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Sample records for admixture mapping studies

  1. The Admixture Structure and Genetic Variation of the Archipelago of Cape Verde and Its Implications for Admixture Mapping Studies

    PubMed Central

    Beleza, Sandra; Campos, Joana; Lopes, Jailson; Araújo, Isabel Inês; Hoppfer Almada, Ana; e Silva, António Correia; Parra, Esteban J.; Rocha, Jorge

    2012-01-01

    Recently admixed populations offer unique opportunities for studying human history and for elucidating the genetic basis of complex traits that differ in prevalence between human populations. Historical records, classical protein markers, and preliminary genetic data indicate that the Cape Verde islands in West Africa are highly admixed and primarily descended from European males and African females. However, little is known about the variation in admixture levels, admixture dynamics and genetic diversity across the islands, or about the potential of Cape Verde for admixture mapping studies. We have performed a detailed analysis of phenotypic and genetic variation in Cape Verde based on objective skin color measurements, socio-economic status (SES) evaluations and data for 50 autosomal, 34 X-chromosome, and 21 non-recombinant Y-chromosome (NRY) markers in 845 individuals from six islands of the archipelago. We find extensive genetic admixture between European and African ancestral populations (mean West African ancestry = 0.57, sd = 0.08), with individual African ancestry proportions varying considerably among the islands. African ancestry proportions calculated with X and Y-chromosome markers confirm that the pattern of admixture has been sex-biased. The high-resolution NRY-STRs reveal additional patterns of variation among the islands that are most consistent with differentiation after admixture. The differences in the autosomal admixture proportions are clearly evident in the skin color distribution across the islands (Pearson r = 0.54, P-value<2e–16). Despite this strong correlation, there are significant interactions between SES and skin color that are independent of the relationship between skin color and genetic ancestry. The observed distributions of admixture, genetic variation and skin color and the relationship of skin color with SES relate to historical and social events taking place during the settlement history of Cape Verde, and have

  2. GWAS and admixture mapping identify different asthma-associated loci in Latinos: The GALA II Study

    PubMed Central

    Galanter, Joshua M; Gignoux, Christopher R; Torgerson, Dara G; Roth, Lindsey A; Eng, Celeste; Oh, Sam S; Nguyen, Elizabeth A; Drake, Katherine A; Huntsman, Scott; Hu, Donglei; Sen, Saunak; Davis, Adam; Farber, Harold J.; Avila, Pedro C.; Brigino-Buenaventura, Emerita; LeNoir, Michael A.; Meade, Kelley; Serebrisky, Denise; Borrell, Luisa N; Rodríguez-Cintrón, William; Estrada, Andres Moreno; Mendoza, Karla Sandoval; Winkler, Cheryl A.; Klitz, William; Romieu, Isabelle; London, Stephanie J.; Gilliland, Frank; Martinez, Fernando; Bustamante, Carlos; Williams, L Keoki; Kumar, Rajesh; Rodríguez-Santana, José R.; Burchard, and Esteban G.

    2013-01-01

    Background Asthma is a complex disease with both genetic and environmental causes. Genome-wide association studies of asthma have mostly involved European populations and replication of positive associations has been inconsistent. Objective To identify asthma-associated genes in a large Latino population with genome-wide association analysis and admixture mapping. Methods Latino children with asthma (n = 1,893) and healthy controls (n = 1,881) were recruited from five sites in the United States: Puerto Rico, New York, Chicago, Houston, and the San Francisco Bay Area. Subjects were genotyped on an Affymetrix World Array IV chip. We performed genome-wide association and admixture mapping to identify asthma-associated loci. Results We identified a significant association between ancestry and asthma at 6p21 (lowest p-value: rs2523924, p < 5 × 10−6). This association replicates in a meta-analysis of the EVE Asthma Consortium (p = 0.01). Fine mapping of the region in this study and the EVE Asthma Consortium suggests an association between PSORS1C1 and asthma. We confirmed the strong allelic association between the 17q21 asthma in Latinos (IKZF3, lowest p-value: rs90792, OR: 0.67, 95% CI 0.61 – 0.75, p = 6 × 10−13) and replicated associations in several genes that had previously been associated with asthma in genome-wide association studies. Conclusions Admixture mapping and genome-wide association are complementary techniques that provide evidence for multiple asthma-associated loci in Latinos. Admixture mapping identifies a novel locus on 6p21 that replicates in a meta-analysis of several Latino populations, while genome-wide association confirms the previously identified locus on 17q21. PMID:24406073

  3. Results from a Prostate Cancer Admixture Mapping Study in African American Men

    PubMed Central

    Bock, Cathryn H.; Schwartz, Ann G.; Ruterbusch, Julie J.; Levin, Albert M.; Neslund-Dudas, Christine; Land, Susan J.; Wenzlaff, Angela S.; Reich, David; McKeigue, Paul; Chen, Wei; Heath, Elisabeth I.; Powell, Isaac J.; Kittles, Rick A.; Rybicki, Benjamin A.

    2010-01-01

    There are considerable racial disparities in prostate cancer risk, with a 60% higher incidence rate among African American (AA) men compared with European American (EA) men, and a 2.4 fold higher mortality rate in AA men than in EA men. Recently, studies have implicated several African-ancestry associated prostate cancer susceptibility loci on chromosome 8q24. In the current study, we performed admixture mapping in AA men from two independent case-control studies of prostate cancer to confirm the 8q24 ancestry association and also identify other genomic regions that may harbor prostate cancer susceptibility genes. A total of 482 cases and 261 controls were genotyped for 1,509 ancestry informative markers across the genome. The mean estimated individual admixture proportions were 20% European and 80% African. The most significant observed increase in European ancestry occurred at rs2141360 on chromosome 7q31 in both the case-only (p=0.0000035) and case-control analyses. The most significant observed increase in African ancestry across the genome occurred at a locus on chromosome 5q35 identified by SNPs rs7729084 (case-only analysis: p=0.002), and rs12474977 (case-control analysis: p=0.004), which are separated by 646 kb and were adjacent to one another on the panel. On chromosome 8, rs4367565 was associated with the greatest excess African ancestry in both the case-only and case-control analyses (case-only and case-control p=0.02), confirming previously reported African-ancestry associations with chromosome 8q24. In conclusion, we confirmed ancestry associations on 8q24, and identified additional ancestry-associated regions potentially harboring prostate cancer susceptibility loci. PMID:19568772

  4. Admixture mapping of serum vitamin D and parathyroid hormone concentrations in the African American-Diabetes Heart Study.

    PubMed

    Palmer, Nicholette D; Divers, Jasmin; Lu, Lingyi; Register, Thomas C; Carr, J Jeffrey; Hicks, Pamela J; Smith, S Carrie; Xu, Jianzhao; Judd, Suzanne E; Irvin, Marguerite R; Gutierrez, Orlando M; Bowden, Donald W; Wagenknecht, Lynne E; Langefeld, Carl D; Freedman, Barry I

    2016-06-01

    Vitamin D and intact parathyroid hormone (iPTH) concentrations differ between individuals of African and European descent and may play a role in observed racial differences in bone mineral density (BMD). These findings suggest that mapping by admixture linkage disequilibrium (MALD) may be informative for identifying genetic variants contributing to these ethnic disparities. Admixture mapping was performed for serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, vitamin D-binding protein (VDBP), bioavailable vitamin D, and iPTH concentrations and computed tomography measured thoracic and lumbar vertebral volumetric BMD in 552 unrelated African Americans with type 2 diabetes from the African American-Diabetes Heart Study. Genotyping was performed using a custom Illumina ancestry informative marker (AIM) panel. For each AIM, the probability of inheriting 0, 1, or 2 copies of a European-derived allele was determined. Non-parametric linkage analysis was performed by testing for association between each AIM using these probabilities among phenotypes, accounting for global ancestry, age, and gender. Fine-mapping of MALD peaks was facilitated by genome-wide association study (GWAS) data. VDBP levels were significantly linked in proximity to the protein coding locus (rs7689609, LOD=11.05). Two loci exhibited significant linkage signals for 1,25-dihydroxyvitamin D on 13q21.2 (rs1622710, LOD=3.20) and 12q13.2 (rs11171526, LOD=3.10). iPTH was significantly linked on 9q31.3 (rs7854368, LOD=3.14). Fine-mapping with GWAS data revealed significant known (rs7041 with VDBP, P=1.38×10(-82)) and novel (rs12741813 and rs10863774 with VDBP, P<6.43×10(-5)) loci with plausible biological roles. Admixture mapping in combination with fine-mapping has focused efforts to identify loci contributing to ethnic differences in vitamin D-related traits. PMID:27032714

  5. Skin pigmentation, biogeographical ancestry and admixture mapping.

    PubMed

    Shriver, Mark D; Parra, Esteban J; Dios, Sonia; Bonilla, Carolina; Norton, Heather; Jovel, Celina; Pfaff, Carrie; Jones, Cecily; Massac, Aisha; Cameron, Neil; Baron, Archie; Jackson, Tabitha; Argyropoulos, George; Jin, Li; Hoggart, Clive J; McKeigue, Paul M; Kittles, Rick A

    2003-04-01

    Ancestry informative markers (AIMs) are genetic loci showing alleles with large frequency differences between populations. AIMs can be used to estimate biogeographical ancestry at the level of the population, subgroup (e.g. cases and controls) and individual. Ancestry estimates at both the subgroup and individual level can be directly instructive regarding the genetics of the phenotypes that differ qualitatively or in frequency between populations. These estimates can provide a compelling foundation for the use of admixture mapping (AM) methods to identify the genes underlying these traits. We present details of a panel of 34 AIMs and demonstrate how such studies can proceed, by using skin pigmentation as a model phenotype. We have genotyped these markers in two population samples with primarily African ancestry, viz. African Americans from Washington D.C. and an African Caribbean sample from Britain, and in a sample of European Americans from Pennsylvania. In the two African population samples, we observed significant correlations between estimates of individual ancestry and skin pigmentation as measured by reflectometry (R(2)=0.21, P<0.0001 for the African-American sample and R(2)=0.16, P<0.0001 for the British African-Caribbean sample). These correlations confirm the validity of the ancestry estimates and also indicate the high level of population structure related to admixture, a level that characterizes these populations and that is detectable by using other tests to identify genetic structure. We have also applied two methods of admixture mapping to test for the effects of three candidate genes (TYR, OCA2, MC1R) on pigmentation. We show that TYR and OCA2 have measurable effects on skin pigmentation differences between the west African and west European parental populations. This work indicates that it is possible to estimate the individual ancestry of a person based on DNA analysis with a reasonable number of well-defined genetic markers. The implications and

  6. A Genomewide Admixture Map for Latino Populations

    PubMed Central

    Price, Alkes L. ; Patterson, Nick ; Yu, Fuli ; Cox, David R. ; Waliszewska, Alicja ; McDonald, Gavin J. ; Tandon, Arti ; Schirmer, Christine ; Neubauer, Julie ; Bedoya, Gabriel ; Duque, Constanza ; Villegas, Alberto ; Bortolini, Maria Catira ; Salzano, Francisco M. ; Gallo, Carla ; Mazzotti, Guido ; Tello-Ruiz, Marcela ; Riba, Laura ; Aguilar-Salinas, Carlos A. ; Canizales-Quinteros, Samuel ; Menjivar, Marta ; Klitz, William ; Henderson, Brian ; Haiman, Christopher A. ; Winkler, Cheryl ; Tusie-Luna, Teresa ; Ruiz-Linares, Andrés ; Reich, David 

    2007-01-01

    Admixture mapping is an economical and powerful approach for localizing disease genes in populations of recently mixed ancestry and has proven successful in African Americans. The method holds equal promise for Latinos, who typically inherit a mix of European, Native American, and African ancestry. However, admixture mapping in Latinos has not been practical because of the lack of a map of ancestry-informative markers validated in Native American and other populations. To address this, we screened multiple databases, containing millions of markers, to identify 4,186 markers that were putatively informative for determining the ancestry of chromosomal segments in Latino populations. We experimentally validated each of these markers in at least 232 new Latino, European, Native American, and African samples, and we selected a subset of 1,649 markers to form an admixture map. An advantage of our strategy is that we focused our map on markers distinguishing Native American from other ancestries and restricted it to markers with very similar frequencies in Europeans and Africans, which decreased the number of markers needed and minimized the possibility of false disease associations. We evaluated the effectiveness of our map for localizing disease genes in four Latino populations from both North and South America. PMID:17503322

  7. Genome-wide Association Study and Admixture Mapping Reveal New Loci Associated with Total IgE Levels in Latinos

    PubMed Central

    Pino-Yanes, Maria; Gignoux, Christopher R.; Galanter, Joshua M.; Levin, Albert M.; Campbell, Catarina D.; Eng, Celeste; Huntsman, Scott; Nishimura, Katherine K.; Gourraud, Pierre-Antoine; Mohajeri, Kiana; O'Roak, Brian J.; Hu, Donglei; Mathias, Rasika A.; Nguyen, Elizabeth A.; Roth, Lindsey A.; Padhukasahasram, Badri; Moreno-Estrada, Andres; Sandoval, Karla; Winkler, Cheryl A.; Lurmann, Fred; Davis, Adam; Farber, Harold J.; Meade, Kelley; Avila, Pedro C.; Serebrisky, Denise; Chapela, Rocio; Ford, Jean G.; Lenoir, Michael A.; Thyne, Shannon M.; Brigino-Buenaventura, Emerita; Borrell, Luisa N.; Rodriguez-Cintron, William; Sen, Saunak; Kumar, Rajesh; Rodriguez-Santana, Jose R.; Bustamante, Carlos D.; Martinez, Fernando D.; Raby, Benjamin A.; Weiss, Scott T.; Nicolae, Dan L.; Ober, Carole; Meyers, Deborah A.; Bleecker, Eugene R.; Mack, Steven J.; Hernandez, Ryan D.; Eichler, Evan E.; Barnes, Kathleen C.; Williams, L. Keoki; Torgerson, Dara G.; Burchard, Esteban G.

    2014-01-01

    Background Immunoglobulin E (IgE) is a key mediator of allergic inflammation and is frequently elevated in allergic disorders. Objective To identify genetic variants associated with IgE levels in Latinos. Methods We performed a genome-wide association study (GWAS) and admixture mapping of total IgE levels in 3,334 Latinos from the Genes-environments & Admixture in Latino Americans (GALA II) study. Replication was evaluated in 454 Latinos, 1,564 European Americans, and 3,187 African Americans from independent studies. Results We confirmed associations of six genes identified by previous GWAS and identified a novel genome-wide significant association of a polymorphism in ZNF365 with total IgE (rs200076616, p=2.3x10−8). We next identified four admixture mapping peaks (6p21.32-p22.1, 13p22-31, 14q23.2, and 22q13.1) where local African, European, and/or Native American ancestry was significantly associated with IgE levels. The most significant peak was 6p21.32-p22.1, where Native American ancestry was associated with lower levels of IgE (p=4.95x10−8). All but 22q13.1 were replicated in an independent sample of Latinos, and two of the peaks were replicated in African Americans (6p21.32-p22.1 and 14q23.2). Fine mapping of 6p21.32-p22.1 identified six genome-wide significant single nucleotide polymorphisms in Latinos, two of which replicated in European Americans. Another SNP was peak-wide significant within 14q23.2 in African Americans (rs1741099, p=3.7x10−6), and replicated in non-African American samples (p=0.011). Conclusion We confirmed genetic associations at six genes, and identified novel associations within ZNF365, HLA-DQA1, and 14q23.2. Our results highlight the importance of studying diverse, multi-ethnic populations to uncover novel loci associated with total IgE levels. PMID:25488688

  8. Follow-up to genome-wide linkage and admixture mapping studies implicates components of the extracellular matrix in susceptibility to and size of uterine fibroids

    PubMed Central

    Aissani, Brahim; Zhang, Kui; Wiener, Howard

    2014-01-01

    Objective To conduct a follow-up association mapping to independent genome-wide linkage and admixture mapping studies of uterine leiomyoma. Design Case-control study. Setting Cross sectional study. Patients A total of 1,045 premenopausal North American women participants to the NIEHS uterine fibroid study. Intervention(s) None. Main Outcome Measure(s) We genotyped 2,772 single nucleotide polymorphisms from candidate genes located in peaks from linkage mapping (2q37, 3p21, 5p13, 10p11, 11p15, 12q14, 17q25) or admixture linkage disequilibrium mapping (2q37, 4p16.1, 10q26) and reported to have regulated expression in uterine fibroids. Results We report significant associations of variant members of the collagen gene family with the risk and tumor size, including missense variants in COL6A3 and COL13A, with replications in the African and European American study groups. Furthermore, the cell-matrix Rho GTPase-encoding ARHGAP26 gene and MAN1C1, a gene encoding a Golgi mannosidase involved in the maturation of procollagens emerged as new candidate UL genes affecting both the risk and tumor size. Conclusion Our data converge onto a model of UL pathogenesis possibly resulting from altered regulation, maintenance and/or renewal of the extracellular matrix. PMID:25455875

  9. A Genome-wide Analysis of Admixture in Uyghurs and a High-Density Admixture Map for Disease-Gene Discovery

    PubMed Central

    Xu, Shuhua; Jin, Li

    2008-01-01

    Following up on our previous study, we conducted a genome-wide analysis of admixture for two Uyghur population samples (HGDP-UG and PanAsia-UG), collected from the northern and southern regions of Xinjiang in China, respectively. Both HGDP-UG and PanAsia-UG showed a substantial admixture of East-Asian (EAS) and European (EUR) ancestries, with an empirical estimation of ancestry contribution of 53:47 (EAS:EUR) and 48:52 for HGDP-UG and PanAsia-UG, respectively. The effective admixture time under a model with a single pulse of admixture was estimated as 110 generations and 129 generations, or admixture events occurred about 2200 and 2580 years ago for HGDP-UG and PanAsia-UG, respectively, assuming an average of 20 yr per generation. Despite Uyghurs' earlier history compared to other admixture populations, admixture mapping, holds promise for this population, because of its large size and its mixture of ancestry from different continents. We screened multiple databases and identified a genome-wide single-nucleotide polymorphism panel that can distinguish EAS and EUR ancestry of chromosomal segments in Uyghurs. The panel contains 8150 ancestry-informative markers (AIMs) showing large frequency differences between EAS and EUR populations (FST > 0.25, mean FST = 0.43) but small frequency differences (7999 AIMs validated) within both populations (FST < 0.05, mean FST < 0.01). We evaluated the effectiveness of this admixture map for localizing disease genes in two Uyghur populations. To our knowledge, our map constitutes the first practical resource for admixture mapping in Uyghurs, and it will enable studies of diseases showing differences in genetic risk between EUR and EAS populations. PMID:18760393

  10. Genome-Wide Linkage and Admixture Mapping of Type 2 Diabetes in African American Families From the American Diabetes Association GENNID (Genetics of NIDDM) Study Cohort

    PubMed Central

    Elbein, Steven C.; Das, Swapan K.; Hallman, D. Michael; Hanis, Craig L.; Hasstedt, Sandra J.

    2009-01-01

    OBJECTIVE—We used a single nucleotide polymorphism (SNP) map in a large cohort of 580 African American families to identify regions linked to type 2 diabetes, age of type 2 diabetes diagnosis, and BMI. RESEARCH DESIGN AND METHODS—After removing outliers and problematic samples, we conducted linkage analysis using 5,914 SNPs in 1,344 individuals from 530 families. Linkage analysis was conducted using variance components for type 2 diabetes, age of type 2 diabetes diagnosis, and BMI and nonparametric linkage analyses. Ordered subset analyses were conducted ranking on age of type 2 diabetes diagnosis, BMI, waist circumference, waist-to-hip ratio, and amount of European admixture. Admixture mapping was conducted using 4,486 markers not in linkage disequilibrium. RESULTS—The strongest signal for type 2 diabetes (logarithm of odds [LOD] 4.53) was a broad peak on chromosome 2, with weaker linkage to age of type 2 diabetes diagnosis (LOD 1.82). Type 2 diabetes and age of type 2 diabetes diagnosis were linked to chromosome 13p (3–22 cM; LOD 2.42 and 2.46, respectively). Age of type 2 diabetes diagnosis was linked to 18p (66 cM; LOD 2.96). We replicated previous reports on chromosome 7p (79 cM; LOD 2.93). Ordered subset analysis did not overlap with linkage of unselected families. The best admixture score was on chromosome 12 (90 cM; P = 0.0003). CONCLUSIONS—The linkage regions on chromosomes 7 (27–78 cM) and 18p overlap prior reports, whereas regions on 2p and 13p linkage are novel. Among potential candidate genes implicated are TCF7L1, VAMP5, VAMP8, CDK8, INSIG2, IPF1, PAX8, IL18R1, members of the IL1 and IL1 receptor families, and MAP4K4. These studies provide a complementary approach to genome-wide association scans to identify causative genes for African American diabetes. PMID:18840782

  11. Admixture mapping of lung cancer in 1812 African-Americans

    PubMed Central

    Schwartz, Ann G.; Wenzlaff, Angela S.; Bock, Cathryn H.; Ruterbusch, Julie J.; Chen, Wei; Cote, Michele L.; Artis, Amanda S.; Van Dyke, Alison L.; Land, Susan J.; Harris, Curtis C.; Pine, Sharon R.; Spitz, Margaret R.; Amos, Christopher I.; Levin, Albert M.; McKeigue, Paul M.

    2011-01-01

    Lung cancer continues to be the leading cause of cancer death in the USA and the best example of a cancer with undisputed evidence of environmental risk. However, a genetic contribution to lung cancer has also been demonstrated by studies of familial aggregation, family-based linkage, candidate gene studies and most recently genome-wide association studies (GWAS). The African-American population has been underrepresented in these genetic studies and has patterns of cigarette use and linkage disequilibrium that differ from patterns in other populations. Therefore, studies in African-Americans can provide complementary data to localize lung cancer susceptibility genes and explore smoking dependence-related genes. We used admixture mapping to further characterize genetic risk of lung cancer in a series of 837 African-American lung cancer cases and 975 African-American controls genotyped at 1344 ancestry informative single-nucleotide polymorphisms. Both case-only and case–control analyses were conducted using ADMIXMAP adjusted for age, sex, pack-years of smoking, family history of lung cancer, history of emphysema and study site. In case-only analyses, excess European ancestry was observed over a wide region on chromosome 1 with the largest excess seen at rs6587361 for non-small-cell lung cancer (NSCLC) (Z-score = −4.33; P = 1.5 × 10−5) and for women with NSCLC (Z-score = −4.82; P = 1.4 × 10−6). Excess African ancestry was also observed on chromosome 3q with a peak Z-score of 3.33 (P = 0.0009) at rs181696 among ever smokers with NSCLC. These results add to the findings from the GWAS in Caucasian populations and suggest novel regions of interest. PMID:21115650

  12. Detecting adaptive trait loci in nonmodel systems: divergence or admixture mapping?

    PubMed

    Crawford, Jacob E; Nielsen, Rasmus

    2013-12-01

    Mapping adaptive trait loci (ATL) underlying ecological divergence is an essential step towards understanding the processes that generate phenotypic diversity. Technological advances have made it possible to sequence exomes in nonmodel systems, providing an efficient means of analysing functional genetic variants. Divergence scans of genetic markers for outlier loci, or 'divergence mapping', have been used to map locally adapted genes, but this approach is likely to be underpowered when background divergence is elevated. Genotype-phenotype association tests in admixed populations, or 'admixture mapping', may provide a useful approach for mapping locally adapted loci when neutral divergence is high. To determine the power and limits of divergence mapping, we simulated exomes containing a single ATL across two parental populations of varying neutral divergence, estimated divergence and quantified the power to identify the ATL. We found that divergence mapping had very high power when background FST is <0.2, but decreased dramatically above this level. To evaluate the utility of admixture mapping, we simulated exomes from admixed populations, then simulated phenotypes, conducted genotype-phenotype association tests and found that even two generations of random mating after admixture could provide high mapping power in scenarios where pure divergence mapping was ineffective (FST = 0.35). Moreover, admixture mapping had high power across all levels of divergence after 20 generations since admixture. Together with high-throughput exome sequencing, admixture mapping could be used to map ATL in systems such as Heliconius butterflies or Gryllus crickets when experimental design and analytical approach are chosen accordingly. PMID:24128338

  13. African Ancestry Analysis and Admixture Genetic Mapping for Proliferative Diabetic Retinopathy in African Americans

    PubMed Central

    Tandon, Arti; Chen, Ching J.; Penman, Alan; Hancock, Heather; James, Maurice; Husain, Deeba; Andreoli, Christopher; Li, Xiaohui; Kuo, Jane Z.; Idowu, Omolola; Riche, Daniel; Papavasilieou, Evangelia; Brauner, Stacey; Smith, Sataria O.; Hoadley, Suzanne; Richardson, Cole; Kieser, Troy; Vazquez, Vanessa; Chi, Cheryl; Fernandez, Marlene; Harden, Maegan; Cotch, Mary Frances; Siscovick, David; Taylor, Herman A.; Wilson, James G.; Reich, David; Wong, Tien Y.; Klein, Ronald; Klein, Barbara E. K.; Rotter, Jerome I.; Patterson, Nick; Sobrin, Lucia

    2015-01-01

    Purpose. To examine the relationship between proportion of African ancestry (PAA) and proliferative diabetic retinopathy (PDR) and to identify genetic loci associated with PDR using admixture mapping in African Americans with type 2 diabetes (T2D). Methods. Between 1993 and 2013, 1440 participants enrolled in four different studies had fundus photographs graded using the Early Treatment Diabetic Retinopathy Study scale. Cases (n = 305) had PDR while controls (n = 1135) had nonproliferative diabetic retinopathy (DR) or no DR. Covariates included diabetes duration, hemoglobin A1C, systolic blood pressure, income, and education. Genotyping was performed on the Affymetrix platform. The association between PAA and PDR was evaluated using logistic regression. Genome-wide admixture scanning was performed using ANCESTRYMAP software. Results. In the univariate analysis, PDR was associated with increased PAA (odds ratio [OR] = 1.36, 95% confidence interval [CI] = 1.16–1.59, P = 0.0002). In multivariate regression adjusting for traditional DR risk factors, income and education, the association between PAA and PDR was attenuated and no longer significant (OR = 1.21, 95% CI = 0.59–2.47, P = 0.61). For the admixture analyses, the maximum genome-wide score was 1.44 on chromosome 1. Conclusions. In this largest study of PDR in African Americans with T2D to date, an association between PAA and PDR is not present after adjustment for clinical, demographic, and socioeconomic factors. No genome-wide significant locus (defined as having a locus-genome statistic > 5) was identified with admixture analysis. Further analyses with even larger sample sizes are needed to definitively assess if any admixture signal for DR is present. PMID:26098467

  14. Markers for Mapping by Admixture Linkage Disequilibrium in African American and Hispanic Populations

    PubMed Central

    Smith, Michael W.; Lautenberger, James A.; Shin, Hyoung Doo; Chretien, Jean-Paul; Shrestha, Sadeep; Gilbert, Dennis A.; O’Brien, Stephen J.

    2001-01-01

    Population linkage disequilibrium occurs as a consequence of mutation, selection, genetic drift, and population substructure produced by admixture of genetically distinct ethnic populations. African American and Hispanic ethnic groups have a history of significant gene flow among parent groups, which can be of value in affecting genome scans for disease-gene discovery in the case-control and transmission/disequilibrium test designs. Disease-gene discovery using mapping by admixture linkage disequilibrium (MALD) requires a map of polymorphic markers that differentiate between the founding populations, along with differences in disease-gene allele frequencies. We describe markers appropriate for MALD mapping by assessing allele frequencies of 744 short tandem repeats (STRs) in African Americans, Hispanics, European Americans, and Asians, by choosing STR markers that have large differences in composite δ, log-likelihood ratios, and/or I*(2) for MALD. Additional markers can be added to this MALD map by utilization of the rapidly growing single-nucleotide–polymorphism databases and the literature, to achieve a 3–10-cM scanning scale. The map will be useful for studies of diseases, including prostate and breast cancer, diabetes, hypertension, and end-stage renal disease, that have large differences in incidence between the founding populations of either Hispanics or African Americans. PMID:11590548

  15. Admixture Mapping Provides Evidence of Association of the VNN1 Gene with Hypertension

    PubMed Central

    Zhu, Xiaofeng; Cooper, Richard S.

    2007-01-01

    Migration patterns in modern societies have created the opportunity to use population admixture as a strategy to identify susceptibility genes. To implement this strategy, we genotyped a highly informative ancestry marker panel of 2270 single nucleotide polymorphisms in a random population sample of African Americans (N = 1743), European Americans (N = 1000) and Mexican Americans (N = 581). We then examined the evidence for over-transmission of specific loci to cases from one of the two ancestral populations. Hypertension cases and controls were defined based on standard clinical criteria. Both case-only and case-control analyses were performed among African Americans. With the genome-wide markers we replicated the findings identified in our previous admixture mapping study on chromosomes 6 and 21 [1]. For case-control analysis we then genotyped 51 missense SNPs in 36 genes spaced across an 18.3 Mb region. Further analyses demonstrated that the missense SNP rs2272996 (or N131S) in the VNN1 gene was significantly associated with hypertension in African Americans and the association was replicated in Mexican Americans; a non-significant opposite association was observed in European Americans. This SNP also accounted for most of the evidence observed in the admixture analysis on chromosome 6. Despite these encouraging results, susceptibility loci for hypertension have been exceptionally difficult to localize and confirmation by independent studies will be necessary to establish these findings. PMID:18043751

  16. Admixture mapping of genetic variants for uterine fibroids.

    PubMed

    Zhang, Kui; Wiener, Howard; Aissani, Brahim

    2015-09-01

    Uterine leiomyoma (UL) are benign neoplasms arising from the smooth muscle cells of the uterus. One of the established risk factors for UL is African American ethnicity. Studies have consistently shown that African Americans have two to three times higher risk compared with that of non-Hispanic Whites. However, there is still no adequate explanation for the higher risk among African Americans. To investigate the genetic contribution to the observed difference between the African American and European American populations, we conducted an admixture scan in 525 eligible African American women participants to the NIEHS uterine fibroid study (NIEHS-UFS). In models with no stratification, we found multiple genomic regions showing significant and suggestive evidence of association, with chromosomal band 2q32.2 at rs256552 showing the highest score (Z-score=7.86, Bonferroni adjusted P-value=5.5 × 10(-12)) consistent with the suggestive evidence reported for this genomic region in the Black Women's Health Study. However, in models stratified by the body mass index (BMI) covariate, chromosome 1q42.2 was the sole genomic region that consistently showed suggestive associations across the BMI categories tested (Z-scores ⩽-3.96, Bonferroni adjusted P-values ⩽0.107). In age-stratified models, a significant association was observed in the older category (age >40) reaching a Z-score of 6.44 (Bonferroni-adjusted P-value=1.64 × 10(-7)) at rs256552. The mean percentage of European ancestry among cases was lower than that among controls in the NIEHS-UFS study. However, our study did not show a significant association between mean percentage of European ancestry and UL. PMID:26040208

  17. Admixture mapping of genetic variants for uterine fibroids

    PubMed Central

    Zhang, Kui; Wiener, Howard; Aissani, Brahim

    2015-01-01

    Uterine leiomyoma (UL) are benign neoplasms arising from the smooth muscle cells of the uterus. One of the established risk factors for UL is African American ethnicity. Studies have consistently shown that African Americans have 2-3 times higher risk compared with that of non-Hispanic Whites. However, there is still no adequate explanation for the higher risk among African Americans. To investigate the genetic contribution to the observed difference between the African American and European American populations, we conducted an admixture scan in 525 eligible African American women participants to the NIEHS uterine fibroid study (NIEHS-UFS). In models with no stratification, we found multiple genomic regions showing significant and suggestive evidence of association, with chromosomal band 2q32.2 at rs256552 showing the highest score (Z-score = 7.86, Bonferroni adjusted p-value = 5.5×10-12) consistent with the suggestive evidence reported for this genomic region in the Black Women's Health Study. However, in models stratified by the body mass index (BMI) covariate, chromosomal 1q42.2 was the sole genomic region that consistently showed suggestive associations across the BMI categories tested (Z-scores ≤ -3.96, Bonferroni adjusted p-values ≤ 0.107). In age-stratified models, a significant association was observed in the older category (age > 40) reaching a Z-score of 6.44 (Bonferroni-adjusted p-value = 1.64 × 10-7) at rs256552. The mean percentage of European ancestry among cases was lower than that among controls in the NIEHS-UFS study. However, our study did not show a significant association between mean percentage of European ancestry and UL. PMID:26040208

  18. Ethnic-Difference Markers for Use in Mapping by Admixture Linkage Disequilibrium

    PubMed Central

    Collins-Schramm, Heather E.; Phillips, Carolyn M.; Operario, Darwin J.; Lee, Jane S.; Weber, James L.; Hanson, Robert L.; Knowler, William C.; Cooper, Richard; Li, Hongzhe; Seldin, Michael F.

    2002-01-01

    Mapping by admixture linkage disequilibrium (MALD) is a potentially powerful technique for the mapping of complex genetic diseases. The practical requirements of this method include (a) a set of markers spanning the genome that have large allele-frequency differences between the parental ethnicities contributing to the admixed population and (b) an understanding of the extent of admixture in the study population. To this end, a DNA-pooling technique was used to screen microsatellite and diallelic insertion/deletion markers for allele-frequency differences between putative representatives of the parental populations of the admixed Mexican American (MA) and African American (AA) populations. Markers with promising pooled differences were then confirmed by individual genotyping in both the parental and admixed populations. For the MA population, screening of >600 markers identified 151 ethnic-difference markers (EDMs) with δ>0.30 (where δ is the absolute value of each allele-frequency difference between two populations, summed over all marker alleles and divided by two) that are likely to be useful for MALD analysis. For the AA population, analysis of >400 markers identified 97 EDMs. In addition, individual genotyping of these markers in Pima Amerindians, Yavapai Amerindians, European American (EA) individuals, Africans from Zimbabwe, MA individuals, and AA individuals, as well as comparison to the CEPH genotyping set, suggests that the differences between subpopulations of an ethnicity are small for many markers with large interethnic differences. Estimates of admixture that are based on individual genotyping of these markers are consistent with a 60% EA:40% Amerindian contribution to MA populations and with a 20% EA:80% African contribution to AA populations. Taken together, these data suggest that EDMs with large interpopulation and small intrapopulation differences can be readily identified for MALD studies in both AA and MA populations. PMID:11845411

  19. Admixture Aberration Analysis: Application to Mapping in Admixed Population Using Pooled DNA

    NASA Astrophysics Data System (ADS)

    Bercovici, Sivan; Geiger, Dan

    Admixture mapping is a gene mapping approach used for the identification of genomic regions harboring disease susceptibility genes in the case of recently admixed populations such as African Americans. We present a novel method for admixture mapping, called admixture aberration analysis (AAA), that uses a DNA pool of affected admixed individuals. We demonstrate through simulations that AAA is a powerful and economical mapping method under a range of scenarios, capturing complex human diseases such as hypertension and end stage kidney disease. The method has a low false-positive rate and is robust to deviation from model assumptions. Finally, we apply AAA on 600 prostate cancer-affected African Americans, replicating a known risk locus. Simulation results indicate that the method can yield over 96% reduction in genotyping. Our method is implemented as a Java program called AAAmap and is freely available.

  20. Admixture mapping identifies introgressed genomic regions in North American canids.

    PubMed

    vonHoldt, Bridgett M; Kays, Roland; Pollinger, John P; Wayne, Robert K

    2016-06-01

    Hybrid zones typically contain novel gene combinations that can be tested by natural selection in a unique genetic context. Parental haplotypes that increase fitness can introgress beyond the hybrid zone, into the range of parental species. We used the Affymetrix canine SNP genotyping array to identify genomic regions tagged by multiple ancestry informative markers that are more frequent in an admixed population than expected. We surveyed a hybrid zone formed in the last 100 years as coyotes expanded their range into eastern North America. Concomitant with expansion, coyotes hybridized with wolves and some populations became more wolflike, such that coyotes in the northeast have the largest body size of any coyote population. Using a set of 3102 ancestry informative markers, we identified 60 differentially introgressed regions in 44 canines across this admixture zone. These regions are characterized by an excess of exogenous ancestry and, in northeastern coyotes, are enriched for genes affecting body size and skeletal proportions. Further, introgressed wolf-derived alleles have penetrated into Southern US coyote populations. Because no wolves currently exist in this area, these alleles are unlikely to have originated from recent hybridization. Instead, they probably originated from intraspecific gene flow or ancient admixture. We show that grey wolf and coyote admixture has far-reaching effects and, in addition to phenotypically transforming admixed populations, allows for the differential movement of alleles from different parental species to be tested in new genomic backgrounds. PMID:27106273

  1. Mapping by admixture linkage disequilibrium in human populations: limits and guidelines.

    PubMed Central

    Stephens, J. C.; Briscoe, D.; O'Brien, S. J.

    1994-01-01

    Certain human hereditary conditions, notably those with low penetrance and those which require an environmental event such as infectious disease exposure, are difficult to localize in pedigree analysis, because of uncertainty in the phenotype of an affected patient's relatives. An approach to locating these genes in human cohort studies would be to use association analysis, which depends on linkage disequilibrium of flanking polymorphic DNA markers. In theory, a high degree of linkage disequilibrium between genes separated by 10-20 cM will be generated and persist in populations that have a history of recent (3-20 generations ago) admixture between genetically differentiated racial groups, such as has occurred in African Americans and Hispanic populations. We have conducted analytic and computer simulations to quantify the effect of genetic, genomic, and population parameters that affect the amount and ascertainment of linkage disequilibrium in populations with a history of genetic admixture. Our goal is to thoroughly explore the ranges of all relevant parameters or factors (e.g., sample size and degree of genetic differentiation between populations) that may be involved in gene localization studies, in hopes of prescribing guidelines for an efficient mapping strategy. The results provide reasonable limits on sample size (200-300 patients), marker number (200-300 in 20-cM intervals), and allele differentiation (loci with allele frequency difference of > or = .3 between admixed parent populations) to produce an efficient approach (> 95% ascertainment) for locating genes not easily tracked in human pedigrees. PMID:7942858

  2. Analysis of Genomic Admixture in Uyghur and Its Implication in Mapping Strategy

    PubMed Central

    Xu, Shuhua; Huang, Wei; Qian, Ji; Jin, Li

    2008-01-01

    The Uyghur (UIG) population, settled in Xinjiang, China, is a population presenting a typical admixture of Eastern and Western anthropometric traits. We dissected its genomic structure at population level, individual level, and chromosome level by using 20,177 SNPs spanning nearly the entire chromosome 21. Our results showed that UIG was formed by two-way admixture, with 60% European ancestry and 40% East Asian ancestry. Overall linkage disequilibrium (LD) in UIG was similar to that in its parental populations represented in East Asia and Europe with regard to common alleles, and UIG manifested elevation of LD only within 500 kb and at a level of 0.1 < r2 < 0.8 when ancestry-informative markers (AIMs) were used. The size of chromosomal segments that were derived from East Asian and European ancestries averaged 2.4 cM and 4.1 cM, respectively. Both the magnitude of LD and fragmentary ancestral chromosome segments indicated a long history of Uyghur. Under the assumption of a hybrid isolation (HI) model, we estimated that the admixture event of UIG occurred about 126 [107∼146] generations ago, or 2520 [2140∼2920] years ago assuming 20 years per generation. In spite of the long history and short LD of Uyghur compared with recent admixture populations such as the African-American population, we suggest that mapping by admixture LD (MALD) is still applicable in the Uyghur population but ∼10-fold AIMs are necessary for a whole-genome scan. PMID:18355773

  3. Admixture mapping and subsequent fine-mapping suggests a biologically relevant and novel association on chromosome 11 for type 2 diabetes in African Americans.

    PubMed

    Jeff, Janina M; Armstrong, Loren L; Ritchie, Marylyn D; Denny, Joshua C; Kho, Abel N; Basford, Melissa A; Wolf, Wendy A; Pacheco, Jennifer A; Li, Rongling; Chisholm, Rex L; Roden, Dan M; Hayes, M Geoffrey; Crawford, Dana C

    2014-01-01

    Type 2 diabetes (T2D) is a complex metabolic disease that disproportionately affects African Americans. Genome-wide association studies (GWAS) have identified several loci that contribute to T2D in European Americans, but few studies have been performed in admixed populations. We first performed a GWAS of 1,563 African Americans from the Vanderbilt Genome-Electronic Records Project and Northwestern University NUgene Project as part of the electronic Medical Records and Genomics (eMERGE) network. We successfully replicate an association in TCF7L2, previously identified by GWAS in this African American dataset. We were unable to identify novel associations at p<5.0×10(-8) by GWAS. Using admixture mapping as an alternative method for discovery, we performed a genome-wide admixture scan that suggests multiple candidate genes associated with T2D. One finding, TCIRG1, is a T-cell immune regulator expressed in the pancreas and liver that has not been previously implicated for T2D. We performed subsequent fine-mapping to further assess the association between TCIRG1 and T2D in >5,000 African Americans. We identified 13 independent associations between TCIRG1, CHKA, and ALDH3B1 genes on chromosome 11 and T2D. Our results suggest a novel region on chromosome 11 identified by admixture mapping is associated with T2D in African Americans. PMID:24595071

  4. Admixture mapping identifies 8q24 as a prostate cancer risk locus in African-American men

    PubMed Central

    Freedman, Matthew L.; Haiman, Christopher A.; Patterson, Nick; McDonald, Gavin J.; Tandon, Arti; Waliszewska, Alicja; Penney, Kathryn; Steen, Robert G.; Ardlie, Kristin; John, Esther M.; Oakley-Girvan, Ingrid; Whittemore, Alice S.; Cooney, Kathleen A.; Ingles, Sue A.; Altshuler, David; Henderson, Brian E.; Reich, David

    2006-01-01

    A whole-genome admixture scan in 1,597 African Americans identified a 3.8 Mb interval on chromosome 8q24 as significantly associated with susceptibility to prostate cancer [logarithm of odds (LOD) = 7.1]. The increased risk because of inheriting African ancestry is greater in men diagnosed before 72 years of age (P < 0.00032) and may contribute to the epidemiological observation that the higher risk for prostate cancer in African Americans is greatest in younger men (and attenuates with older age). The same region was recently identified through linkage analysis of prostate cancer, followed by fine-mapping. We strongly replicated this association (P < 4.2 × 10−9) but find that the previously described alleles do not explain more than a fraction of the admixture signal. Thus, admixture mapping indicates a major, still-unidentified risk gene for prostate cancer at 8q24, motivating intense work to find it. PMID:16945910

  5. Intrahepatic Cholestasis of Pregnancy (ICP) in U.S. Latinas and Chileans: Clinical features, Ancestry Analysis, and Admixture Mapping.

    PubMed

    Bull, Laura N; Hu, Donglei; Shah, Sohela; Temple, Luisa; Silva, Karla; Huntsman, Scott; Melgar, Jennifer; Geiser, Mary T; Sanford, Ukina; Ortiz, Juan A; Lee, Richard H; Kusanovic, Juan P; Ziv, Elad; Vargas, Juan E

    2015-01-01

    In the Americas, women with Indigenous American ancestry are at increased risk of intrahepatic cholestasis of pregnancy (ICP), relative to women of other ethnicities. We hypothesized that ancestry-related genetic factors contribute to this increased risk. We collected clinical and laboratory data, and performed biochemical assays on samples from U.S. Latinas and Chilean women, with and without ICP. The study sample included 198 women with ICP (90 from California, U.S., and 108 from Chile) and 174 pregnant control women (69 from California, U.S., and 105 from Chile). SNP genotyping was performed using Affymetrix arrays. We compared overall genetic ancestry between cases and controls, and used a genome-wide admixture mapping approach to screen for ICP susceptibility loci. We identified commonalities and differences in features of ICP between the 2 countries and determined that cases had a greater proportion of Indigenous American ancestry than did controls (p = 0.034). We performed admixture mapping, taking country of origin into account, and identified one locus for which Native American ancestry was associated with increased risk of ICP at a genome-wide level of significance (P = 3.1 x 10(-5), Pcorrected = 0.035). This locus has an odds ratio of 4.48 (95% CI: 2.21-9.06) for 2 versus zero Indigenous American chromosomes. This locus lies on chromosome 2, with a 10 Mb 95% confidence interval which does not contain any previously identified hereditary 'cholestasis genes.' Our results indicate that genetic factors contribute to the risk of developing ICP in the Americas, and support the utility of clinical and genetic studies of ethnically mixed populations for increasing our understanding of ICP. PMID:26126184

  6. Intrahepatic Cholestasis of Pregnancy (ICP) in U.S. Latinas and Chileans: Clinical features, Ancestry Analysis, and Admixture Mapping

    PubMed Central

    Bull, Laura N.; Hu, Donglei; Shah, Sohela; Temple, Luisa; Silva, Karla; Huntsman, Scott; Melgar, Jennifer; Geiser, Mary T.; Sanford, Ukina; Ortiz, Juan A.; Lee, Richard H.; Kusanovic, Juan P.

    2015-01-01

    In the Americas, women with Indigenous American ancestry are at increased risk of intrahepatic cholestasis of pregnancy (ICP), relative to women of other ethnicities. We hypothesized that ancestry-related genetic factors contribute to this increased risk. We collected clinical and laboratory data, and performed biochemical assays on samples from U.S. Latinas and Chilean women, with and without ICP. The study sample included 198 women with ICP (90 from California, U.S., and 108 from Chile) and 174 pregnant control women (69 from California, U.S., and 105 from Chile). SNP genotyping was performed using Affymetrix arrays. We compared overall genetic ancestry between cases and controls, and used a genome-wide admixture mapping approach to screen for ICP susceptibility loci. We identified commonalities and differences in features of ICP between the 2 countries and determined that cases had a greater proportion of Indigenous American ancestry than did controls (p = 0.034). We performed admixture mapping, taking country of origin into account, and identified one locus for which Native American ancestry was associated with increased risk of ICP at a genome-wide level of significance (P = 3.1 x 10-5, Pcorrected = 0.035). This locus has an odds ratio of 4.48 (95% CI: 2.21-9.06) for 2 versus zero Indigenous American chromosomes. This locus lies on chromosome 2, with a 10 Mb 95% confidence interval which does not contain any previously identified hereditary ‘cholestasis genes.’ Our results indicate that genetic factors contribute to the risk of developing ICP in the Americas, and support the utility of clinical and genetic studies of ethnically mixed populations for increasing our understanding of ICP. PMID:26126184

  7. A factorial design study on the physical stability of 3-in-1 admixtures.

    PubMed

    Li, L C; Sampogna, T P

    1993-11-01

    The effects of dextrose concentration, the compounding method, and storage conditions, on the physical stability of 3-in-1 admixtures were investigated using a 2n factorial design. The main effect of these three variables on the weight percent of oil globules larger than 5 microns (by HIAC) was found to be statistically significant. However, the effects of interaction amongst these variables, except the two-way interaction between dextrose concentration and storage conditions, were found to be statistically insignificant. A higher dextrose concentration was shown to enhance the physical stability of the admixtures, while low-temperature storage (three days at 5 degrees C) was more favourable for maintaining the physical stability of the admixtures with a low dextrose concentration. Although sequential pumping produced admixtures with a slightly lower final weight percentage of larger oil globules (> 5 microns), the method of compounding has the least impact on the physical stability of the admixtures in comparison with the other two variables evaluated in this study. The storage of the admixtures at room temperature for one day was shown to have a greater adverse effect on admixtures with a low dextrose concentration. PMID:7908042

  8. Admixture mapping of tuberculosis and pigmentation-related traits in an African–European hybrid cattle population

    PubMed Central

    Kassahun, Yonas; Mattiangeli, Valeria; Ameni, Gobena; Hailu, Elena; Aseffa, Abraham; Young, Douglas B.; Hewinson, R. Glyn; Vordermeier, H. Martin; Bradley, Daniel G.

    2015-01-01

    Admixture mapping affords a powerful approach to genetic mapping of complex traits and may be particularly suited to investigation in cattle where many breeds and populations are hybrids of the two divergent ancestral genomes, derived from Bos taurus and Bos indicus. Here we design a minimal genome wide SNP panel for tracking ancestry in recent hybrids of Holstein–Friesian and local Arsi zebu in a field sample from a region of high bovine tuberculosis (BTB) endemicity in the central Ethiopian highlands. We first demonstrate the utility of this approach by mapping the red coat color phenotype, uncovering a highly significant peak over the MC1R gene and a second peak with no previously known candidate gene. Secondly, we exploit the described differential susceptibility to BTB between the ancestral strains to identify a region in which Bos taurus ancestry associates, at suggestive significance, with skin test positivity. Interestingly, this association peak contains the toll-like receptor gene cluster on chromosome 6. With this work we have shown the potential of admixture mapping in hybrid domestic animals with divergent ancestral genomes, a recurring condition in domesticated species. PMID:26124773

  9. Experimental study on durability improvement of fly ash concrete with durability improving admixture.

    PubMed

    Quan, Hong-zhu; Kasami, Hideo

    2014-01-01

    In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%-20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized. PMID:25013870

  10. Experimental Study on Durability Improvement of Fly Ash Concrete with Durability Improving Admixture

    PubMed Central

    Quan, Hong-zhu; Kasami, Hideo

    2014-01-01

    In order to improve the durability of fly ash concrete, a series of experimental studies are carried out, where durability improving admixture is used to reduce drying shrinkage and improve freezing-thawing resistance. The effects of durability improving admixture, air content, water-binder ratio, and fly ash replacement ratio on the performance of fly ash concrete are discussed in this paper. The results show that by using durability improving admixture in nonair-entraining fly ash concrete, the compressive strength of fly ash concrete can be improved by 10%–20%, and the drying shrinkage is reduced by 60%. Carbonation resistance of concrete is roughly proportional to water-cement ratio regardless of water-binder ratio and fly ash replacement ratio. For the specimens cured in air for 2 weeks, the freezing-thawing resistance is improved. In addition, by making use of durability improving admixture, it is easier to control the air content and make fly ash concrete into nonair-entraining one. The quality of fly ash concrete is thereby optimized. PMID:25013870

  11. Admixture mapping in lupus identifies multiple functional variants within IFIH1 associated with apoptosis, inflammation, and autoantibody production.

    PubMed

    Molineros, Julio E; Maiti, Amit K; Sun, Celi; Looger, Loren L; Han, Shizhong; Kim-Howard, Xana; Glenn, Stuart; Adler, Adam; Kelly, Jennifer A; Niewold, Timothy B; Gilkeson, Gary S; Brown, Elizabeth E; Alarcón, Graciela S; Edberg, Jeffrey C; Petri, Michelle; Ramsey-Goldman, Rosalind; Reveille, John D; Vilá, Luis M; Freedman, Barry I; Tsao, Betty P; Criswell, Lindsey A; Jacob, Chaim O; Moore, Jason H; Vyse, Timothy J; Langefeld, Carl L; Guthridge, Joel M; Gaffney, Patrick M; Moser, Kathy L; Scofield, R Hal; Alarcón-Riquelme, Marta E; Williams, Scott M; Merrill, Joan T; James, Judith A; Kaufman, Kenneth M; Kimberly, Robert P; Harley, John B; Nath, Swapan K

    2013-01-01

    Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease with a strong genetic component. African-Americans (AA) are at increased risk of SLE, but the genetic basis of this risk is largely unknown. To identify causal variants in SLE loci in AA, we performed admixture mapping followed by fine mapping in AA and European-Americans (EA). Through genome-wide admixture mapping in AA, we identified a strong SLE susceptibility locus at 2q22-24 (LOD=6.28), and the admixture signal is associated with the European ancestry (ancestry risk ratio ~1.5). Large-scale genotypic analysis on 19,726 individuals of African and European ancestry revealed three independently associated variants in the IFIH1 gene: an intronic variant, rs13023380 [P(meta) = 5.20×10(-14); odds ratio, 95% confidence interval = 0.82 (0.78-0.87)], and two missense variants, rs1990760 (Ala946Thr) [P(meta) = 3.08×10(-7); 0.88 (0.84-0.93)] and rs10930046 (Arg460His) [P(dom) = 1.16×10(-8); 0.70 (0.62-0.79)]. Both missense variants produced dramatic phenotypic changes in apoptosis and inflammation-related gene expression. We experimentally validated function of the intronic SNP by DNA electrophoresis, protein identification, and in vitro protein binding assays. DNA carrying the intronic risk allele rs13023380 showed reduced binding efficiency to a cellular protein complex including nucleolin and lupus autoantigen Ku70/80, and showed reduced transcriptional activity in vivo. Thus, in SLE patients, genetic susceptibility could create a biochemical imbalance that dysregulates nucleolin, Ku70/80, or other nucleic acid regulatory proteins. This could promote antibody hypermutation and auto-antibody generation, further destabilizing the cellular network. Together with molecular modeling, our results establish a distinct role for IFIH1 in apoptosis, inflammation, and autoantibody production, and explain the molecular basis of these three risk alleles for SLE pathogenesis. PMID:23441136

  12. Admixture Mapping in Lupus Identifies Multiple Functional Variants within IFIH1 Associated with Apoptosis, Inflammation, and Autoantibody Production

    PubMed Central

    Looger, Loren L.; Han, Shizhong; Kim-Howard, Xana; Glenn, Stuart; Adler, Adam; Kelly, Jennifer A.; Niewold, Timothy B.; Gilkeson, Gary S.; Brown, Elizabeth E.; Alarcón, Graciela S.; Edberg, Jeffrey C.; Petri, Michelle; Ramsey-Goldman, Rosalind; Reveille, John D.; Vilá, Luis M.; Freedman, Barry I.; Tsao, Betty P.; Criswell, Lindsey A.; Jacob, Chaim O.; Moore, Jason H.; Vyse, Timothy J.; Langefeld, Carl L.; Guthridge, Joel M.; Gaffney, Patrick M.; Moser, Kathy L.; Scofield, R. Hal; Alarcón-Riquelme, Marta E.; Williams, Scott M.; Merrill, Joan T.; James, Judith A.; Kaufman, Kenneth M.; Kimberly, Robert P.; Harley, John B.; Nath, Swapan K.

    2013-01-01

    Systemic lupus erythematosus (SLE) is an inflammatory autoimmune disease with a strong genetic component. African-Americans (AA) are at increased risk of SLE, but the genetic basis of this risk is largely unknown. To identify causal variants in SLE loci in AA, we performed admixture mapping followed by fine mapping in AA and European-Americans (EA). Through genome-wide admixture mapping in AA, we identified a strong SLE susceptibility locus at 2q22–24 (LOD = 6.28), and the admixture signal is associated with the European ancestry (ancestry risk ratio ∼1.5). Large-scale genotypic analysis on 19,726 individuals of African and European ancestry revealed three independently associated variants in the IFIH1 gene: an intronic variant, rs13023380 [Pmeta = 5.20×10−14; odds ratio, 95% confidence interval = 0.82 (0.78–0.87)], and two missense variants, rs1990760 (Ala946Thr) [Pmeta = 3.08×10−7; 0.88 (0.84–0.93)] and rs10930046 (Arg460His) [Pdom = 1.16×10−8; 0.70 (0.62–0.79)]. Both missense variants produced dramatic phenotypic changes in apoptosis and inflammation-related gene expression. We experimentally validated function of the intronic SNP by DNA electrophoresis, protein identification, and in vitro protein binding assays. DNA carrying the intronic risk allele rs13023380 showed reduced binding efficiency to a cellular protein complex including nucleolin and lupus autoantigen Ku70/80, and showed reduced transcriptional activity in vivo. Thus, in SLE patients, genetic susceptibility could create a biochemical imbalance that dysregulates nucleolin, Ku70/80, or other nucleic acid regulatory proteins. This could promote antibody hypermutation and auto-antibody generation, further destabilizing the cellular network. Together with molecular modeling, our results establish a distinct role for IFIH1 in apoptosis, inflammation, and autoantibody production, and explain the molecular basis of these three risk alleles for SLE pathogenesis. PMID

  13. Understanding admixture patterns in supplemented populations: a case study combining molecular analyses and temporally explicit simulations in Atlantic salmon

    PubMed Central

    Perrier, Charles; Baglinière, Jean-Luc; Evanno, Guillaume

    2013-01-01

    Genetic admixture between wild and introduced populations is a rising concern for the management of endangered species. Here, we use a dual approach based on molecular analyses of samples collected before and after hatchery fish introduction in combination with a simulation study to obtain insight into the mechanisms of admixture in wild populations. Using 17 microsatellites, we genotyped pre- and post-stocking samples from four Atlantic salmon populations supplemented with non-native fish to estimate genetic admixture. We also used individual-based temporally explicit simulations based on realistic demographic and stocking data to predict the extent of admixture. We found a low admixture by hatchery stocks within prestocking samples but moderate to high values in post-stocking samples (from 12% to 60%). The simulation scenarios best fitting the real data suggested a 10–25 times lower survival of stocked fish relative to wild individuals. Simulations also suggested relatively high dispersal rates of stocked and wild fish, which may explain some high levels of admixture in weakly stocked populations and the persistence of indigenous genotypes in heavily stocked populations. This study overall demonstrates that combining genetic analyses with simulations can significantly improve the understanding of admixture mechanisms in wild populations. PMID:23798972

  14. Mapping genes that underlie ethnic differences in disease risk: methods for detecting linkage in admixed populations, by conditioning on parental admixture.

    PubMed

    McKeigue, P M

    1998-07-01

    Genes that underlie ethnic differences in disease risk can be mapped in affected individuals of mixed descent if the ancestry of the alleles at each marker locus can be assigned to one of the two founding populations. Linkage can be detected by testing for association of the disease with the ancestry of alleles at the marker locus, by conditioning on the admixture (defined as the proportion of genes that have ancestry from the high-risk population) of both parents. With regard to exploiting the effects of admixture, this test is more flexible and powerful than the transmission-disequilibrium test. Under the assumption of a multiplicative model, the statistical power for a given sample size depends only on parental admixture and the risk ratio r between populations that is generated by the locus. The most informative families are those in which mean parental admixture is .2-.7 and in which admixture is similar in both parents. The number of markers required for a genome search depends on the number of generations since admixture and on the information content for ancestry (f) of the markers, defined as a function of allele frequencies in the two founding populations. Simulations using a hidden Markov model suggest that, when admixture has occurred 2-10 generations earlier, a multipoint analysis using 2,000 biallelic markers, with f values of 30%, can extract 70%-90% of the ancestry information for each locus. Sets of such markers could be selected from libraries of single-nucleotide polymorphisms, when these become available. PMID:9634509

  15. Mitochondrial DNA studies show asymmetrical Amerindian admixture in Afro-Colombian and Mestizo populations.

    PubMed

    Rodas, Clemencia; Gelvez, Nancy; Keyeux, Genoveva

    2003-02-01

    The origin of the African populations that arrived on the Colombian coasts at the time of the Spanish conquest and their subsequent settlement throughout the country and interaction with Amerindian and Spanish populations are features that can be analyzed through the study of mitochondrial DNA (mtDNA) markers. For this purpose, the present study investigates the admixture between these populations by analyzing the markers defining the main (A, B, C, D) and minor (X) founder haplogroups in Native Americans, the principal African haplogroup (L), and additional generic markers present in Caucasian (I, J, K, H, T, U, V, W) and minor African lineages (L3). As part of an interdisciplinary research program (the Expedición Humana, furthered by the Universidad Javeriana and directed by J.E. Bernal V.), 159 Afro-Colombians from five populations in which they are the majority and 91 urban Mestizos were studied. No Amerindian haplogroups (A-D, X) were detected in 81% of the Afro-Colombians. In those samples with Amerindian lineages (average 18.8%, with a range from 10% to 43%), haplogroup B predominated. When analyzed for the presence of African haplotypes, Afro-Colombians showed an overall frequency of 35.8% for haplogroup L mtDNAs, although with broad differences between populations. A few Afro-Colombian samples (1.9%) had mutations that have not been described before, and might therefore be considered as previously unsampled African variants or as new mutations arising in the American continent. Conversely, in Mestizos less than 22% of their mtDNAs belonged to non-Amerindian lineages, of which most were likely to be West Eurasian in origin. Haplogroup L mtDNAs were found in only one Mestizo (1.1%), indicating that, if present, admixture with African women would bring in other, rarer African lineages. On the other hand, in an accompanying paper (Keyeux et al. 2002) we have shown that Amerindians from Colombia have experienced little or no matrilineal admixture with

  16. CYP2C9 and VKORC1 Genotypes in Puerto Ricans: A Case for Admixture-Matching in Clinical Pharmacogenetic Studies

    PubMed Central

    Villagra, David; Duconge, Jorge; Windemuth, Andreas; Cadilla, Carmen L; Kocherla, Mohan; Gorowski, Krystyna; Bogaard, Kali; Renta, Jessica Y; Cruz, Irelys A; Mirabal, Sara; Seip, Richard L; Ruaño, Gualberto

    2010-01-01

    Backgrounds Admixture is of great relevance to the clinical application of pharmacogenetics and personalized medicine, but unfortunately these studies have been scarce in Puerto Ricans. Besides, allele frequencies for clinically relevant genetic markers in warfarin response (i.e., CYP2C9 and VKORC1) have not yet been fully characterized in this population. Accordingly, this study is aimed at investigating whether a correlation between overall genetic similarity and CYP2C9 and/or VKORC1 genotypes could be established. Methods 98 DNA samples from Puerto Ricans were genotyped for major CYP2C9 and VKORC1 polymorphisms and tested on a physiogenomic (PG)-array to infer population structure and admixture pattern. Results Analysis affirmed that Puerto Ricans are broadly admixed. A genetic distance dendrogram was constructed by clustering those subjects with similar genetic profiles. Individual VKORC1 and CYP2C9 genotypes were visually overlaid atop the three dendrogram sectors. Sector-1, representing Amerindian ancestry, showed higher VKORC1-1639G>A variant frequency than the rest of the population (p=0.051). Although CYP2C9*3 allele frequencies matched the expected HapMap values, admixture may explain deviations from published findings regarding VKORC1-1639G>A and CYP2C9*2 allele frequencies in sector-3. Conclusions Results suggest that the observed inter-individual variations in ancestral contributions have significant implications for the way each Puerto Rican responds to warfarin therapy. Our findings provide valuable evidence on the importance of controlling for admixture in pharmacogenetic studies of Puerto Rican Hispanics. PMID:20488169

  17. Geographic Patterns of Genome Admixture in Latin American Mestizos

    PubMed Central

    Wang, Sijia; Ray, Nicolas; Rojas, Winston; Parra, Maria V.; Bedoya, Gabriel; Gallo, Carla; Poletti, Giovanni; Hill, Kim; Hurtado, Ana M.; Camrena, Beatriz; Nicolini, Humberto; Klitz, William; Barrantes, Ramiro; Molina, Julio A.; Freimer, Nelson B.; Bortolini, Maria Cátira; Salzano, Francisco M.; Petzl-Erler, Maria L.; Tsuneto, Luiza T.; Dipierri, José E.; Alfaro, Emma L.; Bailliet, Graciela; Bianchi, Nestor O.; Llop, Elena; Rothhammer, Francisco; Excoffier, Laurent; Ruiz-Linares, Andrés

    2008-01-01

    The large and diverse population of Latin America is potentially a powerful resource for elucidating the genetic basis of complex traits through admixture mapping. However, no genome-wide characterization of admixture across Latin America has yet been attempted. Here, we report an analysis of admixture in thirteen Mestizo populations (i.e. in regions of mainly European and Native settlement) from seven countries in Latin America based on data for 678 autosomal and 29 X-chromosome microsatellites. We found extensive variation in Native American and European ancestry (and generally low levels of African ancestry) among populations and individuals, and evidence that admixture across Latin America has often involved predominantly European men and both Native and African women. An admixture analysis allowing for Native American population subdivision revealed a differentiation of the Native American ancestry amongst Mestizos. This observation is consistent with the genetic structure of pre-Columbian populations and with admixture having involved Natives from the area where the Mestizo examined are located. Our findings agree with available information on the demographic history of Latin America and have a number of implications for the design of association studies in population from the region. PMID:18369456

  18. The Complex Admixture History and Recent Southern Origins of Siberian Populations.

    PubMed

    Pugach, Irina; Matveev, Rostislav; Spitsyn, Viktor; Makarov, Sergey; Novgorodov, Innokentiy; Osakovsky, Vladimir; Stoneking, Mark; Pakendorf, Brigitte

    2016-07-01

    Although Siberia was inhabited by modern humans at an early stage, there is still debate over whether it remained habitable during the extreme cold of the Last Glacial Maximum or whether it was subsequently repopulated by peoples with recent shared ancestry. Previous studies of the genetic history of Siberian populations were hampered by the extensive admixture that appears to have taken place among these populations, because commonly used methods assume a tree-like population history and at most single admixture events. Here we analyze geogenetic maps and use other approaches to distinguish the effects of shared ancestry from prehistoric migrations and contact, and develop a new method based on the covariance of ancestry components, to investigate the potentially complex admixture history. We furthermore adapt a previously devised method of admixture dating for use with multiple events of gene flow, and apply these methods to whole-genome genotype data from over 500 individuals belonging to 20 different Siberian ethnolinguistic groups. The results of these analyses indicate that there have been multiple layers of admixture detectable in most of the Siberian populations, with considerable differences in the admixture histories of individual populations. Furthermore, most of the populations of Siberia included here, even those settled far to the north, appear to have a southern origin, with the northward expansions of different populations possibly being driven partly by the advent of pastoralism, especially reindeer domestication. These newly developed methods to analyze multiple admixture events should aid in the investigation of similarly complex population histories elsewhere. PMID:26993256

  19. The Complex Admixture History and Recent Southern Origins of Siberian Populations

    PubMed Central

    Pugach, Irina; Matveev, Rostislav; Spitsyn, Viktor; Makarov, Sergey; Novgorodov, Innokentiy; Osakovsky, Vladimir; Stoneking, Mark; Pakendorf, Brigitte

    2016-01-01

    Although Siberia was inhabited by modern humans at an early stage, there is still debate over whether it remained habitable during the extreme cold of the Last Glacial Maximum or whether it was subsequently repopulated by peoples with recent shared ancestry. Previous studies of the genetic history of Siberian populations were hampered by the extensive admixture that appears to have taken place among these populations, because commonly used methods assume a tree-like population history and at most single admixture events. Here we analyze geogenetic maps and use other approaches to distinguish the effects of shared ancestry from prehistoric migrations and contact, and develop a new method based on the covariance of ancestry components, to investigate the potentially complex admixture history. We furthermore adapt a previously devised method of admixture dating for use with multiple events of gene flow, and apply these methods to whole-genome genotype data from over 500 individuals belonging to 20 different Siberian ethnolinguistic groups. The results of these analyses indicate that there have been multiple layers of admixture detectable in most of the Siberian populations, with considerable differences in the admixture histories of individual populations. Furthermore, most of the populations of Siberia included here, even those settled far to the north, appear to have a southern origin, with the northward expansions of different populations possibly being driven partly by the advent of pastoralism, especially reindeer domestication. These newly developed methods to analyze multiple admixture events should aid in the investigation of similarly complex population histories elsewhere. PMID:26993256

  20. Human Population Admixture in Asia

    PubMed Central

    2012-01-01

    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. PMID:23166524

  1. Native American admixture in the Quebec founder population.

    PubMed

    Moreau, Claudia; Lefebvre, Jean-François; Jomphe, Michèle; Bhérer, Claude; Ruiz-Linares, Andres; Vézina, Hélène; Roy-Gagnon, Marie-Hélène; Labuda, Damian

    2013-01-01

    For years, studies of founder populations and genetic isolates represented the mainstream of genetic mapping in the effort to target genetic defects causing Mendelian disorders. The genetic homogeneity of such populations as well as relatively homogeneous environmental exposures were also seen as primary advantages in studies of genetic susceptibility loci that underlie complex diseases. European colonization of the St-Lawrence Valley by a small number of settlers, mainly from France, resulted in a founder effect reflected by the appearance of a number of population-specific disease-causing mutations in Quebec. The purported genetic homogeneity of this population was recently challenged by genealogical and genetic analyses. We studied one of the contributing factors to genetic heterogeneity, early Native American admixture that was never investigated in this population before. Consistent admixture estimates, in the order of one per cent, were obtained from genome-wide autosomal data using the ADMIXTURE and HAPMIX software, as well as with the fastIBD software evaluating the degree of the identity-by-descent between Quebec individuals and Native American populations. These genomic results correlated well with the genealogical estimates. Correlations are imperfect most likely because of incomplete records of Native founders' origin in genealogical data. Although the overall degree of admixture is modest, it contributed to the enrichment of the population diversity and to its demographic stratification. Because admixture greatly varies among regions of Quebec and among individuals, it could have significantly affected the homogeneity of the population, which is of importance in mapping studies, especially when rare genetic susceptibility variants are in play. PMID:23776491

  2. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    SciTech Connect

    Wyrzykowski, Mateusz; Trtik, Pavel; Münch, Beat; Weiss, Jason; Vontobel, Peter; Lura, Pietro

    2015-07-15

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.

  3. Recent admixture in an Indian population of African ancestry.

    PubMed

    Narang, Ankita; Jha, Pankaj; Rawat, Vimal; Mukhopadhyay, Arijit; Mukhopadhayay, Arijit; Dash, Debasis; Basu, Analabha; Mukerji, Mitali

    2011-07-15

    Identification and study of genetic variation in recently admixed populations not only provides insight into historical population events but also is a powerful approach for mapping disease loci. We studied a population (OG-W-IP) that is of African-Indian origin and has resided in the western part of India for 500 years; members of this population are believed to be descendants of the Bantu-speaking population of Africa. We have carried out this study by using a set of 18,534 autosomal markers common between Indian, CEPH-HGDP, and HapMap populations. Principal-components analysis clearly revealed that the African-Indian population derives its ancestry from Bantu-speaking west-African as well as Indo-European-speaking north and northwest Indian population(s). STRUCTURE and ADMIXTURE analyses show that, overall, the OG-W-IPs derive 58.7% of their genomic ancestry from their African past and have very little inter-individual ancestry variation (8.4%). The extent of linkage disequilibrium also reveals that the admixture event has been recent. Functional annotation of genes encompassing the ancestry-informative markers that are closer in allele frequency to the Indian ancestral population revealed significant enrichment of biological processes, such as ion-channel activity, and cadherins. We briefly examine the implications of determining the genetic diversity of this population, which could provide opportunities for studies involving admixture mapping. PMID:21737057

  4. Drift, admixture, and selection in human evolution: A study with DNA polymorphisms

    SciTech Connect

    Boxcock, A.M.; Mountain, J.L.; Hebert, J.M.; Cavalli-Sforza, L.L. ); Kidd, J.R.; Kidd, K.K. ); Carotenuto, L. )

    1991-02-01

    Accuracy of evolutionary analysis of populations within a species requires the testing of a large number of genetic polymorphisms belonging to many loci. The authors report here a reconstruction of human differentiation based on 100 DNA polymorphisms tested in five populations from four continents. The results agree with earlier conclusions based on other classes of genetic markers but reveal that Europeans do not fit a simple model of independently evolving populations with equal evolutionary rates. Evolutionary models involving early admixture are compatible with the data. Taking one such model into account they examined through simulation whether random genetic drift alone might explain the variation among gene frequencies across populations and genes. A measur eof variation among populations was calculated for each polymorphism, and its distribution for the 100 polymorphisms was compared with that expected for a drift-only hypothesis. At least two-thirds of the polymorphisms appear to be selectively neutral, but there are significant deviations at the two ends of the observed distribution of the measure variation: a slight excess of polymorphisms with low variation and a greater excess with high variation. This indicates that a few DNA polymorphisms are affected by natural selection, rarely heterotic, and more often disruptive, while most are selectively neutral.

  5. Interaction of heparin sodium and dopamine hydrochloride in admixtures studied by microcalorimetry.

    PubMed

    Pereira-Rosario, R; Utamura, T; Perrin, J H

    1988-06-01

    Microcalorimetry was used to investigate the interaction between dopamine hydrochloride and heparin sodium in 5% dextrose injection and in 0.9% sodium chloride injection. Heat of reaction (in microjoules) was measured by flow calorimetry for the following combinations of solutions: dopamine hydrochloride solution and heparin sodium solution prepared from powdered forms of the drugs in water; solutions of the powdered drugs in 5% dextrose injection; solutions of the powdered drugs in 0.9% sodium chloride injection; solutions prepared in 5% dextrose injection from commercial dopamine hydrochloride injection and commercial heparin sodium injection; and solutions prepared in 0.9% sodium chloride injection from the commercial drug injections. Mixing the solutions of the powdered drugs in water caused heat to be evolved, as did mixing the solutions of the powdered drugs diluted with 5% dextrose injection and the commercial injections diluted with 5% dextrose injection. The interactions of the two drugs were believed to be ionic, based on the exothermic nature of the reaction. No heat of reaction was measurable when sodium chloride was used as the diluent. Based on this preliminary investigation, admixtures containing heparin sodium and dopamine hydrochloride should be mixed in 0.9% sodium chloride injection to minimize the risk of interaction between the two drugs. PMID:3414704

  6. Drift, admixture, and selection in human evolution: a study with DNA polymorphisms.

    PubMed Central

    Bowcock, A M; Kidd, J R; Mountain, J L; Hebert, J M; Carotenuto, L; Kidd, K K; Cavalli-Sforza, L L

    1991-01-01

    Accuracy of evolutionary analysis of populations within a species requires the testing of a large number of genetic polymorphisms belonging to many loci. We report here a reconstruction of human differentiation based on 100 DNA polymorphisms tested in five populations from four continents. The results agree with earlier conclusions based on other classes of genetic markers but reveal that Europeans do not fit a simple model of independently evolving populations with equal evolutionary rates. Evolutionary models involving early admixture are compatible with the data. Taking one such model into account, we examined through simulation whether random genetic drift alone might explain the variation among gene frequencies across populations and genes. A measure of variation among populations was calculated for each polymorphism, and its distribution for the 100 polymorphisms was compared with that expected for a drift-only hypothesis. At least two-thirds of the polymorphisms appear to be selectively neutral, but there are significant deviations at the two ends of the observed distribution of the measure of variation: a slight excess of polymorphisms with low variation and a greater excess with high variation. This indicates that a few DNA polymorphisms are affected by natural selection, rarely heterotic, and more often disruptive, while most are selectively neutral. Images PMID:1992475

  7. Studies on growth, structural, dielectric, laser damage threshold, linear and nonlinear optical properties of methylene blue admixtured L-arginine phosphate single crystal

    NASA Astrophysics Data System (ADS)

    Peramaiyan, G.; Pandi, P.; Bhagavannarayana, G.; Mohan Kumar, R.

