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Sample records for addition genetic studies

  1. Genetic assessment of additional endophenotypes from the Consortium on the Genetics of Schizophrenia Family Study.

    PubMed

    Greenwood, Tiffany A; Lazzeroni, Laura C; Calkins, Monica E; Freedman, Robert; Green, Michael F; Gur, Raquel E; Gur, Ruben C; Light, Gregory A; Nuechterlein, Keith H; Olincy, Ann; Radant, Allen D; Seidman, Larry J; Siever, Larry J; Silverman, Jeremy M; Stone, William S; Sugar, Catherine A; Swerdlow, Neal R; Tsuang, Debby W; Tsuang, Ming T; Turetsky, Bruce I; Braff, David L

    2016-01-01

    The Consortium on the Genetics of Schizophrenia Family Study (COGS-1) has previously reported our efforts to characterize the genetic architecture of 12 primary endophenotypes for schizophrenia. We now report the characterization of 13 additional measures derived from the same endophenotype test paradigms in the COGS-1 families. Nine of the measures were found to discriminate between schizophrenia patients and controls, were significantly heritable (31 to 62%), and were sufficiently independent of previously assessed endophenotypes, demonstrating utility as additional endophenotypes. Genotyping via a custom array of 1536 SNPs from 94 candidate genes identified associations for CTNNA2, ERBB4, GRID1, GRID2, GRIK3, GRIK4, GRIN2B, NOS1AP, NRG1, and RELN across multiple endophenotypes. An experiment-wide p value of 0.003 suggested that the associations across all SNPs and endophenotypes collectively exceeded chance. Linkage analyses performed using a genome-wide SNP array further identified significant or suggestive linkage for six of the candidate endophenotypes, with several genes of interest located beneath the linkage peaks (e.g., CSMD1, DISC1, DLGAP2, GRIK2, GRIN3A, and SLC6A3). While the partial convergence of the association and linkage likely reflects differences in density of gene coverage provided by the distinct genotyping platforms, it is also likely an indication of the differential contribution of rare and common variants for some genes and methodological differences in detection ability. Still, many of the genes implicated by COGS through endophenotypes have been identified by independent studies of common, rare, and de novo variation in schizophrenia, all converging on a functional genetic network related to glutamatergic neurotransmission that warrants further investigation. PMID:26597662

  2. Genetic predisposition to coronary heart disease and stroke using an additive genetic risk score: a population-based study in Greece

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: To determine the extent to which the risk for incident coronary heart disease (CHD) increases in relation to a genetic risk score (GRS) that additively integrates the influence of high-risk alleles in nine documented single nucleotide polymorphisms (SNPs) for CHD, and to examine whether t...

  3. Additive influence of genetic predisposition and conventional risk factors in the incidence of coronary heart disease: a population-based study in Greece

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An additive genetic risk score (GRS) for coronary heart disease (CHD) has previously been associated with incident CHD in the population-based Greek European Prospective Investigation into Cancer and nutrition (EPIC) cohort. In this study, we explore GRS-‘environment’ joint actions on CHD for severa...

  4. Explaining additional genetic variation in complex traits

    PubMed Central

    Robinson, Matthew R.; Wray, Naomi R.; Visscher, Peter M.

    2015-01-01

    Genome-wide association studies (GWAS) have provided valuable insights into the genetic basis of complex traits, discovering >6000 variants associated with >500 quantitative traits and common complex diseases in humans. The associations identified so far represent only a fraction of those which influence phenotype, as there are likely to be very many variants across the entire frequency spectrum, each of which influences multiple traits, with only a small average contribution to the phenotypic variance. This presents a considerable challenge to further dissection of the remaining unexplained genetic variance within populations, which limits our ability to predict disease risk, identify new drug targets, improve and maintain food sources, and understand natural diversity. This challenge will be met within the current framework through larger sample size, better phenotyping including recording of non-genetic risk factors, focused study designs, and an integration of multiple sources of phenotypic and genetic information. The current evidence supports the application of quantitative genetic approaches, and we argue that one should retain simpler theories until simplicity can be traded for greater explanatory power. PMID:24629526

  5. Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: comparing meta and mega analytical approaches for data pooling

    PubMed Central

    Kochunov, Peter; Jahanshad, Neda; Sprooten, Emma; Nichols, Thomas E.; Mandl, René C.; Almasy, Laura; Booth, Tom; Brouwer, Rachel M.; Curran, Joanne E.; de Zubicaray, Greig I.; Dimitrova, Rali; Duggirala, Ravi; Fox, Peter T.; Hong, L. Elliot; Landman, Bennett A.; Lemaitre, Hervé; Lopez, Lorna; Martin, Nicholas G.; McMahon, Katie L.; Mitchell, Braxton D.; Olvera, Rene L.; Peterson, Charles P.; Starr, John M.; Sussmann, Jessika E.; Toga, Arthur W.; Wardlaw, Joanna M.; Wright, Margaret J.; Wright, Susan N.; Bastin, Mark E.; McIntosh, Andrew M.; Boomsma, Dorret I.; Kahn, René S.; den Braber, Anouk; de Geus, Eco JC; Deary, Ian J.; Hulshoff Pol, Hilleke E.; Williamson, Douglas E.; Blangero, John; van ’t Ent, Dennis; Thompson, Paul M.; Glahn, David C.

    2014-01-01

    Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9–85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large “mega-family”. We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability. PMID:24657781

  6. Multi-site study of additive genetic effects on fractional anisotropy of cerebral white matter: Comparing meta and megaanalytical approaches for data pooling.

    PubMed

    Kochunov, Peter; Jahanshad, Neda; Sprooten, Emma; Nichols, Thomas E; Mandl, René C; Almasy, Laura; Booth, Tom; Brouwer, Rachel M; Curran, Joanne E; de Zubicaray, Greig I; Dimitrova, Rali; Duggirala, Ravi; Fox, Peter T; Hong, L Elliot; Landman, Bennett A; Lemaitre, Hervé; Lopez, Lorna M; Martin, Nicholas G; McMahon, Katie L; Mitchell, Braxton D; Olvera, Rene L; Peterson, Charles P; Starr, John M; Sussmann, Jessika E; Toga, Arthur W; Wardlaw, Joanna M; Wright, Margaret J; Wright, Susan N; Bastin, Mark E; McIntosh, Andrew M; Boomsma, Dorret I; Kahn, René S; den Braber, Anouk; de Geus, Eco J C; Deary, Ian J; Hulshoff Pol, Hilleke E; Williamson, Douglas E; Blangero, John; van 't Ent, Dennis; Thompson, Paul M; Glahn, David C

    2014-07-15

    Combining datasets across independent studies can boost statistical power by increasing the numbers of observations and can achieve more accurate estimates of effect sizes. This is especially important for genetic studies where a large number of observations are required to obtain sufficient power to detect and replicate genetic effects. There is a need to develop and evaluate methods for joint-analytical analyses of rich datasets collected in imaging genetics studies. The ENIGMA-DTI consortium is developing and evaluating approaches for obtaining pooled estimates of heritability through meta-and mega-genetic analytical approaches, to estimate the general additive genetic contributions to the intersubject variance in fractional anisotropy (FA) measured from diffusion tensor imaging (DTI). We used the ENIGMA-DTI data harmonization protocol for uniform processing of DTI data from multiple sites. We evaluated this protocol in five family-based cohorts providing data from a total of 2248 children and adults (ages: 9-85) collected with various imaging protocols. We used the imaging genetics analysis tool, SOLAR-Eclipse, to combine twin and family data from Dutch, Australian and Mexican-American cohorts into one large "mega-family". We showed that heritability estimates may vary from one cohort to another. We used two meta-analytical (the sample-size and standard-error weighted) approaches and a mega-genetic analysis to calculate heritability estimates across-population. We performed leave-one-out analysis of the joint estimates of heritability, removing a different cohort each time to understand the estimate variability. Overall, meta- and mega-genetic analyses of heritability produced robust estimates of heritability. PMID:24657781

  7. Additive influence of genetic predisposition and conventional risk factors in the incidence of coronary heart disease: a population-based study in Greece

    PubMed Central

    Yiannakouris, Nikos; Katsoulis, Michail; Trichopoulou, Antonia; Ordovas, Jose M; Trichopoulos, Dimitrios

    2014-01-01

    Objectives An additive genetic risk score (GRS) for coronary heart disease (CHD) has previously been associated with incident CHD in the population-based Greek European Prospective Investigation into Cancer and nutrition (EPIC) cohort. In this study, we explore GRS-‘environment’ joint actions on CHD for several conventional cardiovascular risk factors (ConvRFs), including smoking, hypertension, type-2 diabetes mellitus (T2DM), body mass index (BMI), physical activity and adherence to the Mediterranean diet. Design A case–control study. Setting The general Greek population of the EPIC study. Participants and outcome measures 477 patients with medically confirmed incident CHD and 1271 controls participated in this study. We estimated the ORs for CHD by dividing participants at higher or lower GRS and, alternatively, at higher or lower ConvRF, and calculated the relative excess risk due to interaction (RERI) as a measure of deviation from additivity. Results The joint presence of higher GRS and higher risk ConvRF was in all instances associated with an increased risk of CHD, compared with the joint presence of lower GRS and lower risk ConvRF. The OR (95% CI) was 1.7 (1.2 to 2.4) for smoking, 2.7 (1.9 to 3.8) for hypertension, 4.1 (2.8 to 6.1) for T2DM, 1.9 (1.4 to 2.5) for lower physical activity, 2.0 (1.3 to 3.2) for high BMI and 1.5 (1.1 to 2.1) for poor adherence to the Mediterranean diet. In all instances, RERI values were fairly small and not statistically significant, suggesting that the GRS and the ConvRFs do not have effects beyond additivity. Conclusions Genetic predisposition to CHD, operationalised through a multilocus GRS, and ConvRFs have essentially additive effects on CHD risk. PMID:24500614

  8. Unnatural reactive amino acid genetic code additions

    SciTech Connect

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2011-08-09

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNAsyn-thetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  9. Unnatural reactive amino acid genetic code additions

    SciTech Connect

    Deiters, Alexander; Cropp, Ashton T; Chin, Jason W; Anderson, Christopher J; Schultz, Peter G

    2013-05-21

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  10. Unnatural reactive amino acid genetic code additions

    SciTech Connect

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2014-08-26

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  11. Unnatural reactive amino acid genetic code additions

    SciTech Connect

    Deiters, Alexander; Cropp, T. Ashton; Chin, Jason W.; Anderson, J. Christopher; Schultz, Peter G.

    2011-02-15

    This invention provides compositions and methods for producing translational components that expand the number of genetically encoded amino acids in eukaryotic cells. The components include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, orthogonal pairs of tRNAs/synthetases and unnatural amino acids. Proteins and methods of producing proteins with unnatural amino acids in eukaryotic cells are also provided.

  12. Additive genetic effect of APOE and BDNF on hippocampus activity.

    PubMed

    Kauppi, Karolina; Nilsson, Lars-Göran; Persson, Jonas; Nyberg, Lars

    2014-04-01

    Human memory is a highly heritable polygenic trait with complex inheritance patterns. To study the genetics of memory and memory-related diseases, hippocampal functioning has served as an intermediate phenotype. The importance of investigating gene-gene effects on complex phenotypes has been emphasized, but most imaging studies still focus on single polymorphisms. APOE ε4 and BDNF Met, two of the most studied gene variants for variability in memory performance and neuropsychiatric disorders, have both separately been related to poorer episodic memory and altered hippocampal functioning. Here, we investigated the combined effect of APOE and BDNF on hippocampal activation (N=151). No non-additive interaction effects were seen. Instead, the results revealed decreased activation in bilateral hippocampus and parahippocampus as a function of the number of APOE ε4 and BDNF Met alleles present (neither, one, or both). The combined effect was stronger than either of the individual effects, and both gene variables explained significant proportions of variance in BOLD signal change. Thus, there was an additive gene-gene effect of APOE and BDNF on medial temporal lobe (MTL) activation, showing that a larger proportion of variance in brain activation attributed to genetics can be explained by considering more than one gene variant. This effect might be relevant for the understanding of normal variability in memory function as well as memory-related disorders associated with APOE and BDNF. PMID:24321557

  13. Efficient Improvement of Silage Additives by Using Genetic Algorithms

    PubMed Central

    Davies, Zoe S.; Gilbert, Richard J.; Merry, Roger J.; Kell, Douglas B.; Theodorou, Michael K.; Griffith, Gareth W.

    2000-01-01

    The enormous variety of substances which may be added to forage in order to manipulate and improve the ensilage process presents an empirical, combinatorial optimization problem of great complexity. To investigate the utility of genetic algorithms for designing effective silage additive combinations, a series of small-scale proof of principle silage experiments were performed with fresh ryegrass. Having established that significant biochemical changes occur over an ensilage period as short as 2 days, we performed a series of experiments in which we used 50 silage additive combinations (prepared by using eight bacterial and other additives, each of which was added at six different levels, including zero [i.e., no additive]). The decrease in pH, the increase in lactate concentration, and the free amino acid concentration were measured after 2 days and used to calculate a “fitness” value that indicated the quality of the silage (compared to a control silage made without additives). This analysis also included a “cost” element to account for different total additive levels. In the initial experiment additive levels were selected randomly, but subsequently a genetic algorithm program was used to suggest new additive combinations based on the fitness values determined in the preceding experiments. The result was very efficient selection for silages in which large decreases in pH and high levels of lactate occurred along with low levels of free amino acids. During the series of five experiments, each of which comprised 50 treatments, there was a steady increase in the amount of lactate that accumulated; the best treatment combination was that used in the last experiment, which produced 4.6 times more lactate than the untreated silage. The additive combinations that were found to yield the highest fitness values in the final (fifth) experiment were assessed to determine a range of biochemical and microbiological quality parameters during full-term silage

  14. Additive genetic contribution to symptom dimensions in major depressive disorder.

    PubMed

    Pearson, Rahel; Palmer, Rohan H C; Brick, Leslie A; McGeary, John E; Knopik, Valerie S; Beevers, Christopher G

    2016-05-01

    Major depressive disorder (MDD) is a phenotypically heterogeneous disorder with a complex genetic architecture. In this study, genomic-relatedness-matrix restricted maximum-likelihood analysis (GREML) was used to investigate the extent to which variance in depression symptoms/symptom dimensions can be explained by variation in common single nucleotide polymorphisms (SNPs) in a sample of individuals with MDD (N = 1,558) who participated in the National Institute of Mental Health Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. A principal components analysis of items from the Hamilton Rating Scale for Depression (HRSD) obtained prior to treatment revealed 4 depression symptom components: (a) appetite, (b) core depression symptoms (e.g., depressed mood, anhedonia), (c) insomnia, and (d) anxiety. These symptom dimensions were associated with SNP-based heritability (hSNP2) estimates of 30%, 14%, 30%, and 5%, respectively. Results indicated that the genetic contribution of common SNPs to depression symptom dimensions were not uniform. Appetite and insomnia symptoms in MDD had a relatively strong genetic contribution whereas the genetic contribution was relatively small for core depression and anxiety symptoms. While in need of replication, these results suggest that future gene discovery efforts may strongly benefit from parsing depression into its constituent parts. (PsycINFO Database Record PMID:27124715

  15. Additive and non-additive genetic components of the jack male life history in Chinook salmon (Oncorhynchus tshawytscha).

    PubMed

    Forest, Adriana R; Semeniuk, Christina A D; Heath, Daniel D; Pitcher, Trevor E

    2016-08-01

    Chinook salmon, Oncorhynchus tshawytscha, exhibit alternative reproductive tactics (ARTs) where males exist in two phenotypes: large "hooknose" males and smaller "jacks" that reach sexual maturity after only 1 year in seawater. The mechanisms that determine "jacking rate"-the rate at which males precociously sexually mature-are known to involve both genetics and differential growth rates, where individuals that become jacks exhibit higher growth earlier in life. The additive genetic components have been studied and it is known that jack sires produce significantly more jack offspring than hooknose sires, and vice versa. The current study was the first to investigate both additive and non-additive genetic components underlying jacking through the use of a full-factorial breeding design using all hooknose sires. The effect of dams and sires descendant from a marker-assisted broodstock program that identified "high performance" and "low performance" lines using growth- and survival-related gene markers was also studied. Finally, the relative growth of jack, hooknose, and female offspring was examined. No significant dam, sire, or interaction effects were observed in this study, and the maternal, additive, and non-additive components underlying jacking were small. Differences in jacking rates in this study were determined by dam performance line, where dams that originated from the low performance line produced significantly more jacks. Jack offspring in this study had a significantly larger body size than both hooknose males and females starting 1 year post-fertilization. This study provides novel information regarding the genetic architecture underlying ARTs in Chinook salmon that could have implications for the aquaculture industry, where jacks are not favoured due to their small body size and poor flesh quality. PMID:27450674

  16. Addition polyimide end cap study

    NASA Technical Reports Server (NTRS)

    St.clair, T. L.

    1980-01-01

    The characterization of addition polyimides with various end caps for adhesive applications at 120-250 C environments is discussed. Oligometric polyimides were prepared from 3,3',4,4'-benzophenone tetracarboxylic dianhydride and 3,3'-methylenedianiline which were end-capped with functionally reactive moities which cause crosslinking when the oligomers are heated to 200-400 C. The syntheses of the oligomers are outlined. The thermolysis of the oligomers was studied by differential scanning calorimetry and the resulting polymers were characterized by differential thermal analysis and adhesive performance. The adhesive data include lap shear strengths on titanium 6-4 adherends both before and after aging for 1000 hours at 121 C and/or 232 C.

  17. Genetic interactions contribute less than additive effects to quantitative trait variation in yeast

    PubMed Central

    Bloom, Joshua S.; Kotenko, Iulia; Sadhu, Meru J.; Treusch, Sebastian; Albert, Frank W.; Kruglyak, Leonid

    2015-01-01

    Genetic mapping studies of quantitative traits typically focus on detecting loci that contribute additively to trait variation. Genetic interactions are often proposed as a contributing factor to trait variation, but the relative contribution of interactions to trait variation is a subject of debate. Here we use a very large cross between two yeast strains to accurately estimate the fraction of phenotypic variance due to pairwise QTL–QTL interactions for 20 quantitative traits. We find that this fraction is 9% on average, substantially less than the contribution of additive QTL (43%). Statistically significant QTL–QTL pairs typically have small individual effect sizes, but collectively explain 40% of the pairwise interaction variance. We show that pairwise interaction variance is largely explained by pairs of loci at least one of which has a significant additive effect. These results refine our understanding of the genetic architecture of quantitative traits and help guide future mapping studies. PMID:26537231

  18. Prevalence of gene expression additivity in genetically stable wheat allohexaploids.

    PubMed

    Chelaifa, Houda; Chagué, Véronique; Chalabi, Smahane; Mestiri, Imen; Arnaud, Dominique; Deffains, Denise; Lu, Yunhai; Belcram, Harry; Huteau, Virginie; Chiquet, Julien; Coriton, Olivier; Just, Jérémy; Jahier, Joseph; Chalhoub, Boulos

    2013-02-01

    The reprogramming of gene expression appears as the major trend in synthetic and natural allopolyploids where expression of an important proportion of genes was shown to deviate from that of the parents or the average of the parents. In this study, we analyzed gene expression changes in previously reported, highly stable synthetic wheat allohexaploids that combine the D genome of Aegilops tauschii and the AB genome extracted from the natural hexaploid wheat Triticum aestivum. A comprehensive genome-wide analysis of transcriptional changes using the Affymetrix GeneChip Wheat Genome Array was conducted. Prevalence of gene expression additivity was observed where expression does not deviate from the average of the parents for 99.3% of 34,820 expressed transcripts. Moreover, nearly similar expression was observed (for 99.5% of genes) when comparing these synthetic and natural wheat allohexaploids. Such near-complete additivity has never been reported for other allopolyploids and, more interestingly, for other synthetic wheat allohexaploids that differ from the ones studied here by having the natural tetraploid Triticum turgidum as the AB genome progenitor. Our study gave insights into the dynamics of additive gene expression in the highly stable wheat allohexaploids. PMID:23278496

  19. Common genetic variants, acting additively, are a major source of risk for autism

    PubMed Central

    2012-01-01

    Background Autism spectrum disorders (ASD) are early onset neurodevelopmental syndromes typified by impairments in reciprocal social interaction and communication, accompanied by restricted and repetitive behaviors. While rare and especially de novo genetic variation are known to affect liability, whether common genetic polymorphism plays a substantial role is an open question and the relative contribution of genes and environment is contentious. It is probable that the relative contributions of rare and common variation, as well as environment, differs between ASD families having only a single affected individual (simplex) versus multiplex families who have two or more affected individuals. Methods By using quantitative genetics techniques and the contrast of ASD subjects to controls, we estimate what portion of liability can be explained by additive genetic effects, known as narrow-sense heritability. We evaluate relatives of ASD subjects using the same methods to evaluate the assumptions of the additive model and partition families by simplex/multiplex status to determine how heritability changes with status. Results By analyzing common variation throughout the genome, we show that common genetic polymorphism exerts substantial additive genetic effects on ASD liability and that simplex/multiplex family status has an impact on the identified composition of that risk. As a fraction of the total variation in liability, the estimated narrow-sense heritability exceeds 60% for ASD individuals from multiplex families and is approximately 40% for simplex families. By analyzing parents, unaffected siblings and alleles not transmitted from parents to their affected children, we conclude that the data for simplex ASD families follow the expectation for additive models closely. The data from multiplex families deviate somewhat from an additive model, possibly due to parental assortative mating. Conclusions Our results, when viewed in the context of results from genome

  20. Simultaneous Estimation of Additive and Mutational Genetic Variance in an Outbred Population of Drosophila serrata.

    PubMed

    McGuigan, Katrina; Aguirre, J David; Blows, Mark W

    2015-11-01

    How new mutations contribute to genetic variation is a key question in biology. Although the evolutionary fate of an allele is largely determined by its heterozygous effect, most estimates of mutational variance and mutational effects derive from highly inbred lines, where new mutations are present in homozygous form. In an attempt to overcome this limitation, middle-class neighborhood (MCN) experiments have been used to assess the fitness effect of new mutations in heterozygous form. However, because MCN populations harbor substantial standing genetic variance, estimates of mutational variance have not typically been available from such experiments. Here we employ a modification of the animal model to analyze data from 22 generations of Drosophila serrata bred in an MCN design. Mutational heritability, measured for eight cuticular hydrocarbons, 10 wing-shape traits, and wing size in this outbred genetic background, ranged from 0.0006 to 0.006 (with one exception), a similar range to that reported from studies employing inbred lines. Simultaneously partitioning the additive and mutational variance in the same outbred population allowed us to quantitatively test the ability of mutation-selection balance models to explain the observed levels of additive and mutational genetic variance. The Gaussian allelic approximation and house-of-cards models, which assume real stabilizing selection on single traits, both overestimated the genetic variance maintained at equilibrium, but the house-of-cards model was a closer fit to the data. This analytical approach has the potential to be broadly applied, expanding our understanding of the dynamics of genetic variance in natural populations. PMID:26384357

  1. Searching for additional endocrine functions of the skeleton: genetic approaches and implications for therapeutics

    PubMed Central

    Wei, Jianwen; Flaherty, Stephen; Karsenty, Gerard

    2016-01-01

    Our knowledge of whole organism physiology has greatly advanced in the past decades through mouse genetics. In particular, genetic studies have revealed that most organs interact with one another through hormones in order to maintain normal physiological functions and the homeostasis of the entire organism. Remarkably, through these studies many unexpected novel endocrine means to regulate physiological functions have been uncovered. The skeletal system is one example. In this article, we review a series of studies that over the years have identified bone as an endocrine organ. The mechanism of action, pathological relevance, and therapeutic implications of the functions of the bone-derived hormone osteocalcin are discussed. In the last part of this review we discuss the possibility that additional endocrine functions of the skeleton may exist.

  2. Additive genetic variation and evolvability of a multivariate trait can be increased by epistatic gene action.

    PubMed

    Griswold, Cortland K

    2015-12-21

    Epistatic gene action occurs when mutations or alleles interact to produce a phenotype. Theoretically and empirically it is of interest to know whether gene interactions can facilitate the evolution of diversity. In this paper, we explore how epistatic gene action affects the additive genetic component or heritable component of multivariate trait variation, as well as how epistatic gene action affects the evolvability of multivariate traits. The analysis involves a sexually reproducing and recombining population. Our results indicate that under stabilizing selection conditions a population with a mixed additive and epistatic genetic architecture can have greater multivariate additive genetic variation and evolvability than a population with a purely additive genetic architecture. That greater multivariate additive genetic variation can occur with epistasis is in contrast to previous theory that indicated univariate additive genetic variation is decreased with epistasis under stabilizing selection conditions. In a multivariate setting, epistasis leads to less relative covariance among individuals in their genotypic, as well as their breeding values, which facilitates the maintenance of additive genetic variation and increases a population׳s evolvability. Our analysis involves linking the combinatorial nature of epistatic genetic effects to the ancestral graph structure of a population to provide insight into the consequences of epistasis on multivariate trait variation and evolution. PMID:26431770

  3. Additive Genetic Variation in Schizophrenia Risk Is Shared by Populations of African and European Descent

    PubMed Central

    de Candia, Teresa R.; Lee, S. Hong; Yang, Jian; Browning, Brian L.; Gejman, Pablo V.; Levinson, Douglas F.; Mowry, Bryan J.; Hewitt, John K.; Goddard, Michael E.; O’Donovan, Michael C.; Purcell, Shaun M.; Posthuma, Danielle; Visscher, Peter M.; Wray, Naomi R.; Keller, Matthew C.

    2013-01-01

    To investigate the extent to which the proportion of schizophrenia’s additive genetic variation tagged by SNPs is shared by populations of European and African descent, we analyzed the largest combined African descent (AD [n = 2,142]) and European descent (ED [n = 4,990]) schizophrenia case-control genome-wide association study (GWAS) data set available, the Molecular Genetics of Schizophrenia (MGS) data set. We show how a method that uses genomic similarities at measured SNPs to estimate the additive genetic correlation (SNP correlation [SNP-rg]) between traits can be extended to estimate SNP-rg for the same trait between ethnicities. We estimated SNP-rg for schizophrenia between the MGS ED and MGS AD samples to be 0.66 (SE = 0.23), which is significantly different from 0 (p(SNP-rg = 0) = 0.0003), but not 1 (p(SNP-rg = 1) = 0.26). We re-estimated SNP-rg between an independent ED data set (n = 6,665) and the MGS AD sample to be 0.61 (SE = 0.21, p(SNP-rg = 0) = 0.0003, p(SNP-rg = 1) = 0.16). These results suggest that many schizophrenia risk alleles are shared across ethnic groups and predate African-European divergence. PMID:23954163

  4. Fine-mapping in the MHC region accounts for 18% additional genetic risk for celiac disease

    PubMed Central

    Gutierrez-Achury, Javier; Zhernakova, Alexandra; Pulit, Sara L.; Trynka, Gosia; Hunt, Karen A.; Romanos, Jihane; Raychaudhuri, Soumya; van Heel, David A.; Wijmenga, Cisca; de Bakker, Paul I.W.

    2015-01-01

    Although dietary gluten is the trigger, celiac disease risk is strongly influenced by genetic variation in the major histocompatibility complex (MHC) region. We fine-mapped the MHC association signal to identify additional risk factors independent of the HLA-DQ alleles and observed five novel associations that account for 18% of the genetic risk. Together with the 57 known non-MHC loci, genetic variation can now explain up to 48% of celiac disease heritability. PMID:25894500

  5. Additive genetic variance in polyandry enables its evolution, but polyandry is unlikely to evolve through sexy or good sperm processes.

    PubMed

    Travers, L M; Simmons, L W; Garcia-Gonzalez, F

    2016-05-01

    Polyandry is widespread despite its costs. The sexually selected sperm hypotheses ('sexy' and 'good' sperm) posit that sperm competition plays a role in the evolution of polyandry. Two poorly studied assumptions of these hypotheses are the presence of additive genetic variance in polyandry and sperm competitiveness. Using a quantitative genetic breeding design in a natural population of Drosophila melanogaster, we first established the potential for polyandry to respond to selection. We then investigated whether polyandry can evolve through sexually selected sperm processes. We measured lifetime polyandry and offensive sperm competitiveness (P2 ) while controlling for sampling variance due to male × male × female interactions. We also measured additive genetic variance in egg-to-adult viability and controlled for its effect on P2 estimates. Female lifetime polyandry showed significant and substantial additive genetic variance and evolvability. In contrast, we found little genetic variance or evolvability in P2 or egg-to-adult viability. Additive genetic variance in polyandry highlights its potential to respond to selection. However, the low levels of genetic variance in sperm competitiveness suggest that the evolution of polyandry may not be driven by sexy sperm or good sperm processes. PMID:26801640

  6. Very low levels of direct additive genetic variance in fitness and fitness components in a red squirrel population

    PubMed Central

    McFarlane, S Eryn; Gorrell, Jamieson C; Coltman, David W; Humphries, Murray M; Boutin, Stan; McAdam, Andrew G

    2014-01-01

    A trait must genetically correlate with fitness in order to evolve in response to natural selection, but theory suggests that strong directional selection should erode additive genetic variance in fitness and limit future evolutionary potential. Balancing selection has been proposed as a mechanism that could maintain genetic variance if fitness components trade off with one another and has been invoked to account for empirical observations of higher levels of additive genetic variance in fitness components than would be expected from mutation–selection balance. Here, we used a long-term study of an individually marked population of North American red squirrels (Tamiasciurus hudsonicus) to look for evidence of (1) additive genetic variance in lifetime reproductive success and (2) fitness trade-offs between fitness components, such as male and female fitness or fitness in high- and low-resource environments. “Animal model” analyses of a multigenerational pedigree revealed modest maternal effects on fitness, but very low levels of additive genetic variance in lifetime reproductive success overall as well as fitness measures within each sex and environment. It therefore appears that there are very low levels of direct genetic variance in fitness and fitness components in red squirrels to facilitate contemporary adaptation in this population. PMID:24963372

  7. Genetic studies in alcohol research

    SciTech Connect

    Karp, R.W.

    1994-12-15

    The National Institute on Alcohol Abuse and Alcoholism (NIAAA) supports research to elucidate the specific genetic factors, now largely unknown, which underlie susceptibility to alcoholism and its medical complications (including fetal alcohol syndrome). Because of the genetic complexity and heterogeneity of alcoholism, identification of the multiple underlying factors will require the development of new study designs and methods of analysis of data from human families. While techniques of genetic analysis of animal behavioral traits (e.g., targeted gene disruption, quantitative trait locus (QTL) mapping) are more powerful that those applicable to humans (e.g., linkage and allelic association studies), the validation of animal behaviors as models of aspects of human alcoholism has been problematic. Newly developed methods for mapping QTL influencing animal behavioral traits can not only permit analyses of human family data to be directly informed by the results of animal studies, but can also serve as a novel means of validating animal models of aspects of alcoholism. 55 refs.

  8. The Evolution of Human Intelligence and the Coefficient of Additive Genetic Variance in Human Brain Size

    ERIC Educational Resources Information Center

    Miller, Geoffrey F.; Penke, Lars

    2007-01-01

    Most theories of human mental evolution assume that selection favored higher intelligence and larger brains, which should have reduced genetic variance in both. However, adult human intelligence remains highly heritable, and is genetically correlated with brain size. This conflict might be resolved by estimating the coefficient of additive genetic…

  9. [Genetic study of allergic diseases].

    PubMed

    Zhang, Yuan; Zhang, Luo

    2012-09-01

    Allergic diseases mentioned in this review is regarding to I type allergic inflammation induced by an IgE-mediated reaction, including asthma, allergic rhinitis, atopic dermatitis and food allergy. It is convinced that allergic diseases belong to multiple genes diseases and are controlled by both genetic and environmental factors. Meanwhile there exists gene-gene as well as gene-environment interactions during the development of the disease. The aim of this review is to summarize the toolkit, advance, inherent difficulties and future clinical application prospect in genetic studies of allergic disease. PMID:23214325

  10. Additive genetic variance and developmental plasticity in growth trajectories in a wild cooperative mammal.

    PubMed

    Huchard, E; Charmantier, A; English, S; Bateman, A; Nielsen, J F; Clutton-Brock, T

    2014-09-01

    Individual variation in growth is high in cooperative breeders and may reflect plastic divergence in developmental trajectories leading to breeding vs. helping phenotypes. However, the relative importance of additive genetic variance and developmental plasticity in shaping growth trajectories is largely unknown in cooperative vertebrates. This study exploits weekly sequences of body mass from birth to adulthood to investigate sources of variance in, and covariance between, early and later growth in wild meerkats (Suricata suricatta), a cooperative mongoose. Our results indicate that (i) the correlation between early growth (prior to nutritional independence) and adult mass is positive but weak, and there are frequent changes (compensatory growth) in post-independence growth trajectories; (ii) among parameters describing growth trajectories, those describing growth rate (prior to and at nutritional independence) show undetectable heritability while associated size parameters (mass at nutritional independence and asymptotic mass) are moderately heritable (0.09 ≤ h(2) < 0.3); and (iii) additive genetic effects, rather than early environmental effects, mediate the covariance between early growth and adult mass. These results reveal that meerkat growth trajectories remain plastic throughout development, rather than showing early and irreversible divergence, and that the weak effects of early growth on adult mass, an important determinant of breeding success, are partly genetic. In contrast to most cooperative invertebrates, the acquisition of breeding status is often determined after sexual maturity and strongly impacted by chance in many cooperative vertebrates, who may therefore retain the ability to adjust their morphology to environmental changes and social opportunities arising throughout their development, rather than specializing early. PMID:24962704

  11. Estimation of Additive, Dominance, and Imprinting Genetic Variance Using Genomic Data

    PubMed Central

    Lopes, Marcos S.; Bastiaansen, John W. M.; Janss, Luc; Knol, Egbert F.; Bovenhuis, Henk

    2015-01-01

    Traditionally, exploration of genetic variance in humans, plants, and livestock species has been limited mostly to the use of additive effects estimated using pedigree data. However, with the development of dense panels of single-nucleotide polymorphisms (SNPs), the exploration of genetic variation of complex traits is moving from quantifying the resemblance between family members to the dissection of genetic variation at individual loci. With SNPs, we were able to quantify the contribution of additive, dominance, and imprinting variance to the total genetic variance by using a SNP regression method. The method was validated in simulated data and applied to three traits (number of teats, backfat, and lifetime daily gain) in three purebred pig populations. In simulated data, the estimates of additive, dominance, and imprinting variance were very close to the simulated values. In real data, dominance effects account for a substantial proportion of the total genetic variance (up to 44%) for these traits in these populations. The contribution of imprinting to the total phenotypic variance of the evaluated traits was relatively small (1–3%). Our results indicate a strong relationship between additive variance explained per chromosome and chromosome length, which has been described previously for other traits in other species. We also show that a similar linear relationship exists for dominance and imprinting variance. These novel results improve our understanding of the genetic architecture of the evaluated traits and shows promise to apply the SNP regression method to other traits and species, including human diseases. PMID:26438289

  12. The Ischemic Stroke Genetics Study (ISGS) Protocol

    PubMed Central

    Meschia, James F; Brott, Thomas G; Brown, Robert D; Crook, Richard JP; Frankel, Michael; Hardy, John; Merino, José G; Rich, Stephen S; Silliman, Scott; Worrall, Bradford Burke

    2003-01-01

    Background The molecular basis for the genetic risk of ischemic stroke is likely to be multigenic and influenced by environmental factors. Several small case-control studies have suggested associations between ischemic stroke and polymorphisms of genes that code for coagulation cascade proteins and platelet receptors. Our aim is to investigate potential associations between hemostatic gene polymorphisms and ischemic stroke, with particular emphasis on detailed characterization of the phenotype. Methods/Design The Ischemic Stroke Genetic Study is a prospective, multicenter genetic association study in adults with recent first-ever ischemic stroke confirmed with computed tomography or magnetic resonance imaging. Patients are evaluated at academic medical centers in the United States and compared with sex- and age-matched controls. Stroke subtypes are determined by central blinded adjudication using standardized, validated mechanistic and syndromic classification systems. The panel of genes to be tested for polymorphisms includes β-fibrinogen and platelet glycoprotein Ia, Iba, and IIb/IIIa. Immortalized cell lines are created to allow for time- and cost-efficient testing of additional candidate genes in the future. Discussion The study is designed to minimize survival bias and to allow for exploring associations between specific polymorphisms and individual subtypes of ischemic stroke. The data set will also permit the study of genetic determinants of stroke outcome. Having cell lines will permit testing of future candidate risk factor genes. PMID:12848902

  13. [Food additives and genetically modified food--a risk for allergic patients?].

    PubMed

    Wüthrich, B

    1999-04-01

    Adverse reactions to food and food additives must be classified according to pathogenic criteria. It is necessary to strictly differentiate between an allergy, triggered by a substance-specific immunological mechanism, and an intolerance, in which no specific immune reaction can be established. In contrast to views expressed in the media, by laymen and patients, adverse reactions to additives are less frequent than is believed. Due to frequently "alternative" methods of examination, an allergy to food additives is often wrongly blamed as the cause of a wide variety of symptoms and illness. Diagnosing an allergy or intolerance to additives normally involves carrying out double-blind, placebo-controlled oral provocation tests with food additives. Allergic reactions to food additives occur particularly against additives which are organic in origin. In principle, it is possible that during the manufacture of genetically modified plants and food, proteins are transferred which potentially create allergies. However, legislation exists both in the USA (Federal Drug Administration, FDA) and in Switzerland (Ordinance on the approval process for GM food, GM food additives and GM accessory agents for processing) which require a careful analysis before a genetically modified product is launched, particularly where foreign genes are introduced. Products containing genetically modified organisms (GMO) as additives must be declared. In addition, the source of the foreign protein must be identified. The "Round-up ready" (RR) soya flour introduced in Switzerland is no different from natural soya flour in terms of its allergenic potential. Genetically modified food can be a blessing for allergic individuals if gene technology were to succeed in removing the allergen (e.g. such possibilities exist for rice). The same caution shown towards genetically modified food might also be advisable for foreign food in our diet. Luckily, the immune system of the digestive tract in healthy people

  14. Genetic Rearrangements of Six Wheat–Agropyron cristatum 6P Addition Lines Revealed by Molecular Markers

    PubMed Central

    Su, Junji; Zhang, Jinpeng; Song, Liqiang; Gao, Ainong; Yang, Xinming; Li, Xiuquan; Liu, Weihua; Li, Lihui

    2014-01-01

    Agropyron cristatum (L.) Gaertn. (2n = 4x = 28, PPPP) not only is cultivated as pasture fodder but also could provide many desirable genes for wheat improvement. It is critical to obtain common wheat–A. cristatum alien disomic addition lines to locate the desired genes on the P genome chromosomes. Comparative analysis of the homoeologous relationships between the P genome chromosome and wheat genome chromosomes is a key step in transferring different desirable genes into common wheat and producing the desired alien translocation line while compensating for the loss of wheat chromatin. In this study, six common wheat–A. cristatum disomic addition lines were produced and analyzed by phenotypic examination, genomic in situ hybridization (GISH), SSR markers from the ABD genomes and STS markers from the P genome. Comparative maps, six in total, were generated and demonstrated that all six addition lines belonged to homoeologous group 6. However, chromosome 6P had undergone obvious rearrangements in different addition lines compared with the wheat chromosome, indicating that to obtain a genetic compensating alien translocation line, one should recombine alien chromosomal regions with homoeologous wheat chromosomes. Indeed, these addition lines were classified into four types based on the comparative mapping: 6PI, 6PII, 6PIII, and 6PIV. The different types of chromosome 6P possessed different desirable genes. For example, the 6PI type, containing three addition lines, carried genes conferring high numbers of kernels per spike and resistance to powdery mildew, important traits for wheat improvement. These results may prove valuable for promoting the development of conventional chromosome engineering techniques toward molecular chromosome engineering. PMID:24595330

  15. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 1 2011-10-01 2011-10-01 false Additional requirements prohibiting discrimination based on genetic information. 146.122 Section 146.122 Public Welfare DEPARTMENT OF HEALTH AND HUMAN SERVICES REQUIREMENTS RELATING TO HEALTH CARE ACCESS REQUIREMENTS FOR THE GROUP HEALTH INSURANCE MARKET Requirements Relating to Access...

  16. 26 CFR 54.9802-3T - Additional requirements prohibiting discrimination based on genetic information (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 17 2014-04-01 2014-04-01 false Additional requirements prohibiting discrimination based on genetic information (temporary). 54.9802-3T Section 54.9802-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.9802-3T...

  17. 29 CFR 2590.702-1 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 9 2014-07-01 2014-07-01 false Additional requirements prohibiting discrimination based on genetic information. 2590.702-1 Section 2590.702-1 Labor Regulations Relating to Labor (Continued) EMPLOYEE BENEFITS SECURITY ADMINISTRATION, DEPARTMENT OF LABOR GROUP HEALTH PLANS RULES AND REGULATIONS FOR GROUP HEALTH PLANS Health...

  18. 26 CFR 54.9802-3T - Additional requirements prohibiting discrimination based on genetic information (temporary).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 26 Internal Revenue 17 2012-04-01 2012-04-01 false Additional requirements prohibiting discrimination based on genetic information (temporary). 54.9802-3T Section 54.9802-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.9802-3T...

  19. 26 CFR 54.9802-3T - Additional requirements prohibiting discrimination based on genetic information (temporary).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 26 Internal Revenue 17 2013-04-01 2013-04-01 false Additional requirements prohibiting discrimination based on genetic information (temporary). 54.9802-3T Section 54.9802-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY (CONTINUED) MISCELLANEOUS EXCISE TAXES (CONTINUED) PENSION EXCISE TAXES § 54.9802-3T...

  20. Studies in genetic discrimination. Final progress report

    SciTech Connect

    Not Available

    1994-06-01

    We have screened 1006 respondents in a study of genetic discrimination. Analysis of these responses has produced evidence of the range of institutions engaged in genetic discrimination and demonstrates the impact of this discrimination on the respondents to the study. We have found that both ignorance and policy underlie genetic discrimination and that anti-discrimination laws are being violated.

  1. Genome-Enabled Estimates of Additive and Nonadditive Genetic Variances and Prediction of Apple Phenotypes Across Environments

    PubMed Central

    Kumar, Satish; Molloy, Claire; Muñoz, Patricio; Daetwyler, Hans; Chagné, David; Volz, Richard

    2015-01-01

    The nonadditive genetic effects may have an important contribution to total genetic variation of phenotypes, so estimates of both the additive and nonadditive effects are desirable for breeding and selection purposes. Our main objectives were to: estimate additive, dominance and epistatic variances of apple (Malus × domestica Borkh.) phenotypes using relationship matrices constructed from genome-wide dense single nucleotide polymorphism (SNP) markers; and compare the accuracy of genomic predictions using genomic best linear unbiased prediction models with or without including nonadditive genetic effects. A set of 247 clonally replicated individuals was assessed for six fruit quality traits at two sites, and also genotyped using an Illumina 8K SNP array. Across several fruit quality traits, the additive, dominance, and epistatic effects contributed about 30%, 16%, and 19%, respectively, to the total phenotypic variance. Models ignoring nonadditive components yielded upwardly biased estimates of additive variance (heritability) for all traits in this study. The accuracy of genomic predicted genetic values (GEGV) varied from about 0.15 to 0.35 for various traits, and these were almost identical for models with or without including nonadditive effects. However, models including nonadditive genetic effects further reduced the bias of GEGV. Between-site genotypic correlations were high (>0.85) for all traits, and genotype-site interaction accounted for <10% of the phenotypic variability. The accuracy of prediction, when the validation set was present only at one site, was generally similar for both sites, and varied from about 0.50 to 0.85. The prediction accuracies were strongly influenced by trait heritability, and genetic relatedness between the training and validation families. PMID:26497141

  2. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  3. Additional EIPC Study Analysis. Final Report

    SciTech Connect

    Hadley, Stanton W; Gotham, Douglas J.; Luciani, Ralph L.

    2014-12-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 14 topics was developed for further analysis. This paper brings together the earlier interim reports of the first 13 topics plus one additional topic into a single final report.

  4. Additive genetic risk from five serotonin system polymorphisms interacts with interpersonal stress to predict depression.

    PubMed

    Vrshek-Schallhorn, Suzanne; Stroud, Catherine B; Mineka, Susan; Zinbarg, Richard E; Adam, Emma K; Redei, Eva E; Hammen, Constance; Craske, Michelle G

    2015-11-01

    Behavioral genetic research supports polygenic models of depression in which many genetic variations each contribute a small amount of risk, and prevailing diathesis-stress models suggest gene-environment interactions (G×E). Multilocus profile scores of additive risk offer an approach that is consistent with polygenic models of depression risk. In a first demonstration of this approach in a G×E predicting depression, we created an additive multilocus profile score from 5 serotonin system polymorphisms (1 each in the genes HTR1A, HTR2A, HTR2C, and 2 in TPH2). Analyses focused on 2 forms of interpersonal stress as environmental risk factors. Using 5 years of longitudinal diagnostic and life stress interviews from 387 emerging young adults in the Youth Emotion Project, survival analyses show that this multilocus profile score interacts with major interpersonal stressful life events to predict major depressive episode onsets (hazard ratio [HR] = 1.815, p = .007). Simultaneously, there was a significant protective effect of the profile score without a recent event (HR = 0.83, p = .030). The G×E effect with interpersonal chronic stress was not significant (HR = 1.15, p = .165). Finally, effect sizes for genetic factors examined ignoring stress suggested such an approach could lead to overlooking or misinterpreting genetic effects. Both the G×E effect and the protective simple main effect were replicated in a sample of early adolescent girls (N = 105). We discuss potential benefits of the multilocus genetic profile score approach and caveats for future research. PMID:26595467

  5. Pattern of inbreeding depression, condition dependence, and additive genetic variance in Trinidadian guppy ejaculate traits

    PubMed Central

    Gasparini, Clelia; Devigili, Alessandro; Dosselli, Ryan; Pilastro, Andrea

    2013-01-01

    In polyandrous species, a male's reproductive success depends on his fertilization capability and traits enhancing competitive fertilization success will be under strong, directional selection. This leads to the prediction that these traits should show stronger condition dependence and larger genetic variance than other traits subject to weaker or stabilizing selection. While empirical evidence of condition dependence in postcopulatory traits is increasing, the comparison between sexually selected and ‘control’ traits is often based on untested assumption concerning the different strength of selection acting on these traits. Furthermore, information on selection in the past is essential, as both condition dependence and genetic variance of a trait are likely to be influenced by the pattern of selection acting historically on it. Using the guppy (Poecilia reticulata), a livebearing fish with high levels of multiple paternity, we performed three independent experiments on three ejaculate quality traits, sperm number, velocity, and size, which have been previously shown to be subject to strong, intermediate, and weak directional postcopulatory selection, respectively. First, we conducted an inbreeding experiment to determine the pattern of selection in the past. Second, we used a diet restriction experiment to estimate their level of condition dependence. Third, we used a half-sib/full-sib mating design to estimate the coefficients of additive genetic variance (CVA) underlying these traits. Additionally, using a simulated predator evasion test, we showed that both inbreeding and diet restriction significantly reduced condition. According to predictions, sperm number showed higher inbreeding depression, stronger condition dependence, and larger CVA than sperm velocity and sperm size. The lack of significant genetic correlation between sperm number and velocity suggests that the former may respond to selection independently one from other ejaculate quality traits

  6. Quantitative genetic studies of antisocial behaviour.

    PubMed

    Viding, Essi; Larsson, Henrik; Jones, Alice P

    2008-08-12

    This paper will broadly review the currently available twin and adoption data on antisocial behaviour (AB). It is argued that quantitative genetic research can make a significant contribution to further the understanding of how AB develops. Genetically informative study designs are particularly useful for investigating several important questions such as whether: the heritability estimates vary as a function of assessment method or gender; the relative importance of genetic and environmental influences varies for different types of AB; the environmental risk factors are truly environmental; and genetic vulnerability influences susceptibility to environmental risk. While the current data are not yet directly translatable for prevention and treatment programmes, quantitative genetic research has concrete translational potential. Quantitative genetic research can supplement neuroscience research in informing about different subtypes of AB, such as AB coupled with callous-unemotional traits. Quantitative genetic research is also important in advancing the understanding of the mechanisms by which environmental risk operates. PMID:18434281

  7. Progress in genetic association studies of plasma lipids

    PubMed Central

    Asselbergs, Folkert W.; Lovering, Ruth C.; Drenos, Fotios

    2013-01-01

    Purpose of review This review summarizes recently published large-scale efforts elucidating the genetic architecture of lipid levels. A supplemental file with all genetic loci is provided for research purposes and we performed bioinformatic analyses of the genetic variants to give an oversight of involved pathways. Recent findings In total, 52 genes for HDL cholesterol, 42 genes for LDL cholesterol, 59 genes for total cholesterol, and 39 genes for triglycerides have been identified. Genetic overlap is present between the different traits and similar pathways are involved. Most of the SNPs that were detected in the European studies could be replicated in other ethnicities and these SNPs show the same direction of effect suggesting that the underlying genetic architecture of blood lipids is similar between ethnicities. Summary Genetic studies have identified many loci associated with plasma lipids and have provided insight into the underlying mechanisms of lipid homeostasis. Future research is needed to determine whether these loci may be novel targets for lipid-lowering therapy and for reducing cardiovascular disease risk. In addition, the proportion of genetic variance explained by these lipid loci is still limited and new large-scale genetic studies are ongoing to identify additional common and rare variants associated with lipid levels. PMID:23385652

  8. Genetic breeding and diversity of the genus Passiflora: progress and perspectives in molecular and genetic studies.

    PubMed

    Cerqueira-Silva, Carlos Bernard M; Jesus, Onildo N; Santos, Elisa S L; Corrêa, Ronan X; Souza, Anete P

    2014-01-01

    Despite the ecological and economic importance of passion fruit (Passiflora spp.), molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i) to present the current condition of the passion fruit crop; (ii) to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii) to present the contributions of genetic engineering for passion fruit culture; and (iv) to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit. PMID:25196515

  9. Genetic Breeding and Diversity of the Genus Passiflora: Progress and Perspectives in Molecular and Genetic Studies

    PubMed Central

    Cerqueira-Silva, Carlos Bernard M.; Jesus, Onildo N.; Santos, Elisa S. L.; Corrêa, Ronan X.; Souza, Anete P.

    2014-01-01

    Despite the ecological and economic importance of passion fruit (Passiflora spp.), molecular markers have only recently been utilized in genetic studies of this genus. In addition, both basic genetic researches related to population studies and pre-breeding programs of passion fruit remain scarce for most Passiflora species. Considering the number of Passiflora species and the increasing use of these species as a resource for ornamental, medicinal, and food purposes, the aims of this review are the following: (i) to present the current condition of the passion fruit crop; (ii) to quantify the applications and effects of using molecular markers in studies of Passiflora; (iii) to present the contributions of genetic engineering for passion fruit culture; and (iv) to discuss the progress and perspectives of this research. Thus, the present review aims to summarize and discuss the relationship between historical and current progress on the culture, breeding, and molecular genetics of passion fruit. PMID:25196515

  10. Effect of multiplicative and additive noise on genetic transcriptional regulatory mechanism

    NASA Astrophysics Data System (ADS)

    Liu, Xue-Mei; Xie, Hui-Zhang; Liu, Liang-Gang; Li, Zhi-Bing

    2009-02-01

    A multiplicative noise and an additive noise are introduced in the kinetic model of Smolen-Baxter-Byrne [P. Smolen, D.A. Baxter, J.H. Byrne, Amer. J. Physiol. Cell. Physiol. 274 (1998) 531], in which the expression of gene is controlled by protein concentration of transcriptional activator. The Fokker-Planck equation is solved and the steady-state probability distribution is obtained numerically. It is found that the multiplicative noise converts the bistability to monostability that can be regarded as a noise-induced transition. The additive noise reduces the transcription efficiency. The correlation between the multiplicative noise and the additive noise works as a genetic switch and regulates the gene transcription effectively.

  11. Additive genetic variation for tolerance to estrogen pollution in natural populations of Alpine whitefish (Coregonus sp., Salmonidae)

    PubMed Central

    Brazzola, Gregory; Chèvre, Nathalie; Wedekind, Claus

    2014-01-01

    The evolutionary potential of natural populations to adapt to anthropogenic threats critically depends on whether there exists additive genetic variation for tolerance to the threat. A major problem for water-dwelling organisms is chemical pollution, and among the most common pollutants is 17α-ethinylestradiol (EE2), the synthetic estrogen that is used in oral contraceptives and that can affect fish at various developmental stages, including embryogenesis. We tested whether there is variation in the tolerance to EE2 within Alpine whitefish. We sampled spawners from two species of different lakes, bred them in vitro in a full-factorial design each, and studied growth and mortality of embryos. Exposure to EE2 turned out to be toxic in all concentrations we tested (≥1 ng/L). It reduced embryo viability and slowed down embryogenesis. We found significant additive genetic variation in EE2-induced mortality in both species, that is, genotypes differed in their tolerance to estrogen pollution. We also found maternal effects on embryo development to be influenced by EE2, that is, some maternal sib groups were more susceptible to EE2 than others. In conclusion, the toxic effects of EE2 were strong, but both species demonstrated the kind of additive genetic variation that is necessary for an evolutionary response to this type of pollution. PMID:25553069

  12. Additive genetic variation for tolerance to estrogen pollution in natural populations of Alpine whitefish (Coregonus sp., Salmonidae).

    PubMed

    Brazzola, Gregory; Chèvre, Nathalie; Wedekind, Claus

    2014-11-01

    The evolutionary potential of natural populations to adapt to anthropogenic threats critically depends on whether there exists additive genetic variation for tolerance to the threat. A major problem for water-dwelling organisms is chemical pollution, and among the most common pollutants is 17α-ethinylestradiol (EE2), the synthetic estrogen that is used in oral contraceptives and that can affect fish at various developmental stages, including embryogenesis. We tested whether there is variation in the tolerance to EE2 within Alpine whitefish. We sampled spawners from two species of different lakes, bred them in vitro in a full-factorial design each, and studied growth and mortality of embryos. Exposure to EE2 turned out to be toxic in all concentrations we tested (≥1 ng/L). It reduced embryo viability and slowed down embryogenesis. We found significant additive genetic variation in EE2-induced mortality in both species, that is, genotypes differed in their tolerance to estrogen pollution. We also found maternal effects on embryo development to be influenced by EE2, that is, some maternal sib groups were more susceptible to EE2 than others. In conclusion, the toxic effects of EE2 were strong, but both species demonstrated the kind of additive genetic variation that is necessary for an evolutionary response to this type of pollution. PMID:25553069

  13. FEMALE AND MALE GENETIC EFFECTS ON OFFSPRING PATERNITY: ADDITIVE GENETIC (CO)VARIANCES IN FEMALE EXTRA-PAIR REPRODUCTION AND MALE PATERNITY SUCCESS IN SONG SPARROWS (MELOSPIZA MELODIA)

    PubMed Central

    Reid, Jane M; Arcese, Peter; Keller, Lukas F; Losdat, Sylvain

    2014-01-01

    Ongoing evolution of polyandry, and consequent extra-pair reproduction in socially monogamous systems, is hypothesized to be facilitated by indirect selection stemming from cross-sex genetic covariances with components of male fitness. Specifically, polyandry is hypothesized to create positive genetic covariance with male paternity success due to inevitable assortative reproduction, driving ongoing coevolution. However, it remains unclear whether such covariances could or do emerge within complex polyandrous systems. First, we illustrate that genetic covariances between female extra-pair reproduction and male within-pair paternity success might be constrained in socially monogamous systems where female and male additive genetic effects can have opposing impacts on the paternity of jointly reared offspring. Second, we demonstrate nonzero additive genetic variance in female liability for extra-pair reproduction and male liability for within-pair paternity success, modeled as direct and associative genetic effects on offspring paternity, respectively, in free-living song sparrows (Melospiza melodia). The posterior mean additive genetic covariance between these liabilities was slightly positive, but the credible interval was wide and overlapped zero. Therefore, although substantial total additive genetic variance exists, the hypothesis that ongoing evolution of female extra-pair reproduction is facilitated by genetic covariance with male within-pair paternity success cannot yet be definitively supported or rejected either conceptually or empirically. PMID:24724612

  14. Planning additional drilling campaign using two-space genetic algorithm: A game theoretical approach

    NASA Astrophysics Data System (ADS)

    Kumral, Mustafa; Ozer, Umit

    2013-03-01

    Grade and tonnage are the most important technical uncertainties in mining ventures because of the use of estimations/simulations, which are mostly generated from drill data. Open pit mines are planned and designed on the basis of the blocks representing the entire orebody. Each block has different estimation/simulation variance reflecting uncertainty to some extent. The estimation/simulation realizations are submitted to mine production scheduling process. However, the use of a block model with varying estimation/simulation variances will lead to serious risk in the scheduling. In the medium of multiple simulations, the dispersion variances of blocks can be thought to regard technical uncertainties. However, the dispersion variance cannot handle uncertainty associated with varying estimation/simulation variances of blocks. This paper proposes an approach that generates the configuration of the best additional drilling campaign to generate more homogenous estimation/simulation variances of blocks. In other words, the objective is to find the best drilling configuration in such a way as to minimize grade uncertainty under budget constraint. Uncertainty measure of the optimization process in this paper is interpolation variance, which considers data locations and grades. The problem is expressed as a minmax problem, which focuses on finding the best worst-case performance i.e., minimizing interpolation variance of the block generating maximum interpolation variance. Since the optimization model requires computing the interpolation variances of blocks being simulated/estimated in each iteration, the problem cannot be solved by standard optimization tools. This motivates to use two-space genetic algorithm (GA) approach to solve the problem. The technique has two spaces: feasible drill hole configuration with minimization of interpolation variance and drill hole simulations with maximization of interpolation variance. Two-space interacts to find a minmax solution

  15. Characterizing the ADHD Phenotype for Genetic Studies

    ERIC Educational Resources Information Center

    Stevenson, Jim; Asherson, Phil; Hay, David; Levy, Florence; Swanson, Jim; Thapar, Anita; Willcutt, Erik

    2005-01-01

    The genetic study of ADHD has made considerable progress. Further developments in the field will be reliant in part on identifying the most appropriate phenotypes for genetic analysis. The use of both categorical and dimensional measures of symptoms related to ADHD has been productive. The use of multiple reporters is a valuable feature of the…

  16. Structure Property Studies for Additively Manufactured Parts

    SciTech Connect

    Milenski, Helen M; Schmalzer, Andrew Michael; Kelly, Daniel

    2015-08-17

    Since the invention of modern Additive Manufacturing (AM) processes engineers and designers have worked hard to capitalize on the unique building capabilities that AM allows. By being able to customize the interior fill of parts it is now possible to design components with a controlled density and customized internal structure. The creation of new polymers and polymer composites allow for even greater control over the mechanical properties of AM parts. One of the key reasons to explore AM, is to bring about a new paradigm in part design, where materials can be strategically optimized in a way that conventional subtractive methods cannot achieve. The two processes investigated in my research were the Fused Deposition Modeling (FDM) process and the Direct Ink Write (DIW) process. The objectives of the research were to determine the impact of in-fill density and morphology on the mechanical properties of FDM parts, and to determine if DIW printed samples could be produced where the filament diameter was varied while the overall density remained constant.

  17. Genetic and Epigenetic Changes in Oilseed Rape (Brassica napus L.) Extracted from Intergeneric Allopolyploid and Additions with Orychophragmus.

    PubMed

    Gautam, Mayank; Dang, Yanwei; Ge, Xianhong; Shao, Yujiao; Li, Zaiyun

    2016-01-01

    Allopolyploidization with the merger of the genomes from different species has been shown to be associated with genetic and epigenetic changes. But the maintenance of such alterations related to one parental species after the genome is extracted from the allopolyploid remains to be detected. In this study, the genome of Brassica napus L. (2n = 38, genomes AACC) was extracted from its intergeneric allohexaploid (2n = 62, genomes AACCOO) with another crucifer Orychophragmus violaceus (2n = 24, genome OO), by backcrossing and development of alien addition lines. B. napus-type plants identified in the self-pollinated progenies of nine monosomic additions were analyzed by the methods of amplified fragment length polymorphism, sequence-specific amplified polymorphism, and methylation-sensitive amplified polymorphism. They showed modifications to certain extents in genomic components (loss and gain of DNA segments and transposons, introgression of alien DNA segments) and DNA methylation, compared with B. napus donor. The significant differences in the changes between the B. napus types extracted from these additions likely resulted from the different effects of individual alien chromosomes. Particularly, the additions which harbored the O. violaceus chromosome carrying dominant rRNA genes over those of B. napus tended to result in the development of plants which showed fewer changes, suggesting a role of the expression levels of alien rRNA genes in genomic stability. These results provided new cues for the genetic alterations in one parental genome that are maintained even after the genome becomes independent. PMID:27148282

  18. Genetic and Epigenetic Changes in Oilseed Rape (Brassica napus L.) Extracted from Intergeneric Allopolyploid and Additions with Orychophragmus

    PubMed Central

    Gautam, Mayank; Dang, Yanwei; Ge, Xianhong; Shao, Yujiao; Li, Zaiyun

    2016-01-01

    Allopolyploidization with the merger of the genomes from different species has been shown to be associated with genetic and epigenetic changes. But the maintenance of such alterations related to one parental species after the genome is extracted from the allopolyploid remains to be detected. In this study, the genome of Brassica napus L. (2n = 38, genomes AACC) was extracted from its intergeneric allohexaploid (2n = 62, genomes AACCOO) with another crucifer Orychophragmus violaceus (2n = 24, genome OO), by backcrossing and development of alien addition lines. B. napus-type plants identified in the self-pollinated progenies of nine monosomic additions were analyzed by the methods of amplified fragment length polymorphism, sequence-specific amplified polymorphism, and methylation-sensitive amplified polymorphism. They showed modifications to certain extents in genomic components (loss and gain of DNA segments and transposons, introgression of alien DNA segments) and DNA methylation, compared with B. napus donor. The significant differences in the changes between the B. napus types extracted from these additions likely resulted from the different effects of individual alien chromosomes. Particularly, the additions which harbored the O. violaceus chromosome carrying dominant rRNA genes over those of B. napus tended to result in the development of plants which showed fewer changes, suggesting a role of the expression levels of alien rRNA genes in genomic stability. These results provided new cues for the genetic alterations in one parental genome that are maintained even after the genome becomes independent. PMID:27148282

  19. Heritability of heterozygosity offers a new way of understanding why dominant gene action contributes to additive genetic variance.

    PubMed

    Nietlisbach, Pirmin; Hadfield, Jarrod D

    2015-07-01

    Whenever allele frequencies are unequal, nonadditive gene action contributes to additive genetic variance and therefore the resemblance between parents and offspring. The reason for this has not been easy to understand. Here, we present a new single-locus decomposition of additive genetic variance that may give greater intuition about this important result. We show that the contribution of dominant gene action to parent-offspring resemblance only depends on the degree to which the heterozygosity of parents and offspring covary. Thus, dominant gene action only contributes to additive genetic variance when heterozygosity is heritable. Under most circumstances this is the case because individuals with rare alleles are more likely to be heterozygous, and because they pass rare alleles to their offspring they also tend to have heterozygous offspring. When segregating alleles are at equal frequency there are no rare alleles, the heterozygosities of parents and offspring are uncorrelated and dominant gene action does not contribute to additive genetic variance. PMID:26100570

  20. WONOEP appraisal: new genetic approaches to study epilepsy.

    PubMed

    Rossignol, Elsa; Kobow, Katja; Simonato, Michele; Loeb, Jeffrey A; Grisar, Thierry; Gilby, Krista L; Vinet, Jonathan; Kadam, Shilpa D; Becker, Albert J

    2014-08-01

    New genetic investigation techniques, including next-generation sequencing, epigenetic profiling, cell lineage mapping, targeted genetic manipulation of specific neuronal cell types, stem cell reprogramming, and optogenetic manipulations within epileptic networks are progressively unraveling the mysteries of epileptogenesis and ictogenesis. These techniques have opened new avenues to discover the molecular basis of epileptogenesis and to study the physiologic effects of mutations in epilepsy-associated genes on a multilayer level, from cells to circuits. This manuscript reviews recently published applications of these new genetic technologies in the study of epilepsy, as well as work presented by the authors at the genetic session of the XII Workshop on the Neurobiology of Epilepsy (WONOEP 2013) in Quebec, Canada. Next-generation sequencing is providing investigators with an unbiased means to assess the molecular causes of sporadic forms of epilepsy and has revealed the complexity and genetic heterogeneity of sporadic epilepsy disorders. To assess the functional impact of mutations in these newly identified genes on specific neuronal cell types during brain development, new modeling strategies in animals, including conditional genetics in mice and in utero knock-down approaches, are enabling functional validation with exquisite cell-type and temporal specificity. In addition, optogenetics, using cell-type-specific Cre recombinase driver lines, is enabling investigators to dissect networks involved in epilepsy. In addition, genetically encoded cell-type labeling is providing new means to assess the role of the nonneuronal components of epileptic networks such as glial cells. Furthermore, beyond its role in revealing coding variants involved in epileptogenesis, next-generation sequencing can be used to assess the epigenetic modifications that lead to sustained network hyperexcitability in epilepsy, including methylation changes in gene promoters and noncoding

  1. A rangewide population genetic study of trumpeter swans

    USGS Publications Warehouse

    Oyler-McCance, S.J.; Ransler, F.A.; Berkman, L.K.; Quinn, T.W.

    2007-01-01

    For management purposes, the range of naturally occurring trumpeter swans (Cygnus buccinator) has been divided into two populations, the Pacific Coast Population (PP) and the Rocky Mountain Population (RMP). Little is known about the distribution of genetic variation across the species' range despite increasing pressure to make difficult management decisions regarding the two populations and flocks within them. To address this issue, we used rapidly evolving genetic markers (mitochondrial DNA sequence and 17 nuclear microsatellite loci) to elucidate the underlying genetic structure of the species. Data from both markers revealed a significant difference between the PP and RMP with the Yukon Territory as a likely area of overlap. Additionally, we found that the two populations have somewhat similar levels of genetic diversity (PP is slightly higher) suggesting that the PP underwent a population bottleneck similar to a well-documented one in the RMP. Both genetic structure and diversity results reveal that the Tri-State flock, a suspected unique, non-migratory flock, is not genetically different from the Canadian flock of the RMP and need not be treated as a unique population from a genetic standpoint. Finally, trumpeter swans appear to have much lower mitochondrial DNA variability than other waterfowl studied thus far which may suggest a previous, species-wide bottleneck. ?? 2007 Springer Science+Business Media, Inc.

  2. EEG longitudinal studies in febrile convulsions. Genetic aspects.

    PubMed

    Doose, H; Ritter, K; Völzke, E

    1983-05-01

    It was the purpose of the study to obtain viewpoints on the genetics of febrile convulsions and their relationship to epilepsy by EEG long term follow up. 89 children with febrile convulsions could be followed up to the age of 11 to 13 years (in total 1046 EEG records). The study was concentrated on genetically determined EEG patterns: bilaterally synchronous spikes and waves, photosensitivity and 4-7 cps rhythms. The statistical evaluation was based on standards derived from known strict age dependence of the different patterns. Theta rhythms were found in 54%, spikes and waves of the resting record in 49% and photosensitivity in 42%. In total, genetically determined EEG patterns were found in 81% of the cases which were sufficiently investigated according to given standards. Spikes and waves are strongly age dependent with a maximum at the age of 5-6 years and appear very inconstantly. Theta rhythms and spikes and waves are closely correlated. Spikes and waves are a heterogeneous phenomenon. The type described here must be interpreted as a facultative symptom of the same functional anomaly which forms the basis of 4-7 cps rhythms. The possible pathophysiological basis of the pattern is discussed.--Photosensitivity is interpreted as the symptom of a genetically independent pathogenetic mechanism, which can lead to additive effects by interaction with other genetic abnormalities as well as exogenous factors.--The pathogenesis of febrile convulsions is multifactorial in the strict sense. While the exogenous pathogenetic factors are rather uniform, the genetic predisposition apparently is not. It is based on different genetic anomalies. Each of them is polygenically determined. In the individual case one or different factors can be involved. The genetic predisposition to febrile convulsions is definitely not only polygenic, but of heterogeneous nature. Finally the genetic relationship between febrile convulsions and epilepsy is discussed. PMID:6877532

  3. Recruiting American Indian Women for a Genetic Epidemiology Study

    PubMed Central

    Nadeau, M.; Best, L.

    2010-01-01

    Due to previous negative experiences, some American Indian communities are distrustful of research in general and genetic research in particular. The Turtle Mountain Community College was awarded a National Institutes of Health (NIH) grant with 3 aims: (1) to study possible genetic influences on pre-eclampsia, (2) to encourage tribal college students to consider biomedical careers and (3) to develop the local research infrastructure. Retrospectively identified case (91) and control (188) participants were recruited into Phase I over a 3-year period and additional participants (71) were concurrently recruited from a prenatal clinic into a prospective case/control study, Phase II. This paper describes some of the challenges and solutions we encountered in the process of recruiting American Indian participants into a genetic epidemiologic study. PMID:20616521

  4. WONOEP appraisal: new genetic approaches to study epilepsy

    PubMed Central

    Rossignol, Elsa; Kobow, Katja; Simonato, Michele; Loeb, Jeffrey A.; Grisar, Thierry; Gilby, Krista L.; Vinet, Jonathan; Kadam, Shilpa D.; Becker, Albert J.

    2014-01-01

    Objective New genetic investigation techniques, including next-generation sequencing, epigenetic profiling, cell lineage mapping, targeted genetic manipulation of specific neuronal cell types, stem cell reprogramming and optogenetic manipulations within epileptic networks are progressively unravelling the mysteries of epileptogenesis and ictogenesis. These techniques have opened new avenues to discover the molecular basis of epileptogenesis and to study the physiological impacts of mutations in epilepsy-associated genes on a multilayer level, from cells to circuits. Methods This manuscript reviews recently published applications of these new genetic technologies in the study of epilepsy, as well as work presented by the authors at the genetic session of the XII Workshop on the Neurobiology of Epilepsy in Quebec, Canada. Results Next-generation sequencing is providing investigators with an unbiased means to assess the molecular causes of sporadic forms of epilepsy and have revealed the complexity and genetic heterogeneity of sporadic epilepsy disorders. To assess the functional impact of mutations in these newly identified genes on specific neuronal cell-types during brain development, new modeling strategies in animals, including conditional genetics in mice and in utero knockdown approaches, are enabling functional validation with exquisite cell-type and temporal specificity. In addition, optogenetics, using cell-type specific Cre recombinase driver lines, is enabling investigators to dissect networks involved in epilepsy. Genetically-encoded cell-type labeling is also providing new means to assess the role of the non-neuronal components of epileptic networks such as glial cells. Furthermore, beyond its role in revealing coding variants involved in epileptogenesis, next-generation sequencing can be used to assess the epigenetic modifications that lead to sustained network hyperexcitability in epilepsy, including methylation changes in gene promoters and non

  5. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... individual has a genetic variant associated with hereditary nonpolyposis colorectal cancer is a genetic test... manifested with respect to A. Example 2. (i) Facts. Individual B has several family members with colon cancer... hereditary nonpolyposis colorectal cancer (HNPCC). B's physician, a health care professional with...

  6. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... individual has a genetic variant associated with hereditary nonpolyposis colorectal cancer is a genetic test... manifested with respect to A. Example 2. (i) Facts. Individual B has several family members with colon cancer... hereditary nonpolyposis colorectal cancer (HNPCC). B's physician, a health care professional with...

  7. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... individual has a genetic variant associated with hereditary nonpolyposis colorectal cancer is a genetic test... manifested with respect to A. Example 2. (i) Facts. Individual B has several family members with colon cancer... hereditary nonpolyposis colorectal cancer (HNPCC). B's physician, a health care professional with...

  8. 45 CFR 146.122 - Additional requirements prohibiting discrimination based on genetic information.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... individual has a genetic variant associated with hereditary nonpolyposis colorectal cancer is a genetic test... manifested with respect to A. Example 2. (i) Facts. Individual B has several family members with colon cancer... hereditary nonpolyposis colorectal cancer (HNPCC). B's physician, a health care professional with...

  9. Evidence of Shared Genome-Wide Additive Genetic Effects on Interpersonal Trauma Exposure and Generalized Vulnerability to Drug Dependence in a Population of Substance Users.

