WorldWideScience

Sample records for investigating gene-environment interactions

  1. Parental divorce and disordered eating: an investigation of a gene-environment interaction.

    Science.gov (United States)

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

    2011-03-01

    We investigated gene-environment interactions (GxE) for associations between parental divorce and disordered eating (DE). Participants were 1,810 female twins from the Michigan State University Twin Registry and the Minnesota Twin Family Study. The Minnesota Eating Behaviors Survey was used to assess DE. We tested for GxE by comparing the heritability of DE in twins from divorced versus intact families. It was hypothesized that divorce would moderate the heritability of DE, in that heritability would be higher in twins from divorced than twins from intact families. As expected, the heritability of body dissatisfaction was significantly higher in twins from divorced than intact families. However, genetic influences were equal in twins from divorced and intact families for all other forms of DE. Although divorce did not moderate heritability of most DE symptoms, future research should replicate GxEs for body dissatisfaction and identify factors underlying this unique relationship. Copyright © 2010 Wiley Periodicals, Inc.

  2. Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations.

    Science.gov (United States)

    van Os, Jim; Rutten, Bart P; Myin-Germeys, Inez; Delespaul, Philippe; Viechtbauer, Wolfgang; van Zelst, Catherine; Bruggeman, Richard; Reininghaus, Ulrich; Morgan, Craig; Murray, Robin M; Di Forti, Marta; McGuire, Philip; Valmaggia, Lucia R; Kempton, Matthew J; Gayer-Anderson, Charlotte; Hubbard, Kathryn; Beards, Stephanie; Stilo, Simona A; Onyejiaka, Adanna; Bourque, Francois; Modinos, Gemma; Tognin, Stefania; Calem, Maria; O'Donovan, Michael C; Owen, Michael J; Holmans, Peter; Williams, Nigel; Craddock, Nicholas; Richards, Alexander; Humphreys, Isla; Meyer-Lindenberg, Andreas; Leweke, F Markus; Tost, Heike; Akdeniz, Ceren; Rohleder, Cathrin; Bumb, J Malte; Schwarz, Emanuel; Alptekin, Köksal; Üçok, Alp; Saka, Meram Can; Atbaşoğlu, E Cem; Gülöksüz, Sinan; Gumus-Akay, Guvem; Cihan, Burçin; Karadağ, Hasan; Soygür, Haldan; Cankurtaran, Eylem Şahin; Ulusoy, Semra; Akdede, Berna; Binbay, Tolga; Ayer, Ahmet; Noyan, Handan; Karadayı, Gülşah; Akturan, Elçin; Ulaş, Halis; Arango, Celso; Parellada, Mara; Bernardo, Miguel; Sanjuán, Julio; Bobes, Julio; Arrojo, Manuel; Santos, Jose Luis; Cuadrado, Pedro; Rodríguez Solano, José Juan; Carracedo, Angel; García Bernardo, Enrique; Roldán, Laura; López, Gonzalo; Cabrera, Bibiana; Cruz, Sabrina; Díaz Mesa, Eva Ma; Pouso, María; Jiménez, Estela; Sánchez, Teresa; Rapado, Marta; González, Emiliano; Martínez, Covadonga; Sánchez, Emilio; Olmeda, Ma Soledad; de Haan, Lieuwe; Velthorst, Eva; van der Gaag, Mark; Selten, Jean-Paul; van Dam, Daniella; van der Ven, Elsje; van der Meer, Floor; Messchaert, Elles; Kraan, Tamar; Burger, Nadine; Leboyer, Marion; Szoke, Andrei; Schürhoff, Franck; Llorca, Pierre-Michel; Jamain, Stéphane; Tortelli, Andrea; Frijda, Flora; Vilain, Jeanne; Galliot, Anne-Marie; Baudin, Grégoire; Ferchiou, Aziz; Richard, Jean-Romain; Bulzacka, Ewa; Charpeaud, Thomas; Tronche, Anne-Marie; De Hert, Marc; van Winkel, Ruud; Decoster, Jeroen; Derom, Catherine; Thiery, Evert; Stefanis, Nikos C; Sachs, Gabriele; Aschauer, Harald; Lasser, Iris; Winklbaur, Bernadette; Schlögelhofer, Monika; Riecher-Rössler, Anita; Borgwardt, Stefan; Walter, Anna; Harrisberger, Fabienne; Smieskova, Renata; Rapp, Charlotte; Ittig, Sarah; Soguel-dit-Piquard, Fabienne; Studerus, Erich; Klosterkötter, Joachim; Ruhrmann, Stephan; Paruch, Julia; Julkowski, Dominika; Hilboll, Desiree; Sham, Pak C; Cherny, Stacey S; Chen, Eric Y H; Campbell, Desmond D; Li, Miaoxin; Romeo-Casabona, Carlos María; Emaldi Cirión, Aitziber; Urruela Mora, Asier; Jones, Peter; Kirkbride, James; Cannon, Mary; Rujescu, Dan; Tarricone, Ilaria; Berardi, Domenico; Bonora, Elena; Seri, Marco; Marcacci, Thomas; Chiri, Luigi; Chierzi, Federico; Storbini, Viviana; Braca, Mauro; Minenna, Maria Gabriella; Donegani, Ivonne; Fioritti, Angelo; La Barbera, Daniele; La Cascia, Caterina Erika; Mulè, Alice; Sideli, Lucia; Sartorio, Rachele; Ferraro, Laura; Tripoli, Giada; Seminerio, Fabio; Marinaro, Anna Maria; McGorry, Patrick; Nelson, Barnaby; Amminger, G Paul; Pantelis, Christos; Menezes, Paulo R; Del-Ben, Cristina M; Gallo Tenan, Silvia H; Shuhama, Rosana; Ruggeri, Mirella; Tosato, Sarah; Lasalvia, Antonio; Bonetto, Chiara; Ira, Elisa; Nordentoft, Merete; Krebs, Marie-Odile; Barrantes-Vidal, Neus; Cristóbal, Paula; Kwapil, Thomas R; Brietzke, Elisa; Bressan, Rodrigo A; Gadelha, Ary; Maric, Nadja P; Andric, Sanja; Mihaljevic, Marina; Mirjanic, Tijana

    2014-07-01

    Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular genetic variants is small. There are now also a limited number of studies that have investigated molecular genetic candidate gene-environment interactions (G × E), however, so far, thorough replication of findings is rare and G × E research still faces several conceptual and methodological challenges. In this article, we aim to review these recent developments and illustrate how integrated, large-scale investigations may overcome contemporary challenges in G × E research, drawing on the example of a large, international, multi-center study into the identification and translational application of G × E in schizophrenia. While such investigations are now well underway, new challenges emerge for G × E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap in phenotype. © The Author 2014. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  3. Gene-environment interactions involving functional variants

    DEFF Research Database (Denmark)

    Barrdahl, Myrto; Rudolph, Anja; Hopper, John L

    2017-01-01

    .36, 95% CI: 1.16-1.59, pint  = 1.9 × 10(-5) ) in relation to ER- disease risk. The remaining two gene-environment interactions were also identified in relation to ER- breast cancer risk and were found between 3p21-rs6796502 and age at menarche (ORint  = 1.26, 95% CI: 1.12-1.43, pint =1.8 × 10...... epidemiological breast cancer risk factors in relation to breast cancer. Analyses were conducted on up to 58,573 subjects (26,968 cases and 31,605 controls) from the Breast Cancer Association Consortium, in one of the largest studies of its kind. Analyses were carried out separately for estrogen receptor (ER......) positive (ER+) and ER negative (ER-) disease. The Bayesian False Discovery Probability (BFDP) was computed to assess the noteworthiness of the results. Four potential gene-environment interactions were identified as noteworthy (BFDP 

  4. Finding gene-environment interactions for Phobias

    OpenAIRE

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

    2008-01-01

    Phobias are common disorders causing a great deal of suffering. Studies of gene-environment interaction (G × E) have revealed much about the complex processes underlying the development of various psychiatric disorders but have told us little about phobias. This article describes what is already known about genetic and environmental influences upon phobias and suggests how this information can be used to optimise the chances of discovering G × Es for phobias. In addition to the careful concep...

  5. Finding gene-environment interactions for phobias.

    Science.gov (United States)

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

    2008-03-01

    Phobias are common disorders causing a great deal of suffering. Studies of gene-environment interaction (G x E) have revealed much about the complex processes underlying the development of various psychiatric disorders but have told us little about phobias. This article describes what is already known about genetic and environmental influences upon phobias and suggests how this information can be used to optimise the chances of discovering G x Es for phobias. In addition to the careful conceptualisation of new studies, it is suggested that data already collected should be re-analysed in light of increased understanding of processes influencing phobias.

  6. Environmental confounding in gene-environment interaction studies.

    Science.gov (United States)

    Vanderweele, Tyler J; Ko, Yi-An; Mukherjee, Bhramar

    2013-07-01

    We show that, in the presence of uncontrolled environmental confounding, joint tests for the presence of a main genetic effect and gene-environment interaction will be biased if the genetic and environmental factors are correlated, even if there is no effect of either the genetic factor or the environmental factor on the disease. When environmental confounding is ignored, such tests will in fact reject the joint null of no genetic effect with a probability that tends to 1 as the sample size increases. This problem with the joint test vanishes under gene-environment independence, but it still persists if estimating the gene-environment interaction parameter itself is of interest. Uncontrolled environmental confounding will bias estimates of gene-environment interaction parameters even under gene-environment independence, but it will not do so if the unmeasured confounding variable itself does not interact with the genetic factor. Under gene-environment independence, if the interaction parameter without controlling for the environmental confounder is nonzero, then there is gene-environment interaction either between the genetic factor and the environmental factor of interest or between the genetic factor and the unmeasured environmental confounder. We evaluate several recently proposed joint tests in a simulation study and discuss the implications of these results for the conduct of gene-environment interaction studies.

  7. Animal models of gene-environment interactions in schizophrenia.

    Science.gov (United States)

    Ayhan, Yavuz; Sawa, Akira; Ross, Christopher A; Pletnikov, Mikhail V

    2009-12-07

    The pathogenesis of schizophrenia and related mental illnesses likely involves multiple interactions between susceptibility genes of small effects and environmental factors. Gene-environment interactions occur across different stages of neurodevelopment to produce heterogeneous clinical and pathological manifestations of the disease. The main obstacle for mechanistic studies of gene-environment interplay has been the paucity of appropriate experimental systems for elucidating the molecular pathways that mediate gene-environment interactions relevant to schizophrenia. Recent advances in psychiatric genetics and a plethora of experimental data from animal studies allow us to suggest a new approach to gene-environment interactions in schizophrenia. We propose that animal models based on identified genetic mutations and measurable environment factors will help advance studies of the molecular mechanisms of gene-environment interplay.

  8. Investigation of gene-environment interactions between 47 newly identified breast cancer susceptibility loci and environmental risk factors

    NARCIS (Netherlands)

    Rudolph, Anja; Milne, Roger L.; Truong, Thérèse; Knight, Julia A.; Seibold, Petra; Flesch-Janys, Dieter; Behrens, Sabine; Eilber, Ursula; Bolla, Manjeet K.; Wang, Qin; Dennis, Joe; Dunning, Alison M.; Shah, Mitul; Munday, Hannah R.; Darabi, Hatef; Eriksson, Mikael; Brand, Judith S.; Olson, Janet; Vachon, Celine M.; Hallberg, Emily; Castelao, J. Esteban; Carracedo, Angel; Torres, Maria; Li, Jingmei; Humphreys, Keith; Cordina-Duverger, Emilie; Menegaux, Florence; Flyger, Henrik; Nordestgaard, Børge G.; Nielsen, Sune F.; Yesilyurt, Betul T.; Floris, Giuseppe; Leunen, Karin; Engelhardt, Ellen G.; Broeks, Annegien; Rutgers, Emiel J.; Glendon, Gord; Mulligan, Anna Marie; Cross, Simon; Reed, Malcolm; Gonzalez-Neira, Anna; Arias Perez, José Ignacio; Provenzano, Elena; Apicella, Carmel; Southey, Melissa C.; Spurdle, Amanda; Häberle, Lothar; Beckmann, Matthias W.; Ekici, Arif B.; Dieffenbach, Aida Karina; Arndt, Volker; Stegmaier, Christa; McLean, Catriona; Baglietto, Laura; Chanock, Stephen J.; Lissowska, Jolanta; Sherman, Mark E.; Brüning, Thomas; Hamann, Ute; Ko, Yon-Dschun; Orr, Nick; Schoemaker, Minouk; Ashworth, Alan; Kosma, Veli-Matti; Kataja, Vesa; Hartikainen, Jaana M.; Mannermaa, Arto; Swerdlow, Anthony; Giles, Graham G.; Brenner, Hermann; Fasching, Peter A.; Chenevix-Trench, Georgia; Hopper, John; Benítez, Javier; Cox, Angela; Andrulis, Irene L.; Lambrechts, Diether; Gago-Dominguez, Manuela; Couch, Fergus; Czene, Kamila; Bojesen, Stig E.; Easton, Doug F.; Schmidt, Marjanka K.; Guénel, Pascal; Hall, Per; Pharoah, Paul D. P.; Garcia-Closas, Montserrat; Chang-Claude, Jenny

    2015-01-01

    A large genotyping project within the Breast Cancer Association Consortium (BCAC) recently identified 41 associations between single nucleotide polymorphisms (SNPs) and overall breast cancer (BC) risk. We investigated whether the effects of these 41 SNPs, as well as six SNPs associated with estrogen

  9. Investigation of gene-environment interactions between 47 newly identified breast cancer susceptibility loci and environmental risk factors

    DEFF Research Database (Denmark)

    Rudolph, Anja; Milne, Roger L; Truong, Thérèse

    2015-01-01

    and overall BC risk was stronger for women who had had four or more pregnancies (OR = 0.85, p = 2.0 × 10(-4) ), and absent in women who had had just one (OR = 0.96, p = 0.19, pint = 6.1 × 10(-4) ). SNP rs11242675 was inversely associated with overall BC risk in never/former smokers (OR = 0.93, p = 2.8 × 10......(-5) ), but no association was observed in current smokers (OR = 1.07, p = 0.14, pint = 3.4 × 10(-4) ). In conclusion, recently identified BC susceptibility loci are not strongly modified by established risk factors and the observed potential interactions require confirmation in independent studies....

  10. Gene-Environment Interactions in Severe Mental Illness

    Directory of Open Access Journals (Sweden)

    Rudolf eUher

    2014-05-01

    Full Text Available Severe mental illness is a broad category that includes schizophrenia, bipolar disorder and severe depression. Both genetic disposition and environmental exposures play important roles in the development of severe mental illness. Multiple lines of evidence suggest that the roles of genetic and environmental depend on each other. Gene-environment interactions may underlie the paradox of strong environmental factors for highly heritable disorders, the low estimates of shared environmental influences in twin studies of severe mental illness and the heritability gap between twin and molecular heritability estimates. Sons and daughters of parents with severe mental illness are more vulnerable to the effects of prenatal and postnatal environmental exposures, suggesting that the expression of genetic liability depends on environment. In the last decade, gene-environment interactions involving specific molecular variants in candidate genes have been identified. Replicated findings include an interaction between a polymorphism in the AKT1 gene and cannabis use in the development of psychosis and an interaction between the length polymorphism of the serotonin transporter gene and childhood maltreatment in the development of persistent depressive disorder. Bipolar disorder has been underinvestigated, with only a single study showing an interaction between a functional polymorphism in BDNF and stressful life events triggering bipolar depressive episodes. The first systematic search for gene-environment interactions has found that a polymorphism in CTNNA3 may sensitise the developing brain to the pathogenic effect of cytomegalovirus in utero, leading to schizophrenia in adulthood. Strategies for genome-wide investigations will likely include coordination between epidemiological and genetic research efforts, systematic assessment of multiple environmental factors in large samples, and prioritization of genetic variants.

  11. Identifying Gene-Environment Interactions in Schizophrenia

    DEFF Research Database (Denmark)

    van Os, Jim; Rutten, Bart P; Myin-Germeys, Inez

    2014-01-01

    Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual...... of G × E in schizophrenia. While such investigations are now well underway, new challenges emerge for G × E research from late-breaking evidence that genetic variation and environmental exposures are, to a significant degree, shared across a range of psychiatric disorders, with potential overlap...

  12. Gene-environment interaction and male reproductive function

    Science.gov (United States)

    Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L.; Rylander, Lars; Giwercman, Aleksander

    2010-01-01

    As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism, but the number of studies is still limited. This type of interaction studies may improve our understanding of normal physiology and help us to identify the risk factors to male reproductive malfunction. We also shortly discuss other aspects of gene-environment interaction specifically associated with the issue of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity in the offspring. PMID:20348940

  13. Robust Tests for Additive Gene-Environment Interaction in Case-Control Studies Using Gene-Environment Independence

    DEFF Research Database (Denmark)

    Liu, Gang; Lee, Seunggeun; Lee, Alice W

    2018-01-01

    test with case-control data. Our simulation studies suggest that the EB approach uses the gene-environment independence assumption in a data-adaptive way and provides power gain compared to the standard logistic regression analysis and better control of Type I error when compared to the analysis......There have been recent proposals advocating the use of additive gene-environment interaction instead of the widely used multiplicative scale, as a more relevant public health measure. Using gene-environment independence enhances the power for testing multiplicative interaction in case......-control studies. However, under departure from this assumption, substantial bias in the estimates and inflated Type I error in the corresponding tests can occur. This paper extends the empirical Bayes (EB) approach previously developed for multiplicative interaction that trades off between bias and efficiency...

  14. Animal model for schizophrenia that reflects gene-environment interactions.

    Science.gov (United States)

    Nagai, Taku; Ibi, Daisuke; Yamada, Kiyofumi

    2011-01-01

    Schizophrenia is a devastating psychiatric disorder that impairs mental and social functioning and affects approximately 1% of the population worldwide. Genetic susceptibility factors for schizophrenia have recently been reported, some of which are known to play a role in neurodevelopment; these include neuregulin-1, dysbindin, and disrupted-in-schizophrenia 1 (DISC1). Moreover, epidemiologic studies suggest that environmental insults, such as prenatal infection and perinatal complication, are involved in the development of schizophrenia. The possible interaction between environment and genetic susceptibility factors, especially during neurodevelopment, is proposed as a promising disease etiology of schizophrenia. Polyriboinosinic-polyribocytidilic acid (polyI : C) is a synthetic analogue of double-stranded RNA that leads to the pronounced but time-limited production of pro-inflammatory cytokines. Maternal immune activation by polyI : C exposure in rodents is known to precipitate a wide spectrum of behavioral, cognitive, and pharmacological abnormalities in adult offspring. Recently, we have reported that neonatal injection of polyI : C in mice results in schizophrenia-like behavioral alterations in adulthood. In this review, we show how gene-environment interactions during neurodevelopment result in phenotypic changes in adulthood by injecting polyI : C into transgenic mice that express a dominant-negative form of human DISC1 (DN-DISC1). Our findings suggest that polyI : C-treated DN-DISC1 mice are a well-validated animal model for schizophrenia that reflects gene-environment interactions.

  15. Gene-Environment Interactions in Genome-Wide Association Studies: Current Approaches and New Directions

    Science.gov (United States)

    Winham, Stacey J.; Biernacka, Joanna M.

    2013-01-01

    Background: Complex psychiatric traits have long been thought to be the result of a combination of genetic and environmental factors, and gene-environment interactions are thought to play a crucial role in behavioral phenotypes and the susceptibility and progression of psychiatric disorders. Candidate gene studies to investigate hypothesized…

  16. Childhood temperament: passive gene-environment correlation, gene-environment interaction, and the hidden importance of the family environment.

    Science.gov (United States)

    Lemery-Chalfant, Kathryn; Kao, Karen; Swann, Gregory; Goldsmith, H Hill

    2013-02-01

    Biological parents pass on genotypes to their children, as well as provide home environments that correlate with their genotypes; thus, the association between the home environment and children's temperament can be genetically (i.e., passive gene-environment correlation) or environmentally mediated. Furthermore, family environments may suppress or facilitate the heritability of children's temperament (i.e., gene-environment interaction). The sample comprised 807 twin pairs (mean age = 7.93 years) from the longitudinal Wisconsin Twin Project. Important passive gene-environment correlations emerged, such that home environments were less chaotic for children with high effortful control, and this association was genetically mediated. Children with high extraversion/surgency experienced more chaotic home environments, and this correlation was also genetically mediated. In addition, heritability of children's temperament was moderated by home environments, such that effortful control and extraversion/surgency were more heritable in chaotic homes, and negative affectivity was more heritable under crowded or unsafe home conditions. Modeling multiple types of gene-environment interplay uncovered the complex role of genetic factors and the hidden importance of the family environment for children's temperament and development more generally.

  17. Sleep Duration and Depressive Symptoms: A Gene-Environment Interaction

    Science.gov (United States)

    Watson, Nathaniel F.; Harden, Kathryn Paige; Buchwald, Dedra; Vitiello, Michael V.; Pack, Allan I.; Strachan, Eric; Goldberg, Jack

    2014-01-01

    Objective: We used quantitative genetic models to assess whether sleep duration modifies genetic and environmental influences on depressive symptoms. Method: Participants were 1,788 adult twins from 894 same-sex twin pairs (192 male and 412 female monozygotic [MZ] pairs, and 81 male and 209 female dizygotic [DZ] pairs] from the University of Washington Twin Registry. Participants self-reported habitual sleep duration and depressive symptoms. Data were analyzed using quantitative genetic interaction models, which allowed the magnitude of additive genetic, shared environmental, and non-shared environmental influences on depressive symptoms to vary with sleep duration. Results: Within MZ twin pairs, the twin who reported longer sleep duration reported fewer depressive symptoms (ec = -0.17, SE = 0.06, P sleep duration interaction effect on depressive symptoms (a'c = 0.23, SE = 0.08, P sleep duration and depressive symptoms. Among individuals with sleep duration within the normal range (7-8.9 h/night), the total heritability (h2) of depressive symptoms was approximately 27%. However, among individuals with sleep duration within the low (sleep duration extremes (5 h/night: h2 = 53%; 10 h/night: h2 = 49%). Conclusion: Genetic contributions to depressive symptoms increase at both short and long sleep durations. Citation: Watson NF; Harden KP; Buchwald D; Vitiello MV; Pack AI; Stachan E; Goldberg J. Sleep duration and depressive symptoms: a gene-environment interaction. SLEEP 2014;37(2):351-358. PMID:24497663

  18. Study of oral clefts: Indication of gene-environment interaction

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, S.J.; Beaty, T.H.; Panny, S. [Johns Hopkins Univ., Baltimore, MD (United States)] [and others

    1994-09-01

    In this study of infants with isolated birth defects, 69 cleft palate-only (CPO) cases, 114 cleft lip with or without palate (CL/P), and 284 controls with non-cleft birth defects (all born in Maryland during 1984-1992) were examined to test for associations among genetic markers and different oral clefts. Modest associations were found between transforming growth factor {alpha} (TGF{alpha}) marker and CPO, as well as that between D17S579 (Mfd188) and CL/P in this study. The association between TGF{alpha} marker and CPO reflects a statistical interaction between mother`s smoking and child`s TGF{alpha} genotype. A significantly higher risk of CPO was found among those reporting maternal smoking during pregnancy and carrying less common TGF{alpha} TaqI allele (odds ratio=7.02 with 95% confidence interval 1.8-27.6). This gene-environment interaction was also found among those who reported no family history of any type of birth defect (odds ratio=5.60 with 95% confidence interval 1.4-22.9). Similar associations were seen for CL/P, but these were not statistically significant.

  19. Music training and speech perception: a gene-environment interaction.

    Science.gov (United States)

    Schellenberg, E Glenn

    2015-03-01

    Claims of beneficial side effects of music training are made for many different abilities, including verbal and visuospatial abilities, executive functions, working memory, IQ, and speech perception in particular. Such claims assume that music training causes the associations even though children who take music lessons are likely to differ from other children in music aptitude, which is associated with many aspects of speech perception. Music training in childhood is also associated with cognitive, personality, and demographic variables, and it is well established that IQ and personality are determined largely by genetics. Recent evidence also indicates that the role of genetics in music aptitude and music achievement is much larger than previously thought. In short, music training is an ideal model for the study of gene-environment interactions but far less appropriate as a model for the study of plasticity. Children seek out environments, including those with music lessons, that are consistent with their predispositions; such environments exaggerate preexisting individual differences. © 2015 New York Academy of Sciences.

  20. Gene-Gene and Gene-Environment Interactions in the Etiology of Breast Cancer

    National Research Council Canada - National Science Library

    Adegoke, Olufemi

    2003-01-01

    The objective of this CDA is to evaluate the gene-gene and gene-environment interactions in the etiology of breast cancer in two ongoing case-control studies, the Shanghai Breast Cancer Study (SBCS...

  1. The Ethics of Translational Science: Imagining Public Benefit in Gene-Environment Interaction Research

    Directory of Open Access Journals (Sweden)

    Sara L. Ackerman

    2017-06-01

    Full Text Available Biomedical research is increasingly informed by expectations of “translation,” which call for the production of scientific knowledge that can be used to create services and products that improve health outcomes. In this paper, we ask how translation, in particular the idea of social responsibility, is understood and enacted in the post-genomic life sciences. Drawing on theories examining what constitutes “good science,” and interviews with 35 investigators who study the role of gene-environment interactions in the etiology of cancer, diabetes, and cardiovascular disease, we describe the dynamic and unsettled ethics of translational science through which the expected social value of scientific knowledge about complex disease causation is negotiated. To describe how this ethics is formed, we first discuss the politics of knowledge production in interdisciplinary research collectives. Researchers described a commitment to working across disciplines to examine a wide range of possible causes of disease, but they also pointed to persistent disciplinary and ontological divisions that rest on the dominance of molecular conceptions of disease risk. The privileging of molecular-level causation shapes and constrains the kinds of knowledge that can be created about gene-environment interactions. We then turn to scientists’ ideas about how this knowledge should be used, including personalized prevention strategies, targeted therapeutics, and public policy interventions. Consensus about the relative value of these anticipated translations was elusive, and many scientists agreed that gene-environment interaction research is part of a shift in biomedical research away from considering important social, economic, political and historical causes of disease and disease disparities. We conclude by urging more explicit engagement with questions about the ethics of translational science in the post-genomic life sciences. This would include a consideration

  2. Gene-Environment Interaction Research and Transgenic Mouse Models of Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    L. Chouliaras

    2010-01-01

    Full Text Available The etiology of the sporadic form of Alzheimer's disease (AD remains largely unknown. Recent evidence has suggested that gene-environment interactions (GxE may play a crucial role in its development and progression. Whereas various susceptibility loci have been identified, like the apolipoprotein E4 allele, these cannot fully explain the increasing prevalence of AD observed with aging. In addition to such genetic risk factors, various environmental factors have been proposed to alter the risk of developing AD as well as to affect the rate of cognitive decline in AD patients. Nevertheless, aside from the independent effects of genetic and environmental risk factors, their synergistic participation in increasing the risk of developing AD has been sparsely investigated, even though evidence points towards such a direction. Advances in the genetic manipulation of mice, modeling various aspects of the AD pathology, have provided an excellent tool to dissect the effects of genes, environment, and their interactions. In this paper we present several environmental factors implicated in the etiology of AD that have been tested in transgenic animal models of the disease. The focus lies on the concept of GxE and its importance in a multifactorial disease like AD. Additionally, possible mediating mechanisms and future challenges are discussed.

  3. Environmental and gene-environment interactions and risk of rheumatoid arthritis

    Science.gov (United States)

    Karlson, Elizabeth W.; Deane, Kevin

    2012-01-01

    Multiple environmental factors including hormones, dietary factors, infections and exposure to tobacco smoke as well as gene-environment interactions have been associated with increased risk for rheumatoid arthritis (RA). Importantly, the growing understanding of the prolonged period prior to the first onset of symptoms of RA suggests that these environmental and genetic factors are likely acting to drive the development of RA-related autoimmunity long before the appearance of the first joint symptoms and clinical findings that are characteristic of RA. Herein we will review these factors and interactions, especially those that have been investigated in a prospective fashion prior to the symptomatic onset of RA. We will also discuss how these factors may be explored in future study to further the understanding of the pathogenesis of RA, and ultimately perhaps develop preventive measures for this disease. PMID:22819092

  4. Modeling Gene-Environment Interactions With Quasi-Natural Experiments.

    Science.gov (United States)

    Schmitz, Lauren; Conley, Dalton

    2017-02-01

    This overview develops new empirical models that can effectively document Gene × Environment (G×E) interactions in observational data. Current G×E studies are often unable to support causal inference because they use endogenous measures of the environment or fail to adequately address the nonrandom distribution of genes across environments, confounding estimates. Comprehensive measures of genetic variation are incorporated into quasi-natural experimental designs to exploit exogenous environmental shocks or isolate variation in environmental exposure to avoid potential confounders. In addition, we offer insights from population genetics that improve upon extant approaches to address problems from population stratification. Together, these tools offer a powerful way forward for G×E research on the origin and development of social inequality across the life course. © 2015 Wiley Periodicals, Inc.

  5. Gene-environment interaction and male reproductive function

    DEFF Research Database (Denmark)

    Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L

    2010-01-01

    As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between...... that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism...... of reproduction, namely environmental and lifestyle factors as the cause of sperm DNA damage. It remains to be investigated to what extent such genetic changes, by natural conception or through the use of assisted reproductive techniques, are transmitted to the next generation, thereby causing increased morbidity...

  6. How Gene-Environment Interaction Affects Children's Anxious and Fearful Behavior. Science Briefs

    Science.gov (United States)

    National Scientific Council on the Developing Child, 2007

    2007-01-01

    "Science Briefs" summarize the findings and implications of a recent study in basic science or clinical research. This brief reports on the study "Evidence for a Gene-Environment Interaction in Predicting Behavioral Inhibition in Middle Childhood" (N. A. Fox, K E. Nichols, H. A. Henderson, K. Rubin, L. Schmidt, D. Hamer, M. Ernst, and D. S.…

  7. Gene environment interaction studies in depression and suicidal behavior: An update.

    Science.gov (United States)

    Mandelli, Laura; Serretti, Alessandro

    2013-12-01

    Increasing evidence supports the involvement of both heritable and environmental risk factors in major depression (MD) and suicidal behavior (SB). Studies investigating gene-environment interaction (G × E) may be useful for elucidating the role of biological mechanisms in the risk for mental disorders. In the present paper, we review the literature regarding the interaction between genes modulating brain functions and stressful life events in the etiology of MD and SB and discuss their potential added benefit compared to genetic studies only. Within the context of G × E investigation, thus far, only a few reliable results have been obtained, although some genes have consistently shown interactive effects with environmental risk in MD and, to a lesser extent, in SB. Further investigation is required to disentangle the direct and mediated effects that are common or specific to MD and SB. Since traditional G × E studies overall suffer from important methodological limitations, further effort is required to develop novel methodological strategies with an interdisciplinary approach. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Gene-environment interaction and behavioral disorders: a developmental perspective based on endophenotypes.

    Science.gov (United States)

    Battaglia, Marco; Marino, Cecilia; Maziade, Michel; Molteni, Massimo; D'Amato, Francesca

    2008-01-01

    It has been observed that 'No aspect of human behavioral genetics has caused more confusion and generated more obscurantism than the analysis and interpretation of various types of non-additivity and non-independence of gene and environmental action and interaction' (Eaves LJ et al 1977 Br J Math Stat Psychol 30:1-42). On the other hand, a bulk of newly published studies appear to speak in favour of common and frequent interplay--and possibly interaction--between identified genetic polymorphisms and specified environmental variables in shaping behavior and behavioral disorders. Considerable interest has arisen from the introduction of putative functional 'endophenotypes' which would represent a more proximate biological link to genes, as well as an obligatory intermediate of behavior. While explicit criteria to identify valid endophenotypes have been offered, a number of new 'alternative phenotypes' are now being proposed as possible 'endophenotypes' for behavioral and psychiatric genetics research, sometimes with less than optimal stringency. Nonetheless, we suggest that some endophenotypes can be helpful in investigating several instances of gene-environment interactions and be employed as additional tools to reduce the risk for spurious results in this controversial area.

  9. A novel approach to simulate gene-environment interactions in complex diseases

    Directory of Open Access Journals (Sweden)

    Nicodemi Mario

    2010-01-01

    Full Text Available Abstract Background Complex diseases are multifactorial traits caused by both genetic and environmental factors. They represent the major part of human diseases and include those with largest prevalence and mortality (cancer, heart disease, obesity, etc.. Despite a large amount of information that has been collected about both genetic and environmental risk factors, there are few examples of studies on their interactions in epidemiological literature. One reason can be the incomplete knowledge of the power of statistical methods designed to search for risk factors and their interactions in these data sets. An improvement in this direction would lead to a better understanding and description of gene-environment interactions. To this aim, a possible strategy is to challenge the different statistical methods against data sets where the underlying phenomenon is completely known and fully controllable, for example simulated ones. Results We present a mathematical approach that models gene-environment interactions. By this method it is possible to generate simulated populations having gene-environment interactions of any form, involving any number of genetic and environmental factors and also allowing non-linear interactions as epistasis. In particular, we implemented a simple version of this model in a Gene-Environment iNteraction Simulator (GENS, a tool designed to simulate case-control data sets where a one gene-one environment interaction influences the disease risk. The main aim has been to allow the input of population characteristics by using standard epidemiological measures and to implement constraints to make the simulator behaviour biologically meaningful. Conclusions By the multi-logistic model implemented in GENS it is possible to simulate case-control samples of complex disease where gene-environment interactions influence the disease risk. The user has full control of the main characteristics of the simulated population and a Monte

  10. A methodology to establish a database to study gene environment interactions for childhood asthma

    Directory of Open Access Journals (Sweden)

    McCormick Jonathan

    2010-12-01

    Full Text Available Abstract Background Gene-environment interactions are likely to explain some of the heterogeneity in childhood asthma. Here, we describe the methodology and experiences in establishing a database for childhood asthma designed to study gene-environment interactions (PAGES - Paediatric Asthma Gene Environment Study. Methods Children with asthma and under the care of a respiratory paediatrician are being recruited from 15 hospitals between 2008 and 2011. An asthma questionnaire is completed and returned by post. At a routine clinic visit saliva is collected for DNA extraction. Detailed phenotyping in a proportion of children includes spirometry, bronchodilator response (BDR, skin prick reactivity, exhaled nitric oxide and salivary cotinine. Dietary and quality of life questionnaires are completed. Data are entered onto a purpose-built database. Results To date 1045 children have been invited to participate and data collected in 501 (48%. The mean age (SD of participants is 8.6 (3.9 years, 57% male. DNA has been collected in 436 children. Spirometry has been obtained in 172 children, mean % predicted (SD FEV1 97% (15 and median (IQR BDR is 5% (2, 9. There were differences in age, socioeconomic status, severity and %FEV1 between the different centres (p≤0.024. Reasons for non-participation included parents not having time to take part, children not attending clinics and, in a small proportion, refusal to take part. Conclusions It is feasible to establish a national database to study gene-environment interactions within an asthmatic paediatric population; there are barriers to participation and some different characteristics in individuals recruited from different centres. Recruitment to our study continues and is anticipated to extend current understanding of asthma heterogeneity.

  11. The genetics of music accomplishment: evidence for gene-environment correlation and interaction.

    Science.gov (United States)

    Hambrick, David Z; Tucker-Drob, Elliot M

    2015-02-01

    Theories of skilled performance that emphasize training history, such as K. Anders Ericsson and colleagues' deliberate-practice theory, have received a great deal of recent attention in both the scientific literature and the popular press. Twin studies, however, have demonstrated evidence for moderate-to-strong genetic influences on skilled performance. Focusing on musical accomplishment in a sample of over 800 pairs of twins, we found evidence for gene-environment correlation, in the form of a genetic effect on music practice. However, only about one quarter of the genetic effect on music accomplishment was explained by this genetic effect on music practice, suggesting that genetically influenced factors other than practice contribute to individual differences in music accomplishment. We also found evidence for gene-environment interaction, such that genetic effects on music accomplishment were most pronounced among those engaging in music practice, suggesting that genetic potentials for skilled performance are most fully expressed and fostered by practice.

  12. Environmental factors as modulators of neurodegeneration: insights from gene-environment interactions in Huntington's disease.

    Science.gov (United States)

    Mo, Christina; Hannan, Anthony J; Renoir, Thibault

    2015-05-01

    Unlike many other neurodegenerative diseases with established gene-environment interactions, Huntington's disease (HD) is viewed as a disorder governed by genetics. The cause of the disease is a highly penetrant tandem repeat expansion encoding an extended polyglutamine tract in the huntingtin protein. In the year 2000, a pioneering study showed that the disease could be delayed in transgenic mice by enriched housing conditions. This review describes subsequent human and preclinical studies identifying environmental modulation of motor, cognitive, affective and other symptoms found in HD. Alongside the behavioral observations we also discuss potential mechanisms and the relevance to other neurodegenerative disorders, including Alzheimer's and Parkinson's disease. In mouse models of HD, increased sensorimotor and cognitive stimulation can delay or ameliorate various endophenotypes. Potential mechanisms include increased trophic support, synaptic plasticity, adult neurogenesis, and other forms of experience-dependent cellular plasticity. Subsequent clinical investigations support a role for lifetime activity levels in modulating the onset and progression of HD. Stress can accelerate memory and olfactory deficits and exacerbate cellular dysfunctions in HD mice. In the absence of effective treatments to slow the course of HD, environmental interventions offer feasible approaches to delay the disease, however further preclinical and human studies are needed in order to generate clinical recommendations. Environmental interventions could be combined with future pharmacological therapies and stimulate the identification of enviromimetics, drugs which mimic or enhance the beneficial effects of cognitive stimulation and physical activity. Copyright © 2015. Published by Elsevier Ltd.

  13. Childhood problem behavior and parental divorce: evidence for gene-environment interaction.

    Science.gov (United States)

    Robbers, Sylvana; van Oort, Floor; Huizink, Anja; Verhulst, Frank; van Beijsterveldt, Catharina; Boomsma, Dorret; Bartels, Meike

    2012-10-01

    The importance of genetic and environmental influences on children's behavioral and emotional problems may vary as a function of environmental exposure. We previously reported that 12-year-olds with divorced parents showed more internalizing and externalizing problems than children with married parents, and that externalizing problems in girls precede and predict later parental divorce. The aim of the current study was to investigate as to whether genetic and environmental influences on internalizing and externalizing problems were different for children from divorced versus non-divorced families. Maternal ratings on internalizing and externalizing problems were collected with the Child Behavior Checklist in 4,592 twin pairs at ages 3 and 12 years, of whom 367 pairs had experienced a parental divorce between these ages. Variance in internalizing and externalizing problems at ages 3 and 12 was analyzed with biometric models in which additive genetic and environmental effects were allowed to depend on parental divorce and sex. A difference in the contribution of genetic and environmental influences between divorced and non-divorced groups would constitute evidence for gene-environment interaction. For both pre- and post-divorce internalizing and externalizing problems, the total variances were larger for children from divorced families, which was mainly due to higher environmental variances. As a consequence, heritabilities were lower for children from divorced families, and the relative contributions of environmental influences were higher. Environmental influences become more important in explaining variation in children's problem behaviors in the context of parental divorce.

  14. Cognitive endophenotypes, gene-environment interactions and experience-dependent plasticity in animal models of schizophrenia.

    Science.gov (United States)

    Burrows, Emma L; Hannan, Anthony J

    2016-04-01

    Schizophrenia is a devastating brain disorder caused by a complex and heterogeneous combination of genetic and environmental factors. In order to develop effective new strategies to prevent and treat schizophrenia, valid animal models are required which accurately model the disorder, and ideally provide construct, face and predictive validity. The cognitive deficits in schizophrenia represent some of the most debilitating symptoms and are also currently the most poorly treated. Therefore it is crucial that animal models are able to capture the cognitive dysfunction that characterizes schizophrenia, as well as the negative and psychotic symptoms. The genomes of mice have, prior to the recent gene-editing revolution, proven the most easily manipulable of mammalian laboratory species, and hence most genetic targeting has been performed using mouse models. Importantly, when key environmental factors of relevance to schizophrenia are experimentally manipulated, dramatic changes in the phenotypes of these animal models are often observed. We will review recent studies in rodent models which provide insight into gene-environment interactions in schizophrenia. We will focus specifically on environmental factors which modulate levels of experience-dependent plasticity, including environmental enrichment, cognitive stimulation, physical activity and stress. The insights provided by this research will not only help refine the establishment of optimally valid animal models which facilitate development of novel therapeutics, but will also provide insight into the pathogenesis of schizophrenia, thus identifying molecular and cellular targets for future preclinical and clinical investigations. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Shame and Guilt-Proneness in Adolescents: Gene-Environment Interactions.

    Science.gov (United States)

    Szentágotai-Tătar, Aurora; Chiș, Adina; Vulturar, Romana; Dobrean, Anca; Cândea, Diana Mirela; Miu, Andrei C

    2015-01-01

    Rooted in people's preoccupation with how they are perceived and evaluated, shame and guilt are self-conscious emotions that play adaptive roles in social behavior, but can also contribute to psychopathology when dysregulated. Shame and guilt-proneness develop during childhood and adolescence, and are influenced by genetic and environmental factors that are little known to date. This study investigated the effects of early traumatic events and functional polymorphisms in the brain-derived neurotrophic factor (BDNF) gene and the serotonin transporter gene promoter (5-HTTLPR) on shame and guilt in adolescents. A sample of N = 271 healthy adolescents between 14 and 17 years of age filled in measures of early traumatic events and proneness to shame and guilt, and were genotyped for the BDNF Val66Met and 5-HTTLPR polymorphisms. Results of moderator analyses indicated that trauma intensity was positively associated with guilt-proneness only in carriers of the low-expressing Met allele of BDNF Val66Met. This is the first study that identifies a gene-environment interaction that significantly contributes to guilt proneness in adolescents, with potential implications for developmental psychopathology.

  16. Gene-environment interaction involving recently identified colorectal cancer susceptibility loci

    Science.gov (United States)

    Kantor, Elizabeth D.; Hutter, Carolyn M.; Minnier, Jessica; Berndt, Sonja I.; Brenner, Hermann; Caan, Bette J.; Campbell, Peter T.; Carlson, Christopher S.; Casey, Graham; Chan, Andrew T.; Chang-Claude, Jenny; Chanock, Stephen J.; Cotterchio, Michelle; Du, Mengmeng; Duggan, David; Fuchs, Charles S.; Giovannucci, Edward L.; Gong, Jian; Harrison, Tabitha A.; Hayes, Richard B.; Henderson, Brian E.; Hoffmeister, Michael; Hopper, John L.; Jenkins, Mark A.; Jiao, Shuo; Kolonel, Laurence N.; Le Marchand, Loic; Lemire, Mathieu; Ma, Jing; Newcomb, Polly A.; Ochs-Balcom, Heather M.; Pflugeisen, Bethann M.; Potter, John D.; Rudolph, Anja; Schoen, Robert E.; Seminara, Daniela; Slattery, Martha L.; Stelling, Deanna L.; Thomas, Fridtjof; Thornquist, Mark; Ulrich, Cornelia M.; Warnick, Greg S.; Zanke, Brent W.; Peters, Ulrike; Hsu, Li; White, Emily

    2014-01-01

    BACKGROUND Genome-wide association studies have identified several single nucleotide polymorphisms (SNPs) that are associated with risk of colorectal cancer (CRC). Prior research has evaluated the presence of gene-environment interaction involving the first 10 identified susceptibility loci, but little work has been conducted on interaction involving SNPs at recently identified susceptibility loci, including: rs10911251, rs6691170, rs6687758, rs11903757, rs10936599, rs647161, rs1321311, rs719725, rs1665650, rs3824999, rs7136702, rs11169552, rs59336, rs3217810, rs4925386, and rs2423279. METHODS Data on 9160 cases and 9280 controls from the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colon Cancer Family Registry (CCFR) were used to evaluate the presence of interaction involving the above-listed SNPs and sex, body mass index (BMI), alcohol consumption, smoking, aspirin use, post-menopausal hormone (PMH) use, as well as intake of dietary calcium, dietary fiber, dietary folate, red meat, processed meat, fruit, and vegetables. Interaction was evaluated using a fixed-effects meta-analysis of an efficient Empirical Bayes estimator, and permutation was used to account for multiple comparisons. RESULTS None of the permutation-adjusted p-values reached statistical significance. CONCLUSIONS The associations between recently identified genetic susceptibility loci and CRC are not strongly modified by sex, BMI, alcohol, smoking, aspirin, PMH use, and various dietary factors. IMPACT Results suggest no evidence of strong gene-environment interactions involving the recently identified 16 susceptibility loci for CRC taken one at a time. PMID:24994789

  17. The Interacting Effect of the BDNF Val66Met Polymorphism and Stressful Life Events on Adolescent Depression Is Not an Artifact of Gene-Environment Correlation: Evidence from a Longitudinal Twin Study

    Science.gov (United States)

    Chen, Jie; Li, Xinying; McGue, Matt

    2013-01-01

    Background: Confounding introduced by gene-environment correlation (rGE) may prevent one from observing a true gene-environment interaction (G × E) effect on psychopathology. The present study investigated the interacting effect of the BDNF Val66Met polymorphism and stressful life events (SLEs) on adolescent depression while controlling for the…

  18. Microsatellite polymorphisms associated with human behavioural and psychological phenotypes including a gene-environment interaction.

    Science.gov (United States)

    Bagshaw, Andrew T M; Horwood, L John; Fergusson, David M; Gemmell, Neil J; Kennedy, Martin A

    2017-02-03

    deserves further investigation. Our results suggest that it participates in a gene-environment interaction with MDSP and antisocial behaviour. However, previous evidence that mothers who smoke during pregnancy carry genes for antisocial behaviour suggests that epistasis may influence the interaction.

  19. Gene Environment Interactions and Predictors of Colorectal Cancer in Family-Based, Multi-Ethnic Groups.

    Science.gov (United States)

    Shiao, S Pamela K; Grayson, James; Yu, Chong Ho; Wasek, Brandi; Bottiglieri, Teodoro

    2018-02-16

    For the personalization of polygenic/omics-based health care, the purpose of this study was to examine the gene-environment interactions and predictors of colorectal cancer (CRC) by including five key genes in the one-carbon metabolism pathways. In this proof-of-concept study, we included a total of 54 families and 108 participants, 54 CRC cases and 54 matched family friends representing four major racial ethnic groups in southern California (White, Asian, Hispanics, and Black). We used three phases of data analytics, including exploratory, family-based analyses adjusting for the dependence within the family for sharing genetic heritage, the ensemble method, and generalized regression models for predictive modeling with a machine learning validation procedure to validate the results for enhanced prediction and reproducibility. The results revealed that despite the family members sharing genetic heritage, the CRC group had greater combined gene polymorphism rates than the family controls ( p relation to gene-environment interactions in the prevention of CRC.

  20. Evidence for gene-environment interaction in a genome wide study of nonsyndromic cleft palate

    DEFF Research Database (Denmark)

    Beaty, Terri H; Ruczinski, Ingo; Murray, Jeffrey C

    2011-01-01

    Nonsyndromic cleft palate (CP) is a common birth defect with a complex and heterogeneous etiology involving both genetic and environmental risk factors. We conducted a genome-wide association study (GWAS) using 550 case-parent trios, ascertained through a CP case collected in an international...... consortium. Family-based association tests of single nucleotide polymorphisms (SNP) and three common maternal exposures (maternal smoking, alcohol consumption, and multivitamin supplementation) were used in a combined 2 df test for gene (G) and gene-environment (G × E) interaction simultaneously, plus...... multiple SNPs associated with higher risk of CP in the presence of maternal smoking. Additional evidence of reduced risk due to G × E interaction in the presence of multivitamin supplementation was observed for SNPs in BAALC on chr. 8. These results emphasize the need to consider G × E interaction when...

  1. Leveraging gene-environment interactions and endotypes for asthma gene discovery

    DEFF Research Database (Denmark)

    Bønnelykke, Klaus; Ober, Carole

    2016-01-01

    , such as childhood asthma with severe exacerbations, and on relevant exposures that are involved in gene-environment interactions (GEIs), such as rhinovirus infections, will improve detection of asthma genes and our understanding of the underlying mechanisms. We will discuss the challenges of considering GEIs......Asthma is a heterogeneous clinical syndrome that includes subtypes of disease with different underlying causes and disease mechanisms. Asthma is caused by a complex interaction between genes and environmental exposures; early-life exposures in particular play an important role. Asthma is also...... heritable, and a number of susceptibility variants have been discovered in genome-wide association studies, although the known risk alleles explain only a small proportion of the heritability. In this review, we present evidence supporting the hypothesis that focusing on more specific asthma phenotypes...

  2. Genetic risk for schizophrenia, obstetric complications, and adolescent school outcome: evidence for gene-environment interaction.

    Science.gov (United States)

    Forsyth, Jennifer K; Ellman, Lauren M; Tanskanen, Antti; Mustonen, Ulla; Huttunen, Matti O; Suvisaari, Jaana; Cannon, Tyrone D

    2013-09-01

    Low birth weight (LBW) and hypoxia are among the environmental factors most reliably associated with schizophrenia; however, the nature of this relationship is unclear and both gene-environment interaction and gene-environment covariation models have been proposed as explanations. High-risk (HR) designs that explore whether obstetric complications differentially predict outcomes in offspring at low risk (LR) vs HR for schizophrenia, while accounting for differences in rates of maternal risk factors, may shed light on this question. This study used prospectively obtained data to examine relationships between LBW and hypoxia on school outcome at age 15-16 years in a Finnish sample of 1070 offspring at LR for schizophrenia and 373 offspring at HR for schizophrenia, based on parental psychiatric history. Controlling for offspring sex, maternal smoking, social support, parity, age, and number of prenatal care visits, HR offspring performed worse than LR offspring across academic, nonacademic, and physical education domains. LBW predicted poorer academic and physical education performance in HR offspring, but not in LR offspring, and this association was similar for offspring of fathers vs mothers with schizophrenia. Hypoxia predicted poorer physical education score across risk groups. Rates of LBW and hypoxia were similar for LR and HR offspring and for offspring of fathers vs mothers with schizophrenia. Results support the hypothesis that genetic susceptibility to schizophrenia confers augmented vulnerability of the developing brain to the effects of obstetric complications, possibly via epigenetic mechanisms.

  3. Evaluation of two methods for assessing gene-environment interactions using data from the Danish case-control study of facial clefts

    DEFF Research Database (Denmark)

    Etheredge, Analee J; Christensen, Kaare; Del Junco, Deborah

    2005-01-01

    BACKGROUND: Epidemiological investigations have begun to consider gene-environment (GE) interactions as potential risk factors for many diseases, including several different birth defects. However, traditional methodological approaches for the analysis of case-control data tend to have low power ...

  4. Behavior of QQ-plots and genomic control in studies of gene-environment interaction.

    Directory of Open Access Journals (Sweden)

    Arend Voorman

    2011-05-01

    Full Text Available Genome-wide association studies of gene-environment interaction (GxE GWAS are becoming popular. As with main effects GWAS, quantile-quantile plots (QQ-plots and Genomic Control are being used to assess and correct for population substructure. However, in G x E work these approaches can be seriously misleading, as we illustrate; QQ-plots may give strong indications of substructure when absolutely none is present. Using simulation and theory, we show how and why spurious QQ-plot inflation occurs in G x E GWAS, and how this differs from main-effects analyses. We also explain how simple adjustments to standard regression-based methods used in G x E GWAS can alleviate this problem.

  5. Animal models of gene-environment interaction in schizophrenia: A dimensional perspective.

    Science.gov (United States)

    Ayhan, Yavuz; McFarland, Ross; Pletnikov, Mikhail V

    2016-01-01

    Schizophrenia has long been considered as a disorder with multifactorial origins. Recent discoveries have advanced our understanding of the genetic architecture of the disease. However, even with the increase of identified risk variants, heritability estimates suggest an important contribution of non-genetic factors. Various environmental risk factors have been proposed to play a role in the etiopathogenesis of schizophrenia. These include season of birth, maternal infections, obstetric complications, adverse events at early childhood, and drug abuse. Despite the progress in identification of genetic and environmental risk factors, we still have a limited understanding of the mechanisms whereby gene-environment interactions (G × E) operate in schizophrenia and psychoses at large. In this review we provide a critical analysis of current animal models of G × E relevant to psychotic disorders and propose that dimensional perspective will advance our understanding of the complex mechanisms of these disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Animal models of gene-environment interaction in schizophrenia: a dimensional perspective

    Science.gov (United States)

    Ayhan, Yavuz; McFarland, Ross; Pletnikov, Mikhail V.

    2015-01-01

    Schizophrenia has long been considered as a disorder with multifactorial origins. Recent discoveries have advanced our understanding of the genetic architecture of the disease. However, even with the increase of identified risk variants, heritability estimates suggest an important contribution of non-genetic factors. Various environmental risk factors have been proposed to play a role in the etiopathogenesis of schizophrenia. These include season of birth, maternal infections, obstetric complications, adverse events at early childhood, and drug abuse. Despite the progress in identification of genetic and environmental risk factors, we still have a limited understanding of the mechanisms whereby gene-environment interactions (GxE) operate in schizophrenia and psychoses at large. In this review we provide a critical analysis of current animal models of GxE relevant to psychotic disorders and propose that dimensional perspective will advance our understanding of the complex mechanisms of these disorders. PMID:26510407

  7. A Fast Multiple-Kernel Method With Applications to Detect Gene-Environment Interaction.

    Science.gov (United States)

    Marceau, Rachel; Lu, Wenbin; Holloway, Shannon; Sale, Michèle M; Worrall, Bradford B; Williams, Stephen R; Hsu, Fang-Chi; Tzeng, Jung-Ying

    2015-09-01

    Kernel machine (KM) models are a powerful tool for exploring associations between sets of genetic variants and complex traits. Although most KM methods use a single kernel function to assess the marginal effect of a variable set, KM analyses involving multiple kernels have become increasingly popular. Multikernel analysis allows researchers to study more complex problems, such as assessing gene-gene or gene-environment interactions, incorporating variance-component based methods for population substructure into rare-variant association testing, and assessing the conditional effects of a variable set adjusting for other variable sets. The KM framework is robust, powerful, and provides efficient dimension reduction for multifactor analyses, but requires the estimation of high dimensional nuisance parameters. Traditional estimation techniques, including regularization and the "expectation-maximization (EM)" algorithm, have a large computational cost and are not scalable to large sample sizes needed for rare variant analysis. Therefore, under the context of gene-environment interaction, we propose a computationally efficient and statistically rigorous "fastKM" algorithm for multikernel analysis that is based on a low-rank approximation to the nuisance effect kernel matrices. Our algorithm is applicable to various trait types (e.g., continuous, binary, and survival traits) and can be implemented using any existing single-kernel analysis software. Through extensive simulation studies, we show that our algorithm has similar performance to an EM-based KM approach for quantitative traits while running much faster. We also apply our method to the Vitamin Intervention for Stroke Prevention (VISP) clinical trial, examining gene-by-vitamin effects on recurrent stroke risk and gene-by-age effects on change in homocysteine level. © 2015 WILEY PERIODICALS, INC.

  8. A combination test for detection of gene-environment interaction in cohort studies.

    Science.gov (United States)

    Coombes, Brandon; Basu, Saonli; McGue, Matt

    2017-07-01

    Identifying gene-environment (G-E) interactions can contribute to a better understanding of disease etiology, which may help researchers develop disease prevention strategies and interventions. One big criticism of studying G-E interaction is the lack of power due to sample size. Studies often restrict the interaction search to the top few hundred hits from a genome-wide association study or focus on potential candidate genes. In this paper, we test interactions between a candidate gene and an environmental factor to improve power by analyzing multiple variants within a gene. We extend recently developed score statistic based genetic association testing approaches to the G-E interaction testing problem. We also propose tests for interaction using gene-based summary measures that pool variants together. Although it has recently been shown that these summary measures can be biased and may lead to inflated type I error, we show that under several realistic scenarios, we can still provide valid tests of interaction. These tests use significantly less degrees of freedom and thus can have much higher power to detect interaction. Additionally, we demonstrate that the iSeq-aSum-min test, which combines a gene-based summary measure test, iSeq-aSum-G, and an interaction-based summary measure test, iSeq-aSum-I, provides a powerful alternative to test G-E interaction. We demonstrate the performance of these approaches using simulation studies and illustrate their performance to study interaction between the SNPs in several candidate genes and family climate environment on alcohol consumption using the Minnesota Center for Twin and Family Research dataset. © 2017 WILEY PERIODICALS, INC.

  9. Ranking and characterization of established BMI and lipid associated loci as candidates for gene-environment interactions

    DEFF Research Database (Denmark)

    Shungin, Dmitry; Deng, Wei Q; Varga, Tibor V

    2017-01-01

    Phenotypic variance heterogeneity across genotypes at a single nucleotide polymorphism (SNP) may reflect underlying gene-environment (G×E) or gene-gene interactions. We modeled variance heterogeneity for blood lipids and BMI in up to 44,211 participants and investigated relationships between...... variance effects (Pv), G×E interaction effects (with smoking and physical activity), and marginal genetic effects (Pm). Correlations between Pv and Pm were stronger for SNPs with established marginal effects (Spearman's ρ = 0.401 for triglycerides, and ρ = 0.236 for BMI) compared to all SNPs. When Pv...... and Pm were compared for all pruned SNPs, only BMI was statistically significant (Spearman's ρ = 0.010). Overall, SNPs with established marginal effects were overrepresented in the nominally significant part of the Pv distribution (Pbinomial BMI had...

  10. Comparison of weighting approaches for genetic risk scores in gene-environment interaction studies.

    Science.gov (United States)

    Hüls, Anke; Krämer, Ursula; Carlsten, Christopher; Schikowski, Tamara; Ickstadt, Katja; Schwender, Holger

    2017-12-16

    Weighted genetic risk scores (GRS), defined as weighted sums of risk alleles of single nucleotide polymorphisms (SNPs), are statistically powerful for detection gene-environment (GxE) interactions. To assign weights, the gold standard is to use external weights from an independent study. However, appropriate external weights are not always available. In such situations and in the presence of predominant marginal genetic effects, we have shown in a previous study that GRS with internal weights from marginal genetic effects ("GRS-marginal-internal") are a powerful and reliable alternative to single SNP approaches or the use of unweighted GRS. However, this approach might not be appropriate for detecting predominant interactions, i.e. interactions showing an effect stronger than the marginal genetic effect. In this paper, we present a weighting approach for such predominant interactions ("GRS-interaction-training") in which parts of the data are used to estimate the weights from the interaction terms and the remaining data are used to determine the GRS. We conducted a simulation study for the detection of GxE interactions in which we evaluated power, type I error and sign-misspecification. We compared this new weighting approach to the GRS-marginal-internal approach and to GRS with external weights. Our simulation study showed that in the absence of external weights and with predominant interaction effects, the highest power was reached with the GRS-interaction-training approach. If marginal genetic effects were predominant, the GRS-marginal-internal approach was more appropriate. Furthermore, the power to detect interactions reached by the GRS-interaction-training approach was only slightly lower than the power achieved by GRS with external weights. The power of the GRS-interaction-training approach was confirmed in a real data application to the Traffic, Asthma and Genetics (TAG) Study (N = 4465 observations). When appropriate external weights are unavailable, we

  11. Identification of New Genetic Susceptibility Loci for Breast Cancer Through Consideration of Gene-Environment Interactions

    Science.gov (United States)

    Schoeps, Anja; Rudolph, Anja; Seibold, Petra; Dunning, Alison M.; Milne, Roger L.; Bojesen, Stig E.; Swerdlow, Anthony; Andrulis, Irene; Brenner, Hermann; Behrens, Sabine; Orr, Nicholas; Jones, Michael; Ashworth, Alan; Li, Jingmei; Cramp, Helen; Connley, Dan; Czene, Kamila; Darabi, Hatef; Chanock, Stephen J.; Lissowska, Jolanta; Figueroa, Jonine D.; Knight, Julia; Glendon, Gord; Mulligan, Anna M.; Dumont, Martine; Severi, Gianluca; Baglietto, Laura; Olson, Janet; Vachon, Celine; Purrington, Kristen; Moisse, Matthieu; Neven, Patrick; Wildiers, Hans; Spurdle, Amanda; Kosma, Veli-Matti; Kataja, Vesa; Hartikainen, Jaana M.; Hamann, Ute; Ko, Yon-Dschun; Dieffenbach, Aida K.; Arndt, Volker; Stegmaier, Christa; Malats, Núria; Arias Perez, JoséI.; Benítez, Javier; Flyger, Henrik; Nordestgaard, Børge G.; Truong, Théresè; Cordina-Duverger, Emilie; Menegaux, Florence; Silva, Isabel dos Santos; Fletcher, Olivia; Johnson, Nichola; Häberle, Lothar; Beckmann, Matthias W.; Ekici, Arif B.; Braaf, Linde; Atsma, Femke; van den Broek, Alexandra J.; Makalic, Enes; Schmidt, Daniel F.; Southey, Melissa C.; Cox, Angela; Simard, Jacques; Giles, Graham G.; Lambrechts, Diether; Mannermaa, Arto; Brauch, Hiltrud; Guénel, Pascal; Peto, Julian; Fasching, Peter A.; Hopper, John; Flesch-Janys, Dieter; Couch, Fergus; Chenevix-Trench, Georgia; Pharoah, Paul D. P.; Garcia-Closas, Montserrat; Schmidt, Marjanka K.; Hall, Per; Easton, Douglas F.; Chang-Claude, Jenny

    2014-01-01

    Genes that alter disease risk only in combination with certain environmental exposures may not be detected in genetic association analysis. By using methods accounting for gene-environment (G × E) interaction, we aimed to identify novel genetic loci associated with breast cancer risk. Up to 34,475 cases and 34,786 controls of European ancestry from up to 23 studies in the Breast Cancer Association Consortium were included. Overall, 71,527 single nucleotide polymorphisms (SNPs), enriched for association with breast cancer, were tested for interaction with 10 environmental risk factors using three recently proposed hybrid methods and a joint test of association and interaction. Analyses were adjusted for age, study, population stratification, and confounding factors as applicable. Three SNPs in two independent loci showed statistically significant association: SNPs rs10483028 and rs2242714 in perfect linkage disequilibrium on chromosome 21 and rs12197388 in ARID1B on chromosome 6. While rs12197388 was identified using the joint test with parity and with age at menarche (P-values = 3 × 10−07), the variants on chromosome 21 q22.12, which showed interaction with adult body mass index (BMI) in 8,891 postmenopausal women, were identified by all methods applied. SNP rs10483028 was associated with breast cancer in women with a BMI below 25 kg/m2 (OR = 1.26, 95% CI 1.15–1.38) but not in women with a BMI of 30 kg/m2 or higher (OR = 0.89, 95% CI 0.72–1.11, P for interaction = 3.2 × 10−05). Our findings confirm comparable power of the recent methods for detecting G × E interaction and the utility of using G × E interaction analyses to identify new susceptibility loci. PMID:24248812

  12. An Efficient Test for Gene-Environment Interaction in Generalized Linear Mixed Models with Family Data.

    Science.gov (United States)

    Mazo Lopera, Mauricio A; Coombes, Brandon J; de Andrade, Mariza

    2017-09-27

    Gene-environment (GE) interaction has important implications in the etiology of complex diseases that are caused by a combination of genetic factors and environment variables. Several authors have developed GE analysis in the context of independent subjects or longitudinal data using a gene-set. In this paper, we propose to analyze GE interaction for discrete and continuous phenotypes in family studies by incorporating the relatedness among the relatives for each family into a generalized linear mixed model (GLMM) and by using a gene-based variance component test. In addition, we deal with collinearity problems arising from linkage disequilibrium among single nucleotide polymorphisms (SNPs) by considering their coefficients as random effects under the null model estimation. We show that the best linear unbiased predictor (BLUP) of such random effects in the GLMM is equivalent to the ridge regression estimator. This equivalence provides a simple method to estimate the ridge penalty parameter in comparison to other computationally-demanding estimation approaches based on cross-validation schemes. We evaluated the proposed test using simulation studies and applied it to real data from the Baependi Heart Study consisting of 76 families. Using our approach, we identified an interaction between BMI and the Peroxisome Proliferator Activated Receptor Gamma ( PPARG ) gene associated with diabetes.

  13. A Nonlinear Model for Gene-Based Gene-Environment Interaction

    Directory of Open Access Journals (Sweden)

    Jian Sa

    2016-06-01

    Full Text Available A vast amount of literature has confirmed the role of gene-environment (G×E interaction in the etiology of complex human diseases. Traditional methods are predominantly focused on the analysis of interaction between a single nucleotide polymorphism (SNP and an environmental variable. Given that genes are the functional units, it is crucial to understand how gene effects (rather than single SNP effects are influenced by an environmental variable to affect disease risk. Motivated by the increasing awareness of the power of gene-based association analysis over single variant based approach, in this work, we proposed a sparse principle component regression (sPCR model to understand the gene-based G×E interaction effect on complex disease. We first extracted the sparse principal components for SNPs in a gene, then the effect of each principal component was modeled by a varying-coefficient (VC model. The model can jointly model variants in a gene in which their effects are nonlinearly influenced by an environmental variable. In addition, the varying-coefficient sPCR (VC-sPCR model has nice interpretation property since the sparsity on the principal component loadings can tell the relative importance of the corresponding SNPs in each component. We applied our method to a human birth weight dataset in Thai population. We analyzed 12,005 genes across 22 chromosomes and found one significant interaction effect using the Bonferroni correction method and one suggestive interaction. The model performance was further evaluated through simulation studies. Our model provides a system approach to evaluate gene-based G×E interaction.

  14. Molecular Aspects of Dopaminergic Neurodegeneration: Gene-Environment Interaction in Parkin Dysfunction

    Directory of Open Access Journals (Sweden)

    Syed Z. Imam

    2011-12-01

    Full Text Available Parkinson’s disease (PD is a common neurodegenerative movement disorder that is characterized pathologically by a progressive loss of midbrain dopaminergic neurons and by protein inclusions, designated Lewy bodies and Lewy neurites. PD is one of the most common neurodegenerative diseases, affecting almost 1% of the population over 60 years old. Although the symptoms and neuropathology of PD have been well characterized, the underlying mechanisms and causes of the disease are still not clear. Genetic mutations can provide important clues to disease mechanism, but most PD cases are sporadic rather than familial; environmental factors have long been suspected to contribute to the disease. Although more than 90% of PD cases occur sporadically and are thought to be due, in part, to oxidative stress and mitochondrial dysfunction, the study of genetic mutations has provided great insight into the molecular mechanisms of PD. Furthermore, rotenone, a widely used pesticide, and paraquat and maneb cause a syndrome in rats and mice that mimics, both behaviorally and neurologically, the symptoms of PD. In the current review, we will discuss various aspects of gene-environment interaction that lead to progressive dopaminergic neurodegenration, mainly focusing on our current finding based on stress-mediated parkin dysfunction.

  15. Gene-environment interaction and covariation in schizophrenia: the role of obstetric complications.

    Science.gov (United States)

    Mittal, Vijay A; Ellman, Lauren M; Cannon, Tyrone D

    2008-11-01

    While genetic factors account for a significant proportion of liability to schizophrenia, a body of evidence attests to a significant environmental contribution. Understanding the mechanisms through which genetic and environmental factors coalesce in influencing schizophrenia is critical for elucidating the pathways underlying psychotic illness and for developing primary prevention strategies. Although obstetric complications (OCs) remain among the most well-documented environmental indicators of risk for schizophrenia, the pathogenic role they play in the etiology of schizophrenia continues to remain poorly understood. A question of major importance is do these factors result from a genetic diathesis to schizophrenia (as in gene-environment covariation), act additively or interactively with predisposing genes for the disorder in influencing disease risk, or independently cause disease onset? In this review, we evaluate 3 classes of OCs commonly related to schizophrenia including hypoxia-associated OCs, maternal infection during pregnancy, and maternal stress during pregnancy. In addition, we discuss several mechanisms by which OCs impact on genetically susceptible brain regions, increasing constitutional vulnerability to neuromaturational events and stressors later in life (ie, adolescence), which may in turn contribute to triggering psychosis.

  16. Evidence of gene-environment interactions between common breast cancer susceptibility loci and established environmental risk factors

    DEFF Research Database (Denmark)

    Nickels, Stefan; Truong, Thérèse; Hein, Rebecca

    2013-01-01

    Various common genetic susceptibility loci have been identified for breast cancer; however, it is unclear how they combine with lifestyle/environmental risk factors to influence risk. We undertook an international collaborative study to assess gene-environment interaction for risk of breast cance...

  17. Evidence of gene-environment interactions between common breast cancer susceptibility loci and established environmental risk factors

    NARCIS (Netherlands)

    Nickels, S.; Truong, T.; Hein, R.; Stevens, K.; Buck, K.; Behrens, S.; Eilber, U.; Schmidt, M.; Haberle, L.; Vrieling, A.; Gaudet, M.; Figueroa, J.; Schoof, N.; Spurdle, A.B.; Rudolph, A.; Fasching, P.A.; Hopper, J.L.; Makalic, E.; Schmidt, D.F.; Southey, M.C.; Beckmann, M.W.; Ekici, A.B.; Fletcher, O.; Gibson, L.; Idos, S. Silva; Peto, J.; Humphreys, M.K.; Wang, J; Cordina-Duverger, E.; Menegaux, F.; Nordestgaard, B.G.; Bojesen, S.E.; Lanng, C.; Anton-Culver, H.; Ziogas, A.; Bernstein, L.; Clarke, C.A.; Brenner, H.; Muller, H.; Arndt, V.; Stegmaier, C.; Brauch, H.; Bruning, T.; Harth, V.; Genica, N.; Mannermaa, A.; Kataja, V.; Kosma, V.M.; Hartikainen, J.M.; Lambrechts, D.; Smeets, D.; Neven, P.; Paridaens, R.; Flesch-Janys, D.; Obi, N.; Wang-Gohrke, S.; Couch, F.J.; Olson, J.E.; Vachon, C.M.; Giles, G.G.; Severi, G.; Baglietto, L.; Offit, K.; John, E.M.; Miron, A.; Andrulis, I.L.; Knight, J.A.; Glendon, G.; Mulligan, A.M.; Chanock, S.J.; Lissowska, J.; Liu, J.; Cox, A; Cramp, H.; Connley, D.; Balasubramanian, S.; Dunning, A.M.; Shah, M.; Trentham-Dietz, A.; Newcomb, P.; Titus, L.; Egan, K.; Cahoon, E.K.; Rajaraman, P.; Sigurdson, A.J.; Doody, M.M.; Guenel, P.; Pharoah, P.D.; Schmidt, M.K.; Hall, P.; Easton, D.F.; Garcia-Closas, M.; Milne, R.L.; Chang-Claude, J.; et al.,

    2013-01-01

    Various common genetic susceptibility loci have been identified for breast cancer; however, it is unclear how they combine with lifestyle/environmental risk factors to influence risk. We undertook an international collaborative study to assess gene-environment interaction for risk of breast cancer.

  18. Using imputed genotype data in the joint score tests for genetic association and gene-environment interactions in case-control studies.

    Science.gov (United States)

    Song, Minsun; Wheeler, William; Caporaso, Neil E; Landi, Maria Teresa; Chatterjee, Nilanjan

    2018-03-01

    Genome-wide association studies (GWAS) are now routinely imputed for untyped single nucleotide polymorphisms (SNPs) based on various powerful statistical algorithms for imputation trained on reference datasets. The use of predicted allele counts for imputed SNPs as the dosage variable is known to produce valid score test for genetic association. In this paper, we investigate how to best handle imputed SNPs in various modern complex tests for genetic associations incorporating gene-environment interactions. We focus on case-control association studies where inference for an underlying logistic regression model can be performed using alternative methods that rely on varying degree on an assumption of gene-environment independence in the underlying population. As increasingly large-scale GWAS are being performed through consortia effort where it is preferable to share only summary-level information across studies, we also describe simple mechanisms for implementing score tests based on standard meta-analysis of "one-step" maximum-likelihood estimates across studies. Applications of the methods in simulation studies and a dataset from GWAS of lung cancer illustrate ability of the proposed methods to maintain type-I error rates for the underlying testing procedures. For analysis of imputed SNPs, similar to typed SNPs, the retrospective methods can lead to considerable efficiency gain for modeling of gene-environment interactions under the assumption of gene-environment independence. Methods are made available for public use through CGEN R software package. © 2017 WILEY PERIODICALS, INC.