    2012-12-01

    L-Arginine phosphate (LAP) and methylene blue dye admixtured L-arginine phosphate single crystals were grown by slow cooling technique and their cell parameters, crystalline perfection, dopant inclusion were confirmed by single crystal, powder X-ray diffraction and high resolution X-ray diffraction analyses respectively. The modes of vibrations of different functional groups present in pure and dye admixtured LAP crystals have been identified by FTIR spectral analysis. The UV-Vis-NIR spectral study was performed on the grown crystals and found that the crystals are transparent in the entire visible-NIR region. The dielectric measurement was carried out on the grown crystals as a function of frequency at room temperature. The microhardness hardness study on (1 0 0) plane of grown crystals reveals the mechanical behavior of the crystals. The laser damage threshold value significantly enhanced for dye admixtured crystal in comparison with pure LAP crystal. The relative SHG efficiency of methylane blue admixtured LAP crystal was found to be 1.3 times higher than that of pure LAP crystal.

  8. A multicenter study of biological effects assessment of pharmacy workers occupationally exposed to antineoplastic drugs in Pharmacy Intravenous Admixture Services.

    PubMed

    Zhang, Jingjing; Bao, Jianan; Wang, Renying; Geng, Zhou; Chen, Yao; Liu, Xinchun; Xie, Yongzhong; Jiang, Ling; Deng, Yufei; Liu, Gaolin; Xu, Rong; Miao, Liyan

    2016-09-01

    This multi-centered study was designed to evaluate the biological effects of exposure to antineoplastic drugs (ADs) at PIVAS (Pharmacy Intravenous Admixture Service) across ten Chinese hospitals. 8-hydroxy-2-deoxyguanosine (8-OHdG) was used as a biomarker of DNA oxidative damage and lymphocyte apoptosis assays using peripheral lymphocyte cells were used to detect primary DNA damage. The mutagenicity activity was estimated with the Ames fluctuation test. 158 exposed and 143 unexposed workers participated in this study. The urinary 8-OHdG/Cr concentrations of the exposed group was 22.05±17.89ng/mg Cr, which was significantly higher than controls of 17.36±13.50ng/mg Cr (P<0.05). The rate of early lymphocyte apoptosis was slightly increased in exposed group than that of the control group (P=0.087). The mutagenic activity was significantly higher in the exposed group relative to the control group (P<0.05). Moreover, while no statistically significant difference was observed, higher concentrations of 8-OHdG/Cr in urine and an early lymphocyte apoptosis rate were found in exposed group II as compared to exposed group I. In addition, a significant correlation between early lymphocyte apoptosis and exposure time to ADs was also observed (P<0.05). In conclusion, our study identified elevated biomarkers in PIVAS workers exposed to ADs. However whether these findings could lead to increased incidence of genotoxic responses remains to be further investigated. PMID:27179702

  9. Posterior predictive checks to quantify lack-of-fit in admixture models of latent population structure

    PubMed Central

    Mimno, David; Blei, David M.; Engelhardt, Barbara E.

    2015-01-01

    Admixture models are a ubiquitous approach to capture latent population structure in genetic samples. Despite the widespread application of admixture models, little thought has been devoted to the quality of the model fit or the accuracy of the estimates of parameters of interest for a particular study. Here we develop methods for validating admixture models based on posterior predictive checks (PPCs), a Bayesian method for assessing the quality of fit of a statistical model to a specific dataset. We develop PPCs for five population-level statistics of interest: within-population genetic variation, background linkage disequilibrium, number of ancestral populations, between-population genetic variation, and the downstream use of admixture parameters to correct for population structure in association studies. Using PPCs, we evaluate the quality of the admixture model fit to four qualitatively different population genetic datasets: the population reference sample (POPRES) European individuals, the HapMap phase 3 individuals, continental Indians, and African American individuals. We found that the same model fitted to different genomic studies resulted in highly study-specific results when evaluated using PPCs, illustrating the utility of PPCs for model-based analyses in large genomic studies. PMID:26071445

  10. Posterior predictive checks to quantify lack-of-fit in admixture models of latent population structure.

    PubMed

    Mimno, David; Blei, David M; Engelhardt, Barbara E

    2015-06-30

    Admixture models are a ubiquitous approach to capture latent population structure in genetic samples. Despite the widespread application of admixture models, little thought has been devoted to the quality of the model fit or the accuracy of the estimates of parameters of interest for a particular study. Here we develop methods for validating admixture models based on posterior predictive checks (PPCs), a Bayesian method for assessing the quality of fit of a statistical model to a specific dataset. We develop PPCs for five population-level statistics of interest: within-population genetic variation, background linkage disequilibrium, number of ancestral populations, between-population genetic variation, and the downstream use of admixture parameters to correct for population structure in association studies. Using PPCs, we evaluate the quality of the admixture model fit to four qualitatively different population genetic datasets: the population reference sample (POPRES) European individuals, the HapMap phase 3 individuals, continental Indians, and African American individuals. We found that the same model fitted to different genomic studies resulted in highly study-specific results when evaluated using PPCs, illustrating the utility of PPCs for model-based analyses in large genomic studies. PMID:26071445

  11. Genome-wide admixture and association study of serum iron, ferritin, transferrin saturation and total iron binding capacity in African Americans

    PubMed Central

    Li, Jin; Lange, Leslie A.; Duan, Qing; Lu, Yurong; Singleton, Andrew B.; Zonderman, Alan B.; Evans, Michele K.; Li, Yun; Taylor, Herman A.; Willis, Monte S.; Nalls, Mike; Wilson, James G.; Lange, Ethan M.

    2015-01-01

    Iron is an essential component of many important proteins and enzymes, including hemoglobin, which is responsible for carrying oxygen to the cells. African Americans (AAs) have a greater prevalence of iron deficiency compared with European Americans. We conducted genome-wide admixture-mapping and association studies for serum iron, serum ferritin, transferrin saturation (SAT) and total iron binding capacity (TIBC) in 2347 AAs participating in the Jackson Heart Study (JHS). Follow-up replication analyses for JHS iron-trait associated SNPs were conducted in 329 AA participants in the Healthy Aging in Neighborhoods of Diversity across the Life Span study (HANDLS). Higher estimated proportions of global African ancestry were significantly associated with lower levels of iron (P = 2.4 × 10−5), SAT (P = 0.0019) and TIBC (P = 0.042). We observed significant associations (P < 5 × 10−8) between serum TIBC levels and two independent SNPs around TF on chromosome 3, the first report of a genome-wide significant second independent signal in this region, and SNPs near two novel genes: HDGFL1 on chromosome 6 and MAF on chromosome 16. We also observed significant associations between ferritin levels and SNPs near GAB3 on chromosome X. We replicated our two independent associations at TF and our association at GAB3 in HANDLS. Our study provides evidence for both shared and unique genetic risk factors that are associated with iron-related measures in AAs. The top two variants in TF explain 11.2% of the total variation in TIBC levels in AAs after accounting for age, gender, body mass index and background ancestry. PMID:25224454

  12. Development of a Panel of Genome-Wide Ancestry Informative Markers to Study Admixture Throughout the Americas

    PubMed Central

    Galanter, Joshua Mark; Fernandez-Lopez, Juan Carlos; Gignoux, Christopher R.; Barnholtz-Sloan, Jill; Fernandez-Rozadilla, Ceres; Via, Marc; Hidalgo-Miranda, Alfredo; Contreras, Alejandra V.; Figueroa, Laura Uribe; Raska, Paola; Jimenez-Sanchez, Gerardo; Silva Zolezzi, Irma; Torres, Maria; Ponte, Clara Ruiz; Ruiz, Yarimar; Salas, Antonio; Nguyen, Elizabeth; Eng, Celeste; Borjas, Lisbeth; Zabala, William; Barreto, Guillermo; Rondón González, Fernando; Ibarra, Adriana; Taboada, Patricia; Porras, Liliana; Moreno, Fabián; Bigham, Abigail; Gutierrez, Gerardo; Brutsaert, Tom; León-Velarde, Fabiola; Moore, Lorna G.; Vargas, Enrique; Cruz, Miguel; Escobedo, Jorge; Rodriguez-Santana, José; Rodriguez-Cintrón, William; Chapela, Rocio; Ford, Jean G.; Bustamante, Carlos; Seminara, Daniela; Shriver, Mark; Ziv, Elad; Gonzalez Burchard, Esteban; Haile, Robert

    2012-01-01

    Most individuals throughout the Americas are admixed descendants of Native American, European, and African ancestors. Complex historical factors have resulted in varying proportions of ancestral contributions between individuals within and among ethnic groups. We developed a panel of 446 ancestry informative markers (AIMs) optimized to estimate ancestral proportions in individuals and populations throughout Latin America. We used genome-wide data from 953 individuals from diverse African, European, and Native American populations to select AIMs optimized for each of the three main continental populations that form the basis of modern Latin American populations. We selected markers on the basis of locus-specific branch length to be informative, well distributed throughout the genome, capable of being genotyped on widely available commercial platforms, and applicable throughout the Americas by minimizing within-continent heterogeneity. We then validated the panel in samples from four admixed populations by comparing ancestry estimates based on the AIMs panel to estimates based on genome-wide association study (GWAS) data. The panel provided balanced discriminatory power among the three ancestral populations and accurate estimates of individual ancestry proportions (R2>0.9 for ancestral components with significant between-subject variance). Finally, we genotyped samples from 18 populations from Latin America using the AIMs panel and estimated variability in ancestry within and between these populations. This panel and its reference genotype information will be useful resources to explore population history of admixture in Latin America and to correct for the potential effects of population stratification in admixed samples in the region. PMID:22412386

  13. Principal Components Analysis of Population Admixture

    PubMed Central

    Ma, Jianzhong; Amos, Christopher I.

    2012-01-01

    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. PMID:22808102

  14. Sulfate attack on concrete with mineral admixtures

    SciTech Connect

    Irassar, E.F.; Di Maio, A.; Batic, O.R.

    1996-01-01

    The sulfate resistance of concretes containing fly ash, natural pozzolan and slag is investigated in a field test in which concrete specimens were half-buried in sulfate soil for five years. Mineral admixtures were used as a partial replacement for ordinary portland cement (C{sub 3}A = 8.5%), and the progress of sulfate attack was evaluated by several methods (visual rating, loss in mass, dynamic modulus, strength, X-ray analysis). Results of this study show that mineral admixtures improved the sulfate resistance when the concrete is buried in the soil. However, concretes with high content of mineral admixtures exhibit a greater surface scaling over soil level due to the sulfate salt crystallization. In this zone, capillary suction of concrete is the main mechanism of water and salt transportation. Concrete with 20% fly ash provides an integral solution for half-buried structures.

  15. Cartographic mapping study

    NASA Technical Reports Server (NTRS)

    Wilson, C.; Dye, R.; Reed, L.

    1982-01-01

    The errors associated with planimetric mapping of the United States using satellite remote sensing techniques are analyzed. Assumptions concerning the state of the art achievable for satellite mapping systems and platforms in the 1995 time frame are made. An analysis of these performance parameters is made using an interactive cartographic satellite computer model, after first validating the model using LANDSAT 1 through 3 performance parameters. An investigation of current large scale (1:24,000) US National mapping techniques is made. Using the results of this investigation, and current national mapping accuracy standards, the 1995 satellite mapping system is evaluated for its ability to meet US mapping standards for planimetric and topographic mapping at scales of 1:24,000 and smaller.

  16. Air admixture to exhaust jets

    NASA Technical Reports Server (NTRS)

    Sanger, Eugen

    1953-01-01

    The problem of thrust increase by air admixture to exhaust jets of rockets, turbojet, ram- and pulse-jet engines is investigated theoretically. The optimum ratio of mixing chamber pressure to ambient pressure and speed range for thrust increase due to air admixture is determined for each type of jet engine.

  17. Chemical composition, effective atomic number and electron density study of trommel sieve waste (TSW), Portland cement, lime, pointing and their admixtures with TSW in different proportions.

    PubMed

    Kurudirek, Murat; Aygun, Murat; Erzeneoğlu, Salih Zeki

    2010-06-01

    The trommel sieve waste (TSW) which forms during the boron ore production is considered to be a promising building material with its use as an admixture with Portland cement and is considered to be an alternative radiation shielding material, also. Thus, having knowledge on the chemical composition and radiation interaction properties of TSW as compared to other building materials is of importance. In the present study, chemical compositions of the materials used have been determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Also, TSW, some commonly used building materials (Portland cement, lime and pointing) and their admixtures with TSW have been investigated in terms of total mass attenuation coefficients (mu/rho), photon interaction cross sections (sigma(t)), effective atomic numbers (Z(eff)) and effective electron densities (N(e)) by using X-rays at 22.1, 25keV and gamma-rays at 88keV photon energies. Possible conclusions were drawn with respect to the variations in photon energy and chemical composition. PMID:20080413

  18. Survey and coping strategies for job stress of new nurses in pharmacy intravenous admixture service: a pilot study.

    PubMed

    Wang, Feng-Shuang; Jin, Ou; Feng, Hua; Wang, Feng-Hua; Ren, Chun-Hui

    2015-01-01

    To survey the nurse stress and analyze stressors in new nurses from pharmacy intravenous admixture service (PIAS). A questionnaire survey referring to the revised stressor scale was carried out on 52 new nurses of PIAS in four hospitals in Harbin. The average stress score for all participants was 2.43±0.63, as medium level of stress. The stressors were classified into 6 categories: ensuring up-to-date knowledge of professional nursing skills, increased workload and work-time, interpersonal relationship, ensuring knowledge of equipments, attending educational programs, and decreased occupational demand. The most important stressors included fear of medical accident occurrence, fear of failure in performance assessment, fear of occupational injuries, feeling fatigue and lack of sleep. Considering the various kinds of stressors in the working places, it was necessary for managers' to use appropriate strategies to cope with the job stress in new nurses of PIAS. PMID:26770583

  19. Survey and coping strategies for job stress of new nurses in pharmacy intravenous admixture service: a pilot study

    PubMed Central

    Wang, Feng-Shuang; Jin, Ou; Feng, Hua; Wang, Feng-Hua; Ren, Chun-Hui

    2015-01-01

    To survey the nurse stress and analyze stressors in new nurses from pharmacy intravenous admixture service (PIAS). A questionnaire survey referring to the revised stressor scale was carried out on 52 new nurses of PIAS in four hospitals in Harbin. The average stress score for all participants was 2.43±0.63, as medium level of stress. The stressors were classified into 6 categories: ensuring up-to-date knowledge of professional nursing skills, increased workload and work-time, interpersonal relationship, ensuring knowledge of equipments, attending educational programs, and decreased occupational demand. The most important stressors included fear of medical accident occurrence, fear of failure in performance assessment, fear of occupational injuries, feeling fatigue and lack of sleep. Considering the various kinds of stressors in the working places, it was necessary for managers’ to use appropriate strategies to cope with the job stress in new nurses of PIAS. PMID:26770583

  20. The role of racial genetic admixture with endometrial cancer outcomes: An NRG Oncology/Gynecologic Oncology Group study

    PubMed Central

    Rocconi, Rodney P.; Lankes, Heather A.; Brady, William E.; Goodfellow, Paul J.; Ramirez, Nilsa C.; Alvarez, Ronald D.; Creasman, William; Fernández, José R.

    2016-01-01

    Purpose Racial genetic admixture (RGA), a measure to account for ancestral genetic background that correlates with individual's racial classification, could provide insights on causation of racial disparity in endometrial cancer (EC). Our objective is to evaluate the association of RGA with EC outcomes. Methods EC patients enrolled onto the GOG-210 protocol were eligible. A randomized subcohort stratified by stage and self-reported race/ethnicity of black or white was used. Genotyping was performed using custom-selected Ancestry Informative Markers to calculate individual admixture estimates of African and European ancestral background. Results A total of 149 patients were evaluated (self-reported race: 70 black & 79 white). Mean RGA for African ancestry for self-reported black patients was 0.65 (range 0.04–0.86); while mean RGA for European ancestry for self-reported white patients was 0.77 (range 0.12–0.88). Progression-free survival (PFS) analysis using proportional hazards models stratified by stage and race revealed that each 0.10 increase in African ancestry was associated with worse PFS with hazard ratio (HR) of 1.11 (95% CI 0.90–1.37). Each 0.10 increase in European RGA was associated with improved PFS with HR of 0.86 (95% CI 0.69–1.07). Using tertiles of African RGA showed increasing risk of progression of death with increasing African RGA (with 0–5% as reference), HR (95% CIs) for top two tertiles are: 6%–66%: 1.38 (0.64, 2.97), and 67%–86%: 2.27 (0.74, 6.95). Conclusion RGA demonstrated a trend with PFS in self-reported black and white patients with EC. Patients with increased levels of African ancestry showed a trend towards worse survival after stratifying by stage/race. PMID:26603970

  1. Estimating venous admixture using a physiological simulator.

    PubMed

    Hardman, J G; Bedforth, N M

    1999-03-01

    Estimation of venous admixture in patients with impaired gas exchange allows monitoring of disease progression, efficacy of interventions and assessment of the optimal inspired oxygen fraction. A pulmonary artery catheter allows accurate measurement, although the associated risks preclude its use solely for estimation of venous admixture. Non-invasive methods require assumed values for physiological variables. Many of the required data (e.g. haemoglobin concentration (Hb), base excess, inspired oxygen fraction, arterial oxygen (PaO2) and carbon dioxide (PaCO2) tensions, temperature) are available routinely in the intensive therapy unit. We have compared a typical iso-shunt-style estimation of venous admixture (assuming Hb, base excess, PaCO2 and temperature), and estimation using the Nottingham physiology simulator (NPS), with measured data. When the arteriovenous oxygen content difference (CaO2-CvO2) was assumed to be 50 ml litre-1, the 95% limits of agreement (LA95%) for venous admixture using the NPS were -3.9 +/- 8.5% and using an iso-shunt-style calculation, -6.4 +/- 10.6%. CaO2-CvO2 was 41.1 ml litre-1 in the patients studied, consistent with previous studies in the critically ill. When CaO2-CvO2 was assumed to be 40 ml litre-1, LA95% values were 0.5 +/- 8.2% and -2.1 +/- 10.1%, respectively. PMID:10434813

  2. Polymorphic Admixture Typing in Human Ethnic Populations

    PubMed Central

    Dean, Michael; Stephens, J. Claiborne; Winkler, Cheryl; Lomb, Deborah A.; Ramsburg, Mark; Boaze, Raleigh; Stewart, Claudia; Charbonneau, Lauren; Goldman, David; Albaugh, Bernard J.; Goedert, James J.; Beasley, R. Palmer; Hwang, Lu-Yu; Buchbinder, Susan; Weedon, Michael; Johnson, Patricia A.; Eichelberger, Mary; O'Brien, Stephen J.

    1994-01-01

    A panel of 257 RFLP loci was selected on the basis of high heterozygosity in Caucasian DNA surveys and equivalent spacing throughout the human genome. Probes from each locus were used in a Southern blot survey of allele frequency distribution for four human ethnic groups: Caucasian, African American, Asian (Chinese), and American Indian (Cheyenne). Nearly all RFLP loci were polymorphic in each group, albeit with a broad range of differing allele frequencies (δ). The distribution of frequency differences (δ values) was used for three purposes: (1) to provide estimates for genetic distance (differentiation) among these ethnic groups, (2) to revisit with a large data set the proportion of human genetic variation attributable to differentiation within ethnic groups, and (3) to identify loci with high δ values between recently admixed populations of use in mapping by admixture linkage disequilibrium (MALD). Although most markers display significant allele frequency differences between ethnic groups, the overall genetic distances between ethnic groups were small (.066–.098), and <10% of the measured overall molecular genetic diversity in these human samples can be attributed to “racial” differentiation. The median δ values for pairwise comparisons between groups fell between .15 and .20, permitting identification of highly informative RFLP loci for MALD disease association studies. PMID:7942857

  3. Map Study Committee. Final Report.

    ERIC Educational Resources Information Center

    Heidlage, Bob; And Others

    A study undertaken to evaluate the status of the University of Missouri-Columbia's map collections is described in this report, and forecasts are made for necessary facilities, equipment, and personnel to accomplish a proposed reorganization and online cataloging of the university's geology and geography map collections. Included in plans for…

  4. Estimation of race admixture--a new method.

    PubMed

    Chakraborty, R

    1975-05-01

    The contribution of a parental population in the gene pool of a hybrid population which arose by hybridization with one or more other populations is estimated here at the population level from the probability of gene identity. The dynamics of accumulation of such admixture is studied incorporating the fluctuations due to finite size of the hybrid population. The method is illustrated with data on admixture in Cherokee Indians. PMID:1146991

  5. Sagittal Abdominal Diameter as a Surrogate Marker of Insulin Resistance in an Admixtured Population—Brazilian Metabolic Syndrome Study (BRAMS)

    PubMed Central

    Cassani, Roberta S. L.; Forti, Adriana C. e; Vilela, Brunna S.; Tambascia, Marcos Antonio

    2015-01-01

    Background Sagittal abdominal diameter (SAD) has been proposed as a surrogate marker of insulin resistance (IR). However, the utilization of SAD requires specific validation for each ethnicity. We aimed to investigate the potential use of SAD, compared with classical anthropometrical parameters, as a surrogate marker of IR and to establish the cutoff values of SAD for screening for IR. Methods A multicenter population survey on metabolic disorders was conducted. A race-admixtured sample of 824 adult women was assessed. The anthropometric parameters included: BMI, waist circumference (WC), waist-to-hip ratio and SAD. IR was determined by a hyperglycemic clamp and the HOMA-IR index. Results After adjustments for age and total body fat mass, SAD (r = 0.23 and r = -0.70) and BMI (r = 0.20 and r = -0.71) were strongly correlated with the IR measured by the HOMA-IR index and the clamp, respectively (p < 0.001). In the ROC analysis, the optimal cutoff for SAD in women was 21.0 cm. The women with an increased SAD presented 3.2 (CI 95%: 2.1-5.0) more likelihood of having IR, assessed by the HOMA-IR index compared with those with normal SAD (p < 0.001); whereas women with elevated BMI and WC were 2.1 (95% CI: 1.4-3.3) and 2.8 (95% CI: 1.7-4.5) more likely to have IR (p < 0.001), respectively. No statistically significant results were found for waist-to-hip ratio. Conclusions SAD can be a suitable surrogate marker of IR. Understanding and applying routine and simplified methods is essential because IR is associated with an increased risk of obesity-related diseases even in the presence of normal weight, slight overweight, as well as in obesity. Further prospective analysis will need to verify SAD as a determinant of clinical outcomes, such as type 2 diabetes and cardiovascular events, in the Brazilian population. PMID:25951458

  6. Maps and Map Learning in Social Studies

    ERIC Educational Resources Information Center

    Bednarz, Sarah Witham; Acheson, Gillian; Bednarz, Robert S.

    2006-01-01

    The importance of maps and other graphic representations has become more important to geography and geographers. This is due to the development and widespread diffusion of geographic (spatial) technologies. As computers and silicon chips have become more capable and less expensive, geographic information systems (GIS), global positioning satellite…

  7. A Spatial Framework for Understanding Population Structure and Admixture.

    PubMed

    Bradburd, Gideon S; Ralph, Peter L; Coop, Graham M

    2016-01-01

    Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We use genome-wide polymorphism data to build "geogenetic maps," which, when applied to stationary populations, produces a map of the geographic positions of the populations, but with distances distorted to reflect historical rates of gene flow. In the underlying model, allele frequency covariance is a decreasing function of geogenetic distance, and nonlocal gene flow such as admixture can be identified as anomalously strong covariance over long distances. This admixture is explicitly co-estimated and depicted as arrows, from the source of admixture to the recipient, on the geogenetic map. We demonstrate the utility of this method on a circum-Tibetan sampling of the greenish warbler (Phylloscopus trochiloides), in which we find evidence for gene flow between the adjacent, terminal populations of the ring species. We also analyze a global sampling of human populations, for which we largely recover the geography of the sampling, with support for significant histories of admixture in many samples. This new tool for understanding and visualizing patterns of population structure is implemented in a Bayesian framework in the program SpaceMix. PMID:26771578

  8. A Spatial Framework for Understanding Population Structure and Admixture

    PubMed Central

    Bradburd, Gideon S.; Ralph, Peter L.; Coop, Graham M.

    2016-01-01

    Geographic patterns of genetic variation within modern populations, produced by complex histories of migration, can be difficult to infer and visually summarize. A general consequence of geographically limited dispersal is that samples from nearby locations tend to be more closely related than samples from distant locations, and so genetic covariance often recapitulates geographic proximity. We use genome-wide polymorphism data to build “geogenetic maps,” which, when applied to stationary populations, produces a map of the geographic positions of the populations, but with distances distorted to reflect historical rates of gene flow. In the underlying model, allele frequency covariance is a decreasing function of geogenetic distance, and nonlocal gene flow such as admixture can be identified as anomalously strong covariance over long distances. This admixture is explicitly co-estimated and depicted as arrows, from the source of admixture to the recipient, on the geogenetic map. We demonstrate the utility of this method on a circum-Tibetan sampling of the greenish warbler (Phylloscopus trochiloides), in which we find evidence for gene flow between the adjacent, terminal populations of the ring species. We also analyze a global sampling of human populations, for which we largely recover the geography of the sampling, with support for significant histories of admixture in many samples. This new tool for understanding and visualizing patterns of population structure is implemented in a Bayesian framework in the program SpaceMix. PMID:26771578

  9. pH-stabilization of predegraded PDLLA by an admixture of water-soluble sodiumhydrogenphosphate--results of an in vitro- and in vivo-study.

    PubMed

    Heidemann, Wolfgang; Jeschkeit-Schubbert, Stephanie; Ruffieux, Kurt; Fischer, Jürgen Hartmut; Jung, Hedda; Krueger, Gerhard; Wintermantel, Erich; Gerlach, Klaus Louis

    2002-09-01

    Aim of the study was to examine if the addition of buffering sodiumhydrogenphosphate to poly(D,L)lactide(PDLLA) would stabilize the pH-value in the in vivo environment of implanted material and whether this improves its biocompatibility. The material was predegraded just to the point of viscous disintegration to test the PDLLA in the moment of its most aggressive effect on the surrounding tissue. Racemic amorphous PDLLA was injection-molded with or without the admixture of 1 mol NaP per 100 mol lactate, the degradation product of PDLLA (=1 mol%) to form 20mm x 3 mm x 2mm rods. Predegradation was performed by storing the rods at 55 degrees C for 14 days, just to the point of beginning dissolution. Predegraded PDLLA or PDLLA + NaP samples were used for in vitro incubation tests, as well as for the in vivo study, where the rods were implanted into the spinal muscles of 30 male Wistar rats. Repeatedly, measurements of the pH-value were made in the incubation solutions in vitro. The surrounding tissue of the implanted samples as well as the normal contralateral muscle tissue was checked for its pH-value in a group of 3 rats, respectively, anaesthesized at various time intervals after implantation. After these measurements the implants and their surrounding tissues were excised for histological examination. In Ringer's solution pH-values dropped immediately within the first week of incubation of both predegraded materials reaching -4 pH units after 4 weeks in the PDLLA containing medium, after 6 weeks in the PDLLA + NaP containing medium. Soerensen buffer slowed the pH decrease with significant differences between the material groups up to the 28th week. In vivo, the pH of the surrounding tissue was influenced by the implanted PDLLA material up to the 4th week, while the admixture of NaP resulted in a significant pH stabilization. A higher quantity of macrophages and giant cells were seen between the 2nd and 6th week after the implantation in the environment of pure

  10. Experimental and numerical study on the dynamics of a μs helium plasma gun discharge with various amounts of N2 admixture

    NASA Astrophysics Data System (ADS)

    Bourdon, Anne; Darny, Thibault; Robert, Eric; Pechereau, Francois; Viegas, Pedro; Pouvesle, Jean-Michel

    2015-09-01

    These last years, atmospheric pressure plasma jets formed by pulsed helium discharges ignited in thin dielectric tubes have been extensively studied due to their potential for biomedical applications. So far, most experiments have been dedicated to the study of the plasma plume. For endoscopic treatments, it is also important to better understand and optimize the propagation of discharges in long dielectric tubes as catheters. First we present an experimental and numerical study on the dynamics of a μs helium plasma discharge with N2 admixture in a long dielectric tube. We compare the velocity of the discharge front for various amounts of N2 and different applied voltages and show a good agreement between experiments and simulations. Second, we compare time-resolved measurements and simulations of longitudinal and radial electric fields associated with plasma propagation in the dielectric tube and in the plasma plume. It is interesting to note that measurements obtained with a probe located outside the dielectric tube are in excellent agreement with simulations. This allows to infer from simulations the time evolution of the electric field on the discharge axis which is a key parameter for applications. The authors acknowledge the computational resources of the Mesocentre of Ecole Centrale Paris.

  11. EOS mapping accuracy study

    NASA Technical Reports Server (NTRS)

    Forrest, R. B.; Eppes, T. A.; Ouellette, R. J.

    1973-01-01

    Studies were performed to evaluate various image positioning methods for possible use in the earth observatory satellite (EOS) program and other earth resource imaging satellite programs. The primary goal is the generation of geometrically corrected and registered images, positioned with respect to the earth's surface. The EOS sensors which were considered were the thematic mapper, the return beam vidicon camera, and the high resolution pointable imager. The image positioning methods evaluated consisted of various combinations of satellite data and ground control points. It was concluded that EOS attitude control system design must be considered as a part of the image positioning problem for EOS, along with image sensor design and ground image processing system design. Study results show that, with suitable efficiency for ground control point selection and matching activities during data processing, extensive reliance should be placed on use of ground control points for positioning the images obtained from EOS and similar programs.

  12. Lightning mapping sensor study

    NASA Technical Reports Server (NTRS)

    Norwood, V.

    1983-01-01

    A technology assessment to determine how a world-wide, continuous measurement of lightning could be achieved from a geostationary platform is provided. Various approaches to the detector sensors are presented. It was first determined that any existing detector chips would require some degree of modification in order to meet the lightning mapper sensor requirements. The elements of the system were then analyzed, categorized, and graded for study emphasis. The recommended approach for the lightning mapper sensor is to develop a monolithic array in which each detector cell has circuitry that implements a two-step photon-collecting method for a very high dynamic range with good measurement accuracy. The efficiency of the array is compatible with the use of a conventional refractive optics design having an aperture in the neighborhood of 7 to 10 cm.

  13. Topological Signatures for Population Admixture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Topological Signatures for Population AdmixtureDeniz Yorukoglu1, Filippo Utro1, David Kuhn2, Saugata Basu3 and Laxmi Parida1* Abstract Background: As populations with multi-linear transmission (i.e., mixing of genetic material from two parents, say) evolve over generations, the genetic transmission...

  14. Spatial assessment of Argentinean genetic admixture with geographical information systems.

    PubMed

    Diaz-Lacava, Amalia; Walier, Maja; Penacino, Gustavo; Wienker, Thomas F; Baur, Max P

    2011-08-01

    In recent years there has been much attention to Argentinean population stratification. We were interested in assessing population stratification from a geographical perspective and summarizing it in form of maps. We mapped the genetic admixture of the extant male population in central and northern Argentina on the basis of forensic Y-chromosomal haplotypes. We addressed the question which group of genetically similar individuals is predominant in this area. Haplotypes containing seven Y-chromosomal short tandem repeat polymorphisms (Y-STRs), also known as microsatellites - DYS19, DYS389I, DYS389II, DYS390, DYS391, DYS392, DYS393 - were constructed for 145 individuals, recruited in 10 provinces. 97 distinct haplotypes were clustered into four clusters according to molecular distances. A genetic geostatistical analysis was conducted with the open-source geographical information system GRASS GIS. For each haplotype cluster, the according frequency was spatially interpolated over the total study area. Juxtaposing the interpolation surfaces, we screened point-wisely the maximal frequency as well as the label of the respective cluster. The screening results were combined in one summary map. We repeated this procedure for the second maximal frequencies. The resulting maps subdivide the study area into continuous regions comprising one predominant group of similar haplotypes. The first summary map divides the study area into three regions and the second summary map divides the area into four regions. The results of our analysis indicate that two groups of similar European haplotypes alternatively dominate the largest extension of the Argentinean territory. A third group, including South-American haplotypes, dominates the indigenous northwestern Argentinean area. The last group, including worldwide dispersed haplotypes, preponderates in frequency in second place in central Argentina. Our findings confirm a widespread European paternal ancestry, a substantial Amerindian

  15. Heterogeneity in Genetic Admixture across Different Regions of Argentina

    PubMed Central

    Avena, Sergio; Via, Marc; Ziv, Elad; Pérez-Stable, Eliseo J.; Gignoux, Christopher R.; Dejean, Cristina; Huntsman, Scott; Torres-Mejía, Gabriela; Dutil, Julie; Matta, Jaime L.; Beckman, Kenneth; Burchard, Esteban González; Parolin, María Laura; Goicoechea, Alicia; Acreche, Noemí; Boquet, Mariel; Ríos Part, María Del Carmen; Fernández, Vanesa; Rey, Jorge; Stern, Mariana C.; Carnese, Raúl F.; Fejerman, Laura

    2012-01-01

    The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63–68%), 31% Indigenous American (28–33%) and 4% African (3–4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73–79%; Northeast (NEA) 54%, 95%CI: 49–58%; Northwest (NWA) 33%, 95%CI: 21–41%; South 54%, 95%CI: 49–59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75–86%) versus 68% (95%CI: 58–77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88–94%) compared to 54% (95%CI: 51–57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population. PMID:22506044

  16. Heterogeneity in genetic admixture across different regions of Argentina.

    PubMed

    Avena, Sergio; Via, Marc; Ziv, Elad; Pérez-Stable, Eliseo J; Gignoux, Christopher R; Dejean, Cristina; Huntsman, Scott; Torres-Mejía, Gabriela; Dutil, Julie; Matta, Jaime L; Beckman, Kenneth; Burchard, Esteban González; Parolin, María Laura; Goicoechea, Alicia; Acreche, Noemí; Boquet, Mariel; Ríos Part, María Del Carmen; Fernández, Vanesa; Rey, Jorge; Stern, Mariana C; Carnese, Raúl F; Fejerman, Laura

    2012-01-01

    The population of Argentina is the result of the intermixing between several groups, including Indigenous American, European and African populations. Despite the commonly held idea that the population of Argentina is of mostly European origin, multiple studies have shown that this process of admixture had an impact in the entire Argentine population. In the present study we characterized the distribution of Indigenous American, European and African ancestry among individuals from different regions of Argentina and evaluated the level of discrepancy between self-reported grandparental origin and genetic ancestry estimates. A set of 99 autosomal ancestry informative markers (AIMs) was genotyped in a sample of 441 Argentine individuals to estimate genetic ancestry. We used non-parametric tests to evaluate statistical significance. The average ancestry for the Argentine sample overall was 65% European (95%CI: 63-68%), 31% Indigenous American (28-33%) and 4% African (3-4%). We observed statistically significant differences in European ancestry across Argentine regions [Buenos Aires province (BA) 76%, 95%CI: 73-79%; Northeast (NEA) 54%, 95%CI: 49-58%; Northwest (NWA) 33%, 95%CI: 21-41%; South 54%, 95%CI: 49-59%; p<0.0001] as well as between the capital and immediate suburbs of Buenos Aires city compared to more distant suburbs [80% (95%CI: 75-86%) versus 68% (95%CI: 58-77%), p = 0.01]. European ancestry among individuals that declared all grandparents born in Europe was 91% (95%CI: 88-94%) compared to 54% (95%CI: 51-57%) among those with no European grandparents (p<0.001). Our results demonstrate the range of variation in genetic ancestry among Argentine individuals from different regions in the country, highlighting the importance of taking this variation into account in genetic association and admixture mapping studies in this population. PMID:22506044

  17. Genetic admixture, self-reported ethnicity, self-estimated admixture, and skin pigmentation among Hispanics and Native Americans.

    PubMed

    Klimentidis, Yann C; Miller, Geoffrey F; Shriver, Mark D

    2009-04-01

    The relationship between ethnicity and biology is of interest to anthropologists, biomedical scientists, and historians in understanding how human groups are constructed. Ethnic self-identification in recently admixed groups such as Hispanics, African Americans, and Native Americans (NA) is likely to be complex due to the heterogeneity in individual admixture proportions and social environments within these groups. This study examines the relationships between self-identified ethnicity, self-estimated admixture proportions, skin pigmentation, and genetic marker estimated admixture proportions. These measures were assessed using questionnaires, skin color measurements, and genotyping of a panel of 76 ancestry informative markers, among 170 Hispanics and NAs from New Mexico, a state known for its complex history of interactions between people of NA and European (EU) ancestry. Results reveal that NAs underestimate their degree of EU admixture, and that Hispanics underestimate their degree of NA admixture. Within Hispanics, genetic-marker estimated admixture is better predicted by forehead skin pigmentation than by self-estimated admixture. We also find that Hispanic individuals self-identified as "half-White, half Hispanic" and "Spanish" have lower levels of NA admixture than those self-identified as "Mexican" and "Mexican American." Such results highlight the interplay between culture and biology in how individuals identify and view themselves, and have implications for how ethnicity and disease risk are assessed in a medical setting. PMID:18951390

  18. Turbulent diffusion of chemically reacting gaseous admixtures.

    PubMed

    Elperin, T; Kleeorin, N; Liberman, M; Rogachevskii, I

    2014-11-01

    We study turbulent diffusion of chemically reacting gaseous admixtures in a developed turbulence. In our previous study [Phys. Rev. Lett. 80, 69 (1998)PRLTAO0031-900710.1103/PhysRevLett.80.69] using a path-integral approach for a delta-correlated in a time random velocity field, we demonstrated a strong modification of turbulent transport in fluid flows with chemical reactions or phase transitions. In the present study we use the spectral τ approximation that is valid for large Reynolds and Peclet numbers and show that turbulent diffusion of the reacting species can be strongly depleted by a large factor that is the ratio of turbulent and chemical times (turbulent Damköhler number). We have demonstrated that the derived theoretical dependence of a turbulent diffusion coefficient versus the turbulent Damköhler number is in good agreement with that obtained previously in the numerical modeling of a reactive front propagating in a turbulent flow and described by the Kolmogorov-Petrovskii-Piskunov-Fisher equation. We have found that turbulent cross-effects, e.g., turbulent mutual diffusion of gaseous admixtures and turbulent Dufour effect of the chemically reacting gaseous admixtures, are less sensitive to the values of stoichiometric coefficients. The mechanisms of the turbulent cross-effects differ from the molecular cross-effects known in irreversible thermodynamics. In a fully developed turbulence and at large Peclet numbers the turbulent cross-effects are much larger than the molecular ones. The obtained results are applicable also to heterogeneous phase transitions. PMID:25493875

  19. Ancient Admixture in Human History

    PubMed Central

    Patterson, Nick; Moorjani, Priya; Luo, Yontao; Mallick, Swapan; Rohland, Nadin; Zhan, Yiping; Genschoreck, Teri; Webster, Teresa; Reich, David

    2012-01-01

    Population mixture is an important process in biology. We present a suite of methods for learning about population mixtures, implemented in a software package called ADMIXTOOLS, that support formal tests for whether mixture occurred and make it possible to infer proportions and dates of mixture. We also describe the development of a new single nucleotide polymorphism (SNP) array consisting of 629,433 sites with clearly documented ascertainment that was specifically designed for population genetic analyses and that we genotyped in 934 individuals from 53 diverse populations. To illustrate the methods, we give a number of examples that provide new insights about the history of human admixture. The most striking finding is a clear signal of admixture into northern Europe, with one ancestral population related to present-day Basques and Sardinians and the other related to present-day populations of northeast Asia and the Americas. This likely reflects a history of admixture between Neolithic migrants and the indigenous Mesolithic population of Europe, consistent with recent analyses of ancient bones from Sweden and the sequencing of the genome of the Tyrolean “Iceman.” PMID:22960212

  20. Numerical and experimental study of the dynamics of a μs helium plasma gun discharge with various amounts of N2 admixture

    NASA Astrophysics Data System (ADS)

    Bourdon, Anne; Darny, Thibault; Pechereau, François; Pouvesle, Jean-Michel; Viegas, Pedro; Iséni, Sylvain; Robert, Eric

    2016-06-01

    This paper presents a combined 2D numerical and experimental study of the influence of {{\\text{N}}2} admixture on the dynamics of a He-{{\\text{N}}2} discharge in the 10 cm long dielectric tube of a plasma gun set-up. First, the comparison between experiments and simulations is carried out on the ionization front propagation velocity in the tube. The importance of taking into account a detailed kinetic scheme for the He-{{\\text{N}}2} mixture in the simulations to obtain a good agreement with the experiments is put forward. For the μs driven plasma gun, the two- and three-body Penning reactions occurring in the plasma column behind the ionization front, are shown to play a key role on the discharge dynamics. In the experiments and simulations, the significant influence of the amplitude of the applied voltage on the ionization front propagation velocity is observed. As the amount of {{\\text{N}}2} varies, simulation results show that the ionization front velocity, depends on a complex coupling between the kinetics of the discharge, the photoionization and the 2D structure of the discharge in the tube. Finally, the time evolution of axial and radial components of the electric field measured by an electro-optic probe set outside the tube are compared with simulation results. A good agreement is obtained on both components of the electric field. In the tube, simulations show that the magnitude of the axial electric field on the discharge axis depends weakly on the amount of {{\\text{N}}2} conversely to the magnitude of the off-axis peak electric field. Both, simulations and first measurements in the tube or within the plasma plume show peak electric fields of the order of 45 kV·cm-1.

  1. Crystal growth, structural and thermal studies of amino acids admixtured L-arginine phosphate monohydrate single crystals

    NASA Astrophysics Data System (ADS)

    Anandan, P.; Saravanan, T.; Parthipan, G.; Kumar, R. Mohan; Bhagavannarayana, G.; Ravi, G.; Jayavel, R.

    2011-05-01

    To study the improved characteristics of L-arginine phosphate monohydrate (LAP) crystals, amino acids mixed LAP crystals have been grown by slow cooling method. Amino acids like glycine, L-alanine, and L-valine have been selected for doping. Optical quality bulk crystals have been harvested after a typical growth period of about twenty days. The effect of amino acids in the crystal lattice and molecular vibrational frequencies of various functional groups in the crystals have been studied using X-ray powder diffraction and Fourier Transform infrared (FTIR) analyses respectively. Thermal behavior of the amino acids mixed LAP crystals have been studied from the TG and DTG analyses. High-resolution X-ray diffraction studies have been carried out to find the crystalline nature. Optical transmission studies have been carried out by UV-vis spectrophotometer. The cut off wavelength is below 240 nm for the grown crystals.

  2. Infrared studies of molecular shocks in the supernova remnant HB 21: II. Thermal admixture of shocked H2 gas in the south

    NASA Astrophysics Data System (ADS)

    Shinn, Jong-Ho; Koo, Bon-Chul; Burton, Michael; Lee, Ho-Gyu; Moon, Dae-Sik

    2010-02-01

    We present near- and mid-infrared observations on the shock-cloud interaction region in the southern part of the supernova remnant HB 21, performed with the InfraRed Camera (IRC) aboard AKARI satellite and the Wide InfraRed Camera (WIRC) at the Palomar 5 m telescope. The IRC 4 μm (N4), 7 μm (S7), and 11 μm (S11) band images and the WIRC Hυ=1→0S(1) 2.12 μm image show similar diffuse features, around a shocked CO cloud. We analyzed the emission through comparison with the H2 line emission of several shock models. The IRC colors are well explained by the thermal admixture model of H2 gas - whose infinitesimal H2 column density has a power-law relation with the temperature T, dN˜T-dT - with n(H)˜3.9×104cm-3,b˜4.2, and N(H;T>100K)˜2.8×1021cm-2. We interpreted these parameters with several different pictures of the shock-cloud interactions - multiple planar C-shocks, bow shocks, and shocked clumps - and discussed their weaknesses and strengths. The observed Hυ=1→0S(1) intensity is four times greater than the prediction from the power-law admixture model, the same tendency as found in the northern part of HB 21 (Paper I). We also explored the limitation of the thermal admixture model with respect to the derived model parameters.

  3. Strong selection at MHC in Mexicans since admixture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the major histocompatibility complex (MHC) region Mexicans have excessive African ance...

  4. Worldwide patterns of genomic variation and admixture in gray wolves.

    PubMed

    Fan, Zhenxin; Silva, Pedro; Gronau, Ilan; Wang, Shuoguo; Armero, Aitor Serres; Schweizer, Rena M; Ramirez, Oscar; Pollinger, John; Galaverni, Marco; Ortega Del-Vecchyo, Diego; Du, Lianming; Zhang, Wenping; Zhang, Zhihe; Xing, Jinchuan; Vilà, Carles; Marques-Bonet, Tomas; Godinho, Raquel; Yue, Bisong; Wayne, Robert K

    2016-02-01

    The gray wolf (Canis lupus) is a widely distributed top predator and ancestor of the domestic dog. To address questions about wolf relationships to each other and dogs, we assembled and analyzed a data set of 34 canine genomes. The divergence between New and Old World wolves is the earliest branching event and is followed by the divergence of Old World wolves and dogs, confirming that the dog was domesticated in the Old World. However, no single wolf population is more closely related to dogs, supporting the hypothesis that dogs were derived from an extinct wolf population. All extant wolves have a surprisingly recent common ancestry and experienced a dramatic population decline beginning at least ∼30 thousand years ago (kya). We suggest this crisis was related to the colonization of Eurasia by modern human hunter-gatherers, who competed with wolves for limited prey but also domesticated them, leading to a compensatory population expansion of dogs. We found extensive admixture between dogs and wolves, with up to 25% of Eurasian wolf genomes showing signs of dog ancestry. Dogs have influenced the recent history of wolves through admixture and vice versa, potentially enhancing adaptation. Simple scenarios of dog domestication are confounded by admixture, and studies that do not take admixture into account with specific demographic models are problematic. PMID:26680994

  5. North African Populations Carry the Signature of Admixture with Neandertals

    PubMed Central

    Civit, Sergi; Arenas, Conxita; Ávila-Arcos, María C.; Bustamante, Carlos D.; Comas, David; Lalueza-Fox, Carles

    2012-01-01

    One of the main findings derived from the analysis of the Neandertal genome was the evidence for admixture between Neandertals and non-African modern humans. An alternative scenario is that the ancestral population of non-Africans was closer to Neandertals than to Africans because of ancient population substructure. Thus, the study of North African populations is crucial for testing both hypotheses. We analyzed a total of 780,000 SNPs in 125 individuals representing seven different North African locations and searched for their ancestral/derived state in comparison to different human populations and Neandertals. We found that North African populations have a significant excess of derived alleles shared with Neandertals, when compared to sub-Saharan Africans. This excess is similar to that found in non-African humans, a fact that can be interpreted as a sign of Neandertal admixture. Furthermore, the Neandertal's genetic signal is higher in populations with a local, pre-Neolithic North African ancestry. Therefore, the detected ancient admixture is not due to recent Near Eastern or European migrations. Sub-Saharan populations are the only ones not affected by the admixture event with Neandertals. PMID:23082212

  6. Worldwide patterns of genomic variation and admixture in gray wolves

    PubMed Central

    Fan, Zhenxin; Silva, Pedro; Gronau, Ilan; Wang, Shuoguo; Armero, Aitor Serres; Schweizer, Rena M.; Ramirez, Oscar; Pollinger, John; Galaverni, Marco; Ortega Del-Vecchyo, Diego; Du, Lianming; Zhang, Wenping; Zhang, Zhihe; Xing, Jinchuan; Vilà, Carles; Marques-Bonet, Tomas; Godinho, Raquel; Yue, Bisong; Wayne, Robert K.

    2016-01-01

    The gray wolf (Canis lupus) is a widely distributed top predator and ancestor of the domestic dog. To address questions about wolf relationships to each other and dogs, we assembled and analyzed a data set of 34 canine genomes. The divergence between New and Old World wolves is the earliest branching event and is followed by the divergence of Old World wolves and dogs, confirming that the dog was domesticated in the Old World. However, no single wolf population is more closely related to dogs, supporting the hypothesis that dogs were derived from an extinct wolf population. All extant wolves have a surprisingly recent common ancestry and experienced a dramatic population decline beginning at least ∼30 thousand years ago (kya). We suggest this crisis was related to the colonization of Eurasia by modern human hunter–gatherers, who competed with wolves for limited prey but also domesticated them, leading to a compensatory population expansion of dogs. We found extensive admixture between dogs and wolves, with up to 25% of Eurasian wolf genomes showing signs of dog ancestry. Dogs have influenced the recent history of wolves through admixture and vice versa, potentially enhancing adaptation. Simple scenarios of dog domestication are confounded by admixture, and studies that do not take admixture into account with specific demographic models are problematic. PMID:26680994

  7. Genetic admixture studies on four in situ evolved, two migrant and twenty-one ethnic populations of Tamil Nadu, south India.

    PubMed

    Suhasini, G; Sonaa, E; Shila, S; Srikumari, C R; Jayaraman, G; Ramesh, A

    2011-08-01

    We analysed the genetic structure of ≈ 1000 samples representing 27 ethnic groups settled in Tamil Nadu, south India, derived from two linguistic families (Dravidians and Indo-Europeans) representing four religious groups (Hinduism, Islam, Christianity and Jainism) using 11 mtDNA markers. Out of 27 ethnic groups, four are in situ populations (Anglo-Indian, Labbai Muslim, Nadar Christian and south Indian Jain) and two are migrants (Gypsy and north Indian Jain) from north India to Tamil Nadu, and 21 are native ethnic groups. Six of the markers we used were monomorphic (HaeIII663, HpaI3592, AluI5176, AluI7025, AluI13262, 9-bp deletion) and five markers were polymorphic (DdeI10394, AluI10397, HinfI12308, HincII13259 and HaeIII16517). Haplogroup frequencies, genetic affinities and admixture analysis are based on the genotype data of polymorphic markers observed in these populations. Haplogroup frequencies indicate that various ethnic groups entered Tamil Nadu during different time periods. Genetic affinities and admixture estimates revealed that the ethnic groups possessing advanced knowledge of farming cluster in a branch (C), and could be the late arrived settlers as agriculture, was introduced to this region at about 5 to 3 thousand years ago. In situ ethnic groups appear to have arisen at various times as a result of the prevailing dominant socio-cultural forces. Hierarchical Hindu caste system created many ethnic groups in the history of its existence; some of them became isolated for considerable period of time. Over all, among Tamil ethnic groups, in spite of caste systems' rigidity, built in flexibility in the system in the form of hypergamy and hypogamy had allowed maternal gene flow between them. PMID:21869467

  8. Population admixture may appear to mask, change or reverse genetic effects of genes underlying complex traits.

    PubMed Central

    Deng, H W

    2001-01-01

    Association studies using random population samples are increasingly being applied in the identification and inference of genetic effects of genes underlying complex traits. It is well recognized that population admixture may yield false-positive identification of genetic effects for complex traits. However, it is less well appreciated that population admixture can appear to mask, change, or reverse true genetic effects for genes underlying complex traits. By employing a simple population genetics model, we explore the effects and the conditions of population admixture in masking, changing, or even reversing true genetic effects of genes underlying complex traits. PMID:11729172

  9. Interethnic admixture and the evolution of Latin American populations

    PubMed Central

    Salzano, Francisco Mauro; Sans, Mónica

    2014-01-01

    A general introduction to the origins and history of Latin American populations is followed by a systematic review of the data from molecular autosomal assessments of the ethnic/continental (European, African, Amerindian) ancestries for 24 Latin American countries or territories. The data surveyed are of varying quality but provide a general picture of the present constitution of these populations. A brief discussion about the applications of these results (admixture mapping) is also provided. Latin American populations can be viewed as natural experiments for the investigation of unique anthropological and epidemiological issues. PMID:24764751

  10. Interethnic admixture and the evolution of Latin American populations.

    PubMed

    Salzano, Francisco Mauro; Sans, Mónica

    2014-03-01

    A general introduction to the origins and history of Latin American populations is followed by a systematic review of the data from molecular autosomal assessments of the ethnic/continental (European, African, Amerindian) ancestries for 24 Latin American countries or territories. The data surveyed are of varying quality but provide a general picture of the present constitution of these populations. A brief discussion about the applications of these results (admixture mapping) is also provided. Latin American populations can be viewed as natural experiments for the investigation of unique anthropological and epidemiological issues. PMID:24764751

  11. 21st Century Skills Map: Social Studies

    ERIC Educational Resources Information Center

    Partnership for 21st Century Skills, 2007

    2007-01-01

    This 21st Century Skills Map is the result of hundreds of hours of research, development and feedback from educators and business leaders across the nation. The Partnership for 21st Century Skills has issued this map for the core subject of Social Studies.

  12. The influence of compound admixtures on the properties of high-content slag cement

    SciTech Connect

    Dongxu, L.; Xuequan, W.; Jinlin, S.; Yujiang, W.

    2000-01-01

    Based on the activation theory of alkali and sulfate, the influence of compound admixtures on the properties of high-content slag cement was studied by testing the strength, pore structure, hydrates, and microstructure, Test results show that compound admixtures can obviously improve the properties of high-content slag cement. The emphasis of the present research is two-fold: substituting gypsum with anhydrite and calcining gypsum. These both can improve early and later performance.

  13. Stability of admixture containing morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride in an implantable infusion system.

    PubMed

    Classen, Ashley M; Wimbish, Gary H; Kupiec, Thomas C

    2004-12-01

    Intrathecal infusion is often performed using drug combinations. This study was conducted to evaluate the stability of the admixture of morphine sulfate, bupivacaine hydrochloride, and clonidine hydrochloride when used in an implantable pump under simulated clinical use conditions. SynchroMed implantable pumps were filled with an admixture and incubated at 37 degrees C for a period of 90 days. Drug admixture stored in glass vials at 4 degrees C and at 37 degrees C served as controls. Samples which included pump reservoir and catheter delivered aliquots were collected every 30 days and analyzed for drug concentrations using a stability-indicating HPLC method. All drugs contained in the admixture were stable and the original concentrations remained greater than 96%. Over 90 days, and with the pump at the simulated body temperature of 37 degrees C, there were no evident heat catalyzed or device catalyzed reactions. PMID:15589086

  14. Admixture enhanced controlled low-strength material for direct underwater injection with minimal cross-contamination

    SciTech Connect

    Hepworth, H.K.; Davidson, J.S.; Hooyman, J.L.

    1997-03-01

    Commercially available admixtures have been developed for placing traditional concrete products under water. This paper evaluates adapting anti-washout admixture (AWA) and high range water reducing admixture (HRWRA) products to enhance controlled low-strength materials (CLSMs) for underwater placement. A simple experimental scale model (based on dynamic and geometric similitude) of typical grout pump emplacement equipment has been developed to determine the percentage of cementing material washed out. The objective of this study was to identify proportions of admixtures and underwater CLSM emplacement procedures which would minimize the cross-contamination of the displaced water while maintaining the advantages of CLSM. Since the displaced water from radioactively contaminated systems must be subsequently treated prior to release to the environment, the amount of cross-contamination is important for cases in which cementing material could form hard sludges in a water treatment facility and contaminate the in-place CLSM stabilization medium.

  15. Admixture facilitates genetic adaptations to high altitude in Tibet

    PubMed Central

    Jeong, Choongwon; Alkorta-Aranburu, Gorka; Basnyat, Buddha; Neupane, Maniraj; Witonsky, David B.; Pritchard, Jonathan K.; Beall, Cynthia M.; Di Rienzo, Anna

    2015-01-01

    Admixture is recognized as a widespread feature of human populations, renewing interest in the possibility that genetic exchange can facilitate adaptations to new environments. Studies of Tibetans revealed candidates for high-altitude adaptations in the EGLN1 and EPAS1 genes, associated with lower hemoglobin concentration. However, the history of these variants or that of Tibetans remains poorly understood. Here, we analyze genotype data for the Nepalese Sherpa, and find that Tibetans are a mixture of ancestral populations related to the Sherpa and Han Chinese. EGLN1 and EPAS1 genes show a striking enrichment of high-altitude ancestry in the Tibetan genome, indicating that migrants from low altitude acquired adaptive alleles from the highlanders. Accordingly, the Sherpa and Tibetans share adaptive hemoglobin traits. This admixture-mediated adaptation shares important features with adaptive introgression. Therefore, we identify a novel mechanism, beyond selection on new mutations or on standing variation, through which populations can adapt to local environments. PMID:24513612

  16. Adsorption of superplasticizer admixtures on alkali-activated slag pastes

    SciTech Connect

    Palacios, M. Houst, Y.F.; Bowen, P.; Puertas, F.

    2009-08-15

    Alkali-activated slag (AAS) binders are obtained by a manufacturing process less energy-intensive than ordinary Portland cement (OPC) and involves lower greenhouse gasses emission. These alkaline cements allow the production of high mechanical strength and durable concretes. In the present work, the adsorption of different superplasticizer admixtures (naphthalene-based, melamine-based and a vinyl copolymer) on the slag particles in AAS pastes using alkaline solutions with different pH values have been studied in detail. The effect of the superplasticizers on the yield stress and plastic viscosity of the AAS and OPC pastes have been also evaluated. The results obtained allowed us to conclude that the adsorption of the superplasticizers on AAS pastes is independent of the pH of the alkaline solutions used and lower than on OPC pastes. However, the effect of the admixtures on the rheological parameters depends directly on the type and dosage of the superplasticizer as well as of the binder used and, in the case of the AAS, on the pH of the alkaline activator solution. In 11.7-pH NaOH-AAS pastes the dosages of the superplasticizers required to attain similar reduction in the yield stress are ten-fold lower than for Portland cement. In this case the superplasticizers studied show a fluidizing effect considerably higher in 11.7-pH NaOH-AAS pastes than in OPC pastes. In 13.6-pH NaOH-AAS pastes, the only admixture observed to affect the rheological parameters is the naphthalene-based admixture due to its higher chemical stability in such extremely alkaline media.

  17. Effect of Waterproofing Admixtures on the Flexural Strength and Corrosion Resistance of Concrete

    NASA Astrophysics Data System (ADS)

    Geetha, A.; Perumal, P.

    2012-02-01

    This paper deals about the flexural strength and corrosion behaviour of concrete using waterproofing admixtures. The effect of waterproofing admixtures on the corrosion behaviour of RCC specimen has been studied by conducting accelerated corrosion test. To identify the effect of corrosion in pull out strength, corrosion process was induced by means of accelerated corrosion procedure. To accelerate the reinforcement corrosion, direct electric current was impressed on the rebar embedded in the specimen using a DC power supply system that has a facility to adjust voltage. The addition of waterproofing admixtures also shows the improvement in the flexural strength of concrete has been studied by conducting flexural strength tests on the concrete prism specimen of size 100 × 100 × 500 mm with and without admixtures for various dosages and various curing periods of 7 and 28 days. The results showed that the presence of waterproofing admixtures always improves the corrosion resistance and thus increases the strength of concrete due to the hydrophobic action of waterproofing admixtures.

  18. A Novel Admixture-Based Pharmacogenetic Approach to Refine Warfarin Dosing in Caribbean Hispanics

    PubMed Central

    Claudio-Campos, Karla; Rivera-Miranda, Giselle; Bermúdez-Bosch, Luis; Renta, Jessicca Y.; Cadilla, Carmen L.; Cruz, Iadelisse; Feliu, Juan F.; Vergara, Cunegundo; Ruaño, Gualberto

    2016-01-01

    Aim This study is aimed at developing a novel admixture-adjusted pharmacogenomic approach to individually refine warfarin dosing in Caribbean Hispanic patients. Patients & Methods A multiple linear regression analysis of effective warfarin doses versus relevant genotypes, admixture, clinical and demographic factors was performed in 255 patients and further validated externally in another cohort of 55 individuals. Results The admixture-adjusted, genotype-guided warfarin dosing refinement algorithm developed in Caribbean Hispanics showed better predictability (R2 = 0.70, MAE = 0.72mg/day) than a clinical algorithm that excluded genotypes and admixture (R2 = 0.60, MAE = 0.99mg/day), and outperformed two prior pharmacogenetic algorithms in predicting effective dose in this population. For patients at the highest risk of adverse events, 45.5% of the dose predictions using the developed pharmacogenetic model resulted in ideal dose as compared with only 29% when using the clinical non-genetic algorithm (p<0.001). The admixture-driven pharmacogenetic algorithm predicted 58% of warfarin dose variance when externally validated in 55 individuals from an independent validation cohort (MAE = 0.89 mg/day, 24% mean bias). Conclusions Results supported our rationale to incorporate individual’s genotypes and unique admixture metrics into pharmacogenetic refinement models in order to increase predictability when expanding them to admixed populations like Caribbean Hispanics. Trial Registration ClinicalTrials.gov NCT01318057 PMID:26745506

  19. Population divergence with or without admixture: selecting models using an ABC approach

    PubMed Central

    Sousa, V C; Beaumont, M A; Fernandes, P; Coelho, M M; Chikhi, L

    2012-01-01

    Genetic data have been widely used to reconstruct the demographic history of populations, including the estimation of migration rates, divergence times and relative admixture contribution from different populations. Recently, increasing interest has been given to the ability of genetic data to distinguish alternative models. One of the issues that has plagued this kind of inference is that ancestral shared polymorphism is often difficult to separate from admixture or gene flow. Here, we applied an approximate Bayesian computation (ABC) approach to select the model that best fits microsatellite data among alternative splitting and admixture models. We performed a simulation study and showed that with reasonably large data sets (20 loci) it is possible to identify with a high level of accuracy the model that generated the data. This suggests that it is possible to distinguish genetic patterns due to past admixture events from those due to shared polymorphism (population split without admixture). We then apply this approach to microsatellite data from an endangered and endemic Iberian freshwater fish species, in which a clustering analysis suggested that one of the populations could be admixed. In contrast, our results suggest that the observed genetic patterns are better explained by a population split model without admixture. PMID:22146980

  20. Beyond 2/3 and 1/3: The Complex Signatures of Sex-Biased Admixture on the X Chromosome

    PubMed Central

    Goldberg, Amy; Rosenberg, Noah A.

    2015-01-01

    Sex-biased demography, in which parameters governing migration and population size differ between females and males, has been studied through comparisons of X chromosomes, which are inherited sex-specifically, and autosomes, which are not. A common form of sex bias in humans is sex-biased admixture, in which at least one of the source populations differs in its proportions of females and males contributing to an admixed population. Studies of sex-biased admixture often examine the mean ancestry for markers on the X chromosome in relation to the autosomes. A simple framework noting that in a population with equally many females and males, two-thirds of X chromosomes appear in females, suggests that the mean X-chromosomal admixture fraction is a linear combination of female and male admixture parameters, with coefficients 2/3 and 1/3, respectively. Extending a mechanistic admixture model to accommodate the X chromosome, we demonstrate that this prediction is not generally true in admixture models, although it holds in the limit for an admixture process occurring as a single event. For a model with constant ongoing admixture, we determine the mean X-chromosomal admixture, comparing admixture on female and male X chromosomes to corresponding autosomal values. Surprisingly, in reanalyzing African-American genetic data to estimate sex-specific contributions from African and European sources, we find that the range of contributions compatible with the excess African ancestry on the X chromosome compared to autosomes has a wide spread, permitting scenarios either without male-biased contributions from Europe or without female-biased contributions from Africa. PMID:26209245

  1. Stability of total nutrient admixtures in a dual-chamber flexible container.

    PubMed

    Tripp, M G; Menon, S K; Mikrut, B A

    1990-11-01

    The stability of total nutrient admixtures (TNAs) prepared from dextrose and amino acid injections commercially packaged in a dual-chamber container and a safflower-soybean oil fat emulsion was studied. The admixtures studied were divided into two groups. Group 1 admixtures represented 14 combinations of Aminosyn II, dextrose, and Liposyn II. Group 2 admixtures represented 10 combinations of Aminosyn II with Electrolytes, dextrose, and Liposyn II. Amino acid concentrations of 7, 8.5, and 10%, dextrose concentrations of 10, 20, 40, and 50%, and 10 and 20% fat emulsion were used. After the amino acid and dextrose injections were mixed in their original container (Nutrimix, Abbott Laboratories), the fat emulsion was added. One of two combinations of electrolytes and trace metals was then added. Multivitamins were added to each TNA just before 24-hour storage at room temperature (25 +/- 4 degrees C). Admixtures were tested initially and at the conclusion of storage periods of 24 hours at room temperature or nine days at 5 degrees C followed by 24 hours at room temperature. Measurements of pH, emulsion particle size, and weight percent of oil particles larger than 5 microns in diameter (HIAC) were made after visual inspection of each admixture. In selected admixtures, concentrations of individual amino acids and dextrose were determined by chromatographic techniques initially and at the conclusion of storage. The TNAs retained a uniform milk-like appearance throughout both storage periods. The pH values, particle size, HIAC measurements, and amino acid and dextrose concentrations remained essentially unchanged.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2126163

  2. The relationship between European genetic admixture and body composition among Hispanics and Native Americans.

    PubMed

    Klimentidis, Y C; Miller, G F; Shriver, M D

    2009-01-01

    Previous studies have shown a relationship between health-related phenotypes and the degree of African, European, or Native American genetic admixture, indicating that there may be a genetic component to these phenotypes. However, these relationships may be driven to a large extent by the environmental differences that co-vary with admixture differences between and within groups. In this study, we examine the relationship between genetic admixture and two phenotypic measurements that are potentially related to health: body mass index (BMI) and percent body fat (PBF). In addition to admixture proportions, we attempt to assess the influence of some environmental covariates by examining how the phenotypes vary with self-reported household income, education of parents, and physical activity level. Genetic, anthropometric, and environmental data were collected from 170 self-reported Hispanic and Native American university students in Albuquerque, NM. We examine the relationships between genetic admixture, phenotype, and environment in both the full sample, as well as in Hispanics and Native Americans separately. Among Hispanics, we find no significant relationship between genetic admixture and body composition. Among Native Americans, despite a small sample size, we find a statistically significant, negative relationship between European genetic admixture and PBF and BMI, after adjusting for other predictor variables. We compare our findings to previous research, and discuss their implications for understanding health disparities within and between ethnic groups. PMID:19214998

  3. Effect of high doses of chemical admixtures on the strength development and freeze-thaw durability of portland cement mortar

    NASA Astrophysics Data System (ADS)

    Korhonen, Charles J.

    This thesis examines the low-temperature strength development of portland cement concrete made with high doses of chemical admixtures dissolved in the mixing water and the possible beneficial effect of these admixtures on that concrete's long-term freeze-thaw durability. The literature shows that high doses of chemical admixtures can protect fresh concrete against freezing and that, under certain conditions, these admixtures can enhance the freeze-thaw durability of concrete. The challenge is that there are no acceptance standards in the U.S. that allow chemicals to be used to protect concrete against freezing. Also, the perception is that chemicals might somehow harm the concrete. This perception seems to be based on the fact that deicing salts, when applied to concrete pavement, cause roadways to scale away. This study investigated the effect of high doses of commercially available admixtures on fresh concrete while it gained strength at low temperature and on hardened concrete exposed to repeated cycles of freezing and thawing in a moist environment. The reason for studying off-the-shelf admixtures was that these materials are approved for use in concrete; they were already governed by their own set of standards. Four mortars were examined, each with a different cement and water content, when dosed with five commercial admixtures. This allowed the fresh mortar to gain appreciable strength when it was kept at nearly -10C. The admixtures also enhanced the freeze-thaw durability of the mortar, even when it was not air-entrained. Clearly, as the dosage of admixture increased beyond approximately 22% by weight of water, the mortar appeared to be unaffected by up to 700 cycles of freezing and thawing.

  4. Assessment of coyote-wolf-dog admixture using ancestry-informative diagnostic SNPs.

    PubMed

    Monzón, J; Kays, R; Dykhuizen, D E

    2014-01-01

    The evolutionary importance of hybridization as a source of new adaptive genetic variation is rapidly gaining recognition. Hybridization between coyotes and wolves may have introduced adaptive alleles into the coyote gene pool that facilitated an expansion in their geographic range and dietary niche. Furthermore, hybridization between coyotes and domestic dogs may facilitate adaptation to human-dominated environments. We genotyped 63 ancestry-informative single-nucleotide polymorphisms in 427 canids to examine the prevalence, spatial distribution and the ecology of admixture in eastern coyotes. Using multivariate methods and Bayesian clustering analyses, we estimated the relative contributions of western coyotes, western and eastern wolves, and domestic dogs to the admixed ancestry of Ohio and eastern coyotes. We found that eastern coyotes form an extensive hybrid swarm, with all our samples having varying levels of admixture. Ohio coyotes, previously thought to be free of admixture, are also highly admixed with wolves and dogs. Coyotes in areas of high deer density are genetically more wolf-like, suggesting that natural selection for wolf-like traits may result in local adaptation at a fine geographic scale. Our results, in light of other previously published studies of admixture in Canis, revealed a pattern of sex-biased hybridization, presumably generated by male wolves and dogs mating with female coyotes. This study is the most comprehensive genetic survey of admixture in eastern coyotes and demonstrates that the frequency and scope of hybridization can be quantified with relatively few ancestry-informative markers. PMID:24148003

  5. Assessment of coyote-wolf-dog admixture using ancestry-informative diagnostic SNPs

    PubMed Central

    Monzón, J.; Kays, R.; Dykhuizen, D. E.

    2014-01-01

    The evolutionary importance of hybridization as a source of new adaptive genetic variation is rapidly gaining recognition. Hybridization between coyotes and wolves may have introduced adaptive alleles into the coyote gene pool that facilitated an expansion in their geographic range and dietary niche. Furthermore, hybridization between coyotes and domestic dogs may facilitate adaptation to human-dominated environments. We genotyped 63 ancestry-informative single nucleotide polymorphisms in 427 canids in order to examine the prevalence, spatial distribution, and ecology of admixture in eastern coyotes. Using multivariate methods and Bayesian clustering analyses, we estimated the relative contributions of western coyotes, western and eastern wolves, and domestic dogs to the admixed ancestry of Ohio and eastern coyotes. We found that eastern coyotes form an extensive hybrid swarm, with all our samples having varying levels of admixture. Ohio coyotes, previously thought to be free of admixture, are also highly admixed with wolves and dogs. Coyotes in areas of high deer density are genetically more wolf-like, suggesting that natural selection for wolf-like traits may result in local adaptation at a fine geographic scale. Our results, in light of other previously published studies of admixture in Canis, reveal a pattern of sex-biased hybridization, presumably generated by male wolves and dogs mating with female coyotes. This study is the most comprehensive genetic survey of admixture in eastern coyotes and demonstrates that the frequency and scope of hybridization can be quantified with relatively few ancestry-informative markers. PMID:24148003

  6. Admixture increases diversity in managed honey bees: reply to De la Rúa et al. (2013).

    PubMed

    Harpur, Brock A; Minaei, Shermineh; Kent, Clement F; Zayed, Amro

    2013-06-01

    De la Rúa et al. (2013) express some concerns about the conclusions of our recent study showing that management increases genetic diversity of honey bees (Apis mellifera) by promoting admixture (Harpur et al. 2012). We provide a brief review of the literature on the population genetics of A. mellifera and show that we utilized appropriate sampling methods to estimate genetic diversity in the focal populations. Our finding of higher genetic diversity in two managed A. mellifera populations on two different continents is expected to be the norm given the large number of studies documenting admixture in honey bees. Our study focused on elucidating how management affects genetic diversity in honey bees, not on how to best manage bee colonies. We do not endorse the intentional admixture of honey bee populations, and we agree with De la Rúa et al. (2013) that native honey bee subspecies should be conserved. PMID:24433573

  7. A deterministic model of admixture and genetic introgression: the case of Neanderthal and Cro-Magnon.

    PubMed

    Forhan, Gerald; Martiel, Jean-Louis; Blum, Michael G B

    2008-11-01

    There is an ongoing debate in the field of human evolution about the possible contribution of Neanderthals to the modern human gene pool. To study how the Neanderthal private alleles may have spread over the genes of Homo sapiens, we propose a deterministic model based on recursive equations and ordinary differential equations. If the Neanderthal population was large compared to the Homo sapiens population at the beginning of the contact period, we show that genetic introgression should have been fast and complete meaning that most of the Neanderthal private alleles should be found in the modern human gene pool in case of ancient admixture. In order to test/reject ancient admixture from genome-wide data, we incorporate the model of genetic introgression into a statistical hypothesis-testing framework. We show that the power to reject ancient admixture increases as the ratio, at the time of putative admixture, of the population size of Homo sapiens over that of Neanderthal decreases. We find that the power to reject ancient admixture might be particularly low if the population size of Homo sapiens was comparable to the Neanderthal population size. PMID:18768141

  8. African and non-African admixture components in African Americans and an African Caribbean population.

    PubMed

    Murray, Tanda; Beaty, Terri H; Mathias, Rasika A; Rafaels, Nicholas; Grant, Audrey Virginia; Faruque, Mezbah U; Watson, Harold R; Ruczinski, Ingo; Dunston, Georgia M; Barnes, Kathleen C

    2010-09-01

    Admixture is a potential source of confounding in genetic association studies, so it becomes important to detect and estimate admixture in a sample of unrelated individuals. Populations of African descent in the US and the Caribbean share similar historical backgrounds but the distributions of African admixture may differ. We selected 416 ancestry informative markers (AIMs) to estimate and compare admixture proportions using STRUCTURE in 906 unrelated African Americans (AAs) and 294 Barbadians (ACs) from a study of asthma. This analysis showed AAs on average were 72.5% African, 19.6% European and 8% Asian, while ACs were 77.4% African, 15.9% European, and 6.7% Asian which were significantly different. A principal components analysis based on these AIMs yielded one primary eigenvector that explained 54.04% of the variation and captured a gradient from West African to European admixture. This principal component was highly correlated with African vs. European ancestry as estimated by STRUCTURE (r(2)=0.992, r(2)=0.912, respectively). To investigate other African contributions to African American and Barbadian admixture, we performed PCA on approximately 14,000 (14k) genome-wide SNPs in AAs, ACs, Yorubans, Luhya and Maasai African groups, and estimated genetic distances (F(ST)). We found AAs and ACs were closest genetically (F(ST)=0.008), and both were closer to the Yorubans than the other East African populations. In our sample of individuals of African descent, approximately 400 well-defined AIMs were just as good for detecting substructure as approximately 14,000 random SNPs drawn from a genome-wide panel of markers. PMID:20717976

  9. New advanced shotcrete admixtures: Internal curing

    SciTech Connect

    Melbye, T.A.