    PubMed

    Palmer, Rohan H C; Nugent, Nicole R; Brick, Leslie A; Bidwell, Cinnamon L; McGeary, John E; Keller, Matthew C; Knopik, Valerie S

    2016-06-01

    Exposure to traumatic experiences is associated with an increased risk for drug dependence and poorer response to substance abuse treatment (Claus & Kindleberger, 2002; Jaycox, Ebener, Damesek, & Becker, 2004). Despite this evidence, the reasons for the observed associations of trauma and the general tendency to be dependent upon drugs of abuse remain unclear. Data (N = 2,596) from the Study of Addiction: Genetics and Environment were used to analyze (a) the degree to which commonly occurring single nucleotide polymorphisms (SNPs; minor allele frequency > 1%) in the human genome explains exposure to interpersonal traumatic experiences, and (b) the extent to which additive genetic effects on trauma are shared with additive genetic effects on drug dependence. Our results suggested moderate additive genetic influences on interpersonal trauma, h(2) SNP-Interpersonal = .47, 95% confidence interval (CI) [.10, .85], that are partially shared with additive genetic effects on generalized vulnerability to drug dependence, h(2) SNP-DD = .36, 95% CI [.11, .61]; rG-SNP = .49, 95% CI [.02, .96]. Although the design/technique does not exclude the possibility that substance abuse causally increases risk for traumatic experiences (or vice versa), these findings raise the possibility that commonly occurring SNPs influence both the general tendency towards drug dependence and interpersonal trauma. PMID:27214850

  10. Efficient Markov Chain Monte Carlo Implementation of Bayesian Analysis of Additive and Dominance Genetic Variances in Noninbred Pedigrees

    PubMed Central

    Waldmann, Patrik; Hallander, Jon; Hoti, Fabian; Sillanpää, Mikko J.

    2008-01-01

    Accurate and fast computation of quantitative genetic variance parameters is of great importance in both natural and breeding populations. For experimental designs with complex relationship structures it can be important to include both additive and dominance variance components in the statistical model. In this study, we introduce a Bayesian Gibbs sampling approach for estimation of additive and dominance genetic variances in the traditional infinitesimal model. The method can handle general pedigrees without inbreeding. To optimize between computational time and good mixing of the Markov chain Monte Carlo (MCMC) chains, we used a hybrid Gibbs sampler that combines a single site and a blocked Gibbs sampler. The speed of the hybrid sampler and the mixing of the single-site sampler were further improved by the use of pretransformed variables. Two traits (height and trunk diameter) from a previously published diallel progeny test of Scots pine (Pinus sylvestris L.) and two large simulated data sets with different levels of dominance variance were analyzed. We also performed Bayesian model comparison on the basis of the posterior predictive loss approach. Results showed that models with both additive and dominance components had the best fit for both height and diameter and for the simulated data with high dominance. For the simulated data with low dominance, we needed an informative prior to avoid the dominance variance component becoming overestimated. The narrow-sense heritability estimates in the Scots pine data were lower compared to the earlier results, which is not surprising because the level of dominance variance was rather high, especially for diameter. In general, the hybrid sampler was considerably faster than the blocked sampler and displayed better mixing properties than the single-site sampler. PMID:18558655

  11. Efficient Markov chain Monte Carlo implementation of Bayesian analysis of additive and dominance genetic variances in noninbred pedigrees.

    PubMed

    Waldmann, Patrik; Hallander, Jon; Hoti, Fabian; Sillanpää, Mikko J

    2008-06-01

    Accurate and fast computation of quantitative genetic variance parameters is of great importance in both natural and breeding populations. For experimental designs with complex relationship structures it can be important to include both additive and dominance variance components in the statistical model. In this study, we introduce a Bayesian Gibbs sampling approach for estimation of additive and dominance genetic variances in the traditional infinitesimal model. The method can handle general pedigrees without inbreeding. To optimize between computational time and good mixing of the Markov chain Monte Carlo (MCMC) chains, we used a hybrid Gibbs sampler that combines a single site and a blocked Gibbs sampler. The speed of the hybrid sampler and the mixing of the single-site sampler were further improved by the use of pretransformed variables. Two traits (height and trunk diameter) from a previously published diallel progeny test of Scots pine (Pinus sylvestris L.) and two large simulated data sets with different levels of dominance variance were analyzed. We also performed Bayesian model comparison on the basis of the posterior predictive loss approach. Results showed that models with both additive and dominance components had the best fit for both height and diameter and for the simulated data with high dominance. For the simulated data with low dominance, we needed an informative prior to avoid the dominance variance component becoming overestimated. The narrow-sense heritability estimates in the Scots pine data were lower compared to the earlier results, which is not surprising because the level of dominance variance was rather high, especially for diameter. In general, the hybrid sampler was considerably faster than the blocked sampler and displayed better mixing properties than the single-site sampler. PMID:18558655

  12. Additional Treatments Offer Little Benefit for Pancreatic Cancer: Study

    MedlinePlus

    ... 158633.html Additional Treatments Offer Little Benefit for Pancreatic Cancer: Study Neither extra chemotherapy drug nor add-on ... 2016 (HealthDay News) -- Additional treatments for locally advanced pancreatic cancer don't appear to boost survival, a new ...

  13. Antenatal genetic studies in twin pregnancies.

    PubMed

    Redwine, F O; Cruikshank, D P; Brown, J

    1984-01-01

    The diagnosis of multiple gestation at the time of genetic amniocentesis is a routine occurrence. In a combined series of 2765 patients referred for antenatal genetic studies from the Medical College of Virginia and the University of Iowa, 34 twin pregnancies were encountered (1.2%). Twenty-six of the patients with twins were referred for advanced maternal age. The other indications were previous neural tube defects (1), previous trisomy 21 (2), known carriers of Tay Sachs disease (2), previous Turner's syndrome (1), family history of trisomy 21 (1), and one pregnancy was referred because of an abnormal ultrasound. Amniocentesis procedures, outcome of the twin pregnancies, and genetic counseling issues, are discussed. PMID:6741416

  14. Genetic studies in the Amish community.

    PubMed

    Patton, Michael A

    2005-01-01

    The Amish community was established in Pennsylvania, Ohio and Indiana. They form a distinct and biologically isolated community by virtue of their strong cultural and religious beliefs. This paper outlines aspects of the Amish culture and reviews some of the recent genetic studies that have been undertaken in this community. PMID:16096212

  15. Selection for increased desiccation resistance in Drosophila melanogaster: Additive genetic control and correlated responses for other stresses

    SciTech Connect

    Hoffmann, A.A.; Parsons, P.A. )

    1989-08-01

    Previously we found that Drosophila melanogaster lines selected for increased desiccation resistance have lowered metabolic rate and behavioral activity levels, and show correlated responses for resistance to starvation and a toxic ethanol level. These results were consistent with a prediction that increased resistance to many environmental stresses may be genetically correlated because of a reduction in metabolic energy expenditure. Here we present experiments on the genetic basis of the selection response and extend the study of correlated responses to other stresses. The response to selection was not sex-specific and involved X-linked and autosomal genes acting additively. Activity differences contributed little to differences in desiccation resistance between selected and control lines. Selected lines had lower metabolic rates than controls in darkness when activity was inhibited. Adults from selected lines showed increased resistance to a heat shock, {sup 60}Co-gamma-radiation, and acute ethanol and acetic acid stress. The desiccation, ethanol and starvation resistance of isofemale lines set up from the F2s of a cross between one of the selected and one of the control lines were correlated. Selected and control lines did not differ in ether-extractable lipid content or in resistance to acetone, ether or a cold shock.

  16. Presymptomatic studies in genetic frontotemporal dementia.

    PubMed

    Rohrer, J D; Warren, J D; Fox, N C; Rossor, M N

    2013-10-01

    Approximately 20% of patients with the neurodegenerative disorder frontotemporal dementia (FTD) have an autosomal dominant pattern of inheritance. Genetic FTD is caused by mutations in three genes in most cases (progranulin, microtubule-associated protein tau and chromosome 9 open reading frame 72) although a number of other genes are rare causes. Studies of other neurodegenerative diseases have shown imaging and biomarker evidence of disease onset many years prior to the development of symptoms. Similar studies in genetic FTD are now revealing evidence of a series of presymptomatic changes, initially in plasma biomarkers followed by MR imaging abnormalities of functional and structural connectivity and then grey matter atrophy. Lastly, neuropsychometric tests become abnormal in proximity to the onset of symptoms. Such studies have been relatively small until now but research centres with an expertise in genetic FTD are now forming consortia such as the Genetic Frontotemporal Dementia Initiative (GenFI) to create larger cohorts that can form the basis of future clinical trials. PMID:24012408

  17. Additional records of metazoan parasites from Caribbean marine mammals, including genetically identified anisakid nematodes.

    PubMed

    Colón-Llavina, Marlene M; Mignucci-Giannoni, Antonio A; Mattiucci, Simonetta; Paoletti, Michela; Nascetti, Giuseppe; Williams, Ernest H

    2009-10-01

    Studies of marine mammal parasites in the Caribbean are scarce. An assessment for marine mammal endo- and ectoparasites from Puerto Rico and the Virgin Islands, but extending to other areas of the Caribbean, was conducted between 1989 and 1994. The present study complements the latter and enhances identification of anisakid nematodes using molecular markers. Parasites were collected from 59 carcasses of stranded cetaceans and manatees from 1994 to 2006, including Globicephala macrorhynchus, Kogia breviceps, Kogia sima, Lagenodelphis hosei, Mesoplodon densirostris, Peponocephala electra, Stenella longirostris, Steno bredanensis, Trichechus manatus. Tursiops truncatus, and Ziphius cavirostris. Sixteen species of endoparasitic helminthes were morphologically identified, including two species of acanthocephalans (Bolbosoma capitatum, Bolbosoma vasculosum), nine species of nematodes (Anisakis sp., Anisakis brevispiculata, Anisakis paggiae, Anisakis simplex, Anisakis typica, Anisakis ziphidarium, Crassicauda anthonyi, Heterocheilus tunicatus, Pseudoterranova ceticola), two species of cestodes (Monorygma grimaldi, Phyllobothrium delphini), and three species of trematodes (Chiorchis groschafti, Pulmonicola cochleotrema, Monoligerum blairi). The nematodes belonging to the genus Anisakis recovered in some stranded animals were genetically identified to species level based on their sequence analysis of mitochondrial DNA (629 bp of mtDNA cox 2). A total of five new host records and six new geographic records are presented. PMID:19582477

  18. The modified ultrasound pattern sum score mUPSS as additional diagnostic tool for genetically distinct hereditary neuropathies.

    PubMed

    Grimm, Alexander; Rasenack, Maria; Athanasopoulou, Ioanna M; Dammeier, Nele Maria; Lipski, Christina; Wolking, Stefan; Vittore, Debora; Décard, Bernhard F; Axer, Hubertus

    2016-02-01

    The objective of this study is to evaluate the nerve ultrasound characteristics in genetically distinct inherited neuropathies, the value of the modified ultrasound pattern sum score (mUPSS) to differentiate between the subtypes and the correlation of ultrasound with nerve conduction studies (NCS), disease duration and severity. All patients underwent a standardized neurological examination, ultrasound, and NCS. In addition, genetic testing was performed. Consequently, mUPSS was applied, which is a sum-score of cross-sectional areas (CSA) at predefined anatomical points in different nerves. 31 patients were included (10xCharcot-Marie-Tooth (CMT)1a, 3xCMT1b, 3xCMTX, 9xCMT2, 6xHNPP [Hereditary neuropathy with liability to pressure palsies]). Generalized, homogeneous nerve enlargement and significantly increased UPS scores emphasized the diagnosis of demyelinating neuropathy, particularly CMT1a and CMT1b. The amount of enlargement did not depend on disease duration, symptom severity, height and weight. In CMTX the nerves were enlarged, as well, however, only in the roots and lower limbs, most prominent in men. In CMT2 no significant enlargement was detectable. In HNPP the CSA values were increased at entrapped sites, and not elsewhere. However, a distinction from CMT1, which also showed enlarged CSA values at entrapment sites, was only possible by calculating the entrapment ratios and entrapment score. The mUPSS allowed distinction between CMT1a (increased UPS scores, entrapment ratios <1.0) and HNPP (low UPS scores, entrapment ratios >1.4), while CMT1b and CMTX showed intermediate UPS types and entrapment ratios <1.0. Although based on few cases, ultrasound revealed consistent and homogeneous nerve alteration in certain inherited neuropathies. The modified UPSS is a quantitative tool, which may provide useful information for diagnosis, differentiation and follow-up evaluation in addition to NCS and molecular testing. PMID:26559821

  19. Genetic variation and prediction of additive and nonadditive genetic effects for six carcass traits in an Angus-Brahman multibreed herd.

    PubMed

    Elzo, M A; West, R L; Johnson, D D; Wakeman, D L

    1998-07-01

    Estimates of covariances and sire expected progeny differences of additive and nonadditive genetic effects for six carcass traits were obtained using records from 486 straightbred and crossbred steers from 121 sires born between 1989 and 1995 in the Angus-Brahman multibreed herd of the University of Florida. Steers were slaughtered at a similar carcass composition end point. Covariances were estimated by REML procedures, using a generalized expectation-maximization algorithm applied to multibreed populations. Straightbred and crossbred estimates of heritabilities and additive genetic correlations were within ranges found in the literature for steers slaughtered on an age- or weight-constant basis for hot carcass weight, longissimus muscle area, and shear force but equal to or less than the lower bound of these ranges for fat-related traits. Maximum values of interactibilities (i.e., ratios of nonadditive variances to phenotypic variances in the F1) and nonadditive genetic correlations were smaller than heritabilities and additive genetic correlations in straightbreds and crossbred groups. Sire additive and total direct genetic predictions for longissimus muscle area, marbling, and shear force tended to decrease with the fraction of Brahman alleles, whereas those for hot carcass weight and fat thickness over the longissimus were higher, and those for kidney fat were lower in straightbreds and F1 than in other crossbred groups. Nonadditive genetic predictions were similar across sire groups of all Angus and Brahman fractions. These results suggest that slaughtering steers on a similar carcass composition basis reduces variability of fat-related traits while retaining variability for non-fat-related traits comparable to slaughtering steers on a similar age or weight basis. Selection for carcass traits within desirable (narrow) ranges and slaughter of steers at similar compositional end point seems to be a good combination to help produce meat products of consistent

  20. Factor analysis models for structuring covariance matrices of additive genetic effects: a Bayesian implementation

    PubMed Central

    de los Campos, Gustavo; Gianola, Daniel

    2007-01-01

    Multivariate linear models are increasingly important in quantitative genetics. In high dimensional specifications, factor analysis (FA) may provide an avenue for structuring (co)variance matrices, thus reducing the number of parameters needed for describing (co)dispersion. We describe how FA can be used to model genetic effects in the context of a multivariate linear mixed model. An orthogonal common factor structure is used to model genetic effects under Gaussian assumption, so that the marginal likelihood is multivariate normal with a structured genetic (co)variance matrix. Under standard prior assumptions, all fully conditional distributions have closed form, and samples from the joint posterior distribution can be obtained via Gibbs sampling. The model and the algorithm developed for its Bayesian implementation were used to describe five repeated records of milk yield in dairy cattle, and a one common FA model was compared with a standard multiple trait model. The Bayesian Information Criterion favored the FA model. PMID:17897592

  1. A Study of Additional Costs of Second Language Instruction.

    ERIC Educational Resources Information Center

    McEwen, Nelly

    A study was conducted whose primary aim was to identify and explain additional costs incurred by Alberta, Canada school jurisdictions providing second language instruction in 1980. Additional costs were defined as those which would not have been incurred had the second language program not been in existence. Three types of additional costs were…

  2. The Multi-allelic Genetic Architecture of a Variance-Heterogeneity Locus for Molybdenum Concentration in Leaves Acts as a Source of Unexplained Additive Genetic Variance

    PubMed Central

    Forsberg, Simon K. G.; Andreatta, Matthew E.; Huang, Xin-Yuan; Danku, John; Salt, David E.; Carlborg, Örjan

    2015-01-01

    Genome-wide association (GWA) analyses have generally been used to detect individual loci contributing to the phenotypic diversity in a population by the effects of these loci on the trait mean. More rarely, loci have also been detected based on variance differences between genotypes. Several hypotheses have been proposed to explain the possible genetic mechanisms leading to such variance signals. However, little is known about what causes these signals, or whether this genetic variance-heterogeneity reflects mechanisms of importance in natural populations. Previously, we identified a variance-heterogeneity GWA (vGWA) signal for leaf molybdenum concentrations in Arabidopsis thaliana. Here, fine-mapping of this association reveals that the vGWA emerges from the effects of three independent genetic polymorphisms that all are in strong LD with the markers displaying the genetic variance-heterogeneity. By revealing the genetic architecture underlying this vGWA signal, we uncovered the molecular source of a significant amount of hidden additive genetic variation or “missing heritability”. Two of the three polymorphisms underlying the genetic variance-heterogeneity are promoter variants for Molybdate transporter 1 (MOT1), and the third a variant located ~25 kb downstream of this gene. A fourth independent association was also detected ~600 kb upstream of MOT1. Use of a T-DNA knockout allele highlights Copper Transporter 6; COPT6 (AT2G26975) as a strong candidate gene for this association. Our results show that an extended LD across a complex locus including multiple functional alleles can lead to a variance-heterogeneity between genotypes in natural populations. Further, they provide novel insights into the genetic regulation of ion homeostasis in A. thaliana, and empirically confirm that variance-heterogeneity based GWA methods are a valuable tool to detect novel associations of biological importance in natural populations. PMID:26599497

  3. Consortium-Based Genetic Studies of Kawasaki Disease in Korea: Korean Kawasaki Disease Genetics Consortium

    PubMed Central

    Hong, Young Mi; Jang, Gi Young; Yun, Sin Weon; Yu, Jeong Jin; Yoon, Kyung Lim; Lee, Kyung-Yil; Kil, Hong-Rang

    2015-01-01

    In order to perform large-scale genetic studies of Kawasaki disease (KD) in Korea, the Korean Kawasaki Disease Genetics Consortium (KKDGC) was formed in 2008 with 10 hospitals. Since the establishment of KKDGC, there has been a collection of clinical data from a total of 1198 patients, and approximately 5 mL of blood samples per patient (for genomic deoxyribonucleic acid and plasma isolation), using a standard clinical data collection form and a nation-wide networking system for blood sample pick-up. In the clinical risk factor analysis using the collected clinical data of 478 KD patients, it was found that incomplete KD type, intravenous immunoglobulin (IVIG) non-responsiveness, and long febrile days are major risk factors for coronary artery lesions development, whereas low serum albumin concentration is an independent risk factor for IVIG non-responsiveness. In addition, we identified a KD susceptibility locus at 1p31, a coronary artery aneurysm locus (KCNN2 gene), and the causal variant in the C-reactive protein (CRP) promoter region, as determining the increased CRP levels in KD patients, by means of genome-wide association studies. Currently, this consortium is continually collecting more clinical data and genomic samples to identify the clinical and genetic risk factors via a single nucleotide polymorphism chip and exome sequencing, as well as collaborating with several international KD genetics teams. The consortium-based approach for genetic studies of KD in Korea will be a very effective way to understand the unknown etiology and causal mechanism of KD, which may be affected by multiple genes and environmental factors. PMID:26617644

  4. 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.

  5. The OCD collaborative genetics study: methods and sample description.

    PubMed

    Samuels, Jack F; Riddle, Mark A; Greenberg, Benjamin D; Fyer, Abby J; McCracken, James T; Rauch, Scott L; Murphy, Dennis L; Grados, Marco A; Pinto, Anthony; Knowles, James A; Piacentini, John; Cannistraro, Paul A; Cullen, Bernadette; Bienvenu, O Joseph; Rasmussen, Steven A; Pauls, David L; Willour, Virginia L; Shugart, Yin Y; Liang, Kung-yee; Hoehn-Saric, Rudolf; Nestadt, Gerald

    2006-04-01

    Results from twin and family studies suggest that obsessive-compulsive disorder (OCD) may be transmitted in families but, to date, genes for the disorder have not been identified. The OCD Collaborative Genetics Study (OCGS) is a six-site collaborative genetic linkage study of OCD. Specimens and blinded clinical data will be made available through the National Institute of Mental Health (NIMH) cell repository. In this initial report, we describe the methods of the study and present clinical characteristics of affected individuals for researchers interested in this valuable resource for genetic studies of OCD. The project clinically evaluated and collected blood specimens from 238 families containing 299 OCD-affected sibling pairs and their parents, and additional affected relative pairs, for a genome-wide linkage study. Of the 999 individuals interviewed to date, 624 were diagnosed with "definite" OCD. The mean age of subjects was 36 years (range 7-95). The majority of affected individuals (66%) were female. The mean age at onset of obsessive-compulsive symptoms was 9.5 years. Specific mood disorders, anxiety disorders, eating disorders, and skin picking were more prevalent in female cases, whereas tics, Tourette disorder, and alcohol dependence were more prevalent in male cases. Compared to "definite" cases of OCD, "probable" cases (n = 82) had, on average, later age at onset of obsessive-compulsive symptoms, lower severity score, and fewer numbers of different categories of obsessions and compulsions, and they were less likely to have received treatment for their symptoms. PMID:16511842

  6. Genetic and environmental influences on impulsivity: A meta-analysis of twin, family and adoption studies

    PubMed Central

    Bezdjian, Serena; Baker, Laura A.; Tuvblad, Catherine

    2011-01-01

    A meta-analysis of twin, family and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on impulsivity. The best fitting model for 41 key studies (58 independent samples from 14 month old infants to adults; N = 27,147) included equal proportions of variance due to genetic (0.50) and non-shared environmental (0.50) influences, with genetic effects being both additive (0.38) and non-additive (0.12). Shared environmental effects were unimportant in explaining individual differences in impulsivity. Age, sex, and study design (twin vs. adoption) were all significant moderators of the magnitude of genetic and environmental influences on impulsivity. The relative contribution of genetic effects (broad sense heritability) and unique environmental effects were also found to be important throughout development from childhood to adulthood. Total genetic effects were found to be important for all ages, but appeared to be strongest in children. Analyses also demonstrated that genetic effects appeared to be stronger in males than in females. Method of assessment (laboratory tasks vs. questionnaires), however, was not a significant moderator of the genetic and environmental influences on impulsivity. These results provide a structured synthesis of existing behavior genetic studies on impulsivity by providing a clearer understanding of the relative genetic and environmental contributions in impulsive traits through various stages of development. PMID:21889436

  7. A pathway-based analysis provides additional support for an immune-related genetic susceptibility to Parkinson's disease

    PubMed Central

    Holmans, Peter; Moskvina, Valentina; Jones, Lesley; Sharma, Manu; Vedernikov, Alexey; Buchel, Finja; Sadd, Mohamad; Bras, Jose M.; Bettella, Francesco; Nicolaou, Nayia; Simón-Sánchez, Javier; Mittag, Florian; Gibbs, J. Raphael; Schulte, Claudia; Durr, Alexandra; Guerreiro, Rita; Hernandez, Dena; Brice, Alexis; Stefánsson, Hreinn; Majamaa, Kari; Gasser, Thomas; Heutink, Peter; Wood, Nicholas W.; Martinez, Maria; Singleton, Andrew B.; Nalls, Michael A.; Hardy, John; Morris, Huw R.; Williams, Nigel M.; Arepalli, Sampath; Barker, Roger; Barrett, Jeffrey; Ben-Shlomo, Yoav; Berendse, Henk W.; Berg, Daniela; Bhatia, Kailash; de Bie, Rob M.A.; Biffi, Alessandro; Bloem, Bas; Brice, Alexis; Bochdanovits, Zoltan; Bonin, Michael; Bras, Jose M.; Brockmann, Kathrin; Brooks, Janet; Burn, David J.; Charlesworth, Gavin; Chen, Honglei; Chinnery, Patrick F.; Chong, Sean; Clarke, Carl E.; Cookson, Mark R.; Cooper, Jonathan M.; Corvol, Jen-Christophe; Counsell, Carl; Damier, Philippe; Dartigues, Jean Francois; Deloukas, Panagiotis; Deuschl, Günther; Dexter, David T.; van Dijk, Karin D.; Dillman, Allissa; Durif, Frank; Durr, Alexandra; Edkins, Sarah; Evans, Jonathan R.; Foltynie, Thomas; Gao, Jianjun; Gardner, Michelle; Gasser, Thomas; Gibbs, J. Raphael; Goate, Alison; Gray, Emma; Guerreiro, Rita; Gústafsson, Ómar; Hardy, John; Harris, Clare; Hernandez, Dena G.; Heutink, Peter; van Hilten, Jacobus J.; Hofman, Albert; Hollenbeck, Albert; Holmans, Peter; Holton, Janice; Hu, Michele; Huber, Heiko; Hudson, Gavin; Hunt, Sarah E.; Huttenlocher, Johanna; Illig, Thomas; Langford, Cordelia; Lees, Andrew; Lesage, Suzanne; Lichtner, Peter; Limousin, Patricia; Lopez, Grisel; Lorenz, Delia; Martinez, Maria; McNeill, Alisdair; Moorby, Catriona; Moore, Matthew; Morris, Huw; Morrison, Karen E.; Moskvina, Valentina; Mudanohwo, Ese; Nalls, Michael A.; Pearson, Justin; Perlmutter, Joel S.; Pétursson, Hjörvar; Plagnol, Vincent; Pollak, Pierre; Post, Bart; Potter, Simon; Ravina, Bernard; Revesz, Tamas; Riess, Olaf; Rivadeneira, Fernando; Rizzu, Patrizia; Ryten, Mina; Saad, Mohamad; Sawcer, Stephen; Schapira, Anthony; Scheffer, Hans; Sharma, Manu; Shaw, Karen; Sheerin, Una-Marie; Shoulson, Ira; Schulte, Claudia; Sidransky, Ellen; Simón-Sánchez, Javier; Singleton, Andrew B.; Smith, Colin; Stefánsson, Hreinn; Stefánsson, Kári; Steinberg, Stacy; Stockton, Joanna D.; Sveinbjornsdottir, Sigurlaug; Talbot, Kevin; Tanner, Carlie M.; Tashakkori-Ghanbaria, Avazeh; Tison, François; Trabzuni, Daniah; Traynor, Bryan J.; Uitterlinden, André G.; Velseboer, Daan; Vidailhet, Marie; Walker, Robert; van de Warrenburg, Bart; Wickremaratchi, Mirdhu; Williams, Nigel; Williams-Gray, Caroline H.; Winder-Rhodes, Sophie; Wood, Nicholas

    2013-01-01

    Parkinson's disease (PD) is the second most common neurodegenerative disease affecting 1–2% in people >60 and 3–4% in people >80. Genome-wide association (GWA) studies have now implicated significant evidence for association in at least 18 genomic regions. We have studied a large PD-meta analysis and identified a significant excess of SNPs (P < 1 × 10−16) that are associated with PD but fall short of the genome-wide significance threshold. This result was independent of variants at the 18 previously implicated regions and implies the presence of additional polygenic risk alleles. To understand how these loci increase risk of PD, we applied a pathway-based analysis, testing for biological functions that were significantly enriched for genes containing variants associated with PD. Analysing two independent GWA studies, we identified that both had a significant excess in the number of functional categories enriched for PD-associated genes (minimum P = 0.014 and P = 0.006, respectively). Moreover, 58 categories were significantly enriched for associated genes in both GWA studies (P < 0.001), implicating genes involved in the ‘regulation of leucocyte/lymphocyte activity’ and also ‘cytokine-mediated signalling’ as conferring an increased susceptibility to PD. These results were unaltered by the exclusion of all 178 genes that were present at the 18 genomic regions previously reported to be strongly associated with PD (including the HLA locus). Our findings, therefore, provide independent support to the strong association signal at the HLA locus and imply that the immune-related genetic susceptibility to PD is likely to be more widespread in the genome than previously appreciated. PMID:23223016

  8. Influence of a Dopamine Pathway Additive Genetic Efficacy Score on Smoking Cessation: Results from Two Randomized Clinical Trials of Bupropion

    PubMed Central

    David, Sean P.; Strong, David R.; Leventhal, Adam M.; Lancaster, Molly A.; McGeary, John E.; Munafò, Marcus R.; Bergen, Andrew W.; Swan, Gary E.; Benowitz, Neal L.; Tyndale, Rachel F.; Conti, David V.; Brown, Richard A.; Lerman, Caryn; Niaura, Raymond

    2013-01-01

    Aims To evaluate associations of treatment and an ‘additive genetic efficacy score’ (AGES) based on dopamine functional polymorphisms with time to first smoking lapse and point prevalence abstinence at end of treatment among participants enrolled in two randomized clinical trials of smoking cessation therapies. Design Double-blind pharmacogenetic efficacy trials randomizing participants to active or placebo bupropion. Study 1 also randomized participants to cognitive-behavioral smoking cessation treatment (CBT) or this treatment with CBT for depression. Study 2 provided standardized behavioural support. Setting Two Hospital-affiliated clinics (Study 1), and two University-affiliated clinics (Study 2). Participants N=792 self-identified white treatment-seeking smokers aged ≥18 years smoking ≥10 cigarettes per day over the last year. Measurements Age, gender, Fagerström Test for Nicotine Dependence, dopamine pathway genotypes (rs1800497 [ANKK1 E713K], rs4680 [COMT V158M], DRD4 exon 3 Variable Number of Tandem Repeats polymorphism [DRD4 VNTR], SLC6A3 3' VNTR) analyzed both separately and as part of an AGES, time to first lapse, and point prevalence abstinence at end of treatment. Findings Significant associations of the AGES (hazard ratio = 1.10, 95% Confidence Interval [CI] = 1.06–1.14], p=0.0099) and of the DRD4 VNTR (HR = 1.29, 95%CI 1.17–1.41, p=0.0073) were observed with time to first lapse. A significant AGES by pharmacotherapy interaction was observed (β [SE]=−0.18 [0.07], p=0.016), such that AGES predicted risk for time to first lapse only for individuals randomized to placebo. Conclusions A score based on functional polymorphisms relating to dopamine pathways appears to predict lapse to smoking following a quit attempt, and the association is mitigated in smokers using bupropion. PMID:23941313

  9. Combining genetic association study designs: a GWAS case study.

    PubMed

    Estus, Janice L; Fardo, David W

    2013-01-01

    Genome-wide association studies (GWAS) explore the relationship between genome variability and disease susceptibility with either population- or family-based data. Here, we have evaluated the utility of combining population- and family-based statistical association tests and have proposed a method for reducing the burden of multiple testing. Unrelated singleton and parent-offspring trio cases and controls from the Genetics of Kidneys in Diabetes (GoKinD) study were analyzed for genetic association with diabetic nephropathy (DN) in type 1 diabetics (T1D). The Cochran-Armitage test for trend and the family-based association test were employed using either unrelated cases and controls or trios, respectively. In addition to combining single nucleotide polymorphism (SNP) p-values across these tests via Fisher's method, we employed a novel screening approach to rank SNPs based on conditional power for more efficient testing. Using either the population-based or family-based subset alone predictably limited resolution to detect DN SNPs. For 384,197 SNPs passing quality control (QC), none achieved strict genome-wide significance (1.4 × 10(-7)) using 1171 singletons (577/594 cases/controls) or 1738 pooled singletons and offspring probands (841/897). Similarly, none of the 352,004 SNPs passing QC in 567 family trios (264/303 case/control proband trios) reached genome-wide significance. Testing the top 10 SNPs ranked using aggregated conditional power resulted in two SNPs reaching genome-wide significance, rs11645147 on chromosome 16 (p = 1.74 × 10(-4) < 0.05/10 = 0.005) and rs7866522 on chromosome 9 (p = 0.0033). Efficient usage of mixed designs incorporating both unrelated and family-based data may help to uncover associations otherwise difficult to detect in the presence of massive multiple testing corrections. Capitalizing on the strengths of both types while using screening approaches may be useful especially in light of large-scale, next-generation sequencing and rare

  10. Genetic and environmental influences on antisocial behavior: a meta-analysis of twin and adoption studies.

    PubMed

    Rhee, Soo Hyun; Waldman, Irwin D

    2002-05-01

    A meta-analysis of 51 twin and adoption studies was conducted to estimate the magnitude of genetic and environmental influences on antisocial behavior. The best fitting model included moderate proportions of variance due to additive genetic influences (.32), nonadditive genetic influences (.09), shared environmental influences (.16), and nonshared environmental influences (.43). The magnitude of familial influences (i.e., both genetic and shared environmental influences) was lower in parent-offspring adoption studies than in both twin studies and sibling adoption studies. Operationalization, assessment method, zygosity determination method, and age were significant moderators of the magnitude of genetic and environmental influences on antisocial behavior, but there were no significant differences in the magnitude of genetic and environmental influences for males and females. PMID:12002699

  11. Complete nucleotide sequence of a Spanish isolate of alfalfa mosaic virus: evidence for additional genetic variability.

    PubMed

    Parrella, Giuseppe; Acanfora, Nadia; Orílio, Anelise F; Navas-Castillo, Jesús

    2011-06-01

    Alfalfa mosaic virus (AMV) is a plant virus that is distributed worldwide and can induce necrosis and/or yellow mosaic on a large variety of plant species, including commercially important crops. It is the only virus of the genus Alfamovirus in the family Bromoviridae. AMV isolates can be clustered into two genetic groups that correlate with their geographic origin. Here, we report for the first time the complete nucleotide sequence of a Spanish isolate of AMV found infecting Cape honeysuckle (Tecoma capensis) and named Tec-1. The tripartite genome of Tec-1 is composed of 3643 nucleotides (nt) for RNA1, 2594 nt for RNA2 and 2037 nt for RNA3. Comparative sequence analysis of the coat protein gene revealed that the isolate Tec-1 is distantly related to subgroup I of AMV and more closely related to subgroup II, although forming a distinct phylogenetic clade. Therefore, we propose to split subgroup II of AMV into two subgroups, namely IIA, comprising isolates previously included in subgroup II, and IIB, including the novel Spanish isolate Tec-1. PMID:21327783

  12. A generalized approach and computer tool for quantitative genetics study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quantitative genetics is one of the most important components to provide valuable genetic information for improving production and quality of plants and animals. The research history of quantitative genetics study could be traced back more than one hundred years. Since the Analysis of Variance (ANOV...

  13. Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genus Capsicum represents one of several well characterized Solanaceous genera. A wealth of classical and molecular genetics research is available for the genus. Information gleaned from its cultivated relatives, tomato and potato, provide further insight for basic and applied studies. Early ...

  14. Evolutionary genetics in wild primates: combining genetic approaches with field studies of natural populations

    PubMed Central

    Tung, Jenny; Alberts, Susan C; Wray, Gregory A

    2010-01-01

    Ecological and evolutionary studies of wild primates hold important keys to understanding both the shared characteristics of primate biology and the genetic and phenotypic differences that make specific lineages, including our own, unique. Although complementary genetic research on nonhuman primates has long been of interest, recent technological and methodological advances now enable functional and population genetic studies in an unprecedented manner. In the past several years, novel genetic data sets have revealed new information about the demographic history of primate populations and the genetics of adaptively important traits. In combination with the rich history of behavioral, ecological, and physiological work on natural primate populations, genetic approaches promise to provide a compelling picture of primate evolution in the past and in the present day. PMID:20580115

  15. Electrostatic Levitation for Studies of Additive Manufactured Materials

    NASA Technical Reports Server (NTRS)

    SanSoucie, Michael P.; Rogers, Jan R.; Tramel, Terri

    2014-01-01

    The electrostatic levitation (ESL) laboratory at NASA's Marshall Space Flight Center is a unique facility for investigators studying high temperature materials. The laboratory boasts two levitators in which samples can be levitated, heated, melted, undercooled, and resolidified. Electrostatic levitation minimizes gravitational effects and allows materials to be studied without contact with a container or instrumentation. The lab also has a high temperature emissivity measurement system, which provides normal spectral and normal total emissivity measurements at use temperature. The ESL lab has been instrumental in many pioneering materials investigations of thermophysical properties, e.g., creep measurements, solidification, triggered nucleation, and emissivity at high temperatures. Research in the ESL lab has already led to the development of advanced high temperature materials for aerospace applications, coatings for rocket nozzles, improved medical and industrial optics, metallic glasses, ablatives for reentry vehicles, and materials with memory. Modeling of additive manufacturing materials processing is necessary for the study of their resulting materials properties. In addition, the modeling of the selective laser melting processes and its materials property predictions are also underway. Unfortunately, there is very little data for the properties of these materials, especially of the materials in the liquid state. Some method to measure thermophysical properties of additive manufacturing materials is necessary. The ESL lab is ideal for these studies. The lab can provide surface tension and viscosity of molten materials, density measurements, emissivity measurements, and even creep strength measurements. The ESL lab can also determine melting temperature, surface temperatures, and phase transition temperatures of additive manufactured materials. This presentation will provide background on the ESL lab and its capabilities, provide an approach to using the ESL

  16. Additive genetic variation in resistance traits of an exotic pine species: little evidence for constraints on evolution of resistance against native herbivores

    PubMed Central

    Moreira, X; Zas, R; Sampedro, L

    2013-01-01

    The apparent failure of invasions by alien pines in Europe has been explained by the co-occurrence of native pine congeners supporting herbivores that might easily recognize the new plants as hosts. Previous studies have reported that exotic pines show reduced tolerance and capacity to induce resistance to those native herbivores. We hypothesize that limited genetic variation in resistance to native herbivores and the existence of evolutionary trade-offs between growth and resistance could represent additional potential constraints on the evolution of invasiveness of exotic pines outside their natural range. In this paper, we examined genetic variation for constitutive and induced chemical defences (measured as non-volatile resin in the stem and total phenolics in the needles) and resistance to two major native generalist herbivores of pines in cafeteria bioassays (the phloem-feeder Hylobius abietis and the defoliator Thaumetopoea pityocampa) using half-sib families drawn from a sample of the population of Pinus radiata introduced to Spain in the mid-19th century. We found (i) significant genetic variation, with moderate-to-high narrow-sense heritabilities for both the production of constitutive non-volatile resin and induced total phenolics, and for constitutive resistance against T. pityocampa in bioassays, (ii) no evolutionary trade-offs between plant resistance and growth traits or between the production of different quantitative chemical defences and (iii) a positive genetic correlation between constitutive resistance to the two studied herbivores. Overall, results of our study indicate that the exotic pine P. radiata has limited genetic constraints on the evolution of resistance against herbivores in its introduced range, suggesting that, at least in terms of interactions with these enemies, this pine species has potential to become invasive in the future. PMID:23232833

  17. Additive genetic variation in resistance traits of an exotic pine species: little evidence for constraints on evolution of resistance against native herbivores.

    PubMed

    Moreira, X; Zas, R; Sampedro, L

    2013-05-01

    The apparent failure of invasions by alien pines in Europe has been explained by the co-occurrence of native pine congeners supporting herbivores that might easily recognize the new plants as hosts. Previous studies have reported that exotic pines show reduced tolerance and capacity to induce resistance to those native herbivores. We hypothesize that limited genetic variation in resistance to native herbivores and the existence of evolutionary trade-offs between growth and resistance could represent additional potential constraints on the evolution of invasiveness of exotic pines outside their natural range. In this paper, we examined genetic variation for constitutive and induced chemical defences (measured as non-volatile resin in the stem and total phenolics in the needles) and resistance to two major native generalist herbivores of pines in cafeteria bioassays (the phloem-feeder Hylobius abietis and the defoliator Thaumetopoea pityocampa) using half-sib families drawn from a sample of the population of Pinus radiata introduced to Spain in the mid-19th century. We found (i) significant genetic variation, with moderate-to-high narrow-sense heritabilities for both the production of constitutive non-volatile resin and induced total phenolics, and for constitutive resistance against T. pityocampa in bioassays, (ii) no evolutionary trade-offs between plant resistance and growth traits or between the production of different quantitative chemical defences and (iii) a positive genetic correlation between constitutive resistance to the two studied herbivores. Overall, results of our study indicate that the exotic pine P. radiata has limited genetic constraints on the evolution of resistance against herbivores in its introduced range, suggesting that, at least in terms of interactions with these enemies, this pine species has potential to become invasive in the future. PMID:23232833

  18. BIG FROG WILDERNESS STUDY AREA AND ADDITIONS, TENNESSEE AND GEORGIA.

    USGS Publications Warehouse

    Slack, John F.; Gazdik, Gertrude C.

    1984-01-01

    A mineral-resource survey was made of the Big Frog Wilderness Study Area and additions, Tennessee-Georgia. Geochemical sampling found traces of gold, zinc, copper, and arsenic in rocks, stream sediments, and panned concentrates, but not in sufficient quantities to indicate the presence of deposits of these metals. The results of the survey indicate that there is little promise for the occurrence of metallic mineral deposits within the study area. The only apparent resources are nonmetallic commodities including rock suitable for construction materials, and small amounts of sand and gravel; however, these commodities are found in abundance outside the study area. A potential may exist for oil and natural gas at great depths, but this cannot be evaluated by the present study.

  19. Recommended Protocol for Round Robin Studies in Additive Manufacturing

    PubMed Central

    Moylan, Shawn; Brown, Christopher U.; Slotwinski, John

    2016-01-01

    One way to improve confidence and encourage proliferation of additive manufacturing (AM) technologies and parts is by generating more high quality data describing the performance of AM processes and parts. Many in the AM community see round robin studies as a way to generate large data sets while distributing the cost among the participants, thereby reducing the cost to individual users. The National Institute of Standards and Technology (NIST) has conducted and participated in several of these AM round robin studies. While the results of these studies are interesting and informative, many of the lessons learned in conducting these studies concern the logistics and methods of the study and unique issues presented by AM. Existing standards for conducting interlaboratory studies of measurement methods, along with NIST’s experience, form the basis for recommended protocols for conducting AM round robin studies. The role of round robin studies in AM qualification, some of the limitations of round robin studies, and the potential benefit of less formal collaborative experiments where multiple factors, AM machine being only one, are varied simultaneously are also discussed. PMID:27274602

  20. Implementation of the Realized Genomic Relationship Matrix to Open-Pollinated White Spruce Family Testing for Disentangling Additive from Nonadditive Genetic Effects

    PubMed Central

    Gamal El-Dien, Omnia; Ratcliffe, Blaise; Klápště, Jaroslav; Porth, Ilga; Chen, Charles; El-Kassaby, Yousry A.

    2016-01-01

    The open-pollinated (OP) family testing combines the simplest known progeny evaluation and quantitative genetics analyses as candidates’ offspring are assumed to represent independent half-sib families. The accuracy of genetic parameter estimates is often questioned as the assumption of “half-sibling” in OP families may often be violated. We compared the pedigree- vs. marker-based genetic models by analysing 22-yr height and 30-yr wood density for 214 white spruce [Picea glauca (Moench) Voss] OP families represented by 1694 individuals growing on one site in Quebec, Canada. Assuming half-sibling, the pedigree-based model was limited to estimating the additive genetic variances which, in turn, were grossly overestimated as they were confounded by very minor dominance and major additive-by-additive epistatic genetic variances. In contrast, the implemented genomic pairwise realized relationship models allowed the disentanglement of additive from all nonadditive factors through genetic variance decomposition. The marker-based models produced more realistic narrow-sense heritability estimates and, for the first time, allowed estimating the dominance and epistatic genetic variances from OP testing. In addition, the genomic models showed better prediction accuracies compared to pedigree models and were able to predict individual breeding values for new individuals from untested families, which was not possible using the pedigree-based model. Clearly, the use of marker-based relationship approach is effective in estimating the quantitative genetic parameters of complex traits even under simple and shallow pedigree structure. PMID:26801647

  1. Addition of molecular methods to mutation studies with Drosophila melanogaster

    SciTech Connect

    Lee, W.R. )

    1989-01-01

    For 80 years, Drosophila melanogaster has been used as a major tool in analyzing Mendelian genetics. By using chromosome inversions that suppress crossing over, geneticists have developed a large number of stocks for mutation analysis. These stocks permit numerous tests for specific locus mutations, lethals at multiple loci on any chromosome, chromosome exchanges, insertions, and deletions. The entire genome can be manipulated for a degree of genetic control not found in other germ-line systems. Recombinant DNA techniques now permit analysis of mutations to the nucleotide level. By combining classical genetic analysis with recombinant DNA techniques, it is possible to analyze mutations that range from chromosome aberrations and multilocus deficiencies to single nucleotide transitions.

  2. Genetics

    MedlinePlus

    Homozygous; Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  3. Genetics

    MedlinePlus

    ... Inheritance; Heterozygous; Inheritance patterns; Heredity and disease; Heritable; Genetic markers ... The chromosomes are made up of strands of genetic information called DNA. Each chromosome contains sections of ...

  4. Genotoxicity studies of the food additive ester gum.

    PubMed

    Mukherjee, A; Agarwal, K; Chakrabarti, J

    1992-07-01

    Ester gum (EG) is used in citrus oil-based beverage flavourings as a weighting or colouring agent. In the present study, concentrations of 50, 100 and 150 mg/kg body weight were administered orally to male Swiss albino mice, and sister chromatid exchange and chromosomal aberration were used as the cytogenetic endpoints to determine the genotoxic and clastogenic potential of the food additive. Although EG was weakly clastogenic and could induce a marginal increase in sister chromatid exchange frequencies, it was not a potential health hazard at the doses tested. PMID:1521837

  5. Statistical Analysis in Genetic Studies of Mental Illnesses

    PubMed Central

    Zhang, Heping

    2011-01-01

    Identifying the risk factors for mental illnesses is of significant public health importance. Diagnosis, stigma associated with mental illnesses, comorbidity, and complex etiologies, among others, make it very challenging to study mental disorders. Genetic studies of mental illnesses date back at least a century ago, beginning with descriptive studies based on Mendelian laws of inheritance. A variety of study designs including twin studies, family studies, linkage analysis, and more recently, genomewide association studies have been employed to study the genetics of mental illnesses, or complex diseases in general. In this paper, I will present the challenges and methods from a statistical perspective and focus on genetic association studies. PMID:21909187

  6. Making intelligent systems team players: Additional case studies

    NASA Technical Reports Server (NTRS)

    Malin, Jane T.; Schreckenghost, Debra L.; Rhoads, Ron W.

    1993-01-01

    Observations from a case study of intelligent systems are reported as part of a multi-year interdisciplinary effort to provide guidance and assistance for designers of intelligent systems and their user interfaces. A series of studies were conducted to investigate issues in designing intelligent fault management systems in aerospace applications for effective human-computer interaction. The results of the initial study are documented in two NASA technical memoranda: TM 104738 Making Intelligent Systems Team Players: Case Studies and Design Issues, Volumes 1 and 2; and TM 104751, Making Intelligent Systems Team Players: Overview for Designers. The objective of this additional study was to broaden the investigation of human-computer interaction design issues beyond the focus on monitoring and fault detection in the initial study. The results of this second study are documented which is intended as a supplement to the original design guidance documents. These results should be of interest to designers of intelligent systems for use in real-time operations, and to researchers in the areas of human-computer interaction and artificial intelligence.

  7. RAMSEYS DRAFT WILDERNESS STUDY AREA AND ADDITION, VIRGINIA.

    USGS Publications Warehouse

    Lesure, Frank G.; Mory, Peter C.

    1984-01-01

    Mineral-resource surveys of the Ramseys Draft Wilderness Study Area and adjoining roadless area addition in George Washington National Forest in the western valley and ridge province, Augusta and Highland Counties, Virginia, were done. The surveys outlined three small areas containing anomalous amounts of copper, lead, and zinc related to stratabound red-bed copper mineralization, but these occurrences are not large and are not considered as having mineral-resource potential. The area contains abundant sandstone suitable for construction materials and shale suitable for making brick, tile, and other low-grade ceramic products, but these commodities occur in abundance outside the wilderness study area. Structural conditions are probably favorable for the accumulation of natural gas, but exploratory drilling has not been done sufficiently near the area to evaluate the gas potential.

  8. Integrating Nonadditive Genomic Relationship Matrices into the Study of Genetic Architecture of Complex Traits.

    PubMed

    Nazarian, Alireza; Gezan, Salvador A

    2016-03-01

    The study of genetic architecture of complex traits has been dramatically influenced by implementing genome-wide analytical approaches during recent years. Of particular interest are genomic prediction strategies which make use of genomic information for predicting phenotypic responses instead of detecting trait-associated loci. In this work, we present the results of a simulation study to improve our understanding of the statistical properties of estimation of genetic variance components of complex traits, and of additive, dominance, and genetic effects through best linear unbiased prediction methodology. Simulated dense marker information was used to construct genomic additive and dominance matrices, and multiple alternative pedigree- and marker-based models were compared to determine if including a dominance term into the analysis may improve the genetic analysis of complex traits. Our results showed that a model containing a pedigree- or marker-based additive relationship matrix along with a pedigree-based dominance matrix provided the best partitioning of genetic variance into its components, especially when some degree of true dominance effects was expected to exist. Also, we noted that the use of a marker-based additive relationship matrix along with a pedigree-based dominance matrix had the best performance in terms of accuracy of correlations between true and estimated additive, dominance, and genetic effects. PMID:26712858

  9. A study of the practice of individual genetic counsellors and genetic nurses in Europe.

    PubMed

    Skirton, Heather; Cordier, Christophe; Lambert, Debby; Hosterey Ugander, Ulrika; Voelckel, Marie-Antoinette; O'Connor, Anita

    2013-01-01

    Advances in genetics have meant that the genetic services are now accessed by increasing numbers of patients. One way of dealing with the pressure on services without jeopardising patient care is the inclusion of nonmedical genetic counsellors and genetic nurses in the genetic services team. However, a cohesive approach to the profession has been lacking in Europe, and an educational programme and registration system for European practitioners is required. The aim of this study was to ascertain the type of work undertaken by genetic nurses and counsellors in Europe and the context in which they practised. We used a cross-sectional survey design to collect data from 213 practitioners, either genetic nurses or genetic counsellors, from 18 European countries. Respondents completed the survey online, and data were analysed using descriptive statistics and cross-tabulations. The majority were involved in undertaking the initial contact with the patient (89.9 %) and explaining the genetic test to the patient (91.5 %), while 74 % ordered tests and 91.4 % obtained informed consent for such tests. Psychological support before and after genetic testing was provided by 80.2 % of respondents, and 82.1 % reported regularly managing cases autonomously. While the genetic counselling profession is barely established in some countries, counsellors are able to contribute substantially to patient care as part of the multi-disciplinary team. Further efforts to establish the profession at the European level through a registration process will enhance the confidence in this new group of allied health professionals. PMID:23055100

  10. Intrauterine diabetic environment confers risks for type 2 diabetes mellitus and obesity in the offspring, in addition to genetic susceptibility.

    PubMed

    Dabelea, D; Pettitt, D J

    2001-01-01

    Numerous studies have reported that offspring whose mothers had type 2 diabetes mellitus (DM) are more likely to develop type 2 DM, impaired glucose tolerance, and obesity at an early age than offspring whose fathers had DM. Exposure to the diabetic intrauterine environment has been shown to be an important risk factor for all these conditions. To what extent transmission of type 2 DM from mother to offspring is the effect of genetic inheritance and to what extent it is the long-term consequence of exposure to maternal hyperglycemia is still uncertain. There are, of course, interactions between the diabetic intrauterine environment and genetics. Several data in experimental animals as well as in humans suggest, however, that exposure of the fetus to the mother's DM confers a risk for type 2 DM and obesity that is above any genetically transmitted susceptibility. In the Pima Indian population much of the increase in childhood type 2 DM can be attributed to the diabetic intrauterine environment. This suggests that intensive glucose control during pregnancy might have extended beneficial effects, contributing to a decrease in the prevalence of childhood type 2 DM. PMID:11592564

  11. Comparative Genetics: Synergizing Human and NOD Mouse Studies for Identifying Genetic Causation of Type 1 Diabetes

    PubMed Central

    Driver, John P.; Chen, Yi-Guang; Mathews, Clayton E.

    2012-01-01

    Although once widely anticipated to unlock how human type 1 diabetes (T1D) develops, extensive study of the nonobese diabetic (NOD) mouse has failed to yield effective treatments for patients with the disease. This has led many to question the usefulness of this animal model. While criticism about the differences between NOD and human T1D is legitimate, in many cases disease in both species results from perturbations modulated by the same genes or different genes that function within the same biological pathways. Like in humans, unusual polymorphisms within an MHC class II molecule contributes the most T1D risk in NOD mice. This insight supports the validity of this model and suggests the NOD has been improperly utilized to study how to cure or prevent disease in patients. Indeed, clinical trials are far from administering T1D therapeutics to humans at the same concentration ranges and pathological states that inhibit disease in NOD mice. Until these obstacles are overcome it is premature to label the NOD mouse a poor surrogate to test agents that cure or prevent T1D. An additional criticism of the NOD mouse is the past difficulty in identifying genes underlying T1D using conventional mapping studies. However, most of the few diabetogenic alleles identified to date appear relevant to the human disorder. This suggests that rather than abandoning genetic studies in NOD mice, future efforts should focus on improving the efficiency with which diabetes susceptibility genes are detected. The current review highlights why the NOD mouse remains a relevant and valuable tool to understand the genes and their interactions that promote autoimmune diabetes and therapeutics that inhibit this disease. It also describes a new range of technologies that will likely transform how the NOD mouse is used to uncover the genetic causes of T1D for years to come. PMID:23804259

  12. Optimal Trend Tests for Genetic Association Studies of Heterogeneous Diseases

    PubMed Central

    Lee, Wen-Chung

    2016-01-01

    The Cochran-Armitage trend test is a standard procedure in genetic association studies. It is a directed test with high power to detect genetic effects that follow the gene-dosage model. In this paper, the author proposes optimal trend tests for genetic association studies of heterogeneous diseases. Monte-Carlo simulations show that the power gain of the optimal trend tests over the conventional Cochran-Armitage trend test is striking when the genetic effects are heterogeneous. The easy-to-use R 3.1.2 software (R Foundation for Statistical Computing, Vienna, Austria) code is provided. The optimal trend tests are recommended for routine use. PMID:27278756

  13. Evolution of the additive genetic variance-covariance matrix under continuous directional selection on a complex behavioural phenotype.

    PubMed

    Careau, Vincent; Wolak, Matthew E; Carter, Patrick A; Garland, Theodore

    2015-11-22

    Given the pace at which human-induced environmental changes occur, a pressing challenge is to determine the speed with which selection can drive evolutionary change. A key determinant of adaptive response to multivariate phenotypic selection is the additive genetic variance-covariance matrix ( G: ). Yet knowledge of G: in a population experiencing new or altered selection is not sufficient to predict selection response because G: itself evolves in ways that are poorly understood. We experimentally evaluated changes in G: when closely related behavioural traits experience continuous directional selection. We applied the genetic covariance tensor approach to a large dataset (n = 17 328 individuals) from a replicated, 31-generation artificial selection experiment that bred mice for voluntary wheel running on days 5 and 6 of a 6-day test. Selection on this subset of G: induced proportional changes across the matrix for all 6 days of running behaviour within the first four generations. The changes in G: induced by selection resulted in a fourfold slower-than-predicted rate of response to selection. Thus, selection exacerbated constraints within G: and limited future adaptive response, a phenomenon that could have profound consequences for populations facing rapid environmental change. PMID:26582016

  14. Expanding the Genetic Code for Biological Studies

    PubMed Central

    Wang, Qian; Parrish, Angela R.; Wang, Lei

    2009-01-01

    Summary Using an orthogonal tRNA-synthetase pair, unnatural amino acids can be genetically encoded with high efficiency and fidelity; and over forty unnatural amino acids have been site-specifically incorporated into proteins in E. coli, yeast, or mammalian cells. Novel chemical or physical properties embodied in these amino acids enable new means for tailored manipulation of proteins. This review summarizes the methodology and recent progress in expanding this technology to eukaryotic cells. Applications of genetically encoded unnatural amino acids are highlighted with reports on labeling and modifying proteins, probing protein structure and function, identifying and regulating protein activity, and generating proteins with new properties. Genetic incorporation of unnatural amino acids provides a powerful method for investigating a wide variety of biological processes both in vitro and in vivo. PMID:19318213

  15. A new dawn for genetic association studies in multiple sclerosis.

    PubMed

    Kantarci, Orhun H

    2016-08-01

    Before the genomics technology revolution allowed us to do genome-wide science, genetics research relied on our limited knowledge about a subject to generate hypothesis and candidate genes to study. Despite the level of naiveté, several associations with susceptibility to a complex disease such as multiple sclerosis (MS) were discovered. Of these, HLA-DRB1 and IL7R (1) stand out as being confirmed and refined early by the genome-wide association studies (GWAS) that followed.(2) Despite the expense and gargantuan efforts, these GWAS have successfully led to the discovery of more than 100 additional genes, albeit with smaller effect sizes, that contribute to MS susceptibility.(3) This list keeps growing, but it comes with no surprise that most of these genes identified the immune system as one large candidate for MS susceptibility. PMID:27540593

  16. A "Genetic Study" of the Galaxy

    NASA Astrophysics Data System (ADS)

    2006-09-01

    Looking in detail at the composition of stars with ESO's VLT, astronomers are providing a fresh look at the history of our home galaxy, the Milky Way. They reveal that the central part of our Galaxy formed not only very quickly but also independently of the rest. "For the first time, we have clearly established a 'genetic difference' between stars in the disc and the bulge of our Galaxy," said Manuela Zoccali, lead author of the paper presenting the results in the journal Astronomy and Astrophysics [1]. "We infer from this that the bulge must have formed more rapidly than the disc, probably in less than a billion years and when the Universe was still very young." ESO PR Photo 34a/06 ESO PR Photo 34a/06 The Field around Baade's Window The Milky Way is a spiral galaxy, having pinwheel-shaped arms of gas, dust, and stars lying in a flattened disc, and extending directly out from a spherical nucleus of stars in the central region. The spherical nucleus is called a bulge, because it bulges out from the disc. While the disc of our Galaxy is made up of stars of all ages, the bulge contains old stars dating from the time the galaxy formed, more than 10 billion years ago. Thus, studying the bulge allows astronomers to know more about how our Galaxy formed. To do this, an international team of astronomers [2] analysed in detail the chemical composition of 50 giant stars in four different areas of the sky towards the Galactic bulge. They made use of the FLAMES/UVES spectrograph on ESO's Very Large Telescope to obtain high-resolution spectra. The chemical composition of stars carries the signature of the enrichment processes undergone by the interstellar matter up to the moment of their formation. It depends on the previous history of star formation and can thus be used to infer whether there is a 'genetic link' between different stellar groups. In particular, comparison between the abundance of oxygen and iron in stars is very illustrative. Oxygen is predominantly produced in

  17. Strategies for enrollment of African Americans into cancer genetic studies.

    PubMed

    Ewing, Altovise; Thompson, Nicole; Ricks-Santi, Luisel

    2015-03-01

    The enrollment of ethnically diverse populations in genetic and genomic research is vital to the parity of benefits resulting from research with biological specimens. Herein, we discuss strategies that may effectively improve the recruitment of African Americans into genetics studies. Specifically, we show that engaging physicians, genetic counselors, and community members is essential to enrolling participants into genetic studies. We demonstrate the impact of utilizing African American genetic counselors on study enrollment rates and implementing a two-page consent form that improved on a lengthy and inefficient consenting process. Lastly, we provided participants with the option of donating saliva instead of blood for study purposes. Descriptive statistics were used. Using the aforementioned strategies, recruitment goals for the Genetic Basis of Breast Cancer Subtype Study at Howard University (HU) were met. Our overall results yielded 182 participants in 18 months. Recruitment strategies that involve the engagement of physicians, genetic counselors, and community members may help researchers increase the enrollment of ethnically diverse and hard-to-reach participants into genetic studies. PMID:24882437

  18. Strategies for Enrollment of African Americans into Cancer Genetic Studies

    PubMed Central

    Thompson, Nicole; Ricks-Santi, Luisel

    2014-01-01

    The enrollment of ethnically diverse populations in genetic and genomic research is vital to the parity of benefits resulting from research with biological specimens. Herein, we discuss strategies that may effectively improve the recruitment of African Americans into genetics studies. Specifically, we show that engaging physicians, genetic counselors, and community members is essential to enrolling participants into genetic studies. We demonstrate the impact of utilizing African American genetic counselors on study enrollment rates and implementing a two-page consent form that improved on a lengthy and inefficient consenting process. Lastly, we provided participants with the option of donating saliva instead of blood for study purposes. Descriptive statistics were used. Using the aforementioned strategies, recruitment goals for the Genetic Basis of Breast Cancer Subtype Study at Howard University (HU) were met. Our overall results yielded 182 participants in 18 months. Recruitment strategies that involve the engagement of physicians, genetic counselors, and community members may help researchers increase the enrollment of ethnically diverse and hard-to-reach participants into genetic studies. PMID:24882437

  19. Medical Genetics and the First Studies of the Genetics of Populations in Mexico.

    PubMed

    Barahona, Ana

    2016-09-01

    Following World War II (WWII), there was a new emphasis within genetics on studying the genetic composition of populations. This probably had a dual source in the growing strength of evolutionary biology and the new international interest in understanding the effects of radiation on human populations, following the atomic bombings in Japan. These global concerns were shared by Mexican physicians. Indeed, Mexico was one of the leading centers of this trend in human genetics. Three leading players in this story were Mario Salazar Mallén, Adolfo Karl, and Rubén Lisker. Their trajectories and the international networks in human genetics that were established after WWII, paved the way for the establishment of medical and population genetics in Mexico. Salazar Mallén's studies on the distribution and characterization of ABO blood groups in indigenous populations were the starting point while Karl's studies on the distribution of abnormal hemoglobin in Mexican indigenous populations showed the relationships observed in other laboratories at the time. It was Lisker's studies, however, that were instrumental in the development of population genetics in the context of national public policies for extending health care services to the Mexican population. In particular, he conducted studies on Mexican indigenous groups contributing to the knowledge of the biological diversity of human populations according to international trends that focused on the variability of human populations in terms of genetic frequencies. From the start, however, Lisker was as committed to the reconstruction of shared languages and practices as he was to building networks of collaboration in order to guarantee the necessary groundwork for establishing the study of the genetics of human populations in Mexico. This study also allows us to place Mexican science within a global context in which connected narratives describe the interplay between global trends and national contexts. PMID:27601615

  20. Imaging genetics studies on monoaminergic genes in major depressive disorder.

    PubMed

    Won, Eunsoo; Ham, Byung-Joo

    2016-01-01

    Although depression is the leading cause of disability worldwide, current understanding of the neurobiology of depression has failed to be translated into clinical practice. Major depressive disorder (MDD) pathogenesis is considered to be significantly influenced by multiple risk genes, however genetic effects are not simply expressed at a behavioral level. Therefore the concept of endophenotype has been applied in psychiatric genetics. Imaging genetics applies anatomical or functional imaging technologies as phenotypic assays to evaluate genetic variation and their impact on behavior. This paper attempts to provide a comprehensive review of available imaging genetics studies, including reports on genetic variants that have most frequently been linked to MDD, such as the monoaminergic genes (serotonin transporter gene, monoamine oxidase A gene, tryptophan hydroxylase-2 gene, serotonin receptor 1A gene and catechol-O-methyl transferase gene), with regard to key structures involved in emotion processing, such as the hippocampus, amygdala, anterior cingulate cortex and orbitofrontal cortex. PMID:25828849

  1. Genetic Counseling of Adults with Williams Syndrome: A First Study

    PubMed Central

    Farwig, Katrina; Harmon, Amanda G.; Fontana, Kristina M.; Mervis, Carolyn B.; Morris, Colleen A.

    2010-01-01

    We report on a study of genetic counseling to 43 adults with Williams syndrome (WS). Participants were initially asked what they knew about how WS occurs. Genetic counseling was provided with a focus on the basic genetics of WS, recurrence risk, and on participants’ attitudes toward socio-cultural topics. Forty nine % indicated they would be okay or happy if their baby had WS, 44% said they would be sad or upset, and 5% were unsure. The sad/upset group was significantly older than the okay/happy group and a significantly higher proportion of the former group indicated they did not plan to have children. During the post counseling session participants were questioned to determine if they recalled the facts previously presented. Eighy one % correctly gave the odds that their child would have WS. Fifty three % considered the 50-50 odds to be a high chance. After genetic counseling, 61% were able to state something that had been taught, and 88% indicated they would want to test their baby for WS before birth. Ninety eight% would recommend genetic counseling to others. Findings indicate that based on the type of genetic counseling provided in this study, the majority of individuals with WS—a genetic disorder associated with intellectual disability but with relative strengths in (concrete) language and in verbal rote memory—are able to learn simple facts about the genetics of WS and are eager to respond to socio-cultural questions regarding topics typically included in genetic counseling sessions. PMID:20425790

  2. Genetic study of skin thickness and its association with postweaning growth in Nellore cattle: estimation of the genetic parameters.

    PubMed

    Maiorano, A M; Oliveira, M C S; Cyrillo, J N S G; Albuquerque, L G; Curi, R A; Silva, J A Iiv

    2016-01-01

    The objective of the present study was to estimate genetic parameters for skin thickness (ST) and postweaning weight gain (PWG550) in Nellore cattle. Records were obtained from 152,392 Nellore animals born between 2001 and 2011. ST was measured in the posterior region of the animal's scapula with a millimeter caliper. The animals were assigned to different contemporary groups, formed on the basis of farm, year, sex, feeding regimen at weaning, date of weaning, feeding regimen at 450 days of age, and date of weighing at 450 days of age. The genetic parameters were estimated by Bayesian analysis using the GIBBS1F90 program. The mean ST and PWG550 observed were 7.71 ± 2.04 mm and 115.95 ± 36.17 kg, respectively. The posterior mean estimates of heritability (h2) were 0.12 ± 0.02 and 0.29 ± 0.02 for ST and PWG550, respectively. The posterior mean estimates of the phenotypic, genetic, and environmental correlations between the traits were 0.16 ± 0.0, 0.17 ± 0.02, and 0.17 ± 0.09, respectively. The traits ST and PWG550 showed sufficient additive genetic variance to be used as selection criteria in breeding programs. The low genetic correlation obtained indicates that genes favoring the expression of one trait may not influence the other. Consequently, a selection favoring ST would be less efficient in increasing PWG550. PMID:26909980

  3. Replication of a Gene-Environment Interaction via Multimodel Inference: Additive-Genetic Variance in Adolescents’ General Cognitive Ability Increases with Family-of-Origin Socioeconomic Status

    PubMed Central

    Kirkpatrick, Robert M.; McGue, Matt; Iacono, William G.

    2015-01-01

    The present study of general cognitive ability attempts to replicate and extend previous investigations of a biometric moderator, family-of-origin socioeconomic status (SES), in a sample of 2,494 pairs of adolescent twins, non-twin biological siblings, and adoptive siblings assessed with individually administered IQ tests. We hypothesized that SES would covary positively with additive-genetic variance and negatively with shared-environmental variance. Important potential confounds unaddressed in some past studies, such as twin-specific effects, assortative mating, and differential heritability by trait level, were found to be negligible. In our main analysis, we compared models by their sample-size corrected AIC, and base our statistical inference on model-averaged point estimates and standard errors. Additive-genetic variance increased with SES—an effect that was statistically significant and robust to model specification. We found no evidence that SES moderated shared-environmental influence. We attempt to explain the inconsistent replication record of these effects, and provide suggestions for future research. PMID:25539975

  4. Replication of a gene-environment interaction Via Multimodel inference: additive-genetic variance in adolescents' general cognitive ability increases with family-of-origin socioeconomic status.

    PubMed

    Kirkpatrick, Robert M; McGue, Matt; Iacono, William G

    2015-03-01

    The present study of general cognitive ability attempts to replicate and extend previous investigations of a biometric moderator, family-of-origin socioeconomic status (SES), in a sample of 2,494 pairs of adolescent twins, non-twin biological siblings, and adoptive siblings assessed with individually administered IQ tests. We hypothesized that SES would covary positively with additive-genetic variance and negatively with shared-environmental variance. Important potential confounds unaddressed in some past studies, such as twin-specific effects, assortative mating, and differential heritability by trait level, were found to be negligible. In our main analysis, we compared models by their sample-size corrected AIC, and base our statistical inference on model-averaged point estimates and standard errors. Additive-genetic variance increased with SES-an effect that was statistically significant and robust to model specification. We found no evidence that SES moderated shared-environmental influence. We attempt to explain the inconsistent replication record of these effects, and provide suggestions for future research. PMID:25539975

  5. Experimental Study of Additives on Viscosity biodiesel at Low Temperature

    NASA Astrophysics Data System (ADS)

    Fajar, Berkah; Sukarno

    2015-09-01

    An experimental investigation was performed to find out the viscosity of additive and biodiesel fuel mixture in the temperature range from 283 K to 318 K. Solutions to reduce the viscosity of biodiesel is to add the biodiesel with some additive. The viscosity was measured using a Brookfield Rheometer DV-II. The additives were the generic additive (Diethyl Ether/DDE) and the commercial additive Viscoplex 10-330 CFI. Each biodiesel blends had a concentration of the mixture: 0.0; 0.25; 0.5; 0.75; 1.0; and 1.25% vol. Temperature of biodiesel was controlled from 40°C to 0°C. The viscosity of biodiesel and additive mixture at a constant temperature can be approximated by a polynomial equation and at a constant concentration by exponential equation. The optimum mixture is at 0.75% for diethyl ether and 0.5% for viscoplex.

  6. The severity of retinal pathology in homozygous Crb1rd8/rd8 mice is dependent on additional genetic factors

    PubMed Central

    Luhmann, Ulrich F.O.; Carvalho, Livia S.; Holthaus, Sophia-Martha kleine; Cowing, Jill A.; Greenaway, Simon; Chu, Colin J.; Herrmann, Philipp; Smith, Alexander J.; Munro, Peter M.G.; Potter, Paul; Bainbridge, James W.B.; Ali, Robin R.

    2015-01-01

    Understanding phenotype–genotype correlations in retinal degeneration is a major challenge. Mutations in CRB1 lead to a spectrum of autosomal recessive retinal dystrophies with variable phenotypes suggesting the influence of modifying factors. To establish the contribution of the genetic background to phenotypic variability associated with the Crb1rd8/rd8 mutation, we compared the retinal pathology of Crb1rd8/rd8/J inbred mice with that of two Crb1rd8/rd8 lines backcrossed with C57BL/6JOlaHsd mice. Topical endoscopic fundal imaging and scanning laser ophthalmoscopy fundus images of all three Crb1rd8/rd8 lines showed a significant increase in the number of inferior retinal lesions that was strikingly variable between the lines. Optical coherence tomography, semithin, ultrastructural morphology and assessment of inflammatory and vascular marker by immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction revealed that the lesions were associated with photoreceptor death, Müller and microglia activation and telangiectasia-like vascular remodelling—features that were stable in the inbred, variable in the second, but virtually absent in the third Crb1rd8/rd8 line, even at 12 months of age. This suggests that the Crb1rd8/rd8 mutation is necessary, but not sufficient for the development of these degenerative features. By whole-genome SNP analysis of the genotype–phenotype correlation, a candidate region on chromosome 15 was identified. This may carry one or more genetic modifiers for the manifestation of the retinal pathology associated with mutations in Crb1. This study also provides insight into the nature of the retinal vascular lesions that likely represent a clinical correlate for the formation of retinal telangiectasia or Coats-like vasculopathy in patients with CRB1 mutations that are thought to depend on such genetic modifiers. PMID:25147295

  7. The severity of retinal pathology in homozygous Crb1rd8/rd8 mice is dependent on additional genetic factors.

    PubMed

    Luhmann, Ulrich F O; Carvalho, Livia S; Holthaus, Sophia-Martha Kleine; Cowing, Jill A; Greenaway, Simon; Chu, Colin J; Herrmann, Philipp; Smith, Alexander J; Munro, Peter M G; Potter, Paul; Bainbridge, James W B; Ali, Robin R

    2015-01-01

    Understanding phenotype-genotype correlations in retinal degeneration is a major challenge. Mutations in CRB1 lead to a spectrum of autosomal recessive retinal dystrophies with variable phenotypes suggesting the influence of modifying factors. To establish the contribution of the genetic background to phenotypic variability associated with the Crb1(rd8/rd8) mutation, we compared the retinal pathology of Crb1(rd8/rd8)/J inbred mice with that of two Crb1(rd8/rd8) lines backcrossed with C57BL/6JOlaHsd mice. Topical endoscopic fundal imaging and scanning laser ophthalmoscopy fundus images of all three Crb1(rd8/rd8) lines showed a significant increase in the number of inferior retinal lesions that was strikingly variable between the lines. Optical coherence tomography, semithin, ultrastructural morphology and assessment of inflammatory and vascular marker by immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction revealed that the lesions were associated with photoreceptor death, Müller and microglia activation and telangiectasia-like vascular remodelling-features that were stable in the inbred, variable in the second, but virtually absent in the third Crb1(rd8/rd8) line, even at 12 months of age. This suggests that the Crb1(rd8/rd8) mutation is necessary, but not sufficient for the development of these degenerative features. By whole-genome SNP analysis of the genotype-phenotype correlation, a candidate region on chromosome 15 was identified. This may carry one or more genetic modifiers for the manifestation of the retinal pathology associated with mutations in Crb1. This study also provides insight into the nature of the retinal vascular lesions that likely represent a clinical correlate for the formation of retinal telangiectasia or Coats-like vasculopathy in patients with CRB1 mutations that are thought to depend on such genetic modifiers. PMID:25147295

  8. Genetic studies of freshwater turtle and tortoises: a review of the past 70 years

    USGS Publications Warehouse

    FitzSimmons, Nancy N.; Hart, Kristen M.