  19. Metabolic syndrome, diabetes and atherosclerosis: Influence of gene-environment interaction

    International Nuclear Information System (INIS)

    Andreassi, Maria Grazia

    2009-01-01

    Despite remarkable progress in diagnosis and understanding of risk factors, cardiovascular disease (CVD) remains still the leading cause of morbidity and mortality in the world's developed countries. The metabolic syndrome, a cluster of risk factors (visceral obesity, insulin resistance, dyslipidaemia, and hypertension), is increasingly being recognized as a new risk factor for type 2 diabetes and atherosclerotic cardiovascular disease. Nevertheless, there is wide variation in both the occurrence of disease and age of onset, even in individuals who display very similar risk profiles. There is now compelling evidence that a complex interplay between genetic determinants and environmental factors (still largely unknown) is the reason for this large inter-individual variation in disease susceptibility. The purpose of the present review is to describe the current status of our knowledge concerning the gene-environment interactions potentially implicated in the pathogenesis of metabolic syndrome, diabetes and cardiovascular disease. It focuses predominantly on studies of genes (peroxisome proliferator-activated receptor-gamma, alcohol dehydrogenase type 1C, apolipoprotein E, glutathione S-transferases T1 and M1) that are known to be modified by dietary and lifestyle habits (fat diet, intake of alcohol and smoking habit). It also describes the limited current understanding of the role of genetic variants of xenobiotic metabolizing enzymes and their interactions with environmental toxicants. Additional studies are needed in order to clarify whether inter-individual differences in detoxification of environmental toxicants may have an essential role in the development of CVD and contribute to the emerging field of 'environmental cardiology'. Such knowledge may be particularly relevant for improving cardiovascular risk stratification and conceiving the development of 'personalized intervention program'.

  20. Metabolic syndrome, diabetes and atherosclerosis: Influence of gene-environment interaction

    Energy Technology Data Exchange (ETDEWEB)

    Andreassi, Maria Grazia, E-mail: andreas@ifc.cnr.it [CNR Institute of Clinical Physiology, G. Pasquinucci Hospital, Via Aurelia Sud, Massa (Italy)

    2009-07-10

    Despite remarkable progress in diagnosis and understanding of risk factors, cardiovascular disease (CVD) remains still the leading cause of morbidity and mortality in the world's developed countries. The metabolic syndrome, a cluster of risk factors (visceral obesity, insulin resistance, dyslipidaemia, and hypertension), is increasingly being recognized as a new risk factor for type 2 diabetes and atherosclerotic cardiovascular disease. Nevertheless, there is wide variation in both the occurrence of disease and age of onset, even in individuals who display very similar risk profiles. There is now compelling evidence that a complex interplay between genetic determinants and environmental factors (still largely unknown) is the reason for this large inter-individual variation in disease susceptibility. The purpose of the present review is to describe the current status of our knowledge concerning the gene-environment interactions potentially implicated in the pathogenesis of metabolic syndrome, diabetes and cardiovascular disease. It focuses predominantly on studies of genes (peroxisome proliferator-activated receptor-gamma, alcohol dehydrogenase type 1C, apolipoprotein E, glutathione S-transferases T1 and M1) that are known to be modified by dietary and lifestyle habits (fat diet, intake of alcohol and smoking habit). It also describes the limited current understanding of the role of genetic variants of xenobiotic metabolizing enzymes and their interactions with environmental toxicants. Additional studies are needed in order to clarify whether inter-individual differences in detoxification of environmental toxicants may have an essential role in the development of CVD and contribute to the emerging field of 'environmental cardiology'. Such knowledge may be particularly relevant for improving cardiovascular risk stratification and conceiving the development of 'personalized intervention program'.

  1. Gene-environment interactions linking air pollution and inflammation in Parkinson's disease.

    Science.gov (United States)

    Lee, Pei-Chen; Raaschou-Nielsen, Ole; Lill, Christina M; Bertram, Lars; Sinsheimer, Janet S; Hansen, Johnni; Ritz, Beate

    2016-11-01

    Both air pollution exposure and systemic inflammation have been linked to Parkinson's disease (PD). In the PASIDA study, 408 incident cases of PD diagnosed in 2006-2009 and their 495 population controls were interviewed and provided DNA samples. Markers of long term traffic related air pollution measures were derived from geographic information systems (GIS)-based modeling. Furthermore, we genotyped functional polymorphisms in genes encoding proinflammatory cytokines, namely rs1800629 in TNFα (tumor necrosis factor alpha) and rs16944 in IL1B (interleukin-1β). In logistic regression models, long-term exposure to NO 2 increased PD risk overall (odds ratio (OR)=1.06 per 2.94μg/m 3 increase, 95% CI=1.00-1.13). The OR for PD in individuals with high NO 2 exposure (≧75th percentile) and the AA genotype of IL1B rs16944 was 3.10 (95% CI=1.14-8.38) compared with individuals with lower NO 2 exposure (<75th percentile) and the GG genotype. The interaction term was nominally significant on the multiplicative scale (p=0.01). We did not find significant gene-environment interactions with TNF rs1800629. Our finds may provide suggestive evidence that a combination of traffic-related air pollution and genetic variation in the proinflammatory cytokine gene IL1B contribute to risk of developing PD. However, as statistical evidence was only modest in this large sample we cannot rule out that these results represent a chance finding, and additional replication efforts are warranted. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Neighborhood alcohol outlet density and genetic influences on alcohol use: evidence for gene-environment interaction.

    Science.gov (United States)

    Slutske, Wendy S; Deutsch, Arielle R; Piasecki, Thomas M

    2018-05-07

    Genetic influences on alcohol involvement are likely to vary as a function of the 'alcohol environment,' given that exposure to alcohol is a necessary precondition for genetic risk to be expressed. However, few gene-environment interaction studies of alcohol involvement have focused on characteristics of the community-level alcohol environment. The goal of this study was to examine whether living in a community with more alcohol outlets would facilitate the expression of the genetic propensity to drink in a genetically-informed national survey of United States young adults. The participants were 2434 18-26-year-old twin, full-, and half-sibling pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. Participants completed in-home interviews in which alcohol use was assessed. Alcohol outlet densities were extracted from state-level liquor license databases aggregated at the census tract level to derive the density of outlets. There was evidence that the estimates of genetic and environmental influences on alcohol use varied as a function of the density of alcohol outlets in the community. For example, the heritability of the frequency of alcohol use for those residing in a neighborhood with ten or more outlets was 74% (95% confidence limits = 55-94%), compared with 16% (95% confidence limits = 0-34%) for those in a neighborhood with zero outlets. This moderating effect of alcohol outlet density was not explained by the state of residence, population density, or neighborhood sociodemographic characteristics. The results suggest that living in a neighborhood with many alcohol outlets may be especially high-risk for those individuals who are genetically predisposed to frequently drink.

  3. The complement system: a gateway to gene-environment interactions in schizophrenia pathogenesis.

    Science.gov (United States)

    Nimgaonkar, V L; Prasad, K M; Chowdari, K V; Severance, E G; Yolken, R H

    2017-11-01

    The pathogenesis of schizophrenia is considered to be multi-factorial, with likely gene-environment interactions (GEI). Genetic and environmental risk factors are being identified with increasing frequency, yet their very number vastly increases the scope of possible GEI, making it difficult to identify them with certainty. Accumulating evidence suggests a dysregulated complement pathway among the pathogenic processes of schizophrenia. The complement pathway mediates innate and acquired immunity, and its activation drives the removal of damaged cells, autoantigens and environmentally derived antigens. Abnormalities in complement functions occur in many infectious and autoimmune disorders that have been linked to schizophrenia. Many older reports indicate altered serum complement activity in schizophrenia, though the data are inconclusive. Compellingly, recent genome-wide association studies suggest repeat polymorphisms incorporating the complement 4A (C4A) and 4B (C4B) genes as risk factors for schizophrenia. The C4A/C4B genetic associations have re-ignited interest not only in inflammation-related models for schizophrenia pathogenesis, but also in neurodevelopmental theories, because rodent models indicate a role for complement proteins in synaptic pruning and neurodevelopment. Thus, the complement system could be used as one of the 'staging posts' for a variety of focused studies of schizophrenia pathogenesis. They include GEI studies of the C4A/C4B repeat polymorphisms in relation to inflammation-related or infectious processes, animal model studies and tests of hypotheses linked to autoimmune diseases that can co-segregate with schizophrenia. If they can be replicated, such studies would vastly improve our understanding of pathogenic processes in schizophrenia through GEI analyses and open new avenues for therapy.

  4. DISC1 mouse models as a tool to decipher gene-environment interactions in psychiatric disorders

    Directory of Open Access Journals (Sweden)

    Tyler eCash-Padgett

    2013-09-01

    Full Text Available DISC1 was discovered in a Scottish pedigree in which a chromosomal translocation that breaks this gene segregates with psychiatric disorders, mainly depression and schizophrenia. Linkage and association studies in diverse populations support DISC1 as a susceptibility gene to a variety of neuropsychiatric disorders. Many Disc1 mouse models have been generated to study its neuronal functions. These mouse models display variable phenotypes, some of them relevant to schizophrenia, others to depression.The Disc1 mouse models are popular genetic models for studying gene-environment interactions in schizophrenia. Five different Disc1 models have been combined with environmental factors. The environmental stressors employed can be classified as either early immune activation or later social paradigms. These studies cover major time points along the neurodevelopmental trajectory: prenatal, early postnatal, adolescence, and adulthood. Various combinations of molecular, anatomical and behavioral methods have been used to assess the outcomes. Additionally, three of the studies sought to rescue the resulting abnormalities.Here we provide background on the environmental paradigms used, summarize the results of these studies combining Disc1 mouse models with environmental stressors and discuss what we can learn and how to proceed. A major question is how the genetic and environmental factors determine which psychiatric disorder will be clinically manifested. To address this we can take advantage of the many Disc1 models available and expose them to the same environmental stressor. The complementary experiment would be to expose the same model to different environmental stressors. DISC1 is an ideal gene for this approach, since in the Scottish pedigree the same chromosomal translocation results in different psychiatric conditions.

  5. The Association between Gene-Environment Interactions and Diseases Involving the Human GST Superfamily with SNP Variants

    Directory of Open Access Journals (Sweden)

    Antoinesha L. Hollman

    2016-03-01

    Full Text Available Exposure to environmental hazards has been associated with diseases in humans. The identification of single nucleotide polymorphisms (SNPs in human populations exposed to different environmental hazards, is vital for detecting the genetic risks of some important human diseases. Several studies in this field have been conducted on glutathione S-transferases (GSTs, a phase II detoxification superfamily, to investigate its role in the occurrence of diseases. Human GSTs consist of cytosolic and microsomal superfamilies that are further divided into subfamilies. Based on scientific search engines and a review of the literature, we have found a large amount of published articles on human GST super- and subfamilies that have greatly assisted in our efforts to examine their role in health and disease. Because of its polymorphic variations in relation to environmental hazards such as air pollutants, cigarette smoke, pesticides, heavy metals, carcinogens, pharmaceutical drugs, and xenobiotics, GST is considered as a significant biomarker. This review examines the studies on gene-environment interactions related to various diseases with respect to single nucleotide polymorphisms (SNPs found in the GST superfamily. Overall, it can be concluded that interactions between GST genes and environmental factors play an important role in human diseases.

  6. A model of gene-gene and gene-environment interactions and its implications for targeting environmental interventions by genotype

    Directory of Open Access Journals (Sweden)

    Wallace Helen M

    2006-10-01

    Full Text Available Abstract Background The potential public health benefits of targeting environmental interventions by genotype depend on the environmental and genetic contributions to the variance of common diseases, and the magnitude of any gene-environment interaction. In the absence of prior knowledge of all risk factors, twin, family and environmental data may help to define the potential limits of these benefits in a given population. However, a general methodology to analyze twin data is required because of the potential importance of gene-gene interactions (epistasis, gene-environment interactions, and conditions that break the 'equal environments' assumption for monozygotic and dizygotic twins. Method A new model for gene-gene and gene-environment interactions is developed that abandons the assumptions of the classical twin study, including Fisher's (1918 assumption that genes act as risk factors for common traits in a manner necessarily dominated by an additive polygenic term. Provided there are no confounders, the model can be used to implement a top-down approach to quantifying the potential utility of genetic prediction and prevention, using twin, family and environmental data. The results describe a solution space for each disease or trait, which may or may not include the classical twin study result. Each point in the solution space corresponds to a different model of genotypic risk and gene-environment interaction. Conclusion The results show that the potential for reducing the incidence of common diseases using environmental interventions targeted by genotype may be limited, except in special cases. The model also confirms that the importance of an individual's genotype in determining their risk of complex diseases tends to be exaggerated by the classical twin studies method, owing to the 'equal environments' assumption and the assumption of no gene-environment interaction. In addition, if phenotypes are genetically robust, because of epistasis

  7. Does parental divorce moderate the heritability of body dissatisfaction? An extension of previous gene-environment interaction effects.

    Science.gov (United States)

    O'Connor, Shannon M; Klump, Kelly L; VanHuysse, Jessica L; McGue, Matt; Iacono, William

    2016-02-01

    Previous research suggests that parental divorce moderates genetic influences on body dissatisfaction. Specifically, the heritability of body dissatisfaction is higher in children of divorced versus intact families, suggesting possible gene-environment interaction effects. However, prior research is limited to a single, self-reported measure of body dissatisfaction. The primary aim of this study was to examine whether these findings extend to a different dimension of body dissatisfaction: body image perceptions. Participants were 1,534 female twins from the Minnesota Twin Family Study, aged 16-20 years. The Body Rating Scale (BRS) was used to assess body image perceptions. Although BRS scores were heritable in twins from divorced and intact families, the heritability estimates in the divorced group were not significantly greater than estimates in the intact group. However, there were differences in nonshared environmental effects, where the magnitude of these environmental influences was larger in the divorced as compared with the intact families. Different dimensions of body dissatisfaction (i.e., negative self-evaluation versus body image perceptions) may interact with environmental risk, such as parental divorce, in discrete ways. Future research should examine this possibility and explore differential gene-environment interactions using diverse measures. © 2015 Wiley Periodicals, Inc.

  8. Gene-gene and gene-environment interactions in prostate, breast and colorectal cancer

    DEFF Research Database (Denmark)

    Kopp, Tine Iskov

    The incidence of cancer in the western world has increased steeply during the last 50 years. For three of the most prevalent cancer types in Denmark, prostate, breast and colorectal cancer (PC, BC and CRC, respectively), only a small fraction (1-15%) of the incidences are caused by highly penetrant...... in alcohol-related BC in postmenopausal women involving a specific polymorphism in PPARG (coding the peroxisome proliferatoractivated receptor (PPARγ)) and its interaction with the aromatase (encoded by CYP19A1) was investigated (Paper V-VI). The Danish prospective “Diet, Cancer and Health” cohort study...... as having strong influence on carcinogenesis. Therefore, very frequent, low effect polymorphisms may have a greater contribution on a population level in combination with environmental factors. Indeed, several dietary and life style factors are now well-established risk factors for different cancer types...

  9. Gene-environment interaction in the onset of eczema in infancy

    DEFF Research Database (Denmark)

    Bisgaard, Hans; Simpson, Angela; Palmer, Colin N A

    2008-01-01

    BACKGROUND: Loss-of-function variants in the gene encoding filaggrin (FLG) are major determinants of eczema. We hypothesized that weakening of the physical barrier in FLG-deficient individuals may potentiate the effect of environmental exposures. Therefore, we investigated whether there is an int......BACKGROUND: Loss-of-function variants in the gene encoding filaggrin (FLG) are major determinants of eczema. We hypothesized that weakening of the physical barrier in FLG-deficient individuals may potentiate the effect of environmental exposures. Therefore, we investigated whether...... there is an interaction between FLG loss-of-function mutations with environmental exposures (pets and dust mites) in relation to the development of eczema. METHODS AND FINDINGS: We used data obtained in early life in a high-risk birth cohort in Denmark and replicated the findings in an unselected birth cohort...... in the United Kingdom. Primary outcome was age of onset of eczema; environmental exposures included pet ownership and mite and pet allergen levels. In Copenhagen (n = 379), FLG mutation increased the risk of eczema during the first year of life (hazard ratio [HR] 2.26, 95% confidence interval [CI] 1.27-4.00, p...

  10. Degenerative periodontal-diseases and oral osteonecrosis: The role of gene-environment interactions

    International Nuclear Information System (INIS)

    Baldi, D.; Izzotti, A.; Bonica, P.; Pera, P.; Pulliero, A.

    2009-01-01

    Chronic-degenerative dentistry diseases, including periodontal diseases and oral osteonecrosis, are widespread in human populations and represent a significant problem for public health. These diseases result from pathogenic mechanisms created by the interaction between environmental genotoxic risk-factors and genetic assets conferring individual susceptibility. Osteonecrosis occurs in subjects undergoing exposure to high doses of DNA-damaging agents for chemo- and radiotherapy of neoplastic diseases. In susceptible patients, ionizing radiation and biphosphonate-chemotherapy induce severe, progressive, and irreversible degeneration of facial bones, resulting in avascular necrosis of the jaw. This may also occur in patients receiving biphosphonate for osteoporosis therapy. Periodontal diseases include chronic, aggressive, and necrotizing periodontitis, often resulting in severe alteration of periodontal tissues and tooth loss. Cigarette smoking and chronic inflammation caused by specific bacteria are the main risk factors for periodontitis. Oxidative damage plays a fundamental pathogenic role, as established by detection of mitochondrial DNA damage in the gingival tissue of patients with periodontitis. Endogenous risk factors in dental diseases include polymorphisms for metabolic enzymes such as glutathione transferases M1 and T1, N-acetyl transferase 2, and CYP 1A1. Other genetic polymorphisms that confer susceptibility to dentistry diseases affect genes encoding metalloproteases (involved in periodontal tissue remodeling and degradation), cytokines (involved in inflammation), prothrombin, and DNA repair activities. These findings provide evidence that dentistry diseases are related to risk factors associated with environmental mutagenesis. This issue warrants future investigations aimed at improving oral health and preventing oral degenerative diseases using molecular and experimental approaches currently utilized in mutagenicity studies.

  11. Degenerative periodontal-diseases and oral osteonecrosis: The role of gene-environment interactions

    Energy Technology Data Exchange (ETDEWEB)

    Baldi, D. [Department of Medical, Biophysical, and Dentistry Sciences and Technologies, University of Genoa (Italy); Izzotti, A. [Department of Health Sciences, University of Genoa, Via A. Pastore 1 (Italy); Bonica, P.; Pera, P. [Department of Medical, Biophysical, and Dentistry Sciences and Technologies, University of Genoa (Italy); Pulliero, A., E-mail: alessandra.pulliero@unige.it [Department of Health Sciences, University of Genoa, Via A. Pastore 1 (Italy)

    2009-07-10

    Chronic-degenerative dentistry diseases, including periodontal diseases and oral osteonecrosis, are widespread in human populations and represent a significant problem for public health. These diseases result from pathogenic mechanisms created by the interaction between environmental genotoxic risk-factors and genetic assets conferring individual susceptibility. Osteonecrosis occurs in subjects undergoing exposure to high doses of DNA-damaging agents for chemo- and radiotherapy of neoplastic diseases. In susceptible patients, ionizing radiation and biphosphonate-chemotherapy induce severe, progressive, and irreversible degeneration of facial bones, resulting in avascular necrosis of the jaw. This may also occur in patients receiving biphosphonate for osteoporosis therapy. Periodontal diseases include chronic, aggressive, and necrotizing periodontitis, often resulting in severe alteration of periodontal tissues and tooth loss. Cigarette smoking and chronic inflammation caused by specific bacteria are the main risk factors for periodontitis. Oxidative damage plays a fundamental pathogenic role, as established by detection of mitochondrial DNA damage in the gingival tissue of patients with periodontitis. Endogenous risk factors in dental diseases include polymorphisms for metabolic enzymes such as glutathione transferases M1 and T1, N-acetyl transferase 2, and CYP 1A1. Other genetic polymorphisms that confer susceptibility to dentistry diseases affect genes encoding metalloproteases (involved in periodontal tissue remodeling and degradation), cytokines (involved in inflammation), prothrombin, and DNA repair activities. These findings provide evidence that dentistry diseases are related to risk factors associated with environmental mutagenesis. This issue warrants future investigations aimed at improving oral health and preventing oral degenerative diseases using molecular and experimental approaches currently utilized in mutagenicity studies.

  12. Conceptual shifts needed to understand the dynamic interactions of genes, environment, epigenetics, social processes, and behavioral choices.

    Science.gov (United States)

    Jackson, Fatimah L C; Niculescu, Mihai D; Jackson, Robert T

    2013-10-01

    Social and behavioral research in public health is often intimately tied to profound, but frequently neglected, biological influences from underlying genetic, environmental, and epigenetic events. The dynamic interplay between the life, social, and behavioral sciences often remains underappreciated and underutilized in addressing complex diseases and disorders and in developing effective remediation strategies. Using a case-study format, we present examples as to how the inclusion of genetic, environmental, and epigenetic data can augment social and behavioral health research by expanding the parameters of such studies, adding specificity to phenotypic assessments, and providing additional internal control in comparative studies. We highlight the important roles of gene-environment interactions and epigenetics as sources of phenotypic change and as a bridge between the life and social and behavioral sciences in the development of robust interdisciplinary analyses.

  13. Nature versus nurture: A systematic approach to elucidate gene-environment interactions in the development of myopic refractive errors.

    Science.gov (United States)

    Miraldi Utz, Virginia

    2017-01-01

    Myopia is the most common eye disorder and major cause of visual impairment worldwide. As the incidence of myopia continues to rise, the need to further understand the complex roles of molecular and environmental factors controlling variation in refractive error is of increasing importance. Tkatchenko and colleagues applied a systematic approach using a combination of gene set enrichment analysis, genome-wide association studies, and functional analysis of a murine model to identify a myopia susceptibility gene, APLP2. Differential expression of refractive error was associated with time spent reading for those with low frequency variants in this gene. This provides support for the longstanding hypothesis of gene-environment interactions in refractive error development.

  14. Assessment of Multifactor Gene-Environment Interactions and Ovarian Cancer Risk

    DEFF Research Database (Denmark)

    Usset, Joseph L; Raghavan, Rama; Tyrer, Jonathan P

    2016-01-01

    and non-obese women. METHODS: We considered interactions between 11,441 SNPs within 80 candidate genes related to hormone biosynthesis and metabolism and insulin-like growth factors with six hormone-related factors (oral contraceptive use, parity, endometriosis, tubal ligation, hormone replacement therapy...... Future work is needed to develop powerful statistical methods able to detect these complex interactions. IMPACT: Assessment of multifactor interaction is feasible, and, here, suggests that the relationship between genetic variants within candidate genes and hormone-related risk factors may vary EOC...

  15. Interaction between Social/Psychosocial Factors and Genetic Variants on Body Mass Index: A Gene-Environment Interaction Analysis in a Longitudinal Setting.

    Science.gov (United States)

    Zhao, Wei; Ware, Erin B; He, Zihuai; Kardia, Sharon L R; Faul, Jessica D; Smith, Jennifer A

    2017-09-29

    Obesity, which develops over time, is one of the leading causes of chronic diseases such as cardiovascular disease. However, hundreds of BMI (body mass index)-associated genetic loci identified through large-scale genome-wide association studies (GWAS) only explain about 2.7% of BMI variation. Most common human traits are believed to be influenced by both genetic and environmental factors. Past studies suggest a variety of environmental features that are associated with obesity, including socioeconomic status and psychosocial factors. This study combines both gene/regions and environmental factors to explore whether social/psychosocial factors (childhood and adult socioeconomic status, social support, anger, chronic burden, stressful life events, and depressive symptoms) modify the effect of sets of genetic variants on BMI in European American and African American participants in the Health and Retirement Study (HRS). In order to incorporate longitudinal phenotype data collected in the HRS and investigate entire sets of single nucleotide polymorphisms (SNPs) within gene/region simultaneously, we applied a novel set-based test for gene-environment interaction in longitudinal studies (LGEWIS). Childhood socioeconomic status (parental education) was found to modify the genetic effect in the gene/region around SNP rs9540493 on BMI in European Americans in the HRS. The most significant SNP (rs9540488) by childhood socioeconomic status interaction within the rs9540493 gene/region was suggestively replicated in the Multi-Ethnic Study of Atherosclerosis (MESA) ( p = 0.07).

  16. Interaction between Social/Psychosocial Factors and Genetic Variants on Body Mass Index: A Gene-Environment Interaction Analysis in a Longitudinal Setting

    Directory of Open Access Journals (Sweden)

    Wei Zhao

    2017-09-01

    Full Text Available Obesity, which develops over time, is one of the leading causes of chronic diseases such as cardiovascular disease. However, hundreds of BMI (body mass index-associated genetic loci identified through large-scale genome-wide association studies (GWAS only explain about 2.7% of BMI variation. Most common human traits are believed to be influenced by both genetic and environmental factors. Past studies suggest a variety of environmental features that are associated with obesity, including socioeconomic status and psychosocial factors. This study combines both gene/regions and environmental factors to explore whether social/psychosocial factors (childhood and adult socioeconomic status, social support, anger, chronic burden, stressful life events, and depressive symptoms modify the effect of sets of genetic variants on BMI in European American and African American participants in the Health and Retirement Study (HRS. In order to incorporate longitudinal phenotype data collected in the HRS and investigate entire sets of single nucleotide polymorphisms (SNPs within gene/region simultaneously, we applied a novel set-based test for gene-environment interaction in longitudinal studies (LGEWIS. Childhood socioeconomic status (parental education was found to modify the genetic effect in the gene/region around SNP rs9540493 on BMI in European Americans in the HRS. The most significant SNP (rs9540488 by childhood socioeconomic status interaction within the rs9540493 gene/region was suggestively replicated in the Multi-Ethnic Study of Atherosclerosis (MESA (p = 0.07.

  17. Blood lead levels, iron metabolism gene polymorphisms and homocysteine: a gene-environment interaction study.

    Science.gov (United States)

    Kim, Kyoung-Nam; Lee, Mee-Ri; Lim, Youn-Hee; Hong, Yun-Chul

    2017-12-01

    Homocysteine has been causally associated with various adverse health outcomes. Evidence supporting the relationship between lead and homocysteine levels has been accumulating, but most prior studies have not focused on the interaction with genetic polymorphisms. From a community-based prospective cohort, we analysed 386 participants (aged 41-71 years) with information regarding blood lead and plasma homocysteine levels. Blood lead levels were measured between 2001 and 2003, and plasma homocysteine levels were measured in 2007. Interactions of lead levels with 42 genotyped single-nucleotide polymorphisms (SNPs) in five genes ( TF , HFE , CBS , BHMT and MTR ) were assessed via a 2-degree of freedom (df) joint test and a 1-df interaction test. In secondary analyses using imputation, we further assessed 58 imputed SNPs in the TF and MTHFR genes. Blood lead concentrations were positively associated with plasma homocysteine levels (p=0.0276). Six SNPs in the TF and MTR genes were screened using the 2-df joint test, and among them, three SNPs in the TF gene showed interactions with lead with respect to homocysteine levels through the 1-df interaction test (plead levels. Blood lead levels were positively associated with plasma homocysteine levels measured 4-6 years later, and three SNPs in the TF gene modified the association. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  18. A Partial Least Square Approach for Modeling Gene-gene and Gene-environment Interactions When Multiple Markers Are Genotyped

    Science.gov (United States)

    Wang, Tao; Ho, Gloria; Ye, Kenny; Strickler, Howard; Elston, Robert C.

    2008-01-01

    Genetic association studies achieve an unprecedented level of resolution in mapping disease genes by genotyping dense SNPs in a gene region. Meanwhile, these studies require new powerful statistical tools that can optimally handle a large amount of information provided by genotype data. A question that arises is how to model interactions between two genes. Simply modeling all possible interactions between the SNPs in two gene regions is not desirable because a greatly increased number of degrees of freedom can be involved in the test statistic. We introduce an approach to reduce the genotype dimension in modeling interactions. The genotype compression of this approach is built upon the information on both the trait and the cross-locus gametic disequilibrium between SNPs in two interacting genes, in such a way as to parsimoniously model the interactions without loss of useful information in the process of dimension reduction. As a result, it improves power to detect association in the presence of gene-gene interactions. This approach can be similarly applied for modeling gene-environment interactions. We compare this method with other approaches: the corresponding test without modeling any interaction, that based on a saturated interaction model, that based on principal component analysis, and that based on Tukey’s 1-df model. Our simulations suggest that this new approach has superior power to that of the other methods. In an application to endometrial cancer case-control data from the Women’s Health Initiative (WHI), this approach detected AKT1 and AKT2 as being significantly associated with endometrial cancer susceptibility by taking into account their interactions with BMI. PMID:18615621

  19. Identification of new genetic susceptibility loci for breast cancer through consideration of gene-environment interactions

    DEFF Research Database (Denmark)

    Schoeps, Anja; Rudolph, Anja; Seibold, Petra

    2014-01-01

    recently proposed hybrid methods and a joint test of association and interaction. Analyses were adjusted for age, study, population stratification, and confounding factors as applicable. Three SNPs in two independent loci showed statistically significant association: SNPs rs10483028 and rs2242714......,475 cases and 34,786 controls of European ancestry from up to 23 studies in the Breast Cancer Association Consortium were included. Overall, 71,527 single nucleotide polymorphisms (SNPs), enriched for association with breast cancer, were tested for interaction with 10 environmental risk factors using three...... in perfect linkage disequilibrium on chromosome 21 and rs12197388 in ARID1B on chromosome 6. While rs12197388 was identified using the joint test with parity and with age at menarche (P-values = 3 × 10(-07)), the variants on chromosome 21 q22.12, which showed interaction with adult body mass index (BMI) in 8...

  20. Evidence for plasticity genotypes in a gene-gene-environment interaction : the TRAILS study

    NARCIS (Netherlands)

    Nederhof, E; Bouma, Esther; Riese, Harriette; Laceulle, Odilia; Ormel, J.; Oldehinkel, A.J.

    2010-01-01

    The purpose was to study how functional polymorphisms in the brain derived neurotrophic factor gene (BDNF val66met) and the serotonin transporter gene linked promotor region (5-HTTLPR) interact with childhood adversities in predicting Effortful Control. Effortful Control refers to the ability to

  1. The Behavioural Phenotype of Smith-Magenis Syndrome: Evidence for a Gene-Environment Interaction

    Science.gov (United States)

    Taylor, L.; Oliver, C.

    2008-01-01

    Background: Behaviour problems and a preference for adult contact are reported to be prominent in the phenotype of Smith-Magenis syndrome. In this study we examined the relationship between social interactions and self-injurious and aggressive/disruptive behaviour in Smith-Magenis syndrome to explore potential operant reinforcement of problem…

  2. Gene-Environment Interaction in Parkinson's Disease: Coffee, ADORA2A, and CYP1A2.

    Science.gov (United States)

    Chuang, Yu-Hsuan; Lill, Christina M; Lee, Pei-Chen; Hansen, Johnni; Lassen, Christina F; Bertram, Lars; Greene, Naomi; Sinsheimer, Janet S; Ritz, Beate

    2016-01-01

    Drinking caffeinated coffee has been reported to provide protection against Parkinson's disease (PD). Caffeine is an adenosine A2A receptor (encoded by the gene ADORA2A) antagonist that increases dopaminergic neurotransmission and Cytochrome P450 1A2 (gene: CYP1A2) metabolizes caffeine; thus, gene polymorphisms in ADORA2A and CYP1A2 may influence the effect coffee consumption has on PD risk. In a population-based case-control study (PASIDA) in Denmark (1,556 PD patients and 1,606 birth year- and gender-matched controls), we assessed interactions between lifetime coffee consumption and 3 polymorphisms in ADORA2A and CYP1A2 for all subjects, and incident and prevalent PD cases separately using logistic regression models. We also conducted a meta-analysis combining our results with those from previous studies. We estimated statistically significant interactions for ADORA2A rs5760423 and heavy vs. light coffee consumption in incident (OR interaction = 0.66 [95% CI 0.46-0.94], p = 0.02) but not prevalent PD. We did not observe interactions for CYP1A2 rs762551 and rs2472304 in incident or prevalent PD. In meta-analyses, PD associations with daily coffee consumption were strongest among carriers of variant alleles in both ADORA2A and CYP1A2. We corroborated results from a previous report that described interactions between ADORA2A and CYP1A2 polymorphisms and coffee consumption. Our results also suggest that survivor bias may affect results of studies that enroll prevalent PD cases. © 2017 S. Karger AG, Basel.

  3. Gene-environment interaction between the oxytocin receptor (OXTR) gene and parenting behaviour on children's theory of mind.

    Science.gov (United States)

    Wade, Mark; Hoffmann, Thomas J; Jenkins, Jennifer M

    2015-12-01

    Theory of mind (ToM) is the ability to interpret and understand human behaviour by representing the mental states of others. Like many human capacities, ToM is thought to develop through both complex biological and socialization mechanisms. However, no study has examined the joint effect of genetic and environmental influences on ToM. This study examined how variability in the oxytocin receptor gene (OXTR) and parenting behavior--two widely studied factors in ToM development-interacted to predict ToM in pre-school-aged children. Participants were 301 children who were part of an ongoing longitudinal birth cohort study. ToM was assessed at age 4.5 using a previously validated scale. Parenting was assessed through observations of mothers' cognitively sensitive behaviours. Using a family-based association design, it was suggestive that a particular variant (rs11131149) interacted with maternal cognitive sensitivity on children's ToM (P = 0.019). More copies of the major allele were associated with higher ToM as a function of increasing cognitive sensitivity. A sizeable 26% of the variability in ToM was accounted for by this interaction. This study provides the first empirical evidence of gene-environment interactions on ToM, supporting the notion that genetic factors may be modulated by potent environmental influences early in development. © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  4. BDNF Val66Met polymorphism, life stress and depression: A meta-analysis of gene-environment interaction.

    Science.gov (United States)

    Zhao, Mingzhe; Chen, Lu; Yang, Jiarun; Han, Dong; Fang, Deyu; Qiu, Xiaohui; Yang, Xiuxian; Qiao, Zhengxue; Ma, Jingsong; Wang, Lin; Jiang, Shixiang; Song, Xuejia; Zhou, Jiawei; Zhang, Jian; Chen, Mingqi; Qi, Dong; Yang, Yanjie; Pan, Hui

    2018-02-01

    Depression is thought to be multifactorial in etiology, including genetic and environmental components. While a number of gene-environment interaction studies have been carried out, meta-analyses are scarce. The present meta-analysis aimed to quantify evidence on the interaction between brain-derived neurotrophic factor (BDNF) Val66Met polymorphism and stress in depression. Included were 31 peer-reviewed with a pooled total of 21060 participants published before October 2016 and literature searches were conducted using PubMed, Wolters Kluwer, Web of Science, EBSCO, Elsevier Science Direct and Baidu Scholar databases. The results indicated that the Met allele of BDNF Val66Met polymorphism significantly moderated the relationship between stress and depression (Z=2.666, p = 0.003). The results of subgroup analysis concluded that stressful life events and childhood adversity separately interacted with the Met allele of BDNF Val66Met polymorphism in depression (Z = 2.552, p = 0.005; Z = 1.775, p = 0.03). The results could be affected by errors or bias in primary studies which had small sample sizes with relatively lower statistic power. We could not estimate how strong the interaction effect between gene and environment was. We found evidence that supported the hypothesis that BDNF Val66Met polymorphism moderated the relationship between stress and depression, despite the fact that many included individual studies did not show this effect. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Gene-Environment Interactions in the Development of Complex Disease Phenotypes

    Directory of Open Access Journals (Sweden)

    Kenneth Olden

    2008-03-01

    Full Text Available The lack of knowledge about the earliest events in disease development is due to the multi-factorial nature of disease risk. This information gap is the consequence of the lack of appreciation for the fact that most diseases arise from the complex interactions between genes and the environment as a function of the age or stage of development of the individual. Whether an environmental exposure causes illness or not is dependent on the efficiency of the so-called “environmental response machinery” (i.e., the complex of metabolic pathways that can modulate response to environmental perturbations that one has inherited. Thus, elucidating the causes of most chronic diseases will require an understanding of both the genetic and environmental contribution to their etiology. Unfortunately, the exploration of the relationship between genes and the environment has been hampered in the past by the limited knowledge of the human genome, and by the inclination of scientists to study disease development using experimental models that consider exposure to a single environmental agent. Rarely in the past were interactions between multiple genes or between genes and environmental agents considered in studies of human disease etiology. The most critical issue is how to relate exposure-disease association studies to pathways and mechanisms. To understand how genes and environmental factors interact to perturb biological pathways to cause injury or disease, scientists will need tools with the capacity to monitor the global expression of thousands of genes, proteins and metabolites simultaneously. The generation of such data in multiple species can be used to identify conserved and functionally significant genes and pathways involved in geneenvironment interactions. Ultimately, it is this knowledge that will be used to guide agencies such as the U.S. Department of Health and Human Services in decisions regarding biomedical research funding

  6. Gene Environment Interactions and Predictors of Colorectal Cancer in Family-Based, Multi-Ethnic Groups

    Directory of Open Access Journals (Sweden)

    S. Pamela K. Shiao

    2018-02-01

    Full Text Available For the personalization of polygenic/omics-based health care, the purpose of this study was to examine the gene–environment interactions and predictors of colorectal cancer (CRC by including five key genes in the one-carbon metabolism pathways. In this proof-of-concept study, we included a total of 54 families and 108 participants, 54 CRC cases and 54 matched family friends representing four major racial ethnic groups in southern California (White, Asian, Hispanics, and Black. We used three phases of data analytics, including exploratory, family-based analyses adjusting for the dependence within the family for sharing genetic heritage, the ensemble method, and generalized regression models for predictive modeling with a machine learning validation procedure to validate the results for enhanced prediction and reproducibility. The results revealed that despite the family members sharing genetic heritage, the CRC group had greater combined gene polymorphism rates than the family controls (p < 0.05, on MTHFR C677T, MTR A2756G, MTRR A66G, and DHFR 19 bp except MTHFR A1298C. Four racial groups presented different polymorphism rates for four genes (all p < 0.05 except MTHFR A1298C. Following the ensemble method, the most influential factors were identified, and the best predictive models were generated by using the generalized regression models, with Akaike’s information criterion and leave-one-out cross validation methods. Body mass index (BMI and gender were consistent predictors of CRC for both models when individual genes versus total polymorphism counts were used, and alcohol use was interactive with BMI status. Body mass index status was also interactive with both gender and MTHFR C677T gene polymorphism, and the exposure to environmental pollutants was an additional predictor. These results point to the important roles of environmental and modifiable factors in relation to gene–environment interactions in the prevention of CRC.

  7. Gene-environment interactions in cancer epidemiology: a National Cancer Institute Think Tank report.

    Science.gov (United States)

    Hutter, Carolyn M; Mechanic, Leah E; Chatterjee, Nilanjan; Kraft, Peter; Gillanders, Elizabeth M

    2013-11-01

    Cancer risk is determined by a complex interplay of genetic and environmental factors. Genome-wide association studies (GWAS) have identified hundreds of common (minor allele frequency [MAF] > 0.05) and less common (0.01 Think Tank" on January 10-11, 2012. The objective of the Think Tank was to facilitate discussions on (1) the state of the science, (2) the goals of G × E interaction studies in cancer epidemiology, and (3) opportunities for developing novel study designs and analysis tools. This report summarizes the Think Tank discussion, with a focus on contemporary approaches to the analysis of G × E interactions. Selecting the appropriate methods requires first identifying the relevant scientific question and rationale, with an important distinction made between analyses aiming to characterize the joint effects of putative or established genetic and environmental factors and analyses aiming to discover novel risk factors or novel interaction effects. Other discussion items include measurement error, statistical power, significance, and replication. Additional designs, exposure assessments, and analytical approaches need to be considered as we move from the current small number of success stories to a fuller understanding of the interplay of genetic and environmental factors. © 2013 WILEY PERIODICALS, INC.

  8. Gene-environment interaction in Major Depression: focus on experience-dependent biological systems

    Directory of Open Access Journals (Sweden)

    Nicola eLopizzo

    2015-05-01

    Full Text Available Major Depressive Disorder (MDD is a multifactorial and polygenic disorder, where multiple and partially overlapping sets of susceptibility genes interact each other and with the environment, predisposing individuals to the development of the illness. Thus, MDD results from a complex interplay of vulnerability genes and environmental factors that act cumulatively throughout individual's lifetime. Among these environmental factors, stressful life experiences, especially those occurring early in life, have been suggested to exert a crucial impact on brain development, leading to permanent functional changes that may contribute to life long risk for mental health outcomes. In this review we will discuss how genetic variants (polymorphisms, SNPs within genes operating in neurobiological systems that mediate stress response and synaptic plasticity, can impact, by themselves, the vulnerability risk for MDD; we will also consider how this MDD risk can be further modulated when gene X environment interaction is taken into account. Finally, we will discuss the role of epigenetic mechanisms, and in particular of DNA methylation and miRNAs expression changes, in mediating the effect of the stress on the vulnerability risk to develop MDD. Taken together, in this review we aim to underlie the role of genetic and epigenetic processes involved in stress and neuroplasticity related biological systems on development of MDD after exposure to early life stress, thereby building the basis for future research and clinical interventions.

  9. Evidence of gene-environment interactions between common breast cancer susceptibility loci and established environmental risk factors.

    Directory of Open Access Journals (Sweden)

    Stefan Nickels

    Full Text Available Various common genetic susceptibility loci have been identified for breast cancer; however, it is unclear how they combine with lifestyle/environmental risk factors to influence risk. We undertook an international collaborative study to assess gene-environment interaction for risk of breast cancer. Data from 24 studies of the Breast Cancer Association Consortium were pooled. Using up to 34,793 invasive breast cancers and 41,099 controls, we examined whether the relative risks associated with 23 single nucleotide polymorphisms were modified by 10 established environmental risk factors (age at menarche, parity, breastfeeding, body mass index, height, oral contraceptive use, menopausal hormone therapy use, alcohol consumption, cigarette smoking, physical activity in women of European ancestry. We used logistic regression models stratified by study and adjusted for age and performed likelihood ratio tests to assess gene-environment interactions. All statistical tests were two-sided. We replicated previously reported potential interactions between LSP1-rs3817198 and parity (Pinteraction = 2.4 × 10(-6 and between CASP8-rs17468277 and alcohol consumption (Pinteraction = 3.1 × 10(-4. Overall, the per-allele odds ratio (95% confidence interval for LSP1-rs3817198 was 1.08 (1.01-1.16 in nulliparous women and ranged from 1.03 (0.96-1.10 in parous women with one birth to 1.26 (1.16-1.37 in women with at least four births. For CASP8-rs17468277, the per-allele OR was 0.91 (0.85-0.98 in those with an alcohol intake of <20 g/day and 1.45 (1.14-1.85 in those who drank ≥ 20 g/day. Additionally, interaction was found between 1p11.2-rs11249433 and ever being parous (Pinteraction = 5.3 × 10(-5, with a per-allele OR of 1.14 (1.11-1.17 in parous women and 0.98 (0.92-1.05 in nulliparous women. These data provide first strong evidence that the risk of breast cancer associated with some common genetic variants may vary with environmental risk factors.

  10. Social Integration and Sleep Disturbance: A Gene-Environment Interaction Study

    Directory of Open Access Journals (Sweden)

    David A. Sbarra

    2016-03-01

    Full Text Available Objective: Low levels of perceived social integration, or loneliness, are associated with increased risk for a range of poor health outcomes. Sleep disturbance plays a central role in the evolutionary theory of loneliness, which provides a mechanistic account of how low levels of social integration may negatively impact health. No studies, however, have examined whether the association between social integration and sleep disturbance is consistent with a causal effect after accounting for genes that are common to both variables.  Method: Using twin data ('N' = 905 twin pairs from the nationally-representative Midlife in the United States (MIDUS survey, I evaluated a series of bivariate twin models exploring whether the phenotypic association between low social integration and sleep disturbance can be explained by shared genetics. In addition, the current study specified a series of quantitative models for studying gene x environment (G X E interactions to determine whether the genetic and environmental influences on sleep disturbance differ as a function of social integration. Results: The phenotypic association between social integration and sleep disturbance was fully accounted for by genes that are common between the two variables, suggesting that within-twin pair differences in social integration do not exert a causal influence on sleep disturbance. Social integration, however, moderated the non-shared environmental influence on sleep disturbances, with the greatest environmental influences observed at the lowest levels of social integration. Conclusions: The results of this study suggest that an essential feature of the evolutionary model of loneliness may need refinement or elaboration. The moderation findings are discussed in terms of the fit with a stress-buffering model of social support in which environmental influences on sleep disturbance are strongest when social resources are low.

  11. Gene-gene, gene-environment, gene-nutrient interactions and single nucleotide polymorphisms of inflammatory cytokines.

    Science.gov (United States)

    Nadeem, Amina; Mumtaz, Sadaf; Naveed, Abdul Khaliq; Aslam, Muhammad; Siddiqui, Arif; Lodhi, Ghulam Mustafa; Ahmad, Tausif

    2015-05-15

    Inflammation plays a significant role in the etiology of type 2 diabetes mellitus (T2DM). The rise in the pro-inflammatory cytokines is the essential step in glucotoxicity and lipotoxicity induced mitochondrial injury, oxidative stress and beta cell apoptosis in T2DM. Among the recognized markers are interleukin (IL)-6, IL-1, IL-10, IL-18, tissue necrosis factor-alpha (TNF-α), C-reactive protein, resistin, adiponectin, tissue plasminogen activator, fibrinogen and heptoglobins. Diabetes mellitus has firm genetic and very strong environmental influence; exhibiting a polygenic mode of inheritance. Many single nucleotide polymorphisms (SNPs) in various genes including those of pro and anti-inflammatory cytokines have been reported as a risk for T2DM. Not all the SNPs have been confirmed by unifying results in different studies and wide variations have been reported in various ethnic groups. The inter-ethnic variations can be explained by the fact that gene expression may be regulated by gene-gene, gene-environment and gene-nutrient interactions. This review highlights the impact of these interactions on determining the role of single nucleotide polymorphism of IL-6, TNF-α, resistin and adiponectin in pathogenesis of T2DM.

  12. Genetic risk for violent behavior and environmental exposure to disadvantage and violent crime: the case for gene-environment interaction.

    Science.gov (United States)

    Barnes, J C; Jacobs, Bruce A

    2013-01-01

    Despite mounds of evidence to suggest that neighborhood structural factors predict violent behavior, almost no attention has been given to how these influences work synergistically (i.e., interact) with an individual's genetic propensity toward violent behavior. Indeed, two streams of research have, heretofore, flowed independently of one another. On one hand, criminologists have underscored the importance of neighborhood context in the etiology of violence. On the other hand, behavioral geneticists have argued that individual-level genetic propensities are important for understanding violence. The current study seeks to integrate these two compatible frameworks by exploring gene-environment interactions (GxE). Two GxEs were examined and supported by the data (i.e., the National Longitudinal Study of Adolescent Health). Using a scale of genetic risk based on three dopamine genes, the analysis revealed that genetic risk had a greater influence on violent behavior when the individual was also exposed to neighborhood disadvantage or when the individual was exposed to higher violent crime rates. The relevance of these findings for criminological theorizing was considered.

  13. I just ran a thousand analyses: benefits of multiple testing in understanding equivocal evidence on gene-environment interactions.

    Directory of Open Access Journals (Sweden)

    Vera E Heininga

    Full Text Available In psychiatric genetics research, the volume of ambivalent findings on gene-environment interactions (G x E is growing at an accelerating pace. In response to the surging suspicions of systematic distortion, we challenge the notion of chance capitalization as a possible contributor. Beyond qualifying multiple testing as a mere methodological issue that, if uncorrected, leads to chance capitalization, we advance towards illustrating the potential benefits of multiple tests in understanding equivocal evidence in genetics literature.We focused on the interaction between the serotonin-transporter-linked promotor region (5-HTTLPR and childhood adversities with regard to depression. After testing 2160 interactions with all relevant measures available within the Dutch population study of adolescents TRAILS, we calculated percentages of significant (p < .05 effects for several subsets of regressions. Using chance capitalization (i.e. overall significance rate of 5% alpha and randomly distributed findings as a competing hypothesis, we expected more significant effects in the subsets of regressions involving: 1 interview-based instead of questionnaire-based measures; 2 abuse instead of milder childhood adversities; and 3 early instead of later adversities. Furthermore, we expected equal significance percentages across 4 male and female subsamples, and 5 various genotypic models of 5-HTTLPR.We found differences in the percentages of significant interactions among the subsets of analyses, including those regarding sex-specific subsamples and genetic modeling, but often in unexpected directions. Overall, the percentage of significant interactions was 7.9% which is only slightly above the 5% that might be expected based on chance.Taken together, multiple testing provides a novel approach to better understand equivocal evidence on G x E, showing that methodological differences across studies are a likely reason for heterogeneity in findings - but chance

  14. Evidence for gene-environment interaction in a genome wide study of isolated, non-syndromic cleft palate

    Science.gov (United States)

    Beaty, Terri H.; Ruczinski, Ingo; Murray, Jeffrey C.; Marazita, Mary L.; Munger, Ronald G.; Hetmanski, Jacqueline B.; Murray, Tanda; Redett, Richard J.; Fallin, M. Daniele; Liang, Kung Yee; Wu, Tao; Patel, Poorav J.; Jin, Sheng C.; Zhang, Tian Xiao; Schwender, Holger; Wu-Chou, Yah Huei; Chen, Philip K; Chong, Samuel S; Cheah, Felicia; Yeow, Vincent; Ye, Xiaoqian; Wang, Hong; Huang, Shangzhi; Jabs, Ethylin W.; Shi, Bing; Wilcox, Allen J.; Lie, Rolv T.; Jee, Sun Ha; Christensen, Kaare; Doheny, Kimberley F.; Pugh, Elizabeth W.; Ling, Hua; Scott, Alan F.

    2011-01-01

    Non-syndromic cleft palate (CP) is a common birth defect with a complex and heterogeneous etiology involving both genetic and environmental risk factors. We conducted a genome wide association study (GWAS) using 550 case-parent trios, ascertained through a CP case collected in an international consortium. Family based association tests of single nucleotide polymorphisms (SNP) and three common maternal exposures (maternal smoking, alcohol consumption and multivitamin supplementation) were used in a combined 2 df test for gene (G) and gene-environment (G×E) interaction simultaneously, plus a separate 1 df test for G×E interaction alone. Conditional logistic regression models were used to estimate effects on risk to exposed and unexposed children. While no SNP achieved genome wide significance when considered alone, markers in several genes attained or approached genome wide significance when G×E interaction was included. Among these, MLLT3 and SMC2 on chromosome 9 showed multiple SNPs resulting in increased risk if the mother consumed alcohol during the peri-conceptual period (3 months prior to conception through the first trimester). TBK1 on chr. 12 and ZNF236 on chr. 18 showed multiple SNPs associated with higher risk of CP in the presence of maternal smoking. Additional evidence of reduced risk due to G×E interaction in the presence of multivitamin supplementation was observed for SNPs in BAALC on chr. 8. These results emphasize the need to consider G×E interaction when searching for genes influencing risk to complex and heterogeneous disorders, such as non-syndromic CP. PMID:21618603

  15. Estimating genetic effect sizes under joint disease-endophenotype models in presence of gene-environment interactions

    Directory of Open Access Journals (Sweden)

    Alexandre eBureau

    2015-07-01

    Full Text Available Effects of genetic variants on the risk of complex diseases estimated from association studies are typically small. Nonetheless, variants may have important effects in presence of specific levels of environmental exposures, and when a trait related to the disease (endophenotype is either normal or impaired. We propose polytomous and transition models to represent the relationship between disease, endophenotype, genotype and environmental exposure in family studies. Model coefficients were estimated using generalized estimating equations and were used to derive gene-environment interaction effects and genotype effects at specific levels of exposure. In a simulation study, estimates of the effect of a genetic variant were substantially higher when both an endophenotype and an environmental exposure modifying the variant effect were taken into account, particularly under transition models, compared to the alternative of ignoring the endophenotype. Illustration of the proposed modeling with the metabolic syndrome, abdominal obesity, physical activity and polymorphisms in the NOX3 gene in the Quebec Family Study revealed that the positive association of the A allele of rs1375713 with the metabolic syndrome at high levels of physical activity was only detectable in subjects without abdominal obesity, illustrating the importance of taking into account the abdominal obesity endophenotype in this analysis.

  16. Gene-environment interaction from international cohorts: impact on development and evolution of occupational and environmental lung and airway disease.

    Science.gov (United States)

    Gaffney, Adam; Christiani, David C

    2015-06-01

    Environmental and occupational pulmonary diseases impose a substantial burden of morbidity and mortality on the global population. However, it has been long observed that only some of those who are exposed to pulmonary toxicants go on to develop disease; increasingly, it is being recognized that genetic differences may underlie some of this person-to-person variability. Studies performed throughout the globe are demonstrating important gene-environment interactions for diseases as diverse as chronic beryllium disease, coal workers' pneumoconiosis, silicosis, asbestosis, byssinosis, occupational asthma, and pollution-associated asthma. These findings have, in many instances, elucidated the pathogenesis of these highly complex diseases. At the same time, however, translation of this research into clinical practice has, for good reasons, proceeded slowly. No genetic test has yet emerged with sufficiently robust operating characteristics to be clearly useful or practicable in an occupational or environmental setting. In addition, occupational genetic testing raises serious ethical and policy concerns. Therefore, the primary objective must remain ensuring that the workplace and the environment are safe for all. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  17. Gene-Environment Interaction Effects of Peer Deviance, Parental Knowledge and Stressful Life Events on Adolescent Alcohol Use.

    Science.gov (United States)

    Cooke, Megan E; Meyers, Jacquelyn L; Latvala, Antti; Korhonen, Tellervo; Rose, Richard J; Kaprio, Jaakko; Salvatore, Jessica E; Dick, Danielle M

    2015-10-01

    The purpose of this study was to address two methodological issues that have called into question whether previously reported gene-environment interaction (GxE) effects for adolescent alcohol use are 'real'. These issues are (1) the potential correlation between the environmental moderator and the outcome across twins and (2) non-linear transformations of the behavioral outcome. Three environments that have been previously studied (peer deviance, parental knowledge, and potentially stressful life events) were examined here. For each moderator (peer deviance, parental knowledge, and potentially stressful life events), a series of models was fit to both a raw and transformed measure of monthly adolescent alcohol use in a sample that included 825 dizygotic (DZ) and 803 monozygotic (MZ) twin pairs. The results showed that the moderating effect of peer deviance was robust to transformation, and that although the significance of moderating effects of parental knowledge and potentially stressful life events were dependent on the scale of the adolescent alcohol use outcome, the overall results were consistent across transformation. In addition, the findings did not vary across statistical models. The consistency of the peer deviance results and the shift of the parental knowledge and potentially stressful life events results between trending and significant, shed some light on why previous findings for certain moderators have been inconsistent and emphasize the importance of considering both methodological issues and previous findings when conducting and interpreting GxE analyses.

  18. Assessing the joint effect of population stratification and sample selection in studies of gene-gene (environment interactions

    Directory of Open Access Journals (Sweden)

    Cheng KF

    2012-01-01

    Full Text Available Abstract Background It is well known that the presence of population stratification (PS may cause the usual test in case-control studies to produce spurious gene-disease associations. However, the impact of the PS and sample selection (SS is less known. In this paper, we provide a systematic study of the joint effect of PS and SS under a more general risk model containing genetic and environmental factors. We provide simulation results to show the magnitude of the bias and its impact on type I error rate of the usual chi-square test under a wide range of PS level and selection bias. Results The biases to the estimation of main and interaction effect are quantified and then their bounds derived. The estimated bounds can be used to compute conservative p-values for the association test. If the conservative p-value is smaller than the significance level, we can safely claim that the association test is significant regardless of the presence of PS or not, or if there is any selection bias. We also identify conditions for the null bias. The bias depends on the allele frequencies, exposure rates, gene-environment odds ratios and disease risks across subpopulations and the sampling of the cases and controls. Conclusion Our results show that the bias cannot be ignored even the case and control data were matched in ethnicity. A real example is given to illustrate application of the conservative p-value. These results are useful to the genetic association studies of main and interaction effects.

  19. Case-only gene-environment interaction between ALAD tagSNPs and occupational lead exposure in prostate cancer.

    Science.gov (United States)

    Neslund-Dudas, Christine; Levin, Albert M; Rundle, Andrew; Beebe-Dimmer, Jennifer; Bock, Cathryn H; Nock, Nora L; Jankowski, Michelle; Datta, Indrani; Krajenta, Richard; Dou, Q Ping; Mitra, Bharati; Tang, Deliang; Rybicki, Benjamin A

    2014-05-01

    Black men have historically had higher blood lead levels than white men in the U.S. and have the highest incidence of prostate cancer in the world. Inorganic lead has been classified as a probable human carcinogen. Lead (Pb) inhibits delta-aminolevulinic acid dehydratase (ALAD), a gene recently implicated in other genitourinary cancers. The ALAD enzyme is involved in the second step of heme biosynthesis and is an endogenous inhibitor of the 26S proteasome, a master system for protein degradation and a current target of cancer therapy. Using a case-only study design, we assessed potential gene-environment (G × E) interactions between lifetime occupational Pb exposure and 11 tagSNPs within ALAD in black (N = 260) and white (N = 343) prostate cancer cases. Two ALAD tagSNPs in high linkage disequilibrium showed significant interaction with high Pb exposure among black cases (rs818684 interaction odds ratio or IOR = 2.73, 95% CI 1.43-5.22, P = 0.002; rs818689 IOR = 2.20, 95% CI 1.15-4.21, P = 0.017) and an additional tagSNP, rs2761016, showed G × E interaction with low Pb exposure (IOR = 2.08, 95% CI 1.13-3.84, P = 0.019). Further, the variant allele of rs818684 was associated with a higher Gleason grade in those with high Pb exposure among both blacks (OR 3.96, 95% CI 1.01-15.46, P = 0.048) and whites (OR 2.95, 95% CI 1.18-7.39, P = 0.020). Genetic variation in ALAD may modify associations between Pb and prostate cancer. Additional studies of ALAD, Pb, and prostate cancer are warranted and should include black men. Prostate 74:637-646, 2014. © 2014 Wiley Periodicals, Inc. © 2014 Wiley Periodicals, Inc.

  20. Culture as a mediator of gene-environment interaction: Cultural consonance, childhood adversity, a 2A serotonin receptor polymorphism, and depression in urban Brazil.

    Science.gov (United States)

    Dressler, William W; Balieiro, Mauro C; Ferreira de Araújo, Luiza; Silva, Wilson A; Ernesto Dos Santos, José

    2016-07-01

    Research on gene-environment interaction was facilitated by breakthroughs in molecular biology in the late 20th century, especially in the study of mental health. There is a reliable interaction between candidate genes for depression and childhood adversity in relation to mental health outcomes. The aim of this paper is to explore the role of culture in this process in an urban community in Brazil. The specific cultural factor examined is cultural consonance, or the degree to which individuals are able to successfully incorporate salient cultural models into their own beliefs and behaviors. It was hypothesized that cultural consonance in family life would mediate the interaction of genotype and childhood adversity. In a study of 402 adult Brazilians from diverse socioeconomic backgrounds, conducted from 2011 to 2014, the interaction of reported childhood adversity and a polymorphism in the 2A serotonin receptor was associated with higher depressive symptoms. Further analysis showed that the gene-environment interaction was mediated by cultural consonance in family life, and that these effects were more pronounced in lower social class neighborhoods. The findings reinforce the role of the serotonergic system in the regulation of stress response and learning and memory, and how these processes in turn interact with environmental events and circumstances. Furthermore, these results suggest that gene-environment interaction models should incorporate a wider range of environmental experience and more complex pathways to better understand how genes and the environment combine to influence mental health outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Multiple Gene-Environment Interactions on the Angiogenesis Gene-Pathway Impact Rectal Cancer Risk and Survival

    Directory of Open Access Journals (Sweden)

    Noha Sharafeldin

    2017-09-01

    Full Text Available Characterization of gene-environment interactions (GEIs in cancer is limited. We aimed at identifying GEIs in rectal cancer focusing on a relevant biologic process involving the angiogenesis pathway and relevant environmental exposures: cigarette smoking, alcohol consumption, and animal protein intake. We analyzed data from 747 rectal cancer cases and 956 controls from the Diet, Activity and Lifestyle as a Risk Factor for Rectal Cancer study. We applied a 3-step analysis approach: first, we searched for interactions among single nucleotide polymorphisms on the pathway genes; second, we searched for interactions among the genes, both steps using Logic regression; third, we examined the GEIs significant at the 5% level using logistic regression for cancer risk and Cox proportional hazards models for survival. Permutation-based test was used for multiple testing adjustment. We identified 8 significant GEIs associated with risk among 6 genes adjusting for multiple testing: TNF (OR = 1.85, 95% CI: 1.10, 3.11, TLR4 (OR = 2.34, 95% CI: 1.38, 3.98, and EGR2 (OR = 2.23, 95% CI: 1.04, 4.78 with smoking; IGF1R (OR = 1.69, 95% CI: 1.04, 2.72, TLR4 (OR = 2.10, 95% CI: 1.22, 3.60 and EGR2 (OR = 2.12, 95% CI: 1.01, 4.46 with alcohol; and PDGFB (OR = 1.75, 95% CI: 1.04, 2.92 and MMP1 (OR = 2.44, 95% CI: 1.24, 4.81 with protein. Five GEIs were associated with survival at the 5% significance level but not after multiple testing adjustment: CXCR1 (HR = 2.06, 95% CI: 1.13, 3.75 with smoking; and KDR (HR = 4.36, 95% CI: 1.62, 11.73, TLR2 (HR = 9.06, 95% CI: 1.14, 72.11, EGR2 (HR = 2.45, 95% CI: 1.42, 4.22, and EGFR (HR = 6.33, 95% CI: 1.95, 20.54 with protein. GEIs between angiogenesis genes and smoking, alcohol, and animal protein impact rectal cancer risk. Our results support the importance of considering the biologic hypothesis to characterize GEIs associated with cancer outcomes.

  2. Multiple analytical approaches reveal distinct gene-environment interactions in smokers and non smokers in lung cancer.

    Directory of Open Access Journals (Sweden)

    Rakhshan Ihsan

    SULT1A1 Arg213His and EPHX1 Tyr113His in smokers and SULT1A1 Arg213His with GSTP1 Ile105Val and CYP1A1*2C in nonsmokers. These results identified distinct gene-gene and gene environment interactions in smokers and non-smokers, which confirms the importance of multifactorial interaction in risk assessment of lung cancer.

  3. How much can a large population study on genes, environments, their interactions and common diseases contribute to the health of the American people?

    Science.gov (United States)

    Chaufan, Claudia

    2007-10-01

    I offer a critical perspective on a large-scale population study on gene-environment interactions and common diseases proposed by the US Secretary of Health and Human Services' Advisory Committee on Genetics, Health, and Society (SACGHS). I argue that for scientific and policy reasons this and similar studies have little to add to current knowledge about how to prevent, treat, or decrease inequalities in common diseases, all of which are major claims of the proposal. I use diabetes as an exemplar of the diseases that the study purports to illuminate. I conclude that the question is not whether the study will meet expectations or whether the current emphasis on a genetic paradigm is real or imagined, desirable or not. Rather, the question is why, given the flaws of the science underwriting the study, its assumptions remain unchallenged. Future research should investigate the reasons for this immunity from criticism and for the popularity of this and similar projects among laypersons as well as among intellectuals.

  4. The Cumulative Effect of Gene-Gene and Gene-Environment Interactions on the Risk of Prostate Cancer in Chinese Men

    Directory of Open Access Journals (Sweden)

    Ming Liu

    2016-01-01

    Full Text Available Prostate cancer (PCa is a multifactorial disease involving complex genetic and environmental factors interactions. Gene-gene and gene-environment interactions associated with PCa in Chinese men are less studied. We explored the association between 36 SNPs and PCa in 574 subjects from northern China. Body mass index (BMI, smoking, and alcohol consumption were determined through self-administered questionnaires in 134 PCa patients. Then gene-gene and gene-environment interactions among the PCa-associated SNPs were analyzed using the generalized multifactor dimensionality reduction (GMDR and logistic regression methods. Allelic and genotypic association analyses showed that six variants were associated with PCa and the cumulative effect suggested men who carried any combination of 1, 2, or ≥3 risk genotypes had a gradually increased PCa risk (odds ratios (ORs = 1.79–4.41. GMDR analysis identified the best gene-gene interaction model with scores of 10 for both the cross-validation consistency and sign tests. For gene-environment interactions, rs6983561 CC and rs16901966 GG in individuals with a BMI ≥ 28 had ORs of 7.66 (p = 0.032 and 5.33 (p = 0.046, respectively. rs7679673 CC + CA and rs12653946 TT in individuals that smoked had ORs of 2.77 (p = 0.007 and 3.11 (p = 0.024, respectively. rs7679673 CC in individuals that consumed alcohol had an OR of 4.37 (p = 0.041. These results suggest that polymorphisms, either individually or by interacting with other genes or environmental factors, contribute to an increased risk of PCa.

  5. Genetic susceptibility loci, environmental exposures, and Parkinson's disease: a case-control study of gene-environment interactions.

    Science.gov (United States)

    Chung, Sun Ju; Armasu, Sebastian M; Anderson, Kari J; Biernacka, Joanna M; Lesnick, Timothy G; Rider, David N; Cunningham, Julie M; Ahlskog, J Eric; Frigerio, Roberta; Maraganore, Demetrius M

    2013-06-01

    Prior studies causally linked mutations in SNCA, MAPT, and LRRK2 genes with familial Parkinsonism. Genome-wide association studies have demonstrated association of single nucleotide polymorphisms (SNPs) in those three genes with sporadic Parkinson's disease (PD) susceptibility worldwide. Here we investigated the interactions between SNPs in those three susceptibility genes and environmental exposures (pesticides application, tobacco smoking, coffee drinking, and alcohol drinking) also associated with PD susceptibility. Pairwise interactions between environmental exposures and 18 variants (16 SNPs and two variable number tandem repeats, or "VNTRs") in SNCA, MAPT and LRRK2, were investigated using data from 1098 PD cases from the upper Midwest, USA and 1098 matched controls. Environmental exposures were assessed using a validated telephone interview script. Five pairwise interactions had uncorrected P-values coffee drinking × MAPT H1/H2 haplotype or MAPT rs16940806, and alcohol drinking × MAPT rs2435211. None of these interactions remained significant after Bonferroni correction. Secondary analyses in strata defined by type of control (sibling or unrelated), sex, or age at onset of the case also did not identify significant interactions after Bonferroni correction. This study documented limited pairwise interactions between established genetic and environmental risk factors for PD; however, the associations were not significant after correction for multiple testing. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Enhancing the gene-environment interaction framework through a quasi-experimental research design: evidence from differential responses to September 11.

    Science.gov (United States)

    Fletcher, Jason M

    2014-01-01

    This article uses a gene-environment interaction framework to examine the differential responses to an objective external stressor based on genetic variation in the production of depressive symptoms. This article advances the literature by utilizing a quasi-experimental environmental exposure design, as well as a regression discontinuity design, to control for seasonal trends, which limit the potential for gene-environment correlation and allow stronger causal claims. Replications are attempted for two prominent genes (5-HTT and MAOA), and three additional genes are explored (DRD2, DRD4, and DAT1). This article provides evidence of a main effect of 9/11 on reports of feelings of sadness and fails to replicate a common finding of interaction using 5-HTT but does show support for interaction with MAOA in men. It also provides new evidence that variation in the DRD4 gene modifies an individual's response to the exposure, with individuals with no 7-repeats found to have a muted response.

  7. Neuregulin 1: a prime candidate for research into gene-environment interactions in schizophrenia? Insights from genetic rodent models

    Directory of Open Access Journals (Sweden)

    Tim eKarl

    2013-08-01

    Full Text Available Schizophrenia is a multi-factorial disease characterized by a high heritability and environmental risk factors. In recent years, an increasing number of researchers worldwide have started investigating the ‘two-hit hypothesis’ of schizophrenia predicting that genetic and environmental risk factors (GxE interactively cause the development of the disorder. This work is starting to produce valuable new animal models and reveal novel insights into the pathophysiology of schizophrenia. This mini review will focus on recent advancements in the field made by challenging mutant and transgenic rodent models for the schizophrenia candidate gene neuregulin 1 (NRG1 with particular environmental factors. It will outline results obtained from mouse and rat models for various Nrg1 isoforms/isoform types (e.g. transmembrane domain Nrg1, Type II Nrg1, which have been exposed to different forms of stress (acute versus chronic, restraint versus social and housing conditions (standard laboratory versus minimally enriched housing. These studies suggest Nrg1 as a prime candidate for GxE interactions in schizophrenia rodent models and that the use of rodent models will enable a better understanding of GxE interactions and the underlying mechanisms.

  8. Gene-environment interaction: Does fluoride influence the reproductive hormones in male farmers modified by ERα gene polymorphisms?

    Science.gov (United States)

    Ma, Qiang; Huang, Hui; Sun, Long; Zhou, Tong; Zhu, Jingyuan; Cheng, Xuemin; Duan, Lijv; Li, Zhiyuan; Cui, Liuxin; Ba, Yue

    2017-12-01

    The occurrence of endemic fluorosis is derived from high fluoride levels in drinking water and industrial fumes or dust. Reproductive disruption is also a major harm caused by fluoride exposure besides dental and skeletal lesions. However, few studies focus on the mechanism of fluoride exposure on male reproductive function, especially the possible interaction of fluoride exposure and gene polymorphism on male reproductive hormones. Therefore, we conducted a cross-sectional study in rural areas of Henan province in China to explore the interaction between the estrogen receptor alpha (ERα) gene and fluoride exposure on reproductive hormone levels in male farmers living in the endemic fluorosis villages. The results showed that fluoride exposure significantly increased the serum level of estradiol in the hypothalamic-pituitary-testicular (HPT) axis in male farmers. Moreover, the observations indicated that fluoride exposure and genetic markers had an interaction on serum concentration of follicle-stimulating hormone and estradiol, and the interaction among different loci of the ERα gene could impact the serum testosterone level. Findings in the present work suggest that chronic fluoride exposure in drinking water could modulate the levels of reproductive hormones in males living in endemic fluorosis areas, and the interaction between fluoride exposure and ERα polymorphisms might affect the serum levels of hormones in the HPT axis in male farmers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. A partial least-square approach for modeling gene-gene and gene-environment interactions when multiple markers are genotyped.

    Science.gov (United States)

    Wang, Tao; Ho, Gloria; Ye, Kenny; Strickler, Howard; Elston, Robert C

    2009-01-01

    Genetic association studies achieve an unprecedented level of resolution in mapping disease genes by genotyping dense single nucleotype polymorphisms (SNPs) in a gene region. Meanwhile, these studies require new powerful statistical tools that can optimally handle a large amount of information provided by genotype data. A question that arises is how to model interactions between two genes. Simply modeling all possible interactions between the SNPs in two gene regions is not desirable because a greatly increased number of degrees of freedom can be involved in the test statistic. We introduce an approach to reduce the genotype dimension in modeling interactions. The genotype compression of this approach is built upon the information on both the trait and the cross-locus gametic disequilibrium between SNPs in two interacting genes, in such a way as to parsimoniously model the interactions without loss of useful information in the process of dimension reduction. As a result, it improves power to detect association in the presence of gene-gene interactions. This approach can be similarly applied for modeling gene-environment interactions. We compare this method with other approaches, the corresponding test without modeling any interaction, that based on a saturated interaction model, that based on principal component analysis, and that based on Tukey's one-degree-of-freedom model. Our simulations suggest that this new approach has superior power to that of the other methods. In an application to endometrial cancer case-control data from the Women's Health Initiative, this approach detected AKT1 and AKT2 as being significantly associated with endometrial cancer susceptibility by taking into account their interactions with body mass index.

  10. Measuring the genetic influence on human life span: gene-environment interaction and sex-specific genetic effects

    DEFF Research Database (Denmark)

    Tan, Qihua; De Benedictis, G; Yashin, Annatoli

    2001-01-01

    New approaches are needed to explore the different ways in which genes affect the human life span. One needs to assess the genetic effects themselves, as well as gene–environment interactions and sex dependency. In this paper, we present a new model that combines both genotypic and demographicinf......New approaches are needed to explore the different ways in which genes affect the human life span. One needs to assess the genetic effects themselves, as well as gene–environment interactions and sex dependency. In this paper, we present a new model that combines both genotypic...