    1995-12-31

    Tunnels and other underground construction projects have one of the worst curing conditions due to the ventilation that blows continuously dry (cold or hot) air into the tunnel. It can be compared with concrete exposed to a windy area. One would think that tunnels have ideal curing conditions with high humidity (water leakage), no wind and no sun exposure. However, this is not the case. MBT has developed a new system for more efficient and secure curing of wet shotcrete, repair mortars as well as concrete. Internal curing means that a special admixture is added to the concrete/mortar during batching as a normal admixture. This admixture produces an internal barrier in the shotcrete/concrete which secures safer hydration and better chemical resistance than the application of conventional curing agents. The benefits resulting from the new technology are impressive: The time consuming application and, in the case of various shotcrete layers, removal of curing agents are no longer necessary; curing is guaranteed from the very beginning of hydration; and there is no negative influence on bonding between layers. As a consequence of th is optimum curing effect, all other shotcrete characteristics are improved: density, final strengths, freeze/thaw and chemical resistances, watertightness, less cracking and shrinkage. In addition, MEYCO TCC 735 also improves pumpability and workability of shotcrete, even with low-grade aggregates. It particularly improves the pumpability of steel fiber reinforced shotcrete mixes. In combination with the MEYCO TCC system it contrives to even increase the beneficial effects of the slump killing system by further improving fiber orientation, reducing fiber rebound and thus raising toughness values.

  10. Physicochemical compatibility of nebulizable drug admixtures containing colistimethate and tobramycin.

    PubMed

    Wollstadt, A; Krämer, I; Kamin, W

    2013-09-01

    Inhalation therapy with nebulizable antibiotic drugs is a mainstay in treating Pseudomonas aeruginosa infections in cystic fibrosis patients. The combination of tobramycin and colistin was found to be superior to monotherapy in killing P. aeruginosa in biofilms. The simultaneous inhalation of tobramycin and colistin might be an option to increase the compliance of patients. The objective of this in-vitro study was to determine whether admixtures of inhalation solutions containing colistin methanesulfonate (CMS) and tobramycin are physicochemically compatible. Physical compatibility was determined by measuring pH and osmolality. Chemical compatibility was determined by testing the antibiotic activity of the mixtures by the pharmacopoeial microbiological assay and comparing the results to those of standard solutions. Samples were analyzed immediately after mixing and after 24 h. Values of pH and osmolality remained unchanged and in physiologically acceptable ranges. Neither for colistin methanesulfonate (CMS) nor for tobramycin losses of antibiotic potency were registered at any time. Admixtures of nebulizer solutions containing CMS and tobramycin were shown to be physicochemically compatible. Further investigations are needed to determine whether drug delivery is affected by mixing the nebulizer solutions to ensure that simultaneous inhalation is recommendable. PMID:24147342

  11. Mapping Regional Drought Vulnerability: a Case Study

    NASA Astrophysics Data System (ADS)

    Karamouz, M.; Zeynolabedin, A.; Olyaei, M. A.

    2015-12-01

    Drought is among the natural disaster that causes damages and affects many people's life in many part of the world including in Iran. Recently, some factors such as climate variability and the impact of climate change have influenced drought frequency and intensity in many parts of the world. Drought can be divided into four categories of meteorological, hydrological, agricultural and social-economic. In meteorological the important feature is lack of rainfall. In hydrological drought river flows and dam storage are considered. Lack of soil moisture is the key factor in agricultural droughts while in social-economic type of drought the relation between supply and demand and social-economic damages due to water deficiency is studied. While the first three types relates to the lack of some hydrological characteristics, social-economic type of drought is actually the consequence of other types expressed in monetary values. Many indices are used in assessing drought; each has its own advantages and disadvantages and can be used for specific types of drought. Therefore knowing the types of drought can provide a better understanding of shortages and their characteristics. Drought vulnerability is a concept which shows the likelihood of damages from hazard in a particular place by focusing on the system status prior to the disaster. Drought vulnerability has been viewed as a potential for losses in the region due to water deficiency at the time of drought. In this study the application of vulnerability concept in drought management in East Azarbaijan province in Iran is investigated by providing vulnerability maps which demonstrates spatial characteristics of drought vulnerability. In the first step, certain governing parameters in drought analysis such as precipitation, temperature, land use, topography, solar radiation and ground water elevation have been investigated in the region. They are described in details and calculated in suitable time series. Vulnerabilities

  12. Seismicity map tools for earthquake studies

    NASA Astrophysics Data System (ADS)

    Boucouvalas, Anthony; Kaskebes, Athanasios; Tselikas, Nikos

    2014-05-01

    We report on the development of new and online set of tools for use within Google Maps, for earthquake research. We demonstrate this server based and online platform (developped with PHP, Javascript, MySQL) with the new tools using a database system with earthquake data. The platform allows us to carry out statistical and deterministic analysis on earthquake data use of Google Maps and plot various seismicity graphs. The tool box has been extended to draw on the map line segments, multiple straight lines horizontally and vertically as well as multiple circles, including geodesic lines. The application is demonstrated using localized seismic data from the geographic region of Greece as well as other global earthquake data. The application also offers regional segmentation (NxN) which allows the studying earthquake clustering, and earthquake cluster shift within the segments in space. The platform offers many filters such for plotting selected magnitude ranges or time periods. The plotting facility allows statistically based plots such as cumulative earthquake magnitude plots and earthquake magnitude histograms, calculation of 'b' etc. What is novel for the platform is the additional deterministic tools. Using the newly developed horizontal and vertical line and circle tools we have studied the spatial distribution trends of many earthquakes and we here show for the first time the link between Fibonacci Numbers and spatiotemporal location of some earthquakes. The new tools are valuable for examining visualizing trends in earthquake research as it allows calculation of statistics as well as deterministic precursors. We plan to show many new results based on our newly developed platform.

  13. Preferred Reporting Items for Studies Mapping onto Preference-Based Outcome Measures: The MAPS Statement.

    PubMed

    Petrou, Stavros; Rivero-Arias, Oliver; Dakin, Helen; Longworth, Louise; Oppe, Mark; Froud, Robert; Gray, Alastair

    2015-10-01

    'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite the publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication. A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprising six health economists and one Delphi methodologist. Following a two-round modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user-friendly 23-item checklist. They are presented numerically and categorised within six sections, namely: (1) title and abstract; (2) introduction; (3) methods; (4) results; (5) discussion; and (6) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document. It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by seven health economics and quality-of-life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in 5 years' time. PMID:26232201

  14. Preferred reporting items for studies mapping onto preference-based outcome measures: The MAPS statement.

    PubMed

    Petrou, Stavros; Rivero-Arias, Oliver; Dakin, Helen; Longworth, Louise; Oppe, Mark; Froud, Robert; Gray, Alastair

    2015-01-01

    'Mapping' onto generic preference-based outcome measures is increasingly being used as a means of generating health utilities for use within health economic evaluations. Despite publication of technical guides for the conduct of mapping research, guidance for the reporting of mapping studies is currently lacking. The MAPS (MApping onto Preference-based measures reporting Standards) statement is a new checklist, which aims to promote complete and transparent reporting of mapping studies. The primary audiences for the MAPS statement are researchers reporting mapping studies, the funders of the research, and peer reviewers and editors involved in assessing mapping studies for publication.A de novo list of 29 candidate reporting items and accompanying explanations was created by a working group comprised of six health economists and one Delphi methodologist. Following a two-round, modified Delphi survey with representatives from academia, consultancy, health technology assessment agencies and the biomedical journal editorial community, a final set of 23 items deemed essential for transparent reporting, and accompanying explanations, was developed. The items are contained in a user friendly 23 item checklist. They are presented numerically and categorised within six sections, namely: (i) title and abstract; (ii) introduction; (iii) methods; (iv) results; (v) discussion; and (vi) other. The MAPS statement is best applied in conjunction with the accompanying MAPS explanation and elaboration document.It is anticipated that the MAPS statement will improve the clarity, transparency and completeness of reporting of mapping studies. To facilitate dissemination and uptake, the MAPS statement is being co-published by eight health economics and quality of life journals, and broader endorsement is encouraged. The MAPS working group plans to assess the need for an update of the reporting checklist in five years' time.This statement was published jointly in Applied Health Economics

  15. Overfill of common piggyback admixture solutions.

    PubMed

    Kleinberg, M L; Chang, P

    1984-10-01

    The average final volume of 23 commonly used piggyback solutions was determined. Polyvinyl chloride (PVC) containers filled with 0.9% sodium chloride injection or 5% dextrose injection in 50 ml and 100 ml sizes were used for 20 of the piggybacks. A total of ten samples of each drug and dose were measured by draining the entire contents into a graduated cylinder and measuring the volume. The mean volumes, standard deviations, and ranges for each drug and dose were calculated. The volume found in each sample exceeded the volume in the original PVC container by at least 20% in the 50 ml size and 11% in the 100 ml size. The greatest percentage volume difference was 62% in the 50 ml size and 28% in the 100 ml size. The FasPak and the two Viaflex Plus Ready-To-Use containers, which did not require the use of the 50 and 100 ml PVC containers, had a percentage volume difference of 2.6%, 2.2%, and 3.4%, respectively. This information demonstrates the fact that the final volumes of some piggyback admixtures are significantly greater than that which may be presumed from the admixture label. PMID:10268316

  16. A single-tube 27-plex SNP assay for estimating individual ancestry and admixture from three continents.

    PubMed

    Wei, Yi-Liang; Wei, Li; Zhao, Lei; Sun, Qi-Fan; Jiang, Li; Zhang, Tao; Liu, Hai-Bo; Chen, Jian-Gang; Ye, Jian; Hu, Lan; Li, Cai-Xia

    2016-01-01

    A single-tube multiplex assay of a small set of ancestry-informative markers (AIMs) for effectively estimating individual ancestry and admixture is an ideal forensic tool to trace the population origin of an unknown DNA sample. We present a newly developed 27-plex single nucleotide polymorphism (SNP) panel with highly robust and balanced differential power to perfectly assign individuals to African, European, and East Asian ancestries. Evaluating 968 previously described intercontinental AIMs from three HapMap population genotyping datasets (Yoruban in Ibadan, Nigeria (YRI); Utah residents with Northern and Western European ancestry from the Centre de'Etude du Polymorphism Humain (CEPH) collection (CEU); and Han Chinese in Beijing, China (CHB)), the best set of markers was selected on the basis of Hardy-Weinberg equilibrium (p > 0.00001), population-specific allele frequency (two of three δ values >0.5), according to linkage disequilibrium (r (2) < 0.2), and capable of being multiplexed in one tube and detected by capillary electrophoresis. The 27-SNP panel was first validated by assigning the ancestry of the 11 populations in the HapMap project. Then, we tested the 27-plex SNP assay with 1164 individuals from 17 additional populations. The results demonstrated that the SNP panel was successful for ancestry inference of individuals with African, European, and East Asian ancestry. Furthermore, the system performed well when inferring the admixture of Eurasians (EUR/EAS) after analyzing admixed populations from Xinjiang (Central Asian) as follows: Tajik (68:27), Uyghur (49:46), Kirgiz (40:57), and Kazak (36:60). For individual analyses, we interpreted each sample with a three-ancestry component percentage and a population match probability sequence. This multiplex assay is a convenient and cost-effective tool to assist in criminal investigations, as well as to correct for the effects of population stratification for case-control studies. PMID:25833170

  17. Inferring admixture histories of human populations using linkage disequilibrium.

    PubMed

    Loh, Po-Ru; Lipson, Mark; Patterson, Nick; Moorjani, Priya; Pickrell, Joseph K; Reich, David; Berger, Bonnie

    2013-04-01

    Long-range migrations and the resulting admixtures between populations have been important forces shaping human genetic diversity. Most existing methods for detecting and reconstructing historical admixture events are based on allele frequency divergences or patterns of ancestry segments in chromosomes of admixed individuals. An emerging new approach harnesses the exponential decay of admixture-induced linkage disequilibrium (LD) as a function of genetic distance. Here, we comprehensively develop LD-based inference into a versatile tool for investigating admixture. We present a new weighted LD statistic that can be used to infer mixture proportions as well as dates with fewer constraints on reference populations than previous methods. We define an LD-based three-population test for admixture and identify scenarios in which it can detect admixture events that previous formal tests cannot. We further show that we can uncover phylogenetic relationships among populations by comparing weighted LD curves obtained using a suite of references. Finally, we describe several improvements to the computation and fitting of weighted LD curves that greatly increase the robustness and speed of the calculations. We implement all of these advances in a software package, ALDER, which we validate in simulations and apply to test for admixture among all populations from the Human Genome Diversity Project (HGDP), highlighting insights into the admixture history of Central African Pygmies, Sardinians, and Japanese. PMID:23410830

  18. Strategy Maps in University Management: A Comparative Study

    ERIC Educational Resources Information Center

    Han, Shuangmiao; Zhong, Zhou

    2015-01-01

    In this study, the conceptual use of the strategy map approach and the strategy map which it produces have been adapted from the business sector and introduced as tools for achieving more effective strategic planning and management in higher education institutions (HEIs). This study discusses the development of strategy maps as transformational…

  19. Recycling of tailings from Korea Molybdenum Corporation as admixture for high-fluidity concrete.

    PubMed

    Jung, Moon Young; Choi, Yun Wang; Jeong, Jae Gwon

    2011-01-01

    The main objective of this study is to develop an eco-friendly and a large recycling technique of flotation Tailings from korea (TK) from metal mines as construction materials such as admixtures for high-fluidity concrete (HFC). TK used in this study was obtained from the Korea Molybdenum Corporation in operation. TK was used as the alternative material to adjust flowability and viscosity of HFC in the form of powder agent which enables adjustment of concrete compressive strength. In this study, we have performed concrete rheological tests and concrete flowability tests to obtain the quality characteristics of TK for using as the admixture in producing HFC. The results indicated that the adequate mix ratio of cement to TK should be 8:2 (vol%). It is more effective to use the TK as admixture to control flowability, viscosity and strength of HFC than the normal concrete. It was found that TK could be recycled construction materials in bulk such as admixture for HFC, in terms of the economic and eco-friendly aspects. PMID:21113645

  20. Deciphering the fine-structure of tribal admixture in the Bedouin population using genomic data

    PubMed Central

    Markus, B; Alshafee, I; Birk, O S

    2014-01-01

    The Bedouin Israeli population is highly inbred and structured with a very high prevalence of recessive diseases. Many studies in the past two decades focused on linkage analysis in large, multiple consanguineous pedigrees of this population. The advent of high-throughput technologies motivated researchers to search for rare variants shared between smaller pedigrees, integrating data from clinically similar yet seemingly non-related sporadic cases. However, such analyses are challenging because, without pedigree data, there is no prior knowledge regarding possible relatedness between the sporadic cases. Here, we describe models and techniques for the study of relationships between pedigrees and use them for the inference of tribal co-ancestry, delineating the complex social interactions between different tribes in the Negev Bedouins of southern Israel. Through our analysis, we differentiate between tribes that share many yet small genomic segments because of co-ancestry versus tribes that share larger segments because of recent admixture. The emergent pattern is well correlated with the prevalence of rare mutations in the different tribes. Tribes that do not intermarry, mostly because of social restrictions, hold private mutations, whereas tribes that do intermarry demonstrate a genetic flow of mutations between them. Thus, social structure within an inbred community can be delineated through genomic data, with implications to genetic counseling and genetic mapping. PMID:24084643

  1. Preserving immune diversity through ancient inheritance and admixture.

    PubMed

    Ségurel, Laure; Quintana-Murci, Lluis

    2014-10-01

    The progress of genomic technologies is allowing researchers to scan the genomes of different species for the occurrence of natural selection at an unprecedented level of resolution. These studies show that genes involved in immune processes are preferential targets of different forms of selection, some of which act to preserve immune diversity over time. Recent work in humans shows that this can be achieved either by inheriting advantageous immune variation from distant ancestral species, through long-term balancing selection, or by acquiring novel selected alleles through admixture with extinct hominins such as Neanderthals or Denisovans. These studies collectively increase our knowledge of immune genes for which maintaining the functional diversity has conferred a strong selective advantage for host survival. PMID:25190608

  2. Case studies: Soil mapping using multiple methods

    NASA Astrophysics Data System (ADS)

    Petersen, Hauke; Wunderlich, Tina; Hagrey, Said A. Al; Rabbel, Wolfgang; Stümpel, Harald

    2010-05-01

    Soil is a non-renewable resource with fundamental functions like filtering (e.g. water), storing (e.g. carbon), transforming (e.g. nutrients) and buffering (e.g. contamination). Degradation of soils is meanwhile not only to scientists a well known fact, also decision makers in politics have accepted this as a serious problem for several environmental aspects. National and international authorities have already worked out preservation and restoration strategies for soil degradation, though it is still work of active research how to put these strategies into real practice. But common to all strategies the description of soil state and dynamics is required as a base step. This includes collecting information from soils with methods ranging from direct soil sampling to remote applications. In an intermediate scale mobile geophysical methods are applied with the advantage of fast working progress but disadvantage of site specific calibration and interpretation issues. In the framework of the iSOIL project we present here some case studies for soil mapping performed using multiple geophysical methods. We will present examples of combined field measurements with EMI-, GPR-, magnetic and gammaspectrometric techniques carried out with the mobile multi-sensor-system of Kiel University (GER). Depending on soil type and actual environmental conditions, different methods show a different quality of information. With application of diverse methods we want to figure out, which methods or combination of methods will give the most reliable information concerning soil state and properties. To investigate the influence of varying material we performed mapping campaigns on field sites with sandy, loamy and loessy soils. Classification of measured or derived attributes show not only the lateral variability but also gives hints to a variation in the vertical distribution of soil material. For all soils of course soil water content can be a critical factor concerning a succesful

  3. Ancestry, admixture and fitness in Colombian genomes

    PubMed Central

    Rishishwar, Lavanya; Conley, Andrew B.; Wigington, Charles H.; Wang, Lu; Valderrama-Aguirre, Augusto; King Jordan, I.

    2015-01-01

    The human dimension of the Columbian Exchange entailed substantial genetic admixture between ancestral source populations from Africa, the Americas and Europe, which had evolved separately for many thousands of years. We sought to address the implications of the creation of admixed American genomes, containing novel allelic combinations, for human health and fitness via analysis of an admixed Colombian population from Medellin. Colombian genomes from Medellin show a wide range of three-way admixture contributions from ancestral source populations. The primary ancestry component for the population is European (average = 74.6%, range = 45.0%–96.7%), followed by Native American (average = 18.1%, range = 2.1%–33.3%) and African (average = 7.3%, range = 0.2%–38.6%). Locus-specific patterns of ancestry were evaluated to search for genomic regions that are enriched across the population for particular ancestry contributions. Adaptive and innate immune system related genes and pathways are particularly over-represented among ancestry-enriched segments, including genes (HLA-B and MAPK10) that are involved in defense against endemic pathogens such as malaria. Genes that encode functions related to skin pigmentation (SCL4A5) and cutaneous glands (EDAR) are also found in regions with anomalous ancestry patterns. These results suggest the possibility that ancestry-specific loci were differentially retained in the modern admixed Colombian population based on their utility in the New World environment. PMID:26197429

  4. Efficient moment-based inference of admixture parameters and sources of gene flow.

    PubMed

    Lipson, Mark; Loh, Po-Ru; Levin, Alex; Reich, David; Patterson, Nick; Berger, Bonnie

    2013-08-01

    The recent explosion in available genetic data has led to significant advances in understanding the demographic histories of and relationships among human populations. It is still a challenge, however, to infer reliable parameter values for complicated models involving many populations. Here, we present MixMapper, an efficient, interactive method for constructing phylogenetic trees including admixture events using single nucleotide polymorphism (SNP) genotype data. MixMapper implements a novel two-phase approach to admixture inference using moment statistics, first building an unadmixed scaffold tree and then adding admixed populations by solving systems of equations that express allele frequency divergences in terms of mixture parameters. Importantly, all features of the model, including topology, sources of gene flow, branch lengths, and mixture proportions, are optimized automatically from the data and include estimates of statistical uncertainty. MixMapper also uses a new method to express branch lengths in easily interpretable drift units. We apply MixMapper to recently published data for Human Genome Diversity Cell Line Panel individuals genotyped on a SNP array designed especially for use in population genetics studies, obtaining confident results for 30 populations, 20 of them admixed. Notably, we confirm a signal of ancient admixture in European populations-including previously undetected admixture in Sardinians and Basques-involving a proportion of 20-40% ancient northern Eurasian ancestry. PMID:23709261

  5. The scale and nature of Viking settlement in Ireland from Y-chromosome admixture analysis.

    PubMed

    McEvoy, Brian; Brady, Claire; Moore, Laoise T; Bradley, Daniel G

    2006-12-01

    The Vikings (or Norse) played a prominent role in Irish history but, despite this, their genetic legacy in Ireland, which may provide insights into the nature and scale of their immigration, is largely unexplored. Irish surnames, some of which are thought to have Norse roots, are paternally inherited in a similar manner to Y-chromosomes. The correspondence of Scandinavian patrilineal ancestry in a cohort of Irish men bearing surnames of putative Norse origin was examined using both slow mutating unique event polymorphisms and relatively rapidly changing short tandem repeat Y-chromosome markers. Irish and Scandinavian admixture proportions were explored for both systems using six different admixture estimators, allowing a parallel investigation of the impact of method and marker type in Y-chromosome admixture analysis. Admixture proportion estimates in the putative Norse surname group were highly consistent and detected little trace of Scandinavian ancestry. In addition, there is scant evidence of Scandinavian Y-chromosome introgression in a general Irish population sample. Although conclusions are largely dependent on the accurate identification of Norse surnames, the findings are consistent with a relatively small number of Norse settlers (and descendents) migrating to Ireland during the Viking period (ca. AD 800-1200) suggesting that Norse colonial settlements might have been largely composed of indigenous Irish. This observation adds to previous genetic studies that point to a flexible Viking settlement approach across North Atlantic Europe. PMID:16957681

  6. Learning from Concept Mapping and Hypertext: An Eye Tracking Study

    ERIC Educational Resources Information Center

    Amadieu, Franck; Salmerón, Ladislao; Cegarra, Julien; Paubel, Pierre-Vincent; Lemarié, Julie; Chevalier, Aline

    2015-01-01

    This study examined the effects of prior domain knowledge and learning sequences on learning with concept mapping and hypertext. Participants either made a concept map in a first step and then read the hypertext's contents combined with concept mapping (high activating condition), or they read the hypertext's contents first and then made a concept…

  7. Self-Mapping in Treating Suicide Ideation: A Case Study

    ERIC Educational Resources Information Center

    Robertson, Lloyd Hawkeye

    2011-01-01

    This case study traces the development and use of a self-mapping exercise in the treatment of a youth who had been at risk for re-attempting suicide. A life skills exercise was modified to identify units of culture called "memes" from which a map of the youth's self was prepared. A successful treatment plan followed the mapping exercise. The…

  8. Computer-Based Concept Mapping: Active Studying for Active Learners.

    ERIC Educational Resources Information Center

    Anderson-Inman, Lynne; Zeitz, Leigh

    1993-01-01

    Describes the use of computer-generated concept maps using a new genre of graphics programs that allows students to create, alter and expand maps as they acquire more subject matter knowledge. Four examples of increasingly complex concept maps developed by a high school student studying cellular biology are discussed and illustrated. (Contains 19…

  9. Interethnic variability and admixture in Latin America--social implications.

    PubMed

    Salzano, Francisco M

    2004-09-01

    Past and present attempts to classify and characterize the human biological variability are examined, considering the race concept, ethnic identification problems, assortative mating based on ethnicity, and historical genetics. In relation to the latter, a review is made of the methods presently available for admixture quantification and of previous studies aimed at the characterization of the parental continental contributions to Latin American populations, with emphasis in global evaluations of the Costa Rican and Brazilian gene pools. Finally, the question of racism and discrimination is considered, including the relation between human rights and affirmative actions. The right to equal opportunity should be strictly respected. Biological inequality has nothing to do with the ethical principle that someone's position in a given society should be an accurate reflection of her/his individual ability. PMID:17361535

  10. Pharmacogenomic implications of population admixture: Brazil as a model case.

    PubMed

    Suarez-Kurtz, Guilherme; Paula, Daniela Polessa; Struchiner, Claudio J

    2014-02-01

    The heterogeneous Brazilian population, with European, African and Amerindian ancestral roots is a model case for exploring the impact of population admixture on the frequency distribution of polymorphisms in pharmacogenes, and the design and interpretation of pharmacogenomics trials. Examples drawn from studies carried out by researchers of the Brazilian pharmacogenomics network, support the following conclusions: the distribution of polymorphisms varies across geographical regions and self-reported 'race/color' categories, and is best modeled as continuous functions of individual proportions of European and African ancestry; the differential frequency of polymorphisms impacts the calculations of sample sizes required for adequate statistical power in clinical trials performed in different segments of the Brazilian population; and extrapolation of pharmacogenomics data from well-defined ethnic groups to Brazilians is plagued with uncertainty. Data for warfarin and tacrolimus are reviewed to highlight the advantages and challenges of performing pharmacogenomic trials in Brazilians. PMID:24444410

  11. Used cooking oil as a green chemical admixture in concrete

    NASA Astrophysics Data System (ADS)

    Salmia, B.; Che Muda, Zakaria; Ashraful Alam, Md; Sidek, L. M.; Hidayah, B.

    2013-06-01

    According to National Statistics Approximately 1.35 billion gallons of used oil are generated yearly. With the increasing of the concrete usage, a more cost effective and economic new type of admixtures may give positive impacts on the Malaysian construction building as well as worldwide concrete usage. To objective of this is study is to investigate the effect of used cooking oil in terms of slump test, compressive strength test and rebound hammer. By adding the used cooking oil to the concrete, it increases the slump value from 4% to 72%. And the compressive strength have an increment from 1% to 16.8%. The used cooking oil obtains the optimum contribution to the concrete mix proportion of containing used cooking oil of 1.50% from the cement content. The result of used cooking oil from experimental program of slump value and compressive strength proved that used cooking oil have positive effects on replacement of commercially available superplasticizer.

  12. Further characterization of theobroma oil-beeswax admixtures as lipid matrices for improved drug delivery systems.

    PubMed

    Attama, A A; Schicke, B C; Müller-Goymann, C C

    2006-11-01

    There is an increasing interest in lipid based drug delivery systems due to factors such as better characterization of lipidic excipients and formulation versatility and the choice of different drug delivery systems. It is important to know the thermal characteristics, crystal habit, texture, and appearance of a new lipid matrix when determining its suitability for use in certain pharmaceutical application. It is line with this that this research was embarked upon to characterize mixtures of beeswax and theobroma oil with a view to applying their admixtures in drug delivery systems such as solid lipid nanoparticles and nanostructured lipid carriers. Admixtures of theobroma oil and beeswax were prepared to contain 25% w/w, 50% w/w, and 75% w/w of theobroma oil. The admixtures were analyzed by differential scanning calorimetry (DSC), small angle X-ray diffraction (SAXD), wide angle X-ray diffraction (WAXD), and isothermal heat conduction microcalorimetry (IMC). The melting behavior and microstructures of the lipid admixtures were monitored by polarized light microscopy (PLM). Transmission electron microscopy (TEM) was used to study the internal structures of the lipid bases. DSC traces indicated that the higher melting peaks were roughly constant for the different admixtures, but lower melting peaks significantly increased (p < 0.05). The admixture containing 25% w/w of theobroma oil possessed highest crystallinity index of 95.6%. WAXD studies indicated different reflections for the different lipid matrices. However, new interferences were detected for all the lipid matrix admixtures between 2theta = 22.0 degrees and 2theta = 25.0 degrees. The lipid matrices containing 50% w/w and 25% w/w of theobroma oil showed absence of the weak reflection characteristic of pure theobroma oil, while there was disappearance of the strong intensity reflection of beeswax in all the lipid matrix admixtures at all stages of the study. PLM micrographs revealed differences with regard to

  13. The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape.

    PubMed

    Busby, George B J; Hellenthal, Garrett; Montinaro, Francesco; Tofanelli, Sergio; Bulayeva, Kazima; Rudan, Igor; Zemunik, Tatijana; Hayward, Caroline; Toncheva, Draga; Karachanak-Yankova, Sena; Nesheva, Desislava; Anagnostou, Paolo; Cali, Francesco; Brisighelli, Francesca; Romano, Valentino; Lefranc, Gerard; Buresi, Catherine; Ben Chibani, Jemni; Haj-Khelil, Amel; Denden, Sabri; Ploski, Rafal; Krajewski, Pawel; Hervig, Tor; Moen, Torolf; Herrera, Rene J; Wilson, James F; Myers, Simon; Capelli, Cristian

    2015-10-01

    Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1-7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled or have been either too regional or global in their outlook [8-11]. Here, using recently described haplotype-based techniques [11], we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200 CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1,500 years are likely to have maintained differentiation among groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. PMID:26387712

  14. The Role of Recent Admixture in Forming the Contemporary West Eurasian Genomic Landscape

    PubMed Central

    Busby, George B.J.; Hellenthal, Garrett; Montinaro, Francesco; Tofanelli, Sergio; Bulayeva, Kazima; Rudan, Igor; Zemunik, Tatijana; Hayward, Caroline; Toncheva, Draga; Karachanak-Yankova, Sena; Nesheva, Desislava; Anagnostou, Paolo; Cali, Francesco; Brisighelli, Francesca; Romano, Valentino; Lefranc, Gerard; Buresi, Catherine; Ben Chibani, Jemni; Haj-Khelil, Amel; Denden, Sabri; Ploski, Rafal; Krajewski, Pawel; Hervig, Tor; Moen, Torolf; Herrera, Rene J.; Wilson, James F.; Myers, Simon; Capelli, Cristian

    2015-01-01

    Summary Over the past few years, studies of DNA isolated from human fossils and archaeological remains have generated considerable novel insight into the history of our species. Several landmark papers have described the genomes of ancient humans across West Eurasia, demonstrating the presence of large-scale, dynamic population movements over the last 10,000 years, such that ancestry across present-day populations is likely to be a mixture of several ancient groups [1, 2, 3, 4, 5, 6, 7]. While these efforts are bringing the details of West Eurasian prehistory into increasing focus, studies aimed at understanding the processes behind the generation of the current West Eurasian genetic landscape have been limited by the number of populations sampled or have been either too regional or global in their outlook [8, 9, 10, 11]. Here, using recently described haplotype-based techniques [11], we present the results of a systematic survey of recent admixture history across Western Eurasia and show that admixture is a universal property across almost all groups. Admixture in all regions except North Western Europe involved the influx of genetic material from outside of West Eurasia, which we date to specific time periods. Within Northern, Western, and Central Europe, admixture tended to occur between local groups during the period 300 to 1200 CE. Comparisons of the genetic profiles of West Eurasians before and after admixture show that population movements within the last 1,500 years are likely to have maintained differentiation among groups. Our analysis provides a timeline of the gene flow events that have generated the contemporary genetic landscape of West Eurasia. PMID:26387712

  15. Multiway admixture deconvolution using phased or unphased ancestral panels.

    PubMed

    Churchhouse, Claire; Marchini, Jonathan

    2013-01-01

    We describe a novel method for inferring the local ancestry of admixed individuals from dense genome-wide single nucleotide polymorphism data. The method, called MULTIMIX, allows multiple source populations, models population linkage disequilibrium between markers and is applicable to datasets in which the sample and source populations are either phased or unphased. The model is based upon a hidden Markov model of switches in ancestry between consecutive windows of loci. We model the observed haplotypes within each window using a multivariate normal distribution with parameters estimated from the ancestral panels. We present three methods to fit the model-Markov chain Monte Carlo sampling, the Expectation Maximization algorithm, and a Classification Expectation Maximization algorithm. The performance of our method on individuals simulated to be admixed with European and West African ancestry shows it to be comparable to HAPMIX, the ancestry calls of the two methods agreeing at 99.26% of loci across the three parameter groups. In addition to it being faster than HAPMIX, it is also found to perform well over a range of extent of admixture in a simulation involving three ancestral populations. In an analysis of real data, we estimate the contribution of European, West African and Native American ancestry to each locus in the Mexican samples of HapMap, giving estimates of ancestral proportions that are consistent with those previously reported. PMID:23136122

  16. Phenotypic evolution of human craniofacial morphology after admixture: a geometric morphometrics approach.

    PubMed

    Martínez-Abadías, Neus; González-José, Rolando; González-Martín, Antonio; Van der Molen, Silvina; Talavera, Arturo; Hernández, Patricia; Hernández, Miquel

    2006-03-01

    An evolutionary, diachronic approach to the phenotypic craniofacial pattern arisen in a human population after high levels of admixture and gene flow was achieved by means of geometric morphometrics. Admixture has long been studied after molecular data. Nevertheless, few efforts have been made to explain the morphological outcome in human craniofacial samples. The Spanish-Amerindian contact can be considered a good scenario for such an analysis. Here we present a comparative analysis of craniofacial shape changes observed between two putative ancestor groups, Spanish and precontact Aztecs, and two diachronic admixed groups, corresponding to early and late colonial periods from the Mexico's Central Valley. Quantitative shape comparisons of Amerindian, Spanish, and admixed groups were used to test the expectations of quantitative genetics for admixture events. In its simplest form, this prediction states that an admixed group will present phenotypic values falling between those of both parental groups. Results show that, in general terms, although the human skull is a complex, integrated structure, the craniofacial morphology observed fits the theoretical expectations of quantitative genetics. Thus, it is predictive of population structure and history. In fact, results obtained after the craniofacial analysis are in accordance with previous molecular and historical interpretations, providing evidence that admixture is a main microevolutionary agent influencing modern Mexican gene pool. However, expectations are not straightforward when moderate shape changes are considered. Deviations detected at localized structures, such as the upper and lower face, highlight the evolution of a craniofacial pattern exclusively inherent to the admixed groups, indicating that quantitative characters might respond to admixture in a complicated, nondirectional way. PMID:16323202

  17. [The development of a dispensing cabinet of total nutrient admixture].

    PubMed

    Wu, Xiao-an

    2002-03-01

    A dispensing cabinet of total nutrient admixture is introduced in this paper. Which can be used for nutrient solution dispensing. The clinical application shows that it can provide a practical, simple, safe and satisfactory sterile environment. PMID:16104182

  18. Identifying environmental sounds: a multimodal mapping study

    PubMed Central

    Tomasino, Barbara; Canderan, Cinzia; Marin, Dario; Maieron, Marta; Gremese, Michele; D'Agostini, Serena; Fabbro, Franco; Skrap, Miran

    2015-01-01

    Our environment is full of auditory events such as warnings or hazards, and their correct recognition is essential. We explored environmental sounds (ES) recognition in a series of studies. In study 1 we performed an Activation Likelihood Estimation (ALE) meta-analysis of neuroimaging experiments addressing ES processing to delineate the network of areas consistently involved in ES processing. Areas consistently activated in the ALE meta-analysis were the STG/MTG, insula/rolandic operculum, parahippocampal gyrus and inferior frontal gyrus bilaterally. Some of these areas truly reflect ES processing, whereas others are related to design choices, e.g., type of task, type of control condition, type of stimulus. In study 2 we report on 7 neurosurgical patients with lesions involving the areas which were found to be activated by the ALE meta-analysis. We tested their ES recognition abilities and found an impairment of ES recognition. These results indicate that deficits of ES recognition do not exclusively reflect lesions to the right or to the left hemisphere but both hemispheres are involved. The most frequently lesioned area is the hippocampus/insula/STG. We made sure that any impairment in ES recognition would not be related to language problems, but reflect impaired ES processing. In study 3 we carried out an fMRI study on patients (vs. healthy controls) to investigate how the areas involved in ES might be functionally deregulated because of a lesion. The fMRI evidenced that controls activated the right IFG, the STG bilaterally and the left insula. We applied a multimodal mapping approach and found that, although the meta-analysis showed that part of the left and right STG/MTG activation during ES processing might in part be related to design choices, this area was one of the most frequently lesioned areas in our patients, thus highlighting its causal role in ES processing. We found that the ROIs we drew on the two clusters of activation found in the left and in

  19. Dyslipidemia and insulin resistance in relation to genetic admixture among Hispanics and non-Hispanic blacks of Caribbean origin.

    PubMed Central

    Tull, Eugene S.; Thurland, Ann

    2004-01-01

    The tendency to develop insulin resistance and dyslipidemia varies between black Africans, white Europeans, and Amerindian racial groups. Genetic admixture of these three racial groups has resulted in hybrid populations of Hispanics and non-Hispanic blacks. The current study was undertaken to examine the relationship of white European admixture to insulin resistance and dyslipidemia among Hispanics and non-Hispanic blacks of Caribbean origin. The study population included 224 Hispanics and 684 non-Hispanic blacks without a history of diabetes who were recruited between 1995 and 1999 on the island of St. Croix in the U.S. Virgin Islands. For each participant, anthropometric measurements were performed, and a fasting blood sample was analyzed for glucose, insulin, and serum lipids (triglycerides, HDL cholesterol). Genetic admixture was determined from grandparent race data. Hispanics were more likely than non-Hispanic blacks to have dyslipidemia and insulin resistance (measured by HOMA-IR method). White European admixture was significantly and inversely associated with insulin resistance among Hispanics. There was no significant relationship between white European admixture and insulin resistance or dyslipidemia among non-Hispanic blacks. Individuals who classified themselves as Hispanic blacks appeared to have a greater risk for cardiovascular disease than Hispanic whites or non-Hispanic blacks. Images Figure 1 Figure 2 PMID:15040515

  20. Genome-wide scan of 29,141 African Americans finds no evidence of directional selection since admixture.

    PubMed

    Bhatia, Gaurav; Tandon, Arti; Patterson, Nick; Aldrich, Melinda C; Ambrosone, Christine B; Amos, Christopher; Bandera, Elisa V; Berndt, Sonja I; Bernstein, Leslie; Blot, William J; Bock, Cathryn H; Caporaso, Neil; Casey, Graham; Deming, Sandra L; Diver, W Ryan; Gapstur, Susan M; Gillanders, Elizabeth M; Harris, Curtis C; Henderson, Brian E; Ingles, Sue A; Isaacs, William; De Jager, Phillip L; John, Esther M; Kittles, Rick A; Larkin, Emma; McNeill, Lorna H; Millikan, Robert C; Murphy, Adam; Neslund-Dudas, Christine; Nyante, Sarah; Press, Michael F; Rodriguez-Gil, Jorge L; Rybicki, Benjamin A; Schwartz, Ann G; Signorello, Lisa B; Spitz, Margaret; Strom, Sara S; Tucker, Margaret A; Wiencke, John K; Witte, John S; Wu, Xifeng; Yamamura, Yuko; Zanetti, Krista A; Zheng, Wei; Ziegler, Regina G; Chanock, Stephen J; Haiman, Christopher A; Reich, David; Price, Alkes L

    2014-10-01

    The extent of recent selection in admixed populations is currently an unresolved question. We scanned the genomes of 29,141 African Americans and failed to find any genome-wide-significant deviations in local ancestry, indicating no evidence of selection influencing ancestry after admixture. A recent analysis of data from 1,890 African Americans reported that there was evidence of selection in African Americans after their ancestors left Africa, both before and after admixture. Selection after admixture was reported on the basis of deviations in local ancestry, and selection before admixture was reported on the basis of allele-frequency differences between African Americans and African populations. The local-ancestry deviations reported by the previous study did not replicate in our very large sample, and we show that such deviations were expected purely by chance, given the number of hypotheses tested. We further show that the previous study's conclusion of selection in African Americans before admixture is also subject to doubt. This is because the FST statistics they used were inflated and because true signals of unusual allele-frequency differences between African Americans and African populations would be best explained by selection that occurred in Africa prior to migration to the Americas. PMID:25242497

  1. Mapping.

    ERIC Educational Resources Information Center

    Kinney, Douglas M.; McIntosh, Willard L.

    1979-01-01

    The area of geological mapping in the United States in 1978 increased greatly over that reported in 1977; state geological maps were added for California, Idaho, Nevada, and Alaska last year. (Author/BB)

  2. Admixture patterns and genetic differentiation in negrito groups from West Malaysia estimated from genome-wide SNP data.

    PubMed

    Jinam, Timothy A; Phipps, Maude E; Saitou, Naruya

    2013-01-01

    Southeast Asia houses various culturally and linguistically diverse ethnic groups. In Malaysia, where the Malay, Chinese, and Indian ethnic groups form the majority, there exist minority groups such as the "negritos" who are believed to be descendants of the earliest settlers of Southeast Asia. Here we report patterns of genetic substructure and admixture in two Malaysian negrito populations (Jehai and Kensiu), using ~50,000 genome-wide single-nucleotide polymorphism (SNP) data. We found traces of recent admixture in both the negrito populations, particularly in the Jehai, with the Malay through principal component analysis and STRUCTURE analysis software, which suggested that the admixture was as recent as one generation ago. We also identified significantly differentiated nonsynonymous SNPs and haplotype blocks related to intracellular transport, metabolic processes, and detection of stimulus. These results highlight the different levels of admixture experienced by the two Malaysian negritos. Delineating admixture and differentiated genomic regions should be of importance in designing and interpretation of molecular anthropology and disease association studies. PMID:24297225

  3. Expert Concept Mapping Study on Mobile Learning

    ERIC Educational Resources Information Center

    Borner, Dirk; Glahn, Christian; Stoyanov, Slavi; Kalz, Marco; Specht, Marcus

    2010-01-01

    Purpose: The present paper introduces concept mapping as a structured participative conceptualization approach to identify clusters of ideas and opinions generated by experts within the domain of mobile learning. Utilizing this approach, the paper aims to contribute to a definition of key domain characteristics by identifying the main educational…

  4. Boundary detection in disease mapping studies.

    PubMed

    Lee, Duncan; Mitchell, Richard

    2012-07-01

    In disease mapping, the aim is to estimate the spatial pattern in disease risk over an extended geographical region, so that areas with elevated risks can be identified. A Bayesian hierarchical approach is typically used to produce such maps, which represents the risk surface with a set of random effects that exhibit a single global level of spatial smoothness. However, in complex urban settings, the risk surface is likely to exhibit localized rather than global spatial structure, including areas where the risk varies smoothly over space, as well as boundaries separating populations that are geographically adjacent but have very different risk profiles. Therefore, this paper proposes an approach for capturing localized spatial structure, including the identification of such risk boundaries. The effectiveness of the approach is tested by simulation, before being applied to lung cancer incidence data in Greater Glasgow, UK, between 2001 and 2005. PMID:22045911

  5. A study on aircraft map display location and orientation

    NASA Technical Reports Server (NTRS)

    Baty, D. L.; Wempe, T.; Huff, E.

    1973-01-01

    Six airline pilots participated in a fixed-based simulator study to determine the effects of two horizontal situation display (HSD/map) panel locations relative to the vertical situation display (VSD), and of three map orientations on manual piloting performance. Pilot comments and opinions were formally obtained. Significant performance differences were found between wind conditions and among pilots but not between map locations and orientations. The results also illustrate the potential tracking accuracy of such a display. Recommendations concerning display location and map orientation are made.

  6. StructMap: Elastic Distance Analysis of Electron Microscopy Maps for Studying Conformational Changes.

    PubMed

    Sanchez Sorzano, Carlos Oscar; Alvarez-Cabrera, Ana Lucia; Kazemi, Mohsen; Carazo, Jose María; Jonić, Slavica

    2016-04-26

    Single-particle electron microscopy (EM) has been shown to be very powerful for studying structures and associated conformational changes of macromolecular complexes. In the context of analyzing conformational changes of complexes, distinct EM density maps obtained by image analysis and three-dimensional (3D) reconstruction are usually analyzed in 3D for interpretation of structural differences. However, graphic visualization of these differences based on a quantitative analysis of elastic transformations (deformations) among density maps has not been done yet due to a lack of appropriate methods. Here, we present an approach that allows such visualization. This approach is based on statistical analysis of distances among elastically aligned pairs of EM maps (one map is deformed to fit the other map), and results in visualizing EM maps as points in a lower-dimensional distance space. The distances among points in the new space can be analyzed in terms of clusters or trajectories of points related to potential conformational changes. The results of the method are shown with synthetic and experimental EM maps at different resolutions. PMID:27119636

  7. The origin of early age expansions induced in cementitious materials containing shrinkage reducing admixtures

    SciTech Connect

    Sant, Gaurav; Lothenbach, Barbara; Juilland, Patrick; Le Saout, Gwenn; Weiss, Jason; Scrivener, Karen

    2011-03-15

    Studies on the early-age shrinkage behavior of cement pastes, mortars, and concretes containing shrinkage reducing admixtures (SRAs) have indicated these mixtures frequently exhibit an expansion shortly after setting. While the magnitude of the expansion has been noted to be a function of the chemistry of the cement and the admixture dosage; the cause of the expansion is not clearly understood. This investigation uses measurements of autogenous deformation, X-ray diffraction, pore solution analysis, thermogravimetry, and scanning electron microscopy to study the early-age properties and describe the mechanism of the expansion in OPC pastes made with and without SRA. The composition of the pore solution indicates that the presence of the SRA increases the portlandite oversaturation level in solution which can result in higher crystallization stresses which could lead to an expansion. This observation is supported by deformation calculations for the systems examined.

  8. Mapping asthma-associated variants in admixed populations

    PubMed Central

    Mersha, Tesfaye B.

    2015-01-01

    Admixed populations arise when two or more previously isolated populations interbreed. Mapping asthma susceptibility loci in an admixed population using admixture mapping (AM) involves screening the genome of individuals of mixed ancestry for chromosomal regions that have a higher frequency of alleles from a parental population with higher asthma risk as compared with parental population with lower asthma risk. AM takes advantage of the admixture created in populations of mixed ancestry to identify genomic regions where an association exists between genetic ancestry and asthma (in contrast to between the genotype of the marker and asthma). The theory behind AM is that chromosomal segments of affected individuals contain a significantly higher-than-average proportion of alleles from the high-risk parental population and thus are more likely to harbor disease–associated loci. Criteria to evaluate the applicability of AM as a gene mapping approach include: (1) the prevalence of the disease differences in ancestral populations from which the admixed population was formed; (2) a measurable difference in disease-causing alleles between the parental populations; (3) reduced linkage disequilibrium (LD) between unlinked loci across chromosomes and strong LD between neighboring loci; (4) a set of markers with noticeable allele-frequency differences between parental populations that contributes to the admixed population (single nucleotide polymorphisms (SNPs) are the markers of choice because they are abundant, stable, relatively cheap to genotype, and informative with regard to the LD structure of chromosomal segments); and (5) there is an understanding of the extent of segmental chromosomal admixtures and their interactions with environmental factors. Although genome-wide association studies have contributed greatly to our understanding of the genetic components of asthma, the large and increasing degree of admixture in populations across the world create many challenges

  9. Data management for genomic mapping applications: A case study

    SciTech Connect

    Markowitz, V.M.; Lewis, S.; McCarthy, J.; Olken, F.; Zorn, M.

    1992-05-01

    In this paper we describe a new approach to the construction of data management systems for genomic mapping applications in molecular biology, genetics, and plant breeding. We discuss the architecture of such systems and propose an incremental approach to the development of such systems. We illustrate the proposed approach and architecture with a case study of a prototype data management system for genomic maps.

  10. Connecticut Curriculum Trace Maps: History/Social Studies.

    ERIC Educational Resources Information Center

    Connecticut State Board of Education, Hartford.

    These Connecticut Curriculum Trace Maps are designed to help curriculum developers and teachers translate Connecticut's K-12 history and social studies performance standards into objectives and classroom practice. The Trace Maps provide detailed descriptions of what students should know and be able to do at smaller grade level clusters, K-2, 3-4,…

  11. Mapping Climate Change: Six U.S. Case Studies

    ERIC Educational Resources Information Center

    Holmberg, Marjorie O.

    2010-01-01

    This research focuses on the current role of mapping practices in communicating climate change in the United States. This includes maps used in monitoring climate change, projecting its potential impacts, and identifying potential adaptation strategies at particular scales. Since few, if any, studies have been done specifically on mapping…

  12. Worldwide Patterns of Ancestry, Divergence, and Admixture in Domesticated Cattle

    PubMed Central

    Decker, Jared E.; McKay, Stephanie D.; Rolf, Megan M.; Kim, JaeWoo; Molina Alcalá, Antonio; Sonstegard, Tad S.; Hanotte, Olivier; Götherström, Anders; Seabury, Christopher M.; Praharani, Lisa; Babar, Masroor Ellahi; Correia de Almeida Regitano, Luciana; Yildiz, Mehmet Ali; Heaton, Michael P.; Liu, Wan-Sheng; Lei, Chu-Zhao; Reecy, James M.; Saif-Ur-Rehman, Muhammad; Schnabel, Robert D.; Taylor, Jeremy F.

    2014-01-01

    The domestication and development of cattle has considerably impacted human societies, but the histories of cattle breeds and populations have been poorly understood especially for African, Asian, and American breeds. Using genotypes from 43,043 autosomal single nucleotide polymorphism markers scored in 1,543 animals, we evaluate the population structure of 134 domesticated bovid breeds. Regardless of the analytical method or sample subset, the three major groups of Asian indicine, Eurasian taurine, and African taurine were consistently observed. Patterns of geographic dispersal resulting from co-migration with humans and exportation are recognizable in phylogenetic networks. All analytical methods reveal patterns of hybridization which occurred after divergence. Using 19 breeds, we map the cline of indicine introgression into Africa. We infer that African taurine possess a large portion of wild African auroch ancestry, causing their divergence from Eurasian taurine. We detect exportation patterns in Asia and identify a cline of Eurasian taurine/indicine hybridization in Asia. We also identify the influence of species other than Bos taurus taurus and B. t. indicus in the formation of Asian breeds. We detect the pronounced influence of Shorthorn cattle in the formation of European breeds. Iberian and Italian cattle possess introgression from African taurine. American Criollo cattle originate from Iberia, and not directly from Africa with African ancestry inherited via Iberian ancestors. Indicine introgression into American cattle occurred in the Americas, and not Europe. We argue that cattle migration, movement and trading followed by admixture have been important forces in shaping modern bovine genomic variation. PMID:24675901

  13. Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence.

    PubMed

    Molofsky, Jane; Keller, Stephen R; Lavergne, Sébastien; Kaproth, Matthew A; Eppinga, Maarten B

    2014-04-01

    Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions. PMID:24772269

  14. Human-aided admixture may fuel ecosystem transformation during biological invasions: theoretical and experimental evidence

    PubMed Central

    Molofsky, Jane; Keller, Stephen R; Lavergne, Sébastien; Kaproth, Matthew A; Eppinga, Maarten B

    2014-01-01

    Biological invasions can transform our understanding of how the interplay of historical isolation and contemporary (human-aided) dispersal affects the structure of intraspecific diversity in functional traits, and in turn, how changes in functional traits affect other scales of biological organization such as communities and ecosystems. Because biological invasions frequently involve the admixture of previously isolated lineages as a result of human-aided dispersal, studies of invasive populations can reveal how admixture results in novel genotypes and shifts in functional trait variation within populations. Further, because invasive species can be ecosystem engineers within invaded ecosystems, admixture-induced shifts in the functional traits of invaders can affect the composition of native biodiversity and alter the flow of resources through the system. Thus, invasions represent promising yet under-investigated examples of how the effects of short-term evolutionary changes can cascade across biological scales of diversity. Here, we propose a conceptual framework that admixture between divergent source populations during biological invasions can reorganize the genetic variation underlying key functional traits, leading to shifts in the mean and variance of functional traits within invasive populations. Changes in the mean or variance of key traits can initiate new ecological feedback mechanisms that result in a critical transition from a native ecosystem to a novel invasive ecosystem. We illustrate the application of this framework with reference to a well-studied plant model system in invasion biology and show how a combination of quantitative genetic experiments, functional trait studies, whole ecosystem field studies and modeling can be used to explore the dynamics predicted to trigger these critical transitions. PMID:24772269

  15. Performance Mapping Studies in Redox Flow Cells

    NASA Technical Reports Server (NTRS)

    Hoberecht, M. A.; Thaller, L. H.

    1981-01-01

    Pumping power requirements in any flow battery system constitute a direct parasitic energy loss. It is therefore useful to determine the practical lower limit for reactant flow rates. Through the use of a theoretical framework based on electrochemical first principles, two different experimental flow mapping techniques were developed to evaluate and compare electrodes as a function of flow rate. For the carbon felt electrodes presently used in NASA-Lewis Redox cells, a flow rate 1.5 times greater than the stoichiometric rate seems to be the required minimum.

  16. Protein interaction mapping: A Drosophila case study

    PubMed Central

    Formstecher, Etienne; Aresta, Sandra; Collura, Vincent; Hamburger, Alexandre; Meil, Alain; Trehin, Alexandra; Reverdy, Céline; Betin, Virginie; Maire, Sophie; Brun, Christine; Jacq, Bernard; Arpin, Monique; Bellaiche, Yohanns; Bellusci, Saverio; Benaroch, Philippe; Bornens, Michel; Chanet, Roland; Chavrier, Philippe; Delattre, Olivier; Doye, Valérie; Fehon, Richard; Faye, Gérard; Galli, Thierry; Girault, Jean-Antoine; Goud, Bruno; de Gunzburg, Jean; Johannes, Ludger; Junier, Marie-Pierre; Mirouse, Vincent; Mukherjee, Ashim; Papadopoulo, Dora; Perez, Franck; Plessis, Anne; Rossé, Carine; Saule, Simon; Stoppa-Lyonnet, Dominique; Vincent, Alain; White, Michael; Legrain, Pierre; Wojcik, Jérôme; Camonis, Jacques; Daviet, Laurent

    2005-01-01

    The Drosophila (fruit fly) model system has been instrumental in our current understanding of human biology, development, and diseases. Here, we used a high-throughput yeast two-hybrid (Y2H)-based technology to screen 102 bait proteins from Drosophila melanogaster, most of them orthologous to human cancer-related and/or signaling proteins, against high-complexity fly cDNA libraries. More than 2300 protein-protein interactions (PPI) were identified, of which 710 are of high confidence. The computation of a reliability score for each protein-protein interaction and the systematic identification of the interacting domain combined with a prediction of structural/functional motifs allow the elaboration of known complexes and the identification of new ones. The full data set can be visualized using a graphical Web interface, the PIMRider (http://pim.hybrigenics.com), and is also accessible in the PSI standard Molecular Interaction data format. Our fly Protein Interaction Map (PIM) is surprisingly different from the one recently proposed by Giot et al. with little overlap between the two data sets. Analysis of the differences in data sets and methods suggests alternative strategies to enhance the accuracy and comprehensiveness of the post-genomic generation of broad-scale protein interaction maps. PMID:15710747

  17. Dissecting the genetic structure and admixture of four geographical Malay populations.

    PubMed

    Deng, Lian; Hoh, Boon-Peng; Lu, Dongsheng; Saw, Woei-Yuh; Twee-Hee Ong, Rick; Kasturiratne, Anuradhani; de Silva, H Janaka; Zilfalil, Bin Alwi; Kato, Norihiro; Wickremasinghe, Ananda R; Teo, Yik-Ying; Xu, Shuhua

    2015-01-01

    The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austronesian (17%-62%), Proto-Malay (15%-31%), East Asian (4%-16%) and South Asian (3%-34%). Approximately 34% of the genetic makeup of SLM is of South Asian ancestry, resulting in its distinct genetic pattern compared with the other three Malay populations. Besides, substantial differentiation was observed between the Malay populations from the north and the south, and between those from the west and the east. In summary, this study revealed that the genetic identity of the Malays comprises a mixed entity of multiple ancestries represented by Austronesian, Proto-Malay, East Asian and South Asian, with most of the admixture events estimated to have occurred 175 to 1,500 years ago, which in turn suggests that geographical isolation and independent admixture have significantly shaped the genetic architectures and the diversity of the Malay populations. PMID:26395220

  18. Dissecting the genetic structure and admixture of four geographical Malay populations

    PubMed Central

    Deng, Lian; Hoh, Boon-Peng; Lu, Dongsheng; Saw, Woei-Yuh; Twee-Hee Ong, Rick; Kasturiratne, Anuradhani; Janaka de Silva, H.; Zilfalil, Bin Alwi; Kato, Norihiro; Wickremasinghe, Ananda R.; Teo, Yik-Ying; Xu, Shuhua

    2015-01-01

    The Malay people are an important ethnic composition in Southeast Asia, but their genetic make-up and population structure remain poorly studied. Here we conducted a genome-wide study of four geographical Malay populations: Peninsular Malaysian Malay (PMM), Singaporean Malay (SGM), Indonesian Malay (IDM) and Sri Lankan Malay (SLM). All the four Malay populations showed substantial admixture with multiple ancestries. We identified four major ancestral components in Malay populations: Austronesian (17%–62%), Proto-Malay (15%–31%), East Asian (4%–16%) and South Asian (3%–34%). Approximately 34% of the genetic makeup of SLM is of South Asian ancestry, resulting in its distinct genetic pattern compared with the other three Malay populations. Besides, substantial differentiation was observed between the Malay populations from the north and the south, and between those from the west and the east. In summary, this study revealed that the genetic identity of the Malays comprises a mixed entity of multiple ancestries represented by Austronesian, Proto-Malay, East Asian and South Asian, with most of the admixture events estimated to have occurred 175 to 1,500 years ago, which in turn suggests that geographical isolation and independent admixture have significantly shaped the genetic architectures and the diversity of the Malay populations. PMID:26395220

  19. Testing for Ancient Admixture between Closely Related Populations

    PubMed Central

    Durand, Eric Y.; Patterson, Nick; Reich, David; Slatkin, Montgomery

    2011-01-01

    One enduring question in evolutionary biology is the extent of archaic admixture in the genomes of present-day populations. In this paper, we present a test for ancient admixture that exploits the asymmetry in the frequencies of the two nonconcordant gene trees in a three-population tree. This test was first applied to detect interbreeding between Neandertals and modern humans. We derive the analytic expectation of a test statistic, called the D statistic, which is sensitive to asymmetry under alternative demographic scenarios. We show that the D statistic is insensitive to some demographic assumptions such as ancestral population sizes and requires only the assumption that the ancestral populations were randomly mating. An important aspect of D statistics is that they can be used to detect archaic admixture even when no archaic sample is available. We explore the effect of sequencing error on the false-positive rate of the test for admixture, and we show how to estimate the proportion of archaic ancestry in the genomes of present-day populations. We also investigate a model of subdivision in ancestral populations that can result in D statistics that indicate recent admixture. PMID:21325092

  20. Uncontrolled admixture and loss of genetic diversity in a local Vietnamese pig breed

    PubMed Central

    Berthouly-Salazar, Cécile; Thévenon, Sophie; Van, Thu Nhu; Nguyen, Binh Trong; Pham, Lan Doan; Chi, Cuong Vu; Maillard, Jean-Charles

    2012-01-01

    The expansion of intensive livestock production systems in developing countries has increased the introduction of highly productive exotic breeds facilitating indiscriminate crossbreeding with local breeds. In this study, we set out to investigate the genetic status of the Vietnamese Black H’mong pig breed by evaluating (1) genetic diversity and (2) introgression from exotic breeds. Two exotic breeds, namely Landrace and Yorkshire used for crossbreeding, and the H’mong pig population from Ha Giang (HG) province were investigated using microsatellite markers. Within the province, three phenotypes were observed: a White, a Spotted and a Black phenotype. Genetic differentiation between phenotypes was low (0.5–6.1%). The White phenotypes showed intermediate admixture values between exotic breeds and the Black HG population (0.53), indicating a crossbreed status. Management practices were used to predict the rate of private diversity loss due to exotic gene introgressions. After 60 generations, 100% of Black private alleles will be lost. This loss is accelerated if the admixture rate is increased but can be slowed down if the mortality rate (e.g., recruitment rate) is decreased. Our study showed that a large number of markers are needed for accurately identifying hybrid classes for closely related populations. While our estimate of admixture still seems underestimated, genetic erosion can occur very fast even through indiscriminate crossbreeding. PMID:22837841

  1. Strong Selection at MHC in Mexicans since Admixture

    PubMed Central

    Zhou, Quan; Zhao, Liang; Guan, Yongtao

    2016-01-01

    Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest of the genome, which is the hallmark of recent selection for admixed samples. The estimated selection coefficients are 0.05 and 0.07 for two datasets, which put our finding among the strongest known selections observed in humans, namely, lactase selection in northern Europeans and sickle-cell trait in Africans. Using inaccurate Amerindian training samples was a major concern for the credibility of previously reported selection signals in Latinos. Taking advantage of the flexibility of our statistical model, we devised a model fitting technique that can learn Amerindian ancestral haplotype from the admixed samples, which allows us to infer local ancestries for Mexicans using only European and African training samples. The strong selection signal at the MHC remains without Amerindian training samples. Finally, we note that medical history studies suggest such a strong selection at MHC is plausible in Mexicans. PMID:26863142

  2. Strong Selection at MHC in Mexicans since Admixture.

    PubMed

    Zhou, Quan; Zhao, Liang; Guan, Yongtao

    2016-02-01

    Mexicans are a recent admixture of Amerindians, Europeans, and Africans. We performed local ancestry analysis of Mexican samples from two genome-wide association studies obtained from dbGaP, and discovered that at the MHC region Mexicans have excessive African ancestral alleles compared to the rest of the genome, which is the hallmark of recent selection for admixed samples. The estimated selection coefficients are 0.05 and 0.07 for two datasets, which put our finding among the strongest known selections observed in humans, namely, lactase selection in northern Europeans and sickle-cell trait in Africans. Using inaccurate Amerindian training samples was a major concern for the credibility of previously reported selection signals in Latinos. Taking advantage of the flexibility of our statistical model, we devised a model fitting technique that can learn Amerindian ancestral haplotype from the admixed samples, which allows us to infer local ancestries for Mexicans using only European and African training samples. The strong selection signal at the MHC remains without Amerindian training samples. Finally, we note that medical history studies suggest such a strong selection at MHC is plausible in Mexicans. PMID:26863142

  3. Intraspecific Genetic Admixture and the Morphological Diversification of an Estuarine Fish Population Complex

    PubMed Central

    Legault, Michel

    2015-01-01

    The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of the estuarine rainbow smelt population complex. The morphology of mixed-ancestry populations varied as a function of the relative contribution of the two races to estuarine populations, supporting the hypothesis of genetic admixture. Populations comprising both ancestral mtDNA races did not exhibit intermediate morphologies relative to pure populations but rather exhibited many traits that exceeded the parental trait values, consistent with the hypothesis of transgressive segregation. Evidence for genetic admixture at the level of the nuclear gene pool, however, provided only partial support for this hypothesis. Variation at nuclear AFLP markers revealed clear evidence of the two corresponding mtDNA glacial races. The admixture of the two races at the nuclear level is only pronounced in mixed-ancestry populations dominated by one of the mtDNA lineages, the same populations showing the greatest degree of morphological diversification and population structure. In contrast, mixed-ancestry populations dominated by the alternate mtDNA lineage showed little evidence of introgression of the nuclear genome, little morphological diversification and little contemporary population genetic structure. These results only partially support the hypothesis of transgressive segregation and may be the result of the differential effects of natural selection acting on admixed genomes from different sources. PMID:25856193

  4. Intraspecific genetic admixture and the morphological diversification of an estuarine fish population complex.

    PubMed

    Dodson, Julian J; Bourret, Audrey; Barrette, Marie France; Turgeon, Julie; Daigle, Gaétan; Legault, Michel; Lecomte, Frédéric

    2015-01-01

    The North-east American Rainbow smelt (Osmerus mordax) is composed of two glacial races first identified through the spatial distribution of two distinct mtDNA lineages. Contemporary breeding populations of smelt in the St. Lawrence estuary comprise contrasting mixtures of both lineages, suggesting that the two races came into secondary contact in this estuary. The overall objective of this study was to assess the role of intraspecific genetic admixture in the morphological diversification of the estuarine rainbow smelt population complex. The morphology of mixed-ancestry populations varied as a function of the relative contribution of the two races to estuarine populations, supporting the hypothesis of genetic admixture. Populations comprising both ancestral mtDNA races did not exhibit intermediate morphologies relative to pure populations but rather exhibited many traits that exceeded the parental trait values, consistent with the hypothesis of transgressive segregation. Evidence for genetic admixture at the level of the nuclear gene pool, however, provided only partial support for this hypothesis. Variation at nuclear AFLP markers revealed clear evidence of the two corresponding mtDNA glacial races. The admixture of the two races at the nuclear level is only pronounced in mixed-ancestry populations dominated by one of the mtDNA lineages, the same populations showing the greatest degree of morphological diversification and population structure. In contrast, mixed-ancestry populations dominated by the alternate mtDNA lineage showed little evidence of introgression of the nuclear genome, little morphological diversification and little contemporary population genetic structure. These results only partially support the hypothesis of transgressive segregation and may be the result of the differential effects of natural selection acting on admixed genomes from different sources. PMID:25856193

  5. Tracing the origin of the east-west population admixture in the Altai region (Central Asia).

    PubMed

    González-Ruiz, Mercedes; Santos, Cristina; Jordana, Xavier; Simón, Marc; Lalueza-Fox, Carles; Gigli, Elena; Aluja, Maria Pilar; Malgosa, Assumpció

    2012-01-01

    A recent discovery of Iron Age burials (Pazyryk culture) in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected. However, the underlying events behind the genetic admixture in Altai during the Iron Age are still unresolved: 1) whether it was a result of migratory events (eastward firstly, westward secondly), or 2) whether it was a result of a local demographic expansion in a 'contact zone' between European and East Asian people. In the present work, we analyzed the mitochondrial DNA lineages in human remains from Bronze and Iron Age burials of Mongolian Altai. Here we present support to the hypothesis that the gene pool of Iron Age inhabitants of Mongolian Altai was similar to that of western Iron Age Altaians (Russia and Kazakhstan). Thus, this people not only shared the same culture (Pazyryk), but also shared the same genetic east-west population admixture. In turn, Pazyryks appear to have a similar gene pool that current Altaians. Our results further show that Iron Age Altaians displayed mitochondrial lineages already present around Altai region before the Iron Age. This would provide support for a demographic expansion of local people of Altai instead of westward or eastward migratory events, as the demographic event behind the high population genetic admixture and diversity in Central Asia. PMID:23152818

  6. Tracing the Origin of the East-West Population Admixture in the Altai Region (Central Asia)

    PubMed Central

    González-Ruiz, Mercedes; Santos, Cristina; Jordana, Xavier; Simón, Marc; Lalueza-Fox, Carles; Gigli, Elena; Aluja, Maria Pilar; Malgosa, Assumpció

    2012-01-01

    A recent discovery of Iron Age burials (Pazyryk culture) in the Altai Mountains of Mongolia may shed light on the mode and tempo of the generation of the current genetic east-west population admixture in Central Asia. Studies on ancient mitochondrial DNA of this region suggest that the Altai Mountains played the role of a geographical barrier between West and East Eurasian lineages until the beginning of the Iron Age. After the 7th century BC, coinciding with Scythian expansion across the Eurasian steppes, a gradual influx of East Eurasian sequences in Western steppes is detected. However, the underlying events behind the genetic admixture in Altai during the Iron Age are still unresolved: 1) whether it was a result of migratory events (eastward firstly, westward secondly), or 2) whether it was a result of a local demographic expansion in a ‘contact zone’ between European and East Asian people. In the present work, we analyzed the mitochondrial DNA lineages in human remains from Bronze and Iron Age burials of Mongolian Altai. Here we present support to the hypothesis that the gene pool of Iron Age inhabitants of Mongolian Altai was similar to that of western Iron Age Altaians (Russia and Kazakhstan). Thus, this people not only shared the same culture (Pazyryk), but also shared the same genetic east-west population admixture. In turn, Pazyryks appear to have a similar gene pool that current Altaians. Our results further show that Iron Age Altaians displayed mitochondrial lineages already present around Altai region before the Iron Age. This would provide support for a demographic expansion of local people of Altai instead of westward or eastward migratory events, as the demographic event behind the high population genetic admixture and diversity in Central Asia. PMID:23152818

  7. Chemical stability of an admixture combining ziconotide and bupivacaine during simulated intrathecal administration.

    PubMed

    Shields, David; Montenegro, Rick; Aclan, Jennifer

    2007-10-01

    Objective.  To determine the stability of an admixture combining ziconotide with bupivacaine hydrochloride during simulated intrathecal infusion under laboratory conditions at 37°. Materials and Methods.  An admixture containing ziconotide (25 µg/mL) and bupivacaine hydrochloride (5 mg/mL) was stored in SynchroMed® II pumps at 37° and in control vials at either 37° or 5°. Using high-performance liquid chromatography, drug concentrations were determined from samples obtained at varying intervals during the 30-day study. Results.  After 30 days, pump ziconotide and bupivacaine hydrochloride concentrations measured an average of 86.9% and 99.4% of their initial concentrations, respectively. Control vials displayed similar degradation rates for both drugs. Statistical evaluation of the ziconotide 95% confidence interval indicated that the ziconotide concentration would meet or exceed 90% and 80% of initial concentration for 22 days and 45 days, respectively. Conclusions.  An admixture containing 25 µg/mL ziconotide and 5 mg/mL bupivacaine hydrochloride was 90% stable for 22 days and 80% stable for 45 days (extrapolated) in SynchroMed® II infusion pumps. PMID:22150945

  8. Effect of chemical admixtures on properties of high-calcium fly ash geopolymer

    NASA Astrophysics Data System (ADS)

    Rattanasak, Ubolluk; Pankhet, Kanokwan; Chindaprasirt, Prinya

    2011-06-01

    Owing to the high viscosity of sodium silicate solution, fly ash geopolymer has the problems of low workability and rapid setting time. Therefore, the effect of chemical admixtures on the properties of fly ash geopolymer was studied to overcome the rapid set of the geopolymer in this paper. High-calcium fly ash and alkaline solution were used as starting materials to synthesize the geopolymer. Calcium chloride, calcium sulfate, sodium sulfate, and sucrose at dosages of 1wt% and 2wt% of fly ash were selected as admixtures based on concrete knowledge to improve the properties of the geopolymer. The setting time, compressive strength, and degree of reaction were recorded, and the microstructure was examined. The results show that calcium chloride significantly shortens both the initial and final setting times of the geopolymer paste. In addition, sucrose also delays the final setting time significantly. The degrees of reaction of fly ash in the geopolymer paste with the admixtures are all higher than those of the control paste. This contributes to the obvious increases in compressive strength.

  9. Testing models of speciation from genome sequences: divergence and asymmetric admixture in Island South-East Asian Sus species during the Plio-Pleistocene climatic fluctuations.