    2007-01-01

    Powerful molecular techniques have been developed over many decades for resolving genetic relationships, population genetic structure, patterns of gene flow, mating systems, and the amount of genetic diversity in animals. Genetic studies of turtles were among the earliest and the rapid application of new genetic tools and analytical techniques is still apparent in the literature on turtles. At present, of the 198 freshwater turtles and tortoises that are listed as not extinct by the IUCN Red List, 69 species worldwide are listed as endangered or critically endangered, and an additional 56 species are listed as vulnerable. Of the ca. 300 species of the freshwater turtles and tortoises in the world, ca. 42% are considered to be facing a high risk extinction, and there is a need to focus intense conservation attention on these species. This includes a need to (i) assess our current state of knowledge regarding the application of genetics to studies of freshwater turtles and tortoises and (ii) determine future research directions. Here, we review all available published studies for the past 70 years that were written in English and used genetic markers (e.g. karyotypes, allozymes, DNA loci) to better understand the biology of freshwater turtles and tortoises. We review the types of studies conducted in relation to the species studied and quantify the countries where the studies were performed. We rack the changing use of different genetic markers through time and report on studies focused on aspects of molecular evolution within turtle genomes. We address the usefulness of particular genetic markers to answer phylogenetic questions and present data comparing population genetic structure and mating systems across species. We draw specific attention to whether authors have considered issues to turtle conservation in their research or provided new insights that have been translated into recommendations for conservation management.

  9. Additive Manufacturing in Production: A Study Case Applying Technical Requirements

    NASA Astrophysics Data System (ADS)

    Ituarte, Iñigo Flores; Coatanea, Eric; Salmi, Mika; Tuomi, Jukka; Partanen, Jouni

    Additive manufacturing (AM) is expanding the manufacturing capabilities. However, quality of AM produced parts is dependent on a number of machine, geometry and process parameters. The variability of these parameters affects the manufacturing drastically and therefore standardized processes and harmonized methodologies need to be developed to characterize the technology for end use applications and enable the technology for manufacturing. This research proposes a composite methodology integrating Taguchi Design of Experiments, multi-objective optimization and statistical process control, to optimize the manufacturing process and fulfil multiple requirements imposed to an arbitrary geometry. The proposed methodology aims to characterize AM technology depending upon manufacturing process variables as well as to perform a comparative assessment of three AM technologies (Selective Laser Sintering, Laser Stereolithography and Polyjet). Results indicate that only one machine, laser-based Stereolithography, was feasible to fulfil simultaneously macro and micro level geometrical requirements but mechanical properties were not at required level. Future research will study a single AM system at the time to characterize AM machine technical capabilities and stimulate pre-normative initiatives of the technology for end use applications.

  10. From genetic studies to precision medicine in alcohol dependence.

    PubMed

    Sun, Yan; Zhang, Yan; Wang, Fan; Sun, Yankun; Shi, Jie; Lu, Lin

    2016-04-01

    Genetic factors contribute to more than 50% of the variation in the vulnerability to alcohol dependence (AD). Although significant advances have been made in medications for AD, these medications do not work for all people. Precise tailoring of medicinal strategies for individual alcoholic patients is needed to achieve optimal outcomes. This review updates the most promising information on genetic variants in AD, which may be useful for improving diagnostic, therapeutic, and monitoring strategies. We describe genetic candidates of various neurotransmitter and enzyme systems. In addition to biological and allelic associations with AD, genetic effects on AD-related phenotypes and treatment responses have also been described. Gene-gene and gene-environment interactions have been considered. Potential applications of genomewide and epigenetic approaches for identifying genetic biomarkers of AD have been discussed. Overall, the application of genetic findings in precision medicine for AD will likely involve an integrated approach that distinguishes effect sizes of specific genetic predictors with regard to sex, pharmacotherapy, ethnicity, and AD-related aspects and considers gene-gene and gene-environment interactions. Our work may pave the way toward more precise treatment for AD that could ultimately improve clinical management and interventions. PMID:26580132

  11. Genetic Epidemiology of Tuberculosis Susceptibility: Impact of Study Design

    PubMed Central

    Stein, Catherine M.

    2011-01-01

    Several candidate gene studies have provided evidence for a role of host genetics in susceptibility to tuberculosis (TB). However, the results of these studies have been very inconsistent, even within a study population. Here, we review the design of these studies from a genetic epidemiological perspective, illustrating important differences in phenotype definition in both cases and controls, consideration of latent M. tuberculosis infection versus active TB disease, population genetic factors such as population substructure and linkage disequilibrium, polymorphism selection, and potential global differences in M. tuberculosis strain. These considerable differences between studies should be accounted for when examining the current literature. Recommendations are made for future studies to further clarify the host genetics of TB. PMID:21283783

  12. Genetic architecture for human aggression: A study of gene-phenotype relationship in OMIM.

    PubMed

    Zhang-James, Yanli; Faraone, Stephen V

    2016-07-01

    Genetic studies of human aggression have mainly focused on known candidate genes and pathways regulating serotonin and dopamine signaling and hormonal functions. These studies have taught us much about the genetics of human aggression, but no genetic locus has yet achieved genome-significance. We here present a review based on a paradoxical hypothesis that studies of rare, functional genetic variations can lead to a better understanding of the molecular mechanisms underlying complex multifactorial disorders such as aggression. We examined all aggression phenotypes catalogued in Online Mendelian Inheritance in Man (OMIM), an Online Catalog of Human Genes and Genetic Disorders. We identified 95 human disorders that have documented aggressive symptoms in at least one individual with a well-defined genetic variant. Altogether, we retrieved 86 causal genes. Although most of these genes had not been implicated in human aggression by previous studies, the most significantly enriched canonical pathways had been previously implicated in aggression (e.g., serotonin and dopamine signaling). Our findings provide strong evidence to support the causal role of these pathways in the pathogenesis of aggression. In addition, the novel genes and pathways we identified suggest additional mechanisms underlying the origins of human aggression. Genome-wide association studies with very large samples will be needed to determine if common variants in these genes are risk factors for aggression. © 2015 Wiley Periodicals, Inc. PMID:26288127

  13. Autism and genetics: Clinical approach and association study with two markers of HRAS gene

    SciTech Connect

    Herault, J.; Petit, E.; Cherpi, C.

    1995-08-14

    Twin studies and familial aggregation studies indicate that genetic factors could play a role in infantile autism. In an earlier study, we identified a possible positive association between autism and a c-Harvey-ras (HRAS) oncogene marker at the 3{prime} end of the coding region. In an attempt to confirm this finding, we studied a larger population, well-characterized clinically and genetically. We report a positive association between autism and two HRAS markers, the 3{prime} marker used in the initial study and an additional marker in exon 1. 46 refs., 1 fig., 2 tabs.

  14. Metabolic Profiles and Genetic Diversity of Denitrifying Communities in Activated Sludge after Addition of Methanol or Ethanol†

    PubMed Central

    Hallin, Sara; Throbäck, Ingela Noredal; Dicksved, Johan; Pell, Mikael

    2006-01-01

    External carbon sources can enhance denitrification rates and thus improve nitrogen removal in wastewater treatment plants. The effects of adding methanol and ethanol on the genetic and metabolic diversity of denitrifying communities in activated sludge were compared using a pilot-scale plant with two parallel lines. A full-scale plant receiving the same municipal wastewater, but without external carbon source addition, was the reference. Metabolic profiles obtained from potential denitrification rates with 10 electron donors showed that the denitrifying communities altered their preferences for certain compounds after supplementation with methanol or ethanol and that methanol had the greater impact. Clone libraries of nirK and nirS genes, encoding the two different nitrite reductases in denitrifiers, revealed that methanol also increased the diversity of denitrifiers of the nirS type, which indicates that denitrifiers favored by methanol were on the rise in the community. This suggests that there might be a niche differentiation between nirS and nirK genotypes during activated sludge processes. The composition of nirS genotypes also varied greatly among all samples, whereas the nirK communities were more stable. The latter was confirmed by denaturing gradient gel electrophoresis of nirK communities on all sampling occasions. Our results support earlier hypotheses that the compositions of denitrifier communities change during predenitrification processes when external carbon sources are added, although no severe effect could be observed from an operational point of view. PMID:16885297

  15. Health studies indicate MTBE is safe gasoline additive

    SciTech Connect

    Anderson, E.V.

    1993-09-01

    Implementation of the oxygenated fuels program by EPA in 39 metropolitan areas, including Fairbanks and Anchorage, Alaska, in the winter of 1992, encountered some unexpected difficulties. Complaints of headaches, dizziness, nausea, and irritated eyes started in Fairbanks, jumped to Anchorage, and popped up in various locations in the lower 48 states. The suspected culprit behind these complaints was the main additive for oxygenation of gasoline is methyl tert-butyl ether (MTBE). A test program, hastily organized in response to these complaints, has indicated that MTBE is a safe gasoline additive. However, official certification of the safety of MTBE is still awaited.

  16. Genetic studies of Unverricht-Luendborg disease

    SciTech Connect

    Lafreniere, R.G.; Dube, M.P.; Rouleau, G.A.

    1994-09-01

    Unverricht-Luendborg disease (ULD) is a progressive myoclonus epilepsy with an age of onset between 6 and 13 years, myoclonic jerks that progressively worsen, and mental deterioration. ULD shows an autosomal recessive mode of inheritance. The ULD gene has been genetically linked to 21q22.3, and more recently estimated to lie within 0.3 cM of the markers PFKL, D21S25, and D21S154, based on linkage disequilibrium. We have previously identified eight families affected with ULD and shown linkage to 21q22.3. In our efforts to identify the metabolic basis of the disease, we have identified several other families with ULD and are testing them for linkage to 21q22.3 We are also constructing a cosmid and YAC contig of the candidate EPM1 region in 21q22.3 and are in the process of identifying candidate genes therefrom.

  17. ALS: Recent Developments from Genetics Studies.

    PubMed

    Therrien, Martine; Dion, Patrick A; Rouleau, Guy A

    2016-06-01

    Amyotrophic lateral sclerosis (ALS) is a fatal disorder that is characterized by a progressive degeneration of the upper and lower motor neurons. Most cases appear to be sporadic, but 5-10 % of cases have a family history of the disease. High-throughput DNA sequencing and related genomic capture tools are methodological advances which have rapidly contributed to an acceleration in the discovery of genetic risk factors for both familial and sporadic ALS. It is interesting to note that as the number of ALS genes grows, many of the proteins they encode are in shared intracellular processes. This review will summarize some of the recent advances and gene discovery made in ALS. PMID:27113253

  18. Additive transgene expression and genetic introgression in multiple green-fluorescent protein transgenic crop x weed hybrid generations.

    PubMed

    Halfhill, M D; Millwood, R J; Weissinger, A K; Warwick, S I; Stewart, C N

    2003-11-01

    The level of transgene expression in crop x weed hybrids and the degree to which crop-specific genes are integrated into hybrid populations are important factors in assessing the potential ecological and agricultural risks of gene flow associated with genetic engineering. The average transgene zygosity and genetic structure of transgenic hybrid populations change with the progression of generations, and the green fluorescent protein (GFP) transgene is an ideal marker to quantify transgene expression in advancing populations. The homozygous T(1) single-locus insert GFP/ Bacillus thuringiensis (Bt) transgenic canola ( Brassica napus, cv Westar) with two copies of the transgene fluoresced twice as much as hemizygous individuals with only one copy of the transgene. These data indicate that the expression of the GFP gene was additive, and fluorescence could be used to determine zygosity status. Several hybrid generations (BC(1)F(1), BC(2)F(1)) were produced by backcrossing various GFP/Bt transgenic canola ( B. napus, cv Westar) and birdseed rape ( Brassica rapa) hybrid generations onto B. rapa. Intercrossed generations (BC(2)F(2) Bulk) were generated by crossing BC(2)F(1) individuals in the presence of a pollinating insect ( Musca domestica L.). The ploidy of plants in the BC(2)F(2) Bulk hybrid generation was identical to the weedy parental species, B. rapa. AFLP analysis was used to quantify the degree of B. napus introgression into multiple backcross hybrid generations with B. rapa. The F(1) hybrid generations contained 95-97% of the B. napus-specific AFLP markers, and each successive backcross generation demonstrated a reduction of markers resulting in the 15-29% presence in the BC(2)F(2) Bulk population. Average fluorescence of each successive hybrid generation was analyzed, and homozygous canola lines and hybrid populations that contained individuals homozygous for GFP (BC(2)F(2) Bulk) demonstrated significantly higher fluorescence than hemizygous hybrid

  19. Multiple Comparisons in Genetic Association Studies: A Hierarchical Modeling Approach

    PubMed Central

    Yi, Nengjun; Xu, Shizhong; Lou, Xiang-Yang; Mallick, Himel

    2016-01-01

    Multiple comparisons or multiple testing has been viewed as a thorny issue in genetic association studies aiming to detect disease-associated genetic variants from a large number of genotyped variants. We alleviate the problem of multiple comparisons by proposing a hierarchical modeling approach that is fundamentally different from the existing methods. The proposed hierarchical models simultaneously fit as many variables as possible and shrink unimportant effects towards zero. Thus, the hierarchical models yield more efficient estimates of parameters than the traditional methods that analyze genetic variants separately, and also coherently address the multiple comparisons problem due to largely reducing the effective number of genetic effects and the number of statistically ‘significant’ effects. We develop a method for computing the effective number of genetic effects in hierarchical generalized linear models, and propose a new adjustment for multiple comparisons, the hierarchical Bonferroni correction, based on the effective number of genetic effects. Our approach not only increases the power to detect disease-associated variants but also controls the Type I error. We illustrate and evaluate our method with real and simulated data sets from genetic association studies. The method has been implemented in our freely available R package BhGLM (http://www.ssg.uab.edu/bhglm/). PMID:24259248

  20. A drosophila genetic resource of mutants to study mechanisms underlying human genetic diseases.

    PubMed

    Yamamoto, Shinya; Jaiswal, Manish; Charng, Wu-Lin; Gambin, Tomasz; Karaca, Ender; Mirzaa, Ghayda; Wiszniewski, Wojciech; Sandoval, Hector; Haelterman, Nele A; Xiong, Bo; Zhang, Ke; Bayat, Vafa; David, Gabriela; Li, Tongchao; Chen, Kuchuan; Gala, Upasana; Harel, Tamar; Pehlivan, Davut; Penney, Samantha; Vissers, Lisenka E L M; de Ligt, Joep; Jhangiani, Shalini N; Xie, Yajing; Tsang, Stephen H; Parman, Yesim; Sivaci, Merve; Battaloglu, Esra; Muzny, Donna; Wan, Ying-Wooi; Liu, Zhandong; Lin-Moore, Alexander T; Clark, Robin D; Curry, Cynthia J; Link, Nichole; Schulze, Karen L; Boerwinkle, Eric; Dobyns, William B; Allikmets, Rando; Gibbs, Richard A; Chen, Rui; Lupski, James R; Wangler, Michael F; Bellen, Hugo J

    2014-09-25

    Invertebrate model systems are powerful tools for studying human disease owing to their genetic tractability and ease of screening. We conducted a mosaic genetic screen of lethal mutations on the Drosophila X chromosome to identify genes required for the development, function, and maintenance of the nervous system. We identified 165 genes, most of whose function has not been studied in vivo. In parallel, we investigated rare variant alleles in 1,929 human exomes from families with unsolved Mendelian disease. Genes that are essential in flies and have multiple human homologs were found to be likely to be associated with human diseases. Merging the human data sets with the fly genes allowed us to identify disease-associated mutations in six families and to provide insights into microcephaly associated with brain dysgenesis. This bidirectional synergism between fly genetics and human genomics facilitates the functional annotation of evolutionarily conserved genes involved in human health. PMID:25259927

  1. A Drosophila genetic resource of mutants to study mechanisms underlying human genetic diseases

    PubMed Central

    Yamamoto, Shinya; Jaiswal, Manish; Charng, Wu-Lin; Gambin, Tomasz; Karaca, Ender; Mirzaa, Ghayda; Wiszniewski, Wojciech; Sandoval, Hector; Haelterman, Nele A.; Xiong, Bo; Zhang, Ke; Bayat, Vafa; David, Gabriela; Li, Tongchao; Chen, Kuchuan; Gala, Upasana; Harel, Tamar; Pehlivan, Davut; Penney, Samantha; Vissers, Lisenka E. L. M.; de Ligt, Joep; Jhangiani, Shalini; Xie, Yajing; Tsang, Stephen H.; Parman, Yesim; Sivaci, Merve; Battaloglu, Esra; Muzny, Donna; Wan, Ying-Wooi; Liu, Zhandong; Lin-Moore, Alexander T.; Clark, Robin D.; Curry, Cynthia J.; Link, Nichole; Schulze, Karen L.; Boerwinkle, Eric; Dobyns, William B.; Allikmets, Rando; Gibbs, Richard A.; Chen, Rui; Lupski, James R.; Wangler, Michael F.; Bellen, Hugo J.

    2014-01-01

    Summary Invertebrate model systems are powerful tools for studying human disease owing to their genetic tractability and ease of screening. We conducted a mosaic genetic screen of lethal mutations on the Drosophila X-chromosome to identify genes required for the development, function, and maintenance of the nervous system. We identified 165 genes, most of whose function has not been studied in vivo. In parallel, we investigated rare variant alleles in 1,929 human exomes from families with unsolved Mendelian disease. Genes that are essential in flies and have multiple human homologs were found to be likely to be associated with human diseases. Merging the human datasets with the fly genes allowed us to identify disease-associated mutations in six families and to provide insights into microcephaly associated with brain dysgenesis. This bidirectional synergism between fly genetics and human genomics facilitates the functional annotation of evolutionarily conserved genes involved in human health. PMID:25259927

  2. A systematic study of genetic algorithms with genotype editing

    SciTech Connect

    Huang, C. F.; Rocha, L. M.

    2004-01-01

    This paper presents our systematic study on an RNA-editing computational model of Genetic Algorithms (GA). This model is constructed based on several genetic editing characteristics that are gleaned from the RNA editing system as observed in several organisms. We have expanded the traditional Genetic Algorithm with artificial editing mechanisms as proposed by [15]. The incorporation of editing mechanisms provides a means for artificial agents with genetic descriptions to gain greater phenotypic plasticity, which may be environmentally regulated. The systematic study of this RNA-editing model has shed some light into the evolutionary implications of RNA editing and how to select proper RNA editors for design of more robust GAS. The results will also show promising applications to complex real-world problems. We expect that the framework proposed will both facilitate determining the evolutionary role of RNA editing in biology, and advance the current state of research in Evolutionary Computation.

  3. SNPTrack™ : an integrated bioinformatics system for genetic association studies.

    PubMed

    Xu, Joshua; Kelly, Reagan; Zhou, Guangxu; Turner, Steven A; Ding, Don; Harris, Stephen C; Hong, Huixiao; Fang, Hong; Tong, Weida

    2012-01-01

    A genetic association study is a complicated process that involves collecting phenotypic data, generating genotypic data, analyzing associations between genotypic and phenotypic data, and interpreting genetic biomarkers identified. SNPTrack is an integrated bioinformatics system developed by the US Food and Drug Administration (FDA) to support the review and analysis of pharmacogenetics data resulting from FDA research or submitted by sponsors. The system integrates data management, analysis, and interpretation in a single platform for genetic association studies. Specifically, it stores genotyping data and single-nucleotide polymorphism (SNP) annotations along with study design data in an Oracle database. It also integrates popular genetic analysis tools, such as PLINK and Haploview. SNPTrack provides genetic analysis capabilities and captures analysis results in its database as SNP lists that can be cross-linked for biological interpretation to gene/protein annotations, Gene Ontology, and pathway analysis data. With SNPTrack, users can do the entire stream of bioinformatics jobs for genetic association studies. SNPTrack is freely available to the public at http://www.fda.gov/ScienceResearch/BioinformaticsTools/SNPTrack/default.htm. PMID:23245293

  4. Genetically Engineered Mouse Models for Studying Inflammatory Bowel Disease

    PubMed Central

    Mizoguchi, Atsushi; Takeuchi, Takahito; Himuro, Hidetomo; Okada, Toshiyuki; Mizoguchi, Emiko

    2015-01-01

    Inflammatory bowel disease (IBD) is a chronic intestinal inflammatory condition that is mediated by very complex mechanisms controlled by genetic, immune, and environmental factors. More than 74 kinds of genetically engineered mouse strains have been established since 1993 for studying IBD. Although mouse models cannot fully reflect human IBD, they have provided significant contributions for not only understanding the mechanism, but also developing new therapeutic means for IBD. Indeed, 20 kinds of genetically engineered mouse models carry the susceptibility genes identified in human IBD, and the functions of some other IBD susceptibility genes have also been dissected out using mouse models. Cutting-edge technologies such as cell-specific and inducible knockout systems, which were recently employed to mouse IBD models, have further enhanced the ability of investigators to provide important and unexpected rationales for developing new therapeutic strategies for IBD. In this review article, we briefly introduce 74 kinds of genetically engineered mouse models that spontaneously develop intestinal inflammation. PMID:26387641

  5. Molecular Genetic Strategies in the Study of Corticohippocampal Circuits.

    PubMed

    Angelakos, Christopher C; Abel, Ted

    2015-07-01

    The first reproductively viable genetically modified mice were created in 1982 by Richard Palmiter and Ralph Brinster (Palmiter RD, Brinster RL, Hammer RE, Trumbauer ME, Rosenfeld MG, Birnberg NC, Evans RM. 1982. Dramatic growth of mice that develop from eggs microinjected with metallothionein-growth hormone fusion genes. Nature 300: 611-615). In the subsequent 30 plus years, numerous ground-breaking technical advancements in genetic manipulation have paved the way for improved spatially and temporally targeted research. Molecular genetic studies have been especially useful for probing the molecules and circuits underlying how organisms learn and remember—one of the most interesting and intensively investigated questions in neuroscience research. Here, we discuss selected genetic tools, focusing on corticohippocampal circuits and their implications for understanding learning and memory. PMID:26134320

  6. Deaf Adults' Reasons for Genetic Testing Depend on Cultural Affiliation: Results from a Prospective, Longitudinal Genetic Counseling and Testing Study

    ERIC Educational Resources Information Center

    Boudreault, Patrick; Baldwin, Erin E.; Fox, Michelle; Dutton, Loriel; Tullis, LeeElle; Linden, Joyce; Kobayashi, Yoko; Zhou, Jin; Sinsheimer, Janet S.; Sininger, Yvonne; Grody, Wayne W.; Palmer, Christina G. S.

    2010-01-01

    This article examines the relationship between cultural affiliation and deaf adults' motivations for genetic testing for deafness in the first prospective, longitudinal study to examine the impact of genetic counseling and genetic testing on deaf adults and the deaf community. Participants (n = 256), classified as affiliating with hearing, Deaf,…

  7. Genetic Counseling for Indigenous Australians: an Exploratory Study from the Perspective of Genetic Health Professionals.

    PubMed

    Kowal, Emma; Gallacher, Lyndon; Macciocca, Ivan; Sahhar, Margaret

    2015-08-01

    Indigenous populations are thought to have particularly low levels of access to genetic health services, and cultural issues may be a contributing factor. This article presents the findings of the first study of genetic health service provision to Indigenous Australians. This qualitative study aimed to identify elements of culturally-competent genetic health service provision in Indigenous Australian contexts. Twelve semi-structured interviews were conducted with genetic counselors and clinical geneticists from around Australia who had delivered services to Indigenous Australians. Participants were asked to describe their experiences and identify any collective cultural needs of Indigenous clients, as well as comment on specific training and resources they had received or used. Interviews were audio-recorded and transcribed with thematic analysis conducted on the data. The findings show that participants were reluctant to generalize the needs of Indigenous peoples. Some participants asserted that Indigenous peoples have needs that differ from the general population, while others felt that there were no collective cultural needs, instead advocating an individualized approach. Being flexible and practical, taking time to build rapport, recognizing different family structures and decision-making processes, as well as socio-economic disadvantage were all identified as important factors in participants' interactions with Indigenous clients. Indigenous support workers and hospital liaison officers were seen as valuable resources for effective service provision. The implications of this study for training and practice are discussed. PMID:25348084

  8. Additional Treatments Offer Little Benefit for Pancreatic Cancer: Study

    MedlinePlus

    ... of gastroenterology-pancreatology at Beaujon Hospital, in Clichy, France. The study was funded by the pharmaceutical company ... D., department of gastroenterology-pancreatology, Beaujon Hospital, Clichy, France; Deborah Schrag, M.D., M.P.H., chief ...

  9. NMR relaxometry study of plaster mortar with polymer additives

    SciTech Connect

    Jumate, E.; Manea, D.; Moldovan, D.; Fechete, R.

    2013-11-13

    The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.

  10. Consent for genetic research in the Framingham Heart Study.

    PubMed

    Levy, Daniel; Splansky, Greta Lee; Strand, Nicolle K; Atwood, Larry D; Benjamin, Emelia J; Blease, Susan; Cupples, L Adrienne; D'Agostino, Ralph B; Fox, Caroline S; Kelly-Hayes, Margaret; Koski, Greg; Larson, Martin G; Mutalik, Karen M; Oberacker, Elizabeth; O'Donnell, Christopher J; Sutherland, Patrice; Valentino, Maureen; Vasan, Ramachandran S; Wolf, Philip A; Murabito, Joanne M

    2010-05-01

    Extensive efforts have been aimed at understanding the genetic underpinnings of complex diseases that affect humans. Numerous genome-wide association studies have assessed the association of genes with human disease, including the Framingham Heart Study (FHS), which genotyped 550,000 SNPs in 9,000 participants. The success of such efforts requires high rates of consent by participants, which is dependent on ethical oversight, communications, and trust between research participants and investigators. To study this we calculated percentages of participants who consented to collection of DNA and to various uses of their genetic information in two FHS cohorts between 2002 and 2009. The data included rates of consent for providing a DNA sample, creating an immortalized cell line, conducting research on various genetic conditions including those that might be considered sensitive, and for notifying participants of clinically significant genetic findings were above 95%. Only with regard to granting permission to share DNA or genetic findings with for-profit companies was the consent rate below 95%. We concluded that the FHS has maintained high rates of retention and consent for genetic research that has provided the scientific freedom to establish collaborations and address a broad range of research questions. We speculate that our high rates of consent have been achieved by establishing frequent and open communications with participants that highlight extensive oversight procedures. Our approach to maintaining high consent rates via ethical oversight of genetic research and communication with study participants is summarized in this report and should be of help to other studies engaged in similar types of research. Published 2010 Wiley-Liss, Inc. PMID:20425830

  11. NCI launches largest-ever study of breast cancer genetics in black women

    Cancer.gov

    The Breast Cancer Genetic Study in African-Ancestry Populations initiative is a collaborative research project that will identify genetic factors that may underlie breast cancer disparities. It is the largest study ever to investigate how genetic and biol

  12. The expanding phenotypic spectra of kidney diseases: insights from genetic studies.

    PubMed

    Stokman, Marijn F; Renkema, Kirsten Y; Giles, Rachel H; Schaefer, Franz; Knoers, Nine V A M; van Eerde, Albertien M

    2016-08-01

    Next-generation sequencing (NGS) has led to the identification of previously unrecognized phenotypes associated with classic kidney disease genes. In addition to improving diagnostics for genetically heterogeneous diseases and enabling a faster rate of gene discovery, NGS has enabled an expansion and redefinition of nephrogenetic disease categories. Findings from these studies raise the question of whether disease diagnoses should be made on clinical grounds, on genetic evidence or a combination thereof. Here, we discuss the major kidney disease-associated genes and gene categories for which NGS has expanded the phenotypic spectrum. For example, COL4A3-5 genes, which are classically associated with Alport syndrome, are now understood to also be involved in the aetiology of focal segmental glomerulosclerosis. DGKE, which is associated with nephrotic syndrome, is also mutated in patients with atypical haemolytic uraemic syndrome. We examine how a shared genetic background between diverse clinical phenotypes can provide insight into the function of genes and novel links with essential pathophysiological mechanisms. In addition, we consider genetic and epigenetic factors that contribute to the observed phenotypic heterogeneity of kidney diseases and discuss the challenges in the interpretation of genetic data. Finally, we discuss the implications of the expanding phenotypic spectra associated with kidney disease genes for clinical practice, genetic counselling and personalized care, and present our recommendations for the use of NGS-based tests in routine nephrology practice. PMID:27374918

  13. Genetic disorders in children and young adults: a population study.

    PubMed Central

    Baird, P A; Anderson, T W; Newcombe, H B; Lowry, R B

    1988-01-01

    The data base of an ongoing population-based registry with multiple sources of ascertainment was used to estimate the present population load from genetic disease in more than 1 million consecutive live births. It was found that, before approximately age 25 years, greater than or equal to 53/1,000 live-born individuals can be expected to have diseases with an important genetic component. This total was composed of single-gene disorders (3.6/1,000), consisting of autosomal dominant (1.4/1,000), autosomal recessive (1.7/1,000), and X-linked recessive disorders (0.5/1,000). Chromosomal anomalies accounted for 1.8/1,000, multifactorial disorders (including those present at birth and those of onset before age 25 years) accounted for 46.4/1,000, and cases of genetic etiology in which the precise mechanism was not identified accounted for 1.2/1,000. Previous studies have usually considered all congenital anomalies (ICD 740-759) as part of the genetic load, but only those judged to fit into one of the above categories were included in the present study. Data for congenital anomalies are therefore also presented separately, to facilitate comparison with earlier studies. If all congenital anomalies are considered as part of the genetic load, then greater than or equal to 79/1,000 live-born individuals have been identified as having one or other genetic disorder before approximately age 25 years. These new data represent a better estimate of the genetic load in the population than do previous studies. PMID:3358420

  14. Additional EIPC Study Analysis: Interim Report on High Priority Topics

    SciTech Connect

    Hadley, Stanton W

    2013-11-01

    Between 2010 and 2012 the Eastern Interconnection Planning Collaborative (EIPC) conducted a major long-term resource and transmission study of the Eastern Interconnection (EI). With guidance from a Stakeholder Steering Committee (SSC) that included representatives from the Eastern Interconnection States Planning Council (EISPC) among others, the project was conducted in two phases. Phase 1 involved a long-term capacity expansion analysis that involved creation of eight major futures plus 72 sensitivities. Three scenarios were selected for more extensive transmission- focused evaluation in Phase 2. Five power flow analyses, nine production cost model runs (including six sensitivities), and three capital cost estimations were developed during this second phase. The results from Phase 1 and 2 provided a wealth of data that could be examined further to address energy-related questions. A list of 13 topics was developed for further analysis; this paper discusses the first five.

  15. Does Childhood Anxiety Evoke Maternal Control? A Genetically Informed Study

    ERIC Educational Resources Information Center

    Eley, Thalia C.; Napolitano, Maria; Lau, Jennifer Y. F.; Gregory, Alice M.

    2010-01-01

    Background: Despite theoretical and empirical support for an association between maternal control and child anxiety, few studies have examined the origins of this association. Furthermore, none use observer-ratings of maternal control within a genetically informative design. This study addressed three questions: 1) do children who experience…

  16. Genetic linkage study of bipolar disorder and the serotonin transporter

    SciTech Connect

    Kelsoe, J.R.; Morison, M.; Mroczkowski-Parker, Z.; Bergesch, P.; Rapaport, M.H.; Mirow, A.L.

    1996-04-09

    The serotonin transporter (HTT) is an important candidate gene for the genetic transmission of bipolar disorder. It is the site of action of many antidepressants, and plays a key role in the regulation of serotonin neurotransmission. Many studies of affectively ill patients have found abnormalities in serotonin metabolism, and dysregulation of the transporter itself. The human serotonin transporter has been recently cloned and mapped to chromosome 17. We have identified a PstI RFLP at the HTT locus, and here report our examination of this polymorphism for possible linkage to bipolar disorder. Eighteen families were examined from three populations: the Old Order Amish, Iceland, and the general North American population. In addition to HTT, three other microsatellite markers were examined, which span an interval known to contain HTT. Linkage analyses were conducted under both dominant and recessive models, as well as both narrow (bipolar only) and broad (bipolar + recurrent unipolar) diagnostic models. Linkage could be excluded to HTT under all models examined. Linkage to the interval spanned by the microsatellites was similarly excluded under the dominant models. In two individual families, maximum lod scores of 1.02 and 0.84 were obtained at D17S798 and HTT, respectively. However, these data overall do not support the presence of a susceptibility locus for bipolar disorder near the serotonin transporter. 20 refs., 2 tabs.

  17. Stoppage Rules and Genetic Studies of Autism.

    ERIC Educational Resources Information Center

    Jones, Marshall B.; Szatmari, Peter

    1988-01-01

    "Stoppage rules" (responses of parents to the question of having more children when a child has been born seriously handicapped) are discussed. The paper shows that application of stoppage rules to a recent study of 46 families shows that the segregation ratio was underestimated in the original report. (Author/DB)

  18. Genetic and environmental influences on disordered eating: An adoption study.

    PubMed

    Klump, Kelly L; Suisman, Jessica L; Burt, S Alexandra; McGue, Matt; Iacono, William G

    2009-11-01

    Twin studies indicate significant genetic, but little shared environmental, influences on eating disorders. However, critics argue that study limitations constrain the conclusions that can be drawn. Adoption studies avoid many of these limitations, but to date, no adoption studies of eating pathology have been conducted. The current study was the first adoption study to examine genetic/environmental effects for disordered eating. Participants included 123 adopted and 56 biological female sibling pairs. Disordered eating (i.e., overall eating pathology, body dissatisfaction, weight preoccupation, binge eating) was assessed with the Minnesota Eating Behaviors Survey (Klump, McGue, & Iacono, 2000; von Ranson, Klump, Iacono, & McGue, 2005). Biometric model fitting indicated significant genetic influences (59%-82%) on all forms of disordered eating, with nonshared environmental factors accounting for the remaining variance. Shared environmental factors did not contribute significantly to any disordered eating symptom. Our findings bolster those from twin studies and provide critical evidence of significant genetic effects on disordered eating symptoms. PMID:19899849

  19. Why Is Studying the Genetics of Intelligence So Controversial?

    PubMed

    Tabery, James

    2015-01-01

    From the very beginning, studies of the nature and nurture of intelligence have been closely associated with an interest in intervening, and those interventions have been surrounded by controversy. The nature of those controversies has not always been the same, however. Since the mid-nineteenth century, when Francis Galton imagined a science that would assess the extent to which a trait like "genius" was due to nature or due to nurture, science and technology have changed dramatically, and so have the interventions that have been envisioned in light of those developments. A scientist today can search for particular stretches of DNA and assess whether differences in those stretches are associated with differences in a human trait of interest; a genetic counselor today can genetically test an individual (be it an embryo, fetus, newborn, child, or adult) and provide information about what that genetic result means, allowing for interventions that can range from terminating a pregnancy to prescribing chemotherapy. So when one asks a question like, "Why is studying the genetics of intelligence controversial?," it is important to realize up front that the answer will be, "It can be controversial for a variety of different reasons, and those reasons have evolved over time." The purpose of this essay is to provide a survey of the controversies that surround genetic studies of intelligence. With the survey in place, I will then draw out several lessons both for scientists who study the genetics of intelligence as well as for science studies scholars (bioethicists, philosophers, historians, sociologists) who reflect and comment on the controversies surrounding that research. PMID:26413953

  20. Sequencing studies in human genetics: design and interpretation

    PubMed Central

    Goldstein, David B.; Allen, Andrew; Keebler, Jonathan; Margulies, Elliott H.; Petrou, Steven; Petrovski, Slavé; Sunyaev, Shamil

    2014-01-01

    Next-gene ration sequencing is becoming the primary discovery tool in human genetics. There have been many clear successes in identifying genes that are responsible for Mendelian diseases, and sequencing approaches are now poised to identify the mutations that cause undiagnosed childhood genetic diseases and those that predispose individuals to more common complex diseases. There are, however, growing concerns that the complexity and magnitude of complete sequence data could lead to an explosion of weakly justified claims of association between genetic variants and disease. Here, we provide an overview of the basic workflow in next-generation sequencing studies and emphasize, where possible, measures and considerations that facilitate accurate inferences from human sequencing studies. PMID:23752795

  1. Reverse Genetics System for Studying Human Rhinovirus Infections

    PubMed Central

    Lee, Wai-Ming; Wang, Wensheng; Bochkov, Yury A; Lee, Iris

    2015-01-01

    SUMMARY Human rhinovirus (HRV) contains a 7.2 Kb messenger-sense RNA genome which is the template for reproducing progeny viruses after it enters the cytoplasm of a host cell. Reverse genetics refers to the regeneration of progeny viruses from an artificial cDNA copy of the RNA genome of an RNA virus. It has been a powerful molecular genetic tool for studying HRV and other RNA viruses because the artificial DNA stage makes it practical to introduce specific mutations into the viral RNA genome. This chapter uses HRV-16 as the model virus to illustrate the strategy and the methods for constructing and cloning the artificial cDNA copy of a full-length HRV genome, identifying the infectious cDNA clone isolates, and selecting the most vigorous cDNA clone isolate to serve as the standard parental clone for future molecular genetic study of the virus. PMID:25261313

  2. Dioecy, more than monoecy, affects plant spatial genetic structure: the case study of Ficus

    PubMed Central

    Nazareno, Alison G; Alzate-Marin, Ana L; Pereira, Rodrigo Augusto S

    2013-01-01

    In this analysis, we attempt to understand how monoecy and dioecy drive spatial genetic structure (SGS) in plant populations. For this purpose, plants of the genus Ficus were used as a comparative model due to their particular characteristics, including high species diversity, variation in life histories, and sexual systems. One of the main issues we assessed is whether dioecious fig tree populations are more spatially genetically structured than monoecious populations. Using the Sp statistic, which allows for quantitative comparisons among different studies, we compared the extent of SGS between monoecious and dioecious Ficus species. To broaden our conclusions we used published data on an additional 27 monoecious and dioecious plant species. Furthermore, genetic diversity analyses were performed for two monoecious Ficus species using 12 microsatellite markers in order to strengthen our conclusions about SGS. Our results show that dioecy, more than monoecy, significantly contributes to SGS in plant populations. On average, the estimate of Sp was six times higher for dioecious Ficus species than monoecious Ficus species and it was two times higher in dioecious than monoecious plant species. Considering these results, we emphasize that the long-distance pollen dispersal mechanism in monoecious Ficus species seems to be the dominant factor in determining weak spatial genetic structure, high levels of genetic diversity, and lack of inbreeding. Although Ficus constitute a model species to study SGS, a more general comparison encompassing a wider range of plants is required in order to better understand how sexual systems affect genetic structure. PMID:24223285

  3. Genetic studies of Crohn's disease: Past, present and future

    PubMed Central

    Liu, Jimmy Z.; Anderson, Carl A.

    2014-01-01

    The exact aetiology of Crohn's disease is unknown, though it is clear from early epidemiological studies that a combination of genetic and environmental risk factors contributes to an individual's disease susceptibility. Here, we review the history of gene-mapping studies of Crohn's disease, from the linkage-based studies that first implicated the NOD2 locus, through to modern-day genome-wide association studies that have discovered over 140 loci associated with Crohn's disease and yielded novel insights into the biological pathways underlying pathogenesis. We describe on-going and future gene-mapping studies that utilise next generation sequencing technology to pinpoint causal variants and identify rare genetic variation underlying Crohn's disease risk. We comment on the utility of genetic markers for predicting an individual's disease risk and discuss their potential for identifying novel drug targets and influencing disease management. Finally, we describe how these studies have shaped and continue to shape our understanding of the genetic architecture of Crohn's disease. PMID:24913378

  4. [Studies on genetic relationship of Dioscorea].

    PubMed

    Huang, Han-han; Li, Xia; Gao, Wen-yuan; Xiao, Pei-gen

    2015-09-01

    Based on the results of the morphologic studies on genus Dioscorea, the paper summarized the entire chemical constituent that isolated from this genus and analyzed it with the methods of chemotaxonomy. The rules of the chemical constituent and pharmacodynamic effects were analyzed. Seventeen species which belong to Sect. Stenophora Uline of Dioscorea contain steroidal sapogenin. Other species with different main components such as polysaccharide and tannin have have different effects. This chemotaxonomic view point will conduce to establish a phylogeny of the genus Dioscorea. PMID:26978991

  5. The Utility of Breastmilk for Genetic or Genomic Studies: A Systematic Review

    PubMed Central

    Conley, Yvette P.

    2013-01-01

    Abstract This study synthesized scientific literature that applies genetic or genomic approaches to breastmilk. A literature search of PubMed was conducted in March 2012 using the key words "breast milk," "lactation," "genetic," "gene expression," and "epigenetic." Additional articles were identified/selected for evaluation with MeSH term searches, and a review of article reference lists was obtained from the search. The initial 657 abstracts retrieved from the literature search were reviewed, and 16 studies were selected for evaluation. Studies that examined the transmission of viruses/bacteria into breastmilk and/or measured concentration of specific proteins without examination of genetic material from milk were excluded. Data related to subjects, tissue, purpose, setting, gene/protein, approach (candidate versus genome-wide), platform, statistical analysis, and results were extracted. Gene expression and epigenetic/epigenomic study designs have been successfully implemented using breastmilk. A major weakness of both gene expression studies and epigenetic studies that examine breastmilk is the omission of maternal information known to influence milk composition. This review article is the first to synthesize evidence related to the application of breastmilk to evaluate RNA and epigenetic modifications. Additional research is needed that applies epigenetic analyses to human breastmilk samples. Findings from this review can be used for future research designs that use breastmilk for genetic analyses. PMID:23259645

  6. Potential Genetic Risk Factors for Chronic TMD: Genetic Associations from the OPPERA Case Control Study

    PubMed Central

    Smith, Shad B.; Maixner, Dylan; Greenspan, Joel; Dubner, Ron; Fillingim, Roger; Ohrbach, Richard; Knott, Charles; Slade, Gary; Bair, Eric; Gibson, Dustin G.; Zaykin, Dmitri V.; Weir, Bruce; Maixner, William; Diatchenko, Luda

    2011-01-01

    Genetic factors play a role in the etiology of persistent pain conditions, putatively by modulating underlying processes such as nociceptive sensitivity, psychological well-being, inflammation, and autonomic response. However, to date, only a few genes have been associated with temporomandibular disorders (TMD). This study evaluated 358 genes involved in pain processes, comparing allelic frequencies between 166 cases with chronic TMD and 1442 controls enrolled in the OPPERA (Orofacial Pain: Prospective Evaluation and Risk Assessment) study cooperative agreement. To enhance statistical power, 182 TMD cases and 170 controls from a similar study were included in the analysis. Genotyping was performed using the Pain Research Panel, an Affymetrix gene chip representing 3295 single nucleotide polymorphisms, including ancestry-informative markers that were used to adjust for population stratification. Adjusted associations between genetic markers and TMD case status were evaluated using logistic regression. The OPPERA findings provided evidence supporting previously-reported associations between TMD and two genes: HTR2A and COMT. Other genes were revealed as potential new genetic risk factors for TMD, including NR3C1, CAMK4, CHRM2, IFRD1, and GRK5. While these findings need to be replicated in independent cohorts, the genes potentially represent important markers of risk for TMD and they identify potential targets for therapeutic intervention. PMID:22074755

  7. Power assessment for genetic association study of human longevity using offspring of long-lived subjects

    PubMed Central

    Zhao, Jing Hua; Li, Shuxia; Kruse, Torben A.; Christensen, Kaare

    2010-01-01

    Recently, an indirect genetic association approach that compares genotype frequencies in offspring of long-lived subjects and offspring from random families has been introduced to study gene-longevity associations. Although the indirect genetic association has certain advantages over the direct association approach that compares genotype frequency between centenarians and young controls, the power has been of concern. This paper reports a power study performed on the indirect approach using computer simulation. We perform our simulation study by introducing the current Danish population life table and the proportional hazard model for generating individual lifespan. Family genotype data is generated using a genetic linkage program for given SNP allele frequency. Power is estimated by setting the type I error rate at 0.05 and by calculating the Armitage’s chi-squared test statistic for 200 replicate samples for each setting of the specified allele risk and frequency parameters under different modes of inheritance and for different sample sizes. The indirect genetic association analysis is a valid approach for studying gene-longevity association, but the sample size requirement is about 3–4 time larger than the direct approach. It also has low power in detecting non-additive effect genes. Indirect genetic association using offspring from families with both parents as nonagenarians is nearly as powerful as using offspring from families with one centenarian parent. In conclusion, the indirect design can be a good choice for studying longevity in comparison with other alternatives, when relatively large sample size is available. PMID:20512403

  8. Genetics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maintaining genetic variation in wild populations of Arctic organisms is fundamental to the long-term persistence of high latitude biodiversity. Variability is important because it provides options for species to respond to changing environmental conditions and novel challenges such as emerging path...

  9. Zebrafish: A Model for the Study of Addiction Genetics

    PubMed Central

    Klee, Eric W; Schneider, Henning; Clark, Karl; Cousin, Margot; Ebbert, Jon; Hooten, Michael; Karpyak, Victor; Warner, David; Ekker, Stephen

    2013-01-01

    Drug abuse and dependence are multifaceted disorders with complex genetic underpinnings. Identifying specific genetic correlates is challenging and may be more readily accomplished by defining endophenotypes specific for addictive disorders. Symptoms and syndromes, including acute drug response, consumption, preference, and withdrawal, are potential endophenotypes characterizing addiction that have been investigated using model organisms. We present a review of major genes involved in serotonergic, dopaminergic, GABAergic, and adrenoreceptor signaling that are considered to be directly involved in nicotine, opioid, cannabinoid, and ethanol use and dependence. The zebrafish genome encodes likely homologs of the vast majority of these loci. We also review the known expression patterns of these genes in zebrafish. The information presented in this review provides support for the use of zebrafish as a viable model for studying genetic factors related to drug addiction. Expansion of investigations into drug response using model organisms holds the potential to advance our understanding of drug response and addiction in humans. PMID:22207143

  10. Applications of Molecular Genetics to the Study of Asthma.

    PubMed

    Sanz-Lozano, Catalina S; García-Solaesa, Virginia; Davila, Ignacio; Isidoro-García, María

    2016-01-01

    Asthma is a multifactorial disease. This fact, associated to the diversity of asthma phenotypes, has made difficult to obtain a clear pattern of inheritance. With the huge development of molecular genetics technologies, candidate gene studies are giving way to different types of studies from the genomic point of view.These approaches are allowing the identification of several genes associated with asthma. However, in these studies, there are some conflicting results between different populations and there is still a lack of knowledge about the actual influence of the gene variants. Some confounding factors are, among others, the inappropriate sample size, population stratification, differences in the classification of the phenotypes, or inadequate coverage of the genes.To confirm the real effect of the reported associations, it is necessary to consider both the genetic and environmental factors and perform functional studies that explain the molecular mechanisms mediating between the emergence of gene variants and the development of the disease.The development of experimental techniques opens a new horizon that allows the identification of major genetic factors of susceptibility to asthma. The resulting classification of the population groups based on their genetic characteristics, will allow the application of specific and highly efficient treatments. PMID:27300527

  11. GESDB: a platform of simulation resources for genetic epidemiology studies.

    PubMed

    Yao, Po-Ju; Chung, Ren-Hua

    2016-01-01

    Computer simulations are routinely conducted to evaluate new statistical methods, to compare the properties among different methods, and to mimic the observed data in genetic epidemiology studies. Conducting simulation studies can become a complicated task as several challenges can occur, such as the selection of an appropriate simulation tool and the specification of parameters in the simulation model. Although abundant simulated data have been generated for human genetic research, currently there is no public database designed specifically as a repository for these simulated data. With the lack of such a database, for similar studies, similar simulations may have been repeated, which resulted in redundant work. Thus, we created an online platform, the Genetic Epidemiology Simulation Database (GESDB), for simulation data sharing and discussion of simulation techniques for genetic epidemiology studies. GESDB consists of a database for storing simulation scripts, simulated data and documentation from published articles as well as a discussion forum, which provides a platform for discussion of the simulated data and exchanging simulation ideas. Moreover, summary statistics such as the simulation tools that are most commonly used and datasets that are most frequently downloaded are provided. The statistics will be informative for researchers to choose an appropriate simulation tool or select a common dataset for method comparisons. GESDB can be accessed at http://gesdb.nhri.org.twDatabase URL: http://gesdb.nhri.org.tw. PMID:27242038

  12. Involving study populations in the review of genetic research.

    PubMed

    Sharp, R R; Foster, M W

    2000-01-01

    Genetic research can present risks to all members of a study population, not just those who choose to participate in research. The authors suggest that community-based reviews of research protocols can help identify and minimize such research-related risks. PMID:11067631

  13. GENETICAL METABOLOMICS OF FLAVONOID BIOSYNTHESIS IN POPULUS: A CASE STUDY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetical metabolomics (metabolite profiling combined with quantitative trait locus [QTL] analysis) is proposed as a new tool to identify loci that control metabolite abundances. This concept was evaluated in a case study with the model tree Populus. By using HPLC, the peak abundances were analyzed ...

  14. GESDB: a platform of simulation resources for genetic epidemiology studies

    PubMed Central

    Yao, Po-Ju; Chung, Ren-Hua

    2016-01-01

    Computer simulations are routinely conducted to evaluate new statistical methods, to compare the properties among different methods, and to mimic the observed data in genetic epidemiology studies. Conducting simulation studies can become a complicated task as several challenges can occur, such as the selection of an appropriate simulation tool and the specification of parameters in the simulation model. Although abundant simulated data have been generated for human genetic research, currently there is no public database designed specifically as a repository for these simulated data. With the lack of such a database, for similar studies, similar simulations may have been repeated, which resulted in redundant work. Thus, we created an online platform, the Genetic Epidemiology Simulation Database (GESDB), for simulation data sharing and discussion of simulation techniques for genetic epidemiology studies. GESDB consists of a database for storing simulation scripts, simulated data and documentation from published articles as well as a discussion forum, which provides a platform for discussion of the simulated data and exchanging simulation ideas. Moreover, summary statistics such as the simulation tools that are most commonly used and datasets that are most frequently downloaded are provided. The statistics will be informative for researchers to choose an appropriate simulation tool or select a common dataset for method comparisons. GESDB can be accessed at http://gesdb.nhri.org.tw. Database URL: http://gesdb.nhri.org.tw PMID:27242038

  15. Cerebrospinal fluid APOE levels: an endophenotype for genetic studies for Alzheimer's disease

    PubMed Central

    Cruchaga, Carlos; Kauwe, John S.K.; Nowotny, Petra; Bales, Kelly; Pickering, Eve H.; Mayo, Kevin; Bertelsen, Sarah; Hinrichs, Anthony; Fagan, Anne M.; Holtzman, David M.; Morris, John C.; Goate, Alison M.

    2012-01-01

    The apolipoprotein E (APOE) genotype is the major genetic risk factor for Alzheimer's disease (AD). We have access to cerebrospinal fluid (CSF) and plasma APOE protein levels from 641 individuals and genome-wide genotyped data from 570 of these samples. The aim of this study was to test whether CSF or plasma APOE levels could be a useful endophenotype for AD and to identify genetic variants associated with APOE levels. We found that CSF (P = 8.15 × 10−4) but not plasma (P = 0.071) APOE protein levels are significantly associated with CSF Aβ42 levels. We used Mendelian randomization and genetic variants as instrumental variables to confirm that the association of CSF APOE with CSF Aβ42 levels and clinical dementia rating (CDR) is not because of a reverse causation or confounding effect. In addition the association of CSF APOE with Aβ42 levels was independent of the APOE ɛ4 genotype, suggesting that APOE levels in CSF may be a useful endophenotype for AD. We performed a genome-wide association study to identify genetic variants associated with CSF APOE levels: the APOE ɛ4 genotype was the strongest single-genetic factor associated with CSF APOE protein levels (P = 6.9 × 10−13). In aggregate, the Illumina chip single nucleotide polymorphisms explain 72% of the variability in CSF APOE protein levels, whereas the APOE ɛ4 genotype alone explains 8% of the variability. No other genetic variant reached the genome-wide significance threshold, but nine additional variants exhibited a P-value <10−6. Pathway mining analysis indicated that these nine additional loci are involved in lipid metabolism (P = 4.49 × 10−9). PMID:22821396

  16. Genetic studies on the Cayo Santiago rhesus macaques: A review of 40 years of research.

    PubMed

    Widdig, Anja; Kessler, Matthew J; Bercovitch, Fred B; Berard, John D; Duggleby, Christine; Nürnberg, Peter; Rawlins, Richard G; Sauermann, Ulrike; Wang, Qian; Krawczak, Michael; Schmidtke, Jörg

    2016-01-01

    Genetic studies not only contribute substantially to our current understanding of the natural variation in behavior and health in many species, they also provide the basis of numerous in vivo models of human traits. Despite the many challenges posed by the high level of biological and social complexity, a long lifespan and difficult access in the field, genetic studies of primates are particularly rewarding because of the close evolutionary relatedness of these species to humans. The free-ranging rhesus macaque (Macaca mulatta) population on Cayo Santiago (CS), Puerto Rico, provides a unique resource in this respect because several of the abovementioned caveats are of either minor importance there, or lacking altogether, thereby allowing long-term genetic research in a primate population under constant surveillance since 1956. This review summarizes more than 40 years of genetic research carried out on CS, from early blood group typing and the genetic characterization of skeletal material via population-wide paternity testing with DNA fingerprints and short tandem repeats (STRs) to the analysis of the highly polymorphic DQB1 locus within the major histocompatibility complex (MHC). The results of the paternity studies also facilitated subsequent studies of male dominance and other factors influencing male reproductive success, of male reproductive skew, paternal kin bias, and mechanisms of paternal kin recognition. More recently, the CS macaques have been the subjects of functional genetic and gene expression analyses and have played an important role in behavioral and quantitative genetic studies. In addition, the CS colony has been used as a natural model for human adult-onset macular degeneration, glaucoma, and circadian rhythm disorder. Our review finishes off with a discussion of potential future directions of research on CS, including the transition from STRs to single nucleotide polymorphism (SNP) typing and whole genome sequencing. PMID:26031601

  17. Common psychiatric disorders share the same genetic origin: a multivariate sibling study of the Swedish population.

    PubMed

    Pettersson, E; Larsson, H; Lichtenstein, P

    2016-05-01

    Recent studies have shown that different mental-health problems appear to be partly influenced by the same set of genes, which can be summarized by a general genetic factor. To date, such studies have relied on surveys of community-based samples, which could introduce potential biases. The goal of this study was to examine whether a general genetic factor would still emerge when based on a different ascertainment method with different biases from previous studies. We targeted all adults in Sweden (n=3 475 112) using national registers and identified those who had received one or more psychiatric diagnoses after seeking or being forced into mental health care. In order to examine the genetic versus environmental etiology of the general factor, we examined whether participants' full- or half-siblings had also received diagnoses. We focused on eight major psychiatric disorders based on the International Classification of Diseases, including schizophrenia, schizoaffective disorder, bipolar disorder, depression, anxiety, attention-deficit/hyperactivity disorder, alcohol use disorder and drug abuse. In addition, we included convictions of violent crimes. Multivariate analyses demonstrated that a general genetic factor influenced all disorders and convictions of violent crimes, accounting for between 10% (attention-deficit/hyperactivity disorder) and 36% (drug abuse) of the variance of the conditions. Thus, a general genetic factor of psychopathology emerges when based on both surveys as well as national registers, indicating that a set of pleiotropic genes influence a variety of psychiatric disorders. PMID:26303662

  18. The genetic and environmental foundations of political, psychological, social, and economic behaviors: a panel study of twins and families.

    PubMed

    Hatemi, Peter K; Smith, Kevin; Alford, John R; Martin, Nicholas G; Hibbing, John R

    2015-06-01

    Here we introduce the Genetic and Environmental Foundations of Political and Economic Behaviors: A Panel Study of Twins and Families (PIs Alford, Hatemi, Hibbing, Martin, and Smith). This study was designed to explore the genetic and environmental influences on social, economic, and political behaviors and attitudes. It involves identifying the psychological mechanisms that operate on these traits, the heritability of complex economic and political traits under varying conditions, and specific genetic correlates of attitudes and behaviors. In addition to describing the study, we conduct novel analyses on the data, estimating the heritability of two traits so far unexplored in the extant literature: Machiavellianism and Baron-Cohen's Empathizing Quotient. PMID:25994545

  19. Study design in genetic epidemiology: theoretical and practical considerations.

    PubMed

    Whittemore, A S; Nelson, L M

    1999-01-01

    Recent advances in molecular genetics have created new opportunities and challenges for genetic epidemiologists. Here we review some of the issues that arise when designing a study involving the genetic epidemiology of chronic diseases of late onset, such as cancer. We discuss two considerations that influence the choice of design. The first consideration is the study's goals. We describe the goals of identifying new susceptibility genes for a disease, of estimating important characteristics of known genes, and of learning how to prevent the disease in the genetically susceptible. We indicate how these goals affect the choice of design and present some guidelines for choosing designs that effectively address them. The second consideration is the set of practical constraints to successfully conducting the research. These contraints include problems of potential selection bias, reduced response rates, problems particular to family registries, problems particular to the cultures of various ethnic groups, and ethical issues. We indicate how these constraints affect the choice of design and discuss ways to deal with them. PMID:10854488

  20. Matching Strategies for Genetic Association Studies in Structured Populations

    PubMed Central

    Hinds, David A.; Stokowski, Renee P.; Patil, Nila; Konvicka, Karel; Kershenobich, David; Cox, David R.; Ballinger, Dennis G.

    2004-01-01

    Association studies in populations that are genetically heterogeneous can yield large numbers of spurious associations if population subgroups are unequally represented among cases and controls. This problem is particularly acute for studies involving pooled genotyping of very large numbers of single-nucleotide–polymorphism (SNP) markers, because most methods for analysis of association in structured populations require individual genotyping data. In this study, we present several strategies for matching case and control pools to have similar genetic compositions, based on ancestry information inferred from genotype data for ∼300 SNPs tiled on an oligonucleotide-based genotyping array. We also discuss methods for measuring the impact of population stratification on an association study. Results for an admixed population and a phenotype strongly confounded with ancestry show that these simple matching strategies can effectively mitigate the impact of population stratification. PMID:14740319

  1. Association of Obesity-related Genetic Variants With Endometrial Cancer Risk: A Report From the Shanghai Endometrial Cancer Genetics Study

    PubMed Central

    Delahanty, Ryan J.; Beeghly-Fadiel, Alicia; Xiang, Yong-Bing; Long, Jirong; Cai, Qiuyin; Wen, Wanqing; Xu, Wang-Hong; Cai, Hui; He, Jing; Gao, Yu-Tang; Zheng, Wei; Shu, Xiao Ou

    2011-01-01

    Obesity is a well-established risk factor for endometrial cancer, the most common gynecologic malignancy. Recent genome-wide association studies (GWAS) have identified multiple genetic markers for obesity. The authors evaluated the association of obesity-related single nucleotide polymorphisms (SNPs) with endometrial cancer using GWAS data from their recently completed study, the Shanghai Endometrial Cancer Genetics Study, which comprised 832 endometrial cancer cases and 2,049 controls (1996–2005). Thirty-five SNPs previously associated with obesity or body mass index (BMI; weight (kg)/height (m)2) at a minimum significance level of ≤5 × 10−7 in the US National Human Genome Research Institute's GWAS catalog (http://genome.gov/gwastudies) and representing 26 unique loci were evaluated by either direct genotyping or imputation. The authors found that for 22 of the 26 unique loci tested (84.6%), the BMI-associated risk variants were present at a higher frequency in cases than in population controls (P = 0.0003). Multiple regression analysis showed that 9 of 35 BMI-associated variants, representing 7 loci, were significantly associated (P ≤ 0.05) with the risk of endometrial cancer; for all but 1 SNP, the direction of association was consistent with that found for BMI. For consistent SNPs, the allelic odds ratios ranged from 1.15 to 1.29. These 7 loci are in the SEC16B/RASAL, TMEM18, MSRA, SOX6, MTCH2, FTO, and MC4R genes. The associations persisted after adjustment for BMI, suggesting that genetic markers of obesity provide value in addition to BMI in predicting endometrial cancer risk. PMID:21976109

  2. Genetics of FTLD: overview and what else we can expect from genetic studies.

    PubMed

    Pottier, Cyril; Ravenscroft, Thomas A; Sanchez-Contreras, Monica; Rademakers, Rosa

    2016-08-01

    Frontotemporal lobar degeneration (FTLD) comprises a highly heterogeneous group of disorders clinically associated with behavioral and personality changes, language impairment, and deficits in executive functioning, and pathologically associated with degeneration of frontal and temporal lobes. Some patients present with motor symptoms including amyotrophic lateral sclerosis. Genetic research over the past two decades in FTLD families led to the identification of three common FTLD genes (microtubule-associated protein tau, progranulin, and chromosome 9 open reading frame 72) and a small number of rare FTLD genes, explaining the disease in almost all autosomal dominant FTLD families but only a minority of apparently sporadic patients or patients in whom the family history is less clear. Identification of additional FTLD (risk) genes is therefore highly anticipated, especially with the emerging use of next-generation sequencing. Common variants in the transmembrane protein 106 B were identified as a genetic risk factor of FTLD and disease modifier in patients with known mutations. This review summarizes for each FTLD gene what we know about the type and frequency of mutations, their associated clinical and pathological features, and potential disease mechanisms. We also provide an overview of emerging disease pathways encompassing multiple FTLD genes. We further discuss how FTLD specific issues, such as disease heterogeneity, the presence of an unclear family history and the possible role of an oligogenic basis of FTLD, can pose challenges for future FTLD gene identification and risk assessment of specific variants. Finally, we highlight emerging clinical, genetic, and translational research opportunities that lie ahead. Genetic research led to the identification of three common FTLD genes with rare variants (MAPT, GRN, and C9orf72) and a small number of rare genes. Efforts are now ongoing, which aimed at the identification of rare variants with high risk and/or low

  3. Comparative use of InDel and SSR markers in deciphering the interspecific structure of cultivated citrus genetic diversity: a perspective for genetic association studies.

    PubMed

    García-Lor, Andrés; Luro, François; Navarro, Luis; Ollitrault, Patrick

    2012-01-01

    Genetic stratification associated with domestication history is a key parameter for estimating the pertinence of genetic association study within a gene pool. Previous molecular and phenotypic studies have shown that most of the diversity of cultivated citrus results from recombination between three main species: C. medica (citron), C. reticulata (mandarin) and C. maxima (pummelo). However, the precise contribution of each of these basic species to the genomes of secondary cultivated species, such as C. sinensis (sweet orange), C. limon (lemon), C. aurantium (sour orange), C. paradisi (grapefruit) and recent hybrids is unknown. Our study focused on: (1) the development of insertion-deletion (InDel) markers and their comparison with SSR markers for use in genetic diversity and phylogenetic studies; (2) the analysis of the contributions of basic taxa to the genomes of secondary species and modern cultivars and (3) the description of the organisation of the Citrus gene pool, to evaluate how genetic association studies should be done at the cultivated Citrus gene pool level. InDel markers appear to be better phylogenetic markers for tracing the contributions of the three ancestral species, whereas SSR markers are more useful for intraspecific diversity analysis. Most of the genetic organisation of the Citrus gene pool is related to the differentiation between C. reticulata, C. maxima and C. medica. High and generalised LD was observed, probably due to the initial differentiation between the basic species and a limited number of interspecific recombinations. This structure precludes association genetic studies at the genus level without developing additional recombinant populations from interspecific hybrids. Association genetic studies should also be affordable at intraspecific level in a less structured pool such as C. reticulata. PMID:22160318

  4. Behavioral Genetic Contributions to the Study of Addiction-Related Amphetamine Effects

    PubMed Central

    Phillips, Tamara J.; Kamens, Helen M.; Wheeler, Jeanna M.

    2008-01-01

    Amphetamines, including methamphetamine, pose a significant cost to society due to significant numbers of amphetamine-abusing individuals who suffer major health-related consequences. In addition, methamphetamine use is associated with heightened rates of violent and property-related crimes. The current paper reviews the existing literature addressing genetic differences in mice that impact behavioral responses thought to be relevant to the abuse of amphetamine and amphetamine-like drugs. Summarized are studies that used inbred strains, selected lines, single gene knockouts and transgenics, and quantitative trait locus (QTL) mapping populations. Acute sensitivity, neuroadaptive responses, rewarding and conditioned effects are among those reviewed. Some gene mapping work has been accomplished, and although no amphetamine-related complex trait genes have been definitively identified, translational work leading from results in the mouse to studies performed in humans is beginning to emerge. The majority of genetic investigations has utilized single-gene knockout mice and has concentrated on dopamine- and glutamate-related genes. Genes that code for cell support and signaling molecules are also well-represented. There is a large behavioral genetic literature on responsiveness to amphetamines, but a considerably smaller literature focused on genes that influence the development and acceleration of amphetamine use, withdrawal, relapse, and behavioral toxicity. Also missing are genetic investigations into the effects of amphetamines on social behaviors. This information might help to identify at-risk individuals and in the future to develop treatments that take advantage of individualized genetic information. PMID:18207241

  5. A Genetically Informed Study of Associations between Family Functioning and Child Psychosocial Adjustment

    PubMed Central

    Schermerhorn, Alice C.; D’Onofrio, Brian M.; Turkheimer, Eric; Ganiban, Jody M.; Spotts, Erica L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

    2010-01-01

    Research has documented associations between family functioning and offspring psychosocial adjustment, but questions remain regarding whether these associations are partly due to confounding genetic factors and other environmental factors. The current study used a genetically informed approach, the Children of Twins design, to explore the associations between family functioning (family conflict, marital quality, and agreement about parenting) and offspring psychopathology. Participants were 867 twin pairs (388 MZ; 479 DZ) from the Twin and Offspring Study in Sweden (TOSS), their spouses, and children (51.7% female; M = 15.75 years). The results suggested associations between exposure to family conflict (assessed by the mother, father, and child) and child adjustment were independent of genetic factors and other environmental factors. However, when family conflict was assessed using only children’s reports, the results indicated that genetic factors also influenced these associations. In addition, the analyses indicated that exposure to low marital quality and agreement about parenting was associated with children’s internalizing and externalizing problems, and that genetic factors also contributed to the associations of marital quality and agreement about parenting with offspring externalizing problems. PMID:21142367

  6. A Global Population Genetic Study of Pantala flavescens

    PubMed Central

    Troast, Daniel; Suhling, Frank; Jinguji, Hiroshi; Sahlén, Göran; Ware, Jessica

    2016-01-01

    Among terrestrial arthropods, the dragonfly species Pantala flavescens is remarkable due to their nearly global distribution and extensive migratory ranges; the largest of any known insect. Capable of migrating across oceans, the potential for high rates of gene flow among geographically distant populations is significant. It has been hypothesized that P. flavescens may be a global panmictic population but no sufficient genetic evidence has been collected thus far. Through a population genetic analysis of P. flavescens samples from North America, South America, and Asia, the current study aimed to examine the extent at which gene flow is occurring on a global scale and discusses the implications of the genetic patterns we uncovered on population structure and genetic diversity of the species. This was accomplished using PCR-amplified cytochrome oxidase one (CO1) mitochondrial DNA data to reconstruct phylogenetic trees, a haplotype network, and perform molecular variance analyses. Our results suggested high rates of gene flow are occurring among all included geographic regions; providing the first significant evidence that Pantala flavescens should be considered a global panmictic population. PMID:26934181

  7. A Global Population Genetic Study of Pantala flavescens.

    PubMed

    Troast, Daniel; Suhling, Frank; Jinguji, Hiroshi; Sahlén, Göran; Ware, Jessica

    2016-01-01

    Among terrestrial arthropods, the dragonfly species Pantala flavescens is remarkable due to their nearly global distribution and extensive migratory ranges; the largest of any known insect. Capable of migrating across oceans, the potential for high rates of gene flow among geographically distant populations is significant. It has been hypothesized that P. flavescens may be a global panmictic population but no sufficient genetic evidence has been collected thus far. Through a population genetic analysis of P. flavescens samples from North America, South America, and Asia, the current study aimed to examine the extent at which gene flow is occurring on a global scale and discusses the implications of the genetic patterns we uncovered on population structure and genetic diversity of the species. This was accomplished using PCR-amplified cytochrome oxidase one (CO1) mitochondrial DNA data to reconstruct phylogenetic trees, a haplotype network, and perform molecular variance analyses. Our results suggested high rates of gene flow are occurring among all included geographic regions; providing the first significant evidence that Pantala flavescens should be considered a global panmictic population. PMID:26934181

  8. Rationale for an international consortium to study inherited genetic susceptibility to childhood acute lymphoblastic leukemia

    PubMed Central

    Sherborne, Amy L.; Hemminki, Kari; Kumar, Rajiv; Bartram, Claus R.; Stanulla, Martin; Schrappe, Martin; Petridou, Eleni; Semsei, Ágnes F.; Szalai, Csaba; Sinnett, Daniel; Krajinovic, Maja; Healy, Jasmine; Lanciotti, Marina; Dufour, Carlo; Indaco, Stefania; El-Ghouroury, Eman A; Sawangpanich, Ruchchadol; Hongeng, Suradej; Pakakasama, Samart; Gonzalez-Neira, Anna; Ugarte, Evelia L.; Leal, Valeria P.; Espinoza, Juan P.M.; Kamel, Azza M.; Ebid, Gamal T.A.; Radwan, Eman R.; Yalin, Serap; Yalin, Erdinc; Berkoz, Mehmet; Simpson, Jill; Roman, Eve; Lightfoot, Tracy; Hosking, Fay J.; Vijayakrishnan, Jayaram; Greaves, Mel; Houlston, Richard S.

    2011-01-01

    Acute lymphoblastic leukemia is the major pediatric cancer in developed countries. To date most association studies of acute lymphoblastic leukemia have been based on the candidate gene approach and have evaluated a restricted number of polymorphisms. Such studies have served to highlight difficulties in conducting statistically and methodologically rigorous investigations into acute lymphoblastic leukemia risk. Recent genome-wide association studies of childhood acute lymphoblastic leukemia have provided robust evidence that common variation at four genetic loci confers a modest increase in risk. The accumulated experience to date and relative lack of success of initial efforts to identify novel acute lymphoblastic leukemia predisposition loci emphasize the need for alternative study designs and methods. The International Childhood Acute Lymphoblastic Leukaemia Genetics Consortium includes 12 research groups in Europe, Asia, the Middle East and the Americas engaged in studying the genetics of acute lymphoblastic leukemia. The initial goal of this consortium is to identify and characterize low-penetrance susceptibility variants for acute lymphoblastic leukemia through association-based analyses. Efforts to develop genome-wide association studies of acute lymphoblastic leukemia, in terms of both sample size and single nucleotide polymorphism coverage, and to increase the number of single nucleotide polymorphisms taken forward to large-scale replication should lead to the identification of additional novel risk variants for acute lymphoblastic leukemia. Ethnic differences in the risk of acute lymphoblastic leukemia are well recognized and thus in assessing the interplay between inherited and non-genetic risk factors, analyses using different population cohorts with different incidence rates are likely to be highly informative. Given that the frequency of many acute lymphoblastic leukemia subgroups is small, identifying differential effects will realistically only be

  9. Spitting for Science: Danish High School Students Commit to a Large-Scale Self-Reported Genetic Study

    PubMed Central

    Athanasiadis, Georgios; Jørgensen, Frank G.; Cheng, Jade Y.; Kjærgaard, Peter C.; Schierup, Mikkel H.; Mailund, Thomas

    2016-01-01

    Scientific outreach delivers science to the people. But it can also deliver people to the science. In this work, we report our experience from a large-scale public engagement project promoting genomic literacy among Danish high school students with the additional benefit of collecting data for studying the genetic makeup of the Danish population. Not only did we confirm that students have a great interest in their genetic past, but we were also gratified to see that, with the right motivation, adolescents can provide high-quality data for genetic studies. PMID:27571202

  10. Spitting for Science: Danish High School Students Commit to a Large-Scale Self-Reported Genetic Study.

    PubMed

    Athanasiadis, Georgios; Jørgensen, Frank G; Cheng, Jade Y; Kjærgaard, Peter C; Schierup, Mikkel H; Mailund, Thomas

    2016-01-01

    Scientific outreach delivers science to the people. But it can also deliver people to the science. In this work, we report our experience from a large-scale public engagement project promoting genomic literacy among Danish high school students with the additional benefit of collecting data for studying the genetic makeup of the Danish population. Not only did we confirm that students have a great interest in their genetic past, but we were also gratified to see that, with the right motivation, adolescents can provide high-quality data for genetic studies. PMID:27571202

  11. A Snapshot of Functional Genetic Studies in Medicago truncatula.

    PubMed

    Kang, Yun; Li, Minguye; Sinharoy, Senjuti; Verdier, Jerome

    2016-01-01

    In the current context of food security, increase of plant protein production in a sustainable manner represents one of the major challenges of agronomic research, which could be partially resolved by increased cultivation of legume crops. Medicago truncatula is now a well-established model for legume genomic and genetic studies. With the establishment of genomics tools and mutant populations in M. truncatula, it has become an important resource to answer some of the basic biological questions related to plant development and stress tolerance. This review has an objective to overview a decade of genetic studies in this model plant from generation of mutant populations to nowadays. To date, the three biological fields, which have been extensively studied in M. truncatula, are the symbiotic nitrogen fixation, the seed development, and the abiotic stress tolerance, due to their significant agronomic impacts. In this review, we summarize functional genetic studies related to these three major biological fields. We integrated analyses of a nearly exhaustive list of genes into their biological contexts in order to provide an overview of the forefront research advances in this important legume model plant. PMID:27555857

  12. A Snapshot of Functional Genetic Studies in Medicago truncatula

    PubMed Central

    Kang, Yun; Li, Minguye; Sinharoy, Senjuti; Verdier, Jerome

    2016-01-01

    In the current context of food security, increase of plant protein production in a sustainable manner represents one of the major challenges of agronomic research, which could be partially resolved by increased cultivation of legume crops. Medicago truncatula is now a well-established model for legume genomic and genetic studies. With the establishment of genomics tools and mutant populations in M. truncatula, it has become an important resource to answer some of the basic biological questions related to plant development and stress tolerance. This review has an objective to overview a decade of genetic studies in this model plant from generation of mutant populations to nowadays. To date, the three biological fields, which have been extensively studied in M. truncatula, are the symbiotic nitrogen fixation, the seed development, and the abiotic stress tolerance, due to their significant agronomic impacts. In this review, we summarize functional genetic studies related to these three major biological fields. We integrated analyses of a nearly exhaustive list of genes into their biological contexts in order to provide an overview of the forefront research advances in this important legume model plant. PMID:27555857

  13. Physiological basis of tolerance to complete submergence in rice involves genetic factors in addition to the SUB1 gene.