  11. A gene-environment interaction analysis of plasma selenium with prevalent and incident diabetes: The Hortega study.

    Science.gov (United States)

    Galan-Chilet, Inmaculada; Grau-Perez, Maria; De Marco, Griselda; Guallar, Eliseo; Martin-Escudero, Juan Carlos; Dominguez-Lucas, Alejandro; Gonzalez-Manzano, Isabel; Lopez-Izquierdo, Raul; Briongos-Figuero, Laisa Socorro; Redon, Josep; Chaves, Felipe Javier; Tellez-Plaza, Maria

    2017-08-01

    Selenium and single-nucleotide-polymorphisms in selenoprotein genes have been associated to diabetes. However, the interaction of selenium with genetic variation in diabetes and oxidative stress-related genes has not been evaluated as a potential determinant of diabetes risk. We evaluated the cross-sectional and prospective associations of plasma selenium concentrations with type 2 diabetes, and the interaction of selenium concentrations with genetic variation in candidate polymorphisms, in a representative sample of 1452 men and women aged 18-85 years from Spain. The geometric mean of plasma selenium levels in the study sample was 84.2µg/L. 120 participants had diabetes at baseline. Among diabetes-free participants who were not lost during the follow-up (N=1234), 75 developed diabetes over time. The multivariable adjusted odds ratios (95% confidence interval) for diabetes prevalence comparing the second and third to the first tertiles of plasma selenium levels were 1.80 (1.03, 3.14) and 1.97 (1.14, 3.41), respectively. The corresponding hazard ratios (95% CI) for diabetes incidence were 1.76 (0.96, 3.22) and 1.80 (0.98, 3.31), respectively. In addition, we observed significant interactions between selenium and polymorphisms in PPARGC1A, and in genes encoding mitochondrial proteins, such as BCS1L and SDHA, and suggestive interactions of selenium with other genes related to selenoproteins and redox metabolism. Plasma selenium was positively associated with prevalent and incident diabetes. While the statistical interactions of selenium with polymorphisms involved in regulation of redox and insulin signaling pathways provide biological plausibility to the positive associations of selenium with diabetes, further research is needed to elucidate the causal pathways underlying these associations. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  12. Gene-environment interaction in Parkinson’s disease: coffee, ADORA2A, and CYP1A2

    Science.gov (United States)

    Chuang, Yu-Hsuan; Lill, Christina M.; Lee, Pei-Chen; Hansen, Johnni; Lassen, Christina Funch; Bertram, Lars; Greene, Naomi; Sinsheimer, Janet S.; Ritz, Beate

    2017-01-01

    Background and purpose Drinking caffeinated coffee has been reported to protect against Parkinson’s disease (PD). Caffeine is an adenosine A2A receptor (encoded by the gene ADORA2A) antagonist that increases dopaminergic neurotransmission and Cytochrome P450 1A2 (gene: CYP1A2) metabolizes caffeine, thus gene polymorphisms in ADORA2A and CYP1A2 may influence the effect coffee consumption has on PD risk. Methods In a population-based case control study (PASIDA) in Denmark (1,556 PD patients and 1,606 birth year- and sex- matched controls), we assessed interactions between lifetime coffee consumption and three polymorphisms in ADORA2A and CYP1A2 for all subjects and incident and prevalent PD cases separately using logistic regression models. We also conducted a meta-analysis combining our results with those from previous studies. Results We estimated statistically significant interactions for ADORA2A rs5760423 and heavy vs. light coffee consumption in incident (OR interaction=0.66 [0.46–0.94], p=0.02) but not prevalent PD. We did not observe interactions for CYP1A2 rs762551 and rs2472304 in incident or prevalent PD. In meta-analyses, PD associations with daily coffee consumption were strongest among carriers of variant alleles in both ADORA2A and CYP1A2. Conclusion We corroborated results from a previous report that described interactions between ADORA2A and CYP1A2 polymorphisms and coffee consumption. Our results also suggest that survivor bias may affect results of studies that enrol prevalent PD cases. PMID:28135712

  13. Identifying gene-environment interactions in schizophrenia: contemporary challenges for integrated, large-scale investigations

    NARCIS (Netherlands)

    van Os, Jim; Rutten, Bart P.; Myin-Germeys, Inez; Delespaul, Philippe; Viechtbauer, Wolfgang; van Zelst, Catherine; Bruggeman, Richard; Reininghaus, Ulrich; Morgan, Craig; Murray, Robin M.; Di Forti, Marta; McGuire, Philip; Valmaggia, Lucia R.; Kempton, Matthew J.; Gayer-Anderson, Charlotte; Hubbard, Kathryn; Beards, Stephanie; Stilo, Simona A.; Onyejiaka, Adanna; Bourque, Francois; Modinos, Gemma; Tognin, Stefania; Calem, Maria; O'Donovan, Michael C.; Owen, Michael J.; Holmans, Peter; Williams, Nigel; Craddock, Nicholas; Richards, Alexander; Humphreys, Isla; Meyer-Lindenberg, Andreas; Leweke, F. Markus; Tost, Heike; Akdeniz, Ceren; Rohleder, Cathrin; Bumb, J. Malte; Schwarz, Emanuel; Alptekin, Köksal; Üçok, Alp; Saka, Meram Can; Atbaşoğlu, E. Cem; Gülöksüz, Sinan; Gumus-Akay, Guvem; Cihan, Burçin; Karadağ, Hasan; Soygür, Haldan; Cankurtaran, Eylem Şahin; Ulusoy, Semra; Akdede, Berna; Binbay, Tolga; Ayer, Ahmet; Noyan, Handan; Karadayı, Gülşah; Akturan, Elçin; Ulaş, Halis; Arango, Celso; Parellada, Mara; Bernardo, Miguel; Sanjuán, Julio; Bobes, Julio; Arrojo, Manuel; Santos, Jose Luis; Cuadrado, Pedro; Rodríguez Solano, José Juan; Carracedo, Angel; García Bernardo, Enrique; Roldán, Laura; López, Gonzalo; Cabrera, Bibiana; Cruz, Sabrina; Díaz Mesa, Eva Ma; Pouso, María; Jiménez, Estela; Sánchez, Teresa; Rapado, Marta; González, Emiliano; Martínez, Covadonga; Sánchez, Emilio; Olmeda, Ma Soledad; de Haan, Lieuwe; Velthorst, Eva; van der Gaag, Mark; Selten, Jean-Paul; van Dam, Daniella; van der Ven, Elsje; van der Meer, Floor; Messchaert, Elles; Kraan, Tamar; Burger, Nadine; Leboyer, Marion; Szoke, Andrei; Schürhoff, Franck; Llorca, Pierre-Michel; Jamain, Stéphane; Tortelli, Andrea; Frijda, Flora; Vilain, Jeanne; Galliot, Anne-Marie; Baudin, Grégoire; Ferchiou, Aziz; Richard, Jean-Romain; Bulzacka, Ewa; Charpeaud, Thomas; Tronche, Anne-Marie; de Hert, Marc; van Winkel, Ruud; Decoster, Jeroen; Derom, Catherine; Thiery, Evert; Stefanis, Nikos C.; Sachs, Gabriele; Aschauer, Harald; Lasser, Iris; Winklbaur, Bernadette; Schlögelhofer, Monika; Riecher-Rössler, Anita; Borgwardt, Stefan; Walter, Anna; Harrisberger, Fabienne; Smieskova, Renata; Rapp, Charlotte; Ittig, Sarah; Soguel-Dit-Piquard, Fabienne; Studerus, Erich; Klosterkötter, Joachim; Ruhrmann, Stephan; Paruch, Julia; Julkowski, Dominika; Hilboll, Desiree; Sham, Pak C.; Cherny, Stacey S.; Chen, Eric Y. H.; Campbell, Desmond D.; Li, Miaoxin; Romeo-Casabona, Carlos María; Emaldi Cirión, Aitziber; Urruela Mora, Asier; Jones, Peter; Kirkbride, James; Cannon, Mary; Rujescu, Dan; Tarricone, Ilaria; Berardi, Domenico; Bonora, Elena; Seri, Marco; Marcacci, Thomas; Chiri, Luigi; Chierzi, Federico; Storbini, Viviana; Braca, Mauro; Minenna, Maria Gabriella; Donegani, Ivonne; Fioritti, Angelo; La Barbera, Daniele; La Cascia, Caterina Erika; Mulè, Alice; Sideli, Lucia; Sartorio, Rachele; Ferraro, Laura; Tripoli, Giada; Seminerio, Fabio; Marinaro, Anna Maria; McGorry, Patrick; Nelson, Barnaby; Amminger, G. Paul; Pantelis, Christos; Menezes, Paulo R.; del-Ben, Cristina M.; Gallo Tenan, Silvia H.; Shuhama, Rosana; Ruggeri, Mirella; Tosato, Sarah; Lasalvia, Antonio; Bonetto, Chiara; Ira, Elisa; Nordentoft, Merete; Krebs, Marie-Odile; Barrantes-Vidal, Neus; Cristóbal, Paula; Kwapil, Thomas R.; Brietzke, Elisa; Bressan, Rodrigo A.; Gadelha, Ary; Maric, Nadja P.; Andric, Sanja; Mihaljevic, Marina; Mirjanic, Tijana

    2014-01-01

    Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular

  14. Identifying Gene-Environment Interactions in Schizophrenia : Contemporary Challenges for Integrated, Large-scale Investigations

    NARCIS (Netherlands)

    van Os, Jim; Rutten, Bart P.; Myin-Germeys, Inez; Delespaul, Philippe; Viechtbauer, Wolfgang; van Zelst, Catherine; Bruggeman, Richard; Reininghaus, Ulrich; Morgan, Craig; Murray, Robin M.; Di Forti, Marta; McGuire, Philip; Valmaggia, Lucia R.; Kempton, Matthew J.; Gayer-Anderson, Charlotte; Hubbard, Kathryn; Beards, Stephanie; Stilo, Simona A.; Onyejiaka, Adanna; Bourque, Francois; Modinos, Gemma; Tognin, Stefania; Calem, Maria; O'Donovan, Michael C.; Owen, Michael J.; Holmans, Peter; Williams, Nigel; Craddock, Nicholas; Richards, Alexander; Humphreys, Isla; Meyer-Lindenberg, Andreas; Leweke, F. Markus; Tost, Heike; Akdeniz, Ceren; Rohleder, Cathrin; Bumb, J. Malte; Schwarz, Emanuel; Alptekin, Koksal; Ucok, Alp; Saka, Meram Can; Atbasoglu, E. Cem; Guloksuz, Sinan; Gumus-Akay, Guvem; Cihan, Burin; Karadag, Hasan; Soygur, Haldan; Cankurtaran, Eylem Sahin; Ulusoy, Semra; Akdede, Berna; Binbay, Tolga

    Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular

  15. Identifying Gene-Environment interactions in schizophrenia: Contemporary challenges for integrated, large-scale investigations

    NARCIS (Netherlands)

    European Network authors, o.a.; van der Gaag, M.

    2014-01-01

    Recent years have seen considerable progress in epidemiological and molecular genetic research into environmental and genetic factors in schizophrenia, but methodological uncertainties remain with regard to validating environmental exposures, and the population risk conferred by individual molecular

  16. Detection of gene-environment interactions in the presence of linkage disequilibrium and noise by using genetic risk scores with internal weights from elastic net regression.

    Science.gov (United States)

    Hüls, Anke; Ickstadt, Katja; Schikowski, Tamara; Krämer, Ursula

    2017-06-12

    For the analysis of gene-environment (GxE) interactions commonly single nucleotide polymorphisms (SNPs) are used to characterize genetic susceptibility, an approach that mostly lacks power and has poor reproducibility. One promising approach to overcome this problem might be the use of weighted genetic risk scores (GRS), which are defined as weighted sums of risk alleles of gene variants. The gold-standard is to use external weights from published meta-analyses. In this study, we used internal weights from the marginal genetic effects of the SNPs estimated by a multivariate elastic net regression and thereby provided a method that can be used if there are no external weights available. We conducted a simulation study for the detection of GxE interactions and compared power and type I error of single SNPs analyses with Bonferroni correction and corresponding analysis with unweighted and our weighted GRS approach in scenarios with six risk SNPs and an increasing number of highly correlated (up to 210) and noise SNPs (up to 840). Applying weighted GRS increased the power enormously in comparison to the common single SNPs approach (e.g. 94.2% vs. 35.4%, respectively, to detect a weak interaction with an OR ≈ 1.04 for six uncorrelated risk SNPs and n = 700 with a well-controlled type I error). Furthermore, weighted GRS outperformed the unweighted GRS, in particular in the presence of SNPs without any effect on the phenotype (e.g. 90.1% vs. 43.9%, respectively, when 20 noise SNPs were added to the six risk SNPs). This outperforming of the weighted GRS was confirmed in a real data application on lung inflammation in the SALIA cohort (n = 402). However, in scenarios with a high number of noise SNPs (>200 vs. 6 risk SNPs), larger sample sizes are needed to avoid an increased type I error, whereas a high number of correlated SNPs can be handled even in small samples (e.g. n = 400). In conclusion, weighted GRS with weights from the marginal genetic effects of the

  17. Influence of 5-HTT variation, childhood trauma and self-efficacy on anxiety traits: a gene-environment-coping interaction study.

    Science.gov (United States)

    Schiele, Miriam A; Ziegler, Christiane; Holitschke, Karoline; Schartner, Christoph; Schmidt, Brigitte; Weber, Heike; Reif, Andreas; Romanos, Marcel; Pauli, Paul; Zwanzger, Peter; Deckert, Jürgen; Domschke, Katharina

    2016-08-01

    Environmental vulnerability factors such as adverse childhood experiences in interaction with genetic risk variants, e.g., the serotonin transporter gene linked polymorphic region (5-HTTLPR), are assumed to play a role in the development of anxiety and affective disorders. However, positive influences such as general self-efficacy (GSE) may exert a compensatory effect on genetic disposition, environmental adversity, and anxiety traits. We, thus, assessed childhood trauma (Childhood Trauma Questionnaire, CTQ) and GSE in 678 adults genotyped for 5-HTTLPR/rs25531 and their interaction on agoraphobic cognitions (Agoraphobic Cognitions Questionnaire, ACQ), social anxiety (Liebowitz Social Anxiety Scale, LSAS), and trait anxiety (State-Trait Anxiety Inventory, STAI-T). The relationship between anxiety traits and childhood trauma was moderated by self-efficacy in 5-HTTLPR/rs25531 LALA genotype carriers: LALA probands maltreated as children showed high anxiety scores when self-efficacy was low, but low anxiety scores in the presence of high self-efficacy despite childhood maltreatment. Our results extend previous findings regarding anxiety-related traits showing an interactive relationship between 5-HTT genotype and adverse childhood experiences by suggesting coping-related measures to function as an additional dimension buffering the effects of a gene-environment risk constellation. Given that anxiety disorders manifest already early in childhood, this insight could contribute to the improvement of psychotherapeutic interventions by including measures strengthening self-efficacy and inform early targeted preventive interventions in at-risk populations, particularly within the crucial time window of childhood and adolescence.

  18. Gene-environment Interactions in Human Health: Case Studies and Strategies for developing new paradigms and research methodologies

    Directory of Open Access Journals (Sweden)

    Fatimah L.C. Jackson

    2014-08-01

    Full Text Available The synergistic effects of genes and the environment on health are explored in three case studies: adult lactase persistence, autism spectrum disorders, and the metabolic syndrome, providing examples of the interactive complexities underlying these phenotypes. Since the phenotypes are the initial targets of evolutionary processes, understanding the specific environmental contexts of the genetic, epigenetic, and proteomic changes associated with these phenotypes is essential in predicting their health implications. Robust databases must be developed on the local scale to deconstruct both the population substructure and the unique components of the environment that stimulate geographically-specific changes in gene expression patterns. To produce these databases and make valid predictions, new, locally-focused and information-dense models are needed that incorporate data on evolutionary ecology, environmental complexity, local geographic patterns of gene expression, and population substructure.

  19. Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders.

    Science.gov (United States)

    Yoshizaki, Kaichi; Furuse, Tamio; Kimura, Ryuichi; Tucci, Valter; Kaneda, Hideki; Wakana, Shigeharu; Osumi, Noriko

    2016-01-01

    Neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit and hyperactivity disorder (ADHD) have increased over the last few decades. These neurodevelopmental disorders are characterized by a complex etiology, which involves multiple genes and gene-environmental interactions. Various genes that control specific properties of neural development exert pivotal roles in the occurrence and severity of phenotypes associated with neurodevelopmental disorders. Moreover, paternal aging has been reported as one of the factors that contribute to the risk of ASD and ADHD. Here we report, for the first time, that paternal aging has profound effects on the onset of behavioral abnormalities in mice carrying a mutation of Pax6, a gene with neurodevelopmental regulatory functions. We adopted an in vitro fertilization approach to restrict the influence of additional factors. Comprehensive behavioral analyses were performed in Sey/+ mice (i.e., Pax6 mutant heterozygotes) born from in vitro fertilization of sperm taken from young or aged Sey/+ fathers. No body weight changes were found in the four groups, i.e., Sey/+ and wild type (WT) mice born to young or aged father. However, we found important differences in maternal separation-induced ultrasonic vocalizations of Sey/+ mice born from young father and in the level of hyperactivity of Sey/+ mice born from aged fathers in the open-field test, respectively, compared to WT littermates. Phenotypes of anxiety were observed in both genotypes born from aged fathers compared with those born from young fathers. No significant difference was found in social behavior and sensorimotor gating among the four groups. These results indicate that mice with a single genetic risk factor can develop different phenotypes depending on the paternal age. Our study advocates for serious considerations on the role of paternal aging in breeding strategies for animal studies.

  20. Paternal Aging Affects Behavior in Pax6 Mutant Mice: A Gene/Environment Interaction in Understanding Neurodevelopmental Disorders.

    Directory of Open Access Journals (Sweden)

    Kaichi Yoshizaki

    Full Text Available Neurodevelopmental disorders such as autism spectrum disorder (ASD and attention deficit and hyperactivity disorder (ADHD have increased over the last few decades. These neurodevelopmental disorders are characterized by a complex etiology, which involves multiple genes and gene-environmental interactions. Various genes that control specific properties of neural development exert pivotal roles in the occurrence and severity of phenotypes associated with neurodevelopmental disorders. Moreover, paternal aging has been reported as one of the factors that contribute to the risk of ASD and ADHD. Here we report, for the first time, that paternal aging has profound effects on the onset of behavioral abnormalities in mice carrying a mutation of Pax6, a gene with neurodevelopmental regulatory functions. We adopted an in vitro fertilization approach to restrict the influence of additional factors. Comprehensive behavioral analyses were performed in Sey/+ mice (i.e., Pax6 mutant heterozygotes born from in vitro fertilization of sperm taken from young or aged Sey/+ fathers. No body weight changes were found in the four groups, i.e., Sey/+ and wild type (WT mice born to young or aged father. However, we found important differences in maternal separation-induced ultrasonic vocalizations of Sey/+ mice born from young father and in the level of hyperactivity of Sey/+ mice born from aged fathers in the open-field test, respectively, compared to WT littermates. Phenotypes of anxiety were observed in both genotypes born from aged fathers compared with those born from young fathers. No significant difference was found in social behavior and sensorimotor gating among the four groups. These results indicate that mice with a single genetic risk factor can develop different phenotypes depending on the paternal age. Our study advocates for serious considerations on the role of paternal aging in breeding strategies for animal studies.

  1. Arsenic metabolism efficiency has a causal role in arsenic toxicity: Mendelian randomization and gene-environment interaction.

    Science.gov (United States)

    Pierce, Brandon L; Tong, Lin; Argos, Maria; Gao, Jianjun; Farzana, Jasmine; Roy, Shantanu; Paul-Brutus, Rachelle; Rahaman, Ronald; Rakibuz-Zaman, Muhammad; Parvez, Faruque; Ahmed, Alauddin; Quasem, Iftekhar; Hore, Samar K; Alam, Shafiul; Islam, Tariqul; Harjes, Judith; Sarwar, Golam; Slavkovich, Vesna; Gamble, Mary V; Chen, Yu; Yunus, Mohammad; Rahman, Mahfuzar; Baron, John A; Graziano, Joseph H; Ahsan, Habibul

    2013-12-01

    Arsenic exposure through drinking water is a serious global health issue. Observational studies suggest that individuals who metabolize arsenic efficiently are at lower risk for toxicities such as arsenical skin lesions. Using two single nucleotide polymorphisms(SNPs) in the 10q24.32 region (near AS3MT) that show independent associations with metabolism efficiency, Mendelian randomization can be used to assess whether the association between metabolism efficiency and skin lesions is likely to be causal. Using data on 2060 arsenic-exposed Bangladeshi individuals, we estimated associations for two 10q24.32 SNPs with relative concentrations of three urinary arsenic species (representing metabolism efficiency): inorganic arsenic (iAs), monomethylarsonic acid(MMA) and dimethylarsinic acid (DMA). SNP-based predictions of iAs%, MMA% and DMA% were tested for association with skin lesion status among 2483 cases and 2857 controls. Causal odds ratios for skin lesions were 0.90 (95% confidence interval[CI]: 0.87, 0.95), 1.19 (CI: 1.10, 1.28) and 1.23 (CI: 1.12, 1.36)for a one standard deviation increase in DMA%, MMA% and iAs%,respectively. We demonstrated genotype-arsenic interaction, with metabolism-related variants showing stronger associations with skin lesion risk among individuals with high arsenic exposure (synergy index: 1.37; CI: 1.11, 1.62). We provide strong evidence for a causal relationship between arsenic metabolism efficiency and skin lesion risk. Mendelian randomization can be used to assess the causal role of arsenic exposure and metabolism in a wide array of health conditions.exposure and metabolism in a wide array of health conditions.Developing interventions that increase arsenic metabolism efficiency are likely to reduce the impact of arsenic exposure on health.

  2. Nevoid basal cell carcinoma syndrome with medulloblastoma in an African-American boy: A rare case illustrating gene-environment interaction

    Energy Technology Data Exchange (ETDEWEB)

    Korczak, J.F.; Goldstein, A.M. [National Institutes of Health, Bethesda, MD (United States); Kase, R.G. [Westat Inc., Rockville, MD (United States)] [and others

    1997-03-31

    We present an 8-year-old African-American boy with medulloblastoma and nevoid basal cell carcinoma syndrome (NBCCS) who exhibited the radiosensitive response of basal cell carcinoma (BCC) formation in the area irradiated for medulloblastoma. Such a response is well-documented in Caucasian NBCCS patients with medulloblastoma. The propositus was diagnosed with medulloblastoma at the age of 2 years and underwent surgery, chemotherapy, and craniospinal irradiation. At the age of 6 years, he was diagnosed with NBCCS following his presentation with a large odontogenic keratocyst of the mandible, pits of the palms and soles and numerous BCCs in the area of the back and neck that had been irradiated previously for medulloblastoma. Examination of other relatives showed that the propositus mother also had NBCCS but was more mildly affected; in particular, she had no BCCs. This case illustrates complex gene-environment interaction, in that increased skin pigmentation in African-Americans is presumably protective against ultraviolet, but not ionizing, radiation. This case and other similar cases in the literature show the importance of considering NBCCS in the differential diagnosis of any patient who presents with a medulloblastoma, especially before the age of 5 years, and of examining other close relatives for signs of NBCCS to determine the patient`s at-risk status. Finally, for individuals who are radiosensitive, protocols that utilize chemotherapy in lieu of radiotherapy should be considered. 27 refs., 4 figs.

  3. The role of genes involved in neuroplasticity and neurogenesis in the observation of a gene-environment interaction (GxE) in schizophrenia.

    Science.gov (United States)

    Le Strat, Yann; Ramoz, Nicolas; Gorwood, Philip

    2009-05-01

    Schizophrenia is a multifactorial disease characterized by a high heritability. Several candidate genes have been suggested, with the strongest evidences for genes encoding dystrobrevin binding protein 1 (DTNBP1), neuregulin 1 (NRG1), neuregulin 1 receptor (ERBB4) and disrupted in schizophrenia 1 (DISC1), as well as several neurotrophic factors. These genes are involved in neuronal plasticity and play also a role in adult neurogenesis. Therefore, the genetic basis of schizophrenia could involve different factors more or less specifically required for neuroplasticity, including the synapse maturation, potentiation and plasticity as well as neurogenesis. Following the model of Knudson in tumors, we propose a two-hit hypothesis of schizophrenia. In this model of gene-environment interaction, a variant in a gene related to neurogenesis is transmitted to the descent (first hit), and, secondarily, an environmental factor occurs during the development of the central nervous system (second hit). Both of these vulnerability and trigger factors are probably necessary to generate a deficit in neurogenesis and therefore to cause schizophrenia. The literature supporting this gene x environment hypothesis is reviewed, with emphasis on some molecular pathways, raising the possibility to propose more specific molecular medicine.

  4. Confluence of genes, environment, development, and behavior in a post Genome-Wide Association Study world

    DEFF Research Database (Denmark)

    Vrieze, S. I.; Iacono, W. G.; McGue, M.

    2012-01-01

    This article serves to outline a research paradigm to investigate main effects and interactions of genes, environment, and development on behavior and psychiatric illness. We provide a historical context for candidate gene studies and genome-wide association studies, including benefits, limitations...

  5. Genes, Environment, and Human Behavior.

    Science.gov (United States)

    Bloom, Mark V.; Cutter, Mary Ann; Davidson, Ronald; Dougherty, Michael J.; Drexler, Edward; Gelernter, Joel; McCullough, Laurence B.; McInerney, Joseph D.; Murray, Jeffrey C.; Vogler, George P.; Zola, John

    This curriculum module explores genes, environment, and human behavior. This book provides materials to teach about the nature and methods of studying human behavior, raise some of the ethical and public policy dilemmas emerging from the Human Genome Project, and provide professional development for teachers. An extensive Teacher Background…

  6. Gene-Environment Interplay in Twin Models

    Science.gov (United States)

    Hatemi, Peter K.

    2013-01-01

    In this article, we respond to Shultziner’s critique that argues that identical twins are more alike not because of genetic similarity, but because they select into more similar environments and respond to stimuli in comparable ways, and that these effects bias twin model estimates to such an extent that they are invalid. The essay further argues that the theory and methods that undergird twin models, as well as the empirical studies which rely upon them, are unaware of these potential biases. We correct this and other misunderstandings in the essay and find that gene-environment (GE) interplay is a well-articulated concept in behavior genetics and political science, operationalized as gene-environment correlation and gene-environment interaction. Both are incorporated into interpretations of the classical twin design (CTD) and estimated in numerous empirical studies through extensions of the CTD. We then conduct simulations to quantify the influence of GE interplay on estimates from the CTD. Due to the criticism’s mischaracterization of the CTD and GE interplay, combined with the absence of any empirical evidence to counter what is presented in the extant literature and this article, we conclude that the critique does not enhance our understanding of the processes that drive political traits, genetic or otherwise. PMID:24808718

  7. Impact of variation in the BDNF gene on social stress sensitivity and the buffering impact of positive emotions: replication and extension of a gene-environment interaction.

    Science.gov (United States)

    van Winkel, Mark; Peeters, Frenk; van Winkel, Ruud; Kenis, Gunter; Collip, Dina; Geschwind, Nicole; Jacobs, Nele; Derom, Catherine; Thiery, Evert; van Os, Jim; Myin-Germeys, Inez; Wichers, Marieke

    2014-06-01

    A previous study reported that social stress sensitivity is moderated by the brain-derived-neurotrophic-factor(Val66Met) (BDNF rs6265) genotype. Additionally, positive emotions partially neutralize this moderating effect. The current study aimed to: (i) replicate in a new independent sample of subjects with residual depressive symptoms the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity, (ii) replicate the neutralizing impact of positive emotions, (iii) extend these analyses to other variations in the BDNF gene in the new independent sample and the original sample of non-depressed individuals. Previous findings were replicated in an experience sampling method (ESM) study. Negative Affect (NA) responses to social stress were stronger in "Val/Met" carriers of BDNF(Val66Met) compared to "Val/Val" carriers. Positive emotions neutralized the moderating effect of BDNF(Val66Met) genotype on social stress sensitivity in a dose-response fashion. Finally, two of four additional BDNF SNPs (rs11030101, rs2049046) showed similar moderating effects on social stress-sensitivity across both samples. The neutralizing effect of positive emotions on the moderating effects of these two additional SNPs was found in one sample. In conclusion, ESM has important advantages in gene-environment (GxE) research and may attribute to more consistent findings in future GxE research. This study shows how the impact of BDNF genetic variation on depressive symptoms may be explained by its impact on subtle daily life responses to social stress. Further, it shows that the generation of positive affect (PA) can buffer social stress sensitivity and partially undo the genetic susceptibility. Copyright © 2014 Elsevier B.V. and ECNP. All rights reserved.

  8. Investigating Molecular Interactions

    DEFF Research Database (Denmark)

    Clausen, Henrik Fanø

    2010-01-01

    ···π interactions are accommodated by electrostatic complementarity. The crystal structure of both the α- and the β-polymorph of hydroquinone is presented in Chapter 6 with focus on close intermolecular contacts between the molecules via Hirshfeld surface analysis. The charge density distribution of the empty β....... The last chapter of this dissertation presents the analysis of intermolecular interaction using both the Hirshfeld surface and charge density distribution of the acetonitrile β-hydroquinone clathrate. The local packing and related close contacts are examined by breakdown of the fingerprint plots revealing......, are also introduced, as a goal of the analysis of charge density distributions is to obtain further understanding of these macroscopic properties. Neutron diffraction will be used as a complementary tool to the X-ray diffraction experiment, as positional and thermal parameters of hydrogen atoms can...

  9. Gene-Environment Interplay in Common Complex Diseases: Forging an Integrative Model—Recommendations From an NIH Workshop

    Science.gov (United States)

    Bookman, Ebony B.; McAllister, Kimberly; Gillanders, Elizabeth; Wanke, Kay; Balshaw, David; Rutter, Joni; Reedy, Jill; Shaughnessy, Daniel; Agurs-Collins, Tanya; Paltoo, Dina; Atienza, Audie; Bierut, Laura; Kraft, Peter; Fallin, M. Daniele; Perera, Frederica; Turkheimer, Eric; Boardman, Jason; Marazita, Mary L.; Rappaport, Stephen M.; Boerwinkle, Eric; Suomi, Stephen J.; Caporaso, Neil E.; Hertz-Picciotto, Irva; Jacobson, Kristen C.; Lowe, William L.; Goldman, Lynn R.; Duggal, Priya; Gunnar, Megan R.; Manolio, Teri A.; Green, Eric D.; Olster, Deborah H.; Birnbaum, Linda S.

    2011-01-01

    Although it is recognized that many common complex diseases are a result of multiple genetic and environmental risk factors, studies of gene-environment interaction remain a challenge and have had limited success to date. Given the current state-of-the-science, NIH sought input on ways to accelerate investigations of gene-environment interplay in health and disease by inviting experts from a variety of disciplines to give advice about the future direction of gene-environment interaction studies. Participants of the NIH Gene-Environment Interplay Workshop agreed that there is a need for continued emphasis on studies of the interplay between genetic and environmental factors in disease and that studies need to be designed around a multifaceted approach to reflect differences in diseases, exposure attributes, and pertinent stages of human development. The participants indicated that both targeted and agnostic approaches have strengths and weaknesses for evaluating main effects of genetic and environmental factors and their interactions. The unique perspectives represented at the workshop allowed the exploration of diverse study designs and analytical strategies, and conveyed the need for an interdisciplinary approach including data sharing, and data harmonization to fully explore gene-environment interactions. Further, participants also emphasized the continued need for high-quality measures of environmental exposures and new genomic technologies in ongoing and new studies. PMID:21308768

  10. Gene-environment interaction affects substance P and neurokinin A in the entorhinal cortex and periaqueductal grey in a genetic animal model of depression: implications for the pathophysiology of depression

    DEFF Research Database (Denmark)

    Husum, Henriette; Wörtwein, Gitta; Andersson, Weronika

    2008-01-01

    Evidence implies a role for corticotropin-releasing hormone (CRH) and tachykinins, e.g. substance P (SP) and neurokinin A (NKA) in the pathophysiology of depression. We have previously shown that SP- and NKA-like immunoreactivity (-LI) concentrations were altered in the frontal cortex and striatum...... of the congenitally 'depressed' Flinders Sensitive Line (FSL) compared to the Flinders Resistant Line (FRL) control rats. It is also known that environmental stress may affect brain levels of tachykinins. In view of these results we decided to superimpose maternal deprivation, an early life environmental stressor......, onto the genetically predisposed 'depressed' FSL rats and the FRL control rats and use this paradigm as a model of gene-environment interaction. The adult animals were sacrificed, adrenal glands and brains dissected out and SP-, NKA- and CRH-LI levels were determined in ten discrete brain regions...

  11. A gene-environment investigation on personality traits in two independent clinical sets of adult patients with personality disorder and attention deficit/hyperactive disorder.

    Science.gov (United States)

    Jacob, Christian P; Nguyen, Thuy Trang; Dempfle, Astrid; Heine, Monika; Windemuth-Kieselbach, Christine; Baumann, Katarina; Jacob, Florian; Prechtl, Julian; Wittlich, Maike; Herrmann, Martin J; Gross-Lesch, Silke; Lesch, Klaus-Peter; Reif, Andreas

    2010-06-01

    While an interactive effect of genes with adverse life events is increasingly appreciated in current concepts of depression etiology, no data are presently available on interactions between genetic and environmental (G x E) factors with respect to personality and related disorders. The present study therefore aimed to detect main effects as well as interactions of serotonergic candidate genes (coding for the serotonin transporter, 5-HTT; the serotonin autoreceptor, HTR1A; and the enzyme which synthesizes serotonin in the brain, TPH2) with the burden of life events (#LE) in two independent samples consisting of 183 patients suffering from personality disorders and 123 patients suffering from adult attention deficit/hyperactivity disorder (aADHD). Simple analyses ignoring possible G x E interactions revealed no evidence for associations of either #LE or of the considered polymorphisms in 5-HTT and TPH2. Only the G allele of HTR1A rs6295 seemed to increase the risk of emotional-dramatic cluster B personality disorders (p = 0.019, in the personality disorder sample) and to decrease the risk of anxious-fearful cluster C personality disorders (p = 0.016, in the aADHD sample). We extended the initial simple model by taking a G x E interaction term into account, since this approach may better fit the data indicating that the effect of a gene is modified by stressful life events or, vice versa, that stressful life events only have an effect in the presence of a susceptibility genotype. By doing so, we observed nominal evidence for G x E effects as well as main effects of 5-HTT-LPR and the TPH2 SNP rs4570625 on the occurrence of personality disorders. Further replication studies, however, are necessary to validate the apparent complexity of G x E interactions in disorders of human personality.

  12. Response to angiotensin-converting enzyme inhibition is selectively blunted by high sodium in angiotensin-converting enzyme DD genotype: evidence for gene-environment interaction in healthy volunteers.

    Science.gov (United States)

    Lely, A Titia; Heerspink, Hiddo J Lambers; Zuurman, Mike; Visser, Folkert W; Kocks, Menno J A; Boomsma, Frans; Navis, Gerjan

    2010-12-01

    Renin-angiotensin-aldosterone system blockade is a cornerstone in cardiovascular protection. Angiotensin-converting enzyme (ACE)-DD genotype has been associated with resistance to angiotensin-converting enzyme inhibition (ACEi), but data are conflicting. As sodium intake modifies the effect of ACEi as well as the genotype-phenotype relationship, we hypothesize gene-environment interaction between sodium-status, the response to ACEi, and ACE genotype. Thirty-five male volunteers (26 ± 9 years; II n = 6, ID n = 18, DD n = 11) were studied during placebo and ACEi (double blind, enalapril 20 mg/day) on low [7 days 50 mmol Na/day (low salt)] and high [7 days 200 mmol Na/day (high salt)] sodium, with a washout of 6 weeks in-between. After each period mean arterial pressure (MAP) was measured before and during graded infusion of angiotensin II (Ang II). During high salt, ACEi reduced MAP in II and ID, but not in DD [II: 88 (78-94) versus 76 (72-88); ID: 87 (84-91) versus 83 (79-87); both P DD: 86 (82-96) versus 88 (80-90); ns, P DD: 84 (80-91) versus 81 (75-85); all P DD, with an 18% rise in MAP during the highest dose versus 22 and 31% in ID and II (P DD genotype during high salt, accompanied by blunted sensitivity to Ang II. Low salt corrects both abnormalities. Further analysis of this gene-environment interaction in patients may contribute to strategies for improvement of individual treatment efficacy.

  13. Genome-wide gene-environment study identifies glutamate receptor gene GRIN2A as a Parkinson's disease modifier gene via interaction with coffee.

    OpenAIRE

    Taye H Hamza; Honglei Chen; Erin M Hill-Burns; Shannon L Rhodes; Jennifer Montimurro; Denise M Kay; Albert Tenesa; Victoria I Kusel; Patricia Sheehan; Muthukrishnan Eaaswarkhanth; Dora Yearout; Ali Samii; John W Roberts; Pinky Agarwal; Yvette Bordelon

    2011-01-01

    Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD). We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC), and we performed a genome-wide association and interaction study (GWAIS), testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal compo...

  14. Operating Characteristics of Statistical Methods for Detecting Gene-by-Measured Environment Interaction in the Presence of Gene-Environment Correlation under Violations of Distributional Assumptions.

    Science.gov (United States)

    Van Hulle, Carol A; Rathouz, Paul J

    2015-02-01

    Accurately identifying interactions between genetic vulnerabilities and environmental factors is of critical importance for genetic research on health and behavior. In the previous work of Van Hulle et al. (Behavior Genetics, Vol. 43, 2013, pp. 71-84), we explored the operating characteristics for a set of biometric (e.g., twin) models of Rathouz et al. (Behavior Genetics, Vol. 38, 2008, pp. 301-315), for testing gene-by-measured environment interaction (GxM) in the presence of gene-by-measured environment correlation (rGM) where data followed the assumed distributional structure. Here we explore the effects that violating distributional assumptions have on the operating characteristics of these same models even when structural model assumptions are correct. We simulated N = 2,000 replicates of n = 1,000 twin pairs under a number of conditions. Non-normality was imposed on either the putative moderator or on the ultimate outcome by ordinalizing or censoring the data. We examined the empirical Type I error rates and compared Bayesian information criterion (BIC) values. In general, non-normality in the putative moderator had little impact on the Type I error rates or BIC comparisons. In contrast, non-normality in the outcome was often mistaken for or masked GxM, especially when the outcome data were censored.

  15. SLC6A1 gene involvement in susceptibility to attention-deficit/hyperactivity disorder: A case-control study and gene-environment interaction.

    Science.gov (United States)

    Yuan, Fang-Fen; Gu, Xue; Huang, Xin; Zhong, Yan; Wu, Jing

    2017-07-03

    Attention-deficit/hyperactivity disorder (ADHD) is an early onset childhood neurodevelopmental disorder with an estimated heritability of approximately 76%. We conducted a case-control study to explore the role of the SLC6A1 gene in ADHD. The genotypes of eight variants were determined using Sequenom MassARRAY technology. The participants in the study were 302 children with ADHD and 411 controls. ADHD symptoms were assessed using the Conners Parent Symptom Questionnaire. In our study, rs2944366 was consistently shown to be associated with the ADHD risk in the dominant model (odds ratio [OR]=0.554, 95% confidence interval [CI]=0.404-0.760), and nominally associated with Hyperactive index score (P=0.027). In addition, rs1170695 has been found to be associated with the ADHD risk in the addictive model (OR=1.457, 95%CI=1.173-1.809), while rs9990174 was associated with the Hyperactive index score (P=0.010). Intriguingly, gene-environmental interactions analysis consistently revealed the potential interactions of rs1170695 with blood lead (P mul =0.044) to modify the ADHD risk. Expression quantitative trait loci analysis suggested that these positive single nucleotide polymorphisms (SNPs) may mediate SLC6A1 gene expression. Therefore, our results suggest that selected SLC6A1 gene variants may have a significant effect on the ADHD risk. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Chronic exposure of mutant DISC1 mice to lead produces sex-dependent abnormalities consistent with schizophrenia and related mental disorders: a gene-environment interaction study.

    Science.gov (United States)

    Abazyan, Bagrat; Dziedzic, Jenifer; Hua, Kegang; Abazyan, Sofya; Yang, Chunxia; Mori, Susumu; Pletnikov, Mikhail V; Guilarte, Tomas R

    2014-05-01

    The glutamatergic hypothesis of schizophrenia suggests that hypoactivity of the N-methyl-D-aspartate receptor (NMDAR) is an important factor in the pathophysiology of schizophrenia and related mental disorders. The environmental neurotoxicant, lead (Pb(2+)), is a potent and selective antagonist of the NMDAR. Recent human studies have suggested an association between prenatal Pb(2+) exposure and the increased likelihood of schizophrenia later in life, possibly via interacting with genetic risk factors. In order to test this hypothesis, we examined the neurobehavioral consequences of interaction between Pb(2+) exposure and mutant disrupted in schizophrenia 1 (mDISC1), a risk factor for major psychiatric disorders. Mutant DISC1 and control mice born by the same dams were raised and maintained on a regular diet or a diet containing moderate levels of Pb(2+). Chronic, lifelong exposure of mDISC1 mice to Pb(2+) was not associated with gross developmental abnormalities but produced sex-dependent hyperactivity, exaggerated responses to the NMDAR antagonist, MK-801, mildly impaired prepulse inhibition of the acoustic startle, and enlarged lateral ventricles. Together, these findings support the hypothesis that environmental toxins could contribute to the pathogenesis of mental disease in susceptible individuals.

  17. Gene-environment effects on hippocampal neurodevelopment

    DEFF Research Database (Denmark)

    Rosenthal, Eva Helga

    Mental disorders like schizophrenia and autism put a heavy load on today’s societies, creating a steady call for revealing underlying disease mechanisms and the development of effective treatments. The etiology of major psychiatric illnesses is complex involving gene by environment susceptibility...... factors. Hence, a deeper understanding is needed of how cortical neurodevelopmental deficiencies can arise from such gene-environment interactions. The convergence of genetic and environmental risk factors is a recent field of research. It is now clear that disease, infection and stress factors may...... and antipsychotics mediate their effects on hippocampal neurodevelopment through deregulation of the Zbtb20 gene. A short presentation of the status of this work will shown....

  18. UCP2 and UCP3 variants and gene-environment interaction associated with prediabetes and T2DM in a rural population: a case control study in China.

    Science.gov (United States)

    Su, Meifang; Chen, Xiaoying; Chen, Yue; Wang, Congyun; Li, Songtao; Ying, Xuhua; Xiao, Tian; Wang, Na; Jiang, Qingwu; Fu, Chaowei

    2018-03-12

    There are disparities for the association between uncoupling proteins (UCP) and type 2 diabetes (T2DM). The study was to examine the associations of genetic variants of UCP2 and UCP3 with prediabetes and T2DM in a rural Chinese population. A population-based case-control study of 397 adults with T2DM, 394 with prediabetes and 409 with normal glucose tolerance (NGT) was carried out in 2014 in a rural community in eastern China. Three groups were identified through a community survey and the prediabetes and NGT groups were frequently matched by age and gender with the T2DM group and they were not relatives of T2DM subjects. With r 2  ≥ 0.8 and minor allele frequency (MAF) ≥0.05 for tag single nucleotide polymorphisms (SNPs) with potential function, three (rs660339, rs45560234 and rs643064) and six (rs7930460, rs15763, rs647126, rs1800849, rs3781907 and rs1685356) SNPs were selected respectively for UCP2 and UCP3 and genotyped in real time using the MassARRAY system (Sequenom; USA). The haplotypes, gene-environmental interaction and association between genetic variants of UCP2 and UCP3 and prediabetes or T2DM were explored. There were no significant differences in age and sex among three study groups. After the adjustment for possible covariates, the A allele of rs1800849 in UCP3 was significantly associated with prediabetes (aOR AA vs GG  = 1.68, 95% CI: 1.02-2.78), and the association was also significant under the recessive model (aOR AA vs GA + GG  = 1.64, 95% CI: 1.02-2.66). Also, rs15763 was found to be marginally significantly associated with T2DM under dominant model (OR GA + AA vs GG  = 0.73, 95% CI: 0.52-1.03, P = 0.072). No haplotype was significantly associated with prediabetes or T2DM. Multiplicative interactions for rs660339-overweight on T2DM were observed. In addition, the AA genotype of rs660339 was associated with an increased risk of T2DM in overweight subjects (OR = 1.48, 95%CI: 0.87-2.52) but with a decreased

  19. Genome-Wide Gene-Environment Study Identifies Glutamate Receptor Gene GRIN2A as a Parkinson's Disease Modifier Gene via Interaction with Coffee

    Science.gov (United States)

    Hamza, Taye H.; Chen, Honglei; Hill-Burns, Erin M.; Rhodes, Shannon L.; Montimurro, Jennifer; Kay, Denise M.; Tenesa, Albert; Kusel, Victoria I.; Sheehan, Patricia; Eaaswarkhanth, Muthukrishnan; Yearout, Dora; Samii, Ali; Roberts, John W.; Agarwal, Pinky; Bordelon, Yvette; Park, Yikyung; Wang, Liyong; Gao, Jianjun; Vance, Jeffery M.; Kendler, Kenneth S.; Bacanu, Silviu-Alin; Scott, William K.; Ritz, Beate; Nutt, John; Factor, Stewart A.; Zabetian, Cyrus P.; Payami, Haydeh

    2011-01-01

    Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD). We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC), and we performed a genome-wide association and interaction study (GWAIS), testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal components. We then stratified subjects as heavy or light coffee-drinkers and performed genome-wide association study (GWAS) in each group. We replicated the most significant SNP. Finally, we imputed the NGRC dataset, increasing genomic coverage to examine the region of interest in detail. The primary analyses (GWAIS, GWAS, Replication) were performed using genotyped data. In GWAIS, the most significant signal came from rs4998386 and the neighboring SNPs in GRIN2A. GRIN2A encodes an NMDA-glutamate-receptor subunit and regulates excitatory neurotransmission in the brain. Achieving P2df = 10−6, GRIN2A surpassed all known PD susceptibility genes in significance in the GWAIS. In stratified GWAS, the GRIN2A signal was present in heavy coffee-drinkers (OR = 0.43; P = 6×10−7) but not in light coffee-drinkers. The a priori Replication hypothesis that “Among heavy coffee-drinkers, rs4998386_T carriers have lower PD risk than rs4998386_CC carriers” was confirmed: ORReplication = 0.59, PReplication = 10−3; ORPooled = 0.51, PPooled = 7×10−8. Compared to light coffee-drinkers with rs4998386_CC genotype, heavy coffee-drinkers with rs4998386_CC genotype had 18% lower risk (P = 3×10−3), whereas heavy coffee-drinkers with rs4998386_TC genotype had 59% lower risk (P = 6×10−13). Imputation revealed a block of SNPs that achieved P2dfcoffee-drinkers. This study is proof of concept that inclusion of environmental factors can help identify genes that

  20. Peer deviance, parental divorce, and genetic risk in the prediction of drug abuse in a nationwide Swedish sample: evidence of environment-environment and gene-environment interaction.

    Science.gov (United States)

    Kendler, Kenneth S; Ohlsson, Henrik; Sundquist, Kristina; Sundquist, Jan

    2014-04-01

    Peer deviance (PD) strongly predicts externalizing psychopathologic conditions but has not been previously assessable in population cohorts. We sought to develop such an index of PD and to clarify its effects on risk of drug abuse (DA). To examine how strongly PD increases the risk of DA and whether this community-level liability indicator interacts with key DA risk factors at the individual and family levels. Studies of future DA registration in 1,401,698 Swedish probands born from January 1, 1970, through December 31, 1985, and their adolescent peers in approximately 9200 small community areas. Peer deviance was defined as the proportion of individuals born within 5 years of the proband living in the same small community when the proband was 15 years old who eventually were registered for DA. Drug abuse recorded in medical, legal, or pharmacy registry records. Peer deviance was associated with future DA in the proband, with rates of DA in older and male peers more strongly predictive than in younger or female peers. The predictive power of PD was only slightly attenuated by adding measures of community deprivation, collective efficacy, or family socioeconomic status. Probands whose parents were divorced were more sensitive to the pathogenic effects of high PD environments. A robust positive interaction was also seen between genetic risk of DA (indexed by rates of DA in first-, second-, and third-degree relatives) and PD exposure. With sufficient data, PD can be measured in populations and strongly predicts DA. In a nationwide sample, risk factors at the level of the individual (genetic vulnerability), family (parental loss), and community (PD) contribute substantially to risk of DA. Individuals at elevated DA risk because of parental divorce or high genetic liability are more sensitive to the pathogenic effects of PD. Although the effect of our PD measure on DA liability cannot be explained by standard measures of community or family risk, we cannot, with

  1. Genome-wide gene-environment study identifies glutamate receptor gene GRIN2A as a Parkinson's disease modifier gene via interaction with coffee.

    Science.gov (United States)

    Hamza, Taye H; Chen, Honglei; Hill-Burns, Erin M; Rhodes, Shannon L; Montimurro, Jennifer; Kay, Denise M; Tenesa, Albert; Kusel, Victoria I; Sheehan, Patricia; Eaaswarkhanth, Muthukrishnan; Yearout, Dora; Samii, Ali; Roberts, John W; Agarwal, Pinky; Bordelon, Yvette; Park, Yikyung; Wang, Liyong; Gao, Jianjun; Vance, Jeffery M; Kendler, Kenneth S; Bacanu, Silviu-Alin; Scott, William K; Ritz, Beate; Nutt, John; Factor, Stewart A; Zabetian, Cyrus P; Payami, Haydeh

    2011-08-01

    Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD). We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC), and we performed a genome-wide association and interaction study (GWAIS), testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal components. We then stratified subjects as heavy or light coffee-drinkers and performed genome-wide association study (GWAS) in each group. We replicated the most significant SNP. Finally, we imputed the NGRC dataset, increasing genomic coverage to examine the region of interest in detail. The primary analyses (GWAIS, GWAS, Replication) were performed using genotyped data. In GWAIS, the most significant signal came from rs4998386 and the neighboring SNPs in GRIN2A. GRIN2A encodes an NMDA-glutamate-receptor subunit and regulates excitatory neurotransmission in the brain. Achieving P(2df) = 10(-6), GRIN2A surpassed all known PD susceptibility genes in significance in the GWAIS. In stratified GWAS, the GRIN2A signal was present in heavy coffee-drinkers (OR = 0.43; P = 6×10(-7)) but not in light coffee-drinkers. The a priori Replication hypothesis that "Among heavy coffee-drinkers, rs4998386_T carriers have lower PD risk than rs4998386_CC carriers" was confirmed: OR(Replication) = 0.59, P(Replication) = 10(-3); OR(Pooled) = 0.51, P(Pooled) = 7×10(-8). Compared to light coffee-drinkers with rs4998386_CC genotype, heavy coffee-drinkers with rs4998386_CC genotype had 18% lower risk (P = 3×10(-3)), whereas heavy coffee-drinkers with rs4998386_TC genotype had 59% lower risk (P = 6×10(-13)). Imputation revealed a block of SNPs that achieved P(2df)coffee-drinkers. This study is proof of concept that inclusion of environmental factors can help identify

  2. Genome-wide gene-environment study identifies glutamate receptor gene GRIN2A as a Parkinson's disease modifier gene via interaction with coffee.

    Directory of Open Access Journals (Sweden)

    Taye H Hamza

    2011-08-01

    Full Text Available Our aim was to identify genes that influence the inverse association of coffee with the risk of developing Parkinson's disease (PD. We used genome-wide genotype data and lifetime caffeinated-coffee-consumption data on 1,458 persons with PD and 931 without PD from the NeuroGenetics Research Consortium (NGRC, and we performed a genome-wide association and interaction study (GWAIS, testing each SNP's main-effect plus its interaction with coffee, adjusting for sex, age, and two principal components. We then stratified subjects as heavy or light coffee-drinkers and performed genome-wide association study (GWAS in each group. We replicated the most significant SNP. Finally, we imputed the NGRC dataset, increasing genomic coverage to examine the region of interest in detail. The primary analyses (GWAIS, GWAS, Replication were performed using genotyped data. In GWAIS, the most significant signal came from rs4998386 and the neighboring SNPs in GRIN2A. GRIN2A encodes an NMDA-glutamate-receptor subunit and regulates excitatory neurotransmission in the brain. Achieving P(2df = 10(-6, GRIN2A surpassed all known PD susceptibility genes in significance in the GWAIS. In stratified GWAS, the GRIN2A signal was present in heavy coffee-drinkers (OR = 0.43; P = 6×10(-7 but not in light coffee-drinkers. The a priori Replication hypothesis that "Among heavy coffee-drinkers, rs4998386_T carriers have lower PD risk than rs4998386_CC carriers" was confirmed: OR(Replication = 0.59, P(Replication = 10(-3; OR(Pooled = 0.51, P(Pooled = 7×10(-8. Compared to light coffee-drinkers with rs4998386_CC genotype, heavy coffee-drinkers with rs4998386_CC genotype had 18% lower risk (P = 3×10(-3, whereas heavy coffee-drinkers with rs4998386_TC genotype had 59% lower risk (P = 6×10(-13. Imputation revealed a block of SNPs that achieved P(2df<5×10(-8 in GWAIS, and OR = 0.41, P = 3×10(-8 in heavy coffee-drinkers. This study is proof of

  3. Nutrigenomics, the Microbiome, and Gene-Environment Interactions: New Directions in Cardiovascular Disease Research, Prevention, and Treatment: A Scientific Statement From the American Heart Association.

    Science.gov (United States)

    Ferguson, Jane F; Allayee, Hooman; Gerszten, Robert E; Ideraabdullah, Folami; Kris-Etherton, Penny M; Ordovás, José M; Rimm, Eric B; Wang, Thomas J; Bennett, Brian J

    2016-06-01

    Cardiometabolic diseases are the leading cause of death worldwide and are strongly linked to both genetic and nutritional factors. The field of nutrigenomics encompasses multiple approaches aimed at understanding the effects of diet on health or disease development, including nutrigenetic studies investigating the relationship between genetic variants and diet in modulating cardiometabolic risk, as well as the effects of dietary components on multiple "omic" measures, including transcriptomics, metabolomics, proteomics, lipidomics, epigenetic modifications, and the microbiome. Here, we describe the current state of the field of nutrigenomics with respect to cardiometabolic disease research and outline a direction for the integration of multiple omics techniques in future nutrigenomic studies aimed at understanding mechanisms and developing new therapeutic options for cardiometabolic disease treatment and prevention. © 2016 American Heart Association, Inc.

  4. Gene-environment interaction in atopic diseases

    DEFF Research Database (Denmark)

    Kahr, Niklas; Naeser, Vibeke; Stensballe, Lone Graff

    2015-01-01

    INTRODUCTION: The development of atopic diseases early in life suggests an important role of perinatal risk factors. OBJECTIVES: To study whether early-life exposures modify the genetic influence on atopic diseases in a twin population. METHODS: Questionnaire data on atopic diseases from 850....... Significant predictors of atopic diseases were identified with logistic regression and subsequently tested for genetic effect modification using variance components analysis. RESULTS: After multivariable adjustment, prematurity (gestational age below 32 weeks) [odds ratio (OR) = 1.93, confidence interval (CI...... stratified by exposure status showed no significant change in the heritability of asthma according to the identified risk factors. CONCLUSION: In this population-based study of children, there was no evidence of genetic effect modification of atopic diseases by several identified early-life risk factors...

  5. Gene-Environment Interaction in Parkinson's Disease

    DEFF Research Database (Denmark)

    Chuang, Yu-Hsuan; Lill, Christina M; Lee, Pei-Chen

    2016-01-01

    BACKGROUND AND PURPOSE: Drinking caffeinated coffee has been reported to provide protection against Parkinson's disease (PD). Caffeine is an adenosine A2A receptor (encoded by the gene ADORA2A) antagonist that increases dopaminergic neurotransmission and Cytochrome P450 1A2 (gene: CYP1A2...

  6. Influence on serum asymmetric dimethylarginine (ADMA) concentrations of human paraoxonase 1 polymorphism (Q192R) and exposure to polycyclic aromatic hydrocarbons (PAHs) in Mexican women, a gene-environment interaction.

    Science.gov (United States)

    Ochoa-Martínez, Ángeles C; Ruíz-Vera, Tania; Almendarez-Reyna, Claudia I; Orta-García, Sandra T; Pérez-Maldonado, Iván N

    2017-11-01

    It has been demonstrated that Cardiovascular Diseases (CVD) are a consequence of the combination of genetic and environmental factors and/or the interaction between them. Therefore, the aim of this study was to evaluate the impact of polycyclic aromatic hydrocarbon (PAHs) exposure and PON1 Q192R polymorphism (genetic susceptibility) on serum asymmetric dimethylarginine (ADMA) levels in Mexican women (n = 206). Urinary 1-hydroxypyrene concentrations (1-OHP; exposure biomarker for PAHs) were quantified using a high-performance liquid chromatography technique, PON1 Q192R polymorphism was genotyped using TaqMan probes and serum ADMA concentrations were evaluated using a commercially available ELISA kit. Urinary 1-OHP levels detected in this study ranged from 0.07 to 9.37 μmol/mol of creatinine (0.13-18.0 μg/g of creatinine). Regarding allele frequency (PON1 Q192R polymorphism), the 192Q-allele frequency was 0.43 and for the 192R-allele it was 0.57. In relation to serum ADMA levels, the levels ranged from 0.06 to 1.46 μmol/L. Moreover, multiple linear regression analysis was performed and associations between urinary 1-OHP levels (β = 0.05, p = 0.002), PON1 Q192R polymorphism (β = 0.04, p = 0.003) and serum ADMA concentrations were found. Besides, an interaction (gene-environment interaction) of both independent variables (1-OHP and PON1 polymorphism) on serum ADMA levels was found (β = 0.04, p = 0.02) in the constructed multiple linear model. Therefore, according to the significance of this research, it is necessary to execute health programs to reduce cardiovascular risk in the assessed population. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Gene-Environment Interplay between Number of Friends and Prosocial Leadership Behavior in Children

    Science.gov (United States)

    Rivizzigno, Alessandra S.; Brendgen, Mara; Feng, Bei; Vitaro, Frank; Dionne, Ginette; Tremblay, Richard E.; Boivin, Michel

    2014-01-01

    Enriched environments may moderate the effect of genetic factors on prosocial leadership (gene-environment interaction, G × E). However, positive environmental experiences may also themselves be influenced by a genetic disposition for prosocial leadership (gene-environment correlation, rGE). Relating these processes to friendships, the present…

  8. [Schizophrenia: genes, environment and neurodevelopment].

    Science.gov (United States)

    Do, K Q

    2013-09-18

    Psychoses are complex diseases resulting from the interaction between genetic vulnerability factors and various environmental risk factors during the brain development and leading to the emergence of the clinical phenotype at the end of adolescence. Among the mechanisms involved, a redox imbalance plays an important role, inducing oxidative stress damaging to developing neurons. As a consequence, the excitatory/inhibitory balance in cortex and the pathways connecting brain areas are both impaired. Childhood and adolescence appear as critical periods of vulnerability for deleterious environmental insults. Antioxidants, applied during the environmental impacts, should allow preventing these impairments as well as their clinical consequences.

  9. Gene-environment interplay in the etiology of psychosis.

    Science.gov (United States)

    Zwicker, Alyson; Denovan-Wright, Eileen M; Uher, Rudolf

    2018-01-15

    Schizophrenia and other types of psychosis incur suffering, high health care costs and loss of human potential, due to the combination of early onset and poor response to treatment. Our ability to prevent or cure psychosis depends on knowledge of causal mechanisms. Molecular genetic studies show that thousands of common and rare variants contribute to the genetic risk for psychosis. Epidemiological studies have identified many environmental factors associated with increased risk of psychosis. However, no single genetic or environmental factor is sufficient to cause psychosis on its own. The risk of developing psychosis increases with the accumulation of many genetic risk variants and exposures to multiple adverse environmental factors. Additionally, the impact of environmental exposures likely depends on genetic factors, through gene-environment interactions. Only a few specific gene-environment combinations that lead to increased risk of psychosis have been identified to date. An example of replicable gene-environment interaction is a common polymorphism in the AKT1 gene that makes its carriers sensitive to developing psychosis with regular cannabis use. A synthesis of results from twin studies, molecular genetics, and epidemiological research outlines the many genetic and environmental factors contributing to psychosis. The interplay between these factors needs to be considered to draw a complete picture of etiology. To reach a more complete explanation of psychosis that can inform preventive strategies, future research should focus on longitudinal assessments of multiple environmental exposures within large, genotyped cohorts beginning early in life.

  10. Confluence of genes, environment, development, and behavior in a post Genome-Wide Association Study world.

    Science.gov (United States)

    Vrieze, Scott I; Iacono, William G; McGue, Matt

    2012-11-01

    This article serves to outline a research paradigm to investigate main effects and interactions of genes, environment, and development on behavior and psychiatric illness. We provide a historical context for candidate gene studies and genome-wide association studies, including benefits, limitations, and expected payoffs. Using substance use and abuse as our driving example, we then turn to the importance of etiological psychological theory in guiding genetic, environmental, and developmental research, as well as the utility of refined phenotypic measures, such as endophenotypes, in the pursuit of etiological understanding and focused tests of genetic and environmental associations. Phenotypic measurement has received considerable attention in the history of psychology and is informed by psychometrics, whereas the environment remains relatively poorly measured and is often confounded with genetic effects (i.e., gene-environment correlation). Genetically informed designs, which are no longer limited to twin and adoption studies thanks to ever-cheaper genotyping, are required to understand environmental influences. Finally, we outline the vast amount of individual difference in structural genomic variation, most of which remains to be leveraged in genetic association tests. Although the genetic data can be massive and burdensome (tens of millions of variants per person), we argue that improved understanding of genomic structure and function will provide investigators with new tools to test specific a priori hypotheses derived from etiological psychological theory, much like current candidate gene research but with less confusion and more payoff than candidate gene research has to date.

  11. Genotypes Do Not Confer Risk For Delinquency ut Rather Alter Susceptibility to Positive and Negative Environmental Factors: Gene-Environment Interactions of BDNF Val66Met, 5-HTTLPR, and MAOA-uVNTR

    Science.gov (United States)

    Comasco, Erika; Hodgins, Sheilagh; Oreland, Lars; Åslund, Cecilia

    2015-01-01

    Background: Previous evidence of gene-by-environment interactions associated with emotional and behavioral disorders is contradictory. Differences in findings may result from variation in valence and dose of the environmental factor, and/or failure to take account of gene-by-gene interactions. The present study investigated interactions between the brain-derived neurotrophic factor gene (BDNF Val66Met), the serotonin transporter gene-linked polymorphic region (5-HTTLPR), the monoamine oxidase A (MAOA-uVNTR) polymorphisms, family conflict, sexual abuse, the quality of the child-parent relationship, and teenage delinquency. Methods: In 2006, as part of the Survey of Adolescent Life in Västmanland, Sweden, 1 337 high-school students, aged 17–18 years, anonymously completed questionnaires and provided saliva samples for DNA analyses. Results: Teenage delinquency was associated with two-, three-, and four-way interactions of each of the genotypes and the three environmental factors. Significant four-way interactions were found for BDNF Val66Met × 5-HTTLPR×MAOA-uVNTR × family conflicts and for BDNF Val66Met × 5-HTTLPR×MAOA-uVNTR × sexual abuse. Further, the two genotype combinations that differed the most in expression levels (BDNF Val66Met Val, 5-HTTLPR LL, MAOA-uVNTR LL [girls] and L [boys] vs BDNF Val66Met Val/Met, 5-HTTLPR S/LS, MAOA-uVNTR S/SS/LS) in interaction with family conflict and sexual abuse were associated with the highest delinquency scores. The genetic variants previously shown to confer vulnerability for delinquency (BDNF Val66Met Val/Met × 5-HTTLPR S × MAOA-uVNTR S) were associated with the lowest delinquency scores in interaction with a positive child-parent relationship. Conclusions: Functional variants of the MAOA-uVNTR, 5-HTTLPR, and BDNF Val66Met, either alone or in interaction with each other, may be best conceptualized as modifying sensitivity to environmental factors that confer either risk or protection for teenage delinquency. PMID

  12. Interactive investigations into planetary interiors

    Science.gov (United States)

    Rose, I.

    2015-12-01

    Many processes in Earth science are difficult to observe or visualize due to the large timescales and lengthscales over which they operate. The dynamics of planetary mantles are particularly challenging as we cannot even look at the rocks involved. As a result, much teaching material on mantle dynamics relies on static images and cartoons, many of which are decades old. Recent improvements in computing power and technology (largely driven by game and web development) have allowed for advances in real-time physics simulations and visualizations, but these have been slow to affect Earth science education.Here I demonstrate a teaching tool for mantle convection and seismology which solves the equations for conservation of mass, momentum, and energy in real time, allowing users make changes to the simulation and immediately see the effects. The user can ask and answer questions about what happens when they add heat in one place, or take it away from another place, or increase the temperature at the base of the mantle. They can also pause the simulation, and while it is paused, create and visualize seismic waves traveling through the mantle. These allow for investigations into and discussions about plate tectonics, earthquakes, hot spot volcanism, and planetary cooling.The simulation is rendered to the screen using OpenGL, and is cross-platform. It can be run as a native application for maximum performance, but it can also be embedded in a web browser for easy deployment and portability.

  13. Interacting With Robots to Investigate the Bases of Social Interaction.

    Science.gov (United States)

    Sciutti, Alessandra; Sandini, Giulio

    2017-12-01

    Humans show a great natural ability at interacting with each other. Such efficiency in joint actions depends on a synergy between planned collaboration and emergent coordination, a subconscious mechanism based on a tight link between action execution and perception. This link supports phenomena as mutual adaptation, synchronization, and anticipation, which cut drastically the delays in the interaction and the need of complex verbal instructions and result in the establishment of joint intentions, the backbone of social interaction. From a neurophysiological perspective, this is possible, because the same neural system supporting action execution is responsible of the understanding and the anticipation of the observed action of others. Defining which human motion features allow for such emergent coordination with another agent would be crucial to establish more natural and efficient interaction paradigms with artificial devices, ranging from assistive and rehabilitative technology to companion robots. However, investigating the behavioral and neural mechanisms supporting natural interaction poses substantial problems. In particular, the unconscious processes at the basis of emergent coordination (e.g., unintentional movements or gazing) are very difficult-if not impossible-to restrain or control in a quantitative way for a human agent. Moreover, during an interaction, participants influence each other continuously in a complex way, resulting in behaviors that go beyond experimental control. In this paper, we propose robotics technology as a potential solution to this methodological problem. Robots indeed can establish an interaction with a human partner, contingently reacting to his actions without losing the controllability of the experiment or the naturalness of the interactive scenario. A robot could represent an "interactive probe" to assess the sensory and motor mechanisms underlying human-human interaction. We discuss this proposal with examples from our

  14. When chocolate seeking becomes compulsion: gene-environment interplay.

    Directory of Open Access Journals (Sweden)

    Enrico Patrono

    Full Text Available Eating disorders appear to be caused by a complex interaction between environmental and genetic factors, and compulsive eating in response to adverse circumstances characterizes many eating disorders.We compared compulsion-like eating in the form of conditioned suppression of palatable food-seeking in adverse situations in stressed C57BL/6J and DBA/2J mice, two well-characterized inbred strains, to determine the influence of gene-environment interplay on this behavioral phenotype. Moreover, we tested the hypothesis that low accumbal D2 receptor (R availability is a genetic risk factor of food compulsion-like behavior and that environmental conditions that induce compulsive eating alter D2R expression in the striatum. To this end, we measured D1R and D2R expression in the striatum and D1R, D2R and α1R levels in the medial prefrontal cortex, respectively, by western blot.Exposure to environmental conditions induces compulsion-like eating behavior, depending on genetic background. This behavioral pattern is linked to decreased availability of accumbal D2R. Moreover, exposure to certain environmental conditions upregulates D2R and downregulates α1R in the striatum and medial prefrontal cortex, respectively, of compulsive animals. These findings confirm the function of gene-environment interplay in the manifestation of compulsive eating and support the hypothesis that low accumbal D2R availability is a "constitutive" genetic risk factor for compulsion-like eating behavior. Finally, D2R upregulation and α1R downregulation in the striatum and medial prefrontal cortex, respectively, are potential neuroadaptive responses that parallel the shift from motivated to compulsive eating.

  15. Experimental investigation on particle-wall interactions

    International Nuclear Information System (INIS)

    Zeisel, H.; Dorfner, V.

    1988-01-01

    There is still a lack in the knowledge about many physical processes in two-phase flows and therefore their mathematical description for the modelling of two-phase flows by computer simulations still needs some improvement. One required information is the physical procedure of the momentum transfer between the phases themselves, such as particle-particle or particle-fluid interactions, and between the phases and the flow boundaries, such as particle-wall or fluid-wall interactions. The interaction between the two phases can be either a 'long-range' interference or a direct contact between both. For the particle-fluid two-phase flow system the interaction can be devided in particle-fluid, particle-particle and particle-boundary interactions. In this investigation the attention is drawn to the special case of a particle-wall interaction and its 'long-range' interference effect between the wall and a small particle which approaches the wall in normal direction. (orig./GL)

  16. Investigation of Dendrimer-Membrane Interactions

    Science.gov (United States)

    Mecke, Almut; Hessler, Jessica; Lee, Inhan; Banaszak Holl, Mark; Orr, Bradford; Patri, Anil K.; Baker, J. R.

    2003-03-01

    Modified Polyamidoamine (PAMAM) dendrimers show great promise as targeted drug transport agents. Current research efforts point to the possibility of dramatic improvements to conventional chemotherapy by selectively delivering a therapeutic to antigen bearing tumor cells. In order to better understand the uptake mechanism of such devices into cells we are investigating dendrimer-surface adsorption and dendrimer-membrane interactions using atomic force microscopy, light scattering and computer simulations. Model systems consisting of supported DMPC lipid bilayers have shown interesting results suggesting the shape and architecture of nano-devices play an important role for their biologic activity. We are also investigating the effect of targeted drug vehicles on cells in vitro.

  17. The genetics of human longevity: an intricacy of genes, environment, culture and microbiome.

    Science.gov (United States)

    Dato, Serena; Rose, Giuseppina; Crocco, Paolina; Monti, Daniela; Garagnani, Paolo; Franceschi, Claudio; Passarino, Giuseppe

    2017-07-01

    Approximately one-quarter of the variation in lifespan in developed countries can be attributed to genetic factors. However, even large population based studies investigating genetic influence on human lifespan have been disappointing, identifying only a few genes accounting for genetic susceptibility to longevity. Some environmental and lifestyle determinants associated with longevity have been identified, which interplay with genetic factors in an intricate way. The study of gene-environment and gene-gene interactions can significantly improve our chance to disentangle this complex scenario. In this review, we first describe the most recent approaches for genetic studies of longevity, from those enriched with health parameters and frailty measures to pathway-based and SNP-SNP interaction analyses. Then, we go deeper into the concept of "environmental influences" in human aging and longevity, focusing on the contribution of life style changes, social and cultural influences, as important determinants of survival differences among individuals in a population. Finally, we discuss the contribution of the microbiome in human longevity, as an example of complex interaction between organism and environment. In conclusion, evidences collected from the latest studies on human longevity provide a support for the collection of life-long genetic and environmental/lifestyle variables with beneficial or detrimental effects on health, to improve our understanding of the determinants of human lifespan. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Microglia Polarization, Gene-Environment Interactions and Wnt/β-Catenin Signaling: Emerging Roles of Glia-Neuron and Glia-Stem/Neuroprogenitor Crosstalk for Dopaminergic Neurorestoration in Aged Parkinsonian Brain

    Directory of Open Access Journals (Sweden)

    Francesca L'Episcopo

    2018-02-01

    recent findings unveiling major microglial inflammatory and oxidative stress pathways converging in the regulation of Wnt/β-catenin signaling, and reciprocally, the ability of Wnt signaling pathways to modulate microglial activation in PD. Unraveling the key factors and conditons promoting the switch of the proinflammatory M1 microglia status into a neuroprotective and regenerative M2 phenotype will have important consequences for neuroimmune interactions and neuronal outcome under inflammatory and/or neurodegenerative conditions.