    PubMed

    Frantz, Laurent A F; Madsen, Ole; Megens, Hendrik-Jan; Groenen, Martien A M; Lohse, Konrad

    2014-11-01

    In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here, we investigate this issue using genome sequences of three pig (Sus) species, two of which are found on islands of the Sunda-shelf shallow seas in Island South-East Asia (ISEA). A previous study revealed signatures of interspecific admixture between these Sus species (Genome biology, 14, 2013, R107). However, the timing, directionality and extent of this admixture remain unknown. Here, we use a likelihood-based model comparison to more finely resolve this admixture history and test whether it was mediated by humans or occurred naturally. Our analyses suggest that interspecific admixture between Sunda-shelf species was most likely asymmetric and occurred long before the arrival of humans in the region. More precisely, we show that these species diverged during the late Pliocene but around 23% of their genomes have been affected by admixture during the later Pleistocene climatic transition. In addition, we show that our method provides a significant improvement over D-statistics which are uninformative about the direction of admixture. PMID:25294645

  10. Testing models of speciation from genome sequences: divergence and asymmetric admixture in Island South-East Asian Sus species during the Plio-Pleistocene climatic fluctuations

    PubMed Central

    Frantz, Laurent A F; Madsen, Ole; Megens, Hendrik-Jan; Groenen, Martien A M; Lohse, Konrad

    2014-01-01

    In many temperate regions, ice ages promoted range contractions into refugia resulting in divergence (and potentially speciation), while warmer periods led to range expansions and hybridization. However, the impact these climatic oscillations had in many parts of the tropics remains elusive. Here, we investigate this issue using genome sequences of three pig (Sus) species, two of which are found on islands of the Sunda-shelf shallow seas in Island South-East Asia (ISEA). A previous study revealed signatures of interspecific admixture between these Sus species (Genome biology,14, 2013, R107). However, the timing, directionality and extent of this admixture remain unknown. Here, we use a likelihood-based model comparison to more finely resolve this admixture history and test whether it was mediated by humans or occurred naturally. Our analyses suggest that interspecific admixture between Sunda-shelf species was most likely asymmetric and occurred long before the arrival of humans in the region. More precisely, we show that these species diverged during the late Pliocene but around 23% of their genomes have been affected by admixture during the later Pleistocene climatic transition. In addition, we show that our method provides a significant improvement over D-statistics which are uninformative about the direction of admixture. PMID:25294645

  11. Admixture into and within sub-Saharan Africa

    PubMed Central

    Busby, George BJ; Band, Gavin; Si Le, Quang; Jallow, Muminatou; Bougama, Edith; Mangano, Valentina D; Amenga-Etego, Lucas N; Enimil, Anthony; Apinjoh, Tobias; Ndila, Carolyne M; Manjurano, Alphaxard; Nyirongo, Vysaul; Doumba, Ogobara; Rockett, Kirk A; Kwiatkowski, Dominic P; Spencer, Chris CA

    2016-01-01

    Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology. DOI: http://dx.doi.org/10.7554/eLife.15266.001 PMID:27324836

  12. A slide-rule for assessment of venous admixture.

    PubMed

    Zetterström, H

    1989-04-01

    Determination of venous admixture (physiological shunt, Qva/Qt) requires analysis of both arterial and mixed venous blood. When a pulmonary arterial catheter is not in use, the pulmonary oxygenating capacity may be assessed from arterial blood gas data, the fraction of inspired oxygen (FIO2) and an assumed value of the arterial-mixed venous oxygen content difference. To facilitate this process, a slide-rule based on the "virtual shunt" concept is presented. It permits rapid assessment of Qva/Qt from known values of arterial oxygen tension (PaO2) or saturation (SaO2) and FIO2 and may promote the choice of appropriate FIO2. The limitations of the slide-rule were studied theoretically and its validity was tested by comparing 100 determinations of virtual shunt with the corresponding Qva/Qt values. The slide-rule was found to estimate Qva/Qt more accurately than commonly used oxygenation indices such as the PaO2/FIO2 ratio. PMID:2499154

  13. Admixture into and within sub-Saharan Africa.

    PubMed

    Busby, George Bj; Band, Gavin; Si Le, Quang; Jallow, Muminatou; Bougama, Edith; Mangano, Valentina D; Amenga-Etego, Lucas N; Enimil, Anthony; Apinjoh, Tobias; Ndila, Carolyne M; Manjurano, Alphaxard; Nyirongo, Vysaul; Doumba, Ogobara; Rockett, Kirk A; Kwiatkowski, Dominic P; Spencer, Chris Ca

    2016-01-01

    Similarity between two individuals in the combination of genetic markers along their chromosomes indicates shared ancestry and can be used to identify historical connections between different population groups due to admixture. We use a genome-wide, haplotype-based, analysis to characterise the structure of genetic diversity and gene-flow in a collection of 48 sub-Saharan African groups. We show that coastal populations experienced an influx of Eurasian haplotypes over the last 7000 years, and that Eastern and Southern Niger-Congo speaking groups share ancestry with Central West Africans as a result of recent population expansions. In fact, most sub-Saharan populations share ancestry with groups from outside of their current geographic region as a result of gene-flow within the last 4000 years. Our in-depth analysis provides insight into haplotype sharing across different ethno-linguistic groups and the recent movement of alleles into new environments, both of which are relevant to studies of genetic epidemiology. PMID:27324836

  14. Optical Properties of TGS Crystal with L-Valine Admixture

    SciTech Connect

    Stadnyk, V. Yo. Romanyuk, N. A.; Kiryk, Yu. I.

    2010-11-15

    The thermal expansion and temperature and the spectral dependences of the refractive indices and birefringence of triglycine sulphate (TGS) crystals with a 5% L-valine admixture have been investigated. It is established that the introduction of L-valine weakens the temperature dependence of the refractive indices and the birefringence and thermal expansion of TGS crystals. The parameters of the Sellmeier formula, refractions, and electronic polarizabilities are calculated. The changes observed may be related to the increase in hardness of admixture-containing crystals, the decrease in the spontaneous polarization, the replacement of the refraction components of the valine bond, or the spontaneous electro-optic effect.

  15. Optical Properties of TGS Crystal with L-Valine Admixture

    NASA Astrophysics Data System (ADS)

    Stadnyk, V. Yo.; Romanyuk, N. A.; Kiryk, Yu. I.

    2010-11-01

    The thermal expansion and temperature and the spectral dependences of the refractive indices and birefringence of triglycine sulphate (TGS) crystals with a 5% L-valine admixture have been investigated. It is established that the introduction of L-valine weakens the temperature dependence of the refractive indices and the birefringence and thermal expansion of TGS crystals. The parameters of the Sellmeier formula, refractions, and electronic polarizabilities are calculated. The changes observed may be related to the increase in hardness of admixture-containing crystals, the decrease in the spontaneous polarization, the replacement of the refraction components of the valine bond, or the spontaneous electro-optic effect.

  16. Fine-Mapping in African Americans of Eight Recently Discovered Genetic Loci for Plasma Lipids: The Jackson Heart Study

    PubMed Central

    Keebler, Mary E.; Deo, Rahul C.; Surti, Aarti; Konieczkowski, David; Guiducci, Candace; Burtt, Noel; Buxbaum, Sarah G.; Sarpong, Daniel F.; Steffes, Michael W.; Wilson, James G.; Taylor, Herman A.; Kathiresan, Sekar

    2011-01-01

    Background Genome-wide association studies in cohorts of European descent have identified novel genomic regions as associated with lipids, but their relevance in African Americans remains unclear. Methods and Results We genotyped 8 index SNPs and 488 tagging SNPs across 8 novel lipid loci in the Jackson Heart Study, a community-based cohort of 4605 African Americans. For each trait, we calculated residuals adjusted for age, sex, and global ancestry and performed multivariable linear regression to detect genotype-phenotype association with adjustment for local ancestry. To explore admixture effects, we conducted stratified analyses in individuals with a high probability of 2 African ancestral alleles or at least 1 European allele at each locus. We confirmed 2 index SNPs as associated with lipid traits in African Americans, with suggestive association for 3 more. However, the effect sizes for 4 of the 5 associated SNPs were larger in the European local ancestry subgroup compared to the African local ancestry subgroup, suggesting that the replication is driven by European ancestry segments. Through fine-mapping, we discovered 3 new SNPs with significant associations, two with consistent effect on triglyceride levels across ancestral groups: rs636523 near DOCK7/ANGPTL3 and rs780093 in GCKR. African LD patterns did not assist in narrowing association signals. Conclusions We confirm that 5 genetic regions associated with lipid traits in European-derived populations are relevant in African Americans. To further evaluate these loci, fine-mapping in larger African American cohorts and/or resequencing will be required. PMID:20570916

  17. Length Distribution of Ancestral Tracks under a General Admixture Model and Its Applications in Population History Inference

    PubMed Central

    Ni, Xumin; Yang, Xiong; Guo, Wei; Yuan, Kai; Zhou, Ying; Ma, Zhiming; Xu, Shuhua

    2016-01-01

    The length of ancestral tracks decays with the passing of generations which can be used to infer population admixture histories. Previous studies have shown the power in recovering the histories of admixed populations via the length distributions of ancestral tracks even under simple models. We believe that the deduction of length distributions under a general model will greatly elevate the power. Here we first deduced the length distributions under a general model and proposed general principles in parameter estimation and model selection with the deduced length distributions. Next, we focused on studying the length distributions and its applications under three typical special cases. Extensive simulations showed that the length distributions of ancestral tracks were well predicted by our theoretical framework. We further developed a new method, AdmixInfer, based on the length distributions and good performance was observed when it was applied to infer population histories under the three typical models. Notably, our method was insensitive to demographic history, sample size and threshold to discard short tracks. Finally, good performance was also observed when applied to some real datasets of African Americans, Mexicans and South Asian populations from the HapMap project and the Human Genome Diversity Project. PMID:26818889

  18. Implications of the admixture process in skin color molecular assessment.

    PubMed

    Cerqueira, Caio Cesar Silva de; Hünemeier, Tábita; Gomez-Valdés, Jorge; Ramallo, Virgínia; Volasko-Krause, Carla Daiana; Barbosa, Ana Angélica Leal; Vargas-Pinilla, Pedro; Dornelles, Rodrigo Ciconet; Longo, Danaê; Rothhammer, Francisco; Bedoya, Gabriel; Canizales-Quinteros, Samuel; Acuña-Alonzo, Victor; Gallo, Carla; Poletti, Giovanni; González-José, Rolando; Salzano, Francisco Mauro; Callegari-Jacques, Sídia Maria; Schuler-Faccini, Lavínia; Ruiz-Linares, Andrés; Cátira Bortolini, Maria

    2014-01-01

    The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N = 352; Baiano, N = 148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice. PMID:24809478

  19. Implications of the Admixture Process in Skin Color Molecular Assessment

    PubMed Central

    de Cerqueira, Caio Cesar Silva; Hünemeier, Tábita; Gomez-Valdés, Jorge; Ramallo, Virgínia; Volasko-Krause, Carla Daiana; Barbosa, Ana Angélica Leal; Vargas-Pinilla, Pedro; Dornelles, Rodrigo Ciconet; Longo, Danaê; Rothhammer, Francisco; Bedoya, Gabriel; Canizales-Quinteros, Samuel; Acuña-Alonzo, Victor; Gallo, Carla; Poletti, Giovanni; González-José, Rolando; Salzano, Francisco Mauro; Callegari-Jacques, Sídia Maria; Schuler-Faccini, Lavínia; Ruiz-Linares, Andrés; Cátira Bortolini, Maria

    2014-01-01

    The understanding of the complex genotype-phenotype architecture of human pigmentation has clear implications for the evolutionary history of humans, as well as for medical and forensic practices. Although dozens of genes have previously been associated with human skin color, knowledge about this trait remains incomplete. In particular, studies focusing on populations outside the European-North American axis are rare, and, until now, admixed populations have seldom been considered. The present study was designed to help fill this gap. Our objective was to evaluate possible associations of 18 single nucleotide polymorphisms (SNPs), located within nine genes, and one pseudogene with the Melanin Index (MI) in two admixed Brazilian populations (Gaucho, N = 352; Baiano, N = 148) with different histories of geographic and ethnic colonization. Of the total sample, four markers were found to be significantly associated with skin color, but only two (SLC24A5 rs1426654, and SLC45A2 rs16891982) were consistently associated with MI in both samples (Gaucho and Baiano). Therefore, only these 2 SNPs should be preliminarily considered to have forensic significance because they consistently showed the association independently of the admixture level of the populations studied. We do not discard that the other two markers (HERC2 rs1129038 and TYR rs1126809) might be also relevant to admixed samples, but additional studies are necessary to confirm the real importance of these markers for skin pigmentation. Finally, our study shows associations of some SNPs with MI in a modern Brazilian admixed sample, with possible applications in forensic genetics. Some classical genetic markers in Euro-North American populations are not associated with MI in our sample. Our results point out the relevance of considering population differences in selecting an appropriate set of SNPs as phenotype predictors in forensic practice. PMID:24809478

  20. Gamification in Education: A Systematic Mapping Study

    ERIC Educational Resources Information Center

    Dicheva, Darina; Dichev, Christo; Agre, Gennady; Angelova, Galia

    2015-01-01

    While gamification is gaining ground in business, marketing, corporate management, and wellness initiatives, its application in education is still an emerging trend. This article presents a study of the published empirical research on the application of gamification to education. The study is limited to papers that discuss explicitly the effects…

  1. Multi Rotor Uav at Different Altitudes for Slope Mapping Studies

    NASA Astrophysics Data System (ADS)

    Tahar, K. N.

    2015-08-01

    Most of consultation work only involves a small area, especially for slope mapping studies. The objective of this study is to evaluate the accuracy of slope mapping results from different altitudes at semi-undulated area and undulated area. Multi-rotor UAV is used as an instrument for data acquisition for this study. The images of slope were captured from five different altitudes in the same study area. All images were processed using photogrammetric software to produce digital elevation models and digital orthophoto. In this study, slope map from all different altitudes were identified and recorded for analysis purposes. It was found that the accuracy of slope is increase when altitude is increase. In conclusion, the condition of slope such as semi-undulated and undulated area did have an influence on the slope accuracy.

  2. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    SciTech Connect

    Robert F. Rathbone; Thomas L. Robl

    2001-10-11

    Work completed in this reporting period focused on the measurement of the rate of ammonia loss from mortar and concrete, and the measurement of ammonia gas in the air above the materials immediately after placement. The majority of mortar experiments have been completed, and testing has begun on concrete. The mortar experiments indicate that the rate of ammonia loss is greater in mortars prepared using a higher water content and water:cement (W:C) ratio, although the higher rate is primarily observed within the first 2 days, after which the loss rates are nearly the same. The source of low-calcium (Class F) fly ash exerted a negligible influence on the loss rate. However, mortar prepared using a higher-calcium fly ash evolved ammonia at a slightly slower rate than the Class F ash mortars. The data also indicate that an increase in ventilation increases the ammonia loss rate from mortar, and suggest that a well-ventilated space could substantially increase the loss of ammonia from mortar and, by inference, a concrete slab. Analysis of ammonia concentrations in the air above freshly-placed mortars in an enclosed space indicate that the fly ash ammonia concentration should not exceed 100 mg N/kg ash in confined space applications. For most other applications with some ventilation the maximum acceptable concentration would be approximately 200 mg/kg. Early results from experiments on concrete suggest that, under similar conditions, ammonia diffusion from concrete occurs at a higher rate than in mortar. In addition, increasing the slump of concrete through the use of chemical admixtures has only a minor effect on the ammonia loss rate.

  3. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    SciTech Connect

    Robert F. Rathbone; Thomas L. Robl

    2001-04-11

    Work completed in this reporting period focused on finalization of the Work and Management Plan, sample acquisition and analysis, evaluation of ammonia measurement methods, and measurement of ammonia loss from mortar. All fly ash samples have been acquired and analyzed for chemical composition and particle fineness. Three non-ammoniated fly ash samples were obtained from power plants that do not inject ammonia for NOx or particulate control, while three ammoniated fly ashes originate from plants that inject ammonia into the flue gas. The fly ash sources were selected based on their marketability as concrete admixtures and ammonia content. Coarse and fine aggregates for mortar and concrete testing have also been secured and have been thoroughly characterized using ASTM methods. Methodologies for the measurement of ammonia in the gaseous and aqueous phase have been carefully considered in the context of their suitability for use in this project. These include ammonia detection tubes, carbon impregnated with sulfuric acid (CISA) tubes, titration, and electrochemical methods. It was concluded that each of these methods is potentially useful for different aspects of the project, depending on the phase and concentration of ammonia to be measured. Preparation of fly ash-containing mortars both with and without ammonia indicated that the ammonia has no significant influence on compressive strength. Finally, measurement of ammonia loss from mortar has begun and the results of several of these experiments are included herein. It has been found that, under the laboratory curing conditions devised, ammonia release from mortar occurs at a relatively rapid rate in the first 24 hours, proceeded by a much slower, essentially linear rate. Furthermore, at the end of the three-week experiments, it was calculated that greater than 80% of the initial ammonia concentration remained within the mortar.

  4. Secondary contact and admixture between independently invading populations of the western corn rootworm, Diabrotica virgifera virgifera in Europe.

    PubMed

    Bermond, Gérald; Ciosi, Marc; Lombaert, Eric; Blin, Aurélie; Boriani, Marco; Furlan, Lorenzo; Toepfer, Stefan; Guillemaud, Thomas

    2012-01-01

    The western corn rootworm, Diabrotica virgifera virgifera (Coleoptera: Chrysomelidae), is one of the most destructive pests of corn in North America and is currently invading Europe. The two major invasive outbreaks of rootworm in Europe have occurred, in North-West Italy and in Central and South-Eastern Europe. These two outbreaks originated from independent introductions from North America. Secondary contact probably occurred in North Italy between these two outbreaks, in 2008. We used 13 microsatellite markers to conduct a population genetics study, to demonstrate that this geographic contact resulted in a zone of admixture in the Italian region of Veneto. We show that i) genetic variation is greater in the contact zone than in the parental outbreaks; ii) several signs of admixture were detected in some Venetian samples, in a bayesian analysis of the population structure and in an approximate bayesian computation analysis of historical scenarios and, finally, iii) allelic frequency clines were observed at microsatellite loci. The contact between the invasive outbreaks in North-West Italy and Central and South-Eastern Europe resulted in a zone of admixture, with particular characteristics. The evolutionary implications of the existence of a zone of admixture in Northern Italy and their possible impact on the invasion success of the western corn rootworm are discussed. PMID:23189184

  5. Admixture and Genetic Diversity Distribution Patterns of Non-Recombining Lineages of Native American Ancestry in Colombian Populations

    PubMed Central

    Xavier, Catarina; Builes, Juan José; Gomes, Verónica; Ospino, Jose Miguel; Aquino, Juliana; Parson, Walther; Amorim, António; Gusmão, Leonor; Goios, Ana

    2015-01-01

    Genetic diversity of present American populations results from very complex demographic events involving different types and degrees of admixture. Through the analysis of lineage markers such as mtDNA and Y chromosome it is possible to recover the original Native American haplotypes, which remained identical since the admixture events due to the absence of recombination. However, the decrease in the effective population sizes and the consequent genetic drift effects suffered by these populations during the European colonization resulted in the loss or under-representation of a substantial fraction of the Native American lineages. In this study, we aim to clarify how the diversity and distribution of uniparental lineages vary with the different demographic characteristics (size, degree of isolation) and the different levels of admixture of extant Native groups in Colombia. We present new data resulting from the analyses of mtDNA whole control region, Y chromosome SNP haplogroups and STR haplotypes, and autosomal ancestry informative insertion-deletion polymorphisms in Colombian individuals from different ethnic and linguistic groups. The results demonstrate that populations presenting a high proportion of non-Native American ancestry have preserved nevertheless a substantial diversity of Native American lineages, for both mtDNA and Y chromosome. We suggest that, by maintaining the effective population sizes high, admixture allowed for a decrease in the effects of genetic drift due to Native population size reduction and thus resulting in an effective preservation of the Native American non-recombining lineages. PMID:25775361

  6. Multilocus Bayesian Estimates of Intra-Oceanic Genetic Differentiation, Connectivity, and Admixture in Atlantic Swordfish (Xiphias gladius L.)

    PubMed Central

    Smith, Brad L.; Lu, Ching-Ping; García-Cortés, Blanca; Viñas, Jordi; Yeh, Shean-Ya; Alvarado Bremer, Jaime R.

    2015-01-01

    Previous genetic studies of Atlantic swordfish (Xiphias gladius L.) revealed significant differentiation among Mediterranean, North Atlantic and South Atlantic populations using both mitochondrial and nuclear DNA data. However, limitations in geographic sampling coverage, and the use of single loci, precluded an accurate placement of boundaries and of estimates of admixture. In this study, we present multilocus analyses of 26 single nucleotide polymorphisms (SNPs) within 10 nuclear genes to estimate population differentiation and admixture based on the characterization of 774 individuals representing North Atlantic, South Atlantic, and Mediterranean swordfish populations. Pairwise FST values, AMOVA, PCoA, and Bayesian individual assignments support the differentiation of swordfish inhabiting these three basins, but not the current placement of the boundaries that separate them. Specifically, the range of the South Atlantic population extends beyond 5°N management boundary to 20°N-25°N from 45°W. Likewise the Mediterranean population extends beyond the current management boundary at the Strait of Gibraltar to approximately 10°W. Further, admixture zones, characterized by asymmetric contributions of adjacent populations within samples, are confined to the Northeast Atlantic. While South Atlantic and Mediterranean migrants were identified within these Northeast Atlantic admixture zones no North Atlantic migrants were identified respectively in these two neighboring basins. Owing to both, the characterization of larger number of loci and a more ample spatial sampling coverage, it was possible to provide a finer resolution of the boundaries separating Atlantic swordfish populations than previous studies. Finally, the patterns of population structure and admixture are discussed in the light of the reproductive biology, the known patterns of dispersal, and oceanographic features that may act as barriers to gene flow to Atlantic swordfish. PMID:26057382

  7. Coordinated Optimization of Visual Cortical Maps (II) Numerical Studies

    PubMed Central

    Reichl, Lars; Heide, Dominik; Löwel, Siegrid; Crowley, Justin C.; Kaschube, Matthias; Wolf, Fred

    2012-01-01

    In the juvenile brain, the synaptic architecture of the visual cortex remains in a state of flux for months after the natural onset of vision and the initial emergence of feature selectivity in visual cortical neurons. It is an attractive hypothesis that visual cortical architecture is shaped during this extended period of juvenile plasticity by the coordinated optimization of multiple visual cortical maps such as orientation preference (OP), ocular dominance (OD), spatial frequency, or direction preference. In part (I) of this study we introduced a class of analytically tractable coordinated optimization models and solved representative examples, in which a spatially complex organization of the OP map is induced by interactions between the maps. We found that these solutions near symmetry breaking threshold predict a highly ordered map layout. Here we examine the time course of the convergence towards attractor states and optima of these models. In particular, we determine the timescales on which map optimization takes place and how these timescales can be compared to those of visual cortical development and plasticity. We also assess whether our models exhibit biologically more realistic, spatially irregular solutions at a finite distance from threshold, when the spatial periodicities of the two maps are detuned and when considering more than 2 feature dimensions. We show that, although maps typically undergo substantial rearrangement, no other solutions than pinwheel crystals and stripes dominate in the emerging layouts. Pinwheel crystallization takes place on a rather short timescale and can also occur for detuned wavelengths of different maps. Our numerical results thus support the view that neither minimal energy states nor intermediate transient states of our coordinated optimization models successfully explain the architecture of the visual cortex. We discuss several alternative scenarios that may improve the agreement between model solutions and biological

  8. Extensive Admixture and Selective Pressure Across the Sahel Belt.

    PubMed

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-12-01

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection). PMID:26614524

  9. Extensive Admixture and Selective Pressure Across the Sahel Belt

    PubMed Central

    Triska, Petr; Soares, Pedro; Patin, Etienne; Fernandes, Veronica; Cerny, Viktor; Pereira, Luisa

    2015-01-01

    Genome-wide studies of African populations have the potential to reveal powerful insights into the evolution of our species, as these diverse populations have been exposed to intense selective pressures imposed by infectious diseases, diet, and environmental factors. Within Africa, the Sahel Belt extensively overlaps the geographical center of several endemic infections such as malaria, trypanosomiasis, meningitis, and hemorrhagic fevers. We screened 2.5 million single nucleotide polymorphisms in 161 individuals from 13 Sahelian populations, which together with published data cover Western, Central, and Eastern Sahel, and include both nomadic and sedentary groups. We confirmed the role of this Belt as a main corridor for human migrations across the continent. Strong admixture was observed in both Central and Eastern Sahelian populations, with North Africans and Near Eastern/Arabians, respectively, but it was inexistent in Western Sahelian populations. Genome-wide local ancestry inference in admixed Sahelian populations revealed several candidate regions that were significantly enriched for non-autochthonous haplotypes, and many showed to be under positive selection. The DARC gene region in Arabs and Nubians was enriched for African ancestry, whereas the RAB3GAP1/LCT/MCM6 region in Oromo, the TAS2R gene family in Fulani, and the ALMS1/NAT8 in Turkana and Samburu were enriched for non-African ancestry. Signals of positive selection varied in terms of geographic amplitude. Some genomic regions were selected across the Belt, the most striking example being the malaria-related DARC gene. Others were Western-specific (oxytocin, calcium, and heart pathways), Eastern-specific (lipid pathways), or even population-restricted (TAS2R genes in Fulani, which may reflect sexual selection). PMID:26614524

  10. Ancestry inference in complex admixtures via variable-length Markov chain linkage models.

    PubMed

    Rodriguez, Jesse M; Bercovici, Sivan; Elmore, Megan; Batzoglou, Serafim

    2013-03-01

    Inferring the ancestral origin of chromosomal segments in admixed individuals is key for genetic applications, ranging from analyzing population demographics and history, to mapping disease genes. Previous methods addressed ancestry inference by using either weak models of linkage disequilibrium, or large models that make explicit use of ancestral haplotypes. In this paper we introduce ALLOY, an efficient method that incorporates generalized, but highly expressive, linkage disequilibrium models. ALLOY applies a factorial hidden Markov model to capture the parallel process producing the maternal and paternal admixed haplotypes, and models the background linkage disequilibrium in the ancestral populations via an inhomogeneous variable-length Markov chain. We test ALLOY in a broad range of scenarios ranging from recent to ancient admixtures with up to four ancestral populations. We show that ALLOY outperforms the previous state of the art, and is robust to uncertainties in model parameters. PMID:23421795

  11. Ancestry Inference in Complex Admixtures via Variable-length Markov Chain Linkage Models

    PubMed Central

    Bercovici, Sivan; Elmore, Megan; Batzoglou, Serafim

    2013-01-01

    Abstract Inferring the ancestral origin of chromosomal segments in admixed individuals is key for genetic applications, ranging from analyzing population demographics and history, to mapping disease genes. Previous methods addressed ancestry inference by using either weak models of linkage disequilibrium, or large models that make explicit use of ancestral haplotypes. In this paper we introduce ALLOY, an efficient method that incorporates generalized, but highly expressive, linkage disequilibrium models. ALLOY applies a factorial hidden Markov model to capture the parallel process producing the maternal and paternal admixed haplotypes, and models the background linkage disequilibrium in the ancestral populations via an inhomogeneous variable-length Markov chain. We test ALLOY in a broad range of scenarios ranging from recent to ancient admixtures with up to four ancestral populations. We show that ALLOY outperforms the previous state of the art, and is robust to uncertainties in model parameters. PMID:23421795

  12. A study of mapping exogenous knowledge representations into CONFIG

    NASA Technical Reports Server (NTRS)

    Mayfield, Blayne E.

    1992-01-01

    Qualitative reasoning is reasoning with a small set of qualitative values that is an abstraction of a larger and perhaps infinite set of quantitative values. The use of qualitative and quantitative reasoning together holds great promise for performance improvement in applications that suffer from large and/or imprecise knowledge domains. Included among these applications are the modeling, simulation, analysis, and fault diagnosis of physical systems. Several research groups continue to discover and experiment with new qualitative representations and reasoning techniques. However, due to the diversity of these techniques, it is difficult for the programs produced to exchange system models easily. The availability of mappings to transform knowledge from the form used by one of these programs to that used by another would open the doors for comparative analysis of these programs in areas such as completeness, correctness, and performance. A group at the Johnson Space Center (JSC) is working to develop CONFIG, a prototype qualitative modeling, simulation, and analysis tool for fault diagnosis applications in the U.S. space program. The availability of knowledge mappings from the programs produced by other research groups to CONFIG may provide savings in CONFIG's development costs and time, and may improve CONFIG's performance. The study of such mappings is the purpose of the research described in this paper. Two other research groups that have worked with the JSC group in the past are the Northwest University Group and the University of Texas at Austin Group. The former has produced a qualitative reasoning tool named SIMGEN, and the latter has produced one named QSIM. Another program produced by the Austin group is CC, a preprocessor that permits users to develop input for eventual use by QSIM, but in a more natural format. CONFIG and CC are both based on a component-connection ontology, so a mapping from CC's knowledge representation to CONFIG's knowledge

  13. Performance Engineering/Organization Mapping: A Case Study.

    ERIC Educational Resources Information Center

    James, Randolph I.

    1987-01-01

    Describes how two methodologies for analyzing and improving performance--performance engineering and organization mapping--were used in a case study involving the purchasing department of an electric utility. Highlights include the establishment of a model of the desired results, measuring existing performance, and the designing of an improvement…

  14. Use of Technology-Assisted Techniques of Mind Mapping and Concept Mapping in Science Education: A Constructivist Study

    ERIC Educational Resources Information Center

    Balim, Ali Günay

    2013-01-01

    The study aims to investigate the effects of using mind maps and concept maps on students' learning of concepts in science courses. A total of 51 students participated in this study which used a quasi-experimental research design with pre-test/post-test control groups. The constructivist-inspired study was carried out in the sixth-grade…

  15. Compatibility of repair mortar with migrating corrosion inhibiting admixtures

    SciTech Connect

    Bjegovic, D.; Ukrainczyk, V.; Ukrainczyk, B.; Miksic, B.

    1997-08-01

    One of the methods for corrosion protection of reinforced concrete is the use of migrating corrosion inhibitor as an admixture in repair mortars. The admixture must be effective for corrosion protection and compatible with polymers added to repair mortar to improve properties of fresh and hardened mortar. This paper presents experimental results on compatibility of a migrating corrosion inhibitor added to two repair mortars based on an inorganic binder modified with polymers. The influence of a migrating inhibitor on the properties of fresh and hardened mortars was tested. The effectiveness on reinforcement corrosion protection has been tested according to ASTM G 109. Test results prove that the investigated migrating inhibitor is compatible with repair mortars and that it delays corrosion of the reinforcement.

  16. The phenotypic legacy of admixture between modern humans and Neandertals.

    PubMed

    Simonti, Corinne N; Vernot, Benjamin; Bastarache, Lisa; Bottinger, Erwin; Carrell, David S; Chisholm, Rex L; Crosslin, David R; Hebbring, Scott J; Jarvik, Gail P; Kullo, Iftikhar J; Li, Rongling; Pathak, Jyotishman; Ritchie, Marylyn D; Roden, Dan M; Verma, Shefali S; Tromp, Gerard; Prato, Jeffrey D; Bush, William S; Akey, Joshua M; Denny, Joshua C; Capra, John A

    2016-02-12

    Many modern human genomes retain DNA inherited from interbreeding with archaic hominins, such as Neandertals, yet the influence of this admixture on human traits is largely unknown. We analyzed the contribution of common Neandertal variants to over 1000 electronic health record (EHR)-derived phenotypes in ~28,000 adults of European ancestry. We discovered and replicated associations of Neandertal alleles with neurological, psychiatric, immunological, and dermatological phenotypes. Neandertal alleles together explained a significant fraction of the variation in risk for depression and skin lesions resulting from sun exposure (actinic keratosis), and individual Neandertal alleles were significantly associated with specific human phenotypes, including hypercoagulation and tobacco use. Our results establish that archaic admixture influences disease risk in modern humans, provide hypotheses about the effects of hundreds of Neandertal haplotypes, and demonstrate the utility of EHR data in evolutionary analyses. PMID:26912863

  17. The phenotypic legacy of admixture between modern humans and Neanderthals

    PubMed Central

    Simonti, Corinne N.; Vernot, Benjamin; Bastarache, Lisa; Bottinger, Erwin; Carrell, David S.; Chisholm, Rex L.; Crosslin, David R.; Hebbring, Scott J.; Jarvik, Gail P.; Kullo, Iftikhar J.; Li, Rongling; Pathak, Jyotishman; Ritchie, Marylyn D.; Roden, Dan M.; Verma, Shefali S.; Tromp, Gerard; Prato, Jeffrey D.; Bush, William S.; Akey, Joshua M.; Denny, Joshua C.; Capra, John A.

    2016-01-01

    Many modern human genomes retain DNA inherited from interbreeding with archaic hominins, such as Neanderthals, yet the influence of this admixture on human traits is largely unknown. We analyzed the contribution of common Neanderthal variants to over 1,000 electronic health record (EHR)-derived phenotypes in ~28,000 adults of European ancestry. We discovered and replicated associations of Neanderthal alleles with neurological, psychiatric, immunological, and dermatological phenotypes. Neanderthal alleles together explain a significant fraction of the variation in risk for depression and skin lesions resulting from sun exposure (actinic keratosis), and individual Neanderthal alleles are significantly associated with specific human phenotypes, including hypercoagulation and tobacco use. Our results establish that archaic admixture influences disease risk in modern humans, provide hypotheses about the effects of hundreds of Neanderthal haplotypes and demonstrate the utility of EHR data in evolutionary analyses. PMID:26912863

  18. Genetic admixture and obesity: recent perspectives and future applications

    PubMed Central

    Fernández, José R.; Pearson, Keith E.; Kell, Kenneth P.; Brown, Michelle M. Bohan

    2013-01-01

    The process of the colonization of the New World that occurred centuries ago served as a natural experiment, creating unique combinations of genetic material in newly formed admixed populations. The identification and genotyping of ancestry informative markers (AIMs) have allowed for the estimation of proportions of ancestral parental populations among individuals in a sample through the genetic admixture approach. These admixture estimates have been used in different ways to understand the genetic contributions to individual variation in obesity and body composition parameters, particularly among diverse admixed groups known to differ in obesity prevalence within the United States. Although progress has been made through the use of genetic admixture approaches, future investigations are needed in order to explore the interaction of environmental factors with the degree of genetic ancestry in individuals. A challenge to confront at this time would be to further stratify and define environments in progressively more granular terms, including nutrients, muscle biology, stress responses at the cellular level, and the social and built environments. PMID:24081225

  19. GIS-study and new Geomorphologic Mapping of Phobos

    NASA Astrophysics Data System (ADS)

    Kokhanov, Alexander; Lorenz, Cyrill; Karachevtseva, Irina

    2016-04-01

    Using raw images and processed orthoimages, obtained from "Mars Express", we have created a new GIS-catalog of grooves. During analysis, new grooves, not identified in earlier mapping attempts, were detected. For craters study the previously created catalog of craters with D >200 m [1] was used. The spatial orientation of individual grooves was estimated, which allows us to group them into several sets. All grooves in the catalog were divided into three morphological types: gutters (simple line depressions), chains of contiguous funnels, chains of noncontigual funnels. Studying craters we paid attention to its inner and outer morphology. The shape of some craters is different from the isometric. Among them were identified elliptical and polygonal craters. The study of inner morphology showed, that there prevails simple bowl-shaped craters. Also we identified a small population of craters with complex internal morphology [2], which, by analogy with similar lunar craters [3], divided into flat-bottomed, with a central mound and concentric craters. Moreover, based on elevation data, obtained from global digital elevation model [4] and calculation of relative depth, craters with D >2 km by the stage of degradation were classified. Focusing on a combination of grooves and craters, we have identified 15 morphological regions. A morphological unit was defined as a region with a certain type of relief, which differs from surrounding areas by the presence, orientation and spatial relations of groove systems and large craters (over 200 m). Each region may have its own geological history and consequently, specific history of regolith exposure. Finally, two geomorphologic maps of Phobos were created. One map represents the spatial distributions of grooves including their classifications by morphological types. The identified morphological regions are shown, and relief characteristics of these regions are briefly described. Geomorphologic map of craters shows the spatial

  20. Growth and characterization of pure and semiorganic nonlinear optical Lithium Sulphate admixtured l-alanine crystal

    NASA Astrophysics Data System (ADS)

    Vela, T.; Selvarajan, P.; Freeda, T. H.; Balasubramanian, K.

    2013-04-01

    Lithium sulphate admixtured l-alanine (LSLA) salt was synthesized and the solubility of the commercially available l-alanine and the synthesized LSLA sample was determined in de-ionized water at various temperatures. In accordance with the solubility data, the saturated aqueous solutions of l-alanine and lithium admixtured l-alanine were prepared separately and the single crystals of the samples were grown by the solution method with a slow evaporation technique. Studying single x-ray diffraction shows that pure and LSLA crystal belong to the orthorhombic system with a non-centrosymmetric space group P212121. Using the powder x-ray diffraction study, the crystallinity of the grown crystals is confirmed and the diffraction peaks are indexed. The various functional groups present in the pure and LSLA crystal are elucidated from Fourier transform infrared spectroscopy study. UV-visible transmittance is recorded to study the optical transmittance range for the grown crystals. The powder second harmonic generation test confirms the nonlinear optical property of the grown crystals. From the microhardness test, the hardness of the grown crystals is estimated. The dielectric behaviour, such as the dielectric constant and the loss of the sample, are measured as a function of temperature and frequency. The ac conductivity of the grown crystals is also studied and the activation energy is calculated.

  1. Trans-ethnic study design approaches for fine-mapping.

    PubMed

    Asimit, Jennifer L; Hatzikotoulas, Konstantinos; McCarthy, Mark; Morris, Andrew P; Zeggini, Eleftheria

    2016-08-01

    Studies that traverse ancestrally diverse populations may increase power to detect novel loci and improve fine-mapping resolution of causal variants by leveraging linkage disequilibrium differences between ethnic groups. The inclusion of African ancestry samples may yield further improvements because of low linkage disequilibrium and high genetic heterogeneity. We investigate the fine-mapping resolution of trans-ethnic fixed-effects meta-analysis for five type II diabetes loci, under various settings of ancestral composition (European, East Asian, African), allelic heterogeneity, and causal variant minor allele frequency. In particular, three settings of ancestral composition were compared: (1) single ancestry (European), (2) moderate ancestral diversity (European and East Asian), and (3) high ancestral diversity (European, East Asian, and African). Our simulations suggest that the European/Asian and European ancestry-only meta-analyses consistently attain similar fine-mapping resolution. The inclusion of African ancestry samples in the meta-analysis leads to a marked improvement in fine-mapping resolution. PMID:26839038

  2. a Study of Sasin-Animal Sky Map on Chonmunryucho

    NASA Astrophysics Data System (ADS)

    Yang, Hong-Jin; Park, Myeong-Gu

    2003-03-01

    Chon-Mun-Ryu-Cho, written (edited) by Lee Sun-Ji during the period of King Se-Jong, is a representative astronomy book of Cho-Sun (A.D. 1392 -1910) Dynasty. We find and study in the first page of the book; the description of 28 oriental constellations as a Sasin (four mythical oriental animals)-animal sky map which is not widely known yet. The map consists of four groups of constellations, each of which represents the Sasin: Chang-Ryong (dragon), Baek-Ho (tigers with Ki-Rin [Oriental giraffe]), Ju-Jak (Chinese phoenix), Hyun-Mu (a tortoise interwined with a snake). Each group (animals) spans 2˜7 of 28 oriental constellations As we know from the illustration of the Chon-Sang-Yol-Cha-Bun-Ya-Ji-Do a representative sky map of Cho-Sun Dynasty, astronomy in Cho-Sun Dynasty is closely related to that in Go-Gu-Ryer (B.C. 37 -A.D. 668) Dynasty. Since these Sasin-animals appear in most mural paintings of Go-Gu-Ryer tombs, visualization of sky with these animal constellations could have been established as early as in Go-Gu-Ryer Dynasty. We also reconstruct this ''A Sasin-animal Korean sky map'' based on the shapes of the Sasin and Ki-Rin from Go-Gu-Ryer paintings and 28 oriental constellations in Chon-Sang-Yol-Cha-Bun-Ya-Ji-Do.

  3. Isolation with differentiation followed by expansion with admixture in the tunicate Pyura chilensis

    PubMed Central

    2013-01-01

    Background Pyura chilensis, a tunicate commercially exploited as food resource in Chile, is subject to management strategies, including restocking. The goal of this study was to examine the genetic structure of P. chilensis using information from a mitochondrial gene (Cytochrome Oxidase I, COI) and a nuclear gene (Elongation 1 alpha, EF1a), to characterize the geographic distribution of genetic diversity and differentiation, and to identify the main processes that have shaped it. We analyzed 268 and 208 sequences of COI and EF1a, respectively, from samples of eight local populations covering ca. 1800 km. Results For Pyura chilensis, partial sequences of the gene COI revealed three highly supported haplogroups that diverged 260000 to 470000 years ago. Two haplogroups currently are widely distributed and sympatric, while one is dominant only in Los Molinos (LM, 39°50′S). The two widespread COI haplogroups underwent a geographic expansion during an interglacial period of the Late Pleistocene ca. 100000 years ago. The nuclear gene was less divergent and did not resolve the COI haplogroups. Bayesian clustering of the nuclear gene’s SNPs revealed that individuals from the two widespread COI haplogroups were mostly assigned to two of the three detected clusters and had a marked degree of admixture. The third cluster predominated in LM and showed low admixture. Haplotypic diversity of both genes was very high, there was no isolation by distance, and most localities were genetically undifferentiated; only LM was consistently differentiated with both genes analyzed. Conclusions Pyura chilensis has less genetic structure than expected given its life history, which could be a consequence of dispersal on ship hulls. The only differentiated local population analyzed was LM. Coincidentally, it is the one furthest away from main maritime routes along the coast of Chile. The use of mitochondrial and nuclear markers allowed detection of divergent mitochondrial haplogroups in

  4. Genetic admixture and lineage separation in a southern Andean plant.

    PubMed

    Morello, Santiago; Sede, Silvana M

    2016-01-01

    Mountain uplifts have generated new ecologic opportunities for plants, and triggered evolutionary processes, favouring an increase on the speciation rate in all continents. Moreover, mountain ranges may act as corridors or barriers for plant lineages and populations. In South America a high rate of diversification has been linked to Andean orogeny during Pliocene/Miocene. More recently, Pleistocene glacial cycles have also shaped species distribution and demography. The endemic genus Escallonia is known to have diversified in the Andes. Species with similar morphology obscure species delimitation and plants with intermediate characters occur naturally. The aim of this study is to characterize genetic variation and structure of two widespread species of Escallonia: E. alpina and E. rubra We analyzed the genetic variation of populations of the entire distribution range of the species and we also included those with intermediate morphological characters; a total of 94 accessions from 14 populations were used for the Amplified Fragment Length Polymorphism (AFLP) analysis. Plastid DNA sequences (trnS-trnG, 3'trnV-ndhC intergenic spacers and the ndhF gene) from sixteen accessions of Escallonia species were used to construct a Statistical Parsimony network. Additionally, we performed a geometric morphometrics analysis on 88 leaves from 35 individuals of the two E. alpina varieties to further study their differences. Wright's Fst and analysis of molecular variance tests performed on AFLP data showed a significant level of genetic structure at the species and population levels. Intermediate morphology populations showed a mixed genetic contribution from E. alpina var. alpina and E. rubra both in the Principal Coordinates Analysis (PCoA) and STRUCTURE. On the other hand, E. rubra and the two varieties of E. alpina are well differentiated and assigned to different genetic clusters. Moreover, the Statistical Parsimony network showed a high degree of divergence between the

  5. Genetic admixture and lineage separation in a southern Andean plant

    PubMed Central

    Morello, Santiago; Sede, Silvana M.

    2016-01-01

    Mountain uplifts have generated new ecologic opportunities for plants, and triggered evolutionary processes, favouring an increase on the speciation rate in all continents. Moreover, mountain ranges may act as corridors or barriers for plant lineages and populations. In South America a high rate of diversification has been linked to Andean orogeny during Pliocene/Miocene. More recently, Pleistocene glacial cycles have also shaped species distribution and demography. The endemic genus Escallonia is known to have diversified in the Andes. Species with similar morphology obscure species delimitation and plants with intermediate characters occur naturally. The aim of this study is to characterize genetic variation and structure of two widespread species of Escallonia: E. alpina and E. rubra. We analyzed the genetic variation of populations of the entire distribution range of the species and we also included those with intermediate morphological characters; a total of 94 accessions from 14 populations were used for the Amplified Fragment Length Polymorphism (AFLP) analysis. Plastid DNA sequences (trnS-trnG, 3′trnV-ndhC intergenic spacers and the ndhF gene) from sixteen accessions of Escallonia species were used to construct a Statistical Parsimony network. Additionally, we performed a geometric morphometrics analysis on 88 leaves from 35 individuals of the two E. alpina varieties to further study their differences. Wright’s Fst and analysis of molecular variance tests performed on AFLP data showed a significant level of genetic structure at the species and population levels. Intermediate morphology populations showed a mixed genetic contribution from E. alpina var. alpina and E. rubra both in the Principal Coordinates Analysis (PCoA) and STRUCTURE. On the other hand, E. rubra and the two varieties of E. alpina are well differentiated and assigned to different genetic clusters. Moreover, the Statistical Parsimony network showed a high degree of divergence between the

  6. Characterizing human retinotopic mapping with conformal geometry: a preliminary study

    NASA Astrophysics Data System (ADS)

    Ta, Duyan; Shi, Jie; Barton, Brian; Brewer, Alyssa; Lu, Zhong-Lin; Wang, Yalin

    2014-03-01

    Functional magnetic resonance imaging (fMRI) has been widely used to measure the retinotopic organization of early visual cortex in the human brain. Previous studies have identified multiple visual field maps (VFMs) based on statistical analysis of fMRI signals, but the resulting geometry has not been fully characterized with mathematical models. Here we test whether VFMs V1 and V2 obey the least restrictive of all geometric mappings; that is, whether they are anglepreserving and therefore maintain conformal mapping. We measured retinotopic organization in individual subjects using standard traveling-wave fMRI methods. Visual stimuli consisted of black and white, drifting checkerboards comprising rotating wedges and expanding rings to measure the cortical representations of polar angle and eccentricity, respectively. These representations were then projected onto a 3D cortical mesh of each hemisphere. By generating a mapped unit disk that is conformal of the VFMs using spherical stereographic projection and computing the parameterized coordinates of the eccentricity and polar angle gradients, we computed Beltrami coefficients to check whether the mapping from the visual field to the V1 and V2 cortical representations is conformal. We find that V1 and V2 exhibit local conformality. Our analysis of the Beltrami coefficient shows that selected regions of V1 and V2 that contain reasonably smooth eccentricity and polar angle gradients do show significant local conformality, warranting further investigation of this approach for analysis of early and higher visual cortex. These results suggest that such a mathematical model can be used to characterize the early VFMs in human visual cortex.

  7. Chemical and structural properties of Jordanian zeolitic tuffs and their admixtures with urea and thiourea: Potential scavengers for phenolics in aqueous medium

    SciTech Connect

    Yousef, R.I.; Tutunji, M.F.; Derwish, G.A.W.; Musleh, S.M.

    1999-08-15

    Native Jordanian zeolitic tuffs, rich in phillipsite, were treated with urea and thiourea. The chemical and structural properties of the tuffs and their urea and thiourea admixtures were studied using SEM, XRF, XRD, and FTIR techniques, and their adsorption capacities were estimated by the methylene blue method. The urea and thiourea treatment has not affected the mineral constitution of the tuffs. The results revealed that urea and thiourea were linked by hydrogen bonding through the NH{sub 2} moiety to the zeolite substrate, with urea showing the strongest effect. Experiments were carried out to investigate the possible use of the prepared materials for the removal of phenol and chlorinated phenols from aqueous solutions. Although thiourea caused a reduction in the relative surface area, both urea and thiourea admixtures were more effective than the free zeolitic tuff in the removal of phenol and chlorinated phenols from water, with urea admixture displaying the largest removal capacity.

  8. Properties of high-performance concrete containing shrinkage-reducing admixture

    SciTech Connect

    Folliard, K.J.; Berke, N.S.

    1997-09-01

    The effects of a recently developed shrinkage-reducing admixture on high-performance concrete properties are described. High-performance concrete mixtures containing silica fume were cast with and without shrinkage-reducing admixture. The mechanical properties, drying shrinkage, and resistance to restrained shrinkage cracking were investigated. The results show that the shrinkage-reducing admixture effectively reduced the shrinkage of high-performance concrete, and resulted in a significant decrease in restrained shrinkage cracking.

  9. Dating the age of admixture via wavelet transform analysis of genome-wide data.

    PubMed

    Pugach, Irina; Matveyev, Rostislav; Wollstein, Andreas; Kayser, Manfred; Stoneking, Mark

    2011-01-01

    We describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixed human populations. The wavelet transform method offers better resolution than existing methods for dating admixture, and can be applied to either SNP or sequence data from humans or other species. PMID:21352535

  10. Dating the age of admixture via wavelet transform analysis of genome-wide data

    PubMed Central

    2011-01-01

    We describe a PCA-based genome scan approach to analyze genome-wide admixture structure, and introduce wavelet transform analysis as a method for estimating the time of admixture. We test the wavelet transform method with simulations and apply it to genome-wide SNP data from eight admixed human populations. The wavelet transform method offers better resolution than existing methods for dating admixture, and can be applied to either SNP or sequence data from humans or other species. PMID:21352535

  11. Differential Evolution approach to detect recent admixture

    PubMed Central

    2015-01-01

    The genetic structure of human populations is extraordinarily complex and of fundamental importance to studies of anthropology, evolution, and medicine. As increasingly many individuals are of mixed origin, there is an unmet need for tools that can infer multiple origins. Misclassification of such individuals can lead to incorrect and costly misinterpretations of genomic data, primarily in disease studies and drug trials. We present an advanced tool to infer ancestry that can identify the biogeographic origins of highly mixed individuals. reAdmix can incorporate individual's knowledge of ancestors (e.g. having some ancestors from Turkey or a Scottish grandmother). reAdmix is an online tool available at http://chcb.saban-chla.usc.edu/reAdmix/. PMID:26111206

  12. In vivo efficacy and toxicity evaluation of polycaprolactone nanoparticles and aluminum based admixture formulation as vaccine delivery system.

    PubMed

    Bansal, Vivek; Kumar, Manoj; Bhardwaj, Arun; Brahmne, H G; Singh, Harpal

    2015-10-13

    Delivery of antigen through admixture formulation containing poly caprolactone (PCL) and aluminum phosphate was studied as a promising strategy to generate antigen specific immune response. The present study demonstrates the synergistic effect of admixture formulation of PCL with reduced aluminum (PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT) as a potential adjuvant system using tetanus toxoid (TT) as a model antigen. On evaluation of the magnitude of efficacy for the proposed formulation by ELISA as well as challenge method, persistent and strong antibody response was obtained throughout the 180 day study period on storage at 5 ± 3 °C. In comparison to the aluminum phosphate based conventional tetanus vaccine, higher levels of IFN-γ and IL-4 were obtained with PCL-Al 0.2 mg-TT and PCL-PEG-Al 0.2 mg-TT, indicating the presence of cell mediated as well as humoral immune responses. Histopathology and serum biochemistry profile in mice further indicated the suitability of the proposed formulation. Percent adsorption/encapsulation of the antigen also increased to nearly 95% in the admixture formulation compared to 55% adsorption in the conventional tetanus vaccine. The present study established a useful baseline for designing biocompatible and effective delivery system for toxoid vaccines through judicious use of PCL based biodegradable nanoparticles in combination with aluminum phosphate. PMID:26343498

  13. Mapping the informal science education landscape: An exploratory study.

    PubMed

    Falk, John H; Randol, Scott; Dierking, Lynn D

    2012-10-01

    This study investigated the informal science education (ISE) field to determine whether it currently functions as an effective community of practice. Research questions included: How do professionals describe and self-identify their practice, including what missions, goals and motivating factors influence their professional work? What challenges do they face and how are these resolved? Is participation in ISE activities perceived as core or peripheral to their work? Open-ended interviews were conducted with high-level representatives of 17 different ISE sub-communities; results were analyzed qualitatively. Findings showed this broad assortment of ISE sub-communities as not currently functioning as a cohesive community of practice. Although examples of shared practice and ways of talking were found, evidence of widespread, active relationship-building over time and coalescence around issues of common concern were absent. A current "map" of the ISE community is proposed and thoughts about how this map could alter in the future are suggested. PMID:23832563

  14. Study of smartphone suitability for mapping of skin chromophores.

    PubMed

    Kuzmina, Ilona; Lacis, Matiss; Spigulis, Janis; Berzina, Anna; Valeine, Lauma

    2015-09-01

    RGB (red-green-blue) technique for mapping skin chromophores by smartphones is proposed and studied. Three smartphones of different manufacturers were tested on skin phantoms and in vivo on benign skin lesions using a specially designed light source for illumination. Hemoglobin and melanin indices obtained by these smartphones showed differences in both tests. In vitro tests showed an increment of hemoglobin and melanin indices with the concentration of chromophores in phantoms. In vivo tests indicated higher hemoglobin index in hemangiomas than in nevi and healthy skin, and nevi showed higher melanin index compared to the healthy skin. Smartphones that allow switching off the automatic camera settings provided useful data, while those with “embedded” automatic settings appear to be useless for distant skin chromophore mapping. PMID:26405818

  15. Study of smartphone suitability for mapping of skin chromophores

    NASA Astrophysics Data System (ADS)

    Kuzmina, Ilona; Lacis, Matiss; Spigulis, Janis; Berzina, Anna; Valeine, Lauma

    2015-09-01

    RGB (red-green-blue) technique for mapping skin chromophores by smartphones is proposed and studied. Three smartphones of different manufacturers were tested on skin phantoms and in vivo on benign skin lesions using a specially designed light source for illumination. Hemoglobin and melanin indices obtained by these smartphones showed differences in both tests. In vitro tests showed an increment of hemoglobin and melanin indices with the concentration of chromophores in phantoms. In vivo tests indicated higher hemoglobin index in hemangiomas than in nevi and healthy skin, and nevi showed higher melanin index compared to the healthy skin. Smartphones that allow switching off the automatic camera settings provided useful data, while those with "embedded" automatic settings appear to be useless for distant skin chromophore mapping.

  16. The radiation stability of ground granulated blast furnace slag/ordinary Portland cement grouts containing organic admixtures

    SciTech Connect

    Palmer, J.D.; Fairhall, G.A.

    1993-12-31

    At the British Nuclear Fuels (BNFL) Sellafield reprocessing plant in the United Kingdom, cement grouts based on ground granulated blast-furnace slag (BFS) and ordinary Portland cement (OPC) are used extensively for immobilizing radioactive wastes. These grouts have excluded organic admixtures in order to reduce process complexity and uncertainties, regarding the performance of organic admixtures with BFS/OPC grouts, particularly under irradiation. This study has investigated the effects of sulfonated melamine formaldehyde and naphthalene condensates on grout properties. The results show grout settlement and strengths increase on addition of additives, with the additives remaining largely in the pore solution. Under irradiation the additives breakdown liberating hydrogen and carbon dioxide. Strength and product dimensions are unaffected by irradiation.

  17. Complex Patterns of Genomic Admixture within Southern Africa

    PubMed Central

    Petersen, Desiree C.; Libiger, Ondrej; Tindall, Elizabeth A.; Hardie, Rae-Anne; Hannick, Linda I.; Glashoff, Richard H.; Mukerji, Mitali; Fernandez, Pedro; Haacke, Wilfrid; Schork, Nicholas J.; Hayes, Vanessa M.

    2013-01-01

    Within-population genetic diversity is greatest within Africa, while between-population genetic diversity is directly proportional to geographic distance. The most divergent contemporary human populations include the click-speaking forager peoples of southern Africa, broadly defined as Khoesan. Both intra- (Bantu expansion) and inter-continental migration (European-driven colonization) have resulted in complex patterns of admixture between ancient geographically isolated Khoesan and more recently diverged populations. Using gender-specific analysis and almost 1 million autosomal markers, we determine the significance of estimated ancestral contributions that have shaped five contemporary southern African populations in a cohort of 103 individuals. Limited by lack of available data for homogenous Khoesan representation, we identify the Ju/'hoan (n = 19) as a distinct early diverging human lineage with little to no significant non-Khoesan contribution. In contrast to the Ju/'hoan, we identify ancient signatures of Khoesan and Bantu unions resulting in significant Khoesan- and Bantu-derived contributions to the Southern Bantu amaXhosa (n = 15) and Khoesan !Xun (n = 14), respectively. Our data further suggests that contemporary !Xun represent distinct Khoesan prehistories. Khoesan assimilation with European settlement at the most southern tip of Africa resulted in significant ancestral Khoesan contributions to the Coloured (n = 25) and Baster (n = 30) populations. The latter populations were further impacted by 170 years of East Indian slave trade and intra-continental migrations resulting in a complex pattern of genetic variation (admixture). The populations of southern Africa provide a unique opportunity to investigate the genomic variability from some of the oldest human lineages to the implications of complex admixture patterns including ancient and recently diverged human lineages. PMID:23516368

  18. Open source projects in software engineering education: a mapping study

    NASA Astrophysics Data System (ADS)

    Nascimento, Debora M. C.; Almeida Bittencourt, Roberto; Chavez, Christina

    2015-01-01

    Context: It is common practice in academia to have students work with "toy" projects in software engineering (SE) courses. One way to make such courses more realistic and reduce the gap between academic courses and industry needs is getting students involved in open source projects (OSP) with faculty supervision. Objective: This study aims to summarize the literature on how OSP have been used to facilitate students' learning of SE. Method: A systematic mapping study was undertaken by identifying, filtering and classifying primary studies using a predefined strategy. Results: 72 papers were selected and classified. The main results were: (a) most studies focused on comprehensive SE courses, although some dealt with specific areas; (b) the most prevalent approach was the traditional project method; (c) studies' general goals were: learning SE concepts and principles by using OSP, learning open source software or both; (d) most studies tried out ideas in regular courses within the curriculum; (e) in general, students had to work with predefined projects; (f) there was a balance between approaches where instructors had either inside control or no control on the activities performed by students; (g) when learning was assessed, software artefacts, reports and presentations were the main instruments used by teachers, while surveys were widely used for students' self-assessment; (h) most studies were published in the last seven years. Conclusions: The resulting map gives an overview of the existing initiatives in this context and shows gaps where further research can be pursued.

  19. Whistler Solitons in Plasma with Anisotropic Hot Electron Admixture

    NASA Technical Reports Server (NTRS)

    Khazanov, G. V.; Krivorutsky, E. N.; Gallagher, D. L.

    1999-01-01

    The longitudinal and transverse modulation instability of whistler waves in plasma, with a small admixture of hot anisotropic electrons, is discussed. If the hot particles temperature anisotropy is positive, it is found that, in such plasma, longitudinal perturbations can lead to soliton formation for frequencies forbidden in cold plasma. The soliton is enriched by hot particles. The frequency region unstable to transverse modulation in cold plasma in the presence of hot electrons is divided by stable domains. For both cases the role of hot electrons is more significant for whistlers with smaller frequencies.

  20. Activation analysis of admixtures in certain semiconductive materials

    NASA Technical Reports Server (NTRS)

    Artyukhin, P. I.; Gilbert, E. P.; Pronin, V. A.

    1978-01-01

    The use of extractions and chromatographic operations to separate macrobases, and to divide elements into groups convenient for gamma-spectrometric analysis is discussed. Methods are described for the activation detection of some impurities in silicon, arsenic, thallium, and trichloromethylsilane, on the basis of the extraction properties of bis(2-chlorethyl ether) and dimethylbenzylalkylammonium chloride. A schematic diagram of the extraction separation of elements-admixture is presented showing the aqueous and organic phases. The content percentage of the various elements are given in tables.

  1. A minimum set of ancestry informative markers for determining admixture proportions in a mixed American population: the Brazilian set.

    PubMed

    Santos, Hadassa C; Horimoto, Andréa V R; Tarazona-Santos, Eduardo; Rodrigues-Soares, Fernanda; Barreto, Mauricio L; Horta, Bernardo L; Lima-Costa, Maria F; Gouveia, Mateus H; Machado, Moara; Silva, Thiago M; Sanches, José M; Esteban, Nubia; Magalhaes, Wagner C S; Rodrigues, Maíra R; Kehdy, Fernanda S G; Pereira, Alexandre C

    2016-05-01

    The Brazilian population is considered to be highly admixed. The main contributing ancestral populations were European and African, with Amerindians contributing to a lesser extent. The aims of this study were to provide a resource for determining and quantifying individual continental ancestry using the smallest number of SNPs possible, thus allowing for a cost- and time-efficient strategy for genomic ancestry determination. We identified and validated a minimum set of 192 ancestry informative markers (AIMs) for the genetic ancestry determination of Brazilian populations. These markers were selected on the basis of their distribution throughout the human genome, and their capacity of being genotyped on widely available commercial platforms. We analyzed genotyping data from 6487 individuals belonging to three Brazilian cohorts. Estimates of individual admixture using this 192 AIM panels were highly correlated with estimates using ~370 000 genome-wide SNPs: 91%, 92%, and 74% of, respectively, African, European, and Native American ancestry components. Besides that, 192 AIMs are well distributed among populations from these ancestral continents, allowing greater freedom in future studies with this panel regarding the choice of reference populations. We also observed that genetic ancestry inferred by AIMs provides similar association results to the one obtained using ancestry inferred by genomic data (370 K SNPs) in a simple regression model with rs1426654, related to skin pigmentation, genotypes as dependent variable. In conclusion, these markers can be used to identify and accurately quantify ancestry of Latin Americans or US Hispanics/Latino individuals, in particular in the context of fine-mapping strategies that require the quantification of continental ancestry in thousands of individuals. PMID:26395555

  2. Mapping studies of Hirschsprung disease on chromosome 13q22

    SciTech Connect

    Puffenberger, E.G.; Washington, S.S.; Cass, D.

    1994-09-01

    We have identified a large, inbred, Mennonite kindred segregating HSCR. An association mapping study was initiated to identify the gene(s) involved in the development of HSCR. Presuming segregation of a recessive locus, we searched the genome at low resolution with three multi-case families for chromosomal regions demonstrating identity-by-descent (IBD). Regions demonstrating IBD in all three mapping panel families were analyzed at high resolution using 31 additional nuclear families. This method identified a major susceptibility locus on chromosome 13q22. Four microsatellite markers, viz. D13S162, D13S160, AFM240zg9, and D13S170, showed significant results (p<0.001) when the frequency of alleles at each locus was compared between transmitted (T) and untransmitted (U) parental alleles. An additional marker, D13S317, has since been genotyped and found to demonstrate significant linkage disequilibrium as well. At locus D13S160, the 235 bp allele shows the strongest association. To estimate the penetrance of the mutant gene on 13q22, we genotyped all 58 offspring in 14 segregating (for D13S160) nuclear families. This analysis demonstrated that 36% (8/22) of 235 bp homozygotes and 27% (7/26) of 235 bp heterozygotes we affected. Overall, the calculated penetrance is 31% which accords well with the 33% value estimated by Badner et al. (1990) for colonic HSCR. In addition, two patients with HSCR and interstitial deletions of chromosome 13 have been analyzed with microsatellite markers. The common overlap region includes l3q22 and is bounded distally by D13S160. This region is thought to be syntenic with mouse chromosome 14 where the piebald locus maps. While the piebald locus is recessive and the 13q22 deletion patients argue for dominant inheritance, the mapping data from the Mennonite kindred favors an intermediate model where homozygotes are at greatest risk, but heterozygotes have a measurable risk for HSCR development.

  3. 3D Regression Heat Map Analysis of Population Study Data.

    PubMed

    Klemm, Paul; Lawonn, Kai; Glaßer, Sylvia; Niemann, Uli; Hegenscheid, Katrin; Völzke, Henry; Preim, Bernhard

    2016-01-01

    Epidemiological studies comprise heterogeneous data about a subject group to define disease-specific risk factors. These data contain information (features) about a subject's lifestyle, medical status as well as medical image data. Statistical regression analysis is used to evaluate these features and to identify feature combinations indicating a disease (the target feature). We propose an analysis approach of epidemiological data sets by incorporating all features in an exhaustive regression-based analysis. This approach combines all independent features w.r.t. a target feature. It provides a visualization that reveals insights into the data by highlighting relationships. The 3D Regression Heat Map, a novel 3D visual encoding, acts as an overview of the whole data set. It shows all combinations of two to three independent features with a specific target disease. Slicing through the 3D Regression Heat Map allows for the detailed analysis of the underlying relationships. Expert knowledge about disease-specific hypotheses can be included into the analysis by adjusting the regression model formulas. Furthermore, the influences of features can be assessed using a difference view comparing different calculation results. We applied our 3D Regression Heat Map method to a hepatic steatosis data set to reproduce results from a data mining-driven analysis. A qualitative analysis was conducted on a breast density data set. We were able to derive new hypotheses about relations between breast density and breast lesions with breast cancer. With the 3D Regression Heat Map, we present a visual overview of epidemiological data that allows for the first time an interactive regression-based analysis of large feature sets with respect to a disease. PMID:26529689

  4. Nuclear species-diagnostic SNP markers mined from 454 amplicon sequencing reveal admixture genomic structure of modern citrus varieties.

    PubMed

    Curk, Franck; Ancillo, Gema; Ollitrault, Frédérique; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Garcia-Lor, Andres; Navarro, Luis; Ollitrault, Patrick

    2015-01-01

    Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

  5. Nuclear Species-Diagnostic SNP Markers Mined from 454 Amplicon Sequencing Reveal Admixture Genomic Structure of Modern Citrus Varieties

    PubMed Central

    Curk, Franck; Ancillo, Gema; Ollitrault, Frédérique; Perrier, Xavier; Jacquemoud-Collet, Jean-Pierre; Garcia-Lor, Andres; Navarro, Luis; Ollitrault, Patrick

    2015-01-01

    Most cultivated Citrus species originated from interspecific hybridisation between four ancestral taxa (C. reticulata, C. maxima, C. medica, and C. micrantha) with limited further interspecific recombination due to vegetative propagation. This evolution resulted in admixture genomes with frequent interspecific heterozygosity. Moreover, a major part of the phenotypic diversity of edible citrus results from the initial differentiation between these taxa. Deciphering the phylogenomic structure of citrus germplasm is therefore essential for an efficient utilization of citrus biodiversity in breeding schemes. The objective of this work was to develop a set of species-diagnostic single nucleotide polymorphism (SNP) markers for the four Citrus ancestral taxa covering the nine chromosomes, and to use these markers to infer the phylogenomic structure of secondary species and modern cultivars. Species-diagnostic SNPs were mined from 454 amplicon sequencing of 57 gene fragments from 26 genotypes of the four basic taxa. Of the 1,053 SNPs mined from 28,507 kb sequence, 273 were found to be highly diagnostic for a single basic taxon. Species-diagnostic SNP markers (105) were used to analyse the admixture structure of varieties and rootstocks. This revealed C. maxima introgressions in most of the old and in all recent selections of mandarins, and suggested that C. reticulata × C. maxima reticulation and introgression processes were important in edible mandarin domestication. The large range of phylogenomic constitutions between C. reticulata and C. maxima revealed in mandarins, tangelos, tangors, sweet oranges, sour oranges, grapefruits, and orangelos is favourable for genetic association studies based on phylogenomic structures of the germplasm. Inferred admixture structures were in agreement with previous hypotheses regarding the origin of several secondary species and also revealed the probable origin of several acid citrus varieties. The developed species-diagnostic SNP

  6. Genetic structure and admixture between Bayash Roma from northwestern Croatia and general Croatian population: evidence from Bayesian clustering analysis.

    PubMed

    Novokmet, Natalija; Galov, Ana; Marjanović, Damir; Škaro, Vedrana; Projić, Petar; Lauc, Gordan; Primorac, Dragan; Rudan, Pavao

    2015-01-01

    The European Roma represent a transnational mosaic of minority population groups with different migration histories and contrasting experiences in their interactions with majority populations across the European continent. Although historical genetic contributions of European lineages to the Roma pool were investigated before, the extent of contemporary genetic admixture between Bayash Roma and non-Romani majority population remains elusive. The aim of this study was to assess the genetic structure of the Bayash Roma population from northwestern Croatia and the general Croatian population and to investigate the extent of admixture between them. A set of genetic data from two original studies (100 Bayash Roma from northwestern Croatia and 195 individuals from the general Croatian population) was analyzed by Bayesian clustering implemented in STRUCTURE software. By re-analyzing published data we intended to focus for the first time on genetic differentiation and structure and in doing so we clearly pointed to the importance of considering social phenomena in understanding genetic structuring. Our results demonstrated that two population clusters best explain the genetic structure, which is consistent with social exclusion of Roma and the demographic history of Bayash Roma who have settled in NW Croatia only about 150 years ago and mostly applied rules of endogamy. The presence of admixture was revealed, while the percentage of non-Croatian individuals in general Croatian population was approximately twofold higher than the percentage of non-Romani individuals in Roma population corroborating the presence of ethnomimicry in Roma. PMID:26244830

  7. Human Leukocyte Antigen Profiles of Latin American Populations: Differential Admixture and Its Potential Impact on Hematopoietic Stem Cell Transplantation

    PubMed Central

    Arrieta-Bolaños, Esteban; Madrigal, J. Alejandro; Shaw, Bronwen E.

    2012-01-01

    The outcome of hematopoietic stem cell transplantation (HSCT) is shaped by both clinical and genetic factors that determine its success. Genetic factors including human leukocyte antigen (HLA) and non-HLA genetic variants are believed to influence the risk of potentially fatal complications after the transplant. Moreover, ethnicity has been proposed as a factor modifying the risk of graft-versus-host disease. The populations of Latin America are a complex array of different admixture processes with varying degrees of ancestral population proportions that came in different migration waves. This complexity makes the study of genetic risks in this region complicated unless the extent of this variation is thoroughly characterized. In this study we compared the HLA-A and HLA-B allele group profiles for 31 Latin American populations and 61 ancestral populations from Iberia, Italy, Sub-Saharan Africa, and America. Results from population genetics comparisons show a wide variation in the HLA profiles from the Latin American populations that correlate with different admixture proportions. Populations in Latin America seem to be organized in at least three groups with (1) strong Amerindian admixture, (2) strong Caucasian component, and (3) a Caucasian-African gradient. These results imply that genetic risk assessment for HSCT in Latin America has to be adapted for different population subgroups rather than as a pan-Hispanic/Latino analysis. PMID:23213535

  8. Urban Groundwater Mapping - Bucharest City Area Case Study

    NASA Astrophysics Data System (ADS)

    Gaitanaru, Dragos; Radu Gogu, Constantin; Bica, Ioan; Anghel, Leonard; Amine Boukhemacha, Mohamed; Ionita, Angela

    2013-04-01

    Urban Groundwater Mapping (UGM) is a generic term for a collection of procedures and techniques used to create targeted cartographic representation of the groundwater related aspects in urban areas. The urban environment alters the physical and chemical characteristics of the underneath aquifers. The scale of the pressure is controlled by the urban development in time and space. To have a clear image on the spatial and temporal distribution of different groundwater- urban structures interaction we need a set of thematic maps is needed. In the present study it is described the methodological approach used to obtain a reliable cartographic product for Bucharest City area. The first step in the current study was to identify the groundwater related problems and aspects (changes in the groundwater table, infiltration and seepage from and to the city sewer network, contamination spread to all three aquifers systems located in quaternary sedimentary formations, dewatering impact for large underground structures, management and political drawbacks). The second step was data collection and validation. In urban areas there is a big spectrum of data providers related to groundwater. Due to the fact that data is produced and distributed by different types of organizations (national agencies, private companies, municipal water regulator, etc) the validation and cross check process is mandatory. The data is stored and managed by a geospatial database. The design of the database follows an object-orientated paradigm and is easily extensible. The third step consists of a set of procedures based on a multi criteria assessment that creates the specific setup for the thematic maps. The assessment is based on the following criteria: (1) scale effect , (2) time , (3) vertical distribution and (4) type of the groundwater related problem. The final

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

    PubMed

    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. PMID:25194159

  10. Genomewide ancestry and divergence patterns from low-coverage sequencing data reveal a complex history of admixture in wild baboons.

    PubMed

    Wall, Jeffrey D; Schlebusch, Stephen A; Alberts, Susan C; Cox, Laura A; Snyder-Mackler, Noah; Nevonen, Kimberly A; Carbone, Lucia; Tung, Jenny

    2016-07-01

    Naturally occurring admixture has now been documented in every major primate lineage, suggesting its key role in primate evolutionary history. Active primate hybrid zones can provide valuable insight into this process. Here, we investigate the history of admixture in one of the best-studied natural primate hybrid zones, between yellow baboons (Papio cynocephalus) and anubis baboons (Papio anubis) in the Amboseli ecosystem of Kenya. We generated a new genome assembly for yellow baboon and low-coverage genomewide resequencing data from yellow baboons, anubis baboons and known hybrids (n = 44). Using a novel composite likelihood method for estimating local ancestry from low-coverage data, we found high levels of genetic diversity and genetic differentiation between the parent taxa, and excellent agreement between genome-scale ancestry estimates and a priori pedigree, life history and morphology-based estimates (r(2)  = 0.899). However, even putatively unadmixed Amboseli yellow individuals carried a substantial proportion of anubis ancestry, presumably due to historical admixture. Further, the distribution of shared vs. fixed differences between a putatively unadmixed Amboseli yellow baboon and an unadmixed anubis baboon, both sequenced at high coverage, is inconsistent with simple isolation-migration or equilibrium migration models. Our findings suggest a complex process of intermittent contact that has occurred multiple times in baboon evolutionary history, despite no obvious fitness costs to hybrids or major geographic or behavioural barriers. In combination with the extensive phenotypic data available for baboon hybrids, our results provide valuable context for understanding the history of admixture in primates, including in our own lineage. PMID:27145036

  11. Cuba: exploring the history of admixture and the genetic basis of pigmentation using autosomal and uniparental markers.

