolytic disease. Genotyping is a useful tool in immunohematology, especially when phenotyping cannot be performed. Methods Ninety-six samples from blood donors and patients with sickle cell disease previously phenotyped for the S, s and U antigens were selected. Allele-specific primer polymerase chain reaction (ASP-PCR) and polymerase chain reaction -restriction fragment length polymorphism (PCR-RFLP) assays were employed to identify the GYPB*S and GYPB*s alleles and the GYPB(P2) and GYPB(NY) variants, as well as deletion of the GYPB gene. Results The results of allele-specific genotyping (GYPB*S and GYPB*s) were totally in agreement with the phenotyping of S+ (n = 56), s+ (n = 60) and s- (n = 35) samples. However, the GYPB*S allele, in association with the GYPB(P2) variant, was detected in 17.5% of the S- samples (n = 40), which shows the importance of assessing this variant in the Brazilian population. Of the S-s- samples (n = 10), 60% had the deletion of the GYPB gene and 40% were homozygous or hemizygous for the GYPB(P2) variant. Conclusion Genotyping was an effective strategy to infer the S, s, and U phenotypes in the admixed population from Minas Gerais (Brazil) and may contribute to transfusion safety. PMID:23049422

  16. China Greatly Benefits from the West-East Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Statistics of the relevant department of China show that the West-East Gas Pipeline has boosted the rate of natural gas in China's primary energy mix from 2.2% to 3%, thus improving the safety of China's energy supply.

  17. Interactions between genetic admixture, ethnic identity, APOE genotype and dementia prevalence in an admixed Cuban sample; a cross-sectional population survey and nested case-control study

    Directory of Open Access Journals (Sweden)

    Hernandez Milagros

    2011-03-01

    Full Text Available Abstract Background The prevalence and incidence of dementia are low in Nigeria, but high among African-Americans. In these populations there is a high frequency of the risk-conferring APOE-e4 allele, but the risk ratio is less than in Europeans. In an admixed population of older Cubans we explored the effects of ethnic identity and genetic admixture on APOE genotype, its association with dementia, and dementia prevalence. Methods A cross-sectional catchment area survey of 2928 residents aged 65 and over, with a nested case-control study of individual admixture. Dementia diagnosis was established using 10/66 Dementia and DSM-IV criteria. APOE genotype was determined in 2520 participants, and genetic admixture in 235 dementia cases and 349 controls. Results Mean African admixture proportions were 5.8% for 'white', 28.6% for 'mixed' and 49.6% for 'black' ethnic identities. All three groups were substantially admixed with considerable overlap. African admixture was linearly related to number of APOE-e4 alleles. One or more APOE-e4 alleles was associated with dementia in 'white' and 'black' but not 'mixed' groups but neither this, nor the interaction between APOE-e4 and African admixture (PR 0.52, 95% CI 0.13-2.08 were statistically significant. Neither ethnic identity nor African admixture was associated with dementia prevalence when assessed separately. However, considering their joint effects African versus European admixture was independently associated with a higher prevalence, and 'mixed' or 'black' identity with a lower prevalence of dementia. Conclusions APOE genotype is strongly associated with ancestry. Larger studies are needed to confirm whether the concentration of the high-risk allele in those with African ancestry is offset by an attenuation of its effect. Counter to our hypothesis, African admixture may be associated with higher risk of dementia. Although strongly correlated, effects of admixture and ethnic identity should be

  18. Interethnic variability of CYP4F2 (V433M) in admixed population of Roma and Hungarians.

    Science.gov (United States)

    Sipeky, Csilla; Weber, Agnes; Melegh, Bela I; Matyas, Petra; Janicsek, Ingrid; Szalai, Renata; Szabo, Istvan; Varnai, Reka; Tarlos, Greta; Ganczer, Alma; Melegh, Bela

    2015-07-01

    Pharmacogenetic based dosing recommendations are provided in FDA-approved warfarin label for Caucasians. Evidence of notable difference in dosing algorithms of under-represented populations forced us to explore the genetic variability of CYP4F2 gene in Roma and Hungarian populations. 484 Roma, 493 Hungarian untreated subjects were genotyped for the CYP4F2*3 (rs2108622) variant by PCR-RFLP assay. We firstly report, that frequencies of the CYP4F2 rs2108622 GG, GA, AA genotypes and A allele in the Roma population were 46.5%, 42.6%, 10.9% and 32.2%; in Hungarians 50.1%, 42.2%, 7.7% and 22.8%, respectively. Bearing of two minor alleles of CYP4F2 missense variant (AA genotype) modestly explains inter-ethnic differences of studied populations (pRoma (0.32) was in higher range, and of Hungarians (0.23) in lower range, as compared with other world populations. Roma have an elevated chance for higher mean warfarin dose, besides a decreased risk of major bleeding events in long-term warfarin use. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Allelic frequencies and statistical data obtained from 12 codis STR loci in an admixed population of the Brazilian Amazon

    Science.gov (United States)

    da Costa Francez, Pablo Abdon; Rodrigues, Elzemar Martins Ribeiro; Frazão, Gleycianne Furtado; dos Reis Borges, Nathalia Danielly; dos Santos, Sidney Emanuel Batista

    2011-01-01

    The allelic frequencies of 12 short tandem repeat loci were obtained from a sample of 307 unrelated individuals living in Macapá, a city in the northern Amazon region, Brazil. These loci are the most commonly used in forensics and paternity testing. Based on the allele frequency obtained for the population of Macapá, we estimated an interethnic admixture for the three parental groups (European, Native American and African) of, respectively, 46%, 35% and 19%. Comparing these allele frequencies with those of other Brazilian populations and of the Iberian Peninsula population, no significant distances were observed. The interpopulation genetic distances (FST coefficients) to the present database ranged from FST = 0.0016 between Macapá and Belém to FST = 0.0036 between Macapá and the Iberian Peninsula. PMID:21637540

  20. Allelic frequencies and statistical data obtained from 12 codis STR loci in an admixed population of the Brazilian Amazon

    Directory of Open Access Journals (Sweden)

    Pablo Abdon da Costa Francez

    2011-01-01

    Full Text Available The allelic frequencies of 12 short tandem repeat loci were obtained from a sample of 307 unrelated individuals living in Macapá, a city in the northern Amazon region, Brazil. These loci are the most commonly used in forensics and paternity testing. Based on the allele frequency obtained for the population of Macapá, we estimated an interethnic admixture for the three parental groups (European, Native American and African of, respectively, 46%, 35% and 19%. Comparing these allele frequencies with those of other Brazilian populations and of the Iberian Peninsula population, no significant distances were observed. The interpopulation genetic distances (F ST coefficients to the present database ranged from F ST = 0.0016 between Macapá and Belém to F ST = 0.0036 between Macapá and the Iberian Peninsula.

  1. Allelic frequencies and statistical data obtained from 12 codis STR loci in an admixed population of the Brazilian Amazon.

    Science.gov (United States)

    da Costa Francez, Pablo Abdon; Rodrigues, Elzemar Martins Ribeiro; Frazão, Gleycianne Furtado; Dos Reis Borges, Nathalia Danielly; Dos Santos, Sidney Emanuel Batista

    2011-01-01

    The allelic frequencies of 12 short tandem repeat loci were obtained from a sample of 307 unrelated individuals living in Macapá, a city in the northern Amazon region, Brazil. These loci are the most commonly used in forensics and paternity testing. Based on the allele frequency obtained for the population of Macapá, we estimated an interethnic admixture for the three parental groups (European, Native American and African) of, respectively, 46%, 35% and 19%. Comparing these allele frequencies with those of other Brazilian populations and of the Iberian Peninsula population, no significant distances were observed. The interpopulation genetic distances (F(ST) coefficients) to the present database ranged from F(ST) = 0.0016 between Macapá and Belém to F(ST) = 0.0036 between Macapá and the Iberian Peninsula.

  2. Association of serum lipid components and obesity with genetic ancestry in an admixed population of elderly women

    Science.gov (United States)

    Lins, Tulio C.; Pires, Alause S.; Paula, Roberta S.; Moraes, Clayton F.; Vieira, Rodrigo G.; Vianna, Lucy G.; Nobrega, Otávio T.; Pereira, Rinaldo W.

    2012-01-01

    The prevalence of metabolic disorders varies among ethnic populations and these disorders represent a critical health care issue for elderly women. This study investigated the correlation between genetic ancestry and body composition, metabolic traits and clinical status in a sample of elderly women. Clinical, nutritional and anthropometric data were collected from 176 volunteers. Genetic ancestry was estimated using 23 ancestry-informative markers. Pearsons correlation test was used to examine the relationship between continuous variables and an independent samples t-test was used to compare the means of continuous traits within categorical variables. Overall ancestry was a combination of European (57.49%), Native American (25.78%) and African (16.73%). Significant correlations were found for European ancestry with body mass index (r = 0.165; p = 0.037) and obesity (mean difference (MD) = 5.3%; p = 0.042). African ancestry showed a significant correlation with LDL (r = 0.159, p = 0.035), VLDL (r = −0.185; p = 0.014), hypertriglyceridemia (MD = 6.4%; p = 0.003) and hyperlipidemia (MD = 4.8%; p = 0.026). Amerindian ancestry showed a significant correlation with triglyceride levels (r = 0.150; p = 0.047) and hypertriglyceridemia (MD = 4.5%; p = 0.039). These findings suggest that genetic admixture may influence the etiology of lipid metabolism-related diseases and obesity in elderly women. PMID:23055794

  3. High frequency of the CCR5delta32 variant among individuals from an admixed Brazilian population with sickle cell anemia

    Directory of Open Access Journals (Sweden)

    J.A.B. Chies

    2003-01-01

    Full Text Available Homozygous sickle cell disease (SCD has a wide spectrum of clinical manifestations. In Brazil, the main cause of death of individuals with SCD is recurrent infection. The CCR5delta32 allele, which confers relative resistance to macrophage-tropic HIV virus infection, probably has reached its frequency and world distribution due to other pathogens that target macrophage in European populations. In the present investigation a relatively higher prevalence (5.1% of the CCR5delta32 allele was identified, by PCR amplification using specific primers, in 79 SCD patients when compared to healthy controls (1.3% with the same ethnic background (Afro-Brazilians. Based on a hypothesis that considers SCD as a chronic inflammatory condition, and since the CCR5 chemokine receptor is involved in directing a Th1-type immune response, we suggest that a Th1/Th2 balance can influence the morbidity of SCD. If the presence of the null CCR5delta32 allele results in a reduction of the chronic inflammation state present in SCD patients, this could lead to differential survival of SCD individuals who are carriers of the CCR5delta32 allele. This differential survival could be due to the development of less severe infections and consequently reduced or less severe vaso-occlusive crises.

  4. Genetic variants in interleukin genes are associated with breast cancer risk and survival in a genetically admixed population: the Breast Cancer Health Disparities Study.

    Science.gov (United States)

    Slattery, Martha L; Herrick, Jennifer S; Torres-Mejia, Gabriella; John, Esther M; Giuliano, Anna R; Hines, Lisa M; Stern, Mariana C; Baumgartner, Kathy B; Presson, Angela P; Wolff, Roger K

    2014-08-01

    Interleukins (ILs) are key regulators of immune response. Genetic variation in IL genes may influence breast cancer risk and mortality given their role in cell growth, angiogenesis and regulation of inflammatory process. We examined 16 IL genes with breast cancer risk and mortality in an admixed population of Hispanic/Native American (NA) (2111 cases and 2597 controls) and non-Hispanic white (NHW) (1481 cases and 1585 controls) women. Adaptive Rank Truncated Product (ARTP) analysis was conducted to determine gene significance and lasso (least absolute shrinkage and selection operator) was used to identify potential gene by gene and gene by lifestyle interactions. The pathway was statistically significant for breast cancer risk overall (P ARTP = 0.0006), for women with low NA ancestry (P(ARTP) = 0.01), for premenopausal women (P(ARTP) = 0.02), for estrogen receptor (ER)+/progesterone receptor (PR)+ tumors (P(ARTP) = 0.03) and ER-/PR- tumors (P(ARTP) = 0.02). Eight of the 16 genes evaluated were associated with breast cancer risk (IL1A, IL1B, IL1RN, IL2, IL2RA, IL4, IL6 and IL10); four genes were associated with breast cancer risk among women with low NA ancestry (IL1B, IL6, IL6R and IL10), two were associated with breast cancer risk among women with high NA ancestry (IL2 and IL2RA) and four genes were associated with premenopausal breast cancer risk (IL1A, IL1B, IL2 and IL3). IL4, IL6R, IL8 and IL17A were associated with breast cancer-specific mortality. We confirmed associations with several functional polymorphisms previously associated with breast cancer risk and provide support that their combined effect influences the carcinogenic process.

  5. Mapping SLCO1B1 Genetic Variation for Global Precision Medicine in Understudied Regions in Africa: A Focus on Zulu and Cape Admixed Populations.

    Science.gov (United States)

    Hoosain, Nisreen; Pearce, Brendon; Jacobs, Clifford; Benjeddou, Mongi

    2016-09-01

    The U.S. President Barack Obama has announced, in his State of the Union address on January 20, 2015, the Precision Medicine Initiative, a US$215-million program. For global precision medicine to become a reality, however, biological and environmental "variome" in previously understudied populations ought to be mapped and catalogued. Chief among the molecular targets that warrant global mapping is the organic anion-transporting polypeptide 1B1 (OATP1B1), encoded by solute carrier organic anion transporter family member 1B1 (SLCO1B1), a hepatic uptake transporter predominantly expressed in the basolateral side of hepatocytes. Human OATP1B1 plays a crucial role in the transport of a wide variety of substrates. This includes endogenous compounds such as bile salts as well as medicines, including benzylpenicillin, methotrexate, pravastatin, and rifampicin, and natural toxins microcystin and phalloidin. Genetic variations observed in the SLCO1B1 gene have been associated with altered in vitro and in vivo OATP1B1 transport activity, and consequently influencing patients' response to medicines, toxins, and susceptibility to common complex diseases. Well-characterized haplotypes, *5 (RS4149056C) and *15 (RS4149056T), have been associated with a strikingly reduced uptake of multiple OATP1B1 substrates, including estrone-3-sulfate, estradiol-17β-d-glucuronide, atorvastatin, cerivastatin, pravastatin, and rifampicin. In particular, RS4149056C is observed in 60% of the Cape admixed (CA) population and is associated with increased plasma concentrations of many statins as well as fexofenadine and repaglinide. We designed and optimized a SNaPshot minisequencing panel to characterize the variants of relevance for precision medicine in the clinic. We report here the first study on allele and genotype frequencies for 10 nonsynonymous, 4 synonymous, and 6 intronic single-nucleotide polymorphisms of SLCO1B1 in the Zulu and CA populations of South Africa. These variants are further

  6. Welding technique studies on the "West-East" pipeline project

    Institute of Scientific and Technical Information of China (English)

    Sui Yongli; Du Zeyu; Huang Fuxiang; Qi Lichun

    2006-01-01

    This paper described the work of welding process design for the "West-East" pipeline project, which is high pressure, large diameter and heavy wall thickness. According to the different geographical situation, climate, culture and the flexibility of the welding methods, this work recommended the semi-automatic process at the east and middle sections and automatic process at the west section of the pipeline project. The manual process is recommended on the tie-in joints and repairs. The double joint pipe and the 3 joint pipe are recommended at the water net place and some in-ditch welding place to reduce the welding volume. Also the special redesigned bevels are recommended for the automatic process and the semiautomatic process. Through all destructive tests, the results shows the welds are meet the requirements of related standards,specifications and design documents.

  7. Social and Economic Benefits of the West-East Gas Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    Li Xiangyang

    2002-01-01

    @@ On July 4 2002, a project attracting world attention, i.e., the West-East Gas Pipeline Project was declared in full-scale commencement. The project will write history with its enormous social and economic benefits.

  8. The population demography of Betula maximowicziana, a cool-temperate tree species in Japan, in relation to the last glacial period: its admixture-like genetic structure is the result of simple population splitting not admixing.

    Science.gov (United States)

    Tsuda, Y; Nakao, K; Ide, Y; Tsumura, Y

    2015-04-01

    Conservation of the local genetic variation and evolutionary integrity of economically and ecologically important trees is a key aspect of studies involving forest genetics, and a population demographic history of the target species provides valuable information for this purpose. Here, the genetic structure of 48 populations of Betula maximowicziana was assessed using 12 expressed sequence tag-simple sequence repeat (EST-SSR) markers. Genetic diversity was lower in northern populations than southern ones and structure analysis revealed three groups: northern and southern clusters and an admixed group. Eleven more genomic-SSR loci were added and the demographic history of these three groups was inferred by approximate Bayesian computation (ABC). The ABC revealed that a simple split scenario was much more likely than isolation with admixture, suggesting that the admixture-like structure detected in this species was due to ancestral polymorphisms. The ABC analysis suggested that the population growth and divergence of the three groups occurred 96 800 (95% CI, 20 500-599 000) and 28 300 (95% CI, 8700-98 400) years ago, respectively. We need to be aware of several sources of uncertainty in the inference such as assumptions about the generation time, overlapping of generations, confidence intervals of the estimated parameters and the assumed model in the ABC. However, the results of the ABC together with the model-based maps of reconstructed past species distribution and palaeoecological data suggested that the modern genetic structure of B. maximowicziana originated prior to the last glacial maximum (LGM) and that some populations survived in the northern range even during the LGM. © 2015 John Wiley & Sons Ltd.

  9. PRI Play Important Role in West-East Project · Interview with PIR Director Xue Zhenkui

    Institute of Scientific and Technical Information of China (English)

    Xiao Lu

    2002-01-01

    @@ Pipeline Research Institute of CNPC (PRI) is playing a more and more important role in the oil and natural gas pipeline industrial development in the present-day China. The pipeline technology and equipment developed by PRI have proven costeffective and extremely useful in the country's WestEast gas transmission pipeline project

  10. Research & Development of Grade X70 LSAW Steel Pipes for West-East Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    WangXiaoxiang; SunQi

    2004-01-01

    In this article the research and development of X70 large diameter longitudinal seam submerged arc welded (LSAW) steel pipes for West-East Gas Transportation Pipeline project (WEGTP) in China are introduced, including the key technique, fabrication of pipe production line, mass production and the latest progress of LSAW steel pipe technique.

  11. The Technical Specification and Physical Performance Level of Line Pipes for West-East Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    FengBin; WangMaotang; LiuFangming; XiaoLiming

    2004-01-01

    The west-east gas transmission engineering is an important project attracting domestic and foreign attention. The gas pipeline used in this project is a gas pipeline with the longest distance, largest pipe diameter and highest transmission pressure in the history of petroleum pipeline construction of China. For the construction of top-rank gas pipeline in the world with high standard, high speed and high benefit, the key of specifying production of metallurgical and pipe-making enterprises and ensuring quality performance of the steel and steel pipe is to research and formulate a feasible and satisfactory technical Specification for engineering steel and steel pipe with international level. In this paper the author introduces the establishment of the technical specification for West-East gas pipeline project, and lays emphasis on the analysis and discussion of principle and method determining major technical indexes related to line pipes for West-East gas pipeline. The author also introduces actual material selection of gas pipeline home and abroad, and presents examination and application of the technical specification for West-East gas pipeline.

  12. The Studies of the Welding Processes and Procedures on the West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    SuiYongli; HuangFuxiang; ZhaoHaihong; YinChanghua

    2004-01-01

    The West-East pipeline project attracted the attention from all over the world for its long distance, huge diameter, complex geographic conditions, and diversified welding techniques being applied. In this paper the detail welding process and procedures used in the project are discussed and the distinguished achievements on welding techniques of China pipeline construction are described.

  13. SAFE AND EFFICIENT OPERATION OF THE WEST-EAST GAS PIPELINE FOR FIVE YEARS

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ The West-East gas pipeline in China has been operated for five years since the commencement of operation on Oct.1st,2003,Over the past five years the pipeline has maintained its safe,stable and high efficint status and brought favorable economic ,social and environmental effects.

  14. Invasive cyprinid fish in Europe originate from the single introduction of an admixed source population followed by a complex pattern of spread.

    Directory of Open Access Journals (Sweden)

    Andrea Simon

    Full Text Available The Asian cyprinid fish, the topmouth gudgeon (Pseudorasbora parva, was introduced into Europe in the 1960s. A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range. Here we analyse a 700 base pair fragment of the mitochondrial cytochrome b gene to examine different models of colonisation and spread within the invasive range, and to investigate the factors that may have contributed to their invasion success. Haplotype and nucleotide diversity of the introduced populations from continental Europe was higher than that of the native populations, although two recently introduced populations from the British Isles showed low levels of variability. Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity. This suggests that these populations are not in mutation-drift equilibrium, but rather that the relative inflated level of nucleotide diversity is consistent with recent admixture. This study elucidates the colonisation patterns of P. parva in Europe and provides an evolutionary framework of their invasion. It supports the hypothesis that their European colonisation was initiated by their introduction to a single location or small geographic area with subsequent complex pattern of spread including both long distance and stepping-stone dispersal. Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

  15. Invasive cyprinid fish in Europe originate from the single introduction of an admixed source population followed by a complex pattern of spread.

    Science.gov (United States)

    Simon, Andrea; Britton, Robert; Gozlan, Rodolphe; van Oosterhout, Cock; Volckaert, Filip A M; Hänfling, Bernd

    2011-01-01

    The Asian cyprinid fish, the topmouth gudgeon (Pseudorasbora parva), was introduced into Europe in the 1960s. A highly invasive freshwater fish, it is currently found in at least 32 countries outside its native range. Here we analyse a 700 base pair fragment of the mitochondrial cytochrome b gene to examine different models of colonisation and spread within the invasive range, and to investigate the factors that may have contributed to their invasion success. Haplotype and nucleotide diversity of the introduced populations from continental Europe was higher than that of the native populations, although two recently introduced populations from the British Isles showed low levels of variability. Based on coalescent theory, all introduced and some native populations showed a relative excess of nucleotide diversity compared to haplotype diversity. This suggests that these populations are not in mutation-drift equilibrium, but rather that the relative inflated level of nucleotide diversity is consistent with recent admixture. This study elucidates the colonisation patterns of P. parva in Europe and provides an evolutionary framework of their invasion. It supports the hypothesis that their European colonisation was initiated by their introduction to a single location or small geographic area with subsequent complex pattern of spread including both long distance and stepping-stone dispersal. Furthermore, it was preceded by, or associated with, the admixture of genetically diverse source populations that may have augmented its invasive-potential.

  16. Analysis of genetic ancestry in the admixed Brazilian population from Rio de Janeiro using 46 autosomal ancestry-informative indel markers.

    Science.gov (United States)

    Manta, Fernanda Saloum Neves; Pereira, Rui; Caiafa, Alexandre; Silva, Dayse Aparecida; Gusmão, Leonor; Carvalho, Elizeu Fagundes

    2013-01-01

    The Brazilian population is highly heterogeneous as a result of five centuries of inter-ethnic mating between native Amerindians, European colonizers and Africans arrived during slavery. This study aimed to assess the proportions of inter-ethnic admixture in the Brazilian population of Rio de Janeiro using autosomal Ancestry-Informative Markers (AIMs). The autosomal data were also compared to the results expected from uniparental genetic markers. A total of 413 individuals were genotyped for 46 AIM-Indels and ancestry estimates were then assessed using HGDP-CEPH samples as ancestral reference. Individuals from Rio de Janeiro presented highly diverse admixture patterns. The global admixture estimates showed a predominantly European ancestry, above 55%, followed by African and Amerindian contributions. A separate self-declared Afro-descendant group also included in this study revealed an increased African ancestry, from ∼30% to ∼50%. The inter-ethnic admixture landscape of Rio de Janeiro captured by autosomal AIM-Indels is in agreement with historical records and similar to that expected from uniparental mtDNA and Y-chromosome information. The AIM-Indel panel proved to be a rapid strategy to estimate autosomal genetic ancestry at individual and population levels in Rio de Janeiro, which is useful in population genetics and in case-control association studies.

  17. Manufacturing Technology Research and Appraisal of Large-Diameter SSAW Pipe Applied to the West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    DingXiaojun; YangZhongwen; XiaXianhua; LiXiaobo

    2005-01-01

    This paper introduced the research and development of large-diameter SSAW pipes applied to West-East Pipeline project as well as domestic acicular ferrite pipeline steel of X70 grade. Its microstructure analysis was performed in comparison with the pipeline steel of a foreign steel plant (SPC). This paper introduced the research of welding procedures prior to SSAW pipe making and some new procedures and technologies used for West-East Pipeline Project, and appraised the practical level of Large-diameter SSAW pipe applied to the West-East Pipeline Project.

  18. West-East Gas Project Locates Two Large Consumers in East China

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    @@ The gigantic west-east gas pipeline is well on the way to begin delivering gas by October, despite a delay to the project's joint venture with foreign partners including ExxonMobil and Royal/Dutch Shell. PetroChina, the major Chinese backer of the project, is also expected to sign the long-awaited gas supply contracts in the next few weeks with two gas buyers, including a large petrochemical venture of German firm BASF.

  19. Application of New Techniques, Materials and Technologies in West-East Gas Transportation Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    DongXu

    2004-01-01

    With the application of new techniques, materials and technologies in West-East Gas Transportation Pipeline (WEGTP) project, the design concept of domestic pipeline industrial construction has been updated, speeding up the development and improvement of the strength as a whole in aspects of smelting industry, pipe fabrication, pipeline construction and equipment manufacture, making China's pipeline industry catch up with the trend of development of the world advanced level.

  20. Cultural junctions West-East: Nikos Kazantzakis and Nagai Kafū

    Directory of Open Access Journals (Sweden)

    Rodica FRENŢIU

    2013-01-01

    Full Text Available The present study, titled Cultural junctions West-East: Nikos Kazantzakis and Nagai Kafū, tries to approach two writers who, despite coming from cultural spaces set at great geographical distance, could be compared in terms of both biographical details and the aesthetic program of their works. We therefore read from a hermeneutical perspective Nikos Kazantzakis’ Report to Greco and Nagai Kafū’s last novel, A Strange Tale from East of the River, proposing a new code of reading, close to the labyrinth of the creative act and to the mystery of creation by which the two given texts could be joined.

  1. Capabilities of nitrogen admixed cryogenic deuterium pellets

    Energy Technology Data Exchange (ETDEWEB)

    Sharov, Igor; Sergeev, Vladimir [SPU, Saint-Petersburg (Russian Federation); Lang, Peter; Ploeckl, Bernhard; Cavedon, Marco [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany); Kocsis, Gabor; Szepesi, Tamas [Wigner RCP RMI, Budapest (Hungary); Collaboration: ASDEX Upgrade Team

    2015-05-01

    Operation at high core density with high energy confinement - as foreseen in a future fusion reactor like DEMO - is being investigated at ASDEX Upgrade tokamak. The efficiency of pellet fuelling from the high-field side usually increases with increasing injection speed. Due to the fragile nature of the deuterium ice, however, the increment of pellet mass losses and subsequent pellet fragmentations take place when the speed is increased. Studies show, that admixing of a small amount of nitrogen (N{sub 2}) into D{sub 2} gas can be favorable for the mechanical stability of pellets. This might be helpful for deeper pellet penetration. Besides, seeding by N{sub 2} can enhance plasma performance due to both increasing the energy confinement time and reducing the divertor heat load in the envisaged ELMy H-mode plasma scenario. Fuelling efficiency of N{sub 2}-admixed solid D{sub 2} pellets and their nitrogen seeding capabilities were investigated. It was found that both the overall plasma density increase and the measured averaged pellet penetration depth were smaller in case of the admixed (1% mol. in the gas resulting in about 0.8% in the ice) pellet fuelling. Possibility of the N{sub 2}-seeding by admixed pellets was confirmed by CXRS measurements of N{sup 7+} content in plasma.

  2. Foreign Cooperation Plays Important Role in West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ West-to-East gas pipeline project is the largest project undertaken by PetroChina since the company issued IPO at international capital markets in 1999.Construction of West-East gas pipeline is of great strategic significance to secure PetroChina's leading position in the domestic natural gas market, turn the company's advantage in resources into benefits and make the natural gas business a new growth point for the company. Meanwhile, the project will benefit the economic development in China's western region,Xinjiang area in particular, improve the energy structure in the natural gas consuming regions and atmospheric environment in the areas along the pipeline and raise the general living standards.

  3. TNF promoter SNP variation in Amerindians and white-admixed women from Misiones, Argentina.

    Science.gov (United States)

    Badano, I; Schurr, T G; Stietz, S M; Dulik, M C; Mampaey, M; Quintero, I M; Zinovich, J B; Campos, R H; Liotta, D J

    2013-06-01

    The aim of this study is to describe genetic variation in the TNF promoter in the ethnically diverse population of Misiones, north-eastern Argentina. We analysed 210 women including 66 Amerindians of the Mbya-Guarani ethnic group and 144 white-admixed individuals from urban and rural areas of Misiones. Their DNA samples were surveyed for TNF polymorphisms -376 A/G, -308 A/G -244 A/G and -238 A/G by PCR amplification and direct sequencing and for the Amerindian marker -857 C/T by real-time PCR. Our main findings are as follows:(i) a distinctive pattern of Single Nucleotide Polymorphism (SNP) distribution among these groups, (ii) genetic differentiation between the Mbya-Guarani and the white-admixed populations (P Misiones.

  4. Effect of Penetron Admix on the Properties of Concrete

    African Journals Online (AJOL)

    2012r

    2014-07-02

    Jul 2, 2014 ... whether the product is suitable for use on construction projects in Mauritius. A ... which is the most important concrete property, was found to ... A new type of waterproofing admixture namely, PENETRON ADMIX, has been.

  5. A Crossroad Between West, East and Orient – The Case of Albanian Culture

    Directory of Open Access Journals (Sweden)

    Irena Sawicka

    2015-06-01

    Full Text Available A Crossroad Between West, East and Orient – The Case of Albanian Culture Albania is a unique example of authentic mentally-coded multiculturalism. The influence of a certain type of culture on believes shared by all Albanians is connected with either a specific period in history or specific territory. Modern Albania inherits various influences. As a unique European society Albanians do not define their identity through affiliation to a specific cultural (religious circle. Nowadays Albanian national identity is devoid of religious context. It is based on the idea of Illyrian origin, great figures of Albanian history, mythology, language separateness. Religious components make up a surface of purely ethnographic character. Albanians attach greater importance to traditional values connected with the medieval clan law (besa ‘a word, a promise of keeping the word, commitment’, honor, the cult of a visitor, clan vengeance, the institution of a sworn virgin and so on.   Kultura albańska – zderzenie Zachodu, Wschodu i Orientu Albania jest unikalnym przykładem prawdziwej, zakodowanej mentalnie multikulturowości. Wpływ określonego typu kultury na poglądy wspólne wszystkim Albańczykom związany jest bądź z określonym okresem historycznym, bądź z określonym terytorium. Dzisiejsza Albania dziedziczy różne wpływy i, jako unikalne w Europie społeczeństwo, Albańczycy nie określają swojej tożsamości poprzez przynależność do określonego kręgu kulturowego (religijnego. Współcześnie tożsamość narodowa Albańczyków zbudowana jest więc bez kontekstu religijnego. Opiera się na koncepcji pochodzenia od Ilirów, wielkich postaciach historii albańskiej, mitologii, odrębności językowej. Elementy religijne stanowią warstwę powierzchowną, czysto etnograficzną. Większą wagę przywiązują Albańczycy do wartości tradycyjnych, związanych ze średniowiecznym prawem rodowym (besa ‘słowo, obietnica, zobowi

  6. Research and Development of X70 with an Acicular Ferrite Microstructure for West-East Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    ZhengLei; GaoShan

    2004-01-01

    It is introduced in this paper that a high strength and high toughness X70 pipeline steel with an ultra-low acicular ferrite microstructure has been researched and developed at Baosteel according to the requirements of the West-East Gas Pipeline(WEGTP) project. The developed steel has higher strength, higher toughness, lower ductile-brittle transition temperature and higher dynamic tear-resistance than the conventional X70 with ferrite and pearlite microstructure. The excellent properties of the steel are benefited from ultralow carbon acicular ferrite consisting of interaction of very fine precipitated particles and high-density dislocation. And the steel has been applied on the WEGTP in China.

  7. West-east contrast of phenology and climate in northern Asia revealed using a remotely sensed vegetation index.

    Science.gov (United States)

    Suzuki, Rikie; Nomaki, Tomoyuki; Yasunari, Tetsuzo

    2003-05-01

    The phenology of the vegetation covering north Asia (mainly Siberia) and its spatial characterstics were investigated using remotely sensed normalized difference vegetation index (NDVI) data. The analysis used the weekly averaged NDVI over 5 years (1987-1991) using the second-generation weekly global vegetation index dataset (0.144 degrees x 0.144 degrees spatial resolution). In the seasonal NDVI cycle, three phenological events were defined for each pixel: green-up week (NDVI exceeds 0.2), maximum week, and senescence week (NDVI drops below 0.2). Generally there was a west-early/east-late gradient in the three events in north Asia. In the zonal transect between 45 degrees and 50 degrees N, the timing of green-up, maximum, and senescence near 60 degrees E (Kazakh) was about 3.4, 8.7, and 13.4 weeks earlier than near 110 degrees E (Mongolia) respectively. It has been suggested that vegetation near Kazakh only flourishes during a short period when water from snow melt is available from late spring to early summer. In Mongolia, abundant water is available for the vegetation, even in midsummer, because of precipitation. In the 50-60 degrees N zonal transect, the green-up and maximum near 40 degrees E were about 3.8 and 3.9 weeks earlier than near 115 degrees E, respectively. As for the week of senescence, there was no clear west-east trend. This west-to-east phenological gradient was related to the weekly cumulative temperature (over 0 degrees C). Weeks in which the cumalative temperature exceeded 40 degrees C and 140 degrees C had a similar west-east distribution to green-up and maximum NDVI.

  8. Possible triggering of solar activity to big earthquakes (Ms ≥ 8) in faults with near west-east strike in China

    Institute of Scientific and Technical Information of China (English)

    HAN; Yanben; GUO; Zengjian; WU; Jinbing; MA; Lihua

    2004-01-01

    This paper studies the relationship between solar activity and big earthquakes (Ms≥8) that occurred in China and western Mongolia. It is discovered that the occurrence dates of most of the big earthquakes in and near faults with west-east strike are close to the maximum years of sunspot numbers, whereas dates of some big earthquakes which are not in such faults are not close to the maximum years. We consider that it is possibly because of the appearance of many magnetic storms in the maximum years of solar activity. The magnetic storms result in anomalies of geomagnetic field and then produce eddy current in the faults gestating earthquake with near west-east strike. Perhaps the gestated big earthquakes occur easily since the eddy current heats the rocks in the faults and therefore decreases the shear resistant intensity and the static friction limit of the rocks.

  9. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    Tuan; Anh; Nguyen; Recep; AVCI

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride and the admixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the polarization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  10. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    SHI XianMing; YANG ZhengXian; Tuan Anh Nguyen; SUO ZhiYong; Recep AVCI; SONG ShiZhe

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCI and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mor-tar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hy-drates at the steel-mortar interracial region, but partially displaced chloride ions. Chloride and the ad-mixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the po-larization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  11. Colombia's racial crucible: Y chromosome evidence from six admixed communities in the Department of Bolivar.

    Science.gov (United States)

    Noguera, María Claudia; Schwegler, Armin; Gomes, Verónica; Briceño, Ignacio; Alvarez, Luis; Uricoechea, Daniel; Amorim, António; Benavides, Escilda; Silvera, Carlos; Charris, Marlon; Bernal, Jaime E; Gusmão, Leonor

    2014-01-01

    To determine the African, European and Native-American paternal contributions in genetic samples from the Department of Bolivar (Colombia) with the aims of establishing (1) possible population substructures, and (2) the proportion of biological African heritage in admixed populations of European, Amerindian, and African descent. Y-SNPs were typed in samples from six communities, including Palenque (renowned for its African linguistic and cultural heritage). Findings reveal a high diversity of Y-haplogroups. With the exception of Palenque, the sum of European male lineages uniformly exceeded 57%. In Palenque, African lineages accounted for 57.7% of its chromosomes, with European male lineages constituting a mere 38.5%. In Pinillos, a significant proportion (23.8%) of the chromosomes belongs to the Native American haplogroup Q1a3a*-M3. Genetic differentiation analyses reveal significant divergences in most pairwise comparisons among the Bolivar municipalities, and the same holds between Bolivar and other South American populations. Heterogeneous patterns of admixture reveal a genetic substructure within the Department of Bolivar. On the paternal side, five out of the six communities studied exhibit a predominantly European gene pool. The exception is Palenque, where European input (38%) is more significant than we had expected.

  12. A Rotation of Admixable Operators on Abstract Wiener Space with Applications

    Directory of Open Access Journals (Sweden)

    Jae Gil Choi

    2013-01-01

    Full Text Available We investigate certain rotation properties of the abstract Wiener measure. To determine our rotation property for the Wiener measure, we introduce the concept of an admixable operator via an algebraic structure on abstract Wiener space. As for applications, we define the analytic Fourier-Feynman transform and the convolution product associated with the admixable operators and proceed to establish the relationships between this transform and the corresponding convolution product.

  13. Recent and historical recombination in the admixed Norwegian Red cattle breed

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    Grove Harald

    2011-01-01

    Full Text Available Abstract Background Comparison of recent patterns of recombination derived from linkage maps to historical patterns of recombination from linkage disequilibrium (LD could help identify genomic regions affected by strong artificial selection, appearing as reduced recent recombination. Norwegian Red cattle (NRF make an interesting case study for investigating these patterns as it is an admixed breed with an extensively recorded pedigree. NRF have been under strong artificial selection for traits such as milk and meat production, fertility and health. While measures of LD is also crucial for determining the number of markers required for association mapping studies, estimates of recombination rate can be used to assess quality of genomic assemblies. Results A dataset containing more than 17,000 genome-wide distributed SNPs and 2600 animals was used to assess recombination rates and LD in NRF. Although low LD measured by r2 was observed in NRF relative to some of the breeds from which this breed originates, reports from breeds other than those assessed in this study have described more rapid decline in r2 at short distances than what was found in NRF. Rate of decline in r2 for NRF suggested that to obtain an expected r2 between markers and a causal polymorphism of at least 0.5 for genome-wide association studies, approximately one SNP every 15 kb or a total of 200,000 SNPs would be required. For well known quantitative trait loci (QTLs for milk production traits on Bos Taurus chromosomes 1, 6 and 20, map length based on historic recombination was greater than map length based on recent recombination in NRF. Further, positions for 130 previously unpositioned contigs from assembly of the bovine genome sequence (Btau_4.0 found using comparative sequence analysis were validated by linkage analysis, and 28% of these positions corresponded to extreme values of population recombination rate. Conclusion While LD is reduced in NRF compared to some of the

  14. Study and Application of Internal Coating Technique to Drag Reduction of the Trunk Pipeline for the West-East Gas Pipeline

    Institute of Scientific and Technical Information of China (English)

    HuShixin; QuShenyang; LinZhu

    2004-01-01

    Coverage layer coated in the internal wall of pipeline enables the friction drag to be reduced, the throughput and the gas transmission efficiency to be increased, the frequency of pigging and the number of the intermediate compressor station to be reduced, and the power consumption of the compressor to be decreased etc. The drag reduction is a high advanced scientific technique with outstanding economical benefit. The study and application of internal coating technique for drag reduction of 4000km trunk pipeline in West-East gas transmission pipeline (WEGTP) project are described, in which the main points are the drag reduction principle, coating process and the indoor study of this technique with own-decided knowledge property right at home.

  15. Genomic adaptation of admixed dairy cattle in East Africa

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    Eui-Soo eKim

    2014-12-01

    Full Text Available Dairy cattle in East Africa imported from the U.S. and Europe have been adapted to new environments. In small local farms, cattle have generally been maintained by crossbreeding that could increase survivability under a severe environment. Eventually, genomic ancestry of a specific breed will be nearly fixed in genomic regions of local breeds or crossbreds when it is advantageous for survival or production in harsh environments. To examine this situation, 25 Friesians and 162 local cattle produced by crossbreeding of dairy breeds in Kenya were sampled and genotyped using 50K SNPs. Using principal component analysis, the admixed local cattle were found to consist of several imported breeds, including Guernsey, Norwegian Red, and Holstein. To infer the influence of parental breeds on genomic regions, local ancestry mapping was performed based on the similarity of haplotypes. As a consequence, it appears that no genomic region has been under the complete influence of a specific parental breed. Nonetheless, the ancestry of Holstein-Friesians was substantial in most genomic regions (>80%. Furthermore, we examined the frequency of the most common haplotypes from parental breeds that have changed substantially in Kenyan crossbreds during admixture. The frequency of these haplotypes from parental breeds, which were likely to be selected in temperate regions, has deviated considerably from expected frequency in eleven genomic regions. Additionally, extended haplotype homozygosity based methods were applied to identify the regions responding to recent selection in crossbreds, called candidate regions, resulting in seven regions that appeared to be affected by Holstein-Friesians. However, some signatures of selection were less dependent on Holsteins-Friesians, suggesting evidence of adaptation in East Africa. The analysis of local ancestry is a useful approach to understand the detailed genomic structure and may reveal regions of the genome required for

  16. West-east transition from underplating to steep subduction in the India-Tibet collision zone revealed by receiver-function profiles

    Science.gov (United States)

    Shi, Danian; Zhao, Wenjin; Klemperer, Simon L.; Wu, Zhenhan; Mechie, James; Shi, Jianyu; Xue, Guangqi; Su, Heping

    2016-10-01

    Closely-spaced receiver-function profiles in the east-central India-Tibet collision zone reveal drastic west-east changes of the crustal and upper mantle structure. West of ∼91.5°E, we show the Indian crust-mantle boundary (Moho) extending subhorizontally from ∼50 km depth below sea level under the High Himalaya to ∼90 km under the central Lhasa terrane. Further north, this boundary transitions to become the top of the Indian lithospheric mantle and, becoming faint but still observable, it can be tracked continuously to ∼135 km depth near ∼31.5°N. The top of the Indian lithospheric mantle is clearly beneath the Tibetan Moho that is also a conspicuous boundary, undulatory at 60-75 km depth from the central Lhasa terrane to the north end of our profile at ∼34°N. This geometry is consistent with underthrusting of Indian lower crust and underplating of the Indian plate directly beneath southern Tibet. In contrast, east of ∼91.5°E, the Indian Moho is only seen under the southernmost margin of the Tibetan plateau, and eludes imaging from ∼50 km south of the Yarlung-Zangbo suture to the north. The Indian lower crust thins greatly and in places lacks a clear Moho. This is in contrast to our observation west of ∼91.5°E, that the Indian lower crust thickens northwards. A clear depression of the top of the Indian lower crust is also observed along west-east oriented profiles, centered above the region where the Indian Moho is not imaged. Our observations suggest that roll-back of the Indian lithospheric mantle has occurred east of ∼91.5°E, likely due to delamination associated with density instabilities in eclogitized Indian lower crust, with the center of foundering beneath the southern Lhasa terrane slightly east of 91.5°E.

  17. Human Population Admixture in Asia

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    Shuhua Xu

    2012-09-01

    Full Text Available Genetic admixture in human, the result of inter-marriage among people from different well-differentiated populations, has been extensively studied in the New World, where European colonization brought contact between peoples of Europe, Africa, and Asia and the Amerindian populations. In Asia, genetic admixing has been also prevalent among previously separated human populations. However, studies on admixed populations in Asia have been largely underrepresented in similar efforts in the New World. Here, I will provide an overview of population genomic studies that have been published to date on human admixture in Asia, focusing on population structure and population history.

  18. Effects of Admixed Titanium on Densification of 316L Stainless Steel Powder during Sintering

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    Aslam Muhammad

    2014-07-01

    Full Text Available Effects of admixed titanium on powder water atomized (PWA and powder gas atomized (PGA 316L stainless steel (SS have been investigated in terms of densification. PGA and PWA powders, having different shapes and sizes, were cold pressed and sintered in argon atmosphere at 1300°C. The admixed titanium compacts of PGA and PWA have shown significant effect on densification through formation of intermetallic compound and reducing porosity during sintering process. PWA, having particle size 8 μm, blended with 1wt% titanium has exhibited higher sintered density and shrinkage as compared to gas atomized powder compacts. Improved densification of titanium blended PGA and PWA 316L SS at sintering temperature 1300°C is probably due to enhanced diffusion kinetics resulting from stresses induced by concentration gradient in powder compacts.

  19. Gastric choriocarcinoma admixed with an α-fetoprotein-producing adenocarcinoma and separated adenocarcinoma

    Institute of Scientific and Technical Information of China (English)

    Bang Wool Eom; So-Youn Jung; Hongman Yoon; Myeong-Cherl Kook; Keun Won Ryu; Jun Ho Lee; Young-Woo Kim

    2009-01-01

    We report a case of gastric choriocarcinoma admixed with an α-fetoprotein (AFP)-producing adenocarcinoma .A 70-year-old man was hospitalized for gastric cancer that was detected during screening by esophagogastroduodenoscopy (EGD). Initial laboratory data showed the increased serum level of AFP and EGD revealed a 5-cm ulcerofungating mass in the greater curvature of the gastric antrum.The patient underwent radical subtotal gastrectomy with D2 lymph node dissection and Billroth Ⅱ gastrojejunostomy. Histopathological evaluation confirmed double primary gastric cancer: gastric choriocarcinoma admixed with an AFP-producing adenocarcinoma and separated adenocarcinoma. At 2 wk postoperatively, his human chorionic gonadotropin and AFP levels had reduced and six cycles of adjuvant chemotherapy were initiated. No recurrence or distant metastasis was observed at 4 years postoperatively.

  20. OSBPL10, RXRA and lipid metabolism confer African-ancestry protection against dengue haemorrhagic fever in admixed Cubans

    Science.gov (United States)

    Soares, Pedro; Garcia, Gissel; Perez, Ana B.; Aguirre, Eglys; Cavadas, Bruno; Regnault, Béatrice; Alvarez, Mayling; Ruiz, Didye; Guzman, Maria G.

    2017-01-01

    Ethnic groups can display differential genetic susceptibility to infectious diseases. The arthropod-born viral dengue disease is one such disease, with empirical and limited genetic evidence showing that African ancestry may be protective against the haemorrhagic phenotype. Global ancestry analysis based on high-throughput genotyping in admixed populations can be used to test this hypothesis, while admixture mapping can map candidate protective genes. A Cuban dengue fever cohort was genotyped using a 2.5 million SNP chip. Global ancestry was ascertained through ADMIXTURE and used in a fine-matched corrected association study, while local ancestry was inferred by the RFMix algorithm. The expression of candidate genes was evaluated by RT-PCR in a Cuban dengue patient cohort and gene set enrichment analysis was performed in a Thai dengue transcriptome. OSBPL10 and RXRA candidate genes were identified, with most significant SNPs placed in inferred weak enhancers, promoters and lncRNAs. OSBPL10 had significantly lower expression in Africans than Europeans, while for RXRA several SNPs may differentially regulate its transcription between Africans and Europeans. Their expression was confirmed to change through dengue disease progression in Cuban patients and to vary with disease severity in a Thai transcriptome dataset. These genes interact in the LXR/RXR activation pathway that integrates lipid metabolism and immune functions, being a key player in dengue virus entrance into cells, its replication therein and in cytokine production. Knockdown of OSBPL10 expression in THP-1 cells by two shRNAs followed by DENV2 infection tests led to a significant reduction in DENV replication, being a direct functional proof that the lower OSBPL10 expression profile in Africans protects this ancestry against dengue disease. PMID:28241052

  1. Silica Fume and Fly Ash Admixed Can Help to Improve the PRC Durability Combine Microscopic Analysis

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    Xiao Li-guang

    2016-01-01

    Full Text Available Silica fume/Fly ash RPC can greatly improve durability. When Silica fume to replace the same amount of 8% of the proportion of cement, re-mixed 15min of mechanically activated Fly ash content of 10%, by chloride ion flux detector measuring, complex doped than the reference RPC impermeability improved significantly; In addition, by using static nitrogen adsorption method showed, RPC internal pore structure determination, the hole integral volume was lower than the reference admixed RPC integral pore volume significantly; And combined SEM microscopic experimental methods, mixed of RPC internal structure and the formation mechanism analysis showed that, SF/FA complex fully embodies the synergy doped composites “Synergistic” principle.

  2. Die wall lubricated warm compaction behavior of non-lubricant admixed iron powders

    Institute of Scientific and Technical Information of China (English)

    YE Tu-ming; YI Jian-hong; CHEN Shi-jin; PENG Yuan-dong; LI Li-ya; XIA Qing-lin

    2005-01-01

    The phenomena of die wall lubricated warm compaction of non-lubricant admixed iron powders were researched, and its mechanism of densification was discussed. Water atomized powder obtained from the Wuhan Iron and Steel Corporation was used. With compacting and sintering, compared with cold compaction, the density of warm compacted samples increases by 0.07-0.22 g/cm 3 at the same pressed pressure. The maximum achievable green density of warm compacted samples is 7.12 g/cm 3 at 120 ℃, and the maximum sintered density is 7.18 g/cm 3 at 80 ℃. Compared with cold compaction, the ejection force of warm compaction is smaller; the maximum discrepancy is about 7 kN. The warm compacted mechanism of densification of iron powders can be obtained: heating the powder contributes to improving plastic deformation of powder particles, and accelerating the mutual filling and rearrangement of powder particles.

  3. Catalytic Cracking of Cycloparafifns Admixed with Oleifns:1. Single-Event Microkinetic (SEMK) Modeling

    Institute of Scientific and Technical Information of China (English)

    Xue Gaoping; Weng Huixin; Thybaut Joris W.; Marin Guy B.

    2014-01-01

    Single-event microkinetic (SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K-753 K in the absence of coke formation is enhanced. To keep consistency with the well-known carbenium ion chemistry, hydride transfer forming and consuming allylic carbenium ions in the aromatization of cycloparafifns are further investigated and differentiated. The reversibility of endocyclicβ-scission and cyclization reactions is reifned by accounting explicitly for the reacting oleifns and resulting cycloparafifns in the corresponding thermodynam-ics. 24 activation energies for the reactions involved in the cracking of cycloparafifns are obtained by the regression of 15 sets of experimental data upon taking the resulting 37 main cracking products, i. e., responses into account. The enhanced SEMK model can adequately describe the catalytic behavior of 37 main products with conversion and temperature.

  4. Some Insights to the Reuse of Dredged Marine Soils by Admixing with Activated Steel Slag

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    Chee-Ming Chan

    2014-01-01

    Full Text Available Regular dredging is necessary for the development of coastal regions and the maintenance of shipping channels. The dredging process dislodges sediments from the seabed, and the removed materials, termed dredged marine soils, are generally considered a geowaste for dumping. However, disposal of the dredged soils offshores can lead to severe and irreversible impact on the marine ecosystem, while disposal on land often incurs exorbitant costs with no guarantee of zero-contamination. It is therefore desirable to reuse the material, and one option is solidification with another industrial waste, that is, steel slag. This paper describes the exploratory work of admixing dredged marine soil with activated steel slag for improvement of the mechanical properties. An optimum activation concentration of NaOH was introduced to the soil-slag mixture for uniform blending. Specimens were prepared at different mix ratios then left to cure for up to 4 weeks. The unconfined compressive strength test was conducted to monitor the changes in strength at predetermined intervals. It was found that the strength does not necessarily increase with higher steel slag content, indicating an optimum slag content required for the maximum solidification effect to take place. Also, regardless of the slag content, longer curing time produces greater strength gain. In conclusion, steel slag addition to dredged sediments can effectively strengthen the originally weak soil structure by both the “cementation” and “filler” effects, though the combined effects were not distinguished in the present study.

  5. Free Active Chlorine in Sodium Hypochlorite Solutions Admixed with Octenidine, SmearOFF, Chlorhexidine, and EDTA.

    Science.gov (United States)

    Krishnan, Unni; Saji, Sreeja; Clarkson, Roger; Lalloo, Ratilal; Moule, Alex J

    2017-08-01

    The therapeutic effects of sodium hypochlorite (NaOCl) solutions are dependent on the levels of free available chlorine (FAC). Mixing these solutions with irrigants can result in significant reductions in FAC. Although the effect of some irrigants on FAC is known, the effect of other commonly used irrigants is not. Thus, the therapeutic ramifications of the concurrent use of these on the efficiency of NaOCl solutions is not known. Aliquots of 5.2% (w/v) NaOCl solutions were admixed in proportions of 90:10, 80:20, and 50:50 with the following irrigants: octenidine dihydrochloride (OCT); SmearOFF (Vista Dental Products, Racine, WI), 17% EDTA; and 0.2%, 2%, and 5% chlorhexidine (CHX) solutions. Changes in FAC were measured by iodometric titration. Statistical differences between means were determined using a post hoc Tukey analysis test after an analysis of variance. OCT appeared not to affect FAC and was significantly different than all other irrigants, except for 90:10 and 80:20 mixtures of low concentration (0.2%) CHX. CHX solutions showed a marked concentration- and mixture proportion-dependent detrimental effect on FAC. The reduction of FAC between different concentrations of CHX was statistically significant in 80:20 and 50:50 proportions, with 50:50 mixtures of 5% CHX having the greatest influence. Mixtures containing even small proportions of SmearOFF or EDTA exhibited significant losses in FAC. OCT has little effect on FAC and can be used concurrently with NaOCl solutions. Higher concentrations of CHX significantly affect FAC. Their combined use with NaOCl solutions should be avoided. EDTA and SmearOFF should not be mixed with NaOCl solutions. Copyright © 2017 American Association of Endodontists. All rights reserved.

  6. Crystal growth and optical properties of Gd admixed Ce-doepd Lu2Si2O7 single crystals

    Science.gov (United States)

    Horiai, Takahiko; Kurosawa, Shunsuke; Murakami, Rikito; Yamaji, Akihiro; Shoji, Yasuhiro; Ohashi, Yuji; Pejchal, Jan; Kamada, Kei; Yokota, Yuui; Yoshikawa, Akira

    2017-06-01

    Ce-doped Lu2Si2O7 scintillator contains radioactive isotope 176Lu which causes an unwanted intrinsic background signal. The development of scintillators with reduced Lu concentration were required in some applications. In this study, we developed the Gd admixed lutetium pyrosilicate, where the average ion radius at the rare earth site was similar to the Tm3+ ion radius, for which the RE2Si2O7 (RE=Tm, Yb, Lu) crystal structure is stable from room temperature to melting point. We have grown (Cex Lu1-x-y Gdy)2Si2O7 (x=0.01, y=0.00, 0.05, 0.10) single crystals. Their crystal systems were monoclinic with a space group C2/m. The absorption spectra revealed the energy transitions in Ce and Gd ions might be occurred. The light output was degraded and decay time was accelerated comparing the Gd 5% admixed sample with the Gd 10% one.

  7. Exome Sequencing in an Admixed Isolated Population Indicates NFXL1 Variants Confer a Risk for Specific Language Impairment

    NARCIS (Netherlands)

    Villanueva, P.; Nudel, R.; Hoischen, A.; Fernandez, M.A.; Simpson, N.H.; Gilissen, C.; Reader, R.H.; Jara, L.; Echeverry, M.M.; Francks, C.; Baird, G.; Conti-Ramsden, G.; O'Hare, A.; Bolton, P.F.; Hennessy, E.R.; Palomino, H.; Carvajal-Carmona, L.; Veltman, J.A.; Cazier, J.B.; Barbieri, Z. De; Fisher, S.E.; Newbury, D.F.

    2015-01-01

    Children affected by Specific Language Impairment (SLI) fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic

  8. Exome Sequencing in an Admixed Isolated Population Indicates NFXL1 Variants Confer a Risk for Specific Language Impairment

    NARCIS (Netherlands)

    Villanueva, P.; Nudel, R.; Hoischen, A.; Fernandez, M.A.; Simpson, N.H.; Gilissen, C.; Reader, R.H.; Jara, L.; Echeverry, M.M.; Francks, C.; Baird, G.; Conti-Ramsden, G.; O'Hare, A.; Bolton, P.F.; Hennessy, E.R.; Palomino, H.; Carvajal-Carmona, L.; Veltman, J.A.; Cazier, J.B.; Barbieri, Z. De; Fisher, S.E.; Newbury, D.F.

    2015-01-01

    Children affected by Specific Language Impairment (SLI) fail to acquire age appropriate language skills despite adequate intelligence and opportunity. SLI is highly heritable, but the understanding of underlying genetic mechanisms has proved challenging. In this study, we use molecular genetic techn

  9. Hypoplastic model for simulation of compressibility characteristics of cement-admixed Bangkok soft clay at high water content

    Science.gov (United States)

    Chattonjai, Piyachat

    2016-06-01

    The developed hypoplastic model for simulation of compressibility characteristics of cement-admixed Bangkok soft clay at high water content was proposed in this paper. By using unique equation, the model is able to predict the relationship between void ratio and vertical effective stress of different water and cement content of soil cement. For practically convenient utilization and understanding, the parameters of Q1 which represented to initial cement bonding of soil (the initial value of structure tensor at time = 0) and C2 which effected to the model stiffness on isotropic consolidation direction, at 45° for loading and 225° for unloading of stress response envelope, were proposed as the function of cement and water content by comparing with dry weight of soil. By numerical integration that satisfied one-dimensional settlement, the simulation results were directly compared with fifteen experimental results to verify the accuracy of the proposed model.

  10. Principal components analysis of population admixture.

    Directory of Open Access Journals (Sweden)

    Jianzhong Ma

    Full Text Available With the availability of high-density genotype information, principal components analysis (PCA is now routinely used to detect and quantify the genetic structure of populations in both population genetics and genetic epidemiology. An important issue is how to make appropriate and correct inferences about population relationships from the results of PCA, especially when admixed individuals are included in the analysis. We extend our recently developed theoretical formulation of PCA to allow for admixed populations. Because the sampled individuals are treated as features, our generalized formulation of PCA directly relates the pattern of the scatter plot of the top eigenvectors to the admixture proportions and parameters reflecting the population relationships, and thus can provide valuable guidance on how to properly interpret the results of PCA in practice. Using our formulation, we theoretically justify the diagnostic of two-way admixture. More importantly, our theoretical investigations based on the proposed formulation yield a diagnostic of multi-way admixture. For instance, we found that admixed individuals with three parental populations are distributed inside the triangle formed by their parental populations and divide the triangle into three smaller triangles whose areas have the same proportions in the big triangle as the corresponding admixture proportions. We tested and illustrated these findings using simulated data and data from HapMap III and the Human Genome Diversity Project.