    PubMed

    Singh, Sudhanshu; Mackill, David J; Ismail, Abdelbagi M

    2014-01-01

    Recurring floods in Asia cause poor crop establishment. Yields decline drastically when plants are completely submerged for a few days. Traditional rice cultivars predominate because they have acquired moderate tolerance to flooding but they carry the penalty of inherently lower grain yields. In contrast, modern high-yielding varieties are highly susceptible to flooding. Cultivars with tolerance to complete submergence were recently developed in the background of popular varieties by transferring the submergence tolerance gene SUBMERGENCE1 (SUB1) from the highly tolerant Indian landrace FR13A. The present study evaluated three pairs of Sub1 near-isogenic lines (NILs) together with FR13A and two of its submergence-tolerant derivatives under field conditions to assess the survival and growth processes occurring during submergence and recovery that are associated with SUB1. Under control conditions, the NILs showed similar growth and biomass accumulation, indicating that SUB1 had no apparent effects. Submergence substantially decreased biomass accumulation but with greater reduction in the genotypes lacking SUB1, particularly when submergence was prolonged for 17 days. When submerged, the lines lacking SUB1 showed greater elongation and lower or negative biomass accumulation. Sub1 lines maintained higher chlorophyll concentrations during submergence and lost less non-structural carbohydrates (NSC) after submergence. This indicates that the introgression of SUB1 resulted in better regulation of NSC during submergence and that high pre-submergence NSC is not essential for the submergence tolerance conferred by SUB1. During recovery, chlorophyll degradation was faster in genotypes lacking SUB1 and any surviving plants showed poorer and delayed emergence of tillers and leaves. Sub1 lines restored new leaf and tiller production faster. During submergence, FR13A showed not only slower leaf elongation but also accumulated extra biomass and was able to recover faster than Sub

  14. Physiological basis of tolerance to complete submergence in rice involves genetic factors in addition to the SUB1 gene

    PubMed Central

    Singh, Sudhanshu; Mackill, David J.; Ismail, Abdelbagi M.

    2014-01-01

    Recurring floods in Asia cause poor crop establishment. Yields decline drastically when plants are completely submerged for a few days. Traditional rice cultivars predominate because they have acquired moderate tolerance to flooding but they carry the penalty of inherently lower grain yields. In contrast, modern high-yielding varieties are highly susceptible to flooding. Cultivars with tolerance to complete submergence were recently developed in the background of popular varieties by transferring the submergence tolerance gene SUBMERGENCE1 (SUB1) from the highly tolerant Indian landrace FR13A. The present study evaluated three pairs of Sub1 near-isogenic lines (NILs) together with FR13A and two of its submergence-tolerant derivatives under field conditions to assess the survival and growth processes occurring during submergence and recovery that are associated with SUB1. Under control conditions, the NILs showed similar growth and biomass accumulation, indicating that SUB1 had no apparent effects. Submergence substantially decreased biomass accumulation but with greater reduction in the genotypes lacking SUB1, particularly when submergence was prolonged for 17 days. When submerged, the lines lacking SUB1 showed greater elongation and lower or negative biomass accumulation. Sub1 lines maintained higher chlorophyll concentrations during submergence and lost less non-structural carbohydrates (NSC) after submergence. This indicates that the introgression of SUB1 resulted in better regulation of NSC during submergence and that high pre-submergence NSC is not essential for the submergence tolerance conferred by SUB1. During recovery, chlorophyll degradation was faster in genotypes lacking SUB1 and any surviving plants showed poorer and delayed emergence of tillers and leaves. Sub1 lines restored new leaf and tiller production faster. During submergence, FR13A showed not only slower leaf elongation but also accumulated extra biomass and was able to recover faster than Sub

  15. Knowledge Gaining by Human Genetic Studies on Tuberculosis Susceptibility

    PubMed Central

    Qu, Hui-Qi; Fisher-Hoch, Susan P; McCormick, Joseph B

    2011-01-01

    Tuberculosis (TB) is a serious health issue in the developing world. Lack of knowledge on the etiological mechanisms of TB hinders the development of effective strategies for the treatment or prevention of TB disease. Human genetic study is an indispensable approach to understand the molecular basis of common diseases. Numerous efforts were made to screen the human genome for TB susceptibility by linkage mapping. A large number of candidate-based association studies of TB were performed to examine the association of predicted functional DNA variations in candidate genes. Recently, the first genome-wide association study (GWAS) on TB was reported. The GWAS is a proof-of-principle evidence which justifies the genetic approach to understand TB. Further hypothesis-free efforts on TB research may renovate the traditional idea of TB genetic susceptibility as none of the candidate genes with important roles in containing Mycobacterium tuberculosis (MTB) infection was identified of association with active TB, while the TB-associated loci in the GWAS harbors no gene with function in MTB infection. PMID:21179108

  16. [Genetic predisposition and Pediatric Acute Respiratory Distress Syndrome: New tools for genetic study].

    PubMed

    Erranz, M Benjamín; Wilhelm, B Jan; Riquelme, V Raquel; Cruces, R Pablo

    2015-01-01

    Acute respiratory distress syndrome (ARDS) is the most severe form of respiratory failure. Theoretically, any acute lung condition can lead to ARDS, but only a small percentage of individuals actually develop the disease. On this basis, genetic factors have been implicated in the risk of developing ARDS. Based on the pathophysiology of this disease, many candidate genes have been evaluated as potential modifiers in patient, as well as in animal models, of ARDS. Recent experimental data and clinical studies suggest that variations of genes involved in key processes of tissue, cellular and molecular lung damage may influence susceptibility and prognosis of ARDS. However, the pathogenesis of pediatric ARDS is complex, and therefore, it can be expected that many genes might contribute. Genetic variations such as single nucleotide polymorphisms and copy-number variations are likely associated with susceptibility to ARDS in children with primary lung injury. Genome-wide association (GWA) studies can objectively examine these variations, and help identify important new genes and pathogenetic pathways for future analysis. This approach might also have diagnostic and therapeutic implications, such as predicting patient risk or developing a personalized therapeutic approach to this serious syndrome. PMID:26235685

  17. Genome-wide Association Study of Dermatomyositis Reveals Genetic Overlap with other Autoimmune Disorders

    PubMed Central

    Miller, Frederick W.; Cooper, Robert G.; Vencovsky, Jiri; Rider, Lisa G.; Danko, Katalin; Wedderburn, Lucy R.; Lundberg, Ingrid E.; Pachman, Lauren M.; Reed, Ann M.; Ytterberg, Steven R.; Padyukov, Leonid; Selva-O’Callaghan, Albert; Radstake, Timothy; Isenberg, David A.; Chinoy, Hector; Ollier, William E. R.; O’Hanlon, Terrance P.; Peng, Bo; Lee, Annette; Lamb, Janine A.; Chen, Wei; Amos, Christopher I.; Gregersen, Peter K.

    2014-01-01

    Objective To identify new genetic associations with juvenile and adult dermatomyositis (DM). Methods We performed a genome-wide association study (GWAS) of adult and juvenile DM patients of European ancestry (n = 1178) and controls (n = 4724). To assess genetic overlap with other autoimmune disorders, we examined whether 141 single nucleotide polymorphisms (SNPs) outside the major histocompatibility complex (MHC) locus, and previously associated with autoimmune diseases, predispose to DM. Results Compared to controls, patients with DM had a strong signal in the MHC region consisting of GWAS-level significance (P < 5x10−8) at 80 genotyped SNPs. An analysis of 141 non-MHC SNPs previously associated with autoimmune diseases showed that three SNPs linked with three genes were associated with DM, with a false discovery rate (FDR) < 0.05. These genes were phospholipase C like 1 (PLCL1, rs6738825, FDR=0.00089), B lymphoid tyrosine kinase (BLK, rs2736340, FDR=0.00031), and chemokine (C-C motif) ligand 21 (CCL21, rs951005, FDR=0.0076). None of these genes was previously reported to be associated with DM. Conclusion Our findings confirm the MHC as the major genetic region associated with DM and indicate that DM shares non-MHC genetic features with other autoimmune diseases, suggesting the presence of additional novel risk loci. This first identification of autoimmune disease genetic predispositions shared with DM may lead to enhanced understanding of pathogenesis and novel diagnostic and therapeutic approaches. PMID:23983088

  18. Genome-Wide Association Study of Intelligence: Additive Effects of Novel Brain Expressed Genes

    ERIC Educational Resources Information Center

    Loo, Sandra K.; Shtir, Corina; Doyle, Alysa E.; Mick, Eric; McGough, James J.; McCracken, James; Biederman, Joseph; Smalley, Susan L.; Cantor, Rita M.; Faraone, Stephen V.; Nelson, Stanley F.

    2012-01-01

    Objective: The purpose of the present study was to identify common genetic variants that are associated with human intelligence or general cognitive ability. Method: We performed a genome-wide association analysis with a dense set of 1 million single-nucleotide polymorphisms (SNPs) and quantitative intelligence scores within an ancestrally…

  19. Genetic Diversity and Association Studies in US Hispanic/Latino Populations: Applications in the Hispanic Community Health Study/Study of Latinos

    PubMed Central

    Conomos, Matthew P.; Laurie, Cecelia A.; Stilp, Adrienne M.; Gogarten, Stephanie M.; McHugh, Caitlin P.; Nelson, Sarah C.; Sofer, Tamar; Fernández-Rhodes, Lindsay; Justice, Anne E.; Graff, Mariaelisa; Young, Kristin L.; Seyerle, Amanda A.; Avery, Christy L.; Taylor, Kent D.; Rotter, Jerome I.; Talavera, Gregory A.; Daviglus, Martha L.; Wassertheil-Smoller, Sylvia; Schneiderman, Neil; Heiss, Gerardo; Kaplan, Robert C.; Franceschini, Nora; Reiner, Alex P.; Shaffer, John R.; Barr, R. Graham; Kerr, Kathleen F.; Browning, Sharon R.; Browning, Brian L.; Weir, Bruce S.; Avilés-Santa, M. Larissa; Papanicolaou, George J.; Lumley, Thomas; Szpiro, Adam A.; North, Kari E.; Rice, Ken; Thornton, Timothy A.; Laurie, Cathy C.

    2016-01-01

    US Hispanic/Latino individuals are diverse in genetic ancestry, culture, and environmental exposures. Here, we characterized and controlled for this diversity in genome-wide association studies (GWASs) for the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). We simultaneously estimated population-structure principal components (PCs) robust to familial relatedness and pairwise kinship coefficients (KCs) robust to population structure, admixture, and Hardy-Weinberg departures. The PCs revealed substantial genetic differentiation within and among six self-identified background groups (Cuban, Dominican, Puerto Rican, Mexican, and Central and South American). To control for variation among groups, we developed a multi-dimensional clustering method to define a “genetic-analysis group” variable that retains many properties of self-identified background while achieving substantially greater genetic homogeneity within groups and including participants with non-specific self-identification. In GWASs of 22 biomedical traits, we used a linear mixed model (LMM) including pairwise empirical KCs to account for familial relatedness, PCs for ancestry, and genetic-analysis groups for additional group-associated effects. Including the genetic-analysis group as a covariate accounted for significant trait variation in 8 of 22 traits, even after we fit 20 PCs. Additionally, genetic-analysis groups had significant heterogeneity of residual variance for 20 of 22 traits, and modeling this heteroscedasticity within the LMM reduced genomic inflation for 19 traits. Furthermore, fitting an LMM that utilized a genetic-analysis group rather than a self-identified background group achieved higher power to detect previously reported associations. We expect that the methods applied here will be useful in other studies with multiple ethnic groups, admixture, and relatedness. PMID:26748518

  20. Genetic Diversity and Association Studies in US Hispanic/Latino Populations: Applications in the Hispanic Community Health Study/Study of Latinos.

    PubMed

    Conomos, Matthew P; Laurie, Cecelia A; Stilp, Adrienne M; Gogarten, Stephanie M; McHugh, Caitlin P; Nelson, Sarah C; Sofer, Tamar; Fernández-Rhodes, Lindsay; Justice, Anne E; Graff, Mariaelisa; Young, Kristin L; Seyerle, Amanda A; Avery, Christy L; Taylor, Kent D; Rotter, Jerome I; Talavera, Gregory A; Daviglus, Martha L; Wassertheil-Smoller, Sylvia; Schneiderman, Neil; Heiss, Gerardo; Kaplan, Robert C; Franceschini, Nora; Reiner, Alex P; Shaffer, John R; Barr, R Graham; Kerr, Kathleen F; Browning, Sharon R; Browning, Brian L; Weir, Bruce S; Avilés-Santa, M Larissa; Papanicolaou, George J; Lumley, Thomas; Szpiro, Adam A; North, Kari E; Rice, Ken; Thornton, Timothy A; Laurie, Cathy C

    2016-01-01

    US Hispanic/Latino individuals are diverse in genetic ancestry, culture, and environmental exposures. Here, we characterized and controlled for this diversity in genome-wide association studies (GWASs) for the Hispanic Community Health Study/Study of Latinos (HCHS/SOL). We simultaneously estimated population-structure principal components (PCs) robust to familial relatedness and pairwise kinship coefficients (KCs) robust to population structure, admixture, and Hardy-Weinberg departures. The PCs revealed substantial genetic differentiation within and among six self-identified background groups (Cuban, Dominican, Puerto Rican, Mexican, and Central and South American). To control for variation among groups, we developed a multi-dimensional clustering method to define a "genetic-analysis group" variable that retains many properties of self-identified background while achieving substantially greater genetic homogeneity within groups and including participants with non-specific self-identification. In GWASs of 22 biomedical traits, we used a linear mixed model (LMM) including pairwise empirical KCs to account for familial relatedness, PCs for ancestry, and genetic-analysis groups for additional group-associated effects. Including the genetic-analysis group as a covariate accounted for significant trait variation in 8 of 22 traits, even after we fit 20 PCs. Additionally, genetic-analysis groups had significant heterogeneity of residual variance for 20 of 22 traits, and modeling this heteroscedasticity within the LMM reduced genomic inflation for 19 traits. Furthermore, fitting an LMM that utilized a genetic-analysis group rather than a self-identified background group achieved higher power to detect previously reported associations. We expect that the methods applied here will be useful in other studies with multiple ethnic groups, admixture, and relatedness. PMID:26748518

  1. Using family members to augment genetic case-control studies of a life-threatening disease.

    PubMed

    Chen, Lu; Weinberg, Clarice R; Chen, Jinbo

    2016-07-20

    Survival bias is difficult to detect and adjust for in case-control genetic association studies but can invalidate findings when only surviving cases are studied and survival is associated with the genetic variants under study. Here, we propose a design where one genotypes genetically informative family members (such as offspring, parents, and spouses) of deceased cases and incorporates that surrogate genetic information into a retrospective maximum likelihood analysis. We show that inclusion of genotype data from first-degree relatives permits unbiased estimation of genotype association parameters. We derive closed-form maximum likelihood estimates for association parameters under the widely used log-additive and dominant association models. Our proposed design not only permits a valid analysis but also enhances statistical power by augmenting the sample with indirectly studied individuals. Gene variants associated with poor prognosis can also be identified under this design. We provide simulation results to assess performance of the methods. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26866629

  2. Genetically engineered mouse models to study prostate cancer.

    PubMed

    Brzezinska, Elspeth A; Nixon, Colin; Patel, Rachana; Leung, Hing Y

    2015-01-01

    Genetically engineered mouse models have become fundamental tools in the basic and translational research of prostate cancer. There is a plethora of models available to dissect the genetic alterations and aberrant signaling events associated with human prostate cancer and, furthermore, to investigate new and "personalized" therapies to treat the disease. In this chapter, we discuss some of the models recently and currently used to study prostate cancer in vivo, and some considerations when selecting an appropriate model to investigate particular aspects of the disease. We describe the methods required to isolate prostate tumors and conduct basic characterization of the tumor to determine tumor load and histopathology. We also discuss important aspects to be considered when processing samples for further analysis. PMID:25636465

  3. Study of genetic direct search algorithms for function optimization

    NASA Technical Reports Server (NTRS)

    Zeigler, B. P.

    1974-01-01

    The results are presented of a study to determine the performance of genetic direct search algorithms in solving function optimization problems arising in the optimal and adaptive control areas. The findings indicate that: (1) genetic algorithms can outperform standard algorithms in multimodal and/or noisy optimization situations, but suffer from lack of gradient exploitation facilities when gradient information can be utilized to guide the search. (2) For large populations, or low dimensional function spaces, mutation is a sufficient operator. However for small populations or high dimensional functions, crossover applied in about equal frequency with mutation is an optimum combination. (3) Complexity, in terms of storage space and running time, is significantly increased when population size is increased or the inversion operator, or the second level adaptation routine is added to the basic structure.

  4. Study of methanogens by genetic techniques. A subcontract progress report

    SciTech Connect

    Baresi, L.; Bertani, G.

    1984-06-01

    Genetic studies of methanogenic bacteria could lead to better exploitation of these organisms in the production of methane from biomass. The objective of this study is to develop a workable genetic system for these bacteria. We have tried to apply standard genetic techniques to these slow growing, strictly anaerobic bacteria. We have been able to isolate several types of mutants both spontaneous and induced. For Methanococcus voltae we have (a) established survival curves to ultraviolet light and gamma ray irradiation, (b) isolated by direct selection mutants resistant to bromo-ethane-sulfonate and to 5-methyl-tryptophan, and a double mutant exhibiting both resistances, (c) isolated after mutagenesis two nutritional mutants (one requiring histidine and the other requiring adenine and possibly another factor). For Methanobacterium thermoautotrophicum we have (a) established an ultraviolet light survival curve, (b) isolated by direct selection mutants resistant to bromo-ethane-sulfonate and to gentamicin. We have developed a routine technique for the purpose of isolating phages capable of infecting methanogenic bacteria. 10 figures, 1 table.

  5. Genetic influences on osteoarthritis in women: a twin study.

    PubMed Central

    Spector, T. D.; Cicuttini, F.; Baker, J.; Loughlin, J.; Hart, D.

    1996-01-01

    OBJECTIVES--To assess the relative contribution of genetic and environmental factors to common forms of osteoarthritis of the hands and knees. DESIGN--Classic twin study with unselected twins who were screened radiologically for osteoarthritis. SUBJECTS--130 identical and 120 non-identical female twins aged 48-70 recruited from a London based twin register and through a national media campaign. MAIN OUTCOME MEASURES--Similarity in identical compared with non-identical twin pairs for radiographic changes at the interphalangeal and first carpometacarpal joints of the hands and the tibiofemoral joint and patellofemoral joint of the knee expressed as intraclass correlations. RESULTS--The intraclass correlations of radiographic osteophytes and narrowing at most sites and the presence of Heberden's nodes and knee pain were higher in the identical pairs. The intraclass correlation of the total radiographic osteoarthritis score in identical pairs (rMZ) was 0.64 (SE 0.05) compared with 0.38 (0.08) in non-identical pairs. The proportion of genetic variance of total osteoarthritis score (osteophytes and narrowing) with modelling techniques was estimated at 0.54 (95% confidence interval 0.43 to 0.65) and ranged from 0.39 to 0.65 for different sites and features (p < 0.001) after adjustment for age and weight. CONCLUSIONS--These results demonstrate for the first time a clear genetic effect for radiographic osteoarthritis of the hand and knee in women, with a genetic influence ranging from 39-65%, independent of known environmental or demographic confounders. The results of this study should lead to further work on isolating the gene or genes involved in the pathogenesis of the common disabling disease. PMID:8616305

  6. A Novel Lung Disease Phenotype Adjusted for Mortality Attrition for Cystic Fibrosis Genetic Modifier Studies

    PubMed Central

    Taylor, Chelsea; Commander, Clayton W.; Collaco, Joseph M.; Strug, Lisa J.; Li, Weili; Wright, Fred A.; Webel, Aaron D.; Pace, Rhonda G.; Stonebraker, Jaclyn R.; Naughton, Kathleen; Dorfman, Ruslan; Sandford, Andrew; Blackman, Scott M.; Berthiaume, Yves; Paré, Peter; Drumm, Mitchell L.; Zielenski, Julian; Durie, Peter; Cutting, Garry R.; Knowles, Michael R.; Corey, Mary

    2011-01-01

    SUMMARY Genetic studies of lung disease in Cystic Fibrosis are hampered by the lack of a severity measure that accounts for chronic disease progression and mortality attrition. Further, combining analyses across studies requires common phenotypes that are robust to study design and patient ascertainment. Using data from the North American Cystic Fibrosis Modifier Consortium (Canadian Consortium for CF Genetic Studies, Johns Hopkins University CF Twin and Sibling Study, and University of North Carolina/Case Western Reserve University Gene Modifier Study), the authors calculated age-specific CF percentile values of FEV1 which were adjusted for CF age-specific mortality data. The phenotype was computed for 2061 patients representing the Canadian CF population, 1137 extreme phenotype patients in the UNC/Case Western study, and 1323 patients from multiple CF sib families in the CF Twin and Sibling Study. Despite differences in ascertainment and median age, our phenotype score was distributed in all three samples in a manner consistent with ascertainment differences, reflecting the lung disease severity of each individual in the underlying population. The new phenotype score was highly correlated with the previously recommended complex phenotype, but the new phenotype is more robust for shorter follow-up and for extreme ages. A disease progression and mortality adjusted phenotype reduces the need for stratification or additional covariates, increasing statistical power and avoiding possible distortions. This approach will facilitate large scale genetic and environmental epidemiological studies which will provide targeted therapeutic pathways for the clinical benefit of patients with CF. PMID:21462361

  7. Functional Analysis of the Human Genome:. Study of Genetic Disease

    NASA Astrophysics Data System (ADS)

    Tsui, Lap-Chee

    2003-04-01

    I will divide my remarks into 3 parts. First, I will give a brief summary of the Human Genome Project. Second, I will describe our work on human chromosome 7 to illustrate how we could contribute to the Project and disease research. Third, I would like to bring across the argument that study of genetic disease is an integral component of the Human Genome Project. In particular, I will use cystic fibrosis as an example to elaborate why I consider disease study is a part of functional genomics.

  8. Pathogenesis of immunoglobulin A nephropathy: recent insight from genetic studies.

    PubMed

    Kiryluk, Krzysztof; Novak, Jan; Gharavi, Ali G

    2013-01-01

    Recent genome-wide association studies (GWAS) have identified multiple susceptibility loci for immunoglobulin A nephropathy (IgAN), the most common form of glomerulonephritis, implicating independent defects in adaptive immunity (three loci on chromosome 6p21 in the MHC region), innate immunity (8p23 DEFA locus, 17p23 TNFSF13 locus, 22q12 HORMAD2 locus), and the alternative complement pathway (1q32 CFH/CFHR locus). In geospatial analysis of 85 populations, a genetic risk score based on the replicated GWAS loci is highest in Asians, intermediate in Europeans, and lowest in Africans, capturing the known difference in prevalence among world populations. The genetic risk score also uncovered a previously unsuspected increased prevalence of IgAN-attributable kidney failure in Northern Europe. The IgAN risk alleles have opposing effects on many immune-mediated diseases, suggesting that selection has contributed to variation in risk allele frequencies among different populations. Incorporating genetic, immunologic, and biochemical data, we present a multistep pathogenesis model that provides testable hypotheses for dissecting the mechanisms of disease. PMID:23072577

  9. Meta-analyses of genetic studies on major depressive disorder.

    PubMed

    López-León, S; Janssens, A C J W; González-Zuloeta Ladd, A M; Del-Favero, J; Claes, S J; Oostra, B A; van Duijn, C M

    2008-08-01

    The genetic basis of major depressive disorder (MDD) has been investigated extensively, but the identification of MDD genes has been hampered by conflicting results from underpowered studies. We review all MDD case-control genetic association studies published before June 2007 and perform meta-analyses for polymorphisms that had been investigated in at least three studies. The study selection and data extraction were performed in duplicate by two independent investigators. The 183 papers that met our criteria studied 393 polymorphisms in 102 genes. Twenty-two polymorphisms (6%) were investigated in at least three studies. Seven polymorphisms had been evaluated in previous meta-analyses, 5 of these had new data available. Hence, we performed meta-analyses for 20 polymorphisms in 18 genes. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated. Statistically significant associations were found for the APOE varepsilon2 (OR, 0.51), GNB3 825T (OR, 1.38), MTHFR 677T (OR, 1.20), SLC6A4 44 bp Ins/Del S (OR, 1.11) alleles and the SLC6A3 40 bpVNTR 9/10 genotype (OR, 2.06). To date, there is statistically significant evidence for six MDD susceptibility genes (APOE, DRD4, GNB3, MTHFR, SLC6A3 and SLC6A4). PMID:17938638

  10. The Genetic and Environmental Contributions to Internet Use and Associations With Psychopathology: A Twin Study.

    PubMed

    Long, Elizabeth C; Verhulst, Brad; Neale, Michael C; Lind, Penelope A; Hickie, Ian B; Martin, Nicholas G; Gillespie, Nathan A

    2016-02-01

    Excessive internet use has been linked to psychopathology. Therefore, understanding the genetic and environmental risks underpinning internet use and their relation to psychopathology is important. This study aims to explore the genetic and environmental etiology of internet use measures and their associations with internalizing disorders and substance use disorders. The sample included 2,059 monozygotic (MZ) and dizygotic (DZ) young adult twins from the Brisbane Longitudinal Twin Study (BLTS). Younger participants reported more frequent internet use, while women were more likely to use the internet for interpersonal communication. Familial aggregation in 'frequency of internet use' was entirely explained by additive genetic factors accounting for 41% of the variance. Familial aggregation in 'frequency of use after 11 pm', 'using the internet to contact peers', and 'using the internet primarily to access social networking sites' was attributable to varying combinations of additive genetic and shared environmental factors. In terms of psychopathology, there were no significant associations between internet use measures and major depression (MD), but there were positive significant associations between 'frequency of internet use' and 'frequency of use after 11 pm' with social phobia (SP). 'Using the internet to contact peers' was positively associated with alcohol abuse, whereas 'using the internet to contact peers' and 'using the internet primarily to access social networking sites' were negatively associated with cannabis use disorders and nicotine symptoms. Individual differences in internet use can be attributable to varying degrees of genetic and environmental risks. Despite some significant associations of small effect, variation in internet use appears mostly unrelated to psychopathology. PMID:26693596

  11. The Genetic and Environmental Contributions to Internet Use and Associations With Psychopathology: A Twin Study

    PubMed Central

    Long, Elizabeth C.; Verhulst, Brad; Neale, Michael C.; Lind, Penelope A.; Hickie, Ian B.; Martin, Nicholas G.; Gillespie, Nathan A.

    2016-01-01

    Excessive internet use has been linked to psychopathology. Therefore, understanding the genetic and environmental risks underpinning internet use and their relation to psychopathology is important. This study aims to explore the genetic and environmental etiology of internet use measures and their associations with internalizing disorders and substance use disorders. The sample included 2,059 monozygotic (MZ) and dizygotic (DZ) young adult twins from the Brisbane Longitudinal Twin Study (BLTS). Younger participants reported more frequent internet use, while women were more likely to use the internet for interpersonal communication. Familial aggregation in ‘frequency of internet use’ was entirely explained by additive genetic factors accounting for 41% of the variance. Familial aggregation in ‘frequency of use after 11 pm’, ‘using the internet to contact peers’, and ‘using the internet primarily to access social networking sites’ was attributable to varying combinations of additive genetic and shared environmental factors. In terms of psychopathology, there were no significant associations between internet use measures and major depression (MD), but there were positive significant associations between ‘frequency of internet use’ and ‘frequency of use after 11 pm’ with social phobia (SP). ‘Using the internet to contact peers’ was positively associated with alcohol abuse, whereas ‘using the internet to contact peers’ and ‘using the internet primarily to access social networking sites’ were negatively associated with cannabis use disorders and nicotine symptoms. Individual differences in internet use can be attributable to varying degrees of genetic and environmental risks. Despite some significant associations of small effect, variation in internet use appears mostly unrelated to psychopathology. PMID:26693596

  12. Scientific rationality, uncertainty and the governance of human genetics: an interview study with researchers at deCODE genetics.

    PubMed

    Hjörleifsson, Stefán; Schei, Edvin

    2006-07-01

    Technology development in human genetics is fraught with uncertainty, controversy and unresolved moral issues, and industry scientists are sometimes accused of neglecting the implications of their work. The present study was carried out to elicit industry scientists' reflections on the relationship between commercial, scientific and ethical dimensions of present day genetics and the resources needed for robust governance of new technologies. Interviewing scientists of the company deCODE genetics in Iceland, we found that in spite of optimism, the informants revealed ambiguity and uncertainty concerning the use of human genetic technologies for the prevention of common diseases. They concurred that uncritical marketing of scientific success might cause exaggerated public expectations of health benefits from genetics, with the risk of backfiring and causing resistance to genetics in the population. On the other hand, the scientists did not address dilemmas arising from the commercial nature of their own employer. Although the scientists tended to describe public fear as irrational, they identified issues where scepticism might be well founded and explored examples where they, despite expert knowledge, held ambiguous or tentative personal views on the use of predictive genetic technologies. The rationality of science was not seen as sufficient to ensure beneficial governance of new technologies. The reflexivity and suspension of judgement demonstrated in the interviews exemplify productive features of moral deliberation in complex situations. Scientists should take part in dialogues concerning the governance of genetic technologies, acknowledge any vested interests, and use their expertise to highlight, not conceal the technical and moral complexity involved. PMID:16622446

  13. Genetic Geostatistical Framework for Spatial Analysis of Fine-Scale Genetic Heterogeneity in Modern Populations: Results from the KORA Study.

    PubMed

    Diaz-Lacava, A N; Walier, M; Holler, D; Steffens, M; Gieger, C; Furlanello, C; Lamina, C; Wichmann, H E; Becker, T

    2015-01-01

    Aiming to investigate fine-scale patterns of genetic heterogeneity in modern humans from a geographic perspective, a genetic geostatistical approach framed within a geographic information system is presented. A sample collected for prospective studies in a small area of southern Germany was analyzed. None indication of genetic heterogeneity was detected in previous analysis. Socio-demographic and genotypic data of German citizens were analyzed (212 SNPs; n = 728). Genetic heterogeneity was evaluated with observed heterozygosity (H O ). Best-fitting spatial autoregressive models were identified, using socio-demographic variables as covariates. Spatial analysis included surface interpolation and geostatistics of observed and predicted patterns. Prediction accuracy was quantified. Spatial autocorrelation was detected for both socio-demographic and genetic variables. Augsburg City and eastern suburban areas showed higher H O values. The selected model gave best predictions in suburban areas. Fine-scale patterns of genetic heterogeneity were observed. In accordance to literature, more urbanized areas showed higher levels of admixture. This approach showed efficacy for detecting and analyzing subtle patterns of genetic heterogeneity within small areas. It is scalable in number of loci, even up to whole-genome analysis. It may be suggested that this approach may be applicable to investigate the underlying genetic history that is, at least partially, embedded in geographic data. PMID:26258132

  14. Genetic Geostatistical Framework for Spatial Analysis of Fine-Scale Genetic Heterogeneity in Modern Populations: Results from the KORA Study

    PubMed Central

    Diaz-Lacava, A. N.; Walier, M.; Holler, D.; Steffens, M.; Gieger, C.; Furlanello, C.; Lamina, C.; Wichmann, H. E.; Becker, T.

    2015-01-01

    Aiming to investigate fine-scale patterns of genetic heterogeneity in modern humans from a geographic perspective, a genetic geostatistical approach framed within a geographic information system is presented. A sample collected for prospective studies in a small area of southern Germany was analyzed. None indication of genetic heterogeneity was detected in previous analysis. Socio-demographic and genotypic data of German citizens were analyzed (212 SNPs; n = 728). Genetic heterogeneity was evaluated with observed heterozygosity (HO). Best-fitting spatial autoregressive models were identified, using socio-demographic variables as covariates. Spatial analysis included surface interpolation and geostatistics of observed and predicted patterns. Prediction accuracy was quantified. Spatial autocorrelation was detected for both socio-demographic and genetic variables. Augsburg City and eastern suburban areas showed higher HO values. The selected model gave best predictions in suburban areas. Fine-scale patterns of genetic heterogeneity were observed. In accordance to literature, more urbanized areas showed higher levels of admixture. This approach showed efficacy for detecting and analyzing subtle patterns of genetic heterogeneity within small areas. It is scalable in number of loci, even up to whole-genome analysis. It may be suggested that this approach may be applicable to investigate the underlying genetic history that is, at least partially, embedded in geographic data. PMID:26258132

  15. Genetic study of oxygen resistance and melanization in Cryptococcus neoformans.

    PubMed Central

    Emery, H S; Shelburne, C P; Bowman, J P; Fallon, P G; Schulz, C A; Jacobson, E S

    1994-01-01

    Genetic analysis of oxygen-sensitive mutants of Cryptococcus neoformans revealed two loci (oxy1 and oxy2) linking hyperoxia sensitivity to production of melanin, a known virulence factor. Hyperoxia-sensitive strain 562 (oxy1 oxy2) is albino and avirulent. oxy2-defective strains lacking the oxy1 defect are melanin deficient but show normal hyperoxia resistance. Mutants defective at three additional mapped melanin loci fail to show hyperoxia sensitivity in the oxy1 background. Revertants of strain 562, which regain the ability to synthesize melanin by mutation at suppressor sites unlinked to oxy2, retain the oxygen sensitivity conferred by their oxy1 and oxy2 defects. These data identify the melanin gene oxy2 as unique in its association of hyperoxia resistance and melanization. Images PMID:7960156

  16. Genetic parameters and genome-wide association study of hyperpigmentation of the visceral peritoneum in chickens

    PubMed Central

    2013-01-01

    Background Hyperpigmentation of the visceral peritoneum (HVP) has recently garnered much attention in the poultry industry because of the possible risk to the health of affected animals and the damage it causes to the appearance of commercial chicken carcasses. However, the heritable characters of HVP remain unclear. The objective of this study was to investigate the genetic parameters of HVP by genome-wide association study (GWAS) in chickens. Results HVP was found to be influenced by genetic factors, with a heritability score of 0.33. HVP had positive genetic correlations with growth and carcass traits, such as leg muscle weight (rg = 0.34), but had negative genetic correlations with immune traits, such as the antibody response to Newcastle disease virus (rg = −0.42). The GWAS for HVP using 39,833 single nucleotide polymorphisms indicated the genetic factors associated with HVP displayed an additive effect rather than a dominance effect. In addition, we determined that three genomic regions, involving the 50.5–54.0 Mb region of chicken (Gallus gallus) chromosome 1 (GGA1), the 58.5–60.5 Mb region of GGA1, and the 10.5–12.0 Mb region of GGA20, were strongly associated (P < 6.28 × 10-7) with HVP in chickens. Variants in these regions explained >50% of additive genetic variance for HVP. This study also confirmed that expression of BMP7, which codes for a bone morphogenetic protein and is located in one of the candidate regions, was significantly higher in the visceral peritoneum of Huiyang Beard chickens with HVP than in that of chickens without pigmentation (P < 0.05). Conclusions HVP is a quantitative trait with moderate heritability. Genomic variants resulting in HVP were identified on GGA1 and GGA20, and expression of the BMP7 gene appears to be upregulated in HVP-affected chickens. Findings from this study should be used as a basis for further functional validation of candidate genes involved in HVP. PMID:23679099

  17. The Tourette International Collaborative Genetics (TIC Genetics) study, finding the genes causing Tourette syndrome: objectives and methods.

    PubMed

    Dietrich, Andrea; Fernandez, Thomas V; King, Robert A; State, Matthew W; Tischfield, Jay A; Hoekstra, Pieter J; Heiman, Gary A

    2015-02-01

    Tourette syndrome (TS) is a neuropsychiatric disorder characterized by recurrent motor and vocal tics, often accompanied by obsessive-compulsive disorder and/or attention-deficit/hyperactivity disorder. While the evidence for a genetic contribution is strong, its exact nature has yet to be clarified fully. There is now mounting evidence that the genetic risks for TS include both common and rare variants and may involve complex multigenic inheritance or, in rare cases, a single major gene. Based on recent progress in many other common disorders with apparently similar genetic architectures, it is clear that large patient cohorts and open-access repositories will be essential to further advance the field. To that end, the large multicenter Tourette International Collaborative Genetics (TIC Genetics) study was established. The goal of the TIC Genetics study is to undertake a comprehensive gene discovery effort, focusing both on familial genetic variants with large effects within multiply affected pedigrees and on de novo mutations ascertained through the analysis of apparently simplex parent-child trios with non-familial tics. The clinical data and biomaterials (DNA, transformed cell lines, RNA) are part of a sharing repository located within the National Institute for Mental Health Center for Collaborative Genomics Research on Mental Disorders, USA, and will be made available to the broad scientific community. This resource will ultimately facilitate better understanding of the pathophysiology of TS and related disorders and the development of novel therapies. Here, we describe the objectives and methods of the TIC Genetics study as a reference for future studies from our group and to facilitate collaboration between genetics consortia in the field of TS. PMID:24771252

  18. A preliminary investigation of genetic counselors’ information needs when receiving a variant of uncertain significance result: a mixed methods study

    PubMed Central

    Scherr, Courtney L.; Lindor, Noralane M.; Malo, Teri L.; Couch, Fergus J.; Vadaparampil, Susan T.

    2015-01-01

    Purpose To explore genetic counselors’ information preferences on reports of variant of uncertain significance (VUS) results from cancer genetic testing. Methods This mixed methods report (quantitative and qualitative approaches) utilized a survey of genetic counselors containing closed- and open-ended questions to explore genetic counselors’ information needs and perceptions of the industry’s current information sharing practices. Descriptive statistics were calculated for responses to the closed-ended questions and thematic analysis guided the interpretation of the open-ended questions. Results Of the 267 participants (28.6% response rate), the majority indicated a perceived lack of information on VUS laboratory reports, were concerned about the perceived practice of withholding information, and stated the information they wanted to see. Although most did not indicate how additional information would be used, some reported they would provide information directly to patients, and others reported the information would be used to contextualize the VUS result when counseling patients. Conclusion This analysis identified information genetic counselors believe is needed on VUS reports indicating what they believe are best practices in lieu of guidelines for laboratories currently providing genetic testing services, and implies needed guidelines for reporting VUS. Future studies should explore how genetic counselors use additional information contained on VUS reports. PMID:25569439

  19. Genetic studies of bipolar affective disorder in large families.

    PubMed

    Blackwood, D H; Visscher, P M; Muir, W J

    2001-06-01

    Background Genetic factors are known to be important in the aetiology of bipolar disorder. Aims To review linkage studies in extended families multiply affected with bipolar disorder. Method Selective review of linkage studies of bipolar disorder emphasising the gains and drawbacks of studying large multiply-affected families and comparing the statistical methods used for data analysis. Results Linkage of bipolar disorder to several chromosome regions including 4p, 4q, 10p, 12q, 16p, 18q, 21q and Xq has first been reported in extended families. In other families chromosomal rearrangements associated with affective illnesses provide signposts to the location of disease-related genes. Statistical analyses using variance component methods can be applied to extended families, require no prior knowledge of the disease inheritance, and can test multilocus models. Conclusion Studying single large pedigrees combined with variance component analysis is an efficient and effective strategy likely to lead to further insights into the genetic basis of bipolar disorders. PMID:11388952

  20. Population genetic studies in the Balkans. I. Serum proteins.

    PubMed

    Scheil, H G; Scheffrahn, W; Schmidt, H D; Huckenbeck, W; Efremovska, L; Xirotiris, N

    2001-09-01

    Within a study of the genetics of Southeastern European populations seven serum protein polymorphisms (AMY2, BF, C3, CP, GC, HPA, TF) were examined in three samples of Aromuns (Albania: the village of Andon Poci, province Gjirocaster, Republic of Macedonia: Stip region, Romania: the village Kogalniceanu, province Dobruja) and four reference samples (Albanians: Tirana, Romanians: Constanta and Ploiesti as well as Greeks (Northeastern Greece)). The Aromun samples from Albania and Romania form one separate cluster and the reference samples together with the Aromuns from Macedonia (Stip region) form a second one. PMID:11591047

  1. The adequacy of informed consent forms in genetic research in Oman: a pilot study.

    PubMed

    Al-Riyami, Asya; Jaju, Deepali; Jaju, Sanjay; Silverman, Henry J

    2011-08-01

    Genetic research presents ethical challenges to the achievement of valid informed consent, especially in developing countries with areas of low literacy. During the last several years, a number of genetic research proposals involving Omani nationals were submitted to the Department of Research and Studies, Ministry of Health, Oman. The objective of this paper is to report on the results of an internal quality assurance initiative to determine the extent of the information being provided in genetic research informed consent forms. In order to achieve this, we developed checklists to assess the inclusion of basic elements of informed consent as well as elements related to the collection and future storage of biological samples. Three of the authors independently evaluated and reached consensus on seven informed consent forms that were available for review. Of the seven consent forms, four had less than half of the basic elements of informed consent. None contained any information regarding whether genetic information relevant to health would be disclosed, whether participants may share in commercial products, the extent of confidentiality protections, and the inclusion of additional consent forms for future storage and use of tissue samples. Information regarding genetic risks and withdrawal of samples were rarely mentioned (1/7), whereas limits on future use of samples were mentioned in 3 of 7 consent forms. Ultimately, consent forms are not likely to address key issues regarding genetic research that have been recommended by research ethics guidelines. We recommend enhanced educational efforts to increase awareness, on the part of researchers, of information that should be included in consent forms. PMID:21266001

  2. Study of wood plastic composite in the presence of nitrogen containing additives

    NASA Astrophysics Data System (ADS)

    Ali, K. M. Idriss; Khan, Mubarak A.; Husain, M. M.

    1994-10-01

    Effect of nitrogen-containing additives in the study of wood plastic composites of MMA with simul and mango wood of Bangladesh has been investigated. Nine different additives were used and the additives containing carboamide group induce the highest tensile strength to the composite.

  3. Studies of genetic transformation of higher plants using irradiated pollen

    SciTech Connect

    Chyi, Y.S.

    1984-01-01

    Pandey has reported extensively on an unusual genetic phenomenon he called egg transformation. When compatible pollen was treated wth genetically lethal dosage of ..gamma..-radiation (100,000 rad), and used as mentor pollen to overcome selfincompatibility of several Nicotiana species, some genetic characters were found to be transferred from the radiation killed pollen to nonhybrid progeny. Observed transformants were fertile, cytogenetically normal, and had maternal phenotypes except for those specific traits transferred from the donors. Heavily irradiated pollen was believed to discharge its radiation-fragmented DNA (chromatin) into the embryo sac and bring about the transformation of the egg. The frequency of gene transfer was reported to be over 50%, and happened for all three characters Pandey studied - self incompatible specificities, flower color, and pollen color. Plant species studied were tomato, pea, apple, rapeseed, and Nicotiana species, including various stocks from Dr. Pandey. Treatments included pollinations with soley irradiated donor pollen, with a mixture of irradiated donor and normal self pollen, with a mixture of normal donor and self pollen, and double pollinations with irradiated donor pollen and normal self pollen, using different time intervals to separate the two pollinations. A total of 6210 pollinations were made, and 17,522 seedlings representing 87,750 potential transformational events were screened. In no case was an unambiguous transformant recovered. This research was unable to confirm or expand upon the findings of Dr. Pandey, or elucidate the mechanisms underlying such phenomena. Alternative explanations for Pandey's data were postulated. This approach to gene transfer by using irradiated pollen appears to be of little practical use to plant breeders.

  4. Genetic associations with neuroendocrine tumor risk: results from a genome-wide association study.

    PubMed

    Du, Yeting; Ter-Minassian, Monica; Brais, Lauren; Brooks, Nichole; Waldron, Amanda; Chan, Jennifer A; Lin, Xihong; Kraft, Peter; Christiani, David C; Kulke, Matthew H

    2016-08-01

    The etiology of neuroendocrine tumors remains poorly defined. Although neuroendocrine tumors are in some cases associated with inherited genetic syndromes, such syndromes are rare. The majority of neuroendocrine tumors are thought to be sporadic. We performed a genome-wide association study (GWAS) to identify potential genetic risk factors for sporadic neuroendocrine tumors. Using germline DNA from blood specimens, we genotyped 909,622 SNPs using the Affymetrix 6.0 GeneChip, in a cohort comprising 832 neuroendocrine tumor cases from Dana-Farber Cancer Institute and Massachusetts General Hospital and 4542 controls from the Harvard School of Public Health. An additional 241 controls from Dana-Farber Cancer Institute were used for quality control. We assessed risk associations in the overall cohort, and in neuroendocrine tumor subgroups. We identified no potential risk associations in the cohort overall. In the small intestine neuroendocrine tumor subgroup, comprising 293 cases, we identified risk associations with three SNPs on chromosome 12, all in strong LD. The three SNPs are located upstream of ELK3, a transcription factor implicated in angiogenesis. We did not identify clear risk associations in the bronchial or pancreatic neuroendocrine subgroups. This large-scale study provides initial evidence that presumed sporadic small intestine neuroendocrine tumors may have a genetic etiology. Our results provide a basis for further exploring the role of genes implicated in this analysis, and for replication studies to confirm the observed associations. Additional studies to evaluate potential genetic risk factors for sporadic pancreatic and bronchial neuroendocrine tumors are warranted. PMID:27492634

  5. Genetic Variants Associated with Increased Risk of Malignant Pleural Mesothelioma: A Genome-Wide Association Study

    PubMed Central

    Matullo, Giuseppe; Guarrera, Simonetta; Betti, Marta; Fiorito, Giovanni; Ferrante, Daniela; Voglino, Floriana; Cadby, Gemma; Di Gaetano, Cornelia; Rosa, Fabio; Russo, Alessia; Hirvonen, Ari; Casalone, Elisabetta; Tunesi, Sara; Padoan, Marina; Giordano, Mara; Aspesi, Anna; Casadio, Caterina; Ardissone, Francesco; Ruffini, Enrico; Betta, Pier Giacomo; Libener, Roberta; Guaschino, Roberto; Piccolini, Ezio; Neri, Monica; Musk, Arthur W. B.; de Klerk, Nicholas H.; Hui, Jennie; Beilby, John; James, Alan L.; Creaney, Jenette; Robinson, Bruce W.; Mukherjee, Sutapa; Palmer, Lyle J.; Mirabelli, Dario; Ugolini, Donatella; Bonassi, Stefano; Magnani, Corrado; Dianzani, Irma

    2013-01-01

    Asbestos exposure is the main risk factor for malignant pleural mesothelioma (MPM), a rare aggressive tumor. Nevertheless, only 5–17% of those exposed to asbestos develop MPM, suggesting the involvement of other environmental and genetic risk factors. To identify the genetic risk factors that may contribute to the development of MPM, we conducted a genome-wide association study (GWAS; 370,000 genotyped SNPs, 5 million imputed SNPs) in Italy, among 407 MPM cases and 389 controls with a complete history of asbestos exposure. A replication study was also undertaken and included 428 MPM cases and 1269 controls from Australia. Although no single marker reached the genome-wide significance threshold, several associations were supported by haplotype-, chromosomal region-, gene- and gene-ontology process-based analyses. Most of these SNPs were located in regions reported to harbor aberrant alterations in mesothelioma (SLC7A14, THRB, CEBP350, ADAMTS2, ETV1, PVT1 and MMP14 genes), causing at most a 2–3-fold increase in MPM risk. The Australian replication study showed significant associations in five of these chromosomal regions (3q26.2, 4q32.1, 7p22.2, 14q11.2, 15q14). Multivariate analysis suggested an independent contribution of 10 genetic variants, with an Area Under the ROC Curve (AUC) of 0.76 when only exposure and covariates were included in the model, and of 0.86 when the genetic component was also included, with a substantial increase of asbestos exposure risk estimation (odds ratio, OR: 45.28, 95% confidence interval, CI: 21.52–95.28). These results showed that genetic risk factors may play an additional role in the development of MPM, and that these should be taken into account to better estimate individual MPM risk in individuals who have been exposed to asbestos. PMID:23626673

  6. Genetic variants associated with increased risk of malignant pleural mesothelioma: a genome-wide association study.

    PubMed

    Matullo, Giuseppe; Guarrera, Simonetta; Betti, Marta; Fiorito, Giovanni; Ferrante, Daniela; Voglino, Floriana; Cadby, Gemma; Di Gaetano, Cornelia; Rosa, Fabio; Russo, Alessia; Hirvonen, Ari; Casalone, Elisabetta; Tunesi, Sara; Padoan, Marina; Giordano, Mara; Aspesi, Anna; Casadio, Caterina; Ardissone, Francesco; Ruffini, Enrico; Betta, Pier Giacomo; Libener, Roberta; Guaschino, Roberto; Piccolini, Ezio; Neri, Monica; Musk, Arthur W B; de Klerk, Nicholas H; Hui, Jennie; Beilby, John; James, Alan L; Creaney, Jenette; Robinson, Bruce W; Mukherjee, Sutapa; Palmer, Lyle J; Mirabelli, Dario; Ugolini, Donatella; Bonassi, Stefano; Magnani, Corrado; Dianzani, Irma

    2013-01-01

    Asbestos exposure is the main risk factor for malignant pleural mesothelioma (MPM), a rare aggressive tumor. Nevertheless, only 5-17% of those exposed to asbestos develop MPM, suggesting the involvement of other environmental and genetic risk factors. To identify the genetic risk factors that may contribute to the development of MPM, we conducted a genome-wide association study (GWAS; 370,000 genotyped SNPs, 5 million imputed SNPs) in Italy, among 407 MPM cases and 389 controls with a complete history of asbestos exposure. A replication study was also undertaken and included 428 MPM cases and 1269 controls from Australia. Although no single marker reached the genome-wide significance threshold, several associations were supported by haplotype-, chromosomal region-, gene- and gene-ontology process-based analyses. Most of these SNPs were located in regions reported to harbor aberrant alterations in mesothelioma (SLC7A14, THRB, CEBP350, ADAMTS2, ETV1, PVT1 and MMP14 genes), causing at most a 2-3-fold increase in MPM risk. The Australian replication study showed significant associations in five of these chromosomal regions (3q26.2, 4q32.1, 7p22.2, 14q11.2, 15q14). Multivariate analysis suggested an independent contribution of 10 genetic variants, with an Area Under the ROC Curve (AUC) of 0.76 when only exposure and covariates were included in the model, and of 0.86 when the genetic component was also included, with a substantial increase of asbestos exposure risk estimation (odds ratio, OR: 45.28, 95% confidence interval, CI: 21.52-95.28). These results showed that genetic risk factors may play an additional role in the development of MPM, and that these should be taken into account to better estimate individual MPM risk in individuals who have been exposed to asbestos. PMID:23626673

  7. Genetic-Quantitative Study of the First-Service Pregnancy Probability of Murrah Heifers.

    PubMed

    Fernandes, P B; Marques, K O; de Araujo Neto, F R; de Oliveira, D P; Hurtado-Lugo, N A; Aspilcueta-Borquis, R R; Tonhati, H

    2016-06-01

    Because of the importance of reproduction in stock breeding systems, it is necessary to find selection criteria that increase reproductive efficiency. The aim of this study was to estimate genetic parameters for the probability of conception on first service (PROB) in Murrah heifers, and its association with other traits of economic interest [age at first calving (AFC), service period, calving interval and milk yield at 270 days], with the purpose of evaluating their use as selection criteria. Reproductive information and first lactation records of 1200 Murrah heifers were used to perform two-trait analyses between PROB and the other characteristics. Bayesian inference was used to estimate the variance components, considering PROB as threshold and the other as linear factors. The results demonstrate that this trait has heritability of 0.15, indicating the possibility of a genetic gain by using it for selection. With respect to the genetic correlation estimates, the only high-magnitude association was with AFC (-0.899), which is the current criterion indicating sexual precocity of females. In the light of the parameters estimated, the first-service pregnancy rate is an alternative for indication of sexual precocity, although presenting a smaller genetic gain than the current standard AFC. Nevertheless, additional research should be conducted regarding this trait to assess the economic importance of its use in dairy buffalo production systems. PMID:27117537

  8. [Genome-wide association study on complex diseases: study design and genetic markers].

    PubMed

    Yan, Wei-Li

    2008-04-01

    Genome-wide association study used to be a dream of geneticists years ago, but now it came true. Since the first paper reported the finding of genetic variation contributing to human age-related macular degeneration by genome-wide association study in 2005, a numbers of whole genome studies have been published. The present paper reviewed some common comments in whole genome association study on complex diseases, including achievements of genome-wide association studies on complex traits or diseases, principles of study design, selection of genetic marker in genome, and comparisons of different commercial products for whole genome association study. Finally a newly defined genetic variation, copy number variation, was briefly introduced. This paper also summarized the shortcomings of current genome-wide association studies and perspectives of its future. PMID:18424408

  9. The Case of the "Tainted" Taco Shells: A Case Study on Genetically Modified Foods

    ERIC Educational Resources Information Center

    Taylor, Ann T. S.

    2004-01-01

    This case study introduces students to the use of genetically modified foods. Students learn how genetically modified plants are made, and then they read primary literature papers to evaluate the environmental, economic, and health issues. (Contains 2 figures.)

  10. Biochemical and Molecular Genetic Studies on Biosilica Morphogenesis in Diatoms

    NASA Astrophysics Data System (ADS)

    Kroger, N.; Poulsen, N.

    2006-12-01

    Diatoms are a large group of unicellular microalgae encased by silica cell walls that exhibit species-specific micro-and nanopatterns. Previously, we have characterized from diatoms unique phosphoproteins (termed silaffins) and unusually long polyamine chains (termed LCPA), which have both been implicated in biosilica formation. While the chemical structures of LCPA are largely conserved among different diatom species, the silaffins exhibit extensive structural variations. In vitro studies on the silica formation activities of silaffins and LCPA from the diatom Thalassiosira pseudonana indicate that silica morphogenesis is primarily determined by silaffins rather than LCPA. Recently, the complete genome sequence of T. pseudonana has become available, which for the first time opens the door to employ functional genomic approaches for studying the mechanism of silica biomineralization. To this end we have established the first genetic transformation system for T. pseudonana, which will be instrumental for analyzing the functions of silaffins in vivo, and for identifying new components of the diatom silica forming machinery. Here we describe the current knowledge on the structures and properties of silaffins and LCPA, the methods for genetic manipulation of T. pseudonana, and the first experimental steps towards functional genomics in diatoms.

  11. Osteoporosis and genetic influence: a three-generation study.

    PubMed Central

    Kahn, S. A.; Pace, J. E.; Cox, M. L.; Gau, D. W.; Cox, S. A.; Hodkinson, H. M.

    1994-01-01

    We have studied 27 triads of mother, daughter and grandmother for possible genetic influence on distal and proximal forearm bone density, measured by single photon absorptiometry. We found a significant correlation of bone density at the proximal forearm between the mothers and grandmothers (r = 0.499, P < 0.01). There was also a weak correlation between proximal forearm bone densities of mothers and daughters (r = 0.327, P < 0.1). Significant correlations were found between the three generations for grip strength, pedometry, height and triceps skinfold thickness. There was also significant correlation between mother and grandmother for alcohol intake. There was no correlation for contraceptive pill use, smoking, dietary calcium intake, body weight or body mass index. The study concludes that, although there are similarities in bone mineral content between the three generations, genetic factors cannot be conclusively proven to be the major determinant of bone density. Lifestyle and environmental factors may have a bearing on achieving the peak bone mass and subsequent development of osteoporosis. PMID:7824412

  12. Children of the atomic bomb survivors: A genetic study

    SciTech Connect

    Neel, J.V.; Schull, W.J.

    1991-01-01

    This volume represents the results of over 40 years of study of the latent health effects on the survivors of the atomic bomb blasts. Planning for this research began in 1946 and data collection has been ongoing since 1948. The work represents the efforts of both US and Japanese agencies and presents 13 papers which the editors believe represent the best scientific information related to the genetic effects of radiation exposure. In general, the results presented here indicate that radiation exposure effects on reproductive cells are less than previously thought. The paper contained here examine that question in light of effects on pregnancy outcome, sex ratio, congenital defects, and early mortality of children. The papers also present helpful comparison of these results with the results seen in experimental radiation studies with animals. For anyone interested in the risks associated with radiation studies, this book represents a vital collection of information.

  13. Discerning the Ancestry of European Americans in Genetic Association Studies

    PubMed Central

    Price, Alkes L; Butler, Johannah; Patterson, Nick; Capelli, Cristian; Pascali, Vincenzo L; Scarnicci, Francesca; Ruiz-Linares, Andres; Groop, Leif; Saetta, Angelica A; Korkolopoulou, Penelope; Seligsohn, Uri; Waliszewska, Alicja; Schirmer, Christine; Ardlie, Kristin; Ramos, Alexis; Nemesh, James; Arbeitman, Lori; Goldstein, David B

    2008-01-01

    European Americans are often treated as a homogeneous group, but in fact form a structured population due to historical immigration of diverse source populations. Discerning the ancestry of European Americans genotyped in association studies is important in order to prevent false-positive or false-negative associations due to population stratification and to identify genetic variants whose contribution to disease risk differs across European ancestries. Here, we investigate empirical patterns of population structure in European Americans, analyzing 4,198 samples from four genome-wide association studies to show that components roughly corresponding to northwest European, southeast European, and Ashkenazi Jewish ancestry are the main sources of European American population structure. Building on this insight, we constructed a panel of 300 validated markers that are highly informative for distinguishing these ancestries. We demonstrate that this panel of markers can be used to correct for stratification in association studies that do not generate dense genotype data. PMID:18208327

  14. Methods to Study Metastasis in Genetically Modified Mice.

    PubMed

    Kabeer, Farhia; Beverly, Levi J; Darrasse-Jèze, Guillaume; Podsypanina, Katrina

    2016-02-01

    Metastasis is often modeled by xenotransplantation of cell lines in immunodeficient mice. A wealth of information about tumor cell behavior in the new environment is obtained from these efforts. Yet by design, this approach is "tumor-centric," as it focuses on cell-autonomous determinants of human tumor dissemination in mouse tissues, in effect using the animal body as a sophisticated "Petri dish" providing nutrients and support for tumor growth. Transgenic or gene knockout mouse models of cancer allow the study of tumor spread as a systemic disease and offer a complimentary approach for studying the natural history of cancer. This introduction is aimed at describing the overall methodological approach to studying metastasis in genetically modified mice, with a particular focus on using animals with regulated expression of potent human oncogenes in the breast. PMID:26832689

  15. Do Other People's Plights Matter? A Genetically Informed Twin Study of the Role of Social Context in the Link between Peer Victimization and Children's Aggression and Depression Symptoms

    ERIC Educational Resources Information Center

    Brendgen, Mara; Vitaro, Frank; Barker, Edward D.; Girard, Alain; Dionne, Ginette; Tremblay, Richard E.; Boivin, Michel

    2013-01-01

    Using a genetically informed design, this study examined the additive and interactive effects of genetic risk, personal peer victimization experiences, and peer victimization experienced by others on children's aggression and depression symptoms. Of major interest was whether these effects varied depending on whether or not the victimized others…

  16. The power of genetic monitoring for studying demography, ecology and genetics of a reintroduced brown bear population.

    PubMed

    De Barba, M; Waits, L P; Garton, E O; Genovesi, P; Randi, E; Mustoni, A; Groff, C

    2010-09-01

    Genetic monitoring has rarely been used for wildlife translocations despite the potential benefits this approach offers, compared to traditional field-based methods. We applied genetic monitoring to the reintroduced brown bear population in northern Italy. From 2002 to 2008, 2781 hair and faecal samples collected noninvasively plus 12 samples obtained from captured or dead bears were used to follow the demographic and geographical expansion and changes in genetic composition. Individual genotypes were used to reconstruct the wild pedigree and revealed that the population increased rapidly, from nine founders to >27 individuals in 2008 (lambda=1.17-1.19). Spatial mapping of bear samples indicated that most bears were distributed in the region surrounding the translocation site; however, individual bears were found up to 163 km away. Genetic diversity in the population was high, with expected heterozygosity of 0.74-0.79 and allelic richness of 4.55-5.41. However, multi-year genetic monitoring data showed that mortality rates were elevated, immigration did not occur, one dominant male sired all cubs born from 2002 to 2005, genetic diversity declined, relatedness increased, inbreeding occurred, and the effective population size was extremely small (Ne=3.03, ecological method). The comprehensive information collected through genetic monitoring is critical for implementing future conservation plans for the brown bear population in the Italian Alps. This study provides a model for other reintroduction programmes by demonstrating how genetic monitoring can be implemented to uncover aspects of the demography, ecology and genetics of small and reintroduced populations that will advance our understanding of the processes influencing their viability, evolution, and successful restoration. PMID:20735733

  17. Exogenous Visual Orienting Is Associated with Specific Neurotransmitter Genetic Markers: A Population-Based Genetic Association Study

    PubMed Central

    Lundwall, Rebecca A.; Guo, Dong-Chuan; Dannemiller, James L.

    2012-01-01

    Background Currently, there is a sense that the spatial orienting of attention is related to genotypic variations in cholinergic genes but not to variations in dopaminergic genes. However, reexamination of associations with both cholinergic and dopaminergic genes is warranted because previous studies used endogenous rather than exogenous cues and costs and benefits were not analyzed separately. Examining costs (increases in response time following an invalid pre-cue) and benefits (decreases in response time following a valid pre-cue) separately could be important if dopaminergic genes (implicated in disorders such as attention deficit disorder) independently influence the different processes of orienting (e.g., disengage, move, engage). Methodology/Principal Findings We tested normal subjects (N = 161) between 18 and 61 years. Participants completed a computer task in which pre-cues preceded the presence of a target. Subjects responded (with a key press) to the location of the target (right versus left of fixation). The cues could be valid (i.e., appear where the target would appear) or invalid (appear contralateral to where the target would appear). DNA sequencing assays were performed on buccal cells to genotype known genetic markers and these were examined for association with task scores. Here we show significant associations between visual orienting and genetic markers (on COMT, DAT1, and APOE; R2s from 4% to 9%). Conclusions/Significance One measure in particular – the response time cost of a single dim, invalid cue – was associated with dopaminergic markers on COMT and DAT1. Additionally, variations of APOE genotypes based on the ε2/ε3/ε4 alleles were also associated with response time differences produced by simultaneous cues with unequal luminances. We conclude that individual differences in visual orienting are related to several dopaminergic markers as well as to a cholinergic marker. These results challenge the view that orienting is not

  18. Systematic meta-analyses and field synopsis of genetic association studies of violence and aggression

    PubMed Central

    Vassos, E; Collier, D A; Fazel, S

    2014-01-01

    A large number of candidate gene studies for aggression and violence have been conducted. Successful identification of associations between genetic markers and aggression would contribute to understanding the neurobiology of antisocial behavior and potentially provide useful tools for risk prediction and therapeutic targets for high-risk groups of patients and offenders. We systematically reviewed the literature and assessed the evidence on genetic association studies of aggression and related outcomes in order to provide a field synopsis. We searched PubMed and Huge Navigator databases and sought additional data through reviewing reference lists and correspondence with investigators. Genetic association studies were included if outcome data on aggression or violent behavior either as a binary outcome or as a quantitative trait were provided. From 1331 potentially relevant investigations, 185 studies constituting 277 independent associations on 31 genes fulfilled the predetermined selection criteria. Data from variants investigated in three or more samples were combined in meta-analyses and potential sources of heterogeneity were investigated using subgroup analyses. In the primary analyses, which used relaxed inclusion criteria, we found no association between any polymorphism analyzed and aggression at the 5% level of significance. Subgroup analyses, including by severity of outcome, age group, characteristics of the sample and ethnicity, did not demonstrate any consistent findings. Current evidence does not support the use of such genes to predict dangerousness or as markers for therapeutic interventions. PMID:23546171

  19. Deaf Adults’ Reasons for Genetic Testing Depend on Cultural Affiliation: Results From a Prospective, Longitudinal Genetic Counseling and Testing Study

    PubMed Central

    Boudreault, Patrick; Baldwin, Erin E.; Fox, Michelle; Dutton, Loriel; Tullis, LeeElle; Linden, Joyce; Kobayashi, Yoko; Zhou, Jin; Sinsheimer, Janet S.; Sininger, Yvonne; Grody, Wayne W.; Palmer, Christina G. S.

    2010-01-01

    This article examines the relationship between cultural affiliation and deaf adults’ motivations for genetic testing for deafness in the first prospective, longitudinal study to examine the impact of genetic counseling and genetic testing on deaf adults and the deaf community. Participants (n = 256), classified as affiliating with hearing, Deaf, or both communities, rated interest in testing for 21 reasons covering 5 life domains. Findings suggest strong interest in testing to learn why they are deaf, but little interest in using it for decisions about a partner or having children. Culturally mediated variation was also demonstrated. Deaf and both communities groups viewed testing as useful for more life domains than the hearing community group. Deaf and both communities had similar motivations related to further exploration, understanding, or strengthening of deafness. Motivations related to “hearing” were also relevant for both communities. We conclude that cultural affiliation is an important factor for constructing motivations for genetic testing. PMID:20488870

  20. Modeling AEC-New approaches to study rare genetic disorders.

    PubMed

    Koch, Peter J; Dinella, Jason; Fete, Mary; Siegfried, Elaine C; Koster, Maranke I

    2014-10-01

    Ankyloblepharon-ectodermal defects-cleft lip/palate (AEC) syndrome is a rare monogenetic disorder that is characterized by severe abnormalities in ectoderm-derived tissues, such as skin and its appendages. A major cause of morbidity among affected infants is severe and chronic skin erosions. Currently, supportive care is the only available treatment option for AEC patients. Mutations in TP63, a gene that encodes key regulators of epidermal development, are the genetic cause of AEC. However, it is currently not clear how mutations in TP63 lead to the various defects seen in the patients' skin. In this review, we will discuss current knowledge of the AEC disease mechanism obtained by studying patient tissue and genetically engineered mouse models designed to mimic aspects of the disorder. We will then focus on new approaches to model AEC, including the use of patient cells and stem cell technology to replicate the disease in a human tissue culture model. The latter approach will advance our understanding of the disease and will allow for the development of new in vitro systems to identify drugs for the treatment of skin erosions in AEC patients. Further, the use of stem cell technology, in particular induced pluripotent stem cells (iPSC), will enable researchers to develop new therapeutic approaches to treat the disease using the patient's own cells (autologous keratinocyte transplantation) after correction of the disease-causing mutations. PMID:24665072

  1. Simultaneous Bayesian analysis of contingency tables in genetic association studies.

    PubMed

    Dickhaus, Thorsten

    2015-08-01

    Genetic association studies lead to simultaneous categorical data analysis. The sample for every genetic locus consists of a contingency table containing the numbers of observed genotype-phenotype combinations. Under case-control design, the row counts of every table are identical and fixed, while column counts are random. The aim of the statistical analysis is to test independence of the phenotype and the genotype at every locus. We present an objective Bayesian methodology for these association tests, which relies on the conjugacy of Dirichlet and multinomial distributions. Being based on the likelihood principle, the Bayesian tests avoid looping over all tables with given marginals. Making use of data generated by The Wellcome Trust Case Control Consortium (WTCCC), we illustrate that the ordering of the Bayes factors shows a good agreement with that of frequentist p-values. Furthermore, we deal with specifying prior probabilities for the validity of the null hypotheses, by taking linkage disequilibrium structure into account and exploiting the concept of effective numbers of tests. Application of a Bayesian decision theoretic multiple test procedure to the WTCCC data illustrates the proposed methodology. Finally, we discuss two methods for reconciling frequentist and Bayesian approaches to the multiple association test problem. PMID:26215535

  2. The Relevance of HLA Sequencing in Population Genetics Studies

    PubMed Central

    Sanchez-Mazas, Alicia

    2014-01-01

    Next generation sequencing (NGS) is currently being adapted by different biotechnological platforms to the standard typing method for HLA polymorphism, the huge diversity of which makes this initiative particularly challenging. Boosting the molecular characterization of the HLA genes through efficient, rapid, and low-cost technologies is expected to amplify the success of tissue transplantation by enabling us to find donor-recipient matching for rare phenotypes. But the application of NGS technologies to the molecular mapping of the MHC region also anticipates essential changes in population genetic studies. Huge amounts of HLA sequence data will be available in the next years for different populations, with the potential to change our understanding of HLA variation in humans. In this review, we first explain how HLA sequencing allows a better assessment of the HLA diversity in human populations, taking also into account the methodological difficulties it introduces at the statistical level; secondly, we show how analyzing HLA sequence variation may improve our comprehension of population genetic relationships by facilitating the identification of demographic events that marked human evolution; finally, we discuss the interest of both HLA and genome-wide sequencing and genotyping in detecting functionally significant SNPs in the MHC region, the latter having also contributed to the makeup of the HLA molecular diversity observed today. PMID:25126587

  3. Transgenic animal models of neurodegeneration based on human genetic studies

    PubMed Central

    Richie, Christopher T.; Hoffer, Barry J.; Airavaara, Mikko

    2011-01-01

    The identification of genes linked to neurodegenerative diseases such as Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), Huntington's disease (HD) and Parkinson's disease (PD) has led to the development of animal models for studying mechanism and evaluating potential therapies. None of the transgenic models developed based on disease-associated genes have been able to fully recapitulate the behavioral and pathological features of the corresponding disease. However, there has been enormous progress made in identifying potential therapeutic targets and understanding some of the common mechanisms of neurodegeneration. In this review, we will discuss transgenic animal models for AD, ALS, HD and PD that are based on human genetic studies. All of the diseases discussed have active or complete clinical trials for experimental treatments that benefited from transgenic models of the disease. PMID:20931247

  4. Genetic studies in relation to kuru: an overview.

    PubMed

    Goldfarb, L G; Cervenakova, L; Gajdusek, D C

    2004-06-01

    Kuru is a subacute neurodegenerative disease presenting with limb ataxia, dysarthria, and a shivering tremor. The disease progress to complete motor and mental incapacity and death within 6 to 24 months. Neuropathologically, a typical pattern of neuronal loss, astrocytic and microglial proliferation, characteristic "kuru-type" amyloid plaques, and PrP deposits in the cerebral cortex and cerebellum are observed. Kuru is the prototype of a group of human transmissible spongiform encephalopathies (TSEs), or "prion" diseases, that include hereditary, sporadic and infectious forms. The latest member of this group, the variant Creutzfeldt-Jakob disease (vCJD), linked to transmission of bovine spongiform encephalopathy (BSE) to humans, shows features similar to kuru. Kuru has emerged at the beginning of the 1900s in a small indigenous population of New-Guinean Eastern Highlands, reached epidemic proportions in the mid-1950s and disappeared progressively in the latter half of the century to complete absence at the end of the 1990s. Early studies made infection, the first etiologic assumption, seem unlikely and led to a hypothesis that kuru might be a genetically determined or genetically mediated illness. After transmissibility of kuru had been discovered and all major epidemiologic phenomena adequately explained by the spread of an infectious agent with long incubation period through the practice of cannibalism, the pattern of occurrence still continued to suggest a role for genetic predisposition. Recent studies indicate that individuals homozygous for Methionine at a polymorphic position 129 of the prion protein were preferentially affected during the kuru epidemic. The carriers of the alternative 129Met/Val and 129Val/Val genotypes had a longer incubation period and thus developed disease at a later age and at a later stage of the epidemic. Observations made during the kuru epidemic are helpful in the understanding of the current vCJD outbreak, and vice versa clinical

  5. Evolutionary triangulation: informing genetic association studies with evolutionary evidence.

    PubMed

    Huang, Minjun; Graham, Britney E; Zhang, Ge; Harder, Reed; Kodaman, Nuri; Moore, Jason H; Muglia, Louis; Williams, Scott M

    2016-01-01

    Genetic studies of human diseases have identified many variants associated with pathogenesis and severity. However, most studies have used only statistical association to assess putative relationships to disease, and ignored other factors for evaluation. For example, evolution is a factor that has shaped disease risk, changing allele frequencies as human populations migrated into and inhabited new environments. Since many common variants differ among populations in frequency, as does disease prevalence, we hypothesized that patterns of disease and population structure, taken together, will inform association studies. Thus, the population distributions of allelic risk variants should reflect the distributions of their associated diseases. Evolutionary Triangulation (ET) exploits this evolutionary differentiation by comparing population structure among three populations with variable patterns of disease prevalence. By selecting populations based on patterns where two have similar rates of disease that differ substantially from a third, we performed a proof of principle analysis for this method. We examined three disease phenotypes, lactase persistence, melanoma, and Type 2 diabetes mellitus. We show that for lactase persistence, a phenotype with a simple genetic architecture, ET identifies the key gene, lactase. For melanoma, ET identifies several genes associated with this disease and/or phenotypes related to it, such as skin color genes. ET was less obviously successful for Type 2 diabetes mellitus, perhaps because of the small effect sizes in known risk loci and recent environmental changes that have altered disease risk. Alternatively, ET may have revealed new genes involved in conferring disease risk for diabetes that did not meet nominal GWAS significance thresholds. We also compared ET to another method used to filter for phenotype associated genes, population branch statistic (PBS), and show that ET performs better in identifying genes known to associate with

  6. Genetic Influence on the Variance in Coincidence Timing and Its Covariance with IQ: A Twin Study.

    ERIC Educational Resources Information Center

    Wright, Margaret J.; Smith, Glen A.; Geffen, Gina M.; Geffen, Laurie B.; Martin, Nicholas G.