    PubMed

    Marcheco-Teruel, Beatriz; Parra, Esteban J; Fuentes-Smith, Evelyn; Salas, Antonio; Buttenschøn, Henriette N; Demontis, Ditte; Torres-Español, María; Marín-Padrón, Lilia C; Gómez-Cabezas, Enrique J; Alvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Martínez-Fuentes, Antonio; Carracedo, Angel; Børglum, Anders D; Mors, Ole

    2014-07-01

    We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs) to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs) with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40%) and Santiago de Cuba (39%), and the highest proportion of Native American ancestry in Granma (15%), Holguín (12%) and Las Tunas (12%). We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample. PMID:25058410

  12. Cuba: Exploring the History of Admixture and the Genetic Basis of Pigmentation Using Autosomal and Uniparental Markers

    PubMed Central

    Fuentes-Smith, Evelyn; Salas, Antonio; Buttenschøn, Henriette N.; Demontis, Ditte; Torres-Español, María; Marín-Padrón, Lilia C.; Gómez-Cabezas, Enrique J.; Álvarez-Iglesias, Vanesa; Mosquera-Miguel, Ana; Martínez-Fuentes, Antonio; Carracedo, Ángel; Børglum, Anders D.; Mors, Ole

    2014-01-01

    We carried out an admixture analysis of a sample comprising 1,019 individuals from all the provinces of Cuba. We used a panel of 128 autosomal Ancestry Informative Markers (AIMs) to estimate the admixture proportions. We also characterized a number of haplogroup diagnostic markers in the mtDNA and Y-chromosome in order to evaluate admixture using uniparental markers. Finally, we analyzed the association of 16 single nucleotide polymorphisms (SNPs) with quantitative estimates of skin pigmentation. In the total sample, the average European, African and Native American contributions as estimated from autosomal AIMs were 72%, 20% and 8%, respectively. The Eastern provinces of Cuba showed relatively higher African and Native American contributions than the Western provinces. In particular, the highest proportion of African ancestry was observed in the provinces of Guantánamo (40%) and Santiago de Cuba (39%), and the highest proportion of Native American ancestry in Granma (15%), Holguín (12%) and Las Tunas (12%). We found evidence of substantial population stratification in the current Cuban population, emphasizing the need to control for the effects of population stratification in association studies including individuals from Cuba. The results of the analyses of uniparental markers were concordant with those observed in the autosomes. These geographic patterns in admixture proportions are fully consistent with historical and archaeological information. Additionally, we identified a sex-biased pattern in the process of gene flow, with a substantially higher European contribution from the paternal side, and higher Native American and African contributions from the maternal side. This sex-biased contribution was particularly evident for Native American ancestry. Finally, we observed that SNPs located in the genes SLC24A5 and SLC45A2 are strongly associated with melanin levels in the sample. PMID:25058410

  13. Analyses of genetic structure of Tibeto-Burman populations reveals sex-biased admixture in southern Tibeto-Burmans.

    PubMed

    Wen, Bo; Xie, Xuanhua; Gao, Song; Li, Hui; Shi, Hong; Song, Xiufeng; Qian, Tingzhi; Xiao, Chunjie; Jin, Jianzhong; Su, Bing; Lu, Daru; Chakraborty, Ranajit; Jin, Li

    2004-05-01

    An unequal contribution of male and female lineages from parental populations to admixed ones is not uncommon in the American continents, as a consequence of directional gene flow from European men into African and Hispanic Americans in the past several centuries. However, little is known about sex-biased admixture in East Asia, where substantial migrations are recorded. Tibeto-Burman (TB) populations were historically derived from ancient tribes of northwestern China and subsequently moved to the south, where they admixed with the southern natives during the past 2600 years. They are currently extensively distributed in China and Southeast Asia. In this study, we analyze the variations of 965 Y chromosomes and 754 mtDNAs in >20 TB populations from China. By examining the haplotype group distributions of Y-chromosome and mtDNA markers and their principal components, we show that the genetic structure of the extant southern Tibeto-Burman (STB) populations were primarily formed by two parental groups: northern immigrants and native southerners. Furthermore, the admixture has a bias between male and female lineages, with a stronger influence of northern immigrants on the male lineages (approximately 62%) and with the southern natives contributing more extensively to the female lineages (approximately 56%) in the extant STBs. This is the first genetic evidence revealing sex-biased admixture in STB populations, which has genetic, historical, and anthropological implications. PMID:15042512

  14. Electricity Consumption Risk Map - The use of Urban Climate Mapping for smarter analysis: Case study for Birmingham, UK.

    NASA Astrophysics Data System (ADS)

    Antunes Azevedo, Juliana; Burghardt, René; Chapman, Lee; Katzchner, Lutz; Muller, Catherine L.

    2015-04-01

    Climate is a key driving factor in energy consumption. However, income, vegetation, building mass structure, topography also impact on the amount of energy consumption. In a changing climate, increased temperatures are likely to lead to increased electricity consumption, affecting demand, distribution and generation. Furthermore, as the world population becomes more urbanized, increasing numbers of people will need to deal with not only increased temperatures from climate change, but also from the unintentional modification of the urban climate in the form of urban heat islands. Hence, climate and climate change needs to be taken into account for future urban planning aspects to increase the climate and energy resilience of the community and decrease the future social and economic costs. Geographical Information Systems provide a means to create urban climate maps as part of the urban planning process. Geostatistical analyses linking these maps with demographic and social data, enables a geo-statistical analysis to identify linkages to high-risk groups of the community and vulnerable areas of town and cities. Presently, the climatope classification is oriented towards thermal aspects and the ventilation quality (roughness) of the urban areas but can also be adapted to take into account other structural "environmental factors". This study aims to use the climatope approach to predict areas of potential high electricity consumption in Birmingham, UK. Several datasets were used to produce an average surface temperature map, vegetation map, land use map, topography map, building height map, built-up area roughness calculations, an average air temperature map and a domestic electricity consumption map. From the correlations obtained between the layers it is possible to average the importance of each factor and create a map for domestic electricity consumption to understand the influence of environmental aspects on spatial energy consumption. Based on these results city

  15. The Highway Map as a Social Studies Resource.

    ERIC Educational Resources Information Center

    Ehemann, Jane

    1981-01-01

    Presents a sample exercise for a seventh-grade geography class using Pennsylvania highway maps. Part one is designed to provide practice in map reading skills. Part two focuses on unusual place names. (Author/SJL)

  16. How important is intraspecific genetic admixture to the success of colonising populations?

    EPA Science Inventory

    Genetic admixture of divergent lineages is increasingly suspected to play an important role in the success of colonizing populations. This has become a particularly prominent theme in the literature on biological invasions, where admixture is now commonly proposed as an important...

  17. Effects of Different Mineral Admixtures on the Properties of Fresh Concrete

    PubMed Central

    Nuruddin, Muhammad Fadhil; Shafiq, Nasir

    2014-01-01

    This paper presents a review of the properties of fresh concrete including workability, heat of hydration, setting time, bleeding, and reactivity by using mineral admixtures fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Comparison of normal and high-strength concrete in which cement has been partially supplemented by mineral admixture has been considered. It has been concluded that mineral admixtures may be categorized into two groups: chemically active mineral admixtures and microfiller mineral admixtures. Chemically active mineral admixtures decrease workability and setting time of concrete but increase the heat of hydration and reactivity. On the other hand, microfiller mineral admixtures increase workability and setting time of concrete but decrease the heat of hydration and reactivity. In general, small particle size and higher specific surface area of mineral admixture are favourable to produce highly dense and impermeable concrete; however, they cause low workability and demand more water which may be offset by adding effective superplasticizer. PMID:24701196

  18. Effects of different mineral admixtures on the properties of fresh concrete.

    PubMed

    Khan, Sadaqat Ullah; Nuruddin, Muhammad Fadhil; Ayub, Tehmina; Shafiq, Nasir

    2014-01-01

    This paper presents a review of the properties of fresh concrete including workability, heat of hydration, setting time, bleeding, and reactivity by using mineral admixtures fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA). Comparison of normal and high-strength concrete in which cement has been partially supplemented by mineral admixture has been considered. It has been concluded that mineral admixtures may be categorized into two groups: chemically active mineral admixtures and microfiller mineral admixtures. Chemically active mineral admixtures decrease workability and setting time of concrete but increase the heat of hydration and reactivity. On the other hand, microfiller mineral admixtures increase workability and setting time of concrete but decrease the heat of hydration and reactivity. In general, small particle size and higher specific surface area of mineral admixture are favourable to produce highly dense and impermeable concrete; however, they cause low workability and demand more water which may be offset by adding effective superplasticizer. PMID:24701196

  19. A Probabilistic Approach for Improved Sequence Mapping in Metatranscriptomic Studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mapping millions of short DNA sequences a reference genome is a necessary step in many experiments designed to investigate the expression of genes involved in disease resistance. This is a difficult task in which several challenges often arise resulting in a suboptimal mapping. This mapping process ...

  20. Initial results of the Global Thermospheric Mapping Study (GTMS)

    NASA Technical Reports Server (NTRS)

    Oliver, W. L.; Salah, J. E.; Musgrove, R. G.; Holt, J. M.; Wickwar, V. B.; Hernandez, G. J.; Roble, R. G.

    1986-01-01

    The Global Thermospheric Mapping Study (GTMS) is a multi-technique experimental study of the thermosphere designed to map simultaneously its spatial and temporal morphology with a thoroughness and diversity of measurement techniques heretofore unachieved. The GTMS is designed around the Incoherent Scatter Radar Chain in the western hemisphere. The European incoherent scatter radars and the worldwide communities of Fabry-Perot interferometers, meteor wind radars, partial reflection drifts radars, MST radars, and satellite probes are included to extend the spatial coverage and types of measurements available. Theoretical and modeling support in the areas of thermospheric and ionospheric structure, tides, and electric fields are included to aid in program planning and data interpretation. Solar activity was low on the three observation days (F10.7 = 97, 98, 96) and magnetic conditions were unsettled to active (A = 10, 12, 20). All six incoherent scatter radar facilities collected data. Each collected F region data day and night while Saint Santin and Millstone Hill additionally collected E region data during daylight hours. Initial results from Sondrestrom and Millstone Hill are presented. Good quality Fabry Perot data were collected at Fritz Peak and San Jose dos Campos. Weather conditions produced poor results at Arequipa and Arecibo. Initial results from Fritz Peak are presented. Mesosphere/lower-thermosphere observations were conducted under the ATMAP organization. The magnetometer chains also were operational during this campaign. Initial thermospheric general circulation model predictions were made for assumed solar-geophysical conditions, and selected results are presented.

  1. Human genetic mapping studies using single sperm typing

    SciTech Connect

    Hubert, R.S.

    1993-01-01

    Sperm typing is a powerful technique that uses the polymerase chain reaction (PCR) to analyze DNA sequences within single sperm cells in order to construct genetic maps. This methodology was used to estimate the recombination fraction between D3S2 and D3S2 which was found to be 0.28 (95% CI = 0.20-0.36). Pedigree analysis was unable to determine genetic distance between these two markers due to their low informativeness. We also showed that dinucleotide and tetranucleotide repeat polymorphisms can be analyzed in single cells without using radioactivity or denaturing gels. This provides a rich new source of DANA polymorphisms for genetic mapping by sperm typing. In addition, an approach that uses the sperm typing methodology is described that can define the physical boundaries of meiotic recombination hotspots. The hotspot at 4p16.3 near the Huntington disease gene was localized to an interval between D4S10 and D4S126. These studies demonstrated the usefulness of sperm typing as a tool for the study of human genetic.

  2. Functional mapping - how to map and study the genetic architecture of dynamic complex traits.

    PubMed

    Wu, Rongling; Lin, Min

    2006-03-01

    The development of any organism is a complex dynamic process that is controlled by a network of genes as well as by environmental factors. Traditional mapping approaches for analysing phenotypic data measured at a single time point are too simple to reveal the genetic control of developmental processes. A general statistical mapping framework, called functional mapping, has been proposed to characterize, in a single step, the quantitative trait loci (QTLs) or nucleotides (QTNs) that underlie a complex dynamic trait. Functional mapping estimates mathematical parameters that describe the developmental mechanisms of trait formation and expression for each QTL or QTN. The approach provides a useful quantitative and testable framework for assessing the interplay between gene actions or interactions and developmental changes. PMID:16485021

  3. A high density physical map of chromosome 1BL supports evolutionary studies, map-based cloning and sequencing in wheat

    PubMed Central

    2013-01-01

    Background As for other major crops, achieving a complete wheat genome sequence is essential for the application of genomics to breeding new and improved varieties. To overcome the complexities of the large, highly repetitive and hexaploid wheat genome, the International Wheat Genome Sequencing Consortium established a chromosome-based strategy that was validated by the construction of the physical map of chromosome 3B. Here, we present improved strategies for the construction of highly integrated and ordered wheat physical maps, using chromosome 1BL as a template, and illustrate their potential for evolutionary studies and map-based cloning. Results Using a combination of novel high throughput marker assays and an assembly program, we developed a high quality physical map representing 93% of wheat chromosome 1BL, anchored and ordered with 5,489 markers including 1,161 genes. Analysis of the gene space organization and evolution revealed that gene distribution and conservation along the chromosome results from the superimposition of the ancestral grass and recent wheat evolutionary patterns, leading to a peak of synteny in the central part of the chromosome arm and an increased density of non-collinear genes towards the telomere. With a density of about 11 markers per Mb, the 1BL physical map provides 916 markers, including 193 genes, for fine mapping the 40 QTLs mapped on this chromosome. Conclusions Here, we demonstrate that high marker density physical maps can be developed in complex genomes such as wheat to accelerate map-based cloning, gain new insights into genome evolution, and provide a foundation for reference sequencing. PMID:23800011

  4. Spectral information in noise-mapping: An exploratory study

    NASA Astrophysics Data System (ADS)

    Pasch, Vivian; Mosconi, Patricia; Yanitelli, Marta; Cabanellas, Susana; Vazquez, Jorge; Rall, Juan C.; Miyara, Federico

    2002-11-01

    International standards such as ISO 1996 and ISO 717 as well as noise regulations in several countries are increasingly relying on spectral information in order to assess the acoustical behavior of materials and structures and the effects of noise on people. Nevertheless, the new European Union Directive on the assessment and management of environmental noise reinforces the A-weighted equivalent level (with appropriate night and evening corrections) as the preferred indicator for noise mapping. Considering that noise maps are a powerful zoning and planning resource, the idea of reporting the mean spectrum of noise at each selected location at different times is proposed and thoroughly justified. Arguments in favor of its feasibility are given, showing that, in spite of the widespread opinion, costs and required time may be reduced considerably by the use of low-priced, new-technology auxiliary equipment. Then an exploratory study is reported, in which (a) the spectrum of traffic noise in Rosario (Argentina) is compared with the internationally standardized traffic noise spectrum, and (b) the noise spectrum at an open street is compared with the noise spectrum at a street with a U-profile owing to the same vehicles.

  5. New Faults Map Study for Central Part of Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Bin Fayez, A.

    2006-05-01

    The Institute of Astronomy and Geophysics Research at King Abdulaziz City for Science and Technology installed nine earthquake portable stations in central part of Saudi Arabia around Riyadh city to record micro- seismicty that is caused by local faults. Riyadh city and central part of Saudi Arabia are located in the Arabian Plate, which is known as a relatively stable platform. However, we have been able to determine some events that was caused by local faults. Most of these events are not felt. We are using digital recorders (RefTek 72A) for data acquisition and SAISAN software for analyses. The velocity model that I have used in this study is IASPEI model. Currently I am developing a map that shows some micro-earthquake events for that region. In addition, it includes some regional events. The objective of this study is to define the active faults in central part of Saudi Arabia.

  6. Alkali-silica reactions of mortars produced by using waste glass as fine aggregate and admixtures such as fly ash and Li2CO3.

    PubMed

    Topçu, Ilker Bekir; Boğa, Ahmet Raif; Bilir, Turhan

    2008-01-01

    Use of waste glass or glass cullet (GC) as concrete aggregate is becoming more widespread each day because of the increase in resource efficiency. Recycling of wastes is very important for sustainable development. When glass is used as aggregate in concrete or mortar, expansions and internal stresses occur due to an alkali-silica reaction (ASR). Furthermore, rapid loss in durability is generally observed due to extreme crack formation and an increase in permeability. It is necessary to use some kind of chemical or mineral admixture to reduce crack formation. In this study, mortar bars are produced by using three different colors of glass in four different quantities as fine aggregate by weight, and the effects of these glass aggregates on ASR are investigated, corresponding to ASTM C 1260. Additionally, in order to reduce the expansions of mortars, 10% and 20% fly ash (FA) as mineral admixture and 1% and 2% Li(2)CO(3) as chemical admixture are incorporated by weight in the cement and their effects on expansion are examined. It is observed that among white (WG), green (GG) and brown glass (BG) aggregates, WG aggregate causes the greatest expansion. In addition, expansion increases with an increase in amount of glass. According to the test results, it is seen that over 20% FA and 2% Li(2)CO(3) replacements are required to produce mortars which have expansion values below the 0.2% critical value when exposed to ASR. However, usages of these admixtures reduce expansions occurring because of ASR. PMID:17570652

  7. Population differentiation of zander (Sander lucioperca) across native and newly colonized ranges suggests increasing admixture in the course of an invasion

    PubMed Central

    Eschbach, Erik; Nolte, Arne W; Kohlmann, Klaus; Kersten, Petra; Kail, Jochem; Arlinghaus, Robert

    2014-01-01

    In addition to ecological factors, evolutionary processes can determine the invasion success of a species. In particular, genetic admixture has the potential to induce rapid evolutionary change, which can result from natural or human-assisted secondary contact between differentiated populations. We studied the recent range expansion of zander in Germany focusing on the interplay between invasion and genetic admixture. Historically, the rivers Elbe and Danube harboured the most north-western source populations from which a north-westward range expansion occurred. This was initiated by introducing zander outside its native range into rivers and lakes, and was fostered by migration through artificial canals and stocking from various sources. We analysed zander populations of the native and invaded ranges using nuclear and mitochondrial genetic markers. Three genetic lineages were identified, which were traced to ancestral ranges. Increased genetic diversity and admixture in the invaded region highlighted asymmetric gene flow towards this area. We suppose that the adaptive potential of the invading populations was promoted by genetic admixture, whereas competitive exclusion in the native areas provided a buffer against introgression by novel genotypes. These explanations would be in line with evidence that hybridization can drive evolutionary change under conditions when new niches can be exploited. PMID:24944569

  8. Population differentiation of zander (Sander lucioperca) across native and newly colonized ranges suggests increasing admixture in the course of an invasion.

    PubMed

    Eschbach, Erik; Nolte, Arne W; Kohlmann, Klaus; Kersten, Petra; Kail, Jochem; Arlinghaus, Robert

    2014-05-01

    In addition to ecological factors, evolutionary processes can determine the invasion success of a species. In particular, genetic admixture has the potential to induce rapid evolutionary change, which can result from natural or human-assisted secondary contact between differentiated populations. We studied the recent range expansion of zander in Germany focusing on the interplay between invasion and genetic admixture. Historically, the rivers Elbe and Danube harboured the most north-western source populations from which a north-westward range expansion occurred. This was initiated by introducing zander outside its native range into rivers and lakes, and was fostered by migration through artificial canals and stocking from various sources. We analysed zander populations of the native and invaded ranges using nuclear and mitochondrial genetic markers. Three genetic lineages were identified, which were traced to ancestral ranges. Increased genetic diversity and admixture in the invaded region highlighted asymmetric gene flow towards this area. We suppose that the adaptive potential of the invading populations was promoted by genetic admixture, whereas competitive exclusion in the native areas provided a buffer against introgression by novel genotypes. These explanations would be in line with evidence that hybridization can drive evolutionary change under conditions when new niches can be exploited. PMID:24944569

  9. Land use mapping in Erie County, Pennsylvania: A pilot study

    NASA Technical Reports Server (NTRS)

    Mcmurtry, G. J.; Petersen, G. W. (Principal Investigator); May, G. A.

    1974-01-01

    The author has identified the following significant results. A pilot study was conducted to determine the feasibility of mapping land use in the Great Lakes Basin area utilizing ERTS-1 data. Small streams were clearly defined by the presence of trees along their length in predominantly agricultural country. Field patterns were easily differentiated from forested areas; dairy and beef farms were differentiated from other farmlands, but no attempt was made to identify crops. Large railroad lines and major highway systems were identified. The city of Erie and several smaller towns were identified, as well as residential areas between these towns, and docks along the shoreline in Erie. Marshes, forests, and beaches within Presque Isle State Park were correctly identified, using the DCLUS program. Bay water was differentiated from lake water, with a small amount of misclassification.

  10. Doppler ultrasound study and venous mapping in chronic venous insufficiency.

    PubMed

    García Carriazo, M; Gómez de las Heras, C; Mármol Vázquez, P; Ramos Solís, M F

    2016-01-01

    Chronic venous insufficiency of the lower limbs is very prevalent. In recent decades, Doppler ultrasound has become the method of choice to study this condition, and it is considered essential when surgery is indicated. This article aims to establish a method for the examination, including venous mapping and preoperative marking. To this end, we review the venous anatomy of the lower limbs and the pathophysiology of chronic venous insufficiency and explain the basic hemodynamic concepts and the terminology required to elaborate a radiological report that will enable appropriate treatment planning and communication with other specialists. We briefly explain the CHIVA (the acronym for the French term "cure conservatrice et hémodynamique de l'insuffisance veineuse en ambulatoire"=conservative hemodynamic treatment for chronic venous insufficiency) strategy, a minimally invasive surgical strategy that aims to restore correct venous hemodynamics without resecting the saphenous vein. PMID:26655801

  11. Velocity Map Imaging Studies of Non-Conventional Methanethiol Photochemistry

    NASA Astrophysics Data System (ADS)

    Toulson, Benjamin W.; Alaniz, Jonathan; Murray, Craig

    2014-06-01

    Velocity map imaging (VMI) in combination with state-selective resonance enhanced multiphoton ionization (REMPI) has been used to study the photodissociation dynamics of methanethiol following excitation to the first and second singlet electronically excited states. Formation of sulfur atoms, in both the singlet and triplet manifolds, is observed and can be attributed to primary dissociation of the parent molecule. We will report the nascent photofragment velocity distributions, and hence the internal energy of the methane co-fragment. Sulfur atom quantum yields are benchmarked against a known standard to evaluate the significance of this pathway. The role of non-conventional photochemical mechanisms such as roaming-mediated intersystem crossing, previously observed in methylamine photochemistry, will be discussed. James O. Thomas, Katherine E. Lower, and Craig Murray, The Journal of Physical Chemistry Letters, 2012, 3 (10), 1341-1345.

  12. Velocity-map imaging study of the photodissociation of acetaldehyde

    SciTech Connect

    Cruse, H.A.; Softley, T.P.

    2005-03-22

    Velocity-map imaging studies are reported for the photodissociation of acetaldehyde over a range of photolysis wavelengths (317.5-282.5 nm). Images are obtained for both the HCO and CH{sub 3} fragments. The mean rotational energy of both fragments increases with photodissociation energy, with a lesser degree of excitation in the CH{sub 3} fragment. The CH{sub 3} images demonstrate that the CH{sub 3} fragments are rotationally aligned with respect to the recoil direction and this is interpreted, and well modeled, on the basis of a propensity for forming CH{sub 3} fragments with M{approx}K, where M is the projection of the rotational angular momentum along the recoil direction. The origin of the CH{sub 3} rotation is conserved motion from the torsional and methyl-rocking modes of the parent molecule. Nonstatistical vibrational distributions for the CH{sub 3} fragment are obtained at higher energies.

  13. Photoinduced surface voltage mapping study for large perovskite single crystals

    NASA Astrophysics Data System (ADS)

    Liu, Xiaojing; Liu, Yucheng; Gao, Fei; Yang, Zhou; Liu, Shengzhong Frank

    2016-05-01

    Using a series of illumination sources, including white light (tungsten-halogen lamp), 445-nm, 532-nm, 635-nm, and 730-nm lasers, the surface photovoltage (SPV) images were mapped for centimeter-sized CH3NH3PbX3 (X = Cl, Br, I) perovskite single crystals using Kelvin probe force microscopy. The significant SPV signals were observed to be wavelength-dependent. We attribute the appreciable SPV to the built-in electric field in the space charge region. This study shines light into the understanding of photoinduced charge generation and separation processes at nanoscale to help advance the development of perovskite solar cells, optoelectronics, laser, photodetector, and light-emitting diode (LED).

  14. The JERS-1 Amazon Multi-Season Mapping Study (JAMMS)

    NASA Technical Reports Server (NTRS)

    Freeman, A.; Chapman, B.; Alves, M.

    1996-01-01

    Regional mapping of the Amazon basin using imaging radar is described. Two 60-day periods of radar mapping will be conducted, one in 1995, and one in 1996. One period will view the low-water season, and the other will view during the high-flood season. The main objective of the JAMMS project is to generate a regional map showing inundation throughout the Amazon Basin by comparing the two data sets.

  15. Global prostate cancer incidence and the migration, settlement, and admixture history of the Northern Europeans

    PubMed Central

    Gunderson, Kristin; Wang, Christopher Y.; Wang, Ruoxiang

    2012-01-01

    The most salient feature of prostate cancer is its striking ethnic disparity. High incidences of the disease are documented in two ethnic groups: descendents of the Northern Europeans and African Americans. Other groups, including native Africans, are much less susceptible to the disease. Given that many risk factors may contribute to carcinogenesis, an etiological cause for the ethnic disparity remains to be defined. By analyzing the global prostate cancer incidence data, we found that distribution of prostate cancer incidence coincides with the migration and settlement history of Northern Europeans. The incidences in other ethnic groups correlate to the settlement history and extent of admixture of the Europeans. This study suggests that prostate cancer has been spread by the transmission of a genetic susceptibility that resides in the Northern European genome. PMID:21167803

  16. Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations

    PubMed Central

    Kehdy, Fernanda S. G.; Gouveia, Mateus H.; Machado, Moara; Magalhães, Wagner C. S.; Horimoto, Andrea R.; Horta, Bernardo L.; Moreira, Rennan G.; Leal, Thiago P.; Scliar, Marilia O.; Soares-Souza, Giordano B.; Rodrigues-Soares, Fernanda; Araújo, Gilderlanio S.; Zamudio, Roxana; Sant Anna, Hanaisa P.; Santos, Hadassa C.; Duarte, Nubia E.; Fiaccone, Rosemeire L.; Figueiredo, Camila A.; Silva, Thiago M.; Costa, Gustavo N. O.; Beleza, Sandra; Berg, Douglas E.; Cabrera, Lilia; Debortoli, Guilherme; Duarte, Denise; Ghirotto, Silvia; Gilman, Robert H.; Gonçalves, Vanessa F.; Marrero, Andrea R.; Muniz, Yara C.; Weissensteiner, Hansi; Yeager, Meredith; Rodrigues, Laura C.; Barreto, Mauricio L.; Lima-Costa, M. Fernanda; Pereira, Alexandre C.; Rodrigues, Maíra R.; Tarazona-Santos, Eduardo

    2015-01-01

    While South Americans are underrepresented in human genomic diversity studies, Brazil has been a classical model for population genetics studies on admixture. We present the results of the EPIGEN Brazil Initiative, the most comprehensive up-to-date genomic analysis of any Latin-American population. A population-based genome-wide analysis of 6,487 individuals was performed in the context of worldwide genomic diversity to elucidate how ancestry, kinship, and inbreeding interact in three populations with different histories from the Northeast (African ancestry: 50%), Southeast, and South (both with European ancestry >70%) of Brazil. We showed that ancestry-positive assortative mating permeated Brazilian history. We traced European ancestry in the Southeast/South to a wider European/Middle Eastern region with respect to the Northeast, where ancestry seems restricted to Iberia. By developing an approximate Bayesian computation framework, we infer more recent European immigration to the Southeast/South than to the Northeast. Also, the observed low Native-American ancestry (6–8%) was mostly introduced in different regions of Brazil soon after the European Conquest. We broadened our understanding of the African diaspora, the major destination of which was Brazil, by revealing that Brazilians display two within-Africa ancestry components: one associated with non-Bantu/western Africans (more evident in the Northeast and African Americans) and one associated with Bantu/eastern Africans (more present in the Southeast/South). Furthermore, the whole-genome analysis of 30 individuals (42-fold deep coverage) shows that continental admixture rather than local post-Columbian history is the main and complex determinant of the individual amount of deleterious genotypes. PMID:26124090

  17. No clear effect of admixture between two European invading outbreaks of Diabrotica virgifera virgifera in natura.

    PubMed

    Bermond, Gérald; Cavigliasso, Fanny; Mallez, Sophie; Spencer, Joseph; Guillemaud, Thomas

    2014-01-01

    In this study, we challenged the hypothesis that admixture may have had a positive impact in the context of the European invasion of the western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte. This beetle was introduced in Europe from the USA several times since the 1980's. The multiple introductions of this major pest of cultivated corn led to the formation of two major outbreaks in North Western (NW) Italy and in Central and South Eastern (CSE) Europe that eventually merged into a secondary contact zone where insects from both outbreaks interbreed. We collected about 600 insects from this contact zone and genotyped them using 13 microsatellite markers. Three types of information were obtained from the collected individuals: (i) their survival under starvation; (ii) their admixed status, determined through a Bayesian method of genetic clustering and (iii) their mating probability, studied via the detection, isolation and genotyping of sperm in female spermathecae. Twenty six % and 12% of the individuals were assigned to the NW Italy or the CSE Europe parental types, respectively, and 23% and 39% to the F1 and backcross hybrid types, respectively. Globally, our results do not reveal any significant impact of the admixed status on the mating probability and on the choice of mating partners. However the admixed status had a sex- and sampling site-dependent effect on survival in adults under starvation. In addition sex had an effect on survival, with mortality hazard about 3 times larger in males than in females. The consequences of these findings for the evolution of the admixture zone of northern Italy are discussed. PMID:25170837

  18. No Clear Effect of Admixture between Two European Invading Outbreaks of Diabrotica virgifera virgifera in Natura

    PubMed Central

    Bermond, Gérald; Cavigliasso, Fanny; Mallez, Sophie; Spencer, Joseph; Guillemaud, Thomas

    2014-01-01

    In this study, we challenged the hypothesis that admixture may have had a positive impact in the context of the European invasion of the western corn rootworm (WCR), Diabrotica virgifera virgifera, LeConte. This beetle was introduced in Europe from the USA several times since the 1980’s. The multiple introductions of this major pest of cultivated corn led to the formation of two major outbreaks in North Western (NW) Italy and in Central and South Eastern (CSE) Europe that eventually merged into a secondary contact zone where insects from both outbreaks interbreed. We collected about 600 insects from this contact zone and genotyped them using 13 microsatellite markers. Three types of information were obtained from the collected individuals: (i) their survival under starvation; (ii) their admixed status, determined through a Bayesian method of genetic clustering and (iii) their mating probability, studied via the detection, isolation and genotyping of sperm in female spermathecae. Twenty six % and 12% of the individuals were assigned to the NW Italy or the CSE Europe parental types, respectively, and 23% and 39% to the F1 and backcross hybrid types, respectively. Globally, our results do not reveal any significant impact of the admixed status on the mating probability and on the choice of mating partners. However the admixed status had a sex- and sampling site-dependent effect on survival in adults under starvation. In addition sex had an effect on survival, with mortality hazard about 3 times larger in males than in females. The consequences of these findings for the evolution of the admixture zone of northern Italy are discussed. PMID:25170837

  19. Origin and dynamics of admixture in Brazilians and its effect on the pattern of deleterious mutations.

    PubMed

    Kehdy, Fernanda S G; Gouveia, Mateus H; Machado, Moara; Magalhães, Wagner C S; Horimoto, Andrea R; Horta, Bernardo L; Moreira, Rennan G; Leal, Thiago P; Scliar, Marilia O; Soares-Souza, Giordano B; Rodrigues-Soares, Fernanda; Araújo, Gilderlanio S; Zamudio, Roxana; Sant Anna, Hanaisa P; Santos, Hadassa C; Duarte, Nubia E; Fiaccone, Rosemeire L; Figueiredo, Camila A; Silva, Thiago M; Costa, Gustavo N O; Beleza, Sandra; Berg, Douglas E; Cabrera, Lilia; Debortoli, Guilherme; Duarte, Denise; Ghirotto, Silvia; Gilman, Robert H; Gonçalves, Vanessa F; Marrero, Andrea R; Muniz, Yara C; Weissensteiner, Hansi; Yeager, Meredith; Rodrigues, Laura C; Barreto, Mauricio L; Lima-Costa, M Fernanda; Pereira, Alexandre C; Rodrigues, Maíra R; Tarazona-Santos, Eduardo

    2015-07-14

    While South Americans are underrepresented in human genomic diversity studies, Brazil has been a classical model for population genetics studies on admixture. We present the results of the EPIGEN Brazil Initiative, the most comprehensive up-to-date genomic analysis of any Latin-American population. A population-based genome-wide analysis of 6,487 individuals was performed in the context of worldwide genomic diversity to elucidate how ancestry, kinship, and inbreeding interact in three populations with different histories from the Northeast (African ancestry: 50%), Southeast, and South (both with European ancestry >70%) of Brazil. We showed that ancestry-positive assortative mating permeated Brazilian history. We traced European ancestry in the Southeast/South to a wider European/Middle Eastern region with respect to the Northeast, where ancestry seems restricted to Iberia. By developing an approximate Bayesian computation framework, we infer more recent European immigration to the Southeast/South than to the Northeast. Also, the observed low Native-American ancestry (6-8%) was mostly introduced in different regions of Brazil soon after the European Conquest. We broadened our understanding of the African diaspora, the major destination of which was Brazil, by revealing that Brazilians display two within-Africa ancestry components: one associated with non-Bantu/western Africans (more evident in the Northeast and African Americans) and one associated with Bantu/eastern Africans (more present in the Southeast/South). Furthermore, the whole-genome analysis of 30 individuals (42-fold deep coverage) shows that continental admixture rather than local post-Columbian history is the main and complex determinant of the individual amount of deleterious genotypes. PMID:26124090

  20. Empowering line intensity mapping to study early galaxies

    NASA Astrophysics Data System (ADS)

    Comaschi, P.; Ferrara, A.

    2016-09-01

    Line intensity mapping is a superb tool to study the collective radiation from early galaxies. However, the method is hampered by the presence of strong foregrounds, mostly produced by low-redshift interloping lines. We present here a general method to overcome this problem which is robust against foreground residual noise and based on the cross-correlation function ψαL(r) between diffuse line emission and Lyα emitters (LAE). We compute the diffuse line (Lyα is used as an example) emission from galaxies in a (800Mpc)3 box at z = 5.7 and 6.6. We divide the box in slices and populate them with 14000(5500) LAEs at z = 5.7(6.6), considering duty cycles from 10-3 to 1. Both the LAE number density and slice volume are consistent with the expected outcome of the Subaru HSC survey. We add gaussian random noise with variance σN up to 100 times the variance of the Lyα emission, σα, to simulate residual foregrounds and compute ψαL(r). We find that the signal-to-noise of the observed ψαL(r) does not change significantly if σN ≤ 10σα and show that in these conditions the mean line intensity, ILyα, can be precisely recovered independently of the LAE duty cycle. Even if σN = 100σα, Iα can be constrained within a factor 2. The method works equally well for any other line (e.g. [CII], HeII) used for the intensity mapping experiment.

  1. The JERS Amazon Multi-Season Mapping Study (JAMMS): Observation Strategies and Data Characteristics

    NASA Technical Reports Server (NTRS)

    Chapman, B.; Freeman, A.; Siqueira, P.

    2000-01-01

    The JERS-1 Amazon Multi-season Mapping Study (JAMMS), part of the Global Rain Forest Mapping (GRFM) project led by the National Space Development Agency of Japan (NASDA), had an ambitious agenda to completely map the Amazon River floodpain (and surrounding areas) twice at high resolution.

  2. A Study of Asynchronous and Synchronous Discussion on Cognitive Maps in a Distributed Learning Environment.

    ERIC Educational Resources Information Center

    Bhattacharya, Madhumita

    This paper reports on a comparative study of the use of asynchronous (bulletin board) and synchronous (chat) discussion on three learning units based on the cognitive maps developed by the learners. Cognitive maps have been found to be an effective tool for learners for discussion in a distributed learning environment. Cognitive maps provided…

  3. Concept Mapping as a Study Strategy in Earth Science.

    ERIC Educational Resources Information Center

    Ault, Charles R., Jr.

    1985-01-01

    Concept mapping leads students away from rote learning and toward true understanding of concepts and their relationships. Several sample and student maps on earth science topics are presented and discussed. Applications for science instructors, students, researchers, and teacher educators are also considered. (DH)

  4. Cognitive Mapping Architectures and Hypermedia Disorientation: An Empirical Study.

    ERIC Educational Resources Information Center

    Beasley, Robert E.; Waugh, Michael L.

    1995-01-01

    Assesses hypermedia design issues and examines how learners access information in a hierarchically organized hypermedia environment. Evaluates three browsing methods: "hotwords" and two distinctively different cognitive mapping architectures. Results suggest that the inclusion of a properly constructed cognitive map can diminish feelings of…

  5. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    SciTech Connect

    Robert F. Rathbone; Thomas L. Robl

    2002-10-30

    The Clean Air Act Amendments of 1990 require large reductions in emissions of NO{sub x} from coal-fired electric utility boilers. This will necessitate the use of ammonia injection, such as in selective catalytic reduction (SCR), in many power plants, resulting in the deposition of ammonia on the fly ash. The presence of ammonia could create a major barrier to fly ash utilization in concrete because of odor concerns. Although there have been limited studies of ammonia emission from concrete, little is known about the quantity of ammonia emitted during mixing and curing, and the kinetics of ammonia release. This is manifested as widely varying opinions within the concrete and ash marketing industry regarding the maximum acceptable levels of ammonia in fly ash. Therefore, practical guidelines for using ammoniated fly ash are needed in advance of the installation of many more SCR systems. The goal of this project was to develop practical guidelines for the handling and utilization of ammoniated fly ash in concrete, in order to prevent a decrease in the use of fly ash for this application. The objective was to determine the amount of ammonia that is released, over the short- and long-term, from concrete that contains ammoniated fly ash. The technical approach in this project was to measure the release of ammonia from mortar and concrete during mixing, placement, and curing. Work initially focused on laboratory mortar experiments to develop fundamental data on ammonia diffusion characteristics. Larger-scale laboratory experiments were then conducted to study the emission of ammonia from concrete containing ammoniated fly ash. The final phase comprised monitoring ammonia emissions from large concrete slabs. The data indicated that, on average, 15% of the initial ammonia was lost from concrete during 40 minutes of mixing, depending on the mix proportions and batch size. Long-term experiments indicated that ammonia diffusion from concrete was relatively slow, with greater

  6. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    SciTech Connect

    Robert F. Rathbone; Thomas L. Robl

    2002-04-11

    Work completed in this reporting period focused primarily on continuing measurements of the rate of ammonia loss from concrete, and the measurement of ammonia gas in the air above concrete and flowable fill immediately after placement. Concrete slabs were prepared to monitor the loss of ammonia during mixing, the concentration in the airspace above the slabs soon after placement, and the total quantity of ammonia evolved over a longer time period. Variables tested include temperature, ventilation rate, water:cementitious (W:C) ratio, and fly ash source. Short-term data indicate that for concrete placed in areas with poor air ventilation the fly ash NH{sub 3} concentration should not exceed about 90 to 145 mg/kg ash, depending on the water:cement ratio and the fly ash replacement rate, if a concentration of 10 ppm NH{sub 3} in the air is assumed to be the maximum acceptable level. Longer-term experiments showed that the ammonia loss rate is dependent on ammonia source (that is ammoniated ash vs. non-ammoniated ash with ammonia added to the water), and is also dependent on W:C ratio and temperature. Experiments were also conducted to study the loss of ammonia from fresh concrete during mixing. It was found that a high water:cementitious mix lost a greater percentage of ammonia than a low W:C mix, with a medium W:C mix losing an amount intermediate between these two. However, a larger batch size resulted in a smaller percentage of ammonia lost. The data suggest that a significant quantity of ammonia could be lost from Ready Mix concrete during transit, depending on the transit time, batch size, and mix proportions.

  7. Circulating Endocannabinoids and the Polymorphism 385C>A in Fatty Acid Amide Hydrolase (FAAH) Gene May Identify the Obesity Phenotype Related to Cardiometabolic Risk: A Study Conducted in a Brazilian Population of Complex Interethnic Admixture.

    PubMed

    Martins, Cyro José de Moraes; Genelhu, Virginia; Pimentel, Marcia Mattos Gonçalves; Celoria, Bruno Miguel Jorge; Mangia, Rogerio Fabris; Aveta, Teresa; Silvestri, Cristoforo; Di Marzo, Vincenzo; Francischetti, Emilio Antonio

    2015-01-01

    The dysregulation of the endocannabinoid system is associated with cardiometabolic complications of obesity. Allelic variants in coding genes for this system components may contribute to differences in the susceptibility to obesity and related health hazards. These data have mostly been shown in Caucasian populations and in severely obese individuals. We investigated a multiethnic Brazilian population to study the relationships among the polymorphism 385C>A in an endocannabinoid degrading enzyme gene (FAAH), endocannabinoid levels and markers of cardiometabolic risk. Fasting plasma levels of endocannabinoids and congeners (anandamide, 2-arachidonoylglycerol, N-oleoylethanolamide and N-palmitoylethanolamide) were measured by liquid chromatography-mass spectrometry in 200 apparently healthy individuals of both genders with body mass indices from 22.5 ± 1.8 to 35.9 ± 5.5 kg/m2 (mean ± 1 SD) and ages between 18 and 60 years. All were evaluated for anthropometric parameters, blood pressure, metabolic variables, homeostatic model assessment of insulin resistance (HOMA-IR), adiponectin, leptin, C-reactive protein, and genotyping. The endocannabinoid levels increased as a function of obesity and insulin resistance. The homozygous genotype AA was associated with higher levels of anandamide and lower levels of adiponectin versus wild homozygous CC and heterozygotes combined. The levels of anandamide were independent and positively associated with the genotype AA position 385 of FAAH, C-reactive protein levels and body mass index. Our findings provide evidence for an endocannabinoid-related phenotype that may be identified by the combination of circulating anandamide levels with genotyping of the FAAH 385C>A; this phenotype is not exclusive to mono-ethnoracial populations nor to individuals with severe obesity. PMID:26561012

  8. Circulating Endocannabinoids and the Polymorphism 385C>A in Fatty Acid Amide Hydrolase (FAAH) Gene May Identify the Obesity Phenotype Related to Cardiometabolic Risk: A Study Conducted in a Brazilian Population of Complex Interethnic Admixture

    PubMed Central

    Martins, Cyro José de Moraes; Genelhu, Virginia; Pimentel, Marcia Mattos Gonçalves; Celoria, Bruno Miguel Jorge; Mangia, Rogerio Fabris; Aveta, Teresa; Silvestri, Cristoforo; Di Marzo, Vincenzo; Francischetti, Emilio Antonio

    2015-01-01

    The dysregulation of the endocannabinoid system is associated with cardiometabolic complications of obesity. Allelic variants in coding genes for this system components may contribute to differences in the susceptibility to obesity and related health hazards. These data have mostly been shown in Caucasian populations and in severely obese individuals. We investigated a multiethnic Brazilian population to study the relationships among the polymorphism 385C>A in an endocannabinoid degrading enzyme gene (FAAH), endocannabinoid levels and markers of cardiometabolic risk. Fasting plasma levels of endocannabinoids and congeners (anandamide, 2-arachidonoylglycerol, N-oleoylethanolamide and N-palmitoylethanolamide) were measured by liquid chromatography-mass spectrometry in 200 apparently healthy individuals of both genders with body mass indices from 22.5 ± 1.8 to 35.9 ± 5.5 kg/m2 (mean ± 1 SD) and ages between 18 and 60 years. All were evaluated for anthropometric parameters, blood pressure, metabolic variables, homeostatic model assessment of insulin resistance (HOMA-IR), adiponectin, leptin, C-reactive protein, and genotyping. The endocannabinoid levels increased as a function of obesity and insulin resistance. The homozygous genotype AA was associated with higher levels of anandamide and lower levels of adiponectin versus wild homozygous CC and heterozygotes combined. The levels of anandamide were independent and positively associated with the genotype AA position 385 of FAAH, C-reactive protein levels and body mass index. Our findings provide evidence for an endocannabinoid-related phenotype that may be identified by the combination of circulating anandamide levels with genotyping of the FAAH 385C>A; this phenotype is not exclusive to mono-ethnoracial populations nor to individuals with severe obesity. PMID:26561012

  9. Genetic structure of the population of Cabo Verde (west Africa): evidence of substantial European admixture.

    PubMed

    Parra, E J; Ribeiro, J C; Caeiro, J L; Riveiro, A

    1995-08-01

    The population of Cabo Verde was founded in the fifteenth century (1462), on the basis of slaves brought from the West African coast and a few Europeans, mainly from Portugal. The polymorphism of six red cell enzymes (ADA, AK1, ALAD, ESD, GLO1, and PGD) and ten plasma proteins (AHSG, BF, F13A, F13B, GC, HP, ORM, PLG, TBG, and TF) was studied in a sample of 268 individuals from Cabo Verde (West Africa). There is no statistical evidence of genetic heterogeneity between the two groups of islands which constitute the archipelago, Barlavento and Sotavento. The gene frequency distribution observed in Cabo Verde differs, in many markers, from that of West African populations, suggesting an important European influence. The proportion of Caucasian genes in the population of Cabo Verde has been calculated to be M = 0.3634 +/- 0.0510, and the considerable dispersion of the locus-specific admixture estimates seems to indicate random drift has also played a role in the evolution of the allele frequencies in the archipelago. Partition of the variance of the mean estimate in evolutionary and sampling variance shows the evolutionary variance is more than ten times higher than the sampling variance. When dendrograms are constructed on the basis of different genetic distances, the population of Cabo Verde clusters with Afro-Americans, forming a different group from the populations of the African continent. This is interpreted as a consequence of the importance of Caucasian admixture both in Afro-Americans and in the population of Cabo Verde. PMID:7485435

  10. Crises in a driven Josephson junction studied by cell mapping

    SciTech Connect

    Soerensen, M.P.; Davidson, A.; Pedersen, N.F.; Pagano, S.

    1988-11-15

    We use the method of cell-to-cell mapping to locate attractors, basins, and saddle nodes in the phase plane of a driven Josephson junction. The cell-mapping method is discussed in some detail, emphasizing its ability to provide a global view of the phase plane. Our computations confirm the existence of a previously reported interior crisis. In addition, we observe a boundary crisis for a small shift in one parameter. The cell-mapping method allows us to show both crises explicitly in the phase plane, at low computational cost.

  11. A Genome-Wide Search for Greek and Jewish Admixture in the Kashmiri Population

    PubMed Central

    Tashi, Tsewang; Lorenzo, Felipe Ramos; Feusier, Julie Ellen; Mir, Hyder

    2016-01-01

    The Kashmiri population is an ethno-linguistic group that resides in the Kashmir Valley in northern India. A longstanding hypothesis is that this population derives ancestry from Jewish and/or Greek sources. There is historical and archaeological evidence of ancient Greek presence in India and Kashmir. Further, some historical accounts suggest ancient Hebrew ancestry as well. To date, it has not been determined whether signatures of Greek or Jewish admixture can be detected in the Kashmiri population. Using genome-wide genotyping and admixture detection methods, we determined there are no significant or substantial signs of Greek or Jewish admixture in modern-day Kashmiris. The ancestry of Kashmiri Tibetans was also determined, which showed signs of admixture with populations from northern India and west Eurasia. These results contribute to our understanding of the existing population structure in northern India and its surrounding geographical areas. PMID:27490348

  12. Reducing the drying shrinkage of cement paste by admixture surface treatments

    SciTech Connect

    Xu, Y.; Chung, D.D.L.

    2000-02-01

    The drying shrinkage of concrete during curing is a source of residual stress and cracks. The problem is particularly severe for a large structure, such as a large concrete floor. Surface treatment of carbon fibers and/or silica fume by silane prior to using these admixtures in cement paste increases the effectiveness of these admixtures for reducing the drying shrinkage. Silane treatment of fibers is more effective than dichromate treatment or ozone treatment.

  13. Low-frequency resonances of the refractive index in weakly ionized plasma with an admixture of dust

    SciTech Connect

    Prudskikh, V. V.

    2013-12-15

    The propagation of low-frequency electromagnetic waves along the magnetic field in weakly ionized plasma with an admixture of dust is studied in the framework of the Hall magnetohydrodynamics. Explicit expressions for the coefficients of magnetic field diffusion in plasma are derived. The resonance of the refractive index is found to occur for either right- or left-hand polarized waves. A quantitative criterion is obtained that allows one to determine the polarization of waves that experience resonance at given plasma parameters. The physical mechanism of the resonance is discussed, and the obtained results are compared with the available literature data.

  14. Effect of mineral viscosity-enhancing admixtures on the solidification of evaporator concentrates.

    PubMed

    Lin, Chung-Yung; Huang, Wan-Ting

    2015-11-15

    It is known that partial replacement of cement by viscosity-enhancing admixtures, also known as anti-washout admixtures, affects the quality of the waste form or concrete. To reduce the bleeding rate of the paste, the characteristics of various mineral viscosity-enhancing admixtures dispersed in saline solutions were investigated, including sedimentation and viscosity. The admixture candidates included fly ash, silica fume, bentonite, and palygorskite. The effect of these admixtures blended with a cement-based matrix on the bleeding rate of the solidification of evaporator concentrates was also examined in this paper. The experimental results show the palygorskite Type 400 is the best choice to improve the quality of waste form, due to its excellent suspension property in the saline solution. The bleeding rate of paste decreased as the dispersion volume of the admixture suspension increased. For consideration of the quality of waste forms and the concentrate loading, the optimization of the palygorskite/concentrate ratio of 15-17 wt% and solidification agent/concentrate ratio of 1.0-1.2 were adopted. With this recipe, the quality of waste forms resulting from the solidification of simulated and actual evaporator concentrates mainly containing chloride met the regulations' requirements. PMID:26087074

  15. Signatures of founder effects, admixture, and selection in the Ashkenazi Jewish population.

    PubMed

    Bray, Steven M; Mulle, Jennifer G; Dodd, Anne F; Pulver, Ann E; Wooding, Stephen; Warren, Stephen T

    2010-09-14

    The Ashkenazi Jewish (AJ) population has long been viewed as a genetic isolate, yet it is still unclear how population bottlenecks, admixture, or positive selection contribute to its genetic structure. Here we analyzed a large AJ cohort and found higher linkage disequilibrium (LD) and identity-by-descent relative to Europeans, as expected for an isolate. However, paradoxically we also found higher genetic diversity, a sign of an older or more admixed population but not of a long-term isolate. Recent reports have reaffirmed that the AJ population has a common Middle Eastern origin with other Jewish Diaspora populations, but also suggest that the AJ population, compared with other Jews, has had the most European admixture. Our analysis indeed revealed higher European admixture than predicted from previous Y-chromosome analyses. Moreover, we also show that admixture directly correlates with high LD, suggesting that admixture has increased both genetic diversity and LD in the AJ population. Additionally, we applied extended haplotype tests to determine whether positive selection can account for the level of AJ-prevalent diseases. We identified genomic regions under selection that account for lactose and alcohol tolerance, and although we found evidence for positive selection at some AJ-prevalent disease loci, the higher incidence of the majority of these diseases is likely the result of genetic drift following a bottleneck. Thus, the AJ population shows evidence of past founding events; however, admixture and selection have also strongly influenced its current genetic makeup. PMID:20798349

  16. Reconstructing Past Admixture Processes from Local Genomic Ancestry Using Wavelet Transformation

    PubMed Central

    Sanderson, Jean; Sudoyo, Herawati; Karafet, Tatiana M.; Hammer, Michael F.; Cox, Murray P.

    2015-01-01

    Admixture between long-separated populations is a defining feature of the genomes of many species. The mosaic block structure of admixed genomes can provide information about past contact events, including the time and extent of admixture. Here, we describe an improved wavelet-based technique that better characterizes ancestry block structure from observed genomic patterns. principal components analysis is first applied to genomic data to identify the primary population structure, followed by wavelet decomposition to develop a new characterization of local ancestry information along the chromosomes. For testing purposes, this method is applied to human genome-wide genotype data from Indonesia, as well as virtual genetic data generated using genome-scale sequential coalescent simulations under a wide range of admixture scenarios. Time of admixture is inferred using an approximate Bayesian computation framework, providing robust estimates of both admixture times and their associated levels of uncertainty. Crucially, we demonstrate that this revised wavelet approach, which we have released as the R package adwave, provides improved statistical power over existing wavelet-based techniques and can be used to address a broad range of admixture questions. PMID:25852078

  17. Reconstructing Past Admixture Processes from Local Genomic Ancestry Using Wavelet Transformation.

    PubMed

    Sanderson, Jean; Sudoyo, Herawati; Karafet, Tatiana M; Hammer, Michael F; Cox, Murray P

    2015-06-01

    Admixture between long-separated populations is a defining feature of the genomes of many species. The mosaic block structure of admixed genomes can provide information about past contact events, including the time and extent of admixture. Here, we describe an improved wavelet-based technique that better characterizes ancestry block structure from observed genomic patterns. principal components analysis is first applied to genomic data to identify the primary population structure, followed by wavelet decomposition to develop a new characterization of local ancestry information along the chromosomes. For testing purposes, this method is applied to human genome-wide genotype data from Indonesia, as well as virtual genetic data generated using genome-scale sequential coalescent simulations under a wide range of admixture scenarios. Time of admixture is inferred using an approximate Bayesian computation framework, providing robust estimates of both admixture times and their associated levels of uncertainty. Crucially, we demonstrate that this revised wavelet approach, which we have released as the R package adwave, provides improved statistical power over existing wavelet-based techniques and can be used to address a broad range of admixture questions. PMID:25852078

  18. The Full-sky Astrometric Mapping Explorer Concept Study

    NASA Astrophysics Data System (ADS)

    Horner, S. D.; Germain, M. E.; Greene, T. P.; Harris, F. H.; Johnson, M. S.; Johnston, K. J.; Monet, D. G.; Murison, M. A.; Phillips, J. D.; Reasenberg, R. D.; Seidelmann, P. K.; Talabac, S. J.; Urban, S. E.; van Buren, D.; Vassar, R. H.

    1999-05-01

    NASA has selected the Full-sky Astrometric Mapping Explorer (FAME) to be one of five MIDEX missions to be funded for a concept study. This concept study will be submitted to NASA on 18 June, with final selection, scheduled for September, of two of these missions for flight in 2003 or 2004. FAME is designed to perform an all-sky, astrometric survey with unprecedented accuracy. It will create a rigid astrometric catalog of 40,000,000 stars with visual band magnitudes 5 < V < 15. For bright stars, 5 < V < 9, FAME will determine positions and parallaxes accurate to < 50 microarcseconds, with proper motion errors < 50 microarcseconds/year. For fainter stars, 9 < V < 15, FAME will determine positions and parallaxes accurate to < 300 microarcseconds, with proper motion errors < 300 microarcseconds/year. FAME will also collect photometric data on these 40,000,000 stars in four Sloan DSS colors. During the concept study, the team has worked to optimize the scientific return from FAME while minimizing cost and risk. The optical design was modified for improved accuracy of individual observations and improved mechanical design. The optical, mechanical, and thermal design of the instrument have been improved. Tests using CCDs in TDI mode are being conducted to confirm the accuracy obtainable from individual observations as well as determine the optimal clocking scheme for astrometric devices operated in TDI mode. The use of solar radiation pressure for spacecraft precession has undergone further feasibility study, as have the mechanisms for deploying the solar shield. Numerous other trade studies have been conducted, including orbit/communications, on board processing, and the use of neutral density filters for astrometry of bright stars versus other options. A detailed error budget has been formulated and the mission requirements have been defined. We look forward to selection for launch and a successful FAME mission that will redefine the extragalactic distance scale and

  19. Research Map of Research Priorities in HE Studies in the Kingdom of Saudi Arabia

    ERIC Educational Resources Information Center

    AlSumih, A. M.

    2016-01-01

    This study presents a research map for the key research priorities of higher education (HE) in the Kingdom of Saudi Arabia. The study diagnoses and analyzes the research reality in HE studies in KSA in terms of strength points and improvement opportunities. It also explores the research map fields of current and prospective research priorities in…

  20. Snow mapping and land use studies in Switzerland

    NASA Technical Reports Server (NTRS)

    Haefner, H. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. A system was developed for operational snow and land use mapping, based on a supervised classification method using various classification algorithms and representation of the results in maplike form on color film with a photomation system. Land use mapping, under European conditions, was achieved with a stepwise linear discriminant analysis by using additional ratio variables. On fall images, signatures of built-up areas were often not separable from wetlands. Two different methods were tested to correlate the size of settlements and the population with an accuracy for the densely populated Swiss Plateau between +2 or -12%.

  1. The Highway Map as a Social Studies Resource

    ERIC Educational Resources Information Center

    Ehemann, Jane

    1977-01-01

    This learning exercise was designed for a seventh grade geography class in Western Pennsylvania using highway maps from a local service station. It is designed to provide practice in skills in using the key, the grid system, the mileage scale for finding distances, and to develop an appreciation for the variety of information a student can obtain…

  2. Porcine NAMPT gene: search for polymorphism, mapping and association studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NAMPT encodes for an enzyme catalysing the rate-limiting step in NAD biosynthesis. The extracellular form of the enzyme is known as adipokine visfatin. We detected SNP AM999341:g.669T>C in intron 9 and SNP FN392209:g.358A>G in the promoter of the gene. RH mapping linked the gene to microsatellite SW...

  3. Mapping Knowledge Perspectives in Studies of Educational Change.

    ERIC Educational Resources Information Center

    Paulston, Rolland G.

    This document argues for the utility of mapping knowledge perspectives as a kind of cognitive art, or play of figuration to help orient educators to knowledge communities and their cultural codes, and to reinscribe modernist vocabularies into post-modern ways of seeing and representing educational change knowledge. A perspectivist approach is used…

  4. Age-Related Weakness of Proximal Muscle Studied with Motor Cortical Mapping: A TMS Study

    PubMed Central

    Plow, Ela B.; Varnerin, Nicole; Cunningham, David A.; Janini, Daniel; Bonnett, Corin; Wyant, Alexandria; Hou, Juliet; Siemionow, Vlodek; Wang, Xiao-Feng; Machado, Andre G.; Yue, Guang H.

    2014-01-01

    Aging-related weakness is due in part to degeneration within the central nervous system. However, it is unknown how changes to the representation of corticospinal output in the primary motor cortex (M1) relate to such weakness. Transcranial magnetic stimulation (TMS) is a noninvasive method of cortical stimulation that can map representation of corticospinal output devoted to a muscle. Using TMS, we examined age-related alterations in maps devoted to biceps brachii muscle to determine whether they predicted its age-induced weakness. Forty-seven right-handed subjects participated: 20 young (22.6±0.90 years) and 27 old (74.96±1.35 years). We measured strength as force of elbow flexion and electromyographic activation of biceps brachii during maximum voluntary contraction. Mapping variables included: 1) center of gravity or weighted mean location of corticospinal output, 2) size of map, 3) volume or excitation of corticospinal output, and 4) response density or corticospinal excitation per unit area. Center of gravity was more anterior in old than in young (p<0.001), though there was no significant difference in strength between the age groups. Map size, volume, and response density showed no significant difference between groups. Regardless of age, center of gravity significantly predicted strength (β = −0.34, p = 0.005), while volume adjacent to the core of map predicted voluntary activation of biceps (β = 0.32, p = 0.008). Overall, the anterior shift of the map in older adults may reflect an adaptive change that allowed for the maintenance of strength. Laterally located center of gravity and higher excitation in the region adjacent to the core in weaker individuals could reflect compensatory recruitment of synergistic muscles. Thus, our study substantiates the role of M1 in adapting to aging-related weakness and subtending strength and muscle activation across age groups. Mapping from M1 may offer foundation for an examination of mechanisms

  5. An Improved Approach for Mapping Quantitative Trait loci in a Pseudo-Testcross: Revisiting a Poplar Mapping Study

    SciTech Connect

    Wullschleger, Stan D; Wu, Song; Wu, Rongling; Yang, Jie; Li, Yao; Yin, Tongming; Tuskan, Gerald A

    2010-01-01

    A pseudo-testcross pedigree is widely used for mapping quantitative trait loci (QTL) in outcrossing species, but the model for analyzing pseudo-testcross data borrowed from the inbred backcross design can only detect those QTLs that are heterozygous only in one parent. In this study, an intercross model that incorporates the high heterozygosity and phase uncertainty of outcrossing species was used to reanalyze a published data set on QTL mapping in poplar trees. Several intercross QTLs that are heterozygous in both parents were detected, which are responsible not only for biomass traits, but also for their genetic correlations. This study provides a more complete identification of QTLs responsible for economically important biomass traits in poplars.

  6. An Improved Approach for Mapping Quantitative Trait Loci in a Pseudo-Testcross: Revisiting a Poplar Mapping Study

    SciTech Connect

    Tuskan, Gerald A; Yin, Tongming; Wullschleger, Stan D; Yang, Jie; Huang, Youjun; Li, Yao; Wu, Rongling

    2010-01-01

    A pseudo-testcross pedigree is widely used for mapping quantitative trait loci (QTL) in outcrossing species, but the model for analyzing pseudo-testcross data borrowed from the inbred backcross design can only detect those QTLs that are heterozygous only in one parent. In this study, an intercross model that incorporates the high heterozygosity and phase uncertainty of outcrossing species was used to reanalyze a published data set on QTL mapping in poplar trees. Several intercross QTLs that are heterozygous in both parents were detected, which are responsible not only for biomass traits, but also for their genetic correlations. This study provides a more complete identification of QTLs responsible for economically important biomass traits in poplars.

  7. Using Digital Mapping Programs to Augment Student Learning in Social Studies

    ERIC Educational Resources Information Center

    Chandler, Thomas; An, Heejung

    2007-01-01

    Thomas Chandler and Heejung An describe how digital mapping technology can be incorporated into community-based K-12 social studies projects. According to Chandler and An, digital mapping can add value to the social studies curriculum by enabling students to better understand the interdependence between the lives of individuals and their…

  8. Inferring separate parental admixture components in unknown DNA samples using autosomal SNPs.

    PubMed

    Crouch, Daniel J M; Weale, Michael E

    2012-12-01

    The identification of ancestral admixture proportions for human DNA samples has recently had success in forensic cases. Current methods infer admixture proportions for the target sample, but not for their parents, which provides an additional layer of information that may aid certain forensic investigations. We describe new maximum likelihood methods (LEAPFrOG and LEAPFrOG Expectation Maximisation), for inferring both an individual's admixture proportions and the admixture proportions possessed by the unobserved parents, with respect to two or more source populations, using single-nucleotide polymorphism data typed only in the target individual. This is achieved by examining the increase in heterozygosity in the offspring of parents who are from different populations or who represent different mixtures from a number of source populations. We validated the methods via simulation; combining chromosomes from different Hapmap Phase III population samples to emulate first-generation admixture. Performance was strong for individuals with mixed African/European (YRI/CEU) ancestry, but poor for mixed Japanese/Chinese (JPT/CHB) ancestry, reflecting the difficulty in distinguishing closely related source populations. A total of 11 African-American trios were used to compare the parental admixture inferred from their own genotypes against that inferred purely from their offspring genotypes. We examined the performance of 34 ancestry informative markers from a multiplex kit for ancestry inference. Simulations showed that estimates were unreliable when parents had similar admixture, suggesting more markers are needed. Our results demonstrate that ancestral backgrounds of case samples and their parents are obtainable to aid in forensic investigations, provided that high-throughput methods are adopted by the forensic community. PMID:22739346

  9. Relaxed energetic maps of kappa-carrabiose: a DFT study.

    PubMed

    Yousfi, N; Sekkal-Rahal, M; Sayede, A; Springborg, M

    2010-04-30

    The B3LYP density function was used with the 6-31G(d) basis set to perform relaxed energetic contour maps of the charged form of kappa-carrabiose in the gas phase and for the neutral form first in the gas phase and then by simulating the presence of water as solvent using the Onsager model. Only one starting conformation has been considered to perform all the calculations. Rigid energetic maps have been then constructed either by addition of diffuse or polarization functions to the basis set obtaining in that way 6-31+G(d)//6-31G(d), 6-31+G(d,p)//6-31G(d), and 6-311++G(d,p)//6-31G(d) energetic maps that have been carefully examined. The obtained structures corresponding to the lower energy conformers have been then fully optimized using different basis sets with the B3LYP method, a reversion in term of energy has been observed for the two first minima in the case of the charged disaccharide in the gas phase, this was attributed to the large grid of 30 degrees that could lead to the exclusion of an intermediate value corresponding to the real minimum of energy. We thus suggest that after establishing potential energy maps it is essential to proceed to full optimizations of the lower energy conformers. Calculations using the more accurate correlated method MP2 with the 6-31G(d) basis set have also been performed for conformers of the two disaccharides in the gas phase. PMID:20127880

  10. Active Mapping.

    ERIC Educational Resources Information Center

    Day, Dennis

    1994-01-01

    Explains a social studies lesson for third graders that uses KidPix, a computer software graphics program to help students make maps and map keys. Advantages to using the computer versus hand drawing maps are discussed, and an example of map requirements for the lesson is included. (LRW)

  11. Mechanical characteristics of hardened concrete with different mineral admixtures: a review.

    PubMed

    Ayub, Tehmina; Khan, Sadaqat Ullah; Memon, Fareed Ahmed

    2014-01-01

    The available literature identifies that the addition of mineral admixture as partial replacement of cement improves the microstructure of the concrete (i.e., porosity and pore size distribution) as well as increasing the mechanical characteristics such as drying shrinkage and creep, compressive strength, tensile strength, flexural strength, and modulus of elasticity; however, no single document is available in which review and comparison of the influence of the addition of these mineral admixtures on the mechanical characteristics of the hardened pozzolanic concretes are presented. In this paper, based on the reported results in the literature, mechanical characteristics of hardened concrete partially containing mineral admixtures including fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA) are discussed and it is concluded that the content and particle size of mineral admixture are the parameters which significantly influence the mechanical properties of concrete. All mineral admixtures enhance the mechanical properties of concrete except FA and GGBS which do not show a significant effect on the strength of concrete at 28 days; however, gain in strength at later ages is considerable. Moreover, the comparison of the mechanical characteristics of different pozzolanic concretes suggests that RHA and SF are competitive. PMID:24688443

  12. Mechanical Characteristics of Hardened Concrete with Different Mineral Admixtures: A Review

    PubMed Central

    2014-01-01

    The available literature identifies that the addition of mineral admixture as partial replacement of cement improves the microstructure of the concrete (i.e., porosity and pore size distribution) as well as increasing the mechanical characteristics such as drying shrinkage and creep, compressive strength, tensile strength, flexural strength, and modulus of elasticity; however, no single document is available in which review and comparison of the influence of the addition of these mineral admixtures on the mechanical characteristics of the hardened pozzolanic concretes are presented. In this paper, based on the reported results in the literature, mechanical characteristics of hardened concrete partially containing mineral admixtures including fly ash (FA), silica fume (SF), ground granulated blast furnace slag (GGBS), metakaolin (MK), and rice husk ash (RHA) are discussed and it is concluded that the content and particle size of mineral admixture are the parameters which significantly influence the mechanical properties of concrete. All mineral admixtures enhance the mechanical properties of concrete except FA and GGBS which do not show a significant effect on the strength of concrete at 28 days; however, gain in strength at later ages is considerable. Moreover, the comparison of the mechanical characteristics of different pozzolanic concretes suggests that RHA and SF are competitive. PMID:24688443

  13. Admixture in Latin America: Geographic Structure, Phenotypic Diversity and Self-Perception of Ancestry Based on 7,342 Individuals

    PubMed Central

    Ruiz-Linares, Andrés; Adhikari, Kaustubh; Acuña-Alonzo, Victor; Quinto-Sanchez, Mirsha; Jaramillo, Claudia; Arias, William; Fuentes, Macarena; Pizarro, María; Everardo, Paola; de Avila, Francisco; Gómez-Valdés, Jorge; León-Mimila, Paola; Hunemeier, Tábita; Ramallo, Virginia; Silva de Cerqueira, Caio C.; Burley, Mari-Wyn; Konca, Esra; de Oliveira, Marcelo Zagonel; Veronez, Mauricio Roberto; Rubio-Codina, Marta; Attanasio, Orazio; Gibbon, Sahra; Ray, Nicolas; Gallo, Carla; Poletti, Giovanni; Rosique, Javier; Schuler-Faccini, Lavinia; Salzano, Francisco M.; Bortolini, Maria-Cátira; Canizales-Quinteros, Samuel; Rothhammer, Francisco; Bedoya, Gabriel; Balding, David; Gonzalez-José, Rolando

    2014-01-01

    The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry. PMID:25254375

  14. Admixture in Latin America: geographic structure, phenotypic diversity and self-perception of ancestry based on 7,342 individuals.

    PubMed

    Ruiz-Linares, Andrés; Adhikari, Kaustubh; Acuña-Alonzo, Victor; Quinto-Sanchez, Mirsha; Jaramillo, Claudia; Arias, William; Fuentes, Macarena; Pizarro, María; Everardo, Paola; de Avila, Francisco; Gómez-Valdés, Jorge; León-Mimila, Paola; Hunemeier, Tábita; Ramallo, Virginia; Silva de Cerqueira, Caio C; Burley, Mari-Wyn; Konca, Esra; de Oliveira, Marcelo Zagonel; Veronez, Mauricio Roberto; Rubio-Codina, Marta; Attanasio, Orazio; Gibbon, Sahra; Ray, Nicolas; Gallo, Carla; Poletti, Giovanni; Rosique, Javier; Schuler-Faccini, Lavinia; Salzano, Francisco M; Bortolini, Maria-Cátira; Canizales-Quinteros, Samuel; Rothhammer, Francisco; Bedoya, Gabriel; Balding, David; Gonzalez-José, Rolando

    2014-09-01

    The current genetic makeup of Latin America has been shaped by a history of extensive admixture between Africans, Europeans and Native Americans, a process taking place within the context of extensive geographic and social stratification. We estimated individual ancestry proportions in a sample of 7,342 subjects ascertained in five countries (Brazil, Chile, Colombia, México and Perú). These individuals were also characterized for a range of physical appearance traits and for self-perception of ancestry. The geographic distribution of admixture proportions in this sample reveals extensive population structure, illustrating the continuing impact of demographic history on the genetic diversity of Latin America. Significant ancestry effects were detected for most phenotypes studied. However, ancestry generally explains only a modest proportion of total phenotypic variation. Genetically estimated and self-perceived ancestry correlate significantly, but certain physical attributes have a strong impact on self-perception and bias self-perception of ancestry relative to genetically estimated ancestry. PMID:25254375

  15. Winning the invasion roulette: escapes from fish farms increase admixture and facilitate establishment of non-native rainbow trout

    PubMed Central

    Consuegra, Sofia; Phillips, Nia; Gajardo, Gonzalo; de Leaniz, Carlos Garcia

    2011-01-01

    Aquaculture is a major source of invasive aquatic species, despite the fact that cultured organisms often have low genetic diversity and tend to be maladapted to survive in the wild. Yet, to what extent aquaculture escapees become established by means of high propagule pressure and multiple origins is not clear. We analysed the genetic diversity of 15 established populations and four farmed stocks of non-native rainbow trout in Chile, a species first introduced for recreational fishing around 1900, but which has in recent decades escaped in large numbers from fish farms and become widespread. Aquaculture propagule pressure was a good predictor of the incidence of farm escapees, which represented 16% of all free-ranging rainbow trout and were present in 80% of the study rivers. Hybrids between farm escapes and established trout were present in all rivers at frequencies ranging between 7 and 69%, and population admixture was positively correlated with genetic diversity. We suggest that non-native salmonids introduced into the Southern Hemisphere could benefit from admixture because local adaptations may not have yet developed, and there may be initially little fitness loss resulting from outbreeding depression. PMID:25568013

  16. An Adult Education Study of Participatory Community Mapping for Indigenous Knowledge Production

    ERIC Educational Resources Information Center

    Campbell, Craig A., Jr.

    2010-01-01

    This dissertation explores the notion of participatory community mapping (PCM) for Indigenous knowledge production. Three major questions were posed in the study. First, how can PCM foster Indigenous knowledge production and documentation? Second, how can PCM be used to include local voice and input in mapping projects, and third, how can adult…

  17. Preservice Teachers Map Compassion: Connecting Social Studies and Literacy through Nonfictional Animal Stories

    ERIC Educational Resources Information Center

    Rule, Audrey C.; Montgomery, Sarah E.; Vander Zanden, Sarah M.

    2014-01-01

    Nonfiction stories of animal compassion were used in this literacy-social studies integrated lesson to address both efferent and aesthetic stances in transmediation of text from picture books to maps. Preservice early childhood and elementary teachers chose places from the nine recent children's stories, symbolizing them on a map while…

  18. Investigating Word Learning in Fragile X Syndrome: A Fast-Mapping Study

    ERIC Educational Resources Information Center

    McDuffie, Andrea; Kover, Sara T.; Hagerman, Randi; Abbeduto, Leonard

    2013-01-01

    Fast-mapping paradigms have not been used previously to examine the process of word learning in boys with fragile X syndrome (FXS), who are likely to have intellectual impairment, language delays, and symptoms of autism. In this study, a fast-mapping task was used to investigate associative word learning in 4- to 10-year-old boys with FXS relative…

  19. An Exploratory Study of Elementary Preservice Teachers' Understanding of Ecology Using Concept Maps

    ERIC Educational Resources Information Center

    Zak, Kevin M.; Munson, Bruce H.