  11. Population admixture, biological invasions and the balance between local adaptation and inbreeding depression

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Macel, M.; Wolfe, L.M.; Biere, A.

    2011-01-01

    When previously isolated populations meet and mix, the resulting admixed population can benefit from several genetic advantages, including increased genetic variation, the creation of novel genotypes and the masking of deleterious mutations. These admixture benefits are thought to play an important

  12. Population admixture, biological invasions and the balance between local adaptation and inbreeding depression

    NARCIS (Netherlands)

    Verhoeven, K.J.F.; Macel, M.; Wolfe, L.M.; Biere, A.

    2011-01-01

    When previously isolated populations meet and mix, the resulting admixed population can benefit from several genetic advantages, including increased genetic variation, the creation of novel genotypes and the masking of deleterious mutations. These admixture benefits are thought to play an important

  13. Autologous glioma cell vaccine admixed with interleukin-4 gene transfected fibroblasts in the treatment of patients with malignant gliomas

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    Torres-Trejo Alejandro

    2007-12-01

    Full Text Available Abstract Background The prognosis for malignant gliomas remains dismal. We addressed the safety, feasibility and preliminary clinical activity of the vaccinations using autologous glioma cells and interleukin (IL-4 gene transfected fibroblasts. Methods In University of Pittsburgh Cancer Institute (UPCI protocol 95-033, adult participants with recurrent glioblastoma multiforme (GBM or anaplastic astrocytoma (AA received gross total resection (GTR of the recurrent tumors, followed by two vaccinations with autologous fibroblasts retrovirally transfected with TFG-IL4-Neo-TK vector admixed with irradiated autologous glioma cells. In UPCI 99-111, adult participants with newly diagnosed GBM or AA, following GTR and radiation therapy, received two intradermal vaccinations with the TFG-IL4-Neo-TK-transfected fibroblasts admixed with type-1 dendritic cells (DC loaded with autologous tumor lysate. The participants were evaluated for occurrence of adverse events, immune response, and clinical response by radiological imaging. Results and Discussion In UPCI 95-033, only 2 of 6 participants received the vaccinations. Four other participants were withdrawn from the trial because of tumor progression prior to production of the cellular vaccine. However, both participants who received two vaccinations demonstrated encouraging immunological and clinical responses. Biopsies from the local vaccine sites from one participant displayed IL-4 dose-dependent infiltration of CD4+ as well as CD8+ T cells. Interferon (IFN-γ Enzyme-Linked Immuno-SPOT (ELISPOT assay in another human leukocyte antigen (HLA-A2+ participant demonstrated systemic T-cell responses against an HLA-A2-restricted glioma-associated antigen (GAA epitope EphA2883–891. Moreover, both participants demonstrated clinical and radiological improvement with no evidence of allergic encephalitis, although both participants eventually succumbed with the tumor recurrence. In 99-111, 5 of 6 enrolled participants

  14. Evaluation of the imputation performance of the program IMPUTE in an admixed sample from Mexico City using several model designs

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    Krithika S

    2012-05-01

    Full Text Available Abstract Background We explored the imputation performance of the program IMPUTE in an admixed sample from Mexico City. The following issues were evaluated: (a the impact of different reference panels (HapMap vs. 1000 Genomes on imputation; (b potential differences in imputation performance between single-step vs. two-step (phasing and imputation approaches; (c the effect of different INFO score thresholds on imputation performance and (d imputation performance in common vs. rare markers. Methods The sample from Mexico City comprised 1,310 individuals genotyped with the Affymetrix 5.0 array. We randomly masked 5% of the markers directly genotyped on chromosome 12 (n = 1,046 and compared the imputed genotypes with the microarray genotype calls. Imputation was carried out with the program IMPUTE. The concordance rates between the imputed and observed genotypes were used as a measure of imputation accuracy and the proportion of non-missing genotypes as a measure of imputation efficacy. Results The single-step imputation approach produced slightly higher concordance rates than the two-step strategy (99.1% vs. 98.4% when using the HapMap phase II combined panel, but at the expense of a lower proportion of non-missing genotypes (85.5% vs. 90.1%. The 1,000 Genomes reference sample produced similar concordance rates to the HapMap phase II panel (98.4% for both datasets, using the two-step strategy. However, the 1000 Genomes reference sample increased substantially the proportion of non-missing genotypes (94.7% vs. 90.1%. Rare variants ( Conclusions The program IMPUTE had an excellent imputation performance for common alleles in an admixed sample from Mexico City, which has primarily Native American (62% and European (33% contributions. Genotype concordances were higher than 98.4% using all the imputation strategies, in spite of the fact that no Native American samples are present in the HapMap and 1000 Genomes reference panels. The best balance of

  15. Modern humans did not admix with Neanderthals during their range expansion into Europe.

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    Mathias Currat

    2004-12-01

    Full Text Available The process by which the Neanderthals were replaced by modern humans between 42,000 and 30,000 before present is still intriguing. Although no Neanderthal mitochondrial DNA (mtDNA lineage is found to date among several thousands of Europeans and in seven early modern Europeans, interbreeding rates as high as 25% could not be excluded between the two subspecies. In this study, we introduce a realistic model of the range expansion of early modern humans into Europe, and of their competition and potential admixture with local Neanderthals. Under this scenario, which explicitly models the dynamics of Neanderthals' replacement, we estimate that maximum interbreeding rates between the two populations should have been smaller than 0.1%. We indeed show that the absence of Neanderthal mtDNA sequences in Europe is compatible with at most 120 admixture events between the two populations despite a likely cohabitation time of more than 12,000 y. This extremely low number strongly suggests an almost complete sterility between Neanderthal females and modern human males, implying that the two populations were probably distinct biological species.

  16. Prediction of permeability of cement-admixed soft clay using resistivity and time-domain IP measurements

    Science.gov (United States)

    Latt, Khin M. M.; Giao, P. H.

    2017-02-01

    Permeability is one of the most important petrophysical parameters, which unfortunately is quite difficult to be tested and estimated, particularly for the fine-grained soils and mixed soils. Prediction of permeability based on geophysical measurements is currently one of the most challenging issues in petrophysics. There have been recently reported some empirical relationships between permeability, resistivity and spectral induced polarization (SIP) parameters for a porous medium. However, the disadvantage of this approach is the very scarcity of SIP data as most of practical measurements are time-domain IP. In this study, a detailed overview of permeability prediction models using resistivity and spectral IP data was made. More than that, an innovative approach using resistivity and time-domain IP measurements to predict permeability of cement-admixed Bangkok clay was proposed and successfully applied for tested samples based on measurements of resistivity and time-domain IP data. A good amount of geotechnical and geophysical tests was conducted to investigate the time-dependent development of strength, porosity, and permeability of cement-mixed Bangkok soft clay samples during a 28-day curing process. The permeability predicted by resistivity and chargeability model matched well with permeability measured by consolidation testing. In addition, a series of correlations between unconfined compressive strength, porosity and permeability as measured by geotechnical testing and resistivity and chargeability as measured by geophysical testing were found.

  17. Treatment surfaces with atomic oxygen excited in dielectric barrier discharge plasma of O2 admixed to N2

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    E. V. Shun'ko

    2012-06-01

    Full Text Available This paper describes the increase in surface energy of substrates by their treatment with gas composition generated in plasmas of DBD (Dielectric Barrier Discharge in O2 admixed with N2. Operating gas dissociation and excitation was occurred in plasmas developed in two types of reactors of capacitively-coupled dielectric barrier configurations: coaxial cylindrical, and flat rectangular. The coaxial cylindrical type comprised an inner cylindrical electrode encapsulated in a ceramic sheath installed coaxially inside a cylindrical ceramic (quartz tube passing through an annular outer electrode. Components of the flat rectangular type were a flat ceramic tube of a narrow rectangular cross section supplied with two flat electrodes mounted against one another outside of the long parallel walls of this tube. The operating gas, mixture of N2 and O2, was flowing in a completely insulated discharge gap formed between insulated electrodes of the devices with an average velocity of gas inlet of about 7 to 9 m/s. Dielectric barrier discharge plasma was excited in the operating gaps with a bipolar pulse voltage of about 6 kV for 2 ms at 50 kHz repetition rate applied to the electrodes of the coaxial device, and of about 14 kV for 7 ms at 30 kHz repetition rate for the flat linear device. A lifetime of excited to the 2s22p4(1S0 state in DBD plasma and streaming to the surfaces with a gas flow atomic oxygen, responsible presumably for treating surfaces, exceeded 10 ms in certain cases, that simplified its separation from DBD plasma and delivery to substrates. As it was found in particular, surfaces of glass and some of polymers revealed significant enhancement in wettability after treatment.

  18. Studies on the de/re-hydrogenation characteristics of nanocrystalline MgH2 admixed with carbon nanofibres

    Science.gov (United States)

    Shahi, Rohit R.; Raghubanshi, Himanshu; Shaz, M. A.; Srivastava, O. N.

    2012-09-01

    In the present investigation, we have synthesized different morphologies of carbon nanofibres (CNFs) to investigate their catalytic effect on the hydrogenation characteristics of 25 h ball-milled MgH2 (nano MgH2). The TEM analysis reveals that 25 h of ball-milling leads to the formation of nanocrystalline particles with size ranging between 10 and 20 nm. Different morphologies of CNFs were synthesized by catalytic thermal decomposition of acetylene (C2H2) gas over LaNi5 alloy. Helical carbon nanofibers (HCNFs) were formed at a temperature 650 °C. By increasing the synthesis temperature to 750 °C, planar carbon nanofibres were formed. In order to explore the effectiveness of CNFs towards lowering the decomposition temperature, TPD experiments (at heating rate 5 °C/min) were performed for nano MgH2 with and without CNFs. It was found that the decomposition temperature is reduced to ~334 and ~300 °C from 367 °C for the PCNF and HCNF catalysed nano MgH2. It is also found that HCNF admixed nano MgH2 absorbs ~5.25 wt% within 10 min as compared with pristine nano MgH2, which absorbs only ~4.2 % within the same time and same condition of temperature and pressure. Thus the HCNF possesses better catalytic activity than PCNF. These different levels of improvement in hydrogenation properties of HCNF catalysed nano MgH2 is attributed to the morphology of the CNFs.

  19. Tat peptide-admixed elastic liposomal formulation of hirsutenone for the treatment of atopic dermatitis in Nc/Nga mice

    Directory of Open Access Journals (Sweden)

    Kang MJ

    2011-10-01

    Full Text Available Myung Joo Kang1, Jae Yoon Eum1, Mi Sook Jeong2, Sang Han Park1, Ki Young Moon1, Mean Hyung Kang1, Min Soo Kim1, Sun Eun Choi1, Min Won Lee1, Do Ik Lee1, Hyoweon Bang2, Chung Soo Lee2, Seong Soo Joo3, Kapsok Li2, Mi-Kyung Lee2, Seong Jun Seo2, Young Wook Choi11College of Pharmacy, ChungAng University, Heuksuk-dong, Dongjak-gu, Seoul, 2College of Medicine, Chung-Ang University, Heuksukdong, Dongjak-gu, Seoul, 3Division of Marine Molecular Biotechnology, Gangneung-Wonju National University, Gangneung, South KoreaBackground: The aim of the present study was to enhance a topical delivery of hirsutenone (HST, a naturally occuring immunomodulator, employing Tat peptide-admixed elastic liposomes (EL/T.Methods: HST-loaded EL, consisting of phosphatidylcholine and Tween 80 (85:15 w/w%, were prepared using thin film hydration method. By adding Tat peptide to EL (0.16 w/w%, EL/T were formulated. The in vitro skin permeation of HST was examined using a Franz diffusion cell mounted with depilated mouse skin. Lesions for atopic dermatitis (AD were induced by a topical application of diphenylcyclopropenone to NC/Nga mice. Therapeutic improvements of AD were evaluated by clinical skin severity scores. Immunological analyses on inducible nitric oxide synthase and cyclooxygenase-2 levels in the skin and interleukin (IL-4, IL-13, immunoglobulin E, and eosinophil levels in the blood were also performed.Results: EL systems were superior to conventional cream, revealing greater flux values in a permeation study. The addition of Tat peptide further increased the skin permeation of HST. In an efficacy study with AD-induced NC/Nga mice, an HST-containing EL/T formulation brought a significant improvement in both skin severity score and immune-related responses for the levels of nitric oxide synthase, cyclooxygenase-2, IL-4, IL-13, immunoglobulin E, and eosinophils.Conclusion: A novel EL/T formulation was successfully developed for topical delivery of HST to treat AD

  20. The Relation Between Inflation in Type-I and Type-II Error Rate and Population Divergence in Genome-Wide Association Analysis of Multi-Ethnic Populations.

    Science.gov (United States)

    Derks, E M; Zwinderman, A H; Gamazon, E R

    2017-02-10

    Population divergence impacts the degree of population stratification in Genome Wide Association Studies. We aim to: (i) investigate type-I error rate as a function of population divergence (FST) in multi-ethnic (admixed) populations; (ii) evaluate the statistical power and effect size estimates; and (iii) investigate the impact of population stratification on the results of gene-based analyses. Quantitative phenotypes were simulated. Type-I error rate was investigated for Single Nucleotide Polymorphisms (SNPs) with varying levels of FST between the ancestral European and African populations. Type-II error rate was investigated for a SNP characterized by a high value of FST. In all tests, genomic MDS components were included to correct for population stratification. Type-I and type-II error rate was adequately controlled in a population that included two distinct ethnic populations but not in admixed samples. Statistical power was reduced in the admixed samples. Gene-based tests showed no residual inflation in type-I error rate.

  1. Evaluation of the effect of 16% carbamide peroxide gel (Nite White on mercury release from Iranian and foreign spherical and admixed amalgams by cold vapor atomic absorption method

    Directory of Open Access Journals (Sweden)

    Kasraie Sh.

    2008-04-01

    Full Text Available Background and Aim: Nowadays, esthetic dentistry has become an important part of modern dentistry. Bleaching is considered as a conservative, safe and effective way for treatment of discolored teeth. Although bleaching is commonly used on anterior teeth, the bleaching gel may come into contact with patient's former amalgam restorations and result in corrosive effects, dissolution of amalgam phases and increasing release of mercury. Mercury released from dental amalgam during mouthguard bleaching can be absorbed and increase the total mercury body burden. The aim of this study was to determine the amount of mercury released from Iranian and foreign brands of amalgams with spherical and admixed particles, polished and unpolished, after 16%carbamide peroxide gel application.Materials and Methods: This experimental in vitro study was performed on 256 Iranian and foreign amalgam samples with spherical and admixed particles. The provided samples were put in distilled water and classified according to the type of amalgam, shape of particles and quality of surface polishing. The test samples were placed in Nite White 16% carbamid peroxide gel and control samples were put in phosphate buffer (Ph=6.5 for 14 and 28 hours. The amount of released mercury was calculated using AVA-440 Mercury Analysis System (Thermo Jarrell Ash model SH/229 with cold-vapor atomic absorption. Data were analyzed using t-test, four way and three way ANOVA tests with P<0.05 as the level of significance.Results: 16% Nite White carbamide peroxide gel caused a significant increase in amount of mercury released from amalgams in all groups (P<0.05. Mercury release from Iranian amalgam was higher than that from the foreign brands (P<0.05. There was no significant difference in mercury released from spherical and admixed amalgams (P>0.05. The amount of mercury released from Iranian and foreign amalgams was time dependent (P<0.05. Furthermore, the amount of mercury released from

  2. Population genetic inference from personal genome data: impact of ancestry and admixture on human genomic variation.

    Science.gov (United States)

    Kidd, Jeffrey M; Gravel, Simon; Byrnes, Jake; Moreno-Estrada, Andres; Musharoff, Shaila; Bryc, Katarzyna; Degenhardt, Jeremiah D; Brisbin, Abra; Sheth, Vrunda; Chen, Rong; McLaughlin, Stephen F; Peckham, Heather E; Omberg, Larsson; Bormann Chung, Christina A; Stanley, Sarah; Pearlstein, Kevin; Levandowsky, Elizabeth; Acevedo-Acevedo, Suehelay; Auton, Adam; Keinan, Alon; Acuña-Alonzo, Victor; Barquera-Lozano, Rodrigo; Canizales-Quinteros, Samuel; Eng, Celeste; Burchard, Esteban G; Russell, Archie; Reynolds, Andy; Clark, Andrew G; Reese, Martin G; Lincoln, Stephen E; Butte, Atul J; De La Vega, Francisco M; Bustamante, Carlos D

    2012-10-05

    Full sequencing of individual human genomes has greatly expanded our understanding of human genetic variation and population history. Here, we present a systematic analysis of 50 human genomes from 11 diverse global populations sequenced at high coverage. Our sample includes 12 individuals who have admixed ancestry and who have varying degrees of recent (within the last 500 years) African, Native American, and European ancestry. We found over 21 million single-nucleotide variants that contribute to a 1.75-fold range in nucleotide heterozygosity across diverse human genomes. This heterozygosity ranged from a high of one heterozygous site per kilobase in west African genomes to a low of 0.57 heterozygous sites per kilobase in segments inferred to have diploid Native American ancestry from the genomes of Mexican and Puerto Rican individuals. We show evidence of all three continental ancestries in the genomes of Mexican, Puerto Rican, and African American populations, and the genome-wide statistics are highly consistent across individuals from a population once ancestry proportions have been accounted for. Using a generalized linear model, we identified subtle variations across populations in the proportion of neutral versus deleterious variation and found that genome-wide statistics vary in admixed populations even once ancestry proportions have been factored in. We further infer that multiple periods of gene flow shaped the diversity of admixed populations in the Americas-70% of the European ancestry in today's African Americans dates back to European gene flow happening only 7-8 generations ago.

  3. Genetic restoration of a stocked brown trout Salmo trutta population using microsatellite DNA analysis of historical and contemporary samples

    DEFF Research Database (Denmark)

    Hansen, Michael Møller; Bekkevold, Dorte; Jensen, L.F.;

    2006-01-01

    -admixed individuals nevertheless remained in the wild-caught samples. In addition, two resident populations in isolated tributaries were found to be indigenous. The indigenous anadromous individuals from the Skjern River were unlikely to have been recruited from either the isolated tributary populations......1. Gene flow from domesticated to wild populations is a major threat to wild salmonid fish. However, few studies have addressed how populations could be restored after admixture has occurred. We analysed the prospects for restoring the previously intensively stocked brown trout population...... of the Skjern River, Denmark, by identifying remaining non-admixed individuals to be used for supportive breeding. 2. We analysed microsatellite DNA markers in historical (1940-50s) and contemporary (1992-2004) samples from the Skjern River system, from the strain of domesticated trout previously used...

  4. Managerial Intuition across Cultures: Beyond a "West-East Dichotomy"

    Science.gov (United States)

    Wozniak, Anna

    2006-01-01

    Purpose: Studies investigating intuition from a cultural and cross-cultural perspective have a long tradition in various disciplines but, due to the increased internationalization of business, an understanding of the mental lives of other cultures became one of the priorities of management practitioners and theoreticians. Cultures of…

  5. Uniparental ancestry markers in Chilean populations

    Directory of Open Access Journals (Sweden)

    Camilla Dutra Vieira-Machado

    Full Text Available Abstract The presence of Native Americans, Europeans, and Africans has led to the development of a multi-ethnic, admixed population in Chile. This study aimed to contribute to the characterization of the uniparental genetic structure of three Chilean regions. Newborns from seven hospitals in Independencia, Providencia, Santiago, Curicó, Cauquenes, Valdívia, and Puerto Montt communes, belonging to the Chilean regions of Santiago, Maule, and Los Lagos, were studied. The presence of Native American mitochondrial DNA (mtDNA haplogroups and two markers present in the non-recombinant region of the Y chromosome, DYS199 and DYS287, indicative of Native American and African ancestry, respectively, was determined. A high Native American matrilineal contribution and a low Native American and African patrilineal contributions were found in all three studied regions. As previously found in Chilean admixed populations, the Native American matrilineal contribution was lower in Santiago than in the other studied regions. However, there was an unexpectedly higher contribution of Native American ancestry in one of the studied communes in Santiago, probably due to the high rate of immigration from other regions of the country. The population genetic sub-structure we detected in Santiago using few uniparental markers requires further confirmation, owing to possible stratification for autosomal and X-chromosome markers.

  6. 新建茶园不同间作模式及覆盖遮阴效应比较研究——种植模式Ⅰ:茶行东西走向%Comparative Study of Intercropping Different Crops and Shading Effects in Young Tea Garden under Planting PatternⅠ : West -East Direction of Tea Rows

    Institute of Scientific and Technical Information of China (English)

    吕小营; 欧阳石光; 张丽霞; 黄晓琴; 向勤锃

    2012-01-01

    The effects of intercropping with maize, soybean, maize plus soybean respectively and shading on the ecological environment, germination of tea seeds, growth and photosynthesis of tea plants were studied in young tea plantation with west - east direction of tea rows. The results were as follows. (1) When the tea plants were cultivated in east - west direction, the effect of intercropping soybean was the best. The temperature of tea plantation reduced 3.1-3.6X. ?the light intensity decreased by 86.4% -90.4% ; daily mean air humidity increased by 10. 6% ; soil moisture increased by 13. 0% ; daily mean photosynthetic rate was 2. 7 times of the control's; the survival rate, plant height, stem diameter and leaf area per plant increased by 32.3% , 60.5% , 33.1% and 218.9% respectively. (2) Compared to shading, intercropping could increase the air humidity more.%研究了在东西走向的茶行中分别间作玉米、大豆、玉米+大豆以及覆盖遮阴对新建茶园生态环境、茶籽萌发、茶苗生长以及光合作用的影响.结果表明:(1)茶行东西走向以间作大豆的效果最好.间作大豆的茶园温度可降低3.1~3.6℃,光照强度降低86.4%~90.4%,日均相对湿度增加10.6%,土壤含水量增加13.0%,日均光合速率为对照的2.7倍,茶苗成活率、株高、茎粗、单株叶面积分别增加32.3%、60.5%、33.1%、218.9%.(2)与覆盖遮阴相比,间作更能提高茶园的空气湿度.

  7. Cohort profile: the Baependi Heart Study—a family-based, highly admixed cohort study in a rural Brazilian town

    Science.gov (United States)

    Negrão, André B; Horimoto, Andréa R V R; Duarte, Nubia E; Gonçalves, Guilherme C; Soler, Júlia M P; Lorenzi-Filho, Geraldo; Taporoski, Tâmara P; de Oliveira, Camila M; Alvim, Rafael O; Pereira, Alexandre C

    2016-01-01

    Purpose Cardiovascular disease (CVD) is a major challenge to global health. The same epidemiological transition scenario is replayed as countries develop, but with variations based on environment, culture and ethnic mixture. The Baependi Heart Study was set up in 2005 to develop a longitudinal family-based cohort study that reflects on some of the genetic and lifestyle-related peculiarities of the Brazilian populations, in order to evaluate genetic and environmental influences on CVD risk factor traits. Participants Probands were recruited in Baependi, a small rural town in the state of Minas Gerais, Brazil, following by first-degree and then increasingly more distant relatives. The first follow-up wave took place in 2010, and the second in 2016. At baseline, the study evaluated 1691 individuals across 95 families. Cross-sectional data have been collected for 2239 participants. Findings to date Environmental and lifestyle factors and measures relevant to cardiovascular health have been reported. Having expanded beyond cardiovascular health outcomes, the phenotype datasets now include genetics, biochemistry, anthropometry, mental health, sleep and circadian rhythms. Many of these have yielded heritability estimates, and a shared genetic background of anxiety and depression has recently been published. In spite of universal access to electricity, the population has been found to be strongly shifted towards morningness compared with metropolitan areas. Future plans A new follow-up, marking 10 years of the study, is ongoing in 2016, in which data are collected as in 2010 (with the exception of the neuropsychiatric protocol). In addition to this, a novel questionnaire package collecting information about intelligence, personality and spirituality is being planned. The data set on circadian rhythms and sleep will be amended through additional questionnaires, actimetry, home sleep EEG recording and dim light melatonin onset (DLMO) analysis. Finally, the anthropometric

  8. CYP2D6 variability in populations from Venezuela.

    Science.gov (United States)

    Moreno, Nancy; Flores-Angulo, Carlos; Villegas, Cecilia; Mora, Yuselin

    2016-12-01

    CYP2D6 is an important cytochrome P450 enzyme that plays an important role in the metabolism of about 25% of currently prescribed drugs. The presence of polymorphisms in the CYP2D6 gene may modulate enzyme level and activity, thereby affecting individual responses to pharmacological treatments. The most prevalent diseases in the admixed population from Venezuela are cardiovascular and cancer, whereas viral, bacterial and parasitic diseases, particularly malaria, are prevalent in Amerindian populations; in the treatment of these diseases, several drugs that are metabolized by CYP2D6 are used. In this work, we reviewed the data on CYP2D6 variability and predicted metabolizer phenotypes, in healthy volunteers of two admixed and five Amerindian populations from Venezuela. The Venezuelan population is very heterogeneous as a result of the genetic admixture of three major ethnical components: Europeans, Africans and Amerindians. There are noticeable inter-regional and inter-population differences in the process of mixing of this population. Hitherto, there are few published studies in Venezuela on CYP2D6; therefore, it is necessary to increase research in this regard, in particular to develop studies with a larger sample size. There is a considerable amount of work remaining before CYP2D6 is integrated into clinical practice in Venezuela.

  9. Population genetic structure of traditional populations in the Peruvian Central Andes and implications for South American population history.

    Science.gov (United States)

    Cabana, Graciela S; Lewis, Cecil M; Tito, Raúl Y; Covey, R Alan; Cáceres, Angela M; Cruz, Augusto F De La; Durand, Diana; Housman, Genevieve; Hulsey, Brannon I; Iannacone, Gian Carlo; López, Paul W; Martínez, Rolando; Medina, Ángel; Dávila, Olimpio Ortega; Pinto, Karla Paloma Osorio; Santillán, Susan I Polo; Domínguez, Percy Rojas; Rubel, Meagan; Smith, Heather F; Smith, Silvia E; Massa, Verónica Rubín de Celis; Lizárraga, Beatriz; Stone, Anne C

    2014-01-01

    Molecular-based characterizations of Andean peoples are traditionally conducted in the service of elucidating continent-level evolutionary processes in South America. Consequently, genetic variation among "western" Andean populations is often represented in relation to variation among "eastern" Amazon and Orinoco River Basin populations. This west-east contrast in patterns of population genetic variation is typically attributed to large-scale phenomena, such as dual founder colonization events or differing long-term microevolutionary histories. However, alternative explanations that consider the nature and causes of population genetic diversity within the Andean region remain underexplored. Here we examine population genetic diversity in the Peruvian Central Andes using data from the mtDNA first hypervariable region and Y-chromosome short tandem repeats among 17 newly sampled populations and 15 published samples. Using this geographically comprehensive data set, we first reassessed the currently accepted pattern of western versus eastern population genetic structure, which our results ultimately reject: mtDNA population diversities were lower, rather than higher, within Andean versus eastern populations, and only highland Y-chromosomes exhibited significantly higher within-population diversities compared with eastern groups. Multiple populations, including several highland samples, exhibited low genetic diversities for both genetic systems. Second, we explored whether the implementation of Inca state and Spanish colonial policies starting at about ad 1400 could have substantially restructured population genetic variation and consequently constitute a primary explanation for the extant pattern of population diversity in the Peruvian Central Andes. Our results suggest that Peruvian Central Andean population structure cannot be parsimoniously explained as the sole outcome of combined Inca and Spanish policies on the region's population demography: highland populations

  10. Admixture estimates for the population of Havana City.

    Science.gov (United States)

    Cintado, A; Companioni, O; Nazabal, M; Camacho, H; Ferrer, A; De Cossio, M E Fernandez; Marrero, A; Ale, M; Villarreal, A; Leal, L; Casalvilla, R; Benitez, J; Novoa, L; Diaz-Horta, O; Dueñas, M

    2009-01-01

    The Cuban population is essentially a result of the admixture between Spanish, West African and, to a lesser degree, Amerindian tribes that inhabited the island. The study analysed the genetic structure of the three principal ethnic groups from Havana City, and the contribution of parental populations to its genetic pool. According to genealogical information and anthropological traits, 206 subjects were classified as Mulatto, of Spanish decent or of African descent. Seventeen Ancestry Informative Markers, with high difference in frequency between parental populations, were selected to estimate individual and group admixture proportions. The statistical analyses were performed using the ADMIX, ADMIX95 and STRUCTURE 2.1 packages. The results demonstrate a high level of European and African admixture in Mulattos (57-59% European; 41-43% West African). The European contribution was higher in those of Spanish descent (85%) while in those of African descent, the West African contribution ranged between 74% and 76%. Genetic structure was only detected in Mulattos and those of African descent. An Amerindian contribution was not detectable in the studied sample. Our findings indicate the existence of admixture and genetic structure in the population of Havana City. This study represents one of the first steps towards understanding Cuban population admixture in order to produce successful experimental designs for admixture mapping.

  11. Analyzing the genetic structure of the Tepehua in relation to other neighbouring Mesoamerican populations. A study based on allele frequencies of STR markers.

    Science.gov (United States)

    González-Martín, Antonio; Gorostiza, Amaya; Rangel-Villalobos, Héctor; Acunha, Víctor; Barrot, Carme; Sánchez, Cristina; Ortega, Monserrat; Gené, Manel; Calderón, Rosario

    2008-01-01

    We report data on the genetic variation of the Tepehua population based on 15 autosomal microsatellites. The Tepehua, whose language belongs to the Totonac family, are settled throughout the Sierra Madre Oriental in Mexico and constitute a group in demographic decline. The results suggest that the Tepehua population remained isolated throughout a large part of its history. Phylogenetic analyses performed with other indigenous and admixed populations of Mesoamerica allow us to address their biological history. The results suggest a genetic affinity between the Tepehua and the Huastecos due to their previous shared history, and a certain degree of differentiation from the Otomões groups and the Choles (who are of Mayan origin). A clear genetic differentiation is also apparent between native and admixed populations within the greater region of Mesoamerica. It is currently accepted that the genetic composition of the American populations fits a trihybrid model of admixture. The genetic structure based on comparison of 34 populations throughout the continent (9 indigenous and 23 admixed) using hierarchical cluster analysis with an explained variance of 61.17% suggests the existence of four large groups distinguished according to the degree of admixture between Amerindians, Europeans, and Africans. (c) 2008 Wiley-Liss, Inc.

  12. Ancestral informative marker selection and population structure visualization using sparse Laplacian eigenfunctions.

    Directory of Open Access Journals (Sweden)

    Jun Zhang

    Full Text Available Identification of a small panel of population structure informative markers can reduce genotyping cost and is useful in various applications, such as ancestry inference in association mapping, forensics and evolutionary theory in population genetics. Traditional methods to ascertain ancestral informative markers usually require the prior knowledge of individual ancestry and have difficulty for admixed populations. Recently Principal Components Analysis (PCA has been employed with success to select SNPs which are highly correlated with top significant principal components (PCs without use of individual ancestral information. The approach is also applicable to admixed populations. Here we propose a novel approach based on our recent result on summarizing population structure by graph laplacian eigenfunctions, which differs from PCA in that it is geometric and robust to outliers. Our approach also takes advantage of the priori sparseness of informative markers in the genome. Through simulation of a ring population and the real global population sample HGDP of 650K SNPs genotyped in 940 unrelated individuals, we validate the proposed algorithm at selecting most informative markers, a small fraction of which can recover the similar underlying population structure efficiently. Employing a standard Support Vector Machine (SVM to predict individuals' continental memberships on HGDP dataset of seven continents, we demonstrate that the selected SNPs by our method are more informative but less redundant than those selected by PCA. Our algorithm is a promising tool in genome-wide association studies and population genetics, facilitating the selection of structure informative markers, efficient detection of population substructure and ancestral inference.

  13. Human population structure detection via multilocus genotype clustering

    Directory of Open Access Journals (Sweden)

    Starmer Joshua

    2007-06-01

    Full Text Available Abstract Background We describe a hierarchical clustering algorithm for using Single Nucleotide Polymorphism (SNP genetic data to assign individuals to populations. The method does not assume Hardy-Weinberg equilibrium and linkage equilibrium among loci in sample population individuals. Results We show that the algorithm can assign sample individuals highly accurately to their corresponding ethnic groups in our tests using HapMap SNP data and it is also robust to admixed populations when tested with Perlegen SNP data. Moreover, it can detect fine-scale population structure as subtle as that between Chinese and Japanese by using genome-wide high-diversity SNP loci. Conclusion The algorithm provides an alternative approach to the popular STRUCTURE program, especially for fine-scale population structure detection in genome-wide association studies. This is the first successful separation of Chinese and Japanese samples using random SNP loci with high statistical support.

  14. Patterns of admixture and population structure in native populations of Northwest North America.

    Science.gov (United States)

    Verdu, Paul; Pemberton, Trevor J; Laurent, Romain; Kemp, Brian M; Gonzalez-Oliver, Angelica; Gorodezky, Clara; Hughes, Cris E; Shattuck, Milena R; Petzelt, Barbara; Mitchell, Joycelynn; Harry, Harold; William, Theresa; Worl, Rosita; Cybulski, Jerome S; Rosenberg, Noah A; Malhi, Ripan S

    2014-08-01

    The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.

  15. Patterns of admixture and population structure in native populations of Northwest North America.

    Directory of Open Access Journals (Sweden)

    Paul Verdu

    2014-08-01

    Full Text Available The initial contact of European populations with indigenous populations of the Americas produced diverse admixture processes across North, Central, and South America. Recent studies have examined the genetic structure of indigenous populations of Latin America and the Caribbean and their admixed descendants, reporting on the genomic impact of the history of admixture with colonizing populations of European and African ancestry. However, relatively little genomic research has been conducted on admixture in indigenous North American populations. In this study, we analyze genomic data at 475,109 single-nucleotide polymorphisms sampled in indigenous peoples of the Pacific Northwest in British Columbia and Southeast Alaska, populations with a well-documented history of contact with European and Asian traders, fishermen, and contract laborers. We find that the indigenous populations of the Pacific Northwest have higher gene diversity than Latin American indigenous populations. Among the Pacific Northwest populations, interior groups provide more evidence for East Asian admixture, whereas coastal groups have higher levels of European admixture. In contrast with many Latin American indigenous populations, the variance of admixture is high in each of the Pacific Northwest indigenous populations, as expected for recent and ongoing admixture processes. The results reveal some similarities but notable differences between admixture patterns in the Pacific Northwest and those in Latin America, contributing to a more detailed understanding of the genomic consequences of European colonization events throughout the Americas.

  16. Reconstructing the population genetic history of the Caribbean.

    Directory of Open Access Journals (Sweden)

    Andrés Moreno-Estrada

    2013-11-01

    Full Text Available The Caribbean basin is home to some of the most complex interactions in recent history among previously diverged human populations. Here, we investigate the population genetic history of this region by characterizing patterns of genome-wide variation among 330 individuals from three of the Greater Antilles (Cuba, Puerto Rico, Hispaniola, two mainland (Honduras, Colombia, and three Native South American (Yukpa, Bari, and Warao populations. We combine these data with a unique database of genomic variation in over 3,000 individuals from diverse European, African, and Native American populations. We use local ancestry inference and tract length distributions to test different demographic scenarios for the pre- and post-colonial history of the region. We develop a novel ancestry-specific PCA (ASPCA method to reconstruct the sub-continental origin of Native American, European, and African haplotypes from admixed genomes. We find that the most likely source of the indigenous ancestry in Caribbean islanders is a Native South American component shared among inland Amazonian tribes, Central America, and the Yucatan peninsula, suggesting extensive gene flow across the Caribbean in pre-Columbian times. We find evidence of two pulses of African migration. The first pulse--which today is reflected by shorter, older ancestry tracts--consists of a genetic component more similar to coastal West African regions involved in early stages of the trans-Atlantic slave trade. The second pulse--reflected by longer, younger tracts--is more similar to present-day West-Central African populations, supporting historical records of later transatlantic deportation. Surprisingly, we also identify a Latino-specific European component that has significantly diverged from its parental Iberian source populations, presumably as a result of small European founder population size. We demonstrate that the ancestral components in admixed genomes can be traced back to distinct sub

  17. Transferrin gene polymorphisms and population genetic studies of Atlantic cod (Gadus morhua)

    Institute of Scientific and Technical Information of China (English)

    Berhan Asmamaw

    2016-01-01

    Objective:To detect single nucleotide polymorphisms (SNPs) in the cod transferrin gene by comparing the sequences from Norwegian (North East Atlantic Ocean) and Canadian (North West Atlantic Ocean) specimen, and to quantify the genetic variation and differentiation in East and West Atlantic cod populations. Methods:cDNA sequences between individuals of Canadian (North West Atlantic Ocean) and Norwegian (North East Atlantic Ocean) origin were aligned. Allele frequencies of theSNPs were used to discriminate the different Atlantic cod populations in West/East Atlantic Ocean, and the Baltic Sea. Results: The sequence alignment detected19SNPs, of which 18 of them resulted in amino acid changes in the transferrin protein. Nonsynonymous to synonymous site substitution ratio (dn/ds) was by far greater than 1 providing an evidence for the existence of positive selection. The West Atlantic cod populations showed high values of heterozygosity and the Baltic populations were found to be inbred. Conclusions: This study identified and indicated transferrin gene polymorphisms that can be used for population differentiations.

  18. Population expanding with the phalanx model and lineages split by environmental heterogeneity: a case study of Primula obconica in subtropical China.

    Directory of Open Access Journals (Sweden)

    Hai-Fei Yan

    Full Text Available BACKGROUND: Current and historical events have both affected the current distribution patterns and intraspecific divergence of plants. While numerous studies have focused on the Qinghai-Tibetan Plateau (QTP, the impacts of such events on the flora of subtropical China remain poorly understood. Subtropical China is famous for its highly complex topography and the limited impact from glaciation during the Pleistocene; this may have resulted in a different genetic legacy for species in this region compared to fully glaciated areas. METHODOLOGY/PRINCIPAL FINDINGS: We used plastid and nuclear DNA sequence data and distribution modeling to analyze the divergence patterns and demographic history of Primula obconica Hance, a widespread herbaceous montane species in subtropical China. The phylogenetic analysis revealed two major lineages (lineage A and lineage B, representing a west-east split into the Yunnan and Eastern groups, and the Sichuan and Central groups, respectively. The Eastern and Central groups comprised relatively new derived haplotypes. Nested Clade Analysis and Bayesian Skyline Plot analyses both indicated that P. obconica mainly experienced a gradual expansion of populations. In addition, the simulated distribution of P. obconica during the Last Glacial Maximum was slightly larger than its present-day distribution. CONCLUSION/SIGNIFICANCE: Our results are the first to identify a west-east migration of P. obconica. The gradual expansion pattern and a larger potential distribution range in cold periods detected for P. obconica indicate that the population expansion of this species is consistent with the phalanx model. In addition, the current patterns of genetic differentiation have persisted as a result of the extensive environmental heterogeneity that exists in subtropical China.

  19. Analysis of genetic structure and relationship among nine indigenous Chinese chicken populations by the Structure program

    Indian Academy of Sciences (India)

    H. F. Li; W. Han; Y. F. Zhu; J. T. Shu; X. Y. Zhang; K. W. Chen

    2009-08-01

    The multi-locus model-based clustering method Structure program was used to infer the genetic structure of nine indigenous Chinese chicken (Gallus gallus) populations based on 16 microsatellite markers. Twenty runs were carried out at each chosen value of predefined cluster numbers $(K)$ under admixture model. The Structure program properly inferred the presence of genetic structure with 0.999 probabilities. The genetic structure not only indicated that the nine kinds of chicken populations were defined actually by their locations, phenotypes or culture, but also reflected the underlying genetic variations. At $K = 2$, nine chicken populations were divided into two main clusters, one light-body type, including Chahua chicken (CHA), Tibet chicken (TIB), Xianju chicken (XIA), Gushi chicken (GUS) and Baier chicken (BAI); and the other heavy-body type, including Beijing You chicken (YOU), Xiaoshan chicken (XIA), Luyuan chicken (LUY) and Dagu chicken (DAG). GUS and DAG were divided into independent clusters respectively when equaled 4, 5, or 6. XIA and BIA chicken, XIA and LUY chicken, TIB and CHA chicken still clustered together when equaled 6, 7, and 8, respectively. These clustering results were consistent with the breeding directions of the nine chicken populations. The Structure program also identified migrants or admixed individuals. The admixed individuals were distributed in all the nine chicken populations, while migrants were only distributed in TIB, XIA and LUY populations. These results indicated that the clustering analysis using the Structure program might provide an accurate representation of the genetic relationship among the breeds.

  20. Assessing individual interethnic admixture and population substructure using a 48-insertion-deletion (INSEL) ancestry-informative marker (AIM) panel.

    Science.gov (United States)

    Santos, Ney P C; Ribeiro-Rodrigues, Elzemar M; Ribeiro-Dos-Santos, Andrea K C; Pereira, Rui; Gusmão, Leonor; Amorim, António; Guerreiro, Joáo F; Zago, Marco A; Matte, Cecília; Hutz, Mara H; Santos, Sidney E B

    2010-02-01

    Estimating the proportions of different ancestries in admixed populations is very important in population genetics studies, and it is particularly important for detecting population substructure effects in case-control association studies. In this work, a set of 48 ancestry-informative insertion-deletion polymorphisms (INDELs) were selected with the goal of efficiently measuring the proportions of three different ancestries (sub-Saharan African, European, and Native American) in mixed populations. All selected markers can be easily analyzed via multiplex PCR and detected with standard capillary electrophoresis. A total of 593 unrelated individuals representative of European, African, and Native American parental populations were typed, as were 380 individuals from three Brazilian populations with known admixture patterns. As expected, the interethnic admixture estimates show that individuals from southern Brazil present an almost exclusively European ancestry; Afro-descendant communities in the Amazon region, apart from the major African contribution, present some degree of admixture with Europeans and Native Americans; and a sample from Belém, in the northeastern Amazon, shows a significant contribution of the three ethnic groups, although with a greater European proportion. In summary, a panel of ancestry-informative INDELs was optimized and proven to be a valuable tool for estimating individual and global ancestry proportions in admixed populations. The ability to accurately infer interethnic admixtures highlights the usefulness of this marker set for assessing population substructure in association studies, particularly those conducted in Brazilian and other Latin American populations sharing trihybrid ancestry patterns.

  1. Mitochondrial DNA control region diversity in a population from Espirito Santo state, Brazil.

    Science.gov (United States)

    Sanches, Naiara M; Paneto, Greiciane G; Figueiredo, Raquel F; de Mello, Aline O; Cicarelli, Regina M B

    2014-10-01

    Mitochondrial DNA (mtDNA) analysis has proved to be useful for forensic identification, especially in cases which nuclear DNA markers fail, as in degraded samples or in cases where the biological material has few traces or no nuclear DNA. Moreover, it can be applied in population genetics, inferring the origin of a population. In this work, the entire mtDNA control region of 97 individuals from the state of Espirito Santo, Brazil, was analyzed. We have found 94 different haplotypes yielding a high haplotype diversity of 0.9994 ± 0.0016. The probability of a random match calculated was 1.09. Haplogroup distribution analysis confirmed a highly admixed Latin American population: African lineages (43.3 %), European lineages (32.0 %), Native American lineages (23.7 %) and Asian lineages (1.0 %). We have concluded that this type of tool can be used both in forensic genetics to the study of different human populations, such as highly admixed populations, and in the study of migration's history and colonization of different states and countries of the world.

  2. Highly discrepant proportions of female and male Scandinavian and British Isles ancestry within the isolated population of the Faroe Islands

    DEFF Research Database (Denmark)

    Als, Thomas D; Jorgensen, Tove H; Børglum, Anders D;

    2006-01-01

    a frequency-based admixture approach taking private haplotypes into account by the use of phylogenetic information. While previous studies have suggested an excess of Scandinavian ancestry among the male settlers of the Faroe Islands, the current study indicates an excess of British Isles ancestry among...... the female settlers of the Faroe Islands. Compared to other admixed populations of the North Atlantic region, the population of the Faroe Islands appears to have the highest level of asymmetry in Scandinavian vs British Isles ancestry proportions among female and male settlers of the archipelago....

  3. Dog ecology and population studies in Lagos State, Nigeria.

    Science.gov (United States)

    Hambolu, Sunday Emmanuel; Dzikwi, Asabe A; Kwaga, Jacob K P; Kazeem, Haruna M; Umoh, Jarlath U; Hambolu, Dupe A

    2014-02-14

    Dog population dynamics have a major impact upon the effectiveness of rabies control strategies. As such, understanding domestic dog ecology has been recognized as central to the design of effective rabies control programmes. This study was conducted to determine the dog ecology in Lagos State using compound dog count and street dog count in the three senatorial districts (Lagos West, East and Central) of Lagos State from February, 2011 to January, 2012. A total of 546 questionnaires were distributed for the compound dog count and all were completed and returned. Various aspects of dog ecology were determined, including size, sex, breed of the dog population, management of dogs and rabies awareness among the respondents. Out of the 546 compounds surveyed, 518 (94.87%) owned at least one dog. A total of 1,427 dogs were counted from the street counts while a total of 1,447 dogs (2.8 dogs/compound) were counted from the compound count. The dogs comprised of 583 males and 864 females, out of which 64.10% are confined. The dog vaccination coverage in the dog population surveyed was 64.10% and administered majorly (91.30%) by veterinarians. Security (60%) and pets (26%) were the major reasons for keeping dogs. Majority (88.80%) of the respondents were aware of rabies and its mode of transmission, but still believed in the use of concoctions (40.40%), herbs (19.90%) and consumption of the organ of the offending dog (11.50%) for the treatment of rabies. The findings of this study showed a male: female ratio of dog to be 1:1.5 and a dog: human ratio of 1:5.6. There was also a responsible dog ownership as majority of the respondents do confine, vaccinate and provide food for their dogs. Vaccination coverage of the total dog population was however below the 70-80% target recommended by the World Health Organization to achieve herd immunity.

  4. Fast and accurate inference of local ancestry in Latino populations

    Science.gov (United States)

    Baran, Yael; Pasaniuc, Bogdan; Sankararaman, Sriram; Torgerson, Dara G.; Gignoux, Christopher; Eng, Celeste; Rodriguez-Cintron, William; Chapela, Rocio; Ford, Jean G.; Avila, Pedro C.; Rodriguez-Santana, Jose; Burchard, Esteban Gonzàlez; Halperin, Eran

    2012-01-01

    Motivation: It is becoming increasingly evident that the analysis of genotype data from recently admixed populations is providing important insights into medical genetics and population history. Such analyses have been used to identify novel disease loci, to understand recombination rate variation and to detect recent selection events. The utility of such studies crucially depends on accurate and unbiased estimation of the ancestry at every genomic locus in recently admixed populations. Although various methods have been proposed and shown to be extremely accurate in two-way admixtures (e.g. African Americans), only a few approaches have been proposed and thoroughly benchmarked on multi-way admixtures (e.g. Latino populations of the Americas). Results: To address these challenges we introduce here methods for local ancestry inference which leverage the structure of linkage disequilibrium in the ancestral population (LAMP-LD), and incorporate the constraint of Mendelian segregation when inferring local ancestry in nuclear family trios (LAMP-HAP). Our algorithms uniquely combine hidden Markov models (HMMs) of haplotype diversity within a novel window-based framework to achieve superior accuracy as compared with published methods. Further, unlike previous methods, the structure of our HMM does not depend on the number of reference haplotypes but on a fixed constant, and it is thereby capable of utilizing large datasets while remaining highly efficient and robust to over-fitting. Through simulations and analysis of real data from 489 nuclear trio families from the mainland US, Puerto Rico and Mexico, we demonstrate that our methods achieve superior accuracy compared with published methods for local ancestry inference in Latinos. Availability: http://lamp.icsi.berkeley.edu/lamp/lampld/ Contact: bpasaniu@hsph.harvard.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:22495753

  5. 掺澎内传 PNC-803的防水混凝土在工程中的应用%On application of penetron admix PNC-803 waterproof concrete in projects

    Institute of Scientific and Technical Information of China (English)

    戴鲜英

    2015-01-01

    From the main features of materials,the paper illustrates the main features of penetron admix PNC-803,illustrates its waterproof mechanism,analyzes from the construction methods to economic effects according to engineering cases,and proves the waterproof effect and eco-nomic benefits have advantages,so as to extend its application in projects.%从材料的主要特性入手,阐述了澎内传PNC-803的主要特性,并进一步阐述了它的防水机理,然后附以工程实例,从施工方法到工程实体效果及经济效果进行了分析,证明在防水效果与经济效益方面确实有很大的优势,值得在工程项目中推广。

  6. EFFICIENCY OF PREPARED BAITS OF LONE OR/AND ADMIXED FOUR BOTANICAL OILS ON THE VIABILITY OF SUCCESSIVE RAISED GENERATIONS OF AGROTIS IPSILON (HUFNAGEL) (INSECTA: LEPIDOPTERA: NOCTUIDAE) AFTER TREATING THE PARENT ONES.

    Science.gov (United States)

    Mesbah, H A; El-Sayed, Nagda A; El-Kady, Magda B; Tayeb, E H; Mourad, A K; Kordy, A M; Henaidy, Zeinab M

    2014-01-01

    The present study is initiated to determine the toxic and delayed effects of four botanical oils on the greasy cutworm A. ipsilon, aiming to attain an alternative environmentally safe and effective phytochemicals against the insect-pest. Four botanical oils (camphor, red basil, menthol and rose oil) were added at rates of 0.5 and 1.0% (v/w). The tested oils were added alone, and/or admixed at proportional rate of 1:1 in the prepared baits against the exposed 4th instar till the 6th instar larvae of the insect. The study was run under the laboratory higrothermic conditions of 25±2°C and 65±5% R.H. The results showed that the tested baits of camphor, red basil and menthol oils at concentration rates of 0.5 and 1.0% (v/w) adversely affected the inspected parameters of fitness components of the treated individuals of parent (p) generation. They gave more or less fewer numbers of weak unviable adult-moths, which were either sterile or they laid few numbers of infertile eggs and died before the induction of (F1) progeny. That failure could be elucidated by the rapid occurrence of drastic effects on the biological performance of both the influenced sexes of adult-moths along the period of parent's development. Finally it ended by the inhibited induction of (F1) progeny. A delayed effect of the prepared baits of rose oil at 0.5 and 1.0% (v/w), was assessed on the following raised F1, F2, F3 and F4 generations after parent's treatment. The delayed effect was detected as less efficient latent effect on each of these consequently raised generations; characterized by the gradual decrease of the number of alive immatures and adult-moths. The effect was recorded as gradual increase of dead and malformed individuals and adult-moths. In addition to the gradual decrease of deposited and/or hatched eggs up to the 4th generation, which ended by the complete failure of the development. That failure could be also attributed to the cumulated effects of the induced recessive lethal

  7. Studies on dehydrogenation characteristic of Mg(NH{sub 2}){sub 2}/LiH mixture admixed with vanadium and vanadium based catalysts (V, V{sub 2}O{sub 5} and VCl{sub 3})

    Energy Technology Data Exchange (ETDEWEB)

    Shahi, Rohit R.; Yadav, T.P.; Shaz, M.A.; Srivastva, O.N. [Hydrogen Energy Centre, Department of Physics, Banaras Hindu University, Varanasi, Uttar Pradesh 221005 (India)

    2010-01-15

    In the present study, we have investigated the effect of vanadium and its compounds (V, V{sub 2}O{sub 5} and VCl{sub 3}) on desorption characteristics of 1:2 magnesium amide (Mg(NH{sub 2}){sub 2}) and lithium hydride (LiH) mixture. The hydrogen storage characteristics of 1:2 Mg(NH{sub 2}){sub 2}/LiH mixture gets enhanced with admixing of V, V{sub 2}O{sub 5} and VCl{sub 3} separately. The VCl{sub 3} has been found to be the most effective followed by V and V{sub 2}O{sub 5}. The activation energy for dehydrogenation process of 1:2 Mg(NH{sub 2}){sub 2}/LiH mixture with and without catalyst has been evaluated using a method suggested by Ozawa et al. Based on the experimental results, schematic reaction scheme for decomposition of Mg(NH{sub 2}){sub 2} in the presence of VCl{sub 3} has also been proposed. (author)

  8. Comparing genetic ancestry and self-reported race/ethnicity in a multiethnic population in New York City

    Indian Academy of Sciences (India)

    Yin Leng Lee; Susan Teitelbaum; Mary S. Wolff; James G. Wetmur; Jia Chen

    2010-12-01

    Self-reported race/ethnicity is frequently used in epidemiological studies to assess an individual’s background origin. However, in admixed populations such as Hispanic, self-reported race/ethnicity may not accurately represent them genetically because they are admixed with European, African and Native American ancestry. We estimated the proportions of genetic admixture in an ethnically diverse population of 396 mothers and 188 of their children with 35 ancestry informative markers (AIMs) using the STRUCTURE version 2.2 program. The majority of the markers showed significant deviation from Hardy–Weinberg equilibrium in our study population. In mothers self-identified as Black and White, the imputed ancestry proportions were 77.6% African and 75.1% European respectively, while the racial composition among self-identified Hispanics was 29.2% European, 26.0% African, and 44.8% Native American.We also investigated the utility of AIMs by showing the improved fitness of models in paraoxanase-1 genotype–phenotype associations after incorporating AIMs; however, the improvement was moderate at best. In summary, a minimal set of 35 AIMs is sufficient to detect population stratification and estimate the proportion of individual genetic admixture; however, the utility of these markers remains questionable.

  9. Comparing genetic ancestry and self-reported race/ethnicity in a multiethnic population in New York City.

    Science.gov (United States)

    Lee, Yin Leng; Teitelbaum, Susan; Wolff, Mary S; Wetmur, James G; Chen, Jia

    2010-12-01

    Self-reported race/ethnicity is frequently used in epidemiological studies to assess an individual's background origin. However, in admixed populations such as Hispanic, self-reported race/ethnicity may not accurately represent them genetically because they are admixed with European, African and Native American ancestry. We estimated the proportions of genetic admixture in an ethnically diverse population of 396 mothers and 188 of their children with 35 ancestry informative markers (AIMs) using the STRUCTURE version 2.2 program. The majority of the markers showed significant deviation from Hardy-Weinberg equilibrium in our study population. In mothers self-identified as Black and White, the imputed ancestry proportions were 77.6% African and 75.1% European respectively, while the racial composition among self-identified Hispanics was 29.2% European, 26.0% African, and 44.8% Native American. We also investigated the utility of AIMs by showing the improved fitness of models in paraoxanase-1 genotype-phenotype associations after incorporating AIMs; however, the improvement was moderate at best. In summary, a minimal set of 35 AIMs is sufficient to detect population stratification and estimate the proportion of individual genetic admixture; however, the utility of these markers remains questionable.

  10. Evaluation of a 49 InDel Marker HID panel in two specific populations of South America and one population of Northern Africa.

    Science.gov (United States)

    Moura-Neto, R S; Silva, R; Mello, I C; Nogueira, T; Al-Deib, A A; LaRue, B; King, J; Budowle, B

    2015-03-01

    The majority of STR loci are not ideal for the analysis of forensic samples with degraded and/or low template DNA. One alternative to overcome these limitations is the use of bi-allelic markers, which have low mutation rates and shorter amplicons. Human identification (HID) InDel marker panels have been described in several countries, including Brazil. The commercial kit available is, however, mostly suitable for Europeans, with lower discrimination power for other population groups. Recently, a combination of 49 InDel markers used in four different ethnic groups in the USA has been shown to be more informative than another panel from Portugal, already tested in a Rio de Janeiro sample. However, these 49 InDels have yet to be applied to other admixed or isolated populations. We assessed the efficiency of this panel in two urban admixed populations (Rio de Janeiro, Brazil; Tripoli, Libya) and one isolated Native Brazilian community. All markers are in Hardy-Weinberg equilibrium (HWE) after the Bonferroni correction, and no Linkage disequilibrium was detected. Assuming loci independence and no substructure effect, cumulative RMP was 2.7×10(-18), 1.5×10(-20), and 4.5×10(-20) for Native Brazilian, Rio de Janeiro, and Tripoli populations, respectively. The overall Fst value was 0.05512. Rio de Janeiro and Tripoli showed similar admixture levels, however for Native Brazilians one parental cluster represented over 60 % of the total parental population. We conclude that this panel is suitable for HID on these urban populations, but is less efficient for the isolated group.

  11. Possible effects of changes in CIL temperature and thickness on population dynamics of snow crab, Chionoecetes opilio, in the Gulf of Saint Lawrence

    National Research Council Canada - National Science Library

    Sainte-Marie, B; Gilbert, D

    1998-01-01

    The cold intermediate layer (CIL) of the Gulf of St. Lawrence is subject to interannual changes in core temperature and thickness, which are superimposed on persistent west-east and north-south gradients for these same variables...