  19. Gene-environment interaction and biological monitoring of occupational exposures

    International Nuclear Information System (INIS)

    Hirvonen, Ari

    2005-01-01

    Biological monitoring methods and biological limit values applied in occupational and environmental medicine have been traditionally developed on the assumption that individuals do not differ significantly in their biotransformation capacities. It has become clear, however, that this is not the case, but wide inter-individual differences exist in the metabolism of chemicals. Integration of the data on individual metabolic capacity in biological monitoring studies is therefore anticipated to represent a significant refinement of the currently used methods. We have recently conducted several biological monitoring studies on occupationally exposed subjects, which have included the determination of the workers' genotypes for the metabolic genes of potential importance for a given chemical exposure. The exposure levels have been measured by urine metabolites, adducts in blood macromolecules, and cytogenetic alterations in lymphocytes. Our studies indicate that genetic polymorphisms in metabolic genes may indeed be important modifiers of individual biological monitoring results of, e.g., carbon disulphide and styrene. The information is anticipated to be useful in insuring that the workplace is safe for everyone, including the most sensitive individuals. This knowledge could also be useful to occupational physicians, industrial hygienists, and regulatory bodies in charge of defining acceptable exposure limits for environmental and/or occupational pollutants

  20. Gene-environment interaction and male reproductive function

    DEFF Research Database (Denmark)

    Axelsson, Jonatan; Bonde, Jens Peter; Giwercman, Yvonne L

    2010-01-01

    As genetic factors can hardly explain the changes taking place during short time spans, environmental and lifestyle-related factors have been suggested as the causes of time-related deterioration of male reproductive function. However, considering the strong heterogeneity of male fecundity between...... and within populations, genetic variants might be important determinants of the individual susceptibility to the adverse effects of environment or lifestyle. Although the possible mechanisms of such interplay in relation to the reproductive system are largely unknown, some recent studies have indicated...... that specific genotypes may confer a larger risk of male reproductive disorders following certain exposures. This paper presents a critical review of animal and human evidence on how genes may modify environmental effects on male reproductive function. Some examples have been found that support this mechanism...

  1. Investigation of nanodiamonds interactions in canine blood

    Science.gov (United States)

    WÄ sowicz, Michał; Marek, Kulka; Cićkiewicz, Maciej; Cymerman, Magdalena

    2017-02-01

    The whole blood contains red cells, white cells, and platelets suspended in plasma. In the following study we investigated an impact of nanodiamond particles on blood elements over various periods of time.The material used in the study consisted of samples taken from ten healthy canines (Canis lupus f. domestica) of various age, different blood types and both sexes. The markings were conducted by adding to the blood unmodified diamonds (SND), modified O2 (SO2) suspended in 0,9% NaCl. The blood was put under an impact of two diamond concentrations: 20μl and 100μl. The amount of abnormal cells increased with time. The percentage of echinocytes as a result of interaction with nanodiamonds in various time periods for individual specimens was scarce. In the examined microscopic image a summary was made for 100 white blood cells. Following cells were included in said group: band neutrophils, segmented neutrophils, eosinophils, basophils, lymphocytes, monocytes, lymphocytes with granulates, stimulated lymphocytes, lymphocytes with vacuoles, metamielocytes and smudge cells. The impact of the three diamond types had no clinical importance on red blood cells. After the diamonds mixed with white blood cells, atypical cells came into being, in the range of agranulocytes in stimulated form or with granulates and/or vacuoles. It is supposed that as a result of longlasting exposure a stimulation and vacuolisation takes place, because of the function of the cells.

  2. Experimental investigation of shock wave - bubble interaction

    Energy Technology Data Exchange (ETDEWEB)

    Alizadeh, Mohsen

    2010-04-09

    In this work, the dynamics of laser-generated single cavitation bubbles exposed to lithotripter shock waves has been investigated experimentally. The energy of the impinging shock wave is varied in several steps. High-speed photography and pressure field measurements simultaneously with image acquisition provide the possibility of capturing the fast bubble dynamics under the effect of the shock wave impact. The pressure measurement is performed using a fiber optic probe hydrophone (FOPH) which operates based on optical diagnostics of the shock wave propagating medium. After a short introduction in chapter 1 an overview of the previous studies in chapter 2 is presented. The reported literatures include theoretical and experimental investigations of several configurations of physical problems in the field of bubble dynamics. In chapter 3 a theoretical description of propagation of a shock wave in a liquid like water has been discussed. Different kinds of reflection of a shock wave at an interface are taken into account. Undisturbed bubble dynamics as well as interaction between a planar shock wave and an initially spherical bubble are explored theoretically. Some physical parameters which are important in this issue such as the velocity of the shock-induced liquid jet, Kelvin impulse and kinetic energy are explained. The shock waves are generated in a water filled container by a focusing piezoelectric generator. The shock wave profile has a positive part with pulse duration of ∼1 μs followed by a longer tension tail (i.e. ∼3 μs). In chapter 4 high-speed images depict the propagation of a shock wave in the water filled tank. The maximum pressure is also derived for different intensity levels of the shock wave generator. The measurement is performed in the free field (i.e. in the absence of laser-generated single bubbles). In chapter 5 the interaction between lithotripter shock waves and laserinduced single cavitation bubbles is investigated experimentally. An

  3. Gene-Environment Interplay, Family Relationships, and Child Adjustment

    Science.gov (United States)

    Horwitz, Briana N.; Neiderhiser, Jenae M.

    2011-01-01

    This paper reviews behavioral genetic research from the past decade that has moved beyond simply studying the independent influences of genes and environments. The studies considered in this review have instead focused on understanding gene-environment interplay, including genotype-environment correlation (rGE) and genotype x environment…

  4. Investigation on particle-solid interactions

    International Nuclear Information System (INIS)

    Yano, Syukuro

    1988-08-01

    Basic processes in plasma-material interactions have been surveyed and reviewed. Problems concerned with carbon materials, which have been progressively used for the first wall and limiters in Tokamaks, are mainly discussed. Recent usage of carbon materials, basic properties and characteristics of carbon/graphite materials, desorption of gasses are described. As to the interactions of incident hydrogen isotope particles with graphite surface, data of trapping, depth profile, reemission, isotope exchange, and diffusion are reviewed and discussed. (author)

  5. Fluid-structure interaction investigations for pipelines

    International Nuclear Information System (INIS)

    Altstadt, E.; Carl, H.; Weiss, R.

    2003-12-01

    In existing Nuclear Power Plants water hammers can occur in case of an inflow of sub-cooled water into pipes or other parts of the equipment, which are filled with steam or steam-water mixture. They also may appear as the consequence of fast valve closing or opening actions or of breaks in pipelines, with single phase or two-phase flow. In the latter case, shock waves in two-phase flow must be expected. In all cases, strong dynamic stresses are induced in the wall of the equipment. Further, the change of the momentum of the liquid motion and the deformation of the component due to the dynamic stresses generate high loads on the support structures of the component, in which the water hammer respectively the shock wave occurs. The influence of the fluid-structure interaction on the magnitude of the loads on pipe walls and support structures is not yet completely understood. In case of a dynamic load caused by a pressure wave, the stresses in pipe walls, especially in bends, are different from the static case. The propagating pressure wave may cause additional non-symmetric deformations which increase the equivalent stresses in comparison to the symmetric load created by a static inner pressure. On the other hand, fluid-structure interaction causes the structure to deform, which leads to a decrease of the resulting stresses. The lack of experimental data obtained at well defined geometric boundary conditions is a significant obstacle for the validation of codes which consider fluid-structure interaction. Furthermore, up to now the feedback from structural deformations to the fluid mechanics has not been fully implemented in existing calculation software codes. Therefore, at FZR a cold water hammer test facility (CWHTF) was designed and built up. (orig.)

  6. Investigations of interactions mediated by neutral currents

    International Nuclear Information System (INIS)

    Witek, M.

    2007-03-01

    The report is devoted to four-fermion interactions mediated by the neutral currents. The results from the second phase of LEP are presented, when the production of two massive bosons was possible with the increased energy of the e + e - collisions. It enabled for a direct test of nonabelian structure of the electroweak theory. The results concern the four-fermion production of the pairs of the ZZ bosons, single Z and Zγ * production as well as search for anomalous gauge bosons couplings. The large part of the report is devoted to experimental techniques, physics analyses and discussion of results. (author)

  7. Investigation of beryllium/steam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chekhonadskikh, A.M.; Vurim, A.D.; Vasilyev, Yu.S.; Pivovarov, O.S. [Inst. of Atomic Energy National Nuclear Center of the Republic of Kazakstan Semipalatinsk (Kazakhstan); Shestakov, V.P.; Tazhibayeva, I.L.

    1998-01-01

    In this report program on investigations of beryllium emissivity and transient processes on overheated beryllium surface attacked by water steam to be carried out in IAE NNC RK within Task S81 TT 2096-07-16 FR. The experimental facility design is elaborated in this Report. (author)

  8. Investigation of molybdenum pentachloride interaction with chlorine

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Vovkotrub, Eh.G.; Strekalovskij, V.N.

    1993-01-01

    In Raman spectra of molybdenum pentachloride solutions in liquid chlorine lines were recorded in case of 397, 312, 410, 217 and 180 cm - 1 vibrations of ν 1 (A 1 '), ν 2 (A 1 '), ν 5 (E'), ν 6 (E') and ν 8 (E'') monomer (symmetry D 3h ) molecules of MoCl 5 . Interaction of molten molybdenum pentachloride with chlorine at increased (up to 6 MPa) pressures of Cl 2 was studied. In Raman spectra of its vapour distillation in liquid chlorine alongside with MoCl 5 lines appearance of new lines at 363 and 272 cm -1 , similar in their frequency to the ones calculated for the vibrations ν 1 (A 1g ) and ν 2 (E g ) of MoCl 6 molecules (symmetry O h ), was observed

  9. Proceedings of 4 conference on hyperfine interaction spectroscopic investigations

    International Nuclear Information System (INIS)

    Shpinel', V.S.

    1992-01-01

    Results of theoretical and experimental investigations on nuclear-spectroscopy of hyperfine interactions are presented. Possibility of the data use for technological and materials sceince problems is demonstrated

  10. Investigation of the ion beryllium surface interaction

    International Nuclear Information System (INIS)

    Guseva, M.I.; Birukov, A.Yu.; Gureev, V.M.

    1995-01-01

    The self -sputtering yield of the Be was measured. The energy dependence of the Be self-sputtering yield agrees well with that calculated by W. Eckstein et. al. Below 770 K the self-sputtering yield is temperature independent; at T irr .> 870 K it increases sharply. Hot-pressed samples at 370 K were implanted with monoenergetic 5 keV hydrogen ions and with a stationary plasma (flux power ∼ 5 MW/m 2 ). The investigation of hydrogen behavior in beryllium shows that at low doses hydrogen is solved, but at doses ≥ 5x10 22 m -2 the bubbles and channels are formed. It results in hydrogen profile shift to the surface and decrease of its concentration. The sputtering results in further concentration decrease at doses > 10 25 m -2

  11. Differences and similarities in the serotonergic diathesis for suicide attempts and mood disorders: a 22-year longitudinal gene-environment study.

    Science.gov (United States)

    Brezo, J; Bureau, A; Mérette, C; Jomphe, V; Barker, E D; Vitaro, F; Hébert, M; Carbonneau, R; Tremblay, R E; Turecki, G

    2010-08-01

    To investigate similarities and differences in the serotonergic diathesis for mood disorders and suicide attempts, we conducted a study in a cohort followed longitudinally for 22 years. A total of 1255 members of this cohort, which is representative of the French-speaking population of Quebec, were investigated. Main outcome measures included (1) mood disorders (bipolar disorder and major depression) and suicide attempts by early adulthood; (2) odds ratios and probabilities associated with 143 single nucleotide polymorphisms in 11 serotonergic genes, acting directly or as moderators in gene-environment interactions with childhood sexual or childhood physical abuse (CPA), and in gene-gene interactions; (3) regression coefficients for putative endophenotypes for mood disorders (childhood anxiousness) and suicide attempts (childhood disruptiveness). Five genes showed significant adjusted effects (HTR2A, TPH1, HTR5A, SLC6A4 and HTR1A). Of these, HTR2A variation influenced both suicide attempts and mood disorders, although through different mechanisms. In suicide attempts, HTR2A variants (rs6561333, rs7997012 and rs1885884) were involved through interactions with histories of sexual and physical abuse whereas in mood disorders through one main effect (rs9316235). In terms of phenotype-specific contributions, TPH1 variation (rs10488683) was relevant only in the diathesis for suicide attempts. Three genes contributed exclusively to mood disorders, one through a main effect (HTR5A (rs1657268)) and two through gene-environment interactions with CPA (HTR1A (rs878567) and SLC6A4 (rs3794808)). Childhood anxiousness did not mediate the effects of HTR2A and HTR5A on mood disorders, nor did childhood disruptiveness mediate the effects of TPH1 on suicide attempts. Of the serotonergic genes implicated in mood disorders and suicidal behaviors, four exhibited phenotype-specific effects, suggesting that despite their high concordance and common genetic determinants, suicide attempts

  12. Gene-Environment Interplay between Parent-Child Relationship Problems and Externalizing Disorders in Adolescence and Young Adulthood

    Science.gov (United States)

    Samek, Diana R.; Hicks, Brian M.; Keyes, Margaret A.; Bailey, Jennifer; McGue, Matt; Iacono, William G.

    2014-01-01

    Background Previous studies have shown that genetic risk for externalizing (EXT) disorders is greater in the context of adverse family environments during adolescence, but it is unclear whether these effects are long-lasting. The current study evaluated developmental changes in gene-environment interplay in the concurrent and prospective associations between parent-child relationship problems and EXT at ages 18 and 25. Method The sample included 1,382 twin pairs (48% male) from the Minnesota Twin Family Study, participating in assessments at ages 18 (M = 17.8 years, SD = 0.69) and 25 (M = 25.0 years, SD = 0.90). Perceptions of parent-child relationship problems were assessed using questionnaires. Structured interviews were used to assess symptoms of adult antisocial behavior and nicotine, alcohol, and illicit drug dependence. Results We detected a gene-environment interaction at age 18, such that the genetic influence on EXT was greater in the context of more parent-child relationship problems. This moderation effect was not present at age 25, nor did parent-relationship problems at age 18 moderate genetic influence on EXT at age 25. Rather, common genetic influences accounted for this longitudinal association. Conclusions Gene-environment interaction evident in the relationship between adolescent parent-child relationship problems and EXT is both proximal and developmentally limited. Common genetic influence, rather than a gene-environment interaction, accounts for the long-term association between parent-child relationship problems at age 18 and EXT at age 25. These results are consistent with a relatively pervasive importance of gene-environmental correlation in the transition from late adolescence to young adulthood. PMID:25066478

  13. Investigating physics learning with layered student interaction networks

    DEFF Research Database (Denmark)

    Bruun, Jesper; Traxler, Adrienne

    Centrality in student interaction networks (SINs) can be linked to variables like grades [1], persistence [2], and participation [3]. Recent efforts in the field of network science have been done to investigate layered - or multiplex - networks as mathematical objects [4]. These networks can be e......, this study investigates how target entropy [5,1] and pagerank [6,7] are affected when we take time and modes of interaction into account. We present our preliminary models and results and outline our future work in this area....

  14. Diffraction stress analysis of thin films; investigating elastic grain interaction

    International Nuclear Information System (INIS)

    Kumar, A.

    2005-12-01

    This work is dedicated to the investigation of specimens exhibiting anisotropic microstructures (and thus macroscopic elastic anisotropy) and/or inhomogeneous microstructures, as met near surfaces and in textured materials. The following aspects are covered: (i) Analysis of specimens with direction-dependent (anisotropic) elastic grain-interaction. Elastic grain-interaction determines the distribution of stresses and strains over the (crystallographically) differently oriented grains of a mechanically stressed polycrystal and the mechanical and diffraction (X-ray) elastic constants (relating (diffraction) lattice strains to mechanical stresses). Grain interaction models that allow for anisotropic, direction-dependent grain interaction have been developed very recently. The notion 'direction-dependent' grain-interaction signifies that different grain-interaction constraints prevail along different directions in a specimen. Practical examples of direction-dependent grain interaction are the occurrence of surface anisotropy in thin films and the surface regions of bulk polycrystals and the occurrence of grain-shape (morphological) texture. In this work, for the first time, stress analyses of thin films have been performed on the basis of these newly developed grain-interaction models. It has also been demonstrated that the identification of the (dominant) source of direction-dependent grain interaction is possible. The results for the grain interaction have been discussed in the light of microstructural investigations of the specimens by microscopic techniques. (ii) Analysis of specimens with depth gradients: Diffraction stress analysis can be hindered if gradients of the stress state, the composition or the microstructure occur in the specimen under investigation, as the so-called information depth varies in the course of a traditional stress measurement: Ambiguous results are thus generally obtained. In this work, a strategy for stress measurements at fixed

  15. Investigating the interactions of the enantiomers of phenylglycine ...

    Indian Academy of Sciences (India)

    In this study, molecular dynamics simulation has been used to investigate the interactions of both chiral forms of ... about two orders of magnitude less than that in free water. Keywords. ... acids, peptides, drugs, and proteins with the surfaces of inorganic .... and energy parameters, qi and qj are the atomic point charges ...

  16. A preliminary investigation into genotype x environment interaction ...

    African Journals Online (AJOL)

    The purpose of the study was to investigate a possible genotype by environment interaction in first calf South African Holstein cows for both production and reproduction traits. Data from 100 975 cows on a total mixed ration (TMR) and 22 083 pasture based cows were used. These cows were the progeny of 4 391 sires and ...

  17. The role of gene-environment interplay in occupational and environmental diseases: current concepts and knowledge gaps.

    Science.gov (United States)

    Kwo, Elizabeth; Christiani, David

    2017-03-01

    The interplay between genetic susceptibilities and environmental exposures in the pathogenesis of a variety of diseases is an area of increased scientific, epidemiologic, and social interest. Given the variation in methodologies used in the field, this review aims to create a framework to help understand occupational exposures as they currently exist and provide a foundation for future inquiries into the biological mechanisms of the gene-environment interactions. Understanding of this complex interplay will be important in the context of occupational health, given the public health concerns surrounding a variety of occupational exposures. Studies found evidence that suggest genetics influence the progression of disease postberyllium exposure through genetically encoded major histocompatibility complex, class II, DP alpha 2 (HLA-DP2)-peptide complexes as it relates to T-helper cells. This was characterized at the molecular level by the accumulation of Be-responsive CD4 T cells in the lung, which resulted in posttranslational change in the HLA-DPB1 complex. These studies provide important evidence of gene-environment association, and many provide insights into specific pathogenic mechanisms. The following includes a review of the literature regarding gene-environment associations with a focus on pulmonary diseases as they relate to the workplace.

  18. Scanning probe and optical tweezer investigations of biomolecular interactions

    International Nuclear Information System (INIS)

    Rigby-Singleton, Shellie

    2002-01-01

    A complex array of intermolecular forces controls the interactions between and within biological molecules. The desire to empirically explore the fundamental forces has led to the development of several biophysical techniques. Of these, the atomic force microscope (AFM) and the optical tweezers have been employed throughout this thesis to monitor the intermolecular forces involved in biomolecular interactions. The AFM is a well-established force sensing technique capable of measuring biomolecular interactions at a single molecule level. However, its versatility has not been extrapolated to the investigation of a drug-enzyme complex. The energy landscape for the force induced dissociation of the DHFR-methotrexate complex was studied. Revealing an energy barrier to dissociation located ∼0.3 nm from the bound state. Unfortunately, the AFM has a limited range of accessible loading rates and in order to profile the complete energy landscape alternative force sensing instrumentation should be considered, for example the BFP and optical tweezers. Thus, this thesis outlines the development and construction an optical trap capable of measuring intermolecular forces between biomolecules at the single molecule level. To demonstrate the force sensing abilities of the optical set up, proof of principle measurements were performed which investigate the interactions between proteins and polymer surfaces subjected to varying degrees of argon plasma treatment. Complementary data was gained from measurements performed independently by the AFM. Changes in polymer resistance to proteins as a response to changes in polymer surface chemistry were detected utilising both AFM and optical tweezers measurements. Finally, the AFM and optical tweezers were employed as ultrasensitive biosensors. Single molecule investigations of the antibody-antigen interaction between the cardiac troponin I marker and its complementary antibody, reveals the impact therapeutic concentrations of heparin have

  19. Experimental investigations and modelling of sodium-concrete interaction

    International Nuclear Information System (INIS)

    Schultheiss, G.F.; Deeg, H.J.

    1990-01-01

    The use of sodium as a coolant in liquid metal fast breeder reactors, fusion reactors, and solar plants requires special consideration of its chemical reactivity and related safety problems in the case of sodium leckage. On contact between hot sodium and concrete an interaction takes place resulting in energy release and hydrogen generation, which may contribute to containment loading by pressurization in a hypothetical accident situation. For this reason, sodium-concrete interactions were investigated experimentally and theoretically. The experiments revealed important effects of quartzitic material within the concrete and of the sodium temperature on the interaction mechanisms, the energy release and the consequent hydrogen production. The numerical model shows good agreement with the experimental results. (orig.) [de

  20. Investigating the association between social interactions and personality states dynamics.

    Science.gov (United States)

    Gundogdu, Didem; Finnerty, Ailbhe N; Staiano, Jacopo; Teso, Stefano; Passerini, Andrea; Pianesi, Fabio; Lepri, Bruno

    2017-09-01

    The recent personality psychology literature has coined the name of personality states to refer to states having the same behavioural, affective and cognitive content (described by adjectives) as the corresponding trait, but for a shorter duration. The variability in personality states may be the reaction to specific characteristics of situations. The aim of our study is to investigate whether specific situational factors, that is, different configurations of face-to-face interactions, are predictors of variability of personality states in a work environment. The obtained results provide evidence that within-person variability in personality is associated with variation in face-to-face interactions. Interestingly, the effects differ by type and level of the personality states: adaptation effects for Agreeableness and Emotional Stability, whereby the personality states of an individual trigger similar states in other people interacting with them and complementarity effects for Openness to Experience, whereby the personality states of an individual trigger opposite states in other people interacting with them. Overall, these findings encourage further research to characterize face-to-face and social interactions in terms of their relevance to personality states.

  1. Gene-Environment Interplay in the Association between Pubertal Timing and Delinquency in Adolescent Girls

    Science.gov (United States)

    Harden, K. Paige; Mendle, Jane

    2014-01-01

    Early pubertal timing places girls at elevated risk for a breadth of negative outcomes, including involvement in delinquent behavior. While previous developmental research has emphasized the unique social challenges faced by early maturing girls, this relation is complicated by genetic influences for both delinquent behavior and pubertal timing, which are seldom controlled for in existing research. The current study uses genetically informed data on 924 female-female twin and sibling pairs drawn from the National Longitudinal Study of Adolescent Health to (1) disentangle biological versus environmental mechanisms for the effects of early pubertal timing and (2) test for gene-environment interactions. Results indicate that early pubertal timing influences girls’ delinquency through a complex interplay between biological risk and environmental experiences. Genes related to earlier age at menarche and higher perceived development significantly predict increased involvement in both non-violent and violent delinquency. Moreover, after accounting for this genetic association between pubertal timing and delinquency, the impact of non-shared environmental influences on delinquency are significantly moderated by pubertal timing, such that the non-shared environment is most important among early maturing girls. This interaction effect is particularly evident for non-violent delinquency. Overall, results suggest early maturing girls are vulnerable to an interaction between genetic and environmental risks for delinquent behavior. PMID:21668078

  2. Investigating the amplitude of interactive footstep sounds and soundscape reproduction

    DEFF Research Database (Denmark)

    Turchet, Luca; Serafin, Stefania

    2013-01-01

    In this paper, we study the perception of amplitude of soundscapes and interactively generated footstep sounds provided both through headphones and a surround sound system. In particular, we investigate whether there exists a value for the amplitude of soundscapes and footstep sounds which...... of soundscapes does not significantly affect the selected amplitude of footstep sounds. Similarly, the perception of the soundscapes amplitude is not significantly affected by the selected amplitude of footstep sounds....

  3. Investigation of migrant-polymer interaction in pharmaceutical packaging material using the linear interaction energy algorithm.

    Science.gov (United States)

    Feenstra, Peter; Brunsteiner, Michael; Khinast, Johannes

    2014-10-01

    The interaction between drug products and polymeric packaging materials is an important topic in the pharmaceutical industry and often associated with high costs because of the required elaborative interaction studies. Therefore, a theoretical prediction of such interactions would be beneficial. Often, material parameters such as the octanol water partition coefficient are used to predict the partitioning of migrant molecules between a solvent and a polymeric packaging material. Here, we present the investigation of the partitioning of various migrant molecules between polymers and solvents using molecular dynamics simulations for the calculation of interaction energies. Our results show that the use of a model for the interaction between the migrant and the polymer at atomistic detail can yield significantly better results when predicting the polymer solvent partitioning than a model based on the octanol water partition coefficient. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

  4. Experimental investigation of electron beam wave interactions utilising short pulses

    International Nuclear Information System (INIS)

    Wiggins, Samuel Mark

    2000-01-01

    Experiments have investigated the production of ultra-short electromagnetic pulses and their interaction with electrons in various resonant structures. Diagnostic systems used in the measurements included large bandwidth detection systems for capturing the short pulses. Deconvolution techniques have been applied to account for bandwidth limitation of the detection systems and to extract the actual pulse amplitudes and durations from the data. A Martin-Puplett interferometer has been constructed for use as a Fourier transform spectrometer. The growth of superradiant electromagnetic spikes from short duration (0.5-1.0 ns), high current (0.6-2.0 kA) electron pulses has been investigated in a Ka-band Cherenkov maser and Ka- and W-band backward wave oscillators (BWO). In the Cherenkov maser, radiation spikes were produced with a peak power ≤ 3 MW, a duration ≥ 70 ps and a bandwidth ≤ 19 %. It is shown that coherent spontaneous emission from the leading edge of the electron pulse drives these interactions, giving rise to self-amplified coherent spontaneous emission (SACSE). BWO spikes were produced with a peak power ≤ 63 MW and a pulse duration ∼ 250 ps in the Ka-band and ≤ 12 MW and ∼ 170 ps in the W-band. Evidence of superradiant evolution has been observed in the measurements of scaling laws such as power scaling with the current squared and duration scaling inversely with the fourth root of the power. An X-band free-electron maser amplifier, in which a short (1.0ns) injected radiation pulse interacts with a long (∼ 140 ns) electron beam, has been investigated. The interaction is shown to evolve in the linear regime. The peak output power was 320 kW, which corresponded to a gain, approximately constant across the band, of 42 dB. Changes to the spectrum, that occur when the input radiation pulse is injected into electrons with an energy gradient, have been analysed. (author)

  5. Investigations of the D-multi-ρ interactions

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, C.W. [Institut fuer Kernphysik (Theorie), Institute for Advanced Simulation, and Juelich Center for Hadron Physics, Forschungszentrum Juelich (Germany); Central South University, School of Physics and Electronics, Changsha (China)

    2017-09-15

    In the present work, which aims at searching for bound states, the interactions of the D-multi-ρ systems are investigated by means of the formalism of the fixed-center approximation to Faddeev equations. Reproducing the states of f{sub 2}(1270) and D{sub 1}(2420) dynamically in the two-body ρρ and ρD interactions, respectively, as the clusters of the fixed-center approximation, the state of D(3000){sup 0} is found as a molecule of D - f{sub 2} or ρ - D{sub 1} structures in the three-body interactions, where we determine its quantum number J{sup P} = 2{sup -} and find another possible state of D{sub 2}(3100) with isospin I = 3/2. In our results, there are some other predictions with uncertainties, a D{sub 3}(3160) state with I(J{sup P}) = (1)/(2)(3{sup +}) in the four-body interactions, a narrow D{sub 4}(3730) state with I(J{sup P}) = (1)/(2)(4{sup -}), a wide D{sub 4}(3410) state of I(J{sup P}) = (1)/(2)(4{sup -}), and another wide D{sub 4}(3770) state but with I(J{sup P}) = (3)/(2)(4{sup -}) in the five-body interactions, and a D{sub 5}(3570) state with I(J{sup P}) = (1)/(2)(5{sup +}) in the six-body interactions. (orig.)

  6. Experimental investigation of the piano hammer-string interaction.

    Science.gov (United States)

    Birkett, Stephen

    2013-04-01

    Experimental techniques for investigating the piano hammer-string interaction are described. It is argued that the accuracy, consistency, and scope of conclusions of previous studies can be compromised by limitations of the conventional methods relating to key inputs; physical distortion; numerical distortion, particularly when differentiation or integration of measured signals is used to derive primary response variables; contact identification; and synchronization issues. These problems are discussed, and experimental methods that have been devised to avoid them are described and illustrated by detailed results from a study of the hammer-string interaction in a vertical piano. High resolution displacements are obtained directly by non-contact high-speed imaging and quantitative motion tracking. The attention focused on achieving very accurate and consistent temporal and spatial alignment, including the objective procedure used for contact identification, allows meaningful comparisons of responses from separate tests. String motion at the strike point and on each side of it, as well as hammer motion, is obtained for eight dynamic levels from 1.06 to 2.98 m/s impact velocity. Detailed observations of the force-compression behavior of the hammer interacting with real strings are presented. The direct effects of hammer shank deflection and agraffe string pulses on the interaction are also highlighted.

  7. Optoelectronic investigation of nanodiamond interactions with human blood

    Science.gov (United States)

    Ficek, M.; Wróbel, M. S.; Wasowicz, M.; Jedrzejewska-Szczerska, M.

    2016-03-01

    We present optoelectronic investigation of in vitro interactions of whole human blood with different nanodiamond biomarkers. Plasmo-chemical modifications of detonation nanodiamond particles gives the possibility for controlling their surface for biological applications. Optical investigations reveal the biological activity of nanodiamonds in blood dependent on its surface termination. We compare different types of nanodiamonds: commercial non-modified detonation nanodiamonds, and nanodiamonds modified by MW PACVD method with H2-termination, and chemically modified nanodiamond with O2-termination. The absorption spectra, and optical microscope investigations were conducted. The results indicate haemocompatibility of non-modified detonation nanodiamond as well as modified nanodiamonds, which enables their application for drug delivery, as well as sensing applications.

  8. Detailed Investigations of Interactions between Ionizing Radiation and Neutral Gases

    Energy Technology Data Exchange (ETDEWEB)

    Landers, Allen L

    2014-03-31

    We are investigating phenomena that stem from the many body dynamics associated with ionization of an atom or molecule by photon or charged particle. Our program is funded through the Department of Energy EPSCoR Laboratory Partnership Award in collaboration with Lawrence Berkeley National Laboratory. We are using variations on the well established COLTRIMS technique to measure ions and electrons ejected during these interactions. Photoionization measurements take place at the Advanced Light Source at LBNL as part of the ALS-COLTRIMS collaboration with the groups of Reinhard Dörner at Frankfurt and Ali Belkacem at LBNL. Additional experiments on charged particle impact are conducted locally at Auburn University where we are studying the dissociative molecular dynamics following interactions with either ions or electrons over a velocity range of 1 to 12 atomic units.

  9. Molecular genetic gene-environment studies using candidate genes in schizophrenia: a systematic review.

    Science.gov (United States)

    Modinos, Gemma; Iyegbe, Conrad; Prata, Diana; Rivera, Margarita; Kempton, Matthew J; Valmaggia, Lucia R; Sham, Pak C; van Os, Jim; McGuire, Philip

    2013-11-01

    The relatively high heritability of schizophrenia suggests that genetic factors play an important role in the etiology of the disorder. On the other hand, a number of environmental factors significantly influence its incidence. As few direct genetic effects have been demonstrated, and there is considerable inter-individual heterogeneity in the response to the known environmental factors, interactions between genetic and environmental factors may be important in determining whether an individual develops the disorder. To date, a considerable number of studies of gene-environment interactions (G×E) in schizophrenia have employed a hypothesis-based molecular genetic approach using candidate genes, which have led to a range of different findings. This systematic review aims to summarize the results from molecular genetic candidate studies and to review challenges and opportunities of this approach in psychosis research. Finally, we discuss the potential of future prospects, such as new studies that combine hypothesis-based molecular genetic candidate approaches with agnostic genome-wide association studies in determining schizophrenia risk. © 2013 Elsevier B.V. All rights reserved.

  10. Interactive house investigation and radon diagnostics computer program

    International Nuclear Information System (INIS)

    Gillette, L.M.

    1990-01-01

    This paper reports on the interactive computer program called Dungeons and Radon which was developed as part of the Environmental Protection Agency's (EPA's) Radon Contractor Proficiency (RCP) Program's Radon Technology for Mitigators (RTM) course which is currently being offered in the Regional Radon Training Centers (RRTCs). The program was designed by Terry Brennan to be used in training radon mitigation contractors. The Macintosh based program consists of a series of animated, sound and voice enhanced house scenes. The participants choose where and what to investigate and where to perform diagnostic tests in order to gather enough information to design a successful mitigation system

  11. An interactive data management and analysis system for clinical investigators.

    Science.gov (United States)

    Groner, G F; Hopwood, M D; Palley, N A; Sibley, W L; Baker, W R; Christopher, T G; Thompson, H K

    1978-09-01

    An interactive minicomputer-based system has been developed that enables the clinical research investigator to personally explore and analyze his research data and, as a consequence of these explorations, to acquire more information. This system, which does not require extensive training or computer programming, enables the investigator to describe his data interactively in his own terms, enter data values while having them checked for validity, store time-oriented patient data in a carefully controlled on-line data base, retrieve data by patient, variable, and time, create subsets of patients with common characteristics, perform statistical analyses, and produce tables and graphs. It also permits data to be transferred to and from other computers. The system is well accepted and is being used by a variety of medical specialists at the three clinical research centers where it is operational. Reported benefits include less elapsed and nonproductive time, more thorough analysis of more data, greater and earlier insight into the meaning of research data, and increased publishable results.

  12. REVIEW: Genome-wide findings in schizophrenia and the role of gene-environment interplay.

    Science.gov (United States)

    Van Winkel, Ruud; Esquivel, Gabriel; Kenis, Gunter; Wichers, Marieke; Collip, Dina; Peerbooms, Odette; Rutten, Bart; Myin-Germeys, Inez; Van Os, Jim

    2010-10-01

    The recent advent of genome-wide mass-marker technology has resulted in renewed optimism to unravel the genetic architecture of psychotic disorders. Genome-wide association studies have identified a number of common polymorphisms robustly associated with schizophrenia, in ZNF804A, transcription factor 4, major histocompatibility complex, and neurogranin. In addition, copy number variants (CNVs) in 1q21.1, 2p16.3, 15q11.2, 15q13.3, 16p11.2, and 22q11.2 were convincingly implicated in schizophrenia risk. Furthermore, these studies have suggested considerable genetic overlap with bipolar disorder (particularly for common polymorphisms) and neurodevelopmental disorders such as autism (particularly for CNVs). The influence of these risk variants on relevant intermediate phenotypes needs further study. In addition, there is a need for etiological models of psychosis integrating genetic risk with environmental factors associated with the disorder, focusing specifically on environmental impact on gene expression (epigenetics) and convergence of genes and environment on common biological pathways bringing about larger effects than those of genes or environment in isolation (gene-environment interaction). Collaborative efforts that bring together expertise in statistics, genetics, epidemiology, experimental psychiatry, brain imaging, and clinical psychiatry will be required to succeed in this challenging task. © 2010 Blackwell Publishing Ltd.

  13. A mechanistic explanation of popularity: genes, rule breaking, and evocative gene-environment correlations.

    Science.gov (United States)

    Burt, Alexandra

    2009-04-01

    Previous work has suggested that the serotonergic system plays a key role in "popularity" or likeability. A polymorphism within the 5HT-sub(2A) serotonin receptor gene (-G1438A) has also been associated with popularity, suggesting that genes may predispose individuals to particular social experiences. However, because genes cannot code directly for others' reactions, any legitimate association should be mediated via the individual's behavior (i.e., genes-->behaviors-->social consequences), a phenomenon referred to as an evocative gene-environment correlation (rGE). The current study aimed to identify one such mediating behavior. The author focused on rule breaking given its prior links to both the serotonergic system and to increased popularity during adolescence. Two samples of previously unacquainted late-adolescent boys completed a peer-based interaction paradigm designed to assess their popularity. Analyses revealed that rule breaking partially mediated the genetic effect on popularity, thereby furthering our understanding of the biological mechanisms that underlie popularity. Moreover, the present results represent the first meaningfully explicated evidence that genes predispose individuals not only to particular behaviors but also to the social consequences of those behaviors. (c) 2009 APA, all rights reserved.

  14. Experimental investigation of interactions between proteins and carbon nanomaterials

    Science.gov (United States)

    Sengupta, Bishwambhar

    The global market for nanomaterials based products is forecasted to reach $1 trillion per annum per annum for 2015. Engineered nanomaterials (ENMs) exhibit unique physicochemical properties with potential to impact diverse aspects of society through applications in electronics, renewable energy, and medicine. While the research and proposed applications of ENMs continue to grow rapidly, the health and safety of ENMs still remains a major concern to the public as well as to policy makers and funding agencies. It is now widely accepted that focused efforts are needed for identifying the list of physicochemical descriptors of ENM before they can be evaluated for nanotoxicity and biological response. This task is surprisingly challenging, as many physicochemical properties of ENMs are closely inter related and cannot be varied independently (e.g. increasing the size of an ENM can introduce additional defects). For example, varying toxic response may ensue due to different methods of nanomaterial preparation, dissimilar impurities and defects. Furthermore, the inadvertent coating of proteins on ENM surface in any biological milieu results in the formation of the so-called "protein/bio-corona" which can in turn alter the fate of ENMs and their biological response. Carbon nanomaterials (CNMs) such as carbon nanotubes, graphene, and graphene oxide are widely used ENMs. It is now known that defects in CNMs play an important role not only in materials properties but also in the determination of how materials interact at the nano-bio interface. In this regard, this work investigates the influence of defect-induced hydrophilicity on the bio-corona formation using micro Raman, photoluminescence, infrared spectroscopy, electrochemistry, and molecular dynamics simulations. Our results show that the interaction of proteins (albumin and fibrinogen) with CNMs is strongly influenced by charge transfer between them, inducing protein unfolding which enhances conformational entropy and

  15. A preliminary investigation into genotype x environment interaction ...

    African Journals Online (AJOL)

    uvp

    2014-08-24

    Aug 24, 2014 ... Genotype x environment interaction (G x E) in dairy cattle is a contentious ... environments, if it exists, with a negative impact on genetic response ..... interaction for Holstein milk yield in Colombia, Mexico and Puerto Rico.

  16. [Association between MAOA-u VNTR polymorphism and its interaction with stressful life events and major depressive disorder in adolescents].

    Science.gov (United States)

    Ma, Jing; Yu, Shun-Ying; Liang, Shan; Ding, Jun; Feng, Zhe; Yang, Fan; Gao, Wei-Jia; Lin, Jia-Ni; Huang, Chun-Xiang; Liu, Xue-Jun; Su, Lin-Yan

    2013-07-01

    To investigate whether the genetic polymorphism, upstream variable number of tandem repeats (uVNTR), in the monoamine oxidase A (MAOA) gene, is associated with major depressive disorder (MDD) in adolescents and to test whether there is gene-environment interaction between MAOA-uVNTR polymorphism and stressful life events (SLEs). A total of 394 Chinese Han subjects, including 187 adolescent patients with MDD and 207 normal students as a control group, were included in the study. Genotyping was performed by SNaP-shot assay. SLEs in the previous 12 months were evaluated. The groups were compared in terms of the frequency distributions of MAOA-uVNTR genotypes and alleles using statistical software. The binary logistic regression model of gene-environment interaction was established to analyze the association of the gene-environment interaction between MAOA-u VNTR genotypes and SLEs with adolescent MDD. The distribution profiles of MAOA-u VNTR genotypes and alleles were not related to the onset of MDD, severity of depression, comorbid anxiety and suicidal ideation/behavior/attempt in adolescents. The gene-environment interaction between MAOA-u VNTR genotypes and SLEs was not associated with MDD in male or female adolescents. It is not proven that MAOA-u VNTR polymorphism is associated with adolescent MDD. There is also no gene-environment interaction between MAOA-u VNTR polymorphism and SLEs that is associated with adolescent MDD.

  17. Genes, Environments, and Sex Differences in Alcohol Research.

    Science.gov (United States)

    Salvatore, Jessica E; Cho, Seung Bin; Dick, Danielle M

    2017-07-01

    The study of sex differences has been identified as one way to enhance scientific reproducibility, and the National Institutes of Health (NIH) have implemented a new policy to encourage the explicit examination of sex differences. Our goal here is to address sex differences in behavioral genetic research on alcohol outcomes. We review sex differences for alcohol outcomes and whether the source and magnitude of genetic influences on alcohol consumption and alcohol use disorder (AUD) are the same across sexes; describe common research designs for studying sex-specific gene-by-environment interaction (G × E) effects; and discuss the role of statistical power and theory when testing sex-specific genetic effects. There are robust sex differences for many alcohol outcomes. The weight of evidence suggests that the source and magnitude of genetic influences on alcohol consumption and AUD are the same across sexes. Whether there are sex-specific G × E effects has received less attention to date. The new NIH policy necessitates a systematic approach for studying sex-specific genetic effects in alcohol research. Researchers are encouraged to report power for tests of these effects and to use theory to develop testable hypotheses, especially for studies of G × E.

  18. Investigation of physical structures and interactions at high energy

    International Nuclear Information System (INIS)

    Anderson, E.W.

    1991-01-01

    Contract AC02-85ER40193 supports the investigation of fundamental structures and interactions at high energy by the Iowa State University Alpha HEP Group. Three major activities constitute the present focus of our research. Experiment E-735, performed at the Fermilab Tevatron Collider, is a search for a deconfined quark-gluon plasma phase of hadronic matter predicted to occur when temperatures of 240 MeV are achieved. The primary data were obtained in 1988--1989, from these data the collaboration is analyzing the charged particle multiplicity and transverse momentum distributions of the produced secondaries. These measurements are regarded on theoretical grounds to be sensitive indicators of the formation of a high-temperature plasma. The TPC detector, installed in the PEP ring at SLAC, has accumulated about 60,000 hadronic events at 29 GeV center-of-mass energy. Several thousand events have high-precision vertex chamber measurements. Physics analysis of charmed quark events, in addition to a measurement of the QCD strong coupling, are in progress. Our identification and reconstruction of D o , D*, and D s , charmed mesons will be useful for subsequent B meson studies in the TPC detector. The SSC liquid argon major subsystem tests at BNL and studies of gauge boson identification and reconstruction for large SSC detectors are in progress. Several crucial problems related to calorimeter geometries, coil geometries, and discrimination methods in full SSC events have been solved, and work is in progress on a one million event test of WW scattering capability up to 2 TeV. Our participation in the subsystem proposal involves construction of the module, data-taking at the AGS, and data analysis

  19. The interaction between cannabis use and the Val158Met polymorphism of the COMT gene in psychosis: A transdiagnostic meta - analysis

    NARCIS (Netherlands)

    Vaessen, Thomas Stephanus Johannes; de Jong, Lea; Schäfer, Annika Theresia; Damen, Thomas; Uittenboogaard, Aniek; Krolinski, Pauline; Nwosu, Chinyere Vicky; Pinckaers, Florentina Maria Egidius; Rotee, Iris Leah Marije; Smeets, Antonius Petrus Wilhelmus; Ermiş, Ayşegül; Kennedy, James L.; Nieman, Dorien H.; Tiwari, Arun; van Os, Jim; Drukker, Marjan

    2018-01-01

    Neither environmental nor genetic factors are sufficient to predict the transdiagnostic expression of psychosis. Therefore, analysis of gene-environment interactions may be productive. A meta-analysis was performed using papers investigating the interaction between cannabis use and catechol-O-methyl

  20. Experimental Investigation of Turbulence-Chemistry Interaction in High-Reynolds-Number Turbulent Partially Premixed Flames

    Science.gov (United States)

    2016-06-23

    AFRL-AFOSR-VA-TR-2016-0277 Experimental Investigation of Turbulence-Chemistry Interaction in High- Reynolds -Number Turbulent Partially Premixed...4. TITLE AND SUBTITLE [U] Experimental investigation of turbulence-chemistry interaction in high- Reynolds -number 5a. CONTRACT NUMBER turbulent...for public release Final Report: Experimental investigation of turbulence-chemistry interaction in high- Reynolds -number turbulent partially premixed

  1. Application of proteomics to investigate barley-Fusarium graminearum interaction

    OpenAIRE

    Yang, Fen; Finnie, Christine; Jacobsen, Susanne

    2011-01-01

    Due to the great loss of barley grain yield and quality in addition to mycotoxins contamination caused by Fusarium head blight (FHB), it is essential to understand the molecular interaction between barley and Fusarium graminearum, one of the primary Fusarium species causing FHB, in order to control the disease. Due to the advantages of gel-based proteomics that differentially expressed proteins involved in the interaction can be directly detected by comparing protein profiles displayed on 2-D...

  2. Investigating Near Space Interaction Regions: Developing a Remote Observatory

    Science.gov (United States)

    Gallant, M.; Mierkiewicz, E. J.; Oliversen, R. J.; Jaehnig, K.; Percival, J.; Harlander, J.; Englert, C. R.; Kallio, R.; Roesler, F. L.; Nossal, S. M.; Gardner, D.; Rosborough, S.

    2016-12-01

    The Investigating Near Space Interaction Regions (INSpIRe) effort will (1) establish an adaptable research station capable of contributing to terrestrial and planetary aeronomy; (2) integrate two state-of-the-art second generation Fabry-Perot (FP) and Spatial Heteorodyne Spectrometers (SHS) into a remotely operable configuration; (3) deploy this instrumentation to a clear-air site, establishing a stable, well-calibrated observatory; (4) embark on a series of observations designed to contribute to three major areas of geocoronal research: geocoronal physics, structure/coupling, and variability. This poster describes the development of the INSpIRe remote observatory. Based at Embry-Riddle Aeronautical University (ERAU), initiative INSpIRe provides a platform to encourage the next generation of researchers to apply knowledge gained in the classroom to real-world science and engineering. Students at ERAU contribute to the INSpIRe effort's hardware and software needs. Mechanical/optical systems are in design to bring light to any of four instruments. Control software is in development to allow remote users to control everything from dome and optical system operations to calibration and data collection. In April 2016, we also installed and tested our first science instrument in the INSpIRe trailer, the Redline DASH Demonstration Instrument (REDDI). REDDI uses Doppler Asymmetric Spatial Heterodyne (DASH) spectroscopy, and its deployment as part of INSpIRe is a collaborative research effort between the Naval Research Lab, St Cloud State University, and ERAU. Similar to a stepped Michelson device, REDDI measures oxygen (630.0 nm) winds from the thermosphere. REDDI is currently mounted in a temporary location under INSpIRe's main siderostat until its entrance optical system can be modified. First light tests produced good signal-to-noise fringes in ten minute integrations, indicating that we will soon be able to measure thermospheric winds from our Daytona Beach testing site

  3. Gene-Environment Correlation Underlying the Association between Parental Negativity and Adolescent Externalizing Problems

    Science.gov (United States)

    Marceau, Kristine; Horwitz, Briana N.; Narusyte, Jurgita; Ganiban, Jody M.; Spotts, Erica L.; Reiss, David; Neiderhiser, Jenae M.

    2013-01-01

    Studies of adolescent or parent-based twins suggest that gene-environment correlation (rGE) is an important mechanism underlying parent-adolescent relationships. However, information on how parents' and children's genes and environments influence correlated parent "and" child behaviors is needed to distinguish types of rGE. The present…

  4. Gene-Environment Interplay in Internalizing Disorders: Consistent Findings across Six Environmental Risk Factors

    Science.gov (United States)

    Hicks, Brian M.; Dirago, Ana C.; Iacono, William G.; McGue, Matt

    2009-01-01

    Background: Behavior genetic methods can help to elucidate gene-environment (G-E) interplay in the development of internalizing (INT) disorders (i.e., major depression and anxiety disorders). To date, however, no study has conducted a comprehensive analysis examining multiple environmental risk factors with the purpose of delineating general…

  5. Investigating EFL Classroom Interaction Process in Iraqi Intermediate Schools

    Directory of Open Access Journals (Sweden)

    Muna Mohammed Abbas Alkhateeb

    2017-09-01

    Full Text Available In recent times, the traditional interaction structures of English both language classrooms and roles of teachers and students are gradually changing. This marks the shift from the teacher-centered classrooms to student-centered classrooms; moving towards ‘student-centered learning’ and‘collaborative working modes’. The contemporary educational world views teachers and students as communicators. In such situations students get more opportunity to ‘participate’, ‘observe’, ‘reflect on’ and ‘practice social ways’. These opportunities expose the students to a more ‘meaning-making’ and ‘knowledge construction processes’. The shift from traditional teaching and learning process to the contemporary one has posed great challenges for teachers, who are always working under pressure to complete the syllabus designed for the academic year. In such a situation it is very important to ascertain if this idea of student-centered classroom is present in the recent classroom. Educationally oriented research into classroom interaction makes it essential for further studies into the classroom interaction in the modern classroom. Hence, this study aims to observe the interaction process that takes place in English classrooms of four government schools in Hilla (Centre of Babylon Governorate. This paper also suggests measures to improve classroom interaction and language learning in the English classes. The main findings from the study are as follows: (a the classroom interaction is teacher-centered, (b teachers partially facilitate learning, the classrooms are controlled by teachers (c the ratio of the teacher-talk is more than student-talk."

  6. SIMULATION AND INVESTIGATION OF TIRE TREAD BLOCKS INTERACTION WITH ICE

    Directory of Open Access Journals (Sweden)

    Andrius Ružinskas

    2017-12-01

    Full Text Available The car tire is an essential subject analysing its interaction with the road. From tire’s tread condition, geometry and rubber compound depends grip and vehicle stability. This is especially relevant in winter time, when roads are covered with the layer of snow or ice. Generally, new tires are tested in real traffic conditions using vehicles. However, ensuring these conditions requires many resources and sometimes it could be a big challenge. For this reason, simulation of the tire interaction with the road becomes more important in nowadays tire researches. Since the tire is a complex engineering subject, the tire tread blocks could be separated for individual analysis. The interaction between the dry ice and the tread block with sipes was analysed using finite element analysis. The tread block was described using hyperelastic Mooney­Rivlin material model. The deformations, distribution of the contact pressure and shear stresses were obtained for the soft and hard rubber compounds with different vertical load conditions. Also a solid tread block interaction was analysed and it was found that values of contact pressure and shear stresses are much lower comparing to siped tread block.

  7. Electrochemical Investigation of the Interaction between Catecholamines and ATP.

    Science.gov (United States)

    Taleat, Zahra; Estévez-Herrera, Judith; Machado, José D; Dunevall, Johan; Ewing, Andrew G; Borges, Ricardo

    2018-02-06

    The study of the colligative properties of adenosine 5'-triphosphate (ATP) and catecholamines has received the attention of scientists for decades, as they could explain the capabilities of secretory vesicles (SVs) to accumulate neurotransmitters. In this Article, we have applied electrochemical methods to detect such interactions in vitro, at the acidic pH of SVs (pH 5.5) and examined the effect of compounds having structural similarities that correlate with functional groups of ATP (adenosine, phosphoric acid and sodium phosphate salts) and catecholamines (catechol). Chronoamperometry and fast scan cyclic voltammetry (FSCV) provide evidence compatible with an interaction of the catechol and adenine rings. This interaction is also reinforced by an electrostatic interaction between the phosphate group of ATP and the protonated ammonium group of catecholamines. Furthermore, chronoamperometry data suggest that the presence of ATP subtlety reduces the apparent diffusion coefficient of epinephrine in aqueous media that adds an additional factor leading to a slower rate of catecholamine exocytosis. This adds another plausible mechanism to regulate individual exocytosis events to alter communication.

  8. Application of proteomics to investigate barley-Fusarium graminearum interaction

    DEFF Research Database (Denmark)

    Yang, Fen

    in plants under low N and iv) proteomes of uninfected plants were similar under two N levels. Correlation of level of proteolysis induced by the fungus with measurement of Fusarium-damaged kernels, fungal biomass and mycotoxin levels indicated that FHB was more severe in barley with low N. In Chapter 3......, the molecular mechanisms of barley defense to Fusarium graminearum at the early infection stage were studied. Antibodies against barley β-amylases were shown to be the markers for infection at proteome level and for selection of the time for proteome analysis before extensive degradation caused by the fungus...... the disease. Due to the advantages of gel-based proteomics that differentially expressed proteins involved in the interaction can be directly detected by comparing protein profiles displayed on 2-D gels, it is used as a tool for studying the barley- Fusarium graminearum interaction form three different...

  9. Investigation of sodium - carbon dioxide interactions with calorimetric studies

    International Nuclear Information System (INIS)

    Simon, N.; Latge, C.; Gicquel, L.

    2007-01-01

    The supercritical CO 2 Brayton cycle could be a promising option to enhance the competitiveness of future Sodium fast reactors but it is highly necessary to get thermodynamic and kinetics information on potential sodium-CO 2 chemical reactions and their consequences. We have studied the interaction between Na and CO 2 via calorimetric methods. These methods are able to point out exothermic/endothermic phenomena and to measure heat of chemical reactions. The main feature of the Na/CO 2 interaction seems to be its sharp dependence on temperature. At low temperature, below 500 C degrees, CO 2 and sodium react and exhibit an induction time which decreases when temperature increases. Above 500 C degrees, we observe a global phenomenon with a fast and instantaneous chemical reaction which may be understood as an auto-combustion of CO 2 in sodium. We clearly demonstrated that Na/CO 2 interaction does not proceed as an auto-catalytic process and is more satisfactorily explained by the occurring of an auto-combustion phenomenon

  10. Childhood problem behavior and parental divorce: evidence for gene-environment interaction

    NARCIS (Netherlands)

    S.C.C. Robbers (Sylvana); F.V.A. van Oort (Floor); A.C. Huizink (Anja); F.C. Verhulst (Frank); C.E.M. van Beijsterveldt (Toos); D.I. Boomsma (Dorret); M. Bartels (Meike)

    2012-01-01

    textabstractObjective: The importance of genetic and environmental influences on children's behavioral and emotional problems may vary as a function of environmental exposure. We previously reported that 12-year-olds with divorced parents showed more internalizing and externalizing problems than

  11. Gene-environment interactions in considering physical activity for the prevention of dementia

    Directory of Open Access Journals (Sweden)

    Kristyn Alissa Bates

    2015-09-01

    Full Text Available Alzheimer's disease (AD, the most common neurodegenerative disease worldwide, ranks as one of the most feared diseases in the world. Similarly, recent studies suggest that AD may be the third leading cause of death in the United States, behind heart disease and cancer. In the absence of a cure or effective treatment, strategies to prevent or delay the onset and progression of the disease are desperately needed. Decades of research have identified key risk and protective factors including genetic polymorphism in the APOE gene, age and lifestyle factors. Physical activity (PA is emerging as an attractive primary prevention strategy. This review will summarise the latest findings supporting the role of physical activity in the prevention of AD, including possible mechanisms and the influence of genetics on disease prevention. Given that AD and other dementias are recognised as a world health priority, public health strategies are needed to incorporate promoting the health benefits of physical activity across the lifespan.

  12. Detection of gene-environment interaction in pedigree data using genome-wide genotypes

    NARCIS (Netherlands)

    Nivard, Michel G.; Middeldorp, Christel M.; Lubke, Gitta; Hottenga, Jouke-Jan; Abdellaoui, Abdel; Boomsma, Dorret I.; Dolan, Conor V.

    2016-01-01

    Heritability may be estimated using phenotypic data collected in relatives or in distantly related individuals using genome-wide single nucleotide polymorphism (SNP) data. We combined these approaches by re-parameterizing the model proposed by Zaitlen et al and extended this model to include

  13. Gene-Environment Interactions of Circadian-Related Genes for Cardiometabolic Traits

    DEFF Research Database (Denmark)

    Dashti, Hassan S; Follis, Jack L; Smith, Caren E

    2015-01-01

    OBJECTIVE: Common circadian-related gene variants associate with increased risk for metabolic alterations including type 2 diabetes. However, little is known about whether diet and sleep could modify associations between circadian-related variants (CLOCK-rs1801260, CRY2-rs11605924, MTNR1B-rs13871...

  14. Gene-Gene and Gene-Environment Interactions in the Etiology of Breast Cancer

    Science.gov (United States)

    2007-06-01

    family consume per month (50g)? 1. Vegetable oil : __________ (50g) [__]__]__] 2. Soy bean oil : ___________ (50g) [__]__]__] 3...and redissolving in a methanol acetate buffer mixture. Liquid chromatography photo diode array multiple generation mass spectrometry (LC/PDA/MS...delivery liquid chromatography system with multiple channel diode-array detection and a quadrupole ion trap mass spectrometer model ’Advantage

  15. Gene-Environment Interaction and Breast Cancer on Long Island, NY

    National Research Council Canada - National Science Library

    Teitelbaum, Susan

    2006-01-01

    ...), a large population-based, case-control study of the environment and breast cancer. Participants completed an in-person interviewer-administered interview, donated blood and urine samples, and had home environment samples...

  16. Gene-Environment Interaction and Breast Cancer on Long Island, NY

    Science.gov (United States)

    2008-05-01

    Dietary flavonoid intake and breast cancer survival among women on Long Island. Cancer Epidemiol Biomarkers Prev. 2007 Nov;16(11):2285-92...Kuklenyik, Z., Needham, L.L., Calafat, A.M., 2005. Automated on-line column-switching HPLC -MS/MS method with peak focusing for the determination of...action. Environ Health Perspect 110:917–921. Rybak ME, Parker DL, Pfeiffer CM. 2006. Determination of Urinary Phytoestrogens by HPLC -MS/MS: A Comparison

  17. Challenges of Analysing Gene-Environment Interactions in Mouse Models of Schizophrenia

    Directory of Open Access Journals (Sweden)

    Peter L. Oliver

    2011-01-01

    Full Text Available The modelling of neuropsychiatric disease using the mouse has provided a wealth of information regarding the relationship between specific genetic lesions and behavioural endophenotypes. However, it is becoming increasingly apparent that synergy between genetic and nongenetic factors is a key feature of these disorders that must also be taken into account. With the inherent limitations of retrospective human studies, experiments in mice have begun to tackle this complex association, combining well-established behavioural paradigms and quantitative neuropathology with a range of environmental insults. The conclusions from this work have been varied, due in part to a lack of standardised methodology, although most have illustrated that phenotypes related to disorders such as schizophrenia are consistently modified. Far fewer studies, however, have attempted to generate a “two-hit” model, whereby the consequences of a pathogenic mutation are analysed in combination with environmental manipulation such as prenatal stress. This significant, yet relatively new, approach is beginning to produce valuable new models of neuropsychiatric disease. Focussing on prenatal and perinatal stress models of schizophrenia, this review discusses the current progress in this field, and highlights important issues regarding the interpretation and comparative analysis of such complex behavioural data.

  18. Gene-environment interactions of circadian-related genes for cardiometabolic traits

    Science.gov (United States)

    Objective: Common circadian-related gene variants associate with increased risk for metabolic alterations including type 2 diabetes. However, little is known about whether diet and sleep could modify associations between circadian-related variants (CLOCK-rs1801260, CRY2-rs11605924, MTNR1B-rs1387153,...

  19. Microscopic investigation of the 12C + 12C interaction

    International Nuclear Information System (INIS)

    Baye, D.; Pecher, N.; Brussels Univ.

    1982-01-01

    The 12 C + 12 C system is studied in the framework of the generator coordinate method. Each 12 C nucleus is described by a closed psub(3/2) subshell. Phase shifts and resonances are determined for several effective two-body interactions involving a spin-orbit term. The existence and properties of simple local equivalent potentials for the 12 C + 12 C collision are discussed. The 12 C + 12 C system is too light to be well described by potentials independent of the angular momentum or weakly dependent on it. (orig.)

  20. Further investigations of the NN interaction in the Skyrme model

    International Nuclear Information System (INIS)

    Kaelbermann, G.; Eisenberg, J.M.

    1989-01-01

    We examine the influence of the coupling to NΔ and ΔΔ degrees of freedom for the NN interaction as derived in the Skyrme model, carrying out an extensive search for parameters in the basic Lagrangian that will yield both reasonable single-baryon results and appreciable attraction. Separately the free one-body skyrmeon solution and an improved two-body solution are inserted in the product ansatz for the two-body system both with and without time-dependent dynamical terms. No appreciable central attraction between nucleons is found with either of these approaches. (author)

  1. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance

    Science.gov (United States)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, "interactive alignment" and "interpersonal synergy", and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy…

  2. Experimental Investigation of Hypersonic Flow and Plasma Aerodynamic Actuation Interaction

    International Nuclear Information System (INIS)

    Sun Quan; Cheng Bangqin; Li Yinghong; Cui Wei; Yu Yonggui; Jie Junhun

    2013-01-01

    For hypersonic flow, it was found that the most effective plasma actuator is derived from an electromagnetic perturbation. An experimental study was performed between hypersonic flow and plasma aerodynamic actuation interaction in a hypersonic shock tunnel, in which a Mach number of 7 was reached. The plasma discharging characteristic was acquired in static flows. In a hypersonic flow, the flow field can affect the plasma discharging characteristics. DC discharging without magnetic force is unstable, and the discharge channel cannot be maintained. When there is a magnetic field, the energy consumption of the plasma source is approximately three to four times larger than that without a magnetic field, and at the same time plasma discharge can also affect the hypersonic flow field. Through schlieren pictures and pressure measurement, it was found that plasma discharging could induce shockwaves and change the total pressure and wall pressure of the flow field

  3. Investigating the role of aesthetics for interaction design

    DEFF Research Database (Denmark)

    Stavrakos, Stavros-Konstantinos; Ahmed-Kristensen, Saeema

    2013-01-01

    Two important aspects when designing products is to focus on comfort and to define the aesthetic and emotional value of the product. The main purpose of this research is to answer the question of how attractiveness perceived through the sensory inputs affects the assessment of comfort as well...... when the levels of attractiveness increase and vice versa. The findings further indicate that there are strong, significant correlations between scores of comfort and product adjectives commonly used to describe product attributes such as size, weight and surface material. Hence, there is an emotional...... dimension of comfort which is initiated by the visual input during a human – product interaction and is affected by the attractiveness towards the product. In their endeavor to develop successful and comfortable products designers should focus more on attractiveness....

  4. Quantitative image analysis for investigating cell-matrix interactions

    Science.gov (United States)

    Burkel, Brian; Notbohm, Jacob

    2017-07-01

    The extracellular matrix provides both chemical and physical cues that control cellular processes such as migration, division, differentiation, and cancer progression. Cells can mechanically alter the matrix by applying forces that result in matrix displacements, which in turn may localize to form dense bands along which cells may migrate. To quantify the displacements, we use confocal microscopy and fluorescent labeling to acquire high-contrast images of the fibrous material. Using a technique for quantitative image analysis called digital volume correlation, we then compute the matrix displacements. Our experimental technology offers a means to quantify matrix mechanics and cell-matrix interactions. We are now using these experimental tools to modulate mechanical properties of the matrix to study cell contraction and migration.

  5. Investigation of uranyl phosphite interaction with some amides

    International Nuclear Information System (INIS)

    Avduevskaya, K.A.; Ragulina, N.B.; Rozanov, I.A.; Mukhajlov, Yu.N.; Kanishcheva, A.S.; Grevtseva, T.G.

    1981-01-01

    Uranyl (amide) phosphitocomplexes of [UO 2 HPO 3 H 2 OAA]xH 2 O, [UO 2 HPO 3 (AA) 2 ], [UO 2 HPO 3 H 2 O DMC], [UO 2 HPO 3 H 2 ODMFA], [UO 2 HPO 3 DAMA] and UO 2 HPO 3 x2FAxH 2 O compositions, where AA-acetamide; DMC-N, N-dimetyl carbamide, DMFA-dimetyl formamide; DAMA-diamide of malonic acid; FA-formamide, are separated, identified and investigated. Derivatives of mono substituted uranyl phosphite of UO 2 (H 2 PO 3 ) 2 x2FA and [UO 2 (H 2 PO 3 ) 2 H 2 O]x2TMC composition (where TMC-tetramethyl carbamide), are synthesized. Structures of complexes with DAMA, TMC, DMFA and acid dimethyl-ammonium diphosphitouranylate-(CH 3 ] 2 NH 2 x[UO 2 (HPO 3 ) 3 (H 2 PO 3 )] are investigated [ru

  6. Modelling of water-rock interaction at TVO investigation sites

    International Nuclear Information System (INIS)

    Pitkaenen, P.; Leino-Forsman, H.

    1992-12-01

    The geochemistry of the groundwater at the Kivetty, Syyry and Olkiluoto site investigation areas in Finland for nuclear waste disposal is evaluated. The hydrogeological data is collected from boreholes drilled down to 100-m depth into crystalline bedrock. The interpretation is based on groundwater chemistry and isotope data, mineralogical data, and the structure and hydrology of the bedrock, using correlation diagrams and the thermodynamic calculations (PHREEQE,EQ3NR). The hydrogeochemistry and major processes controlling the groundwater chemistry are discussed

  7. A review of gene-environment correlations and their implications for autism: a conceptual model.

    Science.gov (United States)

    Meek, Shantel E; Lemery-Chalfant, Kathryn; Jahromi, Laudan B; Valiente, Carlos

    2013-07-01

    A conceptual model is proposed that explains how gene-environment correlations and the multiplier effect function in the context of social development in individuals with autism. The review discusses the current state of autism genetic research, including its challenges, such as the genetic and phenotypic heterogeneity of the disorder, and its limitations, such as the lack of interdisciplinary work between geneticists and social scientists. We discuss literature on gene-environment correlations in the context of social development and draw implications for individuals with autism. The review expands upon genes, behaviors, types of environmental exposure, and exogenous variables relevant to social development in individuals on the autism spectrum, and explains these factors in the context of the conceptual model to provide a more in-depth understanding of how the effects of certain genetic variants can be multiplied by the environment to cause largely phenotypic individual differences. Using the knowledge gathered from gene-environment correlations and the multiplier effect, we outline novel intervention directions and implications. PsycINFO Database Record (c) 2013 APA, all rights reserved.

  8. AESOP: A Python Library for Investigating Electrostatics in Protein Interactions.

    Science.gov (United States)

    Harrison, Reed E S; Mohan, Rohith R; Gorham, Ronald D; Kieslich, Chris A; Morikis, Dimitrios

    2017-05-09

    Electric fields often play a role in guiding the association of protein complexes. Such interactions can be further engineered to accelerate complex association, resulting in protein systems with increased productivity. This is especially true for enzymes where reaction rates are typically diffusion limited. To facilitate quantitative comparisons of electrostatics in protein families and to describe electrostatic contributions of individual amino acids, we previously developed a computational framework called AESOP. We now implement this computational tool in Python with increased usability and the capability of performing calculations in parallel. AESOP utilizes PDB2PQR and Adaptive Poisson-Boltzmann Solver to generate grid-based electrostatic potential files for protein structures provided by the end user. There are methods within AESOP for quantitatively comparing sets of grid-based electrostatic potentials in terms of similarity or generating ensembles of electrostatic potential files for a library of mutants to quantify the effects of perturbations in protein structure and protein-protein association. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  9. Investigation of nuclear interactions around 20 TeV

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Y [Waseda Univ., Tokyo (Japan). Science and Engineering Research Lab.; Sugimoto, H; Saito, T

    1976-12-01

    Nuclear interactions at a mean energy of about 20 TeV are studied by means of a nuclear emulsion chamber with jet producer. In the present analysis, particular emphasis is placed on the experimental condition. The transverse momentum spectrum of secondary ..gamma.. rays is approximated by a single exponential in a range of 0.3

  10. Investigation of heavy quark and multiple interactions at HERA

    International Nuclear Information System (INIS)

    Magro, L.M.

    2005-09-01

    This thesis is oriented to the study of heavy quark photoproduction and multiple interactions, MI. For this reason we search for D* Mesons, in order to tag the charm quark, and we restrict ourselves in the region: Q 2 2 . For the theoretical calculations we use two Monte Carlo event generators: RAPGAP 3.1 and PYTHIA 6.2. Heavy quark production provides a large hard scale and therefore a small α s , which allows to test the perturbative QCD theory. On the other hand, MI has been proven to be important in hadron-hadron collisions. In this thesis, using MC event generators, we search for possible signals of MI in heavy quark production in electron-proton, ep, collisions. The thesis begins with a Theoretical Overview, with an introduction to ep collisions physics and the heavy quark photoproduction. We also give an introduction to the MI model included in PYTHIA. The next chapter introduces the concept of jet and presents some methods for the Heavy Quark Identification. After these two theoretical chapters there is a study of the direct and photon resolved processes, as well as the parton showering with RAPGAP. Since this thesis is oriented to the study of MI, PYTHIA plays a very important role because it includes a MI model also for ep collisions. Therefore, the fourth chapter is oriented to study the different steps in the event generation in PYTHIA. Chapter 7 is a D* Meson photoproduction study, where we include a comparison between the data, taken from the PhD Thesis of Gero Flucke. Finally, chapter 8 is a search for possible signals on MI. In hadron-hadron collisions it is clear that MI play a role. In ep collisions it is not so clear although MI could play a role in resolved photon events. The aim of this chapter is to find signals where HERA measurements could be sensitive to MI. (orig.)

  11. Final Report on Investigation of the Electron Interactions in Graphene

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Philip [Columbia University

    2015-02-14

    In graphene, combined with the real spin degree of freedom, which exhibits SU(2) symmetry, the total internal degrees of freedom of graphene carriers is thus described by a larger SU(4) symmetry, which produces a richer space for potential phenomena of emergent correlated electron phenomena. The major part of this proposal is exploring this unique multicomponent correlated system in the quantum limit. In the current period of DOE BES support we have made several key advances that will serve as a foundation for the new studies in this proposal. Employing the high-mobility encapsulated graphene heterostructures developed during the current phase of research, we have investigated spin and valley quantum Hall ferromagnetism in graphene and discovered a spin phase transition leading to a quantum spin Hall analogue. We have also observed the fractal quantum Hall effect arising from the Hofstadter’s butterfly energy spectrum. In addition, we have discovered multiband transport phenomena in bilayer graphene at high carrier densities.

  12. Investigation of electron heating in laser-plasma interaction

    Directory of Open Access Journals (Sweden)

    A Parvazian

    2013-03-01

    Full Text Available  In this paper, stimulated Raman scattering (SRS and electron heating in laser plasma propagating along the plasma fusion is investigated by particle-in cell simulation. Applying an external magnetic field to plasma, production of whistler waves and electron heating associated with whistler waves in the direction perpendicular to external magnetic field was observed in this simulation. The plasma waves with low phase velocities, generated in backward-SRS and dominateing initially in time and space, accelerated the backward electrons by trapping them. Then these electrons promoted to higher energies by the forward-SRS plasma waves with high phase velocities. This tow-stage electron acceleration is more efficient due to the coexistence of these two instabilities.

  13. Investigation of electron heating in laser-plasma interaction

    International Nuclear Information System (INIS)

    Parvazian, A.; Haji Sharifi, K.

    2013-01-01

    In this paper, stimulated Raman scattering and electron heating in laser plasma propagating along the plasma fusion is investigated by particle-in cell simulation. Applying an external magnetic field to plasma, production of whistler waves and electron heating associated with whistler waves in the direction perpendicular to external magnetic field was observed in this simulation. The plasma waves with low phase velocities, generated in backward-stimulated Raman scattering and dominating initially in time and space, accelerated the backward electrons by trapping them. Then these electrons promoted to higher energies by the forward-stimulated Raman scattering plasma waves with high phase velocities. This two-stage electron acceleration is more efficient due to the coexistence of these two instabilities.

  14. Investigation of microbial-mineral interactions by Moessbauer spectroscopy

    International Nuclear Information System (INIS)

    Sawicki, J.A.; Brown, D.A.

    1998-01-01

    Moessbauer spectroscopy was used to investigate the reactions of microbes with iron minerals in aqueous solutions and as components of rocks in banded iron formations and granite. A microbial biofilm that formed on a wall of an excavated granite vault in a deep underground laboratory initiated this research. At the aerobic face of the biofilm, iron was found in a form of ferrihydrite; in the anaerobic face against the rock, iron was found as very small siderite particles. Laboratory incubations of the biofilm microbial consortium showed different mineral species could be formed. When the microbial consortium from the biofilm was incubated with magnetite grains, up to about 10% of the iron was altered in three weeks to hematite. The ability of the consortium to precipitate iron both as Fe 2+ and Fe 3+ in close proximity may have a bearing on the deposition of banded iron formations. These reactions could also be important in microbially induced corrosion

  15. Theoretical investigation of electron-positive ion/atom interactions

    International Nuclear Information System (INIS)

    Msezane, A.Z.