    2008-01-01

    Classroom teachers serve a critical role in developing environmentally literate citizens. In this study, the authors assessed K-8 preservice teachers' understanding of basic ecological concepts. Participants (N = 56) constructed concept maps describing the inter-relationships among 16 ecological concepts. The authors analyzed the concept maps to…

  20. iMindMap as an Innovative Tool in Teaching and Learning Accounting: An Exploratory Study

    ERIC Educational Resources Information Center

    Wan Jusoh, Wan Noor Hazlina; Ahmad, Suraya

    2016-01-01

    Purpose: The purpose of this study is to explore the use of iMindMap software as an interactive tool in the teaching and learning method and also to be able to consider iMindMap as an alternative instrument in achieving the ultimate learning outcome. Design/Methodology/Approach: Out of 268 students of the management accounting at the University of…

  1. Pedagogical Knowledge Representation through Concept Mapping as a Study and Collaboration Tool in Teacher Education

    ERIC Educational Resources Information Center

    Koc, Mustafa

    2012-01-01

    This study explored (a) pre-service teachers' perceptions of using concept mapping (CM) in one of their pedagogical courses, (b) the predictive power of such implementation in course achievement, and (c) the role of prior experience with CM, type of mapping, and gender on their perceptions and performances in CM and achievement. The subjects were…

  2. Mapping Civic Engagement: A Case Study of Service-Learning in Appalachia

    ERIC Educational Resources Information Center

    Mann, Jessica; Casebeer, Daniel

    2016-01-01

    This study uses social cartography to map student perceptions of a co-curricular service-learning project in an impoverished rural community. As a complement to narrative discourse, mapping provides an opportunity to visualize not only the spatial nature of the educational experience but also, in this case, the benefits of civic engagement. The…

  3. Using Concept Maps to Elicit and Study Student Teachers' Perceptions about Inclusive Education: A Tanzanian Experience

    ERIC Educational Resources Information Center

    Wormnaes, Siri; Mkumbo, Kitila; Skaar, Bjørn; Refseth, Yngve

    2015-01-01

    In this study, concept map activities were used to trigger group discussions about inclusive education, with a focus on learners with disabilities. The participants were 226 Tanzanian student teachers. This article reports and discusses how the maps were analysed and what they indicate about the students' thinking about certain aspects of…

  4. Use of admixtures in organic-contaminated cement-clay pastes.

    PubMed

    Gallo Stampino, Paola; Zampori, Luca; Dotelli, Giovanni; Meloni, Paola; Sora, Isabella Natali; Pelosato, Renato

    2009-01-30

    In this work microstructure, porosity and hydration degree of cement-based solidified/stabilized wasteforms were studied before assessing their leaching behaviour. 2-Chloroaniline was chosen as a model liquid organic pollutant and included into cement pastes, which were also modified with different admixtures for concrete: a superplasticizer based on acrylic-modified polymer, a synthetic rubber latex and a waterproofing agent. An organoclay, modified with an ammonium quaternary salt (benzyl-dimethyl-tallowammonium, BDMTA), was added to the pastes as pre-sorbent agent of the organic matter. All the samples were dried up to constant weight in order to stop the hydration process at different times during the first 28 days of curing, typically, after 1 day (1d), 7 days (7d) and 28 days. Then, the microstructure of the hardened cement-clay pastes was investigated by powder X-ray diffraction (XRD). The hydration degree and porosity were studied by thermal analysis (TG/DTA) and mercury intrusion porosimetry (MIP), respectively. For samples cured for 28 days a short-term leach test set by Italian regulation for industrial waste recycling (D.M. 5 February 1998) was performed. The best results showed a 5% release of the total initial amount of organic pollutant. PMID:18514398

  5. Mapping geomorphological diversity. A case study in Derborence (Valais, Swiss Alps)

    NASA Astrophysics Data System (ADS)

    Maret, Hélène; Reynard, Emmanuel

    2015-04-01

    "Geodiversity is the natural range (diversity) of geological (rocks, minerals, fossils), geomorphological (landforms, processes) and soils features. It includes their assemblages, relationships, properties, interpretations and systems." (Gray, 2004: 6). Geodiversity has a strong spatial component and cartography is one good tool to characterize it. In this work, we focus on the geomorphological diversity defined as one part of geodiversity. The aim of this study is to assess geomorphological diversity based on a geomorphological map. A method was then developed to transform the latter into a map of geomorphological diversity. In other words, we transformed a qualitative geomorphological map (morphogenetic map) into a quantitative map (including the value of a geomorphological diversity index). The University of Lausanne has recently developed a geomorphological mapping legend on ArcGIS (Lambiel et al., in press). This system classifies the landforms according to various morphogenetical contexts (glacial, periglacial, fluvial, karstic, etc.). Each form is represented as a surface (e.g. alluvial fan), a line (e.g. moraine) or a dot (e.g. spring, sinkhole). As the geomorphological mapping legend was basically developed for graphical purposes, a first step was to transform the geomorphological map into a map only filled with polygons in order to delimitate precisely areas occupied by points and lines elements (for example rivers or holes). After that, a grid was added to compute the geomorphological diversity by counting the number of elements per square. It results in a raster map with a geomorphological diversity index split into five categories (very high, high, medium, low, very low). We also tested which square size was the most accurate for our purpose and checked whether this index produced interesting results. This attempt to define and test a new methodology for assessing geomorphological diversity could afterward be used to transform other maps (geology

  6. The peopling of São Tomé (Gulf of Guinea): origins of slave settlers and admixture with the Portuguese.

    PubMed

    Tomás, Gil; Seco, Luísa; Seixas, Susana; Faustino, Paula; Lavinha, João; Rocha, Jorge

    2002-06-01

    The geographic origins of African slave settlers and the Portuguese genetic contribution to the population of São Tomé (Gulf of Guinea) were assessed through the analysis of beta-globin haplotypes in 44 chromosomes bearing the betaS allele and through the study of the genetic variation in eight autosomal markers (APOA1, AT3, FY, LPL, OCA2, RB1, Sb19.3, and GC) informative for admixture in a sample of 224 individuals. The observed betaS haplotype distribution (36.4% Bantu, 52.3% Benin, 4.5% Cameroon, 4.5% Senegal, and 2.3% atypical) is in accordance with the historical information on the major geographic sources of slave settlers of São Tomé, although it captures a more important contribution of Central-West Africa regions than previously anticipated. European admixture, estimated to be 10.7 +/- 0.9%, has created a considerable level of genetic structure, as indicated by the finding of significant linkage disequilibrium between 33% of unlinked marker loci pairs. Recent admixture was found to have an important contribution to these values, since removal of individuals with Portuguese or Cape Verdian parents or grandparents from the sample dropped the miscegenation level to 6.5 +/- 0.8% and reduced significant linkage disequilibrium to 11% of unlinked marker pairs. Taken together, these results indicate that the peopling of São Tomé might have provided one of the first examples of the combination of diverse African contributions and European admixture that emerged from the overseas population relocations promoted by the Atlantic slave trade. PMID:12180763

  7. Hydrothermal Alteration Mapping Studies for Geothermal Energy Exploration

    NASA Astrophysics Data System (ADS)

    Calvin, W. M.; Kratt, C.; Littlefield, E. F.; Lamb, A. K.

    2011-12-01

    We use a combination of satellite and aerial surveys at varying spatial resolutions to obtain regional information on hydrothermal alteration patterns and to target more expensive, but also more detailed, airborne spectral data collects. In the past decade we have performed numerous site assessments to characterize mineral, vegetation, and thermal properties as surface identifiers of geothermal resources. Our work has included the satellite sensors Landsat, ASTER, and ALI and airborne sensors MASTER, HyMap, ProSpecTIR, AVIRIS and SEBASS. As part of our validation process we collect data in the field to confirm remote identifications and we also collect samples for later laboratory analysis. These field and lab measurements corroborate our detections and help to define confidence limits in refining regions where alteration minerals are found. Validation work includes the use of an ASD field spectrometer for measurement from 0.4 to 2.5 μm in both field and lab configurations. We have a Thermo/Nicolet Nexus 6700 FTIR spectrometer and shared use of a Designs and Prototypes FTIR field instrument for validation in the thermal infrared spectral range. We usually follow remote sensing work with shallow (2m) ground probe temperature measurements. Past work has identified sinter, tufa, various argillic and propyllitic alteration zones, vegetation concentration near small surface seeps or springs, and thermal anomalies as indicative of resource potential and structural controls on fluid pathways. Playa evaporites have also been used as diagnostic indicators of geothermal systems, where thermal springs discharge into closed basins. Mapped imagery is geo-rectified to standard projections and integrated into GIS databases so that mineral maps can be readily included in regional and site specific assessments. The presentation will describe common and unique features in our surveys of geothermal fields in Nevada as outlined in the table.
    Surveyed Geothermal Sites in Nevada

  8. The "frontal syndrome" revisited: lessons from electrostimulation mapping studies.

    PubMed

    Duffau, Hugues

    2012-01-01

    For a long time, in a localizationist view of brain functioning, a combination of symptoms called "frontal syndrome" has been interpreted as the direct result of damages involving the frontal lobe(s). The goal of this review is to challenge this view, that is, to move to a hodotopical approach to lesion mapping, on the basis of new insights provided by intraoperative electrostimulation mapping investigations in patients who underwent awake surgery for cerebral tumors. These original data reported in the last decade break with the traditional dogma of a modular and fixed organization of the central nervous system, by switching to the concepts of cerebral connectivity and plasticity - i.e., a brain organization based on dynamic interrelationships between parallel distributed networks. According to this revisited model, "frontal symptoms" can be generated by tumor or electrostimulation not only of the frontal lobes, but also of cortical and subcortical (white matter pathways/deep gray nuclei) structures outside the frontal lobes: especially, stimulation of the superior longitudinal fascicle may elicit speech production disorders, syntactic disturbances, involuntary language switching or phonemic paraphasia (arcuate fascicle), stimulation of the inferior fronto-occipital fascicle can generate semantic paraphasia or deficit of cross-modal judgment, stimulation of the subcallosal fasciculus may elicit transcortical motor aphasia, while stimulation of the striatum induces preservations. On the other hand, it is also possible to perform extensive right or left frontal lobectomy in patients who continue to have a normal familial, social and professional life, without "frontal syndrome". Therefore, this provocative approach may open the door to a renewal in the modeling of brain processing as well as in its clinical applications, especially in the fields of cerebral surgery and functional rehabilitation. These findings illustrate well the need to reinforce links between

  9. Analysis of genetic admixture in Uyghur using the 26 Y-STR loci system

    PubMed Central

    Bian, Yingnan; Zhang, Suhua; Zhou, Wei; Zhao, Qi; Siqintuya; Zhu, Ruxin; Wang, Zheng; Gao, Yuzhen; Hong, Jie; Lu, Daru; Li, Chengtao

    2016-01-01

    The Uyghur population has experienced extensive interaction with European and Eastern Asian populations historically. A set of high-resolution genetic markers could be useful to infer the genetic relationships between the Uyghur population and European and Asian populations. In this study we typed 100 unrelated Uyghur males living in southern Xinjiang at 26 Y-STR loci. Using the high-resolution 26 Y-STR loci system, we investigated genetic and phylogenetic relationship between the Uyghur population and 23 reference European or Asian populations. We found that the Uyghur population exhibited a genetic admixture of Eastern Asian and European populations, and had a slightly closer relationship with the selected European populations than the Eastern Asian populations. We also demonstrated that the 26 Y-STR loci system was potentially useful in forensic sciences because it has a large power of discrimination and rarely exhibits common haplotypes. However, ancestry inference of Uyghur samples could be challenging due to the admixed nature of the population. PMID:26842947

  10. Performance of rice husk ash produced using a new technology as a mineral admixture in concrete

    SciTech Connect

    Nehdi, M.; Duquette, J.; El Damatty, A

    2003-08-01

    This article investigates the use of a new technique for the controlled combustion of Egyptian rice husk to mitigate the environmental concerns associated with its uncontrolled burning and provide a supplementary cementing material for the local construction industry. The reactor used provides efficient combustion of rice husk in a short residency time via the suspension of processed particles by jets of a process air stream that is forced though stationary angled blades at high velocity. Investigations on the rice husk ash (RHA) thus produced included oxide analysis, X-ray diffraction, carbon content, grindability, water demand, pozzolanic activity index, surface area, and particle size distribution measurements. In addition, concrete mixtures incorporating various proportions of silica fume (SF) and Egyptian RHA (EG-RHA) produced at different combustion temperatures were made and compared. The workability, superplasticizer and air-entraining admixture requirements, and compressive strength at various ages of these concrete mixtures were evaluated, and their resistance to rapid chloride penetrability and deicing salt surface scaling were examined. Test results indicate that contrary to RHA produced using existing technology, the superplasticizer and air-entraining agent requirements did not increase drastically when the RHA developed in this study was used. Compressive strengths achieved by concrete mixtures incorporating the new RHA exceeded those of concretes containing similar proportions of SF. The resistance to surface scaling of RHA concrete was better than that of concrete containing similar proportions of SF. While the chloride penetrability was substantially decreased by RHA, it remained slightly higher than that achieved by SF concrete.

  11. Utilization of water-reducing admixtures in cemented paste backfill of sulphide-rich mill tailings.

    PubMed

    Ercikdi, Bayram; Cihangir, Ferdi; Kesimal, Ayhan; Deveci, Haci; Alp, Ibrahim

    2010-07-15

    This study presents the effect of three different water-reducing admixtures (WRAs) on the rheological and mechanical properties of cemented paste backfill (CPB) samples. A 28-day strength of > or = 0.7 MPa and the maintenance of the stability (i.e. > or = 0.7 MPa) over 360 days of curing were desired as the design criteria. Ordinary Portland cement (OPC) and Portland composite cement (PCC) were used as binders at 5 wt.% dose. WRAs were initially tested to determine the dosage of a WRA for a required consistency of 7'' for CPB mixtures. A total of 192 CPB samples were then prepared using WRAs. The utilization of WRAs enhanced the flow characteristics of the CPB mixture and allowed to achieve the same consistency at a lower water-to-cement ratio. For OPC, the addition of WRAs appeared to improve the both short- and long-term performance of CPB samples. However, only polycarboxylate-based superplasticiser produced the desired 28-day strength of > or = 0.7 MPa when PCC was used as the binder. These findings suggest that WRAs can be suitably exploited for CPB of sulphide-rich tailings to improve the strength and stability in short and long terms allowing to reduce binder costs in a CPB plant. PMID:20382473

  12. Admixture between native and invasive populations may increase invasiveness of Mimulus guttatus.

    PubMed

    van Kleunen, Mark; Röckle, Michael; Stift, Marc

    2015-09-22

    Self-fertilization and admixture of genotypes from different populations can have major fitness consequences in native species. However, few studies have addressed their potential roles in invasive species. Here, we used plants of Mimulus guttatus from seven native North American, three invasive Scottish and four invasive New Zealand populations to address this. We created seeds from self-fertilization, within-population outcrossing, between-population outcrossing within the same range, and outcrossing between the native and invasive ranges. A greenhouse experiment showed that native and invasive plants of M. guttatus suffered to similar degrees from inbreeding depression, in terms of asexual reproduction and biomass production. After outcrossing with plants from other populations, M. guttatus benefited from heterosis, in terms of asexual and sexual reproduction, and biomass production, particularly when plants from native and invasive populations were crossed. This suggests that, when novel genotypes of M. guttatus from the native North American range will be introduced to the invasive ranges, subsequent outcrossing with M. guttatus plants that are already there might further boost invasiveness of this species. PMID:26354937

  13. Analysis of genetic admixture in Uyghur using the 26 Y-STR loci system.

    PubMed

    Bian, Yingnan; Zhang, Suhua; Zhou, Wei; Zhao, Qi; Siqintuya; Zhu, Ruxin; Wang, Zheng; Gao, Yuzhen; Hong, Jie; Lu, Daru; Li, Chengtao

    2016-01-01

    The Uyghur population has experienced extensive interaction with European and Eastern Asian populations historically. A set of high-resolution genetic markers could be useful to infer the genetic relationships between the Uyghur population and European and Asian populations. In this study we typed 100 unrelated Uyghur males living in southern Xinjiang at 26 Y-STR loci. Using the high-resolution 26 Y-STR loci system, we investigated genetic and phylogenetic relationship between the Uyghur population and 23 reference European or Asian populations. We found that the Uyghur population exhibited a genetic admixture of Eastern Asian and European populations, and had a slightly closer relationship with the selected European populations than the Eastern Asian populations. We also demonstrated that the 26 Y-STR loci system was potentially useful in forensic sciences because it has a large power of discrimination and rarely exhibits common haplotypes. However, ancestry inference of Uyghur samples could be challenging due to the admixed nature of the population. PMID:26842947

  14. Distribution of HLA haplotypes across Japanese Archipelago: similarity, difference and admixture.

    PubMed

    Nakaoka, Hirofumi; Inoue, Ituro

    2015-11-01

    The human leukocyte antigen (HLA) region is the most polymorphic region in the human genome. The polymorphic nature of the HLA region is thought to have been shaped from balancing selection. The complex migration events during the Out-of-Africa expansion have influenced geographic patterns of HLA allele frequencies and diversities across present-day human populations. Differences in the HLA allele frequency may contribute geographic differences in the susceptibility to many diseases, such as infectious, autoimmune and metabolic diseases. Here we briefly reviewed characteristics of frequency distribution of HLA alleles and haplotypes in Japanese population. A large part of HLA alleles and haplotypes that are common in Japanese are shared with neighboring Asian populations. The differentiations in HLA alleles and haplotypes across Japanese regional populations may provide clues to model for peopling of Japanese Archipelago and for design of genetic association studies. Finally, we introduce recent topics that new HLA alleles derived from ancient admixtures with Neanderthals and Denisovans are thought to have played an important role in the adaptation of modern humans to local pathogens during Out-of-Africa expansion. PMID:26202576

  15. Use of ready-mixed concrete plant sludge water in concrete containing an additive or admixture.

    PubMed

    Chatveera, B; Lertwattanaruk, P

    2009-04-01

    In this study, we investigated the feasibility of using sludge water from a ready-mixed concrete plant as mixing water in concrete containing either fly ash as an additive or a superplasticizer admixture based on sulfonated naphthalene-formaldehyde condensates (SNF). The chemical and physical properties of the sludge water and the dry sludge were investigated. Cement pastes were mixed using sludge water containing various levels of total solids content (0.5, 2.5, 5, 7.5, 10, 12.5, and 15%) in order to determine the optimum content in the sludge water. Increasing the total solids content beyond 5-6% tended to reduce the compressive strength and shorten the setting time. Concrete mixes were then prepared using sludge water containing 5-6% total solids content. The concrete samples were evaluated with regard to water required, setting time, slump, compressive strength, permeability, and resistance to acid attack. The use of sludge water in the concrete mix tended to reduce the effect of both fly ash and superplasticizer. Sludge water with a total solids content of less than 6% is suitable for use in the production of concrete with acceptable strength and durability. PMID:19231063

  16. Efficiency of the coherent biexciton admixture mechanism for multiple exciton generation in InAs nanocrystals

    NASA Astrophysics Data System (ADS)

    Kowalski, Piotr; Machnikowski, Paweł

    2015-12-01

    We study the coherent mixing between two-particle (single exciton) and four-particle (biexciton) states of a semiconductor nanocrystal resulting from the Coulomb coupling between states with different numbers of electron-hole pairs. Using a simple model of the nanocrystal wave functions and an envelope function approach, we estimate the efficiency of the multiple exciton generation (MEG) process resulting from such coherent admixture mechanism, including all the relevant states in a very broad energy interval. We show that in a typical ensemble of nanocrystals with an average radius of 3nm, the onset of the MEG process appears about 1 eV above the lower edge of the biexciton density of states. This is due to the angular momentum conservation that imposes selection rules and limits the available MEG pathways, thus taking over the role of momentum conservation that hinders this process in bulk. The efficiency of the MEG process reaches 50% for photon energies around 5 eV. The MEG onset shifts to lower energies and therefore the efficiency increases in a certain energy range as the radius grows. The energy dependence of the MEG efficiency differs considerably between ensembles with small and large inhomogeneity of nanocrystal sizes.

  17. Effects of drying conditions, admixtures and specimen size on shrinkage strains

    SciTech Connect

    Al-Saleh, Saleh A. . E-mail: alsaleh@dr.com; Al-Zaid, Rajeh Z.

    2006-10-15

    The paper presents the results of an experimental investigation on the effects of drying conditions, specimen size and presence of plasticizing admixture on the development of shrinkage strains. The measurements are taken in a harsh (50 deg. C and 5% R.H.) and a moderate environment (28 deg. C and 50% R.H.). The results include strain development at various levels of cross sections of concrete prisms. The drying conditions are found to be the dominant parameter affecting the shrinkage strain development particularly in specimens of smaller sizes. The effect of plasticizing admixture on shrinkage strains is negligible.

  18. Pilot study of the application of Tellus airborne radiometric and soil geochemical data for radon mapping.

    PubMed

    Appleton, J D; Miles, J C H; Green, B M R; Larmour, R

    2008-10-01

    The scope for using Tellus Project airborne gamma-ray spectrometer and soil geochemical data to predict the probability of houses in Northern Ireland having high indoor radon concentrations is evaluated, in a pilot study in the southeast of the province, by comparing these data statistically with in-house radon measurements. There is generally good agreement between radon maps modelled from the airborne radiometric and soil geochemical data using multivariate linear regression analysis and conventional radon maps which depend solely on geological and indoor radon data. The radon maps based on the Tellus Project data identify some additional areas where the radon risk appears to be relatively high compared with the conventional radon maps. One of the ways of validating radon maps modelled on the Tellus Project data will be to carry out additional indoor measurements in these areas. PMID:18562054

  19. A STUDY ON REASONS OF ERRORS OF OLD SURVEY MAPS IN CADASTRAL SYSTEM

    NASA Astrophysics Data System (ADS)

    Yanase, Norihiko

    This paper explicates sources on survey map errors which were made in 19th century. The present cadastral system stands on registers and survey maps which were compiled to change the land taxation system in the Meiji era. Many Japanese may recognize the reasons why poor survey technique by farmers, too long measure to avoid heavy tax, careless official check and other deception made such errors of acreage from several to more than ten percent of area in survey maps. The author would like to maintain that such errors, called nawa-nobi, were lawful in accordance with the then survey regulation because of results to analyze old survey regulations, history of making maps and studies of cadastral system. In addition to, a kind of survey maps' errors should be pointed out a reason why the easy subdivision system which could approve without real survey and disposal of state property with inadequate survey.

  20. Growth and characterisation of l-threonine, dl-threonine and l-methionine admixtured TGS crystals

    NASA Astrophysics Data System (ADS)

    Meera, K.; Muralidharan, R.; Tripathi, A. K.; Ramasamy, P.

    2004-03-01

    The amino acids l-threonine, dl-threonine and l-methionine admixtured triglycine sulfate crystals were grown from aqueous solution by solution growth technique. The cell parameter values were found using powder X-ray diffraction analysis. FTIR analysis was used to estimate qualitatively the presence of the amino acids in the grown crystal. The dielectric studies were carried out to identify the phase transition temperature and to find the dielectric constant. Pyroelectric studies were carried out on the (0 1 0) plate and the pyroelectric co-efficient was calculated. Piezoelectric studies were also carried out on the grown crystals. Microhardness studies were carried out using Leitz Weitzler hardness tester at room temperature.

  1. The Use of Study Maps and Visual Mnemotechnics as an Aid to Recall.

    ERIC Educational Resources Information Center

    Aaronson, Shirley

    1985-01-01

    Notes that many students lack the skills necessary for the efficient memorization of content information as well as awareness of appropriate rehearsal strategies or metacognitive skills. Discusses several rehearsal strategies, and concentrates on one--study mapping. (FL)

  2. History and future of the Multidisciplinary Association for Psychedelic Studies (MAPS).

    PubMed

    Emerson, Amy; Ponté, Linnae; Jerome, Lisa; Doblin, Rick

    2014-01-01

    This article describes the teenage vision of the founder of the Multidisciplinary Association for Psychedelic Studies (MAPS) that humanity's future would be aided by the therapeutic and spiritual potential of psychedelic substances. The article traces the trajectory of MAPS from inception in 1986 to its present, noting future goals with respect to research, outreach, and harm reduction. MAPS was created as a non-profit psychedelic pharmaceutical company in response to the 1985 scheduling of 3,4-methylenedioxymethamphetamine (MDMA). Overcoming many hurdles, MAPS developed the first double-blind, placebo-controlled trial of MDMA-assisted psychotherapy for posttraumatic stress disorder (PTSD) and plans for FDA prescription approval in 2021. MAPS' program of research expanded to include a trial of lysergic acid diethylamide (LSD)-assisted psychotherapy for anxiety when facing life-threatening illness, observational studies of ibogaine in the treatment of addiction, and studies of MDMA for social anxiety in people with autism spectrum disorders. MAPS meets the challenges of drug development through a clinical research team led by a former Novartis drug development professional experienced in the conduct, monitoring, and analysis of clinical trials. MAPS' harm-reduction efforts are intended to avoid backlash and build a post-prohibition world by assisting non-medical users to transform difficult psychedelic experiences into opportunities for growth. PMID:24830183

  3. Thinking Maps: An innovative way to increase sixth-grade student achievement in social studies

    NASA Astrophysics Data System (ADS)

    Reed, Tamita

    The purpose of this quantitative study was to determine the effect of Thinking Maps on the achievement of 6th-grade social studies students in order to determine its effectiveness. The population of this study came from a suburban middle school in the state of Georgia. The quantitative data included a pretest and posttest. The study was designed to find (a) whether there is a significant difference between the mean posttest scores on the benchmark test of 6th-grade students who are taught with either Thinking Maps or traditional social studies methods, (b) whether there is a significant difference between the mean posttest scores on the benchmark test of 6th-grade male versus female social studies students, and (c) whether there is a significant interaction between 6th-grade students' type of social studies class and gender as to differentially affect their mean posttest scores on the benchmark test. To answer these questions, students' pretest and posttest were compared to determine if there was a statistically significant difference after Thinking Maps were implemented with the treatment group for 9 weeks. The results indicate that there was no significant difference in the test scores between the students who were taught with Thinking Maps and the students who were taught without Thinking Maps. However, the students taught with Thinking Maps had the higher adjusted posttest scores.

  4. Selection of a taxonomic level for soil mapping using diversity and map purity indices: A case study from an Iranian arid region

    NASA Astrophysics Data System (ADS)

    Jafari, A.; Ayoubi, S.; Khademi, H.; Finke, P. A.; Toomanian, N.

    2013-11-01

    There is a growing demand for digital soil maps for environmental planning, modeling and management. If mapped soil classes are taken from a hierarchical taxonomic system, a question arises: which taxonomic level is most appropriate to be depicted on the map with a given sample size, available environmental covariates and the strength of predictive relations between covariates and the soil classes? Pedodiversity, the study and measurement of soil diversity, can be considered as a framework to analyze spatial patterns depicted on soil maps. This paper discusses the selection of the taxonomic level for soil mapping in an arid region in southeast Iran on the basis of (1) the purity of a digital soil class map derived from an artificial neural network (ANN) prediction method using environmental covariates and (2) pedodiversity indices of these soil maps. The prediction of soil classes and the calculation of diversity indices were carried out for taxonomic categories of order, suborder, great group, and subgroup. Using the feed forward back-propagation algorithm, three-layer ANNs with input, hidden and output layers were trained for soil class prediction at each category level. In most predictions, the combined use of terrain attributes and geomorphic surfaces provided the best results. When the taxonomic level changed from order to subgroup, the purity decreased, whereas the values of the diversity indices increased. The highest purity and lowest diversity are observed at the order level, indicating a good quality map in terms of its purity, but reflecting only little soil diversity, thus with a low usage potential. On the other hand, soil maps at the level of subgroup illustrate high diversity and low purity, so that the predicted map units are highly uncertain. This map is also inappropriate for users. We introduced an index combining the diversity and purity which indicated that the best taxonomic level for soil mapping in the study area is the great group, with

  5. Long-term development of the Czech landscape studied on the basis of old topographic maps

    NASA Astrophysics Data System (ADS)

    Skokanová, H.; Havlíček, M.

    2009-04-01

    The paper deals with long-term land use changes in the Czech Republic with the help of old topographic maps. Departments of Landscape Ecology and GIS Applications from the Silva Tarouca Research Institute for Landscape and Ornamental Gardening, v.v.i. study these changes mainly in the research project MSM 6293359101 Research into sources and indicators of biodiversity in cultural landscape in the context of its fragmentation dynamics, the subpart Quantitative analysis of the dynamics of the Czech landscape development. In this paper, the authors concentrate mainly on map sources, which were acquired for the purpose of the project and also introduce partial results. Maps, which are the sources for the analyses, are following: maps from 2nd Austrian military survey in the scale 1:28 800 (created for the territory of the Czech Republic in the period 1836-1852), maps from 3rd Austrian military survey in the scale 1:25 000 (created for the Czech Republic in the period 1876-1880), Czechoslovak military topographic maps in the scale 1:25 000 from 1950s and 1990s, and Czech topographic base maps in the scale 1:10 000 from 2002-2006. It is necessary to complete maps of the 2nd and 3rd Austrian military survey thanks to their incompleteness, mainly along state borders. Also maps from 1nd Austrian military survey in the scale 1:28 800 (created for the Czech Republic in the period 1764-1783) are available; however, their usage for the accurate analyses in the GIS environment is restricted by their poor cartographic accuracy. Apart of the above mentioned maps, there has been progress in collecting maps from the interwar and war period (revised maps of the 3rd Austrian military survey maps, maps of the provisional military survey from 1923-1933, maps of definitive military survey from 1934-1938 and maps from survey of Moravian part of the Protectorate of Bohemia and Moravia, so called Messtischblätter from 1939-1945). Maps from five periods are manually vectorised in the GIS

  6. 78 FR 71707 - MAP-21 Comprehensive Truck Size and Weight Limits Study Public Meeting and Outreach Sessions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-11-29

    ... Federal Highway Administration MAP-21 Comprehensive Truck Size and Weight Limits Study Public Meeting and... Century Act (MAP-21) Comprehensive Truck Size and Weight Limits Study. The Transportation Research Board... MAP-21 Comprehensive Truck Size and Weight Limits Study. The DOT will hold a second public...

  7. A Study of Biomedical Concept Identification: MetaMap vs. People

    PubMed Central

    Pratt, Wanda; Yetisgen-Yildiz, Meliha

    2003-01-01

    Although huge amounts of unstructured text are available as a rich source of biomedical knowledge, to process this unstructured knowledge requires tools that identify concepts from free-form text. MetaMap is one tool that system developers in biomedicine have commonly used for such a task, but few have studied how well it accomplishes this task in general. In this paper, we report on a study that compares MetaMap’s performance against that of six people. Such studies are challenging because the task is inherently subjective and establishing consensus is difficult. Nonetheless, for those concepts that subjects generally agreed on, MetaMap was able to identify most concepts, if they were represented in the UMLS. However, MetaMap identified many other concepts that people did not. We also report on our analysis of the types of failures that MetaMap exhibited as well as trends in the way people chose to identify concepts. PMID:14728229

  8. Cognitive distortions based on MDS configuration and sketch mapping: a case study in Beijing

    NASA Astrophysics Data System (ADS)

    Shen, Si; Xue, Lulu; Wu, Lun; Liu, Yu

    2007-06-01

    As an emerging field, cognitive map kept playing a significant role in geography these decades. To date, there are two dominant methods to externalize human's internal cognitive map, namely, multidimensional scaling (MDS) and skech mapping. However, among most recent researches on cognitive map, the differences between both methods are always ignored. The usage of one method over another is still under scrutiny. In order to shed light on the similarity or distinctions of MDS configuration and sketch mapping, we conducted an experiment on Beijing residents by requesting a sketch of the region within 3rd Ring and meanwhile extracting distance estimates between 8 landmarks. Employing the Bidimensional regression along with standard deviational ellipse, we studied the global and local distortions among two kinds of cognitive maps and quantitatively measure the overall and local cognitive maps distortions. Besides, we use Monte Carlo simulation method to calculate the radius of distortion for the Distortion Index (DI). It shows that the average cognitive distortion of habitants in Beijing is 2km to 3km, and the distortion takes 2nd-ring road as a border, displaying a southwest-northeast diagonal stretch and an east-west contracted tendency. The distortion in the two methods is remarkably both correlated with factors, such as travel frequency and years of residence. Comparing two methods, it turned out that sketch map was more consistent with real map, while the distortion orientations of sketch map resembled MDS configuration. Finally, we gave possible reasons with regard to above conclusions and advices for future usage of two methods.

  9. WWC Quick Review of "Retrieval Practice Produces More Learning than Elaborative Studying with Concept Mapping"

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2011

    2011-01-01

    The study examined whether using the retrieval-practice studying technique--in which students alternate between reading a passage and writing memorable information from that passage--improved student learning of a science passage more than the study-once, repeated-study, or concept-mapping techniques. The study found that students using the…

  10. Inverse field-based approach for simultaneous B₁ mapping at high fields - a phantom based study.

    PubMed

    Jin, Jin; Liu, Feng; Zuo, Zhentao; Xue, Rong; Li, Mingyan; Li, Yu; Weber, Ewald; Crozier, Stuart

    2012-04-01

    Based on computational electromagnetics and multi-level optimization, an inverse approach of attaining accurate mapping of both transmit and receive sensitivity of radiofrequency coils is presented. This paper extends our previous study of inverse methods of receptivity mapping at low fields, to allow accurate mapping of RF magnetic fields (B(1)) for high-field applications. Accurate receive sensitivity mapping is essential to image domain parallel imaging methods, such as sensitivity encoding (SENSE), to reconstruct high quality images. Accurate transmit sensitivity mapping will facilitate RF-shimming and parallel transmission techniques that directly address the RF inhomogeneity issue, arguably the most challenging issue of high-field magnetic resonance imaging (MRI). The inverse field-based approach proposed herein is based on computational electromagnetics and iterative optimization. It fits an experimental image to the numerically calculated signal intensity by iteratively optimizing the coil-subject geometry to better resemble the experiments. Accurate transmit and receive sensitivities are derived as intermediate results of the optimization process. The method is validated by imaging studies using homogeneous saline phantom at 7T. A simulation study at 300MHz demonstrates that the proposed method is able to obtain receptivity mapping with errors an order of magnitude less than that of the conventional method. The more accurate receptivity mapping and simultaneously obtained transmit sensitivity mapping could enable artefact-reduced and intensity-corrected image reconstructions. It is hoped that by providing an approach to the accurate mapping of both transmit and receive sensitivity, the proposed method will facilitate a range of applications in high-field MRI and parallel imaging. PMID:22391489

  11. Effects of birthplace and individual genetic admixture on lung volume and exercise phenotypes of Peruvian Quechua.

    PubMed

    Brutsaert, Tom D; Parra, Esteban; Shriver, Mark; Gamboa, Alfredo; Palacios, Jose-Antonio; Rivera, Maria; Rodriguez, Ivette; León-Velarde, Fabiola

    2004-04-01

    Forced vital capacity (FVC) and maximal exercise response were measured in two populations of Peruvian males (age, 18-35 years) at 4,338 m who differed by the environment in which they were born and raised, i.e., high altitude (Cerro de Pasco, Peru, BHA, n = 39) and sea level (Lima, Peru, BSL, n = 32). BSL subjects were transported from sea level to 4,338 m, and were evaluated within 24 hr of exposure to hypobaric hypoxia. Individual admixture level (ADMIX, % Spanish ancestry) was estimated for each subject, using 22 ancestry-informative genetic markers and also by skin reflectance measurement (MEL). Birthplace accounted for the approximately 10% larger FVC (P < 0.001), approximately 15% higher maximal oxygen consumption (VO(2)max, ml.min(-1).kg(-1)) (P < 0.001), and approximately 5% higher arterial oxygen saturation during exercise (SpO(2)) (P < 0.001) of BHA subjects. ADMIX was low in both study groups, averaging 9.5 +/- 2.6% and 2.1 +/- 0.3% in BSL and BHA subjects, respectively. Mean underarm MEL was significantly higher in the BSL group (P < 0.001), despite higher ADMIX. ADMIX was not associated with any study phenotype, but study power was not sufficient to evaluate hypotheses of genetic adaptation via the ADMIX variable. MEL and FVC were positively correlated in the BHA (P = 0.035) but not BSL (P = 0.335) subjects. However, MEL and ADMIX were not correlated across the entire study sample (P = 0.282). In summary, results from this study emphasize the importance of developmental adaptation to high altitude. While the MEL-FVC correlation may reflect genetic adaptation to high altitude, study results suggest that alternate (environmental) explanations be considered. PMID:15022366

  12. Mapping Disease at an Approximated Individual Level Using Aggregate Data: A Case Study of Mapping New Hampshire Birth Defects

    PubMed Central

    Shi, Xun; Miller, Stephanie; Mwenda, Kevin; Onda, Akikazu; Rees, Judy; Onega, Tracy; Gui, Jiang; Karagas, Margaret; Demidenko, Eugene; Moeschler, John

    2013-01-01

    Background: Limited by data availability, most disease maps in the literature are for relatively large and subjectively-defined areal units, which are subject to problems associated with polygon maps. High resolution maps based on objective spatial units are needed to more precisely detect associations between disease and environmental factors. Method: We propose to use a Restricted and Controlled Monte Carlo (RCMC) process to disaggregate polygon-level location data to achieve mapping aggregate data at an approximated individual level. RCMC assigns a random point location to a polygon-level location, in which the randomization is restricted by the polygon and controlled by the background (e.g., population at risk). RCMC allows analytical processes designed for individual data to be applied, and generates high-resolution raster maps. Results: We applied RCMC to the town-level birth defect data for New Hampshire and generated raster maps at the resolution of 100 m. Besides the map of significance of birth defect risk represented by p-value, the output also includes a map of spatial uncertainty and a map of hot spots. Conclusions: RCMC is an effective method to disaggregate aggregate data. An RCMC-based disease mapping maximizes the use of available spatial information, and explicitly estimates the spatial uncertainty resulting from aggregation. PMID:24018838

  13. Dynamic processes and their influence on the transformation of the passive admixture in the sea of Azov

    NASA Astrophysics Data System (ADS)

    Ivanov, V. A.; Cherkesov, L. V.; Shul'ga, T. Ya.

    2014-07-01

    In this model, we apply a nonlinear three-dimensional sigma-coordinate model to study the waves and currents in the Sea of Azov generated by different fields of wind forcing: a constant wind, a quickly varying real wind obtained using the data of reanalysis applying the SKIRON model, and the wind resulting from their combined forcing. This mathematical model was also applied to study the transformation of the passive admixture appearing under the influence of wind fields in the Sea of Azov considered here. We compared the results of numerical calculations with the field data obtained under the wind forcing at a number of hydrological stations. We found the regularities of the water transport driven by onshore and offshore winds, the velocities of the currents, and the characteristics of the evolution of polluted regions at different depths as functions of the nonstationary wind intensity and the velocities of the stationary currents.

  14. Admixture of propofol and alfentanil. Use for intravenous sedation and analgesia during transvaginal oocyte retrieval.

    PubMed

    Sherry, E

    1992-06-01

    An admixture of propofol and alfentanil provides adequate sedation and analgesia during transvaginal oocyte retrieval in the absence of a paracervical block. In 100 patients the technique provided haemodynamic stability, sedation which was easily controlled, rapid recovery and universal patient acceptance. PMID:1616081

  15. What Causes Birth Order-Intelligence Patterns? The Admixture Hypothesis, Revived.

    ERIC Educational Resources Information Center

    Rodgers, Joseph Lee

    2001-01-01

    Describes why birth order interests both parents and researchers, discussing what really causes apparent birth order effects on intelligence, examining problems with using cross-sectional intelligence data, and noting how to move beyond cross-sectional inferences. Explains the admixture hypothesis, which finds that family size is much more…

  16. Chemical Stability of Admixtures Combining Ziconotide with Morphine or Hydromorphone During Simul ated Intrathecal Administration.

    PubMed

    Shields, David; Montenegro, Rick; Ragusa, Matthew

    2005-10-01

    Objective.  To determine the stability of admixtures combining ziconotide with morphine or hydromorphone under simulated intrathecal infusions. Materials and Methods.  Admixtures of ziconotide (25 µg/mL) with morphine or hydromorphone (both at 35 mg/mL) were stored in Medtronic SynchroMed® II pumps at 37°C, and in control vials at 37°C and 5°C. Drug concentrations were determined using high-performance liquid chromatography. Results.  The ziconotide pump concentration with morphine declined to 79% of initial in 17 days, and to 88% of initial after 25 days with hydromorphone. Ziconotide concentrations in control vials stored at 37°C displayed similar rates of decay, but vials stored at 5°C exhibited no ziconotide loss. A statistical evaluation of the two combinations shows ziconotide-hydromorphone retaining 80% stability for 40 days (extrapolated), compared to 15 days for ziconotide-morphine. Morphine and hydromorphone were stable in the presence of ziconotide under all conditions. Conclusions.  Ziconotide-hydromorphone admixtures were more stable than ziconotide-morphine admixtures. PMID:22151554

  17. Phenomenological model of sintering of oxide nuclear fuel with doping admixtures

    SciTech Connect

    Baranov, V. G.; Devyatko, Yu. N.; Tenishev, A. V.; Khomyakov, O. V.

    2015-12-15

    It is shown that a change in the linear dimension of compacted UO{sub 2} in the sintering process is associated with its plastic yielding under the action of the forces of residual stress and capillary forces. From the curves of sintering of a fuel with doping admixtures in various gaseous media, its rate of creep is reduced.

  18. Zinc content of commercial diluents widely used in drug admixtures prepared for intravenous infusion.

    PubMed

    Desai, Narendra R; Shah, Syed M; Koczone, Julianna; Vencl-Joncic, Maja; Sisto, Christopher; Ludwig, Stephen A

    2007-01-01

    During ongoing quality improvement efforts with two Wyeth parenteral products, Protonix and Zosyn, we noted that dosing solutions prepared from the products yielded inconsistent results on the United States Pharmacopeia Chapter 788 test for subvisible particulates. This manuscript discusses variables that have a direct impact on intravenous products meeting compendial monograph specifications under conditions that are encountered in the clinical setting. The rubber stoppers of vials used for parenteral products, different parts of commercial admixture bags, and the tubing of the administration sets and devices contain residual amounts of metal ions, plasticizers, and other additives incorparated for specific functions. The transition metal ions, including zinc and copper, may leach into drug products during manufacture and during storage of dosing admixture bags prepared for infusion in hospital pharmacies or clinics. The metal ions may compromise the quality of the infusion admixture through catalytic drug degradation and/or generation of undesirable metal ion complexes, which may convert soluble drug molecules into insoluble particulates. To preserve the quality of the drug product, it is essential that metal ion leachables be controlled proactively during manufacture of the drug product; knowledge of metal ion contents in the commercial diluents use for reconstitution, admixture preparation, and flushing of the administration lines is also critical. PMID:23969523

  19. Characterizing semantic mappings adaptation via biomedical KOS evolution: a case study investigating SNOMED CT and ICD.

    PubMed

    Dos Reis, Julio Cesar; Pruski, Cédric; Da Silveira, Marcos; Reynaud-Delaître, Chantal

    2013-01-01

    Mappings established between Knowledge Organization Systems (KOS) increase semantic interoperability between biomedical information systems. However, biomedical knowledge is highly dynamic and changes affecting KOS entities can potentially invalidate part or the totality of existing mappings. Understanding how mappings evolve and what the impacts of KOS evolution on mappings are is therefore crucial for the definition of an automatic approach to maintain mappings valid and up-to-date over time. In this article, we study variations of a specific KOS complex change (split) for two biomedical KOS (SNOMED CT and ICD-9-CM) through a rigorous method of investigation for identifying and refining complex changes, and for selecting representative cases. We empirically analyze and explain their influence on the evolution of associated mappings. Results point out the importance of considering various dimensions of the information described in KOS, like the semantic structure of concepts, the set of relevant information used to define the mappings and the change operations interfering with this set of information. PMID:24551341

  20. The Case Study as Research Heuristic: Lessons from the R&D Value Mapping Project.

    ERIC Educational Resources Information Center

    Bozeman, Barry; Klein, Hans K.

    1999-01-01

    Examines the role of prototype case studies as the foundation for later evaluation through two studies from the "R&D Value Mapping Project," a study that will involve more than 30 cases. Explores the usefulness of case studies in defining and assessing subsequent research efforts. (SLD)

  1. Study Abroad and the City: Mapping Urban Identity

    ERIC Educational Resources Information Center

    Blair, Scott

    2011-01-01

    Study abroad by U.S. students, despite recent growth into non-western and rural destinations, often remains focused on cities, often very large and highly urbanized ones. While the destination cities for study abroad are located across the globe, European cities remain predominant, and thus, this article focuses on study abroad in one city. The…

  2. Research on Integrated Mapping——A Case Study of Integrated Land Use with Swamp Mapping

    NASA Astrophysics Data System (ADS)

    Zhang, S.; Yan, F.; Chang, L.

    2015-12-01

    Unified real estate registration system shows the attention, determination and effort to of CPC Central Committee and State Council on real estate registration in China. However, under current situation, China's real estate registration work made less progress. One of the reasons is that it's hard to express the property right of real estate on one map under the multi-sector management system. Under current multi-sector management system in China, different departments usually just survey and mapping the land type under its jurisdiction. For example, wetland investigation only mapping all kinds of wetland resources but not mapping other resource types. As a result, it cause he problem of coincidence or leak in integration of different results from different departments. As resources of the earth's surface, the total area of forest, grassland, wetland and so on should be equal to the total area of the earth's surface area. However, under the current system, the area of all kinds of resources is not equal to the sum of the earth's surface. Therefore, it is of great importance to express all the resources on one map. On one hand, this is conducive to find out the real area and distribution of resources and avoid the problem of coincidence or leak in integration; On the other hand, it is helpful to study the dynamic change of different resources. Therefore, we first proposed the "integrated mapping" as a solution, and take integrated land use with swamp mapping in Northeast China as an example to investigate the feasibility and difficulty. Study showed that: integrated land use with swamp mapping can be achieved through combining land use survey standards with swamps survey standards and "second mapping" program. Based on the experience of integrated land use with swamp mapping, we point out its reference function on integrated mapping and unified real estate registration system. We concluded that: (1) Comprehending and integrating different survey standard of

  3. Genetic analysis of ancestry, admixture and selection in Bolivian and Totonac populations of the New World

    PubMed Central

    2012-01-01

    Background Populations of the Americas were founded by early migrants from Asia, and some have experienced recent genetic admixture. To better characterize the native and non-native ancestry components in populations from the Americas, we analyzed 815,377 autosomal SNPs, mitochondrial hypervariable segments I and II, and 36 Y-chromosome STRs from 24 Mesoamerican Totonacs and 23 South American Bolivians. Results and Conclusions We analyzed common genomic regions from native Bolivian and Totonac populations to identify 324 highly predictive Native American ancestry informative markers (AIMs). As few as 40–50 of these AIMs perform nearly as well as large panels of random genome-wide SNPs for predicting and estimating Native American ancestry and admixture levels. These AIMs have greater New World vs. Old World specificity than previous AIMs sets. We identify highly-divergent New World SNPs that coincide with high-frequency haplotypes found at similar frequencies in all populations examined, including the HGDP Pima, Maya, Colombian, Karitiana, and Surui American populations. Some of these regions are potential candidates for positive selection. European admixture in the Bolivian sample is approximately 12%, though individual estimates range from 0–48%. We estimate that the admixture occurred ~360–384 years ago. Little evidence of European or African admixture was found in Totonac individuals. Bolivians with pre-Columbian mtDNA and Y-chromosome haplogroups had 5–30% autosomal European ancestry, demonstrating the limitations of Y-chromosome and mtDNA haplogroups and the need for autosomal ancestry informative markers for assessing ancestry in admixed populations. PMID:22606979

  4. Toward Mapping a Feminist Cultural Studies Approach to Composition.

    ERIC Educational Resources Information Center

    Langstraat, Lisa R.

    At this time when feminist criticism is working its way into the field of composition and cultural studies, three issues call for discussion. First of all, composition because it is a "feminized" field as it has historically been defined as "women's work," it is a radically different terrain from cultural studies. A close scrutiny of institutional…

  5. Mapping biomass with remote sensing: a comparison of methods for the case study of Uganda

    PubMed Central

    2011-01-01

    Background Assessing biomass is gaining increasing interest mainly for bioenergy, climate change research and mitigation activities, such as reducing emissions from deforestation and forest degradation and the role of conservation, sustainable management of forests and enhancement of forest carbon stocks in developing countries (REDD+). In response to these needs, a number of biomass/carbon maps have been recently produced using different approaches but the lack of comparable reference data limits their proper validation. The objectives of this study are to compare the available maps for Uganda and to understand the sources of variability in the estimation. Uganda was chosen as a case-study because it presents a reliable national biomass reference dataset. Results The comparison of the biomass/carbon maps show strong disagreement between the products, with estimates of total aboveground biomass of Uganda ranging from 343 to 2201 Tg and different spatial distribution patterns. Compared to the reference map based on country-specific field data and a national Land Cover (LC) dataset (estimating 468 Tg), maps based on biome-average biomass values, such as the Intergovernmental Panel on Climate Change (IPCC) default values, and global LC datasets tend to strongly overestimate biomass availability of Uganda (ranging from 578 to 2201 Tg), while maps based on satellite data and regression models provide conservative estimates (ranging from 343 to 443 Tg). The comparison of the maps predictions with field data, upscaled to map resolution using LC data, is in accordance with the above findings. This study also demonstrates that the biomass estimates are primarily driven by the biomass reference data while the type of spatial maps used for their stratification has a smaller, but not negligible, impact. The differences in format, resolution and biomass definition used by the maps, as well as the fact that some datasets are not independent from the reference data to which they

  6. On the feasibility of tracking with differential-algebra maps in long-term stability studies for large hadron colliders

    SciTech Connect

    Kleiss, R.; Schmidt, F.; Yan, Y.

    1992-01-01

    A time-saving alternative to conventional element-by-element tracking in long-term stability studies is the use of truncated Taylor maps. This report discusses how the non-symplecticity of a moderately high-order truncated Taylor map affects its reliability when the map is used for tracking over several thousand turns. Various machines and two different map-constructing programs are compared. It is found that the discrepancies between the Taylor map results and those obtained by direct tracking grow with amplitude. Thus, such maps are not guaranteed to be sufficient for long-term tracking over millions of turns without suitable symplectification.

  7. Sub-pixel mapping of water boundaries using pixel swapping algorithm (case study: Tagliamento River, Italy)

    NASA Astrophysics Data System (ADS)

    Niroumand-Jadidi, Milad; Vitti, Alfonso

    2015-10-01

    Taking the advantages of remotely sensed data for mapping and monitoring of water boundaries is of particular importance in many different management and conservation activities. Imagery data are classified using automatic techniques to produce maps entering the water bodies' analysis chain in several and different points. Very commonly, medium or coarse spatial resolution imagery is used in studies of large water bodies. Data of this kind is affected by the presence of mixed pixels leading to very outstanding problems, in particular when dealing with boundary pixels. A considerable amount of uncertainty inescapably occurs when conventional hard classifiers (e.g., maximum likelihood) are applied on mixed pixels. In this study, Linear Spectral Mixture Model (LSMM) is used to estimate the proportion of water in boundary pixels. Firstly by applying an unsupervised clustering, the water body is identified approximately and a buffer area considered ensuring the selection of entire boundary pixels. Then LSMM is applied on this buffer region to estimate the fractional maps. However, resultant output of LSMM does not provide a sub-pixel map corresponding to water abundances. To tackle with this problem, Pixel Swapping (PS) algorithm is used to allocate sub-pixels within mixed pixels in such a way to maximize the spatial proximity of sub-pixels and pixels in the neighborhood. The water area of two segments of Tagliamento River (Italy) are mapped in sub-pixel resolution (10m) using a 30m Landsat image. To evaluate the proficiency of the proposed approach for sub-pixel boundary mapping, the image is also classified using a conventional hard classifier. A high resolution image of the same area is also classified and used as a reference for accuracy assessment. According to the results, sub-pixel map shows in average about 8 percent higher overall accuracy than hard classification and fits very well in the boundaries with the reference map.

  8. Genome-wide patterns of population structure and admixture in West Africans and African Americans.

    PubMed

    Bryc, Katarzyna; Auton, Adam; Nelson, Matthew R; Oksenberg, Jorge R; Hauser, Stephen L; Williams, Scott; Froment, Alain; Bodo, Jean-Marie; Wambebe, Charles; Tishkoff, Sarah A; Bustamante, Carlos D

    2010-01-12

    Quantifying patterns of population structure in Africans and African Americans illuminates the history of human populations and is critical for undertaking medical genomic studies on a global scale. To obtain a fine-scale genome-wide perspective of ancestry, we analyze Affymetrix GeneChip 500K genotype data from African Americans (n = 365) and individuals with ancestry from West Africa (n = 203 from 12 populations) and Europe (n = 400 from 42 countries). We find that population structure within the West African sample reflects primarily language and secondarily geographical distance, echoing the Bantu expansion. Among African Americans, analysis of genomic admixture by a principal component-based approach indicates that the median proportion of European ancestry is 18.5% (25th-75th percentiles: 11.6-27.7%), with very large variation among individuals. In the African-American sample as a whole, few autosomal regions showed exceptionally high or low mean African ancestry, but the X chromosome showed elevated levels of African ancestry, consistent with a sex-biased pattern of gene flow with an excess of European male and African female ancestry. We also find that genomic profiles of individual African Americans afford personalized ancestry reconstructions differentiating ancient vs. recent European and African ancestry. Finally, patterns of genetic similarity among inferred African segments of African-American genomes and genomes of contemporary African populations included in this study suggest African ancestry is most similar to non-Bantu Niger-Kordofanian-speaking populations, consistent with historical documents of the African Diaspora and trans-Atlantic slave trade. PMID:20080753

  9. BRAF and MAP2K1 mutations in Langerhans cell histiocytosis: a study of 50 cases.

    PubMed

    Alayed, Khaled; Medeiros, L Jeffrey; Patel, Keyur P; Zuo, Zhuang; Li, Shaoying; Verma, Shalini; Galbincea, John; Cason, R Craig; Luthra, Rajyalakshmi; Yin, C Cameron

    2016-06-01

    Langerhans cell histiocytosis (LCH) is a proliferation of Langerhans cells, often associated with lymphocytes, eosinophils, macrophages, and giant cells. BRAF mutations, usually V600E, have been reported in 40%-70% of cases, and recently, MAP2K1 mutations have been reported in BRAF-negative cases. We assessed 50 cases of LCH for BRAF mutations and assessed a subset of cases for MAP2K1 mutations. The study group included 28 men and 22 women (median age, 36.5 years; range, 1-78 years). BRAF V600E mutation was detected in 8 (16%) cases including 3 (30%) skin, 2 (11%) bone, 1 (50%) colon, 1 (20%) lung, and 1 (33%) extradural, intracranial mass. MAP2K1 mutations were detected in 6 of 13 (46%) BRAF-negative cases including 2 (100%) lymph node, 2 (50%) bone, 1 (25%) skin, and 1 (100%) orbit. Patients with BRAF mutation were younger than patients with wild-type BRAF (median age, 28 versus 38 years; P = .026). The median age of MAP2K1-mutated patients was 34.5 years, similar to patients without MAP2K1 mutation (41 years; P = .368). In agreement with 2 recent studies, we showed a high frequency of MAP2K1 mutations in BRAF-negative LCH cases. Unlike other studies, the overall frequency of BRAF mutation in this cohort is substantially lower than what has been reported in pediatric patients, perhaps because most patients in this study were adults. Moreover, we showed a high concordance between mutational and immunohistochemical analysis for BRAF mutation. There was no statistically significant association between BRAF or MAP2K1 mutation and anatomic site, unifocal versus multifocal presentation, or clinical outcome. PMID:26980021

  10. Muscle and fat mapping of the trunk: a case study.

    PubMed

    Buckner, Samuel L; Abe, Takashi; Counts, Brittany R; Dankel, Scott J; Barnett, Brian E; Loenneke, Jeremy P

    2015-12-01

    The following case study examines the muscle and fat thickness of the trunk in a 25-year-old, former collegiate gymnast. Previous studies have quantified total and regional skeletal muscle mass using magnetic resonance imaging and muscle volume and distribution using ultrasound. However, to the best of our knowledge, the distribution and symmetry of skeletal muscle and subcutaneous adipose tissue (AT) of the anterior and posterior trunk have never been investigated. Ultrasound was used to identify skeletal muscle and AT thickness of 143 data points on the anterior portion of the trunk and 140 data points on the posterior portion of the trunk. Muscle thickness values in the anterior trunk ranged from 0.5 to 5.6 cm, and muscle thickness of the posterior trunk ranged from 0.6 to 6.6 cm. Total muscle volume of the trunk was 2935 and 4195 cm(3) for the anterior and posterior portions, respectively. The total predicted muscle mass in the anterior and posterior trunk was 7.4 kg. This case study begins to provide a picture of the distribution and symmetry of skeletal muscle and AT of the trunk. Future studies are necessary to confirm these findings and examine relationships among different populations. PMID:26550077

  11. Mapping More than Aboriginal Studies: Pedagogy, Professional Practice and Knowledge

    ERIC Educational Resources Information Center

    Norman, Heidi

    2014-01-01

    As undergraduate curriculum is increasingly required to meet a range of intellectual, professional practice and personal learning outcomes, what purpose does Australian Aboriginal Studies have in curriculum? Most Australian universities are currently in the process of developing institution-wide approaches to Indigenous Australian content in…

  12. Engineering Feasibility and Trade Studies for the NASA/VSGC MicroMaps Space Mission

    NASA Technical Reports Server (NTRS)

    Abdelkhalik, Ossama O.; Nairouz, Bassem; Weaver, Timothy; Newman, Brett

    2003-01-01

    Knowledge of airborne CO concentrations is critical for accurate scientific prediction of global scale atmospheric behavior. MicroMaps is an existing NASA owned gas filter radiometer instrument designed for space-based measurement of atmospheric CO vertical profiles. Due to programmatic changes, the instrument does not have access to the space environment and is in storage. MicroMaps hardware has significant potential for filling a critical scientific need, thus motivating concept studies for new and innovative scientific spaceflight missions that would leverage the MicroMaps heritage and investment, and contribute to new CO distribution data. This report describes engineering feasibility and trade studies for the NASA/VSGC MicroMaps Space Mission. Conceptual studies encompass: 1) overall mission analysis and synthesis methodology, 2) major subsystem studies and detailed requirements development for an orbital platform option consisting of a small, single purpose spacecraft, 3) assessment of orbital platform option consisting of the International Space Station, and 4) survey of potential launch opportunities for gaining assess to orbit. Investigations are of a preliminary first-order nature. Results and recommendations from these activities are envisioned to support future MicroMaps Mission design decisions regarding program down select options leading to more advanced and mature phases.

  13. Spatial memory extinction: a c-Fos protein mapping study.

    PubMed

    Méndez-Couz, M; Conejo, N M; Vallejo, G; Arias, J L

    2014-03-01

    While the neuronal basis of spatial memory consolidation has been thoroughly studied, the substrates mediating the process of extinction remain largely unknown. This study aimed to evaluate the functional contribution of selected brain regions during the extinction of a previously acquired spatial memory task in the Morris water maze. For that purpose, we used adult male Wistar rats trained in a spatial reference memory task. Learning-related changes in c-Fos inmunoreactive cells after training were evaluated in cortical and subcortical regions. Results show that removal of the hidden platform in the water maze induced extinction of the previously reinforced escape behavior after 16 trials, without spontaneous recovery 24h later. Extinction was related with significantly higher numbers of c-Fos positive nuclei in amygdala nuclei and prefrontal cortex. On the other hand, the lateral mammillary bodies showed higher number of c-Fos positive cells than the control group. Therefore, in contrast with the results obtained in studies of classical conditioning, we show the involvement of diencephalic structures mediating this kind of learning. In summary, our findings suggest that medial prefrontal cortex, the amygdala complex and diencephalic structures like the lateral mammillary nuclei are relevant for the extinction of spatial memory. PMID:24315832

  14. Meeting the Demands of Professional Education: A Study of Mind Mapping in a Professional Doctoral Physical Therapy Education Program

    ERIC Educational Resources Information Center

    Pollard, Elicia L.

    2010-01-01

    The purposes of this study are to investigate whether the quiz scores of physical therapy students who integrated mind mapping in their learning strategies are significantly different than the quiz scores of students who did not use mind mapping to learn in a lecture-based research course and examine the students' perceptions of mind mapping as a…

  15. Phylogeographic Analyses of American Black Bears (Ursus americanus) Suggest Four Glacial Refugia and Complex Patterns of Postglacial Admixture.

    PubMed

    Puckett, Emily E; Etter, Paul D; Johnson, Eric A; Eggert, Lori S

    2015-09-01

    Studies of species with continental distributions continue to identify intraspecific lineages despite continuous habitat. Lineages may form due to isolation by distance, adaptation, divergence across barriers, or genetic drift following range expansion. We investigated lineage diversification and admixture within American black bears (Ursus americanus) across their range using 22 k single nucleotide polymorphisms and mitochondrial DNA sequences. We identified three subcontinental nuclear clusters which we further divided into nine geographic regions: Alaskan (Alaska-East), eastern (Central Interior Highlands, Great Lakes, Northeast, Southeast), and western (Alaska-West, West, Pacific Coast, Southwest). We estimated that the western cluster diverged 67 ka, before eastern and Alaskan divergence 31 ka; these divergence dates contrasted with those from the mitochondrial genome where clades A and B diverged 1.07 Ma, and clades A-east and A-west diverged 169 ka. We combined estimates of divergence timing with hindcast species distribution models to infer glacial refugia for the species in Beringia, Pacific Northwest, Southwest, and Southeast. Our results show a complex arrangement of admixture due to expansion out of multiple refugia. The delineation of the genomic population clusters was inconsistent with the ranges for 16 previously described subspecies. Ranges for U. a. pugnax and U. a. cinnamomum were concordant with admixed clusters, calling into question how to order taxa below the species level. Additionally, our finding that U. a. floridanus has not diverged from U. a. americanus also suggests that morphology and genetics should be reanalyzed to assess taxonomic designations relevant to the conservation management of the species. PMID:25989983

  16. Wild Trypanosoma cruzi I genetic diversity in Brazil suggests admixture and disturbance in parasite populations from the Atlantic Forest region

    PubMed Central

    2014-01-01

    Background Trypanosoma cruzi (Kinetoplastida, Trypanosomatidae) infection is an ancient and widespread zoonosis distributed throughout the Americas. Ecologically, Brazil comprises several distinct biomes: Amazonia, Cerrado, Caatinga, Pantanal and the Atlantic Forest. Sylvatic T. cruzi transmission is known to occur throughout these biomes, with multiple hosts and vectors involved. Parasite species-level genetic diversity can be a useful marker for ecosystem health. Our aims were to: investigate sylvatic T. cruzi genetic diversity across different biomes, detect instances of genetic exchange, and explore the possible impact of ecological disturbance on parasite diversity at an intra-species level. Methods We characterised 107 isolates of T. cruzi I (TcI; discrete typing unit, DTU I) from different major Brazilian biomes with twenty-seven nuclear microsatellite loci. A representative subset of biologically cloned isolates was further characterised using ten mitochondrial gene loci. We compared these data generated from Brazilian TcI isolates from around America. Results Genetic diversity was remarkably high, including one divergent cluster that branched outside the known genetic diversity of TcI in the Americas. We detected evidence for mitochondrial introgression and genetic exchange between the eastern Amazon and Caatinga. Finally, we found strong signatures of admixture among isolates from the Atlantic Forest region by comparison to parasites from other study sites. Conclusions Atlantic Forest sylvatic TcI populations are highly fragmented and admixed by comparison to others around Brazil. We speculate on: the possible causes of Atlantic Forest admixture; the role of T. cruzi as a sentinel for ecosystem health, and the impact disrupted sylvatic transmission cycles might have on accurate source attribution in oral outbreaks. PMID:24903849

  17. Genome-wide analysis reveals the ancient and recent admixture history of East African Shorthorn Zebu from Western Kenya.

    PubMed

    Mbole-Kariuki, M N; Sonstegard, T; Orth, A; Thumbi, S M; Bronsvoort, B M de C; Kiara, H; Toye, P; Conradie, I; Jennings, A; Coetzer, K; Woolhouse, M E J; Hanotte, O; Tapio, M

    2014-10-01

    The Kenyan East African zebu cattle are valuable and widely used genetic resources. Previous studies using microsatellite loci revealed the complex history of these populations with the presence of taurine and zebu genetic backgrounds. Here, we estimate at genome-wide level the genetic composition and population structure of the East African Shorthorn Zebu (EASZ) of western Kenya. A total of 548 EASZ from 20 sub-locations were genotyped using the Illumina BovineSNP50 v. 1 beadchip. STRUCTURE analysis reveals admixture with Asian zebu, African and European taurine cattle. The EASZ were separated into three categories: substantial (⩾12.5%), moderate (1.56%admixture in the EASZ population, subsequently shaped by selection and/or genetic drift, followed by a more recent exotic European cattle introgression. PMID:24736786

  18. Genome-wide analysis reveals the ancient and recent admixture history of East African Shorthorn Zebu from Western Kenya

    PubMed Central

    Mbole-Kariuki, M N; Sonstegard, T; Orth, A; Thumbi, S M; Bronsvoort, B M de C; Kiara, H; Toye, P; Conradie, I; Jennings, A; Coetzer, K; Woolhouse, M E J; Hanotte, O; Tapio, M

    2014-01-01

    The Kenyan East African zebu cattle are valuable and widely used genetic resources. Previous studies using microsatellite loci revealed the complex history of these populations with the presence of taurine and zebu genetic backgrounds. Here, we estimate at genome-wide level the genetic composition and population structure of the East African Shorthorn Zebu (EASZ) of western Kenya. A total of 548 EASZ from 20 sub-locations were genotyped using the Illumina BovineSNP50 v. 1 beadchip. STRUCTURE analysis reveals admixture with Asian zebu, African and European taurine cattle. The EASZ were separated into three categories: substantial (⩾12.5%), moderate (1.56%admixture in the EASZ population, subsequently shaped by selection and/or genetic drift, followed by a more recent exotic European cattle introgression. PMID:24736786

  19. The LWb blood group as a marker of prehistoric Baltic migrations and admixture.

    PubMed

    Sistonen, P; Virtaranta-Knowles, K; Denisova, R; Kucinskas, V; Ambrasiene, D; Beckman, L

    1999-06-01

    Archaeological findings and historical records indicate frequent migrations and exchange of genetic material between populations in the Baltic Sea area. However, there have so far been very few attempts to trace migrations in this area using genetic markers. We have studied the Baltic populations with respect to exceptional variations in the frequencies of the Landsteiner-Wiener (LW) blood group. The frequency of the uncommon LWb gene was high in the Balts, around 6% among Latvians and Lithuanians, very low among the other western Europeans (0-0.1%) and apparently absent in Asiatic and African populations. From the Baltic region of peak frequency there was a regular decline of LWb incidence (a descending cline) in the neighboring populations: 4.0% in the Estonians, 2.9% in the Finns, 2. 2% in the Vologda Russians, and 2.0% in the Poles. Thus the distribution of LWb suggests considerable and extensive Baltic admixture, especially in the north and northeast direction. In Southern Sweden with an LWb frequency of 0.3%, the Baltic influence appeared slight, while in the population of the Swedish island Gotland in the middle of the Baltic Sea there was a significantly increased LWb frequency of 1.0% compared with that of Western European countries. The distinction of codominantly inherited LW antigenic forms, LWa and LWb (previously Nea), is known to be due to a single base substitution. Based on our population data, it is plausible that the expansion of this point mutation occurred only once during human history. Furthermore, our data indicate that the expansion of the LWb mutation occurred in Balts and that LWb can be considered a 'Baltic tribal marker', its presence in other populations being an indicator of the degree of Baltic genetic influence. PMID:10364680

  20. Coagulated silica - a-SiO2 admixture in cement paste

    NASA Astrophysics Data System (ADS)

    Pokorný, Jaroslav; Pavlíková, Milena; Záleská, Martina; Rovnaníková, Pavla; Pavlík, Zbyšek

    2016-07-01

    Amorphous silica (a-SiO2) in fine-grained form possesses a high pozzolanic activity which makes it a valuable component of blended binders in concrete production. The origin of a-SiO2 applied in cement-based composites is very diverse. SiO2 in amorphous form is present in various amounts in quite a few supplementary cementing materials (SCMs) being used as partial replacement of Portland cement. In this work, the applicability of a commercially produced coagulated silica powder as a partial replacement of Portland cement in cement paste mix design is investigated. Portland cement CEM I 42.5R produced according to the EU standard EN 197-1 is used as a reference binder. Coagulated silica is applied in dosages of 5 and 10 % by mass of cement. The water/binder ratio is kept constant in all the studied pastes. For the applied silica, specific surface area, density, loss on ignition, pozzolanic activity, chemical composition, and SiO2 amorphous phase content are determined. For the developed pastes on the basis of cement-silica blended binder, basic physical properties as bulk density, matrix density, and total open porosity are accessed. Pore size distribution is determined using MIP analysis. Initial and final setting times of fresh mixtures are measured by automatic Vicat apparatus. Effect of silica admixture on mechanical resistivity is evaluated using compressive strength, bending strength, and dynamic Young's modulus measurement. The obtained data gives evidence of a decreased workability of paste mixtures with silica, whereas the setting process is accelerated. On the other hand, reaction activity of silica with Portland cement minerals results in a slight decrease of porosity and improvement of mechanical resistivity of cement pastes containing a-SiO2.

  1. A study of an orbital radar mapping mission to Venus. Volume 3: Parametric studies and subsystem comparisons

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Parametric studies and subsystem comparisons for the orbital radar mapping mission to planet Venus are presented. Launch vehicle requirements and primary orbiter propulsion system requirements are evaluated. The systems parametric analysis indicated that orbit size and orientation interrelated with almost all of the principal spacecraft systems and influenced significantly the definition of orbit insertion propulsion requirements, weight in orbit capability, radar system design, and mapping strategy.

  2. Studying MAP Kinase pathways during early development of Xenopus laevis.

    PubMed

    Keren, Aviad; Bengal, Eyal

    2010-01-01

    The following chapter describes several methods involved in the detection of MAPK activities and phosphorylated proteins during early development of Xenopus laevis. The Xenopus embryo provides a powerful platform for biochemical studies. We describe here basic methods of embryo manipulations such as egg fertilization, embryo growth and maintenance, microinjection of capped RNA and antisense morpholino oligonucleotides (AMOs), and isolation of explants. In addition, we describe methods to detect phosphorylated proteins, to analyze kinase activity, and to interfere with signaling pathways. Immunohistochemical staining performed on whole embryos or on tissue sections is an additional method for the detection of phosphorylated proteins in the developing embryo. Approaches to activate or inhibit MAPK activities including the ectopic expression of mutated isoforms of MAPK kinase, or the incubation of embryo explants with pharmacological inhibitors are described. Finally, we describe an in vitro kinase assay specifically designed for the Xenopus embryo. PMID:20811998

  3. Multiple Application Propfan Study (MAPS): Advanced tactical transport

    NASA Technical Reports Server (NTRS)

    Newton, F. C.; Liebeck, R. H.; Mitchell, G. H.; Mooiweer, A.; Platte, M. M.; Toogood, T. L.; Wright, R. A.

    1986-01-01

    This study was conducted to ascertain potential benefits of a propfan propulsion system application to a blended wing/body military tactical transport. Based on a design cruise Mach no. of 0.75 for the design mission, the results indicate a significant advantage in various figures of merit for the propfan over those of a comparable technology turbofan. Although the propfan has a 1.6 percent greater takeoff gross weight, its life cycle cost is 5.3 percent smaller, partly because of a 27 percent smaller specific fuel consumption. When employed on alternate missions, the propfan configuration offers significantly improved flexibility and capability: an increase in sea level penetration distance of more than 100 percent, or in time-on-station of 24 percent, or in deployment payload of 38 percent.

  4. Applying Value Stream Mapping Technique for Production Improvement in a Manufacturing Company: A Case Study

    NASA Astrophysics Data System (ADS)

    Jeyaraj, K. L.; Muralidharan, C.; Mahalingam, R.; Deshmukh, S. G.

    2013-01-01

    The purpose of this paper is to explain how value stream mapping (VSM) is helpful in lean implementation and to develop the road map to tackle improvement areas to bridge the gap between the existing state and the proposed state of a manufacturing firm. Through this case study, the existing stage of manufacturing is mapped with the help of VSM process symbols and the biggest improvement areas like excessive TAKT time, production, and lead time are identified. Some modifications in current state map are suggested and with these modifications future state map is prepared. Further TAKT time is calculated to set the pace of production processes. This paper compares the current state and future state of a manufacturing firm and witnessed 20 % reduction in TAKT time, 22.5 % reduction in processing time, 4.8 % reduction in lead time, 20 % improvement in production, 9 % improvement in machine utilization, 7 % improvement in man power utilization, objective improvement in workers skill level, and no change in the product and semi finished product inventory level. The findings are limited due to the focused nature of the case study. This case study shows that VSM is a powerful tool for lean implementation and allows the industry to understand and continuously improve towards lean manufacturing.