    2000-01-01

    Studied whether genetic variability explained some of the variance in coincidence timing and whether common genetic factors accounted for the association with intellectual functioning using 55 pairs of 16-year-old twins. Results suggest that the genetic influence operating on coincidence timing skills was of similar magnitude to that of response…

  7. Genome-wide association study of swine farrowing traits. Part I: Genetic and genomic parameter estimates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The primary objective of this study was to determine genetic and genomic parameters among swine farrowing traits. Genetic parameters were obtained by using MTDFREML and genomic parameters were obtained using GenSel. Genetic and residual variances obtained from MTDFREML were used as priors for the ...

  8. Mapping the Regional Influence of Genetics on Brain Structure Variability - A Tensor-Based Morphometry Study

    PubMed Central

    Brun, Caroline; Leporé, Natasha; Pennec, Xavier; Lee, Agatha D.; Barysheva, Marina; Madsen, Sarah K.; Avedissian, Christina; Chou, Yi-Yu; de Zubicaray, Greig I.; McMahon, Katie; Wright, Margaret; Toga, Arthur W.; Thompson, Paul M.

    2010-01-01

    Genetic and environmental factors influence brain structure and function profoundly The search for heritable anatomical features and their influencing genes would be accelerated with detailed 3D maps showing the degree to which brain morphometry is genetically determined. As part of an MRI study that will scan 1150 twins, we applied Tensor-Based Morphometry to compute morphometric differences in 23 pairs of identical twins and 23 pairs of same-sex fraternal twins (mean age: 23.8 ± 1.8 SD years). All 92 twins’ 3D brain MRI scans were nonlinearly registered to a common space using a Riemannian fluid-based warping approach to compute volumetric differences across subjects. A multi-template method was used to improve volume quantification. Vector fields driving each subject’s anatomy onto the common template were analyzed to create maps of local volumetric excesses and deficits relative to the standard template. Using a new structural equation modeling method, we computed the voxelwise proportion of variance in volumes attributable to additive (A) or dominant (D) genetic factors versus shared environmental (C) or unique environmental factors (E). The method was also applied to various anatomical regions of interest (ROIs). As hypothesized, the overall volumes of the brain, basal ganglia, thalamus, and each lobe were under strong genetic control; local white matter volumes were mostly controlled by common environment. After adjusting for individual differences in overall brain scale, genetic influences were still relatively high in the corpus callosum and in early-maturing brain regions such as the occipital lobes, while environmental influences were greater in frontal brain regions which have a more protracted maturational time-course. PMID:19446645

  9. Blinders, phenotype, and fashionable genetic analysis: a critical examination of the current state of epilepsy genetic studies.

    PubMed

    Greenberg, David A; Subaran, Ryan

    2011-01-01

    Although it is accepted that idiopathic generalized epilepsy (IGE) is strongly, if not exclusively, influenced by genetic factors, there is little consensus on what those genetic influences may be, except for one point of agreement: epilepsy is a "channelopathy." This point of agreement has continued despite the failure of studies investigating channel genes to demonstrate the primacy of their influence on IGE expression. The belief is sufficiently entrenched that the more important issues involving phenotype definition, data collection, methods of analysis, and the interpretation of results have become subordinate to it. The goal of this article is to spark discussion of where the study of epilepsy genetics has been and where it is going, suggesting we may never get there if we continue on the current road. We use the long history of psychiatric genetic studies as a mirror and starting point to illustrate that only when we expand our outlook on how to study the genetics of the epilepsies, consider other mechanisms that could lead to epilepsy susceptibility, and, especially, focus on the critical problem of phenotype definition, will the major influences on common epilepsy begin to be understood. PMID:21219301

  10. Genetic Studies on Diabetic Microvascular Complications: Focusing on Genome-Wide Association Studies

    PubMed Central

    Kwak, Soo Heon

    2015-01-01

    Diabetes is a common metabolic disorder with a worldwide prevalence of 8.3% and is the leading cause of visual loss, end-stage renal disease and amputation. Recently, genome-wide association studies (GWASs) have identified genetic risk factors for diabetic microvascular complications of retinopathy, nephropathy, and neuropathy. We summarized the recent findings of GWASs on diabetic microvascular complications and highlighted the challenges and our opinion on future directives. Five GWASs were conducted on diabetic retinopathy, nine on nephropathy, and one on neuropathic pain. The majority of recent GWASs were underpowered and heterogeneous in terms of study design, inclusion criteria and phenotype definition. Therefore, few reached the genome-wide significance threshold and the findings were inconsistent across the studies. Recent GWASs provided novel information on genetic risk factors and the possible pathophysiology of diabetic microvascular complications. However, further collaborative efforts to standardize phenotype definition and increase sample size are necessary for successful genetic studies on diabetic microvascular complications. PMID:26194074

  11. Population genetic studies in the genomic sequencing era

    PubMed Central

    CHEN, Hua

    2015-01-01

    Recent advances in high-throughput sequencing technologies have revolutionized the field of population genetics. Data now routinely contain genomic level polymorphism information, and the low cost of DNA sequencing enables researchers to investigate tens of thousands of subjects at a time. This provides an unprecedented opportunity to address fundamental evolutionary questions, while posing challenges on traditional population genetic theories and methods. This review provides an overview of the recent methodological developments in the field of population genetics, specifically methods used to infer ancient population history and investigate natural selection using large-sample, large-scale genetic data. Several open questions are also discussed at the end of the review. PMID:26228473

  12. Additive-dominance genetic model analyses for late-maturity alpha-amylase activity in a bread wheat factorial crossing population.

    PubMed

    Rasul, Golam; Glover, Karl D; Krishnan, Padmanaban G; Wu, Jixiang; Berzonsky, William A; Ibrahim, Amir M H

    2015-12-01

    Elevated level of late maturity α-amylase activity (LMAA) can result in low falling number scores, reduced grain quality, and downgrade of wheat (Triticum aestivum L.) class. A mating population was developed by crossing parents with different levels of LMAA. The F2 and F3 hybrids and their parents were evaluated for LMAA, and data were analyzed using the R software package 'qgtools' integrated with an additive-dominance genetic model and a mixed linear model approach. Simulated results showed high testing powers for additive and additive × environment variances, and comparatively low powers for dominance and dominance × environment variances. All variance components and their proportions to the phenotypic variance for the parents and hybrids were significant except for the dominance × environment variance. The estimated narrow-sense heritability and broad-sense heritability for LMAA were 14 and 54%, respectively. High significant negative additive effects for parents suggest that spring wheat cultivars 'Lancer' and 'Chester' can serve as good general combiners, and that 'Kinsman' and 'Seri-82' had negative specific combining ability in some hybrids despite of their own significant positive additive effects, suggesting they can be used as parents to reduce LMAA levels. Seri-82 showed very good general combining ability effect when used as a male parent, indicating the importance of reciprocal effects. High significant negative dominance effects and high-parent heterosis for hybrids demonstrated that the specific hybrid combinations; Chester × Kinsman, 'Lerma52' × Lancer, Lerma52 × 'LoSprout' and 'Janz' × Seri-82 could be generated to produce cultivars with significantly reduced LMAA level. PMID:26403988

  13. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 11 2013-01-01 2013-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  14. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Engineering and cost studies-addition of generation... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253 Engineering... engineering and cost studies as specified by RUS. The studies shall cover a period from the beginning of...

  15. Association of genetic variants with hypertension in a longitudinal population-based genetic epidemiological study

    PubMed Central

    YAMADA, YOSHIJI; MATSUI, KOTA; TAKEUCHI, ICHIRO; OGURI, MITSUTOSHI; FUJIMAKI, TETSUO

    2015-01-01

    We previously identified 9 genes and chromosomal region 3q28 as susceptibility loci for Japanese patients with myocardial infarction, ischemic stroke, or chronic kidney disease by genome-wide or candidate gene association studies. In the present study, we investigated the possible association of 13 single nucleotide polymorphisms (SNPs) at these 10 loci with the prevalence of hypertension or their association with blood pressure (BP) in community-dwelling individuals in Japan. The study subjects comprised 6,027 individuals (2,250 subjects with essential hypertension, 3,777 controls) who were recruited into the Inabe Health and Longevity Study, a longitudinal genetic epidemiological study on atherosclerotic, cardiovascular and metabolic diseases. The subjects were recruited from individuals who visited the Health Care Center of Inabe General Hospital for an annual health checkup, and they are followed up each year (mean follow-up period, 5 years). Longitudinal analysis with a generalized estimating equation and with adjustment for age, gender, body mass index and smoking status revealed that rs2116519 of family with sequence similarity 78, member B (FAM78B; P=0.0266), rs6929846 of butyrophilin, subfamily 2, member A1 (BTN2A1; P= 0.0013), rs146021107 of pancreatic and duodenal homeobox 1 (PDX1; P=0.0031) and rs1671021 of lethal giant larvae homolog 2 (Drosophila) (LLGL2; P=0.0372) were significantly (P<0.05) associated with the prevalence of hypertension. Longitudinal analysis with a generalized linear mixed-effect model and with adjustment for age, gender, body mass index and smoking status among individuals not taking anti-hypertensive medication revealed that rs6929846 of BTN2A1 was significantly associated with systolic (P=0.0017), diastolic (P=0.0008) and mean (P=0.0005) BP, and that rs2116519 of FAM78B, rs146021107 of PDX1 and rs1671021 of LLGL2 were significantly associated with diastolic (P=0.0495), systolic (P=0.0132), and both diastolic (P=0.0468) and mean

  16. Genetic Studies of Stuttering in a Founder Population

    PubMed Central

    Wittke-Thompson, Jacqueline K.; Ambrose, Nicoline; Yairi, Ehud; Roe, Cheryl; Cook, Edwin H.; Ober, Carole; Cox, Nancy J.

    2007-01-01

    Genome-wide linkage and association analyses were conducted to identify genetic determinants of stuttering in a founder population in which 48 individuals affected with stuttering are connected in a single 232-person genealogy. A novel approach was devised to account for all necessary relationships to enable multipoint linkage analysis. Regions with nominal evidence for linkage were found on chromosomes 3 (P=0.013, 208.8 centiMorgans (cM)), 13 (P=0.012, 52.6 cM), and 15 (P=0.02, 100 cM). Regions with nominal evidence for association with stuttering that overlapped with a linkage signal are located on chromosomes 3 (P=0.0047, 195 cM), 9 (P=0.0067, 46.5 cM), and 13 (P=0.0055, 52.6 cM). We also conducted the first meta-analysis for stuttering using results from linkage studies in the Hutterites and The Illinois International Genetics of Stuttering Project and identified regions with nominal evidence for linkage on chromosomes 2 (P=0.013, 180–195 cM) and 5 (P=0.0051, 105–120 cM; P=0.015, 120–135 cM). None of the linkage signals detected in the Hutterite sample alone, or in the meta-analysis, meet genome-wide criteria for significance, although some of the stronger signals overlap linkage mapping signals previously reported for other speech and language disorders. PMID:17276504

  17. A novel genetic framework for studying response to artificial selection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Response to selection is fundamental to plant breeding. To gain insight into the genetic basis of response to selection, we propose a new experimental genetic framework to simultaneously map loci controlling specific traits associated with population improvement and characterize the allele frequenc...

  18. Exploring Genetic and Environmental Effects in Dysphonia: A Twin Study

    ERIC Educational Resources Information Center

    Simberg, Susanna; Santtila, Pekka; Soveri, Anna; Varjonen, Markus; Sala, Eeva; Sandnabba, N. Kenneth

    2009-01-01

    Purpose: To explore the existence of genetic effects as well as the interaction between potential genetic effects and a voice-demanding occupation on dysphonia. Method: One thousand seven hundred and twenty-eight Finnish twins (555 male; 1,173 female) born between 1961 and 1989 completed a questionnaire concerning vocal symptoms and occupation.…

  19. Combining case-control and case-trio data from the same population in genetic association analyses: overview of approaches and illustration with a candidate gene study.

    PubMed

    Infante-Rivard, Claire; Mirea, Lucia; Bull, Shelley B

    2009-09-01

    In genetic association studies, investigators compare allele or genotype frequencies in unrelated case and control subjects or examine preferential allele transmissions from parents to affected offspring. In many genetic case-control studies, the collection of DNA material extends to relatives such as parents of cases. Thus, case-control and case-parent trio association analyses are possible. Whereas the goal of collecting genetic information from family members in a study initially designed as a case-control study is to enrich the genetic analysis, increase power, or address concern about population structure bias, methods of combining genetic data from unrelated case and control subjects with genetic trio data from the same study population are not well known. A number of hybrid approaches have been developed that utilize such data together. In this paper, the authors describe key features of genetic case-control and case-parent trio studies and review commonly used methods of genetic analysis for case-parent trio designs. In addition, they provide a pragmatic review of statistical methods and available software for existing hybrid approaches that combine various components of case-control and genetic trio data. The application of all methods is illustrated using a candidate gene study of childhood leukemia that included case-control subjects and their parents. PMID:19635737

  20. A Robust Distribution-Free Test for Genetic Association Studies of Quantitative Traits

    PubMed Central

    Kozlitina, Julia; Schucany, William R.

    2016-01-01

    In association studies of quantitative traits, the association of each genetic marker with the trait of interest is typically tested using the F-test assuming an additive genetic model. In practice, the true model is rarely known, and specifying an incorrect model can lead to a loss of power. For case-control studies, the maximum of test statistics optimal for additive, dominant, and recessive models has been shown to be robust to model mis-specification. The approach has later been extended to quantitative traits. However, the existing procedures assume that the trait is normally distributed and may not maintain correct type-I error rates and can also have reduced power when the assumption of normality is violated. Here, we introduce a maximum (MAX3) test that is based on ranks and is therefore distribution-free. We examine the behavior of the proposed method using a Monte-Carlo simulation with both normal and non-normal data and compare the results to the usual parametric procedures and other nonparametric alternatives. We show that the rank-based maximum test has favorable properties relative to other tests, especially in the case of symmetric distributions with heavy tails. We illustrate the method with data from a real association study of symmetric dimethylarginine (SDMA). PMID:26426896

  1. Genetic regulation of bone strength: a review of animal model studies

    PubMed Central

    Adams, Douglas J; Ackert-Bicknell, Cheryl L

    2015-01-01

    Population- and family-based studies have established that fragility fracture risk is heritable; yet, the genome-wide association studies published to date have only accounted for a small fraction of the known variation for fracture risk of either the femur or the lumbar spine. Much work has been carried out using animal models toward finding genetic loci that are associated with bone strength. Studies using animal models overcome some of the issues associated with using patient data, but caution is needed when interpreting the results. In this review, we examine the types of tests that have been used for forward genetics mapping in animal models to identify loci and/or genes that regulate bone strength and discuss the limitations of these test methods. In addition, we present a summary of the quantitative trait loci that have been mapped for bone strength in mice, rats and chickens. The majority of these loci co-map with loci for bone size and/or geometry and thus likely dictate strength via modulating bone size. Differences in bone matrix composition have been demonstrated when comparing inbred strains of mice, and these matrix differences may be associated with differences in bone strength. However, additional work is needed to identify loci that act on bone strength at the materials level. PMID:26157577

  2. A genetic study and meta-analysis of the genetic predisposition of prostate cancer in a Chinese population

    PubMed Central

    Zhao, Shan-Chao; Ren, Guoping; Yu, Yongwei; Wu, Yudong; Wu, Ji; Xue, Yao; Zhou, Bo; Zhang, Yanling; Xu, Xingxing; Li, Jie; He, Weiyang; Benlloch, Sara; Ross-Adams, Helen; Chen, Li; Li, Jucong; Hong, Yingqia; Kote-Jarai, Zsofia; Cui, Xingang; Hou, Jianguo; Guo, Jianming; Xu, Lei; Yin, Changjun; Zhou, Yuanping; Neal, David E.; Oliver, Tim; Cao, Guangwen; Zhang, Zhengdong; Easton, Douglas F.; Chelala, Claude; Olama, Ali Amin Al; Eeles, Rosalind A.; Zhang, Hongwei; Lu, Yong-Jie

    2016-01-01

    Prostate cancer predisposition has been extensively investigated in European populations, but there have been few studies of other ethnic groups. To investigate prostate cancer susceptibility in the under-investigated Chinese population, we performed single-nucleotide polymorphism (SNP) array analysis on a cohort of Chinese cases and controls and then meta-analysis with data from the existing Chinese prostate cancer genome-wide association study (GWAS). Genotyping 211,155 SNPs in 495 cases and 640 controls of Chinese ancestry identified several new suggestive Chinese prostate cancer predisposition loci. However, none of them reached genome-wide significance level either by meta-analysis or replication study. The meta-analysis with the Chinese GWAS data revealed that four 8q24 loci are the main contributors to Chinese prostate cancer risk and the risk alleles from three of them exist at much higher frequencies in Chinese than European populations. We also found that several predisposition loci reported in Western populations have different effect on Chinese men. Therefore, this first extensive single-nucleotide polymorphism study of Chinese prostate cancer in comparison with European population indicates that four loci on 8q24 contribute to a great risk of prostate cancer in a considerable large proportion of Chinese men. Based on those four loci, the top 10% of the population have six- or two-fold prostate cancer risk compared with men of the bottom 10% or median risk respectively, which may facilitate the design of prostate cancer genetic risk screening and prevention in Chinese men. These findings also provide additional insights into the etiology and pathogenesis of prostate cancer. PMID:26881390

  3. Hamartomatous polyps - a clinical and molecular genetic study.

    PubMed

    Jelsig, Anne Marie

    2016-08-01

    Hamartomatous polyps (HPs) in the gastrointestinal (GI) tract are rare compared to other types of GI polyps, yet they are the most common type of polyp in children. The symptoms are usually rectal bleeding, abdominal pain, obstipation, anaemia, and/or small bowel obstruction. The polyps are typically removed concurrently with endoscopy when located in the colon, rectum, or stomach, whereas polyps in the small bowel are removed during push-enteroscopy, device-assisted enteroscopy, or by surgery. HPs can be classified as juvenile polyps or Peutz-Jeghers polyps based on their histopathological appearance. Patients with one or a few juvenile polyps are usually not offered clinical follow-up as the polyp(s) are considered not to harbour any malignant potential. Nevertheless, it is important to note that juvenile polyps and HPs are also found in patients with hereditary hamartomatous polyposis syndromes (HPS). Patients with HPS have an increased risk of cancer, recurrences of polyps, and extraintestinal complications. The syndromes are important to diagnose, as patients should be offered surveillance from childhood or early adolescence. The syndromes include juvenile polyposis syndrome, Peutz-Jeghers syndrome, and the PTEN hamartoma tumour syndrome. Currently, the HPS diagnoses are based on clinical criteria and are often assisted with genetic testing as candidate genes have been described for each syndrome. This thesis is based on six scientific papers. The overall aim of the studies was to expand the knowledge on clinical course and molecular genetics in patients with HPs and HPS, and to investigate research participants' attitude towards the results of extensive genetic testing.   Paper I: In the first paper we investigated the occurrence, anatomic distribution, and other demographics of juvenile polyps in the colon and rectum in Denmark in 1995-2014. Based on the Danish Pathology Data Bank we found that 1772 patients had 2108 JPs examined in the period, and we

  4. A direct anatomical study of additional renal arteries in a Colombian mestizo population.

    PubMed

    Saldarriaga, B; Pérez, A F; Ballesteros, L E

    2008-05-01

    Traditional anatomy describes each kidney as receiving irrigation from a single renal artery. However, current literature reports great variability in renal blood supply, the number of renal arteries mentioned being the most frequently found variation. Such variation has great implications when surgery is indicated, such as in renal transplants, uroradiological procedures, renovascular hypertension, renal trauma and hydronephrosis. This article pretends to determine the frequency of additional renal arteries and their morphological expression in Colombian population in a cross-sectional study. A total of 196 of renal blocks were analysed from autopsies carried out in the Bucaramanga Institute of Forensic Medicine, Colombia; these renal blocks were processed by the injection- corrosion technique. The average age of the people being studied was 33.8 +/- 15.6 years; 85.4% of them were male and the rest female. An additional renal artery was found in 22.3% of the whole population and two additional ones were found in 2.6% of the same sample. The additional renal artery was most frequently found on the left side. The additional artery arose from the aorta's lateral aspect (52.4%); these additional arteries usually entered the renal parenchyma through the hilum. No difference was established according to gender. Nearly a third of the Colombian population presents one additional renal artery and about 3% of the same population presents two additional renal arteries. Most of them reached the kidney through its hilar region. PMID:18521812

  5. A molecular genetic study of autism and related phenotypes in extended pedigrees

    PubMed Central

    2013-01-01

    Background Efforts to uncover the risk genotypes associated with the familial nature of autism spectrum disorder (ASD) have had limited success. The study of extended pedigrees, incorporating additional ASD-related phenotypes into linkage analysis, offers an alternative approach to the search for inherited ASD susceptibility variants that complements traditional methods used to study the genetics of ASD. Methods We examined evidence for linkage in 19 extended pedigrees ascertained through ASD cases spread across at least two (and in most cases three) nuclear families. Both compound phenotypes (i.e., ASD and, in non-ASD individuals, the broad autism phenotype) and more narrowly defined components of these phenotypes, e.g., social and repetitive behavior, pragmatic language, and anxiety, were examined. The overarching goal was to maximize the aggregate information available on the maximum number of individuals and to disaggregate syndromic phenotypes in order to examine the genetic underpinnings of more narrowly defined aspects of ASD behavior. Results Results reveal substantial between-family locus heterogeneity and support the importance of previously reported ASD loci in inherited, familial, forms of ASD. Additional loci, not seen in the ASD analyses, show evidence for linkage to the broad autism phenotype (BAP). BAP peaks are well supported by multiple subphenotypes (including anxiety, pragmatic language, and social behavior) showing linkage to regions overlapping with the compound BAP phenotype. Whereas 'repetitive behavior’, showing the strongest evidence for linkage (Posterior Probability of Linkage = 62% at 6p25.2-24.3, and 69% at 19p13.3), appears to be linked to novel regions not detected with other compound or narrow phenotypes examined in this study. Conclusions These results provide support for the presence of key features underlying the complexity of the genetic architecture of ASD: substantial between-family locus heterogeneity, that the BAP appears

  6. Genetic, Genomic and Epigenomic Studies of Balkan Endemic Nephropathy (Ben).

    PubMed

    Staneva, Rada G; Balabanski, L; Dimova, I; Rukova, B; Hadjidekova, S; Dimitrov, P; Simeonov, V; Ivanov, S; Vagarova, R; Malinov, M; Cukuranovic, R; Stefanovic, V; Polenakovic, M; Djonov, V; Galabov, A; Toncheva, D

    2015-01-01

    BEN is a primary, chronic tubulointerstitial nephritis characterized with chronic anemia, absence of edema, xantoderma, normal blood pressure and normal findings on the fundus oculi. The disease is distributed in restricted areas in Bulgaria, Romania, Croatia, Bosnia, Former Yugoslavia. Despite numerous studies on genetic and environmental factors and their possible involvement in BEN, its etiopathogenesis still remains elusive. Our recent study aim to elucidate the possible epigenetic component in BEN development. Whole genome DNA array methylation analysis was applied to compare the methylation profiles of male and female BEN patients from endemic regions in Bulgaria and Serbia and healthy controls. All three most prominent candidate genes with aberrations in the epigenetic profile discovered with this study are involved in the inflammatory/immune processes and oncogenesis. These data are in concordance with the reported pathological alterations in BEN. This research supports the role of epigenetic changes in BEN pathology. Exome sequencing of 22.000 genes with Illumina Nextera Exome Enrichment Kit revealed three mutant genes (CELA1, HSPG2, and KCNK5) in BEN patients which encode proteins involved in basement membrane/extracellular matrix and vascular tone, tightly connected to process of angiogenesis. We suggest that an abnormal process of angiogenesis plays a key role in the molecular pathogenesis of BEN. PMID:27442376

  7. Genetic Diversity in Gorkhas: an Autosomal STR Study.

    PubMed

    Preet, Kiran; Malhotra, Seema; Shrivastava, Pankaj; Jain, Toshi; Rawat, Shweta; Varte, L Robert; Singh, Sayar; Singh, Inderjeet; Sarkar, Soma

    2016-01-01

    Genotyping of highly polymorphic autosomal short tandem repeat (STR) markers is a potent tool for elucidating genetic diversity. In the present study, fifteen autosomal STR markers were analyzed in unrelated healthy male Gorkha individuals (n = 98) serving in the Indian Army by using AmpFlSTR Identifiler Plus PCR Amplification Kit. In total, 138 alleles were observed with corresponding allele frequencies ranging from 0.005 to 0.469. The studied loci were in Hardy-Weinberg Equilibrium (HWE). Heterozygosity ranged from 0.602 to 0.867. The most polymorphic locus was Fibrinogen Alpha (FGA) chain which was also the most discriminating locus as expected. Neighbor Joining (NJ) tree and principal component analysis (PCA) plot clustered the Gorkhas with those of Nepal and other Tibeto-Burman population while lowlander Indian population formed separate cluster substantiating the closeness of the Gorkhas with the Tibeto-Burman linguistic phyla. Furthermore, the dataset of STR markers obtained in the study presents a valuable information source of STR DNA profiles from personnel for usage in disaster victim identification in military exigencies and adds to the Indian database of military soldiers and military hospital repository. PMID:27580933

  8. Genetic Diversity in Gorkhas: an Autosomal STR Study

    PubMed Central

    Preet, Kiran; Malhotra, Seema; Shrivastava, Pankaj; Jain, Toshi; Rawat, Shweta; Varte, L. Robert; Singh, Sayar; Singh, Inderjeet; Sarkar, Soma

    2016-01-01

    Genotyping of highly polymorphic autosomal short tandem repeat (STR) markers is a potent tool for elucidating genetic diversity. In the present study, fifteen autosomal STR markers were analyzed in unrelated healthy male Gorkha individuals (n = 98) serving in the Indian Army by using AmpFlSTR Identifiler Plus PCR Amplification Kit. In total, 138 alleles were observed with corresponding allele frequencies ranging from 0.005 to 0.469. The studied loci were in Hardy-Weinberg Equilibrium (HWE). Heterozygosity ranged from 0.602 to 0.867. The most polymorphic locus was Fibrinogen Alpha (FGA) chain which was also the most discriminating locus as expected. Neighbor Joining (NJ) tree and principal component analysis (PCA) plot clustered the Gorkhas with those of Nepal and other Tibeto-Burman population while lowlander Indian population formed separate cluster substantiating the closeness of the Gorkhas with the Tibeto-Burman linguistic phyla. Furthermore, the dataset of STR markers obtained in the study presents a valuable information source of STR DNA profiles from personnel for usage in disaster victim identification in military exigencies and adds to the Indian database of military soldiers and military hospital repository. PMID:27580933

  9. Genetic analysis of tolerance to infections using random regressions: a simulation study.

    PubMed

    Kause, Antti

    2011-08-01

    Tolerance to infections is the ability of a host to limit the impact of a given pathogen burden on host performance. This simulation study demonstrated the merit of using random regressions to estimate unbiased genetic variances for tolerance slope and its genetic correlations with other traits, which could not be obtained using the previously implemented statistical methods. Genetic variance in tolerance was estimated as genetic variance in regression slopes of host performance along an increasing pathogen burden level. Random regressions combined with covariance functions allowed genetic variance for host performance to be estimated at any point along the pathogen burden trajectory, providing a novel means to analyse infection-induced changes in genetic variation of host performance. Yet, the results implied that decreasing family size as well as a non-zero environmental or genetic correlation between initial host performance before infection and pathogen burden led to biased estimates for tolerance genetic variance. In both cases, genetic correlation between tolerance slope and host performance in a pathogen-free environment became artificially negative, implying a genetic trade-off when it did not exist. Moreover, recording a normally distributed pathogen burden as a threshold trait is not a realistic way of obtaining unbiased estimates for tolerance genetic variance. The results show that random regressions are suitable for the genetic analysis of tolerance, given suitable data structure collected either under field or experimental conditions. PMID:21767462

  10. Genetic and environmental bases of childhood antisocial behavior: a multi-informant twin study.

    PubMed

    Baker, Laura A; Jacobson, Kristen C; Raine, Adrian; Lozano, Dora Isabel; Bezdjian, Serena

    2007-05-01

    Genetic and environmental influences on childhood antisocial and aggressive behavior (ASB) during childhood were examined in 9- to 10-year-old twins, using a multi-informant approach. The sample (605 families of twins or triplets) was socioeconomically and ethnically diverse, representative of the culturally diverse urban population in Southern California. Measures of ASB included symptom counts for conduct disorder, ratings of aggression, delinquency, and psychopathic traits obtained through child self-reports, teacher, and caregiver ratings. Multivariate analysis revealed a common ASB factor across informants that was strongly heritable (heritability was .96), highlighting the importance of a broad, general measure obtained from multiple sources as a plausible construct for future investigations of specific genetic mechanisms in ASB. The best fitting multivariate model required informant-specific genetic, environmental, and rater effects for variation in observed ASB measures. The results suggest that parents, children, and teachers have only a partly "shared view" and that the additional factors that influence the "rater-specific" view of the child's antisocial behavior vary for different informants. This is the first study to demonstrate strong heritable effects on ASB in ethnically and economically diverse samples. PMID:17516756

  11. Genetic and Environmental Bases of Childhood Antisocial Behavior: A Multi-Informant Twin Study

    PubMed Central

    Baker, Laura A.; Jacobson, Kristen C.; Raine, Adrian; Lozano, Dora Isabel; Bezdjian, Serena

    2007-01-01

    Genetic and environmental influences on childhood antisocial and aggressive behavior (ASB) during childhood were examined in 9- to 10-year-old twins, using a multi-informant approach. The sample (605 families of twins or triplets) was socioeconomically and ethnically diverse, representative of the culturally diverse urban population in Southern California. Measures of ASB included symptom counts for conduct disorder, ratings of aggression, delinquency, and psychopathic traits obtained through child self-reports, teacher, and caregiver ratings. Multivariate analysis revealed a common ASB factor across informants that was strongly heritable (heritability was .96), highlighting the importance of a broad, general measure obtained from multiple sources as a plausible construct for future investigations of specific genetic mechanisms in ASB. The best fitting multivariate model required informant-specific genetic, environmental, and rater effects for variation in observed ASB measures. The results suggest that parent, children, and teachers have only a partly “shared view” and that the additional factors that influence the “rater-specific” view of the child's antisocial behavior vary for different informants. This is the first study to demonstrate strong heritable effects on ASB in ethnically and economically diverse samples. PMID:17516756

  12. Optimal design of genetic studies of gene expression with two-color microarrays in outbred crosses.

    PubMed

    Lam, Alex C; Fu, Jingyuan; Jansen, Ritsert C; Haley, Chris S; de Koning, Dirk-Jan

    2008-11-01

    Combining global gene-expression profiling and genetic analysis of natural allelic variation (genetical genomics) has great potential in dissecting the genetic pathways underlying complex phenotypes. Efficient use of microarrays is paramount in experimental design as the cost of conducting this type of study is high. For those organisms where recombinant inbred lines are available for mapping, the "distant pair design" maximizes the number of informative contrasts over all marker loci. Here, we describe an extension of this design, named the "optimal pair design," for use with F2 crosses between outbred lines. The performance of this design is investigated by simulation and compared to several other two-color microarray designs. We show that, for a given number of microarrays, the optimal pair design outperforms all other designs considered for detection of expression quantitative trait loci (eQTL) with additive effects by linkage analysis. We also discuss the suitability of this design for outbred crosses in organisms with large genomes and for detection of dominance. PMID:18791249

  13. Simulating a base population in honey bee for molecular genetic studies

    PubMed Central

    2012-01-01

    Background Over the past years, reports have indicated that honey bee populations are declining and that infestation by an ecto-parasitic mite (Varroa destructor) is one of the main causes. Selective breeding of resistant bees can help to prevent losses due to the parasite, but it requires that a robust breeding program and genetic evaluation are implemented. Genomic selection has emerged as an important tool in animal breeding programs and simulation studies have shown that it yields more accurate breeding value estimates, higher genetic gain and low rates of inbreeding. Since genomic selection relies on marker data, simulations conducted on a genomic dataset are a pre-requisite before selection can be implemented. Although genomic datasets have been simulated in other species undergoing genetic evaluation, simulation of a genomic dataset specific to the honey bee is required since this species has a distinct genetic and reproductive biology. Our software program was aimed at constructing a base population by simulating a random mating honey bee population. A forward-time population simulation approach was applied since it allows modeling of genetic characteristics and reproductive behavior specific to the honey bee. Results Our software program yielded a genomic dataset for a base population in linkage disequilibrium. In addition, information was obtained on (1) the position of markers on each chromosome, (2) allele frequency, (3) χ2 statistics for Hardy-Weinberg equilibrium, (4) a sorted list of markers with a minor allele frequency less than or equal to the input value, (5) average r2 values of linkage disequilibrium between all simulated marker loci pair for all generations and (6) average r2 value of linkage disequilibrium in the last generation for selected markers with the highest minor allele frequency. Conclusion We developed a software program that takes into account the genetic and reproductive biology specific to the honey bee and that can be used to

  14. Genetic systems for studying obligate intracellular pathogens: an update.

    PubMed

    Wood, David O; Wood, Raphael R; Tucker, Aimee M

    2014-02-01

    Rapid advancements in the genetic manipulation of obligate intracellular bacterial pathogens have been made over the past two years. In this paper we attempt to summarize the work published since 2011 that documents these exciting accomplishments. Although each genus comprising this diverse group of pathogens poses unique problems, requiring modifications of established techniques and the introduction of new tools, all appear amenable to genetic analysis. Significantly, the field is moving forward from a focus on the identification and development of genetic techniques to their application in addressing crucial questions related to mechanisms of bacterial pathogenicity and the requirements of obligate intracellular growth. PMID:24581687

  15. Genetic Influences on Brain Developmental Trajectories on Neuroimaging Studies: From Infancy to Young Adulthood

    PubMed Central

    Douet, Vanessa; Chang, Linda; Cloak, Christine; Ernst, Thomas

    2013-01-01

    Human brain development has been studied intensively with neuroimaging. However, little is known about how genes influence developmental brain trajectories, even though a significant number of genes (about 10,000, or approximately one-third) in the human genome are expressed primarily in the brain and during brain development. Interestingly, in addition to showing differential expression among tissues, many genes are differentially expressed across the ages (e.g., antagonistic pleiotropy). Age-specific gene expression plays an important role in several critical events in brain development, including neuronal cell migration, synaptogenesis and neurotransmitter receptor specificity, as well as in aging and neurodegenerative disorders (e.g., Alzheimer disease or amyotrophic lateral sclerosis). In addition, the majority of psychiatric and mental disorders are polygenic, and many have onsets during childhood and adolescence. In this review, we summarize the major findings from neuroimaging studies that link genetics with brain development, from infancy to young adulthood. Specifically, we focus on the heritability of brain structures across the ages, age-related genetic influences on brain development and sex-specific developmental trajectories. PMID:24077983

  16. Rate of evolutionary change in cranial morphology of the marsupial genus Monodelphis is constrained by the availability of additive genetic variation.

    PubMed

    Porto, A; Sebastião, H; Pavan, S E; VandeBerg, J L; Marroig, G; Cheverud, J M

    2015-04-01

    We tested the hypothesis that the rate of marsupial cranial evolution is dependent on the distribution of genetic variation in multivariate space. To do so, we carried out a genetic analysis of cranial morphological variation in laboratory strains of Monodelphis domestica and used estimates of genetic covariation to analyse the morphological diversification of the Monodelphis brevicaudata species group. We found that within-species genetic variation is concentrated in only a few axes of the morphospace and that this strong genetic covariation influenced the rate of morphological diversification of the brevicaudata group, with between-species divergence occurring fastest when occurring along the genetic line of least resistance. Accounting for the geometric distribution of genetic variation also increased our ability to detect the selective regimen underlying species diversification, with several instances of selection only being detected when genetic covariances were taken into account. Therefore, this work directly links patterns of genetic covariation among traits to macroevolutionary patterns of morphological divergence. Our findings also suggest that the limited distribution of Monodelphis species in morphospace is the result of a complex interplay between the limited dimensionality of available genetic variation and strong stabilizing selection along two major axes of genetic variation. PMID:25818173

  17. Rate of evolutionary change in cranial morphology of the marsupial genus Monodelphis is constrained by the availability of additive genetic variation

    PubMed Central

    Porto, Arthur; Sebastião, Harley; Pavan, Silvia Eliza; VandeBerg, John L.; Marroig, Gabriel; Cheverud, James M.

    2015-01-01

    We tested the hypothesis that the rate of marsupial cranial evolution is dependent on the distribution of genetic variation in multivariate space. To do so, we carried out a genetic analysis of cranial morphological variation in laboratory strains of Monodelphis domestica and used estimates of genetic covariation to analyze the morphological diversification of the Monodelphis brevicaudata species group. We found that within-species genetic variation is concentrated in only a few axes of the morphospace and that this strong genetic covariation influenced the rate of morphological diversification of the brevicaudata group, with between-species divergence occurring fastest when occurring along the genetic line of least resistance. Accounting for the geometric distribution of genetic variation also increased our ability to detect the selective regimen underlying species diversification, with several instances of selection only being detected when genetic covariances were taken into account. Therefore, this work directly links patterns of genetic covariation among traits to macroevolutionary patterns of morphological divergence. Our findings also suggest that the limited distribution of Monodelphis species in morphospace is the result of a complex interplay between the limited dimensionality of available genetic variation and strong stabilizing selection along two major axes of genetic variation. PMID:25818173

  18. Genome-wide analysis of BMI in adolescents and young adults reveals additional insight into the effects of genetic loci over the life course

    PubMed Central

    Graff, Mariaelisa; Ngwa, Julius S.; Workalemahu, Tsegaselassie; Homuth, Georg; Schipf, Sabine; Teumer, Alexander; Völzke, Henry; Wallaschofski, Henri; Abecasis, Goncalo R.; Edward, Lakatta; Francesco, Cucca; Sanna, Serena; Scheet, Paul; Schlessinger, David; Sidore, Carlo; Xiao, Xiangjun; Wang, Zhaoming; Chanock, Stephen J.; Jacobs, Kevin B.; Hayes, Richard B.; Hu, Frank; Van Dam, Rob M.; Crout, Richard J.; Marazita, Mary L.; Shaffer, John R; Atwood, Larry D.; Fox, Caroline S.; Heard-Costa, Nancy L.; White, Charles; Choh, Audrey C.; Czerwinski, Stefan A.; Demerath, Ellen W.; Dyer, Thomas D.; Towne, Bradford; Amin, Najaf; Oostra, Ben A.; Van Duijn, Cornelia M.; Zillikens, M. Carola; Esko, Tõnu; Nelis, Mari; Nikopensius, Tit; Metspalu, Andres; Strachan, David P.; Monda, Keri; Qi, Lu; North, Kari E.; Cupples, L. Adrienne; Gordon-Larsen, Penny; Berndt, Sonja I.

    2013-01-01

    Genetic loci for body mass index (BMI) in adolescence and young adulthood, a period of high risk for weight gain, are understudied, yet may yield important insight into the etiology of obesity and early intervention. To identify novel genetic loci and examine the influence of known loci on BMI during this critical time period in late adolescence and early adulthood, we performed a two-stage meta-analysis using 14 genome-wide association studies in populations of European ancestry with data on BMI between ages 16 and 25 in up to 29 880 individuals. We identified seven independent loci (P < 5.0 × 10−8) near FTO (P = 3.72 × 10−23), TMEM18 (P = 3.24 × 10−17), MC4R (P = 4.41 × 10−17), TNNI3K (P = 4.32 × 10−11), SEC16B (P = 6.24 × 10−9), GNPDA2 (P = 1.11 × 10−8) and POMC (P = 4.94 × 10−8) as well as a potential secondary signal at the POMC locus (rs2118404, P = 2.4 × 10−5 after conditioning on the established single-nucleotide polymorphism at this locus) in adolescents and young adults. To evaluate the impact of the established genetic loci on BMI at these young ages, we examined differences between the effect sizes of 32 published BMI loci in European adult populations (aged 18–90) and those observed in our adolescent and young adult meta-analysis. Four loci (near PRKD1, TNNI3K, SEC16B and CADM2) had larger effects and one locus (near SH2B1) had a smaller effect on BMI during adolescence and young adulthood compared with older adults (P < 0.05). These results suggest that genetic loci for BMI can vary in their effects across the life course, underlying the importance of evaluating BMI at different ages. PMID:23669352

  19. Genetic analysis of advanced glycation end products in the DHS MIND study.

    PubMed

    Adams, Jeremy N; Raffield, Laura M; Martelle, Susan E; Freedman, Barry I; Langefeld, Carl D; Carr, J Jeffrey; Cox, Amanda J; Bowden, Donald W

    2016-06-15

    Advanced glycation end-products (AGEs) are a diverse group of molecules produced by the non-enzymatic addition of glucose to proteins, lipids, and nucleic acids. AGE levels have been associated with hyperglycemia and diabetic complications, especially in animal models, but less clearly in human studies. We measured total serum AGEs using an enzyme linked immunosorbant assay (ELISA) in 506 subjects from 246 families in the Diabetes Heart Study (DHS)/DHS MIND Study (n=399 type 2 diabetes (T2D)-affected). Single nucleotide polymorphisms (SNPs) in several candidate genes, including known AGE receptors, were tested for their influence on circulating AGE levels. The genetic analysis was expanded to include an exploratory genome-wide association study (GWAS) and exome chip analysis of AGEs (≈440,000 SNPs). AGEs were found to be highly heritable (h(2)=0.628, p=8.96 × 10(-10)). While no SNPs from candidate genes were significantly associated after Bonferroni correction, rs1035798 in the gene AGER was the most significantly associated (p=0.007). Additionally, rs7198427, in MT1A, showed a nominally significant p-value (p=0.0099). No SNPs from the GWAS or exome studies were identified after correction for multiple comparisons; however, rs17054480 in the PALLD2 gene on chromosome 4 showed the strongest association (p=7.77 × 10(-7)). Five SNPs at two loci (ISCA2/NPC2 and FBXO33) had p-values of less than 2.0 × 10(-5) and three additional SNPs (rs716326 in MACROD2, and rs6795197 and rs6765857 in ZBTB38) showed a nominal association with p-values of less than 1.0 × 10(-5).These findings provide a foundation for further investigation into the genetic component of circulating AGEs. PMID:26915486

  20. Additional short-term plutonium urinary excretion data from the 1945-1947 plutonium injection studies

    SciTech Connect

    Moss, W.D.; Gautier, M.A.

    1986-01-01

    The amount of plutonium excreted per day following intravenous injection was shown to be significantly higher than predicted by the Langham power function model. Each of the Los Alamos National Laboratory notebooks used to record the original analytical data was studied for details that could influence the findings. It was discovered there were additional urine excretion data for case HP-3. This report presents the additional data, as well as data on case HP-6. (ACR)

  1. From genetic associations to functional studies in multiple sclerosis.

    PubMed

    Bos, S D; Berge, T; Celius, E G; Harbo, H F

    2016-05-01

    Genetic screens steadily reveal more loci that show robust associations to complex human diseases, including multiple sclerosis (MS). Although some of the identified genetic variants are easily interpreted into a biological function, most of the genetic associations are frequently challenging to interpret. Underlying these difficulties is the fact that chip-based assays typically detect single nucleotide polymorphisms (SNPs) representative of a stretch of DNA containing many genomic variants in linkage disequilibrium. Furthermore, a large proportion of the SNPs with strongest association to MS are located in regions of the DNA that do not directly code for proteins. Here we discuss challenges faced by MS researchers to follow up the large-scale genetic screens that have been published over the past years in search of functional consequences of the identified MS-associated SNPs. We discuss experimental design, tools and methods that may provide the much-needed biological insights in both disease etiology and disease manifestations. PMID:26948534

  2. Genetic transformation: a tool to study protein targeting in diatoms.

    PubMed

    Kroth, Peter G

    2007-01-01

    Diatoms are unicellular photoautotrophic eukaryotes that play an important role in ecology by fixing large amounts of CO2 in the oceans. Because they evolved by secondary endocytobiosis-- a process of uptake of a eukaryotic alga into another eukaryotic cell--they have a rather unusual cell biology and genetic constitution. Because the preparation of organelles is rather difficult as a result of the cytosolic structures, genetic transformation and expression of preproteins fused to green fluorescent protein (GFP) became one of the major tools to analyze subcellular localization of proteins in diatoms. Meanwhile several groups successfully attempted to develop genetic transformation protocols for diatoms. These methods are based on "biolistic" DNA delivery via a particle gun and allow the introduction and expression of foreign genes in the algae. Here a protocol for the genetic transformation of the diatom Phaeodactylum tricornutum is described as well as the subsequent characterization of the transformants. PMID:17951693

  3. "Genetic Engineering" Gains Momentum (Science/Society Case Study).

    ERIC Educational Resources Information Center

    Moore, John W.; Moore, Elizabeth A., Eds.

    1980-01-01

    Reviews the benefits and hazards of genetic engineering, or "recombinant-DNA" research. Recent federal safety rules issued by NIH which ease the strict prohibitions on recombinant-DNA research are explained. (CS)

  4. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 11 2014-01-01 2014-01-01 false Engineering and cost studies-addition of generation capacity. 1710.253 Section 1710.253 Agriculture Regulations of the Department of Agriculture (Continued... TO ELECTRIC LOANS AND GUARANTEES Construction Work Plans and Related Studies § 1710.253...

  5. Evaluating Drugs and Food Additives for Public Use: A Case Studies Approach.

    ERIC Educational Resources Information Center

    Merritt, Sheridan V.

    1980-01-01

    Described is a case study used in an introductory college biology course that provides a basis for generating debate on an issue concerning the regulation of controversial food additives and prescription drugs. The case study contained within this article deals with drug screening, specifically with information related to thalidomide. (CS)

  6. A registry-based study of thyroid paraganglioma: histological and genetic characteristics.

    PubMed

    von Dobschuetz, Ernst; Leijon, Helena; Schalin-Jäntti, Camilla; Schiavi, Francesca; Brauckhoff, Michael; Peczkowska, Mariola; Spiazzi, Giovanna; Demattè, Serena; Cecchini, Maria Enrica; Sartorato, Paola; Krajewska, Jolanta; Hasse-Lazar, Kornelia; Roszkowska-Purska, Katarzyna; Taschin, Elisa; Malinoc, Angelica; Akslen, Lars A; Arola, Johanna; Lange, Dariusz; Fassina, Ambrogio; Pennelli, Gianmaria; Barbareschi, Mattia; Luettges, Jutta; Prejbisz, Aleksander; Januszewicz, Andrzej; Strate, Tim; Bausch, Birke; Castinetti, Frederic; Jarzab, Barbara; Opocher, Giuseppe; Eng, Charis; Neumann, Hartmut P H

    2015-04-01

    The precise diagnosis of thyroid neoplasias will guide surgical management. Primary thyroid paraganglioma has been rarely reported. Data on prevalence, immunohistochemistry (IHC), and molecular genetics in a systematic series of such patients are pending. We performed a multinational population-based study on thyroid paraganglioma and analyzed prevalence, IHC, and molecular genetics. Patients with thyroid paraganglioma were recruited from the European-American-Head-and-Neck-Paraganglioma-Registry. Demographic and clinical data were registered. Histopathology and IHC were re-investigated. All patients with thyroid paraganglioma underwent molecular genetic analyses of the SDHA, SDHB, SDHC, SDHD, SDHAF2, VHL, RET, TMEM127, and MAX genes. Analyses included Sanger sequencing and multiplex ligation-dependent probe amplification (MLPA) for detection of large rearrangements. Of 947 registrants, eight candidates were initially identified. After immunohistochemical analyses of these eight subjects, 5 (0.5%) were confirmed to have thyroid paraganglioma. IHC was positive for chromogranin, synaptophysin, and S-100 and negative for calcitonin in all five thyroid paragangliomas, whereas the three excluded candidate tumors stained positive for pan-cytokeratin, a marker excluding endocrine tumors. Germline variants, probably representing mutations, were found in four of the five confirmed thyroid paraganglioma cases, two each in SDHA and SDHB, whereas the excluded cases had no mutations in the tested genes. Thyroid paraganglioma is a finite entity, which must be differentiated from medullary thyroid carcinoma, because medical, surgical, and genetic management for each is different. Notably, approximately 80% of thyroid paragangliomas are associated with germline variants, with implications for additional tumors and a potential risk for the family. As opposed to sporadic tumors, surgical management and extent of resection are different for heritable tumors, each guided by the

  7. Dissociable Genetic Contributions to Error Processing: A Multimodal Neuroimaging Study

    PubMed Central

    Agam, Yigal; Vangel, Mark; Roffman, Joshua L.; Gallagher, Patience J.; Chaponis, Jonathan; Haddad, Stephen; Goff, Donald C.; Greenberg, Jennifer L.; Wilhelm, Sabine; Smoller, Jordan W.; Manoach, Dara S.

    2014-01-01

    Background Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN), an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC). While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation. Methods We measured both error markers in a sample of 92 comprised of healthy individuals and those with diagnoses of schizophrenia, obsessive-compulsive disorder or autism spectrum disorder. Participants performed the same task during functional MRI and simultaneously acquired magnetoencephalography and electroencephalography. We examined the mediation of the error markers by two single nucleotide polymorphisms: dopamine D4 receptor (DRD4) C-521T (rs1800955), which has been associated with the ERN and methylenetetrahydrofolate reductase (MTHFR) C677T (rs1801133), which has been associated with error-related dACC activation. We then compared the effects of each polymorphism on the two error markers modeled as a bivariate response. Results We replicated our previous report of a posterior cingulate source of the ERN in healthy participants in the schizophrenia and obsessive-compulsive disorder groups. The effect of genotype on error markers did not differ significantly by diagnostic group. DRD4 C-521T allele load had a significant linear effect on ERN amplitude, but not on dACC activation, and this difference was significant. MTHFR C677T allele load had a significant linear effect on dACC activation but not ERN amplitude, but the difference in effects on the two error markers was not significant. Conclusions DRD4 C-521T, but not MTHFR C677T, had a significant differential effect on two canonical error markers. Together with the anatomical dissociation between the ERN and error-related dACC activation

  8. Holt-Oram syndrome: a clinical genetic study.

    PubMed Central

    Newbury-Ecob, R A; Leanage, R; Raeburn, J A; Young, I D

    1996-01-01

    A clinical and genetic study of the Holt-Oram syndrome (HOS) has been carried out in the United Kingdom involving 55 cases designated Holt-Oram syndrome, together with their parents and sibs. Data from the clinical assessment of both familial and isolated cases were used to define the HOS phenotype and to outline the spectrum of abnormalities, especially factors affecting severity. Skeletal defects affected the upper limbs exclusively and were bilateral and asymmetrical. They ranged from minor signs such as clinodactyly, limited supination, and sloping shoulders to severe reduction deformities of the upper arm (4.5%). The radial ray was predominantly affected than the right. All affected cases showed evidence of upper limb involvement. Cardiac defects were seen in 95% of familial cases and included both atrial septal defect (ASD, 34%) and ventricular septal defect (VSD, 25%); 39% had only ECG changes. Cardiac involvement ranged from asymptomatic conduction disturbances to multiple structural defects requiring surgery in infancy. Sudden death could be caused by heart block. Inheritance was autosomal dominant with 100% penetrance and no evidence of reduced fitness. Increasing severity occurred in succeeding generations consistent with anticipation. Images PMID:8730285

  9. Genetic Models for the Study of Luteinizing Hormone Receptor Function

    PubMed Central

    Narayan, Prema

    2015-01-01

    The luteinizing hormone/chorionic gonadotropin receptor (LHCGR) is essential for fertility in men and women. LHCGR binds luteinizing hormone (LH) as well as the highly homologous chorionic gonadotropin. Signaling from LHCGR is required for steroidogenesis and gametogenesis in males and females and for sexual differentiation in the male. The importance of LHCGR in reproductive physiology is underscored by the large number of naturally occurring inactivating and activating mutations in the receptor that result in reproductive disorders. Consequently, several genetically modified mouse models have been developed for the study of LHCGR function. They include targeted deletion of LH and LHCGR that mimic inactivating mutations in hormone and receptor, expression of a constitutively active mutant in LHCGR that mimics activating mutations associated with familial male-limited precocious puberty and transgenic models of LH and hCG overexpression. This review summarizes the salient findings from these models and their utility in understanding the physiological and pathological consequences of loss and gain of function in LHCGR signaling. PMID:26483755

  10. Phenotype-Based Genetic Association Studies (PGAS)—Towards Understanding the Contribution of Common Genetic Variants to Schizophrenia Subphenotypes

    PubMed Central

    Ehrenreich, Hannelore; Nave, Klaus-Armin

    2014-01-01

    Neuropsychiatric diseases ranging from schizophrenia to affective disorders and autism are heritable, highly complex and heterogeneous conditions, diagnosed purely clinically, with no supporting biomarkers or neuroimaging criteria. Relying on these “umbrella diagnoses”, genetic analyses, including genome-wide association studies (GWAS), were undertaken but failed to provide insight into the biological basis of these disorders. “Risk genotypes” of unknown significance with low odds ratios of mostly <1.2 were extracted and confirmed by including ever increasing numbers of individuals in large multicenter efforts. Facing these results, we have to hypothesize that thousands of genetic constellations in highly variable combinations with environmental co-factors can cause the individual disorder in the sense of a final common pathway. This would explain why the prevalence of mental diseases is so high and why mutations, including copy number variations, with a higher effect size than SNPs, constitute only a small part of variance. Elucidating the contribution of normal genetic variation to (disease) phenotypes, and so re-defining disease entities, will be extremely labor-intense but crucial. We have termed this approach PGAS (“phenotype-based genetic association studies”). Ultimate goal is the definition of biological subgroups of mental diseases. For that purpose, the GRAS (Göttingen Research Association for Schizophrenia) data collection was initiated in 2005. With >3000 phenotypical data points per patient, it comprises the world-wide largest currently available schizophrenia database (N > 1200), combining genome-wide SNP coverage and deep phenotyping under highly standardized conditions. First PGAS results on normal genetic variants, relevant for e.g., cognition or catatonia, demonstrated proof-of-concept. Presently, an autistic subphenotype of schizophrenia is being defined where an unfortunate accumulation of normal genotypes, so-called pro

  11. Fitting additive hazards models for case-cohort studies: a multiple imputation approach.

    PubMed

    Jung, Jinhyouk; Harel, Ofer; Kang, Sangwook

    2016-07-30

    In this paper, we consider fitting semiparametric additive hazards models for case-cohort studies using a multiple imputation approach. In a case-cohort study, main exposure variables are measured only on some selected subjects, but other covariates are often available for the whole cohort. We consider this as a special case of a missing covariate by design. We propose to employ a popular incomplete data method, multiple imputation, for estimation of the regression parameters in additive hazards models. For imputation models, an imputation modeling procedure based on a rejection sampling is developed. A simple imputation modeling that can naturally be applied to a general missing-at-random situation is also considered and compared with the rejection sampling method via extensive simulation studies. In addition, a misspecification aspect in imputation modeling is investigated. The proposed procedures are illustrated using a cancer data example. Copyright © 2015 John Wiley & Sons, Ltd. PMID:26194861

  12. Considering trauma exposure in the context of genetics studies of posttraumatic stress disorder: a systematic review

    PubMed Central

    2013-01-01

    Background Posttraumatic stress disorder (PTSD) is a debilitating anxiety disorder. Surveys of the general population suggest that while 50-85% of Americans will experience a traumatic event in their lifetime, only 2-50% will develop PTSD. Why some individuals develop PTSD following trauma exposure while others remain resilient is a central question in the field of trauma research. For more than half a century, the role of genetic influences on PTSD has been considered as a potential vulnerability factor. However, despite the exponential growth of molecular genetic studies over the past decade, limited progress has been made in identifying true genetic variants for PTSD. Methods In an attempt to aid future genome wide association studies (GWAS), this paper presents a systematic review of 28 genetic association studies of PTSD. Inclusion criteria required that 1) all participants were exposed to Criterion A traumatic events, 2) polymorphisms of relevant genes were genotyped and assessed in relation to participants’ PTSD status, 3) quantitative methods were used, and 4) articles were published in English and in peer-reviewed journals. In the examination of these 28 studies, particular attention was given to variables related to trauma exposure (e.g. number of traumas, type of trauma). Results Results indicated that most articles did not report on the GxE interaction in the context of PTSD or present data on the main effects of E despite having data available. Furthermore, some studies that did consider the GxE interaction had significant findings, underscoring the importance of examining how genotypes can modify the effect of trauma on PTSD. Additionally, results indicated that only a small number of genes continue to be studied and that there were marked differences in methodologies across studies, which subsequently limited robust conclusions. Conclusions As trauma exposure is a necessary condition for the PTSD diagnosis, this paper identifies gaps in the current

  13. Substantial genetic link between IQ and working memory: implications for molecular genetic studies on schizophrenia. the European twin study of schizophrenia (EUTwinsS).

    PubMed

    Goldberg, Ximena; Alemany, Silvia; Rosa, Araceli; Picchioni, Marco; Nenadic, Igor; Owens, Sheena F; Rijsdijk, Fruhling; Rebollo, Irene; Sauer, Heinrich; Murray, Robin M; Fañanás, Lourdes; Toulopoulou, Timothea

    2013-06-01

    While evidence is accumulating to support specific neurocognitive deficits as putative endophenotypes for schizophrenia, the heritability of these deficits in healthy subjects and whether they share common genetic influences, is not well established. In the present study, 529 healthy adult twins from two centers within the European Twin Study Network on Schizophrenia (EUTwinsS) were assessed on two domains that are consistently found to be particularly compromised in schizophrenia. Specifically, Intellectual Quotient Score (IQ) and the Letter-Number Sequencing Test (LNS), a measure of working memory, were measured in all twins. Latent variable components were explored through structural equation modeling, and common genetic underpinnings were examined using bivariate analyses. Results showed that the phenotypic correlation between IQ and working memory was almost entirely attributed to shared genetic variance (95.5%). We discuss the potential use of a combined measure of IQ and working memory to improve the power of molecular studies in detecting the genetic mechanisms underlying schizophrenia. PMID:23650229

  14. [TG-FTIR study on pyrolysis of wheat-straw with abundant CaO additives].

    PubMed

    Han, Long; Wang, Qin-Hui; Yang, Yu-Kun; Yu, Chun-Jiang; Fang, Meng-Xiang; Luo, Zhong-Yang

    2011-04-01

    Biomass pyrolysis in presence of abundant CaO additives is a fundamental process prior to CaO sorption enhanced gasification in biomass-based zero emission system. In the present study, thermogravimetric Fourier transform infrared (TG-FTIR) analysis was adopted to examine the effects of CaO additives on the mass loss process and volatiles evolution of wheat-straw pyrolysis. Observations from TG and FTIR analyses simultaneously demonstrated a two-stage process for CaO catalyzed wheat-straw pyrolysis, different from the single stage process for pure wheat-straw pyrolysis. CaO additives could not only absorb the released CO2 but also reduce the yields of tar species such as toluene, phenol, and formic acid in the first stage, resulting in decreased mass loss and maximum mass loss rate in this stage with an increase in CaO addition. The second stage was attributed to the CaCO3 decomposition and the mass loss and maximum mass loss rate increased with increasing amount of CaO additives. The results of the present study demonstrated the great potential of CaO additives to capture CO2 and reduce tars yields in biomass-based zero emission system. The gasification temperature in the system should be lowered down to avoid CaCO3 decomposition. PMID:21714234

  15. Bloat control operators and diversity in genetic programming: a comparative study.

    PubMed

    Alfaro-Cid, E; Merelo, J J; Fernández de Vega, F; Esparcia-Alcázar, A I; Sharman, K

    2010-01-01

    This paper reports a comparison of several bloat control methods and also evaluates a recent proposal for limiting the size of the individuals: a genetic operator called prune and plant. The aim of this work is to test the adequacy of this method. Since a preliminary study of the method has already shown promising results, we have performed a thorough study in a set of benchmark problems aiming at demonstrating the utility of the new approach. Prune and plant has obtained results that maintain the quality of the final solutions in terms of fitness while achieving a substantial reduction of the mean tree size in all four problem domains considered. In addition, in one of these problem domains, prune and plant has demonstrated to be better in terms of fitness, size reduction, and time consumption than any of the other bloat control techniques under comparison. The experimental part of the study presents a comparison of performance in terms of phenotypic and genotypic diversity. This comparison study can provide the practitioner with some relevant clues as to which bloat control method is better suited to a particular problem and whether the advantage of a method does or does not derive from its influence on the genetic pool diversity. PMID:20210598

  16. Genetics of familial hypercholesterolemia.

    PubMed

    Brautbar, Ariel; Leary, Emili; Rasmussen, Kristen; Wilson, Don P; Steiner, Robert D; Virani, Salim

    2015-04-01

    Familial hypercholesterolemia (FH) is a genetic disorder characterized by elevated low-density lipoprotein (LDL) cholesterol and premature cardiovascular disease, with a prevalence of approximately 1 in 200-500 for heterozygotes in North America and Europe. Monogenic FH is largely attributed to mutations in the LDLR, APOB, and PCSK9 genes. Differential diagnosis is critical to distinguish FH from conditions with phenotypically similar presentations to ensure appropriate therapeutic management and genetic counseling. Accurate diagnosis requires careful phenotyping based on clinical and biochemical presentation, validated by genetic testing. Recent investigations to discover additional genetic loci associated with extreme hypercholesterolemia using known FH families and population studies have met with limited success. Here, we provide a brief overview of the genetic determinants, differential diagnosis, genetic testing, and counseling of FH genetics. PMID:25712136

  17. SHEEP MOUNTAIN WILDERNESS STUDY AREA AND CUCAMONGA WILDERNESS AND ADDITIONS, CALIFORNIA.

    USGS Publications Warehouse

    Evans, James G.; Ridenour, James

    1984-01-01

    The Sheep Mountain Wilderness Study Area and Cucamonga Wilderness and additions encompass approximately 104 sq mi of the eastern San Gabriel Mountains, Los Angeles and San Bernardino Counties, California. A mineral survey indicates areas of probable and substantiated tungsten and gold resource potential for parts of the Sheep Mountain Wilderness Study Area and an area of probable tungsten and gold resource potential in the Cucamonga Wilderness and additions. The rugged topography, withdrawal of lands from mineral entry to protect watershed, and restricted entry of lands during periods of high fire danger have contributed to the continuing decline in mineral exploration. The geologic setting precludes the presence of energy resources.

  18. Influence of Polarization on Carbohydrate Hydration: A Comparative Study Using Additive and Polarizable Force Fields.

    PubMed

    Pandey, Poonam; Mallajosyula, Sairam S

    2016-07-14

    Carbohydrates are known to closely modulate their surrounding solvent structures and influence solvation dynamics. Spectroscopic investigations studying far-IR regions (below 1000 cm(-1)) have observed spectral shifts in the libration band (around 600 cm(-1)) of water in the presence of monosaccharides and polysaccharides. In this paper, we use molecular dynamics simulations to gain atomistic insight into carbohydrate-water interactions and to specifically highlight the differences between additive (nonpolarizable) and polarizable simulations. A total of six monosaccharide systems, α and β anomers of glucose, galactose, and mannose, were studied using additive and polarizable Chemistry at HARvard Macromolecular Mechanics (CHARMM) carbohydrate force fields. Solvents were modeled using three additive water models TIP3P, TIP4P, and TIP5P in additive simulations and polarizable water model SWM4 in polarizable simulations. The presence of carbohydrate has a significant effect on the microscopic water structure, with the effects being pronounced for proximal water molecules. Notably, disruption of the tetrahedral arrangement of proximal water molecules was observed due to the formation of strong carbohydrate-water hydrogen bonds in both additive and polarizable simulations. However, the inclusion of polarization resulted in significant water-bridge occupancies, improved ordered water structures (tetrahedral order parameter), and longer carbohydrate-water H-bond correlations as compared to those for additive simulations. Additionally, polarizable simulations also allowed the calculation of power spectra from the dipole-dipole autocorrelation function, which corresponds to the IR spectra. From the power spectra, we could identify spectral signatures differentiating the proximal and bulk water structures, which could not be captured from additive simulations. PMID:27266974

  19. Genetic Studies of Quantitative MCI and AD Phenotypes in ADNI: Progress, Opportunities, and Plans

    PubMed Central

    Saykin, Andrew J.; Shen, Li; Yao, Xiaohui; Kim, Sungeun; Nho, Kwangsik; Risacher, Shannon L.; Ramanan, Vijay K.; Foroud, Tatiana M.; Faber, Kelly M.; Sarwar, Nadeem; Munsie, Leanne M.; Hu, Xiaolan; Soares, Holly D.; Potkin, Steven G.; Thompson, Paul M.; Kauwe, John S.K.; Kaddurah-Daouk, Rima; Green, Robert C.; Toga, Arthur W.; Weiner, Michael W.

    2015-01-01

    INTRODUCTION Genetic data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) has been crucial in advancing the understanding of AD pathophysiology. Here we provide an update on sample collection, scientific progress and opportunities, conceptual issues, and future plans. METHODS Lymphoblastoid cell lines and DNA and RNA samples from blood have been collected and banked, and data and biosamples have been widely disseminated. To date, APOE genotyping, genome-wide association study (GWAS), and whole exome and whole genome sequencing (WES, WGS) data have been obtained and disseminated. RESULTS ADNI genetic data have been downloaded thousands of times and over 300 publications have resulted, including reports of large scale GWAS by consortia to which ADNI contributed. Many of the first applications of quantitative endophenotype association studies employed ADNI data, including some of the earliest GWAS and pathway-based studies of biospecimen and imaging biomarkers, as well as memory and other clinical/cognitive variables. Other contributions include some of the first WES and WGS data sets and reports in healthy controls, MCI, and AD. DISCUSSION Numerous genetic susceptibility and protective markers for AD and disease biomarkers have been identified and replicated using ADNI data, and have heavily implicated immune, mitochondrial, cell cycle/fate, and other biological processes. Early sequencing studies suggest that rare and structural variants are likely to account for significant additional phenotypic variation. Longitudinal analyses of transcriptomic, proteomic, metabolomic, and epigenomic changes will also further elucidate dynamic processes underlying preclinical and prodromal stages of disease. Integration of this unique collection of multi-omics data within a systems biology framework will help to separate truly informative markers of early disease mechanisms and potential novel therapeutic targets from the vast background of less relevant biological

  20. Heritability of personality: A meta-analysis of behavior genetic studies.

    PubMed

    Vukasović, Tena; Bratko, Denis

    2015-07-01

    The aim of this meta-analysis was to systematize available findings in the field of personality heritability and test for possible moderator effects of study design, type of personality model, and gender on heritability estimates. Study eligibility criteria were: personality model, behavior genetic study design, self-reported data, essential statistical indicators, and independent samples. A total of 134 primary studies with 190 potentially independent effect sizes were identified. After exclusion of studies that did not meet inclusion criteria and/or met 1 of the exclusion criteria, the final sample included 62 independent effect sizes, representing more than 100,000 participants of both genders and all ages. Data analyses were performed using the random-effects model, software program R package metafor. The average effect size was .40, indicating that 40% of individual differences in personality were due to genetic, while 60% are due to environmental influences. After correction for possible publication bias the conclusion was unaltered. Additional analyses showed that personality model and gender were not significant moderators of personality heritability estimate, while study design was a significant moderator with twin studies showing higher estimates, .47, compared to family and adoption studies, .22. Personality model also was not a significant moderator of heritability estimates for neuroticism or extraversion, 2 personality traits contained in most personality trait theories and/or models. This study is the first to empirically test and confirm moderator effect of study design on heritability estimates in the field of personality. Limitations of the study, as well as suggestion for future studies, are discussed. (PsycINFO Database Record PMID:25961374

  1. Contrasting genetic architectures in different mouse reference populations used for studying complex traits

    PubMed Central

    Buchner, David A.; Nadeau, Joseph H.

    2015-01-01

    Quantitative trait loci (QTLs) are being used to study genetic networks, protein functions, and systems properties that underlie phenotypic variation and disease risk in humans, model organisms, agricultural species, and natural populations. The challenges are many, beginning with the seemingly simple tasks of mapping QTLs and identifying their underlying genetic determinants. Various specialized resources have been developed to study complex traits in many model organisms. In the mouse, remarkably different pictures of genetic architectures are emerging. Chromosome Substitution Strains (CSSs) reveal many QTLs, large phenotypic effects, pervasive epistasis, and readily identified genetic variants. In contrast, other resources as well as genome-wide association studies (GWAS) in humans and other species reveal genetic architectures dominated with a relatively modest number of QTLs that have small individual and combined phenotypic effects. These contrasting architectures are the result of intrinsic differences in the study designs underlying different resources. The CSSs examine context-dependent phenotypic effects independently among individual genotypes, whereas with GWAS and other mouse resources, the average effect of each QTL is assessed among many individuals with heterogeneous genetic backgrounds. We argue that variation of genetic architectures among individuals is as important as population averages. Each of these important resources has particular merits and specific applications for these individual and population perspectives. Collectively, these resources together with high-throughput genotyping, sequencing and genetic engineering technologies, and information repositories highlight the power of the mouse for genetic, functional, and systems studies of complex traits and disease models. PMID:25953951

  2. Studies on Monitoring and Tracking Genetic Resources: An Executive Summary

    PubMed Central

    Garrity, George M.; Thompson, Lorraine M.; Ussery, David W.; Paskin, Norman; Baker, Dwight; Desmeth, Philippe; Schindel, D.E.; Ong, P.S.