  12. TIMP2 gene polymorphism as a potential tool to infer Brazilian population origin

    Directory of Open Access Journals (Sweden)

    da Silva RA

    2013-12-01

    Full Text Available Rodrigo Augusto da Silva,1 André Luis Shinohara,2 Denise Carleto Andia,1 Ariadne Letra,3 Regina Célia Peres,1 Ana Paula de Souza11Department of Morphology, Piracicaba Dental School, State University of Campinas, 2Oral Biology Program, Bauru Dental School, State University of São Paulo, São Paulo, Brazil; 3Department of Endodontics and Center for Craniofacial Research, School of Dentistry, University of Texas Health Science Center, Houston, TX, USAAbstract: Single nucleotide polymorphisms are genome variations that can be used as population-specific markers to infer genetic background and population origin. The Brazilian population is highly admixed due to immigration from several other populations. In particular, the state of São Paulo is recognized for the presence of Japanese individuals who seem likely to have contributed to a substantial proportion of ancestry in the modern Brazilian population. In the present study, we analyzed allele and genotype frequencies and associations of the –418G>C (rs8179090 single nucleotide polymorphism in the TIMP2 gene promoter in Brazilian and Japanese subjects, as well as in Japanese descendants from southeastern Brazil. The allele and genotype frequency analyses among groups demonstrated statistical significance (PC single nucleotide polymorphism of the TIMP2 gene, have a high probability of being Japanese or Japanese descendants. In addition to other genetic polymorphisms, the −418G>C TIMP2 polymorphism could be a population marker to assist in predicting Japanese ancestry, both in Japanese individuals and in admixed populations.Keywords: Brazilian, Japanese, polymorphism, allele, TIMP2

  13. Rangewide genetic analysis of Lesser Prairie-Chicken reveals population structure, range expansion, and possible introgression

    Science.gov (United States)

    Oyler-McCance, Sara J.; DeYoung, Randall W; Fike, Jennifer; Hagen, Christian A.; Johnson, Jeff A.; Larsson, Lena C; Patten, Michael

    2016-01-01

    The distribution of the Lesser Prairie-Chicken (Tympanuchus pallidicinctus) has been markedly reduced due to loss and fragmentation of habitat. Portions of the historical range, however, have been recolonized and even expanded due to planting of conservation reserve program (CRP) fields that provide favorable vegetation structure for Lesser Prairie-Chickens. The source population(s) feeding the range expansion is unknown, yet has resulted in overlap between Lesser and Greater Prairie-Chickens (T. cupido) increasing the potential for hybridization. Our objectives were to characterize connectivity and genetic diversity among populations, identify source population(s) of recent range expansion, and examine hybridization with the Greater Prairie-Chicken. We analyzed 640 samples from across the range using 13 microsatellites. We identified three to four populations corresponding largely to ecoregions. The Shinnery Oak Prairie and Sand Sagebrush Prairie represented genetically distinct populations (F ST > 0.034 and F ST > 0.023 respectively). The Shortgrass/CRP Mosaic and Mixed Grass ecoregions appeared admixed (F ST = 0.009). Genetic diversity was similar among ecoregions and N e ranged from 142 (95 % CI 99–236) for the Shortgrass/CRP Mosaic to 296 (95 % CI 233–396) in the Mixed Grass Prairie. No recent migration was detected among ecoregions, except asymmetric dispersal from both the Mixed Grass Prairie and to a lesser extent the Sand Sagebrush Prairie north into adjacent Shortgrass/CRP Mosaic (m = 0.207, 95 % CI 0.116–0.298, m = 0.097, 95 % CI 0.010–0.183, respectively). Indices investigating potential hybridization in the Shortgrass/CRP Mosaic revealed that six of the 13 individuals with hybrid phenotypes were significantly admixed suggesting hybridization. Continued monitoring of diversity within and among ecoregions is warranted as are actions promoting genetic connectivity and range expansion.

  14. Analysis of population substructure in two sympatric populations of Gran Chaco, Argentina.

    Science.gov (United States)

    Sevini, Federica; Yao, Daniele Yang; Lomartire, Laura; Barbieri, Annalaura; Vianello, Dario; Ferri, Gianmarco; Moretti, Edgardo; Dasso, Maria Cristina; Garagnani, Paolo; Pettener, Davide; Franceschi, Claudio; Luiselli, Donata; Franceschi, Zelda Alice

    2013-01-01

    Sub-population structure and intricate kinship dynamics might introduce biases in molecular anthropology studies and could invalidate the efforts to understand diseases in highly admixed populations. In order to clarify the previously observed distribution pattern and morbidity of Chagas disease in Gran Chaco, Argentina, we studied two populations (Wichí and Criollos) recruited following an innovative bio-cultural model considering their complex cultural interactions. By reconstructing the genetic background and the structure of these two culturally different populations, the pattern of admixture, the correspondence between genealogical and genetic relationships, this integrated perspective had the power to validate data and to link the gap usually relying on a singular discipline. Although Wichí and Criollos share the same area, these sympatric populations are differentiated from the genetic point of view as revealed by Non Recombinant Y Chromosome genotyping resulting in significantly high Fst values and in a lower genetic variability in the Wichí population. Surprisingly, the Amerindian and the European components emerged with comparable amounts (20%) among Criollos and Wichí respectively. The detailed analysis of mitochondrial DNA showed that the two populations have as much as 87% of private haplotypes. Moreover, from the maternal perspective, despite a common Amerindian origin, an Andean and an Amazonian component emerged in Criollos and in Wichí respectively. Our approach allowed us to highlight that quite frequently there is a discrepancy between self-reported and genetic kinship. Indeed, if self-reported identity and kinship are usually utilized in population genetics as a reliable proxy for genetic identity and parental relationship, in our model populations appear to be the result not only and not simply of the genetic background but also of complex cultural determinants. This integrated approach paves the way to a rigorous reconstruction of

  15. Highly efficient synthesis of dimethyl ether from syngas over the admixed catalyst of CuO-ZnO-Al{sub 2}O{sub 3} and antimony oxide modified HZSM-5 zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Dongsen Mao; Guanzhong Lu [Research Institute of Applied Catalysis, Department of Chemical Engineering, Shanghai Institute of Technology, Shanghai 200235 (China); Jianchao Xia; Bin Zhang [Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208 (China)

    2010-06-15

    A series of HZSM-5 zeolites modified with various contents of antimony oxide (0-30 wt.%) were prepared by solid state ion reaction at 500 C, and the acidities of the resulted materials were characterized by temperature-programmed desorption of NH{sub 3}. The direct synthesis of dimethyl ether (DME) from syngas was carried out over the admixed catalysts of an industrial CuO-ZnO-Al{sub 2}O{sub 3} methanol synthesis catalyst and the parent and antimony oxide modified HZSM-5 zeolites under pressurized fixed-bed continuous flow conditions. The results indicated that modification of HZSM-5 with suitable amount of antimony oxide significantly decreased the selectivity for undesired byproducts like hydrocarbons and carbon dioxide from 9.3% and 32.4% to less than 1% and 28%, respectively, so the selectivity for DME was enhanced greatly from 55% to 69% under temperature of 260 C, pressure of 4 MPa and gas hourly space velocity of 1500 mL h{sup -1} g{sub cat}{sup -1}. The decrease in the formation of hydrocarbons and carbon dioxide can be attributed to the significant decline in the amount of strong acid sites of the HZSM-5 zeolite induced by antimony oxide modification. Additionally, the influences of the operating parameters on the performance of the most efficient catalyst were also investigated. The results showed that high reaction temperature and high gas hourly space velocity resulted in both lower carbon monoxide conversion and lower dimethyl ether selectivity, so they should be no higher than 280 C and 3000 mL h{sup -1} g{sub cat}{sup -1}, respectively. (author)

  16. Highly efficient synthesis of dimethyl ether from syngas over the admixed catalyst of CuO-ZnO-Al{sub 2}O{sub 3} and antimony oxide modified HZSM-5 zeolite

    Energy Technology Data Exchange (ETDEWEB)

    Mao Dongsen, E-mail: dsmao1106@yahoo.com.c [Research Institute of Applied Catalysis, Department of Chemical Engineering, Shanghai Institute of Technology, Shanghai 200235 (China); Xia Jianchao; Zhang Bin [Shanghai Research Institute of Petrochemical Technology, SINOPEC, Shanghai 201208 (China); Lu Guanzhong [Research Institute of Applied Catalysis, Department of Chemical Engineering, Shanghai Institute of Technology, Shanghai 200235 (China)

    2010-06-15

    A series of HZSM-5 zeolites modified with various contents of antimony oxide (0-30 wt.%) were prepared by solid state ion reaction at 500 deg. C, and the acidities of the resulted materials were characterized by temperature-programmed desorption of NH{sub 3}. The direct synthesis of dimethyl ether (DME) from syngas was carried out over the admixed catalysts of an industrial CuO-ZnO-Al{sub 2}O{sub 3} methanol synthesis catalyst and the parent and antimony oxide modified HZSM-5 zeolites under pressurized fixed-bed continuous flow conditions. The results indicated that modification of HZSM-5 with suitable amount of antimony oxide significantly decreased the selectivity for undesired byproducts like hydrocarbons and carbon dioxide from 9.3% and 32.4% to less than 1% and 28%, respectively, so the selectivity for DME was enhanced greatly from 55% to 69% under temperature of 260 deg. C, pressure of 4 MPa and gas hourly space velocity of 1500 mL h{sup -1} g{sub cat}{sup -1}. The decrease in the formation of hydrocarbons and carbon dioxide can be attributed to the significant decline in the amount of strong acid sites of the HZSM-5 zeolite induced by antimony oxide modification. Additionally, the influences of the operating parameters on the performance of the most efficient catalyst were also investigated. The results showed that high reaction temperature and high gas hourly space velocity resulted in both lower carbon monoxide conversion and lower dimethyl ether selectivity, so they should be no higher than 280 deg. C and 3000 mL h{sup -1} g{sub cat}{sup -1}, respectively.

  17. Patterns of cis regulatory variation in diverse human populations.

    Directory of Open Access Journals (Sweden)

    Barbara E Stranger

    Full Text Available The genetic basis of gene expression variation has long been studied with the aim to understand the landscape of regulatory variants, but also more recently to assist in the interpretation and elucidation of disease signals. To date, many studies have looked in specific tissues and population-based samples, but there has been limited assessment of the degree of inter-population variability in regulatory variation. We analyzed genome-wide gene expression in lymphoblastoid cell lines from a total of 726 individuals from 8 global populations from the HapMap3 project and correlated gene expression levels with HapMap3 SNPs located in cis to the genes. We describe the influence of ancestry on gene expression levels within and between these diverse human populations and uncover a non-negligible impact on global patterns of gene expression. We further dissect the specific functional pathways differentiated between populations. We also identify 5,691 expression quantitative trait loci (eQTLs after controlling for both non-genetic factors and population admixture and observe that half of the cis-eQTLs are replicated in one or more of the populations. We highlight patterns of eQTL-sharing between populations, which are partially determined by population genetic relatedness, and discover significant sharing of eQTL effects between Asians, European-admixed, and African subpopulations. Specifically, we observe that both the effect size and the direction of effect for eQTLs are highly conserved across populations. We observe an increasing proximity of eQTLs toward the transcription start site as sharing of eQTLs among populations increases, highlighting that variants close to TSS have stronger effects and therefore are more likely to be detected across a wider panel of populations. Together these results offer a unique picture and resource of the degree of differentiation among human populations in functional regulatory variation and provide an estimate for

  18. Patterns of cis regulatory variation in diverse human populations.

    Directory of Open Access Journals (Sweden)

    Barbara E Stranger

    Full Text Available The genetic basis of gene expression variation has long been studied with the aim to understand the landscape of regulatory variants, but also more recently to assist in the interpretation and elucidation of disease signals. To date, many studies have looked in specific tissues and population-based samples, but there has been limited assessment of the degree of inter-population variability in regulatory variation. We analyzed genome-wide gene expression in lymphoblastoid cell lines from a total of 726 individuals from 8 global populations from the HapMap3 project and correlated gene expression levels with HapMap3 SNPs located in cis to the genes. We describe the influence of ancestry on gene expression levels within and between these diverse human populations and uncover a non-negligible impact on global patterns of gene expression. We further dissect the specific functional pathways differentiated between populations. We also identify 5,691 expression quantitative trait loci (eQTLs after controlling for both non-genetic factors and population admixture and observe that half of the cis-eQTLs are replicated in one or more of the populations. We highlight patterns of eQTL-sharing between populations, which are partially determined by population genetic relatedness, and discover significant sharing of eQTL effects between Asians, European-admixed, and African subpopulations. Specifically, we observe that both the effect size and the direction of effect for eQTLs are highly conserved across populations. We observe an increasing proximity of eQTLs toward the transcription start site as sharing of eQTLs among populations increases, highlighting that variants close to TSS have stronger effects and therefore are more likely to be detected across a wider panel of populations. Together these results offer a unique picture and resource of the degree of differentiation among human populations in functional regulatory variation and provide an estimate for

  19. An Extensive Analysis of Y-Chromosomal Microsatellite Haplotypes in Globally Dispersed Human Populations

    Science.gov (United States)

    Kayser, Manfred; Krawczak, Michael; Excoffier, Laurent; Dieltjes, Patrick; Corach, Daniel; Pascali, Vincente; Gehrig, Christian; Bernini, Luigi F.; Jespersen, Jørgen; Bakker, Egbert; Roewer, Lutz; de Knijff, Peter

    2001-01-01

    The genetic variance at seven Y-chromosomal microsatellite loci (or short tandem repeats [STRs]) was studied among 986 male individuals from 20 globally dispersed human populations. A total of 598 different haplotypes were observed, of which 437 (73.1%) were each found in a single male only. Population-specific haplotype-diversity values were .86–.99. Analyses of haplotype diversity and population-specific haplotypes revealed marked population-structure differences between more-isolated indigenous populations (e.g., Central African Pygmies or Greenland Inuit) and more-admixed populations (e.g., Europeans or Surinamese). Furthermore, male individuals from isolated indigenous populations shared haplotypes mainly with male individuals from their own population. By analysis of molecular variance, we found that 76.8% of the total genetic variance present among these male individuals could be attributed to genetic differences between male individuals who were members of the same population. Haplotype sharing between populations, ΦST statistics, and phylogenetic analysis identified close genetic affinities among European populations and among New Guinean populations. Our data illustrate that Y-chromosomal STR haplotypes are an ideal tool for the study of the genetic affinities between groups of male subjects and for detection of population structure. PMID:11254455

  20. The genetic structure of Leishmania infantum populations in Brazil and its possible association with the transmission cycle of visceral leishmaniasis.

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    Gabriel Eduardo Melim Ferreira

    Full Text Available Leishmania infantum is the etiologic agent of visceral leishmaniasis (VL in the Americas, Mediterranean basin and West and Central Asia. Although the geographic structure of L. infantum populations from the Old World have been described, few studies have addressed the population structure of this parasite in the Neotropical region. We employed 14 microsatellites to analyze the population structure of the L. infantum strains isolated from humans and dogs from most of the Brazilian states endemic for VL and from Paraguay. The results indicate a low genetic diversity, high inbreeding estimates and a depletion of heterozygotes, which together indicate a predominantly clonal breeding system, but signs of sexual events are also present. Three populations were identified from the clustering analysis, and they were well supported by F statistics inferences and partially corroborated by distance-based. POP1 (111 strains was observed in all but one endemic area. POP2 (31 strains is also well-dispersed, but it was the predominant population in Mato Grosso (MT. POP3 (31 strains was less dispersed, and it was observed primarily in Mato Grosso do Sul (MS. Strains originated from an outbreak of canine VL in Southern Brazil were grouped in POP1 with those from Paraguay, which corroborates the hypothesis of dispersal from Northeastern Argentina and Paraguay. The distribution of VL in MS seems to follow the west-east construction of the Bolivia-Brazil pipeline from Corumbá municipality. This may have resulted in a strong association of POP3 and Lutzomyia cruzi, which is the main VL vector in Corumbá, and a dispersion of this population in this region that was shaped by human interference. This vector also occurs in MT and may influence the structure of POP2. This paper presents significant advances in the understanding of the population structure of L. infantum in Brazil and its association with eco-epidemiological aspects of VL.

  1. Explaining spatial heterogeneity in population dynamics and genetics from spatial variation in resources for a large herbivore.

    Science.gov (United States)

    Contasti, Adrienne L; Tissier, Emily J; Johnstone, Jill F; McLoughlin, Philip D

    2012-01-01

    Fine-scale spatial variation in genetic relatedness and inbreeding occur across continuous distributions of several populations of vertebrates; however, the basis of observed variation is often left untested. Here we test the hypothesis that prior observations of spatial patterns in genetics for an island population of feral horses (Sable Island, Canada) were the result of spatial variation in population dynamics, itself based in spatial heterogeneity in underlying habitat quality. In order to assess how genetic and population structuring related to habitat, we used hierarchical cluster analysis of water sources and an indicator analysis of the availability of important forage species to identify a longitudinal gradient in habitat quality along the length of Sable Island. We quantify a west-east gradient in access to fresh water and availability of two important food species to horses: sandwort, Honckenya peploides, and beach pea, Lathyrus japonicas. Accordingly, the population clusters into three groups that occupy different island segments (west, central, and east) that vary markedly in their local dynamics. Density, body condition, and survival and reproduction of adult females were highest in the west, followed by central and east areas. These results mirror a previous analysis of genetics, which showed that inbreeding levels are highest in the west (with outbreeding in the east), and that there are significant differences in fixation indices among groups of horses along the length of Sable Island. Our results suggest that inbreeding depression is not an important limiting factor to the horse population. We conclude that where habitat gradients exist, we can anticipate fine-scale heterogeneity in population dynamics and hence genetics.

  2. Inversion polymorphism in some natural populations of Drosophila pseudoobscura from central Mexico

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    Salceda Víctor M.

    2007-01-01

    Full Text Available Samples of D. pseudoobscura were taken in seventeen localities in Central Mexico inside the parallels 18o - 20o N, with the purpose of determine the chromosomal polymorphism in the third of the different populations of this species. From each captured female a single larva of its offspring was taken, its salivary glands extracted and stained with a solution of aceto orcein to observe the polytene chromosomes. From these smears the corresponding karyotype of each larva was determined, keeping a record of them. With the information gathered the relative frequency of each one of the fourteen different inversions found was calculated. A grand total of 1894 third chromosomes were analyzed. The fourteen different inversions found are equivalent to a 34.1 % of the total chromosomal variation of the species. The most abundant inversions found were: TL 50.6 %, CU 27.2 5, SC 9.1 % and EP 5.5 %; the remaining ten inversions detected are in general grounds rare ones with variable relative frequencies depending on the locality. Analysis of the predominant inversions for each population was done. The presence of West-East gradients is reported, even if in cases not so well defined, since as one moves in a particular direction the ups and downs in relative frequency for the alternating pairs TL-CU; TL-SC in the western populations and TL-CU in the eastern ones were observed. The assignment of each population to a particular race was also done, and such a way we were able to recognize three different races coexisting in the area of study.

  3. Admix Compatibility in Carbon Black Loaded Toners

    Institute of Scientific and Technical Information of China (English)

    Paul C. Julien

    2004-01-01

    In a xerographic system where the charge on the toner is controlled by the electrical nature of the carbon black used as a pigment, it is found that the speed with which added toner is charged to the proper level depends on the relative electrical negativity of the carbon black in the original and added toner. This is due to the fact that the incumbent toner typically shares its charge with the new toner through charge exchange among the conductive carbon black particles. If the carbon blacks are electrically dissimilar, this charge sharing may fail.Thus, a toner may work well by itself in a machine, but the same toner may fail when added to a machine already running with a toner from a different vendor or even a different lot of toner from the same vendor. Thus the electrical nature of the carbon black needs to be controlled. This can be done by controlling the oxidation of the carbon black.

  4. Reconstructing Austronesian population history in Island Southeast Asia.

    Science.gov (United States)

    Lipson, Mark; Loh, Po-Ru; Patterson, Nick; Moorjani, Priya; Ko, Ying-Chin; Stoneking, Mark; Berger, Bonnie; Reich, David

    2014-08-19

    Austronesian languages are spread across half the globe, from Easter Island to Madagascar. Evidence from linguistics and archaeology indicates that the 'Austronesian expansion,' which began 4,000-5,000 years ago, likely had roots in Taiwan, but the ancestry of present-day Austronesian-speaking populations remains controversial. Here, we analyse genome-wide data from 56 populations using new methods for tracing ancestral gene flow, focusing primarily on Island Southeast Asia. We show that all sampled Austronesian groups harbour ancestry that is more closely related to aboriginal Taiwanese than to any present-day mainland population. Surprisingly, western Island Southeast Asian populations have also inherited ancestry from a source nested within the variation of present-day populations speaking Austro-Asiatic languages, which have historically been nearly exclusive to the mainland. Thus, either there was once a substantial Austro-Asiatic presence in Island Southeast Asia, or Austronesian speakers migrated to and through the mainland, admixing there before continuing to western Indonesia.

  5. Gender differences in ancestral contribution and admixture in Venezuelan populations.

    Science.gov (United States)

    Guerra, D Castro De; Pérez, C Figuera; Izaguirre, M H; Barahona, E Arroyo; Larralde, A Rodríguez; Lugo, M Vívenes De

    2011-06-01

    The origin of the contribution of uniparental heritage were analyzed in 615 samples of individuals proceeding from 13 towns classified according to historic differences in their emergence and development as African-derived, European-derived, and admixed/urban. Mitochondrial and Y-chromosome haplogroups were identified by PCR-restriction fragment length polymorphism. The results were compared with previous estimates of admixture made with autosomal markers and with historic aspects. The results show a predominantly indigenous genetic contribution through the female, being more prevalent in urban populations; the African contribution, although dispersed, presents a larger concentration in the African-derived towns, whereas the European contribution is limited to populations with this origin, reflecting isolation and the conservation of the distribution pattern of genes of the Colonial era. With regard to admixture through males, it is almost exclusively of European origin, whereas the African contribution is basically concentrated in the African-derived towns, and the Amerindian lineages are almost nonexistent. The genome of paternal heredity, as opposed to the autosomal and the mitochondrial, shows a homogeneous pattern of admixture that is independent of the origin of the population studied, suggesting that European genes have been introduced into the Venezuelan population through male immigrations, whereas the indigenous contribution has been preserved in the Venezuelan genetic pool through the women. These results provide evidence of the heterogeneity in the genetic origin of the Venezuelan population, which should be taken into account in forensic and epidemiologic genetic studies.

  6. Evaluating the X chromosome-specific diversity of Colombian populations using insertion/deletion polymorphisms.

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    Adriana Ibarra

    Full Text Available The European and African contribution to the pre-existing Native American background has influenced the complex genetic pool of Colombia. Because colonisation was not homogeneous in this country, current populations are, therefore, expected to have different proportions of Native American, European and African ancestral contributions. The aim of this work was to examine 11 urban admixed populations and a Native American group, called Pastos, for 32 X chromosome indel markers to expand the current knowledge concerning the genetic background of Colombia. The results revealed a highly diverse genetic background comprising all admixed populations, harbouring important X chromosome contributions from all continental source populations. In addition, Colombia is genetically sub-structured, with different proportions of European and African influxes depending on the regions. The samples from the North Pacific and Caribbean coasts have a high African ancestry, showing the highest levels of diversity. The sample from the South Andean region showed the lowest diversity and significantly higher proportion of Native American ancestry than the other samples from the North Pacific and Caribbean coasts, Central-West and Central-East Andean regions, and the Orinoquian region. The results of admixture analysis using X-chromosomal markers suggest that the high proportion of African ancestry in the North Pacific coast was primarily male driven. These men have joined to females with higher Native American and European ancestry (likely resulting from a classic colonial asymmetric mating type: European male x Amerindian female. This high proportion of male-mediated African contributions is atypical of colonial settings, suggesting that the admixture occurred during a period when African people were no longer enslaved. In the remaining regions, the African contribution was primarily female-mediated, whereas the European counterpart was primarily male driven and the

  7. Frequency of CCR5delta32 in Brazilian populations

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    A.E. Vargas

    2006-03-01

    Full Text Available A sample of 103 randomly chosen healthy individuals from Alegrete, RS, Brazil, was tested for the CCR5delta32 allele, which is known to influence susceptibility to HIV-1 infection. The CCR5delta32 allele was identified by PCR amplification using specific primers flanking the region of deletion, followed by electrophoresis on a 3% agarose gel. The data obtained were compared to those reported for other populations and interpreted in terms of Brazilian history. The individuals studied came from a highly admixed population. Most of them were identified as white (N = 59, while blacks and browns (mulattoes were N = 13 and N = 31, respectively. The observed frequencies, considering the white, black and brown samples (6.8, 3.8, and 6.4%, respectively, suggest an important European parental contribution, even in populations identified as black and brown. However, in Brazil as a whole, this allele shows gradients indicating a relatively good correlation with the classification based on skin color and other physical traits, used here to define major Brazilian population groups.

  8. Application of Dry Air Drying Techniques on West-East Gas Pipeline Project

    Institute of Scientific and Technical Information of China (English)

    GaoJianguo; XieLigong; DaiZongyu

    2004-01-01

    Based on the pre-eommissioning requirements of gas pipeline, the basic principles and influential factors of dry air drying adopted in long distance gas pipelines, and states in detail the technological flow and the equipment required, etc. are introduced, which will have practical significance in drying operation on gas pipeline.

  9. Genetic structure and hierarchical population divergence history of Acer mono var. mono in South and Northeast China.

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    Chunping Liu

    Full Text Available Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE, whereas it has a scattered and patchy distribution in South China (SC. In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM. Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species' evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (FST  = 0.073; G'ST  = 0.278 among all populations, but significantly higher in the SC group than the NE group, mirroring the species' more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study.

  10. Genetic structure and hierarchical population divergence history of Acer mono var. mono in South and Northeast China.

    Science.gov (United States)

    Liu, Chunping; Tsuda, Yoshiaki; Shen, Hailong; Hu, Lijiang; Saito, Yoko; Ide, Yuji

    2014-01-01

    Knowledge of the genetic structure and evolutionary history of tree species across their ranges is essential for the development of effective conservation and forest management strategies. Acer mono var. mono, an economically and ecologically important maple species, is extensively distributed in Northeast China (NE), whereas it has a scattered and patchy distribution in South China (SC). In this study, the genetic structure and demographic history of 56 natural populations of A. mono var. mono were evaluated using seven nuclear microsatellite markers. Neighbor-joining tree and STRUCTURE analysis clearly separated populations into NE and SC groups with two admixed-like populations. Allelic richness significantly decreased with increasing latitude within the NE group while both allelic richness and expected heterozygosity showed significant positive correlation with latitude within the SC group. Especially in the NE region, previous studies in Quercus mongolica and Fraxinus mandshurica have also detected reductions in genetic diversity with increases in latitude, suggesting this pattern may be common for tree species in this region, probably due to expansion from single refugium following the last glacial maximum (LGM). Approximate Bayesian Computation-based analysis revealed two major features of hierarchical population divergence in the species' evolutionary history. Recent divergence between the NE group and the admixed-like group corresponded to the LGM period and ancient divergence of SC groups took place during mid-late Pleistocene period. The level of genetic differentiation was moderate (FST  = 0.073; G'ST  = 0.278) among all populations, but significantly higher in the SC group than the NE group, mirroring the species' more scattered distribution in SC. Conservation measures for this species are proposed, taking into account the genetic structure and past demographic history identified in this study.

  11. Assessment of IrisPlex-based multiplex for eye and skin color prediction with application to a Portuguese population.

    Science.gov (United States)

    Dario, Paulo; Mouriño, Helena; Oliveira, Ana Rita; Lucas, Isabel; Ribeiro, Teresa; Porto, Maria João; Costa Santos, Jorge; Dias, Deodália; Corte Real, Francisco

    2015-11-01

    DNA phenotyping research is one of the most emergent areas of forensic genetics. Predictions of externally visible characteristics are possible through analysis of single nucleotide polymorphisms. These tools can provide police with "intelligence" in cases where there are no obvious suspects and unknown biological samples found at the crime scene do not result in any criminal DNA database hits. IrisPlex, an eye color prediction assay, revealed high prediction rates for blue and brown eye color in European populations. However, this is less predictive in some non-European populations, probably due to admixing. When compared to other European countries, Portugal has a relatively admixed population, resulting from a genetic influx derived from its proximity to and historical relations with numerous African territories. The aim of this work was to evaluate the utility of IrisPlex in the Portuguese population. Furthermore, the possibility of supplementing this multiplex with additional markers to also achieve skin color prediction within this population was evaluated. For that, IrisPlex was augmented with additional SNP loci. Eye and skin color prediction was estimated using the multinomial logistic regression and binomial logistic regression models, respectively. The results demonstrated eye color prediction accuracies of the IrisPlex system of 90 and 60% for brown and blue eye color, respectively, and 77% for intermediate eye color, after allele frequency adjustment. With regard to skin color, it was possible to achieve a prediction accuracy of 93%. In the future, phenotypic determination multiplexes must include additional loci to permit skin color prediction as presented in this study as this can be an advantageous tool for forensic investigation.

  12. Population structure and dispersal routes of an invasive parasite, Fascioloides magna, in North America and Europe.

    Science.gov (United States)

    Juhásová, Ludmila; Králová-Hromadová, Ivica; Bazsalovicsová, Eva; Minárik, Gabriel; Štefka, Jan; Mikulíček, Peter; Pálková, Lenka; Pybus, Margo

    2016-10-13

    Fascioloides magna (Trematoda: Fasciolidae) is an important liver parasite of a wide range of free-living and domestic ruminants; it represents a remarkable species due to its large spatial distribution, invasive character, and potential to colonize new territories. The present study provides patterns of population genetic structure and admixture in F. magna across all enzootic regions in North America and natural foci in Europe, and infers migratory routes of the parasite on both continents. In total, 432 individuals from five North American enzootic regions and three European foci were analysed by 11 microsatellite loci. Genetic data were evaluated by several statistical approaches: (i) the population genetic structure of F. magna was inferred using program STRUCTURE; (ii) the genetic interrelationships between populations were analysed by PRINCIPAL COORDINATES ANALYSIS; and (iii) historical dispersal routes in North America and recent invasion routes in Europe were explored using MIGRATE. The analysis of dispersal routes of the parasite in North America revealed west-east and south-north lineages that partially overlapped in the central part of the continent, where different host populations historically met. The exact origin of European populations of F. magna and their potential translocation routes were determined. Flukes from the first European focus, Italy, were related to F. magna from northern Pacific coast, while parasites from the Czech focus originated from south-eastern USA, particularly South Carolina. The Danube floodplain forests (third and still expanding focus) did not display relationship with any North American population; instead the Czech origin of the Danube population was indicated. A serial dilution of genetic diversity along the dispersion route across central and eastern Europe was observed. The results of microsatellite analyses were compared to previously acquired outputs from mitochondrial haplotype data and correlated with past human

  13. Male-specific contributions to the Brazilian population of Espirito Santo.

    Science.gov (United States)

    de F Figueiredo, Raquel; Ambrosio, Isabela B; Braganholi, Danilo F; Chemale, Gustavo; Martins, Joyce A; Gomes, Veronica; Gusmão, Leonor; Cicarelli, Regina M B

    2016-05-01

    Y chromosome markers have been widely studied due to their various applications in the fields of forensic and evolutionary genetics. In this study, 35 Y-SNPs and 17 Y-STRs were genotyped in 253 males from the State of Espirito Santo, Brazil. A total of 18 haplogroups and 243 haplotypes were detected; the haplogroup and haplotype diversities were 0.7794 and 0.9997, respectively. Genetic distance analysis using the Y-STR data showed no statistically significant differences between Espirito Santo and other admixed populations from Brazil. The classification of paternal lineages based on haplogroups showed a predominant European contribution (85.88%), followed by African (11.37%) and Amerindian (2.75%) contributions.

  14. The Genomic Signature of Population Reconnection Following Isolation: From Theory to HIV

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    Nicolas Alcala

    2016-01-01

    Full Text Available Ease of worldwide travel provides increased opportunities for organisms not only to colonize new environments but also to encounter related but diverged populations. Such events of reconnection and secondary contact of previously isolated populations are widely observed at different time scales. For example, during the quaternary glaciation, sea water level fluctuations caused temporal isolation of populations, often to be followed by secondary contact. At shorter time scales, population isolation and reconnection of viruses are commonly observed, and such events are often associated with epidemics and pandemics. Here, using coalescent theory and simulations, we describe the temporal impact of population reconnection after isolation on nucleotide differences and the site frequency spectrum, as well as common summary statistics of DNA variation. We identify robust genomic signatures of population reconnection after isolation. We utilize our development to infer the recent evolutionary history of human immunodeficiency virus 1 (HIV-1 in Asia and South America, successfully retrieving the successive HIV subtype colonization events in these regions. Our analysis reveals that divergent HIV-1 subtype populations are currently admixing in these regions, suggesting that HIV-1 may be undergoing a process of homogenization, contrary to popular belief.

  15. Genetic evidence of tiger population structure and migration within an isolated and fragmented landscape in Northwest India.

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    Patlolla Anuradha Reddy

    Full Text Available BACKGROUND: Majority of the tiger habitat in Indian subcontinent lies within high human density landscapes and is highly sensitive to surrounding pressures. These forests are unable to sustain healthy tiger populations within a tiger-hostile matrix, despite considerable conservation efforts. Ranthambore Tiger Reserve (RTR in Northwest India is one such isolated forest which is rapidly losing its links with other tiger territories in the Central Indian landscape. Non-invasive genetic sampling for individual identification is a potent technique to understand the relationships between threatened tiger populations in degraded habitats. This study is an attempt to establish tiger movement across a fragmented landscape between RTR and its neighboring forests, Kuno-Palpur Wildlife Sanctuary (KPWLS and Madhav National Park (MNP based on non-invasively obtained genetic data. METHODS: Data from twelve microsatellite loci was used to define population structure and also to identify first generation migrants and admixed individuals in the above forests. RESULTS: Population structure was consistent with the Central Indian landscape and we could determine significant gene flow between RTR and MNP. We could identify individuals of admixed ancestry in both these forests, as well as first generation migrants from RTR to KPWLS and MNP. CONCLUSIONS: Our results indicate reproductive mixing between animals of RTR and MNP in the recent past and migration of animals even today, despite fragmentation and poaching risk, from RTR towards MNP. Substantial conservation efforts should be made to maintain connectivity between these two subpopulations and also higher protection status should be conferred on Madhav National Park.

  16. Influence of ethnicity on the distribution of genetic polymorphisms associated with risk of chronic liver disease in South American populations.

    Science.gov (United States)

    Pontoriero, Ana Cecilia; Trinks, Julieta; Hulaniuk, María Laura; Caputo, Mariela; Fortuny, Lisandro; Pratx, Leandro Burgos; Frías, Analía; Torres, Oscar; Nuñez, Félix; Gadano, Adrián; Argibay, Pablo; Corach, Daniel; Flichman, Diego

    2015-07-29

    The global burden of chronic liver disease is rising. Besides environmental, behavioral, viral and metabolic factors, genetic polymorphisms in patatin-like phospholipase-3 (PNPLA3) and vitamin D receptor (VDR) genes have been related to the development of chronic liver disease and progression towards liver cancer. Although their prevalence differs remarkably among ethnic groups, the frequency of these polymorphisms in South American populations -whose genetic background is highly admixed- has been poorly studied. Hence, the aim of this study was to characterize polymorphisms related to chronic liver disease and their association with the genetic ancestry of South American populations. DNA samples from 258 healthy unrelated male volunteers were analyzed. The frequencies of G and C alleles of rs738409 polymorphism (PNPLA3 gene) were 74 % and 26 %, respectively; whereas the bAt (CCA) haplotype (VDR gene) was observed in 32.5 % of the samples. The GG genotype of PNPLA3 rs738409 and the bAt (CCA) haplotype -associated with an increased risk of chronic liver disease and progression towards liver cancer- were significantly more frequent among samples exhibiting maternal and paternal Native American haplogroups (63.7 % and 64.6 %), intermediate among admixed samples (45.1 % and 44.9 %; p = 0.03) and the lowest for Non-native American ancestry (30.1 % and 29.6 %; p = 0.001 and p = 0.0008). These results suggest that individuals with Native American ancestry might have a high risk of chronic liver disorders and cancer. Furthermore, these data not only support the molecular evaluation of ancestry in multi-ethnic population studies, but also suggest that the characterization of these variants in South American populations may be useful for establishing public health policies aimed at high risk ethnic communities.

  17. A reduced number of mtSNPs saturates mitochondrial DNA haplotype diversity of worldwide population groups.

    Science.gov (United States)

    Salas, Antonio; Amigo, Jorge

    2010-05-03

    The high levels of variation characterising the mitochondrial DNA (mtDNA) molecule are due ultimately to its high average mutation rate; moreover, mtDNA variation is deeply structured in different populations and ethnic groups. There is growing interest in selecting a reduced number of mtDNA single nucleotide polymorphisms (mtSNPs) that account for the maximum level of discrimination power in a given population. Applications of the selected mtSNP panel range from anthropologic and medical studies to forensic genetic casework. This study proposes a new simulation-based method that explores the ability of different mtSNP panels to yield the maximum levels of discrimination power. The method explores subsets of mtSNPs of different sizes randomly chosen from a preselected panel of mtSNPs based on frequency. More than 2,000 complete genomes representing three main continental human population groups (Africa, Europe, and Asia) and two admixed populations ("African-Americans" and "Hispanics") were collected from GenBank and the literature, and were used as training sets. Haplotype diversity was measured for each combination of mtSNP and compared with existing mtSNP panels available in the literature. The data indicates that only a reduced number of mtSNPs ranging from six to 22 are needed to account for 95% of the maximum haplotype diversity of a given population sample. However, only a small proportion of the best mtSNPs are shared between populations, indicating that there is not a perfect set of "universal" mtSNPs suitable for all population contexts. The discrimination power provided by these mtSNPs is much higher than the power of the mtSNP panels proposed in the literature to date. Some mtSNP combinations also yield high diversity values in admixed populations. The proposed computational approach for exploring combinations of mtSNPs that optimise the discrimination power of a given set of mtSNPs is more efficient than previous empirical approaches. In contrast to

  18. Forensic efficiency parameters of the Investigator Argus X-12 kit in women from two Mestizo and seven Amerindian populations from Mexico.

    Science.gov (United States)

    Cortés-Trujillo, I; Ramos-González, B; Salas-Salas, O; Zuñiga-Chiquette, F; Zetina Hernández, A; Martínez-Cortés, G; Ruiz-Hernández, M; González-Martín, A; Ferragut, J F; Rangel-Villalobos, H

    2017-05-01

    Allele frequency distribution and statistical parameters of forensic efficiency concerning the Investigator Argus X-12 kit (Qiagen, Hilden, Germany) were determined in a total sample of 641 unrelated Mexican females, including two Mestizo-admixed- populations (n=309) and seven Amerindian groups (n=332) from the main regions of the country. Most of the 12 X-STRs were in agreement with Hardy-Weinberg expectations in all nine Mexican populations. The power of discrimination in females (PD) and Median exclusion chance for trios (MECT) and duos (MECD) of this genetic system based on X-STRs were >99.99%. Although Mexican populations showed significant pairwise differentiation, a closer relationship was evident between Amerindian groups and nearby Mestizos, in agreement with historical records, previous genetic studies, and X-linked inheritance pattern expectations. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Ancient DNA reveals a migration of the ancient Di-qiang populations into Xinjiang as early as the early Bronze Age.

    Science.gov (United States)

    Gao, Shi-Zhu; Zhang, Ye; Wei, Dong; Li, Hong-Jie; Zhao, Yong-Bin; Cui, Yin-Qiu; Zhou, Hui

    2015-05-01

    Xinjiang is at the crossroads between East and West Eurasia, and it harbors a relatively complex genetic history. In order to better understand the population movements and interactions in this region, mitochondrial and Y chromosome analyses on 40 ancient human remains from the Tianshanbeilu site in eastern Xinjiang were performed. Twenty-nine samples were successfully assigned to specific mtDNA haplogroups, including the west Eurasian maternal lineages of U and W and the east Eurasian maternal lineages of A, C, D, F, G, Z, M7, and M10. In the male samples, two Y chromosome haplogroups, C* and N1 (xN1a, N1c), were successfully assigned. Our mitochondrial and Y-chromosomal DNA analyses combined with the archaeological studies revealed that the Di-qiang populations from the Hexi Corridor had migrated to eastern Xinjiang and admixed with the Eurasian steppe populations in the early Bronze Age.

  20. Leveraging population admixture to explain missing heritability of complex traits

    Science.gov (United States)

    Zaitlen, Noah; Pasaniuc, Bogdan; Sankararaman, Sriram; Bhatia, Gaurav; Zhang, Jianqi; Gusev, Alexander; Young, Taylor; Tandon, Arti; Pollack, Samuela; Vilhjálmsson, Bjarni J.; Assimes, Themistocles L.; Berndt, Sonja I.; Blot, William J.; Chanock, Stephen; Franceschini, Nora; Goodman, Phyllis G.; He, Jing; Hennis, Anselm JM; Hsing, Ann; Ingles, Sue A.; Isaacs, William; Kittles, Rick A.; Klein, Eric A.; Lange, Leslie A.; Nemesure, Barbara; Patterson, Nick; Reich, David; Rybicki, Benjamin A.; Stanford, Janet L.; Stevens, Victoria L; Strom, Sara S.; Whitsel, Eric A; Witte, John S.; Xu, Jianfeng; Haiman, Christopher; Wilson, James G.; Kooperberg, Charles; Stram, Daniel; Reiner, Alex P.; Tang, Hua; Price, Alkes L.

    2014-01-01

    Despite recent progress on estimating the heritability explained by genotyped SNPs (hg2), a large gap between hg2 and estimates of total narrow-sense heritability (h2) remains. Explanations for this gap include rare variants, or upward bias in family-based estimates of h2 due to shared environment or epistasis. We estimate h2 from unrelated individuals in admixed populations by first estimating the heritability explained by local ancestry (hγ2). We show that hγ2 = 2FSTCθ(1−θ)h2, where FSTC measures frequency differences between populations at causal loci and θ is the genome-wide ancestry proportion. Our approach is not susceptible to biases caused by epistasis or shared environment. We examined 21,497 African Americans from three cohorts, analyzing 13 phenotypes. For height and BMI, we obtained h2 estimates of 0.55 ± 0.09 and 0.23 ± 0.06, respectively, which are larger than estimates of hg2 in these and other data, but smaller than family-based estimates of h2. PMID:25383972

  1. Population Structure Analysis of Bull Genomes of European and Western Ancestry

    Science.gov (United States)

    Chung, Neo Christopher; Szyda, Joanna; Frąszczak, Magdalena; Fries, Hans Rudolf; SandøLund, Mogens; Guldbrandtsen, Bernt; Boichard, Didier; Stothard, Paul; Veerkamp, Roel; Goddard, Michael; Van Tassell, Curtis P.; Hayes, Ben

    2017-01-01

    Since domestication, population bottlenecks, breed formation, and selective breeding have radically shaped the genealogy and genetics of Bos taurus. In turn, characterization of population structure among diverse bull (males of Bos taurus) genomes enables detailed assessment of genetic resources and origins. By analyzing 432 unrelated bull genomes from 13 breeds and 16 countries, we demonstrate genetic diversity and structural complexity among the European/Western cattle population. Importantly, we relaxed a strong assumption of discrete or admixed population, by adapting latent variable models for individual-specific allele frequencies that directly capture a wide range of complex structure from genome-wide genotypes. As measured by magnitude of differentiation, selection pressure on SNPs within genes is substantially greater than that on intergenic regions. Additionally, broad regions of chromosome 6 harboring largest genetic differentiation suggest positive selection underlying population structure. We carried out gene set analysis using SNP annotations to identify enriched functional categories such as energy-related processes and multiple development stages. Our population structure analysis of bull genomes can support genetic management strategies that capture structural complexity and promote sustainable genetic breadth. PMID:28084449

  2. Mexican mestizo population sub-structure: effects on genetic and forensic statistical parameters.

    Science.gov (United States)

    Noris, Gino; Santana, Carla; Meraz-Ríos, Marco Antonio; de Lourdes Munoz, María; Majluf-Cruz, Abraham; Magaña, Jonathan J; Granados, Julio; Quezada, Rosa; Revilla, María Cristina; Martínez-Salas, Sergio; Xihuitl, Salvador; Martínez de la Escalera, Gonzalo; Díaz-Badillo, Alvaro; Calderon-Aranda, Emma S; Gómez, Rocío

    2012-12-01

    Since Mexican mestizos are an admixed population, it is necessary to determine the effects that the substructure of the population has on genetic and forensic parameters. With this aim, a study was performed with 15 STR loci (CODIS plus D2S1338 and D19S433) on 1,640 unrelated Mexican mestizos. We determine allele and genotypic frequencies observing departure from Hardy-Weinberg expectation (12 out of 15 loci, with an excess of homozygotes, Fis > 0), as well as pairs of loci in an apparent linkage disequilibrium (13 of 92 loci). We conducted a test for genetic population stratification, the results show that the Mexican mestizo population is substructured into three subgroups, which are in HW and linkage equilibrium. The combination of the 15 loci in the whole population has high forensic efficiency with the capacity to genetically discriminate one individual in one quintillion (1/10(18)). Our data potentially validates the use of these 15 STR loci to establish forensic identity and parentage testing for legal purposes, and offers a powerful tool for genetic variation analysis. However, given that the population is stratified, we highly recommend applying a correction with the inbreeding coefficient in calculations of paternity and forensic studies to avoid erroneous assumptions.

  3. Genetic population structure analysis in New Hampshire reveals Eastern European ancestry.

    Science.gov (United States)

    Sloan, Chantel D; Andrew, Angeline D; Duell, Eric J; Williams, Scott M; Karagas, Margaret R; Moore, Jason H

    2009-09-07

    Genetic structure due to ancestry has been well documented among many divergent human populations. However, the ability to associate ancestry with genetic substructure without using supervised clustering has not been explored in more presumably homogeneous and admixed US populations. The goal of this study was to determine if genetic structure could be detected in a United States population from a single state where the individuals have mixed European ancestry. Using Bayesian clustering with a set of 960 single nucleotide polymorphisms (SNPs) we found evidence of population stratification in 864 individuals from New Hampshire that can be used to differentiate the population into six distinct genetic subgroups. We then correlated self-reported ancestry of the individuals with the Bayesian clustering results. Finnish and Russian/Polish/Lithuanian ancestries were most notably found to be associated with genetic substructure. The ancestral results were further explained and substantiated using New Hampshire census data from 1870 to 1930 when the largest waves of European immigrants came to the area. We also discerned distinct patterns of linkage disequilibrium (LD) between the genetic groups in the growth hormone receptor gene (GHR). To our knowledge, this is the first time such an investigation has uncovered a strong link between genetic structure and ancestry in what would otherwise be considered a homogenous US population.

  4. Population Genomics of sub-saharan Drosophila melanogaster: African diversity and non-African admixture.

    Directory of Open Access Journals (Sweden)

    John E Pool

    Full Text Available Drosophila melanogaster has played a pivotal role in the development of modern population genetics. However, many basic questions regarding the demographic and adaptive history of this species remain unresolved. We report the genome sequencing of 139 wild-derived strains of D. melanogaster, representing 22 population samples from the sub-Saharan ancestral range of this species, along with one European population. Most genomes were sequenced above 25X depth from haploid embryos. Results indicated a pervasive influence of non-African admixture in many African populations, motivating the development and application of a novel admixture detection method. Admixture proportions varied among populations, with greater admixture in urban locations. Admixture levels also varied across the genome, with localized peaks and valleys suggestive of a non-neutral introgression process. Genomes from the same location differed starkly in ancestry, suggesting that isolation mechanisms may exist within African populations. After removing putatively admixed genomic segments, the greatest genetic diversity was observed in southern Africa (e.g. Zambia, while diversity in other populations was largely consistent with a geographic expansion from this potentially ancestral region. The European population showed different levels of diversity reduction on each chromosome arm, and some African populations displayed chromosome arm-specific diversity reductions. Inversions in the European sample were associated with strong elevations in diversity across chromosome arms. Genomic scans were conducted to identify loci that may represent targets of positive selection within an African population, between African populations, and between European and African populations. A disproportionate number of candidate selective sweep regions were located near genes with varied roles in gene regulation. Outliers for Europe-Africa F(ST were found to be enriched in genomic regions of locally

  5. Counting Populations

    Science.gov (United States)

    Damonte, Kathleen

    2004-01-01

    Scientists use sampling to get an estimate of things they cannot easily count. A population is made up of all the organisms of one species living together in one place at the same time. All of the people living together in one town are considered a population. All of the grasshoppers living in a field are a population. Scientists keep track of the…

  6. Calculating expected DNA remnants from ancient founding events in human population genetics

    Directory of Open Access Journals (Sweden)

    Stacey Andrew

    2008-10-01

    Full Text Available Abstract Background Recent advancements in sequencing and computational technologies have led to rapid generation and analysis of high quality genetic data. Such genetic data have achieved wide acceptance in studies of historic human population origins and admixture. However, in studies relating to small, recent admixture events, genetic factors such as historic population sizes, genetic drift, and mutation can have pronounced effects on data reliability and utility. To address these issues we conducted genetic simulations targeting influential genetic parameters in admixed populations. Results We performed a series of simulations, adjusting variable values to assess the affect of these genetic parameters on current human population studies and what these studies infer about past population structure. Final mean allele frequencies varied from 0.0005 to over 0.50, depending on the parameters. Conclusion The results of the simulations illustrate that, while genetic data may be sensitive and powerful in large genetic studies, caution must be used when applying genetic information to small, recent admixture events. For some parameter sets, genetic data will not be adequate to detect historic admixture. In such cases, studies should consider anthropologic, archeological, and linguistic data where possible.

  7. The genetic diversity of three peculiar populations descending from the slave trade: Gm study of Noir Marron from French Guiana.

    Science.gov (United States)

    Brucato, Nicolas; Tortevoye, Patricia; Plancoulaine, Sabine; Guitard, Evelyne; Sanchez-Mazas, Alicia; Larrouy, Georges; Gessain, Antoine; Dugoujon, Jean-Michel

    2009-10-01

    The Noir Marron communities are the direct descendants of African slaves brought to the Guianas during the four centuries (16th to 19th) of the Atlantic slave trade. Among them, three major ethnic groups have been studied: the Aluku, the Ndjuka and the Saramaka. Their history led them to share close relationships with Europeans and Amerindians, as largely documented in their cultural records. The study of Gm polymorphisms of immunoglobulins may help to estimate the amount of gene flow linked to these cultural exchanges. Surprisingly, very low levels of European contribution (2.6%) and Amerindian contribution (1.7%) are detected in the Noir Marron gene pool. On the other hand, an African contribution of 95.7% redraws their origin to West Africa (F(ST) < or = 0.15). This highly preserved African gene pool of the Noir Marron is unique in comparison to other African American populations of Latin America, who are notably more admixed.

  8. A Rare Case of Waldenström Macroglobulinemia/Lymphoplasmacytic Lymphoma with Light Chain Discrepancy between B Lymphocyte Population and Serum Paraprotein.

    Science.gov (United States)

    Kim, Hyun Jeong; Hur, Mina; Kim, Hanah; Moon, Hee-Won; Yun, Yeo-Min; Kim, Sung Yong; Lee, Mark Hong

    2015-01-01

    Waldenström macroglobulinemia (WM) is a subset of lymphoplasmacytic lymphoma with bone marrow involvement, monotypic immunoglobulin (Ig) M and a light chain of neoplastic cells. A 68-year-old woman presented with fever, nausea, vomiting, and pancytopenia. Her serum albumin/globulin ratio was reversed, and monoclonal gammopathy of IgM, lambda type (23.20%, 1.58 g/dL) was detected. In her bone marrow, increased small lymphocytes were admixed with plasmacytoid lymphocytes and plasma cells. She was diagnosed as having lymphoplasmacytic variant of WM. Immunohistochemical stains and flow cytometic analysis revealed two distinct populations; monoclonal B cells (kappa+) and abnormal plasma cells (CD19-/CD56+/lambda+). She expired 19 days after admission due to septic shock. This is a rare case of WM exhibiting a light chain discrepancy between monoclonal B lymphocytes and paraprotein-secreting plasma cells. Light chain restriction may occur distinctly between lymphocyte and plasma cell populations in WM.

  9. Promoting Population

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    THE world's population reached 5 billion in 1987,then 6 billion in 1999;now,in 2011,it is 7 billion.For a country with a set birth control policy,the way in which Chinese people and the media view this number has greatly changed.People are increasingly reflecting on the concept of population from a more scientific and rational perspective.This shift is a change from how people perceived population in the past.

  10. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  11. Population Blocks.

    Science.gov (United States)

    Smith, Martin H.

    1992-01-01

    Describes an educational game called "Population Blocks" that is designed to illustrate the concept of exponential growth of the human population and some potential effects of overpopulation. The game material consists of wooden blocks; 18 blocks are painted green (representing land), 7 are painted blue (representing water); and the remaining…

  12. Extreme heterogeneity in parasitism despite low population genetic structure among monarch butterflies inhabiting the Hawaiian Islands.

    Science.gov (United States)

    Pierce, Amanda A; de Roode, Jacobus C; Altizer, Sonia; Bartel, Rebecca A

    2014-01-01

    Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4-85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here.

  13. Extreme Heterogeneity in Parasitism Despite Low Population Genetic Structure among Monarch Butterflies Inhabiting the Hawaiian Islands

    Science.gov (United States)

    Pierce, Amanda A.; de Roode, Jacobus C.; Altizer, Sonia; Bartel, Rebecca A.

    2014-01-01

    Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus) are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4–85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here. PMID:24926796

  14. Extreme heterogeneity in parasitism despite low population genetic structure among monarch butterflies inhabiting the Hawaiian Islands.

    Directory of Open Access Journals (Sweden)

    Amanda A Pierce

    Full Text Available Host movement and spatial structure can strongly influence the ecology and evolution of infectious diseases, with limited host movement potentially leading to high spatial heterogeneity in infection. Monarch butterflies (Danaus plexippus are best known for undertaking a spectacular long-distance migration in eastern North America; however, they also form non-migratory populations that breed year-round in milder climates such as Hawaii and other tropical locations. Prior work showed an inverse relationship between monarch migratory propensity and the prevalence of the protozoan parasite, Ophryocystis elektroscirrha. Here, we sampled monarchs from replicate sites within each of four Hawaiian Islands to ask whether these populations show consistently high prevalence of the protozoan parasite as seen for monarchs from several other non-migratory populations. Counter to our predictions, we observed striking spatial heterogeneity in parasite prevalence, with infection rates per site ranging from 4-85%. We next used microsatellite markers to ask whether the observed variation in infection might be explained by limited host movement and spatial sub-structuring among sites. Our results showed that monarchs across the Hawaiian Islands form one admixed population, supporting high gene flow among sites. Moreover, measures of individual-level genetic diversity did not predict host infection status, as might be expected if more inbred hosts harbored higher parasite loads. These results suggest that other factors such as landscape-level environmental variation or colonization-extinction processes might instead cause the extreme heterogeneity in monarch butterfly infection observed here.

  15. A Comparative Analysis of Genetic Ancestry and Admixture in the Colombian Populations of Chocó and Medellín.

    Science.gov (United States)

    Conley, Andrew B; Rishishwar, Lavanya; Norris, Emily T; Valderrama-Aguirre, Augusto; Mariño-Ramírez, Leonardo; Medina-Rivas, Miguel A; Jordan, I King

    2017-09-06

    At least twenty percent of Colombians identify as having African ancestry, yielding the second largest population of Afro-descendants in Latin America. To date, there have been relatively few studies focused on the genetic ancestry of Afro-Latino populations. We report a comparative analysis of the genetic ancestry of Chocó, a state located on Colombia's Pacific coast with a population that is >80% Afro-Colombian. We compared genome-wide patterns of genetic ancestry and admixture for Chocó to six other admixed American populations, with an emphasis on a Mestizo population from the nearby Colombian city of Medellín. One hundred sample donors from Chocó were genotyped across 610,545 genomic sites and compared to 94 publicly available whole genome sequences from Medellín. At the continental level, Chocó shows mostly African genetic ancestry (76%) with a nearly even split between European (13%) and Native American (11%) fractions, whereas Medellín has primarily European ancestry (75%), followed by Native American (18%) and African (7%). Sample donors from Chocó self-identify as having more African ancestry, and conversely less European and Native American ancestry, than can be genetically inferred, as opposed to what we previously found for Medellín, where individuals tend to over-estimate levels of European ancestry. We developed a novel approach for subcontinental ancestry assignment, which allowed us to characterize subcontinental source populations for each of the three distinct continental ancestry fractions separately. Despite the clear differences between Chocó and Medellín at the level of continental ancestry, the two populations show overall patterns of subcontinental ancestry that are highly similar. Their African subcontinental ancestries are only slightly different, with Chocó showing more exclusive shared ancestry with the modern Yoruba (Nigerian) population and Medellín having relatively more shared ancestry with West African populations in

  16. Imaginary populations

    Directory of Open Access Journals (Sweden)

    A. Martínez–Abraín

    2010-01-01

    Full Text Available A few years ago, Camus & Lima (2002 wrote an essay to stimulate ecologists to think about how we define and use a fundamental concept in ecology: the population. They concluded, concurring with Berryman (2002, that a population is "a group of individuals of the same species that live together in an area of sufficient size to permit normal dispersal and/or migration behaviour and in which population changes are largely the results of birth and death processes". They pointed out that ecologists often forget "to acknowledge that many study units are neither natural nor even units in terms of constituting a population system", and hence claimed that we "require much more accuracy than in past decades in order to be more effective to characterize populations and predict their behaviour". They stated that this is especially necessary "in disciplines such as conservation biology or resource pest management, to avoid reaching wrong conclusions or making inappropriate decisions". As a population ecologist and conservation biologist I totally agree with these authors and, like them, I be¬lieve that greater precision and care is needed in the use and definition of ecological terms. The point I wish to stress here is that we ecologists tend to forget that when we use statistical tools to infer results from our sample to a population we work with what statisticians term "imaginary", "hypothetical" or "potential" popula¬tions. As Zar (1999 states, if our sample data consist of 40 measurements of growth rate in guinea pigs "the population about which conclusions might be drawn is the growth rates of all the guinea pigs that conceivably might have been administered the same food supplement under identical conditions". Such a population does not really exist, and hence it is considered a hypothetical or imaginary population. Compare that definition with the population concept that would be in our minds when performing such measurements. We would probably

  17. Population policy.

    Science.gov (United States)

    1987-03-01

    Participants in the Seminar on Population Policies for Top-level Policy Makers and Program Managers, meeting in Thailand during January 1987, examined the challenges now facing them regarding the implementation of fertility regulation programs in their respective countries -- Bangladesh, China, India, Indonesia, Malaysia, Nepal, Pakistan, the Philippines, the Republic of Korea, and Thailand. This Seminar was organized to coincide with the completion of an Economic and Social Commission for Asia and the Pacific (ESCAP) study investigating the impact and efficiency of family planning programs in the region. Country studies were reviewed at the Seminar along with policy issues about the status of women, incentive and disincentive programs, and socioeconomic factors affecting fertility. In Bangladesh the government recognizes population growth as its top priority problem related to the socioeconomic development of the country and is working to promote a reorientation strategy from the previous clinic-oriented to a multidimensional family welfare program. China's family planning program seeks to postpone marraige, space the births of children between 3-5 years, and promote the 1-child family. Its goal is to reduce the rate of natural increase from 12/1000 in 1978 to 5/1000 by 1985 and 0 by 2000. India's 7th Five-Year-Plan (1986-90) calls for establishing a 2-child family norm by 2000. In Indonesia the government's population policy includes reducing the rate of population growth, achieving a redistribution of the population, adjusting economic factors, and creating prosperous families. The government of Indonesia reversed its policy to reduce the population growth rate in 1984 and announced its goal of achieving a population of 70 million by 2100 in order to support mass consumption industries. It has created an income tax deduction system favoring large families and maternity benefits for women who have up to 5 children as incentives. Nepal's official policy is to

  18. Evaluation of InnoTyper® 21 in a sample of Rio de Janeiro population as an alternative forensic panel.

    Science.gov (United States)

    Moura-Neto, R S; Mello, I C T; Silva, R; Maette, A P C; Bottino, C G; Woerner, A; King, J; Wendt, F; Budowle, B

    2017-07-26

    The use of bi-allelic markers such as retrotransposable element insertion polymorphisms or Innuls (for insertion/null) can overcome some limitations of short tandem repeat (STR) loci in typing forensic biological evidence. This study investigated the efficiency of the InnoTyper® 21 Innul markers in an urban admixed population sample in Rio de Janeiro (n = 40) and one highly compromised sample collected as evidence by the Rio de Janeiro police. No significant departures from Hardy-Weinberg equilibrium were detected after the Bonferroni correction (α' ≈ 0.05/20, p < 0.0025), and no significant linkage disequilibrium was observed between markers. Assuming loci independence, the cumulative random match probability (RMP) was 2.3 × 10(-8). A lower mean Fis value was obtained for this sample population compared with those of three North American populations (African-American, Southwest Hispanic, US Caucasian). Principal component analysis with the three North American populations and one from 21 East Asian population showed that African Americans segregated as an independent group while US Caucasian, Southwest Hispanic, East Asian, and Rio de Janeiro populations are in a single large heterogeneous group. Also, a full Innuls profile was produced from an evidence sample, despite the DNA being highly degraded. In conclusion, this system is a useful complement to standard STR kits.