  5. Leveraging Functional-Annotation Data in Trans-ethnic Fine-Mapping Studies

    PubMed Central

    Kichaev, Gleb; Pasaniuc, Bogdan

    2015-01-01

    Localization of causal variants underlying known risk loci is one of the main research challenges following genome-wide association studies. Risk loci are typically dissected through fine-mapping experiments in trans-ethnic cohorts for leveraging the variability in the local genetic structure across populations. More recent works have shown that genomic functional annotations (i.e., localization of tissue-specific regulatory marks) can be integrated for increasing fine-mapping performance within single-population studies. Here, we introduce methods that integrate the strength of association between genotype and phenotype, the variability in the genetic backgrounds across populations, and the genomic map of tissue-specific functional elements to increase trans-ethnic fine-mapping accuracy. Through extensive simulations and empirical data, we have demonstrated that our approach increases fine-mapping resolution over existing methods. We analyzed empirical data from a large-scale trans-ethnic rheumatoid arthritis (RA) study and showed that the functional genetic architecture of RA is consistent across European and Asian ancestries. In these data, we used our proposed methods to reduce the average size of the 90% credible set from 29 variants per locus for standard non-integrative approaches to 22 variants. PMID:26189819

  6. Pre-Service Teacher Beliefs on the Antecedents to Bullying: A Concept Mapping Study

    ERIC Educational Resources Information Center

    Lopata, Joel A.; Nowicki, Elizabeth A.

    2014-01-01

    In this study, researchers gathered Canadian pre-service teachers' beliefs on the antecedents to bullying. Concept mapping (Kane & Trochim, 2007) was used to analyze the data. This study's findings identified pre-service teachers to have accurate beliefs, inaccurate beliefs, and a lack of knowledge about the antecedents to bullying. Concept…

  7. Mapping the Journey from Home to School: A Study on Children's Representation of Space

    ERIC Educational Resources Information Center

    Thommen, Evelyne; Avelar, Silvania; Sapin, Veronique Zbinden; Perrenoud, Silvia; Malatesta, Dominique

    2010-01-01

    This paper describes a study conducted with 235 children from Brazil and Switzerland. The children, from 5 to 13 years of age, were asked to draw the journey they undertake every day from home to school. The purpose of the study is to understand the relationship between the cognitive development and map-drawing abilities of children in both…

  8. The Social Maps of Children Approaching Adolescence: Studying the Ecology of Youth Development.

    ERIC Educational Resources Information Center

    Garbarino, James; And Others

    This paper reports the first results of a three-year longitudinal study of the social maps of children beginning the transition to adolescence. This exploratory study is guided by Bronfenbrenner's conception of the ecology of human development stressing the importance of a phenomenological orientation to development in the context of ecological…

  9. Mapping Depression in Schizophrenia: A Functional Magnetic Resonance Imaging Study

    PubMed Central

    Kumari, Veena; Peters, Emmanuelle; Guinn, Ashley; Fannon, Dominic; Russell, Tamara; Sumich, Alexander; Kuipers, Elizabeth; Williams, Steven C. R.; ffytche, Dominic H.

    2016-01-01

    Depressive symptoms are common in schizophrenia, often left untreated, and associated with a high relapse rate, suicidal ideation, increased mortality, reduced social adjustment and poor quality of life. The neural mechanisms underlying depression in psychosis are poorly understood. Given reports of altered brain response to negative facial affect in depressive disorders, we examined brain response to emotive facial expressions in relation to levels of depression in people with psychosis. Seventy outpatients (final N = 63) and 20 healthy participants underwent functional magnetic resonance imaging during an implicit affect processing task involving presentation of facial expressions of fear, anger, happiness as well as neutral expressions and a (no face) control condition. All patients completed Beck Depression Inventory (BDI-II) and had their symptoms assessed on the Positive and Negative Syndrome Scale (PANSS). In patients, depression (BDI-II) scores associated positively with activation of the left thalamus, extending to the putamen-globus pallidus, insula, inferior-middle frontal and para-post-pre-central gyri during fearful expressions. Furthermore, patients with moderate-to-severe depression had significantly higher activity in these brain regions during fearful expressions relative to patients with no, minimal, or mild depression and healthy participants. The study provides first evidence of enhanced brain response to fearful facial expressions, which signal an uncertain source of threat in the environment, in patients with psychosis and a high level of self-reported depression. PMID:26712855

  10. Mapping Depression in Schizophrenia: A Functional Magnetic Resonance Imaging Study.

    PubMed

    Kumari, Veena; Peters, Emmanuelle; Guinn, Ashley; Fannon, Dominic; Russell, Tamara; Sumich, Alexander; Kuipers, Elizabeth; Williams, Steven C R; Ffytche, Dominic H

    2016-05-01

    Depressive symptoms are common in schizophrenia, often left untreated, and associated with a high relapse rate, suicidal ideation, increased mortality, reduced social adjustment and poor quality of life. The neural mechanisms underlying depression in psychosis are poorly understood. Given reports of altered brain response to negative facial affect in depressive disorders, we examined brain response to emotive facial expressions in relation to levels of depression in people with psychosis. Seventy outpatients (final N= 63) and 20 healthy participants underwent functional magnetic resonance imaging during an implicit affect processing task involving presentation of facial expressions of fear, anger, happiness as well as neutral expressions and a (no face) control condition. All patients completed Beck Depression Inventory (BDI-II) and had their symptoms assessed on the Positive and Negative Syndrome Scale (PANSS). In patients, depression (BDI-II) scores associated positively with activation of the left thalamus, extending to the putamen-globus pallidus, insula, inferior-middle frontal and para-post-pre-central gyri during fearful expressions. Furthermore, patients with moderate-to-severe depression had significantly higher activity in these brain regions during fearful expressions relative to patients with no, minimal, or mild depression and healthy participants. The study provides first evidence of enhanced brain response to fearful facial expressions, which signal an uncertain source of threat in the environment, in patients with psychosis and a high level of self-reported depression. PMID:26712855

  11. Outdoor Noise Pollution Mapping Case Study: A District of Tehran

    NASA Astrophysics Data System (ADS)

    Monazzam, Mohammad Reza; Karimi, Elham; Nassiri, Parvin; Taghavi, Lobat; Karbalaei, Samaneh

    2014-10-01

    The main objective of this study was to investigate the noise levels at different land uses of District 14 in Tehran. For this purpose, a total number of 91 sampling stations were selected. Afterwards, the equivalent sound pressure level in each station was measured at three occasions of morning (7-9 am), noon (12-3 pm), and evening (5-8 pm). Based on the conformability requirement of each land uses, noise levels was divided in three zones wherein the land uses are exposed to different noise levels was estimated. The obtained results indicated that 8.79% of 78 land uses (residential, recreational and medical) in the Zone 1 were exposed to acceptable range of sound pressure level while the rest suffers from unacceptable noise levels. Among 10 land uses of Zone 2 (commercial-residential), 2.19% were within the acceptable range and 8.78% were in unacceptable range. None of the three land uses in Zone 3 were within the acceptable range. Accordingly, the Zone 3 was recognized to be in a critical condition. In other words, about 88.99% of the total and uses in the Zone 3 is exposed to unaccepted able noise level. Comparing with the standard equivalent sound pressure level of 55 dB(A) presented, the residential land use with the equivalent sound pressure level of 19.27 dB(A) accounted for the highest standard deviation. This is due to proximity of most of the residential areas to the crowded highways and streets.

  12. A Study of Concept Mapping as an Instructional Intervention in an Undergraduate General Chemistry Calorimetry Laboratory

    NASA Astrophysics Data System (ADS)

    Stroud, Mary W.

    This investigation, rooted in both chemistry and education, considers outcomes occurring in a small-scale study in which concept mapping was used as an instructional intervention in an undergraduate calorimetry laboratory. A quasi-experimental, multiple-methods approach was employed since the research questions posed in this study warranted the use of both qualitative and quantitative perspectives and evaluations. For the intervention group of students, a convenience sample, post-lab concept maps, written discussions, quiz responses and learning surveys were characterized and evaluated. Archived quiz responses for non-intervention students were also analyzed for comparison. Students uniquely constructed individual concept maps containing incorrect, conceptually correct and "scientifically thin" calorimetry characterizations. Students more greatly emphasized mathematical relationships and equations utilized during the calorimetry experiment; the meaning of calorimetry concepts was demonstrated to a lesser extent.

  13. Computer-assisted photogrammetric mapping systems for geologic studies-A progress report

    USGS Publications Warehouse

    Pillmore, C.L.; Dueholm, K.S.; Jepsen, H.S.; Schuch, C.H.

    1981-01-01

    Photogrammetry has played an important role in geologic mapping for many years; however, only recently have attempts been made to automate mapping functions for geology. Computer-assisted photogrammetric mapping systems for geologic studies have been developed and are currently in use in offices of the Geological Survey of Greenland at Copenhagen, Denmark, and the U.S. Geological Survey at Denver, Colorado. Though differing somewhat, the systems are similar in that they integrate Kern PG-2 photogrammetric plotting instruments and small desk-top computers that are programmed to perform special geologic functions and operate flat-bed plotters by means of specially designed hardware and software. A z-drive capability, in which stepping motors control the z-motions of the PG-2 plotters, is an integral part of both systems. This feature enables the computer to automatically position the floating mark on computer-calculated, previously defined geologic planes, such as contacts or the base of coal beds, throughout the stereoscopic model in order to improve the mapping capabilities of the instrument and to aid in correlation and tracing of geologic units. The common goal is to enhance the capabilities of the PG-2 plotter and provide a means by which geologists can make conventional geologic maps more efficiently and explore ways to apply computer technology to geologic studies. ?? 1981.

  14. Direct-to-Consumer Racial Admixture Tests and Beliefs About Essential Racial Differences

    PubMed Central

    Phelan, Jo C.; Link, Bruce G.; Zelner, Sarah; Yang, Lawrence H.

    2015-01-01

    Although at first relatively disinterested in race, modern genomic research has increasingly turned attention to racial variations. We examine a prominent example of this focus—direct-to-consumer racial admixture tests—and ask how information about the methods and results of these tests in news media may affect beliefs in racial differences. The reification hypothesis proposes that by emphasizing a genetic basis for race, thereby reifying race as a biological reality, the tests increase beliefs that whites and blacks are essentially different. The challenge hypothesis suggests that by describing differences between racial groups as continua rather than sharp demarcations, the results produced by admixture tests break down racial categories and reduce beliefs in racial differences. A nationally representative survey experiment (N = 526) provided clear support for the reification hypothesis. The results suggest that an unintended consequence of the genomic revolution may be to reinvigorate age-old beliefs in essential racial differences. PMID:25870464

  15. Consequences of meta-stable (177m)Lu admixture in (177)Lu for patient dosimetry.

    PubMed

    Konijnenberg, Mark W

    2015-01-01

    Lutetium-177 ((177)Lu) is a rare earth metal in the lanthanides series which decays by beta emission with a half life of 6.647 days to three excited states and the ground state of (177)Hf. When (177)Lu is produced by neutron capture in (176)Lu, inevitably an admixture is formed of the long-lived isomer (177)mLu. As its half-life of 160.4 days is so much longer than that of (177)Lu, concerns are raised on its possible enhancement in radiation dose to the patient treated with (177)Lu-DOTA-octreotate. This report evaluates this possible enhancement of the absorbed dose, based on the published pharmacokinetic profile of (177)Lu-DOTA-octreotate and assuming an admixture of 1 kBq (177)mLu /MBq (177)Lu (0.1%). PMID:25771362

  16. Seaside, Oregon, Tsunami Pilot Study-Modernization of FEMA Flood Hazard Maps: GIS Data

    USGS Publications Warehouse

    Wong, Florence L.; Venturato, Angie J.; Geist, Eric L.

    2006-01-01

    Introduction: The Federal Emergency Management Agency (FEMA) Federal Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study (Chowdhury and others, 2005). Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Analysis (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines (Tsunami Pilot Study Working Group, 2006). The Seaside area was chosen because it is typical of many coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca, and because State agencies and local stakeholders expressed considerable interest in mapping the tsunami threat to this area. The study was an interagency effort by FEMA, U.S. Geological Survey, and the National Oceanic and Atmospheric Administration (NOAA), in collaboration with the University of Southern California, Middle East Technical University, Portland State University, Horning Geoscience, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. We present the spatial (geographic information system, GIS) data from the pilot study in standard GIS formats and provide files for visualization in Google Earth, a global map viewer.

  17. Genome-wide association studies in diverse populations

    PubMed Central

    Rosenberg, Noah A; Huang, Lucy; Jewett, Ethan M; Szpiech, Zachary A; Jankovic, Ivana; Boehnke, Michael

    2011-01-01

    Genome-wide association (GWA) studies have identified a large number of single-nucleotide polymorphisms (SNPs) associated with disease phenotypes. As most GWA studies have been performed primarily in populations of European descent, this review examines the issues involved in extending consideration of GWA studies to diverse worldwide populations. Although challenges exist with such issues as imputation, admixture, and replication, investigation of diverse populations in GWA studies has significant potential to advance the project of mapping the genetic determinants of complex diseases for the human population as a whole. PMID:20395969

  18. Mapping perception to action in piano practice: a longitudinal DC-EEG study

    PubMed Central

    Bangert, Marc; Altenmüller, Eckart O

    2003-01-01

    Background Performing music requires fast auditory and motor processing. Regarding professional musicians, recent brain imaging studies have demonstrated that auditory stimulation produces a co-activation of motor areas, whereas silent tapping of musical phrases evokes a co-activation in auditory regions. Whether this is obtained via a specific cerebral relay station is unclear. Furthermore, the time course of plasticity has not yet been addressed. Results Changes in cortical activation patterns (DC-EEG potentials) induced by short (20 minute) and long term (5 week) piano learning were investigated during auditory and motoric tasks. Two beginner groups were trained. The 'map' group was allowed to learn the standard piano key-to-pitch map. For the 'no-map' group, random assignment of keys to tones prevented such a map. Auditory-sensorimotor EEG co-activity occurred within only 20 minutes. The effect was enhanced after 5-week training, contributing elements of both perception and action to the mental representation of the instrument. The 'map' group demonstrated significant additional activity of right anterior regions. Conclusion We conclude that musical training triggers instant plasticity in the cortex, and that right-hemispheric anterior areas provide an audio-motor interface for the mental representation of the keyboard. PMID:14575529

  19. Flood mapping from Sentinel-1 and Landsat-8 data: a case study from river Evros, Greece

    NASA Astrophysics Data System (ADS)

    Kyriou, Aggeliki; Nikolakopoulos, Konstantinos

    2015-10-01

    Floods are suddenly and temporary natural events, affecting areas which are not normally covered by water. The influence of floods plays a significant role both in society and the natural environment, therefore flood mapping is crucial. Remote sensing data can be used to develop flood map in an efficient and effective way. This work is focused on expansion of water bodies overtopping natural levees of the river Evros, invading the surroundings areas and converting them in flooded. Different techniques of flood mapping were used using data from active and passive remote sensing sensors like Sentinlel-1 and Landsat-8 respectively. Space borne pairs obtained from Sentinel-1 were processed in this study. Each pair included an image during the flood, which is called "crisis image" and another one before the event, which is called "archived image". Both images covering the same area were processed producing a map, which shows the spread of the flood. Multispectral data From Landsat-8 were also processed in order to detect and map the flooded areas. Different image processing techniques were applied and the results were compared to the respective results of the radar data processing.

  20. A high-density admixture scan in 1,670 African Americans with hypertension.

    PubMed

    Deo, Rahul C; Patterson, Nick; Tandon, Arti; McDonald, Gavin J; Haiman, Christopher A; Ardlie, Kristin; Henderson, Brian E; Henderson, Sean O; Reich, David

    2007-11-01

    Hypertension (HTN) is a devastating disease with a higher incidence in African Americans than European Americans, inspiring searches for genetic variants that contribute to this difference. We report the results of a large-scale admixture scan for genes contributing HTN risk, in which we screened 1,670 African Americans with HTN and 387 control individuals for regions of the genome with elevated proportion of African or European ancestry. No loci were identified that were significantly associated with HTN. We also searched for evidence of an admixture signal at 40 candidate genes and eight previously reported linkage peaks, but none appears to contribute substantially to the differential HTN risk between African and European Americans. Finally, we observed nominal association at one of the loci detected in the admixture scan of Zhu et al. 2005 (p = 0.016 at 6q24.3 correcting for four hypotheses tested), although we caution that the significance is marginal and the estimated odds ratio of 1.19 per African allele is less than what would be expected from the original report; thus, further work is needed to follow up this locus. PMID:18020707

  1. A Genomic Approach for Distinguishing between Recent and Ancient Admixture as Applied to Cattle

    PubMed Central

    Hillis, David M.

    2014-01-01

    Genomic data facilitate opportunities to track complex population histories of divergence and gene flow. We developed a metric, scaled block size (SBS), which uses the nonrecombined block size of introgressed regions of chromosomes to differentiate between recent and ancient types of admixture, and applied it to the reconstruction of admixture in cattle. Cattle are descendants of 2 independently domesticated lineages, taurine and indicine, which diverged more than 200 000 years ago. Several breeds have hybrid ancestry between these divergent lineages. Using 47 506 single-nucleotide polymorphisms, we analyzed the genomic architecture of the ancestry of 1369 individuals. We focused on 4 groups with admixed ancestry, including 2 anciently admixed African breeds (n = 58; n = 43), New World cattle of Spanish origin (n = 51), and known recent hybrids (n = 46). We estimated the ancestry of chromosomal regions for each individual and used the SBS metric to differentiate the timing of admixture among groups and among individuals within groups. By comparing SBS values of test individuals with standards with known recent hybrid ancestry, we were able to differentiate individuals of recent hybrid origin from other admixed cattle. We also estimated ancestry at the chromosomal scale. The X chromosome exhibits reduced indicine ancestry in recent hybrid, New World, and western African cattle, with virtually no evidence of indicine ancestry in New World cattle. PMID:24510946

  2. A High-Density Admixture Scan in 1,670 African Americans with Hypertension

    PubMed Central

    Deo, Rahul C; Patterson, Nick; Tandon, Arti; McDonald, Gavin J; Haiman, Christopher A; Ardlie, Kristin; Henderson, Brian E; Henderson, Sean O; Reich, David

    2007-01-01

    Hypertension (HTN) is a devastating disease with a higher incidence in African Americans than European Americans, inspiring searches for genetic variants that contribute to this difference. We report the results of a large-scale admixture scan for genes contributing HTN risk, in which we screened 1,670 African Americans with HTN and 387 control individuals for regions of the genome with elevated proportion of African or European ancestry. No loci were identified that were significantly associated with HTN. We also searched for evidence of an admixture signal at 40 candidate genes and eight previously reported linkage peaks, but none appears to contribute substantially to the differential HTN risk between African and European Americans. Finally, we observed nominal association at one of the loci detected in the admixture scan of Zhu et al. 2005 (p = 0.016 at 6q24.3 correcting for four hypotheses tested), although we caution that the significance is marginal and the estimated odds ratio of 1.19 per African allele is less than what would be expected from the original report; thus, further work is needed to follow up this locus. PMID:18020707

  3. Effects of lithium nitrate admixture on early-age cement hydration

    SciTech Connect

    Millard, M.J. Kurtis, K.E.

    2008-04-15

    Although the benefits of lithium admixtures for mitigation of alkali-silica reaction (ASR) have been well documented, the potential ancillary effects of lithium compounds on cement and concrete remain largely uncharacterized. To examine the effects of the most common lithium admixture - lithium nitrate - on early-age behavior, the admixture was introduced at dosages of 0% to 400% of the recommended dosage to six cements of varying composition and to a cement-fly ash blend. Behavior was examined by isothermal calorimetry and measurements of chemical shrinkage, autogenous shrinkage, and setting time. Results indicate that lithium nitrate accelerates the early hydration of most cements but may retard hydration after 24 h. In the lowest alkali cement tested, set times were shortened in the presence of lithium nitrate by 15-22%. Higher dosages appeared to increase autogenous shrinkage after 40 days. The replacement of cement by Class F fly ash at 20% by weight appeared to diminish the early acceleration effects, but later hydration retardation and autogenous shrinkage were still observed.

  4. Showing Where To Go by Maps or Pictures: An Empirical Case Study at Subway Exits

    NASA Astrophysics Data System (ADS)

    Ishikawa, Toru; Yamazaki, Tetsuo

    This study empirically examined the effectiveness of different methods of presenting route information on a mobile navigation sysyem, for accurate and effortless orientation at subway exits. Specifically, it compared participants’ spatial orientation performance with pictures and maps, in relation to the levels of their spatial ability. Participants identified the directions toward the goals after coming onto the ground faster when viewing pictures than when viewing maps. Spatial orientation with maps was more difficult than that with pictures at exits where body rotation was necessary, especially for people with low mental-rotation ability. In contrast, pictures were equally effective for people with low and high mental-rotation ability. Reasons for the effectiveness of pictures and possibilities of using other presentation formats are discussed.

  5. The Study of Insurance Premium Rate GIS Mapping Considering the Storm and Flood Hazard Risks

    NASA Astrophysics Data System (ADS)

    Lee, J. S.; Lee, I. S.

    2016-06-01

    Recently, the number of natural disaster occurrence is increasing because of abnormal changes of weather in Korea. In Korea the storm and flood insurance system is in effect to prevent these natural disasters. The national storm and flood insurance Premium rate is very low and the risk of adverse selection resides because of choosing by who lives in high risk area. To solve these problems, the storm and flood insurance rate map are required. In this study, the prototype of storm and flood insurance premium rate map of the Ulsan, Korea was made and the method of GIS analysis for the insurance premium rate calculating and the procedure of the Ulsan storm and flood insurance rate map were researched.

  6. World Eagle, The Monthly Social Studies Resource: Data, Maps, Graphs. 1990-1991.

    ERIC Educational Resources Information Center

    World Eagle, 1991

    1991-01-01

    This document consists of the 10 issues of "World Eagle" issued during the 1990-1991 school year. World Eagle is a monthly social studies resource in which demographic and geographic information is presented in the forms of maps, graphs, charts, and text. Each issue of World Eagle has a section that focuses on a particular topic, along with other…

  7. Student and Teacher Perceptions of Mind Mapping: A Middle School Case Study.

    ERIC Educational Resources Information Center

    Goodnough, Karen; Woods, Robin

    The use of mind mapping (MM), a visual tool developed by T. Buzan (1983; 1996) to improve note-taking, foster creativity, organize thinking, and develop ideas and concepts, was studied in a sixth-grade classroom with 16 students as an instructional and learning tool. In MM, a central focus or graphic representation of the problem is placed in the…

  8. How Do High-School Students Perceive the Concept of "Map": A Case Study from Istanbul

    ERIC Educational Resources Information Center

    Ozder, Adem

    2013-01-01

    The main aim of this study is investigating metaphors developed by the students regarding the concept of "map" at private institutions which provide them with specialized courses (Dershane). About 338 students in one of these private courses in Istanbul city center accepted to participate in the research within 2012 to 2013 academic…

  9. Combining Mapping and Citation Analysis for Evaluative Bibliometric Purposes: A Bibliometric Study.

    ERIC Educational Resources Information Center

    Noyons, E. C. M; Moed, H. F.; Luwel, M.

    1999-01-01

    Presents the results of a combined performance/mapping study used to evaluate a Belgian research institute in microelectronics. Results from one bibliometric approach were used to validate results of another. Findings indicated that the method provides a detailed and useful picture of the position of the institute from an international…

  10. 78 FR 76888 - MAP-21 Comprehensive Truck Size and Weight Limits Study Materials

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-19

    ... were referenced in a notice published on November 29, 2013, at 78 FR 71707. The original meeting notice..., 2013, at 78 FR 71707, the FHWA published in the Federal Register a notice to announce two upcoming... Federal Highway Administration MAP-21 Comprehensive Truck Size and Weight Limits Study Materials...

  11. A Hundred and One Satellite Map Bargains for Social Studies Teachers.

    ERIC Educational Resources Information Center

    Kirman, Joseph M.

    1981-01-01

    Recommends that social studies classroom teachers use landsat images in geography units to teach students about map interpretation. Information is presented on interpreting landsat images, uses of landsat images in the classroom, cities for which landsat images are available, and ordering information. (DB)

  12. The Effect of Using Concept Maps as Study Tools on Achievement in Chemistry

    ERIC Educational Resources Information Center

    BouJaoude, Saouma; Attieh, May

    2008-01-01

    The purposes of this study were to: (1) examine whether or not the construction of concept maps by students improves their achievement and ability to solve higher order questions in chemistry, (2) investigate the differential effect of the treatment by gender and achievement level, and (3) explore the relationships between performance on concept…

  13. Concept Mapping in Science Class: A Case Study of Fifth Grade Students

    ERIC Educational Resources Information Center

    Asan, Askin

    2007-01-01

    The purpose of this research project was to determine the effects of incorporating concept mapping on the achievement of fifth grade students in science class. The study was conducted with twenty-three students at Ata Elementary School, Trabzon, Turkey. The students were tested with teacher-constructed pre- and post tests containing 20…

  14. A Study of Kindergarten Children's Spatial Representation in a Mapping Project

    ERIC Educational Resources Information Center

    Davis, Genevieve A.; Hyun, Eunsook

    2005-01-01

    This phenomenological study examined kindergarten children's development of spatial representation in a year long mapping project. Findings and discussion relative to how children conceptualised and represented physical space are presented in light of theoretical notions advanced by Piaget, van Hiele, and cognitive science researchers Battista and…

  15. Presurgical navigated TMS motor cortex mapping improves outcome in glioblastoma surgery: a controlled observational study.

    PubMed

    Picht, Thomas; Frey, Dietmar; Thieme, Stefan; Kliesch, Stefan; Vajkoczy, Peter

    2016-02-01

    The authors report on an observational study designed to isolate the impact of navigated transcranial magnetic stimulation (nTMS) on surgical outcome in glioblastoma treatment. We undertook a controlled observational study to identify the additive impact of presurgical nTMS in patients scheduled for surgical treatment of glioblastoma in or near motor eloquent locations. The trial data is derived from a large university hospital with a differential availability of its nTMS mapping service at its two campuses, both equally served by a single neurosurgical department. When available, the nTMS cortical mapping data and nTMS-based fiber tractography are used for surgical planning and patient counseling as well as intraoperative identification of the primary motor cortex and guidance in subcortical motor mapping. The addition of preoperative nTMS mapping data to a clinical routine already incorporating preoperative fiber tractography and intraoperative neuronavigation and electrophysiology was shown to improve surgical outcomes by increasing the extent of resection, without compromising patient safety or long-term functional outcomes in comparison to the concurrent non-TMS control group. This study is the first to prove that the improved surgical outcomes observed in previous studies after the implementation of nTMS to presurgical work-up are not caused by any overall improvement in patient care or a paradigm shift toward more aggressive resection but by the additional functional data provided by nTMS. PMID:26566653

  16. Chemical stability of ziconotide-clonidine hydrochloride admixtures with and without morphine sulfate during simulated intrathecal administration.

    PubMed

    Shields, David; Montenegro, Rick

    2007-10-01

    Objective.  To determine the stability of ziconotide-clonidine hydrochloride admixtures with and without morphine sulfate during simulated intrathecal infusion under laboratory conditions at 37°. Materials and Methods.  Admixtures of ziconotide (25 µg/mL) and clonidine hydrochloride (2 mg/mL) with and without morphine sulfate (35 mg/mL) were stored in Medtronic SynchroMed® II pumps at 37°. Pumps were sampled immediately after filling and at four additional time points over the course of 28 (ziconotide-clonidine hydrochloride admixture) or 20 (ziconotide-clonidine hydrochloride-morphine sulfate admixture) days. Drug concentrations were determined using high-performance liquid chromatography. Results.  Ziconotide concentration exceeded 97% of initial at all time points when combined with clonidine alone; statistical evaluation indicated that both ziconotide and clonidine concentrations would remain above 90% of initial for more than 60 days. When compounded with both clonidine and morphine, ziconotide and clonidine concentrations declined; statistical evaluation indicated that the ziconotide concentration was 70% of initial after 20 days, and that clonidine would remain 90% stable for 42 days. Morphine was stable in the presence of ziconotide and clonidine. Conclusions.  A ziconotide-clonidine admixture was 90% stable for 60 days (extrapolated), and a ziconotide-clonidine-morphine admixture was 70% stable for 20 days. PMID:22150946

  17. The HapMap and Genome-Wide Association Studies in Diagnosis and Therapy*

    PubMed Central

    Manolio, Teri A.; Collins, Francis S.

    2009-01-01

    The International HapMap Project produced a genome-wide database of human genetic variation for use in genetic association studies of common diseases. The initial output of these studies has been overwhelming, with over 150 risk loci identified in studies of more than 60 common diseases and traits. These associations have suggested previously unsuspected etiologic pathways for common diseases that will be of use in identifying new therapeutic targets and developing targeted interventions based on genetically defined risk. Here we examine the development and application of the HapMap to genome-wide association (GWA) studies; present and future technologies for GWA research; current major efforts in GWA studies; successes and limitations of the GWA approach in identifying polymorphisms related to complex diseases; data release and privacy polices; use of these findings by clinicians, the public, and academic physicians; and sources of ongoing authoritative information on this rapidly evolving field. PMID:19630580

  18. The Design and Use of an Optical Mapping System for the Study of Intracardiac Electrical Signaling

    PubMed Central

    Shrivastav, Maneesh; Ghai, Megan B; Singal, Ashish; Iaizzo, Paul A

    2012-01-01

    Fluorescent optical mapping of electrically active cardiac tissues provides a unique method to examine the excitation wave dynamics of underlying action potentials. Such mapping can be viewed as a bridge between cellular level and organ systems physiology, e.g., by facilitating the development of advanced theoretical concepts of arrhythmia. We present the design and use of a high-speed, high-resolution optical mapping system composed entirely of "off the shelf" components. The electrical design integrates a 256 element photodiode array with a 16 bit data acquisition system. Proper grounding and shielding at various stages of the design reduce electromagnetic interference. Our mechanical design provides flexibility in terms of mounting positions and applications (use for whole heart or tissue preparations), while maintaining precise alignment between all optical components. The system software incorporates a user friendly graphical user interface, e.g., spatially recorded action potentials can be represented as intensity graphs or in strip chart format. Thus, this system is capable of displaying cardiac action potentials with high spatiotemporal resolution. Results from cardiac action potential mapping with intact mouse hearts are provided. It should be noted that this system could be readily configured to study isolated myocardial biopsies (e.g., isolated ventricular trabeculae). We describe the details of a versatile, user-friendly system that could be employed for a magnitude of study protocols. PMID:22912535

  19. Rock type mapping with indices defined for multispectral thermal infrared ASTER data: case studies

    NASA Astrophysics Data System (ADS)

    Ninomiya, Yoshiki

    2003-03-01

    ASTER sensor aboard NASA's Terra satellite has the capability of measuring multispectral thermal infrared (TIR) emission from the earth's surface to space. The author proposed indices by the combination of ASTER-TIR bands for detecting quartz and carbonate minerals, and another index to estimate the abundance of bulk SiO2 content in the surface silicate rocks, applied them to the low level ASTER radiance at the sensor data without atmospheric corrections, and showed a potential ability of the indices in a rock type mapping. This paper tries to apply the proposed method into the practical case studies using ASTER-TIR data. The study sites include ophiolitic belt zones in Oman and along Yarlun Zangbo River in Tibet. The applied results are compared with the geology of the study areas. It indicates that the new remote sensing approach proposed here would improve the quality and the cost of the geological mapping in arid and semi-arid regions.

  20. Retrieval practice produces more learning than elaborative studying with concept mapping.

    PubMed

    Karpicke, Jeffrey D; Blunt, Janell R

    2011-02-11

    Educators rely heavily on learning activities that encourage elaborative studying, whereas activities that require students to practice retrieving and reconstructing knowledge are used less frequently. Here, we show that practicing retrieval produces greater gains in meaningful learning than elaborative studying with concept mapping. The advantage of retrieval practice generalized across texts identical to those commonly found in science education. The advantage of retrieval practice was observed with test questions that assessed comprehension and required students to make inferences. The advantage of retrieval practice occurred even when the criterial test involved creating concept maps. Our findings support the theory that retrieval practice enhances learning by retrieval-specific mechanisms rather than by elaborative study processes. Retrieval practice is an effective tool to promote conceptual learning about science. PMID:21252317

  1. Investigating Word Learning in Fragile X Syndrome: A Fast-Mapping Study

    PubMed Central

    McDuffie, Andrea; Kover, Sara T.; Hagerman, Randi; Abbeduto, Leonard

    2012-01-01

    Fast-mapping paradigms have not been used previously to examine the process of word learning in boys with fragile X syndrome (FXS), who are likely to have intellectual impairment, language delays, and symptoms of autism. In this study, a fast-mapping task was used to investigate associative word learning in 4- to 10-year-old boys with FXS relative to younger typically developing boys and age-matched boys with autism spectrum disorders (ASD). Task performance exceeded chance levels for all groups; however, boys with FXS outperformed boys with ASD, despite having lower levels of nonverbal cognition. Memory task demands significantly impacted performance only for boys with typical development. For boys with FXS or ASD, fast-mapping uniquely accounted for small but significant variance in concurrent levels of vocabulary comprehension as did chronological age and nonverbal IQ, but not autism severity. Understanding the fast-mapping process has implications for designing interventions to support word learning and language acquisition in these populations. PMID:23179343

  2. Linkage disequilibrium fine mapping of quantitative trait loci: A simulation study

    PubMed Central

    Abdallah, Jihad M; Goffinet, Bruno; Cierco-Ayrolles, Christine; Pérez-Enciso, Miguel

    2003-01-01

    Recently, the use of linkage disequilibrium (LD) to locate genes which affect quantitative traits (QTL) has received an increasing interest, but the plausibility of fine mapping using linkage disequilibrium techniques for QTL has not been well studied. The main objectives of this work were to (1) measure the extent and pattern of LD between a putative QTL and nearby markers in finite populations and (2) investigate the usefulness of LD in fine mapping QTL in simulated populations using a dense map of multiallelic or biallelic marker loci. The test of association between a marker and QTL and the power of the test were calculated based on single-marker regression analysis. The results show the presence of substantial linkage disequilibrium with closely linked marker loci after 100 to 200 generations of random mating. Although the power to test the association with a frequent QTL of large effect was satisfactory, the power was low for the QTL with a small effect and/or low frequency. More powerful, multi-locus methods may be required to map low frequent QTL with small genetic effects, as well as combining both linkage and linkage disequilibrium information. The results also showed that multiallelic markers are more useful than biallelic markers to detect linkage disequilibrium and association at an equal distance. PMID:12939203

  3. GIS data for the Seaside, Oregon, Tsunami Pilot Study to modernize FEMA flood hazard maps

    USGS Publications Warehouse

    Wong, Florence L.; Venturato, Angie J.; Geist, Eric L.

    2007-01-01

    A Tsunami Pilot Study was conducted for the area surrounding the coastal town of Seaside, Oregon, as part of the Federal Emergency Management's (FEMA) Flood Insurance Rate Map Modernization Program (Tsunami Pilot Study Working Group, 2006). The Cascadia subduction zone extends from Cape Mendocino, California, to Vancouver Island, Canada. The Seaside area was chosen because it is typical of many coastal communities subject to tsunamis generated by far- and near-field (Cascadia) earthquakes. Two goals of the pilot study were to develop probabilistic 100-year and 500-year tsunami inundation maps using Probabilistic Tsunami Hazard Analysis (PTHA) and to provide recommendations for improving tsunami hazard assessment guidelines for FEMA and state and local agencies. The study was an interagency effort by the National Oceanic and Atmospheric Administration, U.S. Geological Survey, and FEMA, in collaboration with the University of Southern California, Middle East Technical University, Portland State University, Horning Geoscience, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. The pilot study model data and results are published separately as a geographic information systems (GIS) data report (Wong and others, 2006). The flood maps and GIS data are briefly described here.

  4. Chloroplast heterogeneity and historical admixture within the genus Malus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Premise of the study: We examined chloroplast DNA sequence variation in 412 samples representing 30 Malus species (including Malus x domestica Borkh.). Malus wild species are of particular interest for providing novel alleles and traits in apple breeding programs, yet the taxonomic status of these s...

  5. Genetic Admixture and Flavor Preferences: Androstenone Sensitivity in Malagasy Populations.

    PubMed

    Razafindrazaka, Harilanto; Monnereau, Aurore; Razafindrazaka, Dina; Tonasso, Laure; Schiavinato, Stephanie; Rakotoarisoa, Jean-Aimé; Radimilahy, Chantal; Letellier, Thierry; Pierron, Denis

    2015-01-01

    The genetic basis of androstenone anosmia has been well studied due to androstenone's putative role as a human sex pheromone and its presence in pork meat. Polymorphisms have been identified on the olfactory receptor gene OR7D4, which significantly affect perception of androstenone pleasantness and intensity in several Western populations. This study aims to investigate androstenone sensitivity and the influence of OR7D4 polymorphisms in non-Western populations. Androstenone perception was tested in 132 individuals from Madagascar using a double three-alternative choice test with two concentrations of androstenone (0.17 and 1.7 µg/ml). We found that Malagasy populations described this molecule in a similar way to European populations, and 21% of the sample was not able to smell androstenone. In contrast to previous studies, there was no significant evidence of the influence of rs61729907: C>T (R88W) and rs5020278: C>T polymorphisms (T133M) on androstenone sensitivity in Malagasy populations. We found, however, a significant effect of the polymorphism rs61732668 (P79L) and a significant difference in androstenone perception between populations in different locations across Madagascar. This study indicates the existence of population-specific factors in androstenone sensitivity, suggesting that population history has a role in shaping an individual's smell and flavor preferences and food preferences in general. PMID:26416322

  6. A S[t]imulating Study of Map Projections: An Exploration Integrating Mathematics and Social Studies.

    ERIC Educational Resources Information Center

    Wilkins, Jesse L. M.; Hicks, David

    2001-01-01

    Presents a map-projection activity that combines mathematics and geography through investigating the proportion of land and water that covers the earth. Focuses on helping students become familiar with characteristics of different projections or representations of the world while estimating and graphing and encouraging them to investigate the…

  7. Two-locus admixture linkage analysis of bipolar and unipolar affective disorder supports the presence of susceptibility loci on chromosomes 11p15 and 21q22

    SciTech Connect

    Smyth, C.; Kalsi, G.; O`Neill, J.

    1997-02-01

    Following a report of a linkage study that yielded evidence for a susceptibility locus for bipolar affective disorder on the long arm of chromosome 21, we studied 23 multiply affected pedigrees collected from Iceland and the UK, using the markers PFKL, D21S171, and D21S49. Counting only bipolar cases as affected, a two-point LOD of 1.28 was obtained using D21S171 ({theta} = 0.01, {alpha} = 0.35), with three Icelandic families producing LODs of 0.63, 0.62, and 1.74 (all at {theta} = 0.0). Affected sib pair analysis demonstrated increased allele sharing at D21S171 (P = 0.001) when unipolar cases were also considered affected. The same set of pedigrees had previously been typed for a tyrosine hydroxylase gene (TH) polymorphism at 11p15 and had shown some moderate evidence for linkage. When information from TH and the 21q markers was combined in a two-locus admixture analysis, an overall admixture LOD of 3.87 was obtained using the bipolar affection model. Thus the data are compatible with the hypothesis that a locus at or near TH influences susceptibility in some pedigrees, while a locus near D21S171 is active in others. Similar analyses in other datasets should be carried out to confirm or refute our tentative finding. 66 refs., 3 tabs.

  8. The Effectiveness of Panoramic Maps Design: a Preliminary Study Based on Mobile Eye-Tracking

    NASA Astrophysics Data System (ADS)

    Balzarini, R.; Murat, M.

    2016-06-01

    This paper presents preliminary results from an ongoing research based on the study of visual attention through mobile eye-tracking techniques. The visual-cognitive approach investigates the reading-comprehension of a particular territorial representation: ski trails maps. The general issue of the study is to provide insights about the effectiveness of panoramic ski maps and more broadly, to suggest innovative efficient representation of the geographic information in mountain. According to some mountain operators, the information provided by paper ski maps no longer meets the needs of a large part of the customers; the question now arises of their adaptation to new digital practices (iPhone, tablets). In a computerized process perspective, this study particularly focuses on the representations, and the inferred information, which are really helpful to the users-skiers to apprehend the territory and make decisions, and which could be effectively replicated into a digital system. The most interesting output relies on the relevance of the panorama view: panorama still fascinates, but contrary to conventional wisdom, the information it provides does not seem to be useful to the skier. From a socio-historical perspective this study shows how empirical evidence-based approach can support the change: our results enhance the discussion on the effectiveness of the message that mountain operators want to convey to the tourist and therefore, on the renewal of (geographical) information in ski resorts.

  9. Structural mapping from MSS-LANDSAT imagery: A proposed methodology for international geological correlation studies

    NASA Technical Reports Server (NTRS)

    Dejesusparada, N. (Principal Investigator); Crepani, E.; Martini, P. R.

    1980-01-01

    A methodology is proposed for international geological correlation studies based on LANDSAT-MSS imagery, Bullard's model of continental fit and compatible structural trends between Northeast Brazil and the West African counterpart. Six extensive lineaments in the Brazilian study area are mapped and discussed according to their regional behavior and in relation to the adjacent continental margin. Among the first conclusions, correlations were found between the Sobral Pedro II Lineament and the megafaults that surround the West African craton; and the Pernambuco Lineament with the Ngaurandere Linemanet in Cameroon. Ongoing research to complete the methodological stages includes the mapping of the West African structural framework, reconstruction of the pre-drift puzzle, and an analysis of the counterpart correlations.

  10. The plant cytoskeleton: recent advances in the study of the plant microtubule-associated proteins MAP-65, MAP-190 and the Xenopus MAP215-like protein, MOR1.

    PubMed

    Hussey, Patrick J; Hawkins, Timothy J; Igarashi, Hisako; Kaloriti, Despina; Smertenko, Andrei

    2002-12-01

    The microtubule cytoskeleton is a dynamic filamentous structure involved in many key processes in plant cell morphogenesis including nuclear and cell division, deposition of cell wall, cell expansion, organelle movement and secretion. The principal microtubule protein is tubulin, which associates to form the wall of the tubule. In addition, various associated proteins bind microtubules either to anchor, cross-link or regulate the microtubule network within cells. Biochemical, molecular biological and genetic approaches are being successfully used to identify these microtubule-associated proteins (MAPs) in plants, and we describe recent progress on three of these proteins. PMID:12516862

  11. A study of an orbital radar mapping mission to Venus. Volume 1: Summary

    NASA Technical Reports Server (NTRS)

    1973-01-01

    A preliminary design of a Venus radar mapping orbiter mission and spacecraft was developed. The important technological problems were identified and evaluated. The study was primarily concerned with trading off alternate ways of implementing the mission and examining the most attractive concepts in order to assess technology requirements. Compatible groupings of mission and spacecraft parameters were analyzed by examining the interaction of their functioning elements and assessing their overall cost effectiveness in performing the mission.

  12. Contemporary approaches to studying and mapping of active water exchange zone of ground water

    NASA Astrophysics Data System (ADS)

    Moraru, C. Ye

    2016-03-01

    The article deals with a zone of ground water active exchange. New principles of the zone study and mapping under the platform hydrogeological condition are discussed. The assessment and distribution techniques are suggested for the active water exchange zone under the condition of hydrogeological parameterization uncertainty. The efficiency and significance of the suggested techniques are proved using the example of ground water in the southwest of Black Sea artesian basin.

  13. Introgressive hybridization and latitudinal admixture clines in North Atlantic eels

    PubMed Central

    2014-01-01

    Background Hybridization, the interbreeding of diagnosably divergent species, is a major focus in evolutionary studies. Eels, both from North America and Europe migrate through the Atlantic to mate in a vast, overlapping area in the Sargasso Sea. Due to the lack of direct observation, it is unknown how these species remain reproductively isolated. The detection of inter-species hybrids in Iceland suggests on-going gene flow, but few studies to date have addressed the influence of introgression on genetic differentiation in North Atlantic eels. Results Here, we show that while mitochondrial lineages remain completely distinct on both sides of the Atlantic, limited hybridization is detectable with nuclear DNA markers. The nuclear hybridization signal peaks in the northern areas and decreases towards the southern range limits on both continents according to Bayesian assignment analyses. By simulating increasing proportions of both F1 hybrids and admixed individuals from the southern to the northern-most locations, we were able to generate highly significant isolation-by-distance patterns in both cases, reminiscent of previously published data for the European eel. Finally, fitting an isolation-with-migration model to our data supports the hypothesis of recent asymmetric introgression and refutes the alternative hypothesis of ancient polymorphism. Conclusions Fluctuating degrees of introgressive hybridization between Atlantic eel species are sufficient to explain temporally varying correlations of geographic and genetic distances reported for populations of the European eel. PMID:24674242

  14. Origins, admixture and founder lineages in European Roma.

    PubMed

    Martínez-Cruz, Begoña; Mendizabal, Isabel; Harmant, Christine; de Pablo, Rosario; Ioana, Mihai; Angelicheva, Dora; Kouvatsi, Anastasia; Makukh, Halyna; Netea, Mihai G; Pamjav, Horolma; Zalán, Andrea; Tournev, Ivailo; Marushiakova, Elena; Popov, Vesselin; Bertranpetit, Jaume; Kalaydjieva, Luba; Quintana-Murci, Lluis; Comas, David

    2016-06-01

    The Roma, also known as 'Gypsies', represent the largest and the most widespread ethnic minority of Europe. There is increasing evidence, based on linguistic, anthropological and genetic data, to suggest that they originated from the Indian subcontinent, with subsequent bottlenecks and undetermined gene flow from/to hosting populations during their diaspora. Further support comes from the presence of Indian uniparentally inherited lineages, such as mitochondrial DNA M and Y-chromosome H haplogroups, in a significant number of Roma individuals. However, the limited resolution of most genetic studies so far, together with the restriction of the samples used, have prevented the detection of other non-Indian founder lineages that might have been present in the proto-Roma population. We performed a high-resolution study of the uniparental genomes of 753 Roma and 984 non-Roma hosting European individuals. Roma groups show lower genetic diversity and high heterogeneity compared with non-Roma samples as a result of lower effective population size and extensive drift, consistent with a series of bottlenecks during their diaspora. We found a set of founder lineages, present in the Roma and virtually absent in the non-Roma, for the maternal (H7, J1b3, J1c1, M18, M35b, M5a1, U3, and X2d) and paternal (I-P259, J-M92, and J-M67) genomes. This lineage classification allows us to identify extensive gene flow from non-Roma to Roma groups, whereas the opposite pattern, although not negligible, is substantially lower (up to 6.3%). Finally, the exact haplotype matching analysis of both uniparental lineages consistently points to a Northwestern origin of the proto-Roma population within the Indian subcontinent. PMID:26374132

  15. Seaside, Oregon Tsunami Pilot Study - modernization of FEMA flood hazard maps

    USGS Publications Warehouse

    Tsunami Pilot Study Working Group

    2006-01-01

    FEMA Flood Insurance Rate Map (FIRM) guidelines do not currently exist for conducting and incorporating tsunami hazard assessments that reflect the substantial advances in tsunami research achieved in the last two decades; this conclusion is the result of two FEMA-sponsored workshops and the associated Tsunami Focused Study. Therefore, as part of FEMA's Map Modernization Program, a Tsunami Pilot Study was carried out in the Seaside/Gearhart, Oregon, area to develop an improved Probabilistic Tsunami Hazard Assessment (PTHA) methodology and to provide recommendations for improved tsunami hazard assessment guidelines. The Seaside area was chosen because it is typical of many coastal communities in the section of the Pacific Coast from Cape Mendocino to the Strait of Juan de Fuca, and because State Agencies and local stakeholders expressed considerable interest in mapping the tsunami threat to this area. The study was an interagency effort by FEMA, U.S. Geological Survey and the National Oceanic and Atmospheric Administration, in collaboration with the University of Southern California, Middle East Technical University. Portland State University, Horning Geosciences, Northwest Hydraulics Consultants, and the Oregon Department of Geological and Mineral Industries. Draft copies and a briefing on the contents, results and recommendations of this document were provided to FEMA officials before final publication.

  16. BOREAS HYD-9 Hourly and Daily Rainfall Maps for the Southern Study Area

    NASA Technical Reports Server (NTRS)

    Eley, F. Joe; Hall, Forrest G. (Editor); Knapp, David E. (Editor); Krauss, Terry S.; Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Hydrology (HYD)-9 team collected data on precipitation and streamflow over portions of the Northern Study Area (NSA) and Southern Study Area (SSA). This data set contains Cartesian maps of rain accumulation for one-hour and daily periods during the summer of 1994 over the SSA only (not the full view of the radar). A parallel set of one-hour maps for the whole radar view has been prepared and is available upon request from the HYD-09 personnel. An incidental benefit of the areal selection was the elimination of some of the less accurate data, because for various reasons the radar rain estimates degrade considerably outside a range of about 100 km. The data are available in tabular ASCII files. The HYD-09 hourly and daily radar rainfall maps for the SSA are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  17. ATR-FTIR microscopy in mapping mode for the study of verdigris and its secondary products

    NASA Astrophysics Data System (ADS)

    Prati, S.; Bonacini, I.; Sciutto, G.; Genty-Vincent, A.; Cotte, M.; Eveno, M.; Menu, M.; Mazzeo, R.

    2016-01-01

    To study degradation processes occurring on painting materials, the use of high-resolution micro-analytical techniques is highly requested since it provides a detailed identification and localisation of both the original and deteriorated ingredients. Among the various pigments recently studied, the characterisation of verdigris has received a major interest. This pigment has not a unique chemical formula, but its composition depends on the recipe employed for its manufacturing. Moreover, verdigris paints are not stable and are subject to a colour change from blue-green to green, which occurs in the first few months after the application. In this paper, we focused our attention on the use of ATR-FTIR mapping as a useful method to identify verdigris secondary products and pathways. Several mock-ups and real samples have been analysed, and the correlation among the detected compounds and their spatial location, obtained by the application of ATR-FTIR microscopy in mapping mode, allowed formulating some hypotheses on the degradation pattern of verdigris, which may feed the discussion on the transformation and stability of this pigment. From an analytical point of view, we showed how FTIR mapping approaches may be extremely useful both for the identification of compounds in complex matrix in which single spectra may limit the exhaustive characterisations due to bands overlapping and for the study of degradation pathways by taking into consideration the relative distribution of degradation products.

  18. Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change.

    PubMed

    Miller, Webb; Schuster, Stephan C; Welch, Andreanna J; Ratan, Aakrosh; Bedoya-Reina, Oscar C; Zhao, Fangqing; Kim, Hie Lim; Burhans, Richard C; Drautz, Daniela I; Wittekindt, Nicola E; Tomsho, Lynn P; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Peacock, Elizabeth; Farley, Sean; Sage, George K; Rode, Karyn; Obbard, Martyn; Montiel, Rafael; Bachmann, Lutz; Ingólfsson, Olafur; Aars, Jon; Mailund, Thomas; Wiig, Oystein; Talbot, Sandra L; Lindqvist, Charlotte

    2012-09-01

    Polar bears (PBs) are superbly adapted to the extreme Arctic environment and have become emblematic of the threat to biodiversity from global climate change. Their divergence from the lower-latitude brown bear provides a textbook example of rapid evolution of distinct phenotypes. However, limited mitochondrial and nuclear DNA evidence conflicts in the timing of PB origin as well as placement of the species within versus sister to the brown bear lineage. We gathered extensive genomic sequence data from contemporary polar, brown, and American black bear samples, in addition to a 130,000- to 110,000-y old PB, to examine this problem from a genome-wide perspective. Nuclear DNA markers reflect a species tree consistent with expectation, showing polar and brown bears to be sister species. However, for the enigmatic brown bears native to Alaska's Alexander Archipelago, we estimate that not only their mitochondrial genome, but also 5-10% of their nuclear genome, is most closely related to PBs, indicating ancient admixture between the two species. Explicit admixture analyses are consistent with ancient splits among PBs, brown bears and black bears that were later followed by occasional admixture. We also provide paleodemographic estimates that suggest bear evolution has tracked key climate events, and that PB in particular experienced a prolonged and dramatic decline in its effective population size during the last ca. 500,000 years. We demonstrate that brown bears and PBs have had sufficiently independent evolutionary histories over the last 4-5 million years to leave imprints in the PB nuclear genome that likely are associated with ecological adaptation to the Arctic environment. PMID:22826254

  19. Polar and brown bear genomes reveal ancient admixture and demographic footprints of past climate change

    USGS Publications Warehouse

    Miller, Webb; Schuster, Stephan C.; Welch, Andreanna J.; Ratan, Aakrosh; Bedoya-Reina, Oscar C.; Zhao, Fangqing; Kim, Hie Lim; Burhans, Richard C.; Drautz, Daniela I.; Wittekindt, Nicola E.; Tomsho, Lynn P.; Ibarra-Laclette, Enrique; Herrera-Estrella, Luis; Peacock, Elizabeth; Farley, Sean; Sage, George K.; Rode, Karyn; Obbard, Martyn E.; Montiel, Rafael; Bachmann, Lutz; Ingólfsson, Ólafur; Aars, Jon; Mailund, Thomas; Wiig, Øystein; Talbot, Sandra L.; Lindqvist, Charlotte

    2012-01-01

    Polar bears (PBs) are superbly adapted to the extreme Arctic environment and have become emblematic of the threat to biodiversity from global climate change. Their divergence from the lower-latitude brown bear provides a textbook example of rapid evolution of distinct phenotypes. However, limited mitochondrial and nuclear DNA evidence conflicts in the timing of PB origin as well as placement of the species within versus sister to the brown bear lineage. We gathered extensive genomic sequence data from contemporary polar, brown, and American black bear samples, in addition to a 130,000- to 110,000-y old PB, to examine this problem from a genome-wide perspective. Nuclear DNA markers reflect a species tree consistent with expectation, showing polar and brown bears to be sister species. However, for the enigmatic brown bears native to Alaska's Alexander Archipelago, we estimate that not only their mitochondrial genome, but also 5–10% of their nuclear genome, is most closely related to PBs, indicating ancient admixture between the two species. Explicit admixture analyses are consistent with ancient splits among PBs, brown bears and black bears that were later followed by occasional admixture. We also provide paleodemographic estimates that suggest bear evolution has tracked key climate events, and that PB in particular experienced a prolonged and dramatic decline in its effective population size during the last ca. 500,000 years. We demonstrate that brown bears and PBs have had sufficiently independent evolutionary histories over the last 4–5 million years to leave imprints in the PB nuclear genome that likely are associated with ecological adaptation to the Arctic environment.

  20. Admixture and Local Breed Marginalization Threaten Algerian Sheep Diversity

    PubMed Central

    Ciani, Elena; Kdidi, Samia; Aouissat, Miloud; Dhimi, Laziz; Lafri, Mohamed; Maftah, Abderrahman; Mehtar, Nadhira

    2015-01-01

    Due to its geo-climatic conditions, Algeria represents a biodiversity hotspot, with sheep breeds well adapted to a patchwork of extremely heterogeneous harsh habitats. The importance of this peculiar genetic reservoir increases as climate change drives the demand for new adaptations. However, the expansion of a single breed (Ouled-Djellal) which occurred in the last decades has generated a critical situation for the other breeds; some of them are being subjected to uncontrolled cross-breeding with the favored breed and/or to marginalization (effective size contraction). This study investigated genetic diversity within and among six of the nine Algerian breeds, by use of 30 microsatellite markers. Our results showed that, in spite of the census contraction experienced by most of the considered breeds, genetic diversity is still substantial (average gene diversity ranging 0.68 to 0.76) and inbreeding was not identified as a problem. However, two breeds (Rembi and Taâdmit) appeared to have lost most of their genetic originality because of intensive cross-breeding with Ouled-Djellal. Based on the above evidence, we suggest Hamra, Sidaoun, and D’man as breeds deserving the highest priority for conservation in Algeria. PMID:25875832

  1. Admixture and local breed marginalization threaten Algerian sheep diversity.

    PubMed

    Gaouar, Samir Bachir Souheil; Da Silva, Anne; Ciani, Elena; Kdidi, Samia; Aouissat, Miloud; Dhimi, Laziz; Lafri, Mohamed; Maftah, Abderrahman; Mehtar, Nadhira

    2015-01-01

    Due to its geo-climatic conditions, Algeria represents a biodiversity hotspot, with sheep breeds well adapted to a patchwork of extremely heterogeneous harsh habitats. The importance of this peculiar genetic reservoir increases as climate change drives the demand for new adaptations. However, the expansion of a single breed (Ouled-Djellal) which occurred in the last decades has generated a critical situation for the other breeds; some of them are being subjected to uncontrolled cross-breeding with the favored breed and/or to marginalization (effective size contraction). This study investigated genetic diversity within and among six of the nine Algerian breeds, by use of 30 microsatellite markers. Our results showed that, in spite of the census contraction experienced by most of the considered breeds, genetic diversity is still substantial (average gene diversity ranging 0.68 to 0.76) and inbreeding was not identified as a problem. However, two breeds (Rembi and Taâdmit) appeared to have lost most of their genetic originality because of intensive cross-breeding with Ouled-Djellal. Based on the above evidence, we suggest Hamra, Sidaoun, and D'man as breeds deserving the highest priority for conservation in Algeria. PMID:25875832

  2. Genome-wide admixture and ecological niche modelling reveal the maintenance of species boundaries despite long history of interspecific gene flow

    PubMed Central

    De La Torre, Amanda R; Roberts, David R; Aitken, Sally N

    2014-01-01

    The maintenance of species boundaries despite interspecific gene flow has been a continuous source of interest in evolutionary biology. Many hybridizing species have porous genomes with regions impermeable to introgression, conferring reproductive barriers between species. We used ecological niche modelling to study the glacial and postglacial recolonization patterns between the widely hybridizing spruce species Picea glauca and P. engelmannii in western North America. Genome-wide estimates of admixture based on a panel of 311 candidate gene single nucleotide polymorphisms (SNP) from 290 genes were used to assess levels of admixture and introgression and to identify loci putatively involved in adaptive differences or reproductive barriers between species. Our palaeoclimatic modelling suggests that these two closely related species have a long history of hybridization and introgression, dating to at least 21 000 years ago, yet species integrity is maintained by a combination of strong environmental selection and reduced current interspecific gene flow. Twenty loci showed evidence of divergent selection, including six loci that were both Fst outliers and associated with climatic gradients, and fourteen loci that were either outliers or showed associations with climate. These included genes responsible for carbohydrate metabolism, signal transduction and transcription factors. PMID:24597663

  3. Review of studies mapping from quality of life or clinical measures to EQ-5D: an online database.

    PubMed

    Dakin, Helen

    2013-01-01

    Systematic literature searches were conducted to identify studies that conducted statistical mapping to predict EQ-5D utilities or responses from any source instrument and reported the estimated algorithms in sufficient detail to allow other researchers to use them to predict EQ-5D in other studies. Ninety studies reporting 121 mapping algorithms met the inclusion criteria. The studies estimated EQ-5D utilities from 80 source instruments. All but two studies included direct utility mapping to predict EQ-5D utilities, while 20 studies (22%) conducted response mapping to predict responses to each EQ-5D domain. Seventy-two studies (80%) explored ordinary least squares regression and 16 (18%) used censored least absolute deviations (CLAD) models. The details of the studies identified are made available in an online database, which will be updated regularly to enable researchers to easily identify studies that can help them to estimate utilities for economic evaluation. PMID:24010873

  4. An investigation of admixture in an Australian Aboriginal Y-chromosome STR database.

    PubMed

    Taylor, Duncan; Nagle, Nano; Ballantyne, Kaye N; van Oorschot, Roland A H; Wilcox, Stephen; Henry, Julianne; Turakulov, Rust; Mitchell, R John

    2012-09-01

    Y-chromosome specific STR profiling is increasingly used in forensic casework. However, the strong geographic clustering of Y haplogroups can lead to large differences in Y-STR haplotype frequencies between different ethnicities, which may have an impact on database composition in admixed populations. Aboriginal people have inhabited Australia for over 40,000 years and until ∼300 years ago they lived in almost complete isolation. Since the late 18th century Australia has experienced massive immigration, mainly from Europe, although in recent times from more widespread origins. This colonisation resulted in highly asymmetrical admixture between the immigrants and the indigenes. A State jurisdiction within Australia has created an Aboriginal Y-STR database in which assignment of ethnicity was by self-declaration. This criterion means that some males who identify culturally as members of a particular ethnic group may have a Y haplogroup characteristic of another ethnic group, as a result of admixture in their paternal line. As this may be frequent in Australia, an examination of the extent of genetic admixture within the database was performed. A Y haplogroup predictor program was first used to identify Y haplotypes that could be assigned to a European haplogroup. Of the 757 males (589 unique haplotypes), 445 (58.8%) were identified as European (354 haplotypes). The 312 non-assigned males (235 haplotypes) were then typed, in a hierarchical fashion, with a Y-SNP panel that detected the major Y haplogroups, C-S, as well as the Aboriginal subgroup of C, C4. Among these 96 males were found to have non-Aboriginal haplogroups. In total, ∼70% of Y chromosomes in the Aboriginal database could be classed as non-indigenous, with only 169 (129 unique haplotypes) or 22% of the total being associated with haplogroups denoting Aboriginal ancestry, C4 and K* or more correctly K(xL,M,N,O,P,Q,R,S). The relative frequencies of these indigenous haplogroups in South Australia (S

  5. Effects of 2 mass % Si admixture in a laser-produced Fe plasma

    SciTech Connect

    Krasa, Josef; Laska, Leos; Rohlena, Karel; Velyhan, Andriy; Lorusso, Antonella; Nassisi, Vincenzo; Czarnecka, Agata; Parys, Piotr; Ryc, Leszek; Wolowski, Jerzy

    2008-11-10

    Emission of multiply charged ions and soft x-rays from the plasmas produced by laser pulses focused on (111) surface of Fe and Fe-2 mass % Si single crystals is investigated for wavelengths of 1064 and 248 nm and intensities up to {approx_equal}1x10{sup 10} W/cm{sup 2}. It is demonstrated that the Si admixture in the Fe plasma results in a higher emission of Fe{sup q+} ions (1{<=}q{<=}4) but in a markedly lower x-ray emission. The relation of wavelengths and pulse durations of laser beams used is figured in the fluence dependence of the ion emission.

  6. Composts with and without wood ash admixture for the management of tropical acid soils: chemical, physical and microbiological effects

    NASA Astrophysics Data System (ADS)

    Bougnom, B. P.; Insam, H.; Etoa, F. X.

    2009-04-01

    Acid soils generally found in the tropics have a low pH, are poor in organic matter, deficient in Ca2+, Mg+, P, or Mo ; limited in mineralization, nitrification, nodulation, and mycorrhizal infection , suffer from Al or Mn toxicity. Within the framework aiming at using organic wastes and wood ash to overcome soil infertility in tropical acidic soils, a green house experiment was conducted with two acid soils collected from Cameroon (Ferralsol and Acrisol) and amended with three types of compost 3:1(W/W) containing 0 (K0), 8(K8) and 16% (K16) wood ash admixture respectively for two consecutive cycles of 100 days, during which soybean (Glycine max) was grown on the first, the second cycle was left as fallow. Generally the same trends of variation of the physico-chemical parameters were observed in both soils. Addition of organic wastes increased the pH electrical conductivity, soil organic matter, water holding capacity, total Carbone and total nitrogen as compared to the controls. The rate of nitrification highly increased posing the problem of possible leaching of nitrates in the ground water. The cations and micronutrients content followed the same trends. These changes leaded to an increase of the P availability and a decrease of Al toxicity. At the end of the second cycle, generally most of the different parameters slightly decreased except for the electrical conductivity. All composts passed a toxicity test, and the amended soils had significant better fresh and dried plant biomass, the Total nitrogen also significantly increased. Amended soils with K0 generally performed better than those amended with K8 and K16, thinking that their pH (closer to the neutrality) was responsible of these performances, all the parameters were significantly correlated to the pH. K8 and K16 performances could be performed by reducing the added quantities. The study of PCR-DGGE have shown a shift in the fungal and bacterial communities, Ammonia oxidizing bacteria community were

  7. Double precision errors in the logistic map: statistical study and dynamical interpretation.

    PubMed

    Oteo, J A; Ros, J

    2007-09-01

    The nature of the round-off errors that occur in the usual double precision computation of the logistic map is studied in detail. Different iterative regimes from the whole panoply of behaviors exhibited in the bifurcation diagram are examined, histograms of errors in trajectories given, and for the case of fully developed chaos an explicit formula is found. It is shown that the statistics of the largest double precision error as a function of the map parameter is characterized by jumps whose location is determined by certain boundary crossings in the bifurcation diagram. Both jumps and locations seem to present geometric convergence characterized by the two first Feigenbaum constants. Eventually, a comparison with Benford's law for the distribution of the leading digit of compilation of numbers is discussed. PMID:17930330

  8. Synchrotron X-Ray Reciprocal Space Mapping, Topography and Diffraction Resolution Studies of Macromolecular Crystal Quality

    NASA Technical Reports Server (NTRS)

    Boggon, T. J.; Helliwell, J. R.; Judge, Russell A.; Siddons, D. P.; Snell, Edward H.; Stojanoff, V.

    2000-01-01

    A comprehensive study of microgravity and ground grown chicken egg white lysozyme crystals is presented using synchrotron X-ray reciprocal space mapping, topography techniques and diffraction resolution. Microgravity crystals displayed, on average, reduced intrinsic mosaicities but no differences in terms of stress over their earth grown counterparts. Topographic analysis revealed that in the microgravity case the majority of the crystal was contributing to the peak of the reflection at the appropriate Bragg angle. In the earth case at the diffraction peak only a small volume of the crystal contributed to the intensity. The techniques prove to be highly complementary with the reciprocal space mapping providing a quantitative measure of the crystal mosaicity and stress (or variation in lattice spacing) and topography providing a qualitative overall assessment of the crystal in terms of its X-ray diffraction properties. Structural data collection was also carried out both at the synchrotron and in the laboratory.

  9. Ustekinumab Biotherapy and Real-Time Psoriasis Capacitance Mapping: A Pilot Study

    PubMed Central

    Piérard-Franchimont, Claudine; Piérard, Gérald E.

    2012-01-01

    In recent years, the treatment of moderate to severe psoriasis has benefited from the development of targeted biologicals. Assessing this new class of drugs calls for precise modalities of severity/improvement ratings of the disease. Bioengineering-driven dermometrology aims at improving objective and quantitative assessments of disease severity and treatment efficacy. Skin capacitance mapping/imaging is one of those emerging methods. Among its clinical applications, psoriasis capacitance mapping (PCM) was introduced in order to assess both skin scaliness and water trapping inside the stratum corneum (inflammatory serum deposits) on lesional skin. PCM was used for assessing the therapeutic effects of ustekinumab on target lesions of 5 psoriatic patients. The reduction in the inflammatory dampness of the stratum corneum was conveniently seen after a 1-month ustekinumab treatment. The present pilot study suggests that PCM could be used as a fast and convenient method for assessing the anti-inflammatory efficacy of ustekinumab and other biotherapies. PMID:22536025

  10. Historic maps and landscape evolution: a case study in the Little Hungarian Plain

    NASA Astrophysics Data System (ADS)

    Zámolyi, A.; Székely, B.; Draganits, E.; Timár, G.

    2009-04-01

    Georeferenced historic maps provide a useful tool to derive geomorphologic landscape elements largely uninfluenced by anthropogenic activity, thus allowing the study of natural changes in the landscape evolution of increasingly densely populated areas. The study area, the Little Hungarian Plain (LHP), is located at the geologically and geomorphologically highly interesting region at the transition between the mountain chains of the Eastern Alps and the Carpathians. The area, as transport route and exchange zone of goods has had its specific importance since the Neolithic times. Consequently, the environment has been subject to human influence, especially since the onset of the industrial age. Geographically the LHP lies in the vicinity of major settlement areas (Vienna, Bratislava, Sopron, Győr) and stretches from the Leithagebirge, a mountainous area in Eastern Austria, to the City of Győr in Western Hungary. The political division of the area into two separate countries occurred after World War I. Thus, historic mapping in the Habsburg Empire and later in the Austro-Hungarian Monarchy that was organized and conducted before World War I allows a comprehensive overview of the study area. Map sheets of the 2nd Military Survey of the whole Monarchy were mapped in the time from 1807 to 1873 in the area of the entire Empire (Kretschmer et al., 2004). The Kingdom of Hungary, as part of the Empire was mapped in a homogenous campaign in the time from 1819 - 1869. Beside the increasing human impact the area is characterized by active surface processes. The geologic evolution of the Little Hungarian Plain is dominated by tectonic processes related to the lateral extrusion of the Eastern Alps and the acceleration of northward movement of the Carpathians. Subsidence is accommodated mainly along high- and low angle normal faults with a high vertical movement component. Strike-slip movements at these faults are very rare. Most of these processes have been active also in the

  11. A Variational Study of Passive Scalar Decay with the Amplitude Mapping Closure

    NASA Astrophysics Data System (ADS)

    Eyink, Gregory L.

    1997-11-01

    We use the Statistical Rayleigh-Ritz Method (SRRM) to study passive scalar decay. SRRM makes computational use of the exact dynamical equations in regimes currently inaccessible to Direct Numerical Simulation (DNS), by exploiting intuitive guesses or Ansätze for the system statistics ( G. L. Eyink, Phys. Rev. E, 54) 3419 (1996). The method is applied here to the advection-diffusion equations within the amplitude mapping closure (H. Chen, S. Chen, and R. H. Kraichnan, Phys. Rev. Lett. 63) 2657 (1989). We derive all multi-time scalar correlations simultaneously by studying the statistical histories of the ``fine-grained'' or ``empirical'' PDF. For this quantity we derive an effective action of Onsager-Machlup type, formally equivalent to a stochastic Langevin model. The amplitude mapping Ansatz is shown to lead to a realizability failure for predicted multi-time statistics, due to the arbitrariness of scalar decay rate. Because this realizability breakdown is restricted to moments of quadratic order or lower, it is still meaningful to compare with experiment for higher moments. For mapping closure with a time-dependent Gaussian reference field (S. Girimaji, Phys. Fluids A 4) 2875 (1992), we present analytical solutions of joint two-time PDF's of the scalar with an initial PDF either Gaussian or double-delta.

  12. Subsidence activity maps derived from DInSAR data: Orihuela case study

    NASA Astrophysics Data System (ADS)

    Sanabria, M. P.; Guardiola-Albert, C.; Tomás, R.; Herrera, G.; Prieto, A.; Sánchez, H.; Tessitore, S.

    2014-05-01

    A new methodology is proposed to produce subsidence activity maps based on the geostatistical analysis of persistent scatterer interferometry (PSI) data. PSI displacement measurements are interpolated based on conditional Sequential Gaussian Simulation (SGS) to calculate multiple equiprobable realizations of subsidence. The result from this process is a series of interpolated subsidence values, with an estimation of the spatial variability and a confidence level on the interpolation. These maps complement the PSI displacement map, improving the identification of wide subsiding areas at a regional scale. At a local scale, they can be used to identify buildings susceptible to suffer subsidence related damages. In order to do so, it is necessary to calculate the maximum differential settlement and the maximum angular distortion for each building of the study area. Based on PSI-derived parameters those buildings in which the serviceability limit state has been exceeded, and where in situ forensic analysis should be made, can be automatically identified. This methodology has been tested in the city of Orihuela (SE Spain) for the study of historical buildings damaged during the last two decades by subsidence due to aquifer overexploitation. The qualitative evaluation of the results from the methodology carried out in buildings where damages have been reported shows a success rate of 100%.

  13. Study of information extraction method of water body based on Mapping satellite-1 imagery

    NASA Astrophysics Data System (ADS)

    Zhang, Zhaoxi; Hu, Zhuowei; Du, Hongyue

    2014-11-01

    To find a suitable water extraction method from Mapping satellite-1 imagery in urban areas, this paper compared the results of different water extraction methods and studied the effect of building shadow on water extraction. Taken parts of Xinjiang (Beitun of Irtysh river Basin) as the study area, Mapping satellite-1 imagery as data sources, single-band threshold method, Normalized Difference Water Index (NDWI), Normalized Difference Vegetation Index (NDVI), and spectral relationship method based on spectral area were applied respectively to extract information of water body. The results of information extraction by use of the four methods were compared to determine the optimal method for water body extraction. The results showed that, for Mapping satellite-1 imagery, single-band threshold method and spectral relationship method which based on spectral area were effective to eliminate classification errors cased by shadows from buildings, fast, easy and accurate to extract information of water body from urban areas. In addition, the spectral relationship method based on spectral area also had the character of extracting small tributary rivers.

  14. Mapping extreme rainfall in a mountainous region using geostatistical techniques: a case study in Scotland

    NASA Astrophysics Data System (ADS)

    Prudhomme, Christel; Reed, Duncan W.

    1999-10-01

    The spatial pattern of precipitation is known to be highly dependent on meteorological conditions and relief. However, the relationships between precipitation and topography in mountainous areas are not very well known, partly because of the complex topography in these regions, and partly because of the sparsity of information available to study such relationships in high elevation areas. The purpose of the investigation was to find a method of mapping extreme rainfall in the mountainous region of Scotland, which was easy to use and to understand, and which gave satisfactory results both in terms of statistical performance and consistency with meteorological mechanisms.Among the interpolation methods described in the literature, ordinary kriging and modified residual kriging have been found attractive by reason of their simplicity and ease of use. Both methods have been applied to map an index of extreme rainfall, the median of the annual maximum daily rainfall (RMED), in the mountainous region of Scotland. Rainfall records from a network of 1003 raingauges are used, covering Scotland with uneven density. A 4-parameter regression equation developed in a previous study, relating a transformed variable of RMED to topographical variables, is used in the modified residual kriging method. Comparing the relative performances of ordinary kriging and modified residual kriging shows that the use of topographical information helps to compensate for the lack of local data from which any interpolation method, such as ordinary kriging, might suffer, thus improving the final mapping.