    2009-01-01

    The principles underlying fair and equitable sharing of benefits derived from the utilization of genetic resources are set out in Article 15 of the UN Convention on Biological Diversity, which stipulate that access to genetic resources is subject to the prior informed consent of the country where such resources are located and to mutually agreed terms regarding the sharing of benefits that could be derived from such access. One issue of particular concern for provider countries is how to monitor and track genetic resources once they have left the provider country and enter into use in a variety of forms. This report was commissioned to provide a detailed review of advances in DNA sequencing technologies, as those methods apply to identification of genetic resources, and the use of globally unique persistent identifiers for persistently linking to data and other forms of digital documentation that is linked to individual genetic resources. While the report was written for an audience with a mixture of technical, legal, and policy backgrounds it is relevant to the genomics community as it is an example of downstream application of genomics information. PMID:21304641

  3. Identification of CSK as a systemic sclerosis genetic risk factor through Genome Wide Association Study follow-up

    PubMed Central

    Martin, Jose-Ezequiel; Broen, Jasper C.; Carmona, F. David; Teruel, Maria; Simeon, Carmen P.; Vonk, Madelon C.; van ‘t Slot, Ruben; Rodriguez-Rodriguez, Luis; Vicente, Esther; Fonollosa, Vicente; Ortego-Centeno, Norberto; González-Gay, Miguel A.; García-Hernández, Francisco J.; de la Peña, Paloma García; Carreira, Patricia; Voskuyl, Alexandre E.; Schuerwegh, Annemie J.; van Riel, Piet L.C.M.; Kreuter, Alexander; Witte, Torsten; Riemekasten, Gabriella; Airo, Paolo; Scorza, Raffaella; Lunardi, Claudio; Hunzelmann, Nicolas; Distler, Jörg H.W.; Beretta, Lorenzo; van Laar, Jacob; Chee, Meng May; Worthington, Jane; Herrick, Ariane; Denton, Christopher; Tan, Filemon K.; Arnett, Frank C.; Assassi, Shervin; Fonseca, Carmen; Mayes, Maureen D.; Radstake, Timothy R.D.J.; Koeleman, Bobby P.C.; Martin, Javier

    2012-01-01

    Systemic sclerosis (SSc) is complex autoimmune disease affecting the connective tissue; influenced by genetic and environmental components. Recently, we performed the first successful genome-wide association study (GWAS) of SSc. Here, we perform a large replication study to better dissect the genetic component of SSc. We selected 768 polymorphisms from the previous GWAS and genotyped them in seven replication cohorts from Europe. Overall significance was calculated for replicated significant SNPs by meta-analysis of the replication cohorts and replication-GWAS cohorts (3237 cases and 6097 controls). Six SNPs in regions not previously associated with SSc were selected for validation in another five independent cohorts, up to a total of 5270 SSc patients and 8326 controls. We found evidence for replication and overall genome-wide significance for one novel SSc genetic risk locus: CSK [P-value = 5.04 × 10−12, odds ratio (OR) = 1.20]. Additionally, we found suggestive association in the loci PSD3 (P-value = 3.18 × 10−7, OR = 1.36) and NFKB1 (P-value = 1.03 × 10−6, OR = 1.14). Additionally, we strengthened the evidence for previously confirmed associations. This study significantly increases the number of known putative genetic risk factors for SSc, including the genes CSK, PSD3 and NFKB1, and further confirms six previously described ones. PMID:22407130

  4. 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

  5. Bulimia nervosa and major depression: a study of common genetic and environmental factors.

    PubMed

    Walters, E E; Neale, M C; Eaves, L J; Heath, A C; Kessler, R C; Kendler, K S

    1992-08-01

    A genetic analysis of the co-occurrence of bulimia and major depression (MD) was performed on 1033 female twin pairs obtained from a population based register. Personal interviews were conducted and clinical diagnoses made according to DSM-III-R criteria. Additive genes, but not family environment, are found to play an important aetiological role in both bulimia and MD. The genetic liabilities of the two disorders are correlated 0.456. While unique environmental factors account for around half of the variation in liability to both bulimia and MD, these risk factors appear to be unrelated, i.e., each disorder has its own set of unique environmental risk factors. Thus, the genetic liability of bulimia and MD is neither highly specific nor entirely non-specific. There is some genetic correlation between the two disorders as well as some genetic and environmental risk factors unique to each disorder. Limitations and directions for future research are discussed. PMID:1410087

  6. A twin and molecular genetics study of sleep paralysis and associated factors.

    PubMed

    Denis, Dan; French, Christopher C; Rowe, Richard; Zavos, Helena M S; Nolan, Patrick M; Parsons, Michael J; Gregory, Alice M

    2015-08-01

    Sleep paralysis is a relatively common but under-researched phenomenon. In this paper we examine prevalence in a UK sample and associations with candidate risk factors. This is the first study to investigate the heritability of sleep paralysis in a twin sample and to explore genetic associations between sleep paralysis and a number of circadian expressed single nucleotide polymorphisms. Analyses are based on data from the Genesis1219 twin/sibling study, a community sample of twins/siblings from England and Wales. In total, data from 862 participants aged 22-32 years (34% male) were used in the study. This sample consisted of monozygotic and dizygotic twins and siblings. It was found that self-reports of general sleep quality, anxiety symptoms and exposure to threatening events were all associated independently with sleep paralysis. There was moderate genetic influence on sleep paralysis (53%). Polymorphisms in the PER2 gene were associated with sleep paralysis in additive and dominant models of inheritance-although significance was not reached once a Bonferroni correction was applied. It is concluded that factors associated with disrupted sleep cycles appear to be associated with sleep paralysis. In this sample of young adults, sleep paralysis was moderately heritable. Future work should examine specific polymorphisms associated with differences in circadian rhythms and sleep homeostasis further in association with sleep paralysis. PMID:25659590

  7. Frontiers of torenia research: innovative ornamental traits and study of ecological interaction networks through genetic engineering

    PubMed Central

    2013-01-01

    Advances in research in the past few years on the ornamental plant torenia (Torenia spps.) have made it notable as a model plant on the frontier of genetic engineering aimed at studying ornamental characteristics and pest control in horticultural ecosystems. The remarkable advantage of torenia over other ornamental plant species is the availability of an easy and high-efficiency transformation system for it. Unfortunately, most of the current torenia research is still not very widespread, because this species has not become prominent as an alternative to other successful model plants such as Arabidopsis, snapdragon and petunia. However, nowadays, a more global view using not only a few selected models but also several additional species are required for creating innovative ornamental traits and studying horticultural ecosystems. We therefore introduce and discuss recent research on torenia, the family Scrophulariaceae, for secondary metabolite bioengineering, in which global insights into horticulture, agriculture and ecology have been advanced. Floral traits, in torenia particularly floral color, have been extensively studied by manipulating the flavonoid biosynthetic pathways in flower organs. Plant aroma, including volatile terpenoids, has also been genetically modulated in order to understand the complicated nature of multi-trophic interactions that affect the behavior of predators and pollinators in the ecosystem. Torenia would accordingly be of great use for investigating both the variation in ornamental plants and the infochemical-mediated interactions with arthropods. PMID:23803155

  8. Generating Scenarios of Addition and Subtraction: A Study of Japanese University Students

    ERIC Educational Resources Information Center

    Kinda, Shigehiro

    2013-01-01

    Students are presented with problems involving three scenario types of addition and subtraction in elementary mathematics: one dynamic ("Change") and two static ("Combine, Compare"). Previous studies have indicated that the dynamic type is easier for school children, whereas the static types are more difficult and comprehended only gradually…

  9. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Engineering and cost studies-addition of generation capacity. 1710.253 Section 1710.253 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND...

  10. 7 CFR 1710.253 - Engineering and cost studies-addition of generation capacity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 11 2012-01-01 2012-01-01 false Engineering and cost studies-addition of generation capacity. 1710.253 Section 1710.253 Agriculture Regulations of the Department of Agriculture (Continued) RURAL UTILITIES SERVICE, DEPARTMENT OF AGRICULTURE GENERAL AND PRE-LOAN POLICIES AND PROCEDURES COMMON TO ELECTRIC LOANS AND...

  11. Experimental study of combustion of decane, dodecane and hexadecane with polymeric and nano-particle additives

    NASA Astrophysics Data System (ADS)

    Ghamari, Mohsen; Ratner, Albert

    2015-11-01

    Recent studies have shown that adding combustible nano-particles could have promising effects on increasing burning rate of liquid fuels. Combustible nano-particles could enhance the heat conduction and mixing within the droplet. Polymers have also higher burning rate than regular hydrocarbon fuels because of having the flame closer to the droplet surface. Therefore adding polymeric additive could have the potential to increase the burning rate. In this study, combustion of stationary fuel droplets of n-Decane, n-Dodecane and n-Hexadecane doped with different percentages of a long chain polymer and also a very fine nano carbon was examined and compared with the pure hydrocarbon behavior. In contrast with hydrocarbon droplets with no polymer addition, several zones of combustion including a slow and steady burning zone, a strong swelling zone and a final fast and fairly steady combustion zone were also detected. In addition, increasing polymer percentage resulted in a more extended swelling zone and shorter slow burning zone in addition to a shorter total burning time. Addition of nano-particles also resulted in an overall increased burning rate and shortened burning time which is due to enhanced heat conduction within the droplet.

  12. Use of Longitudinal Data in Genetic Studies in the Genome-wide Association Studies Era: Summary of Group 14

    PubMed Central

    Kerner, Berit; North, Kari E; Fallin, M Daniele

    2010-01-01

    Participants analyzed actual and simulated longitudinal data from the Framingham Heart Study for various metabolic and cardiovascular traits. The genetic information incorporated into these investigations ranged from selected single-nucleotide polymorphisms to genome-wide association arrays. Genotypes were incorporated using a broad range of methodological approaches including conditional logistic regression, linear mixed models, generalized estimating equations, linear growth curve estimation, growth modeling, growth mixture modeling, population attributable risk fraction based on survival functions under the proportional hazards models, and multivariate adaptive splines for the analysis of longitudinal data. The specific scientific questions addressed by these different approaches also varied, ranging from a more precise definition of the phenotype, bias reduction in control selection, estimation of effect sizes and genotype associated risk, to direct incorporation of genetic data into longitudinal modeling approaches and the exploration of population heterogeneity with regard to longitudinal trajectories. The group reached several overall conclusions: 1) The additional information provided by longitudinal data may be useful in genetic analyses. 2) The precision of the phenotype definition as well as control selection in nested designs may be improved, especially if traits demonstrate a trend over time or have strong age-of-onset effects. 3) Analyzing genetic data stratified for high-risk subgroups defined by a unique development over time could be useful for the detection of rare mutations in common multi-factorial diseases. 4) Estimation of the population impact of genomic risk variants could be more precise. The challenges and computational complexity demanded by genome-wide single-nucleotide polymorphism data were also discussed. PMID:19924713

  13. Use of longitudinal data in genetic studies in the genome-wide association studies era: summary of Group 14.

    PubMed

    Kerner, Berit; North, Kari E; Fallin, M Daniele

    2009-01-01

    Participants analyzed actual and simulated longitudinal data from the Framingham Heart Study for various metabolic and cardiovascular traits. The genetic information incorporated into these investigations ranged from selected single-nucleotide polymorphisms to genome-wide association arrays. Genotypes were incorporated using a broad range of methodological approaches including conditional logistic regression, linear mixed models, generalized estimating equations, linear growth curve estimation, growth modeling, growth mixture modeling, population attributable risk fraction based on survival functions under the proportional hazards models, and multivariate adaptive splines for the analysis of longitudinal data. The specific scientific questions addressed by these different approaches also varied, ranging from a more precise definition of the phenotype, bias reduction in control selection, estimation of effect sizes and genotype associated risk, to direct incorporation of genetic data into longitudinal modeling approaches and the exploration of population heterogeneity with regard to longitudinal trajectories. The group reached several overall conclusions: (1) The additional information provided by longitudinal data may be useful in genetic analyses. (2) The precision of the phenotype definition as well as control selection in nested designs may be improved, especially if traits demonstrate a trend over time or have strong age-of-onset effects. (3) Analyzing genetic data stratified for high-risk subgroups defined by a unique development over time could be useful for the detection of rare mutations in common multifactorial diseases. (4) Estimation of the population impact of genomic risk variants could be more precise. The challenges and computational complexity demanded by genome-wide single-nucleotide polymorphism data were also discussed. PMID:19924713

  14. Genetic and environmental influences on spontaneous micronuclei frequencies in children and adults: a twin study.

    PubMed

    Jones, Kimberly H; York, Timothy P; Juusola, Jane; Ferreira-Gonzalez, Andrea; Maes, Hermine H; Jackson-Cook, Colleen

    2011-11-01

    The primary aim of this study was to quantify genetic and environmental influences on the frequency of spontaneously occurring micronuclei in children and adults. To meet this aim, a total of 63 male and female twin pairs and 19 singletons (145 individuals) were evaluated, ranging in age from 7 to 85 years. Micronuclei frequencies significantly increased with age for both genders (r = 0.49, P < 0.001), with the lowest and highest rates being seen in the 7- to 9 (mean = 0.56%, SD = .28) and 60- to 69-year-olds (mean = 2.12%, SD = 1.0), respectively. This age effect was significantly more pronounced in females than males (P = 0.017). In addition to the main effect of age, the completion of puberty in either gender (P = 0.036) and menopause in females (P = 0.024) was associated with a significant increase in micronuclei frequencies. Genetic model fitting indicated that influences from both additive genetic (65.2% of variance) and unique environmental (34.8% of variance) sources best explained the observed micronuclei frequencies in monozygotic and dizygotic twin pairs. Self-reported health conditions associated with an increased frequency of micronuclei included a history of allergies (P < 0.007) and migraines (P = 0.026). Multivitamin use was also associated with increased micronuclei frequencies (P = 0.004). In contrast, significantly lower micronuclei frequencies were associated with arthritis (P = 0.002), as well as consuming fruit (P = 0.014), green, leafy vegetables (P < 0.001) and/or folate-enriched bread (P = 0.035). A sex-specific effect, resulting in a significantly increased frequency of micronuclei with tobacco usage, was observed for females (but not males). Gender differences also moderated the impact of vitamin D and calcium consumption. In conclusion, the frequency of spontaneously arising micronuclei in humans is a complex trait, being influenced by both heritable genetic and environmental components. Recognition of factors contributing to baseline

  15. Genes, Demography, and Life Span: The Contribution of Demographic Data in Genetic Studies on Aging and Longevity

    PubMed Central

    Yashin, A. I.; De Benedictis, G.; Vaupel, J. W.; Tan, Q.; Andreev, K. F.; Iachine, I. A.; Bonafe, M.; DeLuca, M.; Valensin, S.; Carotenuto, L.; Franceschi, C.

    1999-01-01

    Summary In population studies on aging, the data on genetic markers are often collected for individuals from different age groups. The purpose of such studies is to identify, by comparison of the frequencies of selected genotypes, “longevity” or “frailty” genes in the oldest and in younger groups of individuals. To address questions about more-complicated aspects of genetic influence on longevity, additional information must be used. In this article, we show that the use of demographic information, together with data on genetic markers, allows us to calculate hazard rates, relative risks, and survival functions for respective genes or genotypes. New methods of combining genetic and demographic information are discussed. These methods are tested on simulated data and then are applied to the analysis of data on genetic markers for two haplogroups of human mtDNA. The approaches suggested in this article provide a powerful tool for analyzing the influence of candidate genes on longevity and survival. We also show how factors such as changes in the initial frequencies of candidate genes in subsequent cohorts, or secular trends in cohort mortality, may influence the results of an analysis. PMID:10486337

  16. Genetic susceptibility to Barrett’s oesophagus: Lessons from early studies

    PubMed Central

    Middleton, Mark R; Tomlinson, Ian

    2015-01-01

    Barrett’s oesophagus (BO) is a common condition, predisposing strongly to the development of oesophageal adenocarcinoma (OAC). Consequently, there has been considerable effort to determine the processes involved in the development of BO metaplasia, and ultimately develop markers of patients at risk. Whilst a number of robust acquired risk factors have been identified, a genetic component to these and the apparent increased susceptibility of certain individuals has long been suspected. This has been evidenced in part by linkage studies, but subsequently two recent genome-wide association studies (GWAS) have suggested mechanisms underlying the heritability of BO, as well as providing the first direct evidence at modern levels of statistical significance. This review discusses BO heritability, in addition to that of individual variants and genes reported to be associated with BO to date. Through this, we identify a number of plausible associations, although often tempered by issues of methodology, and discuss the priorities and need for future research. PMID:27536357

  17. Informed consent, participation in, and withdrawal from a population based cohort study involving genetic analysis

    PubMed Central

    Matsui, K; Kita, Y; Ueshima, H

    2005-01-01

    Design: Descriptive analyses. Setting and participants: The study evaluated two non-genetic subcohorts comprising 3166 people attending for a health checkup during 2002, and two genetic subcohorts comprising 2195 people who underwent a checkup during 2003. Main outcome measurements: Analysis endpoints were differences in participation rates between the non-genetic and genetic subcohorts, differences between providing non-extensive and extensive preliminary information, and changes in participation status between baseline and at 6 months. Results: Participation rates in the genetic subcohorts were 4·7–9·3% lower than those in the non-genetic subcohorts. The odds ratios (OR) of participation in genetic research were between 0·60 and 0·77, and the OR for withdrawal from the research was over 7·70; providing preliminary extensive information about genetic research reduced the withdrawal risks (OR 0·15 for all dependent variables) but worsened participation rates (OR 0·63–0·74). Conclusions: The general population responded sceptically towards genetic research. It is crucial that genetic researchers utilise an informative and educational consent process worthy of public trust. PMID:15994356

  18. Anatomically ordered tapping interferes more with one-digit addition than two-digit addition: a dual-task fMRI study.

    PubMed

    Soylu, Firat; Newman, Sharlene D

    2016-02-01

    Fingers are used as canonical representations for numbers across cultures. In previous imaging studies, it was shown that arithmetic processing activates neural resources that are known to participate in finger movements. Additionally, in one dual-task study, it was shown that anatomically ordered finger tapping disrupts addition and subtraction more than multiplication, possibly due to a long-lasting effect of early finger counting experiences on the neural correlates and organization of addition and subtraction processes. How arithmetic task difficulty and tapping complexity affect the concurrent performance is still unclear. If early finger counting experiences have bearing on the neural correlates of arithmetic in adults, then one would expect anatomically and non-anatomically ordered tapping to have different interference effects, given that finger counting is usually anatomically ordered. To unravel these issues, we studied how (1) arithmetic task difficulty and (2) the complexity of the finger tapping sequence (anatomical vs. non-anatomical ordering) affect concurrent performance and use of key neural circuits using a mixed block/event-related dual-task fMRI design with adult participants. The results suggest that complexity of the tapping sequence modulates interference on addition, and that one-digit addition (fact retrieval), compared to two-digit addition (calculation), is more affected from anatomically ordered tapping. The region-of-interest analysis showed higher left angular gyrus BOLD response for one-digit compared to two-digit addition, and in no-tapping conditions than dual tapping conditions. The results support a specific association between addition fact retrieval and anatomically ordered finger movements in adults, possibly due to finger counting strategies that deploy anatomically ordered finger movements early in the development. PMID:26410214

  19. Genetic Simulation Tools for Post-Genome Wide Association Studies of Complex Diseases

    PubMed Central

    Amos, Christopher I.; Bafna, Vineet; Hauser, Elizabeth R.; Hernandez, Ryan D.; Li, Chun; Liberles, David A.; McAllister, Kimberly; Moore, Jason H.; Paltoo, Dina N.; Papanicolaou, George J.; Peng, Bo; Ritchie, Marylyn D.; Rosenfeld, Gabriel; Witte, John S.

    2014-01-01

    Genetic simulation programs are used to model data under specified assumptions to facilitate the understanding and study of complex genetic systems. Standardized data sets generated using genetic simulation are essential for the development and application of novel analytical tools in genetic epidemiology studies. With continuing advances in high-throughput genomic technologies and generation and analysis of larger, more complex data sets, there is a need for updating current approaches in genetic simulation modeling. To provide a forum to address current and emerging challenges in this area, the National Cancer Institute (NCI) sponsored a workshop, entitled “Genetic Simulation Tools for Post-Genome Wide Association Studies of Complex Diseases” at the National Institutes of Health (NIH) in Bethesda, Maryland on March 11-12, 2014. The goals of the workshop were to: (i) identify opportunities, challenges and resource needs for the development and application of genetic simulation models; (ii) improve the integration of tools for modeling and analysis of simulated data; and (iii) foster collaborations to facilitate development and applications of genetic simulation. During the course of the meeting the group identified challenges and opportunities for the science of simulation, software and methods development, and collaboration. This paper summarizes key discussions at the meeting, and highlights important challenges and opportunities to advance the field of genetic simulation. PMID:25371374

  20. A biochemical and genetic study of Leishmania donovani pyruvate kinase.

    PubMed

    Sandoval, Will; Isea, Raúl; Rodriguez, Evelyn; Ramirez, Jose Luis

    2008-11-15

    Here we present a biochemical and molecular biology study of the enzyme pyruvate kinase (PYK) from the parasitic protozoa Leishmania donovani. The PYK gene was cloned, mutagenised and over expressed and its kinetic parameters determined. Like in other kinetoplastids, L. donovani PYK is allosterically stimulated by the effector fructose 2,6 biphosphate and not by fructose 1,6 biphosphate. When the putative effector binding site of L. donovani PYK was mutagenised, we obtained two mutants with extreme kinetic behavior: Lys453Leu, which retained a sigmoidal kinetics and was little affected by the effector; and His480Gln, which deployed a hyperbolic kinetics that was not changed by the addition of the effector. Molecular Dynamics (MD) studies revealed that the mutations not only altered the effector binding site of L. donovani PYK but also changed the folding of its domain C. PMID:18725273

  1. Genetic Influences on Alcohol Use Behaviors Have Diverging Developmental Trajectories: A Prospective Study among Male and Female Twins

    PubMed Central

    Meyers, Jacquelyn L.; Salvatore, Jessica E.; Vuoksimaa, Eero; Korhonen, Tellervo; Pulkkinen, Lea; Rose, Richard J.; Kaprio, Jaakko; Dick, Danielle M.

    2014-01-01

    Background Both alcohol-specific genetic factors and genetic factors related to externalizing behavior influence problematic alcohol use. Little is known, however, about the etiologic role of these two components of genetic risk on alcohol-related behaviors across development. Prior studies conducted in a male cohort of twins suggest that externalizing genetic factors are important for predicting heavy alcohol use in adolescence, whereas alcohol-specific genetic factors increase in importance during the transition to adulthood. In this report, we studied twin brothers and sisters and brother-sister twin pairs to examine such developmental trajectories and investigate whether sex and co-twin sex effects modify these genetic influences. Methods We used prospective, longitudinal twin data collected between ages 12 and 22 within the population-based FinnTwin12 cohort study (analytic n=1,864). Our dependent measures of alcohol use behaviors included alcohol initiation (age 12), intoxication frequency (ages 14 and 17), and alcohol dependence criteria (age 22). Each individual’s genetic risk for alcohol use disorders (AUD-GR) was indexed by his/her parents’ and co-twin’s DSM-IV Alcohol Dependence (AD) criterion counts. Likewise, each individual’s genetic risk for externalizing disorders (EXT-GR) was indexed with a composite measure of parents’ and co-twin’s DSM-IV Conduct Disorder and Antisocial Personality Disorder criterion counts. Results EXT-GR was most strongly related to alcohol use behaviors during adolescence while AUD-GR was most strongly related to alcohol problems in young adulthood. Further, sex of the twin and sex of the co-twin significantly moderated the associations between genetic risk and alcohol use behaviors across development: AUD-GR influenced early adolescent alcohol use behaviors in females more than in males, and EXT-GR influenced age 22 AD more in males than in females. In addition, the associations of AUD-GR and EXT-GR with

  2. What Can the Study of Genetics Offer to Educators?

    ERIC Educational Resources Information Center

    Thomas, Michael S. C.; Kovas, Yulia; Meaburn, Emma L.; Tolmie, Andrew

    2015-01-01

    This article explores the potential contribution of modern genetic methods and findings to education. It is familiar to hear that the "gene" for this or that behavior has been discovered, or that certain skills are "highly heritable." Can this help educators? To explore this question, we describe the methods used to relate…

  3. Genetic and Environmental Etiologies of Reading Disability: A Twin Study.

    ERIC Educational Resources Information Center

    LaBuda, Michele C.; DeFries, J. C.

    1988-01-01

    Data analysis of 134 twin pairs from the Colorado Reading Project found that approximately 40 percent of the deficit observed in disabled readers is because of genetic factors, 35 percent because of environmental influences shared by twin pairs, and 25 percent because of environmental factors unique to the individual and/or error variance.…

  4. Genetic Effects on Human Behavior: Recent Family Studies.

    ERIC Educational Resources Information Center

    Scarr, Sandra

    Although there continues to be controversy about the magnitude of genetic and environmental effects on human behavior, it is generally agreed by various scientific fields that individual differences in brain function and behavior must follow the same laws of variability as other human characteristics. Whether or not racial and ethnic group…

  5. Obesity, hypertension and genetic variation in the TIGER Study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Obesity and hypertension are multifactoral conditions in which the onset and severity of the conditions are influenced by the interplay of genetic and environmental factors. We hypothesize that multiple genes and environmental factors account for a significant amount of variation in BMI and blood pr...

  6. Ninos Desaparecidos: A Case Study about Genetics and Human Rights.

    ERIC Educational Resources Information Center

    Chamany, Katayoun

    2001-01-01

    Provides information on the experiences of 50 children displaced during Argentina's "dirty war" of the 1970s who underwent DNA and protein analysis and subsequently were reunited with their biological families. Considers not only genetic evidence but the moral, political, and emotional dimensions of these children's stories as well. (Contains 19…

  7. Genetic determinants of bone mass in adults. A twin study.

    PubMed Central

    Pocock, N A; Eisman, J A; Hopper, J L; Yeates, M G; Sambrook, P N; Eberl, S

    1987-01-01

    The relative importance of genetic factors in determining bone mass in different parts of the skeleton is poorly understood. Lumbar spine and proximal femur bone mineral density and forearm bone mineral content were measured by photon absorptiometry in 38 monozygotic and 27 dizygotic twin pairs. Bone mineral density was significantly more highly correlated in monozygotic than in dizygotic twins for the spine and proximal femur and in the forearm of premenopausal twin pairs, which is consistent with significant genetic contributions to bone mass at all these sites. The lesser genetic contribution to proximal femur and distal forearm bone mass compared with the spine suggests that environmental factors are of greater importance in the aetiology of osteopenia of the hip and wrist. This is the first demonstration of a genetic contribution to bone mass of the spine and proximal femur in adults and confirms similar findings of the forearm. Furthermore, bivariate analysis suggested that a single gene or set of genes determines bone mass at all sites. PMID:3624485

  8. Genetic Studies of Stuttering in a Founder Population

    ERIC Educational Resources Information Center

    Wittke-Thompson, Jacqueline K.; Ambrose, Nicoline; Yairi, Ehud; Roe, Cheryl; Cook, Edwin H.; Ober, Carole; Cox, Nancy J.

    2007-01-01

    Genome-wide linkage and association analyses were conducted to identify genetic determinants of stuttering in a founder population in which 48 individuals affected with stuttering are connected in a single 232-person genealogy. A novel approach was devised to account for all necessary relationships to enable multipoint linkage analysis. Regions…

  9. Genetic studies of neuropsychiatric disorders in Costa Rica: a model for the use of isolated populations.

    PubMed

    Mathews, Carol A; Reus, Victor I; Bejarano, Julio; Escamilla, Michael A; Fournier, Eduardo; Herrera, Luis Diego; Lowe, Thomas L; McInnes, L Alison; Molina, Julio; Ophoff, Roel A; Raventos, Henrietta; Sandkuijl, Lodewijk A; Service, Susan K; Spesny, Mitzi; León, Pedro E; Freimer, Nelson B

    2004-03-01

    The importance of genetics in understanding the etiology of mental illness has become increasingly clear in recent years, as more evidence has mounted that almost all neuropsychiatric disorders have a genetic component. It has also become clear, however, that these disorders are etiologically complex, and multiple genetic and environmental factors contribute to their makeup. So far, traditional linkage mapping studies have not definitively identified specific disease genes for neuropsychiatric disorders, although some potential candidates have been identified via these methods (e.g. the dysbindin gene in schizophrenia; Straub et al., 2002; Schwab et al., 2003). For this reason, alternative approaches are being attempted, including studies in genetically isolated populations. Because isolated populations have a high degree of genetic homogeneity, their use may simplify the process of identifying disease genes in disorders where multiple genes may play a role. Several areas of Latin America contain genetically isolated populations that are well suited for the study of neuropsychiatric disorders. Genetic studies of several major psychiatric illnesses, including bipolar disorder, major depression, schizophrenia, Tourette Syndrome, alcohol dependence, attention deficit hyperactivity disorder, and obsessive-compulsive disorder, are currently underway in these regions. In this paper we highlight the studies currently being conducted by our groups in the Central Valley of Costa Rica to illustrate the potential advantages of this population for genetic studies. PMID:15091311

  10. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    NASA Astrophysics Data System (ADS)

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-01

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. The observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.

  11. Microstructural Study Of Zinc Hot Dip Galvanized Coatings with Titanium Additions In The Zinc Melt

    NASA Astrophysics Data System (ADS)

    Konidaris, S.; Pistofidis, N.; Vourlias, G.; Pavlidou, E.; Stergiou, A.; Stergioudis, G.; Polychroniadis, E. K.

    2007-04-01

    Zinc hot-dip galvanizing is a method for protecting iron and steel against corrosion. Galvanizing with pure Zn or Zn with additions like Ni, Al, Pb and Bi has been extensively studied, but there is a lack of scientific information about other additions. The present work examines the effect of a 0.5 wt% Ti addition in the Zn melt. The samples were exposed to accelerated corrosion in a salt spray chamber (SSC). The microstructure and chemical composition of the coatings were determined by Optical Microscopy, XRD and SEM associated with an EDS Analyzer. The results indicate that the coatings have a typical morphology, while Zn-Ti phases were also detected.

  12. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    PubMed Central

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-01-01

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. The observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys. PMID:26446425

  13. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    SciTech Connect

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused by a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.

  14. Strategies for genetic study of hearing loss in the Brazilian northeastern region

    PubMed Central

    Melo, Uirá S; Santos, Silvana; Cavalcanti, Hannalice G; Andrade, Wagner T; Dantas, Vitor G; Rosa, Marine RD; Mingroni-Netto, Regina C

    2014-01-01

    The overall aim of this study was to estimate the contribution of genetic factors to the etiology of hearing loss (HL) in two counties in the Brazilian northeastern region. A cross-sectional study, based on the key informant approach (KI) was conducted in Queimadas and Gado Bravo counties (Paraíba, Northeast Brazil). The sample consisted of 182 patients with HL. Genetic screening of the most frequent mutations associated with HL was performed for all samples. DFNB1 mutations were the most frequently found in both counties. The c.35delG mutation was detected in homozygosis in seven non-syndromic probands in Queimadas (7/76, 9.2%) and only a single homozygote with this mutation was found in Gado Bravo (1/44, 2.3%). We also detected the del(GJB6-D13S1854) mutation in non-syndromic probands from Gado Bravo (2/44, 4.5%). The c.189C>A (p.TyrY63*) mutation in the CLRN1 gene was detected in homozygosis in 21/23 Usher syndrome patients from Gado Bravo and it was not found in Queimadas. Cases with probable genetic etiology contributed approximately to half of HL probands in each county (54.6% in Gado Bravo and 45.7% in Queimadas). We confirm the importance of DFNB1 locus to non-syndromic HL but we show that the frequency of mutations in the northeastern region differs somewhat from those reported in southeastern Brazil and other populations. In addition, the extremely high frequency of individuals with Usher syndrome with c.189C>A variation in CLRN1 indicates the need for a specific screening of this mutation. PMID:24596593

  15. Summary of Previous Chamber or Controlled Anthrax Studies and Recommendations for Possible Additional Studies

    SciTech Connect

    Piepel, Gregory F.; Amidan, Brett G.; Morrow, Jayne B.

    2010-12-29

    This report and an associated Excel file(a) summarizes the investigations and results of previous chamber and controlled studies(b) to characterize the performance of methods for collecting, storing and/or transporting, extracting, and analyzing samples from surfaces contaminated by Bacillus anthracis (BA) or related simulants. This report and the Excel are the joint work of the Pacific Northwest National Laboratory (PNNL) and the National Institute of Standards and Technology (NIST) for the Department of Homeland Security, Science and Technology Directorate. The report was originally released as PNNL-SA-69338, Rev. 0 in November 2009 with limited distribution, but was subsequently cleared for release with unlimited distribution in this Rev. 1. Only minor changes were made to Rev. 0 to yield Rev. 1. A more substantial update (including summarizing data from other studies and more condensed summary tables of data) is underway

  16. Genetic approaches for studying myiasis-causing flies: molecular markers and mitochondrial genomics.

    PubMed

    de Azeredo-Espin, Ana Maria Lima; Lessinger, Ana Cláudia

    2006-01-01

    "Myiasis-causing flies" is a generic term that includes species from numerous dipteran families, mainly Calliphoridae and Oestridae, of which blowflies, screwworm flies and botflies are among the most important. This group of flies is characterized by the ability of their larvae to develop in animal flesh. When the host is a live vertebrate, such parasitism by dipterous larvae is known as primary myiasis. Myiasis-causing flies can be classified as saprophagous (free-living species), facultative or obligate parasites. Many of these flies are of great medical and veterinary importance in Brazil because of their role as key livestock insect-pests and vectors of pathogens, in addition to being considered important legal evidence in forensic entomology. The characterization of myiasis-causing flies using molecular markers to study mtDNA (by RFLP) and nuclear DNA (by RAPD and microsatellite) has been used to identify the evolutionary mechanisms responsible for specific patterns of genetic variability. These approaches have been successfully used to analyze the population structures of the New World screwworm fly Cochliomyia hominivorax and the botfly Dermatobia hominis. In this review, various aspects of the organization, evolution and potential applications of the mitochondrial genome of myiasis-causing flies in Brazil, and the analysis of nuclear markers in genetic studies of populations, are discussed. PMID:16502089

  17. Genetic and environmental risk factors for asthma: a cotwin-control study.

    PubMed

    Duffy, D L; Mitchell, C A; Martin, N G

    1998-03-01

    In complex diseases of genetic etiology such as asthma and atopy, it is difficult to differentiate causes of disease from consequences, and quantitate the importance of such causative factors. We examined possible risk factors for the development of wheezing and bronchial hyperresponsiveness in a cotwin-control study nested within a larger community-based twin-family study. In 62 monozygotic (MZ) twin pairs discordant for a history of wheezing, skin prick test to house dust extract was the most important discriminator, followed by sensitization to cat and cockroach allergens. In contrast, 62 dizygotic (DZ) discordant twin pairs differed additionally in sensitization to grass pollens and fungi. Markers such as serum haptoglobin, serum magnesium, and alpha-1-antitrypsin levels did not differ significantly between discordant twins. This MZ/DZ difference suggests that pollen allergy in asthmatics is more an epiphenomenon due to a genetic correlation between asthma and the allergic diathesis, whereas indoor allergens are likely to be direct environmental causes of asthma. PMID:9517600

  18. Genetic linkage studies in autosomal recessive retinitis pigmentosa

    SciTech Connect

    Mansfield, D.C.; Teague, P.W.; Barber, A.

    1994-09-01

    Autosomal recessive retinitis pigmentosa (arRP) is a severe retinal dystrophy characterized by night blindness, progressive constriction of the visual fields and loss of central vision in the fourth or fifth decades. The frequency of this form of retinitis pigmentosa (RP) varies in different populations. Mutations within the rhodopsin, cyclic GMP phosphodiesterase-{beta} subunit and cGMP-gated channel genes have been reported in some arRP families. The genetic loci responsible for the majority of cases have yet to be identified. Genetic heterogeneity is likely to be extensive. In order to minimize the amount of genetic heterogenity, a set of arRP families was ascertained within the South-Central Sardinian population, in which 81% of families with a known mode of inheritance show an autosomal recessive form of RP. The Sardinian population is an ethnic {open_quotes}outlier{close_quotes}, having remained relatively isolated from mainland and other cultures. Genetic linkage data has been obtained in a set of 11 Sardinian arRP kindreds containing 26 affected members. Under the assumption of genetic homogeneity, no evidence of linkage was found in the arRP kindreds using 195 markers, which excluded 62% of the genome (Z<-2). Positive lod scores were obtained with D14S80 which showed no recombination in a subset of 5 families. Heterogeneity testing using D14S80 and arRP showed no significant evidence of heterogeneity (p=0.18) but evidence of linkage ({chi}{sup 2}=3.64, p=0.028). We are currently screening the neural retina-specific leucine zipper gene (NRL) in 14q11 for mutations as a candidate locus.

  19. Studies of levels of biogenic amines in meat samples in relation to the content of additives.

    PubMed

    Jastrzębska, Aneta; Kowalska, Sylwia; Szłyk, Edward

    2016-01-01

    The impact of meat additives on the concentration of biogenic amines and the quality of meat was studied. Fresh white and red meat samples were fortified with the following food additives: citric and lactic acids, disodium diphosphate, sodium nitrite, sodium metabisulphite, potassium sorbate, sodium chloride, ascorbic acid, α-tocopherol, propyl 3,4,5-trihydroxybenzoate (propyl gallate) and butylated hydroxyanisole. The content of spermine, spermidine, putrescine, cadaverine, histamine, tyramine, tryptamine and 2-phenylethylamine was determined by capillary isotachophoretic methods in meat samples (fresh and fortified) during four days of storage at 4°C. The results were applied to estimate the impact of the tested additives on the formation of biogenic amines in white and red meat. For all tested meats, sodium nitrite, sodium chloride and disodium diphosphate showed the best inhibition. However, cadaverine and putrescine were characterised by the biggest changes in concentration during the storage time of all the additives. Based on the presented data for the content of biogenic amines in meat samples analysed as a function of storage time and additives, we suggest that cadaverine and putrescine have a significant impact on meat quality. PMID:26515667

  20. Disclosure of research results in genetic studies of Parkinson's disease caused by LRRK2 mutations.

    PubMed

    Pont-Sunyer, Claustre; Bressman, Susan; Raymond, Deborah; Glickman, Amanda; Tolosa, Eduardo; Saunders-Pullman, Rachel

    2015-06-01

    With the advent of large genetic studies examining both symptomatic and asymptomatic individuals, whether and how to disclose genetic research results have become pressing questions. The need is particularly acute in the case of LRRK2 research: Movement centers worldwide are recruiting cohorts of individuals with Parkinson's disease (PD) and their family members, including asymptomatic carriers. Clinical features and treatment are complex and evolving, and disclosure policies vary at different sites and have been modified during the course of some studies. We present the major ethical principles of autonomy, beneficence, nonmaleficence, and honesty that should guide disclosure policies in studies of families with LRRK2 mutations. We make recommendations regarding genetic counseling, policies of either active or passive disclosure, responsibilities of funders to budget for genetic counseling, clinical genetic testing where locally required for disclosure, and aspects of study design to avoid mandatory disclosure whenever feasible. © 2015 International Parkinson and Movement Disorder Society. PMID:25952684

  1. Disclosure of Research Results in Genetic Studies of Parkinson Disease Due to LRRK2 Mutations

    PubMed Central

    Bressman, Susan; Raymond, Deborah; Glickman, Amanda; Tolosa, Eduardo

    2015-01-01

    With the advent of large genetic studies examining both symptomatic and asymptomatic individuals, whether and how to disclose genetic research results have become pressing questions. The need is particularly acute in the case of LRRK2 research: Movement centers worldwide are recruiting cohorts of individuals with PD and their family members, including asymptomatic carriers, clinical features and treatment are complex and evolving, and disclosure policies vary at different sites and have been modified during the course of some studies. Herein, we present the major ethical principles of autonomy, beneficence, non-maleficence, and honesty that should guide disclosure policies in studies of families with LRRK2 mutations. We make recommendations regarding: genetic counseling, policies of either active or passive disclosure, responsibilities of funders to budget for genetic counseling, clinical genetic testing where locally required for disclosure, and aspects of study design to avoid mandatory disclosure whenever feasible. PMID:25952684

  2. Genetics, society, and decisions

    SciTech Connect

    Kowles, R.V.

    1985-01-01

    This book provides a conceptual understanding of the biology of genes and also gives current events and controversies in the field. Basic transmission genetics, molecular genetics, and population genetics are covered, with additional discussions relating to such topics as agriculture, aging, forensic science, genetic counseling, gene splicing, and recombinant DNA. Low level radiation and its effects, drugs and heredity, IQ, heredity and racial variation, and creationism versus evolution are also described. ''Billboard'' style diagrams visually explain important concepts. Boldfaced key terms are defined within the text and in a comprehensive glossary. Selected readings, discussion questions and problems, and excellent chapter summaries further aid study.

  3. a Study on the Role of Sintering Additives for Fabrication of sic Ceramic

    NASA Astrophysics Data System (ADS)

    Yoon, Han Ki; Lee, Young Ju; Cho, Ho Jun; Kim, Tae Gyu

    Silicon carbide (SiC) materials have been extensively studied for high temperature components in advanced energy system and advanced gas turbine. The SiC ceramics have been fabricated by a NITE (Nano Infiltration Transient Eutectic Phase) Process, using Nano-SiC powder. The sintering additives used for forming liquid phase under sintering process, used the sintering additives ratios were an Al2O3-Y2O3 system or add SiO2 contents. A major R&D focus for the SiC ceramics is the production to obtain high purity SiC ceramics. In this study, we investigated roles of the sintering additives(Al2O3:Y2O3) to fabrication of the SiC ceramics. The effects of SiO2 contents and density properties of the SiC ceramics were also investigated. To investigate the effects of SiO2, Al2O3/Y2O3 composition were fixed and then SiO2 ratios were changed as several kinds, and to confirm the effects of sintering additives ratios (Al2O3:Y2O3) they were changed between 4:6 and 6:4 in x wt.%.

  4. Designing and implementing sample and data collection for an international genetics study: the Type 1 Diabetes Genetics Consortium (T1DGC)

    PubMed Central

    Hilner, Joan E; Perdue, Letitia H; Sides, Elizabeth G; Pierce, June J; Wägner, Ana M; Aldrich, Alan; Loth, Amanda; Albret, Lotte; Wagenknecht, Lynne E; Nierras, Concepcion; Akolkar, Beena

    2010-01-01

    Background and Purpose The Type 1 Diabetes Genetics Consortium (T1DGC) is an international project whose primary aims are to: (a) discover genes that modify type 1 diabetes risk; and (b) expand upon the existing genetic resources for type 1 diabetes research. The initial goal was to collect 2500 affected sibling pair (ASP) families worldwide. Methods T1DGC was organized into four regional networks (Asia-Pacific, Europe, North America, and the United Kingdom) and a Coordinating Center. A Steering Committee, with representatives from each network, the Coordinating Center, and the funding organizations, was responsible for T1DGC operations. The Coordinating Center, with regional network representatives, developed study documents and data systems. Each network established laboratories for: DNA extraction and cell line production; human leukocyte antigen genotyping; and autoantibody measurement. Samples were tracked from the point of collection, processed at network laboratories and stored for deposit at National Institute for Diabetes and Digestive and Kidney Diseases (NIDDK) Central Repositories. Phenotypic data were collected and entered into the study database maintained by the Coordinating Center. Results T1DGC achieved its original ASP recruitment goal. In response to research design changes, the T1DGC infrastructure also recruited trios, cases, and controls. Results of genetic analyses have identified many novel regions that affect susceptibility to type 1 diabetes. T1DGC created a resource of data and samples that is accessible to the research community. Limitations Participation in T1DGC was declined by some countries due to study requirements for the processing of samples at network laboratories and/or final deposition of samples in NIDDK Central Repositories. Re-contact of participants was not included in informed consent templates, preventing collection of additional samples for functional studies. Conclusions T1DGC implemented a distributed

  5. Using epidemiology to regulate food additives: saccharin case-control studies.

    PubMed

    Cordle, F; Miller, S A

    1984-01-01

    The increasing use of nonnutritive sweeteners and the widely publicized 1969 ban on cyclamate led to additional investigations in rodents of the carcinogenic potential of saccharin. Preliminary results of a long-term feeding study indicated formation of bladder tumors in rodents, and collective experimental evidence has demonstrated that high doses of the synthetic sweetener saccharin can cause bladder cancer in rodents. Based on the results of that and other rodent studies indicating an increased risk of bladder cancer associated with saccharin, the Commissioner of the Food and Drug Administration announced the agency's intention to propose a ban on saccharin. This intention was made known in April 1977 under the Delaney Clause of the Food, Drug, and Cosmetic Act. The clause essentially states that no additive shall be deemed safe if it is found to induce cancer in man or animals, or if it is found, after tests appropriate for the evaluation of the safety of food additives, to induce cancer in man or animals. Also in 1977, a group of epidemiologists began to assess the available epidemiologic information to determine the potential human risk. This report describes the assessment of several human epidemiologic studies available then and the results of more recent epidemiologic studies. PMID:6431484

  6. Genetic Determinants of Age-Related Macular Degeneration in Diverse Populations From the PAGE Study

    PubMed Central

    Restrepo, Nicole A.; Spencer, Kylee L.; Goodloe, Robert; Garrett, Tiana A.; Heiss, Gerardo; Bůžková, Petra; Jorgensen, Neal; Jensen, Richard A.; Matise, Tara C.; Hindorff, Lucia A.; Klein, Barbara E. K.; Klein, Ronald; Wong, Tien Y.; Cheng, Ching-Yu; Cornes, Belinda K.; Tai, E.-Shyong; Ritchie, Marylyn D.; Haines, Jonathan L.; Crawford, Dana C.

    2014-01-01

    Purpose. Substantial progress has been made in identifying susceptibility variants for AMD in European populations; however, few studies have been conducted to understand the role these variants play in AMD risk in diverse populations. The present study aims to examine AMD risk across diverse populations in known and suspected AMD complement factor and lipid-related loci. Methods. Targeted genotyping was performed across study sites for AMD and lipid trait-associated single nucleotide polymorphism (SNPs). Genetic association tests were performed at individual sites and then meta-analyzed using logistic regression assuming an additive genetic model stratified by self-described race/ethnicity. Participants included cases with early or late AMD and controls with no signs of AMD as determined by fundus photography. Populations included in this study were European Americans, African Americans, Mexican Americans, and Singaporeans from the Population Architecture using Genomics and Epidemiology (PAGE) study. Results. Index variants of AMD, rs1061170 (CFH) and rs10490924 (ARMS2), were associated with AMD at P = 3.05 × 10−8 and P = 6.36 × 10−6, respectively, in European Americans. In general, none of the major AMD index variants generalized to our non-European populations with the exception of rs10490924 in Mexican Americans at an uncorrected P value < 0.05. Four lipid-associated SNPS (LPL rs328, TRIB1 rs6987702, CETP rs1800775, and KCTD10/MVK rs2338104) were associated with AMD in African Americans and Mexican Americans (P < 0.05), but these associations did not survive strict corrections for multiple testing. Conclusions. While most associations did not generalize in the non-European populations, variants within lipid-related genes were found to be associated with AMD. This study highlights the need for larger well-powered studies in non-European populations. PMID:25205864

  7. Perceived Competence and Self-Worth during Adolescence: A Longitudinal Behavioral Genetic Study.

    ERIC Educational Resources Information Center

    McGuire, Shirley; Manke, Beth; Saudino, Kimberly J.; Reiss, David; Hetherington, E. Mavis; Plomin, Robert

    1999-01-01

    This behavioral genetic study examined perceived competence and self-worth in same-sex twins, siblings, and stepsiblings 10 to 18 years old, and again 3 years later. Findings at second assessment showed six of seven subscales heritable. Genetic contributions to stability were found for perceived scholastic competence, athletic competence, physical…

  8. Examining Genetic and Environmental Effects on Social Aggression: A Study of 6-Year-Old Twins

    ERIC Educational Resources Information Center

    Brendgen, Mara; Dionne, Ginette; Girard, Alain; Boivin, Michel; Vitaro, Frank; Prusse, Daniel

    2005-01-01

    Using a genetic design of 234 six-year-old twins, this study examined (a) the contribution of genes and environment to social versus physical aggression, and (b) whether the correlation between social and physical aggression can be explained by similar genetic or environmental factors or by a directional link between the phenotypes. For social…

  9. Genetic thinking in the study of social relationships: Five points of entry

    PubMed Central

    Reiss, David

    2014-01-01

    For nearly a generation, researchers studying human behavioral development have combined genetically informed research designs with careful measures of social relationships: parenting, sibling relationships, peer relationships, marital processes, social class stratifications and patterns of social engagement in the elderly. In what way have these genetically informed studies altered the construction and testing of social theories of human development? We consider five points where genetic thinking is taking hold. First, genetic findings suggest an alternative scenario for explaining social data. Associations between measures of the social environment and human development may be due to genes that influence both. Second, genetic studies add to other prompts to study the early developmental origins of current social phenomena in mid-life and beyond. Third, genetic analyses promise to bring to the surface understudied social systems, such as sibling relationships, that have an impact on human development independent of genotype. Fourth, genetic analyses anchor in neurobiology individual differences in resilience and sensitivity to both adverse and favorable social environments. Finally, genetic analyses increase the utility of laboratory simulations of human social processes and of animal models. PMID:25419225

  10. Exposing college students to exercise: the training interventions and genetics of exercise response (TIGER) study

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Training Interventions and Genetics of Exercise Response (TIGER) study is an exercise program designed to introduce sedentary college students to regular physical activity and to identify genetic factors that influence response to exercise. A multiracial/ethnic cohort (N = 1,567; 39% male), age ...

  11. Are Endophenotypes Based on Measures of Executive Functions Useful for Molecular Genetic Studies of ADHD?

    ERIC Educational Resources Information Center

    Doyle, Alysa E.; Faraone, Stephen V.; Seidman, Larry J.; Willcutt, Erik G.; Nigg, Joel T.; Waldman, Irwin D.; Pennington, Bruce F.; Peart, Joanne; Biederman, Joseph

    2005-01-01

    Background: Behavioral genetic studies provide strong evidence that attention-deficit/hyperactivity disorder (ADHD) has a substantial genetic component. Yet, due to the complexity of the ADHD phenotype, questions remain as to the specific genes that contribute to this condition as well as the pathways from genes to behavior. Endophenotypes, or…

  12. A Genetically Informed Study of Associations between Family Functioning and Child Psychosocial Adjustment

    ERIC Educational Resources Information Center

    Schermerhorn, Alice C.; D'Onofrio, Brian M.; Turkheimer, Eric; Ganiban, Jody M.; Spotts, Erica L.; Lichtenstein, Paul; Reiss, David; Neiderhiser, Jenae M.

    2011-01-01

    Research has documented associations between family functioning and offspring psychosocial adjustment, but questions remain regarding whether these associations are partly due to confounding genetic factors and other environmental factors. The current study used a genetically informed approach, the Children of Twins design, to explore the…

  13. Exposing College Students to Exercise: The Training Interventions and Genetics of Exercise Response (TIGER) Study

    ERIC Educational Resources Information Center

    Sailors, Mary H.; Jackson, Andrew S.; McFarlin, Brian K.; Turpin, Ian; Ellis, Kenneth J.; Foreyt, John P.; Hoelscher, Deanna M.; Bray, Molly S.

    2010-01-01

    Objective: The Training Interventions and Genetics of Exercise Response (TIGER) study is an exercise program designed to introduce sedentary college students to regular physical activity and to identify genetic factors that influence response to exercise. Participants: A multiracial/ethnic cohort (N = 1,567; 39% male), age 18 to 35 years,…

  14. Clusters of Concepts in Molecular Genetics: A Study of Swedish Upper Secondary Science Students' Understanding

    ERIC Educational Resources Information Center

    Gericke, Niklas; Wahlberg, Sara

    2013-01-01

    To understand genetics, students need to be able to explain and draw connections between a large number of concepts. The purpose of the study reported herein was to explore the way upper secondary science students reason about concepts in molecular genetics in order to understand protein synthesis. Data were collected by group interviews. Concept…

  15. Study of asphalt/asphaltene precipitation during addition of solvents to West Sak crude

    SciTech Connect

    Jiang, J.C.; Patil, S.L.; Kamath, V.A. )

    1990-07-01

    In this study, experimental data on the amount of asphalt and asphaltene precipitation due to addition of solvents to West Sak crude were gathered. The first set of tests were conducted for two types of West Sak stock tank oils. Solvents used include: ethane, carbon dioxide, propane, n-butane, n-pentane, n-heptane, Prudhoe Bay natural gas (PBG) and natural gas liquids (NGL). Effect of solvent to oil dilution ratio on the amount of precipitation was studied. Alteration of crude oil composition due to asphalt precipitation was measured using gas-liquid chromatography. A second set of experiments were conducted to measure asphaltene precipitation due to addition of CO{sub 2} to live (recombined) West Sak crude.

  16. Novel Approaches to Studying the Genetic Basis of Cerebellar Development

    PubMed Central

    Sajan, Samin A.; Waimey, Kathryn E.

    2010-01-01

    The list of genes that when mutated cause disruptions in cerebellar development is rapidly increasing. The study of both spontaneous and engineered mouse mutants has been essential to this progress, as it has revealed much of our current understanding of the developmental processes required to construct the mature cerebellum. Improvements in brain imaging, such as magnetic resonance imaging (MRI) and the emergence of better classification schemes for human cerebellar malformations, have recently led to the identification of a number of genes which cause human cerebellar disorders. In this review we argue that synergistic approaches combining classical molecular techniques, genomics, and mouse models of human malformations will be essential to fuel additional discoveries of cerebellar developmental genes and mechanisms. PMID:20387026

  17. A Study of Aluminum Combustion in Solids, Powders, Foams, Additively-Manufactured Lattices, and Composites

    NASA Astrophysics Data System (ADS)

    Black, James; Trammell, Norman; Batteh, Jad; Curran, Nicholas; Rogers, John; Littrell, Donald

    2015-06-01

    This study examines the fireball characteristics, blast parameters, and combustion efficiency of explosively-shocked aluminum-based materials. The materials included structural and non-structural aluminum forms - such as solid cylinders, foams, additively-manufactured lattices, and powders - and some polytetrafluoroethylene-aluminum (PTFE-Al) composites. The materials were explosively dispersed in a small blast chamber, and the blast properties and products were measured with pressure transducers, thermocouples, slow and fast ultraviolet/visible spectrometers, and high-speed video.

  18. Spectra-temporal patterns underlying mental addition: an ERP and ERD/ERS study.

    PubMed

    Ku, Yixuan; Hong, Bo; Gao, Xiaorong; Gao, Shangkai

    2010-03-12

    Functional neuroimaging data have shown that mental calculation involves fronto-parietal areas that are composed of different subsystems shared with other cognitive functions such as working memory and language. Event-related potential (ERP) analysis has also indicated sequential information changes during the calculation process. However, little is known about the dynamic properties of oscillatory networks in this process. In the present study, we applied both ERP and event-related (de-)synchronization (ERS/ERD) analyses to EEG data recorded from normal human subjects performing tasks for sequential visual/auditory mental addition. Results in the study indicate that the late positive components (LPCs) can be decomposed into two separate parts. The earlier element LPC1 (around 360ms) reflects the computing attribute and is more prominent in calculation tasks. The later element LPC2 (around 590ms) indicates an effect of number size and appears larger only in a more complex 2-digit addition task. The theta ERS and alpha ERD show modality-independent frontal and parietal differential patterns between the mental addition and control groups, and discrepancies are noted in the beta ERD between the 2-digit and 1-digit mental addition groups. The 2-digit addition (both visual and auditory) results in similar beta ERD patterns to the auditory control, which may indicate a reliance on auditory-related resources in mental arithmetic, especially with increasing task difficulty. These results coincide with the theory of simple calculation relying on the visuospatial process and complex calculation depending on the phonological process. PMID:20105450

  19. Human genetic studies in areas of high natural radiation. VIII. Genetic load not related to radiation.

    PubMed Central

    Freire-Maia, A; Krieger, H

    1975-01-01

    The genetic load disclosed by inbreeding has been analyzed in a multiple regression model for a population involving several localities in the state of Espírito Santo, Brazil. The inbreeding load has been estimated for number of pregnancies, abortions, stillbirths, children born alive, anomalies in general, sex ratio, infant mortality, post-infant mortality, and sterility and infertility of the couple. There was no evidence of either maternal or paternal inbreeding effects on the variables analyzed. The effect of inbreeding of the zygote was significant only for anomalies in general (B = 2.29 +/- 0.45) and infant mortality (B = 3.19 +/- 1.39). The latter result must be accepted with caution because of the many environmental causes affecting infant mortality. The B/A ratio suggested a predominantly mutational load for anomalies in general (B/A = 25), but with respect to infant mortality (B/A = 6), the ratio is regarded as an underestimate because of the environmental contribution to A and therefore not supportive of the segregational interpretation. PMID:803018

  20. [A comparative study on genetic polymorphism and genetic relationship of 13 SNPs in three Chinese populations].

    PubMed

    Wang, Rui-Heng; Liu, Li-Min; Zhao, Jin-Ling

    2009-03-01

    Using the fluorescence labeled capillary electrophoresis of multi-PCR technique, the single nucleotide polymorphism (SNP) typing system of fragment length discrepant allele specific fluorescence labeled multi-PCR technique is established based on the principle of allele-specific PCR. The typing of the 13 SNP loci can be completed simultaneously according to the length of PCR products and the number of product peaks. It appears a single product peak when the SNP is homozygous, and two product peaks with 4 bp differences will appear when it is heterozygous. By using this system, we conducted population census about allele frequencies for 13 autosomal SNP loci in Southern Liaoning Han samples, Mongolian samples in Inner Mongolia and Zhuang samples in Guangxi area, and got the allele frequencies of the 13 SNP loci in the three populations, then preliminarily discussed their genetic relationship by comparing their differences in allelic polymorphism. The results indicate that the allelic distributions of the 13 SNP loci in the three populations are polymorphic, and the difference is significant in some SNP loci (P< or =0.01). The sampling survey shows that the result is consistent with Hardy-Weinberg equilibrium, and Han population in southern Liaoning has relatively closer relationship with Mongolian in Inner Mongolia than with Zhuang population in Guangxi by origin. PMID:19273440

  1. Heritability and Molecular-Genetic Basis of Resting EEG Activity: A Genome-Wide Association Study

    PubMed Central

    Malone, Stephen M.; Burwell, Scott J.; Vaidyanathan, Uma; Miller, Michael B.; McGue, Matt; Iacono, William G.

    2014-01-01

    Several EEG parameters are potential endophenotypes for different psychiatric disorders. The present study consists of a comprehensive behavioral- and molecular-genetic analysis of such parameters in a large community sample (N = 4,026) of adolescent twins and their parents, genotyped for 527,829 single nucleotide polymorphisms (SNPs). Biometric heritability estimates ranged from .49 to .85, with a median of .78. The additive effect of all SNPs (SNP heritability) varied across electrodes. Although individual SNPs were not significantly associated with EEG parameters, several genes were associated with delta power. We also obtained an association between the GABRA2 gene and beta power (p < .014), consistent with findings reported by others, although this did not survive Bonferroni correction. If EEG parameters conform to a largely polygenic model of inheritance, larger sample sizes will be required to detect individual variants reliably. PMID:25387704

  2. Genetics studies indicate that neural induction and early neuronal maturation are disturbed in autism

    PubMed Central

    Casanova, Emily L.; Casanova, Manuel F.

    2014-01-01

    Postmortem neuropathological studies of autism consistently reveal distinctive types of malformations, including cortical dysplasias, heterotopias, and various neuronomorphometric abnormalities. In keeping with these observations, we review here that 88% of high-risk genes for autism influence neural induction and early maturation of the neuroblast. In addition, 80% of these same genes influence later stages of differentiation, including neurite and synapse development, suggesting that these gene products exhibit long-lasting developmental effects on cell development as well as elements of redundancy in processes of neural proliferation, growth, and maturation. We also address the putative genetic overlap of autism with conditions like epilepsy and schizophrenia, with implications to shared and divergent etiologies. This review imports the necessity of a frameshift in our understanding of the neurodevelopmental basis of autism to include all stages of neuronal maturation, ranging from neural induction to synaptogenesis. PMID:25477785

  3. Sociodemographic, behavioral and genetic determinants of allostatic load in a Swiss population-based study.

    PubMed

    Petrovic, Dusan; Pivin, Edward; Ponte, Belen; Dhayat, Nasser; Pruijm, Menno; Ehret, Georg; Ackermann, Daniel; Guessous, Idris; Younes, Sandrine Estoppey; Pechère-Bertschi, Antoinette; Vogt, Bruno; Mohaupt, Markus; Martin, Pierre-Yves; Paccaud, Fred; Burnier, Michel; Bochud, Murielle; Stringhini, Silvia

    2016-05-01

    Allostatic load (AL) is a marker of physiological dysregulation which reflects exposure to chronic stress. High AL has been related to poorer health outcomes including mortality. We examine here the association of socioeconomic and lifestyle factors with AL. Additionally, we investigate the extent to which AL is genetically determined. We included 803 participants (52% women, mean age 48±16years) from a population and family-based Swiss study. We computed an AL index aggregating 14 markers from cardiovascular, metabolic, lipidic, oxidative, hypothalamus-pituitary-adrenal and inflammatory homeostatic axes. Education and occupational position were used as indicators of socioeconomic status. Marital status, stress, alcohol intake, smoking, dietary patterns and physical activity were considered as lifestyle factors. Heritability of AL was estimated by maximum likelihood. Women with a low occupational position had higher AL (low vs. high OR=3.99, 95%CI [1.22;13.05]), while the opposite was observed for men (middle vs. high OR=0.48, 95%CI [0.23;0.99]). Education tended to be inversely associated with AL in both sexes(low vs. high OR=3.54, 95%CI [1.69;7.4]/OR=1.59, 95%CI [0.88;2.90] in women/men). Heavy drinking men as well as women abstaining from alcohol had higher AL than moderate drinkers. Physical activity was protective against AL while high salt intake was related to increased AL risk. The heritability of AL was estimated to be 29.5% ±7.9%. Our results suggest that generalized physiological dysregulation, as measured by AL, is determined by both environmental and genetic factors. The genetic contribution to AL remains modest when compared to the environmental component, which explains approximately 70% of the phenotypic variance. PMID:26881833

  4. Chromosome 2p shows significant linkage to antihypertensive response in the British Genetics of Hypertension Study.

    PubMed

    Padmanabhan, Sandosh; Wallace, Chris; Munroe, Patricia B; Dobson, Richard; Brown, Morris; Samani, Nilesh; Clayton, David; Farrall, Martin; Webster, John; Lathrop, Mark; Caulfield, Mark; Dominiczak, Anna F; Connell, John M

    2006-03-01

    There is a lack of consistently linked loci influencing blood pressure and hypertension status, and this may be because of genetic or phenotypic heterogeneity. We hypothesize that stratification of subjects by response to antihypertensive drug groups could be used to stringently define subsets that will have reduced genetic and etiologic heterogeneity, by partitioning contrasting mechanisms of hypertension and, thus, enhancing gene finding. We investigated the British Genetics of Hypertension Study population, which is composed of 2142 severely hypertensive white affected sibling pairs. Nonresponse to antihypertensive therapy was defined as an on-treatment blood pressure of >140/90 mm Hg or a difference between prediagnosis and on-treatment blood pressure of <20 mm Hg. Of the nonresponders, there were 89 sibling pairs (AB) who were both on antihypertensive therapy that inhibit the renin-angiotensin system (angiotensin-converting enzyme inhibitors, angiotensin II type-1 receptor blockers, or beta-blockers), and 76 sibling pairs (CD) who were both on drugs that do not (calcium channel blockers or diuretics). Nonparametric linkage analysis carried out using markers from a 10-cM genome scan and additional "grid tightening" markers showed significant linkage in the AB group on chromosome 2p (logarithm of odds=4.84 at 90.68 Kosambi cM) and suggestive linkage for the CD group on chromosome 10q (logarithm of odds=2.83 at 125.96 Kosambi cM). The AB linkage locus attained genomewide significance after simulation using 10,000 replicates (P=0.005). This locus may contain a gene for the salt-sensitive form of hypertension and/or a pharmacogenetic locus affecting drug response. We have demonstrated for the first time identification of a significant locus by partitioning different pathways of hypertension using drug response. PMID:16391175

  5. Genetic association study of circadian genes with seasonal pattern in bipolar disorders

    PubMed Central

    Geoffroy, Pierre Alexis; Lajnef, Mohamed; Bellivier, Frank; Jamain, Stéphane; Gard, Sébastien; Kahn, Jean-Pierre; Henry, Chantal; Leboyer, Marion; Etain, Bruno

    2015-01-01

    About one fourth of patients with bipolar disorders (BD) have depressive episodes with a seasonal pattern (SP) coupled to a more severe disease. However, the underlying genetic influence on a SP in BD remains to be identified. We studied 269 BD Caucasian patients, with and without SP, recruited from university-affiliated psychiatric departments in France and performed a genetic single-marker analysis followed by a gene-based analysis on 349 single nucleotide polymorphisms (SNPs) spanning 21 circadian genes and 3 melatonin pathway genes. A SP in BD was nominally associated with 14 SNPs identified in 6 circadian genes: NPAS2, CRY2, ARNTL, ARNTL2, RORA and RORB. After correcting for multiple testing, using a false discovery rate approach, the associations remained significant for 5 SNPs in NPAS2 (chromosome 2:100793045–100989719): rs6738097 (pc = 0.006), rs12622050 (pc = 0.006), rs2305159 (pc = 0.01), rs1542179 (pc = 0.01), and rs1562313 (pc = 0.02). The gene-based analysis of the 349 SNPs showed that rs6738097 (NPAS2) and rs1554338 (CRY2) were significantly associated with the SP phenotype (respective Empirical p-values of 0.0003 and 0.005). The associations remained significant for rs6738097 (NPAS2) after Bonferroni correction. The epistasis analysis between rs6738097 (NPAS2) and rs1554338 (CRY2) suggested an additive effect. Genetic variations in NPAS2 might be a biomarker for a seasonal pattern in BD. PMID:25989161

  6. The Double Pedigree: A Method for Studying Culturally and Genetically Inherited Behavior in Tandem

    PubMed Central

    Danchin, Etienne; Pujol, Benoit; Wagner, Richard H.

    2013-01-01

    Transgenerational sources of biological variation have been at the center of evolutionary studies ever since Darwin and Wallace identified natural selection. This is because evolution can only operate on traits whose variation is transmitted, i.e. traits that are heritable. The discovery of genetic inheritance has led to a semantic shift, resulting in the tendency to consider that only genes are inherited across generations. Today, however, concepts of heredity are being broadened again to integrate the accruing evidence of non-genetic inheritance, and many evolutionary biologists are calling for the inclusion of non-genetic inheritance into an inclusive evolutionary synthesis. Here, we focus on social heredity and its role in the inheritance of behavioral traits. We discuss quantitative genetics methods that might allow us to disentangle genetic and non-genetic transmission in natural populations with known pedigrees. We then propose an experimental design based on cross-fostering among animal cultures, environments and families that has the potential to partition inherited phenotypic variation into socially (i.e. culturally) and genetically inherited components. This approach builds towards a new conceptual framework based on the use of an extended version of the animal model of quantitative genetics to integrate genetic and cultural components of behavioral inheritance. PMID:23700404

  7. Genetic testing of newborns for type 1 diabetes susceptibility: a prospective cohort study on effects on maternal mental health

    PubMed Central

    2010-01-01

    Background Concerns about the general psychological impact of genetic testing have been raised. In the Environmental Triggers of Type 1 Diabetes (MIDIA) study, genetic testing was performed for HLA-conferred type 1 diabetes susceptibility among Norwegian newborns. The present study assessed whether mothers of children who test positively suffer from poorer mental health and well-being after receiving genetic risk information about their children. Methods The study was based on questionnaire data from the Norwegian Mother and Child Cohort (MoBa) study conducted by the Norwegian Institute of Public Health. Many of the mothers in the MoBa study also took part in the MIDIA study, in which their newborn children were tested for HLA-conferred genetic susceptibility for type 1 diabetes. We used MoBa questionnaire data from the 30th week of pregnancy (baseline) and 6 months post-partum (3-3.5 months after disclosure of test results). We measured maternal symptoms of anxiety and depression (SCL-8), maternal self-esteem (RSES), and satisfaction with life (SWLS). The mothers also reported whether they were seriously worried about their child 6 months post-partum. We compared questionnaire data from mothers who had received information about having a newborn with high genetic risk for type 1 diabetes (N = 166) with data from mothers who were informed that their baby did not have a high-risk genotype (N = 7224). The association between genetic risk information and maternal mental health was analysed using multiple linear regression analysis, controlling for baseline mental health scores. Results Information on genetic risk in newborns was found to have no significant impact on maternal symptoms of anxiety and depression (p = 0.9), self-esteem (p = 0.2), satisfaction with life (p = 0.2), or serious worry about their child (OR = 0.98, 95% CI 0.64-1.48). Mental health before birth was strongly associated with mental health after birth. In addition, an increased risk of maternal

  8. Protocol for investigating genetic determinants of posttraumatic stress disorder in women from the Nurses' Health Study II

    PubMed Central

    Koenen, Karestan C; DeVivo, Immaculata; Rich-Edwards, Janet; Smoller, Jordan W; Wright, Rosalind J; Purcell, Shaun M

    2009-01-01

    represent a major advance in understanding the pathophysiology of the disorder. Such understanding could advance the development of new pharmacological agents for PTSD treatment and prevention. Moreover, the addition of PTSD assessment data will make the NHSII cohort an unparalleled resource for future genetic studies of PTSD as well as provide the unique opportunity for the prospective examination of PTSD-disease associations. PMID:19480706

  9. Retrospective likelihood-based methods for analyzing case-cohort genetic association studies.

    PubMed

    Shen, Yuanyuan; Cai, Tianxi; Chen, Yu; Yang, Ying; Chen, Jinbo

    2015-12-01

    The case cohort (CCH) design is a cost-effective design for assessing genetic susceptibility with time-to-event data especially when the event rate is low. In this work, we propose a powerful pseudo-score test for assessing the association between a single nucleotide polymorphism (SNP) and the event time under the CCH design. The pseudo-score is derived from a pseudo-likelihood which is an estimated retrospective likelihood that treats the SNP genotype as the dependent variable and time-to-event outcome and other covariates as independent variables. It exploits the fact that the genetic variable is often distributed independent of covariates or only related to a low-dimensional subset. Estimates of hazard ratio parameters for association can be obtained by maximizing the pseudo-likelihood. A unique advantage of our method is that it allows the censoring distribution to depend on covariates that are only measured for the CCH sample while not requiring the knowledge of follow-up or covariate information on subjects not selected into the CCH sample. In addition to these flexibilities, the proposed method has high relative efficiency compared with commonly used alternative approaches. We study large sample properties of this method and assess its finite sample performance using both simulated and real data examples. PMID:26177343

  10. Genetic studies provide clues on the pathogenesis of idiopathic pulmonary fibrosis.

    PubMed

    Kropski, Jonathan A; Lawson, William E; Young, Lisa R; Blackwell, Timothy S

    2013-01-01

    Idiopathic pulmonary fibrosis (IPF) is a progressive and often fatal lung disease for which there is no known treatment. Although the traditional paradigm of IPF pathogenesis emphasized chronic inflammation as the primary driver of fibrotic remodeling, more recent insights have challenged this view. Linkage analysis and candidate gene approaches have identified four genes that cause the inherited form of IPF, familial interstitial pneumonia (FIP). These four genes encode two surfactant proteins, surfactant protein C (encoded by SFTPC) and surfactant protein A2 (SFTPA2), and two components of the telomerase complex, telomerase reverse transcriptase (TERT) and the RNA component of telomerase (TERC). In this review, we discuss how investigating these mutations, as well as genetic variants identified in other inherited disorders associated with pulmonary fibrosis, are providing new insights into the pathogenesis of common idiopathic interstitial lung diseases, particularly IPF. Studies in this area have highlighted key roles for epithelial cell injury and dysfunction in the development of lung fibrosis. In addition, genetic approaches have uncovered the importance of several processes - including endoplasmic reticulum stress and the unfolded protein response, DNA-damage and -repair pathways, and cellular senescence - that might provide new therapeutic targets in fibrotic lung diseases. PMID:23268535

  11. Mineral resources of the Buffalo Hump and Sand Dunes Addition Wilderness Study Areas, Sweetwater County, Wyoming

    SciTech Connect

    Gibbons, A.B.; Barbon, H.N.; Kulik, D.M. ); McDonnell, J.R. Jr. )

    1990-01-01

    The authors present a study to assess the potential for undiscovered mineral resources and appraise the identified resources of the Buffalo Hump and Sand Dunes Addition Wilderness Study Areas, southwestern Wyoming, There are no mines, prospects, or mineralized areas nor any producing oil or gas wells; however, there are occurrences of coal, claystone and shale, and sand. There is a moderate resource potential for oil shale and natural gas and a low resource potential for oil, for metals, including uranium, and for geothermal sources.

  12. Cumulative association between age-related macular degeneration and less studied genetic variants in PLEKHA1/ARMS2/HTRA1: a meta and gene-cluster analysis

    PubMed Central

    Yu, Weihong; Dong, Shuqian; Zhao, Chuntao; Wang, Haina; Dai, Fei; Yang, Jingyun

    2013-01-01

    The objective of this study is to examine the cumulative effect of the less studied genetic variants in PLEKHA1/ARMS2/HTRA1 on age-related macular degeneration (AMD). We performed an extensive literature search for studies on the association between AMD and the less studied genetic variants in PLEKHA1/ARMS2/HTRA1. Multiple meta-analyses were performed to evaluate the association between individual genetic variants and AMD. A gene-cluster analysis was used to investigate the cumulative effect of these less studied genetic variants on AMD. A total of 23 studies from 20 published papers met the eligibility criteria and were included in our analyses. Several genetic variants in the gene cluster are significantly associated with AMD in our meta-analyses or in individual studies. Gene-cluster analysis reveals a strong cumulative association between these genetic variants in this gene cluster and AMD (p<10−5). However, two previously suspected SNPs in ARMS2, including rs2736911, the SNP having the largest number of studies in our meta-analyses; and rs3793917, the SNP with the largest sample size, were not significantly associated with AMD (both p’s>0.12). Sensitivity analyses reveal significant association of AMD with rs2736911 in Chinese but not in Caucasian, with c.372_815del443ins54 in Caucasian but not in Chinese, and with rs1049331 in both ethnic groups. These less studied genetic variants have a significant cumulative effect on wet AMD. Our study provides evidence of the joint contribution of genetic variants in PLEKHA1/ARMS2/HTRA1 to AMD risk, in addition to the two widely studied genetic variants whose association with AMD was well established. PMID:24013816

  13. Genetic and environmental effects on openness to experience, agreeableness, and conscientiousness: an adoption/twin study.