  19. Population connectivity: dam migration mitigations and contemporary site fidelity in arctic char

    Directory of Open Access Journals (Sweden)

    Heggenes Jan

    2011-07-01

    Full Text Available Abstract Background Animal feeding and spawning migrations may be limited by physical barriers and behavioral interactions. Dam constructions (e.g. hydropower commonly include gateways for fish migrations to sustain ecological connectivity. Relative genetic impacts of fish passage devices versus natural processes (e.g. hybrid inferiority are, however, rarely studied. We examined genetic (i.e. microsatellite population connectivity of highly migrating lake-dwelling Arctic char (Salvelinus alpinus, introduced 20 generations ago, across and within two subalpine lakes separated by a dam with a subterranean tunnel and spill gates after 7 generations. Due to water flow regime, the time window for fish migration is highly restricted. Results Char populations, with similar genetic structuring and diversity observed across and within lakes, were admixed across the dam with fishways during feeding. For spawning, however, statistically significant, but very low population differentiation (θ; 0.002 - 0.013 was found in nine out of ten reproductive site comparisons, reflecting interactions between extensive migration (mean first generation (F0 = 10.8% and initial site fidelity. Simulations indicated that genetic drift among relatively small effective populations (mean Ne = 62 may have caused the observed contemporary differentiation. Novel Bayesian analyses indicated mean contributions of 71% F0 population hybrids in spawning populations, of which 76% had maternal or paternal native origin. Conclusions Ecological connectivity between lakes separated by a dam has been retained through construction of fishways for feeding migration. Considerable survival and homing to ancestral spawning sites in hybrid progeny was documented. Population differentiation despite preceding admixture is likely caused by contemporary reduced reproductive fitness of population hybrids. The study documents the beginning stages of population divergence among spatial aggregations with

  20. A genomic portrait of haplotype diversity and signatures of selection in indigenous southern African populations.

    Directory of Open Access Journals (Sweden)

    Emile R Chimusa

    2015-03-01

    Full Text Available We report a study of genome-wide, dense SNP (∼ 900K and copy number polymorphism data of indigenous southern Africans. We demonstrate the genetic contribution to southern and eastern African populations, which involved admixture between indigenous San, Niger-Congo-speaking and populations of Eurasian ancestry. This finding illustrates the need to account for stratification in genome-wide association studies, and that admixture mapping would likely be a successful approach in these populations. We developed a strategy to detect the signature of selection prior to and following putative admixture events. Several genomic regions show an unusual excess of Niger-Kordofanian, and unusual deficiency of both San and Eurasian ancestry, which were considered the footprints of selection after population admixture. Several SNPs with strong allele frequency differences were observed predominantly between the admixed indigenous southern African populations, and their ancestral Eurasian populations. Interestingly, many candidate genes, which were identified within the genomic regions showing signals for selection, were associated with southern African-specific high-risk, mostly communicable diseases, such as malaria, influenza, tuberculosis, and human immunodeficiency virus/AIDs. This observation suggests a potentially important role that these genes might have played in adapting to the environment. Additionally, our analyses of haplotype structure, linkage disequilibrium, recombination, copy number variation and genome-wide admixture highlight, and support the unique position of San relative to both African and non-African populations. This study contributes to a better understanding of population ancestry and selection in south-eastern African populations; and the data and results obtained will support research into the genetic contributions to infectious as well as non-communicable diseases in the region.

  1. SHIPS: Spectral Hierarchical clustering for the Inference of Population Structure in genetic studies.

    Science.gov (United States)

    Bouaziz, Matthieu; Paccard, Caroline; Guedj, Mickael; Ambroise, Christophe

    2012-01-01

    Inferring the structure of populations has many applications for genetic research. In addition to providing information for evolutionary studies, it can be used to account for the bias induced by population stratification in association studies. To this end, many algorithms have been proposed to cluster individuals into genetically homogeneous sub-populations. The parametric algorithms, such as Structure, are very popular but their underlying complexity and their high computational cost led to the development of faster parametric alternatives such as Admixture. Alternatives to these methods are the non-parametric approaches. Among this category, AWclust has proven efficient but fails to properly identify population structure for complex datasets. We present in this article a new clustering algorithm called Spectral Hierarchical clustering for the Inference of Population Structure (SHIPS), based on a divisive hierarchical clustering strategy, allowing a progressive investigation of population structure. This method takes genetic data as input to cluster individuals into homogeneous sub-populations and with the use of the gap statistic estimates the optimal number of such sub-populations. SHIPS was applied to a set of simulated discrete and admixed datasets and to real SNP datasets, that are data from the HapMap and Pan-Asian SNP consortium. The programs Structure, Admixture, AWclust and PCAclust were also investigated in a comparison study. SHIPS and the parametric approach Structure were the most accurate when applied to simulated datasets both in terms of individual assignments and estimation of the correct number of clusters. The analysis of the results on the real datasets highlighted that the clusterings of SHIPS were the more consistent with the population labels or those produced by the Admixture program. The performances of SHIPS when applied to SNP data, along with its relatively low computational cost and its ease of use make this method a promising

  2. Genetic affinities of the central Indian tribal populations.

    Directory of Open Access Journals (Sweden)

    Gunjan Sharma

    Full Text Available BACKGROUND: The central Indian state Madhya Pradesh is often called as 'heart of India' and has always been an important region functioning as a trinexus belt for three major language families (Indo-European, Dravidian and Austroasiatic. There are less detailed genetic studies on the populations inhabited in this region. Therefore, this study is an attempt for extensive characterization of genetic ancestries of three tribal populations, namely; Bharia, Bhil and Sahariya, inhabiting this region using haploid and diploid DNA markers. METHODOLOGY/PRINCIPAL FINDINGS: Mitochondrial DNA analysis showed high diversity, including some of the older sublineages of M haplogroup and prominent R lineages in all the three tribes. Y-chromosomal biallelic markers revealed high frequency of Austroasiatic-specific M95-O2a haplogroup in Bharia and Sahariya, M82-H1a in Bhil and M17-R1a in Bhil and Sahariya. The results obtained by haploid as well as diploid genetic markers revealed strong genetic affinity of Bharia (a Dravidian speaking tribe with the Austroasiatic (Munda group. The gene flow from Austroasiatic group is further confirmed by their Y-STRs haplotype sharing analysis, where we determined their founder haplotype from the North Munda speaking tribe, while, autosomal analysis was largely in concordant with the haploid DNA results. CONCLUSIONS/SIGNIFICANCE: Bhil exhibited largely Indo-European specific ancestry, while Sahariya and Bharia showed admixed genetic package of Indo-European and Austroasiatic populations. Hence, in a landscape like India, linguistic label doesn't unequivocally follow the genetic footprints.

  3. [Population education].

    Science.gov (United States)

    Niang, M

    1992-12-01

    Africa has the highest population growth rate in the world (3%). It has 650 million people (about 900 million in 2000). Rapid population growth has serious consequences which, if not addressed, will be disastrous. This worrisome situation has led some governments to adopt demographic policies to slow down population growth. The UN Economic, Scientific and Cultural Organization (UNESCO) recommends that schools provide population education. Various population conferences have popularized population education in schools among African countries. UNESCO began its regional program on population education in Africa in 1969. National family life and population education (FL/PE) projects have increased from 4 in 1970 to 32 in 1990 (17 in French- and Portuguese-speaking Africa and 5 in English-speaking Africa). These projects teach students about the links between demographic problems and socioeconomic factors and contemporary culture. They aim for total development of the individual and improvement of the quality of life for the individual, family, and community. Topics covered in FL/PE are birth rate; fertility; health; and maternal, infant, and child mortality; unwanted pregnancy; illegal abortion; sexually transmitted diseases; rural-urban migration; and urbanization. Benin introduced FL/PE at all levels of its education system while Senegal, Guinea, Mauritania, and Zaire introduced it to only the primary and secondary school levels. Some countries teach FL/PE as one discipline while most countries (e.g., Senegal) have integrated it into other disciplines (e.g., geography). FL/PE should begin in primary schools because they have the most students and prepare students for middle schools, which provide FL/PE. Elementary education in Senegal is being overhauled to introduce current major problems bit by bit. Senegal also wants to incorporate FL/PE into literacy and adult education programs. Integration of FL/PE into other disciplines should be encouraged.

  4. Ancestry informative marker sets for determining continental origin and admixture proportions in common populations in America.

    Science.gov (United States)

    Kosoy, Roman; Nassir, Rami; Tian, Chao; White, Phoebe A; Butler, Lesley M; Silva, Gabriel; Kittles, Rick; Alarcon-Riquelme, Marta E; Gregersen, Peter K; Belmont, John W; De La Vega, Francisco M; Seldin, Michael F

    2009-01-01

    To provide a resource for assessing continental ancestry in a wide variety of genetic studies, we identified, validated, and characterized a set of 128 ancestry informative markers (AIMs). The markers were chosen for informativeness, genome-wide distribution, and genotype reproducibility on two platforms (TaqMan assays and Illumina arrays). We analyzed genotyping data from 825 subjects with diverse ancestry, including European, East Asian, Amerindian, African, South Asian, Mexican, and Puerto Rican. A comprehensive set of 128 AIMs and subsets as small as 24 AIMs are shown to be useful tools for ascertaining the origin of subjects from particular continents, and to correct for population stratification in admixed population sample sets. Our findings provide general guidelines for the application of specific AIM subsets as a resource for wide application. We conclude that investigators can use TaqMan assays for the selected AIMs as a simple and cost efficient tool to control for differences in continental ancestry when conducting association studies in ethnically diverse populations.

  5. Hypodontia: prevalence and pattern amongst the living Druze population - a Near Eastern genetic isolate.

    Science.gov (United States)

    Alsoleihat, Firas; Khraisat, Ameen

    2014-06-01

    The Druze population is a small-sized Near Eastern genetic isolate with high rates of consanguineous marriages. The present study aimed at investigating prevalence, pattern and distribution of hypodontia in the permanent dentition, excluding wisdom teeth, amongst this population. Panoramic radiographs, dental casts, and anamnestic records of 85 un-admixed Druze schoolchildren (45 males, 40 females; age range=14-18 years, mean age=16 years, SD=0.5 years) were examined for evidence of hypodontia. Those with any type of facial clefts or craniofacial syndromes were excluded. Hypodontia prevalence was 11.8% (11.1% for males, 12.5% for females) with no statistically significant difference between sexes. The average number of missing teeth per child was 1.4 (1.2 for males, 1.6 for females). The majority (90%) of affected individuals exhibited minor hypodontia (one or two teeth missing). The most commonly missing teeth were upper lateral incisors and canines, followed by lower and upper second premolars. Asymmetrical hypodontia was more prevalent. Maxillary, left side, and anterior segment predominance were observed. The distinct features of hypodontia among the Druze population are the relatively high prevalence of minor hypodontia, and the upper lateral incisors and canines being the most commonly missing teeth.

  6. Population Structure, Diversity and Reproductive Mode of the Grape Phylloxera (Daktulosphaira vitifoliae) across Its Native Range

    Science.gov (United States)

    Walker, M. Andrew

    2017-01-01

    Grape Phylloxera, Daktulosphaira vitifoliae, is a gall-forming insect that feeds on the leaves and roots of many Vitis species. The roots of the cultivated V. vinifera cultivars and hybrids are highly susceptible to grape phylloxera feeding damage. The native range of this insect covers most of North America, and it is particularly abundant in the eastern and central United States. Phylloxera was introduced from North America to almost all grape-growing regions across five of the temperate zone continents. It devastated vineyards in each of these regions causing large-scale disruptions to grape growers, wine makers and national economies. In order to understand the population diversity of grape phylloxera in its native range, more than 500 samples from 19 States and 34 samples from the introduced range (northern California, Europe and South America) were genotyped with 32 simple sequence repeat markers. STRUCTURE, a model based clustering method identified five populations within these samples. The five populations were confirmed by a neighbor-joining tree and principal coordinate analysis (PCoA). These populations were distinguished by their Vitis species hosts and their geographic locations. Samples collected from California, Europe and South America traced back to phylloxera sampled in the northeastern United States on V. riparia, with some influence from phylloxera collected along the Atlantic Coast and Central Plains on V. vulpina. Reproductive statistics conclusively confirmed that sexual reproduction is common in the native range and is combined with cyclical parthenogenesis. Native grape phylloxera populations were identified to be under Hardy-Weinberg equilibrium. The identification of admixed samples between many of these populations indicates that shared environments facilitate sexual reproduction between different host associated populations to create new genotypes of phylloxera. This study also found that assortative mating might occur across the

  7. Population structure and temporal maintenance of the multihost fungal pathogen Botrytis cinerea: causes and implications for disease management.

    Science.gov (United States)

    Walker, Anne-Sophie; Gladieux, Pierre; Decognet, Véronique; Fermaud, Marc; Confais, Johann; Roudet, Jean; Bardin, Marc; Bout, Alexandre; Nicot, Philippe C; Poncet, Christine; Fournier, Elisabeth

    2015-04-01

    Understanding the causes of population subdivision is of fundamental importance, as studying barriers to gene flow between populations may reveal key aspects of the process of adaptive divergence and, for pathogens, may help forecasting disease emergence and implementing sound management strategies. Here, we investigated population subdivision in the multihost fungus Botrytis cinerea based on comprehensive multiyear sampling on different hosts in three French regions. Analyses revealed a weak association between population structure and geography, but a clear differentiation according to the host plant of origin. This was consistent with adaptation to hosts, but the distribution of inferred genetic clusters and the frequency of admixed individuals indicated a lack of strict host specificity. Differentiation between individuals collected in the greenhouse (on Solanum) and outdoor (on Vitis and Rubus) was stronger than that observed between individuals from the two outdoor hosts, probably reflecting an additional isolating effect associated with the cropping system. Three genetic clusters coexisted on Vitis but did not persist over time. Linkage disequilibrium analysis indicated that outdoor populations were regularly recombining, whereas clonality was predominant in the greenhouse. Our findings open up new perspectives for disease control by managing plant debris in outdoor conditions and reinforcing prophylactic measures indoor.

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

    Science.gov (United States)

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

    2012-07-01

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

  9. Population dynamics

    Directory of Open Access Journals (Sweden)

    Cooch, E. G.

    2004-06-01

    Full Text Available Increases or decreases in the size of populations over space and time are, arguably, the motivation for much of pure and applied ecological research. The fundamental model for the dynamics of any population is straightforward: the net change over time in the abundance of some population is the simple difference between the number of additions (individuals entering the population minus the number of subtractions (individuals leaving the population. Of course, the precise nature of the pattern and process of these additions and subtractions is often complex, and population biology is often replete with fairly dense mathematical representations of both processes. While there is no doubt that analysis of such abstract descriptions of populations has been of considerable value in advancing our, there has often existed a palpable discomfort when the ‘beautiful math’ is faced with the often ‘ugly realities’ of empirical data. In some cases, this attempted merger is abandoned altogether, because of the paucity of ‘good empirical data’ with which the theoretician can modify and evaluate more conceptually–based models. In some cases, the lack of ‘data’ is more accurately represented as a lack of robust estimates of one or more parameters. It is in this arena that methods developed to analyze multiple encounter data from individually marked organisms has seen perhaps the greatest advances. These methods have rapidly evolved to facilitate not only estimation of one or more vital rates, critical to population modeling and analysis, but also to allow for direct estimation of both the dynamics of populations (e.g., Pradel, 1996, and factors influencing those dynamics (e.g., Nichols et al., 2000. The interconnections between the various vital rates, their estimation, and incorporation into models, was the general subject of our plenary presentation by Hal Caswell (Caswell & Fujiwara, 2004. Caswell notes that although interest has traditionally

  10. Stellar Populations

    NARCIS (Netherlands)

    Peletier, Reynier F.

    2013-01-01

    This is a summary of my lectures during the 2011 Canary Islands Winter School in Puerto de la Cruz. I give an introduction to the field of stellar populations in galaxies, and highlight some new results. Since the title of the Winter School is Secular Evolution in Galaxies I mostly concentrate on ne

  11. Complete mitochondrial genome sequencing reveals novel haplotypes in a Polynesian population.

    Directory of Open Access Journals (Sweden)

    Miles Benton

    Full Text Available The high risk of metabolic disease traits in Polynesians may be partly explained by elevated prevalence of genetic variants involved in energy metabolism. The genetics of Polynesian populations has been shaped by island hoping migration events which have possibly favoured thrifty genes. The aim of this study was to sequence the mitochondrial genome in a group of Maoris in an effort to characterise genome variation in this Polynesian population for use in future disease association studies. We sequenced the complete mitochondrial genomes of 20 non-admixed Maori subjects using Affymetrix technology. DNA diversity analyses showed the Maori group exhibited reduced mitochondrial genome diversity compared to other worldwide populations, which is consistent with historical bottleneck and founder effects. Global phylogenetic analysis positioned these Maori subjects specifically within mitochondrial haplogroup--B4a1a1. Interestingly, we identified several novel variants that collectively form new and unique Maori motifs--B4a1a1c, B4a1a1a3 and B4a1a1a5. Compared to ancestral populations we observed an increased frequency of non-synonymous coding variants of several mitochondrial genes in the Maori group, which may be a result of positive selection and/or genetic drift effects. In conclusion, this study reports the first complete mitochondrial genome sequence data for a Maori population. Overall, these new data reveal novel mitochondrial genome signatures in this Polynesian population and enhance the phylogenetic picture of maternal ancestry in Oceania. The increased frequency of several mitochondrial coding variants makes them good candidates for future studies aimed at assessment of metabolic disease risk in Polynesian populations.

  12. The evolutionary dynamics of the lion Panthera leo revealed by host and viral population genomics.

    Directory of Open Access Journals (Sweden)

    Agostinho Antunes

    2008-11-01

    Full Text Available The lion Panthera leo is one of the world's most charismatic carnivores and is one of Africa's key predators. Here, we used a large dataset from 357 lions comprehending 1.13 megabases of sequence data and genotypes from 22 microsatellite loci to characterize its recent evolutionary history. Patterns of molecular genetic variation in multiple maternal (mtDNA, paternal (Y-chromosome, and biparental nuclear (nDNA genetic markers were compared with patterns of sequence and subtype variation of the lion feline immunodeficiency virus (FIV(Ple, a lentivirus analogous to human immunodeficiency virus (HIV. In spite of the ability of lions to disperse long distances, patterns of lion genetic diversity suggest substantial population subdivision (mtDNA Phi(ST = 0.92; nDNA F(ST = 0.18, and reduced gene flow, which, along with large differences in sero-prevalence of six distinct FIV(Ple subtypes among lion populations, refute the hypothesis that African lions consist of a single panmictic population. Our results suggest that extant lion populations derive from several Pleistocene refugia in East and Southern Africa ( approximately 324,000-169,000 years ago, which expanded during the Late Pleistocene ( approximately 100,000 years ago into Central and North Africa and into Asia. During the Pleistocene/Holocene transition ( approximately 14,000-7,000 years, another expansion occurred from southern refugia northwards towards East Africa, causing population interbreeding. In particular, lion and FIV(Ple variation affirms that the large, well-studied lion population occupying the greater Serengeti Ecosystem is derived from three distinct populations that admixed recently.

  13. The evolutionary dynamics of the lion Panthera leo revealed by host and viral population genomics.

    Science.gov (United States)

    Antunes, Agostinho; Troyer, Jennifer L; Roelke, Melody E; Pecon-Slattery, Jill; Packer, Craig; Winterbach, Christiaan; Winterbach, Hanlie; Hemson, Graham; Frank, Laurence; Stander, Philip; Siefert, Ludwig; Driciru, Margaret; Funston, Paul J; Alexander, Kathy A; Prager, Katherine C; Mills, Gus; Wildt, David; Bush, Mitch; O'Brien, Stephen J; Johnson, Warren E

    2008-11-01

    The lion Panthera leo is one of the world's most charismatic carnivores and is one of Africa's key predators. Here, we used a large dataset from 357 lions comprehending 1.13 megabases of sequence data and genotypes from 22 microsatellite loci to characterize its recent evolutionary history. Patterns of molecular genetic variation in multiple maternal (mtDNA), paternal (Y-chromosome), and biparental nuclear (nDNA) genetic markers were compared with patterns of sequence and subtype variation of the lion feline immunodeficiency virus (FIV(Ple)), a lentivirus analogous to human immunodeficiency virus (HIV). In spite of the ability of lions to disperse long distances, patterns of lion genetic diversity suggest substantial population subdivision (mtDNA Phi(ST) = 0.92; nDNA F(ST) = 0.18), and reduced gene flow, which, along with large differences in sero-prevalence of six distinct FIV(Ple) subtypes among lion populations, refute the hypothesis that African lions consist of a single panmictic population. Our results suggest that extant lion populations derive from several Pleistocene refugia in East and Southern Africa ( approximately 324,000-169,000 years ago), which expanded during the Late Pleistocene ( approximately 100,000 years ago) into Central and North Africa and into Asia. During the Pleistocene/Holocene transition ( approximately 14,000-7,000 years), another expansion occurred from southern refugia northwards towards East Africa, causing population interbreeding. In particular, lion and FIV(Ple) variation affirms that the large, well-studied lion population occupying the greater Serengeti Ecosystem is derived from three distinct populations that admixed recently.

  14. Winter fidelity and apparent survival of lesser snow goose populations in the Pacific flyway

    Science.gov (United States)

    Williams, C.K.; Samuel, M.D.; Baranyuk, Vasily V.; Cooch, E.G.; Kraege, Donald K.

    2008-01-01

    The Beringia region of the Arctic contains 2 colonies of lesser snow geese (Chen caerulescens caerulescens) breeding on Wrangel Island, Russia, and Banks Island, Canada, and wintering in North America. The Wrangel Island population is composed of 2 subpopulations from a sympatric breeding colony but separate wintering areas, whereas the Banks Island population shares a sympatric wintering area in California, USA, with one of the Wrangel Island subpopulations. The Wrangel Island colony represents the last major snow goose population in Russia and has fluctuated considerably since 1970, whereas the Banks Island population has more than doubled. The reasons for these changes are unclear, but hypotheses include independent population demographics (survival and recruitment) and immigration and emigration among breeding or wintering populations. These demographic and movement patterns have important ecological and management implications for understanding goose population structure, harvest of admixed populations, and gene flow among populations with separate breeding or wintering areas. From 1993 to 1996, we neckbanded molting birds at their breeding colonies and resighted birds on the wintering grounds. We used multistate mark-recapture models to evaluate apparent survival rates, resighting rates, winter fidelity, and potential exchange among these populations. We also compared the utility of face stain in Wrangel Island breeding geese as a predictor of their wintering area. Our results showed similar apparent survival rates between subpopulations of Wrangel Island snow geese and lower apparent survival, but higher emigration, for the Banks Island birds. Males had lower apparent survival than females, most likely due to differences in neckband loss. Transition between wintering areas was low (movement between northern and southern wintering areas for Wrangel Island birds and little evidence of exchange between the Banks and northern Wrangel Island populations. Face

  15. Population aging.

    Science.gov (United States)

    1999-04-01

    This paper focuses on the impact of population aging in China, the most densely populated country in the world. Statistics indicate that by the end of 1998, 83.75 million out of the 1.248 billion Chinese people will be over 65 years old. According to the UN standards, China will soon become an aging society. The aging population poses several challenges to the country with the greatest challenge being the increasing social responsibility to care for the aged. With the undeveloped legislative framework to protect the interests of the aged and the serious drawbacks in the pension system to cater only to the income part and not the service part of the aged, China is not yet ready for the advent of aging. Violation of the rights of senior citizens is still very rampant despite enactment of the law on Protection of the Rights of the Elderly in 1996. Moreover, China is not economically ready to become an aging society. China faces this challenge by adopting a three-pronged approach to solve the problem namely: family support, establishment of nursing homes, and creating a social security framework that addresses the needs of the society suited to the Chinese condition. It is believed that with the growing economy of the country and the rising income of its people, a comprehensive social security net will be created to take care of the aged.

  16. Stickleback Population

    Directory of Open Access Journals (Sweden)

    Ulrika Candolin

    2012-01-01

    Full Text Available Human-induced eutrophication has increased offspring production in a population of threespine stickleback Gasterosteus aculeatus in the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perch Perca fluviatilis (behind a transparent Plexiglas wall. However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.

  17. Population genomics reveals a possible history of backcrossing and recombination in the gynogenetic fish Poecilia formosa.

    Science.gov (United States)

    Alberici da Barbiano, Laura; Gompert, Zachariah; Aspbury, Andrea S; Gabor, Caitlin R; Nice, Chris C

    2013-08-20

    Unisexual sperm-dependent vertebrates are of hybrid origins, rare, and predicted to be short-lived as a result of several challenges arising from their mode of reproduction. In particular, because of a lack of recombination, clonal species are predicted to have a low potential to respond to natural selection. However, many unisexual sperm-dependent species persist, and assessing the genetic diversity present in these species is fundamental to understanding how they avoid extinction. We used population genomic methods to assess genotypic variation within the unisexual fish Poecilia formosa. Measures of admixture and population differentiation, as well as clustering analyses, indicate that the genomes of individuals of P. formosa are admixed and intermediate between Poecilia latipinna and Poecilia mexicana, consistent with the hypothesis of their hybrid origins. Bayesian genomic cline analyses indicate that about 12% of sampled loci exhibit patterns consistent with inheritance from only one parent. The estimation of observed heterozygosity clearly suggests that P. formosa is not comprised of direct descendants of a single nonrecombining asexual F1 hybrid individual. Additionally, the estimation of observed heterozygosity provides support for the hypothesis that the history of this unisexual species has included backcrossing with the parent species before the onset of gynogenesis. We also document high levels of variation among asexual individuals, which is attributable to recombination (historical or ongoing) and the accumulation of mutations. The high genetic variation suggests that this unisexual vertebrate has more potential to respond to natural selection than if they were frozen F1 hybrids.

  18. Assessment of Physico-chemical Water Quality of Birecik Dam, Şanlıurfa, West East Region, Turkey

    Directory of Open Access Journals (Sweden)

    Banu Kutlu

    2015-07-01

    Full Text Available In year 2013, onsite seasonal measurements have been carried out in 4 different points of Birecik Reservoir, and water samples have been taken from surface and different depths. Physical and chemical parameters have been investigated in taken water samples. The result of analysis were obtained in the following range pH (6.98-9, temperature (9.9-26 °C, electrical conductivity (275-373 µs/cm, sodium ( 19.93-22.06 mg/L, potassium (1.-2.2 mg/L, chloride/11.68-21.4, hardness (179-210 mg/L, calcium (41.66-52.9 mg/L, magnesium ((17-18.35 mg/L, sulphate (27.92-43.48 mg/L, dissolved oxygen (7.92-8.83 mg/L, chemical oxygen (0.25-8.70 mg/L, nitrate (0.62-2.48 mg/L, nitrate (0.001-0.008, ammonium (0.01-0.07, phosphate (0.001-0.031 mg/L. The samples were compared with standard values recommended by world health (WHO. The study finalize that Birecik reservoir which was declared to be a threat to the water quality should be arrested at denitrification and nutrient control to halt the degradation of the water.

  19. Low planktic foraminiferal diversity and abundance observed in a spring 2013 west-east Mediterranean Sea plankton tow transect

    Science.gov (United States)

    Mallo, Miguel; Ziveri, Patrizia; Mortyn, P. Graham; Schiebel, Ralf; Grelaud, Michael

    2017-05-01

    Planktic foraminifera were collected with 150 µm BONGO nets from the upper 200 m water depth at 20 stations across the Mediterranean Sea between 2 May and 2 June 2013. The main aim is to characterize the species distribution and test the covariance between foraminiferal area density (ρA) and seawater carbonate chemistry in a biogeochemical gradient including ultraoligotrophic conditions. Average foraminifera abundances are 1.42 ± 1.43 ind. 10 m-3 (ranging from 0.11 to 5.20 ind. 10 m-3), including 12 morphospecies. Large differences in species assemblages and total abundances are observed between the different Mediterranean sub-basins, with an overall dominance of spinose, symbiont-bearing species indicating oligotrophic conditions. The highest values in absolute abundance are found in the Strait of Gibraltar and the Alboran Sea. The western basin is dominated by Globorotalia inflata and Globigerina bulloides at slightly lower standing stocks than in the eastern basin. In contrast, the planktic foraminiferal assemblage in the warmer, saltier, and more nutrient-limited eastern basin is dominated by Globigerinoides ruber (white). These new results, when combined with previous findings, suggest that temperature-induced surface water stratification and food availability are the main factors controlling foraminiferal distribution. In the oligotrophic and highly alkaline and supersaturated with respect to calcite and aragonite Mediterranean surface water, standing stocks and ρA of G. ruber (white) and G. bulloides are affected by both food availability and seawater carbonate chemistry. Rapid warming increased surface ocean stratification impacting food availability and changes in trophic conditions could be the causes of reduced foraminiferal abundance, diversity, and species-specific changes in planktic foraminiferal calcification.

  20. Indian populations

    CERN Document Server

    Spahni,J

    1974-01-01

    Le Prof. J.C. Spahni qui a parcouru les Andes, Vénezuela etc. parle de ses expériences et connaissances qu'il a vécu au cours des 14 ans parmi les populations indiennes de la Cordillière des Andes. Il a ramené des objets artisanals indiens lesquels l'auditoire peut acquérir. L'introduction-conférence est suivi d'un film, commenté par lui-même; après l'entracte il y un débat-dialogue avec le public.

  1. Population Genetics with Fluctuating Population Sizes

    CERN Document Server

    Chotibut, Thiparat

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuations-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

  2. Population Genetics with Fluctuating Population Sizes

    Science.gov (United States)

    Chotibut, Thiparat; Nelson, David R.

    2017-05-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges naturally and allows adiabatic elimination of a fast population size variable to deduce the fluctuation-induced selection dynamics near the equilibrium population size. The results highlight the incompleteness of the standard population genetics with a strictly fixed population size.

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

    Directory of Open Access Journals (Sweden)

    Marwa A. Eltanany

    2016-09-01

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

  4. Pitfalls of the Geographic Population Structure (GPS) Approach Applied to Human Genetic History: A Case Study of Ashkenazi Jews.

    Science.gov (United States)

    Flegontov, Pavel; Kassian, Alexei; Thomas, Mark G; Fedchenko, Valentina; Changmai, Piya; Starostin, George

    2016-08-16

    In a recent interdisciplinary study, Das et al. have attempted to trace the homeland of Ashkenazi Jews and of their historical language, Yiddish (Das et al. 2016 Localizing Ashkenazic Jews to Primeval Villages in the Ancient Iranian Lands of Ashkenaz. Genome Biol Evol. 8:1132-1149). Das et al. applied the geographic population structure (GPS) method to autosomal genotyping data and inferred geographic coordinates of populations supposedly ancestral to Ashkenazi Jews, placing them in Eastern Turkey. They argued that this unexpected genetic result goes against the widely accepted notion of Ashkenazi origin in the Levant, and speculated that Yiddish was originally a Slavic language strongly influenced by Iranian and Turkic languages, and later remodeled completely under Germanic influence. In our view, there are major conceptual problems with both the genetic and linguistic parts of the work. We argue that GPS is a provenancing tool suited to inferring the geographic region where a modern and recently unadmixed genome is most likely to arise, but is hardly suitable for admixed populations and for tracing ancestry up to 1,000 years before present, as its authors have previously claimed. Moreover, all methods of historical linguistics concur that Yiddish is a Germanic language, with no reliable evidence for Slavic, Iranian, or Turkic substrata.

  5. compressibility characteristics of black cotton soil admixed with ...

    African Journals Online (AJOL)

    user

    gravity and particle size distribution were also carried out on the soil sample. Sawdust ash ... Analysis of the results obtained from the laboratory tests conducted on the soil samples and ..... plasticity index and thus this value was maintained.

  6. Africanization of a feral honey bee (Apis mellifera) population in South Texas: does a decade make a difference?

    Science.gov (United States)

    Rangel, Juliana; Giresi, Melissa; Pinto, Maria Alice; Baum, Kristen A; Rubink, William L; Coulson, Robert N; Johnston, John Spencer

    2016-04-01

    The arrival to the United States of the Africanized honey bee, a hybrid between European subspecies and the African subspecies Apis mellifera scutellata, is a remarkable model for the study of biological invasions. This immigration has created an opportunity to study the dynamics of secondary contact of honey bee subspecies from African and European lineages in a feral population in South Texas. An 11-year survey of this population (1991-2001) showed that mitochondrial haplotype frequencies changed drastically over time from a resident population of eastern and western European maternal ancestry, to a population dominated by the African haplotype. A subsequent study of the nuclear genome showed that the Africanization process included bidirectional gene flow between European and Africanized honey bees, giving rise to a new panmictic mixture of A. m. scutellata- and European-derived genes. In this study, we examined gene flow patterns in the same population 23 years after the first hybridization event occurred. We found 28 active colonies inhabiting 92 tree cavities surveyed in a 5.14 km(2) area, resulting in a colony density of 5.4 colonies/km(2). Of these 28 colonies, 25 were of A. m. scutellata maternal ancestry, and three were of western European maternal ancestry. No colonies of eastern European maternal ancestry were detected, although they were present in the earlier samples. Nuclear DNA revealed little change in the introgression of A. m. scutellata-derived genes into the population compared to previous surveys. Our results suggest this feral population remains an admixed swarm with continued low levels of European ancestry and a greater presence of African-derived mitochondrial genetic composition.

  7. Subspecies genetic assignments of worldwide captive tigers increase conservation value of captive populations.

    Science.gov (United States)

    Luo, Shu-Jin; Johnson, Warren E; Martenson, Janice; Antunes, Agostinho; Martelli, Paolo; Uphyrkina, Olga; Traylor-Holzer, Kathy; Smith, James L D; O'Brien, Stephen J

    2008-04-22

    Tigers (Panthera tigris) are disappearing rapidly from the wild, from over 100,000 in the 1900s to as few as 3000. Javan (P.t. sondaica), Bali (P.t. balica), and Caspian (P.t. virgata) subspecies are extinct, whereas the South China tiger (P.t. amoyensis) persists only in zoos. By contrast, captive tigers are flourishing, with 15,000-20,000 individuals worldwide, outnumbering their wild relatives five to seven times. We assessed subspecies genetic ancestry of 105 captive tigers from 14 countries and regions by using Bayesian analysis and diagnostic genetic markers defined by a prior analysis of 134 voucher tigers of significant genetic distinctiveness. We assigned 49 tigers to one of five subspecies (Bengal P.t. tigris, Sumatran P.t. sumatrae, Indochinese P.t. corbetti, Amur P.t. altaica, and Malayan P.t. jacksoni tigers) and determined 52 had admixed subspecies origins. The tested captive tigers retain appreciable genomic diversity unobserved in their wild counterparts, perhaps a consequence of large population size, century-long introduction of new founders, and managed-breeding strategies to retain genetic variability. Assessment of verified subspecies ancestry offers a powerful tool that, if applied to tigers of uncertain background, may considerably increase the number of purebred tigers suitable for conservation management.

  8. Extensive population admixture on drone congregation areas of the giant honeybee, Apis dorsata (Fabricius, 1793).

    Science.gov (United States)

    Beaurepaire, Alexis L; Kraus, Bernard F; Koeniger, Gudrun; Koeniger, Nikolaus; Lim, Herbert; Moritz, Robin F A

    2014-12-01

    The giant honeybee Apis dorsata often forms dense colony aggregations which can include up to 200 often closely related nests in the same location, setting the stage for inbred matings. Yet, like in all other Apis species, A. dorsata queens mate in mid-air on lek like drone congregation areas (DCAs) where large numbers of males gather in flight. We here report how the drone composition of A. dorsata DCAs facilitates outbreeding, taking into the account both spatial (three DCAs) and temporal (subsequent sampling days) dynamics. We compared the drones' genotypes at ten microsatellite DNA markers with those of the queen genotypes of six drone-producing colonies located close to the DCAs (Tenom, Sabah, Malaysia). None of 430 sampled drones originated from any of these nearby colonies. Moreover, we estimated that 141 unidentified colonies were contributing to the three DCAs. Most of these colonies were participating multiple times in the different locations and/or during the consecutive days of sampling. The drones sampled in the DCAs could be attributed to six subpopulations. These were all admixed in all DCA samples, increasing the effective population size an order of magnitude and preventing matings between potentially related queens and drones.

  9. Complex population structure in African village dogs and its implications for inferring dog domestication history.

    Science.gov (United States)

    Boyko, Adam R; Boyko, Ryan H; Boyko, Corin M; Parker, Heidi G; Castelhano, Marta; Corey, Liz; Degenhardt, Jeremiah D; Auton, Adam; Hedimbi, Marius; Kityo, Robert; Ostrander, Elaine A; Schoenebeck, Jeffrey; Todhunter, Rory J; Jones, Paul; Bustamante, Carlos D

    2009-08-18

    High genetic diversity of East Asian village dogs has recently been used to argue for an East Asian origin of the domestic dog. However, global village dog genetic diversity and the extent to which semiferal village dogs represent distinct, indigenous populations instead of admixtures of various dog breeds has not been quantified. Understanding these issues is critical to properly reconstructing the timing, number, and locations of dog domestication. To address these questions, we sampled 318 village dogs from 7 regions in Egypt, Uganda, and Namibia, measuring genetic diversity >680 bp of the mitochondrial D-loop, 300 SNPs, and 89 microsatellite markers. We also analyzed breed dogs, including putatively African breeds (Afghan hounds, Basenjis, Pharaoh hounds, Rhodesian ridgebacks, and Salukis), Puerto Rican street dogs, and mixed breed dogs from the United States. Village dogs from most African regions appear genetically distinct from non-native breed and mixed-breed dogs, although some individuals cluster genetically with Puerto Rican dogs or United States breed mixes instead of with neighboring village dogs. Thus, African village dogs are a mosaic of indigenous dogs descended from early migrants to Africa, and non-native, breed-admixed individuals. Among putatively African breeds, Pharaoh hounds, and Rhodesian ridgebacks clustered with non-native rather than indigenous African dogs, suggesting they have predominantly non-African origins. Surprisingly, we find similar mtDNA haplotype diversity in African and East Asian village dogs, potentially calling into question the hypothesis of an East Asian origin for dog domestication.

  10. SNPs in stress-responsive rice genes: validation, genotyping, functional relevance and population structure

    Directory of Open Access Journals (Sweden)

    Parida Swarup K

    2012-08-01

    Full Text Available Abstract Background Single nucleotide polymorphism (SNP validation and large-scale genotyping are required to maximize the use of DNA sequence variation and determine the functional relevance of candidate genes for complex stress tolerance traits through genetic association in rice. We used the bead array platform-based Illumina GoldenGate assay to validate and genotype SNPs in a select set of stress-responsive genes to understand their functional relevance and study the population structure in rice. Results Of the 384 putative SNPs assayed, we successfully validated and genotyped 362 (94.3%. Of these 325 (84.6% showed polymorphism among the 91 rice genotypes examined. Physical distribution, degree of allele sharing, admixtures and introgression, and amino acid replacement of SNPs in 263 abiotic and 62 biotic stress-responsive genes provided clues for identification and targeted mapping of trait-associated genomic regions. We assessed the functional and adaptive significance of validated SNPs in a set of contrasting drought tolerant upland and sensitive lowland rice genotypes by correlating their allelic variation with amino acid sequence alterations in catalytic domains and three-dimensional secondary protein structure encoded by stress-responsive genes. We found a strong genetic association among SNPs in the nine stress-responsive genes with upland and lowland ecological adaptation. Higher nucleotide diversity was observed in indica accessions compared with other rice sub-populations based on different population genetic parameters. The inferred ancestry of 16% among rice genotypes was derived from admixed populations with the maximum between upland aus and wild Oryza species. Conclusions SNPs validated in biotic and abiotic stress-responsive rice genes can be used in association analyses to identify candidate genes and develop functional markers for stress tolerance in rice.

  11. Genomic evidence for island population conversion resolves conflicting theories of polar bear evolution.

    Science.gov (United States)

    Cahill, James A; Green, Richard E; Fulton, Tara L; Stiller, Mathias; Jay, Flora; Ovsyanikov, Nikita; Salamzade, Rauf; St John, John; Stirling, Ian; Slatkin, Montgomery; Shapiro, Beth

    2013-01-01

    Despite extensive genetic analysis, the evolutionary relationship between polar bears (Ursus maritimus) and brown bears (U. arctos) remains unclear. The two most recent comprehensive reports indicate a recent divergence with little subsequent admixture or a much more ancient divergence followed by extensive admixture. At the center of this controversy are the Alaskan ABC Islands brown bears that show evidence of shared ancestry with polar bears. We present an analysis of genome-wide sequence data for seven polar bears, one ABC Islands brown bear, one mainland Alaskan brown bear, and a black bear (U. americanus), plus recently published datasets from other bears. Surprisingly, we find clear evidence for gene flow from polar bears into ABC Islands brown bears but no evidence of gene flow from brown bears into polar bears. Importantly, while polar bears contributed <1% of the autosomal genome of the ABC Islands brown bear, they contributed 6.5% of the X chromosome. The magnitude of sex-biased polar bear ancestry and the clear direction of gene flow suggest a model wherein the enigmatic ABC Island brown bears are the descendants of a polar bear population that was gradually converted into brown bears via male-dominated brown bear admixture. We present a model that reconciles heretofore conflicting genetic observations. We posit that the enigmatic ABC Islands brown bears derive from a population of polar bears likely stranded by the receding ice at the end of the last glacial period. Since then, male brown bear migration onto the island has gradually converted these bears into an admixed population whose phenotype and genotype are principally brown bear, except at mtDNA and X-linked loci. This process of genome erosion and conversion may be a common outcome when climate change or other forces cause a population to become isolated and then overrun by species with which it can hybridize.

  12. Genomic evidence for island population conversion resolves conflicting theories of polar bear evolution.

    Directory of Open Access Journals (Sweden)

    James A Cahill

    Full Text Available Despite extensive genetic analysis, the evolutionary relationship between polar bears (Ursus maritimus and brown bears (U. arctos remains unclear. The two most recent comprehensive reports indicate a recent divergence with little subsequent admixture or a much more ancient divergence followed by extensive admixture. At the center of this controversy are the Alaskan ABC Islands brown bears that show evidence of shared ancestry with polar bears. We present an analysis of genome-wide sequence data for seven polar bears, one ABC Islands brown bear, one mainland Alaskan brown bear, and a black bear (U. americanus, plus recently published datasets from other bears. Surprisingly, we find clear evidence for gene flow from polar bears into ABC Islands brown bears but no evidence of gene flow from brown bears into polar bears. Importantly, while polar bears contributed <1% of the autosomal genome of the ABC Islands brown bear, they contributed 6.5% of the X chromosome. The magnitude of sex-biased polar bear ancestry and the clear direction of gene flow suggest a model wherein the enigmatic ABC Island brown bears are the descendants of a polar bear population that was gradually converted into brown bears via male-dominated brown bear admixture. We present a model that reconciles heretofore conflicting genetic observations. We posit that the enigmatic ABC Islands brown bears derive from a population of polar bears likely stranded by the receding ice at the end of the last glacial period. Since then, male brown bear migration onto the island has gradually converted these bears into an admixed population whose phenotype and genotype are principally brown bear, except at mtDNA and X-linked loci. This process of genome erosion and conversion may be a common outcome when climate change or other forces cause a population to become isolated and then overrun by species with which it can hybridize.

  13. Characterization of mitochondrial haplogroups in a large population-based sample from the United States.

    Science.gov (United States)

    Mitchell, Sabrina L; Goodloe, Robert; Brown-Gentry, Kristin; Pendergrass, Sarah A; Murdock, Deborah G; Crawford, Dana C

    2014-07-01

    Mitochondrial DNA (mtDNA) haplogroups are valuable for investigations in forensic science, molecular anthropology, and human genetics. In this study, we developed a custom panel of 61 mtDNA markers for high-throughput classification of European, African, and Native American/Asian mitochondrial haplogroup lineages. Using these mtDNA markers, we constructed a mitochondrial haplogroup classification tree and classified 18,832 participants from the National Health and Nutrition Examination Surveys (NHANES). To our knowledge, this is the largest study to date characterizing mitochondrial haplogroups in a population-based sample from the United States, and the first study characterizing mitochondrial haplogroup distributions in self-identified Mexican Americans separately from Hispanic Americans of other descent. We observed clear differences in the distribution of maternal genetic ancestry consistent with proposed admixture models for these subpopulations, underscoring the genetic heterogeneity of the United States Hispanic population. The mitochondrial haplogroup distributions in the other self-identified racial/ethnic groups within NHANES were largely comparable to previous studies. Mitochondrial haplogroup classification was highly concordant with self-identified race/ethnicity (SIRE) in non-Hispanic whites (94.8 %), but was considerably lower in admixed populations including non-Hispanic blacks (88.3 %), Mexican Americans (81.8 %), and other Hispanics (61.6 %), suggesting SIRE does not accurately reflect maternal genetic ancestry, particularly in populations with greater proportions of admixture. Thus, it is important to consider inconsistencies between SIRE and genetic ancestry when performing genetic association studies. The mitochondrial haplogroup data that we have generated, coupled with the epidemiologic variables in NHANES, is a valuable resource for future studies investigating the contribution of mtDNA variation to human health and disease.

  14. Population Genetics with Fluctuating Population Sizes

    OpenAIRE

    Chotibut, Thiparat; Nelson, David R.

    2016-01-01

    Standard neutral population genetics theory with a strictly fixed population size has important limitations. An alternative model that allows independently fluctuating population sizes and reproduces the standard neutral evolution is reviewed. We then study a situation such that the competing species are neutral at the equilibrium population size but population size fluctuations nevertheless favor fixation of one species over the other. In this case, a separation of timescales emerges natural...

  15. Intra-and inter-population genetic diversity at the HLA-DQA1 locus and their implications for parentage analysis and human identification

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, F. [Instituto Mexicano del Seguro Social, Guadalajara, MX (United States)]|[Univ. of Texas Houston Health Science Center, Houston, TX (United States); Cerda-Flores, R. [Univ. of Texas Houston Health Science Center, Houston, TX (United States)]|[Centro de Investigacion Biomedica del Noreste, Monterrey, MX (United States); Zhong, Y. [Univ. of Texas Houston Health Science Center, TX (United States)] [and others

    1994-09-01

    HLA-DQA1 locus, studied by PCR-based sequence specific oligonucleotide probes, is highly polymorphic in all populations thus far studied. From the literature we compiled genotype and allele frequency data at this locus for 87 populations to examine the pattern of intra- and inter- population genetic diversity. In general, allele frequency variations in populations are consistent with their ethno-history, although small isolated populations (e.g. Pacific Islanders) exhibit somewhat disparate variations of allele frequencies. A nested gene diversity analysis of 41 populations, classified into 5 ethnic groups (African, n = 3; Caucasian, n = 18; American Native, n = 3; Asian, n = 8; Pacific Islanders, n = 9) showed that the total gene diversity (80.4%) is largely (95%) due to intra-population variation. Only 3% of the gene diversity is due to inter-population within ethnic group variation, with the remaining 2% due to between ethnic group variation. In terms of average heterozygosity, probability of paternity exlusion, and probability of individual identification, the inter-ethnic group variation is larger than that between poulation samples within the ethnic groups. No significant departure from Hardy-Weinberg expectations of genotype frequencies was observed in any population. With an average heterozygosity of 77% around the world, this locus provides a 57% chance of exclusion of a falsely accused person from paternity, and is able to exclude 91% of individuals for identification purposes. In terms of allele fequencies, the geometric positions of the admixed populations (e.g. African-Americans and American-Hispanics) are consistent with their admixture estimates in their gene pool.

  16. Genetic evidence on the origins of Indian caste populations.

    Science.gov (United States)

    Bamshad, M; Kivisild, T; Watkins, W S; Dixon, M E; Ricker, C E; Rao, B B; Naidu, J M; Prasad, B V; Reddy, P G; Rasanayagam, A; Papiha, S S; Villems, R; Redd, A J; Hammer, M F; Nguyen, S V; Carroll, M L; Batzer, M A; Jorde, L B

    2001-06-01

    The origins and affinities of the approximately 1 billion people living on the subcontinent of India have long been contested. This is owing, in part, to the many different waves of immigrants that have influenced the genetic structure of India. In the most recent of these waves, Indo-European-speaking people from West Eurasia entered India from the Northwest and diffused throughout the subcontinent. They purportedly admixed with or displaced indigenous Dravidic-speaking populations. Subsequently they may have established the Hindu caste system and placed themselves primarily in castes of higher rank. To explore the impact of West Eurasians on contemporary Indian caste populations, we compared mtDNA (400 bp of hypervariable region 1 and 14 restriction site polymorphisms) and Y-chromosome (20 biallelic polymorphisms and 5 short tandem repeats) variation in approximately 265 males from eight castes of different rank to approximately 750 Africans, Asians, Europeans, and other Indians. For maternally inherited mtDNA, each caste is most similar to Asians. However, 20%-30% of Indian mtDNA haplotypes belong to West Eurasian haplogroups, and the frequency of these haplotypes is proportional to caste rank, the highest frequency of West Eurasian haplotypes being found in the upper castes. In contrast, for paternally inherited Y-chromosome variation each caste is more similar to Europeans than to Asians. Moreover, the affinity to Europeans is proportionate to caste rank, the upper castes being most similar to Europeans, particularly East Europeans. These findings are consistent with greater West Eurasian male admixture with castes of higher rank. Nevertheless, the mitochondrial genome and the Y chromosome each represents only a single haploid locus and is more susceptible to large stochastic variation, bottlenecks, and selective sweeps. Thus, to increase the power of our analysis, we assayed 40 independent, biparentally inherited autosomal loci (1 LINE-1 and 39 Alu elements

  17. Population data of 23 STR loci (PowerPlex® Fusion System) in Mexican Mestizos from the West Region.

    Science.gov (United States)

    Aguilar-Velázquez, J A; Martínez-Cortés, G; Inclán-Sánchez, A; Romero-Rentería, O; Díaz-Navarro, X X; Rangel-Villalobos, H

    2016-11-01

    We analyzed 238 unrelated Mestizo (admixed) individuals from the West region of Mexico with the PowerPlex® Fusion System (Promega Corp.). Allele frequencies and forensic parameters were estimated for the 23 STRs included in this kit. Hardy-Weinberg equilibrium by locus and non-association between pair of loci were demonstrated by exact tests in this population. The combined PE and PD offered by this HID kit were ≥0.9999999986, representing a substantial improvement with respect to those previously offered by 15 STR systems. Interpopulation comparison by AMOVA tests demonstrated low but significant differences among Mexican Mestizos from West, Center, and Northeast regions (Fst = 0.01558; p = 0.0000), similar to the observed among three main ethnic groups from USA (Fst = 0.02048; p = 0.0000). This finding is consistent with the contrary clines of European and Amerindian ancestries described throughout the Mexican territory for Mestizos, the largest population (~90 %) in this country.

  18. Effective population size of korean populations.

    Science.gov (United States)

    Park, Leeyoung

    2014-12-01

    Recently, new methods have been developed for estimating the current and recent changes in effective population sizes. Based on the methods, the effective population sizes of Korean populations were estimated using data from the Korean Association Resource (KARE) project. The overall changes in the population sizes of the total populations were similar to CHB (Han Chinese in Beijing, China) and JPT (Japanese in Tokyo, Japan) of the HapMap project. There were no differences in past changes in population sizes with a comparison between an urban area and a rural area. Age-dependent current and recent effective population sizes represent the modern history of Korean populations, including the effects of World War II, the Korean War, and urbanization. The oldest age group showed that the population growth of Koreans had already been substantial at least since the end of the 19th century.

  19. EDARV370A associated facial characteristics in Uyghur population revealing further pleiotropic effects.

    Science.gov (United States)

    Peng, Qianqian; Li, Jinxi; Tan, Jingze; Yang, Yajun; Zhang, Manfei; Wu, Sijie; Liu, Yu; Zhang, Juan; Qin, Pengfei; Guan, Yaqun; Jiao, Yi; Zhang, Zhaoxia; Sabeti, Pardis C; Tang, Kun; Xu, Shuhua; Jin, Li; Wang, Sijia

    2016-01-01

    An adaptive variant of human Ectodysplasin receptor, EDARV370A, had undergone strong positive selection in East Asia. In mice and humans, EDARV370A was found to affect ectodermal-derived characteristics, including hair thickness, hair shape, active sweat gland density and teeth formation. Facial characteristics are also largely ectodermal derived. In this study, taking advantage of an admixed population of East Asian and European ancestry-the Uyghur, we aim to test whether EDARV370A is affecting facial characteristics and to investigate its pleiotropic nature and genetic model. In a sample of 1027 Uyghurs, we discover that EDARV370A is significantly associated with several facial characteristics, in particular shape of earlobe (P = 3.64 × 10 (-6) ) and type of chin (P = 9.23 × 10 (-5) ), with successful replication in other East Asian populations. Additionally, in this Uyghur population, we replicate previous association findings of incisors shoveling (P = 1.02 × 10 (-7) ), double incisors shoveling (P = 1.86 × 10 (-12) ) and hair straightness (P = 3.99 × 10 (-16) ), providing strong evidence supporting an additive model for the EDARV370A associations. Partial least square path model confirms EDARV370A systematically affect these weakly related ectodermal-derived characteristics, suggesting the pleiotropic effect of EDARV370A mainly plays roles in early embryo development. This study extends our knowledge about the pleiotropic nature of EDARV370A and provides potential clues to its adaptation fitness in human evolution.

  20. Surnames, geographic altitude, and digital dermatoglyphics in a male population from the province of Jujuy (Argentina).

    Science.gov (United States)

    Dipierri, José E; Gutiérrez-Redomero, Esperanza; Alonso-Rodríguez, Concepción; Alfaro, Emma; Demarchi, Dario; Rivaldería, Noemí

    2014-06-01

    The possible association between finger dermatoglyphic patterns and altitude and surname distribution was analyzed in a sample of adult males from the province of Jujuy, Argentina. We also investigated the biological affinity of this population with other South American natives and admixed populations. Fingerprints were obtained from 996 healthy men, aged 18-20 years, from the highlands (HL: 2500m, Puna and Quebrada) and lowlands (LL: Valle and Selvas). Surnames were classified into native/autochthonous (A) or foreign (F), resulting in three surname classes: FF, when both paternal and maternal surnames were of foreign origin; FA, when one surname was foreign and the other was native; and AA, when both surnames were native. Frequencies of finger dermatoglyphic patterns - arches (A), radial loops (RL), ulnar loops (UL), and whorls (W) - were determined for each digit in relation to geographic location, altitude, and surname origin, resulting in the following categories: HL-FF, HL-FA, HL-AA, LL-FF, LL-FA, and LL-AA. The statistical analyses showed that UL and RL were more common in individuals of HL origin, whereas W and A were more frequent in the LL males (pdermatoglyphic patterns and surname origin when geographic altitude was considered. In the HL group, UL was associated with AA and FA; in the LL group, the presence of A was associated with FF and FA. The distribution of dermatoglyphic patterns shows that the population of Jujuy belongs to the Andean gene pool and that it has undergone differential levels of admixture related to altitude.

  1. Education Vital Signs: Population.

    Science.gov (United States)

    Zakariya, Sally Banks

    1985-01-01

    Population changes and demographics shape the future of public schools. Includes statistics on ethnic makeup of student population, the projected baby boomlet, children of working mothers, households without children, and the aging population. (MD)

  2. Why Population in 1974?

    Science.gov (United States)

    O'Connor, Marion

    1974-01-01

    Discusses the impact of world population growth leading to the establishment of the United Nations Fund for Population Activities and to the declaration of 1974 as World Population Year. Previews some of the parameters and interconnecting interests to be considered during this year of intensive population study. (JR)

  3. Understanding Rural Population Loss.

    Science.gov (United States)

    McGranahan, David A.; Beale, Calvin L.

    2002-01-01

    A quarter of nonmetro counties lost population in the 1990s, but population loss was not related to poverty rate or low educational levels, perhaps because low-skill workers can no longer expect better wages in urban areas. Population loss was related to low population density and remoteness (which decrease access to services), lack of natural…

  4. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  5. Human Population Problems

    Science.gov (United States)

    Emmel, Thomas C.; Sligh, Michael M.