    1992-01-01

    Very brief summaries are given on three research topics. Electron impact elastic, excitation, and total cross sections for K were investigated by using elaborate Cl target wave functions in the close-coupling approximation. Photoionization cross sections from ground-state Na were calculated near the 2s 2 2p 5 3s and 2s2p 6 3s inner-shell thresholds; also, the photoionization cross sections of excited 3p 2 P o and 3d 2 D states were calculated with the R-matrix methodology near the 2s2p 6 3s thresholds. A numerical approach was developed to calculate the charge transfer matrix elements for ion-atom(ion) collisions; this was used for the proton-hydrogen collision problem as an illustration

  16. Investigating hadronic resonances in pp interactions with HADES

    Directory of Open Access Journals (Sweden)

    Przygoda Witold

    2015-01-01

    Full Text Available In this paper we report on the investigation of baryonic resonance production in proton-proton collisions at the kinetic energies of 1.25 GeV and 3.5 GeV, based on data measured with HADES. Exclusive channels npπ+ and ppπ0 as well as ppe+e− were studied simultaneously in the framework of a one-boson exchange model. The resonance cross sections were determined from the one-pion channels for Δ(1232 and N(1440 (1.25 GeV as well as further Δ and N* resonances up to 2 GeV/c2 for the 3.5 GeV data. The data at 1.25 GeV energy were also analysed within the framework of the partial wave analysis together with the set of several other measurements at lower energies. The obtained solutions provided the evolution of resonance production with the beam energy, showing a sizeable non-resonant contribution but with still dominating contribution of Δ(1232P33. In the case of 3.5 GeV data, the study of the ppe+e− channel gave the insight on the Dalitz decays of the baryon resonances and, in particular, on the electromagnetic transition form-factors in the time-like region. We show that the assumption of a constant electromagnetic transition form-factors leads to underestimation of the yield in the dielectron invariant mass spectrum below the vector mesons pole. On the other hand, a comparison with various transport models shows the important role of intermediate ρ production, though with a large model dependency. The exclusive channels analysis done by the HADES collaboration provides new stringent restrictions on the parameterizations used in the models.

  17. Investigation of interactions between dendrimer-coated magnetite nanoparticles and bovine serum albumin

    International Nuclear Information System (INIS)

    Pan Bifeng; Gao Feng; Ao Limei

    2005-01-01

    We investigated the interactions between dendrimer-coated magnetite nanoparticles (MNPs) and the protein serum albumin. The investigation was based on the fluorescence quenching of tryptophan residue of serum albumin after binding with the dendrimer-coated magnetite nanoparticles. The extent of the interactions between bovine serum albumin and dendrimer-coated MNPs strongly depends on their surface groups and pH value

  18. Interpretations of education about gene-environment influences on health in rural Ethiopia: the context of a neglected tropical disease.

    Science.gov (United States)

    Tora, Abebayehu; Ayode, Desta; Tadele, Getnet; Farrell, David; Davey, Gail; McBride, Colleen M

    2016-07-01

    Misunderstandings of the role of genetics in disease development are associated with stigmatizing behaviors and fatalistic attitudes about prevention. This report describes an evaluation of community understanding of an educational module about genetic and environmental influences on the development of podoconiosis, a neglected tropical disease endemic in highland Ethiopia. A qualitative process assessment was conducted as part of a large prospective intervention trial in August 2013, in Wolaita Zone, southern Ethiopia. Sixty five participants were purposively selected from 600 households randomized to receive the inherited susceptibility module. The educational module used pictorial representations and oral explanations of the interaction of inherited sensitivity and soil exposure and was delivered by lay health educators in participants' homes. Data were collected using semi-structured individual interviews (IDIs) or focus group discussions (FGDs). Qualitative analyses showed that most participants improved their understanding of inherited soil sensitivity and susceptibility to podoconiosis. Participants linked their new understanding to decreased stigma-related attitudes. The module also corrected misconceptions that the condition was contagious, again diminishing stigmatizing attitudes. Lastly, these improvements in understanding increased the perceived value of foot protection. Taken together, these improvements support the acceptability, feasibility and potential benefits of implementing gene-environment education in low and middle income countries. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

  19. Using Language Games as a Way to Investigate Interactional Engagement in Human-Robot Interaction

    DEFF Research Database (Denmark)

    Jensen, L. C.

    2016-01-01

    how students' engagement with a social robot can be systematically investigated and evaluated. For this purpose, I present a small user study in which a robot plays a word formation game with a human, in which engagement is determined by means of an analysis of the 'language games' played...

  20. Synthesis of PAMAM dendrimers and investigations of their interaction with POPC/POPG lipids

    OpenAIRE

    Gneid, Hassan

    2014-01-01

    PAMAM dendrimers are three dimensional organic polymers synthesised by repetitive steps to achieve a controlled size and shape with a choice of surface functional groups. One of the potential applications of dendrimers is for drug/gene delivery which requires the dendrimer to interact with the cellular membranes. This study is designed to probe the interactions between PAMAM dendrimers and lipid bilayers. To investigate these interactions PAMAM dendrimers up to the third generation were synth...

  1. Investigating Pedagogical Techniques in Classroom Interactions at a CELTA Training Programme

    Science.gov (United States)

    Rahman, Md Shidur

    2016-01-01

    The study investigated the similarities and dissimilarities of using pedagogical techniques in classroom interactions, taken place whilst teaching a known language and an unknown language in a CELTA training classroom context. For this purpose, the classroom interactions in unknown and known languages were analysed according to the qualitative…

  2. Assessing the Effectiveness of Parent-Child Interaction Therapy with Language Delayed Children: A Clinical Investigation

    Science.gov (United States)

    Falkus, Gila; Tilley, Ciara; Thomas, Catherine; Hockey, Hannah; Kennedy, Anna; Arnold, Tina; Thorburn, Blair; Jones, Katie; Patel, Bhavika; Pimenta, Claire; Shah, Rena; Tweedie, Fiona; O'Brien, Felicity; Leahy, Ruth; Pring, Tim

    2016-01-01

    Parent-child interaction therapy (PCIT) is widely used by speech and language therapists to improve the interactions between children with delayed language development and their parents/carers. Despite favourable reports of the therapy from clinicians, little evidence of its effectiveness is available. We investigated the effects of PCIT as…

  3. Investigating the interaction of x-ray free electron laser radiation with grating structure

    NARCIS (Netherlands)

    Gaudin, J.; Ozkan, C.; Chalupsky, J.; Bajt, S.; Burian, T.; Vysin, L.; Coppola, N.; Farahani, S. D.; Chapman, H. N.; Galasso, G.; Hajkova, V.; Harmand, M.; Juha, L.; Jurek, M.; Loch, R. A.; Möller, S.; Nagasono, M.; Stormer, M.; Sinn, H.; Saksl, K.; Sobierajski, R.; Schulz, J.; Sovak, P.; Toleikis, S.; Tiedtke, K.; Tschentscher, T.; Krzywinski, J.

    2012-01-01

    The interaction of free electron laser pulses with grating structure is investigated using 4.6 +/- 0.1 nm radiation at the FLASH facility in Hamburg. For fluences above 63.7 +/- 8.7 mJ/cm(2), the interaction triggers a damage process starting at the edge of the grating structure as evidenced by

  4. Interactivity effects in social media marketing on brand engagement: an investigation of underlying mechanisms

    NARCIS (Netherlands)

    Antheunis, M.L.; van Noort, G.; Eisend, M.; Langner, T.

    2011-01-01

    Although, SNS advertising spending increases, research on SNS campaigning is still underexposed. First, this study aims to investigate the effect of SNS campaign interactivity on the receivers brand engagement, taking four underlying mechanisms into account (brand identification, campaign

  5. Problematic issues of improvement of an interaction between an investigator and other participants of criminal proceedings

    Directory of Open Access Journals (Sweden)

    О. С. Луньова

    2015-05-01

    Full Text Available Problem setting. The article considers features of the interaction between an investigator as a representative of the prosecution and other various participants of criminal proceedings including a head of investigation unit, prosecutor, investigative judge and others. The topicality of raised questions in the current article is confirmed by the fact that previously the interaction between an investigator and other participants of criminal proceedings in pre-trial investigation was conducted in terms of the former Criminal Procedural Code of Ukraine (1960. Recent research and publications analysis. Some of questions regarding the interaction between an investigator and other participants of criminal proceedings in pre-trial investigation were examined by Linovskii V. A, Bandurka A. M., Groshevii Y. M., Larin O. M., Loboika L. M., Pogoretskii M. A., Tatarov O. Y., Sheiffer S. A., Golovko L. V., Baulin O. V., Zelenetskii V. S., Yukhno A. A. and others. Paper objective. The main aim of the article is a research of features of the interaction in current circumstances between an investigator and other participants of criminal proceedings including the head of investigation unit. It concerns as well the research of different scientific views regarding the matter and various ideas about improvement of principal norms in the Criminal Procedural Code of Ukraine and other legal acts that regulate the above-mentioned interaction. Paper main body. During the pre-trial investigation the essential question is the interaction between an investigator and a prosecutor who conducts an oversight in criminal proceedings. The current Criminal Procedural Code of Ukraine greatly expanded the full powers of the prosecutor to oversee the compliance of laws during a pre-trial investigation. Only the prosecutor should conduct a procedural supervision in a pre-trial investigation. We believe this procedural possibility limits an investigation independency. The interaction

  6. Estimating risks and relative risks in case-base studies under the assumptions of gene-environment independence and Hardy-Weinberg equilibrium.

    Directory of Open Access Journals (Sweden)

    Tina Tsz-Ting Chui

    Full Text Available Many diseases result from the interactions between genes and the environment. An efficient method has been proposed for a case-control study to estimate the genetic and environmental main effects and their interactions, which exploits the assumptions of gene-environment independence and Hardy-Weinberg equilibrium. To estimate the absolute and relative risks, one needs to resort to an alternative design: the case-base study. In this paper, the authors show how to analyze a case-base study under the above dual assumptions. This approach is based on a conditional logistic regression of case-counterfactual controls matched data. It can be easily fitted with readily available statistical packages. When the dual assumptions are met, the method is approximately unbiased and has adequate coverage probabilities for confidence intervals. It also results in smaller variances and shorter confidence intervals as compared with a previous method for a case-base study which imposes neither assumption.

  7. Estimating Risks and Relative Risks in Case-Base Studies under the Assumptions of Gene-Environment Independence and Hardy-Weinberg Equilibrium

    Science.gov (United States)

    Chui, Tina Tsz-Ting; Lee, Wen-Chung

    2014-01-01

    Many diseases result from the interactions between genes and the environment. An efficient method has been proposed for a case-control study to estimate the genetic and environmental main effects and their interactions, which exploits the assumptions of gene-environment independence and Hardy-Weinberg equilibrium. To estimate the absolute and relative risks, one needs to resort to an alternative design: the case-base study. In this paper, the authors show how to analyze a case-base study under the above dual assumptions. This approach is based on a conditional logistic regression of case-counterfactual controls matched data. It can be easily fitted with readily available statistical packages. When the dual assumptions are met, the method is approximately unbiased and has adequate coverage probabilities for confidence intervals. It also results in smaller variances and shorter confidence intervals as compared with a previous method for a case-base study which imposes neither assumption. PMID:25137392

  8. Investigating the benefits of a secondary education interaction design thinking course inside and outside the classroom

    NARCIS (Netherlands)

    Aflatoony, L.; Wakkary, R.L.; Neustaedter, C.

    In this study we investigated how an interaction design-thinking course benefited secondary school students in grades 9 and 10. This study investigated the benefits for students within the classroom and unlike previous studies, it also articulated the potential for students to utilize their skills

  9. Investigation of Fanconi anemia protein interactions by yeast two-hybrid analysis.

    Science.gov (United States)

    Huber, P A; Medhurst, A L; Youssoufian, H; Mathew, C G

    2000-02-05

    Fanconi anemia is a chromosomal breakage disorder with eight complementation groups (A-H), and three genes (FANCA, FANCC, and FANCG) have been identified. Initial investigations of the interaction between FANCA and FANCC, principally by co-immunoprecipitation, have proved controversial. We used the yeast two-hybrid assay to test for interactions of the FANCA, FANCC, and FANCG proteins. No activation of the reporter gene was observed in yeast co-expressing FANCA and FANCC as hybrid proteins, suggesting that FANCA does not directly interact with FANCC. However, a high level of activation was found when FANCA was co-expressed with FANCG, indicating strong, direct interaction between these proteins. Both FANCA and FANCG show weak but consistent interaction with themselves, suggesting that their function may involve dimerisation. The site of interaction of FANCG with FANCA was investigated by analysis of 12 mutant fragments of FANCG. Although both N- and C-terminal fragments did interact, binding to FANCA was drastically reduced, suggesting that more than one region of the FANCG protein is required for proper interaction with FANCA. Copyright 2000 Academic Press.

  10. Exploring Interactions in L2 Blogging: Metadiscourse in Philippine Investigative Journalism Blogs

    Directory of Open Access Journals (Sweden)

    Veronico Nogales Tarrayo

    2014-09-01

    Full Text Available Although metadiscourse has been examined in different genres, such as academic papers, newspaper editorials, school textbooks, and the like, still relatively little attention has been given to the discourse of cyber-genres, particularly blogs or weblogs. Using Hyland’s (2005 model, this paper examined the interactive and the interactional metadiscourse in Philippine investigative journalism blogs where English is used as a second language or L2. The corpus analyzed was taken from 20 investigative journalism blogs published in http://pcij.org/blog/, the official website of the Philippine Center for Investigative Journalism (PCIJ blogs. Based on the findings of the study, it can be inferred that there is much evidence in the use of metadiscourse in Philippine investigative journalism blogs; thus, the use of metadiscourse as an appropriate linguistic resource is supplemental and essential. The data revealed that the investigative journalism blogs have a higher frequency of use of interactive resources, allowing writers to organize and structure their propositions so that the text becomes more coherent to the readers. Among the five categories of interactive resources, the use of evidentials has the highest frequency. As regards the use of interactional resources, hedges are the most frequent. The findings of the study likewise provide pedagogical implications for ESL writing.

  11. Investigation of the molecular level interactions between mucins and food proteins: Spectroscopic, tribological and rheological studies

    OpenAIRE

    Celebioglu, Hilal Yilmaz; Chronakis, Ioannis S.; Lee, Seunghwan; Guðjónsdóttir, María

    2017-01-01

    The thesis investigated the structure and molecular-level interaction of β-lactoglobulin (BLG) and mucins, representing major components of the dairy products and saliva/digestion systems, respectively. Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer covers epithelial surfaces throughout the body. A literature review of the interactions of different mucin types and saliva mucins with several food proteins and food protein emulsions, as well as their f...

  12. Exploring Interactions in L2 Blogging: Metadiscourse in Philippine Investigative Journalism Blogs

    OpenAIRE

    Veronico Nogales Tarrayo

    2014-01-01

    Although metadiscourse has been examined in different genres, such as academic papers, newspaper editorials, school textbooks, and the like, still relatively little attention has been given to the discourse of cyber-genres, particularly blogs or weblogs. Using Hyland’s (2005) model, this paper examined the interactive and the interactional metadiscourse in Philippine investigative journalism blogs where English is used as a second language or L2. The corpus analyzed was taken from 20 invest...

  13. Expanding Interaction Potentials within Virtual Environments: Investigating the Usability of Speech and Manual Input Modes for Decoupled Interaction

    Directory of Open Access Journals (Sweden)

    Alex Stedmon

    2011-01-01

    Full Text Available Distributed technologies and ubiquitous computing now support users who may be detached or decoupled from traditional interactions. In order to investigate the potential usability of speech and manual input devices, an evaluation of speech input across different user groups and a usability assessment of independent-user and collaborative-user interactions was conducted. Whilst the primary focus was on a formative usability evaluation, the user group evaluation provided a formal basis to underpin the academic rigor of the exercise. The results illustrate that using a speech interface is important in understanding user acceptance of such technologies. From the usability assessment it was possible to translate interactions and make them compatible with innovative input devices. This approach to interaction is still at an early stage of development, and the potential or validity of this interfacing concept is still under evaluation; however, as a concept demonstrator, the results of these initial evaluations demonstrate the potential usability issues of both input devices as well as highlighting their suitability for advanced virtual applications.

  14. Experimental investigation of the dynamics in a strongly interacting Fermi gas : collective modes and rotational properties

    International Nuclear Information System (INIS)

    Riedl, S.

    2009-01-01

    This thesis explores the dynamics in an ultracold strongly interacting Fermi gas. Therefore we perform measurements on collective excitation modes and rotational properties of the gas. The strongly interacting gas is realized using an optically trapped Fermi gas of 6 Li atoms, where the interactions can be tuned using a broad Feshbach resonance. Our measurements allow to test the equation of state of the gas, study the transition from hydrodynamic to collisionless behavior, reveal almost ideal hydrodynamic behavior in the nonsuperfluid phase, investigate the lifetime of angular momentum, and show superfluidity through the quenching of the moment of inertia. (author)

  15. Numerical Investigation of Ultrafast interaction between THz Fields and Crystalline Materials

    DEFF Research Database (Denmark)

    Pedersen, Pernille Klarskov; Clark, Stewart J.; Jepsen, Peter Uhd

    2014-01-01

    We present a quantum - mechanical molecular dynamics investigation of the interaction between strong single - cyc le THz pulses and ionic crystals . We find nonlinearities in the response of the CsI crystals at field strengths higher than 10 MV/cm.......We present a quantum - mechanical molecular dynamics investigation of the interaction between strong single - cyc le THz pulses and ionic crystals . We find nonlinearities in the response of the CsI crystals at field strengths higher than 10 MV/cm....

  16. Video elicitation interviews: a qualitative research method for investigating physician-patient interactions.

    Science.gov (United States)

    Henry, Stephen G; Fetters, Michael D

    2012-01-01

    We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants' associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care.

  17. Video Elicitation Interviews: A Qualitative Research Method for Investigating Physician-Patient Interactions

    Science.gov (United States)

    Henry, Stephen G.; Fetters, Michael D.

    2012-01-01

    We describe the concept and method of video elicitation interviews and provide practical guidance for primary care researchers who want to use this qualitative method to investigate physician-patient interactions. During video elicitation interviews, researchers interview patients or physicians about a recent clinical interaction using a video recording of that interaction as an elicitation tool. Video elicitation is useful because it allows researchers to integrate data about the content of physician-patient interactions gained from video recordings with data about participants’ associated thoughts, beliefs, and emotions gained from elicitation interviews. This method also facilitates investigation of specific events or moments during interactions. Video elicitation interviews are logistically demanding and time consuming, and they should be reserved for research questions that cannot be fully addressed using either standard interviews or video recordings in isolation. As many components of primary care fall into this category, high-quality video elicitation interviews can be an important method for understanding and improving physician-patient interactions in primary care. PMID:22412003

  18. Investigation on the interaction of catalase with sodium lauryl sulfonate and the underlying mechanisms.

    Science.gov (United States)

    Wang, Jing; Jia, Rui; Wang, Jiaxi; Sun, Zhiqiang; Wu, Zitao; Liu, Rutao; Zong, Wansong

    2018-02-01

    As a classic type of anionic surfactants, sodium lauryl sulfonate (SLS) might change the structure and function of antioxidant enzyme catalase (CAT) through their direct interactions. However, the underlying molecular mechanism is still unknown. This study investigated the direct interaction of SLS with CAT molecule and the underlying mechanisms using multi-spectroscopic methods, isothermal titration calorimetry, and molecular docking studies. No obvious effects were observed on CAT structure and activity under low SLS concentration exposure. The particle size of CAT molecule decreased and CAT activity was slightly inhibited under high SLS concentration exposure. SLS prefers to bind to the interface of CAT mainly via van der Waals' forces and hydrogen bonds. Subsequently, SLS interacts with the amino acid residues around the heme groups of CAT via hydrophobic interactions and might inhibit CAT activity. © 2017 Wiley Periodicals, Inc.

  19. Investigation on human serum albumin and Gum Tragacanth interactions using experimental and computational methods.

    Science.gov (United States)

    Moradi, Sajad; Taran, Mojtaba; Shahlaei, Mohsen

    2018-02-01

    The study on the interaction of human serum albumin and Gum Tragacanth, a biodegradable bio-polymer, has been undertaken. For this purpose, several experimental and computational methods were used. Investigation of thermodynamic parameters and mode of interactions were carried out using Fluorescence spectroscopy in 300 and 310K. Also, a Fourier transformed infrared spectra and synchronous fluorescence spectroscopy was performed. To give detailed insight of possible interactions, docking and molecular dynamic simulations were also applied. Results show that the interaction is based on hydrogen bonding and van der Waals forces. Structural analysis implies on no adverse change in protein conformation during binding of GT. Furthermore, computational methods confirm some evidence on secondary structure enhancement of protein as a presence of combining with Gum Tragacanth. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Forms of memory: Investigating the computational basis of semantic-episodic memory interactions

    NARCIS (Netherlands)

    Neville, D.A.

    2015-01-01

    The present thesis investigated how the memory systems related to the processing of semantic and episodic information combine to generate behavioural performance as measured in standard laboratory tasks. Across a series of behavioural experiment I looked at different types of interactions between

  1. Guess who? An interactive and entertaining game-like platform for investigating human emotions

    NARCIS (Netherlands)

    Ahmad, M.I.; Tariq, H.; Saeed, M.; Shahid, S.; Krahmer, E.J.

    2011-01-01

    In this paper, we discuss the design and the development of a highly customizable interactive platform ‘Guess Who’, which was designed as a tool for investigating human emotions in a variety of experimental setups. In its essence, ‘Guess Who?’ is actually a game, which includes typical game elements

  2. An Investigation of Interactive, Dialogue-Based Instruction for Undergraduate Art History

    Science.gov (United States)

    Gioffre, Penelope

    2012-01-01

    This paper explores the feasibility and efficacy of incorporating an interactive, discussion-based instructional approach into an undergraduate art history survey course and investigates effects of the new pedagogic strategy on students' demonstrated comprehension and retention of required content. The action research project follows a systematic…

  3. Bridge-in-a-Backpack(TM) task 3.1: investigating soil - structure interaction - experimental design.

    Science.gov (United States)

    2015-07-01

    This report includes fulfillment of Task 3.1 of a multi-task contract to further enhance concrete filled FRP tubes, or : the Bridge in a Backpack. Task 3 is an investigation of soil-structure interaction for the FRP tubes. Task 3.1 is the : design of...

  4. Predicting wind farm wake interaction with RANS: an investigation of the Coriolis force

    DEFF Research Database (Denmark)

    van der Laan, Paul; Hansen, Kurt Schaldemose; Sørensen, Niels N.

    2015-01-01

    A Reynolds-averaged Navier-Stokes code is used to simulate the interaction of two neighboring wind farms. The influence of the Coriolis force is investigated by modeling the atmospheric surface/boundary layer with three different methodologies. The results show that the Coriolis force is negligible...

  5. Subspace in Linear Algebra: Investigating Students' Concept Images and Interactions with the Formal Definition

    Science.gov (United States)

    Wawro, Megan; Sweeney, George F.; Rabin, Jeffrey M.

    2011-01-01

    This paper reports on a study investigating students' ways of conceptualizing key ideas in linear algebra, with the particular results presented here focusing on student interactions with the notion of subspace. In interviews conducted with eight undergraduates, we found students' initial descriptions of subspace often varied substantially from…

  6. Links between Friends' Physical Aggression and Adolescents' Physical Aggression: What Happens If Gene-Environment Correlations are Controlled?

    Science.gov (United States)

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

    2016-01-01

    Exposure to deviant friends has been found to be a powerful source of influence on children's and adolescents' aggressive behavior. However, the contribution of deviant friends may have been overestimated because of a possible non-accounted gene-environment correlation (rGE). In this study, we used a cross-lagged design to test whether friends'…

  7. The paradox of intelligence: Heritability and malleability coexist in hidden gene-environment interplay.

    Science.gov (United States)

    Sauce, Bruno; Matzel, Louis D

    2018-01-01

    Intelligence can have an extremely high heritability, but also be malleable; a paradox that has been the source of continuous controversy. Here we attempt to clarify the issue, and advance a frequently overlooked solution to the paradox: Intelligence is a trait with unusual properties that create a large reservoir of hidden gene-environment (GE) networks, allowing for the contribution of high genetic and environmental influences on individual differences in IQ. GE interplay is difficult to specify with current methods, and is underestimated in standard metrics of heritability (thus inflating estimates of "genetic" effects). We describe empirical evidence for GE interplay in intelligence, with malleability existing on top of heritability. The evidence covers cognitive gains consequent to adoption/immigration, changes in IQ's heritability across life span and socioeconomic status, gains in IQ over time consequent to societal development (the Flynn effect), the slowdown of age-related cognitive decline, and the gains in intelligence from early education. The GE solution has novel implications for enduring problems, including our inability to identify intelligence-related genes (also known as IQ's "missing heritability"), and the loss of initial benefits from early intervention programs (such as "Head Start"). The GE solution can be a powerful guide to future research, and may also aid policies to overcome barriers to the development of intelligence, particularly in impoverished and underprivileged populations. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  8. Gene-Environment Interplay in Internalizing Disorders: Consistent Findings across Six Environmental Risk Factors

    Science.gov (United States)

    Hicks, Brian M.; DiRago, Ana C.; Iacono, William G.; McGue, Matt

    2009-01-01

    Background Newer behavior genetic methods can better elucidate gene-environment (G-E) interplay in the development of internalizing (INT) disorders (i.e., major depression and anxiety disorders). However, no study to date has conducted a comprehensive analysis examining multiple environmental risks with the purpose of delineating how general G-E mechanisms influence the development of INT disorders. Methods The sample consisted of 1315 male and female twin pairs participating in the age 17 assessment of the Minnesota Twin Family Study. Quantitative G-E interplay models were used to examine how genetic and environmental risk for INT disorders changes as a function of environmental context. Multiple measures and informants were employed to construct composite measures of INT disorders and 6 environmental risk factors including: stressful life events, mother-child and father-child relationship problems, antisocial and prosocial peer affiliation, and academic achievement and engagement. Results Significant moderation effects were detected between each environmental risk factor and INT such that in the context of greater environmental adversity, nonshared environmental factors became more important in the etiology of INT symptoms. Conclusion Our results are consistent with the interpretation that environmental stressors have a causative effect on the emergence of INT disorders. The consistency of our results suggests a general mechanism of environmental influence on INT disorders regardless of the specific form of environmental risk. PMID:19594836

  9. An investigation of chitosan and sodium dodecyl sulfate interactions in acetic media

    Directory of Open Access Journals (Sweden)

    Petrović Lidija B.

    2016-01-01

    Full Text Available Polymer/surfactant association is a cooperative phenomenon where surfactant binds to the polymer in the form of aggregates, usually through electrostatic or hydrophobic forces. As already known, polyelectrolytes may interact with oppositely charged surfactants through electrostatic attraction that results in polymer/surfactant complex formation. This behavior could be desirable in wide range of application of polymer/surfactant mixtures, such as improving colloid stability, gelling, emulsification and microencapsulation. In the present study surface tension, turbidity, viscosity and electrophoretic mobility measurements were used to investigate interactions of cationic polyelectrolyte chitosan (Ch and oppositely charged anionic surfactant, sodium dodecyl sulfate (SDS, in buffered water. Obtained results show the presence of interactions that lead to Ch/SDS complexes formation at all investigated pH and for all investigated polymer concentrations. Mechanisms of interaction, as well as characteristics of formed Ch/SDS complexes, are highly dependent on their mass ratio in the mixtures, while pH has no significant influence. [Projekat Ministarstva nauke Republike Srbije, br. II46010

  10. Investigation of Interactions between Thrombin and Ten Phenolic Compounds by Affinity Capillary Electrophoresis and Molecular Docking

    Directory of Open Access Journals (Sweden)

    Qiao-Qiao Li

    2018-01-01

    Full Text Available Thrombin plays a vital role in blood coagulation, which is a key process involved in thrombosis by promoting platelet aggregation and converting fibrinogen to form the fibrin clot. In the receptor concept, drugs produce their therapeutic effects via interactions with the targets. Therefore, investigation of interaction between thrombin and small molecules is important to find out the potential thrombin inhibitor. In this study, affinity capillary electrophoresis (ACE and in silico molecular docking methods were developed to study the interaction between thrombin and ten phenolic compounds (p-hydroxybenzoic acid, protocatechuic acid, vanillic acid, gallic acid, catechin, epicatechin, dihydroquercetin, naringenin, apigenin, and baicalein. The ACE results showed that gallic acids and six flavonoid compounds had relative strong interactions with thrombin. In addition, the docking results indicated that all of optimal conformations of the six flavonoid compounds were positioned into the thrombin activity centre and had interaction with the HIS57 or SER195 which was the key residue to bind thrombin inhibitors such as argatroban. Herein, these six flavonoid compounds might have the potential of thrombin inhibition activity. In addition, the developed method in this study can be further applied to study the interactions of other molecules with thrombin.

  11. Numerical investigations on interactions between tangles of quantized vortices and second sound

    International Nuclear Information System (INIS)

    Penz, H.; Aarts, R.; de Waele, F.

    1995-01-01

    The reconnecting vortex-tangle model is used to investigate the interaction of tangles of quantized vortices with second sound. This interaction can be expressed in terms of an effective line-length density, which depends on the direction of the second-sound wave. By comparing the effective line-length densities in various directions the tangle structure can be examined. Simulations were done for flow channels with square and circular cross sections as well as for slits. The results show that in all these cases the tangles are inhomogeneous in direction as well as in space. The calculated inhomogeneities are in agreement with experiment

  12. Preliminary investigation of the interaction between radiologists and digital radiologic work stations

    International Nuclear Information System (INIS)

    Fajardo, L.L.; McNeill, K.M.; Maloney, K.; Mockbee, B.

    1987-01-01

    Using a work station built in the authors' department, they conducted an investigation into the interaction between radiologist and a digital radiologic work station. A survey provided information regarding the experience of 18 radiologists with digital technology and their expectations of its benefits. They ranked the potential attributes of digital work stations, with spatial resolution first, followed by contrast resolution, ease of use, speed, ease of learning, and cost. Observation of the radiologists' interaction with the work station has provided recommendations for implementation of functions. The authors conclude that radiologic work station user interfaces must be intuitive and support the radiologist's task without increasing the time or effort required for the task

  13. Investigation of magnetic interactions in sulfides by means of magnetic resonance

    International Nuclear Information System (INIS)

    Veen, G. van.

    1978-01-01

    Investigations have been designed to gather more information about magnetic pair interactions in sulfides by isomorphic substitution of the magnetic ions in suitable chosen diamagnetic host lattices and measurement of electron spin resonance of coupled pairs and of electron spin resonance or electron nuclear double resonance of the hyperfine interaction due to the nuclei of diamagnetic cations. The greater part of this thesis is devoted to preliminaries of magnetic resonance interpretation and sample selection and preparation. The measurements on the magnetically diluted compounds, which are described, only have an exploratory nature. (Auth.)

  14. A differential vapor-pressure equipment for investigations of biopolymer interactions

    DEFF Research Database (Denmark)

    Andersen, Kim B; Koga, Y.; Westh, Peter

    2002-01-01

    the use of high-accuracy capacitance manometers and a leak-tight system of stainless steel pipes, below-scaled valves and metal-gasket fittings, DeltaP can be measured with a resolution of about 0.5 mubar (0.05 Pa) in some applications. This sensitivity level, along with other features of the equipment......, particularly a "gas-phase titration" routine for changing the cell composition, makes it effective for the investigations of several types of biopolymer interactions. These include isothermal studies of net affinities such as the adsorption of water to proteins or membranes, the preferential interaction...

  15. In vitro and in silico investigations of the binding interactions between chlorophenols and trypsin

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan-Qing, E-mail: wyqing76@126.com [Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City 224002, Jiangsu Province (China); Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City 224002, Jiangsu Province (China); Tan, Chun-Yun [Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City 224002, Jiangsu Province (China); Zhuang, Shu-Lin [Institute of Environmental Science, College of Environmental and Resource Science, Zhejiang University, Hangzhou 310058 (China); Zhai, Peng-Zhan; Cui, Yun; Zhou, Qiu-Hua; Zhang, Hong-Mei [Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City 224002, Jiangsu Province (China); Fei, Zhenghao [Jiangsu Provincial Key Laboratory of Coastal Wetland Bioresources and Environmental Protection, Yancheng City 224002, Jiangsu Province (China); Institute of Applied Chemistry and Environmental Engineering, Yancheng Teachers University, Yancheng City 224002, Jiangsu Province (China)

    2014-08-15

    Graphical abstract: - Highlights: • Binding interactions of five chlorophenols with trypsin were investigated. • The number of chlorine atoms of chlorophenols partly affected the binding ability of them to trypsin. • Noncovalent interactions stabilized the trypsin–chlorophenols complexes. • There was the one main binding site of trypsin for chlorophenols. - Abstract: Being the first-degree toxic pollutants, chlorophenols (CP) have potential carcinogenic and mutagenic activity and toxicity. Since there still lacks studies on molecular interactions of chlorophenols with trypsin, one major binding target of many exogenous environmental pollutants, the binding interactions between five chlorophenols, 2-CP, 2,6-DCP, 2,4,6-TCP, 2,4,6-TCP, 2,3,4,6-TCP and PCP and trypsin were characterized by the combination of multispectroscopic techniques and molecular modeling. The chlorophenols bind at the one main site of trypsin and the binding induces the changes of microenvironment and global conformations of trypsin. Different number of chloride atoms significantly affects the binding and the binding constants K{sub A} ranks as K{sub A} (2-CP) < K{sub A} (2,6-DCP) ≈ K{sub A} (2,4,6-TCP) < K{sub A} (2,3,4,6-TCP) < K{sub A} (PCP). These chlorophenols interacts with trypsin mainly through hydrophobic interactions and via hydrogen bonding interactions and aromatic–aromatic π–π stacking interaction. Our results offer insights into the binding mechanism of chlorophenols with trypsin and provide important information for possible toxicity risk of chlorophenols to human health.

  16. Interaction of albumins and heparinoids investigated by affinity capillary electrophoresis and free flow electrophoresis.

    Science.gov (United States)

    Mozafari, Mona; El Deeb, Sami; Krull, Friederike; Wildgruber, Robert; Weber, Gerhard; Reiter, Christian G; Wätzig, Hermann

    2018-02-01

    A fast and precise affinity capillary electrophoresis (ACE) method has been applied to investigate the interactions between two serum albumins (HSA and BSA) and heparinoids. Furthermore, different free flow electrophoresis methods were developed to separate the species which appears owing to interaction of albumins with pentosan polysulfate sodium (PPS) under different experimental conditions. For ACE experiments, the normalized mobility ratios (∆R/R f ), which provided information about the binding strength and the overall charge of the protein-ligand complex, were used to evaluate the binding affinities. ACE experiments were performed at two different temperatures (23 and 37°C). Both BSA and HSA interact more strongly with PPS than with unfractionated and low molecular weight heparins. For PPS, the interactions can already be observed at low mg/L concentrations (3 mg/L), and saturation is already obtained at approximately 20 mg/L. Unfractionated heparin showed almost no interactions with BSA at 23°C, but weak interactions at 37°C at higher heparin concentrations. The additional signals also appeared at higher concentrations at 37°C. Nevertheless, in most cases the binding data were similar at both temperatures. Furthermore, HSA showed a characteristic splitting in two peaks especially after interacting with PPS, which is probably attributable to the formation of two species or conformational change of HSA after interacting with PPS. The free flow electrophoresis methods have confirmed and completed the ACE experiments. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Investigation of the molecular level interactions between mucins and food proteins: Spectroscopic, tribological and rheological studies

    DEFF Research Database (Denmark)

    Celebioglu, Hilal Yilmaz

    The thesis investigated the structure and molecular-level interaction of β-lactoglobulin (BLG) and mucins, representing major components of the dairy products and saliva/digestion systems, respectively. Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer covers...... epithelial surfaces throughout the body. A literature review of the interactions of different mucin types and saliva mucins with several food proteins and food protein emulsions, as well as their functional properties related to the food oral processing is presented at the first chapter of the thesis (Paper...... V). Most of the studies suggest an electrostatic attraction between positively charged food proteins with negatively charged moieties of mucins (mainly on glycosylated region of mucins). The structural changes occurring during the interaction between BLG, the major whey protein, and bovine...

  18. Investigating conversational dynamics: Interactive alignment, Interpersonal synergy, and collective task performance

    DEFF Research Database (Denmark)

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between...... and their impact on collective performance in a corpus of task-oriented conversations. The results show statistical presence of patterns relevant for both approaches. However, synergetic aspects of dialog provide the best statistical predictors of collective performance and adding aspects of the alignment approach...... does not improve the model. This suggests that structural organization at the level of the interaction plays a crucial role in task-oriented conversations, possibly constraining and integrating processes related to alignment....

  19. A pulse radiolysis investigation of the interactions of drugs and dyes with macromolecules and ribosomes

    International Nuclear Information System (INIS)

    Phillips, G.O.; Power, D.M.; Davies, J.V.

    1975-01-01

    The reactions of hydrated electrons produced during pulse radiolysis have been utilized to investigate the binding of eleven penicillins and four cephalosporins to bovine serum albumin. A primary binding site exists in the serum albumin molecule, which results indicate to be a hydrophobic cleft in the surface of the molecule separated by a distance > 0.5 mm from a cationic amino acid residue, probably lysine. Interaction of drugs with this binding site leads to a conformational change in the protein resulting in a decrease in reactivity towards hydrated electrons. Interaction of cephalosporin C and 6-amino penicillanic acid with serum albumin involves another site which consists of a cationic amino acid residue separted from anionic residue by a distance >0.7nm. Drug binding at this site induces a conformational change in serum albumin leading to greatly increased reactivity towards hydrated electrons. This increase is associated with an increased availability of disulphide bridges. Cephalosporin C also binds hydrophobically to serum a;lbumin resulting in a decrease in reactivity towards esub(aq)sup(-); such binding can be prevented by palmitic acid. Recent data clearly indicate that the pulse radiolysis technique can be further extended to investigate the nature of the interactions of bacterial ribosome suspensions with amino-acridines. Ion binding between benzoflavine and ribosomes has been examined over a wide temperature range and the thermodynamic parameters governing the interaction have been evaluated. (author)

  20. An Exploratory Investigation into the Effects of Adaptation in Child-Robot Interaction

    Science.gov (United States)

    Salter, Tamie; Michaud, François; Létourneau, Dominic

    The work presented in this paper describes an exploratory investigation into the potential effects of a robot exhibiting an adaptive behaviour in reaction to a child’s interaction. In our laboratory we develop robotic devices for a diverse range of children that differ in age, gender and ability, which includes children that are diagnosed with cognitive difficulties. As all children vary in their personalities and styles of interaction, it would follow that adaptation could bring many benefits. In this abstract we give our initial examination of a series of trials which explore the effects of a fully autonomous rolling robot exhibiting adaptation (through changes in motion and sound) compared to it exhibiting pre-programmed behaviours. We investigate sensor readings on-board the robot that record the level of ‘interaction’ that the robot receives when a child plays with it and also we discuss the results from analysing video footage looking at the social aspect of the trial.

  1. Numerical Investigation on Vortex-Structure Interaction Generating Aerodynamic Noises for Rod-Airfoil Models

    Directory of Open Access Journals (Sweden)

    FeiFei Liu

    2017-01-01

    Full Text Available In past several decades, vortex-structure interaction generated aerodynamic noise became one of the main concerns in aircraft design. In order to understand the mechanism, the acoustic analogy method combined with the RANS-based nonlinear acoustics solver (NLAS is investigated. The numerical method is firstly evaluated by the experiment data of the classic rod-airfoil model. Compared with the traditional analogy methods, the RANS/NLAS can capture the nonlinear aerodynamic noise more accurately with lower gird requirements. Then different rod-airfoil configurations were simulated to investigate the aeroacoustic interaction effects. The numerical results are in good agreement with those of the earlier experimental research. It is found that the vortex-shedding crash to the airfoil is the main reason for the noise generation which is dependent on the configurations, distance, and flow conditions.

  2. Investigating the Interaction of Water Vapour with Aminopropyl Groups on the Surface of Mesoporous Silica Nanoparticles.

    Science.gov (United States)

    Paul, Geo; Musso, Giorgia Elena; Bottinelli, Emanuela; Cossi, Maurizio; Marchese, Leonardo; Berlier, Gloria

    2017-04-05

    The interaction of water molecules with the surface of hybrid silica-based mesoporous materials is studied by 29 Si, 1 H and 13 C solid-state NMR and IR spectroscopy, with the support of ab initio calculations. The surface of aminopropyl-grafted mesoporous silica nanoparticles is studied in the dehydrated state and upon interaction with controlled doses of water vapour. Former investigations described the interactions between aminopropyl and residual SiOH groups; the present study shows the presence of hydrogen-bonded species (SiOH to NH 2 ) and weakly interacting "free" aminopropyl chains with restricted mobility, together with a small amount of protonated NH 3 + groups. The concentration of the last-named species increased upon interaction with water, and this indicates reversible and fast proton exchange from water molecules to a fraction of the amino groups. Herein, this is discussed and explained for the first time, by a combination of experimental and theoretical approaches. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Effect modification, interaction and mediation: an overview of theoretical insights for clinical investigators

    Directory of Open Access Journals (Sweden)

    Corraini P

    2017-06-01

    Full Text Available Priscila Corraini,1 Morten Olsen,1 Lars Pedersen,1 Olaf M Dekkers,1,2 Jan P Vandenbroucke1–3 1Department of Clinical Epidemiology, Institute of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark; 2Leiden University Medical Center, Leiden, the Netherlands; 3Department of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK Abstract: We revisited the three interrelated epidemiological concepts of effect modification, interaction and mediation for clinical investigators and examined their applicability when using research databases. The standard methods that are available to assess interaction, effect modification and mediation are explained and exemplified. For each concept, we first give a simple “best-case” example from a randomized controlled trial, followed by a structurally similar example from an observational study using research databases. Our explanation of the examples is based on recent theoretical developments and insights in the context of large health care databases. Terminology is sometimes ambiguous for what constitutes effect modification and interaction. The strong assumptions underlying the assessment of interaction, and particularly mediation, require clinicians and epidemiologists to take extra care when conducting observational studies in the context of health care databases. These strong assumptions may limit the applicability of interaction and mediation assessments, at least until the biases and limitations of these assessments when using large research databases are clarified. Keywords: methods, epidemiology, effect modifiers, stratified analyses, health care administrative claims

  4. An investigation of the interaction between autobiographical memory and narrative practices

    OpenAIRE

    Edouard, Sherlande; Kurczek, Jake

    2016-01-01

    Edouard, S., & Kurczek, J. (2016, April). An investigation of the interaction between autobiographical memory and narrative practices. Poster Presentation at the 31st Annual LVAIC Undergraduate Psychology Conference. Bethlehem, PA. •  Autobiographical memories are at the interface of memory and narrative capacities, however in the memory literature there is a debate surrounding how much these capacities contribute to autobiographical and general narrative prac...

  5. Investigating the Role of Large-Scale Domain Dynamics in Protein-Protein Interactions.

    Science.gov (United States)

    Delaforge, Elise; Milles, Sigrid; Huang, Jie-Rong; Bouvier, Denis; Jensen, Malene Ringkjøbing; Sattler, Michael; Hart, Darren J; Blackledge, Martin

    2016-01-01

    Intrinsically disordered linkers provide multi-domain proteins with degrees of conformational freedom that are often essential for function. These highly dynamic assemblies represent a significant fraction of all proteomes, and deciphering the physical basis of their interactions represents a considerable challenge. Here we describe the difficulties associated with mapping the large-scale domain dynamics and describe two recent examples where solution state methods, in particular NMR spectroscopy, are used to investigate conformational exchange on very different timescales.

  6. Investigating the Role of Large-Scale Domain Dynamics in Protein-Protein Interactions

    Directory of Open Access Journals (Sweden)

    Elise Delaforge

    2016-09-01

    Full Text Available Intrinsically disordered linkers provide multi-domain proteins with degrees of conformational freedom that are often essential for function. These highly dynamic assemblies represent a significant fraction of all proteomes, and deciphering the physical basis of their interactions represents a considerable challenge. Here we describe the difficulties associated with mapping the large-scale domain dynamics and describe two recent examples where solution state methods, in particular NMR spectroscopy, are used to investigate conformational exchange on very different timescales.

  7. Investigation of the interaction of 85Kr with plants in model experiments

    International Nuclear Information System (INIS)

    Butkus, D.V.; Morkunas, G.S.; Bluvshtejn, D.Yu.; Styro, B.I.

    1988-01-01

    The method of investigation of the interaction of 85 Kr with plants is described using model experiments and data analysis. The dependencies of the coefficient of 85 Kr absorption by plants on the biological structure of the plant, the concentration of krypton-85 in the environment, the method of plant exposition in the environment with the 85 Kr admixture are provided. The time dependencies of 85 Kr desorption from plants are given. 4 refs.; 7 figs.; 3 tabs

  8. A detailed aerosol mixing state model for investigating interactions between mixing state, semivolatile partitioning, and coagulation

    OpenAIRE

    J. Lu; F. M. Bowman

    2010-01-01

    A new method for describing externally mixed particles, the Detailed Aerosol Mixing State (DAMS) representation, is presented in this study. This novel method classifies aerosols by both composition and size, using a user-specified mixing criterion to define boundaries between compositional populations. Interactions between aerosol mixing state, semivolatile partitioning, and coagulation are investigated with a Lagrangian box model that incorporates the DAMS approach. Model results predict th...

  9. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    OpenAIRE

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-01-01

    The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/supe...

  10. Numerical investigations of wake interactions of two wind turbines in tandem

    Science.gov (United States)

    Qian, Yaoru; Wang, Tongguang

    2018-05-01

    Aerodynamic performance and wake interactions between two wind turbine models under different layouts are investigated numerically using large eddy simulation in conjunction with actuator line method based on the “Blind Test” series wind tunnel experiments from Norwegian University of Science and Technology. Numerical results of the power and thrust coefficients of the two rotors and wake characteristics are in good agreement with the experimental measurements. Extended investigations emphasizing the influence of different layout arrangements on the downstream rotor performance and wake development are conducted. Results show that layout arrangements have great influence on the power and thrust prediction of the downstream turbine.

  11. Photophysical and computational investigation of the intermolecular interactions of pyrene with phenothiazine and promazine

    Energy Technology Data Exchange (ETDEWEB)

    Güloğlu, Pınar; Acar, Nursel, E-mail: nursel.acar@ege.edu.tr

    2016-10-20

    Highlights: • Intermolecular interactions of pyrene with phenothiazine/promazine were investigated. • All investigated systems were optimized at ωB97XD/6-31G(d,p) level in gas phase. • The electronic transitions were determined using frontier orbitals. • Both Py–Pheno and Py–Prom are potential candidates for charge transfer systems. - Abstract: The intermolecular interactions between the pyrene (Py) (as acceptor) and phenothiazine (Pheno), promazine (Prom) (as donors) were investigated using UV/Vis absorption and fluorescence spectroscopy. Fluorescence quenching rate constants for Py–Pheno and Py–Prom systems have been calculated approximately 10{sup 10} M{sup −1} s{sup −1}, indicating diffusion controlled processes. A computational investigation has also been carried out in gas phase at ωB97XD/6-31G(d,p) level. Time-dependent density functional theory (TDDFT) was used to calculate the electronic transitions of molecules at B3LYP/6-311++G(d,p) level. Total electronic energies, complexation energies, free energy differences, excitation wavelengths, and HOMO–LUMO energy gaps are discussed in gas phase. Analyses of first excited singlet states have indicated charge transfers transitions between Py and Pheno, Prom through π–π stacking in gas phase at 433 nm and 466 nm, respectively. Due to its charge transfer character, Py–Pheno and Py–Prom systems seem to be appropriate models to investigate and design photosensitive materials.

  12. Intermolecular interactions between σ- and π-holes of bromopentafluorobenzene and pyridine: computational and experimental investigations.

    Science.gov (United States)

    Yang, Fang-Ling; Yang, Xing; Wu, Rui-Zhi; Yan, Chao-Xian; Yang, Fan; Ye, Weichun; Zhang, Liang-Wei; Zhou, Pan-Pan

    2018-04-25

    The characters of σ- and π-holes of bromopentafluorobenzene (C6F5Br) enable it to interact with an electron-rich atom or group like pyridine which possesses an electron lone-pair N atom and a π ring. Theoretical studies of intermolecular interactions between C6F5Br and C5H5N have been carried out at the M06-2X/aug-cc-pVDZ level without and with the counterpoise method, together with single point calculations at M06-2X/TZVP, wB97-XD/aug-cc-pVDZ and CCSD(T)/aug-cc-pVDZ levels. The σ- and π-holes of C6F5Br exhibiting positive electrostatic potentials make these sites favorably interact with the N atom and the π ring of C5H5N with negative electrostatic potentials, leading to five different dimers connected by a σ-holen bond, a σ-holeπ bond or a π-holeπ bond. Their geometrical structures, characteristics, nature and spectroscopy behaviors were systematically investigated. EDA analyses reveal that the driving forces in these dimers are different. NCI, QTAIM and NBO analyses confirm the existence of intermolecular interactions formed via σ- and π-holes of C6F5Br and the N atom and the π ring of C5H5N. The experimental IR and Raman spectra gave us important information about the formation of molecular complexes between C6F5Br and C5H5N. We expect that the results could provide valuable insights into the investigation of intermolecular interactions involving σ- and π-holes.

  13. Combined fluorescence and electrochemical investigation on the binding interaction between organic acid and human serum albumin

    Institute of Scientific and Technical Information of China (English)

    CHEN Yan-Min; GUO Liang-Hong

    2009-01-01

    Human serum albumin (HSA) is a plasma protein responsible for the binding and transport of fatty acids and a variety of exogenous chemicals such as drugs and environmental pollutants. Such binding plays a crucial role in determining the ADME (absorption, distribution, metabolism, and excretion) and bioavailability of the pollutants. We report investigation on the binding interaction between HSA and acetic acid (C2), octanoic acid (C8) and dodecanoic acid (C12) by the combination of site-specific fluorescent probe, tryptophan intrinsic fluorescence and tyrosine electrochemistry. Two fluorescent probes, dansylamide and dansyl-L-proline, were employed in the displacement measurement to study fatty acid interaction with the two drug-binding sites on HSA. Intrinsic fluorescence of tryptophan in HSA was monitored upon addition of the fatty acids into HSA. Electrocatalyzed response of the tyrosine residues in HSA by a redox mediator was used to investigate the binding interaction. Qualitatively, observations made by the three approaches are very similar. HSA did not show any change in either fluorescence or electrochemistry after mixing with C2, suggesting there is no significant interaction with the short-chain fatty acid. For C8, the measured signal dropped in a single-exponential fashion, indicative of independent and non-cooperative binding. The calculated association constant and binding ratio is 3.1×106 L/mol and 1 with drug binding Site I, 1.1×107 L/mol and 1 with Site II, and 7.0×104 L/mol and 4 with the tryptophan site. The measurement with C12 displayed multiple phases of fluorescence change, suggesting cooperativity and allosteric effect of C12 binding. These results correlate well with those obtained by the established methods, and validate the new approach as a viable tool to study the interactions of environmental pollutants with biological molecules.

  14. Atomic force imaging microscopy investigation of the interaction of ultraviolet radiation with collagen thin films

    Science.gov (United States)

    Stylianou, A.; Yova, D.; Alexandratou, E.; Petri, A.

    2013-02-01

    Collagen is the major fibrous protein in the extracellular matrix and consists a significant component of skin, bone, cartilage and tendon. Due to its unique properties, it has been widely used as scaffold or culture substrate for tissue regeneration or/and cell-substrate interaction studies. The ultraviolet light-collagen interaction investigations are crucial for the improvement of many applications such as that of the UV irradiation in the field of biomaterials, as sterilizing and photo-cross-linking method. The aim of this paper was to investigate the mechanisms of UV-collagen interactions by developing a collagen-based, well characterized, surface with controlled topography of collagen thin films in the nanoscale range. The methodology was to quantify the collagen surface modification induced on ultraviolet radiation and correlate it with changes induced in cells. Surface nanoscale characterization was performed by Atomic Force Microscopy (AFM) which is a powerful tool and offers quantitative and qualitative information with a non-destructive manner. In order to investigate cells behavior, the irradiated films were used for in vitro cultivation of human skin fibroblasts and the cells morphology, migration and alignment were assessed with fluorescence microscopy imaging and image processing methods. The clarification of the effects of UV light on collagen thin films and the way of cells behavior to the different modifications that UV induced to the collagen-based surfaces will contribute to the better understanding of cell-matrix interactions in the nanoscale and will assist the appropriate use of UV light for developing biomaterials.

  15. Quantum chemical investigation of attractive non-covalent interactions between halomethanes and rare gases.

    Science.gov (United States)

    McAllister, Linda J; Bruce, Duncan W; Karadakov, Peter B

    2012-11-01

    The interaction between rare gas atoms and trifluoromethylhalides and iodomethane is investigated using ab initio and density functional theory (DFT) methods: MP2, CCSD, B3LYP, M06, M06-L, M06-2X, M06-HF, X3LYP, PBE, B97-D, B3LYP-D3, and M06-L-D3, in combination with the aug-cc-pVTZ and aug-cc-pVTZ-PP basis sets. A weakly attractive interaction is observed for all complexes, whose strength increases as the rare gas and halogen bond donor become more polarizable, and as the group bound to the halogen bond donor becomes more electron-withdrawing. The separation between iodine and krypton in the complex CF(3)I···Kr, calculated at the MP2 and B3LYP-D3 levels of theory, agrees very well with recent experimental results (Stephens, S. L.; Walker, N. R.; Legon, A. C. J. Chem. Phys. 2011, 135, 224309). Analysis of the ability of theoretical methods to account for the dispersion interaction present in these complexes leads to the conclusion that MP2 and B3LYP-D3, which produce very similar results, are the better performing methods, followed by B97-D and the M06 suite of functionals; the popular B3LYP as well as X3LYP perform poorly and significantly underestimate the interaction strength. The orbitals responsible for the interaction are identified through Edmiston-Ruedenberg localization; it is shown that, by combining the key orbitals, it is possible to observe a molecular orbital picture of a σ-hole interaction.

  16. Investigation of hyperfine interactions in DNA nitrogenous bases using perturbed angular correlation spectroscopy

    International Nuclear Information System (INIS)

    Silva, Andreia dos Santos; Carbonari, Artur Wilson; Lapolli, Andre Luis; Saxena, Rajendra Narain; Saitovitch, Henrique

    2013-01-01

    Perturbed γγ angular correlations (PAC) spectroscopy has been used to study the DNA nitrogenous bases (adenine, cytosine, guanine, thymine), using 111 In→ 111 Cd and 111m Cd→ 111 Cd probe nuclei. One of the advantages of applying PAC technique to biological molecules is that the experiments can be carried out on molecules in aqueous solution [1], approaching the function of molecules under conditions that are close to in vivo conditions. The measurements were carried out for DNA nitrogenous bases molecules at 295 K and 77 K in order to investigate dynamic and static hyperfine interactions, respectively. The interpretation of the results was based on the measurements of dynamic interaction characterized by the decay constant from which valuable information on the macroscopic behavior of the molecules was obtained [2; 3]. On the other hand, PAC measurements at low temperature showed interaction frequency (ν Q ), asymmetry parameter (η) and the distribution of the quadrupole frequency (δ). These parameters provide a local microscopic description of the chemical environment in the neighborhood of the probe nuclei. Results showed differences in the hyperfine interactions of probe nuclei bound to the studied biomolecules. Such differences were observed by variations in the hyperfine parameters, which depended on the type of biomolecule and the results also showed that the probe nuclei bounded at the molecules in some cases and at others did not. (author)

  17. Investigating interactional competence using video recordings in ESL classrooms to enhance communication

    Science.gov (United States)

    Krishnasamy, Hariharan N.

    2016-08-01

    Interactional competence, or knowing and using the appropriate skills for interaction in various communication situations within a given speech community and culture is important in the field of business and professional communication [1], [2]. Similar to many developing countries in the world, Malaysia is a growing economy and undergraduates will have to acquire appropriate communication skills. In this study, two aspects of the interactional communicative competence were investigated, that is the linguistic and paralinguistic behaviors in small group communication as well as conflict management in small group communication. Two groups of student participants were given a problem-solving task based on a letter of complaint. The two groups of students were video recorded during class hours for 40 minutes. The videos and transcription of the group discussions were analyzed to examine the use of language and interaction in small groups. The analysis, findings and interpretations were verified with three lecturers in the field of communication. The results showed that students were able to accomplish the given task using verbal and nonverbal communication. However, participation was unevenly distributed with two students talking for less than a minute. Negotiation was based more on alternative views and consensus was easily achieved. In concluding, suggestions are given on ways to improve English language communication.

  18. Investigating local network interactions underlying first- and second-order processing.

    Science.gov (United States)

    Ellemberg, Dave; Allen, Harriet A; Hess, Robert F

    2004-01-01

    We compared the spatial lateral interactions for first-order cues to those for second-order cues, and investigated spatial interactions between these two types of cues. We measured the apparent modulation depth of a target Gabor at fixation, in the presence and the absence of horizontally flanking Gabors. The Gabors' gratings were either added to (first-order) or multiplied with (second-order) binary 2-D noise. Apparent "contrast" or modulation depth (i.e., the perceived difference between the high and low luminance regions for the first-order stimulus, or between the high and low contrast regions for the second-order stimulus) was measured with a modulation depth-matching paradigm. For each observer, the first- and second-order Gabors were equated for apparent modulation depth without the flankers. Our results indicate that at the smallest inter-element spacing, the perceived reduction in modulation depth is significantly smaller for the second-order than for the first-order stimuli. Further, lateral interactions operate over shorter distances and the spatial frequency and orientation tuning of the suppression effect are broader for second- than first-order stimuli. Finally, first- and second-order information interact in an asymmetrical fashion; second-order flankers do not reduce the apparent modulation depth of the first-order target, whilst first-order flankers reduce the apparent modulation depth of the second-order target.

  19. Intermolecular interaction of fosinopril with bovine serum albumin (BSA): The multi-spectroscopic and computational investigation.

    Science.gov (United States)

    Zhou, Kai-Li; Pan, Dong-Qi; Lou, Yan-Yue; Shi, Jie-Hua

    2018-04-16

    The intermolecular interaction of fosinopril, an angiotensin converting enzyme inhibitor with bovine serum albumin (BSA), has been investigated in physiological buffer (pH 7.4) by multi-spectroscopic methods and molecular docking technique. The results obtained from fluorescence and UV absorption spectroscopy revealed that the fluorescence quenching mechanism of BSA induced by fosinopril was mediated by the combined dynamic and static quenching, and the static quenching was dominant in this system. The binding constant, K b , value was found to lie between 2.69 × 10 3 and 9.55 × 10 3  M -1 at experimental temperatures (293, 298, 303, and 308 K), implying the low or intermediate binding affinity between fosinopril and BSA. Competitive binding experiments with site markers (phenylbutazone and diazepam) suggested that fosinopril preferentially bound to the site I in sub-domain IIA on BSA, as evidenced by molecular docking analysis. The negative sign for enthalpy change (ΔH 0 ) and entropy change (ΔS 0 ) indicated that van der Waals force and hydrogen bonds played important roles in the fosinopril-BSA interaction, and 8-anilino-1-naphthalenesulfonate binding assay experiments offered evidence of the involvements of hydrophobic interactions. Moreover, spectroscopic results (synchronous fluorescence, 3-dimensional fluorescence, and Fourier transform infrared spectroscopy) indicated a slight conformational change in BSA upon fosinopril interaction. Copyright © 2018 John Wiley & Sons, Ltd.

  20. A method for investigating protein-protein interactions related to Salmonella typhimurium pathogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Saiful M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Shi, Liang [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Yoon, Hyunjin [Dartmouth College, Hanover, NH (United States); Ansong, Charles [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rommereim, Leah M. [Dartmouth College, Hanover, NH (United States); Norbeck, Angela D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Auberry, Kenneth J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Moore, R. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Adkins, Joshua N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Heffron, Fred [Oregon Health and Science Univ., Portland, OR (United States); Smith, Richard D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2009-02-10

    We successfully modified an existing method to investigate protein-protein interactions in the pathogenic bacterium Salmonella typhimurium (STM). This method includes i) addition of a histidine-biotin-histidine tag to the bait proteins via recombinant DNA techniques; ii) in vivo cross-linking with formaldehyde; iii) tandem affinity purification of bait proteins under fully denaturing conditions; and iv) identification of the proteins cross-linked to the bait proteins by liquid-chromatography in conjunction with tandem mass-spectrometry. In vivo cross-linking stabilized protein interactions permitted the subsequent two-step purification step conducted under denaturing conditions. The two-step purification greatly reduced nonspecific binding of non-cross-linked proteins to bait proteins. Two different negative controls were employed to reduce false-positive identification. In an initial demonstration of this approach, we tagged three selected STM proteins- HimD, PduB and PhoP- with known binding partners that ranged from stable (e.g., HimD) to transient (i.e., PhoP). Distinct sets of interacting proteins were identified with each bait protein, including the known binding partners such as HimA for HimD, as well as anticipated and unexpected binding partners. Our results suggest that novel protein-protein interactions may be critical to pathogenesis by Salmonella typhimurium. .

  1. Well-Controlled Cell-Trapping Systems for Investigating Heterogeneous Cell-Cell Interactions.

    Science.gov (United States)

    Kamiya, Koki; Abe, Yuta; Inoue, Kosuke; Osaki, Toshihisa; Kawano, Ryuji; Miki, Norihisa; Takeuchi, Shoji

    2018-03-01

    Microfluidic systems have been developed for patterning single cells to study cell-cell interactions. However, patterning multiple types of cells to understand heterogeneous cell-cell interactions remains difficult. Here, it is aimed to develop a cell-trapping device to assemble multiple types of cells in the well-controlled order and morphology. This device mainly comprises a parylene sheet for assembling cells and a microcomb for controlling the cell-trapping area. The cell-trapping area is controlled by moving the parylene sheet on an SU-8 microcomb using tweezers. Gentle downward flow is used as a driving force for the cell-trapping. The assembly of cells on a parylene sheet with round and line-shaped apertures is demonstrated. The cell-cell contacts of the trapped cells are then investigated by direct cell-cell transfer of calcein via connexin nanopores. Finally, using the device with a system for controlling the cell-trapping area, three different types of cells in the well-controlled order are assembled. The correct cell order rate obtained using the device is 27.9%, which is higher than that obtained without the sliding parylene system (0.74%). Furthermore, the occurrence of cell-cell contact between the three cell types assembled is verified. This cell-patterning device will be a useful tool for investigating heterogeneous cell-cell interactions. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Investigation of processes of interaction relativistic electrons with the solutions of organic dyes

    International Nuclear Information System (INIS)

    Buki, A.Yu.; Gokov, S.P.; Kazarinov, Yu.G.; Kalenik, S.A.; Kasilov, V.I.; Kochetov, S.S.; Makhnenko, P.L.; Mel'nitskiy, I.V.; Tverdohvalov, A.V.; Tsyatsko, V.V.; Shopen, O.A.

    2014-01-01

    Investigation of the processes of interaction of ionizing radiation with complex organic objects can solve a number of fundamental and applied problems in radiation physics, chemistry and biology. In this work we investigated the dose dependence (dose range 1...5MRad) optical density relative concentrations of water, alcohol and glycerine solution following organic dyes: methylene blue - C 16 H 18 N 3 SCl and methyl orange - C 14 H 14 N 3 O 3 SNa, irradiated with an electron beam with an energy of 16MeV. In the analysis of absorption spectra, it was found that water solutions of dyes have less resistance to radiation as compared with the alcohol and glycerol. Also, all solutions of methyl orange less radiation resistant than the methylene blue solution. Analysis of the spectra showed that these relationships are close to linear in the range of doses. To understand the physical and chemical processes occurring in the interaction of relativistic electrons with the studied organic objects were performed the computer simulations of the energy spectra of ions formed due to breaking the chemical bonds of molecules of dye solutions using the program SRIM-2010. The analysis showed that radiation - stimulated chemical processes play a major role in the destruction of the source of organic dye molecules. The remaining processes (interaction of electrons and nuclei, the cascade processes) accounts for about 10% of all molecular breaks.

  3. Importance of core/concrete interactions for German risk investigations and experimental verification

    International Nuclear Information System (INIS)

    Rohde, J.; Hicken, E.F.; Friederichs, H.G.; Schroedl, E.

    1987-01-01

    The relevance of Molten Core Concrete Interactions (MCCI) for risk oriented investigations of German LWR-plants is evaluated. The problems of MCCI have been intensely investigated since the mid seventies in connection with the German Risk Study, Phase A and B on PWR plants of German design. Many examinations of both theoretical and experimental nature have led to the development of computer codes like WECHSL. The basis for verification is the internationally well accepted BETA experiment. Code WECHSL and the knowledge gained from the BETA experiment have been applied for the final investigations in German Risk Study, Phase B. Knowledge gained will be illustrated and its importance MCCI for German LWR-concepts will be shown

  4. Experimental and theoretical investigations of soil-structure interaction effect at HDR-reactor-building

    International Nuclear Information System (INIS)

    Wassermann, K.

    1983-01-01

    Full-scale dynamic testing on intermediate and high levels was performed at the Heissdampfreaktor (HDR) in 1979. Various types of dynamic forces were applied and response of the reactor containment structure and internal components was measured. Precalculations of dynamic behaviour and response of the structure were made through different mathematical models for the structure and the underlying soil. Soil-Structure Interaction effects are investigated and different theoretical models are compared with experimental results. In each model, the soil is represented by springs attached to the structural model. Stiffnesses of springs are calculated by different finite-element idealizations and half-space approximations. Eigenfrequencies and damping values related to interaction effects (translation, rocking, torsion) are identified from test results. The comparisons of dynamic characteristic of the soil-structure system between precalculations and test results show good agreement in general. (orig.)

  5. Unsteady Aerodynamic Investigation of the Propeller-Wing Interaction for a Rocket Launched Unmanned Air Vehicle

    Directory of Open Access Journals (Sweden)

    G. Q. Zhang

    2013-01-01

    Full Text Available The aerodynamic characteristics of propeller-wing interaction for the rocket launched UAV have been investigated numerically by means of sliding mesh technology. The corresponding forces and moments have been collected for axial wing placements ranging from 0.056 to 0.5D and varied rotating speeds. The slipstream generated by the rotating propeller has little effects on the lift characteristics of the whole UAV. The drag can be seen to remain unchanged as the wing's location moves progressively closer to the propeller until 0.056D away from the propeller, where a nearly 20% increase occurred sharply. The propeller position has a negligible effect on the overall thrust and torque of the propeller. The efficiency affected by the installation angle of the propeller blade has also been analyzed. Based on the pressure cloud and streamlines, the vortices generated by propeller, propeller-wing interaction, and wing tip have also been captured and analyzed.

  6. Geomechanical analyses to investigate wellbore/mine interactions in the Potash Enclave of Southeastern New Mexico.

    Energy Technology Data Exchange (ETDEWEB)

    Ehgartner, Brian L.; Bean, James E. (Sandia Staffing Alliance, LLC, Albuquerque, NM); Arguello, Jose Guadalupe, Jr.; Stone, Charles Michael

    2010-04-01

    Geomechanical analyses have been performed to investigate potential mine interactions with wellbores that could occur in the Potash Enclave of Southeastern New Mexico. Two basic models were used in the study; (1) a global model that simulates the mechanics associated with mining and subsidence and (2) a wellbore model that examines the resulting interaction impacts on the wellbore casing. The first model is a 2D approximation of a potash mine using a plane strain idealization for mine depths of 304.8 m (1000 ft) and 609.6 m (2000 ft). A 3D wellbore model then considers the impact of bedding plane slippage across single and double cased wells cemented through the Salado formation. The wellbore model establishes allowable slippage to prevent casing yield.

  7. A versatile tunable microcavity for investigation of light-matter interaction

    Science.gov (United States)

    Mochalov, Konstantin E.; Vaskan, Ivan S.; Dovzhenko, Dmitriy S.; Rakovich, Yury P.; Nabiev, Igor

    2018-05-01

    Light-matter interaction between a molecular ensemble and a confined electromagnetic field is a promising area of research, as it allows light-control of the properties of coupled matter. The common way to achieve coupling is to place an ensemble of molecules or quantum emitters into a cavity. In this approach, light-matter coupling is evidenced by modification of the spectral response of the emitter, which depends on the strength of interaction between emitter and cavity modes. However, there is not yet a user-friendly approach that allows the study of a large number of different and replaceable samples in a wide optical range using the same resonator. Here, we present the design of such a device that can speed up and facilitate investigation of light-matter interaction ranging from weak to strong coupling regimes in ultraviolet-visible and infrared (IR) spectral regions. The device is based on a tunable unstable λ/2 Fabry-Pérot microcavity consisting of plane and convex mirrors that satisfy the plane-parallelism condition at least at one point of the curved mirror and minimize the mode volume. Fine tuning of the microcavity length is provided by a Z-piezopositioner in a range up to 10 μm with a step of several nm. This design makes a device a versatile instrument that ensures easy finding of optimal conditions for light-matter interaction for almost any sample in both visible and IR areas, enabling observation of both electronic and vibrational couplings with microcavity modes thus paving the way to investigation of various coupling effects including Raman scattering enhancement, modification of chemical reactivity rate, lasing, and long-distance nonradiative energy transfer.

  8. Biochemical and biophysical investigations of the interaction between human glucokinase and pro-apoptotic BAD.

    Science.gov (United States)

    Rexford, Alix; Zorio, Diego A R; Miller, Brian G

    2017-01-01

    The glycolytic enzyme glucokinase (GCK) and the pro-apoptotic protein BAD reportedly reside within a five-membered complex that localizes to the mitochondria of mammalian hepatocytes and pancreatic β-cells. Photochemical crosslinking studies using a synthetic analog of BAD's BH3 domain and in vitro transcription/translation experiments support a direct interaction between BAD and GCK. To investigate the biochemical and biophysical consequences of the BAD:GCK interaction, we developed a method for the production of recombinant human BAD. Consistent with published reports, recombinant BAD displays high affinity for Bcl-xL (KD = 7 nM), and phosphorylation of BAD at S118, within the BH3 domain, abolishes this interaction. Unexpectedly, we do not detect association of recombinant, full-length BAD with recombinant human pancreatic GCK over a range of protein concentrations using various biochemical methods including size-exclusion chromatography, chemical cross-linking, analytical ultracentrifugation, and isothermal titration calorimetry. Furthermore, fluorescence polarization assays and isothermal titration calorimetry detect no direct interaction between GCK and BAD BH3 peptides. Kinetic characterization of GCK in the presence of high concentrations of recombinant BAD show modest (BAD BH3 peptides. These results raise questions as to the mechanism of action of stapled peptide analogs modeled after the BAD BH3 domain, which reportedly enhance the Vmax value of GCK and stimulate insulin release in BAD-deficient islets. Based on our results, we postulate that the BAD:GCK interaction, and any resultant regulatory effect(s) upon GCK activity, requires the participation of additional members of the mitochondrial complex.

  9. Experimental investigation of gravity wave turbulence and of non-linear four wave interactions..

    Science.gov (United States)

    Berhanu, Michael

    2017-04-01

    Using the large basins of the Ecole Centrale de Nantes (France), non-linear interactions of gravity surface waves are experimentally investigated. In a first part we study statistical properties of a random wave field regarding the insights from the Wave Turbulence Theory. In particular freely decaying gravity wave turbulence is generated in a closed basin. No self-similar decay of the spectrum is observed, whereas its Fourier modes decay first as a time power law due to nonl-inear mechanisms, and then exponentially due to linear viscous damping. We estimate the linear, non-linear and dissipative time scales to test the time scale separation. By estimation of the mean energy flux from the initial decay of wave energy, the Kolmogorov-Zakharov constant of the weak turbulence theory is evaluated. In a second part, resonant interactions of oblique surface gravity waves in a large basin are studied. We generate two oblique waves crossing at an acute angle. These mother waves mutually interact and give birth to a resonant wave whose properties (growth rate, resonant response curve and phase locking) are fully characterized. All our experimental results are found in good quantitative agreement with four-wave interaction theory. L. Deike, B. Miquel, P. Gutiérrez, T. Jamin, B. Semin, M. Berhanu, E. Falcon and F. Bonnefoy, Role of the basin boundary conditions in gravity wave turbulence, Journal of Fluid Mechanics 781, 196 (2015) F. Bonnefoy, F. Haudin, G. Michel, B. Semin, T. Humbert, S. Aumaître, M. Berhanu and E. Falcon, Observation of resonant interactions among surface gravity waves, Journal of Fluid Mechanics (Rapids) 805, R3 (2016)

  10. Investigation of Ion-Solvent Interactions in Nonaqueous Electrolytes Using in Situ Liquid SIMS

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yanyan; Su, Mao; Yu, Xiaofei; Zhou, Yufan; Wang, Jungang; Cao, Ruiguo; Xu, Wu; Wang, Chongmin; Baer, Donald R.; Borodin, Oleg; Xu, Kang; Wang, Yanting; Wang, Xue-Lin; Xu, Zhijie; Wang, Fuyi; Zhu, Zihua

    2018-02-06

    Ion-solvent interactions in non-aqueous electrolytes are of fundamental interest and practical importance, yet debates regarding ion preferential solvation and coordination numbers persist. In this work, in situ liquid SIMS was used to examine ion-solvent interactions in three representative electrolytes, i.e., lithium hexafluorophosphate (LiPF6) at 1.0 M in ethylene carbonate (EC)-dimethyl carbonate (DMC), and lithium bis(fluorosulfonyl)imide (LiFSI) at both low (1.0 M) and high (4.0 M) concentrations in 1,2-dimethoxyethane (DME). In the positive ion mode, solid molecular evidence strongly supports the preferential solvation of Li+ by EC. Besides, from the negative spectra, we also found that PF6- forms association with EC, which has been neglected by previous studies due to the relatively weak interaction. While in both LiFSI in DME electrolytes, no evidence shows that FSI- is associated with DME. Furthermore, strong salt ion cluster signals were observed in the 1.0 M LiPF6 in EC-DMC electrolyte, suggesting that a significant amount of Li+ ions stay in vicinity of anions. In sharp comparison, weak ion cluster signals were detected in dilute LiFSI in DME electrolyte, suggesting most ions are well separated, in agreement with our molecular dynamics (MD) simulation results. These findings indicate that with virtues of little bias on detecting positive and negative ions and the capability of directly analyzing concentrated electrolytes, in situ liquid SIMS is a powerful tool that can provide key evidence for improved understanding on the ion-solvent interactions in non-aqueous electrolytes. Therefore, we anticipate wide applications of in situ liquid SIMS on investigations of various ion-solvent interactions in the near future.