    PubMed

    Bergeman, C S; Chipuer, H M; Plomin, R; Pedersen, N L; McClearn, G E; Nesselroade, J R; Costa, P T; McCrae, R R

    1993-06-01

    Previous research has indicated that extraversion and neuroticism are substantially affected both by genotype and environment. This study assesses genetic and environmental influences on the other three components of the five-factor model of personality: Openness to Experience, Agreeableness, and Conscientiousness. An abbreviated version of the NEO Personality Inventory (NEO-PI) was administered to 82 pairs of identical twins and 171 pairs of fraternal twins reared apart and 132 pairs of identical twins and 167 pairs of fraternal twins reared together. Estimates of genetic and environmental effects for Openness and Conscientiousness were similar to those found in other studies of personality: Genetic influence was substantial and there was little evidence of shared rearing environment. Results for Agreeableness were different: Genetic influence accounted for only 12% of the variance and shared rearing environment accounted for 21% of the variance. Few significant gender or age differences for genetic and environmental parameters were found in model-fitting analyses. PMID:8345444

  14. Genome-wide association studies identify genetic loci for low von Willebrand factor levels.

    PubMed

    van Loon, Janine; Dehghan, Abbas; Weihong, Tang; Trompet, Stella; McArdle, Wendy L; Asselbergs, Folkert F W; Chen, Ming-Huei; Lopez, Lorna M; Huffman, Jennifer E; Leebeek, Frank W G; Basu, Saonli; Stott, David J; Rumley, Ann; Gansevoort, Ron T; Davies, Gail; Wilson, James J F; Witteman, Jacqueline C M; Cao, Xiting; de Craen, Anton J M; Bakker, Stephan J L; Psaty, Bruce M; Starr, John M; Hofman, Albert; Wouter Jukema, J; Deary, Ian J; Hayward, Caroline; van der Harst, Pim; Lowe, Gordon D O; Folsom, Aaron R; Strachan, David P; Smith, Nicolas; de Maat, Moniek P M; O'Donnell, Christopher

    2016-07-01

    Low von Willebrand factor (VWF) levels are associated with bleeding symptoms and are a diagnostic criterion for von Willebrand disease, the most common inherited bleeding disorder. To date, it is unclear which genetic loci are associated with reduced VWF levels. Therefore, we conducted a meta-analysis of genome-wide association studies to identify genetic loci associated with low VWF levels. For this meta-analysis, we included 31 149 participants of European ancestry from 11 community-based studies. From all participants, VWF antigen (VWF:Ag) measurements and genome-wide single-nucleotide polymorphism (SNP) scans were available. Each study conducted analyses using logistic regression of SNPs on dichotomized VWF:Ag measures (lowest 5% for blood group O and non-O) with an additive genetic model adjusted for age and sex. An inverse-variance weighted meta-analysis was performed for VWF:Ag levels. A total of 97 SNPs exceeded the genome-wide significance threshold of 5 × 10(-8) and comprised five loci on four different chromosomes: 6q24 (smallest P-value 5.8 × 10(-10)), 9q34 (2.4 × 10(-64)), 12p13 (5.3 × 10(-22)), 12q23 (1.2 × 10(-8)) and 13q13 (2.6 × 10(-8)). All loci were within or close to genes, including STXBP5 (Syntaxin Binding Protein 5) (6q24), STAB5 (stabilin-5) (12q23), ABO (9q34), VWF (12p13) and UFM1 (ubiquitin-fold modifier 1) (13q13). Of these, UFM1 has not been previously associated with VWF:Ag levels. Four genes that were previously associated with VWF levels (VWF, ABO, STXBP5 and STAB2) were also associated with low VWF levels, and, in addition, we identified a new gene, UFM1, that is associated with low VWF levels. These findings point to novel mechanisms for the occurrence of low VWF levels. PMID:26486471

  15. Additional Treatment Services in a Cocaine Treatment Study: Level of Services Obtained and Impact on Outcome

    PubMed Central

    Worley, Matthew; Gallop, Robert; Gibbons, Mary Beth Connolly; Ring-Kurtz, Sarah; Present, Julie; Weiss, Roger D.; Crits-Christoph, Paul

    2009-01-01

    The objective of this study was to examine the level of additional treatment services obtained by patients enrolled in the NIDA Cocaine Collaborative Study, a multi-center efficacy trial of four treatments for cocaine dependence, and to determine whether these services impact treatment outcome. Cocaine-dependent patients (N = 487) were recruited at five sites and randomly assigned to six months of one of four psychosocial treatments. Assessments were made at baseline, monthly during treatment, and at follow-ups at 9, 12, 15, and 18 months post-randomization. On average, patients received little or no additional treatment services during active treatment (first 6 months), but the rate of obtaining most services increased during the follow-up phase (month 7 to 18). In general, the treatment groups did not differ in the rates of obtaining non-protocol services. For all treatment groups, patients with greater psychiatric severity received more medical and psychiatric services during active treatment and follow-up. Use of treatment services was unrelated to drug use outcomes during active treatment. However, during the follow-up period, increased use of psychiatric medication, 12-step attendance, and 12-step participation was related to less drug use. The results suggest that during uncontrolled follow-up phases, additional non-protocol services may potentially confound the interpretation of treatment group comparisons in drug use outcomes. PMID:18463998

  16. Genetic causes of intellectual disability in a birth cohort: A population‐based study

    PubMed Central

    Riegel, Mariluce; Segal, Sandra L.; Félix, Têmis M.; Barros, Aluísio J. D.; Santos, Iná S.; Matijasevich, Alicia; Giugliani, Roberto; Black, Maureen

    2015-01-01

    Intellectual disability affects approximately 1–3% of the population and can be caused by genetic and environmental factors. Although many studies have investigated the etiology of intellectual disability in different populations, few studies have been performed in middle‐income countries. The present study estimated the prevalence of genetic causes related to intellectual disability in a cohort of children from a city in south Brazil who were followed from birth. Children who showed poor performance in development and intelligence tests at the ages of 2 and 4 were included. Out of 4,231 liveborns enrolled in the cohort, 214 children fulfilled the inclusion criteria. A diagnosis was established in approximately 90% of the children evaluated. Genetic causes were determined in 31 of the children and 19 cases remained unexplained even after extensive investigation. The overall prevalence of intellectual disability in this cohort due to genetic causes was 0.82%. Because this study was nested in a cohort, there were a large number of variables related to early childhood and the likelihood of information bias was minimized by collecting information with a short recall time. This study was not influenced by selection bias, allowing identification of intellectual disability and estimation of the prevalence of genetic causes in this population, thereby increasing the possibility of providing appropriate management and/or genetic counseling. © 2015 The Authors. American Journal of Medical Genetics Part A Published by Wiley Periodicals, Inc. PMID:25728503

  17. Parameterization of interatomic potential by genetic algorithms: A case study

    SciTech Connect

    Ghosh, Partha S. Arya, A.; Dey, G. K.; Ranawat, Y. S.

    2015-06-24

    A framework for Genetic Algorithm based methodology is developed to systematically obtain and optimize parameters for interatomic force field functions for MD simulations by fitting to a reference data base. This methodology is applied to the fitting of ThO{sub 2} (CaF{sub 2} prototype) – a representative of ceramic based potential fuel for nuclear applications. The resulting GA optimized parameterization of ThO{sub 2} is able to capture basic structural, mechanical, thermo-physical properties and also describes defect structures within the permissible range.

  18. Association of genetic variants with coronary artery disease and ischemic stroke in a longitudinal population-based genetic epidemiological study

    PubMed Central

    YAMADA, YOSHIJI; MATSUI, KOTA; TAKEUCHI, ICHIRO; FUJIMAKI, TETSUO

    2015-01-01

    Our previous studies identified nine genes and chromosomal region 3q28 as susceptibility loci for myocardial infarction, ischemic stroke or chronic kidney disease by genome-wide or candidate gene association studies. As coronary artery disease (CAD) and ischemic stroke may share genetic architecture, certain genetic variants may confer susceptibility to the two diseases. The present study examined the association of 13 polymorphisms at these 10 loci with the prevalence of CAD or ischemic stroke in community-dwelling individuals, with the aim of identifying genetic variants that confer susceptibility to the two conditions. Study subjects (170 with CAD, 117 with ischemic stroke and 5,718 controls) were recruited to the Inabe Health and Longevity Study, a longitudinal genetic epidemiological study of atherosclerotic, cardiovascular and metabolic diseases. The subjects were recruited from individuals who visited for an annual health checkup and they were followed up each year (mean follow-up period, 5 years). Longitudinal analysis with a generalized estimating equation, and with adjustment for age, gender, body mass index, smoking status, the prevalence of hypertension, diabetes mellitus and dyslipidemia and the serum concentration of creatinine, revealed that rs2074380 (G→A) and rs2074381 (A→G) of the α-kinase 1 (ALPK1) gene and rs8089 (T→G) of the thrombospondin 2 (THBS2) gene were significantly (P<2×10−16) associated with the prevalence of CAD, with the AA genotype of rs2074380 and GG genotypes of rs2074381 and rs8089 being protective against this condition. Similar analysis revealed that rs9846911 (A→G) at chromosome 3q28, rs2074381 of ALPK1, rs8089 of THBS2 and rs6046 (G→A) of the coagulation factor VII gene were significantly (P<2×10−16) associated with the prevalence of ischemic stroke, with the GG genotypes of rs9846911, rs2074381 and rs8089 and the AA genotype of rs6046 being protective against this condition. ALPK1 and THBS2 may thus be

  19. Short communication: a genetic study of mortality in Danish Jersey heifer calves.

    PubMed

    Norberg, E; Pryce, J E; Pedersen, J

    2013-06-01

    The aim of this study was to estimate genetic parameters for mortality of Jersey heifer calves during the first 6 mo after birth, calculate the genetic trend of the trait, and estimate breeding values of widely used Jersey sires. More than 260,000 heifer calves were included in the study. The mortality traits included in the analysis were defined as mortality in 8 different periods from 24h after birth to age 180 d (d 1-14, d 15-30, d 31-60, d 61-90, d 91-120, d 121-150, and d 151-180) and mortality over the entire period. A linear model was used for estimation of genetic parameters, breeding values of sires, and genetic trend. Fixed effects included in the model were herd-year class, month of birth, parity of mother, and whether the calf was sold to another farm in the first 6 mo. Both direct and maternal genetic effects were included in the model; however, the maternal genetic effect was very small and not significant. The mortality rate was highest in the first month after birth (7.8%). Total mortality in the first 180 d was 12.5%. Direct heritabilities of mortality were quite low, ranging from 0.002 to 0.03 on the observable scale and 0.025 to 0.076 on the underlying scale. Maternal heritabilities were even lower. The genetic correlation between mortality from d 1 to 14 and d 1 to 180 was estimated to be 0.88, although by definition, these 2 traits share the same observations for many records. No clear genetic trend existed over the last 20 yr; however, considerable genetic variation exists. The best and the worst sires differed by about 8% in their estimated breeding values of mortality in the first 180 d. Based on the results obtained in this study, genetic selection for reducing calf mortality should be possible. PMID:23587388

  20. Genetic thromobophilia in pregnancy: a case-control study among North Indian women.

    PubMed

    Kaur, Lovejeet; Puri, Manju; Kaushik, Shweta; Sachdeva, Mohinder Pal; Trivedi, Shubha Sagar; Saraswathy, Kallur Nava

    2013-02-01

    In the present study, an attempt is made to understand the role of genetic thrombophilias i.e. MTHFR C677T and FVL in the causation of various pregnancy complications like pregnancy induced hypertension (PIH), recurrent abortions, intra-uterine growth retardation (IUGR) and intra-uterine death on the whole and also individually along with the comparative assessment of pathophysiological basis of various pregnancy complications via the genetic proximities. One thousand and eleven (1,011) women of reproductive age group were recruited in the present study comprising various complications and controls. Recruitment criteria for all the pregnancy complications and controls was made and followed strictly. MTHFR C677T and FVL mutation detection was done in all the subjects. Vegetarianism was found to be significant risk factors for all the pregnancy complications and also when assessed individually. With respect to MTHFR C677T polymorphism, higher frequency of 677T allele was found among controls as compared to cases. 677T allele was found to pose decreased risk for various pregnancy complications on the whole and also individually. On adjusting the diet, regression analysis revealed no risk of mutant allele (T) for various pregnancy complications. FVL homozygous mutants were found to be absent among controls. In conclusion, the present study depicts dietary pattern as one of the most important factors in demonstrating the role of MTHFR C677T in various pregnancy complications and is indicative of a relatively deleterious effect of double dose of FVL in the presently studied population. Additionally, these polymorphisms play an important role in the orchestration of PIH to IUGR and vice versa. PMID:22918664

  1. A synchrotron study of microstructure gradient in laser additively formed epitaxial Ni-based superalloy

    DOE PAGESBeta

    Xue, Jiawei; Zhang, Anfeng; Li, Yao; Qian, Dan; Wan, Jingchun; Qi, Baolu; Tamura, Nobumichi; Song, Zhongxiao; Chen, Kai

    2015-10-08

    Laser additive forming is considered to be one of the promising techniques to repair single crystal Ni-based superalloy parts to extend their life and reduce the cost. Preservation of the single crystalline nature and prevention of thermal mechanical failure are two of the most essential issues for the application of this technique. Here we employ synchrotron X-ray microdiffraction to evaluate the quality in terms of crystal orientation and defect distribution of a Ni-based superalloy DZ125L directly formed by a laser additive process rooted from a single crystalline substrate of the same material. We show that a disorientation gradient caused bymore » a high density of geometrically necessary dislocations and resultant subgrains exists in the interfacial region between the epitaxial and stray grains. This creates a potential relationship of stray grain formation and defect accumulation. In conclusion, the observation offers new directions on the study of performance control and reliability of the laser additive manufactured superalloys.« less

  2. Isomeric Selective Studies of the Dominant Addition Channel in OH Initiated Oxidation of Isoprene

    NASA Astrophysics Data System (ADS)

    Ghosh, B.; Bugarin, A.; Connell, B.; North, S. W.

    2009-12-01

    We report the first isomeric selective study of the dominant isomeric pathway in the OH initiated oxidation of isoprene in the presence of O2 and NO using the Laser Photolysis-Laser Induced Fluorescence (LP-LIF) technique. The photolysis of monodeuterated/non deuterated 2-iodo-2-methyl-but-3-en-1-ol results exclusively in the dominant OH-isoprene addition product, providing important insight into the oxidation mechanism. Based on kinetic analysis of OH cycling experiments we have determined the rate constant for O2 addition to the hydroxy alkyl radical to be (1.0±0.5) × 10^(-12) cm^(3) s^(-1) and we find a value of (8.05±2.3) × 10^(-12) cm^(3) s^(-1) for the overall reaction rate constant of the hydroxy peroxy radical with NO. We also report the first clear experimental evidence of the (E-) form of the δ-hydroxyalkoxy channel through isotopic labeling experiments and quantify its branching ratio to be 0.1±0.025. Since it corresponds to missing carbon balance in isoprene oxidation, we have been able to identify some of the missing carbon balance. Since our measured isomeric selective rate constants for the dominant outer channel in OH initiated isoprene chemistry are similar to the overall rate constants derived from non isomeric kinetics, we predict that the remaining outer addition channel will have similar reactivity. We have extended this study to the OH initiated oxidation of 1,3-butadiene. We have obtained isomeric selective rate constants on the dominant channel of the butadiene oxidation chemistry and measured the branching ratio for the δ-hydroxyalkoxy channel. These results on butadiene studies will be discussed.

  3. Recruitment of Yoruba families from Nigeria for genetic research: experience from a multisite keloid study

    PubMed Central

    2014-01-01

    Background More involvement of sub-Saharan African countries in biomedical studies, specifically in genetic research, is needed to advance individualized medicine that will benefit non-European populations. Missing infrastructure, cultural and religious beliefs as well as lack of understanding of research benefits can pose a challenge to recruitment. Here we describe recruitment efforts for a large genetic study requiring three-generation pedigrees within the Yoruba homelands of Nigeria. The aim of the study was to identify genes responsible for keloids, a wound healing disorder. We also discuss ethical and logistical considerations that we encountered in preparation for this research endeavor. Methods Protocols for this bi-national intercultural study were approved by the Institutional Review Board (IRB) in the US and the ethics committees of the Nigerian institutions for consideration of cultural differences. Principles of community based participatory research were employed throughout the recruitment process. Keloid patients (patient advisors), community leaders, kings/chiefs and medical directors were engaged to assist the research teams with recruitment strategies. Community meetings, church forums, and media outlets (study flyers, radio and TV announcements) were utilized to promote the study in Nigeria. Recruitment of research participants was conducted by trained staff from the local communities. Pedigree structures were re-analyzed on a regular basis as new family members were recruited and recruitment challenges were documented. Results Total recruitment surpassed 4200 study participants over a 7-year period including 79 families with complete three-generation pedigrees. In 9 families more than 20 family members participated, however, in 5 of these families, we encountered issues with pedigree structure as members from different branches presented inconsistent family histories. These issues were due to the traditional open family structure amongst the

  4. Immunotoxic effects of the color additive caramel color III: immune function studies in rats.

    PubMed

    Houben, G F; Penninks, A H; Seinen, W; Vos, J G; Van Loveren, H

    1993-01-01

    Administration of the color additive caramel color III (AC) may cause a reduction in total white blood cell counts in rats due to reduced lymphocyte counts. Beside lymphopenia, several other effects in rat have been described. The effects are caused by the imidazole derivative 2-acetyl-4(5)-(1,2,3,4-tetrahydroxybutyl)imidazole (THI) and occur in rats fed a diet low in vitamin B6. In the present paper, immune function studies on AC and THI with rats fed a diet low, but not deficient in vitamin B6 are presented and discussed. Rats were exposed to 0.4 or 4% AC or to 5.72 ppm THI in drinking water during and for 28 days prior to the start of immune function assays. Resistance to Trichinella spiralis was examined in an oral infection model and clearance of Listeria monocytogenes upon an intravenous infection was studied. In addition, natural cell-mediated cytotoxicity of splenic and nonadherent peritoneal cells and the antibody response to sheep red blood cells were studied. From the results it is concluded that exposure of rats to AC or THI influenced various immune function parameters. Thymus-dependent immunity was suppressed, while parameters of the nonspecific resistance were also affected, as shown by a decreased natural cell-mediated cytotoxicity in the spleen and an enhanced clearance of L. monocytogenes. PMID:8432426

  5. Improving wound care simulation with the addition of odor: a descriptive, quasi-experimental study.

    PubMed

    Roberson, Donna W; Neil, Janice A; Bryant, Elizabeth T

    2008-08-01

    Improving problem-solving skills and expertise in complex clinical care provision requires engaging students in the learning process--a challenging goal when clinical practicums and supervisors are limited. High-fidelity simulation has created many new opportunities for educating healthcare professionals. Because addressing malodorous wounds is a common problem that may be difficult to "teach," a descriptive, quasi-experimental simulation study was conducted. Following completion of a wound care simulation and Laerdal's Simulation Experience Evaluation Tool by 137 undergraduate nursing students, 50 control subjects were randomly selected and 49 volunteer students (experimental group) participated in a wound care simulation after one of three cheeses with a strong odor was added to simulate a malodorous wound. Compared to the control group, study group responses were significantly better (P <0.001) for eight of the 12 survey variables tested and indicated the addition of odor was beneficial in enhancing the perceived realism and value of the simulation. Students responded that the addition of odor in the simulation laboratory improved realism and they felt better prepared to handle malodorous wounds in a clinical setting. An unanticipated outcome was the enhanced feeling of involvement associated with paired care teams as opposed to working in larger groups. The results of this study indicate that wound care education outcomes improve when nursing students are able to practice using a multi-sensorial wound care simulation model. PMID:18716340

  6. Brain fiber architecture, genetics, and intelligence: a high angular resolution diffusion imaging (HARDI) study.

    PubMed

    Chiang, Ming-Chang; Barysheva, Marina; Lee, Agatha D; Madsen, Sarah; Klunder, Andrea D; Toga, Arthur W; Mcmahon, Katie L; de Zubicaray, Greig I; Meredith, Matthew; Wright, Margaret J; Srivastava, Anuj; Balov, Nikolay; Thompson, Paul M

    2008-01-01

    We developed an analysis pipeline enabling population studies of HARDI data, and applied it to map genetic influences on fiber architecture in 90 twin subjects. We applied tensor-driven 3D fluid registration to HARDI, resampling the spherical fiber orientation distribution functions (ODFs) in appropriate Riemannian manifolds, after ODF regularization and sharpening. Fitting structural equation models (SEM) from quantitative genetics, we evaluated genetic influences on the Jensen-Shannon divergence (JSD), a novel measure of fiber spatial coherence, and on the generalized fiber anisotropy (GFA) a measure of fiber integrity. With random-effects regression, we mapped regions where diffusion profiles were highly correlated with subjects' intelligence quotient (IQ). Fiber complexity was predominantly under genetic control, and higher in more highly anisotropic regions; the proportion of genetic versus environmental control varied spatially. Our methods show promise for discovering genes affecting fiber connectivity in the brain. PMID:18979850

  7. Internet solicitation of research subjects for genetic studies

    SciTech Connect

    Biesecker, L.G.; DeRenzo, E.G.

    1995-11-01

    Communication through electronic messages on the Internet has become a rapid and effective method for exchanging ideas and information in many disciplines. The Human Molecular Genetics network Diagnostics and Clinical Research Section (hum-molgen@nic.surfnet.nl) is now serving this function for the field of human molecular genetics. Our attention was drawn to the power and the pitfalls of this information exchange when we read a solicitation for research subjects by a Canadian medical student. The student was initiating a summer research project on an inherited disorder and requested information to determine the frequency of the disorder and to collect blood samples of affected patients. The student also requested samples of stored blood or DNA of affected persons. On other occasions, the hum-mol-gen service has also been used by clinicians to announce the availability of patients with a particular disorder (or their blood samples) who are interested in participating in research projects. Such uses of the Internet can serve to facilitate communication between researchers and clinicians and enhance clinical research. We believe, however, that some guidelines are necessary to protect human subjects. Investigators in the United States who are subject to U.S. Federal Government human subjects research regulations, or who are attached to an institution conducting such research, should consider some important issues before placing or responding to a request on the Internet. 1 ref.

  8. Genetics and antisocial behavior.

    PubMed

    Joseph, Jay

    2003-01-01

    This commentary article reviews a recent meta-analysis of genetic influences on antisocial behavior by Rhee and Waldman (2002). The authors combined the results of 51 twin and adoption studies and concluded that antisocial behavior has an important genetic component. However, twin and adoption studies contain several methodological flaws and are subject to the confounding influence of environmental factors. Therefore, Rhee and Waldman's conclusions in favor of genetic influences are not supported by the evidence. Two additional topics are Rhee and Waldman's incorrect description of the heritability concept and their failure to discuss several German criminal twin studies published during the Nazi era. PMID:15279006

  9. Genetic mouse models to study blood–brain barrier development and function

    PubMed Central

    2013-01-01

    The blood–brain barrier (BBB) is a complex physiological structure formed by the blood vessels of the central nervous system (CNS) that tightly regulates the movement of substances between the blood and the neural tissue. Recently, the generation and analysis of different genetic mouse models has allowed for greater understanding of BBB development, how the barrier is regulated during health, and its response to disease. Here we discuss: 1) Genetic mouse models that have been used to study the BBB, 2) Available mouse genetic tools that can aid in the study of the BBB, and 3) Potential tools that if generated could greatly aid in our understanding of the BBB. PMID:23305182

  10. A new method for studying population genetics of cyst nematodes based on Pool-Seq and genomewide allele frequency analysis.

    PubMed

    Mimee, Benjamin; Duceppe, Marc-Olivier; Véronneau, Pierre-Yves; Lafond-Lapalme, Joël; Jean, Martine; Belzile, François; Bélair, Guy

    2015-11-01

    Cyst nematodes are important agricultural pests responsible for billions of dollars of losses each year. Plant resistance is the most effective management tool, but it requires a close monitoring of population genetics. Current technologies for pathotyping and genotyping cyst nematodes are time-consuming, expensive and imprecise. In this study, we capitalized on the reproduction mode of cyst nematodes to develop a simple population genetic analysis pipeline based on genotyping-by-sequencing and Pool-Seq. This method yielded thousands of SNPs and allowed us to study the relationships between populations of different origins or pathotypes. Validation of the method on well-characterized populations also demonstrated that it was a powerful and accurate tool for population genetics. The genomewide allele frequencies of 23 populations of golden nematode, from nine countries and representing the five known pathotypes, were compared. A clear separation of the pathotypes and fine genetic relationships between and among global populations were obtained using this method. In addition to being powerful, this tool has proven to be very time- and cost-efficient and could be applied to other cyst nematode species. PMID:25846829

  11. Development and application of SINE multilocus and quantitative genetic markers to study oilseed rape (Brassica napus L.) crops.

    PubMed

    Allnutt, T R; Roper, K; Henry, C

    2008-01-23

    A genetic marker system based on the S1 Short Interspersed Elements (SINEs) in the important commercial crop, oilseed rape ( Brassica napus L.) has been developed. SINEs provided a successful multilocus, dominant marker system that was capable of clearly delineating winter- and spring-type crop varieties. Sixteen of 20 varieties tested showed unique profiles from the 17 polymorphic SINE markers generated. The 3' or 5' flank region of nine SINE markers were cloned, and DNA was sequenced. In addition, one putative pre-transposition SINE allele was cloned and sequenced. Two SINE flanking sequences were used to design real-time PCR assays. These quantitative SINE assays were applied to study the genetic structure of eight fields of oilseed rape crops. Studied fields were more genetically diverse than expected for the chosen loci (mean H T = 0.23). The spatial distribution of SINE marker frequencies was highly structured in some fields, suggesting locations of volunteer impurities within the crop. In one case, the assay identified a mislabeling of the crop variety. SINE markers were a useful tool for crop genetics, phylogenetics, variety identification, and purity analysis. The use and further application of quantitative, real-time PCR markers are discussed. PMID:18092752

  12. The genetic regulatory network centered on Pto-Wuschela and its targets involved in wood formation revealed by association studies

    PubMed Central

    Yang, Xiaohui; Wei, Zunzheng; Du, Qingzhang; Chen, Jinhui; Wang, Qingshi; Quan, Mingyang; Song, Yuepeng; Xie, Jianbo; Zhang, Deqiang

    2015-01-01

    Transcription factors (TFs) regulate gene expression and can strongly affect phenotypes. However, few studies have examined TF variants and TF interactions with their targets in plants. Here, we used genetic association in 435 unrelated individuals of Populus tomentosa to explore the variants in Pto-Wuschela and its targets to decipher the genetic regulatory network of Pto-Wuschela. Our bioinformatics and co-expression analysis identified 53 genes with the motif TCACGTGA as putative targets of Pto-Wuschela. Single-marker association analysis showed that Pto-Wuschela was associated with wood properties, which is in agreement with the observation that it has higher expression in stem vascular tissues in Populus. Also, SNPs in the 53 targets were associated with growth or wood properties under additive or dominance effects, suggesting these genes and Pto-Wuschela may act in the same genetic pathways that affect variation in these quantitative traits. Epistasis analysis indicated that 75.5% of these genes directly or indirectly interacted Pto-Wuschela, revealing the coordinated genetic regulatory network formed by Pto-Wuschela and its targets. Thus, our study provides an alternative method for dissection of the interactions between a TF and its targets, which will strength our understanding of the regulatory roles of TFs in complex traits in plants. PMID:26549216

  13. Genetic architecture of lipid traits changes over time and differs by race: Princeton Lipid Follow-up Study

    PubMed Central

    Woo, Jessica G.; Morrison, John A.; Stroop, Davis M.; Aronson Friedman, Lisa; Martin, Lisa J.

    2014-01-01

    Dyslipidemia is a major risk factor for CVD. Previous studies on lipid heritability have largely focused on white populations assessed after the obesity epidemic. Given secular trends and racial differences in lipid levels, this study explored whether lipid heritability is consistent across time and between races. African American and white nuclear families had fasting lipids measured in the 1970s and 22–30 years later. Heritability was estimated, and bivariate analyses between visits were conducted by race using variance components analysis. A total of 1,454 individuals (age 14.1/40.6 for offspring/parents at baseline; 39.6/66.5 at follow-up) in 373 families (286 white, 87 African American) were included. Lipid trait heritabilities were typically stronger during the 1970s than the 2000s. At baseline, additive genetic variation for LDL was significantly lower in African Americans than whites (P = 0.015). Shared genetic contribution to lipid variability over time was significant in both whites (all P < 0.0001) and African Americans (P ≤ 0.05 for total, LDL, and HDL cholesterol). African American families demonstrated shared environmental contributions to lipid variation over time (all P ≤ 0.05). Lower heritability, lower LDL genetic variance, and durable environmental effects across the obesity epidemic in African American families suggest race-specific approaches are needed to clarify the genetic etiology of lipids. PMID:24859784

  14. A molecular-genetic approach to studying source-sink interactions in Arabidopsis thalian. Final report

    SciTech Connect

    Gibson, S. I.

    2000-06-01

    This is a final report describing the results of the research funded by the DOE Energy Biosciences Program grant entitled ''A Molecular-Genetic Approach to Studying Source-Sink Interactions in Arabidiopsis thaliana''.

  15. Genetic Association Studies in Uterine Fibroids: Risk Alleles Presage the Path to Personalized Therapies.

    PubMed

    Gallagher, C Scott; Morton, Cynthia C

    2016-07-01

    Uterine leiomyoma (UL) is the most common tumor of the female reproductive system. Epidemiological analyses, including familial aggregation, twin studies, and racial discrepancies in disease prevalence and morbidity, indicated genetic factors influence risk for developing UL. Genome-wide association studies (GWASs) are a powerful method for identifying genetic variants that are associated with elevated risk for a common, complex disease. To date, three genome-wide scans for UL have been performed: a GWAS in Japanese women, a genome-wide linkage and association study in women of European decent, and an admixture-based analysis in African American women. Results from each of the three genome-wide scans performed have had varying success in identifying unique loci associated with predisposition to developing UL. Here, we address the evidence for a genetic basis for UL risk, discuss genetic association studies and their results, and identify challenges and future directions for UL GWAS analyses. PMID:27513025

  16. A water soluble additive to suppress respirable dust from concrete-cutting chainsaws: a case study.

    PubMed

    Summers, Michael P; Parmigiani, John P

    2015-01-01

    Respirable dust is of particular concern in the construction industry because it contains crystalline silica. Respirable forms of silica are a severe health threat because they heighten the risk of numerous respirable diseases. Concrete cutting, a common work practice in the construction industry, is a major contributor to dust generation. No studies have been found that focus on the dust suppression of concrete-cutting chainsaws, presumably because, during normal operation water is supplied continuously and copiously to the dust generation points. However, there is a desire to better understand dust creation at low water flow rates. In this case study, a water-soluble surfactant additive was used in the chainsaw's water supply. Cutting was performed on a free-standing concrete wall in a covered outdoor lab with a hand-held, gas-powered, concrete-cutting chainsaw. Air was sampled at the operator's lapel, and around the concrete wall to simulate nearby personnel. Two additive concentrations were tested (2.0% and 0.2%), across a range of fluid flow rates (0.38-3.8 Lpm [0.1-1.0 gpm] at 0.38 Lpm [0.1 gpm] increments). Results indicate that when a lower concentration of additive is used exposure levels increase. However, all exposure levels, once adjusted for 3 hours of continuous cutting in an 8-hour work shift, are below the Occupational Safety and Health Administration (OSHA) permissible exposure limit (PEL) of 5 mg/m(3). Estimates were made using trend lines to predict the fluid flow rates that would cause respirable dust exposure to exceed both the OSHA PEL and the American Conference of Governmental Industrial Hygienists (ACGIH®) threshold limit value (TLV). PMID:25714034

  17. Review of the Diabetes Heart Study (DHS) family of studies: a comprehensively examined sample for genetic and epidemiological studies of type 2 diabetes and its complications.

    PubMed

    Bowden, Donald W; Cox, Amanda J; Freedman, Barry I; Hugenschimdt, Christina E; Wagenknecht, Lynne E; Herrington, David; Agarwal, Subhashish; Register, Thomas C; Maldjian, Joseph A; Ng, Maggie C-Y; Hsu, Fang-Chi; Langefeld, Carl D; Williamson, Jeff D; Carr, J Jeffrey

    2010-01-01

    The Diabetes Heart Study (DHS) is a genetic and epidemiological study of 1,443 European American and African American participants from 564 families with multiple cases of type 2 diabetes. Initially, participants were comprehensively examined for measures of subclinical cardiovascular disease (CVD) including computed tomography measurement of vascular calcified plaque, ultrasound imaging of carotid artery wall thickness, and electrocardiographic intervals. Subsequent studies have investigated the relationship between bone mineral density and vascular calcification, measures of adiposity, and biomarkers. Ongoing studies are carrying out an extensive evaluation of cerebrovascular disease using magnetic resonance imaging and cognitive assessment. A second, parallel study, the African American DHS, has expanded the sample of African Americans to investigate marked racial differences in subclinical CVD between European Americans and African Americans. Studies in development will evaluate the impact of social stress during the lifecourse on CVD risk, and the prevalence of gastroparesis in this diabetes enriched sample. In addition, the ongoing high mortality rate in DHS participants provides novel insights into the increased risks for type 2 diabetes affected individuals. A comprehensive genetic analysis of the sample is underway using the genome-wide association study (GWAS) approach. Data from this GWAS survey will complement prior family-based linkage data in the analysis of genetic contributors to the wide range of traits in the sample. To our knowledge the DHS family of studies has created the most comprehensively examined sample of individuals with type 2 diabetes yet available, and represents a unique resource for the study people with type 2 diabetes. The aim of this review is to provide a collective overview of the major results from the DHS family of studies, and relate them to the larger body of biomedical investigations of diabetes and its complications. PMID

  18. Genetic and histological studies on the delayed systemic movement of Tobacco Mosaic Virus in Arabidopsis thaliana

    PubMed Central

    Serrano, Carolina; González-Cruz, Javiera; Jauregui, Francisca; Medina, Consuelo; Mancilla, Pablo; Matus, José Tomás; Arce-Johnson, Patricio

    2008-01-01

    Background Viral infections and their spread throughout a plant require numerous interactions between the host and the virus. While new functions of viral proteins involved in these processes have been revealed, current knowledge of host factors involved in the spread of a viral infection is still insufficient. In Arabidopsis thaliana, different ecotypes present varying susceptibilities to Tobacco mosaic virus strain U1 (TMV-U1). The rate of TMV-U1 systemic movement is delayed in ecotype Col-0 when compared with other 13 ecotypes. We followed viral movement through vascular tissue in Col-0 plants by electronic microscopy studies. In addition, the delay in systemic movement of TMV-U1 was genetically studied. Results TMV-U1 reaches apical leaves only after 18 days post rosette inoculation (dpi) in Col-0, whereas it is detected at 9 dpi in the Uk-4 ecotype. Genetic crosses between Col-0 and Uk-4 ecotypes, followed by analysis of viral movement in F1 and F2 populations, revealed that this delayed movement correlates with a recessive, monogenic and nuclear locus. The use of selected polymorphic markers showed that this locus, denoted DSTM1 (Delayed Systemic Tobamovirus Movement 1), is positioned on the large arm of chromosome II. Electron microscopy studies following the virion's route in stems of Col-0 infected plants showed the presence of curved structures, instead of the typical rigid rods of TMV-U1. This was not observed in the case of TMV-U1 infection in Uk-4, where the observed virions have the typical rigid rod morphology. Conclusion The presence of defectively assembled virions observed by electron microscopy in vascular tissue of Col-0 infected plants correlates with a recessive delayed systemic movement trait of TMV-U1 in this ecotype. PMID:18817581

  19. Augmenting a Waste Glass Mixture Experiment Study with Additional Glass Components and Experimental Runs

    SciTech Connect

    Piepel, Gregory F. ); Cooley, Scott K. ); Peeler, David K.; Vienna, John D. ); Edwards, Tommy B.

    2002-01-01

    A glass composition variation study (CVS) for high-level waste (HLW) stored in Idaho is being statistically designed and performed in phases over several years. The purpose of the CVS is to investigate and model how HLW-glass properties depend on glass composition. The resulting glass property-composition models will be used to develop desirable glass formulations and for other purposes. Phases 1 and 2 of the CVS have been completed and are briefly described. This paper focuses on the CVS Phase 3 experimental design, which was chosen to augment the Phase 1 and 2 data with additional data points, as well as to account for additional glass components not studied in Phases 1 and/or 2. In total, 16 glass components were varied in the Phase 3 experimental design. The paper describes how these Phase 3 experimental design augmentation challenges were addressed using the previous data, preliminary property-composition models, and statistical mixture experiment and optimal experimental design methods and software.

  20. Genetics of Coronary Artery Disease in Taiwan: A Cardiometabochip Study by the Taichi Consortium

    PubMed Central

    Juang, Jyh-Ming; Guo, Xiuqing; Wang, Tzung-Dau; Kim, Eric T.; Lee, Wen-Jane; Absher, Devin; Chiu, Yen-Feng; Hsu, Chih-Cheng; Chuang, Lee-Ming; Quertermous, Thomas; Hsiung, Chao A.; Rotter, Jerome I.; Sheu, Wayne H.-H.; Chen, Yii-Der Ida; Taylor, Kent D.

    2016-01-01

    By means of a combination of genome-wide and follow-up studies, recent large-scale association studies of populations of European descent have now identified over 46 loci associated with coronary artery disease (CAD). As part of the TAICHI Consortium, we have collected and genotyped 8556 subjects from Taiwan, comprising 5423 controls and 3133 cases with coronary artery disease, for 9087 CAD SNPs using the CardioMetaboChip. We applied penalized logistic regression to ascertain the top SNPs that contribute together to CAD susceptibility in Taiwan. We observed that the 9p21 locus contributes to CAD at the level of genome-wide significance (rs1537372, with the presence of C, the major allele, the effect estimate is -0.216, standard error 0.033, p value 5.8x10-10). In contrast to a previous report, we propose that the 9p21 locus is a single genetic contribution to CAD in Taiwan because: 1) the penalized logistic regression and the follow-up conditional analysis suggested that rs1537372 accounts for all of the CAD association in 9p21, and 2) the high linkage disequilibrium observed for all associated SNPs in 9p21. We also observed evidence for the following loci at a false discovery rate >5%: SH2B3, ADAMTS7, PHACTR1, GGCX, HTRA1, COL4A1, and LARP6-LRRC49. We also took advantage of the fact that penalized methods are an efficient approach to search for gene-by-gene interactions, and observed that two-way interactions between the PHACTR1 and ADAMTS7 loci and between the SH2B3 and COL4A1 loci contribute to CAD risk. Both the similarities and differences between the significance of these loci when compared with significance of loci in studies of populations of European descent underscore the fact that further genetic association of studies in additional populations will provide clues to identify the genetic architecture of CAD across all populations worldwide. PMID:26982883

  1. Role of sulfite additives in wine induced asthma: single dose and cumulative dose studies

    PubMed Central

    Vally, H; Thompson, P

    2001-01-01

    BACKGROUND—Wine appears to be a significant trigger for asthma. Although sulfite additives have been implicated as a major cause of wine induced asthma, direct evidence is limited. Two studies were undertaken to assess sulfite reactivity in wine sensitive asthmatics. The first study assessed sensitivity to sulfites in wine using a single dose sulfited wine challenge protocol followed by a double blind, placebo controlled challenge. In the second study a cumulative dose sulfited wine challenge protocol was employed to establish if wine sensitive asthmatics as a group have an increased sensitivity to sulfites.
METHODS—In study 1, 24 asthmatic patients with a strong history of wine induced asthma were screened. Subjects showing positive responses to single blind high sulfite (300 ppm) wine challenge were rechallenged on separate days in a double blind, placebo controlled fashion with wines of varying sulfite levels to characterise their responses to these drinks. In study 2, wine sensitive asthmatic patients (n=12) and control asthmatics (n=6) were challenged cumulatively with wine containing increasing concentrations of sulfite in order to characterise further their sensitivity to sulfites in wine.
RESULTS—Four of the 24 self-reporting wine sensitive asthmatic patients were found to respond to sulfite additives in wine when challenged in a single dose fashion (study 1). In the double blind dose-response study all four had a significant fall in forced expiratory volume in one second (FEV1) (>15% from baseline) following exposure to wine containing 300 ppm sulfite, but did not respond to wines containing 20, 75 or 150 ppm sulfite. Responses were maximal at 5 minutes (mean (SD) maximal decline in FEV1 28.7 (13)%) and took 15-60 minutes to return to baseline levels. In the cumulative dose-response study (study 2) no significant difference was observed in any of the lung function parameters measured (FEV1, peak expiratory flow (PEF), mid phase forced expiratory

  2. Characterization studies on the additives mixed L-arginine phosphate monohydrate (LAP) crystals

    NASA Astrophysics Data System (ADS)

    Haja Hameed, A. S.; Karthikeyan, C.; Ravi, G.; Rohani, S.

    2011-04-01

    L-arginine phosphate monohydrate (LAP), potassium thiocyanate (KSCN) mixed LAP (LAP:KSCN) and sodium sulfite (Na 2SO 3) mixed LAP (LAP:Na 2SO 3) single crystals were grown by slow cooling technique. The effect of microbial contamination and coloration on the growth solutions was studied. The crystalline powders of the grown crystals were examined by X-ray diffraction and the lattice parameters of the crystals were estimated. From the FTIR spectroscopic analysis, various functional group frequencies associated with the crystals were assigned. Vickers microhardness studies were done on {1 0 0} faces for pure and additives mixed LAP crystals. From the preliminary surface second harmonic generation (SHG) results, it was found that the SHG intensity at (1 0 0) face of LAP:KSCN crystal was much stronger than that of pure LAP.

  3. The guanidine and maleic acid (1:1) complex. The additional theoretical and experimental studies

    NASA Astrophysics Data System (ADS)

    Drozd, Marek; Dudzic, Damian

    2012-04-01

    On the basis of experimental literature data the theoretical studies for guanidinium and maleic acid complex with using DFT method are performed. In these studies the experimental X-ray data for two different forms of investigated crystal were used. During the geometry optimization process one equilibrium structure was found, only. According to this result the infrared spectrum for one theoretical molecule was calculated. On the basis of potential energy distribution (PED) analysis the clear-cut assignments of observed bands were performed. For the calculated molecule with energy minimum the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) were obtained and graphically illustrated. The energy difference (GAP) between HOMO and LUMO was analyzed. Additionally, the nonlinear properties of this molecule were calculated. The α and β (first and second order) hyperpolarizability values are obtained. On the basis of these results the title crystal was classified as new second order NLO generator.

  4. Prazosin addition to fluvoxamine: A preclinical study and open clinical trial in OCD.

    PubMed

    Feenstra, Matthijs G P; Klompmakers, André; Figee, Martijn; Fluitman, Sjoerd; Vulink, Nienke; Westenberg, Herman G M; Denys, Damiaan

    2016-02-01

    The efficacy of selective serotonin reuptake inhibitors (SRIs) in psychiatric disorders may be "augmented" through the addition of atypical antipsychotic drugs. A synergistic increase in dopamine (DA) release in the prefrontal cortex has been suggested to underlie this augmentation effect, though the mechanism of action is not clear yet. We used in vivo microdialysis in rats to study DA release following the administration of combinations of fluvoxamine (10 mg/kg) and quetiapine (10 mg/kg) with various monoamine-related drugs. The results confirmed that the selective 5-HT1A antagonist WAY-100635 (0.05 mg/kg) partially blocked the fluvoxamine-quetiapine synergistic effect (maximum DA increase dropped from 325% to 214%). A novel finding is that the α1-adrenergic blocker prazosin (1 mg/kg), combined with fluvoxamine, partially mimicked the effect of augmentation (maximum DA increase 205%; area-under-the-curve 163%). As this suggested that prazosin augmentation might be tested in a clinical study, we performed an open clinical trial of prazosin 20 mg addition to SRI in therapy-resistant patients with obsessive-compulsive disorder applying for neurosurgery. A small, non-significant reduction in Yale Brown Obsessive Compulsive Scale (Y-BOCS) scores was observed in 10 patients and one patient was classified as a responder with a reduction in Y-BOCS scores of more than 25%. We suggest that future clinical studies augmenting SRIs with an α1-adrenergic blocker in less treatment resistant cases should be considered. The clinical trial "Prazosin in combination with a serotonin reuptake inhibitor for patients with Obsessive Compulsive disorder: an open label study" was registered at 24/05/2011 under trial number ISRCTN61562706: http://www.controlled-trials.com/ISRCTN61562706. PMID:26712326

  5. Genome Sequence of EU-Unauthorized Genetically Modified Bacillus subtilis Strain 2014-3557 Overproducing Riboflavin, Isolated from a Vitamin B2 80% Feed Additive

    PubMed Central

    Barbau-Piednoir, Elodie; De Keersmaecker, Sigrid C. J.; Wuyts, Véronique; Gau, Céline; Pirovano, Walter; Costessi, Adalberto; Philipp, Patrick

    2015-01-01

    This paper announces the genome sequence and annotation of the genetically modified (GM) Bacillus subtilis strain 2014-3557 overproducing riboflavin (vitamin B2). This GM-strain is unauthorized in the European Union. Nevertheless, it has been isolated from a lot of vitamin B2 (riboflavin) 80% feed grade imported to Europe from China. PMID:25858836

  6. Effect of sociocultural cleavage on genetic differentiation: a study from North India.

    PubMed

    Khan, Faisal; Pandey, Atul Kumar; Borkar, Meenal; Tripathi, Manorma; Talwar, Sudha; Bisen, P S; Agrawal, Suraksha

    2008-06-01

    Indian populations possess an exclusive genetic profile primarily due to the many migratory events, which caused an extensive range of genetic diversity, and also due to stringent and austere sociocultural barriers that structure these populations into different endogamous groups. In the present study we attempt to explore the genetic relationships between various endogamous North Indian populations and to determine the effect of stringent social regulations on their gene pool. Twenty STR markers were genotyped in 1,800 random North Indians from 9 endogamous populations belonging to upper-caste and middle-caste Hindus and Muslims. All nine populations had high allelic diversity (176 alleles) and average observed heterozygosity (0.742 +/- 0.06), suggesting strong intrapopulation diversity. The average F(ST) value over all loci was as low as 0.0084. However, within-group F(ST) and genetic distance analysis showed that populations of the same group were genetically closer to each other. The genetic distance of Muslims from middle castes (F(ST) = 0.0090; DA = 0.0266) was significantly higher than that of Muslims from upper castes (F(ST) = 0.0050; DA = 0.0148). Phylogenetic trees (neighbor-joining and maximum-likelihood) show the basal cluster pattern of three clusters corresponding to Muslims, upper-caste, and middle-caste populations, with Muslims clustered with upper-caste populations. Based on the results, we conclude that the extensive gene flow through a series of migrations and invasions has created an enormous amount of genetic diversity. The interpopulation differences are minimal but have a definite pattern, in which populations of different socioreligious groups have more genetic similarity within the same group and are genetically more distant from populations of other groups. Finally, North Indian Muslims show a differential genetic relationship with upper- and middle-caste populations. PMID:19130797

  7. Impact of contacting study authors to obtain additional data for systematic reviews: diagnostic accuracy studies for hepatic fibrosis

    PubMed Central

    2014-01-01

    Background Seventeen of 172 included studies in a recent systematic review of blood tests for hepatic fibrosis or cirrhosis reported diagnostic accuracy results discordant from 2 × 2 tables, and 60 studies reported inadequate data to construct 2 × 2 tables. This study explores the yield of contacting authors of diagnostic accuracy studies and impact on the systematic review findings. Methods Sixty-six corresponding authors were sent letters requesting additional information or clarification of data from 77 studies. Data received from the authors were synthesized with data included in the previous review, and diagnostic accuracy sensitivities, specificities, and positive and likelihood ratios were recalculated. Results Of the 66 authors, 68% were successfully contacted and 42% provided additional data for 29 out of 77 studies (38%). All authors who provided data at all did so by the third emailed request (ten authors provided data after one request). Authors of more recent studies were more likely to be located and provide data compared to authors of older studies. The effects of requests for additional data on the conclusions regarding the utility of blood tests to identify patients with clinically significant fibrosis or cirrhosis were generally small for ten out of 12 tests. Additional data resulted in reclassification (using median likelihood ratio estimates) from less useful to moderately useful or vice versa for the remaining two blood tests and enabled the calculation of an estimate for a third blood test for which previously the data had been insufficient to do so. We did not identify a clear pattern for the directional impact of additional data on estimates of diagnostic accuracy. Conclusions We successfully contacted and received results from 42% of authors who provided data for 38% of included studies. Contacting authors of studies evaluating the diagnostic accuracy of serum biomarkers for hepatic fibrosis and cirrhosis in hepatitis C patients

  8. Genetic factors in evolution of sleep length--a longitudinal twin study in Finnish adults.

    PubMed

    Hublin, Christer; Partinen, Markku; Koskenvuo, Markku; Kaprio, Jaakko

    2013-10-01

    Genetic factors affect many aspects of sleep, such as sleep length. We investigated the contribution of genetic factors to stability and change of sleep length among adults over a 15-year period. In this representative follow-up study we used the Finnish Twin Cohort as the study population. Questionnaire surveys were performed in 1975 (response rate 89%, 11,041 twin pairs; age ≥18 years), 1981 (84%, 9323; ≥24 years) and 1990 (77%, 4507; 33-60 years). Sleep was categorized as short (<7 h), average or long (>8 h). Pairwise similarity in monozygotic and dizygotic pairs was examined at each survey by age group and sex. Quantitative genetic modelling was used to estimate cross-sectional and longitudinal genetic effects. The proportion of variance in sleep length at one point in time that was accounted for by genetic effects was very stable over the study period, being 0.31 in 1975, 0.32 in 1981 and 0.30 in 1990. Longitudinal genetic modelling indicated that the correlations of genetic effects between the three measurement points were high: 0.85 between 1975 and 1981; 0.93 between 1981 and 1990; and 0.76 between 1975 and 1990. Despite a high contribution of environmental effects, their correlations over time were modest: 0.31 between 1975 and 1981; 0.33 between 1981 and 1990; and 0.18 between 1975 and 1990. In conclusion, genetic factors have a modest but stable effect on the evolution of sleep length over a long time span in adults. Multiple measures are a more robust basis for genetic analyses than a single cross-sectional measure. PMID:23509990

  9. Detecting Genetic Isolation in Human Populations: A Study of European Language Minorities

    PubMed Central

    Capocasa, Marco; Battaggia, Cinzia; Anagnostou, Paolo; Montinaro, Francesco; Boschi, Ilaria; Ferri, Gianmarco; Alù, Milena; Coia, Valentina; Crivellaro, Federica; Bisol, Giovanni Destro

    2013-01-01

    The identification of isolation signatures is fundamental to better understand the genetic structure of human populations and to test the relations between cultural factors and genetic variation. However, with current approaches, it is not possible to distinguish between the consequences of long-term isolation and the effects of reduced sample size, selection and differential gene flow. To overcome these limitations, we have integrated the analysis of classical genetic diversity measures with a Bayesian method to estimate gene flow and have carried out simulations based on the coalescent. Combining these approaches, we first tested whether the relatively short history of cultural and geographical isolation of four “linguistic islands” of the Eastern Alps (Lessinia, Sauris, Sappada and Timau) had left detectable signatures in their genetic structure. We then compared our findings to previous studies of European population isolates. Finally, we explored the importance of demographic and cultural factors in shaping genetic diversity among the groups under study. A combination of small initial effective size and continued genetic isolation from surrounding populations seems to provide a coherent explanation for the diversity observed among Sauris, Sappada and Timau, which was found to be substantially greater than in other groups of European isolated populations. Simulations of micro-evolutionary scenarios indicate that ethnicity might have been important in increasing genetic diversity among these culturally related and spatially close populations. PMID:23418562

  10. A combined toxicity study of zinc oxide nanoparticles and vitamin C in food additives

    NASA Astrophysics Data System (ADS)

    Wang, Yanli; Yuan, Lulu; Yao, Chenjie; Ding, Lin; Li, Chenchen; Fang, Jie; Sui, Keke; Liu, Yuanfang; Wu, Minghong

    2014-11-01

    At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the cytotoxicity significantly compared with that of the ZnO only NPs. When the cells were exposed to ZnO NPs at a concentration less than 15 mg L-1, or to Vc at a concentration less than 300 mg L-1, there was no significant cytotoxicity, both in the case of gastric epithelial cell line (GES-1) and neural stem cells (NSCs). However, when 15 mg L-1 of ZnO NPs and 300 mg L-1 of Vc were introduced to cells together, the cell viability decreased sharply indicating significant cytotoxicity. Moreover, the significant increase in toxicity was also shown in the in vivo experiments. The dose of the ZnO NPs and Vc used in the in vivo study was calculated according to the state of food and nutrition enhancer standard. After repeated oral exposure to ZnO NPs plus Vc, the injury of the liver and kidneys in mice has been indicated by the change of these indices. These findings demonstrate that the synergistic toxicity presented in a complex system is essential for the toxicological evaluation and safety assessment of nanofood.At present, safety evaluation standards for nanofood additives are made based on the toxic effects of a single additive. Since the size, surface properties and chemical nature influence the toxicity of nanomaterials, the toxicity may have dramatically changed when nanomaterials are used as food additives in a complex system. Herein, we investigated the combined toxicity of zinc oxide nanoparticles (ZnO NPs) and vitamin C (Vc, ascorbic acid). The results showed that Vc increased the

  11. A study of pyrazines in cigarettes and how additives might be used to enhance tobacco addiction

    PubMed Central

    Alpert, Hillel R; Agaku, Israel T; Connolly, Gregory N

    2016-01-01

    Background Nicotine is known as the drug that is responsible for the addicted behaviour of tobacco users, but it has poor reinforcing effects when administered alone. Tobacco product design features enhance abuse liability by (A) optimising the dynamic delivery of nicotine to central nervous system receptors, and affecting smokers’ withdrawal symptoms, mood and behaviour; and (B) effecting conditioned learning, through sensory cues, including aroma, touch and visual stimulation, to create perceptions of pending nicotine reward. This study examines the use of additives called ‘pyrazines’, which may enhance abuse potential, their introduction in ‘lights’ and subsequently in the highly market successful Marlboro Lights (Gold) cigarettes and eventually many major brands. Methods We conducted internal tobacco industry research using online databases in conjunction with published scientific literature research, based on an iterative feedback process. Results Tobacco manufacturers developed the use of a range of compounds, including pyrazines, in order to enhance ‘light’ cigarette products’ acceptance and sales. Pyrazines with chemosensory and pharmacological effects were incorporated in the first ‘full-flavour, low-tar’ product achieving high market success. Such additives may enhance dependence by helping to optimise nicotine delivery and dosing and through cueing and learned behaviour. Conclusions Cigarette additives and ingredients with chemosensory effects that promote addiction by acting synergistically with nicotine, increasing product appeal, easing smoking initiation, discouraging cessation or promoting relapse should be regulated by the US Food and Drug Administration. Current models of tobacco abuse liability could be revised to include more explicit roles with regard to non-nicotine constituents that enhance abuse potential. PMID:26063608

  12. Additional follow-up telephone counselling and initial smoking relapse: a longitudinal, controlled study

    PubMed Central

    Wu, Lei; He, Yao; Jiang, Bin; Zuo, Fang; Liu, Qinghui; Zhang, Li; Zhou, Changxi

    2016-01-01

    Objectives Smoking cessation services can help smokers to quit; however, many smoking relapse cases occur over time. Initial relapse prevention should play an important role in achieving the goal of long-term smoking cessation. Several studies have focused on the effect of extended telephone support in relapse prevention, but the conclusions remain conflicting. Design and setting From October 2008 to August 2013, a longitudinal, controlled study was performed in a large general hospital of Beijing. Participants The smokers who sought treatment at our smoking cessation clinic were non-randomised and divided into 2 groups: face-to-face individual counselling group (FC group), and face-to-face individual counselling plus telephone follow-up counselling group (FCF group). No pharmacotherapy was offered. Outcomes The timing of initial smoking relapse was compared between FC and FCF groups. Predictors of initial relapse were investigated during the first 180 days, using the Cox proportional hazards model. Results Of 547 eligible male smokers who volunteered to participate, 457 participants (117 in FC group and 340 in FCF group) achieved at least 24 h abstinence. The majority of the lapse episodes occurred during the first 2 weeks after the quit date. Smokers who did not receive the follow-up telephone counselling (FC group) tended to relapse to smoking earlier than those smokers who received the additional follow-up telephone counselling (FCF group), and the log-rank test was statistically significant (p=0.003). A Cox regression model showed that, in the FCF group, being married, and having a lower Fagerström test score, normal body mass index and doctor-diagnosed tobacco-related chronic diseases, were significantly independent protective predictors of smoking relapse. Conclusions Within the limitations of this study, it can be concluded that additional follow-up telephone counselling might be an effective strategy in preventing relapse. Further research is still

  13. A Mechanistic Study of Halogen Addition and Photoelimination from π-Conjugated Tellurophenes.

    PubMed

    Carrera, Elisa I; Lanterna, Anabel E; Lough, Alan J; Scaiano, Juan C; Seferos, Dwight S

    2016-03-01

    The ability to drive reactivity using visible light is of importance for many disciplines of chemistry and has significant implications for sustainable chemistry. Identifying photochemically active compounds and understanding photochemical mechanisms is important for the development of useful materials for synthesis and catalysis. Here we report a series of photoactive diphenyltellurophene compounds bearing electron-withdrawing and electron-donating substituents synthesized by alkyne coupling/ring closing or palladium-catalyzed ipso-arylation chemistry. The redox chemistry of these compounds was studied with respect to oxidative addition and photoelimination of bromine, which is of importance for energy storage reactions involving X2. The oxidative addition reaction mechanism was studied using density functional theory, the results of which support a three-step mechanism involving the formation of an initial η(1) association complex, a monobrominated intermediate, and finally the dibrominated product. All of the tellurophene derivatives undergo photoreduction using 430, 447, or 617 nm light depending on the absorption properties of the compound. Compounds bearing electron-withdrawing substituents have the highest photochemical quantum efficiencies in the presence of an alkene trap, with efficiencies of up to 42.4% for a pentafluorophenyl-functionalized tellurophene. The photoelimination reaction was studied in detail through bromine trapping experiments and laser flash photolysis, and a mechanism is proposed. The photoreaction, which occurs by release of bromine radicals, is competitive with intersystem crossing to the triplet state of the brominated species, as evidenced by the formation of singlet oxygen. These findings should be useful for the design of new photochemically active compounds supported by main-group elements. PMID:26853739

  14. Rhoptry protein 47 gene sequence: A potential novel genetic marker for population genetic studies of Toxoplasma gondii.

    PubMed

    Wang, Jin-Lei; Li, Ting-Ting; Li, Zhong-Yuan; Huang, Si-Yang; Ning, Hong-Rui; Zhu, Xing-Quan

    2015-07-01

    Toxoplasma gondii, an obligate intracellular parasite, is able to infect many animal species and humans, and can cause toxoplasmosis of the host. In this study, we examined sequence variation in rhoptry protein 47 (ROP47) gene among T. gondii isolates originating from different hosts and geographical regions. The entire genome region of the ROP47 gene was amplified and sequenced, and phylogenetic relationship was reconstructed using maximum parsimony (MP), maximum likelihood (ML) and neighbor-joining (NJ), based on the ROP47 gene sequences. The results of sequence alignments showed that all ROP47 gene sequences were 396 bp in length. There were 19 variable nucleotide positions in the coding region, resulted in 16 amino acid substitutions (12.21%) among all examined T. gondii strains and the existence of polymorphic restriction sites for endonucleases SacI and AflIII, allowing the differentiation of the three major clonal lineage types I, II and III by PCR-RFLP. Phylogenetic analysis of ROP47 gene sequences showed that three major clonal lineage types I, II and III were clustered differently, consistent with PCR-RFLP results. These results suggest that ROP47 gene sequence may represent a potential novel genetic marker for population genetic studies of T. gondii isolates. PMID:25862398

  15. A U-Statistic-based random Forest approach for genetic association study.

    PubMed

    Li, Ming; Peng, Ruo-Sin; Wei, Changshuai; Lu, Qing

    2012-01-01

    Variations in complex traits are influenced by multiple genetic variants, environmental risk factors, and their interactions. Though substantial progress has been made in identifying single genetic variants associated with complex traits, detecting the gene-gene and gene-environment interactions remains a great challenge. When a large number of genetic variants and environmental risk factors are involved, searching for interactions is limited to pair-wise interactions due to the exponentially increased feature space and computational intensity. Alternatively, recursive partitioning approaches, such as random forests, have gained popularity in high-dimensional genetic association studies. In this article, we propose a U-Statistic-based random forest approach, referred to as Forest U-Test, for genetic association studies with quantitative traits. Through simulation studies, we showed that the Forest U-Test outperformed exiting methods. The proposed method was also applied to study Cannabis Dependence (CD), using three independent datasets from the Study of Addiction: Genetics and Environment. A significant joint association was detected with an empirical p-value less than 0.001. The finding was also replicated in two independent datasets with p-values of 5.93e-19 and 4.70e-17, respectively. PMID:22652671

  16. Genome-Wide Association Studies: Progress in Identifying Genetic Biomarkers in Common, Complex Diseases

    PubMed Central

    Kingsmore, Stephen F.; Lindquist, Ingrid E.; Mudge, Joann; Beavis, William D.

    2007-01-01

    Novel, comprehensive approaches for biomarker discovery and validation are urgently needed. One particular area of methodologic need is for discovery of novel genetic biomarkers in complex diseases and traits. Here, we review recent successes in the use of genome wide association (GWA) approaches to identify genetic biomarkers in common human diseases and traits. Such studies are yielding initial insights into the allelic architecture of complex traits. In general, it appears that complex diseases are associated with many common polymorphisms, implying profound genetic heterogeneity between affected individuals. PMID:19662211

  17. Genetic association study of systemic lupus erythematosus and disease subphenotypes in European populations.

    PubMed

    Ruiz-Larrañaga, Otsanda; Migliorini, Paola; Uribarri, Maria; Czirják, László; Alcaro, Maria C; Del Amo, Jokin; Iriondo, Mikel; Manzano, Carmen; Escorza-Treviño, Sergio; Estonba, Andone

    2016-05-01

    Epidemiological studies suggest a strong contribution of genetic factors in the pathogenesis of systemic lupus erythematosus (SLE). In the last decades, many risk loci have been identified in several genetic association studies following both candidate gene and genome-wide approaches. The present work was conducted by GAPAID (Genes And Proteins for AutoImmunity Diagnostics) consortium with a dual aim: to replicate the association of several previously reported SLE susceptibility loci in an independent European sample and to explore their relation with some disease subphenotypes. A total of 48 single nucleotide polymorphisms (SNP) from 40 associated loci were typed in a cohort of 208 SLE patients and 152 controls from Rheumatology Units of the University Hospital of Pisa (Italy) and University of Pécs Medical Center (Hungary). Regression analyses were performed to detect disease susceptibility loci and to identify genes affecting specific disease manifestations (renal, neurological, or skin involvement; arthritis; secondary Sjögren syndrome; and secondary antiphospholipid syndrome). Association of previously described risk alleles from HLA locus has been replicated, while IRF5, BLK, ITGAM, and IRF8 loci have been found to be consistent with previous published results. In addition, two new subphenotype-specific associations have been detected: SNP rs5754217 (UBE2L3) with skin involvement and rs3093030 (ICAM1-ICAM4-ICAM5) with hematological disorders. Overall, results from GAPAID project are consistent with previously established associations for HLA, IRF5, BLK, ITGAM, and IRF8 SLE susceptibility loci and report for the first time two subphenotype-specific associations. PMID:27021335

  18. Study of mandible reconstruction using a fibula flap with application of additive manufacturing technology

    PubMed Central

    2014-01-01

    Background This study aimed to establish surgical guiding techniques for completing mandible lesion resection and reconstruction of the mandible defect area with fibula sections in one surgery by applying additive manufacturing technology, which can reduce the surgical duration and enhance the surgical accuracy and success rate. Methods A computer assisted mandible reconstruction planning (CAMRP) program was used to calculate the optimal cutting length and number of fibula pieces and design the fixtures for mandible cutting, registration, and arrangement of the fibula segments. The mandible cutting and registering fixtures were then generated using an additive manufacturing system. The CAMRP calculated the optimal fibula cutting length and number of segments based on the location and length of the defective portion of the mandible. The mandible cutting jig was generated according to the boundary surface of the lesion resection on the mandible STL model. The fibular cutting fixture was based on the length of each segment, and the registered fixture was used to quickly arrange the fibula pieces into the shape of the defect area. In this study, the mandibular lesion was reconstructed using registered fibular sections in one step, and the method is very easy to perform. Results and conclusion The application of additive manufacturing technology provided customized models and the cutting fixtures and registered fixtures, which can improve the efficiency of clinical application. This study showed that the cutting fixture helped to rapidly complete lesion resection and fibula cutting, and the registered fixture enabled arrangement of the fibula pieces and allowed completion of the mandible reconstruction in a timely manner. Our method can overcome the disadvantages of traditional surgery, which requires a long and different course of treatment and is liable to cause error. With the help of optimal cutting planning by the CAMRP and the 3D printed mandible resection jig and

  19. Balancing genetic uniqueness and genetic variation in determining conservation and translocation strategies: a comprehensive case study of threatened dwarf galaxias, Galaxiella pusilla (Mack) (Pisces: Galaxiidae).

    PubMed

    Coleman, R A; Weeks, A R; Hoffmann, A A

    2013-04-01

    Genetic markers are widely used to define and manage populations of threatened species based on the notion that populations with unique lineages of mtDNA and well-differentiated nuclear marker frequencies should be treated separately. However, a danger of this approach is that genetic uniqueness might be emphasized at the cost of genetic diversity, which is essential for adaptation and is potentially boosted by mixing geographically separate populations. Here, we re-explore the issue of defining management units, focussing on a detailed study of Galaxiella pusilla, a small freshwater fish of national conservation significance in Australia. Using a combination of microsatellite and mitochondrial markers, 51 populations across the species range were surveyed for genetic structure and diversity. We found an inverse relationship between genetic differentiation and genetic diversity, highlighting a long-term risk of deliberate isolation of G. pusilla populations based on protection of unique lineages. Instead, we adopt a method for identifying genetic management units that takes into consideration both uniqueness and genetic variation. This produced a management framework to guide future translocation and re-introduction efforts for G. pusilla, which contrasted to the framework based on a more traditional approach that may overlook important genetic variation in populations. PMID:23432132

  20. Resources allocation in healthcare for cancer: a case study using generalised additive mixed models.

    PubMed

    Musio, Monica; Sauleau, Erik A; Augustin, Nicole H

    2012-11-01

    Our aim is to develop a method for helping resources re-allocation in healthcare linked to cancer, in order to replan the allocation of providers. Ageing of the population has a considerable impact on the use of health resources because aged people require more specialised medical care due notably to cancer. We propose a method useful to monitor changes of cancer incidence in space and time taking into account two age categories, according to healthcar general organisation. We use generalised additive mixed models with a Poisson response, according to the methodology presented in Wood, Generalised additive models: an introduction with R. Chapman and Hall/CRC, 2006. Besides one-dimensional smooth functions accounting for non-linear effects of covariates, the space-time interaction can be modelled using scale invariant smoothers. Incidence data collected by a general cancer registry between 1992 and 2007 in a specific area of France is studied. Our best model exhibits a strong increase of the incidence of cancer along time and an obvious spatial pattern for people more than 70 years with a higher incidence in the central band of the region. This is a strong argument for re-allocating resources for old people cancer care in this sub-region. PMID:23242683

  1. Covalent binding of aniline to humic substances. 2. 15N NMR studies of nucleophilic addition reactions

    USGS Publications Warehouse

    Thorn, K.A.; Pettigrew, P.J.; Goldenberg, W.S.; Weber, E.J.

    1996-01-01

    Aromatic amines are known to undergo covalent binding with humic substances in the environment. Although previous studies have examined reaction conditions and proposed mechanisms, there has been no direct spectroscopic evidence for the covalent binding of the amines to the functional groups in humic substances. In order to further elucidate the reaction mechanisms, the Suwannee River and IHSS soil fulvic and humic acids were reacted with 15N-labeled aniline at pH 6 and analyzed using 15N NMR spectrometry. Aniline underwent nucleophilic addition reactions with the quinone and other carbonyl groups in the samples and became incorporated in the form of anilinohydroquinone, anilinoquinone, anilide, imine, and heterocyclic nitrogen, the latter comprising 50% or more of the bound amine. The anilide and anilinohydroquinone nitrogens were determined to be susceptible to chemical exchange by ammonia. In the case of Suwannee River fulvic acid, reaction under anoxic conditions and pretreatment with sodium borohydride or hydroxylamine prior to reaction under oxic conditions resulted in a decrease in the proportion of anilinohydroquinone nitrogen incorporated. The relative decrease in the incorporation of anilinohydroquinone nitrogen with respect to anilinoquinone nitrogen under anoxic conditions suggested that inter- or intramolecular redox reactions accompanied the nucleophilic addition reactions.

  2. Toxicogenomics concepts and applications to study hepatic effects of food additives and chemicals

    SciTech Connect

    Stierum, Rob . E-mail: stierum@voeding.tno.nl; Heijne, Wilbert; Kienhuis, Anne; Ommen, Ben van; Groten, John

    2005-09-01

    Transcriptomics, proteomics and metabolomics are genomics technologies with great potential in toxicological sciences. Toxicogenomics involves the integration of conventional toxicological examinations with gene, protein or metabolite expression profiles. An overview together with selected examples of the possibilities of genomics in toxicology is given. The expectations raised by toxicogenomics are earlier and more sensitive detection of toxicity. Furthermore, toxicogenomics will provide a better understanding of the mechanism of toxicity and may facilitate the prediction of toxicity of unknown compounds. Mechanism-based markers of toxicity can be discovered and improved interspecies and in vitro-in vivo extrapolations will drive model developments in toxicology. Toxicological assessment of chemical mixtures will benefit from the new molecular biological tools. In our laboratory, toxicogenomics is predominantly applied for elucidation of mechanisms of action and discovery of novel pathway-supported mechanism-based markers of liver toxicity. In addition, we aim to integrate transcriptome, proteome and metabolome data, supported by bioinformatics to develop a systems biology approach for toxicology. Transcriptomics and proteomics studies on bromobenzene-mediated hepatotoxicity in the rat are discussed. Finally, an example is shown in which gene expression profiling together with conventional biochemistry led to the discovery of novel markers for the hepatic effects of the food additives butylated hydroxytoluene, curcumin, propyl gallate and thiabendazole.

  3. Assessment of Nano Cellulose from Peach Palm Residue as Potential Food Additive: Part II: Preliminary Studies.

    PubMed

    Andrade, Dayanne Regina Mendes; Mendonça, Márcia Helena; Helm, Cristiane Vieira; Magalhães, Washington L E; de Muniz, Graciela Ines Bonzon; Kestur, Satyanarayana G

    2015-09-01

    High consumption of dietary fibers in the diet is related to the reduction of the risk of non-transmitting of chronic diseases, prevention of the constipation etc. Rich diets in dietary fibers promote beneficial effects for the metabolism. Considering the above and recognizing the multifaceted advantages of nano materials, there have been many attempts in recent times to use the nano materials in the food sector including as food additive. However, whenever new product for human and animal consumption is developed, it has to be tested for their effectiveness regarding improvement in the health of consumers, safety aspects and side effects. However, before it is tried with human beings, normally such materials would be assessed through biological tests on a living organism to understand its effect on health condition of the consumer. Accordingly, based on the authors' finding reported in a previous paper, this paper presents body weight, biochemical (glucose, cholesterol and lipid profile in blood, analysis of feces) and histological tests carried out with biomass based cellulose nano fibrils prepared by the authors for its possible use as food additive. Preliminary results of the study with mice have clearly brought out potential of these fibers for the said purpose. PMID:26344977

  4. Genetic counseling

    MedlinePlus

    Genetics is the study of heredity, the process of a parent passing certain genes on to their ... certain diseases are also often determined by genes. Genetic counseling is the process where parents can learn ...

  5. Dissection of the genetics of Parkinson's disease identifies an additional association 5′ of SNCA and multiple associated haplotypes at 17q21

    PubMed Central

    Spencer, Chris C.A.; Plagnol, Vincent; Strange, Amy; Gardner, Michelle; Paisan-Ruiz, Coro; Band, Gavin; Barker, Roger A.; Bellenguez, Celine; Bhatia, Kailash; Blackburn, Hannah; Blackwell, Jennie M.; Bramon, Elvira; Brown, Martin A.; Brown, Matthew A.; Burn, David; Casas, Juan-Pablo; Chinnery, Patrick F.; Clarke, Carl E.; Corvin, Aiden; Craddock, Nicholas; Deloukas, Panos; Edkins, Sarah; Evans, Jonathan; Freeman, Colin; Gray, Emma; Hardy, John; Hudson, Gavin; Hunt, Sarah; Jankowski, Janusz; Langford, Cordelia; Lees, Andrew J.; Markus, Hugh S.; Mathew, Christopher G.; McCarthy, Mark I.; Morrison, Karen E.; Palmer, Colin N.A.; Pearson, Justin P.; Peltonen, Leena; Pirinen, Matti; Plomin, Robert; Potter, Simon; Rautanen, Anna; Sawcer, Stephen J.; Su, Zhan; Trembath, Richard C.; Viswanathan, Ananth C.; Williams, Nigel W.; Morris, Huw R.; Donnelly, Peter; Wood, Nicholas W.