    1970-01-01

    Asserts that overpopulation is the most pressing world problem. Topics discussed include population control in primitive societies, population growth and control in modern societies, methods of motivational population control, consequences of no population control, and mass famines during the 1970's in underdeveloped countries. Cities 33…

  6. The effect of habitat fragmentation on the genetic structure of a top predator: loss of diversity and high differentiation among remnant populations of Atlantic Forest jaguars (Panthera onca).

    Science.gov (United States)

    Haag, T; Santos, A S; Sana, D A; Morato, R G; Cullen, L; Crawshaw, P G; De Angelo, C; Di Bitetti, M S; Salzano, F M; Eizirik, E

    2010-11-01

    Habitat fragmentation may disrupt original patterns of gene flow and lead to drift-induced differentiation among local population units. Top predators such as the jaguar may be particularly susceptible to this effect, given their low population densities, leading to small effective sizes in local fragments. On the other hand, the jaguar's high dispersal capabilities and relatively long generation time might counteract this process, slowing the effect of drift on local populations over the time frame of decades or centuries. In this study, we have addressed this issue by investigating the genetic structure of jaguars in a recently fragmented Atlantic Forest region, aiming to test whether loss of diversity and differentiation among local populations are detectable, and whether they can be attributed to the recent effect of drift. We used 13 microsatellite loci to characterize the genetic diversity present in four remnant populations, and observed marked differentiation among them, with evidence of recent allelic loss in local areas. Although some migrant and admixed individuals were identified, our results indicate that recent large-scale habitat removal and fragmentation among these areas has been sufficiently strong to promote differentiation induced by drift and loss of alleles at each site. Low estimated effective sizes supported the inference that genetic drift could have caused this effect within a short time frame. These results indicate that jaguars' ability to effectively disperse across the human-dominated landscapes that separate the fragments is currently very limited, and that each fragment contains a small, isolated population that is already suffering from the effects of genetic drift. © 2010 Blackwell Publishing Ltd.

  7. Genetic Diversity and Population Structure in Aromatic and Quality Rice (Oryza sativa L. Landraces from North-Eastern India.

    Directory of Open Access Journals (Sweden)

    Somnath Roy

    Full Text Available The North-eastern (NE India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, aromatic rice accessions from Nagaland; and P3, chakhao rice germplasm from Manipur [corrected]. Pair-wise FST between three groups varied from 0.223 (P1 vs P2 to 0.453 (P2 vs P3. With reference to the global classification of rice cultivars, two major groups (Indica and Japonica were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of

  8. Genetic Diversity and Population Structure in Aromatic and Quality Rice (Oryza sativa L.) Landraces from North-Eastern India

    Science.gov (United States)

    Mawkhlieng, Bandapkuper; Misra, A. K.; Pattanayak, A.; Harish, G. D.; Singh, S. K.; Ngachan, S. V.; Bansal, K. C.

    2015-01-01

    The North-eastern (NE) India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR) markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, chakhao rice germplasm from Manipur; and P3, aromatic rice accessions from Nagaland. Pair-wise FST between three groups varied from 0.223 (P1 vs P2) to 0.453 (P2 vs P3). With reference to the global classification of rice cultivars, two major groups (Indica and Japonica) were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of aromatic and quality rice

  9. Multiple Population Theory: Extreme helium population problem

    OpenAIRE

    Yi, Sukyoung K.

    2009-01-01

    The spreads in chemical abundances inferred by recent precision observations suggest that some or possibly all globular clusters can no longer be considered as simple stellar populations. The most striking case is omega Cen in the sense that its bluest main-sequence despite its high metallicity demands an extreme helium abundance of Y > 0.4. I focus on this issue of "the extreme helium population problem" in this review.

  10. Glaucoma in Asian Populations

    Science.gov (United States)

    ... Us Donate In This Section Glaucoma In Asian Populations email Send this article to a friend by ... an even more serious problem as the world population and longevity increases. The other major glaucoma type ...

  11. The Growing Human Population.

    Science.gov (United States)

    Keyfitz, Nathan

    1989-01-01

    Discusses the issue of human population. Illustrates the projections of the growing human population in terms of developed and less developed countries. Describes the family planning programs in several countries. Lists three references for further reading. (YP)

  12. Population control charts for population data.

    Science.gov (United States)

    Hansen, John P

    2007-01-01

    Healthcare managers are beginning to collect full population data, rather than sample data, on some patient and performance measures. For example, hospitals and healthcare systems already gather and store comprehensive data on admissions, ambulatory encounters, and other procedures. And as the electronic medical record is more widely used, complete population data will be collected on an even wider range of clinical measures, such as blood pressure and Laboratory values, in both inpatient and outpatient settings. To correctly monitor process quality when working with full population data, rather than sample data, healthcare managers will need appropriate statistical tools. Traditional control charts, which are used for tracking processes over time, are not suitable for such population data because they are based on the assumption that sample data are being collected. The author proposes a new type of control chart specifically for use with such population data: population control charts. These control charts can be used for monitoring processes that have output measures with continuous, binomial, or nonbinomial rate variables.

  13. Controlling Population with Pollution

    Science.gov (United States)

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  14. Modeling Exponential Population Growth

    Science.gov (United States)

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  15. Controlling Population with Pollution

    Science.gov (United States)

    Browne, Joseph

    2010-01-01

    Population models are often discussed in algebra, calculus, and differential equations courses. In this article we will use the human population of the world as our application. After quick looks at two common models we'll investigate more deeply a model which incorporates the negative effect that accumulated pollution may have on population.

  16. Modeling Exponential Population Growth

    Science.gov (United States)

    McCormick, Bonnie

    2009-01-01

    The concept of population growth patterns is a key component of understanding evolution by natural selection and population dynamics in ecosystems. The National Science Education Standards (NSES) include standards related to population growth in sections on biological evolution, interdependence of organisms, and science in personal and social…

  17. Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation.

    Science.gov (United States)

    Puckett, Emily E; Kristensen, Thea V; Wilton, Clay M; Lyda, Sara B; Noyce, Karen V; Holahan, Paula M; Leslie, David M; Beringer, Jeff; Belant, Jerrold L; White, Don; Eggert, Lori S

    2014-05-01

    Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas.

  18. Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation

    Science.gov (United States)

    Puckett, Emily E.; Kristensen, Thea V.; Wilton, Clay M.; Lyda, Sara B.; Noyce, Karen V.; Holahan, Paula M.; Leslie,, David M.; Beringer, J.; Belant, Jerrold L.; White, D.; Eggert, L.S.

    2014-01-01

    Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas.

  19. Mezcla génica en una muestra poblacional de la ciudad de Buenos Aires Gene mixture in a population sample from Buenos Aires City

    Directory of Open Access Journals (Sweden)

    Sergio A. Avena

    2006-04-01

    Full Text Available Este estudio tiene como objetivo estimar la mezcla génica en la población de la Ciudad de Buenos Aires, a partir de muestras de dadores de sangre provenientes de un centro público de salud (Hospital de Clínicas. Los estudios se realizaron sobre 218 personas no emparentadas que donaron su sangre durante el año 2002. Se analizaron 8 sistemas genéticos eritrocitarios y los alotipos GM/KM. Se realizó una encuesta con la finalidad de obtener información sobre lugar de nacimiento, residencia actual y datos genealógicos de los dadores. Las frecuencias génicas se determinaron empleando métodos de máxima verosimilitud. Para calcular la mezcla génica se aplicó el programa ADMIX (trihíbrido. Se registró un 15.8% de aporte indígena (AI y 4.3% de africano (AA. Estos datos se compararon con un estudio previo realizado en un centro privado (Hospital Italiano de Buenos Aires, no observándose diferencias significativas salvo en el sistema Km. Los resultados obtenidos se corresponden con la información histórica y demográfica de la ciudad de Buenos Aires.The aim of this study is to estimate the gene admixture in the population of Buenos Aires City from samples of blood donors, which come from a public health centre (Hospital de Clínicas. These studies were performed on 218 unrelated people, who donated blood during the year 2002. Eight erythrocyte genetic systems and GM/KM allotypes were analysed. A survey to obtain information about place of birth, present residence and genealogical data of the donors was performed. The gene frequencies were determined using a method of maximum likelihood. The genetic admixture was calculated through the ADMIX program (trihibride. The Amerindian and African contributions were 15.8% and 4.3% respectively. These data were compared with those obtained in a previous study performed in a private centre (Hospital Italiano de Buenos Aires and significant differences were observed, except in the KM system. The

  20. Molecular Population Genetics

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-01-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. PMID:28270526

  1. Molecular Population Genetics.

    Science.gov (United States)

    Casillas, Sònia; Barbadilla, Antonio

    2017-03-01

    Molecular population genetics aims to explain genetic variation and molecular evolution from population genetics principles. The field was born 50 years ago with the first measures of genetic variation in allozyme loci, continued with the nucleotide sequencing era, and is currently in the era of population genomics. During this period, molecular population genetics has been revolutionized by progress in data acquisition and theoretical developments. The conceptual elegance of the neutral theory of molecular evolution or the footprint carved by natural selection on the patterns of genetic variation are two examples of the vast number of inspiring findings of population genetics research. Since the inception of the field, Drosophila has been the prominent model species: molecular variation in populations was first described in Drosophila and most of the population genetics hypotheses were tested in Drosophila species. In this review, we describe the main concepts, methods, and landmarks of molecular population genetics, using the Drosophila model as a reference. We describe the different genetic data sets made available by advances in molecular technologies, and the theoretical developments fostered by these data. Finally, we review the results and new insights provided by the population genomics approach, and conclude by enumerating challenges and new lines of inquiry posed by increasingly large population scale sequence data. Copyright © 2017 Casillas and Barbadilla.

  2. Population education country programmes.

    Science.gov (United States)

    1980-12-01

    Population education country programs in the countries of India, Malaysia, Nepal, the Philippines, and Sri Lanka are reviewed. In India the machinery is beginning to roll for the nationwide implementation of a 3-year national population education project. A variety of strategies will be used at the national and state levels using existing facilities and infrastructure for implementing various aspects of the program. Recommendations and proposed project activities arrived at during 2 workshop/training programs are outlined. The Malaysian population education program recently developed a working draft of the scope, content, and objectives of population education at the primary and lower and upper secondary levels. This working draft is being pretested among teachers and curriculum developers, and, once revised, it will serve as the overall guiding framework for those responsible for preparing curriculum and instructional materials on population education. The population education program in Nepal will be implemented by 3 units: Curriculum, Textbook, Supervision, and Development Center; Tribhuvan University; and Division of Adult Education. The longterm objective is to institutionalize population education in the formal and nonformal education programs including the university. The Population Education Program of the Philippines has prepared a reader in Filipino for grade 3 pupils. Population education in the country has been promoted to a lesser degree in private than in public schools. the Institutional Development Program of the Population Center Foundation conducted a Summer Institute in Instructional Product Development for the primary purpose of institutionalizing population in the social science curriculum at the tertiary level. The population education program of Sri Lanka will undergo a revival in the recently approved 2-year project agreement between Sri Lanka's government and the United Nations Fund for Population Activities.

  3. Genetic structure of the tree peony (Paeonia rockii and the Qinling Mountains as a geographic barrier driving the fragmentation of a large population.

    Directory of Open Access Journals (Sweden)

    Jun-hui Yuan

    Full Text Available BACKGROUND: Tree peonies are great ornamental plants associated with a rich ethnobotanical history in Chinese culture and have recently been used as an evolutionary model. The Qinling Mountains represent a significant geographic barrier in Asia, dividing mainland China into northern (temperate and southern (semi-tropical regions; however, their flora has not been well analyzed. In this study, the genetic differentiation and genetic structure of Paeonia rockii and the role of the Qinling Mountains as a barrier that has driven intraspecific fragmentation were evaluated using 14 microsatellite markers. METHODOLOGY/PRINCIPAL FINDINGS: Twenty wild populations were sampled from the distributional range of P. rockii. Significant population differentiation was suggested (F(ST value of 0.302. Moderate genetic diversity at the population level (H(S of 0.516 and high population diversity at the species level (H(T of 0.749 were detected. Significant excess homozygosity (F(IS of 0.076 and recent population bottlenecks were detected in three populations. Bayesian clusters, population genetic trees and principal coordinate analysis all classified the P. rockii populations into three genetic groups and one admixed Wenxian population. An isolation-by-distance model for P. rockii was suggested by Mantel tests (r = 0.6074, P<0.001 and supported by AMOVA (P<0.001, revealing a significant molecular variance among the groups (11.32% and their populations (21.22%. These data support the five geographic boundaries surrounding the Qinling Mountains and adjacent areas that were detected with Monmonier's maximum-difference algorithm. CONCLUSIONS/SIGNIFICANCE: Our data suggest that the current genetic structure of P. rockii has resulted from the fragmentation of a formerly continuously distributed large population following the restriction of gene flow between populations of this species by the Qinling Mountains. This study provides a fundamental genetic profile for

  4. Investigation of KIF6 Trp719Arg in a case-control study of myocardial infarction: a Costa Rican population.

    Directory of Open Access Journals (Sweden)

    Lance A Bare

    Full Text Available BACKGROUND AND METHODOLOGY: The 719Arg allele of KIF6 (rs20455 was associated with coronary events in Caucasian participants of five prospective studies. We investigated whether this KIF6 variant was associated with non-fatal myocardial infarction (MI in a case-control study of an admixed population from the Central Valley of Costa Rica. Genotypes of the KIF6 variant were determined for 4,134 men and women. Cases (1,987 had survived a first MI; controls (2,147 had no history of MI and were matched to cases by age, sex, and area of residence. We tested the association between the KIF6 719Arg allele and non-fatal MI by conditional logistic regression and adjusted for admixture of founder populations. PRINCIPAL FINDINGS: Compared with the reference Trp/Trp homozygotes, KIF6 719Arg carriers were not at significantly higher risk for non-fatal MI in this study after adjustment for traditional risk factors or admixture (OR= 1.12; 95%CI, 0.98-1.28. Heterozygotes of the KIF6 Trp719Arg variant were at increased risk of non-fatal MI: the adjusted odds ratio was 1.16 (95% confidence interval, 1.01-1.34, but this association would not be significant after a multiple testing correction. CONCLUSIONS/SIGNIFICANCE: We found that carriers of the KIF6 719Arg allele were not at increased risk of non-fatal MI in a case-control study of Costa Ricans living in the Central Valley of Costa Rica.

  5. Environmental effects on molecular and phenotypic variation in populations of Eruca sativa across a steep climatic gradient.

    Science.gov (United States)

    Westberg, Erik; Ohali, Shachar; Shevelevich, Anatoly; Fine, Pinchas; Barazani, Oz

    2013-08-01

    In Israel Eruca sativa has a geographically narrow distribution across a steep climatic gradient that ranges from mesic Mediterranean to hot desert environments. These conditions offer an opportunity to study the influence of the environment on intraspecific genetic variation. For this, we combined an analysis of neutral genetic markers with a phenotypic evaluation in common-garden experiments, and environmental characterization of populations that included climatic and edaphic parameters, as well as geographic distribution. A Bayesian clustering of individuals from nine representative populations based on amplified fragment length polymorphism (AFLP) divided the populations into a southern and a northern geographic cluster, with one admixed population at the geographic border between them. Linear mixed models, with cluster added as a grouping factor, revealed no clear effects of environment or geography on genetic distances, but this may be due to a strong association of geography and environment with genetic clusters. However, environmental factors accounted for part of the phenotypic variation observed in the common-garden experiments. In addition, candidate loci for selection were identified by association with environmental parameters and by two outlier methods. One locus, identified by all three methods, also showed an association with trichome density and herbivore damage, in net-house and field experiments, respectively. Accordingly, we propose that because trichomes are directly linked to defense against both herbivores and excess radiation, they could potentially be related to adaptive variation in these populations. These results demonstrate the value of combining environmental and phenotypic data with a detailed genetic survey when studying adaptation in plant populations. This article describes the use of several types of data to estimate the influence of the environment on intraspecific genetic variation in populations originating from a steep

  6. Measurably evolving populations

    DEFF Research Database (Denmark)

    Drummond, Alexei James; Pybus, Oliver George; Rambaut, Andrew

    2003-01-01

    processes through time. Populations for which such studies are possible � measurably evolving populations (MEPs) � are characterized by sufficiently long or numerous sampled sequences and a fast mutation rate relative to the available range of sequence sampling times. The impact of sequences sampled through...... time has been most apparent in the disciplines of RNA viral evolution and ancient DNA, where they enable us to estimate divergence times without paleontological calibrations, and to analyze temporal changes in population size, population structure and substitution rates. Thus, MEPs could increase our...

  7. Population and development.

    Science.gov (United States)

    Okita, S

    1989-03-01

    This speech on the life and work of Rafael Salas, who had been the first executive director of the UN Population Fund (UNFPA) and who contributed immensely to global awareness of population as a vital issue, inaugurated the Rafael M. Salas Lecture Series at the UN. Salas was concerned with individual rights and socioeconomic development while maintaining a balance between population and the environment. He built a large multinational assistance program for population activities and increased funding from $2.5 million in 1969 to $175 million to support 2500 projects in 130 developing countries. He organized both the 1974 World Population Conference and the 1984 International Conference on Population. In developing countries malnutrition and poverty are intertwined, lowering productivity and making people prone to diseases. Infant and child mortality rises with the malnutrition of mothers, therefore campaigns modelled after the postwar Japanese efforts are needed to improve nutrition, to train dietitians, and to introduce school lunch programs. Population stabilization could also be achieved in developing countries by raising income levels, although in Latin American countries birth rates have stayed the same despite increasing income. Direct measures are effective in reducing the birth rate: primary school education, increased income, improved nutrition, decline in infant mortality, higher status of women, and decisive governmental population policy. The Club of Rome report The Limits to Growth predicted that sometime in the 21st century a sudden decline in both population and industrial capacity will be reached at the present growth trends.

  8. HLA-G variability and haplotypes detected by massively parallel sequencing procedures in the geographicaly distinct population samples of Brazil and Cyprus.

    Science.gov (United States)

    Castelli, Erick C; Gerasimou, Petroula; Paz, Michelle A; Ramalho, Jaqueline; Porto, Iane O P; Lima, Thálitta H A; Souza, Andréia S; Veiga-Castelli, Luciana C; Collares, Cristhianna V A; Donadi, Eduardo A; Mendes-Junior, Celso T; Costeas, Paul

    2017-03-01

    The HLA-G molecule presents immunomodulatory properties that might inhibit immune responses when interacting with specific Natural Killer and T cell receptors, such as KIR2DL4, ILT2 and ILT4. Thus, HLA-G might influence the outcome of situations in which fine immune system modulation is required, such as autoimmune diseases, transplants, cancer and pregnancy. The majority of the studies regarding the HLA-G gene variability so far was restricted to a specific gene segment (i.e., promoter, coding or 3' untranslated region), and was performed by using Sanger sequencing and probabilistic models to infer haplotypes. Here we propose a massively parallel sequencing (NGS) with a bioinformatics strategy to evaluate the entire HLA-G regulatory and coding segments, with haplotypes inferred relying more on the straightforward haplotyping capabilities of NGS, and less on probabilistic models. Then, HLA-G variability was surveyed in two admixed population samples of distinct geographical regions and demographic backgrounds, Cyprus and Brazil. Most haplotypes (promoters, coding, 3'UTR and extended ones) were detected both in Brazil and Cyprus and were identical to the ones already described by probabilistic models, indicating that these haplotypes are quite old and may be present worldwide. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Population Genetics of GYPB and Association Study between GYPB*S/s Polymorphism and Susceptibility to P. falciparum Infection in the Brazilian Amazon

    Science.gov (United States)

    Amaral, Daphne R. T.; Costa, Daiane C.; Furlani, Natália G.; Zuccherato, Luciana W.; Machado, Moara; Reid, Marion E.; Zalis, Mariano G.; Rossit, Andréa R.; Santos, Sidney E. B.; Machado, Ricardo L.; Lustigman, Sara

    2011-01-01

    Background Merozoites of Plasmodium falciparum invade through several pathways using different RBC receptors. Field isolates appear to use a greater variability of these receptors than laboratory isolates. Brazilian field isolates were shown to mostly utilize glycophorin A-independent invasion pathways via glycophorin B (GPB) and/or other receptors. The Brazilian population exhibits extensive polymorphism in blood group antigens, however, no studies have been done to relate the prevalence of the antigens that function as receptors for P. falciparum and the ability of the parasite to invade. Our study aimed to establish whether variation in the GYPB*S/s alleles influences susceptibility to infection with P. falciparum in the admixed population of Brazil. Methods Two groups of Brazilian Amazonians from Porto Velho were studied: P. falciparum infected individuals (cases); and uninfected individuals who were born and/or have lived in the same endemic region for over ten years, were exposed to infection but have not had malaria over the study period (controls). The GPB Ss phenotype and GYPB*S/s alleles were determined by standard methods. Sixty two Ancestry Informative Markers were genotyped on each individual to estimate admixture and control its potential effect on the association between frequency of GYPB*S and malaria infection. Results GYPB*S is associated with host susceptibility to infection with P. falciparum; GYPB*S/GYPB*S and GYPB*S/GYPB*s were significantly more prevalent in the in the P. falciparum infected individuals than in the controls (69.87% vs. 49.75%; P<0.02). Moreover, population genetics tests applied on the GYPB exon sequencing data suggest that natural selection shaped the observed pattern of nucleotide diversity. Conclusion Epidemiological and evolutionary approaches suggest an important role for the GPB receptor in RBC invasion by P. falciparum in Brazilian Amazons. Moreover, an increased susceptibility to infection by this parasite is

  10. Population genetics of GYPB and association study between GYPB*S/s polymorphism and susceptibility to P. falciparum infection in the Brazilian Amazon.

    Directory of Open Access Journals (Sweden)

    Eduardo Tarazona-Santos

    Full Text Available BACKGROUND: Merozoites of Plasmodium falciparum invade through several pathways using different RBC receptors. Field isolates appear to use a greater variability of these receptors than laboratory isolates. Brazilian field isolates were shown to mostly utilize glycophorin A-independent invasion pathways via glycophorin B (GPB and/or other receptors. The Brazilian population exhibits extensive polymorphism in blood group antigens, however, no studies have been done to relate the prevalence of the antigens that function as receptors for P. falciparum and the ability of the parasite to invade. Our study aimed to establish whether variation in the GYPB*S/s alleles influences susceptibility to infection with P. falciparum in the admixed population of Brazil. METHODS: Two groups of Brazilian Amazonians from Porto Velho were studied: P. falciparum infected individuals (cases; and uninfected individuals who were born and/or have lived in the same endemic region for over ten years, were exposed to infection but have not had malaria over the study period (controls. The GPB Ss phenotype and GYPB*S/s alleles were determined by standard methods. Sixty two Ancestry Informative Markers were genotyped on each individual to estimate admixture and control its potential effect on the association between frequency of GYPB*S and malaria infection. RESULTS: GYPB*S is associated with host susceptibility to infection with P. falciparum; GYPB*S/GYPB*S and GYPB*S/GYPB*s were significantly more prevalent in the in the P. falciparum infected individuals than in the controls (69.87% vs. 49.75%; P<0.02. Moreover, population genetics tests applied on the GYPB exon sequencing data suggest that natural selection shaped the observed pattern of nucleotide diversity. CONCLUSION: Epidemiological and evolutionary approaches suggest an important role for the GPB receptor in RBC invasion by P. falciparum in Brazilian Amazons. Moreover, an increased susceptibility to infection by this

  11. Negative Drift in Populations

    DEFF Research Database (Denmark)

    Lehre, Per Kristian

    2011-01-01

    An important step in gaining a better understanding of the stochastic dynamics of evolving populations, is the development of appropriate analytical tools. We present a new drift theorem for populations that allows properties of their long-term behaviour, e.g. the runtime of evolutionary algorithms...

  12. POPULATION TURNING POINT

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Latest census shows structural imbalance of population has replaced explosive growth to become China’s top challenge China’s population grew by less than 1 percent annually in the last decade,but it still remains the world’s largest at 1.37 billion people,according to results

  13. Ecology and Population

    Science.gov (United States)

    Hawley, Amos H.

    1973-01-01

    Author suggests that study of population growth is not a field of study only for ecologists. Population growth is related with social sciences in the nature of its process and future consequences. Broader, comprehensive approaches to this problem will be useful. (PS)

  14. Population Education Regional News.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1985

    1985-01-01

    Discusses: (1) a comparative study on managing population education programs; (2) a South Pacific workshop in which training materials on sex education, family life education, and nutrition-oriented mixed gardening were developed; and (3) a workshop on evaluative research, the focus of national population education programs in Asia. (JN)

  15. Population Education Country Programmes.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Highlights various population education programs in Afghanistan, China, India, Malaysia, Sri Lanka, and Vietnam. Also describes population education programs at primary and secondary levels in Thailand, curriculum and instructional materials development in this country, and teaching units and curriculum outlines developed from a workshop for…

  16. The Population Activist's Handbook.

    Science.gov (United States)

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  17. The Population Activist's Handbook.

    Science.gov (United States)

    Population Inst., Washington, DC.

    This handbook is a guide to effective action strategies on dealing with overpopulation. Divided into five sections, the book outlines programs, suggests references, and lists resources that are helpful for thinking and for planning action on population issues. Section one focuses on strategies to change the current population policy choices made…

  18. Befolkningsudviklingen (Population Development)

    DEFF Research Database (Denmark)

    Nørgaard, Jørgen

    2010-01-01

    The article takes the 1972 report, The Limits to Growth as its starting point, briefly explaining the Systam Dynamics model used for the report's analyses. Focus is on the important role of population. The simple model of I = PxAxT, where I is the environmental Impact, P population...

  19. Dimensions of Philippine population.

    Science.gov (United States)

    1980-01-01

    Major findings of a 2 1/2 year research program on Philippine population are presented. The population situation is described with respect to fertility, mortality, life expectancy, migration, labor force, and family formation. Policy recommendations addressing problems in each of these areas are made.

  20. Understanding Population Projections.

    Science.gov (United States)

    Haub, Carl

    1987-01-01

    Population projections are "what if" computational exercises. Given selected assumptions about future trends in fertility, mortality, and migration, population trends can be projected. Government and business planners need this information, and they also require enough time to put facilities in place to meet future needs. Everyone benefits from a…

  1. Population dynamics of reindeer

    Directory of Open Access Journals (Sweden)

    L. M. Baskin

    1990-09-01

    Full Text Available Five types of reindeer populations are distinguished in terms of population dynamics, population density, social structure and migration distance. Differences in the biological rhythms of the populations result in calving occuring 20 days before snow melting in all populations as well as maximal utilization by the deer of young green vegetation in summer. The growth of antlers may serve as a regulatior of biological rhytms. Populations differ in the level of social motivation. Formation of groups of not less than 30-35 animals ensures cooperative protection from insects and management of the group by man. The fidelity to the calving sites, summer ranges and constant migration routes is based on the common orientation reactions of the animals and social attraction. The direction and migration routes are detemined by obligate learning. The dynamics of populations depends on the fertility of 2 and 3 year old females which is determined by feeding conditions in summer and the activity of males during the rut. Migration plays an important role in the population dynamics.

  2. Diversity of Poissonian populations

    Science.gov (United States)

    Eliazar, Iddo I.; Sokolov, Igor M.

    2010-01-01

    Populations represented by collections of points scattered randomly on the real line are ubiquitous in science and engineering. The statistical modeling of such populations leads naturally to Poissonian populations—Poisson processes on the real line with a distinguished maximal point. Poissonian populations are infinite objects underlying key issues in statistical physics, probability theory, and random fractals. Due to their infiniteness, measuring the diversity of Poissonian populations depends on the lower-bound cut-off applied. This research characterizes the classes of Poissonian populations whose diversities are invariant with respect to the cut-off level applied and establishes an elemental connection between these classes and extreme-value theory. The measures of diversity considered are variance and dispersion, Simpson’s index and inverse participation ratio, Shannon’s entropy and Rényi’s entropy, and Gini’s index.

  3. Cairo: repackaging population control.

    Science.gov (United States)

    Simons, H

    1995-01-01

    Aid agencies, charities, and other nongovernmental organizations once denounced population control programs as racist interference in the third world. Yet, at the United Nations Conference on Population and Development in Cairo last September, these same organizations endorsed very similar ideas. The U.N. can now claim that even its fiercest critics not only have muted their criticism of population control programs but now positively endorse them. Over the last 30 years, population control has been consciously repackaged by the U.S. establishment. The image of population control has changed from being overtly anti-third world to being about giving the people of the third world--especially women--basic rights in family planning. Wrapped up in the language of women's empowerment and environmentalism, the establishment's old arguments about there being too many nonwhite babies in the world, have, unfortunately, won the day.

  4. Characterization of a likelihood based method and effects of markers informativeness in evaluation of admixture and population group assignment

    Directory of Open Access Journals (Sweden)

    Kranzler Henry R

    2005-10-01

    Full Text Available Abstract Background Detection and evaluation of population stratification are crucial issues in the conduct of genetic association studies. Statistical approaches useful for understanding these issues have been proposed; these methods rely on information gained from genotyping sets of markers that reflect population ancestry. Before using these methods, a set of markers informative for differentiating population genetic substructure (PGS is necessary. We have previously evaluated the performance of a Bayesian clustering method implemented in the software STRUCTURE in detecting PGS with a particular informative marker set. In this study, we implemented a likelihood based method (LBM in evaluating the informativeness of the same selected marker panel, with respect to assessing potential for stratification in samples of European Americans (EAs and African Americans (AAs, that are known to be admixed. LBM calculates the probability of a set of genotypes based on observations in a reference population with known specific allele frequencies for each marker, assuming Hardy Weinberg equilibrium (HWE for each marker and linkage equilibrium among markers. Results In EAs, the assignment accuracy by LBM exceeded 99% using the most efficient marker FY, and reached perfect assignment accuracy using the 10 most efficient markers excluding FY. In AAs, the assignment accuracy reached 96.4% using FY, and >95% when using at least the 9 most efficient markers. The comparison of the observed and reference allele frequencies (which were derived from previous publications and public databases shows that allele frequencies observed in EAs matched the reference group more accurately than allele frequencies observed in AAs. As a result, the LBM performed better in EAs than AAs, as might be expected given the dependence of LBMs on prior knowledge of allele frequencies. Performance was not dependent on sample size. Conclusion The performance of the LBM depends on the

  5. Global population growth.

    Science.gov (United States)

    Langmore, J

    1992-07-01

    The global population passed 5 billion in 1987. In the year 2000 the world's population will be more than 6 billion, increasing by 90-100 million each year. About 95% of future demographic growth will take place in developing countries. The number of school age children is projected to increase from 940 million in 1980 to 1280 million by the year 2000. Under current labor force growth projections in developing countries, around 1.6 billion new jobs will have to be created between 1980 and 2025, with nearly 1 billion of them in Asia. Population often increases at a more rapid rate than agricultural growth. Food production per capita has declined in 70 developing countries. Much of the projected population increase will take place in environmentally fragile regions of the developing world. Population pressures contribute to deforestation, desertification, and scarcity of clean water. The United Nations Population Fund has estimated that in Asia over 43% of women not using family planning would like to postpone, space, or limit their childbearing. Over half of the world's couples of reproductive age are now using contraception. Family planning to postpone the first birth and to eliminate late child bearing would reduce both child loss and maternal illness and death. Both infant and maternal mortality are greater with higher order births. Reducing average family size is an effective way of reducing infant and maternal mortality. The World Bank has given high priority to population assistance, with large programs in Bangladesh, Egypt, India, Indonesia, the Philippines, and Thailand. Population assistance provided by the Australian International Development Assistance Bureau totaled about $4.5 million during 1989-90 and is expected to be about $8 million during 1991-92. Australia should increase the proportion of its development assistance budget devoted to population, and family planning programs should increase to around $26 million in line with other major donors.

  6. Constructing populations in biobanking

    DEFF Research Database (Denmark)

    Tupasela, Aaro; Snell, Karoliina; Cañada, Jose a.

    2015-01-01

    This article poses the question of whether biobanking practices and standards are giving rise to the construction of populations from which various biobanking initiatives increasingly draw on for legitimacy? We argue that although recent biobanking policies encourage various forms of engagement...... to the construction of populations, whereby specific nationalities, communities, societies, patient groups and political systems become imbued or bio-objectified with particular characteristics, such as compliant, distant, positive, commercialized or authoritarian. This bio-objectification process is problematic...... in relation to policy aspirations ascribed to biobanking engagement since it gives rise to reified notions of different populations....

  7. [Trends in population aging].

    Science.gov (United States)

    Valkovics, E

    1990-11-01

    The age structure of the world population between 1950 and 1985 is analyzed according to changes in fertility, mortality, and international migration in developing and developed countries. "Relying on the results of the medium scenario of the population forecasts prepared by the U.N. Division of International Economic and Social Affairs, the author demonstrates that aging of the world population will become a global phenomenon, characteristic of every region and county of the world, between 1985 and 2025." (SUMMARY IN ENG AND RUS)

  8. Predation and caribou populations

    Directory of Open Access Journals (Sweden)

    Dale R. Seip

    1991-10-01

    Full Text Available Predation, especially wolf (Canis lupus predation, limits many North American caribou (Rangifer tarandus populations below the density that food resources could sustain. The impact of predation depends on the parameters for the functional and numerical response of the wolves, relative to the potential annual increment of the caribou population. Differences in predator-avoidance strategies largely explain the major differences in caribou densities that occur naturally in North America. Caribou migrations that spatially separate caribou from wolves allow relatively high densities of caribou to survive. Non-migratory caribou that live in areas where wolf populations are sustained by alternate prey can be eliminated by wolf predation.

  9. The population threat.

    Science.gov (United States)

    Teitelbaum, M S

    1992-01-01

    Commentary is provided on the challenges faced by the new Clinton administration in formulating US key foreign policy initiatives. There is an urgent need to provide balanced and effective foreign aid for reducing high fertility rates in the developing world. There is also a need to effectively monitor the large migrations of populations. Over the past 10 years, the US has not been actively practicing world leadership on population issues. 3 changes in 1993 give impetus to redirect foreign policy: 1) the waning influence of fringe groups who controlled population issues; 2) the campaign promises to restore UN population stabilization programs; and 3) the evidence from the Persian Gulf and Yugoslavia that demographic issues require planning and assessment. Global population growth has been concentrated in the past 40 years, in part due to mortality declines and sustained high fertility. Of significance is the rapidness and momentum of growth. A high percentage are and will be children. Urban population is also growing rapidly in high fertility countries. Countries with high fertility and significant rural-to-urban migration also have large international migrations. The evolution of policy since the 1950s, which for the most part ignored population issues, is discussed. The American debates have been charged with emotionalism: about human sexuality, legitimacy of voluntary fertility control, the role and status of women and men, abortion, intergenerational transfer of obligations, ethnic solidarity and the sovereignty of national borders, and the proper roles of the state versus the marketplace. There have been over 200 years of ideological argument over population issues. The Malthusian argument was that large population size did not increase prosperity, and growth should be limited. The Marxist-Leninist position was that contraception was Malthusian, abortion was a woman's right, and population growth was neutral. By late 1970 the Chinese Maoists adopted the moral

  10. Pre Conference Hazardous Materials Workshop, West/East Coast Safety Conference, held 3-4 October/31 October - 1 November 1981,

    Science.gov (United States)

    1981-01-01

    the date of plata , the enactment of the Used Oil Rc.,clirig Act of 1980 "(2) The plan shall, in accordance with section may be amended, at the option...D.C. 20036 Hilo , Hawaii Ph: (202) 797-5425 Honolulu, Hawaii R REFERENCE DATA SI DATA SOURCES HAZARDOUS MATERIALS I1. ASSOCIATIONS AND GOVERNMENT

  11. 西气东输二线用RMD根焊技术%RMD root welding technology of West-East Gas Transmission Pipeline Project Ⅱ

    Institute of Scientific and Technical Information of China (English)

    靳海成; 王俊红; 李广民; 黄志辉

    2009-01-01

    介绍了RMD设备的特点、根焊技术的参数调节、应用参数、易出气孔的原因、焊接工艺和根焊接头分析等.RMD作为一种精确控制下的短路过度技术.能通过检测短路电流发生时间及时改变焊接电流和电压,是一种动态控制技术,可以精确控制熔池.结果表明,该设备操作简便、焊接速度快、根部成形好,对焊接飞溅、热影响区以及平稳过渡的优化都明显强于传统的根焊,在管道全位置焊接中具有较好的应用前景.

  12. 中西文化的冲突与交融%The Collision and Integration of the West-East Culture

    Institute of Scientific and Technical Information of China (English)

    黄爱琼; 罗雨青

    2011-01-01

    全球化趋势不断加快,国家和地区间不同文化之间的频繁交流。毋庸置疑,东西方文化交流不可避免地会产生碰撞与融合。此外,东西方文化应该互相交流,并融合在一起,以促进不同的文化间进行有效地沟通,推动不同文化之间的相互发展。跨文化交际这个术语就应时而生了。%The trend of globalization has been increasingly accelerating frequent cultural exchange among countries in the world.Undoubtedly,the East cultures would have inevitable collision and integration with the West cultures;in addition,the West exchange their cultures with the East so as to promote effective communication and development.The term of Intercultural communication is therefore born.

  13. Parallel grid population

    Science.gov (United States)

    Wald, Ingo; Ize, Santiago

    2015-07-28

    Parallel population of a grid with a plurality of objects using a plurality of processors. One example embodiment is a method for parallel population of a grid with a plurality of objects using a plurality of processors. The method includes a first act of dividing a grid into n distinct grid portions, where n is the number of processors available for populating the grid. The method also includes acts of dividing a plurality of objects into n distinct sets of objects, assigning a distinct set of objects to each processor such that each processor determines by which distinct grid portion(s) each object in its distinct set of objects is at least partially bounded, and assigning a distinct grid portion to each processor such that each processor populates its distinct grid portion with any objects that were previously determined to be at least partially bounded by its distinct grid portion.

  14. Populated Places of Iowa

    Data.gov (United States)

    Iowa State University GIS Support and Research Facility — This coverage contains points that represent populated places, ie. cities, towns, villages or any other named place where people live. The coverage was developed...

  15. Market Squid Population Dynamics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset contains population dynamics data on paralarvae, juvenile and adult market squid collected off California and the US Pacific Northwest. These data were...

  16. AMPHIBIAN POPULATION DYNAMICS

    Science.gov (United States)

    Agriculture has contributed to loss of vertebrate biodiversity in many regions, including the U.S. Corn Belt. Amphibian populations, in particular, have experienced widespread and often inexplicable declines, range reductions, and extinctions. However, few attempts have been made...

  17. County Population Vulnerability

    Data.gov (United States)

    City and County of Durham, North Carolina — This layer summarizes the social vulnerability index for populations within each county in the United States at scales 1:3m and below. It answers the question...

  18. Modeling Honey Bee Populations.

    Directory of Open Access Journals (Sweden)

    David J Torres

    Full Text Available Eusocial honey bee populations (Apis mellifera employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population.

  19. Modeling Honey Bee Populations

    Science.gov (United States)

    Torres, David J.; Ricoy, Ulises M.; Roybal, Shanae

    2015-01-01

    Eusocial honey bee populations (Apis mellifera) employ an age stratification organization of egg, larvae, pupae, hive bees and foraging bees. Understanding the recent decline in honey bee colonies hinges on understanding the factors that impact each of these different age castes. We first perform an analysis of steady state bee populations given mortality rates within each bee caste and find that the honey bee colony is highly susceptible to hive and pupae mortality rates. Subsequently, we study transient bee population dynamics by building upon the modeling foundation established by Schmickl and Crailsheim and Khoury et al. Our transient model based on differential equations accounts for the effects of pheromones in slowing the maturation of hive bees to foraging bees, the increased mortality of larvae in the absence of sufficient hive bees, and the effects of food scarcity. We also conduct sensitivity studies and show the effects of parameter variations on the colony population. PMID:26148010

  20. Waterfowl breeding population survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Waterfowl breeding population surveys have been completed annually on the Arctic Coastal Plain of Alaska since 1986. Methods for the 2011 Arctic Coastal Plain...

  1. Waterfowl breeding population survey

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Waterfowl breeding population surveys have been completed annually on the Arctic Coastal Plain of Alaska since 1986. Methods for the 2010 Arctic Coastal Plain...

  2. Bridged Race Population Estimates

    Data.gov (United States)

    U.S. Department of Health & Human Services — Population estimates from "bridging" the 31 race categories used in Census 2000, as specified in the 1997 Office of Management and Budget (OMB) race and ethnicity...

  3. Association with Spontaneous Hepatitis C Viral Clearance and Genetic Differentiation of IL28B/IFNL4 Haplotypes in Populations from Mexico

    Science.gov (United States)

    Gonzalez-Aldaco, Karina; Rebello Pinho, João R.; Roman, Sonia; Gleyzer, Ketti; Fierro, Nora A.; Oyakawa, Leticia; Ramos-Lopez, Omar; Ferraz Santana, Rubia A.; Sitnik, Roberta; Panduro, Arturo

    2016-01-01

    Aim To analyze the genetic heterogeneity of the Amerindian and admixed population (Mestizos) based on the IL28B (rs12979860, rs8099917) and IFNL4 (rs368234815) haplotypes, and their association with spontaneous clearance (SC) and liver damage in patients with hepatitis C infection from West Mexico. Methods A total of 711 subjects from West Mexico (181 Amerindians and 530 Mestizos) were studied for the prevalence of IL28B (rs12979860C/T, rs8099917G/T) and IFNL4 (rs368234815∆G/TT) genotypes. A case-control study was performed in 234 treatment-naïve HCV Mestizos (149 chronic hepatitis C and 85 with SC) for the association of haplotypes with SC and liver damage. A real-time PCR assay was used for genotyping, and transitional elastography staged liver damage. Results Significant Fst-values indicated differentiation between the studied populations. The frequencies of the protective C, T, TT alleles were significantly lower in the Amerindians than in Mestizos (p<0.05). The r2 measure of linkage disequilibrium was significant for all variants and the T/G/ΔG risk haplotype predominated in Amerindians and secondly in Mestizos. The protective C/T/TT haplotype was associated with SC (OR = 0.46, 95% IC 0.22–0.95, p = 0.03) and less liver damage (OR = 0.32, 95% IC 0.10–0.97, p = 0.04) in chronic patients. The Structure software analysis demonstrated no significant differences in ancestry among SC and chronic patients. Conclusions West Mexico´s population is genetically heterogeneous at the IL28B/IFNL4 polymorphisms. The T/G/ΔG high-risk haplotype predominated in Amerindians and the beneficial alternative haplotype in Mestizos. The C/T/TT haplotype was associated with SC and less liver damage in chronically infected Mestizo patients. PMID:26741362

  4. EDUCATION AND ROMA POPULATION

    Directory of Open Access Journals (Sweden)

    Ana Asensio Belenguer

    2016-07-01

    Full Text Available This article deals with Education and the Roma Population. It presents an approach to schooling of Romani children since its outset in the city of Zaragoza (Spain. It analyzes the current status as presented by the Strategy for Social Inclusion of this people 2012-2020, and collects, from various sources, the fact that education remains a pending challenge for Roma Population. Measures to be taken by the educational community from a gender and inclusive perspective are proposed.

  5. Population Density Modeling Tool

    Science.gov (United States)

    2014-02-05

    194 POPULATION DENSITY MODELING TOOL by Davy Andrew Michael Knott David Burke 26 June 2012 Distribution...MARYLAND NAWCADPAX/TR-2012/194 26 June 2012 POPULATION DENSITY MODELING TOOL by Davy Andrew Michael Knott David Burke...Density Modeling Tool 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Davy Andrew Michael Knott David Burke 5d. PROJECT NUMBER

  6. Iraqi Population Displacement Analysis

    Science.gov (United States)

    2016-11-01

    CENTER FOR ARMY ANALYSIS 6001 GOETHALS ROAD FORT BELVOIR, VA 22060-5230 CAA-2015098 IRAQI POPULATION DISPLACEMENT ANALYSIS NOVEMBER 2016...designated by other official documentation. Comments or suggestions should be addressed to: Director Center for Army Analysis ATTN: CSCA-OA...CONTRACT NUMBER Iraqi Population Displacement Analysis PDMC 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) 5d. PROJECT NUMBER Ms

  7. Exploding Increase of Population

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J.H. [Sunmoon University, Chonan (Korea)

    2002-03-01

    Until 1650, the population of the world did not increase properly. According to studies of the demography, the annual increase rate of the world population during 2500 years, from 850 B.C. to 1650 A.D., was just 0.07%. Currently, however, the world population, which has exceptionally rapidly increased from 1900, is more than 6 billion as of 2000. After World War II, especially, the increase rate of the population has risen to about 1.8%, so we can use the word, explosion of the population. The explosion of the population accompanies the increase of energy consumption. The energy production of every year cannot sufficiently meet the energy demand, so we can face the grand energy crisis someday. The date might be a someday after 2020. According to the future forecasting of Shell, one of the majors, the peak of oil supply will be between 2015 and 2020. Unless the alternative energy is developed, the whole world will suffer the serious oil crisis.

  8. Normative population theory.

    Science.gov (United States)

    Cowen, T

    1989-01-01

    This article finds utilitarian and contractarian approaches to solving the problem of optimal population unacceptable. The principles of utility refer to the best population as the one which contains the greatest sum of utility or the one with the highest average utility. Yet Parfits's repugnant conclusion states that these can imply a very large population at a very low standard of living. Cowen's Methuselah's Paradox says that for any possible happy and meaningful life, we can imagine another, much longer life which demonstrates the absurdity of the utility principles. Lewis argues for a conception of well being based upon choices over whole irreducible states of affairs, i.e., an ordinal concept of value. The contractarian approach assumes that we would rationally choose what type of life we were to live if the choice were made without anyone knowing his particular standing in the world--the veil of ignorance. This requires the individuals to choose on the basis of self interest, but gives too much weight to the individuals actually being born. The most promising population theory appears to be the ideal participant method. Simply stated the optimal population is what an individual would prefer if he had to sequentially live out each life in his choice. Further, this method may be able to reduce the difficulties with evaluating alternate populations to the common problem of aggregating disparate preferences.

  9. First China Population Award.

    Science.gov (United States)

    1993-10-01

    The China Population Award is given every two years for family planning implementation, science, and technology, and honorary achievements. The winners for the First China Population Award were as follows: Mr. Zhao Zhihao, governor of Shandong province; Mme. Shang Dewei, retired from the Shanghai family planning committee; Mme. Cui Peihua, director of the Nanche Village, Shidao Town, Rongcheng City, Shandong Province, Family Planning Office; Mme. Xu Aiguang, director of Zhejiang Family Planning Committee; Mr. Ye Wenshi, secretary of Guanghan City Party Committee, Sichuan province; Mr. Zhang Zhiyuan, president of Liaoning Family Planning Association; Mme. Shou Haizhen, director of Jiangsu Family Planning Committee for family planning implementation. Mme. Yan Renying, vice president of the China Family Planning Association, Mr. Wu Jieping, vice president of the China Family Planning Association, and Mr. Lie Zheng (deceased), former president of the Population Association of China received prized for achievements in science and technology. Mr. Ma Yinchu (decreased) honorary president of Peking University, received an honorary prize for his creative views on the contradictions between rapid population growth and increased capital wealth. He recommended population control and improvement in quality of human resources. He recommended the practice of deferred marriage and other solutions to China's population problems. As an ultra-leftist, he was severely criticized, but redeemed in 1981 shortly before he died. The science and technology awards went to Mr. Zheng who established the first population research institute and suggested that reproduction be in balance with material resources. Mr. Jieping was a medical specialist and contributed to research on male birth control. Mme. Renying, as an obstetrician and gynecologist, researched use of prostaglandin injections for ending early pregnancy and reversible female sterilization. She was active in efforts of prevention of

  10. Global pharmacogenomics: distribution of CYP3A5 polymorphisms and phenotypes in the Brazilian population.

    Directory of Open Access Journals (Sweden)

    Guilherme Suarez-Kurtz

    diversity of the population. The relevance of this work extrapolates the Brazilian borders, and extends to other admixed peoples of the Americas, with ancestral roots in Europe, Africa and the American continent.

  11. Population pressure rising.

    Science.gov (United States)

    1994-08-01

    Even though the ESCAP region has been successful in slowing population growth, Asia will account for half of the global population increase every year, or about 1 billion persons in the next quarter century, according to a new report by the Asian Development Bank (ADB). That report, entitled "Population Policy Paper," states that Asia will be the global center of population aging largely because of big increases in the number of persons over the age of 65 in China, Japan and the region's newly industrializing economies. "By the year 2000, 86% of the world's aged will be in the Asia-Pacific region and by the year 2025 there are projected to be 687 million persons over the age of 65 in the region, placing unprecedented strains on economic and social systems far beyond what traditional extended family networks can absorb," the paper says. But the report also considers other aspects of overall population increase. "The prospect of an additional billion or so people in Asia over the next 25 years is daunting, since the implications for poverty, economic growth, unemployment and environmental quality are immense," it adds. The region's economies will have to scramble to generate jobs and livelihoods for tens of millions of young people for the next several decades. Rural-to-urban migration trends threaten the collapse of urban infrastructure, with the social tensions and political instability that such troubles bring, the report states.

  12. Frequency Population Growth Rate

    Directory of Open Access Journals (Sweden)

    Nouralah Salehi Asfiji

    2012-10-01

    Full Text Available The Solow growth model assumes that labor force grows exponentially. That is not a realistic assumption. In generalized logistic equations that describes more accurately population growth. Economic growth is not a smooth process. Real GDP has fluctuations in the growth rate. We call these fluctuations business cycles. Business cycle theory came about from the failures of classical economics in being able to illuminate on the causes of the Great Depression. The logistic growth model to explain changes in population growth rates are not. In this paper a new analysis of the population growth rate in the frequency space is described with mathematical logic and economic reasoning, so that, firstly, to a higher level of capital per capita, or at least equal to the Solow growth model reaches Second, the limits of saturation (Carrying-Capacity is not, and ultimately, population growth rates have an impact on long-term per capita amounts. The initial classic assumption is changed in this article based on the available frequencies in the population growth equation.

  13. Asymetric Pavlovian Populations

    CERN Document Server

    Bournez, Olivier; Cohen, Johanne; Koegler, Xavier; Rabie, Mikael

    2011-01-01

    Population protocols have been introduced by Angluin et al. as a model of networks consisting of very limited mobile agents that interact in pairs but with no control over their own movement. A collection of anonymous agents, modeled by finite automata, interact pairwise according to some rules that update their states. Predicates on the initial configurations that can be computed by such protocols have been characterized as semi-linear predicates. In an orthogonal way, several distributed systems have been termed in literature as being realizations of games in the sense of game theory. We investigate under which conditions population protocols, or more generally pairwise interaction rules, correspond to games. We show that restricting to asymetric games is not really a restric- tion: all predicates computable by protocols can actually be computed by protocols corresponding to games, i.e. any semi-linear predicate can be computed by a Pavlovian population multi-protocol.

  14. Quenched effective population size

    CERN Document Server

    Sagitov, Serik; Vatutin, Vladimir

    2010-01-01

    We study the genealogy of a geographically - or otherwise - structured version of the Wright-Fisher population model with fast migration. The new feature is that migration probabilities may change in a random fashion. Applying Takahashi's results on Markov chains with random transition matrices, we establish convergence to the Kingman coalescent, as the population size goes to infinity. This brings a novel formula for the coalescent effective population size (EPS). We call it a quenched EPS to emphasize the key feature of our model - random environment. The quenched EPS is compared with an annealed (mean-field) EPS which describes the case of constant migration probabilities obtained by averaging the random migration probabilities over possible environments.

  15. Population options for Australia.

    Science.gov (United States)

    Ruddock, P

    1999-01-01

    In an address to the Australian Population Association Biennial Conference during October 1998, the Immigration and Multicultural Affairs Minister Philip Ruddock argued that neither the zero net overseas migration policy nor the massive boost in immigration are in the national interest of Australia. Environmental groups generally view that Australia should adopt a policy of zero net overseas migration. On the other hand, business and industry bodies consider that a substantial increase in the migration intake is needed in order to increase economic growth and to reduce the impact of an aging population. Moreover, some are concerned about population targets reaching up to 50 million in 50 years time. Thus, management of immigration policy is a difficult balancing act between competing objectives. The Minister concluded that their immigration program must operate on a totally global and nondiscriminatory basis regarding matters such as race, religion, color, and ethnic origin.

  16. National population policy.

    Science.gov (United States)

    Singh, K

    1976-01-01

    Dr. Singh emphasized that the Indian government realized radical measures were necessary to control the country's staggering population explosion. With only 2.4% of the world's area, it has 15% of the world's population, increasing at a rate of over 1 million/month. Suggested measures include raising the age of marriage, freezing state representation until 2001 to increase the states' interest in population problems, increasing female literacy, increasing monetary compensation for voluntary sterilization, providing group incentives, using voluntary organizations, and generally changing the urban elitist approach of the past into more imaginative rural-oriented attitudes. States with adequate facilities could institute compulsory sterilization after 3 children, uniformly applicable to state citizens.

  17. Population and Climate Change

    Science.gov (United States)

    O'Neill, Brian C.; Landis MacKellar, F.; Lutz, Wolfgang

    2000-11-01

    Population and Climate Change provides the first systematic in-depth treatment of links between two major themes of the 21st century: population growth (and associated demographic trends such as aging) and climate change. It is written by a multidisciplinary team of authors from the International Institute for Applied Systems Analysis who integrate both natural science and social science perspectives in a way that is comprehensible to members of both communities. The book will be of primary interest to researchers in the fields of climate change, demography, and economics. It will also be useful to policy-makers and NGOs dealing with issues of population dynamics and climate change, and to teachers and students in courses such as environmental studies, demography, climatology, economics, earth systems science, and international relations.

  18. National population policy.

    Science.gov (United States)

    1983-01-26

    India evolved a comprehensive national population policy in April 1967. The primary assumption behind this policy was that the population explosion was an offshoot of poverty and must be dealt with as a part of an overall design for a better life. Clear demographic goals were defined, and several programs were initiated as part of the policy in an effort to integrate family planning with the overall strategy of socioeconomic development. The following are among the more important features of the 1976 national population policy: 1) increase the marriage age from 15-18 years for girls and from 18 to 21 years for boys; 2) freeze the population figures at the 1971 level until the year 2001 for purposes of representation in the national parliament as well as for allocation of central assistance, devolution of taxes, and so forth to the States; 3) more attention to the education of girls; 4) a proper place for population education in the total system of education; 5) involvement of all ministries/departments of government in the family planning program; 6) increase in monetary compensation for sterilization; 7) institution of group awards as incentives for various organizations and bodies representing the people at local levels; 8) the intimate association of voluntary organizations with the implementation of the program; 9) more attention to research; and 10) greater use of motivational media, particularly in rural areas, for increasing acceptance of family planning. According to Indira Gandhi, the objective is not simply to curb population growth but to have happier and healthier families, which, in India's circumstances, means smaller families. In the 1st 5-year plan (1951-56) India's outlay on family planning (Rs. in crores) was 0.65. It had increased to 1010.00 by the 6th 5-year plan (1980-85).

  19. Population and development.

    Science.gov (United States)

    Pavlik, Z

    1995-01-01

    During the Paleolithic period, 10,000-100,000 people lived on the earth; their number exceeded 1 million at the beginning of the Neolithic period, reached 10 million during the Bronze Age, 100 million at the beginning of the Iron Age, 1 billion at the beginning of the 19th century, and 5.7 billion in 1995. The estimated global population will be 10 billion by the middle of the 21st century and is expected to stabilize at around 10-12 billion subsequently. Increased agricultural production helped bring about greater numbers of humanity and the advancement of society with a developing social hierarchy, although life expectancy was low at 22-28 years. In Europe, the Renaissance gradually evolved into the Industrial Revolution, and a demographic revolution accompanied this process. In some countries, population size increased more than five times. Eventually, mortality and fertility levels decreased and life expectancy increased. In Western civilization, increased individualism, secularization, compulsory school attendance, decreased agricultural population, emancipation of women, increased costs of raising children, and social and economic progress ensued. All this was preceded by 18th century conditions, when, in England, capital accumulation led to wealth on the one side and destitution on the other, giving rise to Malthus's famous theory. However, during the 19th century these social inequalities gradually evened out. After World War II, the question arose of whether the populations of other civilizations (Confucian, Japanese, Islamic, Hindu, Slavic-Orthodox, Latin American, and African) would also undergo a demographic transition and how soon. At any rate, developed country population size, as a percentage of global population, will drop from 22% to 13%, and that of Africa will increase from 12% to 26%, during the 21st century.

  20. Distance Learning for Special Populations

    Science.gov (United States)

    Bates, Rodger A.

    2012-01-01

    Distance education strategies for remotely deployed, highly mobile, or institutionalized populations are reviewed and critiqued. Specifically, asynchronous, offline responses for special military units, Native Americans on remote reservations, prison populations and other geographically, temporally or technologically isolated niche populations are…

  1. Nicaraguan population data on LDLR, GYPA, D7S8, HBGG, GC and HLA-DQA1 loci

    Directory of Open Access Journals (Sweden)

    Bernal Morera

    2001-12-01

    Full Text Available Nicaraguans have become the most numerous and fastest increasing minority in Costa Rica: at present they represent around 6 % of the total population of the country. We have analyzed the allele and genotype frequencies of six PCR-based genetic markers (LDLR, GYPA, HBGG, D7S8, GC, and HLA-DQA1 in 100 unrelated Nicaraguans living in Costa Rica. All loci studied were in Hardy-Weinberg equilibrium. Some statistical parameters of forensic interest were also calculated (h, PD and CE. Allele frequencies of the markers HLA-DQA1 and GYPAwere found to be significantly different between the populations of Nicaragua and Costa Rica. Nevertheless, genetic distances showed that Nicaragua is close to other Hispanic-admixed populations like those from Argentina, Chile, Colombia, Costa Rica, and USA Hispanics. The loci set was assessed to be useful for paternity testing and individual identification in the Nicaraguan population residing in Costa RicaLos nicaragüenses se han convertido en el grupo minoritario más numeroso y creciente en Costa Rica y en la actualidad representan alrededor del 6 % de la población total del país. Analizamos las frecuencias alélicas y genotípicas de seis marcadores genéticos (LDLR, GYPA, HBGG, D7S8, GC y HLA-DQA1 basados en la PCR en 100 nicaragüenses no emparentados, residentes en Costa Rica. Todos los loci estudiados cumplieron con el equilibrio de Hardy-Weinberg. También se calcularon algunos parámetros estadísticos de interés forense (h, PD y EC. Se encontró que las frecuencias alélicas de los marcadores HLA-DQA1 y GYPA presentan diferencias significativas entre las poblaciones de Nicaragua y Costa Rica. Sin embargo, el análisis de distancias genéticas mostró que la población de Nicaragua es cercana a otras de origen hispano mestizo como las poblaciones de Argentina, Chile, Colombia, Costa Rica y los hispanos de Estados Unidos. Este conjunto de loci fue validado como útil para la realización de pruebas de

  2. Populism in Latin America

    Science.gov (United States)

    2009-03-20

    a profound constitutional reform through the National Congress. The goal is always to adapt the democratic system and subordinate it to the personal...to the democratic system of a country that has become immersed in populism. The other inevitably involves 21 control of the media, the military

  3. Refining population health comparisons

    DEFF Research Database (Denmark)

    Hussain, M. Azhar; Jørgensen, Mette Møller; Østerdal, Lars Peter Raahave

    2016-01-01

    How to determine if a population group has better overall (multidimensional) health status than another is a central question in the health and social sciences. We apply a multidimensional first order dominance concept that does not rely on assumptions about the relative importance of each...