  11. Molecular dynamics investigation of nanoscale substrate topography and its interaction with liquids

    Science.gov (United States)

    Cordeiro Rodrigues, Jhonatam

    Nanotechnology has been presenting successful applications in several areas. However, experimentation with nanoscale materials is costly and limited in analysis capability. This research investigates the use of molecular dynamics (MD) simulations to model and study nanomaterials and manufacturing processes. MD simulations are employed to reduce cost, optimize design, increase productivity and allow for the investigation of material interactions not yet observable through experimentation. This work investigates the interaction of water with substrates at the nanoscale. The effect of temperature, droplet impingement velocities and size, as well as substrate material, are investigated at the nanoscale. Several substrate topography designs were modeled to reveal their influence on the wettability of the substrate. Nanoscale gold and silicon substrates are more hydrophilic at higher temperatures than at room temperature. The reduction in droplet diameter increases its wettability. High impingement velocity of droplets does not influence final wettability of substrates but induces higher diffusion rates of droplets in a heated environment. Droplets deposited over a gradient of surface exposure presents spontaneous movement. The Leidenfrost effect was investigated at the nanoscale. Droplets of 4 and 10nm in diameter presented behaviors pertinent to the Leidenfrost effect at 373K, significantly lower than at micro scale and of potential impact to the field. Topographical features were manipulated using superhydrophobic coating resulting in micro whiskers. Nanoimprint lithography (NIL) was used to manufacture substrate topographies at the nanoscale. Water droplets were deposited on the substrates and their wettability was measured using droplet contact angles. Lower surface area exposure resulted in higher contact angles. The experimental relationships between surface topography and substrate wettability were used to validate the insights gained from MD simulations for

  12. Interaction of water with (silico)aluminophosphate zeotypes: a comparative investigation using dispersion-corrected DFT.

    Science.gov (United States)

    Fischer, Michael

    2016-06-21

    Porous aluminophosphates (AlPOs) and silicoaluminophosphates (SAPOs) with zeolite-like structures have received considerable attention as potential adsorbents for heat transformation applications using water adsorption/desorption cycles. Since a detailed experimental characterisation of the water adsorption properties has only been performed for some of these materials, such as AlPO-18 (AEI topology) and SAPO-34 (CHA topology), more systematic insights regarding the influence of the pore topology and (for SAPOs) the arrangement of the framework protons on the affinity towards water are lacking. To study the relationships between structure and properties in more detail, the interaction of water with six structurally different AlPOs (with AEI, AFX, CHA, ERI, GIS, RHO topologies) and their SAPO analogues was investigated using dispersion-corrected density-functional theory (DFT-D) calculations. Different possible locations of silicon atoms and charge-balancing protons were considered for the SAPO systems. The calculations for SAPOs at low water loadings (one H2O molecule per framework proton) revealed that the interaction energies exhibit a considerable variation, ranging from -75 to -100 kJ mol(-1) (per water molecule). The differences in interaction energy were rationalised with the different structural environment of the framework protons at which the water molecules are adsorbed. At high water uptakes (near saturation), interaction energies in the range of -65 kJ mol(-1) were obtained for all AlPOs, and there was no evidence for a marked influence of pore size and/or topology on the interaction strength. The interaction of water with SAPOs was found to be approximately 5 kJ mol(-1) stronger than for AlPOs due to an increased contribution of electrostatic interactions. An analysis of the structural changes upon water adsorption revealed striking differences between the distinct topologies, with the materials with GIS and RHO topologies being distorted much more

  13. Investigation of sodium concrete interaction and the effect of different by-products

    International Nuclear Information System (INIS)

    Schultheiss, G.F.; Fritzke, H.W.

    1983-01-01

    For heat transfer at temperatures of more than 770 K sodium or sodium-potassium alloy is used in fast breeder reactors or solar power plants. In case of leakage of hot liquid metal concrete is loaded thermally and chemically. The interaction of sodium with several concretes of different composition has been investigated experimentally and theoretically. Especially the quartz content of concrete has a significant influence on reaction behavior. Quartz-containing concrete specimens were severely damaged at temperatures of more than 600 0 C. Computer code modelling shows good agreement with experiments. (orig.) [de

  14. UCN storage experiment for the investigation of the anomalous interaction with wall surfaces

    International Nuclear Information System (INIS)

    Kawabata, Yuji; Utsuro, Masahiko; Steyerl, A.; Malik, S.S.; Geltenbort, P.; Neumair, S.; Nesvizhevsky, V.V.

    1997-01-01

    The UCN experiment for the investigation of the anomalous interaction with wall surfaces was performed in the ILL UCN source. UCN is monochromated by the gravity and stored in the spectrometer with rectangular trap which is the Fombrin-grease coated box of 67x67cm 2 cross section and 20cm height. The measured energy distribution of stored UCN shows the indication of 'initial micro-heating'. The order of energy gain is ∼ 10 -10 eV in the initial several 100sec of storage. (author)

  15. Investigations of fast neutron production by 190 GeV/c muon interactions on graphite target

    CERN Document Server

    Chazal, V; Cook, B; Henrikson, H; Jonkmans, G; Paic, A; Mascarenhas, N; Vogel, P; Vuilleumier, J L

    2002-01-01

    The production of fast neutrons (1 MeV - 1 GeV) in high energy muon-nucleus interactions is poorly understood, yet it is fundamental to the understanding of the background in many underground experiments. The aim of the present experiment (CERN NA55) was to measure spallation neutrons produced by 190 GeV/c muons scattering on carbon target. We have investigated the energy spectrum and angular distribution of spallation neutrons, and we report the result of our measurement of the neutron production differential cross section.

  16. Investigations of fast neutron production by 190 GeV/c muon interactions on different targets

    International Nuclear Information System (INIS)

    Chazal, V.; Boehm, F.; Cook, B.; Henrikson, H.; Jonkmans, G.; Paic, A.; Mascarenhas, N.; Vogel, P.; Vuilleumier, J.-L.

    2002-01-01

    The production of fast neutrons (1 MeV-1 GeV) in high-energy muon-nucleus interactions is poorly understood, yet it is fundamental to the understanding of the background in many underground experiments. The aim of the present experiment (CERN NA55) was to measure spallation neutrons produced by 190 GeV/c muons scattering on carbon, copper and lead targets. We have investigated the energy spectrum and angular distribution of spallation neutrons, and we report the result of our measurement of the neutron production differential cross-section

  17. Investigation of fluid-structure interaction with various types of junction coupling

    Science.gov (United States)

    Ahmadi, A.; Keramat, A.

    2010-10-01

    In this study of water hammer with fluid-structure interaction (FSI) the main aim was the investigation of junction coupling effects. Junction coupling effects were studied in various types of discrete points, such as pumps, valves and branches. The emphasis was placed on an unrestrained pump and branch in the system, and the associated relations were derived for modelling them. Proposed relations were considered as boundary conditions for the numerical modelling which was implemented using the finite element method for the structural equations and the method of characteristics for the hydraulic equations. The results can be used by engineers in finding where junction coupling is significant.

  18. Theoretical investigation of the weak interaction between graphene and alcohol solvents

    Science.gov (United States)

    Wang, Haining; Chen, Sian; Lu, Shanfu; Xiang, Yan

    2017-05-01

    The dispersion of graphene in five different alcohol solvents was investigated by evaluating the binding energy between graphene and alcohol molecules using DFT-D method. The calculation showed the most stable binding energy appeared at the distance of ∼3.5 Å between graphene and alcohol molecules and increased linearly as changing the alcohol from methanol to 1-pentanol. The weak interaction was further graphically illustrated using the reduced density gradient method. The theoretical study revealed alcohols with more carbon atoms could be a good starting point for screening suitable solvents for graphene dispersion.

  19. Investigation of the proton-neutron interaction by high-precision nuclear mass measurements

    CERN Multimedia

    Savreux, R P; Akkus, B

    2007-01-01

    We propose to measure the atomic masses of a series of short-lived nuclides, including $^{70}$Ni, $^{122-130}$Cd, $^{134}$Sn, $^{138,140}$Xe, $^{207-210}$Hg, and $^{223-225}$Rn, that contribute to the investigation of the proton-neutron interaction and its role in nuclear structure. The high-precision mass measurements are planned for the Penning trap mass spectrometer ISOLTRAP that reaches the required precision of 10 keV in the nuclear mass determination.

  20. Exploration of gene-environment interactions, maternal effects and parent of origin effects in the etiology of hypospadias

    NARCIS (Netherlands)

    Zanden, L.F.M. van der; Galesloot, T.E.; Feitz, W.F.J.; Brouwers, M.M.; Shi, M.; Knoers, N.V.; Franke, B.; Roeleveld, N.; Rooij, I.A.L.M. van

    2012-01-01

    PURPOSE: Hypospadias is a common congenital malformation of the male external genitalia. Association studies for single nucleotide polymorphisms in genes encoding steroid 5alpha-reductase, estrogen receptors 1 and 2, and activating transcription factor 3 have been equivocal. We examined whether

  1. Angiotensin converting enzyme insertion/deletion genotype, exercise and physical decline: evidence of a gene-environment interaction

    NARCIS (Netherlands)

    Kritchevsky, S.B.; Nicklas, B.J.; Visser, M.; Simonsick, E.M.; Newman, A.B.; Harris, T.B.; Lange, E.M.; Penninx, B.W.J.H.; Goodpaster, B.H.; Satterfield, S.; Colbert, L.; Rubin, S; Pahor, M.

    2005-01-01

    Context: Physical performance in response to exercise appears to be influenced by the angiotensin-converting enzyme (ACE) insertion (I)/deletion (D) genotype in young adults, but whether this relationship could help explain variation in older individuals' response to exercise has not been well

  2. Gene/Environment Interaction in Atherosclerosis: An Example of Clinical Medicine as Seen from the Evolutionary Perspective

    Directory of Open Access Journals (Sweden)

    Gerhard Mertens

    2010-01-01

    The chronic multifactorial disease of atherosclerosis clearly illustrates the Darwinian paradigm. Recent research, combining the effects of genes and environment, has provided surprising clues to the pathogenesis of this major public health problem. This example makes a strong case for recognizing evolution biology as a basic science for medicine.

  3. Chronic and Acute Stress, Gender, and Serotonin Transporter Gene-Environment Interactions Predicting Depression Symptoms in Youth

    Science.gov (United States)

    Hammen, Constance; Brennan, Patricia A.; Keenan-Miller, Danielle; Hazel, Nicholas A.; Najman, Jake M.

    2010-01-01

    Background: Many recent studies of serotonin transporter gene by environment effects predicting depression have used stress assessments with undefined or poor psychometric methods, possibly contributing to wide variation in findings. The present study attempted to distinguish between effects of acute and chronic stress to predict depressive…

  4. The Dopamine D2 Receptor Gene, Perceived Parental Support, and Adolescent Loneliness: Longitudinal Evidence for Gene-Environment Interactions

    Science.gov (United States)

    van Roekel, Eeske; Goossens, Luc; Scholte, Ron H. J.; Engels, Rutger C. M. E.; Verhagen, Maaike

    2011-01-01

    Background: Loneliness is a common problem in adolescence. Earlier research focused on genes within the serotonin and oxytocin systems, but no studies have examined the role of dopamine-related genes in loneliness. In the present study, we focused on the dopamine D2 receptor gene (DRD2). Methods: Associations among the DRD2, sex, parental support,…

  5. Physical activity, diet and gene-environment interactions in relation to body mass index and waist circumference

    DEFF Research Database (Denmark)

    Karnehed, Nina; Tynelius, Per; Heitmann, Berit L

    2006-01-01

    OBJECTIVE: The aim of the present study was to examine the relationships between genetic susceptibility to obesity, physical activity (PA), dietary fibre, sugar and fat intakes and 4-year changes in body mass index (BMI) and attained waist circumference (WC) in a cohort of 287 monozygotic and 189...

  6. The dopamine D2 receptor gene, perceived parental support, and adolescent loneliness : longitudinal evidence for gene-environment interactions

    NARCIS (Netherlands)

    van Roekel, Eeske; Goossens, Luc; Scholte, Ron H. J.; Engels, Rutger C. M. E.; Verhagen, Maaike

    2011-01-01

    Background: Loneliness is a common problem in adolescence. Earlier research focused on genes within the serotonin and oxytocin systems, but no studies have examined the role of dopamine-related genes in loneliness. In the present study, we focused on the dopamine D2 receptor gene (DRD2). Methods:

  7. Investigation of ion acceleration mechanism through laser-matter interaction in femtosecond domain

    Energy Technology Data Exchange (ETDEWEB)

    Altana, C., E-mail: altana@lns.infn.it [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Astronomia, Università degli Studi di Catania, Via S. Sofia 64, 95123 Catania (Italy); Muoio, A. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Dipartimento di Fisica e Scienze della Terra, Università degli Studi di Messina, Viale F.S. D’Alcontres 31, 98166 Messina (Italy); Lanzalone, G. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Università degli Studi di Enna “Kore”, Via delle Olimpiadi, 94100 Enna (Italy); Tudisco, S. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Brandi, F. [CNR, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova (Italy); Cirrone, G.A.P. [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud, Via S. Sofia 62, 95123 Catania (Italy); Cristoforetti, G. [CNR, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Fazzi, A. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Ferrara, P.; Fulgentini, L. [CNR, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Giove, D. [Energy Department, Polytechnic of Milan and INFN, Milan (Italy); Koester, P. [CNR, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Labate, L. [CNR, Intense Laser Irradiation Laboratory, Via G. Moruzzi 1, 56124 Pisa (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); and others

    2016-09-01

    An experimental campaign aiming to investigate the ion acceleration mechanisms through laser-matter interaction in the femtosecond domain has been carried out at the ILIL facility at a laser intensity of up to 2×10{sup 19} W/cm{sup 2}. A Thomson Parabola Spectrometer was used to identify different ion species and measure the energy spectra and the corresponding temperature parameters. We discuss the dependence of the protons spectra upon the structural characteristics of the targets (thickness and atomic mass) and the role of surface versus target bulk during acceleration process. - Highlights: • Ion acceleration mechanism in TNSA regime was investigated. • The energy spectra and the corresponding temperature parameters were measured. • Dependence of the spectra upon the target structural characteristics was discussed.

  8. Polyphilic Interactions as Structural Driving Force Investigated by Molecular Dynamics Simulation (Project 7

    Directory of Open Access Journals (Sweden)

    Christopher Peschel

    2017-09-01

    Full Text Available We investigated the effect of fluorinated molecules on dipalmitoylphosphatidylcholine (DPPC bilayers by force-field molecular dynamics simulations. In the first step, we developed all-atom force-field parameters for additive molecules in membranes to enable an accurate description of those systems. On the basis of this force field, we performed extensive simulations of various bilayer systems containing different additives. The additive molecules were chosen to be of different size and shape, and they included small molecules such as perfluorinated alcohols, but also more complex molecules. From these simulations, we investigated the structural and dynamic effects of the additives on the membrane properties, as well as the behavior of the additive molecules themselves. Our results are in good agreement with other theoretical and experimental studies, and they contribute to a microscopic understanding of interactions, which might be used to specifically tune membrane properties by additives in the future.

  9. Investigation of a mutual interaction force at different pressure amplitudes in sulfuric acid

    International Nuclear Information System (INIS)

    Rezaee, Nastaran; Sadighi-Bonabi, Rasoul; Mirheydari, Mona; Ebrahimi, Homa

    2011-01-01

    This paper investigates the secondary Bjerknes force for two oscillating bubbles in various pressure amplitudes in a concentration of 95% sulfuric acid. The equilibrium radii of the bubbles are assumed to be smaller than 10 μm at a frequency of 37 kHz in various strong driving acoustical fields around 2.0 bars (1 bar=10 5 Pa). The secondary Bjerknes force is investigated in uncoupled and coupled states between the bubbles, with regard to the quasi-adiabatic model for the bubble interior. It finds that the value of the secondary Bjerknes force depends on the driven pressure of sulfuric acid and its amount would be increased by liquid pressure amplitude enhancement. The results show that the repulsion area of the interaction force would be increased by increasing the driven pressure because of nonlinear oscillation of bubbles. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  10. Investigation Of Interaction Between Nitinol Stent And A Vascular Plaque Using Finite Element Method

    Directory of Open Access Journals (Sweden)

    Recep Güneş

    2012-06-01

    Full Text Available In this study, the interaction between the Nitinol stent and the artery with plaque was investigated using finite element method. The occurring pressure values during the cardiac contraction (systolic and loosening (diastolic were applied as loading to the modeled system with Nitinol stent. In the light of the stress values, the suitability of the Nitinol stent in an artery with plaque was investigated. In the analysis, Nitinol stent was assumed to be shape memory alloy, and artery and plaque were assumed to behave linearly elastic. As a result, the stress and deformations in the plaque and artery due to the interference of Nitinol stent were discussed and concluded that the structure of artery with plaque can be expanded in accordance with Nitinol stent.

  11. The interactions between lipase and pyridinium ligands investigated by electrochemical and spectrophotometric methods

    Directory of Open Access Journals (Sweden)

    Simona Patriche

    2016-04-01

    Full Text Available The interaction between pyridinium ligands derived from 4,4’-bipyridine (N,N’-bis(p-bromophenacyl-4,4’-bipyridinium dibromide – Lr and (N,N’-bis(p-bromophenacyl-1,2-bis (4-pyridyl ethane dibromide – Lm with lipase enzyme was evaluated. The stability of the pyridinium ligands, having an essential role in biological systems, in 0.1 M KNO3 as supporting electrolyte is influenced by the lipase concentration added. The pH and conductometry measurements in aqueous solution suggest a rapid ionic exchange process. The behavior of pyridinium ligands in the presence of lipase is investigated by cyclic voltammetry and UV/Vis spectroscopy, which indicated bindings and changes from the interaction between them. The voltammograms recorded on the glassy carbon electrode showed a more intense electronic transfer for the Lr interaction with lipase compared to Lm, which is due to the absence of mobile ethylene groups from Lr structure.

  12. Integration of statistical modeling and high-content microscopy to systematically investigate cell-substrate interactions.

    Science.gov (United States)

    Chen, Wen Li Kelly; Likhitpanichkul, Morakot; Ho, Anthony; Simmons, Craig A

    2010-03-01

    Cell-substrate interactions are multifaceted, involving the integration of various physical and biochemical signals. The interactions among these microenvironmental factors cannot be facilely elucidated and quantified by conventional experimentation, and necessitate multifactorial strategies. Here we describe an approach that integrates statistical design and analysis of experiments with automated microscopy to systematically investigate the combinatorial effects of substrate-derived stimuli (substrate stiffness and matrix protein concentration) on mesenchymal stem cell (MSC) spreading, proliferation and osteogenic differentiation. C3H10T1/2 cells were grown on type I collagen- or fibronectin-coated polyacrylamide hydrogels with tunable mechanical properties. Experimental conditions, which were defined according to central composite design, consisted of specific permutations of substrate stiffness (3-144 kPa) and adhesion protein concentration (7-520 microg/mL). Spreading area, BrdU incorporation and Runx2 nuclear translocation were quantified using high-content microscopy and modeled as mathematical functions of substrate stiffness and protein concentration. The resulting response surfaces revealed distinct patterns of protein-specific, substrate stiffness-dependent modulation of MSC proliferation and differentiation, demonstrating the advantage of statistical modeling in the detection and description of higher-order cellular responses. In a broader context, this approach can be adapted to study other types of cell-material interactions and can facilitate the efficient screening and optimization of substrate properties for applications involving cell-material interfaces. Copyright 2009 Elsevier Ltd. All rights reserved.

  13. The closer the relationship, the more the interaction on facebook? Investigating the case of Taiwan users.

    Science.gov (United States)

    Hsu, Chiung-Wen Julia; Wang, Ching-Chan; Tai, Yi-Ting

    2011-01-01

    This study argues for the necessity of applying offline contexts to social networking site research and the importance of distinguishing the relationship types of users' counterparts when studying Facebook users' behaviors. In an attempt to examine the relationship among users' behaviors, their counterparts' relationship types, and the users' perceived acquaintanceships after using Facebook, this study first investigated users' frequently used tools when interacting with different types of friends. Users tended to use less time- and effort-consuming and less privacy-concerned tools with newly acquired friends. This study further examined users' behaviors in terms of their closeness and intimacy and their perceived acquaintanceships toward four different types of friends. The study found that users gained more perceived acquaintanceships from less close friends with whom users have more frequent interaction but less intimate behaviors. As for closer friends, users tended to use more intimate activities to interact with them. However, these activities did not necessarily occur more frequently than the activities they employed with their less close friends. It was found that perceived acquaintanceships with closer friends were significantly lower than those with less close friends. This implies that Facebook is a mechanism for new friends, rather than close friends, to become more acquainted.

  14. Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

    International Nuclear Information System (INIS)

    Chatterjee, Anindita; Priyam, Amiya; Ghosh, Debasmita; Mondal, Somrita; Bhattacharya, Subhash C.; Saha, Abhijit

    2012-01-01

    Interactions of luminescence, water soluble ZnS nanoparticles (NPs) with flavins and glucose oxidase have been thoroughly investigated through optical spectroscopy. The photoluminescence of ZnS nanoparticles was quenched severely (∼60%) by riboflavin while other flavins such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) show quenching to different extents under analogous conditions. However, interestingly no effect in luminescence intensity of ZnS NPs was observed with protein bound flavins such as in glucose oxidase. Fluorescence lifetime measurement confirmed the quenching to be static in nature. Scavenging of photo-generated electron of ZnS nanoparticles by the flavin molecules may be attributed to the decrease in luminescence intensity. Quenching of ZnS nanoparticles with flavins follows the linear Stern–Volmer plot. The Stern–Volmer constants decreased in the following order: K S−V (Riboflavin)> K S−V (FAD)> K S−V (FMN). This interaction study could generate useful protocol for the fluorimetric determination of riboflavin (vitamin B 2 ) content and also riboflavin status in biological systems. - Highlights: ► Unique interaction specificity of ZnS nanoparticles with flavins has been explored. ► Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. ► FMN and FAD show quenching to different extents under analogous conditions. ► Fluorescence lifetime measurement confirmed the quenching to be static in nature. ► This study is useful for probing riboflavin in biological systems.

  15. Numerical investigation of two interacting parallel thruster-plumes and comparison to experiment

    Science.gov (United States)

    Grabe, Martin; Holz, André; Ziegenhagen, Stefan; Hannemann, Klaus

    2014-12-01

    Clusters of orbital thrusters are an attractive option to achieve graduated thrust levels and increased redundancy with available hardware, but the heavily under-expanded plumes of chemical attitude control thrusters placed in close proximity will interact, leading to a local amplification of downstream fluxes and of back-flow onto the spacecraft. The interaction of two similar, parallel, axi-symmetric cold-gas model thrusters has recently been studied in the DLR High-Vacuum Plume Test Facility STG under space-like vacuum conditions, employing a Patterson-type impact pressure probe with slot orifice. We reproduce a selection of these experiments numerically, and emphasise that a comparison of numerical results to the measured data is not straight-forward. The signal of the probe used in the experiments must be interpreted according to the degree of rarefaction and local flow Mach number, and both vary dramatically thoughout the flow-field. We present a procedure to reconstruct the probe signal by post-processing the numerically obtained flow-field data and show that agreement to the experimental results is then improved. Features of the investigated cold-gas thruster plume interaction are discussed on the basis of the numerical results.

  16. Wave-particle interaction and Hamiltonian dynamics investigated in a traveling wave tube

    International Nuclear Information System (INIS)

    Doveil, Fabrice; Macor, Alessandro

    2006-01-01

    For wave-particle interaction studies, the one-dimensional (1-D) beam-plasma system can be advantageously replaced by a Traveling Wave Tube (TWT). This led us to a detailed experimental analysis of the self-consistent interaction between unstable waves and a small either cold or warm beam. More recently, a test electron beam has been used to observe its non-self-consistent interaction with externally excited wave(s). The velocity distribution function of the electron beam is investigated with a trochoidal energy analyzer that records the beam energy distribution at the output of the TWT. An arbitrary waveform generator is used to launch a prescribed spectrum of waves along the slow wave structure (a 4 m long helix) of the TWT. The nonlinear synchronization of particles by a single wave responsible for Landau damping is observed. The resonant velocity domain associated to a single wave is also observed, as well as the transition to large-scale chaos when the resonant domains of two waves and their secondary resonances overlap leading to a typical 'devil's staircase' behavior. A new strategy for the control of chaos is tested

  17. Investigation on the toxic interaction of typical plasticizers with calf thymus DNA

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Xiaojing [School of Environmental Science and Engineering, China–America CRC for Environment & Health, Shandong University, 27# Shanda South Road, Jinan 250100, Shandong Province (China); Zong, Wansong, E-mail: gaocz@sdu.edu.cn [College of Population, Resources and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014 (China); Liu, Chunguang; Liu, Yang [School of Environmental Science and Engineering, China–America CRC for Environment & Health, Shandong University, 27# Shanda South Road, Jinan 250100, Shandong Province (China); Gao, Canzhu, E-mail: rutaoliu@sdu.edu.cn [School of Environmental Science and Engineering, China–America CRC for Environment & Health, Shandong University, 27# Shanda South Road, Jinan 250100, Shandong Province (China); Liu, Rutao [School of Environmental Science and Engineering, China–America CRC for Environment & Health, Shandong University, 27# Shanda South Road, Jinan 250100, Shandong Province (China)

    2015-05-15

    The interactions of typical plasticizers dimethyl phthalate (DMP), diethyl phthalate (DEP) and dibutyl phthalate (DBP) with calf thymus DNA (ctDNA) were investigated by fluorescence spectroscopic techniques and molecular modeling. Experimental results indicated that the characteristic fluorescence intensity of phthalic acid rose with the increase of DNA concentration; while the characteristic fluorescence intensities of plasticizers decreased with the increase of DNA concentration. Experiments on native and denatured DNA determined that plasticizers interacted with DNA both in groove and electrostatic binding mode. The molecular modeling results further illustrated that there is groove binding between them; hydrogen bonding and Van der Waals interactions were the main forces. With the extension of branched-chains, the binding effects between plasticizers and DNA were weakened, which could be related to the increased steric hindrance. - Highlights: • This work established the binding mode of plasticizers with DNA on molecular level. • The mechanism was explored by fluorescence spectroscopic and molecular docking methods. • There are two kinds of binding mode between DMP, DEP, DBP and DNA, electrostatic and groove. • With the branched chain extension, the binding effect of plasticizers and DNA has been weakened.

  18. Spectroscopic investigation on the interaction of titanate nanotubes with bovine serum albumin

    International Nuclear Information System (INIS)

    Zhao, L.Z.; Zhao, Y.S.; Teng, H.H.; Shi, S.Y.; Ren, B.X.

    2014-01-01

    In order to understand the transport mechanism and evaluate the biological safety of titanate nanotubes, the interactions of titanate nanotubes (TNTs) with bovine serum albumin (BSA) were investigated by applying spectroscopic methods under simulated physiological conditions. After taking into account the inner filter effect, the fluorescence intensity of BSA was found to be significantly enhanced by the presence of TNTs, indicating that the microenvironment of tryptophan and tyrosine residues in BSA became more hydrophobic. In addition, the absorption spectra of BSA showed a hyperchromic effect around 280 nm as the concentration of TNTs increased, suggesting that TNTs changed the microenvironment of the tryptophan and tyrosine residues. This is consistent with the results from fluorescence spectroscopy studies. However, circular dichroism spectroscopy revealed that no significant conformational change in BSA occurred during the interaction. We believe that Trp-213 was buried more compactly in the internal hydrophobic region, and hydrophobicity increased around Trp-134 with increasing TNTs concentration. From a spectroscopic point of view, this work elucidates the interaction mechanism of titanate nanotubes with BSA, and the methods used in this paper can also be applied to explore the molecular mechanism underlying toxicity of other nanomaterials. (authors)

  19. Computational investigation of large-scale vortex interaction with flexible bodies

    Science.gov (United States)

    Connell, Benjamin; Yue, Dick K. P.

    2003-11-01

    The interaction of large-scale vortices with flexible bodies is examined with particular interest paid to the energy and momentum budgets of the system. Finite difference direct numerical simulation of the Navier-Stokes equations on a moving curvilinear grid is coupled with a finite difference structural solver of both a linear membrane under tension and linear Euler-Bernoulli beam. The hydrodynamics and structural dynamics are solved simultaneously using an iterative procedure with the external structural forcing calculated from the hydrodynamics at the surface and the flow-field velocity boundary condition given by the structural motion. We focus on an investigation into the canonical problem of a vortex-dipole impinging on a flexible membrane. It is discovered that the structural properties of the membrane direct the interaction in terms of the flow evolution and the energy budget. Pressure gradients associated with resonant membrane response are shown to sustain the oscillatory motion of the vortex pair. Understanding how the key mechanisms in vortex-body interactions are guided by the structural properties of the body is a prerequisite to exploiting these mechanisms.

  20. Investigation of Plugging of Narrow Sodium Channels by Sodium and Carbon Dioxide Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sun Hee; Wi, Myung-Hwan; Min, Jae Hong; Kim, Tae-joon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    The supercritical CO{sub 2} Brayton cycle system is known to be a promising power conversion system for improving the efficiency and preventing the sodium water reaction (SWR) of the current SFR concept using a Rankine steam cycle. PCHEs are known to have potential for reducing the volume occupied by the sodium-to-CO{sub 2} exchangers as well as the heat exchanger mass relative to traditional shell-and-tube heat exchangers. Here, we report a study on a plugging test by the interaction of sodium and CO{sub 2} to investigate design parameters of sodium channels in the realistic operating conditions. We investigated a plugging test by an interaction of sodium and CO{sub 2} with different cross sectional areas of the sodium channels. It was found that the flow rate of sodium decreased earlier and faster with a narrower cross sectional area compared to a wider one. Our experimental results are expected to be used for determining the sodium channel areas of PCHEs.

  1. Investigation of structural responses of breakwaters for green water based on fluid-structure interaction analysis

    Directory of Open Access Journals (Sweden)

    Chi-Seung Lee

    2012-06-01

    Full Text Available In the present study, the structural response of breakwaters installed on container carriers against green water impact loads was numerically investigated on the basis of the fluid-structure interaction analysis. A series of numerical studies is carried out to induce breakwater collapse under such conditions, whereby a widely accepted fluid-structure interaction analysis technique is adopted to realistically consider the phenomenon of green water impact loads. In addition, the structural behaviour of these breakwaters under green water impact loads is investigated simultaneously throughout the transient analysis. A verification study of the numerical results is performed using data from actual collapse incidents of breakwaters on container carriers. On the basis of the results of a series of numerical analyses, the pressure distribution of green water was accurately predicted with respect to wave mass and velocity. It is expected that the proposed analytical methodology and predicted pressure distribution could be used as a practical guideline for the design of breakwaters on container carriers.

  2. Spectroscopic investigations of novel pharmaceuticals: Stability and resonant interaction with laser beam

    Science.gov (United States)

    Smarandache, Adriana; Boni, Mihai; Andrei, Ionut Relu; Handzlik, Jadwiga; Kiec-Kononowicz, Katarzyna; Staicu, Angela; Pascu, Mihail-Lucian

    2017-09-01

    This paper presents data about photophysics of two novel thio-hydantoins that exhibit promising pharmaceutical properties in multidrug resistance control. Time stability studies are necessary to establish the proper use of these compounds in different applications. As for their administration as drugs, it is imperative to know their shelf life, as well as storage conditions. At the same time, laser induced modified properties of the two new compounds are valuable to further investigate their specific interactions with other materials, including biological targets. The two new thio-hydantoins under generic names SZ-2 and SZ-7 were prepared as solutions in dimethyl sulfoxide at different concentrations, as well as in deionised water. For the stability assay they were kept in various light/temperature conditions up to 60 days. The stability was estimates based on UV-vis absorption measurements. The samples in bulk shape were exposed different time intervals to laser radiation emitted at 266 nm as the fourth harmonic of a Nd:YAG laser. The resonant interaction of the studied compounds with laser beams was analysed through spectroscopic methods UV-vis and FTIR absorption, as well as laser induced fluorescence spectroscopy. As for stability assay, only solutions kept in dark at 4 °C have preserved the absorption characteristics, considering the cumulated measuring errors, less than one week. The vibrational changes that occur in their FTIR and modified fluorescence spectra upon laser beam exposure are also discussed. A result of the experimental analysis is that modifications are induced in molecular structures of the investigated compounds by resonant interaction with laser radiation. This fact evidences that the molecules are photoreactive and their characteristics might be shaped through controlled laser radiation exposure using appropriate protocols. This conclusion opens many opportunities both in the biomedical field, but also in other industrial activities

  3. Spectroscopic investigation of Bovine Liver Catalase interactions with a novel phen-imidazole derivative of platinum.

    Science.gov (United States)

    Ghobadi, Roohollah; Divsalar, Adeleh; Harifi-Mood, Ali Reza; Saboury, Ali Akbar

    2018-02-01

    Successful clinical experience of using cisplatin and its derivatives in cancer therapy has encouraged scientists to synthesize new metal complexes with the aim of interacting with special targets such as proteins In this regard, biological effects of [Pt(FIP)(Phen)](NO 3 ) 2 compound which contains a novel phen-imidazole ligand, FIP, was investigated on bovine liver catalase (BLC) structure and function. Various spectroscopic methods such as UV-visible, fluorescence, and circular dichroism (CD) were applied at two temperatures 25 and 37°C for kinetics and structural studies. As a consequence, the enzymatic activity decreased slightly with increasing the platinum compound's concentration up to 30 μM and then remained constant at near 80% after this concentration. On the other hand, the fluorescence quenching measurements revealed that despite slight changes in activity, catalase experiences notable alterations in three-dimensional environment around the chromophores of the enzyme structure with increasing platinum complex concentration. Moreover, quenching data showed that BLC has two binding sites for Pt complex and hydrogen bonding interactions play a major role in the binding process. Furthermore, CD spectroscopy data showed that Pt(II) complex induces significant decrease in α-helix content of the secondary structure of BLC, but notable increase in random coil proportion accompanying a slight decrease in β-sheet content. All in all, hydrogen bonding interactions which are mainly involved in the binding process of the novel phen-imidazole compound to BLC significantly alter the protein structure but slightly change its function. This might be a promising outcome for chemotherapists and medicinal chemists to investigate in vivo properties of this novel metal complex with significant binding tendency to a macromolecule in the low concentrations without decreasing its intrinsic function.

  4. Investigation on the toxic interaction of superparamagnetic iron oxide nanoparticles with catalase

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Zehua [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Liu, Hongwei [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085 (China); Hu, Xinxin; Song, Wei [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China); Liu, Rutao, E-mail: rutaoliu@sdu.edu.cn [Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, China–America CRC for Environment and Health, Shandong Province, Shandong University, 27# Shanda South Road, Jinan 250100 (China)

    2015-03-15

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for various applications in targeted drug delivery and magnetic resonance imaging. Given their clinical relevance, there is a need to understand these particles' potential cytotoxic effects and possible mechanisms of cytotoxicity. Using a variety of spectroscopic techniques, we investigated the interaction of SPIONs with catalase (CAT) in an aqueous environment. Catalase is an important enzyme that protects cells and tissues from oxidative damage by reactive oxygen species (ROS). Therefore, in this work, CAT served as a model protein for examining the physiological effects of SPIONs due to is function in eliminating H{sub 2}O{sub 2}. Synchronous fluorescence spectroscopy results showed that SPIONs have little effect on tryptophan residues in CAT. Data from circular dichroism (CD) and UV–vis spectroscopies showed that CAT α-helical content decreased from 32.4% to 29.1% in the presence of SPIONs. Moreover, a ca. 10% decrease in CAT activity was observed in the presence of SPIONs at a 20:1 particle:protein ratio. These results show that SPIONs can interact with proteins to alter both their structure and function. Further studies with CAT or other toxicologically relevant enzymes may be used for elucidating the mechanisms of SPION cytotoxicity. - Highlights: • This work established the binding mode of SPIONs with CAT on molecular level. • The interaction mechanism was explored by multiple spectroscopic techniques. • SPIONs can loosen the skeleton of protein and increase the exposure of amide moieties in the hydrophobic pocket. • SPIONs can inhibit CAT activity and trigger conformational changes in CAT.

  5. Investigation on the toxic interaction of superparamagnetic iron oxide nanoparticles with catalase

    International Nuclear Information System (INIS)

    Yu, Zehua; Liu, Hongwei; Hu, Xinxin; Song, Wei; Liu, Rutao

    2015-01-01

    Superparamagnetic iron oxide nanoparticles (SPIONs) have been investigated for various applications in targeted drug delivery and magnetic resonance imaging. Given their clinical relevance, there is a need to understand these particles' potential cytotoxic effects and possible mechanisms of cytotoxicity. Using a variety of spectroscopic techniques, we investigated the interaction of SPIONs with catalase (CAT) in an aqueous environment. Catalase is an important enzyme that protects cells and tissues from oxidative damage by reactive oxygen species (ROS). Therefore, in this work, CAT served as a model protein for examining the physiological effects of SPIONs due to is function in eliminating H 2 O 2 . Synchronous fluorescence spectroscopy results showed that SPIONs have little effect on tryptophan residues in CAT. Data from circular dichroism (CD) and UV–vis spectroscopies showed that CAT α-helical content decreased from 32.4% to 29.1% in the presence of SPIONs. Moreover, a ca. 10% decrease in CAT activity was observed in the presence of SPIONs at a 20:1 particle:protein ratio. These results show that SPIONs can interact with proteins to alter both their structure and function. Further studies with CAT or other toxicologically relevant enzymes may be used for elucidating the mechanisms of SPION cytotoxicity. - Highlights: • This work established the binding mode of SPIONs with CAT on molecular level. • The interaction mechanism was explored by multiple spectroscopic techniques. • SPIONs can loosen the skeleton of protein and increase the exposure of amide moieties in the hydrophobic pocket. • SPIONs can inhibit CAT activity and trigger conformational changes in CAT

  6. Investigating the Neural Correlates of Emotion–Cognition Interaction Using an Affective Stroop Task

    Directory of Open Access Journals (Sweden)

    Nora M. Raschle

    2017-09-01

    Full Text Available The human brain has the capacity to integrate various sources of information and continuously adapts our behavior according to situational needs in order to allow a healthy functioning. Emotion–cognition interactions are a key example for such integrative processing. However, the neuronal correlates investigating the effects of emotion on cognition remain to be explored and replication studies are needed. Previous neuroimaging studies have indicated an involvement of emotion and cognition related brain structures including parietal and prefrontal cortices and limbic brain regions. Here, we employed whole brain event-related functional magnetic resonance imaging (fMRI during an affective number Stroop task and aimed at replicating previous findings using an adaptation of an existing task design in 30 healthy young adults. The Stroop task is an indicator of cognitive control and enables the quantification of interference in relation to variations in cognitive load. By the use of emotional primes (negative/neutral prior to Stroop task performance, an emotional variation is added as well. Behavioral in-scanner data showed that negative primes delayed and disrupted cognitive processing. Trials with high cognitive demand furthermore negatively influenced cognitive control mechanisms. Neuronally, the emotional primes consistently activated emotion-related brain regions (e.g., amygdala, insula, and prefrontal brain regions while Stroop task performance lead to activations in cognition networks of the brain (prefrontal cortices, superior temporal lobe, and insula. When assessing the effect of emotion on cognition, increased cognitive demand led to decreases in neural activation in response to emotional stimuli (negative > neutral within prefrontal cortex, amygdala, and insular cortex. Overall, these results suggest that emotional primes significantly impact cognitive performance and increasing cognitive demand leads to reduced neuronal activation in

  7. Investigation on Melt-Structure-Water Interactions (MSWI) during severe accidents

    Energy Technology Data Exchange (ETDEWEB)

    Sehgal, B.R.; Yang, Z.L.; Dinh, T.N.; Nourgaliev, R.R.; Bui, V.A.; Haraldsson, H.O.; Li, H.X.; Konovakhin, M.; Paladino, D.; Leung, W.H [Royal Inst. of Tech., Stockholm (Sweden). Div. of Nuclear Power Safety

    1999-08-01

    This report is the final report for the work performed in 1998 in the research project Melt Structure Water Interactions (MSWI), under the auspices of the APRI Project, jointly funded by SKI, HSK, USNRC and the Swedish and Finnish power companies. The present report describes results of advanced analytical and experimental studies concerning melt-water-structure interactions during the course of a hypothetical severe core meltdown accident in a light water reactor (LWR). Emphasis has been placed on phenomena and properties which govern the fragmentation and breakup of melt jets and droplets, melt spreading and coolability, and thermal and mechanical loadings of a pressure vessel during melt-vessel interaction. Many of the investigations performed in support of this project have produced papers which have been published in the proceedings of technical meetings. A short summary of the results achieved in these papers is provided in this overview. Both experimental and analytical studies were performed to improve knowledge about phenomena of melt-structure-water interactions. We believe that significant technical advances have been achieved during the course of these studies. It was found that: the solidification has a strong effect on the drop deformation and breakup. Initially appearing at the drop surface and, later, thickening inwards, the solid crust layer dampens the instability waves on the drop surface and, therefore, hinders drop deformation and breakup. The drop thermal properties also affect the thermal behavior of the drop and, therefore, have impact on its deformation behavior. The jet fragmentation process is a function of many related phenomena. The fragmentation rate depends not only on the traditional parameters, e.g. the Weber number, but also on the melt physical properties, which change as the melt cools down from the liquidus to the solidus temperature. Additionally, the crust formed on the surface of the melt jet will also reduce the propensity

  8. Investigation on Melt-Structure-Water Interactions (MSWI) during severe accidents

    International Nuclear Information System (INIS)

    Sehgal, B.R.; Yang, Z.L.; Dinh, T.N.; Nourgaliev, R.R.; Bui, V.A.; Haraldsson, H.O.; Li, H.X.; Konovakhin, M.; Paladino, D.; Leung, W.H

    1999-08-01

    This report is the final report for the work performed in 1998 in the research project Melt Structure Water Interactions (MSWI), under the auspices of the APRI Project, jointly funded by SKI, HSK, USNRC and the Swedish and Finnish power companies. The present report describes results of advanced analytical and experimental studies concerning melt-water-structure interactions during the course of a hypothetical severe core meltdown accident in a light water reactor (LWR). Emphasis has been placed on phenomena and properties which govern the fragmentation and breakup of melt jets and droplets, melt spreading and coolability, and thermal and mechanical loadings of a pressure vessel during melt-vessel interaction. Many of the investigations performed in support of this project have produced papers which have been published in the proceedings of technical meetings. A short summary of the results achieved in these papers is provided in this overview. Both experimental and analytical studies were performed to improve knowledge about phenomena of melt-structure-water interactions. We believe that significant technical advances have been achieved during the course of these studies. It was found that: the solidification has a strong effect on the drop deformation and breakup. Initially appearing at the drop surface and, later, thickening inwards, the solid crust layer dampens the instability waves on the drop surface and, therefore, hinders drop deformation and breakup. The drop thermal properties also affect the thermal behavior of the drop and, therefore, have impact on its deformation behavior. The jet fragmentation process is a function of many related phenomena. The fragmentation rate depends not only on the traditional parameters, e.g. the Weber number, but also on the melt physical properties, which change as the melt cools down from the liquidus to the solidus temperature. Additionally, the crust formed on the surface of the melt jet will also reduce the propensity

  9. Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

    Energy Technology Data Exchange (ETDEWEB)

    Chatterjee, Anindita; Priyam, Amiya; Ghosh, Debasmita; Mondal, Somrita [UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8, Bidhannagar, Kolkata 700098 (India); Bhattacharya, Subhash C. [Department of Chemistry, Jadavpur University, Kolkata 700032 (India); Saha, Abhijit, E-mail: abhijit@alpha.iuc.res.in [UGC-DAE Consortium for Scientific Research, Kolkata Centre, III/LB-8, Bidhannagar, Kolkata 700098 (India)

    2012-03-15

    Interactions of luminescence, water soluble ZnS nanoparticles (NPs) with flavins and glucose oxidase have been thoroughly investigated through optical spectroscopy. The photoluminescence of ZnS nanoparticles was quenched severely ({approx}60%) by riboflavin while other flavins such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) show quenching to different extents under analogous conditions. However, interestingly no effect in luminescence intensity of ZnS NPs was observed with protein bound flavins such as in glucose oxidase. Fluorescence lifetime measurement confirmed the quenching to be static in nature. Scavenging of photo-generated electron of ZnS nanoparticles by the flavin molecules may be attributed to the decrease in luminescence intensity. Quenching of ZnS nanoparticles with flavins follows the linear Stern-Volmer plot. The Stern-Volmer constants decreased in the following order: K{sub S-V} (Riboflavin)> K{sub S-V} (FAD)> K{sub S-V} (FMN). This interaction study could generate useful protocol for the fluorimetric determination of riboflavin (vitamin B{sub 2}) content and also riboflavin status in biological systems. - Highlights: Black-Right-Pointing-Pointer Unique interaction specificity of ZnS nanoparticles with flavins has been explored. Black-Right-Pointing-Pointer Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. Black-Right-Pointing-Pointer FMN and FAD show quenching to different extents under analogous conditions. Black-Right-Pointing-Pointer Fluorescence lifetime measurement confirmed the quenching to be static in nature. Black-Right-Pointing-Pointer This study is useful for probing riboflavin in biological systems.

  10. Investigating the Interaction of Fe Nanoparticles with Lysozyme by Biophysical and Molecular Docking Studies.

    Directory of Open Access Journals (Sweden)

    Zahra Aghili

    Full Text Available Herein, the interaction of hen egg white lysozyme (HEWL with iron nanoparticle (Fe NP was investigated by spectroscopic and docking studies. The zeta potential analysis revealed that addition of Fe NP (6.45±1.03 mV to HEWL (8.57±0.54 mV can cause to greater charge distribution of nanoparticle-protein system (17.33±1.84 mV. In addition, dynamic light scattering (DLS study revealed that addition of Fe NP (92.95±6.11 nm to HEWL (2.68±0.37 nm increases suspension potential of protein/nanoparticle system (51.17±3.19 nm. Fluorescence quenching studies reveled that both static and dynamic quenching mechanism occur and hydrogen bond and van der Waals interaction give rise to protein-NP system. Synchronous fluorescence spectroscopy of HEWL in the presence of Fe NP showed that the emission maximum wavelength of tryptophan (Trp residues undergoes a red-shift. ANS fluorescence data indicated a dramatic exposure of hydrophobic residues to the solvent. The considerable reduction in melting temperature (T(m of HEWL after addition of Fe NP determines an unfavorable interaction system. Furthermore circular dichoroism (CD experiments demonstrated that, the secondary structure of HEWL has not changed with increasing Fe NP concentrations; however, some conformational changes occur in tertiary structure of HEWL. Moreover, protein-ligand docking study confirmed that the Fe NP forms hydrogen bond contacts with HEWL.

  11. FT-IR and X-ray spectroscopic investigations of Na-diclofenac-cyclodextrins interactions

    Science.gov (United States)

    Bratu, I.; Astilean, S.; Ionesc, Corina; Indrea, E.; Huvenne, J. P.; Legrand, P.

    1998-01-01

    The association of DCF-Na (the salt of the 2-[(2,6-dichlorophenyl)amino]-phenyl-acetic acid) with β-CD (cyclodextrin) in some therapeutic formulas can contribute to the optimisation of the physico-chemical and pharmaceutical properties of the parent drug. The understanding of the interaction between DCF with β-CD represents the objective of this study. FT-IR spectroscopy is one of the methods which clarify the nature of these interactions in complexes of such type. Therefore the changes in FT-IR spectra of binary dispersed systems DCF/ β-CD in physical mixture and coprecipitate from methanol (molar ratios: 1/1, 1/2, 2/3, 3/4, 7/4) were analysed. The analysis of the broadening of the X-ray powder diffraction line has been applied to investigate the average effective crystallite size, the mean square of the microstrain caused by distortions within β-CD crystallite and the fault probability in the binary dispersed DCF/ β-CD coprecipitate system.

  12. Investigation of hydrogen isotopes interaction processes with lithium under neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Zaurbekova, Zhanna, E-mail: zaurbekova@nnc.kz [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Skakov, Mazhyn; Ponkratov, Yuriy; Kulsartov, Timur; Gordienko, Yuriy; Tazhibayeva, Irina; Baklanov, Viktor; Barsukov, Nikolay [Institute of Atomic Energy, National Nuclear Center of RK, Kurchatov (Kazakhstan); Chikhray, Yevgen [Institute of Experimental and Theoretical Physics of Kazakh National University, Almaty (Kazakhstan)

    2016-11-01

    Highlights: • The experiments on study of helium and tritium generation and release processes under neutron irradiation from lithium saturated with deuterium are described in paper. ​ • The values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation is calculated. • It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide. - Abstract: The paper describes the experiments on study of helium and tritium generation and release processes from lithium saturated with deuterium under neutron irradiation (in temperature range from 473 to 773 K). The diagrams of two reactor experiments show the time dependences of helium, DT, T{sub 2}, and tritium water partial pressures changes in experimental chamber with investigated lithium sample. According to experimental results, the values of relative tritium and helium yield from lithium sample at different levels of neutron irradiation were calculated. The time dependences of relative tritium and helium yield from lithium sample were plotted. It was concluded that the main affecting process on tritium release from lithium is its interaction with lithium atoms with formation of lithium tritide.

  13. Investigation of Unsteady Flow Interaction Between an Ultra-Compact Inlet and a Transonic Fan

    Science.gov (United States)

    Hah, Chunill; Rabe, Douglas; Scribben, Angie

    2015-01-01

    In the present study, unsteady flow interaction between an ultra-compact inlet and a transonic fan stage is investigated. Future combat aircraft require ultra-compact inlet ducts as part of an integrated, advanced propulsion system to improve air vehicle capability and effectiveness to meet future mission needs. The main purpose of the study is to advance the current understanding of the flow interaction between two different ultra-compact inlets and a transonic fan for future design applications. Both URANS and LES approaches are used to calculate the unsteady flow field and are compared with the available measured data. The present study indicates that stall inception is mildly affected by the distortion pattern generated by the inlet with the current test set-up. The numerical study indicates that the inlet distortion pattern decays significantly before it reaches the fan face for the current configuration. Numerical results with a shorter distance between the inlet and fan show that counter-rotating vortices near the rotor tip due to the serpentine diffuser affects fan characteristics significantly.

  14. CO interaction with Cu(I)-MCM-22 zeolite: density function theory investigation

    International Nuclear Information System (INIS)

    Viet Thang Ho; Petr Nachtigall

    2014-01-01

    MCM-22 zeolite has been widely used in many applications for catalysis and adsorption. Especially, this material exchanged with Cu + cation (Cu(I)-MCM-22) is an active catalyst in green chemical reaction, such as decomposition of NO and N 2 O. The local geometry of Cu + in vicinity of Al (III) replacement in six different Si (IV) sites and CO interaction with the most stable Cu + in each Al site were explored using periodic density functional theory (DFT) method. Th CO stretching frequencies were computed applying the ω/r scaling method in which frequencies were determined at high quantum level (couple cluster) and CO bond length calculated at DFT level. The results showed that Cu + cation located in the channel wall position and intersection position coordinated with 3 or 2 framework oxygen atoms, respectively, before CO adsorption and Cu + cation coordinated with 2 framework oxygen atoms after CO adsorption. The interaction energies between CO and Cu + cation were in range -148 to -195 kJ/mol -1 and CO frequencies exhibit two peak at 2151 and 2159 cm -1 in good agreement with experimental data. This investigation allows to understand the Cu + location in MCM-22 and CO adsorption in Cu(I)-MCM-22 zeolite. (author)

  15. Diagnostic setup for investigation of plasma wall interactions at Wendelstein 7-X

    International Nuclear Information System (INIS)

    Neubauer, Olaf; Biel, Wolfgang; Czymek, Guntram; Denner, Peter; Effenberg, Florian; Krämer-Flecken, Andreas; Liang, Yunfeng; Marchuk, Oleksandr; Offermanns, Guido; Rack, Michael; Samm, Ulrich; Schmitz, Oliver; Schweer, Bernd; Terra, Alexis

    2015-01-01

    Graphical abstract: - Highlights: • We are investigating plasma wall interactions at Wendelstein 7-X stellarator. • Steady state operation and island divertor are unique. • We are developing diagnostics for divertor plasma and plasma facing surfaces. • A multi-purpose fast manipulator allows for exposure of probes and samples. • Versatile endoscopes allow for local divertor spectroscopy from IR to UV. - Abstract: Wendelstein 7-X being the most advanced stellarator is currently prepared for commissioning at Greifswald. Forschungszentrum Jülich is preparing a research programme in the field of plasma wall interactions (PWI) by developing a dedicated set of diagnostic systems. The specific interest at Wendelstein 7-X is to understand PWI processes in presence of a 3D plasma boundary of an island divertor. Furthermore, for the first time steady state plasma at high density and low temperature in the divertor region will be available. Since PWI only could be understood in conjunction with the edge plasma properties the aim of the setup is to observe both the edge plasma as well as surface processes. For optimum combination of different diagnostic methods the edge diagnostic systems are aligned toroidally along one out of five magnetic islands. Main systems are a multipurpose fast probe manipulator, two gas boxes in opposite divertor modules together with two endoscopes each observing the divertor regions, a poloidal correlation reflectometer, a dispersion interferometer in the divertor, and VUV and X-ray spectroscopy in the plasma core. The concept of the diagnostic setup is presented in this paper.

  16. Diagnostic setup for investigation of plasma wall interactions at Wendelstein 7-X

    Energy Technology Data Exchange (ETDEWEB)

    Neubauer, Olaf, E-mail: o.neubauer@fz-juelich.de [Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Biel, Wolfgang; Czymek, Guntram; Denner, Peter [Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Effenberg, Florian [University Wisconsin–Madison, Madison, WI (United States); Krämer-Flecken, Andreas; Liang, Yunfeng; Marchuk, Oleksandr; Offermanns, Guido; Rack, Michael; Samm, Ulrich [Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany); Schmitz, Oliver [University Wisconsin–Madison, Madison, WI (United States); Schweer, Bernd [Laboratoire de Physique des Plasmas – Laboratorium voor Plasmafysica, ERM/KMS, 1000 Brussels (Belgium); Terra, Alexis [Institute of Energy and Climate Research, Forschungszentrum Jülich GmbH, D-52425 Jülich (Germany)

    2015-10-15

    Graphical abstract: - Highlights: • We are investigating plasma wall interactions at Wendelstein 7-X stellarator. • Steady state operation and island divertor are unique. • We are developing diagnostics for divertor plasma and plasma facing surfaces. • A multi-purpose fast manipulator allows for exposure of probes and samples. • Versatile endoscopes allow for local divertor spectroscopy from IR to UV. - Abstract: Wendelstein 7-X being the most advanced stellarator is currently prepared for commissioning at Greifswald. Forschungszentrum Jülich is preparing a research programme in the field of plasma wall interactions (PWI) by developing a dedicated set of diagnostic systems. The specific interest at Wendelstein 7-X is to understand PWI processes in presence of a 3D plasma boundary of an island divertor. Furthermore, for the first time steady state plasma at high density and low temperature in the divertor region will be available. Since PWI only could be understood in conjunction with the edge plasma properties the aim of the setup is to observe both the edge plasma as well as surface processes. For optimum combination of different diagnostic methods the edge diagnostic systems are aligned toroidally along one out of five magnetic islands. Main systems are a multipurpose fast probe manipulator, two gas boxes in opposite divertor modules together with two endoscopes each observing the divertor regions, a poloidal correlation reflectometer, a dispersion interferometer in the divertor, and VUV and X-ray spectroscopy in the plasma core. The concept of the diagnostic setup is presented in this paper.

  17. Investigation of corner shock boundary layer interactions to understand inlet unstart

    Science.gov (United States)

    Funderburk, Morgan

    2015-11-01

    Inlet unstart is a detrimental phenomenon in dual-mode ramjet/scramjet engines that causes severe loss of thrust, large transient structural load, and potentially a loss of the aircraft. In order to analyze the effects that the corner shock boundary layer interaction (SBLI) has on initiating and perpetuating inlet unstart, a qualitative and quantitative investigation into mean and dynamic features of corner SBLI at various Mach numbers is made. Surface streakline visualization showed that the corner SBLI is highly three-dimensional with a dominant presence of corner separation vortex. Further, the peak r.m.s. pressure was located at the periphery of corner separation vortex, suggesting that the unsteady loading is caused by the corner vortex. Power spectral densities of wall-pressure fluctuations in the peak r.m.s. location were analyzed in order to characterize the dominant frequencies of oscillation of the flow structures and to unravel the dynamic interactions between them in order to expand the operating margin of future hypersonic air breathing vehicles.

  18. Investigation of thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles

    International Nuclear Information System (INIS)

    Pustovalov, V K; Astafyeva, L G

    2013-01-01

    Metallic nanoparticles have been actively investigated in recent years by different optical and laser methods with the purpose of their applications in optoelectronics and photonics, chemistry, laser nanobiomedicine, optical diagnostics, and other fields. A major role among metallic nanoparticles is played by nanoparticles from the noble metals (silver, gold, etc). These particles have unique plasmonic properties (resonances in the range of wavelength 400–540 nm), which can be used for the absorption, scattering and transformation of laser energy. Analysis of the thermo-optical characteristics of the interaction processes of laser radiation with silver nanoparticles is carried out, taking into account absorption, scattering and extinction of laser radiation by nanoparticles, as well as the thermo-optical and other properties of nanoparticles. Estimations are made of the influence of these nanoparticle properties on the possible results of laser radiation interaction with silver nanoparticles, including heating, heat exchange, possible melting and evaporation, and processes in the ambient media. These results can be used in laser processing of silver nanoparticles and their applications in laser nanomedicine. (paper)

  19. Investigation of the Interaction between Perovskite Films with Moisture via in Situ Electrical Resistance Measurement.

    Science.gov (United States)

    Hu, Long; Shao, Gang; Jiang, Tao; Li, Dengbing; Lv, Xinlin; Wang, Hongya; Liu, Xinsheng; Song, Haisheng; Tang, Jiang; Liu, Huan

    2015-11-18

    Organometal halide perovskites have recently emerged as outstanding semiconductors for solid-state optoelectronic devices. Their sensitivity to moisture is one of the biggest barriers to commercialization. In order to identify the effect of moisture in the degradation process, here we combined the in situ electrical resistance measurement with time-resolved X-ray diffraction analysis to investigate the interaction of CH3NH3PbI(3-x)Cl(x) perovskite films with moisture. Upon short-time exposure, the resistance of the perovskite films decreased and it could be fully recovered, which were ascribed to a mere chemisorption of water molecules, followed by the reversible hydration into CH3NH3PbI(3-x)Cl(x)·H2O. Upon long-time exposure, however, the resistance became irreversible due to the decomposition into PbI2. The results demonstrated the formation of monohydrated intermediate phase when the perovskites interacted with moisture. The role of moisture in accelerating the thermal degradation at 85 °C was also demonstrated. Furthermore, our study suggested that the perovskite films with fewer defects may be more inherently resistant to moisture.

  20. Mathematical investigation of tsunami-like long waves interaction with submerge dike of different thickness

    Science.gov (United States)

    Zhiltsov, Konstantin; Kostyushin, Kirill; Kagenov, Anuar; Tyryshkin, Ilya

    2017-11-01

    This paper presents a mathematical investigation of the interaction of a long tsunami-type wave with a submerge dike. The calculations were performed by using the freeware package OpenFOAM. Unsteady two-dimensional Navier-Stokes equations were used for mathematical modeling of incompressible two-phase medium. The Volume of Fluid (VOF) method is used to capture the free surface of a liquid. The effects caused by long wave of defined amplitude motion through a submerged dike of varying thickness were discussed in detail. Numerical results show that after wave passing through the barrier, multiple vortex structures were formed behind. Intensity of vortex depended on the size of the barrier. The effectiveness of the submerge barrier was estimated by evaluating the wave reflection and transmission coefficients using the energy integral method. Then, the curves of the dependences of the reflection and transmission coefficients were obtained for the interaction of waves with the dike. Finally, it was confirmed that the energy of the wave could be reduced by more than 50% when it passed through the barrier.

  1. Photochemistry of ethylene: A multireference configuration interaction investigation of the excited-state energy surfaces

    International Nuclear Information System (INIS)

    Barbatti, M.; Paier, J.; Lischka, H.

    2004-01-01

    Multireference configuration interaction with singles and doubles (MR-CISD) calculations have been performed for the optimization of conical intersections and stationary points on the ethylene excited-state energy surfaces using recently developed methods for the computation of analytic gradients and nonadiabatic coupling terms. Basis set dependence and the effect of various choices of reference spaces for the MR-CISD calculations have been investigated. The crossing seam between the S 0 and S 1 states has been explored in detail. This seam connects all conical intersections presently known for ethylene. Major emphasis has been laid on the hydrogen-migration path. Starting in the V state of twisted-orthogonal ethylene, a barrierless path to ethylidene was found. The feasibility of ethylidene formation will be important for the explanation of the relative yield of cis and trans H 2 elimination

  2. Protein-ligand interactions investigated by thermal shift assays (TSA) and dual polarization interferometry (DPI).

    Science.gov (United States)

    Grøftehauge, Morten K; Hajizadeh, Nelly R; Swann, Marcus J; Pohl, Ehmke

    2015-01-01

    Over the last decades, a wide range of biophysical techniques investigating protein-ligand interactions have become indispensable tools to complement high-resolution crystal structure determinations. Current approaches in solution range from high-throughput-capable methods such as thermal shift assays (TSA) to highly accurate techniques including microscale thermophoresis (MST) and isothermal titration calorimetry (ITC) that can provide a full thermodynamic description of binding events. Surface-based methods such as surface plasmon resonance (SPR) and dual polarization interferometry (DPI) allow real-time measurements and can provide kinetic parameters as well as binding constants. DPI provides additional spatial information about the binding event. Here, an account is presented of new developments and recent applications of TSA and DPI connected to crystallography.

  3. Investigation of the neutron-proton-interaction in the energy range from 20 to 50 MEV

    International Nuclear Information System (INIS)

    Wilczynski, J.

    1984-07-01

    In the framework of the investigation of the isospin singlet part of the nucleon-nucleon-interaction in the energy range below 100 MeV two experiments were conducted, which were selected by sensitivity calculations. At the Karlsruhe polarized neutron facility POLKA the analyzing powers Asub(y) and Asub(yy) of the elastic n vector-p- and n vector-p vector-scattering were measured in the energy range from 20 to 50 MeV. The results of this epxeriment are compared to older data. In the energy range from 20 to 50 MeV the new data were analyzed together with other selected data of the nucleon-nucleon-system in phase shift analyses. The knowledge of the isospin singlet phase shifts 1 P 1 and 3 D 3 was improved by the new data. (orig./HSI) [de

  4. The interaction between 4-aminoantipyrine and bovine serum albumin: Multiple spectroscopic and molecular docking investigations

    International Nuclear Information System (INIS)

    Teng Yue; Liu Rutao; Li Chao; Xia Qing; Zhang Pengjun

    2011-01-01

    4-Aminoantipyrine (AAP) is widely used in the pharmaceutical industry, in biochemical experiments and in environmental monitoring. AAP as an aromatic pollutant in the environment poses a great threat to human health. To evaluate the toxicity of AAP at the protein level, the effects of AAP on bovine serum albumin (BSA) were investigated by multiple spectroscopic techniques and molecular modeling. After the inner filter effect was eliminated, the experimental results showed that AAP effectively quenched the intrinsic fluorescence of BSA via static quenching. The number of binding sites, the binding constant, the thermodynamic parameters and binding subdomain were measured, and indicated that AAP could spontaneously bind with BSA on subdomain IIIA through electrostatic forces. Molecular docking results revealed that AAP interacted with the Glu 488 and Glu 502 residues of BSA. Furthermore, the conformation of BSA was demonstrably changed in the presence of AAP. The skeletal structure of BSA loosened, exposing internal hydrophobic aromatic ring amino acids and peptide strands to the solution.

  5. Fluorescence spectroscopic investigation of the interaction of citrinin with native and chemically modified cyclodextrins

    Energy Technology Data Exchange (ETDEWEB)

    Poór, Miklós, E-mail: poor.miklos@pte.hu [Department of Pharmacology and Pharmacotherapy, Toxicology Section, University of Pécs, Szigeti út 12, Pécs H-7624 (Hungary); Matisz, Gergely; Kunsági-Máté, Sándor [Department of General and Physical Chemistry, University of Pécs, Ifjúság útja 6, Pécs H-7624 (Hungary); János Szentágothai Research Center, Ifjúság útja 20, Pécs H-7624 (Hungary); Derdák, Diána [Department of General and Physical Chemistry, University of Pécs, Ifjúság útja 6, Pécs H-7624 (Hungary); Szente, Lajos [CycloLab Cyclodextrin Research & Development Laboratory Ltd., Illatos út 7, Budapest H-1097 (Hungary); and others

    2016-04-15

    Citrinin (CIT) is a nephrotoxic mycotoxin produced by several Aspergillus, Penicillium and Monascus species. CIT is unavoidable contaminant of different foods and drinks due to its wide occurrence and high thermal stability. For this reason, development of new, more sensitive analytical methods and decontamination strategies has high importance. In our study, the complex formation of CIT with native and chemically modified cyclodextrins was investigated using fluorescence spectroscopy. Furthermore, thermodynamic and molecular modeling studies were also performed for the deeper understanding of these host-guest interactions. Our results show that among the tested compounds methylated β-cyclodextrins form the most stable complexes with CIT and these derivatives cause the highest fluorescence enhancement of CIT as well. These observations recommend that some of the chemically modified derivatives show more favourable properties than the native cyclodextrin, and suggesting more promising analytical applicability and higher affinity as potential toxin binders.

  6. Environmental Stress Responses and Biological Interactions Investigated in the Drosophila Model System

    DEFF Research Database (Denmark)

    Ørsted, Michael

    on their ability to respond on a behavioral, physiological, morphological and/or evolutionary level according to the environmental cues. At the same time, if populations are small and fragmented, and have limited gene flow, environmental change and environmental stress might interact with intrinsic genetic stress...... such as inbreeding and genetic drift, which can exacerbate the effects of one or more environmental stresses. Furthermore, inbred populations often have low genetic variation that might constrain evolutionary responses to rapidly changing environments. This thesis investigates how, and to what extent, insect model......When organisms are faced with changes in their environment, they are forced to respond, if they are to maintain optimal function. Especially ectotherms must deal with environmental changes in e.g. temperature on a regular basis, and thus their survival and reproductive success depend...

  7. Investigation of fracture-matrix interaction: Preliminary experiments in a simple system

    International Nuclear Information System (INIS)

    Foltz, S.D.

    1992-01-01

    Paramount to the modeling of unsaturated flow and transport through fractured porous media is a clear understanding of the processes controlling fracture-matrix interaction. As a first step toward such an understanding, two preliminary experiments have been performed to investigate the influence of matrix imbibition on water percolation through unsaturated fractures in the plane normal to the fracture. Test systems consisted of thin slabs of either tuff or an analog material cut by a single vertical fracture into which a constant fluid flux was introduced. Transient moisture content and solute concentration fields were imaged by means of x-ray absorption. Flow fields associated with the two different media were significantly different owing to differences in material properties relative to the imposed flux. Richards' equation was found to be a valid means of modeling the imbibition of water into the tuff matrix from a saturated fracture for the current experiment

  8. Aircraft-based investigation of Dynamics-Aerosol-Chemistry-Cloud Interactions in Southern West Africa

    Science.gov (United States)

    Flamant, Cyrille

    2017-04-01

    The EU-funded project DACCIWA (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa, http://www.dacciwa.eu) is investigating the relationship between weather, climate and air pollution in southern West Africa. The air over the coastal region of West Africa is a unique mixture of natural and anthropogenic gases, liquids and particles, emitted in an environment, in which multi-layer cloud decks frequently form. These exert a large influence on the local weather and climate, mainly due to their impact on radiation, the surface energy balance and thus the diurnal cycle of the atmospheric boundary layer. The main objective for the aircraft detachment was to build robust statistics of cloud properties in southern West Africa in different chemical landscapes to investigate the physical processes involved in their life cycle in such a complex chemical environment. As part of the DACCIWA field campaigns, three European aircraft (the German DLR Falcon 20, the French SAFIRE ATR 42 and the British BAS Twin Otter) conducted a total of 50 research flights across Ivory Coast, Ghana, Togo, and Benin from 27 June to 16 July 2016 for a total of 155 flight hours, including hours sponsored through 3 EUFAR projects. The aircraft were used in different ways based on their strengths, but all three had comparable instrumentation with the the capability to do gas-phase chemistry, aerosol and clouds, thereby generating a rich dataset of atmospheric conditions across the region. Eight types of flight objectives were conducted to achieve the goals of the DACCIWA: (i) Stratus clouds, (ii) Land-sea breeze clouds, (iii) Mid-level clouds, (iv) Biogenic emission, (v) City emissions, (vi) Flaring and ship emissions, (vii) Dust and biomass burning aerosols, and (viii) air-sea interactions. An overview of the DACCIWA aircraft campaign as well as first highlights from the airborne observations will be presented.

  9. Investigating the interactions of decentralized and centralized wastewater heat recovery systems.

    Science.gov (United States)

    Sitzenfrei, Robert; Hillebrand, Sebastian; Rauch, Wolfgang

    2017-03-01

    In the urban water cycle there are different sources for extracting energy. In addition to potential and chemical energy in the wastewater, thermal energy can also be recovered. Heat can be recovered from the wastewater with heat exchangers that are located decentralized and/or centralized at several locations throughout the system. It can be recovered directly at the source (e.g. in the showers and bathrooms), at building block level (e.g. warm water tanks collecting all grey water), in sewers or at the wastewater treatment plant. However, an uncoordinated installation of systems on such different levels can lead to competing technologies. To investigate these interactions, a modelling environment is set up, tested and calibrated based on continuous sewer temperature and flow measurements. With that approach different heat recovery scenarios on a household level (decentralized) and of in-sewer heat recovery (centralized) are investigated. A maximum performance drop of 40% for a centralized energy recovery system was estimated when all bathrooms are equipped with decentralized recovery systems. Therefore, the proposed modelling approach is suitable for testing different future conditions and to identify robust strategies for heat recovery systems from wastewater.

  10. Experimental investigation of wavy leading edges on rod-aerofoil interaction noise

    Science.gov (United States)

    Chen, Weijie; Qiao, Weiyang; Tong, Fan; Wang, Liangfeng; Wang, Xunnian

    2018-05-01

    Experimental studies are performed to investigate the effect of wavy leading edges on rod-aerofoil interaction noise in an open-jet anechoic wind tunnel. NACA 0012 aerofoils with straight and wavy leading edges (denoted by SLE and WLE, respectively) are embedded in the wake of a circular rod. The WLEs are in the form of sinusoidal profiles of amplitude, A, and wavelength, W. Parametric studies of the amplitude and wavelength characteristics are conducted to understand the effect of WLEs on noise reduction. It is observed that the sound power reduction level is sensitive to both the amplitude and wavelength of the WLEs. The WLE with the largest amplitude and smallest wavelength can achieve the most considerable noise reduction effect of up to 4 dB. The influences of rod diameter, d, and free-stream velocity, U0, on the noise reduction effect of the WLEs are also investigated. In addition, a parametric study of the influence of separating rod-aerofoil distance on the acoustic radiation of the SLE case and on the sound power reduction level of the WLE cases is performed. It is found that a critical spacing exists where the acoustic radiation and noise reduction can be divided into two different "modes".