    2011-01-01

    We performed a genome-wide association study (GWAS) in 1705 Parkinson's disease (PD) UK patients and 5175 UK controls, the largest sample size so far for a PD GWAS. Replication was attempted in an additional cohort of 1039 French PD cases and 1984 controls for the 27 regions showing the strongest evidence of association (P< 10−4). We replicated published associations in the 4q22/SNCA and 17q21/MAPT chromosome regions (P< 10−10) and found evidence for an additional independent association in 4q22/SNCA. A detailed analysis of the haplotype structure at 17q21 showed that there are three separate risk groups within this region. We found weak but consistent evidence of association for common variants located in three previously published associated regions (4p15/BST1, 4p16/GAK and 1q32/PARK16). We found no support for the previously reported SNP association in 12q12/LRRK2. We also found an association of the two SNPs in 4q22/SNCA with the age of onset of the disease. PMID:21044948

  6. Genome-wide Association Studies from the Cancer Genetic Markers of Susceptibility (CGEMS) Initiative | Office of Cancer Genomics

    Cancer.gov

    CGEMS identifies common inherited genetic variations associated with a number of cancers, including breast and prostate. Data from these genome-wide association studies (GWAS) are available through the Division of Cancer Epidemiology & Genetics website.

  7. [Molecular genetics study of hereditary spastic paraplegia accompanied by distal amyotrophy-an update].

    PubMed

    Wang, Zhen-zhen; Cen, Zhi-dong; Luo, Wei

    2013-08-01

    Hereditary spastic paraplegia(HSP or SPG) is a clinically and genetically heterogeneous group of neurodegenerative diseases characterized by progressive spasticity, weakness of lower limbs, and pathologically by retrograde axonal degeneration of corticospinal tracts and posterior spinal tracts. Presence of additional features allows differentiation between simple and complex forms of the disease. Genetically, 16 loci for HSP accompanied by distal amyotrophy have been mapped, for which 13 genes have been identified. With the identification of causative genes, the molecular mechanism of this disease is gradually elucidated. PMID:23926010

  8. Comparative study of dimensional accuracy of different impression techniques using addition silicone impression material.

    PubMed

    Penaflor, C F; Semacio, R C; De Las Alas, L T; Uy, H G

    1998-01-01

    This study compared dimensional accuracy of the single, double with spacer, double with cut-out and double mix impression technique using addition silicone impression material. A typhodont containing Ivorine teeth model with six (6) full-crown tooth preparations were used as the positive control. Two stone replication models for each impression technique were made as test materials. Accuracy of the techniques were assessed by measuring four dimensions on the stone dies poured from the impression of the Ivorine teeth model. Results indicated that most of the measurements for the height, width and diameter slightly decreased and a few increased compared with the Ivorine teeth model. The double with cut-out and double mix technique presents the least difference from the master model as compared to the two latter impression techniques. PMID:10202524

  9. Spectroscopic studies of nucleic acid additions during seed-mediated growth of gold nanoparticles

    PubMed Central

    Tapp, Maeling; Sullivan, Rick; Dennis, Patrick; Naik, Rajesh R.

    2015-01-01

    The effect of adding nucleic acids to gold seeds during the growth stage of either nanospheres or nanorods was investigated using UV-Vis spectroscopy to reveal any oligonucleotide base or structure-specific effects on nanoparticle growth kinetics or plasmonic signatures. Spectral data indicate that the presence of DNA duplexes during seed ageing drastically accelerated nanosphere growth while the addition of single-stranded polyadenine at any point during seed ageing induces nanosphere aggregation. For seeds added to a gold nanorod growth solution, single-stranded polythymine induces a modest blue-shift in the longitudinal peak wavelength. Moreover, a particular sequence comprised of 50% thymine bases was found to induce a faster, more dramatic blue-shift in the longitudinal peak wavelength compared to any of the homopolymer incubation cases. Monomeric forms of the nucleic acids, however, do not yield discernable spectral differences in any of the gold suspensions studied. PMID:25960601

  10. Study on Friction and Wear Properties of Silver Matrix Brush Material with Different Additives

    NASA Astrophysics Data System (ADS)

    Chen, Xiaoli; Wang, Wenfang; Hong, Yu; Wu, Yucheng

    2013-07-01

    Friction and wear processes of AgCuX (G, CF and AlN) composites-CuAgV alloy friction pair and effects of different additive content in silver based composite on friction and wear behavior are studied in this paper. The microstructure of the brush wear surface is observed by SEM. The results show that when graphite content is up to 9 wt.%, Ag-Cu-CF-G composite exhibits the best wear properties; when the content of aluminum nitride is up to 0.5 wt.%, Ag-Cu-AlN-G composites has the most comprehensive performance. The wear loss of both composites arises with the increase of both pressure and speed, but when speed reaches a critical value, the increased amplitude of wear loss tends to be steady.

  11. Genetic and environmental influences on applied creativity: A reared-apart twin study

    PubMed Central

    Velázquez, Jaime A.; Segal, Nancy L.; Horwitz, Briana N.

    2015-01-01

    Applied creativity involves bringing innovation to real-life activities. The first reared-apart twin study assessing genetic and environmental origins of applied creativity, via Draw-a-House (DAH) and Draw-a-Person (DAP) tasks, is presented. Participants included 69 MZA and 53 DZA twin pairs from the Minnesota Study of Twins Reared Apart. Drawings were evaluated by four artists and four non-artists. Genetic effects were demonstrated for the DAP (.38–.47), but not for the DAH. Creative personality showed genetic effects (.50), and modest, but significant correlations with scores on the two drawings (rs = .17–.26). Both genetic and nonshared environmental influences underlie variance in applied creativity. Individuals concerned with enhancing creativity among students and others may better understand individual differences in performance and training. PMID:26366030

  12. An F2 Pig Resource Population as a Model for Genetic Studies of Obesity and Obesity-Related Diseases in Humans: Design and Genetic Parameters

    PubMed Central

    Kogelman, Lisette J. A.; Kadarmideen, Haja N.; Mark, Thomas; Karlskov-Mortensen, Peter; Bruun, Camilla S.; Cirera, Susanna; Jacobsen, Mette J.; Jørgensen, Claus B.; Fredholm, Merete

    2013-01-01

    Obesity is a rising worldwide public health problem. Difficulties to precisely measure various obesity traits and the genetic heterogeneity in human have been major impediments to completely disentangle genetic factors causing obesity. The pig is a relevant model for studying human obesity and obesity-related (OOR) traits. Using founder breeds divergent with respect to obesity traits we have created an F2 pig resource population (454 pigs), which has been intensively phenotyped for 36 OOR traits. The main rationale for our study is to characterize the genetic architecture of OOR traits in the F2 pig design, by estimating heritabilities, genetic, and phenotypic correlations using mixed- and multi-trait BLUP animal models. Our analyses revealed high coefficients of variation (15–42%) and moderate to high heritabilities (0.22–0.81) in fatness traits, showing large phenotypic and genetic variation in the F2 population, respectively. This fulfills the purpose of creating a resource population divergent for OOR traits. Strong genetic correlations were found between weight and lean mass at dual-energy x-ray absorptiometry scanning (0.56–0.97). Weight and conformation also showed strong genetic correlations with slaughter traits (e.g., rg between abdominal circumference and leaf fat at slaughtering: 0.66). Genetic correlations between fat-related traits and the glucose level vary between 0.35 and 0.74 and show a strong correlation between adipose tissue and impaired glucose metabolism. Our power calculations showed a minimum of 80% power for QTL detection for all phenotypes. We revealed genetic correlations at population level, for the first time, for several difficult to measure and novel OOR traits and diseases. The results underpin the potential of the established F2 pig resource population for further genomic, systems genetics, and functional investigations to unravel the genetic background of OOR traits. PMID:23515185

  13. Serum Potassium and Glucose Regulation in the ADDITION-Leicester Screening Study

    PubMed Central

    Carter, Patrice; Bodicoat, Danielle H.; Quinn, Lauren M.; Zaccardi, Francesco; Webb, David R.; Khunti, Kamlesh; Davies, Melanie J.

    2015-01-01

    Introduction. Previous observational studies have shown conflicting results between plasma K+ concentrations and risk of type 2 diabetes. To help clarify the evidence we aimed to determine whether an association existed between serum K+ and glucose regulation within a UK multiethnic population. Methods. Participants were recruited as part of the ADDITION Leicester study, a population based screening study. Individuals from primary care between the age of 40 and 75 years if White European or 25 and 75 years if South Asian or Afro Caribbean were recruited. Tests for associations between baseline characteristics and K+ quartiles were conducted using linear regression models. Results. Data showed individuals in the lowest K+ quartile had significantly greater 2-hour glucose levels (0.53 mmol/L, 95% CI: 0.36 to 0.70, P ≤ 0.001) than those in the highest K+ quartile. This estimation did not change with adjustment for potential confounders. Conversely, participants in the lowest K+ quartile had a 0.14% lower HbA1c (95% CI −0.19 to −0.10: P ≤ 0.001) compared to those in the highest K+ quartile. Conclusion. This cross-sectional analysis demonstrated that lower K+ was associated with greater 2 hr glucose. The data supports the possibility that K+ may influence glucose regulation and further research is warranted. PMID:25883988

  14. Study of triallyl phosphate as an electrolyte additive for high voltage lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Xia, J.; Madec, L.; Ma, L.; Ellis, L. D.; Qiu, W.; Nelson, K. J.; Lu, Z.; Dahn, J. R.

    2015-11-01

    The role of triallyl phosphate as an electrolyte additive in Li(Ni0.42Mn0.42Co0.16)O2/graphite pouch cells was studied using ex-situ gas measurements, ultra high precision coulometry, automated storage experiments, electrochemical impedance spectroscopy, long-term cycling and X-ray photoelectron spectroscopy. Cells containing triallyl phosphate produced less gas during formation, cycling and storage than control cells. The use of triallyl phosphate led to higher coulombic efficiency and smaller charge endpoint capacity slippage during ultra high precision charger testing. Cells containing triallyl phosphate showed smaller potential drop during 500 h storage at 40 °C and 60 °C and the voltage drop decreased as the triallyl phosphate content in the electrolyte increased. However, large amounts of triallyl phosphate (>3% by weight in the electrolyte) led to large impedance after cycling and storage. Symmetric cell studies showed large amounts of triallyl phosphate (5% or more) led to significant impedance increase at both negative and positive electrodes. X-ray photoelectron spectroscopy studies suggested that the high impedance came from the polymerization of triallyl phosphate molecules which formed thick solid electrolyte interphase films at the surfaces of both negative and positive electrodes. An optimal amount of 2%-3% triallyl phosphate led to better capacity retention during long term cycling.

  15. Genetic studies in narcolepsy, a disorder affecting REM sleep.

    PubMed

    Faraco, J; Lin, X; Li, R; Hinton, L; Lin, L; Mignot, E

    1999-01-01

    Narcolepsy is a disabling sleep disorder characterized by excessive daytime sleepiness and abnormal manifestations of rapid eye movement (REM) sleep including cataplexy, sleep paralysis, and hypnagogic hallucinations. It is known to be a complex disorder, with both genetic predisposition and environmental factors playing a role. In humans, susceptibility to narcolepsy is tightly associated with a specific HLA allele, DQB1*0602. In humans and canines, most cases are sporadic. In Doberman pinschers and Labrador retrievers, however, the disease is transmitted as an autosomal recessive gene canarc-1 with full penetrance. This gene is not linked with the dog leukocyte antigen complex, but is tightly linked with a marker with high homology to the human mu-switch immunoglobulin gene. We have isolated several genomic clones encompassing the canarc-1 marker and the variable heavy chain immunoglobulin region in canines. These have been partially sequenced and have been mapped onto specific dog chromosomes by fluorescence in situ hybridization (FISH). Our results indicate that the mu-switch-like marker is not part of the canine immunoglobulin machinery. We are continuing to extend the genomic contig using a newly developed canine BAC library and attempting to identify the corresponding human region of conserved synteny. PMID:9987919

  16. Immunologic and genetic studies of diabetes in the BB rat.

    PubMed

    Parfrey, N A; Prud'homme, G J; Colle, E; Fuks, A; Seemayer, T A; Guttmann, R D; Ono, S J

    1989-01-01

    The spontaneous development of diabetes in the Bio-Breeding (BB) rat is an excellent model of human insulin-dependent diabetes mellitus (IDDM). Disease expression is dependent on several genetically determined abnormalities, including specific major histocompatibility complex (MHC) genes. At least one MHC class II locus of the U haplotype is a necessary, but not sufficient, condition for disease expression. The immune system of BB rats is markedly abnormal. There is a striking reduction in the number and function of mature cytotoxic/suppressor T cells, a poor proliferative response to mitogens and in mixed lymphocyte culture, poor interleukin-2 production, and a reduced ability to reject skin allografts. While these immune system abnormalities are closely related to the development of diabetes, the immune recognition and effector mechanisms resulting in islet cell destruction are still poorly understood. The hypothesis that MHC class II induction on pancreatic beta cells serves to target these lymphokines, natural killer (NK) cells, macrophages, etc.) have been implicated in islet cell killing. The incidence of IDDM is reduced by immunosuppressive therapy in both rats and humans, further supporting the role of immune mechanisms in this disease. PMID:2651002

  17. Genetic Studies of the Mouse Mutations Mahogany and Mahoganoid

    PubMed Central

    Miller, K. A.; Gunn, T. M.; Carrasquillo, M. M.; Lamoreux, M. L.; Galbraith, D. B.; Barsh, G. S.

    1997-01-01

    The mouse mutations mahogany (mg) and mahoganoid (md) are negative modifiers of the Agouti coat color gene, which encodes a paracrine signaling molecule that induces a switch in melanin synthesis from eumelanin to pheomelanin. Animals mutant for md or mg synthesize very little or no pheomelanin depending on Agouti gene background. The Agouti protein is normally expressed in the skin and acts as an antagonist of the melanocyte receptor for α-MSH (Mc1r); however, ectopic expression of Agouti causes obesity, possibly by antagonizing melanocortin receptors expressed in the brain. To investigate where md and mg lie in a genetic pathway with regard to Agouti and Mc1r signaling, we determined the effects of these mutations in animals that carried either a loss-of-function Mc1r mutation (recessive yellow, Mc1r(e)) or a gain-of-function Agouti mutation (lethal yellow, A(y)). We found that the Mc1r(e) mutation suppressed the effects of md and mg, but that md and mg suppressed the effects of A(y) on both coat color and obesity. Plasma levels of α-MSH and of ACTH were unaffected by md or mg. These results suggest that md and mg interfere directly with Agouti signaling, possibly at the level of protein production or receptor regulation. PMID:9258683

  18. [Studies on the genetic susceptibility to dilated cardiomyopathy].

    PubMed

    Li, Y Y; Zhang, J N; Ma, W Z

    1993-01-01

    HLA-DQB1,-DRB1 genes of 27 Chinese patients with dilated cardiomyopathy (DCM), 7 high risk individuals in a DCM kindred and 17 normal control subjects were analysed with the use of restriction fragment length polymorphisms (RFLP) with full length DQB1 and DRB1 cDNA probes according to the standard and nomenclature of the Xth International Histocompatibility Workshop. The resulting restriction patterns allowed genotyping of HLA-DR and HLA-DQw. D-DQw8 frequency increased significantly in patients with DCM as compared with that of the controls (P < 0.05). D-DQw4 also increased in patients although no statistical significance was shown when Chi-square value was corrected with Yate's correction, whereas D-DQw5 overrepresented in controls (P < 0.05). Over half of the high risk individuals (4/7) in the familial DCM kindred carry D-DQw8 and D-DQw4. These results support the hypothesis that HLA class II genes were associated with an increased risk for DCM, HLA-DQB rather than -DRB may confer genetic susceptibility to DCM. PMID:8104770

  19. Genetic and Immunological Studies of Bacteriophage T4 Thymidylate Synthetase

    PubMed Central

    Krauss, S. W.; Stollar, B. D.; Friedkin, M.

    1973-01-01

    Thymidylate synthetase, which appears after infection of Escherichia coli with bacteriophage T4, has been partially purified. The phage enzyme is immunologically distinct from the host enzyme and has a molecular weight of 50,000 in comparison to 68,000 for the host enzyme. A system has been developed to characterize T4 td mutants previously known to have impaired expression of phage thymidylate synthetase. For this system, an E. coli host lacking thymidylate synthetase was isolated. Known genetic suppressors were transduced into this host. The resulting isogenic hosts were infected with phage T4 td mutants. The specific activities and amounts of cross-reacting material induced by several different types of phage mutants under conditions of suppression or non-suppression have been examined. The results show that the phage carries the structural gene specifying the thymidylate synthetase which appears after phage infection, and that the combination of plaque morphology, enzyme activity assays, and an assay for immunologically cross-reacting material provides a means for identifying true amber mutants of the phage gene. Images PMID:4575286

  20. Drosophila melanogaster as a genetic model system to study neurotransmitter transporters

    PubMed Central

    Martin, Ciara A.; Krantz, David E.

    2014-01-01

    The model genetic organism Drosophila melanogaster, commonly known as the fruit fly, uses many of the same neurotransmitters as mammals and very similar mechanisms of neurotransmitter storage, release and recycling. This system offers a variety of powerful molecular-genetic methods for the study of transporters, many of which would be difficult in mammalian models. We review here progress made using Drosophila to understand the function and regulation of neurotransmitter transporters and discuss future directions for its use. PMID:24704795

  1. Genetic Manipulation of Cerebellar Granule Neurons In Vitro and In Vivo to Study Neuronal Morphology and Migration

    PubMed Central

    Holubowska, Anna; Mukherjee, Chaitali; Vadhvani, Mayur; Stegmüller, Judith

    2014-01-01

    Developmental events in the brain including neuronal morphogenesis and migration are highly orchestrated processes. In vitro and in vivo analyses allow for an in-depth characterization to identify pathways involved in these events. Cerebellar granule neurons (CGNs) that are derived from the developing cerebellum are an ideal model system that allows for morphological analyses. Here, we describe a method of how to genetically manipulate CGNs and how to study axono- and dendritogenesis of individual neurons. With this method the effects of RNA interference, overexpression or small molecules can be compared to control neurons. In addition, the rodent cerebellar cortex is an easily accessible in vivo system owing to its predominant postnatal development. We also present an in vivo electroporation technique to genetically manipulate the developing cerebella and describe subsequent cerebellar analyses to assess neuronal morphology and migration. PMID:24686379

  2. Meta-analysis of genome-wide association studies reveals genetic overlap between Hodgkin lymphoma and multiple sclerosis

    PubMed Central

    Khankhanian, Pouya; Cozen, Wendy; Himmelstein, Daniel S; Madireddy, Lohith; Din, Lennox; van den Berg, Anke; Matsushita, Takuya; Glaser, Sally L; Moré, Jayaji M; Smedby, Karin E.; Baranzini, Sergio E; Mack, Thomas M; Lizée, Antoine; de Sanjosé, Silvia; Gourraud, Pierre-Antoine; Nieters, Alexandra; Hauser, Stephen L; Cocco, Pierluigi; Maynadié, Marc; Foretová, Lenka; Staines, Anthony; Delahaye-Sourdeix, Manon; Li, Dalin; Bhatia, Smita; Melbye, Mads; Onel, Kenan; Jarrett, Ruth; McKay, James D; Oksenberg, Jorge R; Hjalgrim, Henrik

    2016-01-01

    Background: Based on epidemiological commonalities, multiple sclerosis (MS) and Hodgkin lymphoma (HL), two clinically distinct conditions, have long been suspected to be aetiologically related. MS and HL occur in roughly the same age groups, both are associated with Epstein-Barr virus infection and ultraviolet (UV) light exposure, and they cluster mutually in families (though not in individuals). We speculated if in addition to sharing environmental risk factors, MS and HL were also genetically related. Using data from genome-wide association studies (GWAS) of 1816 HL patients, 9772 MS patients and 25 255 controls, we therefore investigated the genetic overlap between the two diseases. Methods: From among a common denominator of 404 K single nucleotide polymorphisms (SNPs) studied, we identified SNPs and human leukocyte antigen (HLA) alleles independently associated with both diseases. Next, we assessed the cumulative genome-wide effect of MS-associated SNPs on HL and of HL-associated SNPs on MS. To provide an interpretational frame of reference, we used data from published GWAS to create a genetic network of diseases within which we analysed proximity of HL and MS to autoimmune diseases and haematological and non-haematological malignancies. Results: SNP analyses revealed genome-wide overlap between HL and MS, most prominently in the HLA region. Polygenic HL risk scores explained 4.44% of HL risk (Nagelkerke R2), but also 2.36% of MS risk. Conversely, polygenic MS risk scores explained 8.08% of MS risk and 1.94% of HL risk. In the genetic disease network, HL was closer to autoimmune diseases than to solid cancers. Conclusions: HL displays considerable genetic overlap with MS and other autoimmune diseases. PMID:26971321

  3. Genetic differentiation of Alaska Chinook salmon: the missing link for migratory studies.

    PubMed

    Templin, William D; Seeb, James E; Jasper, James R; Barclay, Andrew W; Seeb, Lisa W

    2011-03-01

    Most information about Chinook salmon genetic diversity and life history originates from studies from the West Coast USA, western Canada and southeast Alaska; less is known about Chinook salmon from western and southcentral Alaska drainages. Populations in this large area are genetically distinct from populations to the south and represent an evolutionary legacy of unique genetic, phenotypic and life history diversity. More genetic information is necessary to advance mixed stock analysis applications for studies involving these populations. We assembled a comprehensive, open-access baseline of 45 single nucleotide polymorphisms (SNPs) from 172 populations ranging from Russia to California. We compare SNP data from representative populations throughout the range with particular emphasis on western and southcentral Alaska. We grouped populations into major lineages based upon genetic and geographic characteristics, evaluated the resolution for identifying the composition of admixtures and performed mixed stock analysis on Chinook salmon caught incidentally in the walleye pollock fishery in the Bering Sea. SNP data reveal complex genetic structure within Alaska and can be used in applications to address not only regional issues, but also migration pathways, bycatch studies on the high seas, and potential changes in the range of the species in response to climate change. PMID:21429177

  4. Parents' and children's communication about genetic risk: a qualitative study, learning from families' experiences

    PubMed Central

    Metcalfe, Alison; Plumridge, Gill; Coad, Jane; Shanks, Andrew; Gill, Paramjit

    2011-01-01

    Little is known about how parents explain to their children their risk of inheriting a gene that may cause disease in the child or in the child's future progeny. This study explored how genetic risk information is shared between family members and the factors affecting it, to ascertain the implications for children, young people and their parents to inform future service development and provision. A volunteer group of parents, children (8–11 years) and young people (12+ years) in families affected by or at risk of one of six inherited genetic conditions was interviewed. The semi-structured interviews explored the roles of family members, the language used and the self-reported psychological outcomes in a discussion on genetic risk information. The findings were analysed using grounded theory. A total of 33 families participated, which included 79 individuals. Parents often found discussing genetic risk information very difficult and emotionally painful. Discussions were not usually planned and often a major event prompted parents to finally explain genetic risks to their children; however, children usually preferred to learn about the genetic condition gradually throughout childhood. Parents identified a number of challenges they faced related to talking to children, and many thought health professionals should provide more advice to assist them in providing developmentally appropriate information. We therefore conclude that greater emphasis is required in supporting parents and children in discussing genetic risk information throughout their child's development. Open communication about genetic risks throughout childhood seemed to help children and parents cope better and come to terms with the implications of the genetic condition. PMID:21326287

  5. The Influences of Genetic and Environmental Factors on Methylome-wide Association Studies for Human Diseases

    PubMed Central

    Sun, Yan V.

    2014-01-01

    DNA methylation (DNAm) is an essential epigenetic mechanism for normal development, and its variation may be associated with diseases. High-throughput technology allows robust measurement of DNA methylome in population studies. Methylome-wide association studies (MWAS) scan DNA methylome to detect new epigenetic loci affecting disease susceptibility. MWAS is an emerging approach to unraveling the mechanism linking genetics, environment, and human diseases. Here I review the recent studies of genetic determinants and environmental modifiers of DNAm, and the concept for partitioning genetic and environmental contribution to DNAm. These studies establish the correlation maps between genome and methylome, and enable the interpretation of epigenetic association with disease traits. Recent findings suggested that MWAS was a promising genomic method to identify epigenetic predictors accounting for unexplained disease risk. However, new study designs, analytical methods and shared resources need to be implemented to address the limitations and challenges in future epigenomic epidemiologic studies. PMID:25422794

  6. The Genetics of POAG in Black South Africans: A Candidate Gene Association Study

    PubMed Central

    Williams, Susan E. I.; Carmichael, Trevor R.; Allingham, R. Rand; Hauser, Michael; Ramsay, Michele

    2015-01-01

    Multiple loci have been associated with either primary open angle glaucoma (POAG) or heritable ocular quantitative traits associated with this condition. This study examined the association of these loci with POAG, with central corneal thickness (CCT), vertical cup-to-disc ratio (VCDR) and with diabetes mellitus in a group of black South Africans (215 POAG cases and 214 controls). The population was homogeneous and distinct from other African and European populations. Single SNPs in the MYOC, COL8A2, COL1A1 and ZNF469 gene regions showed marginal associations with POAG. No association with POAG was identified with tagging SNPs in TMCO1, CAV1/CAV2, CYP1B1, COL1A2, COL5A1, CDKN2B/CDKN2BAS-1, SIX1/SIX6 or the chromosome 2p16 regions and there were no associations with CCT or VCDR. However, SNP rs12522383 in WDR36 was associated with diabetes mellitus (p = 0.00008). This first POAG genetic association study in black South Africans has therefore identified associations that require additional investigation in this and other populations to determine their significance. This highlights the need for larger studies in this population if we are to achieve the goal of facilitating early POAG detection and ultimately preventing irreversible blindness from this condition. PMID:25669751

  7. The metabochip, a custom genotyping array for genetic studies of metabolic, cardiovascular, and anthropometric traits.

    PubMed

    Voight, Benjamin F; Kang, Hyun Min; Ding, Jun; Palmer, Cameron D; Sidore, Carlo; Chines, Peter S; Burtt, Noël P; Fuchsberger, Christian; Li, Yanming; Erdmann, Jeanette; Frayling, Timothy M; Heid, Iris M; Jackson, Anne U; Johnson, Toby; Kilpeläinen, Tuomas O; Lindgren, Cecilia M; Morris, Andrew P; Prokopenko, Inga; Randall, Joshua C; Saxena, Richa; Soranzo, Nicole; Speliotes, Elizabeth K; Teslovich, Tanya M; Wheeler, Eleanor; Maguire, Jared; Parkin, Melissa; Potter, Simon; Rayner, N William; Robertson, Neil; Stirrups, Kathleen; Winckler, Wendy; Sanna, Serena; Mulas, Antonella; Nagaraja, Ramaiah; Cucca, Francesco; Barroso, Inês; Deloukas, Panos; Loos, Ruth J F; Kathiresan, Sekar; Munroe, Patricia B; Newton-Cheh, Christopher; Pfeufer, Arne; Samani, Nilesh J; Schunkert, Heribert; Hirschhorn, Joel N; Altshuler, David; McCarthy, Mark I; Abecasis, Gonçalo R; Boehnke, Michael

    2012-01-01

    Genome-wide association studies have identified hundreds of loci for type 2 diabetes, coronary artery disease and myocardial infarction, as well as for related traits such as body mass index, glucose and insulin levels, lipid levels, and blood pressure. These studies also have pointed to thousands of loci with promising but not yet compelling association evidence. To establish association at additional loci and to characterize the genome-wide significant loci by fine-mapping, we designed the "Metabochip," a custom genotyping array that assays nearly 200,000 SNP markers. Here, we describe the Metabochip and its component SNP sets, evaluate its performance in capturing variation across the allele-frequency spectrum, describe solutions to methodological challenges commonly encountered in its analysis, and evaluate its performance as a platform for genotype imputation. The metabochip achieves dramatic cost efficiencies compared to designing single-trait follow-up reagents, and provides the opportunity to compare results across a range of related traits. The metabochip and similar custom genotyping arrays offer a powerful and cost-effective approach to follow-up large-scale genotyping and sequencing studies and advance our understanding of the genetic basis of complex human diseases and traits. PMID:22876189

  8. The genetics of POAG in black South Africans: a candidate gene association study.

    PubMed

    Williams, Susan E I; Carmichael, Trevor R; Allingham, R Rand; Hauser, Michael; Ramsay, Michele

    2015-01-01

    Multiple loci have been associated with either primary open angle glaucoma (POAG) or heritable ocular quantitative traits associated with this condition. This study examined the association of these loci with POAG, with central corneal thickness (CCT), vertical cup-to-disc ratio (VCDR) and with diabetes mellitus in a group of black South Africans (215 POAG cases and 214 controls). The population was homogeneous and distinct from other African and European populations. Single SNPs in the MYOC, COL8A2, COL1A1 and ZNF469 gene regions showed marginal associations with POAG. No association with POAG was identified with tagging SNPs in TMCO1, CAV1/CAV2, CYP1B1, COL1A2, COL5A1, CDKN2B/CDKN2BAS-1, SIX1/SIX6 or the chromosome 2p16 regions and there were no associations with CCT or VCDR. However, SNP rs12522383 in WDR36 was associated with diabetes mellitus (p = 0.00008). This first POAG genetic association study in black South Africans has therefore identified associations that require additional investigation in this and other populations to determine their significance. This highlights the need for larger studies in this population if we are to achieve the goal of facilitating early POAG detection and ultimately preventing irreversible blindness from this condition. PMID:25669751

  9. Association study of DISC1 genetic variants with the risk of schizophrenia.

    PubMed

    Luo, Xin; Jin, Chunhui; Zhou, Zhenhe; Zhang, Fuquan; Yuan, Jianmin; Liu, Xiaowei; Cheng, Zaohuo

    2016-06-01

    Our previous study confirmed that the 'AA' genotype carriers of DISC1 single nucleotide polymorphism (SNP) rs821616 had a significantly increased risk for schizophrenia (SCZ) in comparison with noncarriers. To further explore the relationship of DISC1 genetic variants with the risk of SCZ in Han Chinese, we designed the present two-step study. We sequenced the promoter and untranslated regions of the DISC1 gene using genomic DNA of 100 SCZ patients and identified 17 SNPs. All SNPs were then genotyped and analyzed through a case-control study with 1154 healthy controls and 1447 patients. In an association analysis, neither allelic nor genotypic modeling indicated a significant association between the risk of SCZ and all SNPs. In addition, we observed that a two-marker haplotype was nominally associated with protection for SCZ (P=0.0476). The present findings, at least in part, provide some clues for further investigating the association of DISC1 variants with SCZ susceptibility. PMID:26945459

  10. The Metabochip, a Custom Genotyping Array for Genetic Studies of Metabolic, Cardiovascular, and Anthropometric Traits

    PubMed Central

    Ding, Jun; Palmer, Cameron D.; Sidore, Carlo; Chines, Peter S.; Burtt, Noël P.; Fuchsberger, Christian; Li, Yanming; Erdmann, Jeanette; Frayling, Timothy M.; Heid, Iris M.; Jackson, Anne U.; Johnson, Toby; Kilpeläinen, Tuomas O.; Lindgren, Cecilia M.; Morris, Andrew P.; Prokopenko, Inga; Randall, Joshua C.; Saxena, Richa; Soranzo, Nicole; Speliotes, Elizabeth K.; Teslovich, Tanya M.; Wheeler, Eleanor; Maguire, Jared; Parkin, Melissa; Potter, Simon; Rayner, N. William; Robertson, Neil; Stirrups, Kathleen; Winckler, Wendy; Sanna, Serena; Mulas, Antonella; Nagaraja, Ramaiah; Cucca, Francesco; Barroso, Inês; Deloukas, Panos; Loos, Ruth J. F.; Kathiresan, Sekar; Munroe, Patricia B.; Newton-Cheh, Christopher; Pfeufer, Arne; Samani, Nilesh J.; Schunkert, Heribert; Hirschhorn, Joel N.; Altshuler, David; McCarthy, Mark I.; Abecasis, Gonçalo R.; Boehnke, Michael

    2012-01-01

    Genome-wide association studies have identified hundreds of loci for type 2 diabetes, coronary artery disease and myocardial infarction, as well as for related traits such as body mass index, glucose and insulin levels, lipid levels, and blood pressure. These studies also have pointed to thousands of loci with promising but not yet compelling association evidence. To establish association at additional loci and to characterize the genome-wide significant loci by fine-mapping, we designed the “Metabochip,” a custom genotyping array that assays nearly 200,000 SNP markers. Here, we describe the Metabochip and its component SNP sets, evaluate its performance in capturing variation across the allele-frequency spectrum, describe solutions to methodological challenges commonly encountered in its analysis, and evaluate its performance as a platform for genotype imputation. The metabochip achieves dramatic cost efficiencies compared to designing single-trait follow-up reagents, and provides the opportunity to compare results across a range of related traits. The metabochip and similar custom genotyping arrays offer a powerful and cost-effective approach to follow-up large-scale genotyping and sequencing studies and advance our understanding of the genetic basis of complex human diseases and traits. PMID:22876189

  11. Experimental Study of Disruption of Columnar Grains During Rapid Solidification in Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Manogharan, Guha; Yelamanchi, Bharat; Aman, Ronald; Mahbooba, Zaynab

    2016-03-01

    Over the years, many studies have been conducted to study and analyze the grain structures of metal alloys during additive manufacturing to improve mechanical properties. In particular, columnar grains are observed predominantly during rapid solidification of molten metal. This leads to lower mechanical properties and requires expensive secondary heat-treatment processes. This study is aimed at disrupting the formation of columnar grain growth during rapid solidification using ultrasonic vibration and analyzes the effects on grain structure and mechanical properties. A gas-metal arc welder mounted on a Rep-Rap-based low-cost metal 3 Dimension printer was used to deposit ER70S-6 mild steel layers on a plate. A contact-type ultrasonic transducer with a control system to vary the frequency and power of the vibration was used. The effects of ultrasonic vibration were determined from the statistical analysis of microstructure and micro-indentation techniques on the deposited layer and heat-affected zone. It was found that both frequency and interaction between frequency and power had significant impact on the refinement of average grain size up to 10.64% and increased the number of grains by approximately 41.78%. Analysis of micro-indentation tests showed that there was an increase of approximately 14.30% in micro-hardness due to the applied frequency during rapid solidification. A pole diagram shows that application of vibration causes randomization of grain orientation. Along with the results from this study, further efforts in modeling and experimentation of multi-directional vibrations would lead to a better understanding of disrupting columnar grains in applications that use mechanical vibrations, such as welding, directed energy deposition, brazing, etc.

  12. Genetic variants associated with idiopathic pulmonary fibrosis susceptibility and mortality: a genome-wide association study

    PubMed Central

    Flores, Carlos; Barber, Mathew; Huang, Yong; Broderick, Steven M; Wade, Michael S; Hysi, Pirro; Scuirba, Joseph; Richards, Thomas J; Juan-Guardela, Brenda M; Vij, Rekha; Han, MeiLan K; Martinez, Fernando J; Kossen, Karl; Seiwert, Scott D; Christie, Jason D

    2013-01-01

    Summary Background Idiopathic pulmonary fibrosis (IPF) is a devastating disease that probably involves several genetic loci. Several rare genetic variants and one common single nucleotide polymorphism (SNP) of MUC5B have been associated with the disease. Our aim was to identify additional common variants associated with susceptibility and ultimately mortality in IPF. Methods First, we did a three-stage genome-wide association study (GWAS): stage one was a discovery GWAS; and stages two and three were independent case-control studies. DNA samples from European-American patients with IPF meeting standard criteria were obtained from several US centres for each stage. Data for European-American control individuals for stage one were gathered from the database of genotypes and phenotypes; additional control individuals were recruited at the University of Pittsburgh to increase the number. For controls in stages two and three, we gathered data for additional sex-matched European-American control individuals who had been recruited in another study. DNA samples from patients and from control individuals were genotyped to identify SNPs associated with IPF. SNPs identified in stage one were carried forward to stage two, and those that achieved genome-wide significance (p<5 × 10−8) in a meta-analysis were carried forward to stage three. Three case series with follow-up data were selected from stages one and two of the GWAS using samples with follow-up data. Mortality analyses were done in these case series to assess the SNPs associated with IPF that had achieved genome-wide significance in the meta-analysis of stages one and two. Finally, we obtained gene-expression profiling data for lungs of patients with IPF from the Lung Genomics Research Consortium and analysed correlation with SNP genotypes. Findings In stage one of the GWAS (542 patients with IPF, 542 control individuals matched one-by-one to cases by genetic ancestry estimates), we identified 20 loci. Six SNPs

  13. Synthesis, Characterization, Molecular Modeling, and DNA Interaction Studies of Copper Complex Containing Food Additive Carmoisine Dye.

    PubMed

    Shahabadi, Nahid; Akbari, Alireza; Jamshidbeigi, Mina; Khodarahmi, Reza

    2016-06-01

    A copper complex of carmoisine dye; [Cu(carmoisine)2(H2O)2]; was synthesized and characterized by using physico-chemical and spectroscopic methods. The binding of this complex with calf thymus (ct) DNA was investigated by circular dichroism, absorption studies, emission spectroscopy, and viscosity measurements. UV-vis results confirmed that the Cu complex interacted with DNA to form a ground-state complex and the observed binding constant (2× 10(4) M(-1)) is more in keeping with the groove bindings with DNA. Furthermore, the viscosity measurement result showed that the addition of complex causes no significant change on DNA viscosity and it indicated that the intercalation mode is ruled out. The thermodynamic parameters are calculated by van't Hoff equation, which demonstrated that hydrogen bonds and van der Waals interactions played major roles in the reaction. The results of circular dichroism (CD) suggested that the complex can change the conformation of DNA from B-like form toward A-like conformation. The cytotoxicity studies of the carmoisine dye and its copper complex indicated that both of them had anticancer effects on HT-29 (colon cancer) cell line and they may be new candidates for treatment of the colon cancer. PMID:27152751

  14. Percutaneous Dorsal Instrumentation of Vertebral Burst Fractures: Value of Additional Percutaneous Intravertebral Reposition—Cadaver Study

    PubMed Central

    Krüger, Antonio; Schmuck, Maya; Noriega, David C.; Ruchholtz, Steffen; Baroud, Gamal; Oberkircher, Ludwig

    2015-01-01

    Purpose. The treatment of vertebral burst fractures is still controversial. The aim of the study is to evaluate the purpose of additional percutaneous intravertebral reduction when combined with dorsal instrumentation. Methods. In this biomechanical cadaver study twenty-eight spine segments (T11-L3) were used (male donors, mean age 64.9 ± 6.5 years). Burst fractures of L1 were generated using a standardised protocol. After fracture all spines were allocated to four similar groups and randomised according to surgical techniques (posterior instrumentation; posterior instrumentation + intravertebral reduction device + cement augmentation; posterior instrumentation + intravertebral reduction device without cement; and intravertebral reduction device + cement augmentation). After treatment, 100000 cycles (100–600 N, 3 Hz) were applied using a servohydraulic loading frame. Results. Overall anatomical restoration was better in all groups where the intravertebral reduction device was used (p < 0.05). In particular, it was possible to restore central endplates (p > 0.05). All techniques decreased narrowing of the spinal canal. After loading, clearance could be maintained in all groups fitted with the intravertebral reduction device. Narrowing increased in the group treated with dorsal instrumentation. Conclusions. For height and anatomical restoration, the combination of an intravertebral reduction device with dorsal instrumentation showed significantly better results than sole dorsal instrumentation. PMID:26137481

  15. Density functional theory study of the effects of alloying additions on sulfur adsorption on nickel surfaces

    NASA Astrophysics Data System (ADS)

    Malyi, Oleksandr I.; Chen, Zhong; Kulish, Vadym V.; Bai, Kewu; Wu, Ping

    2013-01-01

    Reactions of hydrogen sulfide (H2S) with Nickel/Ytrria-doped zirconia (Ni/YDZ) anode materials might cause degradation of the performance of solid oxide fuel cells when S containing fuels are used. In this paper, we employ density functional theory to investigate S adsorption on metal (M)-doped and undoped Ni(0 0 1) and Ni(1 1 1) surfaces. Based on the performed calculations, we analyze the effects of 12 alloying additions (Ag, Au, Al, Bi, Cd, Co, Cu, Fe, Sn, Sb, V, and Zn) on the temperature of transition between clean (S atoms do not adsorb on the surfaces) and contaminated (S atoms can adsorb on the surfaces spontaneously) M-doped Ni surfaces for different concentrations of H2S in the fuel. Predicted results are consistent with many experimental studies relevant to S poisoning of both Ni/YDZ and M-doped Ni/YDZ anode materials. This study is important to understand S poisoning phenomena and to develop new S tolerant anode materials.

  16. Insights into metabolic disease from studying genetics in isolated populations: stories from Greece to Greenland.

    PubMed

    Zeggini, Eleftheria; Gloyn, Anna L; Hansen, Torben

    2016-05-01

    Over the last 10 years substantial progress has been made in our understanding of the genetic basis for type 2 diabetes and related traits. These developments have been facilitated by technological advancements that have allowed comprehensive genome-wide assessments of the impact of common genetic variation on disease risk. Current efforts are now focused on extending this to genetic variants in the rare and low-frequency spectrum by capitalising on next-generation sequencing technologies. This review discusses the important contributions that studies in isolated populations are making to this effort for diabetes and metabolic disease, drawing on specific examples from populations in Greece and Greenland. This review summarises a presentation given at the 'Exciting news in genetics of diabetes' symposium at the 2015 annual meeting of the EASD, with topics presented by Eleftheria Zeggini and Torben Hansen, and an overview by the Session Chair, Anna Gloyn. PMID:26993633

  17. Experimental designs for evaluation of genetic variability and selection of ancient grapevine varieties: a simulation study.

    PubMed

    Gonçalves, E; St Aubyn, A; Martins, A

    2010-06-01

    Classical methodologies for grapevine selection used in the vine-growing world are generally based on comparisons among a small number of clones. This does not take advantage of the entire genetic variability within ancient varieties, and therefore limits selection challenges. Using the general principles of plant breeding and of quantitative genetics, we propose new breeding strategies, focussed on conservation and quantification of genetic variability by performing a cycle of mass genotypic selection prior to clonal selection. To exploit a sufficiently large amount of genetic variability, initial selection trials must be generally very large. The use of experimental designs adequate for those field trials has been intensively recommended for numerous species. However, their use in initial trials of grapevines has not been studied. With the aim of identifying the most suitable experimental designs for quantification of genetic variability and selection of ancient varieties, a study was carried out to assess through simulation the comparative efficiency of various experimental designs (randomized complete block design, alpha design and row-column (RC) design). The results indicated a greater efficiency for alpha and RC designs, enabling more precise estimates of genotypic variance, greater precision in the prediction of genetic gain and consequently greater efficiency in genotypic mass selection. PMID:19904297

  18. Using laser diagnostics for studying the injection of a dry additive

    NASA Astrophysics Data System (ADS)

    Tokunov, Iu. M.; Zhilin, V. G.; Liuliukin, V. I.; Mostinskii, I. L.; Putin, Iu. A.

    1987-02-01

    In MHD generators using an ionizing additive, the uniform injection of the additive into the combustion chamber and the dispersity of the injected particles are important. Some of the problems associated with the injection of an ionizing additive can be alleviated by using dry additives. In the experiment reported here, an He-Ne laser was used to monitor the injection of potash powder with an average size of 40 microns. It is shown that laser diagnostics can be successfully used to determine the mean particle diameter and variation of the powder flow rate with time.

  19. Evaluation of additional head of biceps brachii: a study with autopsy material.

    PubMed

    Ballesteros, L E; Forero, P L; Buitrago, E R

    2014-05-01

    Additional head of the biceps brachii (AHBB) has been reported in different population groups with a frequency of 1-25%. The purpose of this study was to determine the incidence and morphologic expression of the AHBB as determined in a sample of the Colombian population. An exploration was conducted with 106 arms corresponding to unclaimed corpses autopsied at Institute of Legal and Forensic Medicine of Bucaramanga, Colombia. Using medial incision involvingskin, subcutaneous tissue, and brachial fascia, the heads of the biceps and their innervating branches were visualised. One AHBB was observed in 21 (19.8%) of the arms evaluated, with non-significant difference (p = 0.568) per side of presentation: 11 (52.4%) cases on the right side and 10 (47.6%) on the left side. All AHBBs were originated in the infero-medial segment of the humerus, with a mean thickness of 17.8 ± 6.8 mm. In 4 (19%) cases the fascicle was thin, less than 10 mm; in 7 (33.3%) cases it was of medium thickness, between 11 and 20 mm, whereas in 47.6% it was longer than 20 mm. The length of the AHBB was 118.3 ± 26.8 mm; its motor point supplied by the musculocutaneous nerve was located at 101.3 ± 20.9 mm of the bi-epicondylar line. The incidence of AHBB in this study is located at the upper segment of what has been reportedin the literature and could be a morphologic trait of the Colombian population; in agreement with prior studies, the origin was the infero-medial surface of the humerus. PMID:24902098

  20. Increased Risk of Additional Cancers Among Patients with Gastrointestinal Stromal Tumors: A Population-Based Study

    PubMed Central

    Murphy, James D.; Ma, Grace L.; Baumgartner, Joel M.; Madlensky, Lisa; Burgoyne, Adam M.; Tang, Chih-Min; Martinez, Maria Elena; Sicklick, Jason K.

    2015-01-01

    Purpose Most gastrointestinal stromal tumors (GIST) are considered non-hereditary or sporadic. However, single-institution studies suggest that GIST patients develop additional malignancies with increased frequencies. We hypothesized that we could gain greater insight into possible associations between GIST and other malignancies using a national cancer database inquiry. Methods Patients diagnosed with GIST (2001–2011) in the Surveillance, Epidemiology, and End Results database were included. Standardized prevalence ratios (SPRs) and standardized incidence ratios (SIRs) were used to quantify cancer risks incurred by GIST patients before and after GIST diagnoses, respectively, when compared with the general U.S. population. Results Of 6,112 GIST patients, 1,047 (17.1%) had additional cancers. There were significant increases in overall cancer rates: 44% (SPR=1.44) before diagnosis and 66% (SIR=1.66) after GIST diagnoses. Malignancies with significantly increased occurrence both before/after diagnoses included other sarcomas (SPR=5.24/SIR=4.02), neuroendocrine-carcinoid tumors (SPR=3.56/SIR=4.79), non-Hodgkin’s lymphoma (SPR=1.69/SIR=1.76), and colorectal adenocarcinoma (SPR=1.51/SIR=2.16). Esophageal adenocarcinoma (SPR=12.0), bladder adenocarcinoma (SPR=7.51), melanoma (SPR=1.46), and prostate adenocarcinoma (SPR=1.20) were significantly more common only before GIST. Ovarian carcinoma (SIR=8.72), small intestine adenocarcinoma (SIR=5.89), papillary thyroid cancer (SIR=5.16), renal cell carcinoma (SIR=4.46), hepatobiliary adenocarcinomas (SIR=3.10), gastric adenocarcinoma (SIR=2.70), pancreatic adenocarcinoma (SIR=2.03), uterine adenocarcinoma (SIR=1.96), non-small cell lung cancer (SIR=1.74), and transitional cell carcinoma of the bladder (SIR=1.65) were significantly more common only after GIST. Conclusion This is the first population-based study to characterize the associations and temporal relationships between GIST and other cancers, both by site and

  1. Case-control study of diabetes-related genetic variants and pancreatic cancer risk in Japan

    PubMed Central

    Kuruma, Sawako; Egawa, Naoto; Kurata, Masanao; Honda, Goro; Kamisawa, Terumi; Ueda, Junko; Ishii, Hiroshi; Ueno, Makoto; Nakao, Haruhisa; Mori, Mitsuru; Matsuo, Keitaro; Hosono, Satoyo; Ohkawa, Shinichi; Wakai, Kenji; Nakamura, Kozue; Tamakoshi, Akiko; Nojima, Masanori; Takahashi, Mami; Shimada, Kazuaki; Nishiyama, Takeshi; Kikuchi, Shogo; Lin, Yingsong

    2014-01-01

    AIM: To examine whether diabetes-related genetic variants are associated with pancreatic cancer risk. METHODS: We genotyped 7 single-nucleotide polymorphisms (SNPs) in PPARG2 (rs1801282), ADIPOQ (rs1501299), ADRB3 (rs4994), KCNQ1 (rs2237895), KCNJ11 (rs5219), TCF7L2 (rs7903146), and CDKAL1 (rs2206734), and examined their associations with pancreatic cancer risk in a multi-institute case-control study including 360 cases and 400 controls in Japan. A self-administered questionnaire was used to collect detailed information on lifestyle factors. Genotyping was performed using Fluidigm SNPtype assays. Unconditional logistic regression methods were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the association between these diabetes-associated variants and pancreatic cancer risk. RESULTS: With the exception of rs1501299 in the ADIPOQ gene (P = 0.09), no apparent differences in genotype frequencies were observed between cases and controls. Rs1501299 in the ADPIOQ gene was positively associated with pancreatic cancer risk; compared with individuals with the AA genotype, the age- and sex-adjusted OR was 1.79 (95%CI: 0.98-3.25) among those with the AC genotype and 1.86 (95%CI: 1.03-3.38) among those with the CC genotype. The ORs remained similar after additional adjustment for body mass index and cigarette smoking. In contrast, rs2237895 in the KCNQ1 gene was inversely related to pancreatic cancer risk, with a multivariable-adjusted OR of 0.62 (0.37-1.04) among individuals with the CC genotype compared with the AA genotype. No significant associations were noted for other 5 SNPs. CONCLUSION: Our case-control study indicates that rs1501299 in the ADIPOQ gene may be associated with pancreatic cancer risk. These findings should be replicated in additional studies. PMID:25516658

  2. An Ethical Study on the Uses of Enhancement Genetic Engineering

    NASA Astrophysics Data System (ADS)

    Kawakita, Koji

    A variety of biomedical technologies are being developed that can be used for purposes other than treating diseases. Such “enhancement technologies” can be used to improve our own and future generation's life-chances. While these technologies can help people in many ways, their use raises important ethical issues. Some arguments for anti-enhancement as well as pro-enhancement seem to rest, however, on shaky foundation. Both company engineers and the general public had better learn more from technological, economical and philosophical histories. For such subjects may provide engineers with less opportunities of technological misuses and more powers of self-esteem in addition to self-control.

  3. Genetic and biochemical studies of the lipid-containing bacteriophage PR4

    SciTech Connect

    Vanden Boom, T.J.

    1989-01-01

    Bacteriophage PR4 is a lipid-containing bacterial virus able to infect Escherichia coli and Salmonella typhimurium. The icosahedral virion consists of an external protein capsid layer which surrounds a membrane vesicle enclosed ds DNA genome. The author has analyzed the time course of phage PR4 protein synthesis and have identified at least 34 proteins present in phage infected cells not detected in uninfected control cultures. In addition, he has isolated a more extensive set of conditional-lethal nonsense mutants of this virus. This collection of mutants permitted the identification of seven additional phage PR4 gene products, including the terminal genome protein and an accessory lytic factor. The present collection of phage PR4 mutants has been assigned to 19 distinct genetic groups on the basis of genetic complementation tests and sodium dodecyl sulfate polyacrylamide gel electrophoresis analysis of the proteins produced in mutant-infected UV-irradiated cells. A restriction endonuclease map of the phage PR4 genome was constructed which includes 59 sites for ten restriction endonucleases. In addition, he has constructed a collection of recombinant plasmids containing subgenomic DNA fragments of bacteriophage PR4. He has used this collection of plasmids to generate a physical-genetic map of the PR4 genome. The physical-genetic map localizes mutations in 13 phage PR4 genetic groups on the viral DNA molecule. To investigate the role of phosphatidylglycerol (PG) in phage assembly and infectivity, he propagated PR4 on an E. coli mutant defective in PG synthesis. The PG content of phage PR4 grown on the mutant host accounted for 0.4% of the total viral phospholipids, representing a 90-fold decrease in PG relative to the PG content of phage grown on a wild type host.

  4. Common genetic variation and susceptibility to partial epilepsies: a genome-wide association study

    PubMed Central

    Kasperavičiūtė, Dalia; Catarino, Claudia B.; Heinzen, Erin L.; Depondt, Chantal; Cavalleri, Gianpiero L.; Caboclo, Luis O.; Tate, Sarah K.; Jamnadas-Khoda, Jenny; Chinthapalli, Krishna; Clayton, Lisa M.S.; Shianna, Kevin V.; Radtke, Rodney A.; Mikati, Mohamad A.; Gallentine, William B.; Husain, Aatif M.; Alhusaini, Saud; Leppert, David; Middleton, Lefkos T.; Gibson, Rachel A.; Johnson, Michael R.; Matthews, Paul M.; Hosford, David; Heuser, Kjell; Amos, Leslie; Ortega, Marcos; Zumsteg, Dominik; Wieser, Heinz-Gregor; Steinhoff, Bernhard J.; Krämer, Günter; Hansen, Jörg; Dorn, Thomas; Kantanen, Anne-Mari; Gjerstad, Leif; Peuralinna, Terhi; Hernandez, Dena G.; Eriksson, Kai J.; Kälviäinen, Reetta K.; Doherty, Colin P.; Wood, Nicholas W.; Pandolfo, Massimo; Duncan, John S.; Sander, Josemir W.; Delanty, Norman

    2010-01-01

    Partial epilepsies have a substantial heritability. However, the actual genetic causes are largely unknown. In contrast to many other common diseases for which genetic association-studies have successfully revealed common variants associated with disease risk, the role of common variation in partial epilepsies has not yet been explored in a well-powered study. We undertook a genome-wide association-study to identify common variants which influence risk for epilepsy shared amongst partial epilepsy syndromes, in 3445 patients and 6935 controls of European ancestry. We did not identify any genome-wide significant association. A few single nucleotide polymorphisms may warrant further investigation. We exclude common genetic variants with effect sizes above a modest 1.3 odds ratio for a single variant as contributors to genetic susceptibility shared across the partial epilepsies. We show that, at best, common genetic variation can only have a modest role in predisposition to the partial epilepsies when considered across syndromes in Europeans. The genetic architecture of the partial epilepsies is likely to be very complex, reflecting genotypic and phenotypic heterogeneity. Larger meta-analyses are required to identify variants of smaller effect sizes (odds ratio <1.3) or syndrome-specific variants. Further, our results suggest research efforts should also be directed towards identifying the multiple rare variants likely to account for at least part of the heritability of the partial epilepsies. Data emerging from genome-wide association-studies will be valuable during the next serious challenge of interpreting all the genetic variation emerging from whole-genome sequencing studies. PMID:20522523

  5. Studying Human Disease Genes in "Caenorhabditis Elegans": A Molecular Genetics Laboratory Project

    ERIC Educational Resources Information Center

    Cox-Paulson, Elisabeth A.; Grana, Theresa M.; Harris, Michelle A.; Batzli, Janet M.

    2012-01-01

    Scientists routinely integrate information from various channels to explore topics under study. We designed a 4-wk undergraduate laboratory module that used a multifaceted approach to study a question in molecular genetics. Specifically, students investigated whether "Caenorhabditis elegans" can be a useful model system for studying genes…

  6. Effect of microsatellite selection on individual and population genetic inferences: an empirical study using cross-specific and species-specific amplifications.

    PubMed

    Queirós, J; Godinho, R; Lopes, S; Gortazar, C; de la Fuente, J; Alves, P C

    2015-07-01

    Although whole-genome sequencing is becoming more accessible and feasible for nonmodel organisms, microsatellites have remained the markers of choice for various population and conservation genetic studies. However, the criteria for choosing microsatellites are still controversial due to ascertainment bias that may be introduced into the genetic inference. An empirical study of red deer (Cervus elaphus) populations, in which cross-specific and species-specific microsatellites developed through pyrosequencing of enriched libraries, was performed for this study. Two different strategies were used to select the species-specific panels: randomly vs. highly polymorphic markers. The results suggest that reliable and accurate estimations of genetic diversity can be obtained using random microsatellites distributed throughout the genome. In addition, the results reinforce previous evidence that selecting the most polymorphic markers leads to an ascertainment bias in estimates of genetic diversity, when compared with randomly selected microsatellites. Analyses of population differentiation and clustering seem less influenced by the approach of microsatellite selection, whereas assigning individuals to populations might be affected by a random selection of a small number of microsatellites. Individual multilocus heterozygosity measures produced various discordant results, which in turn had impacts on the heterozygosity-fitness correlation test. Finally, we argue that picking the appropriate microsatellite set should primarily take into account the ecological and evolutionary questions studied. Selecting the most polymorphic markers will generally overestimate genetic diversity parameters, leading to misinterpretations of the real genetic diversity, which is particularly important in managed and threatened populations. PMID:25403329

  7. Inferring Population Genetic Structure in Widely and Continuously Distributed Carnivores: The Stone Marten (Martes foina) as a Case Study.

    PubMed

    Vergara, María; Basto, Mafalda P; Madeira, María José; Gómez-Moliner, Benjamín J; Santos-Reis, Margarida; Fernandes, Carlos; Ruiz-González, Aritz

    2015-01-01

    The stone marten is a widely distributed mustelid in the Palaearctic region that exhibits variable habitat preferences in different parts of its range. The species is a Holocene immigrant from southwest Asia which, according to fossil remains, followed the expansion of the Neolithic farming cultures into Europe and possibly colonized the Iberian Peninsula during the Early Neolithic (ca. 7,000 years BP). However, the population genetic structure and historical biogeography of this generalist carnivore remains essentially unknown. In this study we have combined mitochondrial DNA (mtDNA) sequencing (621 bp) and microsatellite genotyping (23 polymorphic markers) to infer the population genetic structure of the stone marten within the Iberian Peninsula. The mtDNA data revealed low haplotype and nucleotide diversities and a lack of phylogeographic structure, most likely due to a recent colonization of the Iberian Peninsula by a few mtDNA lineages during the Early Neolithic. The microsatellite data set was analysed with a) spatial and non-spatial Bayesian individual-based clustering (IBC) approaches (STRUCTURE, TESS, BAPS and GENELAND), and b) multivariate methods [discriminant analysis of principal components (DAPC) and spatial principal component analysis (sPCA)]. Additionally, because isolation by distance (IBD) is a common spatial genetic pattern in mobile and continuously distributed species and it may represent a challenge to the performance of the above methods, the microsatellite data set was tested for its presence. Overall, the genetic structure of the stone marten in the Iberian Peninsula was characterized by a NE-SW spatial pattern of IBD, and this may explain the observed disagreement between clustering solutions obtained by the different IBC methods. However, there was significant indication for contemporary genetic structuring, albeit weak, into at least three different subpopulations. The detected subdivision could be attributed to the influence of the

  8. Inferring Population Genetic Structure in Widely and Continuously Distributed Carnivores: The Stone Marten (Martes foina) as a Case Study

    PubMed Central

    Vergara, María; Basto, Mafalda P.; Madeira, María José; Gómez-Moliner, Benjamín J.; Santos-Reis, Margarida; Fernandes, Carlos; Ruiz-González, Aritz

    2015-01-01

    The stone marten is a widely distributed mustelid in the Palaearctic region that exhibits variable habitat preferences in different parts of its range. The species is a Holocene immigrant from southwest Asia which, according to fossil remains, followed the expansion of the Neolithic farming cultures into Europe and possibly colonized the Iberian Peninsula during the Early Neolithic (ca. 7,000 years BP). However, the population genetic structure and historical biogeography of this generalist carnivore remains essentially unknown. In this study we have combined mitochondrial DNA (mtDNA) sequencing (621 bp) and microsatellite genotyping (23 polymorphic markers) to infer the population genetic structure of the stone marten within the Iberian Peninsula. The mtDNA data revealed low haplotype and nucleotide diversities and a lack of phylogeographic structure, most likely due to a recent colonization of the Iberian Peninsula by a few mtDNA lineages during the Early Neolithic. The microsatellite data set was analysed with a) spatial and non-spatial Bayesian individual-based clustering (IBC) approaches (STRUCTURE, TESS, BAPS and GENELAND), and b) multivariate methods [discriminant analysis of principal components (DAPC) and spatial principal component analysis (sPCA)]. Additionally, because isolation by distance (IBD) is a common spatial genetic pattern in mobile and continuously distributed species and it may represent a challenge to the performance of the above methods, the microsatellite data set was tested for its presence. Overall, the genetic structure of the stone marten in the Iberian Peninsula was characterized by a NE-SW spatial pattern of IBD, and this may explain the observed disagreement between clustering solutions obtained by the different IBC methods. However, there was significant indication for contemporary genetic structuring, albeit weak, into at least three different subpopulations. The detected subdivision could be attributed to the influence of the

  9. Clinical validity of new genetic biomarkers of irinotecan neutropenia: an independent replication study

    PubMed Central

    Crona, DJ; Ramirez, J; Qiao, W; de Graan, A-J; Ratain, MJ; van Schaik, RHN; Mathijssen, RHJ; Rosner, GL; Innocenti, F

    2016-01-01

    The overall goal of this study was to provide evidence for the clinical validity of nine genetic variants in five genes previously associated with irinotecan neutropenia and pharmacokinetics. Variants associated with absolute neutrophil count (ANC) nadir and/ or irinotecan pharmacokinetics in a discovery cohort of cancer patients were genotyped in an independent replication cohort of 108 cancer patients. Patients received single-agent irinotecan every 3 weeks. For ANC nadir, we replicated UGT1A1*28, UGT1A1*93 and SLCO1B1*1b in univariate analyses. For irinotecan area under the concentration–time curve (AUC0-24), we replicated ABCC2 -24C>T; however, ABCC2 -24C>T only predicted a small fraction of the variance. For SN-38 AUC0-24 and the glucuronidation ratio, we replicated UGT1A1*28 and UGT1A1*93. In addition to UGT1A1*28, this study independently validated UGT1A1*93 and SLCO1B1*1b as new predictors of irinotecan neutropenia. Further demonstration of their clinical utility will optimize irinotecan therapy in cancer patients. PMID:25869015

  10. Employing biomarkers of healthy ageing for leveraging genetic studies into human longevity.

    PubMed

    Deelen, Joris; van den Akker, Erik B; Trompet, Stella; van Heemst, Diana; Mooijaart, Simon P; Slagboom, P Eline; Beekman, Marian

    2016-09-01

    Genetic studies have thus far identified a limited number of loci associated with human longevity by applying age at death or survival up to advanced ages as phenotype. As an alternative approach, one could first try to identify biomarkers of healthy ageing and the genetic variants associated with these traits and subsequently determine the association of these variants with human longevity. In the present study, we used this approach by testing whether the 35 baseline serum parameters measured in the Leiden Longevity Study (LLS) meet the proposed criteria for a biomarker of healthy ageing. The LLS consists of 421 families with long-lived siblings of European descent, who were recruited together with their offspring and the spouses of the offspring (controls). To test the four criteria for a biomarker of healthy ageing in the LLS, we determined the association of the serum parameters with chronological age, familial longevity, general practitioner-reported general health, and mortality. Out of the 35 serum parameters, we identified glucose, insulin, and triglycerides as biomarkers of healthy ageing, meeting all four criteria in the LLS. We subsequently showed that the genetic variants previously associated with these parameters are significantly enriched in the largest genome-wide association study for human longevity. In conclusion, we showed that biomarkers of healthy ageing can be used to leverage genetic studies into human longevity. We identified several genetic variants influencing the variation in glucose, insulin and triglycerides that contribute to human longevity. PMID:27374409

  11. Additional Language Teaching within the International Baccalaureate Primary Years Programme: A Comparative Study

    ERIC Educational Resources Information Center

    Lebreton, Marlène

    2014-01-01

    The International Baccalaureate Primary Years Programme supports the learning of languages and cultures, but the role of the additional language within this programme is often unclear. There remains a great variability in schools regarding the frequency of lessons and the way that the additional language is taught within the Primary Years…

  12. Beyond the Call of Duty: A Qualitative Study of Teachers' Additional Responsibilities Related to Sexuality Education

    ERIC Educational Resources Information Center

    Eisenberg, Marla E.; Madsen, Nikki; Oliphant, Jennifer A.; Resnick, Michael

    2011-01-01

    Seven focus groups were conducted with sexuality educators in Minnesota to explore ways that teaching sexuality education differs from teaching other health education content and to determine if additional supports or resources are needed for sexuality educators. Teachers described many specific additional responsibilities or concerns related to…

  13. Experimental study of combustion characteristics of nanoscale metal and metal oxide additives in biofuel (ethanol)

    PubMed Central

    2011-01-01

    An experimental investigation of the combustion behavior of nano-aluminum (n-Al) and nano-aluminum oxide (n-Al2O3) particles stably suspended in biofuel (ethanol) as a secondary energy carrier was conducted. The heat of combustion (HoC) was studied using a modified static bomb calorimeter system. Combustion element composition and surface morphology were evaluated using a SEM/EDS system. N-Al and n-Al2O3 particles of 50- and 36-nm diameters, respectively, were utilized in this investigation. Combustion experiments were performed with volume fractions of 1, 3, 5, 7, and 10% for n-Al, and 0.5, 1, 3, and 5% for n-Al2O3. The results indicate that the amount of heat released from ethanol combustion increases almost linearly with n-Al concentration. N-Al volume fractions of 1 and 3% did not show enhancement in the average volumetric HoC, but higher volume fractions of 5, 7, and 10% increased the volumetric HoC by 5.82, 8.65, and 15.31%, respectively. N-Al2O3 and heavily passivated n-Al additives did not participate in combustion reactively, and there was no contribution from Al2O3 to the HoC in the tests. A combustion model that utilized Chemical Equilibrium with Applications was conducted as well and was shown to be in good agreement with the experimental results. PMID:21711760

  14. A theoretical study of wave dispersion and thermal conduction for HMX/additive interfaces

    NASA Astrophysics Data System (ADS)

    Long, Yao; Chen, Jun

    2014-04-01

    The wave dispersion rule for non-uniform material is useful for ultrasonic inspection and engine life prediction, and also is key in achieving an understanding of the energy dissipation and thermal conduction properties of solid material. On the basis of linear response theory and molecular dynamics, we derive a set of formulas for calculating the wave dispersion rate of interface systems, and study four kinds of interfaces inside plastic bonded explosives: HMX/{HMX, TATB, F2312, F2313}. (HMX: octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine; TATB: 1,3,5-triamino-2,4,6-trinitrobenzene; F2312, F2313: fluoropolymers). The wave dispersion rate is obtained over a wide frequency range from kHz to PHz. We find that at low frequency, the rate is proportional to the square of the frequency, and at high frequency, the rate couples with the molecular vibration modes at the interface. By using the results, the thermal conductivities of HMX/additive interfaces are derived, and a physical model is built for describing the total thermal conductivity of mixture explosives, including HMX multi-particle systems and {TATB, F2312, F2313}-coated HMX.

  15. Addition reaction of alkyl radical to C60 fullerene: Density functional theory study

    NASA Astrophysics Data System (ADS)

    Tachikawa, Hiroto; Kawabata, Hiroshi

    2016-02-01

    Functionalized fullerenes are known as a high-performance molecules. In this study, the alkyl-functionalized fullerenes (denoted by R-C60) have been investigated by means of the density functional theory (DFT) method to elucidate the effects of functionalization on the electronic states of fullerene. Also, the reaction mechanism of alkyl radicals with C60 was investigated. The methyl, ethyl, propyl, and butyl radicals (denoted by n = 1-4, where n means the number of carbon atoms in the alkyl radical) were examined as alkyl radicals. The DFT calculation showed that the alkyl radical binds to the carbon atom of C60 at the on-top site, and a strong C-C single bond is formed. The binding energies of alkyl radicals to C60 were distributed in the range of 31.8-35.1 kcal mol-1 at the CAM-B3LYP/6-311G(d,p) level. It was found that the activation barrier exists before alkyl addition, the barrier heights were calculated to be 2.1-2.8 kcal mol-1. The electronic states of R-C60 complexes were discussed on the basis of the theoretical results.

  16. Ecological Optimization and Parametric Study of an Irreversible Regenerative Modified Brayton Cycle with Isothermal Heat Addition

    NASA Astrophysics Data System (ADS)

    Tyagi, Sudhir K.; Kaushik, Subhash C.; Tiwari, Vivek

    2003-12-01

    An ecological optimization along with a detailed parametric study of an irreversible regenerative Brayton heat engine with isothermal heat addition have been carried out with external as well as internal irreversibilities. The ecological function is defined as the power output minus the power loss (irreversibility) which is ambient temperature times the entropy generation rate. The external irreversibility is due to finite temperature difference between the heat engine and the external reservoirs while the internal irreversibilities are due to nonisentropic compression and expansion processes in the compressor and the turbine respectively and the regenerative heat loss. The ecological function is found to be an increasing function of the isothermal-, sink- and regenerative-side effectiveness, isothermal-side inlet temperature, component efficiencies and sink-side temperature while it is found to be a decreasing function of the isobaric-side temperature and effectiveness and the working fluid heat capacitance rate. The effects of the isobaric-side effectiveness are found to be more than those of the other parameters and the effects of turbine efficiency are found to be more than those of the compressor efficiency on all the performance parameters of the cycle.

  17. Theoretical study of addition reactions of carbene, silylene, and germylene to carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Chu, Ying-Ying; Su, Ming-Der

    2004-08-01

    A theoretical study of the mechanism of the reaction of a single-walled carbon nanotube (SWCNT) with carbene (H 2C), silylene (H 2Si), and germylene (H 2Ge) has been carried out using a two-layered ONIOM(B3LYP/6-311G ∗:PM3) approach. The main findings are as follows: (1) The computational results based on the method used in this work are in good agreement with recent theoretical findings [Angew. Chem. Int. Ed. 41 (2002) 1853]. That is, SWCNTs with H 2C, H 2Si, and H 2Ge addends favor opened structures rather than three-membered rings. (2) The greater the atomic number of the carbene center, the larger the activation energy and the less exothermic (or the more endothermic) the cycloaddition reaction becomes. Therefore, addition to the C dbnd C bond of a SWCNT is more difficult the heavier the carbene center. (3) The theoretical observations suggest that the singlet-triplet splitting of a carbene can be used as a guide to its reactivity during the SWCNT cycloaddition process.

  18. Born to Lead? A Twin Design and Genetic Association Study of Leadership Role Occupancy*

    PubMed Central

    De Neve, Jan-Emmanuel; Mikhaylov, Slava; Dawes, Christopher T.; Christakis, Nicholas A.; Fowler, James H.

    2013-01-01

    We address leadership emergence and the possibility that there is a partially innate predisposition to occupy a leadership role. Employing twin design methods on data from the National Longitudinal Study of Adolescent Health, we estimate the heritability of leadership role occupancy at 24%. Twin studies do not point to specific genes or neurological processes that might be involved. We therefore also conduct association analysis on the available genetic markers. The results show that leadership role occupancy is associated with rs4950, a single nucleotide polymorphism (SNP) residing on a neuronal acetylcholine receptor gene (CHRNB3). We replicate this family-based genetic association result on an independent sample in the Framingham Heart Study. This is the first study to identify a specific genotype associated with the tendency to occupy a leadership position. The results suggest that what determines whether an individual occupies a leadership position is the complex product of genetic and environmental influences; with a particular role for rs4950. PMID:23459689

  19. Food additives.

    PubMed

    Berglund, F

    1978-01-01

    The use of additives to food fulfils many purposes, as shown by the index issued by the Codex Committee on Food Additives: Acids, bases and salts; Preservatives, Antioxidants and antioxidant synergists; Anticaking agents; Colours; Emulfifiers; Thickening agents; Flour-treatment agents; Extraction solvents; Carrier solvents; Flavours (synthetic); Flavour enhancers; Non-nutritive sweeteners; Processing aids; Enzyme preparations. Many additives occur naturally in foods, but this does not exclude toxicity at higher levels. Some food additives are nutrients, or even essential nutritents, e.g. NaCl. Examples are known of food additives causing toxicity in man even when used according to regulations, e.g. cobalt in beer. In other instances, poisoning has been due to carry-over, e.g. by nitrate in cheese whey - when used for artificial feed for infants. Poisonings also occur as the result of the permitted substance being added at too high levels, by accident or carelessness, e.g. nitrite in fish. Finally, there are examples of hypersensitivity to food additives, e.g. to tartrazine and other food colours. The toxicological evaluation, based on animal feeding studies, may be complicated by impurities, e.g. orthotoluene-sulfonamide in saccharin; by transformation or disappearance of the additive in food processing in storage, e.g. bisulfite in raisins; by reaction products with food constituents, e.g. formation of ethylurethane from diethyl pyrocarbonate; by metabolic transformation products, e.g. formation in the gut of cyclohexylamine from cyclamate. Metabolic end products may differ in experimental animals and in man: guanylic acid and inosinic acid are metabolized to allantoin in the rat but to uric acid in man. The magnitude of the safety margin in man of the Acceptable Daily Intake (ADI) is not identical to the "safety factor" used when calculating the ADI. The symptoms of Chinese Restaurant Syndrome, although not hazardous, furthermore illustrate that the whole ADI

  20. Specificity of Genetic Biomarker Studies in Cancer Research: A Systematic Review

    PubMed Central

    Carmona, Ruben; Zakeri, Kaveh; Lee, Chih-Han; Borgan, Saif; Marhoon, Zaid; Sharabi, Andrew; Mell, Loren K.

    2016-01-01

    As genetic information becomes more readily available, there is increasing demand from both patients and providers to develop personalized approaches to cancer care. Investigators are increasingly reporting numbers of studies correlating genomic signatures and other biomarkers to survival endpoints. The extent to which cancer-specific and non-specific effects are reported in contemporary studies is unknown. In this review of 85 high-impact studies associating genetic biomarkers with cancer outcomes, 95% reported significant associati