  4. Constructing populations in biobanking

    DEFF Research Database (Denmark)

    Tupasela, Aaro; Snell, Karoliina; Cañada, Jose a.

    2015-01-01

    This article poses the question of whether biobanking practices and standards are giving rise to the construction of populations from which various biobanking initiatives increasingly draw on for legitimacy? We argue that although recent biobanking policies encourage various forms of engagement w...

  5. Africa population dynamics

    NARCIS (Netherlands)

    Akinyoade, A.; Damen, J.C.M.; Dietz, A.J.; Kilama, B.; Omme, van G.

    2014-01-01

    Africa's population has grown extremely rapidly over the last fifty years from 289 million inhabitants in 1961 to more than 1 billion today. This is a growth rate of 350% in just half a century and the number of urban residents has increased even more quickly: from 65 million in 1960 to 460 million

  6. Relics: penguin population programs.

    Science.gov (United States)

    Sun, L; Xie, Z

    2001-01-01

    What has been responsible for the increase in Chinstrap penguin populations during the past 40 years in maritime Antarctica? One view ascribes it to an increase in availability of their prey brought on by the decrease in baleen whale stocks. The contrary opinion, attributes it to environmental warming. This causes a gradual decrease in the frequency of cold years with extensive winter sea ice cover. A number of penguin monitoring programs are in progress and are expected to provide some answers to these questions. Unfortunately, it is not easy to distinguish natural variability from anthropogenic change since penguins are easily accessible predators of krill and the feeding range of the penguins has almost overlapped with the krill fishery in time and space in the last four decades. Therefore it is important to reconstruct the change of ancient penguin abundance and distribution in the absence of human activity. Many efforts have focused on surveying the abandoned penguin rookeries, but this method has not been able to give a continuous historical record of penguin populations. In several recent studies, ancient penguin excreta was scooped from the penguin relics in the sediments of the lake on penguin rookery, Ardley Island, maritime Antarctica. In these studies, penguin droppings or guano soil deposited in the lake and changes in sediment geochemistry have been used to calculate penguin population changes based upon the geochemical composition of the sediment core. The results suggest that climate change has a significant impact on penguin populations.

  7. China Population and Developmenl

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    The Cairo International Conference on Population and Development (ICPD) paid great attention to the sexual and reproductive health of adolescents. One of the top priorities of the ICPD Programme of Action is to provide adolescents with necessary sexual and reproductive health information and services, ensure their right to reproductive health education and services, and help them develop risk-free behaviours and healthy lifestyles.

  8. Charting Population Shifts

    Institute of Scientific and Technical Information of China (English)

    LI LI

    2010-01-01

    @@ China is updating its demographic information through its once-in-adecade population census.The latest database will be used as an important reference for the country to draft its development plan for the next five years and deal with social problems,such as an aging society and imbalanced gender ratio,according to experts.

  9. Adam Smith on population.

    Science.gov (United States)

    Spengler, J J

    1970-11-01

    Abstract Adam Smith dealt with questions of population mainly in his Wealth of Nations. His discussion falls roughly under five heads and reflects in considerable measure his image of the English economy. (1) A country's population capacity, given the average level of consumption, was conditioned by the stock of land, the skill with which it was cultivated, and the degree to which division of labour could be increased and thereby augment output for domestic use and sale in external markets. (2) Growth of population was essentially in response to growth of the demand for labour and served to increase division of labour. (3) The social mechanisms underlying elevation of the scale of living are touched upon, and in an optimistic spirit. (4) The distribution of a country's population responded to its progress in opulence, with the rate of this progress conditioned by the degree to which inappropriate (e.g. mercantilist) policies were avoided. (5) Smith dealt briefly with such matters as colonies, education, size of economy, environmental influences, and public policy, all of which he recognized as significant for the quantity and quality of a country's numbers.

  10. Population: fiction and fact.

    Science.gov (United States)

    1979-09-01

    This article was written to refute some common misunderstandings regarding worldwide population levels and worldwide nutrition levels. The world food supply is able to keep pace with high population growth levels. Worl food production currently meets world need; the problem is a distribution system which allocates food only to those who can pay rather than to those who need it. In many developing countries, the best agricultural lands are reserved for commercial crops rather than for subsistence crops. The U.S. food aid program does not help the most needy nations generally. The rate of world population growth is already slowing down. The desire for large families in developing countries is very often a realistic reaction to the prevailing economic system. Family planning programs will succeed. They will succeed even better in countries where general development planning is undertaken concurrently with family planning. Environmental problems are attributable to the consumption explosion in the rich countries rather than to the population explosion in the poor countries.

  11. Reconceptualization of Population Education.

    Science.gov (United States)

    Sikes, O. J.

    1993-01-01

    Discusses eight aspects of the reorganization of population education: (1) need for clear objectives; (2) emerging concerns about content; (3) prioritization of contents; (4) involvement of parents; (5) approaches to teaching; (6) teacher training; (7) evaluation issues; and (8) institutionalization. (MDH)

  12. Population and Development Issues.

    Science.gov (United States)

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  13. Population and Development Issues.

    Science.gov (United States)

    Cohen, Sharon; Garran, Christopher

    1998-01-01

    Describes a unit on demographics for a high school world-history course that addresses questions of uneven population growth and the "problem of global overpopulation." Provides a detailed outline of the two-day unit including unit and daily goals and objectives, daily activities and questions, and ideas for further student research. (DSK)

  14. Multiphoton coherent population oscillation

    CERN Document Server

    Sharypov, A V

    2014-01-01

    We study the bichromatic driving of a two-level system which displays long-lived coherent population oscillations (CPO). We show that under certain conditions, multiphoton parametric interaction leads to the appearance of CPO resonances at the subharmonic frequencies. In addition, in the region of the CPO resonances, there is strong parametric interaction between the weak sideband components of the electromagnetic field.

  15. Probabilistic population aging

    Science.gov (United States)

    2017-01-01

    We merge two methodologies, prospective measures of population aging and probabilistic population forecasts. We compare the speed of change and variability in forecasts of the old age dependency ratio and the prospective old age dependency ratio as well as the same comparison for the median age and the prospective median age. While conventional measures of population aging are computed on the basis of the number of years people have already lived, prospective measures are computed also taking account of the expected number of years they have left to live. Those remaining life expectancies change over time and differ from place to place. We compare the probabilistic distributions of the conventional and prospective measures using examples from China, Germany, Iran, and the United States. The changes over time and the variability of the prospective indicators are smaller than those that are observed in the conventional ones. A wide variety of new results emerge from the combination of methodologies. For example, for Germany, Iran, and the United States the likelihood that the prospective median age of the population in 2098 will be lower than it is today is close to 100 percent. PMID:28636675

  16. [Population trends and poverty].

    Science.gov (United States)

    Olmedo, C

    1998-04-01

    Implications of population growth in Ecuador for the quality of life of the poor population are analyzed. It is argued that if the gross national product (GNP) were to grow at a sustained annual rate of 5% or more, demographic trends would not present a significant obstacle to reducing poverty. National economic projections are for growth of only 2.5-3.5% annually. The continuing rapid growth of the poor population despite general slowing of demographic growth, the young age structure, the need for increased formal education to enable the poor to overcome their poverty, and the effect of unemployment on the dependency ratio will tend to hamper improvements in average productivity and per capita GNP. The need for spending on education, health, basic services, and housing will divert funds away from productive investment, generating a direct negative impact on economic growth. Over half of Ecuadorian children suffer from some degree of malnutrition, indicating that food production is inadequate to meet demand. The export-oriented agricultural policy and poor weather have led to a chronic shortage of basic foods. Progressive increase and diversification of agricultural production, along with maintenance of low prices and substantial increases in income levels and agricultural productivity, will be required if the entire population is to be fed adequately. Intense efforts will be needed from all sectors to bring demographic growth into balance with economic and development needs.

  17. The Problem of Population

    Institute of Scientific and Technical Information of China (English)

    刘香情; 钱丹

    2002-01-01

    With the population growing, a lot of problems have come out, Nowadays a lot of tall buildings have been built, but the houses are still very short; A lot of cars and buses have increased, but they are still crowded with people; A lot of schools have been built,

  18. Discussion Forum--Population Theories: Their Implications on Population Education.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter, 1983

    1983-01-01

    Contends that unless population education programs have a clear conceptual framework built upon a consistent set of population theories, they will remain merely as appendices to established school projects. Several population theories and their implications for population education are described. These include Malthusian demographic transition,…

  19. [The Marxist outlook on population].

    Science.gov (United States)

    Qin, R

    1984-09-29

    Marxist population theory and world population are discussed. From his study of capitalist population theory Marx concluded, "In capitalist reproduction, poverty produces population," thus rejecting Malthusian population determinism theory and developing economic determinism. According to UN statistics, world population has stabilized since the middle of this century after having doubled every hundred years for the last 300; population in the developed countries showed a positive decrease and average net population growth of the developing countries also decreased. The premise of this paper is that population grows according to social economy development. During the last several hundred years, world wealth increased much faster than population; in the last 200 years alone, the population has increased fivefold, but wealth fortyfold. In addition, world population analysis reveals an inverse relationship between wealth and population in the developed and developing countries: the poorer the country, the greater the population. From this perspective, the study of population must begin with surplus labor. Accumulation of surplus production is the foundation of continuous social development and the basis for population growth. The major difference in methods between capitalist countries and China is that the capitalist-planned fertility affects the individual family while Chinese-planned fertility has the whole nation in mind. Human fertility is determined by the economic system. Private ownership determines the private nature of fertility and public ownership determines the public nature of fertility. Thus population development is determined by the accumulation of social wealth.

  20. [Vietnam and its population].

    Science.gov (United States)

    Veron, J

    1993-01-01

    Viet Nam's 1993 population of 72 million makes it the second largest country of Southeast Asia after Indonesia. Viet Nam's demographic transition is underway, but growth is still a rapid 2% annually, a sufficiently high rate to hinder socioeconomic development. The 1979 and 1989 censuses and the 1988 Demographic and Health Survey are the major recent sources of data on Viet Nam's population. Marriage is universal in Viet Nam. Men marry at 24.5 and women at 23.2 years on average. Fertility estimates based on nonadjusted census data indicate a total fertility rate for 1988-89 of 3.8 overall, 2.2 in urban areas, and 4.3 in rural areas. Regional differences resulting from contraceptive usage, educational differentials, and tabus regarding spacing are strong. The average household size is 5. Viet Nam's first fertility reduction policy was announced in 1963 and sought to improve the welfare of women to increase their productivity for the war effort. More recent family planning policies are based on the view that rapid demographic growth is one of the great obstacles to development. The objectives of the current policy are to reduce the growth rate to 1% by the end of the century, increase contraceptive prevalence, delay arrival of the first child, limit family size to 2 children or 3 for ethnic minorities, and increase birth intervals from 3 to 5 years. The program is voluntarist in nature but includes incentives and disincentives. Life expectancy at birth in 1989 was 67.5 years for women and 63 for men. Infant mortality was 37/1000, with regional differentials. The principal causes of hospital deaths are tuberculosis, malaria, and diarrhea. Objectives of the current health policy are to prevent infectious diseases, reinforce primary health care services, promote traditional medicine, achieve self-sufficiency in basic medicines, and improve environmental health and access to clean water. Viet Nam is one of the most densely populated Southeast Asian countries and is still

  1. On optimal population paths

    CERN Document Server

    Lane, John S

    1977-01-01

    The overall purpose of this monograph is to integrate and critically evaluate the existing literature in the area of optimal joint savings population programs. The existing diverse presentations are all seen to be discussions within a unified framework. The central problem is to compare the desirability of alternative inter-temporal sequences of total savings and population sizes. Of critical importance is whether one regards persons as the fundamental moral entities or whether one takes Sidgwick's viewpoint that something good being the result of one's action is the baSic reason for dOing anything. The latter viewpoint is consistent with defining a complete social preference ordering over these alternative sequences. Since part of one's interest is to evaluate the consequences of various ethical beliefs a com­ parative study of several such orderings is presented; in particular the Mill-Wolfe average utilitarian, and Sidgwick-Meade classical utilitarian) formulations. A possible problem with the social pref...

  2. Cancer among circumpolar populations

    DEFF Research Database (Denmark)

    Young, T Kue; Kelly, Janet J; Friborg, Jeppe

    2016-01-01

    OBJECTIVES: To determine and compare the incidence of cancer among the 8 Arctic States and their northern regions, with special focus on 3 cross-national indigenous groups--Inuit, Athabaskan Indians and Sami. METHODS: Data were extracted from national and regional statistical agencies and cancer...... registries, with direct age-standardization of rates to the world standard population. For comparison, the "world average" rates as reported in the GLOBOCAN database were used. FINDINGS: Age-standardized incidence rates by cancer sites were computed for the 8 Arctic States and 20 of their northern regions......, averaged over the decade 2000-2009. Cancer of the lung and colon/rectum in both sexes are the commonest in most populations. We combined the Inuit from Alaska, Northwest Territories, Nunavut and Greenland into a "Circumpolar Inuit" group and tracked cancer trends over four 5-year periods from 1989 to 2008...

  3. Population consequences of reproductive decisions.

    Science.gov (United States)

    Smith, C; Reynolds, J D; Sutherland, W J

    2000-07-07

    Behaviour can be a key component of animal population ecology yet the population consequences of behavioural decisions are poorly understood. We conducted a behavioural and demographic study of the bitterling Rhodeus sericeus, a freshwater fish that spawns in live unionid mussels. We used a population model incorporating game theory decisions and measurements of demographic parameters in order to provide predictions of population size among 13 populations of this fish. Our model predicted that the observed behavioural spawning decisions, while maximizing individual fitness, cause a significant 6% reduction in population size compared with randomly distributed spawnings. We discuss our findings in the context of the population consequences of adaptive behaviour.

  4. Population, environment and development.

    Science.gov (United States)

    Karkal, M

    1994-06-01

    Western development models label subsistence economies, which do not participate in the market economy on a grand scale and do not consume commodities produced for and distributed through the market, to be poor. Yet, subsistence does not always indicate a low quality of life. The Western development process has destroyed wholesome and sustainable lifestyles. In India, the Green Revolution caused many small farmers to lose their land. In comparison to traditional economies, industrial economies have longer technological chains dependent on higher energy and resource inputs and exclude large numbers of people without power to buy goods. Further, they generate new and artificial needs, necessitating increased production of industrial goods and services. They erode resource bases for survival. This erosion is marginalizing people who were traditionally in nature's economy. Developed countries did not deliver 0.15% of their GNP to development projects in developing countries as promised. The US made population growth in these countries its cause. The UN and other multinational agencies during 1962-1972, at the US's request, began to support population and family planning programs in developing countries. These countries opposed the 1st draft at the 1974 Bucharest Population Conference, but by the conference in Mexico City, most supported the need for family planning. Yet, the US politicized this conference and had a greater say in the recommendations than did developing countries. Structural adjustments and external debt repayments required of developing countries in the 1980s set them back. In fact, the number of developing countries increased from 31 to 42. The UN recognizes the right to development, but social inequalities are barriers to this right. If environmental degradation continues, poverty will only increase. Women's groups are playing a great role in preparations for the International Conference on Population and Development in Cairo in September 1994.

  5. Population, desertification, and migration.

    Science.gov (United States)

    Westing, A H

    1994-01-01

    When an imbalance develops between population numbers and the carrying capacity of the land, the persons thereby displaced are referred to as environmental refugees. The utilization of the land beyond sustainability leads to land degradation and ultimately, desertification. The social and political impacts of long-term environmental migration can be distinguished: a) at the site of origin of the displaced persons by the residual population; b) at rural sites of destination within the nation between the new arrivals and preestablished populations; c) in the cities within the nation; d) in the nonindustrialized foreign countries; and e) in the industrialized foreign countries. In the event that an area which had previously been devoted to pastoralism is converted to agriculture, the displaced pastoralists might respond through armed rebellion. In some instances, the disenchanted urban squatters become a politically restive and even a destabilizing force, as occurred in Sudan in the 1980s, especially in Khartoum and Port Sudan. The foreign countries to which many of the displaced persons are migrating are subjected to increasing levels of migrant-induced economic, cultural, and political strains. The growing problems associated with south-to-north migration across the Mediterranean Sea have recently led France, Italy, Portugal, and Spain to enter into a consultative arrangement with Algeria, Libya, Mauritania, Morocco, and Tunisia. All foreign aid to the nonindustrialized countries that attempts to ameliorate the problem of desertification must adopt integrated approaches that: a) address population issues; b) support environmental education; c) provide for the protection of biodiversity; d) encourage participatory forms of local and national government; e) provide opportunities for income generation outside the livestock sector; and f) foster political security and facilitate ecogeographical (subregional) cooperation.

  6. Population and health policies

    OpenAIRE

    Schultz, T.Paul

    2009-01-01

    The program evaluation literature for population and health policies is in flux, with many disciplines documenting biological and behavioral linkages from fetal development to late life mortality, chronic disease, and disability, though their implications for policy remain uncertain. Both macro- and microeconomics seek to understand and incorporate connections between economic development and the demographic transition. The focus here is on research methods, findings, and questions that econo...

  7. Population consequences of reproductive decisions.

    OpenAIRE

    Smith, C; Reynolds, J.D.; Sutherland, W.J.

    2000-01-01

    Behaviour can be a key component of animal population ecology yet the population consequences of behavioural decisions are poorly understood. We conducted a behavioural and demographic study of the bitterling Rhodeus sericeus, a freshwater fish that spawns in live unionid mussels. We used a population model incorporating game theory decisions and measurements of demographic parameters in order to provide predictions of population size among 13 populations of this fish. Our model predicted tha...

  8. The population factor.

    Science.gov (United States)

    Kats, G

    1983-01-01

    Reducing population growth is essentil to Egypt's broader efforts to improve facilities, services, and the phsycial quality of life. Although a family planning program has existed since the mid-1950s, the 2.7% annual rate of population growth has not changed in 30 years. Nasser and the other "free officers" who seized power in 1952 became concerned about the adverse effects of the rapidly growing population, but perhaps out of concern with a possible religious backlash, they confined themselves to launching studies and subsidizing several dozen private family planning clinics. From 1962-72, the number of private clinics grew from 28 to 480, and family planning was introduced in government healthclinics in 1965. Such clinics are mainly located in rural areas and are staffed by doctors and other personnel who are not members of the local community and are not very effective at promoting family planning. Local girls and women called Rayadet were recruited to promote the idea to birth control in local communities. By 1970, 12.6% of Egyptians were using reliable contraception. A national survey 12 years later found 34% using contraception, buth the figure seems high. Approximately 60-65% of eligible couples would need to practice birth control for Egypt to reach a less than 1% annuel increase. The Egyptian government hopes to slow population growth to 1% by the year 2000, but major problems of motivation remain especially among the rural poor. Several factors may lead to success of the family planning effort: 1) financial and technical support from international family planning sources has grown rapidley and is likely to remain high; 2) the mortality rate has dropped from 17.8/1000 in 1952 to about half that level, while the rate of natural increase is about the same, suggesting that future reductions in the birth rate will translate to a reduced rate of natural increase, and that parents will be less reluctant to practice faimly planning if there is a greater chance

  9. Population and climate change.

    Science.gov (United States)

    Cohen, Joel E

    2010-06-01

    To review, the four broad dimensions of any complex human problem, including climate change, are the human population, economics, culture, and environment. These dimensions interact with one another in all directions and on many time-scales. From 2010 to 2050, the human population is likely to grow bigger, more slowly, older, and more urban. It is projected that by 2050 more than 2.6 billion people (almost 94% of global urban growth) will be added to the urban population in today's developing countries. That works out to 1.26 million additional urban people in today's developing countries every week from 2010 to 2050. Humans alter the climate by emitting greenhouse gases, by altering planetary albedo, and by altering atmospheric components. Between 1900 and 2000, humans' emissions of carbon into the atmosphere increased fifteenfold, while the numbers of people increased less than fourfold. Population growth alone, with constant rates of emissions per person, could not account for the increase in the carbon emissions to the atmosphere. The world economy grew sixteenfold in the twentieth century, accompanied by enormous increases in the burning of gas, oil, and coal. In the last quarter of the twentieth century, population grew much faster in developing countries than in high-income countries, and, compared with population growth, the growth of carbon emissions to the atmosphere was even faster in developing countries than in high-income countries. The ratio of emissions-to-population growth rates was 2.8 in developing countries compared with 1.6 in high-income countries. Emissions of CO2 and other greenhouse gases are influenced by the sizes and density of settlements, the sizes of households, and the ages of householders. Between 2010 and 2050, these demographic factors are anticipated to change substantially. Therefore demography will play a substantial role in the dynamics of climate changes. Climate changes affect many aspects of the living environment

  10. Diabetes in population isolates

    DEFF Research Database (Denmark)

    Grarup, Niels; Moltke, Ida; Albrechtsen, Anders

    2015-01-01

    Type 2 diabetes (T2D) is an increasing health problem worldwide with particularly high occurrence in specific subpopulations and ancestry groups. The high prevalence of T2D is caused both by changes in lifestyle and genetic predisposition. A large number of studies have sought to identify...... on glucose-stimulated plasma glucose, serum insulin levels, and T2D. The variant defines a specific subtype of non-autoimmune diabetes characterized by decreased post-prandial glucose uptake and muscular insulin resistance. These and other recent findings in population isolates illustrate the value...

  11. Playing With Population Protocols

    Directory of Open Access Journals (Sweden)

    Xavier Koegler

    2009-06-01

    Full Text Available Population protocols have been introduced as a model of sensor networks consisting of very limited mobile agents with no control over their own movement: A collection of anonymous agents, modeled by finite automata, interact in pairs according to some rules. Predicates on the initial configurations that can be computed by such protocols have been characterized under several hypotheses. We discuss here whether and when the rules of interactions between agents can be seen as a game from game theory. We do so by discussing several basic protocols.

  12. 从populations谈population

    Institute of Scientific and Technical Information of China (English)

    刘超

    2000-01-01

    高中英语课本第二册第9单元里有这样一个句子:“Many parts of the world.which once had large populations and produced plenty of crops.have become deserts.”(世界上很多地区,一度人口众多。生产过大量农作物,现在已经变成沙漠了。)这就说明,表“人口”一般用population,也可以用populations。

  13. [Roma populations and health].

    Science.gov (United States)

    Jackson, Y; Tabin, J P; Hourton, G; Bodenmann, P

    2015-03-25

    The health status of the so-called "Roma" is usually much poorer than that of neighbouring non-Roma populations with a life expectancy gap of 5-15 years. This results from prolonged exposure to adverse determinants of health and to persistent exclusion from social and political arenas. Scientific and social research has only poorly addressed the health issues of Roma and evidences are scarce. Insufficient access to public services, including to health care and non optimal clinical practices are modifiable factors. If correctly addressed, this could contribute to reduce health disparities, including in Switzerland.

  14. Density Estimation in Several Populations With Uncertain Population Membership

    KAUST Repository

    Ma, Yanyuan

    2011-09-01

    We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.

  15. The Resonant Transneptunian Populations

    CERN Document Server

    Gladman, B; Petit, J-M; Kavelaars, J; Jones, R L; Parker, J Wm; Van Laerhoven, C; Nicholson, P; Rousselot, P; Bieryla, A; Ashby, M L N

    2012-01-01

    The transneptunian objects (TNOs) trapped in mean-motion resonances with Neptune were likely emplaced there during planet migration late in the giant-planet formation process. We perform detailed modelling of the resonant objects detected in the Canada-France Ecliptic Plane Survey (CFEPS) in order to provide population estimates and, for some resonances, constrain the complex internal orbital element distribution. Detection biases play a critical role because phase relationships with Neptune make object discovery more likely at certain longitudes. This paper discusses the 3:2, 5:2, 2:1, 3:1, 5:1, 4:3, 5:3, 7:3, 5:4, and 7:4 mean-motion resonances, all of which had CFEPS detections, along with our upper limit on 1:1 Neptune Trojans (which is consistent with their small population estimated elsewhere). For the plutinos (TNOs in the 3:2 resonance) we refine the orbital element distribution given in Kavelaars et al. (2009) and show that steep H-magnitude distributions (N(H) proportional to 10aH, with a=0.8-0.9) a...

  16. Population III Hypernovae

    CERN Document Server

    Smidt, Joseph; Even, Wesley; Wiggins, Brandon; Johnson, Jarrett L; Fryer, Chris L

    2014-01-01

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. But until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic lighthouses at the highest redshifts. In this, the latest of a series of studies on Population III supernovae, we present numerical simulations of 25 - 50 M$_{\\odot}$ hypernovae and their light curves done with the Los Alamos RAGE and SPECTRUM codes. We find that they will be visible at z = 10 - 15 to the James Webb Space Telescope (JWST) and z = 4 - 5 to the Wide-Field Infrared Survey Telescope (WFIRST), tracing star formation rates in the first galaxies and at the end of cosmological reionization. If, however, the hypernova crashes into a dense shell ejected by its progenitor, a superluminous event will occur that may be se...

  17. POPULATION III HYPERNOVAE

    Energy Technology Data Exchange (ETDEWEB)

    Smidt, Joseph; Whalen, Daniel J. [T-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Wiggins, Brandon K. [Department of Physics and Astronomy, Brigham Young University, Provo, UT 84602 (United States); Even, Wesley; Fryer, Chris L. [CCS-2, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Johnson, Jarrett L., E-mail: dwhalen1999@gmail.com [XTD-PRI, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2014-12-20

    Population III supernovae have been of growing interest of late for their potential to directly probe the properties of the first stars, particularly the most energetic events that are visible near the edge of the observable universe. Until now, hypernovae, the unusually energetic Type Ib/c supernovae that are sometimes associated with gamma-ray bursts, have been overlooked as cosmic beacons at the highest redshifts. In this, the latest of a series of studies on Population III supernovae, we present numerical simulations of 25-50 M {sub ☉} hypernovae and their light curves done with the Los Alamos RAGE and SPECTRUM codes. We find that they will be visible at z = 10-15 to the James Webb Space Telescope and z = 4-5 to the Wide-Field Infrared Survey Telescope, tracing star formation rates in the first galaxies and at the end of cosmological reionization. If, however, the hypernova crashes into a dense shell ejected by its progenitor, it is expected that a superluminous event will occur that may be seen at z ∼ 20 in the first generation of stars.

  18. Innovations in Population Education: Conveying Population Education through Games.

    Science.gov (United States)

    Villanueva, Carmelita L., Ed.

    1987-01-01

    The use of games and simulations is a method that educators are finding especially useful in presenting information about population concerns. The "Futures Wheels" is a participatory classroom exercise, designed to demonstrate probable consequences of future population increases and is also used to illustrate a wide range of population related…

  19. Training Manual in Population Education. Population Education Programme Service.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and Oceania.

    Population education is at different stages of development in the Asian countries, but almost all of the countries show an interest in developing population education programs. This manual for designing and implementing population education programs consists of six chapters. Chapter one highlights issues and problems arising in connection with…

  20. CDC WONDER: Population (from Census)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population online databases contain data from the US Census Bureau. The Census Estimates online database contains contains county-level population counts for...

  1. NASA Orbital Debris Baseline Populations

    Science.gov (United States)

    Krisko, Paula H.; Vavrin, A. B.

    2013-01-01

    The NASA Orbital Debris Program Office has created high fidelity populations of the debris environment. The populations include objects of 1 cm and larger in Low Earth Orbit through Geosynchronous Transfer Orbit. They were designed for the purpose of assisting debris researchers and sensor developers in planning and testing. This environment is derived directly from the newest ORDEM model populations which include a background derived from LEGEND, as well as specific events such as the Chinese ASAT test, the Iridium 33/Cosmos 2251 accidental collision, the RORSAT sodium-potassium droplet releases, and other miscellaneous events. It is the most realistic ODPO debris population to date. In this paper we present the populations in chart form. We describe derivations of the background population and the specific populations added on. We validate our 1 cm and larger Low Earth Orbit population against SSN, Haystack, and HAX radar measurements.

  2. CDC WONDER: Population (from Census)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Population online databases contain data from the US Census Bureau. The Census Estimates online database contains county-level population counts for years 1970 -...

  3. Correlations and Neuronal Population Information.

    Science.gov (United States)

    Kohn, Adam; Coen-Cagli, Ruben; Kanitscheider, Ingmar; Pouget, Alexandre

    2016-07-01

    Brain function involves the activity of neuronal populations. Much recent effort has been devoted to measuring the activity of neuronal populations in different parts of the brain under various experimental conditions. Population activity patterns contain rich structure, yet many studies have focused on measuring pairwise relationships between members of a larger population-termed noise correlations. Here we review recent progress in understanding how these correlations affect population information, how information should be quantified, and what mechanisms may give rise to correlations. As population coding theory has improved, it has made clear that some forms of correlation are more important for information than others. We argue that this is a critical lesson for those interested in neuronal population responses more generally: Descriptions of population responses should be motivated by and linked to well-specified function. Within this context, we offer suggestions of where current theoretical frameworks fall short.

  4. Population, migration and urbanization.

    Science.gov (United States)

    1982-06-01

    Despite recent estimates that natural increase is becoming a more important component of urban growth than rural urban transfer (excess of inmigrants over outmigrants), the share of migration in the total population growth has been consistently increasing in both developed and developing countries. From a demographic perspective, the migration process involves 3 elements: an area of origin which the mover leaves and where he or she is considered an outmigrant; the destination or place of inmigration; and the period over which migration is measured. The 2 basic types of migration are internal and international. Internal migration consists of rural to urban migration, urban to urban migration, rural to rural migration, and urban to rural migration. Among these 4 types of migration various patterns or processes are followed. Migration may be direct when the migrant moves directly from the village to the city and stays there permanently. It can be circular migration, meaning that the migrant moves to the city when it is not planting season and returns to the village when he is needed on the farm. In stage migration the migrant makes a series of moves, each to a city closer to the largest or fastest growing city. Temporary migration may be 1 time or cyclical. The most dominant pattern of internal migration is rural urban. The contribution of migration to urbanization is evident. For example, the rapid urbanization and increase in urban growth from 1960-70 in the Republic of Korea can be attributed to net migration. In Asia the largest component of the population movement consists of individuals and groups moving from 1 rural location to another. Recently, because urban centers could no longer absorb the growing number of migrants from other places, there has been increased interest in the urban to rural population redistribution. This reverse migration also has come about due to slower rates of employment growth in the urban centers and improved economic opportunities

  5. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  6. Population Parameters of Beaked Whales

    Science.gov (United States)

    2012-09-30

    of deep diving cetaceans , their use of the habitat, and their sensitivity to human interactions . The results will facilitate improved regional...augment the sparse knowledge of beaked whale population biology, facilitating the assessment of possible population effects of human impacts...potential population effects of human impacts. Economic development Economic development is often related to increasing noise levels in the ocean

  7. A Population of Assessment Tasks

    Science.gov (United States)

    Daro, Phil; Burkhardt, Hugh

    2012-01-01

    We propose the development of a "population" of high-quality assessment tasks that cover the performance goals set out in the "Common Core State Standards for Mathematics." The population will be published. Tests are drawn from this population as a structured random sample guided by a "balancing algorithm."

  8. Population Education Documents, Reprint Series.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and Oceania.

    This publication contains reprints of five documents that were either published in foreign journals or released in limited numbers by author or publisher. The papers are all concerned with population education, but deal more specifically with the role of population and the schools. Among the topics discussed are population education and the school…

  9. Stochastic population theories

    CERN Document Server

    Ludwig, Donald

    1974-01-01

    These notes serve as an introduction to stochastic theories which are useful in population biology; they are based on a course given at the Courant Institute, New York, in the Spring of 1974. In order to make the material. accessible to a wide audience, it is assumed that the reader has only a slight acquaintance with probability theory and differential equations. The more sophisticated topics, such as the qualitative behavior of nonlinear models, are approached through a succession of simpler problems. Emphasis is placed upon intuitive interpretations, rather than upon formal proofs. In most cases, the reader is referred elsewhere for a rigorous development. On the other hand, an attempt has been made to treat simple, useful models in some detail. Thus these notes complement the existing mathematical literature, and there appears to be little duplication of existing works. The authors are indebted to Miss Jeanette Figueroa for her beautiful and speedy typing of this work. The research was supported by the Na...

  10. Population, food and knowledge

    DEFF Research Database (Denmark)

    Strulik, Holger; Weisdorf, Jacob Louis

    2008-01-01

    of population. London, printed for J. Johnson, 1798) so-called preventive check hypothesis-that fertility rates vary inversely with the price of food-the current study offers a new and straightforward explanation for the demographic transition and the break with the Malthusian era. Employing a two......-sector framework with agriculture and industry, we demonstrate how fertility responds differently to productivity and income growth, depending on whether it emerges in agriculture or industry. Agricultural productivity and income growth makes food goods, and therefore children, relatively less expensive....... Industrial productivity and income growth, on the other hand, makes food goods, and therefore children, relatively more expensive. The present framework lends support to existing unified growth theories and is well in tune with historical evidence about structural transformation....

  11. Population and health.

    Science.gov (United States)

    Kwon, E H

    1975-01-01

    Quality of population is as important as quantity when one is discussing public health needs or quality of the labor force. Population quality as measured by physical disease, mental disease, maternal death and morbidity rates, fetal and infant mortality rates, and family size and child health is discussed. Charts give figures for Korea from a variety of sample surveys and census studies for 1973. All developing countries have high child death rates from communicable diseases. Korea, in addition, suffers from several parasitic diseases. The problems of maternal death and morbidity are due to disease, hard physical labor during pregnancy, poorly attended births (26% were attended by a mother or mother-in-law and 11% by friends and relatives), and high parity. Figures show that the danger of childbirth is greatest for the 1st baby, lower for the 2nd and 3rd, then rises, climbing steeply after the 5th birth. Iron deficiency anemia and oxalic acid deficiency together with general malnutrition contribute to high maternal morbidity and mortality and fetal death or improper brain development. It is also well accepted that children from large families have slower physical and mental growth than children in smaller families. Family planning problems can best be solved by integrating birth spacing and birth limitation programs into a total maternal and child health scheme and emphasizing the health aspects of family planning. Maternity-centered family planning is but 1 example of such an integrated approach. This integration will make better use of personnel, result in better program supervision, and will help the mother understand it is in her best interest to practice family planning.

  12. Population and the World Bank.

    Science.gov (United States)

    Sankaran, S

    1973-12-01

    The World Bank Group regards excessive population growth as the single greatest obstacle to economic and social advance in the underdeveloped world. Since 1969 the Bank and the International Development Agency have provided countries with technical assistance through education, fact-finding, and analysis and given 65.7 million dollars for population projects. These projects, in India, Indonesia, Iran, Jamaica, and Malaysia provide training centers, population education, research, and evaluation as well as actual construction of clinics and mobile units. Because population planning touches sensitive areas of religion, caste, race, morality, and politics, the involved nation's political commitment to plan population growth is critical to the success of any program.

  13. Language dynamics in finite populations.

    Science.gov (United States)

    Komarova, Natalia L; Nowak, Martin A

    2003-04-01

    Any mechanism of language acquisition can only learn a restricted set of grammars. The human brain contains a mechanism for language acquisition which can learn a restricted set of grammars. The theory of this restricted set is universal grammar (UG). UG has to be sufficiently specific to induce linguistic coherence in a population. This phenomenon is known as "coherence threshold". Previously, we have calculated the coherence threshold for deterministic dynamics and infinitely large populations. Here, we extend the framework to stochastic processes and finite populations. If there is selection for communicative function (selective language dynamics), then the analytic results for infinite populations are excellent approximations for finite populations; as expected, finite populations need a slightly higher accuracy of language acquisition to maintain coherence. If there is no selection for communicative function (neutral language dynamics), then linguistic coherence is only possible for finite populations.

  14. Population Health and Occupational Therapy.

    Science.gov (United States)

    Braveman, Brent

    2016-01-01

    Occupational therapy practitioners play an important role in improving the health of populations through the development of occupational therapy interventions at the population level and through advocacy to address occupational participation and the multiple determinants of health. This article defines and explores population health as a concept and describes the appropriateness of occupational therapy practice in population health. Support of population health practice as evidenced in the official documents of the American Occupational Therapy Association and the relevance of population health for occupational therapy as a profession are reviewed. Recommendations and directions for the future are included related to celebration of the achievements of occupational therapy practitioners in the area of population health, changes to the Occupational Therapy Practice Framework and educational accreditation standards, and the importance of supporting, recognizing, rewarding, and valuing occupational therapy practitioners who assume roles in which direct care is not their primary function. Copyright © 2016 by the American Occupational Therapy Association, Inc.

  15. Stellar populations in star clusters

    CERN Document Server

    Li, Chengyuan; Deng, Licai

    2016-01-01

    Stellar populations contain the most important information about star clus- ter formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ...

  16. European population substructure: clustering of northern and southern populations.

    Directory of Open Access Journals (Sweden)

    Michael F Seldin

    2006-09-01

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

  17. Population distribution and population growth in Yogyakarta special region

    Directory of Open Access Journals (Sweden)

    Ida Bagus Mantra

    2013-07-01

    The annual rate of population growth in Yogyakarta Special Region is much lower compared with other provinces in Java. During 1961 and 1971 the rate of population growth was 1.1 percent, for the period 1971— 1980 became 1.09 percent. This region experienced a net loss of population through migration, and that the losses were greater in the poor areas of Gunung Kidul and Kulon Progo

  18. population in Slovakia

    Directory of Open Access Journals (Sweden)

    Dravecký Miroslav

    2015-06-01

    Full Text Available V rokoch 2011 – 2014 sa realizoval monitoring hniezdnej populácie orla krikľavého (Aquila pomarina v ôsmich chránených vtáčích územiach na Slovensku. U 149 hniezdnych párov z celkových 272 úspešných hniezdení počas 4 hniezdnych sezón vyletelo 277 mláďat. Priemerná reprodukčná úspešnosť predstavovala 0,51 juv./prítomný pár, 0,69 juv./hniezdiaci pár a 1,37 juv./100 km2. V uvedenom období bolo okolo hniezd orlov krikľavých ustanovených celkom 151 ochranných zón, ktoré zabezpečili ochranu 119 hniezdnych teritórií, čo predstavuje cca 17 % hniezdnej populácie orla krikľavého na Slovensku. Testovaním účinnosti ochranných zón sa zistilo, že v hniezdach s vyhlásenou ochrannou zónou je vyššia pravdepodobnosť úspešného odchovania mláďat v porovnaní s hniezdami bez takejto zóny. Pravdepodobnosť, že hniezdenie bude úspešné v hniezdach hniezdiacich párov bez ochrannej zóny bola 48.1% (95% confidence intervals (CIs: 37.4–59.0%, v hniezdach s ochrannou zónou 64.8% (95% CIs: 59.8–69.6%. Medzi 5 najčastejšie využívaných hniezdnych stromov na hniezdenie A. pomarina na Slovensku patrí Picea abies 61× (28,4%, Pinus sylvestris 45× (20,9%, Quercus sp. 36× (16,7%, Fagus sylvatica 25× (11,6% a Abies alba 18× (8,4%. Medzi zriedkavejšie druhy hniezdnych stromov patrí Larix decidua 12× (5,6% a Alnus glutinosa 3× (1,4%, ďalších 11 druhov hniezdnych stromov nedosiahli 1 %. Najvyšší počet hniezdnych stromov (n = 215, tj. 34 hniezd (15,8% sa nachádzal v intervale nadmorskej výšky 401 – 450 m a 29 hniezd (13,5% v intervale 351 – 400 m n. m. Ostatné výškové pásma boli pod hranicou 10%. 54% zistených hniezd (116 hniezd sa nachádza vo výškovom pásme 301 – 600 m n. m., 71 hniezd (33% v pásme 600 – 900 m n. m. Najnižšie situované hniezdo bolo v nadmorskej výške 150 m a najvyššie 950 m, priemer bol 595,01 m. Najvyšší počet hniezd (n = 209 bol na strome

  19. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Rodney van der Ree

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a "reconnected" population remained 15% lower than that of a comparable "undivided" population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  20. Population growth, poverty and health.

    Science.gov (United States)

    Kibirige, J S

    1997-07-01

    One of the most popular explanations for the many problems that face Africa is population growth. Africa's population has doubled since 1960. Africa has the highest fertility rate in the world and the rate of population growth is higher than in any other region. At the same time, Africa faces a social and economic situation that is viewed by many as alarming. Among the problems that devastate Africa is that of persistent poor health. Africa has lower life expectancy, higher mortality rates and is affected by more disease and illness conditions than any other region. Focusing on sub-Saharan Africa, this paper examines the relationship between population growth, poverty and poor health. While most analyses have focused on population growth as an original cause of poverty and underdevelopment, this paper argues that while both population growth and poor health play a significant role in exacerbating the problem of poverty, they are themselves primary consequences of poverty rather than its cause.

  1. Habitat quality and fish population

    OpenAIRE

    Tafesse Tirkaso, Wondmagegn; Gren, Ing-Marie

    2016-01-01

    Degradation of marine ecosystem due to, among others, eutrophication and climate change, has been of concern for sustainable fishery management worldwide, but studies on associated impacts on fish populations are rare. The purpose of this study is to estimate effects of nutrient loads, which cause eutrophication, on the perch population at the Swedish east coast. To this end, we use a modified Gordon-Schaefer logistic growth model for econometric estimation of perch population on the Swedish ...

  2. Population ageing: crisis or opportunity?

    OpenAIRE

    Ermisch, John

    2008-01-01

    Population ageing reduces the working population relative to the number of pensions by one-third over next 30 years. The challenge presented by this development is how best to support pensioners’ incomes without suppressing the net incomes of the working population and capital accumulation too much. The ability of private savings and occupational pensions to meet this challenge is doubtful. There is a related issue of inter-generational equity: how do we share the burden of population agein...

  3. [Population control and environment protection].

    Science.gov (United States)

    Qu, G

    1982-01-29

    Although many factors cause environmental pollution and damage, the most important and basic factor is a rapidly increasing population. Therefore, a balanced development of population and environment is essential. The pressure a rapidly increasing populaton exerts on the environment has many aspects. The pressure of population on land resources results in increased land use and increased insecticide use due to increased insect tolerance leading to decreased productivity of cultivated land, increased desert formation, and decreased food supply. Population pressure on forest resources leads to land erosion; one of the major causes of the 1981 flood in Sichuan was attributed to excessive logging activities. Demand for fuels (firewood, straws, animal manures) by an increasing population leads to decrease in natural fertilizers, decreased food production, and energy shortage in rural areas. Population pressure on cities leads to air, water, noise and other environmental pollution as well as decrease in housing facilities and in green vegetation. Problems resulting from population pressures on industrial development include industrial and environmental pollution and unemployment. Population increases and accompanying industrial activities affect the weather which in turn affects the quality of agriculture, forests, and lakes. Thus, if unchecked, atmospheric carbon dioxide level would double by the middle of the next century, which would lead to increase in atmospheric temperature with disastrous consequences. Therefore, a well planned program for population control is essential for achieving decent quality of life.

  4. Population dynamics and population control of Galium aparine L.

    NARCIS (Netherlands)

    Weide, van der R.Y.

    1993-01-01

    The population biology of Galium aparine L. needs to be better understood, in order to be able to rationalize decisions about the short- and long-term control of this weed species for different cropping practices.A population dynamics model was developed to simulate the basic processes of the life c

  5. Detection, Diversity, and Population Dynamics of Waterborne Phytophthora ramorum Populations.

    Science.gov (United States)

    Eyre, C A; Garbelotto, M

    2015-01-01

    Sudden oak death, the tree disease caused by Phytophthora ramorum, has significant environmental and economic impacts on natural forests on the U.S. west coast, plantations in the United Kingdom, and in the worldwide nursery trade. Stream baiting is vital for monitoring and early detection of the pathogen in high-risk areas and is performed routinely; however, little is known about the nature of water-borne P. ramorum populations. Two drainages in an infested California forest were monitored intensively using stream-baiting for 2 years between 2009 and 2011. Pathogen presence was determined both by isolation and polymerase chain reaction (PCR) from symptomatic bait leaves. Isolates were analyzed using simple sequence repeats to study population dynamics and genetic structure through time. Isolation was successful primarily only during spring conditions, while PCR extended the period of pathogen detection to most of the year. Water populations were extremely diverse, and changed between seasons and years. A few abundant genotypes dominated the water during conditions considered optimal for aerial populations, and matched those dominant in aerial populations. Temporal patterns of genotypic diversification and evenness were identical among aerial, soil, and water populations, indicating that all three substrates are part of the same epidemiological cycle, strongly influenced by rainfall and sporulation on leaves. However, there was structuring between substrates, likely arising due to reduced selection pressure in the water. Additionally, water populations showed wholesale mixing of genotypes without the evident spatial autocorrelation present in leaf and soil populations.

  6. Population Education: A Critical Population and Development Intervention.

    Science.gov (United States)

    United Nations Population Fund (UNFPA)

    1991-01-01

    This review and assessment of population education programs demonstrates that, although population education has made many contributions to the overall education process, its success requires continual revision and review of existing conceptualizations and content. Outlines and discusses other critical factors, pertinent issues, and guidelines for…

  7. Matrix population models from 20 studies of perennial plant populations

    Science.gov (United States)

    Ellis, Martha M.; Williams, Jennifer L.; Lesica, Peter; Bell, Timothy J.; Bierzychudek, Paulette; Bowles, Marlin; Crone, Elizabeth E.; Doak, Daniel F.; Ehrlen, Johan; Ellis-Adam, Albertine; McEachern, Kathryn; Ganesan, Rengaian; Latham, Penelope; Luijten, Sheila; Kaye, Thomas N.; Knight, Tiffany M.; Menges, Eric S.; Morris, William F.; den Nijs, Hans; Oostermeijer, Gerard; Quintana-Ascencio, Pedro F.; Shelly, J. Stephen; Stanley, Amanda; Thorpe, Andrea; Tamara, Ticktin; Valverde, Teresa; Weekley, Carl W.

    2012-01-01

    Demographic transition matrices are one of the most commonly applied population models for both basic and applied ecological research. The relatively simple framework of these models and simple, easily interpretable summary statistics they produce have prompted the wide use of these models across an exceptionally broad range of taxa. Here, we provide annual transition matrices and observed stage structures/population sizes for 20 perennial plant species which have been the focal species for long-term demographic monitoring. These data were assembled as part of the 'Testing Matrix Models' working group through the National Center for Ecological Analysis and Synthesis (NCEAS). In sum, these data represent 82 populations with >460 total population-years of data. It is our hope that making these data available will help promote and improve our ability to monitor and understand plant population dynamics.

  8. Stochastic delocalization of finite populations

    Science.gov (United States)

    Geyrhofer, Lukas; Hallatschek, Oskar

    2013-01-01

    The localization of populations of replicating bacteria, viruses or autocatalytic chemicals arises in various contexts, such as ecology, evolution, medicine or chemistry. Several deterministic mathematical models have been used to characterize the conditions under which localized states can form, and how they break down due to convective driving forces. It has been repeatedly found that populations remain localized unless the bias exceeds a critical threshold value, and that close to the transition the population is characterized by a diverging length scale. These results, however, have been obtained upon ignoring number fluctuations (‘genetic drift’), which are inevitable given the discreteness of the replicating entities. Here, we study the localization/delocalization of a finite population in the presence of genetic drift. The population is modeled by a linear chain of subpopulations, or demes, which exchange migrants at a constant rate. Individuals in one particular deme, called ‘oasis’, receive a growth rate benefit, and the total population is regulated to have constant size N. In this ecological setting, we find that any finite population delocalizes on sufficiently long time scales. Depending on parameters, however, populations may remain localized for a very long time. The typical waiting time to delocalization increases exponentially with both population size and distance to the critical wind speed of the deterministic approximation. We augment these simulation results by a mathematical analysis that treats the reproduction and migration of individuals as branching random walks subject to global constraints. For a particular constraint, different from a fixed population size constraint, this model yields a solvable first moment equation. We find that this solvable model approximates very well the fixed population size model for large populations, but starts to deviate as population sizes are small. Nevertheless, the qualitative behavior of the

  9. [Population policy: speeches and actions].

    Science.gov (United States)

    Soto Lopez, A

    1991-06-01

    Mexico's population policy was created almost 20 years ago in response to the need to regulate the country's population growth. Currently the policy stresses more balanced distribution of the population in accordance with realistic development possibilities. By 1986 it was recognized that population policy in Mexico had gone beyond mere control of fertility to encompass direct government intervention in more complex global problems. It was concluded that the possibility of achieving rational population distribution depended on balanced regional development. A strong family planning policy, efforts to integrate demographic programs into general development plans, employment policies, and measures to encourage harmonious spatial distribution were viewed as necessary, but it was also felt that greater speed was required and that the population policy should play a larger role in the development strategy. The National Population Program for 1989-94 has the objectives of promoting the integration of demographic objectives into economic and social planning and promoting a decline in the rate of population growth from 1.8% in 1995 to 1.5% in 2000 through fertility decline. It seeks a more rational population distribution in which the weight of large metropolitan zones would be reduced and growth of intermediate and small cities promoted. It seeks to encourage greater participation by women in the nation's life, and to contribute to integrated development and elevation in the living standards of indigenous groups. In presentation of the National Population Program it was noted that the economic crisis of the 1980s had reversed some previous demographic achievements. greater efforts are necessary to involve the rural and indigenous groups. In presentation of the National Population Program it was noted that the economic crisis of the 1980s had reversed some previous demographic achievements. Greater efforts are necessary to involve the rural and indigenous populations

  10. Admixed human embryos and stem cells: legislative, ethical and scientific advances.

    Science.gov (United States)

    Bahadur, G; Iqbal, M; Malik, S; Sanyal, A; Wafa, R; Noble, R

    2008-01-01

    This paper examines the regulatory framework currently governing the creation of animal-human hybrids and chimera embryos in stem cell research, and some of the ethical implications of such research. It discusses the findings of a recent government select committee that considered the topic. It considers the debate around the precise definition of a human embryo, and whether such hybrids therefore fall within the remit of the Human Fertilisation and Embryology Authority. It outlines the advantages of such hybrids, in lessening the need for human egg donors, as well as the moral objections to species boundary violation. It calls for an examination of the scientific benefits of such research to inform debate on the question, and argues for the need to take genuine account of the public's views on this matter.

  11. Scintillation properties of a La, Lu-admix gadolinium pyrosilicate crystal

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, Shunsuke, E-mail: kurosawa@imr.tohoku.ac.jp [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Shishido, Toetsu; Suzuki, Akira; Sugawara, Takamasa; Nomura, Akiko; Yubuta, Kunio [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Shoji, Yasuhiro [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yokota, Yuui [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Pejchal, Jan [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); Institute of Physics, AS CR, Cukrovarnická 10, 162 53 Prague (Czech Republic); Ohashi, Yuji [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Kamada, Kei [New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); Yoshikawa, Akira [Institute for Materials Research (IMR), Tohoku University 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan); New Industry Creation Hatchery Center (NICHe) 6-6-10 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579 (Japan); C& A Corporation, 6-6-40 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

    2015-06-01

    In order to obtain new scintillator with higher effective atomic number, a pyrosilicate crystal with a composition (Ce{sub 0.01}, Gd{sub 0.54}, La{sub 0.25}, Lu{sub 0.20}){sub 2}Si{sub 2}O{sub 7} (Ce:LaLu-GPS) was grown by the floating zone method. Emission wavelengths of this material were at 370 and 390 nm. Gamma-ray-excited pulse height and scintillation decay measurement showed that Ce:LaLu-GPS had a light output of 34,000±2000 photons/MeV, an FWHM energy resolution of 6.9±0.2%, and the decay time components of 59±1 ns (13%) and 570±20 ns (87%)

  12. Is black coat color in wolves of Iran an evidence of admixed ancestry with dogs?

    Science.gov (United States)

    Khosravi, Rasoul; Asadi Aghbolaghi, Marzieh; Rezaei, Hamid Reza; Nourani, Elham; Kaboli, Mohammad

    2015-02-01

    Melanism is not considered a typical characteristic in wolves of Iran and dark wolves are believed to have originated from crossbreeding with dogs. Such hybrid individuals can be identified with the combined use of genetic and morphological markers. We analyzed two black wolves using a 544 base pairs (bp) fragment of the mtDNA control region and 15 microsatellite loci in comparison with 28 dogs, 28 wolves, and four known hybrids. The artificial neural networks (ANNs) method was applied to microsatellite data to separate genetically differentiated samples of wolves, dogs, and hybrids, and to determine the correct class for the black specimens. Individual assignments based on ANNs showed that black samples were genetically closer to wolves. Also, in the neighbor-joining network of mtDNA haplotypes, wolves and dogs were separated, with the dark specimens located in the wolf branch as two separate haplotypes. Furthermore, we compared 20 craniometrical characters of the two black individuals with 14 other wolves. The results showed that craniometrical measures of the two black wolves fall within the range of wolf skulls. We found no trace of recent hybridization with free-ranging dogs in the two black wolves. Dark coat color might be the result of a natural combination of alleles in the coat-color-determining gene, mutation in the K locus due to past hybridization with free-ranging dogs, or the effect of ecological factors and adaption to habitat conditions.

  13. THE INFLUENCE OF TEMPERATURE AND ADMIX- TURES ON ACTIVATION OF LOW CALCIUM FLY ASH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to composition and structure properties of low calcium fly ash, the activation and reaction degree of fly ash-lime and fly ash-lime-gypsum system were studied in different alkali surroundings and temperatures by thermal-gravity analysis.The degree of reaction and pore structure analysis test results show that composite alkali play an important role in the activation and degree of reaction of fly ash at room temperature. But when increasing curing temperature, gypsum would play an important role in activation and hydration of fly ash.

  14. Plasticity, Swell-Shrink, and Microstructure of Phosphogypsum Admixed Lime Stabilized Expansive Soil

    Directory of Open Access Journals (Sweden)

    Jijo James

    2016-01-01

    Full Text Available The study involved utilization of an industrial waste, Phosphogypsum (PG, as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL, optimum lime content (OLC, and less than ICL (LICL, were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic limit, shrinkage limit, and free swell test, on pulverized remains of failed unconfined compression test specimens. The samples were also subjected to a microstructural study by means of scanning electron microscope. Addition of PG to lime resulted in improvement in the plasticity and swell-shrink characteristics. The microstructural study revealed the formation of a dense compact mass of stabilized soil.

  15. Properties of Laser Produced TMAE Plasma Admixed with Air Constituents, Nitrogen and Noble Gases

    Science.gov (United States)

    Ding, Guowen; Scharer, John; Kelly, Kurt

    1999-10-01

    A high initial density (> 10^13 cm-3) and a large volume (hundreds of cm^3) plasma is created by a 193 nm laser ionization of an organic molecule, tetrakis(dimethyl-amino)ethylene(TMAE). The properties of this plasma mixed with nitrogen and noble gases are studied. Fast probe measurements which include a detailed considerations of probe structure, probe surface cleaning, shielding, probe perturbation, frequency response, temporal and spatial resolutions, dummy probe corrections and noise analysis will be described. Electron densities obtained by this method are independent on the ion species mixture. A plasma emission diagnostic is used to estimate plasma densities for the higher admixture pressures. Electron density and temperature vs. time for various TMAE, nitrogen and noble gas pressures and laser power will be presented. The role of super-excited and metastable states in the decay process will also be discussed.

  16. Stellar populations in star clusters

    Science.gov (United States)

    Li, Cheng-Yuan; de Grijs, Richard; Deng, Li-Cai

    2016-12-01

    Stellar populations contain the most important information about star cluster formation and evolution. Until several decades ago, star clusters were believed to be ideal laboratories for studies of simple stellar populations (SSPs). However, discoveries of multiple stellar populations in Galactic globular clusters have expanded our view on stellar populations in star clusters. They have simultaneously generated a number of controversies, particularly as to whether young star clusters may have the same origin as old globular clusters. In addition, extensive studies have revealed that the SSP scenario does not seem to hold for some intermediate-age and young star clusters either, thus making the origin of multiple stellar populations in star clusters even more complicated. Stellar population anomalies in numerous star clusters are well-documented, implying that the notion of star clusters as true SSPs faces serious challenges. In this review, we focus on stellar populations in massive clusters with different ages. We present the history and progress of research in this active field, as well as some of the most recent improvements, including observational results and scenarios that have been proposed to explain the observations. Although our current ability to determine the origin of multiple stellar populations in star clusters is unsatisfactory, we propose a number of promising projects that may contribute to a significantly improved understanding of this subject.

  17. Food for the ageing population

    NARCIS (Netherlands)

    Raats, M.M.; Groot, de C.P.G.M.; Staveren, van W.A.

    2008-01-01

    The world’s ageing population is increasing and food professionals will have to address the needs of older generations more closely in the future. This unique volume reviews the characteristics of the ageing population as food consumers, the role of nutrition in healthy ageing and the design of food

  18. Information Networking in Population Education.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand). Regional Office for Education in Asia and the Pacific.