  15. Lasting Effects of Instruction Guided by the Conflict Map: Experimental Study of Learning about the Causes of the Seasons

    ERIC Educational Resources Information Center

    Tsai, Chin-Chung; Chang, Chun-Yen

    2005-01-01

    This study was based on the framework of the "conflict map" to facilitate student conceptual learning about causes of the seasons. Instruction guided by the conflict map emphasizes not only the use of discrepant events, but also the resolution of conflict between students' alternative conceptions and scientific conceptions, using critical events…

  16. Analyzing Interactions by an IIS-Map-Based Method in Face-to-Face Collaborative Learning: An Empirical Study

    ERIC Educational Resources Information Center

    Zheng, Lanqin; Yang, Kaicheng; Huang, Ronghuai

    2012-01-01

    This study proposes a new method named the IIS-map-based method for analyzing interactions in face-to-face collaborative learning settings. This analysis method is conducted in three steps: firstly, drawing an initial IIS-map according to collaborative tasks; secondly, coding and segmenting information flows into information items of IIS; thirdly,…

  17. A Study to Determine the Contribution Made by Concept Maps to a Computer Architecture and Organization Course

    ERIC Educational Resources Information Center

    Aydogan, Tuncay; Ergun, Serap

    2016-01-01

    Concept mapping is a method of graphical learning that can be beneficial as a study method for concept linking and organization. Concept maps, which provide an elegant, easily understood representation of an expert's domain knowledge, are tools for organizing and representing knowledge. These tools have been used in educational environments to…

  18. A Study of the Effects of Cognitive Mapping on Reading Comprehension and Written Protocols. Technical Report No. 7.

    ERIC Educational Resources Information Center

    Ruddell, Robert; Boyle, Owen

    A study explored how cognitive mapping assists college students in gathering information from long prose passages and organizing this information for subsequent writing. Mapping is a prewriting technique in which students develop a cognitive scheme or graphic representation of a text, which reduces memory load and facilitates integration and…

  19. Advanced Ecosystem Mapping Techniques for Large Arctic Study Domains Using Calibrated High-Resolution Imagery

    NASA Astrophysics Data System (ADS)

    Macander, M. J.; Frost, G. V., Jr.

    2015-12-01

    Regional-scale mapping of vegetation and other ecosystem properties has traditionally relied on medium-resolution remote sensing such as Landsat (30 m) and MODIS (250 m). Yet, the burgeoning availability of high-resolution (<=2 m) imagery and ongoing advances in computing power and analysis tools raises the prospect of performing ecosystem mapping at fine spatial scales over large study domains. Here we demonstrate cutting-edge mapping approaches over a ~35,000 km² study area on Alaska's North Slope using calibrated and atmospherically-corrected mosaics of high-resolution WorldView-2 and GeoEye-1 imagery: (1) an a priori spectral approach incorporating the Satellite Imagery Automatic Mapper (SIAM) algorithms; (2) image segmentation techniques; and (3) texture metrics. The SIAM spectral approach classifies radiometrically-calibrated imagery to general vegetation density categories and non-vegetated classes. The SIAM classes were developed globally and their applicability in arctic tundra environments has not been previously evaluated. Image segmentation, or object-based image analysis, automatically partitions high-resolution imagery into homogeneous image regions that can then be analyzed based on spectral, textural, and contextual information. We applied eCognition software to delineate waterbodies and vegetation classes, in combination with other techniques. Texture metrics were evaluated to determine the feasibility of using high-resolution imagery to algorithmically characterize periglacial surface forms (e.g., ice-wedge polygons), which are an important physical characteristic of permafrost-dominated regions but which cannot be distinguished by medium-resolution remote sensing. These advanced mapping techniques provide products which can provide essential information supporting a broad range of ecosystem science and land-use planning applications in northern Alaska and elsewhere in the circumpolar Arctic.

  20. Concept Mapping: A Unique Means for Negotiating Meaning in Professional Studies

    ERIC Educational Resources Information Center

    Mackinnon, Gregory R.; Keppell, Mike

    2005-01-01

    Concept mapping (Novak & Gowin, 1984) has been used extensively as a graphic organiser in classroom teaching. This article addresses two particular approaches to using concept mapping that go beyond classroom planning into the realm of "idea-exchange" with concept mapping as mediator. The notion of "negotiative concept mapping" is examined in two…

  1. Effect of expansive admixtures on the shrinkage and mechanical properties of high-performance fiber-reinforced cement composites.

    PubMed

    Choi, Won-Chang; Yun, Hyun-Do

    2013-01-01

    High-performance fiber-reinforced cement composites (HPFRCCs) are characterized by strain-hardening and multiple cracking during the inelastic deformation process, but they also develop high shrinkage strain. This study investigates the effects of replacing Portland cement with calcium sulfoaluminate-based expansive admixtures (CSA EXAs) to compensate for the shrinkage and associated mechanical behavior of HPFRCCs. Two types of CSA EXA (CSA-K and CSA-J), each with a different chemical composition, are used in this study. Various replacement ratios (0%, 8%, 10%, 12%, and 14% by weight of cement) of CSA EXA are considered for the design of HPFRCC mixtures reinforced with 1.5% polyethylene (PE) fibers by volume. Mechanical properties, such as shrinkage compensation, compressive strength, flexural strength, and direct tensile strength, of the HPFRCC mixtures are examined. Also, crack width and development are investigated to determine the effects of the EXAs on the performance of the HPFRCC mixtures, and a performance index is used to quantify the performance of mixture. The results indicate that replacements of 10% CSA-K (Type 1) and 8% CSA-J (Type 2) considerably enhance the mechanical properties and reduce shrinkage of HPFRCCs. PMID:24376382

  2. Effect of Expansive Admixtures on the Shrinkage and Mechanical Properties of High-Performance Fiber-Reinforced Cement Composites

    PubMed Central

    Choi, Won-Chang; Yun, Hyun-Do

    2013-01-01

    High-performance fiber-reinforced cement composites (HPFRCCs) are characterized by strain-hardening and multiple cracking during the inelastic deformation process, but they also develop high shrinkage strain. This study investigates the effects of replacing Portland cement with calcium sulfoaluminate-based expansive admixtures (CSA EXAs) to compensate for the shrinkage and associated mechanical behavior of HPFRCCs. Two types of CSA EXA (CSA-K and CSA-J), each with a different chemical composition, are used in this study. Various replacement ratios (0%, 8%, 10%, 12%, and 14% by weight of cement) of CSA EXA are considered for the design of HPFRCC mixtures reinforced with 1.5% polyethylene (PE) fibers by volume. Mechanical properties, such as shrinkage compensation, compressive strength, flexural strength, and direct tensile strength, of the HPFRCC mixtures are examined. Also, crack width and development are investigated to determine the effects of the EXAs on the performance of the HPFRCC mixtures, and a performance index is used to quantify the performance of mixture. The results indicate that replacements of 10% CSA-K (Type 1) and 8% CSA-J (Type 2) considerably enhance the mechanical properties and reduce shrinkage of HPFRCCs. PMID:24376382

  3. In the name of the migrant father—Analysis of surname origins identifies genetic admixture events undetectable from genealogical records

    PubMed Central

    Larmuseau, M H D; Vanoverbeke, J; Gielis, G; Vanderheyden, N; Larmuseau, H F M; Decorte, R

    2012-01-01

    Patrilineal heritable surnames are widely used to select autochthonous participants for studies on small-scale population genetic patterns owing to the unique link between the surname and a genetic marker, the Y-chromosome (Y-chr). Today, the question arises as to whether the surname origin will be informative on top of in-depth genealogical pedigrees. Admixture events that happened in the period after giving heritable surnames but before the start of genealogical records may be informative about the additional value of the surname origin. In this context, an interesting historical event is the demic migration from French-speaking regions in Northern France to the depopulated and Dutch-speaking region Flanders at the end of the sixteenth century. Y-chr subhaplogroups of individuals with a French/Roman surname that could be associated with this migration event were compared with those of a group with autochthonous Flemish surnames. Although these groups could not be differentiated based on in-depth genealogical data, they were significantly genetically different from each other. Moreover, the observed genetic divergence was related to the differences in the distributions of main Y-subhaplogroups between contemporary populations from Northern France and Flanders. Therefore, these results indicate that the surname origin can be an important feature on top of in-depth genealogical results to select autochthonous participants for a regional population genetic study based on Y-chromosomes. PMID:22511074

  4. Order of magnitude enhancement in neutron emission with deuterium-krypton admixture operation in miniature plasma focus device

    SciTech Connect

    Verma, Rishi; Lee, P.; Lee, S.; Springham, S. V.; Tan, T. L.; Rawat, R. S.; Krishnan, M.

    2008-09-08

    The effect of varied concentrations of deuterium-krypton (D{sub 2}-Kr) admixture on the neutron emission of a fast miniature plasma focus device was investigated. It was found that a judicious concentration of Kr in D{sub 2} can significantly enhance the neutron yield. The maximum average neutron yield of (1{+-}0.27)x10{sup 4} n/shot for pure D{sub 2} filling at 3 mbars was enhanced to (3.14{+-}0.4)x10{sup 5} n/shot with D{sub 2}+2% Kr admixture operation, which represents a >30-fold increase. More than an order of magnitude enhancement in the average neutron yield was observed over the broader operating range of 1-4 mbars for D{sub 2}+2% Kr and D{sub 2}+5% Kr admixtures.

  5. Mapping Soil Surface Macropores Using Infrared Thermography: An Exploratory Laboratory Study

    PubMed Central

    de Lima, João L. M. P.; Abrantes, João R. C. B.; Silva, Valdemir P.; de Lima, M. Isabel P.; Montenegro, Abelardo A. A.

    2014-01-01

    Macropores and water flow in soils and substrates are complex and are related to topics like preferential flow, nonequilibrium flow, and dual-continuum. Hence, the quantification of the number of macropores and the determination of their geometry are expected to provide a better understanding on the effects of pores on the soil's physical and hydraulic properties. This exploratory study aimed at evaluating the potential of using infrared thermography for mapping macroporosity at the soil surface and estimating the number and size of such macropores. The presented technique was applied to a small scale study (laboratory soil flume). PMID:25371915

  6. A plastic scintillator-based 2D thermal neutron mapping system for use in BNCT studies.

    PubMed

    Ghal-Eh, N; Green, S

    2016-06-01

    In this study, a scintillator-based measurement instrument is proposed which is capable of measuring a two-dimensional map of thermal neutrons within a phantom based on the detection of 2.22MeV gamma rays generated via nth+H→D+γ reaction. The proposed instrument locates around a small rectangular water phantom (14cm×15cm×20cm) used in Birmingham BNCT facility. The whole system has been simulated using MCNPX 2.6. The results confirm that the thermal flux peaks somewhere between 2cm and 4cm distance from the system entrance which is in agreement with previous studies. PMID:26986813

  7. Snow hydrology studies using data from the Heat Capacity Mapping Mission

    NASA Technical Reports Server (NTRS)

    Barnes, J. C.; Bowley, C. J.

    1981-01-01

    This paper describes a study of the snow hydrology application of thermal infrared (IR) data from the Heat Capacity Mapping Mission (HCMM) satellite. The HCMM data in both imagery and digital tape formats are analyzed for two study areas: the Salt-Verde Watershed in central Arizona and the southern Sierra Nevada in California. The analysis procedures are described, including the development of a unique contour plotting program that makes it possible to overlay HCMM thermal contours directly onto the visible channel imagery. The results indicate that satellite thermal-IR data can provide the hydrologist with additional useful information on snow cover.

  8. Comprehensive personal RF-EMF exposure map and its potential use in epidemiological studies.

    PubMed

    Gonzalez-Rubio, Jesus; Najera, Alberto; Arribas, Enrique

    2016-08-01

    In recent years, numerous epidemiological studies, which deal with the potential effects of mobile phone antennas on health, have almost exclusively focused on their distance to mobile phone base stations. Although it is known that this is not the best approach to the problem, this situation occurs due to the numerous difficulties when determining the personal exposure to the radiofrequency electromagnetic fields (RF-EMF). However, due to the rise of personal exposimeters, the evolution of spatial statistics, the development of geographical information systems and the use of powerful software, new alternatives are available to deal with these epidemiological studies and thus overcome the aforementioned difficulties. Using these tools, this paper presents a lattice map of personal RF-EMF exposure from exterior mobile phone base stations, covering the entire 110 administrative regions in the city of Albacete (Spain). For this purpose, we used a personal exposimeter, Satimo EME Spy 140 model, performing measurements every 4s The exposimeter was located inside the plastic basket of a bicycle, whose versatility permitted the access to all the zones of the city. Once the exposure map was prepared, its relation with the known antenna locations was studied. The 64 mobile telephone antennas of the city were also georeferenced; the randomness of both variables (exposure and antennas) were studied by means of the Moran's I test. Results showed that the distribution of the antennas follows a grouped pattern (p<0.001), while the distribution of the average exposure values have a random distribution (p=0.618). In addition, we showed two Spearman correlation studies: the first between the average exposure values and the number of mobile telephone antennas per administrative region, and the second, also considering the antennas of the neighbouring regions. No substantial correlation was detected in either of the two cases. This study also reveals the weaknesses of the

  9. A study of kindergarten children's spatial representation in a mapping project

    NASA Astrophysics Data System (ADS)

    Davis, Genevieve A.; Hyun, Eunsook

    2005-02-01

    This phenomenological study examined kindergarten children's development of spatial representation in a year long mapping project. Findings and discussion relative to how children conceptualised and represented physical space are presented in light of theoretical notions advanced by Piaget, van Hiele, and cognitive science researchers Battista and Clements. Analyses of the processes the children used and their finished products indicate that children can negotiate meaning for complex systems of geometric concepts when given opportunities to debate, negotiate, reflect, evaluate and seek meaning for representing space. The complexity and "holistic" nature of spatial representation of young children emerged in this study.

  10. Mineral classification map using MF and SAM techniques: A case study in the Nohwa Island, Korea

    SciTech Connect

    Son, Young-Sun; Yoon, Wang-Jung

    2015-03-10

    The purpose of this study is to map pyprophyllite distribution at surface of the Nohwa deposit, Korea by using Advanced Spaceborne Thermal Emission and Reflectance Radiometer (ASTER) data. For this, combined Spectral Angle Mapper (SAM), and Matched Filtering (MF) technique based on mathematical algorithm was applied. The regional distribution of high-grade and low-grade pyrophyllite in the Nohwa deposit area could be differentiated by this method. The results of this study show that ASTER data analysis using combination of SAM and MF techniques will assist in exploration of pyrophyllite at the exposed surface.

  11. D Mapping of Cultural Heritage: Special Problems and best Practices in Extreme Case-Studies

    NASA Astrophysics Data System (ADS)

    Patias, P.; Kaimaris, D.; Georgiadis, Ch.; Stamnas, A.; Antoniadis, D.; Papadimitrakis, D.

    2013-07-01

    Photogrammetrey has a long successful history in the area of 3D modelling and documentation of cultural heritage monuments. In some cases an extensive study, preparation and the application of novel solutions is required for the successful documentation and 3D modelling of monuments. In most of the cases the problem that we have to face is difficulties regarding accessing, photographing, and measuring the monument from the optimal distance, in combination with the need for a high spatial resolution mapping. This paper is highlighting the special problems and the novel solutions, performed during mapping of two significant cultural heritage monuments in Greece. The Roussanou monastery (1527-1529 A.C., Meteora, Center Greece) and its underlying rock, had to be photographed and measured from a far distance and measured with various spatial resolutions. In the lakeside Neolithic settlement of Dispilio (6.000 B.C., western Greece) the enclosure which is covered with vegetation above a height of 3 m, had to be measured with high spatial resolution. The combined use of a laser scanner, a digital camera equipped with a telephoto lens and UAV allowed the successful mapping and the production of orthophotomaps in each case.

  12. Improving the performance of digital soil maps by the application of remotely sensed data used in terroir mapping - case study of the Tokaj wine region

    NASA Astrophysics Data System (ADS)

    Takács, Katalin; Laborczi, Annamária; Lukácsy, György; Pásztor, László

    2015-04-01

    The aim of the soil mapping is to explore and visualize the spatial extension and variability of the thematic knowledge about soils. Soil maps are thematic maps, which can present information about the primary or derivative soil characteristics, soil classes and knowledge about the processes, function and services of the soils. The method for information obtaining about soils is sampling which results only point data and should be spatially extended by a properly chosen process. The digital soil mapping (DSM) method uses environmental auxiliary variables for the spatial extension. These variables should be in direct or indirect relation with the target soil characteristic and should provide full coverage for the target area. Environmental variables can be derived from digital elevation models, land cover data or satellite images which can be obtained most efficiently with remote sensing methods. The soil-landscape relation can be modelled by geostatistical and data mining methods based the soil data and auxiliary variables. The study area is Tokaj wine region (approximately 400 km2) which is located in Northeast-Hungary, in Tokaj Mountains. Soil data is available for 200 sampling points. The terrain variables - such as elevation, slope, aspect and other derivatives - are derived from a relatively high resolution digital elevation model (DEM; 1 m), that was generated by LiDAR. The other environmental variables - such as land cover, NDVI - are prepared based on Landsat images which are acquired at different seasons in line with vegetation phenology and soil coverage. The target maps are prepared by digital soil mapping methods. For the analysis of the relationship between soil sampling data and the auxiliary variables different geostatistical methods are used to choose the most appropriate environmental variables for the spatial modelling. The spatial extension of point data are performed by interpolation methods. For summarizing the main aim of this study is to test

  13. Legacy of mutiny on the Bounty: founder effect and admixture on Norfolk Island

    PubMed Central

    Macgregor, Stuart; Bellis, Claire; Lea, Rod A; Cox, Hannah; Dyer, Tom; Blangero, John; Visscher, Peter M; Griffiths, Lyn R

    2010-01-01

    The population of Norfolk Island, located off the eastern coast of Australia, possesses an unusual and fascinating history. Most present-day islanders are related to a small number of the ‘Bounty' mutineer founders. These founders consisted of Caucasian males and Polynesian females and led to an admixed present-day population. By examining a single large pedigree of 5742 individuals, spanning >200 years, we analyzed the influence of admixture and founder effect on various cardiovascular disease (CVD)-related traits. On account of the relative isolation of the population, on average one-third of the genomes of present-day islanders (single large pedigree individuals) is derived from 17 initial founders. The proportion of Polynesian ancestry in the present-day individuals was found to significantly influence total triglycerides, body mass index, systolic blood pressure and diastolic blood pressure. For various cholesterol traits, the influence of ancestry was less marked but overall the direction of effect for all CVD-related traits was consistent with Polynesian ancestry conferring greater CVD risk. Marker-derived homozygosity was computed and agreed with measures of inbreeding derived from pedigree information. Founder effect (inbreeding and marker-derived homozygosity) significantly influenced height. In conclusion, both founder effect and extreme admixture have substantially influenced the genetic architecture of a variety of CVD-related traits in this population. PMID:19584896

  14. Denisova admixture and the first modern human dispersals into Southeast Asia and Oceania.

    PubMed

    Reich, David; Patterson, Nick; Kircher, Martin; Delfin, Frederick; Nandineni, Madhusudan R; Pugach, Irina; Ko, Albert Min-Shan; Ko, Ying-Chin; Jinam, Timothy A; Phipps, Maude E; Saitou, Naruya; Wollstein, Andreas; Kayser, Manfred; Pääbo, Svante; Stoneking, Mark

    2011-10-01

    It has recently been shown that ancestors of New Guineans and Bougainville Islanders have inherited a proportion of their ancestry from Denisovans, an archaic hominin group from Siberia. However, only a sparse sampling of populations from Southeast Asia and Oceania were analyzed. Here, we quantify Denisova admixture in 33 additional populations from Asia and Oceania. Aboriginal Australians, Near Oceanians, Polynesians, Fijians, east Indonesians, and Mamanwa (a "Negrito" group from the Philippines) have all inherited genetic material from Denisovans, but mainland East Asians, western Indonesians, Jehai (a Negrito group from Malaysia), and Onge (a Negrito group from the Andaman Islands) have not. These results indicate that Denisova gene flow occurred into the common ancestors of New Guineans, Australians, and Mamanwa but not into the ancestors of the Jehai and Onge and suggest that relatives of present-day East Asians were not in Southeast Asia when the Denisova gene flow occurred. Our finding that descendants of the earliest inhabitants of Southeast Asia do not all harbor Denisova admixture is inconsistent with a history in which the Denisova interbreeding occurred in mainland Asia and then spread over Southeast Asia, leading to all its earliest modern human inhabitants. Instead, the data can be most parsimoniously explained if the Denisova gene flow occurred in Southeast Asia itself. Thus, archaic Denisovans must have lived over an extraordinarily broad geographic and ecological range, from Siberia to tropical Asia. PMID:21944045

  15. Genetic origin, admixture, and asymmetry in maternal and paternal human lineages in Cuba

    PubMed Central

    2008-01-01

    Background Before the arrival of Europeans to Cuba, the island was inhabited by two Native American groups, the Tainos and the Ciboneys. Most of the present archaeological, linguistic and ancient DNA evidence indicates a South American origin for these populations. In colonial times, Cuban Native American people were replaced by European settlers and slaves from Africa. It is still unknown however, to what extent their genetic pool intermingled with and was 'diluted' by the arrival of newcomers. In order to investigate the demographic processes that gave rise to the current Cuban population, we analyzed the hypervariable region I (HVS-I) and five single nucleotide polymorphisms (SNPs) in the mitochondrial DNA (mtDNA) coding region in 245 individuals, and 40 Y-chromosome SNPs in 132 male individuals. Results The Native American contribution to present-day Cubans accounted for 33% of the maternal lineages, whereas Africa and Eurasia contributed 45% and 22% of the lineages, respectively. This Native American substrate in Cuba cannot be traced back to a single origin within the American continent, as previously suggested by ancient DNA analyses. Strikingly, no Native American lineages were found for the Y-chromosome, for which the Eurasian and African contributions were around 80% and 20%, respectively. Conclusion While the ancestral Native American substrate is still appreciable in the maternal lineages, the extensive process of population admixture in Cuba has left no trace of the paternal Native American lineages, mirroring the strong sexual bias in the admixture processes taking place during colonial times. PMID:18644108

  16. Denisova Admixture and the First Modern Human Dispersals into Southeast Asia and Oceania

    PubMed Central

    Reich, David; Patterson, Nick; Kircher, Martin; Delfin, Frederick; Nandineni, Madhusudan R.; Pugach, Irina; Ko, Albert Min-Shan; Ko, Ying-Chin; Jinam, Timothy A.; Phipps, Maude E.; Saitou, Naruya; Wollstein, Andreas; Kayser, Manfred; Pääbo, Svante; Stoneking, Mark

    2011-01-01

    It has recently been shown that ancestors of New Guineans and Bougainville Islanders have inherited a proportion of their ancestry from Denisovans, an archaic hominin group from Siberia. However, only a sparse sampling of populations from Southeast Asia and Oceania were analyzed. Here, we quantify Denisova admixture in 33 additional populations from Asia and Oceania. Aboriginal Australians, Near Oceanians, Polynesians, Fijians, east Indonesians, and Mamanwa (a “Negrito” group from the Philippines) have all inherited genetic material from Denisovans, but mainland East Asians, western Indonesians, Jehai (a Negrito group from Malaysia), and Onge (a Negrito group from the Andaman Islands) have not. These results indicate that Denisova gene flow occurred into the common ancestors of New Guineans, Australians, and Mamanwa but not into the ancestors of the Jehai and Onge and suggest that relatives of present-day East Asians were not in Southeast Asia when the Denisova gene flow occurred. Our finding that descendants of the earliest inhabitants of Southeast Asia do not all harbor Denisova admixture is inconsistent with a history in which the Denisova interbreeding occurred in mainland Asia and then spread over Southeast Asia, leading to all its earliest modern human inhabitants. Instead, the data can be most parsimoniously explained if the Denisova gene flow occurred in Southeast Asia itself. Thus, archaic Denisovans must have lived over an extraordinarily broad geographic and ecological range, from Siberia to tropical Asia. PMID:21944045

  17. Genetic admixture history of Eastern Indonesia as revealed by Y-chromosome and mitochondrial DNA analysis.

    PubMed

    Mona, Stefano; Grunz, Katharina E; Brauer, Silke; Pakendorf, Brigitte; Castrì, Loredana; Sudoyo, Herawati; Marzuki, Sangkot; Barnes, Robert H; Schmidtke, Jörg; Stoneking, Mark; Kayser, Manfred

    2009-08-01

    Eastern Indonesia possesses more linguistic diversity than any other region in Southeast Asia, with both Austronesian (AN) languages that are of East Asian origin, as well as non-Austronesian (NAN) languages of likely Melanesian origin. Here, we investigated the genetic history of human populations from seven eastern Indonesian islands, including AN and NAN speakers, as well as the relationship between languages and genes, by means of nonrecombining Y-chromosomal (NRY) and mitochondrial DNA (mtDNA) analysis. We found that the eastern Indonesian gene pool consists of East Asian as well as Melanesian components, as might be expected based on linguistic evidence, but also harbors putative indigenous eastern Indonesian signatures that perhaps reflect the initial occupation of the Wallacea by aboriginal hunter-gatherers already in Palaeolithic times. Furthermore, both NRY and mtDNA data showed a complete lack of correlation between linguistic and genetic relationships, most likely reflecting genetic admixture and/or language shift. In addition, we noted a small fraction of the NRY and mtDNA data shared between eastern Indonesians and Australian Aborigines likely reflecting an ancient link between Asia and Australia. Our data thus provide insights into the complex genetic ancestry history of eastern Indonesian islanders characterized by several admixture episodes and demonstrate a clear example of the lack of the often-assumed correlation between the genes and languages of human populations. PMID:19414523

  18. Regional mapping of forest canopy water content and biomass using AIRSAR images over BOREAS study area

    NASA Technical Reports Server (NTRS)

    Saatchi, Sasan; Rignot, Eric; Vanzyl, Jakob

    1995-01-01

    In recent years, monitoring vegetation biomass over various climate zones has become the primary focus of several studies interested in assessing the role of the ecosystem responses to climate change and human activities. Airborne and spaceborne Synthetic Aperture Radar (SAR) systems provide a useful tool to directly estimate biomass due to its sensitivity to structural and moisture characteristics of vegetation canopies. Even though the sensitivity of SAR data to total aboveground biomass has been successfully demonstrated in many controlled experiments over boreal forests and forest plantations, so far, no biomass estimation algorithm has been developed. This is mainly due to the fact that the SAR data, even at lowest frequency (P-band) saturates at biomass levels of about 200 tons/ha, and the structure and moisture information in the SAR signal forces the estimation algorithm to be forest type dependent. In this paper, we discuss the development of a hybrid forest biomass algorithm which uses a SAR derived land cover map in conjunction with a forest backscatter model and an inversion algorithm to estimate forest canopy water content. It is shown that unlike the direct biomass estimation from SAR data, the estimation of water content does not depend on the seasonal and/or environmental conditions. The total aboveground biomass can then be derived from canopy water content for each type of forest by incorporating other ecological information. Preliminary results from this technique over several boreal forest stands indicate that (1) the forest biomass can be estimated with reasonable accuracy, and (2) the saturation level of the SAR signal can be enhanced by separating the crown and trunk biomass in the inversion algorithm. We have used the JPL AIRSAR data over BOREAS southern study area to test the algorithm and to generate regional scale water content and biomass maps. The results are compared with ground data and the sources of errors are discussed. Several SAR

  19. Experimental Investigation of Droplet Evaporation of Water with Ground Admixtures while Motion in a Flame of Liquid Fuel

    NASA Astrophysics Data System (ADS)

    Dmitriyenko, Margarita A.; Nyashina, Galina S.; Zhdanova, Alena O.; Vysokomornaya, Olga V.

    2016-02-01

    The evaporation features for the atomized flow of suspension on the base of water with ground admixtures in an area of high-temperature combustion products of liquid flammable substance (acetone) were investigated experimentally by the optical methods of gas flow diagnostic and the high-speed video recording. The scales of influence of clay and silt concentration in droplets of atomized flow on the intensity of its evaporation were determined. The approximation dependences describing a decrease in typical size of suspension droplets at various values of ground admixtures were obtained.

  20. LETTER TO THE EDITOR: Mirror-matter admixtures in Ω- two-body non-leptonic decays and the |ΔI| = 1/2 rule

    NASA Astrophysics Data System (ADS)

    Sánchez-Colón, G.; Huerta, R.; García, A.

    2003-03-01

    We extend our previous analysis of mirror-matter admixtures to reproduce the |DeltaI| = 1/2 rule predictions in the decays Omega- rightarrow Xi-pi0, Omega- rightarrow Xi0pi- and Omega- rightarrow LambdaK-. The results are satisfactory, lending credibility to the possibility that the enhancement phenomenon may be attributed to such admixtures.

  1. Landslide hazard mapping with selected dominant factors: A study case of Penang Island, Malaysia

    NASA Astrophysics Data System (ADS)

    Tay, Lea Tien; Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum; Lateh, Habibah

    2015-05-01

    Landslide is one of the destructive natural geohazards in Malaysia. In addition to rainfall as triggering factos for landslide in Malaysia, topographical and geological factors play important role in the landslide susceptibility analysis. Conventional topographic factors such as elevation, slope angle, slope aspect, plan curvature and profile curvature have been considered as landslide causative factors in many research works. However, other topographic factors such as diagonal length, surface area, surface roughness and rugosity have not been considered, especially for the research work in landslide hazard analysis in Malaysia. This paper presents landslide hazard mapping using Frequency Ratio (FR) and the study area is Penang Island of Malaysia. Frequency ratio approach is a variant of probabilistic method that is based on the observed relationships between the distribution of landslides and each landslide-causative factor. Landslide hazard map of Penang Island is produced by considering twenty-two (22) landslide causative factors. Among these twenty-two (22) factors, fourteen (14) factors are topographic factors. They are elevation, slope gradient, slope aspect, plan curvature, profile curvature, general curvature, tangential curvature, longitudinal curvature, cross section curvature, total curvature, diagonal length, surface area, surface roughness and rugosity. These topographic factors are extracted from the digital elevation model of Penang Island. The other eight (8) non-topographic factors considered are land cover, vegetation cover, distance from road, distance from stream, distance from fault line, geology, soil texture and rainfall precipitation. After considering all twenty-two factors for landslide hazard mapping, the analysis is repeated with fourteen dominant factors which are selected from the twenty-two factors. Landslide hazard map was segregated into four categories of risks, i.e. Highly hazardous area, Hazardous area, Moderately hazardous area

  2. Methodology for Elaborating Regional Susceptibility Maps of Slope Instability: the State of Guerrero (mexico) Case Study

    NASA Astrophysics Data System (ADS)

    González Huesca, A. E.; Ferrés, D.; Domínguez-M, L.

    2013-05-01

    Numerous cases of different types of slope instability occur every year in the mountain areas of México. Sometimes these instabilities severely affect the exposed communities, roads and infrastructure, causing deaths and serious material damage, mainly in the states of Puebla, Veracruz, Oaxaca, Guerrero and Chiapas, at the central and south sectors of the country. The occurrence of the slope instability is the result of the combination of climatic, geologic, hydrologic, geomorphologic and anthropogenic factors. The National Center for Disaster Prevention (CENAPRED) is developing several projects in order to offer civil protection authorities of the Mexican states some methodologies to address the hazard assessment for different natural phenomena in a regional level. In this framework, during the past two years, a methodology was prepared to construct susceptibility maps for slope instability at regional (≤ 1:100 000) and national (≤ 1:1 000 000) levels. This research was addressed in accordance to the criteria established by the International Association of Engineering Geology, which is the highest international authority in this topic. The state of Guerrero has been taken as a pilot scheme to elaborate the susceptibility map for slope instability at a regional level. The major constraints considered in the methodology to calculate susceptibility are: a) the slope of the surface, b) the geology and c) the land use, which were integrated using a Geographic Information System (GIS). The arithmetic sum and weighting factors to obtain the final susceptibility map were based on the average values calculated in the individual study of several cases of slope instability occurred in the state in the past decade. For each case, the evaluation format proposed by CENAPRED in 2006 in the "Guía Básica para la elaboración de Atlas Estatales y Municipales de Peligros y Riesgos" to evaluate instabilities in a local level, was applied. The resulting susceptibility map shows

  3. Landslide hazard mapping with selected dominant factors: A study case of Penang Island, Malaysia

    SciTech Connect

    Tay, Lea Tien; Alkhasawneh, Mutasem Sh.; Ngah, Umi Kalthum; Lateh, Habibah

    2015-05-15

    Landslide is one of the destructive natural geohazards in Malaysia. In addition to rainfall as triggering factos for landslide in Malaysia, topographical and geological factors play important role in the landslide susceptibility analysis. Conventional topographic factors such as elevation, slope angle, slope aspect, plan curvature and profile curvature have been considered as landslide causative factors in many research works. However, other topographic factors such as diagonal length, surface area, surface roughness and rugosity have not been considered, especially for the research work in landslide hazard analysis in Malaysia. This paper presents landslide hazard mapping using Frequency Ratio (FR) and the study area is Penang Island of Malaysia. Frequency ratio approach is a variant of probabilistic method that is based on the observed relationships between the distribution of landslides and each landslide-causative factor. Landslide hazard map of Penang Island is produced by considering twenty-two (22) landslide causative factors. Among these twenty-two (22) factors, fourteen (14) factors are topographic factors. They are elevation, slope gradient, slope aspect, plan curvature, profile curvature, general curvature, tangential curvature, longitudinal curvature, cross section curvature, total curvature, diagonal length, surface area, surface roughness and rugosity. These topographic factors are extracted from the digital elevation model of Penang Island. The other eight (8) non-topographic factors considered are land cover, vegetation cover, distance from road, distance from stream, distance from fault line, geology, soil texture and rainfall precipitation. After considering all twenty-two factors for landslide hazard mapping, the analysis is repeated with fourteen dominant factors which are selected from the twenty-two factors. Landslide hazard map was segregated into four categories of risks, i.e. Highly hazardous area, Hazardous area, Moderately hazardous area

  4. Cloud mapping in the upper Jupiter troposphere from JIRAM/Juno data: preliminary sensitivity study

    NASA Astrophysics Data System (ADS)

    Grassi, D.; Adriani, A.; Mura, A.

    2013-09-01

    The Jupiter InfraRed Auroral Mapper (JIRAM) on board of the Juno spacecraft is a spectro-imager operating in the 2-5 μm range with a spectral resolution of 9 nm. Grassi et al. [1] provided a quantitative assessment of the retrieval capabilities of the instrument in measuring mixing ratios of minor species in hot-spot conditions. The present study extends the previous investigations focusing on the aerosol retrieval capabilities in a variety of conditions, including daytime measurements. Namely, we confirm that JIRAM data at 2 μm can effectively map clouds opacities in the lower stratosphere (p < 500 mbar).

  5. Optimization of process parameters for the manufacturing of rocket casings: A study using processing maps

    NASA Astrophysics Data System (ADS)

    Avadhani, G. S.

    2003-12-01

    Maraging steels possess ultrahigh strength combined with ductility and toughness and could be easily fabricated and heat-treated. Bulk metalworking of maraging steels is an important step in the component manufacture. To optimize the hot-working parameters (temperature and strain rate) for the ring rolling process of maraging steel used for the manufacture of rocket casings, a systematic study was conducted to characterize the hot working behavior by developing processing maps for γ-iron and an indigenous 250 grade maraging steel. The hot deformation behavior of binary alloys of iron with Ni, Co, and Mo, which are major constituents of maraging steel, is also studied. Results from the investigation suggest that all the materials tested exhibit a domain of dynamic recrystallization (DRX). From the instability maps, it was revealed that strain rates above 10 s-1 are not suitable for hot working of these materials. An important result from the stress-strain behavior is that while Co strengthens γ-iron, Ni and Mo cause flow softening. Temperatures around 1125 °C and strain rate range between 0.001 and 0.1 s-1 are suitable for the hot working of maraging steel in the DRX domain. Also, higher strain rates may be used in the meta-dynamic recrystallization domain above 1075 °C for high strain rate applications such as ring rolling. The microstructural mechanisms identified from the processing maps along with grain size analyses and hot ductility measurements could be used to design hot-working schedules for maraging steel.

  6. Forgotten forests - issues and prospects in biome mapping using Seasonally Dry Tropical Forests as a case study

    PubMed Central

    2011-01-01

    Background South America is one of the most species diverse continents in the world. Within South America diversity is not distributed evenly at both local and continental scales and this has led to the recognition of various areas with unique species assemblages. Several schemes currently exist which divide the continental-level diversity into large species assemblages referred to as biomes. Here we review five currently available biome maps for South America, including the WWF Ecoregions, the Americas basemap, the Land Cover Map of South America, Morrone's Biogeographic regions of Latin America, and the Ecological Systems Map. The comparison is performed through a case study on the Seasonally Dry Tropical Forest (SDTF) biome using herbarium data of habitat specialist species. Results Current biome maps of South America perform poorly in depicting SDTF distribution. The poor performance of the maps can be attributed to two main factors: (1) poor spatial resolution, and (2) poor biome delimitation. Poor spatial resolution strongly limits the use of some of the maps in GIS applications, especially for areas with heterogeneous landscape such as the Andes. Whilst the Land Cover Map did not suffer from poor spatial resolution, it showed poor delimitation of biomes. The results highlight that delimiting structurally heterogeneous vegetation is difficult based on remote sensed data alone. A new refined working map of South American SDTF biome is proposed, derived using the Biome Distribution Modelling (BDM) approach where georeferenced herbarium data is used in conjunction with bioclimatic data. Conclusions Georeferenced specimen data play potentially an important role in biome mapping. Our study shows that herbarium data could be used as a way of ground-truthing biome maps in silico. The results also illustrate that herbarium data can be used to model vegetation maps through predictive modelling. The BDM approach is a promising new method in biome mapping, and could be

  7. Preliminary Geological Map of the Ac-H-1 Asari Quadrangle of Ceres: An Integrated Mapping Study Using Dawn Spacecraft Data.

    NASA Astrophysics Data System (ADS)

    Ruesch, O.; McFadden, L. A.; Hiesinger, H.; Scully, J. E. C.; Kneissl, T.; Hughson, K.; Williams, D. A.; Roatsch, T.; Preusker, F.; Schmedemann, N.; Marchi, S.; Jaumann, R.; Nathues, A.; Raymond, C. A.; Russell, C. T.

    2015-12-01

    We used geologic mapping applied to Dawn spacecraft data as a tool to understand the geologic history of the Ac-H-1 Asari quadrangle of dwarf planet Ceres. The Dawn Framing Camera observed the quadrangle (north polar area: 66°N-90°N) from an altitude of 4424 km and a clear-filter mosaic was produced at a spatial resolution of 400 m/pixel. A stereo-photogrammetric digital elevation model was calculated from images acquired during a higher altitude resulting in a spatial resolution of 1.4 km/pixel. Key characteristics of the study area are (1) a high density of impact craters and (2) moderate topographic variations. We measured a crater density of 9.8E-04 (km-2) for crater diameters >10 km, the highest on Ceres. Few isolated topographic highs (plateaus), reaching ~5 km in altitude relative to the ellipsoid, are present. Their irregular shape is often sculpted by impacts. We also note a positive relief with relatively steep slopes (~13°) and a cone-like shape centered at 85°N/8°E. Topographic lows, reaching -4 km, correspond to the floors of impact craters with diameters up to 64 km. The morphology of impact craters exhibits varying degrees of degradation. Degraded crater floors show central peaks and mass wasting deposits. The largest morphologically fresh deposit (78°N/38°E) is 20 km long, and has a lobate shape with striations on its surface. It extends from a crater rim downslope. No extensive ejecta deposits are present in the study area. In the course of the ongoing mission, we will incorporate mosaics from the High Altitude Mapping Orbit (~140 m/pixel) and Low Altitude Mapping Orbit (~35 m/pixel) phases to complete the preliminary photo-geological map and stratigraphy.

  8. Trans-ethnic genome-wide association studies: advantages and challenges of mapping in diverse populations.

    PubMed

    Li, Yun R; Keating, Brendan J

    2014-01-01

    Genome-wide association studies (GWASs) are the method most often used by geneticists to interrogate the human genome, and they provide a cost-effective way to identify the genetic variants underpinning complex traits and diseases. Most initial GWASs have focused on genetically homogeneous cohorts from European populations given the limited availability of ethnic minority samples and so as to limit population stratification effects. Transethnic studies have been invaluable in explaining the heritability of common quantitative traits, such as height, and in examining the genetic architecture of complex diseases, such as type 2 diabetes. They provide an opportunity for large-scale signal replication in independent populations and for cross-population meta-analyses to boost statistical power. In addition, transethnic GWASs enable prioritization of candidate genes, fine-mapping of functional variants, and potentially identification of SNPs associated with disease risk in admixed populations, by taking advantage of natural differences in genomic linkage disequilibrium across ethnically diverse populations. Recent efforts to assess the biological function of variants identified by GWAS have highlighted the need for large-scale replication, meta-analyses and fine-mapping across worldwide populations of ethnically diverse genetic ancestries. Here, we review recent advances and new approaches that are important to consider when performing, designing or interpreting transethnic GWASs, and we highlight existing challenges, such as the limited ability to handle heterogeneity in linkage disequilibrium across populations and limitations in dissecting complex architectures, such as those found in recently admixed populations. PMID:25473427

  9. Using MatContM in the study of a nonlinear map in economics

    NASA Astrophysics Data System (ADS)

    Neirynck, Niels; Al-Hdaibat, Bashir; Govaerts, Willy; Kuznetsov, Yuri A.; Meijer, Hil G. E.

    2016-02-01

    MatContM is a MATLAB interactive toolbox for the numerical study of iterated smooth maps, their Lyapunov exponents, fixed points, and periodic, homoclinic and heteroclinic orbits as well as their stable and unstable invariant manifolds. The bifurcation analysis is based on continuation methods, tracing out solution manifolds of various types of objects while some of the parameters of the map vary. In particular, MatContM computes codimension 1 bifurcation curves of cycles and supports the computation of the normal form coefficients of their codimension two bifurcations, and allows branch switching from codimension 2 points to secondary curves. MatContM builds on an earlier command-line MATLAB package CL MatContM but provides new computational routines and functionalities, as well as a graphical user interface, enabling interactive control of all computations, data handling and archiving. We apply MatContM in our study of the monopoly model of T. Puu with cubic price and quadratic marginal cost functions. Using MatContM, we analyze the fixed points and their stability and we compute branches of solutions of period 5, 10, 13 17. The chaotic and periodic behavior of the monopoly model is further analyzed by computing the largest Lyapunov exponents.

  10. Mapping of contaminant plumes with geoelectrical methods. A case study in urban context

    NASA Astrophysics Data System (ADS)

    Vaudelet, P.; Schmutz, M.; Pessel, M.; Franceschi, M.; Guérin, R.; Atteia, O.; Blondel, A.; Ngomseu, C.; Galaup, S.; Rejiba, F.; Bégassat, P.

    2011-12-01

    During the past two decades, the diagnosis and monitoring of polluted sites have become more important. Urban sites are particularly difficult to study, because they are contaminated with various pollutants, and there is a large physical and chemical heterogeneity. The heterogeneity comes from the landfilling of various solid wastes and remolded soil (endogenous or exogenous) from which they were constituted over time. Traditional techniques such as wells monitoring, are often insufficient to evaluate the extension of soil contamination. This is why we proposed a geoelectrical methodology from the fastest to the most information rich technique, showing all carry out and acquisition times: electromagnetic low frequency conductivity mapping, electrical resistivity profiles, chargeability profiles and spectral induced polarization (SIP) soundings. This strategy has been successfully applied to an urban site located in the Paris Basin (France). A conductivity map in relation with geochemical and lithological informations should provide us information to implement electrical resistivity and chargeability profiles. The latter allowed us to differentiate 3 main anomaly zones that have been determined. As interpretation of chargeability profiles is difficult, because it integrates polarization mechanisms with different relaxation times, we add spectral induced polarization soundings that provide us information concerning the contaminant nature. We determined the extension of an organic phase, and of 2 highly mineralized zones that could be linked to biodegraded and/or with pyrite areas. That theory is consistent with groundwater analysis and SIP data. The conclusion is that the suggested methodology is well suited to the study of urban contaminated sites including several different pollutants.

  11. Mapping longitudinal studies to risk factors in an ontology for dementia.

    PubMed

    Roantree, Mark; O' Donoghue, Jim; O' Kelly, Noel; Pierce, Maria; Irving, Kate; Van Boxtel, Martin; Köhler, Sebastian

    2016-06-01

    A common activity carried out by healthcare professionals is to test various hypotheses on longitudinal study data in an effort to develop new and more reliable algorithms that might determine the possibility of developing certain illnesses. The INnovative, Midlife INtervention for Dementia Deterrence project provides input from a number of European dementia experts to identify the most accurate model of inter-related risk factors which can yield a personalized dementia-risk quotient and profile. This model is then validated against the large population-based prospective Maastricht Aging Study dataset. As part of this overall goal, the research presented in this article demonstrates how we can automate the process of mapping modifiable risk factors against large sections of the aging study and thus use information technology to provide more powerful query interfaces. PMID:25564493

  12. AVIRIS Land-Surface Mapping in Support of the Boreal Ecosystem-Atmosphere Study (BOREAS)

    NASA Technical Reports Server (NTRS)

    Roberts, Dar A.; Gamon, John; Keightley, Keir; Prentiss, Dylan; Reith, Ernest; Green, Robert

    2001-01-01

    A key scientific objective of the original Boreal Ecosystem-Atmospheric Study (BOREAS) field campaign (1993-1996) was to obtain the baseline data required for modeling and predicting fluxes of energy, mass, and trace gases in the boreal forest biome. These data sets are necessary to determine the sensitivity of the boreal forest biome to potential climatic changes and potential biophysical feedbacks on climate. A considerable volume of remotely-sensed and supporting field data were acquired by numerous researchers to meet this objective. By design, remote sensing and modeling were considered critical components for scaling efforts, extending point measurements from flux towers and field sites over larger spatial and longer temporal scales. A major focus of the BOREAS follow-on program is concerned with integrating the diverse remotely sensed and ground-based data sets to address specific questions such as carbon dynamics at local to regional scales. The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) has the potential of contributing to BOREAS through: (1) accurate retrieved apparent surface reflectance; (2) improved landcover classification; and (3) direct assessment of biochemical/biophysical information such as canopy liquid water and chlorophyll concentration through pigment fits. In this paper, we present initial products for major flux tower sites including: (1) surface reflectance of dominant cover types; (2) a land-cover classification developed using spectral mixture analysis (SMA) and Multiple Endmember Spectral Mixture Analysis (MESMA); and (3) liquid water maps. Our goal is to compare these land-cover maps to existing maps and to incorporate AVIRIS image products into models of photosynthetic flux.

  13. Spectral density mapping at multiple magnetic fields suitable for 13C NMR relaxation studies

    NASA Astrophysics Data System (ADS)

    Kadeřávek, Pavel; Zapletal, Vojtěch; Fiala, Radovan; Srb, Pavel; Padrta, Petr; Přecechtělová, Jana Pavlíková; Šoltésová, Mária; Kowalewski, Jozef; Widmalm, Göran; Chmelík, Josef; Sklenář, Vladimír; Žídek, Lukáš

    2016-05-01

    Standard spectral density mapping protocols, well suited for the analysis of 15N relaxation rates, introduce significant systematic errors when applied to 13C relaxation data, especially if the dynamics is dominated by motions with short correlation times (small molecules, dynamic residues of macromolecules). A possibility to improve the accuracy by employing cross-correlated relaxation rates and on measurements taken at several magnetic fields has been examined. A suite of protocols for analyzing such data has been developed and their performance tested. Applicability of the proposed protocols is documented in two case studies, spectral density mapping of a uniformly labeled RNA hairpin and of a selectively labeled disaccharide exhibiting highly anisotropic tumbling. Combination of auto- and cross-correlated relaxation data acquired at three magnetic fields was applied in the former case in order to separate effects of fast motions and conformational or chemical exchange. An approach using auto-correlated relaxation rates acquired at five magnetic fields, applicable to anisotropically moving molecules, was used in the latter case. The results were compared with a more advanced analysis of data obtained by interpolation of auto-correlated relaxation rates measured at seven magnetic fields, and with the spectral density mapping of cross-correlated relaxation rates. The results showed that sufficiently accurate values of auto- and cross-correlated spectral density functions at zero and 13C frequencies can be obtained from data acquired at three magnetic fields for uniformly 13C -labeled molecules with a moderate anisotropy of the rotational diffusion tensor. Analysis of auto-correlated relaxation rates at five magnetic fields represents an alternative for molecules undergoing highly anisotropic motions.

  14. Geospatial modelling for groundwater quality mapping: a case study of Rupnagar district, Punjab, India

    NASA Astrophysics Data System (ADS)

    Sahoo, S.; Kaur, A.; Litoria, P.; Pateriya, B.

    2014-11-01

    Over period of time, the water usage and management is under stress for various reasons including pollution in both surface and subsurface. The groundwater quality decreases due to the solid waste from urban and industrial nodes, rapid use of insecticides and pesticides in agricultural practices. In this study, ground water quality maps for Rupnagar district of Punjab has been prepared using geospatial interpolation technique through Inverse Distance Weighted (IDW) approach. IDW technique has been used for major ground water quality parameters observed from the field samples like Arsenic, Hardness, pH, Iron, Fluoride, TDS, and Sulphate. To assess the ground water quality of the Rupnagar district, total 280 numbers of samples from various sources of tubewells for both pre and post monsoon have collected. Out of which, 80 to 113 samples found Iron with non potable limits ranging 0.3-1.1mg/l and 0.3-1.02mg/l according to BIS standard for both the seasons respectively. Chamkaur Sahib, Rupnagar, Morinda blocks have been found non potable limit of iron in both pre & post-monsoon. 11 to 52 samples in this region have sulphate with permissible limits in both the season ranging 200-400mg/l and 201-400mg/l. But arsenic had acceptable limit in both the season. Various parameters-wise ground water quality map is generated using the range values of drinking water quality to know the distribution of different parameters and diversification in the concentration of different elements. These maps are very much needful for human being to expand awareness among the people to maintain the Cleanness of water at their highest quality and purity levels to achieve a healthy life.

  15. Spectral density mapping at multiple magnetic fields suitable for (13)C NMR relaxation studies.

    PubMed

    Kadeřávek, Pavel; Zapletal, Vojtěch; Fiala, Radovan; Srb, Pavel; Padrta, Petr; Přecechtělová, Jana Pavlíková; Šoltésová, Mária; Kowalewski, Jozef; Widmalm, Göran; Chmelík, Josef; Sklenář, Vladimír; Žídek, Lukáš

    2016-05-01

    Standard spectral density mapping protocols, well suited for the analysis of (15)N relaxation rates, introduce significant systematic errors when applied to (13)C relaxation data, especially if the dynamics is dominated by motions with short correlation times (small molecules, dynamic residues of macromolecules). A possibility to improve the accuracy by employing cross-correlated relaxation rates and on measurements taken at several magnetic fields has been examined. A suite of protocols for analyzing such data has been developed and their performance tested. Applicability of the proposed protocols is documented in two case studies, spectral density mapping of a uniformly labeled RNA hairpin and of a selectively labeled disaccharide exhibiting highly anisotropic tumbling. Combination of auto- and cross-correlated relaxation data acquired at three magnetic fields was applied in the former case in order to separate effects of fast motions and conformational or chemical exchange. An approach using auto-correlated relaxation rates acquired at five magnetic fields, applicable to anisotropically moving molecules, was used in the latter case. The results were compared with a more advanced analysis of data obtained by interpolation of auto-correlated relaxation rates measured at seven magnetic fields, and with the spectral density mapping of cross-correlated relaxation rates. The results showed that sufficiently accurate values of auto- and cross-correlated spectral density functions at zero and (13)C frequencies can be obtained from data acquired at three magnetic fields for uniformly (13)C-labeled molecules with a moderate anisotropy of the rotational diffusion tensor. Analysis of auto-correlated relaxation rates at five magnetic fields represents an alternative for molecules undergoing highly anisotropic motions. PMID:27003380

  16. Admixture dynamics in Hispanics: A shift in the nuclear genetic ancestry of a South American population isolate

    PubMed Central

    Bedoya, Gabriel; Montoya, Patricia; García, Jenny; Soto, Ivan; Bourgeois, Stephane; Carvajal, Luis; Labuda, Damian; Alvarez, Victor; Ospina, Jorge; Hedrick, Philip W.; Ruiz-Linares, Andrés

    2006-01-01

    Although it is well established that Hispanics generally have a mixed Native American, African, and European ancestry, the dynamics of admixture at the foundation of Hispanic populations is heterogeneous and poorly documented. Genetic analyses are potentially very informative for probing the early demographic history of these populations. Here we evaluate the genetic structure and admixture dynamics of a province in northwest Colombia (Antioquia), which prior analyses indicate was founded mostly by Spanish men and native women. We examined surname, Y chromosome, and mtDNA diversity in a geographically structured sample of the region and obtained admixture estimates with highly informative autosomal and X chromosome markers. We found evidence of reduced surname diversity and support for the introduction of several common surnames by single founders, consistent with the isolation of Antioquia after the colonial period. Y chromosome and mtDNA data indicate little population substructure among founder Antioquian municipalities. Interestingly, despite a nearly complete Native American mtDNA background, Antioquia has a markedly predominant European ancestry at the autosomal and X chromosome level, which suggests that, after foundation, continuing admixture with Spanish men (but not with native women) increased the European nuclear ancestry of Antioquia. This scenario is consistent with historical information and with results from population genetics theory. PMID:16648268

  17. The International Association for the Study of Lung Cancer Lymph Node Map: A Radiologic Atlas and Review

    PubMed Central

    van Beek, Edwin JR; Murchison, John T; Marin, Aleksander; Mirsadraee, Saeed

    2015-01-01

    Accurate lymph node staging of lung cancer is crucial in determining optimal treatment plans and predicting patient outcome. Currently used lymph node maps have been reconciled to the internationally accepted International Association for the Study of Lung Cancer (IASLC) map published in the seventh edition of TNM classification system of malignant tumours. This article provides computed tomographic illustrations of the IASLC nodal map, to facilitate its application in day-to-day clinical practice in order to increase the appropriate classification in lung cancer staging. PMID:26175770

  18. Integration between ground based and satellite SAR data in landslide mapping: The San Fratello case study

    NASA Astrophysics Data System (ADS)

    Bardi, Federica; Frodella, William; Ciampalini, Andrea; Bianchini, Silvia; Del Ventisette, Chiara; Gigli, Giovanni; Fanti, Riccardo; Moretti, Sandro; Basile, Giuseppe; Casagli, Nicola

    2014-10-01

    The potential use of the integration of PSI (Persistent Scatterer Interferometry) and GB-InSAR (Ground-based Synthetic Aperture Radar Interferometry) for landslide hazard mitigation was evaluated for mapping and monitoring activities of the San Fratello landslide (Sicily, Italy). Intense and exceptional rainfall events are the main factors that triggered several slope movements in the study area, which is susceptible to landslides, because of its steep slopes and silty-clayey sedimentary cover. In the last three centuries, the town of San Fratello was affected by three large landslides, developed in different periods: the oldest one occurred in 1754, damaging the northeastern sector of the town; in 1922 a large landslide completely destroyed a wide area in the western hillside of the town. In this paper, the attention is focussed on the most recent landslide that occurred on 14 February 2010: in this case, the phenomenon produced the failure of a large sector of the eastern hillside, causing severe damages to buildings and infrastructures. In particular, several slow-moving rotational and translational slides occurred in the area, making it suitable to monitor ground instability through different InSAR techniques. PS-InSAR™ (permanent scatterers SAR interferometry) techniques, using ERS-1/ERS-2, ENVISAT, RADARSAT-1, and COSMO-SkyMed SAR images, were applied to analyze ground displacements during pre- and post-event phases. Moreover, during the post-event phase in March 2010, a GB-InSAR system, able to acquire data continuously every 14 min, was installed collecting ground displacement maps for a period of about three years, until March 2013. Through the integration of space-borne and ground-based data sets, ground deformation velocity maps were obtained, providing a more accurate delimitation of the February 2010 landslide boundary, with respect to the carried out traditional geomorphological field survey. The integration of GB-InSAR and PSI techniques proved to

  19. PETROLEUM RESIDUA SOLUBILITY PARAMETER/POLARITY MAP: STABILITY STUDIES OF RESIDUA PYROLYSIS

    SciTech Connect

    John F. Schabron; A. Troy Pauli; Joseph F. Rovani, Jr.

    1999-04-30

    A new molecular weight/polarity map based on the Scatchard-Hildebrand solubility equation has been developed for petroleum residua. A series of extractions are performed with solvents of increasing solubility parameter, and the fractions are analyzed by vapor pressure osmometry for number average molecular weight and by analytical-scale size exclusion chromatography for molecular weight spread. Work was performed for a heavy oil material subjected to three increasing severities of thermal treatment prior to and through the onset of coke formation. The results are diagnostic of the layers of solvations by resin-type molecules around a central asphaltene core. Two additional stability diagnostic methods were also used. These were the Heithaus titration ''P-index'' and Gaestel ''G'' index, which have been applied to paving asphalts for decades. The Heithaus titration involves the titration of three toluene solutions of a residuum at three concentrations with a poor solvent, such as isooctane, to the point of asphaltene flocculation. In the present work, the significance of the data are developed in terms of the Hildebrand solubility parameter. The Heithaus results are combined with data from the new molecular weight/polarity map. The solubility parameters for the toluene-soluble asphaltene components are measured, and the solubility parameters of the maltenes can be calculated. As thermal treatment progresses, the solubility parameters of asphaltene materials increase and the molecular weights decrease. A new coking index is proposed based on Heithaus titration data. Preliminary results suggest that an alternative, simpler coking index may be developed by measuring the weight percent of cyclohexane solubles in heptane asphaltenes. Coking onset appears to coincide with the depletion of these resin-type asphaltene solubilizing components of residua. The objective of the present study was to develop a mapping tool that will enhance understanding of the changes that occur

  20. Computer generated maps from digital satellite data - A case study in Florida

    NASA Technical Reports Server (NTRS)

    Arvanitis, L. G.; Reich, R. M.; Newburne, R.

    1981-01-01

    Ground cover maps are important tools to a wide array of users. Over the past three decades, much progress has been made in supplementing planimetric and topographic maps with ground cover details obtained from aerial photographs. The present investigation evaluates the feasibility of using computer maps of ground cover from satellite input tapes. Attention is given to the selection of test sites, a satellite data processing system, a multispectral image analyzer, general purpose computer-generated maps, the preliminary evaluation of computer maps, a test for areal correspondence, the preparation of overlays and acreage estimation of land cover types on the Landsat computer maps. There is every indication to suggest that digital multispectral image processing systems based on Landsat input data will play an increasingly important role in pattern recognition and mapping land cover in the years to come.

  1. Performance of corrosion inhibiting admixtures for structural concrete -- assessment methods and predictive modeling

    SciTech Connect

    Yunovich, M.; Thompson, N.G.

    1998-12-31

    During the past fifteen years corrosion inhibiting admixtures (CIAs) have become increasingly popular for protection of reinforced components of highway bridges and other structures from damage induced by chlorides. However, there remains considerable debate about the benefits of CIAs in concrete. A variety of testing methods to assess the performance of CIA have been reported in the literature, ranging from tests in simulated pore solutions to long-term exposures of concrete slabs. The paper reviews the published techniques and recommends the methods which would make up a comprehensive CIA effectiveness testing program. The results of this set of tests would provide the data which can be used to rank the presently commercially available CIA and future candidate formulations utilizing a proposed predictive model. The model is based on relatively short-term laboratory testing and considers several phases of a service life of a structure (corrosion initiation, corrosion propagation without damage, and damage to the structure).

  2. The shaping of modern human immune systems by multiregional admixture with archaic humans.

    PubMed

    Abi-Rached, Laurent; Jobin, Matthew J; Kulkarni, Subhash; McWhinnie, Alasdair; Dalva, Klara; Gragert, Loren; Babrzadeh, Farbod; Gharizadeh, Baback; Luo, Ma; Plummer, Francis A; Kimani, Joshua; Carrington, Mary; Middleton, Derek; Rajalingam, Raja; Beksac, Meral; Marsh, Steven G E; Maiers, Martin; Guethlein, Lisbeth A; Tavoularis, Sofia; Little, Ann-Margaret; Green, Richard E; Norman, Paul J; Parham, Peter

    2011-10-01

    Whole genome comparisons identified introgression from archaic to modern humans. Our analysis of highly polymorphic human leukocyte antigen (HLA) class I, vital immune system components subject to strong balancing selection, shows how modern humans acquired the HLA-B*73 allele in west Asia through admixture with archaic humans called Denisovans, a likely sister group to the Neandertals. Virtual genotyping of Denisovan and Neandertal genomes identified archaic HLA haplotypes carrying functionally distinctive alleles that have introgressed into modern Eurasian and Oceanian populations. These alleles, of which several encode unique or strong ligands for natural killer cell receptors, now represent more than half the HLA alleles of modern Eurasians and also appear to have been later introduced into Africans. Thus, adaptive introgression of archaic alleles has significantly shaped modern human immune systems. PMID:21868630

  3. Chaotic transport and mixing of a passive admixture by vortex flows behind obstacles

    NASA Astrophysics Data System (ADS)

    Ryzhov, E. A.; Koshel', K. V.

    2010-04-01

    A two-layer nonviscous model of chaotic advection in a unidirectional pulsating running current above a delta-shaped underwater elevation is considered. The property of local stability is used and a characteristic similar to the cumulative Lyapunov exponent is introduced that makes it possible to determine the range of regular and chaotic particle behavior. The estimates obtained using this characteristic are for clarifying passive admixture transport in analog model problems. Knowledge of the maximum chaotization region boundary is important for oceanology in view of interpreting point vortices as a model of distributed vortices. The criterion based on using the cubic Hamiltonian approximation for a nonlinear resonance model is introduced to estimate the limiting boundary of the regular region.

  4. Transferrin variants as markers of migrations and admixture between populations in the Baltic Sea region.

    PubMed

    Beckman, L; Sikström, C; Mikelsaar, A V; Krumina, A; Ambrasiene, D; Kucinskas, V; Beckman, G

    1998-01-01

    Transferrin (TF) types were examined by isoelectric focusing in an attempt to elucidate migrations and admixture between populations in the Baltic Sea region. A highly significant heterogeneity between populations was found with respect to TF*C subtypes as well as the rare TF variants B2, B0-1 and DCHI. With the exception for Estonia, increased frequencies of the TF*C3 allele were observed east of the Baltic Sea. The island of Gotland in the middle of the Baltic Sea also showed a high TF*C3 frequency indicating an eastern influence. The TF*DCHI allele, a marker of eastern (Finno-Ugric) influence, was found in Finland and Estonia and on the island of Gotland, but not in mainland Sweden and in the Baltic peoples (Latvians and Lithuanians). These results indicate the presence of a Finno-Ugric, most likely Estonian or Livonian, genetic influence in the Gotland population. PMID:9694249

  5. Investigation of air-entraining admixture dosage in fly ash concrete

    SciTech Connect

    Ley, M.T.; Harris, N.J.; Folliard, K.J.; Hover, K.C.

    2008-09-15

    The amount of air-entraining admixture (AEA) needed to achieve a target air content in fresh concrete can vary significantly with differences in the fly ash used in the concrete. The work presented in this paper evaluates the ability to predict the AEA dosage on the basis of tests on the fly ash alone. All results were compared with the dosage of AEA required to produce an air content of 6% in fresh concrete. Fly ash was sampled from six separate sources. For four of these sources, samples were obtained both before and after the introduction of 'low-NOx burners'. Lack of definitive data about the coal itself or the specifics of the burning processes prevents the ability to draw specific conclusions about the impact of low-NOx burners on AEA demand. Nevertheless, the data suggest that modification of the burning process to meet environmental quality standards may affect the fly ash-AEA interaction.

  6. Numerical studies of the standard nontwist map and a renormalization group framework for breakup of invariant tori

    NASA Astrophysics Data System (ADS)

    Apte, Amit Shriram

    This thesis presents numerical explorations of area-preserving nontwist maps, and a renormalization group framework for the destruction of invariant tori. We study the phenomena of bifurcation and reconnection, and the emergence of meandering tori which are non-KAM invariant curves. We also study the breakup of shearless invariant tori with noble winding numbers using improved numerical techniques to implement Greene's residue criterion. We interpret the breakup of invariant tori within a renormalization group framework by constructing renormalization group operators for the tori with winding numbers that are quadratic irrationals. We find the simple fixed points of these operators and interpret the map pairs with critical invariant tori as critical fixed points. We introduce coordinate transformations on the space of maps to relate these fixed points to each other. These transformations induce conjugacies between the corresponding operators, and provide a new perspective on the space of area-preserving maps.

  7. Expert Opinions on Improving Femicide Data Collection across Europe: A Concept Mapping Study.

    PubMed

    Vives-Cases, Carmen; Goicolea, Isabel; Hernández, Alison; Sanz-Barbero, Belen; Gill, Aisha K; Baldry, Anna Costanza; Schröttle, Monika; Stöckl, Heidi; Stoeckl, Heidi

    2016-01-01

    Femicide, defined as the killings of females by males because they are females, is becoming recognized worldwide as an important ongoing manifestation of gender inequality. Despite its high prevalence or widespread prevalence, only a few countries have specific registries about this issue. This study aims to assemble expert opinion regarding the strategies which might feasibly be employed to promote, develop and implement an integrated and differentiated femicide data collection system in Europe at both the national and international levels. Concept mapping methodology was followed, involving 28 experts from 16 countries in generating strategies, sorting and rating them with respect to relevance and feasibility. The experts involved were all members of the EU-Cost-Action on femicide, which is a scientific network of experts on femicide and violence against women across Europe. As a result, a conceptual map emerged, consisting of 69 strategies organized in 10 clusters, which fit into two domains: "Political action" and "Technical steps". There was consensus among participants regarding the high relevance of strategies to institutionalize national databases and raise public awareness through different stakeholders, while strategies to promote media involvement were identified as the most feasible. Differences in perceived priorities according to the level of human development index of the experts' countries were also observed. PMID:26859885

  8. Mapping Electrochemical Heterogeneity at Iron Oxide Surfaces: A Local Electrochemical Impedance Study.

    PubMed

    Lucas, Marie; Boily, Jean-François

    2015-12-22

    Alternating current scanning electrochemical microscopy (AC-SECM) was used for the first time to map key electrochemical attributes of oriented hematite (α-Fe2O3) single crystal surfaces at the micron-scale. Localized electrochemical impedance spectra (LEIS) of the (001) and (012) faces provided insight into the spatial variations of local double layer capacitance (C(dl)) and charge transfer resistance (R(ad)). These parameters were extracted by LEIS measurements in the 0.4-8000 Hz range to probe the impedance response generated by the redistribution of water molecules and charge carriers (ions) under an applied AC. These were attributed to local variations in the local conductivity of the sample surfaces. Comparison with global EIS measurements on the same samples uncovered highly comparable frequency-resolved processes, that were broken down into contributions from the bulk hematite, the interface as well as the microelectrode/tip assembly. This work paves the way for new studies aimed at mapping electrochemical processes at the mesoscale on this environmentally and technologically important material. PMID:26625255

  9. Expert Opinions on Improving Femicide Data Collection across Europe: A Concept Mapping Study

    PubMed Central

    Vives-Cases, Carmen; Goicolea, Isabel; Hernández, Alison; Sanz-Barbero, Belen; Gill, Aisha K.; Baldry, Anna Costanza; Schröttle, Monika; Stoeckl, Heidi

    2016-01-01

    Femicide, defined as the killings of females by males because they are females, is becoming recognized worldwide as an important ongoing manifestation of gender inequality. Despite its high prevalence or widespread prevalence, only a few countries have specific registries about this issue. This study aims to assemble expert opinion regarding the strategies which might feasibly be employed to promote, develop and implement an integrated and differentiated femicide data collection system in Europe at both the national and international levels. Concept mapping methodology was followed, involving 28 experts from 16 countries in generating strategies, sorting and rating them with respect to relevance and feasibility. The experts involved were all members of the EU-Cost-Action on femicide, which is a scientific network of experts on femicide and violence against women across Europe. As a result, a conceptual map emerged, consisting of 69 strategies organized in 10 clusters, which fit into two domains: “Political action” and “Technical steps”. There was consensus among participants regarding the high relevance of strategies to institutionalize national databases and raise public awareness through different stakeholders, while strategies to promote media involvement were identified as the most feasible. Differences in perceived priorities according to the level of human development index of the experts’ countries were also observed. PMID:26859885

  10. Analytic study of chaos of the tent map: Band structures, power spectra, and critical behaviors

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Mori, H.; Shigematsu, H.

    1983-05-01

    Chaotic behaviors of the tent map (a piecewise-linear, continuous map with a unique maximum) are studied analytically throughout its chaotic region in terms of the invariant density and the power spectrum. As the height of the maximum is lowered, successive band-splitting transitions occur in the chaotic region and accumulate to the transition point into the nonchaotic region. The timecorrelation function of nonperiodic orbits and their power spectrum are calculated exactly at the band-splitting points and in the vicinity of these points. The method of eigenvalue problems of the Frobenius-Perron operator is used. 2 m-1 critical modes, where m = 1,2, 3, ..., are found which exhibit the critical slowing-down near the 2 m-1-band to 2 m -band transition point. After the transition these modes become periodic modes which represent the cycling of nonperiodic orbits among 2 m bands together with the periodic modes generated by the preceding band splittings. Scaling laws near the transition point into the nonchaotic region are investigated and a new scaling law is found for the total intensity of the periodic part of the spectrum.

  11. An Indexed, Mapped Mutant Library Enables Reverse Genetics Studies of Biological Processes in Chlamydomonas reinhardtii.

    PubMed

    Li, Xiaobo; Zhang, Ru; Patena, Weronika; Gang, Spencer S; Blum, Sean R; Ivanova, Nina; Yue, Rebecca; Robertson, Jacob M; Lefebvre, Paul A; Fitz-Gibbon, Sorel T; Grossman, Arthur R; Jonikas, Martin C

    2016-02-01

    The green alga Chlamydomonas reinhardtii is a leading unicellular model for dissecting biological processes in photosynthetic eukaryotes. However, its usefulness has been limited by difficulties in obtaining mutants in specific genes of interest. To allow generation of large numbers of mapped mutants, we developed high-throughput methods that (1) enable easy maintenance of tens of thousands of Chlamydomonas strains by propagation on agar media and by cryogenic storage, (2) identify mutagenic insertion sites and physical coordinates in these collections, and (3) validate the insertion sites in pools of mutants by obtaining >500 bp of flanking genomic sequences. We used these approaches to construct a stably maintained library of 1935 mapped mutants, representing disruptions in 1562 genes. We further characterized randomly selected mutants and found that 33 out of 44 insertion sites (75%) could be confirmed by PCR, and 17 out of 23 mutants (74%) contained a single insertion. To demonstrate the power of this library for elucidating biological processes, we analyzed the lipid content of mutants disrupted in genes encoding proteins of the algal lipid droplet proteome. This study revealed a central role of the long-chain acyl-CoA synthetase LCS2 in the production of triacylglycerol from de novo-synthesized fatty acids. PMID:26764374

  12. Comparison of Different EO Sensors for Mapping Tree Species- A Case Study in Southwest Germany

    NASA Astrophysics Data System (ADS)

    Enβle, Fabian; Kattenborn, Teja; Koch, Barbara

    2014-11-01

    The variety of different remote sensing sensors and thus the types of data specifications which are available is increasing continuously. Especially the differences in geometric, radiometric and temporal resolutions of different platforms affect their ability for the mapping of forests. These differences hinder the comparability and application of uniform methods of different remotely sensed data across the same region of interest. The quality and quantity of retrieved forest parameters is directly dependent on the data source, and therefore the objective of this project is to analyse the relationship between the data source and its derived parameters. A comparison of different optical EO-data (e.g. spatial resolution and spectral resolution of specific bands) will help to define the optimum data sets to produce a reproducible method to provide additional inputs to the Dragon cooperative project, specifically to method development for woody biomass estimation and biodiversity assessment services. This poster presents the first results on tree species mapping in a mixed temperate forest by satellite imagery taken from four different sensors. Tree species addressed in this pilot study are: Scots pine (Pinus sylvestris), sessile oak (Quercus petraea) and red oak (Quercus rubra). The spatial resolution varies from 2m to 30m and the spectral resolutions range from 8bands up to 155bands.

  13. Stimulation mapping of white matter tracts to study brain functional connectivity.

    PubMed

    Duffau, Hugues

    2015-05-01

    Despite advances in the new science of connectomics, which aims to comprehensively map neural connections at both structural and functional levels, techniques to directly study the function of white matter tracts in vivo in humans have proved elusive. Direct electrical stimulation (DES) mapping of the subcortical fibres offers a unique opportunity to investigate the functional connectivity of the brain. This original method permits real-time anatomo-functional correlations, especially with regard to neural pathways, in awake patients undergoing brain surgery. In this article, the goal is to review new insights, gained from axonal DES, into the functional connectivity underlying the sensorimotor, visuospatial, language and sociocognitive systems. Interactions between these neural networks and multimodal systems, such as working memory, attention, executive functions and consciousness, can also be investigated by axonal stimulation. In this networking model of conation and cognition, brain processing is not conceived as the sum of several subfunctions, but results from the integration and potentiation of parallel-though partially overlapping-subnetworks. This hodotopical account, supported by axonal DES, improves our understanding of neuroplasticity and its limitations. The clinical implications of this paradigmatic shift from localizationism to hodotopy, in the context of brain surgery, neurology, neurorehabilitation and psychiatry, are discussed. PMID:25848923

  14. QTL mapping for combining ability in different population-based NCII designs: a simulation study.

    PubMed

    Li, Lanzhi; Sun, Congwei; Chen, Yuan; D