WorldWideScience

Sample records for strong founder effects

  1. A Test of Founder Effect Speciation Using Multiple Loci in the Auklets (Aethia spp.)

    OpenAIRE

    Walsh, H. E.; Jones, I. L.; Friesen, V. L.

    2005-01-01

    Whether speciation results more frequently from the genetic consequences of founder events or from gradual genetic divergence of large populations is a matter of debate. In this study, multiple analyses were applied to data from three loci (cytochrome b, α-enolase intron VIII, and MHC class II B) to test for founder effects associated with speciation in Aethia (Aves: Alcidae), a genus of seabirds thought to have undergone a rapid founder-induced radiation. Effective population sizes (Ne) were...

  2. The Effect of Founder Family Influence on Hedging and Speculation

    DEFF Research Database (Denmark)

    Aabo, Tom; Kuhn, Jochen; Zanotti, Giovanna

    founder family firms and other firms in relation to their management of foreign exchange rate, interest rate, and commodity price exposures. Digging deeper into a subsample of users of foreign exchange derivatives and debt denominated in foreign currency, we find that founder family firms not only tend...

  3. Y chromosome evidence for a founder effect in Ashkenazi Jews.

    Science.gov (United States)

    Nebel, Almut; Filon, Dvora; Faerman, Marina; Soodyall, Himla; Oppenheim, Ariella

    2005-03-01

    Recent genetic studies, based on Y chromosome polymorphic markers, showed that Ashkenazi Jews are more closely related to other Jewish and Middle Eastern groups than to their host populations in Europe. However, Ashkenazim have an elevated frequency of R-M17, the dominant Y chromosome haplogroup in Eastern Europeans, suggesting possible gene flow. In the present study of 495 Y chromosomes of Ashkenazim, 57 (11.5%) were found to belong to R-M17. Detailed analyses of haplotype structure, diversity and geographic distribution suggest a founder effect for this haplogroup, introduced at an early stage into the evolving Ashkenazi community in Europe. R-M17 chromosomes in Ashkenazim may represent vestiges of the mysterious Khazars.

  4. Founder effect in 20 Afrikaner kindreds with pseudoxanthoma ...

    African Journals Online (AJOL)

    It is suggested that these two groups are the founder groups of present-day PXE patients. Similar genealogical studies have been performed on kindreds with familial polyposis, familial heart block and familial hyper. cholesterolaemia, among other disorders. Due to geographical isolation, political developments and cultural ...

  5. Can a linguistic serial founder effect originating in Africa explain the worldwide phonemic cline?

    Science.gov (United States)

    Fort, Joaquim; Pérez-Losada, Joaquim

    2016-04-01

    It has been proposed that a serial founder effect could have caused the present observed pattern of global phonemic diversity. Here we present a model that simulates the human range expansion out of Africa and the subsequent spatial linguistic dynamics until today. It does not assume copying errors, Darwinian competition, reduced contrastive possibilities or any other specific linguistic mechanism. We show that the decrease of linguistic diversity with distance (from the presumed origin of the expansion) arises under three assumptions, previously introduced by other authors: (i) an accumulation rate for phonemes; (ii) small phonemic inventories for the languages spoken before the out-of-Africa dispersal; (iii) an increase in the phonemic accumulation rate with the number of speakers per unit area. Numerical simulations show that the predictions of the model agree with the observed decrease of linguistic diversity with increasing distance from the most likely origin of the out-of-Africa dispersal. Thus, the proposal that a serial founder effect could have caused the present observed pattern of global phonemic diversity is viable, if three strong assumptions are satisfied. © 2016 The Authors.

  6. Legacy of mutiny on the Bounty: founder effect and admixture on Norfolk Island.

    Science.gov (United States)

    Macgregor, Stuart; Bellis, Claire; Lea, Rod A; Cox, Hannah; Dyer, Tom; Blangero, John; Visscher, Peter M; Griffiths, Lyn R

    2010-01-01

    The population of Norfolk Island, located off the eastern coast of Australia, possesses an unusual and fascinating history. Most present-day islanders are related to a small number of the 'Bounty' mutineer founders. These founders consisted of Caucasian males and Polynesian females and led to an admixed present-day population. By examining a single large pedigree of 5742 individuals, spanning >200 years, we analyzed the influence of admixture and founder effect on various cardiovascular disease (CVD)-related traits. On account of the relative isolation of the population, on average one-third of the genomes of present-day islanders (single large pedigree individuals) is derived from 17 initial founders. The proportion of Polynesian ancestry in the present-day individuals was found to significantly influence total triglycerides, body mass index, systolic blood pressure and diastolic blood pressure. For various cholesterol traits, the influence of ancestry was less marked but overall the direction of effect for all CVD-related traits was consistent with Polynesian ancestry conferring greater CVD risk. Marker-derived homozygosity was computed and agreed with measures of inbreeding derived from pedigree information. Founder effect (inbreeding and marker-derived homozygosity) significantly influenced height. In conclusion, both founder effect and extreme admixture have substantially influenced the genetic architecture of a variety of CVD-related traits in this population.

  7. Do (Female) Founders Influence (Female) Joiners to Become Founders too?

    DEFF Research Database (Denmark)

    Rocha, Vera; Van Praag, Mirjam

    Female founders are scarce, certainly those employing personnel. Do (female) founders affect the likelihood of (female) joiners to become founders too? Recent research demonstrates that joiners are more sensitive to contextual influences than founders. Joining a startup could provide a context to...... a multiplier effect in reducing gender gaps in entrepreneurship rates.......-founder (gender) homophily affects the likelihood of female and male joiners to become founders themselves. We find a relatively large and robust positive effect among female joiners that can be attributed to the role modeling function of female founders. Female entrepreneurs hiring personnel may thus have...

  8. The impact of founder effects, gene flow, and European admixture on native American genetic diversity.

    Science.gov (United States)

    Hunley, Keith; Healy, Meghan

    2011-12-01

    Recent studies have concluded that the global pattern of neutral genetic diversity in humans reflects a series of founder effects and population movements associated with our recent expansion out of Africa. In contrast, regional studies tend to emphasize the significance of more complex patterns of colonization, gene flow, and secondary population movements in shaping patterns of diversity. Our objective in this study is to examine how founder effects, gene flow, and European admixture have molded patterns of neutral genetic diversity in the Americas. Our strategy is to test the fit of a serial founder effects process to the pattern of neutral autosomal genetic variation and to examine the contribution of gene flow and European admixture to departures from fit. The genetic data consist of 678 autosomal microsatellite loci assayed by Wang and colleagues in 530 individuals in 29 widely distributed Native American populations. We find that previous evidence for serial founder effects in the Americas may be driven in part by high levels of European admixture in northern North America, intermediate levels in Central America, and low levels in eastern South America. Geographically patterned admixture may also account for previously reported genetic differences between Andean and Amazonian groups. Though admixture has obscured the precise details of precontact evolutionary processes, we find that genetic diversity is still largely hierarchically structured and that gene flow between neighboring groups has had surprisingly little impact on macrogeographic patterns of genetic diversity in the Americas. 2011 Wiley Periodicals, Inc.

  9. HIV competition dynamics over sexual networks: first comer advantage conserves founder effects.

    Science.gov (United States)

    Ferdinandy, Bence; Mones, Enys; Vicsek, Tamás; Müller, Viktor

    2015-02-01

    Outside Africa, the global phylogeography of HIV is characterized by compartmentalized local epidemics that are typically dominated by a single subtype, which indicates strong founder effects. We hypothesized that the competition of viral strains at the epidemic level may involve an advantage of the resident strain that was the first to colonize a population. Such an effect would slow down the invasion of new strains, and thus also the diversification of the epidemic. We developed a stochastic modelling framework to simulate HIV epidemics over dynamic contact networks. We simulated epidemics in which the second strain was introduced into a population where the first strain had established a steady-state epidemic, and assessed whether, and on what time scale, the second strain was able to spread in the population. Simulations were parameterized based on empirical data; we tested scenarios with varying levels of overall prevalence. The spread of the second strain occurred on a much slower time scale compared with the initial expansion of the first strain. With strains of equal transmission efficiency, the second strain was unable to invade on a time scale relevant for the history of the HIV pandemic. To become dominant over a time scale of decades, the second strain needed considerable (>25%) advantage in transmission efficiency over the resident strain. The inhibition effect was weaker if the second strain was introduced while the first strain was still in its growth phase. We also tested how possible mechanisms of interference (inhibition of superinfection, depletion of highly connected hubs in the network, one-time acute peak of infectiousness) contribute to the inhibition effect. Our simulations confirmed a strong first comer advantage in the competition dynamics of HIV at the population level, which may explain the global phylogeography of the virus and may influence the future evolution of the pandemic.

  10. HIV competition dynamics over sexual networks: first comer advantage conserves founder effects.

    Directory of Open Access Journals (Sweden)

    Bence Ferdinandy

    2015-02-01

    Full Text Available Outside Africa, the global phylogeography of HIV is characterized by compartmentalized local epidemics that are typically dominated by a single subtype, which indicates strong founder effects. We hypothesized that the competition of viral strains at the epidemic level may involve an advantage of the resident strain that was the first to colonize a population. Such an effect would slow down the invasion of new strains, and thus also the diversification of the epidemic. We developed a stochastic modelling framework to simulate HIV epidemics over dynamic contact networks. We simulated epidemics in which the second strain was introduced into a population where the first strain had established a steady-state epidemic, and assessed whether, and on what time scale, the second strain was able to spread in the population. Simulations were parameterized based on empirical data; we tested scenarios with varying levels of overall prevalence. The spread of the second strain occurred on a much slower time scale compared with the initial expansion of the first strain. With strains of equal transmission efficiency, the second strain was unable to invade on a time scale relevant for the history of the HIV pandemic. To become dominant over a time scale of decades, the second strain needed considerable (>25% advantage in transmission efficiency over the resident strain. The inhibition effect was weaker if the second strain was introduced while the first strain was still in its growth phase. We also tested how possible mechanisms of interference (inhibition of superinfection, depletion of highly connected hubs in the network, one-time acute peak of infectiousness contribute to the inhibition effect. Our simulations confirmed a strong first comer advantage in the competition dynamics of HIV at the population level, which may explain the global phylogeography of the virus and may influence the future evolution of the pandemic.

  11. A serial founder effect model for human settlement out of Africa

    OpenAIRE

    Deshpande, Omkar; Batzoglou, Serafim; Feldman, Marcus W.; Luca Cavalli-Sforza, L.

    2008-01-01

    The increasing abundance of human genetic data has shown that the geographical patterns of worldwide genetic diversity are best explained by human expansion out of Africa. This expansion is modelled well by prolonged migration from a single origin in Africa with multiple subsequent serial founding events. We discuss a new simulation model for the serial founder effect out of Africa and compare it with results from previous studies. Unlike previous models, we distinguish colonization events fr...

  12. [High prevalence of specific language impairment in Robinson Crusoe Island. A possible founder effect].

    Science.gov (United States)

    Villanueva, Pía; de Barbieri, Zulema; Palomino, Hernán M; Palomino, Hernán

    2008-02-01

    Specific language impairment (SLI) occurs in 2% to 8% of preschool children. Major and candidate genes are probably involved. Genetic drift is a cause for the presence of high frequencies of deleterious alíeles of a specific disease and the founder effect is one of its forms. Robinson Crusoe Island has 633 inhabitants and its actual population began with 8 families that repopulated the island at the end of XIXth century. To assess the frequency of specific language impairment among children living in Robinson Crusoe Island. All 66 children aged between 3 and 9 years living in the island, were studied. Parents were interviewed and in children, non verbal intelligence, audiometric parameters, comprehension and expression of oral language were assessed. Extended genealogies were also performed. Forty children had at least one parent that was descending of founder families. Among these, 35% had SLI. Eighth five percent of SLI affected children came from the same colonizer family. The prevalence of SLI in Robinson Crusoe Island is higher than that reported in mainland Chile and abroad. This high prevalence, associated to a high frequency of consanguinity, supports the influence of genetic mechanisms in SLI transmission, based on a founder effect.

  13. Do (Female) Founders Influence (Female) Joiners to Become Founders too?

    DEFF Research Database (Denmark)

    Rocha, Vera; Van Praag, Mirjam

    to experiment provisional founder identities, especially if the founder is perceived as a role model. Role models are more likely to be influential, the more similar they are to the focal person, especially if both are minorities, as is the case for women in entrepreneurial environments. We study how joiner......-founder (gender) homophily affects the likelihood of female and male joiners to become founders themselves. We find a relatively large and robust positive effect among female joiners that can be attributed to the role modeling function of female founders. Female entrepreneurs hiring personnel may thus have...

  14. Tests of two methods for identifying founder effects in metapopulations reveal substantial type II error.

    Science.gov (United States)

    Reynolds, R Graham; Fitzpatrick, Benjamin M

    2013-03-01

    Genetic analysis has been promoted as a way to reconstruct recent historical dynamics ("historical demography") by screening for signatures of events, such as bottlenecks, that disrupt equilibrium patterns of variation. Such analyses might also identify "metapopulation" processes like extinction and recolonization or source-sink dynamics, but this potential remains largely unrealized. Here we use simulations to test the ability of two currently used strategies to distinguish between a set of interconnected subpopulations (demes) that have undergone bottlenecks or extinction and recolonization events (metapopulation dynamics) from a set of static demes. The first strategy, decomposed pairwise regression, provides a holistic test for heterogeneity among demes in their patterns of isolation-by-distance. This method suffered from a type II error rate of 59-100 %, depending on parameter conditions. The second strategy tests for deviations from mutation-drift equilibrium on a deme-by-deme basis to identify sites likely to have experienced recent bottlenecks or founder effects. Although bottleneck tests have good statistical power for single populations with recent population declines, their validity in structured populations has been called into question, and they have not been tested in a metapopulation context with immigration (or colonization) and population recovery. Our simulations of hypothetical metapopulations show that population recovery can rapidly eliminate the statistical signature of a bottleneck, and that moderate levels of gene flow can generate a false signal of recent population growth for demes in equilibrium. Although we did not cover all possible metapopulation scenarios, the performance of the tests was disappointing. Our results indicate that these methods might often fail to identify population bottlenecks and founder effects if population recovery and/or gene flow are influential demographic features of the study system.

  15. Brief communication: human cranial variation fits iterative founder effect model with African origin.

    Science.gov (United States)

    von Cramon-Taubadel, Noreen; Lycett, Stephen J

    2008-05-01

    Recent studies comparing craniometric and neutral genetic affinity matrices have concluded that, on average, human cranial variation fits a model of neutral expectation. While human craniometric and genetic data fit a model of isolation by geographic distance, it is not yet clear whether this is due to geographically mediated gene flow or human dispersal events. Recently, human genetic data have been shown to fit an iterative founder effect model of dispersal with an African origin, in line with the out-of-Africa replacement model for modern human origins, and Manica et al. (Nature 448 (2007) 346-349) have demonstrated that human craniometric data also fit this model. However, in contrast with the neutral model of cranial evolution suggested by previous studies, Manica et al. (2007) made the a priori assumption that cranial form has been subject to climatically driven natural selection and therefore correct for climate prior to conducting their analyses. Here we employ a modified theoretical and methodological approach to test whether human cranial variability fits the iterative founder effect model. In contrast with Manica et al. (2007) we employ size-adjusted craniometric variables, since climatic factors such as temperature have been shown to correlate with aspects of cranial size. Despite these differences, we obtain similar results to those of Manica et al. (2007), with up to 26% of global within-population craniometric variation being explained by geographic distance from sub-Saharan Africa. Comparative analyses using non-African origins do not yield significant results. The implications of these results are discussed in the light of the modern human origins debate. (c) 2007 Wiley-Liss, Inc.

  16. Clinal patterns of human Y chromosomal diversity in continental Italy and Greece are dominated by drift and founder effects.

    Science.gov (United States)

    Di Giacomo, F; Luca, F; Anagnou, N; Ciavarella, G; Corbo, R M; Cresta, M; Cucci, F; Di Stasi, L; Agostiano, V; Giparaki, M; Loutradis, A; Mammi', C; Michalodimitrakis, E N; Papola, F; Pedicini, G; Plata, E; Terrenato, L; Tofanelli, S; Malaspina, P; Novelletto, A

    2003-09-01

    We explored the spatial distribution of human Y chromosomal diversity on a microgeographic scale, by typing 30 population samples from closely spaced locations in Italy and Greece for 9 haplogroups and their internal microsatellite variation. We confirm a significant difference in the composition of the Y chromosomal gene pools of the two countries. However, within each country, heterogeneity is not organized along the lines of clinal variation deduced from studies on larger spatial scales. Microsatellite data indicate that local increases of haplogroup frequencies can be often explained by a limited number of founders. We conclude that local founder or drift effects are the main determinants in shaping the microgeographic Y chromosomal diversity.

  17. All that glitters is not gold - founder effects complicate associations of flu mutations to disease severity

    Directory of Open Access Journals (Sweden)

    Eisenhaber Frank

    2010-11-01

    Full Text Available Abstract Background The recent 2009 (H1N1 influenza A pandemic saw a rapid spread of the virus to essentially all parts of the world. In the course of its evolution, the virus acquired many mutations, some of which have been investigated in the context of increased severity due to high occurrences in fatal cases. For example, statements such as: "42.9% of individuals who died from laboratory-confirmed cases of the pandemic (H1N1 were infected with the hemagglutinin (HA Q310 H mutant virus." give the impression that HA-Q310 H would be highly dangerous or important, while careful consideration of all available data suggests that this is unlikely to be the case. Results We compare the mutations HA-Q310 H, PB2-K340N, HA-D239N and HA-D239G using whole genome phylogenetic trees, structural modeling in their 3 D context and complete epidemiological data from sequences to clinical outcomes. HA-Q310 H and PB2-K340N appear as isolated subtrees in the phylogenetic analysis pointing to founder effects which is consistent with their clustered temporal appearance as well as the lack of an immediate structural basis that could explain a change of phenotypes. Considering the prevailing viral genomic background, shared origin of samples (all from the city of Sao Paulo and narrow temporal window (all death case samples within 1 month, it becomes clear that HA-Q310 H was actually a generally common mutation in the region at that time which could readily explain its increased occurrence among the few analyzed fatal cases without requiring necessarily an association with severity. In further support of this, we highlight 3 mild cases with the HA-Q310 H mutation. Conclusions We argue that claims of severity of any current and future flu mutation need to be critically considered in the light of phylogenetic, structural and detailed epidemiological data to distinguish increased occurrence due to possible founder effects rather than real phenotypic changes.

  18. A serial founder effect model for human settlement out of Africa.

    Science.gov (United States)

    Deshpande, Omkar; Batzoglou, Serafim; Feldman, Marcus W; Cavalli-Sforza, L Luca

    2009-01-22

    The increasing abundance of human genetic data has shown that the geographical patterns of worldwide genetic diversity are best explained by human expansion out of Africa. This expansion is modelled well by prolonged migration from a single origin in Africa with multiple subsequent serial founding events. We discuss a new simulation model for the serial founder effect out of Africa and compare it with results from previous studies. Unlike previous models, we distinguish colonization events from the continued exchange of people between occupied territories as a result of mating. We conduct a search through parameter space to estimate the range of parameter values that best explain key statistics from published data on worldwide variation in microsatellites. The range of parameters we use is chosen to be compatible with an out-of-Africa migration at 50-60Kyr ago and archaeo-ethno-demographic information. In addition to a colonization rate of 0.09-0.18, for an acceptable fit to the published microsatellite data, incorporation into existing models of exchange between neighbouring populations is essential, but at a very low rate. A linear decay of genetic diversity with geographical distance from the origin of expansion could apply to any species, especially if it moved recently into new geographical niches.

  19. Rejection of a serial founder effects model of genetic and linguistic coevolution

    Science.gov (United States)

    Hunley, Keith; Bowern, Claire; Healy, Meghan

    2012-01-01

    Recent genetic studies attribute the negative correlation between population genetic diversity and distance from Africa to a serial founder effects (SFE) evolutionary process. A recent linguistic study concluded that a similar decay in phoneme inventories in human languages was also the product of the SFE process. However, the SFE process makes additional predictions for patterns of neutral genetic diversity, both within and between groups, that have not yet been tested on phonemic data. In this study, we describe these predictions and test them on linguistic and genetic samples. The linguistic sample consists of 725 widespread languages, which together contain 908 distinct phonemes. The genetic sample consists of 614 autosomal microsatellite loci in 100 widespread populations. All aspects of the genetic pattern are consistent with the predictions of SFE. In contrast, most of the predictions of SFE are violated for the phonemic data. We show that phoneme inventories provide information about recent contacts between languages. However, because phonemes change rapidly, they cannot provide information about more ancient evolutionary processes. PMID:22298843

  20. Founder effect uncovers a new axis in polyethylene succinate bioremediation during biostimulation.

    Science.gov (United States)

    Tribedi, Prosun; Sil, Alok K

    2013-09-01

    Biostimulation is a method of in situ bioremediation wherein native soil microbes are stimulated by nutrient supplementation. In a previous report, we showed considerable polyethylene succinate (PES) degradation by biostimulation. To gain an insight into this, this study was undertaken to investigate the different facets of the microbial population present in both soil and PES-films during biostimulation-mediated PES degradation. It was observed that addition of PES-films to both nutrient-treated and untreated soil resulted in significant reduction of soil microbial counts compared with the corresponding control. It was observed that a small microbial population containing both PES degraders and non-degraders translocated to PES surface. Over time, the population adhering to PES films changed from having both PES degraders and non-degraders to being mainly PES degraders. This newly developed microbial community on PES-films exhibited low diversity with a distinct cluster of metabolic fingerprinting and higher evenness compared with parent soil microbial population. Thus the establishment of a new community on the PES surface is an exhibition of founder effect, which subsequently resulted in the emergence of a more efficient PES-degrading population and subsequently led to considerable PES degradation. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  1. Founder effect of a prevalent phenylketonuria mutation in the Oriental population

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tao (Baylor College of Medicine, Houston, TX (United States) Chinese Academy of Medical Sciences, Beijing (China)); Okano, Yoshiyuki; Eisensmith, R.C.; Harvey, M.L.; Woo, S.L.C. (Baylor College of Medicine, Houston, TX (United States)); Lo, W.H.Y.; Yuan, Lifang (Chinese Academy of Medical Sciences, Beijing (China)); Huang, Shuzhen; Zeng, Yitao (Shanghai Children' s Hospital (China)); Furuyama, Junichi (Hyogo College of Medicine, Nishinomiya (Japan)); Oura, Toshiaki (Osaka Municipal Rehabilitation Center for the Disabled, Osaka (Japan)); Sommer, S.S. (Mayo Clinic/Foundation, Rochester, MN (United States))

    1991-03-15

    A missense mutation has been identified in the human phenylalanine hydroxylase Chinese patient with classic phenylketonuria (PKU). A G-to-C transition at the second base of codon 413 in exon 12 of the gene results in the substitution of Pro{sup 413} for Arg{sup 413} in the mutant protein. This mutation (R413P) results in negligible enzymatic activity when expressed in heterologous mammalian cells and is compatible with a classic PKU phenotype in the patient. Population genetic studies reveal that this mutation is tightly linked to restriction fragment length polymorphism haplotype 4, which is the predominant haplotype of the PAH locus in the Oriental population. It accounts for 13.8% of northern Chinese and 27% of Japanese PKU alleles, but it is rare in southern Chinese (2.2%) and is absent in the Caucasian population. The data demonstrate unambiguously that the mutation occurred after racial divergence of Orientals and Caucasians and suggest that the allele has spread throughout the Orient by a founder effect. Previous protein polymorphism studies in eastern Asia have led to the hypothesis that northern Mongoloids represented a founding population in Asia. The results are compatible with this hypothesis in that the PKU mutation might have occurred in northern Mongoloids and subsequently spread to the Chinese and Japanese populations.

  2. Founder effect of a prevalent phenylketonuria mutation in the Oriental population

    International Nuclear Information System (INIS)

    Wang, Tao; Okano, Yoshiyuki; Eisensmith, R.C.; Harvey, M.L.; Woo, S.L.C.; Lo, W.H.Y.; Yuan, Lifang; Huang, Shuzhen; Zeng, Yitao; Furuyama, Junichi; Oura, Toshiaki; Sommer, S.S.

    1991-01-01

    A missense mutation has been identified in the human phenylalanine hydroxylase Chinese patient with classic phenylketonuria (PKU). A G-to-C transition at the second base of codon 413 in exon 12 of the gene results in the substitution of Pro 413 for Arg 413 in the mutant protein. This mutation (R413P) results in negligible enzymatic activity when expressed in heterologous mammalian cells and is compatible with a classic PKU phenotype in the patient. Population genetic studies reveal that this mutation is tightly linked to restriction fragment length polymorphism haplotype 4, which is the predominant haplotype of the PAH locus in the Oriental population. It accounts for 13.8% of northern Chinese and 27% of Japanese PKU alleles, but it is rare in southern Chinese (2.2%) and is absent in the Caucasian population. The data demonstrate unambiguously that the mutation occurred after racial divergence of Orientals and Caucasians and suggest that the allele has spread throughout the Orient by a founder effect. Previous protein polymorphism studies in eastern Asia have led to the hypothesis that northern Mongoloids represented a founding population in Asia. The results are compatible with this hypothesis in that the PKU mutation might have occurred in northern Mongoloids and subsequently spread to the Chinese and Japanese populations

  3. Molecular and genealogical evidence for a founder effect in Fanconi anemia families of the Afrikaner population of South Africa

    OpenAIRE

    Tipping, A. J.; Pearson, T.; Morgan, N. V.; Gibson, R. A.; Kuyt, L. P.; Havenga, C.; Gluckman, E.; Joenje, H.; de Ravel, T.; Jansen, S.; Mathew, C. G.

    2001-01-01

    Fanconi anemia (FA) is a rare, genetically heterogeneous autosomal recessive disorder associated with progressive aplastic anemia, congenital abnormalities, and cancer. FA has a very high incidence in the Afrikaner population of South Africa, possibly due to a founder effect. Previously we observed allelic association between polymorphic markers flanking the FA group A gene (FANCA) and disease chromosomes in Afrikaners. We genotyped 26 FA families with microsatelli...

  4. Linkage disequilibrium analysis in young populations: Pseudo-vitamin D-deficiency rickets and the founder effect in French Canadians

    Energy Technology Data Exchange (ETDEWEB)

    Labuda, M.; Glorieux, F.H. [McGill Univ., Montreal (Canada); Labuda, D.; Korab-Laskowska, M. [Universite de Montreal (Canada)] [and others

    1996-09-01

    Pseudo-vitamin D-deficiency rickets (PDDR) was mapped close to D12S90 and between proximal D12S312 and distal (D12S305, D12S104) microsatellites that were subsequently found on a single YAC clone. Analysis of a complex haplotype in linkage disequilibrium (LD) with the disease discriminated among distinct founder effects in French Canadian populations in Acadia and in Charlevoix-Saguenay-Lac-Saint-Jean (Ch-SLSJ), as well as an earlier one in precolonial Europe. A simple demographic model suggested the historical age of the founder effect in Ch-SLSJ to be {approximately}12 generations. The corresponding LD data are consistent with this figure when they are analyzed within the framework of Luria-Delbruck model, which takes into account the population growth. Population sampling due to a limited number of first settlers and the rapid demographic expansion appear to have played a major role in the founding of PDDR in Ch-SLSJ and, presumably, other genetic disorders endemic to French Canada. Similarly, the founder effect in Ashkenazim, coinciding with their early settlement in medieval Poland and subsequent expansion eastward, could explain the origin of frequent genetic diseases in this population. 48 refs., 5 figs., 2 tabs.

  5. Founder effect of the RET C611Y mutation in multiple endocrine neoplasia 2A in Denmark

    DEFF Research Database (Denmark)

    Mathiesen, Jes Sloth; Kroustrup, Jens Peter; Vestergaard, Peter

    2017-01-01

    BACKGROUND: Multiple endocrine neoplasia (MEN) 2A and 2B are caused by REarranged during Transfection (RET) germline mutations. In a recent nationwide study we reported of an unusually high prevalence (33%) of families with the C611Y mutation and hypothesized that this might be due to a founder...... effect. We conducted the first nationwide study of haplotypes in MEN2A families aiming to investigate the relatedness and occurrence of de novo mutations among Danish families carrying similar mutations. METHODS: The study included 21 apparently unrelated MEN2A families identified from a nationwide...... Danish RET cohort from 1994 to 2014. Twelve, two, two, three and two families carried the C611Y, C618F, C618Y, C620R and C634R mutation, respectively. Single nucleotide polymorphism chip data and identity by descent analysis were used to assess relatedness. RESULTS: A common founder mutation was found...

  6. Founder effects and the evolution of asymmetrical sexual isolation in a rapidly-speciating clade

    Directory of Open Access Journals (Sweden)

    Kevin P. OH, Gina L. CONTE, Kerry L. SHAW

    2013-04-01

    Full Text Available Sexual isolation resulting from differences in mate choice behaviors is a hallmark of rapidly-speciating lineages. When present, asymmetrical sexual isolation may provide insights into the mechanisms responsible for the evolutionary change in mate signaling traits. In particular, Kaneshiro’s hypothesis suggests that divergence in sexual characters between populations may arise in allopatry when ‘derived’ founding populations are subject to severe population bottlenecks, accompanied by a relaxation of sexual selection relative to ‘ancestral’ source populations. In the present study, we tested predictions of asymmetrical sexual isolation between two allopatric species of Hawaiian Laupala crickets, representing ‘ancestral’ (L. makaio and ‘derived’ (L. nigra taxa. While crickets in this genus are notable for rapid divergence of male courtship songs, these species share similar song types, thus suggesting that patterns of sexual isolation are likely due to other mating cues. Analysis of behavioral responses in conspecific and heterospecific ‘no-choice’ mating trials revealed pronounced asymmetrical isolation in the direction predicted by Kaneshiro’s hypothesis, wherein we observed a significant reduction in mating success for crosses involving ‘derived’ males paired with ‘ancestral’ females, compared to the reciprocal heterospecific and both conspecific pairings. Further dissection of courtship behaviors suggested this difference did not reflect male mate choice, but rather, marked reduced spermatophore acceptance rates by ‘ancestral’ females paired with ‘derived’ males. The results are discussed with respect to founder effect models of speciation and the potential role of chemosensory signals in mate choice in these species [Current Zoology 59 (2: 230-238, 2013].

  7. Testing founder effect speciation: Divergence population genetics of the Spoonbills Platalea regia and Pl. minor (Threskiornithidae, Aves)

    Science.gov (United States)

    Yeung, Carol K.L.; Tsai, Pi-Wen; Chesser, R. Terry; Lin, Rong-Chien; Yao, Cheng-Te; Tian, Xiu-Hua; Li, Shou-Hsien

    2011-01-01

    Although founder effect speciation has been a popular theoretical model for the speciation of geographically isolated taxa, its empirical importance has remained difficult to evaluate due to the intractability of past demography, which in a founder effect speciation scenario would involve a speciational bottleneck in the emergent species and the complete cessation of gene flow following divergence. Using regression-weighted approximate Bayesian computation, we tested the validity of these two fundamental conditions of founder effect speciation in a pair of sister species with disjunct distributions: the royal spoonbill Platalea regia in Australasia and the black-faced spoonbill Pl. minor in eastern Asia. When compared with genetic polymorphism observed at 20 nuclear loci in the two species, simulations showed that the founder effect speciation model had an extremely low posterior probability (1.55 × 10-8) of producing the extant genetic pattern. In contrast, speciation models that allowed for postdivergence gene flow were much more probable (posterior probabilities were 0.37 and 0.50 for the bottleneck with gene flow and the gene flow models, respectively) and postdivergence gene flow persisted for a considerable period of time (more than 80% of the divergence history in both models) following initial divergence (median = 197,000 generations, 95% credible interval [CI]: 50,000-478,000, for the bottleneck with gene flow model; and 186,000 generations, 95% CI: 45,000-477,000, for the gene flow model). Furthermore, the estimated population size reduction in Pl. regia to 7,000 individuals (median, 95% CI: 487-12,000, according to the bottleneck with gene flow model) was unlikely to have been severe enough to be considered a bottleneck. Therefore, these results do not support founder effect speciation in Pl. regia but indicate instead that the divergence between Pl. regia and Pl. minor was probably driven by selection despite continuous gene flow. In this light, we

  8. Molecular and genealogical evidence for a founder effect in Fanconi anemia families of the Afrikaner population of South Africa

    Science.gov (United States)

    Tipping, A. J.; Pearson, T.; Morgan, N. V.; Gibson, R. A.; Kuyt, L. P.; Havenga, C.; Gluckman, E.; Joenje, H.; de Ravel, T.; Jansen, S.; Mathew, C. G.

    2001-01-01

    Fanconi anemia (FA) is a rare, genetically heterogeneous autosomal recessive disorder associated with progressive aplastic anemia, congenital abnormalities, and cancer. FA has a very high incidence in the Afrikaner population of South Africa, possibly due to a founder effect. Previously we observed allelic association between polymorphic markers flanking the FA group A gene (FANCA) and disease chromosomes in Afrikaners. We genotyped 26 FA families with microsatellite and single nucleotide polymorphic markers and detected five FANCA haplotypes. Mutation scanning of the FANCA gene revealed association of these haplotypes with four different mutations. The most common was an intragenic deletion of exons 12–31, accounting for 60% of FA chromosomes in 46 unrelated Afrikaner FA patients, while two other mutations accounted for an additional 20%. Screening for these mutations in the European populations ancestral to the Afrikaners detected one patient from the Western Ruhr region of Germany who was heterozygous for the major deletion. The mutation was associated with the same unique FANCA haplotype as in Afrikaner patients. Genealogical investigation of 12 Afrikaner families with FA revealed that all were descended from a French Huguenot couple who arrived at the Cape on June 5, 1688, whereas mutation analysis showed that the carriers of the major mutation were descendants of this same couple. The molecular and genealogical evidence is consistent with transmission of the major mutation to Western Germany and the Cape near the end of the 17th century, confirming the existence of a founder effect for FA in South Africa. PMID:11344308

  9. Breakdown of the Scab Resistance Gene Vf in Apple Leads to a Founder Effect in Populations of the Fungal Pathogen Venturia inaequalis.

    Science.gov (United States)

    Guérin, Fabien; Le Cam, Bruno

    2004-04-01

    ABSTRACT The recent breakdown of Vf, a major resistance gene to apple scab, provided an opportunity to analyze a population genetic process within the matching virulent subpopulation of the fungus Venturia inaequalis. We utilized the amplified fragment length polymorphism technique and allelic variation at four microsatellite loci to assess genetic structure of 133 isolates of V. inaequalis from a single commercial apple orchard sampled from one cultivar carrying the Vf gene (Judeline) and three cultivars devoid of the Vf gene. Both analyses indicated a strong decrease of the genetic diversity among isolates from the Vf cultivar compared with the high level of diversity among isolates from the three other cultivars. This leads to a high genetic differentiation between virVf and avrVf groups (F(ST) > 0.17). Analyses of the genetic distance between AFLP patterns based on the Jaccard index indicate that all virVf isolates could be assigned to a single clonal lineage. These results lead us to conclude that the clonal structure of the population isolated from the Vf cultivar is an example of a founder effect in response to a resistance gene breakdown and it is likely that this event occurred in the orchard during the sampling year.

  10. Founder representation and effective population size in old versus young breeds-genetic diversity of Finnish and Nordic Spitz.

    Science.gov (United States)

    Kumpulainen, M; Anderson, H; Svevar, T; Kangasvuo, I; Donner, J; Pohjoismäki, J

    2017-10-01

    Finnish Spitz is 130-year-old breed and has been highly popular in Finland throughout its history. Nordic Spitz is very similar to Finnish Spitz by origin and use, but is a relatively recent breed with much smaller population size. To see how breed age and breeding history have influenced the current population, we performed comprehensive population genetic analysis using pedigree data of 28,119 Finnish and 9,009 Nordic Spitzes combined with genomewide single nucleotide polymorphism (SNP) data from 135 Finnish and 110 Nordic Spitzes. We found that the Finnish Spitz has undergone repeated male bottlenecks resulting in dramatic loss of genetic diversity, reflected by 20 effective founders (f a ) and mean heterozygosity (Hz) of 0.313. The realized effective population size in the breed based on pedigree analysis (N¯ec) is 168, whereas the genetic effective population size (N eg ) computed the decay of linkage disequilibrium (r 2 ) is only 57 individuals. Nordic Spitz, although once been near extinction, has not been exposed to similar repeated bottlenecks than Finnish Spitz and had f a of 27 individuals. However, due to the smaller total population size, the breed has also smaller effective population size than Finnish Spitz (N¯ec = 98 and N eg  = 49). Interestingly, the r 2 data show that the effective population size has contracted dramatically since the establishment of the breed, emphasizing the role of breed standards as constrains for the breeding population. Despite the small population size, Nordic Spitz still maintains SNP heterozygosity levels similar to mixed breed dogs (mean Hz = 0.409). Our study demonstrates that although pedigree analyses cannot provide estimates of the present diversity within a breed, the effective population sizes inferred from them correlate with the genotyping results. The genetic relationships of the northern Spitz breeds and the benefits of the open breed registry are discussed. © 2017 Blackwell Verlag GmbH.

  11. Armadillos exhibit less genetic polymorphism in North America than in South America: nuclear and mitochondrial data confirm a founder effect in Dasypus novemcinctus (Xenarthra).

    OpenAIRE

    Huchon, Dorothée; Delsuc, Frédéric; Catzeflis, François,; Douzery, Emmanuel,

    1999-01-01

    International audience; Heterozygosity at eight nuclear enzymatic loci and mitochondrial DNA control region (D-loop) sequence polymorphism was compared between North and South American nine-banded armadillos (Dasypus novemcinctus: Xenarthra, Dasypodidae). All markers revealed a striking genetic homogeneity amongst Texas, Louisiana, and Mississippi individuals, vs. the usual level of polymorphism for the French Guiana population. This may reflect a founder effect during colonization of North A...

  12. Multiple Local and Recent Founder Effects of TGM1 in Spanish Families

    Science.gov (United States)

    Fachal, Laura; Rodríguez-Pazos, Laura; Ginarte, Manuel; Toribio, Jaime; Salas, Antonio; Vega, Ana

    2012-01-01

    Background Mutations in the TGM1 gene encoding transglutaminase 1 are a major cause of autosomal recessive congenital ichthyosis. In the Galician (NW Spain) population, three mutations, c.2278C>T, c.1223_1227delACAC and c.984+1G>A, were observed at high frequency, representing ∼46%, ∼21% and ∼13% of all TGM1 gene mutations, respectively. Moreover, these mutations were reported only once outside of Galicia, pointing to the existence of historical episodes of local severe genetic drift in this region. Methodology/Principal Findings In order to determine whether these mutations were inherited from a common ancestor in the Galician population, and to estimate the number of generations since their initial appearance, we carried out a haplotype-based analysis by way of genotyping 21 SNPs within and flanking the TGM1 gene and 10 flanking polymorphic microsatellite markers spanning a region of 12 Mb. Two linkage disequilibrium based methods were used to estimate the time to the most recent common ancestor (TMRCA), while a Bayesian-based procedure was used to estimate the age of the two mutations. Haplotype reconstruction from unphased genotypes of all members of the affected pedigrees indicated that all carriers for each of the two mutations harbored the same haplotypes, indicating common ancestry. Conclusions/Significance In good agreement with the documentation record and the census, both mutations arose between 2,800–2,900 years ago (y.a.), but their TMRCA was in the range 600–1,290 y.a., pointing to the existence of historical bottlenecks in the region followed by population growth. This demographic scenario finds further support on a Bayesian Coalescent Analysis based on TGM1 haplotypes that allowed estimating the occurrence of a dramatic reduction of effective population size around 900–4,500 y.a. (95% highest posterior density) followed by exponential growth. PMID:22511925

  13. Finding quantum effects in strong classical potentials

    Science.gov (United States)

    Hegelich, B. Manuel; Labun, Lance; Labun, Ou Z.

    2017-06-01

    The long-standing challenge to describing charged particle dynamics in strong classical electromagnetic fields is how to incorporate classical radiation, classical radiation reaction and quantized photon emission into a consistent unified framework. The current, semiclassical methods to describe the dynamics of quantum particles in strong classical fields also provide the theoretical framework for fundamental questions in gravity and hadron-hadron collisions, including Hawking radiation, cosmological particle production and thermalization of particles created in heavy-ion collisions. However, as we show, these methods break down for highly relativistic particles propagating in strong fields. They must therefore be improved and adapted for the description of laser-plasma experiments that typically involve the acceleration of electrons. Theory developed from quantum electrodynamics, together with dedicated experimental efforts, offer the best controllable context to establish a robust, experimentally validated foundation for the fundamental theory of quantum effects in strong classical potentials.

  14. Evolutionary History of the Live-Bearing Endemic Allotoca diazi Species Complex (Actinopterygii, Goodeinae: Evidence of Founder Effect Events in the Mexican Pre-Hispanic Period.

    Directory of Open Access Journals (Sweden)

    Diushi Keri Corona-Santiago

    Full Text Available The evolutionary history of Mexican ichthyofauna has been strongly linked to natural events, and the impact of pre-Hispanic cultures is little known. The live-bearing fish species Allotoca diazi, Allotoca meeki and Allotoca catarinae occur in areas of biological, cultural and economic importance in central Mexico: Pátzcuaro basin, Zirahuén basin, and the Cupatitzio River, respectively. The species are closely related genetically and morphologically, and hypotheses have attempted to explain their systematics and biogeography. Mitochondrial DNA and microsatellite markers were used to investigate the evolutionary history of the complex. The species complex shows minimal genetic differentiation. The separation of A. diazi and A. meeki was dated to 400-7000 years ago, explained by geological and climate events. A bottleneck and reduction of genetic diversity in Allotoca diazi was detected, attributed to recent climate fluctuations and anthropogenic activity. The isolation of A. catarinae occurred ~1900 years ago. No geological events are documented in the area during this period, but the date is contemporary with P'urhépecha culture settlements. This founder effect represents the first evidence of fish species translocation by a pre-Hispanic culture of Mexico. The response of the complex to climate fluctuation, geological changes and human activity in the past and the future according to the ecological niches predictions indicates areas of vulnerability and important information for conservation. The new genetic information showed that the Allotoca diazi complex consist of two genetic groups with an incomplete lineage sorting pattern: Pátzcuaro and Zirahuén lakes, and an introduced population in the Cupatitzio River.

  15. Evolutionary History of the Live-Bearing Endemic Allotoca diazi Species Complex (Actinopterygii, Goodeinae): Evidence of Founder Effect Events in the Mexican Pre-Hispanic Period.

    Science.gov (United States)

    Corona-Santiago, Diushi Keri; Doadrio, Ignacio; Domínguez-Domínguez, Omar

    2015-01-01

    The evolutionary history of Mexican ichthyofauna has been strongly linked to natural events, and the impact of pre-Hispanic cultures is little known. The live-bearing fish species Allotoca diazi, Allotoca meeki and Allotoca catarinae occur in areas of biological, cultural and economic importance in central Mexico: Pátzcuaro basin, Zirahuén basin, and the Cupatitzio River, respectively. The species are closely related genetically and morphologically, and hypotheses have attempted to explain their systematics and biogeography. Mitochondrial DNA and microsatellite markers were used to investigate the evolutionary history of the complex. The species complex shows minimal genetic differentiation. The separation of A. diazi and A. meeki was dated to 400-7000 years ago, explained by geological and climate events. A bottleneck and reduction of genetic diversity in Allotoca diazi was detected, attributed to recent climate fluctuations and anthropogenic activity. The isolation of A. catarinae occurred ~1900 years ago. No geological events are documented in the area during this period, but the date is contemporary with P'urhépecha culture settlements. This founder effect represents the first evidence of fish species translocation by a pre-Hispanic culture of Mexico. The response of the complex to climate fluctuation, geological changes and human activity in the past and the future according to the ecological niches predictions indicates areas of vulnerability and important information for conservation. The new genetic information showed that the Allotoca diazi complex consist of two genetic groups with an incomplete lineage sorting pattern: Pátzcuaro and Zirahuén lakes, and an introduced population in the Cupatitzio River.

  16. The roles of geography and founder effects in promoting host-associated differentiation in the generalist bogus yucca moth Prodoxus decipiens.

    Science.gov (United States)

    Darwell, C T; Fox, K A; Althoff, D M

    2014-12-01

    There is ample evidence that host shifts in plant-feeding insects have been instrumental in generating the enormous diversity of insects. Changes in host use can cause host-associated differentiation (HAD) among populations that may lead to reproductive isolation and eventual speciation. The importance of geography in facilitating this process remains controversial. We examined the geographic context of HAD in the wide-ranging generalist yucca moth Prodoxus decipiens. Previous work demonstrated HAD among sympatric moth populations feeding on two different Yucca species occurring on the barrier islands of North Carolina, USA. We assessed the genetic structure of P. decipiens across its entire geographic and host range to determine whether HAD is widespread in this generalist herbivore. Population genetic analyses of microsatellite and mtDNA sequence data across the entire range showed genetic structuring with respect to host use and geography. In particular, genetic differentiation was relatively strong between mainland populations and those on the barrier islands of North Carolina. Finer scale analyses, however, among sympatric populations using different host plant species only showed significant clustering based on host use for populations on the barrier islands. Mainland populations did not form population clusters based on host plant use. Reduced genetic diversity in the barrier island populations, especially on the derived host, suggests that founder effects may have been instrumental in facilitating HAD. In general, results suggest that the interplay of local adaptation, geography and demography can determine the tempo of HAD. We argue that future studies should include comprehensive surveys across a wide range of environmental and geographic conditions to elucidate the contribution of various processes to HAD. © 2014 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2014 European Society For Evolutionary Biology.

  17. Genetic structure of the poplar rust fungus Melampsora larici-populina: evidence for isolation by distance in Europe and recent founder effects overseas.

    Science.gov (United States)

    Barrès, Benoît; Halkett, Fabien; Dutech, Cyril; Andrieux, Axelle; Pinon, Jean; Frey, Pascal

    2008-09-01

    Dispersal has a great impact on the genetic structure of populations, but remains difficult to estimate by direct measures. In particular, gradual and stochastic dispersal are often difficult to assess and to distinguish, although they have different evolutionary consequences. Plant pathogens, especially rust fungi, are suspected to display both dispersal modes, though on different spatial scales. In this study, we inferred dispersal capacities of the poplar rust fungus Melampsora larici-populina by examining the genetic diversity and structure of 13 populations from eight European and two overseas countries in the Northern hemisphere. M. larici-populina was sampled from both cultivated hybrid poplars and on the wild host, Populus nigra. The populations were analyzed with 11 microsatellite and 8 virulence markers. Although isolates displayed different virulence profiles according to the host plant, neutral markers revealed little population differentiation with respect to the type of host. This suggests an absence of reproductive isolation between populations sampled from cultivated and wild poplars. Conversely, studying the relationship between geographic and genetic structure allowed us to distinguish between isolation by distance (IBD) patterns and long distance dispersal (LDD) events. The European populations exhibited a significant IBD pattern, suggesting a regular and gradual dispersal of the pathogen over this spatial scale. Nonetheless, the genetic differentiation between these populations was low, suggesting an important gene flow on a continental scale. The two overseas populations from Iceland and Canada were shown to result from rare LDD events, and exhibited signatures of strong founder effects. Furthermore, the high genetic differentiation between both populations suggested that these two recent introductions were independent. This study illustrated how the proper use of population genetics methods can enable contrasted dispersal modes to be revealed.

  18. Wormhole effect in a strong topological insulator

    Science.gov (United States)

    Rosenberg, G.; Guo, H.-M.; Franz, M.

    2010-07-01

    An infinitely thin solenoid carrying magnetic flux Φ (a “Dirac string”) inserted into an ordinary band insulator has no significant effect on the spectrum of electrons. In a strong topological insulator, remarkably, such a solenoid carries protected gapless one-dimensional fermionic modes when Φ=hc/2e . These modes are spin-filtered and represent a distinct bulk manifestation of the topologically nontrivial insulator. We establish this “wormhole” effect by both general qualitative considerations and by numerical calculations within a minimal lattice model. We also discuss the possibility of experimental observation of a closely related effect in artificially engineered nanostructures.

  19. Strong curvature effects in Neumann wave problems

    DEFF Research Database (Denmark)

    Willatzen, Morten; Pors, A.; Gravesen, Jens

    2012-01-01

    Waveguide phenomena play a major role in basic sciences and engineering. The Helmholtz equation is the governing equation for the electric field in electromagnetic wave propagation and the acoustic pressure in the study of pressure dynamics. The Schro¨dinger equation simplifies to the Helmholtz...... equation for a quantum-mechanical particle confined by infinite barriers relevant in semiconductor physics. With this in mind and the interest to tailor waveguides towards a desired spectrum and modal pattern structure in classical structures and nanostructures, it becomes increasingly important...... to understand the influence of curvature effects in waveguides. In this work, we demonstrate analytically strong curvature effects for the eigenvalue spectrum of the Helmholtz equation with Neumann boundary conditions in cases where the waveguide cross section is a circular sector. It is found that the linear...

  20. Fragile X founder effect and distribution of CGG repeats among the mentally retarded population of Andalusia, South Spain

    Directory of Open Access Journals (Sweden)

    Yolanda de Diego

    2002-01-01

    Full Text Available Fragile X syndrome is the most common inherited form of mental retardation. We investigated the prevalence of the Fragile X syndrome in the population with mental retardation of unknown etiology in Andalusia, South Spain. We analyzed 322 unrelated patients (280 males and 42 females, and found a fragile X syndrome frequency of 6.5%. Among the non-fragile X chromosomes, the 29 CGG repeat was the most common allele. At the linked microsatellite DXS548 locus, we found a new allele which we called "allele 10" (17 CA. Similar to other south European populations, allele 2 (25 CA at the DXS548 locus and the fragile X allele were in linkage disequilibrium supporting the idea of a common founder chromosome predisposing to the CGG expansion.

  1. The CHEK2 del5395 is a founder mutation without direct effects for cancer risk in the latvian population

    Directory of Open Access Journals (Sweden)

    Plonis J

    2015-12-01

    Full Text Available Our objective was to determine: 1 whether the checkpoint kinase 2 (CHEK2 del5395 (g.27417113-27422508 del, NC_000022.11 is a founder mutation in the Latvian population, 2 if there is an association between CHEK2 del5395 mutation and cancer risk, and 3 and whether the CHEK2 del5395 mutation impacts cancer predisposition in Chernobyl disaster liquidators (the civil and military personnel who were called upon to deal with consequences of the 1986 nuclear disaster as well as geriatric populations. We recruited 438 breast cancer patients, 568 colorectal cancer patients, 399 ovarian cancer patients, 419 prostate cancer patients, 526 healthy blood donors, 480 Chernobyl disaster liquidators and 444 geriatric cancer-free participants. DNA samples were isolated from blood samples and subjected to multiplex polymerase chain reaction (PCR. The truncation of del5395 was estimated by fragment size of the multiplex PCR.All groups were compared to the healthy blood donors using Fisher’s exact test. All p values were two-sided and the odds ratios (OR calculated by two-by-two table. In cancer groups, the del5395 mutation was most frequently observed in the ovarian cancer group (1.00%, OR = 1.32. In control groups, the del5395 mutation was most frequent (0.76% in the healthy donors, which exceeded its frequency in the Chernobyl liquidators group and the geriatric group by 0.01 and 0.08%, respectively. For all groups, the OR appeared to be >1 only in ovarian cancer patients. However, OR rates showed no statistical significance in either cancer or control groups, with the p value fluctuating within the range of 0.39-1.00. The CHEK2 gene del5395 is a founder mutation in the Latvian population, which, however, does not have a direct impact on genetic predisposition toward colorectal, breast, ovarian and prostate cancer.

  2. Strong curvature effects in Neumann wave problems

    International Nuclear Information System (INIS)

    Willatzen, M.; Pors, A.; Gravesen, J.

    2012-01-01

    Waveguide phenomena play a major role in basic sciences and engineering. The Helmholtz equation is the governing equation for the electric field in electromagnetic wave propagation and the acoustic pressure in the study of pressure dynamics. The Schrödinger equation simplifies to the Helmholtz equation for a quantum-mechanical particle confined by infinite barriers relevant in semiconductor physics. With this in mind and the interest to tailor waveguides towards a desired spectrum and modal pattern structure in classical structures and nanostructures, it becomes increasingly important to understand the influence of curvature effects in waveguides. In this work, we demonstrate analytically strong curvature effects for the eigenvalue spectrum of the Helmholtz equation with Neumann boundary conditions in cases where the waveguide cross section is a circular sector. It is found that the linear-in-curvature contribution originates from parity symmetry breaking of eigenstates in circular-sector tori and hence vanishes in a torus with a complete circular cross section. The same strong curvature effect is not present in waveguides subject to Dirichlet boundary conditions where curvature contributions contribute to second-order in the curvature only. We demonstrate this finding by considering wave propagation in a circular-sector torus corresponding to Neumann and Dirichlet boundary conditions, respectively. Results for relative eigenfrequency shifts and modes are determined and compared with three-dimensional finite element method results. Good agreement is found between the present analytical method using a combination of differential geometry with perturbation theory and finite element results for a large range of curvature ratios.

  3. Recurrent missense mutations in TMEM43 (ARVD5) due to founder effects cause arrhythmogenic cardiomyopathies in the UK and Canada

    KAUST Repository

    Haywood, Annika

    2012-11-15

    AimsAutosomal dominant arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) (in the group of arrhythmogenic cardiomyopathies) is a common cause of sudden cardiac death in young adults. It is both clinically and genetically heterogeneous, with 12 loci (ARVC/D1-12) and eight genes identified, the majority of which encode structural proteins of cardiac desmosomes. The most recent gene identified, TMEM43, causes disease due to a missense mutation in a non-desmosomal gene (p.S358L) in 15 extended families from Newfoundland, Canada. To determine whether mutations in TMEM43 cause ARVC/D and arrhythmogenic cardiomyopathy in other populations, we fully re-sequenced TMEM43 on 143 ARVC/D probands (families) from the UK and 55 probands (from 55 families) from Newfoundland.Methods and resultsBidirectional sequencing of TMEM43 including intron-exon boundaries revealed 33 variants, the majority located in non-coding regions of TMEM43. For the purpose of validation, families of probands with rare, potentially deleterious coding variants were subjected to clinical and molecular follow-up. Three missense variants of uncertain significance (p.R28W, p.E142K, p.R312W) were located in highly conserved regions of the TMEM43 protein. One variant (p.R312W) also co-segregated with relatives showing clinical signs of disease. Genotyping and expansion of the disease-associated haplotype in subjects with the p.R312W variant from Newfoundland, Canada, and the UK suggest common ancestry.ConclusionAlthough the p.R312W variant was found in controls (3/378), identification of an ancestral disease p R312W haplotype suggests that the p.R312W variant is a pathogenic founder mutation. © 2012 The Author.

  4. Impact of historical founder effects and a recent bottleneck on MHC variability in Commander Arctic foxes (Vulpes lagopus)

    Science.gov (United States)

    Ploshnitsa, Anna I; Goltsman, Mikhail E; Macdonald, David W; Kennedy, Lorna J; Sommer, Simone

    2012-01-01

    Populations of Arctic foxes (Vulpes lagopus) have been isolated on two of the Commander Islands (Bering and Mednyi) from the circumpolar distributed mainland population since the Pleistocene. In 1970–1980, an epizootic outbreak of mange caused a severe population decline on Mednyi Island. Genes of the major histocompatibility complex (MHC) play a primary role in infectious disease resistance. The main objectives of our study were to compare contemporary variation of MHC class II in mainland and island Arctic foxes, and to document the effects of the isolation and the recent bottleneck on MHC polymorphism by analyzing samples from historical and contemporary Arctic foxes. In 184 individuals, we found 25 unique MHC class II DRB and DQB alleles, and identified evidence of balancing selection maintaining allelic lineages over time at both loci. Twenty different MHC alleles were observed in mainland foxes and eight in Bering Island foxes. The historical Mednyi population contained five alleles and all contemporary individuals were monomorphic at both DRB and DQB. Our data indicate that despite positive and diversifying selection leading to elevated rates of amino acid replacement in functionally important antigen-binding sites, below a certain population size, balancing selection may not be strong enough to maintain genetic diversity in functionally important genes. This may have important fitness consequences and might explain the high pathogen susceptibility in some island populations. This is the first study that compares MHC diversity before and after a bottleneck in a wild canid population using DNA from museum samples. PMID:22408734

  5. Founder of a scientific school on plasma

    International Nuclear Information System (INIS)

    Anon

    2003-01-01

    The academician Mikhail Aleksandrovitch Leontovitch is a physicist-theorist of a wide profile (physical optics, oscillation theory, acoustics, statistical physics, thermodynamics), who became the founder of the largest scientific schools on the radiophysics and plasma physics. Namely due to his effective leadership in developing the theory our theoretical studies on the controlled thermonuclear synthesis reached high level and facilitated the success of the experiment [ru

  6. Strong crystal size effect on deformation twinning

    DEFF Research Database (Denmark)

    Yu, Qian; Shan, Zhi-Wei; Li, Ju

    2010-01-01

    find that the stress required for deformation twinning increases drastically with decreasing sample size of a titanium alloy single crystal7, 8, until the sample size is reduced to one micrometre, below which the deformation twinning is entirely replaced by less correlated, ordinary dislocation...... plasticity. Accompanying the transition in deformation mechanism, the maximum flow stress of the submicrometre-sized pillars was observed to saturate at a value close to titanium’s ideal strength9, 10. We develop a ‘stimulated slip’ model to explain the strong size dependence of deformation twinning....... The sample size in transition is relatively large and easily accessible in experiments, making our understanding of size dependence11, 12, 13, 14, 15, 16, 17 relevant for applications....

  7. Strong coupling effects in hybrid plexitonic systems

    Science.gov (United States)

    Melnikau, Dzmitry; Esteban, Ruben; Govyadinov, Alexander A.; Savateeva, Diana; Simon, Thomas; Sánchez-Iglesias, Ana; Grzelczak, Marek; Schmidt, Mikolaj K.; Urban, Alexander S.; Liz-Marzán, Luis M.; Feldmann, Jochen; Aizpurua, Javier; Rakovich, Yury P.

    2017-08-01

    We investigated the interactions between localized plasmons in gold nanorods and excitons in J-aggregates and were able to track an anticrossing behavior of the hybridized modes both in the extinction and in the photoluminescence spectra of this hybrid system. We identified the nonlinear optical behavior of this system by transient absorption spectroscopy. Finally using magnetic circular dichroism spectroscopy we showed that nonmagnetic organic molecules exhibit magnetooptical response due to binding to a plasmonic nanoparticles. In our experiments we also studied the effect of detuning as well as the effect of off- and on resonance excitation on the hybrid states

  8. Disorder effects in strongly correlated uranium compounds

    International Nuclear Information System (INIS)

    Suellow, S.; Maple, M.B.; Tomuta, D.; Nieuwenhuys, G.J.; Menovsky, A.A.; Mydosh, J.A.; Chau, R.

    2001-01-01

    Moderate levels of crystallographic disorder can dramatically affect the ground-state properties of heavy fermion compounds. In particular, the role of disorder close to a quantum critical point has been investigated in detail. However, crystallographic disorder is equally effective in altering the properties of magnetically ordered heavy fermion compounds like URh 2 Ge 2 , where disorder-induced spin-glass behavior has been observed. In this system, moreover, the magnetic ground state can be tuned from a spin-glass to a long-range ordered antiferromagnetic one by means of an annealing treatment. The transformation of the magnetic state is accompanied by a transition in the transport properties from 'quasi-insulating' (dρ/dT 2 Ge 2 will be discussed. Of particular interest is the resistivity of as-grown URh 2 Ge 2 , which resembles the Non-Fermi-liquid system UCu 4 Pd, suggesting that a common mechanism - the crystallographic disorder - controls the transport properties of these materials

  9. Segregation of S292F TPO gene mutation in three large Tunisian families with thyroid dyshormonogenesis: evidence of a founder effect.

    Science.gov (United States)

    Bougacha-Elleuch, Noura; Charfi, Nadia; Miled, Nabil; Bouhajja, Houda; Belguith, Neila; Mnif, Mouna; Jaurge, Paula; Chikhrouhou, Nessrine; Ayadi, Hammadi; Hachicha, Mongia; Abid, Mohamed

    2015-11-01

    We aimed to identify causal mutation(s) in 13 patients with thyroid dyshormonogenesis (TD) from three consanguineous Tunisian families. A 12-year clinical follow-up showed phenotypic variability ranging from the presence to the absence of goiter, sensorineural deafness, and mental retardation. Genetic analysis using microsatellite markers within two candidate genes (TPO and PDS) gave evidence of linkage with the TPO gene. Sequencing of its 17 exons and their flanking intron-exon junctions revealed the previously described c.875C>T (p.S292F) mutation in homozygous state. No additional mutations were found in either a 900 bp of the TPO gene promoter or PDS gene. In silico analysis showed that p.S292F mutation might reduce the catalytic cavity of the TPO which would restrict access of a potential substrate to the catalytic pocket. Using 4SNPs and one microsatellite marker in the TPO gene, an associated haplotype: G-C-G-G-214 was found, giving evidence of a founder mutation. This is the first description of a TD causing mutation in Tunisia and thus may help to develop a genetic screening protocol for congenital hypothyroidism in the studied region. Although structural modeling suggested a pathogenic effect of this mutation, functional studies are needed. Additional causing and/or modifier genes, together with late diagnosis could explain the clinical variability observed in our patients.

  10. OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC

    International Nuclear Information System (INIS)

    FISCHER, W.; BLASKIEWICZ, M.; BRENNAN, J.M.; CAMERON, P.; CONNOLLY, R.; MONTAG, C.; PEGGS, S.; PILAT, F.; PTITSYN, V.; TEPIKIAN, S.; TRBOJEVIC, D.; VAN ZEIJTS, J.

    2003-01-01

    RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far

  11. Medical mall founders' satisfaction and integrated management requirements

    Science.gov (United States)

    2016-01-01

    Summary Medical malls help provide integrated medical services and the effective and efficient independent management of multiple clinics, pharmacies and other medical facilities. Primary care in an aging society is a key issue worldwide and the establishment of a new model for primary care in Japanese medical malls is needed. Understanding the requirements of integrated management that contribute to the improvement of medical mall founders' satisfaction levels will help provide better services. We conducted a questionnaire survey targeting 1840 medical facilities nationwide; 351 facilities responded (19.1%). We performed comparative analyses on founders' satisfaction levels according to years in business, department/area, founder's relationship, decision‐making system and presence/absence of liaison role. A total of 70% of medical malls in Japan have adjacent relationships with no liaison role in most cases; however, 60% of founders are satisfied. Integrated management requirements involve establishing the mall with peers from the same medical office unit or hospital, and establishing a system in which all founders can participate in decision‐making (council system) or one where each general practitioner (GP) independently runs a clinic without communicating with others. The council system can ensure the capability of general practitioners to treat many primary care patients in the future. © 2016 The Authors. The International Journal of Health Planning and Management Published by John Wiley & Sons Ltd PMID:27218206

  12. What founders in developing countries learn about organizing microenterprise growth

    DEFF Research Database (Denmark)

    Pötz, Katharina Anna; Hjortsø, Carsten Nico Portefée

    of microenterprise growth in Tanzania, this study therefore investigates what microenterprise founders learn about effective resource orchestration (RO) from organizational process experience. Our findings suggest that they first learn to orchestrate relatively simple and informal ‘micro-programs’ for gathering...

  13. Strong expectations cancel locality effects: evidence from Hindi.

    Directory of Open Access Journals (Sweden)

    Samar Husain

    Full Text Available Expectation-driven facilitation (Hale, 2001; Levy, 2008 and locality-driven retrieval difficulty (Gibson, 1998, 2000; Lewis & Vasishth, 2005 are widely recognized to be two critical factors in incremental sentence processing; there is accumulating evidence that both can influence processing difficulty. However, it is unclear whether and how expectations and memory interact. We first confirm a key prediction of the expectation account: a Hindi self-paced reading study shows that when an expectation for an upcoming part of speech is dashed, building a rarer structure consumes more processing time than building a less rare structure. This is a strong validation of the expectation-based account. In a second study, we show that when expectation is strong, i.e., when a particular verb is predicted, strong facilitation effects are seen when the appearance of the verb is delayed; however, when expectation is weak, i.e., when only the part of speech "verb" is predicted but a particular verb is not predicted, the facilitation disappears and a tendency towards a locality effect is seen. The interaction seen between expectation strength and distance shows that strong expectations cancel locality effects, and that weak expectations allow locality effects to emerge.

  14. Strong Gravity Effects of Rotating Black Holes: Quasiperiodic Oscillations

    OpenAIRE

    Aliev, Alikram N.; Esmer, Göksel Daylan; Talazan, Pamir

    2012-01-01

    We explore strong gravity effects of the geodesic motion in the spacetime of rotating black holes in general relativity and braneworld gravity. We focus on the description of the motion in terms of three fundamental frequencies: The orbital frequency, the radial and vertical epicyclic frequencies. For a Kerr black hole, we perform a detailed numerical analysis of these frequencies at the innermost stable circular orbits and beyond them as well as at the characteristic stable orbits, at which ...

  15. New results on strong-interaction effects in antiprotonic hydrogen

    CERN Document Server

    Gotta, D; Augsburger, M A; Borchert, G L; Castelli, C M; Chatellard, D; El-Khoury, P; Egger, J P; Gorke, H; Hauser, P R; Indelicato, P J; Kirch, K; Lenz, S; Nelms, N; Rashid, K; Schult, O W B; Siems, T; Simons, L M

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the low-energy antiproton ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using charge-coupled devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction. (33 refs).

  16. New results on strong-interaction effects in antiprotonic hydrogen

    International Nuclear Information System (INIS)

    Anagnostopoulos, D. F.; Augsburger, M.; Borchert, G.; Castelli, C.; Chatellard, D.; El-Khoury, P.; Egger, J.-P.; Gorke, H.; Gotta, D.; Hauser, P.; Indelicato, P.; Kirch, K.; Lenz, S.; Nelms, N.; Rashid, K.; Schult, O. W. B.; Siems, Th.; Simons, L. M.

    1999-01-01

    Lyman and Balmer transitions of antiprotonic hydrogen and deuterium have been measured at the Low-Energy Antiproton Ring LEAR at CERN in order to determine the strong interaction effects. The X-rays were detected using Charge-Coupled Devices (CCDs) and a reflection type crystal spectrometer. The results of the measurements support the meson-exchange models describing the medium and long range part of the nucleon-antinucleon interaction

  17. ANALYSIS OF INDUSTRIAL INJURIES OF FOUNDERS

    Directory of Open Access Journals (Sweden)

    A. M. Lazarenkov

    2006-01-01

    Full Text Available The analysis of occupational traumatism of founders is given. It is shown, that wastes connected with termination of work capacity due to illness or traumatism cause not only physical but economical damage as well.

  18. Superconducting proximity effect in the strong-coupling limit

    International Nuclear Information System (INIS)

    Wilvert, W.

    1975-01-01

    A generalization of the theory of the superconducting proximity effect is presented which takes into account strong-coupling in the superconductors. The results are found to agree with a model of weak-coupled superconductors with differing Debye frequencies which are in proximity. It is found that logarithmic averaging of phonon frequencies is an improvement on the original McMillan theory (1968). Comparison of the theory with data on thin films and on eutectic alloys is found to give good agreement. 19 references

  19. Strong dynamical effects during stick-slip adhesive peeling.

    Science.gov (United States)

    Dalbe, Marie-Julie; Santucci, Stéphane; Cortet, Pierre-Philippe; Vanel, Loïc

    2014-01-07

    We consider the classical problem of the stick-slip dynamics observed when peeling a roller adhesive tape at a constant velocity. From fast imaging recordings, we extract the dependence of the stick and slip phase durations on the imposed peeling velocity and peeled ribbon length. Predictions of Maugis and Barquins [in Adhesion 12, edited by K. W. Allen, Elsevier ASP, London, 1988, pp. 205-222] based on a quasistatic assumption succeed to describe quantitatively our measurements of the stick phase duration. Such a model however fails to predict the full stick-slip cycle duration, revealing strong dynamical effects during the slip phase.

  20. Effectiveness of Advanced Stay Strong, Stay Healthy in Community Settings

    Directory of Open Access Journals (Sweden)

    Emily M. Crowe MS

    2015-07-01

    Full Text Available The goal of this research was to investigate the effectiveness of the 10-week, University of Missouri (MU Extension strength training program Advanced Stay Strong, Stay Healthy (ASSSH. It was hypothesized that the program can improve strength, balance, agility, and flexibility—all physical measures of falling among seniors. Matched pair t tests were used to compare differences in five physical measures of health, body composition, and percent body fat (%BF. Two-way ANOVA was conducted to examine the age effects on changes in physical health from the start and finish of the exercise program. Following programming, participants significantly improved strength, flexibility, and balance, and significantly reduced %BF ( p < .05. Our data indicate that ASSSH can improve the physical health of senior citizens and can successfully be translated into community practice by MU Extension professionals.

  1. High prevalence of BRCA1 founder mutations in Greek breast/ovarian families.

    Science.gov (United States)

    Konstantopoulou, I; Tsitlaidou, M; Fostira, F; Pertesi, M; Stavropoulou, A-V; Triantafyllidou, O; Tsotra, E; Tsiftsoglou, A P; Tsionou, C; Droufakou, S; Dimitrakakis, C; Fountzilas, G; Yannoukakos, D

    2014-01-01

    We have screened 473 breast/ovarian cancer patients with family history, aiming to define the prevalence and enrich the spectrum of BRCA1/2 pathogenic mutations occurring in the Greek population. An overall mutation prevalence of 32% was observed. Six BRCA1 recurrent/founder mutations dominate the observed spectrum (58.5% of all mutations found). These include three mutations in exon 20 and three large genomic deletions. Of the 44 different deleterious mutations found in both genes, 16 are novel and reported here for the first time. Correlation with available histopathology data showed that 80% of BRCA1 carriers presented a triple-negative breast cancer phenotype while 82% of BRCA2 carriers had oestrogen receptor positive tumours. This study provides a comprehensive view of the frequency, type and distribution of BRCA1/2 mutations in the Greek population as well as an insight of the screening strategy of choice for patients of Greek origin. We conclude that the Greek population has a diverse mutation spectrum influenced by strong founder effects. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  2. Relative resistance of HIV-1 founder viruses to control by interferon-alpha.