    The rapidly increasing body of knowledge in population education has created the need for systematic and effective information services. Information networking entails sharing resources so that the information needs of all network participants are met. The goals of this manual are to: (1) instill in population education specialists a more…

  19. Assessment of ASEAN population programme.

    Science.gov (United States)

    1982-01-01

    The objectives of the 5th meeting of the ASEAN Heads of Population Program, held at Chiang Mai during November 1981, were the following: to discuss and consider the midterm reviews of some of the Phase 1 projects; to discuss and consider the ASEAN population experts' views on the progress made in the rest of the phase 1 projects; to discuss and consider the progress made in the implementation of the phase 2 projects; to discuss and consider the ASEAN population experts' recommendations on the ASEAN population program in the 1980s based on the report of the programming exercise submitted by the consultant in the expert group meeting; and to discuss administrative and other problems faced by the program implementors in the operationalization of the ongoing ASEAN population projects and provide appropriate directions to solve such problems. As a result of the programming exercise, the meeting established the directions for the future ASEAN population program and strongly recommended the continuation, intensification, and expansion of the ASEAN population program. A total of 12 projects comprise the ASEAN population program: 5 projects under phase 1 and 7 under phase 2. Under phase 1, 1 project has been completed, and the 1st parts of 2 other projects are in the process of implementation. Phase 2 projects, which started in September/October 1980, are all in the process of implementation. The following phase 1 projects are summarized: integration of population and rural development policies and programs; modular training for trainers of population and development agencies in ASEAN countries; multi-media support for population programs in the context of rural development in ASEAN countries; and migration in relation to rural development. The following phase 2 projects are also summarized: institutional development and exchange of personnel; women in development in ASEAN countries; and migration in relation to rural development. The following phase 2 projects are also

  20. Population in the classic economics

    Directory of Open Access Journals (Sweden)

    Adnan Doğruyol

    2013-02-01

    Full Text Available Growth subject in economics is an important factor of development. Classic economics ecole indicates the population as main variable which tender of growth. On the other hand T. R. Malthus is known as economist who regards population as a problem and brings up it among the classical economists. However, Adam Smith is an intellectual who discussed population problem earlier on the classic economics theory. According to Adam Smith one of the main factors that realise the growth is labour. In addition to population made it established. The aim of this study is analyzing the mental relationship between Malthus whose name has been identified with relation between population-growth and Smith who discussed this subject first time but put it off on process of theorisation.

  1. Genetic structure of chimpanzee populations.

    Directory of Open Access Journals (Sweden)

    Celine Becquet

    2007-04-01

    Full Text Available Little is known about the history and population structure of our closest living relatives, the chimpanzees, in part because of an extremely poor fossil record. To address this, we report the largest genetic study of the chimpanzees to date, examining 310 microsatellites in 84 common chimpanzees and bonobos. We infer three common chimpanzee populations, which correspond to the previously defined labels of "western," "central," and "eastern," and find little evidence of gene flow between them. There is tentative evidence for structure within western chimpanzees, but we do not detect distinct additional populations. The data also provide historical insights, demonstrating that the western chimpanzee population diverged first, and that the eastern and central populations are more closely related in time.

  2. Human Population: Fundamentals of Growth and Change.

    Science.gov (United States)

    Stauffer, Cheryl Lynn, Ed.

    This booklet focuses on eight elements of population dynamics: "Population Growth and Distribution"; "Natural Increase and Future Growth"; "Effect of Migration on Population Growth"; "Three Patterns of Population Change"; "Patterns of World Urbanization"; "The Status of Women";…

  3. Population problems and population research in a market economy.

    Science.gov (United States)

    Tian, X

    1994-01-01

    A market driven economy has many effects on population growth. The laws of social production were explicated by Marx and Engels, and Comrade Deng Xiaoping presents his views on China's socialist market economy and population problems in this article. Modern market economies have changed greatly over time. Before the 1960s, the focus of the interaction between population and economic change was in macro control. Since the 1960s, the focus shifted to micro control. Theories on maximum growth and neomodern population theory provide only a few useful elements. Cost-benefit analysis of child production functions, despite limitations, has universal appeal. Western theories with sound scientific evidence and Marxist theories should be examined and integrated within the Chinese experience. Two areas of concern in China are the spatial imbalance between population and economic development and an appropriate time period for any research activity. Scientific research in China will be advanced by careful integration of theory and practice, careful study of the Chinese experience, in-depth analysis, and bold, practical approaches which incorporate existing research results from the West. There are three dominant views of economic reforms. 1) Economic development plans should include a market economy. 2) Chinese population control would depend upon administrative means rather than market forces. 3) There are indirect ways in which the market affects population production. The last position is favored. The conclusions are made that family planning has been and continues to be a driving force in declining birth rates and that a focus on government population control does not discount the importance of the influence of economic factors on changes in the birth rate. Market forces are beginning to show their impact on people's choice in reproduction, and the impact is increasing. Reforms must be made appropriate to both the position and the negative influence of the market economy on

  4. Population information, education and communication.

    Science.gov (United States)

    1995-09-01

    Over the years UNFPA has used the information, education, and communication strategy to create awareness about population issues in more than 100 countries. The annual UNFPA publication The State of World Population has received worldwide media attention. Population issues are also aired through the annual World Population Day, which includes an international poster competition. Radio is used for spreading the message of population control but it could be employed more effectively given the 1.9 billion radio sets in the world. In Peru community-operated radio stations offer information on immunizations, reproductive health, and family planning. Some 20 countries have launched their own television programs in the form of mini-dramas to promote reproductive health and family planning. Mexico's family planning soap opera is highly popular in other Latin American countries. Multimedia campaigns are the most effective way of increasing public awareness about population and health-related issues. In Egypt the state-controlled television network is running a highly successful series of family planning mini-dramas. The country's contraceptive prevalence rate was nearly 50% in 1995 and rising. Similar successes have been reported in Mexico and Turkey. The growth of regional and international population information networks has been decisive in disseminating information. These include the UN Population Information Network (POPIN); the POPIN ASEAN for members of the Association of South-East Asian Nations (ASEAN); POPIN Africa; DOCPAL set up for Latin American countries; and PROLAP with the participation of 50 nongovernmental organizations. In the 1960s and 1970s population education also rapidly expanded in schools, and by the mid-1980s about 80 countries had population education in their schools. As of 1994 about 100 countries had such projects in schools. In addition, more attention is paid in schools to family planning, human sexuality, and gender issues. The major

  5. GWAS in an Amerindian ancestry population reveals novel systemic lupus erythematosus risk loci and the role of European admixture

    Science.gov (United States)

    Alarcón-Riquelme, Marta E.; Ziegler, Julie T.; Molineros, Julio; Howard, Timothy D.; Moreno-Estrada, Andrés; Sánchez-Rodríguez, Elena; Ainsworth, Hannah C.; Ortiz-Tello, Patricia; Comeau, Mary E.; Rasmussen, Astrid; Kelly, Jennifer A.; Adler, Adam; Acevedo-Vázquez, Eduardo; Cucho, Jorge Mariano; García-De la Torre, Ignacio; Cardiel, Mario H.; Miranda, Pedro; Catoggio, Luis; Maradiaga-Ceceña, Marco; Gaffney, Patrick; Vyse, Timothy; Criswell, Lindsey A.; Tsao, Betty P.; Sivils, Kathy L.; Bae, Sang-Cheol; James, Judith A.; Kimberly, Robert; Kaufman, Ken; Harley, John B.; Esquivel-Valerio, Jorge; Moctezuma, José F.; García, Mercedes A.; Berbotto, Guillermo; Babini, Alejandra; Scherbarth, Hugo; Toloza, Sergio; Baca, Vicente; Nath, Swapan K.; Salinas, Carlos Aguilar; Orozco, Lorena; Tusié-Luna, Teresa; Zidovetzki, Raphael; Pons-Estel, Bernardo A.; Langefeld, Carl D.; Jacob, Chaim O.

    2016-01-01

    OBJECTIVES Systemic lupus erythematosus (SLE) is a chronic autoimmune disease with a strong genetic component. Our aim was to perform the first genome-wide association study on individuals from the Americas enriched for Native American heritage. MATERIALS and METHODS We analyzed 3,710 individuals from four countries of Latin America and the Unites States diagnosed with SLE and healthy controls. Samples were genotyped with the HumanOmni1 BeadChip. Data of out-of-study controls was obtained for the HumanOmni2.5. Statistical analyses were performed using SNPTEST and SNPGWA. Data was adjusted for genomic control and FDR. Imputation was done using IMPUTE2, and HiBAG for classical HLA alleles. RESULTS The IRF5-TNPO3 region showed the strongest association and largest odds ratio (OR) (rs10488631, Pgcadj = 2.61×10−29, OR = 2.12, 95% CI: 1.88–2.39) followed by the HLA class II on the DQA2-DQB1 loci (rs9275572, Pgcadj = 1.11 × 10−16, OR = 1.62, 95% CI: 1.46–1.80; rs9271366, Pgcadj=6.46 × 10−12, OR = 2.06, 95% CI: 1.71–2.50). Other known SLE loci associated were ITGAM, STAT4, TNIP1, NCF2 and IRAK1. We identified a novel locus on 10q24.33 (rs4917385, Pgcadj =1.4×10−8) with a eQTL effect (Peqtl=8.0 × 10−37 at USMG5/miR1307), and describe novel loci. We corroborate SLE-risk loci previously identified in European and Asians. Local ancestry estimation showed that HLA allele risk contribution is of European ancestral origin. Imputation of HLA alleles suggested that autochthonous Native American haplotypes provide protection. CONCLUSIONS Our results show the insight gained by studying admixed populations to delineate the genetic architecture that underlies autoimmune and complex diseases. PMID:26606652

  6. Tibet's population: past and present.

    Science.gov (United States)

    Tu, D

    1997-08-01

    This article describes trends in population growth in Tibet during the Yuan Dynasty (1260-1287), the Qing Dynasty (1734-36), and during decennial periods after 1952, until 1994. Tibet was conquered by the Mongols who founded the Yuan Dynasty in the 13th century. During 1260-87, 3 enumerations revealed a total population of about 559,962 Tibetans, of whom 70,000 were lamas. Enumeration during 1734-36, revealed a total population of 941,151 Tibetans and 138,617 households. Tibet's population increased to about 1 million in 1951, an addition of 60,000 persons over 210 years. During 1952-59, the rate of population growth was fairly low at 0.94%. The total increase was 78,000 persons, or 11,000/year. Population increased from 1.15 million to about 1.23 million during 1952-59. The Dalai Lama went into exile with about 74,000 Tibetans in March 1959. Population during 1960-69 increased from 1.23 million to 1.48 million. The annual growth rate was 1.89%. Population increased by 252,500 persons, or 25.300/year. Reforms were carried out during this period. The region shifted from feudalism to socialism. Tibetans obtained free medical care and access to land. The birth rate was 25/1000, and the death rate was 10/1000. During 1970-79, both economic and population growth increased. Population increased from 1.48 million to 1.83 million, or a rate of annual growth of 2.14%. Population during this period increased by 348,500 persons, or 34,900/year. This was the fastest period of population growth. During 1980-89, the total fertility rate was maintained at around 4 children/woman, and family planning was implemented in urban areas. The annual rate of growth was 1.85%. Population increased by 367,000 persons, or 36,700/year. During 1990-94, the annual growth rate was 1.76 with a total increase of 159,000 persons, or 39,800/year.

  7. NIDI scenario. Strong population decline in China

    OpenAIRE

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario projects less population growth in Nigeria and sharp population decline in China.

  8. Scientists reinforce population control policies.

    Science.gov (United States)

    Myers, N

    1994-01-01

    In late October, 1993, 43 national scientific academies convened for 4 days in Delhi, India. This was the first time that so many academies had come together to discuss a topic of common interest: the controversial issue of population in conjunction with environment and development. The New Delhi gathering, known as the Population Summit, came up with a Conference Statement that earned the signatures of almost all participants. The statement proclaimed that ultimate success in dealing with global social, economic, and environmental problems cannot be achieved without stable world population. The goal should be zero population growth within the lifetime of our children. This goal will require prodigious planning efforts. If all couples were to decide right now that they would produce no more than 2 children, the world's population would still keep on growing through demographic momentum for another several decades. The source in shortest supply is probably not money but time. Said the Royal Society and the US National Academy of Sciences in 1993, "If current predictions of population growth prove accurate and patterns of human activity on the planet remain unchanged, science and technology may not be able to prevent irreversible degradation of the natural environment and continued poverty for much of the world ... Some of the environmental changes may produce irreversible damage to the Earth's capacity to sustain life. The future of our planet is in the balance." The Delhi statement was backed by 25 professional papers on subjects such as population history, energy, and water.

  9. Bangladesh. Population education programme reviewed.

    Science.gov (United States)

    1995-01-01

    The UNFPA (UN Population Fund)-funded population education program was reviewed last November 1994 in order to identify the emerging needs and requirements as well as chart the future directions of the program. The review was undertaken with the assistance of the CST SAWA Adviser on Population Education, Dr. D.M. de Rebello. Comprehensive literature review, and intensive discussions with government functionaries, educationists, teachers, students, UNFPA country director and staff and concerned officials of the World Bank and other UN agencies involved in the program served as the modalities for the review. The review looked into the current status of the school education sector and assessed the present progress of the population education program vis-a-vis its objectives and achievements. It also analyzed the issues and constraints in relation to institutionalization of the program, capacity building and integration of population education in curriculum and textbooks. Among the many recommendations, the review proposed further building up of national capacities at various levels; development of teaching/learning materials and textbooks for the new sectors; and intensification of good quality teacher education. Institutionalization of population education in the formal school system up to grade 12 and in technical and vocational education as well as the madrasah system and the introduction of population education in the Mass Non-formal Education Program were also proposed.

  10. Can human populations be stabilized?

    Science.gov (United States)

    Warren, Stephen G.

    2015-02-01

    Historical examples of demographic change, in China, Italy, Nigeria, Utah, Easter Island, and elsewhere, together with simple mathematics and biological principles, show that stabilizing world population before it is limited by food supply will be more difficult than is generally appreciated. United Nations population projections are wrong because they assume, in spite of the absence of necessary feedbacks, that all nations will converge rapidly to replacement-level fertility and thereafter remain at that level. Education of women and provision of contraceptives have caused dramatic reductions in fertility, but many groups, including some that are well-educated, maintain high fertility. Small groups with persistent high fertility can grow to supplant low-fertility groups, resulting in continued growth of the total population. The global average fertility rate could rise even if each country's fertility rate is falling. In some low-fertility European countries where deaths exceed births, the population continues to grow because of immigration. Producing more than two offspring is normal for all animal species with stable populations because their populations are limited by resources or predation rather than birth control. It may therefore be appropriate to view the growth of human population as the result not of excess fertility but rather of excess food.

  11. Soviet Marxism and population policy.

    Science.gov (United States)

    Vonfrank, A

    1984-01-01

    American demographers have maintained that Marxism, notably Soviet Marxism, is consistently pronatalist. The Soviet view is said to be that population growth is not a problem and that birth control policies in either developed or developing societies are to be rejected; the "correct" (i.e., socialist) socioeconomic structure is the true solution to alleged population problems. Such representations of Soviet thought greatly oversimplify the Soviet position as well as fail to discern the changes in Soviet thought that have been occurring. Since the 1960s Soviet writers have increasingly acknowledged that population growth is, to a considerable degree, independent of the economic base of society and that conscious population policies may be needed to either increase or decrease the rate of population growth. Even socialist societies can have population problems. And where population growth is too rapid, as in the developing countries, policies to slow such growth are needed because of the threat to economic development. However, the Soviets continue to stress that birth control policies must go hand-in-hand with social and economic development policies if they are to be effective.

  12. On the local stellar populations

    Science.gov (United States)

    Fuhrmann, Klaus; Chini, Rolf; Kaderhandt, Lena; Chen, Zhiwei

    2017-01-01

    We present a study of the local stellar populations from a volume-complete all-sky survey of the about 500 bright stars with distances less than 25 pc and down to main-sequence effective temperatures Teff ≥ 5300 K. The sample is dominated by a 93 per cent fraction of Population I stars, only 22 sources (5 per cent) are Population II stars, and 9 sources (2 per cent) are intermediate-disc stars. No source belongs to the halo. By following the mass of the stars instead of their light, the resulting subset of 136 long-lived stars distributes as 22 (16.2 per cent):6 (4.4 per cent):108 (79.4 per cent) for the Population II:intermediate disc:Population I, respectively. Along with the much larger scaleheight reached by Population II, this unbiased census of long-lived stars provides plain evidence for a starburst epoch in the early Milky Way, with the formation of a massive, rotationally supported, and dark Population II. The same conclusion arises from the substantial early chemical enrichment levels, exemplified here by the elements magnesium and iron, as it arises also from the local Population II white dwarfs. The kinematics, metallicity distribution functions, star formation rates, age-metallicity relations, the inventory of young stars, and the occurrence of blue straggler stars are discussed. A potentially new aspect of the survey is the possibility for substructure among the local Population II stars that may further subdivide into metal-poor and metal-rich sources.

  13. Population and Australian development assistance.

    Science.gov (United States)

    Jones, R

    1992-07-01

    Australia's position on international population issues is consistent with the major international statements on population: the World Population Plan of Action (1974), the Mexico City Declaration (1984), and the Amsterdam Declaration (1989). Australia's policy emphasizes the importance of population policies as an integral part of social, economic, and cultural development aimed at improving the quality of life of the people. Factors that would promote smaller families include improving economic opportunities, old-age security, education and health (particularly for women), as well as improving the accessibility and quality of family planning services. The quality of care approach is directly complementary to the Australian International Development Assistance Bureau (AIDAB)'s Women-In-Development Policy and its Health Policy, which stresses the theme of Women And Their Children's Health (WATCH). Australia's support for population programs and activities has increased considerably over the last few years. Total assistance for the year 1990/91 was around $7 million out of a total aid program of $1216 million. In recent years AIDAB has funded family planning activities or health projects with family planning components in a number of countries in the Asia-Pacific region. In the South Pacific region AIDAB has funded a reproductive health video project taking into consideration the cultural sensitivities and customs of the peoples of the region. AIDAB has supported a UN Population Fund project in Thailand that aims to strengthen the capacity of the National Statistical Office to collect population data. The US currently accounts for around 40% of all population-related development assistance to improve the health of women and children through family planning. The other major donors are Japan, the Scandinavian countries, and the Netherlands. Funding for population has been a relatively low percentage of overall development assistance budgets in OECD countries. In the

  14. Food production and population growth.

    Science.gov (United States)

    Pereira, H C

    1993-07-01

    Governments have frequently ignored the issue of population consumption exceeding the rates of renewal of natural resources. At the UN Conference on the Environment and Development in Rio de Janeiro, the issue of population growth was ignored in the agenda and action plan. In 1974, the UN World Population Conference suggested population stability would be possible if standards of living were raised. Industrialized nations spent half a century of active interference with the stability of global populations and failed to slow growth. 27 countries, mainly in tropical and subtropical zones, have an average cereal yield of under 1 ton per hectare, when improved seed and basic minimum fertilizer could yield 2 tons per hectare. Efforts to increase yields by the Consultative Group for International Agricultural research in 13 international centers resulted in global annual increases of about 50 million tons of grain (wheat and rice). Rainfed agriculture did not benefit as much because of climatic conditions. Where varieties of triticale, sorghum, millet, groundnuts, chick peas, cowpeas, beans, and cassava have helped increase food production, population growth has outstripped the gains. Agricultural fertilizers have been unfairly blamed for soil nutrient losses. Because of the age structure of population, the expected population growth can only be addressed through development of higher yields, new strains resistant to disease, and fertilizers. Slow release phosphates for tropical soils are needed. Shortages of domestic fuel divert much needed farmyard manure and composted crop residues. About 400 million tons of dung are thus wasted annually; food grain harvests are thus reduced by 14 million tons. About 50% of the 1133 million poorest people will live in Asia and another 25% will live in Sub-Saharan Africa, living on a total degraded area of 1219 million hectares. Imbalance between food supply and population need to be addressed on an effective international scale.

  15. Population samples and genotyping technology.

    Science.gov (United States)

    Mack, S J; Sanchez-Mazas, A; Single, R M; Meyer, D; Hill, J; Dron, H A; Jani, A J; Thomson, G; Erlich, H A

    2007-04-01

    The 14th International HLA (human leukocyte antigen) Immunogenetics Workshop (14th-IHIWS) Biostatistics and Anthropology/Human Genetic Diversity project continues the population sampling, genotype data generation, and biostatistic analyses of the 13th International Histocompatibility Workshop Anthropology/Human Genetic Diversity Component, with the overall goal of further characterizing global HLA allele and haplotype diversity and better describing the relationships between major histocompatibility complex diversity, geography, linguistics, and population history. Since the 13th Workshop, new investigators have and continue to be recruited to the project and new high-resolution class I and class II genotype data are being generated for 112 population samples from around the world.

  16. Sampling hard to reach populations.

    Science.gov (United States)

    Faugier, J; Sargeant, M

    1997-10-01

    Studies on 'hidden populations', such as homeless people, prostitutes and drug addicts, raise a number of specific methodological questions usually absent from research involving known populations and less sensitive subjects. This paper examines the advantages and limitations of nonrandom methods of data collection such as snowball sampling. It reviews the currently available literature on sampling hard to reach populations and highlights the dearth of material currently available on this subject. The paper also assesses the potential for using these methods in nursing research. The sampling methodology used by Faugier (1996) in her study of prostitutes, HIV and drugs is used as a current example within this context.

  17. Inherent randomness of evolving populations.

    Science.gov (United States)

    Harper, Marc

    2014-03-01

    The entropy rates of the Wright-Fisher process, the Moran process, and generalizations are computed and used to compare these processes and their dependence on standard evolutionary parameters. Entropy rates are measures of the variation dependent on both short-run and long-run behaviors and allow the relationships between mutation, selection, and population size to be examined. Bounds for the entropy rate are given for the Moran process (independent of population size) and for the Wright-Fisher process (bounded for fixed population size). A generational Moran process is also presented for comparison to the Wright-Fisher Process. Results include analytic results and computational extensions.

  18. The Veteran Population Projection 2014

    Data.gov (United States)

    Department of Veterans Affairs — VetPop2014 is an actuarial projection model developed by the Office of the Actuary (OACT) for Veteran population projection from Fiscal Year FY2014 to FY2043. Using...

  19. Population genetics without intraspecific data

    DEFF Research Database (Denmark)

    Thorne, Jeffrey L; Choi, Sang Chul; Yu, Jiaye

    2007-01-01

    A central goal of computational biology is the prediction of phenotype from DNA and protein sequence data. Recent models of sequence change use in silico prediction systems to incorporate the effects of phenotype on evolutionary rates. These models have been designed for analyzing sequence data...... populations, and parameters of interspecific models should have population genetic interpretations. We show, with two examples, how population genetic interpretations can be assigned to evolutionary models. The first example considers the impact of RNA secondary structure on sequence change, and the second...... reflects the tendency for protein tertiary structure to influence nonsynonymous substitution rates. We argue that statistical fit to data should not be the sole criterion for assessing models of sequence change. A good interspecific model should also yield a clear and biologically plausible population...

  20. Population and resources in Mauritius.

    Science.gov (United States)

    Royle, S A

    1995-05-01

    "The island of Mauritius was facing a crisis by the 1950s as the relationship between its population and resources became unbalanced....A two-pronged strategy was set in place to change the relationship between population and resources. Firstly, an aggressive family-planning policy was established, reducing population growth. Secondly, the economy was diversified with tourism, financial services and, especially, manufacturing in the Mauritius Export Processing Zone, creating extra finance and resources. The changes have not been cost-free but Mauritius ends the century, not as a classic case of overpopulation, but more [as] a model micro-state that has overcome many population and resource problems, largely through its own efforts." excerpt

  1. Wolf population genetics in Europe

    DEFF Research Database (Denmark)

    Hindrikson, Maris; Remm, Jaanus; Pilot, Malgorzata

    2017-01-01

    The grey wolf (Canis lupus) is an iconic large carnivore that has increasingly been recognized as an apex predator with intrinsic value and a keystone species. However, wolves have also long represented a primary source of human–carnivore conflict, which has led to long-term persecution of wolves......, resulting in a significant decrease in their numbers, genetic diversity and gene flow between populations. For more effective protection and management of wolf populations in Europe, robust scientific evidence is crucial. This review serves as an analytical summary of the main findings from wolf population...... (Y chromosome) and biparental [autosomal microsatellites and single nucleotide polymorphisms (SNPs)]. To describe large-scale trends and patterns of genetic variation in European wolf populations, we conducted a meta-analysis based on the results of previous microsatellite studies and also included...

  2. Modeled population exposures to ozone

    Data.gov (United States)

    U.S. Environmental Protection Agency — Population exposures to ozone from APEX modeling for combinations of potential future air quality and demographic change scenarios. This dataset is not publicly...

  3. Population Issues. Resources in Technology.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    Presents information about the problems caused by increasing population. Discusses the environmental impact and the ways that technology can be used to solve problems of overpopulation. Includes possible student outcomes and a student quiz. (JOW)

  4. Population Issues. Resources in Technology.

    Science.gov (United States)

    Technology Teacher, 1991

    1991-01-01

    Presents information about the problems caused by increasing population. Discusses the environmental impact and the ways that technology can be used to solve problems of overpopulation. Includes possible student outcomes and a student quiz. (JOW)

  5. The Veteran Population Projection 2014

    Data.gov (United States)

    Department of Veterans Affairs — VetPop2014 is an actuarial projection model developed by the Office of the Actuary (OACT) for Veteran population projection from Fiscal Year FY2014 to FY2043. Using...

  6. Population genetic structure and ecotoxicology.

    OpenAIRE

    Guttman, S I

    1994-01-01

    Electrophoretic analyses of population genetic structure, both in the laboratory and in the field, have documented significant shifts in allozyme genotype frequencies in a variety of aquatic taxa as a result of environmental impacts. Studies are documented which indicate that contaminants may select for individuals with tolerant allozyme genotypes, causing the potential loss of individuals with sensitive genotypes. This may diminish the genetic variability and fitness of affected populations ...

  7. Introduction. Population and the environment.

    Science.gov (United States)

    Clarke, J; Zaba, B

    1992-01-01

    The complexity of the interrelationships between population growth and environmental concerns is often obscured when the global picture is presented. The variety and complexity of population-environment associations varies with spatial aggregation; analysis is needed at all levels. Of the many organizations involved in researching and discussing these associations, the International Social Science Council established a working committee on population and the environment, which held a symposium in January 1991. 9 papers were the topic of discussions and are summarized in this article. Attention was focused on pollution emissions and population growth by the environmental scientist Paul Harrison. The increased demand for water was discussed as it related to rapid urbanization and changes in agricultural production and industrial development policies. David Noin's paper was on the increased occurrence of natural disasters and mortality, i.e., cyclones and floods. The population densities surrounding areas of natural disasters excluding droughts have increased and contributed to greater impacts. Alina Potrykowska and Roger Bivend provided information on the trends and spatial patterns of mortality in Poland. Mortality increases have appeared during the course of industrialization. Data for Poland on environmental variables such as dust and gas emissions, volume of untreated waste, and hazardous waste are available for 49 voivodships. The most polluted areas show a statistically significant relationships with high morality. Ken Wilson presented his views on the contradiction that African famines did not cause population decline. The possible interpretations are misinterpretation of data, inappropriate scales of measurement, and a misspecification that social, economic, and political changes will improve the population environment links. Matthew Lockwood presented his findings on northern Nigeria that migration is an important cause of high density population, and that

  8. Population cycles in small rodents.

    Science.gov (United States)

    Krebs, C J; Gaines, M S; Keller, B L; Myers, J H; Tamarin, R H

    1973-01-05

    We conclude that population fluctuations in Microtus in southern Indiana are produced by a syndrome of changes in birth and death rates similar to that found in other species of voles and lemmings. The mechanisms which cause the changes in birth and death rates are demolished by fencing the population so that no dispersal can occur. Dispersal thus seems critical for population regulation in Microtus. Because most dispersal occurs during the increase phase of the population cycle and there is little dispersal during the decline phase, dispersal is not directly related to population density. Hence the quality of dispersing animals must be important, and we have found one case of increased dispersal tendency by one genotype. The failure of population regulation of Microtus in enclosed areas requires an explanation by any hypothesis attempting to explain population cycles in small rodents. It might be suggested that the fence changed the predation pressure on the enclosed populations. However, the fence was only 2 feet (0.6 meter) high and did not stop the entrance of foxes, weasels, shrews, or avian predators. A striking feature was that the habitat in the enclosures quickly recovered from complete devastation by the start of the spring growing season. Obviously the habitat and food quality were sufficient to support Microtus populations of abnormally high densities, and recovery of the habitat was sufficiently quick that the introduction of new animals to these enclosed areas resulted in another population explosion. Finally, hypotheses of population regulation by social stress must account for the finding that Microtus can exist at densities several times greater than normal without "stress" taking an obvious toll. We hypothesize that the prevention of dispersal changes the quality of the populations in the enclosures in comparison to those outside the fence. Voles forced to remain in an overcrowded fenced population do not suffer high mortality rates and continue

  9. Canada's population: growth and dualism.

    Science.gov (United States)

    Beaujot, R P

    1978-04-01

    In Canada the current 1.3% population growth rate is causing some concern. Those concerned argue that such a rate of growth in combination with high levels of consumption could jeopardize the country's resource base and its comfortable style of living. Many Canadians are questioning high levels of immigration, for now that the fertility level is below replacement level, net immigration contributes substantially to population growth (over 1/3 in 1976). The growing proportion of non-Europeans among recent immigrants is causing resentment, and, in a tight job market, immigrants are regarded as threats to the World War 2 baby boom cohort who are now at working ages. The baby boom generation also puts stress on housing and health services, and it will increase the need for pension checks as it ages. Although French fertility is no longer high and immigration is no longer dominated by the British, the French group's 200-year struggle to preserve its identity continues on in the current effort of the Quebec government to enforce the use of French language by law within that province. Geography and climate dictate another demographic fact that divides the country and pervades its history. In addition to intense regionalism, uneven population distribution is responsible for 2 other concerns: the rapid growth of several already large cities and depopulation of many small communities. Focus in this discussion is on Canada's population growth in the past and as projected for the future, historical and current fertility, mortality and immigration trends, the search for a new immigration policy, the impact of the baby boom generation on the population's age structure and the problems this creates, and recent shifts in population distribution and in the country's ethnic and linguistic makeup. The population policy proposals evolved thus far involve to a great extent the use of immigration as a lever for achieving given population objectives.

  10. Structure of African elephant populations

    DEFF Research Database (Denmark)

    Siegismund, H R; Arctander, P

    1996-01-01

    The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion that there was a ......The structure of elephant populations from east and south Africa has been analyzed by Georgiadis et al. (1994) on the basis of restriction site variation of mitochondrial DNA. They used F statistics based on identity by descent in tests for subdivision and reached the conclusion...... that there was a significant differentiation at the continental level, but that "populations were not significantly subdivided at the regional levels." The data were reanalyzed by Monte-Carlo permutation tests where population subdivision was tested by using F statistics based on partitioning the total haplotype diversity...... among populations. This resulted in identical conclusions at the continental level, but revealed in addition a significant subdivision at the regional level indicating haplotype frequency differences among the populations....

  11. Quasispecies theory for finite populations

    Science.gov (United States)

    Park, Jeong-Man; Muñoz, Enrique; Deem, Michael W.

    2010-01-01

    We present stochastic, finite-population formulations of the Crow-Kimura and Eigen models of quasispecies theory, for fitness functions that depend in an arbitrary way on the number of mutations from the wild type. We include back mutations in our description. We show that the fluctuation of the population numbers about the average values is exceedingly large in these physical models of evolution. We further show that horizontal gene transfer reduces by orders of magnitude the fluctuations in the population numbers and reduces the accumulation of deleterious mutations in the finite population due to Muller’s ratchet. Indeed, the population sizes needed to converge to the infinite population limit are often larger than those found in nature for smooth fitness functions in the absence of horizontal gene transfer. These analytical results are derived for the steady state by means of a field-theoretic representation. Numerical results are presented that indicate horizontal gene transfer speeds up the dynamics of evolution as well.

  12. The Soviet Union and population: theory, problems, and population policy.

    Science.gov (United States)

    Di Maio, A J

    1980-04-01

    Until the important public dialog on 3rd World population issues began in the Soviet Uuion in 1965, ideological limitations and bureaucratic interests prevented policy makers from recognizing the existence of a world of national "population problem." Since then, freer discussions of the Soviet Union's surprising decline in birthrate and labor shortages have led to serious policy questions. Conflicting policy goals, however, have resulted in only modest pronatalist policies. The Soviet population problem is a result of interregional disparities in population growth rates between the highly urbanized Soviet European populations with low birth rates and the least urbanized Central Asians with dramatically higher birth rates. As a result, these essentially Muslim people will provide the only major increases in labor resources and an increasing percentage of Soviet armed forces recruits. Policy planners are thus faced with difficult options. Current policies stressing technological transfers from the west and greater labor productivity, however, are unlikely to solve further labor shortages and regional imbalances. Ultimately, nonEuropana regions will be in an improved bargaining position for more favorable nationwide economic policies and for a greater role in policy planning.

  13. Population priorities: the challenge of continued rapid population growth.

    Science.gov (United States)

    Turner, Adair

    2009-10-27

    Rapid population growth continues in the least developed countries. The revisionist case that rapid population could be overcome by technology, that population density was advantageous, that capital shallowing is not a vital concern and that empirical investigations had not proved a correlation between high population growth and low per capita income was both empirically and theoretically flawed. In the modern world, population density does not play the role it did in nineteenth-century Europe and rates of growth in some of today's least developed nations are four times than those in nineteenth-century Europe, and without major accumulation of capital per capita, no major economy has or is likely to make the low- to middle-income transition. Though not sufficient, capital accumulation for growth is absolutely essential to economic growth. While there are good reasons for objecting to the enforced nature of the Chinese one-child policy, we should not underestimate the positive impact which that policy has almost certainly had and will have over the next several decades on Chinese economic performance. And a valid reticence about telling developing countries that they must contain fertility should not lead us to underestimate the severely adverse impact of high fertility rates on the economic performance and prospects of many countries in Africa and the Middle East.

  14. Population growth and its implications

    Directory of Open Access Journals (Sweden)

    Badii, M. H.

    2005-01-01

    Full Text Available Human populations have grown at an unprecedented rate over the past three centuries. By 2001, the world population stood at 6.2 billion people. If the current trend of 1.4 % per year persists, the population will double in 51years. Most of that growth will occur in the less developed countries of Asia, Africa, and Latin America. There is a serious concern that the number of humans in the world and our impact on the environment will overload the life support systems of the earth. The crude birth rate is the number of births in a year divided by the average population. A more accurate measure of growth is the general fertility rate, which takes into account the age structure and fecundity of the population. The crude birth rate minus the crude death rate gives the rate of natural increase. When this rate reaches a level at which people are just replacing themselves, zero population growth is achieved. In the more highly developed countries of the world, growth has slowed are even reversed in recent years so that without immigration from other areas, population would be declining. The change from high birth and death rates that accompanies in industrialization is called a demographic transition. Many developing nations have already begun this transition. Death rates have fallen, but birth rates remain high. Some demographers believe that as infant mortality drops and economic development progresses so that people in these countries can be sure of secure future, they will complete the transition to a stable population or a high standard living. While larger populations bring many problems, they also may be a valuable resource of energy, intelligence, and enterprise that will make it possible to overcome resource limitation problems. A social just view argues that a more equitable distribution of wealth might reduce both excess population growth and environmental degradation. We have many more options now for controlling fertility than were available

  15. Population data of five genetic markers in the Turkish population: comparison with four American population groups.

    Science.gov (United States)

    Kurtuluş-Ulküer, M; Ulküer, U; Kesici, T; Menevşe, S

    2002-09-01

    In this study, the phenotype and allele frequencies of five enzyme systems were determined in a total of 611 unrelated Turkish individuals and analyzed by using the exact and the chi 2 test. The following five red cell enzymes were identified by cellulose acetate electrophoresis: phosphoglucomutase (PGM), adenosine deaminase (ADA), phosphoglucose isomerase (PGI), adenylate kinase (AK), and 6-phosphogluconate dehydrogenase (6-PGD). The ADA, PGM and AK enzymes were found to be polymorphic in the Turkish population. The results of the statistical analysis showed, that the phenotype frequencies of the five enzyme under study are in Hardy-Weinberg equilibrium. Statistical analysis was performed in order to examine whether there are significant differences in the phenotype frequencies between the Turkish population and four American population groups. This analysis showed, that there are some statistically significant differences between the Turkish and the other groups. Moreover, the observed phenotype and allele frequencies were compared with those obtained in other population groups of Turkey.

  16. Analysis of Population Dynamics in World Economy

    OpenAIRE

    Martin, Gress

    2011-01-01

    Population dynamics is an important topic in current world economy. The size and growth of population have an impact on economic growth and development of individual countries and vice versa, economic development influences demographic variables in a country. The aim of the article is to analyze historical development of world population, population stock change and relations between population stock change and economic development.

  17. Population growth and economic growth.

    Science.gov (United States)

    Narayana, D L

    1984-01-01

    This discussion of the issues relating to the problem posed by population explosion in the developing countries and economic growth in the contemporary world covers the following: predictions of economic and social trends; the Malthusian theory of population; the classical or stationary theory of population; the medical triage model; ecological disaster; the Global 2000 study; the limits to growth; critiques of the Limits to Growth model; nonrenewable resources; food and agriculture; population explosion and stabilization; space and ocean colonization; and the limits perspective. The Limits to Growth model, a general equilibrium anti-growth model, is the gloomiest economic model ever constructed. None of the doomsday models, the Malthusian theory, the classical stationary state, the neo-Malthusian medical triage model, the Global 2000 study, are so far reaching in their consequences. The course of events that followed the publication of the "Limits to Growth" in 1972 in the form of 2 oil shocks, food shock, pollution shock, and price shock seemed to bear out formally the gloomy predictions of the thesis with a remarkable speed. The 12 years of economic experience and the knowledge of resource trends postulate that even if the economic pressures visualized by the model are at work they are neither far reaching nor so drastic. Appropriate action can solve them. There are several limitations to the Limits to Growth model. The central theme of the model, which is overshoot and collapse, is unlikely to be the course of events. The model is too aggregative to be realistic. It exaggerates the ecological disaster arising out of the exponential growth of population and industry. The gross underestimation of renewable resources is a basic flaw of the model. The most critical weakness of the model is its gross underestimation of the historical trend of technological progress and the technological possiblities within industry and agriculture. The model does correctly emphasize

  18. Political economy of population growth.

    Science.gov (United States)

    Mehta, S; Mehta, H S

    1987-01-01

    Tracing the origin of political economy as a class-science, this paper focuses on the political economy of population growth. Exposing the limitations of Malthusian ideas and their invalidity even for the capitalist economies, it discusses the subsequent revival of the Malthusian model during the period of de-colonization and the misinterpretation of the relationship between population growth and development in the developing and developed countries. Taking India, China, and Japan as some case studies, the paper examines the relationship between birth rate levels and some correlates. It elaborates on the Indian experience, emphasizing the association of population growth with poverty and unemployment and lays bare some of the hidden causes of these phenomena. The authors examine some interstate variations in India and identify constraints and prospects of the existing population policy. The paper proposes outlines of a democratic population policy as an integral part of India's development strategy which should recognize human beings not simply as consumers but also as producers of material values. It pleads for 1) restructuring of property relations; 2) bringing down the mortality rates and raising of the literacy levels, especially among females; and 3) improving nutritional levels, as prerequisites for bringing down birth rates.

  19. Chinese Population and Environment Pressure

    Institute of Scientific and Technical Information of China (English)

    刘智慧

    2012-01-01

    China is typical country for the change of environment,which is the center area and pressure about population.It has 12 billion in 2000,which is the one fifth of the total world population.And humanists think the population will increase to 16 billion till zoos.Is has increase 7 billion between 1950 to 2000 that beyond the total number of the whole people at the be ginning of the industry reductions.The increasing of the huge population' s extrading which is area is nearly equal to the east of America,the Yangtze and the Huanghe valley.In the west of China it is filled with desert and mountain ranges,and the south it is limited to the resist of other civilization,while the population of agriculture is more and more dense that Our ancestors has till aged for thousands of years.In fact,China has already become an excessivepacked “island”.

  20. Population dynamics in variable environments

    CERN Document Server

    Tuljapurkar, Shripad

    1990-01-01

    Demography relates observable facts about individuals to the dynamics of populations. If the dynamics are linear and do not change over time, the classical theory of Lotka (1907) and Leslie (1945) is the central tool of demography. This book addresses the situation when the assumption of constancy is dropped. In many practical situations, a population will display unpredictable variation over time in its vital rates, which must then be described in statistical terms. Most of this book is concerned with the theory of populations which are subject to random temporal changes in their vital rates, although other kinds of variation (e. g. , cyclical) are also dealt with. The central questions are: how does temporal variation work its way into a population's future, and how does it affect our interpretation of a population's past. The results here are directed at demographers of humans and at popula­ tion biologists. The uneven mathematical level is dictated by the material, but the book should be accessible to re...

  1. Population policy: major party positions.

    Science.gov (United States)

    Betts, K

    1998-01-01

    This article identifies the major political party positions on population policy (PP) in Australia. Australia has the Governing Coalition, comprised of the Liberal and National Parties, and the Australian Labor Party (ALP), the main opposition party. The ALP adopted a PP at its national conference in 1998. The Government Minister for Immigration and Multicultural Affairs (DIMA) does not view a PP as a need. The ALP policy identifies the need to decide on a long term sustainable population size as determined within a PP framework. The visa classification system needs to reflect national priorities. Labor will support a fair refugee and humanitarian program. Skilled labor migration must be linked with labor market needs. Business migration is a means of transferring resources and technology to Australia. The DIMA Minister announced the target intake of 80,000 visa immigrants in 1998- 99, which would produce a peak population of about 23 million in 2050. Settler arrivals from New Zealand would increase population size. A group of scientists and scholars published their recommendations about development of a PP. The Minister of DIMA's defense of the lack of a PP is included in this publication. Labor in several publications indicates support for a larger immigration intake, or an adjustment of the intake within the existing numbers. The Prime Minister, who supports the concept of multiculturalism, argues that people must accept immigration policy. Politics today are more divided over the origin and future of the nation than population size issues.

  2. Population problem in third world.

    Science.gov (United States)

    Joshi, N C

    1979-04-01

    Since numerous variables influence this growth rate, a holistic approach to the problem is mandatory. Fertility rates in developing countries remain high, not as a result of irrational behavior on the part of the people living in these countries, but as a result of their rational response to high infant mortality rates. Fertility rates will remain high unless the educational, health, and social environment in which these families live is improved. Economic development and population growth are intimately related. Development reduces the death rate resulting in increased population growth, which in turn reduces per capita income. In the developed nations, economic development occurred along with the development of new technologies and the reduction in mortality; therefore, population growth created an effective demand which further stimulated economic development. In developing countries the situation is different. Reduced mortality, the introduction of labor saving technology, and the high consumption aspirations derived from contact with capitalistic countries, have preceded economic development. Given the highly complex nature of the population problem, efforts must be made on many fronts including: 1) family planning promotion; 2) improvements in education, health, and social conditions for high fertility populations; 3) enhancement of worker skills; 4) rapid progress in technology; 5) greater capital accumulation and 5) economic reorganization.

  3. Genealogical histories in structured populations.

    Science.gov (United States)

    Kumagai, Seiji; Uyenoyama, Marcy K

    2015-06-01

    In genealogies of genes sampled from structured populations, lineages coalesce at rates dependent on the states of the lineages. For migration and coalescence events occurring on comparable time scales, for example, only lineages residing in the same deme of a geographically subdivided population can have descended from a common ancestor in the immediately preceding generation. Here, we explore aspects of genealogical structure in a population comprising two demes, between which migration may occur. We use generating functions to obtain exact densities and moments of coalescence time, number of mutations, total tree length, and age of the most recent common ancestor of the sample. We describe qualitative features of the distribution of gene genealogies, including factors that influence the geographical location of the most recent common ancestor and departures of the distribution of internode lengths from exponential.

  4. Keynes, population, and equity prices.

    Science.gov (United States)

    Tarascio, V J

    1985-01-01

    Keynes in 1937 examined the phenomenon of the Great Depression from a longrun perspective in contradiction to the "General Theory," where the focus was on the shortrun. "Some Economic Consequences of a Declining Population," Keynes' article, reveals the context in which the "General Theory" was written. In the "General Theory," the focus is on short-term fluctuations, i.e., business cycles, but Keynes fails to provide any theoretical explanation as to why the depression of the 1930s was so severe and intractable. In the 1937 article, the depression is seen as the result of the combined effects of a decline in longrun growth due to population growth decline and a shortrun cyclical decline, together producing severe economic consequences. What is important for the purposes of this discussion is the implication, within the context of the 1937 article, that not only was the stock market crash of 1929 related to population change (with its accompanying collapse in expectations) but that, in general, changes in the rate of growth of population are accompanied by stock price movements in the same direction. The remainder of the discussion is devoted to a simple empirical test of this relationship. The data used are population size (POP), defined as the total residential population in the US from 1870-1979, and the Standard and Poor 500 Stock index (SP) for the corresponding 109-year period. In addition, a 3rd series was constructed, a price deflated Standard and Poor index (RSP) with a base period of 1870, to account for possible inflationary distortion of the index. The empirical results do not invalidate the hypothesis that population growth rates affect equity markets. In fact, there seems to be strong evidence that they are related in a manner suggestive of Keynes' intutition, namely, that the stock market crash of 1929 was due to factors more fundamental than those often perceived from a shortrun perspective. According to Keynes (1937), population is the most

  5. An Introduction to Population Protocols

    Science.gov (United States)

    Aspnes, James; Ruppert, Eric

    Population protocols are used as a theoretical model for a collection (or population) of tiny mobile agents that interact with one another to carry out a computation. The agents are identically programmed finite state machines. Input values are initially distributed to the agents, and pairs of agents can exchange state information with other agents when they are close together. The movement pattern of the agents is unpredictable, but subject to some fairness constraints, and computations must eventually converge to the correct output value in any schedule that results from that movement. This framework can be used to model mobile ad hoc networks of tiny devices or collections of molecules undergoing chemical reactions. This chapter surveys results that describe what can be computed in various versions of the population protocol model.

  6. Literacy and World Population. Population Bulletin No. 2, Vol. 30.

    Science.gov (United States)

    Population Reference Bureau, Inc., Washington, DC.

    This bulletin examines aspects of world literacy with regard to population projects and family planning. Discussion includes the presentation of perspectives, definitions, and statistics concerning literacy. The role of literacy in economic development is examined; specific topics include adult and school-age illiteracy, rural and urban…

  7. Rapid population increase in an introduced muskox population, West Greenland

    Directory of Open Access Journals (Sweden)

    Carsten Riis Olesen

    1993-10-01

    Full Text Available In 1962 and 1965, 27 (13 and 14 muskox yearlings were translocated from East Greenland (71°N to the Angujaartorfiup Nunaa range in West Greenland (67°N. Angujaartorfiup Nunaa is a 6600 km2 icefree, continental area where caribou are indigenous. The climate is strictly continental with a minimum of precipitation but with abundant vegetation. Aerial surveys in 1990 documented that the muskox population has increased to 2600 heads despite quota-based harvesting since 1988. The annual quota was 200, 300 and 400 for 1988, 1989 and 1990, respectively. Distribution of muskoxen shows a significant preference for low altitude habitats southeast of Kangerlussuaq Airport and around Arnangarnup Qoorua (Paradise valley. Annual population increment averages 30% and the calf crop is around 24% of the population. Yearling recruitment in the population reveals that calf mortality during winter is very limited. About half of the 1-year-old females are served and they eventually give birth to their first calf when they turn 2 years old. With half of the 2-year-old females reproducing, the calf/cow ration ranges between 0.9 and 1.0.

  8. The Population Commission and IUSSP.

    Science.gov (United States)

    Lebrun, M; Brass, W

    1986-01-01

    The United Nations (UN) and the International Union for the Scientific Study of Population (IUSSP) have cooperated since the 1940s. In 1927 an International Population Conference in Geveva established a permanent Population Union to cooperate with the population activities of the League of Nations. The 2 institutions' successors, IUSSP and the United Nations (UN), developed close and productive linkages, collaborating to create a Multilingual Demographic Dictionary, published in English, French, Russian, and Spanish and in many other languages. Meanwhile the Union, at the request of UNESCO, prepared a pioneering study attempting to define the cultural factors affecting developing country fertility in the context of the demographic transition, In 1966 the Union and the UN collaborated to develop criteria for internationally comparable studies in fertility and family planning (FP). The resulting monograph served as a reference for many fertility studies, including the World Fertility Survey. Another study on the impact of FP programs on fertility, resulted in the organization of expert meetings and the production of a manual and monographs on FP program evaluation. There was futher cooperation in a study on mortality, internal migration and international migration, resulting in manuals on methods of analysing internal migration and indirect measures of emigration, among other things. The 1954 Wold Population Conference (WPC) and the 1965 UN WPC were organized by the UN collaborating with the Union, and the Union administered the funds used to bring developing country delegates to the Conference. Subsequent WPCs at Bucharest and Mexico City were political in nature, bu the Union contributed to both a report outlining demographic research needs. The Union also assisted the UN in organizing a series of regional population conferences, and its Committee on Demographic Instruction prepared a report for UNESCO on teaching demography, and cooperated with the Secretariat in

  9. A new population of FRIIs?

    Science.gov (United States)

    Sambruna, Rita

    2006-10-01

    Unification scenarios explain various flavors of radio galaxies and quasars with orientation-dependent obscuration effects. Type-2 FRII galaxies contain a quasar seen through a dusty molecular torus aligned with the radio jet. However, there exist a population of FRIIs, found with Spitzer, that does not fit into this scheme. These FRIIs exhbit high-excitation nuclear optical emission lines, but weak 15um luminosities. One possibility is very large obscuration; alternatively, they may be a genuinely different population. XMM spectroscopy and Chandra imaging will discriminate between the two scenarios.

  10. Models of ungulate population dynamics

    Directory of Open Access Journals (Sweden)

    L. L. Eberhardt

    1991-10-01

    Full Text Available A useful theory for analyzing ungulate population dynamics is available in the form of equations based on the work of A. J. Lotka. Because the Leslie matrix model yields identical results and is widely known, it is convenient to label the resulting equations as the "Lotka-Leslie" model. The approach is useful for assessing population trends and attempting to predict the outcomes of various management actions. A broad list of applications to large mammals, and two examples specific to caribou are presented with a simple spreadsheet approach to calculations.

  11. Cancer patterns in Inuit populations

    DEFF Research Database (Denmark)

    Melbye, M.; Friborg, Jeppe Tang

    2008-01-01

    Inuit people inhabit the circumpolar region, with most living in Alaska, northwest Canada, and Greenland. Although malignant diseases were believed to be almost non-existent in Inuit populations during the beginning of the 20th century, the increasing life expectancy within these populations showed...... to be responsible for this pattern. During the second half of the 20th century, Inuit societies underwent major changes in lifestyle and living conditions, and the risk of lifestyle-associated tumours, especially cancers of the lung, colon, and breast, increased considerably after changes in smoking, diet...

  12. The Why and How of Population Education

    Science.gov (United States)

    Seffrin, John R.

    1975-01-01

    Discusses the importance of instructional programs concerning population education and describes population growth in the United States, the biological reasons for the overpopulation problem, and the role of the health educator in population education. (BD)

  13. The Why and How of Population Education

    Science.gov (United States)

    Seffrin, John R.

    1975-01-01

    Discusses the importance of instructional programs concerning population education and describes population growth in the United States, the biological reasons for the overpopulation problem, and the role of the health educator in population education. (BD)

  14. Seminar on Egypt population policy.

    Science.gov (United States)

    Kantner, J F

    1984-01-01

    The information and viewpoints presented at the Seminar on Egypt Population Policy held in Cairo on October 16-18 were summariezed and critically assessed. The seminar was organized by the International Union for the Scientific Study of Population's Committee on the Utilization ofDemographic Knowlege in Policy Formulation and Planning for the purpose of assessing the policy making the utility of social science and demographc knowledge with specific reference to Egypt's family planning program. The seminar was attended by demographers, social scientists, and experienced policy makers, and the discussion was highly focused. Seminar papers and discussions sought to clarify Egypt's current demographic situation, attempted to use sample survey data to identifyfertility determinants, analyzed Egypt's policyresponses to the population problem, assessed the national family planning program, identified the type of knowledge available for policy making, and noted areas where policy relevant information is lacking. Evidence presented at the seminar indicated that Egyptian fertility is still high and that corrected the total fertility rate for 1980 was close to 6. Since, 1960, fertility declined in all regions of the country, but between 1976-80 the decline decelerated. This deceleration appears to be a temporary phenonemon. There is evidence that the age at marriage is increasing, that the population is motivated to use contraception when desired family size is reached, that contraceptive use is cost sensitive, and that the overall decline in fertility since the 1960s occurred in all parts of the country. Papers which presented analyses of fertility determinants, based on sample survey data, provided little useful insight for policy formulation. The studies indicate that the impact of family planning services on different segments of the population varies, and that these impacts may be increased if social and economic development persists. The preception of the population

  15. Gender, Education and Population Flows

    DEFF Research Database (Denmark)

    Bennike, Kathrine Bjerg; Faber, Stine Thidemann; Nielsen, Helene Pristed

    During the Danish Presidency for the Nordic Council of Ministers in 2015, attention was drawn towards challenges and best practice examples in relation to gender, education and population flows in peripheral areas throughout the Nordic countries - Norway, Denmark, Sweden, Finland, Iceland...

  16. Reproductive effort in viscous populations

    NARCIS (Netherlands)

    Pen, Ido

    2000-01-01

    Here I study a kin selection model of reproductive effort, the allocation of resources to fecundity versus survival, in a patch-structured population. Breeding females remain in the same patch for life. Offspring have costly, partial long-distance dispersal and compete for breeding sites, which beco

  17. Gender, Education and Population Flows

    DEFF Research Database (Denmark)

    Bennike, Kathrine Bjerg; Faber, Stine Thidemann; Nielsen, Helene Pristed

    During the Danish Presidency for the Nordic Council of Ministers in 2015, attention was drawn towards challenges and best practice examples in relation to gender, education and population flows in peripheral areas throughout the Nordic countries - Norway, Denmark, Sweden, Finland, Iceland...

  18. Energy demand and population change.

    Science.gov (United States)

    Allen, E L; Edmonds, J A

    1981-09-01

    During the post World War 2 years energy consumption has grown 136% while population grew about 51%; per capita consumption of energy expanded, therefore, about 60%. For a given population size, demographic changes mean an increase in energy needs; for instance the larger the group of retirement age people, the smaller their energy needs than are those for a younger group. Estimates indicate that by the year 2000 the energy impact will be toward higher per capita consumption with 60% of the population in the 19-61 age group of workers. Rising female labor force participation will increase the working group even more; it has also been found that income and energy grow at a proportional rate. The authors predict that gasoline consumption within the US will continue to rise with availability considering the larger number of female drivers and higher per capita incomes. The flow of illegal aliens (750,000/year) will have a major impact on income and will use greater amounts of energy than can be expected. A demographic change which will lower energy demands will be the slowdown of the rate of household formation caused by the falling number of young adults. The response of energy demand to price changes is small and slow but incomes play a larger role as does the number of personal automobiles and social changes affecting household formation. Households, commercial space, transportation, and industry are part of every demand analysis and population projections play a major role in determining these factors.

  19. [Nuptiality among Brazil's black population].

    Science.gov (United States)

    Berquo, E

    1987-08-01

    Data from a three percent sample of the 1980 census of Brazil are used to analyze nuptiality trends by ethnic group. The focus is on the homogamy of marriage by color and age and on the marriage patterns of the black population.

  20. Population entropies estimates of proteins

    Science.gov (United States)

    Low, Wai Yee

    2017-05-01

    The Shannon entropy equation provides a way to estimate variability of amino acids sequences in a multiple sequence alignment of proteins. Knowledge of protein variability is useful in many areas such as vaccine design, identification of antibody binding sites, and exploration of protein 3D structural properties. In cases where the population entropies of a protein are of interest but only a small sample size can be obtained, a method based on linear regression and random subsampling can be used to estimate the population entropy. This method is useful for comparisons of entropies where the actual sequence counts differ and thus, correction for alignment size bias is needed. In the current work, an R based package named EntropyCorrect that enables estimation of population entropy is presented and an empirical study on how well this new algorithm performs on simulated dataset of various combinations of population and sample sizes is discussed. The package is available at https://github.com/lloydlow/EntropyCorrect. This article, which was originally published online on 12 May 2017, contained an error in Eq. (1), where the summation sign was missing. The corrected equation appears in the Corrigendum attached to the pdf.

  1. Communication Disorders in Multicultural Populations.

    Science.gov (United States)

    Battle, Dolores E., Ed.

    This text on communication disorders in multicultural populations is intended to provide a framework for speech language pathologists and audiologists in providing services to persons from different cultures and racial backgrounds. The 11 papers are grouped into 2 parts. Papers in part I provide an overview of the major cultural groups in the…

  2. Better Reporting of Population Issues.

    Science.gov (United States)

    Population Education in Asia and the Pacific Newsletter and Forum, 1990

    1990-01-01

    Presented are the focus and the annotated issues from a workshop on new perspectives in population education for 19 Pacific Island journalists, both print and broadcast, from government and nongovernment agencies. The regional workshop was jointly organized by UNESCO and the South Pacific Commission during February 1990, in Auckland, New Zealand.…

  3. Population Growth: Family Planning Programs.

    Science.gov (United States)

    Doberenz, Alexander R., Ed.; Taylor, N. Burwell G., Ed.

    These proceedings of the second annual symposium on population growth bring together speeches and panel discussions on family planning programs. Titles of speeches delivered are: Communicating Family Planning (Mrs. Jean Hutchinson); Effects of New York's Abortion Law Change (Dr. Walter Rogers); The Law and Birth Control, Sterilization and Abortion…

  4. Milky Way populations with TRILEGAL

    Science.gov (United States)

    Girardi, L.