  11. Investigation on the interaction between bovine serum albumin and 2,2-diphenyl-1-picrylhydrazyl

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiangrong [Department of Chemistry, School of Basic Medicine, Xinxiang Medical University, Xinxiang, Henan 453003 (China); Chen, Dejun; Wang, Gongke [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, 46 Jian-she Road, Mu Ye District, Xinxiang, Henan 453007 (China); Lu, Yan, E-mail: 1842457577@qq.com [School of Chemistry and Chemical Engineering, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Normal University, 46 Jian-she Road, Mu Ye District, Xinxiang, Henan 453007 (China)

    2014-12-15

    Albumin represents a very abundant and important circulating antioxidant in plasma. In this paper, the ability of bovine serum albumin (BSA) to scavenge 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical has been investigated using UV–vis absorption spectra. The result shows that the antioxidant activity of BSA against DPPH radical is similar to glutathione and the value of IC{sub 50} is 5.153×10{sup −5} mol L{sup −1}. The interaction between BSA and DPPH has been investigated without or with the eight popular antioxidants (L-ascorbic acid, α-tocopherol, glutathione, melatonin, (+)-catechin hydrate, procyanidine B3, β-carotene and astaxanthin) by means of fluorescence spectroscopy and circular dichroism (CD) spectroscopy. The fluorescence experiments show that DPPH quenches the fluorescence intensity of BSA through a static mechanism. The quenching process of DPPH with BSA is easily affected by the eight antioxidants, however, they cannot change the quenching mechanism of DPPH with BSA. Additionally, as shown by synchronous fluorescence spectroscopy and CD, DPPH may induce conformational and microenvironmental changes of BSA. - Highlights: • The antioxidant activity of BSA against DPPH is similar to glutathione. • DPPH can quench the fluorescence of BSA through a static quenching. • One molecule of DPPH radical reduced by one molecule of BSA. • The eight antioxidants cannot change the quenching mechanism of DPPH with BSA. • The binding parameters are decreased by the introduction of the eight antioxidants.

  12. AN INVESTIGATION TO RESOLVE THE INTERACTION BETWEEN FUEL CELL, POWER CONDITIONING SYSTEM AND APPLICATION LOADS

    Energy Technology Data Exchange (ETDEWEB)

    Sudip K. Mazumder; Chuck McKintyre; Dan Herbison; Doug Nelson; Comas Haynes; Michael von Spakovsky; Joseph Hartvigsen; S. Elangovan

    2003-11-03

    Solid-Oxide Fuel Cell (SOFC) stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry. However, this is not true for the thermal, mechanical, and chemical balance-of-plant subsystem (BOPS), where load-following time constants are, typically, several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes (such as, delayed load-following to compensate for slow BOPS response or expensive inductor filtering) to control stack responses to load variations. This limits the applicability of SOFC systems for load-varying stationary and transportation applications from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem, leading to optimal designs of power-conditioning electronics and optimal control strategies, which mitigate the electrical-feedback effects. Equally important are ''multiresolution'' finite-element modeling and simulation studies, which can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, for phase I of this project, sponsored by the U.S. DOE (NETL), we investigate the interactions among fuel cell, power-conditioning system, and application loads and their effects on SOFC reliability (durability) and performance. A number of methodologies have been used in Phase I to develop the steady-state and transient

  13. Boys' serotonin transporter genotype affects maternal behavior through self-control: a case of evocative gene-environment correlation.

    Science.gov (United States)

    Pener-Tessler, Roni; Avinun, Reut; Uzefovsky, Florina; Edelman, Shany; Ebstein, Richard P; Knafo, Ariel

    2013-02-01

    Self-control, involving processes such as delaying gratification, concentrating, planning, following instructions, and adapting emotions and behavior to situational requirements and social norms, may have a profound impact on children's adjustment. The importance of self-control suggests that parents are likely to modify their parenting based on children's ability for self-control. We study the effect of children's self-control, a trait partially molded by genetics, on their mothers' parenting, a process of evocative gene-environment correlation. Israeli 3.5-year-old twins (N = 320) participated in a lab session in which their mothers' parenting was observed. DNA was available from most children (N = 228). Mothers described children's self-control in a questionnaire. Boys were lower in self-control and received less positive parenting from their mothers, in comparison with girls. For boys, and not for girls, the serotonin transporter linked polymorphic region gene predicted mothers' levels of positive parenting, an effect mediated by boys' self-control. The implications of this evocative gene-environment correlation and the observed sex differences are discussed.

  14. Theoretical investigation of interaction between a rectangular plate and fractional viscoelastic foundation

    Directory of Open Access Journals (Sweden)

    Chengcheng Zhang

    2014-08-01

    Full Text Available The interaction between plates and foundations is a typical problem encountered in geotechnical engineering. The long-term plate performance is highly dependent on the rheological characteristics of ground soil. Compared with conventional linear rheology, the fractional calculus-based theory is a more powerful mathematical tool that can address this issue. This paper proposes a fractional Merchant model (FMM to investigate the time-dependent behavior of a simply supported rectangular plate on viscoelastic foundation. The correspondence principle involving Laplace transforms was employed to derive the closed-form solutions of plate response under uniformly distributed load. The plate deflection, bending moment, and foundation reaction calculated using the FMM were compared with the results obtained from the analogous elastic model (EM and the standard Merchant model (SMM. It is shown that the upper and lower bound solutions of the FMM can be determined using the EM. In addition, a parametric study was performed to examine the influences of the model parameters on the time-dependent behavior of the plate–foundation interaction problem. The results indicate that a small fractional differential order corresponds to a plate resting on a sandy soil foundation, while the fractional differential order value should be increased for a clayey soil foundation. The long-term performance of a foundation plate can be accurately simulated by varying the values of the fractional differential order and the viscosity coefficient. The observations from this study reveal that the proposed fractional model has the capability to capture the variation of plate deflection over many decades of time.

  15. Field Investigation of Stream-Aquifer Interactions: A Case Study in Coastal California

    Science.gov (United States)

    Pritchard-Peterson, D.; Malama, B.

    2017-12-01

    We report here results of a detailed investigation of the dynamic interaction between a stream and an alluvial aquifer at Swanton Pacific Ranch in the Scotts Creek watershed, Santa Cruz County, California. The aquifer is an important source of groundwater for cropland irrigation and for aquatic ecosystem support. Low summer base flows in Scotts Creek are a source of serious concern for land managers, fisheries biologists, and regulatory agencies due to the presence of federally protected steelhead trout and coho salmon. An understanding of the interaction between the stream and pumped aquifer will allow for assessment of the impacts of groundwater extraction on stream flows and is essential to establishing minimum flow requirements. This will aid in the development of sustainable riparian groundwater pumping practices that meet agricultural and ecological needs. Results of extensive direct-push sampling of the subsurface, laboratory falling-head permeameter tests and particle size analysis of aquifer sediments, multi-day pumping tests, long-term passive monitoring of aquifer hydraulic heads and stream stage and discharge, and electrical resistivity interrogation of the subsurface are reported here. Findings indicate that the permeable subsurface formation tapped by irrigation wells is a leaky semi-confined aquifer, overlain by a thin low permeability layer of silt and clay above which lies Scotts Creek. These results are particularly useful to land managers responsible for groundwater abstraction from wells that tap into the aquifer. Additionally, an index of stream-aquifer connectivity is proposed that would allow land managers to conveniently modify groundwater abstraction practices, minimizing concerns of stream depletion.

  16. Metabolic investigation of host/pathogen interaction using MS2-infected Escherichia coli

    Directory of Open Access Journals (Sweden)

    Jain Rishi

    2009-12-01

    Full Text Available Abstract Background RNA viruses are responsible for a variety of illnesses among people, including but not limited to the common cold, the flu, HIV, and ebola. Developing new drugs and new strategies for treating diseases caused by these viruses can be an expensive and time-consuming process. Mathematical modeling may be used to elucidate host-pathogen interactions and highlight potential targets for drug development, as well providing the basis for optimizing patient treatment strategies. The purpose of this work was to determine whether a genome-scale modeling approach could be used to understand how metabolism is impacted by the host-pathogen interaction during a viral infection. Escherichia coli/MS2 was used as the host-pathogen model system as MS2 is easy to work with, harmless to humans, but shares many features with eukaryotic viruses. In addition, the genome-scale metabolic model of E. coli is the most comprehensive model at this time. Results Employing a metabolic modeling strategy known as "flux balance analysis" coupled with experimental studies, we were able to predict how viral infection would alter bacterial metabolism. Based on our simulations, we predicted that cell growth and biosynthesis of the cell wall would be halted. Furthermore, we predicted a substantial increase in metabolic activity of the pentose phosphate pathway as a means to enhance viral biosynthesis, while a break down in the citric acid cycle was predicted. Also, no changes were predicted in the glycolytic pathway. Conclusions Through our approach, we have developed a technique of modeling virus-infected host metabolism and have investigated the metabolic effects of viral infection. These studies may provide insight into how to design better drugs. They also illustrate the potential of extending such metabolic analysis to higher order organisms, including humans.

  17. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    Directory of Open Access Journals (Sweden)

    Qiao Lyu

    2016-08-01

    Full Text Available The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS tests together with an acoustic emission (AE system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days in water dissoluted with gaseous/super-critical CO2. According to the experimental results, the values of UCS, Young’s modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO2. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young’s modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young’s modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO2, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO2. SC-CO2 causes a greater reduction of shale’s mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO2. The EDS results show that CO2-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation.

  18. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.

    1992-07-01

    In order to make it easy for the reader to see the specific research carried out and the progress made, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the George Washington University (GWU) theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions axe the issue, numerically accurate calculations axe always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art fewbody calculations that wig serve as a means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

  19. Microfluidic biofunctionalisation protocols to form multi-valent interactions for cell rolling and phenotype modification investigations

    KAUST Repository

    Perozziello, Gerardo

    2013-07-01

    In this study, we propose a fast, simple method to biofunctionalise microfluidic systems for cellomic investigations based on micro-fluidic protocols. Many available processes either require expensive and time-consuming protocols or are incompatible with the fabrication of microfluidic systems. Our method differs from the existing since it is applicable to an assembled system, uses few microlitres of reagents and it is based on the use of microbeads. The microbeads have specific surface moieties to link the biomolecules and couple cell receptors. Furthermore, the microbeads serve as arm spacer and offer the benefit of the multi-valent interaction. Microfluidics was adapted together with topology and biochemistry surface modifications to offer the microenvironment for cellomic studies. Based on this principle, we exploit the streptavidin-biotin interaction to couple antibodies to the biofunctionalised microfluidic environment within 5 h using 200 μL of reagents and biomolecules. We selected the antibodies able to form complexes with the MHC class I (MHC-I) molecules present on the cell membrane and involved in the immune surveillance. To test the microfluidic system, tumour cell lines (RMA) were rolled across the coupled antibodies to recognise and strip MHC-I molecules. As result, we show that cell rolling performed inside a microfluidic chamber functionalised with beads and the opportune antibody facilitate the removal of MHC class I molecules. We showed that the level of median fluorescent intensity of the MHC-I molecules is 300 for cells treated in a not biofunctionalised surface. It decreased to 275 for cells treated in a flat biofunctionalised surface and to 250 for cells treated on a surface where biofunctionalised microbeads were immobilised. The cells with reduced expression of MHC-I molecules showed, after cytotoxicity tests, susceptibility 3.5 times higher than normal cells. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.

    1991-07-01

    In order to make it easy for the reader to see the specific research carried out and the progress make, the following report of progress is done by topic. Each item has a format layout of Topic, Investigators, Objective, Significance, and Description of Progress, followed at the end by the relevant references. As is clear from the topics listed, the emphasis of the GWU theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered. When the excitation energy of the target nucleus is low, the aim has been carry out the continuum part of the theoretical work exactly, this is, by means of exact three- and four-body dynamics. When structure questions are the issue, exact calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. Implicit in our work is the question of how far one can go within the traditional nuclear physics framework, i.e., nucleons and mesons in a nonrelativistic setting. Our central goal is to carry through state-of-the-art few-body calculations that will serve as an unambiguous means of determining at what point standard nuclear physics requires quark degrees of freedom in order to understand the phenomena in question. So far, in the problems considered, there has been no evidence of the necessity to go beyond the traditional approach, though we always keep in mind that possibility. As our work is involved with questions in the intermediate-energy realm, moving from a nonrelativistic framework to a relativistic one is always a consideration. Currently, for the problems that have been pursued in this domain of energy, the issues concern far more the mechanisms of the reactions and structural questions than the need to move to relativistic dynamics

  1. Experimental Investigation of Mechanical Properties of Black Shales after CO2-Water-Rock Interaction

    Science.gov (United States)

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-01-01

    The effects of CO2-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO2 in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/super-critical CO2. According to the experimental results, the values of UCS, Young’s modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO2. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young’s modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young’s modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO2, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO2). SC-CO2 causes a greater reduction of shale’s mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO2. The EDS results show that CO2-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation. PMID:28773784

  2. Experimental Investigation of Mechanical Properties of Black Shales after CO₂-Water-Rock Interaction.

    Science.gov (United States)

    Lyu, Qiao; Ranjith, Pathegama Gamage; Long, Xinping; Ji, Bin

    2016-08-06

    The effects of CO₂-water-rock interactions on the mechanical properties of shale are essential for estimating the possibility of sequestrating CO₂ in shale reservoirs. In this study, uniaxial compressive strength (UCS) tests together with an acoustic emission (AE) system and SEM and EDS analysis were performed to investigate the mechanical properties and microstructural changes of black shales with different saturation times (10 days, 20 days and 30 days) in water dissoluted with gaseous/super-critical CO₂. According to the experimental results, the values of UCS, Young's modulus and brittleness index decrease gradually with increasing saturation time in water with gaseous/super-critical CO₂. Compared to samples without saturation, 30-day saturation causes reductions of 56.43% in UCS and 54.21% in Young's modulus for gaseous saturated samples, and 66.05% in UCS and 56.32% in Young's modulus for super-critical saturated samples, respectively. The brittleness index also decreases drastically from 84.3% for samples without saturation to 50.9% for samples saturated in water with gaseous CO₂, to 47.9% for samples saturated in water with super-critical carbon dioxide (SC-CO₂). SC-CO₂ causes a greater reduction of shale's mechanical properties. The crack propagation results obtained from the AE system show that longer saturation time produces higher peak cumulative AE energy. SEM images show that many pores occur when shale samples are saturated in water with gaseous/super-critical CO₂. The EDS results show that CO₂-water-rock interactions increase the percentages of C and Fe and decrease the percentages of Al and K on the surface of saturated samples when compared to samples without saturation.

  3. Significance of investigating allelopathic interactions of marine organisms in the discovery and development of cytotoxic compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Singh, A.; Thakur, N.L.

    like (1) growth interactions (e.g. overgrowth by corals) [27], (2) aggressive behaviour (e.g., induced development of sweeper tentacles by bryozoans [28], (3) feeding interactions (e.g., extracoelenteric digestion via mesenteries filaments...

  4. Interactions between {beta}-carboline alkaloids and bovine serum albumin: Investigation by spectroscopic approach

    Energy Technology Data Exchange (ETDEWEB)

    Nafisi, Shohreh, E-mail: drshnafisi@gmail.com [Department of Chemistry, Islamic Azad University, Central Tehran Branch (IAUCTB), Tehran (Iran, Islamic Republic of); Panahyab, Ataollah [Department of Chemistry, Islamic Azad University, Central Tehran Branch (IAUCTB), Tehran (Iran, Islamic Republic of); Bagheri Sadeghi, Golshan [Department of Biology, Islamic Azad University, Science and Research Branch, Tehran (Iran, Islamic Republic of)

    2012-09-15

    {beta}-Carboline alkaloids are present in medicinal plants such as Peganum harmala L. that have been used as folk medicine in anticancer therapy. BSA is the major soluble protein constituent of the circulatory system, and has many physiological functions including the transport of a variety of compounds. This study is the first attempt to investigate the binding of {beta}-carboline alkaloids to BSA by using a constant protein concentration and varying drug concentrations at pH 7.2. FTIR and UV-Vis spectroscopic methods were used to analyze the binding modes of {beta}-carboline alkaloids, the binding constants and the effects of drug complexation on BSA stability and conformation. Spectroscopic evidence showed that {beta}-carboline alkaloids bind BSA via hydrophobic interaction and van der Waals contacts along with H-bonding with the -NH groups, with overall binding constants of K{sub harmine-BSA}=2.04 Multiplication-Sign 10{sup 4} M{sup -1}, K{sub tryptoline-BSA}=1.2 Multiplication-Sign 10{sup 4} M{sup -1}, K{sub harmaline-BSA}=5.04 Multiplication-Sign 10{sup 3} M{sup -1}, K{sub harmane-BSA}=1.41 Multiplication-Sign 10{sup 3} M{sup -1} and K{sub harmalol-BSA}=1.01 Multiplication-Sign 10{sup 3} M{sup -1}, assuming that there is one drug molecule per protein. The BSA secondary structure was altered with a major decrease of {alpha}-helix from 64% (free protein) to 59% (BSA-harmane), 56% (BSA-harmaline and BSA-harmine), 55% (BSA-tryptoline), 54% (BSA-harmalol) and {beta}-sheet from 15% (free protein) to 6-8% upon {beta}-carboline alkaloids complexation, inducing a partial protein destabilization. - Highlights: Black-Right-Pointing-Pointer We model the binding of {beta}-carboline alkaloids to BSA by using the spectroscopic methods. Black-Right-Pointing-Pointer We investigate the effects of drug complexation on BSA stability and conformation. Black-Right-Pointing-Pointer A partial protein destabilization occurred at high alkaloids concentration. Black

  5. Investigation of a Potential Pharmacokinetic Interaction Between Nebivolol and Fluvoxamine in Healthy Volunteers.

    Science.gov (United States)

    Gheldiu, Ana-Maria; Vlase, Laurian; Popa, Adina; Briciu, Corina; Muntean, Dana; Bocsan, Corina; Buzoianu, Anca; Achim, Marcela; Tomuta, Ioan; Todor, Ioana; Neag, Maria

    2017-01-01

    To investigate whether fluvoxamine coadministration can influence the pharmacokinetic properties of nebivolol and its active hydroxylated metabolite (4-OH-nebivolol) and to assess the consequences of this potential pharmacokinetic interaction upon nebivolol pharmacodynamics. This open-label, non-randomized, sequential clinical trial consisted of two periods: Period 1 (Reference), during which each volunteer received a single dose of 5 mg nebivolol and Period 2 (Test), when a combination of 5 mg nebivolol and 100 mg fluvoxamine was given to all subjects, after a 6-days pretreatment regimen with fluvoxamine (50-100 mg/day). Non-compartmental analysis was used to determine the pharmacokinetic parameters of nebivolol and its active metabolite. The pharmacodynamic parameters (blood pressure and heart rate) were assessed at rest after each nebivolol intake, during both study periods. Fluvoxamine pretreatment increased Cmax and AUC0-∞  of nebivolol (Cmax: 1.67 ± 0.690  vs 2.20 ± 0.970  ng/mL; AUC0-∞: 12.1 ± 11.0  vs 19.3 ± 19.5  ng*h/mL ) and of its active metabolite (Cmax: 0.680  ± 0.220  vs 0.960 ± 0.290  ng/mL; AUC0-∞: 17.6 ±20.1  vs 25.5 ± 29.9  ng*h/mL). Apart from Cmax,AUC0-t and AUC0-∞, the other pharmacokinetic parameters (tmax, kel and t½) were not significantly different between study periods. As for the pharmacodynamic analysis, decreases in blood pressure and heart rate after nebivolol administration were similar with and without fluvoxamine concomitant intake. Due to enzymatic inhibition, fluvoxamine increases the exposure to nebivolol and its active hydroxylated metabolite in healthy volunteers. This did not influence the blood pressure and heart-rate lowering effects of the beta-blocker administered as single-dose. However, more detail studies involving actual patients are required to further investigate the clinical relevance of this drug interaction. This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For

  6. Interactions between β-carboline alkaloids and bovine serum albumin: Investigation by spectroscopic approach

    International Nuclear Information System (INIS)

    Nafisi, Shohreh; Panahyab, Ataollah; Bagheri Sadeghi, Golshan

    2012-01-01

    β-Carboline alkaloids are present in medicinal plants such as Peganum harmala L. that have been used as folk medicine in anticancer therapy. BSA is the major soluble protein constituent of the circulatory system, and has many physiological functions including the transport of a variety of compounds. This study is the first attempt to investigate the binding of β-carboline alkaloids to BSA by using a constant protein concentration and varying drug concentrations at pH 7.2. FTIR and UV–Vis spectroscopic methods were used to analyze the binding modes of β-carboline alkaloids, the binding constants and the effects of drug complexation on BSA stability and conformation. Spectroscopic evidence showed that β-carboline alkaloids bind BSA via hydrophobic interaction and van der Waals contacts along with H-bonding with the –NH groups, with overall binding constants of K harmine–BSA =2.04×10 4 M −1 , K tryptoline–BSA =1.2×10 4 M −1 , K harmaline–BSA =5.04×10 3 M −1 , K harmane–BSA =1.41×10 3 M −1 and K harmalol–BSA =1.01×10 3 M −1 , assuming that there is one drug molecule per protein. The BSA secondary structure was altered with a major decrease of α-helix from 64% (free protein) to 59% (BSA–harmane), 56% (BSA–harmaline and BSA–harmine), 55% (BSA–tryptoline), 54% (BSA–harmalol) and β-sheet from 15% (free protein) to 6–8% upon β-carboline alkaloids complexation, inducing a partial protein destabilization. - Highlights: ► We model the binding of β-carboline alkaloids to BSA by using the spectroscopic methods. ► We investigate the effects of drug complexation on BSA stability and conformation. ► A partial protein destabilization occurred at high alkaloids concentration. ► Alkaloids bind BSA via hydrophobic interactions and H-bonding with the ---NH groups. ► BSA can be considered as a good carrier for transportation of β-carboline alkaloids.

  7. Low-temperature nuclear magnetic resonance investigation of systems frustrated by competing exchange interactions

    Science.gov (United States)

    Roy, Beas

    This doctoral thesis emphasizes on the study of frustrated systems which form a very interesting class of compounds in physics. The technique used for the investigation of the magnetic properties of the frustrated materials is Nuclear Magnetic Resonance (NMR). NMR is a very novel tool for the microscopic study of the spin systems. NMR enables us to investigate the local magnetic properties of any system exclusively. The NMR experiments on the different systems yield us knowledge of the static as well as the dynamic behavior of the electronic spins. Frustrated systems bear great possibilities of revelation of new physics through the new ground states they exhibit. The vandates AA'VO(PO4)2 [AA' ≡ Zn2 and BaCd] are great prototypes of the J1-J2 model which consists of magnetic ions sitting on the corners of a square lattice. Frustration is caused by the competing nearest-neighbor (NN) and next-nearest neighbor (NNN) exchange interactions. The NMR investigation concludes a columnar antiferromagnetic (AFM) state for both the compounds from the sharp peak of the nuclear spin-lattice relaxation rate (1/T1) and a sudden broadening of the 31P-NMR spectrum. The important conclusion from our study is the establishment of the first H-P-T phase diagram of BaCdVO(PO4)2. Application of high pressure reduces the saturation field (HS) in BaCdVO(PO4)2 and decreases the ratio J2/J1, pushing the system more towards a questionable boundary (a disordered ground state) between the columnar AFM and a ferromagnetic ground state. A pressure up to 2.4 GPa will completely suppress HS. The Fe ions in the `122' iron-arsenide superconductors also sit on a square lattice thus closely resembling the J1-J2 model. The 75As-NMR and Nuclear Quadrupole Resonance (NQR) experiments are conducted in the compound CaFe2As2 prepared by two different heat treatment methods (`as-grown' and `annealed'). Interestingly the two samples show two different ground states. While the ground state of the `as

  8. Investigating the effects of nitrous oxide sedation on frontal-parietal interactions.

    Science.gov (United States)

    Ryu, Ji-Ho; Kim, Pil-Jong; Kim, Hong-Gee; Koo, Yong-Seo; Shin, Teo Jeon

    2017-06-09

    Although functional connectivity has received considerable attention in the study of consciousness, few studies have investigated functional connectivity limited to the sedated state where consciousness is maintained but impaired. The aim of the present study was to investigate changes in functional connectivity of the parietal-frontal network resulting from nitrous oxide-induced sedation, and to determine the neural correlates of cognitive impairment during consciousness transition states. Electroencephalography was acquired from healthy adult patients who underwent nitrous oxide inhalation to induce cognitive impairment, and was analyzed using Granger causality (GC). Periods of awake, sedation and recovery for GC between frontal and parietal areas in the delta, theta, alpha, beta, gamma and total frequency bands were obtained. The Friedman test with post-hoc analysis was conducted for GC values of each period for comparison. As a sedated state was induced by nitrous oxide inhalation, power in the low frequency band showed increased activity in frontal regions that was reversed with discontinuation of nitrous oxide. Feedback and feedforward connections analyzed in spectral GC were changed differently in accordance with EEG frequency bands in the sedated state by nitrous oxide administration. Calculated spectral GC of the theta, alpha, and beta frequency regions in the parietal-to-frontal direction was significantly decreased in the sedated state while spectral GC in the reverse direction did not show significant change. Frontal-parietal functional connectivity is significantly affected by nitrous oxide inhalation. Significantly decreased parietal-to-frontal interaction may induce a sedated state. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. An Investigation to Resolve the Interaction Between Fuel Cell, Power Conditioning System and Application Loads

    Energy Technology Data Exchange (ETDEWEB)

    Sudip K. Mazumder

    2005-12-31

    Development of high-performance and durable solidoxide fuel cells (SOFCs) and a SOFC power-generating system requires knowledge of the feedback effects from the power-conditioning electronics and from application-electrical-power circuits that may pass through or excite the power-electronics subsystem (PES). Therefore, it is important to develop analytical models and methodologies, which can be used to investigate and mitigate the effects of the electrical feedbacks from the PES and the application loads (ALs) on the reliability and performance of SOFC systems for stationary and non-stationary applications. However, any such attempt to resolve the electrical impacts of the PES on the SOFC would be incomplete unless one utilizes a comprehensive analysis, which takes into account the interactions of SOFC, PES, balance-of-plant system (BOPS), and ALs as a whole. SOFCs respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry, which is not true for the thermal and mechanical time constants of the BOPS, where load-following time constants are, typically, several orders of magnitude higher. This dichotomy can affect the lifetime and durability of the SOFCSs and limit the applicability of SOFC systems for load-varying stationary and transportation applications. Furthermore, without validated analytical models and investigative design and optimization methodologies, realizations of cost-effective, reliable, and optimal PESs (and power-management controls), in particular, and SOFC systems, in general, are difficult. On the whole, the research effort can lead to (a) cost-constrained optimal PES design for high-performance SOFCS and high energy efficiency and power density, (b) effective SOFC power-system design, analyses, and optimization, and (c) controllers and modulation schemes for mitigation of electrical impacts and wider-stability margin and enhanced system efficiency.

  10. Applying Geospatial Techniques to Investigate Boundary Layer Land-Atmosphere Interactions Involved in Tornadogensis

    Science.gov (United States)

    Weigel, A. M.; Griffin, R.; Knupp, K. R.; Molthan, A.; Coleman, T.

    2017-12-01

    Northern Alabama is among the most tornado-prone regions in the United States. This region has a higher degree of spatial variability in both terrain and land cover than the more frequently studied North American Great Plains region due to its proximity to the southern Appalachian Mountains and Cumberland Plateau. More research is needed to understand North Alabama's high tornado frequency and how land surface heterogeneity influences tornadogenesis in the boundary layer. Several modeling and simulation studies stretching back to the 1970's have found that variations in the land surface induce tornadic-like flow near the surface, illustrating a need for further investigation. This presentation introduces research investigating the hypothesis that horizontal gradients in land surface roughness, normal to the direction of flow in the boundary layer, induce vertically oriented vorticity at the surface that can potentially aid in tornadogenesis. A novel approach was implemented to test this hypothesis using a GIS-based quadrant pattern analysis method. This method was developed to quantify spatial relationships and patterns between horizontal variations in land surface roughness and locations of tornadogenesis. Land surface roughness was modeled using the Noah land surface model parameterization scheme which, was applied to MODIS 500 m and Landsat 30 m data in order to compare the relationship between tornadogenesis locations and roughness gradients at different spatial scales. This analysis found a statistical relationship between areas of higher roughness located normal to flow surrounding tornadogenesis locations that supports the tested hypothesis. In this presentation, the innovative use of satellite remote sensing data and GIS technologies to address interactions between the land and atmosphere will be highlighted.

  11. Investigation of antioxidant interactions between Radix Astragali and Cimicifuga foetida and identification of synergistic antioxidant compounds.

    Directory of Open Access Journals (Sweden)

    Fei Wang

    Full Text Available The medicinal plants of Huang-qi (Radix Astragali and Sheng-ma (Cimicifuga foetida demonstrate significantly better antioxidant effects when used in combination than when used alone. However, the bioactive components and interactional mechanism underlying this synergistic action are still not well understood. In the present study, 2,2-diphenyl-1-picrylhydrazyl (DPPH radical scavenging assay was employed to investigate the antioxidant capacity of single herbs and their combination with the purpose of screening synergistic antioxidant compounds from them. Chromatographic isolation was performed on silica gel, Sephadex LH-20 columns and HPLC, and consequently to yield formononetin, calycosin, ferulic acid and isoferulic acid, which were identified by their retention time, UV λmax, MS and MS/MS data. The combination of isoferulic acid and calycosin at a dose ratio of 1∶1 resulted in significant synergy in scavenging DPPH radicals and ferric reducing antioxidant power (FRAP assay. Furthermore, the protective effects of these four potential synergistic compounds were examined using H2O2-induced HepG2 Cells bioassay. Results revealed that the similar synergy was observed in the combination of isoferulic acid and calycosin. These findings might provide some theoretical basis for the purported synergistic efficiency of Huang-qi and Sheng-ma as functional foods, dietary supplements and medicinal drugs.

  12. Investigation of molten corium-concrete interaction phenomena and aerosol release

    International Nuclear Information System (INIS)

    Spencer, B.W.; Thompson, D.H.; Armstrong, D.R.; Fink, J.K.; Gunther, W.H.; Kilsdonk, D.J.; Sehgal, B.R.

    1987-01-01

    The Electric Power Research Institute is sponsoring a program of laboratory investigations at Argonne National Laboratory to study the interaction between molten core materials and reactor concrete basemats during postulated severe reactor accidents, with particular emphasis on measurements of the magnitude and chemical species present in the aerosol releases. The approach in this program is to sustain internal heat generation in reactor-material corium using direct electrical heating and to develop test operating and diagnostics capabilities with a series of small- and intermediate-scale scoping tests followed by fully instrumented large-scale testing. Real reactor materials (UO 2 , ZrO 2 , oxides of stainless steel, plus metallics) are used, with small amounts of La 2 O 3 , BaO, and SrO added to simulate nonvolatile fission products. In intermediate-scale scoping tests completed to date, corium inventories of up to 29 kg have been heated with power inputs in excess of 1 kW/kg melt. The measured concrete ablation rates have ranged from 0.9 to 3.9 mm/minute. Aerosol samples have been examined using a scanning electron microscope and show submicron particles, 2-6 micrometer spheres, and agglomerates that range from a few micrometers to string 13 micrometers in length

  13. Investigating Power System Primary and Secondary Reserve Interaction under High Wind Power Penetration

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yingchen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tan, Jin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Krad, Ibrahim [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yang, Rui [National Renewable Energy Lab. (NREL), Golden, CO (United States); Gevorgian, Vahan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ela, Erik [Electric Power Research Inst. (EPRI), Knoxville, TN (United States)

    2016-12-01

    Power system frequency needs to be maintained close to its nominal value at all times to successfully balance load and generation and maintain system reliability. Adequate primary frequency response and secondary frequency response are the primary forces to correct an energy imbalance at the second-to-minute level. As wind energy becomes a larger portion of the world's energy portfolio, there is an increased need for wind to provide frequency response. This paper addresses one of the major concerns about using wind for frequency regulation: the unknown factor of the interaction between primary and secondary reserves. The lack of a commercially available tool to model this has limited the energy industry's understanding of when the depletion of primary reserves will impact the performance of secondary response or vice versa. This paper investigates the issue by developing a multi-area frequency response integration tool with combined primary and secondary capabilities. The simulation is conducted in close coordination with economical energy scheduling scenarios to ensure credible simulation results.

  14. Man-made materials : An exciting area for hyperfine-interaction investigation

    International Nuclear Information System (INIS)

    Freeman, A.; Wu, R.

    1996-01-01

    Man-made low-dimensional magnetic systems including surfaces, interfaces and multilayers, have attracted a great amount of attention in the past decade because, as expected, the lowered symmetry and coordination number offer a variety of opportunities for inducing new and exotic phenomena and so hold out the promise of new device applications. Local spin density functional (LSDF) ab initio electronic-structure calculations employing the full-potential -linearized augmented-plane-wave (FLAPW) method have played a key role in the development of this exciting field by not only providing a clearer understanding of the experimental observations but also predicting new systems with desired properties. One of the striking successes of theory in the last decade has been the calculation of hyperfine fields at surfaces and interfaces. Concurrently, several groups have followed the pioneering work of Korecki and Gradmann and have measured hyperfine fields at surfaces and interfaces. In this paper, it is reviewed new features of hyperfine-interaction investigations in man-made materials which are essential because the hyperfine field is not proportional to the magnetization and so interpretations of experiment are totally dependent on theory

  15. Stapled peptides as a new technology to investigate protein-protein interactions in human platelets.

    Science.gov (United States)

    Iegre, Jessica; Ahmed, Niaz S; Gaynord, Josephine S; Wu, Yuteng; Herlihy, Kara M; Tan, Yaw Sing; Lopes-Pires, Maria E; Jha, Rupam; Lau, Yu Heng; Sore, Hannah F; Verma, Chandra; O' Donovan, Daniel H; Pugh, Nicholas; Spring, David R

    2018-05-28

    Platelets are blood cells with numerous crucial pathophysiological roles in hemostasis, cardiovascular thrombotic events and cancer metastasis. Platelet activation requires the engagement of intracellular signalling pathways that involve protein-protein interactions (PPIs). A better understanding of these pathways is therefore crucial for the development of selective anti-platelet drugs. New strategies for studying PPIs in human platelets are required to overcome limitations associated with conventional platelet research methods. For example, small molecule inhibitors can lack selectivity and are often difficult to design and synthesise. Additionally, development of transgenic animal models is costly and time-consuming and conventional recombinant techniques are ineffective due to the lack of a nucleus in platelets. Herein, we describe the generation of a library of novel, functionalised stapled peptides and their first application in the investigation of platelet PPIs. Moreover, the use of platelet-permeable stapled Bim BH3 peptides confirms the part of Bim in phosphatidyl-serine (PS) exposure and reveals a role for the Bim protein in platelet activatory processes. Our work demonstrates that functionalised stapled peptides are a complementary alternative to conventional platelet research methods, and could make a significant contribution to the understanding of platelet signalling pathways and hence to the development of anti-platelet drugs.

  16. Biomimetic Proteoglycan Interactions with Type I Collagen Investigated via 2D and 3D TEM

    Science.gov (United States)

    Moorehead, Carli

    Collagen is one of the leading components in extracellular matrix (ECM), providing durability, structural integrity, and functionality for many tissues. Regulation of collagen fibrillogenesis and degradation is important in the treatment of a number of diseases from orthopedic injuries to genetic deficiencies. Recently, novel, biocompatible, semi-synthetic biomimetic proteoglycans (BPGs) were developed, which consist of an enzymatically resistant synthetic polymer core and natural chondroitin sulfate bristles. It was demonstrated that BPGs affect type I collagen fibrillogenesis in vitro, as reflected by their impact delaying the kinetic formation of gels similar to native PGs. This indicates that the morphology of collagen scaffolds as well as endogenous ECM could also be modulated by these proteoglycan mimics. However, the imaging modality used previously, reflectance confocal microscopy, did not yield the resolution necessary to spatially localize BPGs within the collagen network or investigate the effect of BPGs on the quality of collagen fibrils produced in an in vitro fibrillogenesis model which is important for understanding the method of interaction. Consequently, a histological technique, electron tomography, was adapted and utilized to 3D image the nano-scale structures within this simplified tissue model. BPGs were found to aid in lateral growth and enhance fibril banding periodicity resulting in structures more closely resembling those in tissue, in addition to attaching to the collagen surface despite the lack of a protein core.

  17. A theoretical and experimental investigation of the interaction between gas molecules and cryogenic surfaces

    International Nuclear Information System (INIS)

    Varlam, M.; Steflea, D.; Chiriloaie, N.

    1992-01-01

    The cryo-pumping performance of a cryo-surface subjected to the impingement of low-pressure, thermal-velocity air flow is experimentally and theoretically investigated. Our purpose is to determine the angular dependence of capture coefficients for gas molecules incident on a cryogenic surface under conditions closely approximating those prevailing in cryo-pumped high vacuum chambers. The classical model for the interaction of gas atoms and the solid surface - the 'soft-tube' model - is developed and the basic assumption are examined. Starting from this theory we have calculated the capture coefficient of the Ag - N system and these values are discussed in terms of principal parameters considered. Despite the many simplifying assumptions, this model has the important attribute that it yields closed-form expressions for the capture coefficient of gas molecules. The molecular beam technique offers a direct experimental method for determining the capture coefficient for molecules with given angles of incidence by measuring the incident and reflected molecular fluxes. An experimental setup is also designed and the method for determining these coefficients is proposed. (Author)

  18. Density functional theory investigation of oxygen interaction with boron-doped graphite

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Juan; Wang, Chen [State Key Lab of New Ceramic and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Liang, Tongxiang, E-mail: txliang@tsinghua.edu.cn [State Key Lab of New Ceramic and Fine Processing, Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084 (China); Lai, Wensheng [Advanced Material Laboratory, School of Materials Science & Engineering, Tsinghua University, Beijing, 100084 (China)

    2016-12-30

    Highlights: • Density-functional approach is applied to study the interaction of oxygen with boron-doped graphite. • Adsorption and diffusion of oxygen atoms on boron doped graphite surfaces are studied. • Recombination of oxygen is investigated by ER and LH mechanisms. • Low boron concentration facilitates O{sub 2} formation while high boron loading inhibits the recombination. • The presence of B−B bonds due to boron accumulation makes it impossible for oxygen recombination. - Abstract: Boron inserted as impurity by substitution of carbon atoms in graphite is known to change (improve or deteriorate) oxidation resistance of nuclear graphite, but the reason for both catalytic and inhibiting oxidation is still uncertain. As a first step, this work is more specially devoted to the adsorption and diffusion of oxygen atoms on the surface and related to the problem of oxygen retention on the pure and boron-containing graphite surfaces. Adsorption energies and energy barriers associated to the diffusion for molecular oxygen recombination are calculated in the density functional theory framework. The existence of boron modifies the electronic structure of the surface, which results in an increase of the adsorption energy for O. However, low boron loading makes it easier for the recombination into molecular oxygen. For high boron concentration, it induces a better O retention capability in graphite because the presence of B-B bonds decreases recombination of the adsorbed oxygen atoms. A possible explanation for both catalytic and inhibiting effects of boron in graphite is proposed.

  19. Investigation of ferromagnetic spinel semiconductors by hyperfine interactions of implanted nuclear probes

    CERN Document Server

    Samokhvalov, V; Dietrich, M; Schneider, F; Tiginyanu, I M; Tsurkan, V; Unterricker, S

    2003-01-01

    The semiconducting ferromagnetic spinel compounds CdCr//2Se //4, CdCr //2S//4, HgCr//2Se//4 and CuCr//2Se//4 (metallic) were investigated by the perturbed angular correlations (PAC) method with the radioactive probes **1**1**1In, **1**1**1**mCd, **1**1**1Ag, **1**1**7Cd, **1**9**9**mHg and **7**7Br. The probes were implanted at the ISOLDE on-line separator (CERN-Geneva) into single crystals. From the time dependence of the PAC spectra and the measured hyperfine interaction parameters: electric field gradient and magnetic hyperfine field, the probe positions and the thermal behavior of the probes could be determined. Cd, Ag and Hg are substituted at the A-site, In at the A- and B-site in the semiconducting compounds and Br at the anion position. Electric and magnetic hyperfine fields were used as test quantities for theoretical charge and spin density distributions of LAPW calculations (WIEN97).

  20. Use of a Rabbit Soft Tissue Chamber Model to Investigate Campylobacter jejuni - Host Interactions

    Directory of Open Access Journals (Sweden)

    Annika eFlint

    2010-11-01

    Full Text Available Despite the prevalence of C. jejuni as an important food borne pathogen, the microbial factors governing its infection process are poorly characterized. In this study, we developed a novel rabbit soft tissue chamber model to investigate C. jejuni interactions with its host. The in vivo transcriptome profile of C. jejuni was monitored as a function of time post-infection by competitive microarray hybridization with cDNA obtained from C. jejuni grown in vitro. Genome-wide expression analysis identified 449 genes expressed at significantly different levels in vivo. Genes implicated to play important roles in early colonization of C. jejuni within the tissue chamber include up-regulation of genes involved in ribosomal protein synthesis and modification, heat shock response, and primary adaptation to the host environment (DccSR regulon. Genes encoding proteins involved in the TCA cycle and flagella related components were found to be significantly down regulated during early colonization. Oxidative stress defense and stringent response genes were found to be maximally induced during the acute infectious phase. Overall, these findings reveal possible mechanisms involved in adaptation of Campylobacter to the host.

  1. Numerical Investigation of the Interaction of Counterflowing Jets and Supersonic Capsule Flows

    Science.gov (United States)

    Venkatachari, Balaji Shankar; Ito, Yasushi; Cheng, Gary; Chang, Chau-Lyan

    2011-01-01

    Use of counterflowing jets ejected into supersonic freestreams as a flow control concept to modify the external flowfield has gained renewed interest with regards to potential retropropulsion applications pertinent to entry, descent, and landing investigations. This study describes numerical computations of such a concept for a scaled wind-tunnel capsule model by employing the space-time conservation element solution element viscous flow solver with unstructured meshes. Both steady-state and time-accurate computations are performed for several configurations with different counterflowing jet Mach numbers. Axisymmetric computations exploring the effect of the jet flow rate and jet Mach number on the flow stability, jet interaction with the bow shock and its subsequent impact on the aerodynamic and aerothermal loads on the capsule body are carried out. Similar to previous experimental findings, both long and short penetration modes exist at a windtunnel Mach number of 3.48. It was found that both modes exhibit non-stationary behavior and the former is much more unstable than the latter. It was also found that the unstable long penetration mode only exists in a relatively small range of the jet mass flow rate. Solution-based mesh refinement procedures are used to improve solution accuracy and provide guidelines for a more effective mesh generation procedure for parametric studies. Details of the computed flowfields also serve as a means to broaden the knowledge base for future retropropulsion design studies.

  2. A detailed aerosol mixing state model for investigating interactions between mixing state, semivolatile partitioning, and coagulation

    Directory of Open Access Journals (Sweden)

    J. Lu

    2010-04-01

    Full Text Available A new method for describing externally mixed particles, the Detailed Aerosol Mixing State (DAMS representation, is presented in this study. This novel method classifies aerosols by both composition and size, using a user-specified mixing criterion to define boundaries between compositional populations. Interactions between aerosol mixing state, semivolatile partitioning, and coagulation are investigated with a Lagrangian box model that incorporates the DAMS approach. Model results predict that mixing state affects the amount and types of semivolatile organics that partition to available aerosol phases, causing external mixtures to produce a more size-varying composition than internal mixtures. Both coagulation and condensation contribute to the mixing of emitted particles, producing a collection of multiple compositionally distinct aerosol populations that exists somewhere between the extremes of a strictly external or internal mixture. The selection of mixing criteria has a significant impact on the size and type of individual populations that compose the modeled aerosol mixture. Computational demands for external mixture modeling are significant and can be controlled by limiting the number of aerosol populations used in the model.

  3. Numerical investigation of interactions between marine atmospheric boundary layer and offshore wind farm

    Science.gov (United States)

    Lyu, Pin; Chen, Wenli; Li, Hui; Shen, Lian

    2017-11-01

    In recent studies, Yang, Meneveau & Shen (Physics of Fluids, 2014; Renewable Energy, 2014) developed a hybrid numerical framework for simulation of offshore wind farm. The framework consists of simulation of nonlinear surface waves using a high-order spectral method, large-eddy simulation of wind turbulence on a wave-surface-fitted curvilinear grid, and an actuator disk model for wind turbines. In the present study, several more precise wind turbine models, including the actuator line model, actuator disk model with rotation, and nacelle model, are introduced into the computation. Besides offshore wind turbines on fixed piles, the new computational framework has the capability to investigate the interaction among wind, waves, and floating wind turbines. In this study, onshore, offshore fixed pile, and offshore floating wind farms are compared in terms of flow field statistics and wind turbine power extraction rate. The authors gratefully acknowledge financial support from China Scholarship Council (No. 201606120186) and the Institute on the Environment of University of Minnesota.

  4. Thermodynamics of the interaction of the food additive tartrazine with serum albumins: a microcalorimetric investigation.

    Science.gov (United States)

    Basu, Anirban; Kumar, Gopinatha Suresh

    2015-05-15

    The thermodynamics of the interaction of the food colourant tartrazine with two homologous serum proteins, HSA and BSA, were investigated, employing microcalorimetric techniques. At T=298.15K the equilibrium constants for the tartrazine-BSA and HSA complexation process were evaluated to be (1.92 ± 0.05) × 10(5)M(-1) and (1.04 ± 0.05) × 10(5)M(-1), respectively. The binding was driven by a large negative standard molar enthalpic contribution. The binding was dominated essentially by non-polyelectrolytic forces which remained largely invariant at all salt concentrations. The polyelectrolytic contribution was weak at all salt concentrations and accounted for only 6-18% of the total standard molar Gibbs energy change in the salt concentration range 10-50mM. The negative standard molar heat capacity values, in conjunction with the enthalpy-entropy compensation phenomenon observed, established the involvement of dominant hydrophobic forces in the complexation process. Tartrazine enhanced the stability of both serum albumins against thermal denaturation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Genes, environment and sport performance: why the nature-nurture dualism is no longer relevant.

    Science.gov (United States)

    Davids, Keith; Baker, Joseph

    2007-01-01

    The historical debate on the relative influences of genes (i.e. nature) and environment (i.e. nurture) on human behaviour has been characterised by extreme positions leading to reductionist and polemic conclusions. Our analysis of research on sport and exercise behaviours shows that currently there is little support for either biologically or environmentally deterministic perspectives on elite athletic performance. In sports medicine, recent molecular biological advances in genomic studies have been over-interpreted, leading to a questionable 'single-gene-as-magic-bullet' philosophy adopted by some practitioners. Similarly, although extensive involvement in training and practice is needed at elite levels, it has become apparent that the acquisition of expertise is not merely about amassing a requisite number of practice hours. Although an interactionist perspective has been mooted over the years, a powerful explanatory framework has been lacking. In this article, we propose how the complementary nature of degenerate neurobiological systems might provide the theoretical basis for explaining the interactive influence of genetic and environmental constraints on elite athletic performance. We argue that, due to inherent human degeneracy, there are many different trajectories to achieving elite athletic performance. While the greatest training responses may be theoretically associated with the most favourable genotypes being exposed to highly specialised training environments, this is a rare and complex outcome. The concept of degeneracy provides us with a basis for understanding why each of the major interacting constraints might act in a compensatory manner on the acquisition of elite athletic performance.

  6. Numerical investigation of particle-blast interaction during explosive dispersal of liquids and granular materials

    Science.gov (United States)

    Pontalier, Q.; Lhoumeau, M.; Milne, A. M.; Longbottom, A. W.; Frost, D. L.

    2018-04-01

    Experiments show that when a high-explosive charge with embedded particles or a charge surrounded by a layer of liquid or granular material is detonated, the flow generated is perturbed by the motion of the particles and the blast wave profile differs from that of an ideal Friedlander form. Initially, the blast wave overpressure is reduced due to the energy dissipation resulting from compaction, fragmentation, and heating of the particle bed, and acceleration of the material. However, as the blast wave propagates, particle-flow interactions collectively serve to reduce the rate of decay of the peak blast wave overpressure. Computations carried out with a multiphase hydrocode reproduce the general trends observed experimentally and highlight the transition between the particle acceleration/deceleration phases, which is not accessible experimentally, since the particles are obscured by the detonation products. The dependence of the particle-blast interaction and the blast mitigation effectiveness on the mitigant to explosive mass ratio, the particle size, and the initial solid volume fraction is investigated systematically. The reduction in peak blast overpressure is, as in experiments, primarily dependent on the mass ratio of material to explosive, with the particle size, density, and initial porosity of the particle bed playing secondary roles. In the near field, the blast overpressure decreases sharply with distance as the particles are accelerated by the flow. When the particles decelerate due to drag, energy is returned to the flow and the peak blast overpressure recovers and reaches values similar to that of a bare explosive charge for low mass ratios. Time-distance trajectory plots of the particle and blast wave motion with the pressure field superimposed, illustrate the weak pressure waves generated by the motion of the particle layer which travel upstream and perturb the blast wave motion. Computation of the particle and gas momentum flux in the multiphase

  7. Numerical investigation of particle-blast interaction during explosive dispersal of liquids and granular materials

    Science.gov (United States)

    Pontalier, Q.; Lhoumeau, M.; Milne, A. M.; Longbottom, A. W.; Frost, D. L.

    2018-05-01

    Experiments show that when a high-explosive charge with embedded particles or a charge surrounded by a layer of liquid or granular material is detonated, the flow generated is perturbed by the motion of the particles and the blast wave profile differs from that of an ideal Friedlander form. Initially, the blast wave overpressure is reduced due to the energy dissipation resulting from compaction, fragmentation, and heating of the particle bed, and acceleration of the material. However, as the blast wave propagates, particle-flow interactions collectively serve to reduce the rate of decay of the peak blast wave overpressure. Computations carried out with a multiphase hydrocode reproduce the general trends observed experimentally and highlight the transition between the particle acceleration/deceleration phases, which is not accessible experimentally, since the particles are obscured by the detonation products. The dependence of the particle-blast interaction and the blast mitigation effectiveness on the mitigant to explosive mass ratio, the particle size, and the initial solid volume fraction is investigated systematically. The reduction in peak blast overpressure is, as in experiments, primarily dependent on the mass ratio of material to explosive, with the particle size, density, and initial porosity of the particle bed playing secondary roles. In the near field, the blast overpressure decreases sharply with distance as the particles are accelerated by the flow. When the particles decelerate due to drag, energy is returned to the flow and the peak blast overpressure recovers and reaches values similar to that of a bare explosive charge for low mass ratios. Time-distance trajectory plots of the particle and blast wave motion with the pressure field superimposed, illustrate the weak pressure waves generated by the motion of the particle layer which travel upstream and perturb the blast wave motion. Computation of the particle and gas momentum flux in the multiphase

  8. EXPERIMENTAL INVESTIGATIONS OF INTERACTION OF TRACK AND ROLLING STOCK ON CROSSOVERS

    Directory of Open Access Journals (Sweden)

    M. A. Arbuzov

    2016-10-01

    Full Text Available Purpose. Recently on the Ukrainian railways network more attention is paid to the cases of violations in the maintenance of crossovers, which may lead to deterioration of the train traffic safety conditions. As a rule, such violations occur as a result of inaccuracies during crossover pegging and laying, as well as are the consequence of impact of rolling stock and thermal forces. The appearance of geometrical irregularities can also be triggered by violation of the scheme of layout of concrete sleepers in the crossover turnout curve with intertrack spaces of less than 5.3 m. Therefore, we have decided to analyze the impact of the presence of deviations from the layout scheme of the sleepers and geometric irregularities on the conditions of track and rolling stock interaction based on the results of experimental investigations. It was also decided to establish a connection between the stress-strain states of the track and the presence of short sleepers. Methodology. The effect of deviations from the layout scheme of the sleepers and geometric irregularities on the interaction conditions of track and rolling stock was studied by means of theoretical calculations and experimental research. The experimental research covered the area on the non-public railway tracks that meets the required conditions for scientific and research work on the territory of «Transinvestservice» company. Findings. The distribution of stresses and forces acting on a railway track depending on speed movement of experienced rolling stock was obtained. In addition we obtained the data on the influence of the sleeper geometric parameters on its stress-strain state. Originality. For the first time the paper assessed the impact of rolling stock in the presence of geometrical irregularities and asymmetrically truncated sleepers within the crossover connection part on the stress-strain state of track in this zone. In addition, we compared the results for the area with common and

  9. Challenges of the Modeling Methods for Investigating the Interaction between the CNT and the Surrounding Polymer

    Directory of Open Access Journals (Sweden)

    Roham Rafiee

    2013-01-01

    Full Text Available The interaction between the carbon nanotubes (CNT and the polymer is a key factor for determining the mechanical, thermal, and electrical properties of the CNT/polymer nanocomposite. However, it is difficult to measure experimentally the interfacial bonding properties between the CNT and the surrounding polymer. Therefore, computational modeling is used to predict the interaction properties. Different scale models, from atomistic to continuum, are critically reviewed addressing the advantages, the disadvantages, and the future challenges. Various methods of improvement for measuring the interaction properties are described. Finally, it is concluded that the semicontinuum modeling may be the best candidate for modeling the interaction between the CNT and the polymer.

  10. From bulk soil to intracrystalline investigation of plant-mineral interaction

    Science.gov (United States)

    Lemarchand, D.; Voinot, A.; Chabaux, F.; Turpault, M.

    2011-12-01

    Understanding the controls and feedbacks regulating the flux of matter between bio-geochemical reservoirs in forest ecosystems receives a fast growing interest for the last decades. A complex question is to understand how minerals and vegetation interact in soils to sustain life and, to a broader scope, how forest ecosystems may respond to human activity (acid rain, harvesting,...) and climate perturbations (temperature, precipitation,...). Many mineralogical and biogeochemical approaches have longtime been developed, and occasionally coupled, in order to investigate the mechanisms by which chemical elements either are exchanged between soil particles and solutions, or are transferred to plants or to deeper soil layers and finally leave the system. But the characterization of particular processes like the contribution of minor reactive minerals to plant nutrition and global fluxes or the mechanisms by which biology can modify reaction rates and balance the bioavailability of nutrients in response to environmental perturbation sometimes fails because of the lack of suitable tracers. Recent analytical and conceptual advances have opened new perspectives for the use of light "non traditional" stable isotopes. Showing a wild range of concentrations and isotopic compositions between biogeochemical reservoirs in forest ecosystem, boron has physico-chemical properties particularly relevant to the investigation of water/rock interactions even when evolving biologically-mediated reactions. In this study, we focused on the distribution of boron isotopes from intracrystalline to bulk soil scales. An overview of the boron distribution and annual fluxes in the soil-plant system clearly indicates that the vegetation cycling largely controls the mobility of boron. We also observe that the mineral and biological B pools have drastically different isotopic signature that makes the transfer of B between them very easy to follow. In particular, the podzol soil we analyzed shows a

  11. Investigating the biogeochemical interactions involved in simultaneous TCE and Arsenic in situ bioremediation

    Science.gov (United States)

    Cook, E.; Troyer, E.; Keren, R.; Liu, T.; Alvarez-Cohen, L.

    2016-12-01

    The in situ bioremediation of contaminated sediment and groundwater is often focused on one toxin, even though many of these sites contain multiple contaminants. This reductionist approach neglects how other toxins may affect the biological and chemical conditions, or vice versa. Therefore, it is of high value to investigate the concurrent bioremediation of multiple contaminants while studying the microbial activities affected by biogeochemical factors. A prevalent example is the bioremediation of arsenic at sites co-contaminated with trichloroethene (TCE). The conditions used to promote a microbial community to dechlorinate TCE often has the adverse effect of inducing the release of previously sequestered arsenic. The overarching goal of our study is to simultaneously evaluate the bioremediation of arsenic and TCE. Although TCE bioremediation is a well-understood process, there is still a lack of thorough understanding of the conditions necessary for effective and stable arsenic bioremediation in the presence of TCE. The objective of this study is to promote bacterial activity that stimulates the precipitation of stable arsenic-bearing minerals while providing anaerobic, non-extreme conditions necessary for TCE dechlorination. To that end, endemic microbial communities were examined under various conditions to attempt successful sequestration of arsenic in addition to complete TCE dechlorination. Tested conditions included variations of substrates, carbon source, arsenate and sulfate concentrations, and the presence or absence of TCE. Initial arsenic-reducing enrichments were unable to achieve TCE dechlorination, probably due to low abundance of dechlorinating bacteria in the culture. However, favorable conditions for arsenic precipitation in the presence of TCE were eventually discovered. This study will contribute to the understanding of the key species in arsenic cycling, how they are affected by various concentrations of TCE, and how they interact with the key

  12. Investigating the potassium interactions with the palytoxin induced channels in Na+/K+ pump.

    Science.gov (United States)

    Rodrigues, Antônio M; Almeida, Antônio-Carlos G; Infantosi, Antonio F C; Teixeira, Hewerson Z; Duarte, Mário A

    2009-02-01

    K(+) has been appointed as the main physiological inhibitor of the palytoxin (PTX) effect on the Na(+)/K(+) pump. This toxin acts opening monovalent cationic channels through the Na(+)/K(+) pump. We investigate, by means of computational modeling, the kinetic mechanisms related with K(+) interacting with the complex PTX-Na(+)/K(+) pump. First, a reaction model, with structure similar to Albers-Post model, describing the functional cycle of the pump, was proposed for describing K(+) interference on the complex PTX-Na(+)/K(+) pump in the presence of intracellular ATP. A mathematic model was derived from the reaction model and it was possible to solve numerically the associated differential equations and to simulate experimental maneuvers about the PTX induced currents in the presence of K(+) in the intra- and extracellular space as well as ATP in the intracellular. After the model adjusting to the experimental data, a Monte Carlo method for sensitivity analysis was used to analyze how each reaction parameter acts during each experimental maneuver involving PTX. For ATP and K(+) concentrations conditions, the simulations suggest that the enzyme substate with ATP bound to its high-affinity sites is the main substate for the PTX binding. The activation rate of the induced current is limited by the K(+) deocclusion from the PTX-Na(+)/K(+) pump complex. The K(+) occlusion in the PTX induced channels in the enzymes with ATP bound to its low-affinity sites is the main mechanism responsible for the reduction of the enzyme affinity to PTX.

  13. Molten corium concrete interaction: investigation of heat transfer in two-phase flow

    International Nuclear Information System (INIS)

    Amizic, Milan

    2014-01-01

    In the context of severe accident research for the second and the third generation of nuclear power plants, there are still open issues concerning some aspects of the concrete cavity ablation during the molten corium - concrete interaction (MCCI). The determination of heat transfer along the interfacial region between the molten corium pool and the ablating basemat concrete is crucial for the assessment of concrete ablation progression and eventually the basemat melt through. For the purpose of experimental investigation of thermal hydraulics inside a liquid pool agitated by gas bubbles, the CLARA project has been launched. The CLARA experiments are performed using simulant materials and they reveal the influence of superficial gas velocity, liquid viscosity and pool geometry on the heat transfer coefficient between the internally heated liquid pool and vertical and horizontal pool walls maintained at uniform temperature. The first test campaign has been conducted with the small pool configuration (50 cm * 25 cm * 25 cm). The tests have been performed with liquids covering a wide range of dynamic viscosity from approximately 1 mPa s to 10000 mPa s and the superficial gas velocity is varied up to 8 cm/s. This thesis comprises a brief description of MCCI phenomenology, literature reviews on the existing heat transfer correlations for two phase flow and the void fraction, a description of CLARA setup, experimental results and their interpretation. The experimental results are compared with existing models and some new models for the assessment of heat transfer coefficient in two-phase flow. (author) [fr

  14. Investigation on oxidative stress of nitric oxide synthase interacting protein from Clonorchis sinensis.

    Science.gov (United States)

    Bian, Meng; Xu, Qingxia; Xu, Yanquan; Li, Shan; Wang, Xiaoyun; Sheng, Jiahe; Wu, Zhongdao; Huang, Yan; Yu, Xinbing

    2016-01-01

    Numerous evidences indicate that excretory-secretory products (ESPs) from liver flukes trigger the generation of free radicals that are associated with the initial pathophysiological responses in host cells. In this study, we first constructed a Clonorchis sinensis (C. sinensis, Cs)-infected BALB/c mouse model and examined relative results respectively at 3, 5, 7, and 9 weeks postinfection (p.i.). Quantitative reverse transcription (RT)-PCR indicated that the transcriptional level of both endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD) gradually decreased with lastingness of infection, while the transcriptional level of inducible NOS (iNOS) significantly increased. The level of malondialdehyde (MDA) in sera of infected mouse significantly increased versus the healthy control group. These results showed that the liver of C. sinensis-infected mouse was in a state with elevated levels of oxidation stress. Previously, C. sinensis NOS interacting protein coding gene (named CsNOSIP) has been isolated and recombinant CsNOSIP (rCsNOSIP) has been expressed in Escherichia coli, which has been confirmed to be a component present in CsESPs and confirmed to play important roles in immune regulation of the host. In the present paper, we investigated the effects of rCsNOSIP on the lipopolysaccharide (LPS)-induced activated RAW264.7, a murine macrophage cell line. We found that endotoxin-free rCsNOSIP significantly promoted the levels of nitric oxide (NO) and reactive oxygen species (ROS) after pretreated with rCsNOSIP, while the level of SOD decreased. Furthermore, rCsNOSIP could also increase the level of lipid peroxidation MDA. Taken together, these results suggested that CsNOSIP was a key molecule which was involved in the production of nitric oxide (NO) and its reactive intermediates, and played an important role in oxidative stress during C. sinensis infection.

  15. Spectroscopic investigation on the interaction of some surfactant-cobalt(III) complexes with serum albumins

    Energy Technology Data Exchange (ETDEWEB)

    Vignesh, Gopalaswamy; Nehru, Selvan; Manojkumar, Yesaiyan; Arunachalam, Sankaralingam, E-mail: arunasurf@yahoo.com

    2014-01-15

    The interaction of HSA/BSA with single and double chain surfactant-cobalt(III) complexes, cis-[Co(phen){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (1), cis-[Co(phen){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (2), cis-[Co(en){sub 2}(UA)Cl](ClO{sub 4}){sub 2}·2H{sub 2}O (3), cis-[Co(en){sub 2}(UA){sub 2}](ClO{sub 4}){sub 3}·2H{sub 2}O (4), were investigated by steady state fluorescence, UV–vis absorption, synchronous, three dimensional fluorescence and circular dichroism spectroscopy. The results reveal that the quenching of HSA/BSA by all the four complexes takes place through static mechanism. The binding constant, binding sites and thermodymamic parameter were calculated. The results illustrate that the double chain surfactant-cobalt(III) complexes bind more strongly than the corresponding single chain complexes. The distance between donor (HSA/BSA) and acceptor (surfactant-cobalt(III) complexes) was obtained according to FRET. The results of synchronous, three dimensional and circular dichroism spectroscopy studies show that all the complexes caused considerable amount of conformational and some amount of environment changes in HSA/BSA. -- Highlights: • Binding of single and double chain surfactant-cobalt(III) complexes with serum albumins. • Hydrophobic attraction plays a major role in the binding process. • Binding induces considerable amount of conformational changes in the protein.

  16. Detailed NMR investigation of cyclodextrin-perfluorinated surfactant interactions in aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Weiss-Errico, Mary Jo; O’Shea, Kevin E., E-mail: osheak@fiu.edu

    2017-05-05

    Highlights: • Perfluorochemicals (PFCs) are strongly encapsulated by cyclodextrins (CDs). • Competition studies confirm strong CD:PFC host-guest interactions. • {sup 19}F NMR Spectroscopy demonstrates association constants up to 10{sup 5} M{sup −1}. • Position of CD along PFC chain is elucidated from NMR results. • CD:PFC complex is not disturbed under a variety of water quality conditions. - Abstract: Perfluorochemicals (PFCs) are contaminants of serious concern because of their toxicological properties, widespread presence in drinking water sources, and incredible stability in the environment. To assess the potential application of α-, β-, and γ-cyclodextrins for PFC remediation, we investigated their complexation with linear fluorinated carboxylic acids, sulfonates, and a sulfonamide with carbon backbones ranging from C4-C9. {sup 19}F Nuclear Magnetic Resonance (NMR) spectroscopy studies demonstrated β-CD formed the strongest complexes with these PFCs. The polar head group had a modest influence, but for PFCs with backbones longer than six carbons, strong association constants are observed for 1:1 (K{sub 1:1} ∼ 10{sup 5} M{sup −1}) and 2:1 (K{sub 2:1} ∼ 10{sup 3} M{sup −1}) β-CD:PFC complexes. Excess β-CD can be used to complex 99.5% of the longer chain PFCs. Competition studies with adamantane-carboxylic acid and phenol confirmed the nature and persistence of the β-CD:PFC complex. Detailed analyses of the individual NMR chemical shifts and Job plots indicate the favored positions of the β-CD along the PFC chain. Solution pH, ionic strength, and the presence of humic acid have modest influence on the β-CD:PFC complexes. The strong encapsulation of PFCs by β-CD under a variety of water quality conditions demonstrates the tremendous potential of CD-based materials for the environmental remediation of PFCs.

  17. [Investigation on the interaction between pentadecafluorooctanoic acid and human serum albumin by capillary electrophoresis].

    Science.gov (United States)

    Gu, Yi; Guo, Ming; Lü, Da; Hou, Ping; Yin, Xinxin

    2018-01-08

    Capillary electrophoresis (CE) has been used to establish the analytical method of interaction between pentadecafluorooctanoic acid (PFOA) and human serum albumin (HSA). Under the physiological conditions, the interaction model of PFOA and HSA were constructed. Mobility method, plug-plug kinetic (PPK) method and simplified Hummel-Dreyer method were used to determine the interaction between derivatives and HSA. Non-linear regression, Scatchard equation and Klotz equation were adopted to obtain the interaction parameters. The results showed that all the three methods can be used to analyze the interaction of PFOA-HSA system. According to the interaction parameters, the most suitable CE method is simplified Hummel-Dreyer method while the most suitable theoretical equation is non-linear regression. The binding parameters indicated that the interaction of PFOA-HSA system has only one type of binding sites and the binding is stable. The research results have illustrated the interaction between HSA and PFOA, and provided a beneficial reference for in-depth research of the toxic mechanism of PFOA.

  18. INVESTIGATING THE ROLE OF PDZ-DOMAIN INTERACTIONS FOR DOPAMINE TRANSPORTER FUNCTION

    DEFF Research Database (Denmark)

    Fog, Jacob; Vægter, Christian Bjerggaard; Gether, Ulrik

    canonical PDZ domain interactions with proteins such as PICK1. To clarify the actual role of PDZ domain interactions for DAT function we have expressed the wild type DAT and a number of C-terminal mutants either alone or together with PICK1 in HEK293, N2A neuroblastoma and PC12 cells. Data obtained from...

  19. Investigating Learning with an Interactive Tutorial: A Mixed-Methods Strategy

    Science.gov (United States)

    de Villiers, M. R.; Becker, Daphne

    2017-01-01

    From the perspective of parallel mixed-methods research, this paper describes interactivity research that employed usability-testing technology to analyse cognitive learning processes; personal learning styles and times; and errors-and-recovery of learners using an interactive e-learning tutorial called "Relations." "Relations"…

  20. Investigation of the influence of intermolecular interactions on the electronic stopping cross sections

    International Nuclear Information System (INIS)

    Krotz, R.; Neuwirth, W.; Pietsch, W.

    1980-01-01

    The electronic stopping cross sections for Li projectiles have been measured in various kinds of targets. They are analyzed here with respect to the different types of interactions between the constituents of the target: interactions between the atoms in a compound (chemical bonding), the ion-dipole interaction, if the target is an electrolytic solution, and the dipole-dipole interaction among polar molecules. The influence on the stopping cross section depends on the strength of these interactions; it varies from a few percent in the latter case up to 20% and more in a compound. These influences are the largest, if the velocity of the projectile is of the order of the average orbital velocity of the target atoms. (author)

  1. Investigation of the heparin-thrombin interaction by dynamic force spectroscopy.

    Science.gov (United States)

    Wang, Congzhou; Jin, Yingzi; Desai, Umesh R; Yadavalli, Vamsi K

    2015-06-01

    The interaction between heparin and thrombin is a vital step in the blood (anti)coagulation process. Unraveling the molecular basis of the interactions is therefore extremely important in understanding the mechanisms of this complex biological process. In this study, we use a combination of an efficient thiolation chemistry of heparin, a self-assembled monolayer-based single molecule platform, and a dynamic force spectroscopy to provide new insights into the heparin-thrombin interaction from an energy viewpoint at the molecular scale. Well-separated single molecules of heparin covalently attached to mixed self-assembled monolayers are demonstrated, whereby interaction forces with thrombin can be measured via atomic force microscopy-based spectroscopy. Further these interactions are studied at different loading rates and salt concentrations to directly obtain kinetic parameters. An increase in the loading rate shows a higher interaction force between the heparin and thrombin, which can be directly linked to the kinetic dissociation rate constant (koff). The stability of the heparin/thrombin complex decreased with increasing NaCl concentration such that the off-rate was found to be driven primarily by non-ionic forces. These results contribute to understanding the role of specific and nonspecific forces that drive heparin-thrombin interactions under applied force or flow conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

  2. Numerical Investigation of Compressor Non-Synchronous Vibration with Full Annulus Rotor-Stator Interaction

    Science.gov (United States)

    Espinal, Daniel

    The objective of this research is to investigate and confirm the periodicity of the Non-Synchronous Vibration (NSV) mechanism of a GE axial compressor with a full-annulus simulation. A second objective is to develop a high fidelity single-passage tool with time-accurate unsteady capabilities able to capture rotor-stator interactions and NSV excitation response. A high fidelity methodology for axial turbomachinery simulation is developed using the low diffusion shock-capturing Riemann solver with high order schemes, the Spalart-Allmaras turbulence closure model, the fully conservative unsteady sliding BC for rotor-stator interaction with extension to full-annulus and single-passage configurations, and the phase lag boundary conditions applied to rotor-stator interface and circumferential BC. A URANS solver is used and captures the NSV flow excitation frequency of 2439 Hz, which agrees reasonably well with the measured NSV frequency of 2600 Hz from strain gage test data. It is observed that the circumferentially traveling vortex formed in the vicinity of the rotor tip propagates at the speed of a non-engine order frequency and causes the NSV. The vortex travels along the suction surface of the blade and crosses the passage outlet near blade trailing edge. Such a vortex motion trajectory repeats in each blade passage and generates two low pressure regions due to the vortex core positions, one at the leading edge and one at the trailing edge, both are oscillating due to the vortex coming and leaving. These two low pressure regions create a pair of coupling forces that generates a torsion moment causing NSV. The full-annulus simulation shows that the circumferentially traveling vortex has fairly periodical behavior and is a full annulus structure. Also, frequencies below the NSV excitation frequency of 2439 Hz with large amplitudes in response to flow-separation related phenomena are present. This behavior is consistent with experimental measurements. For

  3. Conversation analysis as a method for investigating interaction in care home environments.

    Science.gov (United States)

    Chatwin, John

    2014-11-01

    This article gives an outline of how the socio-linguistic approach of conversation analysis can be applied to the analysis of carer-patient interaction in care homes. A single case study from a routine encounter in a residential care home is presented. This is used to show how the conversation analysis method works, the kinds of interactional and communication features it can expose, and what specific contribution this kind of micro-interactional approach may make to improving quality of care in these environments. © The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

  4. Electron spin interactions in chemistry and biology fundamentals, methods, reactions mechanisms, magnetic phenomena, structure investigation

    CERN Document Server

    Likhtenshtein, Gertz

    2016-01-01

    This book presents the versatile and pivotal role of electron spin interactions in nature. It provides the background, methodologies and tools for basic areas related to spin interactions, such as spin chemistry and biology, electron transfer, light energy conversion, photochemistry, radical reactions, magneto-chemistry and magneto-biology. The book also includes an overview of designing advanced magnetic materials, optical and spintronic devices and photo catalysts. This monograph appeals to scientists and graduate students working in the areas related to spin interactions physics, biophysics, chemistry and chemical engineering.

  5. Investigating Cross-Device Interaction between a Handheld Device and a Large Display

    DEFF Research Database (Denmark)

    Paay, Jeni; Raptis, Dimitrios; Kjeldskov, Jesper

    2017-01-01

    and mid-air gestures, pinching, swiping, swinging and flicking. We look specifically at their relative efficiency, effectiveness and accuracy in bi-directional interaction between a smartphone and large display in a point-click context. We report findings from two user studies, which show that swiping...... is both most effective, fastest and most accurate, closely followed by swinging. What these two approaches have in common is the ability to keep the pointer steady on the large display, unaffected by concurrent gestures or body movements used to complete the interaction, suggesting...... that this is an important factor for designing effective cross-device interaction with large displays....

  6. Investigations of fuel cladding chemical interaction in irradiated LMFBR type oxide fuel pins

    International Nuclear Information System (INIS)

    Roake, W.E.; Adamson, M.G.; Hilbert, R.F.; Langer, S.

    1977-01-01

    Understanding and controlling the chemical attack of fuel pin cladding by fuel and fission products are major objectives of the U.S. LMFBR Mixed Oxide Irradiation Testing Program. Fuel-cladding chemical interaction (FCCI) has been recognized as an important factor in the ability to achieve goal peak burnups of 8% (80.MWd/kg) in FFTF and in excess of 10% (100.MWd/kg) in the LMFBR demonstration reactors while maintaining coolant bulk outlet temperatures up to ∼60 deg. C (1100 deg. F). In this paper we review pertinent parts of the irradiation program and describe recent observation of FCCI in the fuel pins of this program. One goal of the FCCI investigations is to obtain a sufficiently quantitative understanding of FCCI such that correlations can be developed relating loss of effective cladding thickness to irradiation and fuel pin fabrication parameters. Wastage correlations being developed using different approaches are discussed. Much of the early data on FCCI obtained in the U.S. Mixed Oxide Fuel Program came from capsule tests irradiated in both fast and thermal flux facilities. The fast flux irradiated encapsulated fuel pins continue to provide valuable data and insight into FCCI. Currently, however, bare pins with prototypic fuels and cladding irradiated in the fast flux Experimental Breeder Reactor-II (EBR-II) as multiple pin assemblies under prototypic powers, temperatures and thermal gradients are providing growing quantities of data on FCCI characteristics and cladding thickness losses from FCCI. A few special encapsulated fuel pin tests are being conducted in the General Electric Test Reactor (GETR) and EBR-II, but these are aimed at providing specific information under irradiation conditions not achievable in the fast flux bare pin assemblies or because EBR-II Operation or Safety requirements dictate that the pins be encapsulated. The discussion in this paper is limited to fast flux irradiation test results from encapsulated pins and multiple pin

  7. Ozone-surface interactions: Investigations of mechanisms, kinetics, mass transport, and implications for indoor air quality

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, Glenn Charles [Univ. of California, Berkeley, CA (United States)

    1999-12-01

    In this dissertation, results are presented of laboratory investigations and mathematical modeling efforts designed to better understand the interactions of ozone with surfaces. In the laboratory, carpet and duct materials were exposed to ozone and measured ozone uptake kinetics and the ozone induced emissions of volatile organic compounds. To understand the results of the experiments, mathematical methods were developed to describe dynamic indoor aldehyde concentrations, mass transport of reactive species to smooth surfaces, the equivalent reaction probability of whole carpet due to the surface reactivity of fibers and carpet backing, and ozone aging of surfaces. Carpets, separated carpet fibers, and separated carpet backing all tended to release aldehydes when exposed to ozone. Secondary emissions were mostly n-nonanal and several other smaller aldehydes. The pattern of emissions suggested that vegetable oils may be precursors for these oxidized emissions. Several possible precursors and experiments in which linseed and tung oils were tested for their secondary emission potential were discussed. Dynamic emission rates of 2-nonenal from a residential carpet may indicate that intermediate species in the oxidation of conjugated olefins can significantly delay aldehyde emissions and act as reservoir for these compounds. The ozone induced emission rate of 2-nonenal, a very odorous compound, can result in odorous indoor concentrations for several years. Surface ozone reactivity is a key parameter in determining the flux of ozone to a surface, is parameterized by the reaction probability, which is simply the probability that an ozone molecule will be irreversibly consumed when it strikes a surface. In laboratory studies of two residential and two commercial carpets, the ozone reaction probability for carpet fibers, carpet backing and the equivalent reaction probability for whole carpet were determined. Typically reaction probability values for these materials were 10

  8. Investigations of fuel cladding chemical interaction in irradiated LMFBR type oxide fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Roake, W E [Westinghouse-Hanford Co., Richland, WA (United States); Adamson, M G [General Electric Company, Vallecitos Nuclear Center, Pleasanton, CA (United States); Hilbert, R F; Langer, S

    1977-04-01

    Understanding and controlling the chemical attack of fuel pin cladding by fuel and fission products are major objectives of the U.S. LMFBR Mixed Oxide Irradiation Testing Program. Fuel-cladding chemical interaction (FCCI) has been recognized as an important factor in the ability to achieve goal peak burnups of 8% (80.MWd/kg) in FFTF and in excess of 10% (100.MWd/kg) in the LMFBR demonstration reactors while maintaining coolant bulk outlet temperatures up to {approx}60 deg. C (1100 deg. F). In this paper we review pertinent parts of the irradiation program and describe recent observation of FCCI in the fuel pins of this program. One goal of the FCCI investigations is to obtain a sufficiently quantitative understanding of FCCI such that correlations can be developed relating loss of effective cladding thickness to irradiation and fuel pin fabrication parameters. Wastage correlations being developed using different approaches are discussed. Much of the early data on FCCI obtained in the U.S. Mixed Oxide Fuel Program came from capsule tests irradiated in both fast and thermal flux facilities. The fast flux irradiated encapsulated fuel pins continue to provide valuable data and insight into FCCI. Currently, however, bare pins with prototypic fuels and cladding irradiated in the fast flux Experimental Breeder Reactor-II (EBR-II) as multiple pin assemblies under prototypic powers, temperatures and thermal gradients are providing growing quantities of data on FCCI characteristics and cladding thickness losses from FCCI. A few special encapsulated fuel pin tests are being conducted in the General Electric Test Reactor (GETR) and EBR-II, but these are aimed at providing specific information under irradiation conditions not achievable in the fast flux bare pin assemblies or because EBR-II Operation or Safety requirements dictate that the pins be encapsulated. The discussion in this paper is limited to fast flux irradiation test results from encapsulated pins and multiple pin

  9. Investigating “Locality” of Intra-Urban Spatial Interactions in New York City Using Foursquare Data

    Directory of Open Access Journals (Sweden)

    Yeran Sun

    2016-03-01

    Full Text Available Thanks to the increasing popularity of location-based social networks, a large amount of user-generated geo-referenced check-in data is now available, and such check-in data is becoming a new data source in the study of mobility and travel. Conventionally, spatial interactions between places were measured based on the trips made between them. This paper empirically investigates the use of social media data (i.e., Foursquare data to study the “locality” of such intra-urban spatial interactions in New York City, and specifically: (i the level of “locality” of spatial interactions; (ii the impacts of personal characteristics on “locality” of spatial interaction and finally; (iii the heterogeneity in spatial distribution of “local” interactions. The results of this study indicate that: (1 spatial interactions show a high degree of locality; (2 gender does not have a considerable impact on the locality of spatial interactions and finally; (3 “local” interactions likely cluster in some places within the research city.

  10. Some experimental results of the investigation of hadron-nucleus and nucleus-nucleus interactions

    International Nuclear Information System (INIS)

    Azimov, S.A.; Gulamov, K.G.; Chernov, G.M.

    1978-01-01

    Recent experimental data on the hadron-nucleus and nucleus-nucleus inelastic interactions are analyzed. A particular attention is paid to the description of the leading hadron spectra and of the spectra of nucleon recoils in hadron-nucleus interactions. Some of the results of the experimental studies of correlations between secondary particles are discussed. This discussion demonstrates that an analysis of the multiparticle phenomena is very promising regarding the discrimination between the different models for the hadron-nucleus and nucleus-nucleus interactions. It is pointed out that the actual mechanism of the hadron-nucleus and nucleus-nucleus interactions is a rather complex one and can be described comprehensively by none of the existing models

  11. Investigation of inelastic interactions of 400 GeV protons with emulsion nuclei

    International Nuclear Information System (INIS)

    Boos, E.G.

    1978-01-01

    Proton-nucleus (pA) interactions registered in nuclear emulsion irradiated at the Batavian accelerator at 400 GeV/c are analyzed. Presented are energy dependences of some main parameters of hadron-nucleus (hA) interactions using experimental data on pA interactions for lesser energies. Quantitative and qualitative data comparison with predictions of a series of popular models of multiple particle production resulted from collisions with nuclei has been carried out. It is shown that most models can not explain all the experimental results. An analysis of the experimental data obtained permits to suggest that the production mechanism in hA interactions has two- or multi-component character

  12. A DFT investigation on interactions between asymmetric derivatives of cisplatin and nucleobase guanine

    Science.gov (United States)

    Tai, Truong Ba; Nhat, Pham Vu

    2017-07-01

    The interactions of hydrolysis products of cisplatin and its asymmetric derivatives cis- and trans-[PtCl2(iPram)(Mepz)] with guanine were studied using DFT methods. These interactions are dominated by electrostatic effects, namely hydrogen bond contributions and there exists a charge flow from H-atoms of ligands to the O-atoms of guanine. The replacement of NH3 moieties by larger functional groups accompanies with a moderate reaction between PtII and guanine molecule, diminishing the cytotoxicity of the drug. The asymmetric and symmetric NH2 stretching modes of complexes having strong hydrogen bond interactions are red shifted importantly as compared to complexes without presence of hydrogen bond interactions.

  13. An Investigation of the Interaction Effects of Acute Self-Esteem and Perceived Competence on Conformity.

    Science.gov (United States)

    1978-12-22

    a demonstration of the interaction effects of acute self - esteem and perceived competence. Acute self - esteem manipulations (high, low or no) were...On the basis of previous research on conformity it was predicted that subjects who were subjected to acute self - esteem manipulations and perceived...role in conformity. The main effect of self - esteem and the interaction of self - esteem and perceived competence did not prove significant. Results were

  14. Investigation of the interaction of ferromagnetic fluids with proteins by dynamic light scattering

    Science.gov (United States)

    Velichko, Elena; Nepomnyashchaya, Elina; Dudina, Alina; Pleshakov, Ivan; Aksenov, Evgenii

    2018-04-01

    In this article the interaction between ionically stabilized magnetic nanoparticles and blood serum albumin proteins in liquid medium are discussed. Some distributions of nanoparticles' agglomerate sizes in solutions of albumin molecules, magnetic nanoparticles and their mixtures both under the influence of magnetic field and free from it are presented. It is shown that magnetic nanoparticles interact with albumin molecules, forming agglomerates. It is also shown that at the influence of magnetic field sizes of agglomerates increase proportionally to the magnetic field density.

  15. Experimental and mathematical modeling methods for the investigation of toxicological interactions

    International Nuclear Information System (INIS)

    El-Masri, Hisham A.

    2007-01-01

    While procedures have been developed and used for many years to assess risk and determine acceptable exposure levels to individual chemicals, most cases of environmental contamination can result in concurrent or sequential exposure to more than one chemical. Toxicological predictions of such combinations must be based on an understanding of the mechanisms of action and interaction of the components of the mixtures. Statistical and experimental methods test the existence of toxicological interactions in a mixture. However, these methods are limited to experimental data ranges for which they are derived, in addition to limitations caused by response differences from experimental animals to humans. Empirical methods such as isobolograms, median-effect principle and response surface methodology (RSM) are based on statistical experimental design and regression of data. For that reason, the predicted response surfaces can be used for extrapolation across dose regions where interaction mechanisms are not anticipated to change. In general, using these methods for predictions can be problematic without including biologically based mechanistic descriptions that can account for dose and species differences. Mechanistically based models, such as physiologically based pharmacokinetic/pharmacodynamic (PBPK/PD) models, include explicit descriptions of interaction mechanisms which are related to target tissues levels. These models include dose-dependent mechanistic hypotheses of toxicological interactions which can be tested by model-directed experimental design and used to identify dose regions where interactions are not significant

  16. Numerical investigation of interaction between rising bubbles in a viscous liquid

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Ik Roh [Korea Institute of Marine Science and Technology Promotion, Seoul (Korea, Republic of); Shin Seung Won [Hongik University, Seoul (Korea, Republic of)

    2016-07-15

    The rising behavior of bubbles undergoing bubble-bubble interaction in a viscous liquid is studied using a two-dimensional direct numerical simulation. Level contour reconstruction method (LCRM), one of the connectivity-free front tracking methods, is applied to describe a moving interface accurately under highly deformable conditions. This work focuses on the effects of bubble size on the interaction of two bubbles rising side-by-side in a stagnant liquid. Several characteristics of bubble-bubble interaction are analyzed quantitatively as supported by energy analysis. The results showed clear differences between small and large bubbles with respect to their interaction behavior in terms of lateral movement, vortex intensity, suppression of surface deformation, and viscous dissipation rate. Distributions of vorticity and viscous dissipation rate near the bubble interfaces also differed depending on the size of the bubbles. Strong vortices from large bubbles triggered oscillation in bubble-bubble interaction and played a dominant role in the interaction process as the size of bubbles increases.

  17. Combined experimental and theoretical investigation of interactions between kaolinite inner surface and intercalated dimethyl sulfoxide

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Shuai [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Liu, Qinfu, E-mail: lqf@cumtb.edu.cn [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Cheng, Hongfei [School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083 (China); Zeng, Fangui [Department of Earth Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2015-03-15

    Graphical abstract: Snapshot of the kaolinite–DMSO system after equilibrium is reached. - Highlights: • Dimethyl sulfoxide arranges a monolayer structure between kaolinite layers. • Weak hydrogen bonds exist between methyl groups of dimethyl sulfoxide and kaolinite silica layer. • Intercalated dimethyl sulfoxide forms strong hydrogen bonds with kaolinite alumina layer. - Abstract: Kaolinite intercalation complex with dimethyl sulfoxide (DMSO) was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetry–differential scanning calorimetry (TG–DSC) combined with molecular dynamics simulation. The bands assigned to the OH stretching of inner surface of kaolinite were significantly perturbed after intercalation of DMSO into kaolinite. Additionally, the bands attributed to the vibration of gibbsite-like layers of kaolinite shifted to the lower wave number, indicating that the intercalated DMSO were strongly hydrogen bonded to the alumina octahedral surface of kaolinite. The slightly decreased intensity of 1031 cm{sup −1} and 1016 cm{sup −1} band due to the in-plane vibration of Si−O of kaolinite revealed that some DMSO molecules formed weak hydrogen bonds with the silicon tetrahedral surface of kaolinite. Based on the TG result of kaolinite–DMSO intercalation complex, the formula of A1{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}(DMSO){sub 0.7} was obtained, with which the kaolinite–DMSO complex model was constructed. The molecular dynamics simulation of kaolinite–DMSO complex directly confirmed the monolayer structure of DMSO in interlayer space of kaolinite, where the DMSO arranged almost parallel with kaolinite basal surface with all methyl groups being distributed near the interlayer midplane and oxygen atoms orienting toward to the alumina octahedral surface. The radial distribution function between kaolinite and intercalated DMSO verified the strong hydrogen bonds forming between hydroxyl hydrogen

  18. Synthesis, Characterization and Functionalization of Polymeric Nanoparticles and Investigation of the Interaction with Biological Systems

    International Nuclear Information System (INIS)

    Bleul, Regina

    2015-01-01

    One of the main goals of nanomedicine is to improve the treatment of hazardous diseases whose conventional therapy often has serious side effects. The vision is to create a theranostic drug delivery system which is capable of safely transporting therapeutic cargo through the body to a targeted site of disease at which point the drug is released. Furthermore, it is desirable to track the carrier in real time which would allow for a personal adjustment of the therapy. Studies on the behavior of nanoparticulate substances in a physiological environment form the basis for the possibility to successfully develop a drug carrier system. In the present work, polymeric nanoparticles with different morphologies were prepared by the controlled self-assembly of amphiphilic block copolymers. The nanoparticles were subsequently characterized and their interactions with human cells and serum proteins investigated. A cytotoxicity study with spherical and cylindrical micelles as well as vesicular structures was carried out and showed a dependency of cytotoxic effects on the geometry and size of the nanoparticles. The agglomeration behavior of various polymeric nanoparticles in the presence of serum proteins was also studied. Highly uniform polymeric vesicles were continuously manufactured in a micromixer based device and in situ loading with different components was performed. In this way, dual loaded vesicles with the anticancer drug camptothecin and a high amount of hydrophobic iron oxide nanoparticles were produced. When tested in vitro, these drug-loaded vesicles showed an increased cytotoxic activity against the cancer cell line PC-3 when compared to the free drug. Specific cellular uptake in PC-3 cancer cells was demonstrated with flow cytometry and confocal laser scanning microscopy after functionalization with a cancer cell specific targeting peptide and an additional fluorescent label. Magnetic characterization of the iron oxide-loaded vesicles also confirmed the potential

  19. Twin studies advance the understanding of gene-environment interplay in human nutrigenomics.

    Science.gov (United States)

    Pallister, Tess; Spector, Tim D; Menni, Cristina

    2014-12-01

    Investigations into the genetic architecture of diet-disease relationships are particularly relevant today with the global epidemic of obesity and chronic disease. Twin studies have demonstrated that genetic makeup plays a significant role in a multitude of dietary phenotypes such as energy and macronutrient intakes, dietary patterns, and specific food group intakes. Besides estimating heritability of dietary assessment, twins provide a naturally unique, case-control experiment. Due to their shared upbringing, matched genes and sex (in the case of monozygotic (MZ) twin pairs), and age, twins provide many advantages over classic epidemiological approaches. Future genetic epidemiological studies could benefit from the twin approach particularly where defining what is 'normal' is problematic due to the high inter-individual variability underlying metabolism. Here, we discuss the use of twins to generate heritability estimates of food intake phenotypes. We then highlight the value of discordant MZ pairs to further nutrition research through discovery and validation of biomarkers of intake and health status in collaboration with cutting-edge omics technologies.

  20. Distributed Temperature Sensing - a Useful Tool for Investigation of Surface Water - Groundwater Interaction

    Science.gov (United States)

    Vogt, T.; Hahn-Woernle, L.; Sunarjo, B.; Thum, T.; Schneider, P.; Schirmer, M.; Cirpka, O. A.

    2009-04-01

    In recent years, the transition zone between surface water bodies and groundwater, known as the hyporheic zone, has been identified as crucial for the ecological status of the open-water body and the quality of groundwater. The hyporheic exchange processes vary both in time and space. For the assessment of water quality of both water bodies reliable models and measurements of the exchange rates and their variability are needed. A wide range of methods and technologies exist to estimate water fluxes between surface water and groundwater. Due to recent developments in sensor techniques and data logging work on heat as a tracer in hydrological systems advances, especially with focus on surface water - groundwater interactions. Here, we evaluate the use of Distributed Temperature Sensing (DTS) for the qualitative and quantitative investigation of groundwater discharge into and groundwater recharge from a river. DTS is based on the temperature dependence of Raman scattering. Light from a laser pulse is scattered along an optical fiber of up to several km length, which is the sensor of the DTS system. By sampling the the back-scattered light with high temporal resolution, the temperature along the fiber can be measured with high accuracy (0.1 K) and high spatial resolution (1 m). We used DTS at a test side at River Thur in North-East Switzerland. Here, the river is loosing and the aquifer is drained by two side-channels, enabling us to test DTS for both, groundwater recharge from the river and groundwater discharge into the side-channels. For estimation of seepage rates, we measured highly resolved vertical temperature profiles in the river bed. For this application, we wrapped an optical fiber around a piezometer tube and measured the temperature distribution along the fiber. Due to the wrapping, we obtained a vertical resolution of approximately 5 mm. We analyzed the temperature time series by means of Dynamic Harmonic Regression as presented by Keery et al. (2007

  1. Investigating multiple dysregulated pathways in rheumatoid arthritis based on pathway interaction network.

    Science.gov (United States)

    Song, Xian-Dong; Song, Xian-Xu; Liu, Gui-Bo; Ren, Chun-Hui; Sun, Yuan-Bo; Liu, Ke-Xin; Liu, Bo; Liang, Shuang; Zhu, Zhu

    2018-03-01

    The traditional methods of identifying biomarkers in rheumatoid arthritis (RA) have focussed on the differentially expressed pathways or individual pathways, which however, neglect the interactions between pathways. To better understand the pathogenesis of RA, we aimed to identify dysregulated pathway sets using a pathway interaction network (PIN), which considered interactions among pathways. Firstly, RA-related gene expression profile data, protein-protein interactions (PPI) data and pathway data were taken up from the corresponding databases. Secondly, principal component analysis method was used to calculate the pathway activity of each of the pathway, and then a seed pathway was identified using data gleaned from the pathway activity. A PIN was then constructed based on the gene expression profile, pathway data, and PPI information. Finally, the dysregulated pathways were extracted from the PIN based on the seed pathway using the method of support vector machines and an area under the curve (AUC) index. The PIN comprised of a total of 854 pathways and 1064 pathway interactions. The greatest change in the activity score between RA and control samples was observed in the pathway of epigenetic regulation of gene expression, which was extracted and regarded as the seed pathway. Starting with this seed pathway, one maximum pathway set containing 10 dysregulated pathways was extracted from the PIN, having an AUC of 0.8249, and the result indicated that this pathway set could distinguish RA from the controls. These 10 dysregulated pathways might be potential biomarkers for RA diagnosis and treatment in the future.

  2. Investigation on molecular interactions of antibiotics in alcohols using volumetric and acoustic studies at different temperatures

    International Nuclear Information System (INIS)

    Naseem, Bushra; Iftikhar, Madeeha

    2017-01-01

    Highlights: • Antibiotics in different alcohols are used to study their interactions in solutions. • Density and sound velocity for antibiotic solutions are measured at different temperatures. • Apparent molar volume and isentropic compressibility are used to calculate partial molar quantities. • Acoustical parameters are calculated and discussed in terms of solute–solute and solute–solvent interactions. - Abstract: The density and sound velocity for pure alcohols (methanol, ethanol, iso-propanol and n-butanol) and molal solutions of nitroimidazoles (metronidazole (MNZ) and dimetridazole (DMZ) have been measured at different temperatures (293.15–313.15 K). Different volumetric and acoustical parameters like apparent molar volume (V ϕ ), partial molar volume (VЛљ ϕ ), apparent molar isentropic compressibility (K ϕ ), partial molar isentropic compressibility (KЛљ ϕ ), hydration number (n H ), acoustic impedance (Z) and intermolecular free length (L f ) of antibiotic solutions were calculated from the experimental values of density and sound velocity. The derived values have been used to explore the solute–solute and solute–solvent interactions. The V ϕ values are positive and K ϕ values are negative in both antibiotics, indicative of strong solute–solvent interactions and closely packed structure of antibiotics in alcohols. The decreasing trend of L f with increasing antibiotic concentration shows the presence of strong intermolecular interactions in solutions.

  3. Additivity vs Synergism: Investigation of the Additive Interaction of Cinnamon Bark Oil and Meropenem in Combinatory Therapy.

    Science.gov (United States)

    Yang, Shun-Kai; Yusoff, Khatijah; Mai, Chun-Wai; Lim, Wei-Meng; Yap, Wai-Sum; Lim, Swee-Hua Erin; Lai, Kok-Song

    2017-11-04

    Combinatory therapies have been commonly applied in the clinical setting to tackle multi-drug resistant bacterial infections and these have frequently proven to be effective. Specifically, combinatory therapies resulting in synergistic interactions between antibiotics and adjuvant have been the main focus due to their effectiveness, sidelining the effects of additivity, which also lowers the minimal effective dosage of either antimicrobial agent. Thus, this study was undertaken to look at the effects of additivity between essential oils and antibiotic, via the use of cinnamon bark essential oil (CBO) and meropenem as a model for additivity. Comparisons between synergistic and additive interaction of CBO were performed in terms of the ability of CBO to disrupt bacterial membrane, via zeta potential measurement, outer membrane permeability assay and scanning electron microscopy. It has been found that the additivity interaction between CBO and meropenem showed similar membrane disruption ability when compared to those synergistic combinations which was previously reported. Hence, results based on our studies strongly suggest that additive interaction acts on a par with synergistic interaction. Therefore, further investigation in additive interaction between antibiotics and adjuvant should be performed for a more in depth understanding of the mechanism and the impacts of such interaction.

  4. Additivity vs Synergism: Investigation of the Additive Interaction of Cinnamon Bark Oil and Meropenem in Combinatory Therapy

    Directory of Open Access Journals (Sweden)

    Shun-Kai Yang

    2017-11-01

    Full Text Available Combinatory therapies have been commonly applied in the clinical setting to tackle multi-drug resistant bacterial infections and these have frequently proven to be effective. Specifically, combinatory therapies resulting in synergistic interactions between antibiotics and adjuvant have been the main focus due to their effectiveness, sidelining the effects of additivity, which also lowers the minimal effective dosage of either antimicrobial agent. Thus, this study was undertaken to look at the effects of additivity between essential oils and antibiotic, via the use of cinnamon bark essential oil (CBO and meropenem as a model for additivity. Comparisons between synergistic and additive interaction of CBO were performed in terms of the ability of CBO to disrupt bacterial membrane, via zeta potential measurement, outer membrane permeability assay and scanning electron microscopy. It has been found that the additivity interaction between CBO and meropenem showed similar membrane disruption ability when compared to those synergistic combinations which was previously reported. Hence, results based on our studies strongly suggest that additive interaction acts on a par with synergistic interaction. Therefore, further investigation in additive interaction between antibiotics and adjuvant should be performed for a more in depth understanding of the mechanism and the impacts of such interaction.

  5. Structural study and investigation of NMR tensors in interaction of dopamine with Adenine and guanine

    Directory of Open Access Journals (Sweden)

    Lingjia Xu

    2007-04-01

    Full Text Available The interaction of dopamine with adenine and guanine were studied at the Hartree-Fock level theory. The structural and vibrational properties of dopamine-4-N7GUA and dopamine-4-N3ADE were studied at level of HF/6-31G*. Interaction energies (ΔE were calculated to be -11.49 and -11.92 kcal/mol, respectively. Some of bond lengths, angels and tortions are compared. NBO studies were performed to the second-order and perturbative estimates of donor-acceptor interaction have been done. The procedures of gauge-invariant atomic orbital (GIAO and continuous-set-of-gauge-transformation (CSGT were employed to calculate isotropic shielding, chemical shifts anisotropy and chemical shifts anisotropy asymmetry and effective anisotropy using 6-31G* basis set. These calculations yielded molecular geometries in good agreement with available experimental data.

  6. Fundamental investigation on interaction forces in bubble swarms and its application to the design of centrifugal separators

    International Nuclear Information System (INIS)

    Wisman, R.

    1979-01-01

    The present investigation deals with two aspects of gas-liquid flows, viz. interaction forces between the phases in bubble swarms and numerical description of rotating gas-liquid flows. The insight obtained was applied to the development of axial gas-liquid cyclones, as used i.a. as primary separators in nuclear boiling water reactors. (Auth.)

  7. Investigating the Interaction of Graphic Organizers and Seductive Details: Can a Graphic Organizer Mitigate the Seductive-Details Effect?

    Science.gov (United States)

    Rowland-Bryant, Emily; Skinner, Christopher H.; Skinner, Amy L.; Saudargas, Richard; Robinson, Daniel H.; Kirk, Emily R.

    2009-01-01

    The interaction between seductive details (SD) and a graphic organizer (GO) was investigated. Undergraduate students (n = 207) read a target-material passage about Freud's psychosexual stages. Depending on condition, the participants also read a biographical paragraph (SD-only), viewed a graphic organizer that linked the seductive details to the…

  8. DFT investigation of the interaction of gold nanoclusters with poly(amidoamine) PAMAM G0 dendrimer

    Science.gov (United States)

    Camarada, M. B.

    2016-06-01

    The interaction between PAMAM G0 and gold nanoclusters Aun (n = 2, 4, 6, and 8) was studied theoretically at DFT level. Different coordination sites were explored, including internal and superficial coordination. All stable complexes exhibited external interaction with the amine or carbonyl site, while the core site coordination was not favored. The more stable binding of Aun was registered with the terminal amine group, while the binding at the amide site was relatively weaker. The vertical first ionization potential, electron affinity, Fermi level, and the HOMO-LUMO gap of PAMAM and Aun-PAMAM G0 complexes were also analyzed.

  9. Investigating Cross-Device Interaction between a Handheld Device and a Large Display

    DEFF Research Database (Denmark)

    Paay, Jeni; Raptis, Dimitrios; Kjeldskov, Jesper

    2017-01-01

    and mid-air gestures, pinching, swiping, swinging and flicking. We look specifically at their relative efficiency, effectiveness and accuracy in bi-directional interaction between a smartphone and large display in a point-click context. We report findings from two user studies, which show that swiping...... is both most effective, fastest and most accurate, closely followed by swinging. What these two approaches have in common is the ability to keep the pointer steady on the large display, unaffected by concurrent gestures or body movements used to complete the interaction, suggesting...

  10. Site investigation SFR. Water-rock interaction and mixing modelling in the SFR

    Energy Technology Data Exchange (ETDEWEB)

    Gimeno, Maria J.; Auque, Luis F.; Gomez, Javier B.; Acero, Patricia (University of Zaragoza (Spain))

    2011-10-15

    During 2008, the Swedish Nuclear Fuel and Waste Management Company (SKB) initiated an investigation programme for a future expansion of the final repository for low and medium level radioactive operational waste, SFR, located about 150 km north of Stockholm. The purpose of the investigations was to define and characterise a bedrock volume large enough to allow further storage of operational waste from existing Swedish nuclear power plants and future waste from the decommissioning and dismantling of nuclear power plant reactors (SKB 2008). Of several alternatives, a selected location was investigated southwest of the present SFR tunnel system. As part of the SFR Site Descriptive Model, the objective of the hydrogeochemical site description is to describe the chemistry, origin and distribution of groundwaters in the bedrock and the hydrogeochemical processes involved in their evolution. Hydrogeochemical information (salinity distribution, groundwater residence time, palaeohydrogeochemical input, etc.) are also of importance to help constrain the hydrogeological descriptive model. The hydrogeochemical modelling work has been performed in three steps, resulting in three model versions (0.1, 0.2 and 1.0). In versions 0.1 and 0.2, explorative analyses using traditional geochemical approaches (trend plots, x-y scatter plots, 3D visualisations, etc.) were performed to describe the data and to provide an early insight and understanding of the site. The final hydrogeochemical site description version 1.0 (Nilsson et al. 2011) includes data from the previous versions, as well as subsequent complementary data from the SFR extension project, and all these data are further evaluated using additional modelling approaches and techniques. In this context, the present report gives a more detailed analysis of the available data for some hydrogeochemical systems and a detailed description of the results of the geochemical and statistical modelling. One of the main aims is to establish

  11. Site investigation SFR. Water-rock interaction and mixing modelling in the SFR

    International Nuclear Information System (INIS)

    Gimeno, Maria J.; Auque, Luis F.; Gomez, Javier B.; Acero, Patricia

    2011-10-01

    During 2008, the Swedish Nuclear Fuel and Waste Management Company (SKB) initiated an investigation programme for a future expansion of the final repository for low and medium level radioactive operational waste, SFR, located about 150 km north of Stockholm. The purpose of the investigations was to define and characterise a bedrock volume large enough to allow further storage of operational waste from existing Swedish nuclear power plants and future waste from the decommissioning and dismantling of nuclear power plant reactors (SKB 2008). Of several alternatives, a selected location was investigated southwest of the present SFR tunnel system. As part of the SFR Site Descriptive Model, the objective of the hydrogeochemical site description is to describe the chemistry, origin and distribution of groundwaters in the bedrock and the hydrogeochemical processes involved in their evolution. Hydrogeochemical information (salinity distribution, groundwater residence time, palaeohydrogeochemical input, etc.) are also of importance to help constrain the hydrogeological descriptive model. The hydrogeochemical modelling work has been performed in three steps, resulting in three model versions (0.1, 0.2 and 1.0). In versions 0.1 and 0.2, explorative analyses using traditional geochemical approaches (trend plots, x-y scatter plots, 3D visualisations, etc.) were performed to describe the data and to provide an early insight and understanding of the site. The final hydrogeochemical site description version 1.0 (Nilsson et al. 2011) includes data from the previous versions, as well as subsequent complementary data from the SFR extension project, and all these data are further evaluated using additional modelling approaches and techniques. In this context, the present report gives a more detailed analysis of the available data for some hydrogeochemical systems and a detailed description of the results of the geochemical and statistical modelling. One of the main aims is to establish

  12. Investigating Syntactical and Lexical Complexity in Gendered and Same-Sex Interactions

    Science.gov (United States)

    Long, Robert W., III.

    2018-01-01

    For many sociolinguists, the issue of shyness and hesitation phenomenon has been problematic for Japanese L1 and L2 speakers, particularly in gendered interactions. Over the past decade, more Japanese are shunning conversations, relationships, and isolating themselves, which is accelerating the demographic crisis in Japan. Thus, this paper focuses…

  13. Investigating the Added Value of Interactivity and Serious Gaming for Educational TV

    Science.gov (United States)

    Bellotti, F.; Berta, R.; De Gloria, A.; Ozolina, A.

    2011-01-01

    TV is a medium with high penetration rates and has been suited to deliver informal education in several aspects since years. Thus, interactive TV may play a significant role in the current Life-Long Learning challenges, provided that meaningful applications are implemented. In this research work, we have explored the added value of interactivity…

  14. An Investigation of Pre-Service English Language Teacher Attitudes towards Varieties of English in Interaction

    Science.gov (United States)

    Litzenberg, Jason

    2013-01-01

    English has become the default language of global communication, and users around the world are adapting the traditional standards of grammar and interaction. It is imperative that teachers of English keep pace with these changing conceptualizations of the language as well as the changing expectations of its users so that they can best prepare…

  15. Investigating the relationship among transformational leadership, interpersonal interaction and mentoring functions.

    Science.gov (United States)

    Huang, Ching-Yuan; Weng, Rhay-Hung; Chen, Yi-Ting

    2016-08-01

    This study aims to ascertain the relationship between transformational leadership, interpersonal interaction and mentoring functions among new staff nurses. Mentoring functions could improve the job performance of new nurses, provide them with support and thus reduce their turnover rate. A cross-sectional study was employed. A questionnaire survey was carried out to collect data among a sample of new nurses from three hospitals in Taiwan. After gathering a total of 306 valid surveys, multiple regression analysis was applied to test the hypothesis. Inspirational motivation, idealised influence and individualised consideration had positive correlations with the overall mentoring function, but intellectual stimulation showed a positive association only with career development function. Perceived similarity and interaction frequency also had positive correlations with mentoring functions. When the shift overlap rate exceeded 80%, mentoring function showed a negative result. The transformational leadership of mentors would improve the mentoring functions among new staff nurses. Perceived similarity and interaction frequency between mentees and mentors also had positive correlations with mentoring functions. It is crucial for hospitals to redesign their leadership training and motivation programmes to enhance the transformational leadership of mentors. Furthermore, nursing managers should promote interaction between new staff nurses and their mentors; however, the shift overlap rate should not be too high. © 2016 John Wiley & Sons Ltd.

  16. Reading Intervention Using Interactive Metronome in Children with Language and Reading Impairment: A Preliminary Investigation

    Science.gov (United States)

    Ritter, Michaela; Colson, Karen A.; Park, Jungjun

    2013-01-01

    This exploratory study examined the effects of Interactive Metronome (IM) when integrated with a traditional language and reading intervention on reading achievement. Forty-nine school-age children with language and reading impairments were assigned randomly to either an experimental group who received the IM treatment or to a control group who…

  17. A Spectroscopic and Electrochemical Investigation of Interactions of Anticancer Uracil Derivatives with Cationic and Anionic Surfactants

    International Nuclear Information System (INIS)

    Zafar, F.; Shah, A.; Ahmad, Z.; Siddiq, M.; Ali, S.; Asad Muhammad Khan, A. M.; Rana, U. A.

    2015-01-01

    Interactions of 5-fluorouracil (5-FU), a commercially available anti-cancer drug and two other possibly anti-cancer actives, 2-thiouracil (2-TU) and 2,4-dithiouracil (DTU), with anionic sodium dodecyl sulphate (SDS) and cationic cetlytrimethyl ammonium bromide (CTAB) surfactants were studied using cyclic voltammetry and UV-Visible spectroscopic techniques. The results from both techniques asserted the formation of complex between the drugs and surfactants. In the pre-micellar concentrations, the binding was mainly due to the interactions between the surfactants monomers (electrostatic) and the drug molecules, while in the post-micellar region, drug was encapsulated within the micelle due to electrostatic as well as hydrophobic interactions. The UV-Visible spectroscopic data of the interaction between 5-fluorouracil and the surfactants exhibited an isobestic point which indicated the presence of equilibrium species in bulk and the micellar phase. Binding constant, partition coefficient between bulk and miceller phase, and the number of drug molecules incorporated per micelle were calculated. (author)

  18. The investigation of the interaction between edaravone and bovine serum albumin by spectroscopic approaches

    International Nuclear Information System (INIS)

    Yu Xianyong; Yang Ying; Liu Ronghua; Huang Haowen; Chen Jian; Ji Danhong; Li Xiaofang; Yang Fengxian; Yi Pinggui

    2011-01-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between edaravone (EDA) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results show that the fluorescence quenching mechanism between EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites, and the corresponding thermodynamic parameters (ΔG, ΔH, and ΔS) of the interaction system were calculated at different temperatures. According to Foerster non-radiation energy transfer theory, the binding distance between EDA and BSA was calculated to be 3.10 nm. The effect of EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effects of some common metal ions Mg 2+ , Ca 2+ , Cu 2+ , and Ni 2+ on the binding constant between EDA and BSA were examined. - Highlights: → We explored the interaction of BSA and EDA using spectroscopic methods. → The fluorescence quenching mechanism is combined quenching. → Hydrophobic interaction force plays a major role in stabilizing the complex. → The binding constants, binding sites, and thermodynamic parameters were calculated. → EDA affects the conformation of tryptophan residue's microregion.

  19. The investigation of the interaction between edaravone and bovine serum albumin by spectroscopic approaches

    Energy Technology Data Exchange (ETDEWEB)

    Xianyong, Yu; Ying, Yang; Ronghua, Liu; Haowen, Huang; Jian, Chen; Danhong, Ji [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Li Xiaofang, E-mail: fine_chem@163.co [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Fengxian, Yang [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Yi Pinggui, E-mail: pgyi@hnust.c [Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education, Hunan Province College Key Laboratory of QSAR/QSPR, School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China)

    2011-07-15

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between edaravone (EDA) and bovine serum albumin (BSA) under imitated physiological condition. The experimental results show that the fluorescence quenching mechanism between EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites, and the corresponding thermodynamic parameters ({Delta}G, {Delta}H, and {Delta}S) of the interaction system were calculated at different temperatures. According to Foerster non-radiation energy transfer theory, the binding distance between EDA and BSA was calculated to be 3.10 nm. The effect of EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy. In addition, the effects of some common metal ions Mg{sup 2+}, Ca{sup 2+}, Cu{sup 2+}, and Ni{sup 2+} on the binding constant between EDA and BSA were examined. - Highlights: {yields} We explored the interaction of BSA and EDA using spectroscopic methods. {yields} The fluorescence quenching mechanism is combined quenching. {yields} Hydrophobic interaction force plays a major role in stabilizing the complex. {yields} The binding constants, binding sites, and thermodynamic parameters were calculated. {yields} EDA affects the conformation of tryptophan residue's microregion.

  20. Explaining Student Interaction and Satisfaction: An Empirical Investigation of Delivery Mode Influence

    Science.gov (United States)

    Johnson, Zachary S.; Cascio, Robert; Massiah, Carolyn A.

    2014-01-01

    How interpersonal interactions within a course affect student satisfaction differently between face-to-face and online modes is an important research question to answer with confidence. Using students from a marketing course delivered face-to-face and online concurrently, our first study demonstrates that student-to-professor and…

  1. Investigation of the mechanism of interaction of Lithium 6 ions on Beryllium 9

    International Nuclear Information System (INIS)

    Coste, Mireille

    1962-01-01

    The objective of this research on the interaction of Lithium 6 and Beryllium 9 ions is to obtain new indications on the mode of interaction of these heavy ions, and on the configuration of target nuclei and projectile nuclei. In a first part, the author presents and describes the experimental conditions which comprise a Van de Graaff accelerator, a source, a stripper, and a target. He reports the study of α particles emitted by the reaction between the Lithium and Beryllium ions: description of the experimental installation (irradiation chamber and method), presentation and interpretation of experimental results. In the next part, he reports the study of Lithium 7 and Beryllium 10 nuclides emitted by disintegration of Beryllium 11: description of experimental conditions, variations of cross sections, variation of the cross section rate, and interpretation. The author then addresses the study of the intervention of the mode of interaction by 15 N compound nucleus in the reactions between lithium and beryllium ions: study of intensities of the different spectrum lines, measurement of the Doppler effect produced of the 479 keV line, interpretation of results. In conclusion, the author analyses the mechanism of interaction between lithium and beryllium ions, and discusses different theories: the Newns and Glendenning theories, and the Leigh theory

  2. Microfluidic biofunctionalisation protocols to form multi-valent interactions for cell rolling and phenotype modification investigations

    KAUST Repository

    Perozziello, Gerardo; Simone, Giuseppina; Malara, Natalia Maria; La Rocca, Rosanna; Tallerico, Rossana; Catalano, Rossella; Pardeo, Francesca; Candeloro, Patrizio; Cuda, Giovanni; Carbone, Ennio; Di Fabrizio, Enzo M.

    2013-01-01

    for cellomic studies. Based on this principle, we exploit the streptavidin-biotin interaction to couple antibodies to the biofunctionalised microfluidic environment within 5 h using 200 μL of reagents and biomolecules. We selected the antibodies able to form

  3. Numerical investigation into strong axis bending shear interaction in rolled I-shaped steel sections

    NARCIS (Netherlands)

    Dekker, R.W.A.; Snijder, B.H.; Maljaars, J.

    2016-01-01

    Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling soft-ware is presented. The numerical

  4. Numerical investigation into strong axis bending-shear interaction in rolled I-shaped steel sections

    NARCIS (Netherlands)

    Dekker, R.W.A.; Snijder, H.H.; Maljaars, J.; Dubina, Dan; Ungureanu, Viorel

    2016-01-01

    Clause 6.2.8 of EN 1993-1-1 covers the design rules on bending-shear resistance, taking presence of shear into account by a reduced yield stress for the shear area. Numerical research on bending-shear interaction by means of the Abaqus Finite Element modelling software is presented. The numerical

  5. Ellipsometry and LIMM investigations of the interaction between PZT thin films and platinum electrodes and air

    Czech Academy of Sciences Publication Activity Database

    Deineka, Alexander; Glinchuk, M. D.; Jastrabík, Lubomír; Suchaneck, G.; Sandner, T.; Gerlach, G.

    2001-01-01

    Roč. 254, - (2001), s. 205-211 ISSN 0015-0193 R&D Projects: GA ČR GA202/00/1425 Institutional research plan: CEZ:AV0Z1010914 Keywords : ferroelecric film * depth profile * interface interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.471, year: 2001

  6. Affinity Capillary Electrophoresis – A Powerful Tool to Investigate Biomolecular Interactions

    Czech Academy of Sciences Publication Activity Database

    Kašička, Václav

    2017-01-01

    Roč. 30, č. 5 (2017), s. 248 ISSN 1471-6577 Institutional support: RVO:61388963 Keywords : capillary affinity electrophoresis * biomolecular interactions * binding constants Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 0.663, year: 2016

  7. Investigation of wake interaction using full-scale lidar measurements and large eddy simulation

    DEFF Research Database (Denmark)

    Machefaux, Ewan; Larsen, Gunner Chr.; Troldborg, Niels

    2016-01-01

    dynamics flow solver, using large eddy simulation and fully turbulent inflow. The rotors are modelled using the actuator disc technique. A mutual validation of the computational fluid dynamics model with the measurements is conducted for a selected dataset, where wake interaction occurs. This validation...

  8. Investigation of interaction studies of cefpirome with ACE-inhibitors in various buffers

    Science.gov (United States)

    Nawaz, Muhammad; Arayne, Muhammad Saeed; Sultana, Najma; Abbas, Hira Fatima

    2015-02-01

    This work describes a RP-HPLC method for the determination and interaction studies of cefpirome with ACE-inhibitors (captopril, enalapril and lisinopril) in various buffers. The separation and interaction of cefpirome with ACE-inhibitors was achieved on a Purospher Star, C18 (5 μm, 250 × 4.6 mm) column. Mobile phase consisted of methanol: water (80:20, v/v, pH 3.3); however, for the separation of lisinopril, it was modified to methanol-water (40:60, v/v, pH 3.3) and pumped at a flow rate of 1 mL min-1. In all cases, UV detection was performed at 225 nm. Interactions were carried out in physiological pH i.e., pH 1 (simulated gastric juice), 4 (simulated full stomach), 7.4 (blood pH) and 9 (simulated GI), drug contents were analyzed by reverse phase high performance liquid chromatography. Method was found linear in the concentration range of 1.0-50.0 μg mL-1 with correlation coefficient (r2) of 0.999. Precision (RSD%) was less than 2.0%, indicating good precision of the method and accuracy was 98.0-100.0%. Furthermore, cefpirome-ACE-inhibitors' complexes were also synthesized and results were elucidated on the basis of FT-IR, and 1H NMR. The interaction results show that these interactions are pH dependent and for the co-administration of cefpirome and ACE-inhibitors, a proper interval should be given.

  9. Colloidal diatomite, radionickel, and humic substance interaction: a combined batch, XPS, and EXAFS investigation.

    Science.gov (United States)

    Sheng, Guodong; Shen, Runpu; Dong, Huaping; Li, Yimin

    2013-06-01

    This work determined the influence of humic acid (HA) and fulvic acid (FA) on the interaction mechanism and microstructure of Ni(II) onto diatomite by using batch experiments, X-ray photoelectron spectroscopy (XPS), and extended X-ray absorption fine structure (EXAFS) methods. Macroscopic and spectroscopic experiments have been combined to see the evolution of the interaction mechanism and microstructure of Ni(II) in the presence of HA/FA as compared with that in the absence of HA/FA. The results indicated that the interaction of Ni(II) with diatomite presents the expected solution pH edge at 7.0, which is modified by addition of HA/FA. In the presence of HA/FA, the interaction of Ni(II) with diatomite increased below solution pH 7.0, while Ni(II) interaction decreased above solution pH 7.0. XPS analysis suggested that the enrichment of Ni(II) onto diatomite may be due to the formation of (≡SO)2Ni. EXAFS results showed that binary surface complexes and ternary surface complexes of Ni(II) can be simultaneously formed in the presence of HA/FA, whereas only binary surface complexes of Ni(II) are formed in the absence of HA/FA, which contribute to the enhanced Ni(II) uptake at low pH values. The results observed in this work are important for the evaluation of Ni(II) and related radionuclide physicochemical behavior in the natural soil and water environment.

  10. Recursion organization of interactive experiment control systems in distributed multi-level automated systems for scientific investigations

    International Nuclear Information System (INIS)

    Putilov, V.A.

    1985-01-01

    Problems of organization of multilevel distributed systems for complex investigations of different objects, phenomena and processes are discussed. Priori uncertainty of organization procedures of these investigations assumes compulsory presence of interactive means of communication of an investigator with the system at all the levels of solving complex problems. Recurrent models which assume detailed representation of the solved problem using decomposition tree of research purposes should be used as formal apparatus when developing the considered systems. Recurrent derivation of an algorithm of the problem solution is exercised using the problem-oriented LEADER language

  11. The Influence of Major Life Events on Economic Attitudes in a World of Gene-Environment Interplay.

    Science.gov (United States)

    Hatemi, Peter K

    2013-10-01

    The role of "genes" on political attitudes has gained attention across disciplines. However, person-specific experiences have yet to be incorporated into models that consider genetic influences. Relying on a gene-environment interplay approach, this study explicates how life-events, such as losing one's job or suffering a financial loss, influence economic policy attitudes. The results indicate genetic and environmental variance on support for unions, immigration, capitalism, socialism and property tax is moderated by financial risks. Changes in the magnitude of genetic influences, however, are temporary. After two years, the phenotypic effects of the life events remain on most attitudes, but changes in the sources of individual differences do not. Univariate twin models that estimate the independent contributions of genes and environment on the variation of attitudes appear to provide robust baseline indicators of sources of individual differences. These estimates, however, are not event or day specific. In this way, genetic influences add stability, while environment cues change, and this process is continually updated.

  12. Sex-specific predictors of hearing-aid use in older persons: The age, gene/environment susceptibility - Reykjavik study

    Science.gov (United States)

    Fisher, Diana E.; Li, Chuan-Ming; Hoffman, Howard J.; Chiu, May S.; Themann, Christa L.; Petersen, Hannes; Jonsson, Palmi V.; Jonsson, Helgi; Jonasson, Fridbert; Sverrisdottir, Johanna Eyrun; Launer, Lenore J.; Eiriksdottir, Gudny; Gudnason, Vilmundur; Cotch, Mary Frances

    2015-01-01

    Objective We estimate the prevalence of hearing-aid use in Iceland and identify sex-specific factors associated with use. Design Population-based cohort study. Study sample A total of 5172 age, gene/environment susceptibility - Reykjavik study (AGES-RS) participants, aged 67 to 96 years (mean age 76.5 years), who completed air-conduction and pure-tone audiometry. Results Hearing-aid use was reported by 23.0% of men and 15.9% of women in the cohort, although among participants with at least moderate hearing loss in the better ear (pure-tone average [PTA] of thresholds at 0.5, 1, 2, and 4 kHz ≥ 35 dB hearing level [HL]) it was 49.9% and did not differ by sex. Self-reported hearing loss was the strongest predictor of hearing-aid use in men [OR: 2.68 (95% CI: 1.77, 4.08)] and women [OR: 3.07 (95% CI: 1.94, 4.86)], followed by hearing loss severity based on audiometry. Having diabetes or osteoarthritis were significant positive predictors of use in men, whereas greater physical activity and unimpaired cognitive status were important in women. Conclusions Hearing-aid use was comparable in Icelandic men and women with moderate or greater hearing loss. Self-recognition of hearing loss was the factor most predictive of hearing-aid use; other influential factors differed for men and women. PMID:25816699

  13. A multispectroscopic and molecular docking investigation of the binding interaction between serum albumins and acid orange dye

    Science.gov (United States)

    Naveenraj, Selvaraj; Solomon, Rajadurai Vijay; Mangalaraja, Ramalinga Viswanathan; Venuvanalingam, Ponnambalam; Asiri, Abdullah M.; Anandan, Sambandam

    2018-03-01

    The interaction of Acid Orange 10 (AO10) with bovine serum albumin (BSA) was investigated comparatively with that of human serum albumin (HSA) using multispectroscopic techniques for understanding their toxic mechanism. Further, density functional theory calculations and docking studies have been carried out to gain more insights into the nature of interactions existing between AO10 and serum albumins. The fluorescence results suggest that AO10 quenched the fluorescence of BSA through the combination of static and dynamic quenching mechanism. The same trend was followed in the interaction of AO10 with HSA. In addition to the type of quenching mechanism, the fluorescence spectroscopic results suggest that the binding occurs near the tryptophan moiety of serum albumins and the binding. AO10 has more binding affinity towards BSA than HSA. An AO10-Trp model has been created to explicitly understand the Csbnd Htbnd π interactions from Bader's quantum theory of atoms in molecules analysis which confirmed that AO10 bind more strongly with BSA than that of HSA due to the formation of three hydrogen bonds with BSA whereas it forms two hydrogen bonds in the case of HSA. These obtained results provide an in-depth understanding of the interaction of the acid azo dye AO10 with serum albumins. This interaction study provides insights into the underlying reasons for toxicity of AO10 relevant to understand its effect on bovids and humans during the blood transportation process.

  14. Investigation on molecular interaction of amino acids in aqueous disodium hydrogen phosphate solutions with reference to volumetric and compressibility measurements

    International Nuclear Information System (INIS)

    Kumar, Harsh; Singla, Meenu; Jindal, Rajeev

    2014-01-01

    Highlights: • Densities and speeds of sound of amino acids in aqueous disodium hydrogen phosphate. • Partial molar volumes and compressibility of transfer. • Positive values of transfer volume indicates interactions between ions of amino acids and TSC. • Ion–hydrophilic and hydrophilic–hydrophilic interactions are present. • Pair-wise interactions are dominant in the mixtures. -- Abstract: The interactions of amino acids glycine (Gly), L-alanine (Ala), and L-valine (Val) with disodium hydrogen phosphate (DSHP) as a function of temperature have been investigated by combination of volumetric and acoustic measurements. Densities (ρ) and speeds of sound (u) of amino acids in aqueous solutions of disodium hydrogen phosphate have been measured at T = (288.15, 293.15, 298.15, 303.15 and 308.15) K and atmospheric pressure. The apparent molar volume (V ϕ ), the partial molar volume (V ϕ 0 ) and standard partial molar volumes of transfer (ΔV ϕ 0 ) for amino acids from water to aqueous disodium hydrogen phosphate solutions have been calculated from density data. Partial molar adiabatic compressibility (κ ϕ,s ) and partial molar adiabatic compressibility of transfer (Δκ ϕ,S 0 ) have been calculated from speed of sound data. The pair (V AB , κ AB ) and triplet (V ABB , κ ABB ) interaction coefficient have been calculated from both the properties. The results have been explained based on competing patterns of interactions of co-solvents and the solute

  15. Investigation into interaction of CO/sub 2/ molecules with zeolites by infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ignat' eva, L A; Levshin, L V; Chukin, G D; Efimenko, L V; Kozlova, T I [Moskovskij Gosudarstvennyj Univ. (USSR). Kafedra Optiki

    1975-07-01

    Interaction of CO/sub 2/ molecules with zeolites, particularly with SrNaJ was studied by infrared-spectroscopy. To obtain infrared-spectra the zeolites were pressed into tablets and were calcinated at 500 deg. In the spectra the bands of chemisorbed CO/sub 2/ absorption were found in the range 1300 - 1600 cm/sup -1/. The CO/sub 2/ molecule was found to be strongly deformed due to chemisorption. In terms of electronic structure of the zeolite crystalline skeleton several types of CO/sub 2/ molecules interaction with different active zeolites were found. The position of the high-frequency band of CO/sub 2/ absorption in zeolites spectra was found to be a linear function of electrostatic field of the cations.

  16. The investigation of the interaction between NCP-EDA and bovine serum albumin by spectroscopic approaches

    Science.gov (United States)

    Yu, Xianyong; Lu, Shiyu; Yang, Ying; Li, Xiaofang; Yi, Pinggui

    2011-12-01

    The fluorescence and ultraviolet spectroscopies were explored to study the interaction between N-confused porphyrins-edaravone diad (NCP-EDA) and bovine serum albumin (BSA) under simulative physiological condition at different temperatures. The experimental results show that the fluorescence quenching mechanism between NCP-EDA and BSA is a combined quenching (dynamic and static quenching). The binding constants, binding sites and the corresponding thermodynamic parameters (Δ G, Δ H, and Δ S) of the interaction system were calculated at different temperatures. According to Förster non-radiation energy transfer theory, the binding distance between NCP-EDA and BSA was calculated to be 3.63 nm. In addition, the effect of NCP-EDA on the conformation of BSA was analyzed using synchronous fluorescence spectroscopy.

  17. Investigations of the structure and electromagnetic interactions of few-body systems

    International Nuclear Information System (INIS)

    Lehman, D.R.; Haberzettl, H.; Maximon, L.C.; Parke, W.C.; Bennhold, C.; Ito, Hiroshi; Pratt, R.K.; Najmeddine, M.; Rakei, A.

    1993-07-01

    The emphasis of the nuclear theory group has been on the structure and electromagnetic interactions of few-body nuclei. Both low- and intermediate-energy electromagnetic disintegration of these nuclei is considered, including coherent photoproduction of π mesons. When the excitation energy of the target nucleus is low, the aim is to handle the continuum part of the theoretical work numerically with no approximations, that is, by means of full three- or four-body dynamics. When structure questions are the issue, numerically accurate calculations are always carried through, limited only by the underlying two-body or three-body interactions used as input. A central goal is to carry through state-of-the-art few-body calculations that will serve as a means of determining at what point standard nuclear physics requires introduction of relativity and/or quark degrees of freedom in order to understand the phenomena in question

  18. Research Update: Density functional theory investigation of the interactions of silver nanoclusters with guanine

    Directory of Open Access Journals (Sweden)

    Brandon B. Dale

    2017-05-01

    Full Text Available Bare and guanine-complexed silver clusters Ag n z (n = 2-6; z = 0-2 are examined using density functional theory to elucidate the geometries and binding motifs that are present experimentally. Whereas the neutral systems remain planar in this size range, a 2D-3D transition occurs at Ag 5 + for the cationic system and at Ag 4 2 + for the dicationic system. Neutral silver clusters can bind with nitrogen 3 or with the pi system of the base. However, positively charged clusters interact with nitrogen 7 and the neighboring carbonyl group. Thus, the cationic silver-DNA clusters present experimentally may preferentially interact at these sites.

  19. The role of forensic death investigators interacting with the survivors of death by homicide and suicide.

    Science.gov (United States)

    Baumann, Robin; Stark, Sharon

    2015-01-01

    When sudden unexpected death occurs, an investigation ensues in an attempt to discover the cause and manner of death. Autopsies are performed when reasons for death are not obvious. They are used to provide information, confirm the cause of death, and/or reveal conditions not recognized before death (Hendricks, 2011). One important reason for performing an autopsy is to help families to understand what happened to their loved one so that they can begin the process of grieving. The way that the initial notification and investigation is handled can have a bearing on how a family's grief progresses. Forensic nurses are in a unique position to bring a holistic approach to death investigation with a focus of care that includes not only the decedent but the surviving loved ones as well (Koehler, 2008). Forensic nurse death investigators can assist families through initial stages of grief in the investigation of death.

  20. Investigating social functioning after early mild TBI: the quality of parent-child interactions.

    Science.gov (United States)

    Lalonde, Gabrielle; Bernier, Annie; Beaudoin, Cindy; Gravel, Jocelyn; Beauchamp, Miriam H

    2018-03-01

    The young brain is particularly vulnerable to injury due to inherent physiological and developmental factors, and even mild forms of traumatic brain injury (mTBI) can sometimes result in cognitive and behavioural difficulties. Despite the high prevalence of paediatric mTBI, little is known of its impact on children's social functioning. Parent-child relationships represent the centre of young children's social environments and are therefore ideal contexts for studying the potential effects of mTBI on children's social functioning. The aim of this study was to assess the quality of parent-child interactions after mTBI using observational assessment methods and parental report. The sample included 130 children (18-60 months at recruitment) divided into three groups: children with uncomplicated mTBI (n = 47), children with orthopaedic injury (OI, n = 27), and non-injured children (NI, n = 56). The quality of parent-child interactions was assessed 6 months post-injury using the Mutually Responsive Orientation (MRO) scale, an observational measure which focuses on the dyadic nature of parent-child exchanges, and the Parental Stress Index questionnaire (Parent-Child Dysfunctional Interaction (PCDI) domain). Significant differences with medium effect sizes were found between the mTBI group and the NI group on the MRO, but not between the OI group and the other two groups. PCDI scores did not differ across groups, suggesting that observational measures may be more sensitive to changes in parent-child interactions after TBI. The current findings have implications for children's post-injury social development and highlight the importance of monitoring social outcomes even after minor head injuries. © 2016 The British Psychological Society.

  1. Investigating cardiorespiratory interaction by cross-spectral analysis of event series

    Science.gov (United States)

    Schäfer, Carsten; Rosenblum, Michael G.; Pikovsky, Arkady S.; Kurths, Jürgen

    2000-02-01

    The human cardiovascular and respiratory systems interact with each other and show effects of modulation and synchronization. Here we present a cross-spectral technique that specifically considers the event-like character of the heartbeat and avoids typical restrictions of other spectral methods. Using models as well as experimental data, we demonstrate how modulation and synchronization can be distinguished. Finally, we compare the method to traditional techniques and to the analysis of instantaneous phases.

  2. Experimental and Theoretical Investigation of the Aromatic-Aromatic Interaction in Isolated Capped Dipeptides

    Czech Academy of Sciences Publication Activity Database

    Gloaguen, E.; Valdés, H.; Pagliarulo, F.; Pollet, R.; Tardivel, B.; Hobza, Pavel; Piuzzi, F.; Mons, M.

    2010-01-01

    Roč. 114, č. 9 (2010), s. 2973-2982 ISSN 1089-5639 R&D Projects: GA MŠk LC512 Institutional research plan: CEZ:AV0Z40550506 Keywords : aromatic residues interactions * Ac-Phe-Phe-NH2 dipeptides * Ac-Phe-D-Phe-NH2 dipeptides * correlated ab initio calculations Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.732, year: 2010

  3. Synchrotron X-ray Investigations of Mineral-Microbe-Metal Interactions

    International Nuclear Information System (INIS)

    Kemner, Kenneth M.; O'Loughlin, Edward J.; Kelly, Shelly D.; Boyanov, Maxim I.

    2005-01-01

    Interactions between microbes and minerals can play an important role in metal transformations (i.e. changes to an element's valence state, coordination chemistry, or both), which can ultimately affect that element's mobility. Mineralogy affects microbial metabolism and ecology in a system; microbes, in turn, can affect the system's mineralogy. Increasingly, synchrotron-based X-ray experiments are in routine use for determining an element's valence state and coordination chemistry, as well as for examining the role of microbes in metal transformations.

  4. MRIVIEW: An interactive computational tool for investigation of brain structure and function

    International Nuclear Information System (INIS)

    Ranken, D.; George, J.

    1993-01-01

    MRIVIEW is a software system which uses image processing and visualization to provide neuroscience researchers with an integrated environment for combining functional and anatomical information. Key features of the software include semi-automated segmentation of volumetric head data and an interactive coordinate reconciliation method which utilizes surface visualization. The current system is a precursor to a computational brain atlas. We describe features this atlas will incorporate, including methods under development for visualizing brain functional data obtained from several different research modalities

  5. Interactive multimodal ambulatory monitoring to investigate the association between physical activity and affect

    Directory of Open Access Journals (Sweden)

    Ulrich W. Ebner-Priemer

    2013-01-01

    Full Text Available Although there is a wealth of evidence that physical activity has positive effects on psychological health, a large proportion of people are inactive. Data regarding counts, steps, and movement patterns are limited in their ability to explain why people remain inactive. We propose that multimodal ambulatory monitoring, which combines the assessment of physical activity with the assessment of psychological variables, helps to elucidate real world physical activity. Whereas physical activity can be monitored continuously, psychological variables can only be assessed at discrete intervals, such as every hour. Moreover, the assessment of psychological variables must be linked to the activity of interest. For example, if an inactive and overweight person is physically active once a week, psychological variables should be assessed during this episode. Linking the assessment of psychological variables to episodes of an activity of interest can be achieved with interactive monitoring. The primary aim of our interactive multimodal ambulatory monitoring approach was to intentionally increase the number of e-diary assessments during active episodes.We developed and tested an interactive monitoring algorithm that continuously monitors physical activity in everyday life. When predefined thresholds are surpassed, the algorithm triggers a signal for participants to answer questions in their electronic diary.Using data from 70 participants wearing an accelerative device for 24 hours each, we found that our algorithm quadrupled the frequency of e-diary assessments during the activity episodes of interest compared to random sampling. Multimodal interactive ambulatory monitoring appears to be a promising approach to enhancing our understanding of real world physical activity and movement.

  6. An Empirical Investigation of the Effect of Interaction Justice Perception on Consumer Intentions after Complaining

    OpenAIRE

    Mahesh S. Bhandari; Michael J. Polonsky

    2014-01-01

    This study examined how apology as interaction justice impacts on consumer perceptions of service recovery attempt. Data was collected using hypothetical scenarios. Two types of service failures were proposed and the impact of recovery action on each failure type was compared. Findings include that there is direct effect of recovery action on consumer future intentions in both type of failures. Implications and direction to the future research were proposed.

  7. Interactions of helquats with chiral acidic aromatic analytes investigated by partial-filling affinity capillary electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Růžička, Martin; Koval, Dušan; Vávra, Jan; Reyes Gutierrez, Paul Eduardo; Teplý, Filip; Kašička, Václav

    2016-01-01

    Roč. 1467, Oct 7 (2016), s. 417-426 ISSN 0021-9673 R&D Projects: GA ČR(CZ) GA15-01948S; GA ČR GA13-32974S; GA ČR GA13-19213S Institutional support: RVO:61388963 Keywords : affinity capillary electrophoresis * binding constant * chiral separation * helquats * noncovalent interactions * partial filling Subject RIV: CB - Analytical Chemistry , Separation Impact factor: 3.981, year: 2016

  8. Preliminary investigation of interconnected systems interactions for the safety injection system of Indian Point-3

    International Nuclear Information System (INIS)

    Alesso, H.P.; Lappa, D.A.; Smith, C.F.; Sacks, I.J.

    1983-01-01

    The rich diversity of ideas and techniques for analyzing interconnected systems interaction has presented the NRC with the problem of identifying methods appropriate for their own review and audit. This report presents the findings of a preliminary study using the Digraph Matrix Analysis method to evaluate interconnected systems interactions for the safety injection system of Indian Point-3. The analysis effort in this study was subjected to NRC constraints regarding the use of Boolean logic, the construction of simplified plant representations or maps, and the development of heuristic measures as specified by the NRC. The map and heuristic measures were found to be an unsuccessful approach. However, from the effort to model and analyze the Indian Point-3 safety injection system, including Boolean logic in the model, singleton and doubleton cut-sets were identified. It is recommended that efforts excluding Boolean logic and utilizing the NRC heuristic measures not be pursed further and that the Digraph Matrix approach (or other comparable risk assessment technique) with Boolean logic included to conduct the audit of the Indian Point-3 systems interaction study

  9. Investigating interactions between phospholipase B-Like 2 and antibodies during Protein A chromatography.

    Science.gov (United States)

    Tran, Benjamin; Grosskopf, Vanessa; Wang, Xiangdan; Yang, Jihong; Walker, Don; Yu, Christopher; McDonald, Paul

    2016-03-18

    Purification processes for therapeutic antibodies typically exploit multiple and orthogonal chromatography steps in order to remove impurities, such as host-cell proteins. While the majority of host-cell proteins are cleared through purification processes, individual host-cell proteins such as Phospholipase B-like 2 (PLBL2) are more challenging to remove and can persist into the final purification pool even after multiple chromatography steps. With packed-bed chromatography runs using host-cell protein ELISAs and mass spectrometry analysis, we demonstrated that different therapeutic antibodies interact to varying degrees with host-cell proteins in general, and PLBL2 specifically. We then used a high-throughput Protein A chromatography method to further examine the interaction between our antibodies and PLBL2. Our results showed that the co-elution of PLBL2 during Protein A chromatography is highly dependent on the individual antibody and PLBL2 concentration in the chromatographic load. Process parameters such as antibody resin load density and pre-elution wash conditions also influence the levels of PLBL2 in the Protein A eluate. Furthermore, using surface plasmon resonance, we demonstrated that there is a preference for PLBL2 to interact with IgG4 subclass antibodies compared to IgG1 antibodies. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Earthquake simulation, actual earthquake monitoring and analytical methods for soil-structure interaction investigation

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H T [Seismic Center, Electric Power Research Institute, Palo Alto, CA (United States)

    1988-07-01

    Approaches for conducting in-situ soil-structure interaction experiments are discussed. High explosives detonated under the ground can generate strong ground motion to induce soil-structure interaction (SSI). The explosive induced data are useful in studying the dynamic characteristics of the soil-structure system associated with the inertial aspect of the SSI problem. The plane waves generated by the explosives cannot adequately address the kinematic interaction associated with actual earthquakes because of he difference in wave fields and their effects. Earthquake monitoring is ideal for obtaining SSI data that can address all aspects of the SSI problem. The only limitation is the level of excitation that can be obtained. Neither the simulated earthquake experiments nor the earthquake monitoring experiments can have exact similitude if reduced scale test structures are used. If gravity effects are small, reasonable correlations between the scaled model and the prototype can be obtained provided that input motion can be scaled appropriately. The key product of the in-situ experiments is the data base that can be used to qualify analytical methods for prototypical applications. (author)

  11. Interfacial Interaction of Titania Nanoparticles and Ligated Uranyl Species: A Relativistic DFT Investigation.

    Science.gov (United States)

    Zhao, Hong-Bo; Zheng, Ming; Schreckenbach, Georg; Pan, Qing-Jiang

    2017-03-06

    To understand interfacial behavior of actinides adsorbed onto mineral surfaces and unravel their structure-property relationship, the structures, electronic properties, and energetics of various ligated uranyl species adsorbed onto TiO 2 surface nanoparticle clusters (SNCs) were examined using relativistic density functional theory. Rutile (110) and anatase (101) titania surfaces, experimentally known to be stable, were fully optimized. For the former, models studied include clean and water-free Ti 27 O 64 H 20 (dry), partially hydrated (Ti 27 O 64 H 20 )(H 2 O) 8 (sol) and proton-saturated [(Ti 27 O 64 H 20 )(H 2 O) 8 (H) 2 ] 2+ (sat), while defect-free and defected anatase SNCs involving more than 38 TiO 2 units were considered. The aquouranyl sorption onto rutile SNCs is energetically preferred, with interaction energies of -8.54, -10.36, and -2.39 eV, respectively. Energy decomposition demonstrates that the sorption is dominated by orbital attractive interactions and modified by steric effects. Greater hydrogen-bonding involvement leads to increased orbital interactions (i.e., more negative energy) from dry to sol/sat complexes, while much larger steric interaction in the sat complex significantly reduces the sorption interaction (i.e., more positive energy). For dry SNC, adsorbates were varied from aquo to aquo-carbonato, to carbonato, to hydroxo uranyl species. Longer U-O surf /U-Ti distances and more positive sorption energies were calculated upon introducing carbonato and hydroxo ligands, indicative of weaker uranyl sorption onto the substrate. This is consistent with experimental observations that the uranyl sorption rate decreases upon raising solution pH value or adding carbon dioxide. Anatase SNCs adsorbing aquouranyl are even more exothermic, because more bonds are formed than in the case of rutile. Moreover, the anatase sorption can be tuned by surface defects as well as its Ti and O stoichiometry. All the aquouranyl-SNC complexes show similar

  12. The Reciprocal Relationship between Bipolar Disorder and Social Interaction: A Qualitative Investigation.

    Science.gov (United States)

    Owen, Rebecca; Gooding, Patricia; Dempsey, Robert; Jones, Steven

    2017-07-01

    Evidence suggests that social support can influence relapse rates, functioning and various clinical outcomes in people with bipolar disorder. Yet 'social support' is a poorly defined construct, and the mechanisms by which it affects illness course in bipolar disorder remain largely unknown. Key aims of this study were to ascertain which facets of social interaction affect mood management in bipolar disorder, and how symptoms of bipolar disorder can influence the level of support received. Semi-structured qualitative interviews were conducted with 20 individuals with bipolar disorder. Questions were designed to elicit: the effects of social interaction upon the management and course of bipolar disorder; and the impact of bipolar disorder upon social relationships. An inductive thematic analysis was used to analyse the data. Empathy and understanding from another person can make it easier to cope with bipolar disorder. Social interaction can also provide opportunities to challenge negative ruminative thoughts and prevent the onset of a major mood episode. The loss of social support, particularly through bereavement, creates a loss of control and can trigger mania or depression. Hypomanic symptoms can facilitate new social connections, whereas disinhibited and risky behaviour exhibited during mania can cause the breakdown of vital relationships. An in-depth clinical formulation of an individual's perceptions of how their illness affects and is affected by social interaction is crucial to understanding psychosocial factors which influence mood management. These results have clear application in interventions which aim to promote improved wellbeing and social functioning in bipolar disorder. Copyright © 2016 John Wiley & Sons, Ltd. The relationship between bipolar-related experiences and social interaction is complex and multi-faceted. Bipolar disorder can damage social relationships and create a loss of social control via extreme mood states, but it can also offer a

  13. Investigating CFTR and KCa3.1 Protein/Protein Interactions.

    Directory of Open Access Journals (Sweden)

    Hélène Klein

    Full Text Available In epithelia, Cl- channels play a prominent role in fluid and electrolyte transport. Of particular importance is the cAMP-dependent cystic fibrosis transmembrane conductance regulator Cl- channel (CFTR with mutations of the CFTR encoding gene causing cystic fibrosis. The bu