    Science.gov (United States)

    Fenton-May, Angharad E; Dibben, Oliver; Emmerich, Tanja; Ding, Haitao; Pfafferott, Katja; Aasa-Chapman, Marlen M; Pellegrino, Pierre; Williams, Ian; Cohen, Myron S; Gao, Feng; Shaw, George M; Hahn, Beatrice H; Ochsenbauer, Christina; Kappes, John C; Borrow, Persephone

    2013-12-03

    Following mucosal human immunodeficiency virus type 1 (HIV-1) transmission, type 1 interferons (IFNs) are rapidly induced at sites of initial virus replication in the mucosa and draining lymph nodes. However, the role played by IFN-stimulated antiviral activity in restricting HIV-1 replication during the initial stages of infection is not clear. We hypothesized that if type 1 IFNs exert selective pressure on HIV-1 replication in the earliest stages of infection, the founder viruses that succeed in establishing systemic infection would be more IFN-resistant than viruses replicating during chronic infection, when type 1 IFNs are produced at much lower levels. To address this hypothesis, the relative resistance of virus isolates derived from HIV-1-infected individuals during acute and chronic infection to control by type 1 IFNs was analysed. The replication of plasma virus isolates generated from subjects acutely infected with HIV-1 and molecularly cloned founder HIV-1 strains could be reduced but not fully suppressed by type 1 IFNs in vitro. The mean IC50 value for IFNα2 (22 U/ml) was lower than that for IFNβ (346 U/ml), although at maximally-inhibitory concentrations both IFN subtypes inhibited virus replication to similar extents. Individual virus isolates exhibited differential susceptibility to inhibition by IFNα2 and IFNβ, likely reflecting variation in resistance to differentially up-regulated IFN-stimulated genes. Virus isolates from subjects acutely infected with HIV-1 were significantly more resistant to in vitro control by IFNα than virus isolates generated from the same individuals during chronic, asymptomatic infection. Viral IFN resistance declined rapidly after the acute phase of infection: in five subjects, viruses derived from six-month consensus molecular clones were significantly more sensitive to the antiviral effects of IFNs than the corresponding founder viruses. The establishment of systemic HIV-1 infection by relatively IFN

  3. Max Planck-Founder of Quantum Theory

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 2. Max Planck - Founder of Quantum Theory. N Mukunda. Article-in-a-Box Volume 13 Issue 2 February 2008 pp 103-105. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/013/02/0103-0105 ...

  4. Effect of random charge fluctuation on strongly coupled dusty Plasma

    Science.gov (United States)

    Issaad, M.; Rouiguia, L.; Djebli, M.

    2008-09-01

    Modeling the interaction between particles is an open issue in dusty plasma. We dealt with strongly coupled dust particles in two dimensional confined system. For small number of clusters, we investigate the effect of random charge fluctuation on background configuration. The study is conducted for a short rang as well as a long rang potential interaction. Numerical simulation is performed using Monte-Carlo simulation in the presence of parabolic confinement and at low temperature. We have studied the background configurations for a dust particles with constant charge and in the presence of random charge fluctuation due to the discrete nature of charge carriers. The latter is studied for a positively charged dust when the dominant charging process is due to photo-emission from the dust surface. It is found, for small classical cluster consisting of small number of particles, short rang potential gives the same result as long rang one. It is also found that the random charge fluctuation affect the background configurations.

  5. Founder mutations in Tunisia: implications for diagnosis in North Africa and Middle East

    Science.gov (United States)

    2012-01-01

    Background Tunisia is a North African country of 10 million inhabitants. The native background population is Berber. However, throughout its history, Tunisia has been the site of invasions and migratory waves of allogenic populations and ethnic groups such as Phoenicians, Romans, Vandals, Arabs, Ottomans and French. Like neighbouring and Middle Eastern countries, the Tunisian population shows a relatively high rate of consanguinity and endogamy that favor expression of recessive genetic disorders at relatively high rates. Many factors could contribute to the recurrence of monogenic morbid trait expression. Among them, founder mutations that arise in one ancestral individual and diffuse through generations in isolated communities. Method We report here on founder mutations in the Tunisian population by a systematic review of all available data from PubMed, other sources of the scientific literature as well as unpublished data from our research laboratory. Results We identified two different classes of founder mutations. The first includes founder mutations so far reported only among Tunisians that are responsible for 30 genetic diseases. The second group represents founder haplotypes described in 51 inherited conditions that occur among Tunisians and are also shared with other North African and Middle Eastern countries. Several heavily disabilitating diseases are caused by recessive founder mutations. They include, among others, neuromuscular diseases such as congenital muscular dystrophy and spastic paraglegia and also severe genodermatoses such as dystrophic epidermolysis bullosa and xeroderma pigmentosa. Conclusion This report provides informations on founder mutations for 73 genetic diseases either specific to Tunisians or shared by other populations. Taking into account the relatively high number and frequency of genetic diseases in the region and the limited resources, screening for these founder mutations should provide a rapid and cost effective tool for

  6. Mediterranean Founder Mutation Database (MFMD): Taking Advantage from Founder Mutations in Genetics Diagnosis, Genetic Diversity and Migration History of the Mediterranean Population.

    Science.gov (United States)

    Charoute, Hicham; Bakhchane, Amina; Benrahma, Houda; Romdhane, Lilia; Gabi, Khalid; Rouba, Hassan; Fakiri, Malika; Abdelhak, Sonia; Lenaers, Guy; Barakat, Abdelhamid

    2015-11-01

    The Mediterranean basin has been the theater of migration crossroads followed by settlement of several societies and cultures in prehistoric and historical times, with important consequences on genetic and genomic determinisms. Here, we present the Mediterranean Founder Mutation Database (MFMD), established to offer web-based access to founder mutation information in the Mediterranean population. Mutation data were collected from the literature and other online resources and systematically reviewed and assembled into this database. The information provided for each founder mutation includes DNA change, amino-acid change, mutation type and mutation effect, as well as mutation frequency and coalescence time when available. Currently, the database contains 383 founder mutations found in 210 genes related to 219 diseases. We believe that MFMD will help scientists and physicians to design more rapid and less expensive genetic diagnostic tests. Moreover, the coalescence time of founder mutations gives an overview about the migration history of the Mediterranean population. MFMD can be publicly accessed from http://mfmd.pasteur.ma. © 2015 WILEY PERIODICALS, INC.

  7. Certain relativistic effects due to strong electromagnetic fields in plasmas

    International Nuclear Information System (INIS)

    Tsintsadze, N.L.

    1974-01-01

    It is shown that the propagation of a strong electromagnetic wave in an electron plasma can lead to a generation of a constant electron current along the direction of propagation and to a large increase in the average electron density. (Auth.)

  8. Evolutionary History of the Live-Bearing Endemic Allotoca diazi Species Complex (Actinopterygii, Goodeinae): Evidence of Founder Effect Events in the Mexican Pre-Hispanic Period

    OpenAIRE

    Corona-Santiago, Diushi Keri; Doadrio, Ignacio; Dom?nguez-Dom?nguez, Omar

    2015-01-01

    The evolutionary history of Mexican ichthyofauna has been strongly linked to natural events, and the impact of pre-Hispanic cultures is little known. The live-bearing fish species Allotoca diazi, Allotoca meeki and Allotoca catarinae occur in areas of biological, cultural and economic importance in central Mexico: Pátzcuaro basin, Zirahuén basin, and the Cupatitzio River, respectively. The species are closely related genetically and morphologically, and hypotheses have attempted to explain th...

  9. New Firm Performance and the Replacement of Founder-CEOs

    DEFF Research Database (Denmark)

    Chen, Jing; Thompson, Peter

    2015-01-01

    We study the causes and consequences of the replacement of founder-CEOs in a sample of 4,172 Danish start-ups. We propose that founder-CEO replacement is driven in part by mismatches between business quality and founder ability. Our framework suggests that replacements are more likely among...... the worst- and best-performing firms, with low (high)-ability founders replaced by manager with higher (lower) ability. Replacement is not unambiguously associated with better subsequent performance. Firms that replaced the founder were much more likely to fail, but the surviving firms among them grew...

  10. Effective Field Theories and Strong Interactions. Final Technical Report

    International Nuclear Information System (INIS)

    Fleming, Sean

    2011-01-01

    The framework of Effective Field Theories (EFTs) allows us to describe strong interactions in terms of degrees of freedom relevant to the energy regimes of interest, in the most general way consistent with the symmetries of QCD. Observables are expanded systematically in powers of M lo /M hi , where M lo (M hi ) denotes a low-(high-)energy scale. This organizational principle is referred to as 'power counting'. Terms of increasing powers in the expansion parameter are referred to as leading order (LO), next-to-leading order (NLO), etc. Details of the QCD dynamics not included explicitly are encoded in interaction parameters, or 'low-energy constants' (LECs), which can in principle be calculated from an explicit solution of QCD - for example via lattice simulations- but can also be determined directly from experimental data. QCD has an intrinsic scale M QCD ≅ 1 GeV, at which the QCD coupling constant α s (M QCD ) becomes large and the dynamics becomes non-perturbative. As a consequence M QCD sets the scale for the masses of most hadrons, such as the nucleon mass m N ≅ 940 MeV. EFTs can roughly be divided into two categories: those that can be matched onto QCD in perturbation theory, which we call high-energy EFTs, and those that cannot be matched perturbatively, which we call low-energy EFTs. In high-energy EFTs, M QCD typically sets the low-energy scale, and all the dynamics associated with this scale reside in matrix elements of EFT operators. These non-perturbative matrix elements are the LECs and are also referred to as long-distance contributions. Each matrix element is multiplied by a short-distance coefficient, which contains the dynamics from the high scale M hi . Since M hi >> M QCD , α s (M hi ) hi ∼ M Q , the heavy-quark mass, and in addition to M QCD there are low scales associated with the typical relative momentum ∼ M Q v and energy ∼ M Q v 2 of the heavy quarks. Depending on the sizes of M Q and the heavy-quark velocity v these scales can

  11. How strong and generalisable is the Generation Y effect?

    DEFF Research Database (Denmark)

    Mueller, Simone; Remaud, Hervé; Chabin, Yann

    2011-01-01

    alcoholic beverage consumption. A number of noticeable differences appeared between countries: wine involvement and consumption increases with age in traditional European wine markets, while they decrease in North America; environmental concerns and purchase channel usage hardly differ between generations......Purpose – This study aims to investigate how strongly Generation Y consumers differ in their values, attitudes and wine and alcoholic beverage consumption behaviour from older generations. The comparison spans seven culturally different markets. Design/methodology/approach – Large representative...

  12. Genome-wide association studies in an isolated founder population from the Pacific Island of Kosrae.

    Directory of Open Access Journals (Sweden)

    Jennifer K Lowe

    2009-02-01

    Full Text Available It has been argued that the limited genetic diversity and reduced allelic heterogeneity observed in isolated founder populations facilitates discovery of loci contributing to both Mendelian and complex disease. A strong founder effect, severe isolation, and substantial inbreeding have dramatically reduced genetic diversity in natives from the island of Kosrae, Federated States of Micronesia, who exhibit a high prevalence of obesity and other metabolic disorders. We hypothesized that genetic drift and possibly natural selection on Kosrae might have increased the frequency of previously rare genetic variants with relatively large effects, making these alleles readily detectable in genome-wide association analysis. However, mapping in large, inbred cohorts introduces analytic challenges, as extensive relatedness between subjects violates the assumptions of independence upon which traditional association test statistics are based. We performed genome-wide association analysis for 15 quantitative traits in 2,906 members of the Kosrae population, using novel approaches to manage the extreme relatedness in the sample. As positive controls, we observe association to known loci for plasma cholesterol, triglycerides, and C-reactive protein and to a compelling candidate loci for thyroid stimulating hormone and fasting plasma glucose. We show that our study is well powered to detect common alleles explaining >/=5% phenotypic variance. However, no such large effects were observed with genome-wide significance, arguing that even in such a severely inbred population, common alleles typically have modest effects. Finally, we show that a majority of common variants discovered in Caucasians have indistinguishable effect sizes on Kosrae, despite the major differences in population genetics and environment.

  13. Spin effects in strong-field laser-electron interactions

    International Nuclear Information System (INIS)

    Ahrens, S; Bauke, H; Müller, T-O; Villalba-Chávez, S; Müller, C

    2013-01-01

    The electron spin degree of freedom can play a significant role in relativistic scattering processes involving intense laser fields. In this contribution we discuss the influence of the electron spin on (i) Kapitza-Dirac scattering in an x-ray laser field of high intensity, (ii) photo-induced electron-positron pair production in a strong laser wave and (iii) multiphoton electron-positron pair production on an atomic nucleus. We show that in all cases under consideration the electron spin can have a characteristic impact on the process properties and their total probabilities. To this end, spin-resolved calculations based on the Dirac equation in the presence of an intense laser field are performed. The predictions from Dirac theory are also compared with the corresponding results from the Klein-Gordon equation.

  14. Native American admixture in the Quebec founder population.

    Directory of Open Access Journals (Sweden)

    Claudia Moreau

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

  15. Radiation effects on relativistic electrons in strong external fields

    International Nuclear Information System (INIS)

    Iqbal, Khalid

    2013-01-01

    The effects of radiation of high energy electron beams are a major issue in almost all types of charged particle accelerators. The objective of this thesis is both the analytical and numerical study of radiation effects. Due to its many applications the study of the self force has become a very active and productive field of research. The main part of this thesis is devoted to the study of radiation effects in laser-based plasma accelerators. Analytical models predict the existence of radiation effects. The investigation of radiation reaction show that in laser-based plasma accelerators, the self force effects lower the energy gain and emittance for moderate energies electron beams and increase the relative energy spread. However, for relatively high energy electron beams, the self radiation and retardation (radiation effects of one electron on the other electron of the system) effects increase the transverse emittance of the beam. The energy gain decreases to even lower value and relative energy spread increases to even higher value due to high radiation losses. The second part of this thesis investigates with radiation reaction in focused laser beams. Radiation effects are very weak even for high energy electrons. The radiation-free acceleration and the simple practical setup make direct acceleration in a focused laser beam very attractive. The results presented in this thesis can be helpful for the optimization of future electron acceleration experiments, in particular in the case of laser-plasma accelerators.

  16. Effective magnetic moment of neutrinos in strong magnetic fields

    CERN Document Server

    Pérez, A; Masood, S S; Gaitan, R; Rodríguez, S

    2002-01-01

    In this paper we compute the effective magnetic moment of neutrinos propagating in dense high magnetized medium. Taking typical values of magnetic field and densities of astrophysical objects (such as the cores of supernovae and neutron stars) we obtain an effective type of dipole magnetic moment in agreement with astrophysical and cosmological bounds. (Author)

  17. The Connect Effect Building Strong Personal, Professional, and Virtual Networks

    CERN Document Server

    Dulworth, Michael

    2008-01-01

    Entrepreneur and executive development expert Mike Dulworth's THE CONNECT EFFECT provides readers with a simple framework and practical tools for developing that crucial competitive advantage: a high-quality personal, professional/organizational and virtual network.

  18. Effective bounds on strong unicity in L1-approximation

    DEFF Research Database (Denmark)

    Kohlenbach, Ulrich; Oliva, Paulo B.

    In this paper we present another case study in the general project of Proof Mining which means the logical analysis of prima facie non-effective proofs with the aim of extracting new computationally relevant data. We use techniques based on monotone functional interpretation (developed in [17]) t...

  19. Strong delayed interactive effects of metal exposure and warming

    DEFF Research Database (Denmark)

    Debecker, Sara; Dinh, Khuong Van; Stoks, Robby

    2017-01-01

    As contaminants are often more toxic at higher temperatures, predicting their impact under global warming remains a key challenge for ecological risk assessment. Ignoring delayed effects, synergistic interactions between contaminants and warming, and differences in sensitivity across species......’ ranges could lead to an important underestimation of the risks. We addressed all three mechanisms by studying effects of larval exposure to zinc and warming before, during, and after metamorphosis in Ischnura elegans damselflies from high- and lowlatitude populations. By integrating these mechanisms...... was especially remarkable in high-latitude animals, as they appeared almost insensitive to zinc during the larval stage. Second, the well-known synergism between metals and warming was manifested not only during the larval stage but also after metamorphosis, yet notably only in low-latitude damselflies...

  20. Effect of strong fragrance on olfactory detection threshold.

    Science.gov (United States)

    Fasunla, Ayotunde James; Douglas, David Dayo; Adeosun, Aderemi Adeleke; Steinbach, Silke; Nwaorgu, Onyekwere George Benjamin

    2014-09-01

    To assess the olfactory threshold of healthy volunteers at the University College Hospital, Ibadan and to investigate the effect of perfume on their olfactory detection thresholds. A quasi-experimental study on olfactory detection thresholds of healthy volunteers from September 2013 to November 2013. Tertiary health institution. A structured questionniare was administered to the participants in order to obtain information on sociodemographics, occupation, ability to perceive smell, use of perfume, effects of perfume on appetite and self-confidence, history of allergy, and previous nasal surgery. Participants subjectively rated their olfactory performance. Subsequently, they had olfactory detection threshold testing done at baseline and after exposure to perfume with varied concentrations of n-butanol in a forced triple response and staircase fashion. Healthy volunteers, 37 males and 63 females, were evaluated. Their ages ranged from 19 to 59 years with a mean of 31 years ± 8. Subjectively, 94% of the participants had excellent olfactory function. In the pre-exposure forced triple response, 88% were able to detect the odor at ≤.25 mmol/l concentration while in the post-exposure forced triple response, only 66% were able to detect the odor at ≤.25 mmol/l concentration. There is also a statistical significant difference in the olfactory detection threshold score between the pre-exposure and post-exposure period in the participants (P fragrances affects the olfactory detection threshold. Therefore patients and clinicians should be aware of this and its effects on the outcome of test of olfaction. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

  1. Stirling engines using working fluids with strong real gas effects

    International Nuclear Information System (INIS)

    Invernizzi, Costante M.

    2010-01-01

    Real gas effects typical of the critical region of working fluids are a powerful tool to increase the energy performances of Stirling cycles, mainly at low top temperatures. To carry out the compression near the critical region the working fluids must have a critical temperature near environmental conditions and the use of organic working substances (pure or in suitable mixtures) as a matter of fact begins compulsory. The moderate thermal stability of the organic working fluids limits the maximum temperatures to 300-400 deg. C and as a consequence, the achievable cycles efficiencies result rather low. Carbon dioxide, with a critical temperature of 31 deg. C, is, among the traditionally inorganic gases, an exception and is considered here in comparison with organic substances. But the good thermodynamics of the cycles allows, in the considered cases, conversion efficiencies of about 20%, with good specific powers. The good energy performance of real gas Stirling cycles is obtained at the cost of high maximum cycle pressure, in the range of at least 100-300 bar. These high pressures nevertheless have large positive effects on the heat power transferred per unit of pumping mechanical power, and the low top temperatures have a positive influence on the material problems for the hottest engine parts.

  2. BRCA1/BRCA2 founder mutations and cancer risks

    DEFF Research Database (Denmark)

    Nielsen, Henriette Roed; Nilbert, Mef; Petersen, Janne

    2016-01-01

    Mutations in the BRCA1 and BRCA2 genes significantly contribute to hereditary breast cancer and ovarian cancer, but the phenotypic effect from different mutations is insufficiently recognized. We used a western Danish clinic-based cohort of 299 BRCA families to study the female cancer risk...... in mutation carriers and their untested first-degree relatives. Founder mutations were characterized and the risk of cancer was assessed in relation to the specific mutations. In BRCA1, the cumulative cancer risk at age 70 was 35 % for breast cancer and 29 % for ovarian cancer. In BRCA2, the cumulative risk...... was 44 % for breast cancer and 15 % for ovarian cancer. We identified 47 distinct BRCA1 mutations and 48 distinct mutations in BRCA2. Among these, 8 founder mutations [BRCA1 c.81-?_4986+?del, c.3319G>T (p.Glu1107*), c.3874delT and c.5213G>A (p.Gly1738Glu) and BRCA2 c.6373delA, c.7008-1G>A, c.7617+1G...

  3. Strong surface effect on direct bulk flexoelectric response in solids

    International Nuclear Information System (INIS)

    Yurkov, A. S.; Tagantsev, A. K.

    2016-01-01

    In the framework of a continuum theory, it is shown that the direct bulk flexoelectric response of a finite sample essentially depends on the surface polarization energy, even in the thermodynamic limit where the body size tends to infinity. It is found that a modification of the surface energy can lead to a change in the polarization response by a factor of two. The origin of the effect is an electric field produced by surface dipoles induced by the strain gradient. The unexpected sensitivity of the polarization response to the surface energy in the thermodynamic limit is conditioned by the fact that the moments of the surface dipoles may scale as the body size

  4. Corporate Social Responsibility in Large Family and Founder Firms

    NARCIS (Netherlands)

    J.H. Block (Jörn); M. Wagner (Marcus)

    2010-01-01

    textabstractBased on arguments about long-term orientation and corporate reputation, we argue that family and founder firms differ from other firms with regard to corporate social responsibility. Using Bayesian analysis, we then show that family and founder ownership are associated with a lower

  5. What Makes Entrepreneurs Happy? Determinants of Satisfaction Among Founders

    NARCIS (Netherlands)

    M.A. Carree (Martin); I. Verheul (Ingrid)

    2012-01-01

    textabstractThis study empirically investigates factors influencing satisfaction levels of founders of new ventures, using a representative sample of 1,107 Dutch founders. We relate entrepreneurial satisfaction (with income, psychological burden and leisure time) to firm performance, motivation and

  6. Haplotype study in Dutch SCA3 and SCA6 families : evidence for common founder mutations

    NARCIS (Netherlands)

    Verbeek, Dineke S; Piersma, Sytse J; Hennekam, Eric F A M; Ippel, Elly F; Pearson, Peter L; Sinke, Richard J

    This pilot study was initiated to show the existence of founder effects in the Dutch autosomal dominant cerebellar ataxia (ADCA) population. The ADCAs comprise a clinically heterogeneous group of neurodegenerative disorders and the estimated prevalence in the Netherlands is approximately 3:100 000

  7. How Lead Founder Personality Affects New Venture Performance: The Mediating Role of Team Conflict

    NARCIS (Netherlands)

    de Jong, Ad; Song, Michael; Song, Lisa Z.

    2013-01-01

    This empirical study of 323 new ventures examines how task and relationship conflict in the founding top management team mediates the effect of lead founder personality on new venture performance. The results reveal that (1) openness and agreeableness increase task conflict, whereas

  8. The impact of founder events on chromosomal variability in multiply mating species

    DEFF Research Database (Denmark)

    Pool, John E; Nielsen, Rasmus

    2008-01-01

    size reductions and recent bottlenecks leading to decreased X/A diversity ratios. Here we use theory and simulation to investigate a separate demographic effect-that of founder events involving multiply mated females-and find that it leads to much stronger reductions in X/A diversity ratios than...

  9. Characterization of founder viruses in very early SIV rectal transmission.

    Science.gov (United States)

    Yuan, Zhe; Ma, Fangrui; Demers, Andrew J; Wang, Dong; Xu, Jianqing; Lewis, Mark G; Li, Qingsheng

    2017-02-01

    A better understanding of HIV-1 transmission is critical for developing preventative strategies. To that end, we analyzed 524 full-length env sequences of SIVmac251 at 6 and 10 days post intrarectal infection of rhesus macaques. There was no tissue compartmentalization of founder viruses across plasma, rectal and distal lymphatic tissues for most animals; however one animal has evidence of virus tissue compartmentalization. Despite identical viral inoculums, founder viruses were animal-specific, primarily derived from rare variants in the inoculum, and have a founder virus signature that can distinguish dominant founder variants from minor founder or untransmitted variants in the inoculum. Importantly, the sequences of post-transmission defective viruses were phylogenetically associated with competent viral variants in the inoculum and were mainly converted from competent viral variants by frameshift rather than APOBEC mediated mutations, suggesting the converting the transmitted viruses into defective viruses through frameshift mutation is an important component of rectal transmission bottleneck. Anorectal receptive intercourse is a common route of HIV-1 transmission and a better understanding of the transmission mechanisms is critical for developing HIV-1 preventative strategies. Here, we report that there is no tissue compartmentalization of founder viruses during very early rectal transmission of SIV in the majority of rhesus macaques and founder viruses are preferentially derived from rare variant in the inoculum. We also found that founder viruses are animal-specific despite identical viral inoculums. After viruses cross the mucosal barriers, the host further reduces viral diversity by converting some of the transmitted functional viruses into defective viruses through frameshift rather than APOBEC derived mutations. To our knowledge, this is the first study of founder viruses at multiple tissue sites during very early rectal transmission. Copyright © 2016

  10. The Lublin Philosophical School: Founders, Motives, Characteristics

    Directory of Open Access Journals (Sweden)

    Mieczysław A. Krąpiec

    2015-12-01

    Full Text Available The article is focused on the Lublin Philosophical School; it explains its name, presents its founders, reveals the causes of its rise, and introduce the specific character of the School’s philosophy.It starts with stating the fact that in the proper sense, the term “Lublin Philosophical School” describes a way of cultivating realistic (classical philosophy developed in the 1950s by a group of philosophers at the Catholic University of Lublin, Poland. The Lublin Philosophical School is characterized by cognitive realism (the object of cognition is really existing being, maximalism (taking up all existentially important questions, methodological autonomy (in relation to the natural-mathematical sciences and theology, transcendentalism in its assertions (its assertions refer to all reality, methodological-epistemological unity (the same method applied in objectively cultivated philosophical disciplines, coherence (which guarantees the objective unity of the object, and objectivity (achieved by the verifiability of assertions on their own terms, which is achieved by relating them in each instance to objective evidence. The term is the name of the Polish school of realistic (classical philosophy that arose as a response to the Marxism that was imposed administratively on Polish institutions of learning, and also as a response to other philosophical currents dominant at the time such as phenomenology, existentialism, and logical positivism.

  11. Effect of strong electrolytes on edible oils part III: viscosity of canola ...

    African Journals Online (AJOL)

    Effect of strong electrolytes on the viscosity of canola oil in 1,4 dioxane was undertaken. The viscosity of oil in 1,4 dioxane was found to increase with the concentration of oil and decrease with rise in temperature. Strong electrolytes reduce the rate of flow of oil in 1,4 dioxane. It was noted that amongst these electrolytes, ...

  12. Anomalous Josephson effect in semiconductor nanowire with strong spin-orbit interaction and Zeeman effect

    Science.gov (United States)

    Yokoyama, Tomohiro; Eto, Mikio; Nazarov, Yuli

    2014-03-01

    We theoretically investigate the Josephson junction using quasi-one dimensional semiconductor nanowires with strong spin-orbit (SO) interaction, e.g., InSb. First, we examine a simple model using a single scatterer to describe the elastic scattering due to impurities and SO interaction in the normal region.[1] The Zeeman effect is taken into account by the spin-dependent phase shift of electron and hole through the system. The interplay between SO interaction and Zeeman effect results in a finite supercurrent even when the phase difference between two superconductors is zero. Moreover, the critical current depends on its current direction if more than one conduction channel is present in the nanowire. Next, we perform a numerical simulation by the tight-binding model for the nanowire to confirm our simple model. Then, we show that a spin-dependent Fermi velocity due to the SO interaction causes the anomalous Josephson effect.

  13. Founder Family Influence and Foreign Exchange Risk Management

    DEFF Research Database (Denmark)

    Aabo, Tom; Kuhn, Jochen; Zanotti, Giovanni

    2011-01-01

    , founder family firms tend not only to hedge but also to speculate more extensively than other firms. Research limitations/implications The findings are based on medium-sized, manufacturing firms in Denmark. Originality/value This study provides empirical evidence on the influence of founder families......Purpose    The purpose of this study is to explore the influence of founder families in medium-sized, manufacturing firms and to investigate the impact of such influence on risk management - more specifically foreign exchange hedging and speculation. Design/methodology/approach This empirical study...... in medium-sized firms (as opposed to large, listed firms in most other studies) and adds to the sparse literature on the impact of founder family influence on risk management.  ...

  14. Founders at work stories of startups'' early days

    CERN Document Server

    Livingston, Jessica

    2008-01-01

    Livingston presents a collection of interviews with founders of famous technology companies about what happens in the very earliest days. Includes interviews with Steve Wozniak (Apple), Max Levchin (PayPal), and others.

  15. Strong Effect of Azodye Layer Thickness on RM-Stabilized Photoalignment

    Science.gov (United States)

    2017-05-21

    Strong Effect of Azodye Layer Thickness on RM-Stabilized Photoalignment Colin McGinty*, Valerie Finnemeyer**, Robert Reich**, Harry Clark...vertical alignment on these substrates. For the thinner BY layers, we do not see this strong evidence of out of plane reorientation. The out of...In this report we show the surprising effect that thin azodye layers demonstrate improved stability over those that are thicker. Figure 6

  16. Nontrivial effects of high-frequency excitation for strongly damped mechanical systems

    DEFF Research Database (Denmark)

    Fidlin, Alexander; Thomsen, Jon Juel

    Some nontrivial effects are investigated, which can occur if strongly damped mechanical systems are subjected to strong high-frequency (HF) excitation. The main result is a theoretical prediction, supported by numerical simulation, that for such systems the (quasi-)equilibrium states can change...... that can be substantial (depending on the strength of the HF excitation) for finite values of the damping. The analysis is focused on the differences between the classic results for weakly damped systems, and new effects for which the strong damping terms are responsible. The analysis is based...... on a slightly modified averaging technique, and includes an elementary example of an elliptically excited pendulum for illustration, alongside with a generalization to a broader class of strongly damped dynamical systems with HF excitation. As an application example, the nontrivial behavior of a classical...

  17. Nontrivial effects of high-frequency excitation for strongly damped mechanical systems

    DEFF Research Database (Denmark)

    Fidlin, Alexander; Thomsen, Jon Juel

    2008-01-01

    Some non-trivial effects are investigated, which can occur if strongly damped mechanical systems are subjected to strong high-frequency (HF) excitation. The main result is a theoretical prediction, supported by numerical simulation, that for such systems the (quasi-)equilibrium states can change...... that can be substantial depending on the strength of the HF excitation) for finite values of the damping. The analysis is focused on the differences between the classic results for weakly damped systems, and new effects for which the strong damping terms are responsible. The analysis is based on a slightly...... modified averaging technique, and includes an elementary example of an elliptically excited pendulum for illustration, alongside with a generalization to a broader class of strongly damped dynamical systems with HF excitation. As an application example, the nontrivial behavior of a classical optimally...

  18. <strong>Effectiveness of Orthoses and Foot Training in patients with Patellofemoral Pain and hyperpronationstrong>

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kaalund, Søren; Christensen, Marianne

    of treatment with functional foot orthoses, exercises, or orthoses with exercises. The intrinsic pedal muscles play an important role in support of the medial longitudinal arch. (2) There are however very little information of the effect from specific foot exercise as an imperative part of exercise program...... adolescent females (3). Soft foot orhtoses in addition to an exercise program resulted in significantly greater improvements in pain than treatment with flat insoles and exercises over eight weeks. A study from 2004 by Wiener-Ogilvie & Jones (4) found however no difference in outcome between 8 weeks...... to PFPS patients. The purpose of this prospective single blinded randomised study was to determine the effectiveness of a standardized foot training program combined with foot orthoses in patients with patellofemoral pain. This treatment was additional to a regular conservative patellofemoral regime...

  19. Computing effective properties of nonlinear structures exposed to strong high-frequency loading at multiple frequencies

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2006-01-01

    Effects of strong high-frequency excitation at multiple frequencies (multi-HFE) are analyzed for a class of generally nonlinear systems. The effects are illustrated for a simple pendulum system with a vibrating support, and for a parametrically excited flexible beam. For the latter, theoretical...

  20. SUNYAEV-ZEL'DOVICH EFFECT OBSERVATIONS OF STRONG LENSING GALAXY CLUSTERS: PROBING THE OVERCONCENTRATION PROBLEM

    International Nuclear Information System (INIS)

    Gralla, Megan B.; Gladders, Michael D.; Marrone, Daniel P.; Bayliss, Matthew; Carlstrom, John E.; Greer, Christopher; Hennessy, Ryan; Koester, Benjamin; Leitch, Erik; Sharon, Keren; Barrientos, L. Felipe; Bonamente, Massimiliano; Bulbul, Esra; Hasler, Nicole; Culverhouse, Thomas; Hawkins, David; Lamb, James; Gilbank, David G.; Joy, Marshall; Miller, Amber

    2011-01-01

    We have measured the Sunyaev-Zel'dovich (SZ) effect for a sample of 10 strong lensing selected galaxy clusters using the Sunyaev-Zel'dovich Array (SZA). The SZA is sensitive to structures on spatial scales of a few arcminutes, while the strong lensing mass modeling constrains the mass at small scales (typically <30''). Combining the two provides information about the projected concentrations of the strong lensing clusters. The Einstein radii we measure are twice as large as expected given the masses inferred from SZ scaling relations. A Monte Carlo simulation indicates that a sample randomly drawn from the expected distribution would have a larger median Einstein radius than the observed clusters about 3% of the time. The implied overconcentration has been noted in previous studies and persists for this sample, even when we take into account that we are selecting large Einstein radius systems, suggesting that the theoretical models still do not fully describe the observed properties of strong lensing clusters.

  1. Using strong nonlinearity and high-frequency vibrations to control effective properties of discrete elastic waveguides

    DEFF Research Database (Denmark)

    Lazarov, Boyan Stefanov; Thomsen, Jon Juel; Snaeland, Sveinn Orri

    2008-01-01

    The aim of this article is to investigate how highfrequency (HF) excitation, combined with strong nonlinear elastic material behavior, influences the effective material or structural properties for low-frequency excitation and wave propagation. The HF effects are demonstrated on discrete linear...... spring-mass chains with non-linear inclusions. The presented analytical and numerical results suggest that the effective material properties can easily be altered by establishing finite amplitude HF standing waves in the non-linear regions of the chain....

  2. Effective hadronic lagrangian in the strong coupling expansion of lattice QCD with Susskind fermions

    International Nuclear Information System (INIS)

    Azakov, S.I.; Aliev, E.S.

    1987-12-01

    The effective hadronic action in lattice QCD with U(N) and SU(N) gauge groups and with Susskind fermions is constructed in the framework of the strong coupling approximation. For arbitrary finite (odd) N (in particular N=3) we find an effective potential, vacuum expectation value of the (χ-barχ) and an effective action for the physical meson field π(x). (author). 19 refs

  3. Planning, Instruction, and Assessment: Effective Teaching Practices. James H. Stronge Research-to-Practice Series

    Science.gov (United States)

    Grant, Leslie W.; Hindman, Jennifer; Stronge, James H.

    2010-01-01

    This entry in the James H. Stronge Research-to-Practice Series focuses on specific strategies teachers can use to improve the quality of their instruction. Studies have shown teacher quality to be the top indicator of student achievement, with the effects of good teachers apparent even as students move on to successive grades. In this book, Grant,…

  4. Engineering the Dynamics of Effective Spin-Chain Models for Strongly Interacting Atomic Gases

    DEFF Research Database (Denmark)

    Volosniev, A. G.; Petrosyan, D.; Valiente, M.

    2015-01-01

    We consider a one-dimensional gas of cold atoms with strong contact interactions and construct an effective spin-chain Hamiltonian for a two-component system. The resulting Heisenberg spin model can be engineered by manipulating the shape of the external confining potential of the atomic gas. We...

  5. Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela

    2018-01-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calculate...

  6. Parity violation effects in the hydrogen atom in the field of a strong electromagnetic wave

    International Nuclear Information System (INIS)

    Labzovsky, L.N.; Mitrushchenkov, A.O.

    1989-01-01

    The parity violation effects in the hydrogen atom in a strong electromagnetic laser field are considered. It is shown that there is the possibility of hyperrate measurements of different constants of the weak interaction in the hydrogen magnetic resonance experiments. (orig.)

  7. Effects of interaction imbalance in a strongly repulsive one-dimensional Bose gas

    DEFF Research Database (Denmark)

    Barfknecht, Rafael Emilio; Zinner, Nikolaj Thomas; Foerster, Angela

    2018-01-01

    We calculate the spatial distributions and the dynamics of a few-body two-component strongly interacting Bose gas confined to an effectively one-dimensional trapping potential. We describe the densities for each component in the trap for different interaction and population imbalances. We calcula...

  8. Non-Oberbeck-Boussinesq effects in strongly turbulent Rayleigh-Bénard convection

    NARCIS (Netherlands)

    Ahlers, Günter; Brown, Eric; Fontenele Araujo Junior, F.; Funfschilling, Denis; Grossmann, Siegfried; Lohse, Detlef

    2006-01-01

    Non-Oberbeck–Boussinesq (NOB) effects on the Nusselt number $Nu$ and Reynolds number $\\hbox{\\it Re}$ in strongly turbulent Rayleigh–Bénard (RB) convection in liquids were investigated both experimentally and theoretically. In the experiments the heat current, the temperature difference, and the

  9. Heavy quark mass effects and improved tests of the flavor independence of strong interactions

    Energy Technology Data Exchange (ETDEWEB)

    Burrows, P.N. [Univ. of Oxford (United Kingdom); SLD Collaboration

    1998-08-01

    A review is given of latest results on tests of the flavor independence of strong interactions. Heavy quark mass effects are evident in the data and are now taken into account at next-to-leading order in QCD perturbation theory. The strong-coupling ratios {alpha}{sub s}{sup b}/{alpha}{sub s}{sup uds} and {alpha}{sub s}{sup c}/{alpha}{sub s}{sup uds} are found to be consistent with unity. Determinations of the b-quark mass m{sub b} (M{sub Z}) are discussed.

  10. Strong interaction effects in high-Z K sup minus atoms

    Energy Technology Data Exchange (ETDEWEB)

    Batty, C.J.; Eckhause, M.; Gall, K.P.; Guss, P.P.; Hertzog, D.W.; Kane, J.R.; Kunselman, A.R.; Miller, J.P.; O' Brien, F.; Phillips, W.C.; Powers, R.J.; Roberts, B.L.; Sutton, R.B.; Vulcan, W.F.; Welsh, R.E.; Whyley, R.J.; Winter, R.G. (Rutherford-Appleton Laboratory, Chilton, Didcot OX11 0QX, United Kingdom (GB) College of William and Mary, Williamsburg, Virginia 23185 Boston University, Boston, Massachusetts 02215 University of Wyoming, Laramie, Wyoming 82071 California Institute of Technology, Pasadena, California 91125 Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213)

    1989-11-01

    A systematic experimental study of strong interaction shifts, widths, and yields from high-{ital Z} kaonic atoms is reported. Strong interaction effects for the {ital K}{sup {minus}}(8{r arrow}7) transition were measured in U, Pb, and W, and the {ital K}{sup {minus}}(7{r arrow}6) transition in W was also observed. This is the first observation of two measurably broadened and shifted kaonic transitions in a single target and thus permitted the width of the upper state to be determined directly, rather than being inferred from yield data. The results are compared with optical-model calculations.

  11. Auger effect in the presence of strong x-ray pulses

    International Nuclear Information System (INIS)

    Liu Jicai; Sun Yuping; Wang Chuankui; Aagren, Hans; Gel'mukhanov, Faris

    2010-01-01

    We study the role of propagation of strong x-ray free-electron laser pulses on the Auger effect. When the system is exposed to a strong x-ray pulse the stimulated emission starts to compete with the Auger decay. As an illustration we present numerical results for Ar gas with the frequency of the incident x-ray pulse tuned in the 2p 3/2 -4s resonance. It is shown that the pulse propagation is accompanied by two channels of amplified spontaneous emission, 4s-2p 3/2 and 3s-2p 3/2 , which reshape the pulse when the system is inverted. The population inversion is quenched for longer propagation distances where lasing without inversion enhances the Stokes component. The results of simulations show that the propagation of the strong x-ray pulses affect intensively the Auger branching ratio.

  12. MSR Founders Narrative and Content Analysis of Scholarly Papers

    DEFF Research Database (Denmark)

    Tackney, Charles T.; Chappell, Stacie F.; Sato, Toyoko

    2017-01-01

    the Interest Group. The founders interviewed were identified through preliminary inquiry and from archival sources. As complement and extension, we concurrently conducted a content analysis of the 15 years of MSR Best Papers and Carolyn Dexter Award MSR nominated papers for Academy internationalization...... of spirituality in management practices that infuse MSR with its enduring organizational vitality....

  13. Utilization of founder lines for improved Citrus biotechnology via RMCE

    Science.gov (United States)

    On October 1st 2011 the CRB chose to fund a unique research project, the development of citrus cultivars specifically for genetic engineering (GE). The objective of this research was to develop GE citrus ‘Founder Lines’ containing DNA sequences that will allow the precise insertion of genes for de...

  14. Founders of share companies under the Ethiopian share company ...

    African Journals Online (AJOL)

    This article explores the Commercial Code and other laws of Ethiopia regarding founders – who they are, liabilities and benefits - who are also called 'promoters' by many other company laws. To some extent, it also looks into the business practice based on documents like memorandum of associations, articles of ...

  15. Strong coupling electrostatics for randomly charged surfaces: antifragility and effective interactions.

    Science.gov (United States)

    Ghodrat, Malihe; Naji, Ali; Komaie-Moghaddam, Haniyeh; Podgornik, Rudolf

    2015-05-07

    We study the effective interaction mediated by strongly coupled Coulomb fluids between dielectric surfaces carrying quenched, random monopolar charges with equal mean and variance, both when the Coulomb fluid consists only of mobile multivalent counterions and when it consists of an asymmetric ionic mixture containing multivalent and monovalent (salt) ions in equilibrium with an aqueous bulk reservoir. We analyze the consequences that follow from the interplay between surface charge disorder, dielectric and salt image effects, and the strong electrostatic coupling that results from multivalent counterions on the distribution of these ions and the effective interaction pressure they mediate between the surfaces. In a dielectrically homogeneous system, we show that the multivalent counterions are attracted towards the surfaces with a singular, disorder-induced potential that diverges logarithmically on approach to the surfaces, creating a singular but integrable counterion density profile that exhibits an algebraic divergence at the surfaces with an exponent that depends on the surface charge (disorder) variance. This effect drives the system towards a state of lower thermal 'disorder', one that can be described by a renormalized temperature, exhibiting thus a remarkable antifragility. In the presence of an interfacial dielectric discontinuity, the singular behavior of counterion density at the surfaces is removed but multivalent counterions are still accumulated much more strongly close to randomly charged surfaces as compared with uniformly charged ones. The interaction pressure acting on the surfaces displays in general a highly non-monotonic behavior as a function of the inter-surface separation with a prominent regime of attraction at small to intermediate separations. This attraction is caused directly by the combined effects from charge disorder and strong coupling electrostatics of multivalent counterions, which dominate the surface-surface repulsion due to

  16. Empty creditors and strong shareholders: The real effects of credit risk trading. Second draft

    OpenAIRE

    Colonnello, Stefano; Efing, Matthias; Zucchi, Francesca

    2016-01-01

    Credit derivatives give creditors the possibility to transfer debt cash flow rights to other market participants while retaining control rights. We use the market for credit default swaps (CDSs) as a laboratory to show that the real effects of such debt unbundling crucially hinge on shareholder bargaining power. We find that creditors buy more CDS protection when facing strong shareholders to secure themselves a valuable outside option in distressed renegotiations. After the start of CDS trad...

  17. [Effects of strong reductive approach on remediation of degraded facility vegetable soil].

    Science.gov (United States)

    Zhu, Tong-Bin; Meng, Tian-Zhu; Zhang, Jin-Bo; Cai, Zu-Cong

    2013-09-01

    High application rate of chemical fertilizers and unreasonable rotation in facility vegetable cultivation can easily induce the occurrence of soil acidification, salinization, and serious soil-borne diseases, while to quickly and effectively remediate the degraded facility vegetable soil can considerably increase vegetable yield and farmers' income. In this paper, a degraded facility vegetable soil was amended with 0, 3.75, 7.50, and 11.3 t C x hm(-2) of air-dried alfalfa and flooded for 31 days to establish a strong reductive environment, with the variations of soil physical and chemical properties and the cucumber yield studied. Under the reductive condition, soil Eh dropped quickly below 0 mV, accumulated soil NO3(-) was effectively eliminated, soil pH was significantly raised, and soil EC was lowered, being more evident in higher alfalfa input treatments. After treated with the strong reductive approach, the cucumber yield in the facility vegetable field reached 53.3-57.9 t x hm(-2), being significantly higher than that in un-treated facility vegetable field in last growth season (10.8 t x hm(-2)). It was suggested that strong reductive approach could effectively remediate the degraded facility vegetable soil in a short term.

  18. THE INFLUENCE OF THE COMPETENCES OF THE MANAGER: FOUNDER ON THE SUCCESS OF THE ORGANIZATION

    Directory of Open Access Journals (Sweden)

    Ace Milenkovski

    2013-06-01

    Full Text Available The environment, where the changes are everyday occurrence and the competition continuous threat, forces the leading people in the organizations to look after everything that goes on inside the organizations, as well as everything that goes on outside of them. Thus, depending on the founder’s capability, respectively the manager of the organization, the success of the organization can go up or down. The individuals that have entrepreneurial spirit, that know how to combine their knowledge, education and work experience with the successful guiding of the employees toward the goal, strengthen their business and open possibilities for its expansion.If under competence we imply to the knowledge of business, working experience and skills necessary for effective performance at the workplace, then undoubtedly the entrepreneur–founder in order to obtain the optimum knowledge for the business that he starts, previously has to build his competences through appropriate education and work experience.Herein we present working research conducted in order to prove the connection of the organization’s success with the knowledge, skills and competences for the corresponding business of the organization’s founder, particularly if the founder is also general manager of the organization. This research is conducted within the frames of the scientific and research activity of the University of Tourism and Management in Skopje, FYRO Macedonia.As a research sample 271 respondents – employees and 10 leaders of the companies included in the research. The leaders are managers and founders of the private companies. As a research technique questionnaire is used. Practical aim of the research was to use the results in order to create a basis for improving the performance of companies by developing the competencies of the management teams in them. One of the main conclusions of the research is: The manager-founder who starts up a business, needs to have optimum

  19. Re-evaluation of the macroseismic effects produced by the March 4, 1977, strong Vrancea earthquake in Romanian territory

    Directory of Open Access Journals (Sweden)

    Aurelian Pantea

    2013-04-01

    Full Text Available In this paper, the macroseismic effects of the subcrustal earthquake in Vrancea (Romania that occurred on March 4, 1977, have been re-evaluated. This was the second strongest seismic event that occurred in this area during the twentieth century, following the event that happened on November 10, 1940. It is thus of importance for our understanding of the seismicity of the Vrancea zone. The earthquake was felt over a large area, which included the territories of the neighboring states, and it produced major damage. Due to its effects, macroseismic studies were developed by Romanian researchers soon after its occurrence, with foreign scientists also involved, such as Medvedev, the founder of the Medvedev-Sponheuer-Karnik (MSK seismic intensity scale. The original macroseismic questionnaires were re-examined, to take into account the recommendations for intensity assessments according to the MSK-64 macroseismic scale used in Romania. After the re-evaluation of the macroseismic field of this earthquake, the intensity dataset was obtained for 1,620 sites in Romanian territory. The re-evaluation was necessary as it has confirmed that the previous macroseismic map was underestimated. On this new map, only the intensity data points are plotted, without tracing the isoseismals.

  20. Strong Stability Preserving Explicit Runge--Kutta Methods of Maximal Effective Order

    KAUST Repository

    Hadjimichael, Yiannis

    2013-07-23

    We apply the concept of effective order to strong stability preserving (SSP) explicit Runge--Kutta methods. Relative to classical Runge--Kutta methods, methods with an effective order of accuracy are designed to satisfy a relaxed set of order conditions but yield higher order accuracy when composed with special starting and stopping methods. We show that this allows the construction of four-stage SSP methods with effective order four (such methods cannot have classical order four). However, we also prove that effective order five methods---like classical order five methods---require the use of nonpositive weights and so cannot be SSP. By numerical optimization, we construct explicit SSP Runge--Kutta methods up to effective order four and establish the optimality of many of them. Numerical experiments demonstrate the validity of these methods in practice.

  1. Using strong nonlinearity and high-frequency vibrations to control effective mechanical stiffness

    DEFF Research Database (Denmark)

    Thomsen, Jon Juel

    2008-01-01

    High-frequency excitation (HFE) can be used to change the effective stiffness of an elastic structure, and related quanti-ties such as resonance frequencies, wave speed, buckling loads, and equilibrium states. There are basically two ways to do this: By using parametrical HFE (with or without non...... the method of direct separation of motions with results of a modified multiple scales ap-proach, valid also for strong nonlinearity, the stiffening ef-fect is predicted for a generic 1-dof system, and results are tested against numerical simulation and ((it is planned)) laboratory experiments....

  2. Three-loop Standard Model effective potential at leading order in strong and top Yukawa couplings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Stephen P. [Santa Barbara, KITP

    2014-01-08

    I find the three-loop contribution to the effective potential for the Standard Model Higgs field, in the approximation that the strong and top Yukawa couplings are large compared to all other couplings, using dimensional regularization with modified minimal subtraction. Checks follow from gauge invariance and renormalization group invariance. I also briefly comment on the special problems posed by Goldstone boson contributions to the effective potential, and on the numerical impact of the result on the relations between the Higgs vacuum expectation value, mass, and self-interaction coupling.

  3. Attosecond counter-rotating-wave effect in xenon driven by strong fields

    Science.gov (United States)

    Anand, M.; Pabst, Stefan; Kwon, Ojoon; Kim, Dong Eon

    2017-05-01

    We investigate the subfemtosecond dynamics of a highly excited xenon atom coherently driven by a strong control field at which the Rabi frequency of the system is comparable to the frequency of a driving laser. The widely used rotating-wave approximation breaks down at such fields, resulting in features such as the counter-rotating-wave (CRW) effect. We present a time-resolved observation of the CRW effect in the highly excited 4 d-1n p xenon using attosecond transient absorption spectroscopy. Time-dependent many-body theory confirms the observation and explains the various features of the absorption spectrum seen in experiment.

  4. Interaction effects in a microscopic quantum wire model with strong spin-orbit interaction

    Science.gov (United States)

    Winkler, G. W.; Ganahl, M.; Schuricht, D.; Evertz, H. G.; Andergassen, S.

    2017-06-01

    We investigate the effect of strong interactions on the spectral properties of quantum wires with strong Rashba spin-orbit (SO) interaction in a magnetic field, using a combination of matrix product state and bosonization techniques. Quantum wires with strong Rashba SO interaction and magnetic field exhibit a partial gap in one-half of the conducting modes. Such systems have attracted wide-spread experimental and theoretical attention due to their unusual physical properties, among which are spin-dependent transport, or a topological superconducting phase when under the proximity effect of an s-wave superconductor. As a microscopic model for the quantum wire we study an extended Hubbard model with SO interaction and Zeeman field. We obtain spin resolved spectral densities from the real-time evolution of excitations, and calculate the phase diagram. We find that interactions increase the pseudo gap at k = 0 and thus also enhance the Majorana-supporting phase and stabilize the helical spin order. Furthermore, we calculate the optical conductivity and compare it with the low energy spiral Luttinger liquid result, obtained from field theoretical calculations. With interactions, the optical conductivity is dominated by an excotic excitation of a bound soliton-antisoliton pair known as a breather state. We visualize the oscillating motion of the breather state, which could provide the route to their experimental detection in e.g. cold atom experiments.

  5. Charging-delay effect on longitudinal dust acoustic shock wave in strongly coupled dusty plasma

    International Nuclear Information System (INIS)

    Ghosh, Samiran; Gupta, M.R.

    2005-01-01

    Taking into account the charging-delay effect, the nonlinear propagation characteristics of longitudinal dust acoustic wave in strongly coupled collisional dusty plasma described by generalized hydrodynamic model have been investigated. In the 'hydrodynamic limit', a Korteweg-de Vries Burger (KdVB) equation with a damping term arising due to dust-neutral collision is derived in which the Burger term is proportional to the dissipation due to dust viscosity through dust-dust correlation and charging-delay-induced anomalous dissipation. On the other hand, in the 'kinetic limit', a KdVB equation with a damping term and a nonlocal nonlinear forcing term arising due to memory-dependent strong correlation effect of dust fluid is derived in which the Burger term depends only on the charging-delay-induced dissipation. Numerical solution of integrodifferential equations reveals that (i) dissipation due to dust viscosity and principally due to charging delay causes excitation of the longitudinal dust acoustic shock wave in strongly coupled dusty plasma and (ii) dust-neutral collision does not appear to play any direct role in shock formation. The condition for the generation of shock is also discussed briefly

  6. Challenges in inflationary magnetogenesis: Constraints from strong coupling, backreaction, and the Schwinger effect

    Science.gov (United States)

    Sharma, Ramkishor; Jagannathan, Sandhya; Seshadri, T. R.; Subramanian, Kandaswamy

    2017-10-01

    Models of inflationary magnetogenesis with a coupling to the electromagnetic action of the form f2Fμ νFμ ν , are known to suffer from several problems. These include the strong coupling problem, the backreaction problem and also strong constraints due to the Schwinger effect. We propose a model which resolves all these issues. In our model, the coupling function, f , grows during inflation and transits to a decaying phase post-inflation. This evolutionary behavior is chosen so as to avoid the problem of strong coupling. By assuming a suitable power-law form of the coupling function, we can also neglect backreaction effects during inflation. To avoid backreaction post-inflation, we find that the reheating temperature is restricted to be below ≈1.7 ×104 GeV . The magnetic energy spectrum is predicted to be nonhelical and generically blue. The estimated present day magnetic field strength and the corresponding coherence length taking reheating at the QCD epoch (150 MeV) are 1.4 ×10-12 G and 6.1 ×10-4 Mpc , respectively. This is obtained after taking account of nonlinear processing over and above the flux-freezing evolution after reheating. If we consider also the possibility of a nonhelical inverse transfer, as indicated in direct numerical simulations, the coherence length and the magnetic field strength are even larger. In all cases mentioned above, the magnetic fields generated in our models satisfy the γ -ray bound below a certain reheating temperature.

  7. Extended Parrondo's game and Brownian ratchets: Strong and weak Parrondo effect

    Science.gov (United States)

    Wu, Degang; Szeto, Kwok Yip

    2014-02-01

    Inspired by the flashing ratchet, Parrondo's game presents an apparently paradoxical situation. Parrondo's game consists of two individual games, game A and game B. Game A is a slightly losing coin-tossing game. Game B has two coins, with an integer parameter M. If the current cumulative capital (in discrete unit) is a multiple of M, an unfavorable coin pb is used, otherwise a favorable pg coin is used. Paradoxically, a combination of game A and game B could lead to a winning game, which is the Parrondo effect. We extend the original Parrondo's game to include the possibility of M being either M1 or M2. Also, we distinguish between strong Parrondo effect, i.e., two losing games combine to form a winning game, and weak Parrondo effect, i.e., two games combine to form a better-performing game. We find that when M2 is not a multiple of M1, the combination of B (M1) and B (M2) has strong and weak Parrondo effect for some subsets in the parameter space (pb,pg), while there is neither strong nor weak effect when M2 is a multiple of M1. Furthermore, when M2 is not a multiple of M1, a stochastic mixture of game A may cancel the strong and weak Parrondo effect. Following a discretization scheme in the literature of Parrondo's game, we establish a link between our extended Parrondo's game with the analysis of discrete Brownian ratchet. We find a relation between the Parrondo effect of our extended model to the macroscopic bias in a discrete ratchet. The slope of a ratchet potential can be mapped to the fair game condition in the extended model, so that under some conditions, the macroscopic bias in a discrete ratchet can provide a good predictor for the game performance of the extended model. On the other hand, our extended model suggests a design of a ratchet in which the potential is a mixture of two periodic potentials.

  8. Strong coupling effects between a meta-atom and MIM nanocavity

    Directory of Open Access Journals (Sweden)

    San Chen

    2012-09-01

    Full Text Available In this paper, we investigate the strong coupling effects between a meta-atom and a metal-insulator-metal (MIM nanocavity. By changing the meta-atom sizes, we achieve the meta-atomic electric dipole, quadrupole or multipole interaction with the plasmonic nanocavity, in which characteristic anticrossing behaviors demonstrate the occurrence of the strong coupling. The various interactions present obviously different splitting values and behaviors of dependence on the meta-atomic position. The largest Rabi-type splittings, about 360.0 meV and 306.1 meV, have been obtained for electric dipole and quadrupole interaction, respectively. We attribute the large splitting to the highly-confined cavity mode and the large transition dipole of the meta-atom. Also the Rabi-type oscillation in time domain is given.

  9. Realization of effective super Tonks-Girardeau gases via strongly attractive one-dimensional Fermi gases

    International Nuclear Information System (INIS)

    Chen Shu; Yin Xiangguo; Guan Liming; Guan Xiwen; Batchelor, M. T.

    2010-01-01

    A significant feature of the one-dimensional super Tonks-Girardeau gas is its metastable gas-like state with a stronger Fermi-like pressure than for free fermions which prevents a collapse of atoms. This naturally suggests a way to search for such strongly correlated behavior in systems of interacting fermions in one dimension. We thus show that the strongly attractive Fermi gas without polarization can be effectively described by a super Tonks-Girardeau gas composed of bosonic Fermi pairs with attractive pair-pair interaction. A natural description of such super Tonks-Girardeau gases is provided by Haldane generalized exclusion statistics. In particular, they are equivalent to ideal particles obeying more exclusive statistics than Fermi-Dirac statistics.

  10. Effects of Strong Correlations on the Disorder-Induced Zero Bias Anomaly

    Science.gov (United States)

    Atkinson, William; Song, Yun; Bulut, Sinan; Wortis, Rachel

    2009-03-01

    In conventional metals and semiconductors, density of states anomalies result from the interplay between disorder and interactions. Motivated by a number of experiments that find zero bias anomalies (ZBA) in transition metal oxides, we have performed calculations to determine the effect of strong correlations on the ZBA in disordered interacting systems. We use a self-consistent mean-field theory that incorporates strong correlations and treats spatial fluctuations of the disorder potential exactly. We discuss both the Anderson-Hubbard model and the extended Anderson-Hubbard model. We find that, even for a zero-range interaction, nonlocal self-energy corrections lead to the formation of an Altshuler-Aronov-like ZBA. In the extended Anderson-Hubbard model, Efros-Shklovskii-like physics dominates at large disorder.

  11. Effective action for superfluid Fermi systems in the strong-coupling limit

    International Nuclear Information System (INIS)

    Dupuis, N.

    2005-01-01

    We derive the low-energy effective action for three-dimensional superfluid Fermi systems in the strong-coupling limit, where superfluidity originates from Bose-Einstein condensation of composite bosons. Taking into account density and pairing fluctuations on the same footing, we show that the effective action involves only the fermion density ρ r and its conjugate variable, the phase θ r of the pairing order parameter Δ r . We recover the standard action of a Bose superfluid of density ρ r /2, where the bosons have a mass m B =2m and interact via a repulsive contact potential with amplitude g B =4πa B /m B ,a B =2a (a the s-wave scattering length associated to the fermion-fermion interaction in vacuum). For lattice models, the derivation of the effective action is based on the mapping of the attractive Hubbard model onto the Heisenberg model in a uniform magnetic field, and a coherent state path integral representation of the partition function. The effective description of the Fermi superfluid in the strong-coupling limit is a Bose-Hubbard model with an intersite hopping amplitude t B =J/2 and an on-site repulsive interaction U B =2Jz, where J=4t 2 /U (t and -U are the intersite hopping amplitude and the on-site attraction in the (fermionic) Hubbard model, z the number of nearest-neighbor sites)

  12. Effective action for superfluid Fermi systems in the strong-coupling limit

    Science.gov (United States)

    Dupuis, N.

    2005-07-01

    We derive the low-energy effective action for three-dimensional superfluid Fermi systems in the strong-coupling limit, where superfluidity originates from Bose-Einstein condensation of composite bosons. Taking into account density and pairing fluctuations on the same footing, we show that the effective action involves only the fermion density ρr and its conjugate variable, the phase θr of the pairing order parameter Δr . We recover the standard action of a Bose superfluid of density ρr/2 , where the bosons have a mass mB=2m and interact via a repulsive contact potential with amplitude gB=4πaB/mB,aB=2a ( a the s -wave scattering length associated to the fermion-fermion interaction in vacuum). For lattice models, the derivation of the effective action is based on the mapping of the attractive Hubbard model onto the Heisenberg model in a uniform magnetic field, and a coherent state path integral representation of the partition function. The effective description of the Fermi superfluid in the strong-coupling limit is a Bose-Hubbard model with an intersite hopping amplitude tB=J/2 and an on-site repulsive interaction UB=2Jz , where J=4t2/U ( t and -U are the intersite hopping amplitude and the on-site attraction in the (fermionic) Hubbard model, z the number of nearest-neighbor sites).

  13. Effects of strong radiation reaction and quantum-electrodynamics on relativistic transparency

    Science.gov (United States)

    Zhang, Peng; Thomas, A. G. R.; Ridgers, C. P.

    2013-10-01

    Relativistic transparency is the process that optically switches the overdense plasma from opaque to transparent and enables light propagation through the otherwise opaque plasma, when light of sufficient intensity drives the electrons in the plasma to near light speeds. We study the relativistic transparency in radiation dominant and strong quantum electrodynamic (QED) regime, for the interaction of high-intensity laser pulses with a thin foil solid target. We analytically study the simplified motion of an electron in a circularly polarized plane wave to understand the physics of the transmissivity and absorption in the presence of classical and quantum-corrected, semiclassical radiation-reaction forces and the trapping of particles in nodes of laser standing wave through radiative cooling. These arguments are supported by both one dimensional and two dimensional particle-in-cell calculations including strong field QED effects. Measurement of the transmission of these pulses would be experimentally feasible and a robust test of the strong field QED particle-in-cell framework.

  14. Drag Effect of Kompsat-1 During Strong Solar and Geomagnetic Activity

    Directory of Open Access Journals (Sweden)

    J. Park

    2007-06-01

    Full Text Available In this paper, we analyze the orbital variation of the KOrea Multi-Purpose SATellite-1(KOMPSAT-1 in a strong space environment due to satellite drag by solar and geomagnetic activities. The satellite drag usually occurs slowly, but becomes serious satellite drag when the space environment suddenly changes via strong solar activity like a big flare eruption or coronal mass ejections(CMEs. Especially, KOMPSAT-1 as a low earth orbit satellite has a distinct increase of the drag acceleration by the variations of atmospheric friction. We consider factors of solar activity to have serious effects on the satellite drag from two points of view. One is an effect of high energy radiation when the flare occurs in the Sun. This radiation heats and expands the upper atmosphere of the Earth as the number of neutral particles is suddenly increased. The other is an effect of Joule and precipitating particle heating caused by current of plasma and precipitation of particles during geomagnetic storms by CMEs. It also affects the density of neutral particles by heating the upper atmosphere. We investigate the satellite drag acceleration associated with the two factors for five events selected based on solar and geomagnetic data from 2001 to 2002. The major results can be summarized as follows. First, the drag acceleration started to increase with solar EUV radiation with the best cross-correlation (r = 0.92 for 1 day delayed F10.7. Second, the drag acceleration and Dst index have similar patterns when the geomagnetic storm is dominant and the drag acceleration abruptly increases during the strong geomagnetic storm. Third, the background variation of the drag accelerations is governed by the solar radiation, while their short term (less than a day variations is governed by geomagnetic storms.

  15. Poly-ϵ-caprolactone/chitosan nanoparticles provide strong adjuvant effect for hepatitis B antigen.

    Science.gov (United States)

    Jesus, Sandra; Soares, Edna; Borchard, Gerrit; Borges, Olga

    2017-10-01

    This work aims to investigate the adjuvant effect of poly-ϵ-caprolactone/chitosan nanoparticles (NPs) for hepatitis B surface antigen (HBsAg) and the plasmid DNA encoding HBsAg (pRC/CMV-HBs). Both antigens were adsorbed onto preformed NPs. Vaccination studies were performed in C57BL/6 mice. Transfection efficiency was investigated in A549 cell line. HBsAg-adsorbed NPs generated strong anti-HBsAg IgG titers, mainly of IgG1 isotype, and induced antigen-specific IFN-γ and IL-17 secretion by spleen cells. The addition of pRC/CMV-HBs to the HBsAg-adsorbed NPs inhibited IL-17 secretion but had minor effect on IFN-γ levels. Lastly, pRC/CMV-HBs-loaded NPs generated a weak serum antibody response. Poly-ϵ-caprolactone/chitosan NPs provide a strong humoral adjuvant effect for HBsAg and induce a Th1/Th17-mediated cellular immune responses worth explore for hepatitis B virus vaccination.

  16. Dispersion of Co/CNTs via strong electrostatic adsorption method: Thermal treatment effect

    Energy Technology Data Exchange (ETDEWEB)

    Akbarzadeh, Omid, E-mail: omid.akbarzadeh63@gmail.com; Abdullah, Bawadi, E-mail: bawadi-abdullah@petronas.com.my; Subbarao, Duvvuri, E-mail: duvvuri-subbarao@petronas.com.my [Department of Chemical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Zabidi, Noor Asmawati Mohd, E-mail: noorasmawati-mzabidi@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    The effect of different thermal treatment temperature on the structure of multi-walled carbon nanotubes (MWCNTs) and Co particle dispersion on CNTs support is studied using Strong electrostatic adsorption (SEA) method. The samples tested by N{sub 2}-adsorption, field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). N{sub 2}-adsorption results showed BET surface area increased using thermal treatment and TEM images showed that increasing the thermal treatment temperature lead to flaky CNTs and defects introduced on the outer surface and Co particle dispersion increased.

  17. Gain length fitting formula for free-electron lasers with strong space-charge effects

    Directory of Open Access Journals (Sweden)

    G. Marcus

    2011-08-01

    Full Text Available We present a power-fit formula, obtained from a variational analysis using three-dimensional free-electron laser theory, for the gain length of a high-gain free-electron laser’s fundamental mode in the presence of diffraction, uncorrelated energy spread, and longitudinal space-charge effects. The approach is inspired by the work of Xie [Nucl. Instrum. Methods Phys. Res., Sect. A 445, 59 (2000NIMAER0168-900210.1016/S0168-9002(0000114-5], and provides a useful shortcut for calculating the gain length of the fundamental Gaussian mode of a free-electron laser having strong space-charge effects in the 3D regime. The results derived from analytic theory are in good agreement with detailed numerical particle simulations that also include higher-order space-charge effects, supporting the assumptions made in the theoretical treatment and the variational solutions obtained in the single-mode limit.

  18. STRONG FIELD EFFECTS ON EMISSION LINE PROFILES: KERR BLACK HOLES AND WARPED ACCRETION DISKS

    International Nuclear Information System (INIS)

    Wang Yan; Li Xiangdong

    2012-01-01

    If an accretion disk around a black hole is illuminated by hard X-rays from non-thermal coronae, fluorescent iron lines will be emitted from the inner region of the accretion disk. The emission line profiles will show a variety of strong field effects, which may be used as a probe of the spin parameter of the black hole and the structure of the accretion disk. In this paper, we generalize the previous relativistic line profile models by including both the black hole spinning effects and the non-axisymmetries of warped accretion disks. Our results show different features from the conventional calculations for either a flat disk around a Kerr black hole or a warped disk around a Schwarzschild black hole by presenting, at the same time, multiple peaks, rather long red tails, and time variations of line profiles with the precession of the disk. We show disk images as seen by a distant observer, which are distorted by the strong gravity. Although we are primarily concerned with the iron K-shell lines in this paper, the calculation is general and is valid for any emission lines produced from a warped accretion disk around a black hole.

  19. Non trivial effect of strong high-frequency excitation on a nonlinear controlled system

    DEFF Research Database (Denmark)

    Fidlin, A.; Thomsen, Jon Juel

    2004-01-01

    due to control is usually high compared to uncontrolled systems. A standard optimal controller for a standard nonlinear system (a movable cart used to balance a pendulum vertically) is shown to exhibit pronounced bias error in presence of HF-excitation. The bias increases with increased excitation......Nontrivial effects of high-frequency excitation on mechanical uncontrolled systems have been investigated intensively in the last decade. Some of these effects are usually used in controlled systems in form of dither to smoothen out undesired friction and hysteresis. However the level of damping...... intensity, but it also increases with the increased control power. Analytic prediction for the bias shows, the interaction between fast excitation and strong damping terms in the control system to be the cause of the permanent control error. A "slow observer" ignoring fast motions is shown...

  20. Trapped in the extinction vortex? Strong genetic effects in a declining vertebrate population

    Directory of Open Access Journals (Sweden)

    Larsson Mikael

    2010-02-01

    Full Text Available Abstract Background Inbreeding and loss of genetic diversity are expected to increase the extinction risk of small populations, but detailed tests in natural populations are scarce. We combine long-term population and fitness data with those from two types of molecular markers to examine the role of genetic effects in a declining metapopulation of southern dunlins Calidris alpina schinzii, an endangered shorebird. Results The decline is associated with increased pairings between related individuals, including close inbreeding (as revealed by both field observations of parentage and molecular markers. Furthermore, reduced genetic diversity seems to affect individual fitness at several life stages. Higher genetic similarity between mates correlates negatively with the pair's hatching success. Moreover, offspring produced by related parents are more homozygous and suffer from increased mortality during embryonic development and possibly also after hatching. Conclusions Our results demonstrate strong genetic effects in a rapidly declining population, emphasizing the importance of genetic factors for the persistence of small populations.

  1. Strong matrix effect in low-energy He+ ion scattering from carbon

    International Nuclear Information System (INIS)

    Mikhailov, S.N.; Van den Oetelaar, L.C.A.; Brongersma, H.H.

    1994-01-01

    In low-energy ion scattering the contribution of neutralization processes to the scattered ion yield is very important in quantification. Neutralization of low-energy (1-3.5 keV) He + ions by carbon is found to be much stronger for graphitic than for carbidic carbon. The ion fraction for graphitic carbon for 2.5 keV 3 He + scattering over 136 is about 60 times lower than that for carbidic carbon. For the 4 He + isotope the effect is even larger. Such a strong matrix effect for one element has not been measured before in low-energy (1-3.5 keV) inert-gas ion scattering. The neutralization behaviour is discussed in terms of a special quasi-resonant neutralization process for graphite. ((orig.))

  2. Strongly correlated Fermi-systems: Non-Fermi liquid behavior, quasiparticle effective mass and their interplay

    Energy Technology Data Exchange (ETDEWEB)

    Shaginyan, V.R. [Petersburg Nuclear Physics Institute, RAS, Gatchina 188300 (Russian Federation); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)], E-mail: vrshag@thd.pnpi.spb.ru; Amusia, M.Ya. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Popov, K.G. [Komi Science Center, Ural Division, RAS, Syktyvkar 167982 (Russian Federation)

    2009-06-15

    Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc., gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh{sub 2}Si{sub 2}.

  3. Strongly correlated Fermi-systems: Non-Fermi liquid behavior, quasiparticle effective mass and their interplay

    International Nuclear Information System (INIS)

    Shaginyan, V.R.; Amusia, M.Ya.; Popov, K.G.