    2016-09-01

    We briefly describe the simulation of stellar populations in the Milky Way by means of the TRIdimensional modeL of thE GALaxy (TRILEGAL) code. Among the many possible uses of this kind of code, we emphasize their role for improving stellar evolution models.

  5. Disability in Singapore's Elderly Population.

    Science.gov (United States)

    Mahesh, Mithila; Abdin, Edimansyah; Vaingankar, Janhavi Ajit; Picco, Louisa; Jeyagurunathan, Anita; Shafie, Saleha Binte; Pang, Shirlene; Sagayadevan, Vathsala; Seow, Esmond; Chong, Siow Ann; Subramaniam, Mythily

    2016-07-01

    Disability increases an individual's dependence and negatively impacts their physical, mental, and social functioning. The current study aims to establish the prevalence and risk factors of disability in Singapore's population. Data was extracted from the Well-being of the Singapore Elderly (WiSE) study. This cross-sectional study recruited participants aged 60 years and above (n = 2421) who were representative of Singapore's multiethnic population. We used the World Health Organization Disability Assessment Schedule (WHODAS) 2.0 to assess the severity of disability in our sample while establishing its associations and correlations with cognitive levels, sociodemographic variables, and chronic illness. Cognitive deficits, old age, female gender, Malay and Indian ethnicity, lack of education, retired or homemaker status, presence of chronic illness (specifically stroke, heart problems, depression, and dementia) were found to be significantly associated with disability in Singapore's elderly population. As hypothesised, participants with deficits in cognition were more likely to indicate higher WHODAS scores. The findings highlighted specific factors associated with disability in this multiethnic population. The identification of these factors would lead the way to the development of appropriate interventions.

  6. Measuring senescence in human populations

    NARCIS (Netherlands)

    Koopman, Jacob Jan Egbert

    2015-01-01

    In this thesis, senescence is measured in human populations according to its definition of an increase in the risks of dysfunction, disease, and death with chronological age. Part I of this thesis investigates how a population’s senescence rate can be measured through the increase in mortality rate

  7. Population and the Colombian economy.

    Science.gov (United States)

    Sanders, T G

    1983-01-01

    Colombia is the only one of the 6 most populous Latin American countries that is currently free of major economic crisis requiring an agreement with the International Monetary Fund. The difference in the economic performances of these countries is relative, since the rate of growth in the Colombian economy was only 1.5% in 1982. Yet, Colombia seems to have weathered the international recession better than most. The crisis atmosphere in the rest of Latin America, triggered by overall economic decline, high rates of inflation, and an indebtedness that soaks up much of export earnings to service it, is lacking in Colombia or present in lesser degree. If Colombia can strengthen its political performance and tighten national unity, it could move through the 1980s with considerable confidence and success in economic development. Colombia differs little from other major Latin American countries with regard to traditionalism and modernization. Most Colombians are secularized. Colombia is far ahead of most comparable Latin American countries in fertility control. The lower rate of population increase defines the extent to which the economy must provide education, health, food, and jobs. 2 other factors are essential for understanding the current situation in Colombia and its prospects for the 1980s. Government policy in the 1970s opted for an austerity program while the other countries were growing rapidly, in large part through borrowed resources. A 2nd factor is the prospect of attaining autonomy in energy production. These special characteristics--population, public policy, and energy--are discussed. Since the mid 1960s Colombia has functioned with 3 family planning programs. Their existence makes contraception easily available to the population generally. In 1960 Colombia had a higher total fertility rate (TFR) 7.0, than either Venezuela (6.6) or Brazil (5.3), but by 1976 its TFR was down to 4.1, while Venezuela's (4.8) and Brazil's (4.3) were now higher. On balance

  8. Population conference: consensus and conflict.

    Science.gov (United States)

    Willson, P D

    1984-01-01

    The United Nations-sponsored International Conference on Population held in Mexico City was both a rejection and an affirmation of a new policy of the Reagan administration. The policy denies international family planning funds to nongovernmental organizations that perform or actively promote abortion as a family planning method in other nations. A compromise statement was accepted urging governments to take appropriate measures to discourage abortion as a family planning method and when possible to provide for the humane treatment and counseling of women ho resorted to abortion. The statement on abortion was 1 of 88 reccomendations approved by the conference. The commitment expressed in the 10-year-old World Population Plan of Action to the rights and responsiblity to all people as reaffirmed. The conference also endorsed family life education and sex education as well as suitable family planning, information and services for adolescents, with due consideration given to the role, rights and obligations of parents. Increased support for international population and family planning programs was urged and World Bank President, Clausen, urged a 4-fold increase in international funding by the year 2000. Most of the conference's recommendations re devoted to the broad range of population policy issues, including morbidity and mortality, international and internal migration, the relationship between population and economic development and the status of women. The purpose of the recommendations is to increase the momentum of international support. The Mexico City conference was characterized by a remarkable degree of consensus about population policies with respect to integration with economic development, the need to respect individual rights and the recognition that all nations have sovereign rights to develop and implement their own population policies. Conflict and controversy arose in the areas of the arms race and the Middle East. The US position on abortion funding

  9. Population information activities in Hungary.

    Science.gov (United States)

    Csahok, I

    1984-12-01

    The focal point for all population information activities in Hungary is the Central Statistical Office which is responsible for the organization and implementation of the decennial population censuses and of the intercensal population surveys and other data collection activities. The Central Statistical Office publishes a large volume of population information. The results of the censuses are presented partly in special census volumes and partly in statistical yearbooks. The Demographic Yearbook and other publications present results of population studies and Hungarian statistics. The Demographic Research Institute, which is part of the Central Statistical Office, is primarily responsible for research activity. The main task of the Institute is to study and analyze population processes and phenomena, as well as explore main demographic trends, carried out by using Hungarian and international demographic data. Demografia and serial publications present results of research activities of the Institute. The Library and Documentation Service, also part of the Central Statistical Office, provides conventional library services. Its main activity is the collection of both Hungarian and foreign and international official statistical publications, as well as theoretical and methodological works. Of a stock of 650,000 volumes covering a wide range of social and economic sciences, in addition to data material, the library has nearly 120,000 official statistical publications consisting mainly of population statistics and demographic data. Another activity of the Library is the processing and dissemination of documentation and it acts as a 2dary source of both Hungarian and foreign publications, especially on demography. The documentation consists of translating articles, book chapters or documents of international organizations, editing annotated bibliographies and disseminating custom-made, user-oriented profiles. This computerized information retrieval system uses Text

  10. The Middle East population puzzle.

    Science.gov (United States)

    Omran, A R; Roudi, F

    1993-07-01

    An overview is provided of Middle Eastern countries on the following topics; population change, epidemiological transition theory and 4 patterns of transition in the middle East, transition in causes of death, infant mortality declines, war mortality, fertility, family planning, age and sex composition, ethnicity, educational status, urbanization, labor force, international labor migration, refugees, Jewish immigration, families, marriage patterns, and future growth. The Middle East is geographically defined as Bahrain, Egypt, Iraq, Jordan, Kuwait, Lebanon, Oman, Qatar, Saudi Arabia, Syria, United Arab Emirates, Yemen, Gaza and the West Bank, Iran, Turkey, and Israel. The Middle East's population grew very little until 1990 when the population was 43 million. Population was about doubled in the mid-1950s at 80 million. Rapid growth occurred after 1950 with declines in mortality due to widespread disease control and sanitation efforts. Countries are grouped in the following ways: persistent high fertility and declining mortality with low to medium socioeconomic conditions (Jordan, Oman, Syria, Yemen, and the West Bank and Gaza), declining fertility and mortality in intermediate socioeconomic development (Egypt, Lebanon, Turkey, and Iran), high fertility and declining mortality in high socioeconomic conditions (Bahrain, Iraq, Kuwait, Qatar, Saudi Arabia, and the United Arab Emirates), and low fertility and mortality in average socioeconomic conditions (Israel). As birth and death rates decline, there is an accompanying shift from communicable diseases to degenerative diseases and increases in life expectancy; this pattern is reflected in the available data from Egypt, Kuwait, and Israel. High infant and child mortality tends to remain a problem throughout the Middle East, with the exception of Israel and the Gulf States. War casualties are undetermined, yet have not impeded the fastest growing population growth rate in the world. The average fertility is 5 births

  11. Rising population and environmental degradation.

    Science.gov (United States)

    Mitra, A

    Environmental degradation is becoming an increasingly ominous threat to the well-being of India's population, and excessive population growth is the primary cause of environmental deterioration. Population growth increases the need to produce consumer products and this need, in turn, intensifies the trend to over-exploit and misuse environmental resources. Efforts to control population growth through contraceptive technology and the expansion of family planning services and to control environmental deterioration via technology and management will meet with little success. A prerequisite for controlling these dual problems is the improvement of living conditions for the masses. Only when individuals acquire a sense of security and have the prospect of acquiring a share in the resources of the country will they be willing to conserve and renew resources and to limit their fertility. Viewed from this prospective, various factors and trends in India can be assessed as either negative or positive. Positive factors, i.e., those which enhance economic oppotunities and security for the general population, include the recent achievement of economic grothw in the country's agricultural and industrial sectors, the growth in technological knowledge, and the expansion of the rural and urban infrastructure. Negative factors include 1) the increase in income inequality, 2) the refusal to grant distributive justice to the masses, 3) the lack of education which impedes public understanding and awareness of environmental issues and promotes under utilization of community and social services, 4) the high unemployment rate which prevents individuals from developing a sense of responsibility and self respect; and 5) the refusal of the government to establish fuel policies to halt the growing problem of deforestation. Major environmental problems include pollution and congestion associated with the geographical concentration of industry; the destruction of the forests which leads to

  12. Developing STR databases on structured populations: the native South Siberian population versus the Russian population.

    Science.gov (United States)

    Zhivotovsky, Lev A; Malyarchuk, Boris A; Derenko, Miroslava V; Wozniak, Marcin; Grzybowski, Tomasz

    2009-09-01

    Developing a forensic DNA database on a population that consists of local ethnic groups separated by physical and cultural barriers is questionable as it can be genetically subdivided. On the other side, small sizes of ethnic groups, especially in alpine regions where they are sub-structured further into small villages, prevent collecting a large sample from each ethnic group. For such situations, we suggest to obtain both a total population database on allele frequencies across ethnic groups and a list of theta-values between the groups and the total data. We have genotyped 558 individuals from the native population of South Siberia, consisting of nine ethnic groups, at 17 autosomal STR loci of the kit packages AmpFlSTR SGM Plus i, Cyrillic AmpFlSTR Profiler Plus. The groups differentiate from each other with average theta-values of around 1.1%, and some reach up to three to four percent at certain loci. There exists between-village differentiation as well. Therefore, a database for the population of South Siberia is composed of data on allele frequencies in the pool of ethnic groups and data on theta-values that indicate variation in allele frequencies across the groups. Comparison to additional data on northeastern Asia (the Chukchi and Koryak) shows that differentiation in allele frequencies among small groups that are separated by large geographic distance can be even greater. In contrast, populations of Russians that live in large cities of the European part of Russia are homogeneous in allele frequencies, despite large geographic distance between them, and thus can be described by a database on allele frequencies alone, without any specific information on theta-values.

  13. Incorporating territory compression into population models

    NARCIS (Netherlands)

    Ridley, J; Komdeur, J; Sutherland, WJ; Sutherland, William J.

    The ideal despotic distribution, whereby the lifetime reproductive success a territory's owner achieves is unaffected by population density, is a mainstay of behaviour-based population models. We show that the population dynamics of an island population of Seychelles warblers (Acrocephalus

  14. 45 CFR 1356.81 - Reporting population.

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false Reporting population. 1356.81 Section 1356.81... § 1356.81 Reporting population. The reporting population is comprised of all youth in the following categories: (a) Served population. Each youth who receives an independent living service paid for or provided...

  15. NIDI scenario. Strong population decline in China

    NARCIS (Netherlands)

    de Beer, J.A.A.

    2016-01-01

    United Nations projections assume that by the end of this century one third of the world population will live in India, China or Nigeria. While population growth in India will slow down and the population size of China will decline, population growth in Nigeria will accelerate. A new NIDI scenario

  16. Statistical thermodynamics of clustered populations.

    Science.gov (United States)

    Matsoukas, Themis

    2014-08-01

    We present a thermodynamic theory for a generic population of M individuals distributed into N groups (clusters). We construct the ensemble of all distributions with fixed M and N, introduce a selection functional that embodies the physics that governs the population, and obtain the distribution that emerges in the scaling limit as the most probable among all distributions consistent with the given physics. We develop the thermodynamics of the ensemble and establish a rigorous mapping to regular thermodynamics. We treat the emergence of a so-called giant component as a formal phase transition and show that the criteria for its emergence are entirely analogous to the equilibrium conditions in molecular systems. We demonstrate the theory by an analytic model and confirm the predictions by Monte Carlo simulation.

  17. Dynamical systems in population biology

    CERN Document Server

    Zhao, Xiao-Qiang

    2017-01-01

    This research monograph provides an introduction to the theory of nonautonomous semiflows with applications to population dynamics. It develops dynamical system approaches to various evolutionary equations such as difference, ordinary, functional, and partial differential equations, and pays more attention to periodic and almost periodic phenomena. The presentation includes persistence theory, monotone dynamics, periodic and almost periodic semiflows, basic reproduction ratios, traveling waves, and global analysis of prototypical population models in ecology and epidemiology. Research mathematicians working with nonlinear dynamics, particularly those interested in applications to biology, will find this book useful. It may also be used as a textbook or as supplementary reading for a graduate special topics course on the theory and applications of dynamical systems. Dr. Xiao-Qiang Zhao is a University Research Professor at Memorial University of Newfoundland, Canada. His main research interests involve applied...

  18. Stochastic problems in population genetics

    CERN Document Server

    Maruyama, Takeo

    1977-01-01

    These are" notes based on courses in Theoretical Population Genetics given at the University of Texas at Houston during the winter quarter, 1974, and at the University of Wisconsin during the fall semester, 1976. These notes explore problems of population genetics and evolution involving stochastic processes. Biological models and various mathematical techniques are discussed. Special emphasis is given to the diffusion method and an attempt is made to emphasize the underlying unity of various problems based on the Kolmogorov backward equation. A particular effort was made to make the subject accessible to biology students who are not familiar with stochastic processes. The references are not exhaustive but were chosen to provide a starting point for the reader interested in pursuing the subject further. Acknowledgement I would like to use this opportunity to express my thanks to Drs. J. F. Crow, M. Nei and W. J. Schull for their hospitality during my stays at their universities. I am indebted to Dr. M. Kimura...

  19. Fish populations surviving estrogen pollution.

    Science.gov (United States)

    Wedekind, Claus

    2014-02-10

    Among the most common pollutants that enter the environment after passing municipal wastewater treatment are estrogens, especially the synthetic 17α-ethinylestradiol that is used in oral contraceptives. Estrogens are potent endocrine disruptors at concentrations frequently observed in surface waters. However, new genetic analyses suggest that some fish populations can be self-sustaining even in heavily polluted waters. We now need to understand the basis of this tolerance.

  20. Food cravings among Brazilian population.

    Science.gov (United States)

    Queiroz de Medeiros, Anna Cecília; Pedrosa, Lucia de Fatima Campos; Yamamoto, Maria Emilia

    2017-01-01

    This study aimed to develop and validate a Brazilian version of the Food Craving Inventory (FCI-Br), adapted to the cultural-gastronomic context of Brazil, and to explore this behavior among adult Brazilians. The Study 1 population consisted of 453 adults from all regions of Brazil. Participants responded to a preliminary form of the instrument online. Exploratory factor analysis revealed an FCI-Br presenting 23 items and three factors: High Fat, Sweet Food and Traditional Meal. The FCI-Br overall reliability was considered adequate (α = 0.82), as were each of the sub-scales. The food items receiving higher average scores from the application of the instrument were chocolate (3.14 ± 1.28; women) and bread (2.94 ± 1.44, men). A significant association was observed between the specific-craving for Sweet Food and female respondents. Most participants reported experiencing more frequent episodes of food craving when alone (68.0%; n = 391) and during the afternoon (32.2%; n = 127) or evening (43.8%; n = 173) hours. Application of the FCI-Br in a population of 649 university students (Study 2) demonstrated a good adjustment of the model developed according to the Confirmatory factor analysis (χ(2)/gl = 2.82, CFI = 0.94; TLI = 0.93; RMSEA = 0.06). The current findings indicate that the FCI-Br has adequate psychometric properties to measure craving behavior with respect to specific food groups in the resident population of Brazil. The results of this study also shed light on the importance of considering the cultural diversity of a population when investigating eating behaviors.

  1. Population Synthesis for Mira Variables

    Institute of Scientific and Technical Information of China (English)

    Chun-Hua Zhu; Chao-Zheng Zha

    2005-01-01

    By means of a population synthesis code, we investigate the Mira variables. Their birth rate (over 0.65yr-1) and their number (~ 130000) in the Galaxy are estimated. For all possible Mira variables, ranges of their initial masses,pulsating periods, mass losses and lifetimes are given. We check our model with the observed Mira variables near the Sun and our results prove to be valid.

  2. For 80 Million Poor Population

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    POVERTY is always a concern of China’s government and people. In 1978, there were 699 impoverished counties in the whole country with a population of about one quarter of a billion, which was concentrated in the middle and western areas of China. These included remote mountainous areas, stone mountain areas, flood plain areas, wilderness areas and regions where minority nationalities live in compact communities. In these areas, resources are scarce, transportation is difficult and limited,

  3. Stellar Populations of Shell Galaxies

    CERN Document Server

    Carlsten, S; Zenteno, A

    2016-01-01

    We present a study of the inner (out to $\\sim$1 R$_{\\mathrm{eff}}$) stellar populations of 9 shell galaxies. We derive stellar population parameters from long slit spectra by both analyzing the Lick indices of the galaxies and by fitting Single Stellar Population model spectra to the full galaxy spectra. The results from the two methods agree reasonably well. Many of the shell galaxies in our sample appear to have lower central $\\mathrm{Mg}_{2}$ index values than non-shell galaxies of the same central velocity dispersion, which is likely due to a past interaction event. Our shell galaxy sample shows a relation between central metallicity and velocity dispersion that is consistent with previous samples of non-shell galaxies. Analyzing the metallicity gradients in our sample, we find an average metallicity gradient of -0.16$\\pm$0.10 dex per decade in radius. We compare this with formation models to constrain the merging history of shell galaxies. We argue that our galaxies likely have undergone major mergers in...

  4. Frustrated fertility: a population paradox.

    Science.gov (United States)

    Mcfalls Ja, J

    1979-05-01

    This Bulletin examines the causes of subfecundity -- the diminished ability to reproduce -- and its effect today and in the past on the fertility, or actual reproductive performance, of individuals and, hence, populations. By definition, all real populations are subfecund since all experience some degree of involuntary biological factors affecting coitus, conception, or the ability to carry a conceptus to live birth which reduces their fecundity below the estimated biological population maximum of 15 children per woman. Affecting both men and women, these factors fall into 5 categories: genetic factors such as blood group incompatibilities and inherited sickle cell anemia or diabetes; psychopathology, including psychic stress and behavioral disorders (e.g., drug and alcohol abuse); infectious diseases such as gonorrhea, malaria, tuberculosis, and postabortion infection; malnutrrition, including the chronic undernutrition of the 3rd World and the overnutrition of developed societies; and hazards posed by increasing amounts of radiation and toxic chemicals in the environment. Reducing subfecundity requires improved living conditions, avoidance of or protection from known hazards, and adoption of medical advances which now can help 40 to 60% of subfecund couples. But even in the U.S. fertility would certainly rise among the 15% of couples now estimated to be involuntarily childless and the 10% who have fewer children than they want, and among disadvantaged groups, and teenagers.

  5. Metallicity dependence of HMXB populations

    CERN Document Server

    Douna, V M; Mirabel, I F; Pedrosa, S E

    2015-01-01

    High-mass X-ray binaries (HMXBs) might have contributed a non-negligible fraction of the energy feedback to the interstellar and intergalactic media at high redshift, becoming important sources for the heating and ionization history of the Universe. However, the importance of this contribution depends on the hypothesized increase in the number of HMXBs formed in low-metallicity galaxies and in their luminosities. In this work we test the aforementioned hypothesis, and quantify the metallicity dependence of HMXB population properties. We compile from the literature a large set of data on the sizes and X-ray luminosities of HMXB populations in nearby galaxies with known metallicities and star formation rates. We use Bayesian inference to fit simple Monte Carlo models that describe the metallicity dependence of the size and luminosity of the HMXB populations. We find that HMXBs are typically ten times more numerous per unit star formation rate in low-metallicity galaxies (12 + log(O/H) < 8, namely < 20% so...

  6. Fish populations in Plynlimon streams

    Directory of Open Access Journals (Sweden)

    D. T. Crisp

    1997-01-01

    Full Text Available In Plynlimon streams, brown trout (Salmo trutta L. are widespread in the upper Wye at population densities of 0.03 to 0.32 fish m-2 and show evidence of successful recruitment in most years. In the upper Severn, brown trout are found only in an area of c. 1670 -2 downstream of Blaenhafren Falls at densities of 0.03 to 0.24 fish -2 and the evidence suggests very variable year to year success in recruitment (Crisp & Beaumont, 1996. Analyses of the data show that temperature differences between afforested and unafforested streams may affect the rates of trout incubation and growth but are not likely to influence species survival. Simple analyses of stream discharge data suggest, but do not prove, that good years for recruitment in the Hafren population were years of low stream discharge. This may be linked to groundwater inputs detected in other studies in this stream. More research is needed to explain the survival of the apparently isolated trout population in the Hafren.

  7. Population policy and family planning.

    Science.gov (United States)

    1977-01-01

    The secret of success of India's population policy is the multipronged approach. Conflicts between public beliefs, customs, and public interests in regard to family size must be resolved through effective educational measures. The state should avoid legal compulsion and rely on volumtary choice by married couples influenced by logical judgment, information, and persuasion. Instead of using coercion, research in specific regions, sub-regions, and local areas should assess feasibility in light of knowledge, attitude, and practice of birth control, and rational goals should be set. Health conditions, particularly of mother and child, are an important approach to fertility and family size. As long as the morbidity of infants is high, the motivation for small family size will be low. Women's education generally should be improved. Later age at marriage also contributed to small family size. Present population policy should be expanded to include a broad-based socioeconomic approach with a social security program. Development through improved agricultural and marketing conditions will distribute the economic benefits for and improve the welfare of the most backward people. Voluntary organizations must be involved in population programs because a wholly state-sponsored program will meet with apathy and disinterest.

  8. Association studies in consanguineous populations

    Energy Technology Data Exchange (ETDEWEB)

    Genin, E.; Clerget-Darpous, F. [Institut National d`Etudes Demographiques, Paris (France)

    1996-04-01

    To study the genetic determinism of multifactorial diseases in large panmictic populations, a strategy consists in looking for an association with markers closely linked to candidate genes. A distribution of marker genotypes different in patients and controls may indicate that the candidate gene is involved in the disease. In panmictic populations, the power to detect the role of a candidate gene depends on the gametic disequilibrium with the marker locus. In consanguineous populations, we show that it depends on the inbreeding coefficient F as well. Inbreeding increases the power to detect the role of a recessive or quasi-recessive disease-susceptibility factor. The gain in power turns out to be greater for small values of the gametic disequilibrium. Moreover, even in the absence of gametic disequilibrium, the presence of inbreeding may allow to detect the role of a recessive factor. Ignoring inbreeding when it exists may lead to reject falsely a recessive model if the mode of inheritance is inferred on the distribution of genotypes among patients. 5 refs., 6 figs., 1 tab.

  9. Population growth and global warming

    Science.gov (United States)

    Short, R.V.

    2009-01-01

    When I was born in 1930, the human population of the world was a mere 2 billion. Today, it has already reached 6.8 billion, and is projected to reach 9.1 billion by 2050. That is unsustainable. It is slowly beginning to dawn on us that Global Warming is the result of increasing human CO2 emissions, and the more people there are in the world, the worse it will become. Ultimately, it is the sky that will prove to be the limit to our numbers. The developed countries of the world are the most affluent, and also the most effluent, so we must lead by example and contain our own population growth and per capita emissions. We also have a big debt to repay to former colonial territories in Africa, Asia and South America, who desperately need our help to contain their excessive rates of population growth. Belgian and Dutch obstetricians and gynaecologists can play a critical role in this endeavour. After all, we already have a pill that will stop global warming – the oral contraceptive pill. PMID:25478068

  10. Subtle sabotage: endocrine disruption in wild populations

    OpenAIRE

    Cheek, Ann Oliver

    2016-01-01

    How important is endocrine disruption as a threat to wildlife populations? This review applies causal criteria to existing studies of wild populations of fish, amphibians, reptiles, birds, and mammals to answer three questions: (1) Have endocrine-mediated effects of contaminant exposure been documented? (2) Have individual adverse effects that could lead to population effects been documented? (3) Have population level effects been documented? In fish, the possibility of population level effec...

  11. A Tale of Two Populations

    Science.gov (United States)

    2005-03-01

    VLT FLAMES Finds Hints of Helium-Richest Stars Ever Seen Summary On the basis of stellar spectra totalling more than 200 hours of effective exposure time with the 8.2-m VLT Kueyen telescope at Paranal (Chile), a team of astronomers [1] has made a surprising discovery about the stars in the giant southern globular cluster Omega Centauri. It has been known for some time that, contrary to other clusters of this type, this stellar cluster harbours two different populations of stars that still burn hydrogen in their centres. One population, accounting for one quarter of its stars, is bluer than the other. Using the FLAMES multi-object spectrograph that is particularly well suited to this kind of work, the astronomers found that the bluer stars contain more heavy elements than those of the redder population. This was exactly opposite to the expectation and they are led to the conclusion that the bluer stars have an overabundance of the light element helium of more than 50%. They are in fact the most helium rich stars ever found. But why is this so? The team suggests that this puzzle may be explained in the following way. First, a great burst of star formation took place during which all the stars of the red population were produced. As other normal stars, these stars transformed their hydrogen into helium by nuclear burning. Some of them, with masses of 10-12 times the mass of the Sun, soon thereafter exploded as supernovae, thereby enriching the interstellar medium in the globular cluster with helium. Next, the blue population stars formed from this helium-rich medium. This unexpected discovery provides important new insights into the way stars may form in larger stellar systems. PR Photo 08a/05: The Omega Centauri Globular Cluster and the Area Surveyed (DSS and ACS/HST) PR Photo 08b/05: The Double Main Sequence of Omega Centauri PR Photo 08c/05: Average Spectra of the Blue and Red Population Stars (FLAMES + VLT) PR Photo 08d/05: The Supernova Scenario Two Populations

  12. Microbial populations in contaminant plumes

    Science.gov (United States)

    Haack, Sheridan K.; Bekins, Barbara A.

    Efficient biodegradation of subsurface contaminants requires two elements: (1) microbial populations with the necessary degradative capabilities, and (2) favorable subsurface geochemical and hydrological conditions. Practical constraints on experimental design and interpretation in both the hydrogeological and microbiological sciences have resulted in limited knowledge of the interaction between hydrogeological and microbiological features of subsurface environments. These practical constraints include: (1) inconsistencies between the scales of investigation in the hydrogeological and microbiological sciences, and (2) practical limitations on the ability to accurately define microbial populations in environmental samples. However, advances in application of small-scale sampling methods and interdisciplinary approaches to site investigations are beginning to significantly improve understanding of hydrogeological and microbiological interactions. Likewise, culture-based and molecular analyses of microbial populations in subsurface contaminant plumes have revealed significant adaptation of microbial populations to plume environmental conditions. Results of recent studies suggest that variability in subsurface geochemical and hydrological conditions significantly influences subsurface microbial-community structure. Combined investigations of site conditions and microbial-community structure provide the knowledge needed to understand interactions between subsurface microbial populations, plume geochemistry, and contaminant biodegradation. La biodégradation efficace des polluants souterrains requiert deux éléments: des populations microbiennes possédant les aptitudes nécessaires à la dégradation, et des conditions géochimiques et hydrologiques souterraines favorables. Des contraintes pratiques sur la conception et l'interprétation des expériences à la fois en microbiologie et en hydrogéologie ont conduit à une connaissance limitée des interactions entre les

  13. ddressing constraints in propagation of Allanblackia spp. through seed sectioning and air layering

    OpenAIRE

    Ofori D A; Asomaning J M; Peprah T; Agyeman V K; Anjarwalla P; Tchoundjeu Z; Mowo J G; Jamnadass R

    2015-01-01

    Allanblackia species are indigenous to West, East and Central African regions with the potential of providing an alternative source of income for rural populations through sale of seed oil. The species therefore needs to be domesticated to support sustainable production of Allanblackia seed oil. Propagation of Allanblackia parviflora through seed germination and air layering was therefore undertaken. Stratified and non-stratified seeds or seed sections were germinated in sand, pla...

  14. Comparative phylogeography of African savannah ungulates

    DEFF Research Database (Denmark)

    Lorenzen, Eline; Heller, Rasmus; Siegismund, Hans Redlef

    2012-01-01

    . Data from across taxa reveal distinct regional lineages, which reflect the survival and divergence of populations in isolated savannah refugia during the climatic oscillations of the Pleistocene. Data from taxa across trophic levels suggest distinct savannah refugia were present in West, East, Southern...... in the high inter- and intraspecific diversity of the region. In contrast, phylogeographic data suggest a stable, long-standing savannah refuge in the south....

  15. Microsatellite data analysis for population genetics.

    Science.gov (United States)

    Kim, Kyung Seok; Sappington, Thomas W

    2013-01-01

    Theories and analytical tools of population genetics have been widely applied for addressing various questions in the fields of ecological genetics, conservation biology, and any context where the role of dispersal or gene flow is important. Underlying much of population genetics is the analysis of variation at selectively neutral marker loci, and microsatellites continue to be a popular choice of marker. In recent decades, software programs to estimate population genetics parameters have been developed at an increasing pace as computational science and theoretical knowledge advance. Numerous population genetics software programs are presently available to analyze microsatellite genotype data, but only a handful are commonly employed for calculating parameters such as genetic variation, genetic structure, patterns of spatial and temporal gene flow, population demography, individual population assignment, and genetic relationships within and between populations. In this chapter, we introduce statistical analyses and relevant population genetic software programs that are commonly employed in the field of population genetics and molecular ecology.

  16. Who fears and who welcomes population decline?

    Directory of Open Access Journals (Sweden)

    Hendrik P. Van Dalen

    2011-08-01

    Full Text Available European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment as well as material welfare losses (tax increases, economic stagnation. In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline.

  17. Population, growth and health expenditure

    Directory of Open Access Journals (Sweden)

    Luis Currais

    2000-12-01

    Full Text Available A genuine understanding of the economic growth process should take into account the extent to which fertility and mortality affect the population growth rate as an endogenous variable. To this end we construct a growth model using an infinite horizon setup in which economic development and health status influence the population growth rate. Mortality depends on health expenditure, and fertility is endogenously determined. Adults within each household take into account the welfare and resources of their current and future descendants. Their decisions determine not only the evolution of the population growth rate but also the evolution of the per capita income.Este artigo analisa a mortalidade e a fertilidade como variáveis endógenas ao modelo e determinantes do crescimento da população associado ao processo de crescimento econômico. Com este propósito, é desenvolvido um modelo de horizonte infinito onde tanto o nível de desenvolvimento econômico quanto o gasto em saúde influenciam a taxa de crescimento da população. Cada família toma suas decisões tendo em conta o bem-estar social e os recursos disponíveis de seus descendentes atuais e futuros. Suas decisões determinam não só a evolução da taxa de crescimento da população, mas também a evolução da renda per capita.

  18. Research methods with disabled populations.

    Science.gov (United States)

    Eckhardt, Elizabeth; Anastas, Jeane

    2006-01-01

    Although social work and related fields need more research involving people with disabilities, such studies can pose special challenges due to lack of understanding of disability issues, the disempowerment and invisibility of many who are disabled, and communication barriers. This article discusses ways of eliminating bias and maintaining ethical safeguards when designing and conducting research on people with disabilities. Participatory action research, which engages those studied in the design and conduct of research, is discussed as a model, as is the use of qualitative methods. Recent methodological innovations in survey research with deaf populations are also described and illustrated.

  19. Population inversion by chirped pulses

    Energy Technology Data Exchange (ETDEWEB)

    Lu Tianshi [Department of Mathematics and Statistics, Wichita State University, Wichita, Kansas 67260-0033 (United States)

    2011-09-15

    In this paper, we analyze the condition for complete population inversion by a chirped pulse over a finite duration. The nonadiabatic transition probability is mapped in the two-dimensional parameter space of coupling strength and detuning amplitude. Asymptotic forms of the probability are derived by the interference of nonadiabatic transitions for sinusoidal and triangular pulses. The qualitative difference between the maps for the two types of pulses is accounted for. The map is used for the design of stable inversion pulses under specific accuracy thresholds.

  20. Measuring happiness in large population

    Science.gov (United States)

    Wenas, Annabelle; Sjahputri, Smita; Takwin, Bagus; Primaldhi, Alfindra; Muhamad, Roby

    2016-01-01

    The ability to know emotional states for large number of people is important, for example, to ensure the effectiveness of public policies. In this study, we propose a measure of happiness that can be used in large scale population that is based on the analysis of Indonesian language lexicons. Here, we incorporate human assessment of Indonesian words, then quantify happiness on large-scale of texts gathered from twitter conversations. We used two psychological constructs to measure happiness: valence and arousal. We found that Indonesian words have tendency towards positive emotions. We also identified several happiness patterns during days of the week, hours of the day, and selected conversation topics.

  1. Blurred edges to population policies.

    Science.gov (United States)

    David, H P

    1992-05-01

    Fertility is now below replacement level in most European countries, especially the industrialized ones. In the last 20 years, several countries have developed or improved pronatalist programs containing incentives that are designed to motivate couples to have a 2nd and especially a 3rd child, to maintain a stable population. The WHO Sexuality and Family Planning Unit called a short consultation on this subject last October. What actually constitutes a pronatalist population program and the connections between public policies and private reproductive behavior were not very clear. Nor is it easy to assess the longer--term demographic effects of pronatalist policies or what influences their effectiveness. The outcome usually reflects the country's history, cultural and religious traditions, changes in lifestyle, and the value given to the family and children. Incentives are defined as monetary or nonmonetary inducements to voluntary reproductive behavior that conforms to specified population policies. They may be small or large, in cash or kind, parity-specific or income-linked, immediate or developed, one-time or incremental, or any combination of these. Disincentives are negative sanctions that are either incurred or thought likely as a result of violating the policy. But both incentives and disincentives are difficult to define. Pronatalist policies designed to encourage early marriage and larger families, thereby raising the future total fertility rate should not be confused with traditional social welfare policies designed simply to ease the burden of childbearing. Some policies have both demographic and social welfare aims. Strong pronatalist policies may be linked with restrictions on contraceptive availability and legal abortion. Moreover, other public policies affecting social security, education, employment, housing, regional planning and the emancipation of women may unintentionally influence demographic behavior. Population policies are the product of

  2. Nonlinear dynamics of interacting populations

    CERN Document Server

    Bazykin, Alexander D

    1998-01-01

    This book contains a systematic study of ecological communities of two or three interacting populations. Starting from the Lotka-Volterra system, various regulating factors are considered, such as rates of birth and death, predation and competition. The different factors can have a stabilizing or a destabilizing effect on the community, and their interplay leads to increasingly complicated behavior. Studying and understanding this path to greater dynamical complexity of ecological systems constitutes the backbone of this book. On the mathematical side, the tool of choice is the qualitative the

  3. New Models for Population Protocols

    CERN Document Server

    Michail, Othon

    2010-01-01

    Wireless sensor networks are about to be part of everyday life. Homes and workplaces capable of self-controlling and adapting air-conditioning for different temperature and humidity levels, sleepless forests ready to detect and react in case of a fire, vehicles able to avoid sudden obstacles or possibly able to self-organize routes to avoid congestion, and so on, will probably be commonplace in the very near future. Mobility plays a central role in such systems and so does passive mobility, that is, mobility of the network stemming from the environment itself. The population protocol model was

  4. Refugees, immigrants aggravate population controls.

    Science.gov (United States)

    Struck, D

    1994-09-07

    The UN Conference on Population and Development in Cairo in 1994 will discuss the pressure of population growth, the increase in the numbers of refugees, and labor migration between developing and developed countries. Population movement has been estimated as 1/50 in the world, regardless of reason. The impact of movement can be to augment a declining work force or to strain resources in poor countries, such as Zaire or Thailand. Rich countries may also respond with resentment and political turmoil, as is currently occurring in Germany. The tendency is to respond after the fact. Rwanda could be used as an example of a country with population pressure on land resources, which has exacerbated ethnic conflict. If the world in 1994 shows this pattern, the concern is that the future prospects are likely to reflect even greater turmoil and migration. The number of refugees has already increased from 2.5 million in 1970 to 20 million today. The head of the UN Commission on Refugees views the end of the Cold War as responsible for exposed and heightened ethnic and tribal rivalry. Migration movement is viewed as the desire for an improvement in quality of life. Significant shifts are to developed countries such as the US, Canada, Australia, and New Zealand. The 1994 UN Plan of Action offers concrete recommendations about mass movements. Recommendations are made to assure host country's assurances of protection in work and safety for migrants, removal of restrictive banking practices that impede monetary transfers between countries, and arrangements for temporary migration. Host countries are urged to provide assistance for return migration. Rights and equal treatment with nationals should be extended to longterm migrants. Each country has a right to enact migration restrictions. Smuggling of immigrants should be stopped through international cooperation. Countries of origin have a responsibility to readmit nationals rejected by other countries. There are few recommendations

  5. Fitting audiology within the population health perspective.

    Science.gov (United States)

    Fitzpatrick, Elizabeth; Johnston, J Cyne Topshee; Angus, Doug; Durieux-Smith, Andrée

    2006-01-01

    The population health perspective has become increasingly apparent in the medical, public health, and policy literature. This article emphasizes the value of applying the population health perspective and associated frameworks to the rehabilitative sciences and particularly to the field of audiology. Key components of the population health perspective--including the determinants of health, the importance of evidence-based practice, and the value of transdisciplinarity--are used to illustrate the relevance of population health to the field of audiology. Using these key concepts from a population health framework and examples from audiology, the adoption of a population health perspective is proposed.

  6. Comment on 'Clay mineralogy of the Pelagic sediments: along a west-east transect in the Indian Ocean by G.S. Roonwal and S.K. Srivastava' Journal of the Geological Society of India 38; 1991; 37-54'

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, V.P.

    stream_size 2 stream_content_type text/plain stream_name J_Geol_Soc_India_38_539.pdf.txt stream_source_info J_Geol_Soc_India_38_539.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  7. Symbolic trephinations and population structure

    Directory of Open Access Journals (Sweden)

    László Szathmáry

    2006-12-01

    Full Text Available The sample examined consists of 19 skulls with symbolic trephinations and 86 skulls without trepanations dated from the X century. Skulls were all excavated in the Great Hungarian Plain in the Carpathian Basin, which was occupied by the Hungarian conquerors at the end of the IX century. The variations of 12 cranial dimensions of the trephined skulls were investigated and compared to the skulls without trepanations after performing a discriminant analysis. The classification results evince that the variability of non-trephined skulls shows a more homogeneous and a more characteristic picture of their own group than the trephined samples, which corresponds to the notion, formed by archaeological evidence and written historical sources, of a both ethnically and socially differing population of the Hungarian conquerors. According to historical research, a part of the population was of Finno-Ugric origin, while the military leading layer of society can be brought into connection with Turkic ethnic groups. All the same, individuals dug up with rich grave furniture and supposed to belong to this upper stratum of society are primarily characterized by the custom of symbolic trephination, and, as our results demonstrate, craniologically they seem to be more heterogeneous.

  8. Direct reciprocity in structured populations.

    Science.gov (United States)

    van Veelen, Matthijs; García, Julián; Rand, David G; Nowak, Martin A

    2012-06-19

    Reciprocity and repeated games have been at the center of attention when studying the evolution of human cooperation. Direct reciprocity is considered to be a powerful mechanism for the evolution of cooperation, and it is generally assumed that it can lead to high levels of cooperation. Here we explore an open-ended, infinite strategy space, where every strategy that can be encoded by a finite state automaton is a possible mutant. Surprisingly, we find that direct reciprocity alone does not lead to high levels of cooperation. Instead we observe perpetual oscillations between cooperation and defection, with defection being substantially more frequent than cooperation. The reason for this is that "indirect invasions" remove equilibrium strategies: every strategy has neutral mutants, which in turn can be invaded by other strategies. However, reciprocity is not the only way to promote cooperation. Another mechanism for the evolution of cooperation, which has received as much attention, is assortment because of population structure. Here we develop a theory that allows us to study the synergistic interaction between direct reciprocity and assortment. This framework is particularly well suited for understanding human interactions, which are typically repeated and occur in relatively fluid but not unstructured populations. We show that if repeated games are combined with only a small amount of assortment, then natural selection favors the behavior typically observed among humans: high levels of cooperation implemented using conditional strategies.

  9. Modelling nova populations in galaxies

    CERN Document Server

    Chen, Hai-Liang; Yungelson, L R; Gilfanov, M; Han, Zhanwen

    2016-01-01

    Theoretical modelling of the evolution of classical and recurrent novae plays an important role in studies of binary evolution, nucleosynthesis and accretion physics. However, from a theoretical perspective the observed statistical properties of novae remain poorly understood. In this paper, we have produced model populations of novae using a hybrid binary population synthesis approach for differing star formation histories (SFHs): a starburst case (elliptical-like galaxies), a constant star formation rate case (spiral-like galaxies) and a composite case (in line with the inferred SFH for M31). We found that the nova rate at 10\\;Gyr in an elliptical-like galaxy is $\\sim 10-20$ times smaller than a spiral-like galaxy with the same mass. The majority of novae in elliptical-like galaxies at the present epoch are characterized by low mass white dwarfs (WDs), long decay times, relatively faint absolute magnitudes and long recurrence periods. In contrast, the majority of novae in spiral-like galaxies at 10\\;Gyr hav...

  10. Reconstructing Native American population history.

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C; Bravi, Claudio M; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria Cátira; Salzano, Francisco M; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, Maria José; Molina, Julio; Carracedo, Angel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B; Alkorta-Aranburu, Gorka; Sukernik, Rem I; Osipova, Ludmila; Fedorova, Sardana A; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean-Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Di Rienzo, Anna; Freimer, Nelson B; Price, Alkes L; Ruiz-Linares, Andrés

    2012-08-16

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved. One contentious issue is whether the settlement occurred by means of a single migration or multiple streams of migration from Siberia. The pattern of dispersals within the Americas is also poorly understood. To address these questions at a higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. Here we show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call 'First American'. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan speakers on both sides of the Panama isthmus, who have ancestry from both North and South America.

  11. Down syndrome in diverse populations.

    Science.gov (United States)

    Kruszka, Paul; Porras, Antonio R; Sobering, Andrew K; Ikolo, Felicia A; La Qua, Samantha; Shotelersuk, Vorasuk; Chung, Brian H Y; Mok, Gary T K; Uwineza, Annette; Mutesa, Leon; Moresco, Angélica; Obregon, María Gabriela; Sokunbi, Ogochukwu Jidechukwu; Kalu, Nnenna; Joseph, Daniel Akinsanya; Ikebudu, Desmond; Ugwu, Christopher Emeka; Okoromah, Christy A N; Addissie, Yonit A; Pardo, Katherine L; Brough, J Joseph; Lee, Ni-Chung; Girisha, Katta M; Patil, Siddaramappa Jagdish; Ng, Ivy S L; Min, Breana Cham Wen; Jamuar, Saumya S; Tibrewal, Shailja; Wallang, Batriti; Ganesh, Suma; Sirisena, Nirmala D; Dissanayake, Vajira H W; Paththinige, C Sampath; Prabodha, L B Lahiru; Richieri-Costa, Antonio; Muthukumarasamy, Premala; Thong, Meow-Keong; Jones, Kelly L; Abdul-Rahman, Omar A; Ekure, Ekanem Nsikak; Adeyemo, Adebowale A; Summar, Marshall; Linguraru, Marius George; Muenke, Maximilian

    2017-01-01

    Down syndrome is the most common cause of cognitive impairment and presents clinically with universally recognizable signs and symptoms. In this study, we focus on exam findings and digital facial analysis technology in individuals with Down syndrome in diverse populations. Photos and clinical information were collected on 65 individuals from 13 countries, 56.9% were male and the average age was 6.6 years (range 1 month to 26 years; SD = 6.6 years). Subjective findings showed that clinical features were different across ethnicities (Africans, Asians, and Latin Americans), including brachycephaly, ear anomalies, clinodactyly, sandal gap, and abundant neck skin, which were all significantly less frequent in Africans (P Down syndrome with a sensitivity of 0.961, specificity of 0.924, and accuracy of 0.943. Only the angles at medial canthus and ala of the nose were common significant findings amongst different ethnicities (Caucasians, Africans, and Asians) when compared to ethnically matched controls. The Asian group had the least number of significant digital facial biometrics at 4, compared to Caucasians at 8 and Africans at 7. In conclusion, this study displays the wide variety of findings across different geographic populations in Down syndrome and demonstrates the accuracy and promise of digital facial analysis technology in the diagnosis of Down syndrome internationally. © 2016 Wiley Periodicals, Inc.

  12. Reconstructing Native American Population History

    Science.gov (United States)

    Reich, David; Patterson, Nick; Campbell, Desmond; Tandon, Arti; Mazieres, Stéphane; Ray, Nicolas; Parra, Maria V.; Rojas, Winston; Duque, Constanza; Mesa, Natalia; García, Luis F.; Triana, Omar; Blair, Silvia; Maestre, Amanda; Dib, Juan C.; Bravi, Claudio M.; Bailliet, Graciela; Corach, Daniel; Hünemeier, Tábita; Bortolini, Maria-Cátira; Salzano, Francisco M.; Petzl-Erler, María Luiza; Acuña-Alonzo, Victor; Aguilar-Salinas, Carlos; Canizales-Quinteros, Samuel; Tusié-Luna, Teresa; Riba, Laura; Rodríguez-Cruz, Maricela; Lopez-Alarcón, Mardia; Coral-Vazquez, Ramón; Canto-Cetina, Thelma; Silva-Zolezzi, Irma; Fernandez-Lopez, Juan Carlos; Contreras, Alejandra V.; Jimenez-Sanchez, Gerardo; Gómez-Vázquez, María José; Molina, Julio; Carracedo, Ángel; Salas, Antonio; Gallo, Carla; Poletti, Giovanni; Witonsky, David B.; Alkorta-Aranburu, Gorka; Sukernik, Rem I.; Osipova, Ludmila; Fedorova, Sardana; Vasquez, René; Villena, Mercedes; Moreau, Claudia; Barrantes, Ramiro; Pauls, David; Excoffier, Laurent; Bedoya, Gabriel; Rothhammer, Francisco; Dugoujon, Jean Michel; Larrouy, Georges; Klitz, William; Labuda, Damian; Kidd, Judith; Kidd, Kenneth; Rienzo, Anna Di; Freimer, Nelson B.; Price, Alkes L.; Ruiz-Linares, Andrés

    2013-01-01

    The peopling of the Americas has been the subject of extensive genetic, archaeological and linguistic research; however, central questions remain unresolved1–5. One contentious issue is whether the settlement occurred via a single6–8 or multiple streams of migration from Siberia9–15. The pattern of dispersals within the Americas is also poorly understood. To address these questions at higher resolution than was previously possible, we assembled data from 52 Native American and 17 Siberian groups genotyped at 364,470 single nucleotide polymorphisms. We show that Native Americans descend from at least three streams of Asian gene flow. Most descend entirely from a single ancestral population that we call “First American”. However, speakers of Eskimo-Aleut languages from the Arctic inherit almost half their ancestry from a second stream of Asian gene flow, and the Na-Dene-speaking Chipewyan from Canada inherit roughly one-tenth of their ancestry from a third stream. We show that the initial peopling followed a southward expansion facilitated by the coast, with sequential population splits and little gene flow after divergence, especially in South America. A major exception is in Chibchan-speakers on both sides of the Panama Isthmus, who have ancestry from both North and South America. PMID:22801491

  13. Population screening in hereditary hemochromatosis.

    Science.gov (United States)

    Motulsky, A G; Beutler, E

    2000-01-01

    Hemochromatosis is a common autosomal recessive condition found in the homozygous state in 1/200-1/400 people of northern-, central-, and western-European origin. It causes increased iron storage, which may lead to liver cirrhosis, liver cancer, heart disease, arthritis, and diabetes in many but not all affected adults, with a higher frequency in males. The condition is easily treated by repeated venesections without side effects but is frequently overlooked. Population screening of adults using iron indices alone or combined with DNA testing has therefore been recommended, but a consensus conference in 1997 recommended that such screening be deferred, owing to uncertainty regarding the extent of clinical disease that may develop in individuals detected by such programs. There was also concern that DNA screening results might be used for discrimination in insurance and occupational settings. Screening family members of patients with evidence of definite iron loading, however, is accepted by all observers. Because serious complications may be overlooked, a more aggressive stance toward case detection in the adult population has been advocated by some observers, realizing that unnecessary treatment might occur. Because additional information regarding the spectrum of clinical disease in homozygotes in now accumulating, a consensus conference in the near future is suggested to consider appropriate policies.

  14. Social exclusion in finite populations

    Science.gov (United States)

    Li, Kun; Cong, Rui; Wu, Te; Wang, Long

    2015-04-01

    Social exclusion, keeping free riders from benefit sharing, plays an important role in sustaining cooperation in our world. Here we propose two different exclusion regimes, namely, peer exclusion and pool exclusion, to investigate the evolution of social exclusion in finite populations. In the peer exclusion regime, each excluder expels all the defectors independently, and thus bears the total cost on his own, while in the pool exclusion regime, excluders spontaneously form an institution to carry out rejection of the free riders, and each excluder shares the cost equally. In a public goods game containing only excluders and defectors, it is found that peer excluders outperform pool excluders if the exclusion costs are small, and the situation is converse once the exclusion costs exceed some critical points, which holds true for all the selection intensities and different update rules. Moreover, excluders can dominate the whole population under a suitable parameters range in the presence of second-order free riders (cooperators), showing that exclusion has prominent advantages over common costly punishment. More importantly, our finding indicates that the group exclusion mechanism helps the cooperative union to survive under unfavorable conditions. Our results may give some insights into better understanding the prevalence of such a strategy in the real world and its significance in sustaining cooperation.

  15. Bioethics, population studies, and geneticophobia.

    Science.gov (United States)

    Salzano, Francisco M

    2015-07-01

    In any research of human populations, the classical principles of bioethics (respect for autonomy, non-maleficence, beneficence, proportionality between risks and benefits, and justice) should be strictly followed. The question of individual and/or community rights should also be considered, as well as some neglected rights, such as the right to benefit from progress in science and technology and the right to know the nature of the group's biological and cultural history; however, in their urge to assure rights, social researchers, bioethics commissions, non-governmental organizations, and community leaders are, in many cases, crossing the limits of good sense. DNA is sometimes interpreted as synonymous to demoniac, and there is a frequent behaviour that I could only describe using a neologism: geneticophobia. There is an irrational attitude against genetic studies aiming to unravel the biological history of a given people and to classify any genome population study as "racist". This behaviour should be opposed; science and the scientific study of humankind are the only way we have to reach the socially adequate objective of the maximum of happiness to the largest number of persons.

  16. Paraguay: population and the economy.

    Science.gov (United States)

    Sanders, T G

    1986-01-01

    Paraguay's political conflicts and development experiences have been accompanied by compensatory population movements; however, economic and population policies of the past are not adequate to address the current economic challenges. The principal structural problem is dependence on international commodity prices. Since late 1984, the international prices for soya and cotton have declined more than 50%; these 2 products account for 83% of official exports. The external debt has grown significantly in the past 5 years and is increasingly difficult to service. A major problem the government faces in servicing the debt and maintaining economic growth is its inability to get control of foreign exchange. Much of Paraguay's external trade is contraband, with the dollars passing into the black market. As a result of the illegal economy, government earnings have been insufficient to cover expenses. Unemployment stands at 12% because of general economic decline, cuts in government expenditure, and the reduction of investment in hydroelectricity. Occupation of new land, the classic solution by the Paraguayan peasantry, is no longer a viable option since all land is now utilized. About 20-25% of Paraguayans live outside the country, expecially in Argentina. In 1986, a commission drafted an Adjustment Plan that recommended a devaluation of the official gurani rate, tax increases, higher tariffs for public services, and incentives to invest in priority areas; however, this plan has not been implemented to date.

  17. Population change and educational development.

    Science.gov (United States)

    Jayasuriya, J E

    1982-06-01

    The 4 principal conditions of a stable society are: 1) minimum disruption of ecological processes, 2) maximum conservation of material and energy or an economy of stock rather than flow, 3) a population in which recruitment equals loss, and 4) a social system in which individuals can enjoy rather than be restricted by the 1st 3 conditions. In 1960 the developing countries set goals relating to education including the achievement of universal primary education, the eradication of illiteracy, and the provision of secondary and tertiary education to meet manpower needs. The countries with the highest enrollment ratios in 1980 were Korea, 100%, Singapore, 100%, Malaysia, 94%, Philippines 80.6%, Thailand, 77.8%, and Iran 75.5%. Eradication of illiteracy has not been reached since by 1990 Afghanistan, India, Nepal, and Pakistan will have illiteracy rates of over 50% and as a result of increases in the absolute number of illiterates over the period of 1970-90 in Afghanistan, Bangladesh, India, Nepal, and Pakistan, the number of illiterates in the developing countries of Asia will increase from 339.1 million in 1970 to 425.6 million in 1990. The females and rural population are especially disadvantaged groups in terms of education; 98.4% of rural females are illiterate as compared to 63.8% of urban males and in Iran 91.7% of rural females compared with 31.3% of urban males are illiterate. One reason for shortfalls in the achievement of educational goals is rapid population growth, especially of school-age groups; for instance the total population aged 6-11 in Indonesia increased by 89.3%. In a study on the Philippines conducted in 1975 it was found that, for the series of high projections, the schedule of age-specific fertility rates observed for 1968-72 resulting in a total fertility rate of 5.89 would remain constant throughout the projection period, the death rate would decline by 4.8 points, international migration would remain negligible; for the low projections

  18. Population and human resources development.

    Science.gov (United States)

    Jones, G W

    1992-06-01

    The concern of this discourse on social development planning was that individuals be part of human resources development. Population growth is an obstacle to social development, but so is national expenditures on the military rather than diverting funds for social improvements. There are important benefits for society in social development: a valued consumption good, increased productivity, and reduced fertility. Dissatisfaction with an economic growth model of development occurred during the 1960s, and by the mid-1980s, human resource development was capsuled in Asia and the Pacific Region in the Jakarta Plan of Action on Human Resources Development and adopted in 1988. Earlier approaches favored the supply side. This article emphasizes "human" development which considers people as more than inputs to productivity. The quality of human resources is dependent on the family and society, the educational system, and individual levels of health and nutrition. Differences in income levels between East and South Asia have been attributed by Oshima to full use of the labor force and mechanization and training of workers. Ogawa, Jones, and Williamson contend that huge investment in infrastructure, efficient absorption of advanced technology, a stable political environment, and commitment to human capital formation are key to development. Demographic transition and decline in fertility at one point reflect growth and engagement in the labor force and resource accumulation. Although East Asia had higher levels of literacy and educational attainment than many developing countries, South Asia still has high fertility. Human resource development is dependent on reduced population growth rates, but rapid population growth is not an insurmountable obstacle to achieving higher levels of education. Rapid population growth is a greater obstacle in poorer countries. The impact can be reflected in increased costs of attaining educational targets of universal primary education or in

  19. PN populations in the local group and distant stellar populations

    Science.gov (United States)

    Reid, Warren

    2016-08-01

    Our understanding of galactic structure and evolution is far from complete. Within the past twelve months we have learnt that the Milky Way is about 50% wider than was previously thought. As a consequence, new models are being developed that force us to reassess the kinematic structure of our Galaxy. Similarly, we need to take a fresh look at the halo structure of external galaxies in our Local Group. Studies of stellar populations, star-forming regions, clusters, the interstellar medium, elemental abundances and late stellar evolution are all required in order to understand how galactic assembly has occurred as we see it. PNe play an important role in this investigation by providing a measure of stellar age, mass, abundances, morphology, kinematics and synthesized matter that is returned to the interstellar medium (ISM). Through a method of chemical tagging, halo PNe can reveal evidence of stellar migration and galactic mergers. This is an outline of the advances that have been made towards uncovering the full number of PNe in our Local Group galaxies and beyond. Current numbers are presented and compared to total population estimates based on galactic mass and luminosity. A near complete census of PNe is crucial to understanding the initial-to-final mass relation for stars with mass >1 to mass of the sun. It also allows us to extract more evolutionary information from luminosity functions and compare dust-to-gas ratios from PNe in different galactic locations. With new data provided by the Gaia satellite, space-based telescopes and the rise of giant and extra-large telescopes, we are on the verge of observing and understanding objects such as PNe in distant galaxies with the same detail we expected from Galactic observations only a decade ago.

  20. Measuring populations to improve vaccination coverage

    Science.gov (United States)

    Bharti, Nita; Djibo, Ali; Tatem, Andrew J.; Grenfell, Bryan T.; Ferrari, Matthew J.

    2016-10-01

    In low-income settings, vaccination campaigns supplement routine immunization but often fail to achieve coverage goals due to uncertainty about target population size and distribution. Accurate, updated estimates of target populations are rare but critical; short-term fluctuations can greatly impact population size and susceptibility. We use satellite imagery to quantify population fluctuations and the coverage achieved by a measles outbreak response vaccination campaign in urban Niger and compare campaign estimates to measurements from a post-campaign survey. Vaccine coverage was overestimated because the campaign underestimated resident numbers and seasonal migration further increased the target population. We combine satellite-derived measurements of fluctuations in population distribution with high-resolution measles case reports to develop a dynamic model that illustrates the potential improvement in vaccination campaign coverage if planners account for predictable population fluctuations. Satellite imagery can improve retrospective estimates of vaccination campaign impact and future campaign planning by synchronizing interventions with predictable population fluxes.