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Sample records for additive genetic influences

  1. 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

  2. Trends in the Genetic Influences on Smoking

    PubMed Central

    Boardman, Jason D.; Blalock, Casey L.; Pampel, Fred C.

    2011-01-01

    Using twin pairs from the National Survey of Midlife Development in the United States, we estimate that 35 percent of the variance in regular smoking is due to additive genetic influences. When we disaggregate the sample by birth cohort we witness strong genetic influences on smoking for those born in the 1920s, 1930s, and 1950s, but negligible influences for those born in the 1940s and 1960s. We show that the timing of the first Surgeon General’s Report coincides with an increase in the genetic influences on regular smoking, but subsequent legislation prohibiting smoking in public places has significantly reduced these influences. These results are in line with existing gene-environment interaction theory, and we argue that variation in genetic influences across cohorts makes it difficult and potentially misleading to estimate genetic effects on health behaviors from data obtained from a single point in time. PMID:20420298

  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. Genetic influences on brain structure.

    PubMed

    Thompson, P M; Cannon, T D; Narr, K L; van Erp, T; Poutanen, V P; Huttunen, M; Lönnqvist, J; Standertskjöld-Nordenstam, C G; Kaprio, J; Khaledy, M; Dail, R; Zoumalan, C I; Toga, A W

    2001-12-01

    Here we report on detailed three-dimensional maps revealing how brain structure is influenced by individual genetic differences. A genetic continuum was detected in which brain structure was increasingly similar in subjects with increasing genetic affinity. Genetic factors significantly influenced cortical structure in Broca's and Wernicke's language areas, as well as frontal brain regions (r2(MZ) > 0.8, p < 0.05). Preliminary correlations were performed suggesting that frontal gray matter differences may be linked to Spearman's g, which measures successful test performance across multiple cognitive domains (p < 0.05). These genetic brain maps reveal how genes determine individual differences, and may shed light on the heritability of cognitive and linguistic skills, as well as genetic liability for diseases that affect the human cortex. PMID:11694885

  6. 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

  7. Genetic factors influencing alcohol dependence

    PubMed Central

    Mayfield, R D; Harris, R A; Schuckit, M A

    2008-01-01

    Plentiful data from both animal and human studies support the importance of genetic influences in substance abuse and dependence (Bierut et al., 1998; Tsuang et al., 1998; Kendler et al., 2003). This review summarizes the evidence supporting such genetic influences, places them into perspective regarding animal and human studies, discusses the importance of both genes and environment, and highlights some specific genes of interest regarding the vulnerabilities for problems associated with alcohol use disorders. A long history of repetitive heavy use of alcohol exists across generations as well as the high prevalence of alcohol-related problems in Western societies. Moreover, the information offered here addresses the importance of more general issues regarding genetics and gene expression related to alcohol abuse and dependence. PMID:18362899

  8. Intelligence: Genetic and Environmental Influences.

    ERIC Educational Resources Information Center

    Cancro, Robert, Ed.

    This book on the genetic and environmental influences on intelligence is comprised of the following papers: "The Structure of Intelligence in Relation to the Nature-Nurture Controversy," R. B. Cattell; "Theory of Intelligence," L. G. Humphreys; "Using Measured Intelligence Intelligently," P. R. Merrifield; "Intelligence: Definition, Theory, and…

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. Genetic influences on social cognition.

    PubMed

    Skuse, David H; Gallagher, Louise

    2011-05-01

    Human social behavior develops under the influence of genetic, environmental, and cultural factors. Social cognition comprises our ability to understand and respond appropriately to other people's social approaches or responses. The concept embraces self-knowledge and theory of mind, or the ability to think about emotions and behavior from the perspective of another person. The neuropeptides oxytocin (OT) and vasopressin (AVP) are now known to play an important role, affecting individual differences in parenting behavior, social recognition, and affiliative behaviors. The processes of social cognition are also supported by reward circuitry, underpinned by the dopaminergic neurotransmitter system. Reward processes build social relationships, in parenting and pair-bonding, and influence social interactions that require trust, or display altruism. The impact of emotional regulation upon social behavior, including mood and anxiety, is also mediated through the serotonergic system. Variation in activity of serotonergic networks in the brain influences emotional responsivity, including subjective feelings, physiological responses, emotional expressions, and the tendency to become engaged in action as a consequence of a feeling state. Genetic variation in the receptors associated with OT, AVP, dopamine, and serotonin has been intensively studied in humans and animal models. Recent findings are building an increasingly coherent picture of regulatory mechanisms. PMID:21289535

  14. Environmental and genetic influences on early attachment

    PubMed Central

    Gervai, Judit

    2009-01-01

    Attachment theory predicts and subsequent empirical research has amply demonstrated that individual variations in patterns of early attachment behaviour are primarily influenced by differences in sensitive responsiveness of caregivers. However, meta-analyses have shown that parenting behaviour accounts for about one third of the variance in attachment security or disorganisation. The exclusively environmental explanation has been challenged by results demonstrating some, albeit inconclusive, evidence of the effect of infant temperament. In this paper, after reviewing briefly the well-demonstrated familial and wider environmental influences, the evidence is reviewed for genetic and gene-environment interaction effects on developing early attachment relationships. Studies investigating the interaction of genes of monoamine neurotransmission with parenting environment in the course of early relationship development suggest that children's differential susceptibility to the rearing environment depends partly on genetic differences. In addition to the overview of environmental and genetic contributions to infant attachment, and especially to disorganised attachment relevant to mental health issues, the few existing studies of gene-attachment interaction effects on development of childhood behavioural problems are also reviewed. A short account of the most important methodological problems to be overcome in molecular genetic studies of psychological and psychiatric phenotypes is also given. Finally, animal research focusing on brain-structural aspects related to early care and the new, conceptually important direction of studying environmental programming of early development through epigenetic modification of gene functioning is examined in brief. PMID:19732441

  15. 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

  16. Genetic and Environmental Influences on Adolescent Attachment

    ERIC Educational Resources Information Center

    Fearon, Pasco; Shmueli-Goetz, Yael; Viding, Essi; Fonagy, Peter; Plomin, Robert

    2014-01-01

    Background: Twin studies consistently point to limited genetic influence on attachment security in the infancy period, but no study has examined whether this remains the case in later development. This study presents the findings from a twin study examining the relative importance of genetic and environmental influences on attachment in…

  17. Genetic influence on athletic performance

    PubMed Central

    Guth, Lisa M.; Roth, Stephen M.

    2014-01-01

    Purpose of review The purpose of this review is to summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes. Recent findings Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children. Summary A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success. PMID:24240283

  18. Mapping genetic influences on human brain structure.

    PubMed

    Thompson, Paul; Cannon, Tyrone D; Toga, Arthur W

    2002-01-01

    Recent advances in brain imaging and genetics have empowered the mapping of genetic and environmental influences on the human brain. These techniques shed light on the 'nature/nurture' debate, revealing how genes determine individual differences in intelligence quotient (IQ) or risk for disease. They visualize which aspects of brain structure and function are heritable, and to what degree, linking these features with behavioral or cognitive traits or disease phenotypes. In genetically transmitted disorders such as schizophrenia, patterns of brain structure can be associated with increased disease liability, and sites can be mapped where non-genetic triggers may initiate disease. We recently developed a large-scale computational brain atlas, including data components from the Finnish Twin registry, to store information on individual variations in brain structure and their heritability. Algorithms from random field theory, anatomical modeling, and population genetics were combined to detect a genetic continuum in which brain structure is heavily genetically determined in some areas but not others. These algorithmic advances motivate studies of disease in which the normative atlas acts as a quantitative reference for the heritability of structural differences and deficits in patient populations. The resulting genetic brain maps isolate biological markers for inherited traits and disease susceptibility, which may serve as targets for genetic linkage and association studies. Computational methods from brain imaging and genetics can be fruitfully merged, to shed light on the inheritance of personality differences and behavioral traits, and the genetic transmission of diseases that affect the human brain. PMID:12553492

  19. Genetic influences on smoking: candidate genes.

    PubMed Central

    Rossing, M A

    1998-01-01

    Twin studies consistently indicate important genetic influences on multiple aspects of smoking behavior, including both initiation and cessation; however, knowledge regarding the role of specific genes is extremely limited. Habit-forming actions of nicotine appear to be triggered primarily at nicotinic receptors on the cell bodies of dopaminergic neurons in the mesolimbic "reward" system of the brain, a region implicated in addiction to other substances including cocaine, opiates, and alcohol. Important aspects of the dopaminergic pathway include synthesis of dopamine in dopaminergic neurons, release of dopamine by presynaptic neurons, receptor activation of postsynaptic neurons, dopamine re-uptake by presynaptic neurons, and metabolism of released dopamine. Research examining the role of allelic variation in genes involved in these functions is being actively pursued with respect to addictive behavior as well as personality traits and psycho- and neuropathologic conditions and has implications for smoking research. In addition, genetic differences in nicotinic receptors or nicotine metabolism might reasonably be hypothesized to play a role in smoking addiction. A role of dopaminergic or other genes in smoking cessation is of particular potential importance, as research in this area may lead to the identification of subgroups of individuals for whom pharmacologic cessation aids may be most effective. PMID:9647893

  20. How does ecological disturbance influence genetic diversity?

    PubMed

    Banks, Sam C; Cary, Geoffrey J; Smith, Annabel L; Davies, Ian D; Driscoll, Don A; Gill, A Malcolm; Lindenmayer, David B; Peakall, Rod

    2013-11-01

    Environmental disturbance underpins the dynamics and diversity of many of the ecosystems of the world, yet its influence on the patterns and distribution of genetic diversity is poorly appreciated. We argue here that disturbance history may be the major driver that shapes patterns of genetic diversity in many natural populations. We outline how disturbance influences genetic diversity through changes in both selective processes and demographically driven, selectively neutral processes. Our review highlights the opportunities and challenges presented by genetic approaches, such as landscape genomics, for better understanding and predicting the demographic and evolutionary responses of natural populations to disturbance. Developing this understanding is now critical because disturbance regimes are changing rapidly in a human-modified world. PMID:24054910

  1. 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

  2. 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

  3. IN718 Additive Manufacturing Properties and Influences

    NASA Technical Reports Server (NTRS)

    Lambert, Dennis M.

    2015-01-01

    The results of tensile, fracture, and fatigue testing of IN718 coupons produced using the selective laser melting (SLM) additive manufacturing technique are presented. The data has been "generalized" to remove the numerical values, although certain references to material standards are provided. This document provides some knowledge of the effect of variation of controlled build parameters used in the SLM process, a snapshot of the capabilities of SLM in industry at present, and shares some of the lessons learned along the way. For the build parameter characterization, the parameters were varied over a range about the machine manufacturer's recommended value, and in each case they were varied individually, although some co-variance of those parameters would be expected. SLM-produced IN718, tensile, fracture, and high-cycle fatigue properties equivalent to wrought IN718 are achievable. Build and post-build processes need to be determined and then controlled to established limits to accomplish this. It is recommended that a multi-variable evaluation, e.g., design-of-experiment (DOE), of the build parameters be performed to better evaluate the co-variance of the parameters.

  4. IN718 Additive Manufacturing Properties and Influences

    NASA Technical Reports Server (NTRS)

    Lambert, Dennis M.

    2015-01-01

    The results of tensile, fracture, and fatigue testing of IN718 coupons produced using the selective laser melting (SLM) additive manufacturing technique are presented. The data have been "sanitized" to remove the numerical values, although certain references to material standards are provided. This document provides some knowledge of the effect of variation of controlled build parameters used in the SLM process, a snapshot of the capabilities of SLM in industry at present, and shares some of the lessons learned along the way. For the build parameter characterization, the parameters were varied over a range that was centered about the machine manufacturer's recommended value, and in each case they were varied individually, although some co-variance of those parameters would be expected. Tensile, fracture, and high-cycle fatigue properties equivalent to wrought IN718 are achievable with SLM-produced IN718. Build and post-build processes need to be determined and then controlled to established limits to accomplish this. It is recommended that a multi-variable evaluation, e.g., design-of experiment (DOE), of the build parameters be performed to better evaluate the co-variance of the parameters.

  5. 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

  6. Genetic correlates influencing immunopathogenesis of HIV infection

    PubMed Central

    Sharma, Gaurav; Kaur, Gurvinder; Mehra, Narinder

    2011-01-01

    Variability to HIV infection, its progression as well as responsiveness to antiretroviral therapy (ART) is observed among individuals including viraemia controllers or exposed uninfected, rapid versus slow progressors and ART responders compared to non responders. This differential responsiveness/vulnerability to HIV-1 is governed by multiple host genetic factors that include HLA, cytokines, chemokines, their receptors and others. This review highlights the influence of these genetic factors on HIV/AIDS outcome; however, in India, the information in this area is very limited and most of these genetic studies have been conducted in Caucasian and South African populations. Considering, the population specific differences in the frequencies of protective or susceptibility favouring alleles and their influence on the disease outcome, it is of utmost importance to strengthen ongoing efforts towards defining largely unknown genetic propensity in Indian population, particularly by recruitment of large cohorts of well categorized exposed uninfected individuals, rapid, long term non progressors and elite viraemic controllers. Multi-parametric analysis of these potentially interactive immunogenetic variables in these cohorts may help to define potential targets for diagnostics and therapy in a population specific manner. PMID:22310811

  7. Influence of genetic variance on sodium sensitivity of blood pressure.

    PubMed

    Luft, F C; Miller, J Z; Weinberger, M H; Grim, C E; Daugherty, S A; Christian, J C

    1987-02-01

    To examine the effect of genetic variance on blood pressure, sodium homeostasis, and its regulatory determinants, we studied 37 pairs of monozygotic twins and 18 pairs of dizygotic twins under conditions of volume expansion and contraction. We found that, in addition to blood pressure and body size, sodium excretion in response to provocative maneuvers, glomerular filtration rate, the renin-angiotensin system, and the sympathetic nervous system are influenced by genetic variance. To elucidate the interaction of genetic factors and an environmental influence, namely, salt intake, we restricted dietary sodium in 44 families of twin children. In addition to a modest decrease in blood pressure, we found heterogeneous responses in blood pressure indicative of sodium sensitivity and resistance which were normally distributed. Strong parent-offspring resemblances were found in baseline blood pressures which persisted when adjustments were made for age and weight. Further, mother-offspring resemblances were observed in the change in blood pressure with sodium restriction. We conclude that the control of sodium homeostasis is heritable and that the change in blood pressure with sodium restriction is familial as well. These data speak to the interaction between the genetic susceptibility to hypertension and environmental influences which may result in its expression. PMID:3553721

  8. COMPETITIVE ABILITY IN MALE HOUSE MICE (Mus musculus): GENETIC INFLUENCES

    PubMed Central

    Cunningham, Christopher B.; Ruff, James S.; Chase, Kevin; Potts, Wayne K.; Carrier, David R.

    2013-01-01

    Conspecifics of many animal species physically compete to gain reproductive resources and thus fitness. Despite the importance of competitive ability across the animal kingdom, specific traits that influence or underpin competitive ability are poorly characterized. Here, we investigate whether there are genetic influences on competitive ability within male house mice. Additionally, we examined if litter demographics (litter size and litter sex ratio) influence competitive ability. We phenotyped two generations for a male s ability to possess a reproductive resource--a prime nesting site--using semi-natural enclosures with mixed sex groupings. We used the animal model coupled with an extensive pedigree to estimate several genetic parameters. Competitive ability was found to be highly heritable, but only displayed a moderate genetic correlation to body mass. Interestingly, litter sex ratio had a weak negative influence on competitive ability. Litter size had no significant influence on competitive ability. Our study also highlights how much remians unknown about the proximal causes of competitive ability. PMID:23291957

  9. Genetic and metabolic influences on LDL subclasses

    SciTech Connect

    Krauss, R.M.; Rotter, J.I.; Lusis, A.J.

    1994-09-01

    Genetic and environmental factors influence LDL particle size and density, and expression of an atherogenic lipoprotein phenotype (ALP) characterized by predominance of small, dense LDL particles. Linkage of ALP the LDL receptor locus has been reported previously. Quantitative sib-pair relative-pair linkage methodologies were used to test for linkage of LDL particle size to candidate loci in 25 large pedigrees with familial coronary artery disease. Linkage to the LDL receptor gene locus was confirmed (p=0.008). Evidence was also obtained for linkage to the genes for apoCIII, cholesteryl ester transfer protein, and manganese superoxide dismutase. The results suggest multiple genetic determinants of LDL particle size that may involve different metabolic mechanisms giving rise to small, dense LDL and increased atherosclerosis risk.

  10. Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences

    PubMed Central

    Bartholomew, Alex J.; Lad, Eleonora M.; Cao, Dingcai; Bach, Michael; Cirulli, Elizabeth T.

    2016-01-01

    Despite the large amount of variation found in the night (scotopic) vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA) and contrast sensitivity (CS) to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS) of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision. PMID:26886100

  11. Individual Differences in Scotopic Visual Acuity and Contrast Sensitivity: Genetic and Non-Genetic Influences.

    PubMed

    Bartholomew, Alex J; Lad, Eleonora M; Cao, Dingcai; Bach, Michael; Cirulli, Elizabeth T

    2016-01-01

    Despite the large amount of variation found in the night (scotopic) vision capabilities of healthy volunteers, little effort has been made to characterize this variation and factors, genetic and non-genetic, that influence it. In the largest population of healthy observers measured for scotopic visual acuity (VA) and contrast sensitivity (CS) to date, we quantified the effect of a range of variables on visual performance. We found that young volunteers with excellent photopic vision exhibit great variation in their scotopic VA and CS, and this variation is reliable from one testing session to the next. We additionally identified that factors such as Circadian preference, iris color, astigmatism, depression, sex and education have no significant impact on scotopic visual function. We confirmed previous work showing that the amount of time spent on the vision test influences performance and that laser eye surgery results in worse scotopic vision. We also showed a significant effect of intelligence and photopic visual performance on scotopic VA and CS, but all of these variables collectively explain <30% of the variation in scotopic vision. The wide variation seen in young healthy volunteers with excellent photopic vision, the high test-retest agreement, and the vast majority of the variation in scotopic vision remaining unexplained by obvious non-genetic factors suggests a strong genetic component. Our preliminary genome-wide association study (GWAS) of 106 participants ruled out any common genetic variants of very large effect and paves the way for future, larger genetic studies of scotopic vision. PMID:26886100

  12. Genetic influences in caries and periodontal diseases.

    PubMed

    Hassell, T M; Harris, E L

    1995-01-01

    Deciphering the relative roles of heredity and environmental factors ("nature vs. nurture") in the pathogenesis of dental caries and diseases of the periodontium has occupied clinical and basic researchers for decades. Success in the endeavor has come more easily in the case of caries; the complex interactions that occur between host-response mechanisms and putative microbiologic pathogens in periodontal disease have made elucidation of genetic factors in disease susceptibility more difficult. In addition, during the 30-year period between 1958 and 1987, only meager resources were targeted toward the "nature" side of the nature/nurture dipole in periodontology. In this article, we present a brief history of the development of genetic epistemology, then describe the three main research mechanisms by which questions about the hereditary component of diseases in humans can be addressed. A critical discussion of the evidence for a hereditary component in caries susceptibility is next presented, also from a historical perspective. The evolution of knowledge concerning possible genetic ("endogenous", "idiotypic") factors in the pathogenesis of inflammatory periodontal disease is initiated with an analysis of some foreign-language (primarily German) literature that is likely to be unfamiliar to the reader. We identify a turning point at about 1960, when the periodontal research community turned away from genetics in favor of microbiology research. During the past five years, investigators have re-initiated the search for the hereditary component in susceptibility to common adult periodontal disease; this small but growing body of literature is reviewed. Recent applications of in vitro methods for genetic analyses in periodontal research are presented, with an eye toward a future in which persons who are at risk--genetically predisposed--to periodontal disease may be identified and targeted for interventive strategies. Critical is the realization that genes and environment

  13. Genetic Influences on Learning Disabilties I: Clinical Genetics.

    ERIC Educational Resources Information Center

    Smith, Shelley D.; Pennington, Bruce F.

    1983-01-01

    A discussion of basic genetic principles is followed by a review of selected genetic syndromes involving learning disabilites (such as Noonan Syndrome, Neurofibromatosis, Pheuylketonuria, and cleft lip and palate). Guidelines for securing a genetic evaluation are given. (CL)

  14. Genetic and Environmental Influences on Behavior: Capturing All the Interplay

    ERIC Educational Resources Information Center

    Johnson, Wendy

    2007-01-01

    Basic quantitative genetic models of human behavioral variation have made clear that individual differences in behavior cannot be understood without acknowledging the importance of genetic influences. Yet these basic models estimate average, population-level genetic and environmental influences, obscuring differences that might exist within the…

  15. 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

  16. 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...

  17. 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

  18. 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

  19. 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

  20. Common Genetic Influences Underlie Comorbidity of Migraine and Endometriosis

    PubMed Central

    Nyholt, Dale R.; Gillespie, Nathan G.; Merikangas, Kathleen R.; Treloar, Susan A.; Martin, Nicholas G.; Montgomery, Grant W.

    2009-01-01

    We examined the co-occurrence of migraine and endometriosis within the largest known collection of families containing multiple women with surgically confirmed endometriosis and in an independent sample of 815 monozygotic and 457 dizygotic female twin pairs. Within the endometriosis families, a significantly increased risk of migrainous headache was observed in women with endometriosis compared to women without endometriosis (odds ratio [OR] 1.57, 95% confidence interval [CI]: 1.12–2.21, P = 0.009). Bivariate heritability analyses indicated no evidence for common environmental factors influencing either migraine or endometriosis but significant genetic components for both traits, with heritability estimates of 69 and 49%, respectively. Importantly, a significant additive genetic correlation (rG = 0.27, 95% CI: 0.06–0.47) and bivariate heritability (h2 = 0.17, 95% CI: 0.08–0.27) was observed between migraine and endometriosis. Controlling for the personality trait neuroticism made little impact on this association. These results confirm the previously reported comorbidity between migraine and endometriosis and indicate common genetic influences completely explain their co-occurrence within individuals. Given pharmacological treatments for endometriosis typically target hormonal pathways and a number of findings provide support for a relationship between hormonal variations and migraine, hormone-related genes and pathways are highly plausible candidates for both migraine and endometriosis. Therefore, taking into account the status of both migraine and endometriosis may provide a novel opportunity to identify the genes underlying them. Finally, we propose that the analysis of such genetically correlated comorbid traits can increase power to detect genetic risk loci through the use of more specific, homogenous and heritable phenotypes. PMID:18636479

  1. Genetic Influences on Adolescent Eating Habits

    ERIC Educational Resources Information Center

    Beaver, Kevin M.; Flores, Tori; Boutwell, Brian B.; Gibson, Chris L.

    2012-01-01

    Behavioral genetic research shows that variation in eating habits and food consumption is due to genetic and environmental factors. The current study extends this line of research by examining the genetic contribution to adolescent eating habits. Analysis of sibling pairs drawn from the National Longitudinal Study of Adolescent Health (Add Health)…

  2. The influence of additives on the crystal habit of gibbsite

    NASA Astrophysics Data System (ADS)

    Seyssiecq, Isabelle; Veesler, Stéphane; Pèpe, Gérard; Boistelle, Roland

    1999-01-01

    Crystallization of gibbsite (Al(OH) 3) is an important stage of the Bayer process, production of alumina from bauxite ores. In both pure or industrial supersaturated sodium aluminate solutions, gibbsite crystals are always agglomerated. In the present paper, we present results of a study concerning the influence of different polycarboxylic acids as crystal habit modifier for gibbsite. In pure solution, agglomerated hexagonal plates are observed. Whereas acicular and tabular morphologies are found in the presence of different additives. These results are discussed referring to the crystallographic structure of gibbsite. It is found that only oxygen atoms are present on gibbsite surface. This observation leads us to propose an additive way of acting by formation of a molecular complex between the growth unit and the carboxylic groups of the additive.

  3. 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

  4. 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

  5. Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior.

    PubMed

    Meier, Madeline H; Slutske, Wendy S; Heath, Andrew C; Martin, Nicholas G

    2011-05-01

    Sex differences in the genetic and environmental influences on childhood conduct disorder and adult antisocial behavior were examined in a large community sample of 6,383 adult male, female, and opposite-sex twins. Retrospective reports of childhood conduct disorder (prior to 18 years of age) were obtained when participants were approximately 30 years old, and lifetime reports of adult antisocial behavior (antisocial behavior after 17 years of age) were obtained 8 years later. Results revealed that either the genetic or the shared environmental factors influencing childhood conduct disorder differed for males and females (i.e., a qualitative sex difference), but by adulthood, these sex-specific influences on antisocial behavior were no longer apparent. Further, genetic and environmental influences accounted for proportionally the same amount of variance in antisocial behavior for males and females in childhood and adulthood (i.e., there were no quantitative sex differences). Additionally, the stability of antisocial behavior from childhood to adulthood was slightly greater for males than females. Though familial factors accounted for more of the stability of antisocial behavior for males than females, genetic factors accounted for the majority of the covariation between childhood conduct disorder and adult antisocial behavior for both sexes. The genetic influences on adult antisocial behavior overlapped completely with the genetic influences on childhood conduct disorder for both males and females. Implications for future twin and molecular genetic studies are discussed. PMID:21319923

  6. Genetic Influences on the Development of Grip Strength in Adolescence

    PubMed Central

    Isen, Joshua; McGue, Matt; Iacono, William

    2014-01-01

    Enhanced physical strength is a secondary sex characteristic in males. Sexual dimorphism in physical strength far exceeds sex differences in stature or total body mass, suggesting a legacy of intense sexual selection. Upper-body strength is a particularly promising marker of intra-sexual competitiveness in young men. Consequently, it is assumed that sex-influenced gene expression contributes to the development of physical strength. It is unclear, however, whether the underlying sources of individual differences in strength development are comparable across sex. We obtained three measurements of hand-grip strength (HGS) over a six-year period spanning adolescence in male and female same-sex twins (N= 2,513). Biometrical latent growth models were used to partition the HGS variance at age 11 (intercept) and its growth over time (slope) into genetic and environmental components. Results demonstrated that variance around the intercept was highly heritable in both males and females (88% and 79%, respectively). In males, variance around the slope exceeded that of the intercept, while the reverse held for females. Additive genetic effects accounted for most (80%) of the variance around the slope in males, but were of less importance in females (heritability = 28%). Absolute genetic variance around the slope was nearly nine-fold higher in males. This striking disparity suggests that the developmental processes shaping HGS growth are different between the sexes. We propose that this might account for the sex-specific pattern of associations between HGS and external measures (e.g., digit ratio and physical aggression) typically reported in the literature. Our results underscore the role of endogenous androgenic influences in the development of physical strength. PMID:24936605

  7. Genetic and Environmental Influences on Vocabulary and Reading Development

    ERIC Educational Resources Information Center

    Olson, Richard K.; Keenan, Janice M.; Byrne, Brian; Samuelsson, Stefan; Coventry, William L.; Corley, Robin; Wadsworth, Sally J.; Willcutt, Erik G.; DeFries, John C.; Pennington, Bruce F.; Hulslander, Jacqueline

    2011-01-01

    Genetic and environmental relations between vocabulary and reading skills were explored longitudinally from preschool through Grades 2 and 4. At preschool there were strong shared-environment and weak genetic influences on both vocabulary and print knowledge but substantial differences in their source. Separation of etiology for vocabulary and…

  8. Social and Genetic Influences on Adolescent Religious Attitudes and Practices

    ERIC Educational Resources Information Center

    Eaves, Lindon J.; Hatemi, Peter K.; Prom-Womley, Elizabeth C.; Murrelle, Lenn

    2008-01-01

    The authors explore the contributions of social and genetic influences to religious attitudes and practices in a population-based sample of 11-18 year olds and their mothers who responded to a Religious Attitudes and Practices Inventory and Religious Rearing Practices Inventory respectively. Contrary to genetic studies examining adult religious…

  9. 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

  10. An imaging genetics approach to understanding social influence

    PubMed Central

    Falk, Emily B.; Way, Baldwin M.; Jasinska, Agnes J.

    2012-01-01

    Normative social influences shape nearly every aspect of our lives, yet the biological processes mediating the impact of these social influences on behavior remain incompletely understood. In this Hypothesis, we outline a theoretical framework and an integrative research approach to the study of social influences on the brain and genetic moderators of such effects. First, we review neuroimaging evidence linking social influence and conformity to the brain's reward system. We next review neuroimaging evidence linking social punishment (exclusion) to brain systems involved in the experience of pain, as well as evidence linking exclusion to conformity. We suggest that genetic variants that increase sensitivity to social cues may predispose individuals to be more sensitive to either social rewards or punishments (or potentially both), which in turn increases conformity and susceptibility to normative social influences more broadly. To this end, we review evidence for genetic moderators of neurochemical responses in the brain, and suggest ways in which genes and pharmacology may modulate sensitivity to social influences. We conclude by proposing an integrative imaging genetics approach to the study of brain mediators and genetic modulators of a variety of social influences on human attitudes, beliefs, and actions. PMID:22701416

  11. Genetic and environmental influences on human behavioral differences.

    PubMed

    McGue, M; Bouchard, T J

    1998-01-01

    Human behavioral genetic research aimed at characterizing the existence and nature of genetic and environmental influences on individual differences in cognitive ability, personality and interests, and psychopathology is reviewed. Twin and adoption studies indicate that most behavioral characteristics are heritable. Nonetheless, efforts to identify the genes influencing behavior have produced a limited number of confirmed linkages or associations. Behavioral genetic research also documents the importance of environmental factors, but contrary to the expectations of many behavioral scientists, the relevant environmental factors appear to be those that are not shared by reared together relatives. The observation of genotype-environment correlational processes and the hypothesized existence of genotype-environment interaction effects serve to distinguish behavioral traits from the medical and physiological phenotypes studied by human geneticists. Behavioral genetic research supports the heritability, not the genetic determination, of behavior. PMID:9530489

  12. 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…

  13. Influence of nano-dispersive modified additive on cement activity

    NASA Astrophysics Data System (ADS)

    Sazonova, Natalya; Badenikov, Artem; Skripnikova, Nelli; Ivanova, Elizaveta

    2016-01-01

    In the work the influence of single-walled carbon nanotubes (SWCNT) on the cement activity and the processes of structure formation of the hardened cement paste in different periods of hydration are studied. The changes in the kinetic curves of the sample strength growth modified with SWCNT in amount of 0.01 and 0.0005 % are stipulated by the results of differential scanning colorimetry, scanning electronic and ionic microscopy, X-ray-phase analysis. It was found that the nano-modified additive may increase in the axis compressive strength of the system by 1.4-6.3 fold relatively to the reference samples and may reach 179.6 MPa. It may intensify the hydration process of calcium silicates as well as influence on the matrix of hardened cement paste. The studies are conducted on the structural changes in the hardened cement paste, the time periods of increase and decrease of the compressive strength of the samples, the amount of the calcium hydroxide and tobermorite-like gel as well as the degree of hydration C3S and β-C2S.

  14. 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

  15. Genetic Influences on Pubertal Development and Links to Behavior Problems

    PubMed Central

    Beltz, Adriene M.; Wadsworth, Sally J.; Berenbaum, Sheri A.

    2016-01-01

    Genetic influences on adolescent psychological development are likely to be mediated and moderated by pubertal hormones. Combining genetic analyses with advanced models of pubertal development, we extended work on the measurement and psychological significance of puberty. We examined how genetic and environmental influences on puberty vary by the way that development is described (logistic versus linear models versus traditional methods) and the different aspects of puberty (adrenarche vs. gonadarche), and how genes and environment contribute to the covariation between different descriptions and aspects of puberty, and between pubertal development and behavior problems (substance use, age at sexual initiation). We also considered how puberty moderated the heritability of psychological outcomes (internalizing and externalizing problems), and sex differences. Participants from the Colorado Longitudinal Twin Study (403 girls, 395 boys) reported their pubertal development annually from ages 9 through 15; they and their parents reported their behavior in mid-to-late adolescence. There was a large genetic contribution to pubertal timing for both sexes no matter how it was measured, but findings for pubertal tempo varied by method. Genetic covariation accounted for most of the phenotypic correlations among different indicators of pubertal timing, and between pubertal timing and psychological outcome. We consider the implications of our results for understanding how pubertal hormones mediate or moderate genetic and environmental influences on psychological development. PMID:25903988

  16. Using an Adoption Design to Separate Genetic, Prenatal, and Temperament Influences on Toddler Executive Function

    PubMed Central

    Leve, Leslie D.; DeGarmo, David S.; Bridgett, David J.; Neiderhiser, Jenae M.; Shaw, Daniel S.; Harold, Gordon T.; Natsuaki, Misaki N.; Reiss, David

    2012-01-01

    Poor executive functioning has been implicated in children’s concurrent and future behavioral difficulties, making work aimed at understanding processes related to the development of early executive function (EF) critical for models of developmental psychopathology. Deficits in EF have been associated with adverse prenatal experiences, genetic influences, and temperament characteristics. However, our ability to disentangle the predictive and independent effects of these influences has been limited by a dearth of genetically-informed research designs that also consider prenatal influences. The present study examined EF and language development in a sample of 361 toddlers who were adopted at birth and reared in non-relative adoptive families. Predictors included genetic influences (as inherited from birth mothers), prenatal risk, and growth in child negative emotionality. Structural equation modeling indicated that the effect of prenatal risk on toddler effortful attention at age 27 months became nonsignificant once genetic influences were considered in the model. In addition, genetic influences had unique effects on toddler effortful attention. Latent growth modeling indicated that increases in toddler negative emotionality from 9 to 27 months were associated with poorer delay of gratification and poorer language development. Similar results were obtained in models incorporating birth father data. Mechanisms of intergenerational transmission of EF deficits are discussed. PMID:22799580

  17. Using an adoption design to separate genetic, prenatal, and temperament influences on toddler executive function.

    PubMed

    Leve, Leslie D; DeGarmo, David S; Bridgett, David J; Neiderhiser, Jenae M; Shaw, Daniel S; Harold, Gordon T; Natsuaki, Misaki N; Reiss, David

    2013-06-01

    Poor executive functioning has been implicated in children's concurrent and future behavioral difficulties, making work aimed at understanding processes related to the development of early executive function (EF) critical for models of developmental psychopathology. Deficits in EF have been associated with adverse prenatal experiences, genetic influences, and temperament characteristics. However, our ability to disentangle the predictive and independent effects of these influences has been limited by a dearth of genetically informed research designs that also consider prenatal influences. The present study examined EF and language development in a sample of 361 toddlers who were adopted at birth and reared in nonrelative adoptive families. Predictors included genetic influences (as inherited from birth mothers), prenatal risk, and growth in child negative emotionality. Structural equation modeling indicated that the effect of prenatal risk on toddler effortful attention at age 27 months became nonsignificant once genetic influences were considered in the model. In addition, genetic influences had unique effects on toddler effortful attention. Latent growth modeling indicated that increases in toddler negative emotionality from 9 to 27 months were associated with poorer delay of gratification and poorer language development. Similar results were obtained in models incorporating birth father data. Mechanisms of intergenerational transmission of EF deficits are discussed. PMID:22799580

  18. 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

  19. Common genetic variants influence human subcortical brain structures

    PubMed Central

    Hibar, Derrek P.; Stein, Jason L.; Renteria, Miguel E.; Arias-Vasquez, Alejandro; Desrivières, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S.; Armstrong, Nicola J.; Bernard, Manon; Bohlken, Marc M.; Boks, Marco P.; Bralten, Janita; Brown, Andrew A.; Chakravarty, M. Mallar; Chen, Qiang; Ching, Christopher R. K.; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L.; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J.; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H.; Olde Loohuis, Loes M.; Luciano, Michelle; Macare, Christine; Mather, Karen A.; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L.; Roiz-Santiañez, Roberto; Rose, Emma J.; Salami, Alireza; Sämann, Philipp G.; Schmaal, Lianne; Schork, Andrew J.; Shin, Jean; Strike, Lachlan T.; Teumer, Alexander; van Donkelaar, Marjolein M. J.; van Eijk, Kristel R.; Walters, Raymond K.; Westlye, Lars T.; Whelan, Christopher D.; Winkler, Anderson M.; Zwiers, Marcel P.; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M. H.; Hartberg, Cecilie B.; Haukvik, Unn K.; Heister, Angelien J. G. A. M.; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C. M.; Lopez, Lorna M.; Makkinje, Remco R. R.; Matarin, Mar; Naber, Marlies A. M.; McKay, D. Reese; Needham, Margaret; Nugent, Allison C.; Pütz, Benno; Royle, Natalie A.; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S. L.; van Hulzen, Kimm J. E.; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A.; Bastin, Mark E.; Brodaty, Henry; Bulayeva, Kazima B.; Carless, Melanie A.; Cichon, Sven; Corvin, Aiden; Curran, Joanne E.; Czisch, Michael; de Zubicaray, Greig I.; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D.; Erk, Susanne; Fedko, Iryna O.; Ferrucci, Luigi; Foroud, Tatiana M.; Fox, Peter T.; Fukunaga, Masaki; Gibbs, J. Raphael; Göring, Harald H. H.; Green, Robert C.; Guelfi, Sebastian; Hansell, Narelle K.; Hartman, Catharina A.; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G.; Heslenfeld, Dirk J.; Hoekstra, Pieter J.; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R.; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W.; Kochunov, Peter; Kwok, John B.; Lawrie, Stephen M.; Liu, Xinmin; Longo, Dan L.; McMahon, Katie L.; Meisenzahl, Eva; Melle, Ingrid; Mohnke, Sebastian; Montgomery, Grant W.; Mostert, Jeanette C.; Mühleisen, Thomas W.; Nalls, Michael A.; Nichols, Thomas E.; Nilsson, Lars G.; Nöthen, Markus M.; Ohi, Kazutaka; Olvera, Rene L.; Perez-Iglesias, Rocio; Pike, G. Bruce; Potkin, Steven G.; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D.; Rujescu, Dan; Schnell, Knut; Schofield, Peter R.; Smith, Colin; Steen, Vidar M.; Sussmann, Jessika E.; Thalamuthu, Anbupalam; Toga, Arthur W.; Traynor, Bryan J.; Troncoso, Juan; Turner, Jessica A.; Valdés Hernández, Maria C.; van ’t Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J. A.; van Tol, Marie-Jose; Veltman, Dick J.; Wassink, Thomas H.; Westman, Eric; Zielke, Ronald H.; Zonderman, Alan B.; Ashbrook, David G.; Hager, Reinmar; Lu, Lu; McMahon, Francis J.; Morris, Derek W.; Williams, Robert W.; Brunner, Han G.; Buckner, Randy L.; Buitelaar, Jan K.; Cahn, Wiepke; Calhoun, Vince D.; Cavalleri, Gianpiero L.; Crespo-Facorro, Benedicto; Dale, Anders M.; Davies, Gareth E.; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C.; Espeseth, Thomas; Gollub, Randy L.; Ho, Beng-Choon; Hoffmann, Wolfgang; Hosten, Norbert; Kahn, René S.; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Müller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W. J. H.; Roffman, Joshua L.; Sisodiya, Sanjay M.; Smoller, Jordan W.; van Bokhoven, Hans; van Haren, Neeltje E. M.; Völzke, Henry; Walter, Henrik; Weiner, Michael W.; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A.; Blangero, John; Boomsma, Dorret I.; Brouwer, Rachel M.; Cannon, Dara M.; Cookson, Mark R.; de Geus, Eco J. C.; Deary, Ian J.; Donohoe, Gary; Fernández, Guillén; Fisher, Simon E.; Francks, Clyde; Glahn, David C.; Grabe, Hans J.; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Hulshoff Pol, Hilleke E.; Jönsson, Erik G.

    2015-01-01

    The highly complex structure of the human brain is strongly shaped by genetic influences1. Subcortical brain regions form circuits with cortical areas to coordinate movement2, learning, memory3 and motivation4, and altered circuits can lead to abnormal behaviour and disease2. To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume5 and intracranial volume6. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10−33; 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability inhuman brain development, and may help to determine mechanisms of neuropsychiatric dysfunction. PMID:25607358

  20. Common genetic variants influence human subcortical brain structures.

    PubMed

    Hibar, Derrek P; Stein, Jason L; Renteria, Miguel E; Arias-Vasquez, Alejandro; Desrivières, Sylvane; Jahanshad, Neda; Toro, Roberto; Wittfeld, Katharina; Abramovic, Lucija; Andersson, Micael; Aribisala, Benjamin S; Armstrong, Nicola J; Bernard, Manon; Bohlken, Marc M; Boks, Marco P; Bralten, Janita; Brown, Andrew A; Chakravarty, M Mallar; Chen, Qiang; Ching, Christopher R K; Cuellar-Partida, Gabriel; den Braber, Anouk; Giddaluru, Sudheer; Goldman, Aaron L; Grimm, Oliver; Guadalupe, Tulio; Hass, Johanna; Woldehawariat, Girma; Holmes, Avram J; Hoogman, Martine; Janowitz, Deborah; Jia, Tianye; Kim, Sungeun; Klein, Marieke; Kraemer, Bernd; Lee, Phil H; Olde Loohuis, Loes M; Luciano, Michelle; Macare, Christine; Mather, Karen A; Mattheisen, Manuel; Milaneschi, Yuri; Nho, Kwangsik; Papmeyer, Martina; Ramasamy, Adaikalavan; Risacher, Shannon L; Roiz-Santiañez, Roberto; Rose, Emma J; Salami, Alireza; Sämann, Philipp G; Schmaal, Lianne; Schork, Andrew J; Shin, Jean; Strike, Lachlan T; Teumer, Alexander; van Donkelaar, Marjolein M J; van Eijk, Kristel R; Walters, Raymond K; Westlye, Lars T; Whelan, Christopher D; Winkler, Anderson M; Zwiers, Marcel P; Alhusaini, Saud; Athanasiu, Lavinia; Ehrlich, Stefan; Hakobjan, Marina M H; Hartberg, Cecilie B; Haukvik, Unn K; Heister, Angelien J G A M; Hoehn, David; Kasperaviciute, Dalia; Liewald, David C M; Lopez, Lorna M; Makkinje, Remco R R; Matarin, Mar; Naber, Marlies A M; McKay, D Reese; Needham, Margaret; Nugent, Allison C; Pütz, Benno; Royle, Natalie A; Shen, Li; Sprooten, Emma; Trabzuni, Daniah; van der Marel, Saskia S L; van Hulzen, Kimm J E; Walton, Esther; Wolf, Christiane; Almasy, Laura; Ames, David; Arepalli, Sampath; Assareh, Amelia A; Bastin, Mark E; Brodaty, Henry; Bulayeva, Kazima B; Carless, Melanie A; Cichon, Sven; Corvin, Aiden; Curran, Joanne E; Czisch, Michael; de Zubicaray, Greig I; Dillman, Allissa; Duggirala, Ravi; Dyer, Thomas D; Erk, Susanne; Fedko, Iryna O; Ferrucci, Luigi; Foroud, Tatiana M; Fox, Peter T; Fukunaga, Masaki; Gibbs, J Raphael; Göring, Harald H H; Green, Robert C; Guelfi, Sebastian; Hansell, Narelle K; Hartman, Catharina A; Hegenscheid, Katrin; Heinz, Andreas; Hernandez, Dena G; Heslenfeld, Dirk J; Hoekstra, Pieter J; Holsboer, Florian; Homuth, Georg; Hottenga, Jouke-Jan; Ikeda, Masashi; Jack, Clifford R; Jenkinson, Mark; Johnson, Robert; Kanai, Ryota; Keil, Maria; Kent, Jack W; Kochunov, Peter; Kwok, John B; Lawrie, Stephen M; Liu, Xinmin; Longo, Dan L; McMahon, Katie L; Meisenzahl, Eva; Melle, Ingrid; Mohnke, Sebastian; Montgomery, Grant W; Mostert, Jeanette C; Mühleisen, Thomas W; Nalls, Michael A; Nichols, Thomas E; Nilsson, Lars G; Nöthen, Markus M; Ohi, Kazutaka; Olvera, Rene L; Perez-Iglesias, Rocio; Pike, G Bruce; Potkin, Steven G; Reinvang, Ivar; Reppermund, Simone; Rietschel, Marcella; Romanczuk-Seiferth, Nina; Rosen, Glenn D; Rujescu, Dan; Schnell, Knut; Schofield, Peter R; Smith, Colin; Steen, Vidar M; Sussmann, Jessika E; Thalamuthu, Anbupalam; Toga, Arthur W; Traynor, Bryan J; Troncoso, Juan; Turner, Jessica A; Valdés Hernández, Maria C; van 't Ent, Dennis; van der Brug, Marcel; van der Wee, Nic J A; van Tol, Marie-Jose; Veltman, Dick J; Wassink, Thomas H; Westman, Eric; Zielke, Ronald H; Zonderman, Alan B; Ashbrook, David G; Hager, Reinmar; Lu, Lu; McMahon, Francis J; Morris, Derek W; Williams, Robert W; Brunner, Han G; Buckner, Randy L; Buitelaar, Jan K; Cahn, Wiepke; Calhoun, Vince D; Cavalleri, Gianpiero L; Crespo-Facorro, Benedicto; Dale, Anders M; Davies, Gareth E; Delanty, Norman; Depondt, Chantal; Djurovic, Srdjan; Drevets, Wayne C; Espeseth, Thomas; Gollub, Randy L; Ho, Beng-Choon; Hoffmann, Wolfgang; Hosten, Norbert; Kahn, René S; Le Hellard, Stephanie; Meyer-Lindenberg, Andreas; Müller-Myhsok, Bertram; Nauck, Matthias; Nyberg, Lars; Pandolfo, Massimo; Penninx, Brenda W J H; Roffman, Joshua L; Sisodiya, Sanjay M; Smoller, Jordan W; van Bokhoven, Hans; van Haren, Neeltje E M; Völzke, Henry; Walter, Henrik; Weiner, Michael W; Wen, Wei; White, Tonya; Agartz, Ingrid; Andreassen, Ole A; Blangero, John; Boomsma, Dorret I; Brouwer, Rachel M; Cannon, Dara M; Cookson, Mark R; de Geus, Eco J C; Deary, Ian J; Donohoe, Gary; Fernández, Guillén; Fisher, Simon E; Francks, Clyde; Glahn, David C; Grabe, Hans J; Gruber, Oliver; Hardy, John; Hashimoto, Ryota; Hulshoff Pol, Hilleke E; Jönsson, Erik G; Kloszewska, Iwona; Lovestone, Simon; Mattay, Venkata S; Mecocci, Patrizia; McDonald, Colm; McIntosh, Andrew M; Ophoff, Roel A; Paus, Tomas; Pausova, Zdenka; Ryten, Mina; Sachdev, Perminder S; Saykin, Andrew J; Simmons, Andy

    2015-04-01

    The highly complex structure of the human brain is strongly shaped by genetic influences. Subcortical brain regions form circuits with cortical areas to coordinate movement, learning, memory and motivation, and altered circuits can lead to abnormal behaviour and disease. To investigate how common genetic variants affect the structure of these brain regions, here we conduct genome-wide association studies of the volumes of seven subcortical regions and the intracranial volume derived from magnetic resonance images of 30,717 individuals from 50 cohorts. We identify five novel genetic variants influencing the volumes of the putamen and caudate nucleus. We also find stronger evidence for three loci with previously established influences on hippocampal volume and intracranial volume. These variants show specific volumetric effects on brain structures rather than global effects across structures. The strongest effects were found for the putamen, where a novel intergenic locus with replicable influence on volume (rs945270; P = 1.08 × 10(-33); 0.52% variance explained) showed evidence of altering the expression of the KTN1 gene in both brain and blood tissue. Variants influencing putamen volume clustered near developmental genes that regulate apoptosis, axon guidance and vesicle transport. Identification of these genetic variants provides insight into the causes of variability in human brain development, and may help to determine mechanisms of neuropsychiatric dysfunction. PMID:25607358

  1. [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

  2. Measurement and Associations of Pregnancy Risk Factors with Genetic Influences, Postnatal Environmental Influences, and Toddler Behavior

    ERIC Educational Resources Information Center

    Marceau, Kristine; Hajal, Nastassia; Leve, Leslie D.; Reiss, David; Shaw, Daniel S.; Ganiban, Jody M.; Mayes, Linda C.; Neiderhiser, Jenae M.

    2013-01-01

    This study demonstrates the unique contributions of perinatal risk and genetic and environmental influences on child behavior using data from 561 domestic US adoption triads (birth mothers, adopted child, and adoptive parents). Findings show distinct patterns of associations among genetic (birth mother psychopathology), prenatal (six maternal…

  3. 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

  4. Irradiation influence on the detection of genetic-modified soybeans

    NASA Astrophysics Data System (ADS)

    Villavicencio, A. L. C. H.; Araújo, M. M.; Baldasso, J. G.; Aquino, S.; Konietzny, U.; Greiner, R.

    2004-09-01

    Three soybean varieties were analyzed to evaluate the irradiation influence on the detection of genetic modification. Samples were treated in a 60Co facility at dose levels of 0, 500, 800, and 1000Gy. The seeds were at first analyzed by Comet Assay as a rapid screening irradiation detection method. Secondly, germination test was performed to detect the viability of irradiated soybeans. Finally, because of its high sensitivity, its specificity and rapidity the polimerase chain reaction was the method applied for genetic modified organism detection. The analysis of DNA by the single technique of microgel electrophoresis of single cells (DNA Comet Assay) showed that DNA damage increased with increasing radiation doses. No negative influence of irradiation on the genetic modification detection was found.

  5. The influence of recombination on human genetic diversity.

    PubMed

    Spencer, Chris C A; Deloukas, Panos; Hunt, Sarah; Mullikin, Jim; Myers, Simon; Silverman, Bernard; Donnelly, Peter; Bentley, David; McVean, Gil

    2006-09-22

    In humans, the rate of recombination, as measured on the megabase scale, is positively associated with the level of genetic variation, as measured at the genic scale. Despite considerable debate, it is not clear whether these factors are causally linked or, if they are, whether this is driven by the repeated action of adaptive evolution or molecular processes such as double-strand break formation and mismatch repair. We introduce three innovations to the analysis of recombination and diversity: fine-scale genetic maps estimated from genotype experiments that identify recombination hotspots at the kilobase scale, analysis of an entire human chromosome, and the use of wavelet techniques to identify correlations acting at different scales. We show that recombination influences genetic diversity only at the level of recombination hotspots. Hotspots are also associated with local increases in GC content and the relative frequency of GC-increasing mutations but have no effect on substitution rates. Broad-scale association between recombination and diversity is explained through covariance of both factors with base composition. To our knowledge, these results are the first evidence of a direct and local influence of recombination hotspots on genetic variation and the fate of individual mutations. However, that hotspots have no influence on substitution rates suggests that they are too ephemeral on an evolutionary time scale to have a strong influence on broader scale patterns of base composition and long-term molecular evolution. PMID:17044736

  6. Further Evidence for Genetic Influences on Educational Achievement.

    ERIC Educational Resources Information Center

    Gill, C. E.; And Others

    1985-01-01

    This study analyzed the Tertiary Admission Examination and Australian Scholastic Aptitude Test results for 264 pairs of 17-year-old monozygotic and dizygotic twins in Western Australia to determine if examination performance is influenced by environmental or genetic factors. Purely environmental models are rejected as inadequate explanations of…

  7. Reading Development in Young Children: Genetic and Environmental Influences

    ERIC Educational Resources Information Center

    Logan, Jessica A. R.; Hart, Sara A.; Cutting, Laurie; Deater-Deckard, Kirby; Schatschneider, Chris; Petrill, Stephen

    2013-01-01

    The development of reading skills in typical students is commonly described as a rapid growth across early grades of active reading education, with a slowing down of growth as active instruction tapers. This study examined the extent to which genetics and environments influence these growth rates. Participants were 371 twin pairs, aged…

  8. Genetic relatedness influences plant biomass accumulation in eelgrass (Zostera marina).

    PubMed

    Stachowicz, John J; Kamel, Stephanie J; Hughes, A Randall; Grosberg, Richard K

    2013-05-01

    In multispecies assemblages, phylogenetic relatedness often predicts total community biomass. In assemblages dominated by a single species, increasing the number of genotypes increases total production, but the role of genetic relatedness is unknown. We used data from three published experiments and a field survey of eelgrass (Zostera marina), a habitat-forming marine angiosperm, to examine the strength and direction of the relationship between genetic relatedness and plant biomass. The genetic relatedness of an assemblage strongly predicted its biomass, more so than the number of genotypes. However, contrary to the pattern observed in multispecies assemblages, maximum biomass occurred in assemblages of more closely related individuals. The mechanisms underlying this pattern remain unclear; however, our data support a role for both trait differentiation and cooperation among kin. Many habitat-forming species interact intensely with conspecifics of varying relatedness; thus, genetic relatedness could influence the functioning of ecosystems dominated by such species. PMID:23594554

  9. Mapping genetic influences on ventricular structure in twins

    PubMed Central

    Chou, Yi-Yu; Leporé, Natasha; Chiang, Ming-Chang; Avedissian, Christina; Barysheva, Marina; McMahon, Katie L.; de Zubicaray, Greig I.; Meredith, Matthew; Wright, Margaret J.; Toga, Arthur W.; Thompson, Paul M.

    2009-01-01

    Despite substantial progress in measuring the anatomical and functional variability of the human brain, little is known about the genetic and environmental causes of these variations. Here we developed an automated system to visualize genetic and environmental effects on brain structure in large brain MRI databases. We applied our multi-template segmentation approach termed “Multi-Atlas Fluid Image Alignment” to fluidly propagate hand-labeled parameterized surface meshes, labeling the lateral ventricles, in 3D volumetric MRI scans of 76 identical (monozygotic, MZ) twins (38 pairs; mean age=24.6 (SD=1.7)); and 56 same-sex fraternal (dizygotic, DZ) twins (28 pairs; mean age=23.0 (SD=1.8)), scanned as part of a 5-year research study that will eventually study over 1000 subjects. Mesh surfaces were averaged within subjects to minimize segmentation error. We fitted quantitative genetic models at each of 30,000 surface points to measure the proportion of shape variance attributable to (1) genetic differences among subjects, (2) environmental influences unique to each individual, and (3) shared environmental effects. Surface-based statistical maps, derived from path analysis, revealed patterns of heritability, and their significance, in 3D. Path coefficients for the ‘ACE’ model that best fitted the data indicated significant contributions from genetic factors (A=7.3%), common environment (C=38.9%) and unique environment (E=53.8%) to lateral ventricular volume. Earlier-maturing occipital horn regions may also be more genetically influenced than later-maturing frontal regions. Maps visualized spatially-varying profiles of environmental versus genetic influences. The approach shows promise for automatically measuring gene-environment effects in large image databases. PMID:19041405

  10. Distinct Genetic Influences on Cortical and Subcortical Brain Structures.

    PubMed

    Wen, Wei; Thalamuthu, Anbupalam; Mather, Karen A; Zhu, Wanlin; Jiang, Jiyang; de Micheaux, Pierre Lafaye; Wright, Margaret J; Ames, David; Sachdev, Perminder S

    2016-01-01

    This study examined the heritability of brain grey matter structures in a subsample of older adult twins (93 MZ and 68 DZ twin pairs; mean age 70 years) from the Older Australian Twins Study. The heritability estimates of subcortical regions ranged from 0.41 (amygdala) to 0.73 (hippocampus), and of cortical regions, from 0.55 (parietal lobe) to 0.78 (frontal lobe). Corresponding structures in the two hemispheres were influenced by the same genetic factors and high genetic correlations were observed between the two hemispheric regions. There were three genetically correlated clusters, comprising (i) the cortical lobes (frontal, temporal, parietal and occipital lobes); (ii) the basal ganglia (caudate, putamen and pallidum) with weak genetic correlations with cortical lobes, and (iii) the amygdala, hippocampus, thalamus and nucleus accumbens grouped together, which genetically correlated with both basal ganglia and cortical lobes, albeit relatively weakly. Our study demonstrates a complex but patterned and clustered genetic architecture of the human brain, with divergent genetic determinants of cortical and subcortical structures, in particular the basal ganglia. PMID:27595976

  11. Distinct Genetic Influences on Cortical and Subcortical Brain Structures

    PubMed Central

    Wen, Wei; Thalamuthu, Anbupalam; Mather, Karen A.; Zhu, Wanlin; Jiang, Jiyang; de Micheaux, Pierre Lafaye; Wright, Margaret J.; Ames, David; Sachdev, Perminder S.

    2016-01-01

    This study examined the heritability of brain grey matter structures in a subsample of older adult twins (93 MZ and 68 DZ twin pairs; mean age 70 years) from the Older Australian Twins Study. The heritability estimates of subcortical regions ranged from 0.41 (amygdala) to 0.73 (hippocampus), and of cortical regions, from 0.55 (parietal lobe) to 0.78 (frontal lobe). Corresponding structures in the two hemispheres were influenced by the same genetic factors and high genetic correlations were observed between the two hemispheric regions. There were three genetically correlated clusters, comprising (i) the cortical lobes (frontal, temporal, parietal and occipital lobes); (ii) the basal ganglia (caudate, putamen and pallidum) with weak genetic correlations with cortical lobes, and (iii) the amygdala, hippocampus, thalamus and nucleus accumbens grouped together, which genetically correlated with both basal ganglia and cortical lobes, albeit relatively weakly. Our study demonstrates a complex but patterned and clustered genetic architecture of the human brain, with divergent genetic determinants of cortical and subcortical structures, in particular the basal ganglia. PMID:27595976

  12. 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

  13. Landscape influences on genetic differentiation among bull trout populations in a stream-lake network

    USGS Publications Warehouse

    Meeuwig, M.H.; Guy, C.S.; Kalinowski, S.T.; Fredenberg, W.A.

    2010-01-01

    This study examined the influence of landscape heterogeneity on genetic differentiation between migratory bull trout (Salvelinus confluentus) populations in Glacier National Park, Montana. An information-theoretic approach was used to compare different conceptual models of dispersal associated with barriers, different models of isolation by distance, and the combined effects of barriers, waterway distance, patch size, and intra- and inter-drainage distribution of populations on genetic differentiation between bull trout populations. The effect of distance between populations on genetic differentiation was best explained by partitioning the effects of mainstem and tributary stream sections. Models that categorized barriers as having a one-way effect (i.e. allowed downstream dispersal) or a two-way effect were best supported. Additionally, patch size and the distribution of populations among drainages influenced genetic differentiation. Genetic differentiation between bull trout populations in Glacier National Park is linked to landscape features that restrict dispersal. However, this analysis illustrates that modelling variability within landscape features, such as dispersal corridors, will benefit landscape genetic analyses. Additionally, the framework used for evaluating the effects of barriers must consider not just barrier presence, but also potential asymmetries in barrier effects with respect to the organism under investigation.

  14. Landscape influences on genetic differentiation among bull trout populations in a stream-lake network.

    PubMed

    Meeuwig, Michael H; Guy, Christopher S; Kalinowski, Steven T; Fredenberg, Wade A

    2010-09-01

    This study examined the influence of landscape heterogeneity on genetic differentiation between migratory bull trout (Salvelinus confluentus) populations in Glacier National Park, Montana. An information-theoretic approach was used to compare different conceptual models of dispersal associated with barriers, different models of isolation by distance, and the combined effects of barriers, waterway distance, patch size, and intra- and inter-drainage distribution of populations on genetic differentiation between bull trout populations. The effect of distance between populations on genetic differentiation was best explained by partitioning the effects of mainstem and tributary stream sections. Models that categorized barriers as having a one-way effect (i.e. allowed downstream dispersal) or a two-way effect were best supported. Additionally, patch size and the distribution of populations among drainages influenced genetic differentiation. Genetic differentiation between bull trout populations in Glacier National Park is linked to landscape features that restrict dispersal. However, this analysis illustrates that modelling variability within landscape features, such as dispersal corridors, will benefit landscape genetic analyses. Additionally, the framework used for evaluating the effects of barriers must consider not just barrier presence, but also potential asymmetries in barrier effects with respect to the organism under investigation. PMID:20723065

  15. 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

  16. 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

  17. Drinking experience uncovers genetic influences on alcohol expectancies across adolescence

    PubMed Central

    Young-Wolff, Kelly C.; Wang, Pan; Tuvblad, Catherine; Baker, Laura A.; Raine, Adrian; Prescott, Carol A.

    2015-01-01

    Aims To test whether drinking onset moderates genetic and environmental contributions to individual differences in the etiology of alcohol expectancies across adolescence. Design Longitudinal twin design. Setting Community sample from Los Angeles, CA, USA. Participants A total of 1292 male and female twins, aged 11–18 years, were assessed at 1 (n = 440), 2 (n = 587) or 3 (n = 265) occasions as part of the risk factors for the Antisocial Behavior Twin Study. Measurements Social behavioral (SB) alcohol expectancies were measured using an abbreviated version of the Social Behavioral subscale from the Alcohol Expectancy Questionnaire for adolescents (AEQ-A). Drinking onset was defined as >1 full drink of alcohol. Findings Alcohol expectancies increased over age and the increase became more rapid following onset of drinking. The importance of genetic and environmental influences on SB scores varied with age and drinking status, such that variation prior to drinking onset was attributed solely to environmental influences, whereas all post-onset variation was attributed to genetic influences. Results did not differ significantly by sex. Conclusion Only environmental factors explain beliefs about the social and behavioral consequences of alcohol use prior to drinking onset, whereas genetic factors explain an increasing proportion of the variance in these beliefs after drinking onset. PMID:25586461

  18. Genetic and environmental influences on the relationship between flow proneness, locus of control and behavioral inhibition.

    PubMed

    Mosing, Miriam A; Pedersen, Nancy L; Cesarini, David; Johannesson, Magnus; Magnusson, Patrik K E; Nakamura, Jeanne; Madison, Guy; Ullén, Fredrik

    2012-01-01

    Flow is a psychological state of high but subjectively effortless attention that typically occurs during active performance of challenging tasks and is accompanied by a sense of automaticity, high control, low self-awareness, and enjoyment. Flow proneness is associated with traits and behaviors related to low neuroticism such as emotional stability, conscientiousness, active coping, self-esteem and life satisfaction. Little is known about the genetic architecture of flow proneness, behavioral inhibition and locus of control--traits also associated with neuroticism--and their interrelation. Here, we hypothesized that individuals low in behavioral inhibition and with an internal locus of control would be more likely to experience flow and explored the genetic and environmental architecture of the relationship between the three variables. Behavioral inhibition and locus of control was measured in a large population sample of 3,375 full twin pairs and 4,527 single twins, about 26% of whom also scored the flow proneness questionnaire. Findings revealed significant but relatively low correlations between the three traits and moderate heritability estimates of .41, .45, and .30 for flow proneness, behavioral inhibition, and locus of control, respectively, with some indication of non-additive genetic influences. For behavioral inhibition we found significant sex differences in heritability, with females showing a higher estimate including significant non-additive genetic influences, while in males the entire heritability was due to additive genetic variance. We also found a mainly genetically mediated relationship between the three traits, suggesting that individuals who are genetically predisposed to experience flow, show less behavioral inhibition (less anxious) and feel that they are in control of their own destiny (internal locus of control). We discuss that some of the genes underlying this relationship may include those influencing the function of dopaminergic neural

  19. Genetic and Environmental Influences on the Relationship between Flow Proneness, Locus of Control and Behavioral Inhibition

    PubMed Central

    Mosing, Miriam A.; Pedersen, Nancy L.; Cesarini, David; Johannesson, Magnus; Magnusson, Patrik K. E.; Nakamura, Jeanne; Madison, Guy; Ullén, Fredrik

    2012-01-01

    Flow is a psychological state of high but subjectively effortless attention that typically occurs during active performance of challenging tasks and is accompanied by a sense of automaticity, high control, low self-awareness, and enjoyment. Flow proneness is associated with traits and behaviors related to low neuroticism such as emotional stability, conscientiousness, active coping, self-esteem and life satisfaction. Little is known about the genetic architecture of flow proneness, behavioral inhibition and locus of control – traits also associated with neuroticism – and their interrelation. Here, we hypothesized that individuals low in behavioral inhibition and with an internal locus of control would be more likely to experience flow and explored the genetic and environmental architecture of the relationship between the three variables. Behavioral inhibition and locus of control was measured in a large population sample of 3,375 full twin pairs and 4,527 single twins, about 26% of whom also scored the flow proneness questionnaire. Findings revealed significant but relatively low correlations between the three traits and moderate heritability estimates of .41, .45, and .30 for flow proneness, behavioral inhibition, and locus of control, respectively, with some indication of non-additive genetic influences. For behavioral inhibition we found significant sex differences in heritability, with females showing a higher estimate including significant non-additive genetic influences, while in males the entire heritability was due to additive genetic variance. We also found a mainly genetically mediated relationship between the three traits, suggesting that individuals who are genetically predisposed to experience flow, show less behavioral inhibition (less anxious) and feel that they are in control of their own destiny (internal locus of control). We discuss that some of the genes underlying this relationship may include those influencing the function of dopaminergic

  20. Behaviors of Polymer Additives Under EHL and Influences of Interactions Between Additives on Friction Modification

    NASA Technical Reports Server (NTRS)

    Sakurai, T.

    1984-01-01

    Polymer additives have become requisite for the formulation of multigrade engine oils. The behavior of polymethacrylate (PMA)-thickened oils as lubricants in concentrated contacts under nominal rolling and pure sliding conditions was investigated by conventional optical interferometry. The PMA thickened oils behaved differently from the base oil in the formation of elastohydrodynamic (EHL) films. The higher the elastohydrodynamic molecular weight of the PMA contained in the lubricant, the thinner was the oil film under EHL conditions. The film thickness of shear-degraded PMA-thickened oils was also investigated. The behavior of graphite particles dispersed in both the base oil and the PMA-thickened oil was studied under pure sliding by taking photomicrographs. Many kinds of additives are contained in lubricating oil and the interactions between additives are considered. The interactions of zinc-organodithiophosphates (ZDP) with other additives is discussed.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. LISREL Modeling: Genetic and Environmental Influences on IQ Revisited.

    ERIC Educational Resources Information Center

    Chipuer, Heather M.; And Others

    1990-01-01

    A model-fitting analysis of the covariance structure of an intelligence quotient (IQ) data set is reported using a model that considers additive and nonadditive genetic parameters and shared and nonshared environment parameters that permit different estimates for different types of relatives. The use of LISREL for such purposes is reviewed. (SLD)

  7. Analysis of Genetic and Non-Genetic Factors Influencing Timing and Time Perception.

    PubMed

    Bartholomew, Alex J; Meck, Warren H; Cirulli, Elizabeth T

    2015-01-01

    Performance on different psychophysical tasks measuring the sense of time indicates a large amount of individual variation in the accuracy and precision of timing in the hundredths of milliseconds-to-minutes range. Quantifying factors with an influence on timing is essential to isolating a biological (genetic) contribution to the perception and estimation of time. In the largest timing study to date, 647 participants completed a duration-discrimination task in the sub-second range and a time-production task in the supra-second range. We confirm the stability of a participant's time sense across multiple sessions and substantiate a modest sex difference on time production. Moreover, we demonstrate a strong correlation between performance on a standardized cognitive battery and performance in both duration-discrimination and time-production tasks; we further show that performance is uncorrelated with age after controlling for general intelligence. Additionally, we find an effect of ethnicity on time sense, with African Americans and possibly Hispanics in our cohort differing in accuracy and precision from other ethnic groups. Finally, a preliminary genome-wide association and exome chip study was performed on 148 of the participants, ruling out the possibility for a single common variant or groups of low-frequency coding variants within a single gene to explain more than ~18% of the variation in the sense of time. PMID:26641268

  8. Analysis of Genetic and Non-Genetic Factors Influencing Timing and Time Perception

    PubMed Central

    Bartholomew, Alex J.; Meck, Warren H.; Cirulli, Elizabeth T.

    2015-01-01

    Performance on different psychophysical tasks measuring the sense of time indicates a large amount of individual variation in the accuracy and precision of timing in the hundredths of milliseconds-to-minutes range. Quantifying factors with an influence on timing is essential to isolating a biological (genetic) contribution to the perception and estimation of time. In the largest timing study to date, 647 participants completed a duration-discrimination task in the sub-second range and a time-production task in the supra-second range. We confirm the stability of a participant’s time sense across multiple sessions and substantiate a modest sex difference on time production. Moreover, we demonstrate a strong correlation between performance on a standardized cognitive battery and performance in both duration-discrimination and time-production tasks; we further show that performance is uncorrelated with age after controlling for general intelligence. Additionally, we find an effect of ethnicity on time sense, with African Americans and possibly Hispanics in our cohort differing in accuracy and precision from other ethnic groups. Finally, a preliminary genome-wide association and exome chip study was performed on 148 of the participants, ruling out the possibility for a single common variant or groups of low-frequency coding variants within a single gene to explain more than ~18% of the variation in the sense of time. PMID:26641268

  9. 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.

  10. 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

  11. Influence of bio-additives on combustion of liquid fuels

    NASA Astrophysics Data System (ADS)

    Patsch, Marek; Durčanský, Peter

    2016-06-01

    In this contribution there are analyses of the course of the pressure curves, which were measured in the diesel engine MD UR IV, which is often used in cogeneration units. The results of the analyses confront the properties and quality of fuels. The measuring was realized with a constant rotation speed of the engine and by using different fuels. The fuels were pure diesel fuels and diesel fuel with bio-additives of hydrogenate RO (rape oil), FAME, and bioethanol.

  12. The influence of additives on rheological properties of limestone slurry

    NASA Astrophysics Data System (ADS)

    Jaworska, B.; Bartosik, A.

    2014-08-01

    Limestone slurry appears in the lime production process as the result of rinsing the processed material. It consists of particles with diameter smaller than 2 mm and the water that is a carrier of solid fraction. Slurry is directed to the settling tank, where the solid phase sediments and the excess water through the transfer system is recovered for re-circulation. Collected at the bottom of the tank sludge is deposited in a landfill located on the premises. Rheological properties of limestone slurry hinder its further free transport in the pipeline due to generated flow resistance. To improve this state of affairs, chemical treatment of drilling fluid, could be applied, of which the main task is to give the slurry properties suitable for the conditions encountered in hydrotransport. This treatment consists of applying chemical additives to slurry in sufficient quantity. Such additives are called as deflocculants or thinners or dispersants, and are chemical compounds which added to aqueous solution are intended to push away suspended particles from each other. The paper presents the results of research allowing reduction of shear stress in limestone slurry. Results demonstrate rheological properties of limestone slurry with and without the addition of modified substances which causes decrease of slurry viscosity, and as a consequence slurry shear stress for adopted shear rate. Achieving the desired effects increases the degree of dispersion of the solid phase suspended in the carrier liquid and improving its ability to smooth flow with decreased friction.

  13. Influence of MTBE addition into gasoline on automotive exhaust emissions

    NASA Astrophysics Data System (ADS)

    Poulopoulos, S.; Philippopoulos, C.

    The effect of methyl-t-butyl ether (MTBE) addition into gasoline on the exhaust emissions from internal combustion engines was studied. A four-cylinder OPEL 1.6 l engine equipped with a hydraulic brake dynamometer was used in all the experiments. Fuels containing 0.0-11.0% MTBE were used in a wide range of engine operations, and the exhaust gases were analyzed for CO, HC (total unburned hydrocarbons, methane, ethylene) and MTBE, before and after their catalytic treatment by a three-way catalytic converter. The addition of MTBE into gasoline resulted in a decrease in CO and HC emissions only at high engine loading. During cold-start up of the engine, MTBE, HC, CO emissions were significant and increased with MTBE addition into fuel. At the catalytic converter outlet MTBE was detected when its concentration in fuels was greater than 8% and only as long as the catalytic converter operates at low temperatures. Methane and ethylene emissions were comparable for all fuels tested at engine outlet, but methane emissions remained almost at the same level while ethylene emissions were significantly decreased by the catalytic converter.

  14. 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

  15. Genetic and environmental influences on food preferences in adolescence12

    PubMed Central

    Herle, Moritz; Shakeshaft, Nicholas

    2016-01-01

    Background: Food preferences vary substantially among adults and children. Twin studies have established that genes and aspects of the shared family environment both play important roles in shaping children’s food preferences. The transition from childhood to adulthood is characterized by large gains in independence, but the relative influences of genes and the environment on food preferences in late adolescence are unknown. Objective: The aim of this study was to quantify the contribution of genetic and environmental influences on food preferences in older adolescents. Design: Participants were 2865 twins aged 18–19 y from the TEDS (Twins Early Development Study), a large population-based cohort of British twins born during 1994–1996. Food preferences were measured by using a self-report questionnaire of 62 individual foods. Food items were categorized into 6 food groups (fruit, vegetables, meat or fish, dairy, starch foods, and snacks) by using factor analysis. Maximum likelihood structural equation modeling established genetic and environmental contributions to variations in preferences for each food group. Results: Genetic factors influenced a significant and substantial proportion of the variation in preference scores of all 6 food groups: vegetables (0.54; 95% CI: 0.47, 0.59), fruit (0.49; 95% CI: 0.43, 0.55), starchy foods (0.32; 95% CI: 0.24, 0.39), meat or fish (0.44; 95% CI: 0.38, 0.51), dairy (0.44; 95% CI: 0.37, 0.50), and snacks (0.43; 95% CI: 0.36, 0.49). Aspects of the environment that are not shared by 2 twins in a family explained all of the remaining variance in food preferences. Conclusions: Food preferences had a moderate genetic basis in late adolescence, in keeping with findings in children. However, by this older age, the influence of the shared family environment had disappeared, and only aspects of the environment unique to each individual twin influenced food preferences. This finding suggests that shared environmental experiences

  16. 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

  17. Genetic and environmental influences on depressive symptoms in Chinese adolescents.

    PubMed

    Chen, Jie; Li, Xinying; Natsuaki, Misaki N; Leve, Leslie D; Harold, Gordon T

    2014-01-01

    Adolescent depression is common and has become a major public health concern in China, yet little research has examined the etiology of depression in Chinese adolescents. In the present study, genetic and environmental influences on Chinese adolescent depressive symptoms were investigated in 1,181 twin pairs residing in Beijing, China (ages 11-19 years). Child- and parent-versions of the children's depression inventory were used to measure adolescents' depressive symptoms. For self-reports, genetic factors, shared environmental factors, and non-shared environmental factors accounted for 50, 5, and 45 % of the variation in depressive symptoms, respectively; for parent-reports, genetic factors, shared environmental factors, and non-shared environmental factors accounted for 51, 18, and 31 % of the variation, respectively. These estimates are generally consistent with previous findings in Western adolescents, supporting the cross-cultural generalizability of etiological model of adolescent depression. Neither qualitative nor quantitative sex differences were found in the etiological model. Future studies are needed to investigate how genes and environments work together (gene-environment interaction, gene-environment correlation) to influence depression in Chinese adolescents. PMID:24311200

  18. Influence of sewage sludge addition on coal ash fusion temperatures

    SciTech Connect

    M. Belen Folgueras; R. Maria Diaz; Jorge Xiberta; M. Purificacion Garcia; J. Juan Pis

    2005-12-01

    The ash fusion characteristics of three types of bituminous coal (A, B, and C), one type of sewage sludge (W), and the corresponding coal-sewage sludge blends (10 and 50 wt % of sludge) were studied. The ash fusibility temperatures of samples in oxidizing atmosphere were measured, and their chemical and mineralogical compositions were determined. The addition of sludge to coal in certain proportions produces blends whose ashes have lower fusibility temperatures than those of coal and sludge. This is related to the differences in chemical composition and modes of elemental combination in both types of materials. The main differences are associated to the elements P, Fe, and Ca. As the sludge is much richer in Ca than the coals, the compositions of the blend ashes pass through low-temperature eutectic regions of the ternary phase diagrams SiO{sub 2}-CaO-Al{sub 2}O{sub 3} and SiO{sub 2}-CaO-Fe{sub 2}O{sub 3}. As a result, for the sludge-coal blend ashes series (one for each coal), the relationships between ash fusibility temperatures and the percentage of sludge ash in blend ashes fit to second-order polynomial functions. The minima of these functions, as well as some sludge-coal blend ashes, are located in the above-mentioned low fusion regions. Differing from coal ashes, in the sludge and 50 wt % blend ashes, the minerals calcium ferrite, larnite, and chloroapatite were found. 17 refs., 6 figs., 6 tabs.

  19. 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

  20. Genetic Influences on Dynamic Complexity of Brain Oscillations

    PubMed Central

    Anokhin, Andrey P.; Müller, Viktor; Lindenberger, Ulman; Heath, Andrew C.; Myers, Erin

    2007-01-01

    Human electroencephalogram (EEG) consists of complex aperiodic oscillations that are assumed to indicate underlying neural dynamics such as the number and the degree of independence of oscillating neuronal networks. EEG complexity can be estimated using measures derived from non-linear dynamic systems theory. Variations in such measures have been shown to be associated with normal individual differences in cognition and some neuropsychiatric disorders. Despite the increasing use of EEG complexity measures for the study of normal and abnormal brain functioning, little is known about genetic and environmental influences on these measures. Using the pointwise dimension (PD2) algorithm, this study assessed heritability of EEG complexity at rest in a sample of 214 young female twins consisting of 51 monozygotic (MZ) and 56 dizygotic (DZ) pairs. In MZ twins, intrapair correlations were high and statistically significant; in DZ twins, correlations were substantially smaller. Genetic analyses using linear structural equation modeling revealed high and significant heritability of EEG complexity: 62–68 % in the eyes closed condition, and 46–60 % in the eyes open condition. Results suggest that individual differences in the complexity of resting electrocortical dynamics are largely determined by genetic factors. Neurophysiological mechanisms mediating genetic variation in EEG complexity may include the degree of structural connectivity and functional differentiation among cortical neuronal assemblies. PMID:16442730

  1. 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

  2. Genetic Polymorphisms Influence Cognition in Patients Undergoing Carotid Interventions.

    PubMed

    Hitchner, Elizabeth; Morrison, Doug; Liao, Phoebe; Rosen, Allyson; Zhou, Wei

    2016-09-01

    While carotid interventions help decrease the risk of stroke, nearly 40% of patients experience cognitive deterioration. Genetic polymorphism in apolipoprotein E (ApoE) and brain-derived neurotrophic factor (BDNF) have been implicated in cognitive impairment; however, it is unclear whether they may influence cognitive changes in patients undergoing carotid intervention. In this study, we seek to assess the role of genetic polymorphisms in carotid intervention-related cognitive change. Polymorphisms related to cognitive function were chosen for this preliminary analysis. Over 2 years, patients undergoing carotid interventions were prospectively recruited. Patients underwent neuropsychological testing 2 weeks prior to and at 1 month following their procedure. Saliva samples were collected for genetic analysis. Logistic regressions were used to identify associations between polymorphisms and cognitive measures. A total of 91 patients were included; all were male with an average age of 70 years. The majority of patients exhibited hypertension (95%) and a history of smoking (81%). Presence of ApoE 4 allele was associated with depression (p= 0.047). After correcting for age and genetic polymorphisms in BDNF and serotonin transporter (5-HTT), ApoE 4 allele was associated with depression (p= 0.044) and showed a trend with baseline cognitive impairment (p= 0.10). Age ≥ 70 years was associated with baseline cognitive impairment after adjusting for the three genetic polymorphisms (p= 0.03). Patients with ApoE 4 and BDNF A polymorphisms performed less well on the visual and verbal memory measures, respectively. Polymorphisms in ApoE and BDNF may provide insight on cognition in patients undergoing carotid interventions; however, the mechanism of this relationship remains unclear. PMID:27574384

  3. 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.

  4. 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.

  5. Assessment of the environmental and genetic factors influencing prevalence of metabolic syndrome in Saudi Arabia

    PubMed Central

    Gosadi, Ibrahim M.

    2016-01-01

    Metabolic syndrome (MS) is a combination of factors that increases the risk of cardiovascular atherosclerotic diseases including diabetes, obesity, dyslipidemia, and high blood pressure. Cardiovascular diseases are one of the leading causes of death in the adult Saudi population where the increase in cardiovascular-related mortality is augmented by the rise in the prevalence of MS. Metabolic syndrome is a multi-factorial disorder influenced by interactions between genetic and environmental components. This review aims to provide a comprehensive assessment of studied environmental and genetic factors explaining the prevalence of MS in the Kingdom of Saudi Arabia. Additionally, this review aims to illustrate factors related to the population genetics of Saudi Arabia, which might explain a proportion of the prevalence of MS. PMID:26739969

  6. Influence of landscape features on the microgeographic genetic structure of a resident songbird.

    PubMed

    Adams, R V; Lazerte, S E; Otter, K A; Burg, T M

    2016-08-01

    Landscape features influence individual dispersal and as a result can affect both gene flow and genetic variation within and between populations. The landscape of British Columbia, Canada, is already highly heterogeneous because of natural ecological and geological transitions, but disturbance from human-mediated processes has further fragmented continuous habitat, particularly in the central plateau region. In this study, we evaluated the effects of landscape heterogeneity on the genetic structure of a common resident songbird, the black-capped chickadee (Poecile atricapillus). Previous work revealed significant population structuring in British Columbia that could not be explained by physical barriers, so our aim was to assess the pattern of genetic structure at a microgeographic scale and determine the effect of different landscape features on genetic differentiation. A total of 399 individuals from 15 populations were genotyped for fourteen microsatellite loci revealing significant population structuring in this species. Individual- and population-based analyses revealed as many as nine genetic clusters with isolation in the north, the central plateau and the south. Moreover, a mixed modelling approach that accounted for non-independence of pairwise distance values revealed a significant effect of land cover and elevation resistance on genetic differentiation. These results suggest that barriers in the landscape influence dispersal which has led to the unexpectedly high levels of population isolation. Our study demonstrates the importance of incorporating landscape features when interpreting patterns of population differentiation. Despite taking a microgeographic approach, our results have opened up additional questions concerning the processes influencing dispersal and gene flow at the local scale. PMID:26905462

  7. [Influence of genetic factors on human sexual orientation. Review].

    PubMed

    Rodríguez-Larralde, Alvaro; Paradisi, Irene

    2009-09-01

    Human sexual orientation is a complex trait, influenced by several genes, experiential and sociocultural factors. These elements interact and produce a typical pattern of sexual orientation towards the opposite sex. Some exceptions exist, like bisexuality and homosexuality, which seem to be more frequent in males than females. Traditional methods for the genetic study of behavior multifactorial characteristics consist in detecting the presence of familial aggregation. In order to identify the importance of genetic and environmental factors in this aggregation, the concordance of the trait for monozygotic and dizygotic twins and for adopted sibs, reared together and apart, is compared. These types of studies have shown that familial aggregation is stronger for male than for female homosexuality. Based on the threshold method for multifactorial traits, and varying the frequency of homosexuality in the population between 4 and 10%, heritability estimates between 0.27 and 0.76 have been obtained. In 1993, linkage between homosexuality and chromosomal region Xq28 based on molecular approaches was reported. Nevertheless, this was not confirmed in later studies. Recently, a wide search of the genome has given significant or close to significant linkage values with regions 7q36, 8p12 and 10q26, which need to be studied more closely. Deviation in the proportion of X chromosome inactivation in mothers of homosexuals seems to favor the presence of genes related with sexual orientation in this chromosome. There is still much to be known about the genetics of human homosexuality. PMID:19961060

  8. 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

  9. Genetic and Environmental Influences on Negative Life Events from Late Childhood to Adolescence

    ERIC Educational Resources Information Center

    Johnson, Daniel P.; Rhee, Soo Hyun; Whisman, Mark A.; Corley, Robin P.; Hewitt, John K.

    2013-01-01

    This multiwave longitudinal study tested two quantitative genetic developmental models to examine genetic and environmental influences on exposure to negative dependent and independent life events. Participants (N = 457 twin pairs) completed measures of life events annually from ages 9 to 16. The same genetic factors influenced exposure to…

  10. Genetic and Environmental Influences on Individual Differences in Printed Word Recognition.

    ERIC Educational Resources Information Center

    Gayan, Javier; Olson, Richard K.

    2003-01-01

    Explored genetic and environmental etiologies of individual differences in printed word recognition and related skills in identical and fraternal twin 8- to 18-year-olds. Found evidence for moderate genetic influences common between IQ, phoneme awareness, and word-reading skills and for stronger IQ-independent genetic influences that were common…

  11. 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

  12. Biology, Genetics, and Environment: Underlying Factors Influencing Alcohol Metabolism.

    PubMed

    Wall, Tamara L; Luczak, Susan E; Hiller-Sturmhöfel, Susanne

    2016-01-01

    Gene variants encoding several of the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), are among the largest genetic associations with risk for alcohol dependence. Certain genetic variants (i.e., alleles)--particularly the ADH1B*2, ADH1B*3, ADH1C*1, and ALDH2*2 alleles--have been associated with lower rates of alcohol dependence. These alleles may lead to an accumulation of acetaldehyde during alcohol metabolism, which can result in heightened subjective and objective effects. The prevalence of these alleles differs among ethnic groups; ADH1B*2 is found frequently in northeast Asians and occasionally Caucasians, ADH1B*3 is found predominantly in people of African ancestry, ADH1C*1 varies substantially across populations, and ALDH2*2 is found almost exclusively in northeast Asians. Differences in the prevalence of these alleles may account at least in part for ethnic differences in alcohol consumption and alcohol use disorder (AUD). However, these alleles do not act in isolation to influence the risk of AUD. For example, the gene effects of ALDH2*2 and ADH1B*2 seem to interact. Moreover, other factors have been found to influence the extent to which these alleles affect a person's alcohol involvement, including developmental stage, individual characteristics (e.g., ethnicity, antisocial behavior, and behavioral undercontrol), and environmental factors (e.g., culture, religion, family environment, and childhood adversity). PMID:27163368

  13. 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

  14. 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

  15. Multi-taxa integrated landscape genetics for zoonotic infectious diseases: deciphering variables influencing disease emergence.

    PubMed

    Leo, Sarah S T; Gonzalez, Andrew; Millien, Virginie

    2016-05-01

    Zoonotic disease transmission systems involve sets of species interacting with each other and their environment. This complexity impedes development of disease monitoring and control programs that require reliable identification of spatial and biotic variables and mechanisms facilitating disease emergence. To overcome this difficulty, we propose a framework that simultaneously examines all species involved in disease emergence by integrating concepts and methods from population genetics, landscape ecology, and spatial statistics. Multi-taxa integrated landscape genetics (MTILG) can reveal how interspecific interactions and landscape variables influence disease emergence patterns. We test the potential of our MTILG-based framework by modelling the emergence of a disease system across multiple species dispersal, interspecific interaction, and landscape scenarios. Our simulations showed that both interspecific-dependent dispersal patterns and landscape characteristics significantly influenced disease spread. Using our framework, we were able to detect statistically similar inter-population genetic differences and highly correlated spatial genetic patterns that imply species-dependent dispersal. Additionally, species that were assigned coupled-dispersal patterns were affected to the same degree by similar landscape variables. This study underlines the importance of an integrated approach to investigating emergence of disease systems. MTILG is a robust approach for such studies and can identify potential avenues for targeted disease management strategies. PMID:27074898

  16. Heritable influences on amygdala and orbitofrontal cortex contribute to genetic variation in core dimensions of personality

    PubMed Central

    Lewis, G.J.; Panizzon, M.S.; Eyler, L.; Fennema-Notestine, C.; Chen, C.-H.; Neale, M.C.; Jernigan, T.L.; Lyons, M.J.; Dale, A.M.; Kremen, W.S.; Franz, C.E.

    2015-01-01

    While many studies have reported that individual differences in personality traits are genetically influenced, the neurobiological bases mediating these influences have not yet been well characterized. To advance understanding concerning the pathway from genetic variation to personality, here we examined whether measures of heritable variation in neuroanatomical size in candidate regions (amygdala and medial orbitofrontal cortex) were associated with heritable effects on personality. A sample of 486 middle-aged (mean = 55 years) male twins (complete MZ pairs = 120; complete DZ pairs = 84) underwent structural brain scans and also completed measures of two core domains of personality: positive and negative emotionality. After adjusting for estimated intracranial volume, significant phenotypic (rp) and genetic (rg) correlations were observed between left amygdala volume and positive emotionality (rp = .16, p < .01; rg = .23, p < .05, respectively). In addition, after adjusting for mean cortical thickness, genetic and nonshared-environmental correlations (re) between left medial orbitofrontal cortex thickness and negative emotionality were also observed (rg = .34, p < .01; re = −.19, p < .05, respectively). These findings support a model positing that heritable bases of personality are, at least in part, mediated through individual differences in the size of brain structures, although further work is still required to confirm this causal interpretation. PMID:25263286

  17. Influence of mom and dad: quantitative genetic models for maternal effects and genomic imprinting.

    PubMed

    Santure, Anna W; Spencer, Hamish G

    2006-08-01

    The expression of an imprinted gene is dependent on the sex of the parent it was inherited from, and as a result reciprocal heterozygotes may display different phenotypes. In contrast, maternal genetic terms arise when the phenotype of an offspring is influenced by the phenotype of its mother beyond the direct inheritance of alleles. Both maternal effects and imprinting may contribute to resemblance between offspring of the same mother. We demonstrate that two standard quantitative genetic models for deriving breeding values, population variances and covariances between relatives, are not equivalent when maternal genetic effects and imprinting are acting. Maternal and imprinting effects introduce both sex-dependent and generation-dependent effects that result in differences in the way additive and dominance effects are defined for the two approaches. We use a simple example to demonstrate that both imprinting and maternal genetic effects add extra terms to covariances between relatives and that model misspecification may over- or underestimate true covariances or lead to extremely variable parameter estimation. Thus, an understanding of various forms of parental effects is essential in correctly estimating quantitative genetic variance components. PMID:16751674

  18. Genetic Influences on Metabolite Levels: A Comparison across Metabolomic Platforms.

    PubMed

    Yet, Idil; Menni, Cristina; Shin, So-Youn; Mangino, Massimo; Soranzo, Nicole; Adamski, Jerzy; Suhre, Karsten; Spector, Tim D; Kastenmüller, Gabi; Bell, Jordana T

    2016-01-01

    Metabolomic profiling is a powerful approach to characterize human metabolism and help understand common disease risk. Although multiple high-throughput technologies have been developed to assay the human metabolome, no technique is capable of capturing the entire human metabolism. Large-scale metabolomics data are being generated in multiple cohorts, but the datasets are typically profiled using different metabolomics platforms. Here, we compared analyses across two of the most frequently used metabolomic platforms, Biocrates and Metabolon, with the aim of assessing how complimentary metabolite profiles are across platforms. We profiled serum samples from 1,001 twins using both targeted (Biocrates, n = 160 metabolites) and non-targeted (Metabolon, n = 488 metabolites) mass spectrometry platforms. We compared metabolite distributions and performed genome-wide association analyses to identify shared genetic influences on metabolites across platforms. Comparison of 43 metabolites named for the same compound on both platforms indicated strong positive correlations, with few exceptions. Genome-wide association scans with high-throughput metabolic profiles were performed for each dataset and identified genetic variants at 7 loci associated with 16 unique metabolites on both platforms. The 16 metabolites showed consistent genetic associations and appear to be robustly measured across platforms. These included both metabolites named for the same compound across platforms as well as unique metabolites, of which 2 (nonanoylcarnitine (C9) [Biocrates]/Unknown metabolite X-13431 [Metabolon] and PC aa C28:1 [Biocrates]/1-stearoylglycerol [Metabolon]) are likely to represent the same or related biochemical entities. The results demonstrate the complementary nature of both platforms, and can be informative for future studies of comparative and integrative metabolomics analyses in samples profiled on different platforms. PMID:27073872

  19. Genetic Influences on Metabolite Levels: A Comparison across Metabolomic Platforms

    PubMed Central

    Yet, Idil; Menni, Cristina; Shin, So-Youn; Mangino, Massimo; Soranzo, Nicole; Adamski, Jerzy; Suhre, Karsten; Spector, Tim D.

    2016-01-01

    Metabolomic profiling is a powerful approach to characterize human metabolism and help understand common disease risk. Although multiple high-throughput technologies have been developed to assay the human metabolome, no technique is capable of capturing the entire human metabolism. Large-scale metabolomics data are being generated in multiple cohorts, but the datasets are typically profiled using different metabolomics platforms. Here, we compared analyses across two of the most frequently used metabolomic platforms, Biocrates and Metabolon, with the aim of assessing how complimentary metabolite profiles are across platforms. We profiled serum samples from 1,001 twins using both targeted (Biocrates, n = 160 metabolites) and non-targeted (Metabolon, n = 488 metabolites) mass spectrometry platforms. We compared metabolite distributions and performed genome-wide association analyses to identify shared genetic influences on metabolites across platforms. Comparison of 43 metabolites named for the same compound on both platforms indicated strong positive correlations, with few exceptions. Genome-wide association scans with high-throughput metabolic profiles were performed for each dataset and identified genetic variants at 7 loci associated with 16 unique metabolites on both platforms. The 16 metabolites showed consistent genetic associations and appear to be robustly measured across platforms. These included both metabolites named for the same compound across platforms as well as unique metabolites, of which 2 (nonanoylcarnitine (C9) [Biocrates]/Unknown metabolite X-13431 [Metabolon] and PC aa C28:1 [Biocrates]/1-stearoylglycerol [Metabolon]) are likely to represent the same or related biochemical entities. The results demonstrate the complementary nature of both platforms, and can be informative for future studies of comparative and integrative metabolomics analyses in samples profiled on different platforms. PMID:27073872

  20. 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

  1. 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

  2. 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

  3. Genetic factors influencing the risk of multiple myeloma bone disease

    PubMed Central

    Johnson, D C; Weinhold, N; Mitchell, J; Chen, B; Stephens, O W; Försti, A; Nickel, J; Kaiser, M; Gregory, W A; Cairns, D; Jackson, G H; Hoffmann, P; Noethen, M M; Hillengass, J; Bertsch, U; Barlogie, B; Davis, F E; Hemminki, K; Goldschmidt, H; Houlston, R S; Morgan, G J

    2016-01-01

    A major complication of multiple myeloma (MM) is the development of osteolytic lesions, fractures and bone pain. To identify genetic variants influencing the development of MM bone disease (MBD), we analyzed MM patients of European ancestry (totaling 3774), which had been radiologically surveyed for MBD. Each patient had been genotyped for ~6 00 000 single-nucleotide polymorphisms with genotypes for six million common variants imputed using 1000 Genomes Project and UK10K as reference. We identified a locus at 8q24.12 for MBD (rs4407910, OPG/TNFRSF11B, odds ratio=1.38, P=4.09 × 10–9) and a promising association at 19q13.43 (rs74676832, odds ratio=1.97, P=9.33 × 10–7). Our findings demonstrate that germline variation influences MBD and highlights the importance of RANK/RANKL/OPG pathway in MBD development. These findings will contribute to the development of future strategies for prevention of MBD in the early precancerous phases of MM. PMID:26669972

  4. Factors influencing stakeholders attitudes toward genetically modified aedes mosquito.

    PubMed

    Amin, Latifah; Hashim, Hasrizul

    2015-06-01

    Dengue fever is a debilitating and infectious disease that could be life-threatening. It is caused by the dengue virus which affects millions of people in the tropical area. Currently, there is no cure for the disease as there is no vaccine available. Thus, prevention of the vector population using conventional methods is by far the main strategy but has been found ineffective. A genetically modified (GM) mosquito is among the favoured alternatives to curb dengue fever in Malaysia. Past studies have shown that development and diffusion of gene technology products depends heavily upon public acceptance. The purpose of this study is to identify the relevant factors influencing stakeholders' attitudes toward the GM Aedes mosquito and to analyse the relationships between all the factors using the structural equation model. A survey was carried out on 509 respondents from various stakeholder groups in the Klang Valley region of Malaysia. Results of the survey have confirmed that public perception towards complex issues such as gene technology should be seen as a multi-faceted process. The perceived benefit-perceived risk balance is very important in determining the most predominant predictor of attitudes toward a GM mosquito. In this study the stakeholders perceived the benefit of the GM mosquito as outweighing its risk, translating perceived benefit as the most important direct predictor of attitudes toward the GM mosquito. Trust in key players has a direct influence on attitudes toward the GM mosquito while moral concern exhibited an indirect influence through perceived benefits. Other factors such as attitudes toward technology and nature were also indirect predictors of attitudes toward the GM mosquito while religiosity and engagement did not exhibited any significant roles. The research findings serve as a useful database to understand public acceptance and the social construct of public attitudes towards the GM mosquito to combat dengue. PMID:24906652

  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 polymorphisms commonly influencing efficacy of diverse addictive substances].

    PubMed

    Nishizawa, Daisuke; Ikeda, Kazutaka

    2014-04-01

    Opioids, such as morphine and fentanyl, are widely used as effective analgesics for the treatment of acute and chronic pain. In addition, the opioid system has a key role in the rewarding effects of morphine, ethanol, cocaine and various other drugs. The authors have focused on G-protein-activated inwardly rectifying potassium (GIRK) channel subunits, GIRK2 and GIRK3, that are important molecules in opioid transmission, and found that the single-nucleotide polymorphisms (SNPs) within the GIRK2 and GIRK3 gene regions were significantly associated with postoperative requirements of analgesics including opioids in patients who underwent abdominal surgery and mRNA expression of these genes in postmortem specimens, one of which was also associated with vulnerability to methamphetamine (METH) dependence. Further, by conducting a multistage genome-wide association study (GWAS) in healthy subjects, the authors found that genetic polymorphisms within a linkage disequilibrium block that spans 2q33.3-2q34 were strongly associated with the requirements for postoperative opioid analgesics after painful cosmetic surgery. The C allele of the best candidate SNP, rs2952768, was associated with more analgesic requirements, and consistent results were obtained in patients who underwent abdominal surgery. In addition, carriers of the C allele in this SNP exhibited less vulnerability to severe drug dependence in patients with methamphetamine dependence, alcohol dependence, and eating disorders and a lower 'Reward Dependence score on a personality questionnaire in healthy subjects. Furthermore, the C/C genotype of this SNP was significantly associated with the elevated expression of a neighboring gene, CREB1. The results show that SNPs in this locus are the most potent genetic factors associated with human opioid sensitivity known to date, affecting both the efficacy of opioid analgesics and liability to severe substance dependence. These outcomes provide valuable information for the

  8. 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…

  9. Is the Child "Father of the Man"? Evaluating the Stability of Genetic Influences across Development

    ERIC Educational Resources Information Center

    Ronald, Angelica

    2011-01-01

    This selective review considers findings in genetic research that have shed light on how genes operate across development. We will address the question of whether the child is "father of the Man" from a genetic perspective. In other words, do the same genetic influences affect the same traits across development? Using a "taster menu" approach and…

  10. Human longevity is influenced by many genetic variants: evidence from 75,000 UK Biobank participants.

    PubMed

    Pilling, Luke C; Atkins, Janice L; Bowman, Kirsty; Jones, Samuel E; Tyrrell, Jessica; Beaumont, Robin N; Ruth, Katherine S; Tuke, Marcus A; Yaghootkar, Hanieh; Wood, Andrew R; Freathy, Rachel M; Murray, Anna; Weedon, Michael N; Xue, Luting; Lunetta, Kathryn; Murabito, Joanne M; Harries, Lorna W; Robine, Jean-Marie; Brayne, Carol; Kuchel, George A; Ferrucci, Luigi; Frayling, Timothy M; Melzer, David

    2016-03-01

    Variation in human lifespan is 20 to 30% heritable in twins but few genetic variants have been identified. We undertook a Genome Wide Association Study (GWAS) using age at death of parents of middle-aged UK Biobank participants of European decent (n=75,244 with father's and/or mother's data, excluding early deaths). Genetic risk scores for 19 phenotypes (n=777 proven variants) were also tested. In GWAS, a nicotine receptor locus(CHRNA3, previously associated with increased smoking and lung cancer) was associated with fathers' survival. Less common variants requiring further confirmation were also identified. Offspring of longer lived parents had more protective alleles for coronary artery disease, systolic blood pressure, body mass index, cholesterol and triglyceride levels, type-1 diabetes, inflammatory bowel disease and Alzheimer's disease. In candidate analyses, variants in the TOMM40/APOE locus were associated with longevity, but FOXO variants were not. Associations between extreme longevity (mother >=98 years, fathers >=95 years, n=1,339) and disease alleles were similar, with an additional association with HDL cholesterol (p=5.7x10-3). These results support a multiple protective factors model influencing lifespan and longevity (top 1% survival) in humans, with prominent roles for cardiovascular-related pathways. Several of these genetically influenced risks, including blood pressure and tobacco exposure, are potentially modifiable. PMID:27015805

  11. Host Genetic Background Strongly Influences the Response to Influenza A Virus Infections

    PubMed Central

    Srivastava, Barkha; Błażejewska, Paulina; Heßmann, Manuela; Bruder, Dunja; Geffers, Robert; Mauel, Susanne; Gruber, Achim D.; Schughart, Klaus

    2009-01-01

    The genetic make-up of the host has a major influence on its response to combat pathogens. For influenza A virus, several single gene mutations have been described which contribute to survival, the immune response and clearance of the pathogen by the host organism. Here, we have studied the influence of the genetic background to influenza A H1N1 (PR8) and H7N7 (SC35M) viruses. The seven inbred laboratory strains of mice analyzed exhibited different weight loss kinetics and survival rates after infection with PR8. Two strains in particular, DBA/2J and A/J, showed very high susceptibility to viral infections compared to all other strains. The LD50 to the influenza virus PR8 in DBA/2J mice was more than 1000-fold lower than in C57BL/6J mice. High susceptibility in DBA/2J mice was also observed after infection with influenza strain SC35M. In addition, infected DBA/2J mice showed a higher viral load in their lungs, elevated expression of cytokines and chemokines, and a more severe and extended lung pathology compared to infected C57BL/6J mice. These findings indicate a major contribution of the genetic background of the host to influenza A virus infections. The overall response in highly susceptible DBA/2J mice resembled the pathology described for infections with the highly virulent influenza H1N1-1918 and newly emerged H5N1 viruses. PMID:19293935

  12. Human longevity is influenced by many genetic variants: evidence from 75,000 UK Biobank participants

    PubMed Central

    Pilling, Luke C.; Atkins, Janice L.; Bowman, Kirsty; Jones, Samuel E.; Tyrrell, Jessica; Beaumont, Robin N.; Ruth, Katherine S.; Tuke, Marcus A.; Yaghootkar, Hanieh; Wood, Andrew R.; Freathy, Rachel M.; Murray, Anna; Weedon, Michael N.; Xue, Luting; Lunetta, Kathryn; Murabito, Joanne M.; Harries, Lorna W.; Robine, Jean-Marie; Brayne, Carol; Kuchel, George A.; Ferrucci, Luigi; Frayling, Timothy M.; Melzer, David

    2016-01-01

    Variation in human lifespan is 20 to 30% heritable in twins but few genetic variants have been identified. We undertook a Genome Wide Association Study (GWAS) using age at death of parents of middle-aged UK Biobank participants of European decent (n=75,244 with father's and/or mother's data, excluding early deaths). Genetic risk scores for 19 phenotypes (n=777 proven variants) were also tested. In GWAS, a nicotine receptor locus (CHRNA3, previously associated with increased smoking and lung cancer) was associated with fathers' survival. Less common variants requiring further confirmation were also identified. Offspring of longer lived parents had more protective alleles for coronary artery disease, systolic blood pressure, body mass index, cholesterol and triglyceride levels, type-1 diabetes, inflammatory bowel disease and Alzheimer's disease. In candidate analyses, variants in the TOMM40/APOE locus were associated with longevity, but FOXO variants were not. Associations between extreme longevity (mother >=98 years, fathers >=95 years, n=1,339) and disease alleles were similar, with an additional association with HDL cholesterol (p=5.7×10-3). These results support a multiple protective factors model influencing lifespan and longevity (top 1% survival) in humans, with prominent roles for cardiovascular-related pathways. Several of these genetically influenced risks, including blood pressure and tobacco exposure, are potentially modifiable. PMID:27015805

  13. Choice of Reading Comprehension Test Influences the Outcomes of Genetic Analyses

    ERIC Educational Resources Information Center

    Betjemann, Rebecca S.; Keenan, Janice M.; Olson, Richard K.; DeFries, John C.

    2011-01-01

    Does the choice of test for assessing reading comprehension influence the outcome of genetic analyses? A twin design compared two types of reading comprehension tests classified as primarily associated with word decoding (RC-D) or listening comprehension (RC-LC). For both types of tests, the overall genetic influence is high and nearly identical.…

  14. Nitrogen Addition and Warming Independently Influence the Belowground Micro-Food Web in a Temperate Steppe

    PubMed Central

    Li, Qi; Bai, Huahua; Liang, Wenju; Xia, Jianyang; Wan, Shiqiang; van der Putten, Wim H.

    2013-01-01

    Climate warming and atmospheric nitrogen (N) deposition are known to influence ecosystem structure and functioning. However, our understanding of the interactive effect of these global changes on ecosystem functioning is relatively limited, especially when it concerns the responses of soils and soil organisms. We conducted a field experiment to study the interactive effects of warming and N addition on soil food web. The experiment was established in 2006 in a temperate steppe in northern China. After three to four years (2009–2010), we found that N addition positively affected microbial biomass and negatively influenced trophic group and ecological indices of soil nematodes. However, the warming effects were less obvious, only fungal PLFA showed a decreasing trend under warming. Interestingly, the influence of N addition did not depend on warming. Structural equation modeling analysis suggested that the direct pathway between N addition and soil food web components were more important than the indirect connections through alterations in soil abiotic characters or plant growth. Nitrogen enrichment also affected the soil nematode community indirectly through changes in soil pH and PLFA. We conclude that experimental warming influenced soil food web components of the temperate steppe less than N addition, and there was little influence of warming on N addition effects under these experimental conditions. PMID:23544140

  15. Genetic evidence for chromosome 4 loci influencing learning and memory.

    PubMed

    Anselmi, Mayara; Correa, Fernanda Junkes; Santos, José Ronaldo; Silva, Anatildes Feitosa; Cunha, João Antônio; Leão, Anderson Henrique Figueiredo; Campêlo, Clarissa Loureiro Chagas; Ribeiro, Alessandra Mussi; Silva, Regina Helena; Izídio, Geison Souza

    2016-05-01

    The Lewis (LEW) and SHR (Spontaneously Hypertensive Rats) inbred rat strains differ in several anxiety/emotionality and learning/memory-related behaviors. We aimed to search quantitative trait locus (QTL) that influence these behaviors and confirm their effects in a congenic rat strain SLA16 (SHR.LEW.Anxrr16). LEW females and SHR males were intercrossed to produce F2 rats (96/sex), which were all tested in the plus-maze discriminative avoidance task (PMDAT), open-field (OF), object recognition (OR), spontaneous alternation (SA) and fear conditioning (FC). All animals were genotyped for microsatellite markers located on chromosome (Chr) 4. Behavioral and genotypic data were used to perform factor and QTL analyses. Also, to confirm the QTL effects, we tested male and female SLA16 rats and their isogenic control SHR in the same behavioral tests. A factor analysis of the F2 population revealed a correlation between anxiety/emotionality related behaviors and learning/memory in both sexes. QTL analysis revealed two significant QTL in males and three in females, on behavioral parameters in the PMDAT, OF and FC. Four QTL found herein were confirmed in SLA16 rats. The SLA16 strain displayed lower levels of anxiety/emotionality, higher locomotor activity and deficits in learning/memory in comparison with SHR strain. The Chr 4 contains genes influencing anxiety/emotionality and learning/memory behaviors and the SLA16 strain represents a valuable tool in the search for them. The use of the SLA16 strain as a genetic model for studying behavioral phenomena and their implications for psychiatric disorders are discussed. PMID:27044679

  16. Genetic background strongly influences the severity of glomerulosclerosis in mice.

    PubMed

    Nishino, Tomohiro; Sasaki, Nobuya; Nagasaki, Ken-Ichi; Ahmad, Zulkifli; Agui, Takashi

    2010-10-01

    The ICGN mouse strain is a glomerulosclerosis (GS) model that shows characteristic proteinuria, podocyte morphological abnormalities and increased extracellular matrix accumulation in the glomeruli, which are the final common pathology associated with a variety of kidney diseases leading to end-stage renal failure. Previously, we performed a quantitative trait locus (QTL) analysis to identify the causative genes for GS in ICGN mice and found the deletion mutation of the tensin2 (Tns2) gene that creates both a premature stop codon and dramatically decreases mRNA expression levels within the region of the major QTL (this mutation was designated Tns2(nep)). The severity of GS varies considerably in humans and other animals, indicating the influence of several genes controlling the disease phenotype. In this study, to identify the modifier/resistant gene(s) for GS, we produced congenic strains carrying the Tns2(nep) mutation on the C57BL/6J (B6) genetic background and analyzed GS severity. Interestingly, the B6 congenic mice exhibited milder phenotypes than the ICGN strain mice. The results suggest that B6 mice have a modifier(s) of GS resistance. Therefore, identification of the modifier loci in B6 mice will provide important new information regarding gene interactions controlling GS. PMID:20484839

  17. Discovery of a Novel Seminal Fluid Microbiome and Influence of Estrogen Receptor Alpha Genetic Status

    PubMed Central

    Javurek, Angela B.; Spollen, William G.; Ali, Amber M. Mann; Johnson, Sarah A.; Lubahn, Dennis B.; Bivens, Nathan J.; Bromert, Karen H.; Ellersieck, Mark R.; Givan, Scott A.; Rosenfeld, Cheryl S.

    2016-01-01

    Bacteria harbored in the male reproductive system may influence reproductive function and health of the male and result in developmental origins of adult health and disease (DOHaD) effects in his offspring. Such effects could be due to the seminal fluid, which is slightly basic and enriched with carbohydrates; thereby, creating an ideal habitat for microbes or a potential seminal fluid microbiome (SFM). Using wild-type (WT) and estrogen receptor-alpha (ESR1) knockout (KO) male mice, we describe a unique SFM whose inhabitants differ from gut microbes. The bacterial composition of the SFM is influenced according to whether mice have functional Esr1 genes. Propionibacterium acnes, causative agent of chronic prostatitis possibly culminating in prostate cancer, is reduced in SFM of ESR1 KO compared to WT mice (P ≤ 0.0007). In certain genetic backgrounds, WT mice show a greater incidence of prostate cancer than ESR1 KO, which may be due to increased abundance of P. acnes. Additionally, select gut microbiome residents in ESR1 KO males, such as Lachnospiraceae and Christensenellaceae, might contribute to previously identified phenotypes, especially obesity, in these mutant mice. Understanding how genetics and environmental factors influence the SFM may provide the next frontier in male reproductive disorders and possibly paternal-based DOHaD diseases. PMID:26971397

  18. T cells in asthma: influences of genetics, environment, and T-cell plasticity.

    PubMed

    Lloyd, Clare M; Saglani, Sejal

    2013-05-01

    Asthma is classically considered the archetypal T(H)2 disease, with increased circulating IgE levels and eosinophilic inflammation being caused by increased levels of T(H)2-type cytokines. However, this paradigm has been challenged because of the realization that strategies designed to suppress T(H)2 function are not effective for all patients. The clinical phenotype of asthma is notoriously heterogeneous and is affected by genetic and environmental exposures in addition to interactions between airway structural cells, including epithelial cells, and the immune system, as well as contributions from cells other than T(H)2 cells. A combination of genetic and environmental factors is thought to influence whether inflammation resolves or progresses, and the pulmonary epithelium is increasingly recognized to play a key role in this process. This complex interplay has made it increasingly apparent that immune responses are tailored to the individual patient and determined by the weight of each influence, and thus the label of asthma as a T(H)2 disease is too conservative. Indeed, an important concept that needs to be addressed, both in animal models and clinically, is that of T-cell plasticity and how lymphocytic responses are determined by environmental influences. PMID:23541326

  19. Discovery of a Novel Seminal Fluid Microbiome and Influence of Estrogen Receptor Alpha Genetic Status.

    PubMed

    Javurek, Angela B; Spollen, William G; Ali, Amber M Mann; Johnson, Sarah A; Lubahn, Dennis B; Bivens, Nathan J; Bromert, Karen H; Ellersieck, Mark R; Givan, Scott A; Rosenfeld, Cheryl S

    2016-01-01

    Bacteria harbored in the male reproductive system may influence reproductive function and health of the male and result in developmental origins of adult health and disease (DOHaD) effects in his offspring. Such effects could be due to the seminal fluid, which is slightly basic and enriched with carbohydrates; thereby, creating an ideal habitat for microbes or a potential seminal fluid microbiome (SFM). Using wild-type (WT) and estrogen receptor-alpha (ESR1) knockout (KO) male mice, we describe a unique SFM whose inhabitants differ from gut microbes. The bacterial composition of the SFM is influenced according to whether mice have functional Esr1 genes. Propionibacterium acnes, causative agent of chronic prostatitis possibly culminating in prostate cancer, is reduced in SFM of ESR1 KO compared to WT mice (P ≤ 0.0007). In certain genetic backgrounds, WT mice show a greater incidence of prostate cancer than ESR1 KO, which may be due to increased abundance of P. acnes. Additionally, select gut microbiome residents in ESR1 KO males, such as Lachnospiraceae and Christensenellaceae, might contribute to previously identified phenotypes, especially obesity, in these mutant mice. Understanding how genetics and environmental factors influence the SFM may provide the next frontier in male reproductive disorders and possibly paternal-based DOHaD diseases. PMID:26971397

  20. 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

  1. Genetic and environmental influences on writing and their relations to language and reading.

    PubMed

    Olson, Richard K; Hulslander, Jacqueline; Christopher, Micaela; Keenan, Janice M; Wadsworth, Sally J; Willcutt, Erik G; Pennington, Bruce F; DeFries, John C

    2013-04-01

    Identical and fraternal twins (N=540, age 8 to 18 years) were tested on three different measures of writing (Woodcock-Johnson III Tests of Achievement-Writing Samples and Writing Fluency; Handwriting Copy from the Group Diagnostic Reading and Aptitude Achievement Tests), three different language skills (phonological awareness, rapid naming, and vocabulary), and three different reading skills (word recognition, spelling, and reading comprehension). Substantial genetic influence was found on two of the writing measures, writing samples and handwriting copy, and all of the language and reading measures. Shared environment influences were generally not significant, except for Vocabulary. Non-shared environment estimates, including measurement error, were significant for all variables. Genetic influences among the writing measures were significantly correlated (highest between the speeded measures writing fluency and handwriting copy), but there were also significant independent genetic influences between copy and samples and between fluency and samples. Genetic influences on writing were significantly correlated with genetic influences on all of the language and reading skills, but significant independent genetic influences were also found for copy and samples, whose genetic correlations were significantly less than 1.0 with the reading and language skills. The genetic correlations varied significantly in strength depending on the overlap between the writing, language, and reading task demands. We discuss implications of our results for education, limitations of the study, and new directions for research on writing and its relations to language and reading. PMID:21842316

  2. 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

  3. 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

  4. Developmental structure of genetic influences on antisocial behavior across childhood and adolescence.

    PubMed

    Van Hulle, Carol A; Waldman, Irwin D; D'Onofrio, Brian M; Rodgers, Joseph Lee; Rathouz, Paul J; Lahey, Benjamin B

    2009-11-01

    It is necessary to determine if causal influences on developing antisocial behavior change with age to guide both research and theory on its origins. The extent to which the same genetic factors influence antisocial behavior across 4-17 years of age was estimated using 2,482 sibling pairs of varying genetic relatedness. Assessments of antisocial behavior by mothers (4-9 years), mothers and youth (10-13 years), and youth (14-17 years) reflected the changing validity of informants across development. Genetic influences on antisocial behavior at 14-17 years were entirely shared with those on antisocial behavior at 10-13 years according to both informants. Genetic influences on antisocial behavior at 14-17 years were distinct from those at 4-9 years, however. These age differences in genetic influences cannot be fully distinguished from informant differences across age, but the present findings indicate that youth reported to be persistently antisocial during childhood and adolescence are influenced by one set of genetic factors influencing parent-report conduct problems in childhood and a second set of genetic influences on youth-reported delinquency that come into play around the time of the pubertal transition. PMID:19899841

  5. Developmental Structure of Genetic Influences on Antisocial Behavior Across Childhood and Adolescence

    PubMed Central

    Van Hulle, Carol A.; Waldman, Irwin D.; D’Onofrio, Brian M.; Rodgers, Joseph Lee; Rathouz, Paul J.; Lahey, Benjamin B.

    2010-01-01

    It is necessary to determine if causal influences on developing antisocial behavior change with age to guide both research and theory on its origins. We estimated the extent to which the same genetic factors influence antisocial behavior across 4–17 years of age using 2,482 sibling pairs of varying genetic relatedness. Assessments of antisocial behavior reflected the changing validity of informants across development: Mothers (4–9 years), mothers and youth (10–13 years), and youth (14–17 years). Genetic influences on antisocial behavior at 14–17 years were entirely shared with those on antisocial behavior at 10–13 years according to both informants. Genetic influences on antisocial behavior at 14–17 years were distinct from those at 4–9 years, however. These age differences in genetic influences cannot be fully distinguished from informant differences across age, but the present findings indicate that youth reported to be persistently antisocial during childhood and adolescence are influenced by one set of genetic factors influencing parent-report conduct problems in childhood and a second set of genetic influences on youth-reported delinquency that come into play around the time of the pubertal transition. PMID:19899841

  6. 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...

  7. 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...

  8. 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...

  9. 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...

  10. Influence of Parental Depressive Symptoms on Adopted Toddler Behaviors: An Emerging Developmental Cascade of Genetic and Environmental Effects

    PubMed Central

    Pemberton, Caroline K.; Neiderhiser, Jenae M.; Leve, Leslie D.; Natsuaki, Misaki N.; Shaw, Daniel S.; Reiss, David; Ge, Xiaojia

    2011-01-01

    This study examined the developmental cascade of both genetic and environmental influences on toddlers’ behavior problems through the longitudinal and multi-generational assessment of psychosocial risk. We used data from the Early Growth and Development Study, a prospective adoption study, to test the intergenerational transmission of risk through the assessment of adoptive mother, adoptive father, and biological parent depressive symptoms on toddler behavior problems. Given that depression is often chronic, we control for across-time continuity and find that in addition to associations between adoptive mother depressive symptoms and toddler externalizing problems, adoptive father depressive symptoms when the child is 9-months of age were associated with toddler problems and associated with maternal depressive symptoms. Findings also indicated that a genetic effect may indirectly influence toddler problems through prenatal pregnancy risk. These findings help to describe how multiple generations are linked through genetic (biological parent), timing (developmental age of the child), and contextual (marital partner) pathways. PMID:20883583

  11. Marital Quality Moderates Genetic and Environmental Influences on the Internalizing Spectrum

    PubMed Central

    South, Susan C.; Krueger, Robert F.

    2008-01-01

    Poor marital quality is a reliable correlate of internalizing problems, but the etiology of this association has yet to be examined. Marital distress may exert its influence by acting as a stressor that enables the expression of latent genetic risk for internalizing psychopathology. We examined this question using 379 twin pairs concordant for marriage who were assessed for marital quality, symptoms of major depression (MD), generalized anxiety disorder (GAD), panic attacks (PA), and neuroticism (N). First, we conducted a phenotypic factor analysis to confirm that one factor best accounted for the variance shared between MD, GAD, PA, and N. After accounting for genetic influences on the general internalizing factor, there were residual genetic influences on neuroticism but no specific genetic influences on any other individual internalizing syndrome. We then investigated the overlap between genetic and environmental influences on both marital quality and the internalizing spectrum, and found genetic influences common to both phenotypes. Finally, biometrical moderation models revealed that genetic effects on the internalizing factor decreased from low (h2=.29) to high (h2=.05) levels of marital quality, suggesting that those with a genetic predisposition to internalizing syndromes may be more likely to express this predisposition in the context of a dissatisfying marriage. PMID:19025229

  12. Pseudocholinesterase deficiency: a comprehensive review of genetic, acquired, and drug influences.

    PubMed

    Soliday, Flanna K; Conley, Yvette P; Henker, Richard

    2010-08-01

    Pseudocholinesterase deficiency is an inherited or acquired condition in which the metabolism of succinylcholine, mivacurium, or ester local anesthetics is potentially impaired. In this review, genetic inheritance, variants, and testing are examined. Additionally, acquired conditions and drugs that influence enzyme activity, as well as possible treatments of the condition, are reviewed. The review of the literature was conducted by searching PubMed and Ovid Medline databases, with no limitation on date of publication. The search was limited to English-language journals only. Additional articles of relevance were obtained from reference lists of previously searched articles and via Internet searches. Numerous keywords were used in the search, and a second search was undertaken to find specific citations about acquired conditions and drugs of relevance. Nearly 250 articles were obtained and examined for importance. Fifty articles appear in the review, including case reports, research studies, and review articles. PMID:20879632

  13. Influence of genetic abnormalities on semen quality and male fertility: A four-year prospective study

    PubMed Central

    Elfateh, Fadlalla; Wang, Ruixue; Zhang, Zhihong; Jiang, Yuting; Chen, Shuang; Liu, Ruizhi

    2014-01-01

    Background: Wide range of disorders ranging from genetic disorders to coital difficulties can influence male fertility. In this regard, genetic factors are highlighted as the most frequent, contributed to 10-15%, of male infertility causes. Objective: To investigate the influence of genetic abnormalities on semen quality and reproductive hormone levels of infertile men from Northeast China. Materials and Methods: 2034 infertile men including 691 patients with abnormal sperm parameters were investigated retrospectively. Semen analysis was performed according to the World Health Organization guidelines. Y chromosome micro deletions were detected by polymerase chain reaction assays. Chromosome analysis was performed using G-banding. Results: The incidence of abnormal chromosomal karyotype in the patients with abnormal sperm parameters was 12.01% (83/691). The most frequent cause was Klinefelter's syndrome 37.35% (31/83). As the same as chromosomal abnormalities group, the volumes of testes (p=0.000 and 0.000, respectively) and the levels of testosterone (T) (p=0.000), and testosterone/ luteinizing hormone (T/LH) (p=0.000) of patients with Y chromosome micro deletions were significantly lower than those of fertile group. In addition, the levels of follicle-stimulating hormone (FSH) (p=0.000), and luteinizing hormone (LH) (p=0.000) were significantly higher in patients with Y chromosome micro deletions than those in the fertile group. Translocation abnormalities displayed slight effect on sperm motility. Conclusion: Y chromosome micro deletions and sex chromosome disorders particularly Klinefelter’s (47, XXY), have severe adverse influence on normal hormone levels, testicular volume and sperm count, whereas translocation abnormalities may inversely correlate with sperm motility. PMID:24799866

  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. 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

  16. Genetic and Environmental Influences on Media Use and Communication Behaviors

    ERIC Educational Resources Information Center

    Kirzinger, Ashley E.; Weber, Christopher; Johnson, Martin

    2012-01-01

    A great deal of scholarly work has explored the motivations behind media consumption and other various communication traits. However, little research has investigated the sources of these motivations and virtually no research considers their potential genetic underpinnings. Drawing on the field of behavior genetics, we use a classical twin design…

  17. 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

  18. RNAi phenotypes are influenced by the genetic background of the injected strain

    PubMed Central

    2013-01-01

    Background RNA interference (RNAi) is a powerful tool to study gene function in organisms that are not amenable to classical forward genetics. Hence, together with the ease of comprehensively identifying genes by new generation sequencing, RNAi is expanding the scope of animal species and questions that can be addressed in terms of gene function. In the case of genetic mutants, the genetic background of the strains used is known to influence the phenotype while this has not been described for RNAi experiments. Results Here we show in the red flour beetle Tribolium castaneum that RNAi against Tc-importin α1 leads to different phenotypes depending on the injected strain. We rule out off target effects and show that sequence divergence does not account for this difference. By quantitatively comparing phenotypes elicited by RNAi knockdown of four different genes we show that there is no general difference in RNAi sensitivity between these strains. Finally, we show that in case of Tc-importin α1 the difference depends on the maternal genotype. Conclusions These results show that in RNAi experiments strain specific differences have to be considered and that a proper documentation of the injected strain is required. This is especially important for the increasing number of emerging model organisms that are being functionally investigated using RNAi. In addition, our work shows that RNAi is suitable to systematically identify the differences in the gene regulatory networks present in populations of the same species, which will allow novel insights into the evolution of animal diversity. PMID:23324472

  19. Genetic and Environmental Influences on Eating Behavior - A Study of Twin Pairs Reared Apart or Reared Together

    PubMed Central

    Elder, Sonya J.; Neale, Michael C.; Fuss, Paul J.; Lichtenstein, Alice H.; Greenberg, Andrew S.; McCrory, Megan A.; Bouchard, Thomas J.; Saltzman, Edward; Roberts, Susan B.

    2014-01-01

    This study examined the relative influence of genetic versus environmental factors on specific aspects of eating behavior. Adult monozygotic twins (22 pairs and 3 singleton reared apart, 38 pairs and 9 singleton reared together, age 18–76 years, BMI 17–43 kg/m2) completed the Three Factor Eating Questionnaire. Genetic and environmental variance components were determined for the three eating behavior constructs and their subscales using model-fitting univariate and multivariate analyses. Unique environmental factors had a substantial influence on all eating behavior variables (explaining 45–71% of variance), and most strongly influenced external locus for hunger and strategic dieting behavior of restraint (explaining 71% and 69% of variance, respectively). Genetic factors had a statistically significant influence on only 4 variables: restraint, emotional susceptibility to disinhibition, situational susceptibility to disinhibition, and internal locus for hunger (heritabilities were 52%, 55%, 38% and 50%, respectively). Common environmental factors did not statistically significantly influence any variable assessed in this study. In addition, multivariate analyses showed that disinhibition and hunger share a common influence, while restraint appears to be a distinct construct. These findings suggest that the majority of variation in eating behavior variables is associated with unique environmental factors, and highlights the importance of the environment in facilitating specific eating behaviors that may promote excess weight gain. PMID:25067963

  20. Genetic and Environmental Influences on Eating Behavior - A Study of Twin Pairs Reared Apart or Reared Together.

    PubMed

    Elder, Sonya J; Neale, Michael C; Fuss, Paul J; Lichtenstein, Alice H; Greenberg, Andrew S; McCrory, Megan A; Bouchard, Thomas J; Saltzman, Edward; Roberts, Susan B

    2012-04-01

    This study examined the relative influence of genetic versus environmental factors on specific aspects of eating behavior. Adult monozygotic twins (22 pairs and 3 singleton reared apart, 38 pairs and 9 singleton reared together, age 18-76 years, BMI 17-43 kg/m(2)) completed the Three Factor Eating Questionnaire. Genetic and environmental variance components were determined for the three eating behavior constructs and their subscales using model-fitting univariate and multivariate analyses. Unique environmental factors had a substantial influence on all eating behavior variables (explaining 45-71% of variance), and most strongly influenced external locus for hunger and strategic dieting behavior of restraint (explaining 71% and 69% of variance, respectively). Genetic factors had a statistically significant influence on only 4 variables: restraint, emotional susceptibility to disinhibition, situational susceptibility to disinhibition, and internal locus for hunger (heritabilities were 52%, 55%, 38% and 50%, respectively). Common environmental factors did not statistically significantly influence any variable assessed in this study. In addition, multivariate analyses showed that disinhibition and hunger share a common influence, while restraint appears to be a distinct construct. These findings suggest that the majority of variation in eating behavior variables is associated with unique environmental factors, and highlights the importance of the environment in facilitating specific eating behaviors that may promote excess weight gain. PMID:25067963

  1. Behavior Problems among Children from Different Family Structures: The Influence of Genetic Self-Selection.

    ERIC Educational Resources Information Center

    Cleveland, H. Harrington; Wiebe, Richard P.; van den Oord, Edwin J. C. G.; Rowe, David C.

    2000-01-01

    Examined influences on children's behavior problems in households defined by marital status and sibling relatedness. Found that genetic influences accounted for 81 to 94 percent of mean-level difference in behavior problems between two-parent/full sibling, and the mother-only/half sibling groups. Shared environmental influences accounted for 67 to…

  2. [Genetic-statistical analysis of environmental and genetic influences on the outcome of the juvenile and breeding performance tests for behaviour traits in Hovawart dogs].

    PubMed

    Boenigk, Katharina; Hamann, Henning; Distl, Ottmar

    2006-01-01

    The objective of the present study was to evaluate the importance of genetic and environmental sources of variation for results of behaviour tests recorded at juvenile and breeding performance tests in the Hovawart dog. For these analyses behaviour test results of 1882 (juvenile evaluation), respectively 929 dogs (breeding performance test) born in 1995 to 2000 had been used. Variance component estimation was performed for the traits appearance, play instinct, hunting affinity, group of people, shoot, acoustical and optical influences and temperament using multivariate linear animal models and Residual Maximum Likelihood (REML). The models included test-year-season, sex, litter size, age and inbreeding coefficient of the animal as fixed effects. Additive genetic effects of the animal, permanent environmental effect of the litter and the effect of the kennel were considered as random factors. The sex of the dog was significant for appearance, play instinct, hunting affinity, acoustical and optical influences of juvenile evaluation and for the traits temperament, play instinct, hunting affinity, acoustical and one of the optical influences of breeding performance test. The age of the dog at test significantly influenced the traits play instinct, hunting affinity and acoustical influences of juvenile evaluation and optical influences and hunting affinity of breeding performance test. All traits with exception of hunting affinity and group of people were significantly affected by the test-year-season. The inbreeding coefficient was significant for appearance of juvenile evaluation and play affinity of breeding performance test. The effect litter size did not influence any of the traits significantly. The estimated heritabilities for the behaviour traits of juvenile and breeding performance test ranged from h2 = 0.01 to h2 = 0.13, respectively h2 = 0.01 to h2 = 0.14, with standard errors of up to 0.03. The additive genetic correlations between most of the traits were

  3. 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

  4. Examination of genetic variants influencing lipid traits in pediatric populations

    PubMed Central

    Wang, Kai; Zhang, Haitao; Mentch, Frank D.; Bradfield, Jonathan P.; Glessner, Joseph T.; Qiu, Haijun; Guo, Yiran; Hou, Cuiping; Frackelton, Edward C.; Thomas, Kelly; Bender, Amber; Albano, Anthony; Otieno, George; Garris, Maria; Seidler, Kallyn; Moy, Alexander; Kim, Cecilia E.; Keating, Brendan; Chiavacci, Rosetta M.; Grundmeier, Robert; Sleiman, Patrick A.; Grant, Struan F.A.; Hakonarson, Hakon

    2012-01-01

    Previous large-scale genome-wide association studies in adult populations have implicated ∽100 loci in determining high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, or triglyceride levels. However, whether these loci also contribute to variations of lipid traits in pediatric populations remain unknown. Here we assayed a population of Philadelphia children by high-density single nucleotide polymorphism arrays, and performed association analysis on lipid traits ascertained from lipid measurements stored in electronic medical records. We examined previously reported lipid trait associations, and found that most of them show identical direction of association in our pediatric cohorts, including genome-wide significant association on cholesteryl ester transfer protein with HDL-C levels (rs3764261, P = 2.1 × 10−8) and other significant associations on oxysterol-binding protein-like protein 7, low-density lipoprotein receptor-related protein 4 and low-density lipoprotein receptor-related protein 1. Additionally, we identified suggestive association on low-density lipoprotein receptor-related protein 1B with HDL-C levels (rs17736712, P = 2.1 × 10−7), but this signal is not supported by previous meta-analysis on adult cohorts. Finally, we examined rare copy number variants and identified deletions encompassing tetratricopeptide repeat domain 39B in two children with extreme lipid measures. Our results highlight the commonalities and differences of genetic components in determining lipid traits in pediatric versus adult populations. Furthermore, our study demonstrates the unique utility of automated information retrieval from electronic medical records in facilitating the identification of genotype-phenotype associations.

  5. Additive effects of word frequency and stimulus quality: the influence of trial history and data transformations.

    PubMed

    Balota, David A; Aschenbrenner, Andrew J; Yap, Melvin J

    2013-09-01

    A counterintuitive and theoretically important pattern of results in the visual word recognition literature is that both word frequency and stimulus quality produce large but additive effects in lexical decision performance. The additive nature of these effects has recently been called into question by Masson and Kliegl (in press), who used linear mixed effects modeling to provide evidence that the additive effects were actually being driven by previous trial history. Because Masson and Kliegl also included semantic priming as a factor in their study and recent evidence has shown that semantic priming can moderate the additivity of word frequency and stimulus quality (Scaltritti, Balota, & Peressotti, 2012), we reanalyzed data from 3 published studies to determine if previous trial history moderated the additive pattern when semantic priming was not also manipulated. The results indicated that previous trial history did not influence the joint influence of word frequency and stimulus quality. More important, and independent of Masson and Kliegl's conclusions, we also show how a common transformation used in linear mixed effects analyses to normalize the residuals can systematically alter the way in which two variables combine to influence performance. Specifically, using transformed, rather than raw reaction times, consistently produces more underadditive patterns. PMID:23565779

  6. Choice of Reading Comprehension Test Influences the Outcomes of Genetic Analyses.

    PubMed

    Betjemann, Rebecca S; Keenan, Janice M; Olson, Richard K; Defries, John C

    2011-01-01

    Does the choice of test for assessing reading comprehension influence the outcome of genetic analyses? A twin design compared two types of reading comprehension tests classified as primarily associated with word decoding (RC-D) or listening comprehension (RC-LC). For both types of tests, the overall genetic influence is high and nearly identical. However, the tests differed significantly in how they covary with the genes associated with decoding and listening comprehension. Although Cholesky decomposition showed that both types of comprehension tests shared significant genetic influence with both decoding and listening comprehension, RC-D tests shared most genetic variance with decoding, and RC-LC tests shared most with listening comprehension. Thus, different tests used to measure the same construct may manifest very different patterns of genetic covariation. These results suggest that the apparent discrepancies among the findings of previous twin studies of reading comprehension could be due at least in part to test differences. PMID:21804757

  7. Family Environmental and Genetic Influences on Children's Future Chemical Dependency.

    ERIC Educational Resources Information Center

    Kumpfer, Karol L.; DeMarsh, Joseph

    1985-01-01

    Discusses the following in relation to their predictability to future drug abuse in youth: (1) susceptibility of children of chemically dependent parents; (2) genetic transmutation; (3) family structure and management; (4) socialization; and (5) cognitive family characteristics. (Author/LHW)

  8. [Influence of maternal genetic effect on genetic parameter estimates of production traits of cashmere goat].

    PubMed

    Bai, Jun-Yan; Li, Jin-Quan; Jia, Xiao-Ping; Zhang, Qin; Dao, Er-Ji

    2006-09-01

    The derivative-free restricted maximum likelihood (DFREML) method was used to compare the differences of genetic parameter estimates of Inner Mongolian Cashmere Goats under two models, which differ in whether maternal genetic effect is taken into account. The differences between the two models were, tested by likelihood ratio test. The results show that maternal genetic effect highly affects live body weight and cashmere thickness while has no significant effect on raw cashmere weight, staple length, fibre diameter and fibre length. PMID:16963416

  9. Genetic and environmental influences on residential location in the U.S

    PubMed Central

    Duncan, Glen E.; Dansie, Elizabeth J.; Strachan, Eric; Munsell, Melissa; Huang, Ruizhu; Moudon, Anne Vernez; Goldberg, Jack; Buchwald, Dedra

    2012-01-01

    We used a classical twin design and measures of neighborhood walkability and social deprivation, using each twin’s street address, to examine genetic and environmental influences on the residential location of 1,389 same-sex pairs from a U.S. community-based twin registry. Within-pair correlations and structural equation models estimated these influences on walkability among younger (ages 18–24.9) and older (ages 25+) twins. Adjusting for social deprivation, walkability of residential location was primarily influenced by common environment with lesser contributions of unique environment and genetic factors among younger twins, while unique environment most strongly influenced walkability, with small genetic and common environment effects, among older twins. Thus, minimal variance in walkability was explained by shared genetic effects in younger and older twins, and confirms the importance of environmental factors in walkability of residential locations. PMID:22377617

  10. Shared Genetic Influences on Negative Emotionality and Major Depression/Conduct Disorder Comorbidity

    ERIC Educational Resources Information Center

    Tackett, Jennifer L.; Waldman, Irwin D.; Van Hulle, Carol A.; Lahey, Benjamin B.

    2011-01-01

    Objective: To investigate whether genetic contributions to major depressive disorder and conduct disorder comorbidity are shared with genetic influences on negative emotionality. Method: Primary caregivers of 2,022 same- and opposite-sex twin pairs 6 to 18 years of age comprised a population-based sample. Participants were randomly selected across…

  11. Twin Studies in Autism: What Might They Say about Genetic and Environmental Influences

    ERIC Educational Resources Information Center

    Anderson, George M.

    2012-01-01

    Genetic and epigenetic differences exist within monozygote twin-pairs and might be especially important in the expression of autism. Assuming phenotypic differences between monozygotic twins are due to environmental influences may lead to mistaken conclusions regarding the relative genetic and environmental contribution to autism risk.

  12. ENVIRONMENTAL STRESS AND GENETICS INFLUENCE NIGHTTIME LEAF CONDUCTANCE IN THE C4 GRASS DISTICHLIS SPICATA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Growing awareness of nighttime leaf conductance (gnight) in many species, as well as genetic variation in gnight within several species, has raised questions about how genetic variation and environmental stress interact to influence the magnitude of gnight. The objective of this study was to invest...

  13. Genetic variations of FACL4 have no obvious influence on cognitive ability in young Chinese children.

    PubMed

    Zhang, Kejin; Zheng, Zijian; An, Caiyan; Gao, Xiaocai; Zhang, Fuchang

    2010-06-30

    The influence of genetic variants of FACL4 on individual cognitive ability was examined in a random sample of 213 boys and 224 girls. Both conventional genetic methods and analysis of variance were applied in this study. We found no significant relationship between FACL4 and cognitive function. PMID:20452052

  14. Genetic Influences on Activity Level in Early Childhood: Do Situations Matter?

    ERIC Educational Resources Information Center

    Saudino, Kimberly J.; Zapfe, Jeffrey A.

    2008-01-01

    Although genetic influences on individual differences in activity level (AL) are well documented, few studies have considered the etiology of AL from a contextual perspective. In the present study, cross-situational and context-specific genetic effects on individual differences in AL at age 2 were examined. The AL of 312 twin pairs (144…

  15. Children's History of Speech-Language Difficulties: Genetic Influences and Associations with Reading-Related Measures

    ERIC Educational Resources Information Center

    DeThorne, Laura Segebart; Hart, Sara A.; Petrill, Stephen A.; Deater-Deckard, Kirby; Thompson, Lee Anne; Schatschneider, Chris; Davison, Megan Dunn

    2006-01-01

    Purpose: This study examined (a) the extent of genetic and environmental influences on children's articulation and language difficulties and (b) the phenotypic associations between such difficulties and direct assessments of reading-related skills during early school-age years. Method: Behavioral genetic analyses focused on parent-report data…

  16. The Michigan State University Twin Registry (MSUTR): genetic, environmental and neurobiological influences on behavior across development.

    PubMed

    Klump, Kelly L; Burt, S Alexandra

    2006-12-01

    The primary aim of the Michigan State University Twin Registry (MSUTR) is to examine developmental differences in genetic, environmental, and neurobiological influences on internalizing and externalizing symptoms, with disordered eating and antisocial behavior representing particular areas of interest. Twin participants span several developmental stages (i.e., childhood, adolescence, and young adulthood). Assessments include comprehensive, multi-informant measures of psychiatric and behavioral phenotypes, buccal swab and salivary DNA samples, assays of adolescent and adult steroid hormone levels (e.g., estradiol, progesterone, testosterone, cortisol), and videotaped parent-child interactions of child and adolescent twin families. To date, we have collected data on over 1000 twins, with additional data collections underway. This article provides an overview of the newly developed MSUTR and describes current and future research directions. PMID:17254439

  17. The influence of additives on beer stability investigated by EPR spectroscopy

    NASA Astrophysics Data System (ADS)

    Brezová, Vlasta; Polovka, Martin; Staško, Andrej

    2002-04-01

    In thermally-accelerated aging followed by EPR spectroscopy of beer samples of various stabilities, free radical 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL) was shown to be an effective indicator of the breakdown of a sample's stability, comparable to the commonly used spin trapping agent α-phenyl- N- tert-butylnitrone (PBN). Both indicators were then employed to investigate the influence of additives on beer stability. The addition of L-ascorbic acid (ASC) to the beer samples accelerated the radical processes and a lower stability was found. DL-α-tocopherol (α-TOC) did not influence beer stability significantly (probably due to its limited solubility). Na 2SO 3, described as a very effective stabilizer in experiments with the PBN spin trap, was found not to be effective using the TEMPOL indicator. This is probably due to inhibition in the formation of spin adducts or their degradation by Na 2SO 3.

  18. The influence of additives on beer stability investigated by EPR spectroscopy.

    PubMed

    Brezová, Vlasta; Polovka, Martin; Stasko, Andrej

    2002-04-01

    In thermally-accelerated aging followed by EPR spectroscopy of beer samples of various stabilities, free radical 4-hydroxy-2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPOL) was shown to be an effective indicator of the breakdown of a sample's stability, comparable to the commonly used spin trapping agent alpha-phenyl-N-tert-butylnitrone (PBN). Both indicators were then employed to investigate the influence of additives on beer stability. The addition of L-ascorbic acid (ASC) to the beer samples accelerated the radical processes and a lower stability was found. DL-alpha-tocopherol (alpha-TOC) did not influence beer stability significantly (probably due to its limited solubility). Na2SO3, described as a very effective stabilizer in experiments with the PBN spin trap, was found not to be effective using the TEMPOL indicator. This is probably due to inhibition in the formation of spin adducts or their degradation by Na2SO3. PMID:11993475

  19. Community acquired pneumonia: genetic variants influencing systemic inflammation.

    PubMed

    Ferrer Agüero, J M; Millán, S; Rodríguez de Castro, F; Martín-Loeches, I; Solé Violán, J

    2014-01-01

    The inflammatory response depends on several factors, including pathogenicity and duration of the stimulus, and also on the balance between inflammatory and antiinflammatory response. Several studies have presented evidence of the importance of genetic factors in severe infections. The innate immune response prevents the invasion and spread of pathogens during the first hours after infection. Each of the different processes involved in innate immunity may be affected by genetic polymorphisms, which can result in susceptibility or resistance to infection. The results obtained in the different studies do not irrefutably prove the role or function of a gene in the pathogenesis of respiratory infections. However, they can generate new hypotheses, suggest new candidate genes based on their role in the inflammatory response, and constitute a first step in understanding the underlying genetic factors. PMID:24183496

  20. Influence of modifying additives on the electronic state of supported palladium

    NASA Astrophysics Data System (ADS)

    Pestryakov, A. N.; Lunin, V. V.; Fuentes, S.; Bogdanchikova, N.; Barrera, A.

    2003-01-01

    The influence of modifying additives of Ce, Zr, La and Cs oxides on the electronic state of palladium supported on γ-Al 2O 3 has been studied by IR-spectroscopy of adsorbed CO, diffuse reflectance UV-visible spectroscopy, X-ray diffraction (XRD) and H 2 chemisorption. The modified supports have been prepared using impregnation, coprecipitation and sol-gel methods. It is established that Ce and Zr oxide additives increase the effective charge of palladium ions whereas La and Cs oxides lower it. The effect of metal-support interaction is stronger in samples prepared by sol-gel than by coprecipitation

  1. Relative Influence of Genetics and Shared Environment on Child Mental Health Symptoms Depends on Comorbidity

    PubMed Central

    Van Hulle, Carol A.; Lemery-Chalfant, Kathryn; Maier, Rose; Davidson, Richard J.; Goldsmith, H. Hill

    2014-01-01

    Background Comorbidity among childhood mental health symptoms is common in clinical and community samples and should be accounted for when investigating etiology. We therefore aimed to uncover latent classes of mental health symptoms in middle childhood in a community sample, and to determine the latent genetic and environmental influences on those classes. Methods The sample comprised representative cohorts of twins. A questionnaire-based assessment of mental health symptoms was used in latent class analyses. Data on 3223 twins (1578 boys and 1645 girls) with a mean age of 7.5 years were analyzed. The sample was predominantly non-Hispanic Caucasian (92.1%). Results Latent class models delineated groups of children according to symptom profiles–not necessarily clinical groups but groups representing the general population, most with scores in the normative range. The best-fitting models suggested 9 classes for both girls and boys. Eight of the classes were very similar across sexes; these classes ranged from a “Low Symptom” class to a “Moderately Internalizing & Severely Externalizing” class. In addition, a “Moderately Anxious” class was identified for girls but not boys, and a “Severely Impulsive & Inattentive” class was identified for boys but not girls. Sex-combined analyses implicated moderate genetic influences for all classes. Shared environmental influences were moderate for the “Low Symptom” and “Moderately Internalizing & Severely Externalizing” classes, and small to zero for other classes. Conclusions We conclude that symptom classes are largely similar across sexes in middle childhood. Heritability was moderate for all classes, but shared environment played a greater role for classes in which no one type of symptom predominated. PMID:25077799

  2. Shared Genetic Factors Influence Amygdala Volumes and Risk for Alcoholism

    PubMed Central

    Dager, Alecia D; McKay, D Reese; Kent, Jack W; Curran, Joanne E; Knowles, Emma; Sprooten, Emma; Göring, Harald HH; Dyer, Thomas D; Pearlson, Godfrey D; Olvera, Rene L; Fox, Peter T; Lovallo, William R; Duggirala, Ravi; Almasy, Laura; Blangero, John; Glahn, David C

    2015-01-01

    Alcohol abuse and dependence (alcohol use disorders, AUDs) are associated with brain shrinkage. Subcortical structures including the amygdala, hippocampus, ventral striatum, dorsal striatum, and thalamus subserve reward functioning and may be particularly vulnerable to alcohol-related damage. These structures may also show pre-existing deficits impacting the development and maintenance of AUD. It remains unclear whether there are common genetic features underlying both subcortical volumes and AUD. In this study, structural brain images were acquired from 872 Mexican-American individuals from extended pedigrees. Subcortical volumes were obtained using FreeSurfer, and quantitative genetic analyses were performed in SOLAR. We hypothesized the following: (1) reduced subcortical volumes in individuals with lifetime AUD relative to unrelated controls; (2) reduced subcortical volumes in individuals with current relative to past AUD; (3) in non-AUD individuals, reduced subcortical volumes in those with a family history of AUD compared to those without; and (4) evidence for common genetic underpinnings (pleiotropy) between AUD risk and subcortical volumes. Results showed that individuals with lifetime AUD showed larger ventricular and smaller amygdala volumes compared to non-AUD individuals. For the amygdala, there were no differences in volume between current vs past AUD, and non-AUD individuals with a family history of AUD demonstrated reductions compared to those with no such family history. Finally, amygdala volume was genetically correlated with the risk for AUD. Together, these results suggest that reduced amygdala volume reflects a pre-existing difference rather than alcohol-induced neurotoxic damage. Our genetic correlation analysis provides evidence for a common genetic factor underlying both reduced amygdala volumes and AUD risk. PMID:25079289

  3. Genetic and environmental influences on self-concept in female preadolescent twins: comparison of Minnesota and Seoul data.

    PubMed

    Hur, Yoon-Mi

    2005-08-01

    It has been argued that culture significantly influences the developmental basis of self-concept. The goal of the present study is to compare the relative importance of genetic and environmental factors to explain individual differences in various dimensions of self-concept in female preadolescents of Minnesota in the United States and Seoul in South Korea. Two hundred and eighteen monozygotic (MZ) and 137 dizygotic (DZ) twin pairs from the Minnesota Twin Family Study (MTFS) and 74 MZ and 42 DZ twin pairs from the Seoul Twin Family Study (STFS) completed the 6 cluster scales of the Piers-Harris Children's Self-Concept Scale (P-H). The 6 cluster scales of the P-H include Popularity, Physical Appearance and Attributes, Behavior, Intellectual Competence and School Status, Anxiety, and Happiness and Satisfaction. Univariate model-fitting analyses were performed. In both samples, a model incorporating shared and nonshared environmental influences fitted the data best for Popularity, Anxiety, and Intellectual Competence and School Status, whereas a model including additive genetic and nonshared environmental factors provided the best fit for Physical Appearance and Attributes, and Behavior. The univariate model did not yield an adequate fit for Happiness and Satisfaction. For Physical Appearance and Attributes, and Intellectual Competence and School Status, estimates of additive genetic and environmental factors were significantly different between the MTFS and the STFS samples. For Popularity, Anxiety, and Behavior, however, the genetic and environmental estimates were comparable between the two samples. PMID:16176711

  4. Genetic Influences on Peer and Family Relationships Across Adolescent Development: Introduction to the Special Issue.

    PubMed

    Mullineaux, Paula Y; DiLalla, Lisabeth Fisher

    2015-07-01

    Nearly all aspects of human development are influenced by genetic and environmental factors, which conjointly shape development through several gene-environment interplay mechanisms. More recently, researchers have begun to examine the influence of genetic factors on peer and family relationships across the pre-adolescent and adolescent time periods. This article introduces the special issue by providing a critical overview of behavior genetic methodology and existing research demonstrating gene-environment processes operating on the link between peer and family relationships and adolescent adjustment. The overview is followed by a summary of new research studies, which use genetically informed samples to examine how peer and family environment work together with genetic factors to influence behavioral outcomes across adolescence. The studies in this special issue provide further evidence of gene-environment interplay through innovative behavior genetic methodological approaches across international samples. Results from the quantitative models indicate environmental moderation of genetic risk for coercive adolescent-parent relationships and deviant peer affiliation. The molecular genetics studies provide support for a gene-environment interaction differential susceptibility model for dopamine regulation genes across positive and negative peer and family environments. Overall, the findings from the studies in this special issue demonstrate the importance of considering how genes and environments work in concert to shape developmental outcomes during adolescence. PMID:26006709

  5. Influence of electrolyte co-additives on the performance of dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Stergiopoulos, Thomas; Rozi, Evangelia; Karagianni, Chaido-Stefania; Falaras, Polycarpos

    2011-12-01

    The presence of specific chemical additives in the redox electrolyte results in an efficient increase of the photovoltaic performance of dye-sensitized solar cells (DSCs). The most effective additives are 4- tert-butylpyridine (TBP), N-methylbenzimidazole (NMBI) and guanidinium thiocyanate (GuNCS) that are adsorbed onto the photoelectrode/electrolyte interface, thus shifting the semiconductor's conduction band edge and preventing recombination with triiodides. In a comparative work, we investigated in detail the action of TBP and NMBI additives in ionic liquid-based redox electrolytes with varying iodine concentrations, in order to extract the optimum additive/I2 ratio for each system. Different optimum additive/I2 ratios were determined for TBP and NMBI, despite the fact that both generally work in a similar way. Further addition of GuNCS in the optimized electrolytic media causes significant synergistic effects, the action of GuNCS being strongly influenced by the nature of the corresponding co-additive. Under the best operation conditions, power conversion efficiencies as high as 8% were obtained.

  6. Genetic background influences loss of heterozygosity patterns in radiation-induced mouse thymic lymphoma

    PubMed Central

    Hang, Michael; Huang, Yurong; Snijders, Antoine M.; Mao, Jian-Hua

    2015-01-01

    Previous studies have revealed that p53 heterozygous (p53+/−) mice are extremely susceptible to radiation-induced tumorigenesis. To investigate whether genetic background influences radiation induced tumor susceptibility, we crossed p53+/− 129/Sv mice with genetically diverse strains to generate p53+/− F1 hybrids. The results showed that genetic background had a profound impact on tumor latency after exposure to gamma radiation, while the tumor spectrum did not change. We further characterized the thymic lymphomas that arose in the p53+/− mice by genome-wide loss of heterozygosity (LOH) analyses and found that genetic background strongly influenced the frequency of LOH and the loss of which parental allele on different chromosomes. Further research is needed to identify which genetic variations control the LOH patterns in radiation-induced thymic lymphomas and to evaluate its relevance to human cancers. PMID:25932465

  7. Reading Skills in Early Readers: Genetic and Shared Environmental Influences

    ERIC Educational Resources Information Center

    Petrill, Stephen A.; Deater-Deckard, Kirby; Thompson, Lee Anne; DeThorne, Laura S.; Schatschneider, Christopher

    2006-01-01

    The present study combined parallel data from the Northeast-Northwest Collaborative Adoption Projects (N2CAP) and the Western Reserve Reading Project (WRRP) to examine sibling similarity and quantitative genetic model estimates for measures of reading skills in 272 school-age sibling pairs from three family types (monozygotic twins, dizygotic…

  8. Obesity among Black Adolescent Girls: Genetic, Psychosocial, and Cultural Influences

    ERIC Educational Resources Information Center

    Alleyne, Sylvan I.; LaPoint, Velma

    2004-01-01

    This article focuses on the causes, consequences, and prevention of obesity among a subgroup of the American population, Black adolescent girls. Using an ecological perspective on obesity among Black adolescent girls, including feminist-womanist perspectives and historical and medical sociological perspectives, the authors discuss genetic,…

  9. Evidence for independent genetic influences on obesity in middle age.

    PubMed

    Fabsitz, R R; Carmelli, D; Hewitt, J K

    1992-09-01

    The National Heart, Lung, and Blood Institute (NHLBI) Twin Study provided longitudinal data on a cohort of 514 pairs of adult male twin pairs who were examined at approximate ages of 48, 57, and 63 years. Because the sample was selected from military veterans, height and weight data were also available from their induction physical examinations when they were approximately 20 years of age. From the total NHLBI Twin Study cohort, 124 monozygotic and 119 dizygotic male twin pairs had complete data available for both members of the pair at induction and three examinations spanning 43 years of adult life. Using these data, the contributions of genetics and shared and non-shared environmental factors to BMI over the 43 year period were estimated by model fitting procedures. Model fitting included both a factor decomposition of these effects as well as a developmental path model. Results from the decomposition procedure indicate significant genetic effects at each examination cycle. Fitting a developmental path model, two independent genetic contributions to the variability of BMI were found: one at, or prior to, the induction examination about age 20, and a second between ages 20 and 48. Significant non-shared environmental contributions at each examination were also indicated, but shared environmental effects were not significant. We conclude that cumulative genetic effects explain most of the tracking in obesity over time; non-shared environmental effects, although significant at each age, are relatively short-lived and make only a minor contribution to tracking. PMID:1328090

  10. Influence of PEG-12 Dimethicone addition on stability and formation of emulsions containing liquid crystal.

    PubMed

    Andrade, F F; Santos, O D H; Oliveira, W P; Rocha-Filho, P A

    2007-06-01

    Oil/water emulsions, containing liquid crystals, were developed employing Andiroba oil, PEG-12 Dimethicone and Crodafos CES. It was evaluated the influence of silicone surfactants on the emulsions stability and on the formation of liquid crystalline phases and therefore, physicochemical characteristics, such as rheology and zeta potential, were evaluated. Emulsions were prepared by the emulsions phase inversion method. All the formulations presented lamellar liquid crystalline phases. The PEG-12 Dimethicone addition did not change microscopically the liquid crystalline phases. The emulsions containing silicone demonstrated lower viscosity than those without the additive. This is an important feature, as the silicone did not change the rheological profile; however, the addition of silicone still can be used as a viscosity controller. The formulations had their viscosity increased 15 and 150 days after their preparation. This characteristic shows that the emulsions have their organization increased along the storing time. In the analysis of zeta potential, we could verify that all formulations presented negative values between -39.7 and -70.0 mV. Within this range of values, the emulsion physical stability is high (Fig. 10). It was concluded that the addition of PEG-12 Dimethicone kept the liquid crystalline phase of the emulsion obtained with Crodafos CES, influencing in a positive way in the system stability. PMID:18489351

  11. Genetic influences in emotional dysfunction and alcoholism-related brain damage

    PubMed Central

    Oscar-Berman, Marlene; Bowirrat, Abdalla

    2005-01-01

    Alcoholism is a complex, multifactorial disorder involving problematic ethanol ingestion; it results from the interplay between genetic and environmental factors. Personality, likewise, is formed from a combination of inherited and acquired influences. Because selected dimensions of emotional temperament are associated with distinct neurochemical substrates contributing to specific personality phenotypes, certain aspects of abnormal emotional traits in alcoholics may be inherited. Emotions involve complex subjective experiences engaging multiple brain regions, most notably the cortex, limbic system, and cerebellum. Results of in vivo magnetic resonance imaging and post-mortem neuropathological studies of alcoholics indicate that the greatest cortical loss occurs in the frontal lobes, with concurrent thinning of the corpus callosum. Additional damage has been documented for the amygdala and hippocampus, as well as in the white matter of the cerebellum. All of the critical areas of alcoholism-related brain damage are important for normal emotional functioning. When changes occur in these brain regions, either as a consequence of chronic ethanol abuse or from a genetic anomaly affecting temperament and/or a vulnerability to alcoholism, corresponding changes in emotional functions are to be expected. In alcoholics, such changes have been observed in their perception and evaluation of emotional facial expressions, interpretation of emotional intonations in vocal utterances, and appreciation of the meaning of emotional materials. PMID:18568071

  12. Genetic Variants in REC8, RNF212, and PRDM9 Influence Male Recombination in Cattle

    PubMed Central

    Coppieters, Wouter; Druet, Tom; Charlier, Carole; Georges, Michel

    2012-01-01

    We use >250,000 cross-over events identified in >10,000 bovine sperm cells to perform an extensive characterization of meiotic recombination in male cattle. We map Quantitative Trait Loci (QTL) influencing genome-wide recombination rate, genome-wide hotspot usage, and locus-specific recombination rate. We fine-map three QTL and present strong evidence that genetic variants in REC8 and RNF212 influence genome-wide recombination rate, while genetic variants in PRDM9 influence genome-wide hotspot usage. PMID:22844258

  13. Substantial Genetic Influence on Mild Mental Impairment in Early Childhood

    ERIC Educational Resources Information Center

    Spinath, Frank M.; Harlaar, Nicole; Ronald, Angelica; Plomin, Robert

    2004-01-01

    We report the first major genetic study of mild mental impairment. From a representative sample of 3,886 twins (1,314 monozygotic, 1,296 dizygotic same-sex, and 1,276 dizygotic opposite-sex), the lowest 5% were selected on a composite measure of verbal and nonverbal abilities assessed by parents when the twins were 2, 3, and 4 years of age. Twin…

  14. Genetic and environmental influences on psychiatric comorbidity: A systematic review

    PubMed Central

    Cerdá, M.; Sagdeo, A.; Johnson, J.; Galea, S.

    2009-01-01

    Background The purpose of this review is to systematically appraise the peer-reviewed literature about the genetic and environmental determinants of psychiatric comorbidity, focusing on four of the most prevalent types of psychopathology: anxiety disorders, depression, conduct disorder and substance abuse. Methods We summarize existing empirical research on the relative contribution that genetic, nonshared and shared environmental factors make to the covariance between disorders, and evidence about specific genes and environmental characteristics that are associated with comorbidity. Results 94 articles met the inclusion criteria and were assessed. Genetic factors play a particularly strong role in comorbidity between major depression and generalized anxiety disorder or posttraumatic stress disorder, while the non-shared environments makes an important contribution to comorbidity in affective disorders. Genetic and non-shared environmental factors also make a moderate-to-strong contribution to the relationship between CD and SA. A range of candidate genes, such as 5HTTLPR, MAOA, and DRD1-DRD4, as well as others implicated in the central nervous system, has been implicated in psychiatric comorbidity. Pivotal social factors include childhood adversity/ life events, family and peer social connections, and socioeconomic and academic difficulties. Limitations Methodological concerns include the use of clinical case-control samples, the focus on a restricted set of individual-level environmental risk factors, and restricted follow-up times. Conclusions Given the significant mental health burden associated with comorbid disorders, population-based research on modifiable risk factors for psychiatric comorbidity is vital for the design of effective preventive and clinical interventions. PMID:20004978

  15. Genetic Ancestry Influences Asthma Susceptibility and Lung Function Among Latinos

    PubMed Central

    Pino-Yanes, Maria; Thakur, Neeta; Gignoux, Christopher R.; Galanter, Joshua M.; Roth, Lindsey A.; Eng, Celeste; Nishimura, Katherine K.; Oh, Sam S.; Vora, Hita; Huntsman, Scott; Nguyen, Elizabeth A.; Hu, Donglei; Drake, Katherine A.; Conti, David V.; Moreno-Estrada, Andres; Sandoval, Karla; Winkler, Cheryl A.; Borrell, Luisa N.; Lurmann, Fred; Islam, Talat S.; Davis, Adam; Farber, Harold J.; Meade, Kelley; Avila, Pedro C.; Serebrisky, Denise; Bibbins-Domingo, Kirsten; Lenoir, Michael A.; Ford, Jean G.; Brigino-Buenaventura, Emerita; Rodriguez-Cintron, William; Thyne, Shannon M.; Sen, Saunak; Rodriguez-Santana, Jose R.; Bustamante, Carlos D.; Williams, L. Keoki; Gilliland, Frank D.; Gauderman, W. James; Kumar, Rajesh; Torgerson, Dara G.; Burchard, Esteban G.

    2014-01-01

    Background Childhood asthma prevalence and morbidity varies among Latinos in the United States, with Puerto Ricans having the highest and Mexicans the lowest. Objective To determine whether genetic ancestry is associated with the odds of asthma among Latinos, and secondarily whether genetic ancestry is associated with lung function among Latino children. Methods We analyzed 5,493 Latinos with and without asthma from three independent studies. For each participant we estimated the proportion of African, European, and Native American ancestry using genome-wide data. We tested whether genetic ancestry was associated with the presence of asthma and lung function among subjects with and without asthma. Odds ratios (OR) and effect sizes were assessed for every 20% increase in each ancestry. Results Native American ancestry was associated with lower odds of asthma (OR=0.72, 95% confidence interval [CI]: 0.66–0.78, p=8.0×10−15), while African ancestry was associated with higher odds of asthma (OR=1.40, 95%CI: 1.14–1.72, p=0.001). These associations were robust to adjustment for covariates related to early life exposures, air pollution and socioeconomic status. Among children with asthma, African ancestry was associated with lower lung function, including both pre- and post-bronchodilator measures of forced expiratory volume in the first second (−77±19 ml, p=5.8×10−5 and −83±19 ml, p=1.1×10−5, respectively) and forced vital capacity (−100±21 ml, p=2.7×10−6 and −107±22 ml, p=1.0×10−6, respectively). Conclusion Differences in the proportions of genetic ancestry can partially explain disparities in asthma susceptibility and lung function among Latinos. PMID:25301036

  16. Genetic and Environmental Influences on Retinopathy of Prematurity

    PubMed Central

    Ortega-Molina, J. M.; Anaya-Alaminos, R.; Uberos-Fernández, J.; Solans-Pérez de Larraya, A.; Chaves-Samaniego, M. J.; Salgado-Miranda, A.; Piñar-Molina, R.; Jerez-Calero, A.; García-Serrano, J. L.

    2015-01-01

    Objective. The goals were to isolate and study the genetic susceptibility to retinopathy of prematurity (ROP), as well as the gene-environment interaction established in this disease. Methods. A retrospective study (2000–2014) was performed about the heritability of retinopathy of prematurity in 257 infants who were born at a gestational age of ≤32 weeks. The ROP was studied and treated by a single pediatric ophthalmologist. A binary logistic regression analysis was completed between the presence or absence of ROP and the predictor variables. Results. Data obtained from 38 monozygotic twins, 66 dizygotic twins, and 153 of simple birth were analyzed. The clinical features of the cohorts of monozygotic and dizygotic twins were not significantly different. Genetic factors represented 72.8% of the variability in the stage of ROP, environmental factors 23.08%, and random factors 4.12%. The environmental variables representing the highest risk of ROP were the number of days of tracheal intubation (p < 0.001), postnatal weight gain (p = 0.001), and development of sepsis (p = 0.0014). Conclusion. The heritability of ROP was found to be 0.73. The environmental factors regulate and modify the expression of the genetic code. PMID:26089603

  17. Potential consumers' attitudes toward psychiatric genetic research and testing and factors influencing their intentions to test.

    PubMed

    Laegsgaard, Mett Marri; Kristensen, Ann Suhl; Mors, Ole

    2009-02-01

    Psychiatric genetic research brings on the possibility of psychiatric genetic testing. The optimal and responsible utilization of genetic testing depends on knowledge of the potential consumers' attitudes and expectations regarding testing. The aim of this study was to assess potential consumers' attitudes and expectations toward psychiatric genetics and factors influencing their intentions to test. A questionnaire constructed to assess attitudes and intentions toward psychiatric genetic testing was mailed or given in person to individuals participating in different genetic studies aiming at identifying genes predisposing for mental illness. A total of 397 persons diagnosed with major depression, bipolar disorder, schizophrenia, or anxiety disorder participated in the survey. A large majority of the sample expressed an intention for themselves and their children to participate in psychiatric genetic testing. Support for prenatal testing was considerably less strong. A large minority expressed intention to test regardless of treatment possibilities. Intentions to test were positively associated with being a parent, trust in researchers, and expecting to feel better prepared for fighting the disorder when knowing of the presence of risk genes. Intentions were negatively associated with the fear of psychiatric genetic research bringing on too many difficult choices and fearing not to be able to cope with the results of a psychiatric genetic test. These results indicate that psychiatric genetic testing is not just perceived as a way to better treatment. Other expectations may motivate testing even though the clinical validity of the test is poor. PMID:19309275

  18. Influence of barriers to movement on within-watershed genetic variation of coastal cutthroat trout

    USGS Publications Warehouse

    Wofford, John E.B.; Gresswell, Robert E.; Banks, M.A.

    2005-01-01

    Because human land use activities often result in increased fragmentation of aquatic and terrestrial habitats, a better understanding of the effects of fragmentation on the genetic heterogeneity of animal populations may be useful for effective management. We used eight microsatellites to examine the genetic structure of coastal cutthroat trout (Oncorhynchus clarki clarki) in Camp Creek, an isolated headwater stream in western Oregon. Our objectives were to determine if coastal cutthroat trout were genetically structured within streams and to assess the effects of natural and anthropogenic barriers on coastal cutthroat trout genetic variation. Fish sampling occurred at 10 locations, and allele frequencies differed significantly among all sampling sections. Dispersal barriers strongly influenced coastal cutthroat trout genetic structure and were associated with reduced genetic diversity and increased genetic differentiation. Results indicate that Camp Creek coastal cutthroat trout exist as many small, partially independent populations that are strongly affected by genetic drift. In headwater streams, barriers to movement can result in genetic and demographic isolation leading to reduced coastal cutthroat trout genetic diversity, and potentially compromising long-term population persistence. When habitat fragmentation eliminates gene flow among small populations, similar results may occur in other species.

  19. Host genetic influence on papillomavirus-induced tumors in the horse.

    PubMed

    Staiger, Elizabeth A; Tseng, Chia T; Miller, Donald; Cassano, Jennifer M; Nasir, Lubna; Garrick, Dorian; Brooks, Samantha A; Antczak, Douglas F

    2016-08-15

    The common equine skin tumors known as sarcoids have been causally associated with infection by bovine papillomavirus (BPV). Additionally, there is evidence for host genetic susceptibility to sarcoids. We investigated the genetic basis of susceptibility to sarcoid tumors on a cohort of 82 affected horses and 270 controls genotyped on a genome-wide platform and two custom panels. A Genome Wide Association Study (GWAS) identified candidate regions on six chromosomes. Bayesian probability analysis of the same dataset verified only the regions on equine chromosomes (ECA) 20 and 22. Fine mapping using custom-produced SNP arrays for ECA20 and ECA22 regions identified two marker loci with high levels of significance: SNP BIEC2-530826 (map position 32,787,619) on ECA20 in an intron of the DQA1 gene in the Major Histocompatibility Complex (MHC) class II region (p = 4.6e-06), and SNP BIEC2-589604 (map position 25,951,536) on ECA22 in a 200 kb region containing four candidate genes: PROCR, EDEM2, EIF6 and MMP24 (p = 2.14e-06). The marker loci yielded odds ratios of 5.05 and 4.02 for ECA20 and ECA22, respectively. Associations between genetic MHC class II variants and papillomavirus-induced tumors have been reported for human papillomavirus and cottontail rabbit papillomavirus infections. This suggests a common mechanism for susceptibility to tumor progression that may involve subversion of the host immune response. This study also identified a genomic region other than MHC that influenced papillomavirus-induced tumor development in the studied population. PMID:27037728

  20. Genetic Variation in Autophagy-Related Genes Influences the Risk and Phenotype of Buruli Ulcer

    PubMed Central

    Capela, Carlos; Dossou, Ange Dodji; Silva-Gomes, Rita; Sopoh, Ghislain Emmanuel; Makoutode, Michel; Menino, João Filipe; Fraga, Alexandra Gabriel; Cunha, Cristina; Carvalho, Agostinho; Rodrigues, Fernando; Pedrosa, Jorge

    2016-01-01

    Introduction Buruli ulcer (BU) is a severe necrotizing human skin disease caused by Mycobacterium ulcerans. Clinically, presentation is a sum of these diverse pathogenic hits subjected to critical immune-regulatory mechanisms. Among them, autophagy has been demonstrated as a cellular process of critical importance. Since microtubules and dynein are affected by mycolactone, the critical pathogenic exotoxin produced by M. ulcerans, cytoskeleton-related changes might potentially impair the autophagic process and impact the risk and progression of infection. Objective Genetic variants in the autophagy-related genes NOD2, PARK2 and ATG16L1 has been associated with susceptibility to mycobacterial diseases. Here, we investigated their association with BU risk, its severe phenotypes and its progression to an ulcerative form. Methods Genetic variants were genotyped using KASPar chemistry in 208 BU patients (70.2% with an ulcerative form and 28% in severe WHO category 3 phenotype) and 300 healthy endemic controls. Results The rs1333955 SNP in PARK2 was significantly associated with increased susceptibility to BU [odds ratio (OR), 1.43; P = 0.05]. In addition, both the rs9302752 and rs2066842 SNPs in NOD2 gee significantly increased the predisposition of patients to develop category 3 (OR, 2.23; P = 0.02; and OR 12.7; P = 0.03, respectively, whereas the rs2241880 SNP in ATG16L1 was found to significantly protect patients from presenting the ulcer phenotype (OR, 0.35; P = 0.02). Conclusion Our findings indicate that specific genetic variants in autophagy-related genes influence susceptibility to the development of BU and its progression to severe phenotypes. PMID:27128681

  1. 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

  2. Genetic and Environmental Influences on Female Sexual Orientation, Childhood Gender Typicality and Adult Gender Identity

    PubMed Central

    Burri, Andrea; Cherkas, Lynn; Spector, Timothy; Rahman, Qazi

    2011-01-01

    Background Human sexual orientation is influenced by genetic and non-shared environmental factors as are two important psychological correlates – childhood gender typicality (CGT) and adult gender identity (AGI). However, researchers have been unable to resolve the genetic and non-genetic components that contribute to the covariation between these traits, particularly in women. Methodology/Principal Findings Here we performed a multivariate genetic analysis in a large sample of British female twins (N = 4,426) who completed a questionnaire assessing sexual attraction, CGT and AGI. Univariate genetic models indicated modest genetic influences on sexual attraction (25%), AGI (11%) and CGT (31%). For the multivariate analyses, a common pathway model best fitted the data. Conclusions/Significance This indicated that a single latent variable influenced by a genetic component and common non-shared environmental component explained the association between the three traits but there was substantial measurement error. These findings highlight common developmental factors affecting differences in sexual orientation. PMID:21760939

  3. Multiscale analysis of Hymenocallis coronaria (Amaryllidaceae) genetic diversity, genetic structure, and gene movement under the influence of unidirectional stream flow.

    PubMed

    Markwith, Scott H; Scanlon, Michael J

    2007-02-01

    Understanding gene movement patterns in unidirectional flow environments and their effect on patterns of genetic diversity and genetic structure is necessary to manage these systems. Hypotheses and models to explain genetic patterns in streams are rare, and the results of macrophyte studies are inconsistent. This study addresses Ritland's (Canadian Journal of Botany 67: 2017-2024) unidirectional diversity hypothesis, the one-dimensional stepping stone model, and the metapopulation model within and among populations. Hymenocallis coronaria, an aquatic macrophyte of rocky river shoals of the SE USA, was sampled in four river basins. Within populations and among populations <16.2 km apart had significant isolation by distance. However, the rate of gene flow decay was not consistent with a one-dimensional stepping stone model, nor was evidence strong or consistent for Ritland's hypothesis. Some evidence indicates that localized metapopulation processes may be affecting genetic diversity and structure; however, gene flow patterns inconsistent with the assumptions of the linear and unidirectional models are also a possible influence. We discuss three variants on the one-dimensional stepping stone model. Future research in linear environments should examine the expectations of these models. This study is also one of the first efforts to calculate population genetic parameters using a new program, TETRASAT. PMID:21642217

  4. Population-genetic influences on genomic estimates of the inbreeding coefficient: a global perspective

    PubMed Central

    Pemberton, Trevor J.; Rosenberg, Noah A.

    2014-01-01

    Background/Aims Culturally-driven marital practices provide a key instance of an interaction between social and genetic processes in shaping patterns of human genetic variation, producing, for example, increased identity by descent through consanguineous marriage. A commonly used measure to quantify identity by descent in an individual is the inbreeding coefficient, a quantity that reflects not only consanguinity, but also other aspects of kinship in the population to which the individual belongs. Here, in populations worldwide, we examine the relationship between genomic estimates of the inbreeding coefficient and population patterns in genetic variation. Methods Using genotypes at 645 microsatellites, we compare inbreeding coefficients from 5,043 individuals representing 237 worldwide populations to demographic consanguinity frequency estimates available for 26 populations, as well as to other quantities that can illuminate population-genetic influences on inbreeding coefficients. Results We observe higher inbreeding coefficient estimates in populations and geographic regions with known high levels of consanguinity or genetic isolation, and in populations with an increased effect of genetic drift and decreased genetic diversity with increasing distance from Africa. For the small number of populations with specific consanguinity estimates, we find a correlation between inbreeding coefficients and consanguinity frequency (r=0.349, P=0.040). Conclusions The results emphasize the importance of both consanguinity and population-genetic factors in influencing variation in inbreeding coefficients, and they provide insight into factors useful for assessing the effect of consanguinity on genomic patterns in different populations. PMID:25060268

  5. Influence of group composition of sulfonic acids on properties of sulfonate additives

    SciTech Connect

    Katrenko, T.I.; Bessonova, R.N.; Kuznetsova, M.G.; Potolovskii, L.A.

    1983-05-01

    Three types of sulfonic acids are formed in sulfonation of petroleum oils-- oil-soluble, oil-insoluble, and water-soluble. This study investigates the influence of the different acids on neutral calcium sulfonates. Samples are recovered from As-14 oil. Oil-insoluble synthesis failed. Water-soluble acid did synthesize with a mix of oil- and water-soluble sulfonates. Neutral calcium sulfonates synthesized from oil-soluble had good properties, from oil-insoluble, bad properties. Oil-insoluble sulfonate also has an inverse effect on cleanup, and it interferes with carbonation. These findings will help with improvements in the sulfonate additive manufacturing process.

  6. An Experimental Investigation of the Influence of the Lubricant Viscosity and Additives on Gear Wear

    NASA Technical Reports Server (NTRS)

    Krantz, Timothy L.; Kahraman, Ahmet

    2005-01-01

    The influence of lubricant viscosity and additives on the average wear rate of spur gear pairs was investigated experimentally. The gear specimens of a comprehensive gear durability test program that made use of seven lubricants covering a range of viscosities were examined to measure gear tooth wear. The measured wear was related to the as-manufactured surface roughness, the elastohydrodynamic film thickness, and the experimentally determined contact fatigue lives of the same specimens. In general, the wear rate was found to be inversely proportional to the viscosity of the lubricant and to the lambda ratio (also sometimes called the specific film thickness). The data also show an exponential trend between the average wear rates and the surface fatigue lives. Lubricants with similar viscosities but differing additives and compositions had somewhat differing gear surface fatigue lives and wear rates.

  7. The influence of UV-irradiation on chitosan modified by the tannic acid addition.

    PubMed

    Sionkowska, A; Kaczmarek, B; Gnatowska, M; Kowalonek, J

    2015-07-01

    The influence of UV-irradiation with the wavelength 254 nm on the properties of chitosan modified by the tannic acid addition was studied. Tannic acid was added to chitosan solution in different weight ratios and after solvent evaporation thin films were formed. The properties of the films such as thermal stability, Young modulus, ultimate tensile strength, moisture content, swelling behavior before and after UV-irradiation were measured and compared. Moreover, the surface properties were studied by contact angle measurements and by the use of atomic force microscopy. The results showed that UV-irradiation caused both, the degradation of the specimen and its cross-linking. The surface of the films made of chitosan modified by the addition of tannic acid was altered by UV-irradiation. PMID:26002540

  8. Influence of Biofuel Additions on the Ignition Delay of Single Diesel Fuel Drops

    NASA Astrophysics Data System (ADS)

    Kopeika, A. K.; Golovko, V. V.; Zolotko, A. N.; Raslavičius, L.; Lubarskii, V. M.

    2015-07-01

    The behavior of single drops of two- and three-component mineral diesel fuel blends with ethanol and rapeseed oil methyl ester in a heated atmosphere has been investigated. With the use of the known quasi-stationary approach, the influence of the thermal properties of fuel blend components and their composition on the ignition delay time of the drop has been investigated. It has been established that under inert heating conditions of the drop, additions of low-boiling ethanol to diesel fuel should shorten the duration of the preignition period, and additions of rapeseed oil methyl ester should, on the contrary, prolong it. Analysis of the obtained data has made it possible to determine the optimal composition of the fuel blend for the most economical operation of the diesel. The prognostic estimates made are confirmed by laboratory experiments and bench tests of fuel blends.

  9. Influence of pentavalent dopant addition to polarization and bioactivity of hydroxyapatite.

    PubMed

    Dhal, Jharana; Bose, Susmita; Bandyopadhyay, Amit

    2013-07-01

    Influence of pentavalent tantalum doping in bulk hydroxyapatite (HAp) ceramics has been investigated for polarizability and bioactivity. Phase analysis from X-ray diffraction measurement indicates that increasing dopant concentration decreased the amount of HAp phase and increased β-TCP and/or α-TCP phases during sintering at 1250 °C in a muffle furnace. Results from thermally stimulated depolarization current (TSDC) measurements showed that doping hindered charge storage ability in HAp ceramics, and doped samples stored fewer charge compared to pure HAp. However, doping enhanced wettability of HAp samples, which was improved further due to polarization. In vitro human osteoblast cell-material interaction study revealed an increase in bioactivity due to dopant addition and polarization compared to pure HAp. This increase in bioactivity was attributed to the increase in wettability due to surface charge and dopant addition. PMID:23623133

  10. 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

  11. 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

  12. Influence of a Small Fraction of Individuals with Enhanced Mutations on a Population Genetic Pool

    NASA Astrophysics Data System (ADS)

    Cebrat, S.; Stauffer, D.

    It has been observed that a higher mutation load could be introduced into the genomes of children conceived by assisted reproduction technology (fertilization in-vitro). This generates two effects — slightly higher mutational pressure on the whole genetic pool of population and inhomogeneity of mutation distributions in the genetic pool. Computer simulations of the Penna ageing model suggest that already a small fraction of births with enhanced number of new mutations can negatively influence the whole population.

  13. Influence of Indium Addition on Whisker Mitigation in Electroplated Tin Coatings on Copper Substrates

    NASA Astrophysics Data System (ADS)

    Meinshausen, L.; Bhassyvasantha, S.; Majumdar, B. S.; Dutta, I.

    2016-01-01

    Among many factors that influence whisker nucleation and growth in electroplated tin, it is now well established that small additions of Pb leads to whisker mitigation. To date, a good non-toxic elemental alternative to Pb that would mitigate whiskers remains elusive. In this work, a 50-100 nm In electroplated layer was incorporated into a 1- μm-thick electroplated Sn on a pure Cu substrate. In order to permit diffusion of In into Sn, heat treatments (HTs) between 125°C and 160°C were performed. The diffusion profile of In was altered by varying the dwell times of the HT and by utilizing two variants of In layer deposition, namely, (1) electroplating In at the top of the Sn plating, and (2) by sandwiching the In plating between two Sn layers, each approximately 500 nm thick. Appropriate control samples of pure Sn were utilized to permit valid data on the influence of In on whisker mitigation. Indium additions reduced whisker growth by at least two orders of magnitude following the 160°C treatment, independent of the location of the In layer. X-ray microanalysis of a focused ion beam cross section of the sandwich plating confirmed that In had indeed diffused into the Sn through the 160°C HT and was a likely reason for the mitigation of Sn whiskers.

  14. 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

  15. 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

  16. Developmentally dynamic genome: Evidence of genetic influences on increases and decreases in conduct problems from early childhood to adolescence

    PubMed Central

    Pingault, Jean-Baptiste; Rijsdijk, Frühling; Zheng, Yao; Plomin, Robert; Viding, Essi

    2015-01-01

    The development of conduct problems in childhood and adolescence is associated with adverse long-term outcomes, including psychiatric morbidity. Although genes constitute a proven factor of stability in conduct problems, less is known regarding their role in conduct problems’ developmental course (i.e. systematic age changes, for instance linear increases or decreases).Mothers rated conduct problems from age 4 to 16 years in 10,038 twin pairs from the Twins Early Development Study. Individual differences in the baseline level (.78; 95% CI: .68-.88) and the developmental course of conduct problems (.73; 95% CI: .60-.86) were under high and largely independent additive genetic influences. Shared environment made a small contribution to the baseline level but not to the developmental course of conduct problems. These results show that genetic influences not only contribute to behavioural stability but also explain systematic change in conduct problems. Different sets of genes may be associated with the developmental course versus the baseline level of conduct problems. The structure of genetic and environmental influences on the development of conduct problems suggests that repeated preventive interventions at different developmental stages might be necessary to achieve a long-term impact. PMID:25944445

  17. The genetic influence on radiographic osteoarthritis is site specific at the hand, hip and knee

    PubMed Central

    Li, Q.; Spector, T. D.; Williams, F. M. K.

    2009-01-01

    Objective. To identify whether a shared genetic influence accounts for the occurrence of OA at different skeletal sites. Methods. Multivariate modelling of data on prevalent radiographic OA at the hand (DIP, PIP and CMC joints), hip and knee joints assessed in 992 monozygotic and dizygotic female twin participants from the TwinsUK Registry. Results. OA at all the five joint sites was heritable. Genetic influences were strongly correlated among joints in the hand; however, there was little evidence of common genetic pathways to account for the co-occurrence of OA at the hand, hip and knee. Conclusions. While genetic influences are important in explaining the variation in occurrence of OA at the hand, hip and knee, there is no evidence that common or shared genetic factors determine the occurrence of disease across all these skeletal sites. The findings suggest that there are important aetiological differences in the disease that are site-specific in women. These results have implications for the design of studies examining the genetic basis of OA as well as for strategies aimed at preventing and treating the disease. PMID:19153142

  18. The relative influence of habitat amount and configuration on genetic structure across multiple spatial scales

    PubMed Central

    Millette, Katie L; Keyghobadi, Nusha

    2015-01-01

    Despite strong interest in understanding how habitat spatial structure shapes the genetics of populations, the relative importance of habitat amount and configuration for patterns of genetic differentiation remains largely unexplored in empirical systems. In this study, we evaluate the relative influence of, and interactions among, the amount of habitat and aspects of its spatial configuration on genetic differentiation in the pitcher plant midge, Metriocnemus knabi. Larvae of this species are found exclusively within the water-filled leaves of pitcher plants (Sarracenia purpurea) in a system that is naturally patchy at multiple spatial scales (i.e., leaf, plant, cluster, peatland). Using generalized linear mixed models and multimodel inference, we estimated effects of the amount of habitat, patch size, interpatch distance, and patch isolation, measured at different spatial scales, on genetic differentiation (FST) among larval samples from leaves within plants, plants within clusters, and clusters within peatlands. Among leaves and plants, genetic differentiation appears to be driven by female oviposition behaviors and is influenced by habitat isolation at a broad (peatland) scale. Among clusters, gene flow is spatially restricted and aspects of both the amount of habitat and configuration at the focal scale are important, as is their interaction. Our results suggest that both habitat amount and configuration can be important determinants of genetic structure and that their relative influence is scale dependent. PMID:25628865

  19. Genetic variants influencing effectiveness of weight loss strategies.

    PubMed

    Deram, Sophie; Villares, Sandra M F

    2009-03-01

    Body weight excess has an increasingly high prevalence in the world. Obesity is a complex disease of multifactorial origin with a polygenic condition affected by environmental factors. Weight loss is a primary strategy to treat obesity and its morbidities. Weight changes through life depend on the interaction of environmental, behavioral and genetic factors. Interindividual variation of weight loss in response to different types of interventions (behavioral, caloric restriction, exercise, drug or surgery) has been observed. In this article, currently available data on the role of candidate gene polymorphisms in weight loss are reviewed. Even though control of weight loss by genotype was described in twin and family studies, it is premature to recommend use of genotyping in the design of therapeutic diets or drug treatment. Future studies will have to be large in order to assess the effects of multiple polymorphisms, and will have to control factors other than diet. PMID:19466204

  20. Genetic Influences on the Development of Fibrosis in Crohn’s Disease

    PubMed Central

    Verstockt, Bram; Cleynen, Isabelle

    2016-01-01

    Fibrostenotic strictures are an important complication in patients with Crohn’s disease (CD), very often necessitating surgery. This fibrotic process develops in a genetically susceptible individual and is influenced by an interplay with environmental, immunological, and disease-related factors. A deeper understanding of the genetic factors driving this fibrostenotic process might help to unravel the pathogenesis, and ultimately lead to development of new, anti-fibrotic therapy. Here, we review the genetic factors that have been associated with the development of fibrosis in patients with CD, as well as their potential pathophysiological mechanism(s). We also hypothesize on clinical implications, if any, and future research directions. PMID:27303667

  1. The Structure of the Genetic and Environmental Influences on Mental Well-Being

    PubMed Central

    Myers, John M.; Kendler, Kenneth S.

    2010-01-01

    Objectives. We sought to investigate the structure of the genetic and environmental influences on 3 measures of mental well-being. Methods. Analyses focused on the subsample of 349 monozygotic and 321 dizygotic same-sex twin pairs from a nationally representative sample of twins who completed self-report measures of emotional, psychological, and social well-being. Results. The best-fit model contained a common pathway to all 3 measures of well-being, no shared environmental effects, and 1 set of parameters for men and women. Heritability for the latent “mental well-being” factor was high (72%) and best indexed by psychological well-being. Moderate trait-specific genetic effects were seen for emotional and social well-being. Nonshared environmental effects for all measures were mostly trait specific. Conclusions. Genetic influences on the measures of mental well-being reflect a single, highly heritable genetic factor, although some trait-specific genetic influences were seen for emotional and social well-being. Moderate proportions of environmental influences were also shared, but the majority of unique environment was trait-specific. PMID:20966361

  2. Influence of progressive addition lenses on reading posture in myopic children

    PubMed Central

    Bao, Jinhua; Wang, Yuwen; Zhuo, Zuopao; Yang, Xianling; Tan, Renjing; Drobe, Björn; Chen, Hao

    2016-01-01

    Aims To determine the influence of single-vision lenses (SVLs) and progressive addition lenses (PALs) on the near vision posture of myopic children based on their near phoria. Methods Sixty-two myopic children were assigned to wear SVLs followed by PALs. Eighteen children were esophoric (greater than +1), 18 were orthophoric (−1 to 1) and 26 were exophoric (less than −1) at near. Reading distance, head tilt and ocular gaze angles were measured using an electromagnetic system after adaptation to each lens type. Results The lens type did not influence reading distance or head tilt angle (p>0.05 for both), but ocular gaze angle decreased significantly with the PALs (F=9.25, p=0.004). With the PALs, exophoric children exhibited significantly increased head tilt angle (p=0.003) and reduced ocular gaze angle (p=0.004) compared with esophoric children. Near non-exophoric children exhibited similar eye and head postures when wearing SVLs and PALs, whereas exophoric children exhibited reduced ocular gaze angle (t=−3.18, p=0.04) with PALs compared with SVLs. Using PALs for reading, the mean addition power employed by esophoric children was significantly greater than exophoric children (p=0.04). Conclusions The lens type and the near phoria state affected near vision posture. During reading, myopic esophoric children used a lower portion of their PALs compared with exophoric children, resulting in greater addition power. These results may partially explain why myopic children with near esophoria exhibited superior treatment effects in myopia control trials using PALs. PMID:26608026

  3. Influence of Alumina Addition to Aluminum Fins for Compact Heat Exchangers Produced by Cold Spray Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Farjam, Aslan; Cormier, Yannick; Dupuis, Philippe; Jodoin, Bertrand; Corbeil, Antoine

    2015-10-01

    In this work, aluminum and aluminum-alumina powder mixtures were used to produce pyramidal fin arrays on aluminum substrates using cold spray as an additive manufacturing process. Using aluminum-alumina mixtures instead of pure aluminum powder could be seen as a cost-effective measure, preventing nozzle clogging or the need to use expensive polymer nozzles that wear out rapidly during cold spray. The fin geometries that were produced were observed using a 3D digital microscope to determine the flow passages width and fins' geometric details. Heat transfer and pressure drop tests were carried out using different ranges of appropriate Reynolds numbers for the sought commercial application to compare each fin array and determine the effect of alumina content. It was found that the presence of alumina reduces the fins' performance when compared to pure aluminum fins but that they were still outperforming traditional fins. Numerical simulations were performed to model the fin arrays and were used to predict the pressure loss in the fin array and compare these results with experimental values. The numerical model opens up new avenues in predicting different applicable operating conditions and other possible fin shapes using the same fin composition, instead of performing costly and time-consuming experiments.

  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 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

  5. 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

  6. Understanding the cognitive and genetic underpinnings of procrastination: Evidence for shared genetic influences with goal management and executive function abilities.

    PubMed

    Gustavson, Daniel E; Miyake, Akira; Hewitt, John K; Friedman, Naomi P

    2015-12-01

    Previous research has suggested that individual differences in procrastination are tied to everyday goal-management abilities, but little research has been conducted on specific cognitive abilities that may underlie tendencies for procrastination, such as executive functions (EFs). In this study, we used behavioral genetics methodology to investigate 2 hypotheses about the relationships between procrastination and EF ability: (a) that procrastination is negatively correlated with general EF ability, and (b) that this relationship is due to the genetic components of procrastination that are most related to other everyday goal-management abilities. The results confirmed both of these hypotheses. Procrastination was related to worse general EF ability at both the phenotypic and genetic levels, and this relationship was due to the component of procrastination shared with self-report measures of everyday goal-management failures. These results were observed even after controlling for potential self-report biases stemming from the urge to respond in a socially desirable manner. Together, these findings provide strong evidence for growing theories of procrastination emphasizing the importance of goal-related cognitive abilities and further highlight important genetic influences that underlie procrastination. PMID:26389573

  7. Sulfur and nitrogen uptake by loblolly pine seedlings as influenced by nitrogen and sulfur addition

    SciTech Connect

    Kelly, J.M.; Johnson, D.W.

    1982-12-01

    The influence of increasing levels of nitrogen addition at several levels of sulfur input on nitrogen and sulfur uptake by loblolly pine seedlings was evaluated in a greenhouse study. All possible combinations on nitrogen and sulfur were incorporated into soil collected from the A horizon of a southeastern forest soil at rates of 0, 200, 500, and 1,000 ..mu..g/g of N, and 0, 14, 35, and 70 ..mu..g/g of S. Soil samples collected at the end of the study indicated that a similar amount of soil SO/sub 4/-S had been mineralized in all treatment combinations, compared to a general pattern of increasing soil nitrogen mineralization with increasing nitrogen input. Most mineralized sulfate appeared to come from nonprotein organic compounds as there was not a significant concomitant release of nitrogen. Both shoot and root biomass responded significantly to nitrogen addition, but there was no sulfur or nitrogen-sulfur interaction response. Nitrogen treatment generally increased shoot nitrogen concentration compared to a general decrease in shoot total-, sulfate-, and organically bound-sulfur. Organically bound-sulfur concentrations were 26 to 60 percent below sulfur values calculated from an S/N ratio of 0.03 on a gram atom basis. The results show that increased nitrogen addition affected both growth and sulfur status of loblolly pine seedlings, but not entirely in the manner predicted by theoretical considerations.

  8. Sulfur and nitrogen uptake by loblolly pine seedlings as influenced by nitrogen and sulfur addition

    SciTech Connect

    Kelly, J.M.; Johnson, D.W.

    1982-12-01

    The influence of increasing levels of nitrogen addition at several levels of sulfur input on nitrogen and sulfur uptake by loblolly pine seedlings was evaluated in a greenhouse study. All possible combinations of nitrogen and sulfur were incorporated into soil collected from the A horizon of a southeastern forest soil at rates of 0, 200, 500, and 1,000 ..mu..g/g of N, and 0, 14, 35, and 70 ..mu..g/g of S. Soil samples collected at the end of the study indicated that a similar amount of soil SO/sub 4/-S had been mineralized in all treatment combinations, compared to a general pattern of increasing soil nitrogen mineralization with increasing nitrogen input. Most mineralized sulfate appeared to come from nonprotein organic compounds as there was not a significant concomitant release of nitrogen. Both shoot and root biomass responded significantly to nitrogen addition, but there was no sulfur or nitrogen-sulfur interaction response. Nitrogen treatment generally increased shoot nitrogen concentration compared to a general decrease in shoot total-, sulfate-, and organically bound-sulfur. Organically bound-sulfur concentrations were 26 to 60 percent below sulfur values calculated from an S/N ratio of 0.03 on a gram atom basis. The results show that increased nitrogen addition affected both growth and sulfur status of loblolly pine seedlings, but not entirely in the manner predicted by theoretical considerations.

  9. Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm.

    PubMed

    da Silva Carvalho, C; Ribeiro, M C; Côrtes, M C; Galetti, M; Collevatti, R G

    2015-09-01

    Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes. PMID:25873150

  10. Contemporary and historic factors influence differently genetic differentiation and diversity in a tropical palm

    PubMed Central

    da Silva Carvalho, C; Ribeiro, M C; Côrtes, M C; Galetti, M; Collevatti, R G

    2015-01-01

    Population genetics theory predicts loss in genetic variability because of drift and inbreeding in isolated plant populations; however, it has been argued that long-distance pollination and seed dispersal may be able to maintain gene flow, even in highly fragmented landscapes. We tested how historical effective population size, historical migration and contemporary landscape structure, such as forest cover, patch isolation and matrix resistance, affect genetic variability and differentiation of seedlings in a tropical palm (Euterpe edulis) in a human-modified rainforest. We sampled 16 sites within five landscapes in the Brazilian Atlantic forest and assessed genetic variability and differentiation using eight microsatellite loci. Using a model selection approach, none of the covariates explained the variation observed in inbreeding coefficients among populations. The variation in genetic diversity among sites was best explained by historical effective population size. Allelic richness was best explained by historical effective population size and matrix resistance, whereas genetic differentiation was explained by matrix resistance. Coalescence analysis revealed high historical migration between sites within landscapes and constant historical population sizes, showing that the genetic differentiation is most likely due to recent changes caused by habitat loss and fragmentation. Overall, recent landscape changes have a greater influence on among-population genetic variation than historical gene flow process. As immediate restoration actions in landscapes with low forest amount, the development of more permeable matrices to allow the movement of pollinators and seed dispersers may be an effective strategy to maintain microevolutionary processes. PMID:25873150

  11. Environmental factors influence both abundance and genetic diversity in a widespread bird species

    PubMed Central

    Liu, Yang; Webber, Simone; Bowgen, Katharine; Schmaltz, Lucie; Bradley, Katharine; Halvarsson, Peter; Abdelgadir, Mohanad; Griesser, Michael

    2013-01-01

    Genetic diversity is one of the key evolutionary variables that correlate with population size, being of critical importance for population viability and the persistence of species. Genetic diversity can also have important ecological consequences within populations, and in turn, ecological factors may drive patterns of genetic diversity. However, the relationship between the genetic diversity of a population and how this interacts with ecological processes has so far only been investigated in a few studies. Here, we investigate the link between ecological factors, local population size, and allelic diversity, using a field study of a common bird species, the house sparrow (Passer domesticus). We studied sparrows outside the breeding season in a confined small valley dominated by dispersed farms and small-scale agriculture in southern France. Population surveys at 36 locations revealed that sparrows were more abundant in locations with high food availability. We then captured and genotyped 891 house sparrows at 10 microsatellite loci from a subset of these locations (N = 12). Population genetic analyses revealed weak genetic structure, where each locality represented a distinct substructure within the study area. We found that food availability was the main factor among others tested to influence the genetic structure between locations. These results suggest that ecological factors can have strong impacts on both population size per se and intrapopulation genetic variation even at a small scale. On a more general level, our data indicate that a patchy environment and low dispersal rate can result in fine-scale patterns of genetic diversity. Given the importance of genetic diversity for population viability, combining ecological and genetic data can help to identify factors limiting population size and determine the conservation potential of populations. PMID:24363897

  12. Tailoring of Boehmite-Derived Aluminosilicate Aerogel Structure and Properties: Influence of Ti Addition

    NASA Technical Reports Server (NTRS)

    Hurwitz, Frances I.; Guo, Haiquan; Sheets, Erik J.; Miller, Derek R.; Newlin, Katy N.

    2010-01-01

    Aluminosilicate aerogels offer potential for extremely low thermal conductivities at temperatures greater than 900 C, beyond where silica aerogels reach their upper temperature limits. Aerogels have been synthesized at various Al:Si ratios, including mullite compositions, using Boehmite (AlOOH) as the Al source, and tetraethoxy orthosilicate as the Si precursor. The Boehmite-derived aerogels are found to form by a self-assembly process of AlOOH crystallites, with Si-O groups on the surface of an alumina skeleton. Morphology, surface area and pore size varies with the crystallite size of the starting Boehmite powder, as well as with synthesis parameters. Ternary systems, including Al-Si-Ti aerogels incorporating a soluble Ti precursor, are possible with careful control of pH. The addition of Ti influences sol viscosity, gelation time pore structure and pore size distribution, as well as phase formation on heat treatment.

  13. Influence of metal surface and sulfur addition on coke deposition in the thermal cracking of hydrocarbons

    SciTech Connect

    Reyniers, M.F.S.G.; Froment, G.F.

    1995-03-01

    Coke formation in the thermal cracking of hydrocarbons was studied in a pilot plant unit and in a microreactor with complete mixing of the gas phase, containing a hollow cylinder suspended at the arm of an electrobalance. The morphology of the coke was studied by SEM, while EDX was used to determine the concentration of metals in the coke layer. The influence of the metal surface composition, of it pretreatment, and of the addition of various sulfur compounds on the coking rate and CO production was investigated for condition typical for those in the cracking coil. The CO yield is not a measure of the coking rate. Sulfur compounds are very efficient in reducing the CO yield but promote coke formation.

  14. Genetic and non-genetic influences during pregnancy on infant global and site specific DNA methylation: role for folate gene variants and vitamin B12.

    PubMed

    McKay, Jill A; Groom, Alexandra; Potter, Catherine; Coneyworth, Lisa J; Ford, Dianne; Mathers, John C; Relton, Caroline L

    2012-01-01

    Inter-individual variation in patterns of DNA methylation at birth can be explained by the influence of environmental, genetic and stochastic factors. This study investigates the genetic and non-genetic determinants of variation in DNA methylation in human infants. Given its central role in provision of methyl groups for DNA methylation, this study focuses on aspects of folate metabolism. Global (LUMA) and gene specific (IGF2, ZNT5, IGFBP3) DNA methylation were quantified in 430 infants by Pyrosequencing®. Seven polymorphisms in 6 genes (MTHFR, MTRR, FOLH1, CβS, RFC1, SHMT) involved in folate absorption and metabolism were analysed in DNA from both infants and mothers. Red blood cell folate and serum vitamin B(12) concentrations were measured as indices of vitamin status. Relationships between DNA methylation patterns and several covariates viz. sex, gestation length, maternal and infant red cell folate, maternal and infant serum vitamin B(12), maternal age, smoking and genotype were tested. Length of gestation correlated positively with IGF2 methylation (rho = 0.11, p = 0.032) and inversely with ZNT5 methylation (rho = -0.13, p = 0.017). Methylation of the IGFBP3 locus correlated inversely with infant vitamin B(12) concentration (rho = -0.16, p = 0.007), whilst global DNA methylation correlated inversely with maternal vitamin B(12) concentrations (rho = 0.18, p = 0.044). Analysis of common genetic variants in folate pathway genes highlighted several associations including infant MTRR 66G>A genotype with DNA methylation (χ(2) = 8.82, p = 0.003) and maternal MTHFR 677C>T genotype with IGF2 methylation (χ(2) = 2.77, p = 0.006). These data support the hypothesis that both environmental and genetic factors involved in one-carbon metabolism influence DNA methylation in infants. Specifically, the findings highlight the importance of vitamin B(12) status, infant MTRR genotype and maternal MTHFR genotype, all of which may influence the supply of methyl groups for DNA

  15. The influence of heat accumulation on the surface roughness in powder-bed additive manufacturing

    NASA Astrophysics Data System (ADS)

    Jamshidinia, Mahdi; Kovacevic, Radovan

    2015-03-01

    The influence of heat accumulation on surface roughness during powder-bed additive manufacturing was investigated. A series of Ti-6Al-4V thin plates were produced by using an identical heat input by electron beam melting® (EBM). Spacing distances of 5 mm, 10 mm, and 20 mm were used. The surface roughness of as-built thin plates was measured using a two-axis profilometer. A numerical model was developed to study the influence of spacing distance on heat accumulation. An inverse relationship between the spacing distance and surface roughness was revealed. The experimental and numerical results showed that the surface quality of buildups could be controlled not only by process parameters, but also by the arrangement of components in the buildup chamber. At a constant spacing distance, an increase in the number of powder layers resulted in the accumulation of more heat between the thin plates. An increase in the spacing distance resulted in an upward translation of the Bearing Area Curve (BAC) toward shallower depths, with a reduced core roughness depth (Rk) and peak height (Rpk). A logarithmic regression equation was established from the experimental data. This equation could be used to predict the surface roughness of parts fabricated by EBM® in the studied range of spacing distances.

  16. Shared and unique genetic and environmental influences on aging-related changes in multiple cognitive abilities.

    PubMed

    Tucker-Drob, Elliot M; Reynolds, Chandra A; Finkel, Deborah; Pedersen, Nancy L

    2014-01-01

    Aging-related declines occur in many different domains of cognitive function during middle and late adulthood. However, whether a global dimension underlies individual differences in changes in different domains of cognition and whether global genetic influences on cognitive changes exist is less clear. We addressed these issues by applying multivariate growth curve models to longitudinal data from 857 individuals from the Swedish Adoption/Twin Study of Aging, who had been measured on 11 cognitive variables representative of verbal, spatial, memory, and processing speed abilities up to 5 times over up to 16 years between ages 50 and 96 years. Between ages 50 and 65 years scores on different tests changed relatively independently of one another, and there was little evidence for strong underlying dimensions of change. In contrast, over the period between 65 and 96 years of age, there were strong interrelations among rates of change both within and across domains. During this age period, variability in rates of change were, on average, 52% domain-general, 8% domain-specific, and 39% test-specific. Quantitative genetic decomposition indicated that 29% of individual differences in a global domain-general dimension of cognitive changes during this age period were attributable to genetic influences, but some domain-specific genetic influences were also evident, even after accounting for domain-general contributions. These findings are consistent with a balanced global and domain-specific account of the genetics of cognitive aging. PMID:23586942

  17. Genetically influenced change in sensation seeking drives the rise of delinquent behavior during adolescence.

    PubMed

    Harden, K Paige; Quinn, Patrick D; Tucker-Drob, Elliot M

    2012-01-01

    Sensation seeking is associated with an increased propensity for delinquency, and emerging research on personality change suggests that mean levels of sensation seeking increase substantially from childhood to adolescence. The current study tested whether individual differences in the rate of change of sensation seeking predicted within-person change in delinquent behavior and whether genetically influenced differences in rate of personality change accounted for this association. Sensation seeking and delinquent behavior were assessed biennially between ages 10-11 and 16-17 in a nationally representative sample of 7675 youths from the National Longitudinal Study of Youth: Children and Young Adults (CNLSY). Analyses using latent growth curve modeling found that within-person change in sensation seeking was significantly and positively correlated with within-person change in delinquency from childhood to adolescence. Furthermore, behavioral genetic analyses of a subset of 2562 sibling pairs indicated that there were substantial genetic influences on both initial levels of sensation seeking and change in sensation seeking during early adolescence, with over 80% of individual differences in change due to genetic factors. Finally, these genetically driven increases in sensation seeking were most important for predicting increases in delinquency, whereas environmental paths between sensation seeking and delinquency were not significant. These results suggest that developmental changes in delinquent behaviors during adolescence are driven by a genetically governed process of personality change. PMID:22251301

  18. Seasonal flooding regime and ecological traits influence genetic structure of two small rodents

    PubMed Central

    Rocha, Rita Gomes; Ferreira, Eduardo; Fonseca, Carlos; Justino, Juliana; Leite, Yuri Luiz Reis; Costa, Leonora Pires

    2014-01-01

    Although codistributed species are affected by the same abiotic factors, such as rivers and seasonal flooding regimes, ecological traits, such as locomotion habits and habitat preferences, may also influence differences in levels of genetic diversity and differentiation. We examined population genetic structure and diversity of Hylaeamys megacephalus and Oecomys aff. roberti, two cricetid rodent species from the mid-Araguaia River in central Brazil, using mitochondrial DNA sequence data. Specifically, we aim to test whether the Araguaia River acts as a barrier to the gene flow of these two species and to assess how ecological traits, such as locomotion habits and habitat preferences, may influence differences in levels of genetic diversity and differentiation. As both species occur in flooded forests, neither showed genetic differences related to river banks. Oecomys aff. roberti showed stronger population structure that appears to be associated with isolation by distance. This arboreal species maintained stable populations in the Araguaia River, while the terrestrial H. megacephalus was more affected by seasonal floods, resulting in a genetic signature of population expansion. Our initial predictions were largely supported by our results given that locomotion habits and habitat preferences of each species appears to have played a role on the genetic structure of these two sympatric rodent species. PMID:25558355

  19. Seasonal flooding regime and ecological traits influence genetic structure of two small rodents.

    PubMed

    Rocha, Rita Gomes; Ferreira, Eduardo; Fonseca, Carlos; Justino, Juliana; Leite, Yuri Luiz Reis; Costa, Leonora Pires

    2014-12-01

    Although codistributed species are affected by the same abiotic factors, such as rivers and seasonal flooding regimes, ecological traits, such as locomotion habits and habitat preferences, may also influence differences in levels of genetic diversity and differentiation. We examined population genetic structure and diversity of Hylaeamys megacephalus and Oecomys aff. roberti, two cricetid rodent species from the mid-Araguaia River in central Brazil, using mitochondrial DNA sequence data. Specifically, we aim to test whether the Araguaia River acts as a barrier to the gene flow of these two species and to assess how ecological traits, such as locomotion habits and habitat preferences, may influence differences in levels of genetic diversity and differentiation. As both species occur in flooded forests, neither showed genetic differences related to river banks. Oecomys aff. roberti showed stronger population structure that appears to be associated with isolation by distance. This arboreal species maintained stable populations in the Araguaia River, while the terrestrial H. megacephalus was more affected by seasonal floods, resulting in a genetic signature of population expansion. Our initial predictions were largely supported by our results given that locomotion habits and habitat preferences of each species appears to have played a role on the genetic structure of these two sympatric rodent species. PMID:25558355

  20. Genetic and environmental influences on factors associated with cardiovascular disease and the metabolic syndrome

    PubMed Central

    Elder, Sonya J.; Lichtenstein, Alice H.; Pittas, Anastassios G.; Roberts, Susan B.; Fuss, Paul J.; Greenberg, Andrew S.; McCrory, Megan A.; Bouchard, Thomas J.; Saltzman, Edward; Neale, Michael C.

    2009-01-01

    The relative influence of genetics and the environment on factors associated with cardiovascular disease (CVD) and metabolic syndrome (MetS) remains unclear. We performed model-fitting analyses to quantify genetic, common environmental, and unique environmental variance components of factors associated with CVD and MetS [waist circumference, blood pressure, fasting plasma glucose and insulin, homeostatic model assessment of insulin resistance (HOMA-IR), and fasting plasma lipids] in adult male and female monozygotic twins reared apart or together. We also investigated whether MetS components share common influences. Plasma cholesterol and triglyceride concentrations were highly heritable (56–77%, statistically significant). Waist circumference, plasma glucose and insulin, HOMA-IR, and blood pressure were moderately heritable (43–57%, statistically significant). Unique environmental factors contributed to the variance of all variables (20–38%, perforce statistically significant). Common environmental factors contributed 23, 30, and 42% (statistically significant) of the variance of waist circumference, systolic blood pressure, and plasma glucose, respectively. Two shared factors influenced MetS components; one influenced all components except HDL cholesterol, another influenced only lipid (triglyceride and HDL cholesterol) concentrations. These results suggest that genetic variance has a dominant influence on total variance of factors associated with CVD and MetS and support the proposal of one or more underlying pathologies of MetS. PMID:19372593

  1. Influence of hydroxypropylmethylcellulose addition and homogenization conditions on properties and ageing of corn starch based films.

    PubMed

    Jiménez, Alberto; Fabra, María José; Talens, Pau; Chiralt, Amparo

    2012-06-20

    Edible films based on corn starch, hydroxypropyl methylcellulose (HPMC) and their mixtures were prepared by using two different procedures to homogenize the film forming dispersions (rotor-stator and rotor-stator plus microfluidizer). The influence of both HPMC-starch ratio and the homogenization method on the structural, optical, tensile and barrier properties of the films was analysed. The ageing of the films was also studied by characterizing them after 5 weeks' storage. Starch re-crystallization in newly prepared and stored films was analysed by means of X-ray diffraction. HPMC-corn starch films showed phase separation of polymers, which was enhanced when microfluidization was applied to the film forming dispersion. Nevertheless, HPMC addition inhibited starch re-crystallization during storage, giving rise to more flexible films at the end of the period. Water barrier properties of starch films were hardly affected by the addition of HPMC, although oxygen permeability increased due to its poorer oxygen barrier properties. PMID:24750773

  2. Influence of oxygen partial pressure and silver additions on microstructure and related properties of YBCO superconductors

    SciTech Connect

    Singh, J.P.; Joo, J.; Guttschow, R.; Poeppel, R.B.

    1992-02-01

    Microstructure has a great influence on the mechanical and superconducting properties of YBCO. Mechanical properties of YBCO can be improved by both modifying the monolithic microstructure and developing composites of YBCO with silver (Ag). When monolithic YBCO was sintered to high densities ({approx} 91%) at a relatively low temperature ({approx} 910{degrees}C) by controlling oxygen partial pressure during sintering, the result was a small-grain microstructure (average grain size {approx} 5 {mu}m) and hence a high strength of 191 {plus minus} 7 MPa. Addition of Ag as a second phase further improved the strength of YBCO. Composites of YBCO with 10 to 15 vol % Ag has a strength of 225 {plus minus} 6 MPa and a fracture toughness of 3.3 {plus minus} 0.2 MPa{radical}m. These improvements are believed to be due to compressive stresses in the YBCO matrix as a result of thermal mismatch between the YBCO and Ag phases. Furthermore, the Ag particles may provide increased resistance to crack propagation by pinning the crack. On the other hand, addition of Ag as a dopant to substitute for Cu sites in YBCO has a profound but nonmonotonic effect on grain microstructure and the resulting critical current density.

  3. Influence of oxygen partial pressure and silver additions on microstructure and related properties of YBCO superconductors

    SciTech Connect

    Singh, J.P.; Joo, J.; Guttschow, R.; Poeppel, R.B.

    1992-02-01

    Microstructure has a great influence on the mechanical and superconducting properties of YBCO. Mechanical properties of YBCO can be improved by both modifying the monolithic microstructure and developing composites of YBCO with silver (Ag). When monolithic YBCO was sintered to high densities ({approx} 91%) at a relatively low temperature ({approx} 910{degrees}C) by controlling oxygen partial pressure during sintering, the result was a small-grain microstructure (average grain size {approx} 5 {mu}m) and hence a high strength of 191 {plus_minus} 7 MPa. Addition of Ag as a second phase further improved the strength of YBCO. Composites of YBCO with 10 to 15 vol % Ag has a strength of 225 {plus_minus} 6 MPa and a fracture toughness of 3.3 {plus_minus} 0.2 MPa{radical}m. These improvements are believed to be due to compressive stresses in the YBCO matrix as a result of thermal mismatch between the YBCO and Ag phases. Furthermore, the Ag particles may provide increased resistance to crack propagation by pinning the crack. On the other hand, addition of Ag as a dopant to substitute for Cu sites in YBCO has a profound but nonmonotonic effect on grain microstructure and the resulting critical current density.

  4. Genetic and environmental influences on risky sexual behaviour and its relationship with personality.

    PubMed

    Zietsch, B P; Verweij, K J H; Bailey, J M; Wright, M J; Martin, N G

    2010-01-01

    Risky sexual behaviour is a major health issue in society, and it is therefore important to understand factors that may predispose individuals to such behaviour. Research suggests a link between risky sexual behaviour and personality, but the basis of this link remains unknown. Hans Eysenck proposed that personality is related to sexual behaviour via biological underpinnings of both. Here we test the viability of this perspective by analysing data from identical and non-identical twins (N = 4,904) who completed a questionnaire assessing sexual attitudes and behaviour as well as personality. Using genetic modelling of the twin data, we found that risky sexual behaviour was significantly positively correlated with Impulsivity (r = .27), Extraversion (r = .24), Psychoticism (r = .20), and Neuroticism (r = .09), and that in each case the correlation was due primarily to overlapping genetic influences. These findings suggest that the genetic influences that shape our personality may also predispose us to risky sexual behaviour. PMID:19813084

  5. Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD

    PubMed Central

    Drummond, M. Bradley; Hawkins, Gregory A.; Yang, Jenny; Chen, Ting-huei; Quibrera, Pedro Miguel; Anderson, Wayne; Barr, R. Graham; Bleecker, Eugene R.; Beaty, Terri; Casaburi, Richard; Castaldi, Peter; Cho, Michael H.; Comellas, Alejandro; Crapo, James D.; Criner, Gerard; Demeo, Dawn; Christenson, Stephanie A.; Couper, David J.; Doerschuk, Claire M.; Freeman, Christine M.; Gouskova, Natalia A.; Han, MeiLan K.; Hanania, Nicola A.; Hansel, Nadia N.; Hersh, Craig P.; Hoffman, Eric A.; Kaner, Robert J.; Kanner, Richard E.; Kleerup, Eric C.; Lutz, Sharon; Martinez, Fernando J.; Meyers, Deborah A.; Peters, Stephen P.; Regan, Elizabeth A.; Rennard, Stephen I.; Scholand, Mary Beth; Silverman, Edwin K.; Woodruff, Prescott G.; O’Neal, Wanda K.; Bowler, Russell P.

    2016-01-01

    Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p < 8 X 10−10) pQTLs in 38 (43%) of blood proteins tested. Most pQTL SNPs were novel with low overlap to eQTL SNPs. The pQTL SNPs explained >10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10−392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In

  6. Common Genetic Polymorphisms Influence Blood Biomarker Measurements in COPD.

    PubMed

    Sun, Wei; Kechris, Katerina; Jacobson, Sean; Drummond, M Bradley; Hawkins, Gregory A; Yang, Jenny; Chen, Ting-Huei; Quibrera, Pedro Miguel; Anderson, Wayne; Barr, R Graham; Basta, Patricia V; Bleecker, Eugene R; Beaty, Terri; Casaburi, Richard; Castaldi, Peter; Cho, Michael H; Comellas, Alejandro; Crapo, James D; Criner, Gerard; Demeo, Dawn; Christenson, Stephanie A; Couper, David J; Curtis, Jeffrey L; Doerschuk, Claire M; Freeman, Christine M; Gouskova, Natalia A; Han, MeiLan K; Hanania, Nicola A; Hansel, Nadia N; Hersh, Craig P; Hoffman, Eric A; Kaner, Robert J; Kanner, Richard E; Kleerup, Eric C; Lutz, Sharon; Martinez, Fernando J; Meyers, Deborah A; Peters, Stephen P; Regan, Elizabeth A; Rennard, Stephen I; Scholand, Mary Beth; Silverman, Edwin K; Woodruff, Prescott G; O'Neal, Wanda K; Bowler, Russell P

    2016-08-01

    Implementing precision medicine for complex diseases such as chronic obstructive lung disease (COPD) will require extensive use of biomarkers and an in-depth understanding of how genetic, epigenetic, and environmental variations contribute to phenotypic diversity and disease progression. A meta-analysis from two large cohorts of current and former smokers with and without COPD [SPIROMICS (N = 750); COPDGene (N = 590)] was used to identify single nucleotide polymorphisms (SNPs) associated with measurement of 88 blood proteins (protein quantitative trait loci; pQTLs). PQTLs consistently replicated between the two cohorts. Features of pQTLs were compared to previously reported expression QTLs (eQTLs). Inference of causal relations of pQTL genotypes, biomarker measurements, and four clinical COPD phenotypes (airflow obstruction, emphysema, exacerbation history, and chronic bronchitis) were explored using conditional independence tests. We identified 527 highly significant (p < 8 X 10-10) pQTLs in 38 (43%) of blood proteins tested. Most pQTL SNPs were novel with low overlap to eQTL SNPs. The pQTL SNPs explained >10% of measured variation in 13 protein biomarkers, with a single SNP (rs7041; p = 10-392) explaining 71%-75% of the measured variation in vitamin D binding protein (gene = GC). Some of these pQTLs [e.g., pQTLs for VDBP, sRAGE (gene = AGER), surfactant protein D (gene = SFTPD), and TNFRSF10C] have been previously associated with COPD phenotypes. Most pQTLs were local (cis), but distant (trans) pQTL SNPs in the ABO blood group locus were the top pQTL SNPs for five proteins. The inclusion of pQTL SNPs improved the clinical predictive value for the established association of sRAGE and emphysema, and the explanation of variance (R2) for emphysema improved from 0.3 to 0.4 when the pQTL SNP was included in the model along with clinical covariates. Causal modeling provided insight into specific pQTL-disease relationships for airflow obstruction and emphysema. In

  7. Genetic influences on blood lipids and cardiovascular disease risk: tools for primary prevention

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic polymorphism in the human population is part of the evolutionary process that results from the interaction between the environment and the human genome. Recent changes in diet have upset this equilibrium, potentially influencing the risk of most common morbidities such as cardiovascular dise...

  8. Common Genetic and Environmental Influences on Major Depressive Disorder and Conduct Disorder

    ERIC Educational Resources Information Center

    Subbarao, Anjali; Rhee, Soo Hyun; Young, Susan E.; Ehringer, Marissa A.; Corley, Robin P.; Hewitt, John K.

    2008-01-01

    The evidence for common genetic and environmental influences on conduct disorder (CD) and major depressive disorder (MDD) in adolescents was examined. A sample of 570 monozygotic twin pairs, 592 dizygotic twin pairs, and 426 non-twin siblings, aged 12-18 years, was recruited from the Colorado Twin Registry. For the past year data, there was a…

  9. Genetic and Environmental Influences on Extreme Personality Dispositions in Adolescent Female Twins

    ERIC Educational Resources Information Center

    Pergadia, Michele L.; Madden, Pamela A. F.; Lessov, Christina N.; Todorov, Alexandre A.; Bucholz, Kathleen K.; Martin, Nicholas G.; Heath, Andrew C.

    2006-01-01

    Background: The objective was to determine whether the pattern of environmental and genetic influences on deviant personality scores differs from that observed for the normative range of personality, comparing results in adolescent and adult female twins. Methods: A sample of 2,796 female adolescent twins ascertained from birth records provided…

  10. Shared and Unique Genetic and Environmental Influences on Aging-Related Changes in Multiple Cognitive Abilities

    ERIC Educational Resources Information Center

    Tucker-Drob, Elliot M.; Reynolds, Chandra A.; Finkel, Deborah; Pedersen, Nancy L.

    2014-01-01

    Aging-related declines occur in many different domains of cognitive function during middle and late adulthood. However, whether a global dimension underlies individual differences in changes in different domains of cognition and whether global genetic influences on cognitive changes exist is less clear. We addressed these issues by applying…

  11. Genetic and Environmental Influences on the Association between Pubertal Maturation and Internalizing Symptoms

    ERIC Educational Resources Information Center

    Marceau, Kristine; Neiderhiser, Jenae M.; Lichtenstein, Paul; Reiss, David

    2012-01-01

    The literature consistently shows an association between pubertal maturation and internalizing problems in girls. The association for boys is less clear. The present study examines genetic and environmental influences on the association between pubertal maturation and internalizing problems for boys and girls in two primarily Caucasian adolescent…

  12. Genetic and Environmental Influences on Conduct Disorder: Symptom, Domain and Full-Scale Analyses

    ERIC Educational Resources Information Center

    Gelhorn, Heather L.; Stallings, Michael C.; Young, Susan E.; Corley, Robin P.; Rhee, Soo Hyun; Hewitt, John K.

    2005-01-01

    Background: We used variable threshold models which accounted for age and gender differences to investigate the genetic and environmental influences on DSM-IV conduct disorder (CD) at the level of symptoms, aggressive versus non-aggressive domains, and full-scale. Method: A community sample of 1100 twin pairs (age 11-18) was interviewed using the…

  13. Common and Specific Genetic Influences on Aggressive and Nonaggressive Conduct Disorder Domains

    ERIC Educational Resources Information Center

    Gelhorn, Heather; Stallings, Michael; Young, Susan; Corley, Robin; Rhee, Soo Hyun; Hopfer, Christian; Hewitt, John

    2006-01-01

    Objective: To explore the genetic and environmental influences on DSM-IV conduct disorder (CD) aggressive and nonaggressive subscales, taking into account age and sex differences. Method: A community sample of 1,100 twin pairs (ages 11-18) was interviewed using the Diagnostic Interview Schedule for Children. Bivariate analyses, using variable…

  14. The Structure of Genetic Influences on General Cognitive, Language, Phonological, and Reading Abilities.

    ERIC Educational Resources Information Center

    Hohnen, Bettina; Stevenson, Jim

    1999-01-01

    Examined the etiology of individual differences in literacy, phonological awareness, and language ability in monozygotic and dizygotic twins. Found that there was no genetic link between phonological awareness and literacy independent of general language ability. Individual differences in literacy ability were substantially influenced by genetics…

  15. Cognitive performance and BMI in childhood: Shared genetic influences between reaction time but not response inhibition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The aim of this work is to understand whether shared genetic influences can explain the associationbetween obesity and cognitive performance, including slower and more variable reaction times(RTs) and worse response inhibition. RT on a four-choice RT task and the go/no-go task, and commission errors...

  16. Genetic and Environmental Influences on Mothering of Adolescents: A Comparison of Two Samples

    ERIC Educational Resources Information Center

    Neiderhiser, Jenae M.; Reiss, David; Pedersen, Nancy L.; Lichtenstein, Paul; Spotts, Erica L.; Hansson, Kjell; Cederblad, Marianne; Ellhammer,Olle

    2004-01-01

    This study examined 2 samples of adolescents and mothers using a child-based design (Nonshared Environment in Adolescent Development [NEAD] project, N = 395 families) and a parent-based design (Twin Moms [TM] project, N = 236 twin family pairs) to compare genetic and environmental influences on mothering. For both samples, the same measures of…

  17. Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Improved understanding of the combined effects of geology, ecology and human intervention is essential for efficient conservation and use of plant germplasm. In the pr...

  18. Genetic and Environmental Influences on Girls' and Boys' Gender-Typed and Gender-Neutral Values

    ERIC Educational Resources Information Center

    Knafo, Ariel; Spinath, Frank M.

    2011-01-01

    In this first investigation of genetic and environmental influences on children's values, 271 German twin pairs (50.2% boys) reported their values at ages 7-11 years using the Portrait Values Questionnaire (Schwartz & Rubel, 2005). We distinguished between gender-neutral (conservation vs. openness to change) and gender-typed (self-transcendence…

  19. Influence of genetic background on anthocyanin and copigment composition and behavior during thermoalkaline processing of maize

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Visual color is a primary factor for foods purchase; identifying factors that influence in-situ color quality of pigmented maize during processing is important. We used 24 genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) to investigate the effect of pigment and copigme...

  20. 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

  1. 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

  2. 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

  3. 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

  4. Genetics/genomics advances to influence care for patients with chronic disease.

    PubMed

    Beery, Theresa Alice; Smith, Carolyn R

    2011-01-01

    Rapid changes in the field of genetics/genomics are affecting the way we practice nursing. Staying current on this dynamic field is a challenge for all healthcare professionals. This article discusses genetics/genomics issues that are likely to have a strong influence on nurses who care for patients with chronic disease. Complex diseases involving the actions of genes and environment are the most common causes of morbidity and mortality. Pharmacogenetics/pharmacogenomics has the potential to alter the way we choose both medications and appropriate doses. Nutrigenomics promises to help us understand how diet affects gene expression and how genetic variants affect the way we use nutrients. Genetic testing can be purchased through the Internet and currently is being marketed directly to consumers. Each of these topics has present and future implications for all healthcare professionals, especially those caring for people with chronic disease. PMID:21473561

  5. 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

  6. Identical genetic influences underpin behavior problems in adolescence and basic traits of personality

    PubMed Central

    Lewis, Gary J; Haworth, Claire M A; Plomin, Robert

    2014-01-01

    Background Understanding the etiology of adolescent problem behavior has been of enduring interest. Only relatively recently, however, has this issue been examined within a normal personality trait framework. Research suggests that problem behaviors in adolescence and beyond may be adequately explained by the taxonomy provided by the basic dimensions of normal personality: Such problem behaviors are suggested to be extreme points on a distribution of the full range of the underlying traits. We extend work in this field examining the extent to which genetic factors underlying the five-factor model of personality are common with genetic influences on adolescent behavior problems (namely, anxiety, peer problems, conduct, hyperactivity, and low prosociality). Method A nationally representative twin sample (Twins Early Development Study) from the general population of England and Wales, including 2031 pairs of twins aged 16 years old, was used to decompose variation into genetic and environmental components. Behavioral problems in adolescence were assessed by self-report with the Strengths and Difficulties Questionnaire. Results Adolescent behavior problems were moderately associated with normal personality: Specifically, a fifth to a third of phenotypic variance in problem behaviors was accounted for by five-factor model personality traits. Of central importance here, genetic influences underpinning personality were entirely overlapping with those genetic factors underlying adolescent behavior problems. Conclusions These findings suggest that adolescent behavior problems can be understood, at least in part, within a model of normal personality trait variation, with the genetic bases of these behavior problems the same as those genetic influences underpinning normal personality. Read the Commentary for this article on doi: 10.1111/jcpp.12292 PMID:24256444

  7. Genetic factors influence level of proteinuria in cationic antigen-induced immune complex glomerulonephritis in the rat.

    PubMed Central

    Kato, A; Thaiss, F; Oite, T; Günther, E; Batsford, S; Vogt, A

    1985-01-01

    The influence of genetic factors on the susceptibility of the rat to cationic antigen-induced in situ immune complex glomerulonephritis was investigated. The levels of proteinuria developing in 11 inbred strains of rats differing in MHC and in genetic background varied markedly. Susceptibility was not MHC associated but resided in the genetic background. PMID:3159528

  8. 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

  9. Comparative multilocus phylogeography of two Palaearctic spruce bark beetles: influence of contrasting ecological strategies on genetic variation.

    PubMed

    Mayer, François; Piel, Frédéric B; Cassel-Lundhagen, Anna; Kirichenko, Natalia; Grumiau, Laurent; Økland, Bjørn; Bertheau, Coralie; Grégoire, Jean-Claude; Mardulyn, Patrick

    2015-03-01

    While phylogeographic patterns of organisms are often interpreted through past environmental disturbances, mediated by climate changes, and geographic barriers, they may also be strongly influenced by species-specific traits. To investigate the impact of such traits, we focused on two Eurasian spruce bark beetles that share a similar geographic distribution, but differ in their ecology and reproduction. Ips typographus is an aggressive tree-killing species characterized by strong dispersal, whereas Dendroctonus micans is a discrete inbreeding species (sib mating is the rule), parasite of living trees and a poor disperser. We compared genetic variation between the two species over both beetles' entire range in Eurasia with five independent gene fragments, to evaluate whether their intrinsic differences could have an influence over their phylogeographic patterns. We highlighted widely divergent patterns of genetic variation for the two species and argue that the difference is indeed largely compatible with their contrasting dispersal strategies and modes of reproduction. In addition, genetic structure in I. typographus divides European populations in a northern and a southern group, as was previously observed for its host plant, and suggests past allopatric divergence. A long divergence time was estimated between East Asian and other populations of both species, indicating their long-standing presence in Eurasia, prior to the last glacial maximum. Finally, the strong population structure observed in D. micans for the mitochondrial locus provides insights into the recent colonization history of this species, from its native European range to regions where it was recently introduced. PMID:25655781

  10. 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 ...

  11. 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 ...

  12. Genetic and Environmental Influences on the Allocation of Adolescent Leisure Time Activities

    PubMed Central

    Haberstick, Brett C.; Zeiger, Joanna S.; Corley, Robin P.

    2014-01-01

    There is a growing recognition of the importance of the out-of-school activities in which adolescents choose to participate. Youth activities vary widely in terms of specific activities and in time devoted to them but can generally be grouped by the type and total duration spent per type. We collected leisure time information using a 17-item leisure time questionnaire in a large sample of same- and opposite-sex adolescent twin pairs (N = 2847). Using both univariate and multivariate genetic models, we sought to determine the type and magnitude of genetic and environmental influences on the allocation of time toward different leisure times. Results indicated that both genetic and shared and nonshared environmental influences were important contributors to individual differences in physical, social, intellectual, family, and passive activities such as watching television. The magnitude of these influences differed between males and females. Environmental influences were the primary factors contributing to the covariation of different leisure time activities. Our results suggest the importance of heritable influences on the allocation of leisure time activity by adolescents and highlight the importance of environmental experiences in these choices. PMID:24967407

  13. 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

  14. 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

  15. Common genetic variants in NEFL influence gene expression and neuroblastoma risk

    PubMed Central

    Capasso, Mario; Diskin, Sharon; Cimmino, Flora; Acierno, Giovanni; Totaro, Francesca; Petrosino, Giuseppe; Pezone, Lucia; Diamond, Maura; McDaniel, Lee; Hakonarson, Hakon; Iolascon, Achille; Devoto, Marcella; Maris, John M

    2014-01-01

    The genetic etiology of sporadic neuroblastoma is still largely obscure. In a genome-wide association study, we identified single nucleotide polymorphisms (SNP) associated with neuroblastoma at the LINC00340, BARD1, LMO1, DUSP12, HSD17B12, HACE1 and LIN28B gene loci, but these explain only a small fraction of neuroblastoma heritability. Other neuroblastoma susceptibility genes are likely hidden among signals discarded by the multiple testing corrections. In this study, we evaluated 8 additional genes selected as candidates for further study based on proven involvement in neuroblastoma differentiation. SNP at these candidate genes were tested for association with disease susceptibility in 2101 cases and 4202 controls, with the associations found replicated in an independent cohort of 459 cases and 809 controls. Replicated associations were further studied for cis-effect using gene expression, transient overexpression, silencing and cellular differentiation assays. The neurofilament gene NEFL harbored three SNP associated with neuroblastoma (rs11994014; Pcombined=0.0050; OR=0.88, rs2979704; Pcombined=0.0072; OR=0.87, rs105911; Pcombined=0.0049; OR=0.86). The protective allele of rs1059111 correlated with increased NEFL expression. Biological investigations showed that ectopic overexpression of NEFL inhibited cell growth specifically in neuroblastoma cells carrying the protective allele. NEFL overexpression also enhanced differentiation and impaired the proliferation and anchorage-independent growth of cells with protective allele and basal NEFL expression, while impairing invasiveness and proliferation of cells homozygous for the risk genotype. Clinically, high levels of NEFL expression in primary neuroblastoma specimens was associated with better overall survival (P=0.03; HR=0.68). Our results show that common variants of NEFL influence neuroblastoma susceptibility and they establish that NEFL expression influences disease initiation and progression. PMID:25312269

  16. Genetic and Environmental Influences on Frontal EEG Asymmetry and Alpha Power in 9–10 Year Old Twins

    PubMed Central

    Gao, Yu; Tuvblad, Catherine; Raine, Adrian; Lozano, Dora I.; Baker, Laura A.

    2008-01-01

    Modest genetic influences on frontal EEG asymmetry have been found in adults, but little is known about its genetic origins in children. Resting frontal asymmetry and alpha power were examined in 951 9–10-year-old twins. Results showed that in both males and females: (1) a modest but significant amount of variance in frontal asymmetry was accounted for by genetic factors (11–27%) with the remainder accounted for by non-shared environmental influences, and (2) alpha power were highly heritable, with 70–85% of the variance accounted for by genetic factors. Results suggest that the genetic architecture of frontal asymmetry and alpha power in late childhood are similar to that in adulthood and that the high non-shared environmental influences on frontal asymmetry may reflect environmentally-influenced individual differences in the maturation of frontal cortex as well as state-dependent influences on specific measurements. PMID:19386046

  17. Influence of wastewater disinfection on densities of culturable fecal indicator bacteria and genetic markers.

    PubMed

    Chern, Eunice C; Brenner, Kristen; Wymer, Larry; Haugland, Richard A

    2014-09-01

    The US Environmental Protection Agency has proposed the use of quantitative polymerase chain reaction (qPCR) as a rapid alternative analytical method for monitoring recreational water quality at beaches. For qPCR to be considered for other Clean Water Act purposes, such as inclusion in discharge permits and use in Total Maximum Daily Load calculations, it is necessary to understand how qPCR detectable genetic markers are influenced by wastewater disinfection. This study investigated genetic markers for Escherichia coli, Enterococcus, Clostridium spp., Bacteroides, total Bacteroidales, as well as the human-associated Bacteroides markers, HF183 and HumM2, to determine which, if any, were influenced by disinfection (chlorination or ultraviolet light) of effluents from secondary wastewater treatment in different seasons. The effects of disinfection on culturable enterococci, E. coli, Bacteroides, and C. perfringens were also compared to their associated genetic markers. Disinfection of secondary treatment effluents significantly reduced culturable fecal indicator bacteria (FIB) but not genetic marker densities. No significant differences were observed in the responses of FIB culture and genetic marker densities to type of disinfection (chlorination vs UV) or season. Results of this study provide evidence that qPCR may not be suitable for monitoring efficacy of wastewater disinfection on the inactivation of bacterial pathogens. PMID:25252344

  18. Sertraline for the Treatment of Depression in Alzheimer Disease: Genetic Influences

    PubMed Central

    Peters, Matthew E.; Vaidya, Vijay; Drye, Lea T.; Rosenberg, Paul B.; Martin, Barbara K.; Porsteinsson, Anton P.; Frangakis, Constantine E.; Mintzer, Jacobo; Weintraub, Daniel; Schneider, Lon S.; Rabins, Peter V.; Munro, Cynthia A.; Meinert, Curtis L.; Lyketsos, Constantine G.; Dimitri, Avramopoulos

    2012-01-01

    Objective To assess the potential for genetic influences on sertraline treatment efficacy for depression of Alzheimer disease (dAD). Four functional genetic variants were studied: 2 serotonin receptors (HTR2A-T102C and HTR2C-Cys23Ser), the serotonin transporter (5HTT-LPR), and brain-derived neurotrophic factor (BDNF-Val66Met). Treatment response by genotype was measured by (1) the modified Alzheimer’s Disease Cooperative Study Clinical Global Impression of Change, (2) the Cornell scale for Depression in Dementia, and (3) remission of depression. Methods We utilized data from the Depression in Alzheimer’s Disease Study 2 (DIADS-2), a 24-week, randomized, multicenter trial showing no significant treatment effect of sertraline on dAD. Proportional odds logistic regression and mixed effects models were used to examine the above mentioned outcome measures. Results No significant interactions were seen between any of the genetic polymorphisms and the selected outcomes above at 12 or 24 weeks. Discussion Treatment outcomes in the DIADS-2 trial were not significantly influenced by genetic variation at the loci that were assessed. Future studies should continue to examine the interaction of depression-related genetic variants with antidepressant treatment in Alzheimer disease patients with depression. PMID:22228829

  19. What monozygotic twins discordant for phenotype illustrate about mechanisms influencing genetic forms of neurodegeneration.

    PubMed

    Ketelaar, M E; Hofstra, E M W; Hayden, M R

    2012-04-01

    As monozygotic (MZ) twins are believed to be genetically identical, discordance for disease phenotype between MZ twins has been used in genetic research to understand the contribution of genetic vs environmental factors in disease development. However, recent studies show that MZ twins can differ both genetically and epigenetically. Screening MZ twins for genetic and/or epigenetic differences could be a useful and novel approach to identify modifying factors influencing phenotypic expression of disease. MZ twins that are phenotypically discordant for monogenic diseases are of special interest. Such occurrences have been described for Huntington's disease, spinocerebellar ataxias, as well as for familial forms of Alzheimer's disease. By comparing MZ twins that are phenotypically discordant, crucial factors influencing the phenotypic expression of the disease could be identified, which may be of relevance for understanding disease pathogenesis and variability in disease phenotype. Overall, understanding the crucial factors in development of a neurodegenerative disorder will have relevance for predictive testing, preventive treatment and could help to identify novel therapeutic targets. PMID:21981075

  20. Different Slopes for Different Folks: Genetic Influences on Growth in Delinquent Peer Association and Delinquency During Adolescence.

    PubMed

    Connolly, Eric J; Schwartz, Joseph A; Nedelec, Joseph L; Beaver, Kevin M; Barnes, J C

    2015-07-01

    An extensive line of research has identified delinquent peer association as a salient environmental risk factor for delinquency, especially during adolescence. While previous research has found moderate-to-strong associations between exposure to delinquent peers and a variety of delinquent behaviors, comparatively less scholarship has focused on the genetic architecture of this association over the course of adolescence. Using a subsample of kinship pairs (N = 2379; 52% female) from the National Longitudinal Survey of Youth-Child and Young Adult Supplement (CNLSY), the present study examined the extent to which correlated individual differences in starting levels and developmental growth in delinquent peer pressure and self-reported delinquency were explained by additive genetic and environmental influences. Results from a series of biometric growth models revealed that 37% of the variance in correlated growth between delinquent peer pressure and self-reported delinquency was explained by additive genetic effects, while nonshared environmental effects accounted for the remaining 63% of the variance. Implications of these findings for interpreting the nexus between peer effects and adolescent delinquency are discussed. PMID:25967897

  1. Do sleep disturbances and psychotic-like experiences in adolescence share genetic and environmental influences?

    PubMed

    Taylor, Mark J; Gregory, Alice M; Freeman, Daniel; Ronald, Angelica

    2015-08-01

    Sleep disturbances regularly co-occur with clinical psychotic disorders and dimensions of psychotic-like experiences (PLEs). One possible explanation for this, which has yet to be tested, is that similar genetic or environmental influences underlie sleep disturbances and vulnerability to PLEs. We conducted a twin study to test this possibility in relation to sleep disturbances and six specific PLEs in adolescence in the general population. Approximately 5,000 16-year-old twin pairs completed the Pittsburgh Sleep Quality Index and Insomnia Severity Index. PLEs were assessed using the Specific PLEs Questionnaire, comprising five self-report subscales (Paranoia, Hallucinations, Cognitive Disorganization, Grandiosity, and Anhedonia) and one parent-report subscale (Negative Symptoms). The associations between these measures were tested using structural equation twin model fitting. Paranoia, Hallucinations, and Cognitive Disorganization displayed moderate and significant correlations with both sleep measures (0.32-.42), while Negative Symptoms, Anhedonia, and Grandiosity showed lower correlations (0.01-0.17). Genetic and environmental influences significantly overlapped across PLEs (Paranoia, Hallucinations, Cognitive Disorganization) and both types of sleep disturbance (mean genetic and nonshared environmental correlations = 0.54 and 0.24, respectively). These estimates reduced, yet remained significant, after controlling for negative affect. The association between PLEs with sleep disturbances in adolescence is partly due to genetic and environmental influences that are common to them both. These findings indicate that the known neurobiology of sleep disturbance may provide clues regarding the causes of PLEs in adolescence. PMID:25938536

  2. Do Sleep Disturbances and Psychotic-Like Experiences in Adolescence Share Genetic and Environmental Influences?

    PubMed Central

    2015-01-01

    Sleep disturbances regularly co-occur with clinical psychotic disorders and dimensions of psychotic-like experiences (PLEs). One possible explanation for this, which has yet to be tested, is that similar genetic or environmental influences underlie sleep disturbances and vulnerability to PLEs. We conducted a twin study to test this possibility in relation to sleep disturbances and six specific PLEs in adolescence in the general population. Approximately 5,000 16-year-old twin pairs completed the Pittsburgh Sleep Quality Index and Insomnia Severity Index. PLEs were assessed using the Specific PLEs Questionnaire, comprising five self-report subscales (Paranoia, Hallucinations, Cognitive Disorganization, Grandiosity, and Anhedonia) and one parent-report subscale (Negative Symptoms). The associations between these measures were tested using structural equation twin model fitting. Paranoia, Hallucinations, and Cognitive Disorganization displayed moderate and significant correlations with both sleep measures (0.32–.42), while Negative Symptoms, Anhedonia, and Grandiosity showed lower correlations (0.01–0.17). Genetic and environmental influences significantly overlapped across PLEs (Paranoia, Hallucinations, Cognitive Disorganization) and both types of sleep disturbance (mean genetic and nonshared environmental correlations = 0.54 and 0.24, respectively). These estimates reduced, yet remained significant, after controlling for negative affect. The association between PLEs with sleep disturbances in adolescence is partly due to genetic and environmental influences that are common to them both. These findings indicate that the known neurobiology of sleep disturbance may provide clues regarding the causes of PLEs in adolescence. PMID:25938536

  3. Additive-Driven Assembly of Block Copolymer and Nanoparticles: Influence of Nanoparticle Size and Loading

    NASA Astrophysics Data System (ADS)

    Gai, Yue; Lin, Ying; Watkins, James

    2015-03-01

    Additive-driven assembly of block copolymer (BCP)/nanoparticle (NP) composites in which functionalized NPs exhibiting strong hydrogen bond interactions with one domain of the BCP has been shown to strengthen phase segregation and yield well-ordered materials at high NP loadings. Here we report a systemic study of how phase behavior and NP distribution in BCP/ Au NP composites are influenced by the NP size, NP loading and block copolymer domain size. 2nm, 5nm, 9nm and 15nm diameter Au nanoparticles at loadings ranging from 10% to 50% weight percent, in polystyrene-block-poly (2-vinyl pyridine) block copolymers with domain spacing ranging from 14 nm to 75 nm were used in the investigation. We find that strong interactions enable the incorporation of larger diameter NPs with respect to domain size as compared to systems in which interactions between the NP and BCP are weak or enthalpically neutral. This work was supported by NSF Center for Hierarchical Manufacturing at the University of Massachusetts, Amherst.

  4. Influence of Alumina Additions on the Physical and Chemical Properties of Lithium-iron-phosphate Glasses

    NASA Astrophysics Data System (ADS)

    Liu, Huali; Yang, Ruijuan; Wang, Yinghui; Liu, Shiquan

    Alumina improves the properties and depresses the devitrification of soda-lime-silicate glasses. Herein, the influence of alumina on the glass transition temperature, density, chemical durability, crystallization of lithium-iron-phosphate (LIP) glass has been investigated. As alumina was added to replace the iron oxide in a base LIP glass with the molar composition of Li2O:Fe2O3:P2O5=30:20:50, the alumina-containing glasses have increased Tg, densities and chemical stabilities than the base glass. When the amount of alumina is increased from 2 to 6 mol, the Tg value slightly increases, whereas the density decreases. However, the smallest weight loss is shown for the glass containing 3.2 mol of alumina. The variations of the properties with alumina are explained based on the infrared structure analysis results. In addition, it is found the either the base or the alumina-containing glasses have surface crystallization upon heat-treatments. Under the same treatment conditions, the base glass exhibits a thin layer of crystallization with LiFeP2O7 as the main phase. In contrast, alumina-containing glasses show much higher degree of crystallization, which is further increased with the amount of alumina. This trend is opposite to that of silicate glass. Besides the LiFeP2O7 main phase, Fe7(PO4) phase is also identified in the crystallized alumina-containing glasses.

  5. Aitchbone hanging and ageing period are additive factors influencing pork eating quality.

    PubMed

    Channon, H A; Taverner, M R; D'Souza, D N; Warner, R D

    2014-01-01

    The effects of abattoir, carcase weight (60 or 80 kg HCW), hanging method (Achilles or aitchbone) and ageing period (2 or 7 day post-slaughter) on eating quality attributes of pork were investigated in this 3×2×2×2 factorial study. A total of 144 Large White×Landrace female pigs were slaughtered at one of three abattoirs and sides hung from either the Achilles tendon or the aitchbone. After 24 h chilling, loin (M. longissimus thoracis et lumborum) and topside (M. semimembranosus) muscles were individually vacuum packaged and aged for 2 or 7 days post-slaughter. Consumers (n=852) evaluated eating quality. Neither abattoir nor carcase weight influenced tenderness, flavour or overall liking of pork. Improvements in tenderness, flavour and overall liking were found due to aitchbone hanging (P<0.001) and ageing (P<0.001) for 7 days compared with Achilles-hung carcases and pork aged for 2 days, respectively. This study demonstrated that aitchbone hanging and 7 day ageing can improve eating quality, but these effects were additive as the interaction term was not significant. PMID:24013699

  6. 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

  7. 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.

  8. Genetic determinants in head and neck squamous cell carcinoma and their influence on global personalized medicine

    PubMed Central

    Michmerhuizen, Nicole L.; Birkeland, Andrew C.; Bradford, Carol R.; Brenner, J. Chad

    2016-01-01

    While sequencing studies have provided an improved understanding of the genetic landscape of head and neck squamous cell carcinomas (HNSCC), there remains a significant lack of genetic data derived from non-Caucasian cohorts. Additionally, there is wide variation in HNSCC incidence and mortality worldwide both between and within various geographic regions. These epidemiologic differences are in part accounted for by varying exposure to environmental risk factors such as tobacco, alcohol, high risk human papilloma viruses and betel quid. However, inherent genetic factors may also play an important role in this variability. As limited sequencing data is available for many populations, the involvement of unique genetic factors in HNSCC pathogenesis from epidemiologically diverse groups is unknown. Here, we review current knowledge about the epidemiologic, environmental, and genetic variation in HNSCC cohorts globally and discuss future studies necessary to further our understanding of these differences. Long-term, a more complete understanding of the genetic drivers found in diverse HNSCC cohorts may help the development of personalized medicine protocols for patients with rare or complex genetic events. PMID:27551333

  9. Genetic determinants in head and neck squamous cell carcinoma and their influence on global personalized medicine.

    PubMed

    Michmerhuizen, Nicole L; Birkeland, Andrew C; Bradford, Carol R; Brenner, J Chad

    2016-05-01

    While sequencing studies have provided an improved understanding of the genetic landscape of head and neck squamous cell carcinomas (HNSCC), there remains a significant lack of genetic data derived from non-Caucasian cohorts. Additionally, there is wide variation in HNSCC incidence and mortality worldwide both between and within various geographic regions. These epidemiologic differences are in part accounted for by varying exposure to environmental risk factors such as tobacco, alcohol, high risk human papilloma viruses and betel quid. However, inherent genetic factors may also play an important role in this variability. As limited sequencing data is available for many populations, the involvement of unique genetic factors in HNSCC pathogenesis from epidemiologically diverse groups is unknown. Here, we review current knowledge about the epidemiologic, environmental, and genetic variation in HNSCC cohorts globally and discuss future studies necessary to further our understanding of these differences. Long-term, a more complete understanding of the genetic drivers found in diverse HNSCC cohorts may help the development of personalized medicine protocols for patients with rare or complex genetic events. PMID:27551333

  10. Genetic Influences on Resting-state Functional Networks: A Twin Study

    PubMed Central

    Fu, Yixiao; Ma, Zhiwei; Hamilton, Christina; Liang, Zhifeng; Hou, Xiao; Ma, Xingshun; Hu, Xiaomei; He, Qian; Deng, Wei; Wang, Yingcheng; Zhao, Liansheng; Meng, Huaqing; Li, Tao; Zhang, Nanyin

    2015-01-01

    Alterations in resting-state networks (RSNs) are often associated with psychiatric and neurologic disorders. Given this critical linkage, it has been hypothesized that RSNs can potentially be used as endophenotypes for brain diseases. To validate this notion, a critical step is to show that RSNs exhibit heritability. However, the investigation of the genetic basis of RSNs has only been attempted in the default-mode network at the region-of-interest level, while the genetic control on other RSNs has not been determined yet. Here we examined the genetic and environmental influences on eight well-characterized RSNs by using a twin design. Resting-state functional magnetic resonance imaging data in 56 pairs of twins were collected. The genetic and environmental effects on each RSN were estimated by fitting the functional connectivity covariance of each voxel in the RSN to the classic ACE twin model. The data showed that although environmental effects accounted for the majority of variance in widespread areas, there were specific brain sites that showed significant genetic control for individual RSNs. These results suggest that part of the human brain functional connectome is shaped by genomic constraints. Importantly, this information can be useful for bridging genetic analysis and network-level assessment of brain disorders. PMID:26147340

  11. 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

  12. A study of changes in genetic and environmental influences on weight and shape concern across adolescence.

    PubMed

    Wade, Tracey D; Hansell, Narelle K; Crosby, Ross D; Bryant-Waugh, Rachel; Treasure, Janet; Nixon, Reginald; Byrne, Susan; Martin, Nicholas G

    2013-02-01

    The goal of the current study was to examine whether genetic and environmental influences on an important risk factor for disordered eating, weight and shape concern, remained stable over adolescence. This stability was assessed in 2 ways: whether new sources of latent variance were introduced over development and whether the magnitude of variance contributing to the risk factor changed. We examined an 8-item WSC subscale derived from the Eating Disorder Examination (EDE) using telephone interviews with female adolescents. From 3 waves of data collected from female-female same-sex twin pairs from the Australian Twin Registry, a subset of the data (which included 351 pairs at Wave 1) was used to examine 3 age cohorts: 12 to 13, 13 to 15, and 14 to 16 years. The best-fitting model contained genetic and environmental influences, both shared and nonshared. Biometric model fitting indicated that nonshared environmental influences were largely specific to each age cohort, and results suggested that latent shared environmental and genetic influences that were influential at 12 to 13 years continued to contribute to subsequent age cohorts, with independent sources of both emerging at ages 13 to 15. The magnitude of all 3 latent influences could be constrained to be the same across adolescence. Ages 13 to 15 were indicated as a time of risk for the development of high levels of WSC, given that most specific environmental risk factors were significant at this time (e.g., peer teasing about weight, adverse life events), and indications of the emergence of new sources of latent genetic and environmental variance over this period. PMID:23067261

  13. Overlapping Genetic and Child-Specific Nonshared Environmental Influences on Listening Comprehension, Reading Motivation, and Reading Comprehension

    PubMed Central

    Schenker, Victoria J.; Petrill, Stephen A.

    2015-01-01

    This study investigated the genetic and environmental influences on observed associations between listening comprehension, reading motivation, and reading comprehension. Univariate and multivariate quantitative genetic models were conducted in a sample of 284 pairs of twins at a mean age of 9.81 years. Genetic and nonshared environmental factors accounted for statistically significant variance in listening and reading comprehension, and nonshared environmental factors accounted for variance in reading motivation. Furthermore, listening comprehension demonstrated unique genetic and nonshared environmental influences but also had overlapping genetic influences with reading comprehension. Reading motivation and reading comprehension each had unique and overlapping nonshared environmental contributions. Therefore, listening comprehension appears to be related to reading primarily due to genetic factors whereas motivation appears to affect reading via child-specific, nonshared environmental effects. PMID:26321677

  14. The Relationship Between the Genetic and Environmental Influences on Common Internalizing Psychiatric Disorders and Mental Well-Being

    PubMed Central

    Myers, John M.; Maes, Hermine H.; Keyes, Corey L. M.

    2011-01-01

    To determine the relationship between the genetic and environmental risk factors for common internalizing psychopathology (IP) and mental well-being (MWB), we examined detailed measures of emotional, social and psychological well-being, and a history of major depression (MD), generalized anxiety disorder (GAD) and panic attacks in the last year, in 1,386 twins from same-sex pairs from the MIDUS national USA sample assessed in 1995 and then again in 2005. Statistical analyses were performed with the Mx program. In the 1995 data, the best fit model contained one substantially heritable common factor for MD, GAD and panic attacks, and one strongly heritable common factor for the three well-being measures. Genetic and environmental risk factors for IP accounted for, respectively, 50 and 5%, of the genetic and environmental influences on MWB. We then constructed, using 1995 and 2005 data, two common factors that reflected temporally stable influences on (i) MD and GAD, and (ii) on emotional and psychological well-being. Genetic and environmental risk factors for the stable liability to IP accounted for 41 and 29% of the stable genetic and environmental influences, respectively, on MWB. This study suggests that genetic risk factors for IP make up 41–50% of the genetic influences on MWB. The overlap of environmental risk factors is more modest. Although low levels of IP on average reflect a high genetic propensity for MWB, other independent genetic influences play an important role in producing good mental health. PMID:21451959

  15. Influence of Al/CuO reactive multilayer films additives on exploding foil initiator

    NASA Astrophysics Data System (ADS)

    Zhou, Xiang; Shen, Ruiqi; Ye, Yinghua; Zhu, Peng; Hu, Yan; Wu, Lizhi

    2011-11-01

    An investigation on the influence of Al/CuO reactive multilayer films (RMFs) additives on exploding foil initiator was performed in this paper. Cu film and Cu/Al/CuO RMFs were produced by using standard microsystem technology and RF magnetron sputtering technology, respectively. Scanning electron microscopy characterization revealed the distinct layer structure of the as-deposited Al/CuO RMFs. Differential scanning calorimetry was employed to ascertain the amount of heat released in the thermite reaction between Al films and CuO films, which was found to be 2024 J/g. Electrical explosion tests showed that 600 V was the most matching voltage for our set of apparatus. The explosion process of two types of films was observed by high speed camera and revealed that compared with Cu film, an extra distinct combustion phenomenon was detected with large numbers of product particles fiercely ejected to a distance of about six millimeters for Cu/Al/CuO RMFs. By using the atomic emission spectroscopy double line technique, the reaction temperature was determined to be about 6000-7000 K and 8000-9000 K for Cu film and Cu/Al/CuO RMFs, respectively. The piezoelectricity of polyvinylidene fluoride film was employed to measure the average velocity of the slapper accelerated by the explosion of the films. The average velocities of the slappers were calculated to be 381 m/s and 326 m/s for Cu film and Cu/Al/CuO RMFs, respectively, and some probable reasons were discussed with a few suggestions put forward for further work.

  16. Pubertal Onset in Girls is Strongly Influenced by Genetic Variation Affecting FSH Action

    PubMed Central

    Hagen, Casper P.; Sørensen, Kaspar; Aksglaede, Lise; Mouritsen, Annette; Mieritz, Mikkel G.; Tinggaard, Jeanette; Wohlfart-Veje, Christine; Petersen, Jørgen Holm; Main, Katharina M.; Meyts, Ewa Rajpert-De; Almstrup, Kristian; Juul, Anders

    2014-01-01

    Age at pubertal onset varies substantially in healthy girls. Although genetic factors are responsible for more than half of the phenotypic variation, only a small part has been attributed to specific genetic polymorphisms identified so far. Follicle-stimulating hormone (FSH) stimulates ovarian follicle maturation and estradiol synthesis which is responsible for breast development. We assessed the effect of three polymorphisms influencing FSH action on age at breast deveopment in a population-based cohort of 964 healthy girls. Girls homozygous for FSHR -29AA (reduced FSH receptor expression) entered puberty 7.4 (2.5–12.4) months later than carriers of the common variants FSHR -29GG+GA, p = 0.003. To our knowledge, this is the strongest genetic effect on age at pubertal onset in girls published to date. PMID:25231187

  17. Genetic influences can protect against unresponsive parenting in the prediction of child social competence.

    PubMed

    Van Ryzin, Mark J; Leve, Leslie D; Neiderhiser, Jenae M; Shaw, Daniel S; Natsuaki, Misaki N; Reiss, David

    2015-01-01

    Although social competence in children has been linked to the quality of parenting, prior research has typically not accounted for genetic similarities between parents and children, or for interactions between environmental (i.e., parental) and genetic influences. In this article, the possibility of a Gene x Environment (G × E) interaction in the prediction of social competence in school-age children is evaluated. Using a longitudinal, multimethod data set from a sample of children adopted at birth (N = 361), a significant interaction was found between birth parent sociability and sensitive, responsive adoptive parenting when predicting child social competence at school entry (age 6), even when controlling for potential confounds. An analysis of the interaction revealed that genetic strengths can buffer the effects of unresponsive parenting. PMID:25581124

  18. Cytoplasmic genetic variation and extensive cytonuclear interactions influence natural variation in the metabolome

    PubMed Central

    Joseph, Bindu; Corwin, Jason A; Li, Baohua; Atwell, Suzi; Kliebenstein, Daniel J

    2013-01-01

    Understanding genome to phenotype linkages has been greatly enabled by genomic sequencing. However, most genome analysis is typically confined to the nuclear genome. We conducted a metabolomic QTL analysis on a reciprocal RIL population structured to examine how variation in the organelle genomes affects phenotypic variation. This showed that the cytoplasmic variation had effects similar to, if not larger than, the largest individual nuclear locus. Inclusion of cytoplasmic variation into the genetic model greatly increased the explained phenotypic variation. Cytoplasmic genetic variation was a central hub in the epistatic network controlling the plant metabolome. This epistatic influence manifested such that the cytoplasmic background could alter or hide pairwise epistasis between nuclear loci. Thus, cytoplasmic genetic variation plays a central role in controlling natural variation in metabolomic networks. This suggests that cytoplasmic genomes must be included in any future analysis of natural variation. DOI: http://dx.doi.org/10.7554/eLife.00776.001 PMID:24150750

  19. Summer eczema in exported Icelandic horses: influence of environmental and genetic factors

    PubMed Central

    Björnsdóttir, Sigríður; Sigvaldadóttir, Jakobína; Broström, Hans; Langvad, Birgitte; Sigurðsson, Ágúst

    2006-01-01

    A cross sectional study was designed to estimate the prevalence of summer eczema (a chronic, recurrent seasonal dermatitis) in exported Icelandic horses and the influence of environmental and genetic factors on the development of the disease. Among 330 horses, which had been exported to Germany, Denmark and Sweden, 114 (34.5%) were found to have clinical signs of summer eczema. The prevalence was highest 2 years after export and the exposure to the biting midges Culicoides spp., was found to be the main risk factor for developing the disease. Genetic influence on the sensitivity for the disease was not established. It was concluded that exported Icelandic horses are predisposed for summer dermatitis and the fact that they are not introduced to the antigens of the biting midges early in live, due to it's absence in Iceland, is likely to explain the high prevalence of the disease after export. PMID:16987399

  20. Local environment but not genetic differentiation influences biparental care in ten plover populations.

    PubMed

    Vincze, Orsolya; Székely, Tamás; Küpper, Clemens; Alrashidi, Monif; Amat, Juan A; Ticó, Araceli Argüelles; Burgas, Daniel; Burke, Terry; Cavitt, John; Figuerola, Jordi; Shobrak, Mohammed; Montalvo, Tomas; Kosztolányi, András

    2013-01-01

    Social behaviours are highly variable between species, populations and individuals. However, it is contentious whether behavioural variations are primarily moulded by the environment, caused by genetic differences, or a combination of both. Here we establish that biparental care, a complex social behaviour that involves rearing of young by both parents, differs between closely related populations, and then test two potential sources of variation in parental behaviour between populations: ambient environment and genetic differentiation. We use 2904 hours behavioural data from 10 geographically distinct Kentish (Charadrius alexandrinus) and snowy plover (C. nivosus) populations in America, Europe, the Middle East and North Africa to test these two sources of behavioural variation. We show that local ambient temperature has a significant influence on parental care: with extreme heat (above 40 °C) total incubation (i.e. % of time the male or female incubated the nest) increased, and female share (% female share of incubation) decreased. By contrast, neither genetic differences between populations, nor geographic distances predicted total incubation or female's share of incubation. These results suggest that the local environment has a stronger influence on a social behaviour than genetic differentiation, at least between populations of closely related species. PMID:23613768

  1. Mouse models for studying genetic influences on factors determining smoking cessation success in humans

    PubMed Central

    Hall, F. Scott; Markou, Athina; Levin, Edward D.; Uhl, George R.

    2014-01-01

    Humans differ in their ability to quit using addictive substances, including nicotine, the major psychoactive ingredient in tobacco. For tobacco smoking, a substantial body of evidence, largely derived from twin studies, indicates that approximately half of these individual differences in ability to quit are heritable [1, 2], genetic influences that likely overlap with those for other addictive substances [3]. Both twin and molecular genetic studies support overlapping influences on nicotine addiction vulnerability and smoking cessation success, although there is little formal analysis of the twin data that supports this important point [2, 3]. None of the current datasets provides clear data concerning which heritable factors might provide robust dimensions around which individuals differ in ability to quit smoking. One approach to this problem is to test mice with genetic variations in genes that contain human variants that alter quit-success. This review considers which features of quit success should be included in a comprehensive approach to elucidating the genetics of quit success, and how those features may be modeled in mice. PMID:22304675

  2. Local Environment but Not Genetic Differentiation Influences Biparental Care in Ten Plover Populations

    PubMed Central

    Vincze, Orsolya; Székely, Tamás; Küpper, Clemens; AlRashidi, Monif; Amat, Juan A.; Ticó, Araceli Argüelles; Burgas, Daniel; Burke, Terry; Cavitt, John; Figuerola, Jordi; Shobrak, Mohammed; Montalvo, Tomas; Kosztolányi, András

    2013-01-01

    Social behaviours are highly variable between species, populations and individuals. However, it is contentious whether behavioural variations are primarily moulded by the environment, caused by genetic differences, or a combination of both. Here we establish that biparental care, a complex social behaviour that involves rearing of young by both parents, differs between closely related populations, and then test two potential sources of variation in parental behaviour between populations: ambient environment and genetic differentiation. We use 2904 hours behavioural data from 10 geographically distinct Kentish (Charadrius alexandrinus) and snowy plover (C. nivosus) populations in America, Europe, the Middle East and North Africa to test these two sources of behavioural variation. We show that local ambient temperature has a significant influence on parental care: with extreme heat (above 40°C) total incubation (i.e. % of time the male or female incubated the nest) increased, and female share (% female share of incubation) decreased. By contrast, neither genetic differences between populations, nor geographic distances predicted total incubation or female's share of incubation. These results suggest that the local environment has a stronger influence on a social behaviour than genetic differentiation, at least between populations of closely related species. PMID:23613768

  3. Genetic variants influencing effectiveness of exercise training programmes in obesity – an overview of human studies

    PubMed Central

    Ahmetov, II; Zmijewski, P

    2016-01-01

    Frequent and regular physical activity has significant benefits for health, including improvement of body composition and help in weight control. Consequently, promoting training programmes, particularly in those who are genetically predisposed, is a significant step towards controlling the presently increasing epidemic of obesity. Although the physiological responses of the human body to exercise are quite well described, the genetic background of these reactions still remains mostly unknown. This review not only summarizes the current evidence, through a literature review and the results of our studies on the influence of gene variants on the characteristics and range of the body's adaptive response to training, but also explores research organization problems, future trends, and possibilities. We describe the most reliable candidate genetic markers that are involved in energy balance pathways and body composition changes in response to training programmes, such as FTO, MC4R, ACE, PPARG, LEP, LEPR, ADRB2, and ADRB3. This knowledge can have an enormous impact not only on individualization of exercise programmes to make them more efficient and safer, but also on improved recovery, traumatology, medical care, diet, supplementation and many other areas. Nevertheless, the current studies still represent only the first steps towards a better understanding of the genetic factors that influence obesity-related traits, as well as gene variant x physical activity interactions, so further research is necessary. PMID:27601774

  4. Genetic variation in offspring indirectly influences the quality of maternal behaviour in mice

    PubMed Central

    Ashbrook, David George; Gini, Beatrice; Hager, Reinmar

    2015-01-01

    Conflict over parental investment between parent and offspring is predicted to lead to selection on genes expressed in offspring for traits influencing maternal investment, and on parentally expressed genes affecting offspring behaviour. However, the specific genetic variants that indirectly modify maternal or offspring behaviour remain largely unknown. Using a cross-fostered population of mice, we map maternal behaviour in genetically uniform mothers as a function of genetic variation in offspring and identify loci on offspring chromosomes 5 and 7 that modify maternal behaviour. Conversely, we found that genetic variation among mothers influences offspring development, independent of offspring genotype. Offspring solicitation and maternal behaviour show signs of coadaptation as they are negatively correlated between mothers and their biological offspring, which may be linked to costs of increased solicitation on growth found in our study. Overall, our results show levels of parental provisioning and offspring solicitation are unique to specific genotypes. DOI: http://dx.doi.org/10.7554/eLife.11814.001 PMID:26701914

  5. Genetic variants influencing effectiveness of exercise training programmes in obesity - an overview of human studies.

    PubMed

    Leońska-Duniec, A; Ahmetov, I I; Zmijewski, P

    2016-09-01

    Frequent and regular physical activity has significant benefits for health, including improvement of body composition and help in weight control. Consequently, promoting training programmes, particularly in those who are genetically predisposed, is a significant step towards controlling the presently increasing epidemic of obesity. Although the physiological responses of the human body to exercise are quite well described, the genetic background of these reactions still remains mostly unknown. This review not only summarizes the current evidence, through a literature review and the results of our studies on the influence of gene variants on the characteristics and range of the body's adaptive response to training, but also explores research organization problems, future trends, and possibilities. We describe the most reliable candidate genetic markers that are involved in energy balance pathways and body composition changes in response to training programmes, such as FTO, MC4R, ACE, PPARG, LEP, LEPR, ADRB2, and ADRB3. This knowledge can have an enormous impact not only on individualization of exercise programmes to make them more efficient and safer, but also on improved recovery, traumatology, medical care, diet, supplementation and many other areas. Nevertheless, the current studies still represent only the first steps towards a better understanding of the genetic factors that influence obesity-related traits, as well as gene variant x physical activity interactions, so further research is necessary. PMID:27601774

  6. No Influence of Indy on Lifespan in Drosophila after Correction for Genetic and Cytoplasmic Background Effects

    PubMed Central

    Toivonen, Janne M; Walker, Glenda A; Martinez-Diaz, Pedro; Bjedov, Ivana; Driege, Yasmine; Jacobs, Howard T; Gems, David; Partridge, Linda

    2007-01-01

    To investigate whether alterations in mitochondrial metabolism affect longevity in Drosophila melanogaster, we studied lifespan in various single gene mutants, using inbred and outbred genetic backgrounds. As positive controls we included the two most intensively studied mutants of Indy, which encodes a Drosophila Krebs cycle intermediate transporter. It has been reported that flies heterozygous for these Indy mutations, which lie outside the coding region, show almost a doubling of lifespan. We report that only one of the two mutants lowers mRNA levels, implying that the lifespan extension observed is not attributable to the Indy mutations themselves. Moreover, neither Indy mutation extended lifespan in female flies in any genetic background tested. In the original genetic background, only the Indy mutation associated with altered RNA expression extended lifespan in male flies. However, this effect was abolished by backcrossing into standard outbred genetic backgrounds, and was associated with an unidentified locus on the X chromosome. The original Indy line with long-lived males is infected by the cytoplasmic symbiont Wolbachia, and the longevity of Indy males disappeared after tetracycline clearance of this endosymbiont. These findings underscore the critical importance of standardisation of genetic background and of cytoplasm in genetic studies of lifespan, and show that the lifespan extension previously claimed for Indy mutants was entirely attributable to confounding variation from these two sources. In addition, we saw no effects on lifespan of expression knockdown of the Indy orthologues nac-2 and nac-3 in the nematode Caenorhabditis elegans. PMID:17571923

  7. Ancient Humans Influenced the Current Spatial Genetic Structure of Common Walnut Populations in Asia.

    PubMed

    Pollegioni, Paola; Woeste, Keith E; Chiocchini, Francesca; Del Lungo, Stefano; Olimpieri, Irene; Tortolano, Virginia; Clark, Jo; Hemery, Gabriel E; Mapelli, Sergio; Malvolti, Maria Emilia

    2015-01-01

    Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. It is generally accepted that J. regia survived and grew spontaneously in almost completely isolated stands in its Asian native range after the Last Glacial Maximum. Despite its natural geographic isolation, J. regia evolved over many centuries under the influence of human management and exploitation. We evaluated the hypothesis that the current distribution of natural genetic resources of common walnut in Asia is, at least in part, the product of ancient anthropogenic dispersal, human cultural interactions, and afforestation. Genetic analysis combined with ethno-linguistic and historical data indicated that ancient trade routes such as the Persian Royal Road and Silk Road enabled long-distance dispersal of J. regia from Iran and Trans-Caucasus to Central Asia, and from Western to Eastern China. Ancient commerce also disrupted the local spatial genetic structure of autochthonous walnut populations between Tashkent and Samarkand (Central-Eastern Uzbekistan), where the northern and central routes of the Northern Silk Road converged. A significant association between ancient language phyla and the genetic structure of walnut populations is reported even after adjustment for geographic distances that could have affected both walnut gene flow and human commerce over the centuries. Beyond the economic importance of common walnut, our study delineates an alternative approach for understanding how the genetic resources of long-lived perennial tree species may be affected by the interaction of geography and human history. PMID:26332919

  8. Ancient Humans Influenced the Current Spatial Genetic Structure of Common Walnut Populations in Asia

    PubMed Central

    Pollegioni, Paola; Woeste, Keith E.; Chiocchini, Francesca; Del Lungo, Stefano; Olimpieri, Irene; Tortolano, Virginia; Clark, Jo; Hemery, Gabriel E.; Mapelli, Sergio; Malvolti, Maria Emilia

    2015-01-01

    Common walnut (Juglans regia L) is an economically important species cultivated worldwide for its wood and nuts. It is generally accepted that J. regia survived and grew spontaneously in almost completely isolated stands in its Asian native range after the Last Glacial Maximum. Despite its natural geographic isolation, J. regia evolved over many centuries under the influence of human management and exploitation. We evaluated the hypothesis that the current distribution of natural genetic resources of common walnut in Asia is, at least in part, the product of ancient anthropogenic dispersal, human cultural interactions, and afforestation. Genetic analysis combined with ethno-linguistic and historical data indicated that ancient trade routes such as the Persian Royal Road and Silk Road enabled long-distance dispersal of J. regia from Iran and Trans-Caucasus to Central Asia, and from Western to Eastern China. Ancient commerce also disrupted the local spatial genetic structure of autochthonous walnut populations between Tashkent and Samarkand (Central-Eastern Uzbekistan), where the northern and central routes of the Northern Silk Road converged. A significant association between ancient language phyla and the genetic structure of walnut populations is reported even after adjustment for geographic distances that could have affected both walnut gene flow and human commerce over the centuries. Beyond the economic importance of common walnut, our study delineates an alternative approach for understanding how the genetic resources of long-lived perennial tree species may be affected by the interaction of geography and human history. PMID:26332919

  9. Genetic Influences on Brain Gene Expression in Rats Selected for Tameness and Aggression

    PubMed Central

    Heyne, Henrike O.; Lautenschläger, Susann; Nelson, Ronald; Besnier, François; Rotival, Maxime; Cagan, Alexander; Kozhemyakina, Rimma; Plyusnina, Irina Z.; Trut, Lyudmila; Carlborg, Örjan; Petretto, Enrico; Kruglyak, Leonid; Pääbo, Svante; Schöneberg, Torsten; Albert, Frank W.

    2014-01-01

    Interindividual differences in many behaviors are partly due to genetic differences, but the identification of the genes and variants that influence behavior remains challenging. Here, we studied an F2 intercross of two outbred lines of rats selected for tame and aggressive behavior toward humans for >64 generations. By using a mapping approach that is able to identify genetic loci segregating within the lines, we identified four times more loci influencing tameness and aggression than by an approach that assumes fixation of causative alleles, suggesting that many causative loci were not driven to fixation by the selection. We used RNA sequencing in 150 F2 animals to identify hundreds of loci that influence brain gene expression. Several of these loci colocalize with tameness loci and may reflect the same genetic variants. Through analyses of correlations between allele effects on behavior and gene expression, differential expression between the tame and aggressive rat selection lines, and correlations between gene expression and tameness in F2 animals, we identify the genes Gltscr2, Lgi4, Zfp40, and Slc17a7 as candidate contributors to the strikingly different behavior of the tame and aggressive animals. PMID:25189874

  10. Behavioral and Environmental Modification of the Genetic Influence on Body Mass Index: A Twin Study.

    PubMed

    Horn, Erin E; Turkheimer, Eric; Strachan, Eric; Duncan, Glen E

    2015-07-01

    Body mass index (BMI) has a strong genetic basis, with a heritability around 0.75, but is also influenced by numerous behavioral and environmental factors. Aspects of the built environment (e.g., environmental walkability) are hypothesized to influence obesity by directly affecting BMI, by facilitating or inhibiting behaviors such as physical activity that are related to BMI, or by suppressing genetic tendencies toward higher BMI. The present study investigated relative influences of physical activity and walkability on variance in BMI using 5079 same-sex adult twin pairs (70 % monozygotic, 65 % female). High activity and walkability levels independently suppressed genetic variance in BMI. Estimating their effects simultaneously, however, suggested that the walkability effect was mediated by activity. The suppressive effect of activity on variance in BMI was present even with a tendency for low-BMI individuals to select into environments that require higher activity levels. Overall, our results point to community- or macro-level interventions that facilitate individual-level behaviors as a plausible approach to addressing the obesity epidemic among US adults. PMID:25894925

  11. Behavioral and environmental modification of the genetic influence on body mass index: A twin study

    PubMed Central

    Horn, Erin E.; Turkheimer, Eric; Strachan, Eric; Duncan, Glen E.

    2015-01-01

    Body mass index (BMI) has a strong genetic basis, with a heritability around 0.75, but is also influenced by numerous behavioral and environmental factors. Aspects of the built environment (e.g., environmental walkability) are hypothesized to influence obesity by directly affecting BMI, by facilitating or inhibiting behaviors such as physical activity that are related to BMI, or by suppressing genetic tendencies toward higher BMI. The present study investigated relative influences of physical activity and walkability on variance in BMI using 5,079 same-sex adult twin pairs (70% monozygotic, 65% female). High activity and walkability levels independently suppressed genetic variance in BMI. Estimating their effects simultaneously, however, suggested that the walkability effect was mediated by activity. The suppressive effect of activity on variance in BMI was present even with a tendency for low-BMI individuals to select into environments that require higher activity levels. Overall, our results point to community- or macro-level interventions that facilitate individual-level behaviors as a plausible approach to addressing the obesity epidemic among U.S. adults. PMID:25894925

  12. An application of LOH analysis for detecting the genetic influences of space environmental radiation

    NASA Astrophysics Data System (ADS)

    Yatagai, F.; Umebayashi, Y.; Honma, M.; Abe, T.; Suzuki, H.; Shimazu, T.; Ishioka, N.; Iwaki, M.

    To detect the genetic influence of space environmental radiation at the chromosome level we proposed an application of loss of heterozygosity LOH analysis system for the mutations induced in human lymphoblastoid TK6 cells Surprisingly we succeeded the mutation detection in the frozen dells which were exposed to a low-dose 10 cGy of carbon-ion beam irradiation Mutation assays were performed within a few days or after about one month preservation at --80 r C following irradiation The results showed an increase in mutation frequency at the thymidine kinase TK gene locus 1 6-fold 2 5 X 10 -6 to 3 9 X 10 -6 and 2 1-fold 2 5 X 10 -6 to 5 3 X 10 -6 respectively Although the relative distributions of mutation classes were not changed by the radiation exposure in either assay an interesting characteristic was detected using this LOH analysis system two TK locus markers and eleven microsatellite loci spanning chromosome 17 The radiation-specific patterns of interstitial deletions were observed in the hemizygous LOH mutants which were considered as a result of end-joining repair of carbon ion-induced DNA double-strand breaks These results clearly demonstrate that this analysis can be used for the detection of low-dose ionizing radiation effects in the frozen cells In addition we performed so called adaptive response experiments in which TK6 cells were pre-irradiated with low-dose 2 5 sim 10 cGy of X-ray and then exposed to challenging dose 2Gy of X-rays Interestingly the

  13. The interplay of genetic influences and social processes in developmental theory: specific mechanisms are coming into view.

    PubMed

    Reiss, D; Neiderhiser, J M

    2000-01-01

    In the coming years we can look forward to research that clarifies specific mechanisms that account for the interplay between genetic and environmental influences on psychological development. Certain misconceptions, arising from research traditions initiated by Francis Galton on the one hand and G. Stanley Hall on the other, may now be set aside in the light of new evidence. Three important findings promise a new synthesis. First, while each of us is born with about 100,000 genes that, under ordinary circumstances, do not change, the expression of these genes on behavior is dynamic. Some genetic influences are expressed early in development, but others are manifest many years later. Second, genetic factors often account not only for some of the individual differences in the measures of adjustments we typically use to monitor development but also for individual differences in environmental experiences that covary with those measures of adjustment. Indeed, genetic factors have been found to account for a surprising amount of covariance between measures of the social environment and of adjustment in young children, adolescents, and adults. Third, the expression of genetic influences are very malleable and responsive to the social environment. These new findings are revealing specific mechanisms for the interplay of genetic and social environmental factors in four domains. First, the social environment may play both a necessary and specific role in the expression of particular genetic influences on a range of behaviors from depression to social responsibility. Second, an understanding of the interplay between the social environment and genetics may lead to a clearer definition of the phenotypic manifestations of particular genetic influences. Third, we will-as a result of these studies-have a clearer fix on the timing of important events and their sequence in development. Fourth, this new genre of work promises to illumine more completely mechanisms by which the

  14. Intentional genetic introgression influences survival of adults and subadults in a small, inbred felid population.

    PubMed

    Benson, John F; Hostetler, Jeffrey A; Onorato, David P; Johnson, Warren E; Roelke, Melody E; O'Brien, Stephen J; Jansen, Deborah; Oli, Madan K

    2011-09-01

    1. Inbreeding and low genetic diversity can cause reductions in individual fitness and increase extinction risk in animal populations. Intentional introgression, achieved by releasing genetically diverse individuals into inbred populations, has been used as a conservation tool to improve demographic performance in endangered populations. 2. By the 1980s, Florida panthers (Puma concolor coryi) had been reduced to a small, inbred population that appeared to be on the brink of extinction. In 1995, female pumas from Texas (P. c. stanleyana) were released in occupied panther range as part of an intentional introgression programme to restore genetic variability and improve demographic performance of panthers. 3. We used 25 years (1981-2006) of continuous radiotelemetry and genetic data to estimate and model subadult and adult panther survival and cause-specific mortality to provide rigorous sex and age class-specific survival estimates and evaluate the effect of the introgression programme on these parameters. 4. Genetic ancestry influenced annual survival of subadults and adults after introgression, as F(1) generation admixed panthers ( = 0·98) survived better than pre-introgression type panthers ( = 0·77) and other admixed individuals ( = 0·82). Furthermore, heterozygosity was higher for admixed panthers relative to pre-introgression type panthers and positively influenced survival. 5. Our results are consistent with hybrid vigour; however, extrinsic factors such as low density of males in some areas of panther range may also have contributed to higher survival of F(1) panthers. Regardless, improved survival of F(1) subadults and adults likely contributed to the numerical increase in panthers following introgression, and our results indicate that intentional admixture, achieved here by releasing individuals from another population, appears to have been successful in improving demographic performance in this highly endangered population. PMID:21338353

  15. Anthropogenics: human influence on global and genetic homogenization of parasite populations.

    PubMed

    Zarlenga, Dante S; Hoberg, Eric; Rosenthal, Benjamin; Mattiucci, Simonetta; Nascetti, Giuseppe

    2014-12-01

    The distribution, abundance, and diversity of life on Earth have been greatly shaped by human activities. This includes the geographic expansion of parasites; however, measuring the extent to which humans have influenced the dissemination and population structure of parasites has been challenging. In-depth comparisons among parasite populations extending to landscape-level processes affecting disease emergence have remained elusive. New research methods have enhanced our capacity to discern human impact, where the tools of population genetics and molecular epidemiology have begun to shed light on our historical and ongoing influence. Only since the 1990s have parasitologists coupled morphological diagnosis, long considered the basis of surveillance and biodiversity studies, with state-of-the-art tools enabling variation to be examined among, and within, parasite populations. Prior to this time, populations were characterized only by phenotypic attributes such as virulence, infectivity, host range, and geographical location. The advent of genetic/molecular methodologies (multilocus allozyme electrophoresis, polymerase chain reaction-DNA [PCR-DNA] fragments analysis, DNA sequencing, DNA microsatellites, single nucleotide polymorphisms, etc.) have transformed our abilities to reveal variation among, and within, populations at local, regional, landscape, and global scales, and thereby enhanced our understanding of the biosphere. Numerous factors can affect population structure among parasites, e.g., evolutionary and ecological history, mode of reproduction and transmission, host dispersal, and life-cycle complexity. Although such influences can vary considerably among parasite taxa, anthropogenic factors are demonstrably perturbing parasite fauna. Minimal genetic structure among many geographically distinct (isolated) populations is a hallmark of human activity, hastened by geographic introductions, environmental perturbation, and global warming. Accelerating

  16. Influence of additions of adamantane and its derivatives on electrolytic polishing of Cr18Ni9 stainless steel

    SciTech Connect

    Fedorova, E.A.; Mitrofanov, E.V.; Flerov, V.N.

    1986-02-10

    The authors report the influence of additions of adamantane, hydroxadamantane, bromoadamantane, and acetylaminoadamantane on polishing of Cr18Ni9 alloys in sulfuric-phosphoric acid electrolyte. They show that replacement of adamantane by certain of its derivatives in sulfuric-phosphoric acid solutions for polishing Cr18Ni9 steel increases the technological efficiency of the process considerably; this is due to the greater influence of the new additives on the polarizability of the process and on the surface tension of the solutions.

  17. 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

  18. Influence of ecological and geological features on rangewide patterns of genetic structure in a widespread passerine

    PubMed Central

    Adams, R V; Burg, T M

    2015-01-01

    Geological and ecological features restrict dispersal and gene flow, leading to isolated populations. Dispersal barriers can be obvious physical structures in the landscape; however microgeographic differences can also lead to genetic isolation. Our study examined dispersal barriers at both macro- and micro-geographical scales in the black-capped chickadee, a resident North American songbird. Although birds have high dispersal potential, evidence suggests dispersal is restricted by barriers. The chickadee's range encompasses a number of physiological features which may impede movement and lead to divergence. Analyses of 913 individuals from 34 sampling sites across the entire range using 11 microsatellite loci revealed as many as 13 genetic clusters. Populations in the east were largely panmictic whereas populations in the western portion of the range showed significant genetic structure, which often coincided with large mountain ranges, such as the Cascade and Rocky Mountains, as well as areas of unsuitable habitat. Unlike populations in the central and southern Rockies, populations on either side of the northern Rockies were not genetically distinct. Furthermore, Northeast Oregon represents a forested island within the Great Basin; genetically isolated from all other populations. Substructuring at the microgeographical scale was also evident within the Fraser Plateau of central British Columbia, and in the southeast Rockies where no obvious physical barriers are present, suggesting additional factors may be impeding dispersal and gene flow. Dispersal barriers are therefore not restricted to large physical structures, although mountain ranges and large water bodies do play a large role in structuring populations in this study. PMID:25074576

  19. Influence of ecological and geological features on rangewide patterns of genetic structure in a widespread passerine.

    PubMed

    Adams, R V; Burg, T M

    2015-02-01

    Geological and ecological features restrict dispersal and gene flow, leading to isolated populations. Dispersal barriers can be obvious physical structures in the landscape; however microgeographic differences can also lead to genetic isolation. Our study examined dispersal barriers at both macro- and micro-geographical scales in the black-capped chickadee, a resident North American songbird. Although birds have high dispersal potential, evidence suggests dispersal is restricted by barriers. The chickadee's range encompasses a number of physiological features which may impede movement and lead to divergence. Analyses of 913 individuals from 34 sampling sites across the entire range using 11 microsatellite loci revealed as many as 13 genetic clusters. Populations in the east were largely panmictic whereas populations in the western portion of the range showed significant genetic structure, which often coincided with large mountain ranges, such as the Cascade and Rocky Mountains, as well as areas of unsuitable habitat. Unlike populations in the central and southern Rockies, populations on either side of the northern Rockies were not genetically distinct. Furthermore, Northeast Oregon represents a forested island within the Great Basin; genetically isolated from all other populations. Substructuring at the microgeographical scale was also evident within the Fraser Plateau of central British Columbia, and in the southeast Rockies where no obvious physical barriers are present, suggesting additional factors may be impeding dispersal and gene flow. Dispersal barriers are therefore not restricted to large physical structures, although mountain ranges and large water bodies do play a large role in structuring populations in this study. PMID:25074576

  20. Founding events influence genetic population structure of sockeye salmon (Oncorhynchus nerka) in Lake Clark, Alaska

    USGS Publications Warehouse

    Ramstad, K.M.; Woody, C.A.; Sage, G.K.; Allendorf, F.W.

    2004-01-01

    Bottlenecks can have lasting effects on genetic population structure that obscure patterns of contemporary gene flow and drift. Sockeye salmon are vulnerable to bottleneck effects because they are a highly structured species with excellent colonizing abilities and often occupy geologically young habitats. We describe genetic divergence among and genetic variation within spawning populations of sockeye salmon throughout the Lake Clark area of Alaska. Fin tissue was collected from sockeye salmon representing 15 spawning populations of Lake Clark, Six-mile Lake, and Lake Iliamna. Allele frequencies differed significantly at 11 microsatellite loci in 96 of 105 pairwise population comparisons. Pairwise estimates of FST ranged from zero to 0.089. Six-mile Lake and Lake Clark populations have historically been grouped together for management purposes and are geographically proximate. However, Six-mile Lake populations are genetically similar to Lake Iliamna populations and are divergent from Lake Clark populations. The reduced allelic diversity and strong divergence of Lake Clark populations relative to Six-mile Lake and Lake Iliamna populations suggest a bottleneck associated with the colonization of Lake Clark by sockeye salmon. Geographic distance and spawning habitat differences apparently do not contribute to isolation and divergence among populations. However, temporal isolation based on spawning time and founder effects associated with ongoing glacial retreat and colonization of new spawning habitats contribute to the genetic population structure of Lake Clark sock-eye salmon. Nonequilibrium conditions and the strong influence of genetic drift caution against using estimates of divergence to estimate gene flow among populations of Lake Clark sockeye salmon.

  1. Genetic Influences on Adolescent Sexual Behavior: Why Genes Matter for Environmentally-Oriented Researchers

    PubMed Central

    Harden, K. Paige

    2013-01-01

    There are dramatic individual differences among adolescents in how and when they become sexually active adults, and “early” sexual activity is frequently cited as a cause of concern for scientists, policymakers, and the general public. Understanding the causes and developmental impact of adolescent sexual activity can be furthered by considering genes as a source of individual differences. Quantitative behavioral genetics (i.e., twin and family studies) and candidate gene association studies now provide clear evidence for the genetic underpinnings of individual differences in adolescent sexual behavior and related phenotypes. Genetic influences on sexual behavior may operate through a variety of direct and indirect mechanisms, including pubertal development, testosterone levels, and dopaminergic systems. Genetic differences may be systematically associated with exposure to environments that are commonly treated as causes of sexual behavior (gene-environment correlation). Possible gene-environment correlations pose a serious challenge for interpreting the results of much behavioral research. Multivariate, genetically-informed research on adolescent sexual behavior compares twins and family members as a form of “quasi-experiment”: How do twins who differ in their sexual experiences differ in their later development? The small but growing body of genetically-informed research has already challenged dominant assumptions regarding the etiology and sequelae of adolescent sexual behavior, with some studies indicating possible positive effects of teenage sexuality. Studies of gene × environment interaction may further elucidate the mechanisms by which genes and environments combine to shape the development of sexual behavior and its psychosocial consequences. Overall, the existence of heritable variation in adolescent sexual behavior has profound implications for environmentally-oriented theory and research. PMID:23855958

  2. Natural selection influences AFLP intraspecific genetic variability and introgression patterns in Atlantic eels.

    PubMed

    Gagnaire, P A; Albert, V; Jónsson, B; Bernatchez, L

    2009-04-01

    Investigating patterns of genetic variation in hybridizing species provides an opportunity to understand the impact of natural selection on intraspecific genetic variability and interspecific gene exchange. The Atlantic eels Anguilla rostrata and A. anguilla each occupy a large heterogeneous habitat upon which natural selection could differentially shape genetic variation. They also produce viable hybrids only found in Iceland. However, the possible footprint of natural selection on patterns of genetic variation within species and introgressive hybridization in Icelandic eels has never been assessed. We revisited amplified fragment length polymorphism data collected previously using population genomics and admixture analyses to test if (i) genetic variation could be influenced by non-neutral mechanisms at both the intra- and interspecific levels, and if (ii) selection could shape the spatio-temporal distribution of Icelandic hybrids. We first found candidate loci for directional selection within both species. Spatial distributions of allelic frequencies displayed by some of these loci were possibly related with the geographical patterns of life-history traits in A. rostrata, and could have been shaped by natural selection associated with an environmental gradient along European coasts in A. anguilla. Second, we identified outlier loci at the interspecific level. Non-neutral introgression was strongly suggested for some of these loci. We detected a locus at which typical A. rostrata allele hardly crossed the species genetic barrier, whereas three other loci showed accelerated patterns of introgression into A. anguilla in Iceland. Moreover, the level of introgression at these three loci increased from the glass eel to the yellow eel stage, supporting the hypothesis that differential survival of admixed genotypes partly explains the spatio-temporal pattern of hybrid abundance previously documented in Iceland. PMID:19302349

  3. Influence of Ethnolinguistic Diversity on the Sorghum Genetic Patterns in Subsistence Farming Systems in Eastern Kenya

    PubMed Central

    Labeyrie, Vanesse; Deu, Monique; Barnaud, Adeline; Calatayud, Caroline; Buiron, Marylène; Wambugu, Peterson; Manel, Stéphanie; Glaszmann, Jean-Christophe; Leclerc, Christian

    2014-01-01

    Understanding the effects of actions undertaken by human societies on crop evolution processes is a major challenge for the conservation of genetic resources. This study investigated the mechanisms whereby social boundaries associated with patterns of ethnolinguistic diversity have influenced the on-farm distribution of sorghum diversity. Social boundaries limit the diffusion of planting material, practices and knowledge, thus shaping crop diversity in situ. To assess the effect of social boundaries, this study was conducted in the contact zone between the Chuka, Mbeere and Tharaka ethnolinguistic groups in eastern Kenya. Sorghum varieties were inventoried and samples collected in 130 households. In all, 297 individual plants derived from seeds collected under sixteen variety names were characterized using a set of 18 SSR molecular markers and 15 morphological descriptors. The genetic structure was investigated using both a Bayesian assignment method and distance-based clustering. Principal Coordinates Analysis was used to describe the structure of the morphological diversity of the panicles. The distribution of the varieties and the main genetic clusters across ethnolinguistic groups was described using a non-parametric MANOVA and pairwise Fisher tests. The spatial distribution of landrace names and the overall genetic spatial patterns were significantly correlated with ethnolinguistic partition. However, the genetic structure inferred from molecular makers did not discriminate the short-cycle landraces despite their morphological distinctness. The cases of two improved varieties highlighted possible fates of improved materials. The most recent one was often given the name of local landraces. The second one, that was introduced a dozen years ago, displays traces of admixture with local landraces with differential intensity among ethnic groups. The patterns of congruence or discordance between the nomenclature of farmers’ varieties and the structure of both

  4. Genetic Determinants of On-Aspirin Platelet Reactivity: Focus on the Influence of PEAR1

    PubMed Central

    Würtz, Morten; Nissen, Peter H.; Grove, Erik Lerkevang; Kristensen, Steen Dalby; Hvas, Anne-Mette

    2014-01-01

    Background Platelet aggregation during aspirin treatment displays considerable inter-individual variability. A genetic etiology likely exists, but it remains unclear to what extent genetic polymorphisms determine platelet aggregation in aspirin-treated individuals. Aim To identify platelet-related single nucleotide polymorphisms (SNPs) influencing platelet aggregation during aspirin treatment. Furthermore, we explored to what extent changes in cyclooxygenase-1 activity and platelet activation may explain such influence. Methods We included 985 Danish patients with stable coronary artery disease treated with aspirin 75 mg/day mono antiplatelet therapy. Patients were genotyped for 16 common SNPs in platelet-related genes using standard PCR-based methods (TaqMan). Platelet aggregation was evaluated by whole blood platelet aggregometry employing Multiplate Analyzer (agonists: arachidonic acid and collagen) and VerifyNow Aspirin. Serum thromboxane B2 was measured to confirm aspirin adherence and was used as a marker of cyclooxygenase-1 activity. Soluble P-selectin was used as marker of platelet activation. Platelet aggregation, cyclooxygenase-1 activity, and platelet activation were compared across genotypes in adjusted analyses. Results The A-allele of the rs12041331 SNP in the platelet endothelial aggregation receptor-1 (PEAR1) gene was associated with reduced platelet aggregation and increased platelet activation, but not with cyclooxygenase-1 activity. Platelet aggregation was unaffected by the other SNPs analyzed. Conclusion A common genetic variant in PEAR1 (rs12041331) reproducibly influenced platelet aggregation in aspirin-treated patients with coronary artery disease. The exact biological mechanism remains elusive, but the effect of this polymorphism may be related to changes in platelet activation. Furthermore, 14 SNPs previously suggested to influence aspirin efficacy were not associated with on-aspirin platelet aggregation. Clinical Trial Registration

  5. The influence of bioaugmentation and biosurfactant addition on bioremediation efficiency of diesel-oil contaminated soil: feasibility during field studies.

    PubMed

    Szulc, Alicja; Ambrożewicz, Damian; Sydow, Mateusz; Ławniczak, Łukasz; Piotrowska-Cyplik, Agnieszka; Marecik, Roman; Chrzanowski, Łukasz

    2014-01-01

    The study focused on assessing the influence of bioaugmentation and addition of rhamnolipids on diesel oil biodegradation efficiency during field studies. Initial laboratory studies (measurement of emitted CO2 and dehydrogenase activity) were carried out in order to select the consortium for bioaugmentation as well as to evaluate the most appropriate concentration of rhamnolipids. The selected consortium consisted of following bacterial taxa: Aeromonas hydrophila, Alcaligenes xylosoxidans, Gordonia sp., Pseudomonas fluorescens, Pseudomonas putida, Rhodococcus equi, Stenotrophomonas maltophilia, Xanthomonas sp. It was established that the application of rhamnolipids at 150 mg/kg of soil was most appropriate in terms of dehydrogenase activity. Based on the obtained results, four treatment methods were designed and tested during 365 days of field studies: I) natural attenuation; II) addition of rhamnolipids; III) bioaugmentation; IV) bioaugmentation and addition of rhamnolipids. It was observed that bioaugmentation contributed to the highest diesel oil biodegradation efficiency, whereas the addition of rhamnolipids did not notably influence the treatment process. PMID:24291585

  6. Minding the gap: Frequency of indels in mtDNA control region sequence data and influence on population genetic analyses

    USGS Publications Warehouse

    Pearce, J.M.

    2006-01-01

    Insertions and deletions (indels) result in sequences of various lengths when homologous gene regions are compared among individuals or species. Although indels are typically phylogenetically informative, occurrence and incorporation of these characters as gaps in intraspecific population genetic data sets are rarely discussed. Moreover, the impact of gaps on estimates of fixation indices, such as FST, has not been reviewed. Here, I summarize the occurrence and population genetic signal of indels among 60 published studies that involved alignments of multiple sequences from the mitochondrial DNA (mtDNA) control region of vertebrate taxa. Among 30 studies observing indels, an average of 12% of both variable and parsimony-informative sites were composed of these sites. There was no consistent trend between levels of population differentiation and the number of gap characters in a data block. Across all studies, the average influence on estimates of ??ST was small, explaining only an additional 1.8% of among population variance (range 0.0-8.0%). Studies most likely to observe an increase in ??ST with the inclusion of gap characters were those with < 20 variable sites, but a near equal number of studies with few variable sites did not show an increase. In contrast to studies at interspecific levels, the influence of indels for intraspecific population genetic analyses of control region DNA appears small, dependent upon total number of variable sites in the data block, and related to species-specific characteristics and the spatial distribution of mtDNA lineages that contain indels. ?? 2006 Blackwell Publishing Ltd.

  7. Dyslexia and language impairment associated genetic markers influence cortical thickness and white matter in typically developing children.

    PubMed

    Eicher, John D; Montgomery, Angela M; Akshoomoff, Natacha; Amaral, David G; Bloss, Cinnamon S; Libiger, Ondrej; Schork, Nicholas J; Darst, Burcu F; Casey, B J; Chang, Linda; Ernst, Thomas; Frazier, Jean; Kaufmann, Walter E; Keating, Brian; Kenet, Tal; Kennedy, David; Mostofsky, Stewart; Murray, Sarah S; Sowell, Elizabeth R; Bartsch, Hauke; Kuperman, Joshua M; Brown, Timothy T; Hagler, Donald J; Dale, Anders M; Jernigan, Terry L; Gruen, Jeffrey R

    2016-03-01

    Dyslexia and language impairment (LI) are complex traits with substantial genetic components. We recently completed an association scan of the DYX2 locus, where we observed associations of markers in DCDC2, KIAA0319, ACOT13, and FAM65B with reading-, language-, and IQ-related traits. Additionally, the effects of reading-associated DYX3 markers were recently characterized using structural neuroimaging techniques. Here, we assessed the neuroimaging implications of associated DYX2 and DYX3 markers, using cortical volume, cortical thickness, and fractional anisotropy. To accomplish this, we examined eight DYX2 and three DYX3 markers in 332 subjects in the Pediatrics Imaging Neurocognition Genetics study. Imaging-genetic associations were examined by multiple linear regression, testing for influence of genotype on neuroimaging. Markers in DYX2 genes KIAA0319 and FAM65B were associated with cortical thickness in the left orbitofrontal region and global fractional anisotropy, respectively. KIAA0319 and ACOT13 were suggestively associated with overall fractional anisotropy and left pars opercularis cortical thickness, respectively. DYX3 markers showed suggestive associations with cortical thickness and volume measures in temporal regions. Notably, we did not replicate association of DYX3 markers with hippocampal measures. In summary, we performed a neuroimaging follow-up of reading-, language-, and IQ-associated DYX2 and DYX3 markers. DYX2 associations with cortical thickness may reflect variations in their role in neuronal migration. Furthermore, our findings complement gene expression and imaging studies implicating DYX3 markers in temporal regions. These studies offer insight into where and how DYX2 and DYX3 risk variants may influence neuroimaging traits. Future studies should further connect the pathways to risk variants associated with neuroimaging/neurocognitive outcomes. PMID:25953057

  8. Strong genetic influences on measures of behavioral-regulation among inbred rat strains

    PubMed Central

    Richards, Jerry B.; Lloyd, David R.; Kuehlewind, Brandon; Militello, Leah; Paredez, Marita; Solberg -Woods, Leah; Palmer, Abraham A.

    2013-01-01

    A fundamental challenge for any complex nervous system is to regulate behavior in response to environmental challenges. Three measures of behavioral regulation were tested in a panel of 8 inbred rat strains. These measures were; 1) sensation seeking as assessed by locomotor response to novelty and the sensory reinforcing effects of light onset, 2) attention and impulsivity, as measured by a choice reaction time task, and 3) impulsivity as measured by a delay discounting task. Deficient behavioral regulation has been linked to a number of psychopathologies, including ADHD, Schizophrenia, Autism, drug abuse and eating disorders. Eight inbred rat strains (August Copenhagen Irish, Brown Norway, Buffalo, Fischer 344, Wistar Kyoto, Spontaneous Hypertensive Rat, Lewis, Dahl Salt Sensitive) were tested. With n=9 for each strain, we observed robust strain differences for all tasks; heritability was estimated between 0.43 and 0.66. Performance of the 8 inbred rat strains on the choice reaction time task was compared to the performance of out bred Sprague Dawley (n=28) and Heterogeneous strain rats (n=48). The results indicate a strong genetic influence on complex tasks related to behavioral regulation and indicate that some of measures tap common genetically-driven processes. Furthermore, our results establish the potential for future studies aimed at identifying specific alleles that influence variability for these traits. Identification of such alleles could contribute to our understanding of the molecular genetic basis of behavioral regulation, which is of fundamental importance and likely contributes to multiple psychiatric disorders. PMID:23710681

  9. Overlap and Specificity of Genetic and Environmental Influences on Mathematics and Reading Disability in 10-Year-Old Twins

    ERIC Educational Resources Information Center

    Kovas, Y.; Haworth, C. M. A.; Harlaar, N.; Petrill, S. A.; Dale, P. S.; Plomin, R.

    2007-01-01

    Background: To what extent do genetic and environmental influences on reading disability overlap with those on mathematics disability? Multivariate genetic research on the normal range of variation in unselected samples has led to a Generalist Genes Hypothesis which posits that the same genes largely affect individual differences in these…

  10. Do Different Measures Tap the Same Genetic Influences? A Multi-Method Study of Activity Level in Young Twins

    ERIC Educational Resources Information Center

    Saudino, Kimberly J.

    2009-01-01

    Activity level (AL) is a highly salient feature of child behaviour that has been linked to developmental outcome. Twin studies of parent-rated, observer-rated and mechanically assessed AL in childhood find that AL is genetically influenced. Few studies, however, consider whether different methods of assessing AL have a shared genetic etiology.…

  11. Additive Effects of Word Frequency and Stimulus Quality: The Influence of Trial History and Data Transformations

    ERIC Educational Resources Information Center

    Balota, David A.; Aschenbrenner, Andrew J.; Yap, Melvin J.

    2013-01-01

    A counterintuitive and theoretically important pattern of results in the visual word recognition literature is that both word frequency and stimulus quality produce large but additive effects in lexical decision performance. The additive nature of these effects has recently been called into question by Masson and Kliegl (in press), who used linear…

  12. 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

  13. The influence of density and sex on patterns of fine-scale genetic structure.

    PubMed

    Busch, Joseph D; Waser, Peter M; DeWoody, J Andrew

    2009-09-01

    Natal philopatry is expected to limit gene flow and give rise to fine-scale spatial genetic structure (SGS). The banner-tailed kangaroo rat (Dipodomys spectabilis) is unusual among mammals because both sexes are philopatric. This provides an opportunity to study patterns of local SGS faced by philopatric and dispersing animals. We evaluated SGS using spatial genetic autocorrelation in two D. spectabilis populations (Rucker and Portal) over a 14-year temporal series that covered low, medium, and high population densities. Significantly positive autocorrelation values exist up to 800 m at Rucker and 400 m at Portal. Density was negatively associated with SGS (low >medium >high), and suggests that increases in density are accompanied by greater spatial overlap of kin clusters. With regard to sex-bias, we find a small but significant increase in the SGS level of males over females, which matches the greater dispersal distances observed in females. We observed variation in SGS over the ecological time scale of this study, indicating genetic structure is temporally labile. Our study is the first temporal exploration of the influence of density and sex on spatial genetic autocorrelation in vertebrate populations. Because few organisms maintain discreet kin clusters, we predict that density will be negatively associated with SGS in other species. PMID:19453729

  14. New Genetic and Linguistic Analyses Show Ancient Human Influence on Baobab Evolution and Distribution in Australia

    PubMed Central

    Rangan, Haripriya; Bell, Karen L.; Baum, David A.; Fowler, Rachael; McConvell, Patrick; Saunders, Thomas; Spronck, Stef; Kull, Christian A.; Murphy, Daniel J.

    2015-01-01

    This study investigates the role of human agency in the gene flow and geographical distribution of the Australian baobab, Adansonia gregorii. The genus Adansonia is a charismatic tree endemic to Africa, Madagascar, and northwest Australia that has long been valued by humans for its multiple uses. The distribution of genetic variation in baobabs in Africa has been partially attributed to human-mediated dispersal over millennia, but this relationship has never been investigated for the Australian species. We combined genetic and linguistic data to analyse geographic patterns of gene flow and movement of word-forms for A. gregorii in the Aboriginal languages of northwest Australia. Comprehensive assessment of genetic diversity showed weak geographic structure and high gene flow. Of potential dispersal vectors, humans were identified as most likely to have enabled gene flow across biogeographic barriers in northwest Australia. Genetic-linguistic analysis demonstrated congruence of gene flow patterns and directional movement of Aboriginal loanwords for A. gregorii. These findings, along with previous archaeobotanical evidence from the Late Pleistocene and Holocene, suggest that ancient humans significantly influenced the geographic distribution of Adansonia in northwest Australia. PMID:25830225

  15. New genetic and linguistic analyses show ancient human influence on baobab evolution and distribution in Australia.

    PubMed

    Rangan, Haripriya; Bell, Karen L; Baum, David A; Fowler, Rachael; McConvell, Patrick; Saunders, Thomas; Spronck, Stef; Kull, Christian A; Murphy, Daniel J

    2015-01-01

    This study investigates the role of human agency in the gene flow and geographical distribution of the Australian baobab, Adansonia gregorii. The genus Adansonia is a charismatic tree endemic to Africa, Madagascar, and northwest Australia that has long been valued by humans for its multiple uses. The distribution of genetic variation in baobabs in Africa has been partially attributed to human-mediated dispersal over millennia, but this relationship has never been investigated for the Australian species. We combined genetic and linguistic data to analyse geographic patterns of gene flow and movement of word-forms for A. gregorii in the Aboriginal languages of northwest Australia. Comprehensive assessment of genetic diversity showed weak geographic structure and high gene flow. Of potential dispersal vectors, humans were identified as most likely to have enabled gene flow across biogeographic barriers in northwest Australia. Genetic-linguistic analysis demonstrated congruence of gene flow patterns and directional movement of Aboriginal loanwords for A. gregorii. These findings, along with previous archaeobotanical evidence from the Late Pleistocene and Holocene, suggest that ancient humans significantly influenced the geographic distribution of Adansonia in northwest Australia. PMID:25830225

  16. Influence of polymer additives on turbulence in von Karman swirling flow between two disks. II

    NASA Astrophysics Data System (ADS)

    Burnishev, Yuri; Steinberg, Victor

    2016-03-01

    We present the experimental studies of the influence of polymer additives on the statistical and scaling properties of the fully developed turbulent regime in a von Karman swirling flow driven either by the smooth or bladed disks using only the global measurements of torque Γ and pressure p fluctuations in water- and water-sugar-based solutions of different viscosities, or elasticity El, and different polymer concentrations ϕ as a function of Re in the same apparatus. There are three highlights achieved and reported in the paper: (i) An observation of turbulent drag reduction (TDR) at both the inertial and viscous flow forcing, in a contradiction to a currently accepted opinion that only the viscous forcing leads to TDR, and the unexpected drastic difference in the transition to the fully developed turbulent and TDR regimes in von Karman swirling flow of water-based polymer solutions depending on the way of the forcing; (ii) a continuous transition to TDR in both the normalized torque drop and the rms pressure fluctuations drop and universality in scaling behavior of Cf in an agreement with theoretical predictions; and (iii) the dramatic differences in the appearance of the frequency power spectra of Γ and in particular p due to the different ways of the forcing are also observed. We discuss and summarize further the results in accordance with these three main achievements. The main message of these studies is that both the inertial forcing and viscous forcing of von Karman swirling flow between two counter-rotating disks lead to TDR in the sharp contrast to the currently accepted opinion [O. Cadot et al., "Turbulent drag reduction in a closed flow system: Boundary layer versus bulk effects," Phys. Fluids 10, 426 (1998); D. Bonn et al., "From scale scales to large scales in three-dimensional turbulence: The effect of diluted polymers," Phys. Rev. E 47, R28 (1993); and D. Bonn et al., "Turbulent drag reduction by polymers," J. Phys.: Condens. Matter 17, S1195

  17. Influence of defatted soy flour addition on the quality and stability of pretzel type product.

    PubMed

    Naik, Haroon Rashid; Sekhon, K S

    2014-03-01

    Effect of soya flour addition to 70% extraction bread wheat flour (PBW-343) at (0, 5, 10, 20 & 30%) was investigated for physico-chemical, dough handling and pretzel making properties. Results revealed that with increasing DSF addition, farinogram characteristics; water absorption, arrival time, dough development time and dough stability increased while mixing tolerance index and degree of softening decreased. Amylogram characteristics gelatinization temperature, peak viscosity, peak temperature and viscosity at 95 °C decreased with extended rate of DSF addition. Pretzels developed with different levels of DSF addition observed decrease in moisture, fat, non reducing sugars and starch where as ash, protein, reducing and total sugars increased compared to control. Calories calculated from proximate composition showed lower values than control due to high protein and low fat soy flour addition. Minerals increased significantly with increased levels of defatted soy flour addition. Organoleptic evaluation revealed that 5% level of soy flour blended pretzels were found best with respect to texture, colour and flavor on the basis of mean acceptability scores. Pretzels recorded shelf life of 90 days in laminated pouches irrespective of the level of DSF addition. PMID:24587534

  18. Influence of carbohydrate addition on nitrogen transformations and greenhouse gas emissions of intensive aquaculture system.

    PubMed

    Hu, Zhen; Lee, Jae Woo; Chandran, Kartik; Kim, Sungpyo; Sharma, Keshab; Khanal, Samir Kumar

    2014-02-01

    Aquaculture is one of the fastest-growing segments of the food economy in modern times. It is also being considered as an important source of greenhouse gas (GHG) emissions. To date, limited studies have been conducted on GHG emissions from aquaculture system. In this study, daily addition of fish feed and soluble starch at a carbon-to-nitrogen (C/N) ratio of 16:1 (w/w) was used to examine the effects of carbohydrate addition on nitrogen transformations and GHG emissions in a zero-water exchange intensive aquaculture system. The addition of soluble starch stimulated heterotrophic bacterial growth and denitrification, which led to lower total ammonia nitrogen, nitrite and nitrate concentrations in aqueous phase. About 76.2% of the nitrogen output was emitted in the form of gaseous nitrogen (i.e., N2 and N2O) in the treatment tank (i.e., aquaculture tank with soluble starch addition), while gaseous nitrogen accounted for 33.3% of the nitrogen output in the control tank (i.e., aquaculture tank without soluble starch addition). Although soluble starch addition reduced daily N2O emissions by 83.4%, it resulted in an increase of daily carbon dioxide (CO2) emissions by 91.1%. Overall, starch addition did not contribute to controlling the GHG emissions from the aquaculture system. PMID:24140689

  19. Genetic and environmental influences on the junior temperament and character inventory in a preadolescent twin sample.

    PubMed

    Isen, Joshua D; Baker, Laura A; Raine, Adrian; Bezdjian, Serena

    2009-01-01

    This study evaluated the genetic and environmental structure of personality variables from the Junior Temperament and Character Inventory (JTCI), in 605 pairs of 9- and 10-year old twins. There is a paucity of information on the biometric structure of temperament and character traits in preadolescent children. Latent factor models were fit to the subscales/items of each trait as a method of estimating genetic and environmental effects on true score variance, especially since internal consistency and reliability were moderate or low for some scales (particularly Reward Dependence and Persistence). Shared environmental influences on Cooperativeness were substantial. Significant heritability estimates were obtained for Self-directedness and Harm Avoidance, but not Novelty Seeking, Reward Dependence or Persistence. With the exception of Harm Avoidance, each of the scales failed to show measurement invariance with respect to sex, suggesting these scales may differ in meaning for boys and girls at this age. PMID:19043782

  20. Influence of mineral oil and additives on microhardness and surface chemistry of magnesium oxide (001) surface

    NASA Technical Reports Server (NTRS)

    Miyoshi, K.; Shigaki, H.; Buckley, D. H.

    1982-01-01

    X-ray photoelectron spectroscopy analyses and hardness experiments were conducted with cleaved magnesium oxide /001/ surfaces. The magnesium oxide bulk crystals were cleaved into specimens along the /001/ surface, and indentations were made on the cleaved surface in laboratory air, in nitrogen gas, or in degassed mineral oil with and without an additive while not exposing specimen surface to any other environment. The various additives examined contained sulfur, phosphorus, chlorine, or oleic acid. The sulfur-containing additive exhibited the highest hardness and smallest dislocation patterns evidencing plastic deformation; the chlorine-containing additive exhibited the lowest hardness and largest dislocation patterns evidencing plastic deformation. Hydrocarbon and chloride (MgCl2) films formed on the magnesium oxide surface. A chloride film was responsible for the lowest measured hardness.

  1. Influence of cementitious additions on rheological and mechanical properties of reactive powder concretes

    NASA Astrophysics Data System (ADS)

    Zenati, A.; Arroudj, K.; Lanez, M.; Oudjit, M. N.

    2009-11-01

    Following needs of concrete market and the economic and ecological needs, several researchers, all over the world, studied the beneficial effect which the incorporation of the mineral additions in Portland cement industry can bring. It was shown that the incorporation of local mineral additions can decrease the consumption of crushing energy of cements, and reduce the CO2 emission. Siliceous additions, moreover their physical role of filling, play a chemical role pozzolanic. They contribute to improving concrete performances and thus their durability. The abundance of dunes sand and blast furnace slag in Algeria led us to study their effect like cementitious additions. The objective of this paper is to study the effect of the incorporation of dunes sand and slag, finely ground on rheological and mechanical properties of reactive powder concretes containing ternary binders.

  2. The influence of developmental stages and protective additives on cryopreservation of surf clam (Spisula sachalinensis) larvae.

    PubMed

    Choi, Youn Hee; Lee, Jeong Yong; Chang, Young Jin

    2008-07-01

    This study was performed to find out the optimal larval stage and the most desirable protective additives for cryopreservation of surf clam, Spisula sachalinensis larvae. The survival rates of frozen-thawed larvae increased with post developmental stage. The highest value of 96.1 +/- 1.0% was achieved using umbo stage larva as developmental stage and 0.2 M sucrose as protective additive. PMID:19195381

  3. Making (up) the grade? estimating the genetic and environmental influences of discrepancies between self-reported grades and official GPA scores.

    PubMed

    Schwartz, Joseph A; Beaver, Kevin M

    2015-05-01

    Academic achievement has been found to have a pervasive and substantial impact on a wide range of developmental outcomes and has also been implicated in the critical transition from adolescence into early adulthood. Previous research has revealed that self-reported grades tend to diverge from official transcript grade point average (GPA) scores, with students being more likely to report inflated scores. Making use of a sample of monozygotic twin (N = 282 pairs), dizygotic twin (N = 441 pairs), and full sibling (N = 1,757 pairs) pairs from the National Longitudinal Study of Adolescent Health (Add Health; 65 % White; 50 % male; mean age = 16.14), the current study is the first to investigate the role that genetic and environmental factors play in misreporting grade information. A comparison between self-reported GPA (mean score of 2.86) and official transcript GPA scores (mean score of 2.44) revealed that self-reported scores were approximately one-half letter grade greater than official scores. Liability threshold models revealed that additive genetic influences explained between 40 and 63 % of the variance in reporting inflated grades and correctly reporting GPA, with the remaining variance explained by the nonshared environment. Conversely, 100 % of the variance in reporting deflated grade information was explained by nonshared environmental influences. In an effort to identify specific nonshared environmental influences on reporting accuracy, multivariate models that adequately control for genetic influences were estimated and revealed that siblings with lower transcript GPA scores were significantly less likely to correctly report their GPA and significantly more likely to report inflated GPA scores. Additional analyses revealed that verbal IQ and self-control were not significantly associated with self-reported GPA accuracy after controlling for genetic influences. These findings indicate that previous studies that implicate verbal IQ and self

  4. Genetic influences on the overlap between low IQ and antisocial behavior in young children.

    PubMed

    Koenen, Karestan C; Caspi, Avshalom; Moffitt, Terrie E; Rijsdijk, Fruhling; Taylor, Alan

    2006-11-01

    The well-documented relation between the phenotypes of low IQ and childhood antisocial behavior could be explained by either common genetic influences or environmental influences. These competing explanations were examined through use of the Environmental Risk Longitudinal Twin Study 1994-1995 cohort (Moffitt & the E-Risk Study Team, 2002) of 1,116 twin pairs and their families. Children's IQ was assessed via individual testing at age 5 years. Mothers and teachers reported on children's antisocial behavior at ages 5 and 7 years. Low IQ was related to antisocial behavior at age 5 years and predicted relatively higher antisocial behavior scores at age 7 years when antisocial behavior at age 5 years was controlled. This association was significantly stronger among boys than among girls. Genetic influences common to both phenotypes explained 100% of the low IQ-antisocial behavior relation in boys. Findings suggest that specific candidate genes and neurobiological processes should be tested in relation to both phenotypes. PMID:17100536

  5. Peer Influence, Genetic Propensity, and Binge Drinking: A Natural Experiment and a Replication.

    PubMed

    Guo, Guang; Li, Yi; Wang, Hongyu; Cai, Tianji; Duncan, Greg J

    2015-11-01

    The authors draw data from the College Roommate Study (ROOM) and the National Longitudinal Study of Adolescent Health to investigate gene-environment interaction effects on youth binge drinking. In ROOM, the environmental influence was measured by the precollege drinking behavior of randomly assigned roommates. Random assignment safeguards against friend selection and removes the threat of gene-environment correlation that makes gene-environment interaction effects difficult to interpret. On average, being randomly assigned a drinking peer as opposed to a nondrinking peer increased college binge drinking by 0.5-1.0 episodes per month, or 20%-40% the average amount of binge drinking. However, this peer influence was found only among youths with a medium level of genetic propensity for alcohol use; those with either a low or high genetic propensity were not influenced by peer drinking. A replication of the findings is provided in data drawn from Add Health. The study shows that gene-environment interaction analysis can uncover social-contextual effects likely to be missed by traditional sociological approaches. PMID:26900620

  6. Integrative Review of Genetic Factors Influencing Neurodevelopmental Outcomes in Preterm Infants.

    PubMed

    Blair, Lisa M; Pickler, Rita H; Anderson, Cindy

    2016-03-01

    Preterm infants are at elevated risk for a host of neurodevelopmental problems, including disorders that appear later in life. Gene-environment interactions and prematurity may combine to increase the risk for poor neurodevelopmental outcomes. Increasing evidence supports a genetic link to risk for atypical development; however, no genomic risk profiles are currently used for infants without apparent genetic disorders. The purpose of this review was to synthesize recent evidence of genetic associations with atypical neurodevelopmental outcomes that may affect preterm infants who do not have a rare genetic disease. Electronic and hand-search strategies were used to find relevant articles that were English-language, peer-reviewed primary research or meta-analysis reports published between July 2009 and July 2014, involving human participants. Articles included in the analysis (N = 29) used a wide range of study designs and methodologies, complicating the analysis. An integrative-review design was used to synthesize the data. Numerous genes (n = 43) and additional large deletion copy number variants were associated with neurodevelopmental outcomes, including cognition, attention, perception, psychiatric disease, autism spectrum disorder, cerebral palsy, infant behavior, and alterations in brain architecture. The creation of genetic risk profiles for complex disorders of neurodevelopment is presently hindered by inconsistent genetic-association evidence, methodological considerations, reporting problems, and lack of replication. However, several avenues of investigation offer promise, including large (>100 kb) copy number variants and the candidate genes MET, NRG3, and SLC6A4, each of which were reported to have associations with neurodevelopmental outcomes in multiple, high-quality studies. PMID:26374169

  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. Stability and Change in Genetic and Environmental Influences on Well-Being in Response to an Intervention.

    PubMed

    Haworth, Claire M A; Nelson, S Katherine; Layous, Kristin; Carter, Kathryn; Jacobs Bao, Katherine; Lyubomirsky, Sonja; Plomin, Robert

    2016-01-01

    Genetic and environmental influences on complex traits can change in response to developmental and environmental contexts. Here we explore the impact of a positive activity intervention on the genetic and environmental influences on well-being and mental health in a sample of 750 adolescent twins. Twins completed a 10-week online well-being intervention, consisting of kindness and gratitude tasks and matched control activities. The results showed significant improvements both in well-being and in internalizing symptoms in response to the intervention activities. We used multivariate twin analyses of repeated measures, tracking stability and change in genetic and environmental influences, to assess the impact of this environmental intervention on these variance components. The heritability of well-being remained high both before and after the intervention, and the same genetic effects were important at each stage, even as well-being increased. The overall magnitude of environmental influences was also stable across the intervention; however, different non-shared environmental influences emerged during the intervention. Our study highlights the value of exploring the innovations in non-shared environmental influences that could provide clues to the mechanisms behind improvements in well-being. The findings also emphasize that even traits strongly influenced by genetics, like well-being, are subject to change in response to environmental interventions. PMID:27227410

  9. Stability and Change in Genetic and Environmental Influences on Well-Being in Response to an Intervention

    PubMed Central

    Haworth, Claire M. A.; Nelson, S. Katherine; Layous, Kristin; Carter, Kathryn; Jacobs Bao, Katherine; Lyubomirsky, Sonja; Plomin, Robert

    2016-01-01

    Genetic and environmental influences on complex traits can change in response to developmental and environmental contexts. Here we explore the impact of a positive activity intervention on the genetic and environmental influences on well-being and mental health in a sample of 750 adolescent twins. Twins completed a 10-week online well-being intervention, consisting of kindness and gratitude tasks and matched control activities. The results showed significant improvements both in well-being and in internalizing symptoms in response to the intervention activities. We used multivariate twin analyses of repeated measures, tracking stability and change in genetic and environmental influences, to assess the impact of this environmental intervention on these variance components. The heritability of well-being remained high both before and after the intervention, and the same genetic effects were important at each stage, even as well-being increased. The overall magnitude of environmental influences was also stable across the intervention; however, different non-shared environmental influences emerged during the intervention. Our study highlights the value of exploring the innovations in non-shared environmental influences that could provide clues to the mechanisms behind improvements in well-being. The findings also emphasize that even traits strongly influenced by genetics, like well-being, are subject to change in response to environmental interventions. PMID:27227410

  10. Influence of oxide-based sintering additives on densification and mechanical behavior of tricalcium phosphate (TCP).

    PubMed

    Bhatt, Himesh A; Kalita, Samar J

    2007-05-01

    In this research, we studied and analyzed the effects of four different oxide-based sintering additives on densification, mechanical behavior, biodegradation and biocompatibility of tricalcium phosphate (TCP) bioceramics. Selective sintering additives were introduced into pure TCP ceramics, in small quantities, through homogeneous mixing, using a mortar and pestle. The consequent powders of different compositions were pressed into cylindrical compacts, uniaxially and sintered at elevated temperatures, 1150 degrees C and 1250 degrees C, separately in a muffle furnace. X-ray powder diffraction technique was used to analyze the phase-purity of TCP after sintering. Hardness of these sintered specimens was evaluated using a Vickers hardness tester. Sintered cylindrical samples were tested under uniaxial compressive loading, as a function of composition to determine their failure strength. Biodegradation studies conducted using simulated body fluid under dynamic environment, revealed that these additives could control the rate of resorption and hardness degradation of TCP ceramics. PMID:17211718

  11. Addition of Dispersoid Titanium Oxide Inclusions in Steel and Their Influence on Grain Refinement

    NASA Astrophysics Data System (ADS)

    Kiviö, Miia; Holappa, Lauri; Iung, Thierry

    2010-12-01

    In this article, the addition of dispersoid titanium oxide inclusions into liquid steel, the effect of additions on the inclusions found in the steel and on grain refinement, and acicular ferrite formation were studied. Different TiO2-containing materials and addition procedures into liquid steel were tested in experimental heats to obtain inclusions that promote grain refinement and acicular ferrite formation in C-Mn-Cr steel. Different additives with metallic Ti and TiO2 were added into the steel melt just before casting or into the mold during casting to create Ti-containing inclusions. The aluminum content in steel was lowered by an addition of iron oxide. The samples taken from steel melts and ingots were studied with a scanning electron microscope to find inclusions and to analyze them. Thermodynamic calculations showed that the Al content should be low (<50 ppm) to obtain Ti oxide dominating inclusions, whereas Al2O3 were formed at higher Al contents. When TiO2 was added late before casting, the oxide inclusions were Ti oxides and were mixed with Ti, Al, and Mn oxides. Small inclusions around 1 μm were detected in the samples with TiO x or TiN as the main component. It could be concluded that the additions resulted in a clearly higher number and in a smaller size of TiO x inclusions than just by adding metallic Ti. Selected samples were brought for subsequent hot rolling and heat-treatment experiments to find out the grain-refining effect and the eventual formation of acicular ferrite. Grain refinement was observed clearly, but the presence of acicular ferrite could not be confirmed definitely.

  12. Effect of Brahman genetic influence on collagen enzymatic crosslinking gene expression and meat tenderness.

    PubMed

    Gonzalez, J M; Johnson, D D; Elzo, M A; White, M C; Stelzleni, A M; Johnson, S E

    2014-01-01

    to Brahman genetic influence. PMID:24669867

  13. Influence of Additive and Multiplicative Structure and Direction of Comparison on the Reversal Error

    ERIC Educational Resources Information Center

    González-Calero, José Antonio; Arnau, David; Laserna-Belenguer, Belén

    2015-01-01

    An empirical study has been carried out to evaluate the potential of word order matching and static comparison as explanatory models of reversal error. Data was collected from 214 undergraduate students who translated a set of additive and multiplicative comparisons expressed in Spanish into algebraic language. In these multiplicative comparisons…

  14. Influence of an organic and an inorganic additive on the crystallization of dicalcium phosphate dihydrate

    NASA Astrophysics Data System (ADS)

    Anee, T. K.; Meenakshi Sundaram, N.; Arivuoli, D.; Ramasamy, P.; Narayana Kalkura, S.

    2005-12-01

    Dicalcium phosphate dihydrate (DCPD) was crystallized by single diffusion method under physiological pH, in the presence of cobalt and malic acid. The morphology, composition and microstructure of the grown crystals were analyzed using EDTA titration, UV-Visible, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), atomic absorption spectroscopy (AAS) and scanning electron microscopy (SEM). These analyses showed that the grown crystals were Co 2+-doped DCPD. The temperature has influenced the dopant entry into DCPD crystals, but the dopant content and temperature were having not much influence on the crystal morphology. In pathological crystallization, the size and morphology are very important since they decide the mode of treatment to adopt. The morphological changes arise when the growth assay is doped with cobalt and malic acid. The effect of malic acid on the crystallization was highly specific, adsorbing on certain crystal faces during growth and producing different morphologies. At higher concentration, the morphology showed a feature frequently encountered in biomineralization, the orientational ordering in [0 0 1], leading to elongated crystals.

  15. Influence of Additional Tensile Force on Springback of Tube Under Rotary Draw Bending

    NASA Astrophysics Data System (ADS)

    E, Daxin; Guan, Zhiping; Chen, Jisheng

    2012-11-01

    According to the characteristics of tube under rotary draw bending, the formulae were derived to calculate the springback angles of tubes subjected to combined bending and additional tension. Especially, as the neutral layer (NL) moves to the inner concave surface of the bend, the analytical values agree very well with the experimental results. The analysis shows that the additional tensile force causes the movement of the NL toward the bending center and makes the deformation behavior under rotary draw bending or numerically controlled (NC) bending different with that under pure bending, and also it could enlarge the springback angle if taking the movement of the NL into consideration. In some range, the springback angle would increase slightly with larger wall thickness/diameter ratio and decrease with wall thinning. The investigation could provide reference for the analysis of rotary draw bending, the design of NC tube bender and the related techniques.

  16. Influence of nutrient additions on cadmium bioaccumulation by aquatic invertebrates in littoral enclosures

    SciTech Connect

    Currie, R.S.; Muir, D.C.G.; Fairchild, W.L.; Holoka, M.H.; Hecky, R.E.

    1998-12-01

    Cadmium distribution and bioaccumulation were examined over a 2-year period (1991--1992) in two nutrient-enriched and two control littoral enclosures and in the littoral zone in Lake 382 (L382). Lake 382, a small oligotrophic lake, is located within the Experimental Lakes Area in northwestern Ontario, Canada, and received experimental Cd additions from 1987 to 1992. In the second year of this study, chlorophyll a and suspended C concentrations in the nutrient-enriched enclosures increased by 6.6 and 3.4 times, respectively, compared to the controls. As a result of increased particulate produced by the nutrient additions, Cd concentrations in water from the nutrient-enriched enclosures were higher compared to the controls. Estimated Cd/C concentrations in water were lower in the nutrient-enriched enclosures relative to the controls because of higher particle concentrations. Effects on Cd bioaccumulation were limited even though mesotrophic to eutrophic conditions were reached in the nutrient-enriched enclosures had consistently higher Cd concentrations compared to the controls, but significant differences were not detected. Enhanced accumulation of Cd-rich particulate matter by these organisms may account for this trend. Mussels and crayfish accumulated significantly more Cd when exposed in the lake compared to the enclosures. This observation is due to elevated Cd water concentrations in the lake compared to the enclosures because of continued Cd additions to the lake. These results suggest that the water route of exposure is an important pathway for Cd accumulation by these organisms.

  17. Sex Differences in Genetic and Environmental Influences on Longitudinal Change in Functional Ability in Late Adulthood

    PubMed Central

    Ernsth-Bravell, Marie; Pedersen, Nancy L.

    2015-01-01

    Objectives. To determine the extent to which genetic and environmental factors contribute to individual and gender differences in aging of functional ability. Method. Twenty assessments of functional ability are collected as part of the longitudinal Swedish Adoption/Twin Study of Aging from 859 twins aged 50–88 at the first wave. Participants completed up to 6 assessments covering a 19-year period. Factor analysis was used to create 3 factors: flexibility, fine motor skills, and balance. Results. Latent growth curve analysis demonstrated increasing disability and variability after age 70. For flexibility, results indicated significant sex differences in mean change trajectories but no sex differences in components of variance. No sex differences were found for fine motor movement. For balance, there were no sex differences in mean change trajectories; however, there was significant genetic variance for changes in balance in women after age 70 but not for men. Discussion. Although idiosyncratic environmental influences account for a large part of increasing variance, correlated and shared rearing environmental effects were also evident. Thus, both microenvironmental (individual) and macroenvironmental (family and cultural) effects, as well as genetic factors, affect maintenance of functional ability in late adulthood. PMID:24398585

  18. GENETIC FACTORS INFLUENCING HEMOGLOBIN F LEVEL IN β-THALASSEMIA/HB E DISEASE.

    PubMed

    Ruangrai, Waraporn; Jindadamrongwech, Sumalee

    2016-01-01

    Genetic factors influencing Hb F content in adult red blood cells include β-thalassemia genotypes, co-inheritance of α-thalassemia traits and single nucleotide polymorphisms (SNPs). Genotyping of α- and β-thalassemia and five SNPs in β-globin gene cluster previously identified in genome-wide association studies as being markers of elevated Hb F in β-thalassemia were performed in 81 subjects diagnosed with β-thalassemia/Hb E. Hb F levels are higher (0.9-7.1 g/dl) in subjects (n = 57) with the severe compared to mild β-thalassemia (0.8-2.5 g/ dl) (n = 4) genotypes, and are similarly low (0.7-3.5 g/dl) in those (n = 15) with α-thalassemia co-inheritance. Hb F levels in non-thalassemia controls (n = 150) range from 0 to 0.15 g/dl. The presence of homozygous minor alleles of the 5 SNPs are significant indicators of β-thalassemia/Hb E individuals with high Hb F (> 4 g/dl), independent of their thalassemia genotypes. Given that re-activation of γ-globin genes leads to amelioration of β-thalassemia severity, understanding how genetic factors up-regulate Hb F production may lead to possible therapeutic interventions, genetically or pharmacologically, of this debilitating disease in the not too distant future. PMID:27086429

  19. Genetic Influences on Physiological and Subjective Responses to an Aerobic Exercise Session among Sedentary Adults

    PubMed Central

    Karoly, Hollis C.; Stevens, Courtney J.; Magnan, Renee E.; Harlaar, Nicole; Hutchison, Kent E.; Bryan, Angela D.

    2012-01-01

    Objective. To determine whether genetic variants suggested by the literature to be associated with physiology and fitness phenotypes predicted differential physiological and subjective responses to a bout of aerobic exercise among inactive but otherwise healthy adults. Method. Participants completed a 30-minute submaximal aerobic exercise session. Measures of physiological and subjective responding were taken before, during, and after exercise. 14 single nucleotide polymorphisms (SNPs) that have been previously associated with various exercise phenotypes were tested for associations with physiological and subjective response to exercise phenotypes. Results. We found that two SNPs in the FTO gene (rs8044769 and rs3751812) were related to positive affect change during exercise. Two SNPs in the CREB1 gene (rs2253206 and 2360969) were related to change in temperature during exercise and with maximal oxygen capacity (VO2 max). The SLIT2 SNP rs1379659 and the FAM5C SNP rs1935881 were associated with norepinephrine change during exercise. Finally, the OPRM1 SNP rs1799971 was related to changes in norepinephrine, lactate, and rate of perceived exertion (RPE) during exercise. Conclusion. Genetic factors influence both physiological and subjective responses to exercise. A better understanding of genetic factors underlying physiological and subjective responses to aerobic exercise has implications for development and potential tailoring of exercise interventions. PMID:22899923

  20. Genetic and Environmental Influences on the Mental Health of Children: A Twin Study.

    PubMed

    Yin, Ping; Hou, Xiao; Qin, Qing; Deng, Wei; Hu, Hua; Luo, Qinghua; Du, Lian; Qiu, Haitang; Qiu, Tian; Fu, Yixiao; Meng, Huaqing; Li, Tao

    2016-08-01

    The current study explored the influences of genetic and environmental factors on the mental health of twins between ages 6 and 16. A total of 41 monozygotic (MZ) twins and 35 dizygotic twins were recruited. The psychological attributes and environmental information of children were evaluated. A significant correlation was found between twins in the diagnostic categories of any psychiatric disorder and attention deficit/hyperactivity disorder (ADHD)/hyperkinesis based on the Strengths and Difficulties Questionnaire scale in MZ twins. Furthermore, fathers' authoritarian parenting style was positively correlated with the probability of any psychiatric disorders and oppositional/conduct disorders, whereas mothers' authoritative parenting style was negatively correlated with the probability of any psychiatric disorders and ADHD/hyperkinesis. The probability of emotional disorders was negatively correlated with scores on the Stressful Life Events Scale. These results collectively suggest that genetic and environmental elements, such as parental rearing style and stressful life events, may influence children's mental health. [Journal of Psychosocial Nursing and Mental Health Services, 54(8), 29-34.]. PMID:27479477

  1. Influence of Concentration and Salinity on the Biodegradability of Organic Additives in Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Mouser, P. J.; Kekacs, D.

    2014-12-01

    One of the risks associated with the use of hydraulic fracturing technologies for energy development is the potential release of hydraulic fracturing-related fluids into surface waters or shallow aquifers. Many of the organic additives used in hydraulic fracturing fluids are individually biodegradable, but little is know on how they will attenuate within a complex organic fluid in the natural environment. We developed a synthetic hydraulic fracturing fluid based on disclosed recipes used by Marcellus shale operators to evaluate the biodegradation potential of organic additives across a concentration (25 to 200 mg/L DOC) and salinity gradient (0 to 60 g/L) similar to Marcellus shale injected fluids. In aerobic aqueous solutions, microorganisms removed 91% of bulk DOC from low SFF solutions and 57% DOC in solutions having field-used SFF concentrations within 7 days. Under high SFF concentrations, salinity in excess of 20 g/L inhibited organic compound biodegradation for several weeks, after which time the majority (57% to 75%) of DOC remained in solution. After SFF amendment, the initially biodiverse lake or sludge microbial communities were quickly dominated (>79%) by Pseudomonas spp. Approximately 20% of added carbon was converted to biomass while the remainder was respired to CO2 or other metabolites. Two alcohols, isopropanol and octanol, together accounted for 2-4% of the initial DOC, with both compounds decreasing to below detection limits within 7 days. Alcohol degradation was associated with an increase in acetone at mg/L concentrations. These data help to constrain the biodegradation potential of organic additives in hydraulic fracturing fluids and guide our understanding of the microbial communities that may contribute to attenuation in surface waters.

  2. Defining the Influence of Germline Variation on Metastasis Using Systems Genetics Approaches.

    PubMed

    Lee, M; Crawford, N P S

    2016-01-01

    Cancer is estimated to be responsible for 8 million deaths worldwide and over half a million deaths every year in the United States. The majority of cancer-related deaths in solid tumors is directly associated with the effects of metastasis. While the influence of germline factors on cancer risk and development has long been recognized, the contribution of hereditary variation to tumor progression and metastasis has only gained acceptance more recently. A variety of approaches have been used to define how hereditary variation influences tumor progression and metastasis. One approach that garnered much early attention was epidemiological studies of cohorts of cancer patients, which demonstrated that specific loci within the human genome are associated with a differential propensity for aggressive tumor development. However, a powerful, and somewhat underutilized approach has been the use of systems genetics approaches in transgenic mouse models of human cancer. Such approaches are typically multifaceted, and involve integration of multiple lines of evidence derived, for example, from genetic and transcriptomic screens of genetically diverse mouse models of cancer, coupled with bioinformatics analysis of human cancer datasets, and functional analysis of candidate genes. These methodologies have allowed for the identification of multiple hereditary metastasis susceptibility genes, with wide-ranging cellular functions including regulation of gene transcription, cell proliferation, and cell-cell adhesion. In this chapter, we review how each of these approaches have facilitated the identification of these hereditary metastasis modifiers, the molecular functions of these metastasis-associated genes, and the implications of these findings upon patient survival. PMID:27613130

  3. Influence of boar breeds or hybrid genetic composition on semen quality and seminal plasma biochemical variables.

    PubMed

    Žaja, Ivona Žura; Samardžija, Marko; Vince, Silvijo; Majić-Balić, Ivanka; Vilić, Marinko; Đuričić, Dražen; Milinković-Tur, Suzana

    2016-01-01

    The enzyme concentrations of seminal plasma are important for spermatozoa metabolism and function in boars. The need has arisen for introducing a biochemical evaluation of semen, along with the usual standard semen analyses. There are no data on the influence of boar breeds on the seminal plasma biochemical variables investigated in this study. Therefore, the objective was to determine the influence of breed and hybrid genetic composition of boars on semen quality and seminal plasma biochemical variables. Semen samples of 27 boars (Swedish Landrace, German Landrace, Large White, Pietrain and Pig Improvement Company hybrid-PIC-hybrid), aged between 1.5 and 3 years, were collected. After evaluation of semen quality, the seminal plasma was separated from the spermatozoa by centrifugation of semen. The seminal plasma was subjected to spectrophotometric analysis to determine alkaline phosphatase (ALP), acid phosphatase (ACP), γ-glutamyltransferase (GGT), creatine kinase (CK) and lactate dehydrogenase (LDH) and to atomic absorption spectrophotometric analysis to measure the concentration of calcium and magnesium. Conventional semen quality variables differed depending on breed and PIC-hybrid genetic composition, though these differences were typically insignificant. In the seminal plasma, significant differences were determined in enzyme activity (ALP, GGT, CK and LDH) and in calcium concentration among boars of different breeds. There are, therefore, differences in semen quality and significant differences in the seminal plasma biochemical variables among boars of different breeds and PIC-hybrid genetic composition. The data and differences in semen variables detected in the present study provide knowledge for enhancing evaluation and monitoring of boar reproductive potential, semen quality and explain the potential causes of boar infertility. PMID:26692346

  4. Identification and Validation of Genetic Variants that Influence Transcription Factor and Cell Signaling Protein Levels

    PubMed Central

    Hause, Ronald J.; Stark, Amy L.; Antao, Nirav N.; Gorsic, Lidija K.; Chung, Sophie H.; Brown, Christopher D.; Wong, Shan S.; Gill, Daniel F.; Myers, Jamie L.; To, Lida Anita; White, Kevin P.; Dolan, M. Eileen; Jones, Richard Baker

    2014-01-01

    Many genetic variants associated with human disease have been found to be associated with alterations in mRNA expression. Although it is commonly assumed that mRNA expression changes will lead to consequent changes in protein levels, methodological challenges have limited our ability to test the degree to which this assumption holds true. Here, we further developed the micro-western array approach and globally examined relationships between human genetic variation and cellular protein levels. We collected more than 250,000 protein level measurements comprising 441 transcription factor and signaling protein isoforms across 68 Yoruba (YRI) HapMap lymphoblastoid cell lines (LCLs) and identified 12 cis and 160 trans protein level QTLs (pQTLs) at a false discovery rate (FDR) of 20%. Whereas up to two thirds of cis mRNA expression QTLs (eQTLs) were also pQTLs, many pQTLs were not associated with mRNA expression. Notably, we replicated and functionally validated a trans pQTL relationship between the KARS lysyl-tRNA synthetase locus and levels of the DIDO1 protein. This study demonstrates proof of concept in applying an antibody-based microarray approach to iteratively measure the levels of human proteins and relate these levels to human genome variation and other genomic data sets. Our results suggest that protein-based mechanisms might functionally buffer genetic alterations that influence mRNA expression levels and that pQTLs might contribute phenotypic diversity to a human population independently of influences on mRNA expression. PMID:25087611

  5. What influences the worldwide genetic structure of sperm whales (Physeter macrocephalus)?

    PubMed

    Alexander, Alana; Steel, Debbie; Hoekzema, Kendra; Mesnick, Sarah L; Engelhaupt, Daniel; Kerr, Iain; Payne, Roger; Baker, C Scott

    2016-06-01

    The interplay of natural selection and genetic drift, influenced by geographic isolation, mating systems and population size, determines patterns of genetic diversity within species. The sperm whale provides an interesting example of a long-lived species with few geographic barriers to dispersal. Worldwide mtDNA diversity is relatively low, but highly structured among geographic regions and social groups, attributed to female philopatry. However, it is unclear whether this female philopatry is due to geographic regions or social groups, or how this might vary on a worldwide scale. To answer these questions, we combined mtDNA information for 1091 previously published samples with 542 newly obtained DNA profiles (394-bp mtDNA, sex, 13 microsatellites) including the previously unsampled Indian Ocean, and social group information for 541 individuals. We found low mtDNA diversity (π = 0.430%) reflecting an expansion event <80 000 years bp, but strong differentiation by ocean, among regions within some oceans, and among social groups. In comparison, microsatellite differentiation was low at all levels, presumably due to male-mediated gene flow. A hierarchical amova showed that regions were important for explaining mtDNA variance in the Indian Ocean, but not Pacific, with social group sampling in the Atlantic too limited to include in analyses. Social groups were important in partitioning mtDNA and microsatellite variance within both oceans. Therefore, both geographic philopatry and social philopatry influence genetic structure in the sperm whale, but their relative importance differs by sex and ocean, reflecting breeding behaviour, geographic features and perhaps a more recent origin of sperm whales in the Pacific. By investigating the interplay of evolutionary forces operating at different temporal and geographic scales, we show that sperm whales are perhaps a unique example of a worldwide population expansion followed by rapid assortment due to female social

  6. Landscape characteristics influence morphological and genetic differentiation in a widespread raptor (Buteo jamaicensis).

    PubMed

    Hull, Joshua M; Hull, Angus C; Sacks, Benjamin N; Smith, Jeff P; Ernest, Holly B

    2008-02-01

    Landscape-scale population genetic structure in vagile vertebrates was commonly considered to be a contradiction in terms whereas recent studies have demonstrated behaviour and habitat associated structure in several such species. We investigate whether landscape features influence morphological and genetic differentiation in a widespread, mobile raptor. To accurately describe genetic differentiation associated with regional landscape factors, we first investigated subspecies relationships at a continental scale. We used 17 microsatellite loci and five morphological measurements to investigate differentiation between eastern and western subspecies of red-tailed hawks (Buteo jamaicensis) and to identify patterns between differentiation and habitat within western North America. Bayesian and frequency-based analyses of microsatellite data revealed clear distinctions between B. j. borealis (eastern) and B. j. calurus (western) samples. Furthermore, hawks sampled in Texas were stouter than those collected from the Rocky Mountains and farther west. Among western samples, birds from the Great Basin, Rocky Mountains, and Washington were significantly different in morphology than those from Oregon and California. We identified a pattern of isolation by distance among western breeding sites around the Sierra Nevada. Given the long-range dispersal capabilities of raptors, this pattern suggests that population-specific habitat preferences, corresponding with habitat breaks between eastern and western slopes of the Sierra Nevada, and/or regionally variable population densities limit migration between the Mediterranean habitat of central California and the xeric habitats of southern California and interior west. We suggest habitat preferences and regionally disparate population densities may play a role in shaping genetic structure in vagile avian taxa. PMID:18208488

  7. Does genetic distance between parental species influence outcomes of hybridization among coral reef butterflyfishes?

    PubMed

    Montanari, Stefano R; Hobbs, Jean-Paul A; Pratchett, Morgan S; Bay, Line K; Van Herwerden, Lynne

    2014-06-01

    Christmas Island is located at the overlap of the Indian and Pacific Ocean marine provinces and is a hot spot for marine hybridization. Here, we evaluate the ecological framework and genetic consequences of hybridization between butterflyfishes Chaetodon guttatissimus and Chaetodon punctatofasciatus. Further, we compare our current findings to those from a previous study of hybridization between Chaetodon trifasciatus and Chaetodon lunulatus. For both species groups, habitat and dietary overlap between parental species facilitate frequent heterospecific encounters. Low abundance of potential mates promotes heterospecific pair formation and the breakdown of assortative mating. Despite similarities in ecological frameworks, the population genetic signatures of hybridization differ between the species groups. Mitochondrial and nuclear data from C. guttatissimus × C. punctatofasciatus (1% divergence at cyt b) show bidirectional maternal contributions and relatively high levels of introgression, both inside and outside the Christmas Island hybrid zone. In contrast, C. trifasciatus × C. lunulatus (5% cyt b divergence) exhibit unidirectional mitochondrial inheritance and almost no introgression. Back-crossing of hybrid C. guttatissimus × C. punctatofasciatus and parental genotypes may eventually confound species-specific signals within the hybrid zone. In contrast, hybrids of C. trifasciatus and C. lunulatus may coexist with and remain genetically distinct from the parents. Our results, and comparisons with hybridization studies in other reef fish families, indicate that genetic distance between hybridizing species may be a factor influencing outcomes of hybridization in reef fish, which is consistent with predictions from terrestrially derived hybridization theory. PMID:24750170

  8. The crystallinity of calcium phosphate powders influenced by the conditions of neutralized procedure with citric acid additions

    SciTech Connect

    Li Chengfeng

    2009-05-06

    Calcium phosphate powders with nano-sized crystallinity were synthesized by neutralization using calcium hydroxide and orthophosphoric acid with the assistance of citric acid. The influence of processing parameters, such as free or additive citric acid, synthetic temperature and ripening time, on the crystallinity of hydroxyapatite were investigated. The results of X-ray diffraction and microstructure observations showed that the crystallinity and morphology of nano-sized hydroxyapatite particles were influenced by the presence or absence of citric acid. It was found that the crystallinities and crystallite sizes of hydroxyapatite powders prepared with the additive citric acid increased with increasing synthetic temperature and ripening time. Especially, the crystallinities of (h k 0) planes were raised and more homogeneously grown particles were obtained with increasing synthetic temperature.

  9. Removing energy from a beverage influences later food intake more than the same energy addition.

    PubMed

    McCrickerd, K; Salleh, N B; Forde, C G

    2016-10-01

    Designing reduced-calorie foods and beverages without compromising their satiating effect could benefit weight management, assuming that consumers do not compensate for the missing calories at other meals. Though research has demonstrated that compensation for overfeeding is relatively limited, the extent to which energy reductions trigger adjustments in later food intake is less clear. The current study tested satiety responses (characterised by changes in appetite and later food intake) to both a covert 200 kcal reduction and an addition of maltodextrin to a soymilk test beverage. Twenty-nine healthy male participants were recruited to consume three sensory-matched soymilk beverages across four non-consecutive study days: a medium energy control (ME: 300 kcal) and a lower energy (LE: 100 kcal) and higher energy (HE: 500 kcal) version. The ME control was consumed twice to assess individual consistency in responses to this beverage. Participants were unaware of the energy differences across the soymilks. Lunch intake 60 min later increased in response to the LE soymilk, but was unchanged after consuming the HE version. These adjustments accounted for 40% of the energy removed from the soymilk and 13% of the energy added in. Rated appetite was relatively unaffected by the soymilk energy content. No further adjustments were noted for the rest of the day. These data suggest that adult men tested were more sensitive to calorie dilution than calorie addition to a familiar beverage. PMID:27356202

  10. Influence of additives on the structure of surfactant-free microemulsions.

    PubMed

    Marcus, J; Touraud, D; Prévost, S; Diat, O; Zemb, T; Kunz, W

    2015-12-28

    We study the addition of electrolytes to surfactant-free microemulsions in the domain where polydisperse pre-Ouzo aggregates are present. As in previous studies, the microemulsion is the ternary system water/ethanol/1-octanol, where ethanol acts as co-solvent. Addition of electrolytes modifies the static X-ray and neutron scattering, and dynamic light scattering patterns, as well as the position of the miscibility gap, where spontaneous emulsification occurs upon dilution with water. All observations can be rationalized considering that electrolytes are either "salting out" the ethanol, which is the main component of the interface stabilizing the aggregates, or producing charge separation via the antagonistic ion effect discovered by Onuki et al. Amphiphilic electrolytes, such as sodium dodecylsulfate or sodium dietheylhexylphosphate, induce a gradual transition towards monodisperse ionic micelles with their characteristic broad scattering "peak". In these micelles the ethanol plays then the role of a cosurfactant. Dynamic light scattering can only be understood by combination of fluctuations of aggregate concentration due to the vicinity of a critical point and in-out fluctuations of ethanol. PMID:26593697

  11. Influence of crushing and additive irradiation procedures on EPR dosimetry of tooth enamel

    SciTech Connect

    Shalom, S.V.; Chumak, V.V.; Haskell, E.H.; Hayes, R.B.; Kenner, G.H.

    1996-01-01

    The effect of the crushing and additive dose procedures used in EPR dosimetry of enamel was studied on the signals with g-factors of 2. 0045 and g, = 2.0018, g. = 1.9975. Eight fractions, ranging in size from <75 micrometers to 2 mm, were prepared from one tooth. Two cases were investigated: crushing of a non-irradiated sample and of a sample previously irradiated (6 Gy from `Co gamma ray source). In the non-irradiated study, the intensity of the native signal at 2.0045 in by circa 1.75 times as the grain size decreased from maximum to minimum. A small in radiation sensitivity (< 8%) was also observed with decreasing grain size. In the irradiated samples, crushing resulted in slight variations of reconstructed doses from expected values, but the worst possible case (grain sizes < 75 micron) showed that additional errors were less than 10%. The radiation sensitivity of enamel measured immediately after exposure is underestimated. It increases by about 15% in the first month. Based on the decomposition of the observed spectra, a new interpretation of transient signals 1108 is proposed which explains the above phenomena. Recommendations about how to use this interpretation in retrospective EPR dosimetry are given.

  12. Influence of common genetic variation on lung cancer risk: meta-analysis of 14 900 cases and 29 485 controls

    PubMed Central

    Timofeeva, Maria N.; Hung, Rayjean J.; Rafnar, Thorunn; Christiani, David C.; Field, John K.; Bickeböller, Heike; Risch, Angela; McKay, James D.; Wang, Yufei; Dai, Juncheng; Gaborieau, Valerie; McLaughlin, John; Brenner, Darren; Narod, Steven A.; Caporaso, Neil E.; Albanes, Demetrius; Thun, Michael; Eisen, Timothy; Wichmann, H.-Erich; Rosenberger, Albert; Han, Younghun; Chen, Wei; Zhu, Dakai; Spitz, Margaret; Wu, Xifeng; Pande, Mala; Zhao, Yang; Zaridze, David; Szeszenia-Dabrowska, Neonilia; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Mates, Dana; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Krokan, Hans E.; Gabrielsen, Maiken Elvestad; Skorpen, Frank; Vatten, Lars; Njølstad, Inger; Chen, Chu; Goodman, Gary; Lathrop, Mark; Benhamou, Simone; Vooder, Tõnu; Välk, Kristjan; Nelis, Mari; Metspalu, Andres; Raji, Olaide; Chen, Ying; Gosney, John; Liloglou, Triantafillos; Muley, Thomas; Dienemann, Hendrik; Thorleifsson, Gudmar; Shen, Hongbing; Stefansson, Kari; Brennan, Paul; Amos, Christopher I.; Houlston, Richard; Landi, Maria Teresa

    2012-01-01

    Recent genome-wide association studies (GWASs) have identified common genetic variants at 5p15.33, 6p21–6p22 and 15q25.1 associated with lung cancer risk. Several other genetic regions including variants of CHEK2 (22q12), TP53BP1 (15q15) and RAD52 (12p13) have been demonstrated to influence lung cancer risk in candidate- or pathway-based analyses. To identify novel risk variants for lung cancer, we performed a meta-analysis of 16 GWASs, totaling 14 900 cases and 29 485 controls of European descent. Our data provided increased support for previously identified risk loci at 5p15 (P = 7.2 × 10−16), 6p21 (P = 2.3 × 10−14) and 15q25 (P = 2.2 × 10−63). Furthermore, we demonstrated histology-specific effects for 5p15, 6p21 and 12p13 loci but not for the 15q25 region. Subgroup analysis also identified a novel disease locus for squamous cell carcinoma at 9p21 (CDKN2A/p16INK4A/p14ARF/CDKN2B/p15INK4B/ANRIL; rs1333040, P = 3.0 × 10−7) which was replicated in a series of 5415 Han Chinese (P = 0.03; combined analysis, P = 2.3 × 10−8). This large analysis provides additional evidence for the role of inherited genetic susceptibility to lung cancer and insight into biological differences in the development of the different histological types of lung cancer. PMID:22899653

  13. Resting heart rate and the development of antisocial behavior from age 9 to 14: genetic and environmental influences.

    PubMed

    Baker, Laura A; Tuvblad, Catherine; Reynolds, Chandra; Zheng, Mo; Lozano, Dora Isabel; Raine, Adrian

    2009-01-01

    The genetic and environmental basis of a well-replicated association between antisocial behavior (ASB) and resting heart rate was investigated in a longitudinal twin study, based on two measurements between the ages of 9 and 14 years. ASB was defined as a broad continuum of externalizing behavior problems, assessed at each occasion through a composite measure based on parent ratings of trait aggression, delinquent behaviors, and psychopathic traits in their children. Parent ratings of ASB significantly decreased across age from childhood to early adolescence, although latent growth models indicated significant variation and twin similarity in the growth patterns, which were explained almost entirely by genetic influences. Resting heart rate at age 9-10 years old was inversely related to levels of ASB but not change patterns of ASB across age or occasions. Biometrical analyses indicated significant genetic influences on heart rate during childhood, as well as ASB throughout development from age 9 to 14. Both level and slope variation were significantly influenced by genetic factors. Of importance, the low resting heart rate and ASB association was significantly and entirely explained by their genetic covariation, although the heritable component of heart rate explained only a small portion (1-4%) of the substantial genetic variance in ASB. Although the effect size is small, children with low resting heart rate appear to be genetically predisposed toward externalizing behavior problems as early as age 9 years old. PMID:19583891

  14. Genetic and environmental influences on analogical and categorical verbal and spatial reasoning in 12-year old twins.

    PubMed

    Mosing, Miriam A; Mellanby, Jane; Martin, Nicholas G; Wright, Margaret J

    2012-09-01

    Research on the genetic influences on different abstract reasoning skills (fluid intelligence) and their interrelation (especially in childhood/adolescence) has been sparse. A novel cognitive test battery, the Verbal and Spatial Reasoning test for Children (VESPARCH 1), consisting of four matched (in terms of test-procedure and design) subtests assessing verbal [analogical (VA) and categorical (VC)] and spatial [analogical (SA) and categorical (SC)] reasoning, was administered to a population based sample of 12-year old twins (169 pairs). Multivariate analysis was conducted to explore the genetic relationship between the four cognitive sub-domains. Heritabilities were 0.62 (VA), 0.49 (VC), 0.52 (SA), and 0.20 (SC). Genetic influences were due to one common factor with no specific genetic influences. This shared genetic factor also explained almost the entire covariance between the domains, as environmental variance was largely specific to each subtest. The finding of no genetic influences specific to each subtest may be due to the uniquely matched design of the VESPARCH 1, reducing confoundment of different test modalities used in conventional tests. For future research or when interpreting previous studies, our findings highlight the importance of taking such potential artefacts (i.e. different test modalities for different sub-domains) into account when exploring the relationship between cognitive sub-domains. PMID:22552739

  15. Breeding site selection by coho salmon (Oncorhynchus kisutch) in relation to large wood additions and factors that influence reproductive success

    USGS Publications Warehouse

    Clark, Steven M.; Dunham, Jason B.; McEnroe, Jeffery R.; Lightcap, Scott W.

    2014-01-01

    The fitness of female Pacific salmon (Oncorhynchus spp.) with respect to breeding behavior can be partitioned into at least four fitness components: survival to reproduction, competition for breeding sites, success of egg incubation, and suitability of the local environment near breeding sites for early rearing of juveniles. We evaluated the relative influences of habitat features linked to these fitness components with respect to selection of breeding sites by coho salmon (Oncorhynchus kisutch). We also evaluated associations between breeding site selection and additions of large wood, as the latter were introduced into the study system as a means of restoring habitat conditions to benefit coho salmon. We used a model selection approach to organize specific habitat features into groupings reflecting fitness components and influences of large wood. Results of this work suggest that female coho salmon likely select breeding sites based on a wide range of habitat features linked to all four hypothesized fitness components. More specifically, model parameter estimates indicated that breeding site selection was most strongly influenced by proximity to pool-tail crests and deeper water (mean and maximum depths). Linkages between large wood and breeding site selection were less clear. Overall, our findings suggest that breeding site selection by coho salmon is influenced by a suite of fitness components in addition to the egg incubation environment, which has been the emphasis of much work in the past.

  16. Influence of an alloy addition on the physical and clinical behaviour of glass ionomer cement

    NASA Astrophysics Data System (ADS)

    Abour, Mohamed Abour Bashir

    These in vitro studies compared the various properties of an experimental high powder liquid content glass ionomer cement (EXPT) with those of a metal addition GIC (Hi-Dense) and disperse phase amalgam (Dispersalloy). Bi-axial, four point flexural and compressive tests were used to evaluate strength. Six groups of ten specimens were constructed for each test for each material and allowed to set in an oven at 37°C for 60 minutes. Specimens were stored in distilled water at 37°C until testing at one day, one week, one, three, six months and year. It was found that the strength of Hi-Dense increased and then maintained over extended time, whereas the strength of EXPT showed a declined at 3 months. The bond strengths of the materials to both enamel and dentine were also evaluated. Ten groups of ten teeth, five for each surface for each glass ionomer materials, were prepared. Teeth were aligned leaving the enamel and dentine surfaces exposed. The mixed material was condensed into a cylinder placed on the appropriate surface. These specimens were also stored in distilled water at 37°C. It was found that Hi-Dense had a higher bond strength to enamel that increased with time. The bond strength to dentine was maintained over the test period. The erosion rate of the materials was evaluated using the lactic acid erosion test. Three groups of six specimens for each material were constructed and tested after one hour, one day and at six months. Each specimen was subjected to an impinging jet of lactic acid solution. The erosion rate was determined by weight loss and dimensional change. It was found that Hi-Dense had a high erosion resistance which was slightly better than the experimental material. The microleakage, around restorations prepared, using the glass ionomer materials, was evaluated after cyclical loading the restoration-tooth complex. It was found that there was less leakage around Hi-Dense than EXPT at both the cervical and occlusal margins. In a clinical

  17. Influence of biochar addition on the humic substances of composting manures.

    PubMed

    Jindo, Keiji; Sonoki, Tomonori; Matsumoto, Kazuhiro; Canellas, Luciano; Roig, Asunción; Sanchez-Monedero, Miguel A

    2016-03-01

    Application of biochar (10% v/v) to a manure composting matrix was investigated to evaluate its effect on the chemical composition of humic substances during the composting process. The characteristics of the humic acid (HA) and fulvic acid (FA) fractions were analyzed in compost mixtures originating from two different manures (poultry manure (PM) and cow manure (CM)). The C contents of HA and FA from the manure compost/biochar blends (PM+B and CM+B) were higher than those from PM and CM, with an enhanced recalcitrant fraction, as determined by thermogravimetric analysis. Spectroscopic analysis showed that enrichment of aromatic-C and carboxylic-C occurred in the FA fractions of PM+B and CM+B to a greater extent than in PM and CM. Biochar addition into the composting mixture improved the final compost quality, especially for the light humified fraction (FA). PMID:26786401

  18. Influence of Radiation and Multivalent Cation Additions on Phase Separation and Crystallization of Glass

    SciTech Connect

    Michael C. Weinberg; Donald R. Uhlmann; Gary L. Smith

    2002-08-09

    This report presents results of: (1) measurement of valence state ratios of iron in glass, and (2) a study of the effect of iron redox ratio on phase separation behavior in a glass. The redox ratio of iron in two sodium silicate (NS) glasses has been determined using a colorimetric method, Moessbauer analysis, and optical absorption. The experimental procedures were described in a previous report. We found that these three methods gave excellent agreement for the values of the Fe++/Fe+++ (redox ratio) in the glasses. Also, using the results of the colorimetric analysis we were able to find the extinction coefficients for the18.56% NS and the 13% NS glasses. We have utilized the optical absorption data that was taken for purposes of determining redox ratios to provide glass structural information. In particular, it has been suggested that the band centered near 14,500 cm-1 is indicative of Fe2+ - O2- - Fe3+ formation. In addition, the relative band intensities at 10,000 cm-1 and 4,800 cm-1 could give us information as to the environment around the Fe2+ responsible for the 4,800 cm-1 band. The Moessbauer data will provide supporting structural information. For example, the relative number of clustered and free ferric ions can be computed from the ratio of areas under the doublet and sextet in the liquid He spectra. Also, the change in shift parameter with redox ratio will provide an indication of whether there is an increase or decrease in tetrahedral site symmetry about both ferrous and ferric ions. Finally, the quadrupole splitting parameter provides information regarding the site symmetries about the Fe++ and Fe+++. Currently, we are analyzing the spectral data for these purposes. The Moessbauer work was done in conjunction with colleagues at PNNL, and a manuscript is currently in preparation. The effect of oxidation state of iron on the phase separation of xNa2O {center_dot}(100-x)SiO2 glasses, x = 18.56 and 13, containing 0.5 mole % iron oxide was studied. The

  19. Stability of gabexate mesilate products: Influence of the addition of mannitol.

    PubMed

    Sakurai, Miyuki; Abe, Hiroyuki; Okamura, Noboru; Inoue, Yohei; Akiyoshi, Takeshi; Matsuyama, Kenji; Uchida, Takahiro; Otsuka, Makoto

    2010-01-01

    Gabexate mesilate is a non-peptide protease inhibitor, developed in Japan, which is used in the treatment of acute pancreatitis and disseminated intravascular coagulation. This compound is readily hydrolyzed as it has ester bonds in its structure. It is now out of patent in Japan and there are many generic versions on the market. The crystal structure and the hydrolysate content of the branded product and nine generic versions were evaluated by X-ray diffractometry, thermal analysis and HPLC. The results showed that generic products containing mannitol as an additive had a higher content of hydrolysate as an impurity than the branded product or generic products formulated without mannitol, suggesting that the crystal structure might be altered and stability impaired in mannitol-containing drug products. PMID:20448300

  20. Influence of alumina coating on transport and recombination in DSSCs with 1-methylbenzidazole as electrolyte additives

    NASA Astrophysics Data System (ADS)

    Xu, Xueqing; Barea, Eva Maria; Fabregat-Santiago, Francisco; Bisquert, Juan; Xu, Gang

    2009-08-01

    Nanocrystalline TiO2 electrodes have been coated with alumina by being immersed into the solutions of aluminum isopropoxide and aluminum acetylacetonate respectively. The current-voltage characteristics of the TiO2 and TiO2/Al2O3 electrodes with 1-methylbenzimidazole (MBI) as additives in the electrolytes have been detected. It is found that the TiO2/Al2O3 electrodes immersed in the solutions of aluminum isopropoxide (acetylacetone as coordinate ligands) for 1 hour have obtained great increase of Jsc, and owned the improved cells efficiency by 17%. To discover the origins of this improved photovoltaic performance and investigate the electron properties of the cells, the electrochemical impedance spectroscopy (EIS) has been used both in the dark and under illumination at different applied potentials. It is proposed that with the coating of Al2O3, the adsorption of MBI cations at the surface of TiO2 electrodes decreased with the decrease of the applied potentials, which resulted in the downwards shift of the conduction band position of the TiO2/Al2O3 electrodes at the lower potentials. As a result, the charge transfer resistance Rct decreased, and chemical capacitance Cfilms increased. Under illumination, the decrease of Rct became smaller and the conductivities became larger, which was attributed to the recombination inhibition effect of Al2O3 coating to the photoinjected electrons. As a consequence, the electron lifetime and the effective diffusion length for the TiO2/Al2O3 electrodes increased, leading to the great increase of Jsc. It is indicated that with the coating of Al2O3, the decrease of Jsc could be overcome when MBI is used as the additives of the electrolyte.

  1. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    PubMed

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-06-01

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm). PMID:27219645

  2. 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

  3. Fretting Wear Properties of TiCN-Ni Cermets: Influence of Load and Secondary Carbide Addition

    NASA Astrophysics Data System (ADS)

    Manoj Kumar, B. V.; Basu, Bikramjit

    2008-03-01

    The increasing demand for TiCN-based cermets in tribological applications necessitates a thorough understanding of the influence of experimental as well as material parameters on the friction and wear properties. In optimizing microstructure and properties, secondary carbides are added to baseline TiCN-Ni cermet. The present work aims at evaluating the fretting wear behavior of Ti(CN)-Ni cermets containing various secondary carbides, such as WC, NbC, TaC, and HfC, against steel at different loading (2, 6, and 10 N) conditions. The evolution of tangential frictional force for the investigated cermets was analyzed in terms of fretting logs and fretting loops. The topographical characterization of worn surfaces was performed, using laser surface profilometry and a scanning electron microscope (SEM) equipped with energy-dispersive spectroscopy (EDS) capability. The steady-state coefficient of friction (COF) was minimum (0.33) for a TiCN-20Ni cermet/steel tribocouple, while a maximum COF (0.47) was recorded for TiCN-20Ni-10HfC cermet/steel at a 2-N load. The wear rate of the cermets varied in the range of 1.7 × 10-6 to 3.5 × 10-6 mm3/Nm. The TiCN-20Ni-10HfC cermet exhibited poor wear resistance among investigated cermets. The dominant wear mechanisms were found as abrasion and tribolayer formation. The dominance of abrasion is explained in terms of cumulative energy dissipation.

  4. Influence of antimicrobial feed additives on broiler commensal posthatch gut microbiota development and performance.

    PubMed

    Torok, Valeria A; Allison, Gwen E; Percy, Nigel J; Ophel-Keller, Kathy; Hughes, Robert J

    2011-05-01

    The effects of avilamycin, zinc bacitracin, and flavophospholipol on broiler gut microbial community colonization and bird performance in the first 17 days posthatch were investigated. Significant differences in gut microbiota associated with gut section, dietary treatment, and age were identified by terminal restriction fragment length polymorphism (T-RFLP), although no performance-related differences between dietary treatments were detected. Similar age-related shifts in the gut microbiota were identified regardless of diet but varied between the ilea and ceca. Interbird variabilities in ileal bacterial communities were reduced (3 to 7 days posthatch) in chicks fed with feed containing antimicrobial agents. Avilamycin and flavophospholipol had the most consistent effect on gut microbial communities. Operational taxonomic units (OTU) linked to changes in gut microbiota in birds on antimicrobial-supplemented diets were characterized and identified. Some OTUs could be identified to the species level; however, the majority could be only tentatively classified to the genus, family, order, or domain level. OTUs 140 to 146 (Lachnospiraceae), OTU 186/188 (Lactobacillus johnsonii), OTU 220 (Lachnospiraceae), OTUs 284 to 288 (unclassified bacterial spp. or Ruminococcaceae), OTU 296/298 (unclassified bacterium or Clostridiales), and OTU 480/482 (Oxalobacteraceae) were less prevalent in the guts of chicks fed antimicrobial-supplemented diets. OTU 178/180 (Lactobacillus crispatus), OTU 152 (Lactobacillus reuteri or unclassified Clostridiales), OTU 198/200 (Subdoligranulum spp.), and OTU 490/492 (unclassified bacterium or Enterobacteriaceae) were less prevalent in the gut of chicks raised on the antimicrobial-free diet. The identification of key bacterial species influenced by antimicrobial-supplemented feed immediately posthatch may assist in the formulation of diets that facilitate beneficial gut microbial colonization and, hence, the development of alternatives to current

  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. Marker-assisted dissection of genetic influences on motor and neuroendocrine sensitization to cocaine in rats.

    PubMed

    Vendruscolo, L F; Vendruscolo, J C M; Terenina, E; Ramos, A; Takahashi, R N; Mormède, P

    2009-04-01

    This study investigated genetic influences on behavioral and neuroendocrine responses to cocaine sensitization. We used male and female rats of the inbred strains Lewis (LEW) and spontaneously hypertensive rats (SHR), which display genetic differences in stress-related responses. The influence of two quantitative trait loci (QTL; Ofil1 and Ofil2 on chromosomes 4 and 7), which modulate stress reactivity in rats, on the effects of cocaine was also investigated through the use of recombinant lines (derived from a LEW x SHR intercross) selected by their genotype at Ofil1 and Ofil2. Animals were given repeated cocaine or saline injections and tested for locomotion (induction of sensitization). Two weeks later, all animals were challenged with cocaine, and locomotion and corticosterone levels were measured (expression of sensitization). Results indicated that male SHR rats showed more behavioral sensitization than LEW rats, whereas no strain differences in sensitization were seen among females. When challenged with cocaine, LEW and SHR rats of both sexes pretreated with cocaine showed behavioral sensitization compared with saline pretreated animals; however, only LEW rats displayed an increase in the corticosterone levels. Ofil1 was found to influence the induction of sensitization in males and Ofil2 modulated the locomotor effect of cocaine in females. This study provides evidence of a genotype-dependent relationship between the induction and expression of cocaine sensitization, and between the behavioral and neuroendocrine responses induced by cocaine. Moreover, the Ofil1 and Ofil2 loci may contain one or more genes that control the behavioral effects of cocaine in rats. PMID:19077120

  8. Influence of attrition scrubbing, ultrasonic treatment, and oxidant additions on uranium removal from contaminated soils

    SciTech Connect

    Timpson, M.E.; Elless, M.P.; Francis, C.W.

    1994-06-01

    As part of the Uranium in Soils Integrated Demonstration Project being conducted by the US Department of Energy, bench-scale investigations of selective leaching of uranium from soils at the Fernald Environmental Management Project site in Ohio were conducted at Oak Ridge National Laboratory. Two soils (storage pad soil and incinerator soil), representing the major contaminant sources at the site, were extracted using carbonate- and citric acid-based lixiviants. Physical and chemical processes were used in combination with the two extractants to increase the rate of uranium release from these soils. Attrition scrubbing and ultrasonic dispersion were the two physical processes utilized. Potassium permanganate was used as an oxidizing agent to transform tetravalent uranium to the hexavalent state. Hexavalent uranium is easily complexed in solution by the carbonate radical. Attrition scrubbing increased the rate of uranium release from both soils when compared with rotary shaking. At equivalent extraction times and solids loadings, however, attrition scrubbing proved effective only on the incinerator soil. Ultrasonic treatments on the incinerator soil removed 71% of the uranium contamination in a single extraction. Multiple extractions of the same sample removed up to 90% of the uranium. Additions of potassium permanganate to the carbonate extractant resulted in significant changes in the extractability of uranium from the incinerator soil but had no effect on the storage pad soil.

  9. Influence of dry mixing and distribution of conductive additives in cathodes for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Bauer, Werner; Nötzel, Dorit; Wenzel, Valentin; Nirschl, Hermann

    2015-08-01

    Conductive additives, like carbon black or graphite, are essential components of lithium ion batteries due to the limited electrical conductivity of most electrode materials. However, there is still a lack of knowledge about the optimized distribution of these materials within the electrode. A dry mixing process is used in order to prepare a conductive coating by depositing carbon black on the surface of Li(Ni1/3Mn1/3Co1/3)O2 (NMC) cathode particles. It is demonstrated that this - from a theoretically point of view - favorable distribution does not allow the preparation of working electrodes without taking into account the role of the binder. After adding an organic binder to the slurry, the polymer deposits on top of the carbon shell during drying and inhibits the conductive contact between the particles. This can be avoided by a fraction of distributed carbon particles which are associated with the binder phase providing conductive paths through the isolating organic material. It is shown that carbon black and graphite are principally fulfilling this task, but both materials are leading to varying processing behavior and electrode properties.

  10. Influence of Lithium Additives in Small Molecule Light-Emitting Electrochemical Cells.

    PubMed

    Lin, Kuo-Yao; Bastatas, Lyndon D; Suhr, Kristin J; Moore, Matthew D; Holliday, Bradley J; Minary-Jolandan, Majid; Slinker, Jason D

    2016-07-01

    Light-emitting electrochemical cells (LEECs) utilizing small molecule emitters such as iridium complexes have great potential as low-cost emissive devices. In these devices, ions rearrange during operation to facilitate carrier injection, bringing about efficient operation from simple, single layer devices. Recent work has shown that the luminance, efficiency, and responsiveness of iridium-based LEECs are greatly enhanced by the inclusion of small amounts of lithium salts (≤0.5%/wt) into the active layer. However, the origin of this enhancement has yet to be demonstrated experimentally. Furthermore, although iridium-based devices have been the longstanding leader among small molecule LEECs, fundamental understanding of the ionic distribution in these devices under operation is lacking. Herein, we use scanning Kelvin probe microscopy to measure the in situ potential profiles and electric field distributions of planar iridium-based LEECs and clarify the role of ionic lithium additives. In pristine devices, it is found that ions do not pack densely at the cathode, and ionic redistribution is slow. Inclusion of small amounts of Li[PF6] greatly increases ionic space charge near the cathode that doubles the peak electric fields and enhances electronic injection relative to pristine devices. This study confirms and clarifies a number of longstanding hypotheses regarding iridium LEECs and recent postulates concerning optimization of their operation. PMID:27299981

  11. Influence of the heterogeneous reaction HCL + HOCl on an ozone hole model with hydrocarbon additions

    SciTech Connect

    Elliott, S.; Cicerone, R.J.; Turco, R.P.

    1994-02-20

    Injection of ethane or propane has been suggested as a means for reducing ozone loss within the Antarctic vortex because alkanes can convert active chlorine radicals into hydrochloric acid. In kinetic models of vortex chemistry including as heterogeneous processes only the hydrolysis and HCl reactions of ClONO{sub 2} and N{sub 2}O{sub 5}, parts per billion by volume levels of the light alkanes counteract ozone depletion by sequestering chlorine atoms. Introduction of the surface reaction of HCl with HOCl causes ethane to deepen baseline ozone holes and generally works to impede any mitigation by hydrocarbons. The increased depletion occurs because HCl + HOCl can be driven by HO{sub x} radicals released during organic oxidation. Following initial hydrogen abstraction by chlorine, alkane breakdown leads to a net hydrochloric acid activation as the remaining hydrogen atoms enter the photochemical system. Lowering the rate constant for reactions of organic peroxy radicals with ClO to 10{sup {minus}13} cm{sup 3} molecule{sup {minus}1} s{sup {minus}1} does not alter results, and the major conclusions are insensitive to the timing of the ethane additions. Ignoring the organic peroxy radical plus ClO reactions entirely restores remediation capabilities by allowing HO{sub x} removal independent of HCl. Remediation also returns if early evaporation of polar stratospheric clouds leaves hydrogen atoms trapped in aldehyde intermediates, but real ozone losses are small in such cases. 95 refs., 4 figs., 7 tabs.

  12. Influence of propane additives on the detonation characteristics of H2-air mixtures

    NASA Astrophysics Data System (ADS)

    Cheng, Guanbing; Bauer, Pascal; Zitoun, Ratiba

    2014-03-01

    Hydrogen is more and more considered as a potential fuel for propulsion applications. However, due to its low ignition energy and wide flammability limits, H2-air mixtures raise a concern in terms of safety. This aspect can be partly solved by adding an alkane to these mixtures, which plays the role of an inhibitor. The present paper provides data on such binary fuel-air mixtures where various amounts of propane are added to hydrogen. The behavior of the corresponding mixtures, in terms of detonation characteristics and other fundamental properties, such as the cell size of the detonation front and induction delay, are presented and discussed for a series of equivalence ratios and propane addition. The experimental detonation velocity is in good agreement with calculated theoretical Chapman-Jouguet values. Based on soot tracks records, the cell size λ is measured, whereas the induction length L i is derived from data using a GRI-Mech kinetic mechanism. These data allow providing a value of the coefficient K = λ/L i .

  13. Influencing the structure of block copolymer micelles with small molecule additives

    NASA Astrophysics Data System (ADS)

    Robertson, Megan; Singh, Avantika; Cooksey, Tyler; Kidd, Bryce; Piemonte, Rachele; Wang, Shu; Mai Le, Kim; Madsen, Louis

    Amphiphilic block copolymer micelles in water are under broad exploration for drug delivery applications due to their high loading capacity and targeted drug delivery. We aim to understand the kinetic and thermodynamic processes that underlie the self-assembly of diblock copolymer micelle systems. The present work focuses on diblock copolymers containing poly(ethylene oxide) (a hydrophilic polymer) and polycaprolactone (a hydrophobic polymer), which spontaneously self-assemble into spherical micelles in water. Addition of a common good solvent (a co-solvent) for both of the constituting blocks, such as tetrahydrofuran (THF), reduces the interfacial tension at the core-corona interface. We are currently investigating the effect of this phenomenon on the micelle structural properties, using small-angle scattering and nuclear magnetic resonance. We have characterized the hydrodynamic radius, core radius, corona thickness, aggregation number, degree of swelling of the micelle core with the co-solvent, and unimer (free chain) concentration, as a function of the co-solvent concentration. Fundamental knowledge from these studies will inform design of drug delivery systems by allowing us to tailor micelle properties for optimal cargo loading.

  14. Influence of the addition of rosemary essential oil on the volatiles pattern of porcine frankfurters.

    PubMed

    Estévez, Mario; Ventanas, Sonia; Ramírez, Rosario; Cava, Ramón

    2005-10-19

    The effect of the addition of increasing levels of rosemary essential oil (150, 300, and 600 mg/kg) on the generation of volatile compounds in frankfurters from Iberian and white pigs was analyzed using solid-phase microextraction coupled to gas chromatography and mass spectrometry (SPME-GC-MS). Lipid-derived volatiles such as aldehydes (hexanal, octanal, nonanal) and alcohols (pentan-1-ol, hexan-1-ol, oct-1-en-3-ol) were the most abundant compounds in the headspace (HS) of porcine frankfurters. Frankfurters from different pig breeds presented different volatile profiles due to their different oxidation susceptibilities as a likely result of their fatty acid composition and vitamin E content. Rosemary essential oil showed a different effect on the generation of volatiles depending on the type of frankfurter in which they were added. In frankfurters from Iberian pigs, the antioxidant effect of the essential oil improved with increasing levels, showing the highest activity at 600 mg/kg. In contrast, 150 mg/kg of the essential oil improved the oxidative stability of frankfurters from white pigs, whereas higher levels led to no effect or a prooxidant effect. The activity of the essential oil could have been affected by the different fatty acid compositions and vitamin E contents between types of frankfurters. SPME successfully allowed the isolation and analysis of volatile terpenes from frankfurters with added rosemary essential oil including alpha-pinene, beta-myrcene, l-limonene, (E)-caryophyllene, linalool, camphor, and 1,8-cineole, which might contribute to the aroma characteristics of frankfurters. PMID:16218682

  15. Nanoclay addition to a conventional glass ionomer cements: Influence on physical properties

    PubMed Central

    Fareed, Muhammad A.; Stamboulis, Artemis

    2014-01-01

    Objective: The objective of the present study is to investigate the reinforcement effect of polymer-grade montmorillonite (PGN nanoclay) on physical properties of glass ionomer cement (GIC). Materials and Methods: The PGN nanoclay was dispersed in the liquid portion of GIC (HiFi, Advanced Healthcare, Kent, UK) at 1%, 2% and 4% (w/w). Fourier-transform infrared (FTIR) spectroscopy was used to quantify the polymer liquid of GICs after dispersion of nanoclay. The molecular weight (Mw) of HiFi liquid was determined by gel permeation chromatography. The compressive strength (CS), diametral-tensile strength, flexural strength (FS) and flexural modulus (Ef) of cements (n = 20) were measured after storage for 1 day, 1 week and 1 month. Fractured surface was analyzed by scanning electron microscopy. The working and setting time (WT and ST) of cements was measured by a modified Wilson's rheometer. Results: The FTIR results showed a new peak at 1041 cm−1 which increased in intensity with an increase in the nanoclay content and was related to the Si-O stretching mode in PGN nanoclay. The Mw of poly (acrylic acid) used to form cement was in the range of 53,000 g/mol. The nanoclay reinforced GICs containing <2% nanoclays exhibited higher CS and FS. The Ef cement with 1% nanoclays was significantly higher. The WT and ST of 1% nanoclay reinforced cement were similar to the control cement but were reduced with 2% and 4% nanoclay addition. Conclusion: The dispersion of nanoclays in GICs was achieved, and GIC containing 2 wt% nanoclay is a promising restorative materials with improved physical properties. PMID:25512724

  16. Nature and nurture: environmental influences on a genetic rat model of depression.

    PubMed

    Mehta-Raghavan, N S; Wert, S L; Morley, C; Graf, E N; Redei, E E

    2016-01-01

    In this study, we sought to learn whether adverse events such as chronic restraint stress (CRS), or 'nurture' in the form of environmental enrichment (EE), could modify depression-like behavior and blood biomarker transcript levels in a genetic rat model of depression. The Wistar Kyoto More Immobile (WMI) is a genetic model of depression that aided in the identification of blood transcriptomic markers, which successfully distinguished adolescent and adult subjects with major depressive disorders from their matched no-disorder controls. Here, we followed the effects of CRS and EE in adult male WMIs and their genetically similar control strain, the Wistar Kyoto Less Immobile (WLI), that does not show depression-like behavior, by measuring the levels of these transcripts in the blood and hippocampus. In WLIs, increased depression-like behavior and transcriptomic changes were present in response to CRS, but in WMIs no behavioral or additive transcriptomic changes occurred. Environmental enrichment decreased both the inherent depression-like behavior in the WMIs and the behavioral difference between WMIs and WLIs, but did not reverse basal transcript level differences between the strains. The inverse behavioral change induced by CRS and EE in the WLIs did not result in parallel inverse expression changes of the transcriptomic markers, suggesting that these behavioral responses to the environment work via separate molecular pathways. In contrast, 'trait' transcriptomic markers with expression differences inherent and unchanging between the strains regardless of the environment suggest that in our model, environmental and genetic etiologies of depression work through independent molecular mechanisms. PMID:27023176

  17. Genetic Based Plant Resistance and Susceptibility Traits to Herbivory Influence Needle and Root Litter Nutrient Dynamics

    SciTech Connect

    Classen, Aimee T; Chapman, Samantha K.; Whitham, Thomas G; Hart, Stephen C; Koch, George W

    2007-01-01

    It is generally assumed that leaf and root litter decomposition have similar drivers and that nutrient release from these substrates is synchronized. Few studies have examined these assumptions, and none has examined how plant genetics (i.e., plant susceptibility to herbivory) could affect these relationships. Here we examine the effects of herbivore susceptibility and resistance on needle and fine root litter decomposition of pi on pine, Pinus edulis. The study population consists of individual trees that are either susceptible or resistant to herbivory by the pi on needle scale, Matsucoccus acalyptus, or the stem-boring moth, Dioryctria albovittella. Genetic analyses and experimental removals and additions of these insects have identified trees that are naturally resistant and susceptible to these insects. These herbivores increase the chemical quality of litter inputs and alter soil microclimate, both of which are important decomposition drivers. Our research leads to four major conclusions: Herbivore susceptibility and resistance effects on 1) needle litter mass loss and phosphorus (P) retention in moth susceptible and resistant litter are governed by microclimate, 2) root litter nitrogen (N) and P retention, and needle litter N retention are governed by litter chemical quality, 3) net nutrient release from litter can reverse over time, 4) root and needle litter mass loss and nutrient release are determined by location (above- vs. belowground), suggesting that the regulators of needle and root decomposition differ at the local scale. Understanding of decomposition and nutrient retention in ecosystems requires consideration of herbivore effects on above- and belowground processes and how these effects may be governed by plant genotype. Because an underlying genetic component to herbivory is common to most ecosystems of the world and herbivory may increase in climatic change scenarios, it is important to evaluate the role of plant genetics in affecting carbon and

  18. Nature and nurture: environmental influences on a genetic rat model of depression

    PubMed Central

    Mehta-Raghavan, N S; Wert, S L; Morley, C; Graf, E N; Redei, E E

    2016-01-01

    In this study, we sought to learn whether adverse events such as chronic restraint stress (CRS), or ‘nurture' in the form of environmental enrichment (EE), could modify depression-like behavior and blood biomarker transcript levels in a genetic rat model of depression. The Wistar Kyoto More Immobile (WMI) is a genetic model of depression that aided in the identification of blood transcriptomic markers, which successfully distinguished adolescent and adult subjects with major depressive disorders from their matched no-disorder controls. Here, we followed the effects of CRS and EE in adult male WMIs and their genetically similar control strain, the Wistar Kyoto Less Immobile (WLI), that does not show depression-like behavior, by measuring the levels of these transcripts in the blood and hippocampus. In WLIs, increased depression-like behavior and transcriptomic changes were present in response to CRS, but in WMIs no behavioral or additive transcriptomic changes occurred. Environmental enrichment decreased both the inherent depression-like behavior in the WMIs and the behavioral difference between WMIs and WLIs, but did not reverse basal transcript level differences between the strains. The inverse behavioral change induced by CRS and EE in the WLIs did not result in parallel inverse expression changes of the transcriptomic markers, suggesting that these behavioral responses to the environment work via separate molecular pathways. In contrast, ‘trait' transcriptomic markers with expression differences inherent and unchanging between the strains regardless of the environment suggest that in our model, environmental and genetic etiologies of depression work through independent molecular mechanisms. PMID:27023176

  19. Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil.

    PubMed

    Forjaz, C L M; Bartholomeu, T; Rezende, J A S; Oliveira, J A; Basso, L; Tani, G; Prista, A; Maia, J A R

    2012-12-01

    Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h²), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h² = 0.37 ± 0.10, P < 0.05; diastolic BP: h² = 0.39 ± 0.09, P < 0.05; TPA: h² = 0.24 ± 0.09, P < 0.05). Significant genetic (r g) and environmental (r e) correlations were detected between systolic and diastolic BP (r g = 0.67 ± 0.12 and r e = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (r e = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences. PMID:22948378

  20. Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

    PubMed Central

    Forjaz, C.L.M.; Bartholomeu, T.; Rezende, J.A.S.; Oliveira, J.A.; Basso, L.; Tani, G.; Prista, A.; Maia, J.A.R.

    2012-01-01

    Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h2), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h2 = 0.37 ± 0.10, P < 0.05; diastolic BP: h2 = 0.39 ± 0.09, P < 0.05; TPA: h2 = 0.24 ± 0.09, P < 0.05). Significant genetic (rg) and environmental (re) correlations were detected between systolic and diastolic BP (rg = 0.67 ± 0.12 and re = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (re = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences. PMID:22948378

  1. The influence of polyaspartate additive on the growth and morphology of calcium carbonate crystals

    NASA Astrophysics Data System (ADS)

    Gower, Laurie Anne

    The addition of low levels of polyaspartate to a supersaturated calcium carbonate (CaCOsb3) solution leads to unusual morphologies in the inorganic phase. Spherulitic vaterite aggregates with helical protrusions, and distorted calcite crystals that contain spiral pits, have been produced. The helical particles are coated with an inorganic membrane that appears to be responsible for the helical twist. The polymer also causes deposition of thin CaCOsb3 tablets and films on the glass substrate. Two distinct types of films are deposited; the first is a mosaic of calcite crystals, and the second is spherulitic vaterite. In situ observations of the crystallization reaction have determined that the thin-film morphology is a result of the phase separation of a hydrated CaCOsb3/polymer liquid-precursor, whereby accumulation of isotropic droplets creates a coating on the substrate, and subsequent dehydration and crystallization yields birefringent CaCOsb3 films. During the amorphous to crystalline transition, incremental growth steps lead to "transition bars" and sectored calcite tablets. This in vitro system was originally modeled after certain aspects of CaCOsb3 biomineralization, in which the soluble proteins extracted from biominerals tend to have high levels of aspartic acid residues. Based on the similarities between features exhibited by the products of this system and those in biominerals, an argument has been presented to suggest that this polymer-induced liquid-precursor (PILP) process is involved in the morphogenesis of CaCOsb3 biominerals. These features include the following: thin CaCOsb3 tablets that grow laterally; tablets that express unstable crystallographic faces; non-faceted single crystals with curved surfaces; spatially-delineated single crystals; sectored calcite tablets; hollow-shell spheres; calcium carbonate cements; and magnesium-bearing calcites. This work has demonstrated that a means of morphological control can be accomplished through non

  2. 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 ...

  3. 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...

  4. Influence of salt additives on phase transformation of guanosine 5-monophosphate disodium in anti-solvent crystallization

    NASA Astrophysics Data System (ADS)

    Nguyen, Anh-Tuan; Kang, Jeongki; Kim, Woo-Sik

    2013-06-01

    The influence of sodium chloride (NaCl) as an additive on the anti-solvent crystallization of guanosine 5-monophosphate disodium (GMP-2Na) was investigated in continuous Couette-Taylor (CT) and batch mixing tank (MT) crystallizers. The anti-solvent crystallization initially precipitated amorphous solids of GMP-2Na, which then slowly transformed into hydrate crystals in the solution. However, the phase transformation of GMP-2Na was markedly promoted by the sodium chloride additive due to the common ion effect. While the normal phase transformation in the batch MT crystallizer required over 120 min of crystallization time without using the sodium chloride additive, the process was completed within 60 min when a small amount of the salt additive was added. The phase transformation was also significantly accelerated in the continuous CT crystallizer. Without using the sodium chloride additive, 7 min of the mean residence time was required for the production of 100% hydrate GMP crystals. However, when using the sodium chloride additive, a mean residence time of only 2 min was sufficient to completely transform the amorphous solids of GMP-2Na into hydrate crystals due to the common ion effect combined with the effective fluid motion of the Taylor vortex for the mass transfer.

  5. 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

  6. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence.

    PubMed

    Krapohl, Eva; Rimfeld, Kaili; Shakeshaft, Nicholas G; Trzaskowski, Maciej; McMillan, Andrew; Pingault, Jean-Baptiste; Asbury, Kathryn; Harlaar, Nicole; Kovas, Yulia; Dale, Philip S; Plomin, Robert

    2014-10-21

    Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35-58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. PMID:25288728

  7. Characterization of red-legged partridge (Alectoris rufa) sperm: Seasonal changes and influence of genetic purity.

    PubMed

    Santiago-Moreno, J; Castaño, C; Toledano-Díaz, A; Esteso, M C; López-Sebastián, A; Gañán, N; Hierro, M J; Marchal, F; Campo, J L; Blesbois, E

    2015-01-01

    The general decline in wild Iberian populations of the red-legged partridge (Alectoris rufa) has been accompanied by an increase in game-farm facilities producing hybrids with chukar partridges (Alectoris chukar). Genetic introgression from chukar partridges is thought to modify male red-legged partridge reproductive indicators. The aim of the present study was to determine the effects of such genetic introgression on seasonal reproductive patterns by comparing the sperm and plasma testosterone concentrations of males from pure red-legged and hybrid red-legged/chukar populations. Semen was collected twice monthly over a 12-mo period using a massage technique. Both types of bird showed a clear seasonal pattern of spermatogenic activity. The proportion of males ejaculating sperm was higher (P<0.05) among the pure red-legged birds. The greatest sperm production was recorded in March to May among the pure birds and April to May among the hybrids. Reproductive activity in both groups decreased in June, to reach a minimum in August to December among the hybrids and in September to December among the pure birds. Spermatogenic activity resumed in January in both groups. The sperm concentration produced by the pure birds was smaller than that of the hybrids (P<0.001), but the percentage of motile sperm was higher in the pure birds (P<0.001). The sperm of the hybrids showed greater straight-line velocity (P<0.05), linearity (P<0.001), straightness (P<0.001), sperm wobble (P<0.05), and beat-cross frequency values (P<0.001). The length and area of the sperm head were smaller in the pure birds (P<0.05). The seasonal plasma testosterone concentration pattern followed a trend roughly parallel to the ejaculatory response. The present results suggest that genetic introgression influences the reproductive variables of the red-legged partridge. PMID:25577796

  8. The high heritability of educational achievement reflects many genetically influenced traits, not just intelligence

    PubMed Central

    Krapohl, Eva; Rimfeld, Kaili; Shakeshaft, Nicholas G.; Trzaskowski, Maciej; McMillan, Andrew; Pingault, Jean-Baptiste; Asbury, Kathryn; Harlaar, Nicole; Kovas, Yulia; Dale, Philip S.; Plomin, Robert

    2014-01-01

    Because educational achievement at the end of compulsory schooling represents a major tipping point in life, understanding its causes and correlates is important for individual children, their families, and society. Here we identify the general ingredients of educational achievement using a multivariate design that goes beyond intelligence to consider a wide range of predictors, such as self-efficacy, personality, and behavior problems, to assess their independent and joint contributions to educational achievement. We use a genetically sensitive design to address the question of why educational achievement is so highly heritable. We focus on the results of a United Kingdom-wide examination, the General Certificate of Secondary Education (GCSE), which is administered at the end of compulsory education at age 16. GCSE scores were obtained for 13,306 twins at age 16, whom we also assessed contemporaneously on 83 scales that were condensed to nine broad psychological domains, including intelligence, self-efficacy, personality, well-being, and behavior problems. The mean of GCSE core subjects (English, mathematics, science) is more heritable (62%) than the nine predictor domains (35–58%). Each of the domains correlates significantly with GCSE results, and these correlations are largely mediated genetically. The main finding is that, although intelligence accounts for more of the heritability of GCSE than any other single domain, the other domains collectively account for about as much GCSE heritability as intelligence. Together with intelligence, these domains account for 75% of the heritability of GCSE. We conclude that the high heritability of educational achievement reflects many genetically influenced traits, not just intelligence. PMID:25288728

  9. Neuropathic pain as part of chronic widespread pain: environmental and genetic influences

    PubMed Central

    Momi, Sukhleen K.; Fabiane, Stella Maris; Lachance, Genevieve; Livshits, Gregory; Williams, Frances M. K.

    2015-01-01

    Abstract Chronic widespread pain (CWP) has complex aetiology and forms part of the fibromyalgia syndrome. Recent evidence suggests a higher frequency of neuropathic pain features in those with CWP than previously thought. The aim of this study was to determine the prevalence of neuropathic pain features in individuals with CWP and to estimate the influence of genetic and environmental factors on neuropathic pain in CWP. Validated questionnaires (the London Fibromyalgia Screening Study questionnaire and PainDETECT questionnaire) were used to classify twins as having CWP and neuropathic pain, respectively. The prevalence of CWP was 14.7% (n = 4324), and of the 1357 twins invited to complete neuropathic pain screening, 15.9% of those having CWP demonstrated features of neuropathic pain. Neuropathic pain was found to be heritable (A = 37%; 95% confidence interval [CI]: 23%-50%) with unique environmental factors accounting for 63% (95% CI: 49%-79%) of the variance. Heritability of neuropathic pain and CWP were found to be correlated, 0.54 (95% CI: 0.42-0.65). Increasing age, raised body mass index, female gender, and smoking were all risk factors for neuropathic pain (P < 0.05), and CWP (P < 0.05). High socioeconomic status showed negative correlation with neuropathic pain (P = 0.003) and CWP (P = 0.001). Bivariate analysis of the 2 pain traits revealed that genetic predisposition to neuropathic pain is shared with that for CWP. This is the first study to provide formal heritability estimates for neuropathic pain in CWP. The findings suggest that at least some of the genetic factors underlying the development of neuropathic pain and CWP are the same. PMID:26121255

  10. Genetic, Epigenetic, and Environmental Factors Influencing Neurovisceral Integration of Cardiovascular Modulation: Focus on Multiple Sclerosis.

    PubMed

    Sternberg, Zohara

    2016-03-01

    Thought to be an autoimmune inflammatory CNS disease, multiple sclerosis (MS) involves multiple pathologies with heterogeneous clinical presentations. An impaired neurovisceral integration of cardiovascular modulation, indicated by sympathetic and parasympathetic autonomic nervous system (ANS) dysfunction, is among common MS clinical presentations. ANS dysfunction could not only enhance MS inflammatory and neurodegenerative processes, but can also lead to clinical symptoms such as depression, fatigue, sleep disorder, migraine, osteoporosis, and cerebral hemodynamic impairments. Therefore, factors influencing ANS functional activities, in one way or another, will have a significant impact on MS disease course. This review describes the genetic and epigenetic factors, and their interactions with a number of environmental factors contributing to the neurovisceral integration of cardiovascular modulation, with a focus on MS. Future studies should investigate the improvement in cardiovascular ANS function, as a strategy for preventing and minimizing MS-related morbidities, and improving patients' quality of life. PMID:26502224

  11. The influence of sex-linked genetic mechanisms on attention and impulsivity

    PubMed Central

    Trent, Simon; Davies, William

    2012-01-01

    It is now generally agreed that there are inherent sex differences in healthy individuals across a number of neurobiological domains (including brain structure, neurochemistry, and cognition). Moreover, there is a burgeoning body of evidence highlighting sex differences within neuropsychiatric populations (in terms of the rates of incidence, clinical features/progression, neurobiology and pathology). Here, we consider the extent to which attention and impulsivity are sexually dimorphic in healthy populations and the extent to which sex might modulate the expression of disorders characterised by abnormalities in attention and/or impulsivity such as attention deficit hyperactivity disorder (ADHD), autism and addiction. We then discuss general genetic mechanisms that might underlie sex differences in attention and impulsivity before focussing on specific positional and functional candidate sex-linked genes that are likely to influence these cognitive processes. Identifying novel sex-modulated molecular targets should ultimately enable us to develop more effective therapies in disorders associated with attentional/impulsive dysfunction. PMID:21983394

  12. Influence of XRCC1 Genetic Polymorphisms on Ionizing Radiation-Induced DNA Damage and Repair

    PubMed Central

    Sterpone, Silvia; Cozzi, Renata

    2010-01-01

    It is well known that ionizing radiation (IR) can damage DNA through a direct action, producing single- and double-strand breaks on DNA double helix, as well as an indirect effect by generating oxygen reactive species in the cells. Mammals have evolved several and distinct DNA repair pathways in order to maintain genomic stability and avoid tumour cell transformation. This review reports important data showing a huge interindividual variability on sensitivity to IR and in susceptibility to developing cancer; this variability is principally represented by genetic polymorphisms, that is, DNA repair gene polymorphisms. In particular we have focussed on single nucleotide polymorphisms (SNPs) of XRCC1, a gene that encodes for a scaffold protein involved basically in Base Excision Repair (BER). In this paper we have reported and presented recent studies that show an influence of XRCC1 variants on DNA repair capacity and susceptibility to breast cancer. PMID:20798883

  13. Genetic and environmental influences on girls' and boys' gender-typed and gender-neutral values.

    PubMed

    Knafo, Ariel; Spinath, Frank M

    2011-05-01

    In this first investigation of genetic and environmental influences on children's values, 271 German twin pairs (50.2% boys) reported their values at ages 7-11 years using the Portrait Values Questionnaire (Schwartz & Rubel, 2005). We distinguished between gender-neutral (conservation vs. openness to change) and gender-typed (self-transcendence vs. self-enhancement) values. Boys differed from girls in the importance given to gender-typed benevolence, achievement, and power values. Gender-neutral values showed moderate (.34) and gender-typed values showed higher (.49) heritability, with nonshared environment and error accounting for the remaining variance. For both sexes, substantial genetic effects accounted for the importance children gave to their respective gender-stereotypical end of the self-transcendence versus self-enhancement dimension. However, dramatic sex differences emerged in the gender-atypical end of the distribution. For girls, low self-transcendence (high gender-atypical values) showed a large (.76) group heritability. For boys, gender-atypical values (high self-transcendence) showed no heritability and a modest (.10) shared environment effect. PMID:21142356

  14. Genetic variants in novel pathways influence blood pressure and cardiovascular disease risk.

    PubMed

    Ehret, Georg B; Munroe, Patricia B; Rice, Kenneth M; Bochud, Murielle; Johnson, Andrew D; Chasman, Daniel I; Smith, Albert V; Tobin, Martin D; Verwoert, Germaine C; Hwang, Shih-Jen; Pihur, Vasyl; Vollenweider, Peter; O'Reilly, Paul F; Amin, Najaf; Bragg-Gresham, Jennifer L; Teumer, Alexander; Glazer, Nicole L; Launer, Lenore; Zhao, Jing Hua; Aulchenko, Yurii; Heath, Simon; Sõber, Siim; Parsa, Afshin; Luan, Jian'an; Arora, Pankaj; Dehghan, Abbas; Zhang, Feng; Lucas, Gavin; Hicks, Andrew A; Jackson, Anne U; Peden, John F; Tanaka, Toshiko; Wild, Sarah H; Rudan, Igor; Igl, Wilmar; Milaneschi, Yuri; Parker, Alex N; Fava, Cristiano; Chambers, John C; Fox, Ervin R; Kumari, Meena; Go, Min Jin; van der Harst, Pim; Kao, Wen Hong Linda; Sjögren, Marketa; Vinay, D G; Alexander, Myriam; Tabara, Yasuharu; Shaw-Hawkins, Sue; Whincup, Peter H; Liu, Yongmei; Shi, Gang; Kuusisto, Johanna; Tayo, Bamidele; Seielstad, Mark; Sim, Xueling; Nguyen, Khanh-Dung Hoang; Lehtimäki, Terho; Matullo, Giuseppe; Wu, Ying; Gaunt, Tom R; Onland-Moret, N Charlotte; Cooper, Matthew N; Platou, Carl G P; Org, Elin; Hardy, Rebecca; Dahgam, Santosh; Palmen, Jutta; Vitart, Veronique; Braund, Peter S; Kuznetsova, Tatiana; Uiterwaal, Cuno S P M; Adeyemo, Adebowale; Palmas, Walter; Campbell, Harry; Ludwig, Barbara; Tomaszewski, Maciej; Tzoulaki, Ioanna; Palmer, Nicholette D; Aspelund, Thor; Garcia, Melissa; Chang, Yen-Pei C; O'Connell, Jeffrey R; Steinle, Nanette I; Grobbee, Diederick E; Arking, Dan E; Kardia, Sharon L; Morrison, Alanna C; Hernandez, Dena; Najjar, Samer; McArdle, Wendy L; Hadley, David; Brown, Morris J; Connell, John M; Hingorani, Aroon D; Day, Ian N M; Lawlor, Debbie A; Beilby, John P; Lawrence, Robert W; Clarke, Robert; Hopewell, Jemma C; Ongen, Halit; Dreisbach, Albert W; Li, Yali; Young, J Hunter; Bis, Joshua C; Kähönen, Mika; Viikari, Jorma; Adair, Linda S; Lee, Nanette R; Chen, Ming-Huei; Olden, Matthias; Pattaro, Cristian; Bolton, Judith A Hoffman; Köttgen, Anna; Bergmann, Sven; Mooser, Vincent; Chaturvedi, Nish; Frayling, Timothy M; Islam, Muhammad; Jafar, Tazeen H; Erdmann, Jeanette; Kulkarni, Smita R; Bornstein, Stefan R; Grässler, Jürgen; Groop, Leif; Voight, Benjamin F; Kettunen, Johannes; Howard, Philip; Taylor, Andrew; Guarrera, Simonetta; Ricceri, Fulvio; Emilsson, Valur; Plump, Andrew; Barroso, Inês; Khaw, Kay-Tee; Weder, Alan B; Hunt, Steven C; Sun, Yan V; Bergman, Richard N; Collins, Francis S; Bonnycastle, Lori L; Scott, Laura J; Stringham, Heather M; Peltonen, Leena; Perola, Markus; Vartiainen, Erkki; Brand, Stefan-Martin; Staessen, Jan A; Wang, Thomas J; Burton, Paul R; Soler Artigas, Maria; Dong, Yanbin; Snieder, Harold; Wang, Xiaoling; Zhu, Haidong; Lohman, Kurt K; Rudock, Megan E; Heckbert, Susan R; Smith, Nicholas L; Wiggins, Kerri L; Doumatey, Ayo; Shriner, Daniel; Veldre, Gudrun; Viigimaa, Margus; Kinra, Sanjay; Prabhakaran, Dorairaj; Tripathy, Vikal; Langefeld, Carl D; Rosengren, Annika; Thelle, Dag S; Corsi, Anna Maria; Singleton, Andrew; Forrester, Terrence; Hilton, Gina; McKenzie, Colin A; Salako, Tunde; Iwai, Naoharu; Kita, Yoshikuni; Ogihara, Toshio; Ohkubo, Takayoshi; Okamura, Tomonori; Ueshima, Hirotsugu; Umemura, Satoshi; Eyheramendy, Susana; Meitinger, Thomas; Wichmann, H-Erich; Cho, Yoon Shin; Kim, Hyung-Lae; Lee, Jong-Young; Scott, James; Sehmi, Joban S; Zhang, Weihua; Hedblad, Bo; Nilsson, Peter; Smith, George Davey; Wong, Andrew; Narisu, Narisu; Stančáková, Alena; Raffel, Leslie J; Yao, Jie; Kathiresan, Sekar; O'Donnell, Christopher J; Schwartz, Stephen M; Ikram, M Arfan; Longstreth, W T; Mosley, Thomas H; Seshadri, Sudha; Shrine, Nick R G; Wain, Louise V; Morken, Mario A; Swift, Amy J; Laitinen, Jaana; Prokopenko, Inga; Zitting, Paavo; Cooper, Jackie A; Humphries, Steve E; Danesh, John; Rasheed, Asif; Goel, Anuj; Hamsten, Anders; Watkins, Hugh; Bakker, Stephan J L; van Gilst, Wiek H; Janipalli, Charles S; Mani, K Radha; Yajnik, Chittaranjan S; Hofman, Albert; Mattace-Raso, Francesco U S; Oostra, Ben A; Demirkan, Ayse; Isaacs, Aaron; Rivadeneira, Fernando; Lakatta, Edward G; Orru, Marco; Scuteri, Angelo; Ala-Korpela, Mika; Kangas, Antti J; Lyytikäinen, Leo-Pekka; Soininen, Pasi; Tukiainen, Taru; Würtz, Peter; Ong, Rick Twee-Hee; Dörr, Marcus; Kroemer, Heyo K; Völker, Uwe; Völzke, Henry; Galan, Pilar; Hercberg, Serge; Lathrop, Mark; Zelenika, Diana; Deloukas, Panos; Mangino, Massimo; Spector, Tim D; Zhai, Guangju; Meschia, James F; Nalls, Michael A; Sharma, Pankaj; Terzic, Janos; Kumar, M V Kranthi; Denniff, Matthew; Zukowska-Szczechowska, Ewa; Wagenknecht, Lynne E; Fowkes, F Gerald R; Charchar, Fadi J; Schwarz, Peter E H; Hayward, Caroline; Guo, Xiuqing; Rotimi, Charles; Bots, Michiel L; Brand, Eva; Samani, Nilesh J; Polasek, Ozren; Talmud, Philippa J; Nyberg, Fredrik; Kuh, Diana; Laan, Maris; Hveem, Kristian; Palmer, Lyle J; van der Schouw, Yvonne T; Casas, Juan P; Mohlke, Karen L; Vineis, Paolo; Raitakari, Olli; Ganesh, Santhi K; Wong, Tien Y; Tai, E Shyong; Cooper, Richard S; Laakso, Markku; Rao, Dabeeru C; Harris, Tamara B; Morris, Richard W; Dominiczak, Anna F; Kivimaki, Mika; Marmot, Michael G; Miki, Tetsuro; Saleheen, Danish; Chandak, Giriraj R; Coresh, Josef; Navis, Gerjan; Salomaa, Veikko; Han, Bok-Ghee; Zhu, Xiaofeng; Kooner, Jaspal S; Melander, Olle; Ridker, Paul M; Bandinelli, Stefania; Gyllensten, Ulf B; Wright, Alan F; Wilson, James F; Ferrucci, Luigi; Farrall, Martin; Tuomilehto, Jaakko; Pramstaller, Peter P; Elosua, Roberto; Soranzo, Nicole; Sijbrands, Eric J G; Altshuler, David; Loos, Ruth J F; Shuldiner, Alan R; Gieger, Christian; Meneton, Pierre; Uitterlinden, Andre G; Wareham, Nicholas J; Gudnason, Vilmundur; Rotter, Jerome I; Rettig, Rainer; Uda, Manuela; Strachan, David P; Witteman, Jacqueline C M; Hartikainen, Anna-Liisa; Beckmann, Jacques S; Boerwinkle, Eric; Vasan, Ramachandran S; Boehnke, Michael; Larson, Martin G; Järvelin, Marjo-Riitta; Psaty, Bruce M; Abecasis, Gonçalo R; Chakravarti, Aravinda; Elliott, Paul; van Duijn, Cornelia M; Newton-Cheh, Christopher; Levy, Daniel; Caulfield, Mark J; Johnson, Toby

    2011-10-01

    Blood pressure is a heritable trait influenced by several biological pathways and responsive to environmental stimuli. Over one billion people worldwide have hypertension (≥140 mm Hg systolic blood pressure or  ≥90 mm Hg diastolic blood pressure). Even small increments in blood pressure are associated with an increased risk of cardiovascular events. This genome-wide association study of systolic and diastolic blood pressure, which used a multi-stage design in 200,000 individuals of European descent, identified sixteen novel loci: six of these loci contain genes previously known or suspected to regulate blood pressure (GUCY1A3-GUCY1B3, NPR3-C5orf23, ADM, FURIN-FES, GOSR2, GNAS-EDN3); the other ten provide new clues to blood pressure physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke and coronary artery disease, but not kidney disease or kidney function. We also observed associations with blood pressure in East Asian, South Asian and African ancestry individuals. Our findings provide new insights into the genetics and biology of blood pressure, and suggest potential novel therapeutic pathways for cardiovascular disease prevention. PMID:21909115

  15. Genetic Variation in Functional Traits Influences Arthropod Community Composition in Aspen (Populus tremula L.)

    PubMed Central

    Robinson, Kathryn M.; Ingvarsson, Pär K.; Jansson, Stefan; Albrectsen, Benedicte R.

    2012-01-01

    We conducted a study of natural variation in functional leaf traits and herbivory in 116 clones of European aspen, Populus tremula L., the Swedish Aspen (SwAsp) collection, originating from ten degrees of latitude across Sweden and grown in a common garden. In surveys of phytophagous arthropods over two years, we found the aspen canopy supports nearly 100 morphospecies. We identified significant broad-sense heritability of plant functional traits, basic plant defence chemistry, and arthropod community traits. The majority of arthropods were specialists, those coevolved with P. tremula to tolerate and even utilize leaf defence compounds. Arthropod abundance and richness were more closely related to plant growth rates than general chemical defences and relationships were identified between the arthropod community and stem growth, leaf and petiole morphology, anthocyanins, and condensed tannins. Heritable genetic variation in plant traits in young aspen was found to structure arthropod community; however no single trait drives the preferences of arthropod folivores among young aspen genotypes. The influence of natural variation in plant traits on the arthropod community indicates the importance of maintaining genetic variation in wild trees as keystone species for biodiversity. It further suggests that aspen can be a resource for the study of mechanisms of natural resistance to herbivores. PMID:22662190

  16. Chronic bullying victimization across school transitions: The role of genetic and environmental influences

    PubMed Central

    Bowes, Lucy; Maughan, Barbara; Ball, Harriet; Shakoor, Sania; Ouellet-Morin, Isabelle; Caspi, Avshalom; Moffitt, Terrie E.; Arseneault, Louise

    2013-01-01

    We investigated the antecedents and consequences of chronic victimization by bullies across a school transition using a genetically sensitive longitudinal design. Data were from the Environmental Risk Longitudinal Twin Study (E-Risk), an epidemiological cohort of 2,232 children. We used mothers’ and children’s reports of bullying victimization during primary school and early secondary school. Children who experienced frequent victimization at both time points were classed as “chronic victims” and were found to have an increased risk for mental health problems and academic difficulties compared to children who were bullied only in primary school, children bullied for the first time in secondary school, and never-bullied children. Biometric analyses revealed that stability in victimization over this period was influenced primarily by genetic and shared environmental factors. Regression analyses showed that children’s early characteristics such as preexistent adjustment difficulties and IQ predicted chronic versus transitory victimization. Family risk factors for chronic victimization included socioeconomic disadvantage, low maternal warmth, and maltreatment. Our results suggest that bullying intervention programs should consider the role of the victims’ behaviors and family background in increasing vulnerability to chronic victimization. Our study highlights the importance of widening antibullying interventions to include families to reduce the likelihood of children entering a pathway toward chronic victimization. PMID:23627948

  17. Genetic Variants in Novel Pathways Influence Blood Pressure and Cardiovascular Disease Risk

    PubMed Central

    2011-01-01

    Blood pressure (BP) is a heritable trait1 influenced by multiple biological pathways and is responsive to environmental stimuli. Over one billion people worldwide have hypertension (BP ≥140 mm Hg systolic [SBP] or ≥90 mm Hg diastolic [DBP])2. Even small increments in BP are associated with increased risk of cardiovascular events3. This genome-wide association study of SBP and DBP, which used a multi-stage design in 200,000 individuals of European descent, identified 16 novel loci: six of these loci contain genes previously known or suspected to regulate BP (GUCY1A3-GUCY1B3; NPR3-C5orf23; ADM; FURIN-FES; GOSR2; GNAS-EDN3); the other 10 provide new clues to BP physiology. A genetic risk score based on 29 genome-wide significant variants was associated with hypertension, left ventricular wall thickness, stroke, and coronary artery disease, but not kidney disease or kidney function. We also observed associations with BP in East Asian, South Asian, and African ancestry individuals. Our findings provide new insights into the genetics and biology of BP, and suggest novel potential therapeutic pathways for cardiovascular disease prevention. PMID:21909115

  18. Detection and interpretation of shared genetic influences on 42 human traits.

    PubMed

    Pickrell, Joseph K; Berisa, Tomaz; Liu, Jimmy Z; Ségurel, Laure; Tung, Joyce Y; Hinds, David A

    2016-07-01

    We performed a scan for genetic variants associated with multiple phenotypes by comparing large genome-wide association studies (GWAS) of 42 traits or diseases. We identified 341 loci (at a false discovery rate of 10%) associated with multiple traits. Several loci are associated with multiple phenotypes; for example, a nonsynonymous variant in the zinc transporter SLC39A8 influences seven of the traits, including risk of schizophrenia (rs13107325: log-transformed odds ratio (log OR) = 0.15, P = 2 × 10(-12)) and Parkinson disease (log OR = -0.15, P = 1.6 × 10(-7)), among others. Second, we used these loci to identify traits that have multiple genetic causes in common. For example, variants associated with increased risk of schizophrenia also tended to be associated with increased risk of inflammatory bowel disease. Finally, we developed a method to identify pairs of traits that show evidence of a causal relationship. For example, we show evidence that increased body mass index causally increases triglyceride levels. PMID:27182965

  19. Environmental and Genetic Influences of Archaeal Lipid Distribution in Natural and Artificial Marine Environments

    NASA Astrophysics Data System (ADS)

    Warren, C.; Pagani, M.

    2012-12-01

    TEX86 is a proxy of sea surface temperature based on refractory glycerol dibiphytanyl glycerol tetraethers (GDGT) in the cell membranes of low-temperature dwelling (non-hyperthermophilic) Archaea. The degree to which environmental signals other than temperature influence the distribution of GDGT compounds is poorly understood. Few representatives of the Thaumarchaeota — the clade to which the dominant GDGT production has been attributed — have been described or isolated in pure culture, and the role of genetic lineage in the synthesis and distribution of GDGTs is unknown. For this project we collected water, filter and substrate samples from tank systems in non-profit and commercial aquariums around the United States. This analysis compares GDGT core lipids and intact polar lipid distributions with Archaeal genetic sequence data processed using rRNA and 454 Pyrosequencing. Environmental attributes (such as dissolved oxygen concentration, salinity, organic density, etc.) specific to each tank are also compared to lipid analyses and the presence of specific lineages within select tank systems. Our preliminary results demonstrate that archaeal GDGTs are present and abundant within a range of environmental conditions, including artificial saline and brackish waters derived from municipal sources. Comparisons of existing TEX86 calibration values with known temperatures suggest that residuals vary based on non-temperature parameters. Branched compounds are absent in most aquarium systems, but dominate in systems prepared with municipal water.

  20. Influence of Genetic Background on Anthocyanin and Copigment Composition and Behavior during Thermoalkaline Processing of Maize.

    PubMed

    Collison, Amy; Yang, Liyi; Dykes, Linda; Murray, Seth; Awika, Joseph M

    2015-06-10

    Visual color is a primary quality factor for foods purchase; identifying factors that influence in situ color quality of pigmented maize during processing is important. Twenty-four genetically distinct pigmented maize hybrids (red/blue, blue, red, and purple) were used to investigate the effect of pigment and copigment composition on color stability during nixtamalization and tortilla chip processing. The red/blue and blue samples generally contained higher proportions of acylated anthocyanins (mainly cyanidin-3-(6″-malonylglucoside)) than the red and purple color classes. Phenolic amides were the major extractable copigments in all samples (450-764 μg/g), with red samples containing the most putrescines and blue samples containing the most spermidines. Even though samples with higher proportions of acylated anthocyanins retained more pigments during processing, this did not relate to final product color quality. In general, the red/blue samples retained their color quality the best and thus are good candidates for genetic improvement for direct processing into alkalized products. PMID:26010030

  1. Chronic bullying victimization across school transitions: the role of genetic and environmental influences.

    PubMed

    Bowes, Lucy; Maughan, Barbara; Ball, Harriet; Shakoor, Sania; Ouellet-Morin, Isabelle; Caspi, Avshalom; Moffitt, Terrie E; Arseneault, Louise

    2013-05-01

    We investigated the antecedents and consequences of chronic victimization by bullies across a school transition using a genetically sensitive longitudinal design. Data were from the Environmental Risk Longitudinal Twin Study (E-Risk), an epidemiological cohort of 2,232 children. We used mothers' and children's reports of bullying victimization during primary school and early secondary school. Children who experienced frequent victimization at both time points were classed as "chronic victims" and were found to have an increased risk for mental health problems and academic difficulties compared to children who were bullied only in primary school, children bullied for the first time in secondary school, and never-bullied children. Biometric analyses revealed that stability in victimization over this period was influenced primarily by genetic and shared environmental factors. Regression analyses showed that children's early characteristics such as preexistent adjustment difficulties and IQ predicted chronic versus transitory victimization. Family risk factors for chronic victimization included socioeconomic disadvantage, low maternal warmth, and maltreatment. Our results suggest that bullying intervention programs should consider the role of the victims' behaviors and family background in increasing vulnerability to chronic victimization. Our study highlights the importance of widening antibullying interventions to include families to reduce the likelihood of children entering a pathway toward chronic victimization. PMID:23627948

  2. Tumor necrosis factor-alpha genetic predisposing factors can influence clinical severity in nephropathia epidemica.

    PubMed

    Maes, Piet; Clement, Jan; Groeneveld, Paul H P; Colson, Paul; Huizinga, Tom W J; Van Ranst, Marc

    2006-01-01

    Severe human infection with Hantavirus is characterized by high fever, cold chills, thrombocytopenia, arterial hypotension, acute renal failure, and/or adult respiratory distress syndrome (ARDS)-like pulmonary involvement, but the clinical course varies greatly between individuals. We investigated whether genetically determined differences in tumor necrosis factor (TNF)-alpha production can influence the severity of Hantavirus disease. We studied a TNF-alpha single-nucleotide promoter polymorphism (SNP) at position -238 (a guanine [G]-to-adenine [A] transition) and ex vivo TNF-alpha production in a recall study of 36 Belgian patients who had a serologically proven form of Puumala virus-induced Hantavirus infection with the kidney as main target organ. In our study, the highest creatinine levels were found in patients with the lowest ex vivo TNF-alpha production. Creatinine levels correlated inversely with TNF-alpha production (R = -0.35, p < 0.05). The number of thrombocytes was significantly lower in patients with the GA-238 genotype (low TNF-alpha producers) compared with patients with the GG-238 genotype. In our study, genetically determined low production of TNF-alpha was associated with some parameters indicating a more severe clinical course of Puumala Hantavirus infection in humans, possibly by impaired activation of TNF-alpha-dependent antiviral mechanisms, which could in turn result in decreased clearance of Hantavirus. PMID:16987073

  3. The Influence of Genetic Variability and Proinflammatory Status on the Development of Bone Disease in Patients with Gaucher Disease

    PubMed Central

    Gervas-Arruga, Javier; Cebolla, Jorge Javier; de Blas, Ignacio; Roca, Mercedes; Pocovi, Miguel; Giraldo, Pilar

    2015-01-01

    Gaucher disease, the most common lysosomal storage disorder, is caused by β-glucocerebrosidase deficiency. Bone complications are the major cause of morbidity in patients with type 1 Gaucher disease (GD1). Genetic components strongly influence bone remodelling. In addition, chronic inflammation produced by Gaucher cells induces the production of several cytokines, which leads to direct changes in the bone remodelling process and can also affect the process indirectly through other immune cells. In this study, we analysed the association between bone mineral density (BMD), bone marrow burden score, and relevant genetic polymorphisms related to bone metabolism, as well as profiles of proinflammatory cytokines in a GD1 cohort. This study included 83 patients distributed according to bone status. BMD was measured with DXA and broadband ultrasound attenuation; bone marrow involvement was evaluated using MRI. We also analysed 26 SNPs located in 14 genes related to bone metabolism. To assess proinflammatory status, we analysed IL-4, IL-6, IL-7, IL-10, IL-13, MIP-1α, MIP-1β, and TNFα in plasma samples from 71 control participants and GD1 patients. SNP genotype proportions and BMD differed significantly between ESRI c.453-397T>C and VDR c.1024+283G>A variants. We also observed significant associations between GD1 genotypes and bone affectation. When patients were stratified by spleen status, we observed significant correlations between non-/splenectomized groups and Spanish MRI (S-MRI) score. Across genotype proportions of non-/splenectomized patients and S-MRI, we observed significant differences in ESRI c.453-397T>C, VDR c.-83-25988G>A, and TNFRSF11B c.9C>G polymorphisms. We observed different significant proinflammatory profiles between control participants, treatment-naïve patients, and patients on enzyme replacement therapy (ERT); between non-/splenectomized patients (between untreated and ERT-treated patients) and among those with differing GBA genotypes. The

  4. Genetic Variants Influencing Joint Damage in Mexican Americans and European Americans With Rheumatoid Arthritis.

    PubMed

    Arya, Rector; Del Rincon, Inmaculada; Farook, Vidya S; Restrepo, Jose F; Winnier, Diedre A; Fourcaudot, Marcel J; Battafarano, Daniel F; de Almeida, Marcio; Kumar, Satish; Curran, Joanne E; Jenkinson, Christopher P; Blangero, John; Duggirala, Ravindranath; Escalante, Agustin

    2015-12-01

    Joint destruction in rheumatoid arthritis (RA) is heritable, but knowledge on specific genetic determinants of joint damage in RA is limited. We have used the Immunochip array to examine whether genetic variants influence variation in joint damage in a cohort of Mexican Americans (MA) and European Americans (EA) with RA. We studied 720 MA and 424 EA patients with RA. Joint damage was quantified using a radiograph of both hands and wrists, scored using Sharp's technique. We conducted association analyses with the transformed Sharp score and the Immunochip single nucleotide polymorphism (SNP) data using PLINK. In MAs, 15 SNPs from chromosomes 1, 5, 9, 17 and 22 associated with joint damage yielded strong p-values (p < 1 × 10(-4) ). The strongest association with joint damage was observed with rs7216796, an intronic SNP located in the MAP3K14 gene, on chromosome 17 (β ± SE = -0.25 ± 0.05, p = 6.23 × 10(-6) ). In EAs, 28 SNPs from chromosomes 1, 4, 6, 9, and 21 showed associations with joint damage (p-value < 1 × 10(-4) ). The best association was observed on chromosome 9 with rs59902911 (β ± SE = 0.86 ± 0.17, p = 1.01 × 10(-6) ), a synonymous SNP within the CARD9 gene. We also observed suggestive evidence for some loci influencing joint damage in MAs and EAs. We identified two novel independent loci (MAP3K14 and CARD9) strongly associated with joint damage in MAs and EAs and a few shared loci showing suggestive evidence for association. PMID:26498133

  5. Genetic influences on response to novel objects and dimensions of personality in Papio baboons.

    PubMed

    Johnson, Zachary; Brent, Linda; Alvarenga, Juan Carlos; Comuzzie, Anthony G; Shelledy, Wendy; Ramirez, Stephanie; Cox, Laura; Mahaney, Michael C; Huang, Yung-Yu; Mann, J John; Kaplan, Jay R; Rogers, Jeffrey

    2015-03-01

    Behavioral variation within and between populations and species of the genus Papio has been studied extensively, but little is known about the genetic causes of individual- or population-level differences. This study investigates the influence of genetic variation on personality (sometimes referred to as temperament) in baboons and identifies a candidate gene partially responsible for the variation in that phenotype. To accomplish these goals, we examined individual variation in response to both novel objects and an apparent novel social partner (using a mirror test) among pedigreed baboons (n = 578) from the Southwest National Primate Research Center. We investigated the frequency and duration of individual behaviors in response to novel objects and used multivariate factor analysis to identify trait-like dimensions of personality. Exploratory factor analysis identified two distinct dimensions of personality within this population. Factor 1 accounts for 46.8 % of the variance within the behavioral matrix, and consists primarily of behaviors related to the "boldness" of the subject. Factor 2 accounts for 18.8 % of the variation, and contains several "anxiety" like behaviors. Several specific behaviors, and the two personality factors, were significantly heritable, with the factors showing higher heritability than most individual behaviors. Subsequent analyses show that the behavioral reactions observed in the test protocol are associated with animals' social behavior observed later in their home social groups. Finally we used linkage analysis to map quantitative trait loci for the measured phenotypes. Single nucleotide polymorphisms in a positional candidate gene (SNAP25) are associated with variation in one of the personality factors, and CSF levels of homovanillic acid and 3-methoxy-4-hydroxyphenylglycol. This study documents heritable variation in personality among baboons and suggests that sequence variation in SNAP25 may influence differences in behavior and

  6. Numerical study of water entry supercavitating flow around a vertical circular cylinder influenced by turbulent drag-reducing additives

    NASA Astrophysics Data System (ADS)

    Jiang, C. X.; Cheng, J. P.; Li, F. C.

    2015-01-01

    This paper attempts to introduce a numerical simulation procedure to simulate water-entry problems influenced by turbulent drag-reducing additives in a viscous incompressible medium. Firstly we performed a numerical investigation on water-entry supercavities in water and turbulent drag-reducing solution at the impact velocity of 28.4 m/s to confirm the accuracy of the numerical method. Based on the verification, projectile entering water and turbulent drag-reducing solution at relatively high velocity of 142.7 m/s (phase transition is considered) is simulated. The cross viscosity equation was adopted to represent the shear-thinning characteristic of aqueous solution of drag-reducing additives. The configuration and dynamic characteristics of water entry supercavity, flow resistance were discussed respectively. It was obtained that the numerical simulation results are in consistence with experimental data. Numerical results show that the supercavity length in drag-reducing solution is larger than one in water and the velocity attenuates faster at high velocity than at low velocity; the influence of drag-reducing solution is more obvious at high impact velocity. Turbulent drag-reducing additives have the great potential for enhancement of supercavity.

  7. Migration of additive molecules in a polymer filament obtained by melt spinning: Influence of the fiber processing steps

    NASA Astrophysics Data System (ADS)

    Gesta, E.; Skovmand, O.; Espuche, E.; Fulchiron, R.

    2015-12-01

    The purpose of this study is to understand the influence of the yarn processing on the migration of additives molecules, especially insecticide, within polyethylene (PE) yarns. Yarns were manufactured in the laboratory focusing on three key-steps (spinning, post-stretching and heat-setting). Influence of each step on yarn properties was investigated using tensile tests, differential scanning calorimetry and wide-angle X-ray diffraction. The post-stretching step was proved to be critical in defining yarn mechanical and structural properties. Although a first orientation of polyethylene crystals was induced during spinning, the optimal orientation was only reached by post-stretching. The results also showed that the heat-setting did not significantly change these properties. The presence of additives crystals at the yarn surface was evidenced by scanning-electron microscopy. These studies performed at each yarn production step allowed a detailed analysis of the additives' ability to migrate. It is concluded that while post-stretching decreased the migration rate, heat-setting seems to boost this migration.

  8. The theory of planned behaviour and healthy eating: Examining additive and moderating effects of social influence variables.

    PubMed

    Povey, R; Conner, M; Sparks, P; James, R; Shepherd, R

    2000-11-01

    Abstract This paper examines the additive and moderating effects of social influence variables (injunctive norms, descriptive norms, perceived social support) within the Theory of Planned Behaviour (TPB). The target behaviour is the decision to eat healthily. Questionnaire responses on components of the TPB, descriptive norms, perceived social support, and subsequent healthy eating were obtained from a prospective sample of 235 members of the general public. Good predictions of intentions (42% of variance explained) and behaviour (15% of variance explained) were found using the Theory of Planned Behaviour. Neither descriptive norms nor perceived social support added to these predictions of intentions over and above the TPB variables. However, perceived social support was found to act as a moderator variable on the relationship between perceived behavioral control and intention, and the relationship between attitude and intention. Implications for exploring the role of social influence variables on decisions concerning health behavioun an discussed. PMID:22175258

  9. Influence of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission.

    PubMed

    Keskin, Ali; Gürü, Metin; Altiparmak, Duran

    2008-09-01

    The purpose of this study is to investigate influences of tall oil biodiesel with Mg and Mo based fuel additives on diesel engine performance and emission. Tall oil resinic acids were reacted with MgO and MoO(2) stoichiometrically for the production of metal-based fuel additives (combustion catalysts). The metal-based additives were added into tall oil biodiesel (B60) at the rate of 4 micromol/l, 8 micromol/l and 12 micromol/l for preparing test fuels. In general, both of the metal-based additives improved flash point, pour point and viscosity of the biodiesel fuel, depending on the rate of additives. A single cylinder DI diesel engine was used in the tests. Engine performance values did not change significantly with biodiesel fuels, but exhaust emission profile was improved. CO emissions and smoke opacity decreased by 56.42% and by 30.43%, respectively. In general, low NO(x) and CO(2) emissions were measured with the biodiesel fuels. PMID:18164614

  10. Evaluation of the IL2/IL21, IL2RA and IL2RB genetic variants influence on the endogenous non-anterior uveitis genetic predisposition

    PubMed Central

    2013-01-01

    Background Recently, different genetic variants located within the IL2/IL21 genetic region as well as within both IL2RA and IL2RB loci have been associated to multiple autoimmune disorders. We aimed to investigate for the first time the potential influence of the IL2/IL21, IL2RA and IL2RB most associated polymorphisms with autoimmunity on the endogenous non-anterior uveitis genetic predisposition. Methods A total of 196 patients with endogenous non-anterior uveitis and 760 healthy controls, all of them from Caucasian population, were included in the current study. The IL2/IL21 (rs2069762, rs6822844 and rs907715), IL2RA (2104286, rs11594656 and rs12722495) and IL2RB (rs743777) genetic variants were genotyped using TaqMan® allelic discrimination assays. Results A statistically significant difference was found for the rs6822844 (IL2/IL21 region) minor allele frequency in the group of uveitis patients compared with controls (P-value=0.02, OR=0.64 CI 95%=0.43-0.94) although the significance was lost after multiple testing correction. Furthermore, no evidence of association with uveitis was detected for the analyzed genetic variants of the IL2RA or IL2RB loci. Conclusion Our results indicate that analyzed IL2/IL21, IL2RA and IL2RB polymorphisms do not seem to play a significant role on the non-anterior uveitis genetic predisposition although further studies are needed in order to clear up the influence of these loci on the non-anterior uveitis susceptibility. PMID:23676143

  11. Great influence of geographic isolation on the genetic differentiation of Myriophyllum spicatum under a steep environmental gradient

    PubMed Central

    Wu, Zhigang; Yu, Dan; Wang, Zhong; Li, Xing; Xu, Xinwei

    2015-01-01

    Understanding how natural processes affect population genetic structures is an important issue in evolutionary biology. One effective method is to assess the relative importance of environmental and geographical factors in the genetic structure of populations. In this study, we examined the spatial genetic variation of thirteen Myriophyllum spicatum populations from the Qinghai-Tibetan Plateau (QTP) and adjacent highlands (Yunnan-Guizhou Plateau, YGP) by using microsatellite loci and environmental and geographical factors. Bioclim layers, hydrological properties and elevation were considered as environmental variables and reduced by principal component analysis. The genetic isolation by geographic distance (IBD) was tested by Mantel tests and the relative importance of environmental variables on population genetic differentiation was determined by a partial Mantel test and multiple matrix regression with randomization (MMRR). Two genetic clusters corresponding to the QTP and YGP were identified. Both tests and MMRR revealed a significant and strong correlation between genetic divergence and geographic isolation under the influence of environmental heterogeneity at the overall and finer spatial scales. Our findings suggested the dominant role of geography on the evolution of M. spicatum under a steep environmental gradient in the alpine landscape as a result of dispersal limitation and genetic drift. PMID:26494202

  12. Conceptual and Data-based Investigation of Genetic Influences and Brain Asymmetry: A Twin Study of Multiple Structural Phenotypes

    PubMed Central

    Eyler, Lisa T.; Vuoksimaa, Eero; Panizzon, Matthew S.; Fennema-Notestine, Christine; Neale, Michael C.; Chen, Chi-Hua; Jak, Amy; Franz, Carol E.; Lyons, Michael J.; Thompson, Wesley K.; Spoon, Kelly M.; Fischl, Bruce; Dale, Anders M.; Kremen, William S.

    2014-01-01

    Right–left regional cerebral differences are a feature of the human brain linked to functional abilities, aging, and neuro-developmental and mental disorders. The role of genetic factors in structural asymmetry has been incompletely studied. We analyzed data from 515 individuals (130 monozygotic twin pairs, 97 dizygotic pairs, and 61 unpaired twins) from the Vietnam Era Twin Study of Aging to answer three questions about genetic determinants of brain structural asymmetry: First, does the magnitude of heritability differ for homologous regions in each hemisphere? Despite adequate power to detect regional differences, heritability estimates were not significantly larger in one hemisphere versus the other, except left > right inferior lateral ventricle heritability. Second, do different genetic factors influence left and right hemisphere size in homologous regions? Inter-hemispheric genetic correlations were high and significant; in only two subcortical regions (pallidum and accumbens) did the estimate statistically differ from 1.0. Thus, there was little evidence for different genetic influences on left and right hemisphere regions. Third, to what extent do genetic factors influence variability in left–right size differences? There was no evidence that variation in asymmetry (i.e., the size difference) of left and right homologous regions was genetically determined, except in pallidum and accumbens. Our findings suggest that genetic factors do not play a significant role in determining individual variation in the degree of regional cortical size asymmetries measured with MRI, although they may do so for volume of some subcortical structures. Despite varying interpretations of existing left–right, we view the present results as consistent with previous findings. PMID:24283492

  13. The influence of small impurity additions and direct electric current on the kinetics of contact melting in metals

    NASA Astrophysics Data System (ADS)

    Ahkubekov, A. A.; Ahkubekova, S. N.; Enaldieva, O. L.; Orkvasov, T. A.; Sozaev, V. A.

    2008-02-01

    Using the experimental data on contact melting of polycrystalline indium, tin and lead - based solid solutions with low-melting alloys we show that besides the diffusive, adhesive and low - dimensional mechanisms of contact melting it is necessary to take into account the segregational mechanism as well. The surfaces of a contact between the polycrystalline solid solutions and low - melting metals enrich in lower melting components due to the grain-boundary and surface segregation. One can influence on the kinetics of contact melting using alkali metals as impurity additives and applying the direct electric current. For example, the sodium addition to indium results in 3 times expansion of contact layer in the (In + 0.1 at. % Na) - Bi system, but in 2 times shrinking of that layer in the (In + 0.1 at. % Na) - Cd system in comparison to experiments without impurities.

  14. The influence of deposit control additives on nitrogen oxides emissions from spark ignition engines (case study: Tehran).

    PubMed

    Bidhendi, Gholamreza Nabi; Zand, Ali Daryabeigi; Tabrizi, Alireza Mikaeili; Pezeshk, Hamid; Baghvand, Akbar

    2007-04-15

    In the present research, the influence of a deposit control additive on NOx emissions from two types of gasoline engine vehicles i.e., Peykan (base on Hillman) and Pride (South Korea Kia motors) was studied. Exhaust NOx emissions were measured in to stages, before decarbonization process and after that. Statistical analysis was conducted on the measurement results. Results showed that NOx emissions from Peykans increased 0.28% and NOx emissions from Pride automobiles decreased 6.18% on average, due to the elimination of engine deposits. The observed variations were not statistically and practically significant. The results indicated that making use of detergent additives is not an effective way to reduce the exhaust NOx emissions from gasoline engine vehicles. PMID:19069943

  15. Do intrauterine or genetic influences explain the foetal origins of chronic disease? A novel experimental method for disentangling effects

    PubMed Central

    Thapar, Anita; Harold, Gordon; Rice, Frances; Ge, XiaoJia; Boivin, Jacky; Hay, Dale; van den Bree, Marianne; Lewis, Allyson

    2007-01-01

    Background There is much evidence to suggest that risk for common clinical disorders begins in foetal life. Exposure to environmental risk factors however is often not random. Many commonly used indices of prenatal adversity (e.g. maternal gestational stress, gestational diabetes, smoking in pregnancy) are influenced by maternal genes and genetically influenced maternal behaviour. As mother provides the baby with both genes and prenatal environment, associations between prenatal risk factors and offspring disease maybe attributable to true prenatal risk effects or to the "confounding" effects of genetic liability that are shared by mother and offspring. Cross-fostering designs, including those that involve embryo transfer have proved useful in animal studies. However disentangling these effects in humans poses significant problems for traditional genetic epidemiological research designs. Methods We present a novel research strategy aimed at disentangling maternally provided pre-natal environmental and inherited genetic effects. Families of children aged 5 to 9 years born by assisted reproductive technologies, specifically homologous IVF, sperm donation, egg donation, embryo donation and gestational surrogacy were contacted through fertility clinics and mailed a package of questionnaires on health and mental health related risk factors and outcomes. Further data were obtained from antenatal records. Results To date 741 families from 18 fertility clinics have participated. The degree of association between maternally provided prenatal risk factor and child outcome in the group of families where the woman undergoing pregnancy and offspring are genetically related (homologous IVF, sperm donation) is compared to association in the group where offspring are genetically unrelated to the woman who undergoes the pregnancy (egg donation, embryo donation, surrogacy). These comparisons can be then examined to infer the extent to which prenatal effects are genetically and

  16. Genetic Variants in Nuclear-Encoded Mitochondrial Genes Influence AIDS Progression

    PubMed Central

    Hendrickson, Sher L.; Lautenberger, James A.; Chinn, Leslie Wei; Malasky, Michael; Sezgin, Efe; Kingsley, Lawrence A.; Goedert, James J.; Kirk, Gregory D.; Gomperts, Edward D.; Buchbinder, Susan P.; Troyer, Jennifer L.; O'Brien, Stephen J.

    2010-01-01

    Background The human mitochondrial genome includes only 13 coding genes while nuclear-encoded genes account for 99% of proteins responsible for mitochondrial morphology, redox regulation, and energetics. Mitochondrial pathogenesis occurs in HIV patients and genetically, mitochondrial DNA haplogroups with presumed functional differences have been associated with differential AIDS progression. Methodology/Principal Findings Here we explore whether single nucleotide polymorphisms (SNPs) within 904 of the estimated 1,500 genes that specify nuclear-encoded mitochondrial proteins (NEMPs) influence AIDS progression among HIV-1 infected patients. We examined NEMPs for association with the rate of AIDS progression using genotypes generated by an Affymetrix 6.0 genotyping array of 1,455 European American patients from five US AIDS cohorts. Successfully genotyped SNPs gave 50% or better haplotype coverage for 679 of known NEMP genes. With a Bonferroni adjustment for the number of genes and tests examined, multiple SNPs within two NEMP genes showed significant association with AIDS progression: acyl-CoA synthetase medium-chain family member 4 (ACSM4) on chromosome 12 and peroxisomal D3,D2-enoyl-CoA isomerase (PECI) on chromosome 6. Conclusions Our previous studies on mitochondrial DNA showed that European haplogroups with presumed functional differences were associated with AIDS progression and HAART mediated adverse events. The modest influences of nuclear-encoded mitochondrial genes found in the current study add support to the idea that mitochondrial function plays a role in AIDS pathogenesis. PMID:20877624

  17. The influence of genetic variants on striatal dopamine transporter and D2 receptor binding after TBI.

    PubMed

    Wagner, Amy K; Scanlon, Joelle M; Becker, Carl R; Ritter, Anne C; Niyonkuru, Christian; Dixon, Clifton E; Conley, Yvette P; Price, Julie C

    2014-08-01

    Dopamine (DA) neurotransmission influences cognition and recovery after traumatic brain injury (TBI). We explored whether functional genetic variants affecting the DA transporter (DAT) and D2 receptor (DRD2) impacted in vivo dopaminergic binding with positron emission tomography (PET) using [(11)C]βCFT and [(11)C]raclopride. We examined subjects with moderate/severe TBI (N=12) ∼1 year post injury and similarly matched healthy controls (N=13). The variable number of tandem repeat polymorphism within the DAT gene and the TaqI restriction fragment length polymorphism near the DRD2 gene were assessed. TBI subjects had age-adjusted DAT-binding reductions in the caudate, putamen, and ventral striatum, and modestly increased D2 binding in ventral striatum versus controls. Despite small sample sizes, multivariate analysis showed lower caudate and putamen DAT binding among DAT 9-allele carriers and DRD2 A2/A2 homozygotes with TBI versus controls with the same genotype. Among TBI subjects, 9-allele carriers had lower caudate and putamen binding than 10/10 homozygotes. This PET study suggests a hypodopaminergic environment and altered DRD2 autoreceptor DAT interactions that may influence DA transmission after TBI. Future work will relate these findings to cognitive performance; future studies are required to determine how DRD2/DAT1 genotype and DA-ligand binding are associated with neurostimulant response and TBI recovery. PMID:24849661

  18. Alcohol Response and Consumption in Adolescent Rhesus Macaques: Life History and Genetic Influences

    PubMed Central

    Schwandt, Melanie L.; Lindell, Stephen G.; Chen, Scott; Higley, J. Dee; Suomi, Stephen J.; Heilig, Markus; Barr, Christina S.

    2009-01-01

    The use of alcohol by adolescents is a growing problem and has become an important research topic in the etiology of the alcohol use disorders. A key component of this research has been the development of animal models of adolescent alcohol consumption and alcohol response. Due to their extended period of adolescence, rhesus macaques are especially well-suited for modeling alcohol-related phenotypes that contribute to the adolescent propensity for alcohol consumption. In this review, we discuss studies from our laboratory that have investigated both the initial response to acute alcohol administration and the consumption of alcohol in voluntary self-administration paradigms in adolescent rhesus macaques. These studies confirm that adolescence is a time of dynamic change both behaviorally and physiologically, and that alcohol response and alcohol consumption are influenced by life history variables such as age, sex, and adverse early experience in the form of peer-rearing. Furthermore, genetic variants that alter functioning of the serotonin, endogenous opioid, and corticotropin releasing hormone systems are shown to influence both physiological and behavioral outcomes, in some cases interacting with early experience to indicate gene by environment interactions. These findings highlight several of the pathways involved in alcohol response and consumption, namely reward, behavioral dyscontrol, and vulnerability to stress, and demonstrate a role for these pathways during the early stages of alcohol exposure in adolescence. PMID:20113875

  19. Shared Genetic Influences Between Attention-Deficit/Hyperactivity Disorder (ADHD) Traits in Children and Clinical ADHD

    PubMed Central

    Stergiakouli, Evie; Martin, Joanna; Hamshere, Marian L.; Langley, Kate; Evans, David M.; St Pourcain, Beate; Timpson, Nicholas J.; Owen, Michael J.; O'Donovan, Michael; Thapar, Anita; Davey Smith, George

    2015-01-01

    Objective Twin studies and genome-wide complex trait analysis (GCTA) are not in agreement regarding heritability estimates for behavioral traits in children from the general population. This has sparked a debate on the possible difference in genetic architecture between behavioral traits and psychiatric disorders. In this study, we test whether polygenic risk scores associated with variation in attention-deficit/hyperactivity disorder (ADHD) trait levels in children from the general population predict ADHD diagnostic status and severity in an independent clinical sample. Method Single nucleotide polymorphisms (SNPs) with p < .5 from a genome-wide association study of ADHD traits in 4,546 children (mean age, 7 years 7 months) from the Avon Longitudinal Study of Parents and Children (ALSPAC; general population sample) were selected to calculate polygenic risk scores in 508 children with an ADHD diagnosis (independent clinical sample) and 5,081 control participants. Polygenic scores were tested for association with case-control status and severity of disorder in the clinical sample. Results Increased polygenic score for ADHD traits predicted ADHD case-control status (odds ratio = 1.17 [95% CI = 1.08–1.28], p = .0003), higher ADHD symptom severity (β = 0.29 [95% CI = 0.04–0.54], p = 0.02), and symptom domain severity in the clinical sample. Conclusion This study highlights the relevance of additive genetic variance in ADHD, and provides evidence that shared genetic factors contribute to both behavioral traits in the general population and psychiatric disorders at least in the case of ADHD. PMID:25791149

  20. Influence of the NaCl/LiF additives on structure, phasetransitions and dielectric properties of BSPT ceramics

    NASA Astrophysics Data System (ADS)

    Golubko, N. V.; Kaleva, G. M.; Mosunov, A. V.; Politova, E. D.; Segalla, A. H.

    2016-04-01

    Influence of the NaCl/LiF additives (with ratio 60:40) on structure parameters, phase transitions and dielectric properties of solid solutions close to the Morphotropic Phase Boundary in the system (1-x)BiScO3 - xPbTiO3 (x=0.635, 0.645) has been studied. Using as initial the BSPT powders prepared from nitrate solutions, dense single phase ceramic samples doped by 5, 10 and 15 w. % of NaCl/LiF have been prepared at 1313 - 1323 K (2 h). Shift of the BSPT compositions phase content from initial mixtures of Rhombohedral and Tetragonal phases to the region of Tetragonal phase was stimulated by addition of the NaCl/LiF additives. This effect is accompanied by decrease of the unit sell volume, increase in the c/a ratio and increase in the Curie temperature value from 668 to 730 K for x=0.635 and from 672 to 724 K for x=0.645 in compositions doped by 10 w. % of the NaCl/LiF additive.

  1. Influence of genetic factors on the ephedrine alkaloid composition ratio of Ephedra plants.

    PubMed

    Matsumoto, Masashi; Hirayama, Manabu; Ohtomi, Norihiro; Ohno, Takeshi; Nomura, Yukihiro; Iida, Osamu; Sugimura, Koji; Kawahara, Nobuo; Tsuchida, Takashi; Mikage, Masayuki

    2015-01-01

    We investigated the ephedrine alkaloid [(-)-ephedrine and (+)-pseudoephedrine] composition ratio of a crude Chinese herbal drug described in the Japanese Pharmacopoeia 'Ephedra herb (Chinese name: Mahuang)'. There were marked changes in the alkaloid composition ratio of wild plants in areas where both male and female clusters coexisted. However, in genetically homogeneous areas with the growth of male or female clusters alone, all of the coefficients of the regression lines were positive, but each gradient varied. This suggests that the alkaloid composition ratio has a clear tendency in each individual. Based on this, we cultivated individuals for vegetative propagation, and evaluated the alkaloid content ratio. Those propagated by separating the roots showed a specific tendency regardless of the cultivation area (Wakayama, Tanegashima). Those propagated by separating the herbaceous stem showed a specific tendency regardless of the soil or harvest time. In addition, we surveyed the (-)-ephedrine content ratio of 3- to 6-year-old strains. There was a high positive correlation coefficient between the previous and subsequent years. These findings suggest that the ephedrine alkaloid composition ratio of Ephedra herb depends on genetic factors, but not on environmental factors or the growth period. PMID:25115226

  2. Risk and Resilience: Genetic and Environmental Influences on Development of the Stress Response

    PubMed Central

    Gillespie, Charles F.; Phifer, Justine; Bradley, Bekh; Ressler, Kerry J.

    2010-01-01

    Exposure to stressful events during development has consistently been shown to produce long-lasting alterations in the hypothalamic-pituitary-adrenal (HPA) axis, which may increase vulnerability to disease, including PTSD and other mood and anxiety disorders. Recently reported genetic association studies indicate that these effects may be mediated, in part, by gene x environment (GxE) interactions involving polymorphisms within two key genes, CRHR1 and FKBP5. Data suggest that these genes regulate HPA axis function in conjunction with exposure to child maltreatment or abuse. In addition, a large and growing body of preclinical research suggests that increased activity of the amygdala-HPA axis induced by experimental manipulation of the amygdala mimics several of the physiological and behavioral symptoms of stress-related psychiatric illness in humans. Notably, interactions between the developing amygdala and HPA axis underlie critical periods for emotional learning which are modulated by developmental support and maternal care. These translational findings lead to an integrated hypothesis: high levels of early life trauma lead to disease through the developmental interaction of genetic variants with neural circuits that regulate emotion, together mediating risk and resilience in adults. PMID:19750552

  3. Spatial heterogeneity in landscape structure influences dispersal and genetic structure: empirical evidence from a grasshopper in an agricultural landscape.

    PubMed

    Gauffre, Bertrand; Mallez, Sophie; Chapuis, Marie-Pierre; Leblois, Raphael; Litrico, Isabelle; Delaunay, Sabrina; Badenhausser, Isabelle

    2015-04-01

    Dispersal may be strongly influenced by landscape and habitat characteristics that could either enhance or restrict movements of organisms. Therefore, spatial heterogeneity in landscape structure could influence gene flow and the spatial structure of populations. In the past decades, agricultural intensification has led to the reduction in grassland surfaces, their fragmentation and intensification. As these changes are not homogeneously distributed in landscapes, they have resulted in spatial heterogeneity with generally less intensified hedged farmland areas remaining alongside streams and rivers. In this study, we assessed spatial pattern of abundance and population genetic structure of a flightless grasshopper species, Pezotettix giornae, based on the surveys of 363 grasslands in a 430-km² agricultural landscape of western France. Data were analysed using geostatistics and landscape genetics based on microsatellites markers and computer simulations. Results suggested that small-scale intense dispersal allows this species to survive in intensive agricultural landscapes. A complex spatial genetic structure related to landscape and habitat characteristics was also detected. Two P. giornae genetic clusters bisected by a linear hedged farmland were inferred from clustering analyses. This linear hedged farmland was characterized by high hedgerow and grassland density as well as higher grassland temporal stability that were suspected to slow down dispersal. Computer simulations demonstrated that a linear-shaped landscape feature limiting dispersal could be detected as a barrier to gene flow and generate the observed genetic pattern. This study illustrates the relevance of using computer simulations to test hypotheses in landscape genetics studies. PMID:25773398

  4. Migration of additive molecules in a polymer filament obtained by melt spinning: Influence of the fiber processing steps

    SciTech Connect

    Gesta, E.; Skovmand, O.; Espuche, E. Fulchiron, R.

    2015-12-17

    The purpose of this study is to understand the influence of the yarn processing on the migration of additives molecules, especially insecticide, within polyethylene (PE) yarns. Yarns were manufactured in the laboratory focusing on three key-steps (spinning, post-stretching and heat-setting). Influence of each step on yarn properties was investigated using tensile tests, differential scanning calorimetry and wide-angle X-ray diffraction. The post-stretching step was proved to be critical in defining yarn mechanical and structural properties. Although a first orientation of polyethylene crystals was induced during spinning, the optimal orientation was only reached by post-stretching. The results also showed that the heat-setting did not significantly change these properties. The presence of additives crystals at the yarn surface was evidenced by scanning-electron microscopy. These studies performed at each yarn production step allowed a detailed analysis of the additives’ ability to migrate. It is concluded that while post-stretching decreased the migration rate, heat-setting seems to boost this migration.

  5. Influence of sulfur addition and S-induced wall catalytic effect on C-C bond cleavage and aromatics hydrogenation

    SciTech Connect

    Schmidt, E.; Song, C.; Schobert, H.H.

    1995-12-31

    Catalytic hydrocracking of 4-(-1-naphthylmethyl)bibenzyl NMBB predominately yielded naphthalene and 4-methylbibenzyl. Sulfur addition to most catalyst precursors lead to substantially higher catalyst activity and subsequently higher conversion. In order to clarify the effect of sulfur alone on model compound conversion, NMBB was treated with sulfur in concentrations of 1.2 to 3.4 wt%, corresponding to conditions present in catalytic runs with sulfur. It was found that increasing sulfur concentrations leads to higher NMBB conversion. Furthermore, sulfur had a permanent influence on the reactor walls. It reacted with the transition metals in the steel to form a microscopic black iron sulfide layer on the surface, which could not be removed mechanically. The {open_quotes}non catalytic{close_quotes} runs after experiments with added sulfur yielded higher conversion than normal runs with new reactors. This {open_quotes}wall catalytic effect{close_quotes} can be reduced by treating sulfided reactors with hydrochloric acid for a short period of time and subsequent immersing into a base bath over night. These results demonstrate the significant influence of sulfur addition and S-induced residual wall-effect on C-C bond cleavage and hydrogenation of aromatics in batch reactors.

  6. Influence of sulfur addition and S-induced wall catalytic effects on C-C bond cleavage and aromatics hydrogenation

    SciTech Connect

    Schmidt, E.; Song, Chunshan; Schobert, H.H.

    1995-12-31

    Catalytic hydrocracking of 4-(1-naphthylmethyl)bibenzyl, designated as NMBB, predominately yielded naphthalene and 4-methylbibenzyl. Sulfur addition to most catalyst precursors lead to substantially higher catalyst activity and subsequently higher conversion. NMBB was also treated with sulfur alone in the absence of catalysts in concentrations of 1.2 to 3.4 wt, corresponding to conditions present in catalytic runs with added sulfur to precursors. It was found that increasing sulfur concentrations lead to higher NMBB conversion. Furthermore, sulfur had a permanent influence on the reactor walls. It reacted with the transition metals in the stainless steel to form a microscopic black iron sulfide layer on the surface, which could not be removed mechanically. The {open_quotes}non-catalytic{close_quotes} runs which were done after experiments with added sulfur yielded higher conversions than normal runs done in new reactors. This {open_quotes}wall catalytic effect{close_quotes} can be reduced by treating sulfided reactors with hydrochloric acid for a short period of time and subsequent immersing into a base bath overnight. These results demonstrate the significant influence of sulfur addition and S-induced residual wall-effect on C-C bond cleavage and hydrogenation of aromatics in batch reactors.

  7. Experimental study on the characteristics of ventilated cavitation around an underwater navigating body influenced by turbulent drag-reducing additives

    NASA Astrophysics Data System (ADS)

    Jiang, ChenXing; Li, FengChen

    2015-09-01

    In this study, a new control strategy for turbulent drag reduction involving ventilated cavitation is proposed. The configurational and hydrodynamic characteristics of ventilated cavities influenced by turbulent drag-reducing additives were experimentally studied in water tunnel. The test model was fixed in the water tunnel by a strut in the aft-part. Aqueous solutions of CTAC/NaSal (cetyltrimethyl ammonium chloride/sodium salicylate) with weight concentrations of 100, 200, 400 and 600 ppm (part per million), respectively, were injected into the ventilated air cavity from the edge of the cavitator with accurate control by an injection pump. The cavity configurations were recorded by a high-speed CCD camera. The hydrodynamic characteristics of the test model were measured by a six-component balance. Experimental results show that, within the presently tested cases, the lengths of cavity influenced by drag-reducing solution are smaller than normal condition (ventilated cavity) in water, but the asymmetry of the cavity is improved. The drag resisted by the test model is reduced dramatically (the maximum drag reduction can reach to 80%) and the re-entrant jet is more complex after the CTAC solution is injected into the cavity. Turbulent drag-reducing additives have the potential in enhancement of supercavitating asymmetry and further drag reduction.

  8. General and Specific Predictors of Nicotine and Alcohol Dependence in Early Adulthood: Genetic and Environmental Influences

    PubMed Central

    Samek, Diana R; Keyes, Margaret A; Hicks, Brian M; Bailey, Jennifer; McGue, Matt; Iacono, William G

    2014-01-01

    Objective: This study builds on previous work delineating a hierarchical model of family environmental risk in relation to a hierarchical model of externalizing disorders (EXTs) by evaluating for gene–environment interplay in these relationships. The associations between parent–child relationship quality (conflict, bonding, and management) and substance-specific adolescent family environments (parental/sibling tobacco/alcohol use) in relation to young adult EXTs (age ∼22 years nicotine, alcohol, and other drug dependence; antisocial and risky sexual behavior) were evaluated. Method: The sample included 533 adopted offspring and 323 biological offspring. Because adopted youth do not share genes with their parents, a significant association between parent–child relationship quality and EXTs would provide evidence against passive gene–environment correlation (rGE). Significant associations between parental tobacco/alcohol use in relation to offspring nicotine/alcohol dependence in the adopted offspring support common environmental influence. Significant associations detected for the biological offspring only suggest common genetic influence. Results: For both adoptive and biological offspring, there was a significant association between parent–child relationship quality and EXTs. Parental tobacco/alcohol use was unrelated to EXTs. Sibling tobacco/alcohol use was related to EXTs, but only for the biological siblings. Parental tobacco use was associated with the residual variance in nicotine dependence in adopted offspring. Conclusions: Findings replicate a long-term influence of adolescent parent–child relationship quality on adult EXTs. Findings extend previous research by providing evidence against passive rGE in this association. The association between parental tobacco use and adult nicotine dependence appears to be environmentally mediated, but caution is warranted as we found this relationship only for adopted youth. PMID:24988261

  9. The Limits of Genetic Influence: A Behavior-Genetic Analysis of Infant-Caregiver Relationship Quality and Temperament

    ERIC Educational Resources Information Center

    Roisman, Glenn I.; Fraley, R. Chris

    2006-01-01

    This report presents data on 9-month-old twin pairs (n[MZ]=172; n[DZ]=333) from the Early Childhood Longitudinal Study, demonstrating that the role of genetic variation among infants is trivial and the shared and nonshared environment is substantial in accounting for the observed quality of infant-caregiver relationships. In contrast, maternal…

  10. No Clear Genetic Influences on the Association between Dyslexia and Anxiety in a Population-Based Sample of Female Twins

    ERIC Educational Resources Information Center

    Whitehouse, Andrew J. O.; Spector, Tim D.; Cherkas, Lynn F.

    2009-01-01

    Individuals with dyslexia are at an increased risk for anxiety disorders (e.g. generalized anxiety disorder, stress disorders, panic disorder). The extent to which this association is mediated by genetic and/or environmental influences is unclear. The current study explored the relationship between these two phenotypes using a large…

  11. Early Adverse Environments and Genetic Influences on Age at First Sex: Evidence for Gene × Environment Interaction

    ERIC Educational Resources Information Center

    Carlson, Marie D.; Mendle, Jane; Harden, K. Paige

    2014-01-01

    Youth who experience adverse environments in early life initiate sexual activity at a younger age, on average, than those from more advantaged circumstances. Evolutionary theorists have posited that ecological stress precipitates earlier reproductive and sexual onset, but it is unclear how stressful environments interact with genetic influences on…

  12. Glucokinase regulatory proten genetic variant interacts with omega-3 PUFA to influence insulin resistance and inflammation in metabolic syndrome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucokinase Regulatory Protein (GCKR) plays a central role regulating both hepatic triglyceride and glucose metabolism. Fatty acids are key metabolic regulators, which interact with genetic factors and influence glucose metabolism and other metabolic traits. Omega-3 polyunsaturated fatty acids (n-3...

  13. Genetic and environmental influences on eating behavior - a study of twin pairs reared apart or reared together

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study examined the relative influence of genetic versus environmental factors on specific aspects of eating behavior. Adult monozygotic twins (22 pairs and 3 singleton reared apart, 38 pairs and 9 singleton reared together, age 18-76 years, BMI 17-43 kg/m2) completed the Three Factor Eating Que...

  14. An Understanding of How Peer, Genetic, and Environmental Influences Can Motivate Terrorists or Ordinary People to Kill Themselves and Others

    ERIC Educational Resources Information Center

    Lavoie-Perusse, Simon

    2009-01-01

    The purpose of this research paper is to find a correlation between peer, genetic, and environmental influences and the behavior and personality development during childhood. This study focuses on the 1999 Columbine High School Massacre to try to explain certain kinds of behavior. The study made on 275 freshmen at Cornell University showed that…

  15. Genetic Influences on Anxiety in Children: What We've Learned and where We're Heading

    ERIC Educational Resources Information Center

    Gregory, Alice M.; Eley, Thalia C.

    2007-01-01

    Anxiety is a common problem, typically beginning early in life. This article explores reasons for individual differences in levels of anxiety among children, by reviewing the genetic literature. The plethora of research to date has demonstrated clearly that both genes and environmental influences play important roles in explaining differences in…

  16. Genetic and Environmental Influences on Prereading Skills and Early Reading and Spelling Development in the United States, Australia, and Scandinavia

    ERIC Educational Resources Information Center

    Samuelsson, Stefan; Olson, Richard; Wadsworth, Sally; Corley, Robin; DeFries, John C.; Willcutt, Erik; Hulslander, Jacqueline; Byrne, Brian

    2007-01-01

    Genetic and environmental influences on prereading skills in preschool and on early reading and spelling development at the end of kindergarten were compared among samples of identical and fraternal twins from the U.S. (Colorado), Australia, and Scandinavia. Mean comparisons revealed significantly lower preschool print knowledge in Scandinavia,…

  17. Genetic and environmental influences on individual differences in emotion regulation and its relation to working memory in toddlerhood.

    PubMed

    Wang, Manjie; Saudino, Kimberly J

    2013-12-01

    This is the first study to explore genetic and environmental contributions to individual differences in emotion regulation in toddlers, and the first to examine the genetic and environmental etiology underlying the association between emotion regulation and working memory. In a sample of 304 same-sex twin pairs (140 MZ, 164 DZ) at age 3, emotion regulation was assessed using the Behavior Rating Scale of the Bayley Scales of Infant Development (BRS; Bayley, 1993), and working memory was measured by the visually cued recall (VCR) task (Zelazo, Jacques, Burack, & Frye, 2002) and several memory tasks from the Mental Scale of the BSID. Based on model-fitting analyses, both emotion regulation and working memory were significantly influenced by genetic and nonshared environmental factors. Shared environmental effects were significant for working memory, but not for emotion regulation. Only genetic factors significantly contributed to the covariation between emotion regulation and working memory. PMID:24098922

  18. Genetic Variation Throughout the Folate Metabolic Pathway Influences Negative Symptom Severity in Schizophrenia

    PubMed Central

    Roffman, Joshua L.; Brohawn, David G.; Nitenson, Adam Z.; Macklin, Eric A.; Smoller, Jordan W.; Goff, Donald C.

    2013-01-01

    Low serum folate levels previously have been associated with negative symptom risk in schizophrenia, as has the hypofunctional 677C>T variant of the MTHFR gene. This study examined whether other missense polymorphisms in folate-regulating enzymes, in concert with MTHFR, influence negative symptoms in schizophrenia, and whether total risk allele load interacts with serum folate status to further stratify negative symptom risk. Medicated outpatients with schizophrenia (n = 219), all of European origin and some included in a previous report, were rated with the Positive and Negative Syndrome Scale. A subset of 82 patients also underwent nonfasting serum folate testing. Patients were genotyped for the MTHFR 677C>T (rs1801133), MTHFR 1298A>C (rs1801131), MTR 2756A>G (rs1805087), MTRR 203A>G (rs1801394), FOLH1 484T>C (rs202676), RFC 80A>G (rs1051266), and COMT 675G>A (rs4680) polymorphisms. All genotypes were entered into a linear regression model to determine significant predictors of negative symptoms, and risk scores were calculated based on total risk allele dose. Four variants, MTHFR 677T, MTR 2756A, FOLH1 484C, and COMT 675A, emerged as significant independent predictors of negative symptom severity, accounting for significantly greater variance in negative symptoms than MTHFR 677C>T alone. Total allele dose across the 4 variants predicted negative symptom severity only among patients with low folate levels. These findings indicate that multiple genetic variants within the folate metabolic pathway contribute to negative symptoms of schizophrenia. A relationship between folate level and negative symptom severity among patients with greater genetic vulnerability is biologically plausible and suggests the utility of folate supplementation in these patients. PMID:22021659

  19. Genetic variation in the serotonin transporter gene influences ERP old/new effects during recognition memory.

    PubMed

    Ross, Robert S; Medrano, Paolo; Boyle, Kaitlin; Smolen, Andrew; Curran, Tim; Nyhus, Erika

    2015-11-01

    Recognition memory is defined as the ability to recognize a previously encountered stimulus and has been associated with spatially and temporally distinct event-related potentials (ERPs). Allelic variations of the serotonin transporter gene (SLC6A4) have recently been shown to impact memory performance. Common variants of the serotonin transporter-linked polymorphic region (5HTTLPR) of the SLC6A4 gene result in long (l) and short (s) allelic variants with carriers of the s allele having lowered transcriptional efficiency. Thus, the current study examines the effects polymorphisms of the SLC6A4 gene have on performance and ERP amplitudes commonly associated with recognition memory. Electroencephalogram (EEG), genetic, and behavioral data were collected from sixty participants as they performed an item and source memory recognition task. In both tasks, participants studied and encoded 200 words, which were then mixed with 200 new words during retrieval. Participants were monitored with EEG during the retrieval portion of each memory task. EEG electrodes were grouped into four ROIs, left anterior superior, right anterior superior, left posterior superior, and right posterior superior. ERP mean amplitudes during hits in the item and source memory task were compared to correctly recognizing new items (correct rejections). Results show that s-carriers have decreased mean hit amplitudes in both the right anterior superior ROI 1000-1500ms post stimulus during the source memory task and the left anterior superior ROI 300-500ms post stimulus during the item memory task. These results suggest that individual differences due to genetic variation of the serotonin transporter gene influences recognition memory. PMID:26423665

  20. Vitamins, stress and growth: the availability of antioxidants in early life influences the expression of cryptic genetic variation.

    PubMed

    Kim, S-Y; Noguera, J C; Tato, A; Velando, A

    2013-06-01

    Environmental inputs during early development can shape the expression of phenotypes, which has long-lasting consequences in physiology and life history of an organism. Here, we study whether experimentally manipulated availability of dietary antioxidants, vitamins C and E, influences the expression of genetic variance for antioxidant defence, endocrine signal and body mass in yellow-legged gull chicks using quantitative genetic models based on full siblings. Our experimental study in a natural population reveals that the expression of genetic variance in total antioxidant capacity in plasma increased in chicks supplemented with vitamins C and E despite the negligible effects on the average phenotype. This suggests that individuals differ in their ability to capture and transport dietary antioxidants or to respond to these extra resources, and importantly, this ability has a genetic basis. Corticosterone level in plasma and body mass were negatively correlated at the phenotypic level. Significant genetic variance of corticosterone level appeared only in control chicks nonsupplemented with vitamins, suggesting that the genetic variation of endocrine system, which transmits environmental cues to adaptively control chick development, appeared in stressful conditions (i.e. poor antioxidant availability). Therefore, environmental inputs may shape evolutionary trajectories of antioxidant capacity and endocrine system by affecting the expression of cryptic genetic variation. PMID:23517061

  1. Understanding Influence of MoSi2 Addition (5 Weight Percent) on Tribological Properties of TiB2

    NASA Astrophysics Data System (ADS)

    Mukhopadhyay, Amartya; Raju, G. B.; Basu, Bikramjit

    2008-12-01

    In densifying engineering ceramics such as TiB2 using nonmetallic sinter additives, it is important to assess the influence of the addition of sinter-aid on the properties of TiB2. The present article reports how a small addition of MoSi2 (5 wt pct) sinter-aid enhances the wear resistance of TiB2 at mode-I fretting contact. This has been confirmed using a series of unlubricated wear tests on hot-pressed ceramics using two different counterbodies, viz. bearing steel and WC-6 wt pct Co cemented carbide, under identical testing conditions. Steady-state coefficient of friction (COF) against steel counterbody has been found to noticeably vary in the range of 0.5 to 1, with variation in load or MoSi2 addition. However, insignificant variation in COF (˜0.5) has been recorded during fretting against WC-Co. Furthermore, lower wear rate (˜10-6 mm3/Nm) is measured against the cemented carbide, as compared to that against steel (˜10-5 mm3/Nm). It has been observed that the material removal of TiB2-based ceramics against steel involves tribochemical wear as well as abrasive wear, and the occurrence of tribochemical wear is explained in terms of various feasible reactions at the tribological interface. Lower contact area, resulting in reduced adhesive wear, along with the absence of additional tribochemical wear, has been attributed to lower wear rate as observed after fretting against the harder (WC-Co) counterbody. A number of possible reactions along with their thermodynamic feasibility are discussed to explain the tribochemical wear at the interface of the mating couple. Irrespective of counterbody or material composition, the measured wear volume exhibits linear dependency on abrasion parameter, confirming the role of material parameters on the contribution of abrasive wear to the material removal/damage of the investigated materials.

  2. Genetic diversity in Capsicum baccatum is significantly influenced by its ecogeographical distribution

    PubMed Central

    2012-01-01

    Background The exotic pepper species Capsicum baccatum, also known as the aji or Peruvian hot pepper, is comprised of wild and domesticated botanical forms. The species is a valuable source of new genes useful for improving fruit quality and disease resistance in C. annuum sweet bell and hot chile pepper. However, relatively little research has been conducted to characterize the species, thus limiting its utilization. The structure of genetic diversity in a plant germplasm collection is significantly influenced by its ecogeographical distribution. Together with DNA fingerprints derived from AFLP markers, we evaluated variation in fruit and plant morphology of plants collected across the species native range in South America and evaluated these characters in combination with the unique geography, climate and ecology at different sites where plants originated. Results The present study mapped the ecogeographic distribution, analyzed the spatial genetic structure, and assessed the relationship between the spatial genetic pattern and the variation of morphological traits in a diverse C. baccatum germplasm collection spanning the species distribution. A combined diversity analysis was carried out on the USDA-ARS C. baccatum germplasm collection using data from GIS, morphological traits and AFLP markers. The results demonstrate that the C. baccatum collection covers wide geographic areas and is adapted to divergent ecological conditions in South America ranging from cool Andean highland to Amazonia rainforest. A high level of morphological diversity was evident in the collection, with fruit weight the leading variable. The fruit weight distribution pattern was compatible to AFLP-based clustering analysis for the collection. A significant spatial structure was observed in the C. baccatum gene pool. Division of the domesticated germplasm into two major regional groups (Western and Eastern) was further supported by the pattern of spatial population structure. Conclusions

  3. Numerical study on the influence of hydrogen addition on soot formation in a laminar ethylene-air diffusion flame

    SciTech Connect

    Guo, Hongsheng; Liu, Fengshan; Smallwood, Gregory J.; Guelder, OEmer L.

    2006-04-15

    The influence of hydrogen addition to the fuel of an atmosphere pressure coflow laminar ethylene-air diffusion flame on soot formation was studied by numerical simulation. A detailed gas-phase reaction mechanism, which includes aromatic chemistry up to four rings, and complex thermal and transport properties were used. The fully coupled elliptic governing equations were solved. The interactions between soot and gas-phase chemistry were taken into account. Radiation heat transfer from CO{sub 2}, CO, H{sub 2}O, and soot was calculated using the discrete-ordinates method coupled to a statistical narrow-band-correlated K-based wide-band model. The predicted results were compared with the available experimental data and analyzed. It is indicated that the addition of hydrogen to the fuel in an ethylene-air diffusion flame suppresses soot formation through the effects of dilution and chemistry. This result is in agreement with available experiments. The simulations further suggest that the chemically inhibiting effect of hydrogen addition on soot formation is due to the decrease of hydrogen atom concentration in soot surface growth regions and higher concentration of molecular hydrogen in the lower flame region. (author)

  4. Addition of antibacterial agents to MMA-TBB dentin bonding systems--influence on tensile bond strength and antibacterial effect.

    PubMed

    Kudou, Y; Obara, K; Kawashima, T; Kubota, M; Abe, S; Endo, T; Komatsu, M; Okuda, R

    2000-03-01

    To produce a bonding system which has both high bond strength and antibacterial properties, an antibacterial agent (vancomycin: VCM or metronidazol: MN) was added to the PMMA powder of 4-META/MMA-TBB resin (CB). The influence of the addition of an antibacterial agent on tensile bond strength to dentin and the antibacterial effect were investigated in this study. Forty-seven freshly extracted bovine first or second incisors were used to measure the tensile bond strength to dentin. The bond strengths to bovine dentin were not significantly decreased by addition of VCM (1%, 2%, 5%), or MN (1%) to CB (p < 0.05). The antibacterial effect of CB containing antibacterial agent on six strains of bacteria was investigated by the agar plate diffusion method, analyzing the appearance of the inhibition zone around a resin disk following anaerobic culturing. The resin disks containing VCM showed antibacterial effects on all of the strains examined; the widths of the inhibition zones were 4-15 mm. The resin disks containing MN showed antibacterial effects on three strains; the widths of the inhibition zones were 0-4 mm. It was thus possible to produce a bonding system with both antibacterial effect and high tensile bond strength by addition of VCM to PMMA powder. PMID:11219091

  5. Influence of antibiotics used as feed additives on the immune effect of erysipelas live vaccine in swine.

    PubMed

    Yamamoto, K; Takagi, M; Endoh, Y S; Kijima, M; Takahashi, T

    2000-08-01

    To investigate the influence of antibiotics used as feed additives on the immune response to erysipelas live vaccine, the pig inoculation test was applied. Avilamycin, oxytetracycline quaternary salt, enramycin, virginiamycin and tylosin phosphate were selected as test antibiotics. Five experimental feeds containing each antibiotic at the highest concentration permitted for feed additives in Japan, and the basal diet lacking antibiotics were examined. Twenty-nine pigs were divided into six groups. At first all the groups were fed with the antibiotic-free basal diet for 7 days, and then each group received the experimental feeds. On the 14th day after feeding with test feeds all the pigs, except for one control pig in each group, were immunized with the vaccine and all the pigs were then challenge-exposed to a virulent strain of Erysipelothrix rhusiopathiae 14 days after vaccination. The clinical response was observed every day for 14 days. In all the groups, most of the vaccinated pigs did not develop any clinical signs of acute erysipelas after the challenge exposure, whereas non-vaccinated control pigs died or showed severe generalized erythema with profound depression and anorexia. No differences in the protection against the challenge exposure were observed among the groups. Therefore, the present results suggest that these selected antibiotics would not interfere with the immune effect of the vaccine if given at the usual concentrations used for feed additives. PMID:11014067

  6. Different outcomes, same etiology? Shared genetic and environmental influences on non-suicidal self injury and suicidal ideation

    PubMed Central

    Maciejewski, Dominique F.; Creemers, Hanneke; Lynskey, Michael T.; Madden, Pamela A.F.; Heath, Andrew C.; Statham, Dixie J.; Martin, Nicholas G.; Verweij, Karin J.H.

    2014-01-01

    Importance Non-suicidal and suicidal self-injury are very harmful behaviours and are associated with several psychiatric disorders. In the recently developed 5th version of the DSM, non-suicidal self-injury and suicidal behaviour disorder are for the first time introduced as conditions in their own right, instead of symptoms of other psychiatric disorders. It is unclear to what extent non-suicidal and suicidal self-injurious behaviours share the same underlying biological mechanisms and are influenced by the same environmental factors. Objective To determine the relative importance of genetic and environmental influences on the variation in non-suicidal self-injury and suicidal ideation and their covariation. Design Classical twin design, using population-based twin sample in which twins participated in semi-structured telephone interviews between 1996 and 2009 which primarily focused on psychiatric disorders. Setting General community. Participants 10678 male and female Australian adult twins (mean age 32.8 years). Main Outcome Measures Lifetime presence of self-reported non-suicidal self-injury (NSSI) and suicidal ideation. Results The prevalence of NSSI and suicidal ideation was 4.7% and 26.5% and individuals that engaged in self-harm were much more likely to report suicidal ideation, OR(95%CIs)=8.4 (6.8–10.3). Results from a bivariate genetic model indicated that genetic factors explain a substantial part of the variance in both NSSI (37% for males and 59% for females) and suicidal ideation (41% and 55%, respectively), while residual influences (including nonshared environmental influences and measurement error) explain the remainder of the variance. Shared (family) environment did not seem to play a role. Moreover, both behaviours were strongly correlated (r=0.49 for males and 0.61 for females) and this correlation was largely explained by overlapping genetic influences (62% and 76% for males and females, respectively), whereas residual influences accounted

  7. Parent, sibling and peer influences on smoking initiation, regular smoking and nicotine dependence. Results from a genetically informative design.

    PubMed

    Scherrer, Jeffrey F; Xian, Hong; Pan, Hui; Pergadia, Michele L; Madden, Pamela A F; Grant, Julia D; Sartor, Carolyn E; Haber, Jon Randolph; Jacob, Theodore; Bucholz, Kathleen K

    2012-03-01

    We sought to determine whether parenting, sibling and peer influences are associated with offspring ever smoking, regular smoking and nicotine dependence (ND) after controlling for familial factors. We used a twin-family design and data from structured diagnostic surveys of 1919 biological offspring (ages 12-32 years), 1107 twin fathers, and 1023 mothers. Offspring were classified into one of four familial risk groups based on twin fathers' and their co-twins' history of DSM-III-R nicotine dependence. Multivariate multinomial logistic regression was used to model familial risk, paternal and maternal parenting behavior and substance use, sibling substance use, and friend and school peer smoking, alcohol and drug use. Ever smoking was associated with increasing offspring age, white race, high maternal pressure to succeed in school, sibling drug use, and friend smoking, alcohol and drug use. Offspring regular smoking was associated with these same factors with additional contribution from maternal ND. Offspring ND was associated with increasing offspring age, male gender, biological parents divorce, high genetic risk from father and mother ND, maternal problem drinking, maternal rule inconsistency and sibling drug use, and friend smoking, alcohol and drug use. Friend smoking had the largest magnitude of association with offspring smoking. This effect remains after accounting for familial liability and numerous parent and sibling level effects. Smoking interventions may have greatest impact by targeting smoking prevention among peer groups in adolescent and young adult populations. PMID:22094168

  8. 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

  9. 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

  10. Influences of Bi 2O 3 additive on the microstructure, permeability, and power loss characteristics of Ni-Zn ferrites

    NASA Astrophysics Data System (ADS)

    Su, Hua; Tang, Xiaoli; Zhang, Huaiwu; Jia, Lijun; Zhong, Zhiyong

    2009-10-01

    Nickel-zinc ferrite materials containing different Bi 2O 3 concentrations have been prepared by the conventional ceramic technique. Micrographs have clearly revealed that the Bi 2O 3 additive promoted grain growth. When the Bi 2O 3 content reached 0.15 wt%, a dual microstructure with both small grains (<5 μm) and some extremely large grains (>50 μm) appeared. With higher Bi 2O 3 content, the samples exhibited a very large average grain size of more than 30 μm. The initial permeability gradually decreased with increasing Bi 2O 3 content. When the Bi 2O 3 content exceeded 0.15 wt%, the permeability gradually decreased with frequency due to the low-frequency resonance induced by the large grain size. Neither the sintering density nor the saturation magnetization was obviously influenced by the Bi 2O 3 content or microstructure of the samples. However, power loss (Pcv) characteristics were evidently influenced. At low flux density, the sample with 0.10 wt% Bi 2O 3, which was characterized by an average grain size of 3-4 μm and few closed pores, displayed the lowest Pcv, irrespective of frequency. When the flux density was equal to or greater than the critical value of 40 mT, the sample with 0.20 wt% Bi 2O 3, which had the largest average grain size, displayed the lowest Pcv.

  11. Influence of Addition of Nb on Phase Transformation, Microstructure and Mechanical Properties of Equiatomic NiTi SMA

    NASA Astrophysics Data System (ADS)

    Jiang, Shuyong; Liang, Yulong; Zhang, Yanqiu; Zhao, Yanan; Zhao, Chengzhi

    2016-08-01

    Three novel NiTiNb shape memory alloys, which possess a nominal chemical composition of Ni50-x/2-Ti50-x/2-Nb x (at.%) where x stands for 2, 4 and 6, respectively, were designed in order to investigate the influence of the addition of Nb on phase transformation, microstructure and mechanical properties of equiatomic NiTi shape memory alloy. All the three NiTiNb shape memory alloys contain B2 austenite phase, B19' martensite phase and β-Nb precipitate phase. Martensite type II twin can be observed in the case of Ni49Ti49Nb2 alloy. In the case of Ni48Ti48Nb4 alloy, there exists a boundary between Ti2Ni precipitate phase and β-Nb precipitate phase. As for Ni47Ti47Nb6 alloy, it can be observed that there exists an orientation relationship of [01bar{1}]_{{β{{ - Nb}}}} //[01bar{1}]_{{B2}} between β-Nb precipitate phase and B2 austenite matrix. The increase in Nb content contributes to enhancing the yield stress of NiTiNb shape memory alloy, but it leads to the decrease in compression fracture stress. The addition of Nb to equiatomic NiTi shape memory alloy does not have a significant influence on the transformation hysteresis of the alloy, which is attributed to the fact that NiTiNb shape memory alloy is not subjected to plastic deformation and hence β-Nb precipitate phase is unable to relax the elastic strain in the martensite interface.

  12. Sensation seeking, peer deviance, and genetic influences on adolescent delinquency: Evidence for person-environment correlation and interaction.

    PubMed

    Mann, Frank D; Patterson, Megan W; Grotzinger, Andrew D; Kretsch, Natalie; Tackett, Jennifer L; Tucker-Drob, Elliot M; Harden, K Paige

    2016-07-01

    Both sensation seeking and affiliation with deviant peer groups are risk factors for delinquency in adolescence. In this study, we use a sample of adolescent twins (n = 549), 13 to 20 years old (M age = 15.8 years), in order to test the interactive effects of peer deviance and sensation seeking on delinquency in a genetically informative design. Consistent with a socialization effect, affiliation with deviant peers was associated with higher delinquency even after controlling for selection effects using a co-twin-control comparison. At the same time, there was evidence for person-environment correlation; adolescents with genetic dispositions toward higher sensation seeking were more likely to report having deviant peer groups. Genetic influences on sensation seeking substantially overlapped with genetic influences on adolescent delinquency. Finally, the environmentally mediated effect of peer deviance on adolescent delinquency was moderated by individual differences in sensation seeking. Adolescents reporting high levels of sensation seeking were more susceptible to deviant peers, a Person × Environment interaction. These results are consistent with both selection and socialization processes in adolescent peer relationships, and they highlight the role of sensation seeking as an intermediary phenotype for genetic risk for delinquency. (PsycINFO Database Record PMID:27124714

  13. Genetic modifiers of sickle cell anemia in the BABY HUG cohort: influence on laboratory and clinical phenotypes.

    PubMed

    Sheehan, Vivien A; Luo, Zhaoyu; Flanagan, Jonathan M; Howard, Thad A; Thompson, Bruce W; Wang, Winfred C; Kutlar, Abdullah; Ware, Russell E

    2013-07-01

    The recently completed BABY HUG trial investigated the safety and efficacy of hydroxyurea in infants with sickle cell anemia (SCA). To investigate the effects of known genetic modifiers, genomic DNA on 190 randomized subjects were analyzed for alpha thalassemia, beta-globin haplotype, polymorphisms affect