    2009-01-01

    Basing on the density functional theory of fermion condensation, we analyze the non-Fermi liquid behavior of strongly correlated Fermi-systems such as heavy-fermion metals. When deriving equations for the effective mass of quasiparticles, we consider solids with a lattice and homogeneous systems. We show that the low-temperature thermodynamic and transport properties are formed by quasiparticles, while the dependence of the effective mass on temperature, number density, magnetic fields, etc., gives rise to the non-Fermi liquid behavior. Our theoretical study of the heat capacity, magnetization, energy scales, the longitudinal magnetoresistance and magnetic entropy are in good agreement with the remarkable recent facts collected on the heavy-fermion metal YbRh 2 Si 2 .

  4. Splicing landscape of the eight collaborative cross founder strains.

    Science.gov (United States)

    Zheng, Christina L; Wilmot, Beth; Walter, Nicole Ar; Oberbeck, Denesa; Kawane, Sunita; Searles, Robert P; McWeeney, Shannon K; Hitzemann, Robert

    2015-02-05

    The Collaborative Cross (CC) is a large panel of genetically diverse recombinant inbred mouse strains specifically designed to provide a systems genetics resource for the study of complex traits. In part, the utility of the CC stems from the extensive genome-wide annotations of founder strain sequence and structural variation. Still missing, however, are transcriptome-specific annotations of the CC founder strains that could further enhance the utility of this resource. We provide a comprehensive survey of the splicing landscape of the 8 CC founder strains by leveraging the high level of alternative splicing within the brain. Using deep transcriptome sequencing, we found that a majority of the splicing landscape is conserved among the 8 strains, with ~65% of junctions being shared by at least 2 strains. We, however, found a large number of potential strain-specific splicing events as well, with an average of ~3000 and ~500 with ≥3 and ≥10 sequence read coverage, respectively, within each strain. To better understand strain-specific splicing within the CC founder strains, we defined criteria for and identified high-confidence strain-specific splicing events. These splicing events were defined as exon-exon junctions 1) found within only one strain, 2) with a read coverage ≥10, and 3) defined by a canonical splice site. With these criteria, a total of 1509 high-confidence strain-specific splicing events were identified, with the majority found within two of the wild-derived strains, CAST and PWK. Strikingly, the overwhelming majority, 94%, of these strain-specific splicing events are not yet annotated. Strain-specific splicing was also located within genomic regions recently reported to be over- and under-represented within CC populations. Phenotypic characterization of CC populations is increasing; thus these results will not only aid in further elucidating the transcriptomic architecture of the individual CC founder strains, but they will also help in guiding

  5. Bactericidal Effect of Strong Acid Electrolyzed Water against Flow Enterococcus faecalis Biofilms.

    Science.gov (United States)

    Cheng, Xiaogang; Tian, Yu; Zhao, Chunmiao; Qu, Tiejun; Ma, Chi; Liu, Xiaohua; Yu, Qing

    2016-07-01

    This study evaluated the bactericidal effect of strong acid electrolyzed water (SAEW) against flow Enterococcus faecalis biofilm and its potential application as a root canal irrigant. Flow E. faecalis biofilms were generated under a constant shear flow in a microfluidic system. For comparison, static E. faecalis biofilms were generated under a static condition on coverslip surfaces. Both the flow and static E. faecalis biofilms were treated with SAEW. Sodium hypochlorite (NaOCl, 5.25%) and normal saline (0.9%) were included as the controls. Bacterial reductions were evaluated using confocal laser scanning microscopy and the cell count method. Morphological changes of bacterial cells were observed using scanning electron microscopy. The confocal laser scanning microscopic and cell count results showed that SAEW had a bactericidal effect similar to that of 5.25% NaOCl against both the flow and static E. faecalis biofilms. The scanning electron microscopic results showed that smooth, consecutive, and bright bacteria surfaces became rough, shrunken, and even lysed after treated with SAEW, similar to those in the NaOCl group. SAEW had an effective bactericidal effect against both the flow and static E. faecalis biofilms, and it might be qualified as a root canal irrigant for effective root canal disinfection. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Long-term effects of the strong African American families program on youths' alcohol use.

    Science.gov (United States)

    Brody, Gene H; Chen, Yi-Fu; Kogan, Steven M; Murry, Velma McBride; Brown, Anita C

    2010-04-01

    This report extends earlier accounts by addressing the effects of the Strong African American Families (SAAF) program across 65 months. Two hypotheses were tested: (a) Rural African American youths randomly assigned to participate in SAAF would demonstrate lower rates of alcohol use than would control youths more than 5 years later, and (b) SAAF's effects on deterring the onset of alcohol use in early adolescence would carry forward to mediate the program's long-term effects. African American youths in rural Georgia (mean age at pretest = 10.8 years) were assigned randomly to the SAAF group (n = 369) or to a control group (n = 298). Past-month alcohol use was assessed at pretest and at 9, 18, 29, 53, and 65 months after pretest. SAAF participants increased their alcohol use at a slower rate than did adolescents in the control condition across the follow-up assessments. At the 65-month assessment, SAAF participants reported having drunk alcohol half as often as did youths in the control group. Consistent with the second hypothesis, SAAF's effects on deterring initiation carried forward to account for its effects on alcohol use across time. Training in protective parenting processes and self-regulatory skills during preadolescence may contribute to a self-sustaining trajectory of disinterest in and avoidance of alcohol use during adolescence when peers begin to model and sanction it. (c) 2010 APA, all rights reserved

  7. Fitness is strongly influenced by rare mutations of large effect in a microbial mutation accumulation experiment.

    Science.gov (United States)

    Heilbron, Karl; Toll-Riera, Macarena; Kojadinovic, Mila; MacLean, R Craig

    2014-07-01

    Our understanding of the evolutionary consequences of mutation relies heavily on estimates of the rate and fitness effect of spontaneous mutations generated by mutation accumulation (MA) experiments. We performed a classic MA experiment in which frequent sampling of MA lines was combined with whole genome resequencing to develop a high-resolution picture of the effect of spontaneous mutations in a hypermutator (ΔmutS) strain of the bacterium Pseudomonas aeruginosa. After ∼644 generations of mutation accumulation, MA lines had accumulated an average of 118 mutations, and we found that average fitness across all lines decayed linearly over time. Detailed analyses of the dynamics of fitness change in individual lines revealed that a large fraction of the total decay in fitness (42.3%) was attributable to the fixation of rare, highly deleterious mutations (comprising only 0.5% of fixed mutations). Furthermore, we found that at least 0.64% of mutations were beneficial and probably fixed due to positive selection. The majority of mutations that fixed (82.4%) were base substitutions and we failed to find any signatures of selection on nonsynonymous or intergenic mutations. Short indels made up a much smaller fraction of the mutations that were fixed (17.4%), but we found evidence of strong selection against indels that caused frameshift mutations in coding regions. These results help to quantify the amount of natural selection present in microbial MA experiments and demonstrate that changes in fitness are strongly influenced by rare mutations of large effect. Copyright © 2014 by the Genetics Society of America.

  8. Strong isotope effects on melting dynamics and ice crystallisation processes in cryo vitrification solutions.

    Directory of Open Access Journals (Sweden)

    Oleg Kirichek

    Full Text Available The nucleation and growth of crystalline ice during cooling, and further crystallization processes during re-warming are considered to be key processes determining the success of low temperature storage of biological objects, as used in medical, agricultural and nature conservation applications. To avoid these problems a method, termed vitrification, is being developed to inhibit ice formation by use of high concentration of cryoprotectants and ultra-rapid cooling, but this is only successful across a limited number of biological objects and in small volume applications. This study explores physical processes of ice crystal formation in a model cryoprotective solution used previously in trials on vitrification of complex biological systems, to improve our understanding of the process and identify limiting biophysical factors. Here we present results of neutron scattering experiments which show that even if ice crystal formation has been suppressed during quench cooling, the water molecules, mobilised during warming, can crystallise as detectable ice. The crystallisation happens right after melting of the glass phase formed during quench cooling, whilst the sample is still transiting deep cryogenic temperatures. We also observe strong water isotope effects on ice crystallisation processes in the cryoprotectant mixture. In the neutron scattering experiment with a fully protiated water component, we observe ready crystallisation occurring just after the glass melting transition. On the contrary with a fully deuteriated water component, the process of crystallisation is either completely or substantially supressed. This behaviour might be explained by nuclear quantum effects in water. The strong isotope effect, observed here, may play an important role in development of new cryopreservation strategies.

  9. Effect of Floodplain Inundation on River Pollution in Taiwan's Strong Monsoonal Climate

    Science.gov (United States)

    Hester, E. T.; Lin, A. Y. C.

    2017-12-01

    River-floodplain interaction provides important benefits such as flood mitigation, provision of ecological habitat, and improved water quality. Human actions have historically reduced such interaction and associated benefits by diking, floodplain fill, and river regulation. In response, floodplain restoration has become popular in North America and Europe, but is less practiced in Asia. In Taiwan, unusually strong monsoons and steep terrain alter floodplain dynamics relative to elsewhere around the world, and provide a unique environment for floodplain management. We used numerical models of flow, transport, and reaction in river channels and floodplains to quantify the effect of river-floodplain interaction on water quality in Taiwan's strong monsoon and high topographic relief. We conducted sensitivity analyses of parameters such as river slope, monsoon severity, reservoir operation mode, degree of floodplain reconnection, contaminant reaction rate, and contaminant reaction type on floodplain connectivity and contaminant mitigation. We found significant differences in floodplain hydraulics and residence times in Taiwan's steep monsoonal environment relative to the shallower non-monsoonal environment typical of the eastern USA, with significant implications for water quality. For example, greater flashiness of floodplain inundation in Taiwan provides greater challenges for reconnecting sufficient floodplain volume to handle monsoonal runoff. Yet longer periods when floodplains are reliably dry means that such lands may have greater value for seasonal use such as parks or agriculture. The potential for floodplain restoration in Taiwan is thus significant, but qualitatively different than in the eastern USA.

  10. Mental health care and average happiness: strong effect in developed nations.

    Science.gov (United States)

    Touburg, Giorgio; Veenhoven, Ruut

    2015-07-01

    Mental disorder is a main cause of unhappiness in modern society and investment in mental health care is therefore likely to add to average happiness. This prediction was checked in a comparison of 143 nations around 2005. Absolute investment in mental health care was measured using the per capita number of psychiatrists and psychologists working in mental health care. Relative investment was measured using the share of mental health care in the total health budget. Average happiness in nations was measured with responses to survey questions about life-satisfaction. Average happiness appeared to be higher in countries that invest more in mental health care, both absolutely and relative to investment in somatic medicine. A data split by level of development shows that this difference exists only among developed nations. Among these nations the link between mental health care and happiness is quite strong, both in an absolute sense and compared to other known societal determinants of happiness. The correlation between happiness and share of mental health care in the total health budget is twice as strong as the correlation between happiness and size of the health budget. A causal effect is likely, but cannot be proved in this cross-sectional analysis.

  11. Muir-Torre Syndrome and founder mismatch repair gene mutations: A long gone historical genetic challenge.

    Science.gov (United States)

    Ponti, G; Manfredini, M; Tomasi, A; Pellacani, G

    2016-09-10

    A "cancer predisposing syndrome" later labeled as Hereditary Non-Polyposis Colorectal Cancer (HNPCC) or Lynch Syndrome, was firstly described by Warthin, about one century ago. An increased predisposition to the development of multiple familial tumors is described as characteristic of this syndrome where visceral and cutaneous malignancies may appear at an early age namely endometrial, gastric, small bowel, ureteral and renal pelvis, ovarian, hepatobiliary tract, pancreatic, brain (Turcot Syndrome) and sebaceous glands (Muir-Torre Syndrome). The latter, a variant of Lynch Syndrome, is characterized by the presence of sebaceous skin adenomas, carcinomas and/or keratoacanthomas associated with visceral malignancies. Both Lynch Syndrome and Muir-Torre Syndrome have been recognized due to germline mutations in mismatch repair genes MLH1, MSH2 and MSH6. To date, 56 Lynch Syndrome founder mutations dependent on MLH1, MSH2 and, although less frequently found, MSH6 and PMS2 are described. Some of these founder mutations, principally of MSH2 gene, have been described to cause Muir-Torre phenotype and have been traced in large and outbreed Muir-Torre Syndrome families living in different US and European territories. Due to the evidences of highly specific Muir-Torre phenotypes related to the presence of widespread MSH2 founder mutations, preliminary search for these MSH2 common mutations in individuals carrying sebaceous tumors and/or keratoacanthomas, at early age or in association to visceral and familial tumors, permits cost-effective and time-saving diagnostic strategies for Lynch/Muir-Torre Syndromes. Copyright © 2015. Published by Elsevier B.V.

  12. Biodiversity effects in the wild are common and as strong as key drivers of productivity

    Science.gov (United States)

    Duffy, J. Emmett; Godwin, Casey M.; Cardinale, Bradley J.

    2017-09-01

    More than 500 controlled experiments have collectively suggested that biodiversity loss reduces ecosystem productivity and stability. Yet the importance of biodiversity in sustaining the world’s ecosystems remains controversial, largely because of the lack of validation in nature, where strong abiotic forcing and complex interactions are assumed to swamp biodiversity effects. Here we test this assumption by analysing 133 estimates reported in 67 field studies that statistically separated the effects of biodiversity on biomass production from those of abiotic forcing. Contrary to the prevailing opinion of the previous two decades that biodiversity would have rare or weak effects in nature, we show that biomass production increases with species richness in a wide range of wild taxa and ecosystems. In fact, after controlling for environmental covariates, increases in biomass with biodiversity are stronger in nature than has previously been documented in experiments and comparable to or stronger than the effects of other well-known drivers of productivity, including climate and nutrient availability. These results are consistent with the collective experimental evidence that species richness increases community biomass production, and suggest that the role of biodiversity in maintaining productive ecosystems should figure prominently in global change science and policy.

  13. Biodiversity effects in the wild are common and as strong as key drivers of productivity.

    Science.gov (United States)

    Duffy, J Emmett; Godwin, Casey M; Cardinale, Bradley J

    2017-09-14

    More than 500 controlled experiments have collectively suggested that biodiversity loss reduces ecosystem productivity and stability. Yet the importance of biodiversity in sustaining the world's ecosystems remains controversial, largely because of the lack of validation in nature, where strong abiotic forcing and complex interactions are assumed to swamp biodiversity effects. Here we test this assumption by analysing 133 estimates reported in 67 field studies that statistically separated the effects of biodiversity on biomass production from those of abiotic forcing. Contrary to the prevailing opinion of the previous two decades that biodiversity would have rare or weak effects in nature, we show that biomass production increases with species richness in a wide range of wild taxa and ecosystems. In fact, after controlling for environmental covariates, increases in biomass with biodiversity are stronger in nature than has previously been documented in experiments and comparable to or stronger than the effects of other well-known drivers of productivity, including climate and nutrient availability. These results are consistent with the collective experimental evidence that species richness increases community biomass production, and suggest that the role of biodiversity in maintaining productive ecosystems should figure prominently in global change science and policy.

  14. The strong specific effect of coions on micellar growth from molecular-thermodynamic theory.

    Science.gov (United States)

    Koroleva, S V; Victorov, A I

    2014-09-07

    Viscoelastic solutions of ionic surfactants with an added salt exhibit a surprisingly strong dependence of their behavior on the nature of the added coion. We apply a recently proposed molecular-thermodynamic model to elucidate the effect of a coion's specificity on the aggregation of cationic and anionic surfactants. We show that micellar growth and branching are opposed by penetration of coions inside a micelle's corona leading to an increase of the aggregate's preferential curvature. These effects result from hydration/dehydration and dispersion attraction of coions and are only important at high salinity where electrostatic repulsion of coions from the micelle is screened and where branching of micelles and viscosity maxima are observed. At low and medium salinity, the coion plays a minor role; its effect on critical micelle concentration and sphere-to-rod transitions is insignificant. Our molecular-thermodynamic approach describes the specific effects of both counterions and coions and their different roles at different salinity levels based on a unified physical picture.

  15. Room temperature strong coupling effects from single ZnO nanowire microcavity

    KAUST Repository

    Das, Ayan

    2012-05-01

    Strong coupling effects in a dielectric microcavity with a single ZnO nanowire embedded in it have been investigated at room temperature. A large Rabi splitting of ?100 meV is obtained from the polariton dispersion and a non-linearity in the polariton emission characteristics is observed at room temperature with a low threshold of 1.63 ?J/cm2, which corresponds to a polariton density an order of magnitude smaller than that for the Mott transition. The momentum distribution of the lower polaritons shows evidence of dynamic condensation and the absence of a relaxation bottleneck. The polariton relaxation dynamics were investigated by timeresolved measurements, which showed a progressive decrease in the polariton relaxation time with increase in polariton density. © 2012 Optical Society of America.

  16. Global dynamics and bifurcation analysis of a host-parasitoid model with strong Allee effect.

    Science.gov (United States)

    Khan, Abdul Qadeer; Ma, Jiying; Xiao, Dongmei

    2017-12-01

    In this paper, we study the global dynamics and bifurcations of a two-dimensional discrete time host-parasitoid model with strong Allee effect. The existence of fixed points and their stability are analysed in all allowed parametric region. The bifurcation analysis shows that the model can undergo fold bifurcation and Neimark-Sacker bifurcation. As the parameters vary in a small neighbourhood of the Neimark-Sacker bifurcation condition, the unique positive fixed point changes its stability and an invariant closed circle bifurcates from the positive fixed point. From the viewpoint of biology, the invariant closed curve corresponds to the periodic or quasi-periodic oscillations between host and parasitoid populations. Furthermore, it is proved that all solutions of this model are bounded, and there exist some values of the parameters such that the model has a global attractor. These theoretical results reveal the complex dynamics of the present model.

  17. Strong-field effects in Rabi oscillations between a single state and a superposition of states

    International Nuclear Information System (INIS)

    Zhdanovich, S.; Milner, V.; Hepburn, J. W.

    2011-01-01

    Rabi oscillations of quantum population are known to occur in two-level systems driven by spectrally narrow laser fields. In this work we study Rabi oscillations induced by shaped broadband femtosecond laser pulses. Due to the broad spectral width of the driving field, the oscillations are initiated between a ground state and a coherent superposition of excited states, or a ''wave packet,'' rather than a single excited state. Our experiments reveal an intricate dependence of the wave-packet phase on the intensity of the laser field. We confirm numerically that the effect is associated with the strong-field nature of the interaction and provide a qualitative picture by invoking a simple theoretical model.

  18. Channel-closing effects in strong-field ionization by a bicircular field

    Science.gov (United States)

    Milošević, D. B.; Becker, W.

    2018-03-01

    Channel-closing effects, such as threshold anomalies and resonantlike intensity-dependent enhancements in strong-field ionization by a bicircular laser field are analyzed. A bicircular field consists of two coplanar corotating or counter-rotating circularly polarized fields having different frequencies. For the total detachment rate of a negative ion by a bicircular field we observe threshold anomalies and explain them using the Wigner threshold law and energy and angular momentum conservation. For the corotating bicircular case, these effects are negligible, while for the counter-rotating case they are pronounced and their position depends on the magnetic quantum number of the initial state. For high-order above-threshold ionization of rare-gas atoms by a counter-rotating bicircular laser field we observe very pronounced intensity-dependent enhancements. We find all four types of threshold anomalies known from collision theory. Contrary to the case of linear polarization, channel-closing effects for a bicircular field are visible also in the cutoff region of the electron energy spectrum, which is explained using quantum-orbit theory.

  19. Strong quantum-confined stark effect in germanium quantum-well structures on silicon

    International Nuclear Information System (INIS)

    Kuo, Y.; Lee, Y. K.; Gei, Y.; Ren, S; Roth, J. E.; Miller, D. A.; Harris, J. S.

    2006-01-01

    Silicon is the dominant semiconductor for electronics, but there is now a growing need to integrate such component with optoelectronics for telecommunications and computer interconnections. Silicon-based optical modulators have recently been successfully demonstrated but because the light modulation mechanisms in silicon are relatively weak, long (for example, several millimeters) devices or sophisticated high-quality-factor resonators have been necessary. Thin quantum-well structures made from III-V semiconductors such as GaAs, InP and their alloys exhibit the much stronger Quantum-Confined Stark Effect (QCSE) mechanism, which allows modulator structures with only micrometers of optical path length. Such III-V materials are unfortunately difficult to integrate with silicon electronic devices. Germanium is routinely integrated with silicon in electronics, but previous silicon-germanium structures have also not shown strong modulation effects. Here we report the discovery of the QCSE, at room temperature, in thin germanium quantum-well structures grown on silicon. The QCSE here has strengths comparable to that in III-V materials. Its clarity and strength are particularly surprising because germanium is an indirect gap semiconductor, such semiconductors often display much weak optical effects than direct gap materials (such as the III-V materials typically used for optoelectronics). This discovery is very promising for small, high-speed, low-power optical output devices fully compatible with silicon electronics manufacture. (author)

  20. Strong mechanically induced effects in DC current-biased suspended Josephson junctions

    Science.gov (United States)

    McDermott, Thomas; Deng, Hai-Yao; Isacsson, Andreas; Mariani, Eros

    2018-01-01

    Superconductivity is a result of quantum coherence at macroscopic scales. Two superconductors separated by a metallic or insulating weak link exhibit the AC Josephson effect: the conversion of a DC voltage bias into an AC supercurrent. This current may be used to activate mechanical oscillations in a suspended weak link. As the DC-voltage bias condition is remarkably difficult to achieve in experiments, here we analyze theoretically how the Josephson effect can be exploited to activate and detect mechanical oscillations in the experimentally relevant condition with purely DC current bias. We unveil how changing the strength of the electromechanical coupling results in two qualitatively different regimes showing dramatic effects of the oscillations on the DC-voltage characteristic of the device. These include the appearance of Shapiro-type plateaus for weak coupling and a sudden mechanically induced retrapping for strong coupling. Our predictions, measurable in state-of-the-art experimental setups, allow the determination of the frequency and quality factor of the resonator using DC only techniques.

  1. Eduard Strasburger (1844-1912): founder of modern plant cell biology.

    Science.gov (United States)

    Volkmann, Dieter; Baluška, František; Menzel, Diedrik

    2012-10-01

    Eduard Strasburger, director of the Botany Institute and the Botanical Garden at the University of Bonn from 1881 to 1912, was one of the most admirable scientists in the field of plant biology, not just as the founder of modern plant cell biology but in addition as an excellent teacher who strongly believed in "education through science." He contributed to plant cell biology by discovering the discrete stages of karyokinesis and cytokinesis in algae and higher plants, describing cytoplasmic streaming in different systems, and reporting on the growth of the pollen tube into the embryo sac and guidance of the tube by synergides. Strasburger raised many problems which are hot spots in recent plant cell biology, e.g., structure and function of the plasmodesmata in relation to phloem loading (Strasburger cells) and signaling, mechanisms of cell plate formation, vesicle trafficking as a basis for most important developmental processes, and signaling related to fertilization.

  2. 50 years of Dutch immunology--founders, institutions, highlights.

    Science.gov (United States)

    Gmelig-Meyling, Frits H J; Meyaard, Linde; Mebius, Reina E

    2014-12-01

    At the occasion of the 50th anniversary of the Dutch Society for Immunology (DSI, de Nederlandse Vereniging voor Immunologie), this contribution deals with some highlights of 50 years of Immunology in the Netherlands. It narrates about the founders and first board members of the DSI, their institutes, progeny and patrimony, describes major centers of immunological activities, mentions key persons in the field, and touches upon some events dear to the Society and its members. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields

    International Nuclear Information System (INIS)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields. (author)

  4. Biological effects of electromagnetic fields and recently updated safety guidelines for strong static magnetic fields.

    Science.gov (United States)

    Yamaguchi-Sekino, Sachiko; Sekino, Masaki; Ueno, Shoogo

    2011-01-01

    Humans are exposed daily to artificial and naturally occurring magnetic fields that originate from many different sources. We review recent studies that examine the biological effects of and medical applications involving electromagnetic fields, review the properties of static and pulsed electromagnetic fields that affect biological systems, describe the use of a pulsed electromagnetic field in combination with an anticancer agent as an example of a medical application that incorporates an electromagnetic field, and discuss the recently updated safety guidelines for static electromagnetic fields. The most notable modifications to the 2009 International Commission on Non-Ionizing Radiation Protection guidelines are the increased exposure limits, especially for those who work with or near electromagnetic fields (occupational exposure limits). The recommended increases in exposure were determined using recent scientific evidence obtained from animal and human studies. Several studies since the 1994 publication of the guidelines have examined the effects on humans after exposure to high static electromagnetic fields (up to 9.4 tesla), but additional research is needed to ascertain further the safety of strong electromagnetic fields.

  5. Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum

    Science.gov (United States)

    Fujiwara, Yoshihisa; Tomishige, Masahiko; Itoh, Yasuhiro; Fujiwara, Masao; Shibata, Naho; Kosaka, Toshikazu; Hosoya, Hiroshi; Tanimoto, Yoshifumi

    2006-05-01

    Effect of horizontal strong static magnetic field on swimming behaviour of Paramecium caudatum was studied by using a superconducting magnet. Around a centre of a round vessel, random swimming at 0 T and aligned swimming parallel to the magnetic field (MF) of 8 T were observed. Near a wall of the vessel, however, swimming round and round along the wall at 0 T and aligned swimming of turning at right angles upon collision with the wall, which was remarkable around 1-4 T, were detected. It was experimentally revealed that the former MF-induced parallel swimming at the vessel centre was caused physicochemically by the parallel magnetic orientation of the cell itself. From magnetic field dependence of the extent of the orientation, the magnetic susceptibility anisotropy (χ ∥-χ ⊥) was first obtained to be 3.4× 10-23 emu cell-1 at 298 K for Paramecium caudatum. The orientation of the cell was considered to result from the magnetic orientation of the cell membrane. On the other hand, although mechanisms of the latter swimming near the vessel wall regardless of the absence and presence of the magnetic field are unclear at present, these experimental results indicate that whether the cell exists near the wall alters the magnetic field effect on the swimming in the horizontal magnetic field.

  6. Detailed site effect estimation in the presence of strong velocity reversals within a small-aperture strong-motion array in Iceland

    KAUST Repository

    Rahpeyma, Sahar

    2016-08-11

    The rock site characterization for earthquake engineering applications in Iceland is common due to the easily exposed older bedrock and more recent volcanic lava rock. The corresponding site amplification is generally assumed to be low but has not been comprehensively quantified, especially for volcanic rock. The earthquake strong-motion of the Mw6.3 Ölfus earthquake on 29 May 2008 and 1705 of its aftershocks recorded on the first small-aperture strong-motion array (ICEARRAY I) in Iceland showed consistent and significant variations in ground motion amplitudes over short distances (<2 km) in an urban area located mostly on lava rock. This study analyses the aftershock recordings to quantify the local site effects using the Horizontal to Vertical Spectral Ratio (HVSR) and Standard Spectral Ratio (SSR) methods. Additionally, microseismic data has been collected at array stations and analyzed using the HVSR method. The results between the methods are consistent and show that while the amplification levels remain relatively low, the predominant frequency varies systematically between stations and is found to correlate with the geological units. In particular, for stations on lava rock the underlying geologic structure is characterized by repeated lava-soil stratigraphy characterized by reversals in the shear wave velocity with depth. As a result, standard modeling of HVSR using vertically incident body waves does not apply. Instead, modeling the soil structure as a two-degree-of-freedom dynamic system is found to capture the observed predominant frequencies of site amplification. The results have important implications for earthquake resistant design of structures on rock sites characterized by velocity reversals. © 2016 Elsevier Ltd

  7. Effective potential in the strong-coupling lattice QCD with next-to-next-to-learning order effects

    International Nuclear Information System (INIS)

    Nakano, Takashi Z.; Miura, Kohtaroh; Ohnishi, Akira

    2010-01-01

    We derive an analytic expression of the effective potential at finite temperature (T) and chemical potential (μ) in the strong-coupling lattice QCD for color SU(3) including next-to-next-to-leading order (NNLO) effects in the strong coupling expansion. NNLO effective action terms are systematically evaluated in the leading order of the large dimensional (1/d) expansion, and are found to come from some types of connected two-plaquette configurations. We apply the extended Hubbard-Stratonovich transformation and a gluonic-dressed fermion technique to the effective action, and obtain the effective potential as a function of T, μ, and two order parameters: chiral condensate and vector potential field. The next-to-leading order (NLO) and NNLO effects result in modifications of the wave function renormalization factor, quark mass, and chemical potential. We find that T c,μ =0 and μ c,T =0 are similar to the NLO results, whereas the position of the critical point is sensitive to NNLO corrections. (author)

  8. PRIMAL: Fast and accurate pedigree-based imputation from sequence data in a founder population.

    Directory of Open Access Journals (Sweden)

    Oren E Livne

    2015-03-01

    Full Text Available Founder populations and large pedigrees offer many well-known advantages for genetic mapping studies, including cost-efficient study designs. Here, we describe PRIMAL (PedigRee IMputation ALgorithm, a fast and accurate pedigree-based phasing and imputation algorithm for founder populations. PRIMAL incorporates both existing and original ideas, such as a novel indexing strategy of Identity-By-Descent (IBD segments based on clique graphs. We were able to impute the genomes of 1,317 South Dakota Hutterites, who had genome-wide genotypes for ~300,000 common single nucleotide variants (SNVs, from 98 whole genome sequences. Using a combination of pedigree-based and LD-based imputation, we were able to assign 87% of genotypes with >99% accuracy over the full range of allele frequencies. Using the IBD cliques we were also able to infer the parental origin of 83% of alleles, and genotypes of deceased recent ancestors for whom no genotype information was available. This imputed data set will enable us to better study the relative contribution of rare and common variants on human phenotypes, as well as parental origin effect of disease risk alleles in >1,000 individuals at minimal cost.

  9. Disorder effects on helical edge transport in graphene under a strong tilted magnetic field

    Science.gov (United States)

    Huang, Chunli; Cazalilla, Miguel A.

    2015-10-01

    In a recent experiment, Young et al. [Nature (London) 505, 528 (2014), 10.1038/nature12800] observed a metal to insulator transition as well as transport through helical edge states in monolayer graphene under a strong, tilted magnetic field. Under such conditions, the bulk is a magnetic insulator which can exhibit metallic conduction through helical edges. It was found that the two-terminal conductance of the helical channels deviates from the expected quantized value (=e2/h per edge, at zero temperature). Motivated by this observation, we study the effect of disorder on the conduction through the edge channels. We show that, unlike for helical edges of topological insulators in semiconducting quantum wells, a disorder Rashba spin-orbit coupling does not lead to backscattering, at least to leading order. Instead, we find that the lack of perfect antialignment of the electron spins in the helical channels to be the most likely cause for backscattering arising from scalar (i.e., spin-independent) impurities. The intrinsic spin-orbit coupling and other time-reversal symmetry-breaking and/or sublattice parity-breaking potentials also lead to (subleading) corrections to the channel conductance.

  10. Effect of dipole polarizability on positron binding by strongly polar molecules

    International Nuclear Information System (INIS)

    Gribakin, G F; Swann, A R

    2015-01-01

    A model for positron binding to polar molecules is considered by combining the dipole potential outside the molecule with a strongly repulsive core of a given radius. Using existing experimental data on binding energies leads to unphysically small core radii for all of the molecules studied. This suggests that electron–positron correlations neglected in the simple model play a large role in determining the binding energy. We account for these by including the polarization potential via perturbation theory and non-perturbatively. The perturbative model makes reliable predictions of binding energies for a range of polar organic molecules and hydrogen cyanide. The model also agrees with the linear dependence of the binding energies on the polarizability inferred from the experimental data (Danielson et al 2009 J. Phys. B: At. Mol. Opt. Phys. 42 235203). The effective core radii, however, remain unphysically small for most molecules. Treating molecular polarization non-perturbatively leads to physically meaningful core radii for all of the molecules studied and enables even more accurate predictions of binding energies to be made for nearly all of the molecules considered. (paper)

  11. Strong gravity effects of rotating black holes: quasi-periodic oscillations

    International Nuclear Information System (INIS)

    Aliev, Alikram N; Esmer, Göksel Daylan; Talazan, Pamir

    2013-01-01

    We explore strong gravity effects of the geodesic motion in the spacetime of rotating black holes in general relativity and braneworld gravity. We focus on the description of the motion in terms of three fundamental frequencies: the orbital frequency, the radial and vertical epicyclic frequencies. For a Kerr black hole, we perform a detailed numerical analysis of these frequencies at the innermost stable circular orbits and beyond them as well as at the characteristic stable orbits, at which the radial epicyclic frequency attains its highest value. We find that the values of the epicyclic frequencies for a class of stable orbits exhibit good qualitative agreement with the observed frequencies of the twin peaks quasi-periodic oscillations (QPOs) in some black hole binaries. We also find that at the characteristic stable circular orbits, where the radial (or the vertical) epicyclic frequency has maxima, the vertical and radial epicyclic frequencies exhibit an approximate 2:1 ratio even in the case of near-extreme rotation of the black hole. Next, we perform a similar analysis of the fundamental frequencies for a rotating braneworld black hole and argue that the existence of such a black hole with a negative tidal charge, whose angular momentum exceeds the Kerr bound in general relativity, does not confront with the observations of high-frequency QPOs. (paper)

  12. Peak ground motions, effective duration of strong motions and frequency content of Iranian earthquakes

    International Nuclear Information System (INIS)

    Tehranizadeh, M.; Hamedi, F.

    2002-01-01

    The characteristics of earthquake ground motion have great influences on the response of structures to the earthquakes. Peak ground motions, duration of strong motions and frequency content are important characteristics of earthquakes, which are studied in this paper. The relation between peak ground acceleration, velocity and displacement have been taken into account and the effects of magnitude, epicentral distance and recorded duration of earthquakes on peak ground acceleration have been presented as graphs. The frequency content of ground motion can be examined by power spectral density of accel ero grams. In this study the power spectral density of the records have been determined and normalized power spectral densities are compared. There are different formulas for the smoothed power spectral density function such as Kanai-Tajimi's model. In this study, comparing with Kanai-Tajim's formula, the extreme value model is suggested for the spectral density function. This model is evaluated for accel ero grams on different soil conditions and the smoothed mean power spectral density function are determined for each soil groups. The central frequency and predominant period of earthquakes are also estimated

  13. Strong mutagenic effects of diesel engine emissions using vegetable oil as fuel.

    Science.gov (United States)

    Bünger, Jürgen; Krahl, Jürgen; Munack, Axel; Ruschel, Yvonne; Schröder, Olaf; Emmert, Birgit; Westphal, Götz; Müller, Michael; Hallier, Ernst; Brüning, Thomas

    2007-08-01

    Diesel engine emissions (DEE) are classified as probably carcinogenic to humans. In recent years every effort was made to reduce DEE and their content of carcinogenic and mutagenic polycyclic aromatic compounds. Since 1995 we observed an appreciable reduction of mutagenicity of DEE driven by reformulated or newly designed fuels in several studies. Recently, the use of rapeseed oil as fuel for diesel engines is rapidly growing among German transportation businesses and agriculture due to economic reasons. We compared the mutagenic effects of DEE from two different batches of rapeseed oil (RSO) with rapeseed methyl ester (RME, biodiesel), natural gas derived synthetic fuel (gas-to-liquid, GTL), and a reference diesel fuel (DF). The test engine was a heavy-duty truck diesel running the European Stationary Cycle. Particulate matter from the exhaust was sampled onto PTFE-coated glass fibre filters and extracted with dichloromethane in a soxhlet apparatus. The gas phase constituents were sampled as condensates. The mutagenicity of the particle extracts and the condensates was tested using the Salmonella typhimurium/mammalian microsome assay with tester strains TA98 and TA100. Compared to DF the two RSO qualities significantly increased the mutagenic effects of the particle extracts by factors of 9.7 up to 59 in tester strain TA98 and of 5.4 up to 22.3 in tester strain TA100, respectively. The condensates of the RSO fuels caused an up to factor 13.5 stronger mutagenicity than the reference fuel. RME extracts had a moderate but significant higher mutagenic response in assays of TA98 with metabolic activation and TA100 without metabolic activation. GTL samples did not differ significantly from DF. In conclusion, the strong increase of mutagenicity using RSO as diesel fuel compared to the reference DF and other fuels causes deep concern on future usage of this biologic resource as a replacement of established diesel fuels.

  14. Autler-Townes effect in a strongly driven electromagnetically induced transparency resonance

    International Nuclear Information System (INIS)

    Yang Lijun; Zhang Lianshui; Li Xiaoli; Han Li; Fu Guangsheng; Manson, Neil B.; Suter, Dieter; Wei Changjiang

    2005-01-01

    In this paper we study the nonlinear behavior of an electromagnetically induced transparency (EIT) resonance subject to a coherent driving field. The EIT is associated with a Λ three-level system where two hyperfine levels within an electronic ground state are coupled to a common excited state level by a coupling field and a probe field. In addition there is an radio-frequency (rf) field driving a hyperfine transition within the ground state. The paper contrasts two different situations. In one case the rf-driven transition shares a common level with the probed transition and in the second case it shares a common level with the coupled transition. In both cases the EIT resonance is split into a doublet and the characteristics of the EIT doublet are determined by the strength and frequency of the rf-driving field. The doublet splitting originates from the rf-field induced dynamic Stark effect and has close analogy with the Autler-Townes effect observed in three-level pump-probe spectroscopy study. The situation changes when the rf field is strong and the two cases are very different. One is analogous to two Λ three-level systems with EIT resonance associated with each. The other corresponds to a doubly driven three-level system with rf-field-induced electromagnetically induced absorption resonance. The two situations are modeled using numerical solutions of the relevant equation of motion of density matrix. In addition a physical account of their behaviors is given in terms of a dressed state picture

  15. Concordance of nuclear and mitochondrial DNA markers in detecting a founder event in Lake Clark sockeye salmon

    Science.gov (United States)

    Ramstad, Kristina M.; Woody, Carol Ann; Habicht, Chris; Sage, G. Kevin; Seeb, James E.; Allendorf, Fred W.

    2007-01-01

    Genetic bottleneck effects can reduce genetic variation, persistence probability, and evolutionary potential of populations. Previous microsatellite analysis suggested a bottleneck associated with a common founding of sock-eye salmon Oncorhynchus nerka populations of Lake Clark, Alaska, about 100 to 400 generations ago. The common foundingevent occurred after the last glacial recession and resulted in reduced allelic diversity and strong divergence of Lake Clarksockeye salmon relative to neighboring Six Mile Lake and LakeIliamna populations. Here we used two additional genetic marker types (allozymes and mtDNA) to examine these patterns further. Allozyme and mtDNA results were congruent with the microsatellite data in suggesting a common founder event in LakeClark sockeye salmon and confirmed the divergence of Lake Clarkpopulations from neighboring Six Mile Lake and Lake Iliamna populations. The use of multiple marker types provided better understanding of the bottleneck in Lake Clark. For example, the Sucker Bay Lake population had an exceptionally severe reduction in allelic diversity at microsatellite loci, but not at mtDNA. This suggests that the reduced microsatellite variation in Sucker Bay Lake fish is due to consistently smaller effective population size than other Lake Clark populations, rather than a more acute or additional bottleneck since founding. Caution is urged in using reduced heterozygosity as a measure of genetic bottleneck effects because stochastic variance among loci resulted in an overall increase in allozyme heterozygosity within bottlenecked Lake Clark populations. However, heterozygosity excess, which assesses heterozygosity relative to allelic variation, detected genetic bottleneck effects in both allozyme and microsatellite loci. 

  16. Effects of the Coulomb potential in interference patterns of strong-field holography with photoelectrons

    Science.gov (United States)

    Shvetsov-Shilovski, N. I.; Lein, M.

    2018-01-01

    Using the semiclassical two-step model for strong-field ionization we investigate the interference structures emerging in strong-field photoelectron holography, taking into account the Coulomb potential of the atomic core. For every kind of the interference pattern predicted by the three-step model, we calculate the corresponding structure in the presence of the Coulomb field, showing that the Coulomb potential modifies the interference patterns significantly.

  17. Modeling consequences of prolonged strong unpredictable stress in zebrafish: Complex effects on behavior and physiology.

    Science.gov (United States)

    Song, Cai; Liu, Bai-Ping; Zhang, Yong-Ping; Peng, Zhilan; Wang, JiaJia; Collier, Adam D; Echevarria, David J; Savelieva, Katerina V; Lawrence, Robert F; Rex, Christopher S; Meshalkina, Darya A; Kalueff, Allan V

    2018-02-02

    Chronic stress is the major pathogenetic factor of human anxiety and depression. Zebrafish (Danio rerio) have become a novel popular model species for neuroscience research and CNS drug discovery. The utility of zebrafish for mimicking human affective disorders is also rapidly growing. Here, we present a new zebrafish model of clinically relevant, prolonged unpredictable strong chronic stress (PUCS). The 5-week PUCS induced overt anxiety-like and motor retardation-like behaviors in adult zebrafish, also elevating whole-body cortisol and proinflammatory cytokines - interleukins IL-1β and IL-6. PUCS also elevated whole-body levels of the anti-inflammatory cytokine IL-10 and increased the density of dendritic spines in zebrafish telencephalic neurons. Chronic treatment of fish with an antidepressant fluoxetine (0.1mg/L for 8days) normalized their behavioral and endocrine phenotypes, as well as corrected stress-elevated IL-1β and IL-6 levels, similar to clinical and rodent data. The CNS expression of the bdnf gene, the two genes of its receptors (trkB, p75), and the gfap gene of glia biomarker, the glial fibrillary acidic protein, was unaltered in all three groups. However, PUCS elevated whole-body BDNF levels and the telencephalic dendritic spine density (which were corrected by fluoxetine), thereby somewhat differing from the effects of chronic stress in rodents. Together, these findings support zebrafish as a useful in-vivo model of chronic stress, also calling for further cross-species studies of both shared/overlapping and distinct neurobiological responses to chronic stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Effects of strong bite force on the facial vertical dimension of pembarong performers

    Directory of Open Access Journals (Sweden)

    C. Christina

    2017-06-01

    Full Text Available Background: A pembarong performer is a reog dancer who bites on a piece of wood inserted into his/her mouth in order to support a 60 kg Barongan or Dadak Merak mask. The teeth supporting this large and heavy mask are directly affected, as the strong bite force exerted during a dance could affect their vertical and sagital facial dimensions. Purpose: This study aimed to examine the influence of the bite force of pembarong performers due to their vertical and sagital facial dimensions. Methods: The study reported here involved fifteen pembarong performers and thirteen individuals with normal occlusion (with specific criteria. The bite force of these subjects was measured with a dental prescale sensor during its centric occlusion. A cephalometric variation measurement was subsequently performed on all subjects with its effects on their vertical and sagital facial dimensions being measured. Results: The bite force value of the pembarong performers was 394.3816 ± 7.68787 Newtons, while the normal occlusion was 371.7784 ± 4.77791 Newtons. There was no correlation between the bite force and the facial sagital dimension of these subjects. However, a significant correlation did exist between bite force and lower facial height/total facial height (LFH/TFH ratio (p = 0.013. Conversely, no significant correlation between bite force and posterior facial height/total facial height (PFH/TFH ratio (p = 0.785 was detected. There was an inverse correlation between bite force and LFH/TFH ratio (r = -.464. Conclusion: Bite force is directly related to the decrease in LFH/TFH ratio. Occlusal pressure exerted by the posterior teeth on the alveolar bone may increase bone density at the endosteal surface of cortical bone.

  19. Strong and nonlinear effects of fragmentation on ecosystem service provision at multiple scales

    Science.gov (United States)

    Mitchell, Matthew G. E.; Bennett, Elena M.; Gonzalez, Andrew

    2015-09-01

    Human actions, such as converting natural land cover to agricultural or urban land, result in the loss and fragmentation of natural habitat, with important consequences for the provision of ecosystem services. Such habitat loss is especially important for services that are supplied by fragments of natural land cover and that depend on flows of organisms, matter, or people across the landscape to produce benefits, such as pollination, pest regulation, recreation and cultural services. However, our quantitative knowledge about precisely how different patterns of landscape fragmentation might affect the provision of these types of services is limited. We used a simple, spatially explicit model to evaluate the potential impact of natural land cover loss and fragmentation on the provision of hypothetical ecosystem services. Based on current literature, we assumed that fragments of natural land cover provide ecosystem services to the area surrounding them in a distance-dependent manner such that ecosystem service flow depended on proximity to fragments. We modeled seven different patterns of natural land cover loss across landscapes that varied in the overall level of landscape fragmentation. Our model predicts that natural land cover loss will have strong and unimodal effects on ecosystem service provision, with clear thresholds indicating rapid loss of service provision beyond critical levels of natural land cover loss. It also predicts the presence of a tradeoff between maximizing ecosystem service provision and conserving natural land cover, and a mismatch between ecosystem service provision at landscape versus finer spatial scales. Importantly, the pattern of landscape fragmentation mitigated or intensified these tradeoffs and mismatches. Our model suggests that managing patterns of natural land cover loss and fragmentation could help influence the provision of multiple ecosystem services and manage tradeoffs and synergies between services across different human

  20. The first Dutch SDHB founder deletion in paraganglioma – pheochromocytoma patients

    Directory of Open Access Journals (Sweden)

    Devilee Peter

    2009-04-01

    Full Text Available Abstract Background Germline mutations of the tumor suppressor genes SDHB, SDHC and SDHD play a major role in hereditary paraganglioma and pheochromocytoma. These three genes encode subunits of succinate dehydrogenase (SDH, the mitochondrial tricarboxylic acid cycle enzyme and complex II component of the electron transport chain. The majority of variants of the SDH genes are missense and nonsense mutations. To date few large deletions of the SDH genes have been described. Methods We carried out gene deletion scanning using MLPA in 126 patients negative for point mutations in the SDH genes. We then proceeded to the molecular characterization of deletions, mapping breakpoints in each patient and used haplotype analysis to determine whether the deletions are due to a mutation hotspot or if a common haplotype indicated a single founder mutation. Results A novel deletion of exon 3 of the SDHB gene was identified in nine apparently unrelated Dutch patients. An identical 7905 bp deletion, c.201-4429_287-933del, was found in all patients, resulting in a frameshift and a predicted truncated protein, p.Cys68HisfsX21. Haplotype analysis demonstrated a common haplotype at the SDHB locus. Index patients presented with pheochromocytoma, extra-adrenal PGL and HN-PGL. A lack of family history was seen in seven of the nine cases. Conclusion The identical exon 3 deletions and common haplotype in nine patients indicates that this mutation is the first Dutch SDHB founder mutation. The predominantly non-familial presentation of these patients strongly suggests reduced penetrance. In this small series HN-PGL occurs as frequently as pheochromocytoma and extra-adrenal PGL.

  1. Identification of full-length transmitted/founder viruses and their progeny in primary HIV-1 infection

    Energy Technology Data Exchange (ETDEWEB)

    Korber, Bette [Los Alamos National Laboratory; Hraber, Peter [Los Alamos National Laboratory; Giorgi, Elena [Los Alamos National Laboratory; Bhattacharya, T [Los Alamos National Laboratory

    2009-01-01

    Identification of transmitted/founder virus genomes and their progeny by is a novel strategy for probing the molecular basis of HIV-1 transmission and for evaluating the genetic imprint of viral and host factors that act to constrain or facilitate virus replication. Here, we show in a cohort of twelve acutely infected subjects (9 clade B; 3 clade C), that complete genomic sequences of transmitted/founder viruses could be inferred using single genome amplification of plasma viral RNA, direct amplicon sequencing, and a model of random virus evolution. This allowed for the precise identification, chemical synthesis, molecular cloning, and biological analysis of those viruses actually responsible for productive clinical infection and for a comprehensive mapping of sequential viral genomes and proteomes for mutations that are necessary or incidental to the establishment of HIV-1 persistence. Transmitted/founder viruses were CD4 and CCR5 tropic, replicated preferentially in activated primary T-Iymphocytes but not monocyte-derived macrophages, and were effectively shielded from most heterologous or broadly neutralizing antibodies. By 3 months of infection, the evolving viral quasispecies in three subjects showed mutational fixation at only 2-5 discreet genomic loci. By 6-12 months, mutational fixation was evident at 18-27 genomic loci. Some, but not all, of these mutations were attributable to virus escape from cytotoxic Tlymphocytes or neutralizing antibodies, suggesting that other viral or host factors may influence early HIV -1 fitness.

  2. Prevalence of founder mutations in the BRCA1 and BRCA2 genes among unaffected women from the Bahamas.

    Science.gov (United States)

    Trottier, M; Lunn, J; Butler, R; Curling, D; Turnquest, T; Francis, W; Halliday, D; Royer, R; Zhang, S; Li, S; Thompson, I; Donenberg, T; Hurley, J; Akbari, M R; Narod, S A

    2016-03-01

    Population-based testing for BRCA1/2 mutations detects a high proportion of carriers not identified by cancer family history-based testing. We sought to determine whether population-based testing is an effective approach to genetic testing in the Bahamas, where 23% of women with breast cancer carry one of seven founder mutations in the BRCA1 or BRCA2 gene. We determined the prevalence of founder BRCA mutations in 1847 Bahamian women without a personal history of breast or ovarian cancer, unselected for age or family history. We found that 2.8% (20/705) of unaffected women with a family history of breast/ovarian cancer and 0.09% (1/1089) of unaffected women without a family history carry a BRCA mutation. A total of 38% of unaffected women with a known mutation in the family were found to carry the familial mutation. We previously suggested that all Bahamian women with breast or ovarian cancer be offered genetic testing. These current data suggest that additionally all unaffected Bahamian women with a family history of breast/ovarian cancer should be offered genetic testing for the founder BRCA mutations. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. A common Greenlandic Inuit BRCA1 RING domain founder mutation

    DEFF Research Database (Denmark)

    Hansen, T.v.O.; Ejlertsen, B.; Albrechtsen, Anders

    2009-01-01

    Germ-line mutations in the tumour suppressor proteins BRCA1 and BRCA2 predispose to breast and ovarian cancer. We examined 32 breast and/or ovarian cancer patients from Greenland for mutations in BRCA1 and BRCA2. Whereas no mutations were identified in 19 families, 13 families exhibited a BRCA1...... exon 3 nucleotide 234 T > G mutation, which has not previously been reported in the breast cancer information core (BIC) database. The mutation changes a conserved cysteine 39 to a glycine in the Zn(2+) site II of the RING domain, which is essential for BRCA1 ubiquitin ligase activity. Eight...... of the families had members with ovarian cancer, suggesting that the RING domain may be an ovarian cancer hotspot. By SNP array analysis, we find that all 13 families share a 4.5 Mb genomic fragment containing the BRCA1 gene, showing that the mutation originates from a founder. Finally, analysis of 1152 Inuit...

  4. [Identification and characterization of HIV-1 transmitted /founder viruses].

    Science.gov (United States)

    Zhao, Jian-yuan; Ding, Ji-wei; Mi, Ze-yun; Wei, Tao; Cen, Shan

    2015-05-01

    During the spread of human immunodeficiency virus type 1 (HIV-1) in the mucosa, the entire genetic diversity of the viruses is significantly reduced. The vast majority of HIV-1 mucosal infections are established by one or a few viruses and ultimately develop into systemic infections, thus the initial virus is called transmitted/founder virus (T/F virus). The study of T/F virus will benefit understanding its key characteristics resulting in successful viral replication in the new host body, which may provide novel strategies for the development of AIDS vaccines, pre-exposure prophylaxis and other therapeutic interventions. In this review, we summarize the discovery and evolutionary characteristics of T/F virus as well as early immune response after HIV-1 infection, which will establish the basis to explore the features of T/F viruses.

  5. Observation of strong magnetic effects in visible-infrared sum frequency generation from magnetic structures

    NARCIS (Netherlands)

    Kirilyuk, A.; Knippels, G.M.H.; van der Meer, A. F. G.; Renard, S.; Rasing, T.; Heskamp, I. R.; Lodder, J. C.

    2000-01-01

    We have observed very strong magnetization-induced changes of the infrared-visible sum-frequency generation (SFG) intensity from thin magnetic films using a free electron laser as a tunable infrared source. With the help of a magnetic grating a clear resonance is observed due to the excitation of

  6. Flavor changing strong interaction effects on top quark physics at the CERN LHC

    International Nuclear Information System (INIS)

    Ferreira, P.M.; Santos, R.; Oliveira, O.

    2006-01-01

    We perform a model independent analysis of the flavor changing strong interaction vertices relevant to the LHC. In particular, the contribution of dimension six operators to single top production in various production processes is discussed, together with possible hints for identifying signals and setting bounds on physics beyond the standard model

  7. Interference effects at photoionization of Rydberg atoms by a strong electromagnetic field

    International Nuclear Information System (INIS)

    Movsesyan, A.M.; Fedorov, M.V.

    1989-01-01

    The photoionization of Rydberg atoms in a strong electromagnetic field is considered. Degeneration of the levels with respect to the orbital moment, their Stark splitting and the possibility of resonant interaction with levels of lower energy are taken into account. The complex quasi-energies of the system, photoelectron spectrum in the limit of an infinite duration of interaction and the time dependence of the total ionization probability are found. It is shown that a narrowing of the quasi-energy levels occurs in a strong field. Against a background of the quasi- continuum the quasi-energy spectrum consists of more or less narrow levels. In this case the photoelectron spectrum acquires a multi-peak form. With increasing field strength the height of the peaks increases, whereas their width decreases. The ionization rate decreases with increasing field strength. The presence of a quasi-continuum is the cause of the partially non-exponential nature of the atomic disintegration

  8. Carrier envelope phase effects in molecular dissociation by few-cycle strong laser fields

    Energy Technology Data Exchange (ETDEWEB)

    Dimitriou, K I [Hellenic Army Academy, Department of Natural Science and Applications, Vari (Greece); Constantoudis, V [Institute of Microelectronics, NCSR ' Demokritos' , Athens (Greece); Mercouris, Th [Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens (Greece); Nicolaides, C A, E-mail: dimi@eie.g [Physics Department, National Technical University, Athens (Greece)

    2009-11-01

    Multiphoton molecular dissociation produced by few-cycle strong laser fields of mid-infrared wave lengths is studied theoretically. The dependence of the carrier envelope phase (CEP) on the photodissociation dynamics is investigated using both quantum and classical nonperturbative approaches. Our results show that dissociation is affected by the changes of the CEP. A detailed analysis shows that this dependence is sensitive to the duration and to the shape of the pulse.

  9. Effects of strong cathodic polarization of the Ni-YSZ interface

    DEFF Research Database (Denmark)

    Hansen, Karin Vels; Chen, Ming; Jacobsen, Torben

    2016-01-01

    Long-term strong cathodic polarization experiments of down to -2.4 V vs. E°(O2) of the Ni-YSZ interface were performed at 900°C in 97% H2/3% H2O on model electrodes. The Ni-YSZ interface underwent extensive changes and a large affected volume with a complex microstructure and phase distribution r...

  10. A putative founder effect for Parkinson's disease in South African ...

    African Journals Online (AJOL)

    imaging scans of the brain volumes of cortex and temporal lobe structures, and positron emission tomography scans of markers of .... Braak H, Del Tredici K, Rüb U, de Vos RAI, Jansen Steur ENH, Braak E. Staging of brain pathology related to sporadic Parkinson's disease. Neurobiol Aging 2003;24(2):197211. [http://dx.doi.

  11. Entrepreneurial Founder Effects in the Growth of Regional Clusters

    DEFF Research Database (Denmark)

    Dahl, Michael Slavensky; Pedersen, Christian Ø. R.; Dalum, Bent

    How can the growth of regional clusters be explained? This paper studies in great detail the growth of the wireless communication cluster in Northern Denmark. Unlike the dominant theories, we argue that initial success of the first firms are the main driving force behind the generation of new fir...

  12. Effect of a strong, DC-induced magnetic field on circadian singing activity of the house cricket (orthoptera:gryllidae)

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, K.C.; Bitzer, R.J.; Galliart, L. [Iowa State Univ., Ames, IA (United States)] [and others

    1995-05-01

    We investigated the effect of a strong, DC-induced electromagnetic field (EMF) on the circadian singing activity of the house cricket, Acheta domesticus (L.). Groups of 10 crickets were exposed to strong, DC-induced EMFs under two light regimes, 12:12 (L:D) h and 0:24 (L:D) h. Exposure to the strong EMF resulted in an increase in mean time per hour during which one or more crickets were singing and in number of crickets singing per hour. Correcting for phase shift during O:24 (L:D) h, the daily pattern of singing was apparently unaffected by any treatment. The greatest percentage of singing and number of crickets singing per hour occurred during actual or expected scotophase. This is the first report of an increase in insect activity during exposure to a strong DC-induced EMF.

  13. Distribution and medical impact of loss-of-function variants in the Finnish founder population.

    Directory of Open Access Journals (Sweden)

    Elaine T Lim

    2014-07-01

    Full Text Available Exome sequencing studies in complex diseases are challenged by the allelic heterogeneity, large number and modest effect sizes of associated variants on disease risk and the presence of large numbers of neutral variants, even in phenotypically relevant genes. Isolated populations with recent bottlenecks offer advantages for studying rare variants in complex diseases as they have deleterious variants that are present at higher frequencies as well as a substantial reduction in rare neutral variation. To explore the potential of the Finnish founder population for studying low-frequency (0.5-5% variants in complex diseases, we compared exome sequence data on 3,000 Finns to the same number of non-Finnish Europeans and discovered that, despite having fewer variable sites overall, the average Finn has more low-frequency loss-of-function variants and complete gene knockouts. We then used several well-characterized Finnish population cohorts to study the phenotypic effects of 83 enriched loss-of-function variants across 60 phenotypes in 36,262 Finns. Using a deep set of quantitative traits collected on these cohorts, we show 5 associations (p<5×10⁻⁸ including splice variants in LPA that lowered plasma lipoprotein(a levels (P = 1.5×10⁻¹¹⁷. Through accessing the national medical records of these participants, we evaluate the LPA finding via Mendelian randomization and confirm that these splice variants confer protection from cardiovascular disease (OR = 0.84, P = 3×10⁻⁴, demonstrating for the first time the correlation between very low levels of LPA in humans with potential therapeutic implications for cardiovascular diseases. More generally, this study articulates substantial advantages for studying the role of rare variation in complex phenotypes in founder populations like the Finns and by combining a unique population genetic history with data from large population cohorts and centralized research access to National Health

  14. The effect of regional variation of seismic wave attenuation on the strong ground motion from earthquakes

    International Nuclear Information System (INIS)

    Chung, D.H.; Bernreuter, D.L.

    1981-10-01

    Attenuation is caused by geometric spreading and absorption. Geometric spreading is almost independent of crustal geology and physiographic region, but absorption depends strongly on crustal geology and the state of the earth's upper mantle. Except for very high frequency waves, absorption does not affect ground motion at distances less than about 25 to 50 km. Thus, in the near-field zone, the attenuation in the eastern United States is similar to that in the western United States. Beyond the near field, differences in ground motion can best be accounted for by differences in attenuation caused by differences in absorption. The stress drop of eastern earthquakes may be higher than for western earthquakes of the same seismic moment, which would affect the high-frequency spectral content. But we believe this factor is of much less significance than differences in absorption in explaining the differences in ground motion between the East and the West. The characteristics of strong ground motion in the conterminous United States are discussed in light of these considerations, and estimates are made of the epicentral ground motions in the central and eastern United States. (author)

  15. A genetic cluster of patients with variant xeroderma pigmentosum with two different founder mutations.

    Science.gov (United States)

    Munford, V; Castro, L P; Souto, R; Lerner, L K; Vilar, J B; Quayle, C; Asif, H; Schuch, A P; de Souza, T A; Ienne, S; Alves, F I A; Moura, L M S; Galante, P A F; Camargo, A A; Liboredo, R; Pena, S D J; Sarasin, A; Chaibub, S C; Menck, C F M

    2017-05-01

    Xeroderma pigmentosum (XP) is a rare human syndrome associated with hypersensitivity to sunlight and a high frequency of skin tumours at an early age. We identified a community in the state of Goias (central Brazil), a sunny and tropical region, with a high incidence of XP (17 patients among approximately 1000 inhabitants). To identify gene mutations in the affected community and map the distribution of the affected alleles, correlating the mutations with clinical phenotypes. Functional analyses of DNA repair capacity and cell-cycle responses after ultraviolet exposure were investigated in cells from local patients with XP, allowing the identification of the mutated gene, which was then sequenced to locate the mutations. A specific assay was designed for mapping the distribution of these mutations in the community. Skin primary fibroblasts showed normal DNA damage removal but abnormal DNA synthesis after ultraviolet irradiation and deficient expression of the Polη protein, which is encoded by POLH. We detected two different POLH mutations: one at the splice donor site of intron 6 (c.764 +1 G>A), and the other in exon 8 (c.907 C>T, p.Arg303X). The mutation at intron 6 is novel, whereas the mutation at exon 8 has been previously described in Europe. Thus, these mutations were likely brought to the community long ago, suggesting two founder effects for this rare disease. This work describes a genetic cluster involving POLH, and, particularly unexpected, with two independent founder mutations, including one that likely originated in Europe. © 2016 British Association of Dermatologists.

  16. arXiv Strong reduction of the effective radiation length in an oriented PWO scintillator crystal

    CERN Document Server

    Bandiera, L.; Romagnoni, M.; Argiolas, N.; Bagli, E.; Ballerini, G.; Berra, A.; Brizzolani, C.; Camattari, R.; De Salvador, D.; Haurylavets, V.; Mascagna, V.; Mazzolari, A.; Prest, M.; Soldani, M.; Sytov, A.; Vallazza, E.

    We measured a considerable increase of the emitted radiation by 120 GeV/c electrons in an axially oriented lead tungstate scintillator crystal, if compared to the case in which the sample was not aligned with the beam direction. This enhancement resulted from the interaction of particles with the strong crystalline field. The data collected at the external lines of CERN SPS were critically compared to Monte Carlo simulations based on the Baier Katkov quasiclassical method, highlighting a reduction of the scintillator radiation length by a factor of five in case of beam alignment with the [001] crystal axes. As a consequence, oriented scintillator crystals may be profitably exploited to reduce the amount of material in electromagnetic calorimeters/detectors for fixed-target experiments in high-energy physics, as well as for satellite-borne gamma-telescopes in astrophysics.

  17. Effects of weak and strong localization in tunnel characteristics of contacts on HTSC base

    International Nuclear Information System (INIS)

    Revenko, Yu.V.; Svistunov, V.M.; Grigut', O.V.; Belogolovskij, M.A.; Khachaturov, A.I.

    1992-01-01

    It is found that a phenomena governed by the electronic processes in the disordered surface normal layer of material are observed in the tunnel contatcs bases on metal oxide superconductors of 1-2-3 group. Measured characteristics σ(U)=dI/dU ore determined both by contact's barrier properties and conductivity in the disordered region of metal oxides in the vicinity of a barrier. As regards high-temperature contacts σ(U) value at high temperatures us determined by the Schottky barrier and at low temperatures - by activation processes of charge transfer over strongly localized states in near-the-barrier region of the contact. Crossing over towards logarithmic dependence in the tunnel conductuvity σ(U) of low-Ohmic transitions are attributed to the occurrence of 2D state density conditions in the tunnel surface layers of metal oxides

  18. Strong control and squeezing effects of radiation states in a slab waveguide sandwiched between two omnidirectional mirrors

    NARCIS (Netherlands)

    van Driel, H.M.; Hoekstra, Hugo; Stoffer, Remco; Yudistira, D.

    The effect of sandwiching a slab waveguide in air between two omnidirectional mirrors on the local density of modes is investigated theoretically. Design aspects of such a structure are considered, and it is shown that the local density of modes other than the slab-guided mode can be strongly

  19. Survey of strong motion earthquake effects on thermal power plants in California with emphasis on piping systems. Volume 2, Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, J.D. [Stevenson and Associates, Cleveland, OH (United States)

    1995-11-01

    Volume 2 of the ``Survey of Strong Motion Earthquake Effects on Thermal Power Plants in California with Emphasis on Piping Systems`` contains Appendices which detail the detail design and seismic response of several power plants subjected to strong motion earthquakes. The particular plants considered include the Ormond Beach, Long Beach and Seal Beach, Burbank, El Centro, Glendale, Humboldt Bay, Kem Valley, Pasadena and Valley power plants. Included is a typical power plant piping specification and photographs of typical power plant piping specification and photographs of typical piping and support installations for the plants surveyed. Detailed piping support spacing data are also included.

  20. Photogeneration of neutrino and axions under stimulating effect of strong magnetic field

    CERN Document Server

    Skobelev, V V

    2001-01-01

    The processes of the neutrino and axions photoproduction on the gamma(Ze) -> gamma(nu nu-bar), gamma alpha nuclei, as well as the photon inelastic scattering on the gamma gamma -> gamma(nu nu-bar), gamma alpha photon are considered within the frames of the developed two-dimensional co-variant theory for calculating the matrix of the Feynman diagrams in the strong magnetic field. The contribution of the neutrino radiative photoproduction on the nuclei to the luminosity of the magnetic neutron stars on the early stages of their evolution may compete with the URCA-processes, because the matrix elements in the four-pole diagram depend linearly on the induction of B magnetic field by the B values approx 10 sup 3 -10 sup 4 B sub 0 (B sub 0 = m sub e sup 2 /|e| = 4.41 x 10 sup 1 sup 3 Gs). The evaluation of the axion mass upper boundary, compatible with other independent results, is obtained from the condition of the neutrino luminosity prevailing over the axion one at supposed temperature and magnetic field inducti...

  1. Transgenerational effects of mild heat in Arabidopsis thaliana show strong genotype specificity that is explained by climate at origin.

    Science.gov (United States)

    Groot, Maartje P; Kubisch, Alexander; Ouborg, N Joop; Pagel, Jörn; Schmid, Karl J; Vergeer, Philippine; Lampei, Christian

    2017-08-01

    Transgenerational environmental effects can trigger strong phenotypic variation. However, it is unclear how cues from different preceding generations interact. Also, little is known about the genetic variation for these life history traits. Here, we present the effects of grandparental and parental mild heat, and their combination, on four traits of the third-generation phenotype of 14 Arabidopsis thaliana genotypes. We tested for correlations of these effects with climate and constructed a conceptual model to identify the environmental conditions that favour the parental effect on flowering time. We observed strong evidence for genotype-specific transgenerational effects. On average, A. thaliana accustomed to mild heat produced more seeds after two generations. Parental effects overruled grandparental effects in all traits except reproductive biomass. Flowering was generally accelerated by all transgenerational effects. Notably, the parental effect triggered earliest flowering in genotypes adapted to dry summers. Accordingly, this parental effect was favoured in the model when early summer heat terminated the growing season and environments were correlated across generations. Our results suggest that A. thaliana can partly accustom to mild heat over two generations and genotype-specific parental effects show non-random evolutionary divergence across populations that may support climate change adaptation in the Mediterranean. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  2. The effect of whole body irradiation on the action of strong analgesics of mice

    International Nuclear Information System (INIS)

    Cvetkovicj, M.; Milovanovicj, A.; Tanasijevicj, D.

    1987-01-01

    The effect of whole body irradiation of male mice with single doses of 3 and 7 Gy ( 60 Co source) on analgesic action of three morphine-like drugs was studied. Over the first 6 days after irradiation, the analgesic effect of alfentanil and fentanyl was significantly less pronounced in irradiated animals than in control ones. During the subsequent period of 24 days till the end of experiment, the analgesic effect in irradiated animals gradually increased reaching and exceeding the control values. On the contrary, the analgesic effect of butorphanole was less pronounced in irradiated animals than in control ones, although the difference was not significantly. The difference between butorphanole and other two drugs are probably due to chemical structure and the metabolic fate in the body. (author) 8 refs.; 2 figs

  3. Strong-field ionization of xenon dimers: The effect of two-equivalent-center interference and of driving ionic transitions

    Science.gov (United States)

    Zhang, C.; Feng, T.; Raabe, N.; Rottke, H.

    2018-02-01

    Strong-field ionization (SFI) of the homonuclear noble gas dimer Xe2 is investigated and compared with SFI of the Xe atom and of the ArXe heteronuclear dimer by using ultrashort Ti:sapphire laser pulses and photoelectron momentum spectroscopy. The large separation of the two nuclei of the dimer allows the study of two-equivalent-center interference effects on the photoelectron momentum distribution. Comparing the experimental results with a new model calculation, which is based on the strong-field approximation, actually reveals the influence of interference. Moreover, the comparison indicates that the presence of closely spaced gerade and ungerade electronic state pairs of the Xe2 + ion at the Xe2 ionization threshold, which are strongly dipole coupled, affects the photoelectron momentum distribution.

  4. Impact of the strong electromagnetic field on the QCD effective potential for homogeneous Abelian gluon field configurations

    International Nuclear Information System (INIS)

    Galilo, Bogdan V.; Nedelko, Sergei N.

    2011-01-01

    The one-loop quark contribution to the QCD effective potential for the homogeneous Abelian gluon field in the presence of an external strong electromagnetic field is evaluated. The structure of extrema of the potential as a function of the angles between chromoelectric, chromomagnetic, and electromagnetic fields is analyzed. In this setup, the electromagnetic field is considered as an external one while the gluon field represents domain structured nonperturbative gluon configurations related to the QCD vacuum in the confinement phase. Two particularly interesting gluon configurations, (anti-)self-dual and crossed orthogonal chromomagnetic and chromoelectric fields, are discussed specifically. Within this simplified framework it is shown that the strong electromagnetic fields can play a catalyzing role for a deconfinement transition. At the qualitative level, the present consideration can be seen as a highly simplified study of an impact of the electromagnetic fields generated in relativistic heavy ion collisions on the strongly interacting hadronic matter.

  5. Perspective has a strong effect on the calculation of historical contributions to global warming

    Science.gov (United States)

    Skeie, Ragnhild B.; Fuglestvedt, Jan; Berntsen, Terje; Peters, Glen P.; Andrew, Robbie; Allen, Myles; Kallbekken, Steffen

    2017-02-01

    The politically contentious issue of calculating countries’ contributions to climate change is strongly dependent on methodological choices. Different principles can be applied for distributing efforts for reducing human-induced global warming. According to the ‘Brazilian Proposal’, industrialized countries would reduce emissions proportional to their historical contributions to warming. This proposal was based on the assumption that the political process would lead to a global top-down agreement. The Paris Agreement changed the role of historical responsibilities. Whereas the agreement refers to equity principles, differentiation of mitigation efforts is delegated to each country, as countries will submit new national contributions every five years without any international negotiation. It is likely that considerations of historical contributions and distributive fairness will continue to play a key role, but increasingly so in a national setting. Contributions to warming can be used as a background for negotiations to inform and justify positions, and may also be useful for countries’ own assessment of what constitutes reasonable and fair contributions to limiting warming. Despite the fact that the decision from COP21 explicitly rules out compensation in the context of loss and damage, it is likely that considerations of historical responsibility will also play a role in future discussions. However, methodological choices have substantial impacts on calculated contributions to warming, including rank-ordering of contributions, and thus support the view that there is no single correct answer to the question of how much each country has contributed. There are fundamental value-related and ethical questions that cannot be answered through a single set of calculated contributions. Thus, analyses of historical contributions should not present just one set of results, but rather present a spectrum of results showing how the calculated contributions vary with a

  6. Strong synergistic effects in PLA/PCL blends: Impact of PLA matrix viscosity.

    Science.gov (United States)

    Ostafinska, Aleksandra; Fortelný, Ivan; Hodan, Jiří; Krejčíková, Sabina; Nevoralová, Martina; Kredatusová, Jana; Kruliš, Zdeněk; Kotek, Jiří; Šlouf, Miroslav

    2017-05-01

    Blends of two biodegradable polymers, poly(lactic acid) (PLA) and poly(ϵ-caprolactone) (PCL), with strong synergistic improvement in mechanical performance were prepared by melt-mixing using the optimized composition (80/20) and the optimized preparation procedure (a melt-mixing followed by a compression molding) according to our previous study. Three different PLA polymers were employed, whose viscosity decreased in the following order: PLC ≈ PLA1 > PLA2 > PLA3. The blends with the highest viscosity matrix (PLA1/PCL) exhibited the smallest PCL particles (d∼0.6μm), an elastic-plastic stable fracture (as determined from instrumented impact testing) and the strongest synergistic improvement in toughness (>16× with respect to pure PLA, exceeding even the toughness of pure PCL). According to the available literature, this was the highest toughness improvement in non-compatiblized PLA/PCL blends ever achieved. The decrease in the matrix viscosity resulted in an increase in the average PCL particle size and a dramatic decrease in the overall toughness: the completely stable fracture (for PLA1/PCL) changed to the stable fracture followed by unstable crack propagation (for PLA2/PCL) and finally to the completely brittle fracture (for PLA3/PCL). The stiffness of all blends remained at well acceptable level, slightly above the theoretical predictions based on the equivalent box model. Despite several previous studies, the results confirmed that PLA and PCL could behave as compatible polymers, but the final PLA/PCL toughness is extremely sensitive to the PCL particle size distribution, which is influenced by both processing conditions and PLA viscosity. PLA/PCL blends with high stiffness (due to PLA) and toughness (due to PCL) are very promising materials for medical applications, namely for the bone tissue engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Effects of a parental program for preventing underage drinking - The NGO program strong and clear

    Directory of Open Access Journals (Sweden)

    Eriksson Charli

    2011-04-01

    Full Text Available Abstract Background The present study is an evaluation of a 3-year parental program aiming to prevent underage drinking. The intervention was implemented by a non-governmental organization and targeted parents with children aged 13-16 years old and included recurrent activities during the entire period of secondary school. The program consisted of four different types of group and self-administered activities: parent meetings, family dialogues, friend meetings, and family meetings. Methods A quasi-experimental design was used following parents and children with questionnaires during the three years of secondary school. The analytic sample consisted of 509 dyads of parents and children. Measures of parental attitudes and behaviour concerning underage drinking and adolescents' lifetime alcohol consumption and drunkenness were used. Three socio-demographic factors were included: parental education, school, and gender of the child. A Latent Growth Modelling (LGM approach was used to examine changes in parental behaviour regarding youth drinking and in young people's drinking behaviour. To test for the pre-post test differences in parental attitudes repeated measures ANOVA were used. Results The results showed that parents in the program maintained their restrictive attitude toward underage drinking to a higher degree than non-participating parents. Adolescents of participants were on average one year older than adolescents with non-participating parents when they made their alcohol debut. They were also less likely to have ever been drunk in school year 9. Conclusion The results of the study suggested that Strong and Clear contributed to maintaining parents' restrictive attitude toward underage drinking during secondary school, postponing alcohol debut among the adolescents, and significantly reducing their drunkenness.

  8. How strong is the edge effect in the adsorption of anticancer drugs on a graphene cluster?

    Science.gov (United States)

    Rungnim, Chompoonut; Chanajaree, Rungroj; Rungrotmongkol, Thanyada; Hannongbua, Supot; Kungwan, Nawee; Wolschann, Peter; Karpfen, Alfred; Parasuk, Vudhichai

    2016-04-01

    The adsorption of nucleobase-analog anticancer drugs (fluorouracil, thioguanine, and mercaptopurine) on a graphene flake (C54H18) was investigated by shifting the site at which adsorption occurs from one end of the sheet to the other end. The counterpoise-corrected M06-2X/cc-pVDZ binding energies revealed that the binding stability decreases in the sequence thioguanine > mercaptopurine > fluorouracil. We found that adsorption near the middle of the sheet is more favorable than adsorption near the edge due to the edge effect. This edge effect is stronger for the adsorption of thioguanine or mercaptopurine than for fluorouracil adsorption. However, the edge effect reduces the binding energy of the drug to the flake by only a small amount, <5 kcal/mol, depending on the adsorption site and the alignment of the drug at this site.

  9. Strong excitonic effects in CuAlO2 delafossite transparent conductive oxides

    DEFF Research Database (Denmark)

    Laskowski, Robert; Christensen, Niels Egede; Blaha, Peter

    2009-01-01

    The imaginary part of the dielectric function of CuAlO2 has been calculated including the electron-hole correlation effects within Bethe-Salpeter formalism (BSE). In the initial step of the BSE solver the band structure was calculated within density-functional theory plus an orbital field (LDA/GG...

  10. Rapid Transition of the Hole Rashba Effect from Strong Field Dependence to Saturation in Semiconductor Nanowires.

    Science.gov (United States)

    Luo, Jun-Wei; Li, Shu-Shen; Zunger, Alex

    2017-09-22

    The electric field manipulation of the Rashba spin-orbit coupling effects provides a route to electrically control spins, constituting the foundation of the field of semiconductor spintronics. In general, the strength of the Rashba effects depends linearly on the applied electric field and is significant only for heavy-atom materials with large intrinsic spin-orbit interaction under high electric fields. Here, we illustrate in 1D semiconductor nanowires an anomalous field dependence of the hole (but not electron) Rashba effect (HRE). (i) At low fields, the strength of the HRE exhibits a steep increase with the field so that even low fields can be used for device switching. (ii) At higher fields, the HRE undergoes a rapid transition to saturation with a giant strength even for light-atom materials such as Si (exceeding 100 meV Å). (iii) The nanowire-size dependence of the saturation HRE is rather weak for light-atom Si, so size fluctuations would have a limited effect; this is a key requirement for scalability of Rashba-field-based spintronic devices. These three features offer Si nanowires as a promising platform for the realization of scalable complementary metal-oxide-semiconductor compatible spintronic devices.

  11. Effect of strong electrolytes on edible oils part 1: viscosity of ...

    African Journals Online (AJOL)

    The energy of activation (ΔEv), latent heat of vapourization (ΔLv) and molar volume of oil (Vm) were also calculated. Effect of electrolytes show that, the concentration of electrolytes increases the value of (ΔEv) and (ΔLv) whereas the value of molar volume (Vm) decrease with the concentration of oil and electrolytes. In brief ...

  12. Effect of strong electrolytes on edible oils part II: vViscosity of maize ...

    African Journals Online (AJOL)

    The electrolytes behave as structure breaker. The effect of temperature was also determined in terms of fluidity parameters, energy of activation, latent heat of vaporization, molar volume of oil and free energy change of activation for viscous flow. Journal of Applied Sciences and Environmental Management Vol. 10 (3) 2006: ...

  13. Faraday effect in rare-earth ferrite garnets located in strong magnetic fields

    International Nuclear Information System (INIS)

    Valiev, U.V.; Zvezdin, A.K.; Krinchik, G.S.; Levitin, R.Z.; Mukimov, K.M.; Popov, A.I.

    1983-01-01

    The Faraday effect is investigated experimentally in single crystal specimens of rare earth iron garnets (REIG) R 3 Fe 5 O 12 (R=Y, Gd, Tb, Dy, Er, Tm, Yb, Eu, Sm and Ho) and also in mixed iron garnets Rsub(x)Ysub(3-x)Fesub(5)Osub(12) (R=Tb, Dy). The m.easurements are carried out in pulsed magnetic fields of intensity up to 200 kOe, in a temperature range from 4.2 to 300 K and at a wavelength of the light lambda=1.15 μm. The field dependence of the Faraday effect observed in the REIG cannot be explained if only the usually considered ''paramagnetic'' contribution to the Faraday effect is taken into account. A theory is developed which, besides the paramagnetic mechanism, takes into account a diamagnetic mechanism and also the mixing of the wave functions of the ground and excited multiplets. The contributions of each of these three mechanisms to the angle of rotation of the plane of polarization by the rare earth sublattice of the iron garnet are estimated theoretically. It is concluded that the mixing mechanism contributes significantly to the field and temperature dependences of the Faraday effect in REIG

  14. Effect of inter-fibre bonding on the fracture of fibrous networks with strong interactions

    DEFF Research Database (Denmark)

    Goutianos, Stergios; Mao, Rui; Peijs, Ton

    2017-01-01

    Abstract The mechanical response of cellulose nanopaper composites is investigated using a three-dimensional (3D) finite element fibrous network model with focus on the effect of inter-fibre bonds. It is found that the Young’s modulus and strength, for fixed fibre properties, are mainly controlle...

  15. Preconception carrier screening for multiple disorders: evaluation of a screening offer in a Dutch founder population

    NARCIS (Netherlands)

    Mathijssen, Inge B.; Holtkamp, Kim C. A.; Ottenheim, Cecile P. E.; van Eeten-Nijman, Janneke M. C.; Lakeman, Phillis; Meijers-Heijboer, Hanne; van Maarle, Merel C.; Henneman, Lidewij

    2018-01-01

    Technological developments have enabled carrier screening for multiple disorders. This study evaluated experiences with a preconception carrier screening offer for four recessive disorders in a Dutch founder population. Questionnaires were completed by 182 attendees pretesting and posttesting and by

  16. Drosophila Heartless acts with Heartbroken/Dof in muscle founder differentiation.

    Directory of Open Access Journals (Sweden)

    Devkanya Dutta

    2005-10-01

    Full Text Available The formation of a multi-nucleate myofibre is directed, in Drosophila, by a founder cell. In the embryo, founders are selected by Notch-mediated lateral inhibition, while during adult myogenesis this mechanism of selection does not appear to operate. We show, in the muscles of the adult abdomen, that the Fibroblast growth factor pathway mediates founder cell choice in a novel manner. We suggest that the developmental patterns of Heartbroken/Dof and Sprouty result in defining the domain and timing of activation of the Fibroblast growth factor receptor Heartless in specific myoblasts, thereby converting them into founder cells. Our results point to a way in which muscle differentiation could be initiated and define a critical developmental function for Heartbroken/Dof in myogenesis.

  17. Aristarchus Lewkowski — the founder of Saratov's Neurology (the 150th anniversary of his birth

    Directory of Open Access Journals (Sweden)

    Kolokolov O.V.

    2016-06-01

    Full Text Available The article presents the information about the life, career and scientific work of Aristarchus Lewkowski — the founder of Saratov'sNeurological science school and the creator of outpatient neurological services.

  18. Fourier heat conduction as a strong kinetic effect in one-dimensional hard-core gases

    Science.gov (United States)

    Zhao, Hanqing; Wang, Wen-ge

    2018-01-01

    For a one-dimensional (1D) momentum conserving system, intensive studies have shown that generally its heat current autocorrelation function (HCAF) tends to decay in a power-law manner and results in the breakdown of the Fourier heat conduction law in the thermodynamic limit. This has been recognized to be a dominant hydrodynamic effect. Here we show that, instead, the kinetic effect can be dominant in some cases and leads to the Fourier law for finite-size systems. Usually the HCAF undergoes a fast decaying kinetic stage followed by a long slowly decaying hydrodynamic tail. In a finite range of the system size, we find that whether the system follows the Fourier law depends on whether the kinetic stage dominates. Our Rapid Communication is illustrated by the 1D hard-core gas models with which the HCAF is derived analytically and verified numerically by molecular dynamics simulations.

  19. The Slavic NBN Founder Mutation: A Role for Reproductive Fitness?

    Directory of Open Access Journals (Sweden)

    Eva Seemanova

    Full Text Available The vast majority of patients with Nijmegen Breakage Syndrome (NBS are of Slavic origin and carry a deleterious deletion (c.657del5; rs587776650 in the NBN gene on chromosome 8q21. This mutation is essentially confined to Slavic populations and may thus be considered a Slavic founder mutation. Notably, not a single parenthood of a homozygous c.657del5 carrier has been reported to date, while heterozygous carriers do reproduce but have an increased cancer risk. These observations seem to conflict with the considerable carrier frequency of c.657del5 of 0.5% to 1% as observed in different Slavic populations because deleterious mutations would be eliminated quite rapidly by purifying selection. Therefore, we propose that heterozygous c.657del5 carriers have increased reproductive success, i.e., that the mutation confers heterozygote advantage. In fact, in our cohort study of the reproductive history of 24 NBS pedigrees from the Czech Republic, we observed that female carriers gave birth to more children on average than female non-carriers, while no such reproductive differences were observed for males. We also estimate that c.657del5 likely occurred less than 300 generations ago, thus supporting the view that the original mutation predated the historic split and subsequent spread of the 'Slavic people'. We surmise that the higher fertility of female c.657del5 carriers reflects a lower miscarriage rate in these women, thereby reflecting the role of the NBN gene product, nibrin, in the repair of DNA double strand breaks and their processing in immune gene rearrangements, telomere maintenance, and meiotic recombination, akin to the previously described role of the DNA repair genes BRCA1 and BRCA2.

  20. N.A. Bernstein, the founder of modern biomechanics

    Directory of Open Access Journals (Sweden)

    Vazha M. Devishvili

    2015-12-01

    Full Text Available The paper deals with three major periods of scientific work of Nikolai Alexandrovich Bernstein, the outstanding Russian scientist, the founder the motor activity theory of human and animal. In 2016 is the 120th anniversary of Bernstein´s birth. The first period of his scientific activity, from 1922 when Bernstein started his research at the Central Institute of Labour Protection until the middle of the 30s of the 20th century. By this time, he formulated and published the basic principles and ideas of the annular motion control and sensor correction movements of varying complexity and various performance. The second period ends with the fundamental scientific work «On the Construction of Movements» awarded by the USSR State Prize in 1948. The book sums up Bernstein´s more than twenty years of research in the field of biomechanics and physiology of movement. The paper briefly describes the main assumptions of the three chapters of the book. The first chapter «Movements» reveals the evolutionary ideas about the origin of motor function and shaped the principle of the equation of building movements. The second chapter describes five levels with different functionality in varying degrees involved in the implementation of motor actions. The third chapter of the «Development and Decay» deals with the general laws of occurrence and levels of building movements being signs of confirming the level structure of motion in pathology and standards. In 1950-60-ies of the 20th century Bernstein greatly expanded representation of the functional content and neural substrate levels of building movements, detailed the stages and phases of shaping and improvement of motor skills. The author shows the importance of scientific achievements of N.A. Bernstein for modern research in the psychophysiology of movements.

  1. Biological Maturity Status Strongly Intensifies the Relative Age Effect in Alpine Ski Racing.

    Directory of Open Access Journals (Sweden)

    Lisa Müller

    Full Text Available The relative age effect (RAE is a well-documented phenomenon in youth sports. This effect exists when the relative age quarter distribution of selected athletes shows a biased distribution with an over-representation of relatively older athletes. In alpine ski racing, it exists in all age categories (national youth levels up to World Cup. Studies so far could demonstrate that selected ski racers are relatively older, taller and heavier. It could be hypothesized that relatively younger athletes nearly only have a chance for selection if they are early maturing. However, surprisingly this influence of the biological maturity status on the RAE could not be proven, yet. Therefore, the aim of the present study was to investigate the influence of the biological maturity status on the RAE in dependence of the level of competition. The study investigated 372 elite youth ski racers: 234 provincial ski racers (P-SR; high level of competition and 137 national ski racers (N-SR; very high level of competition. Anthropometric characteristics were measured to calculate the age at peak height velocity (APHV as an indicator of the biological maturity status. A significant RAE was present among both P-SR and N-SR, with a larger effect size among the latter group. The N-SR significantly differed in APHV from the P-SR. The distribution of normal, early and late maturing athletes significantly differed from the expected normal distribution among the N-SR, not among the P-SR. Hardly any late maturing N-SR were present; 41.7% of the male and 34% of the female N-SR of the last relative age quarter were early maturing. These findings clearly demonstrate the significant influence of the biological maturity status on the selection process of youth alpine ski racing in dependence of the level of competition. Relatively younger athletes seem to have a chance of selection only if they are early maturing.

  2. Biological Maturity Status Strongly Intensifies the Relative Age Effect in Alpine Ski Racing.

    Science.gov (United States)

    Müller, Lisa; Müller, Erich; Hildebrandt, Carolin; Raschner, Christian

    2016-01-01

    The relative age effect (RAE) is a well-documented phenomenon in youth sports. This effect exists when the relative age quarter distribution of selected athletes shows a biased distribution with an over-representation of relatively older athletes. In alpine ski racing, it exists in all age categories (national youth levels up to World Cup). Studies so far could demonstrate that selected ski racers are relatively older, taller and heavier. It could be hypothesized that relatively younger athletes nearly only have a chance for selection if they are early maturing. However, surprisingly this influence of the biological maturity status on the RAE could not be proven, yet. Therefore, the aim of the present study was to investigate the influence of the biological maturity status on the RAE in dependence of the level of competition. The study investigated 372 elite youth ski racers: 234 provincial ski racers (P-SR; high level of competition) and 137 national ski racers (N-SR; very high level of competition). Anthropometric characteristics were measured to calculate the age at peak height velocity (APHV) as an indicator of the biological maturity status. A significant RAE was present among both P-SR and N-SR, with a larger effect size among the latter group. The N-SR significantly differed in APHV from the P-SR. The distribution of normal, early and late maturing athletes significantly differed from the expected normal distribution among the N-SR, not among the P-SR. Hardly any late maturing N-SR were present; 41.7% of the male and 34% of the female N-SR of the last relative age quarter were early maturing. These findings clearly demonstrate the significant influence of the biological maturity status on the selection process of youth alpine ski racing in dependence of the level of competition. Relatively younger athletes seem to have a chance of selection only if they are early maturing.

  3. Business strategy versus human resources strategy: the influence of the founder in small business

    Directory of Open Access Journals (Sweden)

    Juliana Popp Barbosa Lima

    2016-12-01

    Full Text Available Small and medium-sized businesses with familiar characteristics have been object of study in recent years, especially about the succession process, considering it is extremely critical to the longevity and sustainability of the organization. However, the figure of the founder and its impact in these organizations is less explored in academia. Thus, this article seeks to fill this gap, addressing the influences of the founder in the dissemination of business and HR strategies in these companies. Through a qualitative and quantitative research, there was a case of a single organization study seeking further analysis of the subject. The collection of qualitative data was given through an interview with semi-structured interview with the founder of the organization and the qualitative by applying a questionnaire with closed questions with officials of various hierarchical levels. It was observed that the personal values and the founding principles are permeated the organization, reflected in the mission and values of the company, as well as how the founder treats topics such as business strategy and the role of people management are decisive for inclusion and driving these topics within family-based organizations. The purpose of analyzing the spread of business strategies and human resources of the Founder has been reached. It was found that, in general, strategies portray the way of the Founder, however, the spread of these to the various hierarchical levels, demonstrates a more complex, as in the HRM.

  4. A systematic review of drug treatment of vulvodynia: evidence of a strong placebo effect.

    Science.gov (United States)

    Varella Pereira, Glaucia Miranda; Marcolino, Milena Soriano; Nogueira Reis, Zilma Silveira; de Castro Monteiro, Marilene Vale

    2018-03-23

    Vulvodynia is the most common type of chronic pelvic pain and dyspareunia in premenopausal women. The effect of drugs for the treatment of vulvodynia remains poorly discussed. To conduct a systematic review of randomised controlled studies which assess medications used to treat vulvar pain in vulvodynia. Web of Science, Cochrane Library, EBSCO Academic, LILACS and MEDLINE were searched from 1985 to September 2016. Randomised controlled trials comparing any kind of medication for vulvodynia treatment with placebo or with another medication in adult patients were included. The two investigators independently conducted data extraction. The synthesis was provided by the pain reduction index. Study quality assessment was performed using the Cochrane Handbook for Systematic Reviews of Intervention and analysis of publication bias was conducted. Five studies were included in qualitative synthesis with a number of the participants varied from 30 to 133 among the eligible studies resulting 297. The pain reduction rates of patients with vulvodynia assessed by Q-tipped Cotton Test and visual analogue scale varied between studies. Placebo was shown to be as effective as any medication. There is a need for further studies evaluating topical monotherapy for the treatment of vulvodynia, since they are the main drugs used in clinical practice. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  5. <strong>Dimensional asymptotics of effective actions on S^n, and proof of Bär-Schopka's conjecturestrong>

    DEFF Research Database (Denmark)

    Møller, Niels Martin

    We study the dimensional asymptotics of the effective actions, or functional determinants, for the Dirac operator D and Laplacians \\Delta +\\beta R on round S^n. For Laplacians the behavior depends on ``the coupling strength'' \\beta, and one cannot in general expect a finite limit of \\zeta'(0), an...... spheres to unit volume, since \\lim_{k\\to\\infty}\\det(\\Delta, S_\\mathrm{rescaled}^{2k+1})=\\frac{1}{2\\pi e}....

  6. Effects of strong network modifiers on Fe3+/Fe2+ in silicate melts: an experimental study

    Science.gov (United States)

    Borisov, Alexander; Behrens, Harald; Holtz, Francois

    2017-05-01

    The effect of CaO, Na2O, and K2O on ferric/ferrous ratio in model multicomponent silicate melts was investigated in the temperature range 1450-1550 °C at 1-atm total pressure in air. It is demonstrated that the addition of these network modifier cations results in an increase of Fe3+/Fe2+ ratio. The influence of network modifier cations on the ferric/ferrous ratio increases in the order Ca SiO2-TiO2-Al2O3-FeO-Fe2O3-MgO-CaO-Na2O-K2O-P2O5 melts at air conditions.

  7. In-medium covariant propagator of baryons under a strong magnetic field: Effect of the intrinsic magnetic moments

    Energy Technology Data Exchange (ETDEWEB)

    Aguirre, R.M.; Paoli, A.L. de [Universidad Nacional de La Plata, and IFLP, Departamento de Fisica, Facultad de Ciencias Exactas, La Plata (Argentina)

    2016-11-15

    We obtain the covariant propagator at finite temperature for interacting baryons immersed in a strong magnetic field. The effect of the intrinsic magnetic moments on the Green function are fully taken into account. We make an expansion in terms of eigenfunctions of a Dirac field, which leads us to a compact form of its propagator. We present some simple applications of these propagators, where the statistical averages of nuclear currents and energy density are evaluated. (orig.)

  8. Absence of strong strain effects in behavioral analyses of Shank3-deficient mice

    Directory of Open Access Journals (Sweden)

    Elodie Drapeau

    2014-06-01

    Full Text Available Haploinsufficiency of SHANK3, caused by chromosomal abnormalities or mutations that disrupt one copy of the gene, leads to a neurodevelopmental syndrome called Phelan-McDermid syndrome, symptoms of which can include absent or delayed speech, intellectual disability, neurological changes and autism spectrum disorders. The SHANK3 protein forms a key structural part of the post-synaptic density. We previously generated and characterized mice with a targeted disruption of Shank3 in which exons coding for the ankyrin-repeat domain were deleted and expression of full-length Shank3 was disrupted. We documented specific deficits in synaptic function and plasticity, along with reduced reciprocal social interactions, in Shank3 heterozygous mice. Changes in phenotype owing to a mutation at a single locus are quite frequently modulated by other loci, most dramatically when the entire genetic background is changed. In mice, each strain of laboratory mouse represents a distinct genetic background and alterations in phenotype owing to gene knockout or transgenesis are frequently different across strains, which can lead to the identification of important modifier loci. We have investigated the effect of genetic background on phenotypes of Shank3 heterozygous, knockout and wild-type mice, using C57BL/6, 129SVE and FVB/Ntac strain backgrounds. We focused on observable behaviors with the goal of carrying out subsequent analyses to identify modifier loci. Surprisingly, there were very modest strain effects over a large battery of analyses. These results indicate that behavioral phenotypes associated with Shank3 haploinsufficiency are largely strain-independent.

  9. Effects of strong electron correlations in Ti8C12 Met-Car

    International Nuclear Information System (INIS)

    Varganov, Sergey A.; Gordon, Mark S.

    2006-01-01

    The results of multireference configuration interaction (MRCI) with single and double excitations and single reference coupled cluster (CCSD(T)) calculations on Ti 8 C 12 metallocarbohedryne (Met-Car) are reported. The distortions of the T d structure to D 2d and C 3v structures due to the Jahn-Teller effect are studied. It is shown that the Ti 8 C 12 wave function has significant multireference character. The choice of the active space for multireference self-consistent field (MCSCF) calculations is discussed. The failure of multireference perturbation theory with a small active space is attributed to multiple intruder states. A new, novel type of MCSCF calculation, ORMAS (occupation restricted multiple active spaces) with a large active space are carried out for several electronic states of Ti 8 C 12 . The Jahn-Teller distorted D 2d 1 A 1 (nearly T d ) structure is predicted to be the Ti 8 C 12 ground state. Predictions of the Ti 8 C 12 ionization potential with different ab initio methods are presented

  10. Noise-induced effects on multicellular biopacemaker spontaneous activity: Differences between weak and strong pacemaker cells

    Science.gov (United States)

    Aghighi, Alireza; Comtois, Philippe

    2017-09-01

    Self-organization of spontaneous activity of a network of active elements is important to the general theory of reaction-diffusion systems as well as for pacemaking activity to initiate beating of the heart. Monolayer cultures of neonatal rat ventricular myocytes, consisting of resting and pacemaker cells, exhibit spontaneous activation of their electrical activity. Similarly, one proposed approach to the development of biopacemakers as an alternative to electronic pacemakers for cardiac therapy is based on heterogeneous cardiac cells with resting and spontaneously beating phenotypes. However, the combined effect of pacemaker characteristics, density, and spatial distribution of the pacemaker cells on spontaneous activity is unknown. Using a simple stochastic pattern formation algorithm, we previously showed a clear nonlinear dependency of spontaneous activity (occurrence and amplitude of spontaneous period) on the spatial patterns of pacemaker cells. In this study, we show that this behavior is dependent on the pacemaker cell characteristics, with weaker pacemaker cells requiring higher density and larger clusters to sustain multicellular activity. These multicellular structures also demonstrated an increased sensitivity to voltage noise that favored spontaneous activity at lower density while increasing temporal variation in the period of activity. This information will help researchers overcome the current limitations of biopacemakers.

  11. <strong>EFFECTS OF HYALURONAN ON THREE-DIMENSIONAL MICROARCHITECTURE OF SUBCHONDRAL BONE TISSUES IN GUINEA PIG PRIMARY OSTEOARTHROSISstrong>

    DEFF Research Database (Denmark)

    Ding, Ming

    ; and the control groups received vehicle. After sacrifice, the left tibiae were harvested and micro-CT scanned, followed by mechanical testing and collagen and mineral determination. Results: The HA-treated groups had almost normal cartilage, whereas the control groups had typical osteoarthrosis (OA......-term study, these latter changes were more pronounced, with an additionally significant decrease in connectivity and bone surface density. HA groups had greater bone mineral concentration and mineral density, lower collagen to mineral ratio, and preserved the mechanical properties of cancellous bone...... level, and effectively changes the subchondral bone tissue microarchitecture, collagen and mineral content and density without altering the mechanical properties of cancellous bone. The most striking features are the microarchitectural changes in the subchondral cancellous bone that lead to lower bone...

  12. A Solar Eruption from a Weak Magnetic Field Region with Relatively Strong Geo-Effectiveness

    Science.gov (United States)

    Wang, R.

    2017-12-01

    A moderate flare eruption giving rise to a series of geo-effectiveness on 2015 November 4 caught our attentions, which originated from a relatively weak magnetic field region. The associated characteristics near the Earth are presented, which indicates that the southward magnetic field in the sheath and the ICME induced a geomagnetic storm sequence with a Dst global minimum of 90 nT. The ICME is indicated to have a small inclination angle by using a Grad-Shafranov technique, and corresponds to the flux rope (FR) structure horizontally lying on the solar surface. A small-scale magnetic cancelling feature was detected which is beneath the FR and is co-aligned with the Atmospheric Imaging Assembly (AIA) EUV brightening prior to the eruption. Various magnetic features for space-weather forecasting are computed by using a data product from the Helioseismic and Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) called Space-weather HMI Active Region Patches (SHARPs), which help us identify the changes of the photospheric magnetic fields during the magnetic cancellation process and prove that the magnetic reconnection associated with the flux cancellation is driven by the magnetic shearing motion on the photosphere. An analysis on the distributions at different heights of decay index is carried out. Combining with a filament height estimation method, the configurations of the FR is identified and a decay index critical value n = 1 is considered to be more appropriate for such a weak magnetic field region. Through a comprehensive analysis to the trigger mechanisms and conditions of the eruption, a clearer scenario of a CME from a relatively weak region is presented.

  13. Maturity Status Strongly Influences the Relative Age Effect in International Elite Under-9 Soccer

    Directory of Open Access Journals (Sweden)

    Lisa Müller, Josef Gehmaier, Christoph Gonaus, Christian Raschner, Erich Müller

    2018-06-01

    Full Text Available The aim of the study was to assess the role of the relative age effect (RAE and to investigate the influence of the biological maturity status on the RAE in international under-9 soccer. The birth dates of 222 male participants of the U9 Eurochampionship Soccer Tournament in Vienna in 2016 were analyzed and divided into four relative age quarters (Q1-Q4 and the biological maturity status was assessed with the age at peak height velocity (APHV method. Based on the mean±standard deviation of the APHV, the athletes were divided into three groups of maturity: early, normal and late maturing. Chi-Square-tests were used to assess the difference between the observed and the expected even relative age quarter distribution and to evaluate the difference between the observed distribution of early, normal and late maturing athletes and the expected normal distribution. A univariate analysis of variance was performed to assess differences in the APHV between the relative age quarters. A RAE was present (χ2 = 23.87; p < 0.001; ω = 0.33. A significant difference was found in APHV between the four relative age quarters (F = 9.906; p < 0.001; relatively older athletes were significantly less mature. A significant difference was found between the distribution of early, normal and late maturing athletes and the expected normal distribution for athletes of Q1 (high percentage of late maturing athletes: 27%; χ2 = 17.69; p < 0.001; ω = 0.46 and of Q4 (high percentage of early maturing soccer players: 31%; χ2 = 12.08; p = 0.002; ω = 0.58. These findings demonstrated that the selection process in international soccer, with athletes younger than 9 years, seems to be associated with the biological maturity status and the relative age. Relatively younger soccer players seem to have a better chance for selection for international tournaments, if they enter puberty at an earlier age, whereas relatively older athletes seem to have an increased likelihood for

  14. Self-assembly of a novel beta-In2S3 nanostructure exhibiting strong quantum confinement effects.

    Science.gov (United States)

    Zhang, Wu; Ma, Dekun; Huang, Zhen; Tang, Qun; Xie, Qin; Qian, Yitai

    2005-05-01

    The 3D beta-In2S3 flowerlike architecture assembled from nanoflakes was prepared via a novel complex-precursor assisted (CPA) solvothermal route. The as-prepared beta-In2S3 powder was characterized by X-ray diffraction pattern (XRD), X-ray photoelectron spectra (XPS), transition electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), ultraviolet-visible light (UV-vis) spectra, and photoluminescence spectrum. The novel 3D beta-In2S3 nanostructure exhibit a strong quantum confinement effect. FT-IR spectra were used to investigate the coordinative chemical effect in the complex. A possible mechanism was discussed.

  15. Hall effect in a strong magnetic field: Direct comparisons of compressible magnetohydrodynamics and the reduced Hall magnetohydrodynamic equations

    International Nuclear Information System (INIS)

    Martin, L. N.; Dmitruk, P.; Gomez, D. O.

    2010-01-01

    In this work we numerically test a model of Hall magnetohydrodynamics in the presence of a strong mean magnetic field: the reduced Hall magnetohydrodynamic model (RHMHD) derived by [Gomez et al., Phys. Plasmas 15, 102303 (2008)] with the addition of weak compressible effects. The main advantage of this model lies in the reduction of computational cost. Nevertheless, up until now the degree of agreement with the original Hall MHD system and the range of validity in a regime of turbulence were not established. In this work direct numerical simulations of three-dimensional Hall MHD turbulence in the presence of a strong mean magnetic field are compared with simulations of the weak compressible RHMHD model. The results show that the degree of agreement is very high (when the different assumptions of RHMHD, such as spectral anisotropy, are satisfied). Nevertheless, when the initial conditions are isotropic but the mean magnetic field is maintained strong, the results differ at the beginning but asymptotically reach a good agreement at relatively short times. We also found evidence that the compressibility still plays a role in the dynamics of these systems, and the weak compressible RHMHD model is able to capture these effects. In conclusion the weak compressible RHMHD model is a valid approximation of the Hall MHD turbulence in the relevant physical context.

  16. Effect of Non Submerged Vanes on Separation Zone at Strongly-curved Channel Bends, a Laboratory Scale Study

    Directory of Open Access Journals (Sweden)

    Ali Akbar Akhtari

    2010-03-01

    Full Text Available Bends along open channels always pose difficulties for water transfer systems. One undesirable effect of bends in such channels, i.e. separation of water from inner banks, was studied. For the purposes of this study, the literature on the subject was first reviewed, and a strongly-curved open channel was designed and constructed on the laboratory scale. Several tests were performed to evaluate the accuracy of the lab model, data homogeneity, and systematic errors. The model was then calibrated and the influence of curvature on flow pattern past the curve was investigated. Also, for the first time, the influence of separation walls on flow pattern was investigated. Experimental results on three strongly-curved open channels with a curvature radius to channel width ratio of 1.5 and curvature angles of 30°, 60°, and 90° showed that, in all the cases studied, the effect of flow separation could be observed immediately after the curve. In addition, the greatest effect of flow separation was seen at a distance equal to channel width from the bend end. In the presence of middle walls and flow separation, the effect of water separation reduced at the bend, especially for a curvature of 90°.

  17. Finite-size effect of η-deformed AdS5×S5 at strong coupling

    Directory of Open Access Journals (Sweden)

    Changrim Ahn

    2017-04-01

    Full Text Available We compute Lüscher corrections for a giant magnon in the η-deformed (AdS5×S5η using the su(2|2q-invariant S-matrix at strong coupling and compare with the finite-size effect of the corresponding string state, derived previously. We find that these two results match and confirm that the su(2|2q-invariant S-matrix is describing world-sheet excitations of the η-deformed background.

  18. Finite-size effect of η-deformed AdS5 × S5 at strong coupling

    Science.gov (United States)

    Ahn, Changrim

    2017-04-01

    We compute Lüscher corrections for a giant magnon in the η-deformed (AdS5×S5)η using the su(2 | 2) q-invariant S-matrix at strong coupling and compare with the finite-size effect of the corresponding string state, derived previously. We find that these two results match and confirm that the su(2 | 2) q-invariant S-matrix is describing world-sheet excitations of the η-deformed background.

  19. On foundering lithosphere and volatile migration: Upside-down melting

    Science.gov (United States)

    Elkins-Tanton, L.

    2007-12-01

    On Earth magmatism occurs on continents in the absence of subduction, often producing volatile-rich magmas such as those in the Leucite Hills, the Sierra Nevada, and Peru's Altiplano. The primary hypothesis to explain this volcanism is foundering of the lower lithosphere into the mantle. Here loss of the lower lithosphere is hypothesized to occur in a ductile manner in response to a density contrast such as would be caused by intruding mantle melts that freeze as eclogites. This mechanism requires no specific structural weakness beyond a dense region in the lithosphere that is gravitationally unstable with respect to the underlying mantle and that possesses a rheology conducive to flow. Density contrasts of as little as 1% are fully sufficient to drive gravitational instabilities. A gravitational instability forms when a perturbation in a boundary grows through lateral flow, causing the perturbation to grow. The growing instability begins to sink into the underlying mantle material as a drip, exactly analogous to but reversed in the sense of growth from an ascending plume head. The unstable material will sink more rapidly than lateral flow in the lower lithosphere can continue to add material to it, resulting in an annulus of thinned lithosphere centered on the instability. Thus the lithosphere is thinned slightly in the region around the drip, but no dome forms in the lower lithosphere during ductile delamination. Traditionally magmatism associated with instabilities has been attributed to return flow of the asthenosphere into such a dome, but maintaining a dome in the lithosphere requires unusual rheological conditions not expected in such a setting. Any volatile content in the sinking material may act in petrologically significant ways. The sinking lower lithosphere may contain 0.1 to 0.2 mass% of water if only nominally anhydrous minerals are present, and up to several weight percent of water if phlogopite or amphibole are present. The sinking lithospheric

  20. A Founder Large Deletion Mutation in Xeroderma Pigmentosum-Variant Form in Tunisia: Implication for Molecular Diagnosis and Therapy

    Directory of Open Access Journals (Sweden)

    Mariem Ben Rekaya

    2014-01-01

    Full Text Available Xeroderma pigmentosum Variant (XP-V form is characterized by a late onset of skin symptoms. Our aim is the clinical and genetic investigations of XP-V Tunisian patients in order to develop a simple tool for early diagnosis. We investigated 16 suspected XP patients belonging to ten consanguineous families. Analysis of the POLH gene was performed by linkage analysis, long range PCR, and sequencing. Genetic analysis showed linkage to the POLH gene with a founder haplotype in all affected patients. Long range PCR of exon 9 to exon 11 showed a 3926 bp deletion compared to control individuals. Sequence analysis demonstrates that this deletion has occurred between two Alu-Sq2 repetitive sequences in the same orientation, respectively, in introns 9 and 10. We suggest that this mutation POLH NG_009252.1: g.36847_40771del3925 is caused by an equal crossover event that occurred between two homologous chromosomes at meiosis. These results allowed us to develop a simple test based on a simple PCR in order to screen suspected XP-V patients. In Tunisia, the prevalence of XP-V group seems to be underestimated and clinical diagnosis is usually later. Cascade screening of this founder mutation by PCR in regions with high frequency of XP provides a rapid and cost-effective tool for early diagnosis of XP-V in Tunisia and North Africa.

  1. A founder large deletion mutation in Xeroderma pigmentosum-Variant form in Tunisia: implication for molecular diagnosis and therapy.

    Science.gov (United States)

    Ben Rekaya, Mariem; Laroussi, Nadia; Messaoud, Olfa; Jones, Mariem; Jerbi, Manel; Naouali, Chokri; Bouyacoub, Yosra; Chargui, Mariem; Kefi, Rym; Fazaa, Becima; Boubaker, Mohamed Samir; Boussen, Hamouda; Mokni, Mourad; Abdelhak, Sonia; Zghal, Mohamed; Khaled, Aida; Yacoub-Youssef, Houda

    2014-01-01

    Xeroderma pigmentosum Variant (XP-V) form is characterized by a late onset of skin symptoms. Our aim is the clinical and genetic investigations of XP-V Tunisian patients in order to develop a simple tool for early diagnosis. We investigated 16 suspected XP patients belonging to ten consanguineous families. Analysis of the POLH gene was performed by linkage analysis, long range PCR, and sequencing. Genetic analysis showed linkage to the POLH gene with a founder haplotype in all affected patients. Long range PCR of exon 9 to exon 11 showed a 3926 bp deletion compared to control individuals. Sequence analysis demonstrates that this deletion has occurred between two Alu-Sq2 repetitive sequences in the same orientation, respectively, in introns 9 and 10. We suggest that this mutation POLH NG_009252.1: g.36847_40771del3925 is caused by an equal crossover event that occurred between two homologous chromosomes at meiosis. These results allowed us to develop a simple test based on a simple PCR in order to screen suspected XP-V patients. In Tunisia, the prevalence of XP-V group seems to be underestimated and clinical diagnosis is usually later. Cascade screening of this founder mutation by PCR in regions with high frequency of XP provides a rapid and cost-effective tool for early diagnosis of XP-V in Tunisia and North Africa.

  2. Strong diffusion effect of charm quarks on J/ψ production in Pb-Pb collisions at the LHC

    Science.gov (United States)

    Zhao, Jiaxing; Chen, Baoyi

    2018-01-01

    We study the J / ψ production based on coalescence model at √{sNN } = 2.76 and 5.02 TeV Pb-Pb collisions. With the colliding energy increasing from 2.76 TeV to 5.02 TeV, the number of charm pairs is enhanced by more than 50%. However, the ratio of J / ψ inclusive nuclear modification factors RAA5.02 TeV / RAA2.76 TeV is only about 1.1 ∼ 1.2. We find that the regeneration of J / ψ is proportional to the densities of charm and anti-charm quarks, instead of their total numbers. The charm quark density is diluted by the strong expansion of quark gluon plasma, which suppresses the combination probability of heavy quarks and J / ψ regeneration. This effect is more important in higher colliding energies where QGP expansion is strong. We also propose the ratio NJ/ψ /(Nc) 2 as a measurement of c and c bar coalescence probability, which is only affected by the heavy quark diffusions in QGP, and does not depend on the inputs such as cold nuclear matter effects and cross sections of charm quark production. Further more, we give the predictions at the energy of Future Circular Collider (√{sNN } = 39 TeV).

  3. Strong and Nonspecific Synergistic Antibacterial Efficiency of Antibiotics Combined with Silver Nanoparticles at Very Low Concentrations Showing No Cytotoxic Effect.

    Science.gov (United States)

    Panáček, Aleš; Smékalová, Monika; Kilianová, Martina; Prucek, Robert; Bogdanová, Kateřina; Večeřová, Renata; Kolář, Milan; Havrdová, Markéta; Płaza, Grażyna Anna; Chojniak, Joanna; Zbořil, Radek; Kvítek, Libor

    2015-12-28

    The resistance of bacteria towards traditional antibiotics currently constitutes one of the most important health care issues with serious negative impacts in practice. Overcoming this issue can be achieved by using antibacterial agents with multimode antibacterial action. Silver nano-particles (AgNPs) are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with traditional antibiotics in order to improve their antibacterial action. In this work, a systematic study quantifying the synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was performed. Employing the microdilution method as more suitable and reliable than the disc diffusion method, strong synergistic effects were shown for all tested antibiotics combined with AgNPs at very low concentrations of both antibiotics and AgNPs. No trends were observed for synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs, indicating non-specific synergistic effects. Moreover, a very low amount of silver is needed for effective antibacterial action of the antibiotics, which represents an important finding for potential medical applications due to the negligible cytotoxic effect of AgNPs towards human cells at these concentration levels.

  4. Strong and Nonspecific Synergistic Antibacterial Efficiency of Antibiotics Combined with Silver Nanoparticles at Very Low Concentrations Showing No Cytotoxic Effect

    Directory of Open Access Journals (Sweden)

    Aleš Panáček

    2015-12-01

    Full Text Available The resistance of bacteria towards traditional antibiotics currently constitutes one of the most important health care issues with serious negative impacts in practice. Overcoming this issue can be achieved by using antibacterial agents with multimode antibacterial action. Silver nano-particles (AgNPs are one of the well-known antibacterial substances showing such multimode antibacterial action. Therefore, AgNPs are suitable candidates for use in combinations with traditional antibiotics in order to improve their antibacterial action. In this work, a systematic study quantifying the synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus was performed. Employing the microdilution method as more suitable and reliable than the disc diffusion method, strong synergistic effects were shown for all tested antibiotics combined with AgNPs at very low concentrations of both antibiotics and AgNPs. No trends were observed for synergistic effects of antibiotics with different modes of action and different chemical structures in combination with AgNPs, indicating non-specific synergistic effects. Moreover, a very low amount of silver is needed for effective antibacterial action of the antibiotics, which represents an important finding for potential medical applications due to the negligible cytotoxic effect of AgNPs towards human cells at these concentration levels.

  5. [HUGO STEINHAUS--CO-FOUNDER OF THE LWÓW SCHOOL OF MATHEMATICS].

    Science.gov (United States)

    Wócik, Wiesław

    2014-01-01

    The paper is dedicated to the presentation of professor Hugo Steinhaus--co-founder of the Lwów School of Mathematics. It is indicated that had it not been for the scholar, the founding and development of the Lwów School of Mathematics would have been almost impossible. The analyses focus on his undertakings during the Lvov period in the early 1920s and those events that preceded the founding of the school (namely Steinhaus's education at the Göttingen University, various meetings and gatherings, discussions, first fascinations and mathematical dissertations). This paper, however, does not look into the scientific output of Steinhaus, only presents his method of scientific work and highlights the strategy that he chose in order to create the scientific community. An attempt has been also made to justify the effectiveness of the adopted strategy by describing the scientific atmosphere of Lvov and intellectual potential of the students of the school. Steinhaus's activities in the 1930s will be only marginally presented with an impact on particularly interesting cooperation with the alumni of the Lwów School of Mathematics--Marek Kac, Stefan Kaczmarz, Paweł Nikliborec and scholars from other fields of science (as part of the process of the application of mathematics).

  6. Use of Dried Blood Spots to Elucidate Full-Length Transmitted/Founder HIV-1 Genomes

    Directory of Open Access Journals (Sweden)

    Jesus F. Salazar-Gonzalez

    2016-07-01

    Full Text Available Background: Identification of HIV-1 genomes responsible for establishing clinical infection in newly infected individuals is fundamental to prevention and pathogenesis research. Processing, storage, and transportation of the clinical samples required to perform these virologic assays in resource-limited settings requires challenging venipuncture and cold chain logistics. Here, we validate the use of dried-blood spots (DBS as a simple and convenient alternative to collecting and storing frozen plasma. Methods: We performed parallel nucleic acid extraction, single genome amplification (SGA, next generation sequencing (NGS, and phylogenetic analyses on plasma and DBS. Results: We demonstrated the capacity to extract viral RNA from DBS and perform SGA to infer the complete nucleotide sequence of the transmitted/founder (TF HIV-1 envelope gene and full-length genome in two acutely infected individuals. Using both SGA and NGS methodologies, we showed that sequences generated from DBS and plasma display comparable phylogenetic patterns in both acute and chronic infection. SGA was successful on samples with a range of plasma viremia, including samples as low as 1,700 copies/ml and an estimated ~50 viral copies per blood spot. Further, we demonstrated reproducible efficiency in gp160 env sequencing in DBS stored at ambient temperature for up to three weeks or at -20ºC for up to five months. Conclusions: These findings support the use of DBS as a practical and cost-effective alternative to frozen plasma for clinical trials and translational research conducted in resource-limited settings.

  7. Novel siRNA delivery system using a ternary polymer complex with strong silencing effect and no cytotoxicity.

    Science.gov (United States)

    Kodama, Yukinobu; Shiokawa, Yumi; Nakamura, Tadahiro; Kurosaki, Tomoaki; Aki, Keisei; Nakagawa, Hiroo; Muro, Takahiro; Kitahara, Takashi; Higuchi, Norihide; Sasaki, Hitoshi

    2014-01-01

    We developed a novel small interfering RNA (siRNA) delivery system using a ternary complex with polyethyleneimine (PEI) and γ-polyglutamic acid (γ-PGA), which showed silencing effect and no cytotoxicity. The binary complexes of siRNA with PEI were approximately 73-102 nm in particle size and 45-52 mV in ζ-potential. The silencing effect of siRNA/PEI complexes increased with an increase of PEI, and siRNA/PEI complexes with a charge ratio greater than 16 showed significant luciferase knockdown in a mouse colon carcinoma cell line regularly expressing luciferase (Colon26/Luc cells). However, strong cytotoxicity and blood agglutination were observed in the siRNA/Lipofectamine complex and siRNA/PEI16 complex. Recharging cationic complexes with an anionic compound was reported to be a promising method for overcoming these toxicities. We therefore prepared ternary complexes of siRNA with PEI (charge ratio 16) by the addition of γ-PGA to reduce cytotoxicity and deliver siRNA. As expected, the cytotoxicity of the ternary complexes decreased with an increase of γ-PGA content, which decreased the ζ-potential of the complexes. A strong silencing effect comparable to siRNA/Lipofectamine complex was discovered in ternary complexes including γ-PGA with an anionic surface charge. The high incorporation of ternary complexes into Colon26/Luc cells was confirmed with fluorescence microcopy. Having achieved knockdown of an exogenously transfected gene, the ability of the complex to mediate knockdown of an endogenous housekeeping gene, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), was assessed in B16-F10 cells. The ternary complex (siRNA/PEI16/γ-PGA12 complex) exhibited a significant GAPDH knockdown effect. Thus, we developed a useful siRNA delivery system.

  8. Prevalence and impact of founder mutations in hereditary breast cancer in Latin America

    Directory of Open Access Journals (Sweden)

    Patricia Ashton-Prolla

    2014-01-01

    Full Text Available Approximately 10% of all cancers are considered hereditary and are primarily caused by germline, high penetrance mutations in cancer predisposition genes. Although most cancer predisposition genes are considered molecularly heterogeneous, displaying hundreds of different disease-causing sequence alterations, founder mutations have been identified in certain populations. In some Latin American countries, founder mutations associated with increased risk of breast and other cancers have been described. This is particularly interesting considering that in most of these countries, populations are highly admixed with genetic contributions from native populations and from the influx of several distinct populations of immigrants. In this article, we present a review of the scientific literature on the subject and describe current data available on founder mutations described in the most common breast cancer predisposition genes: BRCA1, BRCA2 and TP53.

  9. Fit and Strong! Plus: design of a comparative effectiveness evaluation of a weight management program for older adults with osteoarthritis.

    Science.gov (United States)

    Smith-Ray, Renae L; Fitzgibbon, Marian L; Tussing-Humphreys, Lisa; Schiffer, Linda; Shah, Amy; Huber, Gail M; Braunschweig, Carol; Campbell, Richard T; Hughes, Susan L

    2014-03-01

    Osteoarthritis (OA) is the most common chronic condition and principal cause of disability among older adults. The current obesity epidemic has contributed to this high prevalence rate. Fortunately both OA symptoms and obesity can be ameliorated through lifestyle modifications. Physical activity (PA) combined with weight management improves physical function among obese persons with knee OA but evidence-based interventions that combine PA and weight management are limited for this population. This paper describes a comparative effectiveness trial testing an evidence-based PA program for adults with lower extremity (LE) OA, Fit and Strong!, against an enhanced version that also addresses weight management based on the evidence-based Obesity Reduction Black Intervention Trial (ORBIT). Adult participants (n=400) with LE OA, age 60+, overweight/obese, and not meeting PA requirements of ≥ 150 min per week, are randomized to one of the two programs. Both 8-week interventions meet 3 times per week and include 60 min of strength, flexibility, and aerobic exercise instruction followed by 30 min of education/group discussion. The Fit and Strong! education sessions focus on using PA to manage OA; whereas Fit and Strong! Plus addresses PA and weight loss management strategies. Maintenance of behavior change is reinforced in both groups during months 3-24 through telephone calls and mailed newsletters. Outcomes are assessed at baseline, and 2, 6, 12, 18, and 24 months. Primary outcomes are dietary change at 2 months followed by weight loss at 6 months that is maintained at 24 months. Secondary outcomes assess PA, physical performance, and anxiety/depression. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. [Effects of post-anthesis irrigation frequency on the grain quality of strong gluten winter wheat cultivars].

    Science.gov (United States)

    Yao, Feng-juan; He, Ming-rong; Li, Fei; Xu, Liang-liang; Huang, Chuan-hua; Qu, Mu

    2008-12-01

    In order to investigate the effects of post-anthesis irrigation frequency on the grain quality of strong gluten winter wheat, two cultivars Jimai 20 and Gaocheng 8901 were subjected to a series of irrigation frequencies under rainfall proof conditions, with their grain yield and grain quality (farinograph parameters and loaf volume) and protein composition evaluated. The results indicated that with increasing irrigation frequency, the grain yield of the two cultivars, their wheat flour dough development time, dough stability time, and loaf volume were noted to be increased first but decreased then. The grain yield and quality of Gaocheng 8901 were the highest when irrigated once after anthesis, while those of Jimai 20 were the best when irrigated twice after anthesis, respectively. The contents of monomeric protein, soluble glutenin, insoluble glutenin, total glutenin, flour protein, and wet gluten in the grains displayed the similar trends. Stepwise regression analysis showed that under the test post-anthesis irrigation frequencies, the key factor affecting dough stability time was insoluble glutenin content, and loaf volume was significantly correlated with total glutenin content. It was suggested that to maintain the quality stability of high grade strong gluten winter wheat, irrigation management should take the improvement of grain protein composition, and glutenin in particular, as the target.

  11. Psychobehavioural Factors Are More Strongly Associated with Successful Weight Management Than Predetermined Satiety Effect or Other Characteristics of Diet

    Directory of Open Access Journals (Sweden)

    Leila Karhunen

    2012-01-01

    Full Text Available This study aimed to investigate factors associated with weight management, especially whether satiety value of food as a part of a weight-maintenance diet would affect self-regulation of food intake and weight management. Altogether 82 obese subjects completed the study consisting of weight-loss and weight-maintenance (WM periods. During the WM, subjects were randomized into higher- and lower-satiety food groups. No differences were observed in the changes in body weight, energy intake, or eating behaviour between the groups, even despite the different macronutrient compositions of the diets. However, when regarding all study subjects, success in WM was most strongly associated with a greater increase in the flexible control of eating and experience of greater easiness of WM and control of food intake and a greater decrease in uncontrollable eating and psychological distress. Psychobehavioural factors seem to be more strongly associated with successful weight management than the predetermined satiety effect or other characteristics of the diet.

  12. A device to measure the effects of strong magnetic fields on the image resolution of PET scanners

    CERN Document Server

    Burdette, D; Chesi, E; Clinthorne, N H; Cochran, E; Honscheid, K; Huh, S S; Kagan, H; Knopp, M; Lacasta, C; Mikuz, M; Schmalbrock, P; Studen, A; Weilhammer, P

    2009-01-01

    Very high resolution images can be achieved in small animal PET systems utilizing solid state silicon pad detectors. As these systems approach sub-millimeter resolutions, the range of the positron is becoming the dominant contribution to image blur. The size of the positron range effect depends on the initial positron energy and hence the radioactive tracer used. For higher energy positron emitters, such as and , which are gaining importance in small animal studies, the width of the annihilation point distribution dominates the spatial resolution. This positron range effect can be reduced by embedding the field of view of the PET scanner in a strong magnetic field. In order to confirm this effect experimentally, we developed a high resolution PET instrument based on silicon pad detectors that can operate in a 7 T magnetic field. In this paper, we describe the instrument and present initial results of a study of the effects of magnetic fields up to 7 T on PET image resolution for and point sources.

  13. Colonization of a territory by a stochastic population under a strong Allee effect and a low immigration pressure.

    Science.gov (United States)

    Be'er, Shay; Assaf, Michael; Meerson, Baruch

    2015-06-01

    We study the dynamics of colonization of a territory by a stochastic population at low immigration pressure. We assume a sufficiently strong Allee effect that introduces, in deterministic theory, a large critical population size for colonization. At low immigration rates, the average precolonization population size is small, thus invalidating the WKB approximation to the master equation. We circumvent this difficulty by deriving an exact zero-flux solution of the master equation and matching it with an approximate nonzero-flux solution of the pertinent Fokker-Planck equation in a small region around the critical population size. This procedure provides an accurate evaluation of the quasistationary probability distribution of population sizes in the precolonization state and of the mean time to colonization, for a wide range of immigration rates. At sufficiently high immigration rates our results agree with WKB results obtained previously. At low immigration rates the results can be very different.

  14. Colonization of a territory by a stochastic population under a strong Allee effect and a low immigration pressure

    Science.gov (United States)

    Be'er, Shay; Assaf, Michael; Meerson, Baruch

    2015-06-01

    We study the dynamics of colonization of a territory by a stochastic population at low immigration pressure. We assume a sufficiently strong Allee effect that introduces, in deterministic theory, a large critical population size for colonization. At low immigration rates, the average precolonization population size is small, thus invalidating the WKB approximation to the master equation. We circumvent this difficulty by deriving an exact zero-flux solution of the master equation and matching it with an approximate nonzero-flux solution of the pertinent Fokker-Planck equation in a small region around the critical population size. This procedure provides an accurate evaluation of the quasistationary probability distribution of population sizes in the precolonization state and of the mean time to colonization, for a wide range of immigration rates. At sufficiently high immigration rates our results agree with WKB results obtained previously. At low immigration rates the results can be very different.

  15. Strong spin-filtering and spin-valve effects in a molecular V–C60–V contact

    Directory of Open Access Journals (Sweden)

    Mohammad Koleini

    2012-08-01

    Full Text Available Motivated by the recent achievements in the manipulation of C60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111 surface using first-principles calculations. For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%. Moreover, we find a significant change in the conductance between parallel and anti-parallel spin polarizations in the junction (86% which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems.

  16. Noise-induced extinction for a ratio-dependent predator-prey model with strong Allee effect in prey

    Science.gov (United States)

    Mandal, Partha Sarathi

    2018-04-01

    In this paper, we study a stochastically forced ratio-dependent predator-prey model with strong Allee effect in prey population. In the deterministic case, we show that the model exhibits the stable interior equilibrium point or limit cycle corresponding to the co-existence of both species. We investigate a probabilistic mechanism of the noise-induced extinction in a zone of stable interior equilibrium point. Computational methods based on the stochastic sensitivity function technique are applied for the analysis of the dispersion of random states near stable interior equilibrium point. This method allows to construct a confidence domain and estimate the threshold value of the noise intensity for a transition from the coexistence to the extinction.

  17. Field emission properties and strong localization effect in conduction mechanism of nanostructured perovskite LaNiO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Kamble, Ramesh B., E-mail: rbk.physics@coep.ac.in [Department of Physics, Indian Institute of Science, Bangalore 560012, Karnataka (India); Department of Physics, College of Engineering, Pune 411005, Maharashtra (India); Tanty, Narendra; Patra, Ananya; Prasad, V. [Department of Physics, Indian Institute of Science, Bangalore 560012, Karnataka (India)

    2016-08-22

    We report the potential field emission of highly conducting metallic perovskite lanthanum nickelate (LaNiO{sub 3}) from the nanostructured pyramidal and whisker shaped tips as electron emitters. Nano particles of lanthanum nickelate (LNO) were prepared by sol-gel route. Structural and morphological studies have been carried out. Field emission of LNO exhibited high emission current density, J = 3.37 mA/cm{sup 2} at a low threshold electric field, E{sub th} = 16.91 V/μm, obeying Fowler–Nordheim tunneling. The DC electrical resistivity exhibited upturn at 11.6 K indicating localization of electron at low temperature. Magnetoresistance measurement at different temperatures confirmed strong localization in nanostructured LNO obeying Anderson localization effect at low temperature.

  18. Strong Photonic-Band-Gap Effect on the Spontaneous Emission in 3D Lead Halide Perovskite Photonic Crystals.

    Science.gov (United States)

    Zhou, Xue; Li, Mingzhu; Wang, Kang; Li, Huizeng; Li, Yanan; Li, Chang; Yan, Yongli; Zhao, Yongsheng; Song, Yanlin

    2018-03-25

    Stimulated emission in perovskite-embedded polymer opal structures is investigated. A polymer opal structure is filled with a perovskite, and perovskite photonic crystals are prepared. The spontaneous emission of the perovskite embedded in the polymer opal structures exhibits clear signatures of amplified spontaneous emission (ASE) via gain modulation. The difference in refractive-index contrast between the perovskite and the polymer opal is large enough for retaining photonic-crystals properties. The photonic band gap has a strong effect on the fluorescence emission intensity and lifetime. The stimulated emission spectrum exhibits a narrow ASE rather than a wide fluorescence peak in the thin film. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Psychobehavioural Factors Are More Strongly Associated with Successful Weight Management Than Predetermined Satiety Effect or Other Characteristics of Diet

    DEFF Research Database (Denmark)

    Karhunen, Leila; Lyly, Marika; Lapveteläinen, Anja

    2012-01-01

    This study aimed to investigate factors associated with weight management, especially whether satiety value of food as a part of a weight-maintenance diet would affect self-regulation of food intake and weight management. Altogether 82 obese subjects completed the study consisting of weight...... factors seem to be more strongly associated with successful weight management than the predetermined satiety effect or other characteristics of the diet.......-loss and weight-maintenance (WM) periods. During theWM, subjects were randomized into higher- and lower-satiety food groups. No differences were observed in the changes in body weight, energy intake, or eating behaviour between the groups, even despite the different macronutrient compositions of the diets...

  20. Strong spin-filtering and spin-valve effects in a molecular V-C-60-V contact

    DEFF Research Database (Denmark)

    Koleini, Mohammad; Brandbyge, Mads

    2012-01-01

    Motivated by the recent achievements in the manipulation of C-60 molecules in STM experiments, we study theoretically the structure and electronic properties of a C-60 molecule in an STM tunneljunction with a magnetic tip and magnetic adatom on a Cu(111) surface using first-principles calculations....... For the case of a vanadium tip/adatom, we demonstrate how spin coupling between the magnetic V atoms, mediated by the C-60, can be observed in the electronic transport, which display a strong spin-filtering effect, allowing mainly majority-spin electrons to pass (>95%). Moreover, we find a significant change...... in the conductance between parallel and anti-parallel spin polarizations in the junction (86%) which suggests that STM experiments should be able to characterize the magnetism and spin coupling for these systems....

  1. Compressibility effects on a shear flow in strongly coupled dusty plasma. I. A study using computational fluid dynamics

    Science.gov (United States)

    Gupta, Akanksha; Ganesh, Rajaraman

    2018-01-01

    We study compressibility effects on the two-dimensional strongly coupled dusty plasma by means of computational fluid dynamics (CFD) with the Kolmogorov flow as an initial shear flow profile. Nonlinear compressible vortex flow dynamics and other linear and nonlinear properties of such flow in the presence of variable density, pressure, and electrostatic potential are addressed using a generalised compressible hydrodynamic model. The stabilizing effect of compressibility on the unstable shear flows in the presence of strong correlation ( τm>0 ) is presented. Increasing the Mach number relatively reduces the growth-rate of perturbation. On the other hand, strong correlation makes the medium to be more unstable and increases the growth rate. Using an eigen value solver, various linear properties of compressible Kolmogorov flow have been investigated for a range of variable parameters, for example, Mach number, Reynolds number, and viscoelastic coefficient (τm). Compressible Kolmogorov flow becomes unstable above a critical value of the Reynolds number (Rc), and below Rc, the shear flow is found to be neutrally stable. In this study, it is found that the viscoelasticity reduces the value of Rc. For our choice of parameters, at τm=τmc , the compressible Kolmogorov flow becomes unconditionally unstable and no Rc exists for values of τm higher than τmc . To address the nonlinear properties, for example, mode-mode interaction due to the presence of nonlinearity in the fluid, vortex formation, etc., a massively parallelized Advanced Generalized SPECTral Code (AG-Spect) has been developed. AG-Spect, a newly developed code, is an efficient tool to solve any set of nonlinear fluid dynamic equations. A good agreement in linear growth rates obtained from the eigen value solver and time dependent simulation (AG-Spect) is found. In our CFD study, the suppression of instability, elongated vortex structures, pattern formation, nonlinear saturation, and visco

  2. Brief life history and views of Ted Rogers, founder of social work ...

    African Journals Online (AJOL)

    This brief communication shares notes from a 2012 meeting of Zimbabwean social workers in the United Kingdom with Ted Rogers, founder of social work education in Zimbabwe. It gives a brief of his work whilst he was still in Zimbabwe and shares his thinking about the current state of affairs in social work education in ...

  3. Clovis Vincent (1879-1947): founder of French neurosurgery and promoter of oncologic neurosurgery.

    Science.gov (United States)

    Karamanou, M; Androutsos, G; Lymperi, M; Stamboulis, E; Liappas, I; Lykouras, E

    2012-01-01

    The eminent neurologist Clovis Vincent decided to become neurosurgeon at an advanced age. His is considered the founder of French neurosurgery and the Europe's first neurosurgeon. He was mainly interested in pituitary tumors and his work on oncologic neurosurgery remains valuable.

  4. Designing for a Living? Income Determinants Among Firm Founders in the Dutch Design Sector

    NARCIS (Netherlands)

    Vankan, A.; Frenken, K.; Castaldi, C.

    2014-01-01

    Many studies have analysed the role of the creative class in fostering regional development. The focus on regional development neglects the individual differences in success among members in the creative class and among firms within creative industries. We study firm founders in three design sectors

  5. Genome-wide patterns of identity-by-descent sharing in the French Canadian founder population.

    Science.gov (United States)

    Gauvin, Héloïse; Moreau, Claudia; Lefebvre, Jean-François; Laprise, Catherine; Vézina, Hélène; Labuda, Damian; Roy-Gagnon, Marie-Hélène

    2014-06-01

    In genetics the ability to accurately describe the familial relationships among a group of individuals can be very useful. Recent statistical tools succeeded in assessing the degree of relatedness up to 6-7 generations with good power using dense genome-wide single-nucleotide polymorphism data to estimate the extent of identity-by-descent (IBD) sharing. It is therefore important to describe genome-wide patterns of IBD sharing for more remote and complex relatedness between individuals, such as that observed in a founder population like Quebec, Canada. Taking advantage of the extended genealogical records of the French Canadian founder population, we first compared different tools to identify regions of IBD in order to best describe genome-wide IBD sharing and its correlation with genealogical characteristics. Results showed that the extent of IBD sharing identified with FastIBD correlates best with relatedness measured using genealogical data. Total length of IBD sharing explained 85% of the genealogical kinship's variance. In addition, we observed significantly higher sharing in pairs of individuals with at least one inbred ancestor compared with those without any. Furthermore, patterns of IBD sharing and average sharing were different across regional populations, consistent with the settlement history of Quebec. Our results suggest that, as expected, the complex relatedness present in founder populations is reflected in patterns of IBD sharing. Using these patterns, it is thus possible to gain insight on the types of distant relationships in a sample from a founder population like Quebec.

  6. Origin and migration of an Afrikaner founder mutation FHAfrikaner-2 (V408M) causing familial hypercholesterolemia

    NARCIS (Netherlands)

    Defesche, J. C.; van Diermen, D. E.; Hayden, M. R.; Kastelein, J. P.

    1996-01-01

    Of the three major Afrikaner founder mutations, responsible for more than 95% of Familial Hypercholesterolemia cases among South African Afrikaners, one mutation called V408M or FHAfrikaner-2 was identified in the Netherlands. Subsequent analysis of a group of Canadian patients of Dutch origin with

  7. The Timeless Legacy of Robert Koch-Founder of Medical Microbiology

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 11; Issue 9. The Timeless Legacy of Robert Koch - Founder of Medical Microbiology. Jaya S Tyagi. General Article Volume 11 Issue 9 September 2006 pp 20-28. Fulltext. Click here to view fulltext PDF. Permanent link:

  8. Drug susceptibility testing in microaerophilic parasites: Cysteine strongly affects the effectivities of metronidazole and auranofin, a novel and promising antimicrobial

    Directory of Open Access Journals (Sweden)

    David Leitsch

    2017-12-01

    Full Text Available The microaerophilic parasites Entamoeba histolytica, Trichomonas vaginalis, and Giardia lamblia annually cause hundreds of millions of human infections which are treated with antiparasitic drugs. Metronidazole is the most often prescribed drug but also other drugs are in use, and novel drugs with improved characteristics are constantly being developed. One of these novel drugs is auranofin, originally an antirheumatic which has been relabelled for the treatment of parasitic infections. Drug effectivity is arguably the most important criterion for its applicability and is commonly assessed in susceptibility assays using in vitro cultures of a given pathogen. However, drug susceptibility assays can be strongly affected by certain compounds in the growth media. In the case of microaerophilic parasites, cysteine which is added in large amounts as an antioxidant is an obvious candidate because it is highly reactive and known to modulate the toxicity of metronidazole in several microaerophilic parasites.In this study, it was attempted to reduce cysteine concentrations as far as possible without affecting parasite viability by performing drug susceptibility assays under strictly anaerobic conditions in an anaerobic cabinet. Indeed, T. vaginalis and E. histolytica could be grown without any cysteine added and the cysteine concentration necessary to maintain G. lamblia could be reduced to 20%. Susceptibilities to metronidazole were found to be clearly reduced in the presence of cysteine. With auranofin the protective effect of cysteine was extreme, providing protection to concentrations up to 100-fold higher as observed in the absence of cysteine. With three other drugs tested, albendazole, furazolidone and nitazoxanide, all in use against G. lamblia, the effect of cysteine was less pronounced. Oxygen was found to have a less marked impact on metronidazole and auranofin than cysteine but bovine bile which is standardly used in growth media for G

  9. Strong Quantum Confinement Effects and Chiral Excitons in Bio-Inspired ZnO–Amino Acid Cocrystals

    KAUST Repository

    Muhammed, Madathumpady Abubaker Habeeb

    2018-02-20

    Elucidating the underlying principles behind band gap engineering is paramount for the successful implementation of semiconductors in photonic and optoelectronic devices. Recently it has been shown that the band gap of a wide and direct band gap semiconductor, such as ZnO, can be modified upon cocrystallization with amino acids, with the role of the biomolecules remaining unclear. Here, by probing and modeling the light-emitting properties of ZnO-amino acid cocrystals, we identify the amino acids\\' role on this band gap modulation and demonstrate their effective chirality transfer to the interband excitations in ZnO. Our 3D quantum model suggests that the strong band edge emission blue-shift in the cocrystals can be explained by a quasi-periodic distribution of amino acid potential barriers within the ZnO crystal lattice. Overall, our findings indicate that biomolecule cocrystallization can be used as a truly bio-inspired means to induce chiral quantum confinement effects in quasi-bulk semiconductors.

  10. Naegleria fowleri lysate induces strong cytopathic effects and pro-inflammatory cytokine release in rat microglial cells.

    Science.gov (United States)

    Lee, Yang-Jin; Park, Chang-Eun; Kim, Jong-Hyun; Sohn, Hae-Jin; Lee, Jinyoung; Jung, Suk-Yul; Shin, Ho-Joon

    2011-09-01

    Naegleria fowleri, a ubiquitous free-living ameba, causes fatal primary amebic meningoencephalitis in humans. N. fowleri trophozoites are known to induce cytopathic changes upon contact with microglial cells, including necrotic and apoptotic cell death and pro-inflammatory cytokine release. In this study, we treated rat microglial cells with amebic lysate to probe contact-independent mechanisms for cytotoxicity, determining through a combination of light microscopy and scanning and transmission electron microscopy whether N. fowleri lysate could effect on both necrosis and apoptosis on microglia in a time- as well as dose-dependent fashion. A (51)Cr release assay demonstrated pronounced lysate induction of cytotoxicity (71.5%) toward microglial cells by 24 hr after its addition to cultures. In an assay of pro-inflammatory cytokine release, microglial cells treated with N. fowleri lysate produced TNF-α, IL-6, and IL-1β, though generation of the former 2 cytokines was reduced with time, and that of the last increased throughout the experimental period. In summary, N. fowleri lysate exerted strong cytopathic effects on microglial cells, and elicited pro-inflammatory cytokine release as a primary immune response.

  11. Synergistic effect between strongly coupled CoAl layered double hydroxides and graphene for the electrocatalytic reduction of oxygen

    International Nuclear Information System (INIS)

    Wang, Yinling; Wang, Zhangcui; Wu, Xiaoqin; Liu, Xiaowang; Li, Maoguo

    2016-01-01

    Highlights: • CoAl-LDHs were synthesized on the surface of graphene oxide in situ. • The oxygen reduction reaction activity of the catalyst was investigated. • The synergistic effect between CoAl-LDHs and rGO is discussed in detail. • The roles of Co 2+ in the LDHs were clarified. - Abstract: Precious metal-free electrocatalysts with high efficiency and durability for the oxygen reduction reaction (ORR) are strongly desired in the field of energy technology. Herein, the CoAl layered double hydroxides (CoAl-LDHs)/reduced graphene oxide (rGO) composites were successfully prepared by growing CoAl-LDHs on the surface of GO in situ via coprecipitation and subsequently hydrothermal treatment. The structure, composition, morphology and ORR catalytic activity of the CoAl-LDHs/rGO composites were investigated as a function of mass ratios of CoAl-LDHs and GO. The results show that there is an optimum mass ratio of CoAl-LDHs and GO (w CoAl-LDHs :w GO = 1:5) for the ORR catalytic activity, where the electron transfer number for ORR at the CoAl-LDHs/rGO composites reaches to 3.5, closing to the full four-electron process. The synergistic effect between CoAl-LDHs and rGO is discussed in detail and the discussion is instructive for the construction of the better transition metal oxides/carbon composite-based ORR catalysts.

  12. Effects of strong interactions between Ti and ceria on the structures of Ti/CeO2.

    Science.gov (United States)

    Yao, Xiao-Dan; Zhu, Kong-Jie; Teng, Bo-Tao; Yu, Cao-Ming; Zhang, Yun-Lei; Liu, Ya; Fan, Maohong; Wen, Xiao-Dong

    2016-11-30

    The effects of strong interactions between Ti and ceria on the structures of Ti/CeO 2 (111) are systematically investigated by density functional theory calculation. To our best knowledge, the adsorption energy of a Ti atom at the hollow site of CeO 2 is the highest value (-7.99 eV) reported in the literature compared with those of Au (-0.88--1.26 eV), Ag (-1.42 eV), Cu (-2.69 eV), Pd (-1.75 eV), Pt (-2.62 eV) and Sn (-3.68 eV). It is very interesting to find that Ti adatoms disperse at the hollow site of CeO 2 (111) to form surface TiO x species, instead of aggregating to form Ti metal clusters for the Ti-CeO 2 interactions that are much stronger than those of Ti-Ti ones. Ti adatoms are completely oxidized to Ti 4+ ions if they are monatomically dispersed on the next near hollow sites of CeO 2 (111) (xTi-NN-hollow); while Ti 3+ ions are observed when they locate at the near hollow sites (xTi-N-hollow). Due to the electronic repulsive effects among Ti 3+ ions, the adsorption energies of xTi-N-hollow are slightly weaker than those of xTi-NN-hollow. Simultaneously, the existence of unstable Ti 3+ ions on xTi-N-hollow also leads to the restructuring of xTi-N-hollow by surface O atoms of ceria transferring to the top of Ti 3+ ions, or oxidation by O 2 adsorption and dissociation. Both processes improve the stability of the xTi/CeO 2 system by Ti 3+ oxidation. Correspondingly, surface TiO 2 -like species form. This work sheds light into the structures of metal/CeO 2 catalysts with strong interactions between the metal and the ceria support.

  13. Fitness Effects of Chlorpyrifos in the Damselfly Enallagma cyathigerum Strongly Depend upon Temperature and Food Level and Can Bridge Metamorphosis.

    Directory of Open Access Journals (Sweden)

    Lizanne Janssens

    Full Text Available Interactions between pollutants and suboptimal environmental conditions can have severe consequences for the toxicity of pollutants, yet are still poorly understood. To identify patterns across environmental conditions and across fitness-related variables we exposed Enallagma cyathigerum damselfly larvae to the pesticide chlorpyrifos at two food levels or at two temperatures and quantified four fitness-related variables (larval survival, development time, mass at emergence and adult cold resistance. Food level and temperature did not affect survival in the absence of the pesticide, yet the pesticide reduced survival only at the high temperature. Animals reacted to the pesticide by accelerating their development but only at the high food level and at the low temperature; at the low food level, however, pesticide exposure resulted in a slower development. Chlorpyrifos exposure resulted in smaller adults except in animals reared at the high food level. Animals reared at the low food level and at the low temperature had a higher cold resistance which was not affected by the pesticide. In summary our study highlight that combined effects of exposure to chlorpyrifos and the two environmental conditions (i were mostly interactive and sometimes even reversed in comparison with the effect of the environmental condition in isolation, (ii strongly differed depending on the fitness-related variable under study, (iii were not always predictable based on the effect of the environmental condition in isolation, and (iv bridged metamorphosis depending on which environmental condition was combined with the pesticide thereby potentially carrying over from aquatic to terrestrial ecosystems. These findings are relevant when extrapolating results of laboratory tests done under ideal environmental conditions to natural communities.

  14. Founder and Recurrent Mutations in BRCA1 and BRCA2 Genes in Latin American Countries: State of the Art and Literature Review.

    Science.gov (United States)

    Ossa, Carlos Andrés; Torres, Diana

    2016-07-01

    Numerous epidemiological factors affect the probability of developing breast or ovarian cancer, but no predictor is as determinant as inheriting a mutation in BRCA1 or BRCA2. The concept of the founder effect explains the reduced genetic variability in some populations, according to the theory that new populations can be formed from a reduced number of individuals, so the new population would carry only a small fraction of the genetic variability of the original population. The main purpose of this review is to provide an update on the state of the art in founder mutations and some recurrent mutations that have recently been described in Latin America. A literature search was performed in the electronic databases of PUBMED, EMBASE, LILACS, and BIREME using the terms BRCA1, BRCA2, founder mutation, Latin American population, and Hispanic. Sixty-two papers were identified, of which 38 were considered relevant for this review. Each result is shown per country. In Latin America, clear founder effects have been reported in Mexico (BRCA1 del exons 9-12), Brazil (BRCA1 5382insC and BRCA2 c.156_157insAlu), and Colombia (BRCA1 3450del4, A1708E, and BRCA2 3034del4) and in Latinas residing in Southern California (BRCA1 185delAG, IVS5+1G>A, S955x, and R1443x). Of these, mutation BRCA1 3450del4 has also been reported in Brazil and Chile, whereas mutation BRCA2 3034del4 has been reported in Argentina and Peru. These data support the idea that although most Hispanic populations are the result of a mixture between Europeans, Africans, and Amerindians, the relative proportion of each genetic component varies throughout the Hispanic populations, making it necessary to identify the mutations characteristic of each population to generate mutation profiles adjusted to each one of them. In Latin American countries, and even among regions of the same country, there is great heterogeneity of ancestors. Therefore, Latinas should not be analyzed like other population groups without taking

  15. Genotype and Phenotype Studies in Autosomal Dominant Retinitis Pigmentosa (adRP) of the French Canadian Founder Population.

    Science.gov (United States)

    Coussa, Razek Georges; Chakarova, Christina; Ajlan, Radwan; Taha, Mohammed; Kavalec, Conrad; Gomolin, Julius; Khan, Ayesha; Lopez, Irma; Ren, Huanan; Waseem, Naushin; Kamenarova, Kunka; Bhattacharya, Shomi S; Koenekoop, Robert K

    2015-12-01

    The French Canadian population of Quebec is a unique, well-known founder population with religious, linguistic, and geographic isolation. The genetics of retinitis pigmentosa (RP) in Quebec is not well studied thus far. The purpose of our study was to establish the genetic architecture of autosomal dominant RP (adRP) and to characterize the phenotypes associated with new adRP mutations in Quebec. Sanger sequencing of the commonly mutated currently known adRP genes was performed in a clinically well-characterized cohort of 60 adRP French Canadian families. Phenotypes were analyzed by projected visual acuity (best corrected), Goldmann visual fields, optical coherence tomography (OCT), fundus autofluorescence (FAF), and ERG. The potential effect of the novel mutations was assessed using in silico bioinformatic tools. The pathogenicity of all variants was then confirmed by segregation analysis within the families, when available. We identified the causal mutation/gene in 24 of our adRP families, as 24 (40%) of 60 patients had adRP mutations in six known adRP genes. Eleven (46%) of these mutations were in RHO, four mutations (17%) were found in SNRNP200, three mutations (12.5%) in PRPH2/RDS, three mutations (12.5%) in TOPORS, two mutations (8%) in PRPF31, and one mutation (4%) in IMPDH1. Four mutations were novel. We identified new mutations in RHO (p.S270I), PRPF31 (p.R288W), IMPDH1 (p.Q318H), and TOPORS (p.H889R); the rest were previously reported. We present the genotype-phenotype characteristics of the four novel missense mutations. This is the first large screening of adRP genes in the founder population of Quebec. Our prevalence of known adRP genes is 40% in the French Canadian population, which is lower than in other adRP populations around the world, illustrating the uniqueness of the French Canadian population. Our findings are crucial in expanding the current understanding of the genotypic-phenotypic spectrum of RP and documenting the genetic architecture of

  16. Effects of Joint Interpretation of the Strong Interest Inventory and the Myers-Briggs Type Indicator in Career Choice.

    Science.gov (United States)

    Katz, Louise; Joyner, John W.; Seaman, Nancy

    1999-01-01

    Students completed either the Strong Interest Inventory (n=114) or Myers-Briggs Type Indicator (n=108), both (n=99), or none (n=106). Twelve weeks after interpretation, those who completed both showed more change, specificity, or certainty in their career goal. The Myers-Briggs proved as helpful as Strong in career decision making. (SK)

  17. A PHYSICAL MODEL OF THE EFFECT OF A SHALLOW WEAK LAYER ON STRONG GROUND MOTION FOR STRIKE-SLIP RUPTURES

    Energy Technology Data Exchange (ETDEWEB)

    JAMES N. BRUNE AND ABDOLRASOOL ANOOSHEHPOOR

    1998-02-23

    We report results of foam-rubber modeling of the effect of a shallow weak layer on ground motion from strike-slip ruptures. Computer modeling of strong ground motion from strike-slip earthquakes has involved somewhat arbitrary assumptions about the nature of slip along the shallow part of the fault (e.g., fixing the slip to be zero along the upper 2 kilometers of the fault plane) in order to match certain strong motion accelerograms. Most modeling studies of earthquake strong ground motion have used what is termed kinematic dislocation modeling. In kinematic modeling the time function for slip on the fault is prescribed, and the response of the layered medium is calculated. Unfortunately, there is no guarantee that the model and the prescribed slip are physically reasonable unless the true nature of the medium and its motions are known ahead of time. There is good reason to believe that in many cases faults are weak along the upper few kilometers of the fault zone and may not be able to maintain high levels of shear strain required for high dynamic energy release during earthquakes. Physical models of faulting, as distinct from numerical or mathematical models, are guaranteed to obey static and dynamic mechanical laws. Foam-rubber modeling studies have been reported in a number of publications. The object of this paper is to present results of physical modeling using a shallow weak layer, in order to verify the physical basis for assuming a long rise time and a reduced high frequency pulse for the slip on the shallow part of faults. It appears a 2-kilometer deep, weak zone along strike-slip faults could indeed reduce the high frequency energy radiated from shallow slip, and that this effect can best be represented by superimposing a small amplitude, short rise-time pulse at the onset of a much longer rise-time slip. A weak zone was modeled by inserting weak plastic layers of a few inches in thickness into the foam rubber model. For the 15 cm weak zone the average

  18. Characterization of weak, fair and strong neutron absorbing materials by means of neutron transmission: Beam hardening effect

    International Nuclear Information System (INIS)

    Kharfi, F.; Bastuerk, M.; Boucenna, A.

    2006-01-01

    The characterization of neutron absorbing materials as well as quantification of neutron attenuation through matter is very essential in various fields, namely in shielding calculation. The objective of this work is to describe an experimental procedure to be used for the determination of neutron transmission through different materials. The proposed method is based on the relation between the gray value measured on neutron radiography image and the corresponding inducing neutron beam. For such a purpose, three kinds of materials (in shape of plate) were investigated using thermal neutrons: (1) boron-alloyed stainless steel as strong absorber; (2) copper and steel as fair absorbers and (3) aluminum as weak absorber. This work is not limited to the determination of neutron transmission through matters; it is also spread out to the measure of the surface density of the neutron absorbing elements (ρ s ) as a function of thickness of neutron absorbing material such as boron-alloyed stainless steel. The beam hardening effect depending on material thickness was also studied using the neutron transmission measurements. A theoretical approach was used to interpret the experimental results. The neutron transmission measurements were performed at the Neutron Radiography and Tomography facility of the Atomic Institute of the Austrian Universities in Vienna. Finally, a Maxwellian neutron distribution of incident neutron beam was used in the theoretical calculations of neutron energy shift in order to compare with experiments results. The obtained experimental results are in a good agreement with the developed theoretical approach

  19. Characterization of weak, fair and strong neutron absorbing materials by means of neutron transmission: Beam hardening effect

    Science.gov (United States)

    Kharfi, F.; Bastuerk, M.; Boucenna, A.

    2006-09-01

    The characterization of neutron absorbing materials as well as quantification of neutron attenuation through matter is very essential in various fields, namely in shielding calculation. The objective of this work is to describe an experimental procedure to be used for the determination of neutron transmission through different materials. The proposed method is based on the relation between the gray value measured on neutron radiography image and the corresponding inducing neutron beam. For such a purpose, three kinds of materials (in shape of plate) were investigated using thermal neutrons: (1) boron-alloyed stainless steel as strong absorber; (2) copper and steel as fair absorbers and (3) aluminum as weak absorber. This work is not limited to the determination of neutron transmission through matters; it is also spread out to the measure of the surface density of the neutron absorbing elements (ρs) as a function of thickness of neutron absorbing material such as boron-alloyed stainless steel. The beam hardening effect depending on material thickness was also studied using the neutron transmission measurements. A theoretical approach was used to interpret the experimental results. The neutron transmission measurements were performed at the Neutron Radiography and Tomography facility of the Atomic Institute of the Austrian Universities in Vienna. Finally, a Maxwellian neutron distribution of incident neutron beam was used in the theoretical calculations of neutron energy shift in order to compare with experiments results. The obtained experimental results are in a good agreement with the developed theoretical approach.

  20. Counting the founders: the matrilineal genetic ancestry of the Jewish Diaspora.

    Science.gov (United States)

    Behar, Doron M; Metspalu, Ene; Kivisild, Toomas; Rosset, Saharon; Tzur, Shay; Hadid, Yarin; Yudkovsky, Guennady; Rosengarten, Dror; Pereira, Luisa; Amorim, Antonio; Kutuev, Ildus; Gurwitz, David; Bonne-Tamir, Batsheva; Villems, Richard; Skorecki, Karl

    2008-04-30

    The history of the Jewish Diaspora dates back to the Assyrian and Babylonian conquests in the Levant, followed by complex demographic and migratory trajectories over the ensuing millennia which pose a serious challenge to unraveling population genetic patterns. Here we ask whether phylogenetic analysis, based on highly resolved mitochondrial DNA (mtDNA) phylogenies can discern among maternal ancestries of the Diaspora. Accordingly, 1,142 samples from 14 different non-Ashkenazi Jewish communities were analyzed. A list of complete mtDNA sequences was established for all variants present at high frequency in the communities studied, along with high-resolution genotyping of all samples. Unlike the previously reported pattern observed among Ashkenazi Jews, the numerically major portion of the non-Ashkenazi Jews, currently estimated at 5 million people and comprised of the Moroccan, Iraqi, Iranian and Iberian Exile Jewish communities showed no evidence for a narrow founder effect, which did however characterize the smaller and more remote Belmonte, Indian and the two Caucasus communities. The Indian and Ethiopian Jewish sample sets suggested local female introgression, while mtDNAs in all other communities studied belong to a well-characterized West Eurasian pool of maternal lineages. Absence of sub-Saharan African mtDNA lineages among the North African Jewish communities suggests negligible or low level of admixture with females of the host populations among whom the African haplogroup (Hg) L0-L3 sub-clades variants are common. In contrast, the North African and Iberian Exile Jewish communities show influence of putative Iberian admixture as documented by mtDNA Hg HV0 variants. These findings highlight striking differences in the demographic history of the widespread Jewish Diaspora.

  1. A strong genetic footprint of the re-introduction history of Alpine ibex (Capra ibex ibex).

    Science.gov (United States)

    Biebach, Iris; Keller, Lukas F

    2009-12-01

    A population's neutral genetic variation is a composite of its size, degree of isolation and demographic history. Bottlenecks and founder events increase genetic drift, leading to the loss of genetic variation and increased genetic differentiation among populations. Gene flow has the opposite effects. Thus, gene flow can override the genetic patterns caused by founder events. Using 37 microsatellite loci, we investigated the effects of serial bottlenecks on genetic variation and differentiation among 42 Alpine ibex populations in Switzerland with known re-introduction histories. We detected a strong footprint of re-introduction events on contemporary genetic structure, with re-introduction history explaining a substantial part of the genetic differentiation among populations. As a result of the translocation of a considerable number of individuals from the sole formerly surviving population in northern Italy, most of the genetic variation of the ancestral population is now present in the combined re-introduced Swiss populations. However, re-introductions split up the genetic variation among populations, such that each contemporary Swiss population showed lower genetic variation than the ancestral population. As expected, serial bottlenecks had different effects on the expected heterozygosity (He) and standardized number of alleles (sNa). While loss of sNa was higher in the first bottlenecks than in subsequent ones, He declined to a similar degree with each bottleneck. Thus, genetic drift was detected with each bottleneck, even when no loss of sNa was observed. Overall, more than a hundred years after the beginning of this successful re-introduction programme, re-introduction history was the main determinant of today's genetic structure.

  2. Molecular evidence for recent founder populations and human-mediated migration in the barley scald pathogen Rhynchosporium secalis.

    Science.gov (United States)

    Linde, C C; Zala, M; McDonald, B A

    2009-06-01

    Rhynchosporium secalis is an important pathogen of barley globally. Fourteen polymorphic microsatellites were analyzed for 1664 R. secalis isolates sampled from 37 field populations to infer their demographic history. The results falsified the hypothesis that R. secalis co-evolved with its barley host in the Middle East. Populations from Scandinavia had significantly higher allelic diversities, the greatest number of private alleles and the highest genotypic diversities. All but three of the analyzed populations had an excess of gene diversity compared to the number of alleles, consistent with a recent population bottleneck. The remaining populations had a gene diversity deficit consistent with a population expansion following a recent population bottleneck in the last +/-100 years. A coalescent analysis revealed that the effective population sizes based on theta, of the analyzed populations were small relative to their ancestral population sizes, indicating that only a fraction of the diversity present in the ancestral populations was transmitted into current populations. These findings are consistent with the hypothesis that the pathogen population on barley experienced a selection bottleneck imposed by the host and/or are founder populations. The mean estimate of migration rates was 2.2 (avg 90% confidence interval=1.3-3.1). Major migration routes were identified among populations separated by long distances, eg between South Africa and Australia, as well as among North Africa, the Middle East and California, suggesting contemporary exchange of infected barley seed. In contrast with earlier findings, most populations exhibited significant gametic disequilibrium, probably as a result of genetic drift. We conclude that the majority of R. secalis populations have experienced human-mediated migration that led to numerous and relatively recent founder events around the world.

  3. Inbred Strain Variant Database (ISVdb: A Repository for Probabilistically Informed Sequence Differences Among the Collaborative Cross Strains and Their Founders

    Directory of Open Access Journals (Sweden)

    Daniel Oreper

    2017-06-01

    Full Text Available The Collaborative Cross (CC is a panel of recently established multiparental recombinant inbred mouse strains. For the CC, as for any multiparental population (MPP, effective experimental design and analysis benefit from detailed knowledge of the genetic differences between strains. Such differences can be directly determined by sequencing, but until now whole-genome sequencing was not publicly available for individual CC strains. An alternative and complementary approach is to infer genetic differences by combining two pieces of information: probabilistic estimates of the CC haplotype mosaic from a custom genotyping array, and probabilistic variant calls from sequencing of the CC founders. The computation for this inference, especially when performed genome-wide, can be intricate and time-consuming, requiring the researcher to generate nontrivial and potentially error-prone scripts. To provide standardized, easy-to-access CC sequence information, we have developed the Inbred Strain Variant Database (ISVdb. The ISVdb provides, for all the exonic variants from the Sanger Institute mouse sequencing dataset, direct sequence information for CC founders and, critically, the imputed sequence information for CC strains. Notably, the ISVdb also: (1 provides predicted variant consequence metadata; (2 allows rapid simulation of F1 populations; and (3 preserves imputation uncertainty, which will allow imputed data to be refined in the future as additional sequencing and genotyping data are collected. The ISVdb information is housed in an SQL database and is easily accessible through a custom online interface (http://isvdb.unc.edu, reducing the analytic burden on any researcher using the CC.

  4. The dual effect of vegetation green-up date and strong wind on the return period of spring dust storms.

    Science.gov (United States)

    Feng, Jieling; Li, Ning; Zhang, Zhengtao; Chen, Xi

    2017-08-15

    Vegetation phenology changes have been widely applied in the disaster risk assessments of the spring dust storms, and vegetation green-up date shifts have a strong influence on dust storms. However, the effect of earlier vegetation green-up dates due to climate warming on the evaluation of dust storms return periods remains an important, but poorly understood issue. In this study, we evaluate the spring dust storm return period (February to June) in Inner Mongolia, Northern China, using 165 observations of severe spring dust storm events from 16 weather stations, and regional vegetation green-up dates as an integrated factor from NDVI (Normalized Difference Vegetation Index), covering a period from 1982 to 2007, by building the bivariate Copula model. We found that the joint return period showed better fitting results than without considering the integrated factor when the actual dust storm return period is longer than 2years. Also, for extremely severe dust storm events, the gap between simulation result and actual return period can be narrowed up to 0.4888years by using integrated factor. Furthermore, the risk map based on the return period results shows that the Mandula, Zhurihe, Sunitezuoqi, Narenbaolige stations are identified as high risk areas. In this study area, land surface is extensively covered by grasses and shrubs, vegetation green-up date can play a significant role in restraining spring dust storm outbreaks. Therefore, we suggest that Copula method can become a useful tool for joint return period evaluation and risk analysis of severe dust storms. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Strong enhancement of Penning ionization for asymmetric atom pairs in cold Rydberg gases: the Tom and Jerry effect

    KAUST Repository

    Efimov, D K

    2016-05-18

    We consider Penning ionization of Rydberg atom pairs as an Auger-type process induced by the dipole-dipole interaction and employ semiclassical formulae for dipole transitions to calculate the autoionization width as a function of the principal quantum numbers, n d, n i, of both atoms. While for symmetric atom pairs with the well-known increase of the autoionization width with increasing n 0 is obtained, the result for asymmetric pairs is counterintuitive - for a fixed n i of the ionizing atom of the pair, the autoionization width strongly increases with decreasing n d of the de-excited atom. For H Rydberg atoms this increase reaches two orders of magnitude at the maximum of the n d dependence, and the same type of counterintuitive behavior is exhibited also by Na, Rb and Cs atoms. This is a purely quantum-mechanical effect, which points towards existence of optimal (we call them \\'Tom\\' and \\'Jerry\\' for \\'big\\' and \\'small\\') pairs of Rydberg atoms with respect to autoionization efficiency. Building on the model of population redistribution in cold Rydberg gases proposed in [1], we demonstrate that population evolution following the initial laser excitation of Rydberg atoms in state n 0 would eventually lead to the formation of such Tom-Jerry pairs with which feature autoionization widths that are enhanced by several orders of magnitude compared to that of two atoms in the initial laser-excited state n 0. We also show that in the high-density regime of cold Rydberg gas experiments the ionization rate of Tom-Jerry pairs can be substantially larger than the blackbody radiation-induced photoionization rate. © 2016 IOP Publishing Ltd.

  6. Experimental investigation of effect of surface gravity waves and spray on heat and momentum flux at strong wind conditions

    Science.gov (United States)

    Troitskaya, Yuliya; Sergeev, Daniil; Vdovin, Maxim; Kandaurov, Alexander; Ermakova, Olga; Kazakov, Vassily

    2015-04-01

    The most important characteristics that determine the interaction between atmosphere and ocean are fluxes of momentum, heat and moisture. For their parameterization the dimensionless exchange coefficients (the surface drag coefficient CD and the heat transfer coefficient or the Stanton number CT) are used. Numerous field and laboratory experiments show that CD increases with increasing wind speed at moderate and strong wind, and as it was shows recently CD decreases at hurricane wind speed. Waves are known to increase the sea surface resistance due to enhanced form drag, the sea spray is considered as a possible mechanism of the 'drag reduction' at hurricane conditions. The dependence of heat transfer coefficient CD on the wind speed is not so certain and the role of the mechanism associated with the wave disturbances in the mass transfer is not completely understood. Observations and laboratory data show that this dependence is weaker than for the CD, and there are differences in the character of the dependence in different data sets. The purpose of this paper is investigation of the effect of surface waves on the turbulent exchange of momentum and heat within the laboratory experiment, when wind and wave parameters are maintained and controlled. The effect of spray on turbulent exchange at strong winds is also estimated. A series of experiments to study the processes of turbulent exchange of momentum and heat in a stably stratified temperature turbulent boundary layer air flow over waved water surface were carried out at the Wind - wave stratified flume of IAP RAS, the peculiarity of this experiment was the option to change the surface wave parameters regardless of the speed of the wind flow in the channel. For this purpose a polyethylene net with the variable depth (0.25 mm thick and a cell of 1.6 mm × 1.6mm) has been stretched along the channel. The waves were absent when the net was located at the level of the undisturbed water surface, and had maximum

  7. A high frequent BRCA1 founder mutation identified in the Greenlandic population

    DEFF Research Database (Denmark)

    Harboe, Theresa Larriba; Eiberg, Hans; Kern, Peder

    2009-01-01

    occurring mutations, but founder mutations have been described. In this study we describe a founder mutation with wide spread presence in the Inuit population. We have screened 2,869 persons from Greenland for the presence of a BRCA1 mutation (p.Cys39Gly) only found in the Inuit population. The overall...... carrier frequency was 1.6% in the general population, but the frequency differs geographically from 0.6% on the West coast to 9.7% in the previously isolated population of the East coast. This is to our knowledge the highest population frequency of a BRCA1 mutation ever to be described. To determine...... the clinical relevance of the mutation, we have examined ten breast cancer patients and nine ovarian cancer patients from Greenland for the presence of the p.Cys39Gly mutation. We found three ovarian cancer patients (33%) and one breast cancer patient (10%) carrying the mutation. The high number of women...

  8. A Dutch Fanconi Anemia FANCC Founder Mutation in Canadian Manitoba Mennonites

    Directory of Open Access Journals (Sweden)

    Yne de Vries

    2012-01-01

    Full Text Available Fanconi anemia (FA is a recessive DNA instability disorder associated with developmental abnormalities, bone marrow failure, and a predisposition to cancer. Based on their sensitivity to DNA cross-linking agents, FA cells have been assigned to 15 complementation groups, and the associated genes have been identified. Founder mutations have been found in different FA genes in several populations. The majority of Dutch FA patients belongs to complementation group FA-C. Here, we report 15 patients of Dutch ancestry and a large Canadian Manitoba Mennonite kindred carrying the FANCC c.67delG mutation. Genealogical investigation into the ancestors of the Dutch patients shows that these ancestors lived in four distinct areas in The Netherlands. We also show that the Dutch and Manitoba Mennonite FANCC c.67delG patients share the same haplotype surrounding this mutation, indicating a common founder.

  9. Momir H. Polenakovic - Founder of the Nephrology Associations in the Republic of Macedonia.

    Science.gov (United States)

    Spasovski, Goce; Stojceva-Taneva, Olivera

    2015-01-01

    Acad. Momir Polenakovic has devoted his life and work in the diagnosis and treatment of kidney patients, as well as in research of kidney disease. The great experience he has acquired in the work with kidney patients, and after the visit to the most renowned nephrology centers in Europe and the world, he has transferred it to his colleagues through the work in the medical and nephrology associations. The work of the associations was in fact a successful education of young doctors and specialists. Among his most distinguished positions, we can mention: President of the Macedonian Medical Association, founder and President of the MSNDTAO, President of the Yugoslav Society of Nephrology, founder and President of BANTAO, as well as member of the Boards of ESAO and ERA-EDTA. He has received a lot of recognitions for his work achievements.

  10. Fabrication of Ge Nanocrystals Doped Silica-on-Silicon Waveguides and Observation of Their Strong Quantum Confinement Effect

    DEFF Research Database (Denmark)

    Ou, Haiyan; Rottwitt, Karsten

    2008-01-01

    Standard silica-on-silicon waveguides with a core doped by Ge nanocrystals were fabricated using PECVD and RIE. Transmission of the waveguide was measured, and strong absorption peaks at 1056.8 nm, 1406 nm and 1263.2 nm were observed.......Standard silica-on-silicon waveguides with a core doped by Ge nanocrystals were fabricated using PECVD and RIE. Transmission of the waveguide was measured, and strong absorption peaks at 1056.8 nm, 1406 nm and 1263.2 nm were observed....

  11. Corporate Governance in Brazilian Companies: The Influence of the Founder in the Financial Decisions.

    OpenAIRE

    Segura, Liliane; Formigoni, Henrique; Abreu, Rute; David, Fátima

    2017-01-01

    All over the world, corporate governance is adopting a new process of leadership and simultaneously propagating responsible governance for the welfare of stakeholders. This research has allowed us to identify new directions for future research. It examines the influence of several contextual factors in the framework of the financial decisions, where company has the right to have a transparent accountability, based on the influence of the founder, dispersion and type of ownershi...

  12. Mitochondrial Genome Diversity of Native Americans Supports a Single Early Entry of Founder Populations into America

    OpenAIRE

    Silva Jr., Wilson A.; Bonatto, Sandro L.; Holanda, Adriano J.; Ribeiro-dos-Santos, Andrea K.; Paixão, Beatriz M.; Goldman, Gustavo H.; Abe-Sandes, Kiyoko; Rodriguez-Delfin, Luis; Barbosa, Marcela; Paçó-Larson, Maria Luiza; Petzl-Erler, Maria Luiza; Valente, Valeria; Santos, Sidney E. B.; Zago, Marco A.

    2002-01-01

    There is general agreement that the Native American founder populations migrated from Asia into America through Beringia sometime during the Pleistocene, but the hypotheses concerning the ages and the number of these migrations and the size of the ancestral populations are surrounded by controversy. DNA sequence variations of several regions of the genome of Native Americans, especially in the mitochondrial DNA (mtDNA) control region, have been studied as a tool to help answer these questions...

  13. Ancient founder mutation is responsible for Imerslund-Gräsbeck Syndrome among diverse ethnicities.

    Science.gov (United States)

    Beech, Cameron M; Liyanarachchi, Sandya; Shah, Nidhi P; Sturm, Amy C; Sadiq, May F; de la Chapelle, Albert; Tanner, Stephan M

    2011-11-13

    Imerslund-Gräsbeck syndrome (IGS) was described just over 50 years ago by Olga Imerslund and Ralph Gräsbeck and colleagues. IGS is caused by specific malabsorption of cobalamin (Cbl) due to bi-allelic mutations in either the cubilin gene (CUBN) or the human amnionless homolog (AMN). Mutations in the two genes are commonly seen in founder populations or in societies with a high degree of consanguineous marriages. One particular mutation in AMN, c.208-2A>G, causing an out-of-frame loss of exon 4 in the mRNA, is responsible for some 15% of IGS cases globally. We present evidence that this founder mutation causes a substantial percentage of cases among diverse ethnicities and that the mutation is as old as human civilization. Partial genotyping indicated a founder event but its presence in diverse peoples of Arabic, Turkish, Jewish, and Hispanic ancestry suggested that the mutation might be recurrent. We therefore studied the flanking sequence spanning 3.5 Mb to elucidate the origin of the haplotype and estimate the age of the mutation using a Bayesian inference method based on observed linkage disequilibrium. The mutation's distribution, the size of the shared haplotype, and estimates of growth rate and carrier frequency indicated that the mutation was a single prehistoric event. Dating back to the ancient Middle East around 11,600 BC, the mutation predates the advent of writing, farming, and the monotheistic religions of the region. This mutation causes over 50% of the IGS cases among Arabic, Turkish, and Sephardic Jewish families, making it a primary target for genetic screening among diverse IGS cases originating from the Middle East. Thus, rare founder mutations may cause a substantial number of cases, even among diverse ethnicities not usually thought to be related.

  14. Effects of obesity and body fat distribution on lipids and lipoproteins in nondiabetic American Indians: The Strong Heart Study.

    Science.gov (United States)

    Hu, D; Hannah, J; Gray, R S; Jablonski, K A; Henderson, J A; Robbins, D C; Lee, E T; Welty, T K; Howard, B V

    2000-09-01

    To examine the relationship between obesity and lipoprotein profiles and compare the effects of total obesity and central adiposity on lipids/lipoproteins in American Indians. Participants were 773 nondiabetic American Indian women and 739 men aged 45 to 74 years participating in the Strong Heart Study. Total obesity was estimated using body mass index (BMI). Central obesity was measured as waist circumference. Lipoprotein measures included triglycerides, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, apolipoprotein AI (apoAI), and apolipoprotein B (apoB). Partial and canonical correlation analyses were used to examine the associations between obesity and lipids/ lipoproteins. Women were more obese than men in Arizona (median BMI 32.1 vs. 29.2 kg/m2) and South Dakota and North Dakota (28.3 vs. 28.0 kg/m2), but there was no sex difference in waist circumference. Men had higher apoB and lower apoAI levels than did women. In women, when adjusted for center, gender, and age, BMI was significantly related to HDL cholesterol (r = -0.24, p HDL cholesterol (r = -0.23, p correlated with triglycerides (r = 0.30, p correlated with HDL cholesterol (r = -0.35, p HDL cholesterol decreased with waist circumference (r = -0.36, p correlation analysis, waist circumference received a greater weight (0.86) than did BMI (0.17) in women. However, the canonical weights were similar for waist (0.46) and BMI (0.56) in men. Only HDL cholesterol (-1.02) carried greater weight in women, whereas in men, triglycerides (0.50), and HDL cholesterol (-0.64) carried a large amount of weight. All the correlation coefficients between BMI, waist circumference, and the first canonical variable of lipids/lipoproteins or between the individual lipid/lipoprotein variables and the first canonical variable of obesity were smaller in women than in men. Triglycerides and HDL cholesterol showed clinically meaningful changes with BMI and waist circumference in men. All

  15. The scribe of the founder's inscription of Saint Sava in Studenica

    Directory of Open Access Journals (Sweden)

    Špadijer Irena

    2006-01-01

    Full Text Available The founder's inscription situated at the foot of the tambour in the Church of the Virgin in Studenica originating from 1208/9, is one of the oldest dated specimens of Serbian literacy. It was uncovered in 1951, during the conservation works in the monastery. Former research (conducted by Dj. Trifunović, has ascertained that inscriptions on the scrolls, books and frescoes in the monastery were written by the Greek artists who decorated the church. Scribal errors indicate beyond any doubt that Slavic was not the mother tongue of the scribes, and that they were not, or at least not sufficiently, familiar with the orthography of this language. In this paper the main focus has been directed at the founder's inscription, which has been put under detailed orthographic and palaeographic scrutiny. The morphology of some letters — the Greek "K", non-distinguishing between ižica (ippsilon and the Cyrillic "Č" — clearly indicates that in all probability the author of the inscription was a Greek, perhaps the very painter who signed his name in the Greek language on the Mandelion beneath the large founder's inscription.

  16. FKRP mutations, including a founder mutation, cause phenotype variability in Chinese patients with dystroglycanopathies.

    Science.gov (United States)

    Fu, Xiaona; Yang, Haipo; Wei, Cuijie; Jiao, Hui; Wang, Shuo; Yang, Yanling; Han, Chunxi; Wu, Xiru; Xiong, Hui

    2016-12-01

    Mutations in the fukutin-related protein (FKRP) gene have been associated with dystroglycanopathies, which are common in Europe but rare in Asia. Our study aimed to retrospectively analyze and characterize the clinical, myopathological and genetic features of 12 Chinese patients with FKRP mutations. Three patients were diagnosed with congenital muscular dystrophy type 1C (MDC1C) and nine patients were diagnosed with limb girdle muscular dystrophy type 2I (LGMD2I). Three muscle biopsy specimens had dystrophic changes and reduced glycosylated α-dystroglycan staining, and two showed reduced expression of laminin α2. Two known and 13 novel mutations were identified in our single center cohort. Interestingly, the c.545A>G mutation was found in eight of the nine LGMD2I patients as a founder mutation and this founder mutation in Chinese patients differs from the one seen in European patients. Moreover, patients homozygous for the c.545A>G mutation were clinically asymptomatic, a less severe phenotype than in compound heterozygous patients with the c.545A>G mutation. The 13 novel mutations of FKRP significantly expanded the mutation spectrum of MDC1C and LGMD2I, and the different founder mutations indicate the ethnic difference in FKRP mutations.

  17. Clinical applications and implications of common and founder mutations in Indian subpopulations.

    Science.gov (United States)

    Ankala, Arunkanth; Tamhankar, Parag M; Valencia, C Alexander; Rayam, Krishna K; Kumar, Manisha M; Hegde, Madhuri R

    2015-01-01

    South Asian Indians represent a sixth of the world's population and are a racially, geographically, and genetically diverse people. Their unique anthropological structure, prevailing caste system, and ancient religious practices have all impacted the genetic composition of most of the current-day Indian population. With the evolving socio-religious and economic activities of the subsects and castes, endogamous and consanguineous marriages became a commonplace. Consequently, the frequency of founder mutations and the burden of heritable genetic disorders rose significantly. Specifically, the incidence of certain autosomal-recessive disorders is relatively high in select Indian subpopulations and communities that share common recent ancestry. Although today clinical genetics and molecular diagnostic services are making inroads in India, the high costs associated with the technology and the tests often keep patients from an exact molecular diagnosis, making more customized and tailored tests, such as those interrogating the most common and founder mutations or those that cater to select sects within the population, highly attractive. These tests offer a quick first-hand affordable diagnostic and carrier screening tool. Here, we provide a comprehensive catalog of known common mutations and founder mutations in the Indian population and discuss them from a molecular, clinical, and historical perspective. © 2014 WILEY PERIODICALS, INC.

  18. SOLVENT EFFECTS IN THE LIQUID-PHASE HYDRATION OF CYCLOHEXENE CATALYZED BY A MACROPOROUS STRONG ACID ION-EXCHANGE RESIN

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    1992-01-01

    The liquid-phase hydration of cyclohexene, a pseudo first order reversible reaction catalyzed by a strong acid ion exchange resin, macroporous Amberlite XE 307, was investigated in solvent mixtures of water and sulfolane. A decrease by a factor of 3 and 6 is observed in the experimentally measured

  19. The Effects of Building Strong Families: A Healthy Marriage and Relationship Skills Education Program for Unmarried Parents

    Science.gov (United States)

    Wood, Robert G.; McConnell, Sheena; Moore, Quinn; Clarkwest, Andrew; Hsueh, JoAnn

    2012-01-01

    This article examines the impacts of Building Strong Families, a healthy marriage and relationship skills education program serving unmarried parents who were expecting or had recently had a baby. Based on a random assignment research design, the analysis uses survey data from more than 4,700 couples across eight research sites to estimate program…

  20. The frequency of BRCA1 founder mutation c.5266dupC (5382insC) in breast cancer patients from Ukraine

    OpenAIRE

    Gorodetska, Ielizaveta; Serga, Svitlana; Levkovich, Natalia; Lahuta, Tetiana; Ostapchenko, Ludmila; Demydov, Serhyi; Anikusko, Nikolay; Cheshuk, Valeriy; Smolanka, Ivan; Sklyar, Svitlana; Polenkov, Serhyi; Boichenko, Oleksander; Kozeretska, Iryna

    2015-01-01

    Germ-line mutations in several genes, such as BRCA1 and BRCA2, are known to increase the risk of breast cancer. These heritable mutations are unequally represented among populations with different ethnic background due to founder effects and thereby contribute to differences in breast cancer rates in different populations. The BRCA1 mutation c.5266dupC (also known as 5382insC or 5385insC) was detected in a sample of 193 breast cancer patients in Ukraine by multiplex mutagenically separated PC...

  1. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Directory of Open Access Journals (Sweden)

    Damien C Tully

    2016-05-01

    Full Text Available Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU, we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  2. Differences in the Selection Bottleneck between Modes of Sexual Transmission Influence the Genetic Composition of the HIV-1 Founder Virus.

    Science.gov (United States)

    Tully, Damien C; Ogilvie, Colin B; Batorsky, Rebecca E; Bean, David J; Power, Karen A; Ghebremichael, Musie; Bedard, Hunter E; Gladden, Adrianne D; Seese, Aaron M; Amero, Molly A; Lane, Kimberly; McGrath, Graham; Bazner, Suzane B; Tinsley, Jake; Lennon, Niall J; Henn, Matthew R; Brumme, Zabrina L; Norris, Philip J; Rosenberg, Eric S; Mayer, Kenneth H; Jessen, Heiko; Kosakovsky Pond, Sergei L; Walker, Bruce D; Altfeld, Marcus; Carlson, Jonathan M; Allen, Todd M

    2016-05-01

    Due to the stringent population bottleneck that occurs during sexual HIV-1 transmission, systemic infection is typically established by a limited number of founder viruses. Elucidation of the precise forces influencing the selection of founder viruses may reveal key vulnerabilities that could aid in the development of a vaccine or other clinical interventions. Here, we utilize deep sequencing data and apply a genetic distance-based method to investigate whether the mode of sexual transmission shapes the nascent founder viral genome. Analysis of 74 acute and early HIV-1 infected subjects revealed that 83% of men who have sex with men (MSM) exhibit a single founder virus, levels similar to those previously observed in heterosexual (HSX) transmission. In a metadata analysis of a total of 354 subjects, including HSX, MSM and injecting drug users (IDU), we also observed no significant differences in the frequency of single founder virus infections between HSX and MSM transmissions. However, comparison of HIV-1 envelope sequences revealed that HSX founder viruses exhibited a greater number of codon sites under positive selection, as well as stronger transmission indices possibly reflective of higher fitness variants. Moreover, specific genetic "signatures" within MSM and HSX founder viruses were identified, with single polymorphisms within gp41 enriched among HSX viruses while more complex patterns, including clustered polymorphisms surrounding the CD4 binding site, were enriched in MSM viruses. While our findings do not support an influence of the mode of sexual transmission on the number of founder viruses, they do demonstrate that there are marked differences in the selection bottleneck that can significantly shape their genetic composition. This study illustrates the complex dynamics of the transmission bottleneck and reveals that distinct genetic bottleneck processes exist dependent upon the mode of HIV-1 transmission.

  3. Strong coupling effects during X-pulse CPMG experiments recorded on heteronuclear ABX spin systems: artifacts and a simple solution

    International Nuclear Information System (INIS)

    Vallurupalli, Pramodh; Scott, Lincoln; Williamson, James R.; Kay, Lewis E.

    2007-01-01

    Simulation and experiment have been used to establish that significant artifacts can be generated in X-pulse CPMG relaxation dispersion experiments recorded on heteronuclear ABX spin-systems, such as 13 C i - 13 C j - 1 H, where 13 C i and 13 C j are strongly coupled. A qualitative explanation of the origin of these artifacts is presented along with a simple method to significantly reduce them. An application to the measurement of 1 H CPMG relaxation dispersion profiles in an HIV-2 TAR RNA molecule where all ribose sugars are protonated at the 2' position, deuterated at all other sugar positions and 13 C labeled at all sugar carbons is presented to illustrate the problems that strong 13 C- 13 C coupling introduces and a simple solution is proposed

  4. Calculations of the one-body electronic structure of the strongly correlated systems including self-energy effects

    Energy Technology Data Exchange (ETDEWEB)

    Costa-Quintana, J.; Sanchez-Lopez, M.M.; Lopez-Aguilar, F. [Grup d`Electromagnetisme, Edifici Cn, Universitat Autonoma de Barcelona 08193, Bellaterra, Barcelona (Spain)

    1996-10-01

    We give a method to obtain the quasiparticle band structure and renormalized density of states by diagonalizing the interacting system Green function. This method operates for any self-energy approximation appropriated to strongly correlated systems. Application to CeSi{sub 2} and YBa{sub 2}Cu{sub 3}O{sub 7} is analyzed as a probe for this band calculation method. {copyright} {ital 1996 The American Physical Society.}

  5. Effect of Strong Acid Functional Groups on Electrode Rise Potential in Capacitive Mixing by Double Layer Expansion

    KAUST Repository

    Hatzell, Marta C.

    2014-12-02

    © 2014 American Chemical Society. The amount of salinity-gradient energy that can be obtained through capacitive mixing based on double layer expansion depends on the extent the electric double layer (EDL) is altered in a low salt concentration (LC) electrolyte (e.g., river water). We show that the electrode-rise potential, which is a measure of the EDL perturbation process, was significantly (P = 10-5) correlated to the concentration of strong acid surface functional groups using five types of activated carbon. Electrodes with the lowest concentration of strong acids (0.05 mmol g-1) had a positive rise potential of 59 ± 4 mV in the LC solution, whereas the carbon with the highest concentration (0.36 mmol g-1) had a negative rise potential (-31 ± 5 mV). Chemical oxidation of a carbon (YP50) using nitric acid decreased the electrode rise potential from 46 ± 2 mV (unaltered) to -6 ± 0.5 mV (oxidized), producing a whole cell potential (53 ± 1.7 mV) that was 4.4 times larger than that obtained with identical electrode materials (from 12 ± 1 mV). Changes in the EDL were linked to the behavior of specific ions in a LC solution using molecular dynamics and metadynamics simulations. The EDL expanded in the LC solution when a carbon surface (pristine graphene) lacked strong acid functional groups, producing a positive-rise potential at the electrode. In contrast, the EDL was compressed for an oxidized surface (graphene oxide), producing a negative-rise electrode potential. These results established the linkage between rise potentials and specific surface functional groups (strong acids) and demonstrated on a molecular scale changes in the EDL using oxidized or pristine carbons.

  6. Horia Hulubei, father founder of the Institute of Atomic Physics

    International Nuclear Information System (INIS)

    Stratan, G.

    1999-01-01

    Horia Hulubei (b. November 15, 1896, Jassy, d. November 22, 1972, Bucharest) enrolled in 1915 at the University of Jassy, but his studies were interrupted by the WW I. He volunteered first on the Eastern Front, and then in France as a fighter pilot. Wounded and decorated with Legion d'Honneur, he came back to Romania and worked in the field of civil aviation. He graduated in 1926 from the same University with Magna cum Laudae. In 1927, Hulubei went in Paris with a fellowship at the Physical Chemistry Laboratory of Sorbonne and took his Ph. D. in 1933 with Jean Perrin in the field of X-rays spectroscopy, a domain in which he became one of the best specialists of the time. His papers treat a large area of subjects from the multiple Compton effect (predicted and experimentally discovered by him), Raman spectra, the X-ray spectra of gases (obtained for the first time by him in collaboration with Mademoiselle Yvette Cauchois), the identification of elements by X spectroscopy etc. Winner of two prizes of Paris Academy of Sciences, he was elected Corresponding Member of this prestigious French institution. He was also a Directeur de Recherches at the French National Centre of Scientific Research (CNRS). Back in Romania at the beginning of WW II, Hulubei became Professor of Physics, and in 1941, Rector of Bucharest University. After the war, Professor Hulubei dedicated himself to the organization of Romanian research in the field of Physics. The foundation of the Institute of Atomic Physics (IAP) in 1949 in Bucharest was the realization of his dream to build a modern institution of Western type in his own country, tightly connected with the rest of scientific world by international cooperation. Horia Hulubei was practically removed from his directorship of IAP in 1968, following his nomination in a honorary duty, but he remained in a permanent contact with the people formed by him and with the directions of research initiated by him and continued by his followers. The

  7. Strong anisotropic anomalous Hall effect and spin Hall effect in the chiral antiferromagnetic compounds Mn3X (X =Ge , Sn, Ga, Ir, Rh, and Pt)

    Science.gov (United States)

    Zhang, Yang; Sun, Yan; Yang, Hao; Železný, Jakub; Parkin, Stuart P. P.; Felser, Claudia; Yan, Binghai

    2017-02-01

    We have carried out a comprehensive study of the intrinsic anomalous Hall effect and spin Hall effect of several chiral antiferromagnetic compounds Mn3X (X = Ge, Sn, Ga, Ir, Rh and Pt) by ab initio band structure and Berry phase calculations. These studies reveal large and anisotropic values of both the intrinsic anomalous Hall effect and spin Hall effect. The Mn3X materials exhibit a noncollinear antiferromagnetic order which, to avoid geometrical frustration, forms planes of Mn moments that are arranged in a Kagome-type lattice. With respect to these Kagome planes, we find that both the anomalous Hall conductivity (AHC) and the spin Hall conductivity (SHC) are quite anisotropic for any of these materials. Based on our calculations, we propose how to maximize AHC and SHC for different materials. The band structures and corresponding electron filling, that we show are essential to determine the AHC and SHC, are compared for these different compounds. We point out that Mn3Ga shows a large SHC of about 600 (ℏ /e ) (Ωcm) -1 . Our work provides insights into the realization of strong anomalous Hall effects and spin Hall effects in chiral antiferromagnetic materials.

  8. Energy Approach to Nuclei and Atoms in a Strong Laser Field: Stark Effect and Multi-photon Resonances

    International Nuclear Information System (INIS)

    Glushkov, A. V.; Khetselius, O. Yu.; Svinarenko, A. A.; Lovett, L.

    2010-01-01

    A consistent energy approach to nuclei and atoms in a strong electromagnetic (laser) field is presented. The photon emission and absorption lines are described by the moments of different orders, which are calculated with the use of the Gell-Mann and Low S-matrix adiabatic formalism. In relativistic version the Gell-Mann and Low formulae expresses an imaginary part of the energy shift ImE through the scattering matrix, including interaction of quantum system as with laser field as with a field of photon vacuum.

  9. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber

    OpenAIRE

    Cao, Ting-Ting; Wang, Yuan-Jing; Zhang, Yu-Qing

    2013-01-01

    Strongly alkaline electrolyzed water (SAEW) was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+) concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V) for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile prope...

  10. Vector chirality for effective total momentum Jeff in a nonfrustrated Mott insulator: Effects of strong spin-orbit coupling and broken inversion symmetry

    Science.gov (United States)

    Arakawa, Naoya

    2016-11-01

    I propose the emergence of the spin-orbital-coupled vector chirality in a nonfrustrated Mott insulator with the strong spin-orbit coupling due to a b -plane's inversion-symmetry (IS) breaking. I derive the superexchange interactions for a t2 g-orbital Hubbard model on a square lattice with the strong spin-orbit coupling and the IS-breaking-induced hopping integrals, and explain the microscopic origins of the Dzyaloshinsky-Moriya (DM) -type and the Kitaev-type interactions. Then, by adopting the mean-field approximation to a minimal model including only the Heisenberg-type and the DM-type nearest-neighbor interactions, I show that the IS breaking causes the spin-orbital-coupled chirality as a result of stabilizing the screw state. I also highlight the limit of the hard-pseudospin approximation in discussing the stability of the screw states in the presence of both the DM-type and the Kitaev-type interactions, and discuss its meaning. I finally discuss the effects of tetragonal crystal field and Jeff=3/2 states, and the application to the iridates near the [001 ] surface of Sr2IrO4 and the interface between Sr2IrO4 and Sr3Ir2O7 .

  11. Seasonal climate manipulations have only minor effects on litter decomposition rates and N dynamics but strong effects on litter P dynamics of sub-arctic bog species.

    Science.gov (United States)

    Aerts, R; Callaghan, T V; Dorrepaal, E; van Logtestijn, R S P; Cornelissen, J H C

    2012-11-01

    Litter decomposition and nutrient mineralization in high-latitude peatlands are constrained by low temperatures. So far, little is known about the effects of seasonal components of climate change (higher spring and summer temperatures, more snow which leads to higher winter soil temperatures) on these processes. In a 4-year field experiment, we manipulated these seasonal components in a sub-arctic bog and studied the effects on the decomposition and N and P dynamics of leaf litter of Calamagrostis lapponica, Betula nana, and Rubus chamaemorus, incubated both in a common ambient environment and in the treatment plots. Mass loss in the controls increased in the order Calamagrostis Litter chemistry showed within each incubation environment only a few and species-specific responses. Compared to the interspecific differences, they resulted in only moderate climate treatment effects on mass loss and these differed among seasons and species. Neither N nor P mineralization in the litter were affected by the incubation environment. Remarkably, for all species, no net N mineralization had occurred in any of the treatments during 4 years. Species differed in P-release patterns, and summer warming strongly stimulated P release for all species. Thus, moderate changes in summer temperatures and/or winter snow addition have limited effects on litter decomposition rates and N dynamics, but summer warming does stimulate litter P release. As a result, N-limitation of plant growth in this sub-arctic bog may be sustained or even further promoted.

  12. Strong Coupling Holography

    CERN Document Server

    Dvali, Gia

    2009-01-01

    We show that whenever a 4-dimensional theory with N particle species emerges as a consistent low energy description of a 3-brane embedded in an asymptotically-flat (4+d)-dimensional space, the holographic scale of high-dimensional gravity sets the strong coupling scale of the 4D theory. This connection persists in the limit in which gravity can be consistently decoupled. We demonstrate this effect for orbifold planes, as well as for the solitonic branes and string theoretic D-branes. In all cases the emergence of a 4D strong coupling scale from bulk holography is a persistent phenomenon. The effect turns out to be insensitive even to such extreme deformations of the brane action that seemingly shield 4D theory from the bulk gravity effects. A well understood example of such deformation is given by large 4D Einstein term in the 3-brane action, which is known to suppress the strength of 5D gravity at short distances and change the 5D Newton's law into the four-dimensional one. Nevertheless, we observe that the ...

  13. Strong-coupling approximations

    International Nuclear Information System (INIS)

    Abbott, R.B.

    1984-03-01

    Standard path-integral techniques such as instanton calculations give good answers for weak-coupling problems, but become unreliable for strong-coupling. Here we consider a method of replacing the original potential by a suitably chosen harmonic oscillator potential. Physically this is motivated by the fact that potential barriers below the level of the ground-state energy of a quantum-mechanical system have little effect. Numerically, results are good, both for quantum-mechanical problems and for massive phi 4 field theory in 1 + 1 dimensions. 9 references, 6 figures

  14. Strong interaction and QFD

    International Nuclear Information System (INIS)

    Ebata, T.

    1981-01-01

    With an assumed weak multiplet structure for bosonic hadrons, which is consistent with the ΔI = 1/2 rule, it is shown that the strong interaction effective hamiltonian is compatible with the weak SU(2) x U(1) gauge transformation. Especially the rho-meson transforms as a triplet under SU(2)sub(w), and this is the origin of the rho-photon analogy. It is also shown that the existence of the non-vanishing Cabibbo angle is a necessary condition for the absence of the exotic hadrons. (orig.)

  15. Multiorbital effects in strong-field ionization and dissociation of aligned polar molecules CH3I and CH3Br

    Science.gov (United States)

    Luo, Sizuo; Zhou, Shushan; Hu, Wenhui; Li, Xiaokai; Ma, Pan; Yu, Jiaqi; Zhu, Ruihan; Wang, Chuncheng; Liu, Fuchun; Yan, Bing; Liu, Aihua; Yang, Yujun; Guo, Fuming; Ding, Dajun

    2017-12-01

    Controlling the molecular axis offers additional ways to study molecular ionization and dissociation in strong laser fields. We measure the ionization and dissociation yields of aligned polar CH3X (X =I , Br) molecules in a linearly polarized femtosecond laser field. The current data show that maximum ionization occurs when the laser polarization is perpendicular to the molecular C -X axis, and dissociation prefers to occur at the laser polarization parallel to the C -X axis. The observed angular distributions suggest that the parent ions are generated by ionization from the HOMO. The angular distribution of fragment ions indicates that dissociation occurs mainly from an ionic excited state produced by ionization from the HOMO-1.

  16. Effect of the strong coupling on the exchange bias field in IrMn/Py/Ru/Co spin valves

    Science.gov (United States)

    Tarazona, H. S.; Alayo, W.; Landauro, C. V.; Quispe-Marcatoma, J.

    2018-01-01

    The IrMn/Py/Ru/Co (Py = Ni81Fe19) spin valves have been produced by sputtering deposition and analyzed by magnetization measurements and a theoretical modelling of their exchange interactions, based on the macro-spin model. The Ru thickness was grown between 6 and 22 Å, which is small enough to promote strong indirect coupling between Py and Co. Results of measurements showed a large and gradual change in the shape of hysteresis loops when the Ru thickness was varied. The theoretical analysis, using numerical calculations based on the gradient conjugate method, provides the exchange coupling constants (bilinear and biquadratic), the exchange anisotropy fields and the magnetic anisotropy fields (uniaxial and rotatable). The exchange bias fields of spin valves were compared to that of a IrMn/Py bilayer. We found that the difference between these fields oscillates with Ru thickness in the same manner as the bilinear coupling constants.

  17. Effects of a strong magnetic field on internal gravity waves: trapping, phase mixing, reflection and dynamical chaos

    Science.gov (United States)

    Loi, Shyeh Tjing; Papaloizou, John C. B.

    2018-04-01

    The spectrum of oscillation modes of a star provides information not only about its material properties (e.g. mean density), but also its symmetries. Spherical symmetry can be broken by rotation and/or magnetic fields. It has been postulated that strong magnetic fields in the cores of some red giants are responsible for their anomalously weak dipole mode amplitudes (the "dipole dichotomy" problem), but a detailed understanding of how gravity waves interact with strong fields is thus far lacking. In this work, we attack the problem through a variety of analytical and numerical techniques, applied to a localised region centred on a null line of a confined axisymmetric magnetic field which is approximated as being cylindrically symmetric. We uncover a rich variety of phenomena that manifest when the field strength exceeds a critical value, beyond which the symmetry is drastically broken by the Lorentz force. When this threshold is reached, the spatial structure of the g-modes becomes heavily altered. The dynamics of wave packet propagation transitions from regular to chaotic, which is expected to fundamentally change the organisation of the mode spectrum. In addition, depending on their frequency and the orientation of field lines with respect to the stratification, waves impinging on different parts of the magnetised region are found to undergo either reflection or trapping. Trapping regions provide an avenue for energy loss through Alfvén wave phase mixing. Our results may find application in various astrophysical contexts, including the dipole dichotomy problem, the solar interior, and compact star oscillations.

  18. Constitutional Mismatch Repair Deficiency in Israel: High Proportion of Founder Mutations in MMR Genes and Consanguinity.

    Science.gov (United States)

    Baris, Hagit N; Barnes-Kedar, Inbal; Toledano, Helen; Halpern, Marisa; Hershkovitz, Dov; Lossos, Alexander; Lerer, Israela; Peretz, Tamar; Kariv, Revital; Cohen, Shlomi; Half, Elizabeth E; Magal, Nurit; Drasinover, Valerie; Wimmer, Katharina; Goldberg, Yael; Bercovich, Dani; Levi, Zohar

    2016-03-01

    Heterozygous germline mutations in any of the mismatch repair (MMR) genes, MLH1, MSH2, MSH6, and PMS2, cause Lynch syndrome (LS), an autosomal dominant cancer predisposition syndrome conferring a high risk of colorectal, endometrial, and other cancers in adulthood. Offspring of couples where both spouses have LS have a 1:4 risk of inheriting biallelic MMR gene mutations. These cause constitutional MMR deficiency (CMMRD) syndrome, a severe recessively inherited cancer syndrome with a broad tumor spectrum including mainly hematological malignancies, brain tumors, and colon cancer in childhood and adolescence. Many CMMRD children also present with café au lait spots and axillary freckling mimicking neurofibromatosis type 1. We describe our experience in seven CMMRD families demonstrating the role and importance of founder mutations and consanguinity on its prevalence. Clinical presentations included brain tumors, colon cancer, lymphoma, and small bowel cancer. In children from two nonconsanguineous Ashkenazi Jewish (AJ) families, the common Ashkenazi founder mutations were detected; these were homozygous in one family and compound heterozygous in the other. In four consanguineous families of various ancestries, different homozygous mutations were identified. In a nonconsanguineous Caucasus/AJ family, lack of PMS2 was demonstrated in tumor and normal tissues; however, mutations were not identified. CMMRD is rare, but, especially in areas where founder mutations for LS and consanguinity are common, pediatricians should be aware of it since they are the first to encounter these children. Early diagnosis will enable tailored cancer surveillance in the entire family and a discussion regarding prenatal genetic diagnosis. © 2015 Wiley Periodicals, Inc.

  19. Expression-guided in silico evaluation of candidate cis regulatory codes for Drosophila muscle founder cells.

    Directory of Open Access Journals (Sweden)

    Anthony A Philippakis

    2006-05-01

    Full Text Available While combinatorial models of transcriptional regulation can be inferred for metazoan systems from a priori biological knowledge, validation requires extensive and time-consuming experimental work. Thus, there is a need for computational methods that can evaluate hypothesized cis regulatory codes before the difficult task of experimental verification is undertaken. We have developed a novel computational framework (termed "CodeFinder" that integrates transcription factor binding site and gene expression information to evaluate whether a hypothesized transcriptional regulatory model (TRM; i.e., a set of co-regulating transcription factors is likely to target a given set of co-expressed genes. Our basic approach is to simultaneously predict cis regulatory modules (CRMs associated with a given gene set and quantify the enrichment for combinatorial subsets of transcription factor binding site motifs comprising the hypothesized TRM within these predicted CRMs. As a model system, we have examined a TRM experimentally demonstrated to drive the expression of two genes in a sub-population of cells in the developing Drosophila mesoderm, the somatic muscle founder cells. This TRM was previously hypothesized to be a general mode of regulation for genes expressed in this cell population. In contrast, the present analyses suggest that a modified form of this cis regulatory code applies to only a subset of founder cell genes, those whose gene expression responds to specific genetic perturbations in a similar manner to the gene on which the original model was based. We have confirmed this hypothesis by experimentally discovering six (out of 12 tested new CRMs driving expression in the embryonic mesoderm, four of which drive expression in founder cells.

  20. Shear wave anisotropy beneath the Sierra Nevada range: Implications for lithospheric foundering and upper mantle flow

    Science.gov (United States)

    Badger, N. B.; Bastow, I. D.; Owens, T. J.; Zandt, G.; Jones, C. H.; Gilbert, H.

    2007-12-01

    Recent work asserts that the garnet-rich Sierra Nevada batholith root has undergone foundering since the early Cenozoic. The Sierra Nevada EarthScope Project (SNEP), undertaken to gain a better understanding of this phenomena, consists of a network of ~80 broadband seismometers spaced at ~25 km from ~37.0N to 40.5N. We use the Silver and Chan method to determine shear wave splitting parameters (dt and φ) for teleseismic SKS phases recorded at SNEP and US Array Transportable Array stations in the region. We find dt>1.1s and φ approximately in the E-NE direction over most of the batholith. Splitting of this magnitude cannot be accounted for solely in the crust, and our results, therefore, have significant implications for upper mantle flow beneath the region. At latitude ~39N to 40N, from the western Sierra Nevada range across our study area to central Nevada, we observe dtGorda-Juan de Fuca Plate. Such a flow pattern is also consistent with the circular pattern of splitting measurements that exist in the broader California and Western Nevada region. We observe subtle variations in splitting parameters as a function of backazimuth primarily at stations situated on the western foothills of the Sierra Nevada. These complexities may be indicative of either a two-layer or dipping layer structure beneath the batholith that may be associated with on- going lithospheric foundering beneath the Sierran range. Additionally, in the southern part of our study area, we note a reduction in dt for arrivals that sample the high Vp Isabella anomaly - an upper mantle downwelling thought to be a result of recent lithospheric foundering.

  1. Rayleigh and S wave tomography constraints on subduction termination and lithospheric foundering in central California

    Science.gov (United States)

    Jiang, Chengxin; Schmandt, Brandon; Hansen, Steven M.; Dougherty, Sara L.; Clayton, Robert W.; Farrell, Jamie; Lin, Fan-Chi

    2018-01-01

    The crust and upper mantle structure of central California have been modified by subduction termination, growth of the San Andreas plate boundary fault system, and small-scale upper mantle convection since the early Miocene. Here we investigate the contributions of these processes to the creation of the Isabella Anomaly, which is a high seismic velocity volume in the upper mantle. There are two types of hypotheses for its origin. One is that it is the foundered mafic lower crust and mantle lithosphere of the southern Sierra Nevada batholith. The alternative suggests that it is a fossil slab connected to the Monterey microplate. A dense broadband seismic transect was deployed from the coast to the western Sierra Nevada to fill in the least sampled areas above the Isabella Anomaly, and regional-scale Rayleigh and S wave tomography are used to evaluate the two hypotheses. New shear velocity (Vs) tomography images a high-velocity anomaly beneath coastal California that is sub-horizontal at depths of ∼40–80 km. East of the San Andreas Fault a continuous extension of the high-velocity anomaly dips east and is located beneath the Sierra Nevada at ∼150–200 km depth. The western position of the Isabella Anomaly in the uppermost mantle is inconsistent with earlier interpretations that the Isabella Anomaly is connected to actively foundering foothills lower crust. Based on the new Vs images, we interpret that the Isabella Anomaly is not the dense destabilized root of the Sierra Nevada, but rather a remnant of Miocene subduction termination that is translating north beneath the central San Andreas Fault. Our results support the occurrence of localized lithospheric foundering beneath the high elevation eastern Sierra Nevada, where we find a lower crustal low Vs layer consistent with a small amount of partial melt. The high elevations relative to crust thickness and lower crustal low Vs zone are consistent with geological inferences that lithospheric foundering drove

  2. Rayleigh and S wave tomography constraints on subduction termination and lithospheric foundering in central California

    Science.gov (United States)

    Jiang, Chengxin; Schmandt, Brandon; Hansen, Steven M.; Dougherty, Sara L.; Clayton, Robert W.; Farrell, Jamie; Lin, Fan-Chi

    2018-04-01

    The crust and upper mantle structure of central California have been modified by subduction termination, growth of the San Andreas plate boundary fault system, and small-scale upper mantle convection since the early Miocene. Here we investigate the contributions of these processes to the creation of the Isabella Anomaly, which is a high seismic velocity volume in the upper mantle. There are two types of hypotheses for its origin. One is that it is the foundered mafic lower crust and mantle lithosphere of the southern Sierra Nevada batholith. The alternative suggests that it is a fossil slab connected to the Monterey microplate. A dense broadband seismic transect was deployed from the coast to the western Sierra Nevada to fill in the least sampled areas above the Isabella Anomaly, and regional-scale Rayleigh and S wave tomography are used to evaluate the two hypotheses. New shear velocity (Vs) tomography images a high-velocity anomaly beneath coastal California that is sub-horizontal at depths of ∼40-80 km. East of the San Andreas Fault a continuous extension of the high-velocity anomaly dips east and is located beneath the Sierra Nevada at ∼150-200 km depth. The western position of the Isabella Anomaly in the uppermost mantle is inconsistent with earlier interpretations that the Isabella Anomaly is connected to actively foundering foothills lower crust. Based on the new Vs images, we interpret that the Isabella Anomaly is not the dense destabilized root of the Sierra Nevada, but rather a remnant of Miocene subduction termination that is translating north beneath the central San Andreas Fault. Our results support the occurrence of localized lithospheric foundering beneath the high elevation eastern Sierra Nevada, where we find a lower crustal low Vs layer consistent with a small amount of partial melt. The high elevations relative to crust thickness and lower crustal low Vs zone are consistent with geological inferences that lithospheric foundering drove uplift

  3. Bottlenecks in HIV-1 transmission: insights from the study of founder viruses

    Science.gov (United States)

    Joseph, Sarah B.; Swanstrom, Ronald; Kashuba, Angela D. M.; Cohen, Myron S.

    2016-01-01

    HIV-1 infection typically results from the transmission of a single viral variant, the transmitted/founder (T/F) virus. Studies of these HIV-1 variants provide critical information about the transmission bottlenecks and the selective pressures acting on the virus in the transmission fluid and in the recipient tissues. These studies reveal that T/F virus phenotypes are shaped by stochastic and selective forces that restrict transmission and may be targets for prevention strategies. In this Review, we highlight how studies of T/F viruses contribute to a better understanding of the biology of HIV-1 transmission and discuss how these findings affect HIV-1 prevention strategies. PMID:26052661

  4. The contribution of founder mutations to early-onset breast cancer in French-Canadian women.

    Science.gov (United States)

    Ghadirian, P; Robidoux, A; Zhang, P; Royer, R; Akbari, M; Zhang, S; Fafard, E; Costa, M; Martin, G; Potvin, C; Patocskai, E; Larouche, N; Younan, R; Nassif, E; Giroux, S; Narod, S A; Rousseau, F; Foulkes, W D

    2009-11-01

    In an ethnically-homogeneous population, it is valuable to identify founder mutations in cancer-predisposing genes. Founder mutations have been found in four breast-cancer-predisposing genes in French-Canadian breast cancer families. The frequencies of the mutant alleles have been measured neither in a large series of unselected breast cancer patients from Quebec, nor in healthy controls. These estimates are necessary to measure their contribution to the hereditary burden of breast cancer in Quebec and to help develop genetic screening policies which are appropriate for the province. We studied 564 French-Canadian women with early-onset invasive breast cancer who were treated at a single Montreal hospital. Patients had been diagnosed at age 50 or less, and were ascertained between 2004 and 2008. We screened all 564 patients for nine founder mutations: four in BRCA1, three in BRCA2 and one each in PALB2 and CHEK2. We also studied 6433 DNA samples from newborn infants from the Quebec City area to estimate the frequency of the nine variant alleles in the French-Canadian population. We identified a mutation in 36 of the 564 breast cancer cases (6.4%) and in 35 of 6443 controls (0.5%). In the breast cancer patients, the majority of mutations were in BRCA2 (54%). However, in the general population (newborn infants), the majority of mutations were in CHEK2 (54%). The odds ratio for breast cancer to age 50, given a BRCA1 mutation, was 10.1 (95% CI: 3.7-28) and given a BRCA2 mutation was 29.5 (95% CI: 12.9-67). The odds ratio for breast cancer to age 50, given a CHEK2 mutation, was 3.6 (95% CI: 1.4-9.1). One-half of the women with a mutation had a first- or second-degree relative diagnosed with breast or ovarian cancer. Thus, it can be concluded that a predisposing mutation in BRCA1, BRCA2, CHEK2 or PALB2 is present in approximately 6% of French-Canadian women with early-onset breast cancer. It is reasonable to offer screening for founder mutations to all French

  5. Quantitative Trait Loci and Maternal Effects Affecting the Strong Grain Dormancy of Wild Barley (Hordeum vulgare ssp. spontaneum

    Directory of Open Access Journals (Sweden)

    Shingo Nakamura

    2017-10-01

    Full Text Available Wild barley (Hordeum vulgare ssp. spontaneum has strong grain dormancy, a trait that may enhance its survival in non-cultivated environments; by contrast, cultivated barley (Hordeum vulgare ssp. vulgare has weaker dormancy, allowing uniform germination in cultivation. Malting barley cultivars have been bred for especially weak dormancy to optimize their use in malt production. Here, we analyzed the genetic mechanism of this difference in seed dormancy, using recombinant inbred lines (RILs derived from a cross between the wild barley accession ‘H602’ and the malting barley cultivar ‘Kanto Nakate Gold (KNG’. Grains of H602 and KNG harvested at physiological maturity and dried at 30°C for 7 days had germination of approximately 0 and 100%, respectively. Analysis of quantitative trait loci (QTL affecting grain dormancy identified the well-known major dormancy QTL SD1 and SD2 (located near the centromeric region and at the distal end of the long arm of chromosome 5H, respectively, and QTL at the end of the long arm of chromosome 4H and in the middle of the long arm of chromosome 5H. We designated these four QTL Qsd1-OK, Qsd2-OK, Qsdw-4H, and Qsdw-5H, and they explained approximately 6, 38, 3, and 13% of the total phenotypic variation, respectively. RILs carrying H602 alleles showed increased dormancy levels for all QTL. The QTL acted additively and did not show epistasis or QTL–environment interactions. Comparison of QTL locations indicated that all QTL except Qsdw-5H are likely the same as the QTL previously detected in the doubled haploid population from a cross between the malting cultivar ‘Haruna Nijo’ and ‘H602.’ We further examined Qsd2-OK and Qsdw-5H by analyzing the segregation of phenotypes and genotypes of F2 progenies derived from crosses between RILs carrying specific segments of chromosome 5H from H602 in the KNG background. This analysis confirmed that the two genomic regions corresponding to these QTL are involved in

  6. Quantitative Trait Loci and Maternal Effects Affecting the Strong Grain Dormancy of Wild Barley (Hordeum vulgaressp.spontaneum).

    Science.gov (United States)

    Nakamura, Shingo; Pourkheirandish, Mohammad; Morishige, Hiromi; Sameri, Mohammad; Sato, Kazuhiro; Komatsuda, Takao

    2017-01-01

    Wild barley ( Hordeum vulgare ssp. spontaneum ) has strong grain dormancy, a trait that may enhance its survival in non-cultivated environments; by contrast, cultivated barley ( Hordeum vulgare ssp. vulgare ) has weaker dormancy, allowing uniform germination in cultivation. Malting barley cultivars have been bred for especially weak dormancy to optimize their use in malt production. Here, we analyzed the genetic mechanism of this difference in seed dormancy, using recombinant inbred lines (RILs) derived from a cross between the wild barley accession 'H602' and the malting barley cultivar 'Kanto Nakate Gold (KNG)'. Grains of H602 and KNG harvested at physiological maturity and dried at 30°C for 7 days had germination of approximately 0 and 100%, respectively. Analysis of quantitative trait loci (QTL) affecting grain dormancy identified the well-known major dormancy QTL SD1 and SD2 (located near the centromeric region and at the distal end of the long arm of chromosome 5H, respectively), and QTL at the end of the long arm of chromosome 4H and in the middle of the long arm of chromosome 5H. We designated these four QTL Qsd1-OK , Qsd2-OK , Qsdw-4H , and Qsdw-5H , and they explained approximately 6, 38, 3, and 13% of the total phenotypic variation, respectively. RILs carrying H602 alleles showed increased dormancy levels for all QTL. The QTL acted additively and did not show epistasis or QTL-environment interactions. Comparison of QTL locations indicated that all QTL except Qsdw-5H are likely the same as the QTL previously detected in the doubled haploid population from a cross between the malting cultivar 'Haruna Nijo' and 'H602.' We further examined Qsd2-OK and Qsdw-5H by analyzing the segregation of phenotypes and genotypes of F 2 progenies derived from crosses between RILs carrying specific segments of chromosome 5H from H602 in the KNG background. This analysis confirmed that the two genomic regions corresponding to these QTL are involved in the regulation of

  7. On the possible effect of round-the-world surface seismic waves in the dynamics of repeated shocks after strong earthquakes

    Science.gov (United States)

    Zotov, O. D.; Zavyalov, A. D.; Guglielmi, A. V.; Lavrov, I. P.

    2018-01-01

    Based on the observation data for hundreds of the main shocks and thousands of aftershocks, the existence of effect of round-the-world surface seismic waves is demonstrated (let us conditionally refer to them as a round-the-world seismic echo) and the manifestations of this effect in the dynamics of the repeated shocks of strong earthquakes are analyzed. At the same time, we by no means believe this effect has been fully proven. We only present a version of our own understanding of the physical causes of the observed phenomenon and analyze the regularities in its manifestation. The effect is that the surface waves excited in the Earth by the main shock make a full revolution around the Earth and excite a strong aftershock in the epicentral zone of the main shock. In our opinion, the physical nature of this phenomenon consists in the fact that the superposition leads to a concentration of wave energy when the convergent surface waves reach the epicentral zone (cumulative effect). The effect of the first seismic echo is most manifest. Thus, the present work supports our hypothesis of the activation of rock failure under the cumulative impact of an round-the-world seismic echo on the source area which is releasing ("cooling") after the main shock. The spatial regularities in the manifestations of this effect are established, and the independence of the probability of its occurrence on the main shock magnitude is revealed. The effect of a round-the-world seismic echo can be used to improve the reliability of the forecasts of strong aftershocks in determining the scenario for the seismic process developing in the epicentral zone of a strong earthquake that has taken place.

  8. Development of a Newtron-Krylov Iterative Method to Address Strong Non-Linear Feedback Effect in BWR Core Simulators

    International Nuclear Information System (INIS)

    Doddy Kastanya; Paul Turinsky

    2002-01-01

    A Newton-BICGSTAB solver has been developed to reduce the CPU execution time of BWR core simulators. The new solver treats the strong non-linearities in the problem explicitly using the Newton's method, replacing the traditionally used nested iterative approach. The Newton's method provides the solver with a higher-than-linear convergence rate, assuming that a good initial estimate of the unknowns is provided. Within each Newton iteration, an appropriately preconditioned BICGSTAB method is utilized for solving the linearized system of equations. Taking advantage of the higher convergence rate provided by the Newton's method and utilizing an efficient preconditioned BICGSTAB solver, we have developed a computationally efficient Newton-BICGSTAB solver to evaluate the three-dimensional, two-group neutron diffusion equations coupled with a two-phase flow model within a BWR core simulator. The robustness of the solver has been tested against numerous BWR core configurations and consistent results have been observed each time. The Newton-BICGSTAB solver provides an overall speedup of around 1.7 to the core simulator, with reference to the traditional approach. Isolating the solver portion of the core simulator, one can see that the new algorithm actually provides a speedup of around 1.9, of which 48% can be attributed to the BICGSTAB solver and the remaining 52% to Newton's method

  9. Comparing the epidermal growth factor interaction with four different cell lines: intriguing effects imply strong dependency of cellular context.

    Directory of Open Access Journals (Sweden)

    Hanna Björkelund

    Full Text Available The interaction of the epidermal growth factor (EGF with its receptor (EGFR is known to be complex, and the common over-expression of EGF receptor family members in a multitude of tumors makes it important to decipher this interaction and the following signaling pathways. We have investigated the affinity and kinetics of (125I-EGF binding to EGFR in four human tumor cell lines, each using four culturing conditions, in real time by use of LigandTracer®.Highly repeatable and precise measurements show that the overall apparent affinity of the (125I-EGF - EGFR interaction is greatly dependent on cell line at normal culturing conditions, ranging from K(D ≈ 200 pM on SKBR3 cells to K(D≈8 nM on A431 cells. The (125I-EGF - EGFR binding curves (irrespective of cell line have strong signs of multiple simultaneous interactions. Furthermore, for the cell lines A431 and SKOV3, gefitinib treatment increases the (125I-EGF - EGFR affinity, in particular when the cells are starved. The (125I-EGF - EGFR interaction on cell line U343 is sensitive to starvation while as on SKBR3 it is insensitive to gefitinib and starvation.The intriguing pattern of the binding characteristics proves that the cellular context is important when deciphering how EGF interacts with EGFR. From a general perspective, care is advisable when generalizing ligand-receptor interaction results across multiple cell-lines.

  10. Effects of strong earthquakes in variations of electrical and meteorological parameters of the near-surface atmosphere in Kamchatka region

    Science.gov (United States)

    Smirnov, S. E.; Mikhailova, G. A.; Mikhailov, Yu. M.; Kapustina, O. V.

    2017-09-01

    The diurnal variations in electrical (quasistatic electric field and electrical conductivity) and meteorological (temperature, pressure, relative humidity of the atmosphere, and wind speed) parameters, measured simultaneously before strong earthquakes in Kamchatka region (November 15, 2006, M = 8.3; January 13, 2007, M = 8.1; January 30, 2016, M = 7.2), are studied for the first time in detail. It is found that a successively anomalous increase in temperature, despite the negative regular trend in these winter months, was observed in the period of six-seven days before the occurrences of earthquakes. An anomalous temperature increase led to the formation of "winter thunderstorm" conditions in the near-surface atmosphere of Kamchatka region, which was manifested in the appearance of an anomalous, type 2 electrical signal, the amplification of and intensive variations in electrical conductivity, heavy precipitation (snow showers), high relative humidity of air, storm winds, and pressure changes. With the weak flow of natural heat radiation in this season, the observed dynamics of electric and meteorological processes can likely be explained by the appearance of an additional heat source of seismic nature.

  11. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber.

    Directory of Open Access Journals (Sweden)

    Ting-Ting Cao

    Full Text Available Strongly alkaline electrolyzed water (SAEW was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+ concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin.

  12. Effect of Strongly Alkaline Electrolyzed Water on Silk Degumming and the Physical Properties of the Fibroin Fiber.

    Science.gov (United States)

    Cao, Ting-Ting; Wang, Yuan-Jing; Zhang, Yu-Qing

    2013-01-01

    Strongly alkaline electrolyzed water (SAEW) was prepared by electrolysis of tap water in a laboratory-made water electrolyzer. The pH of stored SAEW was stable for more than one month. The hardness of the electrolyzed water was 30% lower and the Na(+) concentration was 18% higher than those of the tap water. Silkworm cocoon shells were boiled in pH 11.50 SAEW at a ratio of 1∶40∼80 (W/V) for 20 min and the sericin layers around the silk fibroin fibers were removed completely. The tensile properties and thermal decomposition temperature of a single filament of silk fibroin obtained by the SAEW method were almost the same as those for the fiber obtained by the neutral soap, and much higher than those for the fiber obtained by Na2CO3 degumming. The results demonstrate that SAEW is an environmentally friendly and pollution-free silk degumming agent that allows highly efficient, low cost recovery of sericin.

  13. Cost-effectiveness of the strong African American families-teen program: 1-year follow-up.

    Science.gov (United States)

    Ingels, Justin B; Corso, Phaedra S; Kogan, Steve M; Brody, Gene H

    2013-12-01

    Alcohol use poses a major threat to the health and well being of rural African American adolescents by negatively impacting academic performance, health, and safety. However, rigorous economic evaluations of prevention programs targeting this population are scarce. Cost-effectiveness analyses were conducted of SAAF-T relative to an attention-control intervention (ACI), as part of a randomized prevention trial. Outcomes of interest were the number of alcohol use and binge drinking episodes prevented, one year following the intervention. Incremental cost-effectiveness ratios (ICERs) and cost-effectiveness acceptability curves (CEACs) were used to determine the cost-effectiveness of SAAF-T compared to the ACI intervention. For the 473 participating youth completing baseline and follow-up assessments, the incremental per participant costs were $168, while the incremental per participant effects were 3.39 episodes of alcohol use prevented and 1.36 episodes of binge drinking prevented. Compared to the ACI intervention, the SAAF-T program cost $50 per reduction in an alcohol use episode and $123 per reduced episode of binge drinking. For the CEACs, at thresholds of $100 and $440, SAAF-T has at least a 90% probability of being cost-effective, relative to the ACI, for reductions in alcohol use and binge drinking episodes, respectively. The SAAF-T intervention provides a potentially cost-effective means for reducing the African American youths' alcohol use and binge drinking episodes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  14. The Effects of Chronic Nitrate Supplementation and the Use of Strong and Weak Antibacterial Agents on Plasma Nitrite Concentration and Exercise Blood Pressure.

    Science.gov (United States)

    McDonagh, S T J; Wylie, L J; Winyard, P G; Vanhatalo, A; Jones, A M

    2015-12-01

    Chlorhexidine-containing mouthwash (STRONG), which disturbs oral microflora, has been shown to diminish the rise in plasma nitrite concentration ([NO2-]) and attenuate the reduction in resting blood pressure (BP) typically seen after acute nitrate (NO3-) ingestion. We aimed to determine whether STRONG and weaker antiseptic agents attenuate the physiological effects of chronic NO3- supplementation using beetroot juice (BR). 12 healthy volunteers mouth-rinsed with STRONG, non-chlorhexidine mouthwash (WEAK) and deionised water (CON) 3 times a day, and ingested 70 mL BR (6.2 mmol NO3-), twice a day, for 6 days. BP (at rest and during 10 min of treadmill walking) and plasma and salivary [NO3-] and [NO2-] were measured prior to and on day 6 of supplementation. The change in salivary [NO3-] 4 h post final ingestion was higher (P0.05). However, during treadmill walking, the increase in systolic and mean arterial BP was higher 4 h after the final nitrate bolus in STRONG compared with CON (P<0.05) but not WEAK. The results indicate that both strong and weak antibacterial agents suppress the rise in plasma [NO2-] observed following the consumption of a high NO3- diet and the former can influence the BP response during low-intensity exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  15. A model for the training effects in swimming demonstrates a strong relationship between parasympathetic activity, performance and index of fatigue.

    Directory of Open Access Journals (Sweden)

    Sébastien Chalencon

    Full Text Available Competitive swimming as a physical activity results in changes to the activity level of the autonomic nervous system (ANS. However, the precise relationship between ANS activity, fatigue and sports performance remains contentious. To address this problem and build a model to support a consistent relationship, data were gathered from national and regional swimmers during two 30 consecutive-week training periods. Nocturnal ANS activity was measured weekly and quantified through wavelet transform analysis of the recorded heart rate variability. Performance was then measured through a subsequent morning 400 meters freestyle time-trial. A model was proposed where indices of fatigue were computed using Banister's two antagonistic component model of fatigue and adaptation applied to both the ANS activity and the performance. This demonstrated that a logarithmic relationship existed between performance and ANS activity for each subject. There was a high degree of model fit between the measured and calculated performance (R(2=0.84±0.14,p<0.01 and the measured and calculated High Frequency (HF power of the ANS activity (R(2=0.79±0.07, p<0.01. During the taper periods, improvements in measured performance and measured HF were strongly related. In the model, variations in performance were related to significant reductions in the level of 'Negative Influences' rather than increases in 'Positive Influences'. Furthermore, the delay needed to return to the initial performance level was highly correlated to the delay required to return to the initial HF power level (p<0.01. The delay required to reach peak performance was highly correlated to the delay required to reach the maximal level of HF power (p=0.02. Building the ANS/performance identity of a subject, including the time to peak HF, may help predict the maximal performance that could be obtained at a given time.

  16. Strong Erosion-Driven Nongravitational Effects in Orbital Motions of the Kreutz Sungrazing System’s Dwarf Comets

    Science.gov (United States)

    Sekanina, Zdenek; Kracht, Rainer

    2015-03-01

    We investigate the relationships among the angular orbital elements—the longitude of the ascending node Ω, the inclination i, and the argument of perihelion ω—of the Kreutz system’s faint, dwarf sungrazers observed only with the Solar and Heliospheric Observatory/STEREO coronagraphs; their published orbits were derived using a parabolic, purely gravitational approximation. In a plot of i against Ω the bright Kreutz sungrazers (such as C/1843 D1, C/1882 R1, C/1963 R1, etc.) fit a curve of fixed apsidal orientation, whereas the dwarf members are distributed along a curve that makes with the apsidal curve an angle of 15°. The dwarf sungrazers’ perihelion longitude is statistically invariable, but their perihelion latitude increases systematically with Ω. We find that this trend can be explained by a strong erosion-driven nongravitational acceleration normal to the orbit plane, confirmed for several test dwarf Kreutz sungrazers by orbital solutions with nongravitational terms incorporated directly in the equations of motion on a condition of fixed apsidal orientation. Proceeding in three steps, we first apply Marsden et al.'s standard formalism, solving for the normal acceleration only, and eventually relax additional constraints on the nongravitational law and the acceleration’s radial and transverse components. The resulting nongravitational accelerations on the dwarf sungrazers exceed the maximum for cataloged comets in nearly parabolic orbits by up to three orders of magnitude, topping in exceptional cases the Sun’s gravitational acceleration! A mass-loss model suggests that the dwarf sungrazers’ nuclei fragment copiously and their dimensions diminish rapidly near the Sun, implying the objects’ imminent demise shortly before they reach perihelion.

  17. Strong WW Interaction at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Pelaez, Jose R

    1998-12-14

    We present a brief pedagogical introduction to the Effective Electroweak Chiral Lagrangians, which provide a model independent description of the WW interactions in the strong regime. When it is complemented with some unitarization or a dispersive approach, this formalism allows the study of the general strong scenario expected at the LHC, including resonances.

  18. Effects of strong inter-hydrogen bond dynamical couplings in the polarized IR spectra of adipic acid crystals

    Energy Technology Data Exchange (ETDEWEB)

    Flakus, Henryk T., E-mail: flakus@ich.us.edu.pl [Institute of Chemistry, University of Silesia, 9 Szkolna Street, Pl-40-006 Katowice (Poland); Tyl, Aleksandra; Jablonska, Magdalena [Institute of Chemistry, University of Silesia, 9 Szkolna Street, Pl-40-006 Katowice (Poland)

    2009-10-16

    This paper presents the results of the re-investigation of polarized IR spectra of adipic acid and of its d{sub 2}, d{sub 8} and d{sub 10} deuterium derivative crystals. The spectra were measured at 77 K by a transmission method using polarized light for two different crystalline faces. Theoretical analysis concerned linear dichroic effects and H/D isotopic effects observed in the spectra of the hydrogen and deuterium bonds in adipic acid crystals at the frequency ranges of the {nu}{sub O-H} and the {nu}{sub O-D} bands. The two-branch fine structure pattern of the {nu}{sub O-H} and {nu}{sub O-D} bands and the basic linear dichroic effects characterizing them were ascribed to the vibronic mechanism of vibrational dipole selection rule breaking for IR transitions in centrosymmetric hydrogen bond dimers. It was proved that for isotopically diluted crystalline samples of adipic acid, a non-random distribution of protons and deuterons occurs in the dimers (H/D isotopic 'self-organization' effect). This effect results from the dynamical co-operative interactions involving the dimeric hydrogen bonds.

  19. Effects of strong inter-hydrogen bond dynamical couplings in the polarized IR spectra of adipic acid crystals

    Science.gov (United States)

    Flakus, Henryk T.; Tyl, Aleksandra; Jablońska, Magdalena

    2009-10-01

    This paper presents the results of the re-investigation of polarized IR spectra of adipic acid and of its d2, d8 and d10 deuterium derivative crystals. The spectra were measured at 77 K by a transmission method using polarized light for two different crystalline faces. Theoretical analysis concerned linear dichroic effects and H/D isotopic effects observed in the spectra of the hydrogen and deuterium bonds in adipic acid crystals at the frequency ranges of the νO-H and the νO-D bands. The two-branch fine structure pattern of the νO-H and νO-D bands and the basic linear dichroic effects characterizing them were ascribed to the vibronic mechanism of vibrational dipole selection rule breaking for IR transitions in centrosymmetric hydrogen bond dimers. It was proved that for isotopically diluted crystalline samples of adipic acid, a non-random distribution of protons and deuterons occurs in the dimers (H/D isotopic " self-organization" effect). This effect results from the dynamical co-operative interactions involving the dimeric hydrogen bonds.

  20. Association of yield-related traits in founder genotypes and derivatives of common wheat (Triticum aestivum L.

    Directory of Open Access Journals (Sweden)

    Jie Guo

    2018-02-01

    Full Text Available Abstract Background Yield improvement is an ever-important objective of wheat breeding. Studying and understanding the phenotypes and genotypes of yield-related traits has potential for genetic improvement of crops. Results The genotypes of 215 wheat cultivars including 11 founder parents and 106 derivatives were analyzed by the 9 K wheat SNP iSelect assay. A total of 4138 polymorphic single nucleotide polymorphism (SNP loci were detected on 21 chromosomes, of which 3792 were mapped to single chromosome locations. All genotypes were phenotyped for six yield-related traits including plant height (PH, spike length (SL, spikelet number per spike (SNPS, kernel number per spike (KNPS, kernel weight per spike (KWPS, and thousand kernel weight (TKW in six irrigated environments. Genome-wide association analysis detected 117 significant associations of 76 SNPs on 15 chromosomes with phenotypic explanation rates (R 2 ranging from 2.03 to 12.76%. In comparing allelic variation between founder parents and their derivatives (106 and other cultivars (98 using the 76 associated SNPs, we found that the region 116.0–133.2 cM on chromosome 5A in founder parents and derivatives carried alleles positively influencing kernel weight per spike (KWPS, rarely found in other cultivars. Conclusion The identified favorable alleles could mark important chromosome regions in derivatives that were inherited from founder parents. Our results unravel the genetic of yield in founder genotypes, and provide tools for marker-assisted selection for yield improvement.

  1. Birth of scientific surgery. John Hunter versus Joseph Lister as the father or founder of scientific surgery.

    Science.gov (United States)

    Toledo-Pereyra, Luis H

    2010-02-01

    John Hunter (1728-1793) has frequently been considered the "Father or Founder of Scientific Surgery". His inscription at Westminster Abbey presents him as "a gifted interpreter of the Divine Power and wisdom at work in the laws of organic life and the Founder of Scientific Surgery." I take issue with Hunter being considered the father or founder of scientific surgery and propose Joseph Lister (1827-1912) as the one who should receive this consideration. Hunter was a skilled surgeon, an inquisitive innovator, keen observer, great naturalist, and astute thinker, who made no surgical discoveries of any transcendence to the discipline. His scientific observations were not in the field of surgery. Therefore, he should not be considered the "Father or Founder of Scientific Surgery." On the contrary, Lister became a revolutionary scientific innovator by explaining the pervasive role of microorganisms in surgical wounds. His work directly affected surgery and its role in medicine. Lister, therefore, should be considered the "Father or Founder of Scientific Surgery."

  2. The SNARC effect in the processing of second-language number words: further evidence for strong lexico-semantic connections.

    Science.gov (United States)

    De Brauwer, Jolien; Duyck, Wouter; Brysbaert, Marc

    2008-03-01

    We present new evidence that word translation involves semantic mediation. It has been shown that participants react faster to small numbers with their left hand and to large numbers with their right hand. This SNARC (spatial-numerical association of response codes) effect is due to the fact that in Western cultures the semantic number line is oriented from left (small) to right (large). We obtained a SNARC effect when participants had to indicate the parity of second-language (L2) number words, but not when they had to indicate whether L2 number words contained a particular sound. Crucially, the SNARC effect was also obtained in a translation verification task, indicating that this task involved the activation of number magnitude.

  3. Concentration and timing of application reveal strong fungistatic effect of tebuconazole in a Daphnia-microparasitic yeast model.

    Science.gov (United States)

    Cuco, Ana P; Santos, Joana I; Abrantes, Nelson; Gonçalves, Fernando; Wolinska, Justyna; Castro, Bruno B

    2017-12-01

    Given the importance of pollutant effects on host-parasite relationships and disease spread, the main goal of this study was to assess the influence of different exposure scenarios for the fungicide tebuconazole (concentration×timing of application) on a Daphnia-microparasitic yeast experimental system. Previous results had demonstrated that tebuconazole is able to suppress Metschnikowia bicuspidata infection at ecologically-relevant concentrations; here, we aimed to obtain an understanding of the mechanism underlying the anti-parasitic (fungicidal or fungistatic) action of tebuconazole. We exposed the Daphnia-yeast system to four nominal tebuconazole concentrations at four timings of application (according to the predicted stage of parasite development), replicated on two Daphnia genotypes, in a fully crossed experiment. An "all-or-nothing" effect was observed, with tebuconazole completely suppressing infection from 13.5μgl -1 upwards, independent of the timing of tebuconazole application. A follow-up experiment confirmed that the suppression of infection occurred within a narrow range of tebuconazole concentrations (3.65-13.5μgl -1 ), although a later application of the fungicide had to be compensated for by a slight increase in concentration to elicit the same anti-parasitic effect. The mechanism behind this anti-parasitic effect seems to be the inhibition of M. bicuspidata sporulation, since tebuconazole was effective in preventing ascospore production even when applied at a later time. However, this fungicide also seemed to affect the vegetative growth of the yeast, as demonstrated by the enhanced negative effect of the parasite (increasing mortality in one of the host genotypes) at a later time of application of tebuconazole, when no signs of infection were observed. Fungicide contamination can thus affect the severity and spread of disease in natural populations, as well as the inherent co-evolutionary dynamics in host-parasite systems. Copyright © 2017

  4. Aharonov-Casher and spin Hall effects in mesoscopic ring structures with strong spin-orbit interaction

    Czech Academy of Sciences Publication Activity Database

    Borunda, M.F.; Liu, X.; Kovalev, A.A.; Liu, X.-J.; Jungwirth, Tomáš; Sinova, J.

    2008-01-01

    Roč. 78, č. 24 (2008), 245315/1-245315/9 ISSN 1098-0121 R&D Projects: GA MŠk LC510; GA AV ČR KAN400100652; GA ČR GEFON/06/E002 EU Projects: European Commission(XE) 015728 - NANOSPIN Institutional research plan: CEZ:AV0Z10100521 Keywords : Aharonov-Casher effect * spin Hall effect * spin-orbit interaction Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.322, year: 2008

  5. Selective accumulation and strong photodynamic effects of a new photosensitizer, ATX-S10.Na (II), in experimental malignant glioma.

    Science.gov (United States)

    Yamamoto, Junkoh; Hirano, Toru; Li, Shaoyi; Koide, Masayo; Kohno, Eiji; Inenaga, Chikanori; Tokuyama, Tsutomu; Yokota, Naoki; Yamamoto, Seiji; Terakawa, Susumu; Namba, Hiroki

    2005-11-01

    We investigated the feasibility of a novel photosensitizer, ATX-S10.Na (II), in photodynamic therapy (PDT) for glioma. First, PDT was performed in various brain tumor cell lines in vitro. Cytotoxicity depended upon both drug concentration and laser energy and the 50% inhibitory concentration ranged from 3.5 to 20 microg/ml. Next, PDT was performed in the subcutaneous and intracranial 9L tumor models in Fischer rats using ATX-S10.Na (II) and light from a 670-nm diode laser delivered by intratumoral insertion of an optical fiber. The effect of PDT on brain tumors was evaluated using magnetic resonance imaging. Sequential changes of the ATX-S10.Na (II) concentrations were also measured quantitatively by fluorospectrometry up to 12 h after intravenous administration in rats with intracranial and subcutaneous tumors. The concentration of ATX-S10.Na (II) in the brain tumor reached a maximum at 2 h after administration and the tumor/normal brain concentration ratio was as high as 131 at 8 h. Intratumoral PDT for intracranial tumors irradiated at this timing showed an obvious anti-tumor effect without severe side effects. The present study demonstrated the highly selective accumulation of ATX-S10.Na (II) in tumor tissue and its potent photodynamic effect in an experimental malignant glioma model.

  6. Strong Geometrical Effects in Submillimeter Selective Area Growth and Light Extraction of GaN Light Emitting Diodes on Sapphire

    Science.gov (United States)

    Tanaka, Atsunori; Chen, Renjie; Jungjohann, Katherine L.; Dayeh, Shadi A.

    2015-11-01

    Advanced semiconductor devices often utilize structural and geometrical effects to tailor their characteristics and improve their performance. We report here detailed understanding of such geometrical effects in the epitaxial selective area growth of GaN on sapphire substrates and utilize them to enhance light extraction from GaN light emitting diodes. Systematic size and spacing effects were performed side-by-side on a single 2” sapphire substrate to minimize experimental sampling errors for a set of 144 pattern arrays with circular mask opening windows in SiO2. We show that the mask opening diameter leads to as much as 4 times increase in the thickness of the grown layers for 20 μm spacings and that spacing effects can lead to as much as 3 times increase in thickness for a 350 μm dot diameter. We observed that the facet evolution in comparison with extracted Ga adatom diffusion lengths directly influences the vertical and lateral overgrowth rates and can be controlled with pattern geometry. Such control over the facet development led to 2.5 times stronger electroluminescence characteristics from well-faceted GaN/InGaN multiple quantum well LEDs compared to non-faceted structures.

  7. The ecological effects of water level fluctuation and phosphate enrichment in mesotrophic peatlands are strongly mediated by soil chemistry

    NARCIS (Netherlands)

    Mettrop, I.S.; Rutte, M.D.; Kooijman, A.M.; Lamers, L.P.M.

    2015-01-01

    Since the re-establishment of a more natural water regime is considered by water management in wetlands with artificially stable water levels, the biogeochemical and ecological effects of water level fluctuation with different nutrient loads should be investigated. This is particularly important for

  8. [Max Josef von Pettenkofer--founder of modern hygiene (1818-1901)].

    Science.gov (United States)

    Paunović, Katarina; Maksimović, Milos; Davidović, Dragana; Milenković, Sanja; Slepcević, Vesna

    2005-01-01

    Max Josef von Pettenkofer was one of the leading personalities in the world of medicine in the 19th century. He was the founder of the modern science of hygiene. In his experimental work, he was involved in the research of problems dealing with the relationship between human beings and the environment, including such topics as soil and air pollution, water supply, sewage water management, room ventilation and heating, as well as the function of clothing and the cleanliness of homes and streets. Pettenkofer also studied the onset, the course, and the consequences of infectious diseases, such as cholera and typhus. He realised the great economic value of public health and emphasised that personal preventive measures should be supplemented with the improvement of factors in communal and work environments. His efforts lead to hygiene becoming a part of medical studies in 1865. The Institute for Hygiene at the School of Medicine in Munich was established in 1879. It was constructed according to his drawings and was considered to be the most modern institute for hygiene in the world. Since hygiene was a subject on the school curriculum in the German Empire in 1882, Pettenkofer became the Chairman of Hygiene in Berlin in 1885. Research institutions established by Pettenkofer and the fact that many of his students became professors of hygiene speak about the importance of his work. One of his students was professor Milan Jovanović Batut, founder of the Institute for Hygiene at the School of Medicine in Belgrade.

  9. Haplotype variation in founders of the Mauremys annamensis population kept in European Zoos

    Directory of Open Access Journals (Sweden)

    Barbora Somerova

    2015-06-01

    Full Text Available The critically endangered Annam leaf turtle Mauremys annamensis faces extinction in nature. Because of that, the conservation value of the population kept in European zoos becomes substantial for reintroduction programmes. We sampled 39 specimens of M. annamensis from European zoos and other collections (mainly founders, imports and putatively unrelated individuals, and also four specimens of Mauremys mutica for comparison. In each animal, we sequenced 817 bp of the mitochondrial ND4 gene and 940 bp of the nuclear R35 intron that were used as phylogenetic markers for Mauremys mutica-annamensis group by previous authors. The sequences of the R35 intron, which are characteristic for M. annamensis and which clearly differ from those characteristic for M. mutica and/or other Mauremys species, were mutually shared by all of the examined M. annamensis. They also possessed mitochondrial haplotypes belonging to the annamensis subclades I and II, distinctness of which was clearly confirmed by phylogenetic analyses. Thus, both nuclear and mitochondrial markers agreed in the unequivocal assignment of the examined individuals to M. annamensis. Although no obvious hybrids were detected within the founders of the captive population, further careful genetic evaluation using genom-wide markers is required to unequivocally confirm this result.

  10. Mutation analysis in Norwegian families with hereditary hemorrhagic telangiectasia: founder mutations in ACVRL1.

    Science.gov (United States)

    Heimdal, K; Dalhus, B; Rødningen, O K; Kroken, M; Eiklid, K; Dheyauldeen, S; Røysland, T; Andersen, R; Kulseth, M A

    2016-02-01

    Hereditary hemorrhagic telangiectasia (HHT, Osler-Weber-Rendu disease) is an autosomal dominant inherited disease defined by the presence of epistaxis and mucocutaneous telangiectasias and arteriovenous malformations (AVMs) in internal organs. In most families (~85%), HHT is caused by mutations in the ENG (HHT1) or the ACVRL1 (HHT2) genes. Here, we report the results of genetic testing of 113 Norwegian families with suspected or definite HHT. Variants in ENG and ACVRL1 were found in 105 families (42 ENG, 63 ACVRL1), including six novel variants of uncertain pathogenic significance. Mutation types were similar to previous reports with more missense variants in ACVRL1 and more nonsense, frameshift and splice-site mutations in ENG. Thirty-two variants were novel in this study. The preponderance of ACVRL1 mutations was due to founder mutations, specifically, c.830C>A (p.Thr277Lys), which was found in 24 families from the same geographical area of Norway. We discuss the importance of founder mutations and present a thorough evaluation of missense and splice-site variants. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  11. <strong>Relative Biological Effect of Antiprotonsstrong>> strong>

    DEFF Research Database (Denmark)

    Bassler, Niels; Holzscheiter, Michael

    purpose/objective The AD-4/ACE collaboration has recently performed experiments to directly measure the RBE of antiprotons. Antiprotons have very similar stopping power compared to protons, but when they come to rest, antiprotons will annihilate on a target nucleus and thereby release almost 2 Ge......V of energy. About 30 MeV of this energy is deposited in the vicinity of the Bragg-peak, thereby significantly enhancing it. It is furthermore expected that this additional energy is deposited by radiation which carries a high-LET component. This will have a significant influence on the radiobiological...... nuclear research facility CERN. A beam of 126 MeV antiprotons, corresponding to about 12 cm range in water, was spread out to a SOBP with a width of 1 cm. Dosimetry experiments were carried out with ionization chambers, alanine pellets and radiochromic film, and the results were used for benchmarking...

  12. Pesticide interactions with soil affected by olive mill wastewater (OMW): how strong and long-lasting is the OMW effect?

    Science.gov (United States)

    Keren, Yonatan; Borisover, Mikhail; Schaumann, Gabriele E.; Diehl, Dörte; Tamimi, Nisreen; Bukhanovsky, Nadezhda

    2017-04-01

    Sorption interactions with soils are well known to control the environmental fate of multiple organic compounds including pesticides. Pesticide-soil interactions may be affected by organic amendments or organic matter (OM)-containing wastewater brought to the field. Specifically, land spreading of olive mill wastewater (OMW), occurring intentionally or not, may also influence pesticide-soil interactions. The effects of the OMW disposed in the field on soil properties, including their ability to interact with pesticides, become of great interest due to the increasing demand for olive oil and a constant growth of world oil production. This paper summarizes some recent findings related to the effect of prior OMW land application on the ability of soils to interact with the organic compounds including pesticides, diuron and simazine. The major findings are as following: (1) bringing OMW to the field increases the potential of soils to sorb non-ionized pesticides; (2) this sorption increase may not be related solely to the increase in soil organic carbon content but it can reflect also the changes in the soil sorption mechanisms; (3) increased pesticide interactions with OMW-affected soils may become irreversible, due, assumedly, to the swelling of some components of the OMW-treated soil; (4) enhanced pesticide-soil interactions mitigate with the time passed after the OMW application, however, in the case of diuron, the remaining effect could be envisioned at least 600 days after the normal OMW application; (5) the enhancement effect of OMW application on soil sorption may increase with soil depth, in the 0-10 cm interval; (6) at higher pesticide (diuron) concentrations, larger extents of sorption enhancement, following the prior OMW-soil interactions, may be expected; (7) disposal of OMW in the field may be seasonal-dependent, and, in the case studied, it led to more distinct impacts on sorption when carried out in spring and winter, as compared with summer. It appears

  13. Testing strong interaction theories

    International Nuclear Information System (INIS)

    Ellis, J.

    1979-01-01

    The author discusses possible tests of the current theories of the strong interaction, in particular, quantum chromodynamics. High energy e + e - interactions should provide an excellent means of studying the strong force. (W.D.L.)

  14. Strong influence of long-distance edge effect on herb-layer vegetation in forest fragments in an agricultural landscape

    Czech Academy of Sciences Publication Activity Database

    Hofmeister, J.; Hošek, J.; Brabec, Marek; Hédl, Radim; Modrý, M.

    2013-01-01

    Roč. 15, č. 6 (2013), s. 293-303 ISSN 1433-8319 Grant - others:GA MŽP(CZ) SM/6/69/05; GA MŽP(CZ) SP/2D3/139/07 Institutional support: RVO:67985807 ; RVO:67985939 Keywords : ancient forest * edge effect * habitat fragmentation * light condition * soil nutrients * species richness Subject RIV: BB - Applied Statistics, Operational Research; EH - Ecology, Behaviour (BU-J) Impact factor: 3.324, year: 2013

  15. Concentration and timing of application reveal strong fungistatic effect of tebuconazole in a Daphnia-microparasitic yeast model

    OpenAIRE

    Cuco, A. P.; Santos, J. I.; Abrantes, N.; Gonçalves, F.; Castro, Bruno B.

    2017-01-01

    Given the importance of pollutant effects on host-parasite relationships and disease spread, the main goal of this study was to assess the influence of different exposure scenarios for the fungicide tebuconazole (concentration × timing of application) on a Daphnia-microparasitic yeast experimental system. Previous results had demonstrated that tebuconazole is able to suppress Metschnikowia bicuspidata infection at ecologically-relevant concentrations; here, we aimed to obtain an understanding...

  16. Strong positive effects of termites on savanna bird abundance and diversity are amplified by large herbivore exclusion

    OpenAIRE

    Moe, Stein R.; Eldegard, Katrine; Rannestad, Ole Tobias; Okullo, Paul; Lindtjørn, Ommund; Støen, Ole Gunnar; Dale, Svein

    2017-01-01

    Abstract Vast areas of the African savanna landscapes are characterized by tree‐covered Macrotermes termite mounds embedded within a relatively open savanna matrix. In concert with termites, large herbivores are important determinants of savanna woody vegetation cover. The relative cover of woody species has considerable effects on savanna function. Despite the potentially important ecological relationships between termite mounds, woody plants, large herbivores, and birds, these associations ...

  17. Genetic consequences of a century of protection: serial founder events and survival of the little spotted kiwi (Apteryx owenii).

    Science.gov (United States)

    Ramstad, Kristina M; Colbourne, Rogan M; Robertson, Hugh A; Allendorf, Fred W; Daugherty, Charles H

    2013-07-07

    We present the outcome of a century of post-bottleneck isolation of a long-lived species, the little spotted kiwi (Apteryx owenii, LSK) and demonstrate that profound genetic consequences can result from protecting few individuals in isolation. LSK were saved from extinction by translocation of five birds from South Island, New Zealand to Kapiti Island 100 years ago. The Kapiti population now numbers some 1200 birds and provides founders for new populations. We used 15 microsatellite loci to compare genetic variation among Kapiti LSK and the populations of Red Mercury, Tiritiri Matangi and Long Islands that were founded with birds from Kapiti. Two LSK native to D'Urville Island were also placed on Long Island. We found extremely low genetic variation and signatures of acute and recent genetic bottleneck effects in all four populations, indicating that LSK have survived multiple genetic bottlenecks. The Long Island population appears to have arisen from a single mating pair from Kapiti, suggesting there is no genetic contribution from D'Urville birds among extant LSK. The Ne/NC ratio of Kapiti Island LSK (0.03) is exceptionally low for terrestrial vertebrates and suggests that genetic diversity might still be eroding in this population, despite its large census size.

  18. Genetic variation of the Turnip mosaic virus population of Vietnam: a case study of founder, regional and local influences.

    Science.gov (United States)

    Nguyen, Huy Duc; Tran, Hoa Thi Nhu; Ohshima, Kazusato

    2013-01-01

    Turnip mosaic virus (TuMV) is one of the most important viruses infecting a wide range of plant species, primarily from the family Brassicaceae. Thirty TuMV isolates were collected from Brassica and Raphanus plants in Vietnam during 2006-2008. Host reaction studies showed that many of the isolates belonged to Brassica/Raphanus (BR) host-infecting type. Sequence-based phylogenetic and population genetic analyses were made of the complete polyprotein gene sequences, and of four non-recombinogenic regions of those sequences (i.e. genes of the helper-component proteinase protein, protein 3, nuclear inclusion b protein and coat protein). These were used to assess the subpopulation differentiation and divergence between Vietnamese TuMV populations and those of nearby Asian countries. Nine inter- and intralineage recombination type patterns were identified in the genomes of the Vietnamese isolates, of which seven were novel. All the Vietnamese non-recombinant isolates fell into the world-B group of TuMV and clustered with Chinese isolates. The estimates of genetic differentiation and gene flow reveal that the TuMV populations of Vietnam, China and Japan are genetically linked but have clear local founder effects. This, the first population genetic study of a TuMV population in Southeast Asia, indicates the importance of such studies for providing the scientific basis of control strategies. Copyright © 2012 Elsevier B.V. All rights reserved.

  19. Strong room-temperature negative transconductance in an axial Si/Ge hetero-nanowire tunneling field-effect transistor

    Science.gov (United States)

    Zhang, Peng; Le, Son T.; Hou, Xiaoxiao; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, S. T.

    2014-08-01

    We report on room-temperature negative transconductance (NTC) in axial Si/Ge hetero-nanowire tunneling field-effect transistors. The NTC produces a current peak-to-valley ratio >45, a high value for a Si-based device. We characterize the NTC over a range of gate VG and drain VD voltages, finding that NTC persists down to VD = -50 mV. The physical mechanism responsible for the NTC is the VG-induced depletion in the p-Ge section that eventually reduces the maximum electric field that triggers the tunneling ID, as confirmed via three-dimensional (3D) technology computer-aided design simulations.

  20. Strong Rashba-Edelstein Effect-Induced Spin–Orbit Torques in Monolayer Transition Metal Dichalcogenide/Ferromagnet Bilayers

    KAUST Repository

    Shao, Qiming

    2016-11-18

    The electronic and optoelectronic properties of two-dimensional materials have been extensively explored in graphene and layered transition metal dichalcogenides (TMDs). Spintronics in these two-dimensional materials could provide novel opportunities for future electronics, for example, efficient generation of spin current, which should enable the efficient manipulation of magnetic elements. So far, the quantitative determination of charge current-induced spin current and spin-orbit torques (SOTs) on the magnetic layer adjacent to two-dimensional materials is still lacking. Here, we report a large SOT generated by current-induced spin accumulation through the Rashba-Edelstein effect in the composites of monolayer TMD (MoS or WSe)/CoFeB bilayer. The effective spin conductivity corresponding to the SOT turns out to be almost temperature-independent. Our results suggest that the charge-spin conversion in the chemical vapor deposition-grown large-scale monolayer TMDs could potentially lead to high energy efficiency for magnetization reversal and convenient device integration for future spintronics based on two-dimensional materials.

  1. Roles of the quadrupole interaction and of the quadratic stark effect in spectral lines from plasmas interacting with a strong quasimonochromatic electric field

    Czech Academy of Sciences Publication Activity Database

    Sauvan, P.; Dalimier, E.; Riconda, C.; Oks, E.; Renner, Oldřich; Weber, S.

    2010-01-01

    Roč. 1, č. 2 (2010), s. 123-128 ISSN 2229-3159 R&D Projects: GA MŠk(CZ) LC528 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-plasma interaction * PIC plasma model ing * strong quasimonochromatic electric fields * x-ray line broadening * stark effect * floquet theory Subject RIV: BH - Optics, Masers, Lasers http://www.auburn.edu/academic/cosam/departments/physics/iramp/1_2/sauvan_et_al.pdf

  2. CO J = 6-5 IN Arp 220: STRONG EFFECTS OF DUST ON HIGH-J CO LINES

    International Nuclear Information System (INIS)

    Papadopoulos, Padeli P.; Isaak, Kate; Van der Werf, Paul

    2010-01-01

    We report new single dish CO J = 6-5 line observations for the archetypal Ultra Luminous Infrared Galaxy (ULIRG) Arp 220 with the James Clerk Maxwell Telescope atop Mauna Kea in Hawaii. The J = 6-5 line is found to be faint, with brightness temperature ratios (6-5)/(1-0), (6-5)/(3-2) of R 65/10 = 0.080 ± 0.017 and R 65/32 = 0.082 ± 0.019, suggesting very low excitation conditions that cannot be reconciled with the warm and very dense molecular gas present in one of the most extreme starbursts in the local universe. We find that an optically thick dust continuum, with τ(ν ∼> 350 GHz) ∼> 1 for the bulk of the warm dust and gas in Arp 220, submerges this line to an almost black body curve, reducing its flux, and affecting its CO spectral line energy distribution at high frequencies. This also resolves the C + line deficiency in this object, first observed by Infrared Space Observatory: the near absence of that line is a dust optical depth effect, not a dense photodissociation region phenomenon. Finally, we briefly comment on the possibility of such extreme interstellar medium (ISM) states in other ULIRGs in the distant universe, and their consequences for the diagnostic utility of high frequency molecular and atomic ISM lines in such systems. In the case of Arp 220, we anticipate that the now spaceborne Herschel Space Observatory will find faint high-J CO lines at ν ∼> 690 GHz that would appear as sub-thermally excited with respect to the low-J ones as a result of the effects of dust absorption.

  3. Strong positive effects of termites on savanna bird abundance and diversity are amplified by large herbivore exclusion.

    Science.gov (United States)

    Moe, Stein R; Eldegard, Katrine; Rannestad, Ole Tobias; Okullo, Paul; Lindtjørn, Ommund; Støen, Ole Gunnar; Dale, Svein

    2017-12-01

    Vast areas of the African savanna landscapes are characterized by tree-covered Macrotermes termite mounds embedded within a relatively open savanna matrix. In concert with termites, large herbivores are important determinants of savanna woody vegetation cover. The relative cover of woody species has considerable effects on savanna function. Despite the potentially important ecological relationships between termite mounds, woody plants, large herbivores, and birds, these associations have previously received surprisingly little attention. We experimentally studied the effects of termites and large herbivores on the avian community in Lake Mburo National Park, Uganda, where woody vegetation is essentially limited to termite mounds. Our experiment comprised of four treatments in nine replicates; unfenced termite mounds, fenced mounds (excluding large mammals), unfenced adjacent savanna, and fenced savanna. We recorded species identity, abundance, and behavior of all birds observed on these plots over a two-month period, from late dry until wet season. Birds used termite mounds almost exclusively, with only 3.5% of observations occurring in the treeless intermound savanna matrix. Mean abundance and species richness of birds doubled on fenced (large herbivores excluded) compared to unfenced mounds. Feeding behavior increased when large mammals were excluded from mounds, both in absolute number of observed individuals, and relative to other behaviors. This study documents the fundamental positive impact of Macrotermes termites on bird abundance and diversity in an African savanna. Birds play crucial functional roles in savanna ecosystems, for example, by dispersing fruits or regulating herbivorous insect populations. Thus, the role of birds in savanna dynamics depends on the distribution and abundance of termite mounds.

  4. Survey of strong motion earthquake effects on thermal power plants in California with emphasis on piping systems. Volume 1, Main report

    International Nuclear Information System (INIS)

    Stevenson, J.D.

    1995-11-01

    Since 1982, there has been a major effort expended to evaluate the susceptibility of nuclear Power plant equipment to failure and significant damage during seismic events. This was done by making use of data on the performance of electrical and mechanical equipment in conventional power plants and other similar industrial facilities during strong motion earthquakes. This report is intended as an extension of the seismic experience data collection effort and a compilation of experience data specific to power plant piping and supports designed and constructed US power piping code requirements which have experienced strong motion earthquakes. Eight damaging (Richter Magnitude 7.7 to 5.5) California earthquakes and their effects on 8 power generating facilities in use natural gas and California were reviewed. All of these facilities were visited and evaluated. Seven fossel-fueled (dual use natural gas and oil) and one nuclear fueled plants consisting of a total of 36 individual boiler or reactor units were investigated. Peak horizontal ground accelerations that either had been recorded on site at these facilities or were considered applicable to these power plants on the basis of nearby recordings ranged between 0.20g and 0.5lg with strong motion durations which varied from 3.5 to 15 seconds. Most US nuclear power plants are designed for a safe shutdown earthquake peak ground acceleration equal to 0.20g or less with strong motion durations which vary from 10 to 15 seconds

  5. Propranolol–induced Impairment of Contextual Fear Memory Reconsolidation in Rats: A Similar Effect on Weak and Strong Recent and Remote Memories

    Directory of Open Access Journals (Sweden)

    Fatemeh Taherian

    2014-07-01

    Full Text Available Introduction: Previous studies have demonstrated that the &beta-adrenergic receptor antagonist propranolol impairs fear memory reconsolidation in experimental animals. There are experimental parameters such as the age and the strength of memory that can interact with pharmacological manipulations of memory reconsolidation. In this study, we investigated the ability of the age and the strength of memory to influence the disrupting effects of propranolol on fear memory reconsolidation in rats. Methods: The rats were trained in a contextual fear conditioning using two (weak training or five (strong training footshocks (1mA. Propranolol (10mg/kg injection was immediately followed retrieval of either a one-day recent (weak or strong or 36-day remote (weak or strong contextual fear memories. Results: We found that propranolol induced a long-lasting impairment of subsequent expression of recent and remote memories with either weak or strong strength. We also found no memory recovery after a weak reminder shock. Furthermore, no significant differences were found on the amount of memory deficit induced by propranolol among memories with different age and strength. Discussion: Our data suggest that the efficacy of propranolol in impairing fear memory reconsolidation is not limited to the age or strength of the memory.

  6. Designer thermal switches: the effect of the contact material on instantaneous thermoelectric transport through a strongly interacting quantum dot

    Science.gov (United States)

    Goker, A.; Gedik, E.

    2013-09-01

    We investigate the effect of contact material on the instantaneous thermoelectric response of a quantum dot pushed suddenly into the Kondo regime via a gate voltage using time dependent non-crossing approximation and linear response Onsager relations. We utilize graphene and metal contacts for this purpose. Instantaneous thermopower displays sinusoidal oscillations whose frequency is proportional to the energy separation between the van Hove singularity in the contact density of states and the Fermi level for both cases, regardless of the asymmetry factor at the onset of the Kondo timescale. The amplitude of the oscillations increases with decreasing temperature, saturating around the Kondo temperature. We also calculate the instantaneous figure of merit and show that the oscillations taking place at temperatures above the Kondo temperature are enhanced more than the ones occurring at lower temperatures due to the violation of the Wiedemann-Franz law. Graphene emerges as a more promising electrode candidate than ordinary metals in single electron devices since it can minimize these oscillations.

  7. Broad-Spectrum Antimicrobial Effects of Photocatalysis Using Titanium Dioxide Nanoparticles Are Strongly Potentiated by Addition of Potassium Iodide.

    Science.gov (United States)

    Huang, Ying-Ying; Choi, Hwanjun; Kushida, Yu; Bhayana, Brijesh; Wang, Yuguang; Hamblin, Michael R

    2016-09-01

    Photocatalysis describes the excitation of titanium dioxide nanoparticles (a wide-band gap semiconductor) by UVA light to produce reactive oxygen species (ROS) that can destroy many organic molecules. This photocatalysis process is used for environmental remediation, while antimicrobial photocatalysis can kill many classes of microorganisms and can be used to sterilize water and surfaces and possibly to treat infections. Here we show that addition of the nontoxic inorganic salt potassium iodide to TiO2 (P25) excited by UVA potentiated the killing of Gram-positive bacteria, Gram-negative bacteria, and fungi by up to 6 logs. The microbial killing depended on the concentration of TiO2, the fluence of UVA light, and the concentration of KI (the best effect was at 100 mM). There was formation of long-lived antimicrobial species (probably hypoiodite and iodine) in the reaction mixture (detected by adding bacteria after light), but short-lived antibacterial reactive species (bacteria present during light) produced more killing. Fluorescent probes for ROS (hydroxyl radical and singlet oxygen) were quenched by iodide. Tri-iodide (which has a peak at 350 nm and a blue product with starch) was produced by TiO2-UVA-KI but was much reduced when methicillin-resistant Staphylococcus aureus (MRSA) cells were also present. The model tyrosine substrate N-acetyl tyrosine ethyl ester was iodinated in a light dose-dependent manner. We conclude that UVA-excited TiO2 in the presence of iodide produces reactive iodine intermediates during illumination that kill microbial cells and long-lived oxidized iodine products that kill after light has ended. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  8. Strong and persistent effect on liver fat with a Paleolithic diet during a two-year intervention.

    Science.gov (United States)

    Otten, J; Mellberg, C; Ryberg, M; Sandberg, S; Kullberg, J; Lindahl, B; Larsson, C; Hauksson, J; Olsson, T

    2016-05-01

    Our objective was to investigate changes in liver fat and insulin sensitivity during a 2-year diet intervention. An ad libitum Paleolithic diet (PD) was compared with a conventional low-fat diet (LFD). Seventy healthy, obese, postmenopausal women were randomized to either a PD or a conventional LFD. Diet intakes were ad libitum. Liver fat was measured with proton magnetic resonance spectroscopy. Insulin sensitivity was evaluated with oral glucose tolerance tests and calculated as homeostasis model assessment-insulin resistance (HOMA-IR)/liver insulin resistance (Liver IR) index for hepatic insulin sensitivity and oral glucose insulin sensitivity (OGIS)/Matsuda for peripheral insulin sensitivity. All measurements were performed at 0, 6 and 24 months. Forty-one women completed the examinations for liver fat and were included. Liver fat decreased after 6 months by 64% (95% confidence interval: 54-74%) in the PD group and by 43% (27-59%) in the LFD group (P<0.01 for difference between groups). After 24 months, liver fat decreased 50% (25-75%) in the PD group and 49% (27-71%) in the LFD group. Weight reduction between baseline and 6 months was correlated to liver fat improvement in the LFD group (rs=0.66, P<0.01) but not in the PD group (rs=0.07, P=0.75). Hepatic insulin sensitivity improved during the first 6 months in the PD group (P<0.001 for Liver IR index and HOMA-IR), but deteriorated between 6 and 24 months without association with liver fat changes. A PD with ad libitum intake had a significant and persistent effect on liver fat and differed significantly from a conventional LFD at 6 months. This difference may be due to food quality, for example, a higher content of mono- and polyunsaturated fatty acids in the PD. Changes in liver fat did not associate with alterations in insulin sensitivity.

  9. Preoperative low muscle mass has a strong negative effect on pulmonary function in patients undergoing living donor liver transplantation.

    Science.gov (United States)

    Shirai, Hisaya; Kaido, Toshimi; Hamaguchi, Yuhei; Yao, Siyuan; Kobayashi, Atsushi; Okumura, Shinya; Kamo, Naoko; Yagi, Shintaro; Okajima, Hideaki; Uemoto, Shinji

    2018-01-01

    This study investigated the effect of preoperative sarcopenia on cardiopulmonary function in patients undergoing living donor liver transplantation (LDLT). A retrospective analysis was performed of 207 patients who underwent LDLT between January 2008 and April 2015. The quantity and quality of skeletal muscle were evaluated by the psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC), respectively, using preoperative computed tomography imaging. The correlations between preoperative cardiopulmonary function and sarcopenic factors (PMI, IMAC, and grip strength [GS]) were examined. Moreover, overall survival (OS) rates according to preoperative pulmonary function and risk factors were analyzed. No significant differences were found between ejection fraction (EF) and these sarcopenic factors. In contrast, preoperative vital capacity (VC) and forced expiratory volume (FEV) 1.0 were significantly correlated with PMI (P < 0.001, P < 0.001), IMAC (P = 0.024, P = 0.013), and GS (P = 0.006, P = 0.033) in males. Preoperative VC and FEV1.0 were significantly correlated with IMAC (P = 0.002, P = 0.001) and GS (P = 0.002, P = 0.001) in females. Moreover, %VC, VC, and FEV1.0 in the preoperative low muscle mass group were significantly lower than in the normal muscle mass group (P = 0.004, P < 0.001, P < 0.001, respectively) in males. Multivariate analysis revealed that preoperative low PMI and preoperative restrictive ventilatory impairment were independent risk factors (P = 0.046 and P = 0.014, respectively). Preoperative low muscle mass was closely involved with pulmonary dysfunction in patients undergoing LDLT. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Strong effect of SNP rs4988300 of the LRP5 gene on bone phenotype of Caucasian postmenopausal women.

    Science.gov (United States)

    Horváth, Péter; Balla, Bernadett; Kósa, János P; Tóbiás, Bálint; Szili, Balázs; Kirschner, Gyöngyi; Győri, Gabriella; Kató, Karina; Lakatos, Péter; Takács, István

    2016-01-01

    The purpose of this study was to identify relationships between single nucleotide polymorphisms (SNPs) in the genes of the Wnt pathway and bone mineral density (BMD) of postmenopausal women. We chose this pathway due to its importance in bone metabolism that was underlined in several studies. DNA samples of 932 Hungarian postmenopausal women were studied. First, their BMD values at different sites (spine, total hip) were measured, using a Lunar Prodigy DXA scanner. Thereafter, T-score values and the patients' body mass indices (BMIs) were calculated, while information about the fracture history of the sample population was also collected. We genotyped nine SNPs of the following three genes: LRP5, GPR177, and SP7, using a Sequenom MassARRAY Analyzer 4 instrument. The genomic DNA samples used for genotyping were extracted from the buccal mucosa of the subjects. Statistical analyses were carried out using the SPSS 21 and R package. The results of this analysis showed a significant association between SNP rs4988300 of the LRP5 gene and total hip BMD values. We could not reveal any associations between the markers of GPR177, SP7, and bone phenotypes. We found no effect of these genotypes on fracture risk. We could demonstrate a significant gene-gene interaction between two SNPs of LRP5 (rs4988300 and rs634008, p = 0.009) which was lost after Bonferroni correction. We could firmly demonstrate a significant association between rs4988300 of the LRP5 gene and bone density of the hip on the largest homogeneous postmenopausal study group analyzed to date. Our finding corroborates the relationship between LRP5 genotype and bone phenotype in postmenopausal women, however, the complete mechanism of this relationship requires further investigations.

  11. PedHunter 2.0 and its usage to characterize the founder structure of the Old Order Amish of Lancaster County

    Directory of Open Access Journals (Sweden)

    Agarwala Richa

    2010-05-01

    Full Text Available Abstract Background Because they are a closed founder population, the Old Order Amish (OOA of Lancaster County have been the subject of many medical genetics studies. We constructed four versions of Anabaptist Genealogy Database (AGDB using three sources of genealogies and multiple updates. In addition, we developed PedHunter, a suite of query software that can solve pedigree-related problems automatically and systematically. Methods We report on how we have used new features in PedHunter to quantify the number and expected genetic contribution of founders to the OOA. The queries and utility of PedHunter programs are illustrated by examples using AGDB in this paper. For example, we calculated the number of founders expected to be contributing genetic material to the present-day living OOA and estimated the mean relative founder representation for each founder. New features in PedHunter also include pedigree trimming and pedigree renumbering, which should prove useful for studying large pedigrees. Results With PedHunter version 2.0 querying AGDB version 4.0, we identified 34,160 presumed living OOA individuals and connected them into a 14-generation pedigree descending from 554 founders (332 females and 222 males after trimming. From the analysis of cumulative mean relative founder representation, 128 founders (78 females and 50 males accounted for over 95% of the mean relative founder contribution among living OOA descendants. Discussion/Conclusions The OOA are a closed founder population in which a modest number of founders account for the genetic variation present in the current OOA population. Improvements to the PedHunter software will be useful in future studies of both the OOA and other populations with large and computerized genealogies.

  12. Strong effect of copper(II) coordination on antiproliferative activity of thiosemicarbazone-piperazine and thiosemicarbazone-morpholine hybrids.

    Science.gov (United States)

    Bacher, Felix; Dömötör, Orsolya; Chugunova, Anastasia; Nagy, Nóra V; Filipović, Lana; Radulović, Siniša; Enyedy, Éva A; Arion, Vladimir B

    2015-05-21

    In this study, 2-formylpyridine thiosemicarbazones and three different heterocyclic pharmacophores were combined to prepare thiosemicarbazone–piperazine mPip-FTSC (HL1) and mPip-dm-FTSC (HL2), thiosemicarbazone–morpholine Morph-FTSC (HL3) and Morph-dm-FTSC (HL4), thiosemicarbazone–methylpyrrole-2-carboxylate hybrids mPyrr-FTSC (HL5) and mPyrr-dm-FTSC (HL6) as well as their copper(II) complexes [CuCl(mPipH-FTSC-H)]Cl (1 + H)Cl, [CuCl(mPipH-dm-FTSC-H)]Cl (2 + H)Cl, [CuCl(Morph-FTSC-H)] (3), [CuCl(Morph-dm-FTSC-H)] (4), [CuCl(mPyrr-FTSC-H)(H2O)] (5) and [CuCl(mPyrr-dm-FTSC-H)(H2O)] (6). The substances were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy (HL1–HL6), ESI mass spectrometry, IR and UV–vis spectroscopy and single crystal X-ray diffraction (1–5). All compounds were prepared in an effort to generate potential antitumor agents with an improved therapeutic index. In addition, the effect of structural alterations with organic hybrids on aqueous solubility and copper(II) coordination ability was investigated. Complexation of ligands HL2 and HL4 with copper(II) was studied in aqueous solution by pH-potentiometry, UV–vis spectrophotometry and EPR spectroscopy. Proton dissociation processes of HL2 and HL4 were also characterized in detail and microscopic constants for the Z/E isomers were determined. While the hybrids HL5, HL6 and their copper(II) complexes 5 and 6 proved to be insoluble in aqueous solution, precluding antiproliferative activity studies, the thiosemicarbazone–piperazine and thiosemicarbazone–morpholine hybrids HL1–HL4, as well as copper(II) complexes 1–4 were soluble in water enabling cytotoxicity assays. Interestingly, the metal-free hybrids showed very low or even a lack of cytotoxicity (IC50 values > 300 μM) in two human cancer cell lines HeLa (cervical carcinoma) and A549 (alveolar basal adenocarcinoma), whereas their copper(II) complexes were cytotoxic showing IC50 values from 25.5 to 65.1

  13. Electric quadrupole moments and strong interaction effects in pionic atoms of 165Ho, 175Lu, 176Lu, 179Hf and 181Ta

    International Nuclear Information System (INIS)

    Olaniyi, B.; Shor, A.; Cheng, S.C.; Dugan, G.; Wu, C.S.

    1981-05-01

    The effective quadrupole moments Q sub(eff) of the nuclei of 165 Ho, 175 Lu, 176 Lu, 179 Hf and 181 Ta were accurately measured by detecting the pionic atom 5g-4f x-rays of the elements. The spectroscopic quadrupole moments, Q sub(spec), were obtained by correcting Q sub(eff) for nuclear finite size effect, distortion of the pion wave function by the pion-nucleus strong interaction, and contribution to the energy level splittings by the strong interaction. The intrinsic quadrupole moments, Q 0 , were obtained by projecting Q sub(spec) into the frame of reference fixed on the nucleus. The shift, epsilon 0 , and broadening, GAMMA 0 , of the 4f energy level due to the strong interactions between the pion and the nucleons for all the elements were also measured. Theoretical values of epsilon 0 and GAMMA 0 were calculated and compared to the experimental values. The measured values of Q 0 were compared with the existing results in muonic and pionic atoms. The measured values of epsilon 0 and GAMMA 0 were also compared with existing values. (auth)

  14. The founder of the church of Saint George at Pološko

    Directory of Open Access Journals (Sweden)

    Pavlović Dragana

    2015-01-01

    Full Text Available The paper seeks to establish who was the founder of the church of Saint George at Pološko and revise the conclusions of previous researchers regarding this issue. According to the opinion commonly adopted in the scholarly literature, Jovan Dragušin, a cousin of King Dušan, had merely undertaken the construction of church at Pološko, whereas his mother was responsible for the completion of construction and painting of frescoes in the church. Through an analysis of written and visual sources the conclusion is reached that the sole person responsible for the construction and painting of the church at Pološko was the nun Maria, the mother of Jovan Dragušin. [Projekat Ministarstva nauke Republike Srbije, br. 177036: Srpska srednjovekovna umetnost i njen evropski kontekst

  15. Preconception carrier screening for multiple disorders: evaluation of a screening offer in a Dutch founder population.

    Science.gov (United States)

    Mathijssen, Inge B; Holtkamp, Kim C A; Ottenheim, Cecile P E; van Eeten-Nijman, Janneke M C; Lakeman, Phillis; Meijers-Heijboer, Hanne; van Maarle, Merel C; Henneman, Lidewij

    2018-02-01

    Technological developments have enabled carrier screening for multiple disorders. This study evaluated experiences with a preconception carrier screening offer for four recessive disorders in a Dutch founder population. Questionnaires were completed by 182 attendees pretesting and posttesting and by 137 non-attendees. Semistructured interviews were conducted with seven of the eight carrier couples. Attendees were mainly informed about the existence of screening by friends/colleagues (49%) and family members (44%). Familiarity with the genetic disorders was high. Knowledge after counseling increased (p influencers (family/friends) can be used to raise awareness of a screening offer. Our findings provide lessons for the implementation of expanded carrier screening panels in other communities and other settings.

  16. The first independent pharmacognosy institute in the world and its founder Julije Domac (1853-1928).

    Science.gov (United States)

    Inić, S; Kujundzić, N

    2011-09-01

    The aim of this article is to describe the foundation and development of the first distinct Institute of Pharmacognosy in the world and to provide a biography of its founder Julije Domac. The Institute was founded in 1896 as a separate institution at the University of Zagreb, Croatia, part of the Austro-Hungarian Empire at the time. In other European university centers, pharmacognosy institutes were founded together with pharmacology, botany, pharmaceutical or general chemistry. Julije Domac (1853-1928) graduated pharmacy from the University of Vienna (1874) and received his Ph.D. from the University of Graz (1880) with a paper elucidating the structure of hexene and mannitol obtained from manna. He lectured pharmacognosy at the University of Zagreb (1887-1924), wrote chemistry and pharmacognosy textbooks, and co-wrote the Croatian-Slavonian Pharmacopoeia.

  17. A few words about the founder of the Macedonian modern sculpture

    Directory of Open Access Journals (Sweden)

    Marković Kamenko M.

    2016-01-01

    Full Text Available This paper discusses the life and work of Dima Todorovski, the founder of the Macedonian modern sculpture. Dimo Todorovski was born in Thessaloniki in 1910. He finished the Art School, the sculpture department, in Belgrade in 1935. He lived and worked in Skopje from 1942 until his death in 1983. During his career, he made an impressive number of sculptures among which are portraits, lovely female nudes, figures of men in motion, and other pieces related to the WWII. His best pieces include: The Portrait of the Artist's Mother, A Peasant Woman Portrait, The Pit, The Macedonian Pieta, A Girl, A monument in honour of Koco Racin, The Miladinov Brothers, St. Kliment Ohridski.

  18. <strong>Neuroeconomics and Human Resource Developmentstrong>/>

    DEFF Research Database (Denmark)

    Larsen, Torben

    2009-01-01

    threats and personal stress. So far, the evidence-based findings on human resource development (HRD) seem not to match these huge challenges. The aim of this study is to identify cost-effective means of mental training to recover sufficiently from the present bias to enable more sustainable decisions...... making as required to meet the global challenges in study as confirmed by an intercultural neuroeconomic comparative study between Asian and Western cultures. However, a cultural barrier in the Western cultural tradition against meditative introversion has to be overcome to improve the time horizon...... meditation, Harvard relaxation procedure, ACEM meditation and Autogenic training. IV. Broad health effects of regular medical meditation are evidenced by RCT and even reviews/meta-analysis in more medical meditation settings: Recovery from basal anxiety Stabilization of plasma cortisol Independence...

  19. Mitochondrial Genome Diversity of Native Americans Supports a Single Early Entry of Founder Populations into America

    Science.gov (United States)

    Silva Jr., Wilson A.; Bonatto, Sandro L.; Holanda, Adriano J.; Ribeiro-dos-Santos, Andrea K.; Paixão, Beatriz M.; Goldman, Gustavo H.; Abe-Sandes, Kiyoko; Rodriguez-Delfin, Luis; Barbosa, Marcela; Paçó-Larson, Maria Luiza; Petzl-Erler, Maria Luiza; Valente, Valeria; Santos, Sidney E. B.; Zago, Marco A.

    2002-01-01

    There is general agreement that the Native American founder populations migrated from Asia into America through Beringia sometime during the Pleistocene, but the hypotheses concerning the ages and the number of these migrations and the size of the ancestral populations are surrounded by controversy. DNA sequence variations of several regions of the genome of Native Americans, especially in the mitochondrial DNA (mtDNA) control region, have been studied as a tool to help answer these questions. However, the small number of nucleotides studied and the nonclocklike rate of mtDNA control-region evolution impose several limitations to these results. Here we provide the sequence analysis of a continuous region of 8.8 kb of the mtDNA outside the D-loop for 40 individuals, 30 of whom are Native Americans whose mtDNA belongs to the four founder haplogroups. Haplogroups A, B, and C form monophyletic clades, but the five haplogroup D sequences have unstable positions and usually do not group together. The high degree of similarity in the nucleotide diversity and time of differentiation (i.e., ∼21,000 years before present) of these four haplogroups support a common origin for these sequences and suggest that the populations who harbor them may also have a common history. Additional evidence supports the idea that this age of differentiation coincides with the process of colonization of the New World and supports the hypothesis of a single and early entry of the ancestral Asian population into the Americas. PMID:12022039

  20. Nationwide study on hypertrophic cardiomyopathy in Iceland: evidence of a MYBPC3 founder mutation.

    Science.gov (United States)

    Adalsteinsdottir, Berglind; Teekakirikul, Polakit; Maron, Barry J; Burke, Michael A; Gudbjartsson, Daniel F; Holm, Hilma; Stefansson, Kari; DePalma, Steven R; Mazaika, Erica; McDonough, Barbara; Danielsen, Ragnar; Seidman, Jonathan G; Seidman, Christine E; Gunnarsson, Gunnar T

    2014-09-30

    The geographic isolation and homogeneous population of Iceland are ideally suited to ascertain clinical and genetic characteristics of hypertrophic cardiomyopathy (HCM) at the population level. Medical records and cardiac imaging studies obtained between 1997 and 2010 were reviewed to identify Icelandic patients with HCM. Surviving patients were recruited for clinical and genetic studies. A previously identified Icelandic mutation, MYBPC3 c.927-2A>G, was genotyped, and mutation-negative samples were sequenced for HCM genes and other hypertrophic genes. Record review identified 180 patients with HCM. Genetic analyses of 151 patients defined pathogenic mutations in 101 (67%), including MYBPC3 c.927-2A>G (88 patients, 58%), 4 other MYBPC3 or MYH7 mutations (5 patients, 3.3%), and 2 GLA mutations (8 patients, 5.3%). Haplotype and genetic genealogical data defined MYBPC3 c.927-2A>G as a founder mutation, introduced into the Icelandic population in the 15th century, with a current population prevalence of 0.36%. MYBPC3 c.927-2A>G mutation carriers exhibited phenotypic diversity but were younger at diagnosis (42 versus 49 years; P=0.001) and sustained more adverse events (15% versus 2%; P=0.02) than mutation-negative patients. All-cause mortality for patients with HCM was similar to that of an age-matched Icelandic population (hazard ratio, 0.98; P=0.9). HCM-related mortality (0.78%/y) occurred at a mean age of 68 compared with 81 years for non-HCM-related mortality (P=0.02). A founder MYBPC3 mutation that arose >550 years ago is the predominant cause of HCM in Iceland. The MYBPC3 c.927-2A>G mutation is associated with low adverse event rates but earlier cardiovascular mortality, illustrating the impact of genotype on outcomes in HCM. © 2014 American Heart Association, Inc.

  1. An Ashkenazi founder mutation in the MSH6 gene leading to HNPCC.

    Science.gov (United States)

    Goldberg, Yael; Porat, Rinnat M; Kedar, Inbal; Shochat, Chen; Galinsky, Daliah; Hamburger, Tamar; Hubert, Ayala; Strul, Hana; Kariiv, Revital; Ben-Avi, Liat; Savion, Moran; Pikarsky, Eli; Abeliovich, Dvorah; Bercovich, Dani; Lerer, Israela; Peretz, Tamar

    2010-06-01

    Mutations in DNA mismatch repair genes underlie lynch syndrome (HNPCC). Lynch syndrome resulting from mutations in MSH6 is considered to be attenuated in comparison to that caused by mutations in MLH1 and MSH2, thus more likely to be under diagnosed. In this study we report of a common mutation in the MSH6 gene in Ashkenazi Jews. Genetic counseling and diagnostic work-up for HNPCC was conducted in families who attended the high risk clinic for inherited cancer. We identified the mutation c.3984_3987dup in the MSH6 gene in 19 members of four unrelated Ashkenazi families. This mutation results in truncation of the transcript and in loss of expression of the MSH6 protein in tumors. Tumor spectrum among carriers included colon, endometrial, gastric, ovarian, urinary, and breast cancer. All but one family qualified for the Bethesda guidelines and none fulfilled the Amsterdam Criteria. Members of one family also co-inherited the c.6174delT mutation in the BRCA2 gene. The c.3984_3987dup in the MSH6 gene is a mutation leading to HNPCC among Ashkenazi Jews. This is most probably a founder mutation. In contrast to the c.1906G>C founder mutation in the MSH2 gene, tumors tend to occur later in life, and none of the families qualified for the Amsterdam criteria. c.3984_3987dup is responsible for 1/6 of the mutations identified among Ashkenazi HNPCC families in our cohort. Both mutations: c.3984_3987dup and c.1906G>C account for 61% of HNPCC Ashkenazi families in this cohort. These findings are of great importance for counseling, diagnosis, management and surveillance for Ashkenazi families with Lynch syndrome.

  2. The Emergence of a Myth : In search of the origins of the life story of Shenrab Miwo, the founder of Bon

    NARCIS (Netherlands)

    Gurung, Kalsang Norbu

    2011-01-01

    In this dissertation, I have focused on the construction of the life account of the founder of Bon Religion, Shenrab Miwo. I try to answer some key questions such as, who was Shenrab Miwo and why is he considered to have been the founder of Bon? How did the hagiography of Shenrab Miwo emerge and how

  3. <strong>Neuroeconomics and Health Economicsstrong>/>

    DEFF Research Database (Denmark)

    Larsen, Torben

    2009-01-01

    activation of Amygdala - a key center in our emotional arousal (limbic system) - as shaped in the elder stone-age with many acute threats. II. In general, the Hawthorne-effect of management is explained as the result of supportive job-relations reinforcing the homeostatic properties of the limbic system...... with de-stressing benefits as reduced anxiety, less use of stimulants and a reduction of blood pressure which in all increase life-expectancy. Conclusion: Neuroeconomics helps economists to identify dominant health economic interventions that may be overlooked by traditional discipålines   [i] This part...

  4. SOLVENT EFFECTS ON THE HYDRATION OF CYCLOHEXENE CATALYZED BY A STRONG ACID ION-EXCHANGE RESIN .3. EFFECT OF SULFOLANE ON THE EQUILIBRIUM CONVERSION

    NARCIS (Netherlands)

    PANNEMAN, HJ; BEENACKERS, AACM

    The liquid-phase hydration of cyclohexene, a pseudo-first-order reversible reaction catalyzed by a strong acid ion-exchange resin, was investigated in solvent mixtures of water and sulfolane. Macroporous Amberlite XE 307 was used because of its superior catalytic activity. Chemical equilibrium

  5. Achievement Motivation, Strategic Orientations, and Business Performance in Entrepreneurial Firms: How Different are Japanese and Americans Founders?

    NARCIS (Netherlands)

    Deshpande, R.; Grinstein, A.; Sang-Hoon, K.; Ofek, E.

    2013-01-01

    Purpose: There is a lack of research on the link between the personal disposition of an entrepreneurial firm's founder, the firm's strategic orientation and its performance outcomes. Also, there is a lack of cross-national research on entrepreneurial firms' strategic orientations. This paper seeks

  6. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela

    2011-01-01

    individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences...

  7. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela

    2011-01-01

    individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 +/- 215 years ago. We further demonstrate significant quantitative differences...

  8. 76 FR 35263 - Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business...

    Science.gov (United States)

    2011-06-16

    ... SMALL BUSINESS ADMINISTRATION [License No. 02/72-0625] Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is... 107.730, Financings Which Constitute Conflicts of Interest of the Small Business Administration (``SBA...

  9. 77 FR 76586 - Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business...

    Science.gov (United States)

    2012-12-28

    ... SMALL BUSINESS ADMINISTRATION [License No. 02/72-0625] Founders Equity SBIC I, L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is... 107.730, Financings which Constitute Conflicts of Interest of the Small Business Administration (``SBA...

  10. TGfU--Would You Know It if You Saw It? Benchmarks from the Tacit Knowledge of the Founders

    Science.gov (United States)

    Butler, Joy

    2014-01-01

    This paper explores the tacit expert knowledge and understanding about games curriculum and pedagogy of three men, Len Almond, David Bunker, and Rod Thorpe, credited as the founders of the Teaching Games for Understanding (TGfU) model. The model emerged from teacher practice in the late 1970s and was little theorized at the time, apart from a…

  11. Impact on electroencephalography of Adolf Beck, a prominent Polish scientist and founder of the Lviv School of Physiology

    NARCIS (Netherlands)

    Zayachkivska, O.; Gzhegotsky, M.; Coenen, A.M.L.

    2012-01-01

    Adolf Beck (1863–1942) can be regarded as the co-founder of electroencephalography. His studies on the cerebral cortex of animals have facilitated the introduction of the electroencephalogram (EEG) as a main tool for studying the brain. The localization of senses on the cortex with evoked potentials

  12. Elon Musk, founder of SpaceX and PayPal, to speak on campus Feb. 21

    OpenAIRE

    Crumbley, Liz

    2006-01-01

    Elon Musk, founder and chief executive officer of Space Exploration Technologies Co. (SpaceX), will speak on his company's Falcon rocket series and the future of university space research on Tuesday, Feb. 21 at 7:30 p.m. in Virginia Tech's Burruss Hall Auditorium. The event is free and open to the public.

  13. <strong>Neuroeconomics and behavioral health economicsstrong>/>

    DEFF Research Database (Denmark)

    Larsen, Torben

    2009-01-01

    dissemination of relaxation procedures is evident in industrialized countries since about 1970 both inside the medical healthcare system and as NGO-settings in a market-alike competition. However, a serious barrier to the dissemination of meditative de-stressing is the lack of general knowledge of the action...... for explanation of the neural dynamics of normal decision making. Secondly, the literature is reviewed for evidence on hypothesized applications of NeM in behavioral health. Results I. The present bias as documented by neuroeconomic game-trials is explained by NeM as rooted in the basal activation of Amygdala...... - a key center in our emotional arousal (limbic system) - as shaped in the elder stone-age with many acute threats. II. In general, the Hawthorne-effect of human-relations management is explained as the result of supportive job-relations relaxing Amygdala for better emotional integration...

  14. <strong>Neuroeconomics and behavioral health economicsstrong>/>

    DEFF Research Database (Denmark)

    Larsen, Torben

    2009-01-01

    - a key center in our emotional arousal (limbic system) - as shaped in the elder stone-age with many acute threats. II. In general, the Hawthorne-effect of human-relations management is explained as the result of supportive job-relations relaxing Amygdala for better emotional integration...... some are rooted in the religious tradition while other aim to be post-religious. Medical meditation across settings combines savings on health care costs with de-stressing benefits as reduced anxiety, less use of stimulants and a reduction of blood pressure which in all increase life...... is met by a meso-strategy aiming the formation of an international, multidisciplinary network which might organize regional workshops for representatives for all involved parties in order to prepare local implementation projects.   Regarding de-stressing by medical meditation a relatively fast...

  15. Effects of strong CYP2D6 and 3A4 inhibitors, paroxetine and ketoconazole, on the pharmacokinetics and cardiovascular safety of tamsulosin

    Science.gov (United States)

    Troost, Joachim; Tatami, Shinji; Tsuda, Yasuhiro; Mattheus, Michaela; Mehlburger, Ludwig; Wein, Martina; Michel, Martin C

    2011-01-01

    AIM To determine the effect of the strong CYP2D6 inhibitor paroxetine and strong CYP3A4 inhibitor ketoconazole on the pharmacokinetics and safety (orthostatic challenge) of tamsulosin. METHODS Two open-label, randomized, two-way crossover studies were conducted in healthy male volunteers (extensive CYP2D6 metabolizers). RESULTS Co-administration of multiple oral doses of 20 mg paroxetine once daily with a single oral dose of the 0.4 mg tamsulosin HCl capsule increased the adjusted geometric mean (gMean) values of Cmax and AUC(0,∞) of tamsulosin by factors of 1.34 (90% CI 1.21, 1.49) and 1.64 (90% CI 1.44, 1.85), respectively, and increased the terminal half-life (t1/2) of tamsulosin HCl from 11.4 h to 15.3 h. Co-administration of multiple oral doses of 400 mg ketoconazole once dailywith a single oral dose of the 0.4 mg tamsulosin increased the gMean values of Cmax and AUC(0,∞) of tamsulosin by a factor of 2.20 (90% CI 1.96, 2.45) and 2.80 (90% CI 2.56, 3.07), respectively. The terminal half-life was slightly increased from 10.5 h to 11.8 h. These pharmacokinetic changes were not accompanied by clinically significant alterations of haemodynamic responses during orthostatic stress testing. CONCLUSION The exposure to tamsulosin is increased upon co-administration of strong CYP2D6 inhibitors and even more so of strong 3A4 inhibitors, but neither PK alteration was accompanied by clinically significant haemodynamic changes during orthostatic stress testing. PMID:21496064

  16. Identification of BRCA1/2 founder mutations in Southern Chinese breast cancer patients using gene sequencing and high resolution DNA melting analysis.

    Directory of Open Access Journals (Sweden)

    Ava Kwong

    Full Text Available Ethnic variations in breast cancer epidemiology and genetics have necessitated investigation of the spectra of BRCA1 and BRCA2 mutations in different populations. Knowledge of BRCA mutations in Chinese populations is still largely unknown. We conducted a multi-center study to characterize the spectra of BRCA mutations in Chinese breast and ovarian cancer patients from Southern China.A total of 651 clinically high-risk breast and/or ovarian cancer patients were recruited from the Hong Kong Hereditary Breast Cancer Family Registry from 2007 to 2011. Comprehensive BRCA1 and BRCA2 mutation screening was performed using bi-directional sequencing of all coding exons of BRCA1 and BRCA2. Sequencing results were confirmed by in-house developed full high resolution DNA melting (HRM analysis. Among the 451 probands analyzed, 69 (15.3% deleterious BRCA mutations were identified, comprising 29 in BRCA1 and 40 in BRCA2. The four recurrent BRCA1 mutations (c.470_471delCT, c.3342_3345delAGAA, c.5406+1_5406+3delGTA and c.981_982delAT accounted for 34.5% (10/29 of all BRCA1 mutations in this cohort. The four recurrent BRCA2 mutations (c.2808_2811delACAA, c.3109C>T, c.7436_7805del370 and c.9097_9098insA accounted for 40% (16/40 of all BRCA2 mutations. Haplotype analysis was performed to confirm 1 BRCA1 and 3 BRCA2 mutations are putative founder mutations. Rapid HRM mutation screening for a panel of the founder mutations were developed and validated.In this study, our findings suggest that BRCA mutations account for a substantial proportion of hereditary breast/ovarian cancer in Southern Chinese population. Knowing the spectrum and frequency of the founder mutations in this population will assist in the development of a cost-effective rapid screening assay, which in turn facilitates genetic counseling and testing for the purpose of cancer risk assessment.

  17. Strongly Correlated Topological Insulators

    Science.gov (United States)

    2016-02-03

    Strongly Correlated Topological Insulators In the past year, the grant was used for work in the field of topological phases, with emphasis on finding...surface of topological insulators. In the past 3 years, we have started a new direction, that of fractional topological insulators. These are materials...in which a topologically nontrivial quasi-flat band is fractionally filled and then subject to strong interactions. The views, opinions and/or

  18. Strong Cosmic Censorship

    Science.gov (United States)

    Isenberg, James

    2017-01-01

    The Hawking-Penrose theorems tell us that solutions of Einstein's equations are generally singular, in the sense of the incompleteness of causal geodesics (the paths of physical observers). These singularities might be marked by the blowup of curvature and therefore crushing tidal forces, or by the breakdown of physical determinism. Penrose has conjectured (in his `Strong Cosmic Censorship Conjecture`) that it is generically unbounded curvature that causes singularities, rather than causal breakdown. The verification that ``AVTD behavior'' (marked by the domination of time derivatives over space derivatives) is generically present in a family of solutions has proven to be a useful tool for studying model versions of Strong Cosmic Censorship in that family. I discuss some of the history of Strong Cosmic Censorship, and then discuss what is known about AVTD behavior and Strong Cosmic Censorship in families of solutions defined by varying degrees of isometry, and discuss recent results which we believe will extend this knowledge and provide new support for Strong Cosmic Censorship. I also comment on some of the recent work on ``Weak Null Singularities'', and how this relates to Strong Cosmic Censorship.

  19. <strong>PRAYER INDUCED ANALGESIAstrong>

    DEFF Research Database (Denmark)

    Jegindø, Else-Marie Elmholdt

    moderators (personality, absorption and coping) and mediators (expectations, desire for pain relief and anxiety) were included in the study design in order to explore the influence of psychological mechanisms involved in the potential analgesic effect of prayer as a coping strategy. RESULTS: TBA (it...

  20. Mitogenomic and microsatellite variation in descendants of the founder population of Newfoundland: high genetic diversity in an historically isolated population.

    Science.gov (United States)

    Pope, A M; Carr, S M; Smith, K N; Marshall, H D

    2011-02-01

    The island of Newfoundland, the first of England's overseas colonies, was settled from the 17th century onward by restricted numbers of English, Irish, and French immigrants, in small "outport" communities that have maintained geographic, religious, and linguistic isolation to the latest generations. To measure the extent of modification and loss of genetic variation through founder effect, drift, and inbreeding in this historically isolated population, we analyzed the complete mitochondrial DNA (mtDNA) genomes and 14 microsatellite loci from each of 27 individuals with matrilineal ancestries extending to the colonial period. Every individual has a unique mtDNA genome sequence. All but one of these genomes are assignable to one of five major (H,J,K,T, and U) or minor (I) European haplogroups. The possibility of homoplasy at single nucleotide polymorphism (SNP) sites that define subtypes within the H haplogroup is discussed. Observed haplogroup proportions do not differ significantly from those of western Europeans or between English and Irish Newfoundlanders. The exceptional individual is a member of haplogroup A2, who appears to be the descendant of a Mi'kmaq First Nations mother and a French father, a common marriage pattern in the early settlement of Newfoundland. Microsatellite diversity is high (HE = 0.763), unstructured with respect to mtDNA haplotype or ethnicity, and there is no evidence of linkage disequilibrium. There is a small but significant degree of inbreeding (FIS = 0.0174). Collection of whole mtDNA genome data was facilitated by the use of microarray sequencing, and we describe a simple algorithm that is 99.67% efficient for sequence recovery.

  1. A founder AGL mutation causing glycogen storage disease type IIIa in Inuit identified through whole-exome sequencing: a case series.

    Science.gov (United States)

    Rousseau-Nepton, Isabelle; Okubo, Minoru; Grabs, Rosemarie; Mitchell, John; Polychronakos, Constantin; Rodd, Celia

    2015-02-03

    Glycogen storage disease type III is caused by mutations in both alleles of the AGL gene, which leads to reduced activity of glycogen-debranching enzyme. The clinical picture encompasses hypoglycemia, with glycogen accumulation leading to hepatomegaly and muscle involvement (skeletal and cardiac). We sought to identify the genetic cause of this disease within the Inuit community of Nunavik, in whom previous DNA sequencing had not identified such mutations. Five Inuit children with a clinical and biochemical diagnosis of glycogen storage disease type IIIa were recruited to undergo genetic testing: 2 underwent whole-exome sequencing and all 5 underwent Sanger sequencing to confirm the identified mutation. Selected DNA regions near the AGL gene were also sequenced to identify a potential founder effect in the community. In addition, control samples from 4 adults of European descent and 7 family members of the affected children were analyzed for the specific mutation by Sanger sequencing. We identified a homozygous frame-shift deletion, c.4456delT, in exon 33 of the AGL gene in 2 children by whole-exome sequencing. Confirmation by Sanger sequencing showed the same mutation in all 5 patients, and 5 family members were found to be carriers. With the identification of this mutation in 5 probands, the estimated prevalence of genetically confirmed glycogen storage disease type IIIa in this region is among the highest worldwide (1:2500). Despite identical mutations, we saw variations in clinical features of the disease. Our detection of a homozygous frameshift mutation in 5 Inuit children determines the cause of glycogen storage disease type IIIa and confirms a founder effect. © 2015 Canadian Medical Association or its licensors.

  2. Calculation of effective electromagnetic parameters of multi-needle zinc oxide whisker based on equivalent spherical particle and strong fluctuation theory

    Science.gov (United States)

    Zhao, Yu-Chen; Liu, Jiang-Fan; Song, Zhong-Guo; Xi, Xiao-Li

    2014-12-01

    Multi-needle zinc oxide whisker (M-ZnOw) includes tetrapod-needle ZnOw (T-ZnOw), flower-shaped ZnOw, and other similar ZnOw architectures. The unique three-dimensional (3D) and multi-needle-shaped structures give the special performance of M-ZnOw, but make it difficult to calculate the effective electromagnetic parameters of M-ZnOw composites. In this paper, based on the equivalent spherical particle and the strong fluctuation theory, three different closed-form expressions are presented to calculate the effective electromagnetic parameters of M-ZnOw composites. To start with, because of the macroscopic isotropic nature of M-ZnOw composites and lossy properties of M-ZnOw itself, an equivalent spherical particle is introduced in the scheme to simplify the unique microscopic structures of M-ZnOw, and the possible limitations of the presented equivalent spherical particle are discussed qualitatively. In addition, different closed-form expressions to calculate the effective electromagnetic parameter are obtained by means of representing the physical situations of conductive network as different correlation functions in the strong fluctuation theory. Finally, the effective permeability of a T-ZnOw/Fe - paraffin composite is calculated by these three expressions in 2-18 GHz frequency range. Very good agreement between the calculated and experimental results on one hand verifies the rationality of presented expressions, and on the other hand indicates that the correlation function plays an important role in improving the performance of the presented expression.

  3. Inactivation of pathogenic viruses by plant-derived tannins: strong effects of extracts from persimmon (Diospyros kaki on a broad range of viruses.

    Directory of Open Access Journals (Sweden)

    Kyoko Ueda

    Full Text Available Tannins, plant-derived polyphenols and other related compounds, have been utilized for a long time in many fields such as the food industry and manufacturing. In this study, we investigated the anti-viral effects of tannins on 12 different viruses including both enveloped viruses (influenza virus H3N2, H5N3, herpes simplex virus-1, vesicular stomatitis virus, Sendai virus and Newcastle disease virus and non-enveloped viruses (poliovirus, coxsachievirus, adenovirus, rotavirus, feline calicivirus and mouse norovirus. We found that extracts from persimmon (Diospyros kaki, which contains ca. 22% of persimmon tannin, reduced viral infectivity in more than 4-log scale against all of the viruses tested, showing strong anti-viral effects against a broad range of viruses. Other tannins derived from green tea, acacia and gallnuts were effective for some of the viruses, while the coffee extracts were not effective for any of the virus. We then investigated the mechanism of the anti-viral effects of persimmon extracts by using mainly influenza virus. Persimmon extracts were effective within 30 seconds at a concentration of 0.25% and inhibited attachment of the virus to cells. Pretreatment of cells with the persimmon extracts before virus infection or post-treatment after virus infection did not inhibit virus replication. Protein aggregation seems to be a fundamental mechanism underlying the anti-viral effect of persimmon tannin, since viral proteins formed aggregates when purified virions were treated with the persimmon extracts and since the anti-viral effect was competitively inhibited by a non-specific protein, bovine serum albumin. Considering that persimmon tannin is a food supplement, it has a potential to be utilized as a safe and highly effective anti-viral reagent against pathogenic viruses.

  4. Donor T cells primed on leukemia lysate-pulsed recipient APCs mediate strong graft-versus-leukemia effects across MHC barriers in full chimeras.

    Science.gov (United States)

    Ghosh, Arnab; Koestner, Wolfgang; Hapke, Martin; Schlaphoff, Verena; Länger, Florian; Baumann, Rolf; Koenecke, Christian; Cornberg, Markus; Welte, Karl; Blazar, Bruce R; Sauer, Martin G

    2009-04-30

    Antigen-presenting cells (APCs) of host origin drive graft-versus-leukemia (GVL) effects but can also trigger life-threatening graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) across major histocompatibility complex (MHC) barriers. We show that in vitro priming of donor lymphocytes can circumvent the need of recipient-derived APCs in vivo for mediating robust GVL effects and significantly diminishes the risk of severe GVHD. In vitro, generated and expanded T cells (ETCs) mediate anti-leukemia effects only when primed on recipient-derived APCs. Loading of APCs in vitro with leukemia cell lysate, chimerism status of the recipient, and timing of adoptive transfer after HCT are important factors determining the outcome. Delayed transfer of ETCs resulted in strong GVL effects in leukemia-bearing full chimera (FC) and mixed chimera (MC) recipients, which were comparable with the GVL/GVHD rates observed after the transfer of naive donor lymphocyte infusion (DLI). Upon early transfer, GVL effects were more pronounced with ETCs but at the expense of significant GVHD. The degree of GVHD was most severe in MCs after transfer of ETCs that had been in vitro primed either on nonpulsed recipient-derived APCs or with donor-derived APCs.

  5. An ADAMTSL2 founder mutation causes Musladin-Lueke Syndrome, a heritable disorder of beagle dogs, featuring stiff skin and joint contractures.

    Directory of Open Access Journals (Sweden)

    Hannah L Bader

    2010-09-01

    Full Text Available Musladin-Lueke Syndrome (MLS is a hereditary disorder affecting Beagle dogs that manifests with extensive fibrosis of the skin and joints. In this respect, it resembles human stiff skin syndrome and the Tight skin mouse, each of which is caused by gene defects affecting fibrillin-1, a major component of tissue microfibrils. The objective of this work was to determine the genetic basis of MLS and the molecular consequence of the identified mutation.We mapped the locus for MLS by genome-wide association to a 3.05 Mb haplotype on canine chromosome 9 (CFA9 (50.11-54.26; p(raw T; p.R221C perfectly associated with MLS (p-value=10(-12. Murine ADAMTSL2 containing the p.R221C mutation formed anomalous disulfide-bonded dimers when transiently expressed in COS-1, HEK293F and CHO cells, and was present in the medium of these cells at lower levels than wild-type ADAMTSL2 expressed in parallel.The genetic basis of MLS is a founder mutation in ADAMTSL2, previously shown to interact with latent TGF-β binding protein, which binds fibrillin-1. The molecular effect of the founder mutation on ADAMTSL2 is formation of disulfide-bonded dimers. Although caused by a distinct mutation, and having a milder phenotype than human GD, MLS nevertheless offers a new animal model for study of GD, and for prospective insights on mechanisms and pathways of skin fibrosis and joint contractures.

  6. [The limited spectrum of pathogenic BRCA1 and BRCA2 mutations in the French Canadian breast and breast-ovarian cancer families, a founder population of Quebec, Canada].

    Science.gov (United States)

    Tonin, Patricia N

    2006-09-01

    The unique genetic demography of the French Canadian population of Quebec, Canada, has provided a means to study the contribution of BRCA1 and BRCA2, the breast-ovarian cancer susceptibility genes. Here we review BRCA1 and BRCA2 in the context of French Canadian cancer families, a well-characterized founder population known for its contributions to medical genetics. Pathogenic BRCA1 and BRCA2 mutations contribute to a significant proportion of hereditary breast and/or ovarian cancer families of French Canadian descent. BRCA1 and BRCA2 mutations have been reported in approximately 40 % of families with at least three cases of breast and/or ovarian cancer, where breast cancer diagnosis occurred before age 66 years, and where all cases occurred within first-, second- and/or third-degree relatives to index affected cases tested for mutations. The proportion of mutation-positive families was very similar to that reported in independent studies of families not selected for ethnicity. However, 84 % of mutation-positive families were accounted for by one of eight pathogenic mutations in BRCA1 (2953delGTA + C, 3875delGTCT, and 4446C --> T) and BRCA2 (2816insA, 3398delAAAAG, 6085G --> T, 6503delTT, and 8765delAG). Haplotype analyses has suggested that carriers of the most common recurring mutations share a related ancestry. This effect has been attributed to common founders in the French Canadian population of Quebec who emigrated from France in between 1608 and 1759. It is possible that novel highly penetrant cancer susceptibility genes account for a fraction of the 60 % of BRCA mutation-negative French Canadian cancer families. The continued genetic analysis and phenotypic characterization of French Canadian cancer families is warranted given the large family structure of these families are amenable for classical genome-wide linkage analysis for novel breast and ovarian cancer susceptibility genes.

  7. Strong Arcwise Connectedness

    OpenAIRE

    Espinoza, Benjamin; Gartside, Paul; Kovan-Bakan, Merve; Mamatelashvili, Ana

    2012-01-01

    A space is `n-strong arc connected' (n-sac) if for any n points in the space there is an arc in the space visiting them in order. A space is omega-strong arc connected (omega-sac) if it is n-sac for all n. We study these properties in finite graphs, regular continua, and rational continua. There are no 4-sac graphs, but there are 3-sac graphs and graphs which are 2-sac but not 3-sac. For every n there is an n-sac regular continuum, but no regular continuum is omega-sac. There is an omega-sac ...

  8. Abortion: Strong's counterexamples fail

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2009-01-01

    This paper shows that the counterexamples proposed by Strong in 2008 in the Journal of Medical Ethics to Marquis's argument against abortion fail. Strong's basic idea is that there are cases--for example, terminally ill patients--where killing an adult human being is prima facie seriously morally......'s scenarios have some valuable future or admitted that killing them is not seriously morally wrong. Finally, if "valuable future" is interpreted as referring to objective standards, one ends up with implausible and unpalatable moral claims....

  9. Strong interaction at finite temperature

    Indian Academy of Sciences (India)

    Abstract. We review two methods discussed in the literature to determine the effective parameters of strongly interacting particles as they move through a heat bath. The first one is the general method of chiral perturbation theory, which may be readily applied to this problem. The other is the method of thermal QCD sum rules ...

  10. A strong comeback

    International Nuclear Information System (INIS)

    Marier, D.

    1992-01-01

    This article presents the results of a financial rankings survey which show a strong economic activity in the independent energy industry. The topics of the article include advisor turnover, overseas banks, and the increase in public offerings. The article identifies the top project finance investors for new projects and restructurings and rankings for lenders

  11. Nukuleka as a founder colony for West Polynesian settlement : new insights from recent excavations

    International Nuclear Information System (INIS)

    Burley, D.V.; Barton, A.; Dickinson, W.R.; Connaughton, S.P.; Tache, K.

    2010-01-01

    Previous archaeological studies in the village of Nukuleka, Tongatapu, Kingdom of Tonga proposed it as a founder colony for Polynesia. Additional excavation and survey were undertaken in 2007 to evaluate this status further and to gain new insight into the nature of the occupation and its role in the subsequent peopling of west Polynesia. A review of this project and its findings are presented. Decorated ceramics of western Lapita style, the presence of tan paste ceramics foreign to Tonga, and new radiocarbon dates support Nukuleka as a site of first landfall in the interval 2850 to 2900 cal BP. The ceramic assemblage is distinct from west and central Fiji, and an independent origin for Fijian and Polynesian colonizers is argued. The settlement quickly expanded on the Nukuleka Peninsula to 20 ha or more in size, forming a central place for the eastern Lapita province in Tonga, Samoa and the Lau islands of Fiji. Nukuleka, we believe, provides insight into the cultural if not biological base from which ancestral Polynesian society emerged. (author). 35 refs., 11 figs., 3 tabs.

  12. Religion and Science in the Works of the Founder of the First Wave of Positivism

    Directory of Open Access Journals (Sweden)

    Arkadiy Korsakov

    2012-04-01

    Full Text Available This article attempts to deal with the last phase of the life and work of Auguste Conte, the founder of the philosophy of positivism. The appearance and development of this type of philosophy were conditioned by the new waves of thought which dominated European philosophy during the nineteenth century. It was believed that faith in a scientific method would guarantee the success of any kind of scientific endeavor. Conte developed his idea of a three level intellectual evolution from notions which had already been posited by Saint-Simon. According to this ideology, man begins to mature when he begins to abandon his childish and immature notions about the world, or in other words, his religious-mystical preoccupations. Eventually he becomes an adult and begins to discover a type of God in himself. But in this way, positivism itself begins to develop its own religious and mystical traits while at the same time conducting a fierce battle with a religious conception of the world. These ideas come especially to the fore in the later works of Conte. In these works, the philosopher stipulates that although sociology is at the absolute pinnacle of the sciences, there is yet another level, still higher than all these - and that is the domain of the so-called religion of mankind

  13. Ocular biometry and determinants of refractive error in a founder population of European ancestry.

    Science.gov (United States)

    Hilkert, Sarah M; Parness-Yossifon, Reut; Mets-Halgrimson, Rebecca; Mets, Marilyn B

    2018-01-01

    The prevalence of myopia is increasing worldwide. Previous studies have found a positive association between myopia, education, and near activities, while others have noted a negative association with outdoor exposure. This study reports refractive error and biometry in a founder population of European ancestry, the Hutterites, and discusses risk factors contributing to myopia. Cross-sectional study, including complete eye exams with retinoscopy and biometry. 939 study participants, ages 6 to 89, were examined. Females were significantly more myopic than males (SE -0.87 ± 2.07 and -0.40 ± 1.49 in females and males, respectively, p refractive error among the Hutterites. As a genetically isolated population with a communal lifestyle, the Hutterites present a unique opportunity to study risk factors for myopia. Hutterite females are more myopic than males, a finding which has only been reported in a few other populations. Hutterite children complete compulsory education through the 8th grade, after which women and men assume gender-specific occupational tasks. Men often work outside on the farm, while women engage in more domestic activities inside. These occupational differences likely contribute to the increased myopia comparing females to males, and their uniform lifestyle reduces the impact of potential confounding factors, such as education and income. The Hutterites are more myopic than most other North American and European populations. Greater time spent doing near work and less time spent outdoors likely explain the increased myopia comparing females to males.

  14. Genome-wide association study of pre-harvest sprouting resistance in Chinese wheat founder parents

    Directory of Open Access Journals (Sweden)

    Yu Lin

    2017-07-01

    Full Text Available Abstract Pre-harvest sprouting (PHS is a major abiotic factor affecting grain weight and quality, and is caused by an early break in seed dormancy. Association mapping (AM is used to detect correlations between phenotypes and genotypes based on linkage disequilibrium (LD in wheat breeding programs. We evaluated seed dormancy in 80 Chinese wheat founder parents in five environments and performed a genome-wide association study using 6,057 markers, including 93 simple sequence repeat (SSR, 1,472 diversity array technology (DArT, and 4,492 single nucleotide polymorphism (SNP markers. The general linear model (GLM and the mixed linear model (MLM were used in this study, and two significant markers (tPt-7980 and wPt-6457 were identified. Both markers were located on Chromosome 1B, with wPt-6457 having been identified in a previously reported chromosomal position. The significantly associated loci contain essential information for cloning genes related to resistance to PHS and can be used in wheat breeding programs.

  15. [THE FOUNDERS OF FIRST CHAIRS OF HISTORY OF MEDICINE AND SOCIAL HYGIENE IN THE USSR].

    Science.gov (United States)

    Gorelova, L E; Kasimovskaia, N A

    2015-01-01

    The USSR academy of medical sciences was organized in 1944. At the same year, the institute of health care organization, medical statistics and social hygiene was included in its structure. Before the institute global tasks in area of research and pedagogic activities were stated. They were implemented in accordance with actual national demands. The institute became a leading research center of studying problems of population health, social hygiene, organization and management of health care and history of medicine. In 2003, the institute was renamed in the The RAMS national research institute of public health, and in 2013 was handed over the Federal agency of research organizations (FANO) of Russia. The directors of the institute were well-known scientists in the field of social hygiene health care organization and history of medicine. They made a significant input into development of medical education, combining scientific, managerial and pedagogic activities. The founders of the first chairs of history of medicine and social hygiene were the directors of the institute I.D. Strashun and N.A. Semashko.

  16. Willet M. Hays, great benefactor to plant breeding and the founder of our association.

    Science.gov (United States)

    Troyer, A F; Stoehr, H

    2003-01-01

    Willet M. Hays was a great benefactor to plant breeding and the founder of the American Genetic Association (AGA). We commemorate the AGA's centennial. We mined university archives, U.S. Department of Agriculture (USDA) yearbooks, plant breeding textbooks, scientific periodicals, and descendants for information. Willet Hays first recognized the individual plant as the unit of selection and started systematic pure-line selection and progeny tests in 1888. He developed useful plant breeding methods. He selected superior flax (Linum usitatissimum L.), wheat (Triticum vulgare L.), corn (Zea mays L.), barley (Hordeum vulgare L.), and oat (Avena sativa L.) varieties, and discovered Grimm alfalfa (Medicago sativa L.); all became commercially important. He initiated branch stations for better performance testing. Willet Hays befriended colleagues in other universities, in federal stations, in a London conference, and in Europe. He gathered and spread the scientific plant breeding gospel. He also improved rural roads and initiated animal breeding records and agricultural economics records. He started the AGA in 1903, serving as secretary for 10 years. He became assistant secretary of agriculture in 1904. He introduced the project system for agricultural research. He authored or coauthored the Nelson Amendment, the Smith-Lever Act, the Smith-Hughes Act, and the protocol leading to the United Nations Food and Agriculture Organization-all involved teaching agricultural practices that improved the world.

  17. Founders Energy Ltd. 1998 annual report : fiscally prudent, value driven balanced growth strategy

    International Nuclear Information System (INIS)

    1999-01-01

    Founders Energy Ltd is a growth-oriented junior resource company engaged in the acquisition and development of oil and natural gas properties in Alberta, British Columbia and Saskatchewan. The annual review provides details of the company's operations and relevant financial performance during the 1998 fiscal year. In brief, the company realized significant increases in production and reserves, top quartile findings and development costs. It reported significant increases in leverage to natural gas through exploration success at Pouce Coupe and the acquisition of Opal Energy Inc.. It established new core areas in west-central Alberta, Peace River Arch and west-central Saskatchewan. It achieved a better balanced risk profile through geographical diversification and better balance to exploration and development. It increased undeveloped land area to 160,268 net acres and added 11.5 million barrels of established reserves at a finding cost of $ 6.28 per barrel. Financial highlights include increased gross revenue, increased net income per share, and increased shareholders' equity. tabs., figs

  18. Characterization of a novel founder MSH6 mutation causing Lynch syndrome in the French Canadian population.

    Science.gov (United States)

    Castellsagué, E; Liu, J; Volenik, A; Giroux, S; Gagné, R; Maranda, B; Roussel-Jobin, A; Latreille, J; Laframboise, R; Palma, L; Kasprzak, L; Marcus, V A; Breguet, M; Nolet, S; El-Haffaf, Z; Australie, K; Gologan, A; Aleynikova, O; Oros-Klein, K; Greenwood, C; Mes-Masson, A M; Provencher, D; Tischkowitz, M; Chong, G; Rousseau, F; Foulkes, W D

    2015-06-01

    We identified an MSH6 mutation (c.10C>T, p.Gln4*) causing Lynch syndrome (LS) in 11 French Canadian (FC) families from the Canadian province of Quebec. We aimed to investigate the molecular and clinical implications of this mutation among FC carriers and to assess its putative founder origin. We studied 11 probands and 27 family members. Additionally 6433 newborns, 187 colorectal cancer (CRC) cases, 381 endometrial cancer (EC) cases and 179 additional controls, all of them from Quebec, were used. Found in approximately 1 of 400 newborns, the mutation is one of the most common LS mutations described. We have found that this mutation confers a greater risk for EC than for CRC, both in the 11 studied families and in the unselected cases: EC [odds ratio (OR) = 7.5, p French settlers. Application of the results of this study could significantly improve the molecular testing and clinical management of LS families in Quebec. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Gynecologic malignancies in Ashkenazi families with the MSH2 A636P founder mutation.

    Science.gov (United States)

    Lavie, Ofer; Gruber, Stephen B; Lejbkowicz, Flavio; Dishon, Sara; Rennert, Gad

    2008-08-01

    A founder mutation A636P in the MSH2 gene was found to be related to hereditary nonpolyposis colorectal cancer in Ashkenazi Jews. Although the incidence of colorectal cancer in carriers is relatively well established, the frequency of other tumors is less clear. We studied a consecutive series of 19 carrier families that were cared for by the Clalit Health Studies National Familial Cancer Consultation Service, most of whom were identified through a population-based case-control study of colorectal cancer in northern Israel. Gynecologic cancers, 88% of which (28 cases) were endometrial cancers, were diagnosed in 78.9% of the carrier families and in 26.2% of the women who were at risk, with a mean age at diagnosis of 51.2 years. Forty-six percent of the women with endometrial cancer reported at least 1 other primary tumor. Genetic counseling and testing for the MSH2 A636P mutation is indicated for Ashkenazi Jewish women with an endometrial cancer, especially if the cancer is detected before the age of 70 years in women with a personal or family history of colorectal cancer.

  20. Marie Sklodowska-Curie: teacher, mentor, research center founder, and '' la Patronne ''

    International Nuclear Information System (INIS)

    Hoffman, D.C.

    2011-01-01

    This year (2011) marks the 100 th Anniversary of the award of the Nobel Prize in Chemistry to Marie Sklodowska-Curie for her discoveries of radium and polonium and her studies of their properties. The United Nations has proclaimed 2011 as the '' International Year of Chemistry '', partly in recognition of this 100 th anniversary. A resolution of the Sejm of the Republic of Poland has also established 2011 as the Year of Maria Sklodowska-Curie. Marie Curie has been celebrated this year by a host of prestigious societies and in many countries all around the world for winning Nobel Prizes in both Physics (1903), for the discovery of radioactivity together with husband Pierre Curie and Henri Becquerel, and Chemistry (1911). She was the first woman to win Nobel Prizes in both Physics and Chemistry and the only one to date to win prizes in both physics and chemistry. Also remarkable was that after Pierre Curie's tragic and untimely death in 1906, she was put in charge of his lectures and laboratory, thus marking the first time in France that a woman occupied such a prestigious academic position, and opening the way for other women to follow. The current article will focus on some of the other notable accomplishments of Marie Curie that are not as commonly recognized, including her organizational and persuasive abilities, and her unique contributions as a teacher, mentor, research center founder, and laboratory '' la Patronne ''. (author)

  1. [On the founders of the Institute of Mathematics and Physics, University of Bahia].

    Science.gov (United States)

    Dias, A L

    The reduced number of female students of mathematics at the University of Bahia School of Philosophy (Faculdade de Filosofia, Universidade da Bahia - FF/UBa) is quite surprising. To date, they are concentrated in areas traditionally viewed as feminine whereas men predominate in the mathematical fields. I have examined interview data from a few women who graduated in mathematics and went on to teach at the University of Bahia School of Mathematics (Faculdade de Filosofia - FF) and at the Institute of Mathematics and Physics (Instituto de Matemática e Física - IMF), where they were soon to outnumber men and constitute the majority of the mathematics teaching staff. In this study, I have investigated the course of their careers over time: from their early student days, through their time as teaching assistants and professors, and finally as founders of the Institute of Mathematics and Physics, in 1960. Special reference is made to Martha Maria de Souza Dantas, organizer of the I Brazilian Conference on Mathematics Teaching, an event which has provided the groundwork for what was to become the Institute (IMF); and to Arlete Cerqueira Lima, the mastermind behind its creation.

  2. Brief report on a systematic review of youth violence prevention through media campaigns: Does the limited yield of strong evidence imply methodological challenges or absence of effect?

    Science.gov (United States)

    Cassidy, Tali; Bowman, Brett; McGrath, Chloe; Matzopoulos, Richard

    2016-10-01

    We present a brief report on a systematic review which identified, assessed and synthesized the existing evidence of the effectiveness of media campaigns in reducing youth violence. Search strategies made use of terms for youth, violence and a range of terms relating to the intervention. An array of academic databases and websites were searched. Although media campaigns to reduce violence are widespread, only six studies met the inclusion criteria. There is little strong evidence to support a direct link between media campaigns and a reduction in youth violence. Several studies measure proxies for violence such as empathy or opinions related to violence, but the link between these measures and violence perpetration is unclear. Nonetheless, some evidence suggests that a targeted and context-specific campaign, especially when combined with other measures, can reduce violence. However, such campaigns are less cost-effective to replicate over large populations than generalised campaigns. It is unclear whether the paucity of evidence represents a null effect or methodological challenges with evaluating media campaigns. Future studies need to be carefully planned to accommodate for methodological difficulties as well as to identify the specific elements of campaigns that work, especially in lower and middle income countries. Copyright © 2016 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

  3. [Effects of irrigation scheme on the grain glutenin macropolymer's size distribution and the grain quality of winter wheat with strong gluten].

    Science.gov (United States)

    Zhou, Xiao-Yan; Jia, Dian-Yong; Dai, Xing-Long; He, Ming-Rong

    2013-09-01

    Taking two winter wheat (Triticum aestivum L.) cultivars (Gaocheng 8901 and Jimai 20) with high quality strong gluten as test materials, a 2-year field experiment was conducted to study the grain glutenin macropolymer (GMP)'s content and size distribution, grain quality, and grain yield under effects of different irrigation schemes. The schemes included no irrigation in whole growth period (W0), irrigation once at jointing stage (W1), irrigation two times at wintering and jointing stages (W2), respectively, and irrigation three times at wintering, jointing, and filling stages (W3), respectively, with the irrigation amount in each time being 675 m3 x hm(-2). Among the test irrigation schemes, W2 had the best effects on the dough development time, dough stability time, loaf volume, grain yield, GMP content, weighted average surface area of particle D(3,2), weighted average volume of particle D(4,3), and volume percent and surface area percent of particle size >100 microm of the two cultivars. The dough development time, dough stability time, and loaf volume were negatively correlated with the volume percent of GMP particle size 100 microm, D(3,2), and D(4,3). It was suggested that both water deficit and water excess had detrimental effects on the grain yield and grain quality, and irrigation level could affect the wheat grain quality through altering GMP particle size distribution.

  4. 13 February 2012 - World Economic Forum Founder and Executive Chairman K. Schwab and Chairperson and Co-Founder Schwab Foundation for Social Entrepreneurship H. Schwab (Mrs)in the ATLAS experimental area at LHC Point 1 with Collaboration Former Spokesperson P. Jenni; signing the guest book with CERN Director-General R. Heuer and Head of International Relations F. Pauss.

    CERN Multimedia

    Jean-Claude Gadmer

    2012-01-01

    13 February 2012 - World Economic Forum Founder and Executive Chairman K. Schwab and Chairperson and Co-Founder Schwab Foundation for Social Entrepreneurship H. Schwab (Mrs)in the ATLAS experimental area at LHC Point 1 with Collaboration Former Spokesperson P. Jenni; signing the guest book with CERN Director-General R. Heuer and Head of International Relations F. Pauss.

  5. Strong Electroweak Symmetry Breaking

    CERN Document Server

    Grinstein, Benjamin

    2011-01-01

    Models of spontaneous breaking of electroweak symmetry by a strong interaction do not have fine tuning/hierarchy problem. They are conceptually elegant and use the only mechanism of spontaneous breaking of a gauge symmetry that is known to occur in nature. The simplest model, minimal technicolor with extended technicolor interactions, is appealing because one can calculate by scaling up from QCD. But it is ruled out on many counts: inappropriately low quark and lepton masses (or excessive FCNC), bad electroweak data fits, light scalar and vector states, etc. However, nature may not choose the minimal model and then we are stuck: except possibly through lattice simulations, we are unable to compute and test the models. In the LHC era it therefore makes sense to abandon specific models (of strong EW breaking) and concentrate on generic features that may indicate discovery. The Technicolor Straw Man is not a model but a parametrized search strategy inspired by a remarkable generic feature of walking technicolor,...

  6. Genetic consequences of a century of protection: serial founder events and survival of the little spotted kiwi (Apteryx owenii)

    OpenAIRE

    Ramstad, Kristina M.; Colbourne, Rogan M.; Robertson, Hugh A.; Allendorf, Fred W.; Daugherty, Charles H.

    2013-01-01

    We present the outcome of a century of post-bottleneck isolation of a long-lived species, the little spotted kiwi (Apteryx owenii, LSK) and demonstrate that profound genetic consequences can result from protecting few individuals in isolation. LSK were saved from extinction by translocation of five birds from South Island, New Zealand to Kapiti Island 100 years ago. The Kapiti population now numbers some 1200 birds and provides founders for new populations. We used 15 microsatellite loci to c...

  7. Gerald J. Marks, M.D., FACS (1925-), founder of the Society of American Gastrointestinal Endoscopic Surgeons (SAGES).

    Science.gov (United States)

    Yeo, Theresa P; Cowan, Scott W; Yeo, Charles J

    2018-03-01

    This historical vignette describes the professional career of Gerald J. Marks, the founder of the Society of American Gastrointestinal and Endoscopic Surgeons and the International Federation of Societies of Endoscopic Surgeons. Dr. Marks is also the founding Associate Editor of Surgical Endoscopy, which celebrated its 30th anniversary in 2017. Dr. Marks is a renowned colorectal surgeon, an accomplished watercolor artist, and a fascinating personality.

  8. KT seminar on entrepreneurship | "From CERN engineer to company founder: my journey" by Julio Lucas | 26 September

    CERN Multimedia

    2016-01-01

    Europe needs its economy to be boosted by the ideas of its most talented scientists and engineers. One of the best ways in which these ideas may contribute to society is by creating a new business. In this Knowledge Transfer seminar, Julio Lucas, Technical Director and co-founder of Elytt Energy and former CERN engineer gives a personal view on how to make your first steps in entrepreneurship.    

  9. Narrowband UVB treatment is highly effective and causes a strong reduction in the use of steroid and other creams in psoriasis patients in clinical practice.

    Directory of Open Access Journals (Sweden)

    John Foerster

    Full Text Available Narrowband NB-UVB phototherapy (NB-UVB is an effective treatment for psoriasis, as demonstrated by clinical trials. However, due to required infrastructure and need for treatment attendance opinions on the value of offering this treatment in routine practice vary. AIMS: To provide high quality large-scale and long-term data on the efficacy of NB-UVB for psoriasis under real-world conditions in order to assist in management decisions.The following resources were employed: (1 complete and prospectively recorded prescription drug records for a population of 420,000 marked by low demographic mobility, (2 prospectively recorded clinical treatment outcomes for all NB-UVB treatment episodes occurring in the local population; (3 complete dermatology electronic treatment records of all psoriasis patients, allowing cross-validation of diagnoses and treatment records. Using these data sets, we analysed all first-ever initial NB-UVB treatment episodes occurring over 79 months (n = 1749 for both clinical outcomes and the effect of NB-UVB on the use of topical treatments for psoriasis.Around 75% of patients both achieved a status of "clear/minimal disease" and used fewer topical treatments. NB-UVB treatment led to a strong reduction for both steroid creams (25% and psoriasis-specific topicals, e.g. vitamin-D products (30% during the 12-month period following NB-UVB treatment. The effects measured were specific as no effect of NB-UVB was noted on drug prescriptions unrelated to psoriasis. Results were independent of individuals administering and/or scoring treatment, as they were highly similar between four geographically separate locations.NB-UVB treatment is highly effective and leads to a remarkable reduction in the need for topical cream treatments for a period of at least 12 months.

  10. Plasmons in strong superconductors

    International Nuclear Information System (INIS)

    Baldo, M.; Ducoin, C.

    2011-01-01

    We present a study of the possible plasmon excitations that can occur in systems where strong superconductivity is present. In these systems the plasmon energy is comparable to or smaller than the pairing gap. As a prototype of these systems we consider the proton component of Neutron Star matter just below the crust when electron screening is not taken into account. For the realistic case we consider in detail the different aspects of the elementary excitations when the proton, electron components are considered within the Random-Phase Approximation generalized to the superfluid case, while the influence of the neutron component is considered only at qualitative level. Electron screening plays a major role in modifying the proton spectrum and spectral function. At the same time the electron plasmon is strongly modified and damped by the indirect coupling with the superfluid proton component, even at moderately low values of the gap. The excitation spectrum shows the interplay of the different components and their relevance for each excitation modes. The results are relevant for neutrino physics and thermodynamical processes in neutron stars. If electron screening is neglected, the spectral properties of the proton component show some resemblance with the physical situation in high-T c superconductors, and we briefly discuss similarities and differences in this connection. In a general prospect, the results of the study emphasize the role of Coulomb interaction in strong superconductors.

  11. Probiotic Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 exhibit strong antifungal effects against vulvovaginal candidiasis-causing Candida glabrata isolates.

    Science.gov (United States)

    Chew, S Y; Cheah, Y K; Seow, H F; Sandai, D; Than, L T L

    2015-05-01

    This study investigates the antagonistic effects of the probiotic strains Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 against vulvovaginal candidiasis (VVC)-causing Candida glabrata. Growth inhibitory activities of Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains against C. glabrata were demonstrated using a spot overlay assay and a plate-based microtitre assay. In addition, these probiotic lactobacilli strains also exhibited potent candidacidal activity against C. glabrata, as demonstrated by a LIVE/DEAD yeast viability assay performed using confocal laser scanning microscopy. The metabolic activities of all C. glabrata strains were completely shut down in response to the challenges by the probiotic lactobacilli strains. In addition, both probiotic lactobacilli strains exhibited strong autoaggregation and coaggregation phenotypes in the presence of C. glabrata, which indicate that these lactobacilli strains may exert their probiotic effects through the formation of aggregates and, thus the consequent prevention of colonization by C. glabrata. Probiotic Lact. rhamnosus GR-1 and Lact. reuteri RC-14 strains exhibited potent antagonistic activities against all of the tested C. glabrata strains. These lactobacilli exhibited antifungal effects, including those attributed to their aggregation abilities, and their presence caused the cessation of growth and eventual cell death of C. glabrata. This is the first study to report on the antagonistic effects of these probiotic lactobacilli strains against the non-Candida albicans Candida (NCAC) species C. glabrata. © 2015 The Authors published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

  12. The degradation of strong basic anion exchange resins and mixed-bed ion-exchange resins: Effect of degradation products on radionuclide speciation

    International Nuclear Information System (INIS)

    Loon, L.R. van; Hummel, W.

    1999-01-01

    The most important water-soluble products of the radiolytic degradation of anion exchange resins in a cementitious environment are ammonia and methylamines. These ligands do not form complexes with most radionuclides. Exceptions are Ni, Ag, and Pd, which form strong complexes with amines. Other degradation products of anion and mixed-bed ion-exchange resins are of no importance concerning the complexation of trivalent radionuclides. This is shown indirectly by adsorption experiments: The degradation products do not have a significant effect on the adsorption of Eu(III) on calcite. The effect of ammonia and methylamines on the complexation of Ni, Ag, and Pd is investigated by chemical modeling. For Ni and Ag, rather reliable predictions can be made using available thermodynamic data. In the case of Pd, large uncertainties are encountered due to unreliable data and gaps in the set of important species. The system Pd(II)-ammonia-water is explored in detail. Predominant species are inferred by chemical analogy, and their thermodynamic data are estimated. The uncertainty in these estimated and measured but unreliable data is bound by qualitative and quantitative chemical reasoning

  13. Mapping one strong 'Ohana: using network analysis and GIS to enhance the effectiveness of a statewide coalition to prevent child abuse and neglect.

    Science.gov (United States)

    Cardazone, Gina; U Sy, Angela; Chik, Ivan; Corlew, Laura Kate

    2014-06-01

    Network analysis and GIS enable the presentation of meaningful data about organizational relationships and community characteristics, respectively. Together, these tools can provide a concrete representation of the ecological context in which coalitions operate, and may help coalitions identify opportunities for growth and enhanced effectiveness. This study uses network analysis and GIS mapping as part of an evaluation of the One Strong 'Ohana (OSO) campaign. The OSO campaign was launched in 2012 via a partnership between the Hawai'i Children's Trust Fund (HCTF) and the Joyful Heart Foundation. The OSO campaign uses a collaborative approach aimed at increasing public awareness of child maltreatment and protective factors that can prevent maltreatment, as well as enhancing the effectiveness of the HCTF Coalition. This study focuses on three elements of the OSO campaign evaluation: (1) Network analysis exploring the relationships between 24 active Coalition member organizations, (2) GIS mapping of responses to a randomized statewide phone survey (n = 1,450) assessing awareness of factors contributing to child maltreatment, and (3) Combined GIS maps and network data, illustrating opportunities for geographically-targeted coalition building and public awareness activities.

  14. EBSD Study on the Effect of a Strong Axial Magnetic Field on the Microstructure and Crystallography of Al-Ni Alloys During Solidification

    Science.gov (United States)

    Li, Xi; Fautrelle, Yves; Gagnoud, Annie; Moreau, Rene; Du, Dafan; Ren, Zhongming; Lu, Xionggang

    2016-03-01

    The effect of a strong magnetic field on the microstructure and crystallography of the primary and eutectic Al3Ni phases in Al-Ni alloys was investigated by using EBSD. The results show that the magnetic field significantly affected the microstructures and crystallography during both volume and directional solidification. As a result, the Al3Ni primary phases were aligned with the crystal direction along the magnetic field and formed a layer-like structure. The magnetic field intensity, solidification temperature, growth speed, and alloy composition played important roles during the alignment process of the Al3Ni primary phase. Indeed, the alignment degree increased with the magnetic field and the solidification temperature during normal solidification. Moreover, the effect of the magnetic field on the crystallography of the Al-Al3Ni eutectic in the Al-Ni alloys was also studied. The applied magnetic field modified the orientation of the preferred growth direction of the Al3Ni eutectic fiber and the crystallographic orientation relationship of the Al-Al3Ni eutectic. The orientation of the preferred growth direction of the Al3Ni eutectic fiber depended mainly on the solidification direction and the alignment of the Al3Ni primary phase. Furthermore, a method for controlling the crystallization process by adjusting the angle between the solidification direction and the magnetic field was proposed.

  15. Don't Think, Just Feel the Music: Individuals with Strong Pavlovian-to-Instrumental Transfer Effects Rely Less on Model-based Reinforcement Learning.

    Science.gov (United States)

    Sebold, Miriam; Schad, Daniel J; Nebe, Stephan; Garbusow, Maria; Jünger, Elisabeth; Kroemer, Nils B; Kathmann, Norbert; Zimmermann, Ulrich S; Smolka, Michael N; Rapp, Michael A; Heinz, Andreas; Huys, Quentin J M

    2016-07-01

    Behavioral choice can be characterized along two axes. One axis distinguishes reflexive, model-free systems that slowly accumulate values through experience and a model-based system that uses knowledge to reason prospectively. The second axis distinguishes Pavlovian valuation of stimuli from instrumental valuation of actions or stimulus-action pairs. This results in four values and many possible interactions between them, with important consequences for accounts of individual variation. We here explored whether individual variation along one axis was related to individual variation along the other. Specifically, we asked whether individuals' balance between model-based and model-free learning was related to their tendency to show Pavlovian interferences with instrumental decisions. In two independent samples with a total of 243 participants, Pavlovian-instrumental transfer effects were negatively correlated with the strength of model-based reasoning in a two-step task. This suggests a potential common underlying substrate predisposing individuals to both have strong Pavlovian interference and be less model-based and provides a framework within which to interpret the observation of both effects in addiction.

  16. The initiation of lateral roots in the primary roots of maize (Zea mays L.) implies a reactivation of cell proliferation in a group of founder pericycle cells.

    Science.gov (United States)

    Alarcón, M Victoria; Lloret, Pedro G; Martín-Partido, Gervasio; Salguero, Julio

    2016-03-15

    The initiation of lateral roots (LRs) has generally been viewed as a reactivation of proliferative activity in pericycle cells that are committed to initiate primordia. However, it is also possible that pericycle founder cells that initiate LRs never cease proliferative activity but rather are displaced to the most distal root zones while undertaking successive stages of LR initiation. In this study, we tested these two alternative hypotheses by examining the incorporation of 5-bromo-2'-deoxyuridine (BrdU) into the DNA of meristematic root cells of Zea mays. According to the values for the length of the cell cycle and values for cell displacement along the maize root, our results strongly suggest that pericycle cells that initiate LR primordia ceased proliferative activity upon exiting the meristematic zone. This finding is supported by the existence of a root zone between 4 and 20mm from the root cap junction, in which neither mitotic cells nor labelled nuclei were observed in phloem pericycle cells. Copyright © 2016 Elsevier GmbH. All rights reserved.

  17. Founder effect in 20 Afrikaner kindreds with pse·udoxanthoma ...

    African Journals Online (AJOL)

    1991-01-05

    , Maastricht and Ommen respectively. At present, heterozygous carriers of PXE cannot be identified clinically or through the use of sophisticated biomolecular techniques. However, investigations are under way using elastin.

  18. Founder event and its effect on genetic variation in translocated populations of noble crayfish (Astacus astacus)

    Czech Academy of Sciences Publication Activity Database

    Bláha, M.; Žurovcová, Martina; Kouba, A.; Policar, T.; Kozák, P.

    2016-01-01

    Roč. 57, č. 1 (2016), s. 99-106 ISSN 1234-1983 Grant - others:European Fund(CZ) CZ.1.07/2.3.00/30.0049; European Fund(CZ) CZ1.05/2.1.00/01.0024; GA ČR(CZ) GAP505/12/0545 Institutional support: RVO:60077344 Keywords : bottleneck * conservation * homozygote excess Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 1.655, year: 2016 http://link.springer.com/article/10.1007%2Fs13353-015-0296-3

  19. Contribution of CYP1B1 mutations and founder effect to primary congenital glaucoma in Mexico.

    Science.gov (United States)

    Zenteno, Juan Carlos; Hernandez-Merino, Elena; Mejia-Lopez, Herlinda; Matías-Florentino, Margarita; Michel, Norma; Elizondo-Olascoaga, Celia; Korder-Ortega, Vincent; Casab-Rueda, Homero; Garcia-Ortiz, Jose Elias

    2008-01-01

    The frequency of primary congenital glaucoma (PCG)-causing CYP1B1 mutations varies importantly among distinct populations, ranging from 20% in Indonesians and Japanese to about 100% among the Saudi Arabians and Slovakian Gypsies. Thus, the molecular characterization of large groups of PCG from different ethnic backgrounds is important to establish the actual CYP1B1 contribution in specific populations. In this work, the molecular analysis of the CYP1B1 gene in a group of Mexican PCG patients is reported. Thirty unrelated Mexican patients fulfilling the clinical criteria for PCG were included. Two cases were familial and with proven consanguinity, originating from distinct regions of the country. Polymerase chain reaction amplification and direct automated sequencing of the CYP1B1 coding region was performed in each participating subject. An identical pathogenic CYP1B1 mutation was demonstrated in 2 unrelated PCG subjects. The mutation consisted of a homozygous G to A transition at nucleotide position 1505 in exon 3, which predicted a substitution of glutamic acid for lysine at residue 387 of the protein (E387K). In the remaining 28 PCG subjects, no deleterious mutations were identified. Both subjects with the E387K mutation shared a same haplotype for 5 CYP1B1 intragenic single nucleotide polymorphisms, indicating a common origin of the allele. Mexican patients with PCG are rarely (less than 10%) due to CYP1B1 mutations. Available data indicate that most of the non-Brazilian Latin American PCG patients investigated to date are not due to CYP1B1 defects. Populations with low incidence of CYP1B1 mutations are appropriate candidates for the identification of novel PCG-causing genes.

  20. Seasonal climate manipulations have only minor effects on litter decomposition rates and N dynamics but strong effects on litter P dynamics of sub-arctic bog species.

    NARCIS (Netherlands)

    Aerts, R.; Callaghan, T.V.; Dorrepaal, E.; van Logtestijn, R.S.P; Cornelissen, J.H.C.

    2012-01-01

    Litter decomposition and nutrient mineralization in high-latitude peatlands are constrained by low temperatures. So far, little is known about the effects of seasonal components of climate change (higher spring and summer temperatures, more snow which leads to higher winter soil temperatures) on

  1. Age and Influenza-Specific Pre-Vaccination Antibodies Strongly Affect Influenza Vaccine Responses in the Icelandic Population whereas Disease and Medication Have Small Effects

    Science.gov (United States)

    Olafsdottir, Thorunn A.; Alexandersson, Kristjan F.; Sveinbjornsson, Gardar; Lapini, Giulia; Palladino, Laura; Montomoli, Emanuele; Del Giudice, Giuseppe; Gudbjartsson, Daniel F.; Jonsdottir, Ingileif

    2018-01-01

    Influenza vaccination remains the best strategy for the prevention of influenza virus-related disease and reduction of disease severity and mortality. However, there is large individual variation in influenza vaccine responses. In this study, we investigated the effects of gender, age, underlying diseases, and medication on vaccine responses in 1,852 Icelanders of broad age range who received trivalent inactivated influenza virus vaccination in 2012, 2013, or 2015. Hemagglutination inhibition (HAI) and microneutralization (MN) titers were measured in pre- and post-vaccination sera. Of the variables tested, the strongest association was with level of pre-vaccination titer that explained a major part of the variance observed in post-vaccination titers, ranging from 19 to 29%, and from 7 to 21% in fold change (FC), depending on the strain and serological (HAI or MN) analysis performed. Thus, increasing pre-vaccination titer associated with decreasing FC (P = 1.1 × 10−99–8.6 × 10−30) and increasing post-vaccination titer (P = 2.1 × 10−159–1.1 × 10−123). Questionnaires completed by 87% of the participants revealed that post-vaccination HAI titer showed association with repeated previous influenza vaccinations. Gender had no effect on vaccine response whereas age had a strong effect and explained 1.6–3.1% of HAI post-vaccination titer variance and 3.1% of H1N1 MN titer variance. Vaccine response, both fold increase and seroprotection rate (percentage of individuals reaching HAI ≥ 40 or MN ≥ 20), was higher in vaccinees ≤37 years of age (YoA) than all other age groups. Furthermore, a reduction was observed in the H1N1 MN titer in people ≥63 YoA, demonstrating a decreased neutralizing functionality of vaccine-induced antibodies at older age. We tested the effects of underlying autoimmune diseases, asthma and allergic diseases and did not observe significant associations with vaccine responses. Intake of immune

  2. Age and Influenza-Specific Pre-Vaccination Antibodies Strongly Affect Influenza Vaccine Responses in the Icelandic Population whereas Disease and Medication Have Small Effects

    Directory of Open Access Journals (Sweden)

    Thorunn A. Olafsdottir

    2018-01-01

    Full Text Available Influenza vaccination remains the best strategy for the prevention of influenza virus-related disease and reduction of disease severity and mortality. However, there is large individual variation in influenza vaccine responses. In this study, we investigated the effects of gender, age, underlying diseases, and medication on vaccine responses in 1,852 Icelanders of broad age range who received trivalent inactivated influenza virus vaccination in 2012, 2013, or 2015. Hemagglutination inhibition (HAI and microneutralization (MN titers were measured in pre- and post-vaccination sera. Of the variables tested, the strongest association was with level of pre-vaccination titer that explained a major part of the variance observed in post-vaccination titers, ranging from 19 to 29%, and from 7 to 21% in fold change (FC, depending on the strain and serological (HAI or MN analysis performed. Thus, increasing pre-vaccination titer associated with decreasing FC (P = 1.1 × 10−99–8.6 × 10−30 and increasing post-vaccination titer (P = 2.1 × 10−159–1.1 × 10−123. Questionnaires completed by 87% of the participants revealed that post-vaccination HAI titer showed association with repeated previous influenza vaccinations. Gender had no effect on vaccine response whereas age had a strong effect and explained 1.6–3.1% of HAI post-vaccination titer variance and 3.1% of H1N1 MN titer variance. Vaccine response, both fold increase and seroprotection rate (percentage of individuals reaching HAI ≥ 40 or MN ≥ 20, was higher in vaccinees ≤37 years of age (YoA than all other age groups. Furthermore, a reduction was observed in the H1N1 MN titer in people ≥63 YoA, demonstrating a decreased neutralizing functionality of vaccine-induced antibodies at older age. We tested the effects of underlying autoimmune diseases, asthma and allergic diseases and did not observe significant associations with vaccine responses. Intake

  3. Identification of Unequally Represented Founder Viruses Among Tissues in Very Early SIV Rectal Transmission

    Directory of Open Access Journals (Sweden)

    Jian Chen

    2018-03-01

    Full Text Available Characterizing the transmitted/founder (T/F viruses of multi-variant SIV infection may shed new light on the understanding of mucosal transmission. We intrarectally inoculated six Chinese rhesus macaques with a single high dose of SIVmac251 (3.1 × 104 TCID50 and obtained 985 full-length env sequences from multiple tissues at 6 and 10 days post-infection by single genome amplification (SGA. All 6 monkeys were infected with a range of 2 to 8 T/F viruses and the dominant variants from the inoculum were still dominant in different tissues from each monkey. Interestingly, our data showed that a cluster of rare T/F viruses was unequally represented in different tissues. This cluster of rare T/F viruses phylogenetically related to the non-dominant SIV variants in the inoculum and was not detected in any rectum tissues, but could be identified in the descending colon, jejunum, spleen, or plasma. In 2 out of 6 macaques, identical SIVmac251 variants belonging to this cluster were detected simultaneously in descending colon/jejunum and the inoculum. We also demonstrated that the average CG dinucleotide frequency of these rare T/F viruses found in tissues, as well as non-dominant variants in the inoculum, was significantly higher than the dominant T/F viruses in tissues and the inoculum. Collectively, these findings suggest that descending colon/jejunum might be more susceptible than rectum to SIV in the very early phase of infection. And host CG suppression, which was previously shown to inhibit HIV replication in vitro, may also contribute to the bottleneck selection during in vivo transmission.

  4. Master John of Arderne (1307-1380): a founder of modern surgery.

    Science.gov (United States)

    Pearn, John

    2012-01-01

    John of Arderne (1307-1380) was one founder of surgery as the profession is known today. He was the first English surgeon of whom biographic details survive. Born on the Arderne Estates at Newark, England, he served as a military surgeon in France in campaigns where gunpowder was used in combat for the first time. His best-known work, the Practica (De Arte Phisicali et de Cirurgia), formed the basis of practical surgical teaching in the medical schools of medieval Europe. Biographic research of primary and secondary archives and documents. John of Arderne's surgical practice was undertaken against a background of turbulent political, military and medical events. He survived the Black Death (1347) and its cyclical recurrences. He lived through the turbulent reigns of Edward II and Edward III and practised in London in the decades preceding the simmering unrest which preceded the Peasant's Revolt of 1381. Surgical and medical practice in the late Middle Ages was enmeshed in astrological beliefs. It was greatly influenced by church doctrine of disease causation. In this paper, the known details of John of Arderne's life are placed in the perspective of these societal and professional influences. He is one of several pre-Renaissance European doctors who were the first to challenge the received medical lore of Galen and later Arabic surgeons. Writing when he was 70 years of age, John of Arderne was the first to advocate that surgeons should trust their own clinical experience 'Wele ymagynyng subtile things' rather than following the directions of others, even including those advocated by himself. © 2011 The Author. ANZ Journal of Surgery © 2011 Royal Australasian College of Surgeons.

  5. Teleseismic Travel-Time Tomography of the Sierra Nevada and its Foundering Lithosphere

    Science.gov (United States)

    Reeg, H.; Jones, C. H.; Gilbert, H.; Owens, T.; Zandt, G.

    2007-12-01

    Inferences of foundering lithosphere under the southern Sierra have mostly been based upon xenolith petrology and seismic tomography. To better evaluate the extent and geometry of any such unstable lithosphere, we timed teleseismic bodywave arrivals from approximately 500 teleseisms at 75 stations occupied for 1 or 2 years by the Sierra Nevada Earthscope Project (SNEP) and about 15 Earthscope Transportable Array (TA) stations in the region of the Sierra. With the SNEP footprint, stations are spaced about 25 km apart and extend roughly 400 km along the range and 150 km normal to the range. Additional TA stations extend the aperture of the array to about 600 km. Events were chosen to get the best signal-to-noise ratio while optimizing the backazimuthal coverage. P- wave arrival times were determined simultaneously across all stations for each event using a waveform correlation technique developed by G. Pavlis (dbxcor). Initial examination of the travel-time residuals indicates that no substantial lithospheric downwelling exists between the previously recognized "Isabella anomaly" at the southern end of the range and the approximate position of the south edge of the Gorda plate. Residuals in the Basin and Range are generally small but consistently late compared to stations to the west, but large differences in residuals (>1 s) in the western Sierran foothills can occur over short (~50 km) distances, suggesting substantial heterogeneity in the crust or uppermost mantle. Results of a 3-D isotropic inversion will be presented, and any systematic residual patterns remaining will be evaluated with an eye towards identifying any anisotropy.

  6. Tissue-specific responses to the LRPPRC founder mutation in French Canadian Leigh Syndrome.

    Science.gov (United States)

    Sasarman, Florin; Nishimura, Tamiko; Antonicka, Hana; Weraarpachai, Woranontee; Shoubridge, Eric A

    2015-01-15

    French Canadian Leigh Syndrome (LSFC) is an early-onset, progressive neurodegenerative disorder with a distinct pattern of tissue involvement. Most cases are caused by a founder missense mutation in LRPPRC. LRPPRC forms a ribonucleoprotein complex with SLIRP, another RNA-binding protein, and this stabilizes polyadenylated mitochondrial mRNAs. LSFC fibroblasts have reduced levels of LRPPRC and a specific complex IV assembly defect; however, further depletion of mutant LRPPRC results in a complete failure to assemble a functional oxidative phosphorylation system, suggesting that LRPPRC levels determine the nature of the biochemical phenotype. We tested this hypothesis in cultured muscle cells and tissues from LSFC patients. LRPPRC levels were reduced in LSFC muscle cells, resulting in combined complex I and IV deficiencies. A similar combined deficiency was observed in skeletal muscle. Complex IV was only moderately reduced in LSFC heart, but was almost undetectable in liver. Both of these tissues showed elevated levels of complexes I and III. Despite the marked biochemical differences, the steady-state levels of LRPPRC and mitochondrial mRNAs were extremely low, LRPPRC was largely detergent-insoluble, and SLIRP was undetectable in all LSFC tissues. The level of the LRPPRC/SLIRP complex appeared much reduced in control tissues by the first dimension blue-native polyacrylamide gel electrophoresis (BN-PAGE) analysis compared with fibroblasts, and even by second dimension analysis it was virtually undetectable in control heart. These results point to tissue-specific pathways for the post-transcriptional handling of mitochondrial mRNAs and suggest that the biochemical defects in LSFC reflect the differential ability of tissues to adapt to the mutation. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  7. Global isolation by distance despite strong regional phylogeography in a small metazoan

    Directory of Open Access Journals (Sweden)

    Mills Scott

    2007-11-01

    Full Text Available Abstract Background Small vagile eukaryotic organisms, which comprise a large proportion of the Earth's biodiversity, have traditionally been thought to lack the extent of population structuring and geographic speciation observed in larger taxa. Here we investigate the patterns of genetic diversity, amongst populations of the salt lake microscopic metazoan Brachionus plicatilis s. s. (sensu stricto (Rotifera: Monogononta on a global scale. We examine the phylogenetic relationships of geographic isolates from four continents using a 603 bp fragment of the mitochondrial COI gene to investigate patterns of phylogeographic subdivision in this species. In addition we investigate the relationship between genetic and geographic distances on a global scale to try and reconcile the paradox between the high vagility of this species and the previously reported patterns of restricted gene flow, even over local spatial scales. Results Analysis of global sequence diversity of B. plicatilis s. s. reveals the presence of four allopatric genetic lineages: North American-Far East Asian, Western Mediterranean, Australian, and an Eastern Mediterranean lineage represented by a single isolate. Geographically orientated substructure is also apparent within the three best sampled lineages. Surprisingly, given this strong phylogeographic structure, B. plicatilis s. s. shows a significant correlation between geographic and genetic distance on a global scale ('isolation by distance' – IBD. Conclusion Despite its cosmopolitan distribution and potential for high gene flow, B. plicatilis s. s. is strongly structured at a global scale. IBD patterns have traditionally been interpreted to indicate migration-drift equilibrium, although in this system equilibrium conditions are incompatible with the observed genetic structure. Instead, we suggest the pattern may have arisen through persistent founder effects, acting in a similar fashion to geographic barriers for larger

  8. Effect of the Strong4Life School Nutrition Program on Cafeterias and on Manager and Staff Member Knowledge and Practice, Georgia, 2015.

    Science.gov (United States)

    Rajbhandari-Thapa, Janani; Bennett, Ashley; Keong, Farrah; Palmer, Wendy; Hardy, Trisha; Welsh, Jean

    The goal of the Strong4Life School Nutrition Program is to promote healthy eating in school cafeterias in Georgia by training school nutrition managers and staff members to implement changes in the cafeteria to nudge children to make healthier choices. The objective of our study was to evaluate program effect on (1) school nutrition manager and staff member knowledge of evidence-based strategies and their self-efficacy to make positive changes, (2) the school cafeteria environment, and (3) National School Lunch Program participation. We assessed changes in participant knowledge, beliefs, and self-efficacy by administering a survey before and after training (February-July 2015); a follow-up survey (3 school months posttraining) assessed changes in the cafeteria. A total of 842 school nutrition managers and staff members were trained and completed pre- and posttraining surveys; 325 managers completed the follow-up survey. We used cafeteria records from a subsample of the first schools trained (40 intervention and 40 control) to assess National School Lunch Program participation. From pretraining to posttraining, we found a significant increase in manager and staff member (n = 842) knowledge of strategies for enhancing taste perception through the use of creative menu item names (from 78% to 95%, P food placement in the lunch line influences food selection (from 78% to 95%, P cafeteria environment (from 91% to 96%, P 2 locations, P School Lunch Program participation did not change significantly. Training cafeteria managers and staff members in Smarter Lunchrooms Movement techniques may be an effective way to make changes in the school cafeteria environment to encourage healthier choices among students. Additional studies allowing time for more complex changes to be implemented are needed to assess the full effect of the program.

  9. The Brazil SimSmoke policy simulation model: the effect of strong tobacco control policies on smoking prevalence and smoking-attributable deaths in a middle income nation.

    Directory of Open Access Journals (Sweden)

    David Levy

    Full Text Available Brazil has reduced its smoking rate by about 50% in the last 20 y. During that time period, strong tobacco control policies were implemented. This paper estimates the effect of these stricter policies on smoking prevalence and associated premature mortality, and the effect that additional policies may have.The model was developed using the SimSmoke tobacco control policy model. Using policy, population, and smoking data for Brazil, the model assesses the effect on premature deaths of cigarette taxes, smoke-free air laws, mass media campaigns, marketing restrictions, packaging requirements, cessation treatment programs, and youth access restrictions. We estimate the effect of past policies relative to a counterfactual of policies kept to 1989 levels, and the effect of stricter future policies. Male and female smoking prevalence in Brazil have fallen by about half since 1989, which represents a 46% (lower and upper bounds: 28%-66% relative reduction compared to the 2010 prevalence under the counterfactual scenario of policies held to 1989 levels. Almost half of that 46% reduction is explained by price increases, 14% by smoke-free air laws, 14% by marketing restrictions, 8% by health warnings, 6% by mass media campaigns, and 10% by cessation treatment programs. As a result of the past policies, a total of almost 420,000 (260,000-715,000 deaths had been averted by 2010, increasing to almost 7 million (4.5 million-10.3 million deaths projected by 2050. Comparing future implementation of a set of stricter policies to a scenario with 2010 policies held constant, smoking prevalence by 2050 could be reduced by another 39% (29%-54%, and 1.3 million (0.9 million-2.0 million out of 9 million future premature deaths could be averted.Brazil provides one of the outstanding public health success stories in reducing deaths due to smoking, and serves as a model for other low and middle income nations. However, a set of stricter policies could further reduce

  10. Study of dynamical properties in a bi-dimensional model describing the prey–predator dynamics with strong Allee effect in prey.

    Directory of Open Access Journals (Sweden)

    Partha Mandal

    2017-12-01

    Full Text Available In this work, we analyze a bi-dimensional differential equation system obtained by considering Holling type II functional response in prey–predator model with strong Allee effect in prey. One of the important consequence of this modification is the existence of separatrix curve which divides the behaviour of the trajectories in the phase plane. The results show that the origin is an attractor for any set of parameter values. Axial equilibrium points are stable or unstable according to the different parametric restrictions. The unique positive equilibrium point, if it exists, can be either an attractor or a repeller surrounded by a limit cycle, whose stability and uniqueness are also established. Therefore long-term coexistence of both populations is possible or they can go to extinction. Conditions on the parameter values are derived to show that the positive equilibrium point can be emerged or annihilated through transcritical bifurcation at axial equilibrium points. The existence of two heteroclinic curves is also established. It is also demonstrated that the origin is a global attractor in the phase plane for some parameter values, which implies that there are satisfying conditions where both populations can go to extinction. Ecological interpretations of all analytical results are provided thoroughly.

  11. [Effects of sowing date and planting density on the grain' s protein component and quality of strong and medium gluten winter wheat cultivars].

    Science.gov (United States)

    Yan, Cui-ping; Zhang, Yong-qing; Zhang, Ding-yi; Dang, Jian-you

    2008-08-01

    In a field experiment with split-split plot design, the effects of sowing date and planting density on the grain's protein component and quality of strong gluten wheat cultivar Linyou 145 and medium gluten wheat cultivar Linyou 2018 were studied. The results showed that proper sowing date brought the highest protein content and yield in wheat grain. With sowing date postponed, the grain's gliadin and glutenin contents of Linyou 145 increased obviously, while those of Linyou 2018 changed little. The grain quality of Linyou 145 was more affected by sowing date, compared with that of Linyou 2018. When sowing at proper date, the grain's protein and glutenin contents had significant correlations with its wet gluten content, sedimentation value, dough stability time, softness, and evaluation value; while when the sowing date postponed, there existed a positive correlation between the contents of gliadin and wet gluten. The change of the proportions of different protein components in wheat grain induced by the variation of sowing date could be the main reason of the improvement in wheat grain quality. Within the test range (2.25 million - 3.75 million plants x hm(-2)) of planting density, the grain's protein content was less affected, but the grain quality of Linyou 145 was affected to a certain extent. Low planting density (2.25 million plants x hm(-2)) brought the best grain quality of Linyou 2018.

  12. Bubble Formation within Filaments of Melt-Processed Bi2212 wires and its strongly negative effect on the Critical Current Density

    CERN Document Server

    Kametani, F; Jiang, J; Scheuerlein, C; Malagoli, A; Di Michiel, M; Huang, Y; Miao, H; Parrell, J A; Hellstrom, E E; Larbalestier, D C

    2011-01-01

    Most studies of Bi2Sr2CaCu2Ox (Bi2212) show that the critical current density Jc is limited by the connectivity of the filaments, but what determines the connectivity is still elusive. Here we report on the role played by filament porosity in limiting Jc. By a microstructural investigation of wires quenched from the melt state, we find that porosity in the unreacted wire agglomerates into bubbles that segment the Bi2212 melt within the filaments into discrete sections. These bubbles do not disappear during subsequent processing because they are only partially filled by Bi2212 grains as the Bi2212 forms on cooling. Correlating the microstructure of quenched wires to their final, fully processed Jc values shows an inverse relation between Jc and bubble density. Bubbles are variable between conductors and perhaps from sample to sample, but they occur frequently and almost completely fill the filament diameter, so they exert a strongly variable but always negative effect on Jc. Bubbles reduce the continuous Bi221...

  13. LIGO: The strong belief

    CERN Multimedia

    Antonella Del Rosso

    2016-01-01

    Twenty years of designing, building and testing a number of innovative technologies, with the strong belief that the endeavour would lead to a historic breakthrough. The Bulletin publishes an abstract of the Courier’s interview with Barry Barish, one of the founding fathers of LIGO.   The plots show the signals of gravitational waves detected by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. (Image: Caltech/MIT/LIGO Lab) On 11 February, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and Virgo collaborations published a historic paper in which they showed a gravitational signal emitted by the merger of two black holes. These results come after 20 years of hard work by a large collaboration of scientists operating the two LIGO observatories in the US. Barry Barish, Linde Professor of Physics, Emeritus at the California Institute of Technology and former Director of the Global Design Effort for the Internat...

  14. Measles Virus Mutants Possessing the Fusion Protein with Enhanced Fusion Activity Spread Effectively in Neuronal Cells, but Not in Other Cells, without Causing Strong Cytopathology

    Science.gov (United States)

    Ohno, Shinji; Shirogane, Yuta; Suzuki, Satoshi O.; Koga, Ritsuko

    2014-01-01

    ABSTRACT Subacute sclerosing panencephalitis (SSPE) is caused by persistent measles virus (MV) infection in the central nervous system (CNS). Since human neurons, its main target cells, do not express known MV receptors (signaling lymphocyte activation molecule [SLAM] and nectin 4), it remains to be understood how MV infects and spreads in them. We have recently reported that fusion-enhancing substitutions in the extracellular domain of the MV fusion (F) protein (T461I and S103I/N462S/N465S), which are found in multiple SSPE virus isolates, promote MV spread in human neuroblastoma cell lines and brains of suckling hamsters. In this study, we show that hyperfusogenic viruses with these substitutions also spread efficiently in human primary neuron cultures without inducing syncytia. These substitutions were found to destabilize the prefusion conformation of the F protein trimer, thereby enhancing fusion activity. However, these hyperfusogenic viruses exhibited stronger cytopathology and produced lower titers at later time points in SLAM- or nectin 4-expressing cells compared to the wild-type MV. Although these viruses spread efficiently in the brains of SLAM knock-in mice, they did not in the spleens. Taken together, the results suggest that enhanced fusion activity is beneficial for MV to spread in neuronal cells where no cytopathology occurs, but detrimental to other types of cells due to strong cytopathology. Acquisition of enhanced fusion activity through substitutions in the extracellular domain of the F protein may be crucial for MV's extensive spread in the CNS and development of SSPE. IMPORTANCE Subacute sclerosing panencephalitis (SSPE) is a fatal disease caused by persistent measles virus (MV) infection in the central nervous system (CNS). Its cause is not well understood, and no effective therapy is currently available. Recently, we have reported that enhanced fusion activity of MV through the mutations in its fusion protein is a major determinant of

  15. A novel VU-MRCC formalism for the simultaneous treatment of strong relaxation and correlation effects with applications to electron affinity of neutral radicals

    International Nuclear Information System (INIS)

    Jana, Debasis; Datta, Dipayan; Mukherjee, Debashis

    2006-01-01

    We present and implement in this paper a novel spin-free valence-universal multi-reference coupled cluster (VU-MRCC) formalism for energy differences which can capture orbital relaxation and correlation relaxation to all orders. Unlike in the traditional normal ordered cluster Ansatz for computing energy differences, this cluster expansion formalism allows contractions between various valence excitation operators with valence spectator lines. These contractions simulate the orbital relaxation and correlation relaxation effects for the ionized/excited states via Thouless-like exponential type of operators. Generally such operators are non-commuting. To ensure that each distinct excitation generated by contracted composites formed by these operators appear only once in the wave-operators, the factors accompanying these composites have to be judiciously chosen. Hence, the combinatoric factors accompanying such contracted composites are not taken to be 1/n! for nth-power, but rather the inverse of the automorphic factor (the number of ways the n operators can be connected in various permutations generating the same composite). It is shown that this Ansatz leads to a set of VU-MRCC equations for the valence cluster amplitudes, in which all the cluster operators are attached to the hamiltonian by at least one non-spectator line (a strongly connected series). The series is thus terminating at the quartic power. Illustrative applications are presented by computing electron affinity of neutral doublet radicals (viz., NH 2 , OH, F, BO and CN), where the orbital relaxation effect attendant on the anion formation is considerable. Several basis-sets capable of describing the anions have been studied. It has been found that aug-cc-pVTZ basis gives the best overall results, while aug-cc-pVQZ overestimates the electron affinity, presumably because of an imbalance in describing the neutral radicals. The method performs consistently much better then the one with the traditional

  16. The effect of a strong stellar flare on the atmospheric chemistry of an earth-like planet orbiting an M dwarf.

    Science.gov (United States)

    Segura, Antígona; Walkowicz, Lucianne M; Meadows, Victoria; Kasting, James; Hawley, Suzanne

    2010-09-01

    Main sequence M stars pose an interesting problem for astrobiology: their abundance in our galaxy makes them likely targets in the hunt for habitable planets, but their strong chromospheric activity produces high-energy radiation and charged particles that may be detrimental to life. We studied the impact of the 1985 April 12 flare from the M dwarf AD Leonis (AD Leo), simulating the effects from both UV radiation and protons on the atmospheric chemistry of a hypothetical, Earth-like planet located within its habitable zone. Based on observations of solar proton events and the Neupert effect, we estimated a proton flux associated with the flare of 5.9 × 10⁸ protons cm⁻² sr⁻¹ s⁻¹ for particles with energies >10 MeV. Then we calculated the abundance of nitrogen oxides produced by the flare by scaling the production of these compounds during a large solar proton event called the Carrington event. The simulations were performed with a 1-D photochemical model coupled to a 1-D radiative/convective model. Our results indicate that the UV radiation emitted during the flare does not produce a significant change in the ozone column depth of the planet. When the action of protons is included, the ozone depletion reaches a maximum of 94% two years after the flare for a planet with no magnetic field. At the peak of the flare, the calculated UV fluxes that reach the surface, in the wavelength ranges that are damaging for life, exceed those received on Earth during less than 100 s. Therefore, flares may not present a direct hazard for life on the surface of an orbiting habitable planet. Given that AD Leo is one of the most magnetically active M dwarfs known, this conclusion should apply to planets around other M dwarfs with lower levels of chromospheric activity.

  17. John Strong (1941 - 2006)

    CERN Multimedia

    Wickens, F

    Our friend and colleague John Strong was cruelly taken from us by a brain tumour on Monday 31st July, a few days before his 65th birthday John started his career working with a group from Westfield College, under the leadership of Ted Bellamy. He obtained his PhD and spent the early part of his career on experiments at Rutherford Appleton Laboratory (RAL), but after the early 1970s his research was focussed on experiments in CERN. Over the years he made a number of notable contributions to experiments in CERN: The Omega spectrometer adopted a system John had originally developed for experiments at RAL using vidicon cameras to record the sparks in the spark chambers; He contributed to the success of NA1 and NA7, where he became heavily involved in the electronic trigger systems; He was responsible for the second level trigger system for the ALEPH detector and spent five years leading a team that designed and built the system, which ran for twelve years with only minor interventions. Following ALEPH he tur...

  18. Stirring Strongly Coupled Plasma

    CERN Document Server

    Fadafan, Kazem Bitaghsir; Rajagopal, Krishna; Wiedemann, Urs Achim

    2009-01-01

    We determine the energy it takes to move a test quark along a circle of radius L with angular frequency w through the strongly coupled plasma of N=4 supersymmetric Yang-Mills (SYM) theory. We find that for most values of L and w the energy deposited by stirring the plasma in this way is governed either by the drag force acting on a test quark moving through the plasma in a straight line with speed v=Lw or by the energy radiated by a quark in circular motion in the absence of any plasma, whichever is larger. There is a continuous crossover from the drag-dominated regime to the radiation-dominated regime. In the crossover regime we find evidence for significant destructive interference between energy loss due to drag and that due to radiation as if in vacuum. The rotating quark thus serves as a model system in which the relative strength of, and interplay between, two different mechanisms of parton energy loss is accessible via a controlled classical gravity calculation. We close by speculating on the implicati...

  19. Strong-interaction nonuniversality

    International Nuclear Information System (INIS)

    Volkas, R.R.; Foot, R.; He, X.; Joshi, G.C.

    1989-01-01

    The universal QCD color theory is extended to an SU(3) 1 direct product SU(3) 2 direct product SU(3) 3 gauge theory, where quarks of the ith generation transform as triplets under SU(3)/sub i/ and singlets under the other two factors. The usual color group is then identified with the diagonal subgroup, which remains exact after symmetry breaking. The gauge bosons associated with the 16 broken generators then form two massive octets under ordinary color. The interactions between quarks and these heavy gluonlike particles are explicitly nonuniversal and thus an exploration of their physical implications allows us to shed light on the fundamental issue of strong-interaction universality. Nonuniversality and weak flavor mixing are shown to generate heavy-gluon-induced flavor-changing neutral currents. The phenomenology of these processes is studied, as they provide the major experimental constraint on the extended theory. Three symmetry-breaking scenarios are presented. The first has color breaking occurring at the weak scale, while the second and third divorce the two scales. The third model has the interesting feature of radiatively induced off-diagonal Kobayashi-Maskawa matrix elements

  20. Nature of the basement of the East Anatolian plateau: Implications for the lithospheric foundering processes

    Science.gov (United States)

    Topuz, G.; Candan, O.; Zack, T.; Yılmaz, A.

    2017-12-01

    Anatolian plateau have resulted from other processes of lithospheric foundering, rather than just slab steepening and break-off. This research is funded by a research grant (#114Y228) from TÜBİTAK.

  1. Particulate matter from both heavy fuel oil and diesel fuel shipping emissions show strong biological effects on human lung cells at realistic and comparable in vitro exposure conditions.

    Directory of Open Access Journals (Sweden)

    Sebastian Oeder

    Full Text Available Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling.To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols.Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO or cleaner-burning diesel fuel (DF. Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses.The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon ("soot". Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification.Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the use of HFO and DF we recommend a

  2. Particulate Matter from Both Heavy Fuel Oil and Diesel Fuel Shipping Emissions Show Strong Biological Effects on Human Lung Cells at Realistic and Comparable In Vitro Exposure Conditions

    Science.gov (United States)

    Dilger, Marco; Paur, Hanns-Rudolf; Schlager, Christoph; Mülhopt, Sonja; Diabaté, Silvia; Weiss, Carsten; Stengel, Benjamin; Rabe, Rom; Harndorf, Horst; Torvela, Tiina; Jokiniemi, Jorma K.; Hirvonen, Maija-Riitta; Schmidt-Weber, Carsten; Traidl-Hoffmann, Claudia; BéruBé, Kelly A.; Wlodarczyk, Anna J.; Prytherch, Zoë; Michalke, Bernhard; Krebs, Tobias; Prévôt, André S. H.; Kelbg, Michael; Tiggesbäumker, Josef; Karg, Erwin; Jakobi, Gert; Scholtes, Sorana; Schnelle-Kreis, Jürgen; Lintelmann, Jutta; Matuschek, Georg; Sklorz, Martin; Klingbeil, Sophie; Orasche, Jürgen; Richthammer, Patrick; Müller, Laarnie; Elsasser, Michael; Reda, Ahmed; Gröger, Thomas; Weggler, Benedikt; Schwemer, Theo; Czech, Hendryk; Rüger, Christopher P.; Abbaszade, Gülcin; Radischat, Christian; Hiller, Karsten; Buters, Jeroen T. M.; Dittmar, Gunnar; Zimmermann, Ralf

    2015-01-01

    Background Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. Objectives To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular responses they elicit and to identify potentially harmful fractions in shipping emission aerosols. Methods Through an air-liquid interface exposure system, we exposed human lung cells under realistic in vitro conditions to exhaust fumes from a ship engine running on either common heavy fuel oil (HFO) or cleaner-burning diesel fuel (DF). Advanced chemical analyses of the exhaust aerosols were combined with transcriptional, proteomic and metabolomic profiling including isotope labelling methods to characterise the lung cell responses. Results The HFO emissions contained high concentrations of toxic compounds such as metals and polycyclic aromatic hydrocarbon, and were higher in particle mass. These compounds were lower in DF emissions, which in turn had higher concentrations of elemental carbon (“soot”). Common cellular reactions included cellular stress responses and endocytosis. Reactions to HFO emissions were dominated by oxidative stress and inflammatory responses, whereas DF emissions induced generally a broader biological response than HFO emissions and affected essential cellular pathways such as energy metabolism, protein synthesis, and chromatin modification. Conclusions Despite a lower content of known toxic compounds, combustion particles from the clean shipping fuel DF influenced several essential pathways of lung cell metabolism more strongly than particles from the unrefined fuel HFO. This might be attributable to a higher soot content in DF. Thus the role of diesel soot, which is a known carcinogen in acute air pollution-induced health effects should be further investigated. For the

  3. Unique Phenotypic Characteristics of Recently Transmitted HIV-1 Subtype C Envelope Glycoprotein gp120: Use of CXCR6 Coreceptor by Transmitted Founder Viruses.

    Science.gov (United States)

    Ashokkumar, Manickam; Aralaguppe, Shambhu G; Tripathy, Srikanth P; Hanna, Luke Elizabeth; Neogi, Ujjwal

    2018-05-01

    Adequate information on the precise molecular and biological composition of the viral strains that establish HIV infection in the human host will provide effective means of immunization against HIV infection. In an attempt to identify the transmitted founder (TF) virus and differentiate the biological properties and infectious potential of the TF virus from those of the population of the early transmitted viruses, 250 patient-derived gp120 envelope glycoproteins were cloned in pMN-K7-Luc-IRESs-NefΔgp120 to obtain chimeric viruses. Samples were obtained from eight infants who had recently become infected with HIV through mother-to-child transmission (MTCT) and two adults who acquired infection through the heterosexual route and were in the chronic stage of infection. Among the 250 clones tested, 65 chimeric viruses were infectious, and all belonged to HIV-1 subtype C. The 65 clones were analyzed for molecular features of the envelope, per-infectious-particle infectivity, coreceptor tropism, drug sensitivity, and sensitivity to broadly neutralizing antibodies. Based on genotypic and phenotypic analysis of the viral clones, we identified 10 TF viruses from the eight infants. The TF viruses were characterized by shorter V1V2 regions, a reduced number of potential N-linked glycosylation sites, and a higher infectivity titer compared to the virus variants from the adults in the chronic stage of infection. CXCR6 coreceptor usage, in addition to that of the CCR5 coreceptor, which was used by all 65 chimeric viruses, was identified in 13 viruses. The sensitivity of the TF variants to maraviroc and a standard panel of neutralizing monoclonal antibodies (VRC01, PG09, PG16, and PGT121) was found to be much lower than that of the virus variants from the adults in the chronic stage of infection. IMPORTANCE Tremendous progress has been made during the last three and half decades of HIV research, but some significant gaps continue to exist. One of the frontier areas of HIV

  4. "Founder crops" v. wild plants: Assessing the plant-based diet of the last hunter-gatherers in southwest Asia

    Science.gov (United States)

    Arranz-Otaegui, Amaia; González Carretero, Lara; Roe, Joe; Richter, Tobias

    2018-04-01

    The Natufian culture (c. 14.6-11.5 ka cal. BP) represents the last hunter-gatherer society that inhabited southwest Asia before the development of plant food production. It has long been suggested that Natufians based their economy on the exploitation of the wild ancestors of the Neolithic "founder crops", and that these hunter-gatherers were therefore on the "threshold to agriculture". In this work we review the available data on Natufian plant exploitation and we report new archaeobotanical evidence from Shubayqa 1, a Natufian site located in northeastern Jordan (14.6-11.5 ka cal. BP). Shubayqa 1 has produced an exceptionally large plant assemblage, including direct evidence for the continuous exploitation of club-rush tubers (often regarded as "missing foods") and other wild plants, which were probably used as food, fuel and building materials. Taking together this data we evaluate the composition of archaeobotanical assemblages (plant macroremains) from the Natufian to the Early Pre-Pottery Neolithic B (EPPNB). Natufian assemblages comprise large proportions of non-founder plant species (>90% on average), amongst which sedges, small-seeded grasses and legumes, and fruits and nuts predominate. During the Pre-Pottery Neolithic, in particular the EPPNB, the presence of "founder crops" increases dramatically and constitute up to c. 42% of the archaeobotanical assemblages on average. Our results suggest that plant exploitation strategies during the Natufian were very different from those attested during subsequent Neolithic periods. We argue that historically driven interpretations of the archaeological record have over-emphasized the role of the wild ancestors of domesticated crops previous to the emergence of agriculture.

  5. PREFACE: Strongly correlated electron systems Strongly correlated electron systems

    Science.gov (United States)

    Saxena, Siddharth S.; Littlewood, P. B.

    2012-07-01

    This special section is dedicated to the Strongly Correlated Electron Systems Conference (SCES) 2011, which was held from 29 August-3 September 2011, in Cambridge, UK. SCES'2011 is dedicated to 100 years of superconductivity and covers a range of topics in the area of strongly correlated systems. The correlated electronic and magnetic materials featured include f-electron based heavy fermion intermetallics and d-electron based transition metal compounds. The selected papers derived from invited presentations seek to deepen our understanding of the rich physical phenomena that arise from correlation effects. The focus is on quantum phase transitions, non-Fermi liquid phenomena, quantum magnetism, unconventional superconductivity and metal-insulator transitions. Both experimental and theoretical work is presented. Based on fundamental advances in the understanding of electronic materials, much of 20th century materials physics was driven by miniaturisation and integration in the electronics industry to the current generation of nanometre scale devices. The achievements of this industry have brought unprecedented advances to society and well-being, and no doubt there is much further to go—note that this progress is founded on investments and studies in the fundamentals of condensed matter physics from more than 50 years ago. Nevertheless, the defining challenges for the 21st century will lie in the discovery in science, and deployment through engineering, of technologies that can deliver the scale needed to have an impact on the sustainability agenda. Thus the big developments in nanotechnology may lie not in the pursuit of yet smaller transistors, but in the design of new structures that can revolutionise the performance of solar cells, batteries, fuel cells, light-weight structural materials, refrigeration, water purification, etc. The science presented in the papers of this special section also highlights the underlying interest in energy-dense materials, which

  6. [Shestov V I--the founder of the Department of Organisation and tactics of the naval medical services].

    Science.gov (United States)

    Chernikov, O G; Chernyĭ, V S; Mishin, Iu A; Soshkin, P A

    2014-11-01

    Vasilii Ivanovich Shestov during the Great Patriotic War performed various tasks concerning the organization of medical support in the Leningrad naval base, consulted on an issue of production and use of hospital and medical transport ships, worked on the organization of medical support in Schliessburg and etc. Shestov performed a considerable amount of research and methodological works concerning the establishment of the discipline "Organisation of naval medical support". He is considered as one of the founders of the theory of naval medical evacuation support.

  7. International distribution and age estimation of the Portuguese BRCA2 c.156_157insAlu founder mutation

    DEFF Research Database (Denmark)

    Peixoto, Ana; Santos, Catarina; Pinheiro, Manuela

    2011-01-01

    The c.156_157insAlu BRCA2 mutation has so far only been reported in hereditary breast/ovarian cancer (HBOC) families of Portuguese origin. Since this mutation is not detectable using the commonly used screening methodologies and must be specifically sought, we screened for this rearrangement...... individuals requesting predictive testing living in France and in the USA, all being Portuguese immigrants. After performing an extensive haplotype study in carrier families, we estimate that this founder mutation occurred 558 ± 215 years ago. We further demonstrate significant quantitative differences...... HBOC families from Portugal or with Portuguese ancestry are specifically tested for this rearrangement....

  8. Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to Sr2RuO4

    Directory of Open Access Journals (Sweden)

    James Avery Sauls

    2015-06-01

    Full Text Available Recent theories of Sr2RuO4 based on the interplay of strong interactions, spin-orbit coupling and multi-band anisotropy predict chiral or helical ground states with strong anisotropy of the pairing states, with deep minima in the excitation gap, as well as strong phase anisotropy for the chiral ground state. We develop time-dependent mean field theory to calculate the Bosonic spectrum for the class of 2D chiral superconductors spanning 3He-A to chiral superconductors with strong anisotropy. Chiral superconductors support a pair of massive Bosonic excitations of the time-reversed pairs labeled by their parity under charge conjugation. These modes are degenerate for 2D 3He-A. Crystal field anisotropy lifts the degeneracy. Strong anisotropy also leads to low-lying Fermions, and thus to channels for the decay of the Bosonic modes. Selection rules and phase space considerations lead to large asymmetries in the lifetimes and hybridization of the Bosonic modes with the continuum of un-bound Fermion pairs. We also highlight results for the excitation of the Bosonic modes by microwave radiation that provide clear signatures of the Bosonic modes of an anisotropic chiral ground state.

  9. Strongly Interacting Light Dark Matter

    Directory of Open Access Journals (Sweden)

    Sebastian Bruggisser, Francesco Riva, Alfredo Urbano

    2017-09-01

    Full Text Available In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM can appear weakly coupled at small energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo Nambu-Goldstone Bosons and Goldstini are interesting targets for LHC missing-energy searches.

  10. Strongly interacting light dark matter

    International Nuclear Information System (INIS)

    Bruggisser, Sebastian; Riva, Francesco; Urbano, Alfredo

    2016-07-01

    In the presence of approximate global symmetries that forbid relevant interactions, strongly coupled light Dark Matter (DM) can appear weakly coupled at small-energy and generate a sizable relic abundance. Fundamental principles like unitarity restrict these symmetries to a small class, where the leading interactions are captured by effective operators up to dimension-8. Chiral symmetry, spontaneously broken global symmetries and non-linearly realized supersymmetry are examples of this. Their DM candidates (composite fermions, pseudo-Nambu-Goldstone Bosons and Goldstini) are interesting targets for LHC missing-energy searches.

  11. Application of strong phosphoric acid to radiochemistry

    International Nuclear Information System (INIS)

    Terada, Kikuo

    1977-01-01

    Not only inorganic and organic compounds but also natural substrances, such as accumulations in soil, are completely decomposed and distilled by heating with strong phosphoric acid for 30 to 50 minutes. As applications of strong phosphoric acid to radiochemistry, determination of uranium and boron by use of solubilization effect of this substance, titration of uranyl ion by use of sulfuric iron (II) contained in this substance, application to tracer experiment, and determination of radioactive ruthenium in environmental samples are reviewed. Strong phosphoric acid is also applied to activation analysis, for example, determination of N in pyrographite with iodate potassium-strong phosphoric acid method, separation of Os and Ru with sulfuric cerium (IV) - strong phosphoric acid method or potassium dechromate-strong phosphoric acid method, analysis of Se, As and Sb rocks and accumulations with ammonium bromide, sodium chloride and sodium bromide-strong phosphoric acid method. (Kanao, N.)

  12. Strong interaction phenomenology

    International Nuclear Information System (INIS)

    Giffon, M.

    1989-01-01

    A brief review of high energy hadronic data (Part I)is followed by an introduction to the standard (Weinberg Salam Glashow) model of electroweak interactions and its extension to the hadrons (Part II). Rudiments of QCD and of the parton model area given in Part III together with a quick review of the spectroscopy of heavy flavours whereas Part IV is devoted to the introduction to deep inelastic scattering and to the so-called EMC effects. (author)

  13. Haplotype analysis suggest common founders in carriers of the recurrent BRCA2 mutation, 3398delAAAAG, in French Canadian hereditary breast and/ovarian cancer families

    Directory of Open Access Journals (Sweden)

    Foulkes William D

    2006-03-01

    Full Text Available Abstract Background The 3398delAAAAG mutation in BRCA2 was recently found to recur in breast and/or ovarian cancer families from the French Canadian population of Quebec, a population that has genetic attributes consistent with a founder effect. To characterize the contribution of this mutation in this population, this study established the frequency of this mutation in breast and ovarian cancer cases unselected for family history of cancer, and determined if mutation carriers shared a common ancestry. Methods The frequency was estimated by assaying the mutation in series of French Canadian breast cancer cases diagnosed before age 41 (n = 60 or 80 (n = 127 years of age, and ovarian cancer cases (n = 80 unselected for family history of cancer by mutation analysis. Haplotype analysis was performed to determine if mutation carriers shared a common ancestry. Members from 11 families were analyzed using six polymorphic microsatellite markers (cen-D13S260-D13S1699-D13S1698-D13S1697-D13S1701-D13S171-tel spanning approximately a 3.6 cM interval at the chromosomal region 13q13.1, which contains BRCA2. Allele frequencies were estimated by genotyping 47 unaffected female individuals derived from the same population. Haplotype reconstruction of unaffected individuals was performed using the program PHASE. Results The recurrent BRCA2 mutation occurred in 1 of 60 (1.7% women diagnosed with breast cancer before 41 years of age and one of 80 (1.3% women with ovarian cancer. No mutation carriers were identified in the series of breast cancer cases diagnosed before age 80. Mutation carriers harboured one of two haplotypes, 7-3-9-3 – [3/4]-7, that varied with marker D13S1701 and which occurred at a frequency of 0.001. The genetic analysis of D13S1695, a polymorphic marker located approximately 0.3 cM distal to D13S171, did not favour a genetic recombination event to account for the differences in D13S1701 alleles within the haplotype. Although mutation carriers

  14. Effect of exotic long-lived sub-strongly interacting massive particles in big bang nucleosynthesis and a new solution to the Li problem

    Directory of Open Access Journals (Sweden)

    Kawasaki Masahiro

    2012-02-01

    Full Text Available The plateau of 7Li abundance as a function of the iron abundance by spectroscopic observations of metal-poor halo stars (MPHSs indicates its primordial origin. The observed abundance levels are about a factor of three smaller than the primordial 7Li abundance predicted in the standard Big Bang Nucleosynthesis (BBN model. This discrepancy might originate from exotic particle and nuclear processes operating in BBN epoch. Some particle models include heavy (m >> 1 GeV long-lived colored particles which would be confined inside exotic heavy hadrons, i.e., strongly interacting massive particles (SIMPs. We have found reactions which destroy 7Be and 7Li during BBN in the scenario of BBN catalyzed by a long-lived sub-strongly interacting massive particle (sub-SIMP, X. The reactions are non radiative X captures of 7 Be and 7Li which can be operative if the X particle interacts with nuclei strongly enough to drive 7 Be destruction but not strongly enough to form a bound state with 4 He of relative angular momentum L = 1. We suggest that 7Li problem can be solved as a result of a new process beyond the standard model through which the observable signature was left on the primordial Li abundance.

  15. The Unseen Founders Of Quaternary Science - The Men Of Glasgow, Scotland (Invited)

    Science.gov (United States)

    Rose, J.

    2010-12-01

    Louis Agassiz (1807-1873) and Charles Lyell (1797-1875) are widely regarded as the founders of Quaternary Science, and there is no doubt that they played their part: Agassiz in 1840 presented and promoted his case for the wide-scale fluctuations of glaciers, and Lyell, through his books and contacts, did much to introduce the subject which we now know as climate change. However there are a number of individuals who contributed to the founding of Quaternary Science who are not so readily recognised and a remarkable fact is that a significant proportion were men without academic training or background who come from, or worked in Glasgow or the adjacent region of central Scotland. First amongst the Glaswegians was James Smith (1782-1867) who, in 1836 presented a paper to the Geological Society of London (where it was duly ignored) in which he suggested, on the basis of fossils dredged from the bed of the Clyde and experience of sailing around Iceland, that the climate of Scotland had been as cold as that of Iceland in the recent past. In 1841, Charles Maclaren (1782-1866) a journalist from Edinburgh, but using information based on raised shorelines near Glasgow proposed what we now know as the glacio-eustatic theory in which the variations in glacier extent control the level of the sea. Perhaps the most important of all was James Croll (1821- 1890) who worked on the theory of ice ages, based on orbital forcing, while janitor at the Andersonian Institute and Museum in Glasgow between 1859-1867. This work was the true precursor to the Milankovitch theory which provides the explanation for the major predictable elements of climate change. Robert Jack (1845-1921) from Irvine, southwest of Glasgow, while doing fieldwork for the British Geological Survey near Loch Lomond close to Glasgow, described in 1874 evidence for non-glacial conditions between tills and clearly recognised that climate could change from glacial to temperate and then glacial climate, before returning to

  16. A novel founder MYO15A frameshift duplication is the major cause of genetic hearing loss in Oman.

    Science.gov (United States)

    Palombo, Flavia; Al-Wardy, Nadia; Ruscone, Guido Alberto Gnecchi; Oppo, Manuela; Kindi, Mohammed Nasser Al; Angius, Andrea; Al Lamki, Khalsa; Girotto, Giorgia; Giangregorio, Tania; Benelli, Matteo; Magi, Alberto; Seri, Marco; Gasparini, Paolo; Cucca, Francesco; Sazzini, Marco; Al Khabori, Mazin; Pippucci, Tommaso; Romeo, Giovanni

    2017-02-01

    The increased risk for autosomal recessive disorders is one of the most well-known medical implications of consanguinity. In the Sultanate of Oman, a country characterized by one of the highest rates of consanguineous marriages worldwide, prevalence of genetic hearing loss (GHL) is estimated to be 6/10 000. Families of GHL patients have higher consanguinity rates than the general Omani population, indicating a major role for recessive forms. Mutations in GJB2, the most commonly mutated GHL gene, have been sporadically described. We collected 97 DNA samples of GHL probands, affected/unaffected siblings and parents from 26 Omani consanguineous families. Analyzing a first family by whole-exome sequencing, we identified a novel homozygous frameshift duplication (c.1171_1177dupGCCATCT) in MYO15A, the gene linked to the deafness locus DFNB3. This duplication was then found in a total of 8/26 (28%) families, within a 849 kb founder haplotype. Reconstruction of haplotype structure at MYO15A surrounding genomic regions indicated that the founder haplotype branched out in the past two to three centuries from a haplotype present worldwide. The MYO15A duplication emerges as the major cause of GHL in Oman. These findings have major implications for the design of GHL diagnosis and prevention policies in Oman.

  17. Strongly coupled dust coulomb clusters

    International Nuclear Information System (INIS)

    Juan Wentau; Lai Yingju; Chen Mingheng; I Lin

    1999-01-01

    The structures and motions of quasi-2-dimensional strongly coupled dust Coulomb clusters with particle number N from few to hundreds in a cylindrical rf plasma trap are studied and compared with the results from the molecular dynamic simulation using more ideal models. Shell structures with periodic packing in different shells and intershell rotational motion dominated excitations are observed at small N. As N increases, the boundary has less effect, the system recovers to the triangular lattice with isotropic vortex type cooperative excitations similar to an infinite N system except the outer shell region. The above generic behaviors are mainly determined by the system symmetry and agree with the simulation results. The detailed interaction form causes minor effect such as the fine structure of packing

  18. Genetic variance in the HIV-1 founder virus Vpr affects its ability to induce cell cycle G₂arrest and cell apoptosis.

    Science.gov (United States)

    Zhao, Jian-yuan; Ding, Ji-wei; Mi, Ze-yun; Zhou, Jin-ming; Wei, Tao; Cen, Shan

    2015-05-01

    In the event of acute infection, only a few HIV-1 viral variants can establish the initial productive clinical infection, and these viral variants are known as transmitted/founder viruses (T/F viruses). As one of the accessory proteins of HIV-1, viral protein R (Vpr) plays an important role in viral replication. Therefore, the characterization of T/F virus Vpr is beneficial to understand how virus replicates in a new host. In this study, flow cytometry was used to analyze the effect of G₂arrest and cell apoptosis induced by the T/F virus Vpr and the chronic strain MJ4 Vpr. The results showed that the ability of T/F virus ZM246 Vpr and ZM247 Vpr inducing G₂arrest and cell apoptosis are more potent than the MJ4 Vpr. The comparison of protein sequences indicated that the amino acids of 77, 85 and 94 contain high freqency mutations, suggesting that these sites may be involved in inducing G₂arrest and cell apoptosis. Taken together, our work suggests that in acute infections, T/F viruses increase the capacity of G₂arrest and cell apoptosis and promote viral replication and transmission in a new host by Vpr genetic mutation.

  19. Physics of Strongly Coupled Plasma

    Energy Technology Data Exchange (ETDEWEB)

    Kraeft, Wolf-Dietrich [Universitat Rostock (Germany)

    2007-07-15

    Strongly coupled plasmas (or non-ideal plasmas) are multi-component charged many-particle systems, in which the mean value of the potential energy of the system is of the same order as or even higher than the mean value of the kinetic energy. The constituents are electrons, ions, atoms and molecules. Dusty (or complex) plasmas contain still mesoscopic (multiply charged) particles. In such systems, the effects of strong coupling (non-ideality) lead to considerable deviations of physical properties from the corresponding properties of ideal plasmas, i.e., of plasmas in which the mean kinetic energy is essentially larger than the mean potential energy. For instance, bound state energies become density dependent and vanish at higher densities (Mott effect) due to the interaction of the pair with the surrounding particles. Non-ideal plasmas are of interest both for general scientific reasons (including, for example, astrophysical questions), and for technical applications such as inertially confined fusion. In spite of great efforts both experimentally and theoretically, satisfactory information on the physical properties of strongly coupled plasmas is not at hand for any temperature and density. For example, the theoretical description of non-ideal plasmas is possible only at low densities/high temperatures and at extremely high densities (high degeneracy). For intermediate degeneracy, however, numerical experiments have to fill the gap. Experiments are difficult in the region of 'warm dense matter'. The monograph tries to present the state of the art concerning both theoretical and experimental attempts. It mainly includes results of the work performed in famous Russian laboratories in recent decades. After outlining basic concepts (chapter 1), the generation of plasmas is considered (chapter 2, chapter 3). Questions of partial (chapter 4) and full ionization (chapter 5) are discussed including Mott transition and Wigner crystallization. Electrical and

  20. Strong correlation in acene sheets from the active-space variational two-electron reduced density matrix method: effects of symmetry and size.

    Science.gov (United States)

    Pelzer, Kenley; Greenman, Loren; Gidofalvi, Gergely; Mazziotti, David A

    2011-06-09

    Polyaromatic hydrocarbons (PAHs) are a class of organic molecules with importance in several branches of science, including medicine, combustion chemistry, and materials science. The delocalized π-orbital systems in PAHs require highly accurate electronic structure methods to capture strong electron correlation. Treating correlation in PAHs has been challenging because (i) traditional wave function methods for strong correlation have not been applicable since they scale exponentially in the number of strongly correlated orbitals, and (ii) alternative methods such as the density-matrix renormalization group and variational two-electron reduced density matrix (2-RDM) methods have not been applied beyond linear acene chains. In this paper we extend the earlier results from active-space variational 2-RDM theory [Gidofalvi, G.; Mazziotti, D. A. J. Chem. Phys. 2008, 129, 134108] to the more general two-dimensional arrangement of rings--acene sheets--to study the relationship between geometry and electron correlation in PAHs. The acene-sheet calculations, if performed with conventional wave function methods, would require wave function expansions with as many as 1.5 × 10(17) configuration state functions. To measure electron correlation, we employ several RDM-based metrics: (i) natural-orbital occupation numbers, (ii) the 1-RDM von Neumann entropy, (iii) the correlation energy per carbon atom, and (iv) the squared Frobenius norm of the cumulant 2-RDM. The results confirm a trend of increasing polyradical character with increasing molecular size previously observed in linear PAHs and reveal a corresponding trend in two-dimensional (arch-shaped) PAHs. Furthermore, in PAHs of similar size they show significant variations in correlation with geometry. PAHs with the strictly linear geometry (chains) exhibit more electron correlation than PAHs with nonlinear geometries (sheets).

  1. Founder populations and the current status of exotic parrots in South ...

    African Journals Online (AJOL)

    Of these, the Rose-ringed Parakeet Psittacula krameri and at least one Agapornis species have become established as breeding wild populations. Like other invasive species they may pose threats to local biodiversity; however, all are strongly associated with major urban centres where significant changes to natural biota ...

  2. Properties and reactions of manganese methylene complexes in the gas phase. The importance of strong metal: carbene bonds for effective olefin metathesis catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, A.E.; Beauchamp, J.L.

    1979-10-10

    In this communication the formation, properties and reactions of the gas phase carbenes MnCH/sub 2//sup +/, (CO)/sub 5/MnCH/sub 2//sup +/, and (CO)/sub 4/MnCH/sub 2//sup +/ are described. Reported results include observation of metathesis and abstraction reactions of the methylene ligand with olefins and the first experimental determination of metal-carbene bond dissociation energies. Important points are that: (a) metal-methylene bond energies are extremely strong; and (b) the Mn/sup +/-methylene bond energy is decreased substantially on addition of five carbonyls to the metal center. If the metal-carbene bond energy exceeds 100 kcal/mol, then transfer of the carbene to an olefin to give a cyclopropane or new olefin will be endothermic and thus will not compete with the metathesis reaction. In order to avoid low turnover numbers resulting from consumption of carbene intermediates, strong metal-carbene bonds are a desirable feature of practical metathesis catalysts. (DP)

  3. Effects of exciton-plasmon strong coupling on third harmonic generation by two-dimensional WS2 at periodic plasmonic interfaces

    Science.gov (United States)

    Sukharev, Maxim; Pachter, Ruth

    2018-03-01

    We study theoretically the optical response of a WS2 monolayer located near periodic metal nanostructured arrays in two and three dimensions. The emphasis of the simulations is on the strong coupling between excitons supported by WS2 and surface plasmon-polaritons supported by various periodic plasmonic interfaces. It is demonstrated that a monolayer of WS2 placed in close proximity of periodic arrays of either slits or holes results in a Rabi splitting of the corresponding surface plasmon-polariton resonance as revealed in calculated transmission and reflection spectra. The nonlinear regime, at which the few-layer WS2 exhibits experimentally third harmonic generation (THG), is studied in detail. Monolayer transition metal dichalcogenides (TMDs) do not exhibit THG because they are non-centrosymmetric, but here we use the monolayer as an approximation to a thin TMD nanostructure. We show that in the strong coupling regime the third harmonic signal is significantly affected by plasmon-polaritons and the symmetry of hybrid exciton-plasmon modes. It is also shown that the local electromagnetic field induced by plasmons is the major contributor to the enhancement of the third harmonic signal in three dimensions. The local electromagnetic fields resulting from the third harmonic generation are greatly localized and highly sensitive to the environment, thus making it a great tool for nano-probes.

  4. Strong population genetic structuring in an annual fish, Nothobranchius furzeri, suggests multiple savannah refugia in southern Mozambique

    Czech Academy of Sciences Publication Activity Database

    Bartáková, Veronika; Reichard, Martin; Janko, Karel; Polačik, Matej; Blažek, Radim; Reichwald, K.; Cellerino, A.; Bryja, Josef

    2013-01-01

    Roč. 13, č. 196 (2013), s. 196 ISSN 1471-2148 R&D Projects: GA ČR GA206/09/0815; GA ČR GBP505/12/G112 Institutional support: RVO:68081766 Keywords : Temporary pool * Phylogeography * Population genetics * Cyprinodontiformes * Senescence * Pluvials * Pleistocene climate changes * Dispersal * Founder effect * Killifish Subject RIV: EG - Zoology Impact factor: 3.407, year: 2013 http://www.biomedcentral.com/1471-2148/13/196

  5. An Efficient and Robust Hybrid Damper for LCL- or LLCL-Based Grid-Tied Inverter With Strong Grid-Side Harmonic Voltage Effect Rejection

    DEFF Research Database (Denmark)

    Liu, Yuan; Wu, Weimin; He, Yuanbin

    2016-01-01

    A high-order (LCL or LLCL) power filter with a small grid-side inductor is becoming more preferred for a grid-tied inverter due to less total inductance and reduced costs. In a microgrid, the background harmonic voltage (BHV) may distort the injected currents of the grid-tied inverters. In order......-current-feedback AD. Based on this, a single-loop current control with a hybrid damper is proposed for a single-phase LCLor LLCL-filter-based grid-tied inverter. A step-by-step design of the controller method is also introduced in detail. Experiments on a 2-kW prototype fully demonstrate the strong robustness...

  6. LINE SHAPES OF DOPPLER-FREE RESONANCE IN SRFM: STRONG ATOM-WALL INTERACTION AND PRESSURE EFFECT ON THE FREQUENCY SHIFT OF AN ALKALI VAPOR

    Directory of Open Access Journals (Sweden)

    B BOUHAFS

    2003-12-01

    Full Text Available The attractive potential energy between the atoms of rubidium vapor and a dielectric wall has been investigated by monitoring the reflection light at the interface. The atom- wall interaction potential of the form V(z = - C /z3 (z: atom-wall allows to predict experimental results only for weak regime, i.e., where C<< 0.2 kHzmm3. In the strong interaction case, the dispersive line shape is turned into an absorption-type line shape. The influence of atomic density on the shift of  the selective reflection resonance  relatively to the frequency of unperturbed atomic transition is found to be red with a negative slope. This technique opens the way to characterize the windows made of different materials thin films.

  7. Influence of d-level degeneration and Jahn-Teller effect on electronic structure of manganites by means of strong coupling approach

    CERN Document Server

    Dunaevskij, S M

    2001-01-01

    The calculation of the E(k) dispersion curves of the charge carriers in the LaMnO sub 3 -type perovskites for the basic types of the Mn sublattice squinted antiferromagnetic ordering is carried out within the frames of the strong coupling method. The calculation of the E(k) spectrum of the antiferromagnetic structures is accomplished for the first time with an account of the manganese e sub g -level degeneration and the Jahn-Teller distortion of the perovskite cubic structure, which required diagonalization of the eight order Hamiltonian matrices. The analytical expressions for the E(k) functions in the separate points and on the individual lines of the corresponding Brillouin zone are obtained. The accomplished calculations showed, that there can be no electron-hole symmetry of properties in the La sub 1 sub - sub x Ca sub x MnO sub 3 system

  8. Jean-Alfred Fournier - the founder of the European venereology and dermatology (on the one hundredth death anniversary

    Directory of Open Access Journals (Sweden)

    O. A. Kisteneva

    2014-01-01

    Full Text Available The article presents a life story of a great French dermatologist and venereologist, one of the founders of the theory of syphilis Jean-Alfred Fournier (1832-1914. It provides data on the published works by Jean-Alfred Fournier, some of which earned him a doctoral degree. It also provides data on Fournier’s election as a member of the French Academy of Medicine in 1879 as well as on the founding of the French Society of Dermatology and Syphiligraphy by Fournier and other French dermatologists in 1889. The article defines the contribution made by Fournier to the development of venereology and practical medicine in the second half of the 19th century and early 20th century.

  9. [Max Isserlin, Kantian orientation at Königsberg, psychotherapist with Kraepelin, founder of child psychiatry at Munich, emigrant to Britain].

    Science.gov (United States)

    Peters, U H

    2002-01-01

    This account of the life and work of Max Isserlin (1879 - 1941) wants to be a reminder of a German-Jewish fate next to Kraepelin and as a forced emigrant. Immediately after his studies at Königsberg Isserlin in 1903 came to Kraepelin at Heidelberg, later he followed him to Munich. All his life he kept a Kantian orientation and defended Kraepelin's positions out of this background. Kraepelin entrusted to him all of psychotherapy, theory and practice, which Isserlin for at least 18 years gave courses of in Kraepelin's department. His textbook of psychotherapy thus transmissions Kraepelins convictions about this topic also. During World War I Isserlin was the head of a field-hospital for brain damaged soldiers and continued working this way after the end of the war. Finally he became the founder of child psychiatry in Munich, until he was forced to leave Germany for Britain with a heavy heart.

  10. High resolution IR diode laser study of collisional energy transfer between highly vibrationally excited monofluorobenzene and CO2: the effect of donor fluorination on strong collision energy transfer.

    Science.gov (United States)

    Kim, Kilyoung; Johnson, Alan M; Powell, Amber L; Mitchell, Deborah G; Sevy, Eric T

    2014-12-21

    Collisional energy transfer between vibrational ground state CO2 and highly vibrationally excited monofluorobenzene (MFB) was studied using narrow bandwidth (0.0003 cm(-1)) IR diode laser absorption spectroscopy. Highly vibrationally excited MFB with E' = ∼41,000 cm(-1) was prepared by 248 nm UV excitation followed by rapid radiationless internal conversion to the electronic ground state (S1→S0*). The amount of vibrational energy transferred from hot MFB into rotations and translations of CO2 via collisions was measured by probing the scattered CO2 using the IR diode laser. The absolute state specific energy transfer rate constants and scattering probabilities for single collisions between hot MFB and CO2 were measured and used to determine the energy transfer probability distribution function, P(E,E'), in the large ΔE region. P(E,E') was then fit to a bi-exponential function and extrapolated to the low ΔE region. P(E,E') and the biexponential fit data were used to determine the partitioning between weak and strong collisions as well as investigate molecular properties responsible for large collisional energy transfer events. Fermi's Golden rule was used to model the shape of P(E,E') and identify which donor vibrational motions are primarily responsible for energy transfer. In general, the results suggest that low-frequency MFB vibrational modes are primarily responsible for strong collisions, and govern the shape and magnitude of P(E,E'). Where deviations from this general trend occur, vibrational modes with large negative anharmonicity constants are more efficient energy gateways than modes with similar frequency, while vibrational modes with large positive anharmonicity constants are less efficient at energy transfer than modes of similar frequency.

  11. Constraining Nonperturbative Strong-Field Effects in Scalar-Tensor Gravity by Combining Pulsar Timing and Laser-Interferometer Gravitational-Wave Detectors

    Directory of Open Access Journals (Sweden)

    Lijing Shao

    2017-10-01

    Full Text Available Pulsar timing and laser-interferometer gravitational-wave (GW detectors are superb laboratories to study gravity theories in the strong-field regime. Here, we combine these tools to test the mono-scalar-tensor theory of Damour and Esposito-Farèse (DEF, which predicts nonperturbative scalarization phenomena for neutron stars (NSs. First, applying Markov-chain Monte Carlo techniques, we use the absence of dipolar radiation in the pulsar-timing observations of five binary systems composed of a NS and a white dwarf, and eleven equations of state (EOSs for NSs, to derive the most stringent constraints on the two free parameters of the DEF scalar-tensor theory. Since the binary-pulsar bounds depend on the NS mass and the EOS, we find that current pulsar-timing observations leave scalarization windows, i.e., regions of parameter space where scalarization can still be prominent. Then, we investigate if these scalarization windows could be closed and if pulsar-timing constraints could be improved by laser-interferometer GW detectors, when spontaneous (or dynamical scalarization sets in during the early (or late stages of a binary NS (BNS evolution. For the early inspiral of a BNS carrying constant scalar charge, we employ a Fisher-matrix analysis to show that Advanced LIGO can improve pulsar-timing constraints for some EOSs, and next-generation detectors, such as the Cosmic Explorer and Einstein Telescope, will be able to improve those bounds for all eleven EOSs. Using the late inspiral of a BNS, we estimate that for some of the EOSs under consideration, the onset of dynamical scalarization can happen early enough to improve the constraints on the DEF parameters obtained by combining the five binary pulsars. Thus, in the near future, the complementarity of pulsar timing and direct observations of GWs on the ground will be extremely valuable in probing gravity theories in the strong-field regime.

  12. Genetic evidence of multiple invasions and a small number of founders of Asian Palmyra palm (Borassus flabellifer) in Thailand.

    Science.gov (United States)

    Pipatchartlearnwong, Kwanjai; Swatdipong, Akarapong; Vuttipongchaikij, Supachai; Apisitwanich, Somsak

    2017-10-12

    Borassus flabellifer or Asian Palmyra palm is an important crop for local economies in the South and Southeast Asia for its fruit and palm sugar production. Archeological and historical evidence indicated the presence of this species in Southeast Asia dating back at least 1500 years. B. flabellifer is believed to be originated in Africa, spread to South Asia and introduced into Southeast Asia through commercial routes and dissemination of cultures, however, the nature of its invasion and settlement in Thailand is unclear. Here, we analyzed genetic data of 230 B. flabellifer accessions across Thailand using 17 EST-SSR and 12 gSSR polymorphic markers. Clustering analysis revealed that the population consisted of two genetic clusters (STRUCTURE K = 2). Cluster I is found mainly in southern Thailand, while Cluster II is found mainly in the northeastern. Those found in the central are of an extensive mix between the two. These two clusters are in moderate differentiation (F ST  = 0.066 and N M  = 3.532) and have low genetic diversity (H O  = 0.371 and 0.416; A R  = 2.99 and 3.19, for the cluster I and II respectively). The minimum numbers of founders for each genetic group varies from 3 to 4 individuals, based on simulation using different allele frequency assumptions. These numbers coincide with that B. flabellifer is dioecious, and a number of seeds had to be simultaneously introduced for obtaining both male and female founders. From these data and geographical and historical evidence, we hypothesize that there were at least two different invasive events of B. flabellifer in Thailand. B. flabellifer was likely brought through the Straits of Malacca to be propagated in the southern Thailand as one of the invasive events before spreading to the central Thailand. The second event likely occurred in Khmer Empire, currently Cambodia, before spreading to the northeastern Thailand.

  13. A founder BRCA2 mutation in non-Afrikaner breast cancer patients of the Western Cape of South Africa.

    Science.gov (United States)

    van der Merwe, N C; Hamel, N; Schneider, S-R; Apffelstaedt, J P; Wijnen, J T; Foulkes, W D

    2012-02-01

    Founder mutations in BRCA1 and BRCA2 have been reported in many different populations. We studied 105 Coloured and 16 Black Xhosa women residing in the Western Cape of South Africa diagnosed with breast cancer. We screened these patients using our standard panel of six previously reported SA Afrikaner and Ashkenazi Jewish BRCA1/2 mutations and identified only two Afrikaner mutations. Further screening by the protein truncation test (BRCA1 exon 11, and BRCA2 exons 10 and 11) revealed an additional four deleterious mutations (BRCA1 c.1504_ 1508del,p.Leu502AlafsX2, BRCA2 c.2826_2829del,p.Ile943LysfsX16, c.6447_6448dup,p.Lys2150IlefsX19 and c.5771_5774del,p.Ile1924Argfs X38). The latter, also known in Breast Cancer Information Core nomenclature as 5999del4, was identified in 4 of 105 (3.8%) Coloureds and 4 of 16 (25%) Xhosa women, which makes it a frequent founder mutation in the Western Cape Province. Although this mutation was previously reported to occur in the Netherlands, haplotype analysis indicated two distinct origins for the Dutch and South African mutations, excluding the possibility of a common Dutch ancestor and suggesting gene flow from the indigenous tribes such as the Xhosa to the Coloured population instead. Further studies to determine the carrier rate of this variant in the Xhosa and other SA populations are warranted. © 2011 John Wiley & Sons A/S.

  14. HealthSouth's most wanted. Founder and former chairman and CEO Richard Scrushy is indicted for 85 counts of conspiracy, fraud and money laundering.

    Science.gov (United States)

    Piotrowski, Julie

    2003-11-10

    Wake-up call for the industry or an isolated case of corporate chicanery? Healthcare experts are divided on the import of Richard Scrushy's indictment on 85 counts last week in connection with the financial scandal at HealthSouth Corp. The indictment alleges the company founder relied on electronic and telephone surveillance, threats and intimidation to control his accomplices.

  15. Quantum electrodynamics of strong fields

    International Nuclear Information System (INIS)

    Greiner, W.

    1983-01-01

    Quantum Electrodynamics of Strong Fields provides a broad survey of the theoretical and experimental work accomplished, presenting papers by a group of international researchers who have made significant contributions to this developing area. Exploring the quantum theory of strong fields, the volume focuses on the phase transition to a charged vacuum in strong electric fields. The contributors also discuss such related topics as QED at short distances, precision tests of QED, nonperturbative QCD and confinement, pion condensation, and strong gravitational fields In addition, the volume features a historical paper on the roots of quantum field theory in the history of quantum physics by noted researcher Friedrich Hund

  16. Double salt ionic liquids based on 1-ethyl-3-methylimidazolium acetate and hydroxyl-functionalized ammonium acetates: strong effects of weak interactions.

    Science.gov (United States)

    Pereira, Jorge F B; Barber, Patrick S; Kelley, Steven P; Berton, Paula; Rogers, Robin D

    2017-10-11

    The properties of double salt ionic liquids based on solutions of cholinium acetate ([Ch][OAc]), ethanolammonium acetate ([NH 3 (CH 2 ) 2 OH][OAc]), hydroxylammonium acetate ([NH 3 OH][OAc]), ethylammonium acetate ([NH 3 CH 2 CH 3 ][OAc]), and tetramethylammonium acetate ([N(CH 3 ) 4 ][OAc]) in 1-ethyl-3-methylimidazolium acetate ([C 2 mim][OAc]) were investigated by NMR spectroscopy and X-ray crystallography. Through mixture preparation, the solubility of [N(CH 3 ) 4 ][OAc] is the lowest, and [Ch][OAc] shows a 3-fold lower solubility than the other hydroxylated ammonium acetate-based salts in [C 2 mim][OAc] at room temperature. NMR and X-ray crystallographic studies of the pure salts suggest that the molecular-level mechanisms governing such miscibility differences are related to the weaker interactions between the -NH 3 groups and [OAc] - , even though three of these salts possess the same strong 1 : 1 hydrogen bonds between the cation -OH group and the [OAc] - ion. The formation of polyionic clusters between the anion and those cations with unsatisfied hydrogen bond donors seems to be a new tool by which the solubility of these salts in [C 2 mim][OAc] can be controlled.

  17. Fermi resonance and strong anharmonic effects in the absorption spectra of the ν-OH ( ν-OD) vibration of solid H- and D-benzoic acid

    Science.gov (United States)

    Yaremko, A. M.; Ratajczak, H.; Barnes, A. J.; Baran, J.; Durlak, P.; Latajka, Z.

    2009-10-01

    The vibrational spectra of polycrystalline benzoic acid (BA) and its deuterated derivative were studied over the wide frequency region 4000-10 cm -1 by IR and Raman methods. A theoretical analysis of the hydrogen bond frequency region and calculations at the B3LYP/6-311++G(2d, 2p) level for the benzoic acid cyclic dimer in the gas phase were made. In order to study the dynamics of proton transfer two formalisms were applied: Car-Parrinello Molecular Dynamics (CPMD) and Path Integrals Molecular Dynamics (PIMD). It was shown that the experimentally observed very broad ν-OH band absorption is the result of complex anharmonic interaction: Fermi resonance between the OH-stretching and bending vibrations and strong interaction of the ν-OH stretching with the low frequency phonons. The theoretical analysis in the framework of such an approach gave a good correlation with experiment. From the CPMD calculations it was confirmed that the O-H⋯O bridge is not rigid, with the O⋯O distance being described by a large amplitude motion. For the benzoic acid dimer we observed stepwise (asynchronous) proton transfer.

  18. Effect of delayed link failure on probability of loss of assured safety in temperature-dependent systems with multiple weak and strong links.

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, J. D. (ProStat, Mesa, AZ); Oberkampf, William Louis; Helton, Jon Craig (Arizona State University, Tempe, AZ)

    2007-05-01

    Weak link (WL)/strong link (SL) systems constitute important parts of the overall operational design of high consequence systems, with the SL system designed to permit operation of the system only under intended conditions and the WL system designed to prevent the unintended operation of the system under accident conditions. Degradation of the system under accident conditions into a state in which the WLs have not deactivated the system and the SLs have failed in the sense that they are in a configuration that could permit operation of the system is referred to as loss of assured safety. The probability of such degradation conditional on a specific set of accident conditions is referred to as probability of loss of assured safety (PLOAS). Previous work has developed computational procedures for the calculation of PLOAS under fire conditions for a system involving multiple WLs and SLs and with the assumption that a link fails instantly when it reaches its failure temperature. Extensions of these procedures are obtained for systems in which there is a temperature-dependent delay between the time at which a link reaches its failure temperature and the time at which that link actually fails.

  19. Calculation of the total plasma concentration of nonvolatile weak acids and the effective dissociation constant of nonvolatile buffers in plasma for use in the strong ion approach to acid-base balance in cats.

    Science.gov (United States)

    McCullough, Sheila M; Constable, Peter D

    2003-08-01

    To determine values for the total concentration of nonvolatile weak acids (Atot) and effective dissociation constant of nonvolatile weak acids (Ka) in plasma of cats. Convenience plasma samples of 5 male and 5 female healthy adult cats. Cats were sedated, and 20 mL of blood was obtained from the jugular vein. Plasma was tonometered at 37 degrees C to systematically vary PCO2 from 8 to 156 mm Hg, thereby altering plasma pH from 6.90 to 7.97. Plasma pH, PCO2, and concentrations of quantitatively important strong cations (Na+, K+, and Ca2+), strong anions (Cl-, lactate), and buffer ions (total protein, albumin, and phosphate) were determined. Strong ion difference was estimated from the measured strong ion concentrations and nonlinear regression used to calculate Atot and Ka from the measured pH and PCO2 and estimated strong ion difference. Mean (+/- SD) values were as follows: Atot = 24.3 +/- 4.6 mmol/L (equivalent to 0.35 mmol/g of protein or 0.76 mmol/g of albumin); Ka = 0.67 +/- 0.40 x 10(-7); and the negative logarithm (base 10) of Ka (pKa) = 7.17. At 37 degrees C, pH of 7.35, and a partial pressure of CO2 (PCO2) of 30 mm Hg, the calculated venous strong ion difference was 30 mEq/L. These results indicate that at a plasma pH of 7.35, a 1 mEq/L decrease in strong ion difference will decrease pH by 0.020, a 1 mm Hg decrease in PCO2 will increase plasma pH by 0.011, and a 1 g/dL decrease in albumin concentration will increase plasma pH by 0.093.

  20. Donor T cells primed on leukemia lysate-pulsed recipient APCs mediate strong graft-versus-leukemia effects across MHC barriers in full chimeras

    OpenAIRE

    Ghosh, Arnab; Koestner, Wolfgang; Hapke, Martin; Schlaphoff, Verena; Länger, Florian; Baumann, Rolf; Koenecke, Christian; Cornberg, Markus; Welte, Karl; Blazar, Bruce R.; Sauer, Martin G.

    2009-01-01

    Antigen-presenting cells (APCs) of host origin drive graft-versus-leukemia (GVL) effects but can also trigger life-threatening graft-versus-host disease (GVHD) after hematopoietic cell transplantation (HCT) across major histocompatibility complex (MHC) barriers. We show that in vitro priming of donor lymphocytes can circumvent the need of recipient-derived APCs in vivo for mediating robust GVL effects and significantly diminishes the risk of severe GVHD. In vitro, generated and expanded T